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Sample records for based electrolytic reduction

  1. based gel polymer electrolytes

    Indian Academy of Sciences (India)

    operating systems. With this situation, attempts have been made in poly (ethylene oxide) (PEO) based polymer electrolytes to reach an appreciable electrical conducti- vity at ambient temperature (Wright 1975; Martuscelli et al 1984). Generally solid polymer electrolytes have many advantages, viz. high ionic conductivity, ...

  2. F4U production by electrolytic reduction

    International Nuclear Information System (INIS)

    Esteban Duque, A.; Gispert Benach, M.; Hernandez Arroyo, F.; Montes Ponce de Leon, M.; Rojas de Diego, J. L.

    1974-01-01

    As a part of the nuclear fuel cycle program developed at the Spanish Atomic Energy Commission it has been studied the electrolytic reduction of U-VI to U-IV. The effect of the materials, electrolyte concentration, pH, current density, cell size and laboratory scale production is studied. The Pilot Plant and the production data are also described. (Author) 18 refs

  3. based gel polymer electrolytes

    Indian Academy of Sciences (India)

    Bull. Mater. Sci., Vol. 29, No. 7, December 2006, pp. 673–678. © Indian Academy of Sciences. 673. Investigation on poly (vinylidene fluoride) based gel polymer electrolytes ... (Alamgir and Abraham 1993; Sukeshini et al 1996; Ra- jendran and Uma ... Yang et al 1996; Ramesh and Arof 2001) and such elec- trolytes exhibit ...

  4. Safeguard monitoring of direct electrolytic reduction

    Science.gov (United States)

    Jurovitzki, Abraham L.

    Nuclear power is regaining global prominence as a sustainable energy source as the world faces the consequences of depending on limited fossil based, CO2 emitting fuels. A key component to achieving this sustainability is to implement a closed nuclear fuel cycle. Without achieving this goal, a relatively small fraction of the energy value in nuclear fuel is actually utilized. This involves recycling of spent nuclear fuel (SNF)---separating fissile actinides from waste products and using them to fabricate fresh fuel. Pyroprocessing is a viable option being developed for this purpose with a host of benefits compared to other recycling options, such as PUREX. Notably, pyroprocessing is ill suited to separate pure plutonium from spent fuel and thus has non-proliferation benefits. Pyroprocessing involves high temperature electrochemical and chemical processing of SNF in a molten salt electrolyte. During this batch process, several intermediate and final streams are produced that contain radioactive material. While pyroprocessing is ineffective at separating pure plutonium, there are various process misuse scenarios that could result in diversion of impure plutonium into one or more of these streams. This is a proliferation risk that should be addressed with innovative safeguards technology. One approach to meeting this challenge is to develop real time monitoring techniques that can be implemented in the hot cells and coupled with the various unit operations involved with pyroprocessing. Current state of the art monitoring techniques involve external chemical assaying which requires sample removal from these unit operations. These methods do not meet International Atomic Energy Agency's (IAEA) timeliness requirements. In this work, a number of monitoring techniques were assessed for their viability as online monitoring tools. A hypothetical diversion scenario for the direct electrolytic reduction process was experimentally verified (using Nd2O3 as a surrogate for PuO2

  5. Shedding Light on the Oxygen Reduction Reaction Mechanism in Ether-Based Electrolyte Solutions: A Study Using Operando UV-Vis Spectroscopy.

    Science.gov (United States)

    Hirshberg, Daniel; Sharon, Daniel; Afri, Michal; Lavi, Ronit; Frimer, Aryeh A; Metoki, Noa; Eliaz, Noam; Kwak, Won-Jin; Sun, Yang-Kook; Aurbach, Doron

    2018-03-20

    Using UV-vis spectroscopy in conjunction with various electrochemical techniques, we have developed a new effective operando methodology for investigating the oxygen reduction reactions (ORRs) and their mechanisms in nonaqueous solutions. We can follow the in situ formation and presence of superoxide moieties during ORR as a function of solvent, cations, anions, and additives in the solution. Thus, using operando UV-vis spectroscopy, we found evidence for the formation of superoxide radical anions during oxygen reduction in LiTFSI/diglyme electrolyte solutions. Nitro blue tetrazolium (NBT) was used to indicate the presence of superoxide moieties based on its unique spectral response. Indeed, the spectral response of NBT containing solutions undergoing ORR could provide a direct indication for the level of association of the Li cations with the electrolyte anions.

  6. Additive effect on reductive decomposition and binding of carbonate-based solvent toward solid electrolyte interphase formation in lithium-ion battery.

    Science.gov (United States)

    Ushirogata, Keisuke; Sodeyama, Keitaro; Okuno, Yukihiro; Tateyama, Yoshitaka

    2013-08-14

    The solid-electrolyte interphase (SEI) formed through the reductive decomposition of solvent molecules plays a crucial role in the stability and capability of a lithium-ion battery (LIB). Here we investigated the effects of adding vinylene carbonate (VC) to ethylene carbonate (EC) solvent, a typical electrolyte in LIBs, on the reductive decomposition. We focused on both thermodynamics and kinetics of the possible processes and used density functional theory-based molecular dynamics with explicit solvent and Blue-moon ensemble technique for the free energy change. We considered Li(+) in only EC solvent (EC system) and in EC solvent with a VC additive (EC/VC system) to elucidate the additive effects. In addition to clarifying the equilibrium properties, we evaluated the free energy changes along several EC or VC decomposition pathways under one-electron (1e) reduction condition. Two-electron (2e) reduction and attacks of anion radicals to intact molecules were also examined. The present results completely reproduce the gaseous products observed in the experiments. We also found a new mechanism involving the VC additive: the VC additive preferentially reacts with the EC anion radical to suppress the 2e reduction of EC and enhance the initial SEI formation, contrary to the conventional scenario in which VC additive is sacrificially reduced and its radical oligomerization becomes the source of SEI. Because our mechanism needs only 1e reduction, the irreversible capacity at the SEI formation will decrease, which is also consistent with the experimental observations. These results reveal the primary role of VC additive in the EC solvent.

  7. Alternative Anodes for the Electrolytic Reduction of Uranium Dioxide

    Science.gov (United States)

    Merwin, Augustus

    Reprocessing of spent nuclear fuel is an essential step in closing the nuclear fuel cycle. In order to consume current stockpiles, ceramic uranium dioxide spent nuclear fuel will be subjected to an electrolytic reduction process. The current reduction process employs a platinum anode and a stainless steel alloy 316 cathode in a molten salt bath consisting of LiCl-2wt% Li 2O and occurs at 700°C. A major shortcoming of the existing process is the degradation of the platinum anode under the severely oxidizing conditions encountered during electrolytic reduction. This work investigates alternative anode materials for the electrolytic reduction of uranium oxide. The high temperature and extreme oxidizing conditions encountered in these studies necessitated a unique set of design constraints on the system. Thus, a customized experimental apparatus was designed and constructed. The electrochemical experiments were performed in an electrochemical reactor placed inside a furnace. This entire setup was housed inside a glove box, in order to maintain an inert atmosphere. This study investigates alternative anode materials through accelerated corrosion testing. Surface morphology was studied using scanning electron microscopy. Surface chemistry was characterized using energy dispersive spectroscopy and Raman spectroscopy. Electrochemical behavior of candidate materials was evaluated using potentiodynamic polarization characteristics. After narrowing the number of candidate electrode materials, ferrous stainless steel alloy 316, nickel based Inconel 718 and elemental tungsten were chosen for further investigation. Of these materials only tungsten was found to be sufficiently stable at the anodic potential required for electrolysis of uranium dioxide in molten salt. The tungsten anode and stainless steel alloy 316 cathode electrode system was studied at the required reduction potential for UO2 with varying lithium oxide concentrations. Electrochemical impedance spectroscopy

  8. Laser-induced metal reduction from liquid electrolyte precursor.

    Science.gov (United States)

    Kim, Dongsoo; Choi, Choljin

    2013-11-01

    A special sort of laser methods such as direct writing of metal and thin film deposition from liquid precursors was developed for the surface processing and the localized metallization of different kinds of materials. Laser radiation initiates the chemical reaction resulted in the reduction of the metal complexes to the metals in the liquid electrolyte, followed by the metal deposition on the substrate with a high degree of the adhesion. In this study, continuous wave of Ar+ laser generated in multiwave regime with laser power from 5 to 500 mW was chosen for the Copper reduction and deposition on SiO2 substrate. In order to investigate the effect of salt precursors on the properties of the deposited structures, two kinds of electrolyte solution were prepared on the base of CuSO4 and CuCl2. It was shown that metal deposition can be initiated at the laser power of 50 mW. The width of the deposits was found to be substantially dependent on the applied laser power. Deposits were revealed as conductive layers and the resistance of the layers depends strongly on the solution temperature and the salt precursor.

  9. Oxygen reduction on carbon supported platinum catalysts in high temperature polymer electrolytes

    DEFF Research Database (Denmark)

    Qingfeng, Li; Hjuler, Hans Aage; Bjerrum, Niels

    2000-01-01

    Oxygen reduction on carbon supported platinum catalysts has been investigated in H3PO4, H3PO4-doped Nafion and polybenzimidazole (PBI) polymer electrolytes in a temperature range up to 190 degrees C. Compared with pure H3PO4, the combination of H3PO4 and polymer electrolytes can significantly...... membrane fuel cell based on H3PO4-doped PBI for operation at temperatures between 150 and 200 degrees C. (C) 2000 Elsevier Science Ltd. All rights reserved....

  10. The Pt(111)/Electrolyte Interface under Oxygen Reduction Reaction Conditions

    DEFF Research Database (Denmark)

    Bondarenko, A.S.; Stephens, Ifan; Hansen, Heine Anton

    2011-01-01

    The Pt(111)/electrolyte interface has been characterized during the oxygen reduction reaction (ORR) in 0.1 M HClO4 using electrochemical impedance spectroscopy. The surface was studied within the potential region where adsorption of OH* and O* species occur without significant place exchange...... between the adsorbate and Pt surface atoms (0.45−1.15 V vs RHE). An equivalent electric circuit is proposed to model the Pt(111)/electrolyte interface under ORR conditions within the selected potential window. This equivalent circuit reflects three processes with different time constants, which occur...

  11. Handheld Microneedle-Based Electrolyte Sensing Platform.

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Philip R. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Rivas, Rhiana [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Johnson, David [Aquila Technologies Group, Inc., Albuquerque, NM (United States); Edwards, Thayne L. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Koskelo, Markku [Aquila Technologies Group, Inc., Albuquerque, NM (United States); Shawa, Luay [Aquila Technologies Group, Inc., Albuquerque, NM (United States); Brener, Igal [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Chavez, Victor H. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Polsky, Ronen [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    Sandia National Laboratories will provide technical assistance, within time and budget, to Requester on testing and analyzing a microneedle-based electrolyte sensing platform. Hollow microneedles will be fabricated at Sandia and integrated with a fluidic chip using plastic laminate prototyping technology available at Sandia. In connection with commercial ion selective electrodes the sensing platform will be tested for detection of electrolytes (sodium and/or potassium) within physiological relevant concent ration ranges.

  12. Reduction mechanism of fluoroethylene carbonate for stable solid–electrolyte interphase film on silicon anode.

    Science.gov (United States)

    Chen, Xilin; Li, Xiaolin; Mei, Donghai; Feng, Ju; Hu, Mary Y; Hu, Jianzhi; Engelhard, Mark; Zheng, Jianming; Xu, Wu; Xiao, Jie; Liu, Jun; Zhang, Ji-Guang

    2014-02-01

    Fluoroethylene carbonate (FEC) is an effective electrolyte additive that can significantly improve the cycling ability of silicon and other anode materials. However, the fundamental mechanism of this improvement is still not well understood. Based on the results obtained from (6)Li NMR and X-ray photoelectron spectroscopy studies, we propose a molecular-level mechanism for how FEC affects the formation of solid electrolyte interphase (SEI) film: 1) FEC is reduced through the opening of the five-membered ring leading to the formation of lithium poly(vinyl carbonate), LiF, and some dimers; 2) the FEC-derived lithium poly(vinyl carbonate) enhances the stability of the SEI film. The proposed reduction mechanism opens a new path to explore new electrolyte additives that can improve the cycling stability of silicon-based electrodes.

  13. Chemical stability of {gamma}-butyrolactone-based electrolytes for aluminium electrolytic capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Ue, Makoto [Mitsubishi Chemical Corp., Tsukuba Research Center, Ibaraki (Japan); Takeda, Masayuki [Mitsubishi Chemical Corp., Tsukuba Research Center, Ibaraki (Japan); Suzuki, Yoko [Mitsubishi Chemical Corp., Tsukuba Research Center, Ibaraki (Japan); Mori, Shoichiro [Mitsubishi Chemical Corp., Tsukuba Research Center, Ibaraki (Japan)

    1996-06-01

    {gamma}-Butyrolactone-based electrolytes have been used as the operating electrolytes for aluminum electrolytic capacitors. The chemical stability of these electrolytes at elevated temperatures has been examined by monitoring the decrease in their electrolytic conductivities. The deteriorated electrolytes were analyzed by gas and liquid chromatography and the conductivity decrease was directly correlated with the loss of acid components. In quaternary ammonium hydrogen maleate/{gamma}-butyrolactone electrolytes, the maleate anion decomposed by decarboxylation resulting in a complex polymer containing polyester and polyacrylate structures. Quaternary ammonium benzoate/{gamma}-butyrolactone electrolytes decomposed by SN2 reactions giving alkyl benzoates and trialkylamines. The deterioration of the carboxylate salt/{gamma}-butyrolactone electrolytes was accelerated by electrolysis. (orig.)

  14. A Study on the Electrolytic Reduction Mechanism of Uranium Oxide in a LiCl-Li2O Molten Salt

    International Nuclear Information System (INIS)

    Oh, Seung Chul; Hur, Jin Mok; Seo, Chung Seok; Park, Seong Won

    2003-01-01

    This study proposed a new electrolytic reduction technology that is based on the integration of simultaneous uranium oxide metallization and Li 2 O electrowinning. In this electrolytic reduction reaction, electrolytically reduced Li deposits on cathode and simultaneously reacts with uranium oxides to produce uranium metal showing more than 99% conversion. For the verification of process feasibility, the experiments to obtain basic data on the metallization of uranium oxide, investigation of reaction mechanism, the characteristics of closed recycle of Li 2 O and mass transfer were carried out. This evolutionary electrolytic reduction technology would give benefits over the conventional Li-reduction process improving economic viability such as: avoidance of handling of chemically active Li-LiCl molten salt increase of metallization yield, and simplification of process.

  15. A study on the electrolytic reduction of uranium oxide in a LiCl-Li2O molten salt

    International Nuclear Information System (INIS)

    Su, J. S.; Hu, J. M.; Hong, S. S.; Jang, D. S.; Park, S. W.

    2003-01-01

    New electrolytic reduction technology was proposed that is based on the integration of metallization of uranium oxide and Li 2 O electrowinning. In this electrolytic reduction reaction, electrolytically reduced Li deposits on cathode and simultaneously reacts with uranium oxides to produce uranium metal showing more than 99% conversion. For the verification of process feasibility, the experiments to obtain basic data on the metallization of uranium oxide, investigation of reaction mechanism, the characteristics of closed recycle of Li 2 O and mass transfer were carried out. This evolutionary electrolytic reduction technology would give benefits over the conventional Li-reduction process improving economic viability such as: avoidance of handling of chemically active Li-LiCl molten salt, increase of metallization yield, and simplification of process

  16. Effects of carbon pretreatment for oxygen reduction in alkaline electrolyte

    Science.gov (United States)

    Pirjamali, Massoud; Kiros, Yohannes

    The effects of different media on carbon pretreatments for oxygen reduction in alkaline electrolyte without application of active electrocatalysts were examined. Low surface area Vulcan XC-72 and high surface area Ketjenblack EC-300 were subjected to aqueous acid (flouric or formic), gaseous (H 2, N 2 or CO 2) and thermal treatments at 600 or 900 °C. Though non-scrubbed air was used, as a result of which carbonate build-up was high and peroxide concentration increased due to the electrode reaction, some of the electrodes resulted in life-tests of more than 2000 h at 65 °C, 6 M KOH with a constant load of 50 mA cm -2 and intermittent polarisations at higher current densities. BET-surface areas and pH changes of more than 60% and weight losses of up to 15% of the carbon blacks were observed after the pretreatment steps. Electrochemical characterisation of the carbons showed that pretreatment steps of the carbon blacks have a significant effect on the long-term stability and activity of the gas diffusion electrodes in alkaline electrolyte.

  17. New polysaccharide-based polymer electrolytes; Nouveaux electrolytes polymeres a base de polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Velasquez-Morales, P.; Le Nest, J.F.; Gandini, A. [Ecole Francaise de Papeterie et des Industries Graphique, 38 - Saint Martin d`Heres (France)

    1996-12-31

    Polysaccharides like cellulose and chitosan are known for their filmic properties. This paper concerns the synthesis and the study of chitosan-based polymer electrolytes. A preliminary work concerns the study of glucosamine reactivity. The poly-condensation of chitosan ethers (obtained by reaction with ethylene oxide or propylene oxide) with bifunctional and monofunctional oligo-ethers leads to the formation of thin lattices (10 {mu}m) having excellent mechanical properties. The presence of grafted polyether chains along the polysaccharide skeleton allows to modify the vitreous transition temperature and the molecular disorder of the system. Two type of polymer electrolytes have been synthesized: electrolytes carrying a dissolved alkaline metal salt and ionomers. The analysis of their thermal, dynamical mechanical, nuclear magnetic relaxation, electrical, and electrochemical properties shows that this new class of polymer electrolytes has the same performances as ethylene poly-oxide based amorphous lattices plus the advantage of having good filmic properties. Abstract only. (J.S.)

  18. Study on electrolytic reduction with controlled oxygen flow for iron from molten oxide slag containing FeO

    Directory of Open Access Journals (Sweden)

    Gao Y.M.

    2013-01-01

    Full Text Available A ZrO2-based solid membrane electrolytic cell with controlled oxygen flow was constructed: graphite rod /[O]Fe+C saturated / ZrO2(MgO/(FeO slag/iron crucible. The feasibility of extraction of iron from molten oxide slag containing FeO at an applied voltage was investigated by means of the electrolytic cell. The effects of some important process factors on the FeO electrolytic reduction with the controlled oxygen flow were discussed. The results show that: solid iron can be extracted from molten oxide slag containing FeO at 1450ºC and an applied potential of 4V. These factors, such as precipitation and growth of solid iron dendrites, change of the cathode active area on the inner wall of the iron crucible and ion diffusion flux in the molten slag may affect the electrochemical reaction rate. The reduction for Fe2+ ions mainly appears on new iron dendrites of the iron crucible cathode, and a very small amount of iron are also formed on the MSZ (2.18% MgO partially stabilized zirconia tube/slag interface due to electronic conductance of MSZ tube. Internal electronic current through MSZ tube may change direction at earlier and later electrolytic reduction stage. It has a role of promoting electrolytic reduction for FeO in the molten slag at the earlier stage, but will lower the current efficiency at the later stage. The final reduction ratio of FeO in the molten slag can achieve 99%. A novel electrolytic method with controlled oxygen flow for iron from the molten oxide slag containing FeO was proposed. The theory of electrolytic reduction with the controlled oxygen flow was developed.

  19. Searching for electrolytes and electrodes for CO2 reduction below 300 °C

    DEFF Research Database (Denmark)

    Vico, Federica

    and temperatures. A foam based CO2 conversion cell with gas diffusion electrodes and a ceramic porous structure in which the liquid electrolyte is immobilized by capillary forces was developed and tested up to 20 bar and to a maximum temperature of 50 °C. Potassium carbonate was selected as aqueous electrolyte...... practical application for carbon dioxide reduction at high pressure. K-doped BaZr1-xYxO3-δ was successfully synthesized by hydrothermal technique, but the conductivity recorded in high pH2O and at 240 °C was too low (3 · 10-5 S/cm) to be considered as a suitable electrolyte. A literature survey showed...... conducted at Stanford University – Chemical Engineer Department, where it was possible to utilize an experimental setup which ensures high sensitivity for minor products from the CO2 reduction reaction. Seven products were identified with the copper foam electrode tested to -0.98 V vs. RHE. H2, formate...

  20. Oxygen reduction on carbon supported platinum catalysts in high temperature polymer electrolytes

    DEFF Research Database (Denmark)

    Qingfeng, Li; Bergqvist, R. S.; Hjuler, H. A.

    1999-01-01

    Oxygen reduction on carbon supported platinum catalysts has been investigated in H3PO4, H3PO4-doped Nafion and PBI polymer electrolytes in a temperature range from 80 to 190°C. Compared with pure H3PO4, using the H3PO4 doped Nafion and PBI polymer electrolytes can significantly improve the oxygen...

  1. The Electrolyte Factor in O2 Reduction Electrocatalysis

    Science.gov (United States)

    1993-04-23

    to blend the duPont Nation or Dow 560 polymer into the active catalyst layer with the solid ionomer replacing the fluid electrolyte which in a properly...without the SPE. In place of solid ionomers such as Nafion, hydrogels can be used as the electrolyte within the active catalyst agglomerates. The authors...film on Au are those expected with the hydrophobic fluorocarbon phase of the ionomer adjacent to the metal-polymer interface . On Pt and probably also

  2. Development of an Activated Carbon-Based Electrode for the Capture and Rapid Electrolytic Reductive Debromination of Methyl Bromide from Postharvest Fumigations.

    Science.gov (United States)

    Li, Yuanqing; Liu, Chong; Cui, Yi; Walse, Spencer S; Olver, Ryan; Zilberman, David; Mitch, William A

    2016-10-18

    Due to concerns surrounding its ozone depletion potential, there is a need for technologies to capture and destroy methyl bromide (CH 3 Br) emissions from postharvest fumigations applied to control agricultural pests. Previously, we described a system in which CH 3 Br fumes vented from fumigation chambers could be captured by granular activated carbon (GAC). The GAC was converted to a cathode by submergence in a high ionic strength solution and connection to the electrical grid, resulting in reductive debromination of the sorbed CH 3 Br. The GAC bed was drained and dried for reuse to capture and destroy CH 3 Br fumes from the next fumigation. However, the loose GAC particles and slow kinetics of this primitive electrode necessitated improvements. Here, we report the development of a cathode containing a thin layer of small GAC particles coating carbon cloth as a current distributor. Combining the high sorption potential of GAC for CH 3 Br with the conductivity of the carbon cloth current distributor, the cathode significantly lowered the total cell resistance and achieved 96% reductive debromination of CH 3 Br sorbed at 30% by weight to the GAC within 15 h at -1 V applied potential vs standard hydrogen electrode, a time scale and efficiency suitable for postharvest fumigations. The cathode exhibited stable performance over 50 CH 3 Br capture and destruction cycles. Initial cost estimates indicate that this technique could treat CH 3 Br fumes at ∼$5/kg, roughly one-third of the cost of current alternatives.

  3. Performance of Lithium Polymer Cells with Polyacrylonitrile based Electrolyte

    DEFF Research Database (Denmark)

    Perera, Kumudu; Dissanayake, M.A.K.L.; Skaarup, Steen

    2006-01-01

    The performance of lithium polymer cells fabricated with Polyacrylonitrile (PAN) based electrolytes was studied using cycling voltammetry and continuous charge discharge cycling. The electrolytes consisted of PAN, ethylene carbonate (EC), propylene carbonate (PC) and lithium trifluoromethanesulfo......The performance of lithium polymer cells fabricated with Polyacrylonitrile (PAN) based electrolytes was studied using cycling voltammetry and continuous charge discharge cycling. The electrolytes consisted of PAN, ethylene carbonate (EC), propylene carbonate (PC) and lithium...... voltammetry at slow scan rates were similar. The charge factor remained close to unity. These results show the fact that satisfactory cell performance can be achieved with thin electrode films and cycling at slow scan rates....

  4. Polyvinyl butyral based solid polymeric electrolytes. Preliminary studies

    Energy Technology Data Exchange (ETDEWEB)

    Gopal, Shaleen; Ramchandran, R.; Agnihotry, Rashmi S.A. [National Physical Laboratory, New Delhi (India)

    1996-01-08

    A series of solid polymeric electrolytes has been prepared based on Polyvinyl Butyral (PVB) with different proportions of LiI salt. These polymeric electrolytes showed high ionic conductivity, which has been investigated as a function of the LiI concentration. The highest conductivity was seen at weight proportions 1:0.15 for PVB:LiI. An electrochromic device fabricated using this polymeric electrolyte showed good switching

  5. An electro-kinetic study of oxygen reduction in polymer electrolyte fuel cells at intermediate temperatures

    OpenAIRE

    Gatto, I.; Stassi, A.; Passalacqua, E.; Arico, A. S.

    2013-01-01

    International audience; The oxygen reduction process in polymer electrolyte fuel cells (PEMFCs) was in-situ investigated at intermediate temperatures (80 e130 C) by using a carbon supported PtCo catalyst and Nafion membrane as electrolyte. To overcome the Nafion dehydration above 100 C, the experiments were carried out under pressurized conditions. Electro-kinetic parameters such as reaction order and activation energy were determined from the steady-state galvanostatic polarization curves ob...

  6. A study on the electrolytic reduction of U3O8 to uranium metal in LiCl-Li2O molten salt

    International Nuclear Information System (INIS)

    Seo, J. S.; Heo, J. M.; Hong, S. S.; Kang, D. S.; Park, S. W.

    2002-01-01

    New electrolytic reduction technology was proposed that is based on the intregration of metallization of U 3 O 8 and Li 2 O electrowinning. In this electrolytic reduction reaction, electrolytically reduced Li deposits on cathode and simultaneously reacts with uranium oxide to produce uranium metal showing more than 99% conversion. For the verification of process feasibility, the experiments to obtain basic data on the metallization of uranium oxide, materials for cathode and anode electrode, the characteristics of closed recycle of Li 2 O and mass transfer were carried out. This evolutionary electrolytic reduction technology would give benefits over the conventional Li-reduction process improving economic viability such as: avoidance of handling of chemically active Li-LiCl molten salt, increase of metallization yield, and simplification of process

  7. Lithium ion conducting solid polymer blend electrolyte based on bio ...

    Indian Academy of Sciences (India)

    Lithium ion conducting polymer blend electrolyte films based on poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) with different Mwt% of lithium nitrate (LiNO3) salt, using a solution cast technique, have been prepared. The polymer blend electrolyte has been characterized by XRD, FTIR, DSC and impedance ...

  8. A Study of Electrochemical Reduction of Ethylene and PropyleneCarbonate Electrolytes on Graphite Using ATR-FTIR Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Guorong V.; Yang, Hui; Blizanac, Berislav; Ross Jr.,Philip N.

    2005-05-12

    We present results testing the hypothesis that there is a different reaction pathway for the electrochemical reduction of PC versus EC-based electrolytes at graphite electrodes with LiPF6 as the salt in common. We examined the reduction products formed using ex-situ Fourier Transform Infrared (FTIR) spectroscopy in attenuated total reflection (ATR) geometry. The results show the pathway for reduction of PC leads nearly entirely to lithium carbonate as the solid product (and presumably ethylene gas as the co-product) while EC follows a path producing a mixture of organic and inorganic compounds. Possible explanations for the difference in reaction pathway are discussed.

  9. Ionic Liquid based polymer electrolytes for electrochemical sensors

    Directory of Open Access Journals (Sweden)

    Jakub Altšmíd

    2015-09-01

    Full Text Available Amperometric NO2 printed sensor with a new type of solid polymer electrolyte and a carbon working electrode has been developed. The electrolytes based on 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonylimide [EMIM][N(Tf2], 1-butyl-3-methylimidazolium trifluoromethanesulfonate [BMIM][CF3SO3] and 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4] ionic liquids were immobilized in poly(vinylidene fluoride matrix [PVDF]. The analyte, gaseous nitrogen dioxide, was detected by reduction at -500 mV vs. platinum pseudoreference electrode. The sensors showed a linear behavior in the whole tested range, i.e., 0 - 5 ppm and their sensitivities were in order of 0.3 x∙10-6 A/ppm. The sensor sensitivity was influenced by the electric conductivity of printing formulation; the higher the conductivity, the higher the sensor sensitivity. The rise/recovery times were in order of tens of seconds. The use of  screen printing technology and platinum pseudoreference electrode simplify the sensor fabrication and it does not have any negative effect on the sensor stability.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7371

  10. PMMA-based aprotic gel electrolytes

    Czech Academy of Sciences Publication Activity Database

    Vondrák, Jiří; Reiter, Jakub; Velická, Jana; Sedlaříková, M.

    2004-01-01

    Roč. 170, 1-2 (2004), s. 79-82 ISSN 0167-2738 R&D Projects: GA ČR GA104/02/0731; GA AV ČR IAA4032002 Institutional research plan: CEZ:AV0Z4032918 Keywords : polymer electrolytes * methylmethacrylate * cadmium salts Subject RIV: CA - Inorganic Chemistry Impact factor: 1.862, year: 2004

  11. Physics based Degradation Modeling and Prognostics of Electrolytic Capacitors under Electrical Overstress Conditions

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper proposes a physics based degradation modeling and prognostics approach for electrolytic capacitors. Electrolytic capacitors are critical components in...

  12. Prognostics Health Management and Physics based failure Models for Electrolytic Capacitors

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper proposes first principles based modeling and prognostics approach for electrolytic capacitors. Electrolytic capacitors and MOSFETs are the two major...

  13. Impedance Spectroscopy and FTIR Studies of PEG - Based Polymer Electrolytes

    Directory of Open Access Journals (Sweden)

    Anji Reddy Polu

    2011-01-01

    Full Text Available Ionic conductivity of poly(ethylene glycol (PEG - ammonium chloride (NH4Cl based polymer electrolytes can be enhanced by incorporating ceramic filler TiO2 into PEG-NH4Cl matrix. The electrolyte samples were prepared by solution casting technique. FTIR studies indicates that the complex formation between the polymer, salt and ceramic filler. The ionic conductivity was measured using impedance spectroscopy technique. It was observed that the conductivity of the electrolyte varies with TiO2 concentration and temperature. The highest room temperature conductivity of the electrolyte of 7.72×10−6 S cm-1 was obtained at 15% by weight of TiO2 and that without TiO2 filler was found to be 9.58×10−7 S cm−1. The conductivity has been improved by 8 times when the TiO2 filler was introduced into the PEG–NH4Cl electrolyte system. The conductance spectra shows two distinct regions: a dc plateau and a dispersive region. The temperature dependence of the conductivity of the polymer electrolytes seems to obey the VTF relation. The conductivity values of the polymer electrolytes were reported and the results were discussed. The imaginary part of dielectric constant (εi decreases with increase in frequency in the low frequency region whereas frequency independent behavior is observed in the high frequency region.

  14. On the suppression of cathodic hypochlorite reduction by electrolyte additions of molybdate and chromate ions

    Directory of Open Access Journals (Sweden)

    JOHN GUSTAVSSON

    2012-11-01

    Full Text Available The goal of this study was to gain a better understanding of the feasibility of replacing Cr(VI in the chlorate process by Mo(VI, focusing on the cathode reaction selectivity for hydrogen evolution on steel and titanium in a hypochlorite containing electrolyte. To evaluate the ability of Cr(VI and Mo(VI additions to hinder hypochlorite reduction, potential sweep experiments on rotating disc electrodes and cathodic current efficiency (CE measurements on stationary electrodes were performed. Formed electrode films were investigated with scanning electron microscopy and energy-dispersive X-ray spectroscopy. Cathodic hypochlorite reduction is hindered by the Mo-containing films formed on the cathode surface after Mo(VI addition to the electrolyte, but much less efficient compared to Cr(VI addition. Very low levels of Cr(VI, in the mM range, can efficiently suppress hypochlorite reduction on polished titanium and steel. Phosphate does not negatively influence the CE in the presence of Cr(VI or Mo(VI but the Mo-containing cathode films become thinner if the electrolyte during the film build-up also contains phosphate. For a RuO2-TiO2 anode polarized in electrolyte with 40 mM Mo(VI, the anode potential increased and increased molybdenum levels were detected on the electrode surface

  15. Development of corrosion resistant materials for an electrolytic reduction process of a spent nuclear fuel

    International Nuclear Information System (INIS)

    Jong-Hyeon Lee; Soo-Haeng Cho; Jeong-Gook Oh; Eung-Ho Kim

    2008-01-01

    New alloys were designed and prepared to improve their corrosion resistance in an electrolytic reduction environment for a spent oxide fuel on the basis of a thermodynamical assessment. A considerable solubility of Si was confirmed in the Ni alloys and their corrosion resistance was drastically increased with the addition of Si. It was confirmed that a protective oxide layer was formed during a corrosion test due to a reaction among the alloying elements such as Cr, Al and Si. (authors)

  16. F{sub 4}U production by electrolytic reduction; Obtencion de UF{sub 4} por reduccion electrolitica

    Energy Technology Data Exchange (ETDEWEB)

    Esteban Duque, A.; Gispert Benach, M.; Hernandez Arroyo, F.; Montes Ponce de Leon, M.; Rojas de Diego, J. L.

    1974-07-01

    As a part of the nuclear fuel cycle program developed at the Spanish Atomic Energy Commission it has been studied the electrolytic reduction of U-VI to U-IV. The effect of the materials, electrolyte concentration, pH, current density, cell size and laboratory scale production is studied. The Pilot Plant and the production data are also described. (Author) 18 refs.

  17. Determination of uranium and plutonium in metal conversion products from electrolytic reduction process

    International Nuclear Information System (INIS)

    Lee, Chang Heon; Suh, Moo Yul; Joe, Kih Soo; Sohn, Se Chul; Jee, Kwang Young; Kim, Won Ho

    2005-01-01

    Chemical characterization of process materials is required for the optimization of an electrolytic reduction process in which uranium dioxide, a matrix of spent PWR fuels, is electrolytically reduced to uranium metal in a medium of LiCl-Li 2 O molten at 650 .deg. C. A study on the determination of fissile materials in the uranium metal products containing corrosion products, fission products and residual process materials has been performed by controlled-potential coulometric titration which is well known in the field of nuclear science and technology. Interference of Fe, Ni, Cr and Mg (corrosion products), Nd (fission product) and LiCl molten salt (residual process material) on the determination of uranium and plutonium, and the necessity of plutonium separation prior to the titration are discussed in detail. Under the analytical condition established already, their recovery yields are evaluated along with analytical reliability

  18. Novel Non-Carbonate Based Electrolytes for Silicon Anodes

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Ye [Wildcat Discovery Technologies, San Diego, CA (United States); Yang, Johnny [Wildcat Discovery Technologies, San Diego, CA (United States); Cheng, Gang [Wildcat Discovery Technologies, San Diego, CA (United States); Carroll, Kyler [Wildcat Discovery Technologies, San Diego, CA (United States); Clemons, Owen [Wildcat Discovery Technologies, San Diego, CA (United States); Strand, Diedre [Wildcat Discovery Technologies, San Diego, CA (United States)

    2016-09-09

    Substantial improvement in the energy density of rechargeable lithium batteries is required to meet the future needs for electric and plug-in electric vehicles (EV and PHEV). Present day lithium ion battery technology is based on shuttling lithium between graphitic carbon and inorganic oxides. Non-graphitic anodes, such as silicon can provide significant improvements in energy density but are currently limited in cycle life due to reactivity with the electrolyte. Wildcat/3M proposes the development of non-carbonate electrolyte formulations tailored for silicon alloy anodes. Combining these electrolytes with 3M’s anode and an NMC cathode will enable up to a 20% increase in the volumetric cell energy density, while still meeting the PHEV/EV cell level cycle/calendar life goals.

  19. Understanding ternary poly(potassium benzimidazolide)-based polymer electrolytes

    DEFF Research Database (Denmark)

    Aili, David; Jankova Atanasova, Katja; Han, Junyoung

    2016-01-01

    Poly(2,20-(m-phenylene)-5,50-bisbenzimidazole) (m-PBI) can dissolve large amounts of aqueous electrolytes to give materials with extraordinary high ion conductivity and the practical applicability has been demonstrated repeatedly in fuel cells, water electrolysers and as anion conducting component...... swelling, high electrolyte uptake, dramatic plasticization and increase of the ion conductivity for the formed poly(potassium benzimidazolide)-based structure. Further increasing the concentration of the bulk solution to 50 wt.% resulted in dehydration and extensive crystallization of the polymer matrix...

  20. based anion exchange membrane for alkaline polymer electrolyte

    Indian Academy of Sciences (India)

    Administrator

    Abstract. Hydroxyl ion (OH–) conducting anion exchange membranes based on modified poly (phenylene oxide) are fabricated for their application in alkaline polymer electrolyte fuel cells (APEFCs). In the present study, chloromethylation of poly(phenylene oxide) (PPO) is performed by aryl substitution rather than benzyl.

  1. Supercapacitors based on two dimensional VO2 nanosheet electrodes in organic gel electrolyte

    KAUST Repository

    Rakhi, R.B.

    2016-10-16

    VO2 is a low band-gap semiconductor with relatively high conductivity among transition metal oxides, which makes it an interesting material for supercapacitor electrode applications. The performance of VO2 as supercapacitor electrode in organic electrolytes has never been reported before. Herein, two-dimensional nanosheets of VO2 are prepared by the simultaneous solution reduction and exfoliation from bulk V2O5 powder by hydrothermal method. A specific capacitance of 405 Fg−1 is achieved for VO2 based supercapacitor in an organic electrolyte, in three electrode configuration. The symmetric capacitor based on VO2 nanosheet electrodes and the liquid organic electrolyte exhibits an energy density of 46 Wh kg−1 at a power density of 1.4 kW kg−1 at a constant current density of 1 Ag−1. Furthermore, flexible solid-state supercapacitors are fabricated using same electrode material and Alumina-silica based gel electrolyte. The solid-state device delivers a specific capacitance of 145 Fg−1 and a device capacitance of 36 Fg−1 at a discharge current density of 1 Ag−1. Series combination of three solid state capacitors is capable of lighting up a red LED for more than 1 minute.

  2. Leaching of manganese from electrolytic manganese residue by electro-reduction.

    Science.gov (United States)

    Shu, Jiancheng; Liu, Renlong; Liu, Zuohua; Chen, Hongliang; Tao, Changyuan

    2017-08-01

    In this study, an improved process for leaching manganese from electrolytic manganese residue (EMR) by electro-reduction was developed. The mechanisms of the electro-reduction leaching were investigated through X-ray diffraction, scanning electron microscopy, X-ray fluorescence, and Brunauer Emmett Teller. The results show that the electric field could change the surface charge distribution of EMR particles, and the high-valent manganese can be reduced by electric field. The leaching efficient of manganese reached 84.1% under the optimal leaching condition: 9.2 wt% H 2 SO 4 , current density of 25 mA/cm 2 , solid-to-liquid ratio of 1:5, and leaching time for 1 h. It is 37.9% higher than that attained without an electric field. Meanwhile, the manganese content in EMR decreased from 2.57% to 0.48%.

  3. Ceria based catalyst for cathode in non-aqueous electrolyte based Li/O2 batteries

    Science.gov (United States)

    Kalubarme, Ramchandra S.; Cho, Min-Seung; Kim, Jae-Kook; Park, Chan-Jin

    2012-11-01

    This study suggests combustion synthesized Ce1-xZrxO2 (CZO; x = 0.1-0.5) as a new catalyst for the cathode in non-aqueous electrolyte based Li/O2 cells. The spherical catalysts have a fluorite structure with a mean diameter of 5-17 nm. Zr doping into the ceria lattice leads to the reduction of Ce4+ to Ce3+, which further improves the catalyst performance. Electrochemical studies of CZO as a cathode catalyst in the Li/O2 cell show that CZO follows a two-electron pathway for oxygen reduction. A maximum discharge capacity of 1620 mAh g-1 is obtained for the Ce0.8Zr0.2O2 catalyst due to its high surface area and porosity. A composite of CZO and MnO2 shows even better performance as a cathode catalyst for the Li/O2 cell.

  4. Small cell experiments for electrolytic reduction of uranium oxides to uranium metal using fluoride salts

    International Nuclear Information System (INIS)

    Haas, P.A.; Adcock, P.W.; Coroneos, A.C.; Hendrix, D.E.

    1994-01-01

    Electrolytic reduction of uranium oxide was proposed for the preparation of uranium metal feed for the atomic vapor laser isotope separation (AVLIS) process. A laboratory cell of 25-cm ID was operated to obtain additional information in areas important to design and operation of a pilot plant cell. Reproducible test results and useful operating and control procedures were demonstrated. About 20 kg of uranium metal of acceptable purity were prepared. A good supply of dissolved UO 2 feed at the anode is the most important controlling requirement for efficient cell operation. A large fraction of the cell current is nonproductive in that it does not produce a metal product nor consume carbon anodes. All useful test conditions gave some reduction of UF 4 to produce CF 4 in addition to the reduction of UO 2 , but the fraction of metal from the reduction of UF 4 can be decreased by increasing the concentration of dissolved UO 2 . Operation of large continuous cells would probably be limited to current efficiencies of less than 60 pct, and more than 20 pct of the metal would result from the reduction of UF 4

  5. Electrochemical hydrogen isotope sensor based on solid electrolytes

    International Nuclear Information System (INIS)

    Matsumoto, Hiroshige; Hayashi, Hiroyuki; Iwahara, Hiroyasu

    2002-01-01

    An electrochemical sensor of hydrogen isotopes based on solid electrolytes for determining the hydrogen isotope ratios and/or total hydrogen pressures in gases has been developed. This paper describes the methodology of the hydrogen isotope sensing together with experimental results. When hydrogen isotope gases are introduced to an electrochemical cell using a proton-conducting electrolyte (hydrogen isotope cell), the electromotive force (EMF) of the cell agrees with that theoretically estimated. The EMF signals can be used for the determination of the hydrogen isotope ratio in gases if the total hydrogen pressure is predetermined. By supplementary use of an oxide ion conductor cell, both the ratio and total pressure of the hydrogen isotopes can be simultaneously determined. (author)

  6. Improved Electrodes and Electrolytes for Dye-Based Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Harry R. Allcock; Thomas E. Mallouk; Mark W. Horn

    2011-10-26

    The most important factor in limiting the stability of dye-sensitized solar cells is the use of volatile liquid solvents in the electrolytes, which causes leakage during extended operation especially at elevated temperatures. This, together with the necessary complex sealing of the cells, seriously hampers the industrial-scale manufacturing and commercialization feasibilities of DSSCs. The objective of this program was to bring about a significant improvement in the performance and longevity of dye-based solar cells leading to commercialization. This had been studied in two ways first through development of low volatility solid, gel or liquid electrolytes, second through design and fabrication of TiO2 sculptured thin film electrodes.

  7. Characterization of Novel Castor Oil-Based Polyurethane Polymer Electrolytes

    Directory of Open Access Journals (Sweden)

    Salmiah Ibrahim

    2015-04-01

    Full Text Available Castor oil-based polyurethane as a renewable resource polymer has been synthesized for application as a host in polymer electrolyte for electrochemical devices. The polyurethane was added with LiI and NaI in different wt% to form a film of polymer electrolytes. The films were characterized by using attenuated total reflectance-Fourier transform infrared spectroscopy, dynamic mechanical analysis, electrochemical impedance spectroscopy, linear sweep voltammetry and transference number measurement. The highest conductivity of 1.42 × 10−6 S cm−1 was achieved with the addition of 30 wt% LiI and 4.28 × 10−7 S·cm−1 upon addition of 30 wt% NaI at room temperature. The temperature dependence conductivity plot indicated that both systems obeyed Arrhenius law. The activation energy for the PU-LiI and PU-NaI systems were 0.13 and 0.22 eV. Glass transition temperature of the synthesized polyurethane decreased from −15.8 °C to ~ −26 to −28 °C upon salts addition. These characterizations exhibited the castor oil-based polyurethane polymer electrolytes have potential to be used as alternative membrane for electrochemical devices.

  8. Formation of TiO2 nanostructure by plasma electrolytic oxidation for Cr(VI) reduction

    Science.gov (United States)

    Torres, D. A.; Gordillo-Delgado, F.; Plazas-Saldaña, J.

    2017-01-01

    Plasma electrolytic oxidation (PEO) is an environmentally friendly technique that allows the growth of ceramic coatings without organic solvents and non-toxic residues. This method was applied to ASME SB-265 titanium (Ti) plates (2×2×0.1cm) using voltage pulses from a switching power supply (340V) for 10 minutes at frequency of 1000Hz changing duty cycle at 10, 60 and 90% and the electrolytes were Na3PO4 and NaOH. The treated sheets surfaces were analysed by X-ray diffraction and scanning electron microscopy. According to the diffractograms, the duty cycle increase produces amorphous TiO2 coating on Ti sheets and the thickness increases. After sintering at 900°C during 1 hour, the 10% duty cycle generated a combination of anatase and rutile phases at the sample surface with weight percentages of 13.3 and 86.6% and particle sizes of 32.461±0.009nm and 141.14±0.03 nm, respectively. With this sample, the total reduction of hexavalent chromium was reached at 50 minutes for 1ppm solution. This photocatalytic activity was measured following the colorimetric method ASTM-3500-Cr B.

  9. Investigation of polymer electrolyte based on agar and ionic liquids

    Directory of Open Access Journals (Sweden)

    M. M. Silva

    2012-12-01

    Full Text Available The possibility to use natural polymer as ionic conducting matrix was investigated in this study. Samples of agarbased electrolytes with different ionic liquids were prepared and characterized by physical and chemical analyses. The ionic liquids used in this work were 1-ethyl-3-methylimidazolium ethylsulfate, [C2mim][C2SO4], 1-ethyl-3-methylimidazolium acetate, [C2mim][OAc] and trimethyl-ethanolammonium acetate, [Ch][OAc]. Samples of solvent-free electrolytes were prepared and characterized by ionic conductivity measurements, thermal analysis, electrochemical stability, X-ray diffraction, scanning electron microscopy and Fourier Transform infrared spectroscopy. Electrolyte samples are thermally stable up to approximately 190°C. All the materials synthesized are semicrystalline. The electrochemical stability domain of all samples is about 2.0 V versus Li/Li+. The preliminary studies carried out with electrochromic devices (ECDs incorporating optimized compositions have confirmed that these materials may perform as satisfactory multifunctional component layers in the field of ‘smart windows’, as well as ECD-based devices.

  10. Na2SO4-based solid electrolytes for SOx sensors

    DEFF Research Database (Denmark)

    Rao, N.; Schoonman, J.; Toft Sørensen, O.

    1992-01-01

    Na2SO4-based solid electrolytes with compositions Na2SO4 + x mol% Y2 (SO4)3 (x = 0, 3,5,6,9,12,15) and Na2SO4 + y mol% La2(SO4)3 (y = 0, 2, 4, 6, 8) were synthesized by solid state reaction. The crystal struCture, phaseS, and, electrical conductivity of these solid electrolytes were studied by XRD......, SEM, EDX, DTA, TGA and impedance spectroscopy. Upon doping with La2 (SO4)3 or Y2(SO4)3 the high-temperature fast-ion conducting phase NaSO4-I can be stabilized down to room temperature. Doping increases the ionic conductivity as well. Of these solid electrolytes the Na2SO4 + 5 mol% Y2(SO4)3 and Na2SO......$ + 4 mol% La2(SO4)3 solid solutions exhibit the highest ionic conductivity values (at 400-degrees-C, 1.76 X 10(-2) S cm-1 and 2.95 X 10(-2) S cm-1, respectively) and lowest activation enthalpies (0.38 eV and 0.37 eV, respectively). When x greater-than-or-equal-to 12 or y greater-than-or-equal-to 8...

  11. Mindfulness-Based Stress Reduction

    Science.gov (United States)

    ... R S T U V W X Y Z Mindfulness-Based Stress Reduction (MBSR) Information 6 Things You ... Disease and Dementia (12/20/13) Research Spotlights Mindfulness-Based Stress Reduction, Cognitive-Behavioral Therapy Shown To ...

  12. The correlation of the properties of pyrrolidinium-based ionic liquid electrolytes with the discharge-charge performances of rechargeable Li-O2 batteries

    Science.gov (United States)

    Li, Yu; Zhang, Zhonglin; Duan, Donghong; Sun, Yanbo; Wei, Guoqiang; Hao, Xiaogang; Liu, Shibin; Han, Yunxia; Meng, Weijuan

    2016-10-01

    Pyrrolidinium-based ionic liquids (ILs), such as PYR13TFSI, PYR14TFSI, and PYR1(2O1)TFSI, exhibit high thermal and electrochemical stability with wide electrochemical windows as electrolytes for application to rechargeable Li-O2 batteries. In this work, several fundamental properties of three ILs are measured: the ionic conductivity, oxygen solubility, and oxygen diffusion coefficient. The oxygen electro-reduction kinetics is characterized using cyclic voltammetry. The performances of Li-O2 batteries with these IL electrolytes are also investigated using electrochemical impedance spectroscopy and galvanostatic discharge-charge tests. The results demonstrate that the PYR1(2O1)TFSI electrolyte battery has a higher first-discharge voltage than the PYR13TFSI electrolyte and PYR14TFSI electrolyte batteries. Both PYR13TFSI- and PYR1(2O1)TFSI-based batteries exhibit higher first-discharge capacities and better cycling stabilities than the PYR14TFSI-based battery for 30 cycles. A theoretical analysis of the experimental results shows that the diffusion coefficient and solubility of oxygen in the electrolyte remarkably affect the discharge capacity and cycling stability of the batteries. Particularly, the oxygen diffusion coefficient of the IL electrolyte can effectively facilitate the electrochemical oxygen electro-reduction reaction and oxygen concentration distribution in the catalyst layers of air electrodes. The oxygen diffusion coefficient and oxygen solubility improvements of IL electrolytes can enhance the discharge-charge performances of Li-O2 batteries.

  13. Effect of an electrolyte salt dissolving in polysiloxane-based electrolyte on passive film formation on a graphite electrode

    Science.gov (United States)

    Nakahara, Hiroshi; Nutt, Steven

    Electrochemical impedance spectroscopy (EIS) was performed during the first charge of a graphite/lithium metal test cell to determine the effect of an electrolyte salt on passive film formation in a polysiloxane-based electrolyte. The graphite electrode was separated from the lithium metal electrode by a porous polyethylene membrane immersed in a polysiloxane-based electrolyte with the dissolved lithium bis(oxalato) borate (LiBOB) or lithium bis(trifluoromethanesulfonyl) imide (LiTFSI). In case of LiTFSI, the conductivity of system decreased at 1.2 V. In contrast, for the case of LiBOB, the conductivity decreased at 1.7 V. The magnitudes of charge transfer resistance and film resistance for LiTFSI were smaller than that for LiBOB. Passive films on highly oriented pyrolytic graphite (HOPG) after charging (lithiating) in polysiloxane-based electrolyte were inspected microscopically. Gel-like film and island-like films were observed for LiBOB [H. Nakahara, A. Masias, S.Y. Yoon, T. Koike, K. Takeya, Proceedings of the 41st Power Sources Conference, vol. 165, Philadelphia, June 14-17, 2004; H. Nakahara, S.Y. Yoon, T. Piao, S. Nutt, F. Mansfeld, J. Power Sources, in press; H. Nakahara, S.Y. Yoon, S. Nutt, J. Power Sources, in press]. However, for LiTFSI, there was sludge accumulation on the HOPG surface. Compositional analysis revealed the presence of silicon on both HOPG specimens with LiBOB and with LiTFSI. The electrolyte salt dissolved in the polysiloxane-based electrolyte changed the electrochemical and morphological nature of passive films on graphite electrode.

  14. A Model-Based Prognostics Methodology For Electrolytic Capacitors Based On Electrical Overstress Accelerated Aging

    Data.gov (United States)

    National Aeronautics and Space Administration — A remaining useful life prediction methodology for electrolytic capacitors is presented. This methodology is based on the Kalman filter framework and an empirical...

  15. Polybenzimidazoles based on high temperature polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Linares Leon, Jose Joaquin; Camargo, Ana Paula M.; Ashino, Natalia M.; Morgado, Daniella L.; Frollini, Elisabeth; Paganin, Valdecir A.; Gonzalez, Ernesto Rafael [Universidade de Sao Paulo (IQSC/USP), Sao Carlos, SP (Brazil); Bajo, Justo Lobato [University of Castilla-La Mancha, Ciudad Real (Spain). Dept. of Chemical Engineering

    2010-07-01

    This work presents an interesting approach in order to enhance the performance of Polymer Electrolyte Membrane Fuel Cells (PEMFC) by means of an increase in the operational temperature. For this, two polymeric materials, Poly(2,5-bibenzimidazole) (ABPBI) and Poly[2,2'-(m-phenyl en)-5,5' bib enzimidazol] (PBI), impregnated with phosphoric acid have been utilized. These have shown excellent properties, such as thermal stability above 500 deg C, reasonably high conductivity when impregnated with H{sub 3}PO{sub 4} and a low permeability to alcohols compared to Nafion. Preliminary fuel cells measurements on hydrogen based Polymer Electrolyte Membrane Fuel Cell (PEMFC) displayed an interestingly reasonable good fuel cell performance, a quite reduced loss when the hydrogen stream was polluted with carbon monoxide, and finally, when the system was tested with an ethanol/water (E/W) fuel, it displayed quite promising results that allows placing this system as an attractive option in order to increase the cell performance and deal with the typical limitations of low temperature Nafion-based PEMFC. (author)

  16. New polymer lithium secondary batteries based on ORMOCER (R) electrolytes-inorganic-organic polymers

    DEFF Research Database (Denmark)

    Popall, M.; Buestrich, R.; Semrau, G.

    2001-01-01

    Based on new plasticized inorganic-organic polymer electrolytes CM. Popall, M. Andrei, J. Kappel, J. Kron, K. Olma, B. Olsowski,'ORMOCERs as Inorganic-organic Electrolytes for New Solid State Lithium Batteries and Supercapacitors', Electrochim. Acta 43 (1998) 1155] new flexible foil-batteries...... electrolyte, typical for polymer electrolytes. Cycling tests (more than 900 cycles) proved that the unplasticized electrolyte can act as binder in composite cathodes of lithium secondary batteries [2]. Charge/discharge cycles of complete batteries like (Cu/active carbon/ORMOCER(R)/LiCoO2/Al) with an ORMOCER......(R) as separator electrolyte were measured. The voltage drop of these batteries is very similar to cells with standard liquid electrolytes and the efficiency is close to 100%. Cycling the batteries with a current density of 0.25 mA cm(-2) between the voltage limits of 3.1 and 4.1 V results in a charge...

  17. A method for calculating the acid-base equilibria in aqueous and nonaqueous electrolyte solutions

    Science.gov (United States)

    Tanganov, B. B.; Alekseeva, I. A.

    2017-06-01

    Concentrations of particles in acid-base equilibria in aqueous and nonaqueous solutions of electrolytes are calculated on the basis of logarithmic charts, activity coefficients, and equilibrium constants.

  18. Physics Based Modeling and Prognostics of Electrolytic Capacitors

    Science.gov (United States)

    Kulkarni, Chetan; Ceyla, Jose R.; Biswas, Gautam; Goebel, Kai

    2012-01-01

    This paper proposes first principles based modeling and prognostics approach for electrolytic capacitors. Electrolytic capacitors have become critical components in electronics systems in aeronautics and other domains. Degradations and faults in DC-DC converter unit propagates to the GPS and navigation subsystems and affects the overall solution. Capacitors and MOSFETs are the two major components, which cause degradations and failures in DC-DC converters. This type of capacitors are known for its low reliability and frequent breakdown on critical systems like power supplies of avionics equipment and electrical drivers of electromechanical actuators of control surfaces. Some of the more prevalent fault effects, such as a ripple voltage surge at the power supply output can cause glitches in the GPS position and velocity output, and this, in turn, if not corrected will propagate and distort the navigation solution. In this work, we study the effects of accelerated aging due to thermal stress on different sets of capacitors under different conditions. Our focus is on deriving first principles degradation models for thermal stress conditions. Data collected from simultaneous experiments are used to validate the desired models. Our overall goal is to derive accurate models of capacitor degradation, and use them to predict performance changes in DC-DC converters.

  19. A study of integrated cathode assembly for electrolytic reduction of uranium oxide in LiCl-Li2O molten salt

    International Nuclear Information System (INIS)

    Park, Sung Bin; Seo, Jung Seok; Kang, Dae Seung; Kwon, Sun Kil; Park, Seong Won

    2004-01-01

    Interest of electrolytic reduction of uranium oxide is increasing in treatment of spent metal fuels. Argonne National Laboratory (ANL) has reported the experimental results of electrochemical reduction of uranium oxide fuel in bench-scale apparatus with cyclic voltammetry, and has designed high-capacity reduction (HCR) cells and conducted three kg-scale UO 2 reduction runs. From the cyclic voltammograms, the mechanism of electrolytic reduction of metal oxides is analyzed. The uranium oxide in LiCl-Li 2 O is converted to uranium metal according to the two mechanism; direct and indirect electrolytic reduction. In this study, cyclic voltammograms for LiCl-3wt% Li 2 O system and U 3 O 8 -LiCl-3wt% Li 2 O system using the 325-mesh stainless steel screen in cathode assembly have been obtained. Direct electrolytic reduction of uranium oxide in LiCl-3wt% Li 2 O molten salt has been conducted

  20. Safer lithium ion batteries based on nonflammable electrolyte

    Science.gov (United States)

    Zeng, Ziqi; Wu, Bingbin; Xiao, Lifen; Jiang, Xiaoyu; Chen, Yao; Ai, Xinping; Yang, Hanxi; Cao, Yuliang

    2015-04-01

    The safety of lithium ion batteries has long been a critical obstacle for their high-power and large-scale applications because of the flammable nature of their carbon anode and organic carbonate electrolytes. To eliminate the potential safety hazards, lithium ion batteries should be built up with thermal-stable electrodes and nonflammable electrolytes. Here we report safer lithium ion batteries using nonflammable phosphonate electrolyte, thermal-stable LiFePO4 cathode and alloy anodes. Benefiting from the electrochemical compatibility and strong fire-retardancy of the phosphonate electrolyte, the cathode and anode materials in the nonflammable phosphonate electrolyte demonstrate similar charge-discharge performances with those in the conventional carbonate electrolyte, showing a great prospect for large-scale applications in electric vehicles and grid-scale electric energy storage.

  1. Composite, Polymer-Based Electrolytes for Advanced Batteries

    National Research Council Canada - National Science Library

    Ratner, Mark A

    2001-01-01

    .... Several substantive advances towards new, improved performance electrolyte materials both for low temperature fuel cell applications and for advanced secondary lithium battery materials have been reported...

  2. Separation and Recovery of Uranium Metal from Spent Light Water Reactor Fuel via Electrolytic Reduction and Electrorefining

    International Nuclear Information System (INIS)

    Herrmann, S.D.; Li, S.X.

    2010-01-01

    A series of bench-scale experiments was performed in a hot cell at Idaho National Laboratory to demonstrate the separation and recovery of uranium metal from spent light water reactor (LWR) oxide fuel. The experiments involved crushing spent LWR fuel to particulate and separating it from its cladding. Oxide fuel particulate was then converted to metal in a series of six electrolytic reduction runs that were performed in succession with a single salt loading of molten LiCl - 1 wt% Li2O at 650 C. Analysis of salt samples following the series of electrolytic reduction runs identified the diffusion of select fission products from the spent fuel to the molten salt electrolyte. The extents of metal oxide conversion in the post-test fuel were also quantified, including a nominal 99.7% conversion of uranium oxide to metal. Uranium metal was then separated from the reduced LWR fuel in a series of six electrorefining runs that were performed in succession with a single salt loading of molten LiCl-KCl-UCl3 at 500 C. Analysis of salt samples following the series of electrorefining runs identified additional partitioning of fission products into the molten salt electrolyte. Analyses of the separated uranium metal were performed, and its decontamination factors were determined.

  3. based anion exchange membrane for alkaline polymer electrolyte

    Indian Academy of Sciences (India)

    Administrator

    Alkaline polymer electrolyte fuel cell; anion exchange membrane; PPO; homogeneous quaterni- zation. 1. Introduction. Presently, alkaline polymer electrolyte fuel cells (APEFCs) using anion exchange membranes have received an immense interest among researchers (Varcoe and Slade. 2005). The advantages of ...

  4. Performance limitations of polymer electrolytes based on ethylene oxide polymers

    International Nuclear Information System (INIS)

    Buriez, Olivier; Han, Yong Bong; Hou, Jun; Kerr, John B.; Qiao, Jun; Sloop, Steven E.; Tian, Minmin; Wang, Shanger

    1999-01-01

    Studies of polymer electrolyte solutions for lithium-polymer batteries are described. Two different salts, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium trifluoromethanesulfonate (LiTf), were dissolved in a variety of polymers. The structures were all based upon the ethylene oxide unit for lithium ion solvation and both linear and comb-branch polymer architectures have been examined. Conductivity, salt diffusion coefficient and transference number measurements demonstrate the superior transport properties of the LiTFSI salt over LiTf. Data obtained on all of these polymers combined with LiTFSI salts suggest that there is a limit to the conductivity achievable at room temperature, at least for hosts containing ethylene oxide units. The apparent conductivity limit is 5 x 10-5 S/cm at 25 C. Providing that the polymer chain segment containing the ethylene oxide units is at least 5-6 units long there appears to be little influence of the polymer framework to which the solvating groups are attached. To provide adequate separator function, the mechanical properties may be disconnected from the transport properties by selection of an appropriate architecture combined with an adequately long ethylene oxide chain. For both bulk and interfacial transport of the lithium ions, conductivity data alone is insufficient to understand the processes that occur. Lithium ion transference numbers and salt diffusion coefficients also play a major role in the observed behavior and the transport properties of these polymer electrolyte solutions appear to be quite inadequate for ambient temperature performance. At present, this restricts the use of such systems to high temperature applications. Several suggestions are given to overcome these obstacles

  5. Preparation and physicochemical properties of surfactant-free emulsions using electrolytic-reduction ion water containing lithium magnesium sodium silicate.

    Science.gov (United States)

    Okajima, Masahiro; Wada, Yuko; Hosoya, Takashi; Hino, Fumio; Kitahara, Yoshiyasu; Shimokawa, Ken-ichi; Ishii, Fumiyoshi

    2013-04-01

    Surfactant-free emulsions by adding jojoba oil, squalane, olive oil, or glyceryl trioctanoate (medium chain fatty acid triglycerides, MCT) to electrolytic-reduction ion water containing lithium magnesium sodium silicate (GE-100) were prepared, and their physiochemical properties (thixotropy, zeta potential, and mean particle diameter) were evaluated. At an oil concentration of 10%, the zeta potential was ‒22.3 ‒ ‒26.8 mV, showing no marked differences among the emulsions of various types of oil, but the mean particle diameters in the olive oil emulsion (327 nm) and MCT emulsion (295 nm) were smaller than those in the other oil emulsions (452-471 nm). In addition, measurement of the hysteresis loop area of each type of emulsion revealed extremely high thixotropy of the emulsion containing MCT at a low concentration and the olive emulsion. Based on these results, since surfactants and antiseptic agents markedly damage sensitive skin tissue such as that with atopic dermatitis, surfactant- and antiseptic-free emulsions are expected to be new bases for drugs for external use.

  6. Progress in electrolytes for rechargeable Li-based batteries and beyond

    Directory of Open Access Journals (Sweden)

    Qi Li

    2016-04-01

    Full Text Available Owing to almost unmatched volumetric energy density, Li-based batteries have dominated the portable electronic industry for the past 20 years. Not only will that continue, but they are also now powering plug-in hybrid electric vehicles and zero-emission vehicles. There is impressive progress in the exploration of electrode materials for lithium-based batteries because the electrodes (mainly the cathode are the limiting factors in terms of overall capacity inside a battery. However, more and more interests have been focused on the electrolytes, which determines the current (power density, the time stability, the reliability of a battery and the formation of solid electrolyte interface. This review will introduce five types of electrolytes for room temperature Li-based batteries including 1 non-aqueous electrolytes, 2 aqueous solutions, 3 ionic liquids, 4 polymer electrolytes, and 5 hybrid electrolytes. Besides, electrolytes beyond lithium-based systems such as sodium-, magnesium-, calcium-, zinc- and aluminum-based batteries will also be briefly discussed. Keywords: Electrolyte, Ionic liquid, Polymer, Hybrid, Battery

  7. Monitoring the Electrolytic Reduction Process of Metal Oxide in the LiCl Molten Salt at 650 . deg. C

    International Nuclear Information System (INIS)

    Choi, In kyu; Hong, Soon Seok; Jung, Myoung Soo; Hur, Jin Mok; Lee, Han Soo

    2010-01-01

    During the electrolytic reduction process of metal oxides, metal oxides are reduced in the cathode basket and oxide ions are oxidized at a platinum anode. Basically the oxide concentration in the bulk should be maintained to be constant during the reduction process, but slow diffusion rate of oxide ions from metal oxide particles to the salt medium results in decreasing the oxide ion concentration. When a high current density is applied for the reduction, lowered lithium oxide concentration causes the platinum anode to be dissolved. To accomplish the reduction of metal oxides without serious damage of platinum anode, monitoring the lithium oxide concentration is very important. For in-situ monitoring the oxide concentration during the reduction, cyclic voltammetry (CV) and chronoamperometry(CA) were applied

  8. The NASA "PERS" Program: Solid Polymer Electrolyte Development for Advanced Lithium-Based Batteries

    Science.gov (United States)

    Baldwin, Richard S.; Bennett, William R.

    2007-01-01

    In fiscal year 2000, The National Aeronautics and Space Administration (NASA) and the Air Force Research Laboratory (AFRL) established a collaborative effort to support the development of polymer-based, lithium-based cell chemistries and battery technologies to address the next generation of aerospace applications and mission needs. The ultimate objective of this development program, which was referred to as the Polymer Energy Rechargeable System (PERS), was to establish a world-class technology capability and U.S. leadership in polymer-based battery technology for aerospace applications. Programmatically, the PERS initiative exploited both interagency collaborations to address common technology and engineering issues and the active participation of academia and private industry. The initial program phases focused on R&D activities to address the critical technical issues and challenges at the cell level. Out of a total of 38 proposals received in response to a NASA Research Announcement (NRA) solicitation, 18 proposals (13 contracts and 5 grants) were selected for initial award to address these technical challenges. Brief summaries of technical approaches, results and accomplishments of the PERS Program development efforts are presented. With Agency support provided through FY 2004, the PERS Program efforts were concluded in 2005, as internal reorganizations and funding cuts resulted in shifting programmatic priorities within NASA. Technically, the PERS Program participants explored, to various degrees over the lifetime of the formal program, a variety of conceptual approaches for developing and demonstrating performance of a viable advanced solid polymer electrolyte possessing the desired attributes, as well as several participants addressing all components of an integrated cell configuration. Programmatically, the NASA PERS Program was very successful, even though the very challenging technical goals for achieving a viable solid polymer electrolyte material or

  9. Stretchable supercapacitors based on highly stretchable ionic liquid incorporated polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Tamilarasan, P.; Ramaprabhu, S., E-mail: ramp@iitm.ac.in

    2014-11-14

    Mechanical stability of electrolyte in all-solid-state supercapacitor attains immense attention as it addresses safety aspects. In this study, we have demonstrated, the fabrication of stretchable supercapacitor based on stretchable electrolyte and hydrogen exfoliated graphene electrode. We synthesized ionic liquid incorporated stretchable Poly(methyl methacrylate) electrolyte which plays dual role as electrolyte and stretchable support for electrode material. The molecular vibration studies show composite nature of the electrolyte. At least four-fold stretchability has been observed along with good ionic conductivity (0.78 mS cm{sup −1} at 28 °C) for this polymer electrolyte. This stretchable supercapacitor shows a low equivalent series resistance (16 Ω) due to the compatibility at electrode–electrolyte interface. The performance of the device has been determined under strain as well. - Highlights: • A stretchable supercapacitor has been fabricated using stretchable electrolyte. • Here ionic liquid incorporated polymer plays dual role as electrolyte and stretchable support. • The developed device shows low equivalent series resistance. • The device has specific capacitance of 83 F g{sup −1}, at the specific current of 2.67 A g{sup −1}. • The energy density and power density of 25.7 Wh kg{sup −1} and 35.2 kW kg{sup −1}, respectively.

  10. Dye-sensitized solar cells based on electrospun polyacrylonitrile (PAN) nanofibre membrane gel electrolyte

    International Nuclear Information System (INIS)

    Dissanayake, M.A.K.L.; Divarathne, H.K.D.W.M.N.R.; Thotawatthage, C.A.; Dissanayake, C.B.; Senadeera, G.K.R.; Bandara, B.M.R.

    2014-01-01

    Highlights: • Dye sensitized solar cells based on nanofibre membrane gel electrolyte, PAN:KI:PC:I 2 were fabricated and characterized. • The solar cell with membrane electrolyte of thickness 9.14 μm showed the highest efficiency of 5.2%. • An identical solar cell based on corresponding liquid electrolyte showed an efficiency of 5.3%. • The open circuit voltage and short circuit current density of the nanofibre based solar cell were 0.67 V and 13.31 mA cm −2 . • Dye solar cells with nanofibre gel electrolytes can yield efficiencies comparable to cells with solution electrolytes. - Abstract: Dye Sensitized Solar Cells (DSSCs) based on electrospun nanofibre membrane electrolytes offer several advantages over liquid electrolyte based solar cells. Nanofibre membranes having different thicknesses were prepared by electrospinning on platinum electrodes from a 11 wt% solution of polyacrylonitrile (PAN) in N,N-dimethylformamide (DMF) at an applied voltage of 8 kV. The membranes were then activated by immersing in a solution containing potassium iodide (KI) (0.06 g), propylene carbonate (PC) (0.8 g) and iodine (I 2 ) (0.0092 g) for 30 minutes to obtain “gel” type membrane electrolytes with different thicknesses. These nanofibre membrane electrolytes were used to fabricate quasi-solid state (gel) DSSCs and the performance of these solar cells were compared with DSSCs fabricated with liquid electrolyte (KI:PC:I 2 ) and conventional PAN based gel electrolyte (PAN:KI:PC:I 2 ). DSSC with nanofibre membrane electrolyte of thickness 9.14 μm showed the highest light-to-electricity conversion efficiency of 5.2% whereas an identical cell based on corresponding liquid electrolyte showed an efficiency of 5.3%. The open circuit voltage (V OC ), short circuit current density (J Sc ) and fill factor for the solar cell based on this electrolyte was 0.67 V, 13.31 mA cm −2 and 59% respectively at an incident light intensity of 1000 W m −2 with a 1.5 AM filter

  11. Virus-Assembled Flexible Electrode-Electrolyte Interfaces for Enhanced Polymer-Based Battery Applications

    Directory of Open Access Journals (Sweden)

    Ayan Ghosh

    2012-01-01

    Full Text Available High-aspect-ratio cobalt-oxide-coated Tobacco mosaic virus (TMV- assembled polytetrafluoroethylene (PTFE nonstick surfaces were integrated with a solvent-free polymer electrolyte to create an anode-electrolyte interface for use in lithium-ion batteries. The virus-assembled PTFE surfaces consisted primarily of cobalt oxide and were readily intercalated with a low-molecular-weight poly (ethylene oxide (PEO based diblock copolymer electrolyte to produce a solid anode-electrolyte system. The resulting polymer-coated virus-based system was then peeled from the PTFE backing to produce a flexible electrode-electrolyte component. Electrochemical studies indicated the virus-structured metal-oxide PEO-based interface was stable and displayed robust charge transfer kinetics. Combined, these studies demonstrate the development of a novel solid-state electrode architecture with a unique peelable and flexible processing attribute.

  12. Supercapacitors Based on Activated Carbon and Polymer Electrolyte

    OpenAIRE

    M. A. Hashim; Lawal Sa’adu; Karsono A. Dasuki

    2012-01-01

    The supercapacitors are characterized by faster discharge rate and easy for maintenance. Their demand is predicted to be most extensive in frequency regulation applications. The other area for significant growth is in regenerative braking for grid, connected light rail systems. In this research we fabricated a Supercapacitor using a commercially prepared Activated carbon which was sized to an area of 1 cm2 and combinations of two electrolytes solutions; polymer electrolyte polyvinyl alcohol (...

  13. Poly(vinylidene fluoride-hexafluoropropylene polymer electrolyte for paper-based and flexible battery applications

    Directory of Open Access Journals (Sweden)

    Nojan Aliahmad

    2016-06-01

    Full Text Available Paper-based batteries represent a new frontier in battery technology. However, low-flexibility and poor ionic conductivity of solid electrolytes have been major impediments in achieving practical mechanically flexible batteries. This work discuss new highly ionic conductive polymer gel electrolytes for paper-based battery applications. In this paper, we present a poly(vinylidene fluoride-hexafluoropropylene (PVDH-HFP porous membrane electrolyte enhanced with lithium bis(trifluoromethane sulphoneimide (LiTFSI and lithium aluminum titanium phosphate (LATP, with an ionic conductivity of 2.1 × 10−3 S cm−1. Combining ceramic (LATP with the gel structure of PVDF-HFP and LiTFSI ionic liquid harnesses benefits of ceramic and gel electrolytes in providing flexible electrolytes with a high ionic conductivity. In a flexibility test experiment, bending the polymer electrolyte at 90° for 20 times resulted in 14% decrease in ionic conductivity. Efforts to further improving the flexibility of the presented electrolyte are ongoing. Using this electrolyte, full-cell batteries with lithium titanium oxide (LTO and lithium cobalt oxide (LCO electrodes and (i standard metallic current collectors and (ii paper-based current collectors were fabricated and tested. The achieved specific capacities were (i 123 mAh g−1 for standard metallic current collectors and (ii 99.5 mAh g−1 for paper-based current collectors. Thus, the presented electrolyte has potential to become a viable candidate in paper-based and flexible battery applications. Fabrication methods, experimental procedures, and test results for the polymer gel electrolyte and batteries are presented and discussed.

  14. Poly(vinylidene fluoride-hexafluoropropylene) polymer electrolyte for paper-based and flexible battery applications

    Energy Technology Data Exchange (ETDEWEB)

    Aliahmad, Nojan; Shrestha, Sudhir; Varahramyan, Kody [Department of Electrical & Computer Engineering, Indiana University-Purdue University Indianapolis (IUPUI), Indianapolis, IN, 46202 (United States); Integrated Nanosystems Development Institute (INDI), Indiana University-Purdue University Indianapolis (IUPUI), Indianapolis, IN, 46202 (United States); Agarwal, Mangilal, E-mail: agarwal@iupui.edu [Department of Electrical & Computer Engineering, Indiana University-Purdue University Indianapolis (IUPUI), Indianapolis, IN, 46202 (United States); Integrated Nanosystems Development Institute (INDI), Indiana University-Purdue University Indianapolis (IUPUI), Indianapolis, IN, 46202 (United States); Department of Mechanical Engineering, Indiana University-Purdue University Indianapolis (IUPUI), Indianapolis, IN, 46202 (United States)

    2016-06-15

    Paper-based batteries represent a new frontier in battery technology. However, low-flexibility and poor ionic conductivity of solid electrolytes have been major impediments in achieving practical mechanically flexible batteries. This work discuss new highly ionic conductive polymer gel electrolytes for paper-based battery applications. In this paper, we present a poly(vinylidene fluoride-hexafluoropropylene) (PVDH-HFP) porous membrane electrolyte enhanced with lithium bis(trifluoromethane sulphone)imide (LiTFSI) and lithium aluminum titanium phosphate (LATP), with an ionic conductivity of 2.1 × 10{sup −3} S cm{sup −1}. Combining ceramic (LATP) with the gel structure of PVDF-HFP and LiTFSI ionic liquid harnesses benefits of ceramic and gel electrolytes in providing flexible electrolytes with a high ionic conductivity. In a flexibility test experiment, bending the polymer electrolyte at 90° for 20 times resulted in 14% decrease in ionic conductivity. Efforts to further improving the flexibility of the presented electrolyte are ongoing. Using this electrolyte, full-cell batteries with lithium titanium oxide (LTO) and lithium cobalt oxide (LCO) electrodes and (i) standard metallic current collectors and (ii) paper-based current collectors were fabricated and tested. The achieved specific capacities were (i) 123 mAh g{sup −1} for standard metallic current collectors and (ii) 99.5 mAh g{sup −1} for paper-based current collectors. Thus, the presented electrolyte has potential to become a viable candidate in paper-based and flexible battery applications. Fabrication methods, experimental procedures, and test results for the polymer gel electrolyte and batteries are presented and discussed.

  15. New polymer lithium secondary batteries based on ORMOCER (R) electrolytes-inorganic-organic polymers

    DEFF Research Database (Denmark)

    Popall, M.; Buestrich, R.; Semrau, G.

    2001-01-01

    Based on new plasticized inorganic-organic polymer electrolytes CM. Popall, M. Andrei, J. Kappel, J. Kron, K. Olma, B. Olsowski,'ORMOCERs as Inorganic-organic Electrolytes for New Solid State Lithium Batteries and Supercapacitors', Electrochim. Acta 43 (1998) 1155] new flexible foil-batteries in ......Based on new plasticized inorganic-organic polymer electrolytes CM. Popall, M. Andrei, J. Kappel, J. Kron, K. Olma, B. Olsowski,'ORMOCERs as Inorganic-organic Electrolytes for New Solid State Lithium Batteries and Supercapacitors', Electrochim. Acta 43 (1998) 1155] new flexible foil......-batteries in 'coffee bag arrangement' were assembled and tested. The electrolyte works as separator and binder for the cathodes. Self-diffusion NMR studies on the system (EC/PC/Li+N(SO2CF3)(2)(-)/ORMOCER(R)) resulted in cationic transport numbers t(+)) of 0.42 for the EC/PC/salt system and 0.35 for the ternary...

  16. PVDF-HFP-based porous polymer electrolyte membranes for lithium-ion batteries

    DEFF Research Database (Denmark)

    Miao, Ruiying; Liu, Bowen; Zhu, Zhongzheng

    2008-01-01

    As a potential electrolyte for lithium-ion batteries, a porous polymer electrolyte membrane based on poly(vinylidenefluoride-hexafluoropropylene) (PVDF-HFP) was prepared by a phase inversion method. The casting solution, effects of the solvent and non-solvent and addition of micron scale TiO2 par...... particles to the polymer electrolyte was found to enhance the tensile strength, electrolyte uptake, ion conductivity and the electrolyte/electrode interfacial stability of the membrane.......As a potential electrolyte for lithium-ion batteries, a porous polymer electrolyte membrane based on poly(vinylidenefluoride-hexafluoropropylene) (PVDF-HFP) was prepared by a phase inversion method. The casting solution, effects of the solvent and non-solvent and addition of micron scale TiO2...... particles were investigated. The membranes were characterized by SEM, XRD, AC impedance, and charge/discharge tests. By using acetone as the solvent and water as the non-solvent, the prepared membranes showed good ability to absorb and retain the lithium ion containing electrolyte. Addition of micron TiO2...

  17. Electrical, structural, thermal and electrochemical properties of corn starch-based biopolymer electrolytes.

    Science.gov (United States)

    Liew, Chiam-Wen; Ramesh, S

    2015-06-25

    Biopolymer electrolytes containing corn starch, lithium hexafluorophosphate (LiPF6) and ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (BmImPF6) are prepared by solution casting technique. Temperature dependence-ionic conductivity studies reveal Vogel-Tamman-Fulcher (VTF) relationship which is associated with free volume theory. Ionic liquid-based biopolymer electrolytes show lower glass transition temperature (Tg) than ionic liquid-free biopolymer electrolyte. X-ray diffraction (XRD) studies demonstrate higher amorphous region of ionic liquid-added biopolymer electrolytes. In addition, the potential stability window of the biopolymer electrolyte becomes wider and stable up to 2.9V. Conclusively, the fabricated electric double layer capacitor (EDLC) shows improved electrochemical performance upon addition of ionic liquid into the biopolymer electrolyte. The specific capacitance of EDLC based on ionic liquid-added polymer electrolyte is relatively higher than that of ionic liquid-free polymer electrolyte as depicted in cyclic voltammogram. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Study of the Electrolytic Reduction of Uranium Oxide in LiCl-Li2O Molten Salts with an Integrated Cathode Assembly

    International Nuclear Information System (INIS)

    Park, Sung Bin; Seo, Chung Seok; Kang, Dae Seung; Kwon, Seon Gil; Park, Seong Won

    2005-01-01

    The electrolytic reduction of uranium oxide in a LiCl-Li 2 O molten salt system has been studied in a 10 g U 3 O 3 /batch-scale experimental apparatus with an integrated cathode assembly at 650 .deg. C. The integrated cathode assembly consists of an electric conductor, the uranium oxide to be reduced and the membrane for loading the uranium oxide. From the cyclic voltammograms for the LiCl-3 wt% Li 3 O system and the U 3 O 3 -LiCl-3 wt% Li 2 O system according to the materials of the membrane in the cathode assembly, the mechanisms of the predominant reduction reactions in the electrolytic reactor cell were to be understood; direct and indirect electrolytic reduction of uranium oxide. Direct and indirect electrolytic reductions have been performed with the integrated cathode assembly. Using the 325-mesh stainless steel screen the uranium oxide failed to be reduced to uranium metal by a direct and indirect electrolytic reduction because of a low current efficiency and with the porous magnesia membrane the uranium oxide was reduced successfully to uranium metal by an indirect electrolytic reduction because of a high current efficiency.

  19. Carbonaceous anodes for lithium-ion batteries in combination with protic ionic liquids-based electrolytes

    Science.gov (United States)

    Menne, Sebastian; Schroeder, Matthias; Vogl, Thomas; Balducci, Andrea

    2014-11-01

    Protic ionic liquids (PILs) have been recently proposed as a new class of electrolytes for lithium-ion batteries (LIBs). So far, PILs-based electrolytes have been used in combination with several battery materials, but never with carbonaceous anodes. Since graphite is the state-of-the-art anode in LIBs, the use of PILs-based electrolyte in combination with this material appears of particular importance. In this work we showed, for the first time, that PILs-based electrolytes can be successfully used also in combination with graphite. Even if the lithium intercalation and deintercalation process of these electrode materials occur outside the ESW of PILs, the addition of film-forming additive makes possible the formation of a stable SEI and, consequently, the use of PILs-based electrolytes. The results of this study indicate that the performance of graphite electrode in PILs-based electrolytes is comparable, and even slightly higher, than that observed in AIL-based electrolytes.

  20. Polymer electrolytes based on aromatic lithium sulfonyl-imide compounds; Electrolytes polymeres a base de sulfonylimidures de lithium aromatiques

    Energy Technology Data Exchange (ETDEWEB)

    Reibel, L.; Bayoudh, S. [Centre National de la Recherche Scientifique (CNRS), 67 - Strasbourg (France). Institut Charles Sadron; Baudry, P. [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches; Majastre, H. [Bollore Technologies, 29 - Quimper (France); Herlem, G. [UFR de Sciences et Techniques, L.E.S., 25 - Besancon (France)

    1996-12-31

    This paper presents ionic conductivity results obtained with polymer electrolytes and also with propylene carbonate solutions. The domain of electrochemical activity of this salt has been determined using cycle volt-amperometry in propylene carbonate. Preliminary experiments on the stability of the polymer electrolyte with respect to the lithium electrode have been carried out for a possible subsequent use in lithium batteries. (J.S.) 4 refs.

  1. Acid-Base and Electrolyte Disorders in Patients with and without Chronic Kidney Disease: An Update.

    Science.gov (United States)

    Dhondup, Tsering; Qian, Qi

    2017-12-01

    Kidneys play a pivotal role in the maintenance and regulation of acid-base and electrolyte homeostasis, which is the prerequisite for numerous metabolic processes and organ functions in the human body. Chronic kidney diseases compromise the regulatory functions, resulting in alterations in electrolyte and acid-base balance that can be life-threatening. In this review, we discuss the renal regulations of electrolyte and acid-base balance and several common disorders including metabolic acidosis, alkalosis, dysnatremia, dyskalemia, and dysmagnesemia. Common disorders in chronic kidney disease are also discussed. The most recent and relevant advances on pathophysiology, clinical characteristics, diagnosis, and management of these conditions have been incorporated.

  2. Magnesium-based energy storage systems and methods having improved electrolytes

    Science.gov (United States)

    Liu, Tianbiao; Li, Guosheng; Liu, Jun; Shao, Yuyan

    2016-12-20

    Electrolytes for Mg-based energy storage devices can be formed from non-nucleophilic Mg.sup.2+ sources to provide outstanding electrochemical performance and improved electrophilic susceptibility compared to electrolytes employing nucleophilic sources. The instant electrolytes are characterized by high oxidation stability (up to 3.4 V vs Mg), improved electrophile compatibility and electrochemical reversibility (up to 100% coulombic efficiency). Synthesis of the Mg.sup.2+ electrolytes utilizes inexpensive and safe magnesium dihalides as non-nucleophilic Mg.sup.2+ sources in combination with Lewis acids, MR.sub.aX.sub.3-a (for 3.gtoreq.a.gtoreq.1). Furthermore, addition of free-halide-anion donors can improve the coulombic efficiency of Mg electrolytes from nucleophilic or non-nucleophilic Mg.sup.2+ sources.

  3. A study for an electrolytic reduction of tantalum oxide in a LiCl-Li2O molten salt

    International Nuclear Information System (INIS)

    Park, Sung Bin; Park, Byung Heung; Seo, Chung Seok; Kang, Dae Seung; Kwon, Seon Gil; Park, Seong Won

    2005-01-01

    Korea Atomic Energy Research Institute (KAERI) has developed the Advanced Spent Fuel Conditioning Process (ACP) to be an innovative technology for handling the PWR spent fuel. As part of ACP, the electrolytic reduction process (ER process) is the electrochemical reduction process of uranium oxide to uranium metal in a molten salt. The ER process has advantages in a technical stability, an economic potential and a good proliferation resistance. KAERI has reported on the good experimental results of an electrochemical reduction of the uranium oxide in a 20 kg HM/batch lab-scale. The ER process can be applicable to the reduction of other metal oxides. Metal tantalum powder has attracted attention for a variety of applications. A tantalum capacitor made from superfine and pliable tantalum powders is very small in size and it has a higher-capacitance part, therefore it is useful for microelectronic devices. By the ER process the metal tantalum can be obtained from tantalum pentoxide. In this work, a 40 g Ta 2 O 5 /batch electrochemical reactor was used for the synthesis of the metal tantalum. From the results of the cyclic voltammograms for the Ta 2 O 5 -LiCl-Li 2 O system, the mechanism of the tantalum reduction in a molten LiCl-Li 2 O salt system was investigated. Tantalum pentoxide is chemically reduced to tantalum metal by the lithium metal which is electrochemically deposited into an integrated cathode assembly in the LiCl-Li 2 O molten salt. The experiments for the tantalum reduction were performed with a chronopotentiometry in the reactor cell, the reduced products were analyzed from an analysis of the X-ray diffraction (XRD), scanning electron microscope and energy dispersive X-ray (SEM-EDX). From the results, the electrolytic reduction process is applicable to the synthesis of metal tantalum

  4. Alkoxide-based magnesium electrolyte compositions for magnesium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Sheng; Sun, Xiao-Guang; Liao, Chen; Guo, Bingkun

    2018-01-30

    Alkoxide magnesium halide compounds having the formula: RO--Mg--X (1) wherein R is a saturated or unsaturated hydrocarbon group that is unsubstituted, or alternatively, substituted with one or more heteroatom linkers and/or one or more heteroatom-containing groups comprising at least one heteroatom selected from fluorine, nitrogen, oxygen, sulfur, and silicon; and X is a halide atom. Also described are electrolyte compositions containing a compound of Formula (1) in a suitable polar aprotic or ionic solvent, as well as magnesium batteries in which such electrolytes are incorporated.

  5. High-performance Platinum-free oxygen reduction reaction and hydrogen oxidation reaction catalyst in polymer electrolyte membrane fuel cell.

    Science.gov (United States)

    Chandran, Priji; Ghosh, Arpita; Ramaprabhu, Sundara

    2018-02-26

    The integration of polymer electrolyte membrane fuel cell (PEMFC) stack into vehicles necessitates the replacement of high-priced platinum (Pt)-based electrocatalyst, which contributes to about 45% of the cost of the stack. The implementation of high-performance and durable Pt metal-free catalyst for both oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR) could significantly enable large-scale commercialization of fuel cell-powered vehicles. Towards this goal, a simple, scalable, single-step synthesis method was adopted to develop palladium-cobalt alloy supported on nitrogen-doped reduced graphene oxide (Pd 3 Co/NG) nanocomposite. Rotating ring-disk electrode (RRDE) studies for the electrochemical activity towards ORR indicates that ORR proceeds via nearly four-electron mechanism. Besides, the mass activity of Pd 3 Co/NG shows an enhancement of 1.6 times compared to that of Pd/NG. The full fuel cell measurements were carried out using Pd 3 Co/NG at the anode, cathode in conjunction with Pt/C and simultaneously at both anode and cathode. A maximum power density of 68 mW/cm 2 is accomplished from the simultaneous use of Pd 3 Co/NG as both anode and cathode electrocatalyst with individual loading of 0.5 mg/cm 2 at 60 °C without any backpressure. To the best of our knowledge, the present study is the first of its kind of a fully non-Pt based PEM full cell.

  6. Effects of grain boundaries at the electrolyte/cathode interfaces on oxygen reduction reaction kinetics of solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Min Gi; Koo, Ja Yang; Ahn, Min Woo; Lee, Won Young [Dept. of Mechanical Engineering, Sungkyunkwan University, Suwon (Korea, Republic of)

    2017-04-15

    We systematically investigated the effects of grain boundaries (GBs) at the electrolyte/cathode interface of two conventional electrolyte materials, i.e., yttria-stabilized zirconia (YSZ) and gadolinia-doped ceria (GDC). We deposited additional layers by pulsed laser deposition to control the GB density on top of the polycrystalline substrates, obtaining significant improvements in peak power density (two-fold for YSZ and three-fold for GDC). The enhanced performance at high GB density in the additional layer could be ascribed to the accumulation of oxygen vacancies, which are known to be more active sites for oxygen reduction reactions (ORR) than grain cores. GDC exhibited a higher enhancement than YSZ, due to the easier formation, and thus higher concentration, of oxygen vacancies for ORR. The strong relation between the concentration of oxygen vacancies and the surface exchange characteristics substantiated the role of GBs at electrolyte/cathode interfaces on ORR kinetics, providing new design parameters for highly performing solid oxide fuel cells.

  7. Co-solvents with high coulombic efficiency in propylene carbonate based electrolytes

    Science.gov (United States)

    Liu, Gao; Zhao, Hui; Park, Sang-Jae

    2017-06-27

    A homologous series of cyclic carbonate or propylene carbonate (PC) analogue solvents with increasing length of linear alkyl substitutes were synthesized and used as co-solvents with PC for graphite based lithium ion half cells. A graphite anode reaches a capacity around 310 mAh/g in PC and its analogue co-solvents with 99.95% Coulombic efficiency. Cyclic carbonate co-solvents with longer alkyl chains are able to prevent exfoliation of graphite when used as co-solvents with PC. The cyclic carbonate co-solvents of PC compete for solvation of Li ion with PC solvent, delaying PC co-intercalation. Reduction products of PC on graphite surfaces via single-electron path form a stable Solid Electrolyte Interphase (SEI), which allows the reversible cycling of graphite.

  8. Recent progress in sulfide-based solid electrolytes for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D., E-mail: liu.dongqiang@ireq.ca; Zhu, W.; Feng, Z.; Guerfi, A.; Vijh, A.; Zaghib, K.

    2016-11-15

    Graphical abstract: Li{sub 2}S-GeS{sub 2}-P{sub 2}S{sub 5} ternary diagram showing various sulphide compounds as solid electrolytes for Li-ion batteries. - Highlights: • Recent progress of sulfide-based solid electrolytes is described from point of view of structure. • Thio-LISICON type electrolytes exhibited high ionic conductivity due to their bcc sublattice and unique Li{sup +} diffusion pathway. • “Mixed-anion effect” is also an effective way to modify the energy landscape as well as the ionic conductivity. - Abstract: Sulfide-based ionic conductors are one of most attractive solid electrolyte candidates for all-solid-state batteries. In this review, recent progress of sulfide-based solid electrolytes is described from point of view of structure. In particular, lithium thio-phosphates such as Li{sub 7}P{sub 3}S{sub 11}, Li{sub 10}GeP{sub 2}S{sub 12} and Li{sub 11}Si{sub 2}PS{sub 12} etc. exhibit extremely high ionic conductivity of over 10{sup −2} S cm{sup −1} at room temperature, even higher than those of commercial organic carbonate electrolytes. The relationship between structure and unprecedented high ionic conductivity is delineated; some potential drawbacks of these electrolytes are also outlined.

  9. Lithium batteries using poly(ethylene oxide)-based non-aqueous electrolytes

    Science.gov (United States)

    Chen, Zonghai; Amine, Khalil

    2015-09-08

    Lithium-air cells employing poly(ethyleneoxide) phosphate-based electrolytes may be prepared and exhibit improved charge carrying capacity. Such PEO phosphates generally have the formulas IIa, IIb, IIc, where: ##STR00001##

  10. Optofluidic interferometry chip designs of differential NIR absorbance based sensors for identification and quantification of electrolytes

    NARCIS (Netherlands)

    Steen, Gerrit W.; Wexler, Adam D.; Offerhaus, Herman L.

    2014-01-01

    Design and optimization of integrated photonic NIR absorbance based sensors for identification and quantification of aqueous electrolytes was performed by simulation in MATLAB and Optodesigner. Ten designs are presented and compared for suitability.

  11. Electrochromic devices employing methacrylate-based polymer electrolytes

    Czech Academy of Sciences Publication Activity Database

    Reiter, Jakub; Krejza, O.; Sedlaříková, M.

    2009-01-01

    Roč. 93, č. 2 (2009), s. 249-255 ISSN 0927-0248 R&D Projects: GA AV ČR KJB400320701; GA MŠk LC523 Institutional research plan: CEZ:AV0Z40320502 Keywords : polymer electrolyte * electrochromism * methacrylate Subject RIV: CA - Inorganic Chemistry Impact factor: 3.858, year: 2009

  12. Lithium ion conducting solid polymer blend electrolyte based on bio ...

    Indian Academy of Sciences (India)

    −4 Scm−1 has been observed for the composition of 70 PVA:30 PVP:25 Mwt% of LiNO3 with low activa- .... XRD pattern of (a) 70 PVA:30 PVP, (b) 70 PVA: .... charge carriers and also to the increase in the amorphous nature of the polymer electrolyte which reduces the energy barrier there by facilitating the ion trans- port.

  13. Mg/O2 Battery Based on the Magnesium-Aluminum Chloride Complex (MACC) Electrolyte

    DEFF Research Database (Denmark)

    Vardar, Galin; Smith, Jeffrey G.; Thomson, Travis

    2016-01-01

    Mg/O2 cells employing a MgCl2/AlCl3/DME (MACC/DME) electrolyte are cycled and compared to cells with modified Grignard electrolytes, showing that performance of magnesium/oxygen batteries depends strongly on electrolyte composition. Discharge capacity is far greater for MACC/DME-based cells, while...... substantially and likely explains the poor rechargeability. An additional impedance rise consistent with film formation on the Mg negative electrode suggests the presence of detrimental O2 crossover. Minimizing O2 crossover and bypassing charge transfer through the discharge product would improve battery...

  14. Electrospun PVdF-based fibrous polymer electrolytes for lithium ion polymer batteries

    International Nuclear Information System (INIS)

    Kim, Jeong Rae; Choi, Sung Won; Jo, Seong Mu; Lee, Wha Seop; Kim, Byung Chul

    2004-01-01

    This paper discusses the preparation of microporous fibrous membranes from PVdF solutions with different polymer contents, using the electrospinning technique. Electrospun PVdF-based fibrous membranes with average fiber diameters (AFD's) of 0.45-1.38 μm have an apparent porosity and a mean pore size (MPS) of 80-89% and 1.1-4.3 μm, respectively. They exhibited a high uptake of the electrolyte solution (320-350%) and a high ionic conductivity of above 1 x 10 -3 s/cm at room temperature. Their ionic conductivity increased with the decrease in the AFD of the fibrous membrane due to its high electrolyte uptake. The interaction between the electrolyte molecules and the PVdF with a high crystalline content may have had a minor effect on the lithium ion transfer in the fibrous polymer electrolyte, unlike in a nanoporous gel polymer electrolyte. The fibrous polymer electrolyte that contained a 1 M LiPF 6 -EC/DMC/DEC (1/1/1 by weight) solution showed a high electrochemical stability of above 5.0 V, which increased with the decrease in the AFD The interfacial resistance (R i ) between the polymer electrolyte and the lithium electrode slightly increased with the storage time, compared with the higher increase in the interfacial resistance of other gel polymer electrolytes. The prototype cell (MCMB/PVdF-based fibrous electrolyte/LiCoO 2 ) showed a very stable charge-discharge behavior with a slight capacity loss under constant current and voltage conditions at the C/2-rate of 20 and 60 deg. C

  15. Performance of flexible capacitors based on polypyrrole/carbon fiber electrochemically prepared from various phosphate electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Wei; Han, Gaoyi, E-mail: han_gaoyis@sxu.edu.cn; Chang, Yunzhen; Li, Miaoyu; Xiao, Yaoming, E-mail: ymxiao@sxu.edu.cn; Zhou, Haihan; Zhang, Ying; Li, Yanping

    2016-11-30

    Highlights: • PPy/CFs have been fabricated by electrodepositing polypyrrole on carbon fibers. • The electrolytes in deposition solution have effect on PPy/CFs’ capacitive behavior. • Cells of PPy/CFs obtained from NaH{sub 2}PO{sub 4} electrolyte has good stability in PVA/H{sub 3}PO{sub 4}. - Abstract: In order to investigate the influence of electrolytes in electro-deposition solution on the capacitive properties of polypyrrole (PPy), we have chosen phosphoric acid, phosphate, hydrogen phosphate and dihydrogen phosphate as electrolyte in deposition solution respectively and electrochemically deposited PPy on carbon fibers (CFs) via galvanostatic method. The morphologies of the PPy/CFs samples have been characterized by scanning electron microscope. The specific capacitance of PPy/CFs samples has been evaluated in different electrolytes through three-electrode test system. The assembled flexible capacitors by using PPy/CFs as electrodes and H{sub 3}PO{sub 4}/polyvinyl alcohol as gel electrolyte have been systematically measured by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results show that the electrochemical capacitors based on PPy/CFs prepared from deposition solution containing NaH{sub 2}PO{sub 4}·2H{sub 2}O electrolyte exhibit higher specific capacitance, flexibility and excellent stability (retaining 96.8% of initial capacitance after 13,000 cycles), and that three cells connected in series can power a light-emitting diode.

  16. Zinc-based electrolyte compositions, and related electrochemical processes and articles

    Energy Technology Data Exchange (ETDEWEB)

    Kniajanski, Sergei; Soloveichik, Grigorii Lev

    2018-02-20

    An aqueous electrolyte composition is described, including a zinc salt based on zinc acetate or zinc glocolate. The saturation concentration of zinc in the electrolyte composition is in the range of about 2.5M to about 3.5M. The composition also contains at least one salt of a monovalent cation. The molar ratio of zinc to the monovalent cation is about 1:2. An aqueous zinc electroplating bath, containing the aqueous electrolyte composition, is also disclosed, along with a method for the electrochemical deposition of zinc onto a substrate surface, using the electroplating bath. Related flow batteries are also described, including a catholyte, as well as an anolyte based on the aqueous electrolyte composition, with a membrane between the catholyte and the anolyte.

  17. Structural and Electrochemical Analysis of PMMA Based Gel Electrolyte Membranes

    Directory of Open Access Journals (Sweden)

    Chithra M. Mathew

    2015-01-01

    Full Text Available New gel polymer electrolytes containing poly(vinylidene chloride-co-acrylonitrile and poly(methyl methacrylate are prepared by solution casting method. With the addition of 60 wt.% of EC to PVdC-AN/PMMA blend, ionic conductivity value 0.398×10-6 S cm−1 has been achieved. XRD and FT-IR studies have been conducted to investigate the structure and complexation in the polymer gel electrolytes. The FT-IR spectra show that the functional groups C=O and C≡N play major role in ion conduction. Thermal stability of the prepared membranes is found to be about 180°C.

  18. Proton-conducting polymer electrolytes based on methacrylates

    Czech Academy of Sciences Publication Activity Database

    Reiter, Jakub; Velická, Jana; Míka, M.

    2008-01-01

    Roč. 53, č. 26 (2008), s. 7769-7774 ISSN 0013-4686 R&D Projects: GA ČR GA106/04/1279; GA AV ČR KJB400320701; GA MŠk LC523; GA ČR(CZ) GA104/06/1471 Institutional research plan: CEZ:AV0Z40320502 Keywords : polymer electrolyte * proton conductivity * phosporic acid Subject RIV: CA - Inorganic Chemistry Impact factor: 3.078, year: 2008

  19. Lanthanum germanate-based apatites as electrolyte for SOFCs

    Energy Technology Data Exchange (ETDEWEB)

    Marrero-Lopez, D.; Diaz-Carrasco, P.; Ramos-Barrado, J.R. [Departamento de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain); Pena-Martinez, J. [Instituto de Energias Renovables, Parque Tecnologico, Universidad de Castilla La Mancha, 02006 Albacete (Spain); Ruiz-Morales, J.C. [Departamento de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain)

    2011-02-15

    Germanate apatites with composition La{sub 10-x}Ge{sub 5.5}Al{sub 0.5}O{sub 26.75-3x/2} have been evaluated for the first time as possible electrolytes for solid oxide fuel cells (SOFCs). Different electrode materials have been considered in this study, i.e. manganite, ferrite, nickelates and cobaltite as cathode materials; and NiO-CGO composite and chromium-manganite as anodes. The chemical compatibility and electrochemical performance of these electrodes with La{sub 9.8}Ge{sub 5.5}Al{sub 0.5}O{sub 26.45} have been studied by X-ray powder diffraction (XRPD) and impedance spectroscopy. The XRPD analysis did not reveal appreciable bulk reactivity with the formation of reaction products between the germanate electrolyte and these electrodes up to 1,200 C. However, a significant cation interdiffusion was observed by energy dispersive spectroscopy (EDS) at the electrode/electrolyte interface, which leads to a significant decrease of the performance of these electrodes. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Direct Electrolytic Reduction of Solid Ta2O5 to Ta with SOM Process

    Science.gov (United States)

    Chen, Chaoyi; Yang, Xiaqiong; Li, Junqi; Lu, Xionggang; Yang, Shufeng

    2016-06-01

    A process that uses the solid-oxide-oxygen-ion conducting membrane has been investigated to produce tantalum directly from solid Ta2O5 in molten CaCl2 or a molten mixture of 55.5MgF2-44.5CaF2 (in wt pct). The sintered porous Ta2O5 pellet was employed as the cathode, while the liquid copper alloy, saturated with graphite powder and encased in a one-end-closed yttria-stabilized-zirconia (YSZ) tube, acted as the anode. The electrolysis potential in this method is higher than that of the Fray-Farthing-Chen Cambridge process because the YSZ membrane tube blocks the melts to electrolyze, and only Ta2O5 is will be electrolyzed. The microstructures of reduced pellets and a cyclic voltammogram of solid Ta2O5 in molten CaCl2 were analyzed. In addition, the influence of particle size and porosity of the cathode pellets on metal-oxide-electrolyte, three-phase interlines was also discussed. The results demonstrate that the sintering temperature of cathode pellets and electrolytic temperature play important roles in the electrochemical process. Furthermore, this process can be used to produce Ta metal efficiently without the expensive cost of pre-electrolysis and generation of harmful by-products.

  1. A Synopsis of Interfacial Phenomena in Lithium-Based Polymer Electrolyte Electrochemical Cells

    Science.gov (United States)

    Baldwin, Richard S.; Bennett, William R.

    2007-01-01

    The interfacial regions between electrode materials, electrolytes and other cell components play key roles in the overall performance of lithium-based batteries. For cell chemistries employing lithium metal, lithium alloy or carbonaceous materials (i.e., lithium-ion cells) as anode materials, a "solid electrolyte interphase" (SEI) layer forms at the anode/electrolyte interface, and the properties of this "passivating" layer significantly affect the practical cell/battery quality and performance. A thin, ionically-conducting SEI on the electrode surface can beneficially reduce or eliminate undesirable side reactions between the electrode and the electrolyte, which can result in a degradation in cell performance. The properties and phenomena attributable to the interfacial regions existing at both anode and cathode surfaces can be characterized to a large extent by electrochemical impedance spectroscopy (EIS) and related techniques. The intention of the review herewith is to support the future development of lithium-based polymer electrolytes by providing a synopsis of interfacial phenomena that is associated with cell chemistries employing either lithium metal or carbonaceous "composite" electrode structures which are interfaced with polymer electrolytes (i.e., "solvent-free" as well as "plasticized" polymer-binary salt complexes and single ion-conducting polyelectrolytes). Potential approaches to overcoming poor cell performance attributable to interfacial effects are discussed.

  2. Charge transfer mediator based systems for electrocatalytic oxygen reduction

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, Shannon S.; Gerken, James B.; Anson, Colin W.

    2017-11-07

    Disclosed are systems for the electrocatalytic reduction of oxygen, having redox mediator/redox catalyst pairs and an electrolyte solution in contact with an electrode. The redox mediator is included in the electrolyte solution, and the redox catalyst may be included in the electrolyte solution, or alternatively, may be in contact with the electrolyte solution. In one form a cobalt redox catalyst is used with a quinone redox mediator. In another form a nitrogen oxide redox catalyst is used with a nitroxyl type redox mediator. The systems can be used in electrochemical cells wherein neither the anode nor the cathode comprise an expensive metal such as platinum.

  3. Charge transfer mediator based systems for electrocatalytic oxygen reduction

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, Shannon S.; Gerken, James B.; Anson, Colin W.

    2017-07-18

    Disclosed are systems for the electrocatalytic reduction of oxygen, having redox mediator/redox catalyst pairs and an electrolyte solution in contact with an electrode. The redox mediator is included in the electrolyte solution, and the redox catalyst may be included in the electrolyte solution, or alternatively, may be in contact with the electrolyte solution. In one form a cobalt redox catalyst is used with a quinone redox mediator. In another form a nitrogen oxide redox catalyst is used with a nitroxyl type redox mediator. The systems can be used in electrochemical cells wherein neither the anode nor the cathode comprise an expensive metal such as platinum.

  4. Poly(oxyethylene) electrolytes based on lithium pentafluorobenzene sulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Paillard, E.; Iojoiu, C.; Alloin, F.; Guindet, J.; Sanchez, J.-Y. [LEPMI, Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, UMR 5631 CNRS-INPG-UJF, BP 75, 38402 Saint-Martin-d' Heres Cedex (France)

    2007-03-01

    Lithium pentafluorobenzene sulfonate was synthesized by a protocol whereby pollution by aromatic nucleophilic substitutions on the perfluorinated ring was avoided. Its poly(oxyethylene) complexes, although less conductive than lithium imide complexes, provided cationic transference numbers higher than 0.5. Surprisingly, even at fairly low concentrations, this salt markedly increased the mechanical properties of the polymer electrolyte. This effect was attributed to telechelic interactions of the ion pairs with distinct polyether chains and is in agreement with the high cationic transference numbers. (author)

  5. DNA Based Electrolyte/Separator for Lithium Battery Application (Postprint)

    Science.gov (United States)

    2015-10-07

    The ‘cap’ was placed over the ‘can’ and the film was left to absorb the liquid electrolyte for few hours. After 2 hours, a stainless steel disk... FTIR ) data was collected using a Thermo Scientific Nicolet 6700 to determine the physical/chemical interaction between the PVDF, DNA and liquid...LiAsF6 3.3. FTIR Both DNA and PVDF show their characteristic FTIR peaks (Fig. 5): DNA doping by CTMA ion at 2926 and 2846 cm-1, C=O stretching at

  6. Highly dispersed TaOx nanoparticles prepared by electrodeposition as oxygen reduction electrocatalysts for polymer electrolyte fuel cells

    KAUST Repository

    Seo, Jeongsuk

    2013-06-06

    Based on the chemical stability of group IV and V elements in acidic solutions, TaOx nanoparticles prepared by electrodeposition in an ethanol-based Ta plating bath at room temperature were investigated as novel nonplatinum electrocatalysts for the oxygen reduction reaction (ORR) in polymer electrolyte fuel cells (PEFCs). Electrodeposition conditions of Ta complexes and subsequent various heat treatments for the deposited TaOx were examined for the best performance of the ORR. TaOx particles on carbon black (CB), electrodeposited at a constant potential of -0.5 V Ag/AgCl for 10 s and then heat-treated by pure H2 flow at 523 K for 1 h, showed excellent catalytic activity with an onset potential of 0.93 VRHE (for 2 μA cm-2) for the ORR. Surface characterizations of the catalysts were performed by scanning transmission electron microscopy (STEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). The loading amounts of the electrodeposited material on the CB were determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES). All the physical results suggested that high dispersion of TaOx particles on the CB surface with 2-3 nm size was critical and key for high activity. The chemical identity and modified surface structure for the deposited TaOx catalysts before and after H 2 heat treatment were analyzed by X-ray photoelectron spectroscopy (XPS). The formation of more exposed active sites on the electrode surface and enhanced electroconductivity of the tantalum oxide promoted from the H 2 treatment greatly improved the ORR performance of the electrodeposited TaOx nanoparticles on CB. Finally, the highly retained ORR activity after an accelerated durability test in an acidic solution confirmed and proved the chemical stability of the oxide nanoparticles. The high utilization of the electrodeposited TaOx nanoparticles uniformly dispersed on CB for the ORR was comparable to that of commercial Pt/CB catalysts

  7. Dextran based highly conductive hydrogel polysulfide electrolyte for efficient quasi-solid-state quantum dot-sensitized solar cells

    International Nuclear Information System (INIS)

    Chen, Hong-Yan; Lin, Ling; Yu, Xiao-Yun; Qiu, Kang-Qiang; Lü, Xian-Yong; Kuang, Dai-Bin; Su, Cheng-Yong

    2013-01-01

    Highlights: ► Dextran based hydrogel is first used to prepare quasi-solid-state polysulfide electrolyte for quantum dot-sensitized solar cells. ► The ion conductivity of hydrogel electrolyte shows almost the same value as the liquid electrolyte. ► The liquid state at elevated temperature of hydrogel electrolyte allows for a good contact between electrolyte and CdS/CdSe co-sensitized TiO 2 photoanode. ► The hydrogel electrolyte based cell exhibits slightly lower power conversion efficiency than that of liquid electrolyte based cell. ► The dynamic electron transfer mechanism in hydrogel electrolyte based cell is examined in detail by EIS and CIMPS/IMVS. -- Abstract: Highly conductive hydrogel polysulfide electrolyte is first fabricated using dextran as gelator and used as quasi-solid-state electrolyte for quantum dot-sensitized solar cells (QDSSCs). The hydrogel electrolyte with gelator concentration of 15 wt% shows almost the same conductivity as the liquid one. Moreover, its liquid state at elevated temperature allow for the well penetration into the pores in electrodeposited CdS/CdSe co-sensitized TiO 2 photoanode. This gel electrolyte based QDSSC exhibits power conversion efficiency (η) of 3.23% under AG 1.5 G one sun (100 mW cm −2 ) illumination, slightly lower than that of liquid electrolyte based cell (3.69%). The dynamic electron transfer mechanism of the gel and liquid electrolyte based QDSSC are examined by electrochemical impedance spectroscopy (EIS) and controlled intensity modulated photocurrent/photovoltage spectroscopy (CIMPS/IMVS). It is found that the electron transport in gel electrolyte based cell is much faster than the liquid electrolyte based cell but it tends to recombine more easily than the latter. However, these differences fade away with increasing the light intensity, showing declining electron collection efficiency at higher light intensity illumination. As a result, a conversion efficiency of 4.58% is obtained for the gel

  8. Synthesis of a novel imidazolium-based electrolytes and application for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Dong-Wan [Department of Applied Chemistry, Konkuk University, 322 Danwol-dong, 380-701 Chungju (Korea, Republic of); Sarker, Subrata; Nath, Narayan Chandra Deb [Department of Advanced Technology Fusion, Konkuk University, Seoul (Korea, Republic of); Choi, Seung-Woo [Department of Applied Chemistry, Konkuk University, 322 Danwol-dong, 380-701 Chungju (Korea, Republic of); Ahammad, A.J. Saleh [Department of Advanced Technology Fusion, Konkuk University, Seoul (Korea, Republic of); Lee, Jae-Joon, E-mail: jjlee@kku.ac.k [Department of Applied Chemistry, Konkuk University, 322 Danwol-dong, 380-701 Chungju (Korea, Republic of); Department of Advanced Technology Fusion, Konkuk University, Seoul (Korea, Republic of); Kim, Whan-Gi, E-mail: wgkim@kku.ac.k [Department of Applied Chemistry, Konkuk University, 322 Danwol-dong, 380-701 Chungju (Korea, Republic of)

    2010-01-25

    A series of new imidazolium-based oligomers with different length of a poly(ethylene glycol) moiety as a linker were synthesized and studied as electrolytes for dye-sensitized solar cell (DSSC). These oligomeric molecules are expected to have an intra- or inter-molecular hydrogen bonding interaction through its urethane and urea bonds. They can be used to prepare the liquid-type electrolytes for DSSC by dissolving them into conventional solvent system or to develop solvent-free electrolytes by incorporating an extra redox mediator and other functional materials together as additives. It was found that these oligomers could replace the cationic component of the conventional electrolytes and became the source of redox species when iodine is added. The photocurrent-voltage characteristics of DSSCs with the electrolytes containing these oligomers demonstrated that they can successfully replace the conventional ionic liquid-type electrolytes such as 1-methyl-3-propyl imidazolium iodide (PMII) in 3-methoxypropionitrile (MPN) if the length of the linker is optimized.

  9. Synthesis of a novel imidazolium-based electrolytes and application for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Seo, Dong-Wan; Sarker, Subrata; Nath, Narayan Chandra Deb; Choi, Seung-Woo; Ahammad, A.J. Saleh; Lee, Jae-Joon; Kim, Whan-Gi

    2010-01-01

    A series of new imidazolium-based oligomers with different length of a poly(ethylene glycol) moiety as a linker were synthesized and studied as electrolytes for dye-sensitized solar cell (DSSC). These oligomeric molecules are expected to have an intra- or inter-molecular hydrogen bonding interaction through its urethane and urea bonds. They can be used to prepare the liquid-type electrolytes for DSSC by dissolving them into conventional solvent system or to develop solvent-free electrolytes by incorporating an extra redox mediator and other functional materials together as additives. It was found that these oligomers could replace the cationic component of the conventional electrolytes and became the source of redox species when iodine is added. The photocurrent-voltage characteristics of DSSCs with the electrolytes containing these oligomers demonstrated that they can successfully replace the conventional ionic liquid-type electrolytes such as 1-methyl-3-propyl imidazolium iodide (PMII) in 3-methoxypropionitrile (MPN) if the length of the linker is optimized.

  10. Investigation of cadmium(2) electrolytic reduction kinetics from α-aminoacetic solutions

    International Nuclear Information System (INIS)

    Nikitenko, V.N.; Litovchenko, K.I.; Kublanovskij, V.S.

    1980-01-01

    Kinetics and reduction mechanism of cadmium(2) reduction from α-amino acetic solutions is studied. It is shown that glycine and hydrogen ions take part directly in the electrode reaction of cadmium (2) reduction from α-amino acetic solutions. It is established that complex ion of the composition CdCl + is electroactive forM of the substance, which takes part in the transfer reaction. The rate of electrode process is limited with reduced ion supply to the electrode surface

  11. Liquid electrolytes based on new lithium conductive imidazole salts

    Energy Technology Data Exchange (ETDEWEB)

    Niedzicki, L.; Kasprzyk, M.; Kuziak, K.; Zukowska, G.Z.; Marcinek, M.; Wieczorek, W. [Department of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Armand, M. [LRCS, University de Picardie Jules Verne, UMR 6007 CNRS, 33 rue de Saint-Leu, 80039 Amiens (France)

    2011-02-01

    In the present paper new generation of imidazole-derived lithium salts (LiTDI - lithium 4,5-dicyano-2-(trifluoromethyl)imidazolide, LiPDI - lithium 4,5-dicyano-2-(pentafluoroethyl)imidazolide and LiHDI - lithium 4,5-dicyano-2-(n-heptafluoropropyl)imidazolide) applied in a model liquid electrolyte, with propylene carbonate used as a solvent, is described. Room temperature ionic conductivities measured by Impedance Spectroscopy are as high as 10{sup -2} to 10{sup -3} S cm{sup -1} for the 0.1-1 mol dm{sup -3} salt concentration range. Lithium cation transference numbers calculated using the Bruce-Vincent method exceed 0.4 at salt concentration equal to 1 mol dm{sup -3}. Interface resistance measurements showed good stability at high - 0.5 mol dm{sup -3} or low - 0.01 mol dm{sup -3} salt concentrations. Ionic associations were estimated using Fuoss-Kraus semiempirical method revealing relatively low association rates. The effect of anion structure on ionic interactions and electrochemical characteristics of the studied electrolytes is discussed. (author)

  12. Label-free detection of DNA using novel organic-based electrolyte-insulator-semiconductor.

    Science.gov (United States)

    Lin, Tsung-Wu; Kekuda, Dhananjay; Chu, Chih-Wei

    2010-08-15

    In this study, we have constructed the first organic field effect sensor based on an electrolyte-insulator-semiconductor structure (OEIS) and applied this novel device to pH and DNA sensing. Variations in the insulator-electrolyte surface potential, which originate from either the change of the ionization states of the insulator surface groups or the binding of charged molecules to the insulator surface, modify the flat band voltage (V(FB)) of the OEIS sensor. The pH sensing experiments of OEIS sensor showed that the output signal linearly depended on pH solution in the range from pH 2 to pH 12, and an average sensitivity of 44.1 mV/pH was obtained. In the biosensing experiments, the absorption of positively charged poly-L-lysine on the insulator surface resulted in the reduction of the V(FB) value, whereas the subsequent binding of negatively charged single-stranded DNA probe (ssDNA) via electrostatic interaction increased the V(FB) value. Furthermore, the ssDNA-immobilized OEIS device was successfully used for the detection of DNA hybridization. The detection limit of complementary DNA was as low as 1 microM, and the output signal of OEIS biosensor linearly increased with the logarithm of complementary DNA concentration in the range from 5x10(-5) to 10(-7) M. The easy and inexpensive fabrication of the OEIS device allows to be served as a potentially disposable and sensitive biosensor. Copyright 2010 Elsevier B.V. All rights reserved.

  13. Sequential separation of transuranic elements and fission products from uranium metal ingots in electrolytic reduction process of spent PWR fuels

    International Nuclear Information System (INIS)

    Chang Heon Lee; Kih Soo Joe; Won Ho Kim; Euo Chang Jung; Kwang Yong Jee

    2009-01-01

    A sequential separation procedure has been developed for the determination of transuranic elements and fission products in uranium metal ingot samples from an electrolytic reduction process for a metallization of uranium dioxide to uranium metal in a medium of LiCl-Li 2 O molten salt at 650 deg C. Pu, Np and U were separated using anion-exchange and tri-n-butylphosphate (TBP) extraction chromatography. Cs, Sr, Ba, Ce, Pr, Nd, Sm, Eu, Gd, Zr and Mo were separated in several groups from Am and Cm using TBP and di(2-ethylhexyl)phosphoric acid (HDEHP) extraction chromatography. Effect of Fe, Ni, Cr and Mg, which were corrosion products formed through the process, on the separation of the analytes was investigated in detail. The validity of the separation procedure was evaluated by measuring the recovery of the stable metals and 239 Pu, 237 Np, 241 Am and 244 Cm added to a synthetic uranium metal ingot dissolved solution. (author)

  14. Kinetics of sodium borohydride direct oxidation and oxygen reduction in sodium hydroxide electrolyte - Part II. O-2 reduction

    Czech Academy of Sciences Publication Activity Database

    Chatenet, M.; Micoud, F.; Roche, I.; Chainet, E.; Vondrák, Jiří

    2006-01-01

    Roč. 51, č. 25 (2006), s. 5452-5458 ISSN 0013-4686 Institutional research plan: CEZ:AV0Z40320502 Keywords : oxygen reduction reaction selectivity * platinum * silver Subject RIV: CA - Inorganic Chemistry Impact factor: 2.955, year: 2006

  15. Water oxidation by amorphous cobalt-based oxides: volume activity and proton transfer to electrolyte bases.

    Science.gov (United States)

    Klingan, Katharina; Ringleb, Franziska; Zaharieva, Ivelina; Heidkamp, Jonathan; Chernev, Petko; Gonzalez-Flores, Diego; Risch, Marcel; Fischer, Anna; Dau, Holger

    2014-05-01

    Water oxidation in the neutral pH regime catalyzed by amorphous transition-metal oxides is of high interest in energy science. Crucial determinants of electrocatalytic activity were investigated for a cobalt-based oxide film electrodeposited at various thicknesses on inert electrodes. For water oxidation at low current densities, the turnover frequency (TOF) per cobalt ion of the bulk material stayed fully constant for variation of the thickness of the oxide film by a factor of 100 (from about 15 nm to 1.5 μm). Thickness variation changed neither the nanostructure of the outer film surface nor the atomic structure of the oxide catalyst significantly. These findings imply catalytic activity of the bulk hydrated oxide material. Nonclassical dependence on pH was observed. For buffered electrolytes with pKa values of the buffer base ranging from 4.7 (acetate) to 10.3 (hydrogen carbonate), the catalytic activity reflected the protonation state of the buffer base in the electrolyte solution directly and not the intrinsic catalytic properties of the oxide itself. It is proposed that catalysis of water oxidation occurs within the bulk hydrated oxide film at the margins of cobalt oxide fragments of molecular dimensions. At high current densities, the availability of a proton-accepting base at the catalyst-electrolyte interface controls the rate of water oxidation. The reported findings may be of general relevance for water oxidation catalyzed at moderate pH by amorphous transition-metal oxides. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Enabling bis(fluorosulfonyl)imide-based ionic liquid electrolytes for application in dual-ion batteries

    Science.gov (United States)

    Beltrop, Kolja; Qi, Xin; Hering, Tobias; Röser, Stephan; Winter, Martin; Placke, Tobias

    2018-01-01

    In this work, we present a comprehensive study on the effect of adding different conductive salt additives including LiPF6, LiBF4 and LiDFOB, as well as the fluorinated solvent additive methyl difluoroacetate (MDFA) to a bis(fluorosulfonyl)imide (FSI)-based ionic liquid (IL) electrolyte, i.e. Pyr14FSI/LiFSI, to protect the Al current collector (ACC) from anodic dissolution and, thus, enable reversible charge/discharge cycling in a high performance dual-ion cell. Chronocoulometry and scanning electron microscopy measurements were conducted to evaluate the specific ACC passivation ability of each electrolyte. Furthermore, the influence of these additives on anion intercalation behavior into the graphite positive electrode with special emphasis on the Coulombic efficiency (CE), reversible capacity, as well as capacity retention is presented. Overall, we can show that the addition of small amounts of LiPF6, LiBF4 and MDFA (0.5 wt%) into the FSI-based IL electrolyte significantly increases the overall cell performance, whereas LiDFOB as electrolyte additive deteriorates the dual-ion cell performance. In addition, an excellent cycling performance for 1000 cycles is obtained for the Pyr14FSI electrolyte having 5 wt% LiPF6, displaying an average reversible capacity of 40 mAh g-1, a CE exceeding 98% and a capacity retention of 91%, which has not been reported so far.

  17. Electrochemical properties of ether-based electrolytes for lithium/sulfur rechargeable batteries

    International Nuclear Information System (INIS)

    Barchasz, Céline; Leprêtre, Jean-Claude; Patoux, Sébastien; Alloin, Fannie

    2013-01-01

    Highlights: ► Liquid electrolyte composition for lithium/sulfur secondary batteries. ► Carbonate-based electrolytes prove not to be compatible with the sulfur electrode. ► Poor electrochemical performances related to low polysulfide solubility. ► Increase in the discharge capacity using ether solvents with high solvating ability such as PEGDME. ► Evidence of DIOX polymerization during cycling. -- Abstract: The lithium/sulfur (Li/S) battery is a promising electrochemical system that has a high theoretical capacity of 1675 mAh g −1 . However, the system suffers from several drawbacks: poor active material conductivity, active material dissolution, and use of the highly reactive lithium metal electrode. In this study, we investigated the electrolyte effects on electrochemical performances of the Li/S cell, by acting on the solvent composition. As conventional carbonate-based electrolytes turned out to be unusable in Li/S cells, alternative ether solvents had to be considered. Different kinds of solvent structures were investigated by changing the ether/alkyl moieties ratio to vary the lithium polysulfide solubility. This allowed to point out the importance of the solvent solvation ability on the discharge capacity. As the end of discharge is linked to the positive electrode passivation, an electrolyte having high solvation ability reduces the polysulfide precipitation and delays the positive electrode passivation

  18. Electrospun hydrophilic fumed silica/polyacrylonitrile nanofiber-based composite electrolyte membranes

    International Nuclear Information System (INIS)

    Jung, Hong-Ryun; Ju, Dong-Hyuk; Lee, Wan-Jin; Zhang, Xiangwu; Kotek, Richard

    2009-01-01

    Hydrophilic fumed silica (SiO 2 )/polyacrylonitrile (PAN) composite electrolyte membranes were prepared by electrospinning composite solutions of SiO 2 and PAN in N,N-dimethylformamide (DMF). Among electrospinning solutions with various SiO 2 contents, the 12 wt% SiO 2 in PAN solution has highest zeta potential (-40.82 mV), and exhibits the best dispersibility of SiO 2 particles. The resultant 12 wt% SiO 2 /PAN nanofiber membrane has the smallest average fiber diameter, highest porosity, and largest specific surface area. In addition, this membrane has a three-dimensional network structure, which is fully interconnected with combined mesopores and macropores because of a good SiO 2 dispersion. Composite electrolyte membranes were prepared by soaking these porous nanofiber membranes in 1 M lithium hexafluorophosphate (LiPF 6 ) in ethylene carbonate (EC)/dimethyl carbonate (DMC) (1:1 vol%). It is found that 12 wt% SiO 2 /PAN electrolyte membrane has the highest conductivity (1.1 x 10 -2 S cm -1 ) due to the large liquid electrolyte uptake (about 490%). In addition, the electrochemical performance of composite electrolyte membranes is also improved after the introduction of SiO 2 . For initial cycle, 12 wt% SiO 2 /PAN composite electrolyte membrane delivers the discharge capacity of 139 mAh g -1 as 98% of theoretical value, and still retains a high value of 127 mAh g -1 as 89% at 150th cycle, which is significantly higher that of pure PAN nanofiber-based electrolyte membranes.

  19. Hardness analysis and morphological characterization of copper-zinc alloys produced in pyrophosphate-based electrolytes

    Directory of Open Access Journals (Sweden)

    Lilian Ferreira de Senna

    2005-09-01

    Full Text Available In this work, copper-zinc alloy coatings on mild steel substrates were obtained in nontoxic pyrophosphate-based electrolytes, at room temperature and under continuous current. The effects of bath composition and current density on the hardness of the coatings, as well as on their morphologies, were evaluated. The results showed that the electrolyte composition, and the use of stress relieving additives strongly influence the hardness of the coatings, while the current density directly affect their morphology. Hence, for a current density of 116 A/m², copper-zinc alloy deposits with no pores or cracks were produced in a pyrophosphate-based electrolyte, especially when allyl alcohol was added to the solution.

  20. X-ray photoemission spectroscopy analysis of N-containing carbon-based cathode catalysts for polymer electrolyte fuel cells

    Science.gov (United States)

    Niwa, Hideharu; Kobayashi, Masaki; Horiba, Koji; Harada, Yoshihisa; Oshima, Masaharu; Terakura, Kiyoyuki; Ikeda, Takashi; Koshigoe, Yuka; Ozaki, Jun-ichi; Miyata, Seizo; Ueda, Shigenori; Yamashita, Yoshiyuki; Yoshikawa, Hideki; Kobayashi, Keisuke

    We report on the electronic structure of three different types of N-containing carbon-based cathode catalysts for polymer electrolyte fuel cells observed by hard X-ray photoemission spectroscopy. Prepared samples are derived from: (1) melamine and poly(furfuryl alcohol), (2) nitrogen-doped carbon black and (3) cobalt phthalocyanine and phenolic resin. C 1 s spectra show the importance of sp 2 carbon network formation for the oxygen reduction reaction (ORR) activity. N 1 s spectra of the carbon-based cathode catalysts are decomposed into four components identified as pyridine-like, pyrrole- or cyanide-like, graphite-like, and oxide nitrogen. Samples having high oxygen reduction reaction activity in terms of oxygen reduction potential contain high concentration of graphite-like nitrogen. O 1 s spectra are similar among carbon-based cathode catalysts of different oxygen reduction reaction activity. There is no correlation between the ORR activity and oxygen content. Based on a quantitative analysis of our results, the oxygen reduction reaction activity of the carbon-based cathode catalysts will be improved by increasing concentration of graphite-like nitrogen in a developed sp 2 carbon network.

  1. A Catalytic Path for Electrolyte Reduction in Lithium-Ion Cells Revealed by in Situ Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy

    KAUST Repository

    Shi, Feifei

    2015-03-11

    © 2015 American Chemical Society. Although controlling the interfacial chemistry of electrodes in Li-ion batteries (LIBs) is crucial for maintaining the reversibility, electrolyte decomposition has not been fully understood. In this study, electrolyte decomposition on model electrode surfaces (Au and Sn) was investigated by in situ attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. Simultaneously obtained ATR-FTIR spectra and cyclic voltammetry measurements show that lithium ethylene dicarbonate and lithium propionate form on the Au electrode at 0.6 V, whereas diethyl 2,5-dioxahexane dicarboxylate and lithium propionate form on the Sn electrode surface at 1.25 V. A noncatalytic reduction path on the Au surface and a catalytic reduction path on the Sn surface are introduced to explain the surface dependence of the overpotential and product selectivity. This represents a new concept for explaining electrolyte reactions on the anode of LIBs. The present investigation shows that catalysis plays a dominant role in the electrolyte decomposition process and has important implications in electrode surface modification and electrolyte recipe selection, which are critical factors for enhancing the efficiency, durability, and reliability of LIBs.

  2. Performance of flexible capacitors based on polypyrrole/carbon fiber electrochemically prepared from various phosphate electrolytes

    Science.gov (United States)

    Yuan, Wei; Han, Gaoyi; Chang, Yunzhen; Li, Miaoyu; Xiao, Yaoming; Zhou, Haihan; Zhang, Ying; Li, Yanping

    2016-11-01

    In order to investigate the influence of electrolytes in electro-deposition solution on the capacitive properties of polypyrrole (PPy), we have chosen phosphoric acid, phosphate, hydrogen phosphate and dihydrogen phosphate as electrolyte in deposition solution respectively and electrochemically deposited PPy on carbon fibers (CFs) via galvanostatic method. The morphologies of the PPy/CFs samples have been characterized by scanning electron microscope. The specific capacitance of PPy/CFs samples has been evaluated in different electrolytes through three-electrode test system. The assembled flexible capacitors by using PPy/CFs as electrodes and H3PO4/polyvinyl alcohol as gel electrolyte have been systematically measured by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results show that the electrochemical capacitors based on PPy/CFs prepared from deposition solution containing NaH2PO4·2H2O electrolyte exhibit higher specific capacitance, flexibility and excellent stability (retaining 96.8% of initial capacitance after 13,000 cycles), and that three cells connected in series can power a light-emitting diode.

  3. Gel polymer electrolytes based on nanofibrous polyacrylonitrile–acrylate for lithium batteries

    International Nuclear Information System (INIS)

    Kim, Dul-Sun; Woo, Jang Chang; Youk, Ji Ho; Manuel, James; Ahn, Jou-Hyeon

    2014-01-01

    Graphical abstract: - Highlights: • Nanofibrous polyacrylonitrile–acrylate membranes were prepared by electrospinning. • Trimethylolpropane triacrylate was used as a crosslinking agent of fibers. • The GPE based on PAN–acrylate (1/0.5) showed good electrochemical properties. - Abstract: Nanofibrous membranes for gel polymer electrolytes (GPEs) were prepared by electrospinning a mixture of polyacrylonitrile (PAN) and trimethylolpropane triacrylate (TMPTA) at weight ratios of 1/0.5 and 1/1. TMPTA is used to achieve crosslinking of fibers thereby improving mechanical strength. The average fiber diameters increased with increasing TMPTA concentration and the mechanical strength was also improved due to the enhanced crosslinking of fibers. GPEs based on electrospun membranes were prepared by soaking them in a liquid electrolyte of 1 M LiPF 6 in ethylene carbonate (EC)/dimethyl carbonate (DMC) (1:1, v/v). The electrolyte uptake and ionic conductivity of GPEs based on PAN and PAN–acrylate (weight ratio; 1/1 and 1/0.5) were investigated. Ionic conductivity of GPEs based on PAN–acrylate was the highest for PAN/acrylate (1/0.5) due to the proper swelling of fibers and good affinity with liquid electrolyte. Both GPEs based on PAN and PAN–acrylate membranes show good oxidation stability, >5.0 V vs. Li/Li + . Cells with GPEs based on PAN–acrylate (1/0.5) showed remarkable cycle performance with high initial discharge capacity and low capacity fading

  4. Gel polymer electrolytes based on nanofibrous polyacrylonitrile–acrylate for lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dul-Sun [Department of Chemical and Biological Engineering, Research Institute for Green Energy Convergence Technology, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of); Woo, Jang Chang [Department of Textile Engineering, Inha University, 100 Inharo, Nam-gu Incheon 402-751 (Korea, Republic of); Youk, Ji Ho, E-mail: youk@inha.ac.kr [Department of Textile Engineering, Inha University, 100 Inharo, Nam-gu Incheon 402-751 (Korea, Republic of); Manuel, James [Department of Chemical and Biological Engineering, Research Institute for Green Energy Convergence Technology, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of); Ahn, Jou-Hyeon, E-mail: jhahn@gnu.ac.kr [Department of Chemical and Biological Engineering, Research Institute for Green Energy Convergence Technology, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of); Department of Materials Engineering and Convergence Technology, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of)

    2014-10-15

    Graphical abstract: - Highlights: • Nanofibrous polyacrylonitrile–acrylate membranes were prepared by electrospinning. • Trimethylolpropane triacrylate was used as a crosslinking agent of fibers. • The GPE based on PAN–acrylate (1/0.5) showed good electrochemical properties. - Abstract: Nanofibrous membranes for gel polymer electrolytes (GPEs) were prepared by electrospinning a mixture of polyacrylonitrile (PAN) and trimethylolpropane triacrylate (TMPTA) at weight ratios of 1/0.5 and 1/1. TMPTA is used to achieve crosslinking of fibers thereby improving mechanical strength. The average fiber diameters increased with increasing TMPTA concentration and the mechanical strength was also improved due to the enhanced crosslinking of fibers. GPEs based on electrospun membranes were prepared by soaking them in a liquid electrolyte of 1 M LiPF{sub 6} in ethylene carbonate (EC)/dimethyl carbonate (DMC) (1:1, v/v). The electrolyte uptake and ionic conductivity of GPEs based on PAN and PAN–acrylate (weight ratio; 1/1 and 1/0.5) were investigated. Ionic conductivity of GPEs based on PAN–acrylate was the highest for PAN/acrylate (1/0.5) due to the proper swelling of fibers and good affinity with liquid electrolyte. Both GPEs based on PAN and PAN–acrylate membranes show good oxidation stability, >5.0 V vs. Li/Li{sup +}. Cells with GPEs based on PAN–acrylate (1/0.5) showed remarkable cycle performance with high initial discharge capacity and low capacity fading.

  5. Zirconium oxide based ceramic solid electrolytes for oxygen detection

    International Nuclear Information System (INIS)

    Caproni, Erica

    2007-01-01

    Taking advantage of the high thermal shock resistance of zirconia-magnesia ceramics and the high oxide ion conductivity of zirconia-yttria ceramics, composites of these ceramics were prepared by mixing, pressing and sintering different relative concentrations of ZrO 2 : 8.6 mol% MgO and ZrO 2 : 3 mol% Y 2 O 3 solid electrolytes. Microstructural analysis of the composites was carried out by X-ray diffraction and scanning electron microscopy analyses. The thermal behavior was studied by dilatometric analysis. The electrical behavior was evaluated by the impedance spectroscopy technique. An experimental setup was designed for measurement the electrical signal generated as a function of the amount of oxygen at high temperatures. The main results show that these composites are partially stabilized (monoclinic, cubic and tetragonal) and the thermal behavior is similar to that of ZrO 2 : 8.6 mol% MgO materials used in disposable high temperature oxygen sensors. Moreover, the results of analysis of impedance spectroscopy show that the electrical conductivity of zirconia:magnesia is improved with zirconia-yttria addition and that the electrical signal depends on the amount of oxygen at 1000 deg C, showing that the ceramic composites can be used in oxygen sensors. (author)

  6. Impedance studies of a green blend polymer electrolyte based on PVA and Aloe-vera

    Science.gov (United States)

    Selvalakshmi, S.; Mathavan, T.; Vijaya, N.; Selvasekarapandian, Premalatha, M.; Monisha, S.

    2016-05-01

    The development of polymer electrolyte materials for energy generating and energy storage devices is a challenge today. A new type of blended green electrolyte based on Poly-vinyl alcohol (PVA) and Aloe-vera has been prepared by solution casting technique. The blending of polymers may lead to the increase in stability due to one polymer portraying itself as a mechanical stiffener and the other as a gelled matrix supported by the other. The prepared blend electrolytes were subjected to Ac impedance studies. It has been found out that the polymer film in which 1 gm of PVA was dissolved in 40 ml of Aloe-vera extract exhibits highest conductivity and its value is 3.08 × 10-4 S cm-1.

  7. Synthesis and Characterization of Cellulose-Based Hydrogels to Be Used as Gel Electrolytes

    Directory of Open Access Journals (Sweden)

    Maria Assunta Navarra

    2015-11-01

    Full Text Available Cellulose-based hydrogels, obtained by tuned, low-cost synthetic routes, are proposed as convenient gel electrolyte membranes. Hydrogels have been prepared from different types of cellulose by optimized solubilization and crosslinking steps. The obtained gel membranes have been characterized by infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mechanical tests in order to investigate the crosslinking occurrence and modifications of cellulose resulting from the synthetic process, morphology of the hydrogels, their thermal stability, and viscoelastic-extensional properties, respectively. Hydrogels liquid uptake capability and ionic conductivity, derived from absorption of aqueous electrolytic solutions, have been evaluated, to assess the successful applicability of the proposed membranes as gel electrolytes for electrochemical devices. To this purpose, the redox behavior of electroactive species entrapped into the hydrogels has been investigated by cyclic voltammetry tests, revealing very high reversibility and ion diffusivity.

  8. Na Reactivity toward Carbonate-Based Electrolytes: The Effect of FEC as Additive

    OpenAIRE

    Dugas, R.; Ponrouch, Alexandre; Gachot, G; David, R.; Palacín, M. Rosa; Tarascon, Jean-Marie

    2016-01-01

    Na-ion batteries have regained attention because they offer sustainability advantages over the Li-ion technology, hence their interest for massive electrochemical storage. Although the Na-ion electrochemistry is analogous to that of the Li-ion concept, there are a few notable differences such as the stability of carbonated-based electrolytes toward the Li or Na metal anodes. Herein we report on the positive effect of FEC as electrolyte additive on the efficiency of Na-half cells which unfortu...

  9. Instability of Ionic Liquid-Based Electrolytes in Li−O2 Batteries

    DEFF Research Database (Denmark)

    Das, Supti; Højberg, Jonathan; Knudsen, Kristian Bastholm

    2015-01-01

    of the rechargeability (OER/ORR), and thereby the Coulombic efficiency of discharge and charge. None of the IL-based electrolytes are found to behave as needed for a functional Li−O2 battery but perform better than commonly used organic solvents. Also the extent of rechargeability/reversibility has been found......Ionic liquids (ILs) have been proposed as promising solvents for Li−air battery electrolytes. Here, several ILs have been investigated using differential electrochemical mass spectrometry (DEMS) to investigate the electrochemical stability in a Li−O2 system, by means of quantitative determination...

  10. Role of perfluoropolyether-based electrolytes in lithium metal batteries: Implication for suppressed Al current collector corrosion and the stability of Li metal/electrolytes interfaces

    Science.gov (United States)

    Cong, Lina; Liu, Jia; Armand, Michel; Mauger, Alain; Julien, Christian M.; Xie, Haiming; Sun, Liqun

    2018-03-01

    The development of safe and high performance lithium metal batteries represents a major technological challenge for this new century. Historically, intrinsic instabilities of conventional liquid organic electrolytes induced battery failures and safety issues that hinder the practical utilization of advanced rechargeable lithium metal batteries. Herein, we report a multifunctional perfluoropolyether-based liquid polymer electrolyte (PFPE-MC/LiTFSI), presenting a unique "anion-solvent" interaction. This interaction optimizes the interfacial chemistry of lithium metal batteries, which effectively inhibits the corrosion of aluminum current collectors, suppresses lithium dendrite growth, and also facilitates the formation of a thin and stable SEI layer on Li anode. Even at a high current density of 0.7 mA cm-2, the lithium dendrites do not form after 1360 h of continuous operation. The LiFePO4|PFPE-MC/LiTFSI|Li cell delivers a stable cycling performance with over 99.9% columbic efficiency either at ambient temperature or high temperature, which is significantly superior to those using traditional carbonate electrolytes. In addition, PFPE-MC/LiTFSI electrolyte also possesses eye-catching properties, such as being non-flammable, non-volatile, non-hygroscopic, and existing in the liquid state between -90 °C and 200 °C, which further ensures the high safety of the lithium metal batteries, making this electrolyte promising for the development of high energy lithium metal batteries.

  11. Synthesis and characterization of γ-Bi2O3 based solid electrolyte ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 37; Issue 4. Synthesis and characterization of -Bi2O3 based solid electrolyte doped with Nb2O5. Handan Ozlu Soner Cakar Caner Bilir Ersay Ersoy Orhan Turkoglu. Volume 37 Issue 4 June 2014 pp 843-848 ...

  12. New operational modes for the Ta2O5-based electrolyte conductance cell

    NARCIS (Netherlands)

    Olthuis, Wouter; Smith, A.; van der Zalm, R.A.J.; Bergveld, Piet

    1994-01-01

    Based on the recently presented conductance cell, two specific operational modes are proposed. In the oscillator mode, the conductivity of the electrolyte determines the frequency of an oscillator, experimentally obtaining a shift from 10 to 27 kHz for a KCl concentration range from 0.5 to 100 mM.

  13. The incidence of electrolyte and acid-base abnormalities in critically ...

    African Journals Online (AJOL)

    Background: Electrolytes and acid-base disorders are common challenges seen in the intensive care unit (ICU) resulting in difficulty in weaning patients off the ventilator, prolonged admission periods, preventable cardiac arrhythmias and cardiac arrest. These require prompt lab results most of which are done serially, ...

  14. Operating mechanisms of electrolytes in magnesium ion batteries: chemical equilibrium, magnesium deposition, and electrolyte oxidation.

    Science.gov (United States)

    Kim, Dong Young; Lim, Younhee; Roy, Basab; Ryu, Young-Gyoon; Lee, Seok-Soo

    2014-12-21

    Since the early nineties there have been a number of reports on the experimental development of Mg electrolytes based on organo/amide-magnesium chlorides and their transmetalations. However, there are no theoretical papers describing the underlying operating mechanisms of Mg electrolytes, and there is no clear understanding of these mechanisms. We have therefore attempted to clarify the operating mechanisms of Mg electrolytes by studying the characteristics of Mg complexes, solvation, chemical equilibrium, Mg-deposition processes, electrolyte-oxidation processes, and oxidative degradation mechanism of RMgCl-based electrolytes, using ab initio calculations. The formation and solvation energies of Mg complexes highly depend on the characteristics of R groups. Thus, changes in R groups of RMgCl lead to changes in the equilibrium position and the electrochemical reduction and oxidation pathways and energies. We first provide a methodological scheme for calculating Mg reduction potential values in non-aqueous electrolytes and electrochemical windows. We also describe a strategy for designing Mg electrolytes to maximize the electrochemical windows and oxidative stabilities. These results will be useful not only for designing improved Mg electrolytes, but also for developing new electrolytes in the future.

  15. Polymer Electrolyte-Based Ambient Temperature Oxygen Microsensors for Environmental Monitoring

    Science.gov (United States)

    Hunter, Gary W.; Xu, Jennifer C.; Liu, Chung-Chiun

    2011-01-01

    An ambient temperature oxygen microsensor, based on a Nafion polymer electrolyte, has been developed and was microfabricated using thin-film technologies. A challenge in the operation of Nafion-based sensor systems is that the conductivity of Nafion film depends on the humidity in the film. Nafion film loses conductivity when the moisture content in the film is too low, which can affect sensor operation. The advancement here is the identification of a method to retain the operation of the Nafion films in lower humidity environments. Certain salts can hold water molecules in the Nafion film structure at room temperature. By mixing salts with the Nafion solution, water molecules can be homogeneously distributed in the Nafion film increasing the film s hydration to prevent Nafion film from being dried out in low-humidity environment. The presence of organics provides extra sites in the Nafion film to promote proton (H+) mobility and thus improving Nafion film conductivity and sensor performance. The fabrication of ambient temperature oxygen microsensors includes depositing basic electrodes using noble metals, and metal oxides layer on one of the electrode as a reference electrode. The use of noble metals for electrodes is due to their strong catalytic properties for oxygen reduction. A conducting polymer Nafion, doped with water-retaining components and extra sites facilitating proton movement, was used as the electrolyte material, making the design adequate for low humidity environment applications. The Nafion solution was coated on the electrodes and air-dried. The sensor operates at room temperature in potentiometric mode, which measures voltage differences between working and reference electrodes in different gases. Repeat able responses to 21-percent oxygen in nitrogen were achieved using nitrogen as a baseline gas. Detection of oxygen from 7 to 21 percent has also been demonstrated. The room-temperature oxygen micro sensor developed has extremely low power

  16. Gibbs energy calculation of electrolytic plasma channel with inclusions of copper and copper oxide with Al-base

    Science.gov (United States)

    Posuvailo, V. M.; Klapkiv, M. D.; Student, M. M.; Sirak, Y. Y.; Pokhmurska, H. V.

    2017-03-01

    The oxide ceramic coating with copper inclusions was synthesized by the method of plasma electrolytic oxidation (PEO). Calculations of the Gibbs energies of reactions between the plasma channel elements with inclusions of copper and copper oxide were carried out. Two methods of forming the oxide-ceramic coatings on aluminum base in electrolytic plasma with copper inclusions were established. The first method - consist in the introduction of copper into the aluminum matrix, the second - copper oxide. During the synthesis of oxide ceramic coatings plasma channel does not react with copper and copper oxide-ceramic included in the coating. In the second case is reduction of copper oxide in interaction with elements of the plasma channel. The content of oxide-ceramic layer was investigated by X-ray and X-ray microelement analysis. The inclusions of copper, CuAl2, Cu9Al4 in the oxide-ceramic coatings were found. It was established that in the spark plasma channels alongside with the oxidation reaction occurs also the reaction aluminothermic reduction of the metal that allows us to dope the oxide-ceramic coating by metal the isobaric-isothermal potential oxidation of which is less negative than the potential of the aluminum oxide.

  17. Use of Additives to Improve Performance of Methyl Butyrate-Based Lithium-Ion Electrolytes

    Science.gov (United States)

    Smart, Marshall C.; Bugga, Ratnakumar V.

    2011-01-01

    This work addresses the need for robust rechargeable batteries that can operate well over a wide temperature range. To this end, a number of electrolyte formulations have been developed that incorporate the use of electrolyte additives to improve the high-temperature resilience, low-temperature power capability, and life characteristics of methyl butyrate-based electrolyte solutions. These electrolyte additives include mono-fluoroethylene carbonate (FEC), lithium oxalate, vinylene carbonate (VC), and lithium bis(oxalato)borate (LiBOB), which have been shown to result in improved high-temperature resilience of all carbonate-based electrolytes. Improved performance has been demonstrated of Li-ion cells with methyl butyrate-based electrolytes, including 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %); 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 2% FEC; 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 4% FEC; 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + lithium oxalate; 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 2% VC; and 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 0.10M LiBOB. These electrolytes have been shown to improve performance in MCMB-LiNiCoO2 and graphite-LiNi1/3Co1/3Mn1/3O2 experimental Li-ion cells. A number of LiPF6-based mixed carbonate electrolyte formulations have been developed that contain ester co-solvents, which have been optimized for operation at low temperature, while still providing reasonable performance at high temperature. For example, a number of ester co-solvents were investigated, including methyl propionate (MP), ethyl propionate (EP), methyl butyrate (MB), ethyl butyrate (EB), propyl butyrate (PB), and butyl butyrate (BB) in multi-component electrolytes of the following composition: 1.0M LiPF6 in ethylene carbonate (EC) + ethyl methyl carbonate (EMC) + X (20:60:20 v/v %) [where X = ester co-solvent]. ["Optimized Car bon ate and Ester-Based Li-Ion Electrolytes", NASA Tech Briefs, Vol. 32, No. 4 (April 2008), p. 56.] Focusing upon improved rate

  18. Electrical, dielectric and electrochemical characterization of novel poly(acrylic acid)-based polymer electrolytes complexed with lithium tetrafluoroborate

    Science.gov (United States)

    Ngai, Koh Sing; Ramesh, S.; Ramesh, K.; Juan, Joon Ching

    2018-01-01

    A series of novel poly(acrylic acid)-based polymer electrolytes with high conductivities at room temperature has been prepared and studied. Polymer electrolytes composed of poly(acrylic acid) (PAA) and lithium tetrafluoroborate (LiBF4) were prepared by means of solution casting. The effect of the addition of LiBF4 on the properties of the PAA-based electrolyte matrices was analysed and investigated using impedance spectroscopy. The optimized PAA-based solid electrolyte showed an electrochemical stability window of 3.2 V. Thermogravimetric analysis indicated that the incorporation of LiBF4 into PAA matrix enhances the thermal stability. The structural properties of polymer electrolytes were studied by using X-ray diffraction analysis.

  19. Electrochemical Reduction of Dissolved Oxygen in Alkaline, Solid Polymer Electrolyte Films.

    Science.gov (United States)

    Novitski, David; Kosakian, Aslan; Weissbach, Thomas; Secanell, Marc; Holdcroft, Steven

    2016-11-30

    Mass transport of oxygen through an ionomer contained within the cathode catalyst layer in an anion exchange membrane fuel cell is critical for a functioning fuel cell, yet is relatively unexplored. Moreover, because water is a reactant in the oxygen reduction reaction (ORR) in alkaline media, an adequate supply of water is required. In this work, ORR mass transport behavior is reported for methylated hexamethyl-p-terphenyl polymethylbenzimidazoles (HMT-PMBI), charge balanced by hydroxide ions (IEC from 2.1 to 2.5 mequiv/g), and commercial Fumatec FAA-3 membranes. Electrochemical mass transport parameters are determined by potential step chronoamperometry using a Pt microdisk solid-state electrochemical cell, in air at 60 °C, with relative humidity controlled between 70% and 98%. The oxygen diffusion coefficient (D bO2 ), oxygen concentration (c bO2 ), and oxygen permeability (D bO2 ·c bO2 ) were obtained by nonlinear curve fitting of the current transients using the Shoup-Szabo equation. Mass transport parameters are correlated to water content of the ionomer membrane. It is found that the oxygen diffusion coefficients decreased by 2 orders of magnitude upon reducing the water content of the ionomer membrane by lowering the relative humidity. The limitation of the Shoup-Szabo equation for extracting ORR mass transport parameters using thin ionomer films was evaluated by numerical modeling of the current transients, which revealed that a significant discrepancy (up to 29% under present conditions) was evident for highly hydrated membranes for which the oxygen diffusion coefficient was largest, and in which the oxygen depletion region reached the ionomer/gas interface during the chronoamperometric analysis.

  20. A new nanocomposite polymer electrolyte based on poly(vinyl alcohol) incorporating hypergrafted nano-silica

    KAUST Repository

    Hu, Xian-Lei

    2012-01-01

    Solid-state nanocomposite polymer electrolytes based on poly(vinyl alcohol)(PVA) incorporating hyperbranched poly(amine-ester) (HBPAE) grafted nano-silica (denoted as SiO2-g-HBPAE) have been prepared and investigated. Through surface pretreatment of nanoparticles, followed by Michael-addition and a self-condensation process, hyperbranched poly(amine-ester) was directly polymerized from the surface of nano-silica. Then the hypergrafted nanoparticles were added to PVA matrix, and blended with lithium perchlorate via mold casting method to fabricate nanocomposite polymer electrolytes. By introducing hypergrafted nanoparticles, ionic conductivity of solid composite is improved significantly at the testing temperature. Hypergrafted nano-silica may act as solid plasticizer, promoting lithium salt dissociation in the matrix as well as improving segmental motion of matrix. In addition, tensile testing shows that such materials are soft and tough even at room temperature. From the dielectric spectra of nanocomposite polymer electrolyte as the function of temperature, it can be deduced that Arrhenius behavior appears depending on the content of hypergrafted nano-silica and concentration of lithium perchlorate. At a loading of 15 wt% hypergrafted nano-silica and 54 wt% lithium perchlorate, promising ionic conductivities of PVA nanocomposite polymer electrolyte are achieved, about 1.51 × 10 -4 S cm-1 at 25 °C and 1.36 × 10-3 S cm-1 at 100 °C. © The Royal Society of Chemistry.

  1. Fabrication of WO3-based electrochromic displays using solid or gel-like organic electrolytes

    International Nuclear Information System (INIS)

    Vasilopoulou, M; Aspiotis, G; Kostis, I; Argitis, P; Davazoglou, D

    2005-01-01

    New all solid-state electrochromic displays were fabricated by chemically vapor depositing and patterning a tungsten oxide film on SnO 2 :F covered glass substrates. Aluminum sheets were used as counter electrodes to form electrochromic displays using solid or gel-like organic electrolytes. These ionically conductive and electronically insulating electrolytes were based on poly(methyl methacrylate) (PMMA) and poly(2-hydrohyethyl methacrylate) (PHEMA) into which phospho-tungstic acid was added at various concentrations. In some devices the electrolyte was formed by addition of photoacid generator into the polymeric matrix and exposure at deep UV light. It was found that displays exhibit an intense, reversible electrochromic effect with reflectivity varying by a factor of five between the uncolored to the colored state. The coloring voltage depends strongly on the polymeric matrix, the thickness of the electrolyte and post-apply baking conditions and is of the order of 6-9 V. The response time was found to be of the order of 500 ms; coloration and bleaching times were comparable

  2. Nanoporous Hybrid Electrolytes for High-Energy Batteries Based on Reactive Metal Anodes

    KAUST Repository

    Tu, Zhengyuan

    2017-01-06

    Successful strategies for stabilizing electrodeposition of reactive metals, including lithium, sodium, and aluminum are a requirement for safe, high-energy electrochemical storage technologies that utilize these metals as anodes. Unstable deposition produces high-surface area dendritic structures at the anode/electrolyte interface, which causes premature cell failure by complex physical and chemical processes that have presented formidable barriers to progress. Here, it is reported that hybrid electrolytes created by infusing conventional liquid electrolytes into nanoporous membranes provide exceptional ability to stabilize Li. Electrochemical cells based on γ-Al2O3 ceramics with pore diameters below a cut-off value above 200 nm exhibit long-term stability even at a current density of 3 mA cm−2. The effect is not limited to ceramics; similar large enhancements in stability are observed for polypropylene membranes with less monodisperse pores below 450 nm. These findings are critically assessed using theories for ion rectification and electrodeposition reactions in porous solids and show that the source of stable electrodeposition in nanoporous electrolytes is fundamental.

  3. Phthaloylchitosan-Based Gel Polymer Electrolytes for Efficient Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    S. N. F. Yusuf

    2014-01-01

    Full Text Available Phthaloylchitosan-based gel polymer electrolytes were prepared with tetrapropylammonium iodide, Pr4NI, as the salt and optimized for conductivity. The electrolyte with the composition of 15.7 wt.% phthaloylchitosan, 31.7 wt.% ethylene carbonate (EC, 3.17 wt.% propylene carbonate (PC, 19.0 wt.% of Pr4NI, and 1.9 wt.% iodine exhibits the highest room temperature ionic conductivity of 5.27 × 10−3 S cm−1. The dye-sensitized solar cell (DSSC fabricated with this electrolyte exhibits an efficiency of 3.5% with JSC of 7.38 mA cm−2, VOC of 0.72 V, and fill factor of 0.66. When various amounts of lithium iodide (LiI were added to the optimized gel electrolyte, the overall conductivity is observed to decrease. However, the efficiency of the DSSC increases to a maximum value of 3.71% when salt ratio of Pr4NI : LiI is 2 : 1. This cell has JSC, VOC and fill factor of 7.25 mA cm−2, 0.77 V and 0.67, respectively.

  4. A new polysiloxane based cross-linker for solid polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yongku; Lee, Junkyoung; Lee, Changjin [Advanced Materials Division, Korea Research Institute of Chemical Technology, P.O. Box 107 Yuseong, Daejeon 305-600 (Korea, Republic of); Suh, Dong Hack [Department of Engineering Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2005-08-26

    A new cross-linker, poly[siloxane-(g-oligo(ethylene oxide)-co-acrylate)], was synthesized and used to prepare the solid polymer electrolytes (SPE) by in situ thermal curing method with the addition of the ion-conducting plasticizers such as low molecular weight poly(ethylene oxide)dimethyl ether (PEGDME) and poly(siloxane-g-ethylene oxide) (PSi-PEG). Increase of conductivity and decrease of T{sub g} were observed as increasing the content of plasticizer. The ionic conductivity was measured to be 7.13x10{sup -4}Scm{sup -1} with 70wt.% PEGDME and 4.18x10{sup -5}Scm{sup -1} with 70wt.% of PSi-PEG at 30{sup o}C. The electrochemical stability window of the resulting solid polymer electrolyte could be extended to up to 4.5V and 5.2V for PEGDME and PSi-PEG, respectively. Thermal stability of polymer electrolyte was greatly enhanced with siloxane based plasticizer. The degradation of SPE with PSi-PEG started at ca. 350{sup o}C. The SPE plasticized with PSi-PEG, which has good electrochemical stability and thermal stability, could be a promising solid polymer electrolyte for lithium polymer batteries. (author)

  5. Polymer Gel Electrolytes Based on 49 % Methyl-Grafted Natural Rubber

    International Nuclear Information System (INIS)

    Kamisan, A.S.; Kudin, T.I.T.; Ali, A.M.M.; Yahya, M.Z.A.; Yahya, M.Z.A.

    2011-01-01

    Polymer gel electrolytes (PGEs) based on 49 % methyl-grafted natural rubber (MG49) were first prepared by dissolving ammonium triflate (NH 4 CF 3 SO 3 ) in propylene carbonate (PC) by various molar concentrations of NH 4 CF 3 SO 3 to obtain liquid electrolytes and were characterized by AC electrical impedance spectroscopy (EIS) measurements to study their conducting behaviour. The liquid electrolyte with optimum conductivity (0.7 M) was then gelled with MG49 and their conductivity was also studied. The highest conductivity of liquid electrolyte was 3.6 x 10 -3 Scm -1 and 2.9x10 -2 Scm -1 for PGEs. The molecular interactions between components of NH 4 CF 3 SO 3 , PC, and MG49 have been observed by ATR-FTIR spectroscopy study. The downshifting of C=O stretching frequency of PC from 1785 cm -1 to 1780 cm -1 and NH 4+ band from 1634 cm -1 to 1626 cm -1 that has been obtained by spectroscopic data in addition of NH 4 CF 3 SO 3 confirmed the complexation occurrence. Interaction between NH 4 CF 3 SO 3 and MG49 has also been investigated. This study is focused on the interactions between components in the PGE system and relates them with their conducting behavior. (author)

  6. Electrochemical and thermal properties of polymer electrolytes based on poly(epichlorohydrin-co-ethylene oxide-co-ally glycidyl ether)

    International Nuclear Information System (INIS)

    Rodrigues, L.C.; Barbosa, P.C.; Silva, M.M.; Smith, M.J.

    2007-01-01

    A series of novel electrolytes based on the terpolymer host, poly(epichlorohydrin-co-ethylene oxide-co-allyl glycidyl ether) with lithium perchlorate and lithium bis(trifluoromethanesulfonyl)imide have been prepared and characterized by conductivity measurements, cyclic voltammetry at a gold microelectrode and thermal analysis. Electrolyte compositions, represented as p(EEO-AGE)LiX(wt%), were produced with lithium salt compositions between 0.5 and 53 wt% (where wt% indicates amount of lithium salt present in the epichlorohydrin-co-ethylene oxide-co-allyl glycidyl host matrix). The guest salt and host polymer were dissolved in tetrahydrofuran and cast to produce thin, free-standing electrolyte films. The p(EEO-AGE)LiX(wt%) (X = ClO 4 and TFSI) electrolytes showed encouraging levels of ionic conductivity and acceptable thermal stability. Electrolytes based on this host polymer were obtained as completely amorphous films with good mechanical properties

  7. Study on Zinc Oxide-Based Electrolytes in Low-Temperature Solid Oxide Fuel Cells.

    Science.gov (United States)

    Xia, Chen; Qiao, Zheng; Feng, Chu; Kim, Jung-Sik; Wang, Baoyuan; Zhu, Bin

    2017-12-28

    Semiconducting-ionic conductors have been recently described as excellent electrolyte membranes for low-temperature operation solid oxide fuel cells (LT-SOFCs). In the present work, two new functional materials based on zinc oxide (ZnO)-a legacy material in semiconductors but exceptionally novel to solid state ionics-are developed as membranes in SOFCs for the first time. The proposed ZnO and ZnO-LCP (La/Pr doped CeO₂) electrolytes are respectively sandwiched between two Ni 0.8 Co 0.15 Al 0.05 Li-oxide (NCAL) electrodes to construct fuel cell devices. The assembled ZnO fuel cell demonstrates encouraging power outputs of 158-482 mW cm -2 and high open circuit voltages (OCVs) of 1-1.06 V at 450-550 °C, while the ZnO-LCP cell delivers significantly enhanced performance with maximum power density of 864 mW cm -2 and OCV of 1.07 V at 550 °C. The conductive properties of the materials are investigated. As a consequence, the ZnO electrolyte and ZnO-LCP composite exhibit extraordinary ionic conductivities of 0.09 and 0.156 S cm -1 at 550 °C, respectively, and the proton conductive behavior of ZnO is verified. Furthermore, performance enhancement of the ZnO-LCP cell is studied by electrochemical impedance spectroscopy (EIS), which is found to be as a result of the significantly reduced grain boundary and electrode polarization resistances. These findings indicate that ZnO is a highly promising alternative semiconducting-ionic membrane to replace the electrolyte materials for advanced LT-SOFCs, which in turn provides a new strategic pathway for the future development of electrolytes.

  8. Microporous gel electrolytes based on amphiphilic poly(vinylidene fluoride-co-hexafluoropropylene) for lithium batteries

    International Nuclear Information System (INIS)

    Yu Shicheng; Chen Lie; Chen Yiwang; Tong Yongfen

    2012-01-01

    Poly(vinylidene fluoride-co-hexafluoropropylene) grafted poly(poly(ethylene glycol) methyl ether methacrylate) (PVDF-HFP-g-PPEGMA) is simply prepared by single-step synthesis directly via atom transfer radical polymerization (ATRP) of poly(ethylene glycol) methyl ether methacrylate (PEGMA) from poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). Thermal, mechanical, swelling and electrochemical properties, as well as microstructures of the prepared polymer electrolytes, are evaluated and the effects of the various contents and average molecular weights of PEGMA on those properties are also been investigated. By phase inversion technique, the copolymer membranes tend to form well-defined microporous morphology with the increase of content and average molecular weight of PEGMA, due to the competition and cooperation between the hydrophilic PEGMA segments and hydrophobic PVDF-HFP. When these membranes are gelled with 1 M LiCF 3 SO 3 in ethylene carbonate (EC)/propylene carbonate (PC) (1:1, v/v), their saturated electrolyte uptakes (up to 323.5%) and ion conductivities (up to 2.01 × 10 -3 S cm -1 ) are dramatically improved with respect to the pristine PVDF-HFP, ascribing to the strong affinity of the hydrophilic PEGMA segments with the electrolytes. All the polymer electrolytes are electrochemically stable up to 4.7 V versus Li/Li + , and show good mechanical properties. Coin cells based on the polymer electrolytes show stable charge-discharge cycles and deliver discharge capacities to LiFePO 4 is up to 156 mAh g -1 .

  9. Electrolyte and Acid-Base Disturbances in End-Stage Liver Disease: A Physiopathological Approach.

    Science.gov (United States)

    Jiménez, José Víctor; Carrillo-Pérez, Diego Luis; Rosado-Canto, Rodrigo; García-Juárez, Ignacio; Torre, Aldo; Kershenobich, David; Carrillo-Maravilla, Eduardo

    2017-08-01

    Electrolyte and acid-base disturbances are frequent in patients with end-stage liver disease; the underlying physiopathological mechanisms are often complex and represent a diagnostic and therapeutic challenge to the physician. Usually, these disorders do not develop in compensated cirrhotic patients, but with the onset of the classic complications of cirrhosis such as ascites, renal failure, spontaneous bacterial peritonitis and variceal bleeding, multiple electrolyte, and acid-base disturbances emerge. Hyponatremia parallels ascites formation and is a well-known trigger of hepatic encephalopathy; its management in this particular population poses a risky challenge due to the high susceptibility of cirrhotic patients to osmotic demyelination. Hypokalemia is common in the setting of cirrhosis: multiple potassium wasting mechanisms both inherent to the disease and resulting from its management make these patients particularly susceptible to potassium depletion even in the setting of normokalemia. Acid-base disturbances range from classical respiratory alkalosis to high anion gap metabolic acidosis, almost comprising the full acid-base spectrum. Because most electrolyte and acid-base disturbances are managed in terms of their underlying trigger factors, a systematic physiopathological approach to their diagnosis and treatment is required.

  10. Reoxidation of uranium metal immersed in a Li2O-LiCl molten salt after electrolytic reduction of uranium oxide

    Science.gov (United States)

    Choi, Eun-Young; Jeon, Min Ku; Lee, Jeong; Kim, Sung-Wook; Lee, Sang Kwon; Lee, Sung-Jai; Heo, Dong Hyun; Kang, Hyun Woo; Jeon, Sang-Chae; Hur, Jin-Mok

    2017-03-01

    We present our findings that uranium (U) metal prepared by using the electrolytic reduction process for U oxide (UO2) in a Li2O-LiCl salt can be reoxidized into UO2 through the reaction between the U metal and Li2O in LiCl. Two salt types were used for immersion of the U metal: one was the salt used for electrolytic reduction, and the other was applied to the unused LiCl salts with various concentrations of Li2O and Li metal. Our results revealed that the degree of reoxidation increases with the increasing Li2O concentration in LiCl and that the presence of the Li metal in LiCl suppresses the reoxidation of the U metal.

  11. Germanium sulfide-based solid electrolytes for non-volatile memory

    Science.gov (United States)

    Balakrishnan, Muralikrishnan

    Programmable Metallization Cell (PMC) technology involves the storage of data as reduced metal ions in a solid electrolyte. Earlier work on Selenide-based (Ag-Ge-Se) PMC devices requires relatively low back-end-of-line processing (BEOL) since the electrolyte may undergo undesirable changes at process temperatures in excess of 200°C. This dissertation is focused on Sulfide-based (Ag/Cu-Ge-S) solid electrolytes which have better temperature stability and the PMC technology based on these materials is compatible with most BEOL process in CMOS Integrated Circuits. The devices fabricated using Ag-Ge-S and Cu-Ge-S solid electrolytes were tested after annealing at 300°C and 430°C. Extensive material analysis was performed on both the systems in an effort to understand the behavior of the devices at elevated temperatures. Electrical characterization testing involved standard memory characterization techniques such as quasi-static measurements tests, retention tests, speed tests, elevated temperature operation tests and endurance tests. The Ag-Ge-S PMC devices were made with different compositions to find out the optimum composition which would ensure reliable operation even after the high temperature anneal. The Sulfide-based PMC devices were also tested for reconfigurable logic applications with special test structures that would demonstrate the low resistance connections that can be achieved by programming the PMC elements using higher currents. Optimum composition of the starting glass was found from the material and data analysis, to ensure reliable operation of the Sulfide-based PMC devices with no degradation in the electrical characteristics even after the typical BEOL anneal.

  12. Ensembles of Classifiers based on Dimensionality Reduction

    OpenAIRE

    Schclar, Alon; Rokach, Lior; Amit, Amir

    2013-01-01

    We present a novel approach for the construction of ensemble classifiers based on dimensionality reduction. Dimensionality reduction methods represent datasets using a small number of attributes while preserving the information conveyed by the original dataset. The ensemble members are trained based on dimension-reduced versions of the training set. These versions are obtained by applying dimensionality reduction to the original training set using different values of the input parameters. Thi...

  13. Optimization of Microporous Carbon Structures for Lithium-Sulfur Battery Applications in Carbonate-Based Electrolyte.

    Science.gov (United States)

    Hu, Lei; Lu, Yue; Li, Xiaona; Liang, Jianwen; Huang, Tao; Zhu, Yongchun; Qian, Yitai

    2017-03-01

    Developing appropriate sulfur cathode materials in carbonate-based electrolyte is an important research subject for lithium-sulfur batteries. Although several microporous carbon materials as host for sulfur reveal the effect, methods for producing microporous carbon are neither easy nor well controllable. Moreover, due to the complexity and limitation of microporous carbon in their fabrication process, there has been rare investigation of influence on electrochemical behavior in the carbonate-based electrolyte for lithium-sulfur batteries by tuning different micropore size(0-2 nm) of carbon host. Here, we demonstrate an immediate carbonization process, self-activation strategy, which can produce microporous carbon for a sulfur host from alkali-complexes. Besides, by changing different alkali-ion in the previous complex, the obtained microporous carbon exhibits a major portion of ultramicropore (structure of the host material plays a vital role in confining sulfur molecule. When evaluated as cathode materials in a carbonate-based electrolyte for Li-S batteries, such microporous carbon/sulfur composite can provide high reversible capacity, cycling stability and good rate capability. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Nano integrated lithium polymer electrolytes based on anodic aluminum oxide (AAO) templates

    Science.gov (United States)

    Bokalawela, Roshan S. P.

    :1) electrolyte are aligned along the pore axis and that the structure is ordered in the nano pores. This was based on our observations that the intensity of the PEO crystalline peaks at 19.2° (120) and 23.0° [(hk2) and (hk4)] when the incident x-ray beam was parallel to the pore axes was reduced, but intensity of recovered when the pores were tilted by 10° with respect to the incident x-ray beam. Exploring the infra-redred and Raman vibrational spectra of nano-confined pure PEO and PEO:LiTf(10:1) structures with the bulk films, we found that the IR absorbance bands and the Raman intensities showed a high dichroism to the normal and parallel electric fields of the IR radiation. The parallel band intensity decreased while the normal band intensity increased, consistent with an alignment of the polymer chains along the pore direction. To perform this research, on our millimeter-sized, hygroscopic samples, substantial changes in the implementation of the characterization techniques such as: AC-impedance spectroscopy, FTIR, Raman-scattering, WAXS, and SEM were required. These changes included: new sample holders to prevent water uptake; a new method to align samples to ensure consistent and reproducible measurements with the new holder designs; and the development and implementation of an entirely new system for measuring the conductivity versus temperature of our template samples in a glovebox. The Appendices at the end of this thesis include details of the developed procedures and apparatus, as well as additional experimental results not shown in the thesis.

  15. PC based electrolytes with LiDFOB as an alternative salt for lithium-ion batteries

    Science.gov (United States)

    Knight, Brandon M.

    Lithium-ion batteries (LIBs) have been greatly sought after as a source of renewable energy storage. LIBs have a wide range of applications including but not limited portable electronic devices, electric vehicles, and power tools. As a direct result of their commercial viability an insatiable hunger for knowledge, advancement within the field of LIBs has been omnipresent for the last two decades. However, there are set backs evident within the LIB field; most notably the limitations of standard electrolyte formulations and LiPF6 lithium salt. The standard primary carbonate of ethylene carbonate (EC) has a very limited operating range due to its innate physical properties, and the LiPF6 salt is known to readily decompose to form HF which can further degrade LIB longevity. The goal of our research is to explore the use of a new primary salt LiDFOB in conjunction with a propylene carbonate based electrolyte to establish a more flexible electrolyte formulation by constructing coin cells and cycling them under various conditions to give a clear understanding of each formulation inherent performance capabilities. Our studies show that 1.2M LiDFOB in 3:7 PC/EMC + 1.5% VC is capable of performing comparably to the standard 1.2M LiPF6 in 3:7 EC/EMC at 25°C and the PC electrolyte also illustrates performance superior to the standard at 55°C. The degradation of lithium manganese spinel electrodes, including LiNi 0.5Mn1.5O4, is an area of great concern within the field of lithium ion batteries (LIBs). Manganese containing cathode materials frequently have problems associated with Mn dissolution which significantly reduces the cycle life of LIB. Thus the stability of the cathode material is paramount to the performance of Mn spinel cathode materials in LIBs. In an effort to gain a better understanding of the stability of LiNi0.5 Mn1.5O4 in common LiPF6/carbonate electrolytes, samples were stored at elevated temperature in the presence of electrolyte. Then after storage both

  16. Features of Porous Anodic Alumina Growth in Galvanostatic Regime in Selenic Acid Based Electrolyte

    International Nuclear Information System (INIS)

    Nazarkina, Y.; Kamnev, K.; Dronov, A.; Dudin, A.; Pavlov, A.; Gavrilov, S.

    2017-01-01

    The features of porous anodic Al 2 O 3 formation process in galvanostatic regime in selenic acid based electrolyte under a range of anodization conditions were investigated. The growth process kinetics of porous anodic Al 2 O 3 was characterized by chronopotentiometric curves. The effect of electrolyte concentration, current density and anodization duration on the oxide porous structure ordering was studied by scanning electron microscopy. Approximate regions of self-ordered porous Al 2 O 3 formation process conditions were estimated. It was found that anodization parameters, at which self-ordered porous structure formation is observed, correspond to the conditions of equilibrium of oxidation and etching rates. It is shown that deviations from these conditions lead to the disordering of the porous structure.

  17. Composite polymer electrolyte based on PEO/Pvdf-HFP with MWCNT for lithium battery applications

    Energy Technology Data Exchange (ETDEWEB)

    Pradeepa, P.; Edwinraj, S.; Sowmya, G.; Kalaiselvimary, J.; Selvakumar, K.; Prabhu, M. Ramesh, E-mail: email-mkram83@gmail.com [Department of Physics, Alagappa University, Karaikudi – 630 004 (India)

    2016-05-06

    In the present study PEO and PVdF-HFP blend based composite polymer electrolytes (CPEs) has been prepared by using Multi Walled Carbon Nanotube (MWCNT), in order to examine the filler addition effect on the electrochemical properties. The complexed nanocomposite polymer electrolytes were obtained in the form of dimensionally stable and free standing films by using solution casting technique. The electrochemical properties of CPEs were measured by the AC impedance method. From the ionic conductivity results, the CPE containing MWCNT 2wt% showed the highest ionic conductivity with an excellent thermal stability at room temperature. The dielectric loss curve s for the sample 6.25wt% PEO: 18.75 wt% PVdF-HFP: 2wt% MWCNT reveal the low frequency β relaxation peak pronounced at high temperature, and it may caused by side group dipoles.

  18. High temperature electrolyzer based on solid oxide co-ionic electrolyte: A theoretical model

    Energy Technology Data Exchange (ETDEWEB)

    Demin, Anatoly; Gorbova, Elena [Institute of High Temperature Electrochemistry, 22 S. Kovalevskoy, 620219 Yekaterinburg (Russian Federation); Tsiakaras, Panagiotis [School of Engineering, Department of Mechanical Engineering, University of Thessaly, Pedion Areos, 383 34 Volos (Greece)

    2007-09-19

    In the present work a theoretical model of a solid oxide electrolyzer based on an electrolyte having both oxygen ion and proton conductivity is considered. The main parameters of the electrolytic process and an electrolyzer (distribution of gas components, electromotive forces and current densities along the electrolyzer channel, average values of electromotive forces and current densities) were calculated depending on a proton transport number and mode of the reactants' feeding (co- and counter-flow). The performed analysis demonstrates considerable influence of the mode of feeding on all parameters of the electrolyzer: operation under the counter-flow mode is preferable as regards the specific characteristics and uniformity of their distribution along the electrolyzer. It is shown that the electrolyser's specific characteristics increase with the increase of the proton transport number. (author)

  19. Enhanced Proton Conductivity and Methanol Permeability Reduction via Sodium Alginate Electrolyte-Sulfonated Graphene Oxide Bio-membrane

    Science.gov (United States)

    Shaari, N.; Kamarudin, S. K.; Basri, S.; Shyuan, L. K.; Masdar, M. S.; Nordin, D.

    2018-03-01

    The high methanol crossover and high cost of Nafion® membrane are the major challenges for direct methanol fuel cell application. With the aim of solving these problems, a non-Nafion polymer electrolyte membrane with low methanol permeability and high proton conductivity based on the sodium alginate (SA) polymer as the matrix and sulfonated graphene oxide (SGO) as an inorganic filler (0.02-0.2 wt%) was prepared by a simple solution casting technique. The strong electrostatic attraction between -SO3H of SGO and the sodium alginate polymer increased the mechanical stability, optimized the water absorption and thus inhibited the methanol crossover in the membrane. The optimum properties and performances were presented by the SA/SGO membrane with a loading of 0.2 wt% SGO, which gave a proton conductivity of 13.2 × 10-3 Scm-1, and the methanol permeability was 1.535 × 10-7 cm2 s-1 at 25 °C, far below that of Nafion (25.1 × 10-7 cm2 s-1) at 25 °C. The mechanical properties of the sodium alginate polymer in terms of tensile strength and elongation at break were improved by the addition of SGO.

  20. Manufacturing of Dysprosium-Iron Alloys by Electrolysis in Fluoride-Based Electrolytes: Oxide Solubility Determinations

    Science.gov (United States)

    Martinez, Ana Maria; Støre, Anne; Osen, Karen Sende

    2018-04-01

    Electrolytic production of light rare earth elements and alloys takes place in a fluoride-based electrolyte using rare earth oxides as raw material. The optimization of this method, mainly in terms of the energy efficiency and environmental impact control, is rather challenging. Anode effects, evolution of fluorine-containing compounds, and side cathode reactions could largely be minimized by a good control of the amount of rare earth oxide species dissolved in the fluoride-based electrolyte and their dissolution rate. The oxide content of the fluoride melts REF3-LiF (RE = Nd, Dy) at different compositions and temperatures were experimentally determined by carbothermal analysis of melt samples. The highest solubility values of oxide species, added as Dy2O3 and Dy2(CO3)3, were obtained to be of ca. 3 wt pct (expressed as Dy2O3) in the case of the equimolar DyF3-LiF melt at 1323 K (1050 °C). The oxide saturation values increased with the amount of REF3 present in the molten bath and the working temperature.

  1. Preparation and characterization of poly(vinylidene fluoride) based composite electrolytes for electrochemical devices

    International Nuclear Information System (INIS)

    Karabelli, D.; Leprêtre, J.-C.; Cointeaux, L.; Sanchez, J.-Y.

    2013-01-01

    Highlights: • Macroporous PVdF based membranes for electrochemical applications were prepared with support materials. • Woven PET and PA fabrics and non-woven cellulose paper are used as support materials. • Porous structure of PVdF was obtained on the support material. • Interaction between the electrolyte solvent and the composite material played an important role on the mechanical properties. • Compared to the pure PVdF separators, enhanced mechanical strength was obtained for composite separators, without decreasing the ionic conductivity. -- Abstract: PVdF-based separators are very promising materials in electrochemical energy storage systems but they suffer from fairly poor mechanical properties. To overcome this drawback, composite PVdF separators were fabricated and characterized in electrolytes of Li-ion batteries and supercapacitors. Macroporous PVdF composite separators were prepared by phase inversion method using PA and PET, and non-woven cellulose as support layers. Ionic conductivity and thermomechanical analyses were performed using electrolytes of Li-ion batteries and supercapacitors. The composite approach allowed a tremendous increase of the mechanical performances of the separator (between 340 and 750 MPa) compared to the unreinforced PVdF separator (56 MPa), without compromising the ionic conductivities (up to 15.6 mS cm −1 )

  2. Redox Species-Based Electrolytes for Advanced Rechargeable Lithium Ion Batteries

    KAUST Repository

    Ming, Jun

    2016-08-15

    Seeking high-capacity cathodes has become an intensive effort in lithium ion battery research; however, the low energy density still remains a major issue for sustainable handheld devices and vehicles. Herein, we present a new strategy of integrating a redox species-based electrolyte in batteries to boost their performance. Taking the olivine LiFePO4-based battery as an example, the incorporation of redox species (i.e., polysulfide of Li2S8) in the electrolyte results in much lower polarization and superior stability, where the dissociated Li+/Sx2– can significantly speed up the lithium diffusion. More importantly, the presence of the S82–/S2– redox reaction further contributes extra capacity, making a completely new LiFePO4/Li2Sx hybrid battery with a high energy density of 1124 Wh kgcathode–1 and a capacity of 442 mAh gcathode–1. The marriage of appropriate redox species in an electrolyte for a rechargeable battery is an efficient and scalable approach for obtaining higher energy density storage devices.

  3. Surface Properties of PAN-based Carbon Fibers Modified by Electrochemical Oxidization in Organic Electrolyte Systems

    Directory of Open Access Journals (Sweden)

    WU Bo

    2016-09-01

    Full Text Available PAN-based carbon fibers were modified by electrochemical oxidization using fatty alcohol polyoxyethylene ether phosphate (O3P, triethanolamine (TEOA and fatty alcohol polyoxyethylene ether ammonium phosphate (O3PNH4 as organic electrolyte respectively. Titration analysis, single fiber fracture strength measurement and field emission scanning electron microscopy (FE-SEM were used to evaluate the content of acidic functional group on the surface, mechanical properties and surface morphology of carbon fiber. The optimum process of electrochemical treatment obtained is at 50℃ for 2min and O3PNH4 (5%, mass fraction as the electrolyte with current density of 2A/g. In addition, the surface properties of modified carbon fibers were characterized by X-ray photoelectron spectroscopy (XPS and single fiber contact angle test. The results show that the hydrophilic acidic functional groups on the surface of carbon fiber which can enhance the surface energy are increased by the electrochemical oxidation using O3PNH4 as electrolyte, almost without any weakening to the mechanical properties of carbon fiber.

  4. Solid polymer electrolytes based on alternating copolymers of vinyl ethers with methoxy oligo(ethyleneoxy)ethyl groups and vinylene carbonate

    International Nuclear Information System (INIS)

    Itoh, Takahito; Fujita, Katsuhito; Inoue, Kentaro; Iwama, Hiroki; Kondoh, Kensaku; Uno, Takahiro; Kubo, Masataka

    2013-01-01

    Graphical abstract: - Highlights: • Synthesis of alternating copolymers of vinyl ethers and vinylene carbonate. • Preparation of polymer electrolytes based on the alternating copolymers with LiTFSI. • Structure-property relationship for alternating copolymers-based electrolytes. • Interfacial stability between polymer electrolytes with lithium metal electrode. - Abstract: Alternating copolymers (poly(1a-g-alt-VC)) of vinyl ethers with various methoxy oligo(ethyleneoxy)ethyl groups and vinylene carbonate (VC) were prepared, and the thermal and electrochemical properties of their polymer electrolytes with LiTFSI and interfacial stability between the polymer electrolyte and Li metal electrode were investigated. T g 's increased linearly with salt contents, and decreased with an increase in the chain length of methoxy oligo(ethyleneoxy)ethyl groups in the vinyl ethers at constant salt concentration. The slopes of T g vs. [Li]/[O] were identical, independent of the polymer structure. The ionic conductivities of the polymer electrolytes increased with increasing the side-chain ethyleneoxy (EO) unit length of the vinyl ether unit in the alternating copolymers, and also their temperature dependences became relatively smaller in the polymer electrolytes having longer EO units in the vinyl ethers. The highest ionic conductivity, 1.2 × 10 −4 S/cm at 30 °C, was obtained in the alternating copolymer with a side-chain EO unit length of 23.5 in the vinyl ether unit. Ion transport coupled with the segmental motion of the polymer is dominant in these polymer electrolytes. Interfacial resistance increased gradually with contact time, indicative of the formation of passivation films on the Li metal electrode. These polymer electrolytes are thermally stable and have large electrochemical windows of use

  5. Chemical and thermomechanical compatibility between neodymium manganites and electrolytes based on ceria

    Directory of Open Access Journals (Sweden)

    Gil, V.

    2008-06-01

    Full Text Available The goal of this work was to study the thermal expansion behaviour and to establish the phase relations between NdMe0.5Mn0.5O3 (Me=Ni, Co solid solutions as cathodes and two electrolytes based on Ce0.9Gd0.1O1.95. Doping of electrolyte with 1.0 wt% Bi2O3 was employed in order to improve the densification process. The cathode-electrolyte pairs were obtained by isostatic pressing of constituent powders and posterior sintering using the temperature ranges between 1350–1400 ºC for 2 h. The sintering conditions were optimized to obtain highly densificated electrolytes and well-developed cathode-electrolyte interfaces. Scanning electron microscopy observation with EDAX analysis was performed in cathode-electrolyte interfacial regions in order to characterize the obtained microstructures and to determine possible cation diffusions from the cathode into the electrolyte. It is found that the nickel doped manganite, NdNi0.5Mn0.5O3, is chemically and thermo-mechanically compatible with both electrolytes without formation of new phases up to 1400ºC even during long time of treatments.

    El propósito del presente trabajo es establecer las relaciones de fase entre soluciones sólidas NdMe0.5Mn0.5O3 (Me=Ni, Co y electrolitos Ce0.9Gd0.1O1.95 para su uso como cátodos y electrolitos SOFC, respectivamente. El electrolito fue en ocasiones dopado con 1.0 wt% Bi2O3 con el objeto de mejorar su densificación. Así mismo se estudia el comportamiento termomecánico de dichos materiales. Los pares cátodo-electrolito fueron obtenidos a partir de polvos prensados isostáticamente y posteriormente sinterizados utilizando unos rangos de temperatura entre 1350 y 1400ºC durante 2h. Las condiciones de sinterización fueron optimizadas para obtener unos electrolitos altamente densificados y unas interfaces cátodo-electrolito bien definidas. La caracterización microestructural de las regiones interfaciales fue llevada a cabo mediante microscopía electrónica de

  6. Low temperature electrochemical cells with sodium β″-alumina solid electrolyte (BASE)

    Science.gov (United States)

    Girija, T. C.; Virkar, Anil V.

    Cells of Daniell-type with copper-zinc electrochemical couples and sodium β″-alumina solid electrolyte (BASE) were constructed. The cathode consisted of copper in contact with its ions (Cu/Cu 2+) while zinc in contact with its ions (Zn/Zn 2+) constituted the anode. Dimethyl sulfoxide (DMSO) containing 1 M NaBF 4 was used as the liquid electrolyte. The configuration of the cell constructed can be written as follows: Zn(s)/ZnCl 2(DMSO)(0.1 M), NaBF 4(1 M)/BASE/NaBF 4(1 M), CuCl 2(DMSO)(0.1 M)/Cu(s). The cell was subjected to charge-discharge cycles at 100 °C. The BASE discs were found to be stable even after the cell was subjected to several electrochemical charge-discharge cycles. Cells were also constructed using BASE discs with porous BASE surface layers introduced to lower the interfacial resistance. Cells with surface modified BASE exhibited a lower resistance in comparison to those using unmodified BASE. XRD and SEM analyses indicated that no detectable degradation of BASE discs occurred after cell testing. Preliminary cell tests were also conducted with NaCF 3SO 3 in place of NaBF 4.

  7. Low temperature electrochemical cells with sodium {beta}''-alumina solid electrolyte (BASE)

    Energy Technology Data Exchange (ETDEWEB)

    Girija, T.C.; Virkar, Anil V. [Department of Materials Science and Engineering, 122 S. Central Campus Drive, University of Utah, Salt Lake City, UT 84112 (United States)

    2008-05-15

    Cells of Daniell-type with copper-zinc electrochemical couples and sodium {beta}''-alumina solid electrolyte (BASE) were constructed. The cathode consisted of copper in contact with its ions (Cu/Cu{sup 2+}) while zinc in contact with its ions (Zn/Zn{sup 2+}) constituted the anode. Dimethyl sulfoxide (DMSO) containing 1 M NaBF{sub 4} was used as the liquid electrolyte. The configuration of the cell constructed can be written as follows: Zn(s)/ZnCl{sub 2}(DMSO)(0.1 M), NaBF{sub 4}(1 M)/BASE/NaBF{sub 4}(1 M), CuCl{sub 2}(DMSO)(0.1 M)/Cu(s) The cell was subjected to charge-discharge cycles at 100 C. The BASE discs were found to be stable even after the cell was subjected to several electrochemical charge-discharge cycles. Cells were also constructed using BASE discs with porous BASE surface layers introduced to lower the interfacial resistance. Cells with surface modified BASE exhibited a lower resistance in comparison to those using unmodified BASE. XRD and SEM analyses indicated that no detectable degradation of BASE discs occurred after cell testing. Preliminary cell tests were also conducted with NaCF{sub 3}SO{sub 3} in place of NaBF{sub 4}. (author)

  8. Investigating continuous co-intercalation of solvated lithium ions and graphite exfoliation in propylene carbonate-based electrolyte solutions

    Science.gov (United States)

    Song, Hee-Youb; Jeong, Soon-Ki

    2018-01-01

    Forming an effective solid electrolyte interphase (SEI) is a significant issue in lithium ion batteries that utilize graphite as a negative electrode material, because the SEI determines the reversibility of the intercalation and de-intercalation of lithium ions into graphite for secondary batteries. In propylene carbonate (PC)-based electrolyte solutions, ceaseless co-intercalation of solvated lithium ions takes place because no effective SEI is formed. It is indisputable that this continuous co-intercalation leads to graphite exfoliation; however, the reason for this is currently not well understood. In this study, we investigate interfacial reactions that contribute to SEI formation on highly oriented pyrolytic graphite (HOPG) in ethylene carbonate (EC) and PC-based electrolyte solutions by in situ atomic force microscopy. The blisters formed on HOPG after the decomposition of solvated lithium ions within the graphite layers do not change over the course of ten electrochemical cycles in an EC-based electrolyte solution. In contrast, when cycling in PC-based electrolytes, the blisters continually change, and the height at the vicinity of the graphite edge plane increases. These morphological changes are attributed to the continuous co-intercalation of solvated lithium ions in PC-based electrolyte solutions.

  9. Application of polyacrylonitrile-based polymer electrolytes in rechargeable lithium batteries

    DEFF Research Database (Denmark)

    Perera, K.S.; Dissanayake, M.A.K.L.; Skaarup, Steen

    2008-01-01

    Polyacrylonitrile (PAN)-based polymer electrolytes have obtained considerable attention due to their fascinating characteristics such as appreciable ionic conductivity at ambient temperatures and mechanical stability. This study is based on the system PAN-ethylene carbonate (EC)-propylene carbonate...... (PC)-lithium trifluoromethanesulfonate (LiCF3SO3). The composition 15 mol% PAN-42 mol% EC-36 mol% PC-7 mol% LiCF3SO3 has shown a maximum room temperature conductivity of 1.2 x 10(-3) stop S cm(-1) stop. Also, it was possible to make a thin, transparent film out of that composition. Cells of the form...

  10. Separation of Electrolytic Reduction Product from Stainless Steel Wire Mesh Cathode Basket via Salt Draining and Reuse of the Cathode Basket

    Directory of Open Access Journals (Sweden)

    Eun-Young Choi

    2017-01-01

    Full Text Available We demonstrated that the metallic product obtained after electrolytic reduction (also called oxide reduction (OR can be simply separated from a stainless steel wire mesh cathode basket only by using a salt drain. First, the OR run of a simulated oxide fuel (0.6 kg/batch was conducted in a molten Li2O–LiCl salt electrolyte at 650°C. The simulated oxide fuel of the porous cylindrical pellets was used as a cathode by loading a stainless steel wire mesh cathode basket. Platinum was employed as an anode. After the electrolysis, the residual salt of the cathode basket containing the reduction product was drained by placing it at gas phase above the molten salt using a holder. Then, at a room temperature, the complete separation of the reduction product from the cathode basket was achieved by inverting it without damaging or deforming the basket. Finally, the emptied cathode basket obtained after the separation was reused for the second OR run by loading a fresh simulated oxide fuel. We also succeeded in the separation of the metallic product from the reused cathode basket for the second OR run.

  11. Detection of distributed static and dynamic loads with electrolyte-enabled distributed transducers in a polymer-based microfluidic device

    International Nuclear Information System (INIS)

    Gu, Wenting; Cheng, Peng; Ghosh, Arindam; Beskok, Ali; Hao, Zhili; Liao, Yuxi; Liao, Boxiong

    2013-01-01

    This paper reports on the use of electrolyte-enabled distributed transducers in a polymer-based microfluidic device for the detection of distributed static and dynamic loads. The core of the device is a polymer rectangular microstructure integrated with electrolyte-enabled distributed transducers. Distributed loads acting on the polymer microstructure are converted to different deflections along the microstructure length, which are further translated to electrical resistance changes by electrolyte-enabled distributed transducers. Owing to the great simplicity of the device configuration, a standard polymer-based fabrication process is employed to fabricate this device. With custom-built electronic circuits and custom LabVIEW programs, fabricated devices filled with two different electrolytes, 0.1 M NaCl electrolyte and 1-ethyl-3-methylimidazolium dicyanamide electrolyte, are characterized, demonstrating the capability of detecting distributed static and dynamic loads with a single device. As a result, the polymer-based microfluidic device presented in this paper is promising for offering the capability of detecting distributed static and dynamic loads in biomedical/surgical, manufacturing and robotics applications. (paper)

  12. Polymer Electrolytes

    Science.gov (United States)

    Hallinan, Daniel T.; Balsara, Nitash P.

    2013-07-01

    This review article covers applications in which polymer electrolytes are used: lithium batteries, fuel cells, and water desalination. The ideas of electrochemical potential, salt activity, and ion transport are presented in the context of these applications. Potential is defined, and we show how a cell potential measurement can be used to ascertain salt activity. The transport parameters needed to fully specify a binary electrolyte (salt + solvent) are presented. We define five fundamentally different types of homogeneous electrolytes: type I (classical liquid electrolytes), type II (gel electrolytes), type III (dry polymer electrolytes), type IV (dry single-ion-conducting polymer electrolytes), and type V (solvated single-ion-conducting polymer electrolytes). Typical values of transport parameters are provided for all types of electrolytes. Comparison among the values provides insight into the transport mechanisms occurring in polymer electrolytes. It is desirable to decouple the mechanical properties of polymer electrolyte membranes from the ionic conductivity. One way to accomplish this is through the development of microphase-separated polymers, wherein one of the microphases conducts ions while the other enhances the mechanical rigidity of the heterogeneous polymer electrolyte. We cover all three types of conducting polymer electrolyte phases (types III, IV, and V). We present a simple framework that relates the transport parameters of heterogeneous electrolytes to homogeneous analogs. We conclude by discussing electrochemical stability of electrolytes and the effects of water contamination because of their relevance to applications such as lithium ion batteries.

  13. Anode-supported single-chamber SOFCs based on gadolinia doped ceria electrolytes

    Directory of Open Access Journals (Sweden)

    Morales, M.

    2008-12-01

    Full Text Available The utilization of anode supported electrolytes is a useful strategy to increase the electrical properties of the solid oxide fuel cells, because it is possible to decrease considerably the thickness of the electrolytes. We have prepared successfully singlechamber fuel cells of gadolinia doped ceria electrolytes Ce1-xGdxO2-y (CGO supported on an anode formed by a cermet of Ni-CGO. Mixtures of precursor powders of NiO and gadolinium doped ceria with different particle sizes and compositions were analyzed to obtain optimal bulk porous anodes to be used as anode supported fuel cells. Doped ceria electrolytes were prepared by sol-gel related techniques. Then, ceria based electrolytes were deposited by dip coating at different thickness (15-30 µm using an ink prepared with nanometric powders of electrolytes dispersed in a commercial liquid polymer. Cathodes of La1-xSrxCoO3-s (LSCO were also prepared by sol-gel related techniques and were deposited by dip coating on the electrolyte thick films. Finally, electrical properties were determined in a single-chamber reactor where propane as fuel was mixed with synthetic air above the higher explosive limit. Stable density currents were obtained in these experimental conditions, but flow rates of the carrier gas and propane partial pressure were determinants for the optimization of the electrical properties of the fuel cells.

    La utilización de electrolitos soportados en el ánodo es una estrategia muy útil para mejorar las propiedades eléctricas de las pilas de combustible de óxido sólido, debido a que permiten disminuir considerablemente el espesor de los electrolitos. Para este trabajo, se han preparado exitosamente pilas de combustible de óxido sólido con electrolitos de ceria dopada con Gd, Ce1-xGdxO2-y (CGO soportados sobre un ánodo formado por un cermet de Ni/CGO. Dichas pilas se han

  14. Organosilicon-Based Electrolytes for Long-Life Lithium Primary Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Fenton, Kyle R. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Nagasubramanian, Ganesan [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Staiger, Chad L. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Pratt, III, Harry D. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Rempe, Susan B. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Leung, Kevin [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Chaudhari, Mangesh I. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Anderson, Travis Mark [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    This report describes advances in electrolytes for lithium primary battery systems. Electrolytes were synthesized that utilize organosilane materials that include anion binding agent functionality. Numerous materials were synthesized and tested in lithium carbon monofluoride battery systems for conductivity, impedance, and capacity. Resulting electrolytes were shown to be completely non-flammable and showed promise as co-solvents for electrolyte systems, due to low dielectric strength.

  15. Inorganic proton conducting electrolyte coupled oxide-based dendritic transistors for synaptic electronics.

    Science.gov (United States)

    Wan, Chang Jin; Zhu, Li Qiang; Zhou, Ju Mei; Shi, Yi; Wan, Qing

    2014-05-07

    Ionic/electronic hybrid devices with synaptic functions are considered to be the essential building blocks for neuromorphic systems and brain-inspired computing. Here, artificial synapses based on indium-zinc-oxide (IZO) transistors gated by nanogranular SiO2 proton-conducting electrolyte films are fabricated on glass substrates. Spike-timing dependent plasticity and paired-pulse facilitation are successfully mimicked in an individual bottom-gate transistor. Most importantly, dynamic logic and dendritic integration established by spatiotemporally correlated spikes are also mimicked in dendritic transistors with two in-plane gates as the presynaptic input terminals.

  16. X-ray diffraction studies of chitosan acetate-based polymer electrolytes

    International Nuclear Information System (INIS)

    Osman, Z.; Ibrahim, Z.A.; Abdul Kariem Arof

    2002-01-01

    Chitosan is the product when partially deacetylated chitin dissolves in dilute acetic acid. This paper presents the x-ray diffraction patterns of chitosan acetate, plasticised chitosan acetate and plasticised-salted chitosan acetate films. The results show that the chitosan acetate based polymer electrolyte films are not completely amorphous but it is partially crystalline. X-ray diffraction study also confirms the occurrence of the complexation between chitosan and the salt and the interaction between salt and plasticizer. The salt-chitosan interaction is clearly justified by infrared spectroscopy. (Author)

  17. Lithium ion conducting biopolymer electrolyte based on pectin doped with Lithium nitrate

    Science.gov (United States)

    Manjuladevi, R.; Selvin, P. Christopher; Selvasekarapandian, S.; Shilpa, R.; Moniha, V.

    2018-04-01

    The Biopolymer electrolyte based on pectin doped with lithium nitrate of different concentrations have been prepared by solution casting technique. The decrease in crystalline nature of the biopolymer has been identified by XRD analyses. The complex formation between the polymer and the salt has been revealed using FTIR analysis. The ionic conductivity has been explored using A.C. impedance spectroscopy which reveals that the biopolymer containing 30 wt% Pectin: 70wt%LiNO3 has highest ionic conductivity of 3.97 × 10-3 Scm-1.

  18. Present status of solid state photoelectrochemical solar cells and dye sensitized solar cells using PEO-based polymer electrolytes

    International Nuclear Information System (INIS)

    Singh, Pramod Kumar; Bhattacharya, Bhaskar; Nagarale, R K; Pandey, S P; Rhee, H W

    2011-01-01

    Due to energy crises in the future, much effort is being directed towards alternate sources. Solar energy is accepted as a novel substitute for conventional sources of energy. Out of the long list of various types of solar cells available on the market, solid state photoelectrochemical solar cells (SSPECs) and dye sensitized solar cells (DSSCs) are proposed as an alternative to costly crystalline solar cell. This review provides a common platform for SSPECs and DSSCs using polymer electrolyte, particularly on polyethylene oxide (PEO)-based polymer electrolytes. Due to numerous advantageous properties of PEO, it is frequently used as an electrolyte in both SSPECs as well as DSSCs. In DSSCs, so far high efficiency (more than 11%) has been obtained only by using volatile liquid electrolyte, which suffers many disadvantages, such as corrosion, leakage and evaporation. The PEO-based solid polymer proves its importance and could be used to solve the problems stated above. The recent developments in SSPECs and DSSCs using modified PEO electrolytes by adding nano size inorganic fillers, blending with low molecular weight polymers and ionic liquid (IL) are discussed in detail. The role of ionic liquid in modifying the electrical, structural and photoelectrochemical properties of PEO polymer electrolytes is also described. (review)

  19. American Society of Nephrology quiz and questionnaire 2014: acid-base and electrolyte disorders.

    Science.gov (United States)

    Rosner, Mitchell H; Perazella, Mark A; Choi, Michael J

    2015-03-06

    The Nephrology Quiz and Questionnaire remains an extremely popular session for attendees of the Annual Kidney Week Meeting of the American Society of Nephrology. Once again, in 2014 the conference hall was overflowing with audience members and eager quiz participants. Topics covered by the expert discussants included electrolyte and acid-base disorders, glomerular disease, ESRD/dialysis, and transplantation. Complex cases from each of these categories along with single-best-answer questions were prepared and submitted by the panel of experts. Before the meeting, program directors of United States nephrology training programs and nephrology fellows answered the questions using an Internet-based questionnaire. During the live session, members of the audience tested their knowledge and judgment on a series of case-oriented questions prepared and discussed by the experts. They compared their answers in real time using audience response devices with the answers of the nephrology fellows and training program directors. The correct and incorrect answers were then discussed after the audience responses and the results of the questionnaire were displayed. As always, the audience, lecturers, and moderators enjoyed this educational session. This article recapitulates the acid-base and electrolyte disorders portion of the session and reproduces its educational value for the readers of the Clinical Journal of the American Society of Nephrology. Enjoy the clinical cases and expert discussions. Copyright © 2015 by the American Society of Nephrology.

  20. Electrochemical energy storage in montmorillonite K10 clay based composite as supercapacitor using ionic liquid electrolyte.

    Science.gov (United States)

    Maiti, Sandipan; Pramanik, Atin; Chattopadhyay, Shreyasi; De, Goutam; Mahanty, Sourindra

    2016-02-15

    Exploring new electrode materials is the key to realize high performance energy storage devices for effective utilization of renewable energy. Natural clays with layered structure and high surface area are prospective materials for electrical double layer capacitors (EDLC). In this work, a novel hybrid composite based on acid-leached montmorillonite (K10), multi-walled carbon nanotube (MWCNT) and manganese dioxide (MnO2) was prepared and its electrochemical properties were investigated by fabricating two-electrode asymmetric supercapacitor cells against activated carbon (AC) using 1.0M tetraethylammonium tetrafluroborate (Et4NBF4) in acetonitrile (AN) as electrolyte. The asymmetric supercapacitors, capable of operating in a wide potential window of 0.0-2.7V, showed a high energy density of 171Whkg(-1) at a power density of ∼1.98kWkg(-1). Such high EDLC performance could possibly be linked to the acid-base interaction of K10 through its surface hydroxyl groups with the tetraethylammonium cation [(C2H5)4N(+) or TEA(+)] of the ionic liquid electrolyte. Even at a very high power density of 96.4kWkg(-1), the cells could still deliver an energy density of 91.1Whkg(-1) exhibiting an outstanding rate capability. The present study demonstrates for the first time, the excellent potential of clay-based composites for high power energy storage device applications. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. A High Temperature Electrochemical Energy Storage System Based on Sodium Beta-Alumina Solid Electrolyte (Base)

    Energy Technology Data Exchange (ETDEWEB)

    Anil Virkar

    2008-03-31

    This report summarizes the work done during the period September 1, 2005 and March 31, 2008. Work was conducted in the following areas: (1) Fabrication of sodium beta{double_prime} alumina solid electrolyte (BASE) using a vapor phase process. (2) Mechanistic studies on the conversion of {alpha}-alumina + zirconia into beta{double_prime}-alumina + zirconia by the vapor phase process. (3) Characterization of BASE by X-ray diffraction, SEM, and conductivity measurements. (4) Design, construction and electrochemical testing of a symmetric cell containing BASE as the electrolyte and NaCl + ZnCl{sub 2} as the electrodes. (5) Design, construction, and electrochemical evaluation of Na/BASE/ZnCl{sub 2} electrochemical cells. (6) Stability studies in ZnCl{sub 2}, SnCl{sub 2}, and SnI{sub 4} (7) Design, assembly and testing of planar stacks. (8) Investigation of the effect of porous surface layers on BASE on cell resistance. The conventional process for the fabrication of sodium ion conducting beta{double_prime}-alumina involves calcination of {alpha}-alumina + Na{sub 2}CO{sub 3} + LiNO{sub 3} at 1250 C, followed by sintering powder compacts in sealed containers (platinum or MgO) at {approx}1600 C. The novel vapor phase process involves first sintering a mixture of {alpha}-alumina + yttria-stabilized zirconia (YSZ) into a dense ceramic followed by exposure to soda vapor at {approx}1450 C to convert {alpha}-alumina into beta{double_prime}-alumina. The vapor phase process leads to a high strength BASE, which is also resistant to moisture attack, unlike BASE made by the conventional process. The PI is the lead inventor of the process. Discs and tubes of BASE were fabricated in the present work. In the conventional process, sintering of BASE is accomplished by a transient liquid phase mechanism wherein the liquid phase contains NaAlO{sub 2}. Some NaAlO{sub 2} continues to remain at grain boundaries; and is the root cause of its water sensitivity. In the vapor phase process, Na

  2. Understanding the thermal instability of fluoroethylene carbonate in LiPF6-based electrolytes for lithium ion batteries

    International Nuclear Information System (INIS)

    Kim, Koeun; Park, Inbok; Ha, Se-Young; Kim, Yeonkyoung; Woo, Myung-Heuio; Jeong, Myung-Hwan; Shin, Woo Cheol; Ue, Makoto; Hong, Sung You; Choi, Nam-Soon

    2017-01-01

    Highlights: • The FEC in LiPF 6 -based electrolytes thermally decomposes at elevated temperatures. • Lewis acids in the electrolyte promote de-fluorination of the FEC to form HF. • The HF causes the SEI destruction and severe metal ion dissolution from the cathode. - Abstract: The cycling and storage performances of LiCoO 2 (LCO)-LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM)/pitch-coated silicon alloy-graphite (Si-C) full cells with ethylene carbonate (EC)–based and fluoroethylene carbonate (FEC)–based electrolytes are investigated at elevated temperatures. Excess FEC (used as a co-solvent in LiPF 6 -based electrolytes), which is not completely consumed during the formation of the solid electrolyte interphase (SEI) layer on the electrodes, is prone to defluorination in the presence of Lewis acids such as PF 5 ; this reaction can generate unwanted HF and various acids (H 3 OPF 6 , HPO 2 F 2 , H 2 PO 3 F, H 3 PO 4 ) at elevated temperatures. Our investigation reveals that the HF and acid compounds that are formed by FEC decomposition causes significant dissolution of transition metal ions (from the LCO-NCM cathode) into the electrolyte at elevated temperatures; as a result, the reversible capacity of the full cells reduces because of the deposition of the dissolved metal ions onto the anode. Moreover, we demonstrate possible mechanisms that account for the thermal instability of FEC in LiPF 6 -based electrolytes at elevated temperatures using model experiments.

  3. Network type sp3 boron-based single-ion conducting polymer electrolytes for lithium ion batteries

    Science.gov (United States)

    Deng, Kuirong; Wang, Shuanjin; Ren, Shan; Han, Dongmei; Xiao, Min; Meng, Yuezhong

    2017-08-01

    Electrolytes play a vital role in modulating lithium ion battery performance. An outstanding electrolyte should possess both high ionic conductivity and unity lithium ion transference number. Here, we present a facile method to fabricate a network type sp3 boron-based single-ion conducting polymer electrolyte (SIPE) with high ionic conductivity and lithium ion transference number approaching unity. The SIPE was synthesized by coupling of lithium bis(allylmalonato)borate (LiBAMB) and pentaerythritol tetrakis(2-mercaptoacetate) (PETMP) via one-step photoinitiated in situ thiol-ene click reaction in plasticizers. Influence of kinds and content of plasticizers was investigated and the optimized electrolytes show both outstanding ionic conductivity (1.47 × 10-3 S cm-1 at 25 °C) and high lithium transference number of 0.89. This ionic conductivity is among the highest ionic conductivity exhibited by SIPEs reported to date. Its electrochemical stability window is up to 5.2 V. More importantly, Li/LiFePO4 cells with the prepared single-ion conducting electrolytes as the electrolyte as well as the separator display highly reversible capacity and excellent rate capacity under room temperature. It also demonstrates excellent long-term stability and reliability as it maintains capacity of 124 mA h g-1 at 1 C rate even after 500 cycles without obvious decay.

  4. A Rechargeable Li-Air Fuel Cell Battery Based on Garnet Solid Electrolytes

    Science.gov (United States)

    Sun, Jiyang; Zhao, Ning; Li, Yiqiu; Guo, Xiangxin; Feng, Xuefei; Liu, Xiaosong; Liu, Zhi; Cui, Guanglei; Zheng, Hao; Gu, Lin; Li, Hong

    2017-01-01

    Non-aqueous Li-air batteries have been intensively studied in the past few years for their theoretically super-high energy density. However, they cannot operate properly in real air because they contain highly unstable and volatile electrolytes. Here, we report the fabrication of solid-state Li-air batteries using garnet (i.e., Li6.4La3Zr1.4Ta0.6O12, LLZTO) ceramic disks with high density and ionic conductivity as the electrolytes and composite cathodes consisting of garnet powder, Li salts (LiTFSI) and active carbon. These batteries run in real air based on the formation and decomposition at least partially of Li2CO3. Batteries with LiTFSI mixed with polyimide (PI:LiTFSI) as a binder show rechargeability at 200 °C with a specific capacity of 2184 mAh g−1carbon at 20 μA cm−2. Replacement of PI:LiTFSI with LiTFSI dissolved in polypropylene carbonate (PPC:LiTFSI) reduces interfacial resistance, and the resulting batteries show a greatly increased discharge capacity of approximately 20300 mAh g−1carbon and cycle 50 times while maintaining a cutoff capacity of 1000 mAh g−1carbon at 20 μA cm−2 and 80 °C. These results demonstrate that the use of LLZTO ceramic electrolytes enables operation of the Li-air battery in real air at medium temperatures, leading to a novel type of Li-air fuel cell battery for energy storage. PMID:28117359

  5. Zirconia based ceramic coating on a metal with plasma electrolytic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Akatsu, T; Shinoda, Y; Wakai, F [Secure Materials Center, Materials and Structures Laboratory, Tokyo Institute of Technology, 4259-R3-24, Nagatsuta, Midori, Yokohama (Japan); Kato, T, E-mail: akatsu.t.aa@m.titech.ac.jp [Department of Materials Science and Engineering, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259-R3-24, Nagatsuta, Midori, Yokohama (Japan)

    2011-10-29

    We challenge to fabricate a thermal barrier coating (TBC) made of ZrO{sub 2} based ceramics on a Ni based single crystal superalloy with plasma electrolytic oxidation (PEO) by incorporating metal species from electrolyte into the coating. The PEO process is carried out on the superalloy galvanized with aluminium for 15min in Na{sub 4}O{sub 7}P{sub 4} solution for an oxygen barrier coating (OBC) and is followed by PEO in K{sub 2}[Zr(CO{sub 3}){sub 2}(OH){sub 2}] solution for TBC. We obtained the following results; (1) Monoclinic-, tetragonal-, cubic-ZrO{sub 2} crystals were detected in TBC. (2) High porosity with large pores was observed near the interface between OBC and TBC. The fine grain structure with a grain size of about 300nm was typically observed. (3) The adhesion strength between PEO coatings and substrate was evaluated to be 26.8{+-}6.6MPa. At the adhesion strength test, PEO coatings fractured around the interface between OBC and TBC. The effect of coating structure on adhesion strength is explained through the change in spark discharge during PEO process.

  6. Demonstration of high efficiency intermediate-temperature solid oxide fuel cell based on lanthanum gallate electrolyte

    International Nuclear Information System (INIS)

    Inagaki, Toru; Nishiwaki, Futoshi; Kanou, Jirou; Yamasaki, Satoru; Hosoi, Kei; Miyazawa, Takashi; Yamada, Masaharu; Komada, Norikazu

    2006-01-01

    The Kansai Electric Power Co., Inc. (KEPCO) and Mitsubishi Materials Corporation (MMC) have been jointly developing intermediate-temperature solid oxide fuel cells (SOFCs). The operation temperatures between 600 and 800 o C were set as the target, which enable SOFC to use less expensive metallic separators for cell-stacking and to carry out internal reforming of hydrocarbon fuels. The electrolyte-supported planar-type cells were fabricated using highly conductive lanthanum gallate-based electrolyte, La(Sr)Ga(Mg,Co)O 3-δ , Ni-(CeO 2 ) 1-x (SmO 1.5 ) x cermet anode, and Sm(Sr)CoO 3-δ cathode. The 1 kW-class power generation modules were fabricated using a seal-less stack of the cells and metallic separators. The 1 kW-class prototype power generation system with the module was developed with the high performance cell, which showed the thermally self-sustainability. The system included an SOFC module, a dc-ac inverter, a desulfurizer, and a heat recovery unit. It provided stable ac power output of 1 kW with the electrical efficiency of 45% LHV based on ac output by using city gas as a fuel, which was considered to be excellent for such a small power generation system. And the hot water of 90 o C was obtained using high temperature off-gas from SOFC

  7. High-Efficiency Glass and Printable Flexible Dye-Sensitized Solar Cells with Water-Based Electrolytes

    Directory of Open Access Journals (Sweden)

    Omar Moudam

    2014-01-01

    Full Text Available The performance of a flexible and glass dye-sensitized solar cell (DSSC with water-based electrolyte solutions is described. High concentrations of alkylamidazoliums were used to overcome the deleterious effect of water and, based on this variable, pure water-based electrolyte DSSCs were tested displaying the highest recorded efficiency so far of 3.45% and 6% for flexible and glass cells, respectively, under a simulated air mass 1.5 solar spectrum illumination at 100 mWcm−2. An improvement in the Jsc with high water content and the positive impact of GuSCN on the enhancement of the performance of pure water-based electrolytes were also observed.

  8. Battery electrolytes based on saturated ring ionic liquids: Physical and electrochemical properties

    International Nuclear Information System (INIS)

    Di Leo, Roberta A.; Marschilok, Amy C.; Takeuchi, Kenneth J.; Takeuchi, Esther S.

    2013-01-01

    Physical and electrochemical properties of mixtures of ionic liquids based on saturated ring systems with carbonate based solvents were investigated. The conductivity and electrochemical stability of two series of ionic liquids based on piperidinium and pyrrolidinium cations with tetrafluoroborate and bis(trifluorosulfonylimide) anions were evaluated. The effects of the ionic liquid cation, substituent chain length of the cation function group, and the anion type on conductivity and electrochemical stability as determined by cyclic voltammetry were studied. The conductivity was influenced by the substituent chain length of the ionic liquid cation and the solvent carbonate type, where higher conductivities were observed with shorter substituent chains and EC versus PC. The saturated ring ionic liquid–carbonate mixtures may show particular promise for implementation as battery electrolytes due to notable high voltage stabilities, where stability >5.5 V was maintained in the presence of lithium salt. This study should promote development of future safe, high voltage lithium ion battery systems

  9. Alkali Influence on Synthesis of Solid Electrolyte Based on Alkali Nitrate-Alumina

    International Nuclear Information System (INIS)

    Yustinus Purwamargapratala; Purnama, S.; Purwanto, P.

    2008-01-01

    Research of solid electrolyte based on alumina with addition of alkali materials of barium nitrate, calcium nitrate, sodium nitrate and lithium nitrate has been done. Aluminium hydroxide and alkali nitrate were mixed in mole ratio of 1 : 1 in water media and pyrolyzed at 300 o C for 1 hour Pyrolysis result were then mixed with alumina in mole ratio of 1 : 1, compacted and heated at 600 o C for 3 hours. To characterize the sample, XRD (X-Ray Diffractometers) and LCR meter (impedance, capacitance, and resistance) were used for analysis the phase and conductivity properties. The result showed formation of alkali-aluminate in which Li-base have the highest room temperature conductivity of 3.1290 x 10 -5 S.cm -1 , while Ba-base have the lowest conductivity of 5.7266 x 10 -8 S.cm -1 . (author)

  10. FT-IR studies on interactions among components in hexanoyl chitosan-based polymer electrolytes

    Science.gov (United States)

    Winie, Tan; Arof, A. K.

    2006-03-01

    Fourier transform infrared (FT-IR) spectroscopic studies have been undertaken to investigate the interactions among components in a system of hexanoyl chitosan-lithium trifluoromethanesulfonate (LiCF 3SO 3)-diethyl carbonate (DEC)/ethylene carbonate (EC). LiCF 3SO 3 interacts with the hexanoyl chitosan to form a hexanoyl chitosan-salt complex that results in the shifting of the N(COR) 2, C dbnd O sbnd NHR and OCOR bands to lower wavenumbers. Interactions between EC and DEC with LiCF 3SO 3 has been noted and discussed. Evidence of interaction between EC and DEC has been obtained experimentally. Studies on polymer-plasticizer spectra suggested that there is no interaction between the polymer host and plasticizers. Competition between plasticizer and polymer on associating with Li + ions was observed from the spectral data for gel polymer electrolytes. The obtained spectroscopic data has been correlated with the conductivity performance of hexanoyl chitosan-based polymer electrolytes.

  11. Electrochemical oxidation of organic carbonate based electrolyte solutions at lithium metal oxide electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Imhof, R.; Novak, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The oxidative decomposition of carbonate based electrolyte solutions at practical lithium metal oxide composite electrodes was studied by differential electrochemical mass spectrometry. For propylene carbonate (PC), CO{sub 2} evolution was detected at LiNiO{sub 2}, LiCoO{sub 2}, and LiMn{sub 2}O{sub 4} composite electrodes. The starting point of gas evolution was 4.2 V vs. Li/Li{sup +} at LiNiO{sub 2}, whereas at LiCoO{sub 2} and LiMn{sub 2}O{sub 4}, CO{sub 2} evolution was only observed above 4.8 V vs. Li/Li{sup +}. In addition, various other volatile electrolyte decomposition products of PC were detected when using LiCoO{sub 2}, LiMn{sub 2}O4, and carbon black electrodes. In ethylene carbonate / dimethyl carbonate, CO{sub 2} evolution was only detected at LiNiO{sub 2} electrodes, again starting at about 4.2 V vs. Li/Li{sup +}. (author) 3 figs., 2 refs.

  12. The Solubility of Aluminum in Cryolite-Based Electrolyte-Containing KF

    Science.gov (United States)

    Zhang, Yu; Yu, Jiangyu; Gao, Bingliang; Liu, Yibai; Hu, Xianwei; Shi, Zhongning; Wang, Zhaowen

    2016-04-01

    The solubility of aluminum in NaF-AlF3-CaF2-KF-A12O3 electrolyte system at 1253 K (980 °C) has been measured by the analysis of quenched samples saturated with aluminum. The content of the dissolved metal in the quenched melt was determined by collecting the volume of hydrogen gas when a finely crushed sample is treated with HCl. Addition of 0 to 5 pct KF has no obvious effect on the solubility of aluminum in cryolite-based melts with molar ratio of NaF/AlF3 (cryolite ratio) ranging from 2.2 to 3.0. The solubility of aluminum increases from 0.015 to 0.026 wt pct with cryolite ratio increases from 2.2 to 4.0 in the NaF-AlF3-5 wt pct CaF2-3 wt pct A12O3 electrolyte at 1253 K (980 °C). Aluminum solubility was affected by both chemical replacement reaction of Al + 3NaF = AlF3 + 3Na and physical dissolution.

  13. An Investigation on the Properties of Palm-Based Polyurethane Solid Polymer Electrolyte

    Directory of Open Access Journals (Sweden)

    Farah Nadia Daud

    2014-01-01

    Full Text Available Palm-based polyurethane electrolyte was prepared via prepolymerization method between palm kernel oil polyol (PKO-p and 2,4′-diphenylmethane diisocyanate (MDI in acetone at room temperature with the presence of lithium trifluoromethanesulfonate (LiCF3SO3. The effect of varying the concentration of LiCF3SO3 salt on the ionic conductivity, chemical interaction, and structural and morphological properties of the polyurethane solid polymer electrolyte was investigated. The produced film was analyzed using electrochemical impedance spectroscopy (EIS, attenuated total reflection Fourier transform infrared (ATR-FTIR, X-ray diffraction (XRD, and scanning electron microscopy (SEM. The EIS result showed that the highest ionic conductivity was at 30 wt% LiCF3SO3 with a value of 1.6 × 10−5 S·cm−1. Infrared analysis showed the interaction between lithium ions and amine group (–N–H at (3600–3100 cm−1, carbonyl group (–C=O at (1750–1650 cm−1, and ether group (–C–O–C– at (1150–1000 cm−1 of the polyurethane forming polymer-salt complexes. The XRD result proved that LiCF3SO3 salt completely dissociates within the polyurethane film as no crystalline peaks of LiCF3SO3 were observed. The morphological study revealed that the films prepared have a good homogeneity and compatibility as no phase separation occurred.

  14. Studies on MgNi-Based Metal Hydride Electrode with Aqueous Electrolytes Composed of Various Hydroxides

    Directory of Open Access Journals (Sweden)

    Jean Nei

    2016-08-01

    Full Text Available Compositions of MgNi-based amorphous-monocrystalline thin films produced by radio frequency (RF sputtering with a varying composition target have been optimized. The composition Mg52Ni39Co3Mn6 is identified to possess the highest initial discharge capacity of 640 mAh·g−1 with a 50 mA·g−1 discharge current density. Reproduction in bulk form of Mg52Ni39Co3Mn6 alloy composition was prepared through a combination of melt spinning (MS and mechanical alloying (MA, shows a sponge-like microstructure with >95% amorphous content, and is chosen as the metal hydride (MH alloy for a sequence of electrolyte experiments with various hydroxides including LiOH, NaOH, KOH, RbOH, CsOH, and (C2H54N(OH. The electrolyte conductivity is found to be closely related to cation size in the hydroxide compound used as 1 M additive to the 4 M KOH aqueous solution. The degradation performance of Mg52Ni39Co3Mn6 alloy through cycling demonstrates a strong correlation with the redox potential of the cation in the alkali hydroxide compound used as 1 M additive to the 5 M KOH aqueous solution. NaOH, CsOH, and (C2H54N(OH additions are found to achieve a good balance between corrosion and conductivity performances.

  15. Enhancement of Oxygen Reduction and Mitigation of Ionomer Dry-Out Using Insoluble Heteropoly Acids in Intermediate Temperature Polymer-Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Alessandro Stassi

    2015-07-01

    Full Text Available The use of Cs0.5H0.5PW12O40 insoluble salt as a superacid promoter in the catalyst layer of a polymer electrolyte membrane fuel cell (PEMFC has been investigated. An increase of performance has been recorded at intermediate temperatures (110–130 °C and under low relative humidity (R.H.. The promoter appears to mitigate the ionomer dry-out effects in the catalytic layer and produces an increase of the extent of the catalyst-electrolyte interface as demonstrated by cyclic voltammetry analysis. These effects are also corroborated by a significant decrease of polarization resistance at intermediate temperatures. Such characteristics have been demonstrated for a conventional membrane-electrode assembly based on a Pt-Co alloy and a Nafion 115 membrane.

  16. Bis(fluoromalonato)borate (BFMB) anion based ionic liquid as an additive for lithium-ion battery electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xiao-Guang [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciencese Division; Liao, Chen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciencese Division; Baggetto, Loïc [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Guo, Bingkun [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciencese Division; Unocic, Raymond R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science; Veith, Gabriel M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Dai, Sheng [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciencese Division; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry

    2014-02-21

    Propylene carbonate (PC) is a good solvent for lithium ion battery applications due to its low melting point and high dielectric constant. But, PC is easily intercalated into graphite causing it to exfoliate, killing its electrochemical performance. We report on the synthesis of a new ionic liquid electrolyte based on partially fluorinated borate anion, 1-butyl-1,2-dimethylimidazolium bis(fluoromalonato)borate (BDMIm.BFMB), which can be used as an additive in 1 M LiPF6/PC electrolyte to suppress graphite exfoliation and improve cycling performance. Additionally, both PC and BDMIm.BFMB can be used synergistically as additive to 1.0M LiPF6/methyl isopropyl sulfone (MIPS) to dramatically improve its cycling performance. It is also found that the chemistry nature of the ionic liquids has dramatic effect on their role as additive in PC based electrolyte.

  17. Lithium Polymer Electrolytes Based On PMMA / PEG And Penetrant Diffusion In Kraton Penta-Block Ionomer

    Science.gov (United States)

    Meng, Yan

    The study of diffusion in polymeric material is critical to many research fields and applications, such as polymer morphology, protective coatings (paints and varnishes), separation membranes, transport phenomena, polymer electrolytes, polymer melt, and controlled release of drugs from polymer carriers [1-9]. However, it is still a challenge to understand, predict and control the diffusion of molecules and ions of different sizes in polymers [2]. This work studied the medium to long range diffusion of species (i.e., ions and molecules) in solid polymer electrolytes based on poly(ethylene glycol)/poly(methyl methacrylate) (PEG/PMMA) for Li-based batteries, and polymeric permselective membranes via pulsed-field gradient NMR and a.c. impedance. Over the past decades polymer electrolytes have attracted much attention because of their promising technological application as an ion-conducting medium in solid-state batteries, fuel cells, electrochromic displays, and chemical sensors [10, 11]. However, despite numerous studies related to ionic transport in these electrolytes the understanding of the migration mechanism is still far from being complete, and progress in the field remains largely empirical [10, 12-15]. Among various candidates for solid polymer electrolyte (SPE) material, the miscible polymer pair, poly(ethylene oxide)/poly(methyl methacrylate) (PEO/PMMA), is an attractive one, because there is a huge difference in mobility between PEO and PMMA in their blends, and PEO chains remain exceptionally mobile in the blend even at temperature below the glass transition temperature of the blend [ 16]. Thus the mechanical strength and dimensional stability is maintained by PMMA component, while the chain motions or rearrangements of the PEO component virtually contribute to the ion transport [17]. The current work prepared two types of SPE based on poly(ethylene glycol) (PEG) /PMMA (40/60 by weight) for Li-based batteries: lithium bis(trifluoromethylsulfonylimide) (Li

  18. Physics Based Electrolytic Capacitor Degradation Models for Prognostic Studies under Thermal Overstress

    Science.gov (United States)

    Kulkarni, Chetan S.; Celaya, Jose R.; Goebel, Kai; Biswas, Gautam

    2012-01-01

    Electrolytic capacitors are used in several applications ranging from power supplies on safety critical avionics equipment to power drivers for electro-mechanical actuators. This makes them good candidates for prognostics and health management research. Prognostics provides a way to assess remaining useful life of components or systems based on their current state of health and their anticipated future use and operational conditions. Past experiences show that capacitors tend to degrade and fail faster under high electrical and thermal stress conditions that they are often subjected to during operations. In this work, we study the effects of accelerated aging due to thermal stress on different sets of capacitors under different conditions. Our focus is on deriving first principles degradation models for thermal stress conditions. Data collected from simultaneous experiments are used to validate the desired models. Our overall goal is to derive accurate models of capacitor degradation, and use them to predict performance changes in DC-DC converters.

  19. Electrodeposition fabrication of Co-based superhydrophobic powder coatings in non-aqueous electrolyte

    Science.gov (United States)

    Chen, Zhi; Hao, Limei; Duan, Mengmeng; Chen, Changle

    2013-05-01

    A rapid, facile, one-step process was developed to fabricate Co-based superhydrophobic powder coatings on the stainless steel surfaces with a nonaqueous electrolyte by the electrodeposition method. The structure and composition of the superhydrophobic surfaces were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and contact angle measurement. The results show that the special hierarchical structures along with the low surface energy lead to the high superhydrophobicity of the substrate surface. The shortest process of constructing the superhydrophobic surface is only 30 seconds, the high contact angle is greater than 160°, and the rolling angle is less than 2°. The method can be used to fabricate the superhydrophobic powder coatings at any conductive cathodic surface, and the as-prepared superhydrophobic powder coatings have advantages of transferability, repairability, and durability. It is expected that this facile method will accelerate the large-scale production of superhydrophobic material.

  20. Improved performance and safety of lithium ion cells with the use of fluorinated carbonate-based electrolytes

    Science.gov (United States)

    Smart, M. C.; Ratnakumar, B. V.; Ryan, V. S.; Surampudi, S.; Prakashi, G. K. S.; Hu, J.; Cheung, I.

    2002-01-01

    There has been increasing interest in developing lithium-ion electrolytes that possess enhanced safety characteristics, while still able to provide the desired stability and performance. Toward this end, our efforts have been focused on the development of lithium-ion electrolytes which contain partially and fully fluorinated carbonate solvents. The advantage of using such solvents is that they possess the requisite stability demonstrated by the hydrocarbon-based carbonates, while also possessing more desirable physical properties imparted by the presence of the fluorine substituents, such as lower melting points, increased stability toward oxidation, and favorable SEI film forming Characteristics on carbon. Specifically, we have demonstrated the beneficial effect of electrolytes which contain the following fluorinated carbonate-based solvents: methyl 2,2,2-trifluoroethyl carbonate (MTFEC), ethyl-2,2,2 trifluoroethyl carbonate (ETFEC), propyl 2,2,2-trifluoroethyl carbonate (PTFEC), methyl-2,2,2,2',2',2' -hexafluoro-i-propyl carbonate (MHFPC), ethyl- 2,2,2,2',2',2' -hexafluoro-i-propyl carbonate (EHFPC), and di-2,2,2-trifluoroethyl carbonate (DTFEC). These solvents have been incorporated into multi-component ternary and quaternary carbonate-based electrolytes and evaluated in lithium-carbon and carbon-LiNio.8Coo.202 cells (equipped with lithium reference electrodes). In addition to determining the charge/discharge behavior of these cells, a number of electrochemical techniques were employed (i.e., Tafel polarization measurements, linear polarization measurements, and electrochemical impedance spectroscopy (EIS)) to further characterize the performance of these electrolytes, including the SEI formation characteristics and lithium intercalatiodde-intercalation kinetics. In addition to their evaluation in experimental cells, cyclic voltammetry (CV) and conductivity measurements were performed on select electrolyte formulations to further our understanding of the trends

  1. Hybrid electrolytes based on ionic liquids and amorphous porous silicon nanoparticles: Organization and electrochemical properties

    KAUST Repository

    Tchalala, Mohammed

    2017-05-06

    Ionic liquids (ILs) and ionic liquid-nanoparticle (IL-NP) hybrid electrolytes have garnered a lot of interest due to their unique properties that stimulate their use in various applications. Herein, we investigate the electrochemical and photo-physical properties of organic-inorganic hybrid electrolytes based on three imidazolium-based ionic liquids, i.e., 1-buthyl-3-methylimidazolium thiocyanate ([bmim] [SCN]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim] [BF4]) and 1-buthyl-3-methylimidazolium acetate ([bmim] [Ac]) that are covalently tethered to amorphous porous silicon nanoparticles (ap-Si NPs). We found that the addition of ap-Si NPs confer to the ILs a pronounced boost in the electrocatalytic activity, and in mixtures of ap-Si NPs and [bmim] [SCN], the room-temperature current transport is enhanced by more than 5 times compared to bare [bmim] [SCN]. A detailed structural investigation by transmission electron microscope (TEM) showed that the ap-Si NPs were well dispersed, stabilized and highly aggregated in [bmim] [SCN], [emim] [BF4] and [bmim] [Ac] ILs, respectively. These observations correlate well with the enhanced current transport observed in ap-Si NPs/[bmim] [SCN] evidenced by electrochemical measurements. We interpreted these observations by the use of UV–vis absorbance, photoluminescence (PL), FTIR and solid-state NMR spectroscopy. We found that the ap-Si NPs/[bmim] [SCN] hybrid stands out due to its stability and optical transparency. This behavior is attributed to the iron(III) thiocyanate complexion as per the experimental findings. Furthermore, we found that the addition of NPs to [emim] [BF4] alters the equilibrium of the IL, which consequently improved the stability of the NPs through intermolecular interactions with the two ionic layers (anionic and cationic layers) of the IL. While in the case of [bmim] [Ac], the dispersion of ap-Si NPs was restrained because of the high viscosity of this IL.

  2. Improved low temperature performance of lithium ion cells with quaternary carbonate-based electrolytes

    Science.gov (United States)

    Smart, M. C.; Ratnakumar, B. V.; Whitcanack, L. D.; Chin, K. B.; Surampudi, S.; Croft, H.; Tice, D.; Staniewicz, R.

    2002-01-01

    In order to enable future missions involving the exploration of the surface of Mars with Landers and Rovers, NASA desires long life, high energy density rechargeable batteries which can operate well at very low temperature (down to 40(deg)C). Lithium-ion technology has been identified as being the most promising chemistry, due to high gravimetric and volumetric energy densities, as well as, long life characteristics. However, the state-of-art (SOA) technology is not sufficient to meet the needs of many applications that require excellent low temperature capabilities. To further improve this technology, work at JF'L has been focused upon developing electrolytes that result in lithium-ion cells with wider temperature ranges of operation. These efforts have led to the identification of a number of ternary and quaternary, all carbonate-based electrolytes that have been demonstrated to result in improved low temperature performance in experimental three-electrode MCMB carbon/LiNio.sCoo.zOz cells. A number of electrochemical characterization techniques were performed on these cells (i.e., Tafel polarization measurements, linear polarization measurements, and electrochemical impedance spectroscopy (EIS)) to further enhance our understanding of the performance limitations at low temperature. The most promising electrolyte formulations, namely 1 .O M LiPF6EC+DEC+DMC+EMC (1 : 1: 1 :2 v/v) and 1 .O M LiPF6 EC+DEC+DMC+EMC (1 : 1 : 1 :3 v/v), were incorporated into SAFT prototype DD-size (9 Ahr) lithium- cells for evaluation. A number of electrical tests were performed on these cells, including rate characterization as a function of temperature, cycle life characterization at different temperatures, as well as, many mission specific characterization test to determine their viability to enable future missions to Mars. Excellent performance was observed with the prototype DD-size cells over a wide temperature range (-50 to 4OoC), with high specific energy being delivered at very

  3. Methyl phosphate formation as a major degradation mode of direct methanol fuel cells with phosphoric acid based electrolytes

    DEFF Research Database (Denmark)

    Aili, David; Vassiliev, Anton; Jensen, Jens Oluf

    2015-01-01

    Phosphoric acid and phosphoric acid doped polymer membranes are widely used as electrolytes in hydrogen based fuel cells operating at elevated temperatures. Such electrolytes have been explored for direct oxidation of methanol to further increase the versatility of the systems, however......, with demonstrated lifetimes of only a few days to weeks. In this work the methyl phosphate formation from the acid and methanol is identified and proposed to be a major mechanism for the cell degradation. Proton conductivity and fuel cell durability tests validate the mechanism at high methanol contents....

  4. All-solid-state lithium-sulfur battery based on a nanoconfined LiBH4 electrolyte

    DEFF Research Database (Denmark)

    Das, Supti; Ngene, Peter; Norby, Poul

    2016-01-01

    In this work we characterize all-solid-state lithium-sulfur batteries based on nano-confined LiBH4 in mesoporous silica as solid electrolytes. The nano-confined LiBH4 has fast ionic lithium conductivity at room temperature, 0.1 mScm-1, negligible electronic conductivity and its cationic transport...... number (t+ = 0.96), close to unity, demonstrates a purely cationic conductor. The electrolyte has an excellent stability against lithium metal. The behavior of the batteries is studied by cyclic voltammetry and repeated charge/discharge cycles in galvanostatic conditions. The batteries show very good...

  5. Effects of electrolyte, catalyst, and membrane composition and operating conditions on the performance of solar-driven electrochemical reduction of carbon dioxide.

    Science.gov (United States)

    Singh, Meenesh R; Clark, Ezra L; Bell, Alexis T

    2015-07-15

    Solar-driven electrochemical cells can be used to convert carbon dioxide, water, and sunlight into transportation fuels or into precursors to such fuels. The voltage efficiency of such devices depends on the (i) physical properties of its components (catalysts, electrolyte, and membrane); (ii) operating conditions (carbon dioxide flowrate and pressure, current density); and (iii) physical dimensions of the cell. The sources of energy loss in a carbon dioxide reduction (CO2R) cell are the anode and cathode overpotentials, the difference in pH between the anode and cathode, the difference in the partial pressure of carbon dioxide between the bulk electrolyte and the cathode, the ohmic loss across the electrolyte and the diffusional resistances across the boundary layers near the electrodes. In this study, we analyze the effects of these losses and propose optimal device configurations for the efficient operation of a CO2R electrochemical cell operating at a current density of 10 mA cm(-2). Cell operation at near-neutral bulk pH offers not only lower polarization losses but also better selectivity to CO2R versus hydrogen evolution. Addition of supporting electrolyte to increase its conductivity has a negative impact on cell performance because it reduces the electric field and the solubility of CO2. Addition of a pH buffer reduces the polarization losses but may affect catalyst selectivity. The carbon dioxide flowrate and partial pressure can have severe effects on the cell efficiency if the carbon dioxide supply rate falls below the consumption rate. The overall potential losses can be reduced by use of an anion, rather than a cation, exchange membrane. We also show that the maximum polarization losses occur for the electrochemical synthesis of CO and that such losses are lower for the synthesis of products requiring a larger number of electrons per molecule, assuming a fixed current density. We also find that the reported electrocatalytic activity of copper below -1

  6. Investigation of ionic conduction in PEO-PVDF based blend polymer electrolytes

    Science.gov (United States)

    Patla, Subir Kumar; Ray, Ruma; Asokan, K.; Karmakar, Sanat

    2018-03-01

    We investigate the effect of blend host polymer on solid polymer electrolyte (SPE) films doped with ammonium iodide (NH4I) salt using a variety of experimental techniques. Structural studies on the composite SPEs show that the blending of Poly(ethylene oxide) (PEO)-Poly(vinylidene fluoride) (PVDF) polymers in a suitable ratio enhances the amorphous fraction of the polymer matrix and facilitates fast ion conduction through it. We observe that the addition of a small amount of PVDF in the PEO host polymer enhances the ion - polymer interaction leading to more ion dissociation. As a result, the effective number of mobile charge carriers within the polymer matrix increases. Systematic investigation in these blend SPEs shows that the maximum conductivity (1.01 × 10-3 S/cm) is obtained for PEO - rich (80 wt. % PEO, 20 wt. % PVDF) composites at 35 wt. % NH4I concentration at room temperature. Interestingly, at higher salt concentrations (above 35 wt. %), the conductivity is found to decrease in this system. The reduction of conductivity at higher salt concentrations is the consequence of decrease in the carrier concentration due to the formation of an ion pair and ion aggregates. PVDF-rich compositions (20 wt. % PEO and 80 wt. % PVDF), on the other hand, show a very complex porous microstructure. We also observe a much lower ionic conductivity (maximum ˜ 10-6 S/cm at 15 wt. % salt) in these composite systems relative to PEO-rich composites.

  7. Impact of Electrolytes Based on Different Solvents on the Long Term Stability of Dye Sensitized Solar Cells

    International Nuclear Information System (INIS)

    Mohanty, Shyama Prasad; Bhargava, Parag

    2015-01-01

    Highlights: •Aging studies were carried out under heat (60 °C) and illumination with DSSCs. •DSSCs with MPN, PC and GBL showed decrease in performance over 60 days. •With NMP, increase in J SC and efficiency was observed whereas V OC decreased. •Leaching of Zn 2+ from sealant and desorption of NMP from TiO 2 are possible causes. -- Abstract: The present article demonstrates the effect of different solvents used in the preparation of electrolyte on the photoelectrochemical characteristics of dye sensitized solar cells (DSSCs) aged under heat (60 °C) and illumination for 60 days. The study has been carried out with four different solvents: 3-methoxypropionitrile (MPN), N-methyl-2-pyrrolidone (NMP), propylene carbonate (PC) and γ-butyrolactone (GBL) which differ in terms of donor number, viscosity and dielectric constant. For DSSCs with electrolytes based on MPN, PC and GBL as solvents, performance decreases with time. In contrast, for DSSC with NMP as solvent in electrolyte, increase in J SC and hence, efficiency up to 15 days has been observed followed by a gradual decrease, but remaining above its initial value after 60 days. However, V OC of such cell decreases with time. There are two possible causes for the above observations. Desorption of NMP molecules from titania surface occurred with aging. Secondly, zinc ions leached into the electrolyte following reaction of NMP with sealant were adsorbed on titania surface. The causes behind aging behavior of cells prepared with different solvent based electrolytes have been analyzed using electrochemical impedance analysis of DSSCs, energy-dispersive X-ray spectroscopy (EDS) of photoanodes and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) of electrolyte containing sealant sample which had also undergone aging under similar condition

  8. Plasma-based radar cross section reduction

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2016-01-01

    This book presents a comprehensive review of plasma-based stealth, covering the basics, methods, parametric analysis, and challenges towards the realization of the idea. The concealment of aircraft from radar sources, or stealth, is achieved through shaping, radar absorbing coatings, engineered materials, or plasma, etc. Plasma-based stealth is a radar cross section (RCS) reduction technique associated with the reflection and absorption of incident electromagnetic (EM) waves by the plasma layer surrounding the structure. A plasma cloud covering the aircraft may give rise to other signatures such as thermal, acoustic, infrared, or visual. Thus it is a matter of concern that the RCS reduction by plasma enhances its detectability due to other signatures. This needs a careful approach towards the plasma generation and its EM wave interaction. The book starts with the basics of EM wave interactions with plasma, briefly discuss the methods used to analyze the propagation characteristics of plasma, and its generatio...

  9. Mixed projection pursuit-based dimensionality reduction

    Science.gov (United States)

    Safavi, Haleh; Chang, Chein-I.

    2009-05-01

    Projection Pursuit (PP) is a component transform technique which seeks a component whose projection vector points to a direction of interestingness in data space which can be specified by a Projection Index (PI). Two most popular component analysis-based techniques, Principal Components Analysis (PCA), Independent Component Analysis (ICA) can be considered as special cases with their PIs specified by data variance and statistical independency respectively. Despite the fact that various component analysis-based techniques have been used for Dimensionality Reduction (DR) the components are generally generated by a specific technique. Even in the case of PP, the same PI has been used to generate project components. This paper explores the utility of PP in DR where various projection indexes are used for DR in context of PP. It further lays out a general setting for PP-based DR and develops algorithms to perform one dimension reduction at a time by using different PIs. In order to substantiate our findings, experiments are conducted to demonstrate advantages of the PP with mixed PIs-based DR over traditional PCA-based, ICA-based and PP-based DR techniques.

  10. Incomplete Pivoted QR-based Dimensionality Reduction

    OpenAIRE

    Bermanis, Amit; Rotbart, Aviv; Salhov, Moshe; Averbuch, Amir

    2016-01-01

    High-dimensional big data appears in many research fields such as image recognition, biology and collaborative filtering. Often, the exploration of such data by classic algorithms is encountered with difficulties due to `curse of dimensionality' phenomenon. Therefore, dimensionality reduction methods are applied to the data prior to its analysis. Many of these methods are based on principal components analysis, which is statistically driven, namely they map the data into a low-dimension subsp...

  11. In-situ Fabrication of a Freestanding Acrylate-based Hierarchical Electrolyte for Lithium-sulfur Batteries

    International Nuclear Information System (INIS)

    Liu, M.; Jiang, H.R.; Ren, Y.X.; Zhou, D.; Kang, F.Y.; Zhao, T.S.

    2016-01-01

    Graphical abstract: We present a freestanding acrylate-based hierarchical electrolyte. This quasi-solid electrolyte is assembled by in-situ gelation of a pentaerythritol tetraacrylate (PETEA)-based gel polymer electrolyte (GPE) into a polymethyl methacrylate (PMMA)-based electrospun network. The prepared polymer battery renders a suppressed shuttle effect and much enhanced cycle life. - Highlights: • A freestanding Acrylate-based Hierarchical Electrolyte was in-situ crafted. • The high conductivity is due to strong uptake ability and elimination of separator. • The polymer battery renders a superior high rate capability and excellent retention. • First-principle calculations prove anchoring ability of ester functional groups. • Cell modeling shows geometric design effectively suppresses polysulfide flux. - Abstract: A number of methods have been attempted to suppress the shuttle effect in lithium-sulfur (Li-S) batteries to improve battery performance. Conventional methods, however, reduce the ionic conductivity, sacrifice the overall energy density and increase the cost of production. Here, we report a facile synthesis of an acrylate-based hierarchical electrolyte (AHE). This quasi-solid electrolyte is assembled by in-situ gelation of a pentaerythritol tetraacrylate (PETEA)-based gel polymer electrolyte (GPE) into a polymethyl methacrylate (PMMA)-based electrospun network. The structural similarity and synergetic compatibility between the electrospun network and GPE provide the AHE an ester-rich robust structure with a high ionic conductivity of 1.02 × 10 −3 S cm −1 due to the strong uptake ability and the elimination of commercial separator. The S/AHE/Li polymer battery also renders a high rate capability of 645 mAh g −1 at 3C, while maintaining excellent retention at both high and low current densities (80.3% after 500 cycles at 0.3C and 91.9% after 500 cycles at 3C). First-principle calculations reveal that the reduced shuttle effect can be

  12. Acid base, electrolyte, glucose, and lactate values during cardiopulmonary resuscitation in dogs and cats.

    Science.gov (United States)

    Hopper, Kate; Borchers, Angela; Epstein, Steven E

    2014-01-01

    To report acid base, electrolyte, glucose, and lactate values collected during or immediately after cardiopulmonary resuscitation (CPR) in dogs and cats. Retrospective study. University Teaching Hospital. Thirty-two dogs and 10 cats. None. Blood gas, electrolyte, glucose, and lactate values measured during CPR or within 5 minutes of return of spontaneous circulation (ROSC) were retrospectively evaluated. The time of blood collection with respect to the occurrence of cardiopulmonary arrest (CPA), the initiation of CPR or ROSC was noted. Forty-two venous blood samples were analyzed, 24 collected during CPR and 18 samples were collected within 5 minutes of ROSC. Metabolic acidosis and hyperlactatemia were evident in all samples in the study while an increased PvCO2 occurred in 88% of samples collected during CPR and in 61% of samples collected following ROSC. Hyperkalemia occurred in 65% of all cases, decreased ionized calcium was evident in 18%, hypoglycemia was evident in 21% while hyperglycemia was evident in 62%. There was no significant difference in any parameter evaluated between dogs and cats during CPR. There was no significant difference of any variable measured during the first 15 minutes of CPA versus those measured more than 15 minutes following CPA. When the values measured during the first 5 minutes of ROSC were compared to those measured during CPR, the pH and PvO2 were significantly lower in the CPR group. Biochemical abnormalities including metabolic acidosis, hyperkalemia, ionized hypocalcemia, hypoglycemia, and hyperglycemia can be identified during CPR and immediately following ROSC. The therapeutic and prognostic relevance of these changes are yet to be defined and may prove to be useful to guide patient management in the future. © Veterinary Emergency and Critical Care Society 2014.

  13. Photoluminescent polymer electrolyte based on agar and containing europium picrate for electrochemical devices

    International Nuclear Information System (INIS)

    Lima, E.; Raphael, E.; Sentanin, F.; Rodrigues, L.C.; Ferreira, R.A.S.; Carlos, L.D.; Silva, M.M.; Pawlicka, A.

    2012-01-01

    Highlights: ► We prepared ionic conducting membranes for the specific requirements of the device. ► Luminescent reporter groups, with many applications in biotechnology. ► Thermal and electrochemical stability of electrolytes is adequate for application. - Abstract: Dispersion of photoluminescent rare earth metal complexes in polymer matrices is of great interest due to the possibility of avoiding the saturation of the photoluminescent signal. The possibility of using a natural ionic conducting polymer matrix was investigated in this study. Samples of agar-based electrolytes containing europium picrate were prepared and characterized by physical and chemical analyses. The FTIR spectra indicated strong interaction of agar O-H and 3,6-anhydro-galactose C-O groups with glycerol and europium picrate. The DSC analyses revealed no glass transition temperature of the samples in the −60 to 250 °C range. From the thermogravimetry (TG), a thermal stability of the samples of up to 180 °C was stated. The membranes were subjected to ionic conductivity measurement, which provided the values of 2.6 × 10 −6 S/cm for the samples with acetic acid and 1.6 × 10 −5 S/cm for the samples without acetic acid. Moreover, the temperature-dependent ionic conductivity measurements revealed both Arrhenius and VTF models of the conductivity depending on the sample. Surface visualization through scanning electron microscopy (SEM) demonstrated good uniformity. The samples were also applied in small electrochromic devices and showed good electrochemical stability. The present work confirmed that these materials may perform as satisfactory multifunctional component layers in the field of electrochemical devices.

  14. Lithium Ion Transport Across and Between Phase Boundaries in Heterogeneous Polymer Electrolytes, Based on PVdF

    National Research Council Canada - National Science Library

    Greenbaum, Steven

    1998-01-01

    Initial investigations of polymer electrolytes based on PVdF-HFP and LiPF6 dissolved in either EC/PC or EC/DMC mixtures have been carried out via high pressure complex impedance methods and 7Li NMR...

  15. All-Solid-State Lithium-Sulfur Battery based on a nanoconfined LiBH 4 Electrolyte

    NARCIS (Netherlands)

    Das, Supti; Ngene, Peter; Norby, Poul; Vegge, Tejs; de Jongh, P.E.; Blanchard, Didier

    2016-01-01

    In this work we characterize all-solid-state lithium-sulfur batteries based on nano-confined LiBH4in mesoporous silica as solid electrolytes. The nano-confined LiBH4has fast ionic lithium conductivity at room temperature, 0.1 mScm-1, negligible electronic conductivity and its cationic transport

  16. Towards A Model-based Prognostics Methodology for Electrolytic Capacitors: A Case Study Based on Electrical Overstress Accelerated Aging

    Directory of Open Access Journals (Sweden)

    Gautam Biswas

    2012-12-01

    Full Text Available This paper presents a model-driven methodology for predict- ing the remaining useful life of electrolytic capacitors. This methodology adopts a Kalman filter approach in conjunction with an empirical state-based degradation model to predict the degradation of capacitor parameters through the life of the capacitor. Electrolytic capacitors are important components of systems that range from power supplies on critical avion- ics equipment to power drivers for electro-mechanical actuators. These devices are known for their comparatively low reliability and given their critical role in the system, they are good candidates for component level prognostics and health management. Prognostics provides a way to assess remain- ing useful life of a capacitor based on its current state of health and its anticipated future usage and operational conditions. This paper proposes and empirical degradation model and discusses experimental results for an accelerated aging test performed on a set of identical capacitors subjected to electrical stress. The data forms the basis for developing the Kalman-filter based remaining life prediction algorithm.

  17. Electrical analysis of amorphous corn starch-based polymer electrolyte membranes doped with LiI

    Science.gov (United States)

    Shukur, M. F.; Ibrahim, F. M.; Majid, N. A.; Ithnin, R.; Kadir, M. F. Z.

    2013-08-01

    In this work, polymer electrolytes have been prepared by doping starch with lithium iodide (LiI). The incorporation of 30 wt% LiI optimizes the room temperature conductivity of the electrolyte at (1.83 ± 0.47) × 10-4 S cm-1. Further conductivity enhancement to (9.56 ± 1.19) × 10-4 S cm-1 is obtained with the addition of 30 wt% glycerol. X-ray diffraction analysis indicates that the conductivity enhancement is due to the increase in amorphous content. The activation energy, Ea, of 70 wt% starch-30 wt% LiI electrolyte is 0.26 eV, while 49 wt% starch-21 wt% LiI-30 wt% glycerol electrolyte exhibits an Ea of 0.16 eV. Dielectric studies show that all the electrolytes obey non-Debye behavior. The power law exponent s is obtained from the variation of dielectric loss, ɛi, with frequency at different temperatures. The conduction mechanism of 70 wt% starch-30 wt% LiI electrolyte can be explained by the correlated barrier hopping model, while the conduction mechanism for 49 wt% starch-21 wt% LiI-30 wt% glycerol electrolyte can be represented by the quantum mechanical tunneling model.

  18. Preparation of Ferrotitanium Alloys by Electrolysis-Assisted Calciothermic Reduction of Ilmenite in Equimolar CaCl2-NaCl Electrolyte: Effect of Calcium Oxide

    Science.gov (United States)

    Zhou, Zhongren; Zhang, Yingjie; Hua, Yixin; Xu, Cunying; Dong, Peng; Zhang, Qibo; Wang, Ding

    2018-01-01

    The effect of CaO content on the preparation of ferrotitanium alloys from ilmenite with the method of the electrolysis-assisted calciothermic reduction has been investigated by use of ilmenite powders as raw materials that positions them next to the cathodic molybdenum plate, equimolar CaCl2-NaCl molten salt with 2-7 mol.% CaO as electrolyte and graphite as anode at 700°C with cell voltage of 2.8 V under argon atmosphere. It is demonstrated that increasing the reactant CaO content is beneficial to the calciothermic reduction of ilmenite and the intermediate CaTiO3. Experimental results also show that after 14 h of calciothermic reduction process, the products are ferrotitanium alloys and the specific energy consumption is only about 10.21 kWh kg-1 when adding 5 mol.% CaO into equimolar CaCl2-NaCl molten salt and approximately 14.40 kWh kg-1 when CaO content is increased to 7 mol.%.

  19. Preparation of Ferrotitanium Alloys by Electrolysis-Assisted Calciothermic Reduction of Ilmenite in Equimolar CaCl2-NaCl Electrolyte: Effect of Calcium Oxide

    Science.gov (United States)

    Zhou, Zhongren; Zhang, Yingjie; Hua, Yixin; Xu, Cunying; Dong, Peng; Zhang, Qibo; Wang, Ding

    2018-04-01

    The effect of CaO content on the preparation of ferrotitanium alloys from ilmenite with the method of the electrolysis-assisted calciothermic reduction has been investigated by use of ilmenite powders as raw materials that positions them next to the cathodic molybdenum plate, equimolar CaCl2-NaCl molten salt with 2-7 mol.% CaO as electrolyte and graphite as anode at 700°C with cell voltage of 2.8 V under argon atmosphere. It is demonstrated that increasing the reactant CaO content is beneficial to the calciothermic reduction of ilmenite and the intermediate CaTiO3. Experimental results also show that after 14 h of calciothermic reduction process, the products are ferrotitanium alloys and the specific energy consumption is only about 10.21 kWh kg-1 when adding 5 mol.% CaO into equimolar CaCl2-NaCl molten salt and approximately 14.40 kWh kg-1 when CaO content is increased to 7 mol.%.

  20. Separators for Li-Ion and Li-Metal Battery Including Ionic Liquid Based Electrolytes Based on the TFSI− and FSI− Anions

    Directory of Open Access Journals (Sweden)

    Marija Kirchhöfer

    2014-08-01

    Full Text Available The characterization of separators for Li-ion or Li-metal batteries incorporating hydrophobic ionic liquid electrolytes is reported herein. Ionic liquids made of N-butyl-N-methylpyrrolidinium (PYR14+ or N-methoxyethyl-N-methylpyrrolidinium (PYR12O1+, paired with bis(trifluoromethanesulfonylimide (TFSI− or bis(fluorosulfonylimide (FSI− anions, were tested in combination with separators having different chemistries and morphologies in terms of wetting behavior, Gurley and McMullin number, as well as Li/(Separator + Electrolyte interfacial properties. It is shown that non-functionalized microporous polyolefin separators are poorly wetted by FSI−-based electrolytes (contrary to TFSI−-based electrolytes, while the ceramic coated separator Separion® allows good wetting with all electrolytes. Furthermore, by comparing the lithium solid electrolyte interphase (SEI resistance evolution at open circuit and during cycling, depending on separator morphologies and chemistries, it is possible to propose a scale for SEI forming properties in the order: PYR12O1FSI > PYR14FSI > PYR14TFSI > PYR12O1TFSI. Finally, the impact the separator morphology is evidenced by the SEI resistance evolution and by comparing Li electrodes cycled using separators with two different morphologies.

  1. Electrical characterization of proton conducting polymer electrolyte based on bio polymer with acid dopant

    Energy Technology Data Exchange (ETDEWEB)

    Kalaiselvimary, J.; Pradeepa, P.; Sowmya, G.; Edwinraj, S.; Prabhu, M. Ramesh, E-mail: email-mkram83@gmail.com [Department of Physics, Alagappa University, Karaikudi – 630 004, India. (India)

    2016-05-06

    This study describes the biodegradable acid doped films composed of chitosan and Perchloric acid with different ratios (2.5 wt %, 5 wt %, 7.5 wt %, 10 wt %) was prepared by the solution casting technique. The temperature dependence of the proton conductivity of complex electrolytes obeys the Arrhenius relationship. Proton conductivity of the prepared polymer electrolyte of the bio polymer with acid doped was measured to be approximately 5.90 × 10{sup −4} Scm{sup −1}. The dielectric data were analyzed using Complex impedance Z*, Dielectric loss ε’, Tangent loss for prepared polymer electrolyte membrane with the highest conductivity samples at various temperature.

  2. Comparing the rehydration potential of different milk-based drinks to a carbohydrate-electrolyte beverage.

    Science.gov (United States)

    Desbrow, Ben; Jansen, Sarah; Barrett, Abby; Leveritt, Michael D; Irwin, Christopher

    2014-12-01

    The aim of this study was to compare the rehydration potential of a carbohydrate-electrolyte beverage with several varieties of milk following exercise-induced fluid losses. Fifteen male participants (age 24.9 ± 5.5 years, height 179.3 ± 4.9 cm, body mass 75.8 ± 6.6 kg (mean ± SD)) lost 2.0% ± 0.2% body mass through intermittent cycling before consuming a different beverage on 4 separate occasions. Drinks included cow's milk (286 kJ·100 mL(-1)), soy milk (273 kJ·100 mL(-1)), a milk-based liquid meal supplement (Sustagen Sport (Nestle); 417 kJ·100 mL(-1)), and a sports drink (Powerade (Coca Cola Ltd); 129 kJ·100 mL(-1)). Beverages were consumed over 1 h in volumes equivalent to 150% of body mass loss. Body mass, blood and urine samples, and measures of gastrointestinal tolerance were obtained before and hourly for 4 h after beverage consumption. Net body mass at the conclusion of each trial was significantly less with Powerade (-1.37 ± 0.3 kg) than with cow's milk (-0.92 ± 0.48 kg), soy milk (-0.78 ± 0.37 kg), and Sustagen Sport (-0.48 ± 0.39 kg). Net body mass was also significantly greater for Sustagen Sport compared with cow's milk trials, but not soy milk. Upon completion of trials, the percentage of beverage retained was Sustagen Sport 65.1% ± 14.7%, soy milk 46.9% ± 19.9%, cow's milk 40.0% ± 24.9%, and Powerade 16.6% ± 16.5%. Changes in plasma volume and electrolytes were unaffected by drink treatment. Subjective ratings of bloating and fullness were higher during all milk trials compared with Powerade whereas ratings of overall thirst were not different between beverages. Milk-based drinks are more effective rehydration options compared with traditional sports drinks. The additional energy, protein, and sodium in a milk-based liquid meal supplement facilitate superior fluid recovery following exercise.

  3. Influence of polyoxyethylene phytosterol addition in ionic liquid-based electrolyte on photovoltaic performance of dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Takahashi, Masashi; Sato, Kei; Sakurai, Sho; Kobayashi, Koichi

    2016-01-01

    Highlights: • The ionic liquid solution of less solvophilic BPS exhibits a better surface active property and a weaker dye-desorption effect. • Photovoltaic performances of the N719- and NKX2677-sensitized DSSCs can be improved by the BPS addition to the IL-based electrolyte. • BPS added to the electrolyte plays a key role in reducing charge-transfer resistance and increasing electron lifetime in the TiO 2 electrode. - Abstract: In this work, we studied influence of polyoxyethylene phytosterol (BPS) addition in ionic liquid (IL)-based electrolyte on photovoltaic performance of dye-sensitized solar cells (DSSCs) using 1-methyl-3-propylimidazolium iodide as an IL. Surface tension, photocurrent density-voltage characteristics and electrochemical impedance spectra were measured to clarify the role of BPS in the DSSCs using three different dyes. The results showed that the IL solution of less solvophilic BPS-EO5 exhibited a better surface active property and a weaker dye-desorption effect than BPS-EO30 and BPS-PO7/EO30. Short-circuit current densities of the N719- and NKX2677-sensitized cells were found to be noticeably increased by the addition of either BPS-EO5 or BPS-EO30 to the IL-based electrolyte in the concentration range of 0.001–0.01 mol dm −3 . Enhanced photovoltaic conversion efficiencies were obtained for these DSSCs, which most likely resulted from the effects of BPS on reducing charge-transfer resistance at the TiO 2 /dye/electrolyte interface and on increasing electron lifetime within the TiO 2 photoanode.

  4. Physics Based Electrolytic Capacitor Degradation Models for Prognostic Studies under Thermal Overstress

    Data.gov (United States)

    National Aeronautics and Space Administration — Electrolytic capacitors are used in several applications rang- ing from power supplies on safety critical avionics equipment to power drivers for electro-mechanical...

  5. Gel polymer electrolytes based on PMMA III. PMMA gels containing cadmium

    Czech Academy of Sciences Publication Activity Database

    Vondrák, Jiří; Sedlaříková, M.; Velická, Jana; Klápště, Břetislav; Novák, V.; Reiter, Jakub

    2003-01-01

    Roč. 48, č. 8 (2003), s. 1001-1004 ISSN 0013-4686 R&D Projects: GA AV ČR IAA4032002; GA ČR GA104/02/0731; GA MŠk ME 216 Institutional research plan: CEZ:AV0Z4032918; CEZ:MSM 262200010 Keywords : gel polymer electrolytes * polymethylmethacrylate * cadmium gel electrolyte Subject RIV: CA - Inorganic Chemistry Impact factor: 1.996, year: 2003

  6. American Society of Nephrology Quiz and Questionnaire 2013: electrolyte and acid-base.

    Science.gov (United States)

    Palmer, Biff F; Perazella, Mark A; Choi, Michael J

    2014-06-06

    The Nephrology Quiz and Questionnaire (NQ&Q) remains an extremely popular session for attendees of the annual meeting of the American Society of Nephrology. As in past years, the conference hall was overflowing with interested audience members. Topics covered by expert discussants included electrolyte and acid-base disorders, glomerular disease, ESRD/dialysis, and transplantation. Complex cases representing each of these categories along with single-best-answer questions were prepared by a panel of experts. Prior to the meeting, program directors of United States nephrology training programs answered questions through an Internet-based questionnaire. A new addition to the NQ&Q was participation in the questionnaire by nephrology fellows. To review the process, members of the audience test their knowledge and judgment on a series of case-oriented questions prepared and discussed by experts. Their answers are compared in real time using audience response devices with the answers of nephrology fellows and training program directors. The correct and incorrect answers are then briefly discussed after the audience responses, and the results of the questionnaire are displayed. This article recapitulates the session and reproduces its educational value for the readers of CJASN. Enjoy the clinical cases and expert discussions. Copyright © 2014 by the American Society of Nephrology.

  7. American Society of Nephrology Quiz and Questionnaire 2015: Electrolytes and Acid-Base Disorders.

    Science.gov (United States)

    Rosner, Mitchell H; Perazella, Mark A; Choi, Michael J

    2016-04-07

    The Nephrology Quiz and Questionnaire remains an extremely popular session for attendees of the annual Kidney Week meeting of the American Society of Nephrology. During the 2015 meeting the conference hall was once again overflowing with eager quiz participants. Topics covered by the experts included electrolyte and acid-base disorders, glomerular disease, end-stage renal disease and dialysis, and kidney transplantation. Complex cases representing each of these categories together with single-best-answer questions were prepared and submitted by the panel of experts. Before the meeting, training program directors of nephrology fellowship programs and nephrology fellows in the United States answered the questions through an internet-based questionnaire. During the live session members of the audience tested their knowledge and judgment on the same series of case-oriented questions in a quiz. The audience compared their answers in real time using a cell-phone app containing the answers of the nephrology fellows and training program directors. The results of the online questionnaire were displayed, and then the quiz answers were discussed. As always, the audience, lecturers, and moderators enjoyed this highly educational session. This article recapitulates the session and reproduces selected content of educational value for theClinical Journal of the American Society of Nephrologyreaders. Enjoy the clinical cases and expert discussions. Copyright © 2016 by the American Society of Nephrology.

  8. Interaction of High Flash Point Electrolytes and PE-Based Separators for Li-Ion Batteries

    Science.gov (United States)

    Hofmann, Andreas; Kaufmann, Christoph; Müller, Marcus; Hanemann, Thomas

    2015-01-01

    In this study, promising electrolytes for use in Li-ion batteries are studied in terms of interacting and wetting polyethylene (PE) and particle-coated PE separators. The electrolytes are characterized according to their physicochemical properties, where the flow characteristics and the surface tension are of particular interest for electrolyte–separator interactions. The viscosity of the electrolytes is determined to be in a range of η = 4–400 mPa∙s and surface tension is finely graduated in a range of γL = 23.3–38.1 mN∙m−1. It is verified that the technique of drop shape analysis can only be used in a limited matter to prove the interaction, uptake and penetration of electrolytes by separators. Cell testing of Li|NMC half cells reveals that those cell results cannot be inevitably deduced from physicochemical electrolyte properties as well as contact angle analysis. On the other hand, techniques are more suitable which detect liquid penetration into the interior of the separator. It is expected that the results can help fundamental researchers as well as users of novel electrolytes in current-day Li-ion battery technologies for developing and using novel material combinations. PMID:26343636

  9. Interaction of High Flash Point Electrolytes and PE-Based Separators for Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Andreas Hofmann

    2015-08-01

    Full Text Available In this study, promising electrolytes for use in Li-ion batteries are studied in terms of interacting and wetting polyethylene (PE and particle-coated PE separators. The electrolytes are characterized according to their physicochemical properties, where the flow characteristics and the surface tension are of particular interest for electrolyte–separator interactions. The viscosity of the electrolytes is determined to be in a range of η = 4–400 mPa∙s and surface tension is finely graduated in a range of γL = 23.3–38.1 mN∙m−1. It is verified that the technique of drop shape analysis can only be used in a limited matter to prove the interaction, uptake and penetration of electrolytes by separators. Cell testing of Li|NMC half cells reveals that those cell results cannot be inevitably deduced from physicochemical electrolyte properties as well as contact angle analysis. On the other hand, techniques are more suitable which detect liquid penetration into the interior of the separator. It is expected that the results can help fundamental researchers as well as users of novel electrolytes in current-day Li-ion battery technologies for developing and using novel material combinations.

  10. Projection pursuit-based dimensionality reduction

    Science.gov (United States)

    Safavi, Haleh; Chang, Chein-I.

    2008-04-01

    Dimensionality Reduction (DR) has found many applications in hyperspectral image processing, e.g., data compression, endmember extraction. This paper investigates Projection Pursuit (PP)-based data dimensionality reduction where three approaches are developed. One is to use a Projection Index (PI) to produce projection vectors that can be used to generate Projection Index Components (PICs). It is a common practice that PP generally uses random initial conditions to produce PICs. As a result, when the same PP is performed in different times or different users at the same time, the resulting PICs are generally not the same. In order to resolve this issue, two approaches are proposed. One is referred to as PI-based PRioritized PP (PI-PRPP) which uses a PI as a criterion to prioritize PICs that are produced by any component analysis, for example, Principal Components Analysis (PCA) or Independent Component Analysis. The other approach is called Initialization-Driven PP (ID-PP) which specifies an appropriate set of initial conditions that allows PP to not only produce PICs in the same order but also the same PICs regardless of how many times PP is run or who runs the PP.

  11. Polyfluorinated boron cluster based salts: A new electrolyte for application in nonaqueous asymmetric AC/Li{sub 4}Ti{sub 5}O{sub 12} supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Ionica-Bousquet, C.M.; Munoz-Rojas, D.; Palacin, M.R. [Institut de Ciencia de Materials de Barcelona, CSIC, Campus UAB, E-08193 Bellaterra (Spain); Casteel, W.J. Jr.; Pearlstein, R.M.; Kumar, G. Girish; Pez, G.P. [Air Products and Chemicals, Inc., 7201 Hamilton Blvd., Allentown, PA 18195 (United States)

    2011-02-01

    Solutions of novel fluorinated lithium dodecaborate (Li{sub 2}B{sub 12}F{sub x}H{sub 12-x}) salts have been evaluated as electrolytes in nonaqueous asymmetric supercapacitors with Li{sub 4}Ti{sub 5}O{sub 12} as negative electrode, and activated carbon (AC) as positive electrode. The results obtained with these new electrolytes were compared with those obtained with cells built using standard 1 M LiPF{sub 6} dissolved in ethylene carbonate and dimethyl carbonate (EC:DMC; 1:1, v/v) as electrolyte. The specific energy, rate capability, and cycling performances of nonaqueous asymmetric cells based on these new electrolyte salts were studied. Cells assembled using the new fluoroborate salts show excellent reversibility, coulombic efficiency, rate capability and improved cyclability when compared with the standard electrolyte. These features confirm the suitability of lithium-fluoro-borate based salts to be used in nonaqueous asymmetric supercapacitors. (author)

  12. Basic principles of electrolyte chemistry for microfluidic electrokinetics. Part I: Acid-base equilibria and pH buffers.

    Science.gov (United States)

    Persat, Alexandre; Chambers, Robert D; Santiago, Juan G

    2009-09-07

    We review fundamental and applied acid-base equilibrium chemistry useful to microfluidic electrokinetics. We present elements of acid-base equilibrium reactions and derive rules for pH calculation for simple buffers. We also present a general formulation to calculate pH of more complex, arbitrary mixtures of electrolytes, and discuss the effects of ionic strength and temperature on pH calculation. More practically, we offer advice on buffer preparation and on buffer reporting. We also discuss "real world" buffers and likely contamination sources. In particular, we discuss the effects of atmospheric carbon dioxide on buffer systems, namely, the increase in ionic strength and acidification of typical electrokinetic device buffers. In Part II of this two-paper series, we discuss the coupling of acid-base equilibria with electrolyte dynamics and electrochemistry in typical microfluidic electrokinetic systems.

  13. The ionic conductivity, mechanical performance and morphology of two-phase structural electrolytes based on polyethylene glycol, epoxy resin and nano-silica

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Qihang; Yang, Jiping, E-mail: jyang08@163.com; Yu, Yalin; Tian, Fangyu; Zhang, Boming; Feng, Mengjie; Wang, Shubin

    2017-05-15

    Highlights: • Structural electrolytes based on PEG-epoxy resins were prepared. • Factors of influencing ionic conductivity and mechanical properties were studied. • Co-continuous morphology was benefit for improved structural electrolyte property. • Efficiently optimized multifunctional electrolyte performance was achieved. - Abstract: As one of significant parts of structural power composites, structural electrolytes have desirable mechanical properties like structural resins while integrating enough ionic conductivity to work as electrolytes. Here, a series of polyethylene glycol (PEG)-epoxy-based electrolytes filled with nano-silica were prepared. The ionic conductivity and mechanical performance were studied as functions of PEG content, lithium salt concentration, nano-silica content and different curing agents. It was found that, PEG-600 and PEG-2000 content in the epoxy electrolyte system had a significant effect on their ionic conductivity. Furthermore, increasing the nano-silica content in the system induced increased ionic conductivity, decreased glass transition temperature and mechanical properties, and more interconnected irregular network in the cured systems. The introduction of rigid m-xylylenediamine resulted in enhanced mechanical properties and reasonably decreased ionic conductivity. As a result, these two-phase epoxy structural electrolytes have great potential to be used in the multifunctional energy storage devices.

  14. SISGR: Improved Electrical Energy Storage with Electrochemical Double Layer Capacitance Based on Novel Carbon Electrodes, New Electrolytes, and Thorough Development of a Strong Science Base

    Energy Technology Data Exchange (ETDEWEB)

    Ruoff, Rodney S. [PI; Alam, Todd M. [co-PI; Bielawski, Christopher W. [co-PI; Chabal, Yves [co-PI; Hwang, Gyeong [co-PI; Ishii, Yoshitaka [co-PI; Rogers, Robin [co-PI

    2014-07-23

    The broad objective of the SISGR program is to advance the fundamental scientific understanding of electrochemical double layer capacitance (EDLC) and thus of ultracapacitor systems composed of a new type of electrode based on chemically modified graphene (CMG) and (primarily) with ionic liquids (ILs) as the electrolyte. Our team has studied the interplay between graphene-based and graphene-derived carbons as the electrode materials in electrochemical double layer capacitors (EDLC) systems on the one hand, and electrolytes including novel ionic liquids (ILs), on the other, based on prior work on the subject.

  15. Conductivity and transport studies of plasticized chitosan-based proton conducting biopolymer electrolytes

    International Nuclear Information System (INIS)

    Shukur, M F; Yusof, Y M; Zawawi, S M M; Illias, H A; Kadir, M F Z

    2013-01-01

    This paper focuses on the conductivity and transport properties of chitosan-based solid biopolymer electrolytes containing ammonium thiocyanate (NH 4 SCN). The sample containing 40 wt% NH 4 SCN exhibited the highest conductivity value of (1.81 ± 0.50) × 10 −4  S cm −1 at room temperature. Conductivity has increased to (1.51 ± 0.12) × 10 −3  S cm −1 with the addition of 25 wt% glycerol. The temperature dependence of conductivity for both salted and plasticized systems obeyed the Arrhenius rule. The activation energy (E a ) was calculated for both systems and it is found that the sample with 40 wt% NH 4 SCN in the salted system obtained an E a value of 0.148 eV and that for the sample containing 25 wt% glycerol in the plasticized system is 0.139 eV. From the Fourier transform infrared studies, carboxamide and amine bands shifted to lower wavenumbers, indicating that chitosan has interacted with NH 4 SCN salt. Changes in the C–O stretching vibration band intensity are observed at 1067 cm −1 with the addition of glycerol. The Rice and Roth model was used to explain the transport properties of the salted and plasticized systems. (paper)

  16. Conductivity and transport studies of plasticized chitosan-based proton conducting biopolymer electrolytes

    Science.gov (United States)

    Shukur, M. F.; Yusof, Y. M.; Zawawi, S. M. M.; Illias, H. A.; Kadir, M. F. Z.

    2013-11-01

    This paper focuses on the conductivity and transport properties of chitosan-based solid biopolymer electrolytes containing ammonium thiocyanate (NH4SCN). The sample containing 40 wt% NH4SCN exhibited the highest conductivity value of (1.81 ± 0.50) × 10-4 S cm-1 at room temperature. Conductivity has increased to (1.51 ± 0.12) × 10-3 S cm-1 with the addition of 25 wt% glycerol. The temperature dependence of conductivity for both salted and plasticized systems obeyed the Arrhenius rule. The activation energy (Ea) was calculated for both systems and it is found that the sample with 40 wt% NH4SCN in the salted system obtained an Ea value of 0.148 eV and that for the sample containing 25 wt% glycerol in the plasticized system is 0.139 eV. From the Fourier transform infrared studies, carboxamide and amine bands shifted to lower wavenumbers, indicating that chitosan has interacted with NH4SCN salt. Changes in the C-O stretching vibration band intensity are observed at 1067 cm-1 with the addition of glycerol. The Rice and Roth model was used to explain the transport properties of the salted and plasticized systems.

  17. Implantable electrolyte conductance-based pressure sensing catheter, II. Device construction and testing.

    Science.gov (United States)

    Tan, Robert; Benharash, Peyman; Schulam, Peter; Schmidt, Jacob J

    2013-12-01

    Direct measurements of arterial blood pressure most commonly use bulky external instrumentation containing a pressure transducer connected to an ex vivo fluid-filled arterial line, which is subject to several sensing artifacts. In situ blood pressure sensors, typically solid state piezoresistive, capacitive, and interferometric sensors, are unaffected by these artifacts, but can be expensive to produce and miniaturize. We have developed an alternative approach to blood pressure measurement based on deformation of an elastic tube filled with electrolyte solution. Simple measurement of the electrical conductance of this solution as the tube dimensions change allows determination of the external pressure. The sensor is made from inexpensive materials and its miniaturization is straightforward. In vitro static testing of initial sensor prototypes mounted on a catheter tip showed a linear response with applied pressure and a resolution of 1 mmHg. In vivo sensing followed catheterization of the sensor into the femoral artery of a porcine model through a 7F catheter port. The sensor performed comparably to a commercial pressure transducer also connected to the catheter port. Due to its scalability and cost, this sensor has the potential for use in a range of pressure sensing applications, such as measurement of intracranial, spinal, or interstitial pressures.

  18. Electrical, thermal and structural properties of plasticized waste cooking oil-based polyurethane solid polymer electrolyte

    Science.gov (United States)

    Huzaizi, Rahmatina Mohd; Tahir, Syuhada Mohd; Mahbor, Kamisah Mohamad

    2017-12-01

    Waste cooking oil-based polyol was synthesized using epoxidation and hydroxylation methods. The polyol was combined with 4,4-diphenylmethane diisocyanate to produce polyurethane (PU) to be used as polymer host in solid polymer electrolyte. 30 wt% LiClO4 was added as doping salt and two types of plasticizers were used; ethylene carbonate (PU-EC) and polyethylene glycol (PU-PEG). The SPE films were characterized using Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The highest conductivity achieved was 8.4 x 10-8 S cm-1 upon addition of 10 wt% EC. The XRD results showed a decrease of crystalline peaks in PU-EC and the increase in PU-PEG. DSC results revealed that the films; PU, PU-EC and PU-PEG had glass transition temperatures of 159.7, 106.0 and 179.7 °C, respectively. The results showed that the addition of EC increased the amorphous region and the free volume in the SPE structure, thus resulted in higher ionic conductivity.

  19. Durable rechargeable zinc-air batteries with neutral electrolyte and manganese oxide catalyst

    Science.gov (United States)

    Sumboja, Afriyanti; Ge, Xiaoming; Zheng, Guangyuan; Goh, F. W. Thomas; Hor, T. S. Andy; Zong, Yun; Liu, Zhaolin

    2016-11-01

    Neutral chloride-based electrolyte and directly grown manganese oxide on carbon paper are used as the electrolyte and air cathode respectively for rechargeable Zn-air batteries. Oxygen reduction and oxygen evolution reactions on manganese oxide show dependence of activities on the pH of the electrolyte. Zn-air batteries with chloride-based electrolyte and manganese oxide catalyst exhibit satisfactory voltage profile (discharge and charge voltage of 1 and 2 V at 1 mA cm-2) and excellent cycling stability (≈90 days of continuous cycle test), which is attributed to the reduced carbon corrosion on the air cathode and decreased carbonation in neutral electrolyte. This work describes a robust electrolyte system that improves the cycle life of rechargeable Zn-air batteries.

  20. Polymer Electrolytes Based on Borane/Poly(ethylene glycol Methyl Ether for Lithium Batteries

    Directory of Open Access Journals (Sweden)

    Ali Murat Soydan

    2017-01-01

    Full Text Available This work presents a different approach to preparing polymer electrolytes having borate ester groups for lithium ion batteries. The polymers were synthesized by reaction between poly(ethylene glycol methyl ether (PEGME and BH3-THF complex. Molecular weight of PEGMEs was changed with different chain lengths. Then the polymer electrolytes comprising boron were prepared by doping of the matrices with CF3SO3Li at various molar ratios with respect to EO to Li and they are abbreviated as PEGMEX-B-Y. The identification of the PEGME-borate esters was carried out by FTIR and 1H NMR spectroscopy. Thermal properties of these electrolytes were investigated via thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. The ionic conductivity of these novel polymer electrolytes was studied by dielectric-impedance spectroscopy. Lithium ion conductivity of these electrolytes was changed by the length of PEGME as well as the doping ratios. They exhibit approximate conductivities of 10−4 S·cm−1 at 30°C and 10−3 S·cm−1 at 100°C.

  1. Vanadium Flow Battery Electrolyte Synthesis via Chemical Reduction of V2O5 in Aqueous HCl and H2SO4.

    Energy Technology Data Exchange (ETDEWEB)

    Small, Leo J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pratt, Harry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Staiger, Chad [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Martin, Rachel Irene [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Anderson, Travis Mark [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Chalamala, Babu [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Soundappan, Thiagarajan [Univ. of Washington, Seattle, WA (United States); Tiwari, Monika [Univ. of Washington, Seattle, WA (United States); Subarmanian, Venkat R. [Univ. of Washington, Seattle, WA (United States)

    2017-01-01

    We report a simple method to synthesize V 4+ (VO 2+ ) electrolytes as feedstock for all- vanadium redox flow batteries (RFB). By dissolving V 2 O 5 in aqueous HCl and H 2 SO 4 , subsequently adding glycerol as a reducing agent, we have demonstrated an inexpensive route for electrolyte synthesis to concentrations >2.5 M V 4+ (VO 2+ ). Electrochemical analysis and testing of laboratory scale RFB demonstrate improved thermal stability across a wider temperature range (-10-65 degC) for V 4+ (VO 2+ ) electrolytes in HCl compared to in H 2 SO 4 electrolytes.

  2. Effect of poly(ethylene oxide) on ionic conductivity and electrochemical properties of poly(vinylidenefluoride) based polymer gel electrolytes prepared by electrospinning for lithium ion batteries

    Science.gov (United States)

    Prasanth, Raghavan; Shubha, Nageswaran; Hng, Huey Hoon; Srinivasan, Madhavi

    2014-01-01

    Effect of poly(ethylene oxide) on the electrochemical properties of polymer electrolyte based on electrospun, non-woven membrane of PVdF is demonstrated. Electrospinning process parameters are controlled to get a fibrous membrane consisting of bead-free, uniformly dispersed thin fibers with diameter in the range of 1.5-1.9 μm. The membrane with good mechanical strength and porosity exhibits high uptake when activated with the liquid electrolyte of lithium salt in a mixture of organic solvents. The polymer gel electrolyte shows ionic conductivity of 4.9 × 10-3 S cm-1 at room temperature. Electrochemical performance of the polymer gel electrolyte is evaluated in Li/polymer electrolyte/LiFePO4 coin cell. Good performance with low capacity fading on charge-discharge cycling is demonstrated.

  3. Receiver based PAPR reduction in OFDMA

    KAUST Repository

    Ali, Anum Z.

    2014-05-01

    High peak-to-average power ratio is one of the major drawbacks of orthogonal frequency division multiplexing (OFDM). Clipping is the simplest peak reduction scheme, however, it requires clipping mitigation at the receiver. Recently compressed sensing has been used for clipping mitigation (by exploiting the sparse nature of clipping signal). However, clipping estimation in multi-user scenario (i.e., OFDMA) is not straightforward as clipping distortions overlap in frequency domain and one cannot distinguish between distortions from different users. In this work, a collaborative clipping removal strategy is proposed based on joint estimation of the clipping distortions from all users. Further, an effective data aided channel estimation strategy for clipped OFDM is also outlined. Simulation results are presented to justify the effectiveness of the proposed schemes. © 2014 IEEE.

  4. New Polymer Electrolyte Membranes Based on Acid Doped PBI For Fuel Cells Operating above 100°C

    DEFF Research Database (Denmark)

    Li, Qingfeng

    2003-01-01

    The technical achievement and challenges for the PEMFC technology based on perfluorosulfonic acid (PFSA) polymer membranes (e.g. Nafion®) are briefly discussed. The newest development for alternative polymer electrolytes for operation above 100°C. As one of the successful approaches to high opera...... operational temperatures, the development and evaluation of acid doped PBI membranes are reviewed, covering polymer synthesis, membrane casting, acid doping, physiochemical characterization and fuel cell tests....

  5. Nb-doped TiO2 cathode catalysts for oxygen reduction reaction of polymer electrolyte fuel cells

    KAUST Repository

    Arashi, Takuya

    2014-09-01

    Nb-doped TiO2 particles were studied as electrocatalysts for the oxygen reduction reaction (ORR) under acidic conditions. The Nb-doped TiN nanoparticles were first synthesized by meso-porous C3N4 and then fully oxidized to Nb-doped TiO2 by immersing in 0.1 M H 2SO4 at 353 K for 24 h. Although the ORR activity of the as-obtained sample was low, a H2 treatment at relatively high temperature (1173 K) dramatically improved the ORR performance. An onset potential as high as 0.82 VRHE was measured. No degradation of the catalysts was observed during the oxidation-reduction cycles under the ORR condition for over 127 h. H2 treatment at temperatures above 1173 K caused the formation of a Ti4O7 phase, resulting in a decrease in ORR current. Elemental analysis indicated that the Nb-doped TiO 2 contained 25 wt% residual carbon. Calcination in air at 673 or 973 K eliminated the residual carbon in the catalyst, which was accompanied by a dramatic decrease in ORR activity. This post-calcination process may reduce the conductivity of the sample by filling the oxygen vacancies, and the carbon residue in the particle aggregates may enhance the electrocatalytic activity for ORR. The feasibility of using conductive oxide materials as electrocatalysts is discussed. © 2013 Elsevier B.V.

  6. Application of Composite Polymer Electrolytes

    National Research Council Canada - National Science Library

    Scrosati, Bruno

    2001-01-01

    ...)PEO-based composite polymer electrolytes, by a series of specifically addressed electrochemical tests which included the determination of the conductivity and of the lithium transference number...

  7. The development of a new type of rechargeable batteries based on hybrid electrolytes.

    Science.gov (United States)

    Zhou, Haoshen; Wang, Yonggang; Li, Huiqiao; He, Ping

    2010-09-24

    Lithium ion batteries (LIBs), which have the highest energy density among all currently available rechargeable batteries, have recently been considered for use in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and pure electric vehicles (PEV). A major challenge in this effort is to increase the energy density of LIBs to satisfy the industrial needs of HEVs, PHEVs, and PEVs. Recently, new types of lithium-air and lithium-copper batteries that employ hybrid electrolytes have attracted significant attention; these batteries are expected to succeed lithium ion batteries as next-generation power sources. Herein, we review the concept of hybrid electrolytes, as well as their advantages and disadvantages. In addition, we examine new battery types that use hybrid electrolytes.

  8. Electrolyte gated TFT biosensors based on the Donnan's capacitance of anchored biomolecules

    Science.gov (United States)

    Manoli, Kyriaki; Palazzo, Gerardo; Macchia, Eleonora; Tiwari, Amber; Di Franco, Cinzia; Scamarcio, Gaetano; Favia, Pietro; Mallardi, Antonia; Torsi, Luisa

    2017-08-01

    Biodetection using electrolyte gated field effect transistors has been mainly correlated to charge modulated transduction. Therefore, such platforms are designed and studied for limited applications involving relatively small charged species and much care is taken in the operating conditions particularly pH and salt concentration (ionic strength). However, there are several reports suggesting that the device conductance can also be very sensitive towards variations in the capacitance coupling. Understanding the sensing mechanism is important for further exploitation of these promising sensors in broader range of applications. In this paper, we present a thorough and in depth study of a multilayer protein system coupled to an electrolyte gated transistor. It is demonstrated that detection associated to a binding event taking place at a distance of 30 nm far from the organic semiconductor-electrolyte interface is possible and the device conductance is dominated by Donnan's capacitance of anchored biomolecules.

  9. A hybrid thermochemical-electrolytic process for hydrogen production based on the Reverse Deacon Reaction

    International Nuclear Information System (INIS)

    Simpson, M.F.; Herrmann, S.D.; Boyle, B.D.

    2006-01-01

    Development has been initiated on a three-reaction, hybrid thermochemical-electrolytic process for splitting water into hydrogen and oxygen. This process can be run at 500 C, making it suitable for linking to nuclear reactors that run colder than the very highest temperature gas cooled reactors. This feature also makes the materials requirements less stringent than for high temperature cycles, many of which require temperatures in the range of 800-900 C. The process consists of three reactions - two thermochemical and one electrolytic. The thermochemical reactions sum to the reverse Deacon reaction. The electrolytic step involves the electrolysis of anhydrous HCl. The estimated energy savings for this process relative to electrolysis of water are in the vicinity of 15%, due to the low energy requirements of anhydrous HCl electrolysis. Preliminary experimental results indicate that a silicalite-supported catalyst for the reverse Deacon reaction has the potential of promoting fast reaction kinetics and long-term stability of the solids.

  10. Enhanced separator properties by thermal curing of poly(ethylene glycol)diacrylate-based gel polymer electrolytes for lithium-ion batteries

    International Nuclear Information System (INIS)

    Kim, Kwang Man; Poliquit, Beta Zenia; Lee, Young-Gi; Won, Jeongha; Ko, Jang Myoun; Cho, Won Il

    2014-01-01

    Highlights: • PEGDA-based gel polymer electrolytes are synthesized on separator via thermal polymerization of PEGDA with a thermal initiator and a LiPF 6 -/EC/DMC solution. • The nonwoven PVdF separator shows good absorption of gel polymer electrolytes due to high porosity and good compatibility with the precursor solution. • The inclusion of the PEGDA-based gel polymer electrolytes prolongs the cycle life through a better capacity retention ratio in lithium-ion batteries. - Abstract: Porous polyethylene (PE) or nonwoven poly(vinylidene fluoride) (PVdF) separator-supported gel polymer electrolytes are realized by thermal polymerization of a precursor solution consisting of poly(ethylene glycol)diacrylate (PEGDA) and an electrolyte solution (1 M LiPF 6 in an equal-volume mixture of ethylene carbonate and dimethyl carbonate). The polymerization conditions are optimized to include a PEGDA content of 3 wt.% in the precursor solution and subsequent heat treatment at 80 °C for 10 min. Even though the gelled PEGDA electrolyte has a lower ionic conductivity than the electrolyte solution, a Li x CoO 2 /graphite full-cell that has a gel electrolyte with optimized PEGDA content on the PVdF separator achieves a battery performance superior to the one with PE. The best battery performances achieved are a high discharge capacity (116 mAh g −1 ), a good high-rate capability (95 mAh g −1 at 5.0 C-rate), and a high capacity retention ratio (90%) after the 100th cycle. This enhancement is due to the incorporation of a polar electrolyte solution that is entrapped by the polar PEGDA matrix within the nonwoven PVdF separator, which is a more suitable host that is able to well absorb and preserve the gel electrolyte

  11. Influence of Polyethylene Glycol (PEG in CMC-NH4BR Based Polymer Electrolytes: Conductivity and Electrical Study

    Directory of Open Access Journals (Sweden)

    Nur Khalidah Zainuddin

    2017-04-01

    Full Text Available The present work was carried with new type and promising polymer electrolytes system by development of carboxylmethylcellulose (CMC doped NH4Br and plasticized with polyethylene glycol (PEG. The sample was successfullyprepared via solution casting with no separation phase and good mechanical properties. The electrical conductivity andthermal conductivity of CMC-NH4Br-PEG based PEs system have been measured by the electrical impedancespectroscopy method in the temperature range of 303–373 K. The highest ionic conductivity gained is 2.48 x 10-3 Scm-1at ambient temperature for sample contain with 8 wt. % PEG. It can be concluded that the plasticized is accountable forthe conductance and assist to enhancing the ionic conductivity of the CMC-NH4Br-PEG electrolyte system. The addition of PEG to the CMC-based electrolyte can enhance towards the cation mobility which is turn increases ionic conductivity. The conductivity-temperature of plasticized BdPEs system was found obeys the Arrhenius relation where the ionic conductivity increases with temperature and activation energy for the ions hopping of the highest conducting PEs system only required small value to migrate. The electrical studies show a non-Debye behaviour of BdPEs based on the analyzed data using complex permittivity, ε* and complex electrical modulus, M* of the sample at different temperature.

  12. Flexible High-Energy Polymer-Electrolyte-Based Rechargeable Zinc-Air Batteries.

    Science.gov (United States)

    Fu, Jing; Lee, Dong Un; Hassan, Fathy Mohamed; Yang, Lin; Bai, Zhengyu; Park, Moon Gyu; Chen, Zhongwei

    2015-10-07

    A thin-film, flexible, and rechargeable zinc-air battery having high energy density is reported particularly for emerging portable and wearable electronic applications. This freeform battery design is the first demonstrated by sandwiching a porous-gelled polymer electrolyte with a freestanding zinc film and a bifunctional catalytic electrode film. The flexibility of both the electrode films and polymer electrolyte membrane gives great freedom in tailoring the battery geometry and performance. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. In Situ Generation of Poly (Vinylene Carbonate) Based Solid Electrolyte with Interfacial Stability for LiCoO2 Lithium Batteries.

    Science.gov (United States)

    Chai, Jingchao; Liu, Zhihong; Ma, Jun; Wang, Jia; Liu, Xiaochen; Liu, Haisheng; Zhang, Jianjun; Cui, Guanglei; Chen, Liquan

    2017-02-01

    Nowadays it is extremely urgent to seek high performance solid polymer electrolyte that possesses both interfacial stability toward lithium/graphitic anodes and high voltage cathodes for high energy density solid state batteries. Inspired by the positive interfacial effect of vinylene carbonate additive on solid electrolyte interface, a novel poly (vinylene carbonate) based solid polymer electrolyte is presented via a facile in situ polymerization process in this paper. It is manifested that poly (vinylene carbonate) based solid polymer electrolyte possess a superior electrochemical stability window up to 4.5 V versus Li/Li + and considerable ionic conductivity of 9.82 × 10 -5 S cm -1 at 50 °C. Moreover, it is demonstrated that high voltage LiCoO 2 /Li batteries using this solid polymer electrolyte display stable charge/discharge profiles, considerable rate capability, excellent cycling performance, and decent safety characteristic. It is believed that poly (vinylene carbonate) based electrolyte can be a very promising solid polymer electrolyte candidate for high energy density lithium batteries.

  14. Crosslinked wholly aromatic polyether membranes based on quinoline derivatives and their application in high temperature polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Kallitsis, K. J.; Nannou, R.; Andreopoulou, A. K.; Daletou, M. K.; Papaioannou, D.; Neophytides, S. G.; Kallitsis, J. K.

    2018-03-01

    An AB type difunctional quinoline based monomer bearing a pentafluorophenyl unit combined with a phenol functionality is being synthesized and homopolymerized to create linear aromatic polyethers as polymer electrolytes for HT-PEM FCs applications. Several conditions are tested for the optimized synthesis of the monomer and homopolymer. Additionally, covalent crosslinking through aromatic polyether bond formation enables the creation of wholly aromatic crosslinked polymeric electrolyte membranes. More specifically, the perfluorophenyl units are crosslinked with other hydroxyl end functionalized moieties, providing membranes with enhanced chemical and mechanical properties that are moreover easily doped with phosphoric acid even at ambient temperatures. All membranes are evaluated for their structural and thermal characteristics and their doping ability with phosphoric acid. Selected crosslinked membranes are further tested in terms of their single cell performance at the temperature range 160 °C-200 °C showing promising performance and high conductivity values even up to 0.2 S cm-1 in some cases.

  15. A study on optical properties of poly (ethylene oxide) based polymer electrolyte with different alkali metal iodides

    Science.gov (United States)

    Rao, B. Narasimha; Suvarna, R. Padma

    2016-05-01

    Polymer electrolytes were prepared by adding poly (ethylene glycol) dimethyl ether (PEGDME), TiO2 (nano filler), different alkali metal iodide salts RI (R+=Li+, Na+, K+, Rb+, Cs+) and I2 into Acetonitrile gelated with Poly (ethylene oxide) (PEO). Optical properties of poly (ethylene oxide) based polymer electrolytes were studied by FTIR, UV-Vis spectroscopic techniques. FTIR spectrum reveals that the alkali metal cations were coordinated to ether oxygen of PEO. The optical absorption studies were made in the wavelength range 200-800 nm. It is observed that the optical absorption increases with increase in the radius of alkali metal cation. The optical band gap for allowed direct transitions was evaluated using Urbach-edges method. The optical properties such as optical band gap, refractive index and extinction coefficient were determined. The studied polymer materials are useful for solar cells, super capacitors, fuel cells, gas sensors etc.

  16. Solid Polymer Blend Electrolyte Based on Poly(ethylene oxide) and Poly(vinyl pyrrolidone) for Lithium Secondary Batteries

    Science.gov (United States)

    Kesavan, K.; Mathew, Chithra M.; Rajendran, S.; Subbu, C.; Ulaganathan, M.

    2015-02-01

    Solid polymer electrolytes have attracted considerable attention due to their wide variety of electrochemical device applications. In the present study, the fixed concentration of the salt lithium perchlorate (LiClO4) and various concentrations of poly(ethylene oxide)/poly(vinyl pyrrolidone) (PEO/PVP)-based electrolytes were prepared by solvent casting technique. The structural analysis of the present system shows that the amorphous character of the samples is responsible for the process of ion transport. Fourier transform infrared spectroscopy (FTIR) has been used to characterize the structure of polymer and confirm the complexation between the polymers and salt. The maximum ionic conductivity value is found to be 0.2307 × 10-5 S cm-1 for PEO (90 wt%)/PVP (10 wt%)/LiClO4 (8 wt%) (A1) complex at 303 K (30 °C).

  17. High optical and switching performance electrochromic devices based on a zinc oxide nanowire with poly(methyl methacrylate) gel electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Young Tea; Chu, Daping, E-mail: dpc31@cam.ac.uk [Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Neeves, Matthew; Placido, Frank [Thin Film Centre, University of the West of Scotland, Paisley PA1 2BE (United Kingdom); Smithwick, Quinn [Disney Research, 521 Circle Seven Drive, Glendale, Los Angeles, California 91201 (United States)

    2014-11-10

    High performance electrochromic devices have been fabricated and demonstrated utilizing a solid polymer electrolyte and zinc oxide (ZnO) nanowire (NW) array counter electrode. The poly(methyl methacrylate) based polymer electrolyte was spin coated upon hydrothermally grown ZnO NW array counter electrodes, while electron beam evaporated NiO{sub x} thin films formed the working electrodes. Excellent optical contrast and switching speeds were observed in the fabricated devices with active areas of 2 cm{sup 2}, exhibiting an optical contrast of 73.11% at the wavelength of 470 nm, combined with a fast switching time of 0.2 s and 0.4 s for bleaching and coloration, respectively.

  18. High optical and switching performance electrochromic devices based on a zinc oxide nanowire with poly(methyl methacrylate) gel electrolytes

    International Nuclear Information System (INIS)

    Chun, Young Tea; Chu, Daping; Neeves, Matthew; Placido, Frank; Smithwick, Quinn

    2014-01-01

    High performance electrochromic devices have been fabricated and demonstrated utilizing a solid polymer electrolyte and zinc oxide (ZnO) nanowire (NW) array counter electrode. The poly(methyl methacrylate) based polymer electrolyte was spin coated upon hydrothermally grown ZnO NW array counter electrodes, while electron beam evaporated NiO x thin films formed the working electrodes. Excellent optical contrast and switching speeds were observed in the fabricated devices with active areas of 2 cm 2 , exhibiting an optical contrast of 73.11% at the wavelength of 470 nm, combined with a fast switching time of 0.2 s and 0.4 s for bleaching and coloration, respectively

  19. Preparation of poly(ether ether ketone)-based polymer electrolytes for fuel cell membranes using grafting technique

    International Nuclear Information System (INIS)

    Hasegawa, Shin; Suzuki, Yasuyuki; Maekawa, Yasunari

    2008-01-01

    Poly(ether ether ketone) (PEEK)-based polymer electrolyte membranes (PEMs) was successfully prepared by radiation grafting of a styrene monomer into PEEK films and the consequent selective sulfonation of the grafting chains in the film state. Using milder sulfonation, the sulfonation reactions proceeded at the grafted chains in preference to the phenylene rings of PEEK main chains; as a result, the grafted films could successfully transform to a PEM with conductivity of more than 0.1 S/cm. The ion exchange capacity (IEC) and conductivity of the grafted PEEK electrolyte membranes were controlled to the ranges of 1.2-2.9 mmol/g and 0.03-0.18 S/cm by changing the grafting degree. It should be noted that this is the first example of directly transforming super-engineering plastic films into a PEM using radiation grafting

  20. Combined NMR and molecular dynamics modeling study of transport properties in sulfonamide based deep eutectic lithium electrolytes: LiTFSI based binary systems.

    Science.gov (United States)

    Pauric, Allen D; Halalay, Ion C; Goward, Gillian R

    2016-03-07

    The trend toward Li-ion batteries operating at increased (>4.3 V vs. Li/Li(+)) voltages requires the development of novel classes of lithium electrolytes with electrochemical stability windows exceeding those of LiPF6/carbonate electrolyte solutions. Several new classes of electrolytes have been synthesized and investigated over the past decade, in the search for LIB electrolytes with improved properties (increased hydrolytic stability, improved thermal abuse tolerance, higher oxidation voltages, etc.) compared with the present state-of-the-art LiPF6 and organic carbonates-based formulations. Among these are deep eutectic electrolytes (DEEs), which share many beneficial characteristics with ionic liquids, such as low vapor pressure and large electrochemical stability windows, with the added advantage of a significantly higher lithium transference number. The present work presents the pulsed field gradient NMR characterization of the transport properties (diffusion coefficients and cation transport numbers) of binary DEEs consisting of a sulfonamide solvent and lithium bis(trifluoromethanesulfonyl)imide salt. Insights into the structural and dynamical properties, which enable one to rationalize the observed ionic conductivity behavior were obtained from a combination of NMR data and MD simulations. The insights thus gained should assist the formulation of novel DEEs with improved properties for LIB applications.

  1. Improved stability of quasi-solid-state dye-sensitized solar cell based on poly (ethylene oxide)-poly (vinylidene fluoride) polymer-blend electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ying; Zhou, Cong-hua; Xu, Sheng; Hu, Hao; Chen, Bo-lei; Zhang, Jing; Wu, Su-juan; Liu, Wei [Department of Physics, Wuhan University, Wuhan 430072 (China); Zhao, Xing-zhong [Department of Physics, Wuhan University, Wuhan 430072 (China); Key Laboratory of Acoustic and Photonic Materials and Devices of Ministry of Education, Wuhan University, Wuhan 430072 (China)

    2008-12-01

    We report two improved stability dye-sensitized TiO{sub 2} solar cells using poly (ethylene oxide)-poly (vinylidene fluoride) (PEO-PVDF) polymer-blend electrolytes modified with water and ethanol as hydroxyl-rich small-molecule additives. The effect of additive on the thermal property, viscosity, conductivity and the corresponding performance of the dye-sensitized solar cell (DSSC) were studied. After introducing the water and ethanol into the PEO-PVDF polymer-blend electrolytes, the conductivity is improved compared to that of the un-added electrolyte. This is due to the enhanced free ion concentration and ion transport channels in the electrolyte because of the cross-linking ability of these hydroxyl-rich additives. The increased ion concentration can be proved by the enhanced concentration of I{sup -} and I{sub 3}{sup -} in the additive-modified electrolytes from UV-vis studies. The increased cross-linking network can be explained by the increased glass transition temperature (T{sub g}) and viscosity of these additive-modified electrolytes from DSC and rheology studies. A more homogeneous morphology of ethanol-modified electrolyte from SEM study is used to further explain the better conductivity and stability of the cells based on these additive-modified electrolytes. From the evaluation of additive effect on the performance of the corresponding DSSC, we find that introducing water and ethanol leads to an increase in short-circuit photocurrent density (J{sub sc}). This is due to the efficient transport of I{sup -}/I{sup 3-} caused by enhanced I{sup -}/I{sup 3-} concentration and increased ion transport channels in the electrolyte by adding additives. The best efficiency of 3.9% is achieved in the cell with ethanol-modified electrolyte. (author)

  2. A novel deep eutectic solvent-based ionic liquid used as electrolyte for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jhong, Huei-Ru; Wong, David Shan-Hill; Wan, Chi-Chao; Wang, Yung-Yun [Department of Chemical Engineering, National Tsing-Hua University, 101 Guang Fu Road, Section 2, Hsin-chu, Taiwan 30013 (China); Wei, Tzu-Chien [Tripod Technology Corporation, Hsin-chu, Taiwan 30013 (China)

    2009-01-15

    We utilize a quaternary ammonium salt-derivative ionic liquid called G.CI which is a eutectic mixture of glycerol and choline iodide as electrolyte for dye-sensitized solar cells. Such eutectic compound belongs to a new series of ionic liquid called deep eutectic solvents (DES), which possess many outstanding features compared to the traditional imidazolium-based ionic liquids including cheap raw materials, simple preparation procedures and better biocompatibility. Current-voltage characteristics of the G.CI/PMII-based binary electrolytes stand at 0.533 V on V{sub oc}, 12.0 mA cm{sup -2} on J{sub sc}, 0.582 on fill factor, and 3.88% cell efficiency under AM 1.5, 100 mW/cm{sup 2} illuminations. The comparable cell performance together with all the above advantages makes G.CI as a strong candidate for future electrolyte development for dye-sensitized solar cells (DSSCs). (author)

  3. Targeting adequate thermal stability and fire safety in selecting ionic liquid-based electrolytes for energy storage.

    Science.gov (United States)

    Chancelier, L; Diallo, A O; Santini, C C; Marlair, G; Gutel, T; Mailley, S; Len, C

    2014-02-07

    The energy storage market relating to lithium based systems regularly grows in size and expands in terms of a portfolio of energy and power demanding applications. Thus safety focused research must more than ever accompany related technological breakthroughs regarding performance of cells, resulting in intensive research on the chemistry and materials science to design more reliable batteries. Formulating electrolyte solutions with nonvolatile and hardly flammable ionic liquids instead of actual carbonate mixtures could be safer. However, few definitions of thermal stability of electrolytes based on ionic liquids have been reported in the case of abuse conditions (fire, shortcut, overcharge or overdischarge). This work investigates thermal stability up to combustion of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C1C4Im][NTf2]) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([PYR14][NTf2]) ionic liquids, and their corresponding electrolytes containing lithium bis(trifluoromethanesulfonyl)imide LiNTf2. Their possible routes of degradation during thermal abuse testings were investigated by thermodynamic studies under several experimental conditions. Their behaviours under fire were also tested, including the analysis of emitted compounds.

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

    Science.gov (United States)

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

    2014-06-11

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

  5. Development of structural materials to enable the electrochemical reduction of spent oxide nuclear fuel in a molten salt electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Hur, J. M.; Cho, S. H.; Lim, J. H.; Seo, C. S.; Park, S. W

    2006-02-15

    For the development of the advanced spent fuel management process based on the molten salt technology, it is essential to choose the optimum material for the process equipment handling a molten salt. In this study, corrosion behavior of Fe-base superalloy, Ni-base superalloy, non-metallic material and surface modified superalloy were investigated in the hot molten salt under oxidation atmosphere. These experimental data will suggest a guideline for the selection of corrosion resistant materials and help to find the operation criteria of each equipment in aspects of high temperature characteristics and corrosion retardation.

  6. Charge/discharge characteristics of sulfurized polyacrylonitrile composite with different sulfur content in carbonate based electrolyte for lithium batteries

    International Nuclear Information System (INIS)

    Wang Li; He Xiangming; Li Jianjun; Chen Min; Gao Jian; Jiang Changyin

    2012-01-01

    Highlights: ► The sulfurized polyacrylonitrile composite shows good performance. ► Stable cycling capacity over 700 mAh g −1 of the composite. ► Close to 100% utilization of elemental sulfur. ► Capacity retention over 97% after 80 cycles. ► Average capacity degradation rate less than 0.03% per cycle. - Abstract: The charge/discharge characteristics of sulfurized polyacrylonitrile composite (SPAN) cathodes with different sulfur content in conventional carbonate based electrolyte for rechargeable lithium batteries have been investigated. The good performance of SPAN in the carbonate based electrolyte indicates a material difference between SPAN and elemental sulfur/carbon composite materials. The SPAN with sulfur contents of 33.7%, 42.0% and 46.3% are prepared by control of heating time. The SPAN with sulfur content of 42.0% shows the best electrochemical performance, it can deliver stable cycling capacity over 700 mAh g −1 , and keep capacity retention over 97% after 80 cycles in the electrolyte of 1 M LiPF 6 /EC + DEC. The average capacity degradation rate is less than 0.03% per cycle excluding the first discharge capacity. Prototype 100 mAh Li/SPAN cell is assembled, showing energy density of 437 Wh kg −1 excluding the weight of package and capacity retention of 90.4% after 30 cycles at 100% depth of discharge. This study demonstrates that the sulfurized polyacrylonitrile composite in the electrolyte of 1 M LiPF 6 /EC + DEC is a promising battery chemistry, which materials are abundant, of low cost and easily available, to fabricate Li/SPAN batteries, paving an alternative avenue to develop high performance lithium batteries for energy storage and vehicular application.

  7. Reactivity between carbon cathode materials and electrolyte based on industrial and laboratory data

    CSIR Research Space (South Africa)

    Chauke, L

    2013-07-01

    Full Text Available . Wear of the examined carbon cathodes proceeded due to penetration of electrolyte and sodium into the cathode, followed by reactions with carbon and N(sub2) whereby AlN and NaCN formed. Once electrolysis started the carbon cathodes expanded rapidly...

  8. Synthesis and characterization of γ-Bi2O3 based solid electrolyte ...

    Indian Academy of Sciences (India)

    Administrator

    SOFC. 1. Introduction. Solid electrolytes are the most ... cubic (bcc) γ-phase can only be obtained at room tempe- rature and will be stable by the addition of small .... Scherrer equations of γ-Bi2O3 phase. Crystalline size x (Nb2O5). 27⋅42 (°). 32⋅65 ...

  9. Proton-conducting solid acid electrolytes based upon MH(PO3H)

    NARCIS (Netherlands)

    Zhou, W.

    2011-01-01

    Solid acids, such as CsHSO4 and CsH2PO4, are a novel class of anhydrous proton-conducting compounds that can be used as electrolyte in H2/O2 and direct methanol fuel cells. The disordering of the hydrogen-bonded network above the so-called superprotonic phase transition results in an increase of the

  10. Synthesis and characterization of γ-Bi2O3 based solid electrolyte ...

    Indian Academy of Sciences (India)

    Administrator

    3Chemistry Department, Art and Science Faculty, Nigde University, Nigde, Turkey. MS received 25 April 2013; revised 14 July 2013. Abstract. γ-phase bismuth oxide is a well known high oxygen ion conductor and can be used as an electrolyte for intermediate temperature solid oxide fuel cells (IT-SOFCs). This study aims to ...

  11. Electrical and electrochemical studies on sodium ion-based gel polymer electrolytes

    Science.gov (United States)

    Isa, K. B. Md; Othman, L.; Hambali, D.; Osman, Z.

    2017-09-01

    Gel polymer electrolytes (GPEs) have captured great attention because of their unique properties such as good mechanical stability, high flexibility and high conductivity approachable to that of the liquid electrolytes. In this work, we have prepared sodium ion conducting gel polymer electrolyte (GPE) films consisting of polyvinylidenefluoride-co-hexafluoropropylene (PVdF-HFP) as a polymer host using the solution casting technique. Sodium trifluoromethane- sulfonate (NaCF3SO3) was used as an ionic salt and the mixture of ethylene carbonate (EC) and propylene carbonate (PC) as a plasticizing solvent. Impedance spectroscopy measurements were carried out to determine the ionic conductivity of the GPE films. The sample containing 20 wt.% of NaCF3SO3 salt exhibits the highest room temperature ionic conductivity of 2.50 × 10-3 S cm-1. The conductivity of the GPE films was found to depend on the salt concentration that added to the films. The ionic and cationic transference numbers of GPE films were estimated by DC polarization and the combination of AC and DC polarization method, respectively. The results had shown that both ionic and cationic transference numbers are consistent with the conductivity studies. The electrochemical stability of the GPE films was tested using linear sweep voltammetry (LSV) and the value of working voltage range appears to be high enough to be used as an electrolyte in sodium batteries. The cyclic voltammetry (CV) studies confirmed the sodium ion conduction in the GPE films.

  12. Ion-conducting lithium bis(oxalato)borate-based polymer electrolytes

    Czech Academy of Sciences Publication Activity Database

    Reiter, Jakub; Dominko, R.; Nádherná, Martina; Jakubec, Ivo

    2009-01-01

    Roč. 189, č. 1 (2009), s. 133-138 ISSN 0378-7753 R&D Projects: GA MŠk LC523; GA AV ČR KJB400320701 Institutional research plan: CEZ:AV0Z40320502 Keywords : poly mer electrolyte * 2-ethoxyethyl methacrylate * lithium-ion battery Subject RIV: CG - Electrochemistry Impact factor: 3.792, year: 2009

  13. The presence of nanostructured Al2O3 in PMMA-based gel electrolytes

    Czech Academy of Sciences Publication Activity Database

    Krejza, O.; Velická, Jana; Sedlaříková, M.; Vondrák, Jiří

    2008-01-01

    Roč. 178, č. 2 (2008), s. 774-778 ISSN 0378-7753 R&D Projects: GA AV ČR(CZ) KJB208130604; GA ČR(CZ) GA104/06/1471 Institutional research plan: CEZ:AV0Z40320502 Keywords : poly mer electrolyte * PMMA * ionic conductivity Subject RIV: CG - Electrochemistry Impact factor: 3.477, year: 2008

  14. Ab initio investigation of ground-states and ionic motion in particular in zirconia-based solid-oxide electrolytes

    International Nuclear Information System (INIS)

    Hirschfeld, Julian Arndt

    2012-01-01

    Electrolytes with high ionic conductivity at lower temperatures are the prerequisite for the success of Solid Oxide Fuel Cells (SOFC). One candidate is doped zirconia. In the past, the electrical resistance of zirconia based SOFC electrolytes has mainly been decreased by reducing its thickness. But there are limits to reducing the thickness and one can say that nowadays the normal ways are basically exhausted to further enhance the conductivity of well-known electrolyte materials. Hence, new approaches need to be found to discover windows of enhanced ionic conductivity. This can be achieved by understanding the quantum-mechanical oxygen transport in unconventional configurations of doped zirconia. Therefore, such an understanding is of fundamental importance. In this thesis two approaches are pursued, the investigation of the strain dependent ionic migration in zirconia based electrolytes and the designing of an electrolyte material structure with enhanced and strongly anisotropic ionic conductivity. The first approach expands the elementary understanding of oxygen migration in oxide lattices. The migration barrier of the oxygen ion jumps in zirconia is determined by applying the Density Functional Theory (DFT) calculations in connection with the Nudged Elastic Band (NEB) method. These computations show an unexpected window of decreased migration barriers at high compressive strains. Similar to other publications a decrease in the migration barrier for expansive strain is observed. But, in addition, a migration barrier decrease under high compressive strains is found beyond a maximal height of the migration barrier. A simple analytic model offers an explanation. The drop of the migration barrier at high compressions originates from the elevation of the ground-state energy. This means: Increasing ground state energies becomes an interesting alternative to facilitate ionic mobility. The second approach is based on the idea, that actually, only in the direction of ion

  15. Ab initio investigation of ground-states and ionic motion in particular in zirconia-based solid-oxide electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Hirschfeld, Julian Arndt

    2012-12-11

    Electrolytes with high ionic conductivity at lower temperatures are the prerequisite for the success of Solid Oxide Fuel Cells (SOFC). One candidate is doped zirconia. In the past, the electrical resistance of zirconia based SOFC electrolytes has mainly been decreased by reducing its thickness. But there are limits to reducing the thickness and one can say that nowadays the normal ways are basically exhausted to further enhance the conductivity of well-known electrolyte materials. Hence, new approaches need to be found to discover windows of enhanced ionic conductivity. This can be achieved by understanding the quantum-mechanical oxygen transport in unconventional configurations of doped zirconia. Therefore, such an understanding is of fundamental importance. In this thesis two approaches are pursued, the investigation of the strain dependent ionic migration in zirconia based electrolytes and the designing of an electrolyte material structure with enhanced and strongly anisotropic ionic conductivity. The first approach expands the elementary understanding of oxygen migration in oxide lattices. The migration barrier of the oxygen ion jumps in zirconia is determined by applying the Density Functional Theory (DFT) calculations in connection with the Nudged Elastic Band (NEB) method. These computations show an unexpected window of decreased migration barriers at high compressive strains. Similar to other publications a decrease in the migration barrier for expansive strain is observed. But, in addition, a migration barrier decrease under high compressive strains is found beyond a maximal height of the migration barrier. A simple analytic model offers an explanation. The drop of the migration barrier at high compressions originates from the elevation of the ground-state energy. This means: Increasing ground state energies becomes an interesting alternative to facilitate ionic mobility. The second approach is based on the idea, that actually, only in the direction of ion

  16. Exceptional durability enhancement of PA/PBI based polymer electrolyte membrane fuel cells for high temperature operation at 200°C

    DEFF Research Database (Denmark)

    Aili, David; Zhang, Jin; Jakobsen, Mark Tonny Dalsgaard

    2016-01-01

    The incorporation of phosphotungstic acid functionalized mesoporous silica in phosphoric acid doped polybenzimidazole (PA/PBI) substantially enhances the durability of PA/PBI based polymer electrolyte membrane fuel cells for high temperature operation at 200°C.......The incorporation of phosphotungstic acid functionalized mesoporous silica in phosphoric acid doped polybenzimidazole (PA/PBI) substantially enhances the durability of PA/PBI based polymer electrolyte membrane fuel cells for high temperature operation at 200°C....

  17. A supramolecular gel electrolyte formed from amide based co-gelator for quasi-solid-state dye-sensitized solar cell with boosted electron kinetic processes

    Science.gov (United States)

    Huo, Zhipeng; Wang, Lu; Tao, Li; Ding, Yong; Yi, Jinxin; Alsaedi, Ahmed; Hayat, Tasawar; Dai, Songyuan

    2017-08-01

    A supramolecular gel electrolyte (Tgel > 100 °C) is formed from N,N‧-1,8-octanediylbis-dodecanamide and iodoacetamide as two-component co-gelator, and introduced into the quasi-solid-state dye-sensitized solar cells (QS-DSSCs). The different morphologies of microscopic network between two-component and single-component gel electrolytes have influence on the diffusion of redox couple in gel electrolytes and further affect the electron kinetic processes in QS-DSSCs. Compared with the single-component gel electrolyte, the two-component gel electrolyte has less compact gel network and weaker steric hindrance effect, which provides more effective charge transport channel for the diffusion of I3/I- redox couple. Meanwhile, the sbnd NH2 groups of iodoacetamide molecules interact with Li+ and I3-, which also accelerate the transport of I3-/I- and decrease in the I3- concentration in the TiO2/electrolyte interface. As a result, nearly a 12% improvement in short-circuit photocurrent density (Jsc) and much higher open circuit potential (Voc) are found in the two-component gel electrolyte based QS-DSSC. Consequently, the QS-DSSC based on the supramolecular gel electrolyte obtains a 17% enhancement in the photoelectric conversion efficiency (7.32%) in comparison with the QS-DSSC based on the single-component gel electrolyte (6.24%). Furthermore, the degradations of these QS-DSSCs are negligible after one sun light soaking with UV cutoff filter at 50 °C for 1000 h.

  18. Restricted lithium ion dynamics in PEO-based block copolymer electrolytes measured by high-field nuclear magnetic resonance relaxation

    Science.gov (United States)

    Huynh, Tan Vu; Messinger, Robert J.; Sarou-Kanian, Vincent; Fayon, Franck; Bouchet, Renaud; Deschamps, Michaël

    2017-10-01

    The intrinsic ionic conductivity of polyethylene oxide (PEO)-based block copolymer electrolytes is often assumed to be identical to the conductivity of the PEO homopolymer. Here, we use high-field 7Li nuclear magnetic resonance (NMR) relaxation and pulsed-field-gradient (PFG) NMR diffusion measurements to probe lithium ion dynamics over nanosecond and millisecond time scales in PEO and polystyrene (PS)-b-PEO-b-PS electrolytes containing the lithium salt LiTFSI. Variable-temperature longitudinal (T1) and transverse (T2) 7Li NMR relaxation rates were acquired at three magnetic field strengths and quantitatively analyzed for the first time at such fields, enabling us to distinguish two characteristic time scales that describe fluctuations of the 7Li nuclear electric quadrupolar interaction. Fast lithium motions [up to O (ns)] are essentially identical between the two polymer electrolytes, including sub-nanosecond vibrations and local fluctuations of the coordination polyhedra between lithium and nearby oxygen atoms. However, lithium dynamics over longer time scales [O (10 ns) and greater] are slower in the block copolymer compared to the homopolymer, as manifested experimentally by their different transverse 7Li NMR relaxation rates. Restricted dynamics and altered thermodynamic behavior of PEO chains anchored near PS domains likely explain these results.

  19. Transport Properties Of PbI2 Doped Silver Oxysalt Based Amorphous Solid Electrolytes

    Science.gov (United States)

    Shrisanjaykumar Jayswal, Manishkumar

    Solid electrolytes are a class of materials that conduct electricity by means of motion of ions like Ag+, Na+, Li +, Cu+, H+, F-, O -2 etc. in solid phase. The host materials include crystalline, polycrystalline, glasses, polymers and composites. Ion conducting glasses are one of the most sought after solid electrolytes that are useful in various electrochemical applications like solid state batteries, gas sensors, supercapacitors, electrochromic devices, to name a few. Since the discovery of fast silver ion transport in silver oxyhalide glasses at the end of the 1960s, many glasses showing large ionic conductivity up to 10-4 10-2 S/cm at room temperature have been developed, chiefly silver and copper ion conductors. The silver ion conducting glasses owe their high ionic conductivity mainly to stabilized alpha-AgI. AgI, as we know, undergoes a structural phase transition from wurtzite (beta phase) at room temperature to body centered cubic (alpha phase) structure at temperatures higher than 146 °C. The alpha-AgI possesses approximately six order of higher ionic conductivity than beta-AgI. The high ionic conductivity of alpha-AgI is attributed to its molten sublattice type of structure, which facilitates easy Ag+ ion migration, like a liquid. And hence, several attempts have been made to stabilize it at room temperature in crystalline as well as non-crystalline hosts like oxide and non-oxide glasses. Recently, in order to stabilize AgI in glasses, instead of directly doping it, indirect routes have also been explored. Where, a metal iodide salt along with silver oxide or silver phosphate is taken and an exchange reaction permitted by Hard and Soft, Acid and Base (HSAB) principle occurs between the two and AgI and metal oxide form in the glass forming melt. Work done in the present thesis has been organized in seven chapters as follows: Chapter 1: A review and background information of different solid electrolyte materials and their development is presented. Along

  20. A model-based parametric analysis of a direct ethanol polymer electrolyte membrane fuel cell performance

    Energy Technology Data Exchange (ETDEWEB)

    Andreadis, G.M.; Podias, A.K.M.; Tsiakaras, P.E. [Department of Mechanical and Industrial Engineering, School of Engineering, University of Thessaly, Pedion Areos, 383 34, Volos (Greece)

    2009-10-20

    In the present work, a model-based parametric analysis of the performance of a direct ethanol polymer electrolyte membrane fuel cell (DE-PEMFC) is conducted with the purpose to investigate the effect of several parameters on the cell's operation. The analysis is based on a previously validated one-dimensional mathematical model that describes the operation of a DE-PEMFC in steady state. More precisely, the effect of several operational and structural parameters on (i) the ethanol crossover rate from the anode to the cathode side of the cell, (ii) the parasitic current generation (mixed potential formation) and (iii) the total cell performance is investigated. According to the model predictions it was found that the increase of the ethanol feed concentration leads to higher ethanol crossover rates, higher parasitic currents and higher mixed potential values resulting in the decrease of the cell's power density. However there is an optimum ethanol feed concentration (approximately 1.0 mol L{sup -1}) for which the cell power density reaches its highest value. The platinum (Pt) loading of the anode and the cathode catalytic layers affects strongly the cell performance. Higher values of Pt loading of the catalytic layers increase the specific reaction surface area resulting in higher cell power densities. An increase of the anode catalyst loading compared to an equal one of the cathode catalyst loading has greater impact on the cell's power density. Another interesting finding is that increasing the diffusion layers' porosity up to a certain extent, improves the cell power density despite the fact that the parasitic current increases. This is explained by the fact that the reactants' concentrations over the catalysts are increased, leading to lower activation overpotential values, which are the main source of the total cell overpotentials. Moreover, the use of a thicker membrane leads to lower ethanol crossover rate, lower parasitic current and

  1. A Newly Designed Composite Gel Polymer Electrolyte Based on Poly(Vinylidene Fluoride-Hexafluoropropylene) (PVDF-HFP) for Enhanced Solid-State Lithium-Sulfur Batteries.

    Science.gov (United States)

    Xia, Yan; Wang, Xiuli; Xia, Xinhui; Xu, Ruochen; Zhang, Shengzhao; Wu, Jianbo; Liang, Yanfei; Gu, Changdong; Tu, Jiangping

    2017-10-26

    Developing high-performance solid-state electrolytes is crucial for the innovation of next-generation lithium-sulfur batteries. Herein, a facile method for preparation of a novel gel polymer electrolyte (GPE) based on poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) is reported. Furthermore, Li 1.5 Al 0.5 Ti 1.5 (PO 4 ) 3 (LATP) nanoparticles as the active fillers are uniformly embedded into the GPE to form the final PVDF-HFP/LATP composite gel polymer electrolyte (CPE). Impressively, the obtained CPE demonstrates a high lithium ion transference number of 0.51 and improved electrochemical stability as compared to commercial liquid electrolyte. In addition, the assembled solid-sate Li-S battery with the composite gel polymer electrolyte membrane presents a high initial capacity of 918 mAh g -1 at 0.05 C, and better cycle performance than the counterparts with liquid electrolyte. Our designed PVDF-HFP/LATP composite can be a promising electrolyte for next-generation solid-state batteries with high cycling stability. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Towards A Model-Based Prognostics Methodology For Electrolytic Capacitors: A Case Study Based On Electrical Overstress Accelerated Aging

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper presents a model-driven methodology for predict- ing the remaining useful life of electrolytic capacitors. This methodology adopts a Kalman filter...

  3. A Model-based Prognostics Methodology for Electrolytic Capacitors Based on Electrical Overstress Accelerated Aging

    Data.gov (United States)

    National Aeronautics and Space Administration — A remaining useful life prediction methodology for elec- trolytic capacitors is presented. This methodology is based on the Kalman filter framework and an empirical...

  4. Oxide-based synaptic transistors gated by solution-processed gelatin electrolytes

    Science.gov (United States)

    He, Yinke; Sun, Jia; Qian, Chuan; Kong, Ling-An; Gou, Guangyang; Li, Hongjian

    2017-04-01

    In human brain, a large number of neurons are connected via synapses. Simulation of the synaptic behaviors using electronic devices is the most important step for neuromorphic systems. In this paper, proton conducting gelatin electrolyte-gated oxide field-effect transistors (FETs) were used for emulating synaptic functions, in which the gate electrode is regarded as pre-synaptic neuron and the channel layer as the post-synaptic neuron. In analogy to the biological synapse, a potential spike can be applied at the gate electrode and trigger ionic motion in the gelatin electrolyte, which in turn generates excitatory post-synaptic current (EPSC) in the channel layer. Basic synaptic behaviors including spike time-dependent EPSC, paired-pulse facilitation (PPF), self-adaptation, and frequency-dependent synaptic transmission were successfully mimicked. Such ionic/electronic hybrid devices are beneficial for synaptic electronics and brain-inspired neuromorphic systems.

  5. POLYMER ELECTROLYTE MEMBRANE FUEL CELLS

    DEFF Research Database (Denmark)

    2001-01-01

    A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various thermopl......A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various...... thermoplastic polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes...... electrolyte membrane by hot-press. The fuel cell can operate at temperatures up to at least 200 °C with hydrogen-rich fuel containing high ratios of carbon monoxide such as 3 vol% carbon monoxide or more, compared to the carbon monoxide tolerance of 10-20 ppm level for Nafion$m(3)-based polymer electrolyte...

  6. The Effect of Percutaneous Nephrolithotomy Process on Hemodynamic, Electrolyte and Acid-Base Changes

    Directory of Open Access Journals (Sweden)

    Ercan Baş

    2015-10-01

    Full Text Available Aim: Operation of percutaneous nephrolithotomy (PNL, is the most commonly used method of renal stone surgery. During this operation, kidney must be continually irrigated with isotonic liquid. In our study, we investigated the volume of irrigation, irrigation duration, input the number of percutaneous renal parenchymal thickness and the degree of this finding the effects of on hemodynamic, electrolyte and metabolic changes. Method: 64 patient with an indication for percutaneous nephrolithotomy were included in the study. Before irrigation, during irrigation and the post- irrigation; pulse, systolic and diastolic blood pressure (bp, electrolytes, arterial blood gases were measured. In preoperative and postoperative 1. and 24. hours hemoglobin, creatinine levels were measured. Before the operation; pelvicaliectasis degree, parenchymal thickness, volume and duration of irrigation and the number of percutaneous entry were recorded in all patients. Results: Following the start of irrigation, changes in diastolic and systolic bp and pulse also not statistically significant. No significant change of partial oxygen, carbon dioxide, and oxygen saturation pressure was observed. After the operation, serum sodium, potassium, calcium values are within normal limits, but when compared with preoperative values the decrease of these values statistically significant were observed. Bicarbonate and ph values with irrigation period had a negative correlation. Although not clinically significant parenchymal thickness was found to be negative correlation with decrease of calcium. Additionally degrees of pelvicaliectasis has been found negative correlation with the decrease of sodium and bicarbonate. Conclusion: Hemodynamics and electrolytes did not change significantly both during and after the PNL process, but metabolic acidosis was observed towards the end of the PNL process. In long-term irrigation, repeated percutaneous entrances, people with moderate and severe

  7. Ternary polymer electrolytes with 1-methylimidazole based ionic liquids and aprotic solvents

    Czech Academy of Sciences Publication Activity Database

    Reiter, Jakub; Vondrák, Jiří; Michálek, Jiří; Mička, Z.

    2006-01-01

    Roč. 52, č. 3 (2006), s. 1398-1408 ISSN 0013-4686 R&D Projects: GA MŠk LC523; GA MŽP SN/3/171/05 Institutional research plan: CEZ:AV0Z40320502; CEZ:AV0Z40500505 Keywords : polymer gel electrolyte * ion ic liquids * lithium - ion batteries Subject RIV: CA - Inorganic Chemistry Impact factor: 2.955, year: 2006

  8. Poly(ethyl methacrylate) and poly(2-ethoxyethyl methacrylate) based polymer gel electrolytes

    Czech Academy of Sciences Publication Activity Database

    Reiter, Jakub; Michálek, Jiří; Vondrák, Jiří; Chmelíková, Dana; Přádný, Martin; Mička, Z.

    2006-01-01

    Roč. 158, č. 1 (2006), s. 509-517 ISSN 0378-7753 R&D Projects: GA MŽP(CZ) SN/3/171/05; GA MŠk(CZ) LC523; GA ČR GA104/02/0731 Institutional research plan: CEZ:AV0Z40320502; CEZ:AV0Z40500505 Keywords : poly mer electrolyte * cross-linked poly mer * lithium batteries Subject RIV: CA - Inorganic Chemistry Impact factor: 3.521, year: 2006

  9. Red blood transfusion in preterm infants: changes in glucose, electrolytes and acid base balance

    Directory of Open Access Journals (Sweden)

    Shereen Abdelghaffar

    2012-01-01

    Full Text Available Background: Preterm neonates comprise the most heavily transfused group of patients, and about 85% of extremely low birth weight newborns receive a transfusion by the end of their hospital stay. The aim of this study was to assess the possible metabolic effects of RBC transfusion on preterm infants, especially during the first 2 weeks of life, and its relation to blood volume. Materials and Methods: This study was conducted on 40 preterm neonates with gestational age of less than or equal to 34 weeks. They received RBCs transfusion during first 2 weeks of life. Venous blood samples of infants were collected 2 to 4 hours before and 1 hour after the end of transfusion to evaluate hemoglobin (Hb level, hematocrit, acid-base, electrolytes, and glucose status. Then, infants were classified into two main groups: those who received RBCs volume less than or 20 ml/kg and those who received RBCs volume more than 20 ml/kg. Results: Infants received a mean volume of 20.38 ± 3.2 ml/kg RBCs (range, 10.9 - 26.6 ml/kg at a median age of 9.8 ± 3.6 days. After transfusion, a significant increase of mean Hb (P<0.001, mean Hct (P<0.001, pH (P<0.001, pO 2 (P<0.05, and a significant decrease of the pCO2 (41.46 ± 8.8torr vs 35.4 ± 9.34 torr; P<0.001 were observed. In addition, there was a significant increase of serum K + (P<0.001, and a significant decrease of Ca +2 (P<0.001. A positive correlation was found between the K + intake and the changes of kalemia (r = 0.99; P = 0.00. Furthermore, we observed an inverse correlation between the patients′ calcium intake and the changes of calcemia (r = -0.35; P = 0.02. On comparing the changes in clinical and biochemical variables between two groups after transfusion, we observed a significant increase in mean Hb and Hct associated with a significant decrease in mean serum Ca +2 (P<0.001 in the group receiving the larger blood volume. Conclusion: RBC transfusion was effective in improving anemia, oxygenation, increasing

  10. Structural and optical characterization of PVA:KMnO4 based solid polymer electrolyte

    Directory of Open Access Journals (Sweden)

    Omed Gh. Abdullah

    2016-01-01

    Full Text Available Solid polymer electrolyte films of polyvinyl alcohol (PVA doped with a different weight percent of potassium permanganate (KMnO4 were prepared by standard solution cast method. XRD and FTIR techniques were performed for structural study. Complex formation between the PVA polymer and KMnO4 salt was confirmed by Fourier transform infrared (FTIR spectroscopy. The description of crystalline nature of the solid polymer electrolyte films has been confirmed by XRD analysis. The UV-Visible absorption spectra were analyzed in terms of absorption formula for non-crystalline materials. The fundamental optical parameters such as optical band gap energy, refractive index, optical conductivity, and dielectric constants have been investigated and showed a clear dependence on the KMnO4 concentration. The observed value of optical band gap energy for pure PVA is about 6.27 eV and decreases to a value 3.12 eV for the film sample formed with 4 wt% KMnO4 salt. The calculated values of refractive index and the dielectric constants of the polymer electrolyte films increase with increasing KMnO4 content.

  11. Based on the Theory of TRIZ Solving the Problem of 18650 Battery Electrolyte Filling

    Science.gov (United States)

    Shao-hua, Cui; Jiang-ping, Mei; Ling-hua, Zhang; Xiao, Du

    2017-12-01

    As a type of standardized battery cylindrical 18650 lithium-ion battery is widely used in new energy vehicle industry, It can be produced in large quantities without changing type. Because of its special advantages than others. But due to the pressure of rising capacity, electrolyte filling (which is short for E/L) process has become more and more difficult. While reducing the production efficiency eases the problem of E/L, it also poses performance and security problems. So the issue cannot be solved using the common knowledge of the industry. In this paper, This article does not use lean manufacturing or 6Sigma methods, we use TRIZ theory to analyze the E/L difficulty problem in detail (using causal analysis, technical contradiction analysis, substance - field analysis, physical contradiction analysis and other tools). By creating an atmosphere of vacuum and pressure replace the existing E/L tooling for single cell mechanical structure, through blowing hot air method to increase the temperature of electrolyte, Dissolving the J/R into a electrolyte tank which is full of 0.3Mpa nitrogen. Under the premise of not reducing the production efficiency, at the same time ensuring performance and safety, we try to find out a method to solve the E/L difficulty problem, and would get better application in the construction of new production lines in the new factory.

  12. An all-solid-state electrochemical double-layer capacitor based on a plastic crystal electrolyte

    Directory of Open Access Journals (Sweden)

    Ali eaabouimrane

    2015-08-01

    Full Text Available A plastic crystal, solid electrolyte was prepared by mixing tetrabutylammonium hexafluorophosphate salt, (C4H94NPF6, (10 molar % with succinonitrile, SCN, (N C−CH2−CH2−C N, [SCN-10%TBA-PF6]. The resultant waxy material shows a plastic crystalline phase that extend from -36 °C up to its melting at 23 °C. It shows a high ionic conductivity reaching 4 × 10−5 S/cm in the plastic crystal phase (15 °C and ~ 3 × 10−3 S/cm in the molten state (25 °C. These properties along with the high electrochemical stability rendered the use of this material as an electrolyte in an electrochemical double-layer capacitor (EDLC. The EDLC was assembled and its performance was tested by cyclic voltammetry, AC impedance spectroscopy and galvanostatic charge-discharge methods. Specific capacitance values in the range of 4-7 F/g. (of electrode active material were obtained in the plastic crystal phase at 15 °C, that although compare well with those reported for some polymer electrolytes, can be still enhanced with further development of the device and its components, and only demonstrate their great potential use for capacitors as a new application.

  13. Amperometric detector for gas chromatography based on a silica sol-gel solid electrolyte.

    Science.gov (United States)

    Steinecker, William H; Miecznikowski, Krzysztof; Kulesza, Pawel J; Sandlin, Zechariah D; Cox, James A

    2017-11-01

    An electrochemical cell comprising a silica sol-gel solid electrolyte, a working electrode that protrudes into a gas phase, and reference and counter electrodes that contact the solid electrolyte comprises an amperometric detector for gas chromatography. Under potentiostatic conditions, a current related to the concentration of an analyte in the gas phase is produced by its oxidation at the three-phase boundary among the sol-gel, working electrode, and the gas phase. The sol-gel is processed to contain an electrolyte that also serves as a humidistat to maintain a constant water activity even in the presence the gas chromatographic mobile phase. Response was demonstrated toward a diverse set of analytes, namely hydrogen, 1,2-ethandithiol, phenol, p-cresol, and thioanisole. Using flow injection amperometry of hydrogen with He as the carrier gas, 90% of the steady-state current was achieved in < 1s at a flow rate of 20mLmin -1 . A separation of 1,2-ethandithiol, phenol, p-cresol, and thioanisole at a 2.2mLmin -1 flow rate was achieved with respective detection limits (k = 3 criterion) of 4, 1, 3, and 70 ppmv when the working electrode potential was 800mV. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. The exploration of Lanthanum based perovskites and their complementary electrolytes for the supercapacitor applications

    Science.gov (United States)

    Arjun, Nadarajan; Pan, Guan-Tin; Yang, Thomas C. K.

    In this study, four different kinds of perovskite powders (LaMnO3, LaFeO3, LaCrO3, and LaNiO3) were prepared and investigated as anode materials for supercapacitor. The as-prepared powders were blended with active carbon and subsequently coated on the nickel plates as the collector layer of the supercapacitors. Three different types of the aqueous solutions (3 M KCl, 1 M LiOH, and 3 M LiOH) were respectively served as the electrolytes for the supercapacitor. The morphology and crystalline phase were characterized by transmission electron microscopy and XRD. The electrical capacity and impedance were measured by the electrochemical capacitance voltage analyzer and impedance spectroscopy. The profiles of specific capacitance of the four different anodic electrodes and three different electrolytes were implemented. The impedance results indicated that four asymmetric pseudocapacitors didn't show any Warburg-type line and semi-circle line in the low-frequency region. According to the CV profiles, the intrinsic LaNiO3 exhibits the highest specific capacitance of 106.58 F/g in 3 M LiOH. Furthermore, the 98% of the initial capacitance of LaNiO3 was retained after 500 charge-discharge life cycles at the maximum current density of 1 A/g. The efficient charge storage of LaNiO3 was attributed by the anion intercalated redox reactions along with the suitability of electrode-electrolyte interactions.

  15. Preparation and characterization of core-shell electrodes for application in gel electrolyte-based dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Avellaneda, Cesar O.; Goncalves, Agnaldo D.; Benedetti, Joao E.; Nogueira, Ana F.

    2010-01-01

    Core-shell electrodes based on TiO 2 covered with different oxides were prepared and characterized. These electrodes were applied in gel electrolyte-based dye-sensitized solar cells (DSSC). The TiO 2 electrodes were prepared from TiO 2 powder (P25 Degussa) and coated with thin layers of Al 2 O 3 , MgO, Nb 2 O 5 , and SrTiO 3 prepared by the sol-gel method. The core-shell electrodes were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscopy measurements. J-V curves in the dark and under standard AM 1.5 conditions and photovoltage decay measurements under open-circuit conditions were carried out in order to evaluate the influence of the oxide layer on the charge recombination dynamics and on the device's performance. The results indicated an improvement in the conversion efficiency as a result of an increase in the open circuit voltage. The photovoltage decay curves under open-circuit conditions showed that the core-shell electrodes provide longer electron lifetime values compared to uncoated TiO 2 electrodes, corroborating with a minimization in the recombination losses at the nanoparticle surface/electrolyte interface. This is the first time that a study has been applied to DSSC based on gel polymer electrolyte. The optimum performance was achieved by solar cells based on TiO 2 /MgO core-shell electrodes: fill factor of ∼0.60, short-circuit current density J sc of 12 mA cm -2 , open-circuit voltage V oc of 0.78 V and overall energy conversion efficiency of ∼5% (under illumination of 100 mW cm -2 ).

  16. Ethylene carbonate-free fluoroethylene carbonate-based electrolyte works better for freestanding Si-based composite paper anodes for Li-ion batteries

    Science.gov (United States)

    Yao, K.; Zheng, J. P.; Liang, R.

    2018-03-01

    Fluoroethylene carbonate (FEC)-based electrolytes using FEC as the co-solvent (50 wt%) are investigated and compared with the electrolyte using FEC as the additive (10 wt%) for freestanding Si-carbon nanotubes (CNTs) composite paper anodes for Li-ion batteries. The ethylene carbonate (EC)-free FEC-based electrolyte is found to achieve higher specific capacity and better capacity retention in terms of long-term cycling. After 500 cycles, the capacity retention of the cell using diethyl carbonate (DEC)-FEC (1:1 w/w) is increased by 88% and 60% compared to the cells using EC-DEC-FEC (45:45:10 w/w/w) and EC-FEC (1:1 w/w), respectively. Through SEM-EDX and XPS analyses, a possible reaction route of formation of fluorinated semicarbonates and polyolefins from FEC is proposed. The inferior cell performance related to the EC-containing electrolytes is likely due to the formation of more polyolefins, which do not favor Li ion migration.

  17. An investigation of 2,5-di-tertbutyl-1,4-bis(methoxyethoxy)benzene in ether-based electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Su, Liang; Ferrandon, Magali; Barton, John L.; de la Rosa, Noel Upia; Vaughey, John T.; Brushett, Fikile R.

    2017-08-01

    The identification and development of conductive electrolytes with high concentrations of redox active species is key to realizing energy-dense nonaqueous flow batteries. Herein, we explore the use of ether solvents (1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), diethylene glycol dimethyl ether (DEGDME), and tetraethylene glycol dimethyl ether (TEGDME)) as the basis for redox electrolytes containing a lithium ion supporting salt (LiBF4 or LiTFSI) and 2,5-di-tert-butyl-1,4-bis(2-methoxyethoxy)benzene (DBBB) as an active material. An automated high-throughput platform is employed to screen various electrolyte compositions by measuring solution conductivity and solute solubility as a function of solvent and salt type, component concentration, and temperature. Subsequently, the electrochemical and transport properties of select redox electrolytes are characterized by cyclic voltammetry using glassy carbon disk electrodes and by linear sweep voltammetry using carbon fiber ultramicroelectrodes. In general, improvements in electrolyte conductivity and solute solubility are observed with ether-based formulations as compared to previously reported propylene carbonate (PC)-based formulations. In particular, the addition of DOL to a DME-based electrolyte increases the conductivity and decreases the temperature for solubilization at high LiTFSI and DBBB concentrations. The redox behavior of DBBB remains consistent across the range of concentrations tested while the diffusion coefficient scales with changes in solution viscosity.

  18. Lithium Ion Transport Across and Between Phase Boundaries in Heterogeneous Polymer Electrolytes, Based on PVdF

    National Research Council Canada - National Science Library

    Greenbaum, Steven

    1998-01-01

    .... In the first reported attempt to exploit 17O NMR to study lithium battery electrolytes, we have prepared 17O-enriched Li triflate and several electrolytes containing the isotopically enriched salt...

  19. Solution phase thermodynamics of strong electrolytes based on ionic concentrations, hydration numbers and volumes of dissolved entities

    Czech Academy of Sciences Publication Activity Database

    Heyrovská, Raji

    2013-01-01

    Roč. 24, č. 6 (2013), s. 1895-1901 ISSN 1040-0400 Institutional support: RVO:68081707 Keywords : Solution thermodynamics * Aqueous electrolytes * Partial electrolytic dissociation Subject RIV: BO - Biophysics Impact factor: 1.900, year: 2013

  20. Influences of poly(ether urethane) introduction on poly(ethylene oxide) based polymer electrolyte for solvent-free dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Yanfang; Xiang Wanchun [CAS Key Laboratory of Photochemistry, Institute of Chemistry, BNLMS, Chinese Academy of Sciences, Beijing 100190 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Chen Shen; Fang Shibi; Zhou Xiaowen; Zhang Jingbo [CAS Key Laboratory of Photochemistry, Institute of Chemistry, BNLMS, Chinese Academy of Sciences, Beijing 100190 (China); Lin Yuan [CAS Key Laboratory of Photochemistry, Institute of Chemistry, BNLMS, Chinese Academy of Sciences, Beijing 100190 (China)], E-mail: linyuan@iccas.ac.cn

    2009-11-01

    A poly(ether urethane) (PEUR)/poly(ethylene oxide) (PEO)/SiO{sub 2} based nanocomposite polymer is prepared and employed in the construction of high efficiency all-solid-state dye-sensitized nanocrystalline solar cells. The introduction of low-molecular weight PEUR prepolymer into PEO electrolyte has greatly enhance the electrolyte performance by both improving the interfacial contact properties of electrode/electrolyte and decreasing the PEO crystallization, which were confirmed by XRD and SEM characteristics. The effects of polymer composition, nano SiO{sub 2} content on the ionic conductivity and I{sub 3}{sup -} ions diffusion of polymer-blend electrolyte are investigated. The optimized composition yields an energy conversion efficiency of 3.71% under irradiation by white light (100 mW cm{sup -2})

  1. A Polymer Electrolyte for Dye-Sensitized Solar Cells Based on a Poly(Polyvinylidenefluoride-Co-Hexafluoropropylene)/Hydroxypropyl Methyl Cellulose Blend

    Science.gov (United States)

    Won, Lee Ji; Kim, Jae Hong; Thogiti, Suresh

    2018-03-01

    A novel polymer blend electrolyte for dye-sensitized solar cells (DSSCs) was synthesized by quasi-solidifying a liquid-based electrolyte containing an iodide/triiodide redox couple and supporting salts with a mixture of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and indigenous hydroxypropyl methyl cellulose (HPMC). A high ionic conductivity of 8.8 × 10-4 S cm-1 was achieved after introducing 5 wt% of HPMC with respect to the weight of PVDH-HFP. DSSCs were fabricated using gel polymer blend electrolytes, and the J-V characteristics of the fabricated devices were analyzed. Under optimal conditions, the photovoltaic conversion efficiency of cells with the novel HPMC-blended gel electrolyte (5.34%) was significantly greater than that of cells without HPMC (3.97%).

  2. Oxygen reduction activity of N-doped carbon-based films prepared by pulsed laser deposition

    Science.gov (United States)

    Hakoda, Teruyuki; Yamamoto, Shunya; Kawaguchi, Kazuhiro; Yamaki, Tetsuya; Kobayashi, Tomohiro; Yoshikawa, Masahito

    2010-12-01

    Carbon-based films with nitrogen species on their surface were prepared on a glassy carbon (GC) substrate for application as a non-platinum cathode catalyst for polymer electrolyte fuel cells. Cobalt and carbon were deposited in the presence of N 2 gas using a pulsed laser deposition method and then the metal Co was removed by HCl-washing treatment. Oxygen reduction reaction (ORR) activity was electrochemically determined using a rotating disk electrode system in which the film samples on the GC substrate were replaceable. The ORR activity increased with the temperature of the GC substrate during deposition. A carbon-based film prepared at 600 °C in the presence of N 2 at 66.7 Pa showed the highest ORR activity among the tested samples (0.66 V vs. NHE). This film was composed of amorphous carbons doped with pyridine type nitrogen atoms on its surface.

  3. Cosolvent electrolytes for electrochemical devices

    Energy Technology Data Exchange (ETDEWEB)

    Wessells, Colin Deane; Firouzi, Ali; Motallebi, Shahrokh; Strohband, Sven

    2018-02-13

    A system and method for stabilizing electrodes against dissolution and/or hydrolysis including use of cosolvents in liquid electrolyte batteries for three purposes: the extension of the calendar and cycle life time of electrodes that are partially soluble in liquid electrolytes, the purpose of limiting the rate of electrolysis of water into hydrogen and oxygen as a side reaction during battery operation, and for the purpose of cost reduction.

  4. Cosolvent electrolytes for electrochemical devices

    Energy Technology Data Exchange (ETDEWEB)

    Wessells, Colin Deane; Firouzi, Ali; Motallebi, Shahrokh; Strohband, Sven

    2018-01-23

    A method for stabilizing electrodes against dissolution and/or hydrolysis including use of cosolvents in liquid electrolyte batteries for three purposes: the extension of the calendar and cycle life time of electrodes that are partially soluble in liquid electrolytes, the purpose of limiting the rate of electrolysis of water into hydrogen and oxygen as a side reaction during battery operation, and for the purpose of cost reduction.

  5. Conducting polymer-based counter electrode for a quantum-dot-sensitized solar cell (QDSSC) with a polysulfide electrolyte

    International Nuclear Information System (INIS)

    Yeh, Min-Hsin; Lee, Chuan-Pei; Chou, Chen-Yu; Lin, Lu-Yin; Wei, Hung-Yu; Chu, Chih-Wei; Vittal, R.; Ho, Kuo-Chuan

    2011-01-01

    Highlights: ► This is the first report on the use of conducting polymers as counter electrode catalysts for quantum-dot-sensitized solar cells (QDSSCs). ► Conducting polymer materials, i.e., polythiophene (PT), polypyrrole (PPy), and poly(3,4-ethylenedioxythiophene) (PEDOT) were used to prepare counter electrodes for QDSSCs. ► The influences of morphology of the PEDOT-based counter electrode (CE) on the performance of its QDSSC were studied. ► PEDOT electrode exhibits well electrocatalytic activity and stability in the polysulfide electrolyte. ► The efficiency for the QDSSC with PEDOT-CE (1.35%) is comparable to that of the cell with sputtered-Au CE (1.33%). - Abstract: Conducting polymer materials, i.e., polythiophene (PT), polypyrrole (PPy), and poly(3,4-ethylenedioxythiophene) (PEDOT) were used to prepare counter electrodes (CEs) for quantum-dot-sensitized solar cells (QDSSCs). The QDSSC with PEDOT-CE exhibited the highest solar-to-electricity conversion efficiency (η) of 1.35%, which is remarkably higher than those of the cells with PT-CE (0.09%) and PPy-CE (0.41%) and very slightly higher than that of the cell with sputtered-gold-CE (1.33%). Electrochemical impedance spectra (EIS) show that this highest conversion efficiency of the PEDOT-based cell is due to higher electrocatalytic activity and reduced charge transfer resistance at the interface of the CE and the electrolyte, compared to those in the case of the cells with other conducting polymers and bare Au. Furthermore, the influences of morphology of the PEDOT film and the charge passed for its electropolymerization on the performance of its QDSSC were also studied. The higher porosity and surface roughness of the PEDOT matrix, with reference to those of other polymers are understood to be the reason for PEDOT to possess higher electrocatalytic activity at its interface with electrolyte.

  6. Heteroaromatic-based electrolytes for lithium and lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Gang; Abraham, Daniel P.

    2017-04-18

    The present invention provides an electrolyte for lithium and/or lithium-ion batteries comprising a lithium salt in a liquid carrier comprising heteroaromatic compound including a five-membered or six-membered heteroaromatic ring moiety selected from the group consisting of a furan, a pyrazine, a triazine, a pyrrole, and a thiophene, the heteroaromatic ring moiety bearing least one carboxylic ester or carboxylic anhydride substituent bound to at least one carbon atom of the heteroaromatic ring. Preferred heteroaromatic ring moieties include pyridine compounds, pyrazine compounds, pyrrole compounds, furan compounds, and thiophene compounds.

  7. Mixed solid device based on conducting polymer composite and polymer electrolyte

    OpenAIRE

    Neves, Silmara; Fonseca, Carla P.

    2004-01-01

    Tetraethyl orthosilicate (TEOS) derived sol-gel porous films have been utilized as template for the electrochemical polymerization of aniline. Polyaniline-silica composites were obtained and the redox behavior and charge/discharge capacities of a lithium polymeric battery using poly (dimethylsiloxane- co-ethylene oxide) as gel polymeric electrolyte, were investigated. The composite presented a high initial capacity (140 mA h g-1) and a reversible capacity of 75 mA h g-1 after 100 charge/disch...

  8. Toward garnet electrolyte–based Li metal batteries: An ultrathin, highly effective, artificial solid-state electrolyte/metallic Li interface

    Science.gov (United States)

    Fu, Kun (Kelvin); Gong, Yunhui; Liu, Boyang; Zhu, Yizhou; Xu, Shaomao; Yao, Yonggang; Luo, Wei; Wang, Chengwei; Lacey, Steven D.; Dai, Jiaqi; Chen, Yanan; Mo, Yifei; Wachsman, Eric; Hu, Liangbing

    2017-01-01

    Solid-state batteries are a promising option toward high energy and power densities due to the use of lithium (Li) metal as an anode. Among all solid electrolyte materials ranging from sulfides to oxides and oxynitrides, cubic garnet–type Li7La3Zr2O12 (LLZO) ceramic electrolytes are superior candidates because of their high ionic conductivity (10−3 to 10−4 S/cm) and good stability against Li metal. However, garnet solid electrolytes generally have poor contact with Li metal, which causes high resistance and uneven current distribution at the interface. To address this challenge, we demonstrate a strategy to engineer the garnet solid electrolyte and the Li metal interface by forming an intermediary Li-metal alloy, which changes the wettability of the garnet surface (lithiophobic to lithiophilic) and reduces the interface resistance by more than an order of magnitude: 950 ohm·cm2 for the pristine garnet/Li and 75 ohm·cm2 for the surface-engineered garnet/Li. Li7La2.75Ca0.25Zr1.75Nb0.25O12 (LLCZN) was selected as the solid-state electrolyte (SSE) in this work because of its low sintering temperature, stabilized cubic garnet phase, and high ionic conductivity. This low area-specific resistance enables a solid-state garnet SSE/Li metal configuration and promotes the development of a hybrid electrolyte system. The hybrid system uses the improved solid-state garnet SSE Li metal anode and a thin liquid electrolyte cathode interfacial layer. This work provides new ways to address the garnet SSE wetting issue against Li and get more stable cell performances based on the hybrid electrolyte system for Li-ion, Li-sulfur, and Li-oxygen batteries toward the next generation of Li metal batteries. PMID:28435874

  9. Steam Electrolysis by Proton-Conducting Solid Oxide Electrolysis Cells (SOECs) with Chemically Stable BaZrO3-Based Electrolytes

    KAUST Repository

    Bi, Lei

    2015-07-17

    BaZrO3-based material was applied as the electrolyte for proton-conducting solid oxide fuel cells (SOECs). Compared with the instability of BaCeO3-based proton-conductors, BaZrO3-based material could be a more promising candidate for proton-conducting SOECs due to its excellent chemical stability under H2O conditions, but few reports on this aspect has been made due to the processing difficulty for BaZrO3. Our recent pioneering work has demonstrated the feasibility of using BaZrO3-based electrolyte for SOECs and the fabricated cell achieves relatively high cell performance, which is comparable or even higher than that for BaCeO3-based SOECs and offers better chemical stability. Cell performance can be further improved by tailoring the electrolyte and electrode. © The Electrochemical Society.

  10. A New Class of P(VdF-HFP-CeO2-LiClO4-Based Composite Microporous Membrane Electrolytes for Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    G. Vijayakumar

    2011-01-01

    Full Text Available Composite microporous membranes based on Poly (vinylidene fluoride–co-hexafluoro propylene P(VdF-co-HFP-CeO2 were prepared by phase inversion and preferential polymer dissolution process. It was then immersed in 1M LiClO4-EC/DMC (v/v=1:1 electrolyte solution to obtain their corresponding composite microporous membrane electrolytes. For comparison, composite membrane electrolytes were also prepared by conventional phase inversion method. The surface morphology of composite membranes obtained by both methods was examined by FE-SEM analysis, and their thermal behaviour was investigated by DSC analysis. It was observed that the preferential polymer dissolution composite membrane electrolytes (PDCMEs had better properties, such as higher porosity, electrolyte uptake (216 wt%, ionic conductivity (3.84 mS⋅cm−1 and good electrochemical stability (4.9 V, than the phase inversion composite membrane electrolytes (PICMEs. As a result, a cell fabricated with PDCME in between mesocarbon microbead (MCMB anode and LiCoO2 cathode had better cycling performance than a cell fabricated with PICME.

  11. Durable and self-hydrating tungsten carbide-based composite polymer electrolyte membrane fuel cells.

    Science.gov (United States)

    Zheng, Weiqing; Wang, Liang; Deng, Fei; Giles, Stephen A; Prasad, Ajay K; Advani, Suresh G; Yan, Yushan; Vlachos, Dionisios G

    2017-09-04

    Proton conductivity of the polymer electrolyte membranes in fuel cells dictates their performance and requires sufficient water management. Here, we report a simple, scalable method to produce well-dispersed transition metal carbide nanoparticles. We demonstrate that these, when added as an additive to the proton exchange Nafion membrane, provide significant enhancement in power density and durability over 100 hours, surpassing both the baseline Nafion and platinum-containing recast Nafion membranes. Focused ion beam/scanning electron microscope tomography reveals the key membrane degradation mechanism. Density functional theory exposes that OH• and H• radicals adsorb more strongly from solution and reactions producing OH• are significantly more endergonic on tungsten carbide than on platinum. Consequently, tungsten carbide may be a promising catalyst in self-hydrating crossover gases while retarding desorption of and capturing free radicals formed at the cathode, resulting in enhanced membrane durability.The proton conductivity of polymer electrolyte membranes in fuel cells dictates their performance, but requires sufficient water management. Here, the authors report a simple method to produce well-dispersed transition metal carbide nanoparticles as additives to enhance the performance of Nafion membranes in fuel cells.

  12. Synthesis and Ionic Conductivity of Siloxane Based Polymer Electrolytes with Propyl Butyrate Pendant Groups

    International Nuclear Information System (INIS)

    Jalagonia, Natia; Tatrishvili, Tamara; Markarashvili, Eliza; Aneli, Jimsher; Mukbaniani, Omar; Grazulevicius, Jouzas Vidas

    2016-01-01

    Hydrosilylation reactions of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl butyrate catalyzed by Karstedt's, H2PtCl6 and Pt/C catalyst were studied and 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane was obtained. The reaction order, activation energies and rate constants were determined. Ringopening polymerization of 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane in the presence of CaF2, LiF, KF and anhydrous potassium hydroxide in 60-70 .deg. C temperature range was carried out and methylsiloxane oligomers with regular arrangement of propyl butyrate pendant groups were obtained. The synthesized products were studied by FTIR and NMR spectroscopy. The polysiloxanes were characterized by wide-angle X-ray, gel-permeation chromatography and DSC analyses. Via sol-gel processes of oligomers doped with lithium trifluoromethylsulfonate or lithium bis (trifluoromethylsulfonyl)imide, solid polymer electrolyte membranes were obtained. The dependences of ionic conductivity of obtained polyelectrolytes on temperature and salt concentration were investigated, and it was shown that electric conductivity of the polymer electrolyte membranes at room temperature changed in the range 3.5x10 -4 - 6.4xa0 -7 S/cm

  13. Synthesis and Ionic Conductivity of Siloxane Based Polymer Electrolytes with Propyl Butyrate Pendant Groups

    Energy Technology Data Exchange (ETDEWEB)

    Jalagonia, Natia; Tatrishvili, Tamara; Markarashvili, Eliza; Aneli, Jimsher; Mukbaniani, Omar [Javakhishvili Tbilisi State University, Tbilisi (Georgia); Grazulevicius, Jouzas Vidas [Kaunas University of Technology, Kaunas (Lithuania)

    2016-02-15

    Hydrosilylation reactions of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl butyrate catalyzed by Karstedt's, H2PtCl6 and Pt/C catalyst were studied and 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane was obtained. The reaction order, activation energies and rate constants were determined. Ringopening polymerization of 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane in the presence of CaF2, LiF, KF and anhydrous potassium hydroxide in 60-70 .deg. C temperature range was carried out and methylsiloxane oligomers with regular arrangement of propyl butyrate pendant groups were obtained. The synthesized products were studied by FTIR and NMR spectroscopy. The polysiloxanes were characterized by wide-angle X-ray, gel-permeation chromatography and DSC analyses. Via sol-gel processes of oligomers doped with lithium trifluoromethylsulfonate or lithium bis (trifluoromethylsulfonyl)imide, solid polymer electrolyte membranes were obtained. The dependences of ionic conductivity of obtained polyelectrolytes on temperature and salt concentration were investigated, and it was shown that electric conductivity of the polymer electrolyte membranes at room temperature changed in the range 3.5x10{sup -4} - 6.4xa0{sup -7} S/cm.

  14. Preparation and characterization of a Polyacrylonitrile based gel polymer electrolyte for redox capacitors

    Directory of Open Access Journals (Sweden)

    C.M. Bandaranayake

    2016-06-01

    Full Text Available In this study, a gel polymer electrolyte (GPE consisting with polyacrylonitrile (PAN, ethylene carbonate (EC, propylene carbonate (PC and magnesium trifluromethane sulfonate (Mg(CF3SO32 was prepared using the hot pressed method. The starting materials were heated at 130 oC for 2 hours and the resulting hot viscous mixture was pressed in between two well cleaned glass plates. The composition was fine-tuned by varying the salt and the polymer concentration in order to obtain a mechanically stable, thin and flexible film with a high ionic conductivity. It was found that the composition, 105 PAN : 150 MgTF : 400 EC : 400 PC gives the maximum conductivity of 1.06 x 10-2 Scm-1. DC polarization test done with blocking electrodes confirmed the ionic nature of the sample while the results obtained with non-blocking electrodes proved that the anionic contribution for the conductivity is dominant. The sample was used in redox capacitors having two identical polypyrrole electrodes doped with dodecylbenzesulfonate. Cyclic Voltammetry, Galvanostatic Charge Discharge and Electrochemical Impedance Spectroscopy techniques were used to evaluate the performance of the redox capacitors. The specific capacitance was high at low scan rates. The electrolyte was quite stable when use in the redox capacitors. Further, redox capacitor was having a good cycleability which is one of the important key issues to be considered for practical applications.

  15. Proton conducting polymer electrolyte based on plasticized chitosan-PEO blend and application in electrochemical devices

    Science.gov (United States)

    Shukur, M. F.; Ithnin, R.; Illias, H. A.; Kadir, M. F. Z.

    2013-08-01

    Plasticized chitosan-poly(ethylene oxide) (PEO) doped with ammonium nitrate (NH4NO3) electrolyte films are prepared by the solution cast technique. From Fourier transform infrared (FTIR) spectroscopy analysis, hydroxyl band of pure chitosan film is shifted from 3354 to 3425 cm-1 when blended with PEO. On addition of 40 wt.% NH4NO3, new peaks at 3207 cm-1 and 3104 cm-1 appear in the hydroxyl band region, indicating the polymer-salt complexation. The carboxamide and amine bands are observed to shift to 1632 and 1527 cm-1, respectively. The interaction of chitosan-PEO-NH4NO3-EC can be observed by the appearance of the doublet Cdbnd O stretching band of EC. The sample with 70 wt.% ethylene carbonate (EC) exhibits the highest room temperature conductivity of (2.06 ± 0.39) × 10-3 S cm-1. This result is further verified by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) studies. Proton battery is fabricated and shows an open circuit potential (OCP) of (1.66 ± 0.02) V and average discharge capacity at (48.0 ± 5.0) mA h. The maximum power density of the fabricated cell is (9.73 ± 0.75) mW cm-2. The polymer electrolyte is also employed as separator in electrical double layer capacitor (EDLC) and is cycled for 140 times at room temperature.

  16. Influence of thermal post-curing on the degradation of a cross-linked polybenzimidazole-based membrane for high temperature polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Ossiander, T.; Perchthaler, M.; Heinzl, C.; Scheu, C.

    2014-12-01

    The lifetime stability of membranes is one of the main requirements regarding reliability of high temperature polymer electrolyte membrane fuel cells. The present work has improved durability under cycled operation by thermal post-curing of cross-linked polybenzimidazole (PBI)-based membranes. The membranes were dried over 1, 2 and 3 h at 250 °C under air. Ex-situ experiments proved an increase in stability by post-curing. The liquid uptake and swelling in phosphoric acid increased with longer curing periods. The effect of thermal treatments on cycle stability, lifetime and begin-of-life performance of the membrane electrode assemblies (MEAs) was investigated. Longer post-curing periods of the membranes had no influence on the MEAs' begin-of-life performance and constant current behavior over 2300 h. However, the 3 h post-cured MEAs showed enhanced cycle stability. Post-mortem analysis was carried out to identify the occurring degradation mechanisms. While a significant loss of phosphoric acid and a reduction of electrochemical surface activity on the cathode were observed for both post-cured MEAs, the 3 h dried membrane sample had a significantly higher resistance against pinhole formation during the long term test. Altogether, this work presents thermal post-curing as a promising method for the reduction of degradation determining effects in fuel cell membranes.

  17. Poly(Acrylic acid–Based Hybrid Inorganic–Organic Electrolytes Membrane for Electrical Double Layer Capacitors Application

    Directory of Open Access Journals (Sweden)

    Chiam-Wen Liew

    2016-05-01

    Full Text Available Nanocomposite polymer electrolyte membranes (NCPEMs based on poly(acrylic acid(PAA and titania (TiO2 are prepared by a solution casting technique. The ionic conductivity of NCPEMs increases with the weight ratio of TiO2.The highest ionic conductivity of (8.36 ± 0.01 × 10−4 S·cm−1 is obtained with addition of 6 wt % of TiO2 at ambient temperature. The complexation between PAA, LiTFSI and TiO2 is discussed in Attenuated total reflectance-Fourier Transform Infrared (ATR-FTIR studies. Electrical double layer capacitors (EDLCs are fabricated using the filler-free polymer electrolyte or the most conducting NCPEM and carbon-based electrodes. The electrochemical performances of fabricated EDLCs are studied through cyclic voltammetry (CV and galvanostatic charge-discharge studies. EDLC comprising NCPEM shows the specific capacitance of 28.56 F·g−1 (or equivalent to 29.54 mF·cm−2 with excellent electrochemical stability.

  18. Enhancement of Oxygen Reduction and Mitigation of Ionomer Dry-Out Using Insoluble Heteropoly Acids in Intermediate Temperature Polymer-Electrolyte Membrane Fuel Cells

    OpenAIRE

    Alessandro Stassi; Irene Gatto; Ada Saccà; Vincenzo Baglio; Antonino S. Aricò

    2015-01-01

    The use of Cs 0.5 H 0.5 PW 12 O 40 insoluble salt as a superacid promoter in the catalyst layer of a polymer electrolyte membrane fuel cell (PEMFC) has been investigated. An increase of performance has been recorded at intermediate temperatures (110–130 °C) and under low relative humidity (R.H.). The promoter appears to mitigate the ionomer dry-out effects in the catalytic layer and produces an increase of the extent of the catalyst-electrolyte interface as demonstrated by cyclic voltammetry ...

  19. alumina solid electrolyte

    Indian Academy of Sciences (India)

    -β/β -alumina; solid electrolyte; calcium impurity; specific resistance. 1. Introduction. Since its development in the 1980s, the Na/S battery has been one of the most promising candidates for energy storage applications. The Na/S battery functions based on the elec- trochemical reaction between sodium and sulphur to form.

  20. Model Reduction of Switched Systems Based on Switching Generalized Gramians

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza; Wisniewski, Rafal

    2012-01-01

    In this paper, a general method for model order reduction of discrete-time switched linear systems is presented. The proposed technique uses switching generalized gramians. It is shown that several classical reduction methods can be developed into the generalized gramian framework for the model...... reduction of linear systems and for the reduction of switched systems. Discrete-time balanced reduction within a specified frequency interval is taken as an example within this framework. To avoid numerical instability and to increase the numerical efficiency, a generalized gramian-based Petrov...

  1. Polymer Electrolytes for Lithium/Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    The Nam Long Doan

    2012-08-01

    Full Text Available This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes.

  2. Electrolyte salts for nonaqueous electrolytes

    Science.gov (United States)

    Amine, Khalil; Zhang, Zhengcheng; Chen, Zonghai

    2012-10-09

    Metal complex salts may be used in lithium ion batteries. Such metal complex salts not only perform as an electrolyte salt in a lithium ion batteries with high solubility and conductivity, but also can act as redox shuttles that provide overcharge protection of individual cells in a battery pack and/or as electrolyte additives to provide other mechanisms to provide overcharge protection to lithium ion batteries. The metal complex salts have at least one aromatic ring. The aromatic moiety may be reversibly oxidized/reduced at a potential slightly higher than the working potential of the positive electrode in the lithium ion battery. The metal complex salts may also be known as overcharge protection salts.

  3. Ionic liquid electrolytes based on multi-methoxyethyl substituted ammoniums and perfluorinated sulfonimides: Preparation, characterization, and properties

    International Nuclear Information System (INIS)

    Han Hongbo; Liu Kai; Feng Shaowei; Zhou Sisi; Feng Wenfang; Nie Jin; Li Hong; Huang Xuejie; Matsumoto, Hajime; Armand, Michel; Zhou Zhibin

    2010-01-01

    Graphical abstract: New functionalized ionic liquids based on multi-methoxyethyl substituted quaternary ammonium cations and perfluorinated sulfonimide anions are introduced. -- Abstract: New functionalized ionic liquids (ILs), comprised of multi-methoxyethyl substituted quaternary ammonium cations (i.e. [N(CH 2 CH 2 OCH 3 ) 4-n (R) n ] + ; n = 1, R = CH 3 OCH 2 CH 2 ; n = 1, R = CH 3 , CH 2 CH 3 ; n = 2, R = CH 3 CH 2 ), and two representative perfluorinated sulfonimide anions (i.e. bis(fluorosulfonyl)imide (FSI - ) and bis(trifluoromethanesulfonyl)imide (TFSI - )), were prepared. Their fundamental properties, including phase transition, thermal stability, viscosity, density, specific conductivity and electrochemical window, were extensively characterized. These multi-ether functionalized ionic liquids exhibit good capability of dissolving lithium salts. Their binary electrolytes containing high concentration of the corresponding lithium salt ([Li + ] >1.6 mol kg -1 ) show Li + ion transference number (t Li + ) as high as 0.6-0.7. Their electrochemical stability allows Li deposition/stripping realized at room temperature. The desired properties of these multi-ether functionalized ionic liquids make them potential electrolytes for Li (or Li-ion) batteries.

  4. Anthraquinone derivative as high-performance anode material for sodium-ion batteries using ether-based electrolytes

    Directory of Open Access Journals (Sweden)

    Linqin Mu

    2018-01-01

    Full Text Available Organic materials, especially the carbonyl compounds, are promising anode materials for room temperature sodium-ion batteries owing to their high reversible capacity, structural diversity as well as eco-friendly synthesis from bio-mass. Herein, we report a novel anthraquinone derivative, C14H6O4Na2 composited with carbon nanotube (C14H6O4Na2-CNT, used as an anode material for sodium-ion batteries in ether-based electrolyte. The C14H6O4Na2-CNT electrode delivers a reversible capacity of 173 mAh g−1 and an ultra-high initial Coulombic efficiency of 98% at the rate of 0.1 C. The capacity retention is 82% after 50 cycles at 0.2 C and a good rate capability is displayed at 2 C. Furthermore, the average Na insertion voltage of 1.27 V vs. Na+/Na makes it a unique and safety battery material, which would avoid Na plating and formation of solid electrolyte interface. Our contribution provides new insights for designing developed organic anode materials with high initial Coulombic efficiency and improved safety capability for sodium-ion batteries.

  5. Activated carbon and single-walled carbon nanotube based electrochemical capacitor in 1 M LiPF{sub 6} electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Azam, M.A., E-mail: asyadi@utem.edu.my [Carbon Research Technology Research Group, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka (Malaysia); Jantan, N.H.; Dorah, N.; Seman, R.N.A.R.; Manaf, N.S.A. [Carbon Research Technology Research Group, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka (Malaysia); Kudin, T.I.T. [Ionics Materials & Devices Research Laboratory, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, Selangor (Malaysia); Yahya, M.Z.A. [Ionics Materials & Devices Research Laboratory, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, Selangor (Malaysia); National Defence University of Malaysia, Kem Sungai Besi, 57000 Kuala Lumpur (Malaysia)

    2015-09-15

    Highlights: • Activated carbon and single-walled CNT based electrochemical capacitor. • Electrochemical analysis by means of CV, charge/discharge and impedance. • 1 M LiPF{sub 6} non-aqueous solution as an electrolyte. • AC/SWCNT electrode exhibits a maximum capacitance of 60.97 F g{sup −1}. - Abstract: Carbon nanotubes have been extensively studied because of their wide range of potential application such as in nanoscale electric circuits, textiles, transportation, health, and the environment. Carbon nanotubes feature extraordinary properties, such as electrical conductivities higher than those of copper, hardness and thermal conductivity higher than those of diamond, and strength surpassing that of steel, among others. This research focuses on the fabrication of an energy storage device, namely, an electrochemical capacitor, by using carbon materials, i.e., activated carbon and single-walled carbon nanotubes, of a specific weight ratio as electrode materials. The electrolyte functioning as an ion carrier is 1 M lithium hexafluorophosphate. Variations in the electrochemical performance of the device, including its capacitance, charge/discharge characteristics, and impedance, are reported in this paper. The electrode proposed in this work exhibits a maximum capacitance of 60.97 F g{sup −1} at a scan rate of 1 mV s{sup −1}.

  6. A Metal-Organic-Framework-Based Electrolyte with Nanowetted Interfaces for High-Energy-Density Solid-State Lithium Battery.

    Science.gov (United States)

    Wang, Ziqi; Tan, Rui; Wang, Hongbin; Yang, Luyi; Hu, Jiangtao; Chen, Haibiao; Pan, Feng

    2018-01-01

    Solid-state batteries (SSBs) are promising for safer energy storage, but their active loading and energy density have been limited by large interfacial impedance caused by the poor Li + transport kinetics between the solid-state electrolyte and the electrode materials. To address the interfacial issue and achieve higher energy density, herein, a novel solid-like electrolyte (SLE) based on ionic-liquid-impregnated metal-organic framework nanocrystals (Li-IL@MOF) is reported, which demonstrates excellent electrochemical properties, including a high room-temperature ionic conductivity of 3.0 × 10 -4 S cm -1 , an improved Li + transference number of 0.36, and good compatibilities against both Li metal and active electrodes with low interfacial resistances. The Li-IL@MOF SLE is further integrated into a rechargeable Li|LiFePO 4 SSB with an unprecedented active loading of 25 mg cm -2 , and the battery exhibits remarkable performance over a wide temperature range from -20 up to 150 °C. Besides the intrinsically high ionic conductivity of Li-IL@MOF, the unique interfacial contact between the SLE and the active electrodes owing to an interfacial wettability effect of the nanoconfined Li-IL guests, which creates an effective 3D Li + conductive network throughout the whole battery, is considered to be the key factor for the excellent performance of the SSB. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Ionic conductivity in poly(vinyl butyral) based polymeric electrolytes. Effect of solvents and salts

    Energy Technology Data Exchange (ETDEWEB)

    Gopal, Shaleen; Agnihotry, S.A. [National Physical Laboratory, New Delhi (India); Gupta, V.D. [Lucknow University, Lucknow (India)

    1996-10-29

    Li{sup +} conductive solid polymeric electrolytes (SPEs) have been prepared by complexing Li salts LiX (X=I, SCN, CLO4, CF3SO3) with poly (vinyl butyral) (PVB) an amorphous polymer with a low T{sub g} value and well known for its outstanding laminating properties. These self-supporting SPEs have been prepared by the solution cast technique using cyclohexanone, tetrahydrofuran, and n-butyl alcohol as solvents. The XRD and DSC investigations correlated to measured ionic conductivities have revealed that in addition to the amorphous nature of the resulting complex, its T{sub g} value, the concentration and the values of the lattice energies of the complexing salts, the solvent used in making the SPEs also govern the value of ionic conductivity. Highest ionic conductivity values attained in SPEs made with n-butyl alcohol are explained in terms of the interception of the hydrogen bonding due to solvation

  8. SPPSU-based hybrid proton conducting polymeric electrolytes for intermediate temperature PEMFCs

    Energy Technology Data Exchange (ETDEWEB)

    Licoccia, Silvia; Di Vona, M. Luisa; D' Epifanio, Alessandra; Ahmed, Zakarya; Bellitto, Serafina; Marani, Debora; Mecheri, Barbara; de Bonis, Catia; Traversa, Enrico [Department of Chemical Science and Technology, University of Rome Tor Vergata, via della Ricerca Scientifica 1, 00133 Rome (Italy); Trombetta, Marcella [Interdisciplinary Center for Biomedical Research (CIR), Laboratory of Biomaterials, Universita ' ' Campus Bio-Medico' ' , via E. Longoni 83, 00155 Rome (Italy)

    2007-05-01

    Polyphenylsulfone (PPSU) was reacted with SiCl{sub 4} to afford silylated telechelic polymers having different inorganic content, which were sulfonated to different degrees (0.05 {<=} DS {<=} 2) using H{sub 2}SO{sub 4} or ClSO{sub 3}Si(CH{sub 3}){sub 3}. A class II organic-inorganic hybrid polymer was then synthesized via cross-linking through Si-O-Si bonds generated by non-hydrolytic sol-gel reactions. The physicochemical properties of the hybrid were suitable for the preparation of self-standing, flexible and homogeneous membranes which were characterized ATR/FTIR spectroscopy demonstrating the formation of covalent bonds between the organic and inorganic components and the absence of dispersed inorganic silicon. The electrochemical performance was analyzed by electrochemical impedance spectroscopy which showed adequately high conductivity values to make the hybrid polymer a suitable candidate for application as electrolyte in PEMFCs operating at T > 100 C. (author)

  9. RE/H2 Production Micro-System Based on Standard Alkaline Electrolytic Technology

    International Nuclear Information System (INIS)

    Moschetto, A.; Tina, G.M.; Ferraro, M.; Briguglio, N.; Antonucci, V.

    2006-01-01

    This paper presents the first task of a more comprehensive research project focused on the development of micro-scale (1-20 kW) Renewable Hydrogen (RE/H 2 ) production systems oriented to carry on a wide campaign of educational and demonstration projects. The paper proposes to rely on low-cost and rugged 'standard' alkaline electrolytic technology, well suited for decentralized hydrogen production, but requiring a certain R and D effort to get technical competitiveness. An electrolyser test facility has been designed and carried out. Then performance assessment of a commercial electrolyser and its sub-systems has been accomplished. First experimental results stated that the unit under test gets an average production efficiency of 51%, versus a stack (cell) efficiency of about 62%, while the aged AC/DC power converter, to be removed or replaced to adapt the unit to DC link with renewables, requires more than 16% of the incoming power. (authors)

  10. Mixed solid device based on conducting polymer composite and polymer electrolyte

    Directory of Open Access Journals (Sweden)

    Neves Silmara

    2004-01-01

    Full Text Available Tetraethyl orthosilicate (TEOS derived sol-gel porous films have been utilized as template for the electrochemical polymerization of aniline. Polyaniline-silica composites were obtained and the redox behavior and charge/discharge capacities of a lithium polymeric battery using poly (dimethylsiloxane- co-ethylene oxide as gel polymeric electrolyte, were investigated. The composite presented a high initial capacity (140 mA h g-1 and a reversible capacity of 75 mA h g-1 after 100 charge/discharge cycles. The decrease in the specific capacity was attributed to an increase in charge transfer resistance and a decrease in the diffusion coefficient measured by electrochemical impedance spectroscopy.

  11. Performance of titanium dioxide-based cathodes in a lithium polymer electrolyte cell

    Energy Technology Data Exchange (ETDEWEB)

    Macklin, W.J. (Applied Electrochemistry Dept., AEA Industry Technology, Harwell (United Kingdom)); Neat, R.J. (Applied Electrochemistry Dept., AEA Industry Technology, Harwell (United Kingdom))

    Performance data on two polymorphs of titanium dioxide (anatase and rutile) operating in a lithium polymer electrolyte cell at 120 C are presented. On the first discharge lithium ions can be electrochemically inserted into both forms to an approximate composition LiTiO[sub 2]. However, only the rutile material cycles with a significant capacity ([proportional to] 0.5 Li/TiO[sub 2]) with an average cell voltage of 1.73 V corresponding to a theoretical energy density of [proportional to] 290 W h kg[sup -1]. Our results are in contrast to earlier work reported on the intercalation of lithium into these phases at room temperature, where only the anatase form was found to intercalate lithium. X-ray diffraction data indicate that the rutile form undergoes a structural change during the first discharge resulting in the formation of a hexagonal form of LiTiO[sub 2].

  12. Multiple Fault Diagnosis Research on Motors in Aluminum Electrolytic Based on ICA Feature Extraction

    Directory of Open Access Journals (Sweden)

    Jiejia Li

    2014-08-01

    Full Text Available Motors as the actuator in the aluminum electrolysis process, mainly used for control the lifting of the anode to control the cell voltage, make the electrolytic tank keep in the best condition, once the motors failed, slot voltage will be out of control. This paper study on the fault of the motors in the process of aluminum electrolysis. In this paper adopts the EMD algorithm for various stator current signal data preprocessing, it has high adaptive decomposition ability and good ability, and then use the ICA algorithm extract feature of the current which has been denied. The extracted features input to the rough neural network for fault diagnosis and classification and gives the results of fault diagnosis. Through the simulation and analysis verify the feasibility and superiority of this model.

  13. Free-volume structure of fluoropolymer-based radiation-grafted electrolyte membranes investigated by positron annihilation lifetime spectroscopy

    International Nuclear Information System (INIS)

    Sawada, S; Maekawa, Y; Kawasuso, A; Maekawa, M; Yabuuchi, A

    2010-01-01

    In the field of polymer-electrolyte-membrane (PEM) fuel cell technology, the structures of free-volume holes in the PEMs are very important because they are correlated to the supplied-gas crossover phenomenon, which sometimes deteriorates the cell performance. In this study, we investigated the size and location of free-volume holes in the crosslinked-polytetrafluoroethylene (cPTFE) based radiation-grafted PEMs by positron annihilation lifetime (PAL) spectroscopy. For comparison, the base cPTFE and polystyrene grafted films were also measured. From the analysis of PAL spectra, it was found that there were free-volume holes with different radius of 0.28-0.30 nm and 0.44-0.45 nm. The smaller holes should be located in both PTFE crystallites and poly(styrene sulfonic acid) grafts, while the larger holes are considered to exist in amorphous PTFE phases.

  14. BFR Electrolyte Additive Safety and Flammability Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Allcorn, Eric [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-10-13

    Lithium-ion battery safety is a critical issue in the adoption of the chemistry to larger scale applications such as transportation and stationary storage. One of the critical components impacting the safety of lithium-ion batteries is their use of highly flammable organic electrolytes. In this work, brominated flame retardants (BFR’s) – an existing class of flame retardant materials – are incorporated as additives to lithium-ion battery electrolytes with the intention to reduce the electrolyte flammability and thereby improve safety. There are a few critical needs for a successful electrolyte additive: solubility in the electrolyte, electrochemical stability over the range of battery operation, and minimal detrimental effects on battery performance. Those detrimental effects can take the form of electrolyte specific impacts, such as a reduction in conductivity, or electrode impacts, such as SEI-layer modification or chemical instability to the active material. In addition to these needs, the electrolyte additive also needs to achieve its intended purpose, which in this case is to reduce the flammability of the electrolyte. For the work conducted as part of this SPP agreement three separate BFR materials were provided by Albemarle to be tested by Sandia as additives in a traditional lithium-ion battery electrolyte. The provided BFR materials were tribromo-neopentyl alcohol, tetrabromo bisphenol A, and tribromoethylene. These materials were incorporated as separate 4 wt.% additives into a traditional lithium-ion battery electrolyte and compared to said traditional electrolyte, designated Gen2.

  15. Development and evaluation of a multimedia e-learning resource for electrolyte and acid-base disorders.

    Science.gov (United States)

    Davids, Mogamat Razeen; Chikte, Usuf M E; Halperin, Mitchell L

    2011-09-01

    This article reports on the development and evaluation of a Web-based application that provides instruction and hands-on practice in managing electrolyte and acid-base disorders. Our teaching approach, which focuses on concepts rather than details, encourages quantitative analysis and a logical problem-solving approach. Identifying any dangers to the patient is a vital first step. Concepts such as an "appropriate response" to a given perturbation and the need for electroneutrality in body fluids are used repeatedly. Our Electrolyte Workshop was developed using Flash and followed an iterative design process. Two case-based tutorials were built in this first phase, with one tutorial including an interactive treatment simulation. Users select from a menu of therapies and see the impact of their choices on the patient. Appropriate text messages are displayed, and changes in body compartment sizes, brain size, and plasma sodium concentrations are illustrated via Flash animation. Challenges encountered included a shortage of skilled Flash developers, budgetary constraints, and challenges in communication between the authors and the developers. The application was evaluated via user testing by residents and specialists in internal medicine. Satisfaction was measured with a questionnaire based on the System Usability Scale. The mean System Usability Scale score was 78.4 ± 13.8, indicating a good level of usability. Participants rated the content as being scientifically sound; they liked the teaching approach and felt that concepts were conveyed clearly. They indicated that the application held their interest, that it increased their understanding of hyponatremia, and that they would recommend this learning resource to others.

  16. Review of progresses on clinical applications of ion selective electrodes for electrolytic ion tests: from conventional ISEs to graphene-based ISEs

    Directory of Open Access Journals (Sweden)

    Rongguo Yan

    2016-10-01

    Full Text Available There exist several positively and negatively charged electrolytes or ions in human blood, urine, and other body fluids. Tests that measure the concentration of these ions in clinics are performed using a more affordable, portable, and disposable potentiometric sensing method with few sample volumes, which requires the use of ion-selective electrodes (ISEs and reference electrodes. This review summarily descriptively presents progressive developments and applications of ion selective electrodes in medical laboratory electrolytic ion tests, from conventional ISEs, solid-contact ISEs, carbon nanotube based ISEs, to graphene-based ISEs.

  17. Dictionary Learning Based Dimensionality Reduction for Classification

    OpenAIRE

    Schnass, Karin; Vandergheynst, Pierre

    2008-01-01

    In this article we present a signal model for classification based on a low dimensional dictionary embedded into the high dimensional signal space. We develop an alternate projection algorithm to find the embedding and the dictionary and finally test the classification performance of our scheme in comparison to Fisher’s LDA.

  18. Consumer-based carbon reduction incentives

    OpenAIRE

    Simon Niemeyer

    1998-01-01

    Australia's ability to meet its commitment to reduce greenhouse gases under the Kyoto convention will probably require at least some government intervention. Traditionally, approaches to reducing pollution in Australia have tended to focus on the adoption of emission standards. Theoretical criticism by environmental economists has, in part, resulted in a movement toward the adoption of market based mechanisms for pollution abatement; and flirtations with carbon taxes and tradeable permits to ...

  19. Applying Groebner bases to solve reduction problems for Feynman integrals

    International Nuclear Information System (INIS)

    Smirnov, Alexander V.; Smirnov, Vladimir A.

    2006-01-01

    We describe how Groebner bases can be used to solve the reduction problem for Feynman integrals, i.e. to construct an algorithm that provides the possibility to express a Feynman integral of a given family as a linear combination of some master integrals. Our approach is based on a generalized Buchberger algorithm for constructing Groebner-type bases associated with polynomials of shift operators. We illustrate it through various examples of reduction problems for families of one- and two-loop Feynman integrals. We also solve the reduction problem for a family of integrals contributing to the three-loop static quark potential

  20. Electrodeposition of compact zinc from the hydrophobic Brønsted acidic ionic liquid-based electrolytes and the study of zinc stability along with the acidity manipulation

    International Nuclear Information System (INIS)

    Chen, Yi-Han; Yeh, Hsin-Wen; Lo, Nai-Chang; Chiu, Chen-Wei; Sun, I-Wen; Chen, Po-Yu

    2017-01-01

    Highlights: • Compact Zn with no crack is deposited from protic ionic liquid-based electrolytes. • The ionic liquid is composed of the protonated betaine ion. • This ionic liquid is hydrophobic and zinc oxide is soluble in it. • The effects of co-solvents, propylene carbonate and water, are studied. • The Zn stripping/deposition efficiency can be manipulated via acidity adjustment. - Abstract: Compact crystalline zinc was electrodeposited on stainless-steel electrode (SS) via potentiostatic/galvanostatic electrolysis from the hydrophobic Brønsted acidic ionic liquid, protonated betaine bis((trifluoromethyl)sulfonyl)imide (IL [Hbet][TFSI]), −based electrolytes containing ZnCl 2 or ZnO under argon or ambient air atmosphere. Approximate 10 wt% of propylene carbonate and water, respectively, were used as the co-solvents for [Hbet][TFSI] to form the IL-based electrolytes. The efficiency of zinc deposition/stripping, which is significantly affected by the Brønsted acidity of the IL-based electrolytes, was studied at glassy carbon electrode (GC) to evaluate the stability of the zinc electrodeposits along with the electrolyte acidity. The stability is very poor for the zinc electrodeposits obtained from ZnCl 2 solution. However, it increases with increasing the quantity of ZnO or urea in the electrolytes; the former neutralize the dissociable protons in [Hbet] cations to form water, and the latter may form H-bonding with [Hbet] or be protonated to form the weakly acidic cations [HUrea]. Both suppress the reaction between the Zn electrodeposits and protons. The stability of the Zn electrodeposits, therefore, can be improved via the manipulation of the IL acidity.

  1. Long-Term Synaptic Plasticity Emulated in Modified Graphene Oxide Electrolyte Gated IZO-Based Thin-Film Transistors.

    Science.gov (United States)

    Yang, Yi; Wen, Juan; Guo, Liqiang; Wan, Xiang; Du, Peifu; Feng, Ping; Shi, Yi; Wan, Qing

    2016-11-09

    Emulating neural behaviors at the synaptic level is of great significance for building neuromorphic computational systems and realizing artificial intelligence. Here, oxide-based electric double-layer (EDL) thin-film transistors were fabricated using 3-triethoxysilylpropylamine modified graphene oxide (KH550-GO) electrolyte as the gate dielectrics. Resulting from the EDL effect and electrochemical doping between mobile protons and the indium-zinc-oxide channel layer, long-term synaptic plasticity was emulated in our devices. Synaptic functions including long-term memory, synaptic temporal integration, and dynamic filters were successfully reproduced. In particular, spike rate-dependent plasticity (SRDP), one of the basic learning rules of long-term plasticity in the neural network where the synaptic weight changes according to the rate of presynaptic spikes, was emulated in our devices. Our results may facilitate the development of neuromorphic computational systems.

  2. Flexible, Low-Cost Sensor Based on Electrolyte Gated Carbon Nanotube Field Effect Transistor for Organo-Phosphate Detection.

    Science.gov (United States)

    Bhatt, Vijay Deep; Joshi, Saumya; Becherer, Markus; Lugli, Paolo

    2017-05-18

    A flexible enzymatic acetylcholinesterase biosensor based on an electrolyte-gated carbon nanotube field effect transistor is demonstrated. The enzyme immobilization is done on a planar gold gate electrode using 3-mercapto propionic acid as the linker molecule. The sensor showed good sensing capability as a sensor for the neurotransmitter acetylcholine, with a sensitivity of 5.7 μA/decade, and demonstrated excellent specificity when tested against interfering analytes present in the body. As the flexible sensor is supposed to suffer mechanical deformations, the endurance of the sensor was measured by putting it under extensive mechanical stress. The enzymatic activity was inhibited by more than 70% when the phosphate-buffered saline (PBS) buffer was spiked with 5 mg/mL malathion (an organophosphate) solution. The biosensor was successfully challenged with tap water and strawberry juice, demonstrating its usefulness as an analytical tool for organophosphate detection.

  3. The effect of isocyanate structure on ionic conductivity of waste cooking oil based polyurethane solid polymer electrolyte

    Science.gov (United States)

    Kamarulzaman, N. A.; Tahir, S. M.

    2017-09-01

    Polyurethane solid polymer electrolyte (SPE) films was prepared via solvent-free method using waste cooking oil-based polyol, diisocyanate, LiTFSI salt and ethylene carbonate as plasticizer. Two types of diisocyanate were chosen; aromatic 4,4-diphenylmethane diisocyanate (MDI) and aliphatic 1,6-hexamethylene diisocyanate (HDI) and the effect of diisocyanate structure on SPE properties were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Electrochemical Impedance Spectroscopy (EIS), Differential Scanning Calorimetry (DSC) and X-Ray Diffractometry (XRD). The highest ionic conductivity achieved was 5.76 × 10-6 S cm-1 using MDI. This was supported with lower crystallinity observed by decrease in peaks intensity in XRD. The findings indicated that aromatic diisocyanate is more suitable to produce polyurethane SPE.

  4. Characterization and electrical properties of polyvinyl alcohol based polymer electrolyte films doped with ammonium thiocyanate

    Energy Technology Data Exchange (ETDEWEB)

    Kulshrestha, N., E-mail: niharikakul@gmail.com; Chatterjee, B.; Gupta, P.N., E-mail: guptapn07@yahoo.co.in

    2014-05-01

    Highlights: • Polyvinyl alcohol (PVA). • Ammonium thiocyanate (NH{sub 4}SCN). • Electrical conductivity. • Fractals. - Abstract: In this communication, films of polyvinyl alcohol (PVA) polymer complexed with ammonium thiocyanate (NH{sub 4}SCN) salt were studied. XRD (X-ray diffraction) was used to study the complexation of salt with the polymer matrix and amorphicity in the films. DSC (differential scanning calorimetry) studies showed that the glass transition temperatures (T{sub g}) of the PVA:NH{sub 4}SCN complexed films were less than pristine PVA. Raman analysis was analyzed in order to study the change in the vibrational bands due to the complexation of salt with PVA. Optical micrographs confirm the fractal formation in 75:25 and 70:30 PVA:NH{sub 4}SCN films. Ionic transference number was estimated by Wagner's polarization method and its large value indicates that conduction takes place mainly due to mobile ionic species. Maximum conductivity ∼10{sup −3} S/cm at room temperature was obtained for 70:30 ratio of PVA: NH{sub 4}SCN polymer electrolyte films.

  5. Sol-Gel Synthesis of Ceria-Based Electrolytes and Perovskite-Type Cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Pinol, S.; Calleja, A.; Capdevila, X. G.; Najib, M.; Espiell, F.

    2002-06-01

    We have successfully prepared electrolytes of Ce{sub 0.8}Sm{sub 0.2}O{sub 1.9} (SDC) and Ce{sub 0.8}Sm{sub 0.2}O{sub 1.9} (GDC) and cathodes of La{sub 1-x}Sr{sub x}CoO{sub 3} (LSCO) and La{sub 1-x}Sr{sub x}MnO{sub 3} (LSMO), useful for SOFCs, by the acrylamide sol-gel method. This method consists in the preparation of a solution from the elemental oxides and carbonates followed by a gellification with acrylamide monomer. Then, the combustion of the organic molecules is initiated, obtaining ultra fine calcined powders of the above-mentioned compounds. In this way, we have obtained high purity powders of SDC, GDC, LSCO and LSMO as confirmed by X-ray diffraction powder analysis. On the other hand, we have also studied the preparation of the same products by the solid-state reaction technique for comparison purposes. However, it was not possible to obtain pure LSCO by this ceramic method. We have observed that the optimal synthesis temperature is lower for the sol-gel samples and the final purity of the products is higher. (author)

  6. Characterization and electrical properties of polyvinyl alcohol based polymer electrolyte films doped with ammonium thiocyanate

    International Nuclear Information System (INIS)

    Kulshrestha, N.; Chatterjee, B.; Gupta, P.N.

    2014-01-01

    Highlights: • Polyvinyl alcohol (PVA). • Ammonium thiocyanate (NH 4 SCN). • Electrical conductivity. • Fractals. - Abstract: In this communication, films of polyvinyl alcohol (PVA) polymer complexed with ammonium thiocyanate (NH 4 SCN) salt were studied. XRD (X-ray diffraction) was used to study the complexation of salt with the polymer matrix and amorphicity in the films. DSC (differential scanning calorimetry) studies showed that the glass transition temperatures (T g ) of the PVA:NH 4 SCN complexed films were less than pristine PVA. Raman analysis was analyzed in order to study the change in the vibrational bands due to the complexation of salt with PVA. Optical micrographs confirm the fractal formation in 75:25 and 70:30 PVA:NH 4 SCN films. Ionic transference number was estimated by Wagner's polarization method and its large value indicates that conduction takes place mainly due to mobile ionic species. Maximum conductivity ∼10 −3 S/cm at room temperature was obtained for 70:30 ratio of PVA: NH 4 SCN polymer electrolyte films

  7. Characteristics of Honeycomb-Type Oxygen Generator with Electrolyte Based on Doped Bismuth Oxide

    Science.gov (United States)

    Chen, Yu-Wen; Liu, Yi-Xin; Wang, Sea-Fue; Devasenathipathy, Rajkumar

    2018-03-01

    An oxygen generator using Y-doped Bi2O3 as electrolyte to transport oxygen ions has been developed, having honeycomb-type structure with dimensions of 40 mm × 35 mm × 30 mm and consisting of 13 × 12 channels. External wire circuitry for the channels arrayed using parallel, series, and hybrid connection was evaluated to achieve the best oxygen separation efficiency. It was observed that the oxygen generator with hybrid connection facilitated evolution of oxygen at maximum of 117 sccm and high purity > 99.9% at 550°C under current flow of 14 A. Addition of 5 wt.% silane and 3 wt.% glass-ceramic powder to the Ag slurry used at both electrodes not only increased the coverage of the metal electrode on the ceramic substrate during dip coating but also prevented cracking at the electrode layer of the module under stress from the electric field and temperature during high-temperature operation, thus reducing the decay rate of the oxygen generator in durability testing.

  8. A redox-flow battery with an alloxazine-based organic electrolyte

    Science.gov (United States)

    Lin, Kaixiang; Gómez-Bombarelli, Rafael; Beh, Eugene S.; Tong, Liuchuan; Chen, Qing; Valle, Alvaro; Aspuru-Guzik, Alán; Aziz, Michael J.; Gordon, Roy G.

    2016-09-01

    Redox-flow batteries (RFBs) can store large amounts of electrical energy from variable sources, such as solar and wind. Recently, redox-active organic molecules in aqueous RFBs have drawn substantial attention due to their rapid kinetics and low membrane crossover rates. Drawing inspiration from nature, here we report a high-performance aqueous RFB utilizing an organic redox compound, alloxazine, which is a tautomer of the isoalloxazine backbone of vitamin B2. It can be synthesized in high yield at room temperature by single-step coupling of inexpensive o-phenylenediamine derivatives and alloxan. The highly alkaline-soluble alloxazine 7/8-carboxylic acid produces a RFB exhibiting open-circuit voltage approaching 1.2 V and current efficiency and capacity retention exceeding 99.7% and 99.98% per cycle, respectively. Theoretical studies indicate that structural modification of alloxazine with electron-donating groups should allow further increases in battery voltage. As an aza-aromatic molecule that undergoes reversible redox cycling in aqueous electrolyte, alloxazine represents a class of radical-free redox-active organics for use in large-scale energy storage.

  9. Lithium battery with solid polymer electrolyte based on comb-like copolymers

    Science.gov (United States)

    Daigle, Jean-Christophe; Vijh, Ashok; Hovington, Pierre; Gagnon, Catherine; Hamel-Pâquet, Julie; Verreault, Serge; Turcotte, Nancy; Clément, Daniel; Guerfi, Abdelbast; Zaghib, Karim

    2015-04-01

    In this paper we report on the synthesis of comb-like copolymers as solid polymer electrolytes (SPE). The synthesis involved anionic polymerization of styrene (St) and 4-vinylanisole (VA) as the followed by grafting of poly(ethylene glycol) monomethyl ether methacrylate (PEGMA) by Atom Transfer Radical Polymerization (ATRP). The comb-like copolymer's structure was analyzed by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The membranes were made by solvent casting and the morphologies were analyzed by atomic forces microscopy (AFM) and scanning electron microscopy (SEM). We observed that a nano and micro phase separation occurs which improves ionic conductivity. The ionic conductivities were determined by AC Impedance, which showed that the SPEs have good conductivities (10-5 Scm-1) at room temperature owing to the negligible values (<10 kJ mol-1) of the activation energies for conductivity. The batteries with these polymers exhibit a capacity of 146 mAh g-1 at C/24, and no evidence of degradation after intense cycling was observed. However, poor cycle life was observed at C/6 and C/3, which is a consequence of several factors. We partially explain that behavior by arguing that whereas PEO lightly "solvates" Li+ thus slowing Li-ion mobility, and PEGMA chains "solvate" Li ions too strongly, trapping and inhibiting their mobility.

  10. Evaluation of Contrail Reduction Strategies Based on Aircraft Flight Distances

    Science.gov (United States)

    Chen, Neil Y.; Sridhar, Banavar; Li, Jinhua; Ng, Hok Kwan

    2012-01-01

    This paper evaluates a set of contrail reduction strategies based on the flight range of aircraft as contrail reduction strategies have different impacts on aircraft depending on how they plan to fly. In general, aircraft with longer flight distances cruise at the altitudes where contrails are more likely to form. The concept of the contrail frequency index is used to quantify contrail impacts. The strategy for reducing the persistent contrail formation is to minimize the contrail frequency index by altering the aircraft's cruising altitude. A user-defined factor is used to trade off between contrail reduction and extra CO2 emissions. A higher value of tradeoff factor results in more contrail reduction and extra CO2 emissions. Results show that contrail reduction strategies using various tradeo factors behave differently from short-range flights to long-range ights. Analysis shows that short-distance flights (less than 500 miles) are the most frequent flights but contribute least to contrail reduction. Therefore these aircraft have the lowest priority when applying contrail reduction strategies. Medium-distance flights (500 to 1000 miles) have a higher priority if the goal is to achieve maximum contrail reduction in total; long-distance flights (1000 to 1500 miles) have a higher priority if the goal is to achieve maximum contrail reduction per flight. The characteristics of transcontinental flights (greater than 1500 miles) vary with different weather days so the priority of applying contrail reduction strategies to the group needs to be evaluated based on the locations of the contrail areas during any given day. For the days tested, medium-distance ights contribute up to 42.6% of the reduction among the groups during a day. The contrail frequency index per 1,000 miles for medium-distance, long-distance, and transcontinental flights can be reduced by an average of 75%. The results provide a starting point for developing operational policies to reduce the impact of

  11. Application of Electrochemical Impedance Spectroscopy for Fuel Cell Characterization: Polymer Electrolyte Fuel Cell (PEFC) and Oxygen Reduction Reaction in Alkaline Solution

    OpenAIRE

    Wagner, Norbert

    2012-01-01

    Separation of different electrochemical and ohmic contributions to the current/voltage U(i) characteristics requires additional experimental techniques like Electrochemical Impedance Spectroscopy (EIS). The application of EIS is an approach to determine parameters which have proved to be indispensable for the characterization and development of fuel cell electrodes and electrolyte electrode assemblies. By varying the operating conditions of the fuel cell and by simulation of the measured ...

  12. Adding trend data to Depletion-Based Stock Reduction Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Bayesian model of Depletion-Based Stock Reduction Analysis (DB-SRA), informed by a time series of abundance indexes, was developed, using the Sampling Importance...

  13. Co9S8/Co as a High-Performance Anode for Sodium-Ion Batteries with an Ether-Based Electrolyte.

    Science.gov (United States)

    Zhao, Yingying; Pang, Qiang; Wei, Yingjin; Wei, Luyao; Ju, Yanming; Zou, Bo; Gao, Yu; Chen, Gang

    2017-12-08

    Co 9 S 8 has been regarded as a desirable anode material for sodium-ion batteries because of its high theoretical capacity. In this study, a Co 9 S 8 anode material containing 5.5 wt % Co (Co 9 S 8 /Co) was prepared by a solid-state reaction. The electrochemical properties of the material were studied in carbonate and ether-based electrolytes (EBE). The results showed that the material had a longer cycle life and better rate capability in EBE. This excellent electrochemical performance was attributed to a low apparent activation energy and a low overpotential for Na deposition in EBE, which improved the electrode kinetic properties. Furthermore, EBE suppressed side reactions of the electrode and electrolyte, which avoided the formation of a solid electrolyte interphase film. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Polyaniline-grafted silica nanocomposites-based gel electrolytes for quasi-solid-state dye-sensitized solar cells

    Science.gov (United States)

    Ma, Pin; Tan, Jing; Cheng, Hongbo; Fang, Yanyan; Wang, Yanan; Dai, Yuhua; Fang, Shibi; Zhou, Xiaowen; Lin, Yuan

    2018-01-01

    Polyaniline-grafted silica nanocomposites (PANI-SiO2), which are synthesized through in-situ surface chemical oxidative polymerization of aniline with the NH2-modified silica nanoparticles, are exploited as gelators in the ionic-liquid electrolytes for dye-sensitized solar cells (DSCs). It can be clearly seen that the PANI-SiO2 nanocomposites have the well-interconnected network structure, which not only serve as gelators to effectively solidfy the ionic-liquid electrolytes, but also significantly improve the ion conductivity of electrolytes and the diffusion coefficient of I3- ions. As a result, an optimal efficiency of 7.15% for DSC using gel electrolyte is achieved due to the enhancement of photocurrent density (Jsc) and fill factor (FF), which is increased by 18.99% than that of the cell using ionic-liquid electrolyte.

  15. Solid oxide fuel cells with apatite-type lanthanum silicate-based electrolyte films deposited by radio frequency magnetron sputtering

    Science.gov (United States)

    Liu, Yi-Xin; Wang, Sea-Fue; Hsu, Yung-Fu; Wang, Chi-Hua

    2018-03-01

    In this study, solid oxide fuel cells (SOFCs) containing high-quality apatite-type magnesium doped lanthanum silicate-based electrolyte films (LSMO) deposited by RF magnetron sputtering are successfully fabricated. The LSMO film deposited at an Ar:O2 ratio of 6:4 on an anode supported NiO/Sm0.2Ce0·8O2-δ (SDC) substrate followed by post-annealing at 1000 °C reveals a uniform and dense c-axis oriented polycrystalline structure, which is well adhered to the anode substrate. A composite SDC/La0·6Sr0·4Co0·2Fe0·8O3-δ cathode layer is subsequently screen-printed on the LSMO deposited anode substrate and fired. The SOFC fabricated with the LSMO film exhibits good mechanical integrity. The single cell with the LSMO layer of ≈2.8 μm thickness reports a total cell resistance of 1.156 and 0.163 Ωcm2, open circuit voltage of 1.051 and 0.982 V, and maximum power densities of 0.212 and 1.490 Wcm-2 at measurement temperatures of 700 and 850 °C, respectively, which are comparable or superior to those of previously reported SOFCs with yttria stabilized zirconia electrolyte films. The results of the present study demonstrate the feasibility of deposition of high-quality LSMO films by RF magnetron sputtering on NiO-SDC anode substrates for the fabrication of SOFCs with good cell performance.

  16. Fukunaga-Koontz transform based dimensionality reduction for hyperspectral imagery

    Science.gov (United States)

    Ochilov, S.; Alam, M. S.; Bal, A.

    2006-05-01

    Fukunaga-Koontz Transform based technique offers some attractive properties for desired class oriented dimensionality reduction in hyperspectral imagery. In FKT, feature selection is performed by transforming into a new space where feature classes have complimentary eigenvectors. Dimensionality reduction technique based on these complimentary eigenvector analysis can be described under two classes, desired class and background clutter, such that each basis function best represent one class while carrying the least amount of information from the second class. By selecting a few eigenvectors which are most relevant to desired class, one can reduce the dimension of hyperspectral cube. Since the FKT based technique reduces data size, it provides significant advantages for near real time detection applications in hyperspectral imagery. Furthermore, the eigenvector selection approach significantly reduces computation burden via the dimensionality reduction processes. The performance of the proposed dimensionality reduction algorithm has been tested using real-world hyperspectral dataset.

  17. Fuel cell electrolytes: Evolution, properties and future prospects

    Science.gov (United States)

    Appleby, A. J.

    1994-04-01

    Any electrolyte with sufficient ionic conductivity may be used in a fuel cell, but to avoid concentration gradients in the electrolyte, active conduction should be via an ion produced in one electrode reaction and consumed in the other. This ion must be present at high concentration in the electrolyte. In aqueous fuel cells operating on hydrogen and oxygen, the only useful electrolytes have high concentrations of either H(+) or OH(-), i.e., strong acids or bases. The product of the anode reaction in aqueous acids, H(+), occurs as a 'carrier ion' complexed by H2O as H(H2O)(sub n)(+), where n lies between 1 and 4. The corresponding cathodic product ion in bases, OH(-), is itself a 'carrier ion', the reaction product of O(2-) from the reduction of O2 and H2O. Phosphoric acid is not an aqueous acid, but a unique self-ionizing amphoteric system, in effect a molten acidic H(+) salt. In molten salts, H(+) could be the primary conductor, e.g., in molten bisulfates. Less corrosive carbonate melts use a cathodic supply of CO2 supplied via the gas phase to give CO2(2-) as the O(2-) 'carrier ion'. A similar approach may be used in aqueous carbonates. No carrier material is needed in solid oxides, which conduct directly via O(2-) ion. The temperature windows for different electrolytes are limited by performance at the low end and materials considerations at the high end. As a result, there are no electrolytes capable of operation between 480 and 900 K, and between 1050 and 1220 K. Development of electrolytes for these temperature ranges would be valuable.

  18. Oxygen reduction and methanol oxidation behaviour of SiC based Pt nanocatalysts for proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

    Dhiman, Rajnish; Stamatin, Serban Nicolae; Andersen, Shuang Ma

    2013-01-01

    with the present carbon based substrates. We have recently examined suitably sized silicon carbide (SiC) particles as catalyst supports for fuel cells based on the stable chemical and mechanical properties of this material. In the present study, we have continued our work with studies of the oxygen reduction...... and methanol oxidation reactions of SiC supported catalysts and measured them against commercially available carbon based catalysts. The deconvolution of the hydrogen desorption signals in CV cycles shows a higher contribution of Pt (110) & Pt (111) peaks compared to Pt (100) for SiC based supports than...... for carbon based commercial catalyst, when HClO4 is used as electrolyte. The Pt (110) & Pt (111) facets are shown to have higher electrochemical activities than Pt (100) facets. To the best of our knowledge, methanol oxidation studies and the comparison of peak deconvolutions of the H desorption region in CV...

  19. Compositional effect investigation by addition PEG, PEO plasticiser of LiBOB based solid polymer electrolyte for lithium ion batteries

    Science.gov (United States)

    Sabrina, Qolby; Ratri, Christin Rina

    2017-08-01

    Development polymer electrolyte with high ionic conductivity is main of object in solid state electrolyte will be potential application as electrolyte batteries. Casting method have been used to prepared solid polymer electrolyte. Adding polyethylene(glycol) PEG and Poly(ethylene oxide) PEO as polymer matrix be made of poly(vinylidene fluoride) (PVdF) and lithium bis(oxalato) borate (LiBOB) to improve structure morphology and impedance characterization of solid electrolyte. The ratio of PEG and PEO is varied to study effect on the conductivity. Electro impedance spectroscopy (EIS) studies are carried out on the prepared samples. The impedance measurement show that the conductivity with composition PVdF- PEG- LiBOB 10% better than the other varieties to applied as solid electrolyte batteries. SEM morphology PVdF- PEG- LiBOB 10% sample showed the low crystallinity was caused by interaction between lithium salt and polymer. With their properties the solid polymer electrolyte are considered as promising candidates of applications for lithium ion batteries.

  20. Organic Electrolyte Based Pulsed Nanoplating and Fabrication of Carbon Nanotube Network Transistors

    Science.gov (United States)

    Kang, Myung Gil; Hwang, Dong Hoon; Kim, Tae Geun; Hwang, Jong Seung; Ahn, Doyeol; Whang, Dongmok; Hwang, Sung Woo

    2011-06-01

    The formation of gold nanocontacts was performed using a pulsed electrochemical plating technique. The effect of various plating variables on the surface roughness of the plated electrodes was studied in the high frequency regime where the reduction reaction of gold complex becomes the bottleneck process. We demonstrated the selective contact formation of single wall carbon nanotube network field effect transistors (FETs) with this technique. The fabricated FETs exhibit usual p-type behavior with the performance comparable to usual network FETs.

  1. Improved power conversion efficiency of dye-sensitized solar cells using side chain liquid crystal polymer embedded in polymer electrolytes

    International Nuclear Information System (INIS)

    Cho, Woosum; Lee, Jae Wook; Gal, Yeong-Soon; Kim, Mi-Ra; Jin, Sung Ho

    2014-01-01

    Side chain liquid crystal polymer (SCLCP) embedded in poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-co-HFP)-based polymer electrolytes (PVdF-co-HFP:side chain liquid crystal polymer (SCLCP)) was prepared for dye-sensitized solar cell (DSSC) application. The polymer electrolytes contained tetrabutylammonium iodide (TBAI), iodine (I 2 ), and 8 wt% PVdF-co-HFP in acetonitrile. DSSCs comprised of PVdF-co-HFP:SCLCP-based polymer electrolytes displayed enhanced redox couple reduction and reduced charge recombination in comparison to those of the conventional PVdF-co-HFP-based polymer electrolyte. The significantly increased short-circuit current density (J sc , 10.75 mA cm −2 ) of the DSSCs with PVdF-co-HFP:SCLCP-based polymer electrolytes afforded a high power conversion efficiency (PCE) of 5.32% and a fill factor (FF) of 0.64 under standard light intensity of 100 mW cm −2 irradiation of AM 1.5 sunlight. - Highlights: • We developed the liquid crystal polymer embedded on polymer electrolyte for DSSCs. • We fabricated the highly efficient DSSCs using polymer electrolyte. • The best PCE achieved for P1 is 5.32% using polymer electrolyte

  2. Reduction of inequalities in health: assessing evidence-based tools

    OpenAIRE

    Shea Beverley; Hatcher-Roberts Jan; Robinson Vivian; Jacobsen Mary; Kristjansson Elizabeth; Mhatre Sharmila; Andersson Neil; O'Connor Annette; Tugwell Peter; Francis Daniel; Beardmore Jil; Wells George A; Losos Joe

    2006-01-01

    Abstract Background The reduction of health inequalities is a focus of many national and international health organisations. The need for pragmatic evidence-based approaches has led to the development of a number of evidence-based equity initiatives. This paper describes a new program that focuses upon evidence- based tools, which are useful for policy initiatives that reduce inequities. Methods This paper is based on a presentation that was given at the "Regional Consultation on Policy Tools...

  3. Comparison of chitosan and chitosan nanoparticles on the performance and charge recombination of water-based gel electrolyte in dye sensitized solar cells.

    Science.gov (United States)

    Khalili, Malihe; Abedi, Mohammad; Amoli, Hossein Salar; Mozaffari, Seyed Ahmad

    2017-11-01

    In commercialization of liquid dye-sensitized solar cells (DSSCs), whose leakage, evaporation and toxicity of organic solvents are limiting factors, replacement of organic solvents with water-based gel electrolyte is recommended. This work reports on utilizing and comparison of chitosan and chitosan nanoparticle as different gelling agents in preparation of water-based gel electrolyte in fabrication of dye sensitized solar cells. All photovoltaic parameters such as open circuit voltage (V oc ), fill factor (FF), short circuit current density (J sc ) and conversion efficiency (η) were measured. For further characterization, electrochemical impedance spectroscopy (EIS) was used to study the charge transfer at Pt/electrolyte interface and charge recombination and electron transport at TiO 2 /dye/electrolyte interface. Significant improvements in conversion efficiency and short circuit current density of DSSCs fabricated by chitosan nanoparticle were observed that can be attributed to the higher mobility of I 3 - due to the lower viscosity and smaller size of chitosan nanoparticles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Lessons learned from community-based approaches to sodium reduction.

    Science.gov (United States)

    Kane, Heather; Strazza, Karen; Losby, Jan L; Lane, Rashon; Mugavero, Kristy; Anater, Andrea S; Frost, Corey; Margolis, Marjorie; Hersey, James

    2015-01-01

    This article describes lessons from a Centers for Disease Control and Prevention initiative encompassing sodium reduction interventions in six communities. A multiple case study design was used. This evaluation examined data from programs implemented in six communities located in New York (Broome County, Schenectady County, and New York City); California (Los Angeles County and Shasta County); and Kansas (Shawnee County). Participants (n = 80) included program staff, program directors, state-level staff, and partners. Measures for this evaluation included challenges, facilitators, and lessons learned from implementing sodium reduction strategies. The project team conducted a document review of program materials and semistructured interviews 12 to 14 months after implementation. The team coded and analyzed data deductively and inductively. Five lessons for implementing community-based sodium reduction approaches emerged: (1) build relationships with partners to understand their concerns, (2) involve individuals knowledgeable about specific venues early, (3) incorporate sodium reduction efforts and messaging into broader nutrition efforts, (4) design the program to reduce sodium gradually to take into account consumer preferences and taste transitions, and (5) identify ways to address the cost of lower-sodium products. The experiences of the six communities may assist practitioners in planning community-based sodium reduction interventions. Addressing sodium reduction using a community-based approach can foster meaningful change in dietary sodium consumption.

  5. Apparatus for the electrolytic production of metals

    Science.gov (United States)

    Sadoway, Donald R.

    1993-01-01

    Improved electrolytic cells for producing metals by the electrolytic reduction of a compound dissolved in a molten electrolyte are disclosed. In the improved cells, at least one electrode includes a protective layer comprising an oxide of the cell product metal formed upon an alloy of the cell product metal and a more noble metal. In the case of an aluminum reduction cell, the electrode can comprise an alloy of aluminum with copper, nickel, iron, or combinations thereof, upon which is formed an aluminum oxide protective layer.

  6. Preparation and characterization of electrospun poly(acrylonitrile) fibrous membrane based gel polymer electrolytes for lithium-ion batteries

    Science.gov (United States)

    Carol, Priya; Ramakrishnan, Prakash; John, Bibin; Cheruvally, Gouri

    Electrospun, non-woven membrane of high molecular weight poly(acrylonitrile) (PAN) is demonstrated as an efficient host matrix for the preparation of gel polymer electrolytes for lithium-ion batteries. Electrospinning process parameters are optimized to get a fibrous membrane of PAN consisting of bead-free, uniformly dispersed thin fibers with diameter in the range 880-1260 nm. The membrane with good mechanical strength and porosity exhibits high uptake when activated with the liquid electrolyte of 1 M LiPF 6 in a mixture of organic solvents and the gel polymer electrolyte shows ionic conductivity of 1.7 × 10 -5 S cm -1 at 20 °C. Electrochemical performance of the gel polymer electrolyte at 20 °C is evaluated in lithium-ion cell with lithium cobalt oxide cathode and graphite anode. Good performance with a low capacity fading on charge-discharge cycling is demonstrated.

  7. Synthesis of Ionic Liquid Based Electrolytes, Assembly of Li-ion Batteries, and Measurements of Performance at High Temperature.

    Science.gov (United States)

    Lin, Xinrong; Chapman Varela, Jennifer; Grinstaff, Mark W

    2016-12-20

    The chemical instability of the traditional electrolyte remains a safety issue in widely used energy storage devices such as Li-ion batteries. Li-ion batteries for use in devices operating at elevated temperatures require thermally stable and non-flammable electrolytes. Ionic liquids (ILs), which are non-flammable, non-volatile, thermally stable molten salts, are an ideal replacement for flammable and low boiling point organic solvent electrolytes currently used today. We herein describe the procedures to: 1) synthesize mono- and di-phosphonium ionic liquids paired with chloride or bis(trifluoromethane)sulfonimide (TFSI) anions; 2) measure the thermal properties and stability of these ionic liquids by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA); 3) measure the electrochemical properties of the ionic liquids by cyclic voltammetry (CV); 4) prepare electrolytes containing lithium bis(trifluoromethane)sulfonamide; 5) measure the conductivity of the electrolytes as a function of temperature; 6) assemble a coin cell battery with two of the electrolytes along with a Li metal anode and LiCoO2 cathode; and 7) evaluate battery performance at 100 °C. We additionally describe the challenges in execution as well as the insights gained from performing these experiments.

  8. Identification of Diethyl 2,5-Dioxahexane Dicarboxylate and Polyethylene Carbonate as Decomposition Products of Ethylene Carbonate Based Electrolytes by Fourier Transform Infrared Spectroscopy

    KAUST Repository

    Shi, Feifei

    2014-07-10

    The formation of passive films on electrodes due to electrolyte decomposition significantly affects the reversibility of Li-ion batteries (LIBs); however, understanding of the electrolyte decomposition process is still lacking. The decomposition products of ethylene carbonate (EC)-based electrolytes on Sn and Ni electrodes are investigated in this study by Fourier transform infrared (FTIR) spectroscopy. The reference compounds, diethyl 2,5-dioxahexane dicarboxylate (DEDOHC) and polyethylene carbonate (poly-EC), were synthesized, and their chemical structures were characterized by FTIR spectroscopy and nuclear magnetic resonance (NMR). Assignment of the vibration frequencies of these compounds was assisted by quantum chemical (Hartree-Fock) calculations. The effect of Li-ion solvation on the FTIR spectra was studied by introducing the synthesized reference compounds into the electrolyte. EC decomposition products formed on Sn and Ni electrodes were identified as DEDOHC and poly-EC by matching the features of surface species formed on the electrodes with reference spectra. The results of this study demonstrate the importance of accounting for the solvation effect in FTIR analysis of the decomposition products forming on LIB electrodes. © 2014 American Chemical Society.

  9. Effect of the Hydrofluoroether Cosolvent Structure in Acetonitrile-Based Solvate Electrolytes on the Li+ Solvation Structure and Li-S Battery Performance.

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Minjeong; Wu, Heng-Liang; Narayanan, Badri; See, Kimberly A.; Assary, Rajeev S.; Zhu, Lingyang; Haasch, Richard T.; Zhang, Shuo; Zhang, Zhengcheng; Curtiss, Larry A.; Gewirth, Andrew A.

    2017-11-15

    We evaluate hydrofluoroether (HFE) cosolvents with varying degrees of fluorination in the acetonitrile-based solvate electrolyte to determine the effect of the HFE structure on the electrochemical performance of the Li-S battery. Solvates or sparingly solvating electrolytes are an interesting electrolyte choice for the Li-S battery due to their low polysulfide solubility. The solvate electrolyte with a stoichiometric ratio of LiTFSI salt in acetonitrile, (MeCN)(2)-LiTFSI, exhibits limited polysulfide solubility due to the high concentration of LiTFSI. We demonstrate that the addition of highly fluorinated HFEs to the solvate yields better capacity retention compared to that of less fluorinated HFE cosolvents. Raman and NMR spectroscopy coupled with ab initio molecular dynamics simulations show that HFEs exhibiting a higher degree of fluorination coordinate to Li+ at the expense of MeCN coordination, resulting in higher free MeCN content in solution. However, the polysulfide solubility remains low, and no crossover of polysulfides from the S cathode to the Li anode is observed.

  10. Dual phase polymer gel electrolyte based on non-woven poly(vinylidenefluoride-co-hexafluoropropylene)–layered clay nanocomposite fibrous membranes for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Shubha, Nageswaran [School of Materials Science and Engineering, Nanyang Technological University, Block N4.1, 50 Nanyang Avenue, Singapore 639798 (Singapore); Prasanth, Raghavan [School of Materials Science and Engineering, Nanyang Technological University, Block N4.1, 50 Nanyang Avenue, Singapore 639798 (Singapore); Energy Research Institute - NTU (ERI-N) Research Techno Plaza, 50 Nanyang Drive, Singapore 637553 (Singapore); TUM-CREATE Center for Electromobility, Nanyang Technological University, Singapore 637553 (Singapore); Hoon, Hng Huey [School of Materials Science and Engineering, Nanyang Technological University, Block N4.1, 50 Nanyang Avenue, Singapore 639798 (Singapore); Srinivasan, Madhavi, E-mail: madhavi@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, Block N4.1, 50 Nanyang Avenue, Singapore 639798 (Singapore); Energy Research Institute - NTU (ERI-N) Research Techno Plaza, 50 Nanyang Drive, Singapore 637553 (Singapore); TUM-CREATE Center for Electromobility, Nanyang Technological University, Singapore 637553 (Singapore)

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ► P(VdF-co-HFP)–clay nanocomposite based electrospun membranes are prepared. ► The membranes are used as polymer gel electrolyte (PGE) in lithium ion batteries. ► The composite PGE shows ionic conductivity of 5.5 mS cm{sup −1} at room temperature. ► Li/PGE/LiFePO{sub 4} cell delivers initial discharge capacity of 160 mAh g{sup −1}. ► The use of prepared electrolyte significantly improved the cell performance. -- Abstract: A new approach for fabricating polymer gel electrolytes (PGEs) based on electrospun poly(vinylidenefluoride-co-hexafluoropropylene) (P(VdF-co-HFP)) incorporated with layered nanoclay has been employed to enhance the ionic conductivity and electrochemical properties of P(VdF-co-HFP) without compromising its mechanical strength. The effect of layered nanoclay on properties of membranes has been evaluated by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Surface morphology of the membranes has been studied using field-emission scanning electron microscopy (FE-SEM). Polymer gel electrolytes are prepared by soaking the fibrous membrane into 1 M LiPF{sub 6} in EC/DEC. The electrochemical studies show that incorporation of layered nanoclay into the polymer matrix greatly enhanced the ionic conductivity and compatibility with lithium electrodes. The charge–discharge properties and cycling performance of Li/LiFePO{sub 4} cells comprising nanocomposite polymer gel electrolytes have been evaluated at room temperature.

  11. Dual phase polymer gel electrolyte based on non-woven poly(vinylidenefluoride-co-hexafluoropropylene)–layered clay nanocomposite fibrous membranes for lithium ion batteries

    International Nuclear Information System (INIS)

    Shubha, Nageswaran; Prasanth, Raghavan; Hoon, Hng Huey; Srinivasan, Madhavi

    2013-01-01

    Graphical abstract: Display Omitted Highlights: ► P(VdF-co-HFP)–clay nanocomposite based electrospun membranes are prepared. ► The membranes are used as polymer gel electrolyte (PGE) in lithium ion batteries. ► The composite PGE shows ionic conductivity of 5.5 mS cm −1 at room temperature. ► Li/PGE/LiFePO 4 cell delivers initial discharge capacity of 160 mAh g −1 . ► The use of prepared electrolyte significantly improved the cell performance. -- Abstract: A new approach for fabricating polymer gel electrolytes (PGEs) based on electrospun poly(vinylidenefluoride-co-hexafluoropropylene) (P(VdF-co-HFP)) incorporated with layered nanoclay has been employed to enhance the ionic conductivity and electrochemical properties of P(VdF-co-HFP) without compromising its mechanical strength. The effect of layered nanoclay on properties of membranes has been evaluated by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Surface morphology of the membranes has been studied using field-emission scanning electron microscopy (FE-SEM). Polymer gel electrolytes are prepared by soaking the fibrous membrane into 1 M LiPF 6 in EC/DEC. The electrochemical studies show that incorporation of layered nanoclay into the polymer matrix greatly enhanced the ionic conductivity and compatibility with lithium electrodes. The charge–discharge properties and cycling performance of Li/LiFePO 4 cells comprising nanocomposite polymer gel electrolytes have been evaluated at room temperature.

  12. Development of batch electrolytic enrichment cells with 100-fold volume reduction, control electronic units and neutralization/distillation unit, to enable better sensitivity to be achieved in low-level tritium measurements when liquid scintillation counting follows the enrichment process

    International Nuclear Information System (INIS)

    Taylor, C.B.

    1980-06-01

    Full details of the batch-cell tritium enrichment system design are provided including electronic control circuits specially developed for these cells. The system incorporates a new type of concentric electrode cell (outer cathode of mild steel, anode of stainless steel, inner cathode of mild steel) with volume reduction capability 1 l to ca 9 ml. Electrolysis of 20 cells is performed in 2 steps. Down to sample volume ca 20 ml, the cells are series connected at constant currents up to 14.5 A, in the 2nd step, each cell is connected to its own individual current supply (2A) and control circuit. Automatic shut-off at the desired final volume is achieved by sensing the drop in current through the inner cathode as the electrolyte level falls below a PTFE insulator. The large electrode surface area and careful dimensioning at the foot of the cell allow operation with low starting electrolyte concentration 1.5 g Na 2 O 2 .l -1 . After electrolysis, quantitative recovery as distilled water of all hydrogen from the enriched residue is achieved by CO 2 -neutralisation and vacuum distillation at 100 0 C in a distillation unit which handles 20 cells simultaneously

  13. DNA bases assembled on the Au(110)/electrolyte interface: A combined experimental and theoretical study

    DEFF Research Database (Denmark)

    Salvatore, Princia; Nazmutdinov, Renat R.; Ulstrup, Jens

    2015-01-01

    , accompanied by a pair of strong voltammetry peaks in the double-layer region in acid solutions. Adsorption of the DNA bases gives featureless voltammograms with lower double-layer capacitance, suggesting that all the bases are chemisorbed on the Au(110) surface. Further investigation of the surface structures...... of the adlayers of the four DNA bases by EC-STM disclosed lifting of the Au(110) reconstruction, specific molecular packing in dense monolayers, and pH dependence of the A and G adsorption. DFT computations based on a cluster model for the Au(110) surface were performed to investigate the adsorption energy...... and geometry of the DNA bases in different adsorbate orientations. The optimized geometry is further used to compute models for STM images which are compared with the recorded STM images. This has provided insight into the physical nature of the adsorption. The specific orientations of A, C, G, and T on Au(110...

  14. Novel composite membranes based on PBI and dicationic ionic liquids for high temperature polymer electrolyte membrane fuel cells

    International Nuclear Information System (INIS)

    Hooshyari, Khadijeh; Javanbakht, Mehran; Adibi, Mina

    2016-01-01

    Two types of innovative composite membranes based on polybenzimidazole (PBI) containing dicationic ionic liquid 1,3-di(3-methylimidazolium) propane bis (trifluoromethylsulfonyl) imide (PDC 3 ) and monocationic ionic liquid 1-hexyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide (PMC 6 ) are prepared as electrolyte for high temperature fuel cells applications under anhydrous conditions. The analyses of results display promising characteristics such as high proton conductivity and thermal stability. Moreover the fuel cell performance of PA doped PDC 3 composite membranes is enhanced in comparison with PA doped PMC 6 and PA doped PBI membranes at high temperatures. Dicationic ionic liquid with high number of charge carriers provides well-developed ionic channels which form facile pathways and considerably develop the anhydrous proton conductivity. The highest proton conductivity of 81 mS/cm is achieved for PA doped PDC 3 composite membranes with PBI/IL mole ratio: 4 at 180 °C. A power density of 0.44 W/cm 2 is obtained at 0.5 V and 180 °C for PA doped PDC 3 composite membranes, which proves that these developed composite membranes can be considered as most promising candidates for high temperature fuel cell applications with enhanced proton conductivity.

  15. Model-based diagnosis through Structural Analysis and Causal Computation for automotive Polymer Electrolyte Membrane Fuel Cell systems

    Science.gov (United States)

    Polverino, Pierpaolo; Frisk, Erik; Jung, Daniel; Krysander, Mattias; Pianese, Cesare

    2017-07-01

    The present paper proposes an advanced approach for Polymer Electrolyte Membrane Fuel Cell (PEMFC) systems fault detection and isolation through a model-based diagnostic algorithm. The considered algorithm is developed upon a lumped parameter model simulating a whole PEMFC system oriented towards automotive applications. This model is inspired by other models available in the literature, with further attention to stack thermal dynamics and water management. The developed model is analysed by means of Structural Analysis, to identify the correlations among involved physical variables, defined equations and a set of faults which may occur in the system (related to both auxiliary components malfunctions and stack degradation phenomena). Residual generators are designed by means of Causal Computation analysis and the maximum theoretical fault isolability, achievable with a minimal number of installed sensors, is investigated. The achieved results proved the capability of the algorithm to theoretically detect and isolate almost all faults with the only use of stack voltage and temperature sensors, with significant advantages from an industrial point of view. The effective fault isolability is proved through fault simulations at a specific fault magnitude with an advanced residual evaluation technique, to consider quantitative residual deviations from normal conditions and achieve univocal fault isolation.

  16. Structural and ionic conductivity studies on proton conducting solid biopolymer electrolyte based on 2hydroxyethyl cellulose incorporated DTAB

    Science.gov (United States)

    Ahmad, N. H.; Bakar, N. Y.; Isa, M. I. N.

    2017-09-01

    Solid biopolymer electrolytes (SBEs) based on 2hydroxyethyl cellulose (2HEC) complexes with dodecyltrimethyl ammonium bromide (DTAB) salt in various composition (wt. %) were successfully prepared by using solution casting technique. The ion - polymer interaction and structural studies have been reported by Fourier transform infrared spectroscopy (FTIR) supported with X - ray diffraction (XRD) and Electrical impedance spectroscopy (EIS). FTIR spectral shows interaction of 2HEC with DTAB happen at peak 2914cm-1, 2848cm-1, 2353cm-1, 2328cm-1, 1720cm-1, 1437cm-1, 1344cm-1, 1198cm-1 1095cm-1 1051cm-1, 912cm-1 and 872cm-1. The interaction of complexes leads to an increase in number of ion jump into neighboring vacant sites until it reaches the highest conductivity at room temperature which is 2.80 x 10-5 Scm-1 for sample containing 9wt. % of DTAB. The temperature dependence of the SBEs system exhibits Arrhenius behavior and the XRD spectral analysis shows the higher salt loading the crystallinity of the SBEs which also increased.

  17. Amphoteric water as acid and base for protic ionic liquids and their electrochemical activity when used as fuel cell electrolytes.

    Science.gov (United States)

    Miran, Muhammed Shah; Yasuda, Tomohiro; Tatara, Ryoichi; Abu Bin Hasan Susan, Md; Watanabe, Masayoshi

    2017-12-14

    Amphoteric water was mixed with equimolar amounts of a super-strong acid, trifluoromethanesulfonic acid (TfOH), and a super-strong base, 1,8-diazabicyclo[5.4.0]-7-undecene (DBU). Bulk physicochemical and electrochemical properties of the mixtures were compared with those of the best ever reported protic ionic liquid (PIL), diethylmethylammonium trifluoromethanesulfonate ([dema][TfO]), which has excellent physicochemical properties as a fuel cell electrolyte. The acidic mixture ([H 3 O][TfO]) behaved as a protic ionic liquid, while the basic mixture ([DBU]OH) showed incomplete proton transfer. The Walden plot indicated that [H 3 O][TfO] behaves as a good PIL, similar to [dema][TfO], whereas [DBU]OH behaves as a poor PIL. [H 3 O][TfO] showed excellent H 2 /O 2 fuel cell performance at 80 °C; however, the performance deteriorated as the bulk water content increased, because of the retardation of the electrode kinetics due to the oxidation of Pt in the presence of bulk water. On the other hand, [DBU]OH exhibited very poor performance possibly because of the existence of neutral species in the system.

  18. Electrodeposition of In{sub 2}O{sub 3} thin films from a dimethylsulfoxide based electrolytic solution

    Energy Technology Data Exchange (ETDEWEB)

    Henriquez, R.; Munoz, E.; Gomez, H. [Instituto de Quimica, Facultad de Ciencias, Pontificia Universidad Catolica de Valparaiso, Curauma Valparaiso (Chile); Dalchiele, E.A.; Marotti, R.E. [Instituto de Fisica and CINQUIFIMA, Facultad de Ingenieria, Montevideo (Uruguay); Martin, F.; Leinen, D.; Ramos-Barrado, J.R. [Laboratorio de Materiales y Superficie, Departamento de Fisica Aplicada and Ingenieria Quimica, Universidad de Malaga (Spain)

    2013-02-15

    Indium (III) oxide (In{sub 2}O{sub 3}) thin films have been obtained after heat treatment of In(OH){sub 3} precursor layers grown by a potential cycling electrodeposition (PCED) method from a dimethylsulfoxide (DMSO) based electrolytic solution onto fluorine-doped tin oxide (FTO) coated glass substrates. X-ray diffraction (XRD) measurements indicate the formation of a polycrystalline In{sub 2}O{sub 3} phase with a cubic structure. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed a smooth morphology of the In{sub 2}O{sub 3} thin films after an optimized heat treatment had been developed. The surface composition and chemical state of the semiconductor films was established by X-ray photoelectron spectroscopy analysis. The nature of the semiconductor material, flat band potential and donor density were determined from Mott-Schottky plots. This study reveals that the In{sub 2}O{sub 3} films exhibited n-type conductivity with an average donor density of 2.2 x 10{sup 17} cm{sup -3}. The optical characteristics were determined through transmittance spectra. The direct and indirect band gap values obtained are according to the accepted values for the In{sub 2}O{sub 3} films of 2.83 and 3.54 eV for the indirect and direct band gap values. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Improvement of N-phthaloylchitosan based gel polymer electrolyte in dye-sensitized solar cells using a binary salt system.

    Science.gov (United States)

    Yusuf, S N F; Azzahari, A D; Selvanathan, V; Yahya, R; Careem, M A; Arof, A K

    2017-02-10

    A binary salt system utilizing lithium iodide (LiI) as the auxiliary component has been introduced to the N-phthaloylchitosan (PhCh) based gel polymer electrolyte consisting of ethylene carbonate (EC), dimethylformamide (DMF), tetrapropylammonium iodide (TPAI), and iodine (I 2 ) in order to improve the performance of dye-sensitized solar cell (DSSC) with efficiency of 6.36%, photocurrent density, J SC of 17.29mAcm -2 , open circuit voltage, V OC of 0.59V and fill factor, FF of 0.62. This efficiency value is an improvement from the 5.00% performance obtained by the DSSC consisting of only TPAI single salt system. The presence of the LiI in addition to the TPAI improves the charge injection rates and increases the iodide contribution to the total conductivity and both factors contribute to the increase in efficiency of the DSSC. The interaction behavior between polymer-plasticizer-salt was thoroughly investigated using EIS, FTIR spectroscopy and XRD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Self-supported poly(methyl methacrylate-acrylonitrile-vinyl acetate)-based gel electrolyte for lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Y.H.; Zhou, D.Y.; Rao, M.M.; Cai, Z.P.; Liang, Y. [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Li, W.S.; Tan, C.L. [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Key Lab of Electrochemical Technology on Energy Storage and Power Generation in Guangdong Universities, Guangzhou 510006 (China)

    2009-04-01

    Self-supported gel polymer electrolyte (GPE) was prepared based on copolymer, poly(methyl methacrylate-acrylonitrile-vinyl acetate) (P(MMA-AN-VAc)). The copolymer P(MMA-AN-VAc) was synthesized by emulsion polymerization and the copolymer membrane was prepared through phase inversion. The structure and the performance of the copolymer, the membrane and the GPE were characterized by FTIR, NMR, SEM, XRD, DSC/TG, LSV, CA, and EIS. It is found that the copolymer was formed through the breaking of double bond C=C in each monomer. The membrane has low crystallinity and has low glass transition temperature, 39.1 C, its thermal stability is as high as 310 C, and its mechanical strength is improved compared with P(MMA-AN). The GPE is electrochemically stable up to 5.6 V (vs. Li/Li{sup +}) and its conductivity is 3.48 x 10{sup -3} S cm{sup -1} at ambient temperature. The lithium ion transference number in the GPE is 0.51 and the conductivity model of the GPE is found to obey the Vogel-Tamman-Fulcher (VTF) equation. (author)

  1. Platinum nanoparticles on carbon-nanotube support prepared by room-temperature reduction with H2 in ethylene glycol/water mixed solvent as catalysts for polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Zheng, Yuying; Dou, Zhengjie; Fang, Yanxiong; Li, Muwu; Wu, Xin; Zeng, Jianhuang; Hou, Zhaohui; Liao, Shijun

    2016-02-01

    Polyol approach is commonly used in synthesizing Pt nanoparticles in polymer electrolyte membrane fuel cells. However, the application of this process consumes a great deal of time and energy, as the reduction of precursors requires elevated temperatures and several hours. Moreover, the ethylene glycol and its oxidizing products bound to Pt are difficult to remove. In this work, we utilize the advantages of ethylene glycol and prepare Pt nanoparticles through a room-temperature hydrogen gas reduction in an ethylene glycol/water mixed solvent, which is followed by subsequent harvesting by carbon nanotubes as electrocatalysts. This method is simple, facile, and time-efficient, as the entire room-temperature reduction process is completed in a few minutes. As the solvent changes from water to an ethylene glycol/water mix, the size of Pt nanoparticles varies from 10 to 3 nm and their shape transitions from polyhedral to spherical. Pt nanoparticles prepared in a 1:1 volume ratio mixture of ethylene glycol/water are uniformly dispersed with an average size of ∼3 nm. The optimized carbon nanotube-supported Pt electrocatalyst exhibits excellent methanol oxidation and oxygen reduction activities. This work demonstrates the potential use of mixed solvents as an approach in materials synthesis.

  2. Comprehensive study of efficient dye-sensitized solar cells based on the binary ionic liquid electrolyte by modifying with additives and iodine

    Science.gov (United States)

    Mo, Ao-qiang; Cao, Da-peng; Wang, Wu-yang; Li, Xue-yan; Mi, Bao-xiu; Gao, Zhi-qiang; Liang, Zhong-cheng

    2017-07-01

    The photovoltaic performance of dye-sensitized solar cells (DSSCs) is enhanced by modifying the binary room temperature ionic liquid (RTIL) electrolyte with additives and iodine. The average photoelectric conversion efficiency ( PCE) of 6.39% is achieved. Through electrochemical impedance spectroscopy (EIS), cyclic voltammetry scans and incident photon-to-current conversion efficiency ( IPCE) data, the working principles are analyzed. The enhancement is mainly attributed to the improvement of short circuit current which is caused by the reduction of overall internal resistance of the devices. Durability tests are measured at room temperature, and the long-term stability performance can be maintained.

  3. a human rights-based approach to poverty reduction

    African Journals Online (AJOL)

    NWUuser

    poverty. This will be done firstly by discussing the human rights-based approach to poverty reduction,15 whereafter attention will be turned to access to medicines ... Benzeval et al "Relationships between Health, Income and Poverty" 78; Spicker et al Poverty 91; ...... Corrective and Distributive Justice (PULP Pretoria 2009) ...

  4. Novel Electrolytes for Lithium Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lucht, Brett L. [Univ. of Rhode Island, Kingston, RI (United States). Dept. of Chemistry

    2014-12-12

    We have been investigating three primary areas related to lithium ion battery electrolytes. First, we have been investigating the thermal stability of novel electrolytes for lithium ion batteries, in particular borate based salts. Second, we have been investigating novel additives to improve the calendar life of lithium ion batteries. Third, we have been investigating the thermal decomposition reactions of electrolytes for lithium-oxygen batteries.

  5. CuZn Alloy- Based Electrocatalyst for CO2 Reduction

    KAUST Repository

    Alazmi, Amira

    2014-06-01

    ABSTRACT CuZn Alloy- Based Electrocatalyst for CO2 Reduction Amira Alazmi Carbon dioxide (CO2) is one of the major greenhouse gases and its emission is a significant threat to global economy and sustainability. Efficient CO2 conversion leads to utilization of CO2 as a carbon feedstock, but activating the most stable carbon-based molecule, CO2, is a challenging task. Electrochemical conversion of CO2 is considered to be the beneficial approach to generate carbon-containing fuels directly from CO2, especially when the electronic energy is derived from renewable energies, such as solar, wind, geo-thermal and tidal. To achieve this goal, the development of an efficient electrocatalyst for CO2 reduction is essential. In this thesis, studies on CuZn alloys with heat treatments at different temperatures have been evaluated as electrocatalysts for CO2 reduction. It was found that the catalytic activity of these electrodes was strongly dependent on the thermal oxidation temperature before their use for electrochemical measurements. The polycrystalline CuZn electrode without thermal treatment shows the Faradaic efficiency for CO formation of only 30% at applied potential ~−1.0 V vs. RHE with current density of ~−2.55 mA cm−2. In contrast, the reduction of oxide-based CuZn alloy electrode exhibits 65% Faradaic efficiency for CO at lower applied potential about −1.0 V vs. RHE with current density of −2.55 mA cm−2. Furthermore, stable activity was achieved over several hours of the reduction reaction at the modified electrodes. Based on electrokinetic studies, this improvement could be attributed to further stabilization of the CO2•− on the oxide-based Cu-Zn alloy surface.

  6. New Class of LAGP-Based Solid Polymer Composite Electrolyte for Efficient and Safe Solid-State Lithium Batteries.

    Science.gov (United States)

    Guo, Qingpeng; Han, Yu; Wang, Hui; Xiong, Shizhao; Li, Yujie; Liu, Shuangke; Xie, Kai

    2017-12-06

    Inorganic solid electrolytes (SEs) possess substantial safety and electrochemical stability, which make them as key components of safe rechargeable solid-state Li batteries with high energy density. However, complicated integrally molding process and poor wettability between SEs and active materials are the most challenging barriers for the application of SEs. In this regard, we explore composite SEs of the active ceramic Li 1+x Al x Ge 2-x (PO 4 ) 3 (LAGP) as the main medium for ion conduction and the polymer P(VDF-HFP) as a matrix. Meanwhile, for the first time, we choice high chemical, thermal, and electrochemical stability of ionic liquid swelled in polymer, which significantly ameliorate the interface in the cell. In addition, a reduced crystallinity degree of the polymer in the electrolyte can also be achieved. All of these lead to good ionic conductivity of the composite electrolyte (LPELCE), at the same time, good compatibility with the lithium electrode. Especially, high mechanical strength and stable solid electrolyte interphase which suppressed the growth of lithium dendrites and high thermal safety stability can also be observed. For further illustration, the solid-state lithium battery of LiFePO 4 /LPELCE/Li shows relatively satisfactory performance, indicating the promising potentials of using this type of electrolyte to develop high safety and high energy density solid-state lithium batteries.

  7. New cross-linked PVA based polymer electrolyte membranes for alkaline fuel cells

    NARCIS (Netherlands)

    Merle, Geraldine; Hosseiny, Seyed Schwan; Wessling, Matthias; Nijmeijer, Dorothea C.

    2012-01-01

    In this paper, we report a cheap and easy method for the preparation of anion exchange membranes based on a KOH doped and crosslinked poly(vinyl alcohol) (PVA) for alkaline fuel cells. Ionic conductivity and thermal and chemical stability are investigated as a function of the crosslinking density.

  8. A quasi-direct methanol fuel cell system based on blend polymer membrane electrolytes

    DEFF Research Database (Denmark)

    Li, Qingfeng; Hjuler, Hans Aage; Hasiotis, C.

    2002-01-01

    , compared to less than 100 ppm CO for the Nafion-based technology at 80degrees C. The high CO tolerance makes it possible to use the reformed hydrogen directly from a simple methanol reformer without further CO removal. That both the fuel cell and the methanol reformer operate at temperatures around 200...

  9. Microporous SiO2-based solid electrolyte with improved polarization response for 0.8 V transparent thin-film transistors

    International Nuclear Information System (INIS)

    Sun Jia; Jiang Jie; Lu Aixia; Wan Qing

    2010-01-01

    The polarization mechanism of a microporous SiO 2 -based solid electrolyte is developed and three polarizations (electric double layer formation, ionic relaxation and dipole relaxation) are identified. The polarization response of the microporous SiO 2 -based solid electrolyte is optimized by tuning the deposition temperature and the improved specific capacitance is 1 μF cm -2 at 1 kHz and remains above 0.6 μF cm -2 even at 10 kHz. Ultralow-voltage transparent In-Zn-O thin-film transistors (TFTs) gated by such dielectrics are fabricated at low temperatures. The field-effect mobility, current on/off ratio and subthreshold swing are estimated to be 46.2 cm 2 V -1 s -1 , ∼10 6 and 69 mV/decade, respectively. Such TFTs hold promise for portable electronic applications.

  10. Microporous SiO{sub 2}-based solid electrolyte with improved polarization response for 0.8 V transparent thin-film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Sun Jia; Jiang Jie; Lu Aixia; Wan Qing, E-mail: wanqing7686@hotmail.co [Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education, and State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China)

    2010-07-28

    The polarization mechanism of a microporous SiO{sub 2}-based solid electrolyte is developed and three polarizations (electric double layer formation, ionic relaxation and dipole relaxation) are identified. The polarization response of the microporous SiO{sub 2}-based solid electrolyte is optimized by tuning the deposition temperature and the improved specific capacitance is 1 {mu}F cm{sup -2} at 1 kHz and remains above 0.6 {mu}F cm{sup -2} even at 10 kHz. Ultralow-voltage transparent In-Zn-O thin-film transistors (TFTs) gated by such dielectrics are fabricated at low temperatures. The field-effect mobility, current on/off ratio and subthreshold swing are estimated to be 46.2 cm{sup 2} V{sup -1} s{sup -1}, {approx}10{sup 6} and 69 mV/decade, respectively. Such TFTs hold promise for portable electronic applications.

  11. Jacques Loeb (1859-1924) and His Forgotten Contributions to Electrolyte and Acid-Base Physiology in The Organism as a Whole.

    Science.gov (United States)

    Sgambato, Francesco; Sgambato, Ester; De Santo, Natale Gaspare

    2016-02-01

    Jacques Loeb (1859-1924) was the founder of the Journal of General Physiology which he co-directed in association with W.J.V. Osterhout in the years 1918-1924. Having worked (1889-1891)at the Marine Zoological Station of Naples, newly founded by Anton Dohrn, he was imprinted for life. A strong investigator used to perform the experiments personally. Loeb was engaged lifelong in the explanation of life on physico-chemical basis. He touched various fields (being a creative scientist full of ideas), and centered on the exchanges of electrolytes, acids and bases between the body and sea water in fish. He identified two equations: {[K+]+[Na+]}: {[Ca++]+[Mg++]} (Loebs 1st equation) {[K+]+[Na+]}: {[H+]+[Ca++]+[Mg++]} (Loebs final equation) Even nowadays these equations may have applications in a wide list of electrolyte and acid-base disturbances. Unfortunately his heredity has been dissipated.

  12. Colloidal Electrolytes and the Critical Micelle Concentration

    Science.gov (United States)

    Knowlton, L. G.

    1970-01-01

    Describes methods for determining the Critical Micelle Concentration of Colloidal Electrolytes; methods described are: (1) methods based on Colligative Properties, (2) methods based on the Electrical Conductivity of Colloidal Electrolytic Solutions, (3) Dye Method, (4) Dye Solubilization Method, and (5) Surface Tension Method. (BR)

  13. SVM-based glioma grading. Optimization by feature reduction analysis

    International Nuclear Information System (INIS)

    Zoellner, Frank G.; Schad, Lothar R.; Emblem, Kyrre E.; Harvard Medical School, Boston, MA; Oslo Univ. Hospital

    2012-01-01

    We investigated the predictive power of feature reduction analysis approaches in support vector machine (SVM)-based classification of glioma grade. In 101 untreated glioma patients, three analytic approaches were evaluated to derive an optimal reduction in features; (i) Pearson's correlation coefficients (PCC), (ii) principal component analysis (PCA) and (iii) independent component analysis (ICA). Tumor grading was performed using a previously reported SVM approach including whole-tumor cerebral blood volume (CBV) histograms and patient age. Best classification accuracy was found using PCA at 85% (sensitivity = 89%, specificity = 84%) when reducing the feature vector from 101 (100-bins rCBV histogram + age) to 3 principal components. In comparison, classification accuracy by PCC was 82% (89%, 77%, 2 dimensions) and 79% by ICA (87%, 75%, 9 dimensions). For improved speed (up to 30%) and simplicity, feature reduction by all three methods provided similar classification accuracy to literature values (∝87%) while reducing the number of features by up to 98%. (orig.)

  14. Analyses of ionic conductivity and dielectric behavior of solid polymer electrolyte based 2-hydroxyethyl cellulose doped ammonium nitrate plasticized with ethylene carbonate

    Science.gov (United States)

    Hafiza, M. N.; Isa, M. I. N.

    2017-09-01

    A solid polymer electrolyte (SPE) based 2-hydroxyethyl cellulose (2-HEC) doped ammonium nitrate (NH4NO3) plasticized with ethylene carbonate (EC) has been investigated using electrical impedance spectroscopy (EIS). The highest ionic conductivity of (1.17±0.01) × 10-3 Scm-1 was obtained for 2-HEC-NH4NO3 plasticized with 16 wt.% EC. Dielectric and modulus study showed non-Debye type of 2-HEC-NH4NO3-EC SPE.

  15. TPSLVM: a dimensionality reduction algorithm based on thin plate splines.

    Science.gov (United States)

    Jiang, Xinwei; Gao, Junbin; Wang, Tianjiang; Shi, Daming

    2014-10-01

    Dimensionality reduction (DR) has been considered as one of the most significant tools for data analysis. One type of DR algorithms is based on latent variable models (LVM). LVM-based models can handle the preimage problem easily. In this paper we propose a new LVM-based DR model, named thin plate spline latent variable model (TPSLVM). Compared to the well-known Gaussian process latent variable model (GPLVM), our proposed TPSLVM is more powerful especially when the dimensionality of the latent space is low. Also, TPSLVM is robust to shift and rotation. This paper investigates two extensions of TPSLVM, i.e., the back-constrained TPSLVM (BC-TPSLVM) and TPSLVM with dynamics (TPSLVM-DM) as well as their combination BC-TPSLVM-DM. Experimental results show that TPSLVM and its extensions provide better data visualization and more efficient dimensionality reduction compared to PCA, GPLVM, ISOMAP, etc.

  16. Digital power and performance analysis of inkjet printed ring oscillators based on electrolyte-gated oxide electronics

    Science.gov (United States)

    Cadilha Marques, Gabriel; Garlapati, Suresh Kumar; Dehm, Simone; Dasgupta, Subho; Hahn, Horst; Tahoori, Mehdi; Aghassi-Hagmann, Jasmin

    2017-09-01

    Printed electronic components offer certain technological advantages over their silicon based counterparts, like mechanical flexibility, low process temperatures, maskless and additive manufacturing possibilities. However, to be compatible to the fields of smart sensors, Internet of Things, and wearables, it is essential that devices operate at small supply voltages. In printed electronics, mostly silicon dioxide or organic dielectrics with low dielectric constants have been used as gate isolators, which in turn have resulted in high power transistors operable only at tens of volts. Here, we present inkjet printed circuits which are able to operate at supply voltages as low as ≤2 V. Our transistor technology is based on lithographically patterned drive electrodes, the dimensions of which are carefully kept well within the printing resolutions; the oxide semiconductor, the electrolytic insulator and the top-gate electrodes have been inkjet printed. Our inverters show a gain of ˜4 and 2.3 ms propagation delay time at 1 V supply voltage. Subsequently built 3-stage ring oscillators start to oscillate at a supply voltage of only 0.6 V with a frequency of ˜255 Hz and can reach frequencies up to ˜350 Hz at 2 V supply voltage. Furthermore, we have introduced a systematic methodology for characterizing ring oscillators in the printed electronics domain, which has been largely missing. Benefiting from this procedure, we are now able to predict the switching capacitance and driver capability at each stage, as well as the power consumption of our inkjet printed ring oscillators. These achievements will be essential for analyzing the performance and power characteristics of future inkjet printed digital circuits.

  17. Fuel cells with solid polymer electrolyte and their application on vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Fateev, V.

    1996-04-01

    In Russia, solid polymer electrolyte MF-4-SK has been developed for fuel cells. This electrolyte is based on perfluorinated polymer with functional sulfogroups. Investigations on electrolyte properties and electrocatalysts have been carried out.

  18. Fluorine-free electrolytes for all-solid sodium-ion batteries based on percyano-substituted organic salts

    OpenAIRE

    Anna Bitner-Michalska; Gene M. Nolis; Grażyna Żukowska; Aldona Zalewska; Marcin Poterała; Tomasz Trzeciak; Maciej Dranka; Michał Kalita; Piotr Jankowski; Leszek Niedzicki; Janusz Zachara; Marek Marcinek; Władysław Wieczorek

    2017-01-01

    A new family of fluorine-free solid-polymer electrolytes, for use in sodium-ion battery applications, is presented. Three novel sodium salts withdiffuse negative charges: sodium pentacyanopropenide (NaPCPI), sodium 2,3,4,5-tetracyanopirolate (NaTCP) and sodium 2,4,5-tricyanoimidazolate (NaTIM) were designed andtested in a poly(ethylene oxide) (PEO) matrix as polymer electrolytes for anall-solid sodium-ion battery. Due to unique, non-covalent structural configurations of anions, improved ionic...

  19. Ion transport phenomena in polymeric electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Ciosek, M.; Sannier, L.; Siekierski, M.; Wieczorek, W. [Warsaw University of Technology, Faculty of Chemistry, Noakowskiego 3, 00-664 Warsaw (Poland); Golodnitsky, D.; Peled, E. [School of Chemistry, Tel Aviv University, Tel Aviv 69978 (Israel); Scrosati, B. [Dipartimento di Chimica, Universita di Roma ' ' La Sapienza' ' , P. le A. Moro 4, 00185 Rome (Italy); Glowinkowski, S. [Faculty of Physics, Adam Mickiewicz University, Ulmultowska 86, 61-614 Poznan (Poland)

    2007-12-31

    The aim of the present work is to generalize an ion transport phenomena observed in composite polymeric electrolytes using the previously developed models as well as design a new approach which would be helpful in describing changes in conductivity and lithium ion transference numbers occurring upon addition of fillers to polymeric electrolytes. The concept is based on the observation of changes in ionic associations in the polymeric electrolytes studied in a wide salt concentration range. The idea is illustrated by the results coming from a variety of electrochemical and structural data obtained for composite electrolytes containing specially designed inorganic and organic fillers. (author)

  20. Influence of electrolyte distribution in PEDOT:PSS based flexible electrochromic devices

    Science.gov (United States)

    Gavim, Anderson E. X.; Santos, Gustavo H.; de Souza, Edgar H.; Rodrigues, Paula C.; Floriano, João B.; Kamikawachi, Ricardo C.; de Deus, Jeferson F.; Macedo, Andreia G.

    2017-12-01

    Two flexible electrochromic devices based on PEDOT:PSS were prepared by roll-to-roll method, these devices were built with the conventional layered geometry or using PEO:LiClO4 and charge balancing material mixed at the same layer. Analysis of the properties leads to the conclusion that the presence of the percolation channels of PEDOT:PSS inside the PEO/LiClO4 results in the performance improvement as monitored by impedance spectroscopy and the respective Randles equivalent circuits. From mixed electrochromic layer, ηd increases up to 834 C-1 cm2 after 1.5 s of switch time, while the corresponding layered device showed ηd of 472 C-1 cm2 at the same time interval.

  1. Center for BioBased Binders and Pollution Reduction Technology

    Energy Technology Data Exchange (ETDEWEB)

    Thiel, Jerry [Univ. of Northern Iowa, Cedar Falls, IA (United States)

    2013-07-01

    Funding will support the continuation of the Center for Advanced Bio-based Binders and Pollution Reduction Technology Center (CABB) in the development of bio-based polymers and emission reduction technologies for the metal casting industry. Since the formation of the center several new polymers based on agricultural materials have been developed. These new materials have show decreases in hazardous air pollutants, phenol and formaldehyde as much as 50 to 80% respectively. The polymers termed bio-polymers show a great potential to utilize current renewable agricultural resources to replace petroleum based products and reduce our dependence on importing of foreign oil. The agricultural technology has shown drastic reductions in the emission of hazardous air pollutants and volatile organic compounds and requires further development to maintain competitive costs and productivity. The project will also research new and improved inorganic binders that promise to eliminate hazardous emissions from foundry casting operations and allow for the beneficial reuse of the materials and avoiding the burdening of overcrowded landfills.

  2. Initial study of Nickel Electrolyte for EnFACE Process

    Directory of Open Access Journals (Sweden)

    Tri Widayatno

    2015-03-01

    Full Text Available Nickel electrolyte for a micro-pattern transfer process without photolithography, EnFACE, has been developed. Previous work on copper deposition indicated that a conductivity of ~2.7 Sm-1 is required. Electrochemical parameters of electrolyte i.e. current density and overpotential are also crucial to govern a successful pattern replication. Therefore, the investigation focused on the measurement of physicochemical properties and electrochemical behaviour of the electrolyte at different nickel concentrations and complexing agents of chloride and sulfamate. Nickel electrolytes containing sulfamate, chloride and combined sulfamate-chloride with concentrations between 0.14 M and 0.3 M were investigated. Physicochemical properties i.e. pH and conductivity were measured to ensure if they were in the desired value. The electrochemical behaviour of the electrolytes was measured by polarisation experiments in a standard three-electrode cell. The working electrode was a copper disc (surface area of 0.196 cm2 and the counter electrode was platinum mesh. The potential was measured againts a saturated calomel reference electrode (SCE. The experiments were carried out at various scan rate and Rotating Disc Electrode (RDE rotation speed to see the effect of scan rate and agitation. Based on the measured physicochemical properties, the electrolyte of 0.19 M nickel sulfamate was chosen for experimentation. Polarisation curve of agitated solution suggested that overall nickel electrodeposition reaction is controlled by a combination of kinetics and mass transfer.  Reduction potential of nickel was in the range of -0.7 to -1.0 V. The corresponding current densities for nickel deposition were in the range of -0.1 to -1.5 mA cm-2.

  3. Nanoscale CuO solid-electrolyte-based conductive-bridging, random-access memory cell with a TiN liner

    Science.gov (United States)

    Lee, Jong-Sun; Kim, Dong-Won; Kim, Hea-Jee; Jin, Soo-Min; Song, Myung-Jin; Kwon, Ki-Hyun; Park, Jea-Gun; Jalalah, Mohammed; Al-Hajry, Ali

    2018-01-01

    The Conductive-bridge random-access memory (CBRAM) cell is a promising candidate for a terabit-level non-volatile memory due to its remarkable advantages. We present for the first time TiN as a diffusion barrier in CBRAM cells for enhancing their reliability. CuO solid-electrolyte-based CBRAM cells implemented with a 0.1-nm TiN liner demonstrated better non-volatile memory characteristics such as 106 AC write/erase endurance cycles with 100-μs AC pulse width and a long retention time of 7.4-years at 85 °C. In addition, the analysis of Ag diffusion in the CBRAM cell suggests that the morphology of the Ag filaments in the electrolyte can be effectively controlled by tuning the thickness of the TiN liner. These promising results pave the way for faster commercialization of terabit-level non-volatile memories.

  4. Infrared studies of PVC-based electrolytes incorporated with lithium triflate and 1-butyl-3-methyl imidazolium trifluoromethanesulfonate as ionic liquid

    Science.gov (United States)

    Zulkepeli, Nik A. S. Nik; Winie, Tan; Subban, R. H. Y.

    2017-09-01

    In this work, 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BMIMCF3SO3) is employed as ionic liquid in PVC-based polymer electrolyte system with lithium triflate (LiCF3SO3) as doping salt. The samples in film form were prepared by quantitatively varying the concentration of BMIMCF3SO3 to a fixed ratio of PVC-LiCF3SO3 using solution cast technique. The highest room temperature ionic conductivity of 1.120 × 10-7 Scm-1 was exhibited by PVC-LiCF3SO3-BMIMCF3SO3 containing 3 wt. % BMIMCF3SO3. FTIR spectra of the polymer electrolytes were examined to study the complexation of the PVC-based polymer electrolytes. Intensity of free ions, ion pairs, and ion aggregates were obtained from FTIR deconvolution in an attempt to correlate with ionic conductivity results. The intensity of free ions was found to be high for sample with 3 wt. % BMIMCF3SO3.

  5. Assimilation of NH₄Br in Polyvinyl Alcohol/Poly(N-vinyl pyrrolidone) Polymer Blend-Based Electrolyte and Its Effect on Ionic Conductivity.

    Science.gov (United States)

    Parameswaran, V; Nallamuthu, N; Devendran, P; Manikandan, A; Nagarajan, E R

    2018-06-01

    Biodegradable polymer blend electrolyte based on ammonium based salt in variation composition consisting of PVA:PVP were prepared by using solution casting technique. The obtained films have been analyzed by various technical methods like as XRD, FT-IR, TG-DSC, SEM analysis and impedance spectroscopy. The XRD and FT-IR analysis exposed the amorphous nature and structural properties of the complex formation between PVA/PVP/NH4Br. Impedance spectroscopy analysis revealed the ionic conductivity and the dielectric properties of PVA/PVP/NH4Br polymer blend electrolyte films. The maximum ionic conductivity was determined to be 6.14 × 10-5 Scm-1 for the composition of 50%PVA: 50%PVP: 10% NH4Br with low activation energy 0.3457 eV at room temperature. Solid state battery is fabricated using highest ionic conducting polymer blend as electrolyte with the configuration Zn/ZnSO4 · 7H2O (anode) ∥ 50%PVA: 50%PVP: 10% NH4Br ∥ Mn2O3 (cathode). The observed open circuit voltage is 1.2 V and its performance has been studied.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-01

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

  7. Fast Reduction Method in Dominance-Based Information Systems

    Science.gov (United States)

    Li, Yan; Zhou, Qinghua; Wen, Yongchuan

    2018-01-01

    In real world applications, there are often some data with continuous values or preference-ordered values. Rough sets based on dominance relations can effectively deal with these kinds of data. Attribute reduction can be done in the framework of dominance-relation based approach to better extract decision rules. However, the computational cost of the dominance classes greatly affects the efficiency of attribute reduction and rule extraction. This paper presents an efficient method of computing dominance classes, and further compares it with traditional method with increasing attributes and samples. Experiments on UCI data sets show that the proposed algorithm obviously improves the efficiency of the traditional method, especially for large-scale data.

  8. Effect of mindfulness-based stress reduction on sleep quality

    DEFF Research Database (Denmark)

    Andersen, Signe; Würtzen, Hanne; Steding-Jessen, Marianne

    2013-01-01

    The prevalence of sleep disturbance is high among cancer patients, and the sleep problems tend to last for years after the end of treatment. As part of a large randomized controlled clinical trial (the MICA trial, NCT00990977) of the effect of mindfulness-based stress reduction (MBSR) on psycholo......The prevalence of sleep disturbance is high among cancer patients, and the sleep problems tend to last for years after the end of treatment. As part of a large randomized controlled clinical trial (the MICA trial, NCT00990977) of the effect of mindfulness-based stress reduction (MBSR......) on psychological and somatic symptoms among breast cancer patients, the aim of the current study was to evaluate the effect of MBSR on the secondary outcome, 'sleep quality'....

  9. Hybrid Metal/Electrolyte Monolithic Low Temperature SOFCs

    National Research Council Canada - National Science Library

    Cochran, Joe

    2004-01-01

    The program objective is to develop SOFCs, operating in the 500-700 degrees C range, based on Metal/Electrolyte square cell honeycomb formed by simultaneous powder extrusion of electrolyte and metal...

  10. Increasing the open-circuit voltage of photoprotein-based photoelectrochemical cells by manipulation of the vacuum potential of the electrolytes.

    Science.gov (United States)

    Tan, Swee Ching; Crouch, Lucy I; Mahajan, Sumeet; Jones, Michael R; Welland, Mark E

    2012-10-23

    The innately highly efficient light-powered separation of charge that underpins natural photosynthesis can be exploited for applications in photoelectrochemistry by coupling nanoscale protein photoreaction centers to man-made electrodes. Planar photoelectrochemical cells employing purple bacterial reaction centers have been constructed that produce a direct current under continuous illumination and an alternating current in response to discontinuous illumination. The present work explored the basis of the open-circuit voltage (V(OC)) produced by such cells with reaction center/antenna (RC-LH1) proteins as the photovoltaic component. It was established that an up to ~30-fold increase in V(OC) could be achieved by simple manipulation of the electrolyte connecting the protein to the counter electrode, with an approximately linear relationship being observed between the vacuum potential of the electrolyte and the resulting V(OC). We conclude that the V(OC) of such a cell is dependent on the potential difference between the electrolyte and the photo-oxidized bacteriochlorophylls in the reaction center. The steady-state short-circuit current (J(SC)) obtained under continuous illumination also varied with different electrolytes by a factor of ~6-fold. The findings demonstrate a simple way to boost the voltage output of such protein-based cells into the hundreds of millivolts range typical of dye-sensitized and polymer-blend solar cells, while maintaining or improving the J(SC). Possible strategies for further increasing the V(OC) of such protein-based photoelectrochemical cells through protein engineering are discussed.

  11. Fabrication of Cost-Effective Dye-Sensitized Solar Cells Using Sheet-Like CoS2 Films and Phthaloylchitosan-Based Gel-Polymer Electrolyte

    Directory of Open Access Journals (Sweden)

    Saradh Prasad

    2018-01-01

    Full Text Available Platinum-free counter electrodes (CE were developed for use in efficient and cost-effective energy conversion devices, such as dye-sensitized solar cells (DSSCs. Electrochemical deposition of CoS2 on fluorine-doped tin oxide (FTO formed a hierarchical sheet-like structured CoS2 thin film. This film was engaged as a cost-effective platinum-free and high-efficiency CE for DSSCs. High stability was achieved using a phthaloychitosan-based gel-polymer electrolyte as the redox electrolyte. The electrocatalytic performance of the sheet-like CoS2 film was analyzed by electrochemical impedance spectroscopy and cyclic voltammetry. The film displayed improved electrocatalytic behavior that can be credited to a low charge-transfer resistance at the CE/electrolyte boundary and improved exchange between triiodide and iodide ions. The fabricated DSSCs with a phthaloychitosan-based gel-polymer electrolyte and sheet-like CoS2 CE had a power conversion efficiency (PCE, η of 7.29% with a fill factor (FF of 0.64, Jsc of 17.51 mA/cm2, and a Voc of 0.65 V, which was analogous to that of Pt CE (η = 7.82%. The high PCE of the sheet-like CoS2 CE arises from the enhanced FF and Jsc, which can be attributed to the abundant active electrocatalytic sites and enhanced interfacial charge-transfer by the well-organized surface structure.

  12. Dictionary-based output-space dimensionality reduction

    OpenAIRE

    Strasser, Pablo; Wang, Jung; Armand, Stéphane; Kalousis, Alexandros

    2013-01-01

    In this paper we propose a method for output dimensionality reduction based on dictionary learning. Our final goal is the prediction of complete time series from standard input vectorial data. To do so we formulate a single learning problem which on the one hand learns a new representation of the output space, using dictionary learning, and reduces its dimension, while on the other hand learns to predict from the input data the new output representation, using standard multi-output regression...

  13. Electrochemical and Spectroelectrochemical Characterization of an Iridium-Based Molecular Catalyst for Water Splitting: Turnover Frequencies, Stability, and Electrolyte Effects

    NARCIS (Netherlands)

    Diaz-Morales, O.; Hersbach, T.J.P.; Hetterscheid, D.G.H.; Reek, J.N.H.; Koper, M.T.M.

    2014-01-01

    We present a systematic electrochemical and spectroelectrochemical study of the catalytic activity for water oxidation of an iridium-N-dimethylimidazolin-2-ylidene (Ir-NHC-Me-2) complex adsorbed on a polycrystalline gold electrode. The work aims to understand the effect of the electrolyte properties

  14. New type of gel polymer electrolytes based on selected methacrylates and their characteristics. Part II. fluorinated co-polymers

    Czech Academy of Sciences Publication Activity Database

    Michálek, Jiří; Abbrent, Sabina; Musil, M.; Kovářová, Jana; Hodan, Jiří; Dybal, Jiří

    2016-01-01

    Roč. 208, 1 August (2016), s. 211-224 ISSN 0013-4686 R&D Projects: GA ČR(CZ) GAP102/10/2091 Institutional support: RVO:61389013 Keywords : gel polymer electrolytes * thermal analysis * ionic conductivity Subject RIV: CG - Electrochemistry Impact factor: 4.798, year: 2016

  15. A quasi-solid-state rechargeable lithium-oxygen battery based on a gel polymer electrolyte with an ionic liquid.

    Science.gov (United States)

    Jung, Kyu-Nam; Lee, Ji-In; Jung, Jong-Hyuk; Shin, Kyung-Hee; Lee, Jong-Won

    2014-05-28

    A quasi-solid-state lithium-oxygen battery constructed using a gel polymer electrolyte with an ionic liquid is proposed. The battery architecture incorporates a design feature that can be easily scaled up in size for use in large systems. The feasibility study demonstrates that the battery operates successfully for repeated discharge-charge cycles.

  16. Standard practice for electrolytic extraction of phases from Ni and Ni-Fe base superalloys using a hydrochloric-methanol electrolyte

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1995-01-01

    1.1 This practice covers a procedure for the isolation of carbides, borides, TCP (topologically close-packed), and GCP (geometrically close-packed) phases (Note 1) in nickel and nickel-iron base gamma prime strengthened alloys. Contamination of the extracted residue by coarse matrix (gamma) or gamma prime particles, or both, reflects the condition of the alloy rather than the techniques mentioned in this procedure. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  17. The Role of MgCl 2 as a Lewis Base in ROMgCl-MgCl 2 Electrolytes for Magnesium-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Baofei [Joint Center for Energy Storage Research, Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont Illinois 60439 USA; Huang, Jinhua [Joint Center for Energy Storage Research, Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont Illinois 60439 USA; He, Meinan [Joint Center for Energy Storage Research, Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont Illinois 60439 USA; Brombosz, Scott M. [Materials Science Division, Argonne National Laboratory, Lemont Illinois 60439 USA; Vaughey, John T. [Joint Center for Energy Storage Research, Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont Illinois 60439 USA; Zhang, Lu [Joint Center for Energy Storage Research, Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont Illinois 60439 USA; Burrell, Anthony K. [Joint Center for Energy Storage Research, Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont Illinois 60439 USA; Zhang, Zhengcheng [Joint Center for Energy Storage Research, Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont Illinois 60439 USA; Liao, Chen [Joint Center for Energy Storage Research, Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont Illinois 60439 USA

    2016-02-04

    A series of strong Lewis acid-free alkoxide/siloxide-based Mg electrolytes were deliberately developed with remarkable oxidative stability up to 3.5 V (vs. Mg/Mg2+). Despite the perception of ROMgCl (R=alkyl, silyl) as a strong base, ROMgCl acts like Lewis acid, whereas the role of MgCl2 in was unambiguously demonstrated as a Lewis base through the identification of the key intermediate using single crystal X-ray crystallography. This Lewis-acid-free strategy should provide a prototype system for further investigation of Mg-ion batteries.

  18. Nanoporous polymer electrolyte

    Science.gov (United States)

    Elliott, Brian [Wheat Ridge, CO; Nguyen, Vinh [Wheat Ridge, CO

    2012-04-24

    A nanoporous polymer electrolyte and methods for making the polymer electrolyte are disclosed. The polymer electrolyte comprises a crosslinked self-assembly of a polymerizable salt surfactant, wherein the crosslinked self-assembly includes nanopores and wherein the crosslinked self-assembly has a conductivity of at least 1.0.times.10.sup.-6 S/cm at 25.degree. C. The method of making a polymer electrolyte comprises providing a polymerizable salt surfactant. The method further comprises crosslinking the polymerizable salt surfactant to form a nanoporous polymer electrolyte.

  19. Hydrogel membrane electrolyte for electrochemical capacitors

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 121; Issue 5. Hydrogel membrane electrolyte for electrochemical capacitors ... In the present study, the preparation and characterization of poly(vinyl alcohol)-based hydrogel membranes (PHMEs) as electrolytes for electrochemical capacitors have been reported.

  20. Iron-Based Electrodes Meet Water-Based Preparation, Fluorine-Free Electrolyte and Binder: A Chance for More Sustainable Lithium-Ion Batteries?

    Science.gov (United States)

    Valvo, Mario; Liivat, Anti; Eriksson, Henrik; Tai, Cheuk-Wai; Edström, Kristina

    2017-06-09

    Environmentally friendly and cost-effective Li-ion cells are fabricated with abundant, non-toxic LiFePO 4 cathodes and iron oxide anodes. A water-soluble alginate binder is used to coat both electrodes to reduce the environmental footprint. The critical reactivity of LiPF 6 -based electrolytes toward possible traces of H 2 O in water-processed electrodes is overcome by using a lithium bis(oxalato)borate (LiBOB) salt. The absence of fluorine in the electrolyte and binder is a cornerstone for improved cell chemistry and results in stable battery operation. A dedicated approach to exploit conversion-type anodes more effectively is also disclosed. The issue of large voltage hysteresis upon conversion/de-conversion is circumvented by operating iron oxide in a deeply lithiated Fe/Li 2 O form. Li-ion cells with energy efficiencies of up to 92 % are demonstrated if LiFePO 4 is cycled versus such anodes prepared through a pre-lithiation procedure. These cells show an average energy efficiency of approximately 90.66 % and a mean Coulombic efficiency of approximately 99.65 % over 320 cycles at current densities of 0.1, 0.2 and 0.3 mA cm -2 . They retain nearly 100 % of their initial discharge capacity and provide an unmatched operation potential of approximately 2.85 V for this combination of active materials. No occurrence of Li plating was detected in three-electrode cells at charging rates of approximately 5C. Excellent rate capabilities of up to approximately 30C are achieved thanks to the exploitation of size effects from the small Fe nanoparticles and their reactive boundaries. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  1. Investigation of electrolyte leaching in the performance degradation of phosphoric acid-doped polybenzimidazole membrane-based high temperature fuel cells

    Science.gov (United States)

    Jeong, Yeon Hun; Oh, Kyeongmin; Ahn, Sungha; Kim, Na Young; Byeon, Ayeong; Park, Hee-Young; Lee, So Young; Park, Hyun S.; Yoo, Sung Jong; Jang, Jong Hyun; Kim, Hyoung-Juhn; Ju, Hyunchul; Kim, Jin Young

    2017-09-01

    Precise monitoring of electrolyte leaching in high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) devices during lifetime tests is helpful in making a diagnosis of their quality changes and analyzing their electrochemical performance degradation. Here, we investigate electrolyte leaching in the performance degradation of phosphoric acid (PA)-doped polybenzimidazole (PBI) membrane-based HT-PEMFCs. We first perform quantitative analyses to measure PA leakage during cell operation by spectrophotometric means, and a higher PA leakage rate is detected when the current density is elevated in the cell. Second, long-term degradation tests under various current densities of the cells and electrochemical impedance spectroscopy (EIS) analysis are performed to examine the influence of PA loss on the membrane and electrodes during cell performance degradation. The combined results indicate that PA leakage affect cell performance durability, mostly due to an increase in charge transfer resistance and a decrease in the electrochemical surface area (ECSA) of the electrodes. Additionally, a three-dimensional (3-D) HT-PEMFC model is applied to a real-scale experimental cell, and is successfully validated against the polarization curves measured during various long-term experiments. The simulation results highlight that the PA loss from the cathode catalyst layer (CL) is a significant contributor to overall performance degradation.

  2. New Ether-functionalized Morpholinium- and Piperidinium-based Ionic Liquids as Electrolyte Components in Lithium and Lithium-Ion Batteries.

    Science.gov (United States)

    Navarra, Maria Assunta; Fujimura, Kanae; Sgambetterra, Mirko; Tsurumaki, Akiko; Panero, Stefania; Nakamura, Nobuhumi; Ohno, Hiroyuki; Scrosati, Bruno

    2017-06-09

    Here, two ionic liquids, N-ethoxyethyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide (M 1,2O2 TFSI) and N-ethoxyethyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide (P 1,2O2 TFSI) were synthesized and compared. Fundamental relevant properties, such as thermal and electrochemical stability, density, and ionic conductivity were analyzed to evaluate the effects caused by the presence of the ether bond in the side chain and/or in the organic cation ring. Upon lithium salt addition, two electrolytes suitable for lithium batteries applications were found. Higher conducting properties of the piperidinium-based electrolyte resulted in enhanced cycling performances when tested with LiFePO 4 (LFP) cathode in lithium cells. When mixing the P 1,2O2 TFSI/LiTFSI electrolyte with a tailored alkyl carbonate mixture, the cycling performance of both Li and Li-ion cells greatly improved, with prolonged cyclability delivering very stable capacity values, as high as the theoretical one in the case of Li/LFP cell configurations. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Noise Reduction in EIT Quantum Memories based Cs Atoms

    Science.gov (United States)

    Ma, Lijun; Slattery, Oliver; Tang, Xiao; quantum communication project Team

    Electromagnetically induced transparency (EIT) is a widely used approach for quantum memories. In an EIT-based quantum memory, a strong residual control beam comes out together with a read-out signal at single-photon level. The strong residual control beam becomes a main noise source in the system. Noise reduction becomes critical for the quantum memory because noise reduces the quantum information fidelity. For an operational EIT quantum memory, the strong residual power of the control beam must be greatly reduced. In an EIT quantum memory based on warm atoms, the signal and control beams propagate in the same direction, and with very small frequency difference, so noise reduction becomes a very challenging issue. To solve this problem, three types of filtration including a polarization filter, an F-P etalon filter and an optically pumped absorption atomic filter have been developed in our lab. The overall noise reduction reaches 125 dB, which satisfies the requirement of quantum memory applications. By using the developed filtration elements, our quantum memory successfully demonstrated storage and retrieval of quantum signals at a single photon level with high fidelity.

  4. Sound reduction by metamaterial-based acoustic enclosure

    Directory of Open Access Journals (Sweden)

    Shanshan Yao

    2014-12-01

    Full Text Available In many practical systems, acoustic radiation control on noise sources contained within a finite volume by an acoustic enclosure is of great importance, but difficult to be accomplished at low frequencies due to the enhanced acoustic-structure interaction. In this work, we propose to use acoustic metamaterials as the enclosure to efficiently reduce sound radiation at their negative-mass frequencies. Based on a circularly-shaped metamaterial model, sound radiation properties by either central or eccentric sources are analyzed by numerical simulations for structured metamaterials. The parametric analyses demonstrate that the barrier thickness, the cavity size, the source type, and the eccentricity of the source have a profound effect on the sound reduction. It is found that increasing the thickness of the metamaterial barrier is an efficient approach to achieve large sound reduction over the negative-mass frequencies. These results are helpful in designing highly efficient acoustic enclosures for blockage of sound in low frequencies.

  5. Electrochemical reduction approach-based 3D graphene/Ni(OH)2 electrode for high-performance supercapacitors

    International Nuclear Information System (INIS)

    Yan, Huijun; Bai, Jianwei; Wang, Bin; Yu, Lei; Zhao, Lin; Wang, Jun; Liu, Qi; Liu, Jingyuan; Li, Zhanshuang

    2015-01-01

    Highlights: • 3D graphene foam is synthesized by a simple electrochemical reduction method. • The 3D graphene/Ni(OH) 2 composite is used as a monolithic free-standing electrode material. • The 3D conductive graphene network improves the contact between electrode and electrolyte. • Compositing graphene with Ni(OH) 2 sheets take full advantage of the synergistic effects. • Results show that the as-synthesized products have good electrochemical property. - Abstract: Using a simple electrochemical reduction approach, we have produced three-dimensional (3D) graphene foam having high conductivity and well-defined macroporous structure. Through a hydrothermal process, Ni(OH) 2 sheets are grown in-situ onto the graphene surface. This monolithic 3D graphene/Ni(OH) 2 composite is used as the free-standing electrode for supercapacitor application; it shows a high specific capacitance of 183.1 F g −1 (based on the total mass of the electrode), along with excellent rate capability and cycle performance. The asymmetric supercapacitor based on the 3D graphene/Ni(OH) 2 as a positive electrode and active carbon (AC) as a negative electrode is also assembled and it exhibits a specific capacitance of 148.3 F g −1 at 0.56 A g −1 and a high energy density of 52.7 W h kg −1 at a power density of 444.4 W kg −1 . Moreover, 3D graphene/Ni(OH) 2 //AC has a good cycle stability (87.9% capacitance retention after 1000 cycles), making it promising as one of the most attractive candidates for electrochemical energy storage. This excellent electrochemical performance results from the multiplexed 3D graphene network facilitating electron transport; the interlaced Ni(OH) 2 sheets shorten ion diffusion paths and facilitate the rapid migration of electrolyte ions

  6. Semiconductor electrolyte photovoltaic energy converter

    Science.gov (United States)

    Anderson, W. W.; Anderson, L. B.

    1975-01-01

    Feasibility and practicality of a solar cell consisting of a semiconductor surface in contact with an electrolyte are evaluated. Basic components and processes are detailed for photovoltaic energy conversion at the surface of an n-type semiconductor in contact with an electrolyte which is oxidizing to conduction band electrons. Characteristics of single crystal CdS, GaAs, CdSe, CdTe and thin film CdS in contact with aqueous and methanol based electrolytes are studied and open circuit voltages are measured from Mott-Schottky plots and open circuit photo voltages. Quantum efficiencies for short circuit photo currents of a CdS crystal and a 20 micrometer film are shown together with electrical and photovoltaic properties. Highest photon irradiances are observed with the GaAs cell.

  7. Study of ageing mechanisms of organic electrolyte super-capacitors based on activated carbons; Recherche des causes du vieillissement de supercondensateurs a electrolyte organique a base de carbones actives

    Energy Technology Data Exchange (ETDEWEB)

    Azais, Ph.

    2003-11-15

    The energy which is stored in electrochemical capacitors is proportional to the square of voltage. Consequently, the most attractive super-capacitors are those which operate in organic electrolyte medium, with an electrolyte potential window which theoretically can easily reach more than 3 V. However, even using lower values of voltage, there is a remarkable fading of the electrochemical characteristics with operating time, that is mainly characterized by capacitance loss and resistance increase. On a commercial point of view, these capacitors must be improved in order to reach the expected criterion of long operating life. In the presented work, we will determine some reasons of super-capacitors ageing in organic electrolyte (1 M solution of Et{sub 4}N{sup +} BF{sub 4}{sup -} in acetonitrile) and we will propose a treatment of activated carbon which noticeably improves the performance. A prolonged charging of electrochemical capacitors at 2.5 V, so called floating, results in gases formation and to a noticeable mass uptake of the electrodes. XPS and NMR analysis performed on carefully washed electrodes demonstrated the existence of decomposition products from the electrolyte, which are trapped in the pores of the activated carbon. These products block the pores, limiting the ions access to the active surface that causes the decay of electrochemical performances. Electrolyte decomposition is especially very high when the electrodes are constituted of carbons with a rich surface functionality, i.e. surface oxygenated groups and free radicals. Therefore, activated carbons have been submitted to thermal treatment, both in nitrogen and hydrogen atmosphere, allowing the oxygenated surface functionality to be noticeably depressed. Super-capacitors built with the treated materials have been submitted to floating during more than 2000 hours. Extremely good electrochemical performance are preserved with the electrodes obtained from activated carbons treated under hydrogen

  8. Optimization of hybrid polymer electrolytes with the effect of lithium salt concentration in PEO/PVdF-HFP blends

    Energy Technology Data Exchange (ETDEWEB)

    Pradeepa, P.; Edwin raj, S.; Sowmya, G.; Kalaiselvimary, J.; Ramesh Prabhu, M., E-mail: mkram83@gmail.com

    2016-03-15

    Highlights: • Polymer blends based on PVdF-HFP/PEO were prepared for Li-ion battery applications. • Structural and electrochemical studies were carried out on prepared electrolytes. • The electrolytes can be used as electrolyte in the possible device fabrications. - Abstract: Poly(ethylene oxide) (PEO) 6.25 wt%/poly(vinylidene fluoride-co-hexafluoropropylene) [P(VdF-HFP)] 18.75 wt% blend based electrolyte films containing different concentrations (2–10) wt% of lithium salt were prepared. The miscibility studies have been performed by using X-ray diffraction and Fourier transform infrared spectroscopy. The role of interaction between polymer hosts on conductivity is discussed using the results of a.c. impedance studies. A room temperature conductivity of 2.3912 × 10{sup −4} S cm{sup −1} has been obtained for PEO (6.25)–PVdF-HFP (18.75)–LiClO{sub 4} (8)–PC (67) polymer complex. The temperature dependence of the conductivity of polymer electrolyte seems to obey VTF relation. Electrochemical stability (3.3 V) was observed in the prepared polymer electrolyte. Reduction process and oxidation process of the prepared electrolyte system have also been evaluated by means of cyclic voltammetry. Thermogravimetric analysis results indicate thermal stability of PEO/PVdF-HFP lithium salt complexes. Roughness parameter of the sample having maximum ionic conductivity was studied by AFM. The morphology of the polymer complex is investigated by using SEM.

  9. A Review on Current Status of Stability and Knowledge on Liquid Electrolyte-Based Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Frédéric Sauvage

    2014-01-01

    Full Text Available The purpose of this review is to gather the current background in materials development and provide the reader with an accurate image of today’s knowledge regarding the stability of dye-sensitized solar cells. This contribution highlights the literature from the 1970s to the present day on nanostructured TiO2, dye, Pt counter electrode, and liquid electrolyte for which this review is focused on.

  10. SVM-based glioma grading. Optimization by feature reduction analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zoellner, Frank G.; Schad, Lothar R. [University Medical Center Mannheim, Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine; Emblem, Kyrre E. [Massachusetts General Hospital, Charlestown, A.A. Martinos Center for Biomedical Imaging, Boston MA (United States). Dept. of Radiology; Harvard Medical School, Boston, MA (United States); Oslo Univ. Hospital (Norway). The Intervention Center

    2012-11-01

    We investigated the predictive power of feature reduction analysis approaches in support vector machine (SVM)-based classification of glioma grade. In 101 untreated glioma patients, three analytic approaches were evaluated to derive an optimal reduction in features; (i) Pearson's correlation coefficients (PCC), (ii) principal component analysis (PCA) and (iii) independent component analysis (ICA). Tumor grading was performed using a previously reported SVM approach including whole-tumor cerebral blood volume (CBV) histograms and patient age. Best classification accuracy was found using PCA at 85% (sensitivity = 89%, specificity = 84%) when reducing the feature vector from 101 (100-bins rCBV histogram + age) to 3 principal components. In comparison, classification accuracy by PCC was 82% (89%, 77%, 2 dimensions) and 79% by ICA (87%, 75%, 9 dimensions). For improved speed (up to 30%) and simplicity, feature reduction by all three methods provided similar classification accuracy to literature values ({proportional_to}87%) while reducing the number of features by up to 98%. (orig.)

  11. A Highly Flexible Supercapacitor Based on MnO2/RGO Nanosheets and Bacterial Cellulose-Filled Gel Electrolyte

    Directory of Open Access Journals (Sweden)

    Haojie Fei

    2017-10-01

    Full Text Available The flexible supercapacitors (SCs of the conventional sandwich-type structure have poor flexibility due to the large thickness of the final entire device. Herein, we have fabricated a highly flexible asymmetric SC using manganese dioxide (MnO2 and reduced graphene oxide (RGO nanosheet-piled hydrogel films and a novel bacterial cellulose (BC-filled polyacrylic acid sodium salt-Na2SO4 (BC/PAAS-Na2SO4 neutral gel electrolyte. Apart from being environmentally friendly, this BC/PAAS-Na2SO4 gel electrolyte has high viscosity and a sticky property, which enables it to combine two electrodes together. Meanwhile, the intertangling of the filled BC in the gel electrolyte hinders the decrease of the viscosity with temperature, and forms a separator to prevent the two electrodes from short-circuiting. Using these materials, the total thickness of the fabricated device does not exceed 120 μm. This SC device demonstrates high flexibility, where bending and even rolling have no obvious effect on the electrochemical performance. In addition, owing to the asymmetric configuration, the cell voltage of this flexible SC has been extended to 1.8 V, and the energy density can reach up to 11.7 Wh kg−1 at the power density of 441 W kg−1. This SC also exhibits a good cycling stability, with a capacitance retention of 85.5% over 5000 cycles.

  12. Interfacial reactions between graphite electrodes and propylene carbonate-based solutions: Electrolyte-concentration dependence of electrochemical lithium intercalation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Soon-Ki [Department of Chemical Engineering, Soonchunhyang University, Asan, Chungnam 336-745 (Korea); Inaba, Minoru [Department of Molecular Science and Technology, Faculty of Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan); Iriyama, Yasutoshi; Abe, Takeshi; Ogumi, Zempachi [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan)

    2008-01-03

    This study examines the electrochemical reactions occurring at graphite negative electrodes of lithium-ion batteries in a propylene carbonate (PC) electrolyte that contains different concentrations of lithium salts such as, LiClO{sub 4}, LiPF{sub 6} or LiN(SO{sub 2}C{sub 2}F{sub 5}){sub 2}. The electrode reactions are significantly affected by the electrolyte concentration. In concentrated solutions, lithium ions are reversibly intercalated within the graphite to form stage 1 lithium-graphite intercalation compounds (Li-GICs), regardless of the lithium salt used. On the other hand, electrolyte decomposition and exfoliation of the graphene layers occur continuously in the low-concentration range. In situ analysis with atomic force microscopy reveals that a thin film (thickness of {proportional_to}8 nm) forms on the graphite surface in a concentrated solution, e.g., 3.27 mol kg{sup -1} LiN(SO{sub 2}C{sub 2}F{sub 5}){sub 2}/PC, after the first potential cycle between 2.9 and 0 V versus Li{sup +}/Li. There is no evidence of the co-intercalation of solvent molecules in the concentrated solution. (author)

  13. Single-ion triblock copolymer electrolytes based on poly(ethylene oxide) and methacrylic sulfonamide blocks for lithium metal batteries

    Science.gov (United States)

    Porcarelli, Luca; Aboudzadeh, M. Ali; Rubatat, Laurent; Nair, Jijeesh R.; Shaplov, Alexander S.; Gerbaldi, Claudio; Mecerreyes, David

    2017-10-01

    Single-ion conducting polymer electrolytes represent the ideal solution to reduce concentration polarization in lithium metal batteries (LMBs). This paper reports on the synthesis and characterization of single-ion ABA triblock copolymer electrolytes comprising PEO and poly(lithium 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethylsulfonyl)imide) blocks, poly(LiMTFSI). Block copolymers are prepared by reversible addition-fragmentation chain transfer polymerization, showing low glass transition temperature (-55 to 7 °C) and degree of crystallinity (51-0%). Comparatively high values of ionic conductivity are obtained (up to ≈ 10-4 S cm-1 at 70 °C), combined with a lithium-ion transference number close to unity (tLi+ ≈ 0.91) and a 4 V electrochemical stability window. In addition to these promising features, solid polymer electrolytes are successfully tested in lithium metal cells at 70 °C providing long lifetime up to 300 cycles, and stable charge/discharge cycling at C/2 (≈100 mAh g-1).

  14. Gel electrolytes with I-/I3- redox mediator based on methylcellulose for dye-sensitized solar cells

    Science.gov (United States)

    Yusof, S. Z.; Woo, H. J.; Careem, M. A.; Arof, A. K.

    2018-05-01

    A new gel electrolyte comprising methylcellulose (MC), LiBOB and succinonitrile (SN) has been prepared with dimethyl sulfoxide (DMSO) as solvent. The electrolyte with composition 8.73 wt % MC-2.92 wt % LiBOB-1.01 wt % SN-87.34 wt % DMSO exhibits the highest conductivity of 1.18 mS cm-1 at 25 °C. On partially substituting LiBOB with TMAI, the sample designated as TMAI 95 has the highest conducting composition of 8.70 wt % MC-0.14 wt % LiBOB-1.01 wt % SN-2.77 wt % TMAI-0.35 wt % I2-87.03 wt % DMSO. The conductivity is 1.96 mS cm-1. This sample is used to fabricate a dye sensitized photovoltaic cell that converts photons to electricity at an efficiency of 3.46%. The conductivity of this sample has been enhanced to 3.08 mS cm-1 on addition of 1.0 wt % butyl-methyl immidazolium iodide (BMII) ionic liquid and the efficiency of the cell fabricated is 4.63%. Total replacement of LiBOB component in the electrolyte with the same amount of LiI results in a conductivity increase of ∼23.5% and the DSSC exhibits a 5.72% efficiency.

  15. Data base on nuclear power plant dose reduction research projects

    Energy Technology Data Exchange (ETDEWEB)

    Khan, T.A.; Baum, J.W.

    1986-10-01

    Staff at the ALARA Center of Brookhaven National Laboratory have established a data base of information about current research that is likely to result in lower radiation doses to workers. The data base, concerned primarily with nuclear power generation, is part of a project that the ALARA Center is carrying out for the Nuclear Regulatory Commission. This report describes its current status. A substantial amount of research on reducing occupational exposure is being done in the US and abroad. This research is beginning to have an impact on the collective dose expenditures at nuclear power plants. The collective radiation doses in Europe, Japan, and North America all show downward trends. A large part of the research in the US is either sponsored by the nuclear industry through joint industry organizations such as EPRI and ESEERCO or is done by individual corporations. There is also significant participation by smaller companies. The main emphasis of the research on dose reduction is on engineering approaches aimed at reducing radiation fields or keeping people out of high-exposure areas by using robotics. Effective ALARA programs are also underway at a large number of nuclear plants. Additional attention should be given to non-engineering approaches to dose reduction, which are potentially very useful and cost effective but require quantitative study and analysis based on data from nuclear power plants. 9 refs., 1 fig.

  16. Liquid Redox Electrolytes for Dye-Sensitized Solar Cells

    OpenAIRE

    Yu, Ze

    2012-01-01

    This thesis focuses on liquid redox electrolytes in dye-sensitized solar cells (DSCs). A liquid redox electrolyte, as one of the key constituents in DSCs, typically consists of a redox mediator, additives and a solvent. This thesis work concerns all these three aspects of liquid electrolytes, aiming through fundamental insights to enhance the photovoltaic performances of liquid DSCs. Initial attention has been paid to the iodine concentration effects in ionic liquid (IL)-based electrolytes. I...

  17. Pyrrolidinium FSI and TFSI-Based Polymerized Ionic Liquids as Electrolytes for High-Temperature Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Manfred Kerner

    2018-02-01

    Full Text Available Promising electrochemical and dynamical properties, as well as high thermal stability, have been the driving forces behind application of ionic liquids (ILs and polymerized ionic liquids (PILs as electrolytes for high-temperature lithium-ion batteries (HT-LIBs. Here, several ternary lithium-salt/IL/PIL electrolytes (PILel have been investigated for synergies of having both FSI and TFSI anions present, primarily in terms of physico-chemical properties, for unique application in HT-LIBs operating at 80 °C. All of the electrolytes tested have low Tg and are thermally stable ≥100 °C, and with TFSI as the exclusive anion the electrolytes (set A have higher thermal stabilities ≥125 °C. Ionic conductivities are in the range of 1 mS/cm at 100 °C and slightly higher for set A PILel, which, however, have lower oxidation stabilities than set B PILel with both FSI and TFSI anions present: 3.4–3.7 V vs. 4.2 V. The evolution of the interfacial resistance increases for all PILel during the first 40 h, but are much lower for set B PILel and generally decrease with increasing Li-salt content. The higher interfacial resistances only influence the cycling performance at high C-rates (1 C, where set B PILel with high Li-salt content performs better, while the discharge capacities at the 0.1 C rate are comparable. Long-term cycling at 0.5 C, however, shows stable discharge capacities for 100 cycles, with the exception of the set B PILel with high Li-salt content. Altogether, the presence of both FSI and TFSI anions in the PILel results in lower ionic conductivities and decreased thermal stabilities, but also higher oxidation stabilities and reduced interfacial resistances and, in total, result in an improved rate capability, but compromised long-term capacity retention. Overall, these electrolytes open for novel designs of HT-LIBs.

  18. Reduction of inequalities in health: assessing evidence-based tools

    Directory of Open Access Journals (Sweden)

    Shea Beverley

    2006-09-01

    Full Text Available Abstract Background The reduction of health inequalities is a focus of many national and international health organisations. The need for pragmatic evidence-based approaches has led to the development of a number of evidence-based equity initiatives. This paper describes a new program that focuses upon evidence- based tools, which are useful for policy initiatives that reduce inequities. Methods This paper is based on a presentation that was given at the "Regional Consultation on Policy Tools: Equity in Population Health Reports," held in Toronto, Canada in June 2002. Results Five assessment tools were presented. 1. A database of systematic reviews on the effects of educational, legal, social, and health interventions to reduce unfair inequalities is being established through the Cochrane and Campbell Collaborations. 2 Decision aids and shared decision making can be facilitated in disadvantaged groups by 'health coaches' to help people become better decision makers, negotiators, and navigators of the health system; a pilot study in Chile has provided proof of this concept. 3. The CIET Cycle: Combining adapted cluster survey techniques with qualitative methods, CIET's population based applications support evidence-based decision making at local and national levels. The CIET map generates maps directly from survey or routine institutional data, to be used as evidence-based decisions aids. Complex data can be displayed attractively, providing an important tool for studying and comparing health indicators among and between different populations. 4. The Ottawa Equity Gauge is applying the Global Equity Gauge Alliance framework to an industrialised country setting. 5 The Needs-Based Health Assessment Toolkit, established to assemble information on which clinical and health policy decisions can be based, is being expanded to ensure a focus on distribution and average health indicators. Conclusion Evidence-based planning tools have much to offer the

  19. Reduction of inequalities in health: assessing evidence-based tools

    Science.gov (United States)

    Tugwell, Peter; O'Connor, Annette; Andersson, Neil; Mhatre, Sharmila; Kristjansson, Elizabeth; Jacobsen, Mary Jane; Robinson, Vivian; Hatcher-Roberts, Jan; Shea, Beverley; Francis, Daniel; Beardmore, Jil; Wells, George A; Losos, Joe

    2006-01-01

    Background The reduction of health inequalities is a focus of many national and international health organisations. The need for pragmatic evidence-based approaches has led to the development of a number of evidence-based equity initiatives. This paper describes a new program that focuses upon evidence- based tools, which are useful for policy initiatives that reduce inequities. Methods This paper is based on a presentation that was given at the "Regional Consultation on Policy Tools: Equity in Population Health Reports," held in Toronto, Canada in June 2002. Results Five assessment tools were presented. 1. A database of systematic reviews on the effects of educational, legal, social, and health interventions to reduce unfair inequalities is being established through the Cochrane and Campbell Collaborations. 2 Decision aids and shared decision making can be facilitated in disadvantaged groups by 'health coaches' to help people become better decision makers, negotiators, and navigators of the health system; a pilot study in Chile has provided proof of this concept. 3. The CIET Cycle: Combining adapted cluster survey techniques with qualitative methods, CIET's population based applications support evidence-based decision making at local and national levels. The CIET map generates maps directly from survey or routine institutional data, to be used as evidence-based decisions aids. Complex data can be displayed attractively, providing an important tool for studying and comparing health indicators among and between different populations. 4. The Ottawa Equity Gauge is applying the Global Equity Gauge Alliance framework to an industrialised country setting. 5 The Needs-Based Health Assessment Toolkit, established to assemble information on which clinical and health policy decisions can be based, is being expanded to ensure a focus on distribution and average health indicators. Conclusion Evidence-based planning tools have much to offer the goal of equitable health

  20. Surface characterization and corrosion behavior of calcium phosphate-base composite layer on titanium and its alloys via plasma electrolytic oxidation: A review paper.

    Science.gov (United States)

    Rafieerad, A R; Ashra, M R; Mahmoodian, R; Bushroa, A R

    2015-12-01

    In recent years, calcium phosphate-base composites, such as hydroxyapatite (HA) and carbonate apatite (CA) have been considered desirable and biocompatible coating layers in clinical and biomedical applications such as implants because of the high resistance of the composites. This review focuses on the effects of voltage, time and electrolytes on a calcium phosphate-base composite layer in case of pure titanium and other biomedical grade titanium alloys via the plasma electrolytic oxidation (PEO) method. Remarkably, these parameters changed the structure, morphology, pH, thickness and crystallinity of the obtained coating for various engineering and biomedical applications. Hence, the structured layer caused improvement of the biocompatibility, corrosion resistance and assignment of extra benefits for Osseo integration. The fabricated layer with a thickness range of 10 to 20 μm was evaluated for physical, chemical, mechanical and tribological characteristics via XRD, FESEM, EDS, EIS and corrosion analysis respectively, to determine the effects of the applied parameters and various electrolytes on morphology and phase transition. Moreover, it was observed that during PEO, the concentration of calcium, phosphor and titanium shifts upward, which leads to an enhanced bioactivity by altering the thickness. The results confirm that the crystallinity, thickness and contents of composite layer can be changed by applying thermal treatments. The corrosion behavior was investigated via the potentiodynamic polarization test in a body-simulated environment. Here, the optimum corrosion resistance was obtained for the coating process condition at 500 V for 15 min in Ringer solution. This review has been summarized, aiming at the further development of PEO by producing more adequate titanium-base implants along with desired mechanical and biomedical features. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Data base on nuclear power plant dose reduction research projects

    Energy Technology Data Exchange (ETDEWEB)

    Khan, T.A.; Dionne, B.J.; Baum, J.W.

    1985-12-01

    This report contains project information on the research and development activities of the nuclear power industry in the area of dose reduction. It is based on a data base of information set up at the ALARA Center of Brookhaven National Laboratory. One purpose of this report is to draw attention to work in progress and to enable researchers and subscribers to obtain further information from the investigators and project managers. Information is provided on 180 projects, divided according to whether they are oriented to Engineering Research or to Health Physics Technology. The report contains indices on main category, project manager, principal investigator, sponsoring organization, contracting organization, and subject. This is an initial report. It is intended that periodic updates be issued whenever sufficient material has been accumulated.

  2. Kernel Based Nonlinear Dimensionality Reduction and Classification for Genomic Microarray

    Science.gov (United States)

    Li, Xuehua; Shu, Lan

    2008-01-01

    Genomic microarrays are powerful research tools in bioinformatics and modern medicinal research because they enable massively-parallel assays and simultaneous monitoring of thousands of gene expression of biological samples. However, a simple microarray experiment often leads to very high-dimensional data and a huge amount of information, the vast amount of data challenges researchers into extracting the important features and reducing the high dimensionality. In this paper, a nonlinear dimensionality reduction kernel method based locally linear embedding(LLE) is proposed, and fuzzy K-nearest neighbors algorithm which denoises datasets will be introduced as a replacement to the classical LLE's KNN algorithm. In addition, kernel method based support vector machine (SVM) will be used to classify genomic microarray data sets in this paper. We demonstrate the application of the techniques to two published DNA microarray data sets. The experimental results confirm the superiority and high success rates of the presented method. PMID:27879930

  3. Kernel Based Nonlinear Dimensionality Reduction and Classification for Genomic Microarray.

    Science.gov (United States)

    Li, Xuehua; Shu, Lan

    2008-07-15

    Genomic microarrays are powerful research tools in bioinformatics and modern medicinal research because they enable massively-parallel assays and simultaneous monitoring of thousands of gene expression of biological samples. However, a simple microarray experiment often leads to very high-dimensional data and a huge amount of information, the vast amount of data challenges researchers into extracting the important features and reducing the high dimensionality. In this paper, a nonlinear dimensionality reduction kernel method based locally linear embedding(LLE) is proposed, and fuzzy K-nearest neighbors algorithm which denoises datasets will be introduced as a replacement to the classical LLE's KNN algorithm. In addition, kernel method based support vector machine (SVM) will be used to classify genomic microarray data sets in this paper. We demonstrate the application of the techniques to two published DNA microarray data sets. The experimental results confirm the superiority and high success rates of the presented method.

  4. Ceramic electrolyte coating methods

    Energy Technology Data Exchange (ETDEWEB)

    Seabaugh, Matthew M.; Swartz, Scott L.; Dawson, William J.; McCormick, Buddy E.

    2004-10-12

    Processes for preparing aqueous suspensions of a nanoscale ceramic electrolyte material such as yttrium-stabilized zirconia. The invention also includes a process for preparing an aqueous coating slurry of a nanoscale ceramic electrolyte material. The invention further includes a process for depositing an aqueous spray coating slurry including a ceramic electrolyte material on pre-sintered, partially sintered, and unsintered ceramic substrates and products made by this process.

  5. Exploring single electrode reactions in polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, H.; Wokaun, A.; Scherer, G.G. [Paul Scherrer Institute, Electrochemistry Laboratory, 5232 Villigen (Switzerland)

    2007-01-20

    Utilising a pseudo-reference electrode in polymer electrolyte fuel cells allows for the separation of anodic and cathodic contributions to the entire cell impedance. Modelling the impedance responses by using equivalent circuits inhibits the investigation of kinetic parameters of the basic electrochemical reactions, which take place at single electrode-electrolyte interfaces. Therefore, we evaluate single electrode impedance measurements by a kinetic model, which is based on specific reaction pathways, either for the oxygen reduction reaction (ORR) or the hydrogen oxidation reaction (HOR). As a consequence, it is possible to obtain kinetic parameters for the specific reaction of interest. Furthermore, the information gained from the single electrode impedance measurements and the kinetic model can give insight into single reactions steps. In particular, the ORR has to include a chemical step in the reaction pathway. (author)

  6. Enhanced performance of P(VDF-HFP)-based composite polymer electrolytes doped with organic-inorganic hybrid particles PMMA-ZrO2 for lithium ion batteries

    Science.gov (United States)

    Xiao, Wei; Wang, Zhiyan; Zhang, Yan; Fang, Rui; Yuan, Zun; Miao, Chang; Yan, Xuemin; Jiang, Yu

    2018-04-01

    To improve the ionic conductivity as well as enhance the mechanical strength of the gel polymer electrolyte, poly(vinylidene fluoride-hexafluoroprolene) (P(VDF-HFP))-based composite polymer electrolyte (CPE) membranes doped with the organic-inorganic hybrid particles poly(methyl methacrylate) -ZrO2 (PMMA-ZrO2) are prepared by phase inversion method, in which PMMA is successfully grafted onto the surface of the homemade nano-ZrO2 particles via in situ polymerization confirmed by FT-IR. XRD and DSC patterns show adding PMMA-ZrO2 particles into P(VDF-HFP) can significantly decrease the crystallinity of the CPE membrane. The CPE membrane doped with 5 wt % PMMA-ZrO2 particles can not only present a homogeneous surface with abundant interconnected micro-pores, but maintain its initial shape after thermal exposure at 160 °C for 1 h, in which the ionic conductivity and lithium ion transference number at room temperature can reach to 3.59 × 10-3 S cm-1 and 0.41, respectively. The fitting results of the EIS plots indicate the doped PMMA-ZrO2 particles can significantly lower the interface resistance and promote lithium ions diffusion rate. The Li/CPE-sPZ/LiCoO2 and Li/CPE-sPZ/Graphite coin cells can deliver excellent rate and cycling performance. Those results suggest the P(VDF-HFP)-based CPE doped with 5 wt % PMMA-ZrO2 particles can become an exciting potential candidate as polymer electrolyte for the lithium ion battery.

  7. Object-based Dimensionality Reduction in Land Surface Phenology Classification

    Directory of Open Access Journals (Sweden)

    Brian E. Bunker

    2016-11-01

    Full Text Available Unsupervised classification or clustering of multi-decadal land surface phenology provides a spatio-temporal synopsis of natural and agricultural vegetation response to environmental variability and anthropogenic activities. Notwithstanding the detailed temporal information available in calibrated bi-monthly normalized difference vegetation index (NDVI and comparable time series, typical pre-classification workflows average a pixel’s bi-monthly index within the larger multi-decadal time series. While this process is one practical way to reduce the dimensionality of time series with many hundreds of image epochs, it effectively dampens temporal variation from both intra and inter-annual observations related to land surface phenology. Through a novel application of object-based segmentation aimed at spatial (not temporal dimensionality reduction, all 294 image epochs from a Moderate Resolution Imaging Spectroradiometer (MODIS bi-monthly NDVI time series covering the northern Fertile Crescent were retained (in homogenous landscape units as unsupervised classification inputs. Given the inherent challenges of in situ or manual image interpretation of land surface phenology classes, a cluster validation approach based on transformed divergence enabled comparison between traditional and novel techniques. Improved intra-annual contrast was clearly manifest in rain-fed agriculture and inter-annual trajectories showed increased cluster cohesion, reducing the overall number of classes identified in the Fertile Crescent study area from 24 to 10. Given careful segmentation parameters, this spatial dimensionality reduction technique augments the value of unsupervised learning to generate homogeneous land surface phenology units. By combining recent scalable computational approaches to image segmentation, future work can pursue new global land surface phenology products based on the high temporal resolution signatures of vegetation index time series.

  8. Ion conducting solid polymer electrolytes based on polypentafluorostyrene-b-polyether-b-polypentafluorostyrene prepared by atom transfer radical polymerization

    DEFF Research Database (Denmark)

    Jankova, Katja; Jannasch, P.; Hvilsted, Søren

    2004-01-01

    .3. The bromoisobutyrate functionalized polyether macroinitiators with molecular masses (M-n) of approx. 10 000 enabled the addition of between 15 and 39 wt.% flanking PFS as found by H-1 NMR. In a similar fashion monomethoxy PEG ( MPEG, Mn 5 000) was added 50 wt.% PFS. Polymer electrolytes were prepared by complexing...... blocks (T-g -65 degreesC) were immiscible and resulted in phase separation providing an elastomeric material in form of a physically cross-linked polyether network, even when the PFS block consisted of only about four monomer units. The salted triblock copolymers of PEGPG demonstrated conductivities...

  9. Fatigue strength reduction factors for welds based on nondestructive examination

    International Nuclear Information System (INIS)

    Hechmer, J.L.; Kuhn, E.J. III

    1999-01-01

    Based on the author's hypothesis that nondestructive examination (NDE) has a major role in predicting the fatigue life of pressure vessels, a project was initiated to develop a defined relationship between NDE and fatigue strength reduction factors (FSRF). Even though a relationship should apply to both base metal and weld metal, the project was limited to weld metal because NDE for base metal is reasonably well established, whereas NDE for weld metal is more variable, depending on application. A matrix of FSRF was developed based on weld type (full penetration, partial penetration, and fillet weld) versus the NDE that is applied. The NDE methods that are included are radiographic testing (RT), ultrasonic testing (UT), magnetic particle testing (MT), dye penetrant testing (PT), and visual testing (VT). The first two methods (RT and UT) are volumetric examinations, and the remaining three are surface examinations. Seven combinations of volumetric and surface examinations were defined; thus, seven levels of FSRF are defined. Following the initial development of the project, a PVRC (Pressure Vessel Research Council) grant was obtained for the purpose of having a broad review. The report (Hechmer, 1998) has been accepted by PVRC. This paper presents the final matrix, the basis for the FSRF, and key definitions for accurate application of the FSRF matrix. A substantial amount of additional information is presented in the PVRC report (Hechmer, 1998)

  10. Nonlinear Dimensionality Reduction via Path-Based Isometric Mapping.

    Science.gov (United States)

    Najafi, Amir; Joudaki, Amir; Fatemizadeh, Emad

    2016-07-01

    Nonlinear dimensionality reduction methods have demonstrated top-notch performance in many pattern recognition and image classification tasks. Despite their popularity, they suffer from highly expensive time and memory requirements, which render them inapplicable to large-scale datasets. To leverage such cases we propose a new method called "Path-Based Isomap". Similar to Isomap, we exploit geodesic paths to find the low-dimensional embedding. However, instead of preserving pairwise geodesic distances, the low-dimensional embedding is computed via a path-mapping algorithm. Due to the much fewer number of paths compared to number of data points, a significant improvement in time and memory complexity with a comparable performance is achieved. The method demonstrates state-of-the-art performance on well-known synthetic and real-world datasets, as well as in the presence of noise.

  11. Jet-noise reduction through liquid-base foam injection.

    Science.gov (United States)

    Manson, L.; Burge, H. L.

    1971-01-01

    An experimental investigation has been made of the sound-absorbing properties of liquid-base foams and of their ability to reduce jet noise. Protein, detergent, and polymer foaming agents were used in water solutions. A method of foam generation was developed to permit systematic variation of the foam density. The investigation included measurements of sound-absorption coefficents for both plane normal incidence waves and diffuse sound fields. The intrinsic acoustic properties of foam, e.g., the characteristic impedance and the propagation constant, were also determined. The sound emitted by a 1-in.-diam cold nitrogen jet was measured for subsonic (300 m/sec) and supersonic (422 m/sec) jets, with and without foam injection. Noise reductions up to 10 PNdB were measured.

  12. Ionic Borate-Based Covalent Organic Frameworks: Lightweight Porous Materials for Lithium-Stable Solid State Electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Black, Hayden T; Harrison, Katharine Lee

    2016-10-01

    The synthesis and characterization of the first polyelectrolyte of intrinsic microporosity (PEIM) is described. The novel material was synthesized via reaction between the nitrile group in the polymer backbone and n-butyl lithium, effectively anchoring an imine anion to the porous framework while introducing a mobile lithium counterion. The PEIM was characterized by 13C, 1H, and 7Li NMR experiments, revealing quantitative conversion of the nitrile functionality to the anionic imine. Variable temperature 7Li NMR analysis of the dry PEIM and the electrolyteswollen PEIM revealed that lithium ion transport within the dry PEIM was largely due to interchain hopping of the Li+ ions, and that the mobility of polymer associated Li+ was reduced after swelling in electrolyte solution. Meanwhile, the swollen PEIM supported efficient transport of dissolved Li+ within the expanded pores. These results are discussed in the context of developing novel solid or solid-like lithium ion electrolytes using the new PEIM material.

  13. Development of complex hydride-based all-solid-state lithium ion battery applying low melting point electrolyte

    Science.gov (United States)

    Suzuki, Shohei; Kawaji, Jun; Yoshida, Koji; Unemoto, Atsushi; Orimo, Shin-ichi

    2017-08-01

    A thermally durable all-solid-state lithium ion battery composed of a complex hydride, oxide electrolytes, and LiNi1/3Mn1/3Co1/3O2 active material is developed. This battery exhibits a discharge capacity of 56 mAh g-1, and the tenth capacity retention ratio is 29% at 150 °C owing to the large contact resistance between the electrolyte layer and the composite positive electrode layer. This large contact resistance is reduced by introducing an adhesive layer comprised of a mixture of LiBH4 and LiNH2 that is easily melted by thermal treatment and fills the voids and pores at the interface between the two layers. As a result, repeated charge-discharge cycles are successfully demonstrated at 150 °C with a high discharge capacity and discharge capacity retention ratio. The first discharge capacity is enhanced to 114 mAh g-1 and the capacity retention ratio at the tenth cycle is improved to 71%. These results demonstrate that using an adhesive layer is an effective measure to reduce the contact resistance and thereby enhance the performance of the battery.

  14. Interpolation-Based Condensation Model Reduction Part 1: Frequency Window Reduction Method Application to Structural Acoustics

    National Research Council Canada - National Science Library

    Ingel, R

    1999-01-01

    .... Projection operators are employed for the model reduction or condensation process. Interpolation is then introduced over a user defined frequency window, which can have real and imaginary boundaries and be quite large. Hermitian...

  15. Noise Reduction for a MEMS-Gyroscope-Based Head Mouse.

    Science.gov (United States)

    Du, Jiaying; Gerdtman, Christer; Lindén, Maria

    2015-01-01

    In this paper, four different signal processing algorithms which can be applied to reduce the noise from a MEMS-gyroscope-based computer head mouse are presented. MEMS-gyroscopes are small, light, cheap and widely used in many electrical products. MultiPos, a MEMS-gyroscope-based computer head mouse system was designed for persons with movement disorders. Noise such as physiological tremor and electrical noise is a common problem for the MultiPos system. In this study four different signal processing algorithms were applied and evaluated by simulation in MATLAB and implementation in a dsPIC, with aim to minimize the noise in MultiPos. The algorithms were low-pass filter, Least Mean Square (LMS) algorithm, Kalman filter and Weighted Fourier Linear Combiner (WFLC) algorithm. Comparisons and system tests show that these signal processing algorithms can be used to improve the MultiPos system. The WFLC algorithm was found the best method for noise reduction in the application of a MEMS-gyroscope-based head mouse.

  16. Electrochemical characterization of MnO2-based composite in the presence of salt-in-water and water-in-salt electrolytes as electrode for electrochemical capacitors

    Science.gov (United States)

    Gambou-Bosca, Axel; Bélanger, Daniel

    2016-09-01

    The effect of the electrolyte on the electrochemical utilization of manganese dioxide as active material for electrochemical capacitor was studied by cyclic voltammetry and electrochemical impedance spectroscopy. MnO2-based composite electrodes were characterized in salt-in-water (0.65 M K2SO4, 5 M LiNO3, 0.5 M LiNO3 and 0.5 M Ca(NO3)2) and water-in-salt (5 M LiTFSI (lithium bis-trifluoromethanesulfonimide)) electrolytes. Firstly, no effect of the cation valence on the specific capacitance was observed as similar values were measured in 0.5 M LiNO3 and 0.5 M Ca(NO3)2 aqueous solutions at both low and high scan rate, when a MnO2-based composite electrode was cycled in the pseudocapacitive potential region. Secondly, it was found that in 5 M LiTFSI, a MnO2 electrode is characterized by an extended potential stability window of about 1.4 V and exhibits a high specific capacitance of 239 F g-1 per active material mass at a scan rate of 2 mV s-1. However due to the low ionic conductivity of this solution, the rate capability is limited at high scan rate.

  17. Two-dimensional ion chromatography for the separation of ionic organophosphates generated in thermally decomposed lithium hexafluorophosphate-based lithium ion battery electrolytes.

    Science.gov (United States)

    Kraft, Vadim; Grützke, Martin; Weber, Waldemar; Menzel, Jennifer; Wiemers-Meyer, Simon; Winter, Martin; Nowak, Sascha

    2015-08-28

    A two-dimensional ion chromatography (IC/IC) technique with heart-cutting mode for the separation of ionic organophosphates was developed. These analytes are generated during thermal degradation of three different commercially available Selectilyte™ lithium ion battery electrolytes. The composition of the investigated electrolytes is based on 1M lithium hexafluorophosphate (LiPF6) dissolved in ethylene carbonate/dimethyl carbonate (50:50wt%, LP30), ethylene carbonate/diethyl carbonate (50:50wt%, LP40) and ethylene carbonate/ethyl methyl carbonate (50:50wt%, LP50). The organophosphates were pre-separated from PF6(-) anion on the low capacity A Supp 4 column, which was eluted with a gradient step containing acetonitrile. The fraction containing analytes was retarded on a pre-concentration column and after that transferred to the high capacity columns, where the separation was performed isocratically. Different stationary phases and eluents were applied on the 2nd dimension for the investigation of retention times, whereas the highly promising results were obtained with a high capacitive A Supp 10 column. The organophosphates generated in LP30 and LP40 electrolytes could be separated by application of an aqueous NaOH eluent providing fast analysis time within 35min. For the separation of the organophosphates of LP50 electrolyte due to its complexity a NaOH eluent containing a mixture of methanol/H2O was necessary. In addition, the developed two dimensional IC method was hyphenated to an inductively coupled plasma mass spectrometer (ICP-MS) using aqueous NaOH without organic modifiers. This proof of principle measurement was carried out for future quantitative investigation regarding the concentration of the ionic organophosphates. Furthermore, the chemical stability of several ionic organophosphates in water and acetonitrile at room temperature over a period of 10h was investigated. In both solvents no decomposition of the investigated analytes was observed and

  18. Towards Prognostics of Electrolytic Capacitors

    Data.gov (United States)

    National Aeronautics and Space Administration — A remaining useful life prediction algorithm and degradation model for electrolytic capacitors is presented. Electrolytic capacitors are used in several applications...

  19. Initial Electrospreading of Aqueous Electrolyte Drops

    Science.gov (United States)

    Chen, Longquan; Li, Chunli; van der Vegt, Nico F. A.; Auernhammer, Günter K.; Bonaccurso, Elmar

    2013-01-01

    The early spreading of a liquid drop on a solid surface driven by inertial, capillary, and electrostatic forces is of fundamental interest, since most commonly used surfaces are (naturally) charged. We studied the effect of applying an electric potential between a drop and a surface on the early spreading of aqueous electrolyte drops. We found that spreading dynamics not only depended on the potential, but also on the electrolyte concentration. Based on molecular dynamics simulations of the ion distribution in spreading nanodrops under an applied potential, we propose a simple model to explain the relation between applied potential, electrolyte concentration, and early spreading dynamics.

  20. Kernel Based Nonlinear Dimensionality Reduction and Classification for Genomic Microarray

    Directory of Open Access Journals (Sweden)

    Lan Shu

    2008-07-01

    Full Text Available Genomic microarrays are powerful research tools in bioinformatics and modern medicinal research because they enable massively-parallel assays and simultaneous monitoring of thousands of gene expression of biological samples. However, a simple microarray experiment often leads to very high-dimensional data and a huge amount of information, the vast amount of data challenges researchers into extracting the important features and reducing the high dimensionality. In this paper, a nonlinear dimensionality reduction kernel method based locally linear embedding(LLE is proposed, and fuzzy K-nearest neighbors algorithm which denoises datasets will be introduced as a replacement to the classical LLE’s KNN algorithm. In addition, kernel method based support vector machine (SVM will be used to classify genomic microarray data sets in this paper. We demonstrate the application of the techniques to two published DNA microarray data sets. The experimental results confirm the superiority and high success rates of the presented method.

  1. Identification of interactions using model-based multifactor dimensionality reduction.

    Science.gov (United States)

    Gola, Damian; König, Inke R

    2016-01-01

    Common complex traits may involve multiple genetic and environmental factors and their interactions. Many methods have been proposed to identify these interaction effects, among them several machine learning and data mining methods. These are attractive for identifying interactions because they do not rely on specific genetic model assumptions. To handle the computational burden arising from an exhaustive search, including all possible combinations of factors, filter methods try to select promising factors in advance. Model-based multifactor dimensionality reduction (MB-MDR), a semiparametric machine learning method allowing adjustment for confounding variables and lower level effects, is applied to Genetic Analysis Workshop 19 (GAW19) data to identify interaction effects on different traits. Several filtering methods based on the nearest neighbor algorithm are assessed in terms of compatibility with MB-MDR. Single nucleotide polymorphism (SNP) rs859400 shows a significant interaction effect (corrected p value <0.05) with age on systolic blood pressure (SBP). We identified 23 SNP-SNP interaction effects on hypertension status (HS), 42 interaction effects on SBP, and 26 interaction effects on diastolic blood pressure (DBP). Several of these SNPs are in strong linkage disequilibrium (LD). Three of the interaction effects on HS are identified in filtered subsets. The considered filtering methods seem not to be appropriate to use with MB-MDR. LD pruning is further quality control to be incorporated, which can reduce the combinatorial burden by removing redundant SNPs.

  2. Two-ply yarn supercapacitor based on carbon nanotube/stainless steel core-sheath yarn electrodes and ionic liquid electrolyte

    Science.gov (United States)

    Lyu, Xiaoming; Su, Fenghua; Miao, Menghe

    2016-03-01

    Linear supercapacitors have great potential as power source in electronic textiles. However, the energy density of most yarn supercapacitors reported so far is still quite low and decreases significantly as the supercapacitor length increases. Here, we report a two-ply yarn supercapacitor based on carbon nanotube/stainless steel core-sheath yarn electrode and ionic liquid electrolyte. The use of IL gel electrolyte widens the potential window of supercapacitor from 1.0 V to 2.7 V. The carbon nanotube/stainless steel core-sheath yarn structure greatly improves the charge transport efficiency and allows the length of the linear supercapacitor to be significantly scaled up. The resulting supercapacitor has shown outstanding electrochemical performances with a high volumetric capacitance of 263.31 F cm-3 and energy density of 6.67×10-2 Wh cm-3. The two-ply yarn supercapacitors are also very flexible and strong for use as sewing thread and for making knots without significant loss of their energy storage capacity.

  3. Effects of some rare earth and carbonate-based co-dopants on structural and electrical properties of samarium doped ceria (SDC) electrolytes for solid oxide fuel cells

    Science.gov (United States)

    Anwar, Mustafa; Khan, Zuhair S.; Mustafa, Kamal; Rana, Akmal

    2015-09-01

    In the present study, samarium doped ceria (SDC) and SDC-based composite with the addition of K2CO3 were prepared by co-precipitation route and effects of pH of the solution and calcination temperature on microstructure of SDC and SDC-K2CO3, respectively, were investigated. Furthermore, experimentation was performed to investigate into the ionic conductivity of pure SDC by co-doping with yttrium i.e., YSDC, XRD and SEM studies show that the crystallite size and particle size of SDC increases with the increase in pH. The SEM images of all the samples of SDC synthesized at different pH values showed the irregular shaped and dispersed particles. SDC-K2CO3 was calcined at 600∘C, 700∘C and 800∘C for 4 h and XRD results showed that crystallite size increases while lattice strain, decreases with the increase in calcination temperature and no peaks were detected for K2CO3 as it is present in an amorphous form. The ionic conductivity of the electrolytes increases with the increase in temperature and SDC-K2CO3 shows the highest value of ionic conductivity as compared to SDC and YSDC. Chemical compatibility tests were performed between the co-doped electrolyte and lithiated NiO cathode at high temperature. It revealed that the couple could be used up to the temperature of 700∘C.

  4. A novel temperature-gradient Na±β-alumina solid electrolyte based SOx gas sensor without gaseous reference electrode

    DEFF Research Database (Denmark)

    Rao, N.; Bleek, C.M. Van den; Schoonman, J.

    1992-01-01

    An electrochemical SOx ps sensor with a tubular Na+-beta"-alumina solid electrolyte has been fabricated and tested under non-isothermal conditions. The temperature difference between the reference and working electrode of the sensor cell is about 100-degrees-C, which causes a serious deviation...... of the experimental EMF response from the value as calculated using the Nernst equation for an isothermal system. The experimental results are Consistent with the theoretical prediction for a non-isothermal system. The response time is usually less then 10 min. SEM and EDX have been employed to investigate the sensor...... material before and after use, confirming the formation of a glassy phase of Na2SO4 by an electrochemical reaction at the interface of the platinum electrodes and Na+-beta"-alumina. According to this new theoretical derivation, the sensor design could be simplified by applying the same SO2 ps at the two...

  5. Enhanced conductivity of novel star branched liquid crystalline copolymer based on poly(ethylene oxide) for solid polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Tong Yongfen [Institute of Polymers/Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); School of Environmental and Chemical Engineering, Nanchang Hangkong University, 696 Fenghe South Avenue, Nanchang 330063 (China); Chen Lie, E-mail: chenlienc@163.com [Institute of Polymers/Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Chen Yiwang, E-mail: ywchen@ncu.edu.cn [Institute of Polymers/Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); He Xiaohui [Institute of Polymers/Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer Novel star branched amphiphilic liquid crystalline copolymers are prepared by atom-transfer radical polymerization. Black-Right-Pointing-Pointer Lamellar structures are achieved by cooperative assembly of hydrophobic mesogen-containing polymethacrylate and the amorphous hydrophilic TPEO nanoscale aggregation. Black-Right-Pointing-Pointer The ionic conductivity has been improved greatly by incorporation of the mesogens. - Abstract: Novel star branched amphiphilic liquid crystalline (LC) copolymers, namely, 4-Arm poly(ethylene oxide)-co-x-[(4-cyano-4 Prime -biphenyl)oxy]alkyl methacrylate (TPEO-MAxLC-{Phi}) (x = 6, {Phi} = 20, 30; x = 9, {Phi} = 10, 19) containing cyanobiphenyl mesogenic pendants (MAxLC) are prepared by atom-transfer radical polymerization (ATRP). The effects of structural variations on the properties, and the relationship between morphology and the ionic conductivity of the copolymer electrolytes are studied. The strong assembly of cyanobiphenyl mesogens induces the copolymers with enantiotropic mesophase, even after doped with LiClO{sub 4}. And lamellar structures are also achieved by cooperative assembly of hydrophobic mesogen-containing polymethacrylate groups and the hydrophilic TPEO nanoscale aggregation, especially after LC thermal annealing. The ionic conductivity has been improved greatly by incorporation of the cyanobiphenyl mesogens. This is because the mesogens not only favor the ordered morphology to provide the efficient ion transportation pathway, but also suppress TPEO crystallization to offer the movement of TPEO chains. Among all of the electrolyte films, TPEO-MA9LC-19 shows the best ion conductivity of 2.24 Multiplication-Sign 10{sup -5} S cm{sup -1} at 25 Degree-Sign C and even reaches to 5.39 Multiplication-Sign 10{sup -5} S cm{sup -1} after annealed at LC states.

  6. Highly efficient nonprecious metal catalysts towards oxygen reduction reaction based on three-dimensional porous carbon nanostructures.

    Science.gov (United States)

    Zhu, Chengzhou; Li, He; Fu, Shaofang; Du, Dan; Lin, Yuehe

    2016-02-07

    Developing a low cost, highly active, durable cathode towards an oxygen reduction reaction (ORR) is one of the high-priority research directions for commercialization of low-temperature polymer electrolyte membrane fuel cells (PEMFCs). However, the electrochemical performance of PEMFCs is still hindered by the high cost and insufficient durability of the traditional Pt-based cathode catalysts. Under these circumstances, the search for efficient alternatives to replace Pt for constructing highly efficient nonprecious metal catalysts (NPMCs) has been growing intensively and has received great interest. Combining with the compositional effects, the accurate design of NPMCs with 3D porous nanostructures plays a significant role in further enhancing ORR performance. These 3D porous architectures are able to provide higher specific surface areas and larger pore volumes, not only maximizing the availability of electron transfer within the nanosized electrocatalyst surface area but also providing better mass transport of reactants to the electrocatalyst. In this Tutorial Review, we focus on the rational design and synthesis of different 3D porous carbon-based nanomaterials, such as heteroatom-doped carbon, metal-nitrogen-carbon nanostructures and a series of carbon/nonprecious metal-based hybrids. More importantly, their enhanced ORR performances are also demonstrated by virtue of their favorably porous morphologies and compositional effects. Finally, the future trends and perspectives for the highly efficient porous NPMCs regarding the material design are discussed, with an emphasis on substantial development of advanced carbon-based NPMCs for ORR in the near future.

  7. In situ electrochemical-mass spectroscopic investigation of solid electrolyte interphase formation on the surface of a carbon electrode

    International Nuclear Information System (INIS)

    Gourdin, Gerald; Zheng, Dong; Smith, Patricia H.; Qu, Deyang

    2013-01-01

    The energy density of an electrochemical capacitor can be significantly improved by utilizing a lithiated negative electrode and a high surface area positive electrode. During lithiation of the negative carbon electrode, the electrolyte reacts with the electrode surface and undergoes decomposition to form a solid electrolyte interphase (SEI) layer that passivates the surface of the carbon electrode from further reactions between Li and the electrolyte. The reduction reactions that the solvent undergoes also form insoluble and gaseous by-products. In this work, those gaseous by-products generated by reductive decomposition of a carbonate-based electrolyte, 1.2 M LiPF 6 in EC/PC/DEC (3:1:4), were analyzed at different stages during the lithiation process of an amorphous carbon electrode. The stages in the generation of gaseous by-products were determined to come as a result of two, 1-electron reduction steps of the cyclic carbonate components of the electrolyte. Electrochemical impedance spectroscopy was also used to investigate the two distinct electrochemical processes and the development of the two phases of the SEI structure. This is the first time that the state of an electrochemical cell during the formation of the SEI layer has been systematically correlated with theoretical reaction mechanisms through the use of in situ electrochemical-MS and impedance spectroscopy analyses

  8. Ion Movement in Polypyrrole/Dodecylbenzenesulphonate Films in aqueous and non-aqueous electrolytes

    DEFF Research Database (Denmark)

    Vidanapathirana, K.; Careem, M.A.; Skaarup, Steen

    2002-01-01

    . Investigations were carried out using aqueous and non-aqueous electrolytes to study the effect of solvent on the ion movement during redox processes. When PPy films are cycled in aqueous electrolytes transport of both anion and cation occurs during oxidation and reduction. However, when cycled in the nonaqueous...... electrolyte propylene carbonate (PC) only anion movement takes place....

  9. Microbial electrolytic disinfection process for highly efficient Escherichia coli inactivation

    DEFF Research Database (Denmark)

    Zhou, Shaofeng; Huang, Shaobin; Li, Xiaohu

    2018-01-01

    extensively studied for recalcitrant organics removal, its application potential towards water disinfection (e.g., inactivation of pathogens) is still unknown. This study investigated the inactivation of Escherichia coli in a microbial electrolysis cell based bio-electro-Fenton system (renamed as microbial...... electrolytic-Fenton cell) with the aim to broad the application of microbial electrochemistry. Results showed that a 4-log reduction of Escherichia coli (107 to hundreds CFU/mL) was achieved with an external applied voltage of 0.2 V, 0.3 mM Fe2+ and cathodic pH of 3.0. However, non-notable inactivation...

  10. Laser speckle reduction based on compressive sensing and edge detection

    Science.gov (United States)

    Wen, Dong-hai; Jiang, Yue-song; Hua, Hou-qiang; Yu, Rong; Gao, Qian; Zhang, Yan-zhong

    2013-09-01

    Polarization active imager technology obtains images encoded by parameters different than just the reflectivity and therefore provides new information on the image. So polarization active imager systems represent a very powerful observation tool. However, automatic interpretation of the information contained in the reflected intensity of the polarization active image data is extremely difficult because of the speckle phenomenon. An approach for speckle reduction of polarization active image based on the concepts of compressive sensing (CS) theory and edge detection. First, A Canny operator is first utilized to detect and remove edges from the polarization active image. Then, a dictionary learning algorithm which is applied to sparse image representation. The dictionary learning problem is expressed as a box-constrained quadratic program and a fast projected gradient method is introduced to solve it. The Gradient Projection for Square Reconstruction (GPSR) algorithm for solving bound constrained quadratic programming to reduce the speckle noise in the polarization active images. The block-matching 3-D (BM3D) algorithm is used to reduce speckle nosie, it works in two steps: The first one uses hard thresholding to build a relatively clean image for estimating statistics, while the second one performs the actual denoising through empirical Wiener filtering in the transform domain. Finally, the removed edges are added to the reconstructed image. Experimental results show that the visual quality and evaluation indexes outperform the other methods with no edge preservation. The proposed algorithm effectively realizes both despeckling and edge preservation and reaches the state-of-the-art performance.

  11. A pilot study on mindfulness based stress reduction for smokers

    Directory of Open Access Journals (Sweden)

    Baker Timothy B

    2007-01-01

    Full Text Available Abstract Background Mindfulness means paying attention in the present moment, non-judgmentally, without commentary or decision-making. We report results of a pilot study designed to test the feasibility of using Mindfulness Based Stress Reduction (MBSR (with minor modifications as a smoking intervention. Methods MBSR instructors provided instructions in mindfulness in eight weekly group sessions. Subjects attempted smoking cessation during week seven without pharmacotherapy. Smoking abstinence was tested six weeks after the smoking quit day with carbon monoxide breath test and 7-day smoking calendars. Questionnaires were administered to evaluate changes in stress and affective distress. Results 18 subjects enrolled in the intervention with an average smoking history of 19.9 cigarettes per day for 26.4 years. At the 6-week post-quit visit, 10 of 18 subjects (56% achieved biologically confirmed 7-day point-prevalent smoking abstinence. Compliance with meditation was positively associated with smoking abstinence and decreases in stress and affective distress. Discussions and conclusion The results of this study suggest that mindfulness training may show promise for smoking cessation and warrants additional study in a larger comparative trial.

  12. The potential role of electrolytic hydrogen in Canada

    International Nuclear Information System (INIS)

    Hammerli, M.

    1982-03-01

    The potential role of electrolytic hydrogen in Canada is assessed for the period 1980 to 2025 for large-scale uses only. Present uses of hydrogen, and specifically electrolytic hydrogen, are discussed briefly and hydrogen production processes are summarized. Only hydrogen derived from natural gas, coal, or electrolysis of sater are considered. Cost estimates of electrolytic hydrogen are obtained from a parametric equation, comparing values for unipolar water elecctrklyser technologies with those for bipolar electrolysers. Both by-products of electrolytic hydrogen production, namely heavy water and oxygen, are evaluated. Electrolytic hydrogen, based on non-fossil primary energy sources, is also considered as ankther 'liquid fuel option' for Canada along with the alcohols. The market potential for hydrogen in general and electrolytic hydrogen is assessed. Results show that the market potential for electrolytic hydrogen is large by the year 2025

  13. Apparatus and method for the electrolytic production of metals

    Science.gov (United States)

    Sadoway, Donald R.

    1991-01-01

    Improved electrolytic cells and methods for producing metals by electrolytic reduction of a compound dissolved in a molten electrolyte are disclosed. In the improved cells and methods, a protective surface layer is formed upon at least one electrode in the electrolytic reduction cell and, optionally, upon the lining of the cell. This protective surface layer comprises a material that, at the operating conditions of the cell: (a) is not substantially reduced by the metal product; (b) is not substantially reactive with the cell electrolyte to form materials that are reactive with the metal product; and, (c) has an electrochemical potential that is more electronegative than that of the compound undergoing electrolysis to produce the metal product of the cell. The protective surface layer can be formed upon an electrode metal layer comprising a material, the oxide of which also satisfies the protective layer selection criteria. The protective layer material can also be used on the surface of a cell lining.

  14. Radar-Based Depth Area Reduction Factors for Colorado

    Science.gov (United States)

    Curtis, D. C.; Humphrey, J. H.; Bare, D.

    2011-12-01

    More than 340,000 fifteen-minute storm cells, nearly 45,000 one-hour cells, and over 20,000 three-hour cells found in 21 months of gage adjusted radar-rainfall estimates (GARR) over El Paso County, CO, were identified and evaluated using TITAN (Thunderstorm Identification, Tracking, Analysis and Nowcasting) software. TITAN's storm cell identification capability enabled the analysis of the geometric properties of storms, time step by time step. The gage-adjusted radar-rainfall data set was derived for months containing runoff producing events observed in the Fountain Creek Watershed within El Paso County from 1994-2008. Storm centered Depth Area Reduction Factors (DARFs) were computed and compared to DARFs published by the U.S. National Weather Service (NWS) in Technical Paper 29, which are widely used in stormwater infrastructure design. Radar-based storm centered DARFs decay much more sharply than the NWS standard curves. The results suggest lower watershed average rainfall inputs from radar-based storm centered DARFs than from standard NWS DARFs for a given watershed area. The results also suggest that DARFs are variable by return period and, perhaps, by location. Both findings could have significant impacts on design storm standards. Lower design volumes for a given return period translate to lower capacity requirements and lower cost infrastructure. Conversely, the higher volume requirements implied for the NWS DARFs translate to higher capacity requirements, higher costs, but lower risk of failure. Ultimately, a decision about which approach is to use depends on the risk tolerance of the decision maker. However, the growing volume of historical radar rainfall estimates coupled with the type of analysis described herein, supports a better understanding of risk and more informed decision-making by local officials.

  15. Electrolytic polishing system for space age materials

    International Nuclear Information System (INIS)

    Coons, W.C.; Iosty, L.R.

    1976-01-01

    A simple electrolytic polishing technique was developed for preparing Cr, Co, Hf, Mo, Ni, Re, Ti, V, Zr, and their alloys for structural analysis on the optical microscope. The base electrolyte contains 5g ZnCl 2 and 15g AlCl 3 . 6H 2 O in 200 ml methyl alcohol, plus an amount of H 2 SO 4 depending on the metal being polished. Five etchants are listed

  16. Electrolyte Disorders as Triggers for Takotsubo Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Fabio Andreozzi

    2018-02-01

    Full Text Available A 56-year-old woman presented with cognitive impairment, confusion and slowed speech, muscle cramps and peripheral paraesthesia preceded by vomiting. Blood tests revealed severe hypokalaemia, hyponatremia, hypomagnesemia and hypocalcaemia. Following a diagnosis of Takotsubo cardiomyopathy based on ultrasonography, the patient was treated with electrolyte supplementation and recovered within 48h. When heart failure is suspected, electrolyte abnormalities should be carefully ruled out as they can affect cardiac function.

  17. Eosin Yellowish Dye-Sensitized ZnO Nanostructure-Based Solar Cells Employing Solid PEO Redox Couple Electrolyte

    Directory of Open Access Journals (Sweden)

    S. S. Kanmani

    2012-01-01

    Full Text Available ZnO nanostructures are synthesized by low-temperature methods, and they possess polycrystalline hexagonal wurtzite structure with preferential c-axial growth. Morphological study by SEM shows the presence of ~30 nm sized spherical-shaped ZnO nanoparticle, the branched flower-like ZnO composed of many nanorods (length: 1.2 to 4.2 μm and diameter: 0.3 to 0.4 μm, and ~50 nm diameter of individual ZnO nanorods. Reduction in photoemission intensity of nanorods infers the decrease in electron-hole recombination rate, which offers better photovoltaic performance. The dye-sensitized solar cell (DSSC based on ZnO nanorods sensitized with Eosin yellowish dye exhibits a maximum optimal energy conversion efficiency of 0.163% compared to that of nanoparticles and nanoflowers, due to better dye loading and direct conduction pathway for electron transport.

  18. Plasma electrolytic oxidation of AMCs

    Science.gov (United States)

    Morgenstern, R.; Sieber, M.; Lampke, T.

    2016-03-01

    Aluminum Matrix Composites (AMCs) consisting of high-strength alloys and ceramic reinforcement phases exhibit a high potential for security relevant lightweight components due to their high specific mechanical properties. However, their application as tribologically stressed components is limited because of their susceptibility against fatigue wear and delamination wear. Oxide ceramic protective coatings produced by plasma electrolytic oxidation (PEO) can solve these problems and extend the possible applications of AMCs. The substrate material was powder metallurgically processed using alloy EN AW 2017 and SiC or Al2O3 particles. The influence of material properties like particle type, size and volume fraction on coating characteristics is clarified within this work. An alkaline silicate electrolyte was used to produce PEO coatings with technically relevant thicknesses under bipolar-pulsed current conditions. Coating properties were evaluated with regard to morphology, chemical composition, hardness and wear resistance. The particle type proved to have the most significant effect on the coating properties. Whereas compactness and thickness are not deteriorated by the incorporation of thermodynamically stable alumina particles, the decomposition of silica particles during the PEO processes causes an increase of the porosity. The higher silica particle content decreases also the coating thickness and hardness, which leads in particular to reduction of the wear resistance of the PEO coatings. Finally, different approaches for the reduction of the coating porosity of silica reinforced AMCs are discussed.

  19. Nanoscale Organic Hybrid Electrolytes

    KAUST Repository

    Nugent, Jennifer L.

    2010-08-20

    Nanoscale organic hybrid electrolytes are composed of organic-inorganic hybrid nanostructures, each with a metal oxide or metallic nanoparticle core densely grafted with an ion-conducting polyethylene glycol corona - doped with lithium salt. These materials form novel solvent-free hybrid electrolytes that are particle-rich, soft glasses at room temperature; yet manifest high ionic conductivity and good electrochemical stability above 5V. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Novel Nonflammable Electrolytes for Secondary Magnesium Batteries and High Voltage Electrolytes for Electrochemcial Supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Brian

    2008-12-30

    Magnesium has been used successfully in primary batteries, but its use in rechargeable cells has been stymied by the lack of suitable non-aqueous electrolyte that can conduct Mg+2 species, combined with poor stripping and plating properties. The development of a suitable cathode material for rechargeable magnesium batteries has also been a roadblock, but a nonflammable electrolyte is key. Likewise, the development of safe high voltage electrochemical supercapaitors has been stymied by the use of flammable solvents in the liquid electrolyte; to wit, acetonitrile. The purpose of the research conducted in this effort was to identify useful compositions of magnesium salts and polyphosphate solvents that would enable magnesium ions to be cycled within a secondary battery design. The polyphosphate solvents would provide the solvent for the magnesium salts while preventing the electrolyte from being flammable. This would enable these novel electrolytes to be considered as an alternative to THF-based electrolytes. In addition, we explored several of these solvents together with lithium slats for use as high voltage electrolytes for carbon-based electrochemical supercapacitors. The research was successful in that: 1) Magnesium imide dissolved in a phosphate ester solvent that contains a halogented phosphate ester appears to be the preferred electrolyte for a rechargeable Mg cell. 2) A combination of B-doped CNTs and vanadium phosphate appear to be the cathode of choice for a rechargeable Mg cell by virtue of higher voltage and better reversibility. 3) Magnesium alloys appear to perform better than pure magnesium when used in combination with the novel polyphosphate electrolytes. Also, this effort has established that Phoenix Innovation's family of phosphonate/phosphate electrolytes together with specific lithium slats can be used in supercapacitor systems at voltages of greater than 10V.

  1. Study on Stability and Electrochemical Properties of Nano-LiMn1.9Ni0.1O3.99S0.01-Based Li-Ion Batteries with Liquid Electrolyte Containing LiPF6

    Directory of Open Access Journals (Sweden)

    Monika Bakierska

    2016-01-01

    Full Text Available Herein, we report on the stability and electrochemical properties of nanosized Ni and S doped lithium manganese oxide spinel (LiMn1.9Ni0.1O3.99S0.01, LMN1OS in relation to the most commonly used electrolyte solution containing LiPF6 salt. The influence of electrochemical reaction in the presence of selected electrolyte on the LMN1OS electrode chemistry was examined. The changes in the structure, surface morphology, and composition of the LMN1OS cathode after 30 cycles of galvanostatic charging/discharging were determined. In addition, thermal stability and reactivity of the LMN1OS material towards the electrolyte system were verified. Performed studies revealed that no degradative effects, resulting from the interaction between the spinel electrode and liquid electrolyte, occur during electrochemical cycling. The LMN1OS electrode versus LiPF6-based electrolyte has been indicated as an efficient and electrochemically stable system, exhibiting high capacity, good rate capability, and excellent coulombic efficiency. The improved stability and electrochemical performance of the LMN1OS cathode material originate from the synergetic substitution of LiMn2O4 spinel with Ni and S.

  2. Novel binary deep eutectic electrolytes for rechargeable Li-ion batteries based on mixtures of alkyl sulfonamides and lithium perfluoroalkylsulfonimide salts

    Science.gov (United States)

    Geiculescu, O. E.; DesMarteau, D. D.; Creager, S. E.; Haik, O.; Hirshberg, D.; Shilina, Y.; Zinigrad, E.; Levi, M. D.; Aurbach, D.; Halalay, I. C.

    2016-03-01

    Ionic liquids (IL's) were proposed for use in Li-ion batteries (LIBs), in order to mitigate some of the well-known drawbacks of LiPF6/mixed organic carbonates solutions. However, their large cations seriously decrease lithium transference numbers and block lithium insertion sites at electrode-electrolyte interfaces, leading to poor LIB rate performance. Deep eutectic electrolytes (DEEs) (which share some of the advantages of ILs but possess only one cation, Li+), were then proposed, in order to overcome the difficulties associated with ILs. We report herein on the preparation, thermal properties (melting, crystallization, and glass transition temperatures), transport properties (specific conductivity and viscosity) and thermal stability of binary DEEs based on mixtures of lithium bis(trifluoromethane)sulfonimide or lithium bis(fluoro)sulfonimide salts with an alkyl sulfonamide solvent. Promise for LIB applications is demonstrated by chronoamperometry on Al current collectors, and cycling behavior of negative and positive electrodes. Residual current densities of 12 and 45 nA cm-2 were observed at 5 V vs. Li/Li+ on aluminum, 1.5 and 16 nA cm-2 at 4.5 V vs. Li/Li+, respectively for LiFSI and LiTFSI based DEEs. Capacities of 220, 130, and 175 mAh· g-1 were observed at low (C/13 or C/10) rates, respectively for petroleum coke, LiMn1/3Ni1/3Co1/3O2 (a.k.a. NMC 111) and LiAl0.05Co0.15Ni0.8O2 (a.k.a. NCA).

  3. Multifunctional Carbon-Based Metal-Free Electrocatalysts for Simultaneous Oxygen Reduction, Oxygen Evolution, and Hydrogen Evolution.

    Science.gov (United States)

    Hu, Chuangang; Dai, Liming

    2017-03-01

    Rationally designed N, S co-doped graphitic sheets with stereoscopic holes (SHG) act as effective tri-functional catalysts for the oxygen reduction reaction, hydrogen evolution reaction, and oxygen evolution reaction, simultaneously. The multifunctional electrocatalytic activities originate from a synergistic effect of the N, S heteroatom doping and unique SHG architecture, which provide a large surface area and efficient pathways for electron and electrolyte/reactant transports. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Shape based automated detection of pulmonary nodules with surface feature based false positive reduction

    International Nuclear Information System (INIS)

    Nomura, Y.; Itoh, H.; Masutani, Y.; Ohtomo, K.; Maeda, E.; Yoshikawa, T.; Hayashi, N.

    2007-01-01

    We proposed a shape based automated detection of pulmonary nodules with surface feature based false positive (FP) reduction. In the proposed system, the FP existing in internal of vessel bifurcation is removed using extracted surface of vessels and nodules. From the validation with 16 chest CT scans, we find that the proposed CAD system achieves 18.7 FPs/scan at 90% sensitivity, and 7.8 FPs/scan at 80% sensitivity. (orig.)

  5. Shear Thickening Electrolyte Built from Sterically Stabilized Colloidal Particles.

    Science.gov (United States)

    Shen, Brian H; Armstrong, Beth L; Doucet, Mathieu; Heroux, Luke; Browning, James F; Agamalian, Michael; Tenhaeff, Wyatt E; Veith, Gabriel M

    2018-03-21

    We present a method to prepare shear thickening electrolytes consisting of silica nanoparticles in conventional liquid electrolytes with limited flocculation. These electrolytes rapidly and reversibly stiffen to solidlike behaviors in the presence of external shear or high impact, which is promising for improved lithium ion battery safety, especially in electric vehicles. However, in initial chemistries the silica nanoparticles aggregate and/or sediment in solution over time. Here, we demonstrate steric stabilization of silica colloids in conventional liquid electrolyte via surface-tethered PMMA brushes, synthesized via surface-initiated atom transfer radical polymerization. The PMMA increases the magnitude of the shear thickening response, compared to the uncoated particles, from 0.311 to 2.25 Pa s. Ultrasmall-angle neutron scattering revealed a reduction in aggregation of PMMA-coated silica nanoparticles compared to bare silica nanoparticles in solution under shear and at rest, suggesting good stabilization. Conductivity tests of shear thickening electrolytes (30 wt % solids in electrolyte) at rest were performed with interdigitated electrodes positioned near the meniscus of electrolytes over the course of 24 h to track supernatant formation. Conductivity of electrolytes with bare silica increased from 10.1 to 11.6 mS cm -1 over 24 h due to flocculation. In contrast, conductivity of electrolytes with PMMA-coated silica remained stable at 6.1 mS cm -1 over the same time period, suggesting good colloid stability.

  6. Resolvent-based feedback control for turbulent friction drag reduction

    Science.gov (United States)

    Kawagoe, Aika; Nakashima, Satoshi; Luhar, Mitul; Fukagata, Koji

    2017-11-01

    Suboptimal control for turbulent friction drag reduction has been studied extensively. Nakashima et al. (accepted) extended resolvent analysis to suboptimal control, and for the control where the streamwise wall shear stress is used as an input (Case ST), they revealed the control effect across spectral space is mixed: there are regions of drag increase as well as reduction. This suggests that control performance may be improved if the control is applied for selective wavelengths, or if a new law is designed to suppress the spectral region leading to drag increase. In the present study, we first assess the effect of suboptimal control for selective wavelengths via DNS. The friction Reynolds number is set at 180. For Case ST, resolvent analysis predicts drag reduction at long streamwise wavelengths. DNS with control applied only for this spectral region, however, did not result in drag reduction. Then, we seek an effective control law using resolvent analysis and propose a new law. DNS results for this law are consistent with predictions from resolvent analysis, and about 10% drag reduction is attained. Further, we discuss how this law reduces the drag from a dynamical and theoretical point of view. This work was supported through Grant-in-Aid for Scientic Research (C) (No. 25420129) by Japan Society for the Promotion of Science (JSPS).

  7. Solid oxide reversible cells (SORCs) using LaGaO3-based oxide electrolyte and oxide fuel electrode

    Science.gov (United States)

    Ishihara, Tatsumi

    2017-09-01

    Activity of La0.8Sr0.2FeO3 (LSF) to the fuel electrode reaction in Solid Oxide Reversible Cells (SORCs) was investigated by using La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) and Ba0.6La0.4CoO3 (BLC) as electrolyte and air electrode, respectively. In electrolysis mode (SOEC), LSF electrode exhibited small overpotential under the atmosphere without H2 co-feeding; the current densities reached -1.42, -0.92, -0.36 A/cm2 at 1.4 V at 900, 800, 700 °C, respectively and H2 formation rate is well agreed with that estimated by Faraday's law. On the other hand, in the SOEC-SOFC reversible mode with the gas composition of 20% steam /20%H2/60%Ar, the maximum power densities of 0.42, 0.28, 0.11 W/cm2 were achieved at 900, 800 and 700 °C, respectively. In addition, the cyclic reversible operation was also investigated at 800 °C, and it was found that the cell showed high stability over 30 cycles. DC polarization measurement suggests that the exchange current density of LSF is 14 mA/cm2 at 700 °C, which is almost the same with that of Ni-YSZ reported. XRD measurement and SEM observation after the reversible measurement suggest that LSF is highly stable under SOEC-SOFC cyclic operation condition. Therefore, LSF is promising as the fuel electrode for SORCs, although the conductivity is not sufficiently high as electrode.

  8. Effect of PVA Blending on Structural and Ion Transport Properties of CS:AgNt-Based Polymer Electrolyte Membrane

    Directory of Open Access Journals (Sweden)

    Shujahadeen B. Aziz

    2017-11-01

    Full Text Available In this work, the role of poly(vinyl alcohol (PVA blending on structural and electrical properties of chitosan:silver nitrate systems is studied. The X-ray diffraction (XRD results show that the crystalline phase of chitosan (CS is greatly scarified by silver nitrate (AgNt salt. The crystalline domain of CS:AgNt is more broadened at 10 wt % of PVA. The spike and semicircular arcs can be separated in impedance plots. At high temperatures, the spike regions remained. The direct current (DC conductivity was calculated from the bulk resistance obtained from the impedance plots. The dielectric constant and DC conductivity versus PVA content exhibited similar behavior. The maximum DC conductivity at ambient temperature was 1.1 × 10−6 S/cm for 10 wt % of PVA. The DC ionic conductivity increased to 9.95 × 10−5 S/cm at 80 °C. Above 10 wt % of PVA, the drop in DC conductivity and dielectric constant were observed due to the increase in viscosity. Shifting of relaxation peaks towards the lower frequency revealed the increase of resistivity of the samples. The linear increase of DC conductivity versus 1000/T indicated that ion transport followed the Arrhenius model. The incomplete semicircular arc in Argand plots indicated the non-Debye type of relaxation process. The Argand plots were used to distinguish between conductivity relaxation and viscoelastic relaxation. Three regions were distinguished in the alternating current (AC spectra of the blend electrolyte samples. The plateau region in AC spectra was used to estimate the DC conductivity. The estimated DC conductivity from the AC spectra was close to those calculated from the impedance plots.

  9. Electrical Properties Of Indium And Yttrium-Doped Barium Cerate-Based Compounds For Use As Ceramic Fuel Cell Electrolytes

    Directory of Open Access Journals (Sweden)

    Gawel R.

    2015-06-01

    Full Text Available The aim of this work is to compare the electrical properties of BaCe0.85Y0.15O3−δ (BCY15, BaCe0.70In0.30O3−δ (BCI30 and a composite material consisting of 30%vol. BCY15 and 70%vol. Ce0.85Y0.15O2−δ (YDC15. BCY15 and YDC15 were synthesized by co-precipitation, whereas BCI30 was obtained using the solid-state reaction method. Pellets were initially formed from powders at 5 MPa, after which they were isostatically pressed at 250 MPa and sintered at 1500°C. Electrochemical impedance spectroscopy (EIS was used to determine the electrical properties of the samples in both air (pO2 = 0.021 MPa and Ar-5%H2 atmospheres. In the temperature range 200-400°C in air atmosphere the highest conductivity values were determined for BCY15 (5,22·10−5 − 2.74·10−3 S/cm. On the other hand, the electrical conductivity values obtained for Y70B30 in both atmospheres between 200 and 550°C are in the order of magnitude of 10−7 − 10−3 S/cm. Consequently, it can be concluded that the compounds exhibit significant H+ and O2− electrical conductivity at temperatures above 500°C, which indicates the possibility for their potential use as ceramic fuel cell electrolytes.

  10. Tunable photovoltaic performance of preferentially oriented rutile TiO2 nanorod photoanodes based dye sensitized solar cells with quasi-state electrolyte.

    Science.gov (United States)

    T C, Sabari Girisun; C, Jeganathan; N, Pavithra; Anandan, Sambandam

    2017-12-20

    Photoanodes made of highly oriented TiO2 nanorod arrays with different aspect ratios were synthesized via one-step hydrothermal technique. Preferentially oriented single crystalline rutile TiO2 was confirmed by the single peak in XRD pattern (2θ=63o, (0 0 2)). FESEM image evidence the growth of an array of nanorods having different geometry with respect to reaction time and solution refreshment rate. The length, diameter and aspect ratio of the nanorods increased with reaction time as 4 hours (1.98 μm, 121 nm, 15.32), 8 hours (4 μm, 185 nm, 22.70), 12 hours (5.6 μm, 242 nm, 27.24) and 16 hours (8 μm, 254 nm, 38.02) respectively. Unlike conventional Dye-Sensitized Solar Cell (DSSC) with a liquid electrolyte, DSSC were fabricated here using 1D rutile TiO2 nanorods based photoanodes, N719 dye and quasi-state electrolyte. The charge transport properties were investigated from current-voltage curves and fitted using one-diode model. Interestingly photovoltaic performance of DSSCs increased exponentially with the length of the nanorod and is attributed to the higher surface to volume ratio, more dye anchoring, and channelized electron transport. Higher photovoltaic performance (Jsc=5.99 mA/cm2, Voc=750 mV, η=3.08%) was observed with photoanodes (16 hours) made of densely packed longest TiO2 nanorods (8 µm, 254 nm). © 2017 IOP Publishing Ltd.

  11. Tunable photovoltaic performance of preferentially oriented rutile TiO2 nanorod photoanode based dye sensitized solar cells with quasi-state electrolyte

    Science.gov (United States)

    Sabari Girisun, T. C.; Jeganathan, C.; Pavithra, N.; Anandan, S.

    2018-02-01

    Photoanodes made of highly oriented TiO2 nanorod (NR) arrays with different aspect ratios were synthesized via a one-step hydrothermal technique. Preferentially oriented single crystalline rutile TiO2 was confirmed by the single peak in an XRD pattern (2θ = 63°, (0 0 2)). FESEM images evidenced the growth of an array of NRss having different geometries with respect to reaction time and solution refreshment rate. The length, diameter and aspect ratio of the NRs increased with reaction time as 4 h (1.98 μm, 121 nm, 15.32), 8 h (4 μm, 185 nm, 22.70), 12 h (5.6 μm, 242 nm, 27.24) and 16 h (8 μm, 254 nm, 38.02), respectively. Unlike a conventional dye-sensitized solar cell (DSSC) with a liquid electrolyte, DSSCs were fabricated here using one-dimensional rutile TiO2 NR based photoanodes, N719 dye and a quasi-state electrolyte. The charge transport properties were investigated using current–voltage curves and fitted using the one-diode model. Interestingly the photovoltaic performance of the DSSCs increased exponentially with the length of the NR and was attributed to a higher surface to volume ratio, more dye anchoring, and channelized electron transport. The higher photovoltaic performance (Jsc = 5.99 mA cm‑2, Voc = 750 mV, η = 3.08%) was observed with photoanodes (16 h) made with the longer, densely packed TiO2 NRs (8 μm, 254 nm).

  12. Changes in oxygen content and acid-base balance in arterial and portal blood in response to the dietary electrolyte balance in pigs during a 9-h period after a meal

    NARCIS (Netherlands)

    Dersjant-Li, Y.; Verstegen, M.W.A.; Jansman, A.; Schulze, H.; Schrama, J.W.; Verreth, J.A.J.

    2002-01-01

    The effect of two dietary electrolyte balance (dEB, Na K - Cl-) levels on arterial and portal blood oxygen content, blood pH, and acid-base status in pigs was studied during a 9-h period after a meal, using a crossover experimental design. The dEB levels were established by changing the Cl- level in

  13. Speckle reduction methods in laser-based picture projectors

    Science.gov (United States)

    Akram, M. Nadeem; Chen, Xuyuan

    2016-02-01

    Laser sources have been promised for many years to be better light sources as compared to traditional lamps or light-emitting diodes (LEDs) for projectors, which enable projectors having wide colour gamut for vivid image, super brightness and high contrast for the best picture quality, long lifetime for maintain free operation, mercury free, and low power consumption for green environment. A major technology obstacle in using lasers for projection has been the speckle noise caused by to the coherent nature of the lasers. For speckle reduction, current state of the art solutions apply moving parts with large physical space demand. Solutions beyond the state of the art need to be developed such as integrated optical components, hybrid MOEMS devices, and active phase modulators for compact speckle reduction. In this article, major methods reported in the literature for the speckle reduction in laser projectors are presented and explained. With the advancement in semiconductor lasers with largely reduced cost for the red, green and the blue primary colours, and the developed methods for their speckle reduction, it is hoped that the lasers will be widely utilized in different projector applications in the near future.

  14. Communication: Modeling electrolyte mixtures with concentration dependent dielectric permittivity

    Science.gov (United States)

    Chen, Hsieh; Panagiotopoulos, Athanassios Z.

    2018-01-01

    We report a new implicit-solvent simulation model for electrolyte mixtures based on the concept of concentration dependent dielectric permittivity. A combining rule is found to predict the dielectric permittivity of electrolyte mixtures based on the experimentally measured dielectric permittivity for pure electrolytes as well as the mole fractions of the electrolytes in mixtures. Using grand canonical Monte Carlo simulations, we demonstrate that this approach allows us to accurately reproduce the mean ionic activity coefficients of NaCl in NaCl-CaCl2 mixtures at ionic strengths up to I = 3M. These results are important for thermodynamic studies of geologically relevant brines and physiological fluids.

  15. Applying Ecological Theory to Advance the Science and Practice of School-Based Prejudice Reduction Interventions

    Science.gov (United States)

    McKown, Clark

    2005-01-01

    Several school-based racial prejudice-reduction interventions have demonstrated some benefit. Ecological theory serves as a framework within which to understand the limits and to enhance the efficacy of prejudice-reduction interventions. Using ecological theory, this article examines three prejudice-reduction approaches, including social cognitive…

  16. Electrolytic variation for the anionic reduction for broilers in the region Variação eletrolítica pela redução aniônica para frangos na região do Cerrado

    Directory of Open Access Journals (Sweden)

    Ademir José Conte

    2010-03-01

    Full Text Available The best electrolyte balance value (EB for broilers performance from 1 to 7, 1 to 14, 1 to 21 and 1 to 42 days of age was evaluated. Eight hundred and sixty four male Ross chikens ageing one day old, were reared on floor covered with shaving woods and fed diets based in corn-soybean combined with -50; 0; 50; 100; 150 and 200 mEq/kg of EB. The experiment was analized as randomized block design with six replicates of 24 chicks each experimental unit. Weigh gain, feed intake, feed efficiency (FE were evaluated at 7, 14, 21 and 42 days of age. The best values of EB estimated were 173, 192 and 200 mEq/kg, respetivly for 14, 21 and 42 days of age. It was also observed that high levels of chlorine magnify the humidity of the litter by means of the increasing of the excretion of water.The best electrolyte balance value (EB for broilers performance from 1 to 7, 1 to 14, 1 to 21 and 1 to 42 days of age was evaluated. Eight hundred and sixty four male Ross chikens ageing one day old, were reared on floor covered with shaving woods and fed diets based in corn-soybean combined with -50; 0; 50; 100; 150 and 200 mEq/kg of EB. The experiment was analized as randomized block design with six replicates of 24 chicks each experimental unit. Weigh gain, feed intake, feed efficiency (FE were evaluated at 7, 14, 21 and 42 days of age. The best values of EB estimated were 173, 192 and 200 mEq/kg, respetivly for 14, 21 and 42 days of age. It was also observed that high levels of chlorine magnify the humidity of the litter by means of the increasing of the excretion of water.Objetivou-se determinar os melhores valores de balanço eletrolítico (BE para o desempenho de pintos de corte de um a 7; um a 14; um a 21 e um a 42 dias de idade. Utilizaram-se 864 pintinhos machos, Cobb, criados em galpão de alvenaria, cobertos com maravalha e alimentados com ração composta, principalmente milho e farelo de soja, combinadas com cinco níveis de balanço eletrolítico (- 50; 0

  17. Adaptive Sampling for Nonlinear Dimensionality Reduction Based on Manifold Learning

    DEFF Research Database (Denmark)

    Franz, Thomas; Zimmermann, Ralf; Goertz, Stefan

    2017-01-01

    We make use of the non-intrusive dimensionality reduction method Isomap in order to emulate nonlinear parametric flow problems that are governed by the Reynolds-averaged Navier-Stokes equations. Isomap is a manifold learning approach that provides a low-dimensional embedding space that is approxi......We make use of the non-intrusive dimensionality reduction method Isomap in order to emulate nonlinear parametric flow problems that are governed by the Reynolds-averaged Navier-Stokes equations. Isomap is a manifold learning approach that provides a low-dimensional embedding space...... that is approximately isometric to the manifold that is assumed to be formed by the high-fidelity Navier-Stokes flow solutions under smooth variations of the inflow conditions. The focus of the work at hand is the adaptive construction and refinement of the Isomap emulator: We exploit the non-Euclidean Isomap metric...

  18. Electrogeneration of hydrogen peroxide for electro-Fenton via oxygen reduction using polyacrylonitrile-based carbon fiber brush cathode

    International Nuclear Information System (INIS)

    Xia, Guangsen; Lu, Yonghong; Xu, Haibo

    2015-01-01

    Polyacrylonitrile-based carbon fiber brush (PAN-CFB) cathode was used to electrogenerate hydrogen peroxide (H 2 O 2 ) via oxygen reduction reaction (ORR) and to degrade phenol in electro-Fenton system. Due to inherent N-containing structure, PAN-CFB cathode generated H 2 O 2 efficiently (current efficiency at 300 mA >90%), showing high selectivity toward 2-electron ORR independent of medium (H 2 SO 4 , Na 2 SO 4 or NaOH). Moreover, the influence of parameters such as applied current, cathodic potential, electrolyte concentration and volume as well as electrode distance on H 2 O 2 electrogeneration was investigated in detail. Finally, the degradation of phenol was evaluated by ultraviolet (UV) spectra analysis and COD measurement. 86.2% of COD removal was achieved under the optimum conditions (pH 3, I = 300 mA, 0.3 mmol L −1 Fe 2+ ) after 240 min, meaning the almost complete degradation of phenol via electro-Fenton process using PAN-CFB cathode

  19. Enhanced charging capability of lithium metal batteries based on lithium bis(trifluoromethanesulfonyl)imide-lithium bis(oxalato)borate dual-salt electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Hongfa; Shi, Pengcheng; Bhattacharya, Priyanka; Chen, Xilin; Mei, Donghai; Bowden, Mark E.; Zheng, Jianming; Zhang, Ji-Guang; Xu, Wu

    2016-06-01

    Rechargeable lithium (Li) metal batteries with conventional LiPF6-carbonate electrolytes have been reported to fail quickly at charging current densities of about 1.0 mA cm-2 and above. In this work, we demonstrate the rapid charging capability of the Li||LiNi0.8Co0.15Al0.05O2 (NCA) cells enabled by a dual-salt electrolyte of LiTFSI-LiBOB in a carbonate solvent mixture. It is found that the thickness of solid electrolyte interphase (SEI) layer on Li metal anode largely increases with increasing charging current density. However, the cells using the LiTFSI-LiBOB dual-salt electrolyte significantly outperforms those using the LiPF6 electrolyte at high charging current densities. At the charging current density of 1.50 mA cm-2, the Li||NCA cells with the dual-salt electrolyte can still deliver a discharge capacity of 131 mAh g-1 and a capacity retention of 80% after 100 cycles, while those with the LiPF6 electrolyte start to show fast capacity fading after the 30th cycle and only exhibit a low capacity of 25 mAh g-1 and a low retention of 15% after 100 cycles. The reasons for the good chargeability and cycling stability of the cells using LiTFSI-LiBOB dual-salt electrolyte can be attributed to the good film-formation ability of the electrolyte on lithium metal anode and the highly conductive nature of the sulfur-rich interphase layer.

  20. Electrolytic hydrogen fuel production with solid polymer electrolyte technology.

    Science.gov (United States)

    Titterington, W. A.; Fickett, A. P.

    1973-01-01

    A water electrolysis technology based on a solid polymer electrolyte (SPE) concept is presented for applicability to large-scale hydrogen production in a future energy system. High cell current density operation is selected for the application, and supporting cell test performance data are presented. Demonstrated cell life data are included to support the adaptability of the SPE system to large-size hydrogen generation utility plants as needed for bulk energy storage or transmission. The inherent system advantages of the acid SPE electrolysis technology are explained. System performance predictions are made through the year 2000, along with plant capital and operating cost projections.