WorldWideScience

Sample records for film anode material

  1. Preparation and properties of antimony thin film anode materials

    Institute of Scientific and Technical Information of China (English)

    SU Shufa; CAO Gaoshao; ZHAO Xinbing

    2004-01-01

    Metallic antimony thin films were deposited by magnetron sputtering and electrodeposition. Electrochemical properties of the thin film as anode materials for lithium-ion batteries were investigated and compared with those of antimony powder. It was found that both magnetron sputtering and electrodeposition are easily controllable processes to deposit antimony films with fiat charge/discharge potential plateaus. The electrochemical performances of antimony thin films, especially those prepared with magnetron sputtering, are better than those of antimony powder. The reversible capacities of the magnetron sputtered antimony thin film are above 400 mA h g-1 in the first 15 cycles.

  2. Facile synthesis of silicon films by photosintering as anode materials for lithium-ion batteries

    Science.gov (United States)

    Chen, Wei; Jiang, Nan; Fan, Zhongli; Dhanabalan, Abirami; Chen, Chunhui; Li, Yunjun; Yang, Mohshi; Wang, Chunlei

    2012-09-01

    The silicon films as anode materials for lithium-ion batteries were fabricated by the cost-effective, high-throughput photosintering process. The thinner Si film (1.3 μm) exhibited larger storage capacity and better cyclability compared to the thicker one (4.2 μm) due to the close contact of the fused silicon nanoparticles with the substrate. Moreover, the addition of silver nanoparticles improved the conductivity of silicon film and facilitated the amorphous phase formation, resulting in enhanced capacity and cyclability. The photosintering approach highlights the advantage in the flexible and practicable manufacture and shows the promising prospects for developing high-performance Si-based anode materials.

  3. HfO2/porous anodic alumina composite films for multifunctional data storage media materials under electric field control

    Science.gov (United States)

    Qi, Li-Qian; Pan, Di-Ya; Li, Jun-Qing; Liu, Li-Hu; Sun, Hui-Yuan

    2017-03-01

    New materials for achieving direct electric field control of ferromagnetism and resistance behavior are highly desirable in the development of multifunctional data storage devices. In this paper, HfO2 nanoporous films have been fabricated on porous anodic alumina (PAA) substrates by DC-reactive magnetron sputtering. Electrically induced resistive switching (RS) and modulated room temperature ferromagnetism are simultaneously found in a Ag/HfO2/PAA/Al (Ag/HP/Al) heterostructure. The switching mechanism between low resistance state and high resistance state is generally attributed to the formation/rupture of conductive filaments which may consist of oxygen vacancies. The combination of the electric field control of magnetization change and RS makes HP films possible for the multifunctional data storage media materials.

  4. Ellipsometry of anodic film growth

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.G.

    1978-08-01

    An automated computer interpretation of ellisometer measurements of anodic film growth was developed. Continuous mass and charge balances were used to utilize more fully the time dependence of the ellipsometer data and the current and potential measurements. A multiple-film model was used to characterize the growth of films which proceeds via a dissolution--precipitation mechanism; the model also applies to film growth by adsorption and nucleation mechanisms. The characteristic parameters for film growth describe homogeneous and heterogeneous crystallization rates, film porosities and degree of hydration, and the supersaturation of ionic species in the electrolyte. Additional descriptions which may be chosen are patchwise film formation, nonstoichiometry of the anodic film, and statistical variations in the size and orientation of secondary crystals. Theories were developed to describe the optical effects of these processes. An automatic, self-compensating ellipsometer was used to study the growth in alkaline solution of anodic films on silver, cadmium, and zinc. Mass-transport conditions included stagnant electrolyte and forced convection in a flow channel. Multiple films were needed to characterize the optical properties of these films. Anodic films grew from an electrolyte supersatuated in the solution-phase dissolution product. The degree of supersaturation depended on transport conditions and had a major effect on the structure of the film. Anodic reaction rates were limited by the transport of charge carriers through a primary surface layer. The primary layers on silver, zinc, and cadmium all appeared to be nonstoichiometric, containing excess metal. Diffusion coefficients, transference numbers, and the free energy of adsorption of zinc oxide were derived from ellipsometer measurements. 97 figures, 13 tables, 198 references.

  5. Ellipsometry of anodic film growth

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.G.

    1978-08-01

    An automated computer interpretation of ellisometer measurements of anodic film growth was developed. Continuous mass and charge balances were used to utilize more fully the time dependence of the ellipsometer data and the current and potential measurements. A multiple-film model was used to characterize the growth of films which proceeds via a dissolution--precipitation mechanism; the model also applies to film growth by adsorption and nucleation mechanisms. The characteristic parameters for film growth describe homogeneous and heterogeneous crystallization rates, film porosities and degree of hydration, and the supersaturation of ionic species in the electrolyte. Additional descriptions which may be chosen are patchwise film formation, nonstoichiometry of the anodic film, and statistical variations in the size and orientation of secondary crystals. Theories were developed to describe the optical effects of these processes. An automatic, self-compensating ellipsometer was used to study the growth in alkaline solution of anodic films on silver, cadmium, and zinc. Mass-transport conditions included stagnant electrolyte and forced convection in a flow channel. Multiple films were needed to characterize the optical properties of these films. Anodic films grew from an electrolyte supersatuated in the solution-phase dissolution product. The degree of supersaturation depended on transport conditions and had a major effect on the structure of the film. Anodic reaction rates were limited by the transport of charge carriers through a primary surface layer. The primary layers on silver, zinc, and cadmium all appeared to be nonstoichiometric, containing excess metal. Diffusion coefficients, transference numbers, and the free energy of adsorption of zinc oxide were derived from ellipsometer measurements. 97 figures, 13 tables, 198 references.

  6. Investigation of the mechanical and chemical characteristics of nanotubular and nano-pitted anodic films on grade 2 titanium dental implant materials.

    Science.gov (United States)

    Weszl, Miklós; Tóth, Krisztián László; Kientzl, Imre; Nagy, Péter; Pammer, Dávid; Pelyhe, Liza; Vrana, Nihal E; Scharnweber, Dieter; Wolf-Brandstetter, Cornelia; Joób F, Árpád; Bognár, Eszter

    2017-09-01

    The objective of this study was to investigate the reproducibility, mechanical integrity, surface characteristics and corrosion behavior of nanotubular (NT) titanium oxide arrays in comparison with a novel nano-pitted (NP) anodic film. Surface treatment processes were developed to grow homogenous NT and NP anodic films on the surface of grade 2 titanium discs and dental implants. The effect of process parameters on the surface characteristics and reproducibility of the anodic films was investigated and optimized. The mechanical integrity of the NT and NP anodic films were investigated by scanning electron microscopy, surface roughness measurement, scratch resistance and screwing tests, while the chemical and physicochemical properties were investigated in corrosion tests, contact angle measurement and X-ray photoelectron spectroscopy (XPS). The growth of NT anodic films was highly affected by process parameters, especially by temperature, and they were apt to corrosion and exfoliation. In contrast, the anodic growth of NP film showed high reproducibility even on the surface of 3-dimensional screw dental implants and they did not show signs of corrosion and exfoliation. The underlying reason of the difference in the tendency for exfoliation of the NT and NP anodic films is unclear; however the XPS analysis revealed fluorine dopants in a magnitude larger concentration on NT anodic film than on NP surface, which was identified as a possible causative. Concerning other surface characteristics that are supposed to affect the biological behavior of titanium implants, surface roughness values were found to be similar, whereas considerable differences were revealed in the wettability of the NT and NP anodic films. Our findings suggest that the applicability of NT anodic films on the surface of titanium bone implants may be limited because of mechanical considerations. In contrast, it is worth to consider the applicability of nano-pitted anodic films over nanotubular arrays

  7. Ultraviolet photoluminescence of porous anodic alumina films

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Photoluminescence (PL) properties of porous anodic alumina (PAA) films prepared by using electrochemical anodization technique in a mixed solution of oxalic and sulfuric acid have been investigated. The PAA films have an intensive ultraviolet PL emission around 350 nm, of which a possible PL mechanism has been proposed. It was found that the incorporated oxalic ions, which could transform into PL centers and exist in the PAA films, are responsible for this ultraviolet PL emission.

  8. Pulsed laser deposited Cr{sub 2}O{sub 3} nanostructured thin film on graphene as anode material for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Khamlich, S., E-mail: skhamlich@gmail.com [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape Province (South Africa); Nuru, Z.Y. [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape Province (South Africa); Bello, A.; Fabiane, M.; Dangbegnon, J.K.; Manyala, N. [Department of Physics, SARChI Chair in Carbon Technology and Materials, Institute of Applied Materials, University of Pretoria, Pretoria (South Africa); Maaza, M. [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape Province (South Africa)

    2015-07-15

    Graphical abstract: A different approach for the fabrication of an anode material system that comprises pulsed laser-deposited (PLD) Cr{sub 2}O{sub 3} grown on few layer graphene (FLG) by chemical vapor deposition (CVD) was used. The electrochemical performance of Cr{sub 2}O{sub 3} nanostructured thin film was improved by FLG, which make it a promising candidate for future lithium-ion batteries application. - Highlights: • Pulsed laser deposition technique was used to deposit Cr{sub 2}O{sub 3} on few-layer graphene (FLG). • FLG improved the electrochemical performance of Cr{sub 2}O{sub 3} nanostructured thin film. • Good stable cycle of Cr{sub 2}O{sub 3}/FLG/Ni electrode make it one of the promise anode materials for future lithium-ion batteries. - Abstract: Pulsed laser deposition technique was used to deposit Cr{sub 2}O{sub 3} nanostructured thin film on a chemical vapor deposited few-layer graphene (FLG) on nickel (Ni) substrate for application as anode material for lithium-ion batteries. The experimental results show that graphene can effectively enhance the electrochemical property of Cr{sub 2}O{sub 3}. For Cr{sub 2}O{sub 3} thin film deposited on Ni (Cr{sub 2}O{sub 3}/Ni), a discharge capacity of 747.8 mA h g{sup −1} can be delivered during the first lithiation process. After growing Cr{sub 2}O{sub 3} thin film on FLG/Ni, the initial discharge capacity of Cr{sub 2}O{sub 3}/FLG/Ni was improved to 1234.5 mA h g{sup −1}. The reversible lithium storage capacity of the as-grown material is 692.2 mA h g{sup −1} after 100 cycles, which is much higher than that of Cr{sub 2}O{sub 3}/Ni (111.3 mA h g{sup −1}). This study reveals the differences between the two material systems and emphasizes the role of the graphene layers in improving the electrochemical stability of the Cr{sub 2}O{sub 3} nanostructured thin film.

  9. Corrosion Behaviour of Titanium Anodized Film in Different Corrosive Environments

    Directory of Open Access Journals (Sweden)

    Mr. Sunil D. Kahar

    2014-07-01

    Full Text Available Anodizing is an electrochemical process in which thickness of the natural oxide layer is increased and converted it into a decorative, durable, corrosion-resistant film. Titanium is used as a biocompatible material in human implants due to its excellent corrosion and wears resistance. Stable, continuous, highly adherent, and protective oxide films can be developed on titanium using various acid or alkaline baths. Anodizing of titanium generates a spectrum of different color without use of dyes. This spectrum of color dependent on the thickness of the oxide, voltage ranges, interference of light reflecting off the oxide surface and reflecting off the underlying metal surface. The anodized film of Titanium is mainly consists of TiO2 or mixtures of TiO2 & Ti2O3 etc. In the present work, Pure Titanium plate has been anodized using bath of Chromic Acid at different voltage range. The anodized film is characterized by visual observation, SEM & EDAX analysis & A.C Impedance Spectroscopy, while the corrosion studies were performed using Potentiodynamic studies were performed in 3.5% NaCl & 0.1N H2SO4. The Results show that the anodized film of Titanium show different spectrum of colors from Brown-Violet-Tea or Peacock. SEM & EDAX analyses show that the anodized film of Titanium is mainly made up of TiO2 and Ti2O3. Potentiodynamic study implies that the film developed on Titanium using the bath of Chromic Acid exhibits good corrosion resistance. The A.C. Impedance study shows that the film is more compact, adherent and more uniform in chromic acid bath.

  10. Improving the Cycling Life of Aluminum and Germanium Thin Films for use as Anodic Materials in Li-Ion Batteries.

    Energy Technology Data Exchange (ETDEWEB)

    Hudak, Nicholas [Dominican Univ., River Forest, IL (United States); Huber, Dale L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gulley, Gerald [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    The cycling of high-capacity electrode materials for lithium-ion batteries results in significant volumetric expansion and contraction, and this leads to mechanical failure of the electrodes. To increase battery performance and reliability, there is a drive towards the use of nanostructured electrode materials and nanoscale surface coatings. As a part of the Visiting Faculty Program (VFP) last summer, we examined the ability of aluminum oxide and gold film surface coatings to improve the mechanical and cycling properties of vapor-deposited aluminum films in lithium-ion batteries. Nanoscale gold coatings resulted in significantly improved cycling behavior for the thinnest aluminum films whereas aluminum oxide coatings did not improve the cycling behavior of the aluminum films. This summer we performed a similar investigation on vapor-deposited germanium, which has an even higher theoretical capacity per unit mass than aluminum. Because the mechanism of lithium-alloying is different for each electrode material, we expected the effects of coating the germanium surface with aluminum oxide or gold to differ significantly from previous observations. Indeed, we found that gold coatings gave only small or negligible improvements in cycling behavior of germanium films, but aluminum oxide (Al2O3) coatings gave significant improvements in cycling over the range of film thicknesses tested.

  11. Anodized Ti3SiC2 As an Anode Material for Li-ion Microbatteries.

    Science.gov (United States)

    Tesfaye, Alexander T; Mashtalir, Olha; Naguib, Michael; Barsoum, Michel W; Gogotsi, Yury; Djenizian, Thierry

    2016-07-06

    We report on the synthesis of an anode material for Li-ion batteries by anodization of a common MAX phase, Ti3SiC2, in an aqueous electrolyte containing hydrofluoric acid (HF). The anodization led to the formation of a porous film containing anatase, a small quantity of free carbon, and silica. By varying the anodization parameters, various oxide morphologies were produced. The highest areal capacity was achieved by anodization at 60 V in an aqueous electrolyte containing 0.1 v/v HF for 3 h at room temperature. After 140 cycles performed at multiple applied current densities, an areal capacity of 380 μAh·cm(-2) (200 μA·cm(-2)) has been obtained, making this new material, free of additives and binders, a promising candidate as a negative electrode for Li-ion microbatteries.

  12. Synthesis of Mesoporous Lithium Titanate Thin Films and Monoliths as an Anode Material for High-Rate Lithium-Ion Batteries.

    Science.gov (United States)

    Balcı, Fadime Mert; Kudu, Ömer Ulaş; Yılmaz, Eda; Dag, Ömer

    2016-12-23

    Mesoporous Li4 Ti5 O12 (LTO) thin film is an important anode material for lithium-ion batteries (LIBs). Mesoporous films could be prepared by self-assembly processes. A molten-salt-assisted self-assembly (MASA) process is used to prepare mesoporous thin films of LTOs. Clear solutions of CTAB, P123, LiNO3 , HNO3 , and Ti(OC4 H9 )4 in ethanol form gel-like meso-ordered films upon either spin or spray coating. In the assembly process, the CTAB/P123 molar ratio of 14 is required to accommodate enough salt species in the mesophase, in which the Li(I) /P123 ratio can be varied between molar ratios of 28 and 72. Calcination of the meso-ordered films produces transparent mesoporous spinel LTO films that are abbreviated as Cxx-yyy-zzz or CAxx-yyy-zzz (C=calcined, CA=calcined-annealed, xx=Li(I) /P123 molar ratio, and yyy=calcination and zzz=annealing temperatures in Celsius) herein. All samples were characterized by using XRD, TEM, N2 -sorption, and Raman techniques and it was found that, at all compositions, the LTO spinel phase formed with or without an anatase phase as an impurity. Electrochemical characterization of the films shows excellent performance at different current rates. The CA40-350-450 sample performs best among all samples tested, yielding an average discharge capacity of (176±1) mA h g(-1) at C/2 and (139±4) mA h g(-1) at 50 C and keeping 92 % of its initial discharge capacity upon 50 cycles at C/2.

  13. Anodic Materials for Electrocatalytic Ozone Generation

    Directory of Open Access Journals (Sweden)

    Yun-Hai Wang

    2013-01-01

    Full Text Available Ozone has wide applications in various fields. Electrocatalytic ozone generation technology as an alternative method to produce ozone is attractive. Anodic materials have significant effect on the ozone generation efficiency. The research progress on anodic materials for electrocatalytic ozone generation including the cell configuration and mechanism is addressed in this review. The lead dioxide and nickel-antimony-doped tin dioxide anode materials are introduced in detail, including their structure, property, and preparation. Advantages and disadvantages of different anode materials are also discussed.

  14. Microfabrication of an anodic oxide film by anodizing laser-textured aluminium

    OpenAIRE

    2007-01-01

    A simple method for the fabrication of microstructures of an aluminium anodic oxide film (anodic alumina) by anodizing laser-textured aluminium is demonstrated. In the process, the aluminium substrate was first textured by a low power laser beam, and then the textured aluminium was subjected to anodizing, to develop a continuous, thick porous layer on the textured surface. Microstructures with a depth of a few to several tens of micrometres were fabricated successfully on the anodic oxide fil...

  15. Preparation of Aluminum Nanomesh Thin Films from an Anodic Aluminum Oxide Template as Transparent Conductive Electrodes

    Science.gov (United States)

    Li, Yiwen; Chen, Yulong; Qiu, Mingxia; Yu, Hongyu; Zhang, Xinhai; Sun, Xiao Wei; Chen, Rui

    2016-02-01

    We have employed anodic aluminum oxide as a template to prepare ultrathin, transparent, and conducting Al films with a unique nanomesh structure for transparent conductive electrodes. The anodic aluminum oxide template is obtained through direct anodization of a sputtered Al layer on a glass substrate, and subsequent wet etching creates the nanomesh metallic film. The optical and conductive properties are greatly influenced by experimental conditions. By tuning the anodizing time, transparent electrodes with appropriate optical transmittance and sheet resistance have been obtained. The results demonstrate that our proposed strategy can serve as a potential method to fabricate low-cost TCEs to replace conventional indium tin oxide materials.

  16. Excitation of anodized alumina films with a light source

    DEFF Research Database (Denmark)

    Aggerbeck, Martin; Canulescu, Stela; Rechendorff, K.;

    . The UV-VIS reflectance of Ti-doped anodized aluminium films was measured over the wavelength range of 200 nm to 900 nm. Titanium doped-anodized aluminium films with 5-15 wt% Ti were characterized. Changes in the diffuse light scattering of doped anodized aluminium films, and thus optical appearance......Optical properties of anodized aluminium alloys were determined by optical diffuse reflectance spectroscopy of such films. Samples with different concentrations of dopants were excited with a white-light source combined with an integrating sphere for fast determination of diffuse reflectance...

  17. Nanostructured ZnO-TiO2 thin film oxide as anode material in electrooxidation of organic pollutants. Application to the removal of dye Amido black 10B from water.

    Science.gov (United States)

    El-Kacemi, Sana; Zazou, Hicham; Oturan, Nihal; Dietze, Matthias; Hamdani, Mohamed; Es-Souni, Mohammed; Oturan, Mehmet A

    2017-01-01

    Electrochemical oxidative degradation of diazo dye Amido black 10B (AB10B) as model pollutant in water has been studied using nanostructured ZnO-TiO2 thin films deposited on graphite felt (GrF) substrate as anode. The influence of various operating parameters, namely the current intensity, the nature and concentration of catalyst, the nature of electrode materials (anode/cathode), and the adsorption of dye and ambient light were investigated. It was found that the oxidative degradation of AB10B followed pseudo first-order kinetics. The optimal operating conditions for the degradation of 0.12 mM (74 mg L(-1)) dye concentration and mineralization of its aqueous solution were determined as GrF-ZnO-TiO2 thin film anode, 100 mA current intensity, and 0.1 mM Fe(2+) (catalyst) concentration. Under these operating conditions, discoloration of AB10B solution was reached at 60 min while 6 h treatment needed for a mineralization degree of 91 %. Therefore, this study confirmed that the electrochemical process is effective for the degradation of AB10B in water using nanostructured ZnO-TiO2 thin film anodes.

  18. Structural transformation of nickel hydroxide films during anodic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Crocker, R.W.; Muller, R.H.

    1992-05-01

    The transformation of anodically formed nickel hydroxide/oxy-hydroxide electrodes has been investigated. A mechanism is proposed for the anodic oxidation reaction, in which the reaction interface between the reduced and oxidized phases of the electrode evolves in a nodular topography that leads to inefficient utilization of the active electrode material. In the proposed nodular transformation model for the anodic oxidation reaction, nickel hydroxide is oxidized to nickel oxy-hydroxide in the region near the metal substrate. Since the nickel oxy-hydroxide is considerably more conductive than the surrounding nickel hydroxide, as further oxidation occurs, nodular features grow rapidly to the film/electrolyte interface. Upon emerging at the electrolyte interface, the reaction boundary between the nickel hydroxide and oxy-hydroxide phases spreads laterally across the film/electrolyte interface, creating an overlayer of nickel oxy-hydroxide and trapping uncharged regions of nickel hydroxide within the film. The nickel oxy-hydroxide overlayer surface facilitates the oxygen evolution side reaction. Scanning tunneling microscopy of the electrode in its charged state revealed evidence of 80 {endash} 100 Angstrom nickel oxy-hydroxide nodules in the nickel hydroxide film. In situ spectroscopic ellipsometer measurements of films held at various constant potentials agree quantitatively with optical models appropriate to the nodular growth and subsequent overgrowth of the nickel oxy-hydroxide phase. A two-dimensional, numerical finite difference model was developed to simulate the current distribution along the phase boundary between the charged and uncharged material. The model was used to explore the effects of the physical parameters that govern the electrode behavior. The ratio of the conductivities of the nickel hydroxide and oxy-hydroxide phases was found to be the dominant parameter in the system.

  19. Structural transformation of nickel hydroxide films during anodic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Crocker, Robert W. [Univ. of California, Berkeley, CA (United States); Muller, Rolf H. [Univ. of California, Berkeley, CA (United States)

    1992-05-01

    The transformation of anodically formed nickel hydroxide/oxy-hydroxide electrodes has been investigated. A mechanism is proposed for the anodic oxidation reaction, in which the reaction interface between the reduced and oxidized phases of the electrode evolves in a nodular topography that leads to inefficient utilization of the active electrode material. In the proposed nodular transformation model for the anodic oxidation reaction, nickel hydroxide is oxidized to nickel oxy-hydroxide in the region near the metal substrate. Since the nickel oxy-hydroxide is considerably more conductive than the surrounding nickel hydroxide, as further oxidation occurs, nodular features grow rapidly to the film/electrolyte interface. Upon emerging at the electrolyte interface, the reaction boundary between the nickel hydroxide and oxy-hydroxide phases spreads laterally across the film/electrolyte interface, creating an overlayer of nickel oxy-hydroxide and trapping uncharged regions of nickel hydroxide within the film. The nickel oxy-hydroxide overlayer surface facilitates the oxygen evolution side reaction. Scanning tunneling microscopy of the electrode in its charged state revealed evidence of 80 - 100 Angstrom nickel oxy-hydroxide nodules in the nickel hydroxide film. In situ spectroscopic ellipsometer measurements of films held at various constant potentials agree quantitatively with optical models appropriate to the nodular growth and subsequent overgrowth of the nickel oxy-hydroxide phase. A two-dimensional, numerical finite difference model was developed to simulate the current distribution along the phase boundary between the charged and uncharged material. The model was used to explore the effects of the physical parameters that govern the electrode behavior. The ratio of the conductivities of the nickel hydroxide and oxy-hydroxide phases was found to be the dominant parameter in the system.

  20. Formation and Morphology of Anodic Oxide Films of Ti

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The morphology and structure of the oxide films of Ti in H3PO4 were investigated by galvanostatic anodization, SEM and XRD. The oxide film grew from some pores in the grooves to layered microdomains as increasing anodizing voltage. The crystallinity of the oxide films decreased with the increase of the concentration of the electrolyte. The model has been proposed for the growth of the oxide films by two steps, i.e. by uniform thickening and by local deposition.

  1. Anode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Manthiram, Arumugam; Applestone, Danielle; Yoon, Sukeun

    2017-03-21

    The current disclosure relates to an anode material with the general formula M.sub.ySb-M'O.sub.x--C, where M and M' are metals and M'O.sub.x--C forms a matrix containing M.sub.ySb. It also relates to an anode material with the general formula M.sub.ySn-M'C.sub.x--C, where M and M' are metals and M'C.sub.x--C forms a matrix containing M.sub.ySn. It further relates to an anode material with the general formula Mo.sub.3Sb.sub.7--C, where --C forms a matrix containing Mo.sub.3Sb.sub.7. The disclosure also relates to an anode material with the general formula M.sub.ySb-M'C.sub.x--C, where M and M' are metals and M'C.sub.x--C forms a matrix containing M.sub.ySb. Other embodiments of this disclosure relate to anodes or rechargeable batteries containing these materials as well as methods of making these materials using ball-milling techniques and furnace heating.

  2. New High-Energy Nanofiber Anode Materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiangwu; Fedkiw, Peter; Khan, Saad; Huang, Alex; Fan, Jiang

    2013-11-15

    The overall goal of the proposed work was to use electrospinning technology to integrate dissimilar materials (lithium alloy and carbon) into novel composite nanofiber anodes, which simultaneously had high energy density, reduced cost, and improved abuse tolerance. The nanofiber structure allowed the anodes to withstand repeated cycles of expansion and contraction. These composite nanofibers were electrospun into nonwoven fabrics with thickness of 50 μm or more, and then directly used as anodes in a lithium-ion battery. This eliminated the presence of non-active materials (e.g., conducting carbon black and polymer binder) and resulted in high energy and power densities. The nonwoven anode structure also provided a large electrode-electrolyte interface and, hence, high rate capacity and good lowtemperature performance capability. Following are detailed objectives for three proposed project periods. • During the first six months: Obtain anodes capable of initial specific capacities of 650 mAh/g and achieve ~50 full charge/discharge cycles in small laboratory scale cells (50 to 100 mAh) at the 1C rate with less than 20 percent capacity fade; • In the middle of project period: Assemble, cycle, and evaluate 18650 cells using proposed anode materials, and demonstrate practical and useful cycle life (750 cycles of ~70% state of charge swing with less than 20% capacity fade) in 18650 cells with at least twice improvement in the specific capacity than that of conventional graphite electrodes; • At the end of project period: Deliver 18650 cells containing proposed anode materials, and achieve specific capacities greater than 1200 mAh/g and cycle life longer than 5000 cycles of ~70% state of charge swing with less than 20% capacity fade.

  3. Formation of complex anodic films on porous alumina matrices

    Indian Academy of Sciences (India)

    Alexander Zahariev; Assen Girginov

    2003-04-01

    The kinetics of growth of complex anodic alumina films was investigated. These films were formed by filling porous oxide films (matrices) having deep pores. The porous films (matrices) were obtained voltastatically in (COOH)2 aqueous solution under various voltages. The filling was done by re-anodization in an electrolyte solution not dissolving the film. Data about the kinetics of re-anodization depending on the porosity of the matrices were obtained. On the other hand, the slopes of the kinetic curves during reanodization were calculated by two equations expressing the dependence of these slopes on the ionic current density. A discrepancy was ascertained between the values of the calculated slopes and those experimentally found. For this discrepancy a possible explanation is proposed, related to the temperature increase in the film, because of that the real current density significantly increases during re-anodization.

  4. Ellipsometric investigation of anodic zirconium oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Patrito, E.M.; Macagno, V.A. (Univ. Nacional de Cordoba, Cordoba (Argentina). Dept. de Fisicoquimica)

    1993-06-01

    The anodic oxidation of zirconium was studied by in situ ellipsometry together with capacity measurements. The oxides were grown under potentiodynamic, galvanostatic, and potentiostatic conditions up to final potentials of 100 V in 0.5M H[sub 2]SO[sub 4] solution. The refractive index of the oxides changes depending on the growth current. The films were slightly absorbing but their absorption coefficient was independent of the oxide growth conditions. Different methods of surface preparation including etching in hydrofluoric acid-based mixtures, electropolishing and mechanical polishing were used. The surfaces and oxides were characterized by SEM examination and XPS measurements. The surface pretreatment affects both the substrate and the oxide optical constants as well as the rate of oxide growth. The density and dielectric constant of the oxides were calculated performing simultaneous ellipsometric, coulometric, and capacity measurements.

  5. Honeycomb-inspired design of ultrafine SnO2@C nanospheres embedded in carbon film as anode materials for high performance lithium- and sodium-ion battery

    Science.gov (United States)

    Ao, Xiang; Jiang, Jianjun; Ruan, Yunjun; Li, Zhishan; Zhang, Yi; Sun, Jianwu; Wang, Chundong

    2017-08-01

    Tin oxide (SnO2) has been considered as one of the most promising anodes for advanced rechargeable batteries due to its advantages such as high energy density, earth abundance and environmental friendly. However, its large volume change during the Li-Sn/Na-Sn alloying and de-alloying processes will result in a fast capacity degradation over a long term cycling. To solve this issue, in this work we design and synthesize a novel honeycomb-like composite composing of carbon encapsulated SnO2 nanospheres embedded in carbon film by using dual templates of SiO2 and NaCl. Using these composites as anodes both in lithium ion batteries and sodium-ion batteries, no discernable capacity degradation is observed over hundreds of long term cycles at both low current density (100 mA g-1) and high current density (500 mA g-1). Such a good cyclic stability and high delivered capacity have been attributed to the high conductivity of the supported carbon film and hollow encapsulated carbon shells, which not only provide enough space to accommodate the volume expansion but also prevent further aggregation of SnO2 nanoparticles upon cycling. By engineering electrodes of accommodating high volume expansion, we demonstrate a prototype to achieve high performance batteries, especially high-power batteries.

  6. Anode materials for lithium-ion batteries

    Science.gov (United States)

    Sunkara, Mahendra Kumar; Meduri, Praveen; Sumanasekera, Gamini

    2014-12-30

    An anode material for lithium-ion batteries is provided that comprises an elongated core structure capable of forming an alloy with lithium; and a plurality of nanostructures placed on a surface of the core structure, with each nanostructure being capable of forming an alloy with lithium and spaced at a predetermined distance from adjacent nanostructures.

  7. Tracer studies of anodic films formed on aluminium in malonic and oxalic acids

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Vergara, S.J. [Corrosion and Protection Centre, School of Materials, The University of Manchester, P.O. Box 88, Manchester M60 1QD (United Kingdom)], E-mail: s.garcia-vergara@manchester.ac.uk; Skeldon, P.; Thompson, G.E. [Corrosion and Protection Centre, School of Materials, The University of Manchester, P.O. Box 88, Manchester M60 1QD (United Kingdom); Habakaki, H. [Graduate School of Engineering, Hokkaido University, N13-W8, Sapporo 060-8628 (Japan)

    2007-12-30

    Using a tungsten-containing layer, incorporated into sputtering-deposited aluminium, as a tracer, the growth of porous anodic films in malonic and oxalic acid electrolytes has been investigated using transmission electron microscopy, Rutherford backscattering spectroscopy and nuclear reaction analysis. Comparisons were also made with films formed in phosphoric acid electrolyte, which have been studied previously. The findings reveal a distortion of the tracer layer within the barrier region of the porous films, evident as a lagging of the tracer beneath the pores relative to that in the adjacent cell wall region. Further, the films are significantly thicker than the layer of metal consumed during anodizing and display smooth-sided pores. The anodizing behaviours are consistent with a major role for field-assisted flow of film material within the barrier layer in the development of the pores.

  8. Na2Ti6O13 thin films as anode for thin film sodium ion batteries

    Science.gov (United States)

    Rambabu, A.; Kishore, B.; Munichandraiah, N.; Krupanidhi, S. B.; Barpanda, P.

    2017-05-01

    The pulsed laser deposition was employed to produce Na2Ti6O13 (NTO) thin films, which were applied as an anode material for Sodium-Ion batteries (SIBs). X-ray diffraction made it clear that the film is crystalline in single phase. Morphology and elemental composition studies were done using FESEM. Grain size and surface roughness was measured from atomic force microscopy. The electrochemical measurements were performed at 0.5 - 3V range and it exhibited the initial discharge capacity was 49.7 µAh/μm-cm2 with coulombic efficiency 69.8%.

  9. Preparation and Properties of Doped Lanthanum Gallate Film on a Ni/SDC Porous Anode Support

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A 65.8-μm dense doped lanthanum gallate La0.8Sr0.2Ga0.85Mg0.15O2.825 (LSGM)film was prepared on a porous Ni/SDC(samarium doped ceria, Ce0.8Sm0.2O1.9) anode support by colloid suspension deposition with incomplete crystallization LSGM powder as a starting material. The phase composition and micromorphology of the LSGM film were characterized by X-ray diffraction and scanning electron microscopy. The electrical properties of the LSGM film and the performances of the LSGM film solid oxide fuel cell were also analyzed. The results show that both the dense LSGM film on the porous anode support, and the required phase composition of the LSGM film were obtained simultaneously by sintering at 1400℃ for 6 h. The adhesion between the LSGM film and the porous anode support is very strong. The electrical conductivities of the LSGM film on the porous anode support are 0. 113 and 0. 173 S/cm at 800and 850 ℃, respectively. The maximum output power density of the LSGM film cell is 177 mW/cm2 at 700 ℃.

  10. Porous and mesh alumina formed by anodization of high purity aluminum films at low anodizing voltage

    Energy Technology Data Exchange (ETDEWEB)

    Abd-Elnaiem, Alaa M., E-mail: alaa.abd-elnaiem@science.au.edu.eg [KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Mebed, A.M. [Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Department of Physics, Faculty of Science, Al-Jouf University, Sakaka 2014 (Saudi Arabia); El-Said, Waleed Ahmed [Department of Chemistry, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Abdel-Rahim, M.A. [Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt)

    2014-11-03

    Electrochemical oxidation of high-purity aluminum (Al) films under low anodizing voltages (1–10) V has been conducted to obtain anodic aluminum oxide (AAO) with ultra-small pore size and inter-pore distance. Different structures of AAO have been obtained e.g. nanoporous and mesh structures. Highly regular pore arrays with small pore size and inter-pore distance have been formed in oxalic or sulfuric acids at different temperatures (22–50 °C). It is found that the pore diameter, inter-pore distance and the barrier layer thickness are independent of the anodizing parameters, which is very different from the rules of general AAO fabrication. The brand formation mechanism has been revealed by the scanning electron microscope study. Regular nanopores are formed under 10 V at the beginning of the anodization and then serve as a template layer dominating the formation of ultra-small nanopores. Anodization that is performed at voltages less than 5 V leads to mesh structured alumina. In addition, we have introduced a simple one-pot synthesis method to develop thin walls of oxide containing lithium (Li) ions that could be used for battery application based on anodization of Al films in a supersaturated mixture of lithium phosphate and phosphoric acid as matrix for Li-composite electrolyte. - Highlights: • We develop anodic aluminum oxide (AAO) with small pore size and inter-pore distance. • Applying low anodizing voltages onto aluminum film leads to form mesh structures. • The value of anodizing voltage (1–10 V) has no effect on pore size or inter-pore distance. • Applying anodizing voltage less than 5 V leads to mesh structured AAO. • AAO can be used as a matrix for Li-composite electrolytes.

  11. Fabrication of alumina films with laminated structures by ac anodization

    Directory of Open Access Journals (Sweden)

    Hiroyo Segawa

    2014-01-01

    Full Text Available Anodization techniques by alternating current (ac are introduced in this review. By using ac anodization, laminated alumina films are fabricated. Different types of alumina films consisting of 50–200 nm layers were obtained by varying both the ac power supply and the electrolyte. The total film thickness increased with an increase in the total charge transferred. The thickness of the individual layers increased with the ac voltage; however, the anodization time had little effect on the film thickness. The laminated alumina films resembled the nacre structure of shells, and the different morphologies exhibited by bivalves and spiral shells could be replicated by controlling the rate of increase of the applied potentials.

  12. Electrochemical Evaluation of Thin-Film Li-Si Anodes Prepared by Plasma Spraying

    Energy Technology Data Exchange (ETDEWEB)

    GUIDOTTI,RONALD A.; REINHARDT,FREDERICK W.; SCHARRER,GREGORY L.

    1999-09-08

    Thin-film electrodes of a plasma-sprayed Li-Si alloy were evaluated for use as anodes in high-temperature thermally activated (thermal) batteries. These anodes were prepared using 44% Li/56% Si (w/w) material as feed material in a special plasma-spray apparatus under helium or hydrogen, to protect this air- and moisture-sensitive material during deposition. Anodes were tested in single cells using conventional pressed-powder separators and lithiated pyrite cathodes at temperatures of 400 to 550 C at several different current densities. A limited number of 5-cell battery tests were also conducted. The data for the plasma-sprayed anodes was compared to that for conventional pressed-powder anodes. The performance of the plasma-sprayed anodes was inferior to that of conventional pressed-powder anodes, in that the cell emfs were lower (due to the lack of formation of the desired alloy phases) and the small porosity of these materials severely limited their rate capability. Consequently, plasma-sprayed Li-Si anodes would not be practical for use in thermal batteries.

  13. The anodizing behavior of aluminum in malonic acid solution and morphology of the anodic films

    Science.gov (United States)

    Ren, Jianjun; Zuo, Yu

    2012-11-01

    The anodizing behavior of aluminum in malonic acid solution and morphology of the anodic films were studied. The voltage-time response for galvanostatic anodization of aluminum in malonic acid solution exhibits a conventional three-stage feature but the formation voltage is much higher. With the increase of electrolyte concentration, the electrolyte viscosity increases simultaneously and the high viscosity decreases the film growth rate. With the concentration increase of the malonic acid electrolyte, the critical current density that initiates local "burning" on the sample surface decreases. For malonic acid anodization, the field-assisted dissolution on the oxide surface is relatively weak and the nucleation of pores is more difficult, which results in greater barrier layer thickness and larger cell dimension. The embryo of the porous structure of anodic film has been created within the linear region of the first transient stage, and the definite porous structure has been established before the end of the first transient stage. The self-ordering behavior of the porous film is influenced by the electrolyte concentration, film thickness and the applied current density. Great current density not only improves the cell arrangement order but also brings about larger cell dimension.

  14. Pulsed laser deposited Si on multilayer graphene as anode material for lithium ion batteries

    Directory of Open Access Journals (Sweden)

    Gouri Radhakrishnan

    2013-12-01

    Full Text Available Pulsed laser deposition and chemical vapor deposition were used to deposit very thin silicon on multilayer graphene (MLG on a nickel foam substrate for application as an anode material for lithium ion batteries. The as-grown material was directly fabricated into an anode without a binder, and tested in a half-cell configuration. Even under stressful voltage limits that accelerate degradation, the Si-MLG films displayed higher stability than Si-only electrodes. Post-cycling images of the anodes reveal the differences between the two material systems and emphasize the role of the graphene layers in improving adhesion and electrochemical stability of the Si.

  15. Optical properties of porous anodic alumina embedded Cu nanocomposite films

    Science.gov (United States)

    Liu, Huiyuan; Sun, Huiyuan; Liu, Lihu; Hou, Xue; Jia, Xiaoxuan

    2015-06-01

    Porous anodic alumina embedded Cu with iridescent colors were fabricated in copper sulfate electrolyte. The films display highly saturated colors after being synthesized by an ac electrodeposition method. Tunable color in the films is obtained by adjusting anodization time, and can be adjusted across the entire visible range. Theoretical results of the changes in the structural color according to the Bragg-Snell formula are consistent with the experimental results. The films could be used in many areas including decoration, display and multifunctional anti-counterfeiting applications.

  16. Tunable structural color of anodic tantalum oxide films

    Institute of Scientific and Technical Information of China (English)

    Sheng Cui-Cui; Cai Yun-Yu; Dai En-Mei; Liang Chang-Hao

    2012-01-01

    Tantalum (Ta) oxide films with tunable structural color were fabricated easily using anodic oxidation.The structure,components,and surface valence states of the oxide filns were investigated by using gazing incidence X-ray diffractometry,X-ray photoelectron microscopy,and surface analytical techniques.Their thickness and optical properties were studied by using spectroscopic ellipsometry and total reflectance spectrum.Color was accurately defined using L*a*b* scale.The thickness of compact Ta2O5 films was linearly dependent on anodizing voltage.The film color was tunable by adjusting the anodic voltage.The difference in color appearance resulted from the interference behavior between the interfaces of air-oxide and oxide-metal.

  17. Surface of Alumina Films after Prolonged Breakdowns in Galvanostatic Anodization

    Directory of Open Access Journals (Sweden)

    Christian Girginov

    2011-01-01

    Full Text Available Breakdown phenomena are investigated at continuous isothermal (20∘C and galvanostatic (0.2–5 mA cm−2 anodizing of aluminum in ammonium salicylate in dimethylformamide (1 M AS/DMF electrolyte. From the kinetic (-curves, the breakdown voltage ( values are estimated, as well as the frequency and amplitude of oscillations of formation voltage ( at different current densities. The surface of the aluminum specimens was studied using atomic force microscopy (AFM. Data on topography and surface roughness parameters of the electrode after electric breakdowns are obtained as a function of anodization time. The electrode surface of anodic films, formed with different current densities until the same charge density has passed (2.5 C cm−2, was assessed. Results are discussed on the basis of perceptions of avalanche mechanism of the breakdown phenomena, due to the injection of electrons and their multiplication in the volume of the film.

  18. Hydrogenated amorphous silicon thin film anode for proton conducting batteries

    Science.gov (United States)

    Meng, Tiejun; Young, Kwo; Beglau, David; Yan, Shuli; Zeng, Peng; Cheng, Mark Ming-Cheng

    2016-01-01

    Hydrogenated amorphous Si (a-Si:H) thin films deposited by chemical vapor deposition were used as anode in a non-conventional nickel metal hydride battery using a proton-conducting ionic liquid based non-aqueous electrolyte instead of alkaline solution for the first time, which showed a high specific discharge capacity of 1418 mAh g-1 for the 38th cycle and retained 707 mAh g-1 after 500 cycles. A maximum discharge capacity of 3635 mAh g-1 was obtained at a lower discharge rate, 510 mA g-1. This electrochemical discharge capacity is equivalent to about 3.8 hydrogen atoms stored in each silicon atom. Cyclic voltammogram showed an improved stability 300 mV below the hydrogen evolution potential. Both Raman spectroscopy and Fourier transform infrared spectroscopy studies showed no difference to the pre-existing covalent Si-H bond after electrochemical cycling and charging, indicating a non-covalent nature of the Si-H bonding contributing to the reversible hydrogen storage of the current material. Another a-Si:H thin film was prepared by an rf-sputtering deposition followed by an ex-situ hydrogenation, which showed a discharge capacity of 2377 mAh g-1.

  19. Real time measurement of Al anode degradation in thin film batteries

    Science.gov (United States)

    Leite, Marina; Ruzmetov, Dmitry; Li, Zhipeng; Bendersky, Leonid; Talin, A. Alec

    2013-03-01

    Li-ion battery (LIB) anodes that alloy with Li, including Si, Ge, Sn, and Al have specific capacities that significantly exceed that of carbon-based intercalation anodes. However, the large volume expansion and contraction that accompany charging and discharging processes lead to large mechanical stresses that ultimately lead to loss of capacity and failure of the anodes. To better understand the failure mechanism, we cycle a thin film LIB with an Al anode in a scanning electron microscope to measure in real time the nucleation and growth of a highly strained (-44%) Al-Li alloy. We use galvanostatic charging and discharging to control the rate of Li diffusion into the Al anode, and by collecting a series of SEM images in small time intervals we are able to directly correlate the nucleation events of Li-Al with specific peaks in the measured voltage. Based on these observations and ex situ transmission electron microscopy we develop a semi-quantitative description for the mechanism of Al anode degradation that could be extended to other alloy anode materials.

  20. New Anode Material for Rechargeable Li-ION Cells

    Science.gov (United States)

    Huang, C. -K.; Smart, M.; Halpert, G.; Surampudi, S.; Wolfenstine, J.

    1995-01-01

    Carbon materials, such as graphite, cokes, pitch and PAN fibers, are being evaluated in lithium batteries as alternate anode materials with some degree of success. There is an effort to look for other non-carbon anode materials which have larger Li capacity, higher rate capability, smaller first charge capacity loss and better mechanical stability during cycling. A Li-Mg-Si material is evaluated.

  1. Characterizations of SWNT films to obtain organic optoelectronic device anodes

    Energy Technology Data Exchange (ETDEWEB)

    Antony, R.; Ratier, B. [XLIM UMR 6172, Universite de Limoges, CNRS, 123 av. Albert Thomas, 87060 Limoges Cedex (France); Colas, M. [SPCTS, UMR CNRS6638, Faculte des Sci. et Tech., 123, av. Albert Thomas, 87060 Limoges Cedex (France); Banoukepa, G.R. de

    2010-04-15

    Organic devices such as solar cells or light emitting diodes (OLEDs) have been intensively studied for the last decade, and have now the potential to reach the market for various applications. Nevertheless, various reports have shown that devices based on Indium Tin Oxide anode present a reduced efficiency due to indium diffusion into organic active layers. In this context, our work focus on the development and the characterization of alternative anodes based on Single Walled Carbon Nanotube (SWNT) Films. In particular, this work is devoted to the morphology and charge transport properties of carbon nanotube thin layers. SWNT films were prepared on glass substrates using the vacuum filtration method reported by Wu et al. As a second step, the films were dipped in a nitric acid and subsequently dried in order to reduce their sheet resistances. Raman spectroscopy is then used to chemically map the film surface, and allow us to assess the homogeneity of the achieved films. Finally, optical and electrical characterizations (measurements of the sheet resistance and optical transmission) provide evidence of a correlation between the quality of the surface and the nature of charge transport occurring in the prepared SWNT films (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Hollow Nanostructured Anode Materials for Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Liu Jun

    2010-01-01

    Full Text Available Abstract Hollow nanostructured anode materials lie at the heart of research relating to Li-ion batteries, which require high capacity, high rate capability, and high safety. The higher capacity and higher rate capability for hollow nanostructured anode materials than that for the bulk counterparts can be attributed to their higher surface area, shorter path length for Li+ transport, and more freedom for volume change, which can reduce the overpotential and allow better reaction kinetics at the electrode surface. In this article, we review recent research activities on hollow nanostructured anode materials for Li-ion batteries, including carbon materials, metals, metal oxides, and their hybrid materials. The major goal of this review is to highlight some recent progresses in using these hollow nanomaterials as anode materials to develop Li-ion batteries with high capacity, high rate capability, and excellent cycling stability.

  3. Effect of surface treatments on anodic oxide film growth and electrochemical properties of tantalum used for biomedical applications.

    Science.gov (United States)

    Silva, R A; Silva, I P; Rondot, B

    2006-07-01

    Self-expandable nitinol (nickel-titanium) alloys and 316L stainless steel are the most commonly used materials in the production of coronary stents. However, tantalum (Ta) has already been used to make stents for endovascular surgery and may constitute an alternative to other materials because of its better electrochemical performance, namely its higher corrosion resistance, as well as its radio-opacity. The characterization of wet polished, chemically polished, wet polished anodized, and chemically polished anodized Ta electrodes has been performed in a 0.15 M NaCl solution (simulated body fluid) using Ucorr = f(t) measurements, anodic polarizations, capacity measurements, anodic oxidations, and atomic force microscopy (AFM) imaging. Anodic polarization curves have shown that the abnormal current density peak with a maximum value around 1.65 V (critical applied potential, Uc) disappeared for the anodized electrodes indicating a probable relationship between the surface states and the film growth. These results are confirmed by capacity measurements. The behavior of wet polished and chemically polished electrodes during anodic oxidations seemingly indicated that for these particular treatments the film growth is different. The AFM images and roughness measurements have shown that chemical polishing produced smoother electrodes, a fact probably related to the differences in film growth.

  4. Preparation of titanium dioxide films on etched aluminum foil by vacuum infiltration and anodizing

    Science.gov (United States)

    Xiang, Lian; Park, Sang-Shik

    2016-12-01

    Al2O3-TiO2 (Al-Ti) composite oxide films are a promising dielectric material for future use in capacitors. In this study, TiO2 films were prepared on etched Al foils by vacuum infiltration. TiO2 films prepared using a sol-gel process were annealed at various temperatures (450, 500, and 550 °C) for different time durations (10, 30, and 60 min) for 4 cycles, and then anodized at 100 V. The specimens were characterized using X-ray diffraction, field emission scanning electron microscopy, and field emission transmission electron microscopy. The results show that the tunnels of the specimens feature a multi-layer structure consisting of an Al2O3 outer layer, an Al-Ti composite oxide middle layer, and an aluminum hydrate inner layer. The electrical properties of the specimens, such as the withstanding voltage and specific capacitance, were also measured. Compared to specimens without TiO2 coating, the specific capacitances of the TiO2-coated specimens are increased. The specific capacitance of the anode Al foil with TiO2 coating increased by 42% compared to that of a specimen without TiO2 coating when annealed at 550 °C for 10 min. These composite oxide films could enhance the specific capacitance of anode Al foils used in dielectric materials.

  5. Preparation of Porous Alumina Film on Aluminum Substrate by Anodization in Oxalic Acid

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Self-ordering of the cell arrangement of the anodic porous alumina was prepared in oxalic acid solution at a constant potential of 40V and at a temperature of 20°C. The honeycomb structure made by one step anodization method and two step anodization method is different.Pores in the alumina film prepared by two step anodization method were more ordered than those by one step anodization method.

  6. Nanocomposite anode materials for sodium-ion batteries

    Science.gov (United States)

    Manthiram, Arumugam; Kim Il, Tae; Allcorn, Eric

    2016-06-14

    The disclosure relates to an anode material for a sodium-ion battery having the general formula AO.sub.x--C or AC.sub.x--C, where A is aluminum (Al), magnesium (Mg), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), zirconium (Zr), molybdenum (Mo), tungsten (W), niobium (Nb), tantalum (Ta), silicon (Si), or any combinations thereof. The anode material also contains an electrochemically active nanoparticles within the matrix. The nanoparticle may react with sodium ion (Na.sup.+) when placed in the anode of a sodium-ion battery. In more specific embodiments, the anode material may have the general formula M.sub.ySb-M'O.sub.x--C, Sb-MO.sub.x--C, M.sub.ySn-M'C.sub.x--C, or Sn-MC.sub.x--C. The disclosure also relates to rechargeable sodium-ion batteries containing these materials and methods of making these materials.

  7. Ordered Nanomaterials Thin Films via Supported Anodized Alumina Templates

    Directory of Open Access Journals (Sweden)

    Mohammed eES-SOUNI

    2014-10-01

    Full Text Available Supported anodized alumina template films with highly ordered porosity are best suited for fabricating large area ordered nanostructures with tunable dimensions and aspect ratios. In this paper we first discuss important issues for the generation of such templates, including required properties of the Al/Ti/Au/Ti thin film heterostructure on a substrate for high quality templates. We then show examples of anisotropic nanostructure films consisting of noble metals using these templates, discuss briefly their optical properties and their applications to molecular detection using surface enhanced Raman spectroscopy. Finally we briefly address the possibility to make nanocomposite films, exemplary shown on a plasmonic-thermochromic nanocomposite of VO2-capped Au-nanorods.

  8. Anode properties of silicon-rich amorphous silicon suboxide films in all-solid-state lithium batteries

    Science.gov (United States)

    Miyazaki, Reona; Ohta, Narumi; Ohnishi, Tsuyoshi; Takada, Kazunori

    2016-10-01

    This paper reports the effects of introducing oxygen into amorphous silicon films on their anode properties in all-solid-state lithium batteries. Although poor cycling performance is a critical issue in silicon anodes, it has been effectively improved by introducing even a small amount of oxygen, that is, even in Si-rich amorphous silicon suboxide (a-SiOx) films. Because of the small amount of oxygen in the films, high cycling performance has been achieved without lowering the capacity and power density: an a-Si film delivers discharge capacity of 2500 mAh g-1 under high discharge current density of 10 mA cm-2 (35 C). These results demonstrate that a-SiOx is a promising candidate for high-capacity anode materials in solid-state batteries.

  9. Porous anodic film formation on an Al-3.5wt% Cu alloy

    Energy Technology Data Exchange (ETDEWEB)

    Paez, M. A.; Skeldon, P.; Thompson, G. E.; Saez, M.; Bustos, O.; Monsalve, A.

    2003-07-01

    The morphological development of porous anodic films in the initial stages is examined during anodizing an Al-3,5 wt% Cu alloy in phosphoric acid. Using transmission electron microscopy a sequence of ultramicrotomed anodic sections reveals the dynamic evolution of numerous features in the thickening film in the initial stages of anodizing. The morphological changes in the anodic oxides in the initial stages of its formation appears related to the formation of bubbles during film growth. From Rutherford backscattering spectroscopy (RBS) analysis of the film, the formation of the bubbles is associated with the enrichment of copper in the alloy due to growth of the anodic oxide. On the other hand, during constant current anodizing of Al-Cu in phosphoric acid, the current efficiency is considerably less than that for anodizing super pure aluminium under similar conditions. >From the contrasting results between the charge consumed calculated from RBS and the real charge consumed during anodizing, oxygen gas bubbles generation and copper oxidation seem to be of less importance on the low efficiency for film formation. It is apparent that the main cause of losing efficiency for film growth on Al-Cu is associated with generation of oxygen ar residual second phase, with the development of stresses in the film and, the consequence of these effects on film cracking during film growth. (Author) 10 refs.

  10. Light-Weight Free-Standing Carbon Nanotube-Silicon Films for Anodes of Lithium Ion Batteries

    KAUST Repository

    Cui, Li-Feng

    2010-07-27

    Silicon is an attractive alloy-type anode material because of its highest known capacity (4200 mAh/g). However, lithium insertion into and extraction from silicon are accompanied by a huge volume change, up to 300%, which induces a strong strain on silicon and causes pulverization and rapid capacity fading due to the loss of the electrical contact between part of silicon and current collector. Si nanostructures such as nanowires, which are chemically and electrically bonded to the current collector, can overcome the pulverization problem, however, the heavy metal current collectors in these systems are larger in weight than Si active material. Herein we report a novel anode structure free of heavy metal current collectors by integrating a flexible, conductive carbon nanotube (CNT) network into a Si anode. The composite film is free-standing and has a structure similar to the steel bar reinforced concrete, where the infiltrated CNT network functions as both mechanical support and electrical conductor and Si as a high capacity anode material for Li-ion battery. Such free-standing film has a low sheet resistance of ∼30 Ohm/sq. It shows a high specific charge storage capacity (∼2000 mAh/g) and a good cycling life, superior to pure sputtered-on silicon films with similar thicknesses. Scanning electron micrographs show that Si is still connected by the CNT network even when small breaking or cracks appear in the film after cycling. The film can also "ripple up" to release the strain of a large volume change during lithium intercalation. The conductive composite film can function as both anode active material and current collector. It offers ∼10 times improvement in specific capacity compared with widely used graphite/copper anode sheets. © 2010 American Chemical Society.

  11. 化学镀制备锡-锌-镍合金锂离子电池阳极材料%Electroless Deposition of Sn-Zn-Ni Alloy Film for Anodic Materials of Lithium Ion Batteries

    Institute of Scientific and Technical Information of China (English)

    李峰; 张世超

    2012-01-01

    Sn-Zn-Ni ternary alloy film was prepared on copper foil and foam copper respectively by a modified electroless plating process* which used both of sodium borohydride and sodium hypophosphite as reducing agents and was combined with alkaline tin disproportionating reaction. X-ray diffraction (XRD) . Scanning electron microscopy (SEM) , and energy dispersive X-ray spectrometry (EDS) were used to characterize the phases, morphology and composition of the films respectively on both copper foil and copper foam. The EDS results show that the elements,such as Sn, Zn and Ni can be found in the coating. By optimizing, the mass fraction of zinc in the coating can reach 25 %. A three-dimensional porous foam copper used as substrate to deposit Sn-Zn-Ni ternary alloy film, and then the film is coated with glucose-derived carbon-rich polysaccharide by a hydrothermal approach. When it is used as anode materials in lithium ion batteries, the reversible lithium storage capacity of more than 400 mA ? H " g"1 can be after 10 cycles.%应用经过改进的化学镀工艺,即:采用硼氢化钠、次磷酸钠同时作为还原剂,结合锡的碱性歧化反应,分别在铜箔及泡沫铜上制备Sn-Zn-Ni三元合金镀层.用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、X射线能量衍射谱(EDS)分析镀层的结构与组成.结果表明:镀层中含有锡、锌、镍三种元素;优化沉积条件,镀层中锌的质量分数可达25%.采用三维多孔泡沫铜为基体,制备化学镀层并对其进行水热葡萄糖碳包覆处理.作为锂离子电池阳极材料,充放电循环10周,放电容量仍可保持在400mA·h·g-1以上.

  12. Preparation and analysis of anodic aluminum oxide films with continuously tunable interpore distances

    Science.gov (United States)

    Qin, Xiufang; Zhang, Jinqiong; Meng, Xiaojuan; Deng, Chenhua; Zhang, Lifang; Ding, Guqiao; Zeng, Hao; Xu, Xiaohong

    2015-02-01

    Nanoporous anodic aluminum oxides are often used as templates for preparation of nanostructures such as nanodot, nanowire and nanotube arrays. The interpore distance of anodic aluminum oxide is the most important parameter in controlling the periodicity of these nanostructures. Herein we demonstrate a simple and yet powerful method to fabricate ordered anodic aluminum oxides with continuously tunable interpore distances. By using mixed solution of citric and oxalic acids with different molar ratio, the range of anodizing voltages within which self-ordered films can be formed were extended to between 40 and 300 V, resulting in the interpore distances change from 100 to 750 nm. Our work realized very broad range of interpore distances in a continuously tunable fashion and the experiment processes are easily controllable and reproducible. The dependence of the interpore distances on acid ratios in mixed solutions was discussed through analysis of anodizing current and it was found that the effective dissociation constant of the mixed acids is of great importance. The interpore distances achieved are comparable to wavelengths ranging from UV to near IR, and may have potential applications in optical meta-materials for photovoltaics and optical sensing.

  13. Oxide anode materials for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fergus, Jeffrey W. [Auburn University, Materials Research and Education Center, 275 Wilmore Laboratories, Auburn, AL 36849 (United States)

    2006-07-15

    A major advantage of solid oxide fuel cells (SOFCs) over polymer electrolyte membrane (PEM) fuel cells is their tolerance for the type and purity of fuel. This fuel flexibility is due in large part to the high operating temperature of SOFCs, but also relies on the selection and development of appropriate materials - particularly for the anode where the fuel reaction occurs. This paper reviews the oxide materials being investigated as alternatives to the most commonly used nickel-YSZ cermet anodes for SOFCs. The majority of these oxides form the perovskite structure, which provides good flexibility in doping for control of the transport properties. However, oxides that form other crystal structures, such as the cubic fluorite structure, have also shown promise for use as SOFC anodes. In this paper, oxides are compared primarily in terms of their transport properties, but other properties relative to SOFC anode performance are also discussed. (author)

  14. Anodic materials for the electrolysis of water. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fiori, G.; Mari, C.M.; Perra, B.; Vago, L.; Vitali, P.

    1980-01-01

    Research was conducted in two areas: preparation and characterization of various catalytic materials, similar to NiLa/sub 2/O/sub 4/, in order to verify the possibility of improving the catalytic activity; and optimization of the catalytic film deposition conditions on a cheap substrate and tests at high temperature (110 to 120/sup 0/C) and high current densities (1 A/cm/sup 2/). The modified catalytic materials can be classified in three different groups: NiLa/sub 2/O/sub 4/ mixed oxides doped with different low quantities of cations of various valencies (Li/sup +/, Mg/sup 2 +/, Fe/sup 3 +/); mixed oxides in which Ni has been replaced totally or partially with Co; and NiLa/sub 2/O/sub 3/ mixed oxides in which some sulfur has been substituted for reticular oxygen. The best electrode tested is the mixed Ni-Co non-stoichiometric oxide deposited on Ni. This electrode at 110/sup 0/C and 1 A/cm/sup 2/ shows an E/sub rhe/ potential lower than 1.45 v after more than 400 hr of uninterrupted work as anode in the water decomposition reaction.

  15. Structural features of anodic oxide films formed on aluminum substrate coated with self-assembled microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Asoh, Hidetaka [Department of Applied Chemistry, Faculty of Engineering, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015 (Japan)], E-mail: asoh@cc.kogakuin.ac.jp; Uchibori, Kota; Ono, Sachiko [Department of Applied Chemistry, Faculty of Engineering, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015 (Japan)

    2009-07-15

    The structural features of anodic oxide films formed on an aluminum substrate coated with self-assembled microspheres were investigated by scanning electron microscopy and atomic force microscopy. In the first anodization in neutral solution, the growth of a barrier-type film was partially suppressed in the contact area between the spheres and the underlying aluminum substrate, resulting in the formation of ordered dimple arrays in an anodic oxide film. After the subsequent second anodization in acid solution at a voltage lower than that of the first anodization, nanopores were generated only within each dimple. The nanoporous region could be removed selectively by post-chemical etching using the difference in structural dimensions between the porous region and the surrounding barrier region. The mechanism of anodic oxide growth on the aluminum substrate coated with microspheres through multistep anodization is discussed.

  16. In Situ Carbonized Cellulose-Based Hybrid Film as Flexible Paper Anode for Lithium-Ion Batteries.

    Science.gov (United States)

    Cao, Shaomei; Feng, Xin; Song, Yuanyuan; Liu, Hongjiang; Miao, Miao; Fang, Jianhui; Shi, Liyi

    2016-01-20

    Flexible free-standing carbonized cellulose-based hybrid film is integrately designed and served both as paper anode and as lightweight current collector for lithium-ion batteries. The well-supported heterogeneous nanoarchitecture is constructed from Li4Ti5O12 (LTO), carbonized cellulose nanofiber (C-CNF) and carbon nanotubes (CNTs) using by a pressured extrusion papermaking method followed by in situ carbonization under argon atmospheres. The in situ carbonization of CNF/CNT hybrid film immobilized with uniform-dispersed LTO results in a dramatic improvement in the electrical conductivity and specific surface area, so that the carbonized paper anode exhibits extraordinary rate and cycling performance compared to the paper anode without carbonization. The flexible, lightweight, single-layer cellulose-based hybrid films after carbonization can be utilized as promising electrode materials for high-performance, low-cost, and environmentally friendly lithium-ion batteries.

  17. Properties of anodic oxides grown on a hafnium–tantalum–titanium thin film library

    Directory of Open Access Journals (Sweden)

    Andrei Ionut Mardare

    2014-01-01

    Full Text Available A ternary thin film combinatorial materials library of the valve metal system Hf–Ta–Ti obtained by co-sputtering was studied. The microstructural and crystallographic analysis of the obtained compositions revealed a crystalline and textured surface, with the exception of compositions with Ta concentration above 48 at.% which are amorphous and show a flat surface. Electrochemical anodization of the composition spread thin films was used for analysing the growth of the mixed surface oxides. Oxide formation factors, obtained from the potentiodynamic anodization curves, as well as the dielectric constants and electrical resistances, obtained from electrochemical impedance spectroscopy, were mapped along two dimensions of the library using a scanning droplet cell microscope. The semiconducting properties of the anodic oxides were mapped using Mott–Schottky analysis. The degree of oxide mixing was analysed qualitatively using x-ray photoelectron spectroscopy depth profiling. A quantitative analysis of the surface oxides was performed and correlated to the as-deposited metal thin film compositions. In the concurrent transport of the three metal cations during oxide growth a clear speed order of Ti > Hf > Ta was proven.

  18. Silicon nitride coated silicon thin film on three dimensions current collector for lithium ion battery anode

    Science.gov (United States)

    Wu, Cheng-Yu; Chang, Chun-Chi; Duh, Jenq-Gong

    2016-09-01

    Silicon nitride coated silicon (N-Si) has been synthesized by two-step DC sputtering on Cu Micro-cone arrays (CMAs) at ambient temperature. The electrochemical properties of N-Si anodes with various thickness of nitride layer are investigated. From the potential window of 1.2 V-0.05 V, high rate charge-discharge and long cycle test have been executed to investigate the electrochemical performances of various N-Si coated Si-based lithium ion batteries anode materials. Higher specific capacity can be obtained after 200 cycles. The cycling stability is enhanced via thinner nitride layer coating as silicon nitride films are converted to Li3N with covered Si thin films. These N-Si anodes can be cycled under high rates up to 10 C due to low charge transfer resistance resulted from silicon nitride films. This indicates that the combination of silicon nitride and silicon can effectively endure high current and thus enhance the cycling stability. It is expected that N-Si is a potential candidate for batteries that can work effectively under high power.

  19. Nanoconfined phosphorus film coating on interconnected carbon nanotubes as ultrastable anodes for lithium ion batteries

    Science.gov (United States)

    Xu, Zhiwei; Zeng, Yan; Wang, Liyuan; Li, Nan; Chen, Cheng; Li, Cuiyu; Li, Jing; Lv, Hanming; Kuang, Liyun; Tian, Xu

    2017-07-01

    Elemental phosphorus (P) is extensively explored as promising anode candidates due to its abundance, low-cost and high theoretical specific capacity. However, it is of great challenge for P-based materials as practical high-energy-density and long-cycling anodes for its large volume expansion and low conductibility. Here, we significantly improve both cycling and rate performance of red P by cladding the nanoconfined P film on interconnected multi-walled carbon nanotube networks (P-MWCNTs composite) via facile wet ball-milling. The red P-MWCNTs anode presents a superior high reversible capacity of 1396.6 mAh g-1 on the basis of P-MWCNTs composite weight at 50 mA g-1 with capacity retention reaching at ∼90% over 50 cycles. Even at 1000 mA g-1, it still maintains remarkable specific reversible capacity of 934.0 mAh g-1. This markedly enhanced performance is ascribed to synergistic advantages of this unique structure: Intimate contacts between nanosized red P and entangled MWCNTs not only shorten the transmission routes of ions through MWCNTs toward red P, but also motivate the access with electrolyte to open structures of P film. Besides, the confined nanosized P film moderate volume expansions effectively and the entangled MWCNTs networks acted as conductive channels activate high ionic/electronic conductivity of the whole electrodes.

  20. Na-Ion Battery Anodes: Materials and Electrochemistry.

    Science.gov (United States)

    Luo, Wei; Shen, Fei; Bommier, Clement; Zhu, Hongli; Ji, Xiulei; Hu, Liangbing

    2016-02-16

    The intermittent nature of renewable energy sources, such as solar and wind, calls for sustainable electrical energy storage (EES) technologies for stationary applications. Li will be simply too rare for Li-ion batteries (LIBs) to be used for large-scale storage purposes. In contrast, Na-ion batteries (NIBs) are highly promising to meet the demand of grid-level storage because Na is truly earth abundant and ubiquitous around the globe. Furthermore, NIBs share a similar rocking-chair operation mechanism with LIBs, which potentially provides high reversibility and long cycling life. It would be most efficient to transfer knowledge learned on LIBs during the last three decades to the development of NIBs. Following this logic, rapid progress has been made in NIB cathode materials, where layered metal oxides and polyanionic compounds exhibit encouraging results. On the anode side, pure graphite as the standard anode for LIBs can only form NaC64 in NIBs if solvent co-intercalation does not occur due to the unfavorable thermodynamics. In fact, it was the utilization of a carbon anode in LIBs that enabled the commercial successes. Anodes of metal-ion batteries determine key characteristics, such as safety and cycling life; thus, it is indispensable to identify suitable anode materials for NIBs. In this Account, we review recent development on anode materials for NIBs. Due to the limited space, we will mainly discuss carbon-based and alloy-based anodes and highlight progress made in our groups in this field. We first present what is known about the failure mechanism of graphite anode in NIBs. We then go on to discuss studies on hard carbon anodes, alloy-type anodes, and organic anodes. Especially, the multiple functions of natural cellulose that is used as a low-cost carbon precursor for mass production and as a soft substrate for tin anodes are highlighted. The strategies of minimizing the surface area of carbon anodes for improving the first-cycle Coulombic efficiency are

  1. Advanced Nanostructured Anode Materials for Sodium-Ion Batteries.

    Science.gov (United States)

    Wang, Qidi; Zhao, Chenglong; Lu, Yaxiang; Li, Yunming; Zheng, Yuheng; Qi, Yuruo; Rong, Xiaohui; Jiang, Liwei; Qi, Xinguo; Shao, Yuanjun; Pan, Du; Li, Baohua; Hu, Yong-Sheng; Chen, Liquan

    2017-09-19

    Sodium-ion batteries (NIBs), due to the advantages of low cost and relatively high safety, have attracted widespread attention all over the world, making them a promising candidate for large-scale energy storage systems. However, the inherent lower energy density to lithium-ion batteries is the issue that should be further investigated and optimized. Toward the grid-level energy storage applications, designing and discovering appropriate anode materials for NIBs are of great concern. Although many efforts on the improvements and innovations are achieved, several challenges still limit the current requirements of the large-scale application, including low energy/power densities, moderate cycle performance, and the low initial Coulombic efficiency. Advanced nanostructured strategies for anode materials can significantly improve ion or electron transport kinetic performance enhancing the electrochemical properties of battery systems. Herein, this Review intends to provide a comprehensive summary on the progress of nanostructured anode materials for NIBs, where representative examples and corresponding storage mechanisms are discussed. Meanwhile, the potential directions to obtain high-performance anode materials of NIBs are also proposed, which provide references for the further development of advanced anode materials for NIBs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Formation and dielectric properties of anodic oxide films on Zr–Al alloys

    OpenAIRE

    Koyama, Shun; Aoki, Yoshitaka; Nagata, Shinji; Habazaki, Hiroki

    2011-01-01

    Zr–Al alloys containing up to 26 at.% aluminum, prepared by magnetron sputtering, have been anodized in 0.1 mol dm−3 ammonium pentaborate electrolyte, and the structure and dielectric properties of the resultant anodic oxide films have been examined by grazing incidence X-ray diffraction, transmission electron microscopy, Rutherford backscattering spectroscopy, and AC impedance spectroscopy. The anodic oxide film formed on zirconium consists of monoclinic and tetragonal ZrO2 with the fo...

  3. FIB-SEM investigation of trapped intermetallic particles in anodic oxide films on AA1050 aluminium

    DEFF Research Database (Denmark)

    Jariyaboon, Manthana; Møller, Per; Dunin-Borkowski, Rafal E.

    2011-01-01

    -containing intermetallic particles incorporated into the anodic oxide films on industrially pure aluminium (AA1050, 99.5 per cent) has been investigated. AA1050 aluminium was anodized in a 100?ml/l sulphuric acid bath with an applied voltage of 14?V at 20°C ±2°C for 10 or 120?min. The anodic film subsequently was analyzed...

  4. Crystallography-Induced Correlations in Pore Ordering of Anodic Alumina Films

    NARCIS (Netherlands)

    Roslyakov, Ilya V.; Koshkodaev, Dmitry S.; Eliseev, Andrei A.; Hermida-Merino, Daniel; Petukhov, Andrei V.; Napolskii, Kirill S.

    2016-01-01

    A crystallographic approach to tailoring the morphology and ordering degree of the porous structure of alumina films obtained by anodization of single-crystalline aluminum is discussed. The examination of porous structure of anodic alumina films formed on low-index and vicinal planes of Al single cr

  5. Corrosion Behavior of Anodic Oxidized TiO2 Film in Seawater

    Institute of Scientific and Technical Information of China (English)

    WANG Min; WANG Wei; HE Benlin; SUN Mingliang; YIN Yansheng; LIU Lan; ZOU Wuyuan; XU Xuefei

    2010-01-01

    TiO2 films were formed on metallic titanium substrates by the anodic oxidation method in H2SO4 solution under the 80V D.C..Phase component and microstructure were characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM).Water contact angles on titanium oxide film surface were measured under both dark and sunlight illumination conditions.Corrosion tests were carried out in seawater under different illumination conditions by electrochemistry impedance spectrum(EIS)and polarization curves.The result showed that the TiO2 film prepared by the anodic oxidation method was anatase with a uniform structure and without obvious pores or cracks on its surface.The average water contact angle of the film was 116.4 ° in dark,in contrast to an angle of 42.7 ° under the UV illumination for 2 hours,which demonstrates good hydrophobic property.The anti-corrosion behavior of the TiO2 film was declining with the extended immersion time.Under dark conditions,however,the hydrophobic TiO2 film retarded the water infiltrating into the substrate.The impedance changed slowly and the corrosion current density was 2 orders of magnitude lower than that with the film illuminated by sunlight.All of those mentioned above indicate that the TiO2 film possesses much better performance under dark condition,and it can be applied as an engineering material under dark seawater environment.

  6. Fabrication of superhydrophobic niobium pentoxide thin films by anodization

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Bong-Yong [Future Convergence Ceramic Division, Korea Institute of Ceramic Engineering and Technology, Seoul 153-801 (Korea, Republic of); Jung, Eun-Hye [Future Convergence Ceramic Division, Korea Institute of Ceramic Engineering and Technology, Seoul 153-801 (Korea, Republic of); Department of Chemical Engineering, Inha University, Incheon 402-024 (Korea, Republic of); Kim, Jin-Ho, E-mail: jhkim@kicet.re.kr [Electronic and Optic Materials Division, Korea Institute of Ceramic Engineering and Technology, Seoul 153-801 (Korea, Republic of)

    2014-07-01

    We report a simple method to fabricate a niobium oxide film with a lotus-like micro–nano surface structure. Self-assembled niobium pentoxide (Nb{sub 2}O{sub 5}) films with superhydrophobic property were fabricated by an anodization and a hydrophobic treatment. This process has several advantages such as low cost, simplicity and easy coverage of a large area. The surface of fabricated Nb{sub 2}O{sub 5} film was changed from hydrophilic to superhydrophobic surface by a treatment using fluoroaldyltrimethoxysilane (FAS) solution. This value is considered to be the lowest surface free energy of any solid, based on the alignment of -CF{sub 3} groups on the surface. In particular, among FAS coated surfaces, the micro–nano complex cone structured Nb{sub 2}O{sub 5} film showed the highest water-repellent property with a static contact angle of ca. 162°. This study gives promising routes from biomimetic superhydrophobic surfaces.

  7. Carbon Cryogel Silicon Composite Anode Materials for Lithium Ion Batteries

    Science.gov (United States)

    Woodworth James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 10 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-4,9 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  8. Blue luminescence in porous anodic alumina films: the role of the oxalic impurities

    CERN Document Server

    Gao Tao; Zhang Li

    2003-01-01

    Porous anodic alumina (PAA) films with ordered nanopore arrays have been prepared by electrochemically anodizing aluminium in oxalic acid solutions, and the role of the oxalic impurities in the optical properties of PAA films has been discussed. Photoluminescence (PL) measurements show that the PAA films obtained have a blue PL band with a peak position at around 470 nm; the oxalic impurities, incorporated in the PAA films during the anodization processes and already existing in them, could be being transformed into PL centres and hence responsible for this PL emission.

  9. Photocatalytic activity of porous TiO2 films prepared by anodic oxidation

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; TAO Jie; WANG Tao; WANG Ling

    2007-01-01

    Anatase titanium dioxide is an active photocatalyst, however, it is difficult to be immobilized on the substrate.The crystalline TiO2 porous film was prepared directly on the surface of pure titanium by anodic oxidation. The film was then used for photocatalysis via the methyl orange degradation method. The effects of anodization voltage, pH value, TiO2 film area and degradation time on the photocatalyst were investigated respectively by UV-visible spectrum. It was indicated that the TiO2 film prepared by anodic oxidation at 140 V had the best photocatalysis capability and the degradation of methyl orange was accelerated with acid addition.

  10. Microstructural characterization of oxide film formed on NiTi by anodization in acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, F.T. [Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)]. E-mail: apaftche@polyu.edu.hk; Shi, P. [Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Department of Materials and Chemical Engineering, Liaoning Institute of Technology, Jinzhou, Liaoning (China); Pang, G.K.H. [Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Wong, M.H. [Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Man, H.C. [Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)

    2007-07-12

    NiTi was galvanostatically anodized in acetic acid aiming at forming an anodic film for improving corrosion resistance. While the corrosion behavior of anodized NiTi in Hanks' solution was reported elsewhere [P. Shi, F.T. Cheng, H.C. Man, Mater. Lett., submitted for publication], the present work reports the microstructural characterization of the anodic film formed. Bright-field image of the sample cross-section captured by transmission electron microscopy (TEM) revealed an oxide film of about 20 nm thick, which was smooth and free of defects. The surface roughness R {sub a} of the film, determined by atomic force microscopy (AFM), was about 1.45 nm. Analysis by X-ray photoelectron spectroscopy (XPS) along the depth of the anodic film indicated that the oxidation state of Ti varied from +4 (corresponding to TiO{sub 2}) at the surface to lower oxidation states (corresponding to Ti suboxides) beneath. A small amount of Ni in the metallic and oxidized states was also present. The Ni/Ti atomic ratio was about 0.04 at the surface of the anodic film, which was much lower than the corresponding value of 0.30 for the mechanically polished samples. Selected-area diffraction (SAD) patterns and high-resolution TEM image of the anodic film showed that the film was amorphous.

  11. Nanocomposite anode materials for sodium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Manthiram, Arumugam; Kim Il, Tae; Allcorn, Eric

    2016-06-14

    The disclosure relates to an anode material for a sodium-ion battery having the general formula AO.sub.x--C or AC.sub.x--C, where A is aluminum (Al), magnesium (Mg), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), zirconium (Zr), molybdenum (Mo), tungsten (W), niobium (Nb), tantalum (Ta), silicon (Si), or any combinations thereof. The anode material also contains an electrochemically active nanoparticles within the matrix. The nanoparticle may react with sodium ion (Na.sup.+) when placed in the anode of a sodium-ion battery. In more specific embodiments, the anode material may have the general formula M.sub.ySb-M'O.sub.x--C, Sb-MO.sub.x--C, M.sub.ySn-M'C.sub.x--C, or Sn-MC.sub.x--C. The disclosure also relates to rechargeable sodium-ion batteries containing these materials and methods of making these materials.

  12. Photoluminescence emission of nanoporous anodic aluminum oxide films prepared in phosphoric acid

    Science.gov (United States)

    Nourmohammadi, Abolghasem; Asadabadi, Saeid Jalali; Yousefi, Mohammad Hasan; Ghasemzadeh, Majid

    2012-12-01

    The photoluminescence emission of nanoporous anodic aluminum oxide films formed in phosphoric acid is studied in order to explore their defect-based subband electronic structure. Different excitation wavelengths are used to identify most of the details of the subband states. The films are produced under different anodizing conditions to optimize their emission in the visible range. Scanning electron microscopy investigations confirm pore formation in the produced layers. Gaussian analysis of the emission data indicates that subband states change with anodizing parameters, and various point defects can be formed both in the bulk and on the surface of these nanoporous layers during anodizing.

  13. Electrodeposited porous metal oxide films with interconnected nanoparticles applied as anode of lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Anguo, E-mail: hixiaoanguo@126.com; Zhou, Shibiao; Zuo, Chenggang; Zhuan, Yongbing; Ding, Xiang

    2014-12-15

    Highlights: • Highly porous NiO film is prepared by a co-electrodeposition method. • Porous NiO film is composed of interconnected nanoparticles. • Porous structure is favorable for fast ion/electron transfer. • Porous NiO film shows good lithium ion storage properties. - Abstract: Controllable synthesis of porous metal oxide films is highly desirable for high-performance electrochemical devices. In this work, a highly porous NiO film composed of interconnected nanoparticles is prepared by a simple co-electrodeposition method. The nanoparticles in the NiO film have a size ranging from 30 to 100 nm and construct large-quantity pores of 20–120 nm. As an anode material for lithium ion batteries, the highly porous NiO film electrode delivers a high discharge capacity of 700 mA h g{sup −1} at 0.2 C, as well as good high-rate performance. After 100 cycles at 0.2 C, a specific capacitance of 517 mA h g{sup −1} is attained. The good electrochemical performance is attributed to the interconnected porous structure, which facilitates the diffusion of ion and electron, and provides large reaction surface area leading to improved performance.

  14. The application of the barrier-type anodic oxidation method to thickness testing of aluminum films

    Science.gov (United States)

    Chen, Jianwen; Yao, Manwen; Xiao, Ruihua; Yang, Pengfei; Hu, Baofu; Yao, Xi

    2014-09-01

    The thickness of the active metal oxide film formed from a barrier-type anodizing process is directly proportional to its formation voltage. The thickness of the consumed portion of the metal film is also corresponding to the formation voltage. This principle can be applied to the thickness test of the metal films. If the metal film is growing on a dielectric substrate, when the metal film is exhausted in an anodizing process, because of the high electrical resistance of the formed oxide film, a sudden increase of the recorded voltage during the anodizing process would occur. Then, the thickness of the metal film can be determined from this voltage. As an example, aluminum films are tested and discussed in this work. This method is quite simple and is easy to perform with high precision.

  15. Optimization and Domestic Sourcing of Lithium Ion Battery Anode Materials

    Energy Technology Data Exchange (ETDEWEB)

    Wood, III, D. L.; Yoon, S. [A123 Systems, Inc.

    2012-10-25

    The purpose of this Cooperative Research and Development Agreement (CRADA) between ORNL and A123Systems, Inc. was to develop a low-temperature heat treatment process for natural graphite based anode materials for high-capacity and long-cycle-life lithium ion batteries. Three major problems currently plague state-of-the-art lithium ion battery anode materials. The first is the cost of the artificial graphite, which is heat-treated well in excess of 2000°C. Because of this high-temperature heat treatment, the anode active material significantly contributes to the cost of a lithium ion battery. The second problem is the limited specific capacity of state-of-the-art anodes based on artificial graphites, which is only about 200-350 mAh/g. This value needs to be increased to achieve high energy density when used with the low cell-voltage nanoparticle LiFePO4 cathode. Thirdly, the rate capability under cycling conditions of natural graphite based materials must be improved to match that of the nanoparticle LiFePO4. Natural graphite materials contain inherent crystallinity and lithium intercalation activity. They hold particular appeal, as they offer huge potential for industrial energy savings with the energy costs essentially subsidized by geological processes. Natural graphites have been heat-treated to a substantially lower temperature (as low as 1000-1500°C) and used as anode active materials to address the problems described above. Finally, corresponding graphitization and post-treatment processes were developed that are amenable to scaling to automotive quantities.

  16. Evaluation of Al and Some of Its Alloys as Anode Materials vs γ-MnO2 as Cathode Material and Ore Produced γ-MnO2 vs Zn Anode in KOH Solution

    Institute of Scientific and Technical Information of China (English)

    A.M.A.Hashem; Kh.S. Abou-El-Sherbini; S. Zein El Abedin; H. Abbas

    2006-01-01

    In this study electrochemical performance of Al and some of its alloys (Al-Zn, Al-Mg and Al-Mn) anodes vs MnO2 cathode were carried out in alkaline solution. The results show that the Al-Zn alloy anode has the best cell capacity among the other alloys. Cell capacity values go in the order Al-Zn>Al-Mg>Al>Al-Mn. This result is probably related to the nature of passive films formed on the surface of the alloys which examined by scanning electron microscopy (SEM). SEM morphologies of Al and its alloys showed coarse grains of passive films formed on the surface of these anode materials while Al-Mn morphology shows a needle-like structure.Electrolytic manganese dioxide (EMD) produced by electrodepositing on platinum anode from liquor resulting from reduction of low grade pyrolusite ore (β-MnO2) by sulfur slag was characterized as cathode in alkaline Zn-MnO2 batteries. Ore produced sample (EMD1) was performed well in comparison with EMD standard (EMD2) (commercial battery grade electrolytic manganese dioxide, TOSOH-Hellas GH-S). SEM morphology of Zn anode after cell reaction was carried out and showed that Zn anode has fine grains of passive film on its surface.

  17. High capacity anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Herman A.; Anguchamy, Yogesh Kumar; Deng, Haixia; Han, Yongbon; Masarapu, Charan; Venkatachalam, Subramanian; Kumar, Suject

    2015-11-19

    High capacity silicon based anode active materials are described for lithium ion batteries. These materials are shown to be effective in combination with high capacity lithium rich cathode active materials. Supplemental lithium is shown to improve the cycling performance and reduce irreversible capacity loss for at least certain silicon based active materials. In particular silicon based active materials can be formed in composites with electrically conductive coatings, such as pyrolytic carbon coatings or metal coatings, and composites can also be formed with other electrically conductive carbon components, such as carbon nanofibers and carbon nanoparticles. Additional alloys with silicon are explored.

  18. Electrophoretic deposition of PTFE particles on porous anodic aluminum oxide film and its tribological properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Dongya; Dong, Guangneng, E-mail: donggn@mail.xjtu.edu.cn; Chen, Yinjuan; Zeng, Qunfeng

    2014-01-30

    Polytetrafluoroethylene (PTFE) composite film was successfully fabricated by depositing PTFE particles into porous anodic aluminum oxide film using electrophoretic deposition (EPD) process. Firstly, porous anodic aluminum oxide film was synthesized by anodic oxidation process in sulphuric acid electrolyte. Then, PTFE particles in suspension were directionally deposited into the porous substrate. Finally, a heat treatment at 300 °C for 1 h was utilized to enhance PTFE particles adhesion to the substrate. The influence of anodic oxidation parameters on the morphology and micro-hardness of the porous anodic aluminum oxide film was studied and the PTFE particles deposited into the pores were authenticated using energy-dispersive spectrometer (EDS) and scanning electron microscopy (SEM). Tribological properties of the PTFE composite film were investigated under dry sliding. The experimental results showed that the composite film exhibit remarkable low friction. The composite film had friction coefficient of 0.20 which deposited in 15% PTFE emulsion at temperature of 15 °C and current density of 3 A/dm{sup 2} for 35 min. In addition, a control specimen of porous anodic aluminum oxide film and the PTFE composite film were carried out under the same test condition, friction coefficient of the PTFE composite film was reduced by 60% comparing with the control specimen at 380 MPa and 100 mm/s. The lubricating mechanism was that PTFE particles embedded in porous anodic aluminum oxide film smeared a transfer film on the sliding path and the micro-pores could support the supplement of solid lubricant during the sliding, which prolonged the lubrication life of the aluminum alloys.

  19. Electrophoretic deposition of PTFE particles on porous anodic aluminum oxide film and its tribological properties

    Science.gov (United States)

    Zhang, Dongya; Dong, Guangneng; Chen, Yinjuan; Zeng, Qunfeng

    2014-01-01

    Polytetrafluoroethylene (PTFE) composite film was successfully fabricated by depositing PTFE particles into porous anodic aluminum oxide film using electrophoretic deposition (EPD) process. Firstly, porous anodic aluminum oxide film was synthesized by anodic oxidation process in sulphuric acid electrolyte. Then, PTFE particles in suspension were directionally deposited into the porous substrate. Finally, a heat treatment at 300 °C for 1 h was utilized to enhance PTFE particles adhesion to the substrate. The influence of anodic oxidation parameters on the morphology and micro-hardness of the porous anodic aluminum oxide film was studied and the PTFE particles deposited into the pores were authenticated using energy-dispersive spectrometer (EDS) and scanning electron microscopy (SEM). Tribological properties of the PTFE composite film were investigated under dry sliding. The experimental results showed that the composite film exhibit remarkable low friction. The composite film had friction coefficient of 0.20 which deposited in 15% PTFE emulsion at temperature of 15 °C and current density of 3 A/dm2 for 35 min. In addition, a control specimen of porous anodic aluminum oxide film and the PTFE composite film were carried out under the same test condition, friction coefficient of the PTFE composite film was reduced by 60% comparing with the control specimen at 380 MPa and 100 mm/s. The lubricating mechanism was that PTFE particles embedded in porous anodic aluminum oxide film smeared a transfer film on the sliding path and the micro-pores could support the supplement of solid lubricant during the sliding, which prolonged the lubrication life of the aluminum alloys.

  20. INFLUENCE OF MAGNETIC FIELD ON ACCURACY OF ECM BY CHANGING THE CONDUCTIVITY OF ANODE FILM

    Institute of Scientific and Technical Information of China (English)

    FAN Zhijian; ZHANG Lixin; TANG lin

    2008-01-01

    The change of conductivity, thickness and scanning electron microscopy (SEM) appearance of the anode film of CrWMn in 10( NaNO3 at different anode potential either with or without the magnetic field applied are investigated by testing film resistance, galvanostatic transient and using SEM to design magnetic circuit in magnetic assisted electrochemical machining (MAECM). The experiments show that the anode film has semi-conducting property. Compared with the situation without magnetic field applied, the resistance of the film formed at 1.8V (anode potential) increased and decreased at 4.0V while B=0.4T and the magnetic north pole points toward anode. The SEM photo demonstrates that the magnetic field will densify the film in the passivation area and quicken dissolution of the anode metal in over-passivation area. Based on the influence of magnetic field on electrochemical machining(ECM) due to the changes of the anode film conductivity behavior, the magnetic north pole should be designed to point towards the workpiece surface that has been machined. Process experiments agree with the results of test analysis.

  1. Thin films for material engineering

    Science.gov (United States)

    Wasa, Kiyotaka

    2016-07-01

    Thin films are defined as two-dimensional materials formed by condensing one by one atomic/molecular/ionic species of matter in contrast to bulk three-dimensional sintered ceramics. They are grown through atomic collisional chemical reaction on a substrate surface. Thin film growth processes are fascinating for developing innovative exotic materials. On the basis of my long research on sputtering deposition, this paper firstly describes the kinetic energy effect of sputtered adatoms on thin film growth and discusses on a possibility of room-temperature growth of cubic diamond crystallites and the perovskite thin films of binary compound PbTiO3. Secondly, high-performance sputtered ferroelectric thin films with extraordinary excellent crystallinity compatible with MBE deposited thin films are described in relation to a possible application for thin-film MEMS. Finally, the present thin-film technologies are discussed in terms of a future material science and engineering.

  2. Structured SiCu thin films in LiB as anodes

    Energy Technology Data Exchange (ETDEWEB)

    Polat, B.D., E-mail: bpolat@itu.edu.tr [Department of Metallurgical and Materials Engineering, Istanbul Technical University, Maslak, Istanbul 34469 (Turkey); Eryilmaz, O.L.; Erck, R. [Energy Systems Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Keleş, O., E-mail: ozgulkeles@itu.edu.tr [Department of Metallurgical and Materials Engineering, Istanbul Technical University, Maslak, Istanbul 34469 (Turkey); Erdemir, A. [Energy Systems Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Amine, K. [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2014-12-01

    Both helical and inclined columnar Si–10 at.% Cu structured thin films were deposited on Cu substrates using glancing angle deposition (GLAD) technique. In order to deposit Cu and Si two evaporation sources were used. Ion assistance was utilized in the first 5 min of the GLAD to enhance the adhesion and the density of the films. These films were characterized by thin film XRD, GDOES, SEM, and EDS. Electrochemical characterizations were made by testing the thin films as anodes in half-cells for 100 cycles. The results showed that the columnar SiCu thin film delivered 2200 mAh g{sup −1}, where the helical one exhibited 2600 mAh g{sup −1}, and, their initial coulombic efficiencies were found to be 38%–50% respectively. For the columnar and the helical thin film anodes, sustainable 520 and 800 mAh g{sup −1} with 90% and 99% coulombic efficiencies were achieved for 100 cycles. These sustainable capacities showed the importance of the thin film structure having nano-sized crystals and amorphous particles. The higher surface area of the helices increases the capacity of the electrode because the contact area of the thin film anode with Li ions is increased, and the polarization which otherwise forms on the anode surface due to SEI formation is decreased. In addition, because of larger interspaces between the helices the ability of the anode to accommodate the volumetric changes is improved, which results in a higher coulombic efficiency and capacity retention during cycling test. - Highlights: • Cu and Si atoms were co-evaporated to form composite thin film. • GLAD is an alternative method to form new electrodes for LIB. • Uses of the composite helices and nanocolumns as anodes were shown experimentally. • IAD was used to improve the adhesion of the structured thin films. • High surface area, porosities and Cu presence improve the Si anode performance.

  3. Atomic layer deposited tungsten nitride thin films as a new lithium-ion battery anode.

    Science.gov (United States)

    Nandi, Dip K; Sen, Uttam K; Sinha, Soumyadeep; Dhara, Arpan; Mitra, Sagar; Sarkar, Shaibal K

    2015-07-14

    This article demonstrates the atomic layer deposition (ALD) of tungsten nitride using tungsten hexacarbonyl [W(CO)6] and ammonia [NH3] and its use as a lithium-ion battery anode. In situ quartz crystal microbalance (QCM), ellipsometry and X-ray reflectivity (XRR) measurements are carried out to confirm the self-limiting behaviour of the deposition. A saturated growth rate of ca. 0.35 Å per ALD cycle is found within a narrow temperature window of 180-195 °C. In situ Fourier transform infrared (FTIR) vibrational spectroscopy is used to determine the reaction pathways of the surface bound species after each ALD half cycle. The elemental presence and chemical composition is determined by XPS. The as-deposited material is found to be amorphous and crystallized to h-W2N upon annealing at an elevated temperature under an ammonia atmosphere. The as-deposited materials are found to be n-type, conducting with an average carrier concentration of ca. 10(20) at room temperature. Electrochemical studies of the as-deposited films open up the possibility of this material to be used as an anode material in Li-ion batteries. The incorporation of MWCNTs as a scaffold layer further enhances the electrochemical storage capacity of the ALD grown tungsten nitride (WNx). Ex situ XRD analysis confirms the conversion based reaction mechanism of the as-grown material with Li under operation.

  4. Aluminum/MoO3 anode thin films: an effective anode structure for highperformance flexible organic optoelectronics

    Institute of Scientific and Technical Information of China (English)

    Ding Lei; Zhang Fanghui; Ma Ying; Zhang Maili

    2012-01-01

    We report Al/MoO3 thin film used as a complex anode in high-performance OLEDs.The unique efficacy of the device was found to result from the enhanced injection of holes into the commonly used hole-transporting molecules due to a large reduction in the interface dipole at the anode/organic interface.The superior optical characteristics are attributed to a strong cavity effect,Due to the ease of processing Al/MoO3 we successfully demonstrated large-area flexible OLEDs on plastic substrates with uniform emission.

  5. Preparation of bioactive titania films on titanium metal via anodic oxidation.

    Science.gov (United States)

    Cui, X; Kim, H-M; Kawashita, M; Wang, L; Xiong, T; Kokubo, T; Nakamura, T

    2009-01-01

    To research the crystal structure and surface morphology of anodic films on titanium metal in different electrolytes under various electrochemical conditions and investigate the effect of the crystal structure of the oxide films on apatite-forming ability in simulated body fluid (SBF). Titanium oxide films were prepared using an anodic oxidation method on the surface of titanium metal in four different electrolytes: sulfuric acid, acetic acid, phosphoric acid and sodium sulfate solutions with different voltages for 1 min at room temperature. Anodic films that consisted of rutile and/or anatase phases with porous structures were formed on titanium metal after anodizing in H(2)SO(4) and Na(2)SO(4) electrolytes, while amorphous titania films were produced after anodizing in CH(3)COOH and H(3)PO(4) electrolytes. Titanium metal with the anatase and/or rutile crystal structure films showed excellent apatite-forming ability and produced a compact apatite layer covering all the surface of titanium after soaking in SBF for 7d, but titanium metal with amorphous titania layers was not able to induce apatite formation. The resultant apatite layer formed on titanium metal in SBF could enhance the bonding strength between living tissue and the implant. Anodic oxidation is believed to be an effective method for preparing bioactive titanium metal as an artificial bone substitute even under load-bearing conditions.

  6. An anode with aluminum doped on zinc oxide thin films for organic light emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Xu Denghui [Institute of Optoelectronic Technology, Key Laboratory of Information Storage and Display, Beijing Jiaotong University, Beijing 100044 (China); Deng Zhenbo [Institute of Optoelectronic Technology, Key Laboratory of Information Storage and Display, Beijing Jiaotong University, Beijing 100044 (China)]. E-mail: zbdeng@center.njtu.edu.cn; Xu Ying [Institute of Optoelectronic Technology, Key Laboratory of Information Storage and Display, Beijing Jiaotong University, Beijing 100044 (China); Xiao Jing [Institute of Optoelectronic Technology, Key Laboratory of Information Storage and Display, Beijing Jiaotong University, Beijing 100044 (China); Liang Chunjun [Institute of Optoelectronic Technology, Key Laboratory of Information Storage and Display, Beijing Jiaotong University, Beijing 100044 (China); Pei Zhiliang [Institute of Metal Research, Chinese Academy of Science, Shenyang 110016 (China); Sun Chao [Institute of Metal Research, Chinese Academy of Science, Shenyang 110016 (China)

    2005-10-10

    Doped zinc oxides are attractive alternative materials as transparent conducting electrode because they are nontoxic and inexpensive compared with indium tin oxide (ITO). Transparent conducting aluminum-doped zinc oxide (AZO) thin films have been deposited on glass substrates by DC reactive magnetron sputtering method. Films were deposited at a substrate temperature of 150-bar {sup o}C in 0.03 Pa of oxygen pressure. The electrical and optical properties of the film with the Al-doping amount of 2 wt% in the target were investigated. For the 300-nm thick AZO film deposited using a ZnO target with an Al content of 2 wt%, the lowest electrical resistivity was 4x10{sup -4}{omega}cm and the average transmission in the visible range 400-700 nm was more than 90%. The AZO film was used as an anode contact to fabricate organic light-emitting diodes. The device performance was measured and the current efficiency of 2.9 cd/A was measured at a current density of 100 mA/cm{sup 2}.

  7. Anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Abouimrane, Ali; Amine, Khalil

    2017-04-11

    An electrochemical device includes a composite material of general Formula (1-x)J-(x)Q wherein: J is a metal carbon alloy of formula Sn.sub.zSi.sub.z'Met.sub.wMet'.sub.w'C.sub.t; Q is a metal oxide of formula A.sub..gamma.M.sub..alpha.M'.sub..alpha.'O.sub..beta.; and wherein: A is Li, Na, or K; M and M' are individually Ge, Mo, Al, Ga, As, Sb, Te, Ti, Ta, Zr, Ca, Mg, Sr, Ba, Li, Na, K, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Rt, Ru or Cd; Met and Met' are individually Ge, Mo, Al, Ga, As, Sb, Te, Ti, Ta, Zr, Ca, Mg, Sr, Ba, Li, Na, K, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Rt, Ru or Cd; 0

  8. Anodized titania: Processing and characterization to improve cell-materials interactions for load bearing implants

    Science.gov (United States)

    Das, Kakoli

    The objective of this study is to investigate in vitro cell-materials interactions using human osteoblast cells on anodized titanium. Titanium is a bioinert material and, therefore, gets encapsulated after implantation into the living body by a fibrous tissue that isolates them from the surrounding tissues. In this work, bioactive nonporous and nanoporous TiO2 layers were grown on commercially pure titanium substrate by anodization process using different electrolyte solutions namely (1) H3PO 4, (2) HF and (3) H2SO4, (4) aqueous solution of citric acid, sodium fluoride and sulfuric acid. The first three electrolytes produced bioactive TiO2 films with a nonporous structure showing three distinctive surface morphologies. Nanoporous morphology was obtained on Ti-surfaces from the fourth electrolyte at 20V for 4h. Cross-sectional view of the nanoporous surface reveals titania nanotubes of length 600 nm. It was found that increasing anodization time initially increased the height of the nanotubes while maintaining the tubular array structure, but beyond 4h, growth of nanotubes decreased with a collapsed array structure. Human osteoblast (HOB) cell attachment and growth behavior were studied using an osteoprecursor cell line (OPC 1) for 3, 7 and 11 days. Colonization of the cells was noticed with distinctive cell-to-cell attachment on HF anodized surfaces. TiO2 layer grown in H2SO4 electrolyte did not show significant cell growth on the surface, and some cell death was also noticed. Good cellular adherence with extracellular matrix extensions in between the cells was noticed for samples anodized with H3PO 4 electrolyte and nanotube surface. Cell proliferation was excellent on anodized nanotube surfaces. An abundant amount of extracellular matrix (ECM) between the neighboring cells was also noticed on nanotube surfaces with filopodia extensions coming out from cells to grasp the nanoporous surface for anchorage. To better understand and compare cell-materials interactions

  9. An Analysis of Mechanical Properties of Anodized Aluminum Film at High Stress

    Science.gov (United States)

    Zhao, Xixi; Wei, Guoying; Yu, Yundan; Guo, Yuemei; Zhang, Ao

    2015-10-01

    In this paper, a new environmental-friendly electrolyte containing sulfuric acid and tartaric acid has been used as the substitute of chromic acid for anodization. The work discussed the influence of anodizing voltages on the fatigue life of anodized Al 2024-T3 by performing fatigue tests with 0.1 stress ratio (R) at 320 MPa. Meanwhile the fatigue cycles to failure, yield strength, tensile strength and fracture surface of anodic films at different conditions were investigated. The results showed that the fatigue life of anodized and sealed specimens reduced a lot compared to aluminum alloy, which can be attributed to the crack sites initiated at the oxide layer. The fracture surface analyses also revealed that the number of crack initiation sites enlarged with the increase of anodizing voltage.

  10. Structure and Optical Properties of thin Porous Anodic Alumina Films Synthesized on a Glass Surface

    Science.gov (United States)

    Valeev, R. G.; Petukhov, D. I.; Kriventsov, V. V.

    The structure and luminescent properties of thin nanoporous aluminum oxide films obtained by anodization of aluminum films thermally deposited on glass have been investigated. The pore size and the interpore distance depend on the anodization voltage. For all studied samples the highest emission intensity obtained at the excitation wavelength equal to 330 nm. This behavior of luminescence curves caused by defect F+ luminescent centers (O- oxygen vacancies). The presence of porous alumina films on the glass surface increases the optical absorption in the visible light region. The oscillations on the spectra are caused by Fabry-Perot interference on the anodic alumina oxide film/glass interface. The suggested technique can be used for obtaining porous aluminum oxide films on other substrates, including Indium-Tin-Oxide, and can be applied in the technology of light-emitting devices and infrared-visible-ultraviolet detectors.

  11. Sandwiched Thin-Film Anode of Chemically Bonded Black Phosphorus/Graphene Hybrid for Lithium-Ion Battery.

    Science.gov (United States)

    Liu, Hanwen; Zou, Yuqin; Tao, Li; Ma, Zhaoling; Liu, Dongdong; Zhou, Peng; Liu, Hongbo; Wang, Shuangyin

    2017-09-01

    A facile vacuum filtration method is applied for the first time to construct sandwich-structure anode. Two layers of graphene stacks sandwich a composite of black phosphorus (BP), which not only protect BP from quickly degenerating but also serve as current collector instead of copper foil. The BP composite, reduced graphene oxide coated on BP via chemical bonding, is simply synthesized by solvothermal reaction at 140 °C. The sandwiched film anode used for lithium-ion battery exhibits reversible capacities of 1401 mAh g(-1) during the 200th cycle at current density of 100 mA g(-1) indicating superior cycle performance. Besides, this facile vacuum filtration method may also be available for other anode material with well dispersion in N-methyl pyrrolidone (NMP). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Growth of porous type anodic oxide films at micro-areas on aluminum exposed by laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Tatsuya [Graduate School of Engineering, Hokkaido University, N13-W8, Kita-Ku, Sapporo 060-8628 (Japan)], E-mail: kiku@eng.hokudai.ac.jp; Sakairi, Masatoshi [Graduate School of Engineering, Hokkaido University, N13-W8, Kita-Ku, Sapporo 060-8628 (Japan); Takahashi, Hideaki [Asahikawa National College of Technology, Syunkohdai, 2-2, 1-6, Asahikawa 071-8142 (Japan)

    2009-11-30

    Aluminum covered with pore-sealed anodic oxide films was irradiated with a pulsed Nd-YAG laser to remove the oxide film at micro-areas. The specimen was re-anodized for long periods to examine the growth of porous anodic oxide films at the area where substrate had been exposed by measuring current variations and morphological changes in the oxide during the re-anodizing. The chemical dissolution resistance of the pore-sealed anodic oxide films in an oxalic acid solution was also examined by measuring time-variations in rest potentials during immersion. The resistance to chemical dissolution of the oxide film became higher with increasing pore-sealing time and showed higher values at lower solution temperatures. During potentiostatic re-anodizing at five 35-{mu}m wide and 4-mm long lines for 72 h after the film was removed the measured current was found to increase linearly with time. Semicircular columnar-shaped porous type anodic oxide was found to form during the re-anodizing at the laser-irradiated area, and was found to grow radially, thus resulting in an increase in the diameter. After long re-anodizing, the central and top parts of the oxide protruded along the longitudinal direction of the laser-irradiated area. The volume expansion during re-anodizing resulted in the formation of cracks, parallel to the lines, in the oxide film formed during the first anodizing.

  13. ANODE CATALYST MATERIALS FOR USE IN FUEL CELLS

    DEFF Research Database (Denmark)

    2002-01-01

    Catalyst materials having a surface comprising a composition M¿x?/Pt¿3?/Sub; wherein M is selected from the group of elements Fe, Co, Rh and Ir; or wherein M represent two different elements selected from the group comprising Fe, CO, Rh, Ir, Ni, Pd, CU, Ag, Au and Sn; and wherein Sub represents...... a substrate material selected from Ru and Os; the respective components being present within specific ranges, display improved properties for use inanodes for low-temperature fuel cell anodes for PENFC fuel cells and direct methanol fuel cells....

  14. Fabrication of highly ordered porous nickel oxide anode materials and their electrochemical characteristics in lithium storage

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Fengjuan [College of Communications and Electronics Engineering, Qiqihar University, 42 Wenhua Street, Qiqihar, Heilongjiang 161006 (China); National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Li, Qianqian [College of Communications and Electronics Engineering, Qiqihar University, 42 Wenhua Street, Qiqihar, Heilongjiang 161006 (China); Tao, Bairui, E-mail: tbr_sir@163.com [Computer Center, Qiqihar University, 42 Wenhua Street, Qiqihar, Heilongjiang 161006 (China); National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Chu, Paul K. [Department of Physics and Material Sciences, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2014-05-01

    Highlights: • NiO/Si-MCP nanocomposites electrocatalysts as anodes in lithium ion batteries. • Si MCP itself is an excellent support for electrocatalyst. • The structure with high surface to volume ratio endows higher mass NiO nanopatricles. • The ordered channel and mesoporous structure permits liquid electrolyte flow easily. • This research may provide a meaning way in integratable lithium-ion batteries. - Abstract: The structure and electrochemical properties of silicon microchannel plates (MCP)-supported NiO nanocomposites (NiO/Si-MCP) synthesized by silicon micromachining, electroless plating, and thermal annealing are investigated as anodes in lithium ion batteries. Galvanostatic charge and discharge results indicate that the NiO/Si-MCP is capable of delivering a higher capacity than the bare nickel-oxide film. At a 1 C current, the NiO/Si-MCP nanocomposite film shows an enormous first discharge capacity of about 3190 mA g{sup −1} and charge capacity of 1977 mA g{sup −1}. After 15 cycles, the NiO/Si-MCP nanocomposite retains a reversible capacity of 1531 mA g{sup −1} with 63.7% of the capacity maintained in the 2nd cycle. The lithium storage capacity is maintained at ∼880 mA h g{sup −1} after 50 discharge/charge cycles and it is much larger than that of NiO and its composites. The enhanced electrochemical performance of the highly ordered three-dimensional materials is attributed to the synergistic effects offered by the silicon microchannel plates in the nickel oxide film subsequently facilitating electrolyte penetration, diffusion, and migration. The structure is promising anode materials in lithium-ion batteries.

  15. Facile Fabrication of Anodic Alumina Rod-Capped Nanopore Films with Condensate Microdrop Self-Propelling Function.

    Science.gov (United States)

    Li, Juan; Zhang, Wenjing; Luo, Yuting; Zhu, Jie; Gao, Xuefeng

    2015-08-26

    We report that aluminum surfaces can be endowed with condensate microdrop self-propelling (CMDSP) function by one-step voltage-rising mild anodization in hot phosphoric acid solution followed by fluorosilane modification. Via regulating reaction parameters, we can achieve anodic alumina self-standing rod-capped nanopore films and minimize their solid-liquid interface adhesion. Such low-adhesive nanostructured film owns remarkable CMDSP function, especially to condensate microdrops with sizes below 50 μm, differing from usual gravity-driven dropwise condensation on flat aluminum surfaces. Clearly, this work offers a facile, efficient, and industry-compatible approach to processing CMDSP aluminum materials, which is significant for developing innovative energy-saving air-conditioner heat exchangers.

  16. Highly conductive freestanding graphene films as anode current collectors for flexible lithium-ion batteries.

    Science.gov (United States)

    Rana, Kuldeep; Singh, Jyoti; Lee, Jeong-Taik; Park, Jong Hyeok; Ahn, Jong-Hyun

    2014-07-23

    The electrodes in lithium-ion batteries (LIBs) are typically films that are arranged on metal foil current collectors with a thickness of several tens of μm. Here, we report on the preparation of a thick free-standing graphene film synthesized by CVD as an alternative to Cu foil as an anode current collector. As a model system, MoS2 anodes with a flower-like morphology were anchored onto the surface of the thick graphene film. A hybrid and binder free anode without a conventional metal current collector exhibited an excellent capacity value of around 580 mAh/g (@50 mA/g) and reasonable charge/discharge cyclability. The work presented here may stimulate the use of graphene films as replacements for conventional current collectors and additive free electrode in LIBs.

  17. The surface treatment on oxide film of pure titanium Part 1. The effect of Anodic oxidation

    Institute of Scientific and Technical Information of China (English)

    Ge Wang; Xiangrong Cheng

    2006-01-01

    目的:研究阳极氧化对纯钛种植材料氧化膜的影响.方法:5片直径9 mm厚2 mm的纯钛在升压速度为7~8 v/min、电流密度≤10 mA/cm2的条件下分别进行阳极氧化处理,(A)10 v 10 min,(B)24 v 10 min,(C) 40 v 10 min,(D)24 v 40 min,(E) 24 v 2 h.用potentiostat仪检测以上样品在生理盐水和人造海水中的电化学行为.结果:以上样品的颜色呈:A蓝色,B淡黄色,C粉红色,D金黄色,E深黄色.随着电压的升高和作用时间的延长,2.55峰渐渐强化,2.34峰弱化.在生理盐水中,阳极氧化膜的开路电势稳定于0 mV,而自然氧化膜则很快从-50上升到-40 mV,极化电流比自然氧化膜的低100倍.在人造海水中,阳极氧化膜的开路电势稳定在-90 mV,自然氧化膜则从-480 mV快速上升到-310 mV,且活化电流明显高于阳极氧化膜.结论:阳极氧化膜的颜色可能和膜的厚度有关,而颜色对种植体上的修复体有影响,因此,金黄色被选为理想的颜色.2.55和2.34峰的变化规律尚无法解释.阳极氧化膜的稳定性和耐腐蚀性远远高于自然氧化膜.因此,阳极氧化法是一种提高纯钛氧化膜耐腐蚀性的好方法.%Objectives: To study the oxide film of pure titanium implant material treated by anodic oxidation. Methods: Five commercially pure (CP) titanium sheets (9mm in diameter and 2mm thick) were treated by the speed of 7-8 v/min of potential, the current density ≤10mA/cm2 to (A) 10v for 10min, (B) 24v for 10min, (C) 40v for 10min, (D) 24v for 40min, (E) 24v for 2hr in Kawahara's electrochemical solution. The electro-chemical behavior of anodic oxide film and natural oxide film was studied using a potentiostat. Results: The samples color changed from white to the following sequence blue, light gold, pink, media gold and dark gold. Along with potential and time going on, XRD patterns showed that the peak 2.55 strengthened, and peak 2.34 weakened. The voltage-time curve in physiological salt solution (PSS) showed

  18. XPS, time-of-flight-SIMS and polarization modulation IRRAS study of Cr{sub 2}O{sub 3} thin film materials as anode for lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Li Juntao [Laboratoire de Physico-Chimie des Surfaces, CNRS (UMR 7045), Ecole Nationale Superieure de Chimie de Paris, Universite Pierre et Marie Curie, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Maurice, Vincent [Laboratoire de Physico-Chimie des Surfaces, CNRS (UMR 7045), Ecole Nationale Superieure de Chimie de Paris, Universite Pierre et Marie Curie, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France)], E-mail: vincent-maurice@enscp.fr; Swiatowska-Mrowiecka, Jolanta; Seyeux, Antoine; Zanna, Sandrine; Klein, Lorena [Laboratoire de Physico-Chimie des Surfaces, CNRS (UMR 7045), Ecole Nationale Superieure de Chimie de Paris, Universite Pierre et Marie Curie, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); Sun Shigang [State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China)], E-mail: sgsun@xmu.edu.cn; Marcus, Philippe [Laboratoire de Physico-Chimie des Surfaces, CNRS (UMR 7045), Ecole Nationale Superieure de Chimie de Paris, Universite Pierre et Marie Curie, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France)], E-mail: philippe-marcus@enscp.fr

    2009-05-30

    Ultra-thin Cr{sub 2}O{sub 3} films (12.0, 17.3 and 29.6 nm thick) were produced on Cr metal by thermal oxidation, and their electrochemical properties in 1 M LiClO{sub 4} in propylene carbonate (PC) were investigated by cyclic voltammetry and chronopotentiometry. The reductive electrolyte decomposition and the conversion/deconversion process were observed and analyzed by X-ray photoelectron spectroscopy (XPS), polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The initial irreversible capacity due to the reduction of electrolyte and the incomplete deconversion process during the first cycle is 70% of the first discharge capacity. A stable charge/discharge capacity of 460 mAh g{sup -1} was obtained in the 3rd to 10th cycles. XPS and PM-IRRAS evidenced the growth of a solid electrolyte interphase (SEI) layer that is constituted of Li{sub 2}CO{sub 3} formed by reductive decomposition of the electrolyte. The SEI layer thickness and/or density is modified by the conversion/deconversion reaction. ToF-SIMS evidenced the volume expansion/shrink resulting from the conversion/deconversion reaction. ToF-SIMS also revealed an incomplete conversion process limited by mass transport, which partitions the oxide into a converted outer part assigned to Li{sub 2}O containing Cr traces and an unconverted inner part ascribed to Cr{sub 2}O{sub 3} or lower Cr oxide containing Li. It was found that the deconversion re-homogenizes the oxide film in a single layer but with lithium trapped in it. The present study provides a detailed understanding of the interfacial reaction on the oxide anode undergoing a conversion/deconversion reaction.

  19. Impact of nanostructured anode on low-temperature performance of thin-film-based anode-supported solid oxide fuel cells

    Science.gov (United States)

    Park, Jung Hoon; Han, Seung Min; Yoon, Kyung Joong; Kim, Hyoungchul; Hong, Jongsup; Kim, Byung-Kook; Lee, Jong-Ho; Son, Ji-Won

    2016-05-01

    The impact of a nanostructured Ni-yttria-stabilized zirconia (Ni-YSZ) anode on low-temperature solid oxide fuel cell (LT-SOFC) performance is investigated. By modifying processing techniques for the anode support, anode-supported SOFCs based on thin-film (∼1 μm) electrolytes (TF-SOFCs) with and without the nanostructured Ni-YSZ (grain size ∼100 nm) anode are fabricated and a direct comparison of the TF-SOFCs to reveal the role of the nanostructured anode at low temperature is made. The cell performance of the nanostructured Ni-YSZ anode significantly increases as compared to that of the cell without it, especially at low temperatures (500 °C). The electrochemical analyses confirm that increasing the triple-phase boundary (TPB) density near the electrolyte and anode interface by the particle-size reduction of the anode increases the number of sites available for charge transfer. Thus, the nanostructured anode not only secures the structural integrity of the thin-film components over it, it is also essential for lowering the operating temperature of the TF-SOFC. Although it is widely considered that the cathode is the main factor that determines the performance of LT-SOFCs, this study directly proves that anode performance also significantly affects the low-temperature performance.

  20. Structural and optical characterizations of porous anodic alumina-aluminum nanocomposite films on borofloat substrates

    Science.gov (United States)

    Arslan, Hande Cavus; Yusufoglu, Ibrahim; Aslan, Mustafa M.

    2014-07-01

    Structural and optical properties of the porous anodic alumina (PAA)-aluminum (Al) nanocomposite and the PAA-nanostructured films on borofloat substrates are studied. The films are fabricated by the anodization of 170- to 200- and 295- to 330-nm-thick Al sputtered onto the borofloat. The anodization process is stopped at different times in order to form the PAA-Al nanocomposite films with different layer thicknesses. Then, the pore widening is applied to 189- to 210- and 430- to 495-nm-thick PAA films in 5- and 10-min intervals, respectively. The structural properties of the films are characterized by a scanning electron microscopy. The nanocomposite films are also characterized optically by total reflection and directional transmission measurements in the wavelength range between 250 and 800 nm. Our results indicate that controlling the thicknesses of both Al and the PAA layers by anodization time and the morphology of the nanostructures by chemical etching duration in the PAA layer provides unique PAA-Al nanocomposite films with desired optical properties.

  1. Modelling the growth process of porous aluminum oxide film during anodization

    Science.gov (United States)

    Aryslanova, E. M.; Alfimov, A. V.; Chivilikhin, S. A.

    2015-11-01

    Currently it has become important for the development of metamaterials and nanotechnology to obtain regular self-assembled structures. One such structure is porous anodic alumina film that consists of hexagonally packed cylindrical pores. In this work we consider the anodization process, our model takes into account the influence of layers of aluminum and electrolyte on the rate of growth of aluminum oxide, as well as the effect of surface diffusion. In present work we consider those effects. And as a result of our model we obtain the minimum distance between centers of alumina pores in the beginning of anodizing process.

  2. Structured SiCu thin films in LiB as anodes

    Energy Technology Data Exchange (ETDEWEB)

    Polat, Billur Deniz [Istanbul Technical Univ. (Turkey); Eryilmaz, Osman Levent [Argonne National Lab. (ANL), Argonne, IL (United States); Erck, Robert [Argonne National Lab. (ANL), Argonne, IL (United States); Keles, O. [Istanbul Technical Univ. (Turkey); Erdemir, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Amine, Khalil [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-09-16

    Both helical and inclined columnar Si–10 at.% Cu structured thin films were deposited on Cu substrates using glancing angle deposition (GLAD) technique. In order to deposit Cu and Si two evaporation sources were used. Ion assistance was utilized in the first 5 min of the GLAD to enhance the adhesion and the density of the films. These films were characterized by thin film XRD, GDOES, SEM, and EDS. Electrochemical characterizations were made by testing the thin films as anodes in half-cells for 100 cycles. The results showed that the columnar SiCu thin film delivered 2200 mAh g-1, where the helical one exhibited 2600 mAh g-1, and, their initial coulombic efficiencies were found to be 38%–50% respectively. For the columnar and the helical thin film anodes, sustainable 520 and 800 mAh g-1 with 90% and 99% coulombic efficiencies were achieved for 100 cycles. These sustainable capacities showed the importance of the thin film structure having nano-sized crystals and amorphous particles. The higher surface area of the helices increases the capacity of the electrode because the contact area of the thin film anode with Li ions is increased, and the polarization which otherwise forms on the anode surface due to SEI formation is decreased. In addition, because of larger interspaces between the helices the ability of the anode to accommodate the volumetric changes is improved, which results in a higher coulombic efficiency and capacity retention during cycling test.

  3. Graphene composites as anode materials in lithium-ion batteries

    Science.gov (United States)

    Mazar Atabaki, M.; Kovacevic, R.

    2013-03-01

    Since the world of mobile phones and laptops has significantly altered by a big designer named Steve Jobs, the electronic industries have strived to prepare smaller, thinner and lower weight products. The giant electronic companies, therefore, compete in developing more efficient hardware such as batteries used inside the small metallic or polymeric frame. One of the most important materials in the production lines is the lithium-based batteries which is so famous for its ability in recharging as many times as a user needs. However, this is not an indication of being long lasted, as many of the electronic devices are frequently being used for a long time. The performance, chemistry, safety and above all cost of the lithium ion batteries should be considered when the design of the compounds are at the top concern of the engineers. To increase the efficiency of the batteries a combination of graphene and nanoparticles is recently introduced and it has shown to have enormous technological effect in enhancing the durability of the batteries. However, due to very high electronic conductivity, these materials can be thought of as preparing the anode electrode in the lithiumion battery. In this paper, the various approaches to characterize different types of graphene/nanoparticles and the process of preparing the anode for the lithium-ion batteries as well as their electrical properties are discussed.

  4. Formation of Al-Si Composite Oxide Film by Hydrolysis Precipitation and Anodizing

    Institute of Scientific and Technical Information of China (English)

    Zhe-Sheng Feng; Ying-Jie Xia; Jia Ding; Jin-Ju Chen

    2007-01-01

    This paper presents a new technique in the high dielectric constant composite oxide film preparation.On the basis of nanocompsite high dielectric constant aluminum oxide film growth technology, a new idea of adulterating Si oxide species into the aluminum composite film was proposed. As a result, the specific capacitance and withstanding voltage of the composite oxide film formed at the anodizing voltage of 20V are enhanced, and the leakage current of the aluminum composite oxide film is reduced through incorporation of Si oxide species.

  5. Surface Morphology and Growth of Anodic Titania Nanotubes Films: Photoelectrochemical Water Splitting Studies

    Directory of Open Access Journals (Sweden)

    Chin Wei Lai

    2015-01-01

    become the most studied material as they exhibit promising functional properties. In the present study, anodic TiO2 films with different surface morphologies can be synthesized in an organic electrolyte of ethylene glycol (EG by controlling an optimum content of ammonium fluoride (NH4F using electrochemical anodization technique. Based on the results obtained, well-aligned and bundle-free TiO2 nanotube arrays with diameter of 100 nm and length of 8 µm were successfully synthesized in EG electrolyte containing ≈5 wt% of NH4F for 1 h at 60 V. However, formation of nanoporous structure and compact oxide layer would be favored if the content of NH4F was less than 5 wt%. In the photoelectrochemical (PEC water splitting studies, well-aligned TiO2 nanotubular structure exhibited higher photocurrent density of ≈1 mA/cm2 with photoconversion efficiency of ≈2% as compared to the nanoporous and compact oxide layer due to the higher active surface area for the photon absorption to generate more photo-induced electrons during photoexcitation stage.

  6. Finite Element Analysis of Silicon Thin Films on Soft Substrates as Anodes for Lithium Ion Batteries

    Science.gov (United States)

    Shaffer, Joseph

    2011-12-01

    The wide-scale use of green technologies such as electric vehicles has been slowed due to insufficient means of storing enough portable energy. Therefore it is critical that efficient storage mediums be developed in order to transform abundant renewable energy into an on-demand source of power. Lithium (Li) ion batteries are seeing a stream of improvements as they are introduced into many consumer electronics, electric vehicles and aircraft, and medical devices. Li-ion batteries are well suited for portable applications because of their high energy-to-weight ratios, high energy densities, and reasonable life cycles. Current research into Li-ion batteries is focused on enhancing its energy density, and by changing the electrode materials, greater energy capacities can be realized. Silicon (Si) is a very attractive option because it has the highest known theoretical charge capacity. Current Si anodes, however, suffer from early capacity fading caused by pulverization from the stresses induced by large volumetric changes that occur during charging and discharging. An innovative system aimed at resolving this issue is being developed. This system incorporates a thin Si film bonded to an elastomeric substrate which is intended to provide the desired stress relief. Non-linear finite element simulations have shown that a significant amount of deformation can be accommodated until a critical threshold of Li concentration is reached; beyond which buckling is induced and a wavy structure appears. When compared to a similar system using rigid substrates where no buckling occurs, the stress is reduced by an order of magnitude, significantly prolonging the life of the Si anode. Thus the stress can be released at high Li-ion diffusion induced strains by buckling the Si thin film. Several aspects of this anode system have been analyzed including studying the effects of charge rate and thin film plasticity, and the results are compared with preliminary empirical measurements to

  7. Preparation and crystalline phase of a TiO2 porous film by anodic oxidation

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; TAO Jie; ZHANG Weiwei; TAO Haijun; WANG Ling

    2005-01-01

    Anatase titanium dioxide is an active photocatalyst, but it is difficult to immobilize on the substrate. A crystalline TiO2 porous film was prepared directly on the surface of pure titanium by anodic oxidation in this work. Constant voltage and constant current anodic oxidation were adopted with sulphuric acid used as the electrolyte, pure titanium as the anode and copper as the cathode. The morphology and structure of the porous film on the substrate were analyzed with the aid of Field Emission Scanning Electron Microscopy (FESEM) and X-ray Diffraction (XRD). The effects of the parameters of anodic oxidation (such as voltage, the concentration of sulphuric acid, anodization time and current density) on the aperture and the crystalline phase of the TiO2 porous film were systematically investigated. The results indicate that the increase of current density facilitates the augment of the aperture and the generation of anatase and rutile. In addition, the forming mechanism of anatase and rutile TiO2 porous films was discussed.

  8. Study on the Rare Earth Sealing Procedure of the Porous Film of Anodized 2024 Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The rare earth sealing procedure of the porous film of anodized aluminum alloy 2024 was studied with the fieldemission scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDS). The results show thatRE solution can form cerium oxide/hydroxides precipitation in the pores of the anodized coating at the beginning ofsealing. At the same time, the spherical deposits formed on the surface of the anodized coating created a barrierto the precipitation of RE solution in the pores. When the pore-structured anodizing film is covered all with thespherical deposits, RE conversion coating will form on the surface of the anodized coating. The reaction of thecoating formation was investigated by employing cyclic voltammetry. The results indicate that accelerator H2O2 actsas the source of O2 by carrying chemical reaction in course of coating formation. In the mean time, it maybe carrieselectrochemical reaction to generate alkaline condition to accelerate the coating formation. The porous structure ofthe film is beneficial to the precipitation of the cerium hydroxides film.

  9. Synthesis and properties of iridescent Zn-containing anodic aluminum oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Xiaoxuan; Sun, Huiyuan, E-mail: huiyuansun@126.com; Liu, Lihu; Hou, Xue; Liu, Huiyuan

    2015-07-01

    A simple method of fabricating Zn-containing anodic aluminum oxide films for multifunctional anticounterfeit technology is reported. The resulting membranes were characterized with UV–vis illumination studies, natural light illumination color experiments, and electron microscopy analysis. Deposition of Zn in the nanopore region can enhance the color saturation of the thin alumina film with different colors dramatically. Both the anodization time and etching time have great influence on the structural color. The mechanisms for the emergence of this phenomenon are discussed and theoretical analysis further demonstrates the experimental results. - Highlights: • Iridescent PAA@Zn nanocomposite films were successfully fabricated. • A simple organics-assisted method is applied to making a series of fancy and multicolor patterns. • The color varies with the angle of incidence of the light used to view the film as is expected with Bragg–Snell formula. • Such colored films could be used in multifunctional anti-counterfeiting applications.

  10. Hierarchically oriented macroporous anode-supported solid oxide fuel cell with thin ceria electrolyte film.

    Science.gov (United States)

    Chen, Yu; Zhang, Yanxiang; Baker, Jeffrey; Majumdar, Prasun; Yang, Zhibin; Han, Minfang; Chen, Fanglin

    2014-04-09

    Application of anode-supported solid oxide fuel cell (SOFC) with ceria based electrolyte has often been limited by high cost of electrolyte film fabrication and high electrode polarization. In this study, dense Gd0.1Ce0.9O2 (GDC) thin film electrolytes have been fabricated on hierarchically oriented macroporous NiO-GDC anodes by a combination of freeze-drying tape-casting of the NiO-GDC anode, drop-coating GDC slurry on NiO-GDC anode, and co-firing the electrolyte/anode bilayers. Using 3D X-ray microscopy and subsequent analysis, it has been determined that the NiO-GDC anode substrates have a porosity of around 42% and channel size from around 10 μm at the electrolyte side to around 20 μm at the other side of the NiO-GDC (away from the electrolyte), indicating a hierarchically oriented macroporous NiO-GDC microstructure. Such NiO-GDC microstructure shows a tortuosity factor of ∼1.3 along the thickness direction, expecting to facilitate gas diffusion in the anode during fuel cell operation. SOFCs with such Ni-GDC anode, GDC film (30 μm) electrolyte, and La0.6Sr0.4Co0.2Fe0.8O3-GDC (LSCF-GDC) cathode show significantly enhanced cell power output of 1.021 W cm(-2) at 600 °C using H2 as fuel and ambient air as oxidant. Electrochemical Impedance Spectroscopy (EIS) analysis indicates a decrease in both activation and concentration polarizations. This study has demonstrated that freeze-drying tape-casting is a very promising approach to fabricate hierarchically oriented porous substrate for SOFC and other applications.

  11. Material and Energy Flows in the Production of Cathode and Anode Materials for Lithium Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States); James, Christine [Michigan State Univ., East Lansing, MI (United States); Gaines, Linda [Argonne National Lab. (ANL), Argonne, IL (United States); Gallagher, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States); Dai, Qiang [Argonne National Lab. (ANL), Argonne, IL (United States); Kelly, Jarod C. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    The Greenhouse gases, Regulated Emissions and Energy use in Transportation (GREET) model has been expanded to include four new cathode materials that can be used in the analysis of battery-powered vehicles: lithium nickel cobalt manganese oxide (LiNi0.4Co0.2Mn0.4O2 [NMC]), lithium iron phosphate (LiFePO4 [LFP]), lithium cobalt oxide (LiCoO2 [LCO]), and an advanced lithium cathode (0.5Li2MnO3∙0.5LiNi0.44Co0.25Mn0.31O2 [LMR-NMC]). In GREET, these cathode materials are incorporated into batteries with graphite anodes. In the case of the LMR-NMC cathode, the anode is either graphite or a graphite-silicon blend. Lithium metal is also an emerging anode material. This report documents the material and energy flows of producing each of these cathode and anode materials from raw material extraction through the preparation stage. For some cathode materials, we considered solid state and hydrothermal preparation methods. Further, we used Argonne National Laboratory’s Battery Performance and Cost (BatPaC) model to determine battery composition (e.g., masses of cathode, anode, electrolyte, housing materials) when different cathode materials were used in the battery. Our analysis concluded that cobalt- and nickel-containing compounds are the most energy intensive to produce.

  12. Evolution of insoluble eutectic Si particles in anodic oxidation films during adipic-sulfuric acid anodizing processes of ZL114A aluminum alloys

    Science.gov (United States)

    Hua, Lei; Liu, Jian-hua; Li, Song-mei; Yu, Mei; Wang, Lei; Cui, Yong-xin

    2015-03-01

    The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were investigated by optical microscopy (OM) and scanning electron microscopy (SEM). The anodic oxidation was performed at 25°C and a constant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 μm. The interpore distance and the diameters of the major pores in the porous layer of the film were within the approximate ranges of 10-20 nm and 5-10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.

  13. Efficient photoelectrochemical water splitting over anodized p-type NiO porous films.

    Science.gov (United States)

    Hu, Chenyan; Chu, Kenneth; Zhao, Yihua; Teoh, Wey Yang

    2014-11-12

    NiO photocathodes were fabricated by alkaline etching-anodizing nickel foil in an organic-based electrolyte. The resulting films have a highly macroporous surface structure due to rapid dissolution of the oxide layer as it is formed during the anodization process. We are able to control the films' surface structures by varying the anodization duration and voltage. With an onset potential of +0.53 V versus the reversible hydrogen electrode (RHE), the photocurrent efficiency of the NiO electrodes showed dependencies on their surface roughness factor, which determines the extent of semiconductor-electrolyte interface and the associated quality of the NiO surface sites. A maximum incident photon-to-current conversion efficiency (IPCE(max)) of 22% was obtained from NiO film with a roughness factor of 8.4. Adding an Al2O3 blocking layer minimizes surface charge recombination on the NiO and hence increased the IPCE(max) to 28%. The NiO/Al2O3 films were extremely stable during photoelectrochemical water splitting tests lasting up to 20 h, continuously producing hydrogen and oxygen in the stoichiometric 2:1 ratio. The NiO/Al2O3 and NiO films fabricated using the alkaline anodization process produced 12 and 6 times as much hydrogen, respectively, as those fabricated using commercial NiO nanoparticles.

  14. Silicon oxide based high capacity anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Haixia; Han, Yongbong; Masarapu, Charan; Anguchamy, Yogesh Kumar; Lopez, Herman A.; Kumar, Sujeet

    2017-03-21

    Silicon oxide based materials, including composites with various electrical conductive compositions, are formulated into desirable anodes. The anodes can be effectively combined into lithium ion batteries with high capacity cathode materials. In some formulations, supplemental lithium can be used to stabilize cycling as well as to reduce effects of first cycle irreversible capacity loss. Batteries are described with surprisingly good cycling properties with good specific capacities with respect to both cathode active weights and anode active weights.

  15. Modified natural graphite as anode material for lithium ion batteries

    Science.gov (United States)

    Wu, Y. P.; Jiang, C.; Wan, C.; Holze, R.

    A concentrated nitric acid solution was used as an oxidant to modify the electrochemical performance of natural graphite as anode material for lithium ion batteries. Results of X-ray photoelectron spectroscopy, electron paramagnetic resonance, thermogravimmetry, differential thermal analysis, high resolution electron microscopy, and measurement of the reversible capacity suggest that the surface structure of natural graphite was changed, a fresh dense layer of oxides was formed. Some structural imperfections were removed, and the stability of the graphite structure increased. These changes impede decomposition of electrolyte solvent molecules, co-intercalation of solvated lithium ions and movement of graphene planes along the a-axis direction. Concomitantly, more micropores were introduced, and thus, lithium intercalation and deintercalation were favored and more sites were provided for lithium storage. Consequently, the reversible capacity and the cycling behavior of the modified natural graphite were much improved by the oxidation. Obviously, the liquid-solid oxidation is advantageous in controlling the uniformity of the products.

  16. Nanoporous silicon flakes as anode active material for lithium-ion batteries

    Science.gov (United States)

    Kim, Young-You; Lee, Jeong-Hwa; Kim, Han-Jung

    2017-01-01

    Nanoporous-silicon (np-Si) flakes were prepared using a combination of an electrochemical etching process and an ultra-sonication treatment and the electrochemical properties were studied as an anode active material for rechargeable lithium-ion batteries (LIBs). This fabrication method is a simple, reproducible, and cost effective way to make high-performance Si-based anode active materials in LIBs. The anode based on np-Si flakes exhibited a higher performances (lower capacity fade rate, stability and excellent rate capability at high C-rate) than the anode based on Si nanowires. The excellent performance of the np-Si flake anode was attributed to the hollowness (nanoporous structure) of the anode active material, which allowed it to accommodate a large volume change during cycling.

  17. [Hardened anodized aluminum as a replacement material for bracket manufacture].

    Science.gov (United States)

    Fischer-Brandies, H; Bönhoff, M

    1994-12-01

    Attention has been repeatedly drawn to the problem of corrosion and the risk of allergic reaction to nickel resulting from the use of stainless steel brackets. In the search for a suitable alternative, manufacturers have turned to thin coating technology using hardened anodized aluminium. Applying resistance to corrosion and abrasion as the criteria to be met, they have selected aluminium alloy type 6082 as the material of choice. Purpose of this study is to examine the physical suitability of this material. Using the above noted alloy, 60 prototype brackets were made with a hardened anodized surface. They were then subjected to the following 3 stress tests: first an abrasion test using a tooth polishing machine, second, a deformation test using a device designed to simulate torque movement, and, third, a corrosion test. The effects on the brackets resulting from the three types of stress were evaluated by light microscopy. A quantitative analysis of the corrosion test was performed by ICP spectrometry. The control group consisted of conventional stainless steel brackets. The light microscopic analysis revealed no evidence of surface damage or signs of deformation in the prototype brackets. The steel brackets, on the other hand, showed clear signs of wear and corrosion. The quantitative analysis of the corrosion solution revealed metallic ion wear of 1.75 ng x mm-2 x h-1 for the prototypes subjected to abrasion. The steel brackets showed at a factor of around 104.6 metallic ion wear of 183 ng x mm-2 x h-1. In addition to this, no Ni ions were found in the corrosion solution of the prototype brackets.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Lithium-Ion-Battery Anode Materials with Improved Capacity from a Metal-Organic Framework.

    Science.gov (United States)

    Lin, Xiao-Ming; Niu, Ji-Liang; Lin, Jia; Wei, Lei-Ming; Hu, Lei; Zhang, Gang; Cai, Yue-Peng

    2016-09-06

    We present a porous metal-organic framework (MOF) with remarkable thermal stability that exhibits a discharge capacity of 300 mAh g(-1) as an anode material for a lithium-ion battery. Pyrolysis of the obtained MOF gives an anode material with improved capacity (741 mAh g(-1)) and superior cyclic stability.

  19. Metal oxides and lithium alloys as anode materials for lithium-ion batteries

    CSIR Research Space (South Africa)

    Kebede, M

    2016-07-01

    Full Text Available -generation anode materials for lithium–ion batteries with high prospect of replacing graphite. Most of these anode materials have higher specific capacities between the range of 600-1000 mA h g(sup-1) compared with 340 mA h g(sup-1) of graphite. These high...

  20. Growth and etch rate study of low temperature anodic silicon dioxide thin films.

    Science.gov (United States)

    Ashok, Akarapu; Pal, Prem

    2014-01-01

    Silicon dioxide (SiO2) thin films are most commonly used insulating films in the fabrication of silicon-based integrated circuits (ICs) and microelectromechanical systems (MEMS). Several techniques with different processing environments have been investigated to deposit silicon dioxide films at temperatures down to room temperature. Anodic oxidation of silicon is one of the low temperature processes to grow oxide films even below room temperature. In the present work, uniform silicon dioxide thin films are grown at room temperature by using anodic oxidation technique. Oxide films are synthesized in potentiostatic and potentiodynamic regimes at large applied voltages in order to investigate the effect of voltage, mechanical stirring of electrolyte, current density and the water percentage on growth rate, and the different properties of as-grown oxide films. Ellipsometry, FTIR, and SEM are employed to investigate various properties of the oxide films. A 5.25 Å/V growth rate is achieved in potentiostatic mode. In the case of potentiodynamic mode, 160 nm thickness is attained at 300 V. The oxide films developed in both modes are slightly silicon rich, uniform, and less porous. The present study is intended to inspect various properties which are considered for applications in MEMS and Microelectronics.

  1. Growth and Etch Rate Study of Low Temperature Anodic Silicon Dioxide Thin Films

    Directory of Open Access Journals (Sweden)

    Akarapu Ashok

    2014-01-01

    Full Text Available Silicon dioxide (SiO2 thin films are most commonly used insulating films in the fabrication of silicon-based integrated circuits (ICs and microelectromechanical systems (MEMS. Several techniques with different processing environments have been investigated to deposit silicon dioxide films at temperatures down to room temperature. Anodic oxidation of silicon is one of the low temperature processes to grow oxide films even below room temperature. In the present work, uniform silicon dioxide thin films are grown at room temperature by using anodic oxidation technique. Oxide films are synthesized in potentiostatic and potentiodynamic regimes at large applied voltages in order to investigate the effect of voltage, mechanical stirring of electrolyte, current density and the water percentage on growth rate, and the different properties of as-grown oxide films. Ellipsometry, FTIR, and SEM are employed to investigate various properties of the oxide films. A 5.25 Å/V growth rate is achieved in potentiostatic mode. In the case of potentiodynamic mode, 160 nm thickness is attained at 300 V. The oxide films developed in both modes are slightly silicon rich, uniform, and less porous. The present study is intended to inspect various properties which are considered for applications in MEMS and Microelectronics.

  2. Material and Energy Flows in the Production of Cathode and Anode Materials for Lithium Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; James, Christine [Michigan State Univ., East Lansing, MI (United States). Chemical Engineering and Materials Science Dept.; Gaines, Linda G. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Gallagher, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States). Chemical Sciences and Engineering Division

    2014-09-30

    The Greenhouse gases, Regulated Emissions and Energy use in Transportation (GREET) model has been expanded to include four new cathode materials that can be used in the analysis of battery-powered vehicles: lithium nickel cobalt manganese oxide (LiNi0.4Co0.2Mn0.4O2 [NMC]), lithium iron phosphate (LiFePO4 [LFP]), lithium cobalt oxide (LiCoO2 [LCO]), and an advanced lithium cathode (0.5Li2MnO3∙0.5LiNi0.44Co0.25Mn0.31O2 [LMR-NMC]). In GREET, these cathode materials are incorporated into batteries with graphite anodes. In the case of the LMR-NMC cathode, the anode is either graphite or a graphite-silicon blend. This report documents the material and energy flows of producing each of these cathode and anode materials from raw material extraction through the preparation stage. For some cathode materials, we considered solid state and hydrothermal preparation methods. Further, we used Argonne National Laboratory’s Battery Performance and Cost (BatPaC) model to determine battery composition (e.g., masses of cathode, anode, electrolyte, housing materials) when different cathode materials were used in the battery. Our analysis concluded that cobalt- and nickel-containing compounds are the most energy intensive to produce.

  3. Layer-by-layer graphene/TCNQ stacked films as conducting anodes for organic solar cells.

    Science.gov (United States)

    Hsu, Chang-Lung; Lin, Cheng-Te; Huang, Jen-Hsien; Chu, Chih-Wei; Wei, Kung-Hwa; Li, Lain-Jong

    2012-06-26

    Large-area graphene grown by chemical vapor deposition (CVD) is a promising candidate for transparent conducting electrode applications in flexible optoelectronic devices such as light-emitting diodes or organic solar cells. However, the power conversion efficiency (PCE) of the polymer photovoltaic devices using a pristine CVD graphene anode is still not appealing due to its much lower conductivity than that of conventional indium tin oxide. We report a layer-by-layer molecular doping process on graphene for forming sandwiched graphene/tetracyanoquinodimethane (TCNQ)/graphene stacked films for polymer solar cell anodes, where the TCNQ molecules (as p-dopants) were securely embedded between two graphene layers. Poly(3-hexylthiophene)/phenyl-C61-butyric acid methyl ester (P3HT/PCBM) bulk heterojunction polymer solar cells based on these multilayered graphene/TCNQ anodes are fabricated and characterized. The P3HT/PCBM device with an anode structure composed of two TCNQ layers sandwiched by three CVD graphene layers shows optimum PCE (∼2.58%), which makes the proposed anode film quite attractive for next-generation flexible devices demanding high conductivity and transparency.

  4. Trends in Catalytic Activity for SOFC Anode materials

    DEFF Research Database (Denmark)

    Rossmeisl, Jan; Bessler, W. G.

    2008-01-01

    for solid oxide fuel cell (SOFC) anodes. The reaction energies along the hydrogen oxidation pathway were quantified for both, oxygen spillover and hydrogen spillover mechanisms at the three-phase boundary. The ab initio results are compared to previously-obtained experimental anode activities measured...

  5. Optical and magnetic properties of porous anodic alumina films embedded with Co nanowires

    Institute of Scientific and Technical Information of China (English)

    Zhang Jing-Jing; Li Zi-Yue; Zhang Hui-Min; Hou Xue; Sun Hui-Yuan

    2013-01-01

    A simple method to tune the optical properties of porous anodic alumina (PAA) films embedded with Co nanowires (PAA@Co nanocomposite films) is reported in this paper.The films exhibit vivid structural colors and magnetic properties.The optical properties of the films can be effectively tuned by adjusting the thickness of the PAA template.The deposition of Co nanowires greatly increases the color saturation of the PAA films.The theoretical results of the changes in structural color according to the Bragg-Snell formula are consistent with the experimental results.PAA@Co films can be used in many areas,including decoration,display,and multifunctional anti-counterfeiting applications.

  6. Dead lithium phase investigation of Sn-Zn alloy as anode materials for lithium ion battery

    Institute of Scientific and Technical Information of China (English)

    HUANG ZhaoWen; HU SheJun; HOU XianHua; RU Qiang; YU HongWen; ZHAO LingZhi; LI WeiShan

    2009-01-01

    In this work, based on First-principle plane wave pseudo-potential method, we have carried out an in-depth study on the possible dead lithium phase of Sn-Zn alloy as anode materials for lithium ion batteries. Through investigation, we found that the phases LixSn4Zn4(x = 2, 4, 6, 8) contributed to reversible capacity, while the phases LixSn4Zns-(x-4)(x = 4.74, 7.72) led to capacity loss due to high formation energy, namely, they were the dead lithium phases during the charge/discharge process. And we come up with a new idea that stable lithium alloy phase with high lithiation formation energy (dead lithium phase) can also result in high loss of active lithium ion, besides the traditional expression that the formation of solid electrolyte interface film leads to high capacity loss.

  7. Bimodal spatial distribution of pores in anodically oxidized aluminum thin films

    Science.gov (United States)

    Behnke, J. F.; Sands, T.

    2000-12-01

    Though porous anodic aluminum oxide has been the subject of considerable research since the 1950s, little attention has been devoted to the characterization of the self-organization of the pore structures, and fewer of these studies have focused on anodization of thin films. The degree to which these structures self-organize, however, could play a vital role in future applications of porous anodic aluminum oxide. In this study a model is developed to describe pore ordering in thin anodized aluminum films. The model is based on a radial distribution function approach to describe the interpore spacings. Idealized one-dimensional and two-dimensional (2D) radial distribution functions are combined by linear superposition to approximate experimental radial distribution functions. Using these radial distribution functions, an order parameter is developed and an improved definition of pore spacing is constructed. This method confirms that the oxide initially forms with a highly frustrated porous structure and reorganizes toward greater 2D order as the oxide grows into the film.

  8. Anodic Stripping Voltametry at Mercury Film Deposited on Ultrasmall Carbon Ring Electrodes

    Science.gov (United States)

    1990-11-05

    a b. OFFICE OF NAVAL RESEARCH o GRANT or CONTRACT N00014-90-J-1161 R & T Code 4133030 Technical Report No. 001 Anodic Stripping Voltametry at Mercury...13 REPORT TYPE AND DATES COVERED lNovember 5,_ _90 Technical 4 TITLE AND SUBTITLE 5. FUNDING NUMBERS Anodic Stripping Voltametry at Mercury Film...where high scan rate cyclic vrhrnm-try is possilble. In fact, scan rates above one million V s - ’ have been demonstrated [8]. n cnf i s, t low scan

  9. Synthesis and characterization of nanoporous anodic oxide film on aluminum in H3PO4 + KMnO4 electrolyte mixture at different anodization conditions

    Science.gov (United States)

    Verma, Naveen; Jindal, Jitender; Singh, Krishan Chander; Mari, Bernabe

    2016-04-01

    The micro structural properties of nanoporous anodic oxide film formed in H3PO4 were highly influenced by addition of a low concentration of KMnO4 (0.0005 M) in 1 M H3PO4 solution. The KMnO4 as additive enhanced the growth rate of oxide film formation as well as thickness of pore walls. Furthermore the growth rate was found increased with increase in applied current density. The increase in temperature and lack of stirring during anodization causes the thinness of pore wall which leads to increase in pore volume. With the decrease in concentration of H3PO4 in anodizing electrolyte from 1M to 0.3 M, keeping all other conditions constant, the decrease in porosity was observed. This might be due to the dissolution of aluminium oxide film in highly concentrated acidic solution.

  10. The Effect of Anodic Oxide Films on the Nickel-Aluminum Reaction in Aluminum Braze Sheet

    Science.gov (United States)

    Tadgell, Colin A.; Wells, Mary A.; Corbin, Stephen F.; Colley, Leo; Cheadle, Brian; Winkler, Sooky

    2017-03-01

    The influence of an anodic oxide surface film on the nickel-aluminum reaction at the surface of aluminum brazing sheet has been investigated. Samples were anodized in a barrier-type solution and subsequently sputtered with nickel. Differential scanning calorimetry (DSC) and metallography were used as the main investigative techniques. The thickness of the anodic film was found to control the reaction between the aluminum substrate and nickel coating. Solid-state formation of nickel-aluminum intermetallic phases occurred readily when a relatively thin oxide film (13 to 25 nm) was present, whereas intermetallic formation was suppressed in the presence of thicker oxides ( 60 nm). At an intermediate oxide film thickness of 35 nm, the Al3Ni phase formed shortly after the initiation of melting in the aluminum substrate. Analysis of DSC traces showed that formation of nickel-aluminum intermetallic phases changed the melting characteristics of the aluminum substrate, and that the extent of this change can be used as an indirect measure of the amount of nickel incorporated into the intermetallic phases.

  11. Interfacial phenomena in electric field-assisted anodic bonding of Kovar/Al film-glass

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Anodic bonding of glass to Kovar alloy coated with Al film (Glass-Al film/Kovar) was performed in the temperature range of 513~713?K under the static electric voltage of 500?V in order to investigate the interfacial phenomena of Al-glass joint. The results reveal that Na and K ions within the glass are displaced by the applied field from the anode-side surface of the glass to form depletion layers of them. The K ion depletion layer is narrow and followed by a K pile-up layer, and both the two layers are formed within the Na depletion layer. The width of the Na and K depletion layers is increased with increasing bonding temperature and time. The activation energies for the growth of both depletion layers were close to that for Na diffusion in the glass. TEM observations reveal that Al film coated at the surface of Kovar alloy is oxidized to amorphous Al2O3 containing a few of Fe, Ni and Co by oxygen ions from the glass drifted by high electric field during bonding. The amount of Fe ions diffusing into the glass adjacent to the anode is significantly low due to the presence of Al film between Kovar alloy and the glass. As a result, the amorphous reaction layer of Fe-Si-O in the glass near the interface is avoided which is formed in Kovar-glass joints.

  12. Tricolor microcavity OLEDs based on P-nc-Si:H films as the complex anodes

    Institute of Scientific and Technical Information of China (English)

    Li Yang; Liu Xingyuan; Wu Chunya; Meng Zhiguo; Wang Yi; Xiong Shaozhen

    2009-01-01

    A P+-nc-Si:H film (boron-doped nc-Si:H thin film) was used as a complex anode of an OLED. As an ideal candidate for the composite anode, the P+-nc-Si:H thin film has a good conductivity with a high work function (~5.7 eV) and outstanding optical properties of high reflectivity, transmission, and a very low absorption. As a result, the combination of the relatively high reflectivity of a P+-nc-Si:H film/ITO complex anode with the very high reflectivity of an Al cathode could form a micro-cavity structure with a certain Q to improve the efficiency of the OLED fabricated on it. An RGB pixel generated by microcavity OLEDs is beneficial for both the reduction of the light loss and the improvement of the color purity and the efficiency. The small molecule Alq would be useful for the emitting light layer (EML) of the MOLED, and the P+-nc-Si film would be used as a complex anode of the MOLED, whose configuration can be constructed as Glass/LTO/P+-nc-Si:H/ITO/MoO3/NPB/Alq/LiF/Al. By adjusting the thickness of the organic layer NPB/Alq, the optical length of the microcavity and the REB colors of the device can be obtained. The peak wavelengths of an OLED are located at 486, 550, and 608 nm, respectively.The CIE coordinates are (0.21,0.45), (0.33,0.63), and (0.54,0.54), and the full widths at half maximum (FWHM)are 35, 32, and 39 nm for red, green, and blue, respectively.

  13. Tremella-like Molybdenum Dioxide as an Anode Material for Lithium ion Battery

    Institute of Scientific and Technical Information of China (English)

    L.C.Yang; Q.S.Gao; Y.H.Zhang; Y.Tang; Y.P.Wu

    2007-01-01

    1 Results Molybdenum dioxide, with excellent chemical and physical properties, has been widely used in various fields[1]. As an anode material for lithium ion battery, it exhibits higher capacity than commercial carbonaceous materials, and proper morphology, structure and particle size are necessary for MoO2 to be employed as an anode material for lithium ion battery[2].We have successfully obtained tremella-like structure self-assembled with hexagonal MoO2 nanosheets via hydrothermal method using ethyl...

  14. Si-Based Anode Materials for Li-Ion Batteries:A Mini Review

    Institute of Scientific and Technical Information of China (English)

    Delong Ma; Zhanyi Cao; Anming Hu

    2014-01-01

    Si has been considered as one of the most attractive anode materials for Li-ion batteries (LIBs) because of its high gravimetric and volumetric capacity. Importantly, it is also abundant, cheap, and environmentally benign. In this review, we summarized the recent progress in developments of Si anode materials. First, the electrochemical reaction and failure are outlined, and then, we summarized various methods for improving the battery performance, including those of nanostructuring, alloying, forming hierarchic structures, and using suitable binders. We hope that this review can be of benefit to more intensive investigation of Si-based anode materials.

  15. Metal-insulator transition in nanocomposite VO{sub x} films formed by anodic electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Tsui, Lok-kun; Lu, Jiwei; Zangari, Giovanni, E-mail: gz3e@virginia.edu [Department of Materials Science and Engineering, University of Virginia, 395 McCormick Rd., Charlottesville, Virginia 22904 (United States); Hildebrand, Helga; Schmuki, Patrik [Department for Materials Science LKO, University of Erlangen-Nuremberg, Martensstr. 7, D-91058 Erlangen (Germany)

    2013-11-11

    The ability to grow VO{sub 2} films by electrochemical methods would open a low-cost, easily scalable production route to a number of electronic devices. We have synthesized VO{sub x} films by anodic electrodeposition of V{sub 2}O{sub 5}, followed by partial reduction by annealing in Ar. The resulting films are heterogeneous, consisting of various metallic/oxide phases and including regions with VO{sub 2} stoichiometry. A gradual metal insulator transition with a nearly two order of magnitude change in film resistance is observed between room temperature and 140 °C. In addition, the films exhibit a temperature coefficient of resistance of ∼ −2.4%/ °C from 20 to 140 °C.

  16. Calcination/acid-activation treatment of an anodic oxidation TiO2/Ti film catalyst

    Institute of Scientific and Technical Information of China (English)

    YAO Zhongping; JIANG Yanli; JIANG Zhaohua; ZHU Hongkui; BAI Xuefeng

    2009-01-01

    The aim of this work was to investigate the effects of calcination/acid-activation on the composition, structure, and photocatalytic (PC) re-duction property of an anodic oxidation TiO2/Ti film catalyst. The surface morphology and phase composition were examined by scanning electron microscopy and X-ray diffraction. The catalytic property of the film catalysts was evaluated through the removal rate of potassium chromate during the PC reduction process. The results showed that the film catalysts were composed of anatase and mtile TiO2 with a mi-cro-porous surface structure. The calcination treatment increased the content of TiO2 in the film, changed the relative ratio of anatase and rutile TiO2, and decreased the size of the micro pores of the film cat.a/ysts. The removal rate of potassium chromate was related to the tech-nique parameters of calcination/acid-activation treatment. When the anodic oxidation TiO2Ti film catalyst was calcined at 873 K for 30 min and then acid-activated in the concentrated H2SO4 for 60 min, it presented the highest catalytic property, with the removal rate of potassium chromate of 96.3% during the PC reduction process under the experimental conditions.

  17. Growth of anodic films on compound semiconductor electrodes: InP in aqueous (NH sub 4) sub 2 S

    CERN Document Server

    Buckley, D N

    2002-01-01

    Film formation on compound semiconductors under anodic conditions is discussed. The surface properties of InP electrodes were examined following anodization in a (NH sub 4) sub 2 S electrolyte. The observation of a current peak in the cyclic voltammetric curve was attributed to selective etching of the substrate and a film formation process. AFM images of samples anodized in the sulfide solution revealed surface pitting. Thicker films formed at higher potentials exhibited extensive cracking as observed by optical and electron microscopy, and this was explicitly demonstrated to occur ex situ rather than during the electrochemical treatment. The composition of the thick film was identified as In sub 2 S sub 3 by EDX and XPS. The measured film thickness varies linearly with the charge passed, and comparison between experimental thickness measurements and theoretical estimates for the thickness indicate a porosity of over 70 %. Cracking is attributed to shrinkage during drying of the highly porous film and does n...

  18. Effects of thermal treatment on the anodic growth of tungsten oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Chai, Y., E-mail: yqchai85@gmail.com; Tam, C.W.; Beh, K.P.; Yam, F.K.; Hassan, Z.

    2015-08-03

    This work reports the investigation of the effects of thermal treatment on anodic growth tungsten oxide (WO{sub 3}). The increase of the thermal treatment temperature above 400 °C significantly influences WO{sub 3} film where high porosity structure reduces to more compact film. As-grown film is amorphous, which transforms to monoclinic/orthorhombic phase upon annealing at 300–600 °C. With the reducing of porous structure, preferential growth of (002) plane shifts to (020) plane at 600 °C with more than twentyfold increase of peak's intensity compared to the film annealed at 500 °C. Films annealed at low thermal treatment show better ion intercalation and reversibility during electrochemical measurements; however, it has larger optical band gap. Photoelectrochemical measurement reveals that film annealed at 400 °C exhibits the best photocatalytic performance among the films annealed at 300–600 °C. - Highlights: • Porosity of the WO{sub 3} reduces as annealing temperature increases above 400 °C. • As-grown film is amorphous which transforms to monoclinic/orthorhombic upon annealing. • As-grown film shows better ion intercalation in electrochemical process. • Optical band gap of WO{sub 3} reduces as the annealing temperature increases. • Film annealed at 400 °C exhibits best photocatalytic performance.

  19. Growth Kinetics of Anodic Oxide Films Formed on Zircaloy-2 in Various Electrolytes

    Directory of Open Access Journals (Sweden)

    V. Jeevana Jyothi

    2009-01-01

    Full Text Available The Kinetics of anodic oxidation of zircaloy-2 have been studied at current densities ranging from 4 to 12 mA cm-2 at room temperature in order to investigate the dependence of ionic current density on the field across the oxide film. Thickness of the anodic films was estimated from capacitance data. The formation rate, current efficiency and differential field were found to increase with increase in the ionic current density for zircaloy-2. Plots of logarithm of formation rate vs. logarithm of current density is fairly linear. From linear plots of logarithm of ionic current density vs. differential field and applying the Cabrera - Mott theory, the half - jump distance (a and height of energy barrier (W were deduced.

  20. Cycling behaviour of sponge-like nanostructured ZnO as thin-film Li-ion battery anodes

    Energy Technology Data Exchange (ETDEWEB)

    Garino, Nadia, E-mail: nadia.garino@iit.it [Center for Space Human Robotics @Polito, Istituto Italiano di Tecnologia, Corso Trento, 21, 10129 Turin (Italy); Lamberti, Andrea; Gazia, Rossana; Chiodoni, Angelica [Center for Space Human Robotics @Polito, Istituto Italiano di Tecnologia, Corso Trento, 21, 10129 Turin (Italy); Gerbaldi, Claudio, E-mail: claudio.gerbaldi@polito.it [Center for Space Human Robotics @Polito, Istituto Italiano di Tecnologia, Corso Trento, 21, 10129 Turin (Italy); GAME Lab, Department of Applied Science and Technology – DISAT, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy)

    2014-12-05

    Highlights: • Zn is thermally oxidized in ambient air to obtain sponge-like ZnO film. • Polycrystalline, transparent, porous thin film is obtained. • Film exhibits stabile specific capacity (∼300 mAh g{sup −1}) after prolonged cycling. • Sponge-like ZnO film shows promising prospects as Li-ion battery anode. - Abstract: Single phase wurtzitic porous ZnO thin films are obtained by a simple two-step method, involving the sputtering deposition of a sponge-like metallic Zn layer, followed by a moderately low temperature treatment for the complete zinc oxidation. Thanks to its 3D nanostructuration, the superimposition of small branches able to grow in length almost isotropically and forming a complex topography, sponge-like ZnO can combine the fast transport properties of one dimensional material and the high surface area usually provided by nanocrystalline electrodes. When galvanostatically tested in lithium cell, after the initial decay, it can provide an almost stable specific capacity higher than 50 μAh cm{sup −2} after prolonged cycling at estimated 0.7 C, with very high Coulombic efficiency.

  1. An anode with aluminum doped on zinc oxide thin films for organic light emitting devices [rapid communication

    Science.gov (United States)

    Xu, Denghui; Deng, Zhenbo; Xu, Ying; Xiao, Jing; Liang, Chunjun; Pei, Zhiliang; Sun, Chao

    2005-10-01

    Doped zinc oxides are attractive alternative materials as transparent conducting electrode because they are nontoxic and inexpensive compared with indium tin oxide (ITO). Transparent conducting aluminum-doped zinc oxide (AZO) thin films have been deposited on glass substrates by DC reactive magnetron sputtering method. Films were deposited at a substrate temperature of 150 °C in 0.03 Pa of oxygen pressure. The electrical and optical properties of the film with the Al-doping amount of 2 wt% in the target were investigated. For the 300-nm thick AZO film deposited using a ZnO target with an Al content of 2 wt%, the lowest electrical resistivity was 4×10Ωcm and the average transmission in the visible range 400 700 nm was more than 90%. The AZO film was used as an anode contact to fabricate organic light-emitting diodes. The device performance was measured and the current efficiency of 2.9 cd/A was measured at a current density of 100 mA/cm2.

  2. Surface analysis of films formed on a zinc anode in a Zn Ni electroplating bath

    Science.gov (United States)

    Velichenko, A. B.; Portillo, J.; Sarret, M.; Muller, C.

    1999-06-01

    The films obtained on a zinc anode in a zinc-nickel electrolyte under open circuit conditions were characterized by XRD, SEM and XPS. The film consisted of metallic zinc and nickel and zinc dissolution products, showing a three-layers structure. In the first layer (the film|electrolyte interface) zinc was always present as Zn(OH) 2 with some adsorbed water. The second layer was a transition region where the content of metallic zinc increased and that of oxygen decreased until a constant composition was reached. The third layer was located in the bulk film and it was mainly composed of α-phase Zn-Ni alloy doped with zinc hydroxide or simonkolleite, depending on the time.

  3. An investigation of anode and cathode materials in photomicrobial fuel cells.

    Science.gov (United States)

    Schneider, Kenneth; Thorne, Rebecca J; Cameron, Petra J

    2016-02-28

    Photomicrobial fuel cells (p-MFCs) are devices that use photosynthetic organisms (such as cyanobacteria or algae) to turn light energy into electrical energy. In a p-MFC, the anode accepts electrons from microorganisms that are either growing directly on the anode surface (biofilm) or are free floating in solution (planktonic). The nature of both the anode and cathode material is critical for device efficiency. An ideal anode is biocompatible and facilitates direct electron transfer from the microorganisms, with no need for an electron mediator. For a p-MFC, there is the additional requirement that the anode should not prevent light from perfusing through the photosynthetic cells. The cathode should facilitate the rapid reaction of protons and oxygen to form water so as not to rate limit the device. In this paper, we first review the range of anode and cathode materials currently used in p-MFCs. We then present our own data comparing cathode materials in a p-MFC and our first results using porous ceramic anodes in a mediator-free p-MFC.

  4. Facile synthesis of reduced graphene oxide-porous silicon composite as superior anode material for lithium-ion battery anodes

    Science.gov (United States)

    Jiao, Lian-Sheng; Liu, Jin-Yu; Li, Hong-Yan; Wu, Tong-Shun; Li, Fenghua; Wang, Hao-Yu; Niu, Li

    2016-05-01

    We report a new method for synthesizing reduced graphene oxide (rGO)-porous silicon composite for lithium-ion battery anodes. Rice husks were used as a as a raw material source for the synthesis of porous Si through magnesiothermic reduction process. The as-obtained composite exhibits good rate and cycling performance taking advantage of the porous structure of silicon inheriting from rice husks and the outstanding characteristic of graphene. A considerably high delithiation capacity of 907 mA h g-1 can be retained even at a rate of 16 A g-1. A discharge capacity of 830 mA h g-1 at a current density of 1 A g-1 was delivered after 200 cycles. This may contribute to the further advancement of Si-based composite anode design.

  5. Durability Prediction of Solid Oxide Fuel Cell Anode Material under Thermo-Mechanical and Fuel Gas Contaminants Effects

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Gulfam; Guo, Hua; Kang , Bruce S.; Marina, Olga A.

    2011-01-10

    Solid Oxide Fuel Cells (SOFCs) operate under harsh environments, which cause deterioration of anode material properties and service life. In addition to electrochemical performance, structural integrity of the SOFC anode is essential for successful long-term operation. The SOFC anode is subjected to stresses at high temperature, thermal/redox cycles, and fuel gas contaminants effects during long-term operation. These mechanisms can alter the anode microstructure and affect its electrochemical and structural properties. In this research, anode material degradation mechanisms are briefly reviewed and an anode material durability model is developed and implemented in finite element analysis. The model takes into account thermo-mechanical and fuel gas contaminants degradation mechanisms for prediction of long-term structural integrity of the SOFC anode. The proposed model is validated experimentally using a NexTech ProbostatTM SOFC button cell test apparatus integrated with a Sagnac optical setup for simultaneously measuring electrochemical performance and in-situ anode surface deformation.

  6. Silver: high performance anode for thin film lithium ion batteries

    Science.gov (United States)

    Taillades, G.; Sarradin, J.

    Among metals and intermetallic compounds, silver exhibits a high specific capacity according to the formation of different Ag-Li alloys (up to AgLi 12) in a very low voltage range versus lithium (0.250-0 V). Electrochemical results including Galvanostatic Intermittent Titration Technique (GITT) as well as cycling behaviour experiments confirmed the interesting characteristics of silver thin film electrodes prepared by radio frequency (r.f.) sputtering. XRD patterns recorded at different electrochemical stages of the alloying/de-alloying processes showed the complexity of the silver-lithium system under dynamic conditions. Cycling life depends on several parameters and particularly of the careful choice of cut-off voltages. In very well monitored conditions, galvanostatic cycles exhibited flat reversible plateaus with a minimal voltage value (0.050 V) between charge and discharge, a feature of great interest in the use of an electrode. The first results of a lithium ion battery with both silver and LiMn 1.5Ni 0.5O 4 thin films are presented.

  7. Novel Ceramic Materials for Polymer Electrolyte Membrane Water Electrolysers' Anodes

    DEFF Research Database (Denmark)

    Polonsky, J.; Bouzek, K.; Prag, Carsten Brorson

    2012-01-01

    Tantalum carbide was evaluated as a possible new support for the IrO2 for use in anodes of polymer electrolyte membrane water electrolysers. A series of supported electrocatalysts varying in mass content of iridium oxide was prepared. XRD, powder conductivity measurements and cyclic and linear sw...

  8. Selection of Anodic Material Used in Electrolytic Process for Producing Hypophosphorous Acid

    Institute of Scientific and Technical Information of China (English)

    Fu Sheng WANG; Bing Kui SONG; Xiao Li HAN; Bao Gui ZHANG

    2004-01-01

    Black lead, Ti-Ru and Ti-PbO2 were used as anode and stainless steel was used as cathode.The electrolytic process of producing hypophosphorous acid with four-compartment electrodialytic cell was studied. The comparison of some factors, such as anodic voltage, product concentration and current efficiency, of black lead, Ti-Ru, and Ti-PbO2 electrodes was conducted. As a result, the Ti-PbO2 electrode is the optimal anode material used, it can be in electrolytic process for producing hypophosphorous acid.

  9. Synthesis of Coral-Like Tantalum Oxide Films via Anodization in Mixed Organic-Inorganic Electrolytes

    Science.gov (United States)

    Yu, Hongbin; Zhu, Suiyi; Yang, Xia; Wang, Xinhong; Sun, Hongwei; Huo, Mingxin

    2013-01-01

    We report a simple method to fabricate nano-porous tantalum oxide films via anodization with Ta foils as the anode at room temperature. A mixture of ethylene glycol, phosphoric acid, NH4F and H2O was used as the electrolyte where the nano-porous tantalum oxide could be synthesized by anodizing a tantalum foil for 1 h at 20 V in a two–electrode configuration. The as-prepared porous film exhibited a continuous, uniform and coral-like morphology. The diameters of pores ranged from 30 nm to 50 nm. The pores interlaced each other and the depth was about 150 nm. After calcination, the as-synthesized amorphous tantalum oxide could be crystallized to the orthorhombic crystal system. As observed in photocatalytic experiments, the coral-like tantalum oxide exhibited a higher photocatalytic activity for the degradation of phenol than that with a compact surface morphology, and the elimination rate of phenol increased by 66.7%. PMID:23799106

  10. Synthesis of coral-like tantalum oxide films via anodization in mixed organic-inorganic electrolytes.

    Directory of Open Access Journals (Sweden)

    Hongbin Yu

    Full Text Available We report a simple method to fabricate nano-porous tantalum oxide films via anodization with Ta foils as the anode at room temperature. A mixture of ethylene glycol, phosphoric acid, NH4F and H2O was used as the electrolyte where the nano-porous tantalum oxide could be synthesized by anodizing a tantalum foil for 1 h at 20 V in a two-electrode configuration. The as-prepared porous film exhibited a continuous, uniform and coral-like morphology. The diameters of pores ranged from 30 nm to 50 nm. The pores interlaced each other and the depth was about 150 nm. After calcination, the as-synthesized amorphous tantalum oxide could be crystallized to the orthorhombic crystal system. As observed in photocatalytic experiments, the coral-like tantalum oxide exhibited a higher photocatalytic activity for the degradation of phenol than that with a compact surface morphology, and the elimination rate of phenol increased by 66.7%.

  11. Carbon Materials Metal/Metal Oxide Nanoparticle Composite and Battery Anode Composed of the Same

    Science.gov (United States)

    Hung, Ching-Cheh (Inventor)

    2006-01-01

    A method of forming a composite material for use as an anode for a lithium-ion battery is disclosed. The steps include selecting a carbon material as a constituent part of the composite, chemically treating the selected carbon material to receive nanoparticles, incorporating nanoparticles into the chemically treated carbon material and removing surface nanoparticles from an outside surface of the carbon material with incorporated nanoparticles. A material making up the nanoparticles alloys with lithium.

  12. Synthesis and characterization of atomic layer deposited titanium nitride thin films on lithium titanate spinel powder as a lithium-ion battery anode

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, Mark Q.; Wheeler, M. Clayton [Department of Chemical and Biological Engineering, University of Maine, 5737 Jenness Hall, Orono, ME 04469 (United States); Trebukhova, Svetlana A.; Ravdel, Boris; DiCarlo, Joseph [Yardney Technical Products/Lithion Inc., Pawcatuck, CT 06379 (United States); Tripp, Carl P. [Laboratory for Surface Science and Technology (LASST), 5708 ESRB-Barrows, Orono, ME 04469 (United States); Department of Chemistry, University of Maine, Orono, ME 04469 (United States); DeSisto, William J. [Department of Chemical and Biological Engineering, University of Maine, 5737 Jenness Hall, Orono, ME 04469 (United States); Laboratory for Surface Science and Technology (LASST), 5708 ESRB-Barrows, Orono, ME 04469 (United States)

    2007-02-25

    Lithium titanate spinel (Li{sub 4}Ti{sub 5}O{sub 12}, or LTS) is receiving consideration as a nanopowder anode material for use in lithium-ion batteries. LTS has more positive working potential than traditional graphite anodes, and it does not react with electrolyte components. However, the main drawback of LTS powder is its poor interparticle electronic conductance that reduces the high-rate ability of the electrode. To improve this we have coated the surface of the LTS powder with a titanium nitride layer by atomic layer deposition (ALD). In situ infrared spectroscopy studies were conducted to confirm the attachment of the titanium precursor. The nitrogen content of films was measured by total nitrogen content testing. Transmission electron microscopy (TEM) micrographs confirmed the formation of a thin titanium nitride film around LTS particles by ALD. Finally, lithium cells with electrodes made of original and modified LTS nanopowders were assembled and tested. (author)

  13. Decomposition of ethylene carbonate on electrodeposited metal thin film anode

    Energy Technology Data Exchange (ETDEWEB)

    Bridel, Jean-Sebastien; Grugeon, Sylvie; Laruelle, Stephane; Tarascon, Jean-Marie [Laboratoire de Reactivite et Chimie des Solides, Universite de Picardie Jules Verne CNRS (UMR-6007), Faculte des Sciences, 33 rue Saint-Leu 80039, Amiens Cedex (France); Hassoun, Jusef; Reale, Priscilla; Scrosati, Bruno [Chemistry Department, University of Rome ' ' La Sapienza' ' , 00185 Roma (Italy)

    2010-04-02

    Metals capable of forming alloys with Li are of great interest as an alternative to present carbon electrodes, hence the importance of knowing their interactions with electrolytes is necessary. Herein we report further on the high-voltage extra irreversibility of Sn electrodeposited thin films vs. Li in EC-DMC 1 M LiPF{sub 6} electrolytes. We show that this high-voltage irreversibility is strongly dependent upon the electrolyte composition as demonstrated by its disappearance in EC-free electrolytes. This finding coupled with IR spectroscopy measurements provides direct evidence for the tin-driven catalytic degradation of EC during the discharge of Sn/Li cells. From an electrochemical survey of various metals, capable of alloying with Li, we found that Bi and Pb behaved like Sn while Si and Sb did not act as catalysts towards EC degradation. A rationale for such behaviour is proposed, a procedure to bypass EC degradation with the addition of VC is presented, and an explanation for the non-observance of catalytic-driven EC degradation for Sn/C composites is provided. (author)

  14. Electrocatalytic Materials and Techniques for the Anodic Oxidation of Various Organic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Treimer, Stephen Everett [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    The focus of this thesis was first to characterize and improve the applicability of Fe(III) and Bi(V) doped PbO2 film electrodes for use in anodic O-transfer reactions of toxic and waste organic compounds, e.g. phenol, aniline, benzene, and naphthalene. Further, they investigated the use of alternative solution/electrode interfacial excitation techniques to enhance the performance of these electrodes for remediation and electrosynthetic applications. Finally, they have attempted to identify a less toxic metal oxide film that may hold promise for future studies in the electrocatalysis and photoelectrocatalysis of O-transfer reactions using metal oxide film electrodes.

  15. A disordered carbon as a novel anode material in lithium-ion cells

    Energy Technology Data Exchange (ETDEWEB)

    Bonino, F.; Brutti, S.; Reale, P.; Scrosati, B. [Dipartimento di Chimica, Universita ' ' La Sapienza' ' , I-00185 Rome (Italy); Gherghel, L.; Wu, J.; Muellen, K. [Max Planck Institute for Polymer Research, Ackermannweg 10, D-55124 Mainz (Germany)

    2005-03-22

    The electrochemical behavior of a disordered carbon used as the anode in a lithium battery has been tested. The characteristics of this carbon, especially its specific capacity and cycle life, are such that it is a potentially unique, high-performance anode material for new types of lithium-ion batteries. The Figure shows the specific capacity versus cycle number of the disordered carbon electrode in a lithium-ion cell. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  16. Electron microscopic studies of anodic oxide films on the AZ91HP alloy

    Directory of Open Access Journals (Sweden)

    D. Peixoto Barbosa

    2003-01-01

    Full Text Available A Mg-9wt.Al-1wt.%Zn-alloy was anodized up to 90 V with constant current/constant voltage in an electrolyte which contained the compounds of the HAE-process (KOH, Al(OH3, KF, Na3PO4 and KMnO4. Electron microscopic examinations revealed a highly porous and irregular film structure. The distribution of the elements in the film was measured with energy dispersive spectrometry on specimens prepared in cross section for the transmission electron microscope. The main characteristic found was a fluoride-enriched zone of about 100 nm thickness at the metal / film interface. Practically no manganese from the permanganate was detected in this fluoride-enriched zone.

  17. Sn–Al core–shell nanocomposite as thin film anode for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Lin; Zhang, Kai; Tao, Zhanliang, E-mail: taozhl@nankai.edu.cn; Chen, Jun

    2015-09-25

    Highlights: • Sn (core)–Al (shell) nanocomposite thin film is prepared by magnetron sputtering method. • The effect of Al on the structure and electrochemical performance has been investigated. • Improved electrochemical performance is obtained. - Abstract: In this paper, we report on the preparation of Sn (core)–Al (shell) nanocomposite thin films by co-sputtering Sn target and Al target, and their application as anode of lithium-ion batteries. Instrumental analyses of X-ray diffraction, energy dispersive X-ray analysis, scanning electron microscopy, and transmission electron microscope have been used to characterize the structure and morphology. The results reveal that the thin film is composed of core–shell structure with Sn nanoparticle core and Al amorphous shell. Furthermore, measurements of charge–discharge, cyclic voltammetry and electrochemical impedance spectroscopy have been employed to characterize the electrochemical performance of Sn–Al film. The Sn–Al thin film with 18 wt% Al delivers high capacities of 822, 460 and 313 mA h g{sup −1} in the second 2nd, 60th and 200th cycles, respectively. Meanwhile, a discharge capacity of 420 mA h g{sup −1} is obtained at 3000 mA g{sup −1}. The excellent electrochemistry performance is owing to the core–shell structure in which Al shell can alleviate the expansion of volume of Sn particles and restrain the aggregation of Sn particles. The results indicate that Sn–Al thin film is a promising anode for lithium-ion batteries.

  18. Semi-transparent ordered TiO2 nanostructures prepared by anodization of titanium thin films deposited onto the FTO substrate

    Science.gov (United States)

    Szkoda, Mariusz; Lisowska-Oleksiak, Anna; Grochowska, Katarzyna; Skowroński, Łukasz; Karczewski, Jakub; Siuzdak, Katarzyna

    2016-09-01

    In a significant amount of cases, the highly ordered TiO2 nanotube arrays grow through anodic oxidation of a titanium metal plate immersed in electrolyte containing fluoride ions. However, for some practical applications, e.g. solar cells or electrochromic windows, the semi-transparent TiO2 formed directly on the transparent, conductive substrate is very much desired. This work shows that high-quality Ti coating could be formed at room temperature using an industrial magnetron sputtering system within 50 min. Under optimized conditions, the anodization process was performed on 2 μm titanium films deposited onto the FTO (fluorine-tin-oxide) support. Depending on the electrolyte type, highly ordered tubular or porous titania layers were obtained. The fabricated samples, after their thermal annealing, were investigated using scanning electron microscopy, Raman spectroscopy and UV-vis spectroscopy in order to investigate their morphology, crystallinity and absorbance ability. The photocurrent response curves indicate that materials are resistant to the photocorrosion process and their activity is strongly connected to optical properties. The most transparent TiO2 films were fabricated when Ti was anodized in water electrolyte, whereas the highest photocurrent densities (12 μA cm-2) were registered for titania received after Ti anodization in ethylene glycol solution. The obtained results are of significant importance in the production of thin, semi-transparent titania nanostructures on a commercial scale.

  19. An artificial photosynthesis anode electrode composed of a nanoparticulate photocatalyst film in a visible light responsive GaN-ZnO solid solution system

    Science.gov (United States)

    Imanaka, Yoshihiko; Anazawa, Toshihisa; Manabe, Toshio; Amada, Hideyuki; Ido, Sachio; Kumasaka, Fumiaki; Awaji, Naoki; Sánchez-Santolino, Gabriel; Ishikawa, Ryo; Ikuhara, Yuichi

    2016-01-01

    The artificial photosynthesis technology known as the Honda-Fujishima effect, which produces oxygen and hydrogen or organic energy from sunlight, water, and carbon dioxide, is an effective energy and environmental technology. The key component for the higher efficiency of this reaction system is the anode electrode, generally composed of a photocatalyst formed on a glass substrate from electrically conductive fluorine-doped tin oxide (FTO). To obtain a highly efficient electrode, a dense film composed of a nanoparticulate visible light responsive photocatalyst that usually has a complicated multi-element composition needs to be deposited and adhered onto the FTO. In this study, we discovered a method for controlling the electronic structure of a film by controlling the aerosol-type nanoparticle deposition (NPD) condition and thereby forming films of materials with a band gap smaller than that of the prepared raw material powder, and we succeeded in extracting a higher current from the anode electrode. As a result, we confirmed that a current approximately 100 times larger than those produced by conventional processes could be obtained using the same material. This effect can be expected not only from the materials discussed (GaN-ZnO) in this paper but also from any photocatalyst, particularly materials of solid solution compositions. PMID:27759108

  20. An artificial photosynthesis anode electrode composed of a nanoparticulate photocatalyst film in a visible light responsive GaN-ZnO solid solution system

    Science.gov (United States)

    Imanaka, Yoshihiko; Anazawa, Toshihisa; Manabe, Toshio; Amada, Hideyuki; Ido, Sachio; Kumasaka, Fumiaki; Awaji, Naoki; Sánchez-Santolino, Gabriel; Ishikawa, Ryo; Ikuhara, Yuichi

    2016-10-01

    The artificial photosynthesis technology known as the Honda-Fujishima effect, which produces oxygen and hydrogen or organic energy from sunlight, water, and carbon dioxide, is an effective energy and environmental technology. The key component for the higher efficiency of this reaction system is the anode electrode, generally composed of a photocatalyst formed on a glass substrate from electrically conductive fluorine-doped tin oxide (FTO). To obtain a highly efficient electrode, a dense film composed of a nanoparticulate visible light responsive photocatalyst that usually has a complicated multi-element composition needs to be deposited and adhered onto the FTO. In this study, we discovered a method for controlling the electronic structure of a film by controlling the aerosol-type nanoparticle deposition (NPD) condition and thereby forming films of materials with a band gap smaller than that of the prepared raw material powder, and we succeeded in extracting a higher current from the anode electrode. As a result, we confirmed that a current approximately 100 times larger than those produced by conventional processes could be obtained using the same material. This effect can be expected not only from the materials discussed (GaN-ZnO) in this paper but also from any photocatalyst, particularly materials of solid solution compositions.

  1. Porous anodic film formation on an Al-3.5 wt % Cu alloy

    Directory of Open Access Journals (Sweden)

    Páez, M. A.

    2003-12-01

    Full Text Available The morphological development of porous anodic films in the initial stages is examined during anodizing an Al-3.5 wt % Cu alloy in phosphoric acid. Using transmission electron microscopy a sequence of ultramicrotomed anodic sections reveals the dynamic evolution of numerous features in the thickening film in the initial stages of anodizing. The morphological changes in the anodic oxide in the initial stages of its formation appears related to the formation of bubbles during film growth. From Rutherford backscattering spectroscopy (RBS analysis of the film, the formation of the bubbles is associated with the enrichment of copper in the alloy due to growth of the anodic oxide. On the other hand, during constant current anodizing of Al-Cu in phosphoric acid, the current efficiency is considerably less than that for anodizing superpure aluminium under similar conditions. From the contrasting results between the charge consumed calculated from RBS and the real charge consumed during anodizing, oxygen gas bubbles generation and copper oxidation seem to be of less importance on the low efficiency for film formation. It is apparent that the main cause of losing efficiency for film growth on Al-Cu is associated with generation of oxygen at residual second phase, with the development of stresses in the film and, the consequence of these effects on film cracking during film growth.

    En este trabajo se examinó el desarrollo morfológico de películas anódicas porosas en los estados iniciales de la anodización de una aleación de aluminio Al-3,5 % p/p Cu. La observación de una secuencia de secciones ultramicrotomadas del metal y su película anódica, por microscopía electrónica de transmisión, revela la evolución dinámica de numerosos detalles morfológicos durante los inicios del crecimiento de la película anódica. Los cambios morfológicos en el óxido anódico, en los inicios de su formación, aparecen relacionados a la formación de

  2. Synthesis of bismuth (III oxide films based anodes for electrochemical degradation of reactive blue 19 and crystal violet

    Directory of Open Access Journals (Sweden)

    Petrović Milica M.

    2014-01-01

    Full Text Available The Bi2O3 films-based anodes were synthesized by electrodeposition of Bi on stainless steel substrate at constant current density and during different deposition times, fallowed by calcination, forming Bi2O3. The thickness of the films was determined by two methods: the observation under the microscope and by calculation from mass difference. Electrochemical proceses at the anodes were ivestigated by linear sweep voltammetry. At the anodes obtained within 2, 5, 10 and 15 minutes of deposition, two dyes, namely: Reactive Blue 19 and Crystal Violet, were decolorized by oxidation with •OH radical, generated from H2O2 decomposition at the anodes. Decoloration times of the anodes varied, and the shortest one was achieved with the anode obtained during 5 minutes of deposition, with the film thickness of 2.5±0.3 μm. The optimal H2O2 concentration for the dyes degradation was found to be 10 mmol dm-3. [Projekat Ministarstva nauke Republike Srbije, br. ТR 34008

  3. Phosphorus-Based Alloy Materials for Advanced Potassium-Ion Battery Anode.

    Science.gov (United States)

    Zhang, Wenchao; Mao, Jianfeng; Li, Sean; Chen, Zhixin; Guo, Zaiping

    2017-03-08

    Potassium-ion batteries (PIBs) are interesting as one of the alternative metal-ion battery systems to lithium-ion batteries (LIBs) due to the abundance and low cost of potassium. We have herein investigated Sn4P3/C composite as a novel anode material for PIBs. The electrode delivered a reversible capacity of 384.8 mA h g(-1) at 50 mA g(-1) and a good rate capability of 221.9 mA h g(-1), even at 1 A g(-1). Its electrochemical performance is better than any anode material reported so far for PIBs. It was also found that the Sn4P3/C electrode displays a discharge potential plateau of 0.1 V in PIBs, slightly higher than for sodium-ion batteries (SIBs) (0.01 V), and well above the plating potential of metal. This diminishes the formation of dendrites during cycling, and thus Sn4P3 is a relatively safe anode material, especially for application in large-scale energy storage, where large amounts of electrode materials are used. Furthermore, a possible reaction mechanism of the Sn4P3/C composite as PIB anode is proposed. This work may open up a new avenue for further development of alloy-based anodes with high capacity and long cycle life for PIBs.

  4. Anodization of Ti-based materials for biomedical applications: A review

    Directory of Open Access Journals (Sweden)

    Dragana R. Barjaktarević

    2016-09-01

    Full Text Available Commercially pure titanium (cpTi and titanium alloys are the most commonly used metallic biomaterials. Biomedical requirements for the successful usage of metallic implant materials include their high mechanical strength, low elastic modulus, excellent biocompatibility and high corrosion resistance. It is evident that the response of a biomaterial implanted into the human body depends entirely on its biocompatibility and surface properties. Therefore, in order to improve the performance of biomaterials in biological systems modification of their surface is necessary. One of most commonly used method of implant materials surface modification is electrochemical anodization and this method is reviewed in the present work.Aim of the presented review article is to explain the electrochemical anodization process and the way in which the nanotubes are formed by anodization on the metallic material surface. Influence of anodizing parameters on the nanotubes characteristics, such as nanotube diameter, length and nanotubular layer thickness, are described, as well as the anodized nanotubes influence on the material surface properties, corrosion resistance and biocompatibility.

  5. Semi-transparent ordered TiO{sub 2} nanostructures prepared by anodization of titanium thin films deposited onto the FTO substrate

    Energy Technology Data Exchange (ETDEWEB)

    Szkoda, Mariusz, E-mail: mariusz-szkoda@wp.pl [Department of Chemistry and Technology of Functional Materials, Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, Gdańsk 80-233 (Poland); Lisowska-Oleksiak, Anna [Department of Chemistry and Technology of Functional Materials, Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, Gdańsk 80-233 (Poland); Grochowska, Katarzyna [Centre for Plasma and Laser Engineering, Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Science, Fiszera 14, 80-231 Gdańsk (Poland); Skowroński, Łukasz [Institute of Mathematics and Physics, UTP University of Science and Technology, Kaliskiego 7, 85-796 Bydgoszcz (Poland); Karczewski, Jakub [Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk (Poland); Siuzdak, Katarzyna [Centre for Plasma and Laser Engineering, Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Science, Fiszera 14, 80-231 Gdańsk (Poland)

    2016-09-15

    Highlights: • High quality titanium coatings were doposited using industrial magnetron sputtering equipment. • Semi-transparent TiO{sub 2} were prepared via anodization realized in various conditions. • Depending on electrolyte type, ordered tubular or porous TiO{sub 2} layers were obtained. • Prepared material can act as semiconducting layer in photovoltaic cells. - Abstract: In a significant amount of cases, the highly ordered TiO{sub 2} nanotube arrays grow through anodic oxidation of a titanium metal plate immersed in electrolyte containing fluoride ions. However, for some practical applications, e.g. solar cells or electrochromic windows, the semi-transparent TiO{sub 2} formed directly on the transparent, conductive substrate is very much desired. This work shows that high-quality Ti coating could be formed at room temperature using an industrial magnetron sputtering system within 50 min. Under optimized conditions, the anodization process was performed on 2 μm titanium films deposited onto the FTO (fluorine-tin-oxide) support. Depending on the electrolyte type, highly ordered tubular or porous titania layers were obtained. The fabricated samples, after their thermal annealing, were investigated using scanning electron microscopy, Raman spectroscopy and UV–vis spectroscopy in order to investigate their morphology, crystallinity and absorbance ability. The photocurrent response curves indicate that materials are resistant to the photocorrosion process and their activity is strongly connected to optical properties. The most transparent TiO{sub 2} films were fabricated when Ti was anodized in water electrolyte, whereas the highest photocurrent densities (12 μA cm{sup −2}) were registered for titania received after Ti anodization in ethylene glycol solution. The obtained results are of significant importance in the production of thin, semi-transparent titania nanostructures on a commercial scale.

  6. MoOx thin films deposited by magnetron sputtering as an anode for aqueous micro-supercapacitors

    Directory of Open Access Journals (Sweden)

    Can Liu

    2013-11-01

    Full Text Available In order to examine the potential application of non-stoichiometric molybdenum oxide as anode materials for aqueous micro-supercapacitors, conductive MoOx films (2 ≤ x ≤ 2.3 deposited via RF magnetron sputtering at different temperatures were systematically studied for composition, structure and electrochemical properties in an aqueous solution of Li2SO4. The MoOx (x ≈ 2.3 film deposited at 150 °C exhibited a higher areal capacitance (31 mF cm−2 measured at 5 mV s−1, best rate capability and excellent stability at potentials below −0.1 V versus saturated calomel electrode, compared to the films deposited at room temperature and at higher temperatures. These superior properties were attributed to the multi-valence composition and mixed-phase microstructure, i.e., the coexistence of MoO2 nanocrystals and amorphous MoOx (2.3 < x ≤ 3. A mechanism combining Mo(IV oxidation/reduction on the hydrated MoO2 grain surfaces and cation intercalation/extrusion is proposed to illustrate the pseudo-capacitive process.

  7. 2D Frameworks of C2 N and C3 N as New Anode Materials for Lithium-Ion Batteries.

    Science.gov (United States)

    Xu, Jiantie; Mahmood, Javeed; Dou, Yuhai; Dou, Shixue; Li, Feng; Dai, Liming; Baek, Jong-Beom

    2017-09-01

    Novel layered 2D frameworks (C3 N and C2 N-450) with well-defined crystal structures are explored for use as anode materials in lithium-ion batteries (LIBs) for the first time. As anode materials for LIBs, C3 N and C2 N-450 exhibit unusual electrochemical characteristics. For example, C2 N-450 (and C3 N) display high reversible capacities of 933.2 (383.3) and 40.1 (179.5) mAh g(-1) at 0.1 and 10 C, respectively. Furthermore, C3 N shows a low hypothetical voltage (≈0.15 V), efficient operating voltage window with ≈85% of full discharge capacity secured at >0.45 V, and excellent cycling stability for more than 500 cycles. The excellent electrochemical performance (especially of C3 N) can be attributed to their inherent 2D polyaniline frameworks, which provide large net positive charge densities, excellent structural stability, and enhanced electronic/ionic conductivity. Stable solid state interface films also form on the surfaces of the 2D materials during the charge/discharge process. These 2D materials with promising electrochemical performance should provide insights to guide the design and development of their analogues for future energy applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Anodized Nanoporous Titania Thin Films for Dental Application: Structure’ Effect on Corrosion Behavior

    Directory of Open Access Journals (Sweden)

    A. Boucheham

    2016-06-01

    Full Text Available Nanostructured Titania layers formed on the surface of titanium and titanium alloys by anodic oxidation play an important role in the enhancement of their biocompatibility and osseointegration in the human body. For this purpose, we aimed to study in the current work the structural and electrochemical properties of amorphous and crystallized nanostructured TiO2 thin films elaborated on Ti6Al4V substrate by electrochemical anodization in fluoride ions (F– containing electrolyte at 10 V during 15 min and heat treated in air at 550 °C for 2 h. The morphology, chemical composition and phase composition of synthesized layers were investigated using field emission scanning electron microscopy (FE-SEM and X-ray diffraction (XRD. The corrosion resistance improvement of both as-anodized and annealed titania layers was evaluated in 0.9 wt. % NaCl solution with pH = 6.4 at room temperature by means of open circuit potential (Eoc,potentiodynamic polarization (PDYN and electrochemical impedance spectroscopy (EIS.

  9. Alternative anode materials for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Goodenough, John B.; Huang, Yun-Hui [Texas Materials Institute, ETC 9.102, 1 University Station, C2200, The University of Texas at Austin, Austin, TX 78712 (United States)

    2007-11-08

    The electrolyte of a solid oxide fuel cell (SOFC) is an O{sup 2-}-ion conductor. The anode must oxidize the fuel with O{sup 2-} ions received from the electrolyte and it must deliver electrons of the fuel chemisorption reaction to a current collector. Cells operating on H{sub 2} and CO generally use a porous Ni/electrolyte cermet that supports a thin, dense electrolyte. Ni acts as both the electronic conductor and the catalyst for splitting the H{sub 2} bond; the oxidation of H{sub 2} to H{sub 2}O occurs at the Ni/electrolyte/H{sub 2} triple-phase boundary (TPB). The CO is oxidized at the oxide component of the cermet, which may be the electrolyte, yttria-stabilized zirconia, or a mixed oxide-ion/electron conductor (MIEC). The MIEC is commonly a Gd-doped ceria. The design and fabrication of these anodes are evaluated. Use of natural gas as the fuel requires another strategy, and MIECs are being explored for this application. The several constraints on these MIECs are outlined, and preliminary results of this on-going investigation are reviewed. (author)

  10. The Effect of Silane on the Microstructure, Corrosion, and Abrasion Resistances of the Anodic Films on Ti Alloy

    Science.gov (United States)

    Wang, Jinwei; Chen, Jiali

    2016-04-01

    Anodic oxide films on Ti-6Al-4V alloy are prepared using sodium hydroxide as the base electrolyte containing aminopropyl trimethoxysilane (APS) as an additive. Some APS undergo hydrolysis, adsorption, and chemical reaction with the TiO x to form Ti-O-Si bond as confirmed by ATR-FTIR and XPS spectra, and in turn their surface appearance and roughness are greatly changed with the addition of APS as observed by their SEM images. These amino anodic films possess much higher corrosive resistances since the formation of Ti-O-Si complex enhances the compactness of the anodic films and the existence of aminopropyl groups inside the pores provides additional blocking effects. Besides, their improvement in anti-abrasive capability is attributed to the toughening effect of the chemically bonded silanes and the lubrication functions from both the chemically bonded and physically absorbed silanes between the touched interfaces.

  11. Decisive influence of colloidal suspension conductivity during electrophoretic impregnation of porous anodic film supported on 1050 aluminium substrate.

    Science.gov (United States)

    Fori, B; Taberna, P L; Arurault, L; Bonino, J P

    2014-01-01

    The present paper studies the influence of suspension conductivity on the electrophoretic deposition (EPD) of nanoparticles inside a porous anodic aluminium oxide film. It is shown that an increase in the suspension's conductivity enhances impregnation of the anodic film by the nanoparticles. Two mechanisms are seen to promote the migration of particles into the pores. Indeed an increase in the suspension conductivity leads on the one hand to a strengthening of the electric field in the anodic film and on the other hand to a thinning of the electric double layer on the pore walls. The results of our study confirm that colloidal suspension conductivity is a key parameter governing the electrophoretic impregnation depth.

  12. On hydrophilicity improvement of the porous anodic alumina film by hybrid nano/micro structuring

    Science.gov (United States)

    Wang, Weichao; Zhao, Wei; Wang, Kaige; Wang, Lei; Wang, Xuewen; Wang, Shuang; Zhang, Chen; Bai, Jintao

    2017-09-01

    In both, laboratory and industry, tremendous attention is paid to discover an effective technique to produce uniform, controllable and (super) hydrophilic surfaces over large areas that are useful in a wide range of applications. In this investigation, by combing porous anodic alumina (PAA) film with nano-structures and microarray of aluminum, the hydrophilicity of hybrid nano-micro structure has been significantly improved. It is found some factors can affect the hydrophilicity of film, such as the size and aspect ratio of microarray, the thickness of nano-PAA film etc. Comparing with pure nano-PAA films and microarray, the hybrid nano-micro structure can provide uniform surface with significantly better hydrophilicity. The improvement can be up to 84%. Also, this technique exhibits good stability and repeatability for industrial production. By optimizing the thickness of nano-PAA film and aspect ratio of micro-structures, super-hydrophilicity can be reached. This study has obvious prospect in the fields of chemical industry, biomedical engineering and lab-on-a-chip applications.

  13. Electrodeposition of photocatalytic TiO2 film on surface of alumina prepared by anodic oxidation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-yu; CHEN Tie-qun

    2004-01-01

    A new electrochemical method to prepare photocatalytic TiO2 thin film was developed, by which the TiO2 was electrodeposited on surface of alumina by AC electrolysis in solution consisting of K2 [TiO(C2O4 )2] and C2H2O4. The deposited TiO2 thin film was primarily characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM) and energy dispersive spectrum (EDS) methods. The photocatalytic properties of this film were also studied by the photocatalytic degradation of methyl orange. The results show that the TiO2 film electrodeposited by this method is mainly in amorphous and with a little crystalline component mixed anatase and rutile. The surface of the alumina prepared by anodic oxidation is porous and the TiO2 electrodeposited on it is scattered and incompact. TiO2 thin film fixed on the surface of alumina shows photocatalytic activity to the degradation of methyl orange.

  14. Effects of benzotriazole on anodized film formed on AZ31B magnesium alloy in environmental-friendly electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Guo Xinghua [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin (China); An Maozhong, E-mail: mzan@hit.edu.c [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin (China); Yang Peixia; Li Haixian; Su Caina [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin (China)

    2009-08-12

    An environmental-friendly electrolyte of silicate and borate, which contained an addition agent of 1H-benzotriazole (BTA) with low toxicity (LD50 of 965 mg/kg), was used to prepare an anodized film on AZ31B magnesium alloy under the constant current density of 1.5 A/dm{sup 2} at room temperature. Effects of BTA on the properties of the anodized film were studied by scanning electron microscopy (SEM), energy dispersion spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), loss weight measurement, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), respectively. The results demonstrated that anodized growth process, surface morphology, thickness, phase structure and corrosion resistance of the anodized film were strongly dependant on the BTA concentration, which might be attributed to the formation of an BTA adsorption layer on magnesium substrate surface. When the BTA concentration was 5 g/L in the electrolyte, a compact and thick anodized film could provide excellent corrosion resistance for AZ31B magnesium alloy.

  15. Formation and disruption of current paths of anodic porous alumina films by conducting atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Oyoshi, K., E-mail: oyoshi.keiji@nims.go.jp [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Nigo, S.; Inoue, J.; Sakai, O.; Kitazawa, H.; Kido, G. [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan)

    2010-11-15

    Anodic porous alumina (APA) films have a honeycomb cell structure of pores and a voltage-induced bi-stable switching effect. We have applied conducting atomic force microscopy (CAFM) as a method to form and to disrupt current paths in the APA films. A bi-polar switching operation was confirmed. We have firstly observed terminals of current paths as spots or areas typically on the center of the triangle formed by three pores. In addition, though a part of the current path showed repetitive switching, most of them were not observed again at the same position after one cycle of switching operations in the present experiments. This suggests that a part of alumina structure and/or composition along the current paths is modified during the switching operations.

  16. A mediatorless microbial fuel cell using polypyrrole coated carbon nanotubes composite as anode material

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Yongjin; Xiang, Cuili; Yang, Lini [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Sun, Li-Xian [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); School of Chemistry and Environmental Engineering, Changsha University of Science and Technology, Changsha 410076 (China); Xu, Fen [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Cao, Zhong [School of Chemistry and Environmental Engineering, Changsha University of Science and Technology, Changsha 410076 (China)

    2008-09-15

    A microbial fuel cell (MFC) was constructed using polypyrrole (PPy) coated carbon nanotubes (CNTs) composite as an anode material and Escherichia coli as the biocatalyst. The composite PPy-CNTs were synthesized by the in situ chemical polymerization of pyrrole on the CNTs using ammonium persulfate as an oxidant. The electrocatalytic behaviors of the composite modified anode were investigated by means of cyclic voltammetry, electrochemical impedance spectroscopy and discharge experiments. The PPy-CNTs modified anode showed better electrochemical performance than that of plain carbon paper. The amount of the loading of the composite on the anode was also investigated. The power output of the MFC increased along with the increase of the composite loading. In the absence of exogenous electron mediators, the MFC with the composite modified anode contained 5 mg cm{sup -2} PPy-CNTs exhibited a maximum power density 228 mW m{sup -2}, which is much higher than those reported in the literature so far for E. coli using efficient electron mediators. These results show that the PPy-CNTs composite anode is promising for MFC application. (author)

  17. A new anode material for oxygen evolution in molten oxide electrolysis.

    Science.gov (United States)

    Allanore, Antoine; Yin, Lan; Sadoway, Donald R

    2013-05-16

    Molten oxide electrolysis (MOE) is an electrometallurgical technique that enables the direct production of metal in the liquid state from oxide feedstock, and compared with traditional methods of extractive metallurgy offers both a substantial simplification of the process and a significant reduction in energy consumption. MOE is also considered a promising route for mitigation of CO2 emissions in steelmaking, production of metals free of carbon, and generation of oxygen for extra-terrestrial exploration. Until now, MOE has been demonstrated using anode materials that are consumable (graphite for use with ferro-alloys and titanium) or unaffordable for terrestrial applications (iridium for use with iron). To enable metal production without process carbon, MOE requires an anode material that resists depletion while sustaining oxygen evolution. The challenges for iron production are threefold. First, the process temperature is in excess of 1,538 degrees Celsius (ref. 10). Second, under anodic polarization most metals inevitably corrode in such conditions. Third, iron oxide undergoes spontaneous reduction on contact with most refractory metals and even carbon. Here we show that anodes comprising chromium-based alloys exhibit limited consumption during iron extraction and oxygen evolution by MOE. The anode stability is due to the formation of an electronically conductive solid solution of chromium(iii) and aluminium oxides in the corundum structure. These findings make practicable larger-scale evaluation of MOE for the production of steel, and potentially provide a key material component enabling mitigation of greenhouse-gas emissions while producing metal of superior metallurgical quality.

  18. Amorphous boron nanorod as an anode material for lithium-ion batteries at room temperature.

    Science.gov (United States)

    Deng, Changjian; Lau, Miu Lun; Barkholtz, Heather M; Xu, Haiping; Parrish, Riley; Xu, Meiyue Olivia; Xu, Tao; Liu, Yuzi; Wang, Hao; Connell, Justin G; Smith, Kassiopeia A; Xiong, Hui

    2017-08-03

    We report an amorphous boron nanorod anode material for lithium-ion batteries prepared through smelting non-toxic boron oxide in liquid lithium. Boron in theory can provide capacity as high as 3099 mA h g(-1) by alloying with Li to form B4Li5. However, experimental studies of the boron anode have been rarely reported for room temperature lithium-ion batteries. Among the reported studies the electrochemical activity and cycling performance of the bulk crystalline boron anode material are poor at room temperature. In this work, we utilized an amorphous nanostructured one-dimensional (1D) boron material aiming at improving the electrochemical reactivity between boron and lithium ions at room temperature. The amorphous boron nanorod anode exhibited, at room temperature, a reversible capacity of 170 mA h g(-1) at a current rate of 10 mA g(-1) between 0.01 and 2 V. The anode also demonstrated good rate capability and cycling stability. The lithium storage mechanism was investigated by both sweep voltammetry measurements and galvanostatic intermittent titration techniques (GITTs). The sweep voltammetric analysis suggested that the contributions from lithium ion diffusion into boron and the capacitive process to the overall lithium charge storage are 57% and 43%, respectively. The results from GITT indicated that the discharge capacity at higher potentials (>∼0.2 V vs. Li/Li(+)) could be ascribed to a capacitive process and at lower potentials (lithium-ion batteries.

  19. Nano-sized carboxylates as anode materials for rechargeable lithium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan Wu; Jie Ma; Yong-Sheng Hu; Hong Li; Liquan Chen

    2014-01-01

    Nano-sized carboxylates Na2C7H3NO4 and Na2C6H2N2O4 were prepared and investigated as anode materials for lithium-ion batteries. Both carboxylates exhibit high reversible capacities around 190 mAh/g above a cut-off voltage of 0.8 V vs. Li+/Li, potentially improving the safety of the batteries. In addition, good rate performance and long cycle life of these carboxylates make them promising candidates as anode materials for lithium-ion batteries.

  20. Hybrid Direct Carbon Fuel Cell Performance with Anode Current Collector Material

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Kammer Hansen, Kent

    2015-01-01

    The influence of the current collector on the performance of a hybrid direct carbon fuel cell (HDCFC), consisting of solid oxide fuel cell (SOFC) with a molten carbonate-carbon slurry in contact with the anode, has been investigated using current-voltage curves. Four different anode current...... collectors were studied: Au, Ni, Ag, and Pt. It was shown that the performance of the direct carbon fuel cell (DCFC) is dependent on the current collector materials, Ni and Pt giving the best performance, due to their catalytic activity. Gold is suggested to be the best material as an inert current collector...

  1. Silicon Composite Anode Materials for Lithium Ion Batteries Based on Carbon Cryogels and Carbon Paper

    Science.gov (United States)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nanofoams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  2. Carbon Cryogel and Carbon Paper-Based Silicon Composite Anode Materials for Lithium-Ion Batteries

    Science.gov (United States)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 6 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-5 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  3. Preparation of mesoporous alumina films by anodization: Effect of pretreatments on the aluminum surface and MTBE catalytic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, A.L., E-mail: avazquezd@ipn.m [Departamento de Ingenieria Metalurgica, ESIQIE-IPN, AP 75-876, Mexico, D.F. (Mexico); Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Lazaro Cardenas 152, C.P. 07730, Mexico, D.F. (Mexico); Carrera, R. [Departamento de Ingenieria Metalurgica, ESIQIE-IPN, AP 75-876, Mexico, D.F. (Mexico); Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Lazaro Cardenas 152, C.P. 07730, Mexico, D.F. (Mexico); Arce, E. [Departamento de Ingenieria Metalurgica, ESIQIE-IPN, AP 75-876, Mexico, D.F. (Mexico); Castillo, N. [CINVESTAV, Departamento de Fisica. Av. IPN 2508, 07360, Mexico, D.F (Mexico); Castillo, S. [Departamento de Ingenieria Metalurgica, ESIQIE-IPN, AP 75-876, Mexico, D.F. (Mexico); Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Lazaro Cardenas 152, C.P. 07730, Mexico, D.F. (Mexico); Moran-Pineda, M. [Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Lazaro Cardenas 152, C.P. 07730, Mexico, D.F. (Mexico)

    2009-08-26

    Mesoporous materials are both scientifically and technologically important because of the presence of voids of controllable dimensions at atomic, molecular, and nanometric scales. Over the last decade, there has been both an increasing interest and research effort in the synthesis and characterization of these types of materials. The purposes of this work are to study the physical and chemical changes in the properties of mesoporous alumina films produced by anodization in sulphuric acid by different pretreatments on the aluminium surface such as mechanical polishing [MP] and electropolishing [EP]; and to compare their properties such as morphology, structure and catalytic activity with those present in commercial alumina. The morphologic and physical characterizations of the alumina film samples were carried out by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The chemical evaluations were performed by the oxidation of methyl-tert-butyl-ether (MTBE) at 400 deg. C under O{sub 2}/He oxidizing conditions (Praxair, 2.0% O{sub 2}/He balance). According to the results, the samples that presented higher activities than those in Al{sub 2}O{sub 3}/Al [MP] and commercial alumina in the MTBE oxidation (69%), were those prepared by Al{sub 2}O{sub 3}/Al [EP]. The average mesoporous diameter was 17 nm, and the morphological shape was equiaxial; thus, that pore distribution was the smallest of all with a homogeneous distribution.

  4. Studies of AN Extractor Geometry Magnetically Insulated Ion Diode with AN Exploding Metal Film Anode Plasma Source.

    Science.gov (United States)

    Rondeau, Gary D.

    Magnetically insulated diodes (MIDs) are of interest as ion sources for inertial confinement fusion. We examine several issues that are of concern with MIDs, including ion turn-on delay and anode plasma production, and diode impedance history and particle current scaling with the applied magnetic field and gap spacing. The LION pulsed power generator (1.5 MV, 4 Omega, 40 ns pulse length) was used to power an extractor geometry magnetically insulated (radial magnetic field) ion beam diode. The diode was studied with three anode configurations. In the first, with epoxy-filled-groove (epoxy) anodes, scaling of the ion and electron currents with the gap and the magnetic field was examined. We found that the observed ion current is consistent with a diode model that has been successful with barrel geometry MIDs. The electron leakage current scaled proportionally to 1/Bd^2, where d is the anode-cathode gap spacing and B is the magnetic field strength. Studies of ion beam propagation in vacuum showed that space charge non -neutrality near the magnetic field coils caused the beam to expand initially. Later in the ion pulse (20 to 30 ns), the beam expansion became much less severe. The second anode configuration utilized an "electron collector" protruding above an epoxy anode surface. With the collector, we observed less bremsstrahlung across the active anode region. From the damage to thin wires inserted into the anode and from the level of the ion current, we inferred that the electron layer was 1-2 mm further from the anode on collector shots. The last anode configuration studied was the exploding metal film active anode plasma source (EMFAAPS). Current from the accelerator was directed by an electron collector or a plasma opening switch through a thin aluminum film, which exploded to form the anode plasma. The primary ion species from EMFAAPS were protons, Al^{3+ } and Al^{2+}, although oxygen discharge cleaning reduced the proton fraction in favor of O^{3+}, O ^{2+}, C

  5. Superstructured Carbon Nanotube/Porous Silicon Hybrid Materials for Lithium-Ion Battery Anodes

    Science.gov (United States)

    Lee, Jun-Ki; Kang, Shin-Hyun; Choi, Sung-Min

    2015-03-01

    High energy Li-ion batteries (LIBs) are in great demand for electronics, electric-vehicles, and grid-scale energy storage. To further increase the energy and power densities of LIBs, Si anodes have been intensively explored due to their high capacity, and high abundance compared with traditional carbon anodes. However, the poor cycle-life caused by large volume expansion during charge/discharge process has been an impediment to its applications. Recently, superstructured Si materials were received attentions to solve above mentioned problem in excellent mechanical properties, large surface area, and fast Li and electron transportation aspects, but applying superstructures to anode is in early stage yet. Here, we synthesized superstructured carbon nanotubes (CNTs)/porous Si hybrid materials and its particular electrochemical properties will be presented. Department of Nuclear and Quantum Engineering

  6. Sorption of hydrophilic dyes on anodic aluminium oxide films and application to pH sensing.

    Science.gov (United States)

    Silina, Yuliya E; Kuchmenko, Tatyana A; Volmer, Dietrich A

    2015-02-07

    The sorption of selected hydrophilic pH-sensitive dyes (bromophenol blue, bromothymol blue, bromocresol purple, alizarin red, methyl orange, congo red, rhodamine 6G) on films of anodized aluminium oxide (AAO) was investigated in this study. Depth and pore structure of the AAO channels were adjusted by changing electrolysis time and current density during treatment of aluminium foil in oxalic acid, sulfosalycilic acid and sulfuric acid at concentration levels between 0.2 and 0.6 M. The dyes were immobilized on the AAO surface by direct saturation of the films in dye solutions. It was shown by scanning electron microscopy and X-ray spectral analysis that the dyes penetrated into the AAO channels by more than 1.5 μm, even at static saturation conditions. The anionic dyes linked to the porous AAO surface exhibited differential shifts of the UV absorption bands in their acidic/basic forms. By combining several dyes, the films have an application range between pH = 0.5-9 in aqueous media. The dye-modified AAO film was a simple, portable, inexpensive and reusable pH sensor with very fast response time and clear colour transitions.

  7. Synthesis, Characterization and Testing of Novel Anode and Cathode Materials for Li-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    White, Ralph E.; Popov, Branko N.

    2002-10-31

    During this program we have synthesized and characterized several novel cathode and anode materials for application in Li-ion batteries. Novel synthesis routes like chemical doping, electroless deposition and sol-gel method have been used and techniques like impedance, cyclic voltammetry and charge-discharge cycling have been used to characterize these materials. Mathematical models have also been developed to fit the experimental result, thus helping in understanding the mechanisms of these materials.

  8. Influence of voltage waveform on anodic film of AZ91 Mg alloy via plasma electrolytic oxidation: Microstructural characteristics and electrochemical responses

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Young Gun [School of Materials Science and Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Lee, Eung Seok [Department of Metallurgy and Materials Engineering, Hanyang University, Ansan 426-791 (Korea, Republic of); Shin, Dong Hyuk, E-mail: dhshin@hanyang.ac.kr [Department of Metallurgy and Materials Engineering, Hanyang University, Ansan 426-791 (Korea, Republic of)

    2014-02-15

    Highlights: • The effect of voltage waveform on the anodic film structure is significant. • The anodic film by asymmetric-sine wave is denser than that by half-sine wave. • Asymmetric-sine wave results in excellent electrochemical properties. -- Abstract: The present study investigated how the voltage waveform influenced the microstructural characteristics and electrochemical responses of the anodic film on AZ91 Mg alloy coated by plasma electrolytic oxidation (PEO). PEO coatings of AZ91 Mg alloy were performed for 600 s in an alkaline silicate electrolyte with respect to the voltage waveform such as half-sine and asymmetric-sine waveforms. Microstructural observations on cross section of the anodic film utilizing scanning electron microscope revealed that the anodic film formed via asymmetric-sine wave was much denser in structure than that via half-sine counterpart since the occurrence of the cathodic breakdown between the anodic pulses could effectively suppress the formation of the micro-pores and discharge channels in the anodic films. Thereby, the hardness and corrosion properties of the anodic film formed by asymmetric-sine wave were found to be superior to those by half-sine wave. In addition, electrochemical responses were interpreted in relation to the equivalent circuit model consisting of resistor and capacitor elements within an electrical cell.

  9. Electrochemical Characteristics of Tin Oxide-Graphite as Anode Material for Lithium-ion Cells

    Science.gov (United States)

    Hasanaly, Siti Munirah

    2010-03-01

    Tin oxide anode materials used in lithium-ion cells experience large volume changes during charging and discharging which cause substantial losses in capacity. In this work, the tin oxide-graphite composite is proposed as an alternative anode material to overcome this problem. The composite was synthesised from a solution of tin chloride dihydrate and graphite powders with citric acid as the chelating agent. In this sol-gel method, a solid phase is formed through a chemical reaction in a liquid phase at moderate temperature. The technique offers several advantages compared to the solid state synthesis technique such as the ability to maintain the homogeneous mixture of precursors during synthesis and to produce small particles. The electrochemical behaviour of the anode material was investigated by means of galvanostatic charge discharge technique. An initial reversible capacity of 748 mAh/g is obtained and nearly 600 mAh/g was retained upon the reaching the fifth cycle. This study shows that the presence of graphite is able to minimise the agglomeration of tin particles that causes large volume changes during cycling, thereby improving cyclability of the anode material.

  10. Submicron organic nanofiber devices with different anode-cathode materials: A simple approach

    DEFF Research Database (Denmark)

    Henrichsen, Henrik Hartmann; Sturm, Heinz; Bøggild, Peter

    2010-01-01

    The authors present a simple general method for simultaneously producing tens of submicron electrode gaps with different cathode and anode materials on top of nanofibers, nanowires, and nanotubes, with an optional gap size variation. Using this method, an ensemble of para-hexaphenylene (p6P...

  11. Bacterial nanometric amorphous Fe-based oxide: a potential lithium-ion battery anode material.

    Science.gov (United States)

    Hashimoto, Hideki; Kobayashi, Genki; Sakuma, Ryo; Fujii, Tatsuo; Hayashi, Naoaki; Suzuki, Tomoko; Kanno, Ryoji; Takano, Mikio; Takada, Jun

    2014-04-23

    Amorphous Fe(3+)-based oxide nanoparticles produced by Leptothrix ochracea, aquatic bacteria living worldwide, show a potential as an Fe(3+)/Fe(0) conversion anode material for lithium-ion batteries. The presence of minor components, Si and P, in the original nanoparticles leads to a specific electrode architecture with Fe-based electrochemical centers embedded in a Si, P-based amorphous matrix.

  12. Nb-doped rutile TiO₂: a potential anode material for Na-ion battery.

    Science.gov (United States)

    Usui, Hiroyuki; Yoshioka, Sho; Wasada, Kuniaki; Shimizu, Masahiro; Sakaguchi, Hiroki

    2015-04-01

    The electrochemical properties of the rutile-type TiO2 and Nb-doped TiO2 were investigated for the first time as Na-ion battery anodes. Ti(1-x)Nb(x)O2 thick-film electrodes without a binder and a conductive additive were prepared using a sol-gel method followed by a gas-deposition method. The TiO2 electrode showed reversible reactions of Na insertion/extraction accompanied by expansion/contraction of the TiO2 lattice. Among the Ti(1-x)Nb(x)O2 electrodes with x = 0-0.18, the Ti(0.94)Nb(0.06)O2 electrode exhibited the best cycling performance, with a reversible capacity of 160 mA h g(-1) at the 50th cycle. As the Li-ion battery anode, this electrode also attained an excellent rate capability, with a capacity of 120 mA h g(-1) even at the high current density of 16.75 A g(-1) (50C). The improvements in the performances are attributed to a 3 orders of magnitude higher electronic conductivity of Ti(0.94)Nb(0.06)O2 compared to that of TiO2. This offers the possibility of Nb-doped rutile TiO2 as a Na-ion battery anode as well as a Li-ion battery anode.

  13. Preparation of TiO2 nanotube on glass by anodization of Ti films at room temperature

    Institute of Scientific and Technical Information of China (English)

    TANG Yu-xin; TAO Jie; ZHANG Yan-yan; WU Tao; TAO Hai-jun; ZHU Ya-rong

    2009-01-01

    In order to fabricate titania nanotubes on glass substrate, Ti thin films (700-900 nm) were first deposited by radio-frequency(RF) magnetron sputtering and then anodized in an aqueous HF electrolyte solution at room temperature. The morphology and structure of the nanotubes were identified by means of field emission scanning electron microscopy(FE-SEM) and X-ray diffractometry(XRD). The effects of anodization parameters (concentration of electrolyte, applied voltage) on nanotube morphology were comprehensively investigated. The results show that the dense and crystalline Ti film can be obtained on the unheated glass substrate under the sputtering power of 150 W, and the anodization current and voltage play significant roles in the formation of titania nanotube with different tube sizes.

  14. Growth characterization of anodic film on AZ91D magnesium alloy in an electrolyte of Na2SiO3 and KF

    Institute of Scientific and Technical Information of China (English)

    Weiping Li; Liqun Zhu; Yihong Li; Bo Zhao

    2006-01-01

    Anodization of AZ91D magnesium alloy in the electrolyte solution of 0.5 mol/L of sodium silicate and 1.0 mol/L of potassium fluoride was investigated. The anodic films were characterized using optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The corrosion resistance of the various anodized alloys was evaluated by a fast corrosion test using the solution of hydrochloric acid and potassium dichromate. The results showed that the addition of KF resulted in the presence of NaF in the anodic film. The thickness of the anodic film formed under a constant current density of 20 mA/cm2 for 16 min at 60℃ exceeded 100 μm. The growth of the anodic film could be divided into three stages based on the anodizing time; the growth rate was much faster during stage Ⅱ than in stages Ⅰ and Ⅲ. The anodic film exhibited the highest corrosion resistance for the AZ91 alloy,which is attributed to the fact that the anodization was maintained until the end of stage Ⅱ.

  15. Carbon-Coated SnO2 Nanorod Array for Lithium-Ion Battery Anode Material

    Directory of Open Access Journals (Sweden)

    Ji Xiaoxu

    2010-01-01

    Full Text Available Abstract Carbon-coated SnO2 nanorod array directly grown on the substrate has been prepared by a two-step hydrothermal method for anode material of lithium-ion batteries (LIBs. The structural, morphological and electrochemical properties were investigated by means of X-ray diffraction (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM and electrochemical measurement. When used as anodes for LIBs with high current density, as-obtained array reveals excellent cycling stability and rate capability. This straightforward approach can be extended to the synthesis of other carbon-coated metal oxides for application of LIBs.

  16. TiO2 nanotube formation by Ti film anodization and their transport properties for dye-sensitized solar cells

    NARCIS (Netherlands)

    Iraj, M.; Kolahdouz, M.; Asl-Soleimani, E.; Esmaeili, E.; Kolahdouz Esfahani, Z.

    2016-01-01

    In this paper, we present the synthesis of TiO2 nanotube (NT) arrays formed by anodization of Ti film deposited on a fluorine-doped tin oxide-coated glass substrate by direct current magnetron sputtering. NH4F/ethylene glycol electrolyte was used to demonstrate the growth of stable nanotubes at room

  17. Evaluation of anode (electro)catalytic materials for the direct borohydride fuel cell: Methods and benchmarks

    Science.gov (United States)

    Olu, Pierre-Yves; Job, Nathalie; Chatenet, Marian

    2016-09-01

    In this paper, different methods are discussed for the evaluation of the potential of a given catalyst, in view of an application as a direct borohydride fuel cell DBFC anode material. Characterizations results in DBFC configuration are notably analyzed at the light of important experimental variables which influence the performances of the DBFC. However, in many practical DBFC-oriented studies, these various experimental variables prevent one to isolate the influence of the anode catalyst on the cell performances. Thus, the electrochemical three-electrode cell is a widely-employed and useful tool to isolate the DBFC anode catalyst and to investigate its electrocatalytic activity towards the borohydride oxidation reaction (BOR) in the absence of other limitations. This article reviews selected results for different types of catalysts in electrochemical cell containing a sodium borohydride alkaline electrolyte. In particular, propositions of common experimental conditions and benchmarks are given for practical evaluation of the electrocatalytic activity towards the BOR in three-electrode cell configuration. The major issue of gaseous hydrogen generation and escape upon DBFC operation is also addressed through a comprehensive review of various results depending on the anode composition. At last, preliminary concerns are raised about the stability of potential anode catalysts upon DBFC operation.

  18. Nanoscale Engineering of Heterostructured Anode Materials for Boosting Lithium-Ion Storage.

    Science.gov (United States)

    Chen, Gen; Yan, Litao; Luo, Hongmei; Guo, Shaojun

    2016-09-01

    Rechargeable lithium-ion batteries (LIBs), as one of the most important electrochemical energy-storage devices, currently provide the dominant power source for a range of devices, including portable electronic devices and electric vehicles, due to their high energy and power densities. The interest in exploring new electrode materials for LIBs has been drastically increasing due to the surging demands for clean energy. However, the challenging issues essential to the development of electrode materials are their low lithium capacity, poor rate ability, and low cycling stability, which strongly limit their practical applications. Recent remarkable advances in material science and nanotechnology enable rational design of heterostructured nanomaterials with optimized composition and fine nanostructure, providing new opportunities for enhancing electrochemical performance. Here, the progress as to how to design new types of heterostructured anode materials for enhancing LIBs is reviewed, in the terms of capacity, rate ability, and cycling stability: i) carbon-nanomaterials-supported heterostructured anode materials; ii) conducting-polymer-coated electrode materials; iii) inorganic transition-metal compounds with core@shell structures; and iv) combined strategies to novel heterostructures. By applying different strategies, nanoscale heterostructured anode materials with reduced size, large surfaces area, enhanced electronic conductivity, structural stability, and fast electron and ion transport, are explored for boosting LIBs in terms of high capacity, long cycling lifespan, and high rate durability. Finally, the challenges and perspectives of future materials design for high-performance LIB anodes are considered. The strategies discussed here not only provide promising electrode materials for energy storage, but also offer opportunities in being extended for making a variety of novel heterostructured nanomaterials for practical renewable energy applications.

  19. Electromagnetic characteristics of carbon nanotube film materials

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2015-08-01

    Full Text Available Carbon nanotube (CNT possesses remarkable electrical conductivity, which shows great potential for the application as electromagnetic shielding material. This paper aims to characterize the electromagnetic parameters of a high CNT loading film by using waveguide method. The effects of layer number of CNT laminate, CNT alignment and resin impregnation on the electromagnetic characteristics were analyzed. It is shown that CNT film exhibits anisotropic electromagnetic characteristic. Pristine CNT film shows higher real part of complex permittivity, conductivity and shielding effectiveness when the polarized direction of incident wave is perpendicular to the winding direction of CNT film. For the CNT film laminates, complex permittivity increases with increasing layer number, and correspondingly, shielding effectiveness decreases. The five-layer CNT film shows extraordinary shielding performance with shielding effectiveness ranging from 67 dB to 78 dB in X-band. Stretching process induces the alignment of CNTs. When aligned direction of CNTs is parallel to the electric field, CNT film shows negative permittivity and higher conductivity. Moreover, resin impregnation into CNT film leads to the decrease of conductivity and shielding effectiveness. This research will contribute to the structural design for the application of CNT film as electromagnetic shielding materials.

  20. Anodic deposition of colloidal iridium oxide thin films from hexahydroxyiridate(IV) solutions.

    Science.gov (United States)

    Zhao, Yixin; Vargas-Barbosa, Nella M; Hernandez-Pagan, Emil A; Mallouk, Thomas E

    2011-07-18

    A facile, in-situ deposition route to stable iridium oxide (IrO(x)·nH(2)O) nanoparticle thin films from [Ir(OH)(6)](2-) solutions is reported. The [Ir(OH)(6)](2-) solution, made by alkaline hydrolysis of [IrCl(6)](2-), is colorless and stable near neutral pH, and forms blue IrO(x)·nH(2)O nanoparticle suspensions once it is adjusted to acidic or basic conditions. IrO(x)·nH(2)O nanoparticle thin films are grown anodically on glassy carbon, fluorine-doped tin oxide, and gold electrodes by electrolyzing [Ir(OH)(6)](2-) solutions at +1.0-1.3 V versus Ag/AgCl. The thickness of the IrO(x)·nH(2)O films can be controlled by varying the concentration of [Ir(OH)(6)](2-) , the deposition potential, and/or the deposition time. These thin films are stable between pH 1 and 13 and have the lowest overpotential (η) for the oxygen evolution reaction (OER) of any yet reported. Near neutral pH, the Tafel slope for the OER at a IrO(x)·nH(2)O film/Au rotating disk electrode was 37-39 mV per decade. The exchange current density for the OER was 4-8 × 10(-10) A cm(-2) at a 4 mC cm(-2) coverage of electroactive Ir.

  1. Optical properties of one-dimensional photonic crystals based on porous films of anodic aluminum oxide

    Science.gov (United States)

    Gorelik, V. S.; Klimonsky, S. O.; Filatov, V. V.; Napolskii, K. S.

    2016-04-01

    The optical properties of one-dimensional photonic crystals based on porous anodic aluminum oxide films have been studied by measuring transmittance and specular reflectance spectra in the visible and UV spectral regions. Angular dependences of the spectral positions of optical stop bands are obtained. It is shown that the reflectance within the first stop band varies from point to point on the sample surface, reaching a level of 98-99% at some points. The dispersion relation for electromagnetic waves in the model of infinite periodic structure is calculated for the samples under study. The possibility of using models with an infinite or finite number of layers to calculate reflectance spectra near the first optical stop band is discussed.

  2. Lead migration from toys by anodic stripping voltammetry using a bismuth film electrode.

    Science.gov (United States)

    Leal, M Fernanda C; Catarino, Rita I L; Pimenta, Adriana M; Souto, M Renata S; Afonso, Christelle S; Fernandes, Ana F Q

    2016-09-02

    Metals may be released from toys via saliva during mouthing, via sweat during dermal contact, or via gastric and intestinal fluids after partial or whole ingestion. In this study, we determined the lead migration from toys bought on the Portuguese market for children below 3 years of age. The lead migration was performed according to the European Committee for Standardization EN 71-3, which proposes a 2-hour migration test that simulates human gastric conditions. The voltammetric determination of migrated lead was performed by anodic stripping voltammetry (ASV) at a bismuth film electrode (BiFE). For all the analyzed toys, the values of migrated lead did not exceed the limits imposed by the European Committee for Standardization EN 71-3 (90 mg kg(-1)) and by the EU Directive 2009/48/EC (13.5 mg kg(-1)) on the safety of toys.

  3. 锂离子电池Sn基合金负极材料%Tin-Based Alloy Anode Materials for Lithium Ion Batteries

    Institute of Scientific and Technical Information of China (English)

    褚道葆; 李建; 袁希梅; 李自龙; 魏旭; 万勇

    2012-01-01

    Development of high safety, high energy, low cost and long service life Li ion rechargeable batteries is current a tremendous challenge for power battery application. The performance of the battery mainly depends on the nature of anode and cathode materials. Tin-based alloy is an industrially promising anode material for lithium ion batteries due to its high energy capacity and safety characteristics. In this review, the recent progress in Sn-based alloy anode materials for lithium ion batteries are reviewed. The different preparation methods of Sn- based alloy anodes are summarized. This review focuses on the problems in electrochemical properties of the Sn- based alloy anode and their causes, including the effect of loss of active material, SEI film and oxide film formation, aggregation of alloy particles and generation of dead lithium in the process of the intercalation of lithium ions on the charge and discharge performance of the alloy anode. The research trends in improving the electrochemical performance of the Sn-based alloy anode are prospected.%发展高安全性、高能量、低成本、长寿命锂离子电池是当前动力电池应用面临的巨大挑战。电池的性能主要取决于正负极电极材料的性能。Sn基合金负极具有高能量和安全特性,是一种很有产业化前景的锂离子电池负极材料。本文综述了Sn基合金电极作为锂离子电池负极的最新研究进展,对Sn基合金负极的不同制备方法进行了总结,重点介绍了锡基合金负极材料在电化学性能方面所存在的问题及其原因,包括锡基活性物质的损失、SEI膜和氧化膜的形成、纳米粒子的团聚和锂离子嵌入过程中死锂的产生等影响合金充放电性能的因素,最后展望了以提高Sn基合金负极电化学性能为目的的研究趋势。

  4. Review on recent progress of nanostructured anode materials for Li-ion batteries

    KAUST Repository

    Goriparti, Subrahmanyam

    2014-07-01

    This review highlights the recent research advances in active nanostructured anode materials for the next generation of Li-ion batteries (LIBs). In fact, in order to address both energy and power demands of secondary LIBs for future energy storage applications, it is required the development of innovative kinds of electrodes. Nanostructured materials based on carbon, metal/semiconductor, metal oxides and metal phosphides/nitrides/sulfides show a variety of admirable properties for LIBs applications such as high surface area, low diffusion distance, high electrical and ionic conductivity. Therefore, nanosized active materials are extremely promising for bridging the gap towards the realization of the next generation of LIBs with high reversible capacities, increased power capability, long cycling stability and free from safety concerns. In this review, anode materials are classified, depending on their electrochemical reaction with lithium, into three groups: intercalation/de-intercalation, alloy/de-alloy and conversion materials. Furthermore, the effect of nanoscale size and morphology on the electrochemical performance is presented. Synthesis of the nanostructures, lithium battery performance and electrode reaction mechanisms are also discussed. To conclude, the main aim of this review is to provide an organic outline of the wide range of recent research progresses and perspectives on nanosized active anode materials for future LIBs.

  5. Laser-Ultrasonic Measurement of Elastic Properties of Anodized Aluminum Coatings

    Science.gov (United States)

    Singer, F.

    Anodized aluminum oxide plays a great role in many industrial applications, e.g. in order to achieve greater wear resistance. Since the hardness of the anodized films strongly depends on its processing parameters, it is important to characterize the influence of the processing parameters on the film properties. In this work the elastic material parameters of anodized aluminum were investigated using a laser-based ultrasound system. The anodized films were characterized analyzing the dispersion of Rayleigh waves with a one-layer model. It was shown that anodizing time and temperature strongly influence Rayleigh wave propagation.

  6. Effects of laminating and co-firing conditions on the performance of anode-supported Ce0.8Sm0.201.9 film electrolyte

    Directory of Open Access Journals (Sweden)

    Li X.

    2011-01-01

    Full Text Available In order to evaluate the laminating and co-firing technique on the performance of anode-supported Ce0.8Sm0.2O1.9 (SDC film electrolyte and its single cell, NiO-YSZ and NiOSDC anode-supported SDC film electrolytes were fabricated by laminating 24 sheets of anode plus one sheet of electrolyte and co-firing. La0.4Sr0.6Co0.2Fe0.8O3-δ (LSCF-SDC cathode was coated on the SDC electrolytes to form a single cell. The lamination was tried at different laminating temperatures and pressures and the co-firing was carried out at different temperatures. The results showed that the laminating temperature should above the glass transition temperature (Tg of the binder. The laminating pressure of 70 MPa resulted in warp of the samples. The best co-firing temperature of the anode-supported SDC film electrolyte was 1400°C. The SDC film electrolyte formed well adherence to the anode. The NiO-YSZ anode had larger flexural strength than the NiO-SDC anode. The NiO-YSZ anode-supported SDC film electrolyte single cell had an open circuit voltage of 0.803 V and a maximum power density of 93.03 mW/cm2 with hydrogen as fuel at 800°C.

  7. Fabrication and characterization of anodic oxide films on a Ti-10V-2Fe-3Al titanium alloy

    Institute of Scientific and Technical Information of China (English)

    Jian-hua Liu; Jun-lan Yi; Song-mei Li; Mei Yu; Yong-zhen Xu

    2009-01-01

    Anodic oxide films of the titanium alloy Ti-10V-2Fe-3Al in ammonium tartrate electrolyte without hydrofluoric acid or fluoride were fabricated.The morphology,components,and microstructure of the films were characterized by scanning electron mi-croscopy (SEM),X-ray photoelectron spectroscopy (XPS),X-ray diffraction (XRD),and Raman spectroscopy.The results showed that the films were thick,uniform,and nontransparent.Such films exhibited sedimentary morphology,with a thickness of about 3 μm,and the pore diameters of the deposits ranged from several hundred nanometers to 1.5 μm.The films were mainly titanium dioxide.Some coke-like deposits,which may contain or be changed by OH,NH,C-C,C-O,and C=O groups,were doped in the firms.The films were mainly amorphous with a small amount of anatase and rutile phase.

  8. Processing silicon microparticles recycled from wafer waste via Rapid Thermal Process for lithium-ion battery anode materials

    Science.gov (United States)

    Tan, Hui-Gee; Duh, Jenq-Gong

    2016-12-01

    A vast quantity of waste sludge is generated during the silicon wafers slicing process in semiconductor and photovoltaic industries. Turning the waste powder into high-value products is of strategic importance for industrial processes. The purified Si microparticles (Si-MP) are recycled by a simple and fast procedure, Rapid Thermal Process (RTP). A prominent anodic material of Si-MP/Carbon composite with porous structure is obtained via in-spaced carbonization of water-soluble binder sodium carboxymethyl cellulose during RTP. This strategy provides buffer space, which is constructed by carbon porous continuous conductive framework throughout the entire electrode, to resist local stress and intense volume variation. In addition, a sufficiently electrochemically stable solid-electrolyte interphase layer is accomplished with the coating of SiOx film and amorphous carbon on the surface of Si-MP. Under these circumstances, the enhanced electrodes achieve a first cycle efficiency of approximately 80% and a reversible charge capacity of 800 mAhg-1 over 100 cycles at 0.5 Ag-1 with good retention. Through a green and simple procedure, a remarkable Si-MP embedded carbon-matrix with porous structure is established to achieve commercially high performance Si-MP/C composite anodes and also to resolve the issues of waste disposal.

  9. Novel Composite Thick-Film Electrodes Consisted of Zinc Oxide and Silicon for Lithium-Ion Battery Anode

    OpenAIRE

    Usui, Hiroyuki; Kono, Takamasa; Sakaguchi, Hiroki

    2012-01-01

    As a novel anode for Li-ion battery, ZnO/Si composite thick-film electrodes with various ratios of ZnO:Si were prepared by a gas-deposition method using a commercial Si powder and a radial-shaped ZnO powder synthesized by a precipitation method. We investigated the effect of the ZnO amount and the radial morphology on the anode performance, comparing with charge–discharge properties of a ZnO electrode without Si. The ZnO electrode showed a stable cyclability and a moderate discharge capacity ...

  10. High capacity anode materials for lithium - ion batteries

    OpenAIRE

    Kudu, Ömer Ulaş

    2017-01-01

    Cataloged from PDF version of article. Thesis (M.S.): Bilkent University, Department of Materials Science and Nanotechnology, İhsan Doğramacı Bilkent University, 2017. Includes bibliographical references (leaves 76-87). Huge energy demand in the world has caused depletion in non - renewable energy sources, and global climate change due to the consumed fuel exhausts. Renewable energy sources are eco - friendly alternatives. Electrochemical energy storage systems (EESS) are useful tool...

  11. Effect of sodium tartrate concentrations on morphology and characteristics of anodic oxide film on titanium alloy Ti–10V–2Fe–3Al

    Directory of Open Access Journals (Sweden)

    Ma Kun

    2016-08-01

    Full Text Available The effect of sodium tartrate concentrations on morphology and characteristics of anodic oxide film on titanium alloy was investigated. The alloy substrates were anodized in different concentration solutions of sodium tartrate with the addition of PTFE emulsion and their morphology and characteristics were analyzed. The anodic oxide film presented a uniform petaloid drums and micro-cracks morphology. Additionally, micro-cracks dramatically swelled with the increase of the tartrate concentrations. The thickness of the anodic oxide film increased with the concentrations until the concentration reached 15 g/L. The results of Raman analysis illustrate that all samples have similarity in the crystal structure, consisting of mainly amorphous TiO2, some anatase TiO2 and a small amount of rutile TiO2. And the ratios of anatase TiO2 and rutile TiO2 increase with the concentrations until it reaches 15 g/L. Furthermore, the intensity of the peaks increases with enhanced concentrations until the concentration reaches 15 g/L. The corrosion resistance of the anodic oxide film is increased by the sodium tartrate with higher concentrations before 15 g/L. The coefficient of friction of the anodic oxide film reduces with the concentrations until the concentration reaches 15 g/L, then the coefficient of friction of the anodic oxide film increases with the concentrations.

  12. Suitability of new anode materials in mammography: dose and subject contrast considerations using Monte Carlo simulation.

    Science.gov (United States)

    Delis, H; Spyrou, G; Costaridou, L; Tzanakos, G; Panayiotakis, G

    2006-11-01

    Mammography is the technique with the highest sensitivity and specificity, for the early detection of nonpalpable lesions associated with breast cancer. As screening mammography refers to asymptomatic women, the task of optimization between the image quality and the radiation dose is critical. A way toward optimization could be the introduction of new anode materials. A method for producing the x-ray spectra of different anode/filter combinations is proposed. The performance of several mammographic spectra, produced by both existing and theoretical anode materials, is evaluated, with respect to their dose and subject contrast characteristics, using a Monte Carlo simulation. The mammographic performance is evaluated utilizing a properly designed mathematical phantom with embedded inhomogeneities, irradiated with different spectra, based on combinations of conventional and new (Ru, Ag) anode materials, with several filters (Mo, Rh, Ru, Ag, Nb, Al). An earlier developed and validated Monte Carlo model, for deriving both image and dose characteristics in mammography, was utilized and overall performance results were derived in terms of subject contrast to dose ratio and squared subject contrast to dose ratio. Results demonstrate that soft spectra, mainly produced from Mo, Rh, and Ru anodes and filtered with k-edge filters, provide increased subject contrast for inhomogeneities of both small size, simulating microcalcifications and low density, simulating masses. The harder spectra (W and Ag anode) come short in the discrimination task but demonstrate improved performance when considering the dose delivered to the breast tissue. As far as the overall performance is concerned, new theoretical spectra demonstrate a noticeable good performance that is similar, and in some cases better compared to commonly used systems, stressing the possibility of introducing new materials in mammographic practice as a possible contribution to its optimization task. In the overall

  13. Alloy-Based Anode Materials toward Advanced Sodium-Ion Batteries.

    Science.gov (United States)

    Lao, Mengmeng; Zhang, Yu; Luo, Wenbin; Yan, Qingyu; Sun, Wenping; Dou, Shi Xue

    2017-06-28

    Sodium-ion batteries (SIBs) are considered as promising alternatives to lithium-ion batteries owing to the abundant sodium resources. However, the limited energy density, moderate cycling life, and immature manufacture technology of SIBs are the major challenges hindering their practical application. Recently, numerous efforts are devoted to developing novel electrode materials with high specific capacities and long durability. In comparison with carbonaceous materials (e.g., hard carbon), partial Group IVA and VA elements, such as Sn, Sb, and P, possess high theoretical specific capacities for sodium storage based on the alloying reaction mechanism, demonstrating great potential for high-energy SIBs. In this review, the recent research progress of alloy-type anodes and their compounds for sodium storage is summarized. Specific efforts to enhance the electrochemical performance of the alloy-based anode materials are discussed, and the challenges and perspectives regarding these anode materials are proposed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Manganese pyridinedicarboxylates: New anode materials for lithium-ion batteries with good cycling performance

    Energy Technology Data Exchange (ETDEWEB)

    Fei, Hailong, E-mail: feilin09053@gmail.com [College of Chemistry, Fuzhou University, 2 Xueyuan Road, University Town Fuzhou, Fujian 350116 (China); Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071 (China); Li, Zhiwei; Liu, Xin [College of Chemistry, Fuzhou University, 2 Xueyuan Road, University Town Fuzhou, Fujian 350116 (China)

    2015-08-15

    Highlights: • Manganese 2,3-pyridinedicarboxylate and 2,5-pyridinedicarboxylate. • Firstly tested as anode materials. • High capacity and good cycle stability. - Abstract: It is significant to discover new environmental friendly, sustainable and renewable electrode materials for lithium-ion batteries. Manganese dicarboxylate [Mn{sub 2}(pdc){sub 2}(H{sub 2}O){sub 3}]{sub n}⋅2nH{sub 2}O (pdc = pyridine-2,3-dicarboxylate) is firstly found to be a high-energy anode material for lithium-ion batteries. It shows a high discharge capacity of 573.7 mA h g{sup −1} for the second cycle between a 0.05 and 3.0 V voltage limit at a discharge current density of 500 mA g{sup −1}. The reversible capacity of 457.2 mA h g{sup −1} is remained after 100 cycles with a capacity retention being 79.6%. In addition, it is found that Mn 2,5-pyridinedicarboxyle was also stable anode materials with high capacity.

  15. Electrochemical performances of Al-based composites as anode materials for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Chen Zhongxue; Qian Jiangfeng; Ai Xinping [Hubei Key Lab. of Electrochemical Power Sources, Department of Chemistry, Wuhan University, Wuhan 430072 (China); Cao Yuliang [Hubei Key Lab. of Electrochemical Power Sources, Department of Chemistry, Wuhan University, Wuhan 430072 (China)], E-mail: ylcao@whu.edu.cn; Yang Hanxi [Hubei Key Lab. of Electrochemical Power Sources, Department of Chemistry, Wuhan University, Wuhan 430072 (China)

    2009-06-30

    Al-C, Al-Fe and Al-Fe-C composite materials have been prepared by high-energy ball milling technique. The electrochemical measurements demonstrated that the Al-Fe-C composites have greatly improved electrochemical performances in comparison with Al, Al-C and Al-Fe anode. For example, Al{sub 71}Fe{sub 9}C{sub 20} can deliver the reversible capacity of 436 mAh g{sup -1} at first cycle and 255 mAh g{sup -1} at 15th cycle. This improved electrochemical performance could be attributed to the alloying formation of Al with Fe and the buffering effect by the graphite matrix. This suggests that the Al-Fe-C composite has a potential possibility to be developed as an anode material for lithium-ion batteries.

  16. Relationship between initial efficiency and structure parameters of carbon anode material for Li-ion battery

    Institute of Scientific and Technical Information of China (English)

    SHEN Jian-bin; TANG You-gen; LIANG Yi-zeng; TAN Xin-xin

    2008-01-01

    The initial efficiency is a very important criterion for carbon anode material of Li-ion battery. The relationship between initial efficiency and structure parameters of carbon anode material of Li-ion battery was investigated by an artificial intelligence approach called Random Forests using D10, D50, D90, BET specific surface area and TP density as inputs, initial efficiency as output.The results give good classification performance with 91% accuracy. The variable importance analysis results show the impact of 5 variables on the initial efficiency descends in the order of D90, TP density, BET specific surface area, D50 and D10; smaller D90 and larger TP density have positive impact on initial efficiency. The contribution of BET specific surface area on classification is only 18.74%, which indicates the shortcoming of BET specific surface area as a widely used parameter for initial efficiency evaluation.

  17. Facile synthesis of one-dimensional zinc vanadate nanofibers for high lithium storage anode material

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Lei [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); International Joint Research Laboratory for Advanced Functional Textile Materials, Jiangnan University, Wuxi 214122 (China); Fei, Yaqian; Chen, Ke; Li, Dawei; Wang, Xin [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); Wang, Qingqing [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); International Joint Research Laboratory for Advanced Functional Textile Materials, Jiangnan University, Wuxi 214122 (China); Wei, Qufu, E-mail: qfwei@jiangnan.edu.cn [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); International Joint Research Laboratory for Advanced Functional Textile Materials, Jiangnan University, Wuxi 214122 (China); Qiao, Hui [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China)

    2015-11-15

    One-dimensional (1D) zinc vanadate (α-Zn{sub 2}V{sub 2}O{sub 7}) nanofibers have been synthesized through electrospinning combined with an annealing process. When used as anode material for lithium-ion batteries (LIBs), electrospun 1D α-Zn{sub 2}V{sub 2}O{sub 7} nanofibers exhibit a reversible capacity of ∼708 mAh g{sup −1} after 100 cycles at a current density of 50 mA g{sup −1}. A good rate capability is also achieved even at higher current densities. When cycled at a current density of 2000 mA g{sup −1}, the electrode can still show a reversible capacity of ∼311 mAh g{sup −1}. The excellent cycle performance and rate capability may be due to the 1D nanofiber architectures, mesoporous structures, and relatively large specific surface area, which can provide a short ion diffusion path and continuous electron transportation. Therefore, this work presents a simple and efficient approach for fabrication of 1D α-Zn{sub 2}V{sub 2}O{sub 7} nanofibers, which are promising high-performance anode materials for LIBs. - Highlights: • Electrospun 1D α-Zn{sub 2}V{sub 2}O{sub 7} nanofibers are first synthesized for anode material. • The electrochemical reaction mechanism of this material is discussed. • A reversible capacity of ∼708 mAh g{sup −1} is obtained after 100 cycles at 50 mA g{sup −1}. • 1D α-Zn{sub 2}V{sub 2}O{sub 7} nanofiber anodes show excellent rate capability for LIBs.

  18. FY-16 Technology Gap Study Technical Report: Analysis of Undissolved Anode Materials of Mark-IV Electrorefiner

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Tae-Sic [Idaho National Lab. (INL), Idaho Falls, ID (United States); Vaden, DeeEarl [Idaho National Lab. (INL), Idaho Falls, ID (United States); Westphal, Brian Robert [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-01-01

    The Experimental Breeder Reactor II (EBR-II) is a sodium cooled fast reactor developed at Argonne National Laboratory (ANL). The used fuels from the EBR-II are currently being treated in the Fuel Conditioning Facility (FCF) at the Idaho National Laboratory (INL). The Mark IV (Mk-IV) electrorefiner (ER) is a unit process in the FCF, which is primarily assigned to treating the used driver fuels. The stainless steel anode baskets hold the chopped spent driver fuel segments. During electrorefining, the anode baskets are immersed into the electrolyte and the used fuel is dissolved electrochemically. Perforated sides and bottoms allow the flow of the electrolyte into and out of the anode baskets. The steel cathode is also immersed into the electrolyte and collects the reduced products. The active metal contents in the used fuel (e.g., Cs, Sr, lanthanides, Pu, etc.) reacts with uranium cations in the electrolyte and progressively reports to the electrolyte. Noble metals are mostly retained in the cladding hulls. Varying quantities of zirconium are retained in the cladding hulls depending on the operational conditions of the Mk-IV ER. The undissolved anode materials are removed from the anode baskets and stored for subsequent metal waste form processing. These undissolved materials typically include undissolved fuels, stainless steel cladding, and adhering electrolyte. A couple of hulls are retrieved for chemical analysis and used for estimating the composition of the entire undissolved anode materials. The mass balance attempt based on this practice of estimating the undissolved anode materials has been a challenge due to inherently high sampling errors associated with heterogeneous undissolved material compositions. Responding to the prescribed challenge, this report investigates chemical analysis data as a whole and finds noticeable trends in the compositions of undissolved anode material samples with respect to the mass of the whole undissolved anode materials. Based

  19. Enhancement of Electrochemical Stability about Silicon/Carbon Composite Anode Materials for Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Wei Xiao

    2015-01-01

    Full Text Available Silicon/carbon (Si/C composite anode materials are successfully synthesized by mechanical ball milling followed by pyrolysis method. The structure and morphology of the composite are characterized by X-ray diffraction and scanning electron microscopy and transmission electron microscope, respectively. The results show that the composite is composed of Si, flake graphite, and phenolic resin-pyrolyzed carbon, and Si and flake graphite are enwrapped by phenolic resin-pyrolyzed carbon, which can provide not only a good buffering matrix but also a conductive network. The Si/C composite also shows good electrochemical stability, in which the composite anode material exhibits a high initial charge capacity of 805.3 mAh g−1 at 100 mA g−1 and it can still deliver a high charge capacity of 791.7 mAh g−1 when the current density increases to 500 mA g−1. The results indicate that it could be used as a promising anode material for lithium ion batteries.

  20. Recovery of valuable metals from anode material of hydrogen-nickel battery

    Institute of Scientific and Technical Information of China (English)

    WU Fang; XU Sheng-ming; LI Lin-yan; CHEN Song-zhe; XU Gang; XU Jing-ming

    2009-01-01

    Simultaneous recovery of rare earth, nickel and cobalt resources from the anode material of hydrogen-nickel battery was performed through a hydrometallurgical process. Most of rare earth elements are separated from nickel and cobalt in the form of sulfates when the anode material is firstly leached with sulfuric acid. Then, the precipitated rare earth sulfates are dissolved with sodium hydroxide to form rare earth hydroxides. The rare earth element, zinc and manganese ions in the lixivium are also separated from nickel and cobalt by using PC-88A extractant system, and the organic phase loaded rare earth is stripped with hydrochloric acid. By neutralizing the stripping solution with rare earth hydroxide, the rare earth chloride is obtained. Under the suitable leaching conditions of sulfuric acid 3 mol/L, leaching time 4 h and temperature 95 ℃, 94.5% of rare earth in the anode material is transformed into the sulfate precipitates, and the leaching ratios of nickel and cobalt can approach 99.5%. When the pH value of the extractive system is controlled in the range of 3.0-3.5, the rare earth elements in the lixivium can be extracted completely into the organic phase, and the stripping recovery of the rare earth can reach 98% in the extraction stage. The total recoveries of rare earth, nickel and cobalt are 98.9%, 98.4% and 98.5%, respectively.

  1. All-carbon-based porous topological semimetal for Li-ion battery anode material.

    Science.gov (United States)

    Liu, Junyi; Wang, Shuo; Sun, Qiang

    2017-01-24

    Topological state of matter and lithium batteries are currently two hot topics in science and technology. Here we combine these two by exploring the possibility of using all-carbon-based porous topological semimetal for lithium battery anode material. Based on density-functional theory and the cluster-expansion method, we find that the recently identified topological semimetal bco-C16 is a promising anode material with higher specific capacity (Li-C4) than that of the commonly used graphite anode (Li-C6), and Li ions in bco-C16 exhibit a remarkable one-dimensional (1D) migration feature, and the ion diffusion channels are robust against the compressive and tensile strains during charging/discharging. Moreover, the energy barrier decreases with increasing Li insertion and can reach 0.019 eV at high Li ion concentration; the average voltage is as low as 0.23 V, and the volume change during the operation is comparable to that of graphite. These intriguing theoretical findings would stimulate experimental work on topological carbon materials.

  2. Bismuth Nanoparticles Embedded in Carbon Spheres as Anode Materials for Sodium/Lithium-Ion Batteries.

    Science.gov (United States)

    Yang, Fuhua; Yu, Fan; Zhang, Zhian; Zhang, Kai; Lai, Yanqing; Li, Jie

    2016-02-12

    Sodium-ion batteries (SIBs) are regarded as an attractive alternative to lithium-ion batteries (LIBs) for large-scale commercial applications, because of the abundant terrestrial reserves of sodium. Exporting suitable anode materials is the key to the development of SIBs and LIBs. In this contribution, we report on the fabrication of Bi@C microspheres using aerosol spray pyrolysis technique. When used as SIBs anode materials, the Bi@C microsphere delivered a high capacity of 123.5 mAh g(-1) after 100 cycles at 100 mA g(-1) . The rate performance is also impressive (specific capacities of 299, 252, 192, 141, and 90 mAh g(-1) are obtained under current densities of 0.1, 0.2, 0.5, 1, and 2 A g(-1) , respectively). Furthermore, the Bi@C microsphere also proved to be suitable LIB anode materials. The excellent electrochemical performance for both SIBs and LIBs can attributed to the Bi@C microsphere structure with Bi nanoparticles uniformly dispersed in carbon spheres. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Study on the fabrication of back surface reflectors in nano-crystalline silicon thin-film solar cells by using random texturing aluminum anodization

    Science.gov (United States)

    Shin, Kang Sik; Jang, Eunseok; Cho, Jun-Sik; Yoo, Jinsu; Park, Joo Hyung; Byungsung, O.

    2015-09-01

    In recent decades, researchers have improved the efficiency of amorphous silicon solar cells in many ways. One of the easiest and most practical methods to improve solar-cell efficiency is adopting a back surface reflector (BSR) as the bottom layer or as the substrate. The BSR reflects the incident light back to the absorber layer in a solar cell, thus elongating the light path and causing the so-called "light trapping effect". The elongation of the light path in certain wavelength ranges can be enhanced with the proper scale of BSR surface structure or morphology. An aluminum substrate with a surface modified by aluminum anodizing is used to improve the optical properties for applications in amorphous silicon solar cells as a BSR in this research due to the high reflectivity and the low material cost. The solar cells with a BSR were formed and analyzed by using the following procedures: First, the surface of the aluminum substrate was degreased by using acetone, ethanol and distilled water, and it was chemically polished in a dilute alkali solution. After the cleaning process, the aluminum surface's morphology was modified by using a controlled anodization in a dilute acid solution to form oxide on the surface. The oxidized film was etched off by using an alkali solution to leave an aluminum surface with randomly-ordered dimple-patterns of approximately one micrometer in size. The anodizing conditions and the anodized aluminum surfaces after the oxide layer had been removed were systematically investigated according to the applied voltage. Finally, amorphous silicon solar cells were deposited on a modified aluminum plate by using dc magnetron sputtering. The surfaces of the anodized aluminum were observed by using field-emission scanning electron microscopy. The total and the diffuse reflectances of the surface-modified aluminum sheets were measured by using UV spectroscopy. We observed that the diffuse reflectances increased with increasing anodizing voltage. The

  4. Fabrication of TiO{sub 2} nanotubes by anodization of Ti thin films for VOC sensing

    Energy Technology Data Exchange (ETDEWEB)

    K Latin-Small-Letter-Dotless-I l Latin-Small-Letter-Dotless-I nc, N.; Sennik, E. [Gebze Institute of Technology, Faculty of Science, Department of Physics, 41400 Kocaeli (Turkey); Oeztuerk, Z.Z., E-mail: zozturk@gyte.edu.tr [Gebze Institute of Technology, Faculty of Science, Department of Physics, 41400 Kocaeli (Turkey); TUeBITAK-Marmara Research Center, Materials Institute, 41470 Gebze-Kocaeli (Turkey)

    2011-11-30

    Ti thin films were anodized in aqueous HF (0.5 wt.%) and in polar organic (0.5 wt.% NH{sub 4}F + ethylene glycol) electrolytes to form TiO{sub 2} nanotube arrays. Ti thin films were deposited on microscope glass substrates and then anodized. Anodization was performed at potentials ranging from 5 V to 20 V for the aqueous HF and from 20 V to 60 V for the polar organic electrolytes over the temperatures range from 0 to 20 Degree-Sign C. The TiO{sub 2} nanotubes were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX). It has been observed that anodization of the deposited Ti thin films with aqueous HF solution at 0 Degree-Sign C resulted in nanotube-type structures with diameters in the range of 30-80 nm for an applied voltage of 10 V. In addition, the nanotube-type structure is observed for polar organic electrolyte at room temperature at the anodization voltage higher than 40 V. The volatile organic compound (VOC) sensing properties of TiO{sub 2} nanotubes fabricated using different electrolytes were investigated at 200 Degree-Sign C. The maximum sensor response is obtained for carbon tetrachloride. The sensor response is dependent on porosity of TiO{sub 2}. The highest sensor response is observed for TiO{sub 2} nanotubes which are synthesized using aqueous HF electrolyte and have very high porosity.

  5. Evidence and analysis of parallel growth mechanisms in Cu{sub 2}O films prepared by Cu anodization

    Energy Technology Data Exchange (ETDEWEB)

    Caballero-Briones, F., E-mail: fcaballerobriones@ub.ed [Department of Physical Chemistry, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); CIBER-BBN, Maria de Luna 11, 50018 Zaragoza (Spain); Palacios-Padros, A. [Department of Physical Chemistry, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); Calzadilla, O. [Facultad de Fisica, Universidad de La Habana, San Lazaro y L, Colina Universitaria, 10400 Vedado, La Habana (Cuba); Sanz, Fausto, E-mail: fsanz@ub.ed [Institute for Bioengineering of Catalonia (IBEC), Edifici Helix, Baldiri i Reixac 15-21, 08028 Barcelona (Spain); Department of Physical Chemistry, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); CIBER-BBN, Maria de Luna 11, 50018 Zaragoza (Spain)

    2010-05-30

    We have studied the preparation of Cu{sub 2}O films by copper anodization in a 0.1 M NaOH electrolyte. We identified the potential range at which Cu{sup +} dissolution takes place then we prepared films with different times of exposure to this potential. The morphology, crystalline structure, band gap, Urbach energy and thickness of the films were studied. Films prepared with the electrode unexposed to the dissolution potential have a pyramidal growth typical of potential driven processes, while samples prepared at increasing exposure times to dissolution potential present continuous nucleation, growth and grain coalescence. We observed a discrepancy in the respective film thicknesses calculated by coulometry, atomic force microscopy and optical reflectance. We propose that anodic Cu{sub 2}O film formation involves three parallel mechanisms (i) Cu{sub 2}O nucleation at the surface, (ii) Cu{sup +} dissolution followed by heterogeneous nucleation and (iii) Cu{sup +} and OH{sup -} diffusion through the forming oxide and subsequent reaction in the solid state.

  6. Solid oxide fuel cell anode surface modification by magnetron sputtering of NiO/YSZ thin film

    Science.gov (United States)

    Solovyev, A. A.; Shipilova, A. V.; Ionov, I. V.; Smolyanskiy, E. A.; Lauk, A. L.; Kovalchuk, A. N.; Remnev, G. E.; Lebedynskiy, A. M.

    2017-05-01

    NiO/ZrO2-Y2O3 (NiO/YSZ) anode functional layers (AFL) with 16-60 vol.% of NiO were deposited onto NiO/YSZ anode substrates by magnetron sputtering, followed by annealing in air at 1200 °C. The optimal deposition conditions for NiO/YSZ were determined. NiO content in the films was varied by changing the oxygen flow rate during the sputtering process. The microstructure and phase composition of NiO/YSZ anode functional layer were studied by SEM and XRD methods. Anode functional layers were fully crystallized and comprised of grains up to 500 nm in diameter after reduction in hydrogen. Anode-supported solid oxide fuel cells (SOFC) with the diameter of 20 mm including the magnetron sputtered AFL, 4-microns thick YSZ electrolyte and La0.6Sr0.4Co0.2Fe0.8O3/Ce0.9Gd0.1O2 (LSCF/CGO) cathode were fabricated and tested. Electrochemical properties of the single fuel cells were investigated as a function of NiO volume content in AFL and AFL thickness.

  7. Strategies Based on Nitride Materials Chemistry to Stabilize Li Metal Anode.

    Science.gov (United States)

    Zhu, Yizhou; He, Xingfeng; Mo, Yifei

    2017-08-01

    Lithium metal battery is a promising candidate for high-energy-density energy storage. Unfortunately, the strongly reducing nature of lithium metal has been an outstanding challenge causing poor stability and low coulombic efficiency in lithium batteries. For decades, there are significant research efforts to stabilize lithium metal anode. However, such efforts are greatly impeded by the lack of knowledge about lithium-stable materials chemistry. So far, only a few materials are known to be stable against Li metal. To resolve this outstanding challenge, lithium-stable materials have been uncovered out of chemistry across the periodic table using first-principles calculations based on large materials database. It is found that most oxides, sulfides, and halides, commonly studied as protection materials, are reduced by lithium metal due to the reduction of metal cations. It is discovered that nitride anion chemistry exhibits unique stability against Li metal, which is either thermodynamically intrinsic or a result of stable passivation. The results here establish essential guidelines for selecting, designing, and discovering materials for lithium metal protection, and propose multiple novel strategies of using nitride materials and high nitrogen doping to form stable solid-electrolyte-interphase for lithium metal anode, paving the way for high-energy rechargeable lithium batteries.

  8. Tungsten-doped thin film materials

    Science.gov (United States)

    Xiang, Xiao-Dong; Chang, Hauyee; Gao, Chen; Takeuchi, Ichiro; Schultz, Peter G.

    2003-12-09

    A dielectric thin film material for high frequency use, including use as a capacitor, and having a low dielectric loss factor is provided, the film comprising a composition of tungsten-doped barium strontium titanate of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3, where X is between about 0.5 and about 1.0. Also provided is a method for making a dielectric thin film of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3 and doped with W, where X is between about 0.5 and about 1.0, a substrate is provided, TiO.sub.2, the W dopant, Ba, and optionally Sr are deposited on the substrate, and the substrate containing TiO.sub.2, the W dopant, Ba, and optionally Sr is heated to form a low loss dielectric thin film.

  9. Photo-induced properties of non-annealed anatase TiO{sub 2} mesoporous film prepared by anodizing in the hot phosphate/glycerol electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Taguchi, Yoshiaki [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Tsuji, Etsushi, E-mail: e-tsuji@eng.hokudai.ac.jp [Division of Materials Chemistry, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Aoki, Yoshitaka; Habazaki, Hiroki [Division of Materials Chemistry, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer The TiO{sub 2} mesoporous film can be formed by anodizing of titanium specimens in the hot phosphate/glycerol electrolyte. Black-Right-Pointing-Pointer The mesoporous film formed at 20 V without annealing was a mixture of amorphous phase and nanograined anatase, which clearly showed strong Left-Pointing-Angle-Bracket 0 0 1 Right-Pointing-Angle-Bracket preferred orientation. Black-Right-Pointing-Pointer Even without annealing, the as-anodized anatase TiO{sub 2} mesoporous film showed high photocatalytic activities for decomposition of water and methylene blue. Black-Right-Pointing-Pointer The as-anodized anatase TiO{sub 2} mesoporous film also showed superhydrophilicity with UV light irradiation. - Abstract: In this study, anatase crystalline TiO{sub 2} mesoporous film was formed by anodizing of titanium specimens without annealing procedures. The specimens were anodized at 3 and 20 V in 0.6 mol dm{sup -3} K{sub 2}HPO{sub 4} and 0.2 mol dm{sup -3} K{sub 3}PO{sub 4}/glycerol electrolyte at 433 K. The obtained films had mesoporous structures with pore diameters as small as {approx}10 nm. The mesoporous film formed at 20 V without annealing (MP-20V) was a mixture of amorphous phase and nanograined anatase, which clearly showed strong Left-Pointing-Angle-Bracket 0 0 1 Right-Pointing-Angle-Bracket preferred orientation, whereas that at 3 V was completely amorphous. Even without annealing, the MP-20V showed high photocatalytic activities for decomposition of water and methylene blue. In contrast, the anodic TiO{sub 2} nanotube film formed in NH{sub 4}F/ethylene glycol electrolyte revealed photocatalytic activities only after annealing at 723 K, because of the amorphous nature of the as-anodized nanotube film. The MP-20V film also showed superhydrophilicity with UV light irradiation.

  10. Vanadium-based polyoxometalate as new material for sodium-ion battery anodes

    Science.gov (United States)

    Hartung, Steffen; Bucher, Nicolas; Chen, Han-Yi; Al-Oweini, Rami; Sreejith, Sivaramapanicker; Borah, Parijat; Yanli, Zhao; Kortz, Ulrich; Stimming, Ulrich; Hoster, Harry E.; Srinivasan, Madhavi

    2015-08-01

    Affordable energy storage is crucial for a variety of technologies. One option is sodium-ion batteries (NIBs) for which, however, suitable anode materials are still a problem. We report on the application of a promising new class of materials, polyoxometalates (POMs), as an anode in NIBs. Specifically, Na6[V10O28]·16H2O is being synthesized and characterized. Galvanostatic tests reveal a reversible capacity of approximately 276 mA h g-1 with an average discharge potential of 0.4 V vs. Na/Na+, as well as a high cycling stability. The underlying mechanism is rationalized to be an insertion of Na+ in between the [V10O28]6- anions rather than an intercalation into a crystal structure; the accompanying reduction of V+V to V+IV is confirmed by X-ray Photoelectron Spectroscopy. Finally, a working full-cell set-up is presented with the POM as the anode, substantiating the claim that Na6[V10O28]·16H2O is a promising option for future high-performing sodium-ion batteries.

  11. Carbon matrix/SiNWs heterogeneous block as improved reversible anodes material for lithium ion batteries

    Institute of Scientific and Technical Information of China (English)

    Yao; Wang; Long; Ren; Yundan; Liu; Xuejun; Liu; Kai; Huang; Xiaolin; Wei; Jun; Li; Xiang; Qi; Jianxin; Zhong

    2014-01-01

    A novel carbon matrix/silicon nanowires(SiNWs) heterogeneous block was successfully produced by dispersing SiNWs into templated carbon matrix via a modified evaporation induced self-assembly method. The heterogeneous block was determined by X-ray diffraction, Raman spectra and scanning electron microscopy. As an anode material for lithium batteries, the block was investigated by cyclic voltammograms(CV), charge/discharge tests, galvanostatic cycling performance and A. C. impedance spectroscopy. We show that the SiNWs disperse into the framework, and are nicely wrapped by the carbon matrix. The heterogeneous block exhibits superior electrochemical reversibility with a high specific capacity of 529.3 mAh/g in comparison with bare SiNWs anode with merely about 52.6 mAh/g capacity retention. The block presents excellent cycle stability and capacity retention which can be attributed to the improvement of conductivity by the existence of carbon matrix and the enhancement of ability to relieve the large volume expansion of SiNWs during the lithium insertion/extraction cycle. The results indicate that the as-prepared carbon matrix/SiNWs heterogeneous block can be an attractive and potential anode material for lithium-ion battery applications.

  12. Determination of Antimony (III) in Real Samples by Anodic Stripping Voltammetry Using a Mercury Film Screen-Printed Electrode

    OpenAIRE

    Olga Domínguez-Renedo; M. Julia Arcos-Martínez; M. Jesús Gómez González

    2009-01-01

    This paper describes a procedure for the determination of antimony (III) by differential pulse anodic stripping voltammetry using a mercury film screen-printed electrode as the working electrode. The procedure has been optimized using experimental design methodology. Under these conditions, in terms of Residual Standard Deviation (RSD), the repeatability (3.81 %) and the reproducibility (5.07 %) of the constructed electrodes were both analyzed. The detection limit for Sb (III) was calculated ...

  13. Electrolytic deposition of Sn-coated mesocarbon microbeads as anode material for lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Min-Jen [Department of Materials Engineering, National Chung Hsing University, Taichung 40227, Taiwan (China); Jen-Teh Junior College of Medicine, Nursing and Management, Taiwan (China); Tsai, Du-Cheng [Department of Materials Engineering, National Chung Hsing University, Taichung 40227, Taiwan (China); Ho, Wen-Hsien [Taiwan Textile Research Institute, Taipei 23674, Taiwan (China); Li, Ching-Fei, E-mail: chingfei.li@gmail.com [Phoenix Silicon International Corporation, Hsinchu 30094, Taiwan (China); Shieu, Fuh-Sheng, E-mail: fsshieu@dragon.nchu.edu.tw [Department of Materials Engineering, National Chung Hsing University, Taichung 40227, Taiwan (China); Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung 40227, Taiwan (China)

    2013-11-15

    Deposited of crystalline tin (Sn) coatings on mesocarbon microbead (MCMB) powder as anodes of lithium ion (Li-ion) battery was conducted in the SnSO{sub 4} solution by a cathodic electrochemical synthesis. The Sn-coated MCMB specimens were characterized by X-ray diffraction, scanning electron microscopy, and charge/discharge tests. The synthesis condition of Sn-coated MCMB was optimized by considering the agglomeration, size, and adhesion of the samples to the current collectors in the battery. The Sn-coated MCMB electrodes exhibit increased reversible capacity without sacrificing its cycling behavior, compared with bare MCMB electrodes. It is concluded that electrolysis-deposited Sn-coated MCMB electrodes may emerge as a practical and promising anode material for secondary Li-ion batteries.

  14. Fluorine-Doped Tin Oxide Nanocrystal/Reduced Graphene Oxide Composites as Lithium Ion Battery Anode Material with High Capacity and Cycling Stability.

    Science.gov (United States)

    Xu, Haiping; Shi, Liyi; Wang, Zhuyi; Liu, Jia; Zhu, Jiefang; Zhao, Yin; Zhang, Meihong; Yuan, Shuai

    2015-12-16

    Tin oxide (SnO2) is a kind of anode material with high theoretical capacity. However, the volume expansion and fast capability fading during cycling have prevented its practical application in lithium ion batteries. Herein, we report that the nanocomposite of fluorine-doped tin oxide (FTO) and reduced graphene oxide (RGO) is an ideal anode material with high capacity, high rate capability, and high stability. The FTO conductive nanocrystals were successfully anchored on RGO nanosheets from an FTO nanocrystals colloid and RGO suspension by hydrothermal treatment. As the anode material, the FTO/RGO composite showed high structural stability during the lithiation and delithiation processes. The conductive FTO nanocrystals favor the formation of stable and thin solid electrolyte interface films. Significantly, the FTO/RGO composite retains a discharge capacity as high as 1439 mAhg(-1) after 200 cycles at a current density of 100 mAg(-1). Moreover, its rate capacity displays 1148 mAhg(-1) at a current density of 1000 mAg(-1).

  15. Recent advances in the development and utilization of modern anode materials for high performance microbial fuel cells.

    Science.gov (United States)

    Sonawane, Jayesh M; Yadav, Abhishek; Ghosh, Prakash C; Adeloju, Samuel B

    2017-04-15

    Microbial fuel cells (MFCs) are novel bio-electrochemical device for spontaneous or single step conversion of biomass into electricity, based on the use of metabolic activity of bacteria. The design and use of MFCs has attracted considerable interests because of the potential new opportunities they offer for sustainable production of energy from biodegradable and reused waste materials. However, the associated slow microbial kinetics and costly construction materials has limited a much wider commercial use of the technology. In the past ten years, there has been significant new developments in MFCs which has resulted in several-fold increase in achievable power density. Yet, there is still considerable possibility for further improvement in performance and development of new cost effective materials. This paper comprehensively reviews recent advances in the construction and utilization of novel anodes for MFCs. In particular, it highlights some of the critical roles and functions of anodes in MFCs, strategies available for improving surface areas of anodes, dominant performance of stainless-steel based anode materials, and the emerging benefits of inclusion of nanomaterials. The review also demonstrates that some of the materials are very promising for large scale MFC applications and are likely to replace conventional anodes for the development of next generation MFC systems. The hurdles to the development of commercial MFC technology are also discussed. Furthermore, the future directions in the design and selection of materials for construction and utilization of MFC anodes are highlighted. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Sol-gel Method Synthesized Polyhedron SnO_2 Anode Material for Lithium Ion Battery

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Introduction Tin-based oxides will be promising anode materials for lithium ion batteries due to its high specific capacity, low potential platform, and safety[1]. Many methods have been applied to synthesize SnO2 materials of different morphologies, such as chemical vapor deposition, spray, sol-gel method[2]. Triblock copolymer poly (ethylene oxide)-block-poly (propylene oxide)-block-poly (ethane oxide) (P123) has been used as surfactant to prepare nano-crystalline tin oxide particles[3]. In this pap...

  17. Effects of graphite on Zn-Sb alloys as anode materials for lithium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The electrochemical properties of multiphases Zn4Sb3C7 and ZnSbC2 as new lithium-ion anode materials wereinvestigated. The composition and microstructures of these multiphase materials were analyzed by XRD and TEM. It wasfound that the addition of graphite modifies the microstructures of pure alloys. The capacities and the cycle stability of theanodes are greatly improved. The reversible capacity of Zn4Sb3C7 reaches as high as 510 mAh/g at the first cycle, andkeeps higher than 300 mAh/g after 10 charge/discharge cycles

  18. Self-sealing of unsealed aluminium anodic oxide films in very different atmospheres

    Directory of Open Access Journals (Sweden)

    González, J. A.

    2003-12-01

    Full Text Available It is widely believed that the corrosion resistance behaviour of bare aluminium in natural environments is superior to that of unsealed anodised aluminium. However, results obtained in the exposure of unsealed anodised aluminium specimens with three different film thicknesses, in 9 atmospheres of Ibero-America with salinity levels between 3.9 and 517 mg.m-2.d-1 chloride, clearly shows the reverse to be true. After a sufficient time, which is shorter the higher the precipitation rate and the environmental relative humidity, a self-sealing process takes place, leading to coatings that surpass the quality standards demanded in industrial practice. Anodic films, sealed and unsealed, are protective coatings whose quality improves with ageing in most natural environments.

    Está muy difundida la idea de que el comportamiento del aluminio es superior al del aluminio anodizado y sin sellar, desde el punto de vista de la resistencia a la corrosión, en los ambientes naturales. Sin embargo, los resultados obtenidos en la exposición de anodizados sin sellar, de tres espesores diferentes, a 9 atmósferas de Iberoamérica, con salinidades comprendidas entre 3,9 y 517 mg.m-2.d-1 de cloruros, muestran, sin lugar a dudas, lo contrario. Con tiempo suficiente, tanto más rápidamente cuanto mayor sean las precipitaciones y la humedad relativa ambiental, tiene lugar un proceso de autosellado que conduce a recubrimientos que superan las normas de calidad exigidas en la práctica industrial. Los anodizados, sellados y sin sellar, son recubrimientos protectores que mejoran su calidad, en la mayoría de los ambientes naturales, con el envejecimiento.

  19. Study on the influences of reduction temperature on nickel-yttria-stabilized zirconia solid oxide fuel cell anode using nickel oxide-film electrode

    Science.gov (United States)

    Jiao, Zhenjun; Ueno, Ai; Suzuki, Yuji; Shikazono, Naoki

    2016-10-01

    In this study, the reduction processes of nickel oxide at different temperatures were investigated using nickel-film anode to study the influences of reduction temperature on the initial performances and stability of nickel-yttria-stabilized zirconia anode. Compared to conventional nickel-yttria-stabilized zirconia composite cermet anode, nickel-film anode has the advantage of direct observation at nickel-yttria-stabilized zirconia interface. The microstructural changes were characterized by scanning electron microscopy. The reduction process of nickel oxide is considered to be determined by the competition between the mechanisms of volume reduction in nickel oxide-nickel reaction and nickel sintering. Electrochemical impedance spectroscopy was applied to analyze the time variation of the nickel-film anode electrochemical characteristics. The anode performances and microstructural changes before and after 100 hours discharging and open circuit operations were analyzed. The degradation of nickel-film anode is considered to be determined by the co-effect between the nickel sintering and the change of nickel-yttria-stabilized zirconia interface bonding condition.

  20. Effects of Alloying Element Ca on the Corrosion Behavior and Bioactivity of Anodic Films Formed on AM60 Mg Alloys

    Directory of Open Access Journals (Sweden)

    Anawati Anawati

    2016-12-01

    Full Text Available Effects of alloying element Ca on the corrosion behavior and bioactivity of films formed by plasma electrolytic oxidation (PEO on AM60 alloys were investigated. The corrosion behavior was studied by conducting electrochemical tests in 0.9% NaCl solution while the bioactivity was evaluated by soaking the specimens in simulated body fluid (SBF. Under identical anodization conditions, the PEO film thicknesses increased with increasing Ca content in the alloys, which enhanced the corrosion resistance in NaCl solution. Thicker apatite layers grew on the PEO films of Ca-containing alloys because Ca was incorporated into the PEO film and because Ca was present in the alloys. Improvement of corrosion resistance and bioactivity of the PEO-coated AM60 by alloying with Ca may be beneficial for biodegradable implant applications.

  1. Raney-platinum film electrodes for potentially implantable glucose fuel cells. Part 1: Nickel-free glucose oxidation anodes

    Energy Technology Data Exchange (ETDEWEB)

    Kerzenmacher, S.; von Stetten, F. [Laboratory for MEMS Applications, Department of Microsystems Engineering- IMTEK, University of Freiburg, Georges-Koehler-Allee 106, 79110 Freiburg (Germany); Schroeder, M. [Institut fuer Anorganische und Analytische Chemie, University of Freiburg, Albertstrasse 21, 79104 Freiburg (Germany); Braemer, R. [Hochschule Offenburg- University of Applied Sciences, Badstrasse 24, 79652 Offenburg (Germany); Zengerle, R. [Laboratory for MEMS Applications, Department of Microsystems Engineering- IMTEK, University of Freiburg, Georges-Koehler-Allee 106, 79110 Freiburg (Germany); Centre for Biological Signalling Studies (bioss), Albert-Ludwigs-Universitaet Freiburg (Germany)

    2010-10-01

    We present a novel fabrication route yielding Raney-platinum film electrodes intended as glucose oxidation anodes for potentially implantable fuel cells. Fabrication roots on thermal alloying of an extractable metal with bulk platinum at 200 C for 48 h. In contrast to earlier works using carcinogenic nickel, we employ zinc as potentially biocompatible alloying partner. Microstructure analysis indicates that after removal of extractable zinc the porous Raney-platinum film (roughness factor {proportional_to}2700) consists predominantly of the Pt{sub 3}Zn phase. Release of zinc during electrode operation can be expected to have no significant effect on physiological normal levels in blood and serum, which promises good biocompatibility. In contrast to previous anodes based on hydrogel-bound catalyst particles the novel anodes exhibit excellent resistance against hydrolytic and oxidative attack. Furthermore, they exhibit significantly lower polarization with up to approximately 100 mV more negative electrode potentials in the current density range relevant for fuel cell operation. The anodes' amenability to surface modification with protective polymers is demonstrated by the exemplary application of an approximately 300 nm thin Nafion coating. This had only a marginal effect on the anode long-term stability and amino acid tolerance. While in physiological glucose solution after approximately 100 h of operation gradually increasing performance degradation occurs, rapid electrode polarization within 24 h is observed in artificial tissue fluid. Optimization approaches may include catalyst enhancement by adatom surface modification and the application of specifically designed protective polymers with controlled charge and mesh size. (author)

  2. Monodisperse porous silicon spheres as anode materials for lithium ion batteries.

    Science.gov (United States)

    Wang, Wei; Favors, Zachary; Ionescu, Robert; Ye, Rachel; Bay, Hamed Hosseini; Ozkan, Mihrimah; Ozkan, Cengiz S

    2015-03-05

    Highly monodisperse porous silicon nanospheres (MPSSs) are synthesized via a simple and scalable hydrolysis process with subsequent surface-protected magnesiothermic reduction. The spherical nature of the MPSSs allows for a homogenous stress-strain distribution within the structure during lithiation and delithiation, which dramatically improves the electrochemical stability. To fully extract the real performance of the MPSSs, carbon nanotubes (CNTs) were added to enhance the electronic conductivity within the composite electrode structure, which has been verified to be an effective way to improve the rate and cycling performance of anodes based on nano-Si. The Li-ion battery (LIB) anodes based on MPSSs demonstrate a high reversible capacity of 3105 mAh g(-1). In particular, reversible Li storage capacities above 1500 mAh g(-1) were maintained after 500 cycles at a high rate of C/2. We believe this innovative approach for synthesizing porous Si-based LIB anode materials by using surface-protected magnesiothermic reduction can be readily applied to other types of SiOx nano/microstructures.

  3. A new anode material LiMoS2 for use in rechargeable Lithium Ion Batteries

    Institute of Scientific and Technical Information of China (English)

    YANG Shui-jin; AI Chang-chun; LIANG Yong-guang; SUN Ju-tang

    2004-01-01

    The novel applications of molybdenum disulfide in recent research were reviewed, such as in lubricant, catalyst and photoelectrochemical solar cells. Recently, we found that LiMoS2 is a good candidate for new anode materials for lithium ion batteries with high lithium storage capacity.Here, the anode material LiMoS2 was synthesized by a hydrothermal method at 150℃ and the electrochemical characterization as an anode material for lithium ion batteries was examined.put in Teflon-lined stainless steel autoclaves of capacity 40 mL. Distilled water was used to fill the autoclaves to 70 % of the total volume. The autoclaves were maintained at 150℃ for 24 h and then cooled naturally. The resulting dark-gray powders were filled and washed with distilled water,diluted hydrochloric acid and ethanol, successively. The final products were dried at 80℃ for 24 h.The powder X-ray diffraction pattern showed the prepared LiMoS2 was amorphous structure. A test cell using LiMoS2 as the active material was discharged and charged between 3 and 0.01 V with respect to Li metal at a constant current density of C/5 (that is, one lithium per formula unit in 5 hours). During the first discharge, the potential rapidly drops to reach a large plateau at 2.2 V, then slowly drops to the other plateau at 0.8 V, and then continuously decreases down to 0.01V. There is only a plateau at 1.35 V in the subsequent discharge curves. The plateaus of charge potential appear at about 1.9 V.The irreversible loss was 41% in the first cycle. The ratio of discharge and charge is more than 99%in the subsequent cycles. Moreover, the ratio of discharge and charge almost reaches 100% after thedemonstrated that LiMoS2 has a very high capacity and a good cycle-ability as an anode material forlithium ion batteries.

  4. Graphene encapsulated and SiC reinforced silicon nanowires as an anode material for lithium ion batteries.

    Science.gov (United States)

    Yang, Yang; Ren, Jian-Guo; Wang, Xin; Chui, Ying-San; Wu, Qi-Hui; Chen, Xianfeng; Zhang, Wenjun

    2013-09-21

    Anode materials play a key role in the performance, in particular the capacity and lifetime, of lithium ion batteries (LIBs). Silicon has been demonstrated to be a promising anode material due to its high specific capacity, but pulverization during cycling and formation of an unstable solid-electrolyte interphase limit its cycle life. Herein, we show that anodes consisting of an active silicon nanowire (Si NW), which is surrounded by a uniform graphene shell and comprises silicon carbide nanocrystals, are capable of serving over 500 cycles in half cells at a high lithium storage capacity of 1650 mA h g(-1). In the anodes, the graphene shell provides a highly-conductive path and prevents direct exposure of Si NWs to electrolytes while the SiC nanocrystals may act as a rigid backbone to retain the integrity of the Si NW in its great deformation process caused by repetitive charging-discharging reactions, resulting in a stable cyclability.

  5. Chitosan films and blends for packaging material.

    Science.gov (United States)

    van den Broek, Lambertus A M; Knoop, Rutger J I; Kappen, Frans H J; Boeriu, Carmen G

    2015-02-13

    An increased interest for hygiene in everyday life as well as in food, feed and medical issues lead to a strong interest in films and blends to prevent the growth and accumulation of harmful bacteria. A growing trend is to use synthetic and natural antimicrobial polymers, to provide non-migratory and non-depleting protection agents for application in films, coatings and packaging. In food packaging, antimicrobial effects add up to the barrier properties of the materials, to increase the shelf life and product quality. Chitosan is a natural bioactive polysaccharide with intrinsic antimicrobial activity and, due to its exceptional physicochemical properties imparted by the polysaccharide backbone, has been recognized as a natural alternative to chemically synthesized antimicrobial polymers. This, associated with the increasing preference for biofunctional materials from renewable resources, resulted in a significant interest on the potential for application of chitosan in packaging materials. In this review we describe the latest developments of chitosan films and blends as packaging material. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Dynamic Characterization of Thin Film Magnetic Materials

    Science.gov (United States)

    Gu, Wei

    A broadband dynamic method for characterizing thin film magnetic material is presented. The method is designed to extract the permeability and linewidth of thin magnetic films from measuring the reflection coefficient (S11) of a house-made and short-circuited strip line testing fixture with or without samples loaded. An adaptive de-embedding method is applied to remove the parasitic noise of the housing. The measurements were carried out with frequency up to 10GHz and biasing magnetic fields up to 600 Gauss. Particular measurement setup and 3-step experimental procedures are described in detail. The complex permeability of a 330nm thick continuous FeGaB, 435nm thick laminated FeGaB film and a 100nm thick NiFe film will be induced dynamically in frequency-biasing magnetic field spectra and compared with a theoretical model based on Landau-Lifshitz-Gilbert (LLG) equations and eddy current theories. The ferromagnetic resonance (FMR) phenomenon can be observed among these three magnetic materials investigated in this thesis.

  7. An Sn-Fe/carbon nanocomposite as an alternative anode material for rechargeable lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Sukeun; Lee, Jae-Myung [Department of Materials Science and Engineering, Research Center for Energy Conversion and Storage, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Hansu; Im, Dongmin; Doo, Seok-Gwang [Materials Laboratory, Samsung Advanced Institute of Technology, Yongin-si, Gyeounggi-do 449-712 (Korea, Republic of); Sohn, Hun-Joon [Department of Materials Science and Engineering, Research Center for Energy Conversion and Storage, Seoul National University, Seoul 151-742 (Korea, Republic of)], E-mail: hjsohn@snu.ac.kr

    2009-04-01

    Sn-Fe/carbon nanocomposites were synthesized by the mechanochemical treatment of Sn with various amounts of an Fe/C composite through the pyrolysis of Fe(III) acetylacetonate. The composites were then evaluated as alternative anode materials for rechargeable lithium batteries. Based on the obtained ex situ X-ray diffraction (XRD) data, X-ray absorption spectroscopy (XAS) results, and differential capacity plots (DCPs), a reaction mechanism was suggested. It was found that increasing the amounts of the SnFe phase and pyrolyzed carbon in the composite improved its electrochemical characteristics in terms of its capacity retention.

  8. Electrochemical performance of graphene nanosheets as anode material for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Peng; Song, Huaihe; Chen, Xiaohong [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 100029 Beijing (China)

    2009-06-15

    Graphene nanosheets (GNSs) were prepared from artificial graphite by oxidation, rapid expansion and ultrasonic treatment. The morphology, structure and electrochemical performance of GNSs as anode material for lithium-ion batteries were systematically investigated by high-resolution transmission electron microscope, scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy and a variety of electrochemical testing techniques. It was found that GNSs exhibited a relatively high reversible capacity of 672 mA h/g and fine cycle performance. The exchange current density of GNSs increased with the growth of cycle numbers exhibiting the peculiar electrochemical performance. (author)

  9. Production of lithium positive ions from LiF thin films on the anode in PBFA II

    Energy Technology Data Exchange (ETDEWEB)

    Green, T.A.; Stinnett, R.W.; Gerber, R.A. [and others

    1995-09-01

    The production of positive lithium ions using a lithium-fluoride-coated stainless steel anode in the particle beam fusion accelerator PBFA II is considered from both the experimental and theoretical points of view. It is concluded that the mechanism of Li{sup +} ion production is electric field desorption from the tenth-micron-scale crystallites which compose the columnar growth of the LiF thin film. The required electric field is estimated to be of the order of 5 MV/cm. An essential feature of the mechanism is that the crystallites are rendered electronically conducting through electron-hole pair generation by MeV electron bombardment of the thin film during the operation of the diode. It is proposed that the ion emission mechanism is an electronic conductivity analogue to that discovered by Rollgen for lithium halide crystallites which were rendered ionically conducting by heating to several hundred degrees Celsius. Since an electric field desorption mechanism cannot operate if a surface flashover plasma has formed and reduced the anode electric field to low values, the possibility of flashover on the lithium fluoride coated anode of the PBFA II Li{sup +} ion source is studied theoretically. It is concluded with near certainty that flashover does not occur.

  10. Influence of molybdate species on the tartaric acid/sulphuric acid anodic films grown on AA2024 T3 aerospace alloy

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Rubio, M. [Departamento de Quimica-Fisica Aplicada, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Department of Surface Technologies, Engineering of Materials and Processes, Airbus Spain, Av. John Lennon s/n 28906 Getafe (Spain); Ocon, P. [Departamento de Quimica-Fisica Aplicada, Universidad Autonoma de Madrid, 28049 Madrid (Spain)], E-mail: pilar.ocon@uam.es; Climent-Font, A. [Departamento de Fisica Aplicada, Universidad Autonoma de Madrid (UAM), 28049 Madrid (Spain); Centro de Micro-Analisis de Materiales (CMAM), Universidad Autonoma de Madrid (UAM), 28049 Madrid (Spain); Smith, R.W. [Unidad de Microanalisis de Materiales, Parque Cientifico de Madrid (PCM), Campus de Cantoblanco, 28049 Madrid (Spain); Curioni, M.; Thompson, G.E.; Skeldon, P. [Corrosion and Protection Centre, School of Materials, University of Manchester, M60 1QD England (United Kingdom); Lavia, A.; Garcia, I. [Department of Surface Technologies, Engineering of Materials and Processes, Airbus Spain, Av. John Lennon s/n 28906 Getafe (Spain)

    2009-09-15

    AA2024 T3 alloy specimens have been anodised in tartaric acid/sulphuric media and tartaric acid/sulphuric media containing sodium molybdate; molybdate species were added to the anodising bath to enhance further the protection provided by the porous anodic film developed over the macroscopic alloy surface. Morphological characterisation of the anodic films formed in both electrolytes was undertaken using scanning electron and transmission electron microscopies; the chemical compositions of the films were determined by Rutherford backscattering spectroscopy that was complemented by elemental depth profiling using rf-glow discharge optical emission spectrometry. The electrochemical behaviour was evaluated using potentiodynamic polarisations and electrochemical impedance spectroscopy; the corrosion performance was examined after salt spray testing. The porous anodic film morphology was little influenced by the addition of molybdate salt, although thinner films were generated in its presence. Chemical composition of the anodic film was roughly similar; however, addition of sodium molybdate in the anodizing bath resulted in residues of molybdate species in the porous skeleton and improved corrosion resistance measured by electrochemical techniques that was confirmed by salt spray testing.

  11. Mesoporous Titania Microspheres with Highly Tunable Pores as an Anode Material for Lithium Ion Batteries.

    Science.gov (United States)

    Fischer, Michael G; Hua, Xiao; Wilts, Bodo D; Gunkel, Ilja; Bennett, Thomas M; Steiner, Ullrich

    2017-07-12

    Mesoporous titania microspheres (MTMs) have been employed in many applications, including (photo)catalysis as well as energy conversion and storage. Their morphology offers a hierarchical structural design motif that lends itself to being incorporated into established large-scale fabrication processes. Despite the fact that device performance hinges on the precise morphological characteristics of these materials, control over the detailed mesopore structure and the tunability of the pore size remains a challenge. Especially the accessibility of a wide range of mesopore sizes by the same synthesis method is desirable, as this would allow for a comparative study of the relationship between structural features and performance. Here, we report a method that combines sol-gel chemistry with polymer micro- and macrophase separation to synthesize porous titania spheres with diameters in the micrometer range. The as-prepared MTMs exhibit well-defined, accessible porosities with mesopore sizes adjustable by the choice of the polymers. When applied as an anode material in lithium ion batteries (LIBs), the MTMs demonstrate excellent performance. The influence of the pore size and an in situ carbon coating on charge transport and storage is examined, providing important insights for the optimization of structured titania anodes in LIBs. Our synthesis strategy presents a facile one-pot approach that can be applied to different structure-directing agents and inorganic materials, thus further extending its scope of application.

  12. Li Metal Anodes and Rechargeable Lithium Metal Batteries. Springer Series in Materials Science

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiguang; Xu, Wu; Henderson, Wesley A.

    2017-01-03

    Lithium (Li) metal is an ideal anode material for rechargeable batteries. With the urgent need for the “next generation” rechargeable batteries, such as Li-S, Li-air batteries as well as rechargeable Li metal batteries using Li intercalation compounds as the cathode, the use of Li metal anode has attracted significant interests in recent years. Unfortunately, rechargeable batteries based on Li metal anode have not yet been commercialized mainly due to two barriers: one is the growth of Li dendrites and associated safety hazard, and another is the low Coulombic efficiency (CE) of Li cycling and associated early battery failure due to Li powdering and increasing cell impedance. To have a high CE, minimum side reactions between freshly/native deposited Li and electrolyte has to be minimized. These reactions are proportional to the chemical and electrochemical activity of native Li when they are in direct contact with surrounding electrolyte. They are also proportional to the surface area of deposited Li. This means that high CE of Li deposition/stripping always related to a low surface area Li deposition and suppressed Li dendrite growth. Therefore, the enhancement of CE is a more fundamental factors controlling long term, stable cycling of Li metal anode. In this book, we will first review the general models of the dendrite growth mechanism. The effect of SEI layer on the modeling of Li dendrite growth will also be discussed. Then we will discuss various instruments/tools that are critical for the investigation of Li dendrite growth. In the Chapter 3, various factors which affect CE of Li cycling and dendrite growth will be discussed together with an emphasize on enhancement of CE. Chapter 4 of the book will discuss the specific application of Li metal anode in several key rechargeable Li metal batteries, including Li-air batteries, Li-S batteries and Li metal batteries using intercalation compounds as cathode. At last, the perspective on the future development

  13. Lithium Ion Battery Anode Aging Mechanisms

    Directory of Open Access Journals (Sweden)

    Victor Agubra

    2013-03-01

    Full Text Available Degradation mechanisms such as lithium plating, growth of the passivated surface film layer on the electrodes and loss of both recyclable lithium ions and electrode material adversely affect the longevity of the lithium ion battery. The anode electrode is very vulnerable to these degradation mechanisms. In this paper, the most common aging mechanisms occurring at the anode during the operation of the lithium battery, as well as some approaches for minimizing the degradation are reviewed.

  14. Lithium Ion Battery Anode Aging Mechanisms

    OpenAIRE

    Victor Agubra; Jeffrey Fergus

    2013-01-01

    Degradation mechanisms such as lithium plating, growth of the passivated surface film layer on the electrodes and loss of both recyclable lithium ions and electrode material adversely affect the longevity of the lithium ion battery. The anode electrode is very vulnerable to these degradation mechanisms. In this paper, the most common aging mechanisms occurring at the anode during the operation of the lithium battery, as well as some approaches for minimizing the degradation are reviewed.

  15. Surface-modified graphite for improving electrochemical performance of Li-ion battery anode material

    Institute of Scientific and Technical Information of China (English)

    CHEN Jin-ming; WANG Fu-tian; LIU Mao-huang

    2004-01-01

    The graphite materials have been used as negative electrodes in commercial Li-ion batteries for many years. In order to avoid the exfoliation of graphite sheet in the PC-based electrolyte system, it is necessary to make the surface modification on the graphite material. In this study, the electrochemical behavior of carbon-coated graphite in PC-based electrolyte was investigated by charge and discharge cycling process. The carbon-coated graphite can increase the reversible from 366 mA/g to 399mAh/g and improve cycle ability in the PC-based electrolyte system. So the carbon-coated graphite can become the promising high-capacity anode materials of Li-ion battery.

  16. High quality 2D crystals made by anodic bonding: a general technique for layered materials.

    Science.gov (United States)

    Gacem, Karim; Boukhicha, Mohamed; Chen, Zhesheng; Shukla, Abhay

    2012-12-21

    Anodic bonding of nanolayers is an easy technique based on a simple apparatus, which has already proven successful in application in the fabrication of high quality graphene. Here we demonstrate its extension to the fabrication of high quality nanolayers from several layered materials. The strengths of this technique are its high throughput rate and ease of application. All fabrication parameters are controllable and need to be determined carefully. We report optimal parameters found for nine layered materials. In general, using optimal parameters results in high quality 2D layers, in most cases much larger than those obtained by 'Scotch tape' microcleavage, with higher yields and which are easily transferable to other substrates. Moreover the samples obtained are clean and the good optical contrast of these layers on the glass substrate makes their identification very easy. This is thus the technique of choice for making nanolayers in the laboratory from any layered material.

  17. High quality 2D crystals made by anodic bonding: a general technique for layered materials

    Science.gov (United States)

    Gacem, Karim; Boukhicha, Mohamed; Chen, Zhesheng; Shukla, Abhay

    2012-12-01

    Anodic bonding of nanolayers is an easy technique based on a simple apparatus, which has already proven successful in application in the fabrication of high quality graphene. Here we demonstrate its extension to the fabrication of high quality nanolayers from several layered materials. The strengths of this technique are its high throughput rate and ease of application. All fabrication parameters are controllable and need to be determined carefully. We report optimal parameters found for nine layered materials. In general, using optimal parameters results in high quality 2D layers, in most cases much larger than those obtained by ‘Scotch tape’ microcleavage, with higher yields and which are easily transferable to other substrates. Moreover the samples obtained are clean and the good optical contrast of these layers on the glass substrate makes their identification very easy. This is thus the technique of choice for making nanolayers in the laboratory from any layered material.

  18. SYNTHESIS OF NANO-ZnO PARTICLES FOR ALUMINUM METALLURGY AS INERT ANODE MATERIAL

    Institute of Scientific and Technical Information of China (English)

    A.A.A. Saleh; Y. Fu; X.J. Zhai; Y.C. Zhai; M.M. Elomella; A.L. Zhang

    2004-01-01

    Nano-ZnO particle was produced by evaporating zinc powders in air at air flow-rate from 0.2 to 0.6m3/h. Nano-ZnO particles was formed by the oxidation of the evaporated zinc vapor. X-ray diffraction shows the powders to be ZnO with lattice parameters of a=0.3249nm and c=0.5205nm. The particle size is dependent upon the transit time from the source to the collection area. The size of particles was ranged between 81 to 103nm. The average density resulted was 4.865g/cm3.Normal ZnO and nano-ZnO were investigated to use them in aluminum metallurgy as an inert anode material. A certain amount of both oxides were molded subsequently inserted to the molten cryolite-aluminum oxide to investigate the corrosive behavior of both oxides. When the sintering temperature increased up to 1300 ℃, the weight loss ratio rose to 5.01%-7.33% and up to 7.67%-10.18% for nano-ZnO and normal ZnO, respectively. However, when the samples in the molten cryolite aluminum oxide were put for long time, the corrosive rate was found to be higher. It was found that the corrosive loss weight ratio of nano-ZnO anode was much lower than the normal one made from ordinary-ZnO providing that the nano-ZnO is more possible to be use inert anode material.

  19. Synthesis and characterization of cathode, anode and electrolyte materials for rechargeable lithium batteries

    Science.gov (United States)

    Yang, Shoufeng

    Two new classes of cathode materials were studied: iron phosphate/sulfate materials and layered manganese oxides, both of which are low cost and had shown some potential. The first class of materials have poor conductivity and cyclability. I studied a number of methods for increasing the conductivity, and determined that grinding the material with carbon black was as effective as special in-situ coatings. The optimum carbon loading was determined to be between 6 and 15 wt%. Too much carbon reduces the volumetric energy density, whereas too little significantly increased cell polarization (reduced the rate of reaction). The kinetic and thermodynamic stability of LiFePO 4 was also studied and it was determined that over discharge protection will be needed as irreversible Li3PO4 can be formed at low potentials. A novel hydrothermal synthesis method was developed, but the significant level of Fe on the Li site reduces the reaction rate too much. In the case of the layered manganese oxide, cation substitution with Co and Ni is found to be effective in avoiding Jahn-Teller effects and improving electrochemistry. A wide range of tin compounds have been suggested as lithium storage media for advanced anode materials, as tin can store over 4 Li per Sn atom. Lithium hexafluorophosphate, LiPF6, is presently the salt of choice for LiCoO2 batteries, but it is expensive and dissolves some manganese compounds. The lithium bis(oxolato)borate (BOB) salt was recently reported, and I made a study of its use in cells with the LiFePO4 cathode and the tin anode. During its synthesis, it became clear that LiBOB is very reactive with many solvents, and these complexes were characterized to better understand this new material. In LiBOB the lithium is five coordinated, an unstable configuration for the lithium ion so that water and many other solvents rapidly react to make a six coordination. Only in the case of ethylene carbonate was the lithium found to be four coordinated. The Li

  20. Synthesis, characterization and performance of robust poison-resistant ultrathin film yttria stabilized zirconia - nickel anodes for application in solid electrolyte fuel cells

    Science.gov (United States)

    Garcia-Garcia, F. J.; Yubero, F.; Espinós, J. P.; González-Elipe, A. R.; Lambert, R. M.

    2016-08-01

    We report on the synthesis of undoped ∼5 μm YSZ-Ni porous thin films prepared by reactive pulsed DC magnetron sputtering at an oblique angle of incidence. Pre-calcination of the amorphous unmodified precursor layers followed by reduction produces a film consisting of uniformly distributed tilted columnar aggregates having extensive three-phase boundaries and favorable gas diffusion characteristics. Similarly prepared films doped with 1.2 at.% Au are also porous and contain highly dispersed gold present as Ni-Au alloy particles whose surfaces are strongly enriched with Au. With hydrogen as fuel, the performance of the undoped thin film anodes is comparable to that of 10-20 times thicker typical commercial anodes. With a 1:1 steam/carbon feed, the un-doped anode cell current rapidly falls to zero after 60 h. In striking contrast, the initial performance of the Au-doped anode is much higher and remains unaffected after 170 h. Under deliberately harsh conditions the performance of the Au-doped anodes decreases progressively, almost certainly due to carbon deposition. Even so, the cell maintains some activity after 3 days operation in dramatic contrast with the un-doped anode, which stops working after only three hours of use. The implications and possible practical application of these findings are discussed.

  1. Fabrication of LSGM thin films on porous anode supports by slurry spin coating for IT-SOFC

    Institute of Scientific and Technical Information of China (English)

    Hong-Yan Sun; Wei Sen; Wen-Hui Ma; Jie Yu; Jian-Jun Yang

    2015-01-01

    La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) and La0.7 Sr0.3Cr0.5Mn0.5O3-δ (LSCM) powders were synthesized by glycine-nitrate process,and LSGM electrolyte thin film was successfully fabricated on porous anode substrate of LSCM by slurry spin coating technology.Some technical parameters for the preparation of LSGM thin films were systematically investigated,including ink composition,sintering temperature,and spin coating times.The electrolyte films with the best compactness and somewhat rough are obtained when the operating parameters are fixed as follows:the content of ethyl cellulose as binder is 5 wt%,the content of terpineol as modifier is 5 wt%,the optimum coating cycle number is 9 times,and the best post-deposition sintering temperature is 1,400 ℃ for 4 h.

  2. Changes in the morphology of porous anodic films formed on aluminium in natural and artificial ageing

    Directory of Open Access Journals (Sweden)

    López, V.

    2003-12-01

    Full Text Available Transmission electron microscopy and electrochemical impedance spectroscopy are used to demonstrate that the water retained in porous anodic aluminium oxide films is the main reason for their reactivity under electron beam irradiation in the TEM, accelerated ageing in an oven at 100 °C, or natural ageing over months and years in an outdoor atmosphere. Though the kinetics in each medium is highly different, there is a clear similarity between the structural and physical-chemical transformations that take place. Unsealed layers, practically free of water, hardly change their structure under the effect of electron beams and show the same impedance plots after hours at 100 °C or after years at environmental temperature in dry atmospheres.

    La microscopía electrónica de transmisión, por una parte, y la espectroscopia de impedancia electroquímica, por otra, demuestran que el agua retenida en las películas anódicas porosas de óxido de aluminio es la principal responsable de su reactividad bajo la irradiación del haz de electrones en el MET, en el envejecimiento acelerado en la estufa a 100 ºC o en el envejecimiento natural de meses y años en la atmósfera a temperatura ambiente. Aunque, de cinéticas muy diferentes, existe una indudable semejanza entre las transformaciones estructurales y físico-químicas que tienen lugar en los tres medios. Las capas sin sellar, prácticamente exentas de agua, apenas cambian su estructura por efecto del haz de electrones y muestran los mismos diagramas de impedancia después de horas a 100 ºC o de años a temperatura ambiente en atmósferas secas.

  3. Gas permeability measurements for film envelope materials

    Energy Technology Data Exchange (ETDEWEB)

    Ludtka, Gerard M. (Oak Ridge, TN); Kollie, Thomas G. (Oak Ridge, TN); Watkin, David C. (Clinton, TN); Walton, David G. (Knoxville, TN)

    1998-01-01

    Method and apparatus for measuring the permeability of polymer film materials such as used in super-insulation powder-filled evacuated panels (PEPs) reduce the time required for testing from several years to weeks or months. The method involves substitution of a solid non-outgassing body having a free volume of between 0% and 25% of its total volume for the usual powder in the PEP to control the free volume of the "body-filled panel". Pressure versus time data for the test piece permit extrapolation to obtain long term performance of the candidate materials.

  4. Gas permeability measurements for film envelope materials

    Energy Technology Data Exchange (ETDEWEB)

    Ludtka, G.M.; Kollie, T.G.; Watkin, D.C.; Walton, D.G.

    1998-05-12

    Method and apparatus for measuring the permeability of polymer film materials such as used in super-insulation powder-filled evacuated panels (PEPs) reduce the time required for testing from several years to weeks or months. The method involves substitution of a solid non-outgassing body having a free volume of between 0% and 25% of its total volume for the usual powder in the PEP to control the free volume of the ``body-filled panel.`` Pressure versus time data for the test piece permit extrapolation to obtain long term performance of the candidate materials. 4 figs.

  5. Zinc naphthalenedicarboxylate coordination complex: A promising anode material for lithium and sodium-ion batteries with good cycling stability.

    Science.gov (United States)

    Fei, Hailong; Feng, Wenjing; Xu, Tan

    2017-02-15

    It is important to discover new, cheap and environmental friendly electrode materials with high capacity and good cycling stability for lithium and sodium-ion batteries. Zinc 1,4-naphthalenedicarboxylate was firstly found to be stable anode materials for lithium and sodium-ion batteries. The discharge capacity can be up to 468.9mAhg(-1) after 100 cycles at a current density of 100mAg(-1) for lithium-ion batteries, while the second discharge capacity of 320.7mAhg(-1) was achieved as anode materials for sodium-ion batteries. A possible electrochemical reaction mechanism was discussed.

  6. Heat-treated stainless steel felt as scalable anode material for bioelectrochemical systems.

    Science.gov (United States)

    Guo, Kun; Soeriyadi, Alexander H; Feng, Huajun; Prévoteau, Antonin; Patil, Sunil A; Gooding, J Justin; Rabaey, Korneel

    2015-11-01

    This work reports a simple and scalable method to convert stainless steel (SS) felt into an effective anode for bioelectrochemical systems (BESs) by means of heat treatment. X-ray photoelectron spectroscopy and cyclic voltammetry elucidated that the heat treatment generated an iron oxide rich layer on the SS felt surface. The iron oxide layer dramatically enhanced the electroactive biofilm formation on SS felt surface in BESs. Consequently, the sustained current densities achieved on the treated electrodes (1 cm(2)) were around 1.5±0.13 mA/cm(2), which was seven times higher than the untreated electrodes (0.22±0.04 mA/cm(2)). To test the scalability of this material, the heat-treated SS felt was scaled up to 150 cm(2) and similar current density (1.5 mA/cm(2)) was achieved on the larger electrode. The low cost, straightforwardness of the treatment, high conductivity and high bioelectrocatalytic performance make heat-treated SS felt a scalable anodic material for BESs.

  7. Sodium-intercalated bulk graphdiyne as an anode material for rechargeable batteries

    Science.gov (United States)

    Farokh Niaei, Amir H.; Hussain, Tanveer; Hankel, Marlies; Searles, Debra J.

    2017-03-01

    We present the results of a density functional theory study of sodium storage and mobility on graphdiyne (GDY) and consider the applicability of GDY intercalated with sodium (Na) as an anode material for rechargeable batteries. The maximum capacity, energy barriers for Na diffusion throughout the layers, and expansion of the layers due to Na insertion are determined. The calculations indicate that Na intercalates within the GDY bulk layers with a capacity of NaC5.14 without expansion (316 mA h g-1) and NaC2.57 with expansion of 28% (497 mA h g-1). The energy barrier for movement of Na in the slit pore formed by two GDY bulk layers is found to be 0.82 eV for bulk GDY with an AB-2 stacking, and the barrier for movement through a GDY sheet is found to be 0.12 eV. The barrier for movement in the slit pore formed by sheets becomes even lower for AB-3 stacking, with values of 0.68 and 0.40 eV found for different pathways. Movement from one GDY sheet to another for the AB-3 stacking also has a moderate energy of 0.37 eV. Therefore, GDY intercalated with Na is proposed to have potential as an anode material for rechargeable batteries.

  8. Polycrystalline thin film materials and devices

    Energy Technology Data Exchange (ETDEWEB)

    Baron, B.N.; Birkmire, R.W.; Phillips, J.E.; Shafarman, W.N.; Hegedus, S.S.; McCandless, B.E. (Delaware Univ., Newark, DE (United States). Inst. of Energy Conversion)

    1992-10-01

    Results of Phase II of a research program on polycrystalline thin film heterojunction solar cells are presented. Relations between processing, materials properties and device performance were studied. The analysis of these solar cells explains how minority carrier recombination at the interface and at grain boundaries can be reduced by doping of windows and absorber layers, such as in high efficiency CdTe and CuInSe{sub 2} based solar cells. The additional geometric dimension introduced by the polycrystallinity must be taken into consideration. The solar cells are limited by the diode current, caused by recombination in the space charge region. J-V characteristics of CuInSe{sub 2}/(CdZn)S cells were analyzed. Current-voltage and spectral response measurements were also made on high efficiency CdTe/CdS thin film solar cells prepared by vacuum evaporation. Cu-In bilayers were reacted with Se and H{sub 2}Se gas to form CuInSe{sub 2} films; the reaction pathways and the precursor were studied. Several approaches to fabrication of these thin film solar cells in a superstrate configuration were explored. A self-consistent picture of the effects of processing on the evolution of CdTe cells was developed.

  9. Surface characteristics of hydroxyapatite films deposited on anodized titanium by an electrochemical method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang [Research Institute, Kuwotech, 970–88, Wolchul-dong, Buk-ku, Gwangju (Korea, Republic of); Department of Dental Materials and Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Jeong, Yong-Hoon; Brantley, William A. [Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, The Ohio State, University, Columbus, OH (United States); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials and Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University, Gwangju (Korea, Republic of)

    2013-11-01

    The biocompatibility of anodized titanium (Ti) was improved by an electrochemically deposited calcium phosphate (CaP) layer. The CaP layer was grown on the anodized Ti surface in modified simulated body fluid (M-SBF) at 85 °C. The phases and morphologies for the CaP layers were influenced by the electrolyte concentration. Nano flake-like precipitates that formed under low M-SBF concentrations were identified as hydroxyapatite (HAp) crystals orientated in the c-axis direction. In high M-SBF concentrations, the CaP layer formed micro plate-like precipitates on anodized Ti, and micropores were covered with HAp. Proliferation of murine preosteoblast cell (MC3T3-E1) on the HAp/anodized Ti surfaces was significantly higher than for untreated Ti and anodized Ti surfaces. - Highlights: • CaP layers were grown on anodized Ti surfaces by an electrochemical deposition process. • Phases and morphologies of layers were influenced by the electrolyte concentration. • Superior cell proliferation was observed on hydroxyapatite-coated anodized surfaces.

  10. High work function of Al-doped zinc-oxide thin films as transparent conductive anodes in organic light-emitting devices

    Science.gov (United States)

    Kim, T. W.; Choo, D. C.; No, Y. S.; Choi, W. K.; Choi, E. H.

    2006-12-01

    Deposition of Al-doped ZnO (AZO) films with various film thicknesses on glass substrates was performed to investigate the feasibility of using AZO films as anode electrodes in organic light-emitting devices (OLEDs). The electrical resistivity of the AZO films with a 180-nm thickness was 4.085 × 10 -2 Ω cm, and the average optical transmittance in the visible range was 80.2%. The surface work function for the AZO films, determined from the secondary electron emission coefficients obtained with a focused ion beam, was as high as 4.62 eV. These results indicate that AZO films grown on glass substrates hold promise for potential applications as anode electrodes in high-efficiency OLEDs.

  11. Conical tungsten stamps for the replication of pore arrays in anodic aluminium oxide films.

    Science.gov (United States)

    LeClere, D J; Thompson, G E; Derby, B

    2009-06-17

    A tungsten master stamp has been generated by applying a novel procedure that includes two-step anodizing, followed by sequential anodizing and pore widening to develop nominally funnelled pores. These conical-shaped pores were filled with tungsten by sputter coating to manufacture a master stamp. Under a pressure of 65 MPa, the master stamp successfully embossed the surface of annealed and electropolished aluminium. The embossed surface was then used to control the position of pores created by anodizing under the conditions used to produce the original pore array.

  12. Wetting and Photocatalytic Properties of TiO2 Nanotube Arrays Prepared via Anodic Oxidation of E-Beam Evaporated Ti Thin Films

    Directory of Open Access Journals (Sweden)

    Soon Wook Kim

    2015-01-01

    Full Text Available TiO2 nanotube arrays (TNAs are fabricated on quartz substrate by anodizing E-beam evaporated Ti films. E-beam evaporated Ti films are directly anodized at various anodizing voltages ranging from 20 to 45 V and their morphological, wetting, and photocatalytic properties are examined. The photocatalytic activity of the prepared TNAs is evaluated by the photodecomposition of methylene blue under UV illumination. The TNAs prepared at an anodizing voltage of 30 V have a high roughness of 30.1 nm and a low water contact angle of 7.5°, resulting in a high photocatalytic performance. The surface roughness of the TNAs is found to correlate inversely with the water contact angle. High roughness (i.e., high surface area, which leads to high hydrophilicity, is desirable for effective photocatalytic activity.

  13. In situ fabrication of electrochemically grown mesoporous metallic thin films by anodic dissolution in deep eutectic solvents.

    Science.gov (United States)

    Renjith, Anu; Roy, Arun; Lakshminarayanan, V

    2014-07-15

    We describe here a simple electrodeposition process of forming thin films of noble metallic nanoparticles such as Au, Ag and Pd in deep eutectic solvents (DES). The method consists of anodic dissolution of the corresponding metal in DES followed by the deposition on the cathodic surface. The anodic dissolution process in DES overcomes the problems associated with copious hydrogen and oxygen evolution on the electrode surface when carried out in aqueous medium. The proposed method utilizes the inherent abilities of DES to act as a reducing medium while simultaneously stabilizing the nanoparticles that are formed. The mesoporous metal films were characterized by SEM, XRD and electrochemical techniques. Potential applications of these substrates in surface enhanced Raman spectroscopy and electrocatalysis have been investigated. A large enhancement of Raman signal of analyte was achieved on the mesoporous silver substrate after removing all the stabilizer molecules from the surface by calcination. The highly porous texture of the electrodeposited film provides superior electro catalytic performance for hydrogen evolution reaction (HER). The mechanisms of HER on the fabricated substrates were studied by Tafel analysis and electrochemical impedance spectroscopy (EIS). Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Rational Design of Photonic Dust from Nanoporous Anodic Alumina Films: A Versatile Photonic Nanotool for Visual Sensing

    Science.gov (United States)

    Chen, Yuting; Santos, Abel; Wang, Ye; Kumeria, Tushar; Ho, Daena; Li, Junsheng; Wang, Changhai; Losic, Dusan

    2015-08-01

    Herein, we present a systematic study on the development, optimisation and applicability of interferometrically coloured distributed Bragg reflectors based on nanoporous anodic alumina (NAA-DBRs) in the form of films and nanoporous microparticles as visual/colorimetric analytical tools. Firstly, we synthesise a complete palette of NAA-DBRs by galvanostatic pulse anodisation approach, in which the current density is altered in a periodic fashion in order to engineer the effective medium of the resulting photonic films in depth. NAA-DBR photonic films feature vivid colours that can be tuned across the UV-visible-NIR spectrum by structural engineering. Secondly, the effective medium of the resulting photonic films is assessed systematically by visual analysis and reflectometric interference spectroscopy (RIfS) in order to establish the most optimal nanoporous platforms to develop visual/colorimetric tools. Then, we demonstrate the applicability of NAA-DBR photonic films as a chemically selective sensing platform for visual detection of mercury(II) ions. Finally, we generate a new nanomaterial, so-called photonic dust, by breaking down NAA-DBRs films into nanoporous microparticles. The resulting microparticles (μP-NAA-DBRs) display vivid colours and are sensitive towards changes in their effective medium, opening new opportunities for developing advanced photonic nanotools for a broad range of applications.

  15. Structures, phase stabilities, and electrical potentials of Li-Si battery anode materials

    KAUST Repository

    Tipton, William W.

    2013-05-28

    The Li-Si materials system holds promise for use as an anode in Li-ion battery applications. For this system, we determine the charge capacity, voltage profiles, and energy storage density solely by ab initio methods without any experimental input. We determine the energetics of the stable and metastable Li-Si phases likely to form during the charging and discharging of a battery. Ab initio molecular dynamics simulations are used to model the structure of amorphous Li-Si as a function of composition, and a genetic algorithm coupled to density-functional theory searches the Li-Si binary phase diagram for small-cell, metastable crystal structures. Calculations of the phonon densities of states using density-functional perturbation theory for selected structures determine the importance of vibrational, including zero-point, contributions to the free energies. The energetics and local structural motifs of these metastable Li-Si phases closely resemble those of the amorphous phases, making these small unit cell crystal phases good approximants of the amorphous phase for use in further studies. The charge capacity is estimated, and the electrical potential profiles and the energy density of Li-Si anodes are predicted. We find, in good agreement with experimental measurements, that the formation of amorphous Li-Si only slightly increases the anode potential. Additionally, the genetic algorithm identifies a previously unreported member of the Li-Si binary phase diagram with composition Li5Si2 which is stable at 0 K with respect to previously known phases. We discuss its relationship to the partially occupied Li7Si3 phase. © 2013 American Physical Society.

  16. Effects of anode active materials to the storage-capacity fading on commercial lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Gunho; Park, Jounghwan; Lee, Jinuk [Energy Business Division, Samsung SDI Co. Ltd., Sungsung-Dong, Cheonan-Si, Chungcheongnam-Do 330-300 (Korea); Kim, Sinja; Jung, Inho [Corporate R and D Center, Samsung SDI Co. Ltd., Sungsung-Dong, Cheonan-Si, Chungcheongnam-Do 330-300 (Korea)

    2007-12-06

    Thermal storage of prismatic Li-ion cell with different types of anodes has been performed at 60 C for 15 days to 30 days. The results were compared for two anodes: natural-like graphite (NLG) with styrene-butadiene rubber (SBR, 2.5 wt.%) binder and artificial graphite (AG) with polyvinylidene fluoride (PVdF, 6 wt.%) as binder. The storage-capacity fading behavior of the commercial Li-ion cell was studied by dissection the storage cells and analyzing their electrodes and solid electrolyte interphase (SEI), allows lithium-ion transfer but prevents electron migration using SEM, DSC, FT-IR, XRD and impedance analysis. Side-reaction and transformation of the passivation film on NLG anode contributed the capacity loss. Self-discharge of NLG cell due to high specific surface area was one of the main factors for capacity fading. Impedance analysis revealed that the interfacial resistance at NLG anode was larger than that of the AG anode. The increase of lithium alkylcarbonate and lithium carbonate due to reductive decomposition of electrolyte with storage time decreased the charge and increased the interfacial resistance. (author)

  17. Effects of anode active materials to the storage-capacity fading on commercial lithium-ion batteries

    Science.gov (United States)

    Kwak, Gunho; Park, Jounghwan; Lee, Jinuk; Kim, Sinja; Jung, Inho

    Thermal storage of prismatic Li-ion cell with different types of anodes has been performed at 60 °C for 15 days to 30 days. The results were compared for two anodes: natural-like graphite (NLG) with styrene-butadiene rubber (SBR, 2.5 wt.%) binder and artificial graphite (AG) with polyvinylidene fluoride (PVdF, 6 wt.%) as binder. The storage-capacity fading behavior of the commercial Li-ion cell was studied by dissection the storage cells and analyzing their electrodes and solid electrolyte interphase (SEI), allows lithium-ion transfer but prevents electron migration using SEM, DSC, FT-IR, XRD and impedance analysis. Side-reaction and transformation of the passivation film on NLG anode contributed the capacity loss. Self-discharge of NLG cell due to high specific surface area was one of the main factors for capacity fading. Impedance analysis revealed that the interfacial resistance at NLG anode was larger than that of the AG anode. The increase of lithium alkylcarbonate and lithium carbonate due to reductive decomposition of electrolyte with storage time decreased the charge and increased the interfacial resistance.

  18. Preparation and Characterization of Carbon Coated Silicon Nanoparticle as Anode Material for Li-ion Batteries

    Institute of Scientific and Technical Information of China (English)

    T. Zhancg; L.J. Fu; J. Gao; Y. P. Wu; H.Q. Wu

    2005-01-01

    @@ 1Introduction Silicon has been regarded as one of the most promising anode materials for Li-ion batteries. Its theoretical capacity (4 000 mAh/g) is much higher than that of the commercialized graphite (372 mAh/g)[1]. However,the cycle performance of silicon is poor due to the severe volume expansion and shrinkage during Li+ insertion/extraction which results in pulverization of Si particles, eventually losing its Li+ storage ability[2]. To solve this problem, nanosized Si particles were utilized and achieved a partial improvement by reducing the absolute volume change. Nevertheless, a new problem was encountered with nanosized material that small Si particles were aggregated to be larger one during Li+ insertion/extraction, and then pulverized again[3]. In this work, we have succeeded to improve the cycle performance of nanosized Si particles by synthesis of carbon coated silicon nanoparticle.

  19. The New Method of XRD Measurement of the Degree of Disorder for Anode Coke Material

    Directory of Open Access Journals (Sweden)

    Zhuo Zhang

    2017-01-01

    Full Text Available Quantitative analysis by X-ray powder diffraction of two cokes (pitch coke and petroleum coke shows that their crystal structure changed with increasing temperature. The crystal data processing of the crystallization degree of disorder is used with further improvement of the proposed microcrystalline-stacking fault calculation method. With this improvement it is now possible to obtain the degree of stacking disorder of two cokes applied as anode materials at different graphitization temperatures. Raman spectroscopy verified the accuracy of this method, which is more reliable than the crystal structure refinement using the d002 method. This paper provides the theoretical analysis and interpretation of the relationship between the microstructure model of the material and quantitative data, discharge capacity, and the first charge-discharge efficiency.

  20. Microscopic properties of lithium, sodium, and magnesium battery anode materials related to possible dendrite growth

    Energy Technology Data Exchange (ETDEWEB)

    Jäckle, Markus; Groß, Axel [Institute of Theoretical Chemistry, Ulm University, 89069 Ulm, Germany and Helmholtz Institut Ulm (HIU) Electrochemical Energy Storage, 89069 Ulm (Germany)

    2014-11-07

    Lithium and magnesium exhibit rather different properties as battery anode materials with respect to the phenomenon of dendrite formation which can lead to short-circuits in batteries. Diffusion processes are the key to understanding structure forming processes on surfaces. Therefore, we have determined adsorption energies and barriers for the self-diffusion on Li and Mg using periodic density functional theory calculations and contrasted the results to Na which is also regarded as a promising electrode material in batteries. According to our calculations, magnesium exhibits a tendency towards the growth of smooth surfaces as it exhibits lower diffusion barriers than lithium and sodium, and as an hcp metal it favors higher-coordinated configurations in contrast to the bcc metals Li and Na. These characteristic differences are expected to contribute to the unequal tendencies of these metals with respect to dendrite growth.

  1. Electrochemical properties of some cobalt antimonides as anode materials for lithium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xinbing; CAO Gaoshao; ZHANG Lijuan; XIE Jian

    2003-01-01

    Some cobalt antimonides have been prepared and studied as the candidate anode materials for lithium ion batteries. Reversible capacities of 424, 423 and 546 mA@h@g -1 were measured at the first cycle for as-solidified CoSb2, CoSb3 and annealed CoSb3 respectively. A low lithium ions diffusion coefficient in the order of 10-16 m 2@s -1 was estimated from the coulometric titration measurements in the annealed CoSb3 electrode. It was found that the electrochemical properties of fine powders are significantly better than coarse powders. However the SEM picture shows that the nano-sized CoSb3powders gathered to larger granules, which worsens somewhat the capacity retention of the nano-sized materials, although the volume capacities of the annealed and ball milled CoSb3 remain near twice of that of graphite after 50 cycles.

  2. Purity of silicon: with great effect on its performance in graphite-silicon anode materials for lithium-ion batteries

    Science.gov (United States)

    Jin, Chenxin; Xu, Guojun; Liu, Liekai; Yue, Zhihao; Li, Xiaomin; Sun, Fugen; Tang, Hao; Huang, Haibin; Zhou, Lang

    2017-09-01

    Ferrosilicon, industrial grade silicon, solar grade silicon, and electronic grade silicon were ball-milled to form four types of silicon powders, which were mixed with graphite powders at weight ratio of 5:95, respectively, for being used as graphite-silicon anode materials in lithium-ion batteries (LIBs). The effect of the purity of silicon on its electrochemical performance in graphite-silicon anode materials for LIBs was investigated by the cycle and rate tests. Results show that silicon with higher purity shows higher capacity, better cycle, and rate performance. In addition, the significant difference in capacity of the four graphite-silicon anodes with different purities of silicon is not completely resulted from the content of silicon materials, and the influence of the impurity inside the silicon cannot be ignored as well. The sample prepared from electronic grade silicon presents the highest first discharge capacity, which is 440.5 mAh g-1.

  3. A comparative study of electrochemical properties of two kinds of carbon nanotubes as anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shubin; Huo, Junping; Song, Huaihe; Chen, Xiaohong [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 100029 Beijing (China)

    2008-01-01

    Two kinds of carbon nanotubes (CNTs), i.e., short carbon nanotubes (CNTs-1) synthesized by co-pyrolysis method and long carbon nanotubes (CNTs-2) produced using common CVD technique were comparatively investigated as anode materials for lithium ion batteries via transmission electron microscope (TEM), high-resolution TEM and a variety of electrochemical testing techniques. The test results showed that the reversible capacities of CNTs-1 electrode were 266 and 170 mAh g{sup -1} at the current densities of 0.2 and 0.8 mA cm{sup -2}, respectively, which were almost twice those of CNTs-2 electrode. The larger voltage hysteresis in CNTs-2 electrode was not only related to the surface functional groups on CNTs, but also to the surface resistance of CNTs, which results in greater hindrance and higher overvoltage during lithium extraction from electrode. The kinetics properties of these two CNTs electrodes were compared by AC impedance measurements. It was found that, both the surface film and charge-transfer resistances of CNTs-1 were significantly lower than those of CNTs-2; the lithium diffusion coefficient (D{sub Li}) of both CNTs electrodes decreased as the drop of voltage, but the magnitude of the D{sub Li} variation of CNTs-1 electrode was smaller than that of CNTs-2 electrode, indicating CNTs-1 exhibited higher electrochemical activity and more favorable kinetic properties during charge and discharge process. (author)

  4. A comparative study of electrochemical properties of two kinds of carbon nanotubes as anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yang Shubin; Huo Junping [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 100029 Beijing (China); Song Huaihe [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 100029 Beijing (China)], E-mail: songhh@mail.buct.edu.cn; Chen Xiaohong [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 100029 Beijing (China)

    2008-01-01

    Two kinds of carbon nanotubes (CNTs), i.e., short carbon nanotubes (CNTs-1) synthesized by co-pyrolysis method and long carbon nanotubes (CNTs-2) produced using common CVD technique were comparatively investigated as anode materials for lithium ion batteries via transmission electron microscope (TEM), high-resolution TEM and a variety of electrochemical testing techniques. The test results showed that the reversible capacities of CNTs-1 electrode were 266 and 170 mAh g{sup -1} at the current densities of 0.2 and 0.8 mA cm{sup -2}, respectively, which were almost twice those of CNTs-2 electrode. The larger voltage hysteresis in CNTs-2 electrode was not only related to the surface functional groups on CNTs, but also to the surface resistance of CNTs, which results in greater hindrance and higher overvoltage during lithium extraction from electrode. The kinetics properties of these two CNTs electrodes were compared by AC impedance measurements. It was found that, both the surface film and charge-transfer resistances of CNTs-1 were significantly lower than those of CNTs-2; the lithium diffusion coefficient (D{sub Li}) of both CNTs electrodes decreased as the drop of voltage, but the magnitude of the D{sub Li} variation of CNTs-1 electrode was smaller than that of CNTs-2 electrode, indicating CNTs-1 exhibited higher electrochemical activity and more favorable kinetic properties during charge and discharge process.

  5. Fabrication kinetics and properties of Ni-based nano-arrays embedded in anodic Al IIO 3 film

    Science.gov (United States)

    Yan, Hao; Zhang, Jiancheng; You, Chenxia; Song, Zhenwei; Yu, Benwei; Shen, Yue

    2008-02-01

    By direct current electrodeposition technique combined with the anodic aluminum oxide films, Ni-based nano-arrays were successfully performed. The structure was studied by X-ray diffraction and high-resolution transmission electron microscopy with selected-area electron diffraction. Energy dispersive spectroscopy was used to prove the composition of the prepared nanowires. The magnetic property curves of Ni-based nano-arrays were measured by a physical property measurement system. According to electrochemical analysis, the growth kinetics of the nanowires was studied by determining the relationship between the current and time under different parameters, such as electrolyte temperature and electrodeposition voltage.

  6. SnO2-graphene nanocomposite free-standing film as anode in lithium-ion batteries

    Science.gov (United States)

    Choi, Eunmi; Kim, Daeun; Lee, Ilbok; Chae, Su Jin; Kim, Areum; Pyo, Sung Gyu; Yoon, Songhun

    2015-09-01

    SnO2-reduced graphene oxide nanocomposite in the form of a free-standing film was prepared by simple chemical synthesis. The homogeneous and compact formation of the nanocomposite of SnO2 and reduced graphene oxide was confirmed by various analysis methods. When incorporated as anode in lithium-ion batteries, a high capacity (503 mAh g-1) and very stable cycle life were observed. These favorable properties probably arise from the efficient relaxation of high mechanical stress by the reduced graphene-oxide layers during the lithiation-delithiation process within SnO2. [Figure not available: see fulltext.

  7. Determination of Soil Base—Soluble Se by Anodic Stripping Voltammetry with Aurum Thin—Film Electrode

    Institute of Scientific and Technical Information of China (English)

    YANGZENG; HEYING; 等

    1994-01-01

    Determination of soil Se by anodic stripping voltammetry(ASV) with aurum thin-film electrode(ATFE)overcomes the interference of gold peak with selenium peak,and thus has a higher sensitivity with the miniumum detectable concentration being 0.017μg/mL,the standard deviation of the measured results leww than 0.012μg/g,the coefficient of variation lwoer than 10% ,and the recovery rate between 86% to 103%.Besides the measurement conditions,the digestion of soil sample was also studied in detail.

  8. Electrochemical and Mechanical Failure of Graphite-Based Anode Materials in Li-Ion Batteries for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Cheng Lin

    2016-01-01

    Full Text Available Graphite-based anode materials undergo electrochemical reactions, coupling with mechanical degradation during battery operation, can affect or deteriorate the performance of Li-ion batteries dramatically, and even lead to the battery failure in electric vehicle. First, a single particle model (SPM based on kinetics of electrochemical reactions was built in this paper. Then the Li-ion concentration and evolution of diffusion induced stresses (DISs within the SPM under galvanostatic operating conditions were analyzed by utilizing a mathematical method. Next, evolution of stresses or strains in the SPM, together with mechanical degradation of anode materials, was elaborated in detail. Finally, in order to verify the hypothesis aforementioned surface and morphology of the graphite-based anode dismantled from fresh and degraded cells after galvanostatic charge/discharge cycling were analyzed by X-ray diffraction (XRD, field-emission scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The results show that large volume changes of anode materials caused DISs during Li-ion insertion and extraction within the active particles. The continuous accumulations of DISs brought about mechanical failure of the anode eventually.

  9. Synthesis and Performance of Tungsten Disulfide/Carbon (WS2/C) Composite as Anode Material

    Science.gov (United States)

    Yuan, Zhengyong; Jiang, Qiang; Feng, Chuanqi; Chen, Xiao; Guo, Zaiping

    2017-09-01

    The precursors of an amorphous WS2/C composite were synthesized by a simple hydrothermal method using Na2WO4·2H2O and CH3CSNH2 as raw materials, polyethylene glycol as dispersant, and glucose as the carbon source. The as-synthesized precursors were further annealed at a low temperature in flowing argon to obtain the final materials (WS2/C composite). The structure and morphology of the WS2/C composite were characterized by x-ray diffraction, x-ray photoelectron spectroscopy, and scanning electron microscopy. The electrochemical properties were tested by galvanostatic charge/discharge testing and alternating current (AC) impedance measurements. The results show that the as-prepared amorphous WS2/C composite features both high specific capacity and good cycling performance at room temperature within the potential window from 3.0 V to 0.01 V (versus Li+/Li) at current density of 100 mAg-1. The achieved initial discharge capacity was 1080 mAhg-1, and 786 mAhg-1 was retained after 170 cycles. Furthermore, the amorphous WS2/C composite exhibited a lower charge/discharge plateau than bare WS2, which is more beneficial for use as an anode. The cyclic voltammetry and AC impedance testing further confirmed the change in the plateau and the decrease in the charge transfer resistance in the WS2/C composite. The chemical formation process and the electrochemical mechanism of the WS2/C composite are also presented. The amorphous WS2/C composite can be used as a new anode material for future applications.

  10. Could Borophene Be Used as a Promising Anode Material for High-Performance Lithium Ion Battery?

    Science.gov (United States)

    Zhang, Yang; Wu, Zhi-Feng; Gao, Peng-Fei; Zhang, Sheng-Li; Wen, Yu-Hua

    2016-08-31

    The rapid development of electronic products has inspired scientists to design and explore novel electrode materials with an ultrahigh rate of charging/discharging capability, such as two-dimensional (2-D) nanostructures of graphene and MoS2. In this study, another 2-D nanosheet, that is a borophene layer, has been predicted to be utilized as a promising anode material for high-performance Li ion battery based on density functional theory calculations. Our study has revealed that Li atom can combine strongly with borophene surface strongly and easily, and exist as a pure Li(+) state. A rather small energy barrier (0.007 eV) of Li diffusion leads to an ultrahigh diffusivity along an uncorrugated direction of borophene, which is estimated to be 10(4) (10(5)) times faster than that on MoS2 (graphene) at room temperature. A high Li storage capacity of 1239 mA·h/g can be achieved when Li content reaches 0.5. A low average operating voltage of 0.466 V and metallic properties result in that the borophene can be used as a possible anode material. Moreover, the properties of Li adsorption and diffusion on the borophene affected by Ag (111) substrate have been studied. It has been found that the influence of Ag (111) substrate is very weak. Li atom can still bind on the borophene with a strong binding energy of -2.648 eV. A small energy barrier of 0.033 eV can be retained for Li diffusion along the uncorrugated direction, which can give rise to a high Li diffusivity. Besides, the performances of borophene-based Na ion battery have been explored. Our results suggest that an extremely high rate capability could be expected in borophene-based Li ion battery.

  11. Composit, Nanoparticle-Based Anode material for Li-ion Batteries Applied in Hybrid Electric (HEV's)

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Malgorzata Gulbinska

    2009-08-24

    Lithium-ion batteries are promising energy storage devices in hybrid and electric vehicles with high specific energy values ({approx}150 Wh/kg), energy density ({approx}400 Wh/L), and long cycle life (>15 years). However, applications in hybrid and electric vehicles require increased energy density and improved low-temperature (<-10 C) performance. Silicon-based anodes are inexpensive, environmentally benign, and offer excellent theoretical capacity values ({approx}4000 mAh/g), leading to significantly less anode material and thus increasing the overall energy density value for the complete battery (>500 Wh/L). However, tremendous volume changes occur during cycling of pure silicon-based anodes. The expansion and contraction of these silicon particles causes them to fracture and lose electrical contact to the current collector ultimately severely limiting their cycle life. In Phase I of this project Yardney Technical Products, Inc. proposed development of a carbon/nano-silicon composite anode material with improved energy density and silicon's cycleability. In the carbon/nano-Si composite, silicon nanoparticles were embedded in a partially-graphitized carbonaceous matrix. The cycle life of anode material would be extended by decreasing the average particle size of active material (silicon) and by encapsulation of silicon nanoparticles in a ductile carbonaceous matrix. Decreasing the average particle size to a nano-region would also shorten Li-ion diffusion path and thus improve rate capability of the silicon-based anodes. Improved chemical inertness towards PC-based, low-temperature electrolytes was expected as an additional benefit of a thin, partially graphitized coating around the active electrode material.

  12. Anodic aluminum oxide films formed in mixed electrolytes of oxalic and sulfuric acid and their optical constants

    Science.gov (United States)

    Zhao, Li-Rong; Wang, Jian; Li, Yan; Wang, Cheng-Wei; Zhou, Feng; Liu, Wei-Min

    2010-01-01

    Porous anodic aluminum oxide (AAO) films were fabricated electrochemically in the mixed electrolytes with various volume ratios of 0.3 M C 2H 2O 4 and 0.3 M H 2SO 4. The transmission spectra with the interference fringes were measured and the modified Swanepoel method was used to determine the optical constants of the free standing AAO films. The calculated thickness agrees well with the measured thickness from the FE-SEM images of the cross section, which indicates that the modified Swanepoel method is very fit for the determination of the optical constants of the free standing AAO films. Meantime, with the decrease of the volume ratio of C 2H 2O 4 and H 2SO 4, the refractive index and thickness of AAO films increase, but the extinction coefficient decreases. The optical band gap is appropriately fitted to the direct transition model proposed by Tauc in the strong-absorption region of investigated films, and is derived from Tauc's extrapolation. The reasons were investigated.

  13. Investigation of Metal Oxide/Carbon Nano Material as Anode for High Capacity Lithium-ion Cells

    Science.gov (United States)

    Wu, James Jianjun; Hong, Haiping

    2014-01-01

    NASA is developing high specific energy and high specific capacity lithium-ion battery (LIB) technology for future NASA missions. Current state-of-art LIBs have issues in terms of safety and thermal stability, and are reaching limits in specific energy capability based on the electrochemical materials selected. For example, the graphite anode has a limited capability to store Li since the theoretical capacity of graphite is 372 mAh/g. To achieve higher specific capacity and energy density, and to improve safety for current LIBs, alternative advanced anode, cathode, and electrolyte materials are pursued under the NASA Advanced Space Power System Project. In this study, the nanostructed metal oxide, such as Fe2O3 on carbon nanotubes (CNT) composite as an LIB anode has been investigated.

  14. Electrochemical behaviors of anodic alumina sealed by Ce-Mo in NaCl solutions

    Institute of Scientific and Technical Information of China (English)

    TIAN Lian-peng; ZHAO Xu-hui; ZHAO Jing-mao; ZHANG Xiao-feng; ZUO Yu

    2006-01-01

    The elimination of toxic materials in sealing methods for anodic films on 1070 aluminum alloy was studied. The new process uses chemical treatments in cerium solution and an electrochemical treatment in a molybdate solution. Potentiodynamic polarization and electrochemical impedance spectroscopy(EIS) were used to study the influences of sealing methods on the corrosion behavior of anodic films in NaCl solutions. The results show that the Ce-Mo sealing makes the surface structure and morphology of anodic films uniform and compact. Ce and Mo produce a cooperative effect to improve the corrosion resistance of anodic films. Anodic films sealed by Ce-Mo provide high corrosion resistance both in acidic and basic solutions.

  15. Properties and microstructure of NiO/SDC materials for SOFC anode applications

    Institute of Scientific and Technical Information of China (English)

    CHENG Jigui; DENG Liping; ZHANG Benrui; SHI Ping; MENG Guangyao

    2007-01-01

    NiO/SDC composites and Ni/SDC cermets for solid oxide fuel cell (SOFC) anode applications were prepared from nickel oxide (NiO) and samaria doped ceria (SDC) powders by the powder metallurgy process. The physical and mechanical properties, as well as the microstructure of the NiO/SDC composites and the Ni/SDC cermets were investigated. It is shown that the sintering temperature of the NiO/SDC composites and NiO content plays an important role in determining the microstructure and properties of the NiO/SDC composites, which, in turn, influences the microstructure, electrical conductivity, and mechanical properties of the Ni/SDC cermets. The present study demonstrated that composition and tprocess parameters must be appropriately selected to optimize the microstructure and the properties of NiO/SDC materials for solid oxide fuel cell applications.

  16. Mechanism of lithium insertion into NiSi2 anode material for lithium ion batteries

    Institute of Scientific and Technical Information of China (English)

    WEN Zhongsheng; JI Shijun; SUN Juncai; TIAN Feng; TIAN Rujin; XIE Jingying

    2006-01-01

    As a promising high capacity anode material for lithium ion batteries, the lithium insertion performance and possible insertion mechanism of binary alloy of NiSi2 were discussed. The initial lithium insertion of crystal NiSi2 can reach up to 600 mAh·g-1 , but large irreversible capacity occurrs simultaneously for serious structure transformation and the irreversible phase forms. XRD and XPS were employed to detect the crystal structure and composition changes produced by lithium insertion. The lithium insertion-extraction behavior of NiSi2 electrode is similar to that of silicon after the first discharge. The structure stability seems related to the non-stoichimometric Ni-Si compound formed by lithium insertion into NiSi2.

  17. Mono-layer BC2 a high capacity anode material for Li-ion batteries

    Science.gov (United States)

    Hardikar, Rahul; Samanta, Atanu; Han, Sang Soo; Lee, Kwang-Ryeol; Singh, Abhishek

    2015-04-01

    Mono-layer of graphene with high surface area compared to the bulk graphite phase, shows less Li uptake. The Li activity or kinetics can be modified via defects and/or substitutional doping. Boron and Nitrogen are the best known dopants for carbonaceous anode materials. In particular, boron doped graphene shows higher capacity and better Li adsorption compared to Nitrogen doped graphene. Here, using first principles density functional theory calculations, we study the spectrum of boron carbide (BCx) mono-layer phases in order to estimate the maximum gravimetric capacity that can be achieved by substitutional doping in graphene. Our results show that uniformly boron doped BC2 phase shows a high capacity of? 1400 mAh/g, much higher than previously reported capacity of BC3. Supported by Korea Institute of Science and Technology.

  18. Defective graphene as promising anode material for Na-ion battery and Ca-ion battery

    CERN Document Server

    Datta, Dibakar; Shenoy, Vivek B

    2013-01-01

    We have investigated adsorption of Na and Ca on graphene with divacancy (DV) and Stone-Wales (SW) defect. Our results show that adsorption is not possible on pristine graphene. However, their adsorption on defective sheet is energetically favorable. The enhanced adsorption can be attributed to the increased charge transfer between adatoms and underlying defective sheet. With the increase in defect density until certain possible limit, maximum percentage of adsorption also increases giving higher battery capacity. For maximum possible DV defect, we can achieve maximum capacity of 1459 mAh/g for Na-ion batteries (NIBs) and 2900 mAh/g for Ca-ion batteries (CIBs). For graphene full of SW defect, we find the maximum capacity of NIBs and CIBs is around 1071 mAh/g and 2142 mAh/g respectively. Our results will help create better anode materials with much higher capacity and better cycling performance for NIBs and CIBs.

  19. Electrodeposited gold nanoparticles on carbon nanotube-textile: Anode material for glucose alkaline fuel cells

    KAUST Repository

    Pasta, Mauro

    2012-06-01

    In the present paper we propose a new anode material for glucose-gluconate direct oxidation fuel cells prepared by electrodepositing gold nanoparticles onto a conductive textile made by conformally coating single walled carbon nanotubes (SWNT) on a polyester textile substrate. The electrodeposition conditions were optimized in order to achieve a uniform distribution of gold nanoparticles in the 3D porous structure of the textile. On the basis of previously reported studies, the reaction conditions (pH, electrolyte composition and glucose concentration) were tuned in order to achieve the highest oxidation rate, selectively oxidizing glucose to gluconate. The electrochemical characterization was carried out by means of cyclic voltammetry. © 2012 Elsevier B.V. All rights reserved.

  20. Mn3O4/CNTs composite as anode materials for lithium-ion batteries

    Directory of Open Access Journals (Sweden)

    Xu Xiangjun

    2015-01-01

    Full Text Available Transition metal oxides especially manganese oxides are being intensively studied as candidate anode materials for next generation lithium ion batteries in high efficiency energy storage applications. In this paper, Mn3O4/CNTs composite is prepared via a facile one-step solvothermal method. The results of XRD and SEM showed that Mn3O4 uniformly coated on the surface of CNTs. It could deliver a reversible charge capacity of 809.9 mA h g-1 at the current density of 40 mA g-1, and the specific discharge capacity slightly increased from 644.2 mA h g-1 to 796.1 mA h g-1 after 50 cycles at a current density of 160 mA g-1 demonstrating excellent cycling stability.

  1. Nitrogen-rich graphene from small molecules as high performance anode material.

    Science.gov (United States)

    Gao, Weiwei; Huang, Hao; Shi, Hongyan; Feng, Xun; Song, Wenbo

    2014-10-17

    Nitrogen-rich graphene sheets were successfully achieved via facile thermal condensation of glucose and dicyandiamide at different temperatures during which dicyandiamide acts both as nitrogen source and sacrifice template. Devoid of surfactants or poisonous organic solvents, this small-molecule synthetic approach is a simple and cost-effective way to obtain nitrogen-rich graphene sheets (NRGS) with high specific surface area and large pore volume. Shown to be a promising anode material, the NRGS displayed high reversible capacity, excellent rate capability, and superior cycle performance. The superior lithium-storage performance is ascribed to the unique features of NRGS, including a large quantity of defects due to the high nitrogen doping level, favorable lithium ion transportation channels by virtue of the large surface area, and ultrahigh pore volume, as well as the crumpled two-dimensional structure.

  2. Ti-doped Mn3O4 composite as anode materials for lithium-ion batteries

    Science.gov (United States)

    Ding, Peng; Yin, Muyi; Li, Wei; Liu, Fulin; Zheng, Cheng

    2017-01-01

    Transition metal oxides especially manganese oxides are being intensively studied as candidate anode materials for next generation lithium ion batteries in high efficiency energy storage applications. In this paper, Ti-doped Mn3O4 composite is prepared via a facile one-step solvothermal method. The results of XRD and SEM showed that the product is cotton-shaped mixed up with the Mn3O4 particles. It could deliver a reversible charge capacity of 557.8 mA h g-1 at the current density of 35.5 mA g-1, and thex specific discharge capacity is still have 478.1 mA h g-1 after 40 cycles at a current density of 35.5 mA g-1 demonstrating good cycling stability.

  3. Effect of the synthesis method of SnSb anode materials on their electrochemical properties

    Institute of Scientific and Technical Information of China (English)

    Chaoli Yin; Hailei Zhao; Hong Guo; Xianliang Huang; Weihua Qiu

    2007-01-01

    SnSb alloy powders for the anode of Li-ion batteries were synthesized by two kinds of reduction precipitation methods:solution titration and rapid mixing. Two kinds of SnSb alloy powders showed different phase compositions and particle morphologies although the same starting materials were used. The SnSb alloy electrode synthesized by titration exhibits high reversible specific capacity and good cycling stability, whereas the rapid-mixing sample shows high irreversible capacity and fast capacity fade. The broad particle size distribution of SnSb powders synthesized by titration is considered to be responsible for the improvement of cycling stability. The initial charge-discharge efficiency exceeding 80% has been obtained for the titration sample. The electrochemical reaction process of two kinds of synthesized SnSb composite electrodes was characterized by cyclic voltammetry and AC impedance techniques.

  4. GeO2 Thin Film Deposition on Graphene Oxide by the Hydrogen Peroxide Route: Evaluation for Lithium-Ion Battery Anode.

    Science.gov (United States)

    Medvedev, Alexander G; Mikhaylov, Alexey A; Grishanov, Dmitry A; Yu, Denis Y W; Gun, Jenny; Sladkevich, Sergey; Lev, Ovadia; Prikhodchenko, Petr V

    2017-03-15

    A peroxogermanate thin film was deposited in high yield at room temperature on graphene oxide (GO) from peroxogermanate sols. The deposition of the peroxo-precursor onto GO and the transformations to amorphous GeO2, crystalline tetragonal GeO2, and then to cubic elemental germanium were followed by electron microscopy, XRD, and XPS. All of these transformations are influenced by the GO support. The initial deposition is explained in view of the sol composition and the presence of GO, and the different thermal transformations are explained by reactions with the graphene support acting as a reducing agent. As a test case, the evaluation of the different materials as lithium ion battery anodes was carried out revealing that the best performance is obtained by amorphous germanium oxide@GO with >1000 mAh g(-1) at 250 mA g(-1) (between 0 and 2.5 V vs Li/Li(+) cathode), despite the fact that the material contained only 51 wt % germanium. This is the first demonstration of the peroxide route to produce peroxogermanate thin films and thereby supported germanium and germanium oxide coatings. The advantages of the process over alternative methodologies are discussed.

  5. Polydopamine as a new modification material to accelerate startup and promote anode performance in microbial fuel cells

    Science.gov (United States)

    Du, Qing; An, Jingkun; Li, Junhui; Zhou, Lean; Li, Nan; Wang, Xin

    2017-03-01

    The bacterial anode material is important to the performance of microbial fuel cells (MFCs) because its characteristics affect the biofilm formation and extracellular electron transfer. Here we find that a superhydrophilic semiconductor, polydopamine (PDA), is an effective modification material for the anode to accelerate startup and improve power density. When the activated carbon anode is added with 50% (wt.) PDA, the startup time is 14% shorter than the control (from 88 h to 76 h), with a 31% increase in maximum power density from 613 ± 9 to 803 ± 6 mW m-2, and the Columbic efficiency increases from 19% to 48%. These can be primarily attributed to the abundant functional groups (such as amino group, and catechol functions) introduced by PDA that improve hydrophilicity and extracellular electron transfer. PDA also increases proportions of Proteobacteria and Firmicutes families, indicating that PDA has a selective effect on anode microbial community. Our findings provide a new approach to accelerate anode biofilm formation and enhance MFC power output by modification of biocompatible PDA.

  6. Onion-like carbon coated CuO nanocapsules: A highly reversible anode material for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xianguo, E-mail: liuxianguohugh@gmail.com [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002 (China); Bi, Nannan; Feng, Chao [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002 (China); Or, Siu Wing [Department of Electrical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Sun, Yuping [Center for Engineering practice and Innovation Education, Anhui University of Technology, Maanshan 243002 (China); Jin, Chuangui; Li, Weihuo; Xiao, Feng [Anhui Key Laboratory of Metal Materials and Processing, School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002 (China)

    2014-02-25

    Highlights: • Onion-like carbon–coated CuO nanocapsules have been synthesized. • Onion-like carbon leads to the improved stability and electric conductivity. • CuO/C nanocapsules maintain a reversible capacity of 628.7 mA h g{sup −1} after 50 cycles. -- Abstract: The synthesis and characterization of CuO/C nanocapsules for application as anode material in lithium ion batteries are reported. Introduction of onion-like carbon shell on the CuO nanoparticles leads to the improved stability, electric conductivity and electrochemical performance. When evaluated as potential anode materials for lithium-ion batteries, the novel CuO/C nanocapsules deliver an initial discharge capacity of 1043.9 mA h g{sup −1} at 100 mA g{sup −1} and maintain a high reversible capacity of 628.7 mA h g{sup −1} after 50 charge–discharge cycles, much higher than those of the CuO nanoparticles. A postmortem analysis of the CuO and CuO/C anodes subjected to prolonged cycling reveals the existence of a lower degree of surface cracking and particle breakage in the CuO/C anode than the CuO anode.

  7. Anode materials for hydrogen sulfide containing feeds in a solid oxide fuel cell

    Science.gov (United States)

    Roushanafshar, Milad

    SOFCs which can directly operate under high concentration of H2S would be economically beneficial as this reduces the cost of gas purification. H2S is highly reactive gas specie which can poison most of the conventional catalysts. As a result, developing anode materials which can tolerate high concentrations of H2S and also display high activity toward electrochemical oxidation of feed is crucial and challenging for this application. The performance of La0.4Sr0.6TiO3+/-delta -Y0.2Ce0.8O2-delta (LST-YDC) composite anodes in solid oxide fuel cells significantly improved when 0.5% H2 S was present in syngas (40% H2, 60% CO) or hydrogen. Gas chromatography and mass spectrometry analyses revealed that the rate of electrochemical oxidation of all fuel components improved when H2S containing syngas was present in the fuel. Electrochemical stability tests performed under potentiostatic condition showed that there was no power degradation for different feeds, and that there was power enhancement when 0.5% H2S was present in various feeds. The mechanism of performance improvement by H2S was discussed. Active anodes were synthesized via wet chemical impregnation of different amounts of La0.4Ce0.6O1.8 (LDC) and La 0.4Sr0.6TiO3 (L4ST) into porous yttria-stabilized zirconia (YSZ). Co-impregnation of LDC with LS4T significantly improved the performance of the cell from 48 mW.cm-2 (L4ST) to 161 mW.cm -2 (LDC-L4ST) using hydrogen as fuel at 900 °C. The contribution of LDC to this improvement was investigated using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) as well as transmission electron microscopy (TEM). EIS measurements using symmetrical cells showed that the polarization resistance decreased from 3.1¦O.cm 2 to 0.5 O.cm2 when LDC was co-impregnated with LST, characterized in humidified H2 (3% H2O) at 900 °C. In addition, the microstructure of the cell was modified when LDC was impregnated prior to L4ST into the porous YSZ. TEM and SEM

  8. The effect of different oxide layers on the sensing properties of anodic alumina nanoporous film

    Directory of Open Access Journals (Sweden)

    H. Abbasian

    2014-03-01

    Full Text Available In the present work, anodized aluminum oxide template was prepared by accelerated mild anodization technique in 0.6M phosphoric aside and 175 V, anodization voltage. Pore widening was performed by chemical etching in 0.5M phosphoric acid for 8, 16, 32, 40 minutes. Scanning Electron Microscopy (SEM images showed the pores, diameter exponentially increases with etching time. By depositing silver contacts on the prepared samples and using an RC circuit for applying impedance spectroscopy, the characteristics of the humidity sensor based on constructed samples were investigated. The maximum response was seen for the sample etched for 40 minutes. For this sample, the detectable threshold of relative moisture was 30% and the response and the recovery time were 8, 2 seconds, respectively

  9. Optical thin films and coatings from materials to applications

    CERN Document Server

    Flory, Francois

    2013-01-01

    Optical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. This book provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas.$bOptical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. Optical thin films and coatings provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas. Part one explores the design and manufacture of optical coatings. Part two highlights unconventional features of optical thin films including scattering properties of random structures in thin films, optical properties of thin film materials at short wavelengths, thermal properties and colour effects. Part three focusses on novel materials for optical thin films and coatings...

  10. Nanoparticle Decorated Ultrathin Porous Nanosheets as Hierarchical Co3O4 Nanostructures for Lithium Ion Battery Anode Materials

    DEFF Research Database (Denmark)

    Mujtaba, Jawayria; Sun, Hongyu; Huang, Guoyong;

    2016-01-01

    We report a facile synthesis of a novel cobalt oxide (Co3O4) hierarchical nanostructure, in which crystalline core-amorphous shell Co3O4 nanoparticles with a bimodal size distribution are uniformly dispersed on ultrathin Co3O4 nanosheets. When tested as anode materials for lithium ion batteries...

  11. Mesoporous Germanium Anode Materials for Lithium-Ion Battery with Exceptional Cycling Stability in Wide Temperature Range.

    Science.gov (United States)

    Choi, Sinho; Cho, Yoon-Gyo; Kim, Jieun; Choi, Nam-Soon; Song, Hyun-Kon; Wang, Guoxiu; Park, Soojin

    2017-04-01

    Porous structured materials have unique architectures and are promising for lithium-ion batteries to enhance performances. In particular, mesoporous materials have many advantages including a high surface area and large void spaces which can increase reactivity and accessibility of lithium ions. This study reports a synthesis of newly developed mesoporous germanium (Ge) particles prepared by a zincothermic reduction at a mild temperature for high performance lithium-ion batteries which can operate in a wide temperature range. The optimized Ge battery anodes with the mesoporous structure exhibit outstanding electrochemical properties in a wide temperature ranging from -20 to 60 °C. Ge anodes exhibit a stable cycling retention at various temperatures (capacity retention of 99% after 100 cycles at 25 °C, 84% after 300 cycles at 60 °C, and 50% after 50 cycles at -20 °C). Furthermore, full cells consisting of the mesoporous Ge anode and an LiFePO4 cathode show an excellent cyclability at -20 and 25 °C. Mesoporous Ge materials synthesized by the zincothermic reduction can be potentially applied as high performance anode materials for practical lithium-ion batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Si doped T6 carbon structure as an anode material for Li-ion batteries: An ab initio study

    Science.gov (United States)

    Rajkamal, A.; Kumar, E. Mathan; Kathirvel, V.; Park, Noejung; Thapa, Ranjit

    2016-11-01

    First-principles calculations are performed to identify the pristine and Si doped 3D metallic T6 carbon structure (having both sp2 and sp3 type hybridization) as a new carbon based anode material. The π electron of C2 atoms (sp2 bonded) forms an out of plane network that helps to capture the Li atom. The highest Li storage capacity of Si doped T6 structure with conformation Li1.7Si1C5 produces theoretical specific capacity of 632 mAh/g which substantially exceeding than graphite. Also, open-circuit voltage (OCV) with respect to Li metal shows large negative when compared to the pristine T6 structure. This indicates modifications in terms of chemical properties are required in anode materials for practical application. Among various doped (Si, Ge, Sn, B, N) configuration, Si doped T6 structure provides a stable positive OCV for high Li concentrations. Likewise, volume expansion study also shows Si doped T6 structure is more stable with less pulverization and substantial capacity losses in comparison with graphite and silicon as an anode materials. Overall, mixed hybridized (sp2 + sp3) Si doped T6 structure can become a superior anode material than present sp2 hybridized graphite and sp3 hybridized Si structure for modern Lithium ion batteries.

  13. Green synthesis of boron doped graphene and its application as high performance anode material in Li ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, Madhumita; Sreena, K.P.; Vinayan, B.P.; Ramaprabhu, S., E-mail: ramp@iitm.ac.in

    2015-01-15

    Graphical abstract: Boron doped graphene (B-G), synthesized by simple hydrogen induced reduction technique using boric acid as boron precursor, have more uneven surface as a result of smaller bonding distance of boron compared to carbon, showed high capacity and high rate capability compared to pristine graphene as an anode material for Li ion battery application. - Abstract: The present work demonstrates a facile route for the large-scale, catalyst free, and green synthesis approach of boron doped graphene (B-G) and its use as high performance anode material for Li ion battery (LIB) application. Boron atoms were doped into graphene framework with an atomic percentage of 5.93% via hydrogen induced thermal reduction technique using graphite oxide and boric acid as precursors. Various characterization techniques were used to confirm the boron doping in graphene sheets. B-G as anode material shows a discharge capacity of 548 mAh g{sup −1} at 100 mA g{sup −1} after 30th cycles. At high current density value of 1 A g{sup −1}, B-G as anode material enhances the specific capacity by about 1.7 times compared to pristine graphene. The present study shows a simplistic way of boron doping in graphene leading to an enhanced Li ion adsorption due to the change in electronic states.

  14. Morphological control of anodic crystalline TiO{sub 2} nanochannel films for use in size-selective photocatalytic decomposition of organic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Tsuji, E., E-mail: e-tsuji@eng.hokudai.ac.jp [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Division of Materials Chemistry, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Taguchi, Y. [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Aoki, Y. [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Division of Materials Chemistry, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Hashimoto, T.; Skeldon, P.; Thompson, G.E. [Corrosion and Protection Centre, School of Materials, The University of Manchester, Manchester, M13 9PL England (United Kingdom); Habazaki, H. [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan); Division of Materials Chemistry, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628 (Japan)

    2014-05-01

    Graphical abstract: - Highlights: • The crystalline TiO{sub 2} nanochannel films were formed by anodizing titanium at 20 V in glycerol electrolyte containing various amounts of K{sub 3}PO{sub 4}, K{sub 2}HPO{sub 4} and KH{sub 2}PO{sub 4} at 433 K. • The growth rate of the films increased with an increase in the basicity of the electrolyte, leading to highly ordered nanochannel structures (the pore size was as small as ∼10 nm). • Size-selective photocatalytic decomposition for small organic molecules was achieved by utilizing the highly ordered TiO{sub 2} nanochannel films. - Abstract: We report the size-selective photocatalytic decomposition of organic molecules using crystalline anodic TiO{sub 2} nanochannel films as the photocatalyst. The porous TiO{sub 2} films were formed by anodizing titanium at 20 V in glycerol electrolyte containing various amounts of K{sub 3}PO{sub 4}, K{sub 2}HPO{sub 4}, and KH{sub 2}PO{sub 4} at 433 K. Regardless of the electrolyte composition, the as-formed TiO{sub 2} films had a crystalline anatase structure. The basicity of the electrolyte markedly influenced the morphology of the TiO{sub 2} nanochannel films; more regular nanochannels developed with increasing basicity of the electrolyte. Because the diameter of the nanochannels in the films formed in a basic electrolyte was as small as ∼10 nm, the anodic TiO{sub 2} nanochannel films with a thickness of 5 μm revealed a selective photocatalytic decomposition of methylene blue (MB) in a mixture of MB and direct red 80 (DR) kept under UV irradiation. The importance of the diameter of the nanochannels and their uniformity for size-selective decomposition of organic molecules were investigated.

  15. Fabrication of Polymeric Antireflection Film Manufactured by Anodic Aluminum Oxide Template on Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Jenn-Kai Tsai

    2017-03-01

    Full Text Available In this study, high energy conversion efficient dye-sensitized solar cells (DSSCs were successfully fabricated by attaching a double anti-reflection (AR layer, which is composed of a subwavelength moth-eye structured polymethyl methacrylate (PMMA film and a polydimethylsiloxane (PDMS film. An efficiency of up to 6.79% was achieved. The moth-eye structured PMMA film was fabricated by using an anodic aluminum oxide (AAO template which is simple, low-cost and scalable. The nano-pattern of the AAO template was precisely reproduced onto the PMMA film. The photoanode was composed of Titanium dioxide (TiO2 nanoparticles (NPs with a diameter of 25 nm deposited on the fluorine-doped tin oxide (FTO glass substrate and the sensitizer N3. The double AR layer was proved to effectively improve the short-circuit current density (JSC and conversion efficiency from 14.77 to 15.79 mA/cm2 and from 6.26% to 6.79%, respectively.

  16. Electrical and Mechanical Performance of Carbon Fiber-Reinforced Polymer Used as the Impressed Current Anode Material

    Directory of Open Access Journals (Sweden)

    Ji-Hua Zhu

    2014-07-01

    Full Text Available An investigation was performed by using carbon fiber-reinforced polymer (CFRP as the anode material in the impressed current cathodic protection (ICCP system of steel reinforced concrete structures. The service life and performance of CFRP were investigated in simulated ICCP systems with various configurations. Constant current densities were maintained during the tests. No significant degradation in electrical and mechanical properties was found for CFRP subjected to anodic polarization with the selected applied current densities. The service life of the CFRP-based ICCP system was discussed based on the practical reinforced concrete structure layout.

  17. New Sn-based composites as anode materials for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Aboulaich, A.; Mouyane, M.; Robert, F.; Lippens, P.-E.; Olivier-Fourcade, J.; Jumas, J.-C. [Laboratoire des Agregats Moleculaires et Materiaux Inorganiques (CNRS UMR 5072), Universite Montpellier II, CC 015, Place E. Bataillon, 34095 Montpellier Cedex 5 (France); Willmann, P. [Centre National d' Etudes Spatiales, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9 (France)

    2007-12-06

    A new strategy was developed to synthesize tin-composite materials. The Sn:BPO{sub 4} and Sn:CaSiO{sub 3} composites were obtained by solid state reaction, but the BPO{sub 4} and CaSiO{sub 3} matrices were synthesized by solid state reaction and sol-gel method, respectively. These materials are characterized by X-ray diffraction, {sup 119}Sn Moessbauer spectroscopy and electrochemical tests. The results show that these new materials are efficient during electrochemical cycling (500 mAh g{sup -1}), because of a good dispersion of Sn particles into the matrix. From the second cycle, charge and discharge reversibility is linked to both reversible Li{sub X}Sn alloy forming and the modification of the tin particle surface showed by Conversion Electron Moessbauer spectroscopy (CEMS) which allows us to characterize the sample surface. The irreversible capacity observed for the first charge/discharge cycle is due to tin oxide reduction and passivation of the anode surface by electrolyte solution decomposition (SEI layer). (author)

  18. New Sn-based composites as anode materials for Li-ion batteries

    Science.gov (United States)

    Aboulaich, A.; Mouyane, M.; Robert, F.; Lippens, P.-E.; Olivier-Fourcade, J.; Willmann, P.; Jumas, J.-C.

    A new strategy was developed to synthesize tin-composite materials. The Sn:BPO 4 and Sn:CaSiO 3 composites were obtained by solid state reaction, but the BPO 4 and CaSiO 3 matrices were synthesized by solid state reaction and sol-gel method, respectively. These materials are characterized by X-ray diffraction, 119Sn Mössbauer spectroscopy and electrochemical tests. The results show that these new materials are efficient during electrochemical cycling (500 mAh g -1), because of a good dispersion of Sn particles into the matrix. From the second cycle, charge and discharge reversibility is linked to both reversible Li XSn alloy forming and the modification of the tin particle surface showed by Conversion Electron Mössbauer spectroscopy (CEMS) which allows us to characterize the sample surface. The irreversible capacity observed for the first charge/discharge cycle is due to tin oxide reduction and passivation of the anode surface by electrolyte solution decomposition (SEI layer).

  19. Nanostructured metal oxide-based materials as advanced anodes for lithium-ion batteries.

    Science.gov (United States)

    Wu, Hao Bin; Chen, Jun Song; Hng, Huey Hoon; Lou, Xiong Wen David

    2012-04-21

    The search for new electrode materials for lithium-ion batteries (LIBs) has been an important way to satisfy the ever-growing demands for better performance with higher energy/power densities, improved safety and longer cycle life. Nanostructured metal oxides exhibit good electrochemical properties, and they are regarded as promising anode materials for high-performance LIBs. In this feature article, we will focus on three different categories of metal oxides with distinct lithium storage mechanisms: tin dioxide (SnO(2)), which utilizes alloying/dealloying processes to reversibly store/release lithium ions during charge/discharge; titanium dioxide (TiO(2)), where lithium ions are inserted/deinserted into/out of the TiO(2) crystal framework; and transition metal oxides including iron oxide and cobalt oxide, which react with lithium ions via an unusual conversion reaction. For all three systems, we will emphasize that creating nanomaterials with unique structures could effectively improve the lithium storage properties of these metal oxides. We will also highlight that the lithium storage capability can be further enhanced through designing advanced nanocomposite materials containing metal oxides and other carbonaceous supports. By providing such a rather systematic survey, we aim to stress the importance of proper nanostructuring and advanced compositing that would result in improved physicochemical properties of metal oxides, thus making them promising negative electrodes for next-generation LIBs.

  20. Solution-deposited Li4Ti5O12 thin films as anode for lithium ion battery

    Institute of Scientific and Technical Information of China (English)

    WU Xian-ming; XIAO Zhuo-bing; MA Ming-you; CHEN Shang; HE Ze-qiang; LIU Jian-ben

    2006-01-01

    The technique of solution deposition was employed to prepare Li4Ti5O12 thin film using lithium acetate and TiO(C4H9)4 as starting materials. The structural and electrochemical properties of the thin films were studied by X-ray diffraction, cyclic voltammetry, galvanostatic charge-discharge experiments, and potential step technique. The results show that the thin film prepared by this method is of pure phase with a spinel framework structure. The capacity of the thin film annealed at 750 ℃ for 1 h is approximately 57 μA·h/(cm2·μm). The film possesses excellent cycling behavior with a 0.08% capacity loss per cycle after being cycled 50 times. Potential step technique shows that the average chemical diffusion coefficient of lithium ion in the thin film is approximately 4.5×10-11 cm2/s.

  1. Properties and Structure of the LiCl-films on Lithium Anodes in Liquid Cathodes

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Hennesø, Erik

    2016-01-01

    Lithium anodes passivated by LiCl layers in different types of liquid cathodes (catholytes) based on LiAlCl4 in SOCl2 or SO2 have been studied by means of impedance spectroscopy. The impedance spectra have been fitted with two equivalent circuits using a nonlinear least squares fit program...

  2. Applications of nano-composite materials for improving the performance of anode-supported electrolytes of SOFCs

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong-Jin; Moon, Hwan; Park, Hae-Gu; Yoon, Dae Il; Hyun, Sang-Hoon [School of Advanced Materials Science and Engineering, Yonsei Univ., Seoul 120-749 (Korea)

    2010-01-15

    In order to improve the performance of the anode-supported electrolyte of solid oxide fuel cells (SOFCs), the anode electrode is modified by inserting an anode functional layer of nano-composite powders between a Ni-YSZ electrode and YSZ electrolyte. The NiO-YSZ nano-composite powders are fabricated by coating nano-sized Ni and YSZ particles on the YSZ core particle by the Pechini process. The reduction of the polarization resistance of a single cell that is applied to the anode functional layer is attributed to the increasing reaction of three-phase boundaries (TPBs) within the layer and the micro-structured uniformity in the electrode. Two methods were used, namely tape-casting/dip-coating and tape-casting/co-firing, for studying the performance. It can be concluded that the cell with an anode functional layer thickness (15-20 {mu}m) and a microstructure of NiO-YSZ nano-composite materials which was fabricated by the tape-casting/dip-coating method improved the output power (to 1.3 W cm{sup -2}) at 800 C using hydrogen as fuel and air as an oxidant. (author)

  3. Fabrication of anode supported PEN for solid oxide fuel cell

    Institute of Scientific and Technical Information of China (English)

    谢淑红; 崔崑; 夏风; 肖建中

    2004-01-01

    Fabrication process for anode supported planar PEN of intermediate temperature solid oxide fuel cell (SOFC) was introduced, in which tape casting and screen printing methods were used. Gd2O3 doped CeO2(GDC) powders were prepared by solid reaction method. Anode tape was produced by tape casting. Electrolyte and cathode were produced by screen printing. The GDC powder's component, thermal expand coefficient, the porosity, density and microstructure of anode and electrolyte were investigated . It was shown that an bi-layer with dense thin electrolyte film and porous anode support and with good coherency of the electrolyte film to the anode could be realized after co-sintering the green tape at 1 350℃ by optimizing the power characteristics of the starting materials in the slurry.

  4. Emotional reactivity to film material in Alzheimer's disease.

    Science.gov (United States)

    Mograbi, Daniel C; Brown, Richard G; Morris, Robin G

    2012-01-01

    To explore emotional reactivity in mild to moderate Alzheimer's disease (AD) using film material, investigating the influence of dementia-related material and awareness of condition. Twenty-two patients with AD and 21 healthy older adults viewed films with positive, neutral or negative content, including a film about dementia. Reactivity was measured through a self-report questionnaire and filming of facial expressions. Awareness of condition was assessed contrasting patients' versus informants' versions of an anosognosia questionnaire. The AD patients showed reduced self-reported reactivity to negative films, but exhibited a pattern of facial responses similar to controls for all films. Awareness was associated with frequency of negative facial expressions during the dementia film. AD patients may have impairments in self-reported reactivity to negative stimuli. Awareness may mediate responses to dementia-related material. Copyright © 2012 S. Karger AG, Basel.

  5. Semiconducting behavior of the anodically passive films formed on AZ31B alloy

    Directory of Open Access Journals (Sweden)

    A. Fattah-alhosseini

    2014-12-01

    Full Text Available This work includes determination of the semiconductor character and estimation of the dopant levels in the passive film formed on AZ31B alloy in 0.01 M NaOH, as well as the estimation of the passive film thickness as a function of the film formation potential. Mott–Schottky analysis revealed that the passive films displayed n-type semiconductive characteristics, where the oxygen vacancies and interstitials preponderated. Based on the Mott–Schottky analysis, it was shown that the calculated donor density increases linearly with increasing the formation potential. Also, the electrochemical impedance spectroscopy (EIS results indicated that the thickness of the passive film was decreased linearly with increasing the formation potential. The results showed that decreasing the formation potential offer better conditions for forming the passive films with higher protection behavior, due to the growth of a much thicker and less defective films.

  6. Electrochemical Film Formation on Magnesium Metal in an Ionic Liquid That Dissolves Metal Triflate and Its Application to an Active Material with Anion Charge Carrier.

    Science.gov (United States)

    Shiga, Tohru; Kato, Yuichi; Inoue, Masae

    2016-11-16

    Irregular metallic growth at the anode during recharging of batteries can seriously influence the safety of batteries. To address this problem, we have attempted to design active anode materials with anion charge carriers and recently observed the formation and dissolution of an electrochemical film by triflate anions (CF3SO3(-)) at the surface of magnesium in an ionic liquid (IL) electrolyte of Mg(CF3SO3)2, which represents a rare anode material. The effect of heterogeneous cations on film formation was examined in this work. In an IL that dissolves NaCF3SO3, sodium ions with a lower reduction potential than Mg(2+)/Mg would not be expected to assist film formation. However, to our surprise, we discovered that some sodium ions are involved in film formation. The sodium ions are believed to act as a cross-linking point for the formation of a film network, which resulted in fairly good reversibility for film formation. In a Ce(CF3SO3)3-IL electrolyte, an electrochemically formed film free of Ce(3+) was obtained. The trivalent cerium cations were deactivated and transformed to an oxide on Mg metal. However, the reversibility of film formation in the Ce(CF3SO3)3 system did not meet the expected level. By coupling the film formation and dissolution behavior with a V2O5 cathode, a rechargeable battery was fabricated with dual ion transport species of Na(+) or Ce(3+) for the cathode and CF3SO3(-) for the anode. The unique battery with NaCF3SO3 is demonstrated to exhibit good discharge/charge performance with long-term cyclability.

  7. Morphology and performances of the anodic oxide films on Ti6Al4V alloy formed in alkaline-silicate electrolyte with aminopropyl silane addition under low potential

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jiali; Wang, Jinwei, E-mail: wangjw@ustb.edu.cn; Yuan, Hongye

    2013-11-01

    Oxide films on Ti6Al4V alloy are prepared using sodium hydroxide–sodium silicate as the base electrolyte with addition of aminopropyl trimethoxysilane (APS) as additive by potentiostatic anodizing under 10 V. APS is incorporated into the films during anodizing and the surface morphology of the oxide films is changed from particle stacked to honeycomb-like porous surfaces as shown by scanning electron microscopy (SEM) with Energy Disperse Spectroscopy (EDX). The surface roughness and aminopropyl existence on the oxide films result in their differences in wettability as tested by the surface profile topography and contact angle measurements. The anti-abrasive ability of the anodic films is improved with the addition of APS due to its toughening effects and serving as lubricants in the ceramic oxide films as measured by ball-on-disk friction test. Also, potentiodynamic corrosion test proves that their anticorrosive ability in 3.5 wt.% NaCl is greatly improved as reflected by their much lower corrosion current (I{sub corr}) and higher corrosion potential (E{sub corr}) than those of the substrate.

  8. Ex Situ Investigation of Anisotropic Interconnection in Silicon-Titanium-Nickel Alloy Anode Material

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jong-Soo; Alaboina, Pankaj Kumar; Kang, Chan-Soon; Kim, Seul-Cham; Son, Seoung-Bum; Suh, Soonsung; Kim, Jaehyuk; Kwon, Seunguk; Lee, Se-Hee; Oh, Kyu-Hwan; Cho, Sung-Jin

    2017-03-10

    Herein we investigate the nanostructural evolution of Silicon-Titanium-Nickel (Si-Ti-Ni) ternary alloy material synthesized by melt spinning process for advanced lithium-ion battery anode. The synthesized material was found to have nano-Silicon particles dispersed in the Ti4Ni4Si7 (STN) alloy buffering matrix and was characterized by X-ray diffraction (XRD), High resolution- transmission electron microscope (HR-TEM), Scanning transmission electron microscopes - energy dispersive X-ray spectrometer (STEM-EDS), and electrochemical performance test. The role of STN matrix is to accommodate the volume expansion stresses of the dispersed Si nanoparticles. However, an interesting behavior was observed during cycling. The Si nanoparticles were observed to form interconnection channels growing through the weak STN matrix cracks and evolving to a network isolating the STN matrix into small puddles. This unique nanostructural evolution of Si particles and isolation of the STN matrix failing to offer significant buffering effect to the grown Si network eventually accelerates more volume expansions during cycling due to less mechanical confinement and leads to performance degradation and poor cycle stability.

  9. Ultrathin Li4Ti5O12 nanosheets as anode materials for lithium and sodium storage

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xuyong; Zou, Hailin; Xiang, Hongfa; Guo, Xin; Zhou, Tianpei; Wu, Yucheng; Xu, Wu; Yan, Pengfei; Wang, Chong M.; Zhang, Jiguang; Yu, Yan

    2016-06-13

    Two-dimensional Li4Ti5O12 (LTO) nanosheets are prepared via a surfactant assisted hydrothermal process. Polyether (P123) was added as the surfactant to modify the surface and control the microstructure of the hydrothermal products and thus affect the electrochemical performance of the as-synthesized LTO anode material. XRD results show that the addition of P123 can restrain the growth of Li2TiO3 during the hydrothermal process, thus affecting the morphology and enhancing the rate performance of the final products. With the addition of P123, the growth of LTO can be restrained and ultrathin LTO nanosheets can be obtained after high temperature sintering, which is beneficial for the charge transfer and Li+ ion diffusion. The rate performance of these two different LTO materials is very different because of their differences in phase composition and fine morphology. The P123-assisted nanostructured LTO sample (P-LTO) shows a much higher rate capability than the LTO sample without P123, with over 130 mAh g-1 capacity retained at the charge-discharge rate of 64C when used in a lithium battery. For intercalation of larger size Na+ ions, the P-LTO still exhibit a capacity of 115 mAh g-1 at a charge (de-sodiation process) rate of 10C and maintains 96% capacity after 400 cycles

  10. ZnO decorated germanium nanoparticles as anode materials in Li-ion batteries

    Science.gov (United States)

    Kim, Tae-Hee; Park, Song Yi; Lee, Tack Ho; Jeong, Jaeki; Kim, Dong Suk; Swihart, Mark T.; Song, Hyun-Kon; Kim, Jin Young; Kim, Seongbeom

    2017-03-01

    Germanium exhibits high charge capacity and high lithium diffusivity, both are the key requirements for electrode materials in high performance lithium ion batteries (LIBs). However, high volume expansion and segregation from the electrode during charge–discharge cycling have limited use of germanium in LIBs. Here, we demonstrate that ZnO decorated Ge nanoparticles (Ge@ZnO NPs) can overcome these limitations of Ge as an LIB anode material. We produced Ge NPs at high rates by laser pyrolysis of GeH4, then coated them with solution phase synthesized ZnO NPs. Half-cell tests revealed dramatically enhanced cycling stability and higher rate capability of Ge@ZnO NPs compared to Ge NPs. Enhancements arise from the core–shell structure of Ge@ZnO NPs as well as production of metallic Zn from the ZnO layer. These findings not only demonstrate a new surface treatment for Ge NPs, but also provide a new opportunity for development of high-rate LIBs.

  11. Fundamental Investigation of Si Anode in Li-Ion Cells

    Science.gov (United States)

    Wu, James J.; Bennett, William R.

    2012-01-01

    Silicon is a promising and attractive anode material to replace graphite for high capacity lithium ion cells since its theoretical capacity is approximately 10 times of graphite and it is an abundant element on earth. However, there are challenges associated with using silicon as Li-ion anode due to the significant first cycle irreversible capacity loss and subsequent rapid capacity fade during cycling. In this paper, cyclic voltammetry and electrochemical impedance spectroscopy are used to build a fundamental understanding of silicon anodes. The results show that it is difficult to form the SEI film on the surface of Si anode during the first cycle, the lithium ion insertion and de-insertion kinetics for Si are sluggish, and the cell internal resistance changes with the state of lithiation after electrochemical cycling. These results are compared with those for extensively studied graphite anodes. The understanding gained from this study will help to design better Si anodes.

  12. Band gap structure modification of amorphous anodic Al oxide film by Ti-alloying

    DEFF Research Database (Denmark)

    Canulescu, Stela; Rechendorff, K.; Borca, C. N.

    2014-01-01

    are not located in a TiO2 unit in the oxide layer, but rather in a mixed Ti-Al oxide layer. The optical band gap energy of the anodic oxide layers was determined by vacuum ultraviolet spectroscopy in the energy range from 4.1 to 9.2 eV (300–135 nm). The results indicate that amorphous anodic Al2O3 has a direct...... band gap of 7.3 eV, which is about ∼1.4 eV lower than its crystalline counterpart (single-crystal Al2O3). Upon Ti-alloying, extra bands appear within the band gap of amorphous Al2O3, mainly caused by Ti 3d orbitals localized at the Ti site....

  13. Low-temperature anodic bonding using thin films of lithium-niobate-phosphate glass

    Science.gov (United States)

    Woetzel, S.; Kessler, E.; Diegel, M.; Schultze, V.; Meyer, H.-G.

    2014-09-01

    This paper reports on the investigation of a low-temperature anodic bonding process with layers of a lithium-niobate-phosphate glass on chip level. The glass layers are deposited by means of rf sputtering. The applied glass is characterised by its high ion conductivity, enabling anodic bonding at room temperature. Results of the optimisation process concerning the intrinsic stress of the glass layers and the thermal exposure of the substrates through the deposition process are presented. The stoichiometry of the glass layers is verified through Rutherford backscattering spectroscopy (RBS). The bonding strength is measured by tensile tests. Microfabricated atomic vapour cells are used for hermeticity tests of the bonding by absorption measurements of the caesium D1 line.

  14. Use of anodic oxide films to control the diffusion of zinc in GaAs

    Science.gov (United States)

    Cutlerywala, H.; Roedel, R. J.

    1994-06-01

    Experiments were performed to diffuse zinc into GaAs through anodic oxide layers of varying thickness and density. Using electrochemical profiling to determine both the electrically active zinc concentration and the diffusion depth with high resolution, the following results were found. The depth of the junction varies inversely with the thickness and the density of the oxide. However, the surface concentration appears to be independent of oxide thickness or density, attaining a value identical to that found for diffusion into a bare GaAs sample. These results demonstrate that the most significant impact of the oxide is to delay the introduction of the zinc into the GaAs lattice. In short, the anodic oxide cannot be used as either a mask or as a zinc concentration attenuator.

  15. Influence of Nanowire Diameter on Structural and Optical Properties of cu Nanowire Synthesized in Anodic Aluminium Oxide Film

    Science.gov (United States)

    Cetinel, A.; Özcelik, Z.

    2016-11-01

    Copper (Cu) nanowire arrays embedded in anodic aluminium oxide films (AAO) on aluminium substrate have been synthesized by alternating current electrochemical deposition. Two-step anodization process has been performed to get the through-hole AAO with ordered nanochannels in 0.3M oxalic acids at DC voltages 30, 40, 50 and 60V, respectively. Structural characterization of the Cu nanowires has been analyzed by scanning electron microscopy (SEM) and X-ray diffraction (or) X-ray diffractometer (XRD). Our SEM analysis has revealed that the diameters of vertically oriented Cu nanowires are 15, 25, 45 and 60nm and the length of Cu nanowires having high packing density is about 15μm. XRD measurement has indicated that polycrystalline Cu nanowires prefer growth orientation along the (111) direction. Optical measurements show that reflection of the Cu nanowires/AAO on aluminium reduces with decreasing diameter of the Cu nanowires. This effect can be associated with increased light scattering from metal nanoparticles near their localized plasmon resonance frequency depending on the size and shape of the nanoparticles.

  16. Centrifugally-spun carbon microfibers and porous carbon microfibers as anode materials for sodium-ion batteries

    Science.gov (United States)

    Dirican, Mahmut; Zhang, Xiangwu

    2016-09-01

    Natural abundance and low cost of sodium resources bring forward the sodium-ion batteries as a promising alternative to widely-used lithium-ion batteries. However, insufficient energy density and low cycling stability of current sodium-ion batteries hinder their practical use for next-generation smart power grid and stationary storage applications. Electrospun carbon microfibers have recently been introduced as a high-performance anode material for sodium-ion batteries. However, electrospinning is not feasible for mass production of carbon microfibers due to its complex processing condition, low production rate and high cost. Herein, we report centrifugal spinning, a high-rate and low-cost microfiber production method, as an alternative approach to electrospinning for carbon microfiber production and introduce centrifugally-spun carbon microfibers (CMFs) and porous carbon microfibers (PCMFs) as anode materials for sodium-ion batteries. Electrochemical performance results indicated that the highly porous nature of centrifugally-spun PCMFs led to increased Na+ storage capacity and improved cycling stability. The reversible capacity of centrifugally-spun PCMF anodes at the 200th cycle was 242 mAh g-1, which was much higher than that of centrifugally-spun CMFs (143 mAh g-1). The capacity retention and coulombic efficiency of the centrifugally-spun PCMF anodes were 89.0% and 99.9%, respectively, even at the 200th cycle.

  17. Controllable fabrication of nanowire-like CuO film by anodization and its properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yongqian, E-mail: cugwyq@126.com [Faculty of Material Science and Chemistry, China University of Geoscience, Wuhan 430074 (China); Jiang, Tingting; Meng, Dawei; Jin, Hongyun [Faculty of Material Science and Chemistry, China University of Geoscience, Wuhan 430074 (China); Yu, Meihua [Guangxi Experiment Centre of Science and Technology, Nanning 530004 (China)

    2015-09-15

    Graphical abstract: - Highlights: • The average diameter of single nanowire is only 25 nm and the length can be tuned. • The method has the advantages of pure CuO phase and fast reaction rate. • H{sub 2}O–EtOH mix solvent can significantly improve optical and photocatalytic activities. • Clarify the growth process in detail. - Abstract: We report a simple electrochemical etching and a subsequent heat treatment to synthesize nanowire-like CuO thin films with pure phase at room temperature. The reaction media has great effect on microstructure of products to significantly improve optical and photocatalytic activities of materials. Detailed characterizations of the synthesized nanomaterials are performed utilizing X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) to study their crystalline phase and morphology. The photoluminescence (PL) spectrum shows a main emission peak and a blue emission band whose centers are located at 352 nm and 463 nm, respectively. Photocatalytic study demonstrated the degradation of methylene blue (MB) can reach 95.6% after 210 min irradiation, showing its potential application in waste water treatment. A plausible growth mechanism for the transformation is also proposed.

  18. Determination of Antimony (III) in Real Samples by Anodic Stripping Voltammetry Using a Mercury Film Screen-Printed Electrode.

    Science.gov (United States)

    Domínguez-Renedo, Olga; Gómez González, M Jesús; Arcos-Martínez, M Julia

    2009-01-01

    This paper describes a procedure for the determination of antimony (III) by differential pulse anodic stripping voltammetry using a mercury film screen-printed electrode as the working electrode. The procedure has been optimized using experimental design methodology. Under these conditions, in terms of Residual Standard Deviation (RSD), the repeatability (3.81 %) and the reproducibility (5.07 %) of the constructed electrodes were both analyzed. The detection limit for Sb (III) was calculated at a value of 1.27×10(-8) M. The linear range obtained was between 0.99 × 10(-8) - 8.26 × 10(-8) M. An analysis of possible effects due to the presence of foreign ions in the solution was performed and the procedure was successfully applied to the determination of antimony levels in pharmaceutical preparations and sea water samples.

  19. Semiconducting behavior of the anodically passive films formed on AZ31B alloy

    OpenAIRE

    A. Fattah-alhosseini; M. Sabaghi Joni

    2014-01-01

    This work includes determination of the semiconductor character and estimation of the dopant levels in the passive film formed on AZ31B alloy in 0.01 M NaOH, as well as the estimation of the passive film thickness as a function of the film formation potential. Mott–Schottky analysis revealed that the passive films displayed n-type semiconductive characteristics, where the oxygen vacancies and interstitials preponderated. Based on the Mott–Schottky analysis, it was shown that the calculated do...

  20. Interweaved Si@C/CNTs and CNFs composites as anode materials for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Miao [School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Hou, Xianhua, E-mail: houxh@scnu.edu.cn [School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Engineering Research Center of Materials and Technology for Electrochemical Energy Storage Ministry of Education, Guangzhou 510006 (China); Wang, Jie; Li, Min [School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Hu, Shejun [School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Engineering Research Center of Materials and Technology for Electrochemical Energy Storage Ministry of Education, Guangzhou 510006 (China); Shao, Zongping [Nanjing University of Technology, College of Chemistry and Chemical Engineering, Nanjing 210009 (China); Liu, Xiang [Institute of Advanced Materials, Nanjing University of Technology, Nanjing 210009 (China)

    2014-03-05

    Graphical abstract: In summary, a serious of high-energy wet ball milling, closed spray drying and subsequent chemical vapor deposition methods were introduced successfully to fabricated novel Si@C/CNTs and CNFs composites with carbon nanotubes and carbon nanofibres interweaved with carbon coated silicon spherical composites as superior anodes in lithium-ion batteries. The core-shell structure of Si@C composites can accommodate the volume change of electrode during charge and discharge. Meanwhile, the citric acid pyrolyzed carbon was coated on the surface of the silicon perfectly and constructs the connection network of nano silicon particles. Moreover, the carbon nanotubes and carbon nanofibres, which is interweaved with nano-silicon, also allows high electrical conductivity, improved solid–electrolyte interface formation and structural integrity. Compared with pure silicon and Si@C composites, the novel Si@C/CNTs and CNFs composites had the best combination of reversible capacity and cycleablity, and this anode materials exhibited excellent electrochemical performance. The Si/C composite had a fairly high initial discharge capacity of 2168.7 mA h g{sup −1} with an efficiency of 73%, and the discharge capacity of the 50th cycle maintained surprisingly of 1194.9 mA h g{sup −1}. Meanwhile, spray drying and chemical vapor deposition are environmentally friendly, economical, and relatively high-yield method for the production of the Si@C/CNTs and CNFs composites in large quantities. Consequently, the novel Si@C/CNTs and CNFs composite electrodes may be a potential alternative to graphite for high energy density lithium ion batteries. Highlights: • The core/shell structured silicon/carbon composites were prepared by a facile way. • The as-prepared Si@C/CNTs and CNFs composites shows excellent electrochemical performance. • The preparation method has mild experiment conditions and high production rate. • The structure benefited electronic transfer and

  1. Synthesis and electrochemical properties of stannous oxide clinopinacoid as anode material for lithium ion batteries.

    Science.gov (United States)

    Iqbal, M Zubair; Wang, Fengping; Rafique, M Yasir; Ali, Shujaat; Din, Rafi Ud; Farooq, M Hassan; Khan, Matiullah; Ali, Murad

    2013-03-01

    Tin monoxide is a significant functional semiconductor material which employed to a wide area of applications especially optical and energy storage devices. Presently, template free hydrothermal technique has been employing to synthesize stannous oxide (SnO) clinopinacoid type controlled morphology using SnCl2 x 2H2O, NH3, and H2O as raw materials. The crystalline phase, morphology, particle size and component were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and field-emission scanning electron microscopy (FESEM). FESEM results exhibited the large scale homogeneous growth of clinopinacoid architecture with the obvious size of 5 - 7 micrometers. The XRD results showed that the average crystallite size of the tetragonal phase romarchite SnO was about 29 nm calculated from the FWHM of X-ray diffraction pattern. The dominant Raman active modes A(1g) = 205 cm(-1), B(1g) = 105-107 cm(-1) and about 6 cm(-1) redshift were observed by the Raman spectroscopy, which further confirmed the existence of the nano tetragonal phase SnO. The electrochemical performance of as-synthesized SnO clinopinacoid structure as the anode material for lithium ion batteries was investigated. It was observed that the first discharge capacity of the two samples could reach a very high value of 1502 mA h g(-1) and 1422 mA h g(-1) respectively. The effect of nitrogen concentration on morphology as well as cyclic performance of Li-Ion-batteries was also discussed.

  2. Structural and defect chemistry guidelines for Sr(V,Nb)O3-based SOFC anode materials.

    Science.gov (United States)

    Macías, J; Yaremchenko, A A; Fagg, D P; Frade, J R

    2015-04-28

    Structural and defect chemistry guidelines were used for Nb-substituted SrVO3-δ materials, designed to meet SOFC anode requirements, with emphasis on redox tolerance, thermochemical compatibility with other SOFC materials, electrical conductivity and adjustable changes in oxygen stoichiometry for their prospective impact on electrocatalytic performance. SrV1-xNbxO3-δ (x = 0-0.30) ceramics were prepared by solid-state synthesis and sintered at 1773 K in a reducing atmosphere. XRD and SEM/EDS showed that under these conditions a single-phase cubic perovskite structure appears up to x ≈ 0.25. Electrical conductivity is metallic-like and nearly p(O2)-independent. Although substitution by niobium decreases the conductivity, which still exceeds 100 S cm(-1) for x ≤ 0.20 at temperatures below 1273 K, it also expands the stability domain of the cubic perovskite phase and suppresses partly high thermochemical expansion characteristic of parent SrVO3-δ. The upper p(O2) limit of phase stability was found to shift from ∼2 × 10(-15) atm for the undoped material to ∼2 × 10(-12) atm for x = 0.30, whereas the average thermal expansion coefficient at 773-1223 K decreased from 22.7 × 10(-6) to 13.3 × 10(-6) K(-1). SrV1-xNbxO3-δ perovskites undergo oxidative decomposition in air, which causes dimensional and microstructural changes. However, sluggish kinetics of oxidation under inert gas conditions results in nearly reversible behavior in relatively short-term redox cycles between reducing and inert atmospheres. Subtle structural changes and a close correlation with point defect chemistry clarify these sluggish changes and provide guidelines to retain the metastability.

  3. Laser annealing of textured thin film cathode material for lithium ion batteries

    Science.gov (United States)

    Kohler, R.; Bruns, M.; Smyrek, P.; Ulrich, S.; Przybylski, M.; Pfleging, W.

    2010-02-01

    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. Lithium cobalt oxide (LiCoO2) is commonly used as a cathode material. Thin films of this electrode material were synthesized by non-reactive r.f. magnetron sputtering of LiCoO2 targets on silicon or stainless steel substrates. For the formation of the high temperature phase of LiCoO2 (HT-LiCoO2), which exhibits good electrochemical performance with a specific capacity of 140 mAh/g and high capacity retention, a subsequent annealing treatment is necessary. For this purpose laser annealing of thin film LiCoO2 was investigated in detail and compared to conventional furnace annealing. A high power diode laser system operating at a wavelength of 940 nm with an integrated pyrometer for temperature control was used. Different temperatures (between 200°C and 700°C) for the laser structured and unstructured thin films were applied. The effects of laser treatment on the LiCoO2 thin films studied with Raman spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction to determine their stoichiometry and crystallinity. The development of HT-LiCoO2 and also the formation of a Co3O4 phase were discussed. The electrochemical properties of the manufactured films were investigated via electrochemical cycling against a lithium anode.

  4. Gallium phosphide as a new material for anodically bonded atomic sensors

    Directory of Open Access Journals (Sweden)

    Nezih Dural

    2014-08-01

    Full Text Available Miniaturized atomic sensors are often fabricated using anodic bonding of silicon and borosilicate glass. Here we describe a technique for fabricating anodically bonded alkali-metal cells using GaP and Pyrex. GaP is a non-birefringent semiconductor that is transparent at alkali-metal resonance wavelengths, allowing new sensor geometries. GaP also has a higher thermal conductivity and lower He permeability than borosilicate glass and can be anodically bonded below 200 °C, which can also be advantageous in other vacuum sealing applications.

  5. Gallium phosphide as a new material for anodically bonded atomic sensors

    Energy Technology Data Exchange (ETDEWEB)

    Dural, Nezih; Romalis, Michael V., E-mail: romalis@princeton.edu [Physics Department, Princeton University, Princeton, New Jersey 08540 (United States)

    2014-08-01

    Miniaturized atomic sensors are often fabricated using anodic bonding of silicon and borosilicate glass. Here we describe a technique for fabricating anodically bonded alkali-metal cells using GaP and Pyrex. GaP is a non-birefringent semiconductor that is transparent at alkali-metal resonance wavelengths, allowing new sensor geometries. GaP also has a higher thermal conductivity and lower He permeability than borosilicate glass and can be anodically bonded below 200 °C, which can also be advantageous in other vacuum sealing applications.

  6. Gallium phosphide as a new material for anodically bonded atomic sensors

    Science.gov (United States)

    Dural, Nezih; Romalis, Michael V.

    2014-08-01

    Miniaturized atomic sensors are often fabricated using anodic bonding of silicon and borosilicate glass. Here we describe a technique for fabricating anodically bonded alkali-metal cells using GaP and Pyrex. GaP is a non-birefringent semiconductor that is transparent at alkali-metal resonance wavelengths, allowing new sensor geometries. GaP also has a higher thermal conductivity and lower He permeability than borosilicate glass and can be anodically bonded below 200 °C, which can also be advantageous in other vacuum sealing applications.

  7. Self-Organizing Evolution of Anodized Oxide Films on Ti-25Nb-3Mo-2Sn-3Zr Alloy and Hydrophilicity

    Institute of Scientific and Technical Information of China (English)

    何芳; 李立军; 陈利霞; 李凤娇; 黄远

    2014-01-01

    In the present work, hierarchical nanostructured titanium dioxide (TiO2) films were fabricated on Ti-25Nb-3Mo-2Sn-3Zr (TLM) alloy for biomedical applications via one-step anodization process in ethylene glycol-based electrolyte containing 0.5wt%NH4F. The nanostructured TiO2 films exhibited three distinct types depending on the anodization time:top irregular nanopores (INP)/beneath regular nanopores (RNP), top INP/middle regular nano-tubes (RNT)/bottom RNP and top RNT with underlying RNP. The evolution of the nanostructured TiO2 films with anodization time demonstrated that self-organizing nanopores formed at the very beginning and individual nanotubes originated from underlying nanopore dissolution. Furthermore, a modified two-stage self-organizing mechanism was introduced to illustrate the growth of the nanostructured TiO2 films. Compared with TLM titanium alloy matrix, the TiO2 films with special nano-structure hold better hydrophilicity and higher specific surface area, which lays the foun-dation for their biomedical applications.

  8. Electrochemical performance of La-Co-Sn alloys as anode materials for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wang, G.; Gao, X.P. [Institute of New Energy Material Chemistry, Nankai University, Tianjin 300071 (China); Lu, Z.W. [Institute of New Energy Material Chemistry, Nankai University, Tianjin 300071 (China); Tianjin Institute of Power Sources, Tianjin 300381 (China); Liu, X.J.; Wang, J.Q. [Tianjin Institute of Power Sources, Tianjin 300381 (China)

    2009-04-01

    Sn-rich La-Co-Sn ternary alloys were obtained by arc-melting process and subsequent ball-milling. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to determine the structure and morphology of the obtained alloys. In addition, the galvanostatic discharge/charge test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were carried out to characterize the electrochemical properties of these alloys as anode materials for Li-ion batteries. It is found that all the as-cast La-Co-Sn ternary alloys have the same main phase of La{sub 3}Co{sub 4}Sn{sub 13} and low electrochemical capacities. Among these alloys, the as-cast LaCoSn{sub 4} alloy exhibits the best electrochemical performance. The ball-milling process results in the reduced cystallinity, and the enhanced electrochemical capacities as compared to the as-cast alloy. In particular, the LaCoSn{sub 4} alloy, obtained after ball-milling for 16 h, provides the higher reversible discharge capacity and the better cycle stability. (author)

  9. Ordered CoO/CMK-3 nanocomposites as the anode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Haijiao; Jiao, Zheng [Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 200444 (China); Shanghai Applied Radiation Institute, School of Environmental and Chemical Engineering, Shanghai University, Shangda Road 99, Shanghai 200444 (China); Tao, Haihua; Jiang, Yong; Wu, Minghong; Zhao, Bing [Shanghai Applied Radiation Institute, School of Environmental and Chemical Engineering, Shanghai University, Shangda Road 99, Shanghai 200444 (China)

    2010-05-01

    A novel ordered mesoporous carbon hybrid composite, CoO/CMK-3, is prepared by an infusing method using Co(NO{sub 3}){sub 2}.6H{sub 2}O as the cobalt source. The products are characterized by X-ray diffraction, transmission electron microscopy and N{sub 2} adsorption-desorption analysis techniques. It is observed that the CoO nanoparticles are loaded in the channels of mesoporous carbon. The mesopore structure of CMK-3 is destroyed gradually with increasing of the CoO content. The electrochemical properties of samples as the anode materials for lithium-ion batteries are studied by galvanostatic method. The results show that the CoO/CMK-3 composites have higher reversible capacities (more than 700 mAh g{sup -1}) and better cycle performance in comparison with the pure mesoporous carbon (CMK-3). Based on the above results, a mechanism is proposed to explain the reason of such a substantial improvement of electrochemical performance in the CoO/CMK-3 composites. (author)

  10. Novel synthesis of tin oxide/graphene aerogel nanocomposites as anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zheyu [College of Material Science and Engineering, Liaoning Technical University, Fuxin 123000 (China); Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Li, Xifei, E-mail: xfli2011@hotmail.com [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Tai, Limin, E-mail: tailimin@163.com [College of Material Science and Engineering, Liaoning Technical University, Fuxin 123000 (China); Song, Haoze; Zhang, Yiyan; Yan, Bo; Fan, Linlin; Shan, Hui [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Li, Dejun, E-mail: dli1961@126.com [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China)

    2015-10-15

    A novel method of mechanical exfoliation followed by hydrothermal approach was proposed to synthesize the tin oxide/graphene aerogels (SnO{sub 2}/GAs) nanocomposites. Homogeneous distribution of SnO{sub 2} nanocrystals on GAs was confirmed by SEM, XRD and TEM characterization. It was found that optimized exfoliation of the SnS{sub 2} is the key factor to obtain high electrochemical lithiation/delithiation performance of the anodes. The as-prepared SnO{sub 2}/GA nanocomposites exhibited high reversible capacity (up to 1086.7 mAh g{sup −1} after 100 cycles) and excellent cycling stability. The improved rate capability was also obtained, for instance, the reversible capacity at a current density of 800 mA g{sup −1} is over 447.9 mAh g{sup −1}, and then recovered to as high as 784.4 mAh g{sup −1} at a current density of 100 mA g{sup −1}. - Highlights: • A novel approach was employed to synthesize the SnO{sub 2}/GA nanocomposites. • The designed SnO{sub 2}/GAs exhibited high reversible capacity and excellent cycling stability. • The volume change challenge of SnO{sub 2} was markedly alleviated by the GA matrix. • The novel synthesis method can be extended for other materials in lithium ion batteries.

  11. Electrochemical performance of polygonized carbon nanofibers as anode materials for lithium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    Jinjin Jiang; xiaolin Tang; Rui Wu; Haoqiang Lin; Meizhen Qu

    2013-01-01

    Carbon nanofibers with a polygonal cross section (P-CNFs) synthesized using a catalytic chemical vapor deposition (CCVD) technology have been investigated for potential applications in lithium batteries as anode materials.P-CNFs exhibit excellent high-rate capabilities.At a current density as high as 3.7 and 7.4A/g,P-CNFs can still deliver a reversible capacity of 198.4 and 158.2 mAh/g,respectively.To improve their first coulombic efficiency,carbon-coated P-CNFs were prepared through thermal vapor deposition (TVD) of benzene at 900 ℃.The electrochemical results demonstrate that appropriate amount of carbon coating can improve the first coulombic efficiency,the cycling stability and the rate performance of P-CNFs.After carbon coating,P-CNFs gain a weight increase approximately by 103 wt%,with its first coulombic efficiency increasing from 63.1 to 78.4%,and deliver a reversible capacity of 197.4mAh/g at a current density of 3.7 A/g.After dozens of cycles,there is no significant capacity degradation at both low and high current densities.

  12. Various Structured Molybdenum-based Nanomaterials as Advanced Anode Materials for Lithium ion Batteries.

    Science.gov (United States)

    Wu, Zexing; Lei, Wen; Wang, Jie; Liu, Rong; Xia, Kedong; Xuan, Cuijuan; Wang, Deli

    2017-04-12

    A facile and scalable solvothermal high-temperature treatment strategy was developed to construct few-layered ultrasmall MoS2 with less than three layers. These are embedded in carbon spheres (MoS2-C) and can be used as advanced anode material for lithium ion batteries (LIBs). In the resulting architecture, the intimate contact between MoS2 surface and carbon spheres can effectively avert aggregation and volume expansion of MoS2 during the lithiation-delithiation process. Moreover, it improves the structural integrity of the electrode remarkably, while the conductive carbon spheres provide quick transport of both electrons and ions within the electrode. Benefiting from this unique structure, the resulting hybrid manifests outstanding electrochemical performance, including an excellent rate capability (1085, 885, and 510 mAh g(-1) at 0.5, 2, and 5 A g(-1)), and a superior cycling stability at high rates (maintaining 100% of the initial capacity following 500 cycles at 0.5 A g(-1)). Using identical methods, molybdenum carbide and phosphide supported on carbon spheres (Mo2C-C, and MoP-C) were prepared for LIBs. As a result, MoS2-C exhibits outstanding lithium storage capacities due to its specific layered structure. This study investigates large-scale production capabilities of few-layered structure ultrasmall MoS2 for energy storage, and thoroughly compares lithium storage performance of molybdenum compounds.

  13. The formation of micrometer-long TiO2 nanotube arrays by anodization of titanium film on conducting glass substrate

    Science.gov (United States)

    Tang, Yuxin; Tao, Jie; Dong, Zhili; Tien Oh, Joo; Chen, Zhong

    2011-12-01

    Micrometer-long titanium oxide nanotube arrays, tens of nanometers in diameter, were fabricated by anodization of titanium film coated on a conducting glass substrate. The Ti film was deposited by magnetron sputtering at room temperature. The effect of anodizing conditions on the formation of TiO2 nanotubes was investigated. The results indicate that dense and uniform Ti film deposited under 150 W at room temperature was favorable for the formation of ordered nanotube arrays. The average diameter of the TiO2 nanotubes varied from 35 to 95 nm when the anodization potential changed from 10 to 40 V. Micrometer-long nanotubes (1.1 μm) with good adhesion to the substrate could be obtained in 0.5 wt% NH4F/glycerol at 30 V for 2 h. After heat treatment, the crystalline anatase nanotubes show enhanced photoelectrochemical activity compared with those anodized in 1 M H3PO4/0.5 wt% HF. This is attributed to the increased light-harvesting abilities.

  14. One-step hydrothermal preparation of TiO{sub 2}/WO{sub 3} nanocomposite films on anodized stainless steel for photocatalytic degradation of organic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Zhan, W.T. [Key Laboratory for Ferrous Metallurgy and Resource Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081 (China); Ni, H.W., E-mail: nihongwei@wust.edu.cn [Key Laboratory for Ferrous Metallurgy and Resource Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081 (China); Chen, R.S.; Wang, Z.Y. [Key Laboratory for Ferrous Metallurgy and Resource Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081 (China); Li, Y.W; Li, J.H. [Yangjiang SHIBAZI Group, Yangjiang 529500 (China)

    2013-12-02

    TiO{sub 2}/WO{sub 3} nanocomposite film was deposited on anodized stainless steel by one step hydrothermal reaction. Polished stainless steel foil was anodized to form nanopore arrays on the surface that is favorable for the immobilization of photocatalyst. The TiO{sub 2}/WO{sub 3} nanocomposite film prepared in 0.01 mol/L (NH{sub 4}){sub 2}TiF{sub 6} and 0.0066 mol/L Na{sub 2}WO{sub 4} solution at 120 °C for 3 h exhibits the maximum photocatalytic activity, which is five times higher than that of pure TiO{sub 2} film and eight times higher than that of pure WO{sub 3} film. As compared with the pure TiO{sub 2} film, the main absorption edge of the WO{sub 3}/TiO{sub 2} nanocomposite film shifts toward visible region and the absorption intensity is obviously improved. The nanocomposite film has a preferable crystallinity of anatase TiO{sub 2} and the monoclinic WO{sub 3}, as revealed by X-ray diffraction and X-ray photoelectron spectroscopy. Scanning electron microscopy images show that the nanocomposite film is homogenous in size distribution and uniform in morphology. The high resolution transmission electron microscopy images further demonstrate the formation of mixed crystal between WO{sub 3} and TiO{sub 2} nanoparticles. The excellent photocatalytic activity of the nanocomposite film should be attributed to the formation of heterojunction between TiO{sub 2} and WO{sub 3} nanoparticles that can facilitate the separation of photo-generated electron–hole pairs. - Highlights: • TiO{sub 2}/WO{sub 3} nanocomposite film on anodized stainless steel by hydrothermal deposition • The anodized stainless steel offered a favorable substrate to immobilize the photocatalyst. • The photocatalytic activity of TiO{sub 2}/WO{sub 3} film is significantly higher than that of TiO{sub 2} film. • The heterojunction between TiO{sub 2} and WO{sub 3} leads to excellent photocatalytic activity.

  15. Ternary CNTs@TiO2/CoO Nanotube Composites: Improved Anode Materials for High Performance Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Mahmoud Madian

    2017-06-01

    Full Text Available TiO2 nanotubes (NTs synthesized by electrochemical anodization are discussed as very promising anodes for lithium ion batteries, owing to their high structural stability, high surface area, safety, and low production cost. However, their poor electronic conductivity and low Li+ ion diffusivity are the main drawbacks that prevent them from achieving high electrochemical performance. Herein, we report the fabrication of a novel ternary carbon nanotubes (CNTs@TiO2/CoO nanotubes composite by a two-step synthesis method. The preparation includes an initial anodic fabrication of well-ordered TiO2/CoO NTs from a Ti-Co alloy, followed by growing of CNTs horizontally on the top of the oxide films using a simple spray pyrolysis technique. The unique 1D structure of such a hybrid nanostructure with the inclusion of CNTs demonstrates significantly enhanced areal capacity and rate performances compared to pure TiO2 and TiO2/CoO NTs, without CNTs tested under identical conditions. The findings reveal that CNTs provide a highly conductive network that improves Li+ ion diffusivity, promoting a strongly favored lithium insertion into the TiO2/CoO NT framework, and hence resulting in high capacity and an extremely reproducible high rate capability.

  16. Ternary CNTs@TiO₂/CoO Nanotube Composites: Improved Anode Materials for High Performance Lithium Ion Batteries.

    Science.gov (United States)

    Madian, Mahmoud; Ummethala, Raghunandan; Naga, Ahmed Osama Abo El; Ismail, Nahla; Rümmeli, Mark Hermann; Eychmüller, Alexander; Giebeler, Lars

    2017-06-20

    TiO₂ nanotubes (NTs) synthesized by electrochemical anodization are discussed as very promising anodes for lithium ion batteries, owing to their high structural stability, high surface area, safety, and low production cost. However, their poor electronic conductivity and low Li⁺ ion diffusivity are the main drawbacks that prevent them from achieving high electrochemical performance. Herein, we report the fabrication of a novel ternary carbon nanotubes (CNTs)@TiO₂/CoO nanotubes composite by a two-step synthesis method. The preparation includes an initial anodic fabrication of well-ordered TiO₂/CoO NTs from a Ti-Co alloy, followed by growing of CNTs horizontally on the top of the oxide films using a simple spray pyrolysis technique. The unique 1D structure of such a hybrid nanostructure with the inclusion of CNTs demonstrates significantly enhanced areal capacity and rate performances compared to pure TiO₂ and TiO₂/CoO NTs, without CNTs tested under identical conditions. The findings reveal that CNTs provide a highly conductive network that improves Li⁺ ion diffusivity, promoting a strongly favored lithium insertion into the TiO₂/CoO NT framework, and hence resulting in high capacity and an extremely reproducible high rate capability.

  17. Disordered 3 D Multi-layer Graphene Anode Material from CO2 for Sodium-Ion Batteries.

    Science.gov (United States)

    Smith, Kassiopeia; Parrish, Riley; Wei, Wei; Liu, Yuzi; Li, Tao; Hu, Yun Hang; Xiong, Hui

    2016-06-22

    We report the application of disordered 3 D multi-layer graphene, synthesized directly from CO2 gas through a reaction with Li at 550 °C, as an anode for Na-ion batteries (SIBs) toward a sustainable and greener future. The material exhibited a reversible capacity of ∼190 mA h g(-1) with a Coulombic efficiency of 98.5 % at a current density of 15 mA g(-1) . The discharge capacity at higher potentials (>0.2 V vs. Na/Na(+) ) is ascribed to Na-ion adsorption at defect sites, whereas the capacity at low potentials (CO2 gas makes it attractive not only as an anode material for SIBs but also to mitigate CO2 emission.

  18. Spongelike Nanosized Mn 3 O 4 as a High-Capacity Anode Material for Rechargeable Lithium Batteries

    KAUST Repository

    Gao, Jie

    2011-07-12

    Mn3O4 has been investigated as a high-capacity anode material for rechargeable lithium ion batteries. Spongelike nanosized Mn 3O4 was synthesized by a simple precipitation method and characterized by powder X-ray diffraction, Raman scattering and scanning electron microscopy. Its electrochemical performance, as an anode material, was evaluated by galvanostatic discharge-charge tests. The results indicate that this novel type of nanosized Mn3O4 exhibits a high initial reversible capacity (869 mA h/g) and significantly enhanced first Coulomb efficiency with a stabilized reversible capacity of around 800 mA h/g after over 40 charge/discharge cycles. © 2011 American Chemical Society.

  19. Graphene-Oxide-Assisted Synthesis of GaN Nanosheets as a New Anode Material for Lithium-Ion Battery.

    Science.gov (United States)

    Sun, Changlong; Yang, Mingzhi; Wang, Tailin; Shao, Yongliang; Wu, Yongzhong; Hao, Xiaopeng

    2017-08-16

    As the most-studied III-nitride, theoretical researches have predicted the presence of gallium nitride (GaN) nanosheets (NSs). Herein, a facile synthesis approach is reported to prepare GaN NSs using graphene oxide (GO) as sacrificial template. As a new anode material of Li-ion battery (LIBs), GaN NSs anodes deliver the reversible discharge capacity above 600 mA h g(-1) at 1.0 A g(-1) after 1000 cycles, and excellent rate performance at current rates from 0.1 to 10 A g(-1). These results not only extend the family of 2D materials but also facilitate their use in energy storage and other applications.

  20. Remarkable cycle-activated capacity increasing in onion-like carbon nanospheres as lithium battery anode material

    Science.gov (United States)

    Dong, Jiajun; Zhang, Tong; Zhang, Dong; Zhang, Weiwei; Zhang, Huafang; Liu, Ran; Yao, Mingguang; Liu, Bingbing

    2017-01-01

    Onion-like carbon nanospheres (OCNSs) with an average diameter of 43 nm were produced on a large scale via a combustion method and examined as an anode material for lithium ion batteries. The OCNSs exhibit a remarkable electrochemical cycling behavior and a capacity much higher than that of graphite. The capacity increases significantly with increasing charge-discharge cycles and reaches a value of 178% of the initial value (from 586 mA h g-1to 1045 mA h g-1) after 200 cycles. Further investigation provides unambiguous experimental evidence that such a remarkable capacity increase is related to the stable onion-like structure of the OCNSs and to the existence of large numbers of disordered/short graphitic fragments, which gradually provide more active sites for Li ion storage. The unique electrochemical performance of OCNSs provides a new way to design a high-performance anode material for rechargeable batteries.

  1. Fabrication of bristlegrass-like VO2 (B)-ZnO heteroarchitectures as anode materials for lithium-ion batteries

    Science.gov (United States)

    Ma, Yining; Li, Wenjing; Ji, Shidong; Zhou, Huaijuan; Li, Rong; Li, Ning; Yao, Heliang; Cao, Xun; Jin, Ping

    2017-08-01

    Three-dimensional bristlegrass-like hierarchical VO2 (B)-ZnO heteroarchitectures with ZnO nanorods grown radially on VO2 (B) nanorods were successfully fabricated via a simple two-step synthesized method. When applied as an anode material for lithium-ion batteries, the VO2 (B)-ZnO hybrid electrode exhibited high reversible capacity and excellent recyclability, which could be originated from the unique hierarchical structure of the bristlegrass. After 80 cycles, the nanocomposite still maintained a higher reversible capacity of 329.4 mA h g-1 at a current density of 50 mA g-1. Therefore, the particular architecture of VO2 (B)-ZnO nanocomposite can be a promising candidate as the anode material in lithium-ion batteries.

  2. SnOx Thin Films Deposited by Reactive Magnetron Sputtering for Microbatteries Anodes

    Institute of Scientific and Technical Information of China (English)

    XING Guang-jian; YANG Zhi-min; SHEN Wan; MAO Chang-hui; DU Jun

    2004-01-01

    SnOx thin films, with various oxygen deficiencies, are deposited from a Sn target on to silicon substratesby reactive magnetron sputtering. The SnOx films are characterized by X-ray diffraction ( XRD ) and X-ray photoelectron spectroscopy(XPS). Influences of deposition conditions such as oxygen partial pressure and annealing temperature on the characteristicsof the films are discussed in detail. The high reversible capacity and cycle performance characteristics of SnOxare also described. The results show that stoichiometric parameter x increases with the increase in oxygen partial pressure. The chargedischarge performance of the SnOxfilms is found to be dependent on x value.

  3. CuO/C microspheres as anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Huang, X.H., E-mail: drhuangxh@hotmail.com [Academy of Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); School of Physics and Electronic Engineering, Taizhou University, Taizhou 318000 (China); Wang, C.B.; Zhang, S.Y. [Academy of Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Zhou, F., E-mail: fzhou@nuaa.edu.cn [Academy of Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

    2011-07-30

    Highlights: > CuO/C composite microspheres have been successfully prepared by calcining the CuCl{sub 2}/resorcinol-formaldehyde gel in argon atmosphere followed by a subsequent oxidation treatment using H{sub 2}O{sub 2} solution. > CuO particles disperse homogenously inside the carbon aerogel microspheres. > Carbon aerogel microspheres have the abilities of alleviating the pulverization, suppressing the aggregation, and enhancing the conductivity of the CuO particles. Therefore, CuO/C composite microspheres exhibit better electrochemical performance than that of pure CuO. - Abstract: CuO/C microspheres are prepared by calcining CuCl{sub 2}/resorcinol-formaldehyde (RF) gel in argon atmosphere followed by a subsequent oxidation process using H{sub 2}O{sub 2} solution. The microstructure and morphology of materials are characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and transition electron microscopy (TEM). Carbon microspheres have an average diameter of about 2 {mu}m, and CuO particles with the sizes of 50-200 nm disperse in these microspheres. The electrochemical properties of CuO/C microspheres as anode materials for lithium ion batteries are investigated by galvanostatic discharge-charge and cyclic voltammetry (CV) tests. The results show that CuO/C microspheres deliver discharge and charge capacities of 470 and 440 mAh g{sup -1} after 50 cycles, and they also exhibit better rate capability than that of pure CuO. It is believed that the carbon microspheres play an important role in their electrochemical properties.

  4. 阳极氧化法制备多孔氧化铝膜的形成过程研究%Investigation on the growth sequence of porous anodic aluminum oxide films by two-step anodization

    Institute of Scientific and Technical Information of China (English)

    刘海凤; 路丙强; 梁冬林; 魏水强; 苟凯佩; 王凡; 文衍宣

    2012-01-01

    采用阳极氧化技术,研究了电压对多孔氧化铝膜生长过程的影响.使用扫描电镜( SEM)对在草酸-水-乙醇体系中形成的多孔氧化铝膜形貌进行观测.结果表明,在第二步氧化过程中,在40V氧化电压下,多孔氧化铝膜的有序度和孔径随反应时间延长而降低;在80 V下,经过长时间反应,AAO膜表面腐蚀严重,难以获得平整的多孔结构.预氧化过程所形成的薄氧化层有效保护了多孔氧化铝表面,同时对多孔结构具有短距离诱导作用.改变氧化电压、电解质浓度和反应时间,有序孔排列的结构参数也有所改变.高电场下,孔道的相互作用促进了其生长分化,形成了两种不同的孔道结构.%The detailed growth processes of porous anodic aluminum oxide films influenced by the applied voltage were studied via anodization method. The appearance of the porous anodic aluminum oxide films formed in oxalic acid-water-ethanol solution was studied by SEM. At the second anodization step, the ordering degree and pore size of oxide films decreased at 40 V, while the rough surface of AAO by severe corrosion was obtained at 80 V. Whereas, the surface oxide layer generated by pre-anodization provided effective protection at the early stage of high-voltage anodization, and guided the formation of ordered pores array in short range. The structural parameters of ordered pores array were dependent on the applied voltage, electrolyte concentration and reaction time. At high applied voltage, the cause of interaction forces between neighboring pores enhances the differentiation of pore growth, and hence two different pores growth behaviors in the internal and surface of AAO membrane are observed.

  5. 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

  6. Nano Structure Plays an Important Role in the Present and Future Anode Materials of Li-ion Batteries

    Institute of Scientific and Technical Information of China (English)

    Tsutomu; Takamura

    2007-01-01

    1 ResultsLi-ion batteries are the most promising secondary batteries for IT and EV applications, where it is required to increase the capacity and power capability to a great extent. In responding to the demand we have been studied on the anode materials especially paying attention on the improved graphite active materials and modified silicon. In both cases we realized that the nano-structured design plays an important role. In this paper the examples of nano-size structure working in the actual materi...

  7. Studies on the properties of anodic oxidation film on aluminum alloy%铝合金阳极氧化膜的性能研究

    Institute of Scientific and Technical Information of China (English)

    许旋; 罗一帆; 林国辉

    2001-01-01

    在硫酸电解液中加入适量由羧酸和有机化合物组成的添加剂,制得铝合金阳极氧化膜。研究了温度对所得氧化膜厚度和硬度和影响,并利用扫描电镜观察了氧化膜的结构。结果表明,高温下形成的氧化膜结构松散,厚度和硬度低,而加入添加剂后,氧化膜溶解减慢,在高温下所形成的氧化膜的厚度和硬度大大增加。%Anodic oxidation film was prepared on aluminum alloy in sulfuricacid electrolyte. An additive was developed which consists of carboxylic acids and organic compounds. The effect of temperature on thickness and hardness of the obtained anodic oxidation film was studied, structure of the oxidation film was analyzed by SEM. The results show that oxidation film obtained at high temperature has loose structure. Thickness and hardness of the film decrease with the increase of temperature, while the addition of the additive reduces the dissolution of the oxidation film, and increases film thickness and hardness greatly at high temperature.

  8. Thick and hard anodized aluminum film with large pores for surface composites

    Institute of Scientific and Technical Information of China (English)

    WANG Hui; WANG Hao-wei

    2004-01-01

    Al-base surface self-lubricating composites need thick and hard alumina membranes with large pores to add lubricants easily. This kind of porous alumina layer was fabricated in additive-containing, phosphoric acid-based solution. The effects of additive containing organic carboxylic acid and Ce salt on the properties of the oxide film and mechanism were investigated in detail with SEM and EDAX analyses. The results show that the pore diameter is about 100 nm, the film thickness increases by 4 -5 times, and the Vickers hardness improves by about 50% through adding some amount of organic carboxylic acid and Ce salt. Such an improvement in properties is explained in terms of a lower film dissolving velocity and better film quality in compound solution.

  9. Controlled thermal sintering of a metal-metal oxide-carbon ternary composite with a multi-scale hollow nanostructure for use as an anode material in Li-ion batteries.

    Science.gov (United States)

    Kim, Hwan Jin; Zhang, Kan; Choi, Jae-Man; Song, Min Sang; Park, Jong Hyeok

    2014-03-11

    We report a synthetic scheme for preparing a SnO2-Sn-carbon triad inverse opal porous material using the controlled sintering of Sn precursor-infiltrated polystyrene (PS) nanobead films. Because the uniform PS nanobead film, which can be converted into carbon via a sintering step, uptakes the precursor solution, the carbon can be uniformly distributed throughout the Sn-based anode material. Moreover, the partial carbonization of the PS nanobeads under a controlled Ar/oxygen environment not only produces a composite material with an inverse opal-like porous nanostructure but also converts the Sn precursor/PS into a SnO2-Sn-C triad electrode.

  10. Hybrid phosphorene/graphene nanocomposite as an anode material for Na-ion batteries: a first-principles study

    Science.gov (United States)

    Wang, Linxia; Jiang, Zhiqiang; Li, Wei; Gu, Xiao; Huang, Li

    2017-04-01

    The potential application of the hybrid phosphorene/graphene (P/G) composites as an anode material in Na-ion batteries (NIBs) has been explored based on first-principles calculations. The calculated elastic constants reveal that the P/G has an ultrahigh stiffness, which can effectively suppress the undesirable structural deformation during the sodiation and desodiation cycles. Na atoms can strongly bind with the phosphorene single-layer (SP), double-layer (DP), and their composites with graphene (SP/G, DP/G, G/DP/G), and can even cause a sliding between the layers when the DP/G accommodate more Na atoms. The migration of Na in P/G is anisotropic with the minimum energy path along the zigzag channel. The low diffusion barriers of only about several tens of meV ensure the high mobility of Na within the layers, and thus lead to rapid charge/discharge capacity of P/G. The electronic structures show that the hybrid P/G becomes metallic with the Na incorporation, which contributes to the good electric conductivity in P/G. We further demonstrate that the average open circuit voltage (OCV) of DP/G is 0.53 V, which is comparable to other anode materials. These results suggest that P/G composites hold great potential to be a good anode material in NIBs.

  11. The developments of SnO2/graphene nanocomposites as anode materials for high performance lithium ion batteries: A review

    Science.gov (United States)

    Deng, Yuanfu; Fang, Chengcheng; Chen, Guohua

    2016-02-01

    With the increasing energy demands for electronic devices and electrical vehicles, anode materials for lithium ion batteries (LIBs) with high specific capacity, good cyclic and rate performances become one of the focal areas of research. Among the various anode materials, SnO2/graphene nanocomposites have drawn extensive attentions due to their high theoretical specific capacities, low charge potential vs. Li/Li+ and environmental benignity. In this review, the advances, including the synthetic methods and structural optimizations, of the SnO2/graphene nanocomposites as anode materials for LIBs have been reviewed in detail. By providing an in-depth discussion of SnO2/graphene nanocomposites, we aim to demonstrate that the electrochemical performances of SnO2/graphene nanocomposites could be significantly enhanced by rational modifications of morphology and crystal structures, chemical compositions and surface features. Though only focusing on SnO2/graphene-based composites, the concepts and strategies should be referential to other metal oxide/graphene composites.

  12. Lithium Germanate (Li2 GeO3 ): A High-Performance Anode Material for Lithium-Ion Batteries.

    Science.gov (United States)

    Rahman, Md Mokhlesur; Sultana, Irin; Yang, Tianyu; Chen, Zhiqiang; Sharma, Neeraj; Glushenkov, Alexey M; Chen, Ying

    2016-12-23

    A simple, cost-effective, and easily scalable molten salt method for the preparation of Li2 GeO3 as a new type of high-performance anode for lithium-ion batteries is reported. The Li2 GeO3 exhibits a unique porous architecture consisting of micrometer-sized clusters (secondary particles) composed of numerous nanoparticles (primary particles) and can be used directly without further carbon coating which is a common exercise for most electrode materials. The new anode displays superior cycling stability with a retained charge capacity of 725 mAh g(-1) after 300 cycles at 50 mA g(-1) . The electrode also offers excellent rate capability with a capacity recovery of 810 mAh g(-1) (94 % retention) after 35 cycles of ascending steps of current in the range of 25-800 mA g(-1) and finally back to 25 mA g(-1) . This work emphasizes the importance of exploring new electrode materials without carbon coating as carbon-coated materials demonstrate several drawbacks in full devices. Therefore, this study provides a method and a new type of anode with high reversibility and long cycle stability. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Kinetics of the electrolytic Fe+2/Fe+3 oxidation on various anode materials

    Directory of Open Access Journals (Sweden)

    Cifuentes, L.

    2003-08-01

    Full Text Available The kinetics of the electrolytic Fe+2/Fe+3 oxidation, relevant to hydro-electrometallurgical processing, have been studied on lead, platinum, ruthenium oxide, iridium oxide and graphite anodes in ferrous sulfate-sulfuric acid solutions. The oxidation rate depends on ferrous sulfate concentration, solution temperature and degree of agitation. Potentiodynamic studies show that: a the highest oxidation rate is obtained on platinum; b lead is unsuitable as anodic material for the said reaction; c the remaining anode materials show a similar and satisfactory performance.

    Se ha estudiado la cinética de la oxidación electrolítica Fe+2/Fe+3 -relevante para el procesamiento hidroelectrometalúrgico- sobre plomo, platino, óxido de rutenio, óxido de iridio y grafito en soluciones de sulfato ferroso en ácido sulfúrico. La velocidad de oxidación depende de la concentración de sulfato ferroso, la temperatura de la solución y el grado de agitación. Estudios potenciodinámicos demuestran que: a las mayores velocidades de oxidación se obtienen sobre platino; b el plomo es inadecuado como material anódico para la reacción mencionada; c los materiales anódicos restantes exhiben un desempeño similar y satisfactorio.

  14. Ferrite-based perovskites as cathode materials for anode-supported solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Mai, Andreas; Haanappel, Vincent A.C.; Uhlenbruck, Sven; Tietz, Frank; Stoever, Detlev [Institute for Materials and Processes in Energy Systems, Forschungszentrum Juelich, IWV-1, D-52425 Juelich (Germany)

    2005-05-12

    The properties and the applicability of iron- and cobalt-containing perovskites were evaluated as cathodes for solid oxide fuel cells (SOFCs) in comparison to state-of-the-art manganite-based perovskites. The materials examined were La{sub 1-x-y}Sr{sub x}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (x=0.2 and 0.4; y=0-0.05), La{sub 0.8}Sr{sub 0.2}FeO{sub 3-{delta}}, La{sub 0.7}Ba{sub 0.3}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} and Ce{sub 0.05}Sr{sub 0.95}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}}. The main emphasis was placed on the electrochemical properties of the materials, which were investigated on planar anode-supported SOFCs with 8 mol% yttria-stabilised zirconia (8YSZ) electrolytes. An interlayer of the composition Ce{sub 0.8}Gd{sub 0.2}O{sub 2-{delta}} was placed between the electrolyte and the cathode to prevent undesired chemical reactions between the materials. The sintering temperatures of the cathodes were adapted for each of the materials to obtain similar microstructures. In comparison to the SOFCs with state-of-the-art manganite-based cathodes, SOFCs with La{sub 1-x-y}Sr{sub x}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} cathodes achieved much higher current densities. Small A-site deficiency and high strontium content had a particularly positive effect on cell performance. The measured current densities of cells with these cathodes were as high as 1.76 A/cm{sup 2} at 800 {sup o}C and 0.7 V, which is about twice the current density of cells with LSM/YSZ cathodes. SOFCs with La{sub 0.58}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} cathodes have been operated for more than 5000 h in endurance tests with a degradation of 1.0-1.5% per 1000 h.

  15. High-throughput characterization of film thickness in thin film materials libraries by digital holographic microscopy.

    Science.gov (United States)

    Lai, Yiu Wai; Krause, Michael; Savan, Alan; Thienhaus, Sigurd; Koukourakis, Nektarios; Hofmann, Martin R; Ludwig, Alfred

    2011-10-01

    A high-throughput characterization technique based on digital holography for mapping film thickness in thin-film materials libraries was developed. Digital holographic microscopy is used for fully automatic measurements of the thickness of patterned films with nanometer resolution. The method has several significant advantages over conventional stylus profilometry: it is contactless and fast, substrate bending is compensated, and the experimental setup is simple. Patterned films prepared by different combinatorial thin-film approaches were characterized to investigate and demonstrate this method. The results show that this technique is valuable for the quick, reliable and high-throughput determination of the film thickness distribution in combinatorial materials research. Importantly, it can also be applied to thin films that have been structured by shadow masking.

  16. Studies on sulfur poisoning and development of advanced anodic materials for waste-to-energy fuel cells applications

    Science.gov (United States)

    Zaza, Fabio; Paoletti, Claudia; LoPresti, Roberto; Simonetti, Elisabetta; Pasquali, Mauro

    Biomass is the renewable energy source with the most potential penetration in energy market for its positive environmental and socio-economic consequences: biomass live cycles for energy production is carbon neutral; energy crops promote alternative and productive utilizations of rural sites creating new economic opportunities; bioenergy productions promote local energy independence and global energy security defined as availability of energy resource supply. Different technologies are currently available for energy production from biomass, but a key role is played by fuel cells which have both low environmental impacts and high efficiencies. High temperature fuel cells, such as molten carbonate fuel cells (MCFC), are particularly suitable for bioenergy production because it can be directly fed with biogas: in fact, among its principal constituents, methane can be transformed to hydrogen by internal reforming; carbon dioxide is a safe diluent; carbon monoxide is not a poison, but both a fuel, because it can be discharged at the anode, and a hydrogen supplier, because it can produce hydrogen via the water-gas shift reaction. However, the utilization of biomass derived fuels in MCFC presents different problems not yet solved, such as the poisoning of the anode due to byproducts of biofuel chemical processing. The chemical compound with the major negative effects on cell performances is hydrogen sulfide. It reacts with nickel, the main anodic constituent, forming sulfides and blocking catalytic sites for electrode reactions. The aim of this work is to study the hydrogen sulfide effects on MCFC performances for defining the poisoning mechanisms of conventional nickel-based anode, recommending selection criteria of sulfur-tolerant materials, and selecting advanced anodes for MCFC fed with biogas.

  17. High-Performance Protonic Ceramic Fuel Cells with Thin-Film Yttrium-Doped Barium Cerate-Zirconate Electrolytes on Compositionally Gradient Anodes.

    Science.gov (United States)

    Bae, Kiho; Lee, Sewook; Jang, Dong Young; Kim, Hyun Joong; Lee, Hunhyeong; Shin, Dongwook; Son, Ji-Won; Shim, Joon Hyung

    2016-04-13

    In this study, we used a compositionally gradient anode functional layer (AFL) consisting of Ni-BaCe(0.5)Zr(0.35)Y(0.15)O(3-δ) (BCZY) with increasing BCZY contents toward the electrolyte-anode interface for high-performance protonic ceramic fuel cells. It is identified that conventional homogeneous AFLs fail to stably accommodate a thin film of BCZY electrolyte. In contrast, a dense 2 μm thick BCZY electrolyte was successfully deposited onto the proposed gradient AFL with improved adhesion. A fuel cell containing this thin electrolyte showed a promising maximum peak power density of 635 mW cm(-2) at 600 °C, with an open-circuit voltage of over 1 V. Impedance analysis confirmed that minimizing the electrolyte thickness is essential for achieving a high power output, suggesting that the anode structure is important in stably accommodating thin electrolytes.

  18. Synthesis of Li2Ti3O7 Anode Materials by Ultrasonic Spray Pyrolysis and Their Electrochemical Properties

    Directory of Open Access Journals (Sweden)

    Takayuki Kodera

    2013-06-01

    Full Text Available Ramsdellite-type lithium titanate (Li2Ti3O7 powders were synthesized by performing ultrasonic spray pyrolysis, and their chemical and physical properties were characterized by performing Scanning Electron Microscope (SEM, powder X-ray Diffraction (XRD, and Inductively Coupled Plasma (ICP analyses. The as-prepared Li2Ti3O7 precursor powders had spherical morphologies with hollow microstructures, but an irregularly shaped morphology was obtained after calcination above 900 °C. The ramsdellite Li2Ti3O7 crystal phase was obtained after the calcination at 1100 °C under an argon/hydrogen atmosphere. The first rechargeable capacity of the Li2Ti3O7 anode material was 168 mAh/g at 0.1 C and 82 mAh/g at 20 C, and the discharge capacity retention ratio was 99% at 1 C after the 500th cycle. The cycle performance of the Li2Ti3O7 anode was also highly stable at 50 °C, demonstrating the superiority of Li2Ti3O7 anode materials reported previously.

  19. Novel Mg-Doped SrMoO3 Perovskites Designed as Anode Materials for Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Vanessa Cascos

    2016-07-01

    Full Text Available SrMo1−xMxO3−δ (M = Fe and Cr, x = 0.1 and 0.2 oxides have been recently described as excellent anode materials for solid oxide fuel cells at intermediate temperatures (IT-SOFC with LSGM as the electrolyte. In this work, we have improved their properties by doping with aliovalent Mg ions at the B-site of the parent SrMoO3 perovskite. SrMo1−xMgxO3−δ (x = 0.1, 0.2 oxides have been prepared, characterized and tested as anode materials in single solid-oxide fuel cells, yielding output powers near 900 mW/cm−2 at 850 °C using pure H2 as fuel. We have studied its crystal structure with an “in situ” neutron power diffraction (NPD experiment at temperatures as high as 800 °C, emulating the working conditions of an SOFC. Adequately high oxygen deficiencies, observed by NPD, together with elevated disk-shaped anisotropic displacement factors suggest a high ionic conductivity at the working temperatures. Furthermore, thermal expansion measurements, chemical compatibility with the LSGM electrolyte, electronic conductivity and reversibility upon cycling in oxidizing-reducing atmospheres have been carried out to find out the correlation between the excellent performance as an anode and the structural features.

  20. Nanostructured Black Phosphorus/Ketjenblack-Multiwalled Carbon Nanotubes Composite as High Performance Anode Material for Sodium-Ion Batteries.

    Science.gov (United States)

    Xu, Gui-Liang; Chen, Zonghai; Zhong, Gui-Ming; Liu, Yuzi; Yang, Yong; Ma, Tianyuan; Ren, Yang; Zuo, Xiaobing; Wu, Xue-Hang; Zhang, Xiaoyi; Amine, Khalil

    2016-06-08

    Sodium-ion batteries are promising alternatives to lithium-ion batteries for large-scale applications. However, the low capacity and poor rate capability of existing anodes for sodium-ion batteries are bottlenecks for future developments. Here, we report a high performance nanostructured anode material for sodium-ion batteries that is fabricated by high energy ball milling to form black phosphorus/Ketjenblack-multiwalled carbon nanotubes (BPC) composite. With this strategy, the BPC composite with a high phosphorus content (70 wt %) could deliver a very high initial Coulombic efficiency (>90%) and high specific capacity with excellent cyclability at high rate of charge/discharge (∼1700 mAh g(-1) after 100 cycles at 1.3 A g(-1) based on the mass of P). In situ electrochemical impedance spectroscopy, synchrotron high energy X-ray diffraction, ex situ small/wide-angle X-ray scattering, high resolution transmission electronic microscopy, and nuclear magnetic resonance were further used to unravel its superior sodium storage performance. The scientific findings gained in this work are expected to serve as a guide for future design on high performance anode material for sodium-ion batteries.

  1. TiP2O7 and Expanded Graphite Nanocomposite as Anode Material for Aqueous Lithium-Ion Batteries.

    Science.gov (United States)

    Wen, Yunping; Chen, Long; Pang, Ying; Guo, Zhaowei; Bin, Duan; Wang, Yong-Gang; Wang, Congxiao; Xia, Yongyao

    2017-03-08

    This paper reports a facile sol-gel synthesis method to successfully prepare the TiP2O7/expanded graphite (EG) nanocomposite as an advanced anode material for aqueous lithium-ion batteries. The constructed TiP2O7 nanocomposites (50-100 nm) are in situ encapsulated in the pore and layer structure of expanded graphite with good conductivity and high specific surface area. As a consequence, the resulting TiP2O7/EG electrode exhibits a reversible capacity of 66 mAh g(-1) at 0.1 A g(-1) with an appropriate potential of -0.6 V before hydrogen evolution in aqueous electrolytes, and also demonstrates greatly enhanced cycling stability with 75% capacity retention after 1000 cycles at the current density of 0.5 A g(-1). A full cell consisting of TiP2O7/EG anode, LiMn2O4 cathode, and 1 M Li2SO4 electrolyte delivers a specific energy of 60 Wh kg(-1) calculated on the weight of both cathode and anode materials with an operational voltage of 1.4 V. It also exhibits superior rate capability and remarkable cycling performance with a capacity maintenance of 66% over 500 cycles at 0.2 A g(-1) and 61% at 1 A g(-1) over 2000 cycles.

  2. Nitrogen-doped carbon nanoparticles by flame synthesis as anode material for rechargeable lithium-ion batteries.

    Science.gov (United States)

    Bhattacharjya, Dhrubajyoti; Park, Hyean-Yeol; Kim, Min-Sik; Choi, Hyuck-Soo; Inamdar, Shaukatali N; Yu, Jong-Sung

    2014-01-14

    Nitrogen-doped turbostratic carbon nanoparticles (NPs) are prepared using fast single-step flame synthesis by directly burning acetonitrile in air atmosphere and investigated as an anode material for lithium-ion batteries. The as-prepared N-doped carbon NPs show excellent Li-ion stoarage properties with initial discharge capacity of 596 mA h g(-1), which is 17% more than that shown by the corresponding undoped carbon NPs synthesized by identical process with acetone as carbon precursor and also much higher than that of commercial graphite anode. Further analysis shows that the charge-discharge process of N-doped carbon is highly stable and reversible not only at high current density but also over 100 cycles, retaining 71% of initial discharge capacity. Electrochemical impedance spectroscopy also shows that N-doped carbon has better conductivity for charge and ions than that of undoped carbon. The high specific capacity and very stable cyclic performance are attributed to large number of turbostratic defects and N and associated increased O content in the flame-synthesized N-doped carbon. To the best of our knowledge, this is the first report which demonstrates single-step, direct flame synthesis of N-doped turbostratic carbon NPs and their application as a potential anode material with high capacity and superior battery performance. The method is extremely simple, low cost, energy efficient, very effective, and can be easily scaled up for large scale production.

  3. Preparation of Advanced Carbon Anode Materials from Mesocarbon Microbeads for Use in High C-Rate Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Ming-Dar Fang

    2015-06-01

    Full Text Available Mesophase soft carbon (MSC and mesophase graphite (SMG, for use in comparative studies of high C-rate Lithium Ion Battery (LIB anodes, were made by heating mesocarbon microbeads (MCMB at 1300 °C and 3000 °C; respectively. The crystalline structures and morphologies of the MSC, SMG, and commercial hard carbon (HC were investigated by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy. Additionally, their electrochemical properties, when used as anode materials in LIBs, were also investigated. The results show that MSC has a superior charging rate capability compared to SMG and HC. This is attributed to MSC having a more extensive interlayer spacing than SMG, and a greater number of favorably-oriented pathways when compared to HC.

  4. Nanoparticle Cookies Derived from Metal-Organic Frameworks: Controlled Synthesis and Application in Anode Materials for Lithium-Ion Batteries.

    Science.gov (United States)

    Wang, Shuhai; Chen, Minqi; Xie, Yanyu; Fan, Yanan; Wang, Dawei; Jiang, Ji-Jun; Li, Yongguang; Grützmacher, Hansjörg; Su, Cheng-Yong

    2016-05-01

    The capacity of anode materials plays a critical role in the performance of lithium-ion batteries. Using the nanocrystals of oxygen-free metal-organic framework ZIF-67 as precursor, a one-step calcination approach toward the controlled synthesis of CoO nanoparticle cookies with excellent anodic performances is developed in this work. The CoO nanoparticle cookies feature highly porous structure composed of small CoO nanoparticles (≈12 nm in diameter) and nitrogen-rich graphitic carbon matrix (≈18 at% in nitrogen content). Benefiting from such unique structure, the CoO nanoparticle cookies are capable of delivering superior specific capacity and cycling stability (1383 mA h g(-1) after 200 runs at 100 mA g(-1) ) over those of CoO and graphite.

  5. Nano-crystalline FeOOH mixed with SWNT matrix as a superior anode material for lithium batteries

    Institute of Scientific and Technical Information of China (English)

    Mingzhong Zou; Weiwei Wen; Jiaxin Li; Yingbin Lin; Heng Lai; Zhigao Huang

    2014-01-01

    Nano-crystalline FeOOH particles (5∼10 nm) have been uniformly mixed with electric matrix of single-walled carbon nanotubes (SWNTs) for forming FeOOH/SWNT composite via a facile ultrasonication method. Directly using the FeOOH/SWNT composite (containing 15 wt%SWNTs) as anode material for lithium battery enhances kinetics of the Li+ insertion/extraction processes, thereby effectively improving re-versible capacity and cycle performance, which delivers a high reversible capacity of 758 mAh·g-1 under a current density of 400 mA·g-1 even after 180 cycles, being comparable with previous reports in terms of electrochemical performance for FeOOH anode. The good electrochemical performance should be ascribed to the small particle size and nano-crystalline of FeOOH, as well as the good electronic conductivity of SWNT matrix.

  6. Reduced Graphene Oxide/Tin-Antimony Nanocomposites as Anode Materials for Advanced Sodium-Ion Batteries.

    Science.gov (United States)

    Ji, Liwen; Zhou, Weidong; Chabot, Victor; Yu, Aiping; Xiao, Xingcheng

    2015-11-11

    Reduced graphene oxides loaded with tin-antimony alloy (RGO-SnSb) nanocomposites were synthesized through a hydrothermal reaction and the subsequent thermal reduction treatments. Transmission electron microscope images confirm that SnSb nanoparticles with an average size of about 20-30 nm are uniformly dispersed on the RGO surfaces. When they were used as anodes for rechargeable sodium (Na)-ion batteries, these as-synthesized RGO-SnSb nanocomposite anodes delivered a high initial reversible capacity of 407 mAh g(-1), stable cyclic retention for more than 80 cycles and excellent cycle stability at ultra high charge/discharge rates up to 30C. The significantly improved performance of the synthesized RGO-SnSb nanocomposites as Na-ion battery anodes can be attributed to the synergetic effects of RGO-based flexible framework and the nanoscale dimension of the SnSb alloy particles (batteries.

  7. Electrical transport through single-wall carbon nanotube-anodic aluminum oxide-aluminum heterostructures

    Science.gov (United States)

    Kukkola, Jarmo; Rautio, Aatto; Sala, Giovanni; Pino, Flavio; Tóth, Géza; Leino, Anne-Riikka; Mäklin, Jani; Jantunen, Heli; Uusimäki, Antti; Kordás, Krisztián; Gracia, Eduardo; Terrones, Mauricio; Shchukarev, Andrey; Mikkola, Jyri-Pekka

    2010-01-01

    Aluminum foils were anodized in sulfuric acid solution to form thick porous anodic aluminum oxide (AAO) films of thickness ~6 µm. Electrodes of carboxyl-functionalized single-wall carbon nanotube (SWCNT) thin films were inkjet printed on the anodic oxide layer and the electrical characteristics of the as-obtained SWCNT-AAO-Al structures were studied. Nonlinear current-voltage transport and strong temperature dependence of conduction through the structure was measured. The microstructure and chemical composition of the anodic oxide layer was analyzed using transmission and scanning electron microscopy as well as x-ray photoelectron spectroscopy. Schottky emission at the SWCNT-AAO and AAO-Al interfaces allowed by impurity states in the anodic aluminum oxide film together with ionic surface conduction on the pore walls of AAO gives a reasonable explanation for the measured electrical conduction. Calcined AAO is proposed as a dielectric material for SWCNT-field effect transistors.

  8. Considering Critical Factors of Li-rich Cathode and Si Anode Materials for Practical Li-ion Cell Applications.

    Science.gov (United States)

    Ko, Minseong; Oh, Pilgun; Chae, Sujong; Cho, Woongrae; Cho, Jaephil

    2015-09-02

    In order to keep pace with increasing energy demands for advanced electronic devices and to achieve commercialization of electric vehicles and energy-storage systems, improvements in high-energy battery technologies are required. Among the various types of batteries, lithium ion batteries (LIBs) are among the most well-developed and commercialized of energy-storage systems. LIBs with Si anodes and Li-rich cathodes are one of the most promising alternative electrode materials for next-generation, high-energy batteries. Si and Li-rich materials exhibit high reversible capacities of 240 mAh g(-1) , respectively. However, both materials have intrinsic drawbacks and practical limitations that prevent them from being utilized directly as active materials in high-energy LIBs. Examples for Li-rich materials include phase distortion during cycling and side reactions caused by the electrolyte at the surface, and for Si, large volume changes during cycling and low conductivity are observed. Recent progress and important approaches adopted for overcoming and alleviating these drawbacks are described in this article. A perspective on these matters is suggested and the requirements for each material are delineated, in addition to introducing a full-cell prototype utilizing a Li-rich cathode and Si anode. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. MATERIAL AND PROCESS DEVELOPMENT LEADING TO ECONOMICAL HIGH-PERFORMANCE THIN-FILM SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Jie Guan; Nguyen Minh

    2003-12-01

    This report summarizes the results of the work conducted under the program: ''Material and Process Development Leading to Economical High-Performance Thin-Film Solid Oxide Fuel Cells'' under contract number DE-AC26-00NT40711. The program goal is to advance materials and processes that can be used to produce economical, high-performance solid oxide fuel cells (SOFC) capable of achieving extraordinary high power densities at reduced temperatures. Under this program, anode-supported thin electrolyte based on lanthanum gallate (LSMGF) has been developed using tape-calendering process. The fabrication parameters such as raw materials characteristics, tape formulations and sintering conditions have been evaluated. Dense anode supported LSGMF electrolytes with thickness range of 10-50 micron have been fabricated. High performance cathode based on Sr{sub 0.5}Sm{sub 0.5}CoO{sub 3} (SSC) has been developed. Polarization of {approx}0.23 ohm-cm{sup 2} has been achieved at 600 C with Sr{sub 0.5}Sm{sub 0.5}CoO{sub 3}cathode. The high-performance SSC cathode and thin gallate electrolyte have been integrated into single cells and cell performance has been characterized. Tested cells to date generally showed low performance because of low cell OCVs and material interactions between NiO in the anode and lanthanum gallate electrolyte.

  10. Dispersing SnO2 nanocrystals in amorphous carbon as a cyclic durable anode material for lithium ion batteries

    Institute of Scientific and Technical Information of China (English)

    Renzong Hu; Wei Sun; Meiqin Zeng; Min Zhu

    2014-01-01

    We demonstrate a facile route for the massive production of SnO2/carbon nanocomposite used as high-capacity anode materials of next-generation lithium-ion batteries. The nanocomposite had a unique structure of ultrafine SnO2 nanocrystals (∼5 nm, 80 wt%) homogeneously dispersed in amorphous carbon matrix. This structure design can well accommodate the volume change of Li+insertion/desertion in SnO2, and prevent the aggregation of the nanosized active materials during cycling, leading to superior cycle performance with stable reversible capacity of 400 mAh/g at a high current rate of 3.3 A/g.

  11. Degradation of 1-hydroxy-2,4-dinitrobenzene from aqueous solutions by electrochemical oxidation: role of anodic material.

    Science.gov (United States)

    Quiroz, Marco A; Sánchez-Salas, José L; Reyna, Silvia; Bandala, Erick R; Peralta-Hernández, Juan M; Martínez-Huitle, Carlos A

    2014-03-15

    Electrochemical oxidation (ECOx) of 1-hydroxy-2,4-dinitrobenzene (or 2,4-dinitrophenol: 2,4-DNP) in aqueous solutions by electrolysis under galvanostatic control was studied at Pb/PbO2, Ti/SnO2, Ti/IrxRuySnO2 and Si/BDD anodes as a function of current density applied. Oxidative degradation of 2,4-DNP has clearly shown that electrode material and the current density applied were important parameters to optimize the oxidation process. It was observed that 2,4-DNP was oxidized at few substrates to CO2 with different results, obtaining good removal efficiencies at Pb/PbO2, Ti/SnO2 and Si/BDD anodes. Trends in degradation way depend on the production of hydroxyl radicals (OH) on these anodic materials, as confirmed in this study. Furthermore, HPLC results suggested that two kinds of intermediates were generated, polyhydroxylated intermediates and carboxylic acids. The formation of these polyhydroxylated intermediates seems to be associated with the denitration step and substitution by OH radicals on aromatic rings, this being the first proposed step in the reaction mechanism. These compounds were successively oxidized, followed by the opening of aromatic rings and the formation of a series of carboxylic acids which were at the end oxidized into CO2 and H2O. On the basis of these information, a reaction scheme was proposed for each type of anode used for 2,4-D oxidation. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Microwave Plasma Chemical Vapor Deposition of Nano-Structured Sn/C Composite Thin-Film Anodes for Li-ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, Cynthia; Marcinek, M.; Hardwick, L.J.; Richardson, T.J.; Song, X.; Kostecki, R.

    2008-02-01

    In this paper we report results of a novel synthesis method of thin-film composite Sn/C anodes for lithium batteries. Thin layers of graphitic carbon decorated with uniformly distributed Sn nanoparticles were synthesized from a solid organic precursor Sn(IV) tert-butoxide by a one step microwave plasma chemical vapor deposition (MPCVD). The thin-film Sn/C electrodes were electrochemically tested in lithium half cells and produced a reversible capacity of 440 and 297 mAhg{sup -1} at C/25 and 5C discharge rates, respectively. A long term cycling of the Sn/C nanocomposite anodes showed 40% capacity loss after 500 cycles at 1C rate.

  13. Fabrication of anode-supported zirconia thin film electrolyte based core-shell particle structure for intermediate temperature solid oxide fuel cells

    Institute of Scientific and Technical Information of China (English)

    Peng Li; John T.S.Irvinen

    2013-01-01

    With a view to produce intermediate temperature SOFCs, yttria and scandia doped zirconia with a core-shell structure was prepared, then an anode supported fuel cell was fabricated by a spray method. The influences of the scandia content in the electrolyte and atmosphere conditions used in the testing experiments on phase composition, microstructure and fuel cell performance were investigated. The electrolyte was composed of cubic and tetragonal phases and SEM pictures revealed very fine grain sizes and a smooth surface of the electrolyte film, though some defects were observed in samples with high Scandia content. Coating scandia on partially stabilized zirconium particles improves both ionic conductivity of the electrolyte and power density of the fuel cell distinctly below 750 1C. Anodes were pre-sintered at 1200 1C before co-sintering with the electrolyte film to ensure that the shrinkage percentage was close to that of the electrolyte during co-sintering, avoiding warping of cell.

  14. Large-Area Carbon Nanosheets Doped with Phosphorus: A High-Performance Anode Material for Sodium-Ion Batteries.

    Science.gov (United States)

    Hou, Hongshuai; Shao, Lidong; Zhang, Yan; Zou, Guoqiang; Chen, Jun; Ji, Xiaobo

    2017-01-01

    Large-area phosphorus-doped carbon nanosheets (P-CNSs) are first obtained from carbon dots (CDs) through self-assembly driving from thermal treatment with Na catalysis. This is the first time to realize the conversion from 0D CDs to 2D nanosheets doped with phosphorus. The sodium storage behavior of phosphorus-doped carbon material is also investigated for the first time. As anode material for sodium-ion batteries (SIBs), P-CNSs exhibit superb performances for electrochemical storage of sodium. When cycled at 0.1 A g(-1), the P-CNSs electrode delivers a high reversible capacity of 328 mAh g(-1), even at a high current density of 20 A g(-1), a considerable capacity of 108 mAh g(-1) can still be maintained. Besides, this material also shows excellent cycling stability, at a current density of 5 A g(-1), the reversible capacity can still reach 149 mAh g(-1) after 5000 cycles. This work will provide significant value for the development of both carbon materials and SIBs anode materials.

  15. Soft chemical synthesis and electrochemical properties of tin oxide-based materials as anodes for lithium ion batteries

    Institute of Scientific and Technical Information of China (English)

    何则强; 李新海; 熊利芝; 吴显明; 刘恩辉; 侯朝辉; 邓凌峰

    2004-01-01

    A novel soft chemical approach was developed to synthesize tin oxide-based powders. The microstructure, morphology, and electrochemical performance of the materials were investigated by X-ray diffraction, scanning electron microscope and electrochemical methods. The results show that the particles of tin oxide-based materials form an interconnected network structure like mesoporous material. The average size of the particles is about 200 nm. The materials deliver a charge capacity of more than 570 mA*h*g-1. And the capacity loss per cycle is about 0.15% after being cycled for 30 times. The good electrochemical performance indicates that tin oxide-based materials are promising anodes for lithium ion batteries.

  16. MATERIAL AND PROCESS DEVELOPMENT LEADING TO ECONOMICAL HIGH-PERFORMANCE THIN-FILM SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Jie Guan; Atul Verma; Nguyen Minh

    2003-04-01

    This document summarizes the technical progress from September 2002 to March 2003 for the program, Material and Process Development Leading to Economical High-Performance Thin-Film Solid Oxide Fuel Cells, contract number DE-AC26-00NT40711. The causes have been identified for the unstable open circuit voltage (OCV) and low performance exhibited by the anode-supported lanthanum gallate based cells from the earlier development. Promising results have been obtained in the area of synthesis of electrolyte and cathode powders, which showed excellent sintering and densification at low temperatures. The fabrication of cells using tapecalendering process for anode-supported thin lanthanum gallate electrolyte cells and their performance optimization is in progress.

  17. Chemical synthesis of germanium nanoparticles with uniform size as anode materials for lithium ion batteries.

    Science.gov (United States)

    Wang, Liangbiao; Bao, Keyan; Lou, Zhengsong; Liang, Guobing; Zhou, Quanfa

    2016-02-21

    A simple Mg-thermal reduction reaction is reported to synthesize germanium (Ge) nanoparticles with a uniform size at a low temperature of 400 °C in an autoclave. The as-prepared Ge nanoparticles exhibit promising anode applications in lithium ion batteries with high capacity and excellent cycling stability.

  18. Marine microbial fuel cell: Use of stainless steel electrodes as anode and cathode materials

    Energy Technology Data Exchange (ETDEWEB)

    Dumas, C.; Basseguy, R.; Etcheverry, L.; Bergel, A. [Laboratoire de Genie Chimique, CNRS-INPT, Toulouse Cedex (France); Mollica, A. [CNR-ISMAR, Genoa (Italy); Feron, D. [SCCME, CEA Saclay, Gif-sur-Yvette (France)

    2007-12-01

    Numerous biocorrosion studies have stated that biofilms formed in aerobic seawater induce an efficient catalysis of the oxygen reduction on stainless steels. This property was implemented here for the first time in a marine microbial fuel cell (MFC). A prototype was designed with a stainless steel anode embedded in marine sediments coupled to a stainless steel cathode in the overlying seawater. Recording current/potential curves during the progress of the experiment confirmed that the cathode progressively acquired effective catalytic properties. The maximal power density produced of 4 mW m{sup -2} was lower than those reported previously with marine MFC using graphite electrodes. Decoupling anode and cathode showed that the cathode suffered practical problems related to implementation in the sea, which may found easy technical solutions. A laboratory fuel cell based on the same principle demonstrated that the biofilm-covered stainless steel cathode was able to supply current density up to 140 mA m{sup -2} at +0.05 V versus Ag/AgCl. The power density of 23 mW m{sup -2} was in this case limited by the anode. These first tests presented the biofilm-covered stainless steel cathodes as very promising candidates to be implemented in marine MFC. The suitability of stainless steel as anode has to be further investigated. (author)

  19. New anodizing process for magnesium alloys

    Institute of Scientific and Technical Information of China (English)

    LUO Sheng-lian; DAI Lei; ZHOU Hai-hui; CHAI Li-yuan; KUANG Ya-fei

    2006-01-01

    Compact anodic films with high hardness and good corrosion resistance on magnesium alloys were prepared by a new constant voltage and arc-free anodizing process. The effects of anodizing parameters such as applied voltage and electrolyte temperature on the peak current density and the thickness of films were investigated. In addition, the morphologies and corrosion resistance of films were investigated by scanning electron microscopy and potentiodynamic polarization, respectively. The results show that the higher the applied voltage, the higher the peak current density and the thicker the films. However, too high applied voltage may result in breakdown of films and intense sparking which may deteriorate the properties of the anodic films and bring about unsafety. The new anodizing process can be applied in a wide range of temperature. The new anodic films have numbers of pores with the diameter of 0.5 - 5.0 μm which do not transverse the entire film.

  20. Thick-Film Carbon Dioxide Sensor via Anodic Adsorbate Stripping Technique and Its Structural Dependence

    OpenAIRE

    Chung-Chiun Liu; Shih-Han Wang; Kanokorn Photinon

    2009-01-01

    A three-electrode based CO2 sensor was fabricated using thick-film technology. The performance of this sensor was further enhanced by incorporating platinum nanoparticles onto the working electrode surface. An eight-fold increase in the signal output was obtained from the electrode with the platinum nanoparticles. The sensing output was linearly related to the CO2 presented. Stability measurements demonstrated that the decline of the active surface area and the sensitivity of the sensor were ...

  1. Investigation of film solidification and binder migration during drying of Li-Ion battery anodes

    Science.gov (United States)

    Jaiser, Stefan; Müller, Marcus; Baunach, Michael; Bauer, Werner; Scharfer, Philip; Schabel, Wilhelm

    2016-06-01

    The property determining micro-structure of battery electrodes essentially evolves during drying, appointing it a paramount, yet insufficiently understood processing step in cell manufacturing. The distribution of functional additives such as binder or carbon black throughout the film strongly depends on the drying process. A representative state-of-the-art model system comprising graphite, polymeric binder, carbon black and solvent is investigated to gain an insight into the underlying processes. A new experimental approach is introduced that allows for revelation of the evolution of binder concentration gradients throughout the film during drying. Binder is detected by means of energy-dispersive x-ray spectroscopy (EDS) at the top and bottom surface. Drying kinetics is investigated and the impact of the drying process on electrochemical performance is disclosed. The enrichment of binder at the surface, which is observed while applying high drying rates, is shown to depend on two fundamental processes, namely capillary action and diffusion. The findings reveal characteristic drying stages that provide fundamental insights into film solidification. Based on that, a top-down consolidation mechanism capable of explaining the experimental findings is disclosed. Adhesion of the active layer to the substrate is shown to strongly depend on the local binder concentration in the vicinity of the substrate.

  2. N-type nano-silicon powders with ultra-low electrical resistivity as anode materials in lithium ion batteries

    Science.gov (United States)

    Yue, Zhihao; Zhou, Lang; Jin, Chenxin; Xu, Guojun; Liu, Liekai; Tang, Hao; Li, Xiaomin; Sun, Fugen; Huang, Haibin; Yuan, Jiren

    2017-06-01

    N-type silicon wafers with electrical resistivity of 0.001 Ω cm were ball-milled to powders and part of them was further mechanically crushed by sand-milling to smaller particles of nano-size. Both the sand-milled and ball-milled silicon powders were, respectively, mixed with graphite powder (silicon:graphite = 5:95, weight ratio) as anode materials for lithium ion batteries. Electrochemical measurements, including cycle and rate tests, present that anode using sand-milled silicon powder performed much better. The first discharge capacity of sand-milled silicon anode is 549.7 mAh/g and it is still up to 420.4 mAh/g after 100 cycles. Besides, the D50 of sand-milled silicon powder shows ten times smaller in particle size than that of ball-milled silicon powder, and they are 276 nm and 2.6 μm, respectively. In addition, there exist some amorphous silicon components in the sand-milled silicon powder excepting the multi-crystalline silicon, which is very different from the ball-milled silicon powder made up of multi-crystalline silicon only.

  3. Si-FeSi2/C nanocomposite anode materials produced by two-stage high-energy mechanical milling

    Science.gov (United States)

    Yang, Yun Mo; Loka, Chadrasekhar; Kim, Dong Phil; Joo, Sin Yong; Moon, Sung Whan; Choi, Yi Sik; Park, Jung Han; Lee, Kee-Sun

    2017-05-01

    High capacity retention Silicon-based nanocomposite anode materials have been extensively explored for use in lithium-ion rechargeable batteries. Here we report the preparation of Si-FeSi2/C nanocomposite through scalable a two-stage high-energy mechanical milling process, in which nano-scale Si-FeSi2 powders are besieged by the carbon (graphite/amorphous phase) layer; and investigation of their structure, morphology and electrochemical performance. Raman analysis revealed that the carbon layer structure comprised of graphitic and amorphous phase rather than a single amorphous phase. Anodes fabricated with the Si-FeSi2/C showed excellent electrochemical behavior such as a first discharge capacity of 1082 mAh g-1 and a high capacity retention until the 30th cycle. A remarkable coulombic efficiency of 99.5% was achieved within a few cycles. Differential capacity plots of the Si-FeSi2/C anodes revealed a stable lithium reaction with Si for lithiation/delithiation. The enhanced electrochemical properties of the Si-FeSi2/C nanocomposite are mainly attributed to the nano-size Si and stable solid electrolyte interface formation and highly conductive path driven by the carbon layer.

  4. LiVP2O7/C: A New Insertion Anode Material for High-Rate Lithium-Ion Battery Applications.

    Science.gov (United States)

    Mani, Vellaisamy; Kalaiselvi, Nallathamby

    2016-04-18

    LiVP2O7/C, popularly known so far as an environmentally compatible and economically viable lithium battery cathode material, was exploited for the first time as an anode through the current study. LiVP2O7/C was synthesized by adopting oxalyl dihydrazide assisted solution combustion method and explored as an anode material in rechargeable lithium cell assembly. Notably, an initial capacity of 600 mAh g(-1) was exhibited by LiVP2O7/C anode, at the rate of 0.5 C along with an excellent Coulombic efficiency of 99% up to 150 cycles. The title anode demonstrates its suitability for high capacity and high rate applications by way of exhibiting appreciable capacity values of 200, 150, 120, and 110 mAh g(-1), under the influence of 2, 4, 6, and 8 C rates, respectively. Further, LiVP2O7/C anode, when subjected to a high current 10 C rate, exhibits an acceptable capacity of 107 mAh g(-1) up to 500 cycles, which is closer to its theoretical capacity value of 117 mAh g(-1). The study demonstrates the possibility of exploiting LiVP2O7/C as yet another potential anode and thereby opens a newer avenue to explore wide variety of LiMP2O7/C composites for their probable anode behavior in rechargeable lithium batteries.

  5. Chitosan films and blends for packaging material

    NARCIS (Netherlands)

    Broek, van den L.A.M.; Knoop, J.R.I.; Kappen, F.H.J.; Boeriu, C.G.

    2015-01-01

    An increased interest for hygiene in everyday life as well as in food, feed and medical issues lead to a strong interest in films and blends to prevent the growth and accumulation of harmful bacteria. A growing trend is to use synthetic and natural antimicrobial polymers, to provide non-migratory

  6. Chitosan films and blends for packaging material

    NARCIS (Netherlands)

    Broek, van den L.A.M.; Knoop, J.R.I.; Kappen, F.H.J.; Boeriu, C.G.

    2015-01-01

    An increased interest for hygiene in everyday life as well as in food, feed and medical issues lead to a strong interest in films and blends to prevent the growth and accumulation of harmful bacteria. A growing trend is to use synthetic and natural antimicrobial polymers, to provide non-migratory an

  7. Preparation of Transparent TiO2 Nanoporous Coating with Highly Photocatalytic Activity by Anodizing Ti Film with Loose Structure

    Directory of Open Access Journals (Sweden)

    LIANG Yin

    2016-07-01

    Full Text Available The Ti film with special structure was deposited onto glass substrate by magnetron sputtering, then via the process of electrochemical anodization and annealing, a transparent TiO2 nanoporous coating (denoted as TNP with high photocatalytic activity can be directly formed on glass substrate. The crystal structure of the TNP was detected by X-ray diffractometry (XRD and the morphology of the coating was observed by scanning electron microscopy (SEM. The transmittance, wettability and adhesion of TNP were investigated by UV-Vis spectrophotometer, contact angle meter and scratch tester respectively. Finally, the photocatalytic activity of TNP was evaluated by degradation of methylene blue solution under UV illumination. The results show that the prepared TNP coating has a nanoporous structure and only anatase can be found after annealing, the transmittance of TNP coating can reach 80% or more in visible region, with a super hydrophilic surface (contact angleC0=1×10-5mol/L can reach 94% in 2 hours and the photocatalysis reaction rate constant is 1.47h-1.

  8. Determination of Antimony (III in Real Samples by Anodic Stripping Voltammetry Using a Mercury Film Screen-Printed Electrode

    Directory of Open Access Journals (Sweden)

    Olga Domínguez-Renedo

    2009-01-01

    Full Text Available This paper describes a procedure for the determination of antimony (III by differential pulse anodic stripping voltammetry using a mercury film screen-printed electrode as the working electrode. The procedure has been optimized using experimental design methodology. Under these conditions, in terms of Residual Standard Deviation (RSD, the repeatability (3.81 % and the reproducibility (5.07 % of the constructed electrodes were both analyzed. The detection limit for Sb (III was calculated at a value of 1.27×10–8 M. The linear range obtained was between 0.99 × 10–8 – 8.26 × 10–8 M. An analysis of possible effects due to the presence of foreign ions in the solution was performed and the procedure was successfully applied to the determination of antimony levels in pharmaceutical preparations and sea water samples.

  9. Electrical Conductivity and Corrosion Resistance of ZnFe2O4-Based Materials Used as Inert Anode for Aluminum Electrolysis

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    ZnFe2O4 and ZnFe2O4-based materials were tested to obtain the electrical conductivity and corrosion resistance in melting bath for aluminum electrolysis. The results proved that adequate additives, such as Ni2O3 CuO,Cu, ZnO and CeO2 would increase the electrical conductivity, and the ZnFe2O4-based anodes with these additives were of good corrosion resistance. The current density on anode, the mole ratio of NaF/AlF3 (MR) and the content of alumina in the bath effect the anode corrosion rate in different way.

  10. Interface investigations of a commercial lithium ion battery graphite anode material by sputter depth profile X-ray photoelectron spectroscopy.

    Science.gov (United States)

    Niehoff, Philip; Passerini, Stefano; Winter, Martin

    2013-05-14

    Here we provide a detailed X-ray photoelectron spectroscopy (XPS) study of the electrode/electrolyte interface of a graphite anode from commercial NMC/graphite cells by intense sputter depth profiling using a polyatomic ion gun. The uniqueness of this method lies in the approach using 13-step sputter depth profiling (SDP) to obtain a detailed model of the film structure, which forms at the electrode/electrolyte interface often noted as the solid electrolyte interphase (SEI). In addition to the 13-step SDP, several reference experiments of the untreated anode before formation with and without electrolyte were carried out to support the interpretation. Within this work, it is shown that through charging effects during X-ray beam exposure chemical components cannot be determined by the binding energy (BE) values only, and in addition, that quantification by sputter rates is complicated for composite electrodes. A rough estimation of the SEI thickness was carried out by using the LiF and graphite signals as internal references.

  11. Two-dimensional layered compound based anode materials for lithium-ion batteries and sodium-ion batteries.

    Science.gov (United States)

    Xie, Xiuqiang; Wang, Shijian; Kretschmer, Katja; Wang, Guoxiu

    2017-03-20

    Rechargeable batteries, such as lithium-ion and sodium-ion batteries, have been considered as promising energy conversion and storage devices with applications ranging from small portable electronics, medium-sized power sources for electromobility, to large-scale grid energy storage systems. Wide implementations of these rechargeable batteries require the development of electrode materials that can provide higher storage capacities than current commercial battery systems. Within this greater context, this review will present recent progresses in the development of the 2D material as anode materials for battery applications represented by studies conducted on graphene, molybdenum disulfide, and MXenes. This review will also discuss remaining challenges and future perspectives of 2D materials in regards to a full utilization of their unique properties and interactions with other battery components.

  12. Thick-Film Carbon Dioxide Sensor via Anodic Adsorbate Stripping Technique and Its Structural Dependence.

    Science.gov (United States)

    Photinon, Kanokorn; Wang, Shih-Han; Liu, Chung-Chiun

    2009-01-01

    A three-electrode based CO(2) sensor was fabricated using thick-film technology. The performance of this sensor was further enhanced by incorporating platinum nanoparticles onto the working electrode surface. An eight-fold increase in the signal output was obtained from the electrode with the platinum nanoparticles. The sensing output was linearly related to the CO(2) presented. Stability measurements demonstrated that the decline of the active surface area and the sensitivity of the sensor were 8% and 13%, respectively, over a two week period of time. The sensor response appeared to be a structural dependence of the crystallographic orientation of platinum electrode.

  13. Thick-Film Carbon Dioxide Sensor via Anodic Adsorbate Stripping Technique and Its Structural Dependence

    Directory of Open Access Journals (Sweden)

    Chung-Chiun Liu

    2009-09-01

    Full Text Available A three-electrode based CO2 sensor was fabricated using thick-film technology. The performance of this sensor was further enhanced by incorporating platinum nanoparticles onto the working electrode surface. An eight-fold increase in the signal output was obtained from the electrode with the platinum nanoparticles. The sensing output was linearly related to the CO2 presented. Stability measurements demonstrated that the decline of the active surface area and the sensitivity of the sensor were 8% and 13%, respectively, over a two week period of time. The sensor response appeared to be a structural dependence of the crystallographic orientation of platinum electrode.

  14. High-Capacity and Self-Stabilized Manganese Carbonate Microspheres as Anode Material for Lithium-Ion Batteries.

    Science.gov (United States)

    Xiao, Liang; Wang, Shiyao; Wang, Yafei; Meng, Wen; Deng, Bohua; Qu, Deyu; Xie, Zhizhong; Liu, Jinping

    2016-09-28

    Manganese carbonate (MnCO3) is an attractive anode material with high capacity based on conversion reaction for lithium-ion batteries (LIBs), but its application is mainly hindered by poor cycling performance. Building nanostructures/porous structures and nanocomposites has been demonstrated as an effective strategy to buffer the volume changes and maintain the electrode integrity for long-term cycling. It is widely believed that microsized MnCO3 is not suitable for use as anode material for LIBs because of its poor conductivity and the absence of nanostructure. Herein, different from previous reports, spherical MnCO3 with the mean diameters of 6.9 μm (MnCO3-B), 4.0 μm (MnCO3-M), and 2.6 μm (MnCO3-S) were prepared via controllable precipitation and utilized as anode materials for LIBs. It is interesting that the as-prepared MnCO3 microspheres demonstrate both high capacity and excellent cycling performance comparable to their reported nanosized counterparts. MnCO3-B, MnCO3-M, and MnCO3-S deliver reversible specific capacities of 487.3, 573.9, and 656.8 mA h g(-1) after 100 cycles, respectively. All the MnCO3 microspheres show capacity retention more than 90% after the initial stage. The advantages of MnCO3 microspheres were investigated via constant-current charge/discharge, cyclic voltammetry and electrochemical impedance spectroscopy. The results indicate that there should be substantial structure transformation from microsized particle to self-stabilized nanostructured matrix for MnCO3 at the initial charge/discharge stage. The evolution of EIS during charge/discharge clearly indicates the formation and stabilization of the nanostructured matrix. The self-stabilized porous matrix maintains the electrode structure to deliver excellent cycling performance, and contributes extra capacity beyond conversion reaction.

  15. High Pressure Hydrogen Materials Compatibility of Piezoelectric Films

    Energy Technology Data Exchange (ETDEWEB)

    Alvine, Kyle J.; Shutthanandan, V.; Bennett, Wendy D.; Bonham, Charles C.; Skorski, Daniel C.; Pitman, Stan G.; Dahl, Michael E.; Henager, Charles H.

    2010-12-02

    Abstract: Hydrogen is being considered as a next-generation clean burning fuel. However, hydrogen has well known materials issues, including blistering and embrittlement in metals. Piezoelectric materials are used as actuators in hydrogen fuel technology. We present studies of materials compatibility of piezoelectric films in a high pressure hydrogen environment. Absorption of high pressure hydrogen was studied with Elastic Recoil Detection Analysis (ERDA) and Rutherford Back Scattering (RBS) in lead zirconate titanate (PZT) and barium titanate (BTO) thin films. Hydrogen surface degradation in the form of blistering and Pb mixing was also observed.

  16. Electrochemical characteristics of ternary and quadruple lithium silicon nitrides as anode material for lithium ion batteries: the influence of precursors

    Institute of Scientific and Technical Information of China (English)

    WEN Zhongsheng; TIAN Feng; SUN Juncai; JI Shijun; XIE Jingying

    2008-01-01

    Ternary and quadruple lithium silicon nitride anode materials for lithium ion batteries with different precursors were prepared by the simple process of high-energy ball milling.High capacity and excellent cyclability were obtained.The influence of precursor introduction on the electrochemical performance of products was investigated.This research reveals that the electrochemical performance of lithium silicon hiaide can be enhanced significantly by doping O.The cyclability of quadruple lithium silicon nitride can be optimized remarkably by controlling the introduction quantity of the precursors.It is possible for the composite to be used as a capacity compensator within a wide voltage cut-off window.

  17. Lignin-based active anode materials synthesized from low-cost renewable resources

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Orlando; Tenhaeff, Wyatt Evan; Daniel, Claus; Dudney, Nancy Johnston; Johs, Alexander; Nunnery, Grady Alexander; Baker, Frederick Stanley

    2016-06-07

    A method of making an anode includes the steps of providing fibers from a carbonaceous precursor, the carbon fibers having a glass transition temperature T.sub.g. In one aspect the carbonaceous precursor is lignin. The carbonaceous fibers are placed into a layered fiber mat. The fiber mat is fused by heating the fiber mat in the presence of oxygen to above the T.sub.g but no more than 20% above the T.sub.g to fuse fibers together at fiber to fiber contact points and without melting the bulk fiber mat to create a fused fiber mat through oxidative stabilization. The fused fiber mat is carbonized by heating the fused fiber mat to at least 650.degree. C. under an inert atmosphere to create a carbonized fused fiber mat. A battery anode formed from carbonaceous precursor fibers is also disclosed.

  18. Calcium-doped ceria materials for anode of solid oxide fuel cells running on methane fuel

    Science.gov (United States)

    Zhao, Kai; Du, Yanhai

    2017-04-01

    A calcium-doped ceria with nominal compositions of Ce1-xCaxO2-δ (0.00 ≤ x ≤ 0.30) has been developed as an anode component for solid oxide fuel cells running on methane fuel. Crystal phases of Ce1-xCaxO2-δ are investigated with respect to the amount of calcium dopant. The Ce1-xCaxO2-δ shows single fluorite phase when the calcium is within 15 mol.%, and higher calcium doping levels lead to the appearance of a secondary phase (CaO). Conductivities of Ce1-xCaxO2-δ ceramics are studied by a four-probe method in air and the composition of Ce0.9Ca0.1O2-δ (x = 0.10) is found exhibiting the highest conductivity among the samples investigated in this work. Electrocatalytic properties of Ce0.9Ca0.1O2-δ are evaluated based on Ni-Ce1-xCaxO2-δ anode supported single cell running on methane fuel. At 800 °C, the single cell with Ni-Ce0.9Ca0.1O2-δ (x = 0.10) anode exhibits an optimum maximum powder density (618 mW cm-2) and good performance stability during 30 h operation in methane fuel. The promising findings substantiate the good performance of Ni-Ce0.9Ca0.1O2-δ anode for electrochemical oxidation of methane fuel.

  19. Synthesis and Electrochemical Properties of CNFs-Si Composites as an Anode Material for Li Secondary Batteries.

    Science.gov (United States)

    Park, Eun-Sil; Park, Heai-Ku; Park, Ho-Seon; Lee, Chang-Seop

    2015-11-01

    We have performed a study on the electrochemical and structural characteristics of CNFs-Si composites which are active anode material for lithium secondary batteries. Carbon nanofibers (CNFs) have been synthesized by Chemical Vapor Deposition (CVD) using Co and Cu catalysts. The CNFs on the surface of the Si particle can provide a flexible space to relieve the volumetric expansion during a charge. Therefore, the CNFs composites on Si particles were prepared on the basis of the following two processes: (1) CNFs were grown on the simple mechanical mixture of Si particles and catalysts (CNFs/Si); (2) CNFs were grown on the surface of a pyrolytic carbon that was coated with Si particles (CNFs/PC/Si). The morphology and composition of CNFs-Si composites were analyzed by SEM and EDS measurements. Crystallinity and amorphicity were investigated using XRD and Raman spectroscopy. The characteristics of the synthesized CNFs-Si composites were analyzed through XPS, TGA, and BET. The two different CNFs-Si composite materials were evaluated as the anodic material in three different electrode cells. We found that the initial capacity of the CNFs/PC/Si composite electrode was 1,361 mAh/g with retention rate of 28.4%, which was better than the retention rate of 4.9% with the CNFs/Si electrode.

  20. Silicon as a potential anode material for Li-ion batteries: where size, geometry and structure matter.

    Science.gov (United States)

    Ashuri, Maziar; He, Qianran; Shaw, Leon L

    2016-01-07

    Silicon has attracted huge attention in the last decade because it has a theoretical capacity ∼10 times that of graphite. However, the practical application of Si is hindered by three major challenges: large volume expansion during cycling (∼300%), low electrical conductivity, and instability of the SEI layer caused by repeated volume changes of the Si material. Significant research efforts have been devoted to addressing these challenges, and significant breakthroughs have been made particularly in the last two years (2014 and 2015). In this review, we have focused on the principles of Si material design, novel synthesis methods to achieve such structural designs, and the synthesis-structure-performance relationships to enhance the properties of Si anodes. To provide a systematic overview of the Si material design strategies, we have grouped the design strategies into several categories: (i) particle-based structures (containing nanoparticles, solid core-shell structures, hollow core-shell structures, and yolk-shell structures), (ii) porous Si designs, (iii) nanowires, nanotubes and nanofibers, (iv) Si-based composites, and (v) unusual designs. Finally, our personal perspectives on outlook are offered with an aim to stimulate further discussion and ideas on the rational design of durable and high performance Si anodes for the next generation Li-ion batteries in the near future.

  1. Preparation of Advanced CuO Nanowires/Functionalized Graphene Composite Anode Material for Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Jin Zhang

    2017-01-01

    Full Text Available The copper oxide (CuO nanowires/functionalized graphene (f-graphene composite material was successfully composed by a one-pot synthesis method. The f-graphene synthesized through the Birch reduction chemistry method was modified with functional group “–(CH25COOH”, and the CuO nanowires (NWs were well dispersed in the f-graphene sheets. When used as anode materials in lithium-ion batteries, the composite exhibited good cyclic stability and decent specific capacity of 677 mA·h·g−1 after 50 cycles. CuO NWs can enhance the lithium-ion storage of the composites while the f-graphene effectively resists the volume expansion of the CuO NWs during the galvanostatic charge/discharge cyclic process, and provide a conductive paths for charge transportation. The good electrochemical performance of the synthesized CuO/f-graphene composite suggests great potential of the composite materials for lithium-ion batteries anodes.

  2. Preparation of Advanced CuO Nanowires/Functionalized Graphene Composite Anode Material for Lithium Ion Batteries

    Science.gov (United States)

    Zhang, Jin; Wang, Beibei; Zhou, Jiachen; Xia, Ruoyu; Chu, Yingli; Huang, Jia

    2017-01-01

    The copper oxide (CuO) nanowires/functionalized graphene (f-graphene) composite material was successfully composed by a one-pot synthesis method. The f-graphene synthesized through the Birch reduction chemistry method was modified with functional group “–(CH2)5COOH”, and the CuO nanowires (NWs) were well dispersed in the f-graphene sheets. When used as anode materials in lithium-ion batteries, the composite exhibited good cyclic stability and decent specific capacity of 677 mA·h·g−1 after 50 cycles. CuO NWs can enhance the lithium-ion storage of the composites while the f-graphene effectively resists the volume expansion of the CuO NWs during the galvanostatic charge/discharge cyclic process, and provide a conductive paths for charge transportation. The good electrochemical performance of the synthesized CuO/f-graphene composite suggests great potential of the composite materials for lithium-ion batteries anodes. PMID:28772432

  3. Encapsulated Vanadium-Based Hybrids in Amorphous N-Doped Carbon Matrix as Anode Materials for Lithium-Ion Batteries.

    Science.gov (United States)

    Long, Bei; Balogun, Muhammad-Sadeeq; Luo, Lei; Luo, Yang; Qiu, Weitao; Song, Shuqin; Zhang, Lei; Tong, Yexiang

    2017-09-12

    Recently, researchers have made significant advancement in employing transition metal compound hybrids as anode material for lithium-ion batteries and developing simple preparation of these hybrids. To this end, this study reports a facile and scalable method for fabricating a vanadium oxide-nitride composite encapsulated in amorphous carbon matrix by simply mixing ammonium metavanadate and melamine as anode materials for lithium-ion batteries. By tuning the annealing temperature of the mixture, different hybrids of vanadium oxide-nitride compounds are synthesized. The electrode material prepared at 700 °C, i.e., VM-700, exhibits excellent cyclic stability retaining 92% of its reversible capacity after 200 cycles at a current density of 0.5 A g(-1) and attractive rate performance (220 mAh g(-1) ) under the current density of up to 2 A g(-1) . The outstanding electrochemical properties can be attributed to the synergistic effect from heterojunction form by the vanadium compound hybrids, the improved ability of the excellent conductive carbon for electron transfer, and restraining the expansion and aggregation of vanadium oxide-nitride in cycling. These interesting findings will provide a reference for the preparation of transition metal oxide and nitride composites as well. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Carbon nanotube entangled Mn3O4 octahedron as anode materials for lithium-ion batteries

    Science.gov (United States)

    Cui, Xia; Wang, Yuqiao; Xu, Qingyu; Sun, Pingping; Wang, Xiuzhen; Wei, Tao; Sun, Yueming

    2017-06-01

    A nanocomposite of Mn3O4 octahedrons entangled by carbon nanotubes (CNTs) was synthesized by a hydrothermal method assisted with a non-ionic surfactant. The integration of octahedral structure and CNTs could offer many critical features, which are needed for high activity anodes, such as fast ion diffusion, good electronic conductivity, and skeleton supporting function, thus enabling the nanocomposite-based anodes with excellent electrochemical performance. In addition, CNTs can not only serve as the conductive network and structure skeleton to improve the anode performance, but also play an indispensable role in the formation of more uniform Mn3O4 octahedrons. The lithium-ion batteries based on the CNTs-entangled Mn3O4 octahedrons delivered a high capacity of over 800 mAh g-1 at a current density of 0.2 C for 200 cycles, and even as high as 678.4 mAh g-1 when cycled at 0.5 C after 400 cycles, exhibiting a high capability and ultralong cycle life.

  5. High-Performance Si/SiOx Nanosphere Anode Material by Multipurpose Interfacial Engineering with Black TiO(2-x).

    Science.gov (United States)

    Bae, Juhye; Kim, Dae Sik; Yoo, Hyundong; Park, Eunjun; Lim, Young-Geun; Park, Min-Sik; Kim, Young-Jun; Kim, Hansu

    2016-02-01

    Silicon oxides (SiOx) have attracted recent attention for their great potential as promising anode materials for lithium ion batteries as a result of their high energy density and excellent cycle performance. Despite these advantages, the commercial use of these materials is still impeded by low initial Coulombic efficiency and high production cost associated with a complicated synthesis process. Here, we demonstrate that Si/SiOx nanosphere anode materials show much improved performance enabled by electroconductive black TiO(2-x) coating in terms of reversible capacity, Coulombic efficiency, and thermal reliability. The resulting anode material exhibits a high reversible capacity of 1200 mAh g(-1) with an excellent cycle performance of up to 100 cycles. The introduction of a TiO(2-x) layer induces further reduction of the Si species in the SiOx matrix phase, thereby increasing the reversible capacity and initial Coulombic efficiency. Besides the improved electrochemical performance, the TiO(2-x) coating layer plays a key role in improving the thermal reliability of the Si/SiOx nanosphere anode material at the same time. We believe that this multipurpose interfacial engineering approach provides another route toward high-performance Si-based anode materials on a commercial scale.

  6. A flow injection method for the analysis of tetracycline antibiotics in pharmaceutical formulations using electrochemical detection at anodized boron-doped diamond thin film electrode.

    Science.gov (United States)

    Wangfuengkanagul, N; Siangproh, W; Chailapakul, O

    2004-12-15

    A method using flow injection (FI) with amperometric detection at anodized boron-doped diamond (BDD) thin films has been developed and applied for the determination of tetracycline antibiotics (tetracycline, chlortetracycline, oxytetracycline and doxycycline). The electrochemical oxidation of the tetracycline antibiotics was studied at various carbon electrodes including glassy carbon (GC), as-deposited BDD and anodized BDD electrodes using cyclic voltammetry. The anodized BDD electrode exhibited well-defined irreversible cyclic voltammograms for the oxidation of tetracycline antibiotics with the highest current signals compared to the as-deposited BDD and glassy carbon electrodes. Low detection limit of 10nM (signal-to-noise ratio = 3) was achieved for each drug when using flow injection analysis with amperometric detection at anodized BDD electrodes. Linear calibrations were obtained from 0.1 to 50mM for tetracycline and 0.5-50mM for chlortetracycline, oxytetracycline and doxycycline. The proposed method has been successfully applied to determine the tetracycline antibiotics in some drug formulations. The results obtained in percent found (99.50-103.01%) were comparable to dose labeled.

  7. Left-handed materials in magnetized metallic magnetic thin films

    Institute of Scientific and Technical Information of China (English)

    WU Rui-xin; XIAO John Q.

    2006-01-01

    The authors' theoretical investigation on the high-frequency response of magnetized metallic magnetic films showed that magnetic films may become left-handed materials (LHMs) near the ferromagnetic resonance frequency of incident waves with right-handed circular polarization (RCP) and linear polarization (LP). The frequency range where LHM exists depends on the waves polarization, the magnetic damping coefficient, and the ferromagnetic characteristic frequency ωm of the film. There also exists a critical damping coefficient αc, above which the left-handed properties disappear completely.

  8. ZrN/Cu nanocomposite film - a novel superhard material

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J.; Zeman, P. [Univ. of West Bohemia, Plzen (Czech Republic). Dept. of Phys.; Hruby, H.; Mayrhofer, P.H. [Montanuniversitaet Leoben (Austria). Inst. fuer Metallkunde und Werkstoffpruefung

    1999-11-01

    This article reports on the structure and hardness of ZrCu-N films prepared by dc reactive magnetron sputtering of a ZrCu alloyed target in a mixture of Ar+N{sub 2} using a round planar unbalanced magnetron of diameter 100 mm. It was found that there is a strong correlation between the structure of the film and its hardness. The hard (<40 GPa) ZrCu-N films are characterized by many weak reflections from poly-oriented ZrN and Cu grains. In contrast, the superhard ({>=}40 GPa) ZrCu-N films are characterized by a strong reflection from ZrN grains with a dominate ZrN(111) orientation and no reflections from Cu. The superhard ZrCu-N films with a hardness of 54 GPa are nc-ZrN/Cu nanocomposite films composed of strongly oriented ZrN grains surrounded by a thin layer of Cu. These films exhibit a high elastic recovery of about 80% (determined by a microhardness tester) and contain approximately 1-2 wt.% Cu. The superhard nc-ZrN/Cu nanocomposite films represent a new class of superhard materials of the type nc-MeN/metal. (orig.)

  9. An investigation into the doping and crystallinity of anodically fabricated titania nanotube arrays: Towards an efficient material for solar energy applications

    Science.gov (United States)

    Allam Abdel-Motalib, Nageh Khalaf

    The primary focus of this dissertation was to improve the properties of the anodically fabricated TiO2 nanotube arrays; notably its band gap and crystallinity while retaining its tubular structure unaffected. The underlying hypothesis was that controlling the crystallinity and band gap while retaining the tubular structure will result in an enormous enhancement of the photoconversion capability of the material. To this end, a direct one-step facile approach for the in-situ doping of TiO2 nanotube arrays during their electrochemical fabrication in both aqueous and non-aqueous electrolytes has been investigated. The effect of doping on the morphology, optical and photoelectrochemical properties of the fabricated nanotube arrays is discussed. In an effort to improve the crystallinity of the anodically fabricated TiO2 nanotube arrays while retaining the tubular morphology, novel processing routes have been investigated to fabricate crystalline TiO 2 nanotube array electrodes. For the sake of comparison, the nanotubes were annealed at high temperature using the conventionally used procedure. The samples were found to be stable up to temperatures around 580°C, however, higher temperatures resulted in crystallization of the titanium support which disturbed the nanotube architecture, causing it to partially and gradually collapse and densify. The maximum photoconversion efficiency for water splitting using 7 mum-TiO2 nanotube arrays electrodes annealed at 580°C was measured to be about 10% under UV illumination. We investigated the effect of subsequent low temperature crystallization step. Rapid infrared (IR) annealing was found to be an efficient technique for crystallizing the nanotube array films within a few minutes. The IR-annealed 7mum-nanotube array films showed significant photoconversion efficiencies (eta=13.13%) upon their use as photoanodes to photoelectrochemically split water under UV illumination. This was related, in part, to the reduction in the barrier

  10. Research Progress in Anode Materials for Power Li-ion Batteries%锂离子动力电池负极材料研究进展

    Institute of Scientific and Technical Information of China (English)

    池永庆; 孙彦平

    2012-01-01

    The progress in research of anode materials of lithium-ion batteries is reviewed. The effects of the compositions, the sizes of the anode materials and the operation temperatures on its performance such as specific capacity, specific power, cycle life and charge/discharge rate capability of the battery, are highlighted, as well as the theoretical studies on the anode materials by mathematical modeling the system of full cell or a half cell of the battery. Improving the performance of the anode materials of carbon/graphite and non-carbon/graphite, preparing the high orderly array anode to enhance the dynamical performance of lithium-ion batteries, will be important aspects for further studying; developing mathematical models to simulate the process of charging and discharging for analyzing the anode dynamics is an efficient way to characterize and optimize the anode materials.%综述了锂离子电池负极材料研究进展,着重介绍了负极材料活性成分、材料尺度及操作温度对电池比容量、比功率、循环寿命、充放电倍率性能的影响,以及数模化半电池或全电池系统对负极材料电极性能的理论研究.为了提高锂离子电池动力性能,改进碳/石墨和非碳/石墨负极材料、制备高度有序的阵列负极将成为今后研究的重要方向;建立数学模型模拟充放电过程、分析负极材料的电极动力学特性,是表征、优化负极材料的有效方法.

  11. Preparation and characterization of TiO2 anode film with spinodal phase separation structure in dye-sensitized solar cells

    Science.gov (United States)

    Guli, Mina; Yao, Jianxi; Zhao, Jingyong; Rao, Wangping; Xiao, Li; Tian, Hongxin

    2013-10-01

    Low electronic transmission efficiency and high charge recombination are the existing problems of photoanode film in traditional dye sensitized solar cells (DSSCs). This paper put forward the photoanode TiO2 films with spinodal phase separation structure (SPSS) and continuous TiO2 skeleton which were triggered by the photopolymerization of organic monomers in a photomonomer-inorganic precursor system. The photoanode TiO2 films fabricated by different precursor solution compositions and different coating layers were characterized mainly by scanning electron microscopy (SEM), photocatalysis and photoelectric performance test. The results indicated that, the as-prepared TiO2 anode film with seven coating layers and heat treated at 500 °C showed higher photoelectric conversion efficiency at about 2% than that of other samples with less coating layers and lower heat treatment temperature. The film also showed excellent photocatalytic activity by using methylene blue (MB) dye as a model organic substrate under fluorescent lamp irradiation. It is suggested that the film with SPSS structure has the potential to improve the electronic transmission efficiency and reduce the carrier recombination due to its particular structure, higher surface area, and lack of bottleneck in electronic transmission. It is worth noting that the SPSS structure provides new ideas to develop new photoanode films and further improve the photoelectric conversion performance of the DSSC in future.

  12. Anodic performance in lithium-ion batteries of graphite-like materials prepared from anthracites and unburned carbon concentrates from coal combustion fly ashes

    Directory of Open Access Journals (Sweden)

    I. Cameán

    2013-01-01

    Full Text Available The electrochemical performance as anodes for lithium-ion batteries of graphite-like materials that were prepared from anthracites and unburned carbon concentrates from coal combustion fly ashes by high temperature treatment was investigated by galvanostatic cycling of lithium test cells. Some of the materials prepared have provided reversible capacities up to ~ 310 mA h g-1 after 50 discharge/ charge cycles. These values are similar to those of oil-derived graphite (petroleum coke being the main precursor which is currently used as anodic material in commercial lithium-ion batteries.

  13. Interconnected CoFe2O4-Polypyrrole Nanotubes as Anode Materials for High Performance Sodium Ion Batteries.

    Science.gov (United States)

    He, Qiming; Rui, Kun; Chen, Chunhua; Yang, Jianhua; Wen, Zhaoyin

    2017-10-10

    CoFe2O4-coated polypyrrole (PPy) nanotubes (CFO-PPy-NTs) with three-dimensional (3-D) interconnected networks have been prepared through a simple hydrothermal method. The application has been also studied for sodium ion batteries (SIBs). The finely crystallized CoFe2O4 nanoparticles (around 5 nm in size) are uniformly grown on the PPy nanotubes. When tested as anode materials for SIBs, the CFO-PPy-NT electrode maintains a discharge capacity of 400 mA h g(-1) and a stable Coulombic efficiency of 98% after 200 cycles at 100 mA g(-1). Even at a higher current density of 1000 mA g(-1), the composite can still retain a discharge capacity of 220 mA h g(-1) after 2000 cycles. The superior electrochemical performance could be mainly ascribed to the uniform distribution of CoFe2O4 on the 3-D matrix of PPy interconnected nanotubes, which favors the diffusion of sodium ions and electronic transportation and also buffers the large volumetric expansion during charge/discharge. Thereby our study suggests that such CFO-PPy-NTs have great potential as an anode material for SIBs.

  14. Ce-doped α-FeOOH nanorods as high-performance anode material for energy storage

    Science.gov (United States)

    Zhai, Yanjun; Xu, Liqiang; Qian, Yitai

    2016-09-01

    Ce-doped α-FeOOH nanorods with high yields were conveniently prepared by a hydrothermal method followed by an acid-treatment process. It is found that Ce uniformly distributes in the α-FeOOH nanorod nanostructures through elemental mapping analysis. The 0.5 wt% Ce-doped α-FeOOH electrode displayed excellent cycling performance with a high discharge capacity of 830 mA h g-1 after 800 charge/discharge cycles at a high current of 2000 mA g-1. The enhanced electrochemical performance can be attributed to the improved electronic conductivity, Li-ion diffusion kinetics and structure stability after Ce doping. Furthermore, a 0.5 wt% Ce-doped α-FeOOH//LiFePO4 lithium ion cell with an initial discharge capacity of 580 mA h g-1 at 1000 mA g-1 based on the total weight of the anode material has been fabricated for the first time. The obtained 0.5 wt% Ce-doped α-FeOOH electrode as anode material for sodium-ion batteries also exhibits a high initial discharge capacity of 587 mA h g-1 at 100 mA g-1.

  15. Ultrahigh capacity anode material for lithium ion battery based on rod gold nanoparticles decorated reduced graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Atar, Necip, E-mail: necipatar@gmail.com [Department of Chemical Engineering, Pamukkale University, Denizli (Turkey); Eren, Tanju [Department of Chemical Engineering, Pamukkale University, Denizli (Turkey); Yola, Mehmet Lütfi [Department of Metallurgical and Materials Engineering, Sinop University, Sinop (Turkey)

    2015-09-01

    In this study, we report the synthesis of rod shaped gold nanoparticles/2-aminoethanethiol functionalized reduced graphene oxide composite (rdAuNPs/AETrGO) and its application as an anode material for lithium-ion batteries. The structure of the rdAuNPs/AETrGO composite was characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. The electrochemical performance was investigated at different current rates by using a coin-type cell. It was found that the rod shaped gold nanoparticles were highly dispersed on the reduced graphene oxide sheets. Moreover, the rdAuNPs/AETrGO composite showed a high specific gravimetric capacity of about 1320 mAh g{sup −1} and a long-term cycle stability. - Highlights: • We prepared rod shaped gold nanoparticles functionalized reduced graphene oxide. • The nanocomposite was used as an anode material for lithium-ion batteries. • The nanocomposite showed a high specific gravimetric capacity of about 1320 mAh g{sup −1}. • The nanocomposite exhibited a long-term cycle stability.

  16. Synthesis And Electrochemical Characteristics Of Mechanically Alloyed Anode Materials SnS2 For Li/SnS2 Cells

    Directory of Open Access Journals (Sweden)

    Hong J.H.

    2015-06-01

    Full Text Available With the increasing demand for efficient and economic energy storage, tin disulfide (SnS2, as one of the most attractive anode candidates for the next generation high-energy rechargeable Li-ion battery, have been paid more and more attention because of its high theoretical energy density and cost effectiveness. In this study, a new, simple and effective process, mechanical alloying (MA, has been developed for preparing fine anode material tin disulfides, in which ammonium chloride (AC, referred to as process control agents (PCAs, were used to prevent excessive cold-welding and accelerate the synthesis rates to some extent. Meanwhile, in order to decrease the mean size of SnS2 powder particles and improve the contact areas between the active materials, wet milling process was also conducted with normal hexane (NH as a solvent PCA. The prepared powders were both characterized by X-ray diffraction, Field emission-scanning electron microscopeand particle size analyzer. Finally, electrochemical measurements for Li/SnS2 cells were takenat room temperature, using a two-electrode cell assembled in an argon-filled glove box and the electrolyte of 1M LiPF6 in a mixture of ethylene carbonate(EC/dimethylcarbonate (DMC/ethylene methyl carbonate (EMC (volume ratio of 1:1:1.

  17. Enhancing low-field magnetoresistance of La0.67Ca0.33MnO3 films deposited on anodized aluminium-oxide membranes

    Institute of Scientific and Technical Information of China (English)

    Tang Wei-Hua; Li Pei-Gang; Lei Ming; Guo Yan-Feng; Chen Lei-Ming; Li Ling-Hong; Song Peng-Yun; Chen ChinPing

    2006-01-01

    In this paper we report a new method to fabricate nanostructured films.La0.67Ca0.33MnO3(LCMO)nanostructured films have been fabricated by using pulsed electron beam deposition (PED) on anodized aluminium oxide (AAO)membranes.The magnetic and electronic transport properties are investigated by using the Quantum Design physics properties measurement system (PPMS) and magnetic properties measurement system (MPMS).The resistance peak temperature (Tp) is about 85 K and the Curie temperature(Tc) is about 250 K for the LCMO film on an AAO membrane with a pore diameter of 20 nm.Large magnetoresistance ratio (MR) is observed near Tp.The MR is as high as 85 %under 1T magnetic field.The great enhancement of MR at low magnetic fields could be attributed to the lattice distortion and the grain boundary that are induced by the nanopores on the AAO membrane.

  18. Comparison in interfacial phenomena in electric-field assisted anodic bonding of Kovar-glass and Kovar/Al film-glass

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Anodic bonding of Kovar-glass and Kovar/Al film-glass were performed at temperatures of 513(¨)K to 663(¨)K under the static electric voltage of 500(¨)V, in order to compare the interfacial phenomena in electric-field assisted anodic bonding of Kovar-glass and Al-glass . SEM and EPMA were used to observe and analyzed the interfacial region. The growth rate of the alkali ions depletion layers in Kovar/Al-glass joint was slower than that in Kovar-glass joint. But the activation energies for the growth of depletion layers are about the same for both kinds of joint.

  19. Microfluidic anodization of aluminum films for the fabrication of nanoporous lipid bilayer support structures

    OpenAIRE

    2011-01-01

    Solid state nanoporous membranes show great potential as support structures for biointerfaces. In this paper, we present a technique for fabricating nanoporous alumina membranes under constant-flow conditions in a microfluidic environment. This approach allows the direct integration of the fabrication process into a microfluidic setup for performing biological experiments without the need to transfer the brittle nanoporous material. We demonstrate this technique by using the same microfluidic...

  20. Fundamental Investigation of Silicon Anode in Lithium-Ion Cells

    Science.gov (United States)

    Wu, James J.; Bennett, William R.

    2012-01-01

    Silicon is a promising and attractive anode material to replace graphite for high capacity lithium ion cells since its theoretical capacity is 10 times of graphite and it is an abundant element on Earth. However, there are challenges associated with using silicon as Li-ion anode due to the significant first cycle irreversible capacity loss and subsequent rapid capacity fade during cycling. Understanding solid electrolyte interphase (SEI) formation along with the lithium ion insertion/de-insertion kinetics in silicon anodes will provide greater insight into overcoming these issues, thereby lead to better cycle performance. In this paper, cyclic voltammetry and electrochemical impedance spectroscopy are used to build a fundamental understanding of silicon anodes. The results show that it is difficult to form the SEI film on the surface of a Si anode during the first cycle; the lithium ion insertion and de-insertion kinetics for Si are sluggish, and the cell internal resistance changes with the state of lithiation after electrochemical cycling. These results are compared with those for extensively studied graphite anodes. The understanding gained from this study will help to design better Si anodes, and the combination of cyclic voltammetry with impedance spectroscopy provides a useful tool to evaluate the effectiveness of the design modifications on the Si anode performance.

  1. Facile one-pot synthesis of spherical zinc sulfide-carbon nanocomposite powders with superior electrochemical properties as anode materials for Li-ion batteries.

    Science.gov (United States)

    Jang, Yong Seung; Kang, Yun Chan

    2013-10-21

    A novel and simple one-pot method of systematically synthesizing spherical metal sulfide-carbon composite powders is reported for the first time. The zinc sulfide-carbon composite is selected as the first target material. The prepared composite powders show superior electrochemical properties as anode materials for lithium-ion batteries.

  2. Electronic processes in thin-film PV materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, P.C.; Chen, D.; Chen, S.L. [and others

    1998-07-01

    The electronic and optical processes in an important class of thin-film PV materials, hydrogenated amorphous silicon (a-Si:H) and related alloys, have been investigated using several experimental techniques designed for thin-film geometries. The experimental techniques include various magnetic resonance and optical spectroscopies and combinations of these two spectroscopies. Two-step optical excitation processes through the manifold of silicon dangling bond states have been identifies as important at low excitation energies. Local hydrogen motion has been studied using nuclear magnetic resonance techniques and found to be much more rapid than long range diffusion as measured by secondary ion mass spectroscopy. A new metastable effect has been found in a-Si:H films alloyed with sulfur. Spin-one optically excited states have been unambiguously identified using optically detected electron spin resonance. Local hydrogen bonding in microcrystalline silicon films has been studied using NMR.

  3. Ferroelectric thin films using oxides as raw materials

    Directory of Open Access Journals (Sweden)

    E.B. Araújo

    1999-01-01

    Full Text Available This work describes an alternative method for the preparation of ferroelectric thin films based on pre-calcination of oxides, to be used as precursor material for a solution preparation. In order to show the viability of the proposed method, PbZr0.53Ti0.47O3 and Bi4Ti3O12 thin films were prepared on fused quartz and Si substrates. The results were analyzed by X-ray Diffraction (XRD, Scanning Electron Microscopy (SEM, Infrared Spectroscopy (IR and Rutherford Backscattering Spectroscopy (RBS. The films obtained show good quality, homogeneity and the desired stoichiometry. The estimated thickness for one layer deposition was approximately 1000 Å and 1500 Å for Bi4Ti3O12 and PbZr0.53Ti0.47O3 films, respectively.

  4. Zinc pyridinedicarboxylate micro-nanostructures: Promising anode materials for lithium-ion batteries with excellent cycling performance.

    Science.gov (United States)

    Fei, Hailong; Lin, Yaqin

    2016-11-01

    It is important to discover new, cheap and environmental friendly coordination polymer electrode materials for lithium-ion batteries. Zinc 2,6-pyridilinedicarboxylate particles show better cycling stability and higher discharge capacity than 2,5-pyridilinedicarboxylate micro-platelets when they are firstly tested as anode materials for lithium-ion batteries. The former can steadily cycle at current densities of 750, 1000 and 2000mAg(-1). It is also stable in multiple insertion/extraction processes at current densities of 750, 1500, 2000, 2500, 3000, and 750mAg(-1), and the capacity retention is 77.9% after 60cycles. While the latter is apt to show good cycling performance at smaller discharge current density.

  5. Electrospinning synthesis of 3D porous NiO nanorods as anode material for lithium-ion batteries

    Directory of Open Access Journals (Sweden)

    Wei Kong Xiang

    2016-06-01

    Full Text Available Three-dimensional NiO nanorods were synthesized as anode material by electrospinning method. X-ray diffraction results revealed that the product sintered at 400 °C had impure metallic nickel phase which, however, became pure NiO phase as the sintering temperature rose. Nevertheless, the nanorods sintered at 400, 500 and 600 °C had similar diameters (∼200 nm.The NiO nanorod material sintered at 500 °C was chip-shaped with a diameter of 200 nm and it exhibited a porous 3D structure. The nanorod sintered at 500 °C had the optimal electrochemical performance. Its discharge specific capacity was 1127 mAh·g−1 initially and remained as high as 400 mAh·g−1 at a current density of 55 mA·g−1 after 50 cycles.

  6. Metalated graphene nanoplatelets and their uses as anode materials for lithium-ion batteries

    Science.gov (United States)

    Xu, Jiantie; Jeon, In-Yup; Choi, Hyun-Jung; Kim, Seok-Jin; Shin, Sun-Hee; Park, Noejung; Dai, Liming; Baek, Jong-Beom

    2017-03-01

    A series of post-transition metals and semimetals in groups IIIA (Al, Ga, In), IVA (Ge, Sn, Pb) and VA (As, Sb, Bi) were introduced onto graphene nanoplatelets (GnPs) by mechanochemical reaction. The selected metals have a lower electronegativity (χ, 1.61 ≤ χ M ≤ 2.18) but a much larger covalent atomic radius (d M = 120-175 pm) than carbon (χ C = 2.55, d C = 77 pm). The effect of the electronegativity and atomic radius of the metalated GnPs (MGnPs, M = Al, Ga, In, Ge, Sn, Pb, As, Sb, or Bi) on the anode performance of lithium-ion batteries was evalusted. Among the series of prepared MGnPs, GaGnP (χ Ga = 1.81, d Ga = 135 pm) in group IIIA, SnGnP (χ Sn = 1.96, d Sn = 140 pm) in group IVA and SbGnP (χ Sb = 2.05, d Sb = 141 pm) in group VA exhibited significantly enhanced performance, including higher capacity, rate capability and initial Coulombic efficiency. Both the experimental results and theoretical calculations indicated that the optimum atomic size (d M ˜ 140 pm) was more significant to the anode performance than electronegativity, allowing not only efficient electrolyte penetration but also fast electron and ion transport across the graphitic layers.

  7. Research progress in anode materials for Li-ion battery%锂离子电池负极材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    武明昊; 陈剑; 王崇; 衣宝廉

    2011-01-01

    综述了近年来锂离子电池负极材料的研究进展,包括碳材料、过渡金属氧化物,锡基和硅基材料等,重点评述了锡基和硅基材料的研究进展,并对锂离子电池负极材料的发展趋势进行了展望.%Research progress in anode materials for Li-ion battery in recent years, including carbon, transition metal oxides, tin based composites and silicon based composites was reviewed. The research progress in tin based and silicon based anode materials was commented emphatically,the development tendency of Li-ion battery anode materials was prospected.

  8. The electrochemical effect of various Si/Zr molar ratios on anode materials in lithium-ion batteries.

    Science.gov (United States)

    Choi, DongWoong; Choy, KwangLeong

    2017-10-09

    The aim of this study was to unveil the mechanisms of SiO2/ZrO2 (SSZ) anode materials through electrochemical analysis and to understand the effect of various Si/Zr molar ratios (Si/Zr = 0.5, 1, and 2) on the performance of SSZ anode materials with these mechanisms. The 2-SSZ (Si/Zr = 2) electrode had a much higher capacity than that of the 0.5- or 1-SSZ (Si/Zr = 0.5 or 1) electrode. It exhibited superior cycling performance when compared to commercial graphite (theoretical capacity of 372 mA h g(-1)). The 2-SSZ had a capacity of 461 mA h g(-1) at a high current density of 100 mA g(-1) over 30 cycles. These characteristics are due to the effects from each of the different reversible materials formed by the SSZs. Zr2Si and Zr5Si3, ZrSi, or ZrSi2 were formed by the 0.5-, 1-, and 2-SSZs, respectively, which would affect the reversible storage capacity. ZrSi2 provided an increase in the possible reaction area for the guest species (lithium ions) at the empty interstitial site in the host materials as well as a large area for accommodating a volume change. It was supportive by maintaining the lattice constant and reducing the ratio of the structure distortion. Furthermore, the 2-SSZ structure consisted of an overall amorphous structure with a crystalline structure related to the Zr-O-Si bond unlike the 0.5- and 1-SSZs which had an overall crystalline structure. Such a combined structure of 2-SSZ was advantageous for providing good capacity due to the amorphous structure and an efficient pathway for electron transport and little pulverization due to the crystalline structure. This structure led to its superior performance and long lifespan.

  9. Electrodeposited polymer encapsulated nickel sulphide thin films: frequency switching material

    Energy Technology Data Exchange (ETDEWEB)

    Jana, Sumanta, E-mail: sumantajana85@gmail.com [Department of Chemistry, Bengal Engineering and Science University, Botanic Garden, Howrah 711103, WB (India); Mukherjee, Nillohit [Centre of Excellence for Green Energy and Sensor Systems, Bengal Engineering and Science University, Howrah 711103, WB (India); Chakraborty, Biswajit [Department of Chemistry, Vivekananda Mahavidyalay, Burdwan 713103, WB (India); Mitra, Bibhas Chandra [Department of Physics, Bengal Engineering and Science University, Botanic Garden, Howrah 711103, WB (India); Mondal, Anup, E-mail: anupmondal2000@yahoo.co.in [Department of Chemistry, Bengal Engineering and Science University, Botanic Garden, Howrah 711103, WB (India)

    2014-05-01

    Graphical abstract: Polyvinylpyrrolidone encapsulated NiS thin films were synthesized electrochemically. The light induced frequency switching study of the synthesized material was carried out and it was observed that the films performed well as a switching device under 1 Sun illumination. This pulse generation within an insulating polymer encapsulated semicondctor matrix (PVP NiS) might be due to surface covering which leads to reduction of recombination process. Highlights: • PVP-NiS thin films were electrochemically synthesized. • Encapsulation of PVP causes surface modification of NiS by reducing surface states. • The synthesized thin films were used as frequency switching material which generates ~ 50 Hz frequency under 1 Sun irradiation. Abstract: Polyvinylpyrrolidone (PVP) encapsulated nickel sulfide (NiS) thin films have been synthesized electrochemically from aqueous solution of hydrated nickel chloride (NiCl₂, 6H₂O), thioacetamide (CH₃C(S) NH₂) (TAA) and polyvinylpyrrolidone (PVP). Surface modification of nickel sulfide (NiS) thin films was achieved by this polymer encapsulation. X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM), field emission scanning electron microscopy (FESEM) and Energy dispersive X-radiation (EDAX) techniques were used for the characterization of thin films. Infrared spectroscopy (IR) confirmed the formation of polymer encapsulated semiconductor. Frequency switching generation study shows that the encapsulated material could be used as a frequency switching device that generates a frequency ~ 50 Hz under 1 Sun illumination. Encapsulation with PVP causes surface modification that reduces the surface states and barrier height. As a result, the width of the depletion region decreases. So the number of electron-hole pairs increases. Consequently, the number of excitons and exciton related emission increases and this leads to reduction of recombination process and shows photo induced

  10. Influence of Temperature Gradient on the Performance of Hard Anodizing Film on Al Alloy%温度梯度降温对铝合金阳极氧化膜性能的影响

    Institute of Scientific and Technical Information of China (English)

    陈朝英; 魏晓伟; 王建; 魏德超

    2012-01-01

    The hard anodic oxidation film on 6061 aluminum alloy sheet surface was prepared by a self-made hard anodic oxidation device under the conditions of large temperature gradient along the direction of aluminum matrix.The oxide film morphology,hardness and thickness were observed and analyzed.The results showed that after hard anodizing the aluminium sheet the film quality was greatly improved,the thickness,hardness and uniformity of hard anodic oxide film prepared with temperature gradient method were far superior to that of the traditional hard anodic oxide film.%采用自制的硬质阳极氧化装置,在铝合金6061薄板表面沿着铝基体方向形成较大的温度梯度降温条件,对铝板进行硫酸硬质氧化试验。对氧化膜形貌、硬度、膜厚分别进行了观察和分析。结果表明,相同条件下,采用温度梯度法制备的硬质阳极氧化膜,其均匀性、膜的厚度和硬度都大大优于传统的硬质阳极氧化膜,膜的质量得到很大的提高。

  11. Photoelectrode thin film of dye-sensitized solar cell fabricated by anodizing method and spin coating and electrochemical impedance properties of DSSC

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ho, E-mail: f10381@ntut.edu.tw [Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei 10608, Taiwan (China); Chen, Chih-Hao [Department of Thoracic Surgery, Mackay Memorial Hospital, Taipei 10419, Taiwan (China); Graduate Institute of Mechanical and Electrical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan (China); Kao, Mu-Jung [Department of Vehicle Engineering, National Taipei University of Technology, Taipei 10608, Taiwan (China); Chien, Shu-Hua [Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan (China); Chou, Cheng-Yi [Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei 10608, Taiwan (China)

    2013-06-15

    The paper studies the photoelectrode thin film of dye-sensitized solar cell (DSSC) fabricated by anodizing method, explores the structure and properties of the fabricated photoelectrode thin film, measures the photoelectric conversion efficiency of DSSC, and finds the electrochemical impedance properties of DSSCs assembled by photoelectrode thin films in different thicknesses. Besides, in order to increase the specific surface area of nanotubes, this paper deposits TiO{sub 2} nanoparticles (TNP) on the surface of titanium oxide nanotube (TNT). As shown in experimental results, the photoelectric conversion efficiency of the DSSC fabricated by the study rises to 6.5% from the original 5.43% without TnB treatment, with an increase of photoelectric conversion efficiency by 19.7%. In addition, when the photoelectrode thin film is fabricated with mixture of TNTs and TNP in an optimal proportion of 2:8 and the photoelectrode thin film thickness is 15.5 μm, the photoelectric conversion efficiency can reach 7.4%, with an increase of 36.7% from the original photoelectric conversion efficiency at 5.43%. Besides, as found in the results of electrochemical impedance analysis, the DSSC with photoelectrode thin film thickness at 15.5 μm has the lowest charge-conduction resistance (R{sub k}) value 9.276 Ω of recombined electron and conduction resistance (R{sub w}) value 3.25 Ω of electrons in TiO{sub 2}.

  12. Microfluidic anodization of aluminum films for the fabrication of nanoporous lipid bilayer support structures

    Directory of Open Access Journals (Sweden)

    Jaydeep Bhattacharya

    2011-02-01

    Full Text Available Solid state nanoporous membranes show great potential as support structures for biointerfaces. In this paper, we present a technique for fabricating nanoporous alumina membranes under constant-flow conditions in a microfluidic environment. This approach allows the direct integration of the fabrication process into a microfluidic setup for performing biological experiments without the need to transfer the brittle nanoporous material. We demonstrate this technique by using the same microfluidic system for membrane fabrication and subsequent liposome fusion onto the nanoporous support structure. The resulting bilayer formation is monitored by impedance spectroscopy across the nanoporous alumina membrane in real-time. Our approach offers a simple and efficient methodology to investigate the activity of transmembrane proteins or ion diffusion across membrane bilayers.

  13. Microfluidic anodization of aluminum films for the fabrication of nanoporous lipid bilayer support structures.

    Science.gov (United States)

    Bhattacharya, Jaydeep; Kisner, Alexandre; Offenhäusser, Andreas; Wolfrum, Bernhard

    2011-01-01

    Solid state nanoporous membranes show great potential as support structures for biointerfaces. In this paper, we present a technique for fabricating nanoporous alumina membranes under constant-flow conditions in a microfluidic environment. This approach allows the direct integration of the fabrication process into a microfluidic setup for performing biological experiments without the need to transfer the brittle nanoporous material. We demonstrate this technique by using the same microfluidic system for membrane fabrication and subsequent liposome fusion onto the nanoporous support structure. The resulting bilayer formation is monitored by impedance spectroscopy across the nanoporous alumina membrane in real-time. Our approach offers a simple and efficient methodology to investigate the activity of transmembrane proteins or ion diffusion across membrane bilayers.

  14. A silicon nanowire-reduced graphene oxide composite as a high-performance lithium ion battery anode material.

    Science.gov (United States)

    Ren, Jian-Guo; Wang, Chundong; Wu, Qi-Hui; Liu, Xiang; Yang, Yang; He, Lifang; Zhang, Wenjun

    2014-03-21

    Toward the increasing demands of portable energy storage and electric vehicle applications, silicon has been emerging as a promising anode material for lithium-ion batteries (LIBs) owing to its high specific capacity. However, serious pulverization of bulk silicon during cycling limits its cycle life. Herein, we report a novel hierarchical Si nanowire (Si NW)-reduced graphene oxide (rGO) composite fabricated using a solvothermal method followed by a chemical vapor deposition process. In the composite, the uniform-sized [111]-oriented Si NWs are well dispersed on the rGO surface and in between rGO sheets. The flexible rGO enables us to maintain the structural integrity and to provide a continuous conductive network of the electrode, which results in over 100 cycles serving as an anode in half cells at a high lithium storage capacity of 2300 mA h g(-1). Due to its [111] growth direction and the large contact area with rGO, the Si NWs in the composite show substantially enhanced reaction kinetics compared with other Si NWs or Si particles.

  15. Synthesis and electrochemical performance of ruthenium oxide-coated carbon nanofibers as anode materials for lithium secondary batteries

    Science.gov (United States)

    Hyun, Yura; Choi, Jin-Yeong; Park, Heai-Ku; Lee, Chang-Seop

    2016-12-01

    In this study, ruthenium oxide (RuO2) coated carbon nanofibers (CNFs) were synthesized and applied as anode materials of Li secondary batteries. The CNFs were grown on Ni foam via chemical vapor deposition (CVD) method after CNFs/Ni foam was put into the 0.01 M RuCl3 solution. The ruthenium oxide-coated CNFs/Ni foam was dried in a dryer at 80 °C. The morphologies, compositions, and crystal quality of RuO2/CNFs/Ni foam were characterized by SEM, EDS, XRD, Raman spectroscopy, and XPS. The electrochemical characteristics of RuO2/CNFs/Ni foam as anode of Li secondary batteries were investigated using three-electrode cell. The RuO2/CNFs/Ni foam was directly employed as a working electrode without any binder, and lithium foil was used as the counter and reference electrodes. LiClO4 (1 M) was employed as electrolyte and dissolved in a mixture of propylene carbonate (PC): ethylene carbonate (EC) in a 1:1 volume ratio. The galvanostatic charge/discharge cycling and cyclic voltammetry measurements were carried out at room temperature by using a battery tester. In particular, synthesized RuO2/CNFs/Ni foam showed the highest retention rate (47.4%). The initial capacity (494 mAh/g) was reduced to 234 mAh/g after 30 cycles.

  16. Characterisation of ferroelectric bulk materials and thin films

    CERN Document Server

    Cain, Markys G

    2014-01-01

    This book presents a comprehensive review of the most important methods used in the characterisation of piezoelectric, ferroelectric and pyroelectric materials. It covers techniques for the analysis of bulk materials and thick and thin film materials and devices. There is a growing demand by industry to adapt and integrate piezoelectric materials into ever smaller devices and structures. Such applications development requires the joint development of reliable, robust, accurate and - most importantly - relevant and applicable measurement and characterisation methods and models. In the past f

  17. Effect of tar fractions from coal gasification on nickel-yttria stabilized zirconia and nickel-gadolinium doped ceria solid oxide fuel cell anode materials

    Science.gov (United States)

    Lorente, E.; Berrueco, C.; Millan, M.; Brandon, N. P.

    2013-11-01

    The allowable tar content in gasification syngas is one of the key questions for the exploitation of the full potential of fuel cell concepts with integrated gasification systems. A better understanding of the interaction between tars and the SOFC anodes which leads to carbon formation and deposition is needed in order to design systems where the extent of gas cleaning operations is minimized. Model tar compounds (toluene, benzene, naphthalene) have been used in experimental studies to represent those arising from biomass/coal gasification. However, the use of toluene as a model tar overestimates the negative impact of a real gasification tar on SOFC anode degradation associated with carbon formation. In the present work, the effect of a gasification tar and its distillation fractions on two commercially available fuel cell anodes, Ni/YSZ (yttria stabilized zirconia) and Ni/CGO (gadolinium doped ceria), is reported. A higher impact of the lighter tar fractions was observed, in terms of more carbon formation on the anodes, in comparison with the whole tar sample. The characterization of the recovered tars after contact with the anode materials revealed a shift towards a heavier molecular weight distribution, reinforcing the view that these fractions have reacted on the anode.

  18. Synthesis of thin films and materials utilizing a gaseous catalyst

    Science.gov (United States)

    Morse, Daniel E; Schwenzer, Birgit; Gomm, John R; Roth, Kristian M; Heiken, Brandon; Brutchey, Richard

    2013-10-29

    A method for the fabrication of nanostructured semiconducting, photoconductive, photovoltaic, optoelectronic and electrical battery thin films and materials at low temperature, with no molecular template and no organic contaminants. High-quality metal oxide semiconductor, photovoltaic and optoelectronic materials can be fabricated with nanometer-scale dimensions and high dopant densities through the use of low-temperature biologically inspired synthesis routes, without the use of any biological or biochemical templates.

  19. Thin Film Composite Materials, Phase 2

    Science.gov (United States)

    1987-01-01

    were Kevlar coated with silicone, EPDM , or neoprene rubber, with the following results: 1. Tensile testing of coated Kevlar fabric is very difficult...materials. 2. A method was developed for measuring water vapor permeability. Neoprene and EPDM are promising as coatings with good water resistance; however...control the folding of the fabric, since the diameters of the spiral channel will be fixed. Because of the stability imparted by the channel, it is

  20. MATERIAL AND PROCESS DEVELOPMENT LEADING TO ECONOMICAL HIGH-PERFORMANCE THIN-FILM SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Jie Guan; Nguyen Minh

    2003-10-01

    This document summarizes the technical progress from April to September 2003 for the program, Material and Process Development Leading to Economical High-Performance Thin-Film Solid Oxide Fuel Cells, contract number DE-AC26-00NT40711. Characteristics of doped lanthanum gallate (LSGMF) powder suitable for thin electrolyte fabrication have been defined. Bilayers with thin LSGMF electrolyte supported on an anode were fabricated and the fabrication process was improved. Preliminary performance was characterized. High performance cathode material Sr{sub 0.5}Sm{sub 0.5}CoO{sub 3} has been down-selected and is being optimized by modifying materials characteristics and processing parameters. The selected cathode exhibited excellent performance with cathode polarization of {approx}0.23 ohm-cm{sup 2} at 600 C.

  1. The prospects of phosphorene as an anode material for high-performance lithium-ion batteries: a fundamental study

    Science.gov (United States)

    Zhang, Congyan; Yu, Ming; Anderson, George; Ravinath Dharmasena, Ruchira; Sumanasekera, Gamini

    2017-02-01

    To completely understand lithium adsorption, diffusion, and capacity on the surface of phosphorene and, therefore, the prospects of phosphorene as an anode material for high-performance lithium-ion batteries (LIBs), we carried out density-functional-theory calculations and studied the lithium adsorption energy landscape, the lithium diffusion mobility, the lithium intercalation, and the lithium capacity of phosphorene. We also carried out, for the very first time, experimental measurement of the lithium capacity of phosphorene. Our calculations show that the lithium diffusion mobility along the zigzag direction in the valley of phosphorene was about 7 to 11 orders of magnitude faster than that along the other directions, indicating its ultrafast and anisotropic diffusivity. The lithium intercalation in phosphorene was studied by considering various Li n P16 configurations (n = 1-16) including single-side and double-side adsorptions. We found that phosphorene could accommodate up to a ratio of one Li per P atom (i.e. Li16P16). In particular, we found that, even at a high Li concentration (e.g. x = 1 in Li x P), there was no lithium clustering, and the structure of phosphorene (when fractured) is reversible during lithium intercalation. The theoretical value of the lithium capacity for a monolayer phosphorene is predicted to be above 433 mAh g-1, depending on whether Li atoms are adsorbed on the single side or the double side of phosphorene. Our experimental measurement of the lithium capacity for few-layer phosphorene networks shows a reversible stable value of ˜453 mAh g-1 even after 50 cycles. Our results clearly show that phosphorene, compared to graphene and other two-dimensional materials, has great promise as a novel anode material for high-performance LIBs.

  2. Synthesis by anodic-spark deposition of Ca- and P-containing films on pure titanium and their biological response

    Energy Technology Data Exchange (ETDEWEB)

    Banakh, Oksana, E-mail: oksana.banakh@he-arc.ch [Haute Ecole Arc Ingénierie (HES-SO), Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland); Journot, Tony; Gay, Pierre-Antoine; Matthey, Joël; Csefalvay, Catherine [Haute Ecole Arc Ingénierie (HES-SO), Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland); Kalinichenko, Oleg [Ukrainian State University of Chemical Technology (SHEI), Gagarin av. 8, Dnepropetrovsk, UA-49005 (Ukraine); Sereda, Olha [Centre Suisse d’Electronique et de Microtechnique (CSEM), Rue Jaquet-Droz 1, CH-2000 Neuchâtel (Switzerland); Moussa, Mira; Durual, Stéphane [Laboratory of Biomaterials, University of Geneva, rue Barthelemy Menn 19, CH-1205 Geneva (Switzerland); Snizhko, Lyubov [Ukrainian State University of Chemical Technology (SHEI), Gagarin av. 8, Dnepropetrovsk, UA-49005 (Ukraine)

    2016-08-15

    Highlights: • ​CP-4 Ti was treated by anodic spark oxidation in the electrolyte containing Ca and P ions by varying process time and electrolyte concentration. • Ca/P ratio in layers is 0.23–0.47, much lower than in hydroxyapatites (1.67). It means coatings should be resorbable in a biological medium • After immersion in SBF, Ca and P content in layers decrease. Ca and P loss occurs faster in thin layers than in thicker coatings. • The biological response of the samples suggests their excellent biocompatibility and even stimulating effects on osteoblasts proliferation. - Abstract: The purpose of this work is to characterize the anodized layers formed on titanium by anodic-spark deposition in an electrolyte containing Ca and P ions, Ca{sub 3}(PO{sub 4}){sub 2}, studied for the first time. The oxidation experiments were performed at different periods of time and using different concentrations of electrolyte. The influence of the process parameters (time of electrolysis and electrolyte concentration) on the surface morphology and chemical composition of the anodized layers was studied. It has been found that it is possible to incorporate Ca and P into the growing layer. A response of the anodized layers in a biological medium was evaluated by their immersion in a simulated body fluid. An enrichment of titanium and a simultaneous loss of calcium and phosphorus in the layer after immersion tests indicate that these coatings should be bioresorbable in a biological medium. Preliminary biological assays were performed on some anodized layers in order to assess their biocompatibility with osteoblast cells. The cell proliferation on one selected anodized sample was assessed up to 21 days after seeding. The preliminary results suggest excellent biocompatibility properties of anodized coatings.

  3. Mesoporous Carbon-Tin Nanocomposites as Anode Materials for Li-ion Battery

    Institute of Scientific and Technical Information of China (English)

    Z.W.Zhao; Z.P.Guo; P.Yao; H.K.Liu

    2008-01-01

    A new mesoporous carbon-tin (MC-Sn) nanocomposite has been successfully prepared via a two-step method. From the transmission electron microscopy (TEM) observations, the tin nanoparticles were decorated on the as-prepared mesoporous carbons. The mesoprous structure of the carbon can effectively buffer the volume changes during the Li-Sn alloying and de-alloying cycles. The as-prepared MC/Sn nanocomposite electrodes exhibited extremely good cycling stability, with the specific capacity of Sn in the composite electrode calculated to be 959.7 mAh-g-1, which amounts to an impressive 96.9% of the theoretical value (990 mAh·g-1). The reversible capacity after 200 cycles is 96.1% of the first cycle reversible capacity, i.e., the capacity fade rate is only 0.0195% per cycle, which is even better than that of commercial graphite-based anodes.

  4. Cellulose Nanofibril Film as a Piezoelectric Sensor Material.

    Science.gov (United States)

    Rajala, Satu; Siponkoski, Tuomo; Sarlin, Essi; Mettänen, Marja; Vuoriluoto, Maija; Pammo, Arno; Juuti, Jari; Rojas, Orlando J; Franssila, Sami; Tuukkanen, Sampo

    2016-06-22

    Self-standing films (45 μm thick) of native cellulose nanofibrils (CNFs) were synthesized and characterized for their piezoelectric response. The surface and the microstructure of the films were evaluated with image-based analysis and scanning electron microscopy (SEM). The measured dielectric properties of the films at 1 kHz and 9.97 GHz indicated a relative permittivity of 3.47 and 3.38 and loss tangent tan δ of 0.011 and 0.071, respectively. The films were used as functional sensing layers in piezoelectric sensors with corresponding sensitivities of 4.7-6.4 pC/N in ambient conditions. This piezoelectric response is expected to increase remarkably upon film polarization resulting from the alignment of the cellulose crystalline regions in the film. The CNF sensor characteristics were compared with those of polyvinylidene fluoride (PVDF) as reference piezoelectric polymer. Overall, the results suggest that CNF is a suitable precursor material for disposable piezoelectric sensors, actuators, or energy generators with potential applications in the fields of electronics, sensors, and biomedical diagnostics.

  5. Research progress in transition metal oxides based on conversion mechanism as the anode materials for Li-ion batteries%转化型过渡金属氧化物负极材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    曾晖; 王强; 王康平; 宋金保

    2014-01-01

    综述了近年来过渡金属氧化物 MxOy (M= Fe,Ni,Co,Cu)作为锂离子电池负极材料在锂离子电池中的应用。我们分别将过渡金属氧化物的两种形态(粉体和薄膜),与电化学性能之间的关联性进行了总结和探讨,并对过渡金属氧化物作为锂离子电池负极材料的发展前景进行了展望。%In recent years,research progress on transition metal oxides MxOy(M= Fe,Ni,Co,Cu) as anode materials for lithium ion batteries was reviewed.Emphasis is placed on the generaliza-tion and discussion of the relationship between the two status (powder and films )and electro-chemical properties of transition metal oxides materials.And the development prospect of transi-tion metal oxides as anode materials is also reviewed.

  6. Vertically oriented Ti-Fe-O nanotube array films: toward a useful material architecture for solar spectrum water photoelectrolysis.

    Science.gov (United States)

    Mor, Gopal K; Prakasam, Haripriya E; Varghese, Oomman K; Shankar, Karthik; Grimes, Craig A

    2007-08-01

    In an effort to obtain a material architecture suitable for high-efficiency visible spectrum water photoelectrolysis, herein we report on the fabrication and visible spectrum (380-650 nm) photoelectrochemical properties of self-aligned, vertically oriented Ti-Fe-O nanotube array films. Ti-Fe metal films of variable composition, iron content ranging from 69% to 3.5%, co-sputtered onto FTO-coated glass are anodized in an ethylene glycol + NH4F electrolyte. The resulting amorphous samples are annealed in oxygen at 500 degrees C, resulting in nanotubes composed of a mixed Ti-Fe-O oxide. Some of the iron goes into the titanium lattice substituting titanium ions, and the rest either forms alpha-Fe2O3 crystallites or remains in the amorphous state. Depending upon the Fe content, the band gap of the resulting films ranges from about 380 to 570 nm. The Ti-Fe oxide nanotube array films are utilized in solar spectrum water photoelectrolysis, demonstrating 2 mA/cm2 under AM 1.5 illumination with a sustained, time-energy normalized hydrogen evolution rate by water splitting of 7.1 mL/W.hr in a 1 M KOH solution with a platinum counter electrode under an applied bias of 0.7 V. The surface morphology, structure, elemental analysis, optical, and photoelectrochemical properties of the Ti-Fe oxide nanotube array films are considered.

  7. Spinel lithium titanate (Li4Ti5O12) as novel anode material for room-temperature sodium-ion battery

    Institute of Scientific and Technical Information of China (English)

    Zhao Liang; Pan Hui-Lin; Hu Yong-Sheng; Li Hong; Chen Li-Quan

    2012-01-01

    This is the first time that a novel anode material,spinel Li4Ti5O12 which is well known as a “zero-strain” anode material for lithium storage,has been introduced for sodium-ion battery.The Li4Ti5O12 shows an average Na storage voltage of about 1.0 V and a reversible capacity of about 145 mAh/g,thereby making it a promising anode for sodiumion battery.Ex-situ X-ray diffraction (XRD) is used to investigate the structure change in the Na insertion/deinsertion process.Based on this,a possible Na storage mechanism is proposed.

  8. Multilayer Thin Films Sequential Assembly of Nanocomposite Materials

    CERN Document Server

    Decher, Gero

    2012-01-01

    This second, comprehensive edition of the pioneering book in this field has been completely revised and extended, now stretching to two volumes. The result is a comprehensive summary of layer-by-layer assembled, truly hybrid nanomaterials and thin films, covering organic, inorganic, colloidal, macromolecular and biological components, plus the assembly of nanoscale films derived from them on surfaces. Praise for the first edition: "... highly recommended to anyone interested in the field... and to scientists and researchers active in materials development..." –Polymer News With contri

  9. DESIGNING OF POLYMERIC PACKAGING FILM MATERIALS WITH THE BARRIER PROPERTIES

    OpenAIRE

    Колосов, Олександр Євгенович; Сідоров, Дмитро Едуардович; Малецький, Сергій Віталійович

    2016-01-01

    The basic types of interactions for packaged food product and packaging that may occur between the polymer film packaging material and the produc are analyzed. It is noted that the most simple to implement isolation of the internal space of the polymer film packaging from the environment. In this package of the insulated space can be removed by air, in particular, evacuation, or replaced with an inert gas or inert gas mixture. It is noted that the permeability of gases and gas mixtures by non...

  10. FMR study of thin film FeGe skyrmionic material

    Science.gov (United States)

    Bhallamudi, Vidya P.; Page, Michael R.; Gallagher, James; Purser, Carola; Schulze, Joseph; Yang, Fengyuan; Hammel, P. Chris

    Magnetic Skyrmions have attracted intense interest due to their novel topological properties and the potential for energy efficient computing. Magnetic dynamics play an important part in enabling some of these functionalities. Understanding these dynamics can shed light on the interplay of the various magnetic interactions that exist in these materials and lead to a rich magnetic phase diagram, including the Skyrmion phase. We have grown phase-pure FeGe epitaxial films on Si (111) and studied them using ferromagnetic resonance (FMR). FeGe has one of the highest recorded skyrmion transition temperatures, close to room temperature, and thin films are known to further stabilize the Skyrmion phase in the magnetic field-temperature space. We have performed cavity-based single frequency FMR from liquid nitrogen to room temperature on 120 nm thick films in both in-plane and out-of-plane geometries. The resulting complex spectra are consistent with those reported in literature for the bulk material and can be understood in terms of a conical model for the magnetism. Variable temperature broadband spectroscopy and measurements on thinner films, to better identify the various magnetic phases and their dynamic behavior, are ongoing and their progress will be discussed. Funding for this research was provided by the Center for Emergent Materials: an NSF MRSEC under Award Number DMR-1420451.

  11. Effect of carbon coating on electrochemical performance of hard carbons as anode materials for lithium-ion batteries

    Science.gov (United States)

    Lee, Jong-Hyuk; Lee, Heon-Young; Oh, Seh-Min; Lee, Seo-Jae; Lee, Ki-Young; Lee, Sung-Man

    Surface modification by a soft-carbon coating is used to improve the electrochemical performance of hard carbons as the negative-electrode (anode) material in lithium-ion batteries. The coating process involves simple heat-treatment of a mixture of coal-tar pitch and hard carbon powders at 1000 °C. The carbon coating significantly reduces the reaction of lithium with surface functional groups or absorbed species caused by air exposure. This is attributed to the effective suppression of the diffusion of both air and water into the hard carbon by the soft-carbon coating, and the better resistance of soft carbon to air. As a result, the charge-discharge coulombic efficiency during cycling, as well as during the first cycle, is improved.

  12. Carbon-coated Ni 20Si 80 alloy-graphite composite as an anode material for lithium-ion batteries

    Science.gov (United States)

    Lee, Heon-Yong; Kim, Young-Lae; Hong, Moon-Ki; Lee, Sung-Man

    A carbon-coated Ni 20Si 80 alloy-graphite composite has been studied as the anode for lithium-ion batteries. The composite is prepared by simple heat-treatment of a mixture of coal tar pitch and a Ni 20Si 80-graphite composite at 900 °C and under argon. The Ni 20Si 80 alloy powders are synthesized by mechanical alloying. The composite demonstrates promising electrochemical properties such as high reversible capacity, excellent cycle performance, and sufficiently high initial charge-discharge coulombic efficiency. This suggests buffering and conductive actions on the main active material, viz., Ni 20Si 80 alloy, of the graphite. These two effects are strongly enhanced by the carbon coating treatment.

  13. A novel ZnO@Ag@Polypyrrole hybrid composite evaluated as anode material for zinc-based secondary cell.

    Science.gov (United States)

    Huang, Jianhang; Yang, Zhanhong; Feng, Zhaobin; Xie, Xiaoe; Wen, Xing

    2016-04-14

    A novel ZnO@Ag@Polypyrrole nano-hybrid composite has been synthesized with a one-step approach, in which silver-ammonia complex ion serves as oxidant to polymerize the pyrrole monomer. X-ray diffraction (XRD) and infrared spectroscopy (IR) show the existence of metallic silver and polypyrrole. The structure of nano-hybrid composites are characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), which demonstrates that the surface of ZnO is decorated with nano silver grain coated with polypyrrole. When evaluated as anode material, the silver grain and polypyrrole layer not only suppress the dissolution of discharge product, but also helps to uniform electrodeposition due to substrate effect and its good conductivity, thus shows better cycling performance than bare ZnO electrode does.

  14. Effects of sulfur doping on graphene-based nanosheets for use as anode materials in lithium-ion batteries

    Science.gov (United States)

    Yun, Young Soo; Le, Viet-Duc; Kim, Haegyeom; Chang, Sung-Jin; Baek, Seung Jae; Park, Sungjin; Kim, Byung Hoon; Kim, Yong-Hyun; Kang, Kisuk; Jin, Hyoung-Joon

    2014-09-01

    Graphene-based nanosheets (GNS) have been studied for use in electrochemical energy storage devices. A deeper understanding about the system is required for achieving enhanced power output and high energy storage. The effects of sulfur doping on the electrochemical properties of GNS are studied for their use as an anode material in lithium-ion batteries. Sulfur doping in GNS contributes to the high specific capacity by providing more lithium storage sites due to Faradaic reactions. In addition, superior rate performance of sulfur-doped GNS (S-GNS) is achieved through the improved electrical conductivity of S-GNS (1743 S m-1), which is two orders of magnitude higher than that of GNS (32 S m-1). In addition, good cyclic stability of S-GNS is maintained even after 500 cycles at a high current density of 1488 mA g-1 (4 C).

  15. One-pot facile synthesis of CuS/graphene composite as anode materials for lithium ion batteries

    Science.gov (United States)

    Tao, Hua-Chao; Yang, Xue-Lin; Zhang, Lu-Lu; Ni, Shi-Bing

    2014-11-01

    CuS/graphene composite has been synthesized by the one-pot hydrothermal method using thiourea as the sulfur source and reducing agent. The formation of CuS nanoparticles and the reduction of graphene oxide occur simultaneously during the hydrothermal process, which enables a uniform dispersion of CuS nanoparticles on the graphene nanosheets. The electrochemical performance of CuS/graphene composite was studied as anode materials for lithium ion batteries. The obtained CuS/graphene composite exhibits a relative high reversible capacity and good cycling stability. The good electrochemical performance of CuS/graphene composite can be attributed to graphene, which improves the electronic conductivity of composite and enhances the interfacial stability of electrode and electrolyte.

  16. Enhancement of Electrochemical Performance by the Oxygen Vacancies in Hematite as Anode Material for Lithium-Ion Batteries

    Science.gov (United States)

    Zeng, Peiyuan; Zhao, Yueying; Lin, Yingwu; Wang, Xiaoxiao; Li, Jianwen; Wang, Wanwan; Fang, Zhen

    2017-01-01

    The application of hematite in lithium-ion batteries (LIBs) has been severely limited because of its poor cycling stability and rate performance. To solve this problem, hematite nanoparticles with oxygen vacancies have been rationally designed by a facile sol-gel method and a sequential carbon-thermic reduction process. Thanks to the existence of oxygen vacancies, the electrochemical performance of the as-obtained hematite nanoparticles is greatly enhancing. When used as the anode material in LIBs, it can deliver a reversible capacity of 1252 mAh g-1 at 2 C after 400 cycles. Meanwhile, the as-obtained hematite nanoparticles also exhibit excellent rate performance as compared to its counterparts. This method not only provides a new approach for the development of hematite with enhanced electrochemical performance but also sheds new light on the synthesis of other kinds of metal oxides with oxygen vacancies.

  17. High capacity and high rate capability of nanostructured CuFeO 2 anode materials for lithium-ion batteries

    Science.gov (United States)

    Lu, Lin; Wang, Jia-Zhao; Zhu, Xue-Bin; Gao, Xuan-Wen; Liu, Hua-Kun

    Non-toxic, cheap, nanostructured ternary transition metal oxide CuFeO 2 was synthesised using a simple sol-gel method at different temperatures. The effects of the processing temperature on the particle size and electrochemical performance of the nanostructured CuFeO 2 were investigated. The electrochemical results show that the sample synthesised at 650 °C shows the best cycling performance, retaining a specific capacity of 475 mAh g -1 beyond 100 cycles, with a capacity fading of less than 0.33% per cycle. The electrode also exhibits good rate capability in the range of 0.5 C-4 C. At the high rate of 4 C, the reversible capacity of CuFeO 2 is around 170 mAh g -1. It is believed that the ternary transition metal oxide CuFeO 2 is quite acceptable compared with other high performance nanostructured anode materials.

  18. 2D sandwich-like sheets of iron oxide grown on graphene as high energy anode material for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Qunting; Feng, Xinliang [College of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 (China); Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz (Germany); Yang, Shubin [Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz (Germany)

    2011-12-08

    2D sandwich-like sheets of iron oxide grown on graphene as high energy anode material for supercapacitors are prepared from the direct growth of FeOOH nanorods on the surface of graphene and the subsequent electrochemical transformation of FeOOH to Fe{sub 3}O{sub 4}. The Fe{sub 3}O{sub 4} rate at RGO nanocomposites exhibit superior capacitance (326 F g{sup -1}), high energy density (85 Wh kg{sup -1}), large power, and good cycling performance in 1 mol L{sup -1} LiOH solution. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Spindle-like mesoporous α-Fe₂O₃ anode material prepared from MOF template for high-rate lithium batteries.

    Science.gov (United States)

    Xu, Xiaodong; Cao, Ruiguo; Jeong, Sookyung; Cho, Jaephil

    2012-09-12

    Spindle-like porous α-Fe(2)O(3) was prepared from an iron-based metal organic framework (MOF) template. When tested as anode material for lithium batteries (LBs), this spindle-like porous α-Fe(2)O(3) shows greatly enhanced performance of Li storage. The particle with a length and width of ∼0.8 and ∼0.4 μm, respectively, was composed of clustered Fe(2)O(3) nanoparticles with sizes of <20 nm. The capacity of the porous α-Fe(2)O(3) retained 911 mAh g(-1) after 50 cycles at a rate of 0.2 C. Even when cycled at 10 C, comparable capacity of 424 mAh g(-1) could be achieved.

  20. A novel ZnO@Ag@Polypyrrole hybrid composite evaluated as anode material for zinc-based secondary cell

    Science.gov (United States)

    Huang, Jianhang; Yang, Zhanhong; Feng, Zhaobin; Xie, Xiaoe; Wen, Xing

    2016-04-01

    A novel ZnO@Ag@Polypyrrole nano-hybrid composite has been synthesized with a one-step approach, in which silver-ammonia complex ion serves as oxidant to polymerize the pyrrole monomer. X-ray diffraction (XRD) and infrared spectroscopy (IR) show the existence of metallic silver and polypyrrole. The structure of nano-hybrid composites are characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), which demonstrates that the surface of ZnO is decorated with nano silver grain coated with polypyrrole. When evaluated as anode material, the silver grain and polypyrrole layer not only suppress the dissolution of discharge product, but also helps to uniform electrodeposition due to substrate effect and its good conductivity, thus shows better cycling performance than bare ZnO electrode does.

  1. Enhancement of Electrochemical Performance by the Oxygen Vacancies in Hematite as Anode Material for Lithium-Ion Batteries.

    Science.gov (United States)

    Zeng, Peiyuan; Zhao, Yueying; Lin, Yingwu; Wang, Xiaoxiao; Li, Jianwen; Wang, Wanwan; Fang, Zhen

    2017-12-01

    The application of hematite in lithium-ion batteries (LIBs) has been severely limited because of its poor cycling stability and rate performance. To solve this problem, hematite nanoparticles with oxygen vacancies have been rationally designed by a facile sol-gel method and a sequential carbon-thermic reduction process. Thanks to the existence of oxygen vacancies, the electrochemical performance of the as-obtained hematite nanoparticles is greatly enhancing. When used as the anode material in LIBs, it can deliver a reversible capacity of 1252 mAh g(-1) at 2 C after 400 cycles. Meanwhile, the as-obtained hematite nanoparticles also exhibit excellent rate performance as compared to its counterparts. This method not only provides a new approach for the development of hematite with enhanced electrochemical performance but also sheds new light on the synthesis of other kinds of metal oxides with oxygen vacancies.

  2. Synthesis of Hierarchical CoO Nano/Microstructures as Anode Materials for Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Dan Qin

    2014-01-01

    Full Text Available Hierarchical CoO nano/microstructures are synthesized via a hydrothermal method and a subsequent annealed process. When evaluated for use in lithium-ion batteries, hierarchical CoO nano/microstructures show a high initial discharge capacity of 1370 mAh/g and a high reversible capacity of 1148 mAh/g over 20 cycles at a current density of 100 mA/g. Superior rate performance with coulombic efficiency of about 100% upon galvanostatic cycling is also revealed. The excellent electrochemical properties of hierarchical CoO nano/microstructures make it a promising alternative anode material for high power lithium-ion batteries applications.

  3. Novel Ag@Nitrogen-doped Porous Carbon Composite with High Electrochemical Performance as Anode Materials for Lithium-ion Batteries

    Science.gov (United States)

    Chen, Yuqing; Li, Jintang; Yue, Guanghui; Luo, Xuetao

    2017-07-01

    A novel Ag@nitrogen-doped porous carbon (Ag-NPC) composite was synthesized via a facile hydrothermal method and applied as an anode material in lithium-ion batteries (LIBs). Using this method, Ag nanoparticles (Ag NPs) were embedded in NPC through thermal decomposition of AgNO3 in the pores of NPC. The reversible capacity of Ag-NPC remained at 852 mAh g-1 after 200 cycles at a current density of 0.1 A g-1, showing its remarkable cycling stability. The enhancement of the electrochemical properties such as cycling performance, reversible capacity and rate performance of Ag-NPC compared to the NPC contributed to the synergistic effects between Ag NPs and NPC.

  4. Facile mass production of nanoporous SnO2 nanosheets as anode materials for high performance lithium-ion batteries.

    Science.gov (United States)

    Wei, Wenli; Du, Pengcheng; Liu, Dong; Wang, Hongxing; Liu, Peng

    2017-10-01

    Facile one-step ultrasonic-assisted chemical precipitation strategy has been developed for the mass production of SnO2 nanomaterials with different morphologies. As anode material for lithium-ion batteries, the nanoporous SnO2 nanosheets exhibited an extremely high initial specific capacity of 2231mAh/g in comparison with 1242mAh/g of the SnO2 microcrystals and 1244mAh/g of the nanoporous SnO2 nanoflowers. Meanwhile the nanoporous SnO2 nanosheet electrode displayed a specific capacity of 688mAh/g after 60 cycles at 0.2 A/g current density and an extraordinary capacity retention of 224mAh/g at a current density of 8A/g (approximately 10 C) owing to a huge increase of Li(+) diffusion coefficient. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Electrospun fibers for high performance anodes in microbial fuel cells. Optimizing materials and architecture

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shuiliang

    2010-04-15

    A novel porous conducting nanofiber mat (PCNM) with nanostructured polyaniline (nanoPANi) on the fiber surface was successfully prepared by simple oxidative polymerization. The composite PCNM displayed a core/shell structure with highly rough surface. The thickness and the morphology of PANi layer on the electrospun polyamide (PA) fiber surface could be controlled by varying aniline concentration and temperature. The combination of the advantages of electrospinning technique and nanostructured PANi, let the PA/PANi composite PCNM possess more than five good properties, i.e. high conductivity of 6.759 S.m{sup -1}, high specific surface area of 160 m2.g{sup -1}, good strength of 82.88 MPa for mat and 161.75 MPa for highly aligned belts, good thermal properties with 5% weight loss temperature up to 415 C and excellent biocompatibility. In the PA/PANi composite PCNM, PANi is the only conducting component, its conductivity of 6.759 S.m{sup -1} which is measured in dry-state, is not enough for electrode. Moreover, the conductivity decreases in neutral pH environment due to the de-doping of proton. However, the method of spontaneous growth of nanostructured PANi on electrospun fiber mats provides an effective method to produce porous electrically conducting electrospun fiber mats. The combination advantages of nanostructured PANi with the electrospun fiber mats, extends the applications of PANi and electrospun nanofibers, such as chemical- and bio-sensors, actuators, catalysis, electromagnetic shielding, corrosion protection, separation membranes, electro-optic devices, electrochromic devices, tissue engineering and many others. The electrical conductivity of electrospun PCNM with PANi as the only conducting component is too low for application of as anode in microbial fuel cells (MFCs). So, we turn to electrospun carbon fiber due to its high electrical conductivity and environmental stability. The current density is greatly dependent on the microorganism density of anode

  6. Electrospun fibers for high performance anodes in microbial fuel cells. Optimizing materials and architecture

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shuiliang

    2010-04-15

    A novel porous conducting nanofiber mat (PCNM) with nanostructured polyaniline (nanoPANi) on the fiber surface was successfully prepared by simple oxidative polymerization. The composite PCNM displayed a core/shell structure with highly rough surface. The thickness and the morphology of PANi layer on the electrospun polyamide (PA) fiber surface could be controlled by varying aniline concentration and temperature. The combination of the advantages of electrospinning technique and nanostructured PANi, let the PA/PANi composite PCNM possess more than five good properties, i.e. high conductivity of 6.759 S.m{sup -1}, high specific surface area of 160 m2.g{sup -1}, good strength of 82.88 MPa for mat and 161.75 MPa for highly aligned belts, good thermal properties with 5% weight loss temperature up to 415 C and excellent biocompatibility. In the PA/PANi composite PCNM, PANi is the only conducting component, its conductivity of 6.759 S.m{sup -1} which is measured in dry-state, is not enough for electrode. Moreover, the conductivity decreases in neutral pH environment due to the de-doping of proton. However, the method of spontaneous growth of nanostructured PANi on electrospun fiber mats provides an effective method to produce porous electrically conducting electrospun fiber mats. The combination advantages of nanostructured PANi with the electrospun fiber mats, extends the applications of PANi and electrospun nanofibers, such as chemical- and bio-sensors, actuators, catalysis, electromagnetic shielding, corrosion protection, separation membranes, electro-optic devices, electrochromic devices, tissue engineering and many others. The electrical conductivity of electrospun PCNM with PANi as the only conducting component is too low for application of as anode in microbial fuel cells (MFCs). So, we turn to electrospun carbon fiber due to its high electrical conductivity and environmental stability. The current density is greatly dependent on the microorganism density of anode

  7. Nb{sub 2}O{sub 5} hollow nanospheres as anode material for enhanced performance in lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Sasidharan, Manickam [Department of Chemistry, Faculty of Science and Engineering, Saga University, 1 Honjo-machi, Saga 840-8502 (Japan); Gunawardhana, Nanda [Advanced Research Center, Saga University, 1341 Yoga-machi, Saga 840-0047 (Japan); Yoshio, Masaki, E-mail: yoshio@cc.saga-u.ac.jp [Advanced Research Center, Saga University, 1341 Yoga-machi, Saga 840-0047 (Japan); Nakashima, Kenichi, E-mail: nakashik@cc.saga-u.ac.jp [Department of Chemistry, Faculty of Science and Engineering, Saga University, 1 Honjo-machi, Saga 840-8502 (Japan)

    2012-09-15

    Graphical abstract: Nb{sub 2}O{sub 5} hollow nanosphere constructed electrode delivers high capacity of 172 mAh g{sup −1} after 250 cycles and maintains structural integrity and excellent cycling stability. Highlights: ► Nb{sub 2}O{sub 5} hollow nanospheres synthesis was synthesized by soft-template. ► Nb{sub 2}O{sub 5} hollow nanospheres were investigated as anode material in Li-ion battery. ► Nanostructured electrode delivers high capacity of 172 mAh g{sup −1} after 250 cycles. ► The electrode maintains the structural integrity and excellent cycling stability. ► Nanosized shell domain facilitates fast lithium intercalation/deintercalation. -- Abstract: Nb{sub 2}O{sub 5} hollow nanospheres of average diameter ca. ∼29 nm and hollow cavity size ca. 17 nm were synthesized using polymeric micelles with core–shell–corona architecture under mild conditions. The hollow particles were thoroughly characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermal (TG/DTA) and nitrogen adsorption analyses. Thus obtained Nb{sub 2}O{sub 5} hollow nanospheres were investigated as anode materials for lithium ion rechargeable batteries for the first time. The nanostructured electrode delivers high capacity of 172 mAh g{sup −1} after 250 cycles of charge/discharge at a rate of 0.5 C. More importantly, the hollow particles based electrodes maintains the structural integrity and excellent cycling stability even after exposing to high current density 6.25 A g{sup −1}. The enhanced electrochemical behavior is ascribed to hollow cavity coupled with nanosized Nb{sub 2}O{sub 5} shell domain that facilitates fast lithium intercalation/deintercalation kinetics.

  8. Synthesis of aluminum oxy-hydroxide nanofibers from porous anodic alumina.

    Science.gov (United States)

    Jha, Himendra; Kikuchi, Tatsuya; Sakairi, Masatoshi; Takahashi, Hideaki

    2008-10-01

    A novel method for the synthesis of aluminum oxy-hydroxide nanofibers from a porous anodic oxide film of aluminum is demonstrated. In the present method, the porous anodic alumina not only acts as a template, but also serves as the starting material for the synthesis. The porous anodic alumina film is hydrothermally treated for pore-sealing, which forms aluminum oxy-hydroxide inside the pores of the oxide film as well as on the surface of the film. The hydrothermally sealed porous oxide film is immersed in the sodium citrate solution, which selectively etches the porous aluminum oxide from the film, leaving the oxy-hydroxide intact. The method is simple and gives highly uniform aluminum oxy-hydroxide nanofibers. Moreover, the diameter of the nanofibers can be controlled by controlling the pore size of the porous anodic alumina film, which depends on the anodizing conditions. Nanofibers with diameters of about 38-85 nm, having uniform shape and size, were successfully synthesized using the present method.

  9. Composite Materials and Films Based on Melanins, Polydopamine, and Other Catecholamine-Based Materials

    Directory of Open Access Journals (Sweden)

    Vincent Ball

    2017-07-01

    Full Text Available Polydopamine (PDA is related to eumelanins in its composition and structure. These pigments allow the design, inspired by natural materials, of composite nanoparticles and films for applications in the field of energy conversion and the design of biomaterials. This short review summarizes the main advances in the design of PDA-based composites with inorganic and organic materials.

  10. Si-SiOx-Al2O3 nanocomposites as high-capacity anode materials for Li-ion batteries

    Science.gov (United States)

    Kim, Kyungbae; Kim, Moon-Soo; Choi, Hyerang; Min, Kyeong-Sik; Kim, Ki-Doo; Kim, Jae-Hun

    2017-03-01

    Nanocrystalline Si-embedded SiOx-Al2O3 composite materials were synthesized by a high-energy mechanical milling method, and their potential as an anode material for Li-ion batteries was examined. The starting materials were amorphous SiO2 and Al metal powders. To increase the initial coulombic efficiency of the SiO2-based electrode materials, the amorphous SiO2 was reduced by Al. The reducing medium was decided by calculating the thermodynamic formation energy. During the highenergy milling process, SiO2 was partially reduced and Al was simultaneously oxidized to aluminum oxide, yielding nano Si-embedded composite. The composite was characterized by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and high-resolution transmission microscopy. In electrochemical tests, the reversible capacity of the composite electrode was approximately 850 mAh g-1 with enhanced initial coulombic efficiency of 66%. This performance of the composite electrode was achieved not through carbon incorporation, but through the formation of Si-embedded nanocomposites.

  11. A Co(OH){sub 2}-graphene nanosheets composite as a high performance anode material for rechargeable lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    He, Y.S.; Yang, X.; Liao, X.Z.; Ma, Z.F. [Shanghai Jiao Tong Univ. (China). Dept. of Chemical Engineering; Chen, J. [Wollongong Univ., NSW (Australia). ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Inst.

    2010-07-01

    The 2-D structure of graphene provides it with excellent electronic conductivity, and a high surface area. Graphene nanosheets have been investigated for use in lithium-ion (Li-ion) storage applications. In this study nanostructured TiO{sub 2}-graphene hybrid materials were fabricated in order to investigate their potential uses in Li-ion batteries. The study showed that the materials showed significantly enhanced Li-ion insertion and extraction capabilities in TiO{sub 2}. A cobalt oxide (Co(OH){sub 2})-graphene nanosheet was also developed as an advanced anode material for Li-storage. The discharge-charge cycling performance of the material was discussed, as well as the coulombic efficiency of the synthesized samples. Results of the experimental study showed that after 30 cycles, the reversible capacity of the composite achieved approximately 82 per cent of its initial value. The corresponding capacity retentions of the graphene nanosheets and the Co(OH)2 after 30 cycles were approximately 66 per cent and 58 per cent, respectively. 5 refs.

  12. Method and Apparatus for Measuring Corrosion Beneath Thin Films

    Science.gov (United States)

    1991-02-19

    galvanic cell is created on a sensitive surface using alternating layers of anodic and cathodic materials such as steel and copper, which are electrically isolated by an insulation matrix. The surface is then cooled to below the dew point of the surrounding environment to cause condensation on the thin film. The galvanic current between the anodic and cathodic materials is then monitored for the first indication of environmental penetration through the film, i.e.,

  13. Thick-film materials for silicon photovoltaic cell manufacture

    Science.gov (United States)

    Field, M. B.

    1977-01-01

    Thick film technology is applicable to three areas of silicon solar cell fabrication; metallization, junction formation, and coating for protection of screened ohmic contacts, particularly wrap around contacts, interconnection and environmental protection. Both material and process parameters were investigated. Printed ohmic contacts on n- and p-type silicon are very sensitive to the processing parameters of firing time, temperature, and atmosphere. Wrap around contacts are easily achieved by first printing and firing a dielectric over the edge and subsequently applying a low firing temperature conductor. Interconnection of cells into arrays can be achieved by printing and cofiring thick film metal pastes, soldering, or with heat curing conductive epoxies on low cost substrates. Printed (thick) film vitreous protection coatings do not yet offer sufficient optical uniformity and transparency for use on silicon. A sprayed, heat curable SiO2 based resin shows promise of providing both optical matching and environmental protection.

  14. Growth of porous anodized alumina on the sputtered aluminum films with 2D–3D morphology for high specific surface area

    Energy Technology Data Exchange (ETDEWEB)

    Liao, M.W.; Chung, C.K., E-mail: ckchung@mail.ncku.edu.tw

    2014-08-01

    The porous anodic aluminum oxide (AAO) with high-aspect-ratio pore channels is widely used as a template for fabricating nanowires or other one-dimensional (1D) nanostructures. The high specific surface area of AAO can also be applied to the super capacitor and the supporting substrate for catalysis. The rough surface could be helpful to enhance specific surface area but it generally results in electrical field concentration even to ruin AAO. In this article, the aluminum (Al) films with the varied 2D–3D morphology on Si substrates were prepared using magnetron sputtering at a power of 50 W–185 W for 1 h at a working pressure of 2.5 × 10⁻¹ Pa. Then, AAO was fabricated from the different Al films by means of one-step hybrid pulse anodizing (HPA) between the positive 40 V and the negative -2 V (1 s:1 s) for 3 min in 0.3 M oxalic acid at a room temperature. The microstructure and morphology of Al films were characterized by X-ray diffraction, scanning electron microscope and atomic force microscope, respectively. Some hillocks formed at the high target power could be attributed to the grain texture growth in the normal orientation of Al(1 1 1). The 3D porous AAO structure which is different from the conventional 2D planar one has been successfully demonstrated using HPA on the film with greatly rough hillock-surface formed at the highest power of 185 W. It offers a potential application of the new 3D AAO to high specific surface area devices.

  15. Growth of porous anodized alumina on the sputtered aluminum films with 2D-3D morphology for high specific surface area

    Science.gov (United States)

    Liao, M. W.; Chung, C. K.

    2014-08-01

    The porous anodic aluminum oxide (AAO) with high-aspect-ratio pore channels is widely used as a template for fabricating nanowires or other one-dimensional (1D) nanostructures. The high specific surface area of AAO can also be applied to the super capacitor and the supporting substrate for catalysis. The rough surface could be helpful to enhance specific surface area but it generally results in electrical field concentration even to ruin AAO. In this article, the aluminum (Al) films with the varied 2D-3D morphology on Si substrates were prepared using magnetron sputtering at a power of 50 W-185 W for 1 h at a working pressure of 2.5 × 10-1 Pa. Then, AAO was fabricated from the different Al films by means of one-step hybrid pulse anodizing (HPA) between the positive 40 V and the negative -2 V (1 s:1 s) for 3 min in 0.3 M oxalic acid at a room temperature. The microstructure and morphology of Al films were characterized by X-ray diffraction, scanning electron microscope and atomic force microscope, respectively. Some hillocks formed at the high target power could be attributed to the grain texture growth in the normal orientation of Al(1 1 1). The 3D porous AAO structure which is different from the conventional 2D planar one has been successfully demonstrated using HPA on the film with greatly rough hillock-surface formed at the highest power of 185 W. It offers a potential application of the new 3D AAO to high specific surface area devices.

  16. Copper ferrites@reduced graphene oxide anode materials for advanced lithium storage applications.

    Science.gov (United States)

    Wang, Junyong; Deng, Qinglin; Li, Mengjiao; Jiang, Kai; Zhang, Jinzhong; Hu, Zhigao; Chu, Junhao

    2017-08-21

    Copper ferrites are emerging transition metal oxides that have potential applications in energy storage devices. However, it still lacks in-depth designing of copper ferrites based anode architectures with enhanced electroactivity for lithium-ion batteries. Here, we report a facile synthesis technology of copper ferrites anchored on reduced graphene oxide (CuFeO2@rGO and Cu/CuFe2O4@rGO) as the high-performance electrodes. In the resulting configuration, reduced graphene offers continuous conductive channels for electron/ion transfer and high specific surface area to accommodate the volume expansion of copper ferrites. Consequently, the sheet-on-sheet CuFeO2@rGO electrode exhibits a high reversible capacity (587 mAh g(-1) after 100 cycles at 200 mA g(-1)). In particular, Cu/CuFe2O4@rGO hybrid, which combines the advantages of nano-copper and reduced graphene, manifests a significant enhancement in lithium storage properties. It reveals superior rate capability (723 mAh g(-1) at 800 mA g(-1); 560 mAh g(-1) at 3200 mA g(-1)) and robust cycling capability (1102 mAh g(-1) after 250 cycles at 800 mA g(-1)). This unique structure design provides a strategy for the development of multivalent metal oxides in lithium storage device applications.

  17. Synthesis of binder-like molecules covalently linked to silicon nanoparticles and application as anode material for lithium-ion batteries without the use of electrolyte additives

    Science.gov (United States)

    Assresahegn, Birhanu Desalegn; Bélanger, Daniel

    2017-03-01

    A chemically modified silicon anode is prepared for application as anode in lithium-ion batteries by covalent attachment of polyacrylic acid to enable self-adhesion between the active material particles. The polyacrylic acid polymer is formed by atom transfer radical polymerization using 1-(bromoethyl)benzene initiator groups initially bonded to a hydrogenated silicon surface. The grafting of 1-(bromoethyl)benzene and polyacrylic acid is confirmed by various material characterization techniques. The electrochemical performance of the silicon anodes is also evaluated by galvanostatic cycling. The chemically modified composite silicon anode (with active material loading of 0.9-1 mg cm-2) showed a significantly improved performance in terms of: gravimetric capacitance (more than 2000 mAh g-1) after 300 cycles and 80% capacity retention with an average 99.6% Coulombic efficiency at a current density of 0.34 A g-1. However, the unmodified electrode cycled 75 times in the same conditions only retains 46% of its initial capacity with an average 95.1% Coulombic efficiency. The new composite Si electrode performs better at high charge/discharge rate and allows the use of larger proportion of the active material by reducing the amount of binder. It is noteworthy that these composite silicon electrodes are tested without the use of expensive electrolyte additives.

  18. Facile Synthesis of Mn-Doped ZnO Porous Nanosheets as Anode Materials for Lithium Ion Batteries with a Better Cycle Durability

    National Research Council Canada - National Science Library

    Wang, Linlin; Tang, Kaibin; Zhang, Min; Xu, Jingli

    2015-01-01

    Porous Zn1 − x Mn x O (x = 0.1, 0.2, 0.44) nanosheets were prepared by a low-cost, large-scale production and simple approach, and the applications of these nanosheets as an anode material for Li-ion batteries (LIBs) were explored...

  19. Anodes for alkaline electrolysis

    Science.gov (United States)

    Soloveichik, Grigorii Lev

    2011-02-01

    A method of making an anode for alkaline electrolysis cells includes adsorption of precursor material on a carbonaceous material, conversion of the precursor material to hydroxide form and conversion of precursor material from hydroxide form to oxy-hydroxide form within the alkaline electrolysis cell.

  20. Research progress of anode material for sodium-ion batteries%钠离子电池负极材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    杨绍斌; 董伟; 沈丁; 李思南; 王中将; 张佳民; 孙闻; 张琴

    2016-01-01

    The research status of anode materials in recent years, such as carbons, alloys, metal oxides and soon,were summarized, the performance and storage mechanism of sodiumofthe materials reachedwere introduced. The main problems of these kinds of anode materialsand the solutionwere discussed.The research directions and prospects on anode materialswereforecasted, and thecarbon materials with large layer spacing and less surface area is the most promising candidate anode material for sodium ion battery,and titanate with good structure stability is potential anode materials. Designing and developingnew materials is an important future research field for sodium ion battery.%综述近年来国内外对于碳、合金、金属氧化物等负极材料的研究现状,重点介绍材料的性能以及储钠机理,探讨材料存在的主要问题和解决方法,对负极材料的研究方向以及前景进行展望,指出具有较大层间距和较小比表面积的碳材料是目前最有希望应用于钠离子电池的负极材料,结构稳定性较好的钛酸盐材料是极具潜力的负极材料,设计开发适合的离子电池自身特点的新材料是未来钠电子电池研究的重要方向。