WorldWideScience

Sample records for counter electrode materials

  1. Lanthanide doped ceria thin films as possible counter electrode materials in electrochromic devices

    CERN Document Server

    Hartridge, A

    2000-01-01

    suitability of these thin films as counter electrodes in electrochromic devices. The final chapter then turns to the electrochemical insertion of lithium into these materials using cyclic voltammetry. All films studied enabled the reversible insertion of lithium with varying potentials and charge capacities without the loss of transmission of light common to other potential counter electrode materials. Certain compositions however, comprising ceria doped with Dy, Y, Nd and Pr, allowed enough lithium insertion (charge capacity) to fulfil the requirements of counter electrode materials in electrochromic devices. These materials are therefore worthy of further study. Crystalline solid solutions of lanthanide doped ceria have long been known for their high ionic conductivity and as such have found applications as oxygen sensors and in solid oxide fuel cells. With advances in preparative techniques over the years, thin films of ceria doped with zirconia and titania have been studied and found to possess the necess...

  2. Lanthanide doped ceria thin films as possible counter electrode materials in electrochromic devices

    Energy Technology Data Exchange (ETDEWEB)

    Hartridge, A

    2000-09-01

    Crystalline solid solutions of lanthanide doped ceria have long been known for their high ionic conductivity and as such have found applications as oxygen sensors and in solid oxide fuel cells. With advances in preparative techniques over the years, thin films of ceria doped with zirconia and titania have been studied and found to possess the necessary criteria to meet the requirements of counter electrode materials in solid state electrochromic devices. Existing preparative techniques however, have failed to produce thin films of lanthanide doped ceria for study of their optical and electrochemical properties. This thesis therefore presents in the first chapter, existing knowledge of these materials, a novel preparation technique developed as part of the thesis to prepare these materials as crystalline aqueous dispersions suitable for the preparation of quality thin films and the subsequent characterisation of sols and gels of these materials compared to the same materials prepared by conventional techniques. High-resolution transmission electron microscopy has also been used to assess the homogeneity of these nanocrystals on a nanoscale for the first time. The second chapter then discusses the optical properties of solids and thin films in general before using the crystalline sols produced in chapter 1 to fabricate thin films of these materials for the first time. The optical properties of these materials is then discussed in detail and the results show the optical suitability of these thin films as counter electrodes in electrochromic devices. The final chapter then turns to the electrochemical insertion of lithium into these materials using cyclic voltammetry. All films studied enabled the reversible insertion of lithium with varying potentials and charge capacities without the loss of transmission of light common to other potential counter electrode materials. Certain compositions however, comprising ceria doped with Dy, Y, Nd and Pr, allowed enough lithium

  3. Penternary chalcogenides nanocrystals as catalytic materials for efficient counter electrodes in dye-synthesized solar cells

    Science.gov (United States)

    Özel, Faruk; Sarılmaz, Adem; Istanbullu, Bilal; Aljabour, Abdalaziz; Kuş, Mahmut; Sönmezoğlu, Savaş

    2016-07-01

    The penternary chalcogenides Cu2CoSn(SeS)4 and Cu2ZnSn(SeS)4 were successfully synthesized by hot-injection method, and employed as a catalytic materials for efficient counter electrodes in dye-synthesized solar cells (DSSCs). The structural, compositional, morphological and optical properties of these pentenary semiconductors were characterized by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), energy-dispersive spectrometer (EDS) and ultraviolet-visible (UV-Vis) spectroscopy. The Cu2CoSn(SeS)4 and Cu2ZnSn(SeS)4 nanocrystals had a single crystalline, kesterite phase, adequate stoichiometric ratio, 18-25 nm particle sizes which are forming nanospheres, and band gap energy of 1.18 and 1.45 eV, respectively. Furthermore, the electrochemical impedance spectroscopy and cyclic voltammograms indicated that Cu2CoSn(SeS)4 nanocrystals as counter electrodes exhibited better electrocatalytic activity for the reduction of iodine/iodide electrolyte than that of Cu2ZnSn(SeS)4 nanocrystals and conventional platinum (Pt). The photovoltaic results demonstrated that DSSC with a Cu2CoSn(SeS)4 nanocrystals-based counter electrode achieved the best efficiency of 6.47%, which is higher than the same photoanode employing a Cu2ZnSn(SeS)4 nanocrystals (3.18%) and Pt (5.41%) counter electrodes. These promising results highlight the potential application of penternary chalcogen Cu2CoSn(SeS)4 nanocrystals in low-cost, high-efficiency, Pt-free DSSCs.

  4. A Graphene Composite Material with Single Cobalt Active Sites: A Highly Efficient Counter Electrode for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Cui, Xiaoju; Xiao, Jianping; Wu, Yihui; Du, Peipei; Si, Rui; Yang, Huaixin; Tian, Huanfang; Li, Jianqi; Zhang, Wen-Hua; Deng, Dehui; Bao, Xinhe

    2016-06-01

    The design of catalysts that are both highly active and stable is always challenging. Herein, we report that the incorporation of single metal active sites attached to the nitrogen atoms in the basal plane of graphene leads to composite materials with superior activity and stability when used as counter electrodes in dye-sensitized solar cells (DSSCs). A series of composite materials based on different metals (Mn, Fe, Co, Ni, and Cu) were synthesized and characterized. Electrochemical measurements revealed that CoN4 /GN is a highly active and stable counter electrode for the interconversion of the redox couple I(-) /I3 (-) . DFT calculations revealed that the superior properties of CoN4 /GN are due to the appropriate adsorption energy of iodine on the confined Co sites, leading to a good balance between adsorption and desorption processes. Its superior electrochemical performance was further confirmed by fabricating DSSCs with CoN4  /GN electrodes, which displayed a better power conversion efficiency than the Pt counterpart.

  5. Carbon Nanotube-based Nanohybrid Materials as Counter Electrode for Highly Efficient Dye-sensitized Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji-Soo; Sim, Eun-Ju; Dao, Van-Duong; Choi, Ho-Suk [Chungnam National University, Daejeon (Korea, Republic of)

    2016-04-15

    In this study, we present an excellent approach for easily and uniformly immobilizing Pt, Au and bimetallic PtAu nanoparticles (NPs) on a multi-walled carbon nanotube (MWNT)-coated layer through dry plasma reduction. The NPs are stably and uniformly immobilized on the surface of MWNTs and the nanohybrid materials are applied to counter electrode (CE) of dye-sensitized solar cells (DSCs). The electrochemical properties of CEs are examined through cyclic voltammogram, electrochemical impedance spectroscopy, and Tafel measurements. As a result, both electrochemical catalytic activity and electrical conductivity are highest for PtAu/MWNT electrode. The DSC employing PtAu/MWNT CE exhibits power conversion efficiency of 7.9%. The efficiency is better than those of devices with MWNT (2.6%), AuNP/MWNT (2.7%) and PtNP/MWNT (7.5%) CEs.

  6. Synthesis and characterization of natural dye and counter electrode thin films with different carbon materials for dye-sensitized solar cells.

    Science.gov (United States)

    Chang, Ho; Chen, Tien-Li; Kao, Mu-Jung; Chen, Chih-Hao; Chien, Shu-Hua; Jiang, Lii-Jenq

    2011-08-01

    This study aims to deal with the film of the counter electrode of dye-sensitized solar cells (DSSCs) and the preparation, structure and characteristics of the extract of natural dye. This study adopts different commercial carbon materials such as black lead, carbon black and self-made TiO2-MWCNT compound nanoparticle as the film of the counter electrodes. Moreover, for the preparation of natural dyes, anthocyanins and chlorophyll dyes are extracted from mulberry and pomegranate respectively. Furthermore, the extracted anthocyanins and chlorophyll are blended into cocktail dye to complete the preparation of natural dye. Results show that the photoelectric conversion efficiency of the single-layer TiO2-MWCNT counter electrode film and the cocktail dye of the DSSCs is 0.462%.

  7. Carbonaceous materials and their advances as a counter electrode in dye-sensitized solar cells: challenges and prospects.

    Science.gov (United States)

    Kouhnavard, Mojgan; Ludin, Norasikin Ahmad; Ghaffari, Babak V; Sopian, Kamarozzaman; Ikeda, Shoichiro

    2015-05-11

    Dye-sensitized solar cells (DSSCs) serve as low-costing alternatives to silicon solar cells because of their low material and fabrication costs. Usually, they utilize Pt as the counter electrode (CE) to catalyze the iodine redox couple and to complete the electric circuit. Given that Pt is a rare and expensive metal, various carbon materials have been intensively investigated because of their low costs, high surface areas, excellent electrochemical stabilities, reasonable electrochemical activities, and high corrosion resistances. In this feature article, we provide an overview of recent studies on the electrochemical properties and photovoltaic performances of carbon-based CEs (e.g., activated carbon, nanosized carbon, carbon black, graphene, graphite, carbon nanotubes, and composite carbon). We focus on scientific challenges associated with each material and highlight recent advances achieved in overcoming these obstacles. Finally, we discuss possible future directions for this field of research aimed at obtaining highly efficient DSSCs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. FeS/nickel foam as stable and efficient counter electrode material for quantum dot sensitized solar cells

    Science.gov (United States)

    Geng, Huifang; Zhu, Liqun; Li, Weiping; Liu, Huicong; Quan, Linlin; Xi, Fanxing; Su, Xunwen

    2015-05-01

    A stable and efficient FeS/nickel foam (NF) counter electrode for quantum dots-sensitized solar cells (QDSCs) is first fabricated by electrochemistry deposition and characterized with scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), current voltage and impedance spectroscopy. The QDSC based on FeS/NF CE achieves a power conversion efficiency (PCE) of 4.39% attributing to the high fill factor (FF) of 0.58, and the PCE is much higher than that of based on FeS/FTO CE (2.76%) and other reported FeS CEs (1.76% and 3.34%). The phenomenon that the electrode can transform between FeS/NF (in the polysulfide electrolyte) and Fe2O3/NF (in the air) spontaneously is first reported. And the excellent stability in photoelectric performance of the CE is also demonstrated in the present work. Therefore, the FeS/NF is very promising as a stable and efficient CE for QDSCs.

  9. Mesoporous Bi₂S₃ nanorods with graphene-assistance as low-cost counter-electrode materials in dye-sensitized solar cells.

    Science.gov (United States)

    Guo, Sheng-qi; Jing, Tian-zeng; Zhang, Xiao; Yang, Xiao-bing; Yuan, Zhi-hao; Hu, Fang-zhong

    2014-11-06

    In this work, we report the synthesis of mesoporous Bi₂S₃ nanorods under hydrothermal conditions without additives, and investigated their catalytic activities as the CE in DSCs by I-V curves and tested conversion efficiency. To further improve their power conversion efficiency, we added different amounts of reduced graphene by simple physical mixing. With the addition of 9 wt% reduced graphene (rGO), the short-circuit current density, open-circuit voltage and fill factor were Jsc = 15.33 mA cm(-2), Voc = 0.74 V and FF = 0.609. More importantly, the conversion efficiency reached 6.91%, which is slightly inferior to the commercial Pt counter electrode (7.44%). Compared to the conventional Pt counter electrodes of solar cells, this new material has the advantages of low-cost, facile synthesis and high efficiency with graphene assistance. To the best of our knowledge, this Bi₂S₃ + 9 wt% rGO system has the best performance ever recorded in all Bi₂S₃-based CEs in the DSCs system.

  10. Graphene-NiO nanohybrid prepared by dry plasma reduction as a low-cost counter electrode material for dye-sensitized solar cells.

    Science.gov (United States)

    Dao, Van-Duong; Larina, Liudmila L; Jung, Kwang-Deog; Lee, Joong-Kee; Choi, Ho-Suk

    2014-01-07

    NiO nanoparticles (NPs) were hybridized on the surface of reduced graphene oxide (RGO) by dry plasma reduction (DPR) at atmospheric pressure without any toxic chemicals and at a low temperature. NiO-NPs of 0.5-3 nm size, with a typical size of 1.5 nm, were uniformly hybridized on the surface of RGO. An XPS analysis and the Raman spectra also revealed the repair of some structural damage on the basal plane of the graphene. The material when applied to the counter electrode (CE) of dye-sensitized solar cells (DSCs) exhibited a power conversion efficiency of 7.42% (± 0.10%), which is comparable to a conventional Pt-sputtered CE (8.18% (± 0.08%)). This material outperformed CEs produced using NiO-NPs (1.53% (± 0.15%)), GO (4.48% (± 0.12%)) and RGO (5.18% (± 0.11)) due to its high electrochemical catalytic activity and high conductivity. The charge transfer resistance for NiO-NP-RGO was as low as 1.93 Ω cm(2), while those of a NiO-NP-immobilized electrode and a GO-coated electrode were 44.39 Ω cm(2) and 12.19 Ω cm(2), respectively, due to a synergistic effect.

  11. Low-temperature self-assembled vertically aligned carbon nanofibers as counter-electrode material for dye-sensitized solar cells

    Science.gov (United States)

    Mahpeykar, S. M.; Tabatabaei, M. K.; Ghafoori-fard, H.; Habibiyan, H.; Koohsorkhi, J.

    2013-11-01

    Low-temperature AC-DC PECVD is employed for direct growth of vertically aligned carbon nanofibers (VACNFs) on ordinary transparent conductive glass as counter-electrode material for dye-sensitized solar cells (DSSCs). To the best of our knowledge, this is the first report on utilization of VACNFs grown directly on ordinary FTO-coated glass as a cost-effective catalyst material in DSSCs. According to the FESEM images, the as-grown arrays are well aligned and dense, and offer uniform coverage on the surface of the substrate. In-plane and out-of-plane conductivity measurements reveal their good electrical conductivity, and Raman spectroscopy suggests a high number of electrocatalytic active sites, favoring charge transport at the electrolyte/electrode interface. Hybrid VACNF/Pt electrodes are also fabricated for performance comparison with Pt and VACNF electrodes. X-ray diffraction results verify the crystallization of Pt in hybrid electrodes and further confirm the vertical alignment of carbon nanofibers. Electrochemical characterization indicates that VACNFs provide both high catalytic and good charge transfer capability, which can be attributed to their high surface area, defect-rich and one-dimensional structure, vertical alignment and low contact resistance. As a result, VACNF cells can achieve a comparable performance (˜5.6%) to that of the reference Pt cells (˜6.5%). Moreover, by combination of the excellent charge transport and catalytic ability of VACNFs and the high conductivity of Pt nanoparticles, hybrid VACNF/Pt cells can deliver a performance superior to that of the Pt cells (˜7.2%), despite having a much smaller amount of Pt loading, which raises hopes for low-cost large-scale production of DSSCs in the future.

  12. Electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Amine, Khalil; Abouimrane, Ali; Belharouak, Ilias

    2017-01-31

    A process for forming a surface-treatment layer on an electroactive material includes heating the electroactive material and exposing the electroactive material to a reducing gas to form a surface-treatment layer on the electroactive material, where the surface-treatment layer is a layer of partial reduction of the electroactive material.

  13. Effect of Counter Electrode in Electroformation of Giant Vesicles

    Directory of Open Access Journals (Sweden)

    Shuuhei Oana

    2011-11-01

    Full Text Available Electroformation of cell-sized lipid membrane vesicles (giant vesicles, GVs, from egg yolk phosphatidylcholine, was examined varying the shape of the counter electrode. Instead of a planar ITO (indium tin oxide electrode commonly used, platinum wire mesh was employed as a counter electrode facing lipid deposit on a planar formation electrode. The modification did not significantly alter GV formation, and many GVs of 30–50 µm, some as large as 100 µm, formed as with the standard setup, indicating that a counter electrode does not have to be a complete plane. When the counter electrode was reduced to a set of two parallel platinum wires, GV formation deteriorated. Some GVs formed, but only in close proximity to the counter electrode. Lower electric voltage with this setup no longer yielded GVs. Instead, a large onion-like multilamellar structure was observed. The deteriorated GV formation and the formation of a multilamellar structure seemed to indicate the weakened effect of the electric field on lipid deposit due to insufficient coverage with a small counter electrode. Irregular membranous objects formed by spontaneous swelling of lipid without electric voltage gradually turned into multilamellar structure upon following application of voltage. No particular enhancement of GV formation was observed when lipid deposit on a wire formation electrode was used in combination with a large planar counter electrode.

  14. FUEL CELL ELECTRODE MATERIALS

    Science.gov (United States)

    FUEL CELL ELECTRODE MATERIALS. RAW MATERIAL SELECTION INFLUENCES POLARIZATION BUT IS NOT A SINGLE CONTROLLING FACTOR. AVAILABLE...DATA INDICATES THAT AN INTERRELATIONSHIP OF POROSITY, AVERAGE PORE VOLUME, AND PERMEABILITY CONTRIBUTES TO ELECTRODE FUEL CELL BEHAVIOR.

  15. A freeze-dried graphene counter electrode enhances the performance of dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Kai-Hsiang; Wang, Hong-Wen, E-mail: hongwen@cycu.edu.tw

    2014-01-01

    A flexible graphene/polyimide (PI) counter electrode without a fluorine-doped tin oxide (FTO) layer has been fabricated for dye-sensitized solar cell (DSSCs) applications. The flexible counter electrode consists of polyimide double-sided tape as a substrate beneath a graphene film acting as the conductive and catalytic layer. Chemically reduced graphene oxide (rGO) on the PI electrode (rGO-PI) shows comparable catalytic activity to that of the reference sputtered platinum/FTO counter electrodes (Sputter-Pt/FTO). A DSSC with a freeze-dried rGO-PI (FD-rGO-PI) counter electrode shows an overall conversion efficiency (η) of 5.45%, while that of the conventional Sputter-Pt/FTO electrode is 5.52%. The DSSC with a thermally dried rGO-PI (Gel-rGO-PI) counter electrode (not freeze-dried) exhibits a smooth morphology and much poorer performance (η = 1.61%). Field emission scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry measurements demonstrate that the FD-rGO-PI electrode possesses a porous structure, numerous edges, minimum charge-transfer resistance and a higher electrocatalytic activity toward the I{sub 3}{sup −}/I{sup −} redox couple than that of the Gel-rGO-PI electrode. The high electrocatalytic activity, facile preparation procedure, absence of FTO, and material flexibility render the FD-rGO-PI electrode an ideal alternative to conventional DSSC counter electrodes. - Highlights: • Highly rough and conductive graphene-based counter electrode is synthesized. • The characteristics of graphene surface by freeze drying are different. • The graphene counter electrode exhibits comparable performance to that of sputtered Pt one.

  16. W-doped TiO2 mesoporous electron transport layer for efficient hole transport material free perovskite solar cells employing carbon counter electrodes

    Science.gov (United States)

    Xiao, Yuqing; Cheng, Nian; Kondamareddy, Kiran Kumar; Wang, Changlei; Liu, Pei; Guo, Shishang; Zhao, Xing-Zhong

    2017-02-01

    Doping of TiO2 by metal elements for the scaffold layer of the perovskite solar cells has been proved to be one of the effective methods to improve the power conversion efficiency. In the present work, we report the impact of doping of TiO2 nanoparticles with different amounts of tungsten (W) on the photovoltaic properties of hole transport material free perovskite solar cells (PSCs) that employ carbon counter electrode. Light doping with W (less than 1000 ppm) improves the power conversion efficiencies (PCEs) of solar cells by promoting the electron conductivity in the TiO2 layer which facilitates electron transfer and collection. With the incorporation of W, average efficiency of PSCs is increased from 9.1% for the un-doped samples to 10.53% for the 1000 ppm W-doped samples, mainly originates from the increase of short circuit current density and fill factor. Our champion cell exhibits an impressive PCE of 12.06% when using the 1000 ppm W-doped TiO2 films.

  17. Carbon Nanotubes Counter Electrode for Dye-Sensitized Solar Cells Application

    Directory of Open Access Journals (Sweden)

    Drygała A.

    2016-06-01

    Full Text Available The influence of the carbon nanotubes counter electrode deposited on the FTO glass substrates on the structure and optoelectrical properties of dye-sensitized solar cells counter electrode (CE was analysed. Carbon materials have been applied in DSSC s in order to produce low-cost solar cells with reasonable efficiency. Platinum is a preferred material for the counter electrode because of its high conductivity and catalytic activity. However, the costs of manufacturing of the platinum counter electrode limit its use to large-scale applications in solar cells. This paper presents the results of examining the structure and properties of the studied layers, defining optical properties of conductive layers and electrical properties of dye-sensitized solar cells manufactured with the use of carbon nanotubes.

  18. Gold nanoparticle decorated multi-walled carbon nanotubes as counter electrode for dye sensitized solar cells.

    Science.gov (United States)

    Kaniyoor, Adarsh; Ramaprabhu, Sundara

    2012-11-01

    A novel counter electrode material for dye sensitized solar cells (DSSCs) composed of nanostructured Au particles decorated on functionalized multi-walled carbon nanotubes (f-MWNTs) is demonstrated for the first time. MWNTs synthesized by catalytic chemical vapor deposition technique are purified and functionalized by treating with concentrated acids. Au nanoparticles are decorated on f-MWNTs by a rapid and facile microwave assisted polyol reduction method. The materials are characterized by X-ray diffractometry, Fourier transform infra red spectroscopy and electron microscopy. The DSSC fabricated with Au/f-MWNTs based counter electrode shows enhanced power conversion efficiency (eta) of 4.9% under AM 1.5G simulated solar radiation. In comparison, the reference DSSCs fabricated with f-MWNTs and Pt counter electrodes show eta of 2.1% and 4.5%. This high performance of Au/f-MWNTs counter electrode is investigated using electrochemical impedance spectroscopy and cyclic voltammetry studies.

  19. Electrochromic Performance of Nanocomposite Nickel Oxide Counter Electrodes Containing Lithium and Zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Engtrakul, Chaiwat [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lin, Feng [Formerly NREL; Colorado School of Mines; Montano, Manuel [Colorado School of Mines; Tian, Chixia [Colorado School of Mines; Ji, Yazhou [Colorado School of Mines; Nordlund, Dennis [SLAC National Accelerator Laboratory; Weng, Tsu-Chien [SLAC National Accelerator Laboratory; Moore, Rob G. [SLAC National Accelerator Laboratory; Gillaspie, Dane T. [Formerly NREL; Jones, Kim M. [Formerly NREL; Dillon, Anne C. [Formerly NREL; Richards, Ryan M. [Colorado School of Mines

    2013-12-02

    Nickel oxide materials are suitable for counter electrodes in complementary electrochromic devices. The state-of-the-art nickel oxide counter electrode materials are typically prepared with multiple additives to enhance peformance. Herein, nanocomposite nickel oxide counter electrodes were fabricated via RF magnetron co-sputtering from Ni-Zr alloy and Li2O ceramic targets. The as-deposited nanocomposite counter electrodes were characterized with inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and X-ray absorption spectroscopy (XAS). It was found that the stoichiometry, crystal structure and electronic structure of the nickel oxide-based materials could be readily tuned by varying the Li2O sputter deposition power level. Comprehensive electrochromic evaluation demonstrated that the performance of the nickel oxide-based materials was dependent on the overall Li stoichiometry. Overall, the nanocomposite nickel oxide counter electrode containing lithium and zirconium synthesized with a Li2O deposition power of 45 W exhibited the optimal performance with an optical modulation of 71% and coloration efficiency of 30 cm2/C at 670 nm in Li-ion electrolyte.

  20. Preparation and properties of low-cost graphene counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Wu, Qishuang; Shen, Yue; Wang, Qiandi; Gu, Feng; Cao, Meng; Wang, Linjun

    2013-12-01

    With the advantages of excellent electrical properties, high catalytic activity and low-cost preparation, Graphene is one of the most expected carbon materials to replace the expensive Pt as counter electrodes for dye-sensitized solar cells (DSSCs). In this paper, graphene counter electrodes were obtained by simple doctor-blade coating method on fluorine tin oxides (FTOs). The samples were investigated by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscope (SEM). Then the low-cost graphene electrodes were applied in typical sandwich-type DSSCs with TiO2 or ZnO as photoanodes, and their photoelectric conversion efficiency (η) were about 4.34% and 2.28%, respectively, which were a little lower than those of Pt electrodes but much higher than those of graphite electrodes. This law was consistent with the test results of electrochemical impedance spectroscopy (EIS). Low-cost graphene electrodes can be applied in DSSCs by process optimization.

  1. Novel one pot stoichiometric synthesis of nickel sulfide nanomaterials as counter electrodes for QDSSCs

    Energy Technology Data Exchange (ETDEWEB)

    Mani, A. Daya; Deepa, Melepurath [Department of Chemistry, IIT Hyderabad, Yeddumailaram 502 205 (India); Xanthopoulos, N. [Ecole Polytechnique Federale de Lausanne (EPFL), CH-Lausanne (Switzerland); Subrahmanyam, Ch, E-mail: csubbu@iith.ac.in [Department of Chemistry, IIT Hyderabad, Yeddumailaram 502 205 (India)

    2014-11-14

    Solution combustion synthesis has been used for the first time to synthesize metal sulfide nanomaterials. Selective stoichiometric synthesis of nickel sulfide nanomaterials was achieved in a single step by using combustion synthesis under ambient conditions and the samples were tested as counter electrodes in a typical quantum dot sensitized solar cell (QDSSC). By varying the oxidant/fuel ratio, different stoichiometric nickel sulfide nanomaterials were obtained. Interestingly, a maximum of fourfold increase in efficiency (1.1%) was achieved with nickel sulfide counter electrode when compared to the Pt counter electrode (0.25%). This can be attributed to the less charge transfer resistance offered by nickel sulfide samples compared to Pt, which was confirmed by electrochemical impedance spectroscopy. Among different stoichiometric compositions of nickel sulfide, Ni{sub 3}S{sub 2} was found to exhibit the least charge transfer resistance and superior solar cell efficiency. The present study describes a novel selective stoichiometric synthetic approach and facile fabrication procedure for low cost counter electrode materials in QDSSCs. - Highlights: • Novel and facile phase selective synthesis of nickel sulfide nanomaterials. • A different sensitization approach of TiO{sub 2} with CdS. • A simple paint approach for working and counter electrode fabrication. • Fourfold increase of efficiency with Ni{sub 3}S{sub 2} compared to the conventional Pt.

  2. Heuristic method of fabricating counter electrodes in dye-sensitized solar cells based on a PEDOT:PSS layer as a catalytic material

    Science.gov (United States)

    Edalati, Sh; Houshangi far, A.; Torabi, N.; Baneshi, Z.; Behjat, A.

    2017-02-01

    Poly(3,4-ethylendioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was deposited on a fluoride-doped tin oxide glass substrate using a heuristic method to fabricate platinum-free counter electrodes for dye-sensitized solar cells (DSSCs). In this heuristic method a thin layer of PEDOT:PPS is obtained by spin coating the PEDOT:PSS on a Cu substrate and then removing the substrate with FeCl3. The characteristics of the deposited PEDOT:PSS were studied by energy dispersive x-ray analysis and scanning electron microscopy, which revealed the micro-electronic specifications of the cathode. The aforementioned DSSCs exhibited a solar conversion efficiency of 3.90%, which is far higher than that of DSSCs with pure PEDOT:PSS (1.89%). This enhancement is attributed not only to the micro-electronic specifications but also to the HNO3 treatment through our heuristic method. The results of cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and Tafel polarization plots show the modified cathode has a dual function, including excellent conductivity and electrocatalytic activity for iodine reduction.

  3. Low Sheet Resistance Counter Electrode in Dye-sensitized Solar Cell

    Institute of Scientific and Technical Information of China (English)

    Gui Qiang WANG; Rui Feng LIN; Miao WANG; Chang Neng ZHANG; Yuan LIN; Xu Rui XIAO; Xue Ping LI

    2004-01-01

    In order to search for the high efficiency and low sheet resistance counter electrode in dye-sensitized solar cell, we used Ti plate as the conducting substrate to prepare the counter electrode by thermal decomposition of H2PtCl6. Ti plate counter electrode shows low sheet resistance, good reflecting performance and matching kinetics. The dye-sensitized solar cell with the Ti plate counter electrode shows better photovoltaic performance than that of the cell with the fluorine-doped tin oxide-coated glass counter electrode.

  4. Electrostatic atomization: Effect of electrode materials on electrostatic atomizer performance

    Science.gov (United States)

    Sankaran, Abhilash; Staszel, Christopher; Kashir, Babak; Perri, Anthony; Mashayek, Farzad; Yarin, Alexander

    2016-11-01

    Electrostatic atomization was studied experimentally with a pointed electrode in a converging nozzle. Experiments were carried out on poorly conductive canola oil where it was observed that electrode material may affect charge transfer. This points at the possible faradaic reactions that can occur at the surfaces of the electrodes. The supply voltage is applied to the sharp electrode and the grounded nozzle body constitutes the counter-electrode. The charge transfer is controlled by the electrochemical reactions on both the electrodes. The electrical performance study of the atomizer issuing a charged oil jet was conducted using three different nozzle body materials - brass, copper and stainless steel. Also, two sharp electrode materials - brass and stainless steel - were tested. The experimental results revealed that both the nozzle body material, as well as the sharp electrode material affected the spray and leak currents. Moreover, the effect of the sharp electrode material is quite significant. This research is supported by NSF Grant 1505276.

  5. CoS-Graphene Composite Counter Electrode for High Performance Dye-Sensitized Solar Cell.

    Science.gov (United States)

    Wang, Fen; Wu, Congcong; Tan, Yuan; Jin, Tetsuro; Chi, Bo; Pu, Jian; Jian, Li

    2015-02-01

    CoS-graphene composite counter electrode for dye-sensitized solar cell (DSSC) was prepared by coating hydrothermal synthesized CoS with graphene onto the FTO conductive glass. SEM shows that CoS particles are uniformly dispersed in the graphene. The result confirms that the prepared composite counter electrode is of highly electrocatalytic activity towards iodine reduction, which is even better than Pt electrode. And cyclic voltammetry measurement also shows that the composite counter electrode has good stability after 100 scan cycles. DSSC with CoS-graphene as composite counter electrode achieves a maximum power conversion efficiency of 6.31%, which is better than Pt electrode.

  6. Thermally exfoliated graphene based counter electrode for low cost dye sensitized solar cells

    Science.gov (United States)

    Kaniyoor, Adarsh; Ramaprabhu, Sundara

    2011-06-01

    Graphene obtained from thermal exfoliation of graphite oxide are highly wrinkled and have large surface area. Their wrinkled nature is expected to give them excellent catalytic activity. Herein, we demonstrate the use of thermally exfoliated graphene (TEG) as cost effective electrocatalyst for the tri-iodide reduction in dye sensitized solar cells (DSSCs). X-ray diffraction, Raman and Infra red spectroscopy and electron microscopy studies confirm the defective and wrinkled nature of TEG. BET surface area measurement show a large surface area of ˜ 470 m2/g. The counter electrode was fabricated by drop casting a slurry of TEG dispersed in a Nafion:Ethanol solution on fluorine doped tin oxide (FTO) substrates. The use of Nafion prevented film "peel off," thus ensuring a good substrate adhesion. Electrochemical impedance spectroscopy reveals that TEG had a catalytic performance comparable to that of Pt, suggesting its use as counter electrode material. As expected, the DSSC fabricated with Nafion solubilized TEG/FTO as counter electrode shows an efficiency of about 2.8%, comparable to Pt counter electrode based DSSC which has an efficiency of about 3.4%.

  7. Hollow platinum alloy tailored counter electrodes for photovoltaic applications

    Science.gov (United States)

    Li, Pinjiang; Zhang, Yange; Fa, Wenjun; Yang, Xiaogang; Wang, Liang

    2017-08-01

    Without sacrifice of photovoltaic performances, low-platinum alloy counter electrodes (CEs) are promising in bringing down the fabrication cost of dye-sensitized solar cells (DSSCs). We present here the realization of ZnO nanostructure assisted hollow platinum-nickel (PtNi) alloy microstructure CEs with a simple hydrothermal methods and maximization of electrocatalytic behaviors by tuning Zn precursors. The maximal power conversion efficiency is up to 8.74% for the liquid-junction dye-sensitized solar cells with alloyed PtNi0.41 electrode, yielding a 37.6% cell efficiency enhancement in comparison with pristine solar cell from planar Pt electrode. Moreover, the dissolution-resistant and charge-transfer abilities toward I-/I3- redox electrolyte have also been markedly enhanced due to competitive dissolution reactions and alloying effects.

  8. Copper indium disulfide nanocrystals supported on carbonized chicken eggshell membranes as efficient counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Wang, Lidan; He, Jianxin; Zhou, Mengjuan; Zhao, Shuyuan; Wang, Qian; Ding, Bin

    2016-05-01

    A domestic waste, chicken eggshell membrane (ESM), is used as a raw material to fabricate carbonized ESM loaded with chalcopyrite CuInS2 nanocrystals (denoted CESM-CuInS2) by a simple liquid impregnation and carbonization method. The CESM-CuInS2 composite possesses a natural three-dimensional macroporous network structure in which numerous CuInS2 nanocrystals with a size of about 25 nm are inlaid in carbon submicron fibers that form a microporous network. The CESM-CuInS2 composite is used as the counter electrode in a dye-sensitized solar cell (DSSC) and its photoelectric performance is tested. The DSSC with a CESM-CuInS2 counter electrode exhibits a short-circuit current density of 12.48 mA cm-2, open-circuit voltage of 0.78 V and power conversion efficiency of 5.8%; better than the corresponding values for a DSSC with a CESM counter electrode, and comparable to that of a reference DSSC with a platinum counter electrode. The favorable photoelectric performance of the CESM-CuInS2 counter electrode is attributed to its hierarchical structure, which provides a large specific surface area and numerous catalytically active sites to facilitate the oxidation of the electrolyte. This new composite material has many advantages, such as low cost and simple preparation, compared with Pt and pure CuInS2 counter electrodes.

  9. Photovoltachromic device with a micropatterned bifunctional counter electrode.

    Science.gov (United States)

    Cannavale, Alessandro; Manca, Michele; De Marco, Luisa; Grisorio, Roberto; Carallo, Sonia; Suranna, Gian Paolo; Gigli, Giuseppe

    2014-02-26

    A photovoltachromic window can potentially act as a smart glass skin which generates electric energy as a common dye-sensitized solar cell and, at the same time, control the incoming energy flux by reacting to even small modifications in the solar radiation intensity. We report here the successful implementation of a novel architecture of a photovoltachromic cell based on an engineered bifunctional counter electrode consisting of two physically separated platinum and tungsten oxide regions, which are arranged to form complementary comb-like patterns. Solar light is partially harvested by a dye-sensitized photoelectrode made on the front glass of the cell which fully overlaps a bifunctional counter electrode made on the back glass. When the cell is illuminated, the photovoltage drives electrons into the electrochromic stripes through the photoelectrochromic circuit and promotes the Li(+) diffusion towards the WO3 film, which thus turns into its colored state: a photocoloration efficiency of 17 cm(2) min(-1) W(-1) at a wavelength of 650 nm under 1.0 sun was reported along with fast response (coloration time photovoltaic functionality was also retained due to the copresence of the independently switchable micropatterned platinum electrode.

  10. Anthocyanin-sensitized solar cells using carbon nanotube films as counter electrodes

    Science.gov (United States)

    Zhu, Hongwei; Zeng, Haifeng; Subramanian, Venkatachalam; Masarapu, Charan; Hung, Kai-Hsuan; Wei, Bingqing

    2008-11-01

    Carbon nanotube (CNT) films have been used as counter electrodes in natural dye-sensitized (anthocyanin-sensitized) solar cells to improve the cell performance. Compared with conventional cells using natural dye electrolytes and platinum as the counter electrodes, cells with a single-walled nanotube (SWNT) film counter electrode show comparable conversion efficiency, which is attributed to the increase in short circuit current density due to the high conductivity of the SWNT film.

  11. A long-term analysis of Pt counter electrodes for Dye-sensitized Solar Cells exploiting a microfluidic housing system

    Energy Technology Data Exchange (ETDEWEB)

    Sacco, Adriano, E-mail: adriano.sacco@iit.it [Center for Space Human Robotics @Polito, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Pugliese, Diego; Lamberti, Andrea [Applied Science and Technology Department, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Castellino, Micaela; Chiodoni, Angelica [Center for Space Human Robotics @Polito, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Virga, Alessandro [Applied Science and Technology Department, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Bianco, Stefano [Center for Space Human Robotics @Polito, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Applied Science and Technology Department, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2015-07-01

    The study of the degradation process occurring in Dye-sensitized Solar Cells (DSCs) is still a hot topic, in view of the final industrialization and application of this class of devices. Currently the long-term analysis of DSCs is carried out on the entire devices, while the monitoring of cell components cannot be performed in situ directly on the materials, but only through indirect methods. In this paper we report on the analysis of two different kinds of Pt counter electrodes through direct measurements performed under real operating conditions, thanks to the use of a home-made microfluidic housing system, which allows the opening and the investigation of the cell components. The counter electrode samples were studied through X-Ray Photoelectron Spectroscopy, Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, UV–visible Spectroscopy and Electrochemical Impedance Spectroscopy for a period longer than 1 year. The results showed that the performances of both classes of Pt counter electrodes remained stable for all the investigation period, despite some slight variation of the morphology. DSCs fabricated employing aged counter electrodes exhibited the same photovoltaic performance behavior of reference cells using fresh-produced counter electrodes, thus demonstrating that both class of materials do not undergo degradation during normal operating conditions. - Highlights: • The analysis of Pt counter electrodes for Dye-sensitized Solar Cells was carried out. • Two families of counter electrodes were studied for a period longer than 1 year. • The analyzed samples were investigated in real operating condition. • A small detachment of the Pt clusters in the thermal samples was observed. • The charge transfer properties remained unchanged for all the investigation period.

  12. Recent Progress of Counter Electrodes in Nanocrystalline Dye-sensitized Solar Cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Dye-sensitized solar cell (DSC) consists a combination of several different materials: photoanodes with nanoparticulated semiconductors, sensitizers, electrolytes and counter electrodes (CEs). Each materials performs specific task for the conversion of solar energy into electricity. The main function of CE is to transfer electrons to the redox electrolyte and regenerate iodide ion. The work of CE is mainly focused on the studies of the kinetic performance and stability of the traditional CEs to improve the overall efficiency of DSC, seeking novel design concepts or new materials. In this review, the development and research progress of different CEmaterials and their electrochemical performance, and the problems are discussed.

  13. Indium- and Platinum-Free Counter Electrode for Green Mesoscopic Photovoltaics through Graphene Electrode and Graphene Composite Catalysts: Interfacial Compatibility.

    Science.gov (United States)

    Yin, Jie; Zhou, Huawei; Liu, Zhicheng; Nie, Zhonghao; Li, Yinhao; Qi, Xuan; Chen, Baoli; Zhang, Yingtian; Zhang, Xianxi

    2016-03-01

    The scarcity and noble indium and platinum (Pt) are important elements in photoelectric nanomaterials. Therefore, development of low cost alternative materials to meet different practical applications is an urgent need. Two-dimensional (2D) layered graphene (GE) with unique physical, mechanical, and electrical properties has recently drawn a great deal of attention in various optoelectronic fields. Herein, the large scale (21 cm × 15 cm) high-quality single layer graphene (SLG) and multilayer graphene on a flexible plastic substrate PET were controllably prepared through layer-by-layer (LBL) transfer using the thermal release adhesive transfer method (TRA-TM). Transmission and antibending performance based on PET/GE were superior to traditional PET/ITO. The square resistance of a nine-layer graphene electrode reached approximately 58 Ω. Combined with our newly developed and highly effective Fe3O4@RGO (reduced graphene oxide) catalyst, the power conversion efficiency of the dye-sensitized solar cell (DSC) using flexible PET/GE conductive substrate was comparable to that of the DSC using the PET/ITO substrate. The desirable performance of PET/GE/Fe3O4@RGO counter electrodes (low-cost indium- and platinum-free counter electrodes) is attributed to the interfacial compatibility between 2D graphene composite catalyst (Fe3O4@RGO) and 2D PET/GE conductive substrate. In addition, DSCs that use only PET/GE (without Fe3O4@RGO catalyst) as counter electrodes can also achieve a photocurrent density of 6.30 mA cm(-2). This work is beneficial for fundamental research and practical applications of graphene and graphene composite in photovoltaics, photocatalytic water splitting, supercapacitors.

  14. Synthesis of novel Cu2S nanohusks as high performance counter electrode for CdS/CdSe sensitized solar cell

    Science.gov (United States)

    Kamaja, Chaitanya Krishna; Devarapalli, Rami Reddy; Dave, Yasha; Debgupta, Joyashish; Shelke, Manjusha V.

    2016-05-01

    An important component of quantum dot sensitized solar cells (QDSSC) is the counter electrode which mediates the regeneration of oxidized quantum dots by reducing the polysulphide electrolyte. However, design and synthesis of an efficient counter electrode material is a challenging task. Herein, we report the synthesis of a unique Cu2S nanohusks directly on FTO coated glass substrates by electrodeposition and used as a counter electrode in QDSSC. When these electrodes are used for the reduction of polysulfide electrolyte in QDSSC, they exhibit higher catalytic activity and photovoltaic performance as compared to the Platinum counter electrode. The power conversion efficiency of about 4.68% has been achieved by optimizing the deposition time of Cu2S.

  15. Transparent platinum counter electrode for efficient semi-transparent dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Iefanova, Anastasiia; Nepal, Jeevan; Poudel, Prashant; Davoux, Daren; Gautam, Umesh [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States); Mallam, Venkataiah [Chemistry and Biochemistry Department, South Dakota State University, Brookings, SD 57006 (United States); Qiao, Qiquan [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States); Logue, Brian [Chemistry and Biochemistry Department, South Dakota State University, Brookings, SD 57006 (United States); Baroughi, Mahdi Farrokh, E-mail: m.farrokhbaroughi@sdstate.edu [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States)

    2014-07-01

    A method for fabrication of highly transparent platinum counter electrodes (CEs) has been developed based on spray coating of Pt nanoparticles (NPs) on hot substrates. This method leads to 86% reduction in Pt consumption reducing the Pt cost per peak watt of counter electrode from $0.79/Wp down to $0.11/Wp compared to the conventional Pt counter electrodes made by sputter deposition. The simplicity and low cost of this method provide a basis for an up-scalable fabrication process. The Pt NP layer is over 88% transparent, leading to overall transparency of 80% when incorporated with indium tin oxide/glass substrates for functional counter electrodes. This counter electrode exhibits a large surface area and high catalytic activity, comparable to that of the conventional opaque CEs. Semi-transparent dye-sensitized solar cells fabricated based on this counter electrode showed 6.17% power conversion efficiency. - Highlights: • Counter electrode (CE) prepared by spraying nanoparticle (NP) Pt on hot substrate. • Low cost and scalable fabrication process of CE. • The spray deposited CE uses 10 times less Pt compared to the sputtering method. • The CE is 80% transparent and exhibits a large surface and high catalytic activity. • A semitransparent dye-sensitized solar cell with Pt NP CE was 6.17% efficient.

  16. RF Sputtered Iridium (Ir) Film as a Counter Electrode for Dye-Sensitized Solar Cells

    Science.gov (United States)

    Mokurala, Krishnaiah; Kamble, Anvita; Bhargava, Parag; Mallick, Sudhanshu

    2015-11-01

    Iridium (Ir) films were deposited on fluorine-doped tin oxide substrate by radio-frequency sputtering at room temperature and the as-deposited films were used as counter electrodes (CE) for dye-sensitized solar cells (DSSC). The photo conversion efficiency (PCE) of DSSC fabricated with Ir-based CE was 7.2%. Electrocatalytic activity and electrochemical data for Ir-based CE were compared with those for conventional Pt-based CE. The results were indicative of potential use of Ir as an alternative CE material for DSSC.

  17. Fractals in several electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chunyong, E-mail: zhangchy@njau.edu.cn [Department of Chemistry, College of Science, Nanjing Agricultural University, Nanjing 210095 (China); Suzhou Key Laboratory of Environment and Biosafety, Suzhou Academy of Southeast University, Dushuhu lake higher education town, Suzhou 215123 (China); Wu, Jingyu [Department of Chemistry, College of Science, Nanjing Agricultural University, Nanjing 210095 (China); Fu, Degang [Suzhou Key Laboratory of Environment and Biosafety, Suzhou Academy of Southeast University, Dushuhu lake higher education town, Suzhou 215123 (China); State Key Laboratory of Bioelectronics, Southeast University, Nanjing 210096 (China)

    2014-09-15

    Highlights: • Fractal geometry was employed to characterize three important electrode materials. • The surfaces of all studied electrodes were proved to be very rough. • The fractal dimensions of BDD and ACF were scale dependent. • MMO film was more uniform than BDD and ACF in terms of fractal structures. - Abstract: In the present paper, the fractal properties of boron-doped diamond (BDD), mixed metal oxide (MMO) and activated carbon fiber (ACF) electrode have been studied by SEM imaging at different scales. Three materials are self-similar with mean fractal dimension in the range of 2.6–2.8, confirming that they all exhibit very rough surfaces. Specifically, it is found that MMO film is more uniform in terms of fractal structure than BDD and ACF. As a result, the intriguing characteristics make these electrodes as ideal candidates for high-performance decontamination processes.

  18. A new type counter electrode for dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    JI WeiWei; CAI Ning; ZHAO Ying; ZHANG XiaoDan; SUN Jian; WEI ChangChun; YUAN CunDa; LI Yuan; SU Yan; XIONG ShaoZhen

    2009-01-01

    A new type counter electrode for dye-sensitized solar cells (DSCs) was proposed which consists of aubstrate, aluminum film and platinum film. The new type counter electrode can obviously improve the photoelectric conversion efficiency of DSCs from 3.46% to 7.07% under the standard AM1.5 irradiation condition. Advantages and shortcomings of this new type counter electrode in terms of electrical properties, optical properties and anti-corrosive properties were analyzed. As a result, some improvements were proposed.

  19. Cost–effective Polythiophene Counter Electrodes for Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Tolu Merve Celik

    2016-01-01

    Full Text Available Dye sensitized solar cells (DSSCs are most promising devices among third–generation solar cells because of low cost, easy production, environmental friendliness, and relatively high conversion efficiency. Counter electrode (CE, which is an important component in DSSCs, functions as an electron transfer agent as well as the regenerator of redox couple. Hitherto, various methods and materials were used to prepare different counter electrodes.Among these materials, conducting polymers have been widely investigated and employed in various applications such as sensors, supercapacitors, energy storage devices, DSSCs and others. In this study, Polythiophene (PTh conducting polymer was successfully synthesized by electrochemical deposition method, and employed as an alternative to expensive platinum (Pt CE for DSSC. Besides, PTh conducting polymer was electrochemically deposited via cyclic voltammetry method on FTO substrates. The morphology of the PTh film was characterized by SEM and AFM. Finally, the photovoltaic performance of PTh CE based DSSC was compared with PEDOT CE based device. This new concept—along with promising electrocatalytic activity and facile electron transfer—provides a new approach to enhance the photovoltaic performances of Pt–free DSSCs.

  20. Comparison of performance parameters of poly(3,4 ethylenedioxythiophene) (PEDOT) based electrochromic device on glass with and without counter electrode

    Indian Academy of Sciences (India)

    S Sindhu; K Narasimha Rao; E S R Gopal

    2008-02-01

    Conjugated polymers are promising materials for electrochromic device technology. Aqueous dispersions of poly(3,4-ethylenedioxythiophene)-(PEDOT) were spin coated onto transparent conducting oxide (TCO) coated glass substrates. A seven-layer electrochromic device was fabricated with the following configuration: glass/transparent conducting oxide (TCO)/PEDOT (main electrochromic layer)/gel electrolyte/prussian blue (counter electrode)/TCO/glass. The device fabricated with counter electrode (Prussian blue) showed a contrast of 18% and without counter electrode showed visible contrast of 5% at 632 nm at a voltage of 1.9 V. The comparison of the device is done in terms of the colouration efficiency of the devices with and without counter electrode.

  1. Rapid atmospheric pressure plasma jet processed reduced graphene oxide counter electrodes for dye-sensitized solar cells.

    Science.gov (United States)

    Liu, Hsiao-Wei; Liang, Sheng-Ping; Wu, Ting-Jui; Chang, Haoming; Kao, Peng-Kai; Hsu, Cheng-Che; Chen, Jian-Zhang; Chou, Pi-Tai; Cheng, I-Chun

    2014-09-10

    In this work, we present the use of reduced graphene oxide (rGO) as the counter electrode materials in dye-sensitized solar cells (DSSCs). rGO was first deposited on a fluorine-doped tin oxide glass substrate by screen-printing, followed by post-treatment to remove excessive organic additives. We investigated the effect of atmospheric pressure plasma jet (APPJ) treatment on the DSSC performance. A power conversion efficiency of 5.19% was reached when DSSCs with an rGO counter electrode were treated by APPJs in the ambient air for a few seconds. For comparison, it requires a conventional calcination process at 400 °C for 15 min to obtain comparable efficiency. Scanning electron micrographs show that the APPJ treatment modifies the rGO structure, which may reduce its conductivity in part but simultaneously greatly enhances its catalytic activity. Combined with the rapid removal of organic additives by the highly reactive APPJ, DSSCs with APPJ-treated rGO counter electrode show comparable efficiencies to furnace-calcined rGO counter electrodes with greatly reduced process time. This ultrashort process time renders an estimated energy consumption per unit area of 1.1 kJ/cm(2), which is only one-third of that consumed in a conventional furnace calcination process. This new methodology thus saves energy, cost, and time, which is greatly beneficial to future mass production.

  2. Redox electrode materials for supercapatteries

    Science.gov (United States)

    Yu, Linpo; Chen, George Z.

    2016-09-01

    Redox electrode materials, including transition metal oxides and electronically conducting polymers, are capable of faradaic charge transfer reactions, and play important roles in most electrochemical energy storage devices, such as supercapacitor, battery and supercapattery. Batteries are often based on redox materials with low power capability and safety concerns in some cases. Supercapacitors, particularly those based on redox inactive materials, e.g. activated carbon, can offer high power output, but have relatively low energy capacity. Combining the merits of supercapacitor and battery into a hybrid, the supercapattery can possess energy as much as the battery and output a power almost as high as the supercapacitor. Redox electrode materials are essential in the supercapattery design. However, it is hard to utilise these materials easily because of their intrinsic characteristics, such as the low conductivity of metal oxides and the poor mechanical strength of conducting polymers. This article offers a brief introduction of redox electrode materials, the basics of supercapattery and its relationship with pseudocapacitors, and reviews selectively some recent progresses in the relevant research and development.

  3. Conducting polymers based counter electrodes for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Veerender, P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Saxena, Vibha, E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Gusain, Abhay, E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Jha, P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Koiry, S. P., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Chauhan, A. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Aswal, D. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com; Gupta, S. K., E-mail: veeru1009@gmail.com, E-mail: veeru1009@gmail.com [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai - 400085 (India)

    2014-04-24

    Conducting polymer films were synthesized and employed as an alternative to expensive platinum counter electrodes for dye-sensitized solar cells. poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) thin films were spin-coated and polypyrrole films were electrochemically deposited via cyclic voltammetry method on ITO substrates. The morphology of the films were imaged by SEM and AFM. These films show good catalytic activity towards triiodide reduction as compared to Pt/FTO electrodes. Finally the photovoltaic performance of DSSC fabricated using N3 dye were compared with PT/FTO, PEDOT/ITO, and e-PPy counter electrodes.

  4. Conducting polymers based counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Veerender, P.; Saxena, Vibha; Gusain, Abhay; Jha, P.; Koiry, S. P.; Chauhan, A. K.; Aswal, D. K.; Gupta, S. K.

    2014-04-01

    Conducting polymer films were synthesized and employed as an alternative to expensive platinum counter electrodes for dye-sensitized solar cells. poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) thin films were spin-coated and polypyrrole films were electrochemically deposited via cyclic voltammetry method on ITO substrates. The morphology of the films were imaged by SEM and AFM. These films show good catalytic activity towards triiodide reduction as compared to Pt/FTO electrodes. Finally the photovoltaic performance of DSSC fabricated using N3 dye were compared with PT/FTO, PEDOT/ITO, and e-PPy counter electrodes.

  5. One-Step Electrochemical Polymerization of Polyaniline Flexible Counter Electrode Doped by Graphene

    Directory of Open Access Journals (Sweden)

    Qi Qin

    2016-01-01

    Full Text Available To improve the photoelectric property of polyaniline (PANI counter electrode using for flexible dye-sensitized solar cell (DSSC, graphene (GN was doped in PANI films covered on flexible conducting substrate by one-step electrochemical method, and then GN/PANI composites are characterized by scanning electron microscope (SEM, fourier transform infrared spectroscopy (FTIR, four probe instrument, and so on. The results show that PANI particles can be electrodeposited on the surface of GN sheets as the potential rising to 2.0 V. This formed unique PANI-GN-PANI lamellar structure owing to the strong interaction of conjugated π electron between GN and PANI results in the superior conductivity and catalytic performance of GN/PANI electrode. The maximum conversion efficiency of dye-sensitized solar cell with this counter electrode reaches 4.31%, which is much higher than that of GN-free PANI counter electrode.

  6. Electrode materials for rechargeable battery

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Christopher; Kang, Sun-Ho

    2015-09-08

    A positive electrode is disclosed for a non-aqueous electrolyte lithium rechargeable cell or battery. The electrode comprises a lithium containing material of the formula Na.sub.yLi.sub.xNi.sub.zMn.sub.1-z-z'M.sub.z'O.sub.d, wherein M is a metal cation, x+y>1, 0material preferably has a spinel or spinel-like component in its structure. The value of y preferably is less than about 0.2, and M comprises one or more metal cations selected preferably from one or more monovalent, divalent, trivalent or tetravalent cations, such as Mg.sup.2+, Co.sup.2+, Co.sup.3+, B.sup.3+, Ga.sup.3+, Fe.sup.2+, Fe.sup.3+, Al.sup.3+, and Ti.sup.4+. The electrode material can be synthesized using an ion-exchange reaction with a lithium salt in an organic-based solvent to partially replace sodium ions of a precursor material with lithium ions.

  7. A flexible polypyrrole-coated fabric counter electrode for dye-sensitized solar cells

    Science.gov (United States)

    Xu, Jie; Li, Meixia; Wu, Lei; Sun, Yongyuan; Zhu, Ligen; Gu, Shaojin; Liu, Li; Bai, Zikui; Fang, Dong; Xu, Weilin

    2014-07-01

    The current dye-sensitized solar cell (DSSC) technology is mostly based on fluorine doped tin oxide (FTO) coated glass substrate. The main problem with the FTO glass substrate is its rigidity, heavyweight and high cost. DSSCs with a fabric as substrate not only offer the advantages of flexibility, stretchability and light mass, but also provide the opportunities for easy implantation to wearable electronics. Herein, a novel fabric counter electrode (CE) for DSSCs has been reported employing a daily-used cotton fabric as substrate and polypyrrole (PPy) as catalytic material. Nickel (Ni) is deposited on the cotton fabric as metal contact by a simple electroless plating method to replace the expensive FTO. PPy is synthesized by in situ polymerization of pyrrole monomer on the Ni-coated fabric. The fabric CE shows sufficient catalytic activity towards the reduction of I3-. The DSSC fabricated using the fabric CE exhibits power conversion efficiency of ∼3.30% under AM 1.5.

  8. Fully printable transparent monolithic solid-state dye-sensitized solar cell with mesoscopic indium tin oxide counter electrode.

    Science.gov (United States)

    Yang, Ying; Ri, Kwangho; Rong, Yaoguang; Liu, Linfeng; Liu, Tongfa; Hu, Min; Li, Xiong; Han, Hongwei

    2014-09-07

    We present a new transparent monolithic mesoscopic solid-state dye-sensitized solar cell based on trilamellar films of mesoscopic TiO2 nanocrystalline photoanode, a ZrO2 insulating layer and an indium tin oxide counter electrode (ITO-CE), which were screen-printed layer by layer on a single substrate. When the thickness of the ITO-CE was optimized to 2.1 μm, this very simple and fully printable solid-state DSSC with D102 dye and spiro-OMeTAD hole transport materials presents efficiencies of 1.73% when irradiated from the front side and 1.06% when irradiated from the rear side under a standard simulated sunlight condition (AM 1.5 Global, 100 mW cm(-2)). Higher parameters could be expected with a better transparent mesoscopic counter electrode and hole conductor for the printable monolithic mesoscopic solid-state DSSC.

  9. Vanadium oxide (VO) based low cost counter electrode in dye sensitized solar cell (DSSC) applications

    Energy Technology Data Exchange (ETDEWEB)

    Vijayakumar, P.; Pandian, Muthu Senthil; Ramasamy, P., E-mail: ramasamyp@ssn.edu.in [SSN Research Centre, SSN College of Engineering, Kalavakkam-603 110, Chennai, Tamilnadu (India)

    2015-06-24

    Vanadium oxide nanostars were synthesized by chemical method. The prepared Vanadium oxide nanostars are introduced into dye sensitized solar cell (DSSC) as counter electrode (CE) catalyst to replace the expensive platinum (Pt). The products were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) method. The photovoltaic performance of the VO as counter electrode based DSSC was evaluated under simulated standard global AM 1.5G sunlight (100 mW/cm{sup 2}). The solar to electrical energy conversion efficiency (η) of the DSSC was found to be 0.38%.This work expands the Counter electrode catalyst, which can help to reduce the cost of DSSC and thereby encourage their fundamental research and commercial application.

  10. Freestanding polypyrrole films as counter electrode for low cost dye sensitized solar cells

    Science.gov (United States)

    Jha, P.; Veerender, P.; Koiry, S. P.; Sridevi, C.; Chabbi, Pradnya; Samanta, S.; Chauhan, A. K.; Muthe, K. P.; Gadkari, S. C.

    2017-05-01

    Free standing polypyrrole films were synthesized using aqueous-organic interfacial polymerization. The electrical conductivity of these films was found to be higher when hexane(or benzene)-aqueous biphasic system is used. These high conductivity films were utilized as cost effective counter electrode to replace expansive Platinum in the fabrication of quasi-solid dye sensitized solar cells. The efficiency of DSSC was found to be 1.1%, which is close to that of 1.8% prepared using Pt as counter electrode.

  11. Increase in the DSSC efficiency when using metal-coated carbon nanowall counter electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangjoon; Choi, Wonseok [Hanbat National University, Daejeon (Korea, Republic of); Lim, Donggun [Korea National University of Transportation, Chungju (Korea, Republic of); Choi, Eunchang; Hong, Byungyou [Sungkyunkwan University, Suwon (Korea, Republic of)

    2014-08-15

    This research was conducted to improve the efficiency of dye-sensitized solar cells (DSSCs) using metal-layer-coated carbon nanowalls (CNWs) as counter electrodes. The CNWs were synthesized on a fluorine-doped tin-oxide (FTO) glass substrate in a microwave plasma-enhanced chemical vapor deposition (PECVD) system using methane (CH{sub 4}), and the CNWS were sputter-coated with metal films several times by using an RF magnetron sputtering system and four-inch metal targets (Cu, W and Ni, separately). Then, the metal-layer-coated CNWs were used as counter electrodes for manufacturing the DSCCs. The vertical and the surface conditions of the metal-coated CNWs used as the DSCC electrodes were characterized by their electrical variations through field-emission scanning electron microscopy (FE-SEM) and Hall measurements. Their optical characteristics were analyzed using UV-Vis equipment, and the energy conversion efficiencies of the DSSCs manufactured using the metal-layer-coated CNWs as the counter electrodes were measured. The results confirmed that the efficiency improved when the W-coated CNW was used as the counter electrode.

  12. Carbon nanotube/graphene nanocomposite as efficient counter electrodes in dye-sensitized solar cells.

    Science.gov (United States)

    Velten, Josef; Mozer, Attila J; Li, Dan; Officer, David; Wallace, Gordon; Baughman, Ray; Zakhidov, Anvar

    2012-03-02

    We demonstrated the replacement of the Pt catalyst normally used in the counter electrode of a dye-sensitized solar cell (DSSC) by a nanocomposite of dry spun carbon multi-walled nanotube (MWNT) sheets with graphene flakes (Gr-F). The effectiveness of this counter electrode on the reduction of the triiodide in the iodide/triiodide redox (I(-)/I(3)(-)) redox reaction was studied in parallel with the use of the dry spun carbon MWNT sheets alone and graphene flakes used independent of each other. This nanocomposite deposited onto fluorinated tin-oxide-coated glass showed improved catalytic behavior and power conversion efficiency (7.55%) beyond the use of the MWNTs alone (6.62%) or graphene alone (4.65%) for the triiodide reduction reaction in DSSC. We also compare the use of the carbon MWNT/Gr-F composite counter electrode with a DSSC using the standard Pt counter electrode (8.8%). The details of increased performance of graphene/MWNT composite electrodes as studied are discussed in terms of increased catalytic activity permitted by sharp atomic edges that arise from the structure of graphene flakes or the defect sites in the carbon MWNT and increased electrical conductivity between the carbon MWNT bundles by the graphene flakes.

  13. Application of Cu3InSnSe5 Heteronanostructures as Counter Electrodes for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Lou, Yue; Zhao, Wenjie; Li, Chunguang; Huang, He; Bai, Tianyu; Chen, Cailing; Liang, Chen; Shi, Zhan; Zhang, Dong; Chen, Xiao-Bo; Feng, Shouhua

    2017-05-31

    In this research, we reported the synthesis of quaternary Cu3InSnSe5 nanoparticles with uniform size distribution and morphology for the first time through delicate controls over the chemical reaction kinetics. On the basis of the preparation strategy of Cu3InSnSe5 nanoparticles, Pt-Cu3InSnSe5 and Au-Cu3InSnSe5 heteronanostructures were designed and yielded using a simple and efficient seed growth method. These two heteronanostructures remained monodispersed without presence of any Cu3InSnSe5 nanocrystal impurities. To explore their application potentials for dye-sensitized solar cells, counter electrodes consisting of individual Cu3InSnSe5, Pt-Cu3InSnSe5, or Au-Cu3InSnSe5 constituents were fabricated. Current density-voltage (J-V) characteristics evaluation reveals that Cu3InSnSe5 nanoparticles, Pt-Cu3InSnSe5 and Au-Cu3InSnSe5 heterostructured nanoparticles display a comparative power conversion efficiency (PCE) of 5.8%, 7.6%, and 6.5% to that of a Pt-based counter electrode (7.9%), respectively. As such, we believe that the reported preparation strategy could provide new insights to the design and manufacture of counter electrode materials with controlled structure, morphology, and optimized power conversion efficiency for dye-sensitized solar cells.

  14. Recent advances in dye-sensitized solar cells: from photoanodes, sensitizers and electrolytes to counter electrodes

    Directory of Open Access Journals (Sweden)

    Meidan Ye

    2015-04-01

    Full Text Available Dye-sensitized solar cells (DSSCs, as low-cost photovoltaic devices compared to conventional silicon solar cells, have received widespread attention in recent years; although much work is required to reach optimal device efficiencies. This review highlights recent developments in DSSCs and their key components, including the photoanode, sensitizer, electrolyte and counter electrode.

  15. Characteristics of thermally reduced graphene oxide and applied for dye-sensitized solar cell counter electrode

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Ching-Yuan, E-mail: cyho@cycu.edu.tw [Department of Mechanical Engineering, Chung Yuan Christian University, Chung-Li, Taiwan (China); Department of Chemistry, Center for Nanotechnology and Institute of Biomedical Technology, Chung Yuan Christian University, Chung-Li, Taiwan (China); Wang, Hong-Wen [Department of Chemistry, Center for Nanotechnology and Institute of Biomedical Technology, Chung Yuan Christian University, Chung-Li, Taiwan (China); Department of Chemistry, Chung Yuan Christian University, Chung-Li, Taiwan (China)

    2015-12-01

    Graphical abstract: Experimental process: (1) graphite oxidized to graphene oxide; (2) thermal reduction from graphene oxide to graphene; (3) applying to DSSC counter electrode. - Highlights: • Intercalated defects were eliminated by increasing reduction temperature of GO. • High reduction temperature of tGP has lower resistance, high the electron lifetime. • Higher thermal reduction of GO proposes electrocatalytic properties. • DSSC using tGP{sub 250} as counter electrode has energy conversion efficiency of 3.4%. - Abstract: Graphene oxide (GO) was synthesized from a flake-type of graphite powder, which was then reduced to a few layers of graphene sheets using the thermal reduction method. The surface morphology, phase crystallization, and defect states of the reduced graphene were determined from an electron microscope equipped with an energy dispersion spectrometer, X-ray diffraction, Raman spectroscopy, and infrared spectra. After graphene formation, the intercalated defects that existed in the GO were removed, and it became crystalline by observing impurity changes and d-spacing. Dye-sensitized solar cells, using reduced graphene as the counter electrode, were fabricated to evaluate the electrolyte activity and charge transport performance. The electrochemical impedance spectra showed that increasing the thermal reduction temperature could achieve faster electron transport and longer electron lifetime, and result in an energy conversion efficiency of approximately 3.4%. Compared to the Pt counter electrode, the low cost of the thermal reduction method suggests that graphene will enjoy a wide range of potential applications in the field of electronic devices.

  16. Dye-sensitized solar cells based on porous conjugated polymer counter electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Torabi, Naeimeh; Behjat, Abbas, E-mail: abehjat@yazd.ac.ir; Jafari, Fatemeh

    2014-12-31

    In this paper, we report platinum-free dye-sensitized solar cells that were fabricated using a grown porous poly-3-methyl-thiophene (P3MT) counter electrode. The growing of the porous P3MT was performed by an electrochemical deposition method. This method is easy and affordable unlike the common expensive deposition methods. The morphology of P3MT films was studied by scanning electron microscopy images. It was observed that polymer layers grown with a current density of 2 mA/cm{sup 2} have a clear porous and rough structure as compared to layers grown with a lower current density. To understand the reaction kinetics and the catalytic activities of the counter electrodes with P3MT for 3I{sup −}/I{sub 3}{sup −} redox reaction, cyclic voltammetry (CV) was performed. Based on the analysis of CV, it was shown that this layer can be used as a counter electrode for dye-sensitized solar cells. The electro deposition conditions during the growth of polymer layers such as current density, the morphology of polymer films and the duration of polymerization have a significant role in the current–voltage characterization of the fabricated solar cells. The performance of the fabricated solar cells was improved by optimization of these parameters. The highest efficiency of 2.76% was obtained by using porous P3MT in the counter electrode. - Highlights: • Poly-3-methyl-thiophene (P3MT) layers were grown using electrochemical deposition method. • By controlling the growth conditions, porous P3MT can be produced. • Grown P3MT layers can be used as counter electrodes in dye-sensitized solar cells. • The growth rate of P3MT layers plays an essential role in the cell performance.

  17. Active counter electrode in a-SiC electrochemical metallization memory

    Science.gov (United States)

    Morgan, K. A.; Fan, J.; Huang, R.; Zhong, L.; Gowers, R.; Ou, J. Y.; Jiang, L.; De Groot, C. H.

    2017-08-01

    Cu/amorphous-SiC (a-SiC) electrochemical metallization memory cells have been fabricated with two different counter electrode (CE) materials, W and Au, in order to investigate the role of CEs in a non-oxide semiconductor switching matrix. In a positive bipolar regime with Cu filaments forming and rupturing, the CE influences the OFF state resistance and minimum current compliance. Nevertheless, a similarity in SET kinetics is seen for both CEs, which differs from previously published SiO2 memories, confirming that CE effects are dependent on the switching layer material or type. Both a-SiC memories are able to switch in the negative bipolar regime, indicating Au and W filaments. This confirms that CEs can play an active role in a non-oxide semiconducting switching matrix, such as a-SiC. By comparing both Au and W CEs, this work shows that W is superior in terms of a higher R OFF/R ON ratio, along with the ability to switch at lower current compliances making it a favourable material for future low energy applications. With its CMOS compatibility, a-SiC/W is an excellent choice for future resistive memory applications.

  18. Hierarchical Porous Carbon Counter Electrode for Dye-Sensitized Solar Cells

    Institute of Scientific and Technical Information of China (English)

    WANG Gui-Qiang; HUANG Cong-Gong; XING Wei; ZHUO Shu-Ping

    2011-01-01

    Hierarchical porous carbon is prepared by a combination of self-organization and chemical activation and explored as counter electrode for dye-sensitized solar cells.Pore structure analysis shows that micropores generated within the mesopore wall and the pristine mesopore structure of mesoporous carbon are preserved during KOH activation. Electrochemical impedance spectroscopy studies demonstrate a relatively high electrocatalytic activity of hierarchical porous carbon electrode for triiodide reduction, as compared with a pristine mesoporous carbon electrode. This enhanced electrocatalytic activity is beneficial for improving the photovoltaic performance of dyesensitized solar cells. The overall conversion efficiency of dye-sensitized solar cells with the hierarchical porous carbon electrode increased by 11.5% compared with that of the cell with a pristine mesoporous carbon electrode.

  19. Development of Graphene Nano-Platelet Based Counter Electrodes for Solar Cells

    Directory of Open Access Journals (Sweden)

    Iftikhar Ahmad

    2015-09-01

    Full Text Available Graphene has been envisaged as a highly promising material for various field emission devices, supercapacitors, photocatalysts, sensors, electroanalytical systems, fuel cells and photovoltaics. The main goal of our work is to develop new Pt and transparent conductive oxide (TCO free graphene based counter electrodes (CEs for dye sensitized solar cells (DSSCs. We have prepared new composites which are based on graphene nano-platelets (GNPs and conductive polymers such as poly (3,4-ethylenedioxythiophene poly(styrenesulfonate (PEDOT:PSS. Films of these composites were deposited on non-conductive pristine glass substrates and used as CEs for DSSCs which were fabricated by the “open cell” approach. The electrical conductivity studies have clearly demonstrated that the addition of GNPs into PEDOT:PSS films resulted in a significant increase of the electrical conductivity of the composites. The highest solar energy conversion efficiency was achieved for CEs comprising of GNPs with the highest conductivity (190 S/cm and n-Methyl-2-pyrrolidone (NMP treated PEDOT:PSS in a composite film. The performance of this cell (4.29% efficiency compares very favorably to a DSSC with a standard commercially available Pt and TCO based CE (4.72% efficiency in the same type of open DSSC and is a promising replacement material for the conventional Pt and TCO based CE in DSSCs.

  20. Dual functional reduced graphene oxide as photoanode and counter electrode in dye-sensitized solar cells and its exceptional efficiency enhancement

    Science.gov (United States)

    Jumeri, F. A.; Lim, H. N.; Zainal, Z.; Huang, N. M.; Pandikumar, A.; Lim, S. P.

    2015-10-01

    The dual functionalities of reduced graphene oxide (rGO) as photoanode and counter electrode in dye-sensitized solar cells (DSSCs) is explored. A titanium dioxide (TiO2) film is deposited on an indium tin oxide (ITO) glass using an in-house aerosol-assisted chemical vapor deposition method. Graphene oxide (GO) is then introduced onto the TiO2-ITO substrate, and the GO layer is successively thermally treated to rGO. The TiO2-rGO film is used as a compact layer for the photoanode of the DSSC. A layer of zinc oxide-silver (ZnO-Ag) is introduced on top of the compact layer as an active material. Its highly porous flower-shaped morphology is advantageous for the adsorption of dye. The in-situ electrochemical polymerization method used for the fabrication of polypyrrole incorporated with rGO and p-toluenesulfonate (pTS) (Ppy-rGO-pTS) on an ITO glass is used as a counter electrode for the DSSC. The DSSC assembled with the Ppy-rGO-1.0pTS counter electrode exhibites an enhanced conversion efficiency of 1.99% under solar illumination, which is better than that using conventional Pt as a counter electrode (0.08%). This is attributed to the increased contact area between the Ppy-rGO-pTS counter electrode and electrolyte, which subsequently improves the conductivity and high electrocatalytic activities of the Ppy-rGO-pTS counter electrode.

  1. Nickel doped cobalt sulfide as a high performance counter electrode for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hee-Je; Kim, Chul-Woo; Punnoose, Dinah; Gopi, Chandu V.V.M.; Kim, Soo-Kyoung; Prabakar, K.; Rao, S. Srinivasa, E-mail: srinu.krs@gmail.com

    2015-02-15

    Graphical abstract: - Highlights: • First ever employment of Ni doped CoS{sub 2} counter electrode as a replacement of Pt counter electrode. • Efficiency of 5.50% was achieved using Ni doped CoS{sub 2} counter electrode in contrast to 5.21% efficiency obtained using Pt electrode. • Dependency of efficiency on Ni dopant reported for the first time. • Cost effective chemical bath deposition was used for the fabrication of the counter electrode. - Abstract: The use of cells based on cobalt sulfide (CoS{sub 2}) and nickel sulfide (NiS) has found a steep upsurge in solar cell applications and as a substitute for conventional Pt-based cells owing to their low cost, low-temperature processing ability, and promising electro-catalytic activity. In this study, CoS{sub 2}, NiS and Ni-doped CoS{sub 2} nanoparticles were incorporated on a fluorine-doped tin oxide (FTO) substrate by simple chemical bath deposition (CBD). The surface morphology of the obtained films was analyzed by scanning electron microscope. Tafel polarization, electrochemical impedance spectroscopy and cyclic voltammograms of the Ni-doped CoS{sub 2} (Ni 15%) films indicated enhanced electro-catalytic activity for I{sub 3}{sup −} reduction in dye sensitized solar cells (DSSCs) compared to a Pt CE. The Ni-doped CoS{sub 2} CE also showed an impressive photovoltaic conversion efficiency of 5.50% under full sunlight illumination (100 mW cm{sup −2}, AM 1.5 G), exceeding that of DSSCs using a Pt CE (5.21%). We show that the highest conversion efficiency mainly depends on the charge transfer resistance and adequate Ni ion doping with CoS{sub 2} nanoparticles.

  2. Electrochemically Deposited Polypyrrole for Dye-Sensitized Solar Cell Counter Electrodes

    Directory of Open Access Journals (Sweden)

    Khamsone Keothongkham

    2012-01-01

    Full Text Available Polypyrrole films were coated on conductive glass by electrochemical deposition (alternative current or direct current process. They were then used as the dye-sensitized solar cell counter electrodes. Scanning electron microscopy revealed that polypyrrole forms a nanoparticle-like structure on the conductive glass. The amount of deposited polypyrrole (or film thickness increased with the deposition duration, and the performance of polypyrrole based-dye-sensitized solar cells is dependant upon polymer thickness. The highest efficiency of alternative current and direct current polypyrrole based-dye-sensitized solar cells (DSSCs is 4.72% and 4.02%, respectively. Electrochemical impedance spectroscopy suggests that the superior performance of alternative current polypyrrole solar cells is due to their lower charge-transfer resistance between counter electrode and electrolyte. The large charge-transfer resistance of direct current solar cells is attributed to the formation of unbounded polypyrrole chains minimizing the I3 − reduction rate.

  3. Improved electrode material for deep brain stimulation.

    Science.gov (United States)

    Petrossians, A; Whalen, J J; Weiland, J D

    2016-08-01

    Deep brain stimulation (DBS) devices have been implanted for treatment of basic tremor, Parkinson's disease and dystonia. These devices use electrodes in contact with tissue to deliver electrical pulses to targeted cells, to elicit specific therapeutic responses. In general, the neuromodulation industry has been evolving towards smaller, less invasive electrodes. However, current electrode materials do not support small sizes without severely restricting the stimulus output. Hence, an improved electrode material will benefit present and future DBS systems. In this study, five DBS leads were modified using a cost-effective and materials-efficient process for applying an ultra-low impedance platinum-iridium alloy coating. One DBS lead was used for insertion test and four DBS leads were chronically pulsed for 12 weeks. The platinum-iridium alloy significantly improved the electrical properties of the DBS electrodes and was robust to insertion into brain and to 12 weeks of chronic pulsing.

  4. Transparent metal selenide alloy counter electrodes for high-efficiency bifacial dye-sensitized solar cells.

    Science.gov (United States)

    Duan, Yanyan; Tang, Qunwei; Liu, Juan; He, Benlin; Yu, Liangmin

    2014-12-22

    The exploration of cost-effective and transparent counter electrodes (CEs) is a persistent objective in the development of bifacial dye-sensitized solar cells (DSSCs). Transparent counter electrodes based on binary-alloy metal selenides (M-Se; M=Co, Ni, Cu, Fe, Ru) are now obtained by a mild, solution-based method and employed in efficient bifacial DSSCs. Owing to superior charge-transfer ability for the I(-) /I3 (-) redox couple, electrocatalytic activity toward I3 (-) reduction, and optical transparency, the bifacial DSSCs with CEs consisting of a metal selenide alloy yield front and rear efficiencies of 8.30 % and 4.63 % for Co0.85 Se, 7.85 % and 4.37 % for Ni0.85 Se, 6.43 % and 4.24 % for Cu0.50 Se, 7.64 % and 5.05 % for FeSe, and 9.22 % and 5.90 % for Ru0.33 Se in comparison with 6.18 % and 3.56 % for a cell with an electrode based on pristine platinum, respectively. Moreover, fast activity onset, high multiple start/stop capability, and relatively good stability demonstrate that these new electrodes should find applications in solar panels. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Metal Selenides as Efficient Counter Electrodes for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Jin, Zhitong; Zhang, Meirong; Wang, Min; Feng, Chuanqi; Wang, Zhong-Sheng

    2017-04-18

    Solar energy is the most abundant renewable energy available to the earth and can meet the energy needs of humankind, but efficient conversion of solar energy to electricity is an urgent issue of scientific research. As the third-generation photovoltaic technology, dye-sensitized solar cells (DSSCs) have gained great attention since the landmark efficiency of ∼7% reported by O'Regan and Grätzel. The most attractive features of DSSCs include low cost, simple manufacturing processes, medium-purity materials, and theoretically high power conversion efficiencies. As one of the key materials in DSSCs, the counter electrode (CE) plays a crucial role in completing the electric circuit by catalyzing the reduction of the oxidized state to the reduced state for a redox couple (e.g., I3(-)/I(-)) in the electrolyte at the CE-electrolyte interface. To lower the cost caused by the typically used Pt CE, which restricts the large-scale application because of its low reserves and high price, great effort has been made to develop new CE materials alternative to Pt. A lot of Pt-free electrocatalysts, such as carbon materials, inorganic compounds, conductive polymers, and their composites with good electrocatalytic activity, have been applied as CEs in DSSCs in the past years. Metal selenides have been widely used as electrocatalysts for the oxygen reduction reaction and light-harvesting materials for solar cells. Our group first expanded their applications to the DSSC field by using in situ-grown Co0.85Se nanosheet and Ni0.85Se nanoparticle films as CEs. This finding has inspired extensive studies on developing new metal selenides in order to seek more efficient CE materials for low-cost DSSCs, and a lot of meaningful results have been achieved in the past years. In this Account, we summarize recent advances in binary and mutinary metal selenides applied as CEs in DSSCs. The synthetic methods for metal selenides with various morphologies and stoichiometric ratios and deposition

  6. Advanced Materials for Neural Surface Electrodes.

    Science.gov (United States)

    Schendel, Amelia A; Eliceiri, Kevin W; Williams, Justin C

    2014-12-01

    Designing electrodes for neural interfacing applications requires deep consideration of a multitude of materials factors. These factors include, but are not limited to, the stiffness, biocompatibility, biostability, dielectric, and conductivity properties of the materials involved. The combination of materials properties chosen not only determines the ability of the device to perform its intended function, but also the extent to which the body reacts to the presence of the device after implantation. Advances in the field of materials science continue to yield new and improved materials with properties well-suited for neural applications. Although many of these materials have been well-established for non-biological applications, their use in medical devices is still relatively novel. The intention of this review is to outline new material advances for neural electrode arrays, in particular those that interface with the surface of the nervous tissue, as well as to propose future directions for neural surface electrode development.

  7. Transparent nickel selenide used as counter electrode in high efficient dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Jinbiao; Wu, Jihuai, E-mail: jhwu@hqu.edu.cn; Tu, Yongguang; Huo, Jinghao; Zheng, Min; Lin, Jianming

    2015-08-15

    Highlights: • A transparent Ni{sub 0.85}Se is prepared by a facile solvothermal reaction. • Ni{sub 0.85}Se electrode has better electrocatalytic activity than Pt electrode. • DSSC with Ni{sub 0.85}Se electrode obtains efficiency of 8.88%, higher than DSSC with Pt. • DSSC with Ni{sub 0.85}Se/mirror electrode achieves an efficiency of 10.19%. - Abstract: A transparent nickel selenide (Ni{sub 0.85}Se) is prepared by a facile solvothermal reaction and used as an efficient Pt-free counter electrode (CE) for dye-sensitized solar cells (DSSCs). Field emission scanning electron microscopy observes that the as-prepared Ni{sub 0.85}Se possesses porous structure. Cyclic voltammogram measurement indicates that Ni{sub 0.85}Se electrode has larger current density than Pt electrode. Electrochemical impedance spectroscopy shows that the Ni{sub 0.85}Se electrode has lower charge-transfer resistance than Pt electrode. Under simulated solar light irradiation with intensity of 100 mW cm{sup −2} (AM 1.5), the DSSC based on the Ni{sub 0.85}Se CE achieves a power conversion efficiency (PCE) of 8.88%, which is higher than the solar cell based on Pt CE (8.13%). Based on the transparency of Ni{sub 0.85}Se, the DSSC with Ni{sub 0.85}Se/mirror achieves a PCE of 10.19%.

  8. Ordered mesoporous tungsten suboxide counter electrode for highly efficient iodine-free electrolyte-based dye-sensitized solar cells.

    Science.gov (United States)

    Jeong, Inyoung; Jo, Changshin; Anthonysamy, Arockiam; Kim, Jung-Min; Kang, Eunae; Hwang, Jongkook; Ramasamy, Easwaramoorthi; Rhee, Shi-Woo; Kim, Jin Kon; Ha, Kyoung-Su; Jun, Ki-Won; Lee, Jinwoo

    2013-02-01

    A disulfide/thiolate (T(2)/T(-)) redox-couple electrolyte, which is a promising iodine-free electrolyte owing to its transparent and noncorrosive properties, requires alternative counter-electrode materials because conventional Pt shows poor catalytic activity in such an electrolyte. Herein, ordered mesoporous tungsten suboxide (m-WO(3-x)), synthesized by using KIT-6 silica as a hard template followed by a partial reduction, is used as a catalyst for a counter electrode in T(2)/T(-)-electrolyte-based dye-sensitized solar cells (DSCs). The mesoporous tungsten suboxide, which possesses interconnected pores of 4 and 20 nm, provides a large surface area and efficient electrolyte penetration into the m-WO(3-x) pores. In addition to the advantages conferred by the mesoporous structure, partial reduction of tungsten oxide creates oxygen vacancies that can function as active catalytic sites, which causes a high electrical conductivity because of intervalence charge transfer between the W(5+) and W(6+) ions. m-WO(3-x) shows a superior photovoltaic performance (79 % improvement in the power conversion efficiency) over Pt in the T(2)/T(-) electrolyte. The superior catalytic activity of m-WO(3-x) is investigated by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel polarization curve analysis.

  9. Pt-Free Counter Electrodes with Carbon Black and 3D Network Epoxy Polymer Composites

    Science.gov (United States)

    Kang, Gyeongho; Choi, Jongmin; Park, Taiho

    2016-03-01

    Carbon black (CB) and a 3D network epoxy polymer composite, representing dual functions for conductive corrosion protective layer (CCPL) and catalytic layer (CL) by the control of CB weight ratio against polymer is developed. Our strategy provides a proper approach which applies high catalytic ability and chemical stability of CB in corrosive triiodide/iodide (I3-/I-) redox electrolyte system. The CB and a 3D network epoxy polymer composite coated on the stainless steel (SS) electrode to alternate counter electrodes in dye sensitized solar cells (DSSCs). A two-step spray pyrolysis process is used to apply a solution containing epoxy monomers and a polyfunctional amine hardener with 6 wt% CB to a SS substrate, which forms a CCPL. Subsequently, an 86 wt% CB is applied to form a CL. The excellent catalytic properties and corrosion protective properties of the CB and 3D network epoxy polymer composites produce efficient counter electrodes that can replace fluorine-doped tin oxide (FTO) with CCPL/SS and Pt/FTO with CL/CCPL/SS in DSSCs. This approach provides a promising approach to the development of efficient, stable, and cheap solar cells, paving the way for large-scale commercialization.

  10. Nickel nanocrystals grown on sparse hierarchical CuS microflowers as high-performance counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Shi, Zhaoliang; Zhou, Wei; Ma, Yiran

    2016-07-01

    Three kinds of hierarchical CuS microflowers composed of thin nanosheets have been synthesized by a simple wet chemical method. It is shown that the CuS microflowers provide suitable substrates to grow nickel nanocrystals. The prepared Ni@CuS hybrids combined with conductive glass (FTO) have been used as counter electrodes for dye-sensitized solar cells (DSSCs). The electrode made of the active material of Ni@CuS microflowers with sparsest petals show an optimal photoelectric conversion efficiency of 4.89%, better than those made of single component of Ni (3.39%) or CuS (1.65%), and other two Ni@CuS composites. The improved performances could be ascribed to the synergetic effect of the catalytic effect towards I3‑/I‑ from sparse CuS hierarchical structure and uniformly grown Ni nanocrystals. Besides, the introduced Ni nanocrystals could increase the conductivity of the hybrid and facilitate the transport of electrons. The hybrid Ni@CuS composites serving as counter electrodes have much enhanced electrochemical properties, which provide a feasible route to develop high-active non-noble hybrid counter electrode materials.

  11. Metal-Free Counter Electrode for Efficient Dye-Sensitized Solar Cells through High Surface Area and Large Porous Carbon

    Directory of Open Access Journals (Sweden)

    Pavuluri Srinivasu

    2011-01-01

    Full Text Available Highly efficient, large mesoporous carbon is fabricated as a metal-free counter electrode for dye-sensitized solar cells. The mesoporous carbon shows very high energy conversion efficiency of 7.1% compared with activated carbon. The mesoporous carbon is prepared and characterized by nitrogen adsorption, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The nitrogen adsorption data reveals that the material possesses BET specific surface area ca.1300 m2/g and pore diameter 4.4 nm. Hexagonal rod-like morphology and ordered pore structure of mesoporous carbon are confirmed by electron microscopy data. The better performance of this carbon material is greatly benefited from its ordered interconnected mesoporous structure and high surface area.

  12. Ordered mesoporous carbon/graphene nano-sheets composites as counter electrodes in dye-sensitized solar cells

    Science.gov (United States)

    Shao, Leng-Leng; Chen, Ming; Ren, Tie-Zhen; Yuan, Zhong-Yong

    2015-01-01

    The composites of ordered mesoporous carbon (OMC) and graphene nano-sheets (GNS) are prepared by mixing OMC with different weight ratios of GNS, and utilized as counter electrode (CE) materials for dye-sensitized solar cells (DSSCs). Electrochemical impedance spectroscopy, Tafel polarization, and cyclic voltammetry measurements demonstrate that the OMC/GNS CEs display the enhanced electron transport property and fast reduction rate of I3- in comparison with those of the individual OMC and GNS CEs, due to the combination of superior electrical conductivity of GNS and good catalytic activity of OMC. Under AM 1.5 irradiation (100 mW cm-2), the DSSCs based on the OMC/GNS CEs show a maximum power conversion efficiency of 6.82%, which is comparable to 7.08% of the cell with the conventional Pt CE at the same experimental conditions, suggesting that the OMC/GNS composites are one of advanced CE materials for low-cost DSSCs.

  13. Sol-gel spin coated well adhered MoO3 thin films as an alternative counter electrode for dye sensitized solar cells

    Science.gov (United States)

    Mutta, Geeta R.; Popuri, Srinivasa R.; Wilson, John I. B.; Bennett, Nick S.

    2016-11-01

    In this work, we aim to develop a viable, inexpensive and non-toxic material for counter electrodes in dye sensitized solar cells (DSSCs). We employed an ultra-simple synthesis process to deposit MoO3 thin films at low temperature by sol-gel spin coating technique. These MoO3 films showed good transparency. It is predicted that there will be 150 times reduction of precursors cost by realizing MoO3 thin films as a counter electrode in DSSCs compared to commercial Pt. We achieved a device efficiency of about 20 times higher than that of the previous reported values. In summary we develop a simple low cost preparation of MoO3 films with an easily scaled up process along with good device efficiency. This work encourages the development of novel and relatively new materials and paves the way for massive reduction of industrial costs which is a prime step for commercialization of DSSCs.

  14. Sub-micrometer-sized graphite as a conducting and catalytic counter electrode for dye-sensitized solar cells.

    Science.gov (United States)

    Veerappan, Ganapathy; Bojan, Karunagaran; Rhee, Shi-Woo

    2011-03-01

    Sub-micrometer-sized colloidal graphite (CG) was tested as a conducting electrode to replace transparent conducting oxide (TCO) electrodes and as a catalytic material to replace platinum (Pt) for I(3)(-) reduction in dye-sensitized solar cell (DSSC). CG paste was used to make a film via the doctor-blade process. The 9 μm thick CG film showed a lower resistivity (7 Ω/◻) than the widely used fluorine-doped tin oxide TCO (8-15 Ω/◻). The catalytic activity of this graphite film was measured and compared with the corresponding properties of Pt. Cyclic voltammetry and electrochemical impedance spectroscopy studies clearly showed a decrease in the charge transfer resistance with the increase in the thickness of the graphite layer from 3 to 9 μm. Under 1 sun illumination (100 mW cm(-2), AM 1.5), DSSCs with submicrometer-sized graphite as a catalyst on fluorine-doped tin oxide TCO showed an energy conversion efficiency greater than 6.0%, comparable to the conversion efficiency of Pt. DSSCs with a graphite counter electrode (CE) on TCO-free bare glass showed an energy conversion efficiency greater than 5.0%, which demonstrated that the graphite layer could be used both as a conducting layer and as a catalytic layer.

  15. Pt/Mesoporous Carbon Counter Electrode with a Low Pt Loading for High-Efficient Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Guiqiang Wang

    2010-01-01

    Full Text Available Pt/Mesoporous carbon counter electrodes with a low Pt loading for dye-sensitized solar cells were fabricated by coating Pt/mesoporous carbon on fluorine-doped tin oxide glass. Pt/mesoporous carbon samples were prepared by reducing H2PtCl6 with NaBH4 in mesoporous carbon and characterized by N2 adsorption analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. The Pt particles deposited on mesoporous carbon support were found to be in uniform shape and narrow range of particle size. Low-Pt-loading Pt/mesoporous carbon counter electrode showed a high electrocatalytic activity for triiodide reduction. Electrochemical impedance spectroscopy measurement displayed a low charge-transfer resistance of 1.2 Ωcm2 for 1-Pt/mesoporous carbon counter electrode. Dye-sensitized solar cells based on the 1-Pt/mesoporous carbon counter electrode achieved an overall conversion efficiency of 6.62% under one sun illumination, which is higher than that of the cell with the conventional Pt counter electrode.

  16. Platinum-free binary Co-Ni alloy counter electrodes for efficient dye-sensitized solar cells.

    Science.gov (United States)

    Chen, Xiaoxu; Tang, Qunwei; He, Benlin; Lin, Lin; Yu, Liangmin

    2014-09-26

    Dye-sensitized solar cells (DSSCs) have attracted growing interest because of their application in renewable energy technologies in developing modern low-carbon economies. However, the commercial application of DSSCs has been hindered by the high expenses of platinum (Pt) counter electrodes (CEs). Here we use Pt-free binary Co-Ni alloys synthesized by a mild hydrothermal strategy as CE materials in efficient DSSCs. As a result of the rapid charge transfer, good electrical conduction, and reasonable electrocatalysis, the power conversion efficiencies of Co-Ni-based DSSCs are higher than those of Pt-only CEs, and the fabrication expense is markedly reduced. The DSSCs based on a CoNi0.25 alloy CE displays an impressive power conversion efficiency of 8.39%, fast start-up, multiple start/stop cycling, and good stability under extended irradiation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Enhanced photovoltaic performance of dye-sensitized solar cells by the strategy of introducing copper(II) silicotungstate into photoanode and counter electrode

    Science.gov (United States)

    Jiang, Yanxia; Yang, Yulin; Qiang, Liangsheng; Ye, Tengling; Li, Liang; Su, Ting; Fan, Ruiqing

    2016-09-01

    The device of polyoxometalate (POM) modified photoelectrodes is designed and successfully constructed. K6SiW11O39Cu(H2O)·xH2O (SiW11Cu) has been synthesized and explored as an efficient photoanode and counter electrode material to develop dye-sensitized solar cells (DSSCs) with enhanced performance. The SiW11Cu modified TiO2 (SiW11Cu/TiO2) powders is mixed with commercial P25 in a ratio of 1:9 as a photoanode. The modified TiO2 is used as an efficient material by improving the electronic injection ability and reducing the pohotogenerated charge recombination. The counter electrode is consisted of one layer SiW11Cu and two layers conventional Pt nanoparticles, denoted as (Cu/Pt). The DSSC based on SiW11Cu modified photoelectrodes has an improved power conversion efficiency of 7.62%, which is 16% higher than that of traditional DSSC based on P25-Pt. Under standard AM 1.5G, Jsc reaches 17.91 mA cm-2, which results in a much better power conversion efficiency. This can be attributed to the good catalytic activity of the new counter electrode. This result is analyzed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), Tafel-polarization curves, the incident photon to current conversion efficiency (IPCE) and UV-vis spectra techniques.

  18. Gallium Nitride Crystals: Novel Supercapacitor Electrode Materials.

    Science.gov (United States)

    Wang, Shouzhi; Zhang, Lei; Sun, Changlong; Shao, Yongliang; Wu, Yongzhong; Lv, Jiaxin; Hao, Xiaopeng

    2016-05-01

    A type of single-crystal gallium nitride mesoporous membrane is fabricated and its supercapacitor properties are demonstrated for the first time. The supercapacitors exhibit high-rate capability, stable cycling life at high rates, and ultrahigh power density. This study may expand the range of crystals as high-performance electrode materials in the field of energy storage.

  19. Palladium and platinum-palladium bi-layer based counter electrode for dye-sensitized solar cells with modified photoanode

    Science.gov (United States)

    Mokurala, Krishnaiah; Kamble, Anvita; Nemala, Siva Sankar; Bhargava, Parag; Mallick, Sudhanshu

    2015-06-01

    Dye sensitized solar cells (DSSCs) were fabricated with palladium (Pd) and platinum-palladium (Pt-Pd) bi-layer as counter electrodes, respectively. Effects of photoanode thickness and morphology on device performance were studied. DSSCs fabricated with Pd and Pd-Pt as counter electrode (CE) showed photo conversion efficiency of 4.30% and 6.20%, respectively as compared to Platinum (Pt) based CE which showed 6.65% efficiency. Lower device performance was explained with help of cyclic voltammetry and electrochemical impedance spectroscopy (EIS) measurements of the cells.

  20. Solid-state dye-sensitized solar cells using polymerized ionic liquid electrolyte with platinum-free counter electrode.

    Science.gov (United States)

    Kawano, Ryuji; Katakabe, Toru; Shimosawa, Hironobu; Nazeeruddin, Md Khaja; Grätzel, Michael; Matsui, Hiroshi; Kitamura, Takayuki; Tanabe, Nobuo; Watanabe, Masayoshi

    2010-02-28

    A polymerized ionic liquid electrolyte and platinum-free counter electrode are employed for solid-state DSSCs. We are able to prepare a thin polymer electrolyte layer on nanocrystalline TiO(2) in order to reduce the cell resistance. In addition, an electron conductive polymer (PEDOT/PSS) or a single-wall carbon nanotube gel is used with the cell as an inexpensive counter electrode instead of platinum. The overall photon-to-current conversion efficiency was 3.7% in this study.

  1. Synthesis, characterization and application of electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    He, Lin [Iowa State Univ., Ames, IA (United States)

    1995-07-07

    It has been known that significant advances in electrochemistry really depend on improvements in the sensitivity, selectivity, convenience, and/or economy of working electrodes, especially through the development of new working electrode materials. The advancement of solid state chemistry and materials science makes it possible to provide the materials which may be required as satisfactory electrode materials. The combination of solid state techniques with electrochemistry expands the applications of solid state materials and leads to the improvement of electrocatalysis. The study of Ru-Ti4O7 and Pt-Ti4O7 microelectrode arrays as introduced in paper 1 and paper 4, respectively, focuses on their synthesis and characterization. The synthesis is described by high temperature techniques for Ru or Pt microelectrode arrays within a conductive Ti4O7ceramic matrix. The characterization is based on the data obtained by x-ray diffractometry, scanning electron microscopy, voltammetry and amperometry. These microelectrode arrays show significant enhancement in current densities in comparison to solid Ru and Pt electrodes. Electrocatalysis at pyrochlore oxide Bi2Ru2O7.3 and Bi2Ir2O7 electrodes are described in paper 2 and paper 3, respectively. Details are reported for the synthesis and characterization of composite Bi2Ru2O7.3 electrodes. Voltammetric data are examined for evidence that oxidation can occur with transfer of oxygen to the oxidation products in the potential region corresponding to anodic discharge of H2O with simultaneous evolution of O2. Paper 3 includes electrocatalytic activities of composite Bi2Ir2O7 disk electrodes for the oxidation of I- and the reduction of IO3-.

  2. Transparent nickel selenide alloy counter electrodes for bifacial dye-sensitized solar cells exceeding 10% efficiency.

    Science.gov (United States)

    Duan, Yanyan; Tang, Qunwei; He, Benlin; Li, Ru; Yu, Liangmin

    2014-11-07

    In the current work, we report a series of bifacial dye-sensitized solar cells (DSSCs) that provide power conversion efficiencies of more than 10% from bifacial irradiation. The device comprises an N719-sensitized TiO2 anode, a transparent nickel selenide (Ni-Se) alloy counter electrode (CE), and liquid electrolyte containing I(-)/I3(-) redox couples. Because of the high optical transparency, electron conduction ability, electrocatalytic activity of Ni-Se CEs, as well as dye illumination, electron excitation and power conversion efficiency have been remarkably enhanced. Results indicate that incident light from a transparent CE has a compensation effect to the light from the anode. The impressive efficiency along with simple preparation of the cost-effective Ni-Se alloy CEs highlights the potential application of bifacial illumination technique in robust DSSCs.

  3. Multistep electrochemical deposition of hierarchical platinum alloy counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Zhang, Junjun; Ma, Mingming; Tang, Qunwei; Yu, Liangmin

    2016-01-01

    The preferred platinum counter electrode (CE) has been a burden for commercialization of dye-sensitized solar cell (DSSC) due to high expense and chemical corrosion by liquid electrolyte. In the current study, we have successfully realized the multistep deposition of platinum alloy CEs including PtNi, PtFe, and PtCo for liquid-junction DSSC applications. The preliminary results demonstrate that the enhanced electrochemical activities are attributable to high charge-transfer ability and matching work functions of the PtM (M = Ni, Fe, Co) alloy CEs to redox potential of I-/I3- electrolyte. The resultant DSSCs yield impressive power conversion efficiencies of 8.65%, 7.48%, and 7.08% with PtNi, PtFe, and PtCo CEs, respectively. On behalf of the competitive reactions between transition metals with liquid electrolyte, the PtM alloy CEs display enhanced long-term stability.

  4. Counter electrodes from binary ruthenium selenide alloys for dye-sensitized solar cells

    Science.gov (United States)

    Li, Pinjiang; Cai, Hongyuan; Tang, Qunwei; He, Benlin; Lin, Lin

    2014-12-01

    Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its merits on clean, cost-effectiveness, relatively high efficiency, and easy fabrication. However, the reduction of fabrication cost without sacrifice of power conversion efficiencies of the DSSCs is a golden rule for their commercialization. Here we design a new binary ruthenium selenide (Ru-Se) alloy counter electrodes (CEs) by a low-temperature hydrothermal reduction method. The electrochemical behaviors are evaluated by cyclic voltammogram, electrochemical impedance, and Tafel measurements, giving an optimized Ru/Se molar ratio of 1:1. The DSSC device with RuSe alloy CE achieves a power conversion efficiency of 7.15%, which is higher than 5.79% from Pt-only CE based DSSC. The new concept, easy process along with promising results provide a new approach for reducing cost but enhancing photovoltaic performances of DSSCs.

  5. Flexible, Low Cost, and Platinum-Free Counter Electrode for Efficient Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Ali, Abid; Shehzad, Khurram; Ur-Rahman, Faiz; Shah, Syed Mujtaba; Khurram, Muhammad; Mumtaz, Muhammad; Sagar, Rizwan Ur Rehman

    2016-09-28

    A platinum-free counter electrode composed of surface modified aligned multiwalled carbon nanotubes (MWCNTs) fibers was fabricated for efficient flexible dye-sensitized solar cells (DSSCs). Surface modification of MWCNTs fibers with simple one step hydrothermal deposition of cobalt selenide nanoparticles, confirmed by scanning electron microscopy and X-ray diffraction, provided a significant improvement (∼2-times) in their electrocatalytic activity. Cyclic voltammetry and electrochemical impedance spectroscopy suggest a photoelectric conversion efficiency of 6.42% for our modified fibers, higher than 3.4% and 5.6% efficeincy of pristine MWCNTs fiber and commonly used Pt wire, respectively. Good mechanical and performance stability after repeated bending and high output voltage for in-series connection suggest that our surface modified MWCNTs fiber based DSSCs may find applications as flexible power source in next-generation flexible/wearable electronics.

  6. Pt crystalline ultrathin films as counter electrodes for bifacial dye-sensitized solar cells

    Science.gov (United States)

    Cheng, Cheng-En; Lin, Zheng-Kun; Lin, Yu-Chang; Lei, Bi-Chen; Chang, Chen-Shiung; Shih-Sen Chien, Forest

    2017-01-01

    This study is to develop the Pt crystalline ultrathin films as high-transparent, efficient, and low-Pt-loaded counter electrodes (CEs) for bifacial dye-sensitized solar cells (DSCs). The 1-nm-thick Pt ultrathin films are sputtered on fluorine-doped tin oxide substrates and thermal annealed at 400 °C. After annealing, as-prepared amorphous-nanocrystal-mixed Pt films become high-crystalline films with better optical transmittance and electrocatalytic ability to I3 - reduction for bifacial DSCs. The rear-to-front ratios of short-circuit current density and power conversion efficiency of DSCs with crystalline ultrathin Pt CEs are as high as 81 and 83%, respectively.

  7. Efficient Nickel Sulfide and Graphene Counter Electrodes Decorated with Silver Nanoparticles and Application in Dye-Sensitized Solar Cells

    Science.gov (United States)

    Yue, Gentian; Li, Fumin; Yang, Guang; Zhang, Weifeng

    2016-05-01

    We reported a facile two-step electrochemical-chemical approach for in situ growth of nickel sulfide and graphene counter electrode (CE) decorated with silver nanoparticles (signed NiS/Gr-Ag) and served in dye-sensitized solar cells (DSSCs). Under optimum conditions, the DSSC achieved a remarkable power conversion efficiency of 8.36 % assembled with the NiS/Gr-Ag CE, much higher than that based on the Pt CE (7.76 %). The surface morphology of NiS/Gr-Ag CE exhibited a smooth surface with cross-growth of NiS, graphene, and Ag nanoparticles, which was beneficial to the fast mass transport of electrolytes; increased the contact area of electrolytes and active materials; and enabled to speed up the reduction of triiodide to iodide. The research on the electrochemical properties also showed that the NiS/Gr-Ag CE possessed lower charge transfer resistance and more excellent electrocatalytic activity in iodide/triiodide electrolyte compared to the Pt electrode.

  8. Mesoporous NiCo2O4 networks with enhanced performance as counter electrodes for dye-sensitized solar cells.

    Science.gov (United States)

    Zhang, Chenle; Deng, Libo; Zhang, Peixin; Ren, Xiangzhong; Li, Yongliang; He, Tingshu

    2017-03-27

    The performance of a dye-sensitized solar cell (DSSC) is strongly influenced by the catalytic performance of its counter electrode (CE) materials. Platinum (Pt) is conventionally used as the CE for DSSCs, but it is precious and is readily corroded by the iodide/triiodide electrolyte. Herein, mesoporous NiCo2O4 networks with different types of building blocks were prepared by electrospinning of a composite solution followed by annealing in air, and their performances as CEs in DSSCs were investigated. The honeycomb-like NiCo2O4 exhibited better performance than the nanotube ones, showing a photoelectric conversion efficiency of 7.09% which is higher than that of a standard Pt CE (7.05%) under the same conditions. The enhanced electrode performance was attributed to the relatively larger surface area and higher conductivity. The preparation methods demonstrated in this study are scalable and would pave the way for practical applications of Pt-free DSSCs.

  9. Nanopatterned conductive polymer films as a Pt, TCO-free counter electrode for low-cost dye-sensitized solar cells.

    Science.gov (United States)

    Kwon, Jeong; Ganapathy, Veerappan; Kim, Young Hun; Song, Kyung-Deok; Park, Hong-Gyu; Jun, Yongseok; Yoo, Pil J; Park, Jong Hyeok

    2013-09-07

    A low-cost nanopatterned highly conductive poly(3,4-ethylenedioxythiophene) (PEDOT) thin film was fabricated on a flexible plastic substrate via a chemical polymerization method combined with a nanoimprinting technique and used as a platinum (Pt), TCO-free counter electrode for dye-sensitized solar cells (DSSCs). The catalytic properties of the nanopatterned PEDOT as the counter electrode in DSSCs were studied using cyclic voltammetry, J-V measurements, impedance spectroscopy, and finite-difference time-domain (FDTD) simulations. The nanopatterned PEDOT counter electrodes exhibit better functionality as a counter electrode for tri-iodide reduction when compared to non-patterned PEDOT-based counter electrodes. The Pt and TCO-free DSSCs with a nanopatterned PEDOT-based counter electrode exhibited a power conversion efficiency of 7.1% under one sunlight illumination (100 mW cm(-2)), which is comparable to that of conventional DSSCs with standard platinum Pt/FTO paired counter electrodes. The ability to modulate catalytic functionality with changes in nanoscale morphology represents a promising route for developing new counter electrodes of Pt and TCO-free DSSCs.

  10. High efficiency organic-electrolyte DSSC based on hydrothermally deposited titanium carbide-carbon counter electrodes

    Science.gov (United States)

    Towannang, Madsakorn; Kumlangwan, Pantiwa; Maiaugree, Wasan; Ratchaphonsaenwong, Kunthaya; Harnchana, Viyada; Jarenboon, Wirat; Pimanpang, Samuk; Amornkitbamrung, Vittaya

    2015-07-01

    Pt-free TiC based electrodes were hydrothermally deposited onto FTO/glass substrates and used as dye-sensitized solar cell (DSSC) counter electrodes. A promising efficiency of 3.07% was obtained from the annealed hydrothermal TiC DSSCs based on a disulfide/thiolate electrolyte. A pronounced improvement in performance of 3.59% was achieved by compositing TiC with carbon, compared to that of a Pt DSSC, 3.84%. TEM analysis detected that the TiC particle surfaces were coated by thin carbon layer (7 nm). The SAED pattern and Raman spectrum of TiC-carbon films suggested that the carbon layer was composed of amorphous and graphite carbon. The formation of graphite on the TiC nanoparticles plays a crucial role in enhancing the film's reduction current to 10.12 mA/cm2 and in reducing the film impedance to 237.63 Ω, resulting in a high efficiency of the TiC-carbon DSSC. [Figure not available: see fulltext.

  11. Synthesis and characterization of DSSC by using Pt nano-counter electrode: photosensor applications

    Science.gov (United States)

    Yahia, I. S.; AlFaify, S.; Al-ghamdi, Attieh A.; Hafez, Hoda S.; EL-Bashir, S.; Al-Bassam, A.; El-Naggar, A. M.; Yakuphanoglu, F.

    2016-06-01

    Pt electrode prepared by chemical method has been employed as counter electrode in dye-sensitized solar cell. TiO2 nanomaterial was deposited on fluorine-doped tin oxide substrate to be used as photoanode. Structure of the TiO2 and Pt films was investigated by atomic force microscope. The effect of illumination intensity on the photovoltaic parameters such as open circuit voltage, short circuit current density, output power, fill factor and efficiency of these cells was investigated in the range 2.5-130 mW/cm-2. The cell efficiency is stable above 70 mW/cm2. The fill factor is almost constant all over the studied range of illumination intensity. Impedance spectroscopy of the studied device as the summary measurements of the capacitance-voltage, conductance-voltage and series resistance-voltage characteristics were investigated in a wide range of frequencies (5 kHz-1 MHz). At low frequencies, the capacitance has positive values with peak around the origin due to the interfaces. At 200 and 300 kHz, the capacitance is inverted to negative with further increasing of the positive biasing voltage. Above 400 kHz, C-V profile shows complete negative behavior. Also, the impedance-voltage and phase-voltage characteristics were investigated. This cell shows a new promising device for photosensor applications due to high sensitivity in low and high illuminations.

  12. Vanadium based materials as electrode materials for high performance supercapacitors

    Science.gov (United States)

    Yan, Yan; Li, Bing; Guo, Wei; Pang, Huan; Xue, Huaiguo

    2016-10-01

    As a kind of supercapacitors, pseudocapacitors have attracted wide attention in recent years. The capacitance of the electrochemical capacitors based on pseudocapacitance arises mainly from redox reactions between electrolytes and active materials. These materials usually have several oxidation states for oxidation and reduction. Many research teams have focused on the development of an alternative material for electrochemical capacitors. Many transition metal oxides have been shown to be suitable as electrode materials of electrochemical capacitors. Among them, vanadium based materials are being developed for this purpose. Vanadium based materials are known as one of the best active materials for high power/energy density electrochemical capacitors due to its outstanding specific capacitance and long cycle life, high conductivity and good electrochemical reversibility. There are different kinds of synthetic methods such as sol-gel hydrothermal/solvothermal method, template method, electrospinning method, atomic layer deposition, and electrodeposition method that have been successfully applied to prepare vanadium based electrode materials. In our review, we give an overall summary and evaluation of the recent progress in the research of vanadium based materials for electrochemical capacitors that include synthesis methods, the electrochemical performances of the electrode materials and the devices.

  13. Reference and counter electrode positions affect electrochemical characterization of bioanodes in different bioelectrochemical systems

    KAUST Repository

    Zhang, Fang

    2014-06-16

    The placement of the reference electrode (RE) in various bioelectrochemical systems is often varied to accommodate different reactor configurations. While the effect of the RE placement is well understood from a strictly electrochemistry perspective, there are impacts on exoelectrogenic biofilms in engineered systems that have not been adequately addressed. Varying distances between the working electrode (WE) and the RE, or the RE and the counter electrode (CE) in microbial fuel cells (MFCs) can alter bioanode characteristics. With well-spaced anode and cathode distances in an MFC, increasing the distance between the RE and anode (WE) altered bioanode cyclic voltammograms (CVs) due to the uncompensated ohmic drop. Electrochemical impedance spectra (EIS) also changed with RE distances, resulting in a calculated increase in anode resistance that varied between 17 and 31Ω (-0.2V). While WE potentials could be corrected with ohmic drop compensation during the CV tests, they could not be automatically corrected by the potentiostat in the EIS tests. The electrochemical characteristics of bioanodes were altered by their acclimation to different anode potentials that resulted from varying the distance between the RE and the CE (cathode). These differences were true changes in biofilm characteristics because the CVs were electrochemically independent of conditions resulting from changing CE to RE distances. Placing the RE outside of the current path enabled accurate bioanode characterization using CVs and EIS due to negligible ohmic resistances (0.4Ω). It is therefore concluded for bioelectrochemical systems that when possible, the RE should be placed outside the current path and near the WE, as this will result in more accurate representation of bioanode characteristics. © 2014 Wiley Periodicals, Inc.

  14. Flexible and conductive cotton fabric counter electrode coated with graphene nanosheets for high efficiency dye sensitized solar cell

    Science.gov (United States)

    Sahito, Iftikhar Ali; Sun, Kyung Chul; Arbab, Alvira Ayoub; Qadir, Muhammad Bilal; Choi, Yun Seon; Jeong, Sung Hoon

    2016-07-01

    Textile fabric based electrodes due to their lightweight, flexibility and cost effectiveness, coupled with the ease of fabrication are recently given a huge attention as wearable energy sources. The current dye sensitized solar cells (DSSCs) are based on Platinized-Fluorinated Tin oxide (Pt-FTO) glass electrode, which is not only expensive, but also rigid and heavyweight. In this work, a highly conductive-graphene coated cotton fabric (HC-GCF) is fabricated with a surface resistance of only 7 Ω sq-1. HC-GCF is used as an efficient counter electrode (CE) in DSSC and the results are examined using photovoltaic and electrochemical analysis. HC-GCF counter electrode shows a negligible change of resistance to bending at various bending positions and is also found extremely resistant to electrolyte solution and washing with water. Cyclic voltammogram, Nyquist and the Tafel plots suggest an excellent electro catalytic activity (ECA) for the reduction of tri-iodide (I3-) ions. Symmetrical cells prepared using HC-GCF, indicate a very low charge transfer resistance (RCT) of only 1.2 Ω, which is nearly same to that of the Pt with 1.04 Ω. Furthermore, a high photovoltaic conversion efficiency (PCE) of 6.93% is achieved using HC-GCF counter electrode using polymer electrolyte.

  15. Spray deposited CeO2–TiO2 counter electrode for electrochromic devices

    Indian Academy of Sciences (India)

    A K Bhosale; S R Kulal; V M Gurame; P S Patil

    2015-04-01

    Optically passive thin films of CeO2–TiO2 mixed oxides with molar ratio of Ce/Ti of 0.05 were deposited by the spray pyrolysis technique (SPT) on a glass and fluorine-doped tin oxide (FTO)-coated glass substrates. Precursor solution containing cerium nitrate hexahydrate (Ce(NO3)2·6H2O) and titanium tetraiso-propoxide (Ti(OiPr)4) having different volumetric proportions (0–5 vol% of Ti) in methanol were used. These films were characterized for structural, morphological, molecular, optical, electrochromic and colourimetric analysis. CeO2–TiO2 films deposited at 400° C were found to be polycrystalline with cubic fluorite crystal structure. Transformation from polycrystalline to amorphous phase was observed with increasing TiO2 content. The band centred at 539 cm−1 is assigned to Ce–O stretching vibration and the two medium intensity bands assigned to (Ti–O) and (Ti–O–Ti) stretching modes at 798 and 451 cm−1, which confirms the mixed CeO2 and TiO2 phases. The band gap energy decreases (g) from 3.45 eV for pristine CeO2 to 2.98–3.09 eV for CeO2–TiO2 films. The ion storage capacity (ISC) of CeO2–TiO2 thin film with 3 vol% Ti (Ce–Ti3 sample) was found to be 26 mC cm−2 and electrochemical stability up to 30,000 cycles in 0.5 M LiClO4-PC electrolyte. The optically passive behaviour of CeO2–TiO2 thin film is confirmed by its negligible transmission modulation ( ∼ 2.5%) upon Li+ ion insertion/extraction, irrespective of the extent of Li+ ion intercalation. The optical modulation of sputter deposited electrochromic WO3 thin film was found to be enhanced from 56 to 61% with rapid increase in colouration efficiency (CE) from 42 to 231 cm2 C−1 when CeO2–TiO2 is coupled as a counter electrode with WO3 in an electrochromic device (ECD). On reduction of WO3 thin film with CeO2–TiO2 as counter electrode, the CIELAB 1931 2° colour space coordinates show the transition from colourless to the deep blue state (* = 88.07, * = −2.37, * = 24.59 and

  16. Improving Electrode Durability of PEF Chamber by selecting suitable material

    Science.gov (United States)

    Corrosion resistance of four materials - titanium, platinized titanium, stainless steel, and boron carbide - as electrodes in a Pulsed Electric Field (PEF) system was studied to reduce electrode material migration into the food by electrode corrosion. The PEF process conditions were 28 kV/cm field s...

  17. Highly efficient dye-sensitized solar cell with GNS/MWCNT/PANI as a counter electrode

    Energy Technology Data Exchange (ETDEWEB)

    Al-bahrani, Majid Raissan [Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology - HUST, Luoyu Road 1037, Wuhan 430074 (China); Faculty of Science, Thi-Qar University, Nassiriya (Iraq); Xu, Xiaobao [Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, 1037 Luoyu Road, 430074 Wuhan (China); Ahmad, Waqar; Ren, Xiaoliang; Su, Jun [Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology - HUST, Luoyu Road 1037, Wuhan 430074 (China); Cheng, Ze [School of Physics, Huazhong University of Science and Technology (HUST), Luoyu Road 1037, Wuhan 430074 (China); Gao, Yihua, E-mail: gaoyihua@hust.edu.cn [Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology - HUST, Luoyu Road 1037, Wuhan 430074 (China)

    2014-11-15

    Highlights: • High-performance PANI/MWCNT-CE was incorporated in a Pt-CE in DSSCs. • GNS/MWCNT/PANI-CE exhibits a high power conversion efficiency (PCE) of 7.52%. • GNS/MWCNT/PANI composite has a high catalytic activity for the reduction of I{sub 3}{sup −}. • GNS/MWCNT/PANI composite has a low R{sub CT} on the electrolyte/CE interface. - Abstract: A graphene-based nanosheet composite/multiwalled carbon nanotube/polyaniline (GNS/MWCNT/PANI) was synthesized via an in situ polymerization technique and applied by the spin-coating method as a counter electrode (CE) in dye-sensitized solar cells (DSSCs). The combination of the high catalytic activity of PANI and outstanding conductivity of GNS/MWCNT improved the photovoltaic performance of the hybrid CE. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) showed that the GNS/MWCNT/PANI composite has high catalytic activity for the reduction of triiodide to iodide and low charge-transfer resistance at the electrolyte/electrode interface. Transmission electron microscopy (TEM) images showed that the GNS/MWCNT/PANI-CE has a rough and porous structure and X-ray diffraction analysis confirmed the formation of PANI coating on the surface of the GNS/CNT. In particular, current–voltage measurements showed the superior power conversion efficiency (PCE) of 7.52% of the DSSC based on GNS/MWCNT/PANI-CE compared to the PCE of 6.69% of the DSSC based on Pt-CE.

  18. Platinum/Palladium hollow nanofibers as high-efficiency counter electrodes for enhanced charge transfer

    Science.gov (United States)

    Navarro Pardo, F.; Benetti, D.; Zhao, H. G.; Castaño, V. M.; Vomiero, A.; Rosei, F.

    2016-12-01

    Pt/Pd hollow nanofibers were obtained by sputtering a Pt/Pd alloy (80/20 wt%) onto polymer nanofibers (used as sacrificial template) and were used as counter-electrodes (CEs) in dye-sensitized solar cells (DSSCs). We demonstrate that optimization of nanofiber density and Pt/Pd sputtering thickness can increase the short circuit current density and consequently lead to a ∼15% enhancement in power conversion efficiency (PCE), when compared to the commonly used flat Pt/Pd CEs with the same thickness. The processes that contribute to such PCE improvement are: (i) increased surface area provided by the high aspect ratio hollow nanofibers and (ii) improved electro-catalytic performance, as validated by electrochemical impedance spectroscopy (EIS) measurements. The latter showed a two-fold decrease in the charge-transfer resistance of the nanostructured-CE, compared to the flat CE. The contribution of the Pt/Pd hollow nanofiber to light scattering was negligible as shown by reflectance measurements. These results suggest a simple and straightforward strategy to increase PCE in DSSCs, to minimize the use of precious metals used in this kind of devices and, more generally, to tailor the CE structure in photoelectrochemical systems to boost their functional properties, thanks to the advantages afforded by this complex morphology.

  19. Economical Pt-free catalysts for counter electrodes of dye-sensitized solar cells.

    Science.gov (United States)

    Wu, Mingxing; Lin, Xiao; Wang, Yudi; Wang, Liang; Guo, Wei; Qi, Daidi; Peng, Xiaojun; Hagfeldt, Anders; Grätzel, Michael; Ma, Tingli

    2012-02-22

    Three classes (carbides, nitrides and oxides) of nanoscaled early-transition-metal catalysts have been proposed to replace the expensive Pt catalyst as counter electrodes (CEs) in dye-sensitized solar cells (DSCs). Of these catalysts, Cr(3)C(2), CrN, VC(N), VN, TiC, TiC(N), TiN, and V(2)O(3) all showed excellent catalytic activity for the reduction of I(3)(-) to I(-) in the electrolyte. Further, VC embedded in mesoporous carbon (VC-MC) was prepared through in situ synthesis. The I(3)(-)/I(-) DSC based on the VC-MC CE reached a high power conversion efficiency (PCE) of 7.63%, comparable to the photovoltaic performance of the DSC using a Pt CE (7.50%). In addition, the carbide catalysts demonstrated catalytic activity higher than that of Pt for the regeneration of a new organic redox couple of T(2)/T(-). The T(2)/T(-) DSCs using TiC and VC-MC CEs showed PCEs of 4.96 and 5.15%, much higher than that of the DSC using a Pt CE (3.66%). This work expands the list of potential CE catalysts, which can help reduce the cost of DSCs and thereby encourage their fundamental research and commercial application.

  20. A complete carbon counter electrode for high performance quasi solid state dye sensitized solar cell

    Science.gov (United States)

    Arbab, Alvira Ayoub; Peerzada, Mazhar Hussain; Sahito, Iftikhar Ali; Jeong, Sung Hoon

    2017-03-01

    The proposed research describes the design and fabrication of a quasi-solid state dye sensitized solar cells (Q-DSSCs) with a complete carbon based counter electrode (CC-CE) and gel infused membrane electrolyte. For CE, the platinized fluorinated tin oxide glass (Pt/FTO) was replaced by the soft cationic functioned multiwall carbon nanotubes (SCF-MWCNT) catalytic layer coated on woven carbon fiber fabric (CFF) prepared on handloom by interlacing of carbon filament tapes. SCF-MWCNT were synthesized by functionalization of cationised lipase from Candida Ragusa. Cationised enzyme solution was prepared at pH ∼3 by using acetic acid. The cationic enzyme functionalization of MWCNT causes the minimum damage to the tubular morphology and assist in fast anchoring of negative iodide ions present in membrane electrolyte. The high electrocatalytic activity and low charge transfer resistance (RCT = 2.12 Ω) of our proposed system of CC-CE shows that the woven CFF coated with cationised lipase treated carbon nanotubes enriched with positive surface ions. The Q-DSSCs fabricated with CC-CE and 5 wt% PEO gel infused PVDF-HFP membrane electrolyte exhibit power conversion efficiency of 8.90% under masking. Our suggested low cost and highly efficient system of CC-CE helps the proposed quasi-solid state DSSCs structure to stand out as sustainable next generation solar cells.

  1. Nitrogen-Doped Graphene/Platinum Counter Electrodes for Dye-Sensitized Solar Cells

    KAUST Repository

    Lin, Chinan

    2014-12-17

    Nitrogen-doped graphene (NGR) was utilized in dye-sensitized solar cells for energy harvesting. NGR on a Pt-sputtered fluorine-doped tin oxide substrate (NGR/Pt/FTO) as counter electrodes (CEs) achieves the high efficiency of 9.38% via the nitrogen doping into graphene. This is due to (i) the hole-cascading transport at the interface of electrolyte/CEs via controlling the valence band maximum of NGR located between the redox potential of the I-/I- redox couple and the Fermi level of Pt by nitrogen doping, (ii) the extended electron transfer surface effect provided by large-surface-area NGR, (iii) the high charge transfer efficiency due to superior catalytic characteristics of NGR via nitrogen doping, and (iv) the superior light-reflection effect of NGR/Pt/FTO CEs, facilitating the electron transfer from CEs to I3 - ions of the electrolyte and light absorption of dye. The result demonstrated that the NGR/Pt hybrid structure is promising in the catalysis field. (Chemical Presented). © 2014 American Chemical Society.

  2. A transparent nickel selenide counter electrode for high efficient dye-sensitized solar cells

    Science.gov (United States)

    Dong, Jia; Wu, Jihuai; Jia, Jinbiao; Ge, Jinhua; Bao, Quanlin; Wang, Chaotao; Fan, Leqing

    2017-04-01

    Nickel selenide (Ni0.85Se) was synthesized by a facile one-step hydrothermal reaction and Ni0.85Se film was prepared by spin-coating Ni0.85Se ink on FTO and used as counter electrode (CE) in dye-sensitized solar cells (DSSC). The Ni0.85Se CEs not only show high transmittance in visible range, but also possess remarkable electrocatalytic activity toward I-/I3-. The electrocatalytic ability of Ni0.85Se films was verified by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization curves. The DSSC using Ni0.85Se CE exhibits a power conversion efficiency (PCE) of 8.96%, while the DSSC consisting of sputtered Pt CE only exhibits a PCE of 8.15%. When adding a mirror under Ni0.85Se CE, the resultant DSSC exhibits a PCE of 10.76%, which exceeds that of a DSSC based on sputtered Pt CE (8.44%) by 27.49%.

  3. Investigation of Coral-Like Cu2O Nano/Microstructures as Counter Electrodes for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Chih-Hung Tsai

    2015-08-01

    Full Text Available In this study, a chemical oxidation method was employed to fabricate coral-like Cu2O nano/microstructures on Cu foils as counter electrodes (CEs for dye-sensitized solar cells (DSSCs. The Cu2O nano/microstructures were prepared at various sintering temperatures (400, 500, 600 and 700 °C to investigate the influences of the sintering temperature on the DSSC characteristics. First, the Cu foil substrates were immersed in an aqueous solution containing (NH42S2O8 and NaOH. After reacting at 25 °C for 30 min, the Cu substrates were converted to Cu(OH2 nanostructures. Subsequently, the nanostructures were subjected to nitrogen sintering, leading to Cu(OH2 being dehydrated into CuO, which was then deoxidized to form coral-like Cu2O nano/microstructures. The material properties of the Cu2O CEs were comprehensively determined using a scanning electron microscope, energy dispersive X-ray spectrometer, X-ray diffractometer, Raman spectrometer, X-ray photoelectron spectroscope, and cyclic voltameter. The Cu2O CEs sintered at various temperatures were used in DSSC devices and analyzed according to the current density–voltage characteristics, incident photon-to-current conversion efficiency, and electrochemical impedance characteristics. The Cu2O CEs sintered at 600 °C exhibited the optimal electrode properties and DSSC performance, yielding a power conversion efficiency of 3.62%. The Cu2O CEs fabricated on Cu foil were generally mechanically flexible and could therefore be applied to flexible DSSCs.

  4. A dye sensitized solar cell using natural counter electrode and natural dye derived from mangosteen peel waste

    Science.gov (United States)

    Maiaugree, Wasan; Lowpa, Seksan; Towannang, Madsakorn; Rutphonsan, Phikun; Tangtrakarn, Apishok; Pimanpang, Samuk; Maiaugree, Prapen; Ratchapolthavisin, Nattawat; Sang-Aroon, Wichien; Jarernboon, Wirat; Amornkitbamrung, Vittaya

    2015-10-01

    Mangosteen peel is an inedible portion of a fruit. We are interested in using these residues as components of a dye sensitized solar cell (DSSC). Carbonized mangosteen peel was used with mangosteen peel dye as a natural counter electrode and a natural photosensitizer, respectively. A distinctive mesoporous honeycomb-like carbon structure with a rough nanoscale surface was found in carbonized mangosteen peels. The efficiency of a dye sensitized solar cell using carbonized mangosteen peel was compared to that of DSSCs with Pt and PEDOT-PSS counter electrodes. The highest solar conversion efficiency (2.63%) was obtained when using carbonized mangosteen peel and an organic disulfide/thiolate (T2/T-) electrolyte.

  5. Preparation and characterization of chemically deposited nickel sulphide film and its application as a potential counter electrode

    Science.gov (United States)

    Ray, Jaymin; Patel, Mitesh; Ghediya, Prashant; Chaudhuri, Tapas K.

    2016-07-01

    Nickel sulphide (NiS) film has emerged as a counter electrode in many applications, such as thin film batteries, dye sensitized solar cells, and supercapacitors. In this regard, we report the direct liquid coating of pure hexagonal NiS films on glass using a precursor solution of nickel-thiourea complex. A uniform and void free film is observed using scanning electron microscopy. The room temperature electrical conductivity of ˜5 × 103 S cm-1 and the positive thermoelectric power (+6 μV K-1) specify p-type conduction. The temperature variation conductivity in the range 77-300 K depicts the transition of NiS films from conducting to semi-conducting behaviour at certain transition temperatures. Preliminary results from a cyclic voltammetry study shows the feasibility of NiS films as counter electrodes.

  6. Edge-nitrogenated graphene nanoplatelets as high-efficiency counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Wang, Guiqiang; Zhang, Juan; Hou, Shuo; Zhang, Wei; Zhao, Zengdian

    2016-05-01

    Edge-nitrogenated graphene nanoplatelets (ENGNPs) are prepared by a simple and eco-friendly mechanochemical pin-grinding process using flake graphite as the precursor in the presence of nitrogen and investigated as the counter electrodes of dye-sensitized solar cells (DSCs). SEM images and nitrogen adsorption analysis indicate an effective and spontaneous delamination of the pristine graphite into small graphene nanoplatelets by a mechanochemical pin-grinding process. The mechanochemical cracking of the graphitic C-C bond generates activated carbon sites that react directly with nitrogen at the broken edges. The resultant ENGNPs are deposited on a fluorine-doped tin oxide (FTO) substrate by spray coating, and their electrocatalytic activities are investigated systemically in the I-/I3- redox electrolyte. Electrochemical measurements show that the ENGNP electrode possesses excellent electrocatalytic activity for the redox reaction of I-/I3- as evidenced by the low charge-transfer resistance at the interface of the electrode and electrolyte. Under 100 mW cm-2 illumination, the DSC with the optimized ENGNP counter electrode achieves a conversion efficiency of 7.69%, which is comparable to that of the device with Pt counter electrode.Edge-nitrogenated graphene nanoplatelets (ENGNPs) are prepared by a simple and eco-friendly mechanochemical pin-grinding process using flake graphite as the precursor in the presence of nitrogen and investigated as the counter electrodes of dye-sensitized solar cells (DSCs). SEM images and nitrogen adsorption analysis indicate an effective and spontaneous delamination of the pristine graphite into small graphene nanoplatelets by a mechanochemical pin-grinding process. The mechanochemical cracking of the graphitic C-C bond generates activated carbon sites that react directly with nitrogen at the broken edges. The resultant ENGNPs are deposited on a fluorine-doped tin oxide (FTO) substrate by spray coating, and their electrocatalytic

  7. Efficient Dye-Sensitized Solar Cells Made from High Catalytic Ability of Polypyrrole@Platinum Counter Electrode

    OpenAIRE

    Ma, Xingping; Yue, Gentian; Wu, Jihuai; Lan, Zhang

    2015-01-01

    Polypyrrole@platinum (PPy@Pt) composite film was successfully synthesized by using a one-step electrochemical method and served as counter electrode (CE) for efficient dye-sensitized solar cells (DSSCs). The PPy@Pt CE with one-dimensional structure exhibited excellent electrocatalytic activity and superior charge transfer resistance for I−/I3 − electrolyte after being the cyclic voltammetry and electrochemical impedance spectroscopy tested. The photocurrent-photovoltage curves were further us...

  8. Dye-sensitized solar cell with energy storage function through PVDF/ZnO nanocomposite counter electrode.

    Science.gov (United States)

    Zhang, Xi; Huang, Xuezhen; Li, Chensha; Jiang, Hongrui

    2013-08-14

    Dye-sensitized solar cells with an energy storage function are demonstrated by modifying its counter electrode with a poly (vinylidene fluoride)/ZnO nanowire array composite. This simplex device could still function as an ordinary solar cell with a steady photocurrent output even after being fully charged. An energy storage density of 2.14 C g(-1) is achieved, while simultaneously a 3.70% photo-to-electric conversion efficiency is maintained.

  9. Preparation of a Counter Electrode with P-Type NiO and Its Applications in Dye-Sensitized Solar Cell

    Directory of Open Access Journals (Sweden)

    Chuen-Shii Chou

    2010-01-01

    Full Text Available This study investigates the applicability of a counter electrode with a P-type semiconductor oxide (such as NiO on a dye-sensitized solar cell (DSSC. The counter electrode is fabricated by depositing an NiO film on top of a Pt film, which has been deposited on a Fluorine-doped tin oxide (FTO glass using an ion-sputtering coater (or E-beam evaporator, using a simple spin coating method. This study also examines the effect of the average thickness of TiO2 film deposited on a working electrode upon the power conversion efficiency of a DSSC. This study shows that the power conversion efficiency of a DSSC with a Pt(E/NiO counter electrode (4.28% substantially exceeds that of a conventional DSSC with a Pt(E counter electrode (3.16% on which a Pt film was deposited using an E-beam evaporator. This result is attributed to the fact that the NiO film coated on the Pt(E counter electrode improves the electrocatalytic activity of the counter electrode.

  10. Copper Sulfide Catalyzed Porous Fluorine-Doped Tin Oxide Counter Electrode for Quantum Dot-Sensitized Solar Cells with High Fill Factor

    Directory of Open Access Journals (Sweden)

    Satoshi Koyasu

    2017-01-01

    Full Text Available The performance of quantum dot-sensitized solar cell (QDSSC is mainly limited by chemical reactions at the interface of the counter electrode. Generally, the fill factor (FF of QDSSCs is very low because of large charge transfer resistance at the interface between the counter electrode and electrolyte solution containing redox couples. In the present research, we demonstrate the improvement of the resistance by optimization of surface area and amount of catalyst of the counter electrode. A facile chemical synthesis was used to fabricate a composite counter electrode consisting of fluorine-doped tin oxide (FTO powder and CuS nanoparticles. The introduction of a sputtered gold layer at the interface of the porous-FTO layer and underlying glass substrate also markedly reduced the resistance of the counter electrode. As a result, we could reduce the charge transfer resistance and the series resistance, which were 2.5 [Ω] and 6.0 [Ω], respectively. This solar cell device, which was fabricated with the presently designed porous-FTO counter electrode as the cathode and a PbS-modified electrode as the photoanode, exhibited a FF of 58%, which is the highest among PbS-based QDSSCs reported to date.

  11. Structure and Modification of Electrode Materials for Protein Electrochemistry.

    Science.gov (United States)

    Jeuken, Lars J C

    The interactions between proteins and electrode surfaces are of fundamental importance in bioelectrochemistry, including photobioelectrochemistry. In order to optimise the interaction between electrode and redox protein, either the electrode or the protein can be engineered, with the former being the most adopted approach. This tutorial review provides a basic description of the most commonly used electrode materials in bioelectrochemistry and discusses approaches to modify these surfaces. Carbon, gold and transparent electrodes (e.g. indium tin oxide) are covered, while approaches to form meso- and macroporous structured electrodes are also described. Electrode modifications include the chemical modification with (self-assembled) monolayers and the use of conducting polymers in which the protein is imbedded. The proteins themselves can either be in solution, electrostatically adsorbed on the surface or covalently bound to the electrode. Drawbacks and benefits of each material and its modifications are discussed. Where examples exist of applications in photobioelectrochemistry, these are highlighted.

  12. Nanostructured Electrode Materials for Electrochemical Capacitor Applications

    Directory of Open Access Journals (Sweden)

    Hojin Choi

    2015-06-01

    Full Text Available The advent of novel organic and inorganic nanomaterials in recent years, particularly nanostructured carbons, conducting polymers, and metal oxides, has enabled the fabrication of various energy devices with enhanced performance. In this paper, we review in detail different nanomaterials used in the fabrication of electrochemical capacitor electrodes and also give a brief overview of electric double-layer capacitors, pseudocapacitors, and hybrid capacitors. From a materials point of view, the latest trends in electrochemical capacitor research are also discussed through extensive analysis of the literature and by highlighting notable research examples (published mostly since 2013. Finally, a perspective on next-generation capacitor technology is also given, including the challenges that lie ahead.

  13. Carbon-based electrode materials for DNA electroanalysis.

    Science.gov (United States)

    Kato, Dai; Niwa, Osamu

    2013-01-01

    This review addresses recent studies of newly developed carbon-based electrode materials and their use for DNA electroanalysis. Recently, new carbon materials including carbon nanotubes (CNT), graphene and diamond-based nanocarbon electrodes have been actively developed as sensing platforms for biomolecules, such as DNA and proteins. Electrochemical techniques using these new material-based electrodes can provide very simple and inexpensive sensing platforms, and so are expected to be used as one of the "post-light" DNA analysis methods, which include coulometric detection, amperometric detection with electroactive tags or intercalators, and potentiometric detection. DNA electroanalysis using these new carbon materials is summarized in view of recent advances on electrodes.

  14. High-performance dye-sensitized solar cells with gel-coated binder-free carbon nanotube films as counter electrode

    Science.gov (United States)

    Mei, Xiaoguang; Cho, Swee Jen; Fan, Benhu; Ouyang, Jianyong

    2010-10-01

    High-performance dye-sensitized solar cells (DSCs) with binder-free films of carbon nanotubes (CNTs), including single-walled CNTs (SWCNTs) and multi-walled CNTs (MWCNTs), as the counter electrode are reported. The CNT films were fabricated by coating gels, which were prepared by dispersing CNTs in low-molecular-weight poly(ethylene glycol) (PEG) through mechanical grinding and subsequent ultrasonication, on fluorine tin oxide (FTO) glass. PEG was removed from the CNT films through heating. These binder-free CNT films were rough and exhibited good adhesion to substrates. They were used as the counter electrode of DSCs. The DSCs with SWCNT or MWCNT counter electrodes exhibited a light-to-electricity conversion efficiency comparable with that with the conventional platinum (Pt) counter electrode, when the devices were tested immediately after device fabrication. The DSCs with an SWCNT counter electrode exhibited good stability in photovoltaic performance. The efficiency did not decrease after four weeks. On the other hand, DSCs with the MWCNT or Pt counter electrode exhibited a remarkable decrease in the photovoltaic efficiency after four weeks. The high photovoltaic performance of these DSCs is related to the excellent electrochemical catalysis of CNTs on the redox of the iodide/triiodide pair, as revealed by the cyclic voltammetry and ac impedance spectroscopy.

  15. Post-plasma treatment of a carbon nanowall for use as a counter electrode in a dye-sensitized solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yong Ho; Choi, Won Seok [Hanbat National University, Daejeon (Korea, Republic of); Hong, Byung You [Sungkyunkwan University, Suwon (Korea, Republic of)

    2014-08-15

    This research investigates plasma-treated carbon nanowalls (CNW) for use as counter electrodes in dye-sensitized solar cells (DSSCs). The CNWs were synthesized on a fluorine-tin-oxide (FTO) glass substrate via microwave plasma-enhanced chemical vapor-deposition (PECVD) using CH{sub 4} gas. Then, post-plasma treatments were performed on the CNWs in different plasma environments (using O{sub 2}, H{sub 2} and N{sub 2} gas) under the same conditions, after which DSSCs were fabricated using the plasma-treated CNWs as counter electrodes. Scanning electron microscopy (SEM) was performed to obtain cross-sectional and planar images of the CNWs, and Raman spectroscopy was used to analyze the structural characteristics of the post-plasma-treated synthesized CNWs. The energy conversion efficiency was then used to analyze the effect of using the plasma-treated CNWs as counter electrodes in the DSSCs. The DSSC for which the as-deposited CNW was used as a counter electrode showed an energy conversion efficiency of 1.64%, and the DSSC with the H{sub 2} post plasma-treated CNW counter electrode showed an energy conversion efficiency of 2.23%. Thus, the DSSC with the H{sub 2}-treated electrode presented a 36% higher efficiency than the DSSC with the as-deposited CNW electrode.

  16. Aqueous processing of composite lithium ion electrode material

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jianlin; Armstrong, Beth L.; Daniel, Claus; Wood, III, David L.

    2017-06-20

    A method of making a battery electrode includes the steps of dispersing an active electrode material and a conductive additive in water with at least one dispersant to create a mixed dispersion; treating a surface of a current collector to raise the surface energy of the surface to at least the surface tension of the mixed dispersion; depositing the dispersed active electrode material and conductive additive on a current collector; and heating the coated surface to remove water from the coating.

  17. Pulsed voltage deposited lead selenide thin film as efficient counter electrode for quantum-dot-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Bin Bin [Key Laboratory of Macromolecular Science of Shaanxi Province & School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China); Department of Chemical Engineering, Institute of Chemical Industry, Shaanxi Institute of Technology, Xi’an 710300 (China); Wang, Ye Feng [Key Laboratory of Macromolecular Science of Shaanxi Province & School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China); Wang, Xue Qing [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Zeng, Jing Hui, E-mail: jhzeng@ustc.edu [Key Laboratory of Macromolecular Science of Shaanxi Province & School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China)

    2016-04-30

    Highlights: • PbSe thin film is deposited on FTO glass by a pulse voltage electrodeposition method. • The thin film is used as counter electrode (CE) in quantum dot-sensitized solar cell. • Superior electrocatalytic activity and stability in the polysulfide electrolyte is received. • The narrow band gap characteristics and p-type conductivity enhances the cell efficiency. • An efficiency of 4.67% is received for the CdS/CdSe co-sensitized solar cells. - Abstract: Lead selenide (PbSe) thin films were deposited on fluorine doped tin oxide (FTO) glass by a facile one-step pulse voltage electrodeposition method, and used as counter electrode (CE) in CdS/CdSe quantum dot-sensitized solar cells (QDSSCs). A power conversion efficiency of 4.67% is received for the CdS/CdSe co-sensitized solar cells, which is much better than that of 2.39% received using Pt CEs. The enhanced performance is attributed to the extended absorption in the near infrared region, superior electrocatalytic activity and p-type conductivity with a reflection of the incident light at the back electrode in addition. The physical and chemical properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), reflectance spectra, electrochemical impedance spectroscopy (EIS) and Tafel polarization measurements. The present work provides a facile pathway to an efficient CE in the QDSSCs.

  18. MoS2 atomic layers with artificial active edge sites as transparent counter electrodes for improved performance of dye-sensitized solar cells.

    Science.gov (United States)

    Zhang, Jing; Najmaei, Sina; Lin, Hong; Lou, Jun

    2014-05-21

    A novel MoS2 transparent counter electrode for dye-sensitized solar cells is reported. In order to enhance the catalytic activity of the electrode, active edge sites are created artificially by patterning holes on MoS2 atomic layers. Electrochemical analysis shows that the electrochemical activity is significantly improved after the patterning of holes. The photon-to-electron efficiency of the dye-sensitized solar cells based on MoS2 atomic layer counter electrodes is increased remarkably from 2% to 5.8% after the hole patterning.

  19. Materials analyses and electrochemical impedance of implantable metal electrodes.

    Science.gov (United States)

    Howlader, Matiar M R; Ul Alam, Arif; Sharma, Rahul P; Deen, M Jamal

    2015-04-21

    Implantable electrodes with high flexibility, high mechanical fixation and low electrochemical impedance are desirable for neuromuscular activation because they provide safe, effective and stable stimulation. In this paper, we report on detailed materials and electrical analyses of three metal implantable electrodes - gold (Au), platinum (Pt) and titanium (Ti) - using X-ray photoelectron spectroscopy (XPS), scanning acoustic microscopy, drop shape analysis and electrochemical impedance spectroscopy. We investigated the cause of changes in electrochemical impedance of long-term immersed Au, Pt and Ti electrodes on liquid crystal polymers (LCPs) in phosphate buffered saline (PBS). We analyzed the surface wettability, surface and interface defects and the elemental depth profile of the electrode-adhesion layers on the LCP. The impedance of the electrodes decreased at lower frequencies, but increased at higher frequencies compared with that of the short-term immersion. The increase of impedances was influenced by the oxidation of the electrode/adhesion-layers that affected the double layer capacitance behavior of the electrode/PBS. The oxidation of the adhesion layer for all the electrodes was confirmed by XPS. Alkali ions (sodium) were adsorbed on the Au and Pt surfaces, but diffused into the Ti electrode and LCPs. The Pt electrode showed a higher sensitivity to surface and interface defects than that of Ti and Au electrodes. These findings may be useful when designing electrodes for long-term implantable devices.

  20. A branching NiCuPt alloy counter electrode for high-efficiency dye-sensitized solar cell

    Science.gov (United States)

    Yang, Peizhi; Tang, Qunwei

    2016-01-01

    A rising objective for high-efficiency dye-sensitized solar cells (DSSCs) is to create extraordinary and cost-effective counter electrode (CE) electrocatalysts. We present here a branching NiCuPt alloy CE synthesized by electrodepositing Ni on ZnO microrod templates and subsequently growing branched Cu as well as suffering from a galvanic displacement for Pt uptake. The resultant NiCuPt alloy CE displays a promising electrocatalytic activity toward redox electrolyte having I-/I3- couples. An impressive power conversion efficiency of 9.66% is yielded for the liquid-junction DSSC platform.

  1. Efficiency enhancement for dye-sensitized solar cells with a porous NiO/Pt counter electrode

    Science.gov (United States)

    Maiaugree, Wasan; Kongprakaiwoot, Natcharee; Tangtrakarn, Apishok; Saekow, Samarn; Pimanpang, Samuk; Amornkitbamrung, Vittaya

    2014-01-01

    Bi-layer counter electrodes made of platinum films (Pt) coated on porous nickel oxide nanosheets (PNO) were investigated for a dye sensitized solar cell (DSSC). The PNO and Pt films were deposited using a chemical bath deposition and a DC sputtering technique, respectively. Connected networks of sputtered Pt on PNO nanosheets significantly enhanced electrocatalytic activities due to the increase in the electroactive areas. The solar conversion efficiency of the FTO/PNO/Pt DSSC was 8.17% in comparison to 7.23% for the FTO/Pt DSSC.

  2. Electrode materials for microbial fuel cells: nanomaterial approach

    KAUST Repository

    Mustakeem, Mustakeem

    2015-11-05

    Microbial fuel cell (MFC) technology has the potential to become a major renewable energy resource by degrading organic pollutants in wastewater. The performance of MFC directly depends on the kinetics of the electrode reactions within the fuel cell, with the performance of the electrodes heavily influenced by the materials they are made from. A wide range of materials have been tested to improve the performance of MFCs. In the past decade, carbon-based nanomaterials have emerged as promising materials for both anode and cathode construction. Composite materials have also shown to have the potential to become materials of choice for electrode manufacture. Various transition metal oxides have been investigated as alternatives to conventional expensive metals like platinum for oxygen reduction reaction. In this review, different carbon-based nanomaterials and composite materials are discussed for their potential use as MFC electrodes.

  3. Solution-Processed Transparent Nickel-Mesh Counter Electrode with in-Situ Electrodeposited Platinum Nanoparticles for Full-Plastic Bifacial Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Khan, Arshad; Huang, Yu-Ting; Miyasaka, Tsutomu; Ikegami, Masashi; Feng, Shien-Ping; Li, Wen-Di

    2017-03-08

    A new type of embedded metal-mesh transparent electrode (EMTE) with in-situ electrodeposited catalytic platinum nanoparticles (PtNPs) is developed as a high-performance counter electrode (CE) for lightweight flexible bifacial dye-sensitized solar cells (DSSCs). The thick but narrow nickel micromesh fully embedded in a plastic film provides superior electrical conductivity, optical transmittance, and mechanical stability to the novel electrode. PtNPs decorated selectively on the nickel micromesh surface provide catalytic function with minimum material cost and without interfering with optical transparency. Facile and fully solution-processed fabrication of the novel CE is demonstrated with potential for scalable and cost-effective production. Using this PtNP-decorated nickel EMTE as the CE and titanium foil as the photoanode, unifacial flexible DSSCs are fabricated with a power conversion efficiency (PCE) of 6.91%. By replacing the titanium foil with a transparent ITO-PEN photoanode, full-plastic bifacial DSSCs are fabricated and tested, demonstrating a remarkable PCE of 4.87% under rear-side illumination, which approaches 85% of the 5.67% PCE under front-side illumination, among the highest ratio in published results. These promising results reveal the enormous potential of this hybrid transparent CE in scalable production and commercialization of low-cost and efficient flexible DSSCs.

  4. Enhancement of the efficiency of dye-sensitized solar cell with multi-wall carbon nanotubes/polythiophene composite counter electrodes prepared by electrodeposition

    Science.gov (United States)

    Luo, Jun; Niu, Hai-jun; Wu, Wen-jun; Wang, Cheng; Bai, Xu-duo; Wang, Wen

    2012-01-01

    For the purpose of increasing the energy conversion efficiency of dye-sensitized solar cells (DSSCs), multi-wall carbon nanotube (MWCNT)/polythiophene (PTh) composite film counter electrode has been fabricated by electrophoresis and cyclic voltammetry (CV) in sequence. The morphology and chemical structure have been characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM), and Raman spectroscopy respectively. The overall energy conversion efficiency of the DSSC employing the MWCNT/PTh composite film has reached 4.72%, which is close to that of the DSSC with a platinum (Pt) counter electrode (5.68%). Compared with a standard DSSC with MWCNT counter electrode whose efficiency is 2.68%, the energy conversion efficiency has been increased by 76.12% for the DSSC with MWCNT/PTh counter electrode. These results indicate that the composite film with high conductivity, high active surface area, and good catalytic properties for I 3- reduction can potentially be used as the counter electrode in a high-performance DSSC.

  5. Synthesis and evaluation of polythiocyanogen (SCN) x as a rechargeable lithium-ion battery electrode material

    Science.gov (United States)

    Krishnan, Palanichamy; Advani, Suresh G.; Prasad, Ajay K.

    Polythiocyanogen, (SCN) x, is a promising lithium-ion battery electrode material due to its high theoretical capacity (462 mAh g -1), safe operation, inexpensive raw materials, and a simple and less energy-intensive manufacturing process. The (SCN) x was prepared from the solution of trithiocyanate (SCN) 3 - in methylene dichloride (MDC), which was prepared by electrochemical oxidation of ammonium thiocyanate (NH 4SCN) in a two-phase electrolysis medium of 1.0 M NH 4SCN in 0.50 M H 2SO 4 + MDC. The (SCN) 3 - underwent auto catalytic polymerization to (SCN) x during MDC removal. Battery electrodes with (SCN) x as the active material were prepared, and tested in Swagelok cells using lithium foil as the counter and reference electrode. The cells delivered capacities in the range of 200-275 mAh g -1 at the discharge-charge rate of 0.2 C. The cells were tested up to 20 cycles and showed repeatable performance with a coulombic efficiency of 97% at the 20th cycle. The results presented here indicate that (SCN) x is a promising lithium-ion battery electrode-material candidate for further studies.

  6. NiO-NF/MWCNT nanocomposite catalyst as a counter electrode for high performance dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Raissan Al-bahrani, Majid [Center for Nanoscale Characterization & Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology - HUST, Luoyu Road 1037, Wuhan 430074 (China); Faculty of Science, Thi-Qar University, Nassiriya (Iraq); Liu, Linfeng [Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074 (China); Ahmad, Waqar; Tao, Jiayou; Tu, Fanfan [Center for Nanoscale Characterization & Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology - HUST, Luoyu Road 1037, Wuhan 430074 (China); Cheng, Ze [School of Physics, Huazhong University of Science and Technology (HUST), Luoyu Road 1037, Wuhan 430074 (China); Gao, Yihua, E-mail: gaoyihua@hust.edu.cn [Center for Nanoscale Characterization & Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology - HUST, Luoyu Road 1037, Wuhan 430074 (China)

    2015-03-15

    Highlights: • High-performance NiO-NF/MWCNT CE was incorporated in a Pt-CE in DSSCs. • NiO-NF/MWCNT CE exhibits a high power conversion efficiency (PCE) of 7.63%. • NiO-NF/MWCNT composite has a high catalytic activity for the reduction of I{sub 3}{sup −}. • NiO-NF/MWCNT composite has a low R{sub ct} on the electrolyte/CE interface. - Abstract: In this paper, we fabricated nickel oxide nanofilament/multiwall carbon nanotubes (NiO-NF/MWCNT) nanocomposite by a simple hydrothermal synthesis method as a counter- electrode (CE) in a dye-sensitized solar cell (DSSC). Transmission electron microscopy, scanning electron microscopy images and X-ray diffraction analysis clearly indicated the formation of NiO-NF/MWCNT nanocomposite. The electro-chemical properties of NiO-NF/MWCNT CE are studied by cyclic voltammetry and electrochemical impedance spectroscopy. In particular, current-voltage measurements indicated superior power conversion efficiency (PCE) of 7.63% of the NiO-NF/MWCNT CE compared to 6.72% for the platinum (Pt). The superior photovoltaic performance and low cost of the NiO-NF/MWCNT nanocomposite can be potentially exploited as a new counter-electrode in DSSCs.

  7. A unique semiconductor-carbon-metal hybrid structure design as a counter electrode in dye-sensitized solar cells.

    Science.gov (United States)

    Guo, Sheng-Qi; Wang, Ling-Chang; Zhang, Chen-Guang; Qi, Gao-Can; Gu, Bing-Chuan; Liu, Lu; Yuan, Zhi-Hao

    2017-05-25

    The catalytic activity of counter electrodes (CEs) severely restricts the photovoltaic conversion efficiency of dye-sensitized solar cells. However, electrons trapped by bulk defects greatly reduce the catalytic activity of the CE. In this study, we report a novel In2S3-C-Au hybrid structure designed by simply decorating Au particles on the surface of carbon-coated hierarchical In2S3 flower-like architectures, which could avoid the abovementioned problems. This effect can be attributed to the unique contribution of indium sulfide, carbon, and Au from the hybrid structure, as well as to their synergy. Electrochemical measurements revealed that the hybrid structure possessed high catalytic activity and electrochemical stability for the interconversion of the redox couple I3(-)/I(-). Moreover, this superior performance can be incorporated into the dye-sensitized solar cells system. We used this hybrid structure as a counter electrode by casting it on an FTO substrate to form a film, which displayed better photovoltaic conversion efficiency (8.91%) than the commercial Pt counterpart (7.67%).

  8. CoS acicular nanorod arrays for the counter electrode of an efficient dye-sensitized solar cell.

    Science.gov (United States)

    Kung, Chung-Wei; Chen, Hsin-Wei; Lin, Chia-Yu; Huang, Kuan-Chieh; Vittal, R; Ho, Kuo-Chuan

    2012-08-28

    One-dimensional cobalt sulfide (CoS) acicular nanorod arrays (ANRAs) were obtained on a fluorine-doped tin oxide (FTO) substrate by a two-step approach. First, Co(3)O(4) ANRAs were synthesized, and then they were converted to CoS ANRAs for various periods. The compositions of the films obtained after various conversion periods were verified by X-ray diffraction, UV-visible spectrophotometry, and X-ray photoelectron spectroscopy; their morphologies were examined at different periods by scanning electron microscopic and transmission electron microscopic images. Electrocatalytic abilities of the films toward I(-)/I(3)(-) were verified through cyclic voltammetry (CV) and Tafel polarization curves. Long-term stability of the films in I(-)/I(3)(-) electrolyte was studied by CV. The FTO substrates with CoS ANRAs were used as the counter electrodes for dye-sensitized solar cells; a maximum power conversion efficiency of 7.67% was achieved for a cell with CoS ANRAs, under 100 mW/cm(2), which is nearly the same as that of a cell with a sputtered Pt counter electrode (7.70%). Electrochemical impedance spectroscopy was used to substantiate the photovoltaic parameters.

  9. Production of graphitic carbon-based nanocomposites from K2CO3-activated coconut shells as counter electrodes for dye-sensitized solar-cell applications

    Science.gov (United States)

    Loryuenyong, Vorrada; Buasri, Achanai; Lerdvilainarit, Parichat; Manachevakulm, Konnatee; Sompong, Siripond

    2016-01-01

    In this study, graphitic carbon-activated carbon nanocomposites fabricated from K2CO3 chemically-activated coconut shells by using Fe-catalytic chemical vapor deposition are reported. The present method was simple, environmentally-friendly, low cost, but successfully offered graphitic carbon-based materials that demonstrated promise for use as counter electrodes in dye-sensitized solar cells. The results showed that the coconut shell:catalyst ratio (1:0, 1:4, 1:1, and 4:1) significantly affected the structural, physical and electrochemical properties of the samples. Graphitic carbon and activated carbon nanocomposites with a high specific surface area of 1230 m2/g and high electrochemical activity in iodide reduction are obtained for samples with a coconut shells/iron precursor (Fe(NO3)3) ratio of 4:1.

  10. Influence of Cu vacancy on knit coir mat structured CuS as counter electrode for quantum dot sensitized solar cells.

    Science.gov (United States)

    Savariraj, A Dennyson; Viswanathan, Kodakkal Kannan; Prabakar, Kandasamy

    2014-11-26

    Knit-coir-mat-like structured CuS thin films prepared by chemical bath deposition with different time duration were used as counter electrode in qunatum dot sensitized solar cells. The film deposited at 4 h exhibited better electrochemical and photovoltaic performance with JSC, VOC, and FF values of 14.584 mA cm(-2), 0.566 V, and 54.57% and efficiency of 4.53%. From the UV-vis absorption spectra, it is observed that CuS thin film exhibits free carrier intraband absorption in the longer wavelengh region. The enhanced performance of CuS counter electrodes is due to Cu vacancies with increased S composition, and the quasi-Fermi energy level in semiconductors with respect to electrolyte redox potential is one of the causes that affects the electrocatalytic activity of counter electrodes.

  11. Mn based olivine electrode material with high power and energy.

    Science.gov (United States)

    Kim, Jongsoon; Seo, Dong-Hwa; Kim, Sung-Wook; Park, Young-Uk; Kang, Kisuk

    2010-02-28

    We report the Mn based olivine electrode material with high power and energy. Easier and more frequent nucleation by Fe and Co in Mn-based olivines significantly enhanced the rate capability as evidenced by the electrochemical results.

  12. Preliminary study on zinc-air battery using zinc regeneration electrolysis with propanol oxidation as a counter electrode reaction

    Science.gov (United States)

    Wen, Yue-Hua; Cheng, Jie; Ning, Shang-Qi; Yang, Yu-Sheng

    A zinc-air battery using zinc regeneration electrolysis with propanol oxidation as a counter electrode reaction is reported in this paper. It possesses functions of both zincate reduction and electrochemical preparation, showing the potential for increasing the electronic energy utilization. Charge/discharge tests and scanning electron microscopy (SEM) micrographs reveal that when a nickel sheet plated with the high-H 2-overpotential metal, cadmium, was used as the negative substrate electrode, the dendritic formation and hydrogen evolution are suppressed effectively, and granular zinc deposits become larger but relatively dense with the increase of charge time. The performance of batteries is favorable even if the charge time is as long as 5 h at the current density of 20 mA cm -2. Better discharge performance is achieved using a 'cavity-opening' configuration for the discharge cell rather than a 'gas-introducing' configuration. The highest energy efficiency is up to 59.2%. That is, the energy consumed by organic electro-synthesis can be recovered by 59.2%. Cyclic voltammograms show that the sintered nickel electrode exhibits a good electro-catalysis activity for the propanol oxidation. The increase of propanol concentration conduces to an enhancement in the organic electro-synthesis efficiency. The organic electro-synthesis current efficiency of 82% can be obtained.

  13. Fuel cell electrode interconnect contact material encapsulation and method

    Science.gov (United States)

    Derose, Anthony J.; Haltiner, Jr., Karl J.; Gudyka, Russell A.; Bonadies, Joseph V.; Silvis, Thomas W.

    2016-05-31

    A fuel cell stack includes a plurality of fuel cell cassettes each including a fuel cell with an anode and a cathode. Each fuel cell cassette also includes an electrode interconnect adjacent to the anode or the cathode for providing electrical communication between an adjacent fuel cell cassette and the anode or the cathode. The interconnect includes a plurality of electrode interconnect protrusions defining a flow passage along the anode or the cathode for communicating oxidant or fuel to the anode or the cathode. An electrically conductive material is disposed between at least one of the electrode interconnect protrusions and the anode or the cathode in order to provide a stable electrical contact between the electrode interconnect and the anode or cathode. An encapsulating arrangement segregates the electrically conductive material from the flow passage thereby, preventing volatilization of the electrically conductive material in use of the fuel cell stack.

  14. Toward Uniformly Dispersed Battery Electrode Composite Materials: Characteristics and Performance.

    Science.gov (United States)

    Kwon, Yo Han; Huie, Matthew M; Choi, Dalsu; Chang, Mincheol; Marschilok, Amy C; Takeuchi, Kenneth J; Takeuchi, Esther S; Reichmanis, Elsa

    2016-02-10

    Battery electrodes are complex mesoscale systems comprised of electroactive components, conductive additives, and binders. In this report, methods for processing electrodes with dispersion of the components are described. To investigate the degree of material dispersion, a spin-coating technique was adopted to provide a thin, uniform layer that enabled observation of the morphology. Distinct differences in the distribution profile of the electrode components arising from individual materials physical affinities were readily identified. Hansen solubility parameter (HSP) analysis revealed pertinent surface interactions associated with materials dispersivity. Further studies demonstrated that HSPs can provide an effective strategy to identify surface modification approaches for improved dispersions of battery electrode materials. Specifically, introduction of surfactantlike functionality such as oleic acid (OA) capping and P3HT-conjugated polymer wrapping on the surface of nanomaterials significantly enhanced material dispersity over the composite electrode. The approach to the surface treatment on the basis of HSP study can facilitate design of composite electrodes with uniformly dispersed morphology and may contribute to enhancing their electrical and electrochemical behaviors. The conductivity of the composites and their electrochemical performance was also characterized. The study illustrates the importance of considering electronic conductivity, electron transfer, and ion transport in the design of environments incorporating active nanomaterials.

  15. Effect of oxidation of carbon material on suspension electrodes for flow electrode capacitive deionization.

    Science.gov (United States)

    Hatzell, Kelsey B; Hatzell, Marta C; Cook, Kevin M; Boota, Muhammad; Housel, Gabrielle M; McBride, Alexander; Kumbur, E Caglan; Gogotsi, Yury

    2015-03-03

    Flow electrode deionization (FCDI) is an emerging area for continuous and scalable deionization, but the electrochemical and flow properties of the flow electrode need to be improved to minimize energy consumption. Chemical oxidation of granular activated carbon (AC) was examined here to study the role of surface heteroatoms on rheology and electrochemical performance of a flow electrode (carbon slurry) for deionization processes. Moreover, it was demonstrated that higher mass densities could be used without increasing energy for pumping when using oxidized active material. High mass-loaded flow electrodes (28% carbon content) based on oxidized AC displayed similar viscosities (∼21 Pa s) to lower mass-loaded flow electrodes (20% carbon content) based on nonoxidized AC. The 40% increased mass loading (from 20% to 28%) resulted in a 25% increase in flow electrode gravimetric capacitance (from 65 to 83 F g(-1)) without sacrificing flowability (viscosity). The electrical energy required to remove ∼18% of the ions (desalt) from of the feed solution was observed to be significantly dependent on the mass loading and decreased (∼60%) from 92 ± 7 to 28 ± 2.7 J with increased mass densities from 5 to 23 wt %. It is shown that the surface chemistry of the active material in a flow electrode effects the electrical and pumping energy requirements of a FCDI system.

  16. Low-cost counter electrodes from CoPt alloys for efficient dye-sensitized solar cells.

    Science.gov (United States)

    He, Benlin; Meng, Xin; Tang, Qunwei

    2014-04-09

    Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its merits on clean, low cost, high efficiency, good durability, and easy fabrication. However, the commercial application of DSSCs has been hindered by the high expenses of counter electrodes (CEs) and limited power conversion efficiency. With an aim of significantly enhancing the power conversion efficiency, here we pioneerly synthesize CoPt alloys using an electrochemically codeposition technique which are employed as CEs for DSSCs. Owing to the rapid charge transfer, electrical conduction, and electrocatalysis, power conversion efficiencies of CoPt-based DSSCs have been markedly elevated in comparison with the DSSC using Pt CE. The DSSC employing CoPt0.02 alloy CE gives an impressive power conversion efficiency of 10.23%. The high conversion efficiency, low cost in combination with simple preparation, and scalability demonstrates the potential use of CoPt alloys in robust DSSCs.

  17. Efficient Dye-Sensitized Solar Cells Made from High Catalytic Ability of Polypyrrole@Platinum Counter Electrode

    Science.gov (United States)

    Ma, Xingping; Yue, Gentian; Wu, Jihuai; Lan, Zhang

    2015-08-01

    Polypyrrole@platinum (PPy@Pt) composite film was successfully synthesized by using a one-step electrochemical method and served as counter electrode (CE) for efficient dye-sensitized solar cells (DSSCs). The PPy@Pt CE with one-dimensional structure exhibited excellent electrocatalytic activity and superior charge transfer resistance for I-/I3 - electrolyte after being the cyclic voltammetry and electrochemical impedance spectroscopy tested. The photocurrent-photovoltage curves were further used to calculate the theoretical photoelectric performance parameters of the DSSCs. The DSSC based on the PPy@Pt CE achieved a remarkable power conversion efficiency of 7.35 %, higher about 19.9 % than that of conventional Pt CE (6.13 %). This strategy provides a new opportunity for fabricating low-cost and highly efficient DSSCs.

  18. The CdS/CdSe/ZnS Photoanode Cosensitized Solar Cells Basedon Pt, CuS, Cu2S, and PbS Counter Electrodes

    Directory of Open Access Journals (Sweden)

    Tung Ha Thanh

    2014-01-01

    Full Text Available Highly ordered mesoporous TiO2 modified by CdS, CdSe, and ZnS quantum dots (QDs was fabricated by successive ionic layer adsorption and reaction (SILAR method. The quantity of material deposition seems to be affected not only by the employed deposition method but also and mainly by the nature of the underlying layer. The CdS, CdSe, and ZnS QDs modification expands the photoresponse range of mesoporous TiO2 from ultraviolet region to visible range, as confirmed by UV-Vis spectrum. Optimized anode electrodes led to solar cells producing high current densities. Pt, CuS, PbS, and Cu2S have been used as electrocatalysts on counter electrodes. The maximum solar conversion efficiency reached in this work was 1.52% and was obtained by using Pt electrocatalyst. CuS, PbS, and Cu2S gave high currents and this was in line with the low charge transfer resistances recorded in their case.

  19. One-step fabrication of copper sulfide nanoparticles decorated on graphene sheets as highly stable and efficient counter electrode for CdS-sensitized solar cells

    Science.gov (United States)

    Hessein, Amr; Wang, Feiju; Masai, Hirokazu; Matsuda, Kazunari; Abd El-Moneim, Ahmed

    2016-11-01

    Quantum-dot-sensitized solar cells (QDSSCs) are thin-film photovoltaics and highly promising as next-generation solar cells owing to their high theoretical efficiency, easy fabrication process, and low production cost. However, the practical photoconversion efficiencies (PCEs) of QDSSCs are still far below the theoretically estimated value owing to the lack of an applicable design of the materials and electrodes. In this work, we developed a highly stable and efficient counter electrode (CE) from copper sulfide nanocrystals and reduced graphene oxide (Cu x S@RGO) for QDSSC applications. The Cu x S@RGO electrocatalyst was successfully prepared by a facile one-pot hydrothermal method, then directly applied to a fluorine-doped tin oxide (FTO)-coated glass substrate by the simple drop-casting technique. Owing to the synergistic effect between Cu x S nanocrystals and conductive RGO sheets, the Cu x S@RGO CE showed high electrocatalytic activity for polysulfide electrolyte reduction. A CdS QDSSC based on the Cu x S@RGO CE yielded a high and reproducible PCE of 2.36%, exceeding those of 1.57 and 1.33% obtained with the commonly used Cu2S/brass and Pt CEs, respectively. Moreover, the QDSSC with the Cu x S@RGO CE showed excellent photostability in a light-soaking test without any obvious decay in the photocurrent, whereas the cell based on the Cu2S/brass CE was severely degraded.

  20. Towards Flexible Transparent Electrodes Based on Carbon and Metallic Materials

    Directory of Open Access Journals (Sweden)

    Minghui Luo

    2017-01-01

    Full Text Available Flexible transparent electrodes (FTEs with high stability and scalability are in high demand for the extremely widespread applications in flexible optoelectronic devices. Traditionally, thin films of indium thin oxide (ITO served the role of FTEs, but film brittleness and scarcity of materials limit its further application. This review provides a summary of recent advances in emerging transparent electrodes and related flexible devices (e.g., touch panels, organic light-emitting diodes, sensors, supercapacitors, and solar cells. Mainly focusing on the FTEs based on carbon nanomaterials (e.g., carbon nanotubes and graphene and metal materials (e.g., metal grid and metal nanowires, we discuss the fabrication techniques, the performance improvement, and the representative applications of these highly transparent and flexible electrodes. Finally, the challenges and prospects of flexible transparent electrodes will be summarized.

  1. Transition metal doped poly(aniline-co-pyrrole)/multi-walled carbon nanotubes nanocomposite for high performance supercapacitor electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Dhibar, Saptarshi; Bhattacharya, Pallab; Hatui, Goutam; Das, C.K., E-mail: chapal12@yahoo.co.in

    2015-03-15

    Highlights: • The CuCl{sub 2} doped copolymer (PANI and PPy)/MWCNTs nanocomposite was prepared. • The nanocomposite achieved highest specific capacitance of 383 F/g at a 0.5 A/g. • Nanocomposite exhibits better energy density as well as power density. • The nanocomposite also showed better electrical conductivity at room temperature. • The nanocomposite can be used as promising electrode materials for supercapacitor. - Abstract: In this present communication, copolymer of polyaniline (PANI) and polypyrrole (PPy) that is poly(aniline-co-pyrrole) [poly(An-co-Py)], copper chloride (CuCl{sub 2}) doped poly(aniline-co-pyrrole) [poly(An-co-Py) Cu], and CuCl{sub 2} doped poly(aniline-co-pyrrole)/multi walled carbon nanotubes (MWCNTs) [poly(An-co-Py) Cu CNT] nanocomposite have been prepared by a simple and inexpensive in-situ chemical oxidative polymerization method, using ammonium persulfate (APS) as oxidant and hydrochloric acid (HCl) as dopant and investigated as high performance supercapacitor electrode materials. The possible interaction between CuCl{sub 2} with copolymers and MWCNTs was investigated by Fourier transform infrared spectroscopy (FTIR) and UV–visible spectroscopy analysis. The morphological characteristic of all the electrode materials were analyzed by Field emission scanning electron microscopy (FESEM) and Transmission electron microscopy (TEM) study. The electrochemical characterizations of all the electrode materials were carried out by three electrode probe method where, standard calomel electrode and platinum were used as reference and counter electrodes, respectively. Among all the electrode materials, poly(An-co-Py) Cu CNT nanocomposite achieved highest specific capacitance value of 383 F/g at 0.5 A/g scan rate. The nanocomposite showed better electrical conductivity at room temperature and also attained nonlinear current–voltage characteristic. Based on the superior electrochemical as well as other properties the as prepared

  2. Nanostructured Electrode Materials for Fuel Cells and Supercapacitors

    Institute of Scientific and Technical Information of China (English)

    W.Sugimoto; T.Saida; Y.Takasu

    2007-01-01

    1 Results Owing to its electrochemical stability, catalytic activity and high electrical conductivity, ruthenium-based oxides have been realized in electrochemistry as excellent electrode materials with applications ranging from electrocatalysts for industrial electrolysis to high power energy storage. Recent studies have suggested that RuOx may have an active role in electrocatalysts for fuel cells.We have been engaged in the fundamental and practical study of nanostructured RuO2-based electrodes[1-5]....

  3. Graphene oxide - Polyvinyl alcohol nanocomposite based electrode material for supercapacitors

    Science.gov (United States)

    Pawar, Pranav Bhagwan; Shukla, Shobha; Saxena, Sumit

    2016-07-01

    Supercapacitors are high capacitive energy storage devices and find applications where rapid bursts of power are required. Thus materials offering high specific capacitance are of fundamental interest in development of these electrochemical devices. Graphene oxide based nanocomposites are mechanically robust and have interesting electronic properties. These form potential electrode materials efficient for charge storage in supercapacitors. In this perspective, we investigate low cost graphene oxide based nanocomposites as electrode material for supercapacitor. Nanocomposites of graphene oxide and polyvinyl alcohol were synthesized in solution phase by integrating graphene oxide as filler in polyvinyl alcohol matrix. Structural and optical characterizations suggest the formation of graphene oxide and polyvinyl alcohol nanocomposites. These nanocomposites were found to have high specific capacitance, were cyclable, ecofriendly and economical. Our studies suggest that nanocomposites prepared by adding 0.5% wt/wt of graphene oxide in polyvinyl alcohol can be used an efficient electrode material for supercapacitors.

  4. Layer-by-layer self-assembled mesoporous PEDOT-PSS and carbon black hybrid films for platinum free dye-sensitized-solar-cell counter electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, Koji; Shiratori, Seimei [School of Integrated Design Engineering, Keio University, Yokohama 223-8522 (Japan)

    2011-05-13

    A thin film of poly(3,4-ethylenedioxythiophene)-poly(4-styrenesulfonic acid) (PEDOT-PSS), which is an alternative cathodic catalyst for Pt in dye-sensitized solar cells, was prepared using the layer-by-layer self-assembly method (LbL). The film is highly adhesive to the substrate and has a controllable thickness. Therefore, the PEDOT-PSS film prepared using LbL is expected have high performance and durability as a counter electrode. Moreover, when carbon black was added to the PEDOT-PSS solution, highly mesoporous PEDOT-PSS and carbon black hybrid films were obtained. These films showed high cathodic activity. In this study, we investigated the change in morphology in the obtained film with increasing carbon black content, and the influence of the porosity and thickness on the performance of the cells. In this study, a Pt-free counter electrode with performance similar to that of Pt-based counter electrodes was successfully fabricated. The achieved efficiency of 4.71% was only a factor of 8% lower than that of the cell using conventional thermally deposited Pt on fluorine-doped tin oxide glass counter electrodes.

  5. Pulse-reverse electrodeposition of transparent nickel phosphide film with porous nanospheres as a cost-effective counter electrode for dye-sensitized solar cells.

    Science.gov (United States)

    Wu, Mao-Sung; Wu, Jia-Fang

    2013-12-01

    A Ni2P nanolayer with porous nanospheres was directly coated on fluorine-doped tin oxide glass by pulse-reverse deposition as a low-cost counter electrode catalyst for dye-sensitized solar cells, and the photoelectron conversion efficiency of the cell was increased to 7.32% by using a porous nanosphere catalyst due to the significantly improved ion transport.

  6. Layer-by-layer self-assembled mesoporous PEDOT-PSS and carbon black hybrid films for platinum free dye-sensitized-solar-cell counter electrodes.

    Science.gov (United States)

    Kitamura, Koji; Shiratori, Seimei

    2011-05-13

    A thin film of poly(3,4-ethylenedioxythiophene)-poly(4-styrenesulfonic acid) (PEDOT-PSS), which is an alternative cathodic catalyst for Pt in dye-sensitized solar cells, was prepared using the layer-by-layer self-assembly method (LbL). The film is highly adhesive to the substrate and has a controllable thickness. Therefore, the PEDOT-PSS film prepared using LbL is expected have high performance and durability as a counter electrode. Moreover, when carbon black was added to the PEDOT-PSS solution, highly mesoporous PEDOT-PSS and carbon black hybrid films were obtained. These films showed high cathodic activity. In this study, we investigated the change in morphology in the obtained film with increasing carbon black content, and the influence of the porosity and thickness on the performance of the cells. In this study, a Pt-free counter electrode with performance similar to that of Pt-based counter electrodes was successfully fabricated. The achieved efficiency of 4.71% was only a factor of 8% lower than that of the cell using conventional thermally deposited Pt on fluorine-doped tin oxide glass counter electrodes.

  7. Microwave synthesis of electrode materials for lithium batteries

    Indian Academy of Sciences (India)

    M Harish Bhat; B P Chakravarthy; P A Ramakrishnan; A Levasseur; K J RAO

    2000-12-01

    A novel microwave method is described for the preparation of electrode materials required for lithium batteries. The method is simple, fast and carried out in most cases with the same starting material as in conventional methods. Good crystallinity has been noted and lower temperatures of reaction has been inferred in cases where low temperature products have been identified.

  8. A low-cost bio-inspired integrated carbon counter electrode for high conversion efficiency dye-sensitized solar cells.

    Science.gov (United States)

    Wang, Chunlei; Meng, Fanning; Wu, Mingxing; Lin, Xiao; Wang, Tonghua; Qiu, Jieshan; Ma, Tingli

    2013-09-14

    A novel bio-inspired Pt- and FTO-free integrated pure carbon counter electrode (CE) for dye-sensitized solar cells (DSSCs) has been designed and fabricated using a porous carbon sheet as a conducting substrate and ordered mesoporous carbon (OMC) as the catalytic layer. A rigid, crustose lichen-like, integrated carbon-carbon composite architecture with a catalytic layer rooted in a porous conducting substrate was formed by a process of polymer precursor spin coating, infiltration and pyrolysis. The integrated pure carbon CE shows very low series resistance (R(s)), owing to the high conductivity of the carbon sheet (sheet resistance of 488 mΩ □(-1)) and low charge-transfer resistance (R(ct)), due to the large specific surface area of the OMC layer that is accessible to the redox couple. The values of R(s) and R(ct) are much lower than those of a platinized fluorine-doped thin oxide glass (Pt/FTO) electrode. Cells with this CE show high solar-to-electricity conversion efficiencies (8.11%), comparable to that of Pt/FTO based devices (8.16%).

  9. An Efficient Metal-Free Hydrophilic Carbon as a Counter Electrode for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Mojgan Kouhnavard

    2016-01-01

    Full Text Available This study presents a new cost-effective metal-free counter electrode (CE for dye-sensitized solar cells (DSSCs. CE was prepared by doctor blading a hydrophilic carbon (HC particle on a fluorine-doped tin oxide substrate. Thereafter, HC CE was characterized using X-ray diffraction, profilometry, four-point probe testing, and cyclic voltammetry. A 2 µm thick HC CE revealed a comparable catalytic activity to that of the Pt electrode under the same experimental conditions. DSSC based on HC CE was analyzed and showed Jsc of 6.87 mA/cm2 close to that of DSSC with Pt CE (7.0 mA/cm2. More importantly, DSSC based on HC CE yielded a power conversion efficiency (η of 2.93% under AM 1.5 irradiation (100 mW/cm2, which was comparable to that of DSSC based on standard Pt CE. These findings suggest that HC CE could be a promising CE for low-cost DSSCs.

  10. Counter electrodes from polymorphic platinum-nickel hollow alloys for high-efficiency dye-sensitized solar cells

    Science.gov (United States)

    Wang, Jing; Tang, Qunwei; He, Benlin; Yang, Peizhi

    2016-10-01

    Precious platinum counter electrode (CE) has been an economic burden for future commercialization of dye-sensitized solar cells (DSSCs). Low-platinum alloy CE catalysts are promising in bringing down the solar cell cost without reducing photovoltaic performances. We present here a facile strategy of fabricating ZnO nanorods assisted platinum-nickel (PtNi) alloy microtube CEs for liquid-junction DSSCs. By adjusting the concentration of zinc precursors, the ZnO nanostructures and therefore PtNi alloys are optimized to maximize the electrocatalytic behaviors toward triiodide reduction reaction. The maximal power conversion efficiency is determined as high as 8.43% for liquid-junction DSSC device with alloyed PtNi microtube CE synthesized at 75 mM Zn(NO3)2 aqueous solution, yielding a 32.8% enhancement in cell efficiency in comparison with the solar cell from pristine platinum electrode. Moreover, the dissolution resistance and charge-transfer ability toward redox couples have also been markedly enhanced due to competitive dissolution reactions and alloyed effects.

  11. Coaxial fiber supercapacitor using all-carbon material electrodes.

    Science.gov (United States)

    Le, Viet Thong; Kim, Heetae; Ghosh, Arunabha; Kim, Jaesu; Chang, Jian; Vu, Quoc An; Pham, Duy Tho; Lee, Ju-Hyuck; Kim, Sang-Woo; Lee, Young Hee

    2013-07-23

    We report a coaxial fiber supercapacitor, which consists of carbon microfiber bundles coated with multiwalled carbon nanotubes as a core electrode and carbon nanofiber paper as an outer electrode. The ratio of electrode volumes was determined by a half-cell test of each electrode. The capacitance reached 6.3 mF cm(-1) (86.8 mF cm(-2)) at a core electrode diameter of 230 μm and the measured energy density was 0.7 μWh cm(-1) (9.8 μWh cm(-2)) at a power density of 13.7 μW cm(-1) (189.4 μW cm(-2)), which were much higher than the previous reports. The change in the cyclic voltammetry characteristics was negligible at 180° bending, with excellent cycling performance. The high capacitance, high energy density, and power density of the coaxial fiber supercapacitor are attributed to not only high effective surface area due to its coaxial structure and bundle of the core electrode, but also all-carbon materials electrodes which have high conductivity. Our coaxial fiber supercapacitor can promote the development of textile electronics in near future.

  12. Exploring the main function of reduced graphene oxide nano-flakes in a nickel cobalt sulfide counter electrode for dye-sensitized solar cell

    Science.gov (United States)

    Lu, Man-Ning; Lin, Jeng-Yu; Wei, Tzu-Chien

    2016-11-01

    Addition of carbonaceous materials into transition metal sulfide counter electrode (CE) of a dye-sensitized solar cell (DSSC) is a common method to improve the performance of the CE and consequent photovoltaic performance. This improvement is almost without exception attributed to the improvement of overall conductivity after the carbonaceous material addition; however, the root function of these carbonaceous materials in promoting the solar cell efficiency is seldom discussed. In this study, highly crystallized nickel cobalt sulfide (NCS) micro-particles were mixed with a small portion of home-made reduced graphene oxide (rGO) nano-flakes. This NCS/rGO hybrid is subjected to extensive characterizations including X-ray diffraction, Raman spectroscopy, field emission scanning microscopy and electrochemical impedance spectroscopy. It is found that the rGO acts bi-functionally including a co-catalyst in accelerating the tri-iodide reduction for the main NCS catalysts, conductivity promotor to decrease the series resistance of the CE. Proved by electrochemical impedance spectroscopy, it is confirmed that the decrease in series resistance is less insignificant than that in charge transfer resistance, indicating rGO functions more profoundly as a co-catalyst than as a conductivity promotor. Moreover, an argument to highlight the requirement of a CE in a dim-light optimized DSSC is also proposed.

  13. Sustainable Materials for Sustainable Energy Storage: Organic Na Electrodes.

    Science.gov (United States)

    Oltean, Viorica-Alina; Renault, Stéven; Valvo, Mario; Brandell, Daniel

    2016-03-01

    In this review, we summarize research efforts to realize Na-based organic materials for novel battery chemistries. Na is a more abundant element than Li, thereby contributing to less costly materials with limited to no geopolitical constraints while organic electrode materials harvested from biomass resources provide the possibility of achieving renewable battery components with low environmental impact during processing and recycling. Together, this can form the basis for truly sustainable electrochemical energy storage. We explore the efforts made on electrode materials of organic salts, primarily carbonyl compounds but also Schiff bases, unsaturated compounds, nitroxides and polymers. Moreover, sodiated carbonaceous materials derived from biomasses and waste products are surveyed. As a conclusion to the review, some shortcomings of the currently investigated materials are highlighted together with the major limitations for future development in this field. Finally, routes to move forward in this direction are suggested.

  14. Sustainable Materials for Sustainable Energy Storage: Organic Na Electrodes

    Directory of Open Access Journals (Sweden)

    Viorica-Alina Oltean

    2016-03-01

    Full Text Available In this review, we summarize research efforts to realize Na-based organic materials for novel battery chemistries. Na is a more abundant element than Li, thereby contributing to less costly materials with limited to no geopolitical constraints while organic electrode materials harvested from biomass resources provide the possibility of achieving renewable battery components with low environmental impact during processing and recycling. Together, this can form the basis for truly sustainable electrochemical energy storage. We explore the efforts made on electrode materials of organic salts, primarily carbonyl compounds but also Schiff bases, unsaturated compounds, nitroxides and polymers. Moreover, sodiated carbonaceous materials derived from biomasses and waste products are surveyed. As a conclusion to the review, some shortcomings of the currently investigated materials are highlighted together with the major limitations for future development in this field. Finally, routes to move forward in this direction are suggested.

  15. Amorphous titania/carbon composite electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Vaughey, John T.; Jansen, Andrew; Joyce, Christopher D.

    2017-05-09

    An isolated salt comprising a compound of formula (H.sub.2X)(TiO(Y).sub.2) or a hydrate thereof, wherein X is 1,4-diazabicyclo[2.2.2]octane (DABCO), and Y is oxalate anion (C.sub.2O.sub.4.sup.-2), when heated in an oxygen-containing atmosphere at a temperature in the range of at least about 275.degree. C. to less than about 400.degree. C., decomposes to form an amorphous titania/carbon composite material comprising about 40 to about 50 percent by weight titania and about 50 to about 60 percent by weight of a carbonaceous material coating the titania. Heating the composite material at a temperature of about 400 to 500.degree. C. crystallizes the titania component to anatase. The titania materials of the invention are useful as components of the cathode or anode of a lithium or lithium ion electrochemical cell.

  16. The rise of organic electrode materials for energy storage.

    Science.gov (United States)

    Schon, Tyler B; McAllister, Bryony T; Li, Peng-Fei; Seferos, Dwight S

    2016-11-07

    Organic electrode materials are very attractive for electrochemical energy storage devices because they can be flexible, lightweight, low cost, benign to the environment, and used in a variety of device architectures. They are not mere alternatives to more traditional energy storage materials, rather, they have the potential to lead to disruptive technologies. Although organic electrode materials for energy storage have progressed in recent years, there are still significant challenges to overcome before reaching large-scale commercialization. This review provides an overview of energy storage systems as a whole, the metrics that are used to quantify the performance of electrodes, recent strategies that have been investigated to overcome the challenges associated with organic electrode materials, and the use of computational chemistry to design and study new materials and their properties. Design strategies are examined to overcome issues with capacity/capacitance, device voltage, rate capability, and cycling stability in order to guide future work in the area. The use of low cost materials is highlighted as a direction towards commercial realization.

  17. Polyanion‐Type Electrode Materials for Sodium‐Ion Batteries

    Science.gov (United States)

    Ni, Qiao; Wu, Feng

    2017-01-01

    Sodium‐ion batteries, representative members of the post‐lithium‐battery club, are very attractive and promising for large‐scale energy storage applications. The increasing technological improvements in sodium‐ion batteries (Na‐ion batteries) are being driven by the demand for Na‐based electrode materials that are resource‐abundant, cost‐effective, and long lasting. Polyanion‐type compounds are among the most promising electrode materials for Na‐ion batteries due to their stability, safety, and suitable operating voltages. The most representative polyanion‐type electrode materials are Na3V2(PO4)3 and NaTi2(PO4)3 for Na‐based cathode and anode materials, respectively. Both show superior electrochemical properties and attractive prospects in terms of their development and application in Na‐ion batteries. Carbonophosphate Na3MnCO3PO4 and amorphous FePO4 have also recently emerged and are contributing to further developing the research scope of polyanion‐type Na‐ion batteries. However, the typical low conductivity and relatively low capacity performance of such materials still restrict their development. This paper presents a brief review of the research progress of polyanion‐type electrode materials for Na‐ion batteries, summarizing recent accomplishments, highlighting emerging strategies, and discussing the remaining challenges of such systems. PMID:28331782

  18. In situ synthesis of binary cobalt-ruthenium nanofiber alloy counter electrode for electrolyte-free cadmium sulfide quantum dot solar cells

    Science.gov (United States)

    Du, Nan; Ren, Lei; Sun, Weifu; Jin, Xiao; Zhao, Qing; Cheng, Yuanyuan; Wei, Taihuei; Li, Qinghua

    2015-06-01

    A facile, low-cost and low-temperature fabrication approach of counter electrode is essential for pursuing robust photovoltaic devices. Herein, we develop a hydrothermal in situ growth of Cobalt-Ruthenium (Co-Ru) alloy nanofiber electrode for quantum dot solar cell (QDSC) applications. Colloidal CdS QDs with tunable absorption band edge are synthesized and used as light absorber. After optimizing the QDs with the highest photoluminescence quantum yield accompanied by considerable solar light absorption ability, QDSC based on Co-Ru alloy electrode delivers a much higher power conversion efficiency than its counterparts, i.e., either pure Co or Ru metal electrodes. In detail, Co-Ru alloy electrode exhibits high specific area, excellent electrical behavior, intimate interface contact, and good stability, thus leading to notable improved device performances. The impressive robust function of Co-Ru alloy with simple manufacturing procedure highlights its potential applications in robust QDSCs.

  19. Nanostructured Ion Storage Electrode Materials for Lithium Batteries and Supercapacitors

    Institute of Scientific and Technical Information of China (English)

    S.R.S.Prabaharan

    2007-01-01

    1 Results Performance of lithium-ion batteries, electrochemical capacitors, and other electric-energy storage devices is not only determined simply by macroscopic chemical composition of their electrode, but also strongly affected by shape and size of the active materials. Nanostructured materials are distinguished from conventional polycrystalline materials by the nanometer size of the structural units that compose them, and they often exhibit properties that are drastically different from the conventi...

  20. Functional materials in amperometric sensing polymeric, inorganic, and nanocomposite materials for modified electrodes

    CERN Document Server

    Seeber, Renato; Zanardi, Chiara

    2014-01-01

    Amperometric sensors, biosensors included, particularly rely on suitable electrode materials. Progress in material science has led to a wide variety of options that are available today. For the first time, these novel functional electrode coating materials are reviewed in this monograph, written by and for electroanalytical chemists. This includes intrinsically conducting, redox and ion-exchange polymers, metal and carbon nanostructures, silica based materials. Monolayers and relatively thick films are considered. The authors critically discuss preparation methods, in addition to chemical and

  1. New Materials for Oxygen Reduction Electrodes

    DEFF Research Database (Denmark)

    Johansson, Tobias Peter

    This thesis is concerned with the discovery, characterisation and testing of new catalysts for the oxygen reduction reaction (ORR). A theroretical screening study was performed, in close collaboration with the theory group at the Center for Atomicscale Materials Design (CAMD), searching for catal......This thesis is concerned with the discovery, characterisation and testing of new catalysts for the oxygen reduction reaction (ORR). A theroretical screening study was performed, in close collaboration with the theory group at the Center for Atomicscale Materials Design (CAMD), searching...... as the sputter cleaned Pt3Sc. The deposition of Y on a Pt(111) crystal was then investigated. It was found that when annealing the crystal above 800 K a Pt overlayer was formed on top of a PtxY structure. Low energy electron diffraction (LEED) was used to probe the ordering of the surface and the LEED patterns...

  2. Extraction of nano-silicon with activated carbons simultaneously from rice husk and their synergistic catalytic effect in counter electrodes of dye-sensitized solar cells

    Science.gov (United States)

    Ahmad, Waqar; Bahrani, Majid Raissan Al; Yang, Zhichun; Khan, Jahangeer; Jing, Wenkui; Jiang, Fan; Chu, Liang; Liu, Nishuang; Li, Luying; Gao, Yihua

    2016-12-01

    The extraction of renewable energy resources particularly from earth abundant materials has always been a matter of significance in industrial products. Herein, we report a novel simultaneous extraction of nano-silicon with activated carbons (nano-Si@ACs) from rice husk (RH) by chemical activation method. As-extracted nano-Si@ACs is then used as an energy harvesting materials in counter electrodes (CEs) of dye-sensitized solar cells (DSSCs). The morphology, structure and texture studies confirm the high surface area, abundant active sites and porous structure of nano-Si@ACs. Electrochemical impedance spectroscopy and cyclic voltammetry analyses reveal that the nano-Si@ACs is highly beneficial for fast I3‑ reduction and superior electrolyte diffusion capability. The nano-Si@ACs CE based DSSC exhibits enhanced power conversion efficiency of (8.01%) in contrast to pristine Pt CE (7.20%). These favorable results highlight the potential application of RH in low-cost, high-efficiency and Pt-free DSSCs.

  3. Electric and electrochemical properties of catalytically active oxygen electrode materials

    NARCIS (Netherlands)

    Burggraaf, A.J.; Dijk, van M.P.; Vries, de K.J.

    1986-01-01

    The electrical conductivity has been investigated of some oxygen ion and mixed conducting materials. Electrodes are prepared from thin sputtered layers of these oxides combined with a small Au or Pt strip. The kinetics of the oxygen reaction has been studied for temperatures of 820–1020 K and PO2 va

  4. Layer-by-Layer Self-Assembled Graphene Multilayers as Pt-Free Alternative Counter Electrodes in Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Rani, Adila; Chung, Kyungwha; Kwon, Jeong; Kim, Sung June; Jang, Yoon Hee; Jang, Yu Jin; Quan, Li Na; Yoon, Minji; Park, Jong Hyeok; Kim, Dong Ha

    2016-05-11

    Low cost, charged, and large scale graphene multilayers fabricated from nitrogen-doped reduced graphene oxide N-rGO(+), nitrogen and sulfur codoped reduced graphene oxide NS-rGO(+), and undoped reduced graphene oxide rGO(-) were applied as alternative counter electrodes in dye-sensitized solar cells (DSSCs). The neat rGO-based counter electrodes were developed via two types of layer-by-layer (LBL) self-assembly (SA) methods: spin coating and spray coating methods. In the spin coating method, two sets of multilayer films were fabricated on poly(diallyldimethylammonium chloride) (PDDA)-coated fluorine-doped tin oxide (FTO) substrates using GO(-) combined with N-GO(+) followed by annealing and denoted as [rGO(-)/N-rGO(+)]n or with NS-GO(+) and denoted as [rGO(-)/NS-rGO(+)]n for counter electrodes in DSSCs. The DSSCs employing new types of counter electrodes exhibited ∼7.0% and ∼6.2% power conversion efficiency (PCE) based on ten bilayers of [rGO(-)/N-rGO(+)]10 and [rGO(-)/NS-rGO(+)]10, respectively. The DSSCs equipped with a blend of one bilayer of [rGO(-):N-rGO(+)] and [rGO(-):NS-rGO(+)] on PDDA-coated FTO substrates were prepared from a spray coating and showed ∼6.4% and ∼5.6% PCE, respectively. Thus, it was demonstrated that a combination of undoped, nitrogen-doped, and nitrogen and sulfur codoped reduced graphene oxides can be considered as potentially powerful Pt-free electrocatalysts and alternative electrodes in conventional photovoltaic devices.

  5. Electrode Materials for Lithium/Sodium-Ion Batteries

    DEFF Research Database (Denmark)

    Shen, Yanbin

    2014-01-01

    Shen systematically investigated the controlled synthesis of electrode materials for lithium/sodium ion batteries. She also investigated their formation mechanisms and structural evolution during the operation of batteries using in situ/operando X-ray diffraction techniques. The research findings...... provide insights into formation mechanisms of Li4Ti5O12 anode material from both hydrothermal and solid-state reaction. The results also contribute to a thorough understanding of the intercalation and decay mechanisms of O3/P2 layered sodium cathode materials in sodium ion batteries.......The synthesis of electrode materials for lithium/sodium ion batteries and their structural stability during lithium/sodium insertion/extraction are the two essential issues that have limited battery application in the fields requiring long cycle life and high safety. During her PhD studies, Yanbin...

  6. Electrode Materials for Lithium/Sodium-Ion Batteries

    DEFF Research Database (Denmark)

    Shen, Yanbin

    2014-01-01

    The synthesis of electrode materials for lithium/sodium ion batteries and their structural stability during lithium/sodium insertion/extraction are the two essential issues that have limited battery application in the fields requiring long cycle life and high safety. During her PhD studies, Yanbin...... Shen systematically investigated the controlled synthesis of electrode materials for lithium/sodium ion batteries. She also investigated their formation mechanisms and structural evolution during the operation of batteries using in situ/operando X-ray diffraction techniques. The research findings...... provide insights into formation mechanisms of Li4Ti5O12 anode material from both hydrothermal and solid-state reaction. The results also contribute to a thorough understanding of the intercalation and decay mechanisms of O3/P2 layered sodium cathode materials in sodium ion batteries....

  7. Multiwalled carbon nanotube coated polyester fabric as textile based flexible counter electrode for dye sensitized solar cell.

    Science.gov (United States)

    Arbab, Alvira Ayoub; Sun, Kyung Chul; Sahito, Iftikhar Ali; Qadir, Muhammad Bilal; Jeong, Sung Hoon

    2015-05-21

    Textile wearable electronics offers the combined advantages of both electronics and textile characteristics. The essential properties of these flexible electronics such as lightweight, stretchable, and wearable power sources are in strong demand. Here, we have developed a facile route to fabricate multi walled carbon nanotube (MWCNT) coated polyester fabric as a flexible counter electrode (CE) for dye sensitized solar cells (DSSCs). A variety of MWCNT and enzymes with different structures were used to generate individual enzyme-dispersed MWCNT (E-MWCNT) suspensions by non-covalent functionalization. A highly concentrated colloidal suspension of E-MWCNT was deposited on polyester fabric via a simple tape casting method using an air drying technique. In view of the E-MWCNT coating, the surface structure is represented by topologically randomly assembled tubular graphene units. This surface morphology has a high density of colloidal edge states and oxygen-containing surface groups which execute multiple catalytic sites for iodide reduction. A highly conductive E-MWCNT coated fabric electrode with a surface resistance of 15 Ω sq(-1) demonstrated 5.69% power conversion efficiency (PCE) when used as a flexible CE for DSSCs. High photo voltaic performance of our suggested system of E-MWCNT fabric-based DSSCs is associated with high sheet conductivity, low charge transfer resistance (RCT), and excellent electro catalytic activity (ECA). Such a conductive fabric demonstrated stable conductivity against bending cycles and strong mechanical adhesion of E-MWCNT on polyester fabric. Moreover, the polyester fabric is hydrophobic and, therefore, has good sealing capacity and retains the polymer gel electrolyte without seepage. This facile E-MWCNT fabric CE configuration provides a concrete fundamental background towards the development of textile-integrated solar cells.

  8. Development of graphite-polymer composites as electrode materials

    Directory of Open Access Journals (Sweden)

    Carolina Maria Fioramonti Calixto

    2007-06-01

    Full Text Available Graphite powder was mixed to polyurethane, silicon rubber and Araldite® (epoxy in order to prepare composite materials to be used in the preparation of electrodes. Results showed that voltammetric response could be obtained when at least 50% of graphite (w.w-1 is present in the material. SEM and thermogravimetry were also used in the characterization of the composites.

  9. Sensor development exploiting graphite-epoxy composite as electrode material

    Science.gov (United States)

    Azevedo, André L. M.; Oliveira, Renato S.; Ponzio, Eduardo A.; Semaan, Felipe S.

    2015-11-01

    This study presents some results regarding the development and characterization of graphite-epoxy composites for use as working electrodes in electroanalysis. Such composites were preliminary assessed by TGA-DTA, AFM, XDR and cyclic voltammetry (CV), standing for a suitable stable and low cost material for electroanalytical purposes. The described material was used, in its best proportion (65% graphite m/m), to build a cell electrochemistry.

  10. Low-Temperature Thermally Reduced Molybdenum Disulfide as a Pt-Free Counter Electrode for Dye-Sensitized Solar Cells

    Science.gov (United States)

    Lin, Che-Hsien; Tsai, Chuen-Horng; Tseng, Fan-Gang; Yu, Yang-Yen; Wu, Hsuan-Chung; Hsieh, Chien-Kuo

    2015-11-01

    A two-dimensional nanostructure of molybdenum disulfide (MoS2) thin film exposed layered nanosheet was prepared by a low-temperature thermally reduced (TR) method on a fluorine-doped tin oxide (FTO) glass substrate as a platinum (Pt)-free and highly electrocatalytic counter electrode (CE) for dye-sensitized solar cells (DSSCs). Thermogravimetric analysis (TGA) results show that the MoS2 sulfidization temperature was approximately 300 °C. X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD) indicate that the stoichiometry and crystallization of MoS2 were more complete at higher temperatures; however, these temperatures reduce the number of edge-plane active sites in the short-range-order nanostructure. Accordingly, the DSSCs with 300 °C annealed TR-MoS2 CE exhibited an excellent photovoltaic conversion efficiency (PCE) of 6.351 %, up to 91.7 % of which is obtained using the conventional TD-Pt CE (PCE = 6.929 %). The temperature of thermal reaction and the molar ratio of reaction precursors were found to significantly influence the resulting stoichiometry and crystallization of MoS2 nanosheets, thus affecting DSSCs' performance.

  11. Highly effective nickel sulfide counter electrode catalyst prepared by optimal hydrothermal treatment for quantum dot-sensitized solar cells

    Science.gov (United States)

    Gopi, Chandu V. V. M.; Srinivasa Rao, S.; Kim, Soo-Kyoung; Punnoose, Dinah; Kim, Hee-Je

    2015-02-01

    Nickel sulfide (NiS) thin film has been deposited on a fluorine-doped tin oxide substrate by a hydrothermal method using 3-mercaptopropionic acid and used as an efficient counter electrode (CE) for polysulfide redox reactions in quantum dot-sensitized solar cells (QDSSCs). NiS has low toxicity and environmental compatibility. In the present study, the size of the NiS nanoparticle increases with the hydrothermal deposition time. The performance of the QDSSCs is examined in detail using polysulfide electrolyte with the NiS CE. A TiO2/CdS/CdSe/ZnS-based QDSSC using the NiS CE shows enhanced photovoltaic performance with a power conversion efficiency (PCE) of 3.03%, which is superior to that of a cell with Pt CE (PCE 2.20%) under one sun illumination (AM 1.5, 100 mW cm-2). The improved photovoltaic performance of the NiS-based QDSSC may be attributed to a low charge transfer resistance (5.08 Ω) for the reduction of polysulfide on the CE, indicating greater electrocatalytic activity of the NiS. Electrochemical impedance spectroscopy, cyclic voltammetry, and Tafel-polarization measurements were used to investigate the electrocatalytic activity of the NiS and Pt CEs.

  12. Enhanced Electrocatalytic Activity by RGO/MWCNTs/NiO Counter Electrode for Dye-sensitized Solar Cells

    Institute of Scientific and Technical Information of China (English)

    Majid Raissan Al-bahrani; Waqar Ahmad; Hadja Fatima Mehnane; Ying Chen; Ze Cheng; Yihua Gao

    2015-01-01

    We applied the reduced graphene oxide/multi-walled carbon nanotubes/nickel oxide (RGO/MWCNTs/NiO) nanocomposite as the counter electrode (CE) in dye-sensitized solar cells (DSSCs) on fluorine-doped tin oxide substrates by blade doctor method. Power conversion efficiency (PCE) of 8.13% was achieved for this DSSCs device, which is higher than that of DSSCs devices using NiO, RGO, and RGO/NiO-CE (PCE=2.71%, PCE=6.77% and PCE=7.63%). Also, the fill factor of the DSSCs devices using the RGO/MWCNTs/NiO-CE was better than that of other CEs. The electron transfer measurement of cyclic voltammetry and electrochemical impedance spectroscopy showed that RGO/MWCNTs/NiO film could provide fast electron transfer between the CE and the electrolyte, and high electrocatalytic activity for the reduction of triiodide in a CE based on RGO/MWCNTs/NiO in a DSSC.

  13. Counter electrode electrocatalysts from one-dimensional coaxial alloy nanowires for efficient dye-sensitized solar cells

    Science.gov (United States)

    Duan, Jialong; Tang, Qunwei; Zhang, Huihui; Meng, Yuanyuan; Yu, Liangmin; Yang, Peizhi

    2016-01-01

    Pursuit of cost-effective counter electrode (CE) electrocatalysts with no sacrifice of photovoltaic performances has been a persistent objective for advanced dye-sensitized solar cell (DSSC) platforms. Here we demonstrate the experimental realization of CE electrocatalysts from Cu@M@Pt (M = Fe, Co, Ni) coaxial alloy nanowires for efficient DSSCs. The reasonable electrocatalytic activity is attributed to work function matching of alloy CEs to potential of I- /I3- and redistribute the electronic structure on the Pt surface. In comparison with 8.48% for the Pt nanotube CE based DSSC, the solar cells yield power conversion efficiencies up to 8.21%, 7.85%, and 7.30% using Cu@Fe@Pt, Cu@Co@Pt, and Cu@Ni@Pt NWs, respectively. This work represents an important step forward, as it demonstrates how to make the CE catalyst active and to accelerate the electron transport from CE to electrolyte for high-efficiency but cost-effective DSSC platforms.

  14. Electrode material comprising graphene-composite materials in a graphite network

    Energy Technology Data Exchange (ETDEWEB)

    Kung, Harold H.; Lee, Jung K.

    2017-08-08

    A durable electrode material suitable for use in Li ion batteries is provided. The material is comprised of a continuous network of graphite regions integrated with, and in good electrical contact with a composite comprising graphene sheets and an electrically active material, such as silicon, wherein the electrically active material is dispersed between, and supported by, the graphene sheets.

  15. Electrode material comprising graphene-composite materials in a graphite network

    Energy Technology Data Exchange (ETDEWEB)

    Kung, Harold H.; Lee, Jung K.

    2014-07-15

    A durable electrode material suitable for use in Li ion batteries is provided. The material is comprised of a continuous network of graphite regions integrated with, and in good electrical contact with a composite comprising graphene sheets and an electrically active material, such as silicon, wherein the electrically active material is dispersed between, and supported by, the graphene sheets.

  16. Understanding electrode materials of rechargeable lithium batteries via DFT calculations

    Institute of Scientific and Technical Information of China (English)

    Tianran Zhang; Daixin Li; Zhanliang Tao; Jun Chenn

    2013-01-01

    Rechargeable lithium batteries have achieved a rapid advancement and commercialization in the past decade owing to their high capacity and high power density. Different functional materials have been put forward progressively, and each possesses distinguishing structural features and electrochemical properties. In virtue of density functional theory (DFT) calculations, we can start from a specific structure to get a deep comprehension and accurate prediction of material properties and reaction mechanisms. In this paper, we review the main progresses obtained by DFT calculations in the electrode materials of rechargeable lithium batteries, aiming at a better understanding of the common electrode materials and gaining insights into the battery performance. The applications of DFT calculations involve in the following points of crystal structure modeling and stability investigations of delithiated and lithiated phases, average lithium intercalation voltage, prediction of charge distributions and band structures, and kinetic studies of lithium ion diffusion processes, which can provide atomic understanding of the capacity, reaction mechanism, rate capacity, and cycling ability. The results obtained from DFT are valuable to reveal the relationship between the structure and the properties, promoting the design of new electrode materials.

  17. Sol-gel derived electrode materials for supercapacitor applications

    Science.gov (United States)

    Lin, Chuan

    1998-12-01

    Electrochemical capacitors have been receiving increasing interest in recent years for use in energy storage systems because of their high energy and power density and long cycle lifes. Possible applications of electrochemical capacitors include high power pulsed lasers, hybrid power system for electric vehicles, etc. In this dissertation, the preparation of electrode materials for use as electrochemical capacitors has been studied using the sol-gel process. The high surface area electrode materials explored in this work include a synthetic carbon xerogel for use in a double-layer capacitor, a cobalt oxide xerogel for use in a pseudocapacitor, and a carbon-ruthenium xerogel composite, which utilizes both double-layer and faradaic capacitances. The preparation conditions of these materials were investigated in detail to maximize the surface area and optimize the pore size so that more energy could be stored while minimizing mass transfer limitations. The microstructures of the materials were also correlated with their performance as electrochemical capacitors to improve their energy and power densities. Finally, an idealistic mathematical model, including both double-layer and faradaic processes, was developed and solved numerically. This model can be used to perform the parametric studies of an electrochemical capacitor so as to gain a better understanding of how the capacitor works and also how to improve cell operations and electrode materials design.

  18. Investigation of electrodeposited cobalt sulphide counter electrodes and their application in next-generation dye sensitized solar cells featuring organic dyes and cobalt-based redox electrolytes

    Science.gov (United States)

    Swami, Sanjay Kumar; Chaturvedi, Neha; Kumar, Anuj; Kapoor, Raman; Dutta, Viresh; Frey, Julien; Moehl, Thomas; Grätzel, Michael; Mathew, Simon; Nazeeruddin, Mohammad Khaja

    2015-02-01

    Cobalt sulphide (CoS) films are potentiodynamically deposited on fluorine-doped tin oxide (FTO) coated glass substrates employing one, three and five sweep cycles (CoS-I, CoS-III and CoS-V respectively). Analysis of the CoS-III film by impedance spectroscopy reveals a lower charge transfer resistance (RCT) than that measured for Pt CE (0.75 Ω cm-2 and 0.85 Ω cm-2, respectively). The CoS films are used as counter electrodes (CE) in dye-sensitized solar cells (DSSCs) featuring the combination of a high absorption coefficient organic dye (C218) and the cobalt-based redox electrolyte [Co(bpy)3]2/3+. DSSCs fabricated with the CoS-III CE yield the highest short-circuit current density (JSC) of 12.84 mA cm-2, open circuit voltage (VOC) of 805 mV and overall power conversion efficiency (PCE) of 6.72% under AM 1.5G illumination (100 mW cm-2). These values are comparable to the performance of an analogous cell fabricated with the Pt CE (PCE = 6.94%). Owing to relative lower cost (due to the inherit earth abundance of Co) and non-toxicity, CoS can be considered as a promising alternative to the more expensive Pt as a CE material for next-generation DSSCs that utilize organic dyes and cobalt-based redox electrolytes.

  19. Economical low-light photovoltaics by using the Pt-free dye-sensitized solar cell with graphene dot/PEDOT:PSS counter electrodes

    KAUST Repository

    Lee, Chuan Pei

    2015-10-23

    Graphene dots (GDs) are used for enhancing the performance of the poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS)-based counter electrodes in Pt-free dye-sensitized solar cells (DSSCs). As compared to PEDOT:PSS CEs, GD-PEDOT:PSS films possess a rough surface morphology, high conductivity and electrocatalytic activity, and low charge-transfer resistance toward I/I redox reaction, pushing cell efficiency to 7.36%, which is 43% higher than that of the cell with PEDOT:PSS CEs (5.14%). Without much impact on efficiency, the DSSCs with GD-PEDOT:PSS CEs work well under low-light conditions (light intensity <13.5mWcm and angle of incidence >60°), such as indoor and low-level outdoor lighting and of the sun while the other traditional cells would fail to work. The concurrent advantage in low cost in Pt-free materials, simple fabrication processes, comparable efficiency with Pt CEs, and high performance under low-light conditions makes the DSSC with GD-PEDOT:PSS CEs suitable to harvest light for a diverse range of indoor and low-level outdoor lighting locations.

  20. Preparation of Carbon Nanotube/TiO2 Mesoporous Hybrid Photoanode with Iron Pyrite (FeS2) Thin Films Counter Electrodes for Dye-Sensitized Solar Cell

    Science.gov (United States)

    Kilic, Bayram; Turkdogan, Sunay; Astam, Aykut; Ozer, Oguz Can; Asgin, Mansur; Cebeci, Hulya; Urk, Deniz; Mucur, Selin Pravadili

    2016-05-01

    Multi-walled carbon nanotube (MWCNT)/TiO2 mesoporous networks can be employed as a new alternative photoanode in dye-sensitized solar cells (DSSCs). By using the MWCNT/TiO2 mesoporous as photoanodes in DSSC, we demonstrate that the MWCNT/TiO2 mesoporous photoanode is promising alternative to standard FTO/TiO2 mesoporous based DSSC due to larger specific surface area and high electrochemical activity. We also show that iron pyrite (FeS2) thin films can be used as an efficient counter electrode (CE), an alternative to the conventional high cost Pt based CE. We are able to synthesis FeS2 nanostructures utilizing a very cheap and easy hydrothermal growth route. MWCNT/TiO2 mesoporous based DSSCs with FeS2 CE achieved a high solar conversion efficiency of 7.27% under 100 mW cm‑2 (AM 1.5G 1-Sun) simulated solar irradiance which is considerably (slightly) higher than that of A-CNT/TiO2 mesoporous based DSSCs with Pt CE. Outstanding performance of the FeS2 CE makes it a very promising choice among the various CE materials used in the conventional DSSC and it is expected to be used more often to achieve higher photon-to-electron conversion efficiencies.

  1. Hole-Conductor-Free Mesoscopic TiO2/CH3NH3PbI3 Heterojunction Solar Cells Based on Anatase Nanosheets and Carbon Counter Electrodes.

    Science.gov (United States)

    Rong, Yaoguang; Ku, Zhiliang; Mei, Anyi; Liu, Tongfa; Xu, Mi; Ko, Songguk; Li, Xiong; Han, Hongwei

    2014-06-19

    A hole-conductor-free fully printable mesoscopic TiO2/CH3NH3PbI3 heterojunction solar cell was developed with TiO2 nanosheets containing high levels of exposed (001) facets. The solar cell embodiment employed a double layer of mesoporous TiO2 and ZrO2 as a scaffold infiltrated by perovskite as a light harvester. No hole conductor or Au reflector was employed. Instead, the back contact was simply a printable carbon layer. The perovskite was infiltrated from solution through the porous carbon layer. The high reactivity of (001) facets in TiO2 nanosheets improved the interfacial properties between the perovskite and the electron collector. As a result, photoelectric conversion efficiency of up to 10.64% was obtained with the hole-conductor-free fully printable mesoscopic TiO2/CH3NH3PbI3 heterojunction solar cell. The advantages of fully printable technology and the use of low-cost carbon-materials-based counter electrode and hole-conductor-free structure provide this design a promising prospect to approach low-cost photovoltaic devices.

  2. Composite films of metal doped CoS/carbon allotropes; efficient electrocatalyst counter electrodes for high performance quantum dot-sensitized solar cells.

    Science.gov (United States)

    Khalili, Seyede Sara; Dehghani, Hossein; Afrooz, Malihe

    2017-05-01

    This study reports the enhanced catalytic ability of metal ions-doped CoS and CoS/carbon allotrope counter electrodes (CEs) (synthesized using a successive ionic layer adsorption and reaction (SILAR) method) to improve the power conversion efficiency (η) in quantum dot-sensitized solar cells (QDSSCs). Firstly, doping effects of different metal ions (Mg(2+), Ca(2+), Sr(2+) and Ba(2+)) in the CoS CE on the QDSSCs performance have been investigated. Overall, among the different metal doped CoS CEs, the best energy conversion efficiency of 2.19%, achieved for Sr, is the highest reported for QDSSCs constructed with metal doped CoS. A sandwich structural Sr- and Ba-CoS/carbon allotrope (graphene sheet (GS), graphene oxide (GO) and carbon nanotube (CNT)) composite CEs have been prepared by repeating electrophoretic deposition (EPD) of carbon materials and deposition of CoS nanoparticles. Dramatic enhancements of η have been observed with the Sr- and Ba-CoS/GO CEs based QDSSCs (∼76% and ∼41%, respectively), which is higher than that of the bare CoS CE. Because of the large specific surface area and superior electrical conductivity of GS, GO and CNT and the high electrocatalytic activity of CoS, these CEs show an improvement in the photocurrent density in the cells, as revealed from electrochemical and spectral data.

  3. Rapid sintering of MoS2 counter electrode using near-infrared pulsed laser for use in highly efficient dye-sensitized solar cells

    Science.gov (United States)

    Jeong, Hansol; Kim, Jae-Yup; Koo, Bonkee; Son, Hae Jung; Kim, Dongwhan; Ko, Min Jae

    2016-10-01

    Molybdenum disulfide (MoS2) is a promising material for use as a low-cost electrocatalytic counter electrode (CE) in photoelectrochemical dye-sensitized solar cells (DSSCs). However, currently, the MoS2 CEs are generally prepared with a high temperature sintering for the synthesis and crystallization of MoS2. Here, we report a simple and rapid method for the preparation of highly efficient MoS2 CEs. The MoS2 films were synthesized at 70 °C, followed by sintering with a near-infrared (IR) pulsed laser for 1 min. Compared to the conventional heat-sintered MoS2 CE, the laser-sintered CE showed enhanced crystallinity and improved interconnection between the MoS2 particles, resulting in superior electrocatalytic activity towards the I-/I3- redox couple. When used in a DSSC, the laser-sintered MoS2 CE exhibited a higher conversion efficiency (η = 7.19%) compared to that of the heat-sintered CE (η = 5.96%). Furthermore, the laser-sintered CE had a comparable conversion efficiency compared to that of the conventional Pt CE (η = 7.42%).

  4. Photovoltaic performances of Cu2-xTe sensitizer based on undoped and indium(3+)-doped TiO2 photoelectrodes and assembled counter electrodes.

    Science.gov (United States)

    Srathongluan, Pornpimol; Kuhamaneechot, Rattanakorn; Sukthao, Prapatsawan; Vailikhit, Veeramol; Choopun, Supab; Tubtimtae, Auttasit

    2016-02-01

    Novel binary Cu2-xTe nanoparticles based on undoped and indium-doped TiO2 photoelectrodes were synthesized using a successive ionic layer adsorption and reaction (SILAR) technique as a sensitizer for liquid-junction solar cells. A larger diameter of TiO2 promoted a narrower energy band gap after indium doping, attributing to yield a broader absorption range of nanoparticle sensitizer due to the increasing amount of Cu2-xTe NPs on TiO2 surface. The atomic percentages showed the stoichiometric formation of Cu2Te incorporated in a Cu2-xTe structure. The best photovoltaic performance with the lower SILAR cycle, i.e., n=13 was performed after indium doping in both of carbon and Cu2S CEs and revealed that the efficiency of 0.73% under the radiant 100mW/cm(2) (AM 1.5G). The electrochemical impedance spectroscopy (EIS) was used to investigate the electrical properties via effect of material doping and counter electrodes with a lower charge-transfer resistance (Rct) and it was also found that the electron lifetime was improved after the sample doped with indium and assembled with carbon CE.

  5. High performance lithium insertion negative electrode materials for electrochemical devices

    Energy Technology Data Exchange (ETDEWEB)

    Channu, V.S. Reddy, E-mail: chinares02@gmail.com [SMC Corporation, College Station, TX 77845 (United States); Rambabu, B. [Solid State Ionics and Surface Sciences Lab, Department of Physics, Southern University and A& M College, Baton Rouge, LA 70813 (United States); Kumari, Kusum [Department of Physics, National Institute of Technology, Warangal (India); Kalluru, Rajmohan R. [The University of Southern Mississippi, College of Science and Technology, 730 E Beach Blvd, Long Beach, MS 39560 (United States); Holze, Rudolf [Institut für Chemie, AG Elektrochemie, Technische Universität Chemnitz, D-09107 Chemnitz (Germany)

    2016-11-30

    Highlights: • LiCrTiO{sub 4} nanostructures were synthesized for electrochemical applications by soft chemical synthesis followed by annealing. • The presence of Cr and Ti elements are confirmed from the EDS spectrum. • Oxalic acid assisted LiCrTiO{sub 4} electrode shows higher specific capacity (mAh/g). - Abstract: Spinel LiCrTiO{sub 4} oxides to be used as electrode materials for a lithium ion battery and an asymmetric supercapacitor were synthesized using a soft-chemical method with and without chelating agents followed by calcination at 700 °C for 10 h. Structural and morphological properties were studied with powder X-ray diffraction, scanning electron and transmission electron microscopy. Particles of 50–10 nm in size are observed in the microscopic images. The presence of Cr and Ti is confirmed from the EDS spectrum. Electrochemical properties of LiCrTiO{sub 4} electrode were examined in a lithium ion battery. The electrode prepared with oxalic acid-assisted LiCrTiO{sub 4} shows higher specific capacity.This LiCrTiO{sub 4} is also used as anode material for an asymmetric hybrid supercapacitor. The cell exhibits a specific capacity of 65 mAh/g at 1 mA/cm{sup 2}. The specific capacity decreases with increasing current densities.

  6. Highly efficient Mo2C nanotubes as a counter electrode catalyst for organic redox shuttles in dye-sensitized solar cells.

    Science.gov (United States)

    Wu, Mingxing; Lin, Ya-nan; Guo, Hongyue; Wu, Kezhong; Lin, Xiao

    2014-07-21

    Molybdenum carbide nanotubes (Mo2C-NTs) were synthesized and showed remarkable catalytic activity for regeneration of an organic sulfide redox shuttle. The dye-sensitized solar cells (DSCs) using Mo2C-NTs as the counter electrode (CE) showed a high power conversion efficiency of 6.22%, which is much higher than the DSCs using a conventional Pt CE (3.91%).

  7. Porous, single crystalline titanium nitride nanoplates grown on carbon fibers: excellent counter electrodes for low-cost, high performance, fiber-shaped dye-sensitized solar cells.

    Science.gov (United States)

    Chen, Liang; Dai, Hui; Zhou, Yong; Hu, Yingjie; Yu, Tao; Liu, Jianguo; Zou, Zhigang

    2014-11-28

    An excellent, platinum free fiber counter electrode (CE) was successfully fabricated, consisting of porous, single crystalline titanium nitride (TiN) nanoplates grown on carbon fibers (CF). The fiber-shaped dye-sensitized solar cells (FDSSCs) based on the TiN-CF CE show a high conversion efficiency of 7.20%, comparable or even superior to that of the Pt wire (6.23%).

  8. Successive ionic layer adsorption and reaction deposited kesterite Cu{sub 2}ZnSnS{sub 4} nanoflakes counter electrodes for efficient dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mali, Sawanta S.; Shim, Chang Su; Hong, Chang Kook, E-mail: hongck@chonnam.ac.kr

    2014-11-15

    Highlights: • Cu{sub 2}ZnSnS{sub 4} nanoflakes by SILAR technique. • Hydrothermal synthesis of TiO{sub 2}. • Counter electrode for DSSC application. • 4.48% conversion efficiency. - Abstract: In this investigation, we have successfully synthesized Cu{sub 2}ZnSnS{sub 4} (CZTS) nanoflakes by successive ionic layer adsorption and reaction (SILAR) method and used as a counter electrode in the hydrothermally grown TiO{sub 2} based dye sensitized solar cells (DSSCs). The prepared CZTS nanoflakes were characterized using X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), micro Raman spectroscopy and energy dispersive analysis. Our DSSCs results revealed that, compared with conventional Pt/FTO counter electrode DSSCs, nanoflakes of p-type CZTS as the photocathode and n-type TiO{sub 2} thin films as the photoanode shows an increased short circuit current (13.35 mA/cm{sup 2}) with 4.84% power conversion efficiency. The detailed interface properties of were analyzed by electrochemical impedance spectroscopy (EIS) measurements.

  9. Flower-like nickel cobalt sulfide microspheres modified with nickel sulfide as Pt-free counter electrode for dye-sensitized solar cells

    Science.gov (United States)

    Huo, Jinghao; Wu, Jihuai; Zheng, Min; Tu, Yongguang; Lan, Zhang

    2016-02-01

    The nickel cobalt sulfide/nickel sulfide (NiCo2S4/NiS) microspheres which exhibit flower-like morphologies are synthesized by a two-step hydrothermal method. Then the NiCo2S4/NiS microspheres are deposited on a fluorine doped SnO2 substrate by spin-casting the isopropyl alcohol solution of as-prepared microspheres. The cyclic voltammetry, electrochemical impedance spectroscopy and Tafel tests are employed to measure the electrochemical performance of NiCo2S4/NiS counter electrode. The NiCo2S4 and NiS all are used to improve the conductivity and electrocatalytic ability of the films, and the NiS can also increase the specific surface area of microspheres. The dye-sensitized solar cells (DSSCs) with the NiCo2S4/NiS counter electrode exhibite a power conversion efficiency of 8.8%, which is higher than that of DSSC with Pt counter electrode (8.1%) under the light intensity of 100 mW cm-2 (AM 1.5 G).

  10. NiO nanosheet assembles for supercapacitor electrode materials

    Institute of Scientific and Technical Information of China (English)

    Huanhao Xiao; Shunyu Yao; Hongda Liu; Fengyu Qu; Xu Zhang n; Xiang Wu n

    2016-01-01

    In this paper, large scale hierarchically assembled NiO nanosheets have been favorably fabricated through a facile hydrothermal route. The as-prepared NiO nanosheet assembles were characterized in detail by various analytical techniques. The results showed these nanosheets present the thickness of about 30 nm and the surface area is 116.9 m2 g ? 1. These NiO nanosheet assembles were used as the working electrode materials in electrochemical tests, which demonstrated a specific capacitance value of 81.67 F g ? 1 at the current density of 0.5 A g ? 1 and excellent long cycle-life stability with 78.5% of its discharge specific capacitance retention after 3000 cycles at the current density of 0.5 A g?1, revealing the as-synthesized NiO nanosheet assembles might be a promising electrode material for supercapacitor applications.

  11. Enhanced Electrochemical Catalytic Efficiencies of Electrochemically Deposited Platinum Nanocubes as a Counter Electrode for Dye-Sensitized Solar Cells

    Science.gov (United States)

    Wei, Yu-Hsuan; Tsai, Ming-Chi; Ma, Chen-Chi M.; Wu, Hsuan-Chung; Tseng, Fan-Gang; Tsai, Chuen-Horng; Hsieh, Chien-Kuo

    2015-12-01

    Platinum nanocubes (PtNCs) were deposited onto a fluorine-doped tin oxide glass by electrochemical deposition (ECD) method and utilized as a counter electrode (CE) for dye-sensitized solar cells (DSSCs). In this study, we controlled the growth of the crystalline plane to synthesize the single-crystal PtNCs at room temperature. The morphologies and crystalline nanostructure of the ECD PtNCs were examined by field emission scanning electron microscopy and high-resolution transmission electron microscopy. The surface roughness of the ECD PtNCs was examined by atomic force microscopy. The electrochemical properties of the ECD PtNCs were analyzed by cyclic voltammetry, Tafel polarization, and electrochemical impedance spectra. The Pt loading was examined by inductively coupled plasma mass spectrometry. The DSSCs were assembled via an N719 dye-sensitized titanium dioxide working electrode, an iodine-based electrolyte, and a CE. The photoelectric conversion efficiency (PCE) of the DSSCs with the ECD PtNC CE was examined under the illumination of AM 1.5 (100 mWcm-2). The PtNCs in this study presented a single-crystal nanostructure that can raise the electron mobility to let up the charge-transfer impedance and promote the charge-transfer rate. In this work, the electrocatalytic mass activity (MA) of the Pt film and PtNCs was 1.508 and 4.088 mAmg-1, respectively, and the MA of PtNCs was 2.71 times than that of the Pt film. The DSSCs with the pulse-ECD PtNC CE showed a PCE of 6.48 %, which is higher than the cell using the conventional Pt film CE (a PCE of 6.18 %). In contrast to the conventional Pt film CE which is fabricated by electron beam evaporation method, our pulse-ECD PtNCs maximized the Pt catalytic properties as a CE in DSSCs. The results demonstrated that the PtNCs played a good catalyst for iodide/triiodide redox couple reactions in the DSSCs and provided a potential strategy for electrochemical catalytic applications.

  12. Material for electrodes of low temperature plasma generators

    Science.gov (United States)

    Caplan, Malcolm; Vinogradov, Sergel Evge'evich; Ribin, Valeri Vasil'evich; Shekalov, Valentin Ivanovich; Rutberg, Philip Grigor'evich; Safronov, Alexi Anatol'evich

    2008-12-09

    Material for electrodes of low temperature plasma generators. The material contains a porous metal matrix impregnated with a material emitting electrons. The material uses a mixture of copper and iron powders as a porous metal matrix and a Group IIIB metal component such as Y.sub.2O.sub.3 is used as a material emitting electrons at, for example, the proportion of the components, mass %: iron: 3-30; Y.sub.2O.sub.3:0.05-1; copper: the remainder. Copper provides a high level of heat conduction and electric conductance, iron decreases intensity of copper evaporation in the process of plasma creation providing increased strength and lifetime, Y.sub.2O.sub.3 provides decreasing of electronic work function and stability of arc burning. The material can be used for producing the electrodes of low temperature AC plasma generators used for destruction of liquid organic wastes, medical wastes, and municipal wastes as well as for decontamination of low level radioactive waste, the destruction of chemical weapons, warfare toxic agents, etc.

  13. Composite films of carbon black nanoparticles and sulfonated-polythiophene as flexible counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Li, Chun-Ting; Lee, Chi-Ta; Li, Sie-Rong; Lee, Chuan-Pei; Chiu, I.-Ting; Vittal, R.; Wu, Nae-Lih; Sun, Shih-Sheng; Ho, Kuo-Chuan

    2016-01-01

    A composite film based on carbon black nanoparticles and sulfonated-poly(thiophene-3-[2-(2-methoxyethoxy)ethoxy]-2,5-diyl) (CB-NPs/s-PT) is formed on a flexible titanium foil for the use as the electro-catalytic counter electrode (CE) of dye-sensitized solar cells (DSSCs). The CB-NPs provide the large amount of electro-catalytic active sites for the composite film, and the s-PT polymer serves as a conductive binder to enhance the inter-particle linkage among CB-NPs and to improve the adhesion between the composite film and the flexible substrate. The flexible CB-NPs/s-PT composite film is designed to possess good electro-catalytic ability for I-/I3- redox couple by providing large active sites and rapid reduction kinetic rate constant of I3- . The cell with a CB-NPs/s-PT CE exhibits a good cell efficiency (η) of 9.02 ± 0.01% at 100 mW cm-2, while the cell with a platinum CE shows an η of only 8.36 ± 0.02% under the same conditions. At weak light illuminations (20-80 mW cm-2), a DSSC with CB-NPs/s-PT CE still exhibits η's of 7.20 ± 0.04-9.08 ± 0.02%. The low-cost CB-NPs/s-PT CE not only renders high cell efficiency to its DSSC but also shows a great potential to replace the expensive platinum; moreover it is suitable for large-scale production or for indoor applications.

  14. Low-cost solution processed nano millet like structure CoS2 film superior to pt as counter electrode for quantum dot sensitized solar cells

    Science.gov (United States)

    Rao, S. Srinivasa; Punnosse, Dinah; Kim, Soo-Kyoung; Kim, Hee-Je

    2015-05-01

    Cobalt Sulfide (CoS2) counter electrodes (CE) with uniform size distribution were obtained on fluorine-doped tin oxide (FTO) substrate as counter electrodes for polysulfide redox electrolyte in CdS/CdSe/ ZnS quantum dot-sensitized solar cells (QDSSCs) by chemical bath deposition (CBD) technique. In this study, we optimized the cobalt source, deposition temperature and time in the preparation of CoS2 thin film to achieve greater conversion efficiency with strong adhesion on FTO. Relative to the platinum (Pt) electrodes, the CoS2 electrode shows a higher catalytic activity, faster electron transport and lower chargetransfer resistance, which can play a role in rendering higher power conversion efficiency. As a result, QDSSCs with the optimized CoS2 CE achieved a higher short-circuit current density of 13.08 mA cm-2, open-circuit voltage of 0.47 V, fill factor of 0.34 and overall photovoltaic conversion efficiency of 2.17% obtained under one sun illumination (100 mW cm-2). Therefore, CoS2 CE can be used as a promising CE in QDSSCs with efficiency exceeding that of high-cost Pt-based cells (1.64%). [Figure not available: see fulltext.

  15. Thick electrodes including nanoparticles having electroactive materials and methods of making same

    Science.gov (United States)

    Xiao, Jie; Lu, Dongping; Liu, Jun; Zhang, Jiguang; Graff, Gordon L.

    2017-02-21

    Electrodes having nanostructure and/or utilizing nanoparticles of active materials and having high mass loadings of the active materials can be made to be physically robust and free of cracks and pinholes. The electrodes include nanoparticles having electroactive material, which nanoparticles are aggregated with carbon into larger secondary particles. The secondary particles can be bound with a binder to form the electrode.

  16. Thick electrodes including nanoparticles having electroactive materials and methods of making same

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Jie; Lu, Dongping; Liu, Jun; Zhang, Jiguang; Graff, Gordon L.

    2017-02-21

    Electrodes having nanostructure and/or utilizing nanoparticles of active materials and having high mass loadings of the active materials can be made to be physically robust and free of cracks and pinholes. The electrodes include nanoparticles having electroactive material, which nanoparticles are aggregated with carbon into larger secondary particles. The secondary particles can be bound with a binder to form the electrode.

  17. Single-walled Carbon Nanotubes as Electrode Materials for Supercapacitors

    Institute of Scientific and Technical Information of China (English)

    XU Bina; WU Feng; WANG Fang; CHEN Shi; CAO Gao-Ping; YANG Yu-Sheng

    2006-01-01

    Large-scale synthesized single-walled carbon nanotubes (SWNT) prepared by electric arc discharge method and a mixture of NiO and Y2O3 as catalyst have been used as electrode materials for supercapacitors. N2 adsorption/desorption measurement shows that the SWNT is a microporous and mesoporous material with specific surface area 435 m2g1.Thespecific capacitance of the nitric acid treated SWNT in aqueous electrolyte reaches as high as 105 F/g, which is a combination of electric double layer capacitance and pseudocapacitance. The SWNT-based capacitors also have good charge/discharge reversibility and cycling perdurability.

  18. High performance lithium insertion negative electrode materials for electrochemical devices

    Science.gov (United States)

    Channu, V. S. Reddy; Rambabu, B.; Kumari, Kusum; Kalluru, Rajmohan R.; Holze, Rudolf

    2016-11-01

    Spinel LiCrTiO4 oxides to be used as electrode materials for a lithium ion battery and an asymmetric supercapacitor were synthesized using a soft-chemical method with and without chelating agents followed by calcination at 700 °C for 10 h. Structural and morphological properties were studied with powder X-ray diffraction, scanning electron and transmission electron microscopy. Particles of 50-10 nm in size are observed in the microscopic images. The presence of Cr and Ti is confirmed from the EDS spectrum. Electrochemical properties of LiCrTiO4 electrode were examined in a lithium ion battery. The electrode prepared with oxalic acid-assisted LiCrTiO4 shows higher specific capacity.This LiCrTiO4 is also used as anode material for an asymmetric hybrid supercapacitor. The cell exhibits a specific capacity of 65 mAh/g at 1 mA/cm2. The specific capacity decreases with increasing current densities.

  19. Electrochemical Techniques for Intercalation Electrode Materials in Rechargeable Batteries.

    Science.gov (United States)

    Zhu, Yujie; Gao, Tao; Fan, Xiulin; Han, Fudong; Wang, Chunsheng

    2017-03-16

    Understanding of the thermodynamic and kinetic properties of electrode materials is of great importance to develop new materials for high performance rechargeable batteries. Compared with computational understanding of physical and chemical properties of electrode materials, experimental methods provide direct and convenient evaluation of these properties. Often, the information gained from experimental work can not only offer feedback for the computational methods but also provide useful insights for improving the performance of materials. However, accurate experimental quantification of some properties can still be challenging. Among them, chemical diffusion coefficient is one representative example. It is one of the most crucial parameters determining the kinetics of intercalation compounds, which are by far the dominant electrode type used in rechargeable batteries. Therefore, it is of significance to quantitatively evaluate this parameter. For this purpose, various electrochemical techniques have been invented, for example, galvanostatic intermittent titration technique (GITT), potentiostatic intermittent titration technique (PITT), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). One salient advantage of these electrochemical techniques over other characterization techniques is that some implicit thermodynamic and kinetic quantities can be linked with the readily measurable electrical signals, current, and voltage, with very high precision. Nevertheless, proper application of these techniques requires not just an understanding of the structure and chemistry of the studied materials but sufficient knowledge of the physical model for ion transport within solid host materials and the analysis method to solve for chemical diffusion coefficient. Our group has been focusing on using various electrochemical techniques to investigate battery materials, as well as developing models for studying some emerging materials. In this Account, the

  20. Electrochemical pulsed deposition of platinum nanoparticles on indium tin oxide/polyethylene terephthalate as a flexible counter electrode for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Yu-Hsuan; Chen, Chih-Sheng [Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan (China); Ma, Chen-Chi M. [Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Tsai, Chuen-Horng [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Hsieh, Chien-Kuo, E-mail: jack_hsieh@mail.mcut.edu.tw [Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan (China)

    2014-11-03

    In this study, a pulsed-mode electrochemical deposition (Pulse-ECD) technique was employed to deposit platinum nanoparticles (PtNPs) on the indium tin oxide/polyethylene terephthalate (ITO/PET) substrate as a flexible counter electrode for dye-sensitized solar cells (DSSCs). The characteristic properties of the Pulse-ECD PtNPs were prepared and compared to the traditional (electron beam) Pt film. The surface morphologies of the PtNPs were examined by field emission scanning electron microscopy (FE-SEM) and the atomic force microscope (AFM). The FE-SEM results showed that our PtNPs were deposited uniformly on the ITO/PET flexible substrates via the Pulse-ECD technique. The AFM results indicated that the surface roughness of the pulsed PtNPs influenced the power conversion efficiency (PCE) of DSSCs, due to the high specific surface area of PtNPs which enhanced the catalytic activities for the reduction (I{sub 3}{sup −} to I{sup −}) of redox electrolyte. In combination with a N719 dye-sensitized TiO{sub 2} working electrode and an iodine-based electrolyte, the DSSCs with the PtNPs flexible counter electrode showed a PCE of 4.3% under the illumination of AM 1.5 (100 mW cm{sup −2}). The results demonstrated that the Pulse-ECD PtNPs are good candidate for flexible DSSCs. - Highlights: • We used indium tin oxide/polyethylene terephthalate as a flexible substrate. • We utilized pulse electrochemical deposition to deposit platinum nanoparticles. • We synthesized a flexible counter electrode for dye-sensitized solar cell (DSSC). • The power conversion efficiency of DSSC was measured to be 4.3%.

  1. In situ chemical vapor deposition growth of carbon nanotubes on hollow CoFe2O4 as an efficient and low cost counter electrode for dye-sensitized solar cells

    Science.gov (United States)

    Yuan, Hong; Jiao, Qingze; Zhang, Shenli; Zhao, Yun; Wu, Qin; Li, Hansheng

    2016-09-01

    The composites of hollow CoFe2O4 and carbon nanotubes (h-CoFe2O4@CNTs) are successfully prepared by using a simple hydrothermal process coupling with the in-situ chemical vapor deposition (CVD) as electrocatalytic materials for counter electrode of dye-sensitized solar cells. The CNTs are uniformly grown on the surface of hollow CoFe2O4 particles verified by X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) measurements. The electrochemical performances of hollow CoFe2O4@CNTs composites are evaluated by the EIS, Tafel polarization and CV measurements, and exhibiting high electrocatalytic performance for the reduction of triiodide. The presence of conductive polypyrrole nanoparticles could further improve the conductivity and catalytic performance of the resultant composites. Controlling the thickness of composites film, the optimum photovoltaic conversion efficiency of 6.55% is obtained, which is comparable to that of the cells fabricated with Pt counter electrode (6.61%). In addition, the composites exhibit a good long-term electrochemical stability in I3-/I- electrolyte.

  2. A Compton Suppressed Gamma Ray Counter For Radio Assay of Materials

    Science.gov (United States)

    Godfrey, Benjamin

    2016-03-01

    Rare event searches, such as direct dark matter experiments, require materials with ultra-low levels of natural radioactivity. We present a neutron activation analysis (NAA) technique for assaying metals, specifically titanium used for cryostat construction. Earlier attempts at NAA encountered limitations due to bulk activation via (n, p) reactions, which contributed to large continuum backgrounds due to Compton tails. Our method involves a heavy water shielded exposure to minimize (n,p) reactions and a sodium iodide shielded high purity germanium counter for the gamma ray assay. Preliminary results on assays for U/Th/K contamination in titaniumwill be presented.

  3. Alternate electrode materials for the SP100 reactor. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Randich, E.

    1992-05-01

    This work was performed in response to a request by the Astro-Space Division of the General Electric Co. to develop alternate electrodes materials for the electrodes of the PD2 modules to be used in the SP100 thermoelectric power conversion system. Initially, the project consisted of four tasks: (1) development of a ZrB{sub 2} (C) CVD coating on SiMo substrates, (2) development of a ZrB{sub 2} (C) CVD coating on SiGe substrates, (3) development of CVI W for porous graphite electrodes, and (4) technology transfer of pertinent developed processes. The project evolved initially into developing only ZrB{sub 2} coatings on SiGe and graphite substrates, and later into developing ZrB{sub 2} coatings only on graphite substrates. Several sizes of graphite and pyrolytic carbon-coated graphite substrates were coated with ZrB{sub 2} during the project. For budgetary reasons, the project was terminated after half the allotted time had passed. Apart from the production of coated specimens for evaluation, the major accomplishment of the project was the development of the CVD processing to produce the desired coatings.

  4. Nanostructured Mo-based electrode materials for electrochemical energy storage.

    Science.gov (United States)

    Hu, Xianluo; Zhang, Wei; Liu, Xiaoxiao; Mei, Yueni; Huang, Yunhui

    2015-04-21

    The development of advanced energy storage devices is at the forefront of research geared towards a sustainable future. Nanostructured materials are advantageous in offering huge surface to volume ratios, favorable transport features, and attractive physicochemical properties. They have been extensively explored in various fields of energy storage and conversion. This review is focused largely on the recent progress in nanostructured Mo-based electrode materials including molybdenum oxides (MoO(x), 2 ≤ x ≤ 3), dichalconides (MoX2, X = S, Se), and oxysalts for rechargeable lithium/sodium-ion batteries, Mg batteries, and supercapacitors. Mo-based compounds including MoO2, MoO3, MoO(3-y) (0 energy storage systems because of their unique physicochemical properties, such as conductivity, mechanical and thermal stability, and cyclability. In this review, we aim to provide a systematic summary of the synthesis, modification, and electrochemical performance of nanostructured Mo-based compounds, as well as their energy storage applications in lithium/sodium-ion batteries, Mg batteries, and pseudocapacitors. The relationship between nanoarchitectures and electrochemical performances as well as the related charge-storage mechanism is discussed. Moreover, remarks on the challenges and perspectives of Mo-containing compounds for further development in electrochemical energy storage applications are proposed. This review sheds light on the sustainable development of advanced rechargeable batteries and supercapacitors with nanostructured Mo-based electrode materials.

  5. Stimulation and recording electrodes for neural prostheses

    CERN Document Server

    Pour Aryan, Naser; Rothermel, Albrecht

    2015-01-01

    This book provides readers with basic principles of the electrochemistry of the electrodes used in modern, implantable neural prostheses. The authors discuss the boundaries and conditions in which the electrodes continue to function properly for long time spans, which are required when designing neural stimulator devices for long-term in vivo applications. Two kinds of electrode materials, titanium nitride and iridium are discussed extensively, both qualitatively and quantitatively. The influence of the counter electrode on the safety margins and electrode lifetime in a two electrode system is explained. Electrode modeling is handled in a final chapter.

  6. Anodes - Materials for negative electrodes in electrochemical energy technology

    Science.gov (United States)

    Holze, Rudolf

    2014-06-01

    The basic concepts of electrodes and electrochemical cells (including both galvanic and electrolytic ones) are introduced and illustrated with practical examples. Particular attention is paid to negative electrodes in primary and secondary cells, fuel cell electrodes and electrodes in redox flow batteries. General features and arguments pertaining to selection, optimization and further development are highlighted.

  7. NiSe2 as an efficient electrocatalyst for a Pt-free counter electrode of dye-sensitized solar cells.

    Science.gov (United States)

    Gong, Feng; Xu, Xin; Li, Zhuoqun; Zhou, Gang; Wang, Zhong-Sheng

    2013-02-18

    Nickel diselenide (NiSe(2)) has been synthesized and applied as a counter electrode (CE) of dye-sensitized solar cells (DSSCs) for the first time, which displays remarkable catalytic activity in the reduction of I(3)(-). The DSSC with a NiSe(2) CE produces a higher power conversion efficiency (8.69%) than that (8.04%) of the cell with a Pt CE under the same conditions. A new method for comparing the catalytic activity has also been proposed.

  8. Atmospheric Environment Fabrication of Composite Films by Ethanol Catalytic Combustion and Its Use as Counter Electrodes for Dye-Sensitized Soar Cells

    Directory of Open Access Journals (Sweden)

    Xiaoping Zou

    2014-01-01

    Full Text Available The composite films which consist of amorphous carbon, carbon nanotube, and iron nanoparticles were prepared by ethanol catalytic combustion in atmospheric environment. The as-prepared composite films have good electrocatalytic activity and high conductivity which is due to their particular structure. The efficiency of the composite films based dye-sensitized soar cells (DSSCs is closed to that of the Pt based one. Most importantly, the DSSC employing the composite films presents a higher FF than those of Pt based solar cell. In addition, it is a simple method for mass production of composite films counter electrode (CE which is expected to reduce the cost of fabricating DSSCs.

  9. Unique ZnS nanobuns decorated with reduced graphene oxide as an efficient and low-cost counter electrode for dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    Jie Yin; Jie Wang; Huaiyong Li; Huiyan Ma; Wenzhi Li; Xin Shao

    2014-01-01

    Unique ZnS nanobuns decorated with reduced graphene oxide (RGO) was synthesized and found to exhibit a synergetic effect as a highly efficient and low-cost counter electrode (CE) in dye-sensitized solar cells (DSCs). Using this ZnS-RGO CE, a power conversion efficiency (PCE) of 7.03% was achieved. This value was 53% and 41% higher than those of pure ZnS and RGO CEs, respectively. The ZnS-RGO nanocomposite is indeed an efficient and cost-effective Pt-like alternative for iodine reduction reaction.

  10. Improved Positive Electrode Materials for Lithium-ion Batteries

    Science.gov (United States)

    Conry, Thomas Edward

    The introduction of the first commercially produced Li-ion battery by Sony in 1990 sparked a period of unprecedented growth in the consumer electronics industry. Now, with increasing efforts to move away from fossil-fuel-derived energy sources, a substantial amount of current research is focused on the development of an electrified transportation fleet. Unfortunately, existent battery technologies are unable to provide the necessary performance for electric vehicles (EV's) and plug-in hybrid electric vehicles (PHEV's) vehicles at a competitive cost. The cost and performance metrics of current Li-ion batteries are mainly determined by the positive electrode materials. The work here is concerned with understanding the structural and electrochemical consequences of cost-lowering mechanisms in two separate classes of Li-ion cathode materials; the LiMO2 (M = Ni, Mn, Co) layered oxides and the LiMPO4 olivine materials; with the goal of improving performance. Al-substitution for Co in LiNizMnzCo1-2zO 2 ("NMC") materials not only decreases the costly Co-content, but also improves the safety aspects and, notably, enhances the cycling stability of the layered oxide electrodes. The structural and electrochemical effects of Al-substitution are investigated here in a model NMC compound, LiNi0.45 Mn0.45Co0.1-yAlyO2. In addition to electrochemical measurements, various synchrotron-based characterization methods are utilized, including high-resolution X-ray diffraction (XRD), in situ X-ray diffraction, and X-ray absorption spectroscopy (XAS). Al-substitution causes a slight distortion of the as-synthesized hexagonal layered oxide lattice, lowering the inherent octahedral strain within the transition metal layer. The presence of Al also is observed to limit the structural variation of the NMC materials upon Li-deintercalation, as well as extended cycling of the electrodes. Various olivine materials, LiMPO4 ( M=Fe,Co) are produced using a custom-built spray pyrolysis system. Spray

  11. Bi5FeTi3O15 nanofibers/graphene nanocomposites as an effective counter electrode for dye-sensitized solar cells

    Science.gov (United States)

    Zheng, H. W.; Liang, X.; Yu, Y. H.; Wang, K.; Zhang, X. A.; Men, B. Q.; Diao, C. L.; Peng, C. X.; Yue, G. T.

    2017-01-01

    The present study reports Bi5FeTi3O15 (BFTO) nanofibers/graphene (Gr) nanocomposites (BGr) as counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). BFTO nanofibers with diameters of 40-100 nm were fabricated by sol-gel based electrospinning technique. The microstructure and surface morphology of the BFTO nanofibers and the BGr nanocomposites were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The electrochemical performances of BGr CEs were comprehensively characterized and investigated. Compared to pristine BFTO, the nanocomposites have a marked improvement in electrocatalytic performance for the reduction of triiodide because of larger surface area and lower transfer resistance on the electrolyte-electrode interface. The maximum power conversion efficiency has reached 9.56%, which is much larger than that of pure BFTO CEs (0.22%).

  12. The transparent microstrip gas counter

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Hiroyuki, E-mail: leo@q.t.u-tokyo.ac.j [University of Tokyo, Tokyo 113-8656 (Japan); Fujita, Kaoru; Fujiwara, Takeshi [University of Tokyo, Tokyo 113-8656 (Japan); Niko, Hisako; Guerard, Bruno [Institute of Max von Laue and Paul Langevin, BP 156, 38042 Grenoble, Cedex 9 (France); Fraga, Francisco [Departamento de Fisica, LIP-Coimbra, Universidade de Coimbra, 3000 Coimbra (Portugal); Iyomoto, Naoko [University of Tokyo, Tokyo 113-8656 (Japan)

    2010-11-01

    Conventional MSGCs are made of metal electrodes that might absorb or reflect optical photons. If the electrodes are made of transparent material like ITO, we could take advantage of optical readout. A gas scintillation proportional counter made of ITO MSGC is fabricated and tested where both optical and charge signals are obtained. We have selected a multi-grid structure that can avoid charge-up problem with normal transparent glass substrate. Test results with Ar and CF{sub 4} gas mixture showed a stable gas gain of {approx}2800 and {approx}110 optical photons for 6 keV X-rays. Position sensing with PSPMT has successfully been demonstrated.

  13. Quantum dot-sensitized solar cells having 3D-TiO2 flower-like structures on the surface of titania nanorods with CuS counter electrode

    Science.gov (United States)

    Buatong, Nattha; Tang, I.-Ming; Pon-On, Weeraphat

    2015-03-01

    The photovoltaic performance of a quantum dot (QD)-sensitized solar cell consisting of CdS/CdSe/ZnS QDs loaded onto the surface of the three-dimensional (3D) flower-like TiO2 structure grown on an array (1D) of TiO2 nanorods (FTiR) is studied. The flower-like structure on the rod-shaped titania was synthesized using a double-step hydrothermal process. The FTiR array exhibited a 3D/1D composite structure with a specific surface area of 81.87 m2/g. Using CuS as the counter electrode instead of Pt offers the best performance and leads to an increase in the conversion efficiency ( η). The efficiency of the CdS/CdSe/ZnS QD-loaded FTiR assembling CuS counter electrode cell improved from η = 2.715% ( Voc = 0.692 V, Jsc = 5.896 mA/cm2, FF = 0.665) to η = 0.703% ( Voc = 0.665 V, Jsc = 2.108 mA/cm2, FF = 0.501) for the QD-loaded FTiR assembling Pt counter electrode cell. These studies reveal a synergistically beneficial effect on the solar-to-current conversion of these QD-sensitized solar cells when a CuS counter electrode is used instead of the usual Pt counter electrode.

  14. Surface modifications of electrode materials for lithium ion batteries

    Science.gov (United States)

    Fu, L. J.; Liu, H.; Li, C.; Wu, Y. P.; Rahm, E.; Holze, R.; Wu, H. Q.

    2006-02-01

    Since the birth of the lithium ion battery in the early 1990s, its development has been very rapid and it has been widely applied as power source for a lot of light and high value electronics due to its significant advantages over traditional rechargeable battery systems. Recent research demonstrates the importance of surface structural features of electrode materials for their electrochemical performance, and in this paper the latest progress on this aspect is reviewed. Electrode materials are either anodic or cathodic ones. The former mainly include graphitic carbons, whose surfaces can be modified by mild oxidation, deposition of metals and metal oxides, coating with polymers and other kinds of carbons. Through these modifications, the surface structures of the graphitic carbon anodes are improved, and these improvements include: (1) smoothing the active edge surfaces by removing some reactive sites and/or defects on the graphite surface, (2) forming a dense oxide layer on the graphite surface, and (3) covering active edge structures on the graphite surface. Meanwhile, other accompanying changes occur: (1) production of nanochannels/micropores, (2) an increase in the electronic conductivity, (3) an inhibition of structural changes during cycling, (4) a reduction of the thickness of the SEI (solid-electrolyte-interface) layer, and (5) an increase in the number of host sites for lithium storage. As a result, the direct contact of graphite with the electrolyte solution is prevented, its surface reactivity with electrolytes, the decomposition of electrolytes, the co-intercalation of the solvated lithium ions and the charge-transfer resistance are decreased, and the movement of graphene sheets is inhibited. When the surfaces of cathode materials, mainly including LiCoO 2, LiNiO 2 and LiMn 2O 4, are coated with oxides such as MgO, Al 2O 3, ZnO, SnO 2, ZrO 2, Li 2Oṡ2B 2O 3 glass and other electroactive oxides, the coating can prevent their direct contact with the

  15. Platinum-Free Counter Electrode Comprised of Metal-Organic-Framework (MOF)-Derived Cobalt Sulfide Nanoparticles for Efficient Dye-Sensitized Solar Cells (DSSCs)

    Science.gov (United States)

    Hsu, Shao-Hui; Li, Chun-Ting; Chien, Heng-Ta; Salunkhe, Rahul R.; Suzuki, Norihiro; Yamauchi, Yusuke; Ho, Kuo-Chuan; Wu, Kevin C.-W.

    2014-11-01

    We fabricated a highly efficient (with a solar-to-electricity conversion efficiency (η) of 8.1%) Pt-free dye-sensitized solar cell (DSSC). The counter electrode was made of cobalt sulfide (CoS) nanoparticles synthesized via surfactant-assisted preparation of a metal organic framework, ZIF-67, with controllable particle sizes (50 to 320 nm) and subsequent oxidation and sulfide conversion. In contrast to conventional Pt counter electrodes, the synthesized CoS nanoparticles exhibited higher external surface areas and roughness factors, as evidenced by X-ray diffraction (XRD), scanning electron microscopy (SEM) element mapping, and electrochemical analysis. Incident photon-to-current conversion efficiency (IPCE) results showed an increase in the open circuit voltage (VOC) and a decrease in the short-circuit photocurrent density (Jsc) for CoS-based DSSCs compared to Pt-based DSSCs, resulting in a similar power conversion efficiency. The CoS-based DSSC fabricated in the study show great potential for economically friendly production of Pt-free DSSCs.

  16. Well-dispersed CoS nanoparticles on a functionalized graphene nanosheet surface: a counter electrode of dye-sensitized solar cells.

    Science.gov (United States)

    Miao, Xiaohuan; Pan, Kai; Wang, Guofeng; Liao, Yongping; Wang, Lei; Zhou, Wei; Jiang, Baojiang; Pan, Qingjiang; Tian, Guohui

    2014-01-07

    With a facile electrophoretic deposition and chemical bath process, CoS nanoparticles have been uniformly dispersed on the surface of the functionalized graphene nanosheets (FGNS). The composite was employed as a counter electrode of dye-sensitized solar cells (DSSCs), which yielded a power conversion efficiency of 5.54 %. It is found that this efficiency is higher than those of DSSCs based on the non-uniform CoS nanoparticles on FGNS (4.45 %) and built on the naked CoS nanoparticles (4.79 %). The achieved efficiency of our cost-effective DSSC is also comparable to that of noble metal Pt-based DSSC (5.90 %). Our studies have revealed that both the exceptional electrical conductivity of the FGNS and the excellent catalytic activity of the CoS nanoparticles improve the conversion efficiency of the uniformly FGNS-CoS composite counter electrode. The electrochemical impedance spectra, cyclic voltammetry, and Tafel polarization have evidenced the best catalytic activity and the fastest electron transport. Additionally, the dispersion condition of CoS nanoparticles on FGNS plays an important role for catalytic reduction of I3 (-) .

  17. Atmospheric-Pressure Plasma Jet Processed Pt-Decorated Reduced Graphene Oxides for Counter-Electrodes of Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Ting-Hao Wan

    2016-10-01

    Full Text Available Ultrafast atmospheric-pressure plasma jet (APPJ processed Pt-decorated reduced graphene oxides (rGOs were used as counter-electrodes in dye-sensitized solar cells (DSSCs. Pastes containing rGO, ethyl cellulose, terpineol, and chloroplatinic acid were screen-printed and sintered by nitrogen dc-pulse APPJs. Pt nanodots were uniformly distributed on the rGO flakes. When using Pt-decorated rGOs as the counter electrodes of DSSCs, the efficiency of the DSSC first increased and then decreased as the APPJ processing time increased. Nitrogen APPJs can effectively remove organic binders and can reduce chloroplatinic acid to Pt, thereby improving the efficiency of DSSCs. However, over-calcination by APPJ can damage the graphenes and degrade the DSSCs. The addition of Pt mainly improves the fill factor, which thereby increases the efficiency of DSSCs. The optimized APPJ processing time was merely 9 s owing to the vigorous interaction among the rGOs, chloroplatinic acid and nitrogen APPJs.

  18. production of manual arc welding electrodes with local raw materials

    African Journals Online (AJOL)

    CHUKSSUCCESS 4 LOVE

    effectively with titanium dioxide based electrode (a foreign electrode) with tensile strength of. 606.7N/mm . ... composition and mechanical properties as ... bead from oxidation during welding. ... Manganese (Mn), Slag, Silicon (Si) and Iron. 2. 3.

  19. Work function determination of promising electrode materials for thermionic converters

    Science.gov (United States)

    Jacobson, D.

    1977-01-01

    Work performed on this contract was primarily for the evaluation of selected electrode materials for thermionic energy converters. The original objective was to characterize selected nickel based superalloys up to temperatures of 1400 K. It was found that an early selection, Inconel 800 produced a high vapor pressure which interfered with the vacuum emission measurements. The program then shifted to two other areas. The first area was to obtain emission from the superalloys in a cesiated atmosphere. The cesium plasma helps to suppress the vaporization interference. The second area involved characterization of the Lanthanum-Boron series as thermionic emitters. These final two areas resulted in three journal publications which are attached to this report.

  20. Graphene-based materials for supercapacitor electrodes – A review

    Directory of Open Access Journals (Sweden)

    Qingqing Ke

    2016-03-01

    Full Text Available The graphene-based materials are promising for applications in supercapacitors and other energy storage devices due to the intriguing properties, i.e., highly tunable surface area, outstanding electrical conductivity, good chemical stability and excellent mechanical behavior. This review summarizes recent development on graphene-based materials for supercapacitor electrodes, based on their macrostructural complexity, i.e., zero-dimensional (0D (e.g. free-standing graphene dots and particles, one-dimensional (1D (e.g. fiber-type and yarn-type structures, two-dimensional (2D (e.g. graphenes and graphene-based nanocomposite films, and three-dimensional (3D (e.g. graphene foam and hydrogel-based nanocomposites. There are extensive and on-going researches on the rationalization of their structures at varying scales and dimensions, development of effective and low cost synthesis techniques, design and architecturing of graphene-based materials, as well as clarification of their electrochemical performance. It is indicated that future studies should focus on the overall device performance in energy storage devices and large-scale process in low costs for the promising applications in portable and wearable electronic, transport, electrical and hybrid vehicles.

  1. Electrical and electrochemical properties of carbon counter electrode%碳薄膜对电极的电学与电化学性能研究

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    The influence of mixing amount of carbon black on electrical and electrochemical properties of TiO2/graphite blend film was studied. Morphologies,electrical properties and electrochemical properties of electrodes were characterized by scanning electron microscopy,four probe method and electrochemical impedance spectroscopy,respectively. Photovoltaic performance of the cells was examined. It is found that the sheet resistance of carbon counter electrode decreases by 35% with incorporation of carbon black. When carbon black content is 5%(mass fraction),charge transfer resistance and photovoltaic performance reach the optimum. Photoelectric conversion efficiency reaches 74% of the cells with Pt counter electrode.%  为研究碳黑掺入量对TiO2/石墨共混薄膜的电学与电化学性能的影响,采用场发射扫描电子显微镜、四探针电阻率测试仪、电化学交流阻抗图谱以及太阳能电池综合测试仪对碳薄膜的表面形貌、电学、电化学性质以及电池的光电性能进行表征测试。结果表明:碳黑的加入使碳对电极的方块电阻降低了35%;当掺入质量分数为5%的碳黑时,碳对电极的界面电荷传输电阻及光电性能达到最佳,其光电转换效率可达到Pt对电极的74%。

  2. Cu{sub 2−x}S films as counter-electrodes for dye solar cells with ferrocene-based liquid electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Congiu, M., E-mail: mirko.congiu@fc.unesp.br [UNESP, Univ. Estadual Paulista, POSMAT — Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, Av. Eng. Luiz Edmundo Carrijo Coube14-01, 17033-360 Bauru, SP (Brazil); Nunes-Neto, O. [UNESP, Univ. Estadual Paulista, POSMAT — Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, Av. Eng. Luiz Edmundo Carrijo Coube14-01, 17033-360 Bauru, SP (Brazil); De Marco, M.L.; Dini, D. [University of Rome “La Sapienza”, Department of Chemistry, Piazzale Aldo Moro 5, Rome, RM (Italy); Graeff, C.F.O. [UNESP, Univ. Estadual Paulista, POSMAT — Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, Av. Eng. Luiz Edmundo Carrijo Coube14-01, 17033-360 Bauru, SP (Brazil); DC-FC, UNESP, Univ. Estadual Paulista, Av. Eng. Luiz Edmundo Carrijo Coube14-01, 17033-360 Bauru, SP (Brazil)

    2016-08-01

    In this work, the application of hexagonal CuS nanoparticle layers as counter electrodes for dye sensitized solar cells has been studied. A fast, cheap and reliable deposition method was proposed for the one-step preparation of Cu{sub 2−x}S layers on F-doped SnO{sub 2} within 30 min through an ink-based technique. The electrodes prepared with our method were tested with iodine/iodide electrolyte, Co(II)/(III) bipyridine redox shuttle and Fe(II)/(III) ferrocene-based liquid electrolyte. The Cu{sub 2−x}S layers showed high efficiency and stability with the ferrocene/ferrocenium redox couple, showing a fast charge recombination kinetic, low charge transfer resistance (R{sub ct} = 0.73 Ω cm{sup 2}), reasonably high limiting current (11.8 mA cm{sup −2}) and high stability in propylene carbonate. - Highlights: • We proposed a low-cost Cu{sub 2−x}S electrode for dye solar cells. • Easy deposition and processing • Suitable for large-area applications • Advantages and limitations of Cu{sub 2−x}S with three different redox electrolytes • High electro-catalytic efficiency and stability with the ferrocene/ferrocenium redox couple.

  3. Drop detachment and motion on fuel cell electrode materials.

    Science.gov (United States)

    Gauthier, Eric; Hellstern, Thomas; Kevrekidis, Ioannis G; Benziger, Jay

    2012-02-01

    Liquid water is pushed through flow channels of fuel cells, where one surface is a porous carbon electrode made up of carbon fibers. Water drops grow on the fibrous carbon surface in the gas flow channel. The drops adhere to the superficial fiber surfaces but exhibit little penetration into the voids between the fibers. The fibrous surfaces are hydrophobic, but there is a substantial threshold force necessary to initiate water drop motion. Once the water drops begin to move, however, the adhesive force decreases and drops move with minimal friction, similar to motion on superhydrophobic materials. We report here studies of water wetting and water drop motion on typical porous carbon materials (carbon paper and carbon cloth) employed in fuel cells. The static coefficient of friction on these textured surfaces is comparable to that for smooth Teflon. But the dynamic coefficient of friction is several orders of magnitude smaller on the textured surfaces than on smooth Teflon. Carbon cloth displays a much smaller static contact angle hysteresis than carbon paper due to its two-scale roughness. The dynamic contact angle hysteresis for carbon paper is greatly reduced compared to the static contact angle hysteresis. Enhanced dynamic hydrophobicity is suggested to result from the extent to which a dynamic contact line can track topological heterogeneities of the liquid/solid interface.

  4. Potential electrode materials for symmetrical Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Ruiz Morales, J. C.

    2008-08-01

    Full Text Available Chromites, titanates and Pt-YSZ-CeO2 cermets have been investigated as potential electrode materials for an alternative concept of Solid Oxide Fuel Cell (SOFC, the symmetrical SOFCs (SFC. In this configuration, the same electrode material is used simultaneously as anode and cathode. Interconnector materials, such as chromites, could be considered as potential SFC electrodes, at least under pure hydrogen-fed at relatively high temperatures, as they do not exhibit significant catalytic activity towards hydrocarbon oxidation. This may be overcome by partially substituting Cr in the perovskite B-sites by other transition metal cations such as Mn. La0.75Sr0.25Cr0.5Mn0.5O3-δ (LSCM is a good candidate for such SFCs, rendering fuel cell performances in excess of 500 and 300mW/cm2 using pure H2 and CH4 as fuel, at 950 oC. Similarly, typical n-type electronic conductors traditionally regarded as anode materials, such as strontium titanates, may also operate under oxidising conditions as cathodes by substituting some Ti content for Fe to introduce p-type conductivity. Preliminary electrochemical experiments on La4Sr8Ti12-xFexO38-δ-based SFCs show that they perform reasonably well under humidified H2, at high temperatures. A third group of materials is the support material of any typical cermet anode, i.e. YSZ, CeO2 plus a current collector. It has been found that this combination could be optimised to operate as SFC electrodes, rendering performances of 400mW/cm2 under humidified pure H2 at 950oC.

    Cromitas, titanatos y cermets de Pt-YSZ-CeO2 han sido investigados como potenciales materiales de electrodo para un concepto alternativo de Pilas de Combustible de Óxidos Sólidos (SOFC, las pilas SOFC simétricas (SFC. En

  5. Fabrication of a three-electrode battery using hydrogen-storage materials

    Science.gov (United States)

    Roh, Chi-Woo; Seo, Jung-Yong; Moon, Hyung-Seok; Park, Hyun-Young; Nam, Na-Yun; Cho, Sung Min; Yoo, Pil J.; Chung, Chan-Hwa

    2015-04-01

    In this study, an energy storage device using a three-electrode battery is fabricated. The charging process takes place during electrolysis of the alkaline electrolyte where hydrogen is stored at the palladium bifunctional electrode. Upon discharging, power is generated by operating the alkaline fuel cell using hydrogen which is accumulated in the palladium hydride bifunctional electrode during the charging process. The bifunctional palladium electrode is prepared by electrodeposition using a hydrogen bubble template followed by a galvanic displacement reaction of platinum in order to functionalize the electrode to work not only as a hydrogen storage material but also as an anode in a fuel cell. This bifunctional electrode has a sufficiently high surface area and the platinum catalyst populates at the surface of electrode to operate the fuel cell. The charging and discharging performance of the three-electrode battery are characterized. In addition, the cycle stability is investigated.

  6. Cost-effective counter electrode electrocatalysts from iron@palladium and iron@platinum alloy nanospheres for dye-sensitized solar cells

    Science.gov (United States)

    Tang, Qunwei; Liu, Juan; Zhang, Huihui; He, Benlin; Yu, Liangmin

    2015-11-01

    Pursuit of cost-effective counter electrode (CE) electrocatalysts with no sacrifice of photovoltaic performances has been a persistent objective for dye-sensitized solar cells (DSSCs). Here we demonstrate the galvanic replacement realization of cost-effective CEs from Fe@M (M = Pd, Pt) nanospheres for DSSCs. Due to the enhanced catalytic activity originated from compressive strain and extended surface in tuning the electronic structure of Pd (or Pt) shell along with competitive dissolution reaction of Fe with electrolyte, the cells with high durability display efficiencies of 8.74% and 7.22%. The impressive results along with simple synthesis highlight the potential application of Fe@M nanospheres in robust DSSCs.

  7. Universal low-temperature MWCNT-COOH-based counter electrode and a new thiolate/disulfide electrolyte system for dye-sensitized solar cells.

    Science.gov (United States)

    Hilmi, Abdulla; Shoker, Tharallah A; Ghaddar, Tarek H

    2014-06-11

    A new thiolate/disulfide organic-based electrolyte system composed of the tetrabutylammonium salt of 2-methyl-5-trifluoromethyl-2H-[1,2,4]triazole-3-thiol (S(-)) and its oxidized form 3,3'-dithiobis(2-methyl-5-trifluoromethyl-2H-[1,2,4]triazole) (DS) has been formulated and used in dye-sensitized solar cells (DSSCs). The electrocatalytic activity of different counter electrodes (CEs) has been evaluated by means of measuring J-V curves, cyclic voltammetry, Tafel plots, and electrochemical impedance spectroscopy. A stable and low-temperature CE based on acid-functionalized multiwalled carbon nanotubes (MWCNT-COOH) was investigated with our S(-)/DS, I(-)/I3(-), T(-)/T2, and Co(II/III)-based electrolyte systems. The proposed CE showed superb electrocatalytic activity toward the regeneration of the different electrolytes. In addition, good stability of solar cell devices based on the reported electrolyte and CE was shown.

  8. Comment on "Energy storage via polyvinylidene fluoride dielectric on the counter electrode of dye-sensitized solar cells" by Jiang et al.

    Science.gov (United States)

    Dao, Van-Duong

    2017-01-01

    A recent paper by Jiang et al. [1] provides a modifying of counter electrode (CE) with a poly (vinylidene fluoride) (PVDF) composite could be generated both energy conversion and storage. As the results, the generation of energy storage is due to the high dielectric constant of PVDF layer. Herein, we pointed out the energy storage can be formed with electrolyte consisted of Li+ ions and without using PVDF layer. This study also discusses the formation of energy storage at the CE. The finding in this work may pay the way for further development of an efficient CE for the large-scale applications of dye-sensitized solar cells (DSCs) in the future, and energy storage of DSCs.

  9. Effects of Electrode Material on the Voltage of a Tree-Based Energy Generator.

    Directory of Open Access Journals (Sweden)

    Zhibin Hao

    Full Text Available The voltage between a standing tree and its surrounding soil is regarded as an innovative renewable energy source. This source is expected to provide a new power generation system for the low-power electrical equipment used in forestry. However, the voltage is weak, which has caused great difficulty in application. Consequently, the development of a method to increase the voltage is a key issue that must be addressed in this area of applied research. As the front-end component for energy harvesting, a metal electrode has a material effect on the level and stability of the voltage obtained. This study aimed to preliminarily ascertain the rules and mechanisms that underlie the effects of electrode material on voltage. Electrodes of different materials were used to measure the tree-source voltage, and the data were employed in a comparative analysis. The results indicate that the conductivity of the metal electrode significantly affects the contact resistance of the electrode-soil and electrode-trunk contact surfaces, thereby influencing the voltage level. The metal reactivity of the electrode has no significant effect on the voltage. However, passivation of the electrode materials markedly reduces the voltage. Suitable electrode materials are demonstrated and recommended.

  10. Preparation of Reduced Graphene Oxides as Electrode Materials for Supercapacitors

    KAUST Repository

    Bai, Yaocai

    2012-06-01

    Reduced graphene oxide as outstanding candidate electrode material for supercapacitor has been investigated. This thesis includes two topics. One is that three kinds of reduced graphene oxides were prepared by hydrothermal reduction under different pH conditions. The pH values were found to have great influence on the reduction of graphene oxides. Acidic and neutral media yielded reduced graphene oxides with more oxygen-functional groups, lower specific surface areas but broader pore size distributions than those in basic medium. Variations induced by the pH changes resulted in great differences in the supercapacitor performance. The graphene produced in the basic solution presented mainly electric double layer behavior with specific capacitance of 185 F/g, while the other two showed additional pseudocapacitance behavior with specific capacitance of 225 F/g (acidic) and 230 F/g (neutral), all at a constant current density of 1A/g. The other one is that different reduced graphene oxides were prepared via solution based hydrazine reduction, low temperature thermal reduction, and hydrothermal reduction. The as- prepared samples were then investigated by UV-vis spectroscopy, X-ray diffraction, Raman spectroscopy, and Scanning electron microscope. The supercapacitor performances were also studied and the hydrothermally reduced graphene oxide exhibited the highest specific capacitance.

  11. Metal-free polymer/MWCNT composite fiber as an efficient counter electrode in fiber shape dye-sensitized solar cells

    Science.gov (United States)

    Ali, Abid; Mujtaba Shah, Syed; Bozar, Sinem; Kazici, Mehmet; Keskin, Bahadır; Kaleli, Murat; Akyürekli, Salih; Günes, Serap

    2016-09-01

    Highly aligned multiwall carbon nanotubes (MWCNT) as fiber were modified with a conducting polymer via a simple dip coating method. Modified MWCNT exhibited admirable improvement in electrocatalytic activity for the reduction of tri-iodide in dye sensitized solar cells. Scanning electron microscopy images confirm the successful deposition of polymer on MWCNT. Cyclic voltammetry, square wave voltammetry and electrochemical impedance spectroscopy studies were carried out to investigate the inner mechanism for the charge transfer behaviour. Results from bare and modified electrodes revealed that the MWCNT/(poly (3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) composite electrode is much better at catalysing the {{{{I}}}3}-/{{{I}}}- redox couple compared to the pristine fiber electrode. The photoelectric conversion efficiency of 5.03% for the modified MWCNT electrodes was comparable with that of the conventional Pt-based electrode. The scientific results of this study reveal that MWCNT/PEDOT:PSS may be a better choice for the replacement of cost intensive electrode materials such as platinum. Good performance even after bending up to 90° and in-series connection to enhance the output voltage were also successfully achieved, highlighting the practical application of this novel device.

  12. Recent research progress on iron- and manganese-based positive electrode materials for rechargeable sodium batteries.

    Science.gov (United States)

    Yabuuchi, Naoaki; Komaba, Shinichi

    2014-08-01

    Large-scale high-energy batteries with electrode materials made from the Earth-abundant elements are needed to achieve sustainable energy development. On the basis of material abundance, rechargeable sodium batteries with iron- and manganese-based positive electrode materials are the ideal candidates for large-scale batteries. In this review, iron- and manganese-based electrode materials, oxides, phosphates, fluorides, etc, as positive electrodes for rechargeable sodium batteries are reviewed. Iron and manganese compounds with sodium ions provide high structural flexibility. Two layered polymorphs, O3- and P2-type layered structures, show different electrode performance in Na cells related to the different phase transition and sodium migration processes on sodium extraction/insertion. Similar to layered oxides, iron/manganese phosphates and pyrophosphates also provide the different framework structures, which are used as sodium insertion host materials. Electrode performance and reaction mechanisms of the iron- and manganese-based electrode materials in Na cells are described and the similarities and differences with lithium counterparts are also discussed. Together with these results, the possibility of the high-energy battery system with electrode materials made from only Earth-abundant elements is reviewed.

  13. Nickel Oxide as an Electrode Material for Supercapacitors

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The preparation of Ni oxide films and their capacitive mechanism are discussed in this paper. Nickel oxide film electrodes perform pseudocapacitance in aqueous KOH and NaOH but perform double layer capacitance in LiCIO4/PC (propylence carbonate). The effect of increasing the specific capacitance was observed when Ni oxide film electrodes are doped with Co. A specific capacitance of around 70 F/g was achieved when using Ni oxide films doped with Co as electrodes and 1 mol/L aqueous KOH or NaOH as an electrolyte.

  14. Dye-sensitized solar cell with natural gel polymer electrolytes and f-MWCNT as counter-electrode

    Science.gov (United States)

    Nwanya, A. C.; Amaechi, C. I.; Ekwealor, A. B. C.; Osuji, R. U.; Maaza, M.; Ezema, F. I.

    2015-05-01

    Samples of DSSCs were made with gel polymer electrolytes using agar, gelatin and DNA as the polymer hosts. Anthocyanine dye from Hildegardia barteri flower is used to sensitize the TiO2 electrode, and the spectrum of the dye indicates strong absorptions in the blue region of the solar spectrum. The XRD pattern of the TiO2 shows that the adsorption of the dye did not affect the crystallinity of the electrode. The f-MWCNT indicates graphite structure of the MWCNTs were acid oxidized without significant damage. Efficiencies of 3.38 and 0.1% were obtained using gelatin and DNA gel polymer electrolytes, respectively, for the fabricated dye-sensitized solar cells.

  15. A viable electrode material for use in microbial fuel cells for tropical regions

    DEFF Research Database (Denmark)

    Offei, Felix; Thygesen, Anders; Mensah, Moses

    2016-01-01

    was 0.66 V and 1.74 W/m3, respectively. The power generated by AC was as high as 86% of the value obtained with the extensively used carbon paper. Scanning electron microscopy and Denaturing Gradient Gel Electrophoresis (DGGE) analysis of AC anode biofilms confirmed that electrogenic bacteria were......Electrode materials are critical for microbial fuel cells (MFC) since they influence the construction and operational costs. This study introduces a simple and efficient electrode material in the form of palm kernel shell activated carbon (AC) obtained in tropical regions. The novel introduction...... of this material is also targeted at introducing an inexpensive and durable electrode material, which can be produced in rural communities to improve the viability of MFCs. The maximum voltage and power density obtained (under 1000 Ω load) using an H-shaped MFC with AC as both anode and cathode electrode material...

  16. Light stability tests of CH3NH3PbI3 perovskite solar cells using porous carbon counter electrodes.

    Science.gov (United States)

    Ito, Seigo; Mizuta, Gai; Kanaya, Shusaku; Kanda, Hiroyuki; Nishina, Tomoya; Nakashima, Seiji; Fujisawa, Hironori; Shimizu, Masaru; Haruyama, Yuichi; Nishino, Hitoshi

    2016-10-21

    The CH3NH3PbI3 perovskite solar cells have been fabricated using three-porous-layered electrodes as, 〈glass/F-doped tin oxide (FTO)/dense TiO2/porous TiO2-perovskite/porous ZrO2-perovskite/porous carbon-perovskite〉 for light stability tests. Without encapsulation in air, the CH3NH3PbI3 perovskite solar cells maintained 80% of photoenergy conversion efficiency from the initial value up to 100 h under light irradiation (AM 1.5, 100 mW cm(-2)). Considering the color variation of the CH3NH3PbI3 perovskite layer, the significant improvement of light stability is due to the moisture-blocking effect of the porous carbon back electrodes. The strong interaction between carbon and CH3NH3PbI3 perovskite was proposed by the measurements of X-ray photoelectron spectroscopy and X-ray diffraction of the porous carbon-perovskite layers.

  17. Folded structured graphene paper for high performance electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fei; Song, Shuyan; Xue, Dongfeng; Zhang, Hongjie [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022 (China)

    2012-02-21

    A novel method to fabricate graphene paper with folded structured graphene sheets is described. When used as an electrode for LIBs and supercapacitors, the as-prepared graphene paper can show much higher performances compared to conventional graphene paper fabricated by a flow-directed assembly method. The unique graphene paper obtained here is promising to act as a new kind of flexible electrode for wearable or rolling-up devices. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Thin film lithium-based batteries and electrochromic devices fabricated with nanocomposite electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Gillaspie, Dane T; Lee, Se-Hee; Tracy, C. Edwin; Pitts, John Roland

    2014-02-04

    Thin-film lithium-based batteries and electrochromic devices (10) are fabricated with positive electrodes (12) comprising a nanocomposite material composed of lithiated metal oxide nanoparticles (40) dispersed in a matrix composed of lithium tungsten oxide.

  19. Nanostructured Lead Compounds in Electrode Materials of a Lead-Acid Battery

    Directory of Open Access Journals (Sweden)

    A.P. Kuzmenko

    2016-11-01

    Full Text Available The nanostructure and phase composition of the electrode material of lead-acid batteries, formed by chemical transformations with involvement of sulfuric acid solutions of various concentrations, water and carbon dioxide have been studied.

  20. In situ direct growth of single crystalline metal (Co, Ni) selenium nanosheets on metal fibers as counter electrodes toward low-cost, high-performance fiber-shaped dye-sensitized solar cells.

    Science.gov (United States)

    Chen, Liang; Yin, Hexing; Zhou, Yong; Dai, Hui; Yu, Tao; Liu, Jianguo; Zou, Zhigang

    2016-01-28

    Highly crystalline metal (Co, Ni) selenium (Co0.85Se or Ni0.85Se) nanosheets were in situ grown on metal (Co, Ni) fibers (M-M0.85Se). Both M-M0.85Se (Co-Co0.85Se and Ni-Ni0.85Se) fibers prove to function as excellent, low-cost counter electrodes (CEs) in fiber-shaped dye-sensitized solar cells (FDSSCs) with high power conversion efficiency (Co-Co0.85Se 6.55% and Ni-Ni0.85Se 7.07%), comparable or even superior to a Pt fiber CE (6.54%). The good performance of the present Pt-free CE-based solar cell was believed to originate from: (1) the intrinsic electrocatalytic properties of the single-crystalline M-M0.85Se; (2) the enough void space among M0.85Se nanosheets that allows easier redox ion diffusion; (3) the two-dimensional morphology that provides a large contact area between the CE catalytic material and electrolyte; (4) in situ direct growth of the M0.85Se on metal fibers that renders good electrical contact between the active material and the electron collector.

  1. Conical surface structures on model thin-film electrodes and tape-cast electrode materials for lithium-ion batteries

    Science.gov (United States)

    Kohler, R.; Proell, J.; Bruns, M.; Ulrich, S.; Seifert, H. J.; Pfleging, W.

    2013-07-01

    Three-dimensional structures in cathode materials for lithium-ion batteries were investigated in this study. For this purpose, laser structuring of lithium cobalt oxide was investigated at first for a thin-film model system and in a second step for conventional tape-cast electrode materials. The model thin-film cathodes with a thickness of 3 μm were deposited using RF magnetron sputtering on stainless steel substrates. The films were structured via excimer laser radiation with a wavelength of 248 nm. By adjusting the laser fluence, self-organized conical microstructures were formed. Using conventional electrodes, tape-cast cathodes made of LiCoO2 with a film thickness of about 80 μm on aluminum substrates were studied. It was shown that self-organizing surface structures could be formed by adjustment of the laser parameters. To investigate the formation mechanisms of the conical topography, the element composition was studied by time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy. Electrochemical cycling using a lithium anode and conventional electrolyte was applied to study the influence of the laser processing procedures on cell performance. For the model electrode system, a significantly higher discharge capacity of 80 mAh/g could be obtained after 110 cycles by laser structuring compared to 8 mAh/g of the unstructured thin film. On conventional tape-cast electrodes self-organized surface structures could also increase the cycling stability resulting in an 80 % increase in capacity after 110 cycles in comparison to the unstructured electrode.

  2. The microstrip proportional counter

    Science.gov (United States)

    Ramsey, B. D.

    1992-01-01

    Microstrip detectors in which the usual discrete anode and cathode wires are replaced by conducting strips on an insulating or partially insulating substrate are fabricated using integrated circuit-type photolithographic techniques and hence offer very high spatial accuracy and uniformity, together with the capability of producing extremely fine electrode structures. Microstrip proportional counters have now been variously reported having an energy resolution of better than 11 percent FWHM at 5.9 keV. They have been fabricated with anode bars down to 2 microns and on a variety of substrate materials including thin films which can be molded to different shapes. This review will examine the development of the microstrip detector with emphasis on the qualities which make this detector particularly interesting for use in astronomy.

  3. The differing behavior of electrosurgical devices made of various electrode materials operating under plasma conditions

    Science.gov (United States)

    Stalder, K. R.; Ryan, T. P.; Gaspredes, J.; Woloszko, J.

    2015-03-01

    Coblation® is an electrosurgical technology which employs electrically-excited electrodes in the presence of saline solution to produce a localized and ionized plasma that can cut, ablate, and otherwise treat tissues for many different surgical needs. To improve our understanding of how Coblation plasmas develop from devices made from different electrode materials we describe several experiments designed to elucidate material effects. Initial experiments studied simple, noncommercial cylindrical electrode test devices operating in buffered isotonic saline without applied suction. The applied RF voltage, approximately 300 V RMS, was sufficient to form glow discharges around the active electrodes. The devices exhibited significantly different operating characteristics, which we ascribe to the differing oxidation tendencies and other physical properties of the electrode materials. Parameters measured include RMS voltage and current, instantaneous voltage and current, temporally-resolved light emission and optical emission spectra, and electrode mass-loss measurements. We correlate these measured properties with some of the bulk characteristics of the electrode materials such as work functions, standard reduction potentials and sputter yields.

  4. Fabrication and Evaluation of Low-cost Cu2ZnSn(S,Se)4 Counter Electrodes for Dye-sensitized Solar Cells

    Institute of Scientific and Technical Information of China (English)

    Jie Shen; Dingwen Zhang; Junjie Li; Xiaodong Li; Zhuo Sun; Sumei Huang

    2013-01-01

    We explore a simple and eco-friendly approach for preparing CZTS powders and a screen-printing process for Cu2ZnSn(S,Se)4 (CZTSSe) counter electrodes (CEs) in dye-sensitized solar cells (DSCs). Cu2ZnSnS4 (CZTS) nanoparticles have been synthesized via a hydrazine-free solvothermal approach without the assistance of organic ligands. CZTS has been prepared by directly drop-casting the CZTS ink on the cleaned FTO glass, while CZTSSe CEs have been fabricated by screen-printing CZTS pastes, followed by post selenization using Se vapor obtained from elemental Se pellets. The crystal structure, composition and morphology of the as-deposited CZTS nanoparticles and CZTSSe electrodes are characterized by X-ray diffractometer, energy dispersive spectrometer, field emission scanning electron microscopy and transmission electron microscopy. The electrochemical properties of CZTS, CZTSSe and Pt CE based DSCs are examined and analyzed by electrochemical impedance spectroscopy. The prepared CZTS and CZTSSe CEs exhibit a cellular structure with high porosity. DSCs fabricated with CZTSSe CEs achieve a power conversion efficiency of 5.75% under AM 1.5 G illumination with an intensity of 100 mW/cm2, which is higher than that (3.22%) of the cell using the CZTS CE. The results demonstrate that the CZTSSe CE possesses good electrocatalytic activity for the reduction of charge carriers in electrolyte. The comprehensive CZTSSe CE process is cheap and scalable. It can make large-scale electro-catalytic film fabrication cost competitive for both energy harvesting and storage applications.

  5. Transparent conducting oxide-free nitrogen-doped graphene/reduced hydroxylated carbon nanotube composite paper as flexible counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Zhang, Jindan; Yu, Mei; Li, Songmei; Meng, Yanbing; Wu, Xueke; Liu, Jianhua

    2016-12-01

    Three-dimensional nitrogen-doped graphene/reduced hydroxylated carbon nanotube composite aerogel (NG/CNT-OH) with unique hierarchical porosity and mechanical stability is developed through a two-step hydrothermal reaction. With plenty of exposed active sites and efficient multidimensional transport pathways of electrons and ions, NG/CNT-OH exhibits great electrocatalytic performances for I-/I3- redox couple. The subsequent compressed NG/CNT-OH papers possess high electrical conductivity and good flexibility, thus generating high-performance flexible counter electrodes (CEs) with transparent conducting oxide free (TCO-free) for dye-sensitized solar cells (DSSCs). The flexible NG/CNT-OH electrodes show good stability and the DSSCs with the optimized NG/CNT-OH CE had higher short-circuit current density (13.62 mA cm-2) and cell efficiency (6.36%) than DSSCs using Pt CE, whereas those of the DSSCs using Pt CE were only 12.81 mA cm-2 and 5.74%, respectively. Increasing the ratio of hydroxylated carbon nanotubes (CNT-OH) to the graphene oxide (GO) in the reactant would lead to less content of doped N, but better diffusion of electrolyte in the CEs because of more complete GO etching reaction. The design strategy presents a facile and cost effective way to synthesis three-dimensional graphene/CNT composite aerogel with excellent performance, and it can be potentially used as flexible TCO-free CE in other power conversion or energy storage devices.

  6. The Two-Dimensional Nanocomposite of Molybdenum Disulfide and Nitrogen-Doped Graphene Oxide for Efficient Counter Electrode of Dye-Sensitized Solar Cells

    Science.gov (United States)

    Cheng, Chao-Kuang; Lin, Che-Hsien; Wu, Hsuan-Chung; Ma, Chen-Chi M.; Yeh, Tsung-Kuang; Chou, Huei-Yu; Tsai, Chuen-Horng; Hsieh, Chien-Kuo

    2016-02-01

    In this study, we reported the synthesis of the two-dimensional (2D) nanocomposite of molybdenum disulfide and nitrogen-doped graphene oxide (MoS2/nGO) as a platinum-free counter electrode (CE) for dye-sensitized solar cells (DSSCs). X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy were used to examine the characteristics of the 2D nanocomposite of MoS2/nGO. The cyclic voltammetry (CV), electrochemical impedance spectra (EIS), and the Tafel polarization measurements were carried out to examine the electrocatalytic abilities. XPS and Raman results showed the 2D behaviors of the prepared nanomaterials. HRTEM micrographs showed the direct evidence of the 2D nanocomposite of MoS2/nGO. The results of electrocatalytic examinations indicated the MoS2/nGO owning the low charge transfer resistance, high electrocatalytic activity, and fast reaction kinetics for the reduction of triiodide to iodide on the electrolyte-electrode interface. The 2D nanocomposite of MoS2/nGO combined the advantages of the high specific surface of nGO and the plenty edge sites of MoS2 and showed the promoted properties different from those of their individual constituents to create a new outstanding property. The DSSC with MoS2/nGO nanocomposite CE showed a photovoltaic conversion efficiency (PCE) of 5.95 % under an illumination of AM 1.5 (100 mW/cm2), which was up to 92.2 % of the DSSC with the conventional platinum (Pt) CE (PCE = 6.43 %). These results reveal the potential of the MoS2/nGO nanocomposite in the use of low-cost, scalable, and efficient Pt-free CEs for DSSCs.

  7. Effect of top electrode material on radiation-induced degradation of ferroelectric thin film structures

    Energy Technology Data Exchange (ETDEWEB)

    Brewer, Steven J.; Bassiri-Gharb, Nazanin [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Deng, Carmen Z.; Callaway, Connor P. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Paul, McKinley K. [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Woodward Academy, College Park, Georgia 30337 (United States); Fisher, Kenzie J. [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Riverwood International Charter School, Atlanta, Georgia 30328 (United States); Guerrier, Jonathon E.; Jones, Jacob L. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Rudy, Ryan Q.; Polcawich, Ronald G. [Army Research Laboratory, Adelphi, Maryland 20783 (United States); Glaser, Evan R.; Cress, Cory D. [Naval Research Laboratory, Washington, DC 20375 (United States)

    2016-07-14

    The effects of gamma irradiation on the dielectric and piezoelectric responses of Pb[Zr{sub 0.52}Ti{sub 0.48}]O{sub 3} (PZT) thin film stacks were investigated for structures with conductive oxide (IrO{sub 2}) and metallic (Pt) top electrodes. The samples showed, generally, degradation of various key dielectric, ferroelectric, and electromechanical responses when exposed to 2.5 Mrad (Si) {sup 60}Co gamma radiation. However, the low-field, relative dielectric permittivity, ε{sub r}, remained largely unaffected by irradiation in samples with both types of electrodes. Samples with Pt top electrodes showed substantial degradation of the remanent polarization and overall piezoelectric response, as well as pinching of the polarization hysteresis curves and creation of multiple peaks in the permittivity-electric field curves post irradiation. The samples with oxide electrodes, however, were largely impervious to the same radiation dose, with less than 5% change in any of the functional characteristics. The results suggest a radiation-induced change in the defect population or defect energy in PZT with metallic top electrodes, which substantially affects motion of internal interfaces such as domain walls. Additionally, the differences observed for stacks with different electrode materials implicate the ferroelectric–electrode interface as either the predominant source of radiation-induced effects (Pt electrodes) or the site of healing for radiation-induced defects (IrO{sub 2} electrodes).

  8. Effect of top electrode material on radiation-induced degradation of ferroelectric thin film structures

    Science.gov (United States)

    Brewer, Steven J.; Deng, Carmen Z.; Callaway, Connor P.; Paul, McKinley K.; Fisher, Kenzie J.; Guerrier, Jonathon E.; Rudy, Ryan Q.; Polcawich, Ronald G.; Jones, Jacob L.; Glaser, Evan R.; Cress, Cory D.; Bassiri-Gharb, Nazanin

    2016-07-01

    The effects of gamma irradiation on the dielectric and piezoelectric responses of Pb[Zr0.52Ti0.48]O3 (PZT) thin film stacks were investigated for structures with conductive oxide (IrO2) and metallic (Pt) top electrodes. The samples showed, generally, degradation of various key dielectric, ferroelectric, and electromechanical responses when exposed to 2.5 Mrad (Si) 60Co gamma radiation. However, the low-field, relative dielectric permittivity, ɛr, remained largely unaffected by irradiation in samples with both types of electrodes. Samples with Pt top electrodes showed substantial degradation of the remanent polarization and overall piezoelectric response, as well as pinching of the polarization hysteresis curves and creation of multiple peaks in the permittivity-electric field curves post irradiation. The samples with oxide electrodes, however, were largely impervious to the same radiation dose, with less than 5% change in any of the functional characteristics. The results suggest a radiation-induced change in the defect population or defect energy in PZT with metallic top electrodes, which substantially affects motion of internal interfaces such as domain walls. Additionally, the differences observed for stacks with different electrode materials implicate the ferroelectric-electrode interface as either the predominant source of radiation-induced effects (Pt electrodes) or the site of healing for radiation-induced defects (IrO2 electrodes).

  9. A non-platinum counter electrode, MnNx/C, for dye-sensitized solar cell applications

    Science.gov (United States)

    Kushwaha, Suman; M. P., Karthikayini; Wang, Guanxiong; Mandal, Sudip; Bhobe, Preeti. A.; Ramani, Vijay K.; Priolkar, K. R.; Ramanujam, Kothandaraman

    2017-10-01

    A non-platinum metal catalyst, MnNx/C was synthesized via the high-pressure pyrolysis route. The combination of X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) studies indicated the presence of Mn in +2 oxidation state surrounded by four N atoms. The peak-to-peak separation (ΔEp) of the more negative peak pair observed for I3-/I- redox couple over MnNx/C catalyst was 20 mV lower than that of the Pt catalyst, indicating high reversibility of the redox couple over MnNx/C catalyst. The charge transfer resistance of the MnNx/C electrode, as measured by the impedance spectroscopy, is ∼ 2 Ω higher than that of Pt, which resulted slightly lower short circuit current (Jsc) value for MnNx/C over Pt, however the fill factor (FF) and power conversion efficiency (PCE) values of MnNx/C was slightly higher and comparable to that of Pt respectively. Hence; replacing Pt with MnNx/C would decrease the cost of DSSCs.

  10. XPS investigations of electrolyte/electrode interactions for various Li-ion battery materials

    Energy Technology Data Exchange (ETDEWEB)

    Oswald, S.; Mikhailova, D.; Scheiba, F.; Reichel, P.; Fiedler, A.; Ehrenberg, H. [IFW Dresden, Dresden (Germany)

    2011-05-15

    For future Li-ion battery applications the search for both new design concepts and materials is necessary. The electrodes of the batteries are always in contact with electrolytes, which are responsible for the transport of Li ions during the charging and discharging process. A broad range of materials is considered for both electrolytes and electrodes so that very different chemical interactions between them can occur, while good cycling behavior can only be obtained for stable solid-electrolyte interfaces. X-ray photoelectron spectroscopy (XPS) was used to study the most relevant interactions between various electrode materials in contact with different electrolyte solutions. It is shown how XPS can provide useful information on reactivities and thus preselect suitable electrode/electrolyte combinations, prior to electrochemical performance tests. (orig.)

  11. Unconventional supercapacitors from nanocarbon-based electrode materials to device configurations.

    Science.gov (United States)

    Liu, Lili; Niu, Zhiqiang; Chen, Jun

    2016-07-25

    As energy storage devices, supercapacitors that are also called electrochemical capacitors possess high power density, excellent reversibility and long cycle life. The recent boom in electronic devices with different functions in transparent LED displays, stretchable electronic systems and artificial skin has increased the demand for supercapacitors to move towards light, thin, integrated macro- and micro-devices with transparent, flexible, stretchable, compressible and/or wearable abilities. The successful fabrication of such supercapacitors depends mainly on the preparation of innovative electrode materials and the design of unconventional supercapacitor configurations. Tremendous research efforts have been recently made to design and construct innovative nanocarbon-based electrode materials and supercapacitors with unconventional configurations. We review here recent developments in supercapacitors from nanocarbon-based electrode materials to device configurations. The advances in nanocarbon-based electrode materials mainly include the assembly technologies of macroscopic nanostructured electrodes with different dimensions of carbon nanotubes/nanofibers, graphene, mesoporous carbon, activated carbon, and their composites. The electrodes with macroscopic nanostructured carbon-based materials overcome the issues of low conductivity, poor mechanical properties, and limited dimensions that are faced by conventional methods. The configurational design of advanced supercapacitor devices is presented with six types of unconventional supercapacitor devices: flexible, micro-, stretchable, compressible, transparent and fiber supercapacitors. Such supercapacitors display unique configurations and excellent electrochemical performance at different states such as bending, stretching, compressing and/or folding. For example, all-solid-state simplified supercapacitors that are based on nanostructured graphene composite paper are able to maintain 95% of the original capacity at

  12. Suppression of charge recombination by application of Cu2ZnSnS4-graphene counter electrode to thin dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    Yan Li; Huafei Guo; Xiuqin Wang; Ningyi Yuan; Jianning Ding

    2016-01-01

    This paper proposes a new mechanism to explain the performance of thin dye-sensitized solar cells (DSSC).Near-stoichiometric flower-like Cu2ZnSnS4 (CZTS) microspheres with a high specific surface area was fabricated for use as the photocathode in a DSSC.To improve the extraction and transfer of electrons,graphene was added to the CZTS.A DSSC with a 10-μm TiO2 photoanode layer exhibited a slightly degraded efficiency with a CZTS-graphene photocathode,relative to a Pt counter electrode (CE).Nevertheless,when the thickness of the TiO2 photoanode was reduced to 2 μm,the efficiency of a DSSC with a CZTS-graphene photocathode was greater than that of a Pt-DSSC.It is speculated that,unlike the Pt CE,a CZTS-graphene photocathode not only collects electrons from an external circuit and catalyzes the reduction of the triiodide ions in the electrolyte,but also utilizes unabsorbed photons to produce photo-excited electrons and suppresses charge recombination,thus enhancing the performance of the cell.The use of narrow band gap p-type semiconductors as photocathodes offers a new means of fabricating thin dye-sensitized solar cells and effectively improving the cell performance.

  13. Facile synthesis of porous CuS film as a high efficient counter electrode for quantum-dot-sensitized solar cells

    Science.gov (United States)

    Lin, Yibing; Lin, Yu; Wu, Jihuai; Zhang, Xiaolong; Fang, Biaopeng

    2016-06-01

    In this paper, porous CuS film has been successfully prepared by a facile method and employed as a counter electrode (CE) in quantum-dot-sensitized solar cells (QDSSCs) for its highest catalytic activity. This CuS thin film was deposited on FTO substrate via spin coating process which is simple to operate, and its electrochemical properties were further studied by EIS and Tafel measurement. With the cycling time of depositing CuS up to 8, it displays high electrocatalytic activity toward polysulfide reduction, rationalizing the improved QDSSCs performance. Using the CdS/CdSe-sensitized QDSSCs, the cells exhibit improved short-circuit photocurrent density ( J sc) and fill factor (FF), achieving solar cell conversion efficiency ( η) as high as 5.60 % under AM 1.5 illumination of 100 mW cm-2. This work provides a novel and simple method for the preparation of CEs, which could be utilized in other metal sulfides CEs for QDSSCs.

  14. Vanadium oxides (V{sub 2}O{sub 5}) prepared with different methods for application as counter electrodes in dye-sensitized solar cells (DSCs)

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kezhong; Sun, Xiaolong; Duan, Chongyuan; Gao, Jing; Wu, Mingxing [Hebei Normal University, College of Chemistry and Material Science, Key Laboratory of Inorganic Nano-materials of Hebei Province, Shijiazhuang City, Hebei Province (China)

    2016-09-15

    V{sub 2}O{sub 5} was synthesized by four different procedures employing thermal decomposition, sol-gel, and hydrothermal methods which were subsequently introduced into dye-sensitized solar cells (DSCs) as counter electrode (CE) catalysts for the regeneration of traditional iodide/triiodide (I{sup -}/I{sub 3} {sup -}) redox couple. The catalytic activities of as-prepared V{sub 2}O{sub 5} were significantly affected by the synthetic routes as evidenced by cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization curve. Power conversion efficiency (PCE) of the DSCs employing V{sub 2}O{sub 5} CE, fabricated by thermal decomposition method, was observed to be 3.80 % by using citric acid as an additive, while the PCE of the DSCs using V{sub 2}O{sub 5} CE prepared by hydrothermal and thermal decomposition methods without additive, as well as by a sol-gel procedure, was determined to be 2.13, 2.08, and 2.04 %, respectively. (orig.)

  15. Design of an organic redox mediator and optimization of an organic counter electrode for efficient transparent bifacial dye-sensitized solar cells.

    Science.gov (United States)

    Li, Xiong; Ku, Zhiliang; Rong, Yaoguang; Liu, Guanghui; Liu, Linfeng; Liu, Tongfa; Hu, Min; Yang, Ying; Wang, Heng; Xu, Mi; Xiang, Peng; Han, Hongwei

    2012-11-07

    A new thiolate/disulfide mediator was designed and synthesized by employing DFT calculations as a guide. It possesses high transparency to visible light, a very attractive feature for bifacially active transparent DSCs that require a highly transparent counter electrode (CE). Compared to the reported and most promising thiolate/disulfide mediator T(-)/T(2), this new analogous mediator produced a major enhancement in open circuit potential (V(OC)) by about 40 mV and correspondingly a higher power conversion efficiency (η) for DSCs. Furthermore, a highly uniform and transparent (transmittance > 91%) poly(3,4-ethylenedioxythiophene) (PEDOT(BE)) CE was prepared and could efficiently catalyze the reduction of the disulfide. Based on the novel transparent redox couple and PEDOT(BE) CE, a new type of iodine-free and Pt-free transparent bifacial DSC was successfully fabricated. This new bifacial device could not only yield a promising front-illuminated η of 6.07%, but also produce an attractive η as high as 4.35% for rear-side irradiation, which exceeds the rear-illuminated η of 3.93% achieved for the same type of device, employing the dark-colored I(-)/I(3)(-) electrolyte.

  16. Flexible carbon nanotube/polypropylene composite plate decorated with poly(3,4-ethylenedioxythiophene) as efficient counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Lin, Jeng-Yu; Wang, Wei-Yen; Chou, Shu-Wei

    2015-05-01

    In this study, we fabricate an efficient, flexible and low-cost counter electrode (CE) composed of a plasma-etched carbon nanotubes/polypropylene (designated as ECP) composite plate decorated with poly(3,4-ethylene dioxythiophene) (PEDOT) for dye-sensitized solar cells (DSCs). The PEDOT-decorated monolithic ECP CEs are fabricated via series of processes including high-temperature refluxing, thermal compression, oxygen plasma etching, and electropolymerization. The bottom ECP plate is used to replace conventional transparent conducting oxide (TCO) as a conductive substrate, and the top PEDOT layer is employed as catalyst for I3- reduction. According to the extensive electrochemical measurements, the as-fabricated flexible PEDOT coated ECP CE demonstrates a Pt-like electrocatalytic for I3- reduction. The DSC based on the flexible PEDOT-decorated ECP CE yields impressive energy conversion efficiency of 6.82% (or 6.77% even after the bending test), which is comparable to that of the DSC using the Pt CE (7.20%) under similar device architecture conditions. Therefore, the PEDOT-decorated ECP based CEs show the possibility of serving as low-cost and flexible CEs for efficient DSCs.

  17. Honeycomb-like poly(3,4-ethylenedioxythiophene) as an effective and transparent counter electrode in bifacial dye-sensitized solar cells

    Science.gov (United States)

    Li, Honggang; Xiao, Yaoming; Han, Gaoyi; Hou, Wenjing

    2017-02-01

    Honeycomb-like poly(3,4-ethylenedioxythiophene) (PEDOT) counter electrode (CE) for the bifacial dye-sensitized solar cell (DSSC) is first prepared by a facile method using a sacrificial template of poly(methyl methacrylate) (PMMA). Cyclic voltammetry and ultraviolet-visible spectrophotometer measurements indicate that the PEDOT CE with honeycomb-like nanostructure demonstrates excellent electrocatalytic activity for the reduction of triiodide (I3-) to iodide (I-) and high transparency for the backside illumination. Electrochemical impedance spectroscopy measurements show that the honeycomb-like nanostructure reduces the CE's resistance for the transfer of electrons from the external circuit back to the redox electrolyte. The bifacial DSSC based on the honeycomb-like PEDOT CE yields front and rear efficiencies of 9.12% and 5.75%, which are higher than those of the bifacial DSSC based on the flat PEDOT (8.05% and 3.78% respectively). These promising results highlight the potential application of the facile template method for preparing other cost-effective and transparent CEs, which can be used in bifacial solar cells and tandem devices.

  18. A microwave synthesized CuxS and graphene oxide nanoribbon composite as a highly efficient counter electrode for quantum dot sensitized solar cells.

    Science.gov (United States)

    Ghosh, Dibyendu; Halder, Ganga; Sahasrabudhe, Atharva; Bhattacharyya, Sayan

    2016-05-19

    To boost the photoconversion efficiency (PCE) of ever promising quantum dot sensitized solar cells (QDSSCs), and to improve the design of photoanodes, the ability of the counter electrode (CE) to effectively reduce the oxidized electrolyte needs special attention. A composite of a 15 wt% graphene oxide nanoribbon (GOR), obtained by unzipping multi-walled carbon nanotubes (MWCNTs), and CuxS intersecting hexagonal nanoplates, synthesized by a low cost, facile and scalable microwave synthesis route, is reported as a fascinating CE for QDSSCs. The best performing Cu1.18S-GOR CE could notably achieve a record PCE of ∼3.55% for CdS sensitized QDSSCs, ∼5.42% for in situ deposited CdS/CdSe co-sensitized QDSSCs and ∼6.81% for CdTe/CdS/CdS dual sensitized QDSSCs, apart from increasing the PCE of previously reported QDSSCs. A systematic investigation of the CE design revealed the high electrocatalytic activity of GOR due to the presence of organic functional groups, graphitic edge sites and a quasi-one-dimensional (quasi-1D) structure, which increases the interfacial charge transfer kinetics from the CE to the polysulfide electrolyte. The highly stable Cu1.18S-GOR CE has the added advantage of a favourable energy band alignment with the redox potential of the polysulfide electrolyte, which reduces the loss of charge carriers and thus can increase the PCE of QDSSCs.

  19. Honeycomb-like NiCo2S4 nanosheets prepared by rapid electrodeposition as a counter electrode for dye-sensitized solar cells

    Science.gov (United States)

    Yin, Jie; Wang, Yuqiao; Meng, Wenfei; Zhou, Tianyue; Li, Baosong; Wei, Tao; Sun, Yueming

    2017-08-01

    Honeycomb-like nickel cobalt sulfide (NiCo2S4) nanosheets were directly deposited on fluorine-doped tin oxide substrate by a rapid voltammetric deposition method. The method was also controllable and feasible for preparing NiCo2S4 on flexible Ti foil without any heating processes. Compared with Pt, CoS and NiS, NiCo2S4 exhibited low charge-transfer resistances and excellent electrocatalytic activity for {{{{I}}}3}- reduction, acting as a counter electrode for a dye-sensitized solar cell. The NiCo2S4-based solar cell showed higher power conversion efficiency (7.44%) than that of Pt-based solar cell (7.09%) under simulated illumination (AM 1.5 G, 100 mW cm-2). The device based on the flexible NiCo2S4/Ti foil achieved a power conversion efficiency of 5.28% under the above illumination conditions. This work can be extended to flexible and wearable technologies due to its facile technique.

  20. One-step solvothermal tailoring the compositions and phases of nickel cobalt sulfides on conducting oxide substrates as counter electrodes for efficient dye-sensitized solar cells

    Science.gov (United States)

    Huang, Niu; Li, Guowang; Huang, Hua; Sun, Panpan; Xiong, Tianli; Xia, Zhifen; Zheng, Fang; Xu, Jixing; Sun, Xiaohua

    2016-12-01

    Several nickel cobalt sulfide (Ni-Co-S) counter electrodes (CEs) are prepared, and the Ni-Co-S nanoparticles are in-situ grown on SnO2: F (FTO) transparent conductive glasses via a facile solvothermal process, in which thiourea is used as the sulfurizing reagent. The X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometer are employed to measure the microstructure and composition of the Ni-Co-S CEs. When a proper amount of thiourea is adopted, fine crystalline NiCo2S4 CE is obtained. When the amount of thiourea is small or large, (Ni,Co)4S3 or (Ni,Co)3S4 CE is acquired, respectively. Cyclic voltammetry, electrochemical impedance spectroscopy, Tafel polarization and open-circuit voltage decay (OCVD) measurements all demonstrate that the electrocatalytic activities and electrical conductivities of these Ni-Co-S CEs all approach or exceed those of Pt-pyrolysis CE. Their superior electrochemical performances are further confirmed by fabricating DSSCs with the Ni-Co-S CEs, they display similar or better photo-electric conversion efficiencies to/than the Pt-pyrolysis counterpart.

  1. Low-cost Cr doped Pt3Ni alloy supported on carbon nanofibers composites counter electrode for efficient dye-sensitized solar cells

    Science.gov (United States)

    Xiao, Junying; Cui, Midou; Wang, Mingkun; Sui, Huidong; Yang, Kun; Li, Ling; Zhang, Wenming; Li, Xiaowei; Fu, Guangsheng; Hagfeldt, Anders; Zhang, Yucang

    2016-10-01

    Pt3Ni alloy supported by carbon nanofibers (CNs) composites (Pt3Ni/CNs) synthesized by a simple solvothermal process was introduced into dye-sensitized solar cells (DSCs) as counter electrode (CE) for the first time, and the DSCs based on Pt3Ni/CNs CE obtained a power conversion efficiency (PCE) of 8.34%. To enhance the catalytic activity of Pt3Ni/CNs composites, transition metal chrome (Cr) was doped in Pt3Ni/CNs to synthesize the composites of Cr-Pt3Ni/CNs using the same method. Due to the high electrocatalytic activity and rapid charge transfer ability, the PCE of the DSCs employing Cr-Pt3Ni/CNs as CE increased to 8.76%, which was much higher than that of Pt CE (7.04%) measured in the same condition. The impressive results along with low cost and simple synthesis process demonstrated transition metal doping was a promising method to produce substitutes for Pt to reduce the cost and increase the PCE of DSCs.

  2. Hydrothermal synthesis of graphene flake embedded nanosheet-like molybdenum sulfide hybrids as counter electrode catalysts for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jeng-Yu, E-mail: jylin@ttu.edu.tw [Department of Chemical Engineering, Tatung University, No. 40, Sec. 3, ChungShan North Rd., Taipei City 104, Taiwan (China); Yue, Gentian [Department of Chemical Engineering, Tatung University, No. 40, Sec. 3, ChungShan North Rd., Taipei City 104, Taiwan (China); Institute of Materials Physical Chemistry, Huaqiao University, Quanzhou, Fujian 362021 (China); Tai, Sheng-Yen [Department of Chemical Engineering, Tatung University, No. 40, Sec. 3, ChungShan North Rd., Taipei City 104, Taiwan (China); Xiao, Yaoming [Department of Chemical Engineering, Tatung University, No. 40, Sec. 3, ChungShan North Rd., Taipei City 104, Taiwan (China); Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Shanxi University, Taiyuan 030006 (China); Cheng, Ho-Ming; Wang, Fu-Ming [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei City 106, Taiwan (China); Wu, Jihuai [Institute of Materials Physical Chemistry, Huaqiao University, Quanzhou, Fujian 362021 (China)

    2013-12-16

    In this study, graphene flake (GF) was successfully embedded into a nanosheet-like molybdenum sulfide (MoS{sub 2}) matrix via an in situ hydrothermal route, and the resultant hybrid was employed as a counter electrode (CE) for Pt-free dye-sensitized solar cells (DSCs). It is confirmed from scanning electron microscopy, X-ray diffraction, Raman spectroscopy and transmission electron microscopy that GFs are successfully incorporated in the nanosheet-like MoS{sub 2} matrix and thus result in its surface evolution. The extensive electrochemical analyses reveal that the remarkably enhanced electrocatalytic activity can be demonstrated when GFs are incorporated in the MoS{sub 2} matrix. After the optimization, the nanosheet-like MoS{sub 2}/GF hybrid with 1.5 wt.% GF shows the best electrocatalytic activity. The DSC assembled with the novel nanosheet-like MoS{sub 2}/GF hybrid CE exhibits a high photovoltaic conversion efficiency of 6.07% under standard illumination, up to 95% of the level obtained using conventional Pt CE (6.41%). - Highlights: • Nanosheet-like MoS{sub 2}/graphene flake hybrid was prepared by a hydrothermal route. • The surface morphology of MoS{sub 2} changed with the incorporation of graphene flake. • The hybrid with 1.5 wt.% graphene flake showed the superior catalytic activity. • The cell efficiency of DSC with the hybrid CE reached 95% of that using Pt CE.

  3. Compliant Electrode and Composite Material for Piezoelectric Wind and Mechanical Energy Conversions

    Science.gov (United States)

    Chen, Bin (Inventor)

    2015-01-01

    A thin film device for harvesting energy from wind. The thin film device includes one or more layers of a compliant piezoelectric material formed from a composite of a polymer and an inorganic material, such as a ceramic. Electrodes are disposed on a first side and a second side of the piezoelectric material. The electrodes are formed from a compliant material, such as carbon nanotubes or graphene. The thin film device exhibits improved resistance to structural fatigue upon application of large strains and repeated cyclic loadings.

  4. Improving the efficiency of quantum-dot-sensitized solar cells by optimizing the growth time of the CuS counter electrode

    Science.gov (United States)

    Sunesh, Chozhidakath Damodharan; Gopi, Chandu V. V. M.; Muthalif, Mohammed Panthakkal Abdul; Kim, Hee-Je; Choe, Youngson

    2017-09-01

    CuS counter electrodes (CEs) were prepared to fabricate efficient quantum-dot-sensitized solar cells (QDSSCs) based on a CdS/CdSe photo sensitizer. The CEs were prepared on a fluorine-doped tin oxide (FTO) glass substrate by a facile chemical bath deposition (CBD) method by dissolving CuSO4·5H2O and CH3CSNH2 in water, followed by adding 0.25 mM polyvinylpyrrolidone (PVP). The CBD was performed at 60 °C for 1 h, 2 h, and 3 h, and the samples were labeled as CuS 1 h, CuS 2 h, and CuS 3 h, respectively. The QDSSCs were assembled using prepared CuS CEs and a TiO2/CdS/CdSe/ZnS photoanode, and the effect of the growth time of CuS CEs on the QDSSC performance was investigated. As the CuS growth time increases, the short-circuit current density (Jsc), fill factor (FF), and open-circuit voltage (Voc) of the QDSSCs gradually increases, leading to an enhanced power conversion efficiency (η). QDSSCs that use the CuS 2 h CE exhibit a high Jsc of 14.31 mA cm-2, Voc of 0.603 V, and FF of 0.49, which are higher than that using conventional Pt electrodes as well as CuS 1 h and CuS 3 h electrodes. The electrochemical impedance spectroscopy results show that the CuS 2 h CE exhibits an inferior charge transfer resistance of only 2.93 Ω, which is 33 times lesser than that of the Pt CE. The enhanced device performance of CuS 2 h is ascribed to the high catalytic activity and low charge transfer resistance of the CuS CE in the reduction process of oxidized polysulfide. Consequently, a superior power conversion efficiency of 4.27% is achieved for QDSSCs utilizing CuS 2 h.

  5. Effect of Different Electrode Materials on the Electropolymerization Process of Aniline in Nitric Acid Media

    Science.gov (United States)

    Li, Yaozong; Yi, Yun; Yang, Weifang; Liu, Xiaoqing; Li, Yuanyuan; Wang, Wei

    2016-11-01

    The electropolymerization process of aniline on different electrode surfaces such as Pt, Au, RuTi and polyaniline film in nitric acid solution containing 1 M aniline was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Proposed electrical equivalent circuits were used to give a further analysis. Results show that the electrode materials accelerate the aniline electropolymerization remarkably as a catalyst, especially the electrochemical oxidation process of monomer aniline to its cation radical, which is the key step to incur the electropolymerization reaction of aniline on the electrode surface. The polymerization of aniline on RuTi electrode has the lowest reaction resistance for its adsorption sites, and the catalytic effects of these different electrodes decrease in the order: RuTi > polyaniline film > Pt > Au. The results also show that several states of polyaniline films are formed during the potential linear scan process in nitric acid solution and the corresponding oxidation and reduction reaction are reversible.

  6. Effect of Different Electrode Materials on the Electropolymerization Process of Aniline in Nitric Acid Media

    Science.gov (United States)

    Li, Yaozong; Yi, Yun; Yang, Weifang; Liu, Xiaoqing; Li, Yuanyuan; Wang, Wei

    2017-02-01

    The electropolymerization process of aniline on different electrode surfaces such as Pt, Au, RuTi and polyaniline film in nitric acid solution containing 1 M aniline was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Proposed electrical equivalent circuits were used to give a further analysis. Results show that the electrode materials accelerate the aniline electropolymerization remarkably as a catalyst, especially the electrochemical oxidation process of monomer aniline to its cation radical, which is the key step to incur the electropolymerization reaction of aniline on the electrode surface. The polymerization of aniline on RuTi electrode has the lowest reaction resistance for its adsorption sites, and the catalytic effects of these different electrodes decrease in the order: RuTi > polyaniline film > Pt > Au. The results also show that several states of polyaniline films are formed during the potential linear scan process in nitric acid solution and the corresponding oxidation and reduction reaction are reversible.

  7. Novel air electrode for metal-air battery with new carbon material and method of making same

    Science.gov (United States)

    Ross, P.N. Jr.

    1988-06-21

    This invention relates to a rechargeable battery or fuel cell. More particularly, this invention relates to a novel air electrode comprising a new carbon electrode support material and a method of making same. 3 figs.

  8. Electrochemical deposition of molybdenum sulfide thin films on conductive plastic substrates as platinum-free flexible counter electrodes for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chao-Kuang; Hsieh, Chien-Kuo, E-mail: jack_hsieh@mail.mcut.edu.tw

    2015-06-01

    In this study, pulsed electrochemical deposition (pulsed ECD) was used to deposit molybdenum sulfide (MoS{sub x}) thin films on indium tin oxide/polyethylene naphthalate (ITO/PEN) substrates as flexible counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The surface morphologies and elemental distributions of the prepared MoS{sub x} thin films were examined using field-emission scanning electron microscope (FE-SEM) equipped with energy-dispersive X-ray spectroscopy. The chemical states and crystallinities of the prepared MoS{sub x} thin films were examined by X-ray photoelectron spectroscopy and X-ray diffraction, respectively. The optical transmission (T (%)) properties of the prepared MoS{sub x} samples were determined by ultraviolet–visible spectrophotometry. Cyclic voltammetry (CV) and Tafel-polarization measurements were performed to analyze the electrochemical properties and catalytic activities of the thin films for redox reactions. The FE-SEM results showed that the MoS{sub x} thin films were deposited uniformly on the ITO/PEN flexible substrates via the pulsed ECD method. The CV and Tafel-polarization curve measurements demonstrated that the deposited MoS{sub x} thin films exhibited excellent performances for the reduction of triiodide ions. The photoelectric conversion efficiency (PCE) of the DSSC produced with the pulsed ECD MoS{sub x} thin-film CE was examined by a solar simulator. In combination with a dye-sensitized TiO{sub 2} working electrode and an iodine-based electrolyte, the DSSC with the MoS{sub x} flexible CE showed a PCE of 4.39% under an illumination of AM 1.5 (100 mW cm{sup −2}). Thus, we report that the MoS{sub x} thin films are active catalysts for triiodide reduction. The MoS{sub x} thin films are prepared at room temperature and atmospheric pressure and in a simple and rapid manner. This is an important practical contribution to the production of flexible low-cost thin-film CEs based on plastic substrates. The MoS{sub x

  9. High performance electrocatalyst consisting of CoS nanoparticles on an organized mesoporous SnO2 film: its use as a counter electrode for Pt-free, dye-sensitized solar cells

    Science.gov (United States)

    Park, Jung Tae; Lee, Chang Soo; Kim, Jong Hak

    2014-12-01

    High energy conversion efficiencies of 6.6% and 7.5% are demonstrated in solid and liquid states, Pt-free, dye-sensitized solar cells (DSSCs), respectively, based on CoS nanoparticles on an organized mesoporous SnO2 (om-SnO2) counter electrode. These results correspond to improvements of 14% and 9%, respectively, compared to a conventional Pt counter electrode and are among the highest values reported for Pt-free DSSCs. The om-SnO2 layer plays a pivotal role as a platform to deposit a large amount of highly electrocatalytically active CoS nanoparticles via a facile solvothermal reaction. The om-SnO2 platform with a high porosity, larger pores, and good interconnectivity is derived from a poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) graft copolymer template, which provides not only improved interaction sites for the formation of CoS nanoparticles but also enhanced electron transport. The structural, morphological, chemical, and electrochemical properties of CoS on the om-SnO2 platform are investigated using field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) measurements. The performance enhancement results from the excellent electron transport at the fluorine-doped tin oxide (FTO)/counter electrode/electrolyte interface, reduced resistance at the FTO/CoS interface, and better catalytic reduction at the counter electrode/electrolyte interface.High energy conversion efficiencies of 6.6% and 7.5% are demonstrated in solid and liquid states, Pt-free, dye-sensitized solar cells (DSSCs), respectively, based on CoS nanoparticles on an organized mesoporous SnO2 (om-SnO2) counter electrode. These results correspond to improvements of 14% and 9%, respectively, compared to a conventional Pt counter electrode and are among the

  10. Synthesis of carbon nanotubes over 3D cubical Co-KIT-6 and nickel decorated graphene by Hummer's method, its application as counter electrode in dye sensitive solar cell

    Science.gov (United States)

    Subramanian, Sunu; Pandurangan, Arumugam

    2016-04-01

    The challenges on carbon nanotubes and graphene are still the subject of many research works due to its unique properties. There are three main methods to synthesis carbon nanotubes in which chemical vapor deposition (CVD) method can use for large scale production. The principle of CVD is the decomposition of various hydrocarbons over transition metal supported catalyst. KIT-6 molecular sieve was used as a support to prepare cobalt catalyst for CVD method using metal impregnation method to produce cobalt loadings of 2, 4 and 6 wt%. The catalysts were characterized by XRD, FTIR &TEM. Carbon nanotubes (CNTs) synthesized on Co-KIT-6 was also characterized by XRD, TGA, SEM & Raman spectra. Graphene was synthesized by Hummers method, which is the most common method for preparing graphene oxide. Graphene oxide was prepared by oxidation of graphite using some oxidizing agents like sulphuric acid, sodium nitrate and potassium permanganate. This graphene oxide is further treated with hydrazine solution to convert it into chemically converted graphene and also decorated with nickel metal and characterized. Hummer's method is important for large scale production of graphene. Both Graphene and carbon nanotubes are used in different fields due to its unique properties. Both Graphene and carbon nanotubes are fabricated in counter electrode of Dye sensitized solar cells (DSSC). By cyclic voltammetry study, it confirms that both materials are good and efficient to replace platinum in the DSSC.

  11. Enhanced Imaging of Lithium Ion Battery Electrode Materials

    OpenAIRE

    Biton, M; Yufit, V; Tariq, F; Kishimoto, M; Brandon, NP

    2016-01-01

    In this study we present a novel method of lithium ion battery electrode sample preparation with a new type of epoxy impregnation, brominated (Br) epoxy, which is introduced here for the first time for this purpose and found suitable for focused ion beam scanning electron microscope (FIB-SEM) tomography. The Br epoxy improves image contrast, which enables higher FIB-SEM resolution (3D imaging), which is amongst the highest ever reported for composite LFP cathodes using FIB-SEM. In turn it mea...

  12. Effect of electrode material and design on sensitivity and selectivity for high temperature impedancemetric NOx sensors

    Energy Technology Data Exchange (ETDEWEB)

    Woo, L Y; Glass, R S; Novak, R F; Visser, J H

    2009-09-23

    Solid-state electrochemical sensors using two different sensing electrode compositions, gold and strontium-doped lanthanum manganite (LSM), were evaluated for gas phase sensing of NO{sub x} (NO and NO{sub 2}) using an impedance-metric technique. An asymmetric cell design utilizing porous YSZ electrolyte exposed both electrodes to the test gas (i.e., no reference gas). Sensitivity to less than 5 ppm NO and response/recovery times (10-90%) less than 10 s were demonstrated. Using an LSM sensing electrode, virtual identical sensitivity towards NO and NO{sub 2} was obtained, indicating that the equilibrium gas concentration was measured by the sensing electrode. In contrast, for cells employing a gold sensing electrode the NO{sub x} sensitivity varied depending on the cell design: increasing the amount of porous YSZ electrolyte on the sensor surface produced higher NO{sub 2} sensitivity compared to NO. In order to achieve comparable sensitivity for both NO and NO{sub 2}, the cell with the LSM sensing electrode required operation at a lower temperature (575 C) than the cell with the gold sensing electrode (650 C). The role of surface reactions are proposed to explain the differences in NO and NO{sub 2} selectivity using the two different electrode materials.

  13. Evaluation of electrode materials for all-copper hybrid flow batteries

    Science.gov (United States)

    Leung, Puiki; Palma, Jesus; Garcia-Quismondo, Enrique; Sanz, Laura; Mohamed, M. R.; Anderson, Marc

    2016-04-01

    This work evaluates a number of two- and three-dimensional electrodes for the reactions of an all-copper hybrid flow battery. Half- and full-cell experiments are conducted by minimizing the crossover effect of the copper(II) species. The battery incorporates a Nafion® cation exchange membrane and the negative electrolyte is maintained at the monovalent (colourless) state by the incorporating copper turnings in the electrolyte reservoir. Under such conditions, the half-cell coulombic efficiencies of the negative electrode reactions are all higher than 90% regardless of electrode materials and the state-of-charge (SOC). With charge-discharge cycling the half-cell from a 0% SOC, the coulombic efficiencies of the positive electrode reactions are lower than 76% with the planar carbon electrode, which further decrease in shorter charge-discharge cycles. Polarization and half-cell charge-discharge experiments suggest that the high-surface-area electrodes effectively reduce the overpotentials and improve the coulombic efficiencies of both electrode reactions. When copper fibres and carbon felt are used as the negative and positive electrodes, the average coulombic and voltage efficiencies of an all-copper flow battery are as high as c.a. 99% and c.a. 60% at 50 mA cm-2 for 35 cycles.

  14. Understanding the influence of the electrode material on microbial fuel cell performance

    Science.gov (United States)

    Sanchez, David V. P.

    In this thesis, I deploy sets of electrodes into microbial fuel cells (MFC), characterize their performance, and evaluate the influence of both platinum catalysts and carbon-based electrodes on current production. The platinum work centers on improving current production by optimizing the use of the catalyst using nano-fabrication techniques. The carbon-electrode work seeks to determine the influence of the bare electrode on biofilm-anode current production. The development of electrodes for MFCs has boomed over the past decade, however, experiments aimed at identifying how catalyst deposition methods and electrode properties influence current production have been limited. The research conducted here is an attempt to expand this knowledge base for platinum catalysts and carbon electrodes. In the initial chapters (4 and 5), I discuss our attempt to decrease catalyst loadings while increasing current production through the use of platinum nanoparticles. The results demonstrate that incorporating platinum nanoparticles throughout the anode and cathode is an efficient means of increasing MFC current production relative to surface deposition because it increases catalyst surface area. The later chapters (chapters 6 and 7) develop an understanding of the importance of electrode properties (i.e. surface area, activation resistance, conductivity, surface morphology) by electrochemically evaluating well-studied anode-respiring pure cultures on different carbon electrode architectures. Two different architectures are produced by using tubular and platelet shaped constituent materials (i.e. carbon fibers and graphene nanoplatelets) and the morphologies of the electrodes are varied by altering the size of the constituent material. The electrodes are characterized and evaluated in MFCs using either Shewanella oneidensis MR-1 or Geobacter sulfurreducens as the innoculant because their bioelectrochemical physiologies are the most documented in the literature. Using the

  15. Application of Cu2S Counter Electrode in Quantum Dot-Sensitized Solar Cells%硫化亚铜对电极在量子点敏化太阳电池中的应用

    Institute of Scientific and Technical Information of China (English)

    朱俊; 余学超; 王时茂; 董伟伟; 胡林华; 方晓东; 戴松元

    2013-01-01

    Cu2S counter electrodes were prepared from the metal chalcogenide complex precursor using a novel method. A porous TiO2 nanoparticle film and TiO2 nanorod array photoanode were also fabricated. The corresponding CdS/CdSe-sensitized solar cel s with the Cu2S counter electrode were assembled and their photovoltaic performances were studied. The catalytic performance of the Cu2S counter electrodes was investigated using electrochemical impedance spectroscopy. Compared with a platinum counter electrode, the Cu2S one exhibited higher catalytic activity and better photovoltaic performance in quantum dot-sensitized solar cel s.%  报道了一种基于硫族金属复合物N4H9Cu7S4前驱体溶液制备硫化亚铜对电极的新方法。分别制备了TiO2纳米颗粒多孔薄膜和TiO2纳米棒阵列结构的光阳极,并在此基础上研究了基于硫化亚铜对电极的CdS/CdSe量子点敏化太阳电池的光电性能,同时结合电化学阻抗技术考察了硫化亚铜对电极的催化性能。结果表明:与铂电极相比,本方法制备的硫化亚铜电极对多硫电解质具有更高的催化活性,所组装的CdS/CdSe量子点敏化太阳电池具有更优的光伏性能。

  16. High performance electrocatalyst consisting of CoS nanoparticles on an organized mesoporous SnO2 film: its use as a counter electrode for Pt-free, dye-sensitized solar cells.

    Science.gov (United States)

    Park, Jung Tae; Lee, Chang Soo; Kim, Jong Hak

    2015-01-14

    High energy conversion efficiencies of 6.6% and 7.5% are demonstrated in solid and liquid states, Pt-free, dye-sensitized solar cells (DSSCs), respectively, based on CoS nanoparticles on an organized mesoporous SnO2 (om-SnO2) counter electrode. These results correspond to improvements of 14% and 9%, respectively, compared to a conventional Pt counter electrode and are among the highest values reported for Pt-free DSSCs. The om-SnO2 layer plays a pivotal role as a platform to deposit a large amount of highly electrocatalytically active CoS nanoparticles via a facile solvothermal reaction. The om-SnO2 platform with a high porosity, larger pores, and good interconnectivity is derived from a poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) graft copolymer template, which provides not only improved interaction sites for the formation of CoS nanoparticles but also enhanced electron transport. The structural, morphological, chemical, and electrochemical properties of CoS on the om-SnO2 platform are investigated using field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) measurements. The performance enhancement results from the excellent electron transport at the fluorine-doped tin oxide (FTO)/counter electrode/electrolyte interface, reduced resistance at the FTO/CoS interface, and better catalytic reduction at the counter electrode/electrolyte interface.

  17. Facile, substrate-scale growth of mono- and few-layer homogeneous MoS2 films on Mo foils with enhanced catalytic activity as counter electrodes in DSSCs.

    Science.gov (United States)

    Antonelou, Aspasia; Syrrokostas, George; Sygellou, Lamprini; Leftheriotis, George; Dracopoulos, Vassileios; Yannopoulos, Spyros N

    2016-01-29

    The growth of MoS2 films by sulfurization of Mo foils at atmospheric pressure is reported. The growth procedure provides, in a controlled way, mono- and few-layer thick MoS2 films with substrate-scale uniformity across square-centimeter area on commercial foils without any pre- or post-treatment. The prepared few-layer MoS2 films are investigated as counter electrodes for dye-sensitized solar cells (DSSCs) by assessing their ability to catalyse the reduction of I3(-) to I(-) in triiodide redox shuttles. The dependence of the MoS2 catalytic activity on the number of monolayers is explored down to the bilayer thickness, showing performance similar to that of, and stability against corrosion better than, Pt-based nanostructured film. The DSSC with the MoS2-Mo counter electrode yields a photovoltaic energy conversion efficiency of 8.4%, very close to that of the Pt-FTO-based DSSC, i.e. 8.7%. The current results disclose a facile, cost-effective and green method for the fabrication of mechanically robust and chemically stable, few-layer MoS2 on flexible Mo substrates and further demonstrate that efficient counter electrodes for DSSCs can be prepared at thicknesses down to the 1-2 nm scale.

  18. Organic Materials as Electrodes for Li-ion Batteries

    Science.gov (United States)

    2015-09-04

    Several organic compounds were synthesized , characterized and tested in battery configurations. The details are given for each class of materials...batteries. Several organic compounds were synthesized , characterized and tested in battery configurations. The details are given for each class of materials... synthesized , characterized and tested in battery configurations. The details are given below for each class of materials.Various macrocycles, their synthesis

  19. Novel inorganic and organic electrode materials for sustainable and greener Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Tarascon, J.M. [Univ., de Picardie Jules Verne CNRS, Amiens (France). Laboratoire de Reactivite et Chimie des Solides

    2010-07-01

    Rechargeable batteries are among the major technological developments that will have an impact on the commercialization of electric-powered vehicles. Their development relies on advancements in energy storage as well as on the design of better performing and less expensive materials for electrode assemblies. Issues of sustainability must also be taken into consideration when choosing electrode materials for the next generation of batteries. This presentation reported on a study in which LiFePO{sub 4} electrodes were synthesized via eco-efficient hydrothermal/solvothermal processes using latent bases or other bio-related approaches. The recently developed ionothermal approach was successfully applied to prepare materials derived from the olivine-type structure (LiMPO{sub 4}; M=Mn, Co, and Ni) as well as other electrodes having F- in addition to PO{sub 4}{sup 3-} as part of the anionic lattice. A new family of fluorophosphates compounds AMSO{sub 4}F (A= Li, Na; M= 3d metals) having the tavorite-type structure or other derived structures were also synthesized through this study. The most promising electrode was LiFeSO4F, which is based on several chemical elements, making it a serious contender to LiFePO4 for the next generation of Li-ion batteries for automotive applications. However, this electrode is not a sufficient step forward towards the long-term demand for materials sustainability. In contrast, organic electrodes appear as ideal candidates because they can be synthesized from natural organic sources, are biodegradable and are not resource limited. For that reason, this presentation also examined the feasibility of using conjugated dicarboxylates anodes and oxocarbons positive electrodes, for renewable Li-ion batteries.

  20. High-capacity electrode materials for electrochemical energy storage: Role of nanoscale effects

    Indian Academy of Sciences (India)

    Jagjit Nanda; Surendra K Martha; Ramki Kalyanaraman

    2015-06-01

    This review summarizes the current state-of-the art electrode materials used for high-capacity lithium-ion-based batteries and their significant role towards revolutionizing the electrochemical energy storage landscape in the area of consumer electronics, transportation and grid storage application. We discuss the role of nanoscale effects on the electrochemical performance of high-capacity battery electrode materials. Decrease in the particle size of the primary electrode materials from micron to nanometre size improves the ionic and electronic diffusion rates significantly. Nanometre-thick solid electrolyte (such as lithium phosphorous oxynitride) and oxides (such as Al2O3, ZnO, TiO2 etc.) material coatings also improve the interfacial stability and rate capability of a number of battery chemistries. We elucidate these effects in terms of different high-capacity battery chemistries based on intercalation and conversion mechanism.

  1. Nitrogen Doped Macroporous Carbon as Electrode Materials for High Capacity of Supercapacitor

    Directory of Open Access Journals (Sweden)

    Yudong Li

    2017-01-01

    Full Text Available Nitrogen doped carbon materials as electrodes of supercapacitors have attracted abundant attention. Herein, we demonstrated a method to synthesize N-doped macroporous carbon materials (NMC with continuous channels and large size pores carbonized from polyaniline using multiporous silica beads as sacrificial templates to act as electrode materials in supercapacitors. By the nice carbonized process, i.e., pre-carbonization at 400 °C and then pyrolysis at 700/800/900/1000 °C, NMC replicas with high BET specific surface areas exhibit excellent stability and recyclability as well as superb capacitance behavior (~413 F ⋅ g−1 in alkaline electrolyte. This research may provide a method to synthesize macroporous materials with continuous channels and hierarchical pores to enhance the infiltration and mass transfer not only used as electrode, but also as catalyst somewhere micro- or mesopores do not work well.

  2. Recent progress in nickel based materials for high performance pseudocapacitor electrodes

    Science.gov (United States)

    Feng, Liangdong; Zhu, Yufu; Ding, Hongyan; Ni, Chaoying

    2014-12-01

    Nickel based materials have been intensively investigated and considered as good potential electrode materials for pseudocapacitors due to their high theoretical specific capacity values, high chemical and thermal stability, ready availability, environmentally benign nature and lower cost. This review firstly examines recent progress in nickel oxides or nickel hydroxides for high performance pseudocapacitor electrodes. The advances of hybrid electrodes are then assessed to include hybrid systems of nickel based materials with compounds such as carbonaceous materials, metal and transition metal oxides or hydroxides, in which various strategies have been adopted to improve the electrical conductivity of nickel oxides or hydroxides. Furthermore, the energy density and power density of some recently reported NiO, nickel based composites and NiCo2O4 are summarized and discussed. Finally, we provide some perspectives as to the future directions of this intriguing field.

  3. A Viable Electrode Material for Use in Microbial Fuel Cells for Tropical Regions

    Directory of Open Access Journals (Sweden)

    Felix Offei

    2016-01-01

    Full Text Available Electrode materials are critical for microbial fuel cells (MFC since they influence the construction and operational costs. This study introduces a simple and efficient electrode material in the form of palm kernel shell activated carbon (AC obtained in tropical regions. The novel introduction of this material is also targeted at introducing an inexpensive and durable electrode material, which can be produced in rural communities to improve the viability of MFCs. The maximum voltage and power density obtained (under 1000 Ω load using an H-shaped MFC with AC as both anode and cathode electrode material was 0.66 V and 1.74 W/m3, respectively. The power generated by AC was as high as 86% of the value obtained with the extensively used carbon paper. Scanning electron microscopy and Denaturing Gradient Gel Electrophoresis (DGGE analysis of AC anode biofilms confirmed that electrogenic bacteria were present on the electrode surface for substrate oxidation and the formation of nanowires.

  4. Molybdate Based Ceramic Negative-Electrode Materials for Solid Oxide Cells

    DEFF Research Database (Denmark)

    Graves, Christopher R.; Reddy Sudireddy, Bhaskar; Mogensen, Mogens Bjerg

    2010-01-01

    Novel molybdate materials with varying Mo valence were synthesized as possible negative-electrode materials for solid oxide cells. The phase, stability, microstructure and electrical conductivity were characterized. The electrochemical activity for H2O and CO2 reduction and H2 and CO oxidation wa...

  5. Reliability of electrode wear compensation based on material removal per discharge in micro EDM milling

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Tristo, G.; Hansen, Hans Nørgaard

    2013-01-01

    This paper investigates the reliability of workpiece material removal per discharge (MRD) estimation for application in electrode wear compensation based on workpiece material removal. An experimental investigation involving discharge counting and automatic on the machine measurement of removed...... removal simulation tool was developed and validated....

  6. Efficient p-type dye-sensitized solar cells with all-nano-electrodes: NiCo2S4 mesoporous nanosheet counter electrodes directly converted from NiCo2O4 photocathodes

    Science.gov (United States)

    Shi, Zhiwei; Lu, Hao; Liu, Qiong; Cao, Fengren; Guo, Jun; Deng, Kaimo; Li, Liang

    2014-11-01

    We report the successful growth of NiCo2S4 nanosheet films converted from NiCo2O4 nanosheet films on fluorine-doped tin oxide substrates by a low-temperature solution process. Low-cost NiCo2S4 and NiCo2O4 nanosheet films were directly used for replacing conventional Pt and NiO as counter electrodes and photocathodes, respectively, to construct all-nano p-type dye-sensitized solar cells (p-DSSCs) with high performance. Compared to Pt, NiCo2S4 showed higher catalytic activity towards the I-/I3 - redox in electrolyte, resulting in an improved photocurrent density up to 2.989 mA/cm2, which is the highest value in reported p-DSSCs. Present p-DSSCs demonstrated a cell efficiency of 0.248 % that is also comparable with typical NiO-based p-DSSCs.

  7. FLEXIBLE GEIGER COUNTER

    Science.gov (United States)

    Richter, H.G.; Gillespie, A.S. Jr.

    1963-11-12

    A flexible Geiger counter constructed from materials composed of vinyl chloride polymerized with plasticizers or co-polymers is presented. The counter can be made either by attaching short segments of corrugated plastic sleeving together, or by starting with a length of vacuum cleaner hose composed of the above materials. The anode is maintained substantially axial Within the sleeving or hose during tube flexing by means of polystyrene spacer disks or an easily assembled polyethylene flexible cage assembly. The cathode is a wire spiraled on the outside of the counter. The sleeving or hose is fitted with glass end-pieces or any other good insulator to maintain the anode wire taut and to admit a counting gas mixture into the counter. Having the cathode wire on the outside of the counter substantially eliminates the objectional sheath effect of prior counters and permits counting rates up to 300,000 counts per minute. (AEC)

  8. A microwave synthesized CuxS and graphene oxide nanoribbon composite as a highly efficient counter electrode for quantum dot sensitized solar cells

    Science.gov (United States)

    Ghosh, Dibyendu; Halder, Ganga; Sahasrabudhe, Atharva; Bhattacharyya, Sayan

    2016-05-01

    To boost the photoconversion efficiency (PCE) of ever promising quantum dot sensitized solar cells (QDSSCs), and to improve the design of photoanodes, the ability of the counter electrode (CE) to effectively reduce the oxidized electrolyte needs special attention. A composite of a 15 wt% graphene oxide nanoribbon (GOR), obtained by unzipping multi-walled carbon nanotubes (MWCNTs), and CuxS intersecting hexagonal nanoplates, synthesized by a low cost, facile and scalable microwave synthesis route, is reported as a fascinating CE for QDSSCs. The best performing Cu1.18S-GOR CE could notably achieve a record PCE of ~3.55% for CdS sensitized QDSSCs, ~5.42% for in situ deposited CdS/CdSe co-sensitized QDSSCs and ~6.81% for CdTe/CdS/CdS dual sensitized QDSSCs, apart from increasing the PCE of previously reported QDSSCs. A systematic investigation of the CE design revealed the high electrocatalytic activity of GOR due to the presence of organic functional groups, graphitic edge sites and a quasi-one-dimensional (quasi-1D) structure, which increases the interfacial charge transfer kinetics from the CE to the polysulfide electrolyte. The highly stable Cu1.18S-GOR CE has the added advantage of a favourable energy band alignment with the redox potential of the polysulfide electrolyte, which reduces the loss of charge carriers and thus can increase the PCE of QDSSCs.To boost the photoconversion efficiency (PCE) of ever promising quantum dot sensitized solar cells (QDSSCs), and to improve the design of photoanodes, the ability of the counter electrode (CE) to effectively reduce the oxidized electrolyte needs special attention. A composite of a 15 wt% graphene oxide nanoribbon (GOR), obtained by unzipping multi-walled carbon nanotubes (MWCNTs), and CuxS intersecting hexagonal nanoplates, synthesized by a low cost, facile and scalable microwave synthesis route, is reported as a fascinating CE for QDSSCs. The best performing Cu1.18S-GOR CE could notably achieve a record PCE of ~3

  9. [Growth behavior of spiral ganglion explants on cochlear implant electrodes and their materials].

    Science.gov (United States)

    Hansen, S; Mlynski, R; Volkenstein, S; Stark, T; Schwaab, M; Dazert, S; Brors, D

    2009-04-01

    With the increasing use of cochlear implants (CIs), the insertion of alloplastic material into the inner ear is nowadays an established treatment for severe to profound hearing loss in children and adults. Beyond its widespread use, the biocompatibility of the CI electrode and its interaction with the neural structures of the cochlea is not yet established. To investigate the survival and growth behavior of spiral ganglion neurons on different CI materials, spiral ganglion explants from newborn rats were cultured on silicone and platinum, on a surface combination of silicone and platinum, and, finally, on a CI electrode. The results of this study indicate that the growth of spiral ganglion neurons in vitro is strongly influenced by the different materials and their arrangement, with platinum exhibiting the highest degree of biocompatibility with respect to neurite extension. Level differences in the surface structure between silicone and platinum lead to inhibition of neurite outgrowth. Furthermore, the culturing of spiral ganglion explants on a CI electrode leads to neurite sprouting toward the electrodes made of platinum. The biocompatibility of CI materials with spiral ganglion neurons was shown in this study, but it differs with different CI materials. Besides the material itself, the arrangement of the materials can affect the neurite extension.

  10. In-situ growth of antimony sulfide in carbon nanoparticle matrix: Enhanced electrocatalytic activity as counter electrode in dye-sensitized solar cells

    Science.gov (United States)

    Sun, Panpan; Zhang, Ming; Ai, Changzhi; Wu, Zhixin; Lu, Shuang; Zhang, Xintong; Huang, Niu; Sun, Yihua; Sun, Xiaohua

    2016-07-01

    Considering the undesirable electrocatalytic activity toward I-/I3- redox system of prinstine antimony sulfide (Sb2S3) fabricated with the existing conditions, a mesoporous carbon nanoparticle film (CNP) is introduced here for in-situ growth of Sb2S3 to construct a Sb2S3@CNP hybrid catalyst. Based on a Sb-thiourea precursor solution, in-situ growth of Sb2S3 can be achieved via solution deposition (denoted as Sb2S3@CNP-S) as well as atmospheric pressure thermal evaporation (denoted as Sb2S3@CNP-T) in CNP matrix. Structural characterizations indicate that Sb2S3 particles have well dispersed in the pores of CNP matrix. Because of the introduction of porous and conductive CNP matrix to support Sb2S3, the hybrid catalyst exhibits lower charge transfer resistance at the catalyst/electrolyte interface and higher electrocatalytic activity. When used as counter electrode (CE) for dye-sensitized solar cells (DSSCs), devices using Sb2S3@CNP hybrid catalyst as CE produce fill factor of 67.6% and 66.3%, which is significantly higher than that using pristine Sb2S3 fabricated in our previous work (52.8%). Finally, the corresponding power conversion efficiencies reach 6.69% (Sb2S3@CNP-S) and 6.24% (Sb2S3@CNP-T), respectively, which are comparable to that using Pt CE measured under the same conditions (6.74%).

  11. LDHs as electrode materials for electrochemical detection and energy storage: supercapacitor, battery and (bio)-sensor.

    Science.gov (United States)

    Mousty, Christine; Leroux, Fabrice

    2012-11-01

    From an exhaustive overview based on applicative academic literature and patent domain, the relevance of Layered Double Hydroxide (LDHs) as electrode materials for electrochemical detection of organic molecules having environmental or health impact and energy storage is evaluated. Specifically the focus is driven on their application as supercapacitor, alkaline or lithium battery and (bio)-sensor. Inherent to the high versatility of their chemical composition, charge density, anion exchange capability, LDH-based materials are extensively studied and their performances for such applications are reported. Indeed the analytical characteristics (sensitivity and detection limit) of LDH-based electrodes are scrutinized, and their specific capacity or capacitance as electrode battery or supercapacitor materials, are detailed.

  12. Combination of a novel electrode material and artificial mediators to enhance power generation in an MFC.

    Science.gov (United States)

    Taskan, Ergin; Ozkaya, Bestamin; Hasar, Halil

    2015-01-01

    This study focuses on two main aspects: developing a novel cost-effective electrode material and power production from domestic wastewater using three different mediators. Methylene blue (MB), neutral red (NR) and 2-hydroxy-1,4-naphthoquinone (HNQ) were selected as electrode mediators with different concentrations. A tin-coated copper mesh electrode was tested as anode electrode. Maximum power density of the microbial fuel cell (MFC) with 300 μM MB was 636 mW/m². Optimal mediator concentrations with respect to the achieved maximum power output for MB, NR and HNQ were 300 μM, 200 μM and 50 μM, respectively. The results demonstrate that tin-coated copper mesh showed a higher biocompatibility and electrical conductivity.

  13. Electrical characterization of conductive textile materials and its evaluation as electrodes for venous occlusion plethysmography.

    Science.gov (United States)

    Goy, C B; Dominguez, J M; Gómez López, M A; Madrid, R E; Herrera, M C

    2013-08-01

    The ambulatory monitoring of biosignals involves the use of sensors, electrodes, actuators, processing tools and wireless communication modules. When a garment includes these elements with the purpose of recording vital signs and responding to specific situations it is call a 'Smart Wearable System'. Over the last years several authors have suggested that conductive textile material (e-textiles) could perform as electrode for these systems. This work aims at implementing an electrical characterization of e-textiles and an evaluation of their ability to act as textile electrodes for lower extremity venous occlusion plethysmography (LEVOP). The e-textile electrical characterization is carried out using two experimental set-ups (in vitro evaluation). Besides, LEVOP records are obtained from healthy volunteers (in vivo evaluation). Standard Ag/AgCl electrodes are used for comparison in all tests. Results shown that the proposed e-textiles are suitable for LEVOP recording and a good agreement between evaluations (in vivo and in vitro) is found.

  14. Carbon Paste Electrodes Made from Different Carbonaceous Materials: Application in the Study of Antioxidants

    Science.gov (United States)

    Apetrei, Constantin; Apetrei, Irina Mirela; De Saja, Jose Antonio; Rodriguez-Mendez, Maria Luz

    2011-01-01

    This work describes the sensing properties of carbon paste electrodes (CPEs) prepared from three different types of carbonaceous materials: graphite, carbon microspheres and carbon nanotubes. The electrochemical responses towards antioxidants including vanillic acid, catechol, gallic acid, l-ascorbic acid and l-glutathione have been analyzed and compared. It has been demonstrated that the electrodes based on carbon microspheres show the best performances in terms of kinetics and stability, whereas G-CPEs presented the smallest detection limit for all the antioxidants analyzed. An array of electrodes has been constructed using the three types of electrodes. As demonstrated by means of Principal Component Analysis, the system is able to discriminate among antioxidants as a function of their chemical structure and reactivity. PMID:22319354

  15. Surface and interface engineering of electrode materials for lithium-ion batteries.

    Science.gov (United States)

    Wang, Kai-Xue; Li, Xin-Hao; Chen, Jie-Sheng

    2015-01-21

    Lithium-ion batteries are regarded as promising energy storage devices for next-generation electric and hybrid electric vehicles. In order to meet the demands of electric vehicles, considerable efforts have been devoted to the development of advanced electrode materials for lithium-ion batteries with high energy and power densities. Although significant progress has been recently made in the development of novel electrode materials, some critical issues comprising low electronic conductivity, low ionic diffusion efficiency, and large structural variation have to be addressed before the practical application of these materials. Surface and interface engineering is essential to improve the electrochemical performance of electrode materials for lithium-ion batteries. This article reviews the recent progress in surface and interface engineering of electrode materials including the increase in contact interface by decreasing the particle size or introducing porous or hierarchical structures and surface modification or functionalization by metal nanoparticles, metal oxides, carbon materials, polymers, and other ionic and electronic conductive species. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Grafted, cross-linked carbon black as a double-layer capacitor electrode material

    Energy Technology Data Exchange (ETDEWEB)

    Richner, R.; Mueller, S.; Wokaun, A.

    2001-03-01

    Isocyanate prepolymers readily react with oxidic functional groups on carbon black. On carbon black grafted with diisocyanates, reactive isocyanate groups are available for cross-linking to a polyurethane system. This cross-linked carbon black was considered as a new active material for electrochemical electrodes. Active material for electric double-layer capacitor electrodes was produced which had values of specific capacitance of up to 200 F/g. Cross-linking efficiencies of up to 58 % of the polymers utilised were achieved. (author)

  17. High Reversibility of Soft Electrode Materials in All-solid-state Batteries

    Directory of Open Access Journals (Sweden)

    Atsushi eSakuda

    2016-05-01

    Full Text Available All-solid-state batteries using inorganic solid electrolytes (SEs are considered to be ideal batteries for electric vehicles (EVs and plug-in hybrid electric vehicles (PHEVs because they are potentially safer than conventional lithium-ion batteries (LIBs. In addition, all-solid-state batteries are expected to have long battery lives owing to the inhibition of chemical side reactions because only lithium ions move through the typically used inorganic SEs. The development of high-energy (more than 300 Wh kg-1 secondary batteries has been eagerly anticipated for years. The application of high-capacity electrode active materials is essential for fabricating such batteries. Recently, we proposed metal polysulfides as new electrode materials. These materials show higher conductivity and density than sulfur, which is advantageous for fabricating batteries with relatively higher energy density. Lithium niobium sulfides, such as Li3NbS4, have relatively high density, conductivity, and rate capability among metal polysulfide materials, and batteries with these materials have capacities high enough to potentially exceed the gravimetric energy density of conventional LIBs.Favorable solid-solid contact between the electrode and electrolyte particles is a key factor for fabricating high performance all-solid-state batteries. Conventional oxide-based positive electrode materials tend to be given rise to cracks during fabrication and/or charge-discharge processes. Here we report all-solid-state cells using lithium niobium sulfide as a positive electrode material, where favorable solid-solid contact was established by using lithium sulfide electrode materials because of their high processability. Cracks were barely observed in the electrode particles in the all-solid-state cells before or after charging and discharging with a high capacity of approx. 400 mAh g-1, suggesting that the lithium niobium sulfide electrode charged and discharged without experiencing

  18. Electrochemical surface plasmon resonance sensor based on two-electrode configuration

    Science.gov (United States)

    Zhang, Bing; Li, Yazhuo; Dong, Wei; Wen, Yizhang; Pang, Kai; Zhan, Shuyue; Wang, Xiaoping

    2016-10-01

    To obtain detailed information about electrochemistry reactions, a two-electrode electrochemical surface plasmon resonance (EC-SPR) sensor has been proposed. We describe the theory of potential modulation for this novel sensor and determine the factors that can change the SPR resonance angle. The reference electrode in three-electrode configuration was eliminated, and comparing with several other electrode materials, activated carbon (AC) is employed as the suitable counter electrode for its potential stability. Just like three-electrode configuration, the simpler AC two-electrode system can also obtain detailed information about the electrochemical reactions.

  19. Investigation of materials for inert electrodes in aluminum electrodeposition cells

    Energy Technology Data Exchange (ETDEWEB)

    Haggerty, J. S.; Sadoway, D. R.

    1987-09-14

    Work was divided into major efforts. The first was the growth and characterization of specimens; the second was Hall cell performance testing. Cathode and anode materials were the subject of investigation. Preparation of specimens included growth of single crystals and synthesis of ultra high purity powders. Special attention was paid to ferrites as they were considered to be the most promising anode materials. Ferrite anode corrosion rates were studied and the electrical conductivities of a set of copper-manganese ferrites were measured. Float Zone, Pendant Drop Cryolite Experiments were undertaken because unsatisfactory choices of candidate materials were being made on the basis of a flawed set of selection criteria applied to an incomplete and sometimes inaccurate data base. This experiment was then constructed to determine whether the apparatus used for float zone crystal growth could be adapted to make a variety of important based melts and their interactions with candidate inert anode materials. The third major topic was Non Consumable Anode (Data Base, Candidate Compositions), driven by our perception that the basis for prior selection of candidate materials was inadequate. Results are presented. 162 refs., 39 figs., 18 tabs.

  20. Recent Development of Advanced Electrode Materials by Atomic Layer Deposition for Electrochemical Energy Storage.

    Science.gov (United States)

    Guan, Cao; Wang, John

    2016-10-01

    Electrode materials play a decisive role in almost all electrochemical energy storage devices, determining their overall performance. Proper selection, design and fabrication of electrode materials have thus been regarded as one of the most critical steps in achieving high electrochemical energy storage performance. As an advanced nanotechnology for thin films and surfaces with conformal interfacial features and well controllable deposition thickness, atomic layer deposition (ALD) has been successfully developed for deposition and surface modification of electrode materials, where there are considerable issues of interfacial and surface chemistry at atomic and nanometer scale. In addition, ALD has shown great potential in construction of novel nanostructured active materials that otherwise can be hardly obtained by other processing techniques, such as those solution-based processing and chemical vapor deposition (CVD) techniques. This review focuses on the recent development of ALD for the design and delivery of advanced electrode materials in electrochemical energy storage devices, where typical examples will be highlighted and analyzed, and the merits and challenges of ALD for applications in energy storage will also be discussed.

  1. Preparation of material to control precision of calcium selective electrodes.

    Science.gov (United States)

    Fyffe, J A; Jenkins, A S; Bolland, C J; Dryburgh, F J; Gardner, M D

    1981-03-01

    A simple procedure is described for the preparation of a stable precision quality control material for use in the measurement of level of ionised calcium in serum at or near the reference range. Repeat analyses on a Nova 2 ionised calcium analyser of serum pools stored at different temperatures over a period of three months showed coefficients of variation less of less than 4%.

  2. Novel Nanostructured Electrodes Obtained by Pyrolysis of Composite Polymeric Materials

    DEFF Research Database (Denmark)

    Amato, Letizia; Schulte, Lars; Heiskanen, Arto

    2015-01-01

    In this work, we compare pyrolyzed carbon derived from the photoresist SU‐8 alone or in combination with polystyrene and poly(styrene)‐block‐poly(dimethylsiloxane) copolymer (PS‐b‐PDMS), to be used as novel materials for micro‐ and nanoelectrodes. The pyrolyzed carbon films are evaluated with sca...

  3. Microbial community structure of different electrode materials in constructed wetland incorporating microbial fuel cell.

    Science.gov (United States)

    Wang, Junfeng; Song, Xinshan; Wang, Yuhui; Abayneh, Befkadu; Ding, Yi; Yan, Denghua; Bai, Junhong

    2016-12-01

    The microbial fuel cell coupled with constructed wetland (CW-MFC) microcosms were operated under fed-batch mode for evaluating the effect of electrode materials on bioelectricity generation and microbial community composition. Experimental results indicated that the bioenergy output in CW-MFC increased with the substrate concentration; maximum average voltage (177mV) was observed in CW-MFC with carbon fiber felt (CFF). In addition, the four different materials resulted in the formation of significantly different microbial community distribution around the anode electrode. The relative abundance of Proteobacteria in CFF and foamed nickel (FN) was significantly higher than that in stainless steel mesh (SSM) and graphite rod (GR) samples. Notably, the findings indicate that CW-MFC utilizing FN anode electrode could apparently improve relative abundance of Dechloromonas, which has been regarded as a denitrifying and phosphate accumulating microorganism.

  4. Carbonized chicken eggshell membranes with 3D architectures as high-performance electrode materials for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhi; Zhang, Li; Amirkhiz, Babak Shalchi; Tan, Xuehai; Xu, Zhanwei; Wang, Huanlei; Olsen, Brian C.; Holt, Chris M.B.; Mitlin, David [Chemical and Materials Engineering, University of Alberta, Edmonton, AB (Canada); National Institute for Nanotechnology (NINT), NRC, Edmonton, AB (Canada)

    2012-04-15

    Supercapacitor electrode materials are synthesized by carbonizing a common livestock biowaste in the form of chicken eggshell membranes. The carbonized eggshell membrane (CESM) is a three-dimensional macroporous carbon film composed of interwoven connected carbon fibers containing around 10 wt% oxygen and 8 wt% nitrogen. Despite a relatively low surface area of 221 m{sup 2} g{sup -1}, exceptional specific capacitances of 297 F g{sup -1} and 284 F g{sup -1} are achieved in basic and acidic electrolytes, respectively, in a 3-electrode system. Furthermore, the electrodes demonstrate excellent cycling stability: only 3% capacitance fading is observed after 10 000 cycles at a current density of 4 A g{sup -1}. These very attractive electrochemical properties are discussed in the context of the unique structure and chemistry of the material. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Layered double hydroxide materials coated carbon electrode: New challenge to future electrochemical power devices

    Science.gov (United States)

    Djebbi, Mohamed Amine; Braiek, Mohamed; Namour, Philippe; Ben Haj Amara, Abdesslem; Jaffrezic-Renault, Nicole

    2016-11-01

    Layered double hydroxides (LDHs) have been widely used in the past years due to their unique physicochemical properties and promising applications in electroanalytical chemistry. The present paper is going to focus exclusively on magnesium-aluminum and zinc-aluminum layered double hydroxides (MgAl & ZnAl LDHs) in order to investigate the property and structure of active cation sites located within the layer structure. The MgAl and ZnAl LDH nanosheets were prepared by the constant pH co-precipitation method and uniformly supported on carbon-based electrode materials to fabricate an LDH electrode. Characterization by powder x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy revealed the LDH form and well-crystallized materials. Wetting surface properties (hydrophilicity and hydrophobicity) of both prepared LDHs were recorded by contact angle measurement show hydrophilic character and basic property. The electrochemical performance of these hybrid materials was investigated by mainly cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry techniques to identify the oxidation/reduction processes at the electrode/electrolyte interface and the effect of the divalent metal cations in total reactivity. The hierarchy of the modified electrode proves that the electronic conductivity of the bulk material is considerably dependent on the divalent cation and affects the limiting parameter of the overall redox process. However, MgAl LDH shows better performance than ZnAl LDH, due to the presence of magnesium cations in the layers. Following the structural, morphological and electrochemical behavior studies of both synthesized LDHs, the prepared LDH modified electrodes were tested through microbial fuel cell configuration, revealing a remarkable, potential new pathway for high-performance and cost-effective electrode use in electrochemical power devices.

  6. Graphene-carbon nanotube hybrid materials and use as electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Tour, James M.; Zhu, Yu; Li, Lei; Yan, Zheng; Lin, Jian

    2016-09-27

    Provided are methods of making graphene-carbon nanotube hybrid materials. Such methods generally include: (1) associating a graphene film with a substrate; (2) applying a catalyst and a carbon source to the graphene film; and (3) growing carbon nanotubes on the graphene film. The grown carbon nanotubes become covalently linked to the graphene film through carbon-carbon bonds that are located at one or more junctions between the carbon nanotubes and the graphene film. In addition, the grown carbon nanotubes are in ohmic contact with the graphene film through the carbon-carbon bonds at the one or more junctions. The one or more junctions may include seven-membered carbon rings. Also provided are the formed graphene-carbon nanotube hybrid materials.

  7. Graphene-carbon nanotube hybrid materials and use as electrodes

    Science.gov (United States)

    Tour, James M.; Zhu, Yu; Li, Lei; Yan, Zheng; Lin, Jian

    2016-09-27

    Provided are methods of making graphene-carbon nanotube hybrid materials. Such methods generally include: (1) associating a graphene film with a substrate; (2) applying a catalyst and a carbon source to the graphene film; and (3) growing carbon nanotubes on the graphene film. The grown carbon nanotubes become covalently linked to the graphene film through carbon-carbon bonds that are located at one or more junctions between the carbon nanotubes and the graphene film. In addition, the grown carbon nanotubes are in ohmic contact with the graphene film through the carbon-carbon bonds at the one or more junctions. The one or more junctions may include seven-membered carbon rings. Also provided are the formed graphene-carbon nanotube hybrid materials.

  8. Negative capacitance for various electrode materials in organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Roesch, Roland; Hoppe, Harald [Institute of Physics, TU Ilmenau (Germany); Pivrikas, Almantas; Sariciftci, Niyazi Serdar [LIOS, Johannes Kepler University Linz (Austria)

    2009-07-01

    Electrical behaviour of bulk heterojunction polymer solar cells is strongly influenced by their contacts. Charge carrier injection/extraction at contact-active layer interface depends on type of contact. In the literature different models - Schottky-contact, thermionic injection and injection via hopping processes - for the cathode contact are discussed. We use different contact materials and investigate the resulting capacitance via impedance spectroscopy, a non-invasive technique for electrical analysis. We observe a dependence of Negative Capacitance on contact type.

  9. Electrochemistry of Inorganic Nanocrystalline Electrode Materials for Lithium Batteries

    Directory of Open Access Journals (Sweden)

    C. W. Kwon

    2003-01-01

    much different from that of traditional crystalline ones because of their significant ‘surface effects’. In connection with that, the nanocrystalline cathode materials are reported to have an enhanced electrochemical activity when the first significative electrochemical step is insertion of Li ions (discharge process. The “electrochemical grafting” concept will be given as a plausible explanation. As illustrative examples, electrochemical behaviors of nanocrystalline manganese oxydes are presented.

  10. Speci﬿c contact resistance of phase change materials to metal electrode

    NARCIS (Netherlands)

    Roy, Deepu; in 't Zandt, Micha A.A.; Wolters, Robertus A.M.

    2010-01-01

    For phase change random access memory (PCRAM) cells, it is important to know the contact resistance of phase change materials (PCMs) to metal electrodes at the contacts. In this letter, we report the systematic determination of the speci﬿c contact resistance (Ͽc ) of doped Sb2Te and Ge2Sb2Te5 to TiW

  11. Characterization of Electrode Materials for Lithium Ion and Sodium Ion Batteries using Synchrotron Radiation Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, Apurva; Stanford Synchrotron Radiation Lightsource; Doeff, Marca M.; Chen, Guoying; Cabana, Jordi; Richardson, Thomas J.; Mehta, Apurva; Shirpour, Mona; Duncan, Hugues; Kim, Chunjoong; Kam, Kinson C.; Conry, Thomas

    2013-04-30

    We describe the use of synchrotron X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) techniques to probe details of intercalation/deintercalation processes in electrode materials for Li ion and Na ion batteries. Both in situ and ex situ experiments are used to understand structural behavior relevant to the operation of devices.

  12. Recent Advances in Polymeric Materials Used as Electron Mediators and Immobilizing Matrices in Developing Enzyme Electrodes

    Directory of Open Access Journals (Sweden)

    Mambo Moyo

    2012-01-01

    Full Text Available Different classes of polymeric materials such as nanomaterials, sol-gel materials, conducting polymers, functional polymers and biomaterials have been used in the design of sensors and biosensors. Various methods have been used, for example from direct adsorption, covalent bonding, crossing-linking with glutaraldehyde on composites to mixing the enzymes or use of functionalized beads for the design of sensors and biosensors using these polymeric materials in recent years. It is widely acknowledged that analytical sensing at electrodes modified with polymeric materials results in low detection limits, high sensitivities, lower applied potential, good stability, efficient electron transfer and easier immobilization of enzymes on electrodes such that sensing and biosensing of environmental pollutants is made easier. However, there are a number of challenges to be addressed in order to fulfill the applications of polymeric based polymers such as cost and shortening the long laboratory synthetic pathways involved in sensor preparation. Furthermore, the toxicological effects on flora and fauna of some of these polymeric materials have not been well studied. Given these disadvantages, efforts are now geared towards introducing low cost biomaterials that can serve as alternatives for the development of novel electrochemical sensors and biosensors. This review highlights recent contributions in the development of the electrochemical sensors and biosensors based on different polymeric material. The synergistic action of some of these polymeric materials and nanocomposites imposed when combined on electrode during sensing is discussed.

  13. Validation of a procedure for the analysis of (226)Ra in naturally occurring radioactive materials using a liquid scintillation counter.

    Science.gov (United States)

    Kim, Hyuncheol; Jung, Yoonhee; Ji, Young-Yong; Lim, Jong-Myung; Chung, Kun Ho; Kang, Mun Ja

    2017-01-01

    An analytical procedure for detecting (226)Ra in naturally occurring radioactive materials (NORMs) using a liquid scintillation counter (LSC) was developed and validated with reference materials (zircon matrix, bauxite matrix, coal fly ash, and phosphogypsum) that represent typical NORMs. The (226)Ra was released from samples by a fusion method and was separated using sulfate-coprecipitation. Next, a (222)Rn-emanation technique was applied for the determination of (226)Ra. The counting efficiency was 238 ± 8% with glass vials. The recovery for the reference materials was 80 ± 11%. The linearity of the method was tested with different masses of zircon matrix reference materials. Using 15 types of real NORMs, including raw materials and by-products, this LSC method was compared with γ-spectrometry, which had already been validated for (226)Ra analysis. The correlation coefficient for the results from the LSC method and γ-spectrometry was 0.993 ± 0.058.

  14. The Study of Metal Sulfide as Efficient Counter Electrodes on the Performances of CdS/CdSe/ZnS-co-sensitized Hierarchical TiO2 Sphere Quantum Dot Solar Cells

    Science.gov (United States)

    Buatong, Nattha; Tang, I.-Ming; Pon-On, Weeraphat

    2017-03-01

    The effects of using different counter electrode metal sulfides on the performances of solar cells made with CdS/CdSe/ZnS quantum dots co-sensitized onto hierarchical TiO2 spheres (HTSs) used as photo-electrode are reported. The HTS in the QDSSCs is composed of an assembly of numerous TiO2 spheres made by the solvolthermal method. The photoelectrical performance of HTS/CdS/CdSe/ZnS coupled to CuS or to Cu2ZnSn(S1 - x Se x )4 with x = 0, 0.5, or 1.0 counter electrodes (CEs) were compared to those coupled to Pt CE. The HTS/CdS/CdSe/ZnS coupled to the CuS CE showed the highest power conversion efficiency η (of 3.46%). The efficiencies η of 1.88, 2.64, and 2.06% were obtained for CZTS ( x = 0), CZTS0.5Se0.5 ( x = 0.5), and CZTSe ( x = 1), respectively. These are significantly higher than those using a standard Pt CE ( η = 0.37%). These higher efficiencies are the results of the higher electrocatalytic activities when the metal sulfide CEs are used.

  15. The Study of Metal Sulfide as Efficient Counter Electrodes on the Performances of CdS/CdSe/ZnS-co-sensitized Hierarchical TiO2 Sphere Quantum Dot Solar Cells.

    Science.gov (United States)

    Buatong, Nattha; Tang, I-Ming; Pon-On, Weeraphat

    2017-12-01

    The effects of using different counter electrode metal sulfides on the performances of solar cells made with CdS/CdSe/ZnS quantum dots co-sensitized onto hierarchical TiO2 spheres (HTSs) used as photo-electrode are reported. The HTS in the QDSSCs is composed of an assembly of numerous TiO2 spheres made by the solvolthermal method. The photoelectrical performance of HTS/CdS/CdSe/ZnS coupled to CuS or to Cu2ZnSn(S1 - x Se x )4 with x = 0, 0.5, or 1.0 counter electrodes (CEs) were compared to those coupled to Pt CE. The HTS/CdS/CdSe/ZnS coupled to the CuS CE showed the highest power conversion efficiency η (of 3.46%). The efficiencies η of 1.88, 2.64, and 2.06% were obtained for CZTS (x = 0), CZTS0.5Se0.5 (x = 0.5), and CZTSe (x = 1), respectively. These are significantly higher than those using a standard Pt CE (η = 0.37%). These higher efficiencies are the results of the higher electrocatalytic activities when the metal sulfide CEs are used.

  16. Reliable reference electrodes for lithium-ion batteries

    KAUST Repository

    La Mantia, F.

    2013-06-01

    Despite the high attention drawn to the lithium-ion batteries by the scientific and industrial community, most of the electrochemical characterization is carried out using poor reference electrodes or even no reference electrode. In this case, the performances of the active material are inaccurate, especially at high current densities. In this work we show the error committed in neglecting the polarizability of lithium counter electrodes, and we propose two reference electrodes to use in organic electrolytes based on lithium salts, namely Li4Ti5O12 and LiFePO 4. In particular, it was observed that, the polarizability of the metallic lithium counter electrode has a relevant stochastic component, which renders measurements at high current densities (above 1 mA·cm - 2) in two electrode cells non reproducible.

  17. The Science of Electrode Materials for Lithium Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Fultz, Brent

    2007-03-15

    Rechargeable lithium batteries continue to play the central role in power systems for portable electronics, and could play a role of increasing importance for hybrid transportation systems that use either hydrogen or fossil fuels. For example, fuel cells provide a steady supply of power, whereas batteries are superior when bursts of power are needed. The National Research Council recently concluded that for dismounted soldiers "Among all possible energy sources, hybrid systems provide the most versatile solutions for meeting the diverse needs of the Future Force Warrior. The key advantage of hybrid systems is their ability to provide power over varying levels of energy use, by combining two power sources." The relative capacities of batteries versus fuel cells in a hybrid power system will depend on the capabilities of both. In the longer term, improvements in the cost and safety of lithium batteries should lead to a substantial role for electrochemical energy storage subsystems as components in fuel cell or hybrid vehicles. We have completed a basic research program for DOE BES on anode and cathode materials for lithium batteries, extending over 6 years with a 1 year phaseout period. The emphasis was on the thermodynamics and kinetics of the lithiation reaction, and how these pertain to basic electrochemical properties that we measure experimentally — voltage and capacity in particular. In the course of this work we also studied the kinetic processes of capacity fade after cycling, with unusual results for nanostructued Si and Ge materials, and the dynamics underlying electronic and ionic transport in LiFePO4. This document is the final report for this work.

  18. Electrosynthesis and catalytic activity of polymer-nickel particles composite electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Melki, Tahar; Zouaoui, Ahmed; Bendemagh, Barkahoum [Universite Ferhat Abbas, Setif (Algeria). Faculte des Sciences de l' Ingenieur. Dept. du Tronc Commun; Oliveira, Ione M.F. de; Oliveira, Gilver F. de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Quimica; Lepretre, Jean-Claude [UMR-5631 CNRS-INPG-UJF, St. Martin d' Heres Cedex (France). Lab. d' Electrochimie et de Physicochimie des Materiaux et Interfaces; Bucher, Christophe; Mou tet, Jean-Claude [Universite Joseph Fourier Grenoble 1 (France). Dept. de Chimie Moleculaire], e-mail: Jean-Claude.Moutet@ujf-grenoble.fr

    2009-07-01

    Nickel-polymer composite electrode materials have been synthesized using various strategies, all comprising the electrochemical reduction of nickel(II) cations or complexes, incorporated by either ion-exchange or complexation into various poly(pyrrole-carboxylate) thin films coated by oxidative electropolymerization onto carbon electrodes. The electrocatalytic activity and the stability of the different composites have been then evaluated in the course of the electrocatalytic hydrogenation of ketones and enones in aqueous electrolytes. The best results were obtained using nickel-polymer composites synthesized by electroreduction of nickel(II) ions complexed into polycarboxylate films, which are characterized by a high catalytic activity and a good operational stability. (author)

  19. Layered double hydroxide materials coated carbon electrode: New challenge to future electrochemical power devices

    Energy Technology Data Exchange (ETDEWEB)

    Djebbi, Mohamed Amine, E-mail: mohamed.djebbi@etu.univ-lyon1.fr [Institut des Sciences Analytiques UMR CNRS 5280, Université Claude Bernard-Lyon 1, 5 rue de la Doua, 69100 Villeurbanne (France); Laboratoire de Physique des Matériaux Lamellaires et Nano-Matériaux Hybrides, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Bizerte (Tunisia); Braiek, Mohamed [Institut des Sciences Analytiques UMR CNRS 5280, Université Claude Bernard-Lyon 1, 5 rue de la Doua, 69100 Villeurbanne (France); Namour, Philippe [Institut des Sciences Analytiques UMR CNRS 5280, Université Claude Bernard-Lyon 1, 5 rue de la Doua, 69100 Villeurbanne (France); Irstea, 5 rue de la Doua, 69100 Villeurbanne (France); Ben Haj Amara, Abdesslem [Laboratoire de Physique des Matériaux Lamellaires et Nano-Matériaux Hybrides, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Bizerte (Tunisia); Jaffrezic-Renault, Nicole [Institut des Sciences Analytiques UMR CNRS 5280, Université Claude Bernard-Lyon 1, 5 rue de la Doua, 69100 Villeurbanne (France)

    2016-11-15

    Highlights: • MgAl and ZnAl LDH nanosheets were chemically synthesized and deposited over carbon electrode materials. • Catalytic performance of both LDHs was investigated for Fe(II) reduction reaction. • Satisfactory results have been achieved with the MgAl LDH material. • MgAl and ZnAl LDH modified carbon felt were applied in MFC as an efficient anode catalyst. • The LDH-modified anode significantly increased power performance of MFC. - Abstract: Layered double hydroxides (LDHs) have been widely used in the past years due to their unique physicochemical properties and promising applications in electroanalytical chemistry. The present paper is going to focus exclusively on magnesium-aluminum and zinc-aluminum layered double hydroxides (MgAl & ZnAl LDHs) in order to investigate the property and structure of active cation sites located within the layer structure. The MgAl and ZnAl LDH nanosheets were prepared by the constant pH co-precipitation method and uniformly supported on carbon-based electrode materials to fabricate an LDH electrode. Characterization by powder x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy revealed the LDH form and well-crystallized materials. Wetting surface properties (hydrophilicity and hydrophobicity) of both prepared LDHs were recorded by contact angle measurement show hydrophilic character and basic property. The electrochemical performance of these hybrid materials was investigated by mainly cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry techniques to identify the oxidation/reduction processes at the electrode/electrolyte interface and the effect of the divalent metal cations in total reactivity. The hierarchy of the modified electrode proves that the electronic conductivity of the bulk material is considerably dependent on the divalent cation and affects the limiting parameter of the overall redox process. However

  20. Nanostructured core-shell electrode materials for electrochemical capacitors

    Science.gov (United States)

    Jiang, Long-bo; Yuan, Xing-zhong; Liang, Jie; Zhang, Jin; Wang, Hou; Zeng, Guang-ming

    2016-11-01

    Core-shell nanostructure represents a unique system for applications in electrochemical energy storage devices. Owing to the unique characteristics featuring high power delivery and long-term cycling stability, electrochemical capacitors (ECs) have emerged as one of the most attractive electrochemical storage systems since they can complement or even replace batteries in the energy storage field, especially when high power delivery or uptake is needed. This review aims to summarize recent progress on core-shell nanostructures for advanced supercapacitor applications in view of their hierarchical architecture which not only create the desired hierarchical porous channels, but also possess higher electrical conductivity and better structural mechanical stability. The core-shell nanostructures include carbon/carbon, carbon/metal oxide, carbon/conducting polymer, metal oxide/metal oxide, metal oxide/conducting polymer, conducting polymer/conducting polymer, and even more complex ternary core-shell nanoparticles. The preparation strategies, electrochemical performances, and structural stabilities of core-shell materials for ECs are summarized. The relationship between core-shell nanostructure and electrochemical performance is discussed in detail. In addition, the challenges and new trends in core-shell nanomaterials development have also been proposed.

  1. Facile synthesis of polypyrrole nanowires for high-performance supercapacitor electrode materials

    Directory of Open Access Journals (Sweden)

    Junhong Zhao

    2016-06-01

    Full Text Available Polypyrrole nanowires are facile synthesized under a mild condition with FeCl3 as an oxidant. Polypyrrole nanowires with the width of 120 nm form many nanogaps or pores due to the intertwined nanostructures. More importantly, PPy nanowires were further applied for supercapacitor electrode materials. After electrochemical testing, it was observed that the PPy nanowire based electrode showed a large specific capacitance (420 F g−1, 1.5 A g−1 and good rate capability (272 F g−1, 18.0 A g−1, which is larger than that of most of published results. The as-prepared electrode can work well even after 8000 cycles at 1.5 A g−1.

  2. Facile synthesis of polypyrrole nanowires for high-performance supercapacitor electrode materials

    Institute of Scientific and Technical Information of China (English)

    Junhong Zhao; Jinping Wu; Bing Li; Weimin Du; Qingli Huang; Mingbo Zheng; Huaiguo Xue; Huan Pang

    2016-01-01

    Polypyrrole nanowires are facile synthesized under a mild condition with FeCl3 as an oxidant. Polypyrrole nanowires with the width of 120 nm form many nanogaps or pores due to the intertwined nanos-tructures. More importantly, PPy nanowires were further applied for supercapacitor electrode materials. After electrochemical testing, it was observed that the PPy nanowire based electrode showed a large specific capacitance (420 F g ? 1, 1.5 A g ? 1) and good rate capability (272 F g ? 1, 18.0 A g ? 1), which is larger than that of most of published results. The as-prepared electrode can work well even after 8000 cycles at 1.5 A g ? 1.

  3. Preparation and electrochemical characterization of C/PANI composite electrode materials

    Institute of Scientific and Technical Information of China (English)

    LAI Yan-qing; LI Jing; LI Jie; LU Hai; ZHANG Zhi-an; LIU Ye-xiang

    2006-01-01

    Taking the nano-sized carbon black and aniline monomer as precursor and (NH4)2 S2 O6 as oxidant, the well coated C/polyaniline(C/PANI) composite materials were prepared by in situ polymerization of the aniline on the surface of well-dispersed nano-sized carbon black for supercapacitor. The micro-structure of the C/PANI composite electrode materials were analyzed by SEM. The electrochemical properties of C/ PANI and PANI composite electrode were characterized by means of the galvanostatic charge-discharge experiment, cyclic voltammetric measurement and impedance spectroscopy analysis. The results show that by adding the nano-sized carbon black in the process of chemical polymerization of the aniline, the polyaniline can be in situ polymerized and well-coated onto the carbon black particles, which may effectively improve the aggregation of particles and the electrolyte penetration.with PANI electrode, C/PANI electrode shows more desired capacitance characteristics, smaller internal resistance and better cycle performance.

  4. Recent development of carbon electrode materials and their bioanalytical and environmental applications.

    Science.gov (United States)

    Zhang, Wei; Zhu, Shuyun; Luque, Rafael; Han, Shuang; Hu, Lianzhe; Xu, Guobao

    2016-02-07

    Carbon materials have been extensively investigated due to their diversity, favorable properties, and active applications including electroanalytical chemistry. This critical review discusses new synthetic methods, novel carbon materials, new properties and electroanalytical applications of carbon materials particularly related to the preparation as well as bioanalytical and environmental applications of highly oriented pyrolytic graphite, graphene, carbon nanotubes, various carbon films (e.g. pyrolyzed carbon films, boron-doped diamond films and diamond-like carbon films) and screen printing carbon electrodes. Future perspectives in the field have also been discussed (366 references).

  5. Morphological and Electrochemical Properties of the Lactose-derived Carbon Electrode Materials

    Directory of Open Access Journals (Sweden)

    I.F. Myronyuk

    2016-11-01

    Full Text Available The article explores the morphological and electrochemical properties of carbon electrode materials derived from D-lactose by mixing of carbon precursor with activating reagent selected from a number КОН, K2CO3, ZnCl2, SnCl2∙2H2O, and calcining the composite mixture at 800 °С. After dissolution and removal of K2O, ZnO or SnO from volume of prototypes specific surface of carbon materials increases in 1,7-4,2 times, and electrical conductivity - in 1,4-2,8 times. The activating reagents for effective influence on the properties of carbon structures can be placed in the following order: ZnCl2  КОН  K2CO3  SnCl2∙2H2O. It is set that the highest specific capacity as an electrode material for supercapacitor has a sample with the highest electrical conductivity (78 Оhm – 1∙m – 1 obtained using KOH activating reagent. The electrode material capacity was 176-157 F∙g – 1 at discharge currents of 10-100 mA. It was found that the difference in the values of capacitance of prototypes caused by different chemical state of their surface.

  6. Morphological and Electrochemical Properties of the Lactose-derived Carbon Electrode Materials

    Directory of Open Access Journals (Sweden)

    I.F. Myronyuk

    2016-10-01

    Full Text Available The article explores the morphological and electrochemical properties of carbon electrode materials derived from D-lactose by mixing of carbon precursor with activating reagent selected from a number КОН, K2CO3, ZnCl2, SnCl2∙2H2O, and calcining the composite mixture at 800 °С. After dissolution and removal of K2O, ZnO or SnO from volume of prototypes specific surface of carbon materials increases in 1,7-4,2 times, and electrical conductivity - in 1,4-2,8 times. The activating reagents for effective influence on the properties of carbon structures can be placed in the following order: ZnCl2 > КОН > K2CO3 > SnCl2∙2H2O. It is set that the highest specific capacity as an electrode material for supercapacitor has a sample with the highest electrical conductivity (78 Оhm – 1∙m – 1 obtained using KOH activating reagent. The electrode material capacity was 176-157 F∙g – 1 at discharge currents of 10-100 mA. It was found that the difference in the values of capacitance of prototypes caused by different chemical state of their surface.

  7. Synthesis of an organic conductive porous material using starch aerogels as template for chronic invasive electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Starbird, Ricardo, E-mail: ricardo.starbird@tu-harburg.de [Institute of Optical and Electronic Materials, Hamburg University of Technology, Hamburg, 21073 (Germany); García-González, Carlos A.; Smirnova, Irina [Institute of Thermal Separation Processes, Hamburg University of Technology, Hamburg, 21073 (Germany); Krautschneider, Wolfgang H. [Institute of Nanoelectronics, Hamburg University of Technology, Hamburg (Germany); Bauhofer, Wolfgang [Institute of Optical and Electronic Materials, Hamburg University of Technology, Hamburg, 21073 (Germany)

    2014-04-01

    We report the development of an organic conducting mesoporous material, as coat for invasive electrodes, by a novel methodology based on the use of starch aerogel as template. The poly(3,4-ethylenedioxythiophene) (PEDOT) aerogel was synthesized by polymerization of 3,4-ethylenedioxythiophene within a saturated starch aerogel with iron (III) p-toluenesulfonate (oxidizing agent) and subsequent removal of the polysaccharide template, followed by supercritical CO{sub 2} drying. The chemical structure and oxidation state of the resulting material were studied by Raman spectroscopy. The morphology and surface properties of the obtained nanoporous material were investigated by scanning electron microscopy (SEM), micro computed tomography (μCT) and nitrogen adsorption–desorption techniques. The composition and thermal behaviour were evaluated by energy dispersive spectroscopy (EDS) and thermogravimetric analysis (TGA) respectively. A preliminary biocompatibility test verified the non-cytotoxic effects of the PEDOT aerogel. The large surface area and wide pore size distribution of the PEDOT conductive aerogel, along with its electrical properties, enable it to be used as extracellular matrix scaffold for biomedical applications. - Highlights: • Conductive porous material (PEDOT) was obtained using starch aerogel as template • The large mesoporous surface allows its use as extracellular matrix scaffold • The conductive organic aerogel is a suitable coat for chronic invasive electrodes • Gold electrodes coated with PEDOT aerogel showed a significant reduction of the impedance.

  8. Nickel-Tin Electrode Materials for Nonaqueous Li-Ion Cells

    Science.gov (United States)

    Ehrlich, Grant M.; Durand, Christopher

    2005-01-01

    Experimental materials made from mixtures of nickel and tin powders have shown promise for use as the negative electrodes of rechargeable lithium-ion electrochemical power cells. During charging (or discharging) of a lithium-ion cell, lithium ions are absorbed into (or desorbed from, respectively) the negative electrode, typically through an intercalation or alloying process. The negative electrodes (for this purpose, designated as anodes) in state-of-the-art Li-ion cells are made of graphite, in which intercalation occurs. Alternatively, the anodes can be made from metals, in which alloying can occur. For reasons having to do with the electrochemical potential of intercalated lithium, metallic anode materials (especially materials containing tin) are regarded as safer than graphite ones; in addition, such metallic anode materials have been investigated in the hope of obtaining reversible charge/discharge capacities greater than those of graphite anodes. However, until now, each of the tin-containing metallic anode formulations tested has been found to be inadequate in some respect.

  9. High-Energy-Density LCA-Coupled Structural Energetic Materials for Counter WMD Applications

    Science.gov (United States)

    2014-04-01

    morphology , etc.) of reactants. In the case of the equivolumetric Ta+Fe2O3 powder mixtures, pre-densification results in generating Fe2O3 as the more...published in the following papers. • N.N. Thadhani and J.K. Cochran, "Energetic Materials", DTRA Basic and Applied Research Program Newsletter , V2, N3, p

  10. Cooperation of micro- and meso-porous carbon electrode materials in electric double-layer capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Cheng [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, Jilin Province (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Qi, Li; Wang, Hongyu [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, Jilin Province (China); Yoshio, Masaki [Advanced Research Center, Saga University, 1341 Yoga-machi, Saga 840-0047 (Japan)

    2010-07-01

    The capacitive characteristics of micro- and meso-porous carbon materials have been compared in cyclic voltammetric studies and galvanostatic charge-discharge tests. Meso-porous carbon can keep certain high capacitance values at high scan rates, whereas micro-porous carbon possesses very high capacitance values at low scan rates but fades quickly as the scan rate rises up. For better performance of electric double-layer capacitors (EDLCs), the cooperative application of both kinds of carbon materials has been proposed in the following two ways: mixing both kinds of carbons in the same electrode or using the asymmetric configuration of carbon electrodes in the same EDLC. The cooperative effect on the electrochemical performance has also been addressed. (author)

  11. Self-standing rationally functionalized graphene as high-performance electrode materials for supercapacitors

    Institute of Scientific and Technical Information of China (English)

    Delong Ma; Zhong Wu; Zhanyi Cao

    2014-01-01

    Supercapacitors (SCs) have attracted much attention as one of the alternative energy devices due to their high power performance, long cycle life, and low maintenance cost. Graphene is considered as an innovative and promising material due to its large theoretical specific surface area, high electrical conductivity, good mechanical properties and chemical stability. Herein, we report an effective strategy for elaborately constructing rationally functionalized self-standing graphene (SG) obtained from giant graphene oxide (GGO) paper followed by an ultrarapid thermal-processing. This treatment results in both the exfoliation of graphene sheets and the reduction of GGO by elimination of oxygen-containing groups. The as-prepared SG electrode materials without additive and conducting agent provide an excellent combination of the electrical double layer capacitor (EDLC) and pseudocapacitor (PC) functions and exhibit superior electrochemical performance, including high specific capacitance, good rate capability and excellent cycling stability when investigated in three-electrode electrochemical cells.

  12. One-Pot Solvothermal in Situ Growth of 1D Single-Crystalline NiSe on Ni Foil as Efficient and Stable Transparent Conductive Oxide Free Counter Electrodes for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Bao, Chao; Li, Faxin; Wang, Jiali; Sun, Panpan; Huang, Niu; Sun, Yihua; Fang, Liang; Wang, Lei; Sun, Xiaohua

    2016-12-07

    One-dimensional single-crystal nanostructural nickel selenides were successfully in situ grown on metal nickel foils by two simple one-step solvothermal methods, which formed NiSe/Ni counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The nickel foil acted as the nickel source in the reaction process, a supporting substrate, and an electron transport "speedway". Electrochemical testing indicated that the top 1D single-crystal NiSe exhibited prominent electrocatalytic activity for I3(-) reduction. Due to the metallic conductivity of Ni substrate and the outstanding electrocatalytic activity of single-crystal NiSe, the DSSC based on a NiSe/Ni CE exhibited higher fill factor (FF) and larger short-circuit current density (Jsc) than the DSSC based on Pt/FTO CE. The corresponding power conversion efficiency (6.75%) outperformed that of the latter (6.18%). Moreover, the NiSe/Ni CEs also showed excellent electrochemical stability in the I(-)/I3(-) redox electrolyte. These findings indicated that single-crystal NiSe in situ grown on Ni substrate was a potential candidate to replace Pt/TCO as a cheap and highly efficient counter electrode of DSSC.

  13. Molecular Engineering with Organic Carbonyl Electrode Materials for Advanced Stationary and Redox Flow Rechargeable Batteries.

    Science.gov (United States)

    Zhao, Qing; Zhu, Zhiqiang; Chen, Jun

    2017-04-03

    Organic carbonyl electrode materials that have the advantages of high capacity, low cost and being environmentally friendly, are regarded as powerful candidates for next-generation stationary and redox flow rechargeable batteries (RFBs). However, low carbonyl utilization, poor electronic conductivity and undesired dissolution in electrolyte are urgent issues to be solved. Here, we summarize a molecular engineering approach for tuning the capacity, working potential, concentration of active species, kinetics, and stability of stationary and redox flow batteries, which well resolves the problems of organic carbonyl electrode materials. As an example, in stationary batteries, 9,10-anthraquinone (AQ) with two carbonyls delivers a capacity of 257 mAh g(-1) (2.27 V vs Li(+) /Li), while increasing the number of carbonyls to four with the formation of 5,7,12,14-pentacenetetrone results in a higher capacity of 317 mAh g(-1) (2.60 V vs Li(+) /Li). In RFBs, AQ, which is less soluble in aqueous electrolyte, reaches 1 M by grafting -SO3 H with the formation of 9,10-anthraquinone-2,7-disulphonic acid, resulting in a power density exceeding 0.6 W cm(-2) with long cycling life. Therefore, through regulating substituent groups, conjugated structures, Coulomb interactions, and the molecular weight, the electrochemical performance of carbonyl electrode materials can be rationally optimized. This review offers fundamental principles and insight into designing advanced carbonyl materials for the electrodes of next-generation rechargeable batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Factors determining the photovoltaic performance of a CdSe quantum dot sensitized solar cell: the role of the linker molecule and of the counter electrode

    Science.gov (United States)

    Mora-Seró, Iván; Giménez, Sixto; Moehl, Thomas; Fabregat-Santiago, Francisco; Lana-Villareal, Teresa; Gómez, Roberto; Bisquert, Juan

    2008-10-01

    Colloidal CdSe quantum dots (QDs) of different sizes, prepared by a solvothermal route, have been employed as sensitizers of nanostructured TiO2 electrode based solar cells. Three different bifunctional linker molecules have been used to attach colloidal QDs to the TiO2 surface: mercaptopropionic acid (MPA), thioglycolic acid (TGA), and cysteine. The linker molecule plays a determinant role in the solar cell performance, as illustrated by the fact that the incident photon to charge carrier generation efficiency (IPCE) could be improved by a factor of 5-6 by using cysteine with respect to MPA. The photovoltaic properties of QD sensitized electrodes have been characterized for both three-electrode and closed two-electrode solar cell configurations. For three-electrode measurement a maximum power conversion efficiency near 1% can be deduced, but this efficiency is halved in the closed cell configuration mainly due to the decrease of the fill factor (FF).

  15. Challenges and Perspectives for NASICON-Type Electrode Materials for Advanced Sodium-Ion Batteries.

    Science.gov (United States)

    Chen, Shuangqiang; Wu, Chao; Shen, Laifa; Zhu, Changbao; Huang, Yuanye; Xi, Kai; Maier, Joachim; Yu, Yan

    2017-06-19

    Sodium-ion batteries (SIBs) have attracted increasing attention in the past decades, because of high overall abundance of precursors, their even geographical distribution, and low cost. Apart from inherent thermodynamic disadvantages, SIBs have to overcome multiple kinetic problems, such as fast capacity decay, low rate capacities and low Coulombic efficiencies. A special case is sodium super ion conductor (NASICON)-based electrode materials as they exhibit - besides pronounced structural stability - exceptionally high ion conductivity, rendering them most promising for sodium storage. Owing to the limiting, comparatively low electronic conductivity, nano-structuring is a prerequisite for achieving satisfactory rate-capability. In this review, we analyze advantages and disadvantages of NASICON-type electrode materials and highlight electrode structure design principles for obtaining the desired electrochemical performance. Moreover, we give an overview of recent approaches to enhance electrical conductivity and structural stability of cathode and anode materials based on NASICON structure. We believe that this review provides a pertinent insight into relevant design principles and inspires further research in this respect. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. 染料敏化太阳能电池Pt/NiP/ITO对电极的制备和性能%Preparation and Performance of Pt/NiP/ITO Counter Electrode for DSSC

    Institute of Scientific and Technical Information of China (English)

    马换梅; 田建华; 廖文明; 单忠强

    2012-01-01

    NiP alloy film was firstly prepared on the surface of the ITO conductive glass substrate by an electroless plating method,and then,the nanoparticles of platinum were electrodeposited on the NiP–plated layer to obtain Pt/NiP/ITO counter electrode used in DSSC.The parameters of Pt electro-deposition on NiP alloy layer were optimized.The influences of NiP alloy structure and Pt loading on the surface morphology and catalytic activity of Pt/NiP/ITO electrode were investigated.The surface morphology of Pt/NiP/ITO electrode was analyzed by atomic force microscopy.The electrochemical performance of Pt/NiP/ITO electrode was characterized by cyclic voltammetry and electrochemical impedance spectroscopy.The photovoltaic performance was evaluated from photocurrent-voltage curves in a single DSSC.The result shows that the NiP alloy deposited on ITO substrate enhances the conductivity and light reflection performance of the counter electrode,and also improves the distribution of Pt particles on the surface of electrode,resulting in that Jscand η of the DSSC are increased by 4% and 11%,respectively.%在ITO导电玻璃表面化学镀NiP合金薄膜,然后电化学沉积Pt纳米粒子,形成染料敏化太阳能电池Pt/NiP/ITO对电极。优化了化学镀NiP合金的工艺条件;研究了NiP的结构和铂载量对Pt/NiP/ITO电极形貌和催化活性的影响。采用原子力显微镜分析Pt/NiP/ITO电极的表面形貌;采用循环伏安法、电化学交流阻抗法表征其电化学性能;采用单体DSSC的光电流–电压曲线表征其光伏性能。测试结果表明,在ITO基体上化学镀NiP合金,提高了电极的导电性和光反射能力,改善了电极表面Pt粒子的分布,使电池的短路电流密度和光电转化效率分别提高了4%和11%。

  17. Surface modification of positive electrode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Julien, C.M., E-mail: Christian.Julien@upmc.fr [Sorbonne Universités, UPMC Univ. Paris 6, Physicochimie des Electrolytes et Nanosystèmes Interfaciaux (PHENIX), UMR 8234, 75005 Paris (France); Mauger, A. [Institut de Minéralogie de Physique des Matériaux et de Cosmochimie (IMPMC), UPMC Univ. Paris 6, 4 place Jussieu, 75005 Paris (France); Groult, H. [Sorbonne Universités, UPMC Univ. Paris 6, Physicochimie des Electrolytes et Nanosystèmes Interfaciaux (PHENIX), UMR 8234, 75005 Paris (France); Zaghib, K. [Energy Storage and Conversion, Research Institute of Hydro-Québec, Varennes, Québec J3X 1S1 (Canada)

    2014-12-01

    The advanced lithium-ion batteries are critically important for a wide range of applications, from portable electronics to electric vehicles. The research on their electrodes aims to increase the energy density and the power density, improve the calendar and the cycling life, without sacrificing the safety issues. A constant progress through the years has been obtained owing to the surface treatment of the particles, in particular the coating of the nanoparticles with a layer that protects the core region from side reactions with the electrolyte, prevents the loss of oxygen, and the dissolution of the metal ions in the electrolyte, or simply improve the conductivity of the powder. The purpose of the present work is to present the different surface modifications that have been tried for three families of positive electrodes: layered, spinel and olivine frameworks that are currently considered as promising materials. The role of the different coats used to improve either the surface conductivity, or the thermal stability, or the structural integrity is discussed. - Highlights: • Report the various surface modifications tried for the positive electrodes of Li-ion batteries. • The role of different coats used to improve the conductivity, or the thermal stability, or the structural integrity. • Improvement of electrochemical properties of electrodes after coating or surface treatment.

  18. Cellobiose dehydrogenase modified electrodes: advances by materials science and biochemical engineering.

    Science.gov (United States)

    Ludwig, Roland; Ortiz, Roberto; Schulz, Christopher; Harreither, Wolfgang; Sygmund, Christoph; Gorton, Lo

    2013-04-01

    The flavocytochrome cellobiose dehydrogenase (CDH) is a versatile biorecognition element capable of detecting carbohydrates as well as quinones and catecholamines. In addition, it can be used as an anode biocatalyst for enzymatic biofuel cells to power miniaturised sensor-transmitter systems. Various electrode materials and designs have been tested in the past decade to utilize and enhance the direct electron transfer (DET) from the enzyme to the electrode. Additionally, mediated electron transfer (MET) approaches via soluble redox mediators and redox polymers have been pursued. Biosensors for cellobiose, lactose and glucose determination are based on CDH from different fungal producers, which show differences with respect to substrate specificity, pH optima, DET efficiency and surface binding affinity. Biosensors for the detection of quinones and catecholamines can use carbohydrates for analyte regeneration and signal amplification. This review discusses different approaches to enhance the sensitivity and selectivity of CDH-based biosensors, which focus on (1) more efficient DET on chemically modified or nanostructured electrodes, (2) the synthesis of custom-made redox polymers for higher MET currents and (3) the engineering of enzymes and reaction pathways. Combination of these strategies will enable the design of sensitive and selective CDH-based biosensors with reduced electrode size for the detection of analytes in continuous on-site and point-of-care applications.

  19. Nickel/silicon core/shell nanosheet arrays as electrode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Huang, X.H., E-mail: drhuangxh@hotmail.com; Zhang, P.; Wu, J.B.; Lin, Y.; Guo, R.Q.

    2016-08-15

    Highlights: • Ni nanosheet arrays is the core and Si layer is the shell. • Ni nanosheet arrays act as a three-dimensional current collector to support Si. • Ni nanosheet arrays can improve the conductivity and stability of the electrode. • Ni/Si nanosheet arrays exhibit excellent cyclic and rate performance. - Abstract: Ni/Si core/shell nanosheet arrays are proposed to enhance the electrochemical lithium-storage properties of silicon. The arrays are characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The arrays are micro-sized in height, which are constructed by interconnected Ni nanosheet as the core and Si coating layer as the shell. The electrochemical properties as anode materials of lithium ion batteries are investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge tests. The arrays can achieve high reversible capacity, good cycle stability and high rate capability. It is believed that the enhanced electrochemical performance is attributed to the electrode structure, because the interconnected Ni nanosheet can act as a three-dimensional current collector, and it has the ability of improving the electrode conductivity, enlarging the electrochemical reaction interface, and suppressing the electrode pulverization.

  20. Comparison of carbon materials as electrodes for enzyme electrocatalysis: hydrogenase as a case study.

    Science.gov (United States)

    Quinson, Jonathan; Hidalgo, Ricardo; Ash, Philip A; Dillon, Frank; Grobert, Nicole; Vincent, Kylie A

    2014-01-01

    We present a study of electrocatalysis by an enzyme adsorbed on a range of carbon materials, with different size, surface area, morphology and graphitic structure, which are either commercially available or prepared via simple, established protocols. We choose as our model enzyme the hydrogenase I from E. coli (Hyd-1), which is an active catalyst for H2 oxidation, is relatively robust and has been demonstrated in H2 fuel cells and H2-driven chemical synthesis. The carbon materials were characterised according to their surface area, surface morphology and graphitic character, and we use the electrocatalytic H2 oxidation current for Hyd-1 adsorbed on these materials to evaluate their effectiveness as enzyme electrodes. Here, we show that a variety of carbon materials are suitable for adsorbing hydrogenases in an electroactive configuration. This unified study provides insight into selection and design of carbon materials for study of redox enzymes and different applications of enzyme electrocatalysis.

  1. Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: Comparison of electrode materials and electrode connection systems

    Energy Technology Data Exchange (ETDEWEB)

    Solak, Murat [Duezce University, Kaynasli Vocational School, Environmental Protection and Control Department, 81900 Duezce (Turkey); Kilic, Mehmet, E-mail: kavi@mmf.sdu.edu.tr [Sueleyman Demirel University, Engineering and Architecture Faculty, Environmental Engineering Department, 32260 Isparta (Turkey); Hueseyin, Yazici; Sencan, Aziz [Sueleyman Demirel University, Engineering and Architecture Faculty, Environmental Engineering Department, 32260 Isparta (Turkey)

    2009-12-15

    In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m{sup 2}, and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m{sup 2}, respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

  2. Nickel cobalt oxide nanowire-reduced graphite oxide composite material and its application for high performance supercapacitor electrode material.

    Science.gov (United States)

    Wang, Xu; Yan, Chaoyi; Sumboja, Afriyanti; Lee, Pooi See

    2014-09-01

    In this paper, we report a facile synthesis method of mesoporous nickel cobalt oxide (NiCo2O4) nanowire-reduced graphite oxide (rGO) composite material by urea induced hydrolysis reaction, followed by sintering at 300 degrees C. P123 was used to stabilize the GO during synthesis, which resulted in a uniform coating of NiCo2O4 nanowire on rGO sheet. The growth mechanism of the composite material is discussed in detail. The NiCo2O4-rGO composite material showed an outstanding electrochemical performance of 873 F g(-1) at 0.5 A g(-1) and 512 F g(-1) at 40 A g(-1). This method provides a promising approach towards low cost and large scale production of supercapacitor electrode material.

  3. The reaction current distribution in battery electrode materials revealed by XPS-based state-of-charge mapping.

    Science.gov (United States)

    Pearse, Alexander J; Gillette, Eleanor; Lee, Sang Bok; Rubloff, Gary W

    2016-07-28

    Morphologically complex electrochemical systems such as composite or nanostructured lithium ion battery electrodes exhibit spatially inhomogeneous internal current distributions, particularly when driven at high total currents, due to resistances in the electrodes and electrolyte, distributions of diffusion path lengths, and nonlinear current-voltage characteristics. Measuring and controlling these distributions is interesting from both an engineering standpoint, as nonhomogenous currents lead to lower utilization of electrode material, as well as from a fundamental standpoint, as comparisons between theory and experiment are relatively scarce. Here we describe a new approach using a deliberately simple model battery electrode to examine the current distribution in a electrode material limited by poor electronic conductivity. We utilize quantitative spatially resolved X-ray photoelectron spectroscopy to measure the spatial distribution of the state-of-charge of a V2O5 model electrode as a proxy measure for the current distribution on electrodes discharged at varying current densities. We show that the current at the electrode-electrolyte interface falls off with distance from the current collector, and that the current distribution is a strong function of total current. We compare the observed distributions with a simple analytical model which reproduces the dependence of the distribution on total current, but fails to predict the correct length scale. A more complete numerical simulation suggests that dynamic changes in the electronic conductivity of the V2O5 concurrent with lithium insertion may contribute to the differences between theory and experiment. Our observations should help inform design criteria for future electrode architectures.

  4. Pyrometallurgical Extraction of Valuable Elements in Ni-Metal Hydride Battery Electrode Materials

    Science.gov (United States)

    Jiang, Yin-ju; Deng, Yong-chun; Bu, Wen-gang

    2015-10-01

    Gas selective reduction-oxidation (redox) and melting separation were consecutively applied to electrode materials of AB5-type Ni-metal hydride batteries leading to the production of a Ni-Co alloy and slag enriched with rare earth oxides (REO). In the selective redox process, electrode materials were treated with H2/H2O at 1073 K and 1173 K (800 °C and 900 °C). Active elements such as REs, Al, and Mn were oxidized whereas relatively inert elements such as Ni and Co were transformed into their elemental states in the treated materials. SiO2 and Al2O3 powders were added into the treated materials as fluxes which were then melted at 1823 K (1550 °C) to yield a Ni-Co alloy and a REO-SiO2-Al2O3-MnO slag. The high-purity Ni-Co alloy produced can be used as a raw material for AB5-type hydrogen-storage alloy. The REO content in slag was very high, i.e., 48.51 pct, therefore it can be used to recycle rare earth oxides.

  5. Synergetic Hybrid Aerogels of Vanadia and Graphene as Electrode Materials of Supercapacitors

    Directory of Open Access Journals (Sweden)

    Xuewei Fu

    2016-08-01

    Full Text Available The performance of synergetic hybrid aerogel materials of vanadia and graphene as electrode materials in supercapacitors was evaluated. The hybrid materials were synthesized by two methods. In Method I, premade graphene oxide (GO hydrogel was first chemically reduced by L-ascorbic acid and then soaked in vanadium triisopropoxide solution to obtain V2O5 gel in the pores of the reduced graphene oxide (rGO hydrogel. The gel was supercritically dried to obtain the hybrid aerogel. In Method II, vanadium triisopropoxide was hydrolyzed from a solution in water with GO particles uniformly dispersed to obtain the hybrid gel. The hybrid aerogel was obtained by supercritical drying of the gel followed by thermal reduction of GO. The electrode materials were prepared by mixing 80 wt % hybrid aerogel with 10 wt % carbon black and 10 wt % polyvinylidene fluoride. The hybrid materials in Method II showed higher capacitance due to better interactions between vanadia and graphene oxide particles and more uniform vanadia particle distribution.

  6. Graphene/MnO{sub 2} hybrid nanosheets as high performance electrode materials for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, Anjon Kumar, E-mail: Anjon.K.Mondal@student.uts.edu.au [Centre for Clean Energy Technology, School of Chemistry and Forensic Science, University of Technology, Sydney, Broadway, Sydney, NSW 2007 (Australia); Wang, Bei; Su, Dawei; Wang, Ying; Chen, Shuangqiang [Centre for Clean Energy Technology, School of Chemistry and Forensic Science, University of Technology, Sydney, Broadway, Sydney, NSW 2007 (Australia); Zhang, Xiaogang [College of Materials Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing (China); Wang, Guoxiu, E-mail: Guoxiu.wang@uts.edu.au [Centre for Clean Energy Technology, School of Chemistry and Forensic Science, University of Technology, Sydney, Broadway, Sydney, NSW 2007 (Australia)

    2014-01-15

    Graphene/MnO{sub 2} hybrid nanosheets were prepared by incorporating graphene and MnO{sub 2} nanosheets in ethylene glycol. Scanning electron microscopy and transmission electron microscopy analyses confirmed nanosheet morphology of the hybrid materials. Graphene/MnO{sub 2} hybrid nanosheets with different ratios were investigated as electrode materials for supercapacitors by cyclic voltammetry (CV) and galvanostatic charge–discharge in 1 M Na{sub 2}SO{sub 4} electrolyte. We found that the graphene/MnO{sub 2} hybrid nanosheets with a weight ratio of 1:4 (graphene:MnO{sub 2}) delivered the highest specific capacitance of 320 F g{sup −1}. Graphene/MnO{sub 2} hybrid nanosheets also exhibited good capacitance retention on 2000 cycles. - Highlights: • Graphene/MnO{sub 2} hybrid nanosheets with different ratios were fabricated. • The specific capacitance is strongly dependent on graphene/MnO{sub 2} ratios. • The graphene/MnO{sub 2} hybrid electrode (1:4) exhibited high specific capacitance. • The electrode retained 84% of the initial specific capacitance after 2000 cycles.

  7. In-situ electrochemical route to aerogel electrode materials of graphene and hexagonal CeO₂.

    Science.gov (United States)

    Chen, Kunfeng; Xue, Dongfeng

    2015-05-15

    We reported a one-step in-situ electrochemical route to synthesize 3D aerogel electrode materials including graphene and hexagonal CeO2 composites. The graphene/CeO2 aerogel can be formed via freeze-drying graphene/CeO2 colloidal solution that was obtained by electrochemical exfoliation of graphite anode and in-situ deposition of CeO2 nanoparticles on graphene sheets in mixing electrolyte of (NH4)2SO4/Ce(NO3)3 and (NH4)2SO4/(NH4)2Ce(NO3)6. The as-obtained CeO2 nanoparticles were closely contacted with graphene, which can enhance the synergistic effect between graphene and CeO2. It is interesting that the as-obtained CeO2 products possessed hexagonal crystal structure that was rarely reported. The Faradaic reactivity of the graphene/CeO2 composites as supercapacitor was enhanced with the increase of the concentration of Ce salts in initial electrolyte. The introduction of CeO2 to graphene electrode can lead to the presence of additional pseudocapacitance besides the electric double-layer capacitance. This simple one-step in-situ electrochemical route can be extended to synthesize various graphene/metal oxide aerogel electrode materials for electric energy storage.

  8. Spurious chemical diffusion coefficients of Li{sup +} in electrode materials evaluated with GITT

    Energy Technology Data Exchange (ETDEWEB)

    Diss, E. [Paul Scherrer Inst., Villagen (Switzerland)

    2005-05-05

    The galvanostatic intermittent titration technique (GITT) has been used as a standard method for evaluating chemical diffusion coefficients in electrode materials in the last three decades. It will now be demonstrated that these chemical diffusion coefficients evaluated with GITT are spurious as any reaction kinetics is neglected in the GITT theory. The neglect of the reaction kinetics leads to a spurious potential dependence of the GITT diffusion coefficients with minima at those potentials where the slow scan rate cyclic voltammogram or differential capacity plot exhibits peaks even in case where the true chemical diffusion coefficient is constant. This will be demonstrated by the evaluation of GITT diffusion coefficients from numerically generated GITT experiments calculated with a constant chemical diffusion coefficient on the example of a spinel-type LiMn{sub 2}O{sub 4} electrode. (Author)

  9. CO2 Activated Carbon Aerogel with Enhanced Electrochemical Performance as a Supercapacitor Electrode Material.

    Science.gov (United States)

    Lee, Eo Jin; Lee, Yoon Jae; Kim, Jeong Kwon; Hong, Ung Gi; Yi, Jongheop; Yoon, Jung Rag; Song, In Kyu

    2015-11-01

    Carbon aerogel (CA) was prepared by a sol-gel polymerization of resorcinol and formaldehyde in ambient conditions. A series of activated carbon aerogels (ACA-X, X = 1, 2, 3, 4, 5, and 6 h) were then prepared by CO2 activation of CA with a variation of activation time (X) for use as an electrode material for supercapacitor. Specific capacitances of CA and ACA-X electrodes were measured by cyclic voltammetry and galvanostatic charge/discharge methods in 6 M KOH electrolyte. Among the samples, ACA-5 h showed the highest BET surface area (2574 m2/g) and the highest specific capacitance (100 F/g). It was found that CO2 activation was a very efficient method for enhancing physicochemical property and supercapacitive electrochemical performance of activated carbon aerogel.

  10. Materials Science of Electrodes and Interfaces for High-Performance Organic Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Marks, Tobin [Northwestern Univ., Evanston, IL (United States)

    2016-11-18

    The science of organic photovoltaic (OPV) cells has made dramatic advances over the past three years with power conversion efficiencies (PCEs) now reaching ~12%. The upper PCE limit of light-to-electrical power conversion for single-junction OPVs as predicted by theory is ~23%. With further basic research, the vision of such devices, composed of non-toxic, earth-abundant, readily easily processed materials replacing/supplementing current-generation inorganic solar cells may become a reality. Organic cells offer potentially low-cost, roll-to-roll manufacturable, and durable solar power for diverse in-door and out-door applications. Importantly, further gains in efficiency and durability, to that competitive with inorganic PVs, will require fundamental, understanding-based advances in transparent electrode and interfacial materials science and engineering. This team-science research effort brought together an experienced and highly collaborative interdisciplinary group with expertise in hard and soft matter materials chemistry, materials electronic structure theory, solar cell fabrication and characterization, microstructure characterization, and low temperature materials processing. We addressed in unconventional ways critical electrode-interfacial issues underlying OPV performance -- controlling band offsets between transparent electrodes and organic active-materials, addressing current loss/leakage phenomena at interfaces, and new techniques in cost-effective low temperature and large area cell fabrication. The research foci were: 1) Theory-guided design and synthesis of advanced crystalline and amorphous transparent conducting oxide (TCO) layers which test our basic understanding of TCO structure-transport property relationships, and have high conductivity, transparency, and tunable work functions but without (or minimizing) the dependence on indium. 2) Development of theory-based understanding of optimum configurations for the interfaces between oxide electrodes

  11. High valence transition metal doped strontium ferrites for electrode materials in symmetrical SOFCs

    Science.gov (United States)

    Fernández-Ropero, A. J.; Porras-Vázquez, J. M.; Cabeza, A.; Slater, P. R.; Marrero-López, D.; Losilla, E. R.

    2014-03-01

    In this paper we report the successful incorporation of high valence transition metals, i.e. Cr, Mo, W, V, Nb, Ti, Zr into SrFeO3-δ perovskite materials, for potential applications as symmetric electrode materials for Solid Oxide Fuel Cells. It is observed that the doping leads to a change from an orthorhombic structure (with partial ordering of oxygen vacancies) to a cubic one (with the oxygen vacancies disordered). These electrodes are chemically compatibles with Ce0.9Gd0.1O1.95 (CGO) and La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM) electrolytes at least up to 1100 °C. Thermal annealing experiments in 5% H2-Ar at 800 °C also show the stability of the doped samples in reducing conditions, suggesting that they may be suitable for both cathode and anode applications. In contrast, reduction of undoped SrFeO3-δ leads to the observation of extra peaks indicating the formation of the brownmillerite structure with the associated oxygen vacancy ordering. The performance of these electrodes was examined on dense electrolyte pellets of CGO and LSGM in air and 5% H2-Ar. In both atmospheres an improvement in the area specific resistances (ASR) values is observed for the doped samples with respect to the parent compound. Thus, the results show that high valence transition metals can be incorporated into SrFeO3-δ-based materials and can have a beneficial effect on the electrochemical performance, making them potentially suitable for use as cathode and anode materials in symmetrical SOFC.

  12. Identification and Mitigation of Generated Solid By-Products during Advanced Electrode Materials Processing.

    Science.gov (United States)

    Tsai, Candace S J; Dysart, Arthur D; Beltz, Jay H; Pol, Vilas G

    2016-03-01

    A scalable, solid-state elevated-temperature process was developed to produce high-capacity carbonaceous electrode materials for energy storage devices via decomposition of a starch-based precursor in an inert atmosphere. In a separate study, it is shown that the fabricated carbonaceous architectures are useful as an excellent electrode material for lithium-ion, sodium-ion, and lithium-sulfur batteries. This article focuses on the study and analysis of the formed nanometer-sized by-products during the lab-scale synthesis of the carbon material. The material production process was studied in operando (that is, during the entire duration of heat treatment). The unknown downstream particles in the process exhaust were collected and characterized via aerosol and liquid suspensions, and they were quantified using direct-reading instruments for number and mass concentrations. The airborne emissions were collected using the Tsai diffusion sampler (TDS) for characterization and further analysis. Released by-product aerosols collected in a deionized (DI) water trap were analyzed, and the aerosols emitted from the post-water-suspension were collected and characterized. After long-term sampling, individual particles in the nanometer size range were observed in the exhaust aerosol with layer-structured aggregates formed on the sampling substrate. Upon the characterization of the released aerosol by-products, methods were identified to mitigate possible human and environmental exposures upon industrial implementation.

  13. Spinel LiMn2O4 nanohybrid as high capacitance positive electrode material for supercapacitors

    Science.gov (United States)

    Wang, F. X.; Xiao, S. Y.; Zhu, Y. S.; Chang, Z.; Hu, C. L.; Wu, Y. P.; Holze, R.

    2014-01-01

    A LiMn2O4 nanohybrid consisting of nanotubes, nanorods and nanoparticles has been synthesized using α-MnO2 nanotubes from hydrothermal reaction as a precursor. It is characterized with X-ray diffraction, field emission scanning electron and transmission electron microscopy. A formation mechanism is proposed. As a positive electrode material for supercapacitors, it exhibits a high specific discharge capacitance of 415 F g-1 at 0.5 A g-1 in 0.5 mol l-1 Li2SO4 aqueous solution. Even at 10 A g-1, it still has a specific discharge capacitance of 208 F g-1. The energy density of the asymmetric supercapacitor using activated carbon as the negative electrode and LiMn2O4-nanohybrid as the positive electrode in the aqueous solution in the voltage range of 0-1.8 V presents 29.8 Wh kg-1 at power density of 90 W kg-1. In addition, the cycling behavior of the asymmetric supercapacitor is good.

  14. High-Performance Supercapacitor Electrode Materials from Cellulose-Derived Carbon Nanofibers.

    Science.gov (United States)

    Cai, Jie; Niu, Haitao; Li, Zhenyu; Du, Yong; Cizek, Pavel; Xie, Zongli; Xiong, Hanguo; Lin, Tong

    2015-07-15

    Nitrogen-functionalized carbon nanofibers (N-CNFs) were prepared by carbonizing polypyrrole (PPy)-coated cellulose NFs, which were obtained by electrospinning, deacetylation of electrospun cellulose acetate NFs, and PPy polymerization. Supercapacitor electrodes prepared from N-CNFs and a mixture of N-CNFs and Ni(OH)2 showed specific capacitances of ∼236 and ∼1045 F g(-1), respectively. An asymmetric supercapacitor was further fabricated using N-CNFs/Ni(OH)2 and N-CNFs as positive and negative electrodes. The supercapacitor device had a working voltage of 1.6 V in aqueous KOH solution (6.0 M) with an energy density as high as ∼51 (W h) kg(-1) and a maximum power density of ∼117 kW kg(-1). The device had excellent cycle lifetime, which retained ∼84% specific capacitance after 5000 cycles of cyclic voltammetry scans. N-CNFs derived from electrospun cellulose may be useful as an electrode material for development of high-performance supercapacitors and other energy storage devices.

  15. Composite Material Suitable for Use as Electrode Material in a SOC

    DEFF Research Database (Denmark)

    2010-01-01

    in a solid oxide cell, said composite material being based on (Gd1-xSrx)1-sFe1-yCoyO3-[delta] or (Ln1-xSrx)1-sFe1-yCioyO3-[delta](s equal to 0.05 or larger) wherein Ln is a lanthanide element, Sc or Y, said composite material comprising at least two phases which are non-miscible, said composite material...

  16. Conductive Polymer-Coated VS4 Submicrospheres As Advanced Electrode Materials in Lithium-Ion Batteries.

    Science.gov (United States)

    Zhou, Yanli; Li, Yanlu; Yang, Jing; Tian, Jian; Xu, Huayun; Yang, Jian; Fan, Weiliu

    2016-07-27

    VS4 as an electrode material in lithium-ion batteries holds intriguing features like high content of sulfur and one-dimensional structure, inspiring the exploration in this field. Herein, VS4 submicrospheres have been synthesized via a simple solvothermal reaction. However, they quickly degrade upon cycling as an anode material in lithium-ion batteries. So, three conductive polymers, polythiophene (PEDOT), polypyrrole (PPY), and polyaniline (PANI), are coated on the surface to improve the electron conductivity, suppress the diffusion of polysulfides, and modify the interface between electrode/electrolyte. PANI is the best in the polymers. It improves the Coulombic efficiency to 86% for the first cycle and keeps the specific capacity at 755 mAh g(-1) after 50 cycles, higher than the cases of naked VS4 (100 mAh g(-1)), VS4@PEDOT (318 mAh g(-1)), and VS4@PPY (448 mAh g(-1)). The good performances could be attributed to the improved charge-transfer kinetics and the strong interaction between PANI and VS4 supported by theoretical simulation. The discharge voltage ∼2.0 V makes them promising cathode materials.

  17. Carbon nanotube prepared from carbon monoxide by CVD method and its application as electrode materials

    Institute of Scientific and Technical Information of China (English)

    AN Yuliang; YUAN Xia; CHENG Shinan; GEN Xin

    2006-01-01

    Carbon nanotubes with larger inner diameter were synthesized by the chemical vapor deposition of carbon monoxide (CO) on iron catalyst using H2S as promoting agent.It is found that the structure and morphology of carbon nanotubes can be tailored, to some degree, by varying the experimental conditions such as precursor components and process parameters.The results show that the presence of H2S may play key role for growing Y-branched carbon nanotubes.The products were characterized by SEM, TEM, and Raman spectroscopy, respectively.Furthermore, the obtained carbon nanotubes were explored as electrode materials for supercapacitor.

  18. High rate, long cycle life battery electrode materials with an open framework structure

    Energy Technology Data Exchange (ETDEWEB)

    Wessells, Colin; Huggins, Robert; Cui, Yi; Pasta, Mauro

    2015-02-10

    A battery includes a cathode, an anode, and an aqueous electrolyte disposed between the cathode and the anode and including a cation A. At least one of the cathode and the anode includes an electrode material having an open framework crystal structure into which the cation A is reversibly inserted during operation of the battery. The battery has a reference specific capacity when cycled at a reference rate, and at least 75% of the reference specific capacity is retained when the battery is cycled at 10 times the reference rate.

  19. Effect of Structure on the Storage Characteristics of ManganeseOxide Electrode Materials

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Joon; Doeff, Marca M.

    2006-01-31

    Eleven types of manganese-containing electrode materialswere subjected to long-term storage at 55oC in 1M LiPF6 ethylenecarbonate/dimethyl carbonate (EC/DMC) solutions. The amount of manganesedissolution observed depended upon the sample surface area, the averageMn oxidation state, the structure, and substitution levels of themanganese oxide. In some cases, structural changes such as solvateformation were exacerbated by the high temperature storage, andcontributed to capacity fading upon cycling even in the absence ofsignificant Mn dissolution. The most stable materials appear to beTi-substituted tunnel structures and mixed metal layered oxides with Mnin the +4 oxidation state.

  20. A blister-test apparatus for studies on the adhesion of materials used for neural electrodes.

    Science.gov (United States)

    Ordonez, Juan; Boehler, Christian; Schuettler, Martin; Stieglitz, Thomas

    2011-01-01

    A blister test apparatus has been developed, which allows a quantitative adhesion analysis of thin-film metallizations on polymers manufactured in cleanroom conditions suitable for micromachining of neural electrode arrays. The device is capable of pressurizing metallic membranes at wafer level, monitoring the pressure and the height of the developing blister while detecting the moment of delamination, allowing the calculation of the adhesion energy between metal film and polymer. The machine is designed for quantitative long-term studies of materials used in neural microelectrode arrays.

  1. Synthesis and characterization of high performance electrode materials for lithium ion batteries

    Science.gov (United States)

    Hong, Jian

    Lithium-ion batteries have revolutionized portable electronics. Electrode reactions in these electrochemical systems are based on reversible intercalation of Li+ ions into the host electrode material with a concomitant addition/removal of electrons into the host. If such batteries are to find a wider market such as the automotive industry, less expensive and higher capacity electrode materials will be required. The olivine phase lithium iron phosphate has attracted the most attention because of its low cost and safety (high thermal and chemical stability). However, it is an intriguing fundamental problem to understand the fast electrochemical response from the poorly electronic conducting two-phase LiFePO4/FePO 4 system. This thesis focuses on determining the rate-limit step of LiFePO4. First, a LiFePO4 material, with vanadium substituting on the P-site, was synthesized, and found that the crystal structure change may cause high lithium diffusivity. Since an accurate Li diffusion coefficient cannot be measured by traditional electrochemical method in a three-electrode cell due to the phase transformation during measurement, a new method to measure the intrinsic electronic and ionic conductivity of mixed conductive LiFePO 4 was developed. This was based on the conductivity measurements of mixed conductive solid electrolyte using electrochemical impedance spectroscopy (EIS) and blocking electrode. The effects of ionic/electronic conductivity and phase transformation on the rate performance of LiFePO4 were also first investigated by EIS and other electrochemical technologies. Based on the above fundamental kinetics studies, an optimized LiFePO4 was used as a target to deposit 1mum LiFePO4 thin film at Oak Ridge National Laboratory using radio frequency (RF) magnetron sputtering. Similar to the carbon coated LiFePO4 powder electrode, the carbon-contained RF LiFePO4 film with no preferential orientation showed excellent capacity and rate capability both at 25°C and -20

  2. Synthesis and characterization of a binary oxide ZrO2–TiO2 and its application in chlorophyll dye-sensitized solar cell with reduced graphene oxide as counter electrodes

    Indian Academy of Sciences (India)

    Asha R Pai; Bipin Nair

    2015-09-01

    Natural dyes have been used to sensitize TiO2 nanocrystalline solar cells, but they still require pigment purification and co-adsorption of other compounds. In this study, nanocrystalline ZrO2–TiO2 films sensitized with the bioorganic dye, chlorophyll extracted from green leaves of Chromolaena odorata were investigated. The nanocrystalline ZrO2–TiO2 films were synthesized by the precipitation synthesis. The samples were characterized using X-ray diffraction, UV–vis absorption spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. The photoelectrodes were prepared using ZrO2–TiO2 sensitized with the chlorophyll dye and the counter electrodes using reduced graphene oxide. The shift in the absorption wavelength of chlorophyll showed an increase of adsorption of dye. The conversion efficiency was also studied.

  3. Zinc phthalocyanine and silver/gold nanoparticles incorporated MCM-41 type materials as electrode modifiers.

    Science.gov (United States)

    Pal, Manas; Ganesan, Vellaichamy

    2009-11-17

    Mercaptopropyl functionalized ordered mesoporous silica spheres were prepared (MPS). Ag or Au nanoparticles (NPs) were anchored onto the MPS materials (Ag-MPS or Au-MPS). Further, zinc phthalocyanine (ZnPc) was adsorbed into the channels and surface (MPS-ZnPc, Ag-MPS-ZnPc, Au-MPS-ZnPc). Diffuse reflectance studies revealed the successful incorporation of Ag or Au NPs inside the silica spheres with and without ZnPc. TEM images showed the uniform distribution of Ag or Au NPs in the silica spheres of different size ranging from 4 to 22 nm or 6 to 31 nm, respectively. XRD pattern showed average crystallite particle size of 18 or 28 nm for Ag or Au NPs respectively which were reduced to 14 or 16 nm on introduction of ZnPc which oxidizes the metal NPs partially. Chemically modified electrodes were prepared by coating the colloidal solutions of the silica materials on the glassy carbon (GC) electrodes. Electrocatalytic reductions of O(2) and CO(2) at the modified electrodes were studied. The presence of Ag or Au NPs was found to increase the electrocatalytic efficiency of ZnPc toward O(2) reduction by 290% or 70% based on the current density measured at -0.35 V and toward CO(2) reduction by 150% or 120% based on the current density measured at -0.60 V respectively. Catalytic rate constants were increased 2-fold for O(2) reduction and 8-fold for CO(2) reduction due to Ag or Au NPs, respectively, which act as nanoelectrode ensembles. The synergic effect of ZnPc and metal NPs on the electrocatalytic reduction of O(2) is presented.

  4. Facile synthesis of birnessite-type manganese oxide nanoparticles as supercapacitor electrode materials.

    Science.gov (United States)

    Liu, Lihu; Luo, Yao; Tan, Wenfeng; Zhang, Yashan; Liu, Fan; Qiu, Guohong

    2016-11-15

    Manganese oxides are environmentally benign supercapacitor electrode materials and, in particular, birnessite-type structure shows very promising electrochemical performance. In this work, nanostructured birnessite was facilely prepared by adding dropwise NH2OH·HCl to KMnO4 solution under ambient temperature and pressure. In order to fully exploit the potential of birnessite-type manganese oxide electrode materials, the effects of specific surface area, pore size, content of K(+), and manganese average oxidation state (Mn AOS) on their electrochemical performance were studied. The results showed that with the increase of NH2OH·HCl, the Mn AOS decreased and the corresponding pore sizes and specific surface area of birnessite increased. The synthesized nanostructured birnessite showed the highest specific capacitance of 245Fg(-1) at a current density of 0.1Ag(-1) within a potential range of 0-0.9V, and excellent cycle stability with a capacitance retention rate of 92% after 3000 cycles at a current density of 1.0Ag(-1). The present work implies that specific capacitance is mainly affected by specific surface area and pore volume, and provides a new method for the facile preparation of birnessite-type manganese oxide with excellent capacitive performance.

  5. Effects of rare earth elements on properties of AB5-type electrode materials at different temperature

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Discharge property is an important factor to evaluate electrode materials. The discharge capacity of the hydrogen-storing alloys are not only influenced by its thermodynamic property but also closely related to its dynamic property. When the temperature changes, the degrees of influence of the above-mentioned two factors on the discharge performance vary accordingly. As a consequence, adjusting compositions of the alloys to make them have good discharge performance under a relatively wide range of temperature is of great significance. On the basis of great deal of experimental investigation, the optimum combination of rare earth elements in hydrogen-storing electrode materials using at-30-55℃ is determined and the relationships between the cell parameters and discharge performance of alloys at -30℃ are discussed. Additionally, the DFEC calculation method has been improved to predict the discharge capacities, which is in good agreement with the experimental ones. This is of theoretical significance in investigating new hydrogen-storing alloys of the AB5 type.

  6. Improved Manufacturing Performance of Screen Printed Carbon Electrodes through Material Formulation.

    Science.gov (United States)

    Jewell, Eifion; Philip, Bruce; Greenwood, Peter

    2016-06-27

    Printed carbon graphite materials are the primary common component in the majority of screen printed sensors. Screen printing allows a scalable manufacturing solution, accelerating the means by which novel sensing materials can make the transition from laboratory material to commercial product. A common bottleneck in any thick film printing process is the controlled drying of the carbon paste material. A study has been undertaken which examines the interaction between material solvent, printed film conductivity and process consistency. The study illustrates that it is possible to reduce the solvent boiling point to significantly increase process productivity while maintaining process consistency. The lower boiling point solvent also has a beneficial effect on the conductivity of the film, reducing the sheet resistance. It is proposed that this is a result of greater film stressing increasing charge percolation through greater inter particle contact. Simulations of material performance and drying illustrate that a multi layered printing provides a more time efficient manufacturing method. The findings have implications for the volume manufacturing of the carbon sensor electrodes but also have implications for other applications where conductive carbon is used, such as electrical circuits and photovoltaic devices.

  7. Improved Manufacturing Performance of Screen Printed Carbon Electrodes through Material Formulation

    Directory of Open Access Journals (Sweden)

    Eifion Jewell

    2016-06-01

    Full Text Available Printed carbon graphite materials are the primary common component in the majority of screen printed sensors. Screen printing allows a scalable manufacturing solution, accelerating the means by which novel sensing materials can make the transition from laboratory material to commercial product. A common bottleneck in any thick film printing process is the controlled drying of the carbon paste material. A study has been undertaken which examines the interaction between material solvent, printed film conductivity and process consistency. The study illustrates that it is possible to reduce the solvent boiling point to significantly increase process productivity while maintaining process consistency. The lower boiling point solvent also has a beneficial effect on the conductivity of the film, reducing the sheet resistance. It is proposed that this is a result of greater film stressing increasing charge percolation through greater inter particle contact. Simulations of material performance and drying illustrate that a multi layered printing provides a more time efficient manufacturing method. The findings have implications for the volume manufacturing of the carbon sensor electrodes but also have implications for other applications where conductive carbon is used, such as electrical circuits and photovoltaic devices.

  8. Electroless Co-Zn Surface-modified Nickel Hydroxide as an Active Material for Pasted Nickel Electrodes

    Institute of Scientific and Technical Information of China (English)

    SONG Quan-sheng(宋全生); TANG Zhi-yuan(唐致远); GUO He-tong(郭鹤桐); CHAN S L I

    2004-01-01

    Chemically precipitated β-type nickel hydroxide powder was surface-modified by electroless deposition of Co-Zn coatings,and physical properties of both the modified and unmodified nickel hydroxide were characterized by scanning electron microscopy (SEM), specific surface area (BET), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It has been found that Co and Zn components of the surface electroless coatings exist in the oxidized state. Electrochemical performances of pasted nickel electrodes using the modified nickel hydroxide as an active material were investigated, and compared with those of the electrodes prepared with the unmodified nickel hydroxide. Charge/discharge tests show that the modified nickel hydroxide electrodes exhibit better performances in the charge efficiency, specific discharge capacity and active material utilization. Their resistance to swelling with cycling is also superior to that of the unmodified nickel hydroxide electrodes. Cyclic voltammetric (CV) studies indicate that the modified electrodes have a higher electrochemical activity, and the porous pasted nickel electrodes have some distinguished CV characteristics in comparison with those of the thin film nickel electrodes.

  9. Experimental and theoretical investigations of functionalized boron nitride as electrode materials for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fan; Nemeth, Karoly; Bareño, Javier; Dogan, Fulya; Bloom, Ira D.; Shaw, Leon L.

    2016-01-01

    The feasibility of synthesizing functionalized h-BN (FBN) via the reaction between molten LiOH and solid h-BN is studied for the first time and its first ever application as an electrode material in Li-ion batteries is evaluated. Density functional theory (DFT) calculations are performed to provide mechanistic understanding of the possible electrochemical reactions derived from the FBN. Various materials characterizations reveal that the melt-solid reaction can lead to exfoliation and functionalization of h-BN simultaneously, while electrochemical analysis proves that the FBN can reversibly store charges through surface redox reactions with good cycle stability and coulombic efficiency. DFT calculations have provided physical insights into the observed electrochemical properties derived from the FBN.

  10. Electrode materials: a challenge for the exploitation of protonic solid oxide fuel cells

    Directory of Open Access Journals (Sweden)

    Emiliana Fabbri, Daniele Pergolesi and Enrico Traversa

    2010-01-01

    Full Text Available High temperature proton conductor (HTPC oxides are attracting extensive attention as electrolyte materials alternative to oxygen-ion conductors for use in solid oxide fuel cells (SOFCs operating at intermediate temperatures (400–700 °C. The need to lower the operating temperature is dictated by cost reduction for SOFC pervasive use. The major stake for the deployment of this technology is the availability of electrodes able to limit polarization losses at the reduced operation temperature. This review aims to comprehensively describe the state-of-the-art anode and cathode materials that have so far been tested with HTPC oxide electrolytes, offering guidelines and possible strategies to speed up the development of protonic SOFCs.

  11. Sputtered platinum-iridium layers as electrode material for functional electrostimulation

    Energy Technology Data Exchange (ETDEWEB)

    Ganske, G., E-mail: ganske@iwe1.rwth-aachen.d [Institute of Materials in Electrical Engineering I, RWTH Aachen University, Sommerfeldstr. 24, D-52074 Aachen (Germany); Slavcheva, E. [Institute of Materials in Electrical Engineering I, RWTH Aachen University, Sommerfeldstr. 24, D-52074 Aachen (Germany); Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Ooyen, A. van; Mokwa, W.; Schnakenberg, U. [Institute of Materials in Electrical Engineering I, RWTH Aachen University, Sommerfeldstr. 24, D-52074 Aachen (Germany)

    2011-03-31

    In this study co-sputtered layers of platinum-iridium (PtIr) are investigated as stimulation electrode material. The effects of different sputter parameters on the morphology and the electrochemical behavior are examined. It is shown that films sputtered at the lowest incident energy possess the highest charge storage capacity (CSC). At a Pt:Ir atomic-ratio of 55:45 the obtained CSC of 22 mC/cm{sup 2} is enhanced compared to the standard stimulation material platinum (16 mC/cm{sup 2}) but inferior to iridium which has a CSC of 35 mC/cm{sup 2}. Long term cyclic voltammetry measurements show that PtIr can be activated which increases the CSC to 29 mC/cm{sup 2}. Also a change in the film morphology is observed. Sputtered platinum-iridium films promise to combine high mechanical strength and increased charge storage capacity.

  12. Characterisation of porous carbon electrode materials used in proton exchange membrane fuel cells via gas adsorption

    Science.gov (United States)

    Watt-Smith, M. J.; Rigby, S. P.; Ralph, T. R.; Walsh, F. C.

    Porous carbon materials are typically used in both the substrate (typically carbon paper) and the electrocatalyst supports (often platinised carbon) within proton exchange membrane fuel cells. Gravimetric nitrogen adsorption has been studied at a carbon paper substrate, two different Pt-loaded carbon paper electrodes and three particulate carbon blacks. N 2 BET surface areas and surface fractal dimensions were determined using the fractal BET and Frenkel-Halsey-Hill models for all but one of the materials studied. The fractal dimensions of the carbon blacks obtained from gas adsorption were compared with those obtained independently by small angle X-ray scattering and showed good agreement. Density functional theory was used to characterise one of the carbon blacks, as the standard BET model was not applicable.

  13. Studies on two classes of positive electrode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, James Douglas [Univ. of California, Berkeley, CA (United States)

    2008-12-01

    The development of advanced lithium-ion batteries is key to the success of many technologies, and in particular, hybrid electric vehicles. In addition to finding materials with higher energy and power densities, improvements in other factors such as cost, toxicity, lifetime, and safety are also required. Lithium transition metal oxide and LiFePO4/C composite materials offer several distinct advantages in achieving many of these goals and are the focus of this report. Two series of layered lithium transition metal oxides, namely LiNi1/3Co1/3-yMyMn1/3O2 (M=Al, Co, Fe, Ti) and LiNi0.4Co0.2-yMyMn0.4O2 (M = Al, Co, Fe), have been synthesized. The effect of substitution on the crystal structure is related to shifts in transport properties and ultimately to the electrochemical performance. Partial aluminum substitution creates a high-rate positive electrode material capable of delivering twice the discharge capacity of unsubstituted materials. Iron substituted materials suffer from limited electrochemical performance and poor cycling stability due to the degradation of the layered structure. Titanium substitution creates a very high rate positive electrode material due to a decrease in the anti-site defect concentration. LiFePO4 is a very promising electrode material but suffers from poor electronic and ionic conductivity. To overcome this, two new techniques have been developed to synthesize high performance LiFePO4/C composite materials. The use of graphitization catalysts in conjunction with pyromellitic acid leads to a highly graphitic carbon coating on the surface of LiFePO4 particles. Under the proper conditions, the room temperature electronic conductivity can be improved by nearly five orders of magnitude over untreated materials. Using Raman spectroscopy, the improvement in conductivity and rate performance of

  14. “Brick-like” N-doped graphene/carbon nanotube structure forming three-dimensional films as high performance metal-free counter electrodes in dye-sensitized solar cells

    Science.gov (United States)

    Ma, Jie; Li, Cheng; Yu, Fei; Chen, Junhong

    2015-01-01

    The "brick-like" N-doped graphene-carbon nanotube (NGC) composites are designed by mechanically grinding the filtration films, which are fabricated to form a three-dimensional structure film as a counter electrode (CE). The N-doped graphene/carbon nanotube films with a three-dimensional "brick-like" structure can provide numerous vertical active edge sites. The excellent electrochemical catalytic activities of CE can be obtained by adjusting the different ratio of graphene to CNTs to control the size and N-doping content of breaking particles. NGC17 CE based dye-sensitized solar cells (DSSC) have reached a high efficiency (6.74%) close to platinum-based cells (6.89%). The excellent efficiency may be attributed to the following factors: a) the ΔEP of NGC17 (304 mV) is lower than that of the Pt electrode (389 mV); b) the charge transfer resistance (Rct) at the NGC17-CE/electrolyte interface was 1.78 Ω cm-2, which is lower than that of a Pt-CE/electrolyte interface (8.97 Ω cm-2).

  15. Niobium doped lanthanum calcium ferrite perovskite as a novel electrode material for symmetrical solid oxide fuel cells

    Science.gov (United States)

    Kong, Xiaowei; Zhou, Xiaoliang; Tian, Yu; Wu, Xiaoyan; Zhang, Jun; Zuo, Wei

    2016-09-01

    Development of cost-effective and efficient electrochemical catalysts for the fuel cells electrode is of prime importance to emerging renewable energy technologies. Here, we report for the first time the novel La0.9Ca0.1Fe0.9Nb0.1O3-δ (LCFNb) perovskite with good potentiality for the electrode material of the symmetrical solid oxide fuel cells (SSOFC). The Sc0.2Zr0.8O2-δ (SSZ) electrolyte supported symmetrical cells with impregnated LCFNb and LCFNb/SDC (Ce0.8Sm0.2O2-δ) electrodes achieve relatively high power outputs with maximum power densities (MPDs) reaching up to 392 and 528.6 mW cm-2 at 850 °C in dry H2, respectively, indicating the excellent electro-catalytic activity of LCFNb towards both hydrogen oxidation and oxygen reduction. Besides, the MPDs of the symmetrical cells with LCFNb/SDC composite electrodes in CO and syngas (CO: H2 = 1:1) are almost identical to those in H2, implying that LCFNb material has similar catalytic activities to carbon monoxide compared with hydrogen. High durability in both H2, CO and syngas during the short term stability tests for 50 h are also obtained, showing desirable structure stability, and carbon deposition resistance of LCFNb based electrodes. The present results indicate that the LCFNb perovskite with remarkable cell performance is a promising electrode material for symmetrical SOFCs.

  16. Influence of carbon electrode material on energy recovery from winery wastewater using a dual-chamber microbial fuel cell.

    Science.gov (United States)

    Penteado, Eduardo D; Fernandez-Marchante, Carmen M; Zaiat, Marcelo; Gonzalez, Ernesto R; Rodrigo, Manuel A

    2017-06-01

    The aim of this work was to evaluate three carbon materials as anodes in microbial fuel cells (MFCs), clarifying their influence on the generation of electricity and on the treatability of winery wastewater, a highly organic-loaded waste. The electrode materials tested were carbon felt, carbon cloth and carbon paper and they were used at the same time as anode and cathode in the tests. The MFC equipped with carbon felt reached the highest voltage and power (72 mV and 420 mW m(-2), respectively), while the lowest values were observed when carbon paper was used as electrode (0.2 mV and 8.37·10(-6) mW m(-2), respectively). Chemical oxygen demand (COD) removal from the wastewater was observed to depend on the electrode material, as well. When carbon felt was used, the MFC showed the highest average organic matter consumption rate (650 mg COD L(-1) d(-1)), whereas by using carbon paper the rate decreased to 270 mg COD L(-1) d(-1). Therefore, both electricity generation and organic matter removal are strongly related not to the chemical composition of the electrode (which was graphite carbon in the three electrodes), but to its surface features and, consequently, to the amount of biomass adhered to the electrode surface.

  17. Atomic-scale structure evolution in a quasi-equilibrated electrochemical process of electrode materials for rechargeable batteries.

    Science.gov (United States)

    Gu, Lin; Xiao, Dongdong; Hu, Yong-Sheng; Li, Hong; Ikuhara, Yuichi

    2015-04-01

    Lithium-ion batteries have proven to be extremely attractive candidates for applications in portable electronics, electric vehicles, and smart grid in terms of energy density, power density, and service life. Further performance optimization to satisfy ever-increasing demands on energy storage of such applications is highly desired. In most of cases, the kinetics and stability of electrode materials are strongly correlated to the transport and storage behaviors of lithium ions in the lattice of the host. Therefore, information about structural evolution of electrode materials at an atomic scale is always helpful to explain the electrochemical performances of batteries at a macroscale. The annular-bright-field (ABF) imaging in aberration-corrected scanning transmission electron microscopy (STEM) allows simultaneous imaging of light and heavy elements, providing an unprecedented opportunity to probe the nearly equilibrated local structure of electrode materials after electrochemical cycling at atomic resolution. Recent progress toward unraveling the atomic-scale structure of selected electrode materials with different charge and/or discharge state to extend the current understanding of electrochemical reaction mechanism with the ABF and high angle annular dark field STEM imaging is presented here. Future research on the relationship between atomic-level structure evolution and microscopic reaction mechanisms of electrode materials for rechargeable batteries is envisaged.

  18. Lactose electroisomerization into lactulose: effect of the electrode material, active membrane surface area-to-electrode surface area ratio, and interelectrode-membrane distance.

    Science.gov (United States)

    Aït-Aissa, Amara; Aïder, Mohammed

    2014-01-01

    The aim of the present work was to study and develop an innovative, clean, and environmentally friendly process for lactulose synthesis by electroactivation of lactose. In this work, the electrode material (type 304 stainless steel, titanium, and copper), dimensionless interelectrode-membrane distance at the cathodic compartment (0.36, 0.68, and 1), and the membrane:electrode surface area ratio (0.23, 0.06, and 0.015) were considered to be the factors that could affect the kinetic conversion of lactose into lactulose. The reactions were conducted under an initial lactose concentration of 0.15mol/L at 10°C, Froude number (mixing speed) of 2.05×10(-2), and electric current intensity of 300mA for 30min. The highest lactulose formation yield of 32.50% (0.05mol/L) was obtained by using a copper electrode, interelectrode-membrane distance of 0.36, and membrane:electrode surface area ratio of 0.23. The 2-parameter Langmuir, Freundlich, and Temkin isotherm models were used for the prediction of the lactose isomerization kinetics as well as the 3-parameter Langmuir-Freundlich isotherm model. It was shown that the lactose isomerization kinetics into lactulose followed the Temkin and Langmuir-Freundlich models with coefficients of determination of 0.99 and 0.90 and a relative error of 1.42 to 1.56% and 4.27 to 4.37%, respectively.

  19. Electrode Materials, Thermal Annealing Sequences, and Lateral/Vertical Phase Separation of Polymer Solar Cells from Multiscale Molecular Simulations

    KAUST Repository

    Lee, Cheng-Kuang

    2014-12-10

    © 2014 American Chemical Society. The nanomorphologies of the bulk heterojunction (BHJ) layer of polymer solar cells are extremely sensitive to the electrode materials and thermal annealing conditions. In this work, the correlations of electrode materials, thermal annealing sequences, and resultant BHJ nanomorphological details of P3HT:PCBM BHJ polymer solar cell are studied by a series of large-scale, coarse-grained (CG) molecular simulations of system comprised of PEDOT:PSS/P3HT:PCBM/Al layers. Simulations are performed for various configurations of electrode materials as well as processing temperature. The complex CG molecular data are characterized using a novel extension of our graph-based framework to quantify morphology and establish a link between morphology and processing conditions. Our analysis indicates that vertical phase segregation of P3HT:PCBM blend strongly depends on the electrode material and thermal annealing schedule. A thin P3HT-rich film is formed on the top, regardless of bottom electrode material, when the BHJ layer is exposed to the free surface during thermal annealing. In addition, preferential segregation of P3HT chains and PCBM molecules toward PEDOT:PSS and Al electrodes, respectively, is observed. Detailed morphology analysis indicated that, surprisingly, vertical phase segregation does not affect the connectivity of donor/acceptor domains with respective electrodes. However, the formation of P3HT/PCBM depletion zones next to the P3HT/PCBM-rich zones can be a potential bottleneck for electron/hole transport due to increase in transport pathway length. Analysis in terms of fraction of intra- and interchain charge transports revealed that processing schedule affects the average vertical orientation of polymer chains, which may be crucial for enhanced charge transport, nongeminate recombination, and charge collection. The present study establishes a more detailed link between processing and morphology by combining multiscale molecular

  20. Bimetallic Co-Mn perovskite fluorides as high-stable electrode materials for supercapacitors.

    Science.gov (United States)

    Shi, Wei; Ding, Rui; Li, Xudong; Xu, Qilei; Ying, Danfeng; Huang, Yongfa; Liu, Enhui

    2017-09-14

    Bimetallic Co-Mn perovskite fluorides (KCoxMn1-xF3, denoted as K-Co-Mn-F) with various Co/Mn ratios (1:0, 12:1, 6:1, 3:1, 1:1, 1:3, 0:1) were prepared via one-pot solvothermal strategy and further used as electrode materials for supercapacitors. The optimal K-Co-Mn-F (Co/Mn=6:1) candidate showed size range of 0.1-1 μm and uniform element distribution, exhibiting the light changes in XRD diffraction peaks and XPS binding energy in comparison for the bare K-Co-F and K-Mn-F due to the structural/electronic effects. Owing to the stronger synergistic effect of Co/Mn redox species, the K-Co-Mn-F (Co/Mn=6:1) electrode exhibited superior specific capacity and rate behavior (113-100 C g-1 at 1-16 A g-1) together with excellent cycling stability (118% for 5000 cycles at 8 A g-1), and the AC//K-Co-Mn-F (Co/Mn=6:1) asymmetric capacitor showed superior energy and power densities (8.0-2.4 Wh Kg-1 at 0.14-8.7 KW Kg-1) along with high cycling stability (90% for 10000 cycles at 5 A g-1). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Influence of KOH activation techniques on pore structure and electrochemical property of carbon electrode materials

    Institute of Scientific and Technical Information of China (English)

    LI Jing; LI Jie; LAI Yan-qing; SONG Hai-sheng; ZHANG Zhi-an; LIU Ye-xiang

    2006-01-01

    Taking the selection of coal-tar pitch as precursor and KOH as activated agent, the activated carbon electrode material was fabricated for supercapacitor. The surface area and the pore structure of activated carbon were analyzed by Nitro adsorption method. The electrochemical properties of the activated carbons were determined using two-electrode capacitors in 6 mol/L KOH aqueous electrolytes. The influences of activated temperature and mass ratio ofKOH to C on the pore structure and electrochemical property of porous activated carbon were investigated in detail. The reasons for the changes of pore structure and electrochemical performance of activated carbon prepared under different conditions were also discussed theoretically. The results indicate that the maximum specific capacitance of 240 F/g can be obtained in alkaline medium, and the surface area, the pore structure and the specific capacitance of activated carbon depend on the treatment methods; the capacitance variation of activated carbon cannot be interpreted only by the change of surface area and pore structure, the lattice order and the electrolyte wetting effect of the activated carbon should also be taken into account.

  2. Drying and moisture resorption behaviour of various electrode materials and separators for lithium-ion batteries

    Science.gov (United States)

    Stich, Michael; Pandey, Nisrit; Bund, Andreas

    2017-10-01

    The drying behaviour and water uptake of a variety of commonly used electrode materials (graphite, LiFePO4, LiMn2O4, LiCoO2, Li(NiCoMn)O2) and separators (polyolefin, glass fibre) for lithium-ion batteries (LIBs) are investigated. The drying experiments are carried out using a coulometric Karl Fischer titrator in combination with a vaporiser. This setup leads to a highly sensitive and precise method to quantify water amounts in the microgram range in solid materials. Thereby the mass specific drying behaviour at RT and 120 °C is determined as well as the water resorption of the investigated materials in conditioned air atmosphere (T: 25 °C, RH: 40%). By extracting characteristic water detection rate curves for the investigated materials, a method is developed to predict the water detection beyond the runtime of the experiment. The results help optimising drying procedures of LIB components and thus can save time and costs. It is also shown, that water contaminations in graphite/LiFePO4 coin cells with a LiPF6 based electrolyte lead to a faster capacity fade during cycling and a significant change of the cell impedance.

  3. Novel synthesis of Ni-ferrite (NiFe{sub 2}O{sub 4}) electrode material for supercapacitor applications

    Energy Technology Data Exchange (ETDEWEB)

    Venkatachalam, V.; Jayavel, R., E-mail: rjvel@annauniv.edu [Centre for Nanoscience and Technology, Anna University, Chennai-600025 (India)

    2015-06-24

    Novel nanocrystalline NiFe{sub 2}O{sub 4} has been synthesized through combustion route using citric acid as a fuel. Phase of the synthesized material was analyzed using powder X-ray diffraction. The XRD study revealed the formation of spinel phase cubic NiFe{sub 2}O{sub 4} with high crystallinity. The average crystallite size of NiFe{sub 2}O{sub 4} nanomaterial was calculated from scherrer equation. The electrochemical properties were realized by cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy. The electrode material shows a maximum specific capacitance of 454 F/g with pseudocapacitive behavior. High capacitance retention of electrode material over 1000 continuous charging-discharging cycles suggests its excellent electrochemical stability. The results revealed that the nickel ferrite electrode is a potential candidate for energy storage applications in supercapacitor.

  4. Synthesis and characterization of NiCo2O4 nanoplates as efficient electrode materials for electrochemical supercapacitors

    Science.gov (United States)

    Kim, Taehyun; Ramadoss, Ananthakumar; Saravanakumar, Balasubramaniam; Veerasubramani, Ganesh Kumar; Kim, Sang Jae

    2016-05-01

    In the present work, NiCo2O4 nanoplates were prepared by a facile, low temperature, hydrothermal method, followed by thermal annealing and used supercapacitor applications. The physico-chemical characterization of as-prepared materials were investigated by means of X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR) and field emission scanning electron microscopy (FE-SEM). The electrochemical measurements demonstrate that the NiCo2O4 nanoplates electrode (NC-5) exhibits a high specific capacitance of 332 F g-1 at a scan rate of 5 mV s-1 and also retained about 86% of the initial specific capacitance value even after 2000 cycles at a current density of 2.5 A g-1. These results suggest that the fabricated electrode material has huge potential as a novel electrode material for electrochemical capacitors.

  5. Recent Advancements in the Cobalt Oxides, Manganese Oxides, and Their Composite As an Electrode Material for Supercapacitor: A Review

    Directory of Open Access Journals (Sweden)

    Santosh J. Uke

    2017-08-01

    Full Text Available Recently, our modern society demands the portable electronic devices such as mobile phones, laptops, smart watches, etc. Such devices demand light weight, flexible, and low-cost energy storage systems. Among different energy storage systems, supercapacitor has been considered as one of the most potential energy storage systems. This has several significant merits such as high power density, light weight, eco-friendly, etc. The electrode material is the important part of the supercapacitor. Recent studies have shown that there are many new advancement in electrode materials for supercapacitors. In this review, we focused on the recent advancements in the cobalt oxides, manganese oxides, and their composites as an electrode material for supercapacitor.

  6. Novel synthesis of Ni-ferrite (NiFe2O4) electrode material for supercapacitor applications

    Science.gov (United States)

    Venkatachalam, V.; Jayavel, R.

    2015-06-01

    Novel nanocrystalline NiFe2O4 has been synthesized through combustion route using citric acid as a fuel. Phase of the synthesized material was analyzed using powder X-ray diffraction. The XRD study revealed the formation of spinel phase cubic NiFe2O4 with high crystallinity. The average crystallite size of NiFe2O4 nanomaterial was calculated from scherrer equation. The electrochemical properties were realized by cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy. The electrode material shows a maximum specific capacitance of 454 F/g with pseudocapacitive behavior. High capacitance retention of electrode material over 1000 continuous charging-discharging cycles suggests its excellent electrochemical stability. The results revealed that the nickel ferrite electrode is a potential candidate for energy storage applications in supercapacitor.

  7. Layered double hydroxides as electrode materials for Ni based batteries and as novel inorganic/organic hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Caravaggio, G.

    2002-07-01

    This study examined the electrochemical properties of layered double hydroxides (LDH) in half-cells to determine if they can be used in nickel-cadmium (Ni-Cd) and nickel-metal hydride (NiMH) batteries. The LDHs were prepared by coprecipitation and were characterized by X-ray diffraction analysis. The nickel-aluminium LDHs were found to be the most stable during potassium hydroxide electrolyte discharge because the aluminium acted in a two fold manner. The high charge to radius ratio increased the electrostatic interaction between the anions and the metal layers. The acidity of the hydroxyl groups was due to the high exchange of electrons. The powders had lower discharge capacity compared to commercial electrode materials because of their low density. The nickel-vanadium LDHs exchanged only up to 1.2 electrons and were stable only up to a maximum of 14 days in electrolytic solutions of the cells. Zinc-aluminium LDHs were also synthesized and intercalated with phenyl phosphonic acid or 1,4-phenylene bis phosphonic acid to create microporous materials. X-ray diffraction, infra-red spectroscopy and nuclear magnetic resonance was used to characterize the compounds and determine crystallographic spacing. Grafting of both phosphonates to the metal layers had occurred and both materials showed little or no microporosity.

  8. Conformal coating of thin polymer electrolyte layer on nanostructured electrode materials for three-dimensional battery applications.

    Science.gov (United States)

    Gowda, Sanketh R; Reddy, Arava Leela Mohana; Shaijumon, Manikoth M; Zhan, Xiaobo; Ci, Lijie; Ajayan, Pulickel M

    2011-01-12

    Various three-dimensional (3D) battery architectures have been proposed to address effective power delivery in micro/nanoscale devices and for increasing the stored energy per electrode footprint area. One step toward obtaining 3D configurations in batteries is the formation of core-shell nanowires that combines electrode and electrolyte materials. One of the major challenges however in creating such architectures has been the coating of conformal thin nanolayers of polymer electrolytes around nanostructured electrodes. Here we show conformal coatings of 25-30 nm poly(methyl methacralate) electrolyte layers around individual Ni-Sn nanowires used as anodes for Li ion battery. This configuration shows high discharge capacity and excellent capacity retention even at high rates over extended cycling, allowing for scalable increase in areal capacity with electrode thickness. Our results demonstrate conformal nanoscale anode-electrolyte architectures for an efficient Li ion battery system.

  9. Few-layer MoS2-anchored graphene aerogel paper for free-standing electrode materials.

    Science.gov (United States)

    Lee, Wee Siang Vincent; Peng, Erwin; Loh, Tamie Ai Jia; Huang, Xiaolei; Xue, Jun Min

    2016-04-21

    To reduce the reliance on polymeric binders, conductive additives, and metallic current collectors during the electrode preparation process, as well as to assess the true performance of lithium ion battery (LIB) anodes, a free-standing electrode has to be meticulously designed. Graphene aerogel is a popular scaffolding material that has been widely used with embedded nanoparticles for application in LIB anodes. However, the current graphene aerogel/nanoparticle composite systems still involve decomposition into powder and the addition of additives during electrode preparation because of the thick aerogel structure. To further enhance the capacity of the system, MoS2 was anchored onto a graphene aerogel paper and the composite was used directly as an LIB anode. The resultant additive-free MoS2/graphene aerogel paper composite exhibited long cyclic performance with 101.1% retention after 700 cycles, which demonstrates the importance of free-standing electrodes in enhancing cyclic stability.

  10. Polyaniline nanofiber/large mesoporous carbon composites as electrode materials for supercapacitors

    Science.gov (United States)

    Liu, Huan; Xu, Bin; Jia, Mengqiu; Zhang, Mei; Cao, Bin; Zhao, Xiaonan; Wang, Yu

    2015-03-01

    A composite of polyaniline nanofiber/large mesoporous carbon (PANI-F/LMC) hybrid was prepared by an in situ chemical oxidative polymerization of aniline monomer with nano-CaCO3 templated LMC as host matrix for supercapacitors. The morphology, composition and electronic structure of the composites (PANI-F/LMC) together with pure PANI nanofibers and the LMC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is found that the PANI nanofibers were incorporated into the large mesochannels of LMC with interpenetrating framework formed. Such unique structure endows the PANI-F/LMC composite with a high capacitance of 473 F g-1 at a current load of 0.1 A g-1 with good rate performance and cycling stability, suggesting its potential application in the electrode material for supercapacitors.

  11. Synthesis of mesoporous carbon as electrode material for supercapacitor by modified template method

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jia-chang; LAI Chun-yan; DAI Yang; XIE Jing-ying

    2005-01-01

    The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capacitance of the mesoporous carbons increase with the increase of mass ratio of silica sol to carbon source (glucose). A modified template method, combining silica sol template method and ZnCl2 chemical activation method, was proposed to improve the mass specific capacitance of the mesoporous carbon with an improved BET surface area. The correlation of rate capability and pore structure was studied by constant current discharge and electrochemical impedance spectroscopy. A commercially available microporous carbon was used for comparison. The result shows that mesoporous carbon with a larger pore size displays a higher rate capability. Mesoporous carbon synthesized by modified template method has both high mass specific capacitance and good rate capability.

  12. Preliminary result on the enhancement of Ufer electrodes using recycle additives materials

    Science.gov (United States)

    Zulkifli, Muhammad Haziq Aniq Bin; Ahmad, Hussein Bin

    2016-11-01

    Ground building pillars is to be used as ground rod. The pillars are design, fabricated, and formulated with new ground fillers. The additives will be used from recycle waste materials mainly from the palm oil plant process. Micro scale building pillars will be fabricated and install in the test ground at all of the location. Earth tester meter are used to measure and collect the data of the soil resistivity when the research is conducted. In collecting these data, 3-terminal methods are used to carry the measurements. This experiment will be conducted for 30 weeks and regular measurements at the test ground copper grids will be conducted to measure the ground electrode resistance. The study will mainly base on IEC 62503-3. The used of reinforcing rods and mixture of recycle additives could produce a better grounding system that are suitable and can be used in all kind of soil condition and large industries.

  13. Poly(ethylene terephthalate)-based carbons as electrode material in supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Domingo-Garcia, M.; Almazan-Almazan, M.C.; Lopez-Garzon, F.J. [Dpto de Quimica Inorganica, Facultad de Ciencias, 18071 Granada (Spain); Fernandez, J.A.; Centeno, T.A. [Instituto Nacional del Carbon-CSIC, Apartado 73, 33080 Oviedo (Spain); Stoeckli, F. [Physics Department, University of Neuchatel, Rue Emile Argand 11, CH-2009 Neuchatel (Switzerland)

    2010-06-15

    A systematic study by complementary techniques shows that PET-waste from plastic vessels is a competitive precursor of carbon electrodes for supercapacitors. PET derived-activated carbons follow the general trends observed for highly porous carbons and display specific capacitances at low current density as high as 197 F g{sup -1} in 2 M H{sub 2}SO{sub 4} aqueous electrolyte and 98 F g{sup -1} in the aprotic medium 1 M (C{sub 2}H{sub 5}){sub 4}NBF{sub 4}/acetonitrile. Additionally, high performance has also been achieved at high current densities, which confirms the potential of this type of materials for electrical energy storage. A new method based on the basic solvolysis of PET-waste and the subsequent carbonization seems to be an interesting alternative to obtain porous carbons with enhanced properties for supercapacitors. (author)

  14. Synthesis and electrochemical properties of three-dimensional graphene/polyaniline composites for supercapacitor electrode materials

    Institute of Scientific and Technical Information of China (English)

    赵文; 何大伟; 王永生; 杜翔; 忻昊

    2015-01-01

    To improve the specific capacitance and rate capability of electrode material for supercapacitors, a three-dimensional graphene/polyaniline (3DGN/PANI) composite is prepared via in situ polymerization on GN hydrogel. PANI grows on the GN surface as a thin film, and its content in the composite is controlled by the concentration of the reaction monomer. The specific capacitance of the 3DGN/PANI composite containing 10 wt%PANI reaches 322.8 F·g−1 at a current density of 1 A·g−1, nearly twice as large as that of the pure 3DGN (162.8 F·g−1). The capacitance of the composite is 307.9 F·g−1 at 30 A·g−1 (maintaining 95.4%), and 89%retention after 500 cycles. This study demonstrates the exciting potential of 3DGN/PANI with high capacitance, excellent rate capability and long cycling life for supercapacitors.

  15. S-functionalized MXenes as electrode materials for Li-ion batteries

    KAUST Repository

    Zhu, Jiajie

    2016-09-03

    MXenes are promising electrode materials for Li-ion batteries because of their high Li capacities and cycling rates. We use density functional theory to investigate the structural and energy storage properties of Li decorated Zr2C and Zr2CX2 (X = F, O and S). We find for Zr2C and Zr2CS2 high Li specific capacities and low diffusion barriers. To overcome the critical drawbacks of the OH, F, and O groups introduced during the synthesis we propose substitution by S groups and demonstrate that an exchange reaction is indeed possible. Zr2CS2 shows a similar Li specific capacity as Zr2CO2 but a substantially reduced diffusion barrier. © 2016 Elsevier Ltd

  16. Synthesis, characterization, and electrochemical investigation of novel electrode materials for lithium ion batteries

    Science.gov (United States)

    Kerr, Tracy Alexandra

    2002-08-01

    As the demand for better energy storage devices increases, finding new materials capable of improvement on existing technology becomes essential. Within this body of work, several new electrode materials of different structure type have been synthesized, characterized, and evaluated for their lithium insertion/deinsertion behavior in lithium ion batteries. Nanocomposites of novel alloy, and convertible oxide anode materials have been studied. Nanoparticles of Ge and Sn that are able to form lithium rich alloys have been synthesized, and their low potential lithium insertion behavior studied. In order to inhibit agglomeration of the tiny particles, a novel synthesis route was designed to attach ionically conducting polymers to their surfaces. Characterization by a combination of techniques (XRD, TEM, SEM and FTIR spectroscopy) verified the existence of nanoparticles embedded in a polymer matrix, albeit with some impurities. Electrochemical data show that even when the lithium insertion capacity within these materials is high, the process is extremely irreversible as lithium ions become trapped within the matrix, and only a very small anodic capacity is realized. The first convertible polymer/oxide nanocomposite (poly(para-phenylene)/MoO 3) to be evaluated as an anode material was synthesized using a novel surfactant mediated method. XRD data indicated a 5.2 A increase in the MoO3 layer spacing to 12.1 A after polymer incorporation. Low potential electrochemical insertion properties show that the polymer/oxide nanocomposite behaves in a similar manner to the host MoO3 material. A variety of cathode materials were also synthesized and evaluated for their high potential lithium insertion properties. A comparative study on the effect that synthetic procedure may have on the electrochemical properties of the poly(aniline)/MoO3 cathode material have been studied. Poly(aniline)/MoO 3 nanocomposites have been synthesized from a solution insertion route and via hydrothermal

  17. Simple Synthesis of Molybdenum Disulfide/Reduced Graphene Oxide Composite Hollow Microspheres as Supercapacitor Electrode Material

    Directory of Open Access Journals (Sweden)

    Wei Xiao

    2016-09-01

    Full Text Available MoS2/RGO composite hollow microspheres were hydrothermally synthesized by using SiO2/GO microspheres as a template, which were obtained via the sonication-assisted interfacial self-assembly of tiny GO sheets on positively charged SiO2 microspheres. The structure, morphology, phase, and chemical composition of MoS2/RGO hollow microspheres were systematically investigated by a series of techniques such as FE-SEM, TEM, XRD, TGA, BET, and Raman characterizations, meanwhile, their electrochemical properties were carefully evaluated by CV, GCD, and EIS measurements. It was found that MoS2/RGO hollow microspheres possessed unique porous hollow architecture with high-level hierarchy and large specific surface area up to 63.7 m2·g−1. When used as supercapacitor electrode material, MoS2/RGO hollow microspheres delivered a maximum specific capacitance of 218.1 F·g−1 at the current density of 1 A·g−1, which was much higher than that of contrastive bare MoS2 microspheres developed in the present work and most of other reported MoS2-based materials. The enhancement of supercapacitive behaviors of MoS2/RGO hollow microspheres was likely due to the improved conductivity together with their distinct structure and morphology, which not only promoted the charge transport but also facilitated the electrolyte diffusion. Moreover, MoS2/RGO hollow microsphere electrode displayed satisfactory long-term stability with 91.8% retention of the initial capacitance after 1000 charge/discharge cycles at the current density of 3 A·g−1, showing excellent application potential.

  18. Graphene nanoplatelets with selectively functionalized edges as electrode material for electrochemical energy storage.

    Science.gov (United States)

    Bhattacharjya, Dhrubajyoti; Jeon, In-Yup; Park, Hyean-Yeol; Panja, Tandra; Baek, Jong-Beom; Yu, Jong-Sung

    2015-05-26

    In recent years, graphene-based materials have been in the forefront as electrode material for electrochemical energy generation and storage. Despite this prevalent interest, synthesis procedures have not attained three important efficiency requirements, that is, cost, energy, and eco-friendliness. In this regard, in the present work, graphene nanoplatelets with selectively functionalized edges (XGnPs) are prepared through a simple, eco-friendly and efficient method, which involves ball milling of graphite in the presence of hydrogen (H2), bromine (Br2), and iodine (I2). The resultant HGnP, BrGnP, and IGnP reveal significant exfoliation of graphite layers, as evidenced by high BET surface area of 414, 595, and 772 m(2) g(-1), respectively, in addition to incorporation of H, Br, and I along with other oxygen-containing functional groups at the graphitic edges. The BrGnP and IGnP are also found to contain 4.12 and 2.20 at % of Br and I, respectively in the graphene framework. When tested as supercapacitor electrode, all XGnPs show excellent electrochemical performance in terms of specific capacitance and durability at high current density and long-term operation. Among XGnPs, IGnP delivers superior performance of 172 F g(-1) at 1 A g(-1) compared with 150 F g(-1) for BrGnP and 75 F g(-1) for HGnP because the large surface area and high surface functionality in the IGnP give rise to the outstanding capacitive performance. Moreover, all XGnPs show excellent retention of capacitance at high current density of 10 A g(-1) and for long-term operation up to 1000 charge-discharge cycles.

  19. Few-layer MoS2-anchored graphene aerogel paper for free-standing electrode materials

    Science.gov (United States)

    Lee, Wee Siang Vincent; Peng, Erwin; Loh, Tamie Ai Jia; Huang, Xiaolei; Xue, Jun Min

    2016-04-01

    To reduce the reliance on polymeric binders, conductive additives, and metallic current collectors during the electrode preparation process, as well as to assess the true performance of lithium ion battery (LIB) anodes, a free-standing electrode has to be meticulously designed. Graphene aerogel is a popular scaffolding material that has been widely used with embedded nanoparticles for application in LIB anodes. However, the current graphene aerogel/nanoparticle composite systems still involve decomposition into powder and the addition of additives during electrode preparation because of the thick aerogel structure. To further enhance the capacity of the system, MoS2 was anchored onto a graphene aerogel paper and the composite was used directly as an LIB anode. The resultant additive-free MoS2/graphene aerogel paper composite exhibited long cyclic performance with 101.1% retention after 700 cycles, which demonstrates the importance of free-standing electrodes in enhancing cyclic stability.To reduce the reliance on polymeric binders, conductive additives, and metallic current collectors during the electrode preparation process, as well as to assess the true performance of lithium ion battery (LIB) anodes, a free-standing electrode has to be meticulously designed. Graphene aerogel is a popular scaffolding material that has been widely used with embedded nanoparticles for application in LIB anodes. However, the current graphene aerogel/nanoparticle composite systems still involve decomposition into powder and the addition of additives during electrode preparation because of the thick aerogel structure. To further enhance the capacity of the system, MoS2 was anchored onto a graphene aerogel paper and the composite was used directly as an LIB anode. The resultant additive-free MoS2/graphene aerogel paper composite exhibited long cyclic performance with 101.1% retention after 700 cycles, which demonstrates the importance of free-standing electrodes in enhancing cyclic

  20. B4C as a stable non-carbon-based oxygen electrode material for lithium-oxygen batteries

    Energy Technology Data Exchange (ETDEWEB)

    Song, Shidong; Xu, Wu; Cao, Ruiguo; Luo, Langli; Engelhard, Mark H.; Bowden, Mark E.; Liu, Bin; Estevez, Luis; Wang, Chong-Min; Zhang, Ji-Guang

    2017-01-19

    Lithium-oxygen (Li-O2) batteries have extremely high theoretical specific capacities and energy densities when compared with Li-ion batteries. However, the instability of both electrolyte and carbon-based oxygen electrode related to the nucleophilic attack of reduced oxygen species during oxygen reduction reaction and the electrochemical oxidation during oxygen evolution reaction are recognized as the major challenges in this field. Here we report the application of boron carbide (B4C) as the non-carbon based oxygen electrode material for aprotic Li-O2 batteries. B4C has high resistance to chemical attack, good conductivity, excellent catalytic activity and low density that are suitable for battery applications. The electrochemical activity and chemical stability of B4C are systematically investigated in aprotic electrolyte. Li-O2 cells using B4C based air electrodes exhibit better cycling stability than those used TiC based air electrode in 1 M LiTf-Tetraglyme electrolyte. The degradation of B4C based electrode is mainly due to be the loss of active sites on B4C electrode during cycles as identified by the structure and composition characterizations. These results clearly demonstrate that B4C is a very promising alternative oxygen electrode material for aprotic Li-O2 batteries. It can also be used as a standard electrode to investigate the stability of electrolytes.

  1. Impulse space charge and dielectric characteristics of an Al2O3 nanoparticle suspension in propylene carbonate using various electrode materials

    Directory of Open Access Journals (Sweden)

    Qing Yang

    2016-09-01

    Full Text Available We tested the impulse breakdown voltage of Al2O3 “nano-modified” propylene carbonate between different electrode materials. At any given concentration, the breakdown voltage was highest with stainless steel electrodes, followed by copper, and then aluminum. The space charge and electric field distributions were measured too. Results show that less space charge was injected by the electrodes, and the electric field was less distorted, than in pure propylene carbonate. However, the hoped-for reduction of the influence of the electrodes did not take place. Substantial differences in the space charge density and electric field distortion remained between the different electrode materials.

  2. Hydrothermal synthesis of nanostructured graphene/polyaniline composites as high-capacitance electrode materials for supercapacitors

    Science.gov (United States)

    Wang, Ronghua; Han, Meng; Zhao, Qiannan; Ren, Zonglin; Guo, Xiaolong; Xu, Chaohe; Hu, Ning; Lu, Li

    2017-03-01

    As known to all, hydrothermal synthesis is a powerful technique for preparing inorganic and organic materials or composites with different architectures. In this reports, by controlling hydrothermal conditions, nanostructured polyaniline (PANi) in different morphologies were composited with graphene sheets (GNS) and used as electrode materials of supercapacitors. Specifically, ultrathin PANi layers with total thickness of 10-20 nm are uniformly composited with GNS by a two-step hydrothermal-assistant chemical oxidation polymerization process; while PANi nanofibers with diameter of 50~100 nm are obtained by a one-step direct hydrothermal process. Benefitting from the ultrathin layer and porous structure, the sheet-like GNS/PANi composites can deliver specific capacitances of 532.3 to 304.9 F/g at scan rates of 2 to 50 mV/s. And also, this active material showed very good stability with capacitance retention as high as ~99.6% at scan rate of 50 mV/s, indicating a great potential for using in supercapacitors. Furthermore, the effects of hydrothermal temperatures on the electrochemical performances were systematically studied and discussed.

  3. Solvothermal synthesis of a polyaniline nanocomposite – a prospective biosensor electrode material

    Directory of Open Access Journals (Sweden)

    R. K. Agrawalla

    2016-09-01

    Full Text Available Polyaniline (PANI is the most important conducting polymer with excellent electrochemical properties. So PANIbased biosensors may find wide applications in medical diagnostics. We report here a ternary nanocomposite of gold nanoparticle-decorated single- walled carbon nanotubes (SWCNTs embedded in sulfonated polyaniline matrix, prepared using a simple solvothermal chemical route. The structural and morphological characteristics have been determined by electron microscopy, X-ray diffraction and Raman spectroscopy. Optical characteristics of the nanocomposite have been determined by ultraviolet (UV-visible absorption spectroscopy and photoluminescence spectroscopy. The direct current (DC-conductivity measurement of the material shows a significant increase in electrical conductivity at 353 K from 7.80·10–2 S/m for pure SPANI to 10.91 S/m for the 3-phase nanocomposite as synthesized in the present investigations. Thus the incorporation of SWCNT/Au nanohybrid fibers in the PANI matrix enhanced its electrical properties. Sulfonation increased the processability of the material, as the samples have now been found to be soluble in water and common organic solvents like DMSO. Such a functional nanocomposite will make an excellent biosensor electrode material.

  4. Hydrothermal synthesis of nanostructured graphene/polyaniline composites as high-capacitance electrode materials for supercapacitors

    Science.gov (United States)

    Wang, Ronghua; Han, Meng; Zhao, Qiannan; Ren, Zonglin; Guo, Xiaolong; Xu, Chaohe; Hu, Ning; Lu, Li

    2017-01-01

    As known to all, hydrothermal synthesis is a powerful technique for preparing inorganic and organic materials or composites with different architectures. In this reports, by controlling hydrothermal conditions, nanostructured polyaniline (PANi) in different morphologies were composited with graphene sheets (GNS) and used as electrode materials of supercapacitors. Specifically, ultrathin PANi layers with total thickness of 10–20 nm are uniformly composited with GNS by a two-step hydrothermal-assistant chemical oxidation polymerization process; while PANi nanofibers with diameter of 50~100 nm are obtained by a one-step direct hydrothermal process. Benefitting from the ultrathin layer and porous structure, the sheet-like GNS/PANi composites can deliver specific capacitances of 532.3 to 304.9 F/g at scan rates of 2 to 50 mV/s. And also, this active material showed very good stability with capacitance retention as high as ~99.6% at scan rate of 50 mV/s, indicating a great potential for using in supercapacitors. Furthermore, the effects of hydrothermal temperatures on the electrochemical performances were systematically studied and discussed. PMID:28291246

  5. Nitrogen-doped reduced graphene oxide as electrode material for high rate supercapacitors

    Science.gov (United States)

    Śliwak, Agata; Grzyb, Bartosz; Díez, Noel; Gryglewicz, Grażyna

    2017-03-01

    Nitrogen-doped reduced graphene oxides (N-rGOs) have been synthesized at various temperatures by a facile hydrothermal route involving the doping of an aqueous graphene oxide dispersion with amitrole. The N-rGOs had a nitrogen content ranging from 10.9 to 13.4 at%, which is among the highest reported for this type of material. The predominant nitrogen species were pyridinic followed by amide/amine, pyrrolic, and quaternary nitrogen. Cyclic voltammetry and impedance spectroscopy measurements performed on the N-doped and nitrogen-free samples revealed that nitrogen fixation provided the material with pseudocapacitive behaviour and improved ion diffusion and charge propagation. A high specific capacitance of 244 F g-1 was obtained at a high scan rate of 100 mV s-1 for the N-rGO with the highest nitrogen content. An outstanding rate capability for the N-rGO, with increasing scan rates, of 98% was obtained, while only 70% was obtained for the non-doped rGO. 92% of the initial capacitance was maintained over 5000 charge/discharge cycles due to the high stability of the electrochemically active nitrogen moieties. Hydrothermal synthesis using amitrole as a nitrogen dopant represents a simple route for the synthesis of graphene with very high nitrogen content and exceptional behaviour for use as electrode material in high-power supercapacitors.

  6. Electrochemical characterizati on of MnO2 as electrocatalytic energy material for fuel cell electrode

    Institute of Scientific and Technical Information of China (English)

    Subir Paul; Asmita Ghosh

    2015-01-01

    Development of inexpensive non Pt based high electrocatalytic energy materials is the need of the hour for fuel cell electrode to produce clean alternative green energy from synthesized bio alcohol using biomass.MnO2 , electro synthesized at different current density is found to be well performed electrocatalytic material, comparable to Pt, with higher current density, very low overvoltage for the electrochemical oxidation of methanol.From EIS study, the polarization resistance of the coate d MnO2 is found to be much low and electrical double layer capacitance is high, the effect increases with increase in current density of electro deposition.XRD, EDX and AAS analysis confirm the MnO2 depositio n.Them orphology of SEM im agese xhibits an enhanced 3D effective sub strat e area, for elect ro oxidation oft he fuel.A few nano structured grains of the deposite d MnO2 is also observed at higher current density.The fact supports that a high energet ic ine xpensive electroc atalytic material has beenf ound for fu el cell electrodet o synthesis renewable energy from methanol fuel.

  7. Production method of raw material dispersion liquid for reaction layer of gas diffusion electrode

    Energy Technology Data Exchange (ETDEWEB)

    Furuya, Choichi; Motoo, Satoshi

    1987-10-13

    Heretofore, in order to make a raw material dispersion liquid of a reaction layer of a gas diffusion electrode, water repellent carbon, polytetrafluoroethylene, water and a surface active agent are mixed, then a cake is made by filtering this mixed liquid and afterwards the cake is heated and dried before being crushed. Since this crushing is done mechanically, homogeneous fine raw material powders cannot be obtained. Accordingly, even when a reaction layer is made by sintering a mixture of this powder, hydrophilic carbon black or hydrophilic carbon black carrying catalyst, and polytetrafluoroethylene, the hydrophilic part and the water repellent part are not distributed homogeneously and the catalytic performance of the reaction layer declines. In order to solve this, this invention proposes a production method that water repellent carbon black, polyterafluoroethylene, water and a surface active agent are mixed, then this mixture is frozen so that the surface active agent may not become active and homogeneous condensed cores of water repellent carbon black and polytetrafluoroethylene powders may be formed, and afterwards a homogeneous fine raw material dispersion liquid is made from thawing the condensed cores without change by thawing the above frozen mixture.

  8. Impedance spectroscopic analysis of composite electrode from activated carbon/conductive materials/ruthenium oxide for supercapacitor applications

    Energy Technology Data Exchange (ETDEWEB)

    Taer, E.; Awitdrus,; Farma, R. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Department of Physics, Faculty of Mathematics and Natural Sciences, University of Riau, 28293 Pekanbaru, Riau (Indonesia); Deraman, M., E-mail: madra@ukm.my; Talib, I. A.; Ishak, M. M.; Omar, R.; Dolah, B. N. M.; Basri, N. H.; Othman, M. A. R. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Kanwal, S. [ICCBS, H.E.J. Research Institute of Chemistry, University of Karachi, 75270 Karachi (Pakistan)

    2015-04-16

    Activated carbon powders (ACP) were produced from the KOH treated pre-carbonized rubber wood sawdust. Different conductive materials (graphite, carbon black and carbon nanotubes (CNTs)) were added with a binder (polivinylidene fluoride (PVDF)) into ACP to improve the supercapacitive performance of the activated carbon (AC) electrodes. Symmetric supercapacitor cells, fabricated using these AC electrodes and 1 molar H{sub 2}SO{sub 4} electrolyte, were analyzed using a standard electrochemical impedance spectroscopy technique. The addition of graphite, carbon black and CNTs was found effective in reducing the cell resistance from 165 to 68, 23 and 49 Ohm respectively, and increasing the specific capacitance of the AC electrodes from 3 to 7, 17, 32 F g{sup −1} respectively. Since the addition of CNTs can produce the highest specific capacitance, CNTs were chosen as a conductive material to produce AC composite electrodes that were added with 2.5 %, 5 % and 10 % (by weight) electro-active material namely ruthenium oxide; PVDF binder and CNTs contents were kept at 5 % by weight in each AC composite produced. The highest specific capacitance of the cells obtained in this study was 86 F g{sup −1}, i.e. for the cell with the resistance of 15 Ohm and composite electrode consists of 5 % ruthenium oxide.

  9. Band Gap Engineering of Boron Nitride by Graphene and Its Application as Positive Electrode Material in Asymmetric Supercapacitor Device.

    Science.gov (United States)

    Saha, Sanjit; Jana, Milan; Khanra, Partha; Samanta, Pranab; Koo, Hyeyoung; Murmu, Naresh Chandra; Kuila, Tapas

    2015-07-08

    Nanostructured hexagonal boron nitride (h-BN)/reduced graphene oxide (RGO) composite is prepared by insertion of h-BN into the graphene oxide through hydrothermal reaction. Formation of the super lattice is confirmed by the existence of two separate UV-visible absorption edges corresponding to two different band gaps. The composite materials show enhanced electrical conductivity as compared to the bulk h-BN. A high specific capacitance of ∼824 F g(-1) is achieved at a current density of 4 A g(-1) for the composite in three-electrode electrochemical measurement. The potential window of the composite electrode lies in the range from -0.1 to 0.5 V in 6 M aqueous KOH electrolyte. The operating voltage is increased to 1.4 V in asymmetric supercapacitor (ASC) device where the thermally reduced graphene oxide is used as the negative electrode and the h-BN/RGO composite as the positive electrode. The ASC exhibits a specific capacitance of 145.7 F g(-1) at a current density of 6 A g(-1) and high energy density of 39.6 W h kg(-1) corresponding to a large power density of ∼4200 W kg(-1). Therefore, a facile hydrothermal route is demonstrated for the first time to utilize h-BN-based composite materials as energy storage electrode materials for supercapacitor applications.

  10. Amorphous carbon nitride as an alternative electrode material in electroanalysis: Simultaneous determination of dopamine and ascorbic acid

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Roberta A., E-mail: roantigo@hotmail.com [Departamento de Química, Universidade Federal de São Carlos, C.P. 676, 13560-970 São Carlos, SP (Brazil); Matos, Roberto [Departamento de Química, Universidade Federal de São Carlos, C.P. 676, 13560-970 São Carlos, SP (Brazil); Benchikh, Abdelkader [LECVE, Faculté de la Technologie, Département de Génie des Procédés, Université Abderrahmane MIRA, Béjaïa (Algeria); LISE UPR 15 du CNRS, Université Pierre et Marie Curie, 4, Place Jussieu, 75005 Paris (France); Saidani, Boualem [LECVE, Faculté de la Technologie, Département de Génie des Procédés, Université Abderrahmane MIRA, Béjaïa (Algeria); Debiemme-Chouvy, Catherine [LISE UPR 15 du CNRS, Université Pierre et Marie Curie, 4, Place Jussieu, 75005 Paris (France); Deslouis, Claude, E-mail: claude.deslouis@upmc.fr [LISE UPR 15 du CNRS, Université Pierre et Marie Curie, 4, Place Jussieu, 75005 Paris (France); Rocha-Filho, Romeu C.; Fatibello-Filho, Orlando [Departamento de Química, Universidade Federal de São Carlos, C.P. 676, 13560-970 São Carlos, SP (Brazil)

    2013-10-03

    Graphical abstract: -- Highlights: •a-CN{sub x} films are a new class of electrodic carbon materials that present several properties similar to those of BDD films. •a-CN{sub x} and BDD were used as working electrodes for simultaneous determination of DA and AA. •Electrochemical pretreatments on a-CN{sub x} or BDD modified the nature of the surface terminations. •An anodic pretreatment in 0.1 mol L{sup −1} KOH was necessary to attain an adequate separation of the DA and AA oxidation potential peaks. •For the first time in the literature, the use of an a-CN{sub x} electrode in a complete electroanalytical procedure is reported. -- Abstract: Boron-doped diamond (BDD) films are excellent electrode materials, whose electrochemical activity for some analytes can be tuned by controlling their surface termination, most commonly either to predominantly hydrogen or oxygen. This tuning can be accomplished by e.g. suitable cathodic or anodic electrochemical pretreatments. Recently, it has been shown that amorphous carbon nitride (a-CN{sub x}) films may present electrochemical characteristics similar to those of BDD, including the influence of surface termination on their electrochemical activity toward some analytes. In this work, we report for the first time a complete electroanalytical method using an a-CN{sub x} electrode. Thus, an a-CN{sub x} film deposited on a stainless steel foil by DC magnetron sputtering is proposed as an alternative electrode for the simultaneous determination of dopamine (DA) and ascorbic acid (AA) in synthetic biological samples by square-wave voltammetry. The obtained results are compared with those attained using a BDD electrode. For both electrodes, a same anodic pretreatment in 0.1 mol L{sup −1} KOH was necessary to attain an adequate and equivalent separation of the DA and AA oxidation potential peaks of about 330 mV. The detection limits obtained for the simultaneous determination of these analytes using the a-CN{sub x

  11. Evaluation of Niobium as Candidate Electrode Material for DC High Voltage Photoelectron Guns

    Science.gov (United States)

    BastaniNejad, M.; Mohamed, Abdullah; Elmustafa, A. A.; Adderley, P.; Clark, J.; Covert, S.; Hansknecht, J.; Hernandez-Garcia, C.; Poelker, M.; Mammei, R.; hide

    2012-01-01

    The field emission characteristics of niobium electrodes were compared to those of stainless steel electrodes using a DC high voltage field emission test apparatus. A total of eight electrodes were evaluated: two 304 stainless steel electrodes polished to mirror-like finish with diamond grit and six niobium electrodes (two single-crystal, two large-grain, and two fine-grain) that were chemically polished using a buffered-chemical acid solution. Upon the first application of high voltage, the best large-grain and single-crystal niobium electrodes performed better than the best stainless steel electrodes, exhibiting less field emission at comparable voltage and field strength. In all cases, field emission from electrodes (stainless steel and/or niobium) could be significantly reduced and sometimes completely eliminated, by introducing krypton gas into the vacuum chamber while the electrode was biased at high voltage. Of all the electrodes tested, a large-grain niobium electrode performed the best, exhibiting no measurable field emission (< 10 pA) at 225 kV with 20 mm cathode/anode gap, corresponding to a field strength of 18:7 MV/m.

  12. Development of Nano-structured Electrode Materials for High Performance Energy Storage System

    Science.gov (United States)

    Huang, Zhendong

    Systematic studies have been done to develop a low cost, environmental-friendly facile fabrication process for the preparation of high performance nanostructured electrode materials and to fully understand the influence factors on the electrochemical performance in the application of lithium ion batteries (LIBs) or supercapacitors. For LIBs, LiNi1/3Co1/3Mn1/3O2 (NCM) with a 1D porous structure has been developed as cathode material. The tube-like 1D structure consists of inter-linked, multi-facet nanoparticles of approximately 100-500nm in diameter. The microscopically porous structure originates from the honeycomb-shaped precursor foaming gel, which serves as self-template during the stepwise calcination process. The 1D NCM presents specific capacities of 153, 140, 130 and 118mAh·g-1 at current densities of 0.1C, 0.5C, 1C and 2C, respectively. Subsequently, a novel stepwise crystallization process consisting of a higher crystallization temperature and longer period for grain growth is employed to prepare single crystal NCM nanoparticles. The modified sol-gel process followed by optimized crystallization process results in significant improvements in chemical and physical characteristics of the NCM particles. They include a fully-developed single crystal NCM with uniform composition and a porous NCM architecture with a reduced degree of fusion and a large specific surface area. The NCM cathode material with these structural modifications in turn presents significantly enhanced specific capacities of 173.9, 166.9, 158.3 and 142.3mAh·g -1 at 0.1C, 0.5C, 1C and 2C, respectively. Carbon nanotube (CNT) is used to improve the relative low power capability and poor cyclic stability of NCM caused by its poor electrical conductivity. The NCM/CNT nanocomposites cathodes are prepared through simply mixing of the two component materials followed by a thermal treatment. The CNTs were functionalized to obtain uniformly-dispersed MWCNTs in the NCM matrix. The electrochemical

  13. Cerium oxide nanoparticles/multi-wall carbon nanotubes composites: Facile synthesis and electrochemical performances as supercapacitor electrode materials

    Science.gov (United States)

    Deng, Dongyang; Chen, Nan; Li, Yuxiu; Xing, Xinxin; Liu, Xu; Xiao, Xuechun; Wang, Yude

    2017-02-01

    Cerium oxide nanoparticles/multi-wall carbon nanotubes (MWCNTs) composites are synthesized by a facile hydrothermal method without any surfactant or template. The morphology and microstructure of samples are examined by scanning electron microscopy (SEM), transition electron microscopy (TEM), X-ray diffraction (XRD), Raman spectrum and X-ray photoelectron spectroscopy (XPS). Electrochemical properties of the MWCNTs, the pure CeO2, and the CeO2/MWCNTs nanocomposites electrodes are investigated by cyclic voltammetry (CV), galvanostatic charge/discharge (GDC) and electrochemical impedance spectroscopy (EIS) measurements. The CeO2/MWCNTs nanocomposite (at the mole ratio of 1:1) electrode exhibits much larger specific capacitance compared with both the MWCNTs electrode and the pure CeO2 electrode and significantly improves cycling stability compared to the pure CeO2 electrode. The CeO2/MWCNTs nanocomposite (at the mole ratio of 1:1) achieves a specific capacitance of 455.6 F g-1 at the current density of 1 A g-1. Therefore, the as prepared CeO2/MWCNTs nanocomposite is a promising electrode material for high-performance supercapacitors.

  14. Amorphous carbon nitride as an alternative electrode material in electroanalysis: simultaneous determination of dopamine and ascorbic acid.

    Science.gov (United States)

    Medeiros, Roberta A; Matos, Roberto; Benchikh, Abdelkader; Saidani, Boualem; Debiemme-Chouvy, Catherine; Deslouis, Claude; Rocha-Filho, Romeu C; Fatibello-Filho, Orlando

    2013-10-03

    Boron-doped diamond (BDD) films are excellent electrode materials, whose electrochemical activity for some analytes can be tuned by controlling their surface termination, most commonly either to predominantly hydrogen or oxygen. This tuning can be accomplished by e.g. suitable cathodic or anodic electrochemical pretreatments. Recently, it has been shown that amorphous carbon nitride (a-CNx) films may present electrochemical characteristics similar to those of BDD, including the influence of surface termination on their electrochemical activity toward some analytes. In this work, we report for the first time a complete electroanalytical method using an a-CNx electrode. Thus, an a-CNx film deposited on a stainless steel foil by DC magnetron sputtering is proposed as an alternative electrode for the simultaneous determination of dopamine (DA) and ascorbic acid (AA) in synthetic biological samples by square-wave voltammetry. The obtained results are compared with those attained using a BDD electrode. For both electrodes, a same anodic pretreatment in 0.1 mol L(-1) KOH was necessary to attain an adequate and equivalent separation of the DA and AA oxidation potential peaks of about 330 mV. The detection limits obtained for the simultaneous determination of these analytes using the a-CNx electrode were 0.0656 μmol L(-1) for DA and 1.05 μmol L(-1) for AA, whereas with the BDD electrode these values were 0.283 μmol L(-1) and 0.968 μmol L(-1), respectively. Furthermore, the results obtained in the analysis of the analytes in synthetic biological samples were satisfactory, attesting the potential application of the a-CNx electrode in electroanalysis.

  15. Synthesis of NiMnO3/C nano-composite electrode materials for electrochemical capacitors.

    Science.gov (United States)

    Kakvand, Pejman; Rahmanifar, Mohammad Safi; El-Kady, Maher F; Pendashteh, Afshin; Kiani, Mohammad Ali; Hashami, Masumeh; Najafi, Mohsen; Abbasi, Ali; Mousavi, Mir F; Kaner, Richard B

    2016-08-05

    Demand for high-performance energy storage materials has motivated research activities to develop nano-engineered composites that benefit from both high-rate and high-capacitance materials. Herein, NiMnO3 (NMO) nanoparticles have been synthesized through a facile co-precipitation method. As-prepared NMO samples are then employed for the synthesis of nano-composites with graphite (Gr) and reduced graphene oxide (RGO). Various samples, including pure NMO, NMO-graphite blend, as well as NMO/Gr and NMO/RGO nano-composites have been electrochemically investigated as active materials in supercapacitors. The NMO/RGO sample exhibited a high specific capacitance of 285 F g(-1) at a current density of 1 A g(-1), much higher than the other samples (237 F g(-1) for NMO/Gr, 170 F g(-1) for NMO-Gr and 70 F g(-1) for NMO). Moreover, the NMO/RGO nano-composite has shown excellent cycle stability with a 93.5% capacitance retention over 1000 cycles at 2 A g(-1) and still delivered around 87% of its initial capacitance after cycling for 4000 cycles. An NMO/RGO composite was assessed in practical applications by assembling NMO/RGO//NMO/RGO symmetric devices, exhibiting high specific energy (27.3 Wh kg(-1)), high specific power (7.5 kW kg(-1)), and good cycle stability over a broad working voltage of 1.5 V. All the obtained results demonstrate the promise of NMO/RGO nano-composite as a high-performance electrode material for supercapacitors.

  16. Lanthanum chromite materials as potential symmetrical electrodes for Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Ruiz-Morales, J. C.

    2007-08-01

    Full Text Available A commonly used interconnector material has been tested as electrode for a new concept of Solid Oxide Fuel Cell, where the same material could be used, simultaneously, as interconnector, anode and cathode. We have found that a typical substituted chromite, such as La0.7Ca0.3CrO3-δ (LCC can be considered a good candidate for such configuration, due to its high electronic conductivity in both reducing and oxidising conditions, and moderate catalytic properties for oxygen reduction and hydrogen oxidation. The symmetrical design renders performances of 100 mWcm-2 at 950ºC, using O2 and H2 as oxidant and fuel respectively. Performances exceeding 300 mWcm-2 can be predicted for a 100μm-thick YSZ electrolyte.

    Un material comúnmente utilizado como interconector ha sido probado como electrodo para un nuevo concepto de Pila de Combustible de Óxidos Sólido, en el cual el mismo material se utiliza, simultáneamente, como interconector, ánodo y cátodo. Hemos encontrado que una cromita típica como La0.7Ca0.3CrO3-δ (LCC puede ser considerada una buena candidata para dicha configuración, debido a sus altas conductividades eléctricas tanto en condiciones reductoras como oxidantes y una aceptable actividad catalítica para la reducción del oxígeno y la oxidación del hidrógeno. El diseño simétrico permite obtener rendimientos del orden de 100mWcm-2 a 950ºC, utilizando O2 e H2 como oxidante y combustible, respectivamente. Rendimientos que superan los 300mWcm-2 pueden predecirse para pilas con electrolitos de YSZ de 100 μm de grosor.

  17. Kinetic modelling of molten carbonate fuel cells: Effects of cathode water and electrode materials

    Science.gov (United States)

    Arato, E.; Audasso, E.; Barelli, L.; Bosio, B.; Discepoli, G.

    2016-10-01

    Through previous campaigns the authors developed a semi-empirical kinetic model to describe MCFC performance for industrial and laboratory simulation. Although effective in a wide range of operating conditions, the model was validated for specific electrode materials and dry feeding cathode compositions. The new aim is to prove that with appropriate improvements it is possible to apply the model to MCFC provided by different suppliers and to new sets of reactant gases. Specifically, this paper describes the procedures to modify the model to switch among different materials and identify a new parameter taking into account the effects of cathode water vapour. The new equation is integrated as the kinetic core within the SIMFC (SIMulation of Fuel Cells) code, an MCFC 3D model set up by the PERT group of the University of Genova, for reliability test. Validation is performed using data collected through tests carried out at the University of Perugia using single cells. The results are discussed giving examples of the simulated performance with varying operating conditions. The final formulation average percentage error obtained for all the simulated cases with respect to experimental results is maintained around 1%, despite the difference between the basic and the new conditions and facilities.

  18. Recent Advancements in Flexible and Stretchable Electrodes for Electromechanical Sensors: Strategies, Materials, and Features.

    Science.gov (United States)

    Zhao, Songfang; Li, Jinhui; Cao, Duxia; Zhang, Guoping; Li, Jia; Li, Kui; Yang, Yang; Wang, Wei; Jin, Yufeng; Sun, Rong; Wong, Ching-Ping

    2017-03-30

    Stretchable and flexible sensors attached onto the surface of the human body can perceive external stimuli, thus attracting extensive attention due to their lightweight, low modulus, low cost, high flexibility, and stretchability. Recently, a myriad of efforts have been devoted to improving the performance and functionality of wearable sensors. Herein, this review focuses on recent remarkable advancements in the development of flexible and stretchable sensors. Multifunction of these wearable sensors is realized by incorporating some desired features (e.g., self-healing, self-powering, linearity, and printing). Next, focusing on the characteristics of carbon nanomaterials, nanostructured metal, conductive polymer, or their hybrid composites, two major strategies (e.g., materials that stretch and structures that stretch) and diverse design approaches have been developed to achieve highly flexible and stretchable electrodes. Strain sensing performances of recently reported sensors indicate that the appropriate choice of geometric engineering as well as intrinsically stretchable materials is essential for high-performance strain sensing. Finally, some important directions and challenges of a fully sensor-integrated wearable platform are proposed to realize their potential applications for human motion monitoring and human-machine interfaces.

  19. α MnMoO₄/graphene hybrid composite: high energy density supercapacitor electrode material.

    Science.gov (United States)

    Ghosh, Debasis; Giri, Soumen; Moniruzzaman, Md; Basu, Tanya; Mandal, Manas; Das, Chapal Kumar

    2014-07-28

    A unique and cost effective hydrothermal procedure has been carried out for the synthesis of hexahedron shaped α MnMoO4 and its hybrid composite with graphene using three different weight percentages of graphene. Characterization techniques, such as XRD, Raman and FTIR analysis, established the phase and formation of the composite. The electrochemical characterization of the pseudocapacitive MnMoO4 and the MnMoO4/graphene composites in 1 M Na2SO4 displayed highest specific capacitances of 234 F g(-1) and 364 F g(-1), respectively at a current density of 2 A g(-1). Unlike many other pseudocapacitive electrode materials our prepared materials responded in a wide range of working potentials of (-)1 V to (+)1 V, which indeed resulted in a high energy density without substantial loss of power density. The highest energy densities of 130 Wh kg(-1) and 202.2 Wh kg(-1) were achieved, respectively for the MnMoO4 and the MnMoO4/graphene composite at a constant power delivery rate of 2000 W kg(-1). The synergistic effect of the graphene with the pseudocapacitive MnMoO4 caused an increased cycle stability of 88% specific capacitance retention after 1000 consecutive charge discharge cycles at 8 A g(-1) constant current density, which was higher than the virgin MnMoO4 with 84% specific capacitance retention.

  20. Double-shell CuS nanocages as advanced supercapacitor electrode materials

    Science.gov (United States)

    Guo, Jinxue; Zhang, Xinqun; Sun, Yanfang; Zhang, Xiaohong; Tang, Lin; Zhang, Xiao

    2017-07-01

    Metal sulfides hollow structures are advanced materials for energy storage applications of lithium-ion batteries and supercapacitors. However, constructing hollow metal sulfides with specific features, such as multi-shell and non-spherical shape, still remains great challenge. In this work, we firstly demonstrate the synthesis of CuS double-shell hollow nanocages using Cu2O nanocubes as precursors. The synthesis processes involve the repeated anion exchange reaction with Na2S and the controllable etching using hydrochloric acid. The whole synthesis processes are well revealed and the obtained double-shell CuS is tested as pseudocapacitive electrode material for supercapacitors. As expected, the CuS double-shell hollow nanocages deliver high specific capacitance, good rate performance and excellent cycling stability due to their unique nano-architecture. The present work contributes greatly to the exploration of hollow metal sulfides with complex architecture and non-spherical shape, as well as their promising application in high-performance electrochemical supercapacitors.

  1. Hexagonal CeO2 nanostructures: an efficient electrode material for supercapacitors.

    Science.gov (United States)

    Maheswari, Nallappan; Muralidharan, Gopalan

    2016-09-28

    Cerium oxide (CeO2) has emerged as a new and promising pseudocapacitive material due to its prominent valance states and extensive applications in various fields. In the present study, hexagonal CeO2 nanostructures have been prepared via the hydrothermal method employing cationic surfactant cetyl trimethyl ammonium bromide (CTAB). CTAB ensures a slow rate of hydrolysis to form small sized CeO2 nanostructures. The role of calcination temperature on the morphological, structural, electrochemical properties and cyclic stability has been assessed for supercapacitor applications. The mesoscopic hexagonal architecture endows the CeO2 with not only a higher specific capacity, but also with an excellent rate capability and cyclability. When the charge/discharge current density is increased from 2 to 10 A g(-1) the reversible charge capacity decreased from 927 F g(-1) to 475 F g(-1) while 100% capacity retention at a high current density of 20 A g(-1) even after 1500 cycles could be achieved. Furthermore, the asymmetric supercapacitor based on CeO2 exhibited a significantly higher energy density of 45.6 W h kg(-1) at a power density of 187.5 W kg(-1) with good cyclic stability. The electrochemical richness of the CeO2 nanostructure makes it a suitable electrode material for supercapacitor applications.

  2. An Approach to Preparing Ni-P with Different Phases for Use as Supercapacitor Electrode Materials.

    Science.gov (United States)

    Wang, Dan; Kong, Ling-Bin; Liu, Mao-Cheng; Luo, Yong-Chun; Kang, Long

    2015-12-01

    Herein, we describe a simple two-step approach to prepare nickel phosphide with different phases, such as Ni2 P and Ni5 P4 , to explain the influence of material microstructure and electrical conductivity on electrochemical performance. In this approach, we first prepared a Ni-P precursor through a ball milling process, then controlled the synthesis of either Ni2 P or Ni5 P4 by the annealing method. The as-prepared Ni2 P and Ni5 P4 are investigated as supercapacitor electrode materials for potential energy storage applications. The Ni2 P exhibits a high specific capacitance of 843.25 F g(-1) , whereas the specific capacitance of Ni5 P4 is 801.5 F g(-1) . Ni2 P possesses better cycle stability and rate capability than Ni5 P4 . In addition, the Fe2 O3 //Ni2 P supercapacitor displays a high energy density of 35.5 Wh kg(-1) at a power density of 400 W kg(-1) and long cycle stability with a specific capacitance retention rate of 96 % after 1000 cycles, whereas the Fe2 O3 //Ni5 P4 supercapacitor exhibits a high energy density of 29.8 Wh kg(-1) at a power density of 400 W kg(-1) and a specific capacitance retention rate of 86 % after 1000 cycles.

  3. The Production and Characterization of Ceramic Carbon Electrode Materials for CuCl-HCl Electrolysis

    Science.gov (United States)

    Edge, Patrick

    Current H2 gas supplies are primarily produced through steam methane reforming and other fossil fuel based processes. This lack of viable large scale and environmentally friendly H2 gas production has hindered the wide spread adoption of H2 fuel cells. A potential solution to this problem is the Cu-Cl hybrid thermochemical cycle. The cycle captures waste heat to drive two thermochemical steps creating CuCl as well as O2 gas and HCl from CuCl2 and water. The CuCl is oxidized in HCl to produce H2 gas and regenerate CuCl2, this process occurs at potentials well below those required for water electrolysis. The electrolysis process occurs in a traditional PEM fuel-cell. In the aqueous anolyte media Cu(I) will form anionic complexes such as CuCl 2 - or CuCl32-. The slow transport of these species to the anode surface limits the overall electrolysis process. To improve this transport process we have produced ceramic carbon electrode (CCE) materials through a sol-gel method incorporating a selection of amine containing silanes with increasing numbers of primary and secondary amines. When protonated these amines allow for improved transport of anionic copper complexes. The electrochemical and physical characterization of these CCE materials in a half and full-cell electrolysis environment will be presented. Electrochemical analysis was performed using cell polarization, cyclic voltammetry, and electrochemical impedance spectroscopy.

  4. CuSbS2 as a negative electrode material for sodium ion batteries

    Science.gov (United States)

    Marino, C.; Block, T.; Pöttgen, R.; Villevieille, C.

    2017-02-01

    CuSbS2 was tested as a negative electrode material for sodium-ion batteries. The material synthesized by ball milling offers a specific charge of 730 mAh g-1, close to the theoretical value (751 mAh g-1), over a few cycles. The reaction mechanism was investigated by means of operando X-ray diffraction, 121Sb Mössbauer spectroscopy, and Cu K-edge X-ray absorption spectroscopy. These studies reveal a sodiation mechanism that involves an original conversion reaction in two steps, through the formation of a ternary phase, CuSb(1-x)S(2-y), as well as a NaxS alloy and Sb, followed by an alloying reaction involving the previously formed Sb. The desodiation process ends with the reformation of the ternary phase, CuSb(1-x‧)S(2-y‧), deficient in Sb and S; this phase is responsible for the good reversibility observed upon cycling.

  5. Natively textured ZnO grown by PECVD as front electrode material for amorphous silicon pin solar cells

    NARCIS (Netherlands)

    Löffler, J.; Schropp, R.E.I.; Groenen, Ft.; Van De Sanden, M.C.M.; Linden, J.L.

    2000-01-01

    Natively textured ZnO layers for the application as front electrode material in amorphous silicon pin solar cells have been deposited by Expanding Thermal Plasma Chemical Vapor Deposition. Films deposited in the temperature regime from 150 to 350°C at a rate between 0.65 and 0.75 nm/s have been char

  6. Polyaniline silver nanoparticle coffee waste extracted porous graphene oxide nanocomposite structures as novel electrode material for rechargeable batteries

    Science.gov (United States)

    Sundriyal, Poonam; Bhattacharya, Shantanu

    2017-03-01

    The exploration of new and advanced electrode materials are required in electronic and electrical devices for power storage applications. Also, there has been a continuous endeavour to formulate strategies for extraction of high performance electrode materials from naturally obtained waste products. In this work, we have developed an in situ hybrid nanocomposite from coffee waste extracted porous graphene oxide (CEPG), polyaniline (PANI) and silver nanoparticles (Ag) and have found this novel composite to serve as an efficient electrode material for batteries. The successful interaction among the three phases of the nano-composite i.e. CEPG-PANI-Ag have been thoroughly understood through RAMAN, Fourier transform infrared and x-ray diffraction spectroscopy, morphological studies through field emission scanning electron microscope and transmission electron microscope. Thermo-gravimetric analysis of the nano-composite demonstrates higher thermal stability up-to a temperature of 495 °C. Further BET studies through nitrogen adsorption-desorption isotherms confirm the presence of micro/meso and macro-pores in the nanocomposite sample. The cyclic-voltammetry (CV) analysis performed on CEPG-PANI-Ag nanocomposite exhibits a purely faradic behaviour using nickel foam as a current collector thus suggests the prepared nanocomposite as a battery electrode material. The nanocomposite reports a maximum specific capacity of 1428 C g-1 and excellent cyclic stability up-to 5000 cycles.

  7. Metal hydride-based materials towards high performance negative electrodes for all-solid-state lithium-ion batteries.

    Science.gov (United States)

    Zeng, Liang; Kawahito, Koji; Ikeda, Suguru; Ichikawa, Takayuki; Miyaoka, Hiroki; Kojima, Yoshitsugu

    2015-06-18

    Electrode performances of MgH2-LiBH4 composite materials for lithium-ion batteries have been studied using LiBH4 as the solid-state electrolyte, which shows a high reversible capacity of 1650 mA h g(-1) with an extremely low polarization of 0.05 V, durable cyclability and robust rate capability.

  8. Stacked Cu1.8S nanoplatelets as Counter Electrode for Quantum Dot-Sensitized Solar Cell

    Energy Technology Data Exchange (ETDEWEB)

    Savariraj, Dennyson A.; Rajendrakumar, G.; Selvam, Samayanan; Karthick, S. N.; Balamuralitharan, B.; Kim, Hee-Je; Viswanathan, Kodakkal K.; Vijayakumar, M.; Prabakar, Kandasamy

    2015-11-09

    It is found that electrocatalytic activity of Cu2-xS thin films used in quantum dots sensitized solar cells (QDSSC) as countner electrode (CE) for the reduction of polysulfide electrolyte depends on the the surface active sulfur species and defficiency of Cu. The preferential bonding between Cu2+ and S2- leading to the selective formation of Cu1.8S stacked platelets like morphology is determined by Cetyl Trimethyl Ammonium Bromide surfactant with temperature and crab like Cu-S coordination bond formed dictates the surface area to volume ratio of the Cu1.8S thin films and the electrocatalytic activity. The Cu deficiency enhances the conductivity of the Cu1.8S thin films and exhibits near- infrared localized surface plasmon resonanc due to free carrier intraband absorption and UV-VIS absorption spectra shows excitonic effect due to quantum size effect. When these Cu1.8S thin films were employed as CE in QDSSC, robust photoconversion efficiency of 5.2 % is yielded by the film deposited at 60°C by a sinlge step chemical bath deposition method.

  9. Effect of surface nanomorphology and interfacial galvanic coupling of PEDOT-titanium counter electrodes on the stability of dye-sensitized solar cell.

    Science.gov (United States)

    Madhavan, Asha Anish; Kalluri, Sujith; Paravannoor, Anjali; Nagarajan, Sivakumar; Subramanian, Kavasseri R V; Nair, Shantikumar; Balakrishnan, Avinash

    2012-08-01

    The present study demonstrates a novel approach by which titanium foils coated with electropolymerized poly(3,4-ethylenedioxythiophene) (PEDOT) in combination with sputtered platinum can be processed into a high-surface area cathodes for dye-sensitized solar cells (DSSCs). A detailed study has been performed to elucidate how surface nanomorphology and I(-)/I(3-) redox reaction behaviors underlying these photocathodes impact the DSSC performances. From the analysis of the relevant electrochemical parameters, an intrinsic correlation between the photovoltaic performances and the cathode surface area has been deduced for such a system and explained on the basis of relative contributions of the galvanic coupling properties of the nanomorphology PEDOT film and platinum. Depending on the type of photocathodes incorporated, it was observed that these PEDOT coated cathodes can exhibit higher stability over a given time range and photo-conversion efficiencies 12-40%, higher than that achievable in absence of the intermediate PEDOT coatings. It has been shown that DSSCs based on such metal-polymer hybrid photo-cathodes allow significant room for improvement in the catalytic performance at the electrode/electrolyte interface.

  10. Improvement Performance of Dye-sensitized Solar Cells with Pt/Ti Counter Electrode Prepared by Electrodeposition-displacement%电沉积-置换法制备Pt/Ti对电极及其对染料敏化太阳能电池性能的提升

    Institute of Scientific and Technical Information of China (English)

    王耀琼; 冉秀芝; 高焕方; 李莉; 魏子栋

    2014-01-01

    A Pt/Ti counter electrode of dye-sensitized solar cell( DSSC) was prepared by displacing electro-deposited Cu on a Ti sheet in H2 PtCl6 solution. Morphological characterization of the Pt/Ti electrode shows that the dispersion and size of Pt particles on Ti substrate is significantly improved in contrast to that of the Pt/FTO electrode prepared by pyrolysing Pt salt on a fluorine-doped oxide( FTO) glass substrate. The photo-current density-voltage( J-V) curves show that the overall energy conversion efficiency of DSSC with the Pt/Ti counter electrode increases by 20. 8% relative to that with the Pt/FTO counter electrode. The results also re-veal that the improved performance of the DSSC with the Pt/Ti counter electrode is assigned to the higher elec-trochemical surface area of the Pt/Ti counter electrode than the Pt/FTO, the lower electric resistance and the better reflecting ability of the Ti substrate than the FTO substrate.%采用电沉积-置换法在Ti片上制备了染料敏化太阳能电池( DSSC)的对电极Pt/Ti.形貌表征结果显示,与传统热解法制备的Pt/FTO对电极相比, Pt/Ti对电极Ti基底上Pt催化颗粒的粒径和分散性得到显著改善.光电流-光电压特性曲线测试结果表明,以Pt/Ti为对电极的DSSC与以Pt/FTO为对电极的DSSC相比,光电转化效率提高了20.8%.由于Pt颗粒分散性和粒径的改善所引起的Pt催化性能的提高、Pt/Ti对电极更低的电阻以及Ti基底更好的反光性能是提升DSSC性能的原因.

  11. Poly(3,3-dibenzyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine/Platinum Composite Films as Potential Counter Electrodes for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Jung-Chuan Chou

    2017-07-01

    Full Text Available In this study, poly(3,3-dibenzyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine/platinum composite films (PProDOT-Bz2/Pt were used as counter electrodes (CEs in dye-sensitized solar cells (DSSCs. The composite films were prepared on fluorine-doped tin oxide (FTO glass by radio frequency (RF sputtering to deposit platinum (Pt for 30 s. Afterwards, PProDOT-Bz2 was deposited on the Pt–FTO glass via electrochemical polymerization. The electron transfer process of DSSCs was investigated using electrochemical impedance spectroscopy (EIS and cyclic voltammetry (CV. The DSSCs with 0.05 C/cm2 PProDOT-Bz2-Pt composite films showed an open circuit voltage (Voc of 0.70 V, a short-circuit current density (Jsc of 7.27 mA/cm2, and a fill factor (F.F. of 68.74%. This corresponded to a photovoltaic conversion efficiency (η of 3.50% under a light intensity of 100 mW/cm2.

  12. Development of Novel Electrode Materials for the Electrocatalysis of Oxygen-Transfer and Hydrogen-Transfer Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Brett Kimball [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    Throughout this thesis, the fundamental aspects involved in the electrocatalysis of anodic O-transfer reactions and cathodic H-transfer reactions have been studied. The investigation into anodic O-transfer reactions at undoped and Fe(III)[doped MnO2 films] revealed that MnO2 film electrodes prepared by a cycling voltammetry deposition show improved response for DMSO oxidation at the film electrodes vs. the Au substrate. Doping of the MnO2 films with Fe(III) further enhanced electrode activity. Reasons for this increase are believed to involve the adsorption of DMSO by the Fe(III) sites. The investigation into anodic O-transfer reactions at undoped and Fe(III)-doped RuO2 films showed that the Fe(III)-doped RuO2-film electrodes are applicable for anodic detection of sulfur compounds. The Fe(III) sites in the Fe-RuO2 films are speculated to act as adsorption sites for the sulfur species while the Ru(IV) sites function for anodic discharge of H2O to generate the adsorbed OH species. The investigation into cathodic H-transfer reactions, specifically nitrate reduction, at various pure metals and their alloys demonstrated that the incorporation of metals into alloy materials can create a material that exhibits bifunctional properties for the various steps involved in the overall nitrate reduction reaction. The Sb10Sn20Ti70, Cu63Ni37 and Cu25Ni75 alloy electrodes exhibited improved activity for nitrate reduction as compared to their pure component metals. The Cu63Ni37 alloy displayed the highest activity for nitrate reduction. The final investigation was a detailed study of the electrocatalytic activity of cathodic H-transfer reactions (nitrate reduction) at various compositions of Cu-Ni alloy electrodes. Voltammetric response for NO3- at the Cu-Ni alloy electrode is superior to

  13. MnO2/PVP/MWCNT hybrid nano composites as electrode materials for high performance supercapacitor

    Science.gov (United States)

    Jaggi, Neena; Sharma, Deepa; Sharma, Priya

    2016-10-01

    In this work, we developed supercapacitors with electrodes of manganese oxide (MnO2) and its nanocomposites with multiwalled carbon nanotubes (MWCNT) and polyvinylpyrrolidone (PVP) and studied the effect of the electrode material on various performance parameters of the supercapacitor. Cyclic voltammetry (CV) curves, galvanostatic charge/discharge measurement curves, XRD (x-ray diffraction), I-V characteristics and electrochemical impedance spectroscopy were employed for the characterization and analysis. CV curves were used to verify the supercapacitor behavior and the specific capacitance of the capacitors composed of the nanocomposite electrodes was calculated. I-V characteristics of MnO2 and MnO2/PVP/MWCNT were plotted and compared and conductivity measurements were also performed. Dielectric properties and equivalent series resistance were investigated using electrochemical impedance spectroscopy.

  14. Hybrid Multi-Walled Carbon Nanotube TiO2 Electrode Material for Next Generation Energy Storage Devices

    CERN Document Server

    Marler, Sydney

    2016-01-01

    Current supercapacitors present several distinct limitations that severely inhibit the efficiency, power, and electrical capacitance of energy storage devices. Supercapacitors present an exciting prospect that has countless applications in renewable energy storage and modern day electronic devices. In recent years the exciting development of carbon nanotubes (CNTs) has presented an advantage in electrode development. CNTs, however beneficial for their increased electrode surface area, have severe limitations regarding conductivity and electrode density. Creating a nanocomposite hybrid out of a transition metal-oxide and carbon nanotube array would help the current limitations of the modern supercapacitor. TiO2 was chosen for its common occurrence in everyday materials and promising capacitance levels. A multi-walled carbon nanotube array was grown on a SiO2 precursor via CCVD. The transition metal oxide was then deposited via RF Sputtering methods to a MWCNT array. Recharge tests and characterization were con...

  15. Iron titanium phosphates as high-specific-capacity electrode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Essehli, R., E-mail: essehli.rachid@yahoo.fr [Laboratory of Mineral Solid and Analytical Chemistry (LMSAC), Department of Chemistry, Faculty of Sciences, University Mohamed I, PO. Box 717, 60000 Oujda (Morocco); ESECO SYSTEMS 270 rue Thomas Edison, Atelier Relais No 6, 34400 Lunel (France); El Bali, B. [Laboratory of Mineral Solid and Analytical Chemistry (LMSAC), Department of Chemistry, Faculty of Sciences, University Mohamed I, PO. Box 717, 60000 Oujda (Morocco); Faik, A. [CIC energigune, Parque Tecnológico de Álava, Albert Einstein 48, 01510 Miñano, Álava (Spain); Naji, M. [CNRS, UPR3079 CEMHTI, 1D avenue de la Recherche Scientifique, 45071 Orléans cedex 2 (France); Benmokhtar, S. [LCPGM, Laboratoire de Chimie-Physique Générale des Matériaux, Département de Chimie, Université Hassan II-Mohammedia, Faculté des Sciences Ben M’Sik, Casablanca (Morocco); Zhong, Y.R.; Su, L.W.; Zhou, Z. [Institute of New Energy Material Chemistry, Synergetic Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071 (China); Kim, J.; Kang, K. [Department of Materials Science and Engineering, Seoul National University, Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Dusek, M. [Institute of Physics of the ASCR, v.v.i., Na Slovance 2, 182 21 Praha 8 (Czech Republic)

    2014-02-05

    Highlights: • Iron Titanium Phosphates as High-Specific-Capacity. • Electrode Materials for Lithium ion Batteries. • During the following cycles, good reversible capacity retention and better cyclabilit. • Ex-situ XRD analysis during the first discharge shows an amorphization of this anode material. -- Abstract: Two iron titanium phosphates, Fe{sub 0.5}TiOPO{sub 4} and Fe{sub 0.5}Ti{sub 2}(PO{sub 4}){sub 3}, were prepared, and their crystal structures and electrochemical performances were compared. The electrochemical measurements of Fe{sub 0.5}TiOPO{sub 4} as an anode of a lithium ion cell showed that upon the first discharge down to 0.5 V, the cell delivered a capacity of 560 mA h/g, corresponding to the insertion of 5 Li’s per formula unit Fe{sub 0.5}TiOPO{sub 4}. Ex-situ XRD reveals a gradual evolution of the structure during cycling of the material, with lower crystallinity after the first discharge cycle. By correlating the electrochemical performances with the structural studies, new insights are achieved into the electrochemical behaviour of the Fe{sub 0.5}TiOPO{sub 4} anode material, suggesting a combination of intercalation and conversion reactions. The Nasicon-type Fe{sub 0.5}Ti{sub 2}(PO{sub 4}){sub 3} consists of a three-dimensional network made of corners and edges sharing [TiO{sub 6}] and [FeO{sub 6}] octahedra and [PO{sub 4}] tetrahedra leading to the formation of trimmers [FeTi{sub 2}O{sub 12}]. The first discharge of lithium ion cells based on Fe{sub 0.5}Ti{sub 2}(PO{sub 4}){sub 3} materials showed electrochemical activity of Ti{sup 4+}/Ti{sup 3+} and Fe{sup 2+}/Fe{sup 0} couples in the 2.5–1 V region. Below this voltage, the discharge profiles are typical of phosphate systems where Li{sub 3}PO{sub 4} is a product of the electrochemical reaction with lithium; moreover, the electrolyte solvent is reduced. An initial capacities as high as 1100 mA h g{sup −1} can be obtained at deep discharge. However, there is an irreversible capacity

  16. Experimental study of fission counter design optimization with a simplified analytical model of performance

    Energy Technology Data Exchange (ETDEWEB)

    Valentine, K.H.; De Lorenzo, J.T.; Clay, W.T.; Pare, V.K.; Guerrant, G.C.; Burns, R.S.

    1979-12-01

    Trends inferred from this study of fission counter design confirm previously known relationships between design variables and counter performance. Most important is the proved existence of an optimum electrode spacing for a specific design that increases with electrode area and decreases with gamma dose rate. The PD product also has an optimum value, with low values being limited by the presence of electronic noise and high values by enhanced gamma pileup. Conventional 50-..cap omega.. signal cables do not always provide the best performance, particularly for large-area counters that have high interelectrode capacitances and operate in high gamma background. Values as low as 16.7 ..cap omega.. yield an improvement of as much as 20%. The performance of a counter closely follows the E/P versus drift velocity characteristic of its gas mixture, and is superior for fill gases having higher electron drift velocities. The optimum filter time constant of the counting channel depends on the gamma background dose rate. At low gamma levels, when electronic noise dominates, longer filter time constants give better signal-to-noise ratios. Counters with shorter collection times more effectively suppress the gamma pileup at high dose rates, and filters with higher break-frequencies process the faster pulses more effectively. Another conclusion from this study is that the usable neutron sensitivity per gram of neutron-sensitive material is a monotonically decreasing function of electrode area. These sensitivity losses can be minimized for high-sensitivity fission counters by use of neutron-sensitive material with low intrinsic alpha activity (such as electromagnetically enriched uranium), as well as by careful specification of the major design variables.

  17. Polyaniline nanofiber/large mesoporous carbon composites as electrode materials for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Huan; Xu, Bin; Jia, Mengqiu, E-mail: jiamq@mail.buct.edu.cn; Zhang, Mei; Cao, Bin; Zhao, Xiaonan; Wang, Yu

    2015-03-30

    Highlights: • The composites of polyaniline nanofiber and large mesoporous carbon were prepared for supercapacitors. • The large mesoporous carbons were simply prepared by nano-CaCO{sub 3} template method. • The composites exhibit high capacitance and good rate capability and cycle stability. - Abstract: A composite of polyaniline nanofiber/large mesoporous carbon (PANI-F/LMC) hybrid was prepared by an in situ chemical oxidative polymerization of aniline monomer with nano-CaCO{sub 3} templated LMC as host matrix for supercapacitors. The morphology, composition and electronic structure of the composites (PANI-F/LMC) together with pure PANI nanofibers and the LMC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is found that the PANI nanofibers were incorporated into the large mesochannels of LMC with interpenetrating framework formed. Such unique structure endows the PANI-F/LMC composite with a high capacitance of 473 F g{sup −1} at a current load of 0.1 A g{sup −1} with good rate performance and cycling stability, suggesting its potential application in the electrode material for supercapacitors.

  18. Polyaniline integrated carbon nanohorn: A superior electrode materials for advanced energy storage

    Directory of Open Access Journals (Sweden)

    S. Maiti

    2014-12-01

    Full Text Available Fiber-like polyaniline (PANI/carbon nanohorn (CNH composites (PACN composites were prepared as electrode materials for supercapacitor by simple method that involves in-situ polymerization of aniline in the presence of CNH in acidic (HCl medium with noteworthy electrochemical performances. Thus, the prepared PACN composites show high specific capacitance value of ≈ 834 F/g at 5 mV/s scan rate compared to ≈ 231 F/g for pure PANI and CNH (≈ 145 F/g at same scan rate of 5 mV/s. CNHs are homogeneously dispersed throughout the matrix and coated successfully. Thus, it provides more active sites for nucleation and electron transfer path. In addition, the composites show high electrical conductivity in the order of ≈ 6.7•10–2 S•cm–1 which indicates the formation of continuous interconnected conducting network path in the PACN composites. Morphological study of the PACN composites was carried out by high resolution transmission electron microscopy (HRTEM and field emission scanning electron microscopy (FESEM.

  19. Incorporating conjugated carbonyl compounds into carbon nanomaterials as electrode materials for electrochemical energy storage.

    Science.gov (United States)

    Yang, Guanhui; Zhang, Yu; Huang, Yanshan; Shakir, Muhammad Imran; Xu, Yuxi

    2016-11-23

    The increasing demand for energy and growing concerns for environmental issues are promoting the development of organic electrode materials. Among these, conjugated carbonyl compounds (CCCs) represent one of the most attractive and promising candidates for sustainable and eco-benign energy storage devices in the coming future. However, most of the current compounds suffer from dissolution in organic electrolytes and low electronic conductivity, which result in severe capacity decay and poor rate performance. Recently, researchers have achieved considerable progress by introducing electroactive carbonyl compounds into carbon nanomaterials. This perspective provides an overview of the up-to-date development of these nanocomposites in metal ion batteries (lithium-ion batteries or sodium-ion batteries) and supercapacitors (SCs), including the synthesis, performance improvement and applications. We mainly focus on carbon nanotubes (CNTs), graphene and mesoporous carbon (MC) as carbon nanomaterials because of their high specific surface area, good conductivity, electrochemical stability and favourable interaction with conjugated carbonyl compounds. This strategy opens up new possibilities to realize cost-effective, sustainable and versatile energy storage devices.

  20. Solid Liquid Interdiffusion Bonding of Zn4Sb3 Thermoelectric Material with Cu Electrode

    Science.gov (United States)

    Lin, Y. C.; Lee, K. T.; Hwang, J. D.; Chu, H. S.; Hsu, C. C.; Chen, S. C.; Chuang, T. H.

    2016-10-01

    The ZnSb intermetallic compound may have thermoelectric applications because it is low in cost and environmentally friendly. In this study, a Zn4Sb3 thermoelectric element coated with a Ni barrier layer and a Ag reaction layer was bonded with a Ag-coated Cu electrode using a Ag/Sn/Ag solid-liquid interdiffusion bonding process. The results indicated that a Ni5Zn21 intermetallic phase formed easily at the Zn4Sb3/Ni interface, leading to sound adhesion. In addition, Sn film was found to react completely with the Ag layer to form a Ag3Sn intermetallic layer having a melting point of 480°C. The resulting Zn4Sb3 thermoelectric module can be applied at the optimized operation temperature (400°C) of Zn4Sb3 material as a thermoelectric element. The bonding strengths ranged from 14.9 MPa to 25.0 MPa, and shear tests revealed that the Zn4Sb3/Cu-joints fractured through the interior of the thermoelectric elements.

  1. Sensitive determination of carbendazim in orange juice by electrode modified with hybrid material.

    Science.gov (United States)

    Razzino, Claudia A; Sgobbi, Lívia F; Canevari, Thiago C; Cancino, Juliana; Machado, Sergio A S

    2015-03-01

    This paper describes the application of a glassy carbon electrode modified with a thin film of mesoporous silica/multiwalled carbon nanotubes for voltammetric determination of the fungicide carbendazim (CBZ). The hybrid material, (SiO2/MWCNT), was obtained by a sol-gel process using HF as the catalyst. The amperometric response to CBZ was measured at +0.73 V vs. Ag/AgCl by square wave voltammetry at pH 8.0. SiO2/MWCNT/GCE responded to CBZ in the linear range from 0.2 to 4.0 μmol L(-1). The calculated detection limit was 0.056 μmol L(-1), obtained using statistical methods. The SiO2/MWCNT/GCE sensor presented as the main characteristics high sensitivity, low detection limit and robustness, allowing CBZ determination in untreated real samples. In addition, this strategy afforded remarkable selectivity for CBZ against ascorbic and citric acid which are the main compounds of the orange juice. The excellent sensitivity and selectivity yielded feasible application for CBZ detection in orange juice sample.

  2. Studies on supercapacitor electrode material from activated lignin-derived mesoporous carbon.

    Science.gov (United States)

    Saha, Dipendu; Li, Yunchao; Bi, Zhonghe; Chen, Jihua; Keum, Jong K; Hensley, Dale K; Grappe, Hippolyte A; Meyer, Harry M; Dai, Sheng; Paranthaman, M Parans; Naskar, A K

    2014-01-28

    We synthesized mesoporous carbon from pre-cross-linked lignin gel impregnated with a surfactant as the pore-forming agent and then activated the carbon through physical and chemical methods to obtain activated mesoporous carbon. The activated mesoporous carbons exhibited 1.5- to 6-fold increases in porosity with a maximum Brunauer-Emmett-Teller (BET) specific surface area of 1148 m(2)/g and a pore volume of 1.0 cm(3)/g. Both physical and chemical activation enhanced the mesoporosity along with significant microporosity. Plots of cyclic voltammetric data with the capacitor electrode made from these carbons showed an almost rectangular curve depicting the behavior of ideal double-layer capacitance. Although the pristine mesoporous carbon exhibited a range of surface-area-based capacitance similar to that of other known carbon-based supercapacitors, activation decreased the surface-area-based specific capacitance and enhanced the gravimetric specific capacitance of the mesoporous carbons. A vertical tail in the lower-frequency domain of the Nyquist plot provided additional evidence of good supercapacitor behavior for the activated mesoporous carbons. We have modeled the equivalent circuit of the Nyquist plot with the help of two constant phase elements (CPE). Our work demonstrated that biomass-derived mesoporous carbon materials continue to show potential for use in specific electrochemical applications.

  3. Studies on Supercapacitor Electrode Material from Activated Lignin-Derived Mesoporous Carbon

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Dipendu [ORNL; Li, Yunchao [ORNL; Bi, Zhonghe [ORNL; Chen, Jihua [ORNL; Keum, Jong Kahk [ORNL; Hensley, Dale K [ORNL; Grappe, Hippolyte A. [Oak Ridge Institute for Science and Education (ORISE); Meyer III, Harry M [ORNL; Dai, Sheng [ORNL; Paranthaman, Mariappan Parans [ORNL; Naskar, Amit K [ORNL

    2014-01-01

    We synthesized mesoporous carbon from pre-cross-linked lignin gel impregnated with a surfactant as the pore-forming agent, and then activated the carbon through physical and chemical methods to obtain activated mesoporous carbon. The activated mesoporous carbons exhibited 1.5- to 6-fold increases in porosity with a maximum BET specific surface area of 1148 m2/g and a pore volume of 1.0 cm3/g. Slow physical activation helped retain dominant mesoporosity; however, aggressive chemical activation caused some loss of the mesopore volume fraction. Plots of cyclic voltammetric data with the capacitor electrode made from these carbons showed an almost rectangular curve depicting the behavior of ideal double-layer capacitance. Although the pristine mesoporous carbon exhibited the same range of surface-area-based capacitance as that of other known carbon-based supercapacitors, activation decreased the surface-area-based specific capacitance and increased the gravimetric-specific capacitance of the mesoporous carbons. Surface activation lowered bulk density and electrical conductivity. Warburg impedance as a vertical tail in the lower frequency domain of Nyquist plots supported good supercapacitor behavior for the activated mesoporous carbons. Our work demonstrated that biomass-derived mesoporous carbon materials continue to show potential for use in specific electrochemical applications.

  4. Nanoparticle dispersion-strengthened coatings and electrode materials for electrospark deposition

    Energy Technology Data Exchange (ETDEWEB)

    Levashov, E.A. [Moscow State Institute of Steel and Alloys, Technological University, Leninsky pr., 4, Moscow 119049 (Russian Federation)]. E-mail: levashov@shs.misis.ru; Vakaev, P.V. [Moscow State Institute of Steel and Alloys, Technological University, Leninsky pr., 4, Moscow 119049 (Russian Federation); Zamulaeva, E.I. [Moscow State Institute of Steel and Alloys, Technological University, Leninsky pr., 4, Moscow 119049 (Russian Federation); Kudryashov, A.E. [Moscow State Institute of Steel and Alloys, Technological University, Leninsky pr., 4, Moscow 119049 (Russian Federation); Pogozhev, Yu.S. [Moscow State Institute of Steel and Alloys, Technological University, Leninsky pr., 4, Moscow 119049 (Russian Federation); Shtansky, D.V. [Moscow State Institute of Steel and Alloys, Technological University, Leninsky pr., 4, Moscow 119049 (Russian Federation); Voevodin, A.A. [Air Force Research Laboratory, 2941 Hobson Way, Wright Patterson AFB, OH 45433 (United States); Sanz, A. [SKF Engineering and Research Centre, P.O. Box 2350 Kelvinbaan 16, 3430 DT Nieuwegein, 3439 MT Nieuwegein (Netherlands)

    2006-11-23

    Advanced electrode compositions were developed using self-propagating high-temperature synthesis (SHS). Electrospark deposition (ESD) was applied to produce tribological coatings which were disperse-strengthened by incorporation of nanosized particles. Nanostructured electrodes of cemented carbides were produced using powder metallurgy technologies. They allow increasing the coatings density, thickness, hardness, Young's modulus and wear resistance. Positive effects of the nanostructure of electrodes on the deposition process and structure and properties of the coatings are discussed. In that case the tungsten carbide phases become predominant in the coatings. A mechanism of the dissolution reaction of WC with Ni at the contact surface of electrode was proposed. It was shown that the formation of the coating structure starts on the electrode and is accomplished on the substrate.

  5. Microstrip proportional counter development at MSFC

    Science.gov (United States)

    Fulton, M. A.; Kolodziejczak, J. J.; Ramsey, B. D.

    1992-01-01

    Microstrip detectors are an exciting new development in proportional counter design fabricated using integrated circuit-type photolithography techniques; they therefore offer very high spatial accuracy and uniformity. A development program is underway at NASA-Marshall to produce large-area microstrips for use in an X-ray detector balloon flight program and to investigate the general performance limits of these new devices. Microstrips tested so far have been fabricated both in-house using standard photolithographic techniques and by an outside contractor using electron beam technology. Various substrate materials have been tested along with different electrode configurations. The distributions of pickup on subdivided cathodes on both top and bottom surfaces of the microstrips are also being investigated for use as two-dimensional imaging detectors. Data from these tests in the development of a large-area device will be presented.

  6. Hybrid Materials Polypyrrole-heteropolytungstate Electrosynthesis of Electrodes for Secondary Batteries

    Directory of Open Access Journals (Sweden)

    Cheng, S. A.

    2000-06-01

    Full Text Available Polypyrroles doped with heterpolytungstate anion [PW12O40]3- was electrogenerated from acetonitrile solutions. It is found that the productivity of the consumed charge to produce the hybrids always keeps at high constant value of about 1.9 x 10-3 mg mC-1, whatever the studied conditions including different potentials, different concentrations of pyrrole, different concentrations of PW12O40 3- or different temperatures. The hybrid material coats the electrode as a compact, adherent, conducting and dark-blue film. The specific charges of the materials initially increase as the polymer weight increases keeping a constant value for greater weight than 0.15 mg cm-2. Consecutive charge-discharge promotes a fast initial loss of material by solubility, the specific charge of the insoluble part increases until 90 mA h g-1. Both evolution of the cyclic voltammograms and UV-vis spectroscopies indicate the presence of macroanion in solution after cycling.

    Los polipirroles dopados con anión heteropoliwolframato [PW12O40]3- (materiales híbridos han sido electrogenerados desde disoluciones de acetonitrilo. Se ha visto que la productividad de la carga consumida para producir los híbridos siempre se mantiene a valores constantes elevados alrededor de 1.9 x 10-3 mg mC-1, cualquiera que sea la condición estudiada de síntesis: diferentes potenciales, diferentes concentraciones de pirrol, diferentes concentraciones de PW12O40 3- o diferentes temperaturas. El material híbrido recubre el electrodo en forma de film azul marino, compacto, adherente y conductor. Las cargas específicas almacenadas en los materiales inicialmente aumentan a medida que el peso del polímero aumenta, manteniendo un valor constante a partir de pesos mayores que 0.15 mg cm-2. La voltamperometría cíclica y la espectroscopía UV-vis indican la presencia de un intercambio de iones entre el macroión del film y el ClO4 -1 de la solución durante los procesos de oxidaci

  7. Synthesis and Characterization of Nanostructured Manganese Dioxide Used as Positive Electrode Material for Electrochemical Capacitor with Lithium Hydroxide Electrolyte

    Institute of Scientific and Technical Information of China (English)

    YUAN,An-Bao; ZHOU,Min; WANG,Xiu-Ling; SUN,Zi-Hong; WANG,Yu-Qin

    2008-01-01

    A nanostructured manganese dioxide electrode material was prepared using a solid-reaction route starting with MnCl2·4H2O and NH4HCO3, and its electrochemical performance as a positive electrode for MnO2/activated carbon hybrid supercapacitor with 1 mol·L-1 LiOH electrolyte was reported. The material was proved to be a mixture of nanostructured γ-MnO2 and α-MnO2 containing some bound water in the structure, which was characterized by X-ray diffraction analysis, infrared spectrum analysis, and transmission electron microscope observation. Electrochemical properties of the MnO2 electrode and the MnO2/AC capacitor were investigated by cyclic voltammetry, ac impedance and galvanostatic charge/discharge methods. Experimental results showed that the MnO2 electrode exhibited faradaic pseudocapacitance behavior and higher specific capacitance in 1 mol·L-1 LiOH electrolyte. The MnO2/AC hybrid capacitor with 1 mol·L-1 LiOH electrolyte presented excellent rate charge/discharge ability and cyclic stability.

  8. Impedance spectroscopy study of a catechol-modified activated carbon electrode as active material in electrochemical capacitor

    Science.gov (United States)

    Cougnon, C.; Lebègue, E.; Pognon, G.

    2015-01-01

    Modified activated carbon (Norit S-50) electrodes with electrochemical double layer (EDL) capacitance and redox capacitance contributions to the electric charge storage were tested in 1 M H2SO4 to quantify the benefit and the limitation of the surface redox reactions on the electrochemical performances of the resulting pseudo-capacitive materials. The electrochemical performances of an electrochemically anodized carbon electrode and a catechol-modified carbon electrode, which make use both EDL capacitance of the porous structure of the carbon and redox capacitance, were compared to the performances obtained for the pristine carbon. Nitrogen gas adsorption measurements have been used for studying the impact of the grafting on the BET surface area, pore size distribution, pore volume and average pore diameter. The electrochemical behavior of carbon materials was studied by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The EIS data were discussed by using a complex capacitance model that allows defining the characteristic time constant, the global capacitance and the frequency at which the maximum charge stored is reached. The EIS measurements were achieved at different dc potential values where a redox activity occurs and the evolution of the capacitance and the capacitive relaxation time with the electrode potential are presented. Realistic galvanostatic charge/discharge measurements performed at different current rates corroborate the results obtained by impedance.

  9. Role of the Material Electrodes on Resistive Behaviour of Carbon Nanotube-Based Gas Sensors for H2S Detection

    Directory of Open Access Journals (Sweden)

    M. Lucci

    2012-01-01

    Full Text Available Miniaturized gas-sensing devices that use single-walled carbon nanotubes as active material have been fabricated using two different electrode materials, namely, Au/Cr and NbN. The resistive sensors have been assembled aligning by dielectrophoresis the nanotube bundles between 40 μm spaced Au/Cr or NbN multifinger electrodes. The sensing devices have been tested for detection of the H2S gas, in the concentration range 10–100 ppm, using N2 as carrier gas. No resistance changes were detected using sensor fabricated with NbN electrodes, whereas the response of the sensor fabricated with Au/Cr electrodes was characterized by an increase of the resistance upon gas exposure. The main performances of this sensor are a detection limit for H2S of 10 ppm and a recovery time of few minutes. The present study suggests that the mechanism involved in H2S gas detection is not a direct charge transfer between molecules and nanotubes. The hypothesis is that detection occurs through passivation of the Au surfaces by H2S molecules and modification of the contact resistance at the Au/nanotube interface.

  10. Amorphous Li-Al-Based Compounds: A Novel Approach for Designing High Performance Electrode Materials for Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Franziska Thoss

    2013-11-01

    Full Text Available A new amorphous compound with the initial atomic composition Al43Li43Y6Ni8 applied as electrode material for Li-ion batteries is investigated. Unlike other amorphous compounds so-far investigated as anode materials, it already contains Li as a base element in the uncycled state. The amorphous compound powder is prepared by high energy ball milling of a master alloy. It shows a strongly enhanced specific capacity in contrast to amorphous alloys without Li in the initial state. Therewith, by enabling a reversible (delithiation of metallic electrodes without the phase transition caused volume changes it offers the possibility of much increased specific capacities than conventional graphite anodes. According to the charge rate (C-rate, the specific capacity is reversible over 20 cycles at minimum in contrast to conventional crystalline intermetallic phases failing by volume changes. The delithiation process occurs quasi-continuously over a voltage range of nearly 4 V, while the lithiation is mainly observed between 0.1 V and 1.5 V. That way, the electrode is applicable for different potential needs. The electrode stays amorphous during cycling, thus avoiding volume changes. The cycling performance is further enhanced by a significant amount of Fe introduced as wear debris from the milling tools, which acts as a promoting element.

  11. Rapid synthesis of monodispersed highly porous spinel nickel cobaltite (NiCo2O4) electrode material for supercapacitors

    Science.gov (United States)

    Naveen, A. Nirmalesh; Selladurai, S.

    2015-06-01

    Monodispersed highly porous spinel nickel cobaltite electrode material was successfully synthesized in a short time using combustion technique. Single phase cubic nature of the spinel nickel cobaltite with average crystallite size of 24 nm was determined from X-ray diffraction study. Functional groups present in the compound were determined from FTIR study and it further confirms the spinel formation. FESEM images reveal the porous nature of the prepared material and uniform size distribution of the particles. Electrochemical evaluation was performed using Cyclic Voltammetry (CV) technique, Chronopotentiometry (CP) and Electrochemical Impedance Spectroscopy (EIS). Results reveal the typical pseudocapacitive behaviour of the material. Maximum capacitance of 754 F/g was calculated at the scan rate of 5 mV/s, high capacitance was due to the unique porous morphology of the electrode. Nyquist plot depicts the low resistance and good electrical conductivity of nickel cobaltite. It has been found that nickel cobaltite prepared by this typical method will be a potential electrode material for supercapcitor application.

  12. Enhanced photovoltaic performance and time varied controllable growth of a CuS nanoplatelet structured thin film and its application as an efficient counter electrode for quantum dot-sensitized solar cells via a cost-effective chemical bath deposition.

    Science.gov (United States)

    Thulasi-Varma, Chebrolu Venkata; Rao, S Srinivasa; Kumar, Challa Shesha Sai Pavan; Gopi, Chandu V V M; Durga, I Kanaka; Kim, Soo-Kyoung; Punnoose, Dinah; Kim, Hee-Je

    2015-11-28

    For the first time we report a simple synthetic strategy to prepare copper sulfide counter electrodes on fluorine-doped tin oxide (FTO) substrates using the inexpensive chemical bath deposition method in the presence of hydrochloric acid (HCl) at different deposition times. CuS nanoplatelet structures were uniformly grown on the FTO substrate with a good dispersion and optimized conditions. The growth process of the CuS nanoplatelets can be controlled by changing the deposition time in the presence of HCl. HCl acts as a complexing agent as well as improving S(2-) concentration against S atoms in this one-step preparation. The photovoltaic performance was significantly improved in terms of the power conversion efficiency (PCE), short-circuit density (J(sc)), open-circuit voltage (V(oc)), and the fill factor (FF). The optimized deposition time of CuS 60 min resulted in a higher PCE of 4.06%, J(sc) of 12.92 mA cm(-2), V(oc) of 0.60 V, and a FF of 0.52 compared to CuS 50 min, CuS 70 min, and a Pt CE. The superior performance of the 60 min sample is due to the greater electrocatalytic activity and low charge transfer resistance at the interface of the CE and the polysulfide electrolyte. The concentration of Cu/S also had an important role in the formation of the CuS nanoplatelet structures. The optical bandgaps for the CuS with different morphologies were measured to be in the range of 1.98-2.28 eV. This improved photovoltaic performance is mainly attributed to the greater number of active reaction sites created by the CuS layer on the FTO substrate, which results large specific surface, superior electrical conductivity, low charge transfer resistance, and faster electron transport in the presence of HCl. Cyclic voltammetry, electrochemical impedance spectroscopy and Tafel-polarization measurements were used to investigate the electrocatalytic activity of the CuS and Pt CEs. This synthetic procedure not only provides high electrocatalytic activity for QDSSCs but could

  13. Influence of La-dopant on the Material Characteristics and Supercapacitive Performance of MnO2 Electrodes

    Institute of Scientific and Technical Information of China (English)

    Lü Yanling; SHAO Guangjie; ZHAO Beilong; ZHANG Liuli

    2011-01-01

    Manganese dioxide was synthesized by electrodeposition method with Mn (CH3COO)2 · 4H2O as a raw material. La(NO3)3 · 6H2O was doped in electroyte during the preparing process to improve the performance of MnO2 electrodes. The micrographs, crystal structure and element content of electrodes were analyzed by SEM, XRD and atomic absorption spectroscopy, respectively. It is found that the La content ratio in the dioxide can be easily controlled by adjusting the composition of the plating solution. Appropriate amount of doped La can increase the surface area of Mn/La materials, resulting in the supercapacitive behavior enhancement. Electrochemical tests show that the specific capacitance is significantely increased from 198.72 F · g-1 to 276.60 F · g-1 by La-doping.

  14. Ultra-fast dry microwave preparation of SnSb used as negative electrode material for Li-ion batteries

    Science.gov (United States)

    Antitomaso, P.; Fraisse, B.; Sougrati, M. T.; Morato-Lallemand, F.; Biscaglia, S.; Aymé-Perrot, D.; Girard, P.; Monconduit, L.

    2016-09-01

    Tin antimonide alloy was obtained for the first time using a very simple dry microwave route. Up to 1 g of well crystallized SnSb can be easily prepared in 90 s under air in an open crucible. A full characterization by X-ray diffraction and 119Sn Mössbauer spectroscopy demonstrated the benefit of carbon as susceptor, which avoid any oxide contamination. The microwave-prepared SnSb was tested as negative electrode material in Li batteries. Interesting results in terms of capacity and rate capability were obtained with up to 700 mAh/g sustained after 50 cycles at variable current. These results pave the way for the introduction of microwave synthesis as realistic route for a rapid, low cost and up-scalable production of electrode material for Li batteries or other large scale application types.

  15. Hierarchically ordered mesoporous carbon/graphene composites as supercapacitor electrode materials.

    Science.gov (United States)

    Song, Yanjie; Li, Zhu; Guo, Kunkun; Shao, Ting

    2016-08-25

    Hierarchically ordered mesoporous carbon/graphene (OMC/G) composites have been fabricated by means of a solvent-evaporation-induced self-assembly (EISA) method. The structures of these composites are characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy and nitrogen adsorption-desorption at 77 K. These results indicate that OMC/G composites possess the hierarchically ordered hexagonal p6mm mesostructure with the lattice unit parameter and pore diameter close to 10 nm and 3 nm, respectively. The specific surface area of OMC/G composites after KOH activation is high up to 2109.2 m(2) g(-1), which is significantly greater than OMC after activation (1474.6 m(2) g(-1)). Subsequently, the resulting OMC/G composites as supercapacitor electrode materials exhibit an outstanding capacitance as high as 329.5 F g(-1) in 6 M KOH electrolyte at a current density of 0.5 A g(-1), which is much higher than both OMC (234.2 F g(-1)) and a sample made by mechanical mixing of OMC with graphene (217.7 F g(-1)). In addition, the obtained OMC/G composites display good cyclic stability, and the final capacitance retention is approximately 96% after 5000 cycles. These ordered mesopores in the OMC/G composites are beneficial to the accessibility and rapid diffusion of the electrolyte, while graphene in OMC/G composites can also facilitate the transport of electrons during the processes of charging and discharging owing to its high conductivity, thereby leading to an excellent energy storage performance. The method demonstrated in this work would open up a new route to design and develop graphene-based architectures for supercapacitor applications.

  16. Layer by Layer Ex-Situ Deposited Cobalt-Manganese Oxide as Composite Electrode Material for Electrochemical Capacitor.

    Directory of Open Access Journals (Sweden)

    Rusi

    Full Text Available The composite metal oxide electrode films were fabricated using ex situ electrodeposition method with further heating treatment at 300°C. The obtained composite metal oxide film had a spherical structure with mass loading from 0.13 to 0.21 mg cm(-2. The structure and elements of the composite was investigated using X-ray diffraction (XRD and energy dispersive X-ray (EDX. The electrochemical performance of different composite metal oxides was studied by cyclic voltammetry (CV and galvanostatic charge-discharge (CD. As an active electrode material for a supercapacitor, the Co-Mn composite electrode exhibits a specific capacitance of 285 Fg(-1 at current density of 1.85 Ag(-1 in 0.5 M Na2SO4 electrolyte. The best composite electrode, Co-Mn electrode was then further studied in various electrolytes (i.e., 0.5 M KOH and 0.5 M KOH/0.04 M K3Fe(CN 6 electrolytes. The pseudocapacitive nature of the material of Co-Mn lead to a high specific capacitance of 2.2 x 10(3 Fg(-1 and an energy density of 309 Whkg(-1 in a 0.5 M KOH/0.04 M K3Fe(CN 6 electrolyte at a current density of 10 Ag(-1. The specific capacitance retention obtained 67% of its initial value after 750 cycles. The results indicate that the ex situ deposited composite metal oxide nanoparticles have promising potential in future practical applications.

  17. 锂离子电池电极材料选择%Electrode Materials for Lithium Ion Battery

    Institute of Scientific and Technical Information of China (English)

    张临超; 陈春华

    2011-01-01

    It has been 20 years since lithium ion battery appeared as a commercial product. Different kinds of new electrode materials are urgently needed to meet the demands of the society. In this review, some knowledge about lithium ion battery is first given. Then we focus on several new positive/negative electrode materials reported up to date. When they were used as lithium ion battery electrode materials, how they are synthesized, the main improvement methods and their electrochemical performance will be presented. Finally, we give a short summary of the advantages/disadvantages of these new electrode materials. Furthermore, an outlook for the potential applications of lithium ion batteries in the future is proposed.%商用锂离子电池发展至今已有20年,为了满足不同方面的社会需求,人们迫切需要新型锂离子电池电极材料.本文首先简要介绍了锂离子电池的相关知识,随后对多种新型锂离子电池正负极材料的制备、改进方法及电化学性能做了详细介绍,最后对各种电极材料的优缺点进行了简要的总结.本文还对锂离子电池在未来的应用进行了展望,以期待锂离子电池更好地为人类服务.

  18. Hemi-ordered nanoporous carbon electrode material for highly selective determination of nitrite in physiological and environmental systems

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shenghai; Wu, Hongmin; Wu, Ying; Shi, Hongyan; Feng, Xun; Jiang, Shang; Chen, Jian; Song, Wenbo, E-mail: wbsong@jlu.edu.cn

    2014-08-01

    Hemi-ordered nanoporous carbon (HONC) was obtained from a mesoporous silica template through a nano-replication method using furfuryl alcohol as the carbon source. The structure and morphology of HONC were characterized and analyzed in detail by X-ray diffraction, N{sub 2}-sorption, Raman spectroscopy and transmission electron microscopy. HONC was then demonstrated as active electrode material for selective determination of nitrite in either physiological or environmental system. Well separated oxidation peaks of ascorbic acid, dopamine, uric acid and nitrite were observed in physiological system, and simultaneous discrimination of catechol, hydroquinone, resorcinol and nitrite in environmental system was also accomplished. Distinctly improved performances for selective determination of nitrite (such as significantly fast and sensitive current response with especially high selectivity) coexisted with ascorbic acid, dopamine and uric acid in the physiological system, as well as with catechol, hydroquinone and resorcinol in the environmental system were achieved at HONC electrode material. The excellent discriminating ability and high selectivity for NO{sub 2}{sup −} determination were ascribed to the good electronic conductivity, unique hemi-ordered porous structure, large surface area and large number of edge plane defect sites contained on the surface of nanopore walls of HONC. Results in this work demonstrated that HONC is one of the promising catalytic electrode materials for nitrite sensor fabrication. - Highlights: • Hemi-ordered nanoporous carbon as an active electrode material • Good discriminating ability towards NO{sub 2}{sup −} from physiological or environmental system • Highly selective determination of nitrite with fast and sensitive current response.

  19. Development of Novel Metal Hydride-Carbon Nanomaterial Based Nanocomposites as Anode Electrode Materials for Lithium Ion Battery

    Science.gov (United States)

    2014-06-30

    Final Progress Report (27-02-2012 To 26-02-2014) Project Title:- Development of novel metal hydride -carbon nanomaterial based nanocomposites as...anode electrode materials for Lithium ion battery Objectives:- The aim of this study is to develop metal hydride –carbon nanomaterial based...be as follows:- Milestone I • Synthesis of nanosized metal hydrides (NMH)-carbon nanotubes (CNT) hybridizing with G (NMH- CNT-G) nanocomposites

  20. GEIGER-MULLER TYPE COUNTER TUBE

    Science.gov (United States)

    Fowler, I.L.; Watt, L.A.K.

    1959-12-15

    A single counter tube capable of responding to a wide range of intensities is described. The counter tube comprises a tubular cathode and an anode extending centrally of the cathode. The spacing between the outer surface of the anode and the inner surface of the cathode is varied along the length of the tube to provide different counting volumes in adjacent portions of the tube. A large counting volume in one portion adjacent to a low-energy absorption window gives adequate sensitivity for measuring lowintensity radiation, while a smaller volume with close electrode spacing is provided in the counter to make possible measurement of intense garnma radiation fields.

  1. Evaluating biomass-derived hierarchically porous carbon as the positive electrode material for hybrid Na-ion capacitors

    Science.gov (United States)

    Chen, Jizhang; Zhou, Xiaoyan; Mei, Changtong; Xu, Junling; Zhou, Shuang; Wong, Ching-Ping

    2017-02-01

    As a promising renewable resource, biomass has several advantages such as wide availability, low cost, and versatility. In this study, we use peanut shell, wheat straw, rice straw, corn stalk, cotton stalk, and soybean stalk as the precursors to synthesize hierarchically porous carbon as the positive electrode material for hybrid Na-ion capacitors, aiming to establish a criterion of choosing suitable biomass precursors. The carbon derived from wood-like cotton stalk has abundant interconnected macropores, high surface area of 1994 m2 g-1, and large pore volume of 1.107 cm3 g-1, thanks to which it exhibits high reversible capacitance of 160.5 F g-1 at 0.2 A g-1 and great rate capability, along with excellent cyclability. The carbonaceous positive electrode material is combined with a Na2Ti2.97Nb0.03O7 negative electrode material to assemble a hybrid Na-ion capacitor, which delivers a high specific energy of 169.4 Wh kg-1 at 120.5 W kg-1, ranking among the best-performed hybrid ion capacitors.

  2. Preparation and photoelectrocatalytic performance of N-doped TiO2/NaY zeolite membrane composite electrode material.

    Science.gov (United States)

    Cheng, Zhi-Lin; Han, Shuai

    2016-01-01

    A novel composite electrode material based on a N-doped TiO2-loaded NaY zeolite membrane (N-doped TiO2/NaY zeolite membrane) for photoelectrocatalysis was presented. X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible (UV-vis) and X-ray photoelectron spectroscopy (XPS) characterization techniques were used to analyze the structure of the N-doped TiO2/NaY zeolite membrane. The XRD and SEM results verified that the N-doped TiO2 nanoparticles with the size of ca. 20 nm have been successfully loaded on the porous stainless steel-supported NaY zeolite membrane. The UV-vis result showed that the N-doped TiO2/NaY zeolite membrane exhibited a more obvious red-shift than that of N-TiO2 nanoparticles. The XPS characterization revealed that the doping of N element into TiO2 was successfully achieved. The photoelectrocatalysis performance of the N-doped TiO2/NaY zeolite membrane composite electrode material was evaluated by phenol removal and also the effects of reaction conditions on the catalytic performance were investigated. Owing to exhibiting an excellent catalytic activity and good recycling stability, the N-doped TiO2/NaY zeolite membrane composite electrode material was of promising application for photoelectrocatalysis in wastewater treatment.

  3. A Difference in Using Atomic Layer Deposition or Physical Vapour Deposition TiN as Electrode Material in Metal-Insulator-Metal and Metal-Insulator-Silicon Capacitors

    NARCIS (Netherlands)

    Groenland, A.W.; Wolters, R.A.M.; Kovalgin, A.Y.; Schmitz, J.

    2011-01-01

    In this work, metal-insulator-metal (MIM) and metal-insulator-silicon (MIS) capacitors are studied using titanium nitride (TiN) as the electrode material. The effect of structural defects on the electrical properties on MIS and MIM capacitors is studied for various electrode configurations. In the M

  4. Effects of electrode material and configuration on the characteristics of planar resistive switching devices

    KAUST Repository

    Peng, H.Y.

    2013-11-13

    We report that electrode engineering, particularly tailoring the metal work function, measurement configuration and geometric shape, has significant effects on the bipolar resistive switching (RS) in lateral memory devices based on self-doped SrTiO3 (STO) single crystals. Metals with different work functions (Ti and Pt) and their combinations are used to control the junction transport (either ohmic or Schottky-like). We find that the electric bias is effective in manipulating the concentration of oxygen vacancies at the metal/STO interface, influencing the RS characteristics. Furthermore, we show that the geometric shapes of electrodes (e.g., rectangular, circular, or triangular) affect the electric field distribution at the metal/oxide interface, thus plays an important role in RS. These systematic results suggest that electrode engineering should be deemed as a powerful approach toward controlling and improving the characteristics of RS memories. 2013 Author(s).

  5. A promising electrode material modified by Nb-doped TiO2 nanotubes for electrochemical degradation of AR 73.

    Science.gov (United States)

    Xu, Li; Liang, Gaorui; Yin, Ming

    2017-04-01

    A distinctive SnO2Sb electrode with highly ordered Nb doped TiO2 nanotubes sheet as a new substrate, obtained by NbTi alloy anodization, is prepared by pulse electrochemical deposition for the first time as electrocatalytic oxidation anode for wastewater treatment. The novel electrode has a larger surface area and smaller crystallite particles than conventional SnO2Sb electrodes as obtained from the analysis of scanning electron microscopy and X-ray diffraction. Compared with Ti/SnO2Sb and Ti/TiO2-NTs/SnO2Sb prepared by pulse electrochemical deposition, the electrode modified by NbTiO2-NTs has the higher oxygen evolution potential of 2.29 V (vs. Ag/AgCl), and the lower charge transfer resistance, which decreased by 65% and 79%. The service lifetime of NbTi/NbTiO2-NTs/SnO2Sb is 4.9 times longer than that of Ti/SnO2Sb and 1.9 times longer than that of Ti/TiO2-NTs/SnO2Sb. The new electrode is proved to have an excellent electrochemical oxidation and degradation ability using Acid Red 73 as a target organic pollutant. The AR 73 removal, chemical oxygen demand removal and kinetic rate constant are increased obviously due to the introduction of NbTiO2-NTs. Besides, the energy consumption reduces 37.2% and 31.4% in contrast with Ti/SnO2Sb and Ti/TiO2-NTs/SnO2Sb. Hence, the Ti/SnO2Sb modified by NbTiO2-NTs is a very promising anode material for the electrochemical treatment of dye wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Fabrication of a flexible and conductive lyocell fabric decorated with graphene nanosheets as a stable electrode material.

    Science.gov (United States)

    Mengal, Naveed; Sahito, Iftikhar Ali; Arbab, Alvira Ayoub; Sun, Kyung Chul; Qadir, Muhammad Bilal; Memon, Anam Ali; Jeong, Sung Hoon

    2016-11-01

    Textile electrodes are highly desirable for wearable electronics as they offer light-weight, flexibility, cost effectiveness and ease of fabrication. Here, we propose the use of lyocell fabric as a flexible textile electrode because of its inherently super hydrophilic characteristics and increased moisture uptake. A highly concentrated colloidal solution of graphene oxide nanosheets (GONs) was coated on to lyocell fabric and was then reduced in to graphene nanosheets (GNs) using facile chemical reduction method. The proposed textile electrode has a very high surface conductivity with a very low value of surface resistance of only 40Ωsq(-1), importantly without use of any binding or adhesive material in the processing step. Atomic force spectroscopy (AFM) and Transmission electron microscopy (TEM) were conducted to study the topographical properties and sheet exfoliation of prepared GONs. The surface morphology, structural characterization and thermal stability of the fabricated textile electrode were studied by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), X ray photon spectroscopy (XPS), Raman spectroscopy, Wide angle X ray diffraction spectroscopy (WAXD) and Thermogravimetric analysis (TGA) respectively. These results suggest that the GONs is effectively adhered on to the lyocell fabric and the conversion of GONs in to GNs by chemical reduction has no adverse effect on the crystalline structure of textile substrate. The prepared graphene coated conductive lyocell fabric was found stable in water and electrolyte solution and it maintained nearly same surface electrical conductivity at various bending angles. The electrical resistance results suggest that this lyocell based textile electrode (L-GNs) is a promising candidate for flexible and wearable electronics and energy harvesting devices.

  7. Synthesis of Polyaniline-Coated Ordered Mesoporous Carbon Composite Electrode Material for Supercapacitor and Its Enhanced Electrochemical Performance.

    Science.gov (United States)

    Li, Na; Xu, Jianxiong; Xu, Lijian; Du, Jingjing; Wang, Xianyou

    2015-07-01

    The polyaniline-coated ordered mesoporous carbon (PCOMC) material was prepared by chemical polymerization of aniline monomers on the ordered mesoporous carbon (OMC). The synthesized PCOMC materials were characterized by scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption isotherms and Fourier infrared spectroscopy. It was demonstrated that the polyaniline was successfully incorporated and well deposited on the external surface and inner pores of the OMC material. Furthermore, the electrochemical performance of the original OMC and PCOMC materials are compared by using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge tests. The results showed that the electrochemical performance of the OMC material was enhanced after the incorporation of polyaniline. The specific capacitance of PCOMC electrode (813.4 F/g) measured by cyclic voltammetry at the scan rate of 2 mV/s was much higher than that of the OMC electrode (200.9 F/g). The discharge specific capacitance of the PCOMC supercapacitor could be kept at 119.4 F/g when the current density was 5 A/g, indicating its good rate performance even at high charge/discharge current density. Moreover, the PCOMC supercapacitor exhibited long cycling stability with the capacitance retention remained 77% after 3500 cycles.

  8. Electrochemical and thermodynamic studies of the electrode materials for lithium ion batteries

    Science.gov (United States)

    Bang, Hyun Joo

    profiles observed during the charge and discharge processes are related to the Li insertion/extraction reaction in the spinel host structure for both materials. The reversible heat generation due to the lithium insertion/extraction reaction in the host electrode is estimated on the basis of the cell entropy change. The heat generation calculated from DeltaS and the open circuit potential results is consistent with the heat profile (exothermic/endothermic) generated during the charge/discharge process and with the magnitude of the heat generation from the experimental results obtained from the IMC at a slow charge/discharge rate. The irreversible heat generation dependence on the current rate is discussed at different discharge rates.

  9. Solution-based chemical synthesis of electrode materials for electrochemical power sources

    Science.gov (United States)

    Jeong, Yeon Uk

    The popularity of portable electronic devices and the desire for clean-air vehicles have created enormous interest in electrochemical power sources. Lithium-ion batteries offering higher energy density compared to other rechargeable battery systems are becoming the choice of a power source for portables. On the other hand, electrochemical supercapacitors offering higher power density compared to batteries are appealing for hybrid electric vehicles. However, both the lithium-ion and supercapacitor technologies are hampered by the high cost and toxicity of the currently used electrode materials. This dissertation explores alternate low cost materials for lithium-ion batteries and supercapacitors by employing novel solution-based chemical synthesis procedures. Manganese oxides are attractive alternates for lithium-ion cells as Mn is inexpensive and environmentally benign. Several NaxMnO 2+delta oxides crystallizing in different structures have been synthesized in this study by reducing sodium permanganate with sodium iodide in aqueous medium followed by firing the reduction product. While the hexagonal Na 0.7MnO2+delta (delta ≈ 0.3) transforms to a spinel-like phase during ion exchange with lithium salts, the layered and tunnel Na 0.5MnO2+delta are quite stable to ion-exchange reactions. The ion-exchanged layered and tunnel Na0.5-xLixMnO 2+delta exhibit initial capacities of, respectively, 225 and 170 mA/g. While it is difficult to maintain a high capacity with good cyclability with the tunnel structure, the layered material is found to exhibit good cyclability. Amorphous RuO2·xH2O has been shown in the literature to exhibit a high capacitance of 720 F/g in electrochemical redox capacitors. With an objective to lower the cost per F capacitance, (i) substitutions of low cost Cr and W for Ru, (ii) coating of RuO2·xH 2O on low cost oxides, and (iii) other low cost transition metal oxides and sulfides in various electrolytes have been pursued in this study. Ru1-xCrxO2

  10. The preparation and performance of calcium carbide-derived carbon/polyaniline composite electrode material for supercapacitors

    Science.gov (United States)

    Zheng, Liping; Wang, Ying; Wang, Xianyou; Li, Na; An, Hongfang; Chen, Huajie; Guo, Jia

    Calcium carbide (CaC 2)-derived carbon (CCDC)/polyaniline (PANI) composite materials are prepared by in situ chemical oxidation polymerization of an aniline solution containing well-dispersed CCDC. The structure and morphology of CCDC/PANI composite are characterized by Fourier infrared spectroscopy (FTIR), scanning electron microscope (SEM), transmission electron microscopy (TEM) and N 2 sorption isotherms. It has been found that PANI was uniformly deposited on the surface and the inner pores of CCDC. The supercapacitive behaviors of the CCDC/PANI composite materials are investigated with cyclic voltammetry (CV), galvanostatic charge/discharge and cycle life measurements. The results show that the CCDC/PANI composite electrodes have higher specific capacitances than the as grown CCDC electrodes and higher stability than the conducting polymers. The capacitance of CCDC/PANI composite electrode is as high as 713.4 F g -1 measured by cyclic voltammetry at 1 mV s -1. Besides, the capacitance retention of coin supercapacitor remained 80.1% after 1000 cycles.

  11. The preparation and performance of calcium carbide-derived carbon/polyaniline composite electrode material for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Liping; Wang, Xianyou; Li, Na; An, Hongfang; Chen, Huajie [School of Chemistry, Key Laboratory of Environmentally Friendly Chemistry and Applications of Minister of Education, Xiangtan University, Hunan 411105 (China); Wang, Ying; Guo, Jia [School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Hubei 430073 (China)

    2010-03-15

    Calcium carbide (CaC{sub 2})-derived carbon (CCDC)/polyaniline (PANI) composite materials are prepared by in situ chemical oxidation polymerization of an aniline solution containing well-dispersed CCDC. The structure and morphology of CCDC/PANI composite are characterized by Fourier infrared spectroscopy (FTIR), scanning electron microscope (SEM), transmission electron microscopy (TEM) and N{sub 2} sorption isotherms. It has been found that PANI was uniformly deposited on the surface and the inner pores of CCDC. The supercapacitive behaviors of the CCDC/PANI composite materials are investigated with cyclic voltammetry (CV), galvanostatic charge/discharge and cycle life measurements. The results show that the CCDC/PANI composite electrodes have higher specific capacitances than the as grown CCDC electrodes and higher stability than the conducting polymers. The capacitance of CCDC/PANI composite electrode is as high as 713.4 F g{sup -1} measured by cyclic voltammetry at 1 mV s{sup -1}. Besides, the capacitance retention of coin supercapacitor remained 80.1% after 1000 cycles. (author)

  12. Study of electrochemical properties of thin film materials obtained using plasma technologies for production of electrodes for pacemakers

    Science.gov (United States)

    Obrezkov, O. I.; Vinogradov, V. P.; Krauz, V. I.; Mozgrin, D. V.; Guseva, I. A.; Andreev, E. S.; Zverev, A. A.; Starostin, A. L.

    2016-09-01

    Studies of thin film materials (TFM) as coatings of tips of pacemaker electrodes implanted into the human heart have been performed. TFM coatings were deposited in vacuum by arc magnetron discharge plasma, by pulsed discharge of “Plasma Focus”, and by electron beam evaporation. Simulation of electric charge transfer to the heart in physiological blood- imitator solution and determination of electrochemical properties of the coatings were carried out. TFM of highly developed surface of contact with tissue was produced by argon plasma spraying of titanium powder with subsequent coating by titanium nitride in vacuum arc assisted by Ti ion implantation. The TFM coatings of pacemaker electrode have passed necessary clinical tests and were used in medical practice. They provide low voltage myocardium stimulation thresholds within the required operating time.

  13. Al-Doped ZnO Monolayer as a Promising Transparent Electrode Material: A First-Principles Study

    Directory of Open Access Journals (Sweden)

    Mingyang Wu

    2017-03-01

    Full Text Available Al-doped ZnO has attracted much attention as a transparent electrode. The graphene-like ZnO monolayer as a two-dimensional nanostructure material shows exceptional properties compared to bulk ZnO. Here, through first-principle calculations, we found that the transparency in the visible light region of Al-doped ZnO monolayer is significantly enhanced compared to the bulk counterpart. In particular, the 12.5 at% Al-doped ZnO monolayer exhibits the highest visible transmittance of above 99%. Further, the electrical conductivity of the ZnO monolayer is enhanced as a result of Al doping, which also occurred in the bulk system. Our results suggest that Al-doped ZnO monolayer is a promising transparent conducting electrode for nanoscale optoelectronic device applications.

  14. Ion selective electrode for determination of chloride ion in biological materials, food products, soils and waste water.

    Science.gov (United States)

    Sekerka, I; Lechner, J F

    1978-11-01

    The chloride ion selective electrode is used for a rapid, simple, and reliable determination of chloride ion in biological materials (blood serum, urine, fish, and plant tissues), food products (milk, beef extract, nutrient broth and orange, tomato, and grapefruit juices), soils, and waste water (industrial and municipal). The method consists of treating the samples with perchloric acid (pH 1) and potassium peroxydisulfate and determining the chloride content either by a calibration curve or by known addition or analyte addition, using the chloride ion selective electrode. Such sample treatment eliminates most of the interferences occurring in the samples, including iodide, complexing and reducing compounds, and macromolecular and surface-active species. The method is suitable for a wide range of chloride concentration, e.g., 5010 ppm Cl- in nutrient broth and 4890 ppm in beef extract and as low as 12 and 80 ppm in soil extracts.

  15. Nickel Sulfide/Graphene/Carbon Nanotube Composites as Electrode Material for the Supercapacitor Application in the Sea Flashing Signal System

    Institute of Scientific and Technical Information of China (English)

    Hailong Chen; Ji Li; Conglai Long; Tong Wei; Guoqing Ning; Jun Yan; Zhuangjun Fan

    2014-01-01

    This work presents NiS/graphene/carbon nanotube (NiS/GNS/CNT) composites as electrode material for the supercapacitor application in sea flashing signal systems. NiS nanosheets were closely anchored on the conductive GNS-CNT networks. As a result, the NiS/GNS/CNT electrode showed a high specific capacitance of 2 377 F·g-1 at 2 mV·s-1 and good cycling stability compared with the pure NiS (1 599 F·g-1 ). The enhanced electrochemical performances are attributed to the synergetic effect between the conductive carbon and the pseudo-capacitive NiS. The high performance supercapacitor may provide application in the sea flashing signal system.

  16. Nanostructured TiO2-coated activated carbon composite as an electrode material for asymmetric hybrid capacitors.

    Science.gov (United States)

    Kim, Sang-Ok; Lee, Joong Kee

    2012-02-01

    A nanostructured TiO2-coated activated carbon (TAC) composite was synthesized by a modified sol-gel reaction and employed it as a negative electrode active material for an asymmetric hybrid capacitor. The structural characterization showed that the TiO2 nano-layer was deposited on the surface of the activated carbon and the TAC composite has a highly mesoporous structure. The evaluation of electrochemical characteristics of the TAC electrode was carried out by galvanostatic charge/discharge cycling tests and electrochemical impedance spectroscopy. The obtained specific capacitance of the TAC composite was 42.87 F/g, which showed by 27.1% higher than that of the activated carbon (AC). The TAC composite also exhibited an excellent cycle performance and kept 95% of initial capacitance over 500 cycles.

  17. Al-Doped ZnO Monolayer as a Promising Transparent Electrode Material: A First-Principles Study.

    Science.gov (United States)

    Wu, Mingyang; Sun, Dan; Tan, Changlong; Tian, Xiaohua; Huang, Yuewu

    2017-03-29

    Al-doped ZnO has attracted much attention as a transparent electrode. The graphene-like ZnO monolayer as a two-dimensional nanostructure material shows exceptional properties compared to bulk ZnO. Here, through first-principle calculations, we found that the transparency in the visible light region of Al-doped ZnO monolayer is significantly enhanced compared to the bulk counterpart. In particular, the 12.5 at% Al-doped ZnO monolayer exhibits the highest visible transmittance of above 99%. Further, the electrical conductivity of the ZnO monolayer is enhanced as a result of Al doping, which also occurred in the bulk system. Our results suggest that Al-doped ZnO monolayer is a promising transparent conducting electrode for nanoscale optoelectronic device applications.

  18. Preparation and Electrochemistry of Hydrous Ruthenium Oxide/Active Carbon Electrode materials for Supercapacitor

    Institute of Scientific and Technical Information of China (English)

    Zhang; Jianrong

    2001-01-01

    In this paper, we reported a new method to directly prepare the amorphous hydrous ruthenium oxide/active carbon powders. The relationship between the specific capacitance and ruthenium content in powders was studied in detail. Physical properties of the powders such as crystallinity、 particle size, and electrochemical characteristics of electrodes were reported along with the capacitor performance.  ……

  19. Preparation and Electrochemistry of Hydrous Ruthenium Oxide/Active Carbon Electrode materials for Supercapacitor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ In this paper, we reported a new method to directly prepare the amorphous hydrous ruthenium oxide/active carbon powders. The relationship between the specific capacitance and ruthenium content in powders was studied in detail. Physical properties of the powders such as crystallinity、 particle size, and electrochemical characteristics of electrodes were reported along with the capacitor performance.

  20. Zn2+-Doped Polyaniline/Graphene Oxide as Electrode Material for Electrochemical Supercapacitors

    Science.gov (United States)

    Xu, Hui; Tang, Jing; Chen, Yong; Liu, Jian; Pu, Jinjuan; Li, Qi

    2017-10-01

    Electrodes based on Zn2+-doped polyaniline/graphene oxide (Zn2+/PANI/GO) were synthesized on stainless steel mesh substrates in H2SO4 solution via electrochemical codeposition. Different concentrations of graphene oxide (GO) were incorporated into the films to improve the electrochemical performance of the electrodes. Electrochemical properties of the films were tested by cyclic voltammetry, galvanostatic charge-discharge tests, and electrochemical impedance spectroscopy, in a three-electrode system. The maximum specific capacitance of the Zn2+/PANI/GO film with a GO concentration of 15 mg L-1 was found to be 1266 F g-1 at a scan rate of 3 mV s-1. This value was higher than that of a Zn2+ doped polyaniline (Zn2+/PANI) film (814 F g-1). The Zn2+/PANI/GO film also showed good cycling stability, retaining over 86% of its initial capacitance after 1000 cycles. These results indicate that the Zn2+/PANI/GO composites can be applied as high performance supercapacitor electrodes.

  1. Material-Process-Performance Relationships for Roll-to-Roll Coated PEM Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Mauger, Scott; Neyerlin, K.C.; Stickel, Jonathan; Ulsh, Michael; More, Karren; Wood, David

    2017-04-26

    Roll-to-roll (R2R) coating is the most economical and highest throughput method for producing fuel cell electrodes. R2R coating encompasses many different methodologies to create uniform films on a moving web substrate. Here we explore two coating methods, gravure and slot die, to understand the impacts of each on film uniformity and performance.

  2. Distributed performance counters

    Science.gov (United States)

    Davis, Kristan D; Evans, Kahn C; Gara, Alan; Satterfield, David L

    2013-11-26

    A plurality of first performance counter modules is coupled to a plurality of processing cores. The plurality of first performance counter modules is operable to collect performance data associated with the plurality of processing cores respectively. A plurality of second performance counter modules are coupled to a plurality of L2 cache units, and the plurality of second performance counter modules are operable to collect performance data associated with the plurality of L2 cache units respectively. A central performance counter module may be operable to coordinate counter data from the plurality of first performance counter modules and the plurality of second performance modules, the a central performance counter module, the plurality of first performance counter modules, and the plurality of second performance counter modules connected by a daisy chain connection.

  3. Laser processing of SnO2 electrode materials for manufacturing of 3D micro-batteries

    Science.gov (United States)

    Kohler, R.; Proell, J.; Ulrich, S.; Przybylski, M.; Pfleging, W.

    2011-03-01

    The material development for advanced lithium-ion batteries plays an important role in future mobile applications and energy storage systems. It is assumed that electrode materials made of nano-composited materials will improve battery lifetime and will lead to an enhancement of lithium diffusion and thus improve battery capacity and cyclability. A major problem concerning thin film electrodes is, that increasing film thickness leads to an increase in lithium diffusion path lengths and thereby a decrease in power density. To overcome this problem, the investigation of a 3D-battery system with an increased surface area is necessary. UV-laser micromachining was applied to create defined line or grating structures via mask imaging. SnO2 is a highly investigated anode material for lithium-ion batteries. Yet, the enormous volume changes occurring during electrochemical cycling lead to immense loss of capacity. The formation of micropatterns via laser ablation to create structures which enable the compensation of the volume expansion was investigated in detail. Thin films of SnO2 were deposited in Ar:O2 atmosphere via r.f. magnetron sputtering on silicon and stainless steel substrates. The thin films were studied with X-ray diffraction to determine their crystallinity. The electrochemical properties of the manufactured films were investigated via electrochemical cycling against a lithium anode.

  4. NMR study of electrode materials for lithium ion-batteries; Etude par RMN de materiaux d'electrode pour batteries lithium-ion

    Energy Technology Data Exchange (ETDEWEB)

    Chazel, C.

    2006-01-15

    This work is devoted to the study of LiMO{sub 2} et LiM{sub 2}O{sub 4} (M: transition metal) intercalation compounds used as electrode material for lithium-ion batteries. Solid state NMR allows one to characterise the local environment of the lithium ions present in these phases by the use of the hyperfine interactions due to the presence of some electron spin density coming from localised electrons (Fermi-contact shift) or itinerant electrons (Knight shift) on the lithium nucleus. By following the transformation of the LiNiO{sub 2} layered phase into the LiNi{sub 2}O{sub 4} spinel material using lithium NMR, we studied the nature of the asymmetric signal observed for LiNiO{sub 2}, and the influence of the departure from the ideal stoichiometry; we showed a coupled ion/electron hopping in Li{sub X}NiO{sub 2} phases linked to Li/vacancy and Ni{sup 3+}/Ni{sup 4+} ordering, and finally showed the existence of structural defects within the LiNi{sub 2}O{sub 4} spinel phase obtained by thermal treatment of Li{sub 0.5}NiO{sub 2}. Lithium NMR of the intercalated materials obtained from the LiTi{sub 2}O{sub 4} and Li{sub 4}Ti{sub 5}O{sub 12} spinels showed a metallic behaviour for Li{sub 2}Ti{sub 2}O{sub 4} with a Knight shift of the NMR signal similar to that of LiTi{sub 2}O{sub 4}, and signals intermediate in nature between Knight and Fermi-contact shifts for Li{sub 7}Ti{sub 5}O{sub 12}. (author)

  5. Differences in estimates of size distribution of beryllium powder materials using phase contrast microscopy, scanning electron microscopy, and liquid suspension counter techniques

    Directory of Open Access Journals (Sweden)

    Day Gregory A

    2007-02-01

    Full Text Available Abstract Accurate characterization of the physicochemical properties of aerosols generated for inhalation toxicology studies is essential for obtaining meaningful results. Great emphasis must also be placed on characterizing particle properties of materials as administered in inhalation studies. Thus, research is needed to identify a suite of techniques capable of characterizing the multiple particle properties (i.e., size, mass, surface area, number of a material that may influence toxicity. The purpose of this study was to characterize the morphology and investigate the size distribution of a model toxicant, beryllium. Beryllium metal, oxides, and alloy particles were aerodynamically size-separated using an aerosol cyclone, imaged dry using scanning electron microscopy (SEM, then characterized using phase contrast microscopy (PCM, a liquid suspension particle counter (LPC, and computer-controlled SEM (CCSEM. Beryllium metal powder was compact with smaller sub-micrometer size particles attached to the surface of larger particles, whereas the beryllium oxides and alloy particles were clusters of primary particles. As expected, the geometric mean (GM diameter of metal powder determined using PCM decreased with aerodynamic size, but when suspended in liquid for LPC or CCSEM analysis, the GM diameter decreased by a factor of two (p

  6. Li-rich Li-Si alloy as a lithium-containing negative electrode material towards high energy lithium-ion batteries.

    Science.gov (United States)

    Iwamura, Shinichiroh; Nishihara, Hirotomo; Ono, Yoshitaka; Morito, Haruhiko; Yamane, Hisanori; Nara, Hiroki; Osaka, Tetsuya; Kyotani, Takashi

    2015-01-28

    Lithium-ion batteries (LIBs) are generally constructed by lithium-including positive electrode materials, such as LiCoO2, and lithium-free negative electrode materials, such as graphite. Recently, lithium-free positive electrode materials, such as sulfur, are gathering great attention from their very high capacities, thereby significantly increasing the energy density of LIBs. Though the lithium-free materials need to be combined with lithium-containing negative electrode materials, the latter has not been well developed yet. In this work, the feasibility of Li-rich Li-Si alloy is examined as a lithium-containing negative electrode material. Li-rich Li-Si alloy is prepared by the melt-solidification of Li and Si metals with the composition of Li21Si5. By repeating delithiation/lithiation cycles, Li-Si particles turn into porous structure, whereas the original particle size remains unchanged. Since Li-Si is free from severe constriction/expansion upon delithiation/lithiation, it shows much better cyclability than Si. The feasibility of the Li-Si alloy is further examined by constructing a full-cell together with a lithium-free positive electrode. Though Li-Si alloy is too active to be mixed with binder polymers, the coating with carbon-black powder by physical mixing is found to prevent the undesirable reactions of Li-Si alloy with binder polymers, and thus enables the construction of a more practical electrochemical cell.

  7. Electrochemical behaviors of a wearable woven textile Li-ion battery consisting of a core and wound electrode fibers coated with active materials

    Science.gov (United States)

    Kim, C.; Bang, S.; Zhou, D.; Yun, S.

    2017-04-01

    A new fiber-type Li-ion battery that consists of carbon nanotube fibers deposited with active materials has been developed and tested. The active materials, LiMn2O4 and Li4Ti5O12, were deposited on the surface of carbon nanotube fibers in order to use as electrodes. Tensile strength of the CNT fibers with active material was measured by tensile tests to investigate the mechanical characteristics. Electrochemical property is also measured by a battery tester during charging and discharging. The results show that current discharge capacity is about 25 mAh/g between 3.0 V and 4.2 V. That means the fiber with active materials is good for an anode electrode. Mathematical material models considering the lithium concentration and the length of Li-C bond have been established in order to predict the effective elastic modulus of electrode composite materials.

  8. Numerical Analysis and Optimization on Piezoelectric Properties of 0–3 Type Piezoelectric Cement-Based Materials with Interdigitated Electrodes

    Directory of Open Access Journals (Sweden)

    Jianlin Luo

    2017-03-01

    Full Text Available The health conditions of complicated concrete structures require intrinsic cement-based sensors with a fast sensing response and high accuracy. In this paper, static, modal, harmonic, and transient dynamic analyses for the 0–3 type piezoelectric cement-based material with interdigitated electrodes (IEPCM wafer were investigated using the ANSYS finite element numerical approach. Optimal design of the IEPCM was further implemented with electrode distance (P, electrode width (W, and wafer density (H as the main parameters. Analysis results show that the maximum stress and strain in the x-polarization direction of the IEPCM are 2.6 and 3.19 times higher than that in the y-direction, respectively; there exists no repetition frequency phenomenon for the IEPCM. These indicate 0–3 type IEPCM possesses good orthotropic features, and lateral driving capacity notwithstanding, a hysteresis effect exists. Allowing for the wafer width (Wp of 1 mm, the optimal design of the IEPCM wafer arrives at the best physical values of H, W and P are 6.2, 0.73 and 1.02 mm respectively, whereas the corresponding optimal volume is 10.9 mm3.

  9. Space charge behaviour in an epoxy resin: the influence of fillers, temperature and electrode material

    Energy Technology Data Exchange (ETDEWEB)

    Gallot-Lavallee, O [Laboratoire de Genie Electrique de Toulouse, Universite Paul Sabatier-118, Route de Narbonne, Toulouse 31062 (France); Teyssedre, G [Laboratoire de Genie Electrique de Toulouse, Universite Paul Sabatier-118, Route de Narbonne, Toulouse 31062 (France); Laurent, C [Laboratoire de Genie Electrique de Toulouse, Universite Paul Sabatier-118, Route de Narbonne, Toulouse 31062 (France); Rowe, S [Direction des Recherches Materiaux, Schneider Electric SA-20, Rue Henri Tarze, Grenoble 38050 (France)

    2005-06-21

    This study aims to characterize the behaviour of the space charge in an epoxy resin used as electrical insulation in systems such as transformers and bus bars. Temperature, field level, filler content and nature of the electrodes are the parameters that were considered. Space charge measurements were performed using the pulsed electro acoustic technique, in a range of field and temperature up to 40 kV mm{sup -1} and 72 deg. C, respectively, on gold-coated and un-coated samples. We discuss the possibility of performing space charge measurement on filled epoxy resin despite the piezoelectricity of quartz fillers. Under dc field we observed a quasi-symmetrical build-up of homocharges at both electrodes, followed by a substitution of the homocharges by heterocharges, mainly close to the cathode. In addition, we recorded the space charge behaviour just before breakdown on a filled sample at 72 deg. C under 12 kV mm{sup -1}.

  10. Graphene synthesized on porous silicon for active electrode material of supercapacitors

    Science.gov (United States)

    Su, B. B.; Chen, X. Y.; Halvorsen, E.

    2016-11-01

    We present graphene synthesized by chemical vapour deposition under atmospheric pressure on both porous nanostructures and flat wafers as electrode scaffolds for supercapacitors. A 3nm thin gold layer was deposited on samples of both porous and flat silicon for exploring the catalytic influence during graphene synthesis. Micro-four-point probe resistivity measurements revealed that the resistivity of porous silicon samples was nearly 53 times smaller than of the flat silicon ones when all the samples were covered by a thin gold layer after the graphene growth. From cyclic voltammetry, the average specific capacitance of porous silicon coated with gold was estimated to 267 μF/cm2 while that without catalyst layer was 145μF/cm2. We demonstrated that porous silicon based on nanorods can play an important role in graphene synthesis and enable silicon as promising electrodes for supercapacitors.

  11. Interconnecting Carbon Fibers with the In-situ Electrochemically Exfoliated Graphene as Advanced Binder-free Electrode Materials for Flexible Supercapacitor.

    Science.gov (United States)

    Zou, Yuqin; Wang, Shuangyin

    2015-07-07

    Flexible energy storage devices are highly demanded for various applications. Carbon cloth (CC) woven by carbon fibers (CFs) is typically used as electrode or current collector for flexible devices. The low surface area of CC and the presence of big gaps (ca. micro-size) between individual CFs lead to poor performance. Herein, we interconnect individual CFs through the in-situ exfoliated graphene with high surface area by the electrochemical intercalation method. The interconnected CFs are used as both current collector and electrode materials for flexible supercapacitors, in which the in-situ exfoliated graphene act as active materials and conductive "binders". The in-situ electrochemical intercalation technique ensures the low contact resistance between electrode (graphene) and current collector (carbon cloth) with enhanced conductivity. The as-prepared electrode materials show significantly improved performance for flexible supercapacitors.

  12. Accelerating rate calorimetry studies of the reactions between ionic liquids and charged lithium ion battery electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yadong; Dahn, J.R. [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS (Canada); Zaghib, K.; Guerfi, A. [Institut de Recherche d' Hydro-Quebec, 1800 Lionel-Boulet, Varennes, Que. (Canada); Bazito, Fernanda F.C.; Torresi, Roberto M. [Instituto de Quimica Universidade de Sao Paulo, CP 26077, 05513-970 Sao Paulo (Brazil)

    2007-06-30

    Using accelerating rate calorimetry (ARC), the reactivity between six ionic liquids (with and without added LiPF{sub 6}) and charged electrode materials is compared to the reactivity of standard carbonate-based solvents and electrolytes with the same electrode materials. The charged electrode materials used were Li{sub 1}Si, Li{sub 7}Ti{sub 4}O{sub 12} and Li{sub 0.45}CoO{sub 2}. The experiments showed that not all ionic liquids are safer than conventional electrolytes/solvents. Of the six ionic liquids tested, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMI-FSI) shows the worst safety properties, and is much worse than conventional electrolyte. 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI) and 1-propyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (Py13-FSI) show similar reactivity to carbonate-based electrolyte. The three ionic liquids 1-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide (BMMI-TFSI), 1-butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide (Pp14-TFSI) and N-trimethyl-N-butylammonium bis(trifluoromethanesulfonyl)imide (TMBA-TFSI) show similar reactivity and are much safer than the conventional carbonate-based electrolyte. A comparison of the reactivity of ionic liquids with common anions and cations shows that ionic liquids with TFSI{sup -} are safer than those with FSI{sup -}, and liquids with EMI{sup +} are worse than those with BMMI{sup +}, Py13{sup +}, Pp14{sup +} and TMBA{sup +}. (author)

  13. Dilute NiO/carbon nanofiber composites derived from metal organic framework fibers as electrode materials for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ying; Yang, Feng; Hu, Hongru; Lee, Sungsik; Wang, Yue; Zhao, Hairui; Zeng, Dehong; Zhou, Biao; Hao, Shijie

    2017-01-01

    A new type of carbon nanofiber (CNF) dominated electrode materials decorated with dilute NiO particles (NiO/CNF) has been in situ fabricated by direct pyrolysis of Ni, Zn-containing metal organic framework fibers, which are skillfully constructed by assembling different proportional NiCl2·6H2O and Zn(Ac)2·2H2O with trimesic acid in the presence of N,N-dimethylformamide. With elegant combination of advantages of CNF and evenly dispersed NiO particles, as well as successful modulation of conductivity and porosity of final composites, our NiO/CNF composites display well-defined capacitive features. A high capacitance of 14926 F g–1 was obtained in 6 M KOH electrolyte when the contribution from 0.43 wt% NiO was considered alone, contributing to over 35% of the total capacitance (234 F g–1 ). This significantly exceeds its theoretical specific capacitance of 2584 F g–1. It has been established from the Ragone plot that a largest energy density of 33.4 Wh kg–1 was obtained at the current density of 0.25 A g–1. Furthermore, such composite electrode materials show good rate capability and outstanding cycling stability up to 5000 times (only 10% loss). The present study provides a brand-new approach to design a high capacitance and stable supercapacitor electrode and the concept is extendable to other composite materials. Keywords: Metal organic framework; Nickel oxide; Carbon nanofiber; In situ synthesis; Capacitance

  14. Facile construction of 3D graphene/MoS2 composites as advanced electrode materials for supercapacitors

    Science.gov (United States)

    Sun, Tianhua; Li, Zhangpeng; Liu, Xiaohong; Ma, Limin; Wang, Jinqing; Yang, Shengrong

    2016-11-01

    Flower-like molybdenum disulfide (MoS2) microstructures are synthesized based on three-dimensional graphene (3DG) skeleton via a simple and facile one-step hydrothermal method, aiming at constructing series of novel composite electrode materials of 3DG/MoS2 with high electrochemical performances for supercapacitors. The electrochemical properties of the samples are evaluated by cyclic voltammetry and galvanostatic charge/discharge tests. Specifically, the optimal 3DG/MoS2 composite exhibits remarkable performances with a high specific capacitance of 410 F g-1 at a current density of 1 A g-1 and an excellent cycling stability with ca. 80.3% capacitance retention after 10,000 continuous charge-discharge cycles at a high current density of 2 A g-1, making it adaptive for high-performance supercapacitors. The enhanced electrochemical performances can be ascribed to the combination of 3DG and flower-like MoS2, which provides excellent charge transfer network and electrolyte diffusion channels while effectively prevents the collapse, aggregation and morphology change of active materials during charge-discharge process. The results demonstrate that 3DG/MoS2 composite is one of the attractive electrode materials for supercapacitors.

  15. Effect of electrode material on characteristics of non-volatile resistive memory consisting of Ag2S nanoparticles

    Science.gov (United States)

    Jang, Jaewon

    2016-07-01

    In this study, Ag2S nanoparticles are synthesized and used as the active material for two-terminal resistance switching memory devices. Sintered Ag2S films are successfully crystallized on plastic substrates with synthesized Ag2S nanoparticles, after a relatively low-temperature sintering process (200 °C). After the sintering process, the crystallite size is increased from 6.8 nm to 80.3 nm. The high ratio of surface atoms to inner atoms of nanoparticles reduces the melting point temperature, deciding the sintering process temperature. In order to investigate the resistance switching characteristics, metal/Ag2S/metal structures are fabricated and tested. The effect of the electrode material on the non-volatile resistive memory characteristics is studied. The bottom electrochemically inert materials, such as Au and Pt, were critical for maintaining stable memory characteristics. By using Au and Pt inert bottom electrodes, we are able to significantly improve the memory endurance and retention to more than 103 cycles and 104 sec, respectively.

  16. Conductive Polymer Binder for High-Tap-Density Nanosilicon Material for Lithium-Ion Battery Negative Electrode Application.

    Science.gov (United States)

    Zhao, Hui; Wei, Yang; Qiao, Ruimin; Zhu, Chenhui; Zheng, Ziyan; Ling, Min; Jia, Zhe; Bai, Ying; Fu, Yanbao; Lei, Jinglei; Song, Xiangyun; Battaglia, Vincent S; Yang, Wanli; Messersmith, Phillip B; Liu, Gao

    2015-12-09

    High-tap-density silicon nanomaterials are highly desirable as anodes for lithium ion batteries, due to their small surface area and minimum first-cycle loss. However, this material poses formidable challenges to polymeric binder design. Binders adhere on to the small surface area to sustain the drastic volume changes during cycling; also the low porosities and small pore size resulting from this material are detrimental to lithium ion transport. This study introduces a new binder, poly(1-pyrenemethyl methacrylate-co-methacrylic acid) (PPyMAA), for a high-tap-density nanosilicon electrode cycled in a stable manner with a first cycle efficiency of 82%-a value that is further improved to 87% when combined with graphite material. Incorporating the MAA acid functionalities does not change the lowest unoccupied molecular orbital (LUMO) features or lower the adhesion performance of the PPy homopolymer. Our single-molecule force microscopy measurement of PPyMAA reveals similar adhesion strength between polymer binder and anode surface when compared with conventional polymer such as homopolyacrylic acid (PAA), while being electronically conductive. The combined conductivity and adhesion afforded by the MAA and pyrene copolymer results in good cycling performance for the high-tap-density Si electrode.

  17. Ni3S4和CoS原位一步制备及其染料敏化电池对电极性能研究%One-step in situ growth of Ni3S4and CoS and their effect as counter electrodes on the performance for dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    郑琳杰; 鲍潮; 陈琳琳; 汪佳丽; 孙小华

    2016-01-01

    Nickel and cobalt sulfide were successfully prepared by a simple one-step solvent thermal method on the conductive glass of fluorine doped tin oxide, which were used as counter electrodes for dye-sensitized solar cells. The synthesised phase, surface morphology, electrocatalytic and photovotaic performances of the two transition metal sulfide were investigated with X ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy(EIS), Tafel polarization curves and photoelectric current density voltage characteristic curves (J-V). The results show that the metal sulfide are Ni3S4and CoS, Meanwhile, the two materials deposited on FTO are thin films which both consist of massive nanoparticles. Ni3S4 displays a superior electrocatalytic activity and lower series resistance, which results in a higher short-circuit current density (15.17×10–3A/cm2) and higher photoelectrical conversion efficiency (6.78%) than that of referenced Pt(6.40%). Although photoelectrical conversion efficiency of CoS is slightly worse(6.13%), it also demonstrates similar electrocatalytic and photoelectrical activity compared with the referenced Pt counter electrode.%通过简单的一步溶剂热法在氟掺杂氧化锡导电玻璃上成功制备了两种镍、钴的硫化物对电极。并通过X射线衍射(XRD)、扫描电子显微镜(SEM)、循环伏安测试(CV)、电化学阻抗谱分析(EIS)、Tafel极化曲线以及光电流密度-电压特性曲线(J-V)分别研究了其物相、表面形貌、电催化性能和光伏性能。结果表明,这两种硫化物分别为Ni3S4和CoS,且都为颗粒状薄膜。Ni3S4具有相对更高的电催化活性和更低的串联电阻,从而其电池拥有更高的短路电流密度(15.17×10–3A/cm2),显示出比Pt对电极电池(6.40%)更高的光电转化效率6.78%。虽然CoS对电极的光伏性能稍差(6.13%),但也表现出与Pt对电极相比拟的性能。

  18. Optimization of Electrode Material for EDM Die-sinking of Titanium Alloy Grade 5 - Ti6Al4V

    Directory of Open Access Journals (Sweden)

    Sangeeth Suresh

    2016-08-01

    Full Text Available Titanium alloy grade 5, Ti6Al4V, is extensively gaining importance in the industrial environment, specifically in aerospace, medical and automotive domains, mainly due to its exceptional blend of mechanical properties like high hardness which is further heat treatable, high strength-to-weight ratio which makes it light, high corrosion and temperature resistance etc. However, the same properties undervalue Ti6Al4V as a conventionally difficult-to-machine material. Rapid tool wear, excessive heat generation, dimensional instability and loss of surface integrity are the issues that plague the conventional machining of Ti6Al4V.  In view of these facts, non-traditional machining processes like electron discharge machining (EDM - die sinking and wire cut prove to be a substitute for the conventional machining. In this study, an experimental optimization of EDM die-sinking electrode materials among copper, brass and graphite, is carried out. Experimental design is created using a statistical tool and actual machining is carried out to record the surface roughness, variations on the surface hardness and dimensional stability. Quality evaluation and statistical analysis substantiates graphite electrodes to produce better surface finish-Ra 2.05microns with minimal dimensional variation-less than 10%-when operated at minimum spark gaps. It is inferred that graphite electrodes exhibit higher resistivity towards current than its counterparts thus passing minimum spark energy preventing excessive self-wear and a dimensionally accurate workpiece. The depth of machining highly impacts the variations on the surface hardness post machining.

  19. Pr4Ni3O10+δ: A new promising oxygen electrode material for solid oxide fuel cells

    Science.gov (United States)

    Vibhu, Vaibhav; Rougier, Aline; Nicollet, Clément; Flura, Aurélien; Fourcade, Sébastien; Penin, Nicolas; Grenier, Jean-Claude; Bassat, Jean-Marc

    2016-06-01

    The present work is focused on the study of Pr4Ni3O10+δ as a new cathode material for Solid Oxide Fuel Cells (SOFCs). The structural study leads to an indexation in orthorhombic structure with Fmmm space group, this structure being thermally stable throughout the temperature range up to 1000 °C under air and oxygen. The variation of oxygen content (10+δ) as a function of temperature under different atmospheres show that Pr4Ni3O10+δ is always oxygen over-stoichiometric, which further suggests its MIEC properties. The polarization resistance (Rp) of Pr4Ni3O10+δ electrode is measured for GDC/co-sintered and two-step sintered half cells. The Rp for co-sintered sample is found to be 0.16 Ω cm2 at 600 °C under air, which is as low as the one of highest performing Pr2NiO4+δ nickelate (Rp = 0.15 Ω cm2 at 600 °C). Moreover, an anode supported (Ni-YSZ//YSZ) single cell including GDC//Pr4Ni3O10+δ co-sintered electrode shows a maximum power density of 1.60 W cm-2 at 800 °C and 0.68 W cm-2 at 700 °C. Here, the work is emphasized on the very close electrochemical performance of Pr4Ni3O10+δ compared to the one of Pr2NiO4+δ with higher chemical stability, which gives great interests to consider this material as a very interesting oxygen-electrode for SOFCs.

  20. Synthesis of a novel electrode material containing phytic acid-polyaniline nanofibers for simultaneous determination of cadmium and lead ions.

    Science.gov (United States)

    Huang, Hui; Zhu, Wencai; Gao, Xiaochun; Liu, Xiuyu; Ma, Houyi

    2016-12-01

    The development of nanostructured conducting polymers based materials for electrochemical applications has attracted intense attention due to their environmental stability, unique reversible redox properties, abundant electron active sites, rapid electron transfer and tunable conductivity. Here, a phytic acid doped polyaniline nanofibers based nanocomposite was synthesized using a simple and green method, the properties of the resulting nanomaterial was characterized by electrochemical impedance spectroscopy (EIS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive s