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Sample records for composite polymer-electrolyte membranes

  1. Solid polymer electrolyte composite membrane comprising laser micromachined porous support

    Science.gov (United States)

    Liu, Han [Waltham, MA; LaConti, Anthony B [Lynnfield, MA; Mittelsteadt, Cortney K [Natick, MA; McCallum, Thomas J [Ashland, MA

    2011-01-11

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 5 microns, are made by laser micromachining and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  2. Solid polymer electrolyte composite membrane comprising plasma etched porous support

    Science.gov (United States)

    Liu, Han; LaConti, Anthony B.

    2010-10-05

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 0.1 to 5 microns, are made by plasma etching and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  3. Polybenzimidazole and sulfonated polyhedral oligosilsesquioxane composite membranes for high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Aili, David; Allward, Todd; Alfaro, Silvia Martinez

    2014-01-01

    Composite membranes based on poly(2,2′(m-phenylene)-5,5́bibenzimidazole) (PBI) and sulfonated polyhedral oligosilsesquioxane (S-POSS) with S-POSS contents of 5 and 10wt.% were prepared by solution casting as base materials for high temperature polymer electrolyte membrane fuel cells. With membranes...

  4. Solid polymer electrolyte composite membrane comprising a porous support and a solid polymer electrolyte including a dispersed reduced noble metal or noble metal oxide

    Science.gov (United States)

    Liu, Han; Mittelsteadt, Cortney K; Norman, Timothy J; Griffith, Arthur E; LaConti, Anthony B

    2015-02-24

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a thin, rigid, dimensionally-stable, non-electrically-conducting support, the support having a plurality of cylindrical, straight-through pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores are unevenly distributed, with some or no pores located along the periphery and more pores located centrally. The pores are completely filled with a solid polymer electrolyte, the solid polymer electrolyte including a dispersed reduced noble metal or noble metal oxide. The solid polymer electrolyte may also be deposited over the top and/or bottom surfaces of the support.

  5. Electrochemical polymer electrolyte membranes

    CERN Document Server

    Fang, Jianhua; Wilkinson, David P

    2015-01-01

    Electrochemical Polymer Electrolyte Membranes covers PEMs from fundamentals to applications, describing their structure, properties, characterization, synthesis, and use in electrochemical energy storage and solar energy conversion technologies. Featuring chapters authored by leading experts from academia and industry, this authoritative text: Discusses cutting-edge methodologies in PEM material selection and fabricationPoints out important challenges in developing PEMs and recommends mitigation strategies to improve PEM performanceAnalyzes the cur

  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. 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...... 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....... With the thermally resistant polymer, e.g., polybenzimidazole or a mixture of polybenzimidazole and other thermoplastics as binder, the carbon-supported noble metal catalyst is tape-cast onto a hydrophobic supporting substrate. When doped with an acid mixture, electrodes are assembled with an acid doped solid...

  8. Polybenzimidazole/Mxene composite membranes for intermediate temperature polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Fei, Mingming; Lin, Ruizhi; Deng, Yuming; Xian, Hongxi; Bian, Renji; Zhang, Xiaole; Cheng, Jigui; Xu, Chenxi; Cai, Dongyu

    2018-01-01

    This report demonstrated the first study on the use of a new 2D nanomaterial (Mxene) for enhancing membrane performance of intermediate temperature (>100 °C) polymer electrolyte membrane fuel cells (ITPEMFCs). In this study, a typical Ti3C2T x -MXene was synthesized and incorporated into polybenzimidazole (PBI)-based membranes by using a solution blending method. The composite membrane with 3 wt% Ti3C2T x -MXene showed the proton conductivity more than 2 times higher than that of pristine PBI membrane at the temperature range of 100 °C-170 °C, and led to substantial increase in maximum power density of fuel cells by ˜30% tested at 150 °C. The addition of Ti3C2T x -MXene also improved the mechanical properties and thermal stability of PBI membranes. At 3 wt% Ti3C2T x -MXene, the elongation at break of phosphoric acid doped PBI remained unaffected at 150 °C, and the tensile strength and Young’s modulus was increased by ˜150% and ˜160%, respectively. This study pointed out promising application of MXene in ITPEMFCs.

  9. Investigation of a nanoconfined, ceramic composite, solid polymer electrolyte

    International Nuclear Information System (INIS)

    Jayasekara, Indumini; Poyner, Mark; Teeters, Dale

    2017-01-01

    The challenges for further development of lithium rechargeable batteries are finding electrolyte materials that are safe, have mechanical and thermal stability and have sufficiently high ionic conduction. Polymer electrolytes have many of these advantages, but suffer with low ionic conduction. This study involves the use of anodic aluminum oxide (AAO) membranes having nanochannels filled with polymer electrolyte to make composite solid electrolytes having ionic conductivity several orders of magnitude higher (10 −4 Ω ‐1 cm −1 ) than non-confined polymer. SEM, ac impedance spectroscopy, temperature dependence studies, XRD, ATR- FTIR and DSC studies were done in order to characterize and understand the behavior of nanoconfined polymer electrolytes. The composite polymer electrolyte was found to be more amorphous with polymer chains aligned in the direction of the nanochannels, which is felt to promote ion conduction. The electrolyte systems, confined in nanoporous membranes, can be used as electrolytes for the fabrication of a room temperature all solid state battery.

  10. Bacterial nanocellulose/Nafion composite membranes for low temperature polymer electrolyte fuel cells

    Science.gov (United States)

    Jiang, Gao-peng; Zhang, Jing; Qiao, Jin-li; Jiang, Yong-ming; Zarrin, Hadis; Chen, Zhongwei; Hong, Feng

    2015-01-01

    Novel nanocomposite membranes aimed for both proton-exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC) are presented in this work. The membranes are based on blending bacterial nanocellulose pulp and Nafion (abbreviated as BxNy, where x and y indicates the mass ratio of bacterial cellulose to Nafion). The structure and properties of BxNy membranes are characterized by FTIR, SEM, TG, DMA and EIS, along with water uptake, swelling behavior and methanol permeability tests. It is found that the BxNy composite membranes with reinforced concrete-like structure show excellent mechanical and thermal stability regardless of annealing. The water uptake plus area and volume swelling ratios are all decreased compared to Nafion membranes. The proton conductivities of pristine and annealed B1N9 are 0.071 and 0.056 S cm-1, respectively, at 30 °C and 100% humidity. Specifically, annealed B1N1 exhibited the lowest methanol permeability of 7.21 × 10-7 cm2 s-1. Through the selectivity analysis, pristine and annealed B1N7 are selected to assemble the MEAs. The performances of annealed B1N7 in PEMFC and DMFC show the maximum power densities of 106 and 3.2 mW cm-2, respectively, which are much higher than those of pristine B1N7 at 25 °C. The performances of the pristine and annealed B1N7 reach a level as high as 21.1 and 20.4 mW cm-2 at 80 °C in DMFC, respectively.

  11. 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.

  12. Mechanisms of proton conductance in polymer electrolyte membranes

    DEFF Research Database (Denmark)

    Eikerling, M.; Kornyshev, A. A.; Kuznetsov, A. M.

    2001-01-01

    We provide a phenomenological description of proton conductance in polymer electrolyte membranes, based on contemporary views of proton transfer processes in condensed media and a model for heterogeneous polymer electrolyte membrane structure. The description combines the proton transfer events...... in a single pore with the total pore-network performance and, thereby, relates structural and kinetic characteristics of the membrane. The theory addresses specific experimentally studied issues such as the effect of the density of proton localization sites (equivalent weight) of the membrane material...

  13. Nafion and modified-Nafion membranes for polymer electrolyte fuel

    Indian Academy of Sciences (India)

    Polymer electrolyte fuel cells (PEFCs) employ membrane electrolytes for proton transport during the cell reaction. The membrane forms a key component of the PEFC and its performance is controlled by several physical parameters, viz. water up-take, ion-exchange capacity, proton conductivity and humidity. The article ...

  14. Toughness of membranes applied in polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kiefer, J; Brack, H P; Scherer, G G [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Since several years we apply the radiation-grafting technique to prepare polymeric membranes for application in polymer electrolyte fuel cells (PEFCs). Our investigations presented here focus on changes in toughness of these materials after the various synthesis steps and the importance of membrane toughness for their application in PEFCs. (author) 2 figs., 4 refs.

  15. Solid polymer electrolyte water electrolyser based on Nafion-TiO{sub 2} composite membrane for high temperature operation

    Energy Technology Data Exchange (ETDEWEB)

    Baglio, V.; Antonucci, V.; Arico, A.S. [CNR-ITAE, Messina (Italy); Matteucci, F.; Martina, F.; Zama, I. [Tozzi Renewable Energy SpA, Mezzano (Italy); Ciccarella, G. [National Nanotechnology Laboratory (NNL) of INFM-CNR, Distretto Tecnologico ISUFI, Innovazione, Universita del Salento, Lecce (Italy); Arriaga, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Queretaro Sanfandila (Mexico); Ornelas, R.

    2009-06-15

    A composite Nafion-TiO{sub 2} membrane was manufactured by a recast procedure, using an in-house prepared TiO{sub 2}. This membrane has shown promising properties for high temperature operation in an SPE electrolyser allowing to achieve higher performance with respect to a commercial Nafion 115 membrane. This effect is mainly due to the water retention properties of the TiO{sub 2} filler. A promising increase in electrical efficiency was recorded at low current densities for the composite membrane-based SPE electrolyser at high temperature compared to conventional membrane-based devices. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  16. Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Viktor Johánek

    2016-01-01

    Full Text Available The chemical analysis of processes inside fuel cells under operating conditions in either direct or inverted (electrolysis mode and their correlation with potentiostatic measurements is a crucial part of understanding fuel cell electrochemistry. We present a relatively simple yet powerful experimental setup for online monitoring of the fuel cell exhaust (of either cathode or anode side downstream by mass spectrometry. The influence of a variety of parameters (composition of the catalyst, fuel type or its concentration, cell temperature, level of humidification, mass flow rate, power load, cell potential, etc. on the fuel cell operation can be easily investigated separately or in a combined fashion. We demonstrate the application of this technique on a few examples of low-temperature (70°C herein polymer electrolyte membrane fuel cells (both alcohol- and hydrogen-fed subjected to a wide range of conditions.

  17. 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.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  19. Study the effect of ion-complex on the properties of composite gel polymer electrolyte based on Electrospun PVdF nanofibrous membrane

    International Nuclear Information System (INIS)

    Li, Weili; Xing, Yujin; Wu, Yuhui; Wang, Jiawei; Chen, Lizhuang; Yang, Gang; Tang, Benzhong

    2015-01-01

    In this paper, nanofibrous membranes based on poly(vinylidene fluoride) (PVdF) doped with ion-complex (SiO 2 -PAALi) were prepared by electrospinning technique and the corresponding composite gel-polymer electrolytes (CGPEs) were obtained after being activated in liquid electrolyte. The microstructure, physical and electrochemical performances of the nanofibrous membranes and the corresponding CGPEs were studied by various measurements such as Fourier Transform Infrared Spectroscopy(FTIR), Scanning Electron Microscope (SEM), Differential Scanning Calorimetry (DSC), Thermal Gravimetric Analysis (TGA), Stress-strain test, Linear Sweep Voltammetry (LSV), AC impedance measurement and Charge/discharge cycle test. As to the ion-complex doped nanofibrous membranes, PVdF can provide mechanical support with network structure composed of fully interconnection; while the ion-complexes are absorbed onto the surface of the PVdF nanofibers evenly instead of being aggregated. With the help of doped ion-complex, the prepared nanofibrous membranes present good liquid electrolyte absorbability, excellent mechanical performance, and high decomposition temperature. For the corresponding CGPEs, they possess high ionic conductivity, wide electrochemical window, and good charge/discharge cycle performance

  20. Analysis of cerium-composite polymer-electrolyte membranes during and after accelerated oxidative-stability test

    Science.gov (United States)

    Shin, Dongwon; Han, Myungseong; Shul, Yong-Gun; Lee, Hyejin; Bae, Byungchan

    2018-02-01

    The oxidative stability of membranes constructed from a composite of pristine sulfonated poly(arylene ether sulfone) and cerium was investigated by conducting an accelerated oxidative-stability test at the open-circuit voltage (OCV). The membranes were analyzed in situ through OCV and impedance measurements, cyclic voltammetry, and linear-sweep voltammetry to monitor the electrochemical properties during the stability test. Although the high-frequency resistance of a composite membrane was slightly higher than that of a pristine membrane because of the exchange of protons from the sulfonic acid with cerium ions, the composite membrane maintained its potential for much longer than the pristine membrane. The effect of the cerium ions as radical scavengers was confirmed by analyzing the drain water and chemical structure after operation. These post-operation analyses confirmed that cerium ions improved the oxidative stability of the hydrocarbon-based polymer during fuel-cell operation. It is clear that the cerium-based radical scavengers prevented chemical degradation of the polymer membrane as well as the electrode in terms of hydrogen cross-over, polymer-chain scission, and the electrochemical surface area, while they rarely diffused outward from the membrane.

  1. The Characteristic Thickness of Polymer Electrolyte Membrane and the

    Czech Academy of Sciences Publication Activity Database

    Němec, Tomáš; Maršík, František; Mičan, O.

    2009-01-01

    Roč. 30, č. 7 (2009), s. 574-581 ISSN 0145-7632 R&D Projects: GA AV ČR KJB400760701; GA MŠk(CZ) 1M06031; GA ČR(CZ) GA101/07/1612 Institutional research plan: CEZ:AV0Z20760514 Keywords : hydrogen fuel cell * polymer electrolyte membrane * irreversible thermodynamics Subject RIV: BJ - Thermodynamics Impact factor: 0.841, year: 2009 http://dx.doi.org/10.1080/01457630802594978

  2. Fabrication of carbon-polymer composite bipolar plates for polymer electrolyte membrane fuel cells by compression moulding

    International Nuclear Information System (INIS)

    Raza, M.A.; Ahmed, R.; Saleem, A.; Din, R.U.

    2009-01-01

    Fuel cells are considered as one of the most important technologies to address the future energy and environmental pollution problems. These are the most promising power sources for road transportation and portable devices. A fuel cell is an electrochemical device that converts chemical energy into electrical energy. A fuel cell stack consists of bipolar plates and membrane electrode assemblies (MEA). The bipolar plate is by weight, volume and cost one of the most significant components of a fuel cell stack. Major functions of bipolar plates are to separate oxidant and fuel gas, provide flow channels, conduct electricity and provide heat transfer. Bipolar plates can be made from various materials including graphite, metals, carbon / carbon and carbon/ polymer composites. Materials for carbon-polymer composites are relatively inexpensive, less corrosive, strong and channels can be formed by means of a moulding process. Carbon-polymer composites are of two type i.e; thermosetting and thermoplastic. For thermosetting composite a bulk molding compound (BMC) was prepared by adding graphite, vinyl ester resin, methyl ethyl ketone peroxide and cobalt naphthalate. The BMC was thoroughly mixed, poured into a die mould of a bipolar plate with channels and hot pressed at a specific temperature and pressure. A bipolar plate was formed according to the die mould. Design of the mould is also discussed. Conducting polymers were also added to BMC to increase the conductivity of bipolar plates. Particle size of the graphite has also a significant effect on the conductivity of the bipolar plates. Thermoplastic composites were also prepared using polypropylene and graphite.

  3. Modification of chitosan membranes with nanosilica particles as polymer electrolyte membranes

    Energy Technology Data Exchange (ETDEWEB)

    Kusumastuti, Ella, E-mail: ella.kusuma@gmail.com; Siniwi, Widasari Trisna, E-mail: wsiniwi@gmail.com; Mahatmanti, F. Widhi; Jumaeri [Department of Chemistry, Faculty of Mathematics and Natural Sciences, State University of Semarang D6 Building 2" n" d floor, Sekaran Unnes Campus, Gunungpati, Semarang (Indonesia); Atmaja, Lukman; Widiastuti, Nurul [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Tenth November Institute of Technology Keputih ITS Campus, Sukolilo, Surabaya (Indonesia)

    2016-04-19

    Chitosan has been widely used as polymer matrix for Polymer Electrolyte Membrane (PEM) application replacing Nafion which has shortcomings in terms of high methanol permeability that degrades the performance of fuel cells. Chitosan membranes modification is performed by adding nanosilica to prevent methanol transport through the membrane. Nanosilica is synthesized by sol-gel method and the particle diameter is obtained by analysis using Breunner Emmet Teller (BET) that is 6.59 nm. Nanosilica is mixed with chitosan solution to obtain nanosilica-chitosan as polymer electrolyte membrane. The membranes are synthesized through phase inversion method with nanosilica composition including 0; 0.5; 1; 2; 3; 5; and 10% w/w of chitosan. Characterization of the membranes indicate that the results of water swelling, proton conductivity and methanol permeability of the membrane with 3% nanosilica respectively were 49.23%, 0.231 S/cm, and 5.43 x 10{sup −7} cm{sup 2}/s. Based on the results of membrane selectivity calculation, the optimum membrane is the composition of 3% nanosilica with value 5.91 x 105 S s cm{sup −3}. The results of functional groups analysis with FTIR showed that it was only physical interaction that occurred between chitosan and nanosilica since no significant changes found in peak around the wave number 1000-1250 cm{sup −-1}.

  4. Composite gel polymer electrolyte for lithium ion batteries

    Science.gov (United States)

    Naderi, Roya

    Composite gel polymer electrolyte (CGPE) films, consisting of poly (vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) as the membrane, DMF and PC as solvent and plasticizing agent, mixture of charge modified TiO2 and SiO 2 nano particles as ionic conductors, and LiClO4+LiPF 6 as lithium salts were fabricated. Following the work done by Li et al., CGPE was coated on an O2-plasma treated trilayer polypropylene-polyethylene-polypropylene membrane separator using solution casting technique in order to improve the adhesive properties of gel polymer electrolyte to the separator membrane and its respective ionic conductivity due to decreasing the bulk resistance. In acidic CGPE with, the mixture of acid treated TiO2 and neutral SiO2 nano particles played the role of the charge modified nano fillers with enhanced hydroxyl groups. Likely, the mixture of neutral TiO 2 nano particles with basic SiO2 prepared through the hydrolization of tetraethyl orthosilicate (TEOS) provided a more basic environment due to the residues of NH4OH (Ammonium hydroxide) catalyst. The O2 plasma treated separator was coated with the solution of PVDF-HFP: modified nano fillers: Organic solvents with the mixture ratio of 0.1:0.01:1. After the evaporation of the organic solvents, the dried coated separator was soaked in PC-LiClO4+LiPF6 in EC: DMC:DEC (4:2:4 in volume) solution (300% wt. of PVDF-HFP) to form the final CGPE. Lim et al. has reported the enhanced ionic conductivity of 9.78*10-5 Scm-1 in an acidic composite polystyrene-Al2O3 solid electrolyte system with compared to that of basic and neutral in which the ionic conductivity undergoes an ion hopping process in solid interface rather than a segmental movement of ions through the plasticized polymer chain . Half-cells with graphite anode and Li metal as reference electrode were then assembled and the electrochemical measurements and morphology examinations were successfully carried out. Half cells demonstrated a considerable change in their

  5. NEW POLYMER ELECTROLYTE MEMBRANES FOR FUEL CELLS OPERATING ABOVE 100°C

    DEFF Research Database (Denmark)

    Li, Qingfeng; Jensen, Jens Oluf; He, Ronghuan

    2003-01-01

    The state-of-the-art of PEMFC technology is based on perfluorosulfonic acid (PFSA) polymer membranes operating at a typical temperature of 80°C. The newest development in the field is alternative polymer electrolytes for operation above 100°C. This paper is devoted to a review on the development......, which is classified into three groups: modified PFSA membranes, alternative sulfonated polymer and their inorganic composite membranes and acid-base complex membranes. High temperature PEMFC has been demonstrated with advanced features such as fast electrode kinetics, high CO tolerance, simple thermal...

  6. New materials for polymer electrolyte membrane fuel cell current collectors

    Science.gov (United States)

    Hentall, Philip L.; Lakeman, J. Barry; Mepsted, Gary O.; Adcock, Paul L.; Moore, Jon M.

    Polymer Electrolyte Membrane Fuel cells for automotive applications need to have high power density, and be inexpensive and robust to compete effectively with the internal combustion engine. Development of membranes and new electrodes and catalysts have increased power significantly, but further improvements may be achieved by the use of new materials and construction techniques in the manufacture of the bipolar plates. To show this, a variety of materials have been fabricated into flow field plates, both metallic and graphitic, and single fuel cell tests were conducted to determine the performance of each material. Maximum power was obtained with materials which had lowest contact resistance and good electrical conductivity. The performance of the best material was characterised as a function of cell compression and flow field geometry.

  7. 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.

  8. Novel cellulose reinforcement for polymer electrolyte membranes with outstanding mechanical properties

    International Nuclear Information System (INIS)

    Nair, Jijeesh R.; Chiappone, A.; Gerbaldi, C.; Ijeri, Vijaykumar S.; Zeno, E.; Bongiovanni, R.; Bodoardo, S.; Penazzi, N.

    2011-01-01

    Highlights: ► UV-cured methacrylic-based composite gel-polymer electrolyte membranes for rechargeable lithium batteries. ► Excellent mechanical stability by reinforcement with classical cellulose handsheets. ► Fast and environmentally friendly preparation process, green and low cost cellulose reinforcement. ► Good electrochemical behaviour, stable cyclability and long-term performances in real battery configuration. - Abstract: Methacrylic-based thermo-set gel-polymer electrolytes obtained by an easy and reliable free radical photo-polymerisation process demonstrate good behaviour in terms of ionic conductivity, interfacial stability with the Li-metal electrode and cyclability in lithium cells. Though the obtained membranes are flexible, self standing and easy to handle, there is room for improving mechanical strength. In this respect, a novel approach is adopted in this work, in which a cellulose hand-sheet (paper), specifically designed for the specific application, is used as a composite reinforcing agent. To enhance its compatibility with the polymer matrix, cellulose is modified by UV-grafting of poly(ethylene glycol) methyl ether methacrylate on it. Excellent mechanical properties are obtained and good overall electrochemical performances are maintained; highlighting that such specific approach would make these hybrid organic, green, cellulose-based composite polymer electrolyte systems a strong contender in the field of thin and flexible Li-based power sources.

  9. Dynamic water management of polymer electrolyte membrane fuel cells using intermittent RH control

    KAUST Repository

    Hussaini, I.S.; Wang, C.Y.

    2010-01-01

    A novel method of water management of polymer electrolyte membrane (PEM) fuel cells using intermittent humidification is presented in this study. The goal is to maintain the membrane close to full humidification, while eliminating channel flooding

  10. Approaches and Recent Development of Polymer Electrolyte Membranes For Fuel Cells Operational Above 100°C

    DEFF Research Database (Denmark)

    Li, Qingfeng; He, Ronghuan; Jensen, Jens Oluf

    2003-01-01

    The state-of-the-art of polymer electrolyte membrane fuel cell (PEMFC) technology is based on perfluorosulfonic acid (PFSA) polymer membranes operating at a typical temperature of 80 °C. Some of the key issues and shortcomings of the PFSA-based PEMFC technology are briefly discussed. These include...... water management, CO poisoning, hydrogen, reformate and methanol as fuels, cooling, and heat recovery. As a means to solve these shortcomings, hightemperature polymer electrolyte membranes for operation above 100 °C are under active development. This treatise is devoted to a review of the area...... encompassing modified PFSA membranes, alternative sulfonated polymer and their composite membranes, and acidbase complex membranes. PFSA membranes have been modified by swelling with nonvolatile solvents and preparing composites with hydrophilic oxides and solid proton conductors. DMFC and H2/O2(air) cells...

  11. Polymer Electrolyte Membranes for Water Photo-Electrolysis

    Science.gov (United States)

    Aricò, Antonino S.; Girolamo, Mariarita; Siracusano, Stefania; Sebastian, David; Baglio, Vincenzo; Schuster, Michael

    2017-01-01

    Water-fed photo-electrolysis cells equipped with perfluorosulfonic acid (Nafion® 115) and quaternary ammonium-based (Fumatech® FAA3) ion exchange membranes as separator for hydrogen and oxygen evolution reactions were investigated. Protonic or anionic ionomer dispersions were deposited on the electrodes to extend the interface with the electrolyte. The photo-anode consisted of a large band-gap Ti-oxide semiconductor. The effect of membrane characteristics on the photo-electrochemical conversion of solar energy was investigated for photo-voltage-driven electrolysis cells. Photo-electrolysis cells were also studied for operation under electrical bias-assisted mode. The pH of the membrane/ionomer had a paramount effect on the photo-electrolytic conversion. The anionic membrane showed enhanced performance compared to the Nafion®-based cell when just TiO2 anatase was used as photo-anode. This was associated with better oxygen evolution kinetics in alkaline conditions compared to acidic environment. However, oxygen evolution kinetics in acidic conditions were significantly enhanced by using a Ti sub-oxide as surface promoter in order to facilitate the adsorption of OH species as precursors of oxygen evolution. However, the same surface promoter appeared to inhibit oxygen evolution in an alkaline environment probably as a consequence of the strong adsorption of OH species on the surface under such conditions. These results show that a proper combination of photo-anode and polymer electrolyte membrane is essential to maximize photo-electrolytic conversion. PMID:28468242

  12. Investigation of dominant loss mechanisms in low-temperature polymer electrolyte membrane fuel cells

    OpenAIRE

    Gerteisen, D.

    2010-01-01

    This thesis deals with the analysis of dominant loss mechanisms in direct methanol fuel cells (DMFC) and hydrogen fed polymer electrolyte membrane fuel cells (PEFC) by means of experimental characterization and modeling work.

  13. Composite Polymer Electrolytes: Nanoparticles Affect Structure and Properties

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2016-11-01

    Full Text Available Composite polymer electrolytes (CPEs can significantly improve the performance in electrochemical devices such as lithium-ion batteries. This review summarizes property/performance relationships in the case where nanoparticles are introduced to polymer electrolytes. It is the aim of this review to provide a knowledge network that elucidates the role of nano-additives in the CPEs. Central to the discussion is the impact on the CPE performance of properties such as crystalline/amorphous structure, dielectric behavior, and interactions within the CPE. The amorphous domains of semi-crystalline polymer facilitate the ion transport, while an enhanced mobility of polymer chains contributes to high ionic conductivity. Dielectric properties reflect the relaxation behavior of polymer chains as an important factor in ion conduction. Further, the dielectric constant (ε determines the capability of the polymer to dissolve salt. The atom/ion/nanoparticle interactions within CPEs suggest ways to enhance the CPE conductivity by generating more free lithium ions. Certain properties can be improved simultaneously by nanoparticle addition in order to optimize the overall performance of the electrolyte. The effects of nano-additives on thermal and mechanical properties of CPEs are also presented in order to evaluate the electrolyte competence for lithium-ion battery applications.

  14. Recent progress in electrocatalysts with mesoporous structures for application in polymer electrolyte membrane fuel cells

    OpenAIRE

    Xing, Wei; Wu, Zucheng; Tao, Shanwen

    2016-01-01

    Recently mesoporous materials have drawn great attention in fuel cell related applications, such as preparation of polymer electrolyte membranes and catalysts, hydrogen storage and purification. In this mini-review, we focus on recent developments in mesoporous electrocatalysts for polymer electrolyte membrane fuel cells, including metallic and metal-free catalysts for use as either anode or cathode catalysts. Mesoporous Pt-based metals have been synthesized as anode catalysts with improved a...

  15. Ion transport property studies on PEO-PVP blended solid polymer electrolyte membranes

    International Nuclear Information System (INIS)

    Chandra, Angesh; Agrawal, R C; Mahipal, Y K

    2009-01-01

    The ion transport property studies on Ag + ion conducting PEO-PVP blended solid polymer electrolyte (SPE) membranes, (1 - x)[90PEO : 10AgNO 3 ] : xPVP, where x = 0, 1, 2, 3, 5, 7, 10 (wt%), are reported. SPE films were caste using a novel hot-press technique instead of the traditional solution cast method. The conventional solid polymeric electrolyte (SPE) film, (90PEO : 10AgNO 3 ), also prepared by the hot-press method and identified as the highest conducting composition at room temperature on the basis of PEO-AgNO 3 -salt concentration dependent conductivity studies, was used as the first-phase polymer electrolyte host into which PVP were dispersed as second-phase dispersoid. A two-fold conductivity enhancement from that of the PEO host could be achieved at room temperature for PVP blended SPE film composition: 98(90PEO : 10AgNO 3 ) : 2PVP. This has been referred to as optimum conducting composition (OCC). The formation of SPE membranes and material characterizations were done with the help of the XRD and DSC techniques. The ion transport mechanism in this SPE OCC has been characterized with the help of basic ionic parameters, namely ionic conductivity (σ), ionic mobility (μ), mobile ion concentration (n) and ionic transference number (t ion ). Solid-state polymeric batteries were fabricated using OCC as electrolyte and the cell-potential discharge characteristics were studied under different load conditions.

  16. A polymer electrolyte membrane for high temperature fuel cells to fit vehicle applications

    International Nuclear Information System (INIS)

    Li Mingqiang; Scott, Keith

    2010-01-01

    Poly(tetrafluoroethylene) PTFE/PBI composite membranes doped with H 3 PO 4 were fabricated to improve the performance of high temperature polymer electrolyte membrane fuel cells (HT-PEMFC). The composite membranes were fabricated by immobilising polybenzimidazole (PBI) solution into a hydrophobic porous PTFE membrane. The mechanical strength of the membrane was good exhibiting a maximum load of 35.19 MPa. After doping with the phosphoric acid, the composite membrane had a larger proton conductivity than that of PBI doped with phosphoric acid. The PTFE/PBI membrane conductivity was greater than 0.3 S cm -1 at a relative humidity 8.4% and temperature of 180 deg. C with a 300% H 3 PO 4 doping level. Use of the membrane in a fuel cell with oxygen, at 1 bar overpressure gave a peak power density of 1.2 W cm -2 at cell voltages >0.4 V and current densities of 3.0 A cm -2 . The PTFE/PBI/H 3 PO 4 composite membrane did not exhibit significant degradation after 50 h of intermittent operation at 150 deg. C. These results indicate that the composite membrane is a promising material for vehicles driven by high temperature PEMFCs.

  17. Polymer electrolyte membranes for fuel cells by radiation induced grafting with electron beam irradiation: state-of-the-art

    International Nuclear Information System (INIS)

    Nasef, M.M.; Nasef, M.M.

    2010-01-01

    Polymer electrolyte membranes have generated considerable interest in various fields of industrial interest due to their wide spread applications in fuel cells, batteries, electrolyzers sensors and actuators. Such diversity in applications implies a strong demand to architect the membranes towards particular properties for specific applications. Radiation induced grafting of vinyl and acrylic monomers into polymeric films, is an appealing method for producing various polymer electrolyte membranes. This method has the advantages of simplicity, controllability over the composition leading to tailored membrane properties and absence of shaping problem as preparation starts with substrate in a film form. It also has the flexibility of using various types of radiation sources such as gamma-rays and electron beam. Of all, electron beam (EB) accelerator is an advantageous source of high energy radiation that can initiate grafting reactions required for preparation of the membranes particularly when pilot scale production and commercial applications are sought. The grafting penetration can be varied from surface to bulk of membranes depending on the acceleration energy. This lecture reviews the-state of- the-art in the use of EB irradiation in preparation of composite and grafted polymer electrolyte membranes for fuel cell applications by radiation induced grafting with simultaneous irradiation and preirradiation methods. The use of simultaneous EB irradiation method was found to simplify the process and reduce the reaction time as well as the monomer consumption whereas the use of preirradiation method in a single-step route provides a shorter route to prepare polymer electrolyte membranes with improved properties and reduced cost in addition of setting basis for designing a continuous line to produce these membranes with dedicated EB facilities

  18. Low Permeable Hydrocarbon Polymer Electrolyte Membrane for Vanadium Redox Flow Battery.

    Science.gov (United States)

    Jung, Ho-Young; Moon, Geon-O; Jung, Seunghun; Kim, Hee Tak; Kim, Sang-Chai; Roh, Sung-Hee

    2017-04-01

    Polymer electrolyte membrane (PEM) confirms the life span of vanadium redox flow battery (VRFB). Products from Dupont, Nafion membrane, is mainly used for PEM in VRFB. However, permeation of vanadium ion occurs because of Nafion’s high permeability. Therefore, the efficiency of VRFB decreases and the prices becomes higher, which hinders VRFB’s commercialization. In order to solve this problem, poly(phenylene oxide) (PPO) is sulfonated for the preparation of low-priced hydrocarbon polymer electrolyte membrane. sPPO membrane is characterized by fundamental properties and VRFB cell test.

  19. Characteristics of Subfreezing Operation of Polymer Electrolyte Membrane Fuel Cells

    Science.gov (United States)

    Mishler, Jeffrey Harris

    Polymer Electrolyte Membrane (PEM) Fuel Cells are capable of high efficiency operation, and are free of NOx, SOx, and CO2 emissions when using hydrogen fuel, and ideally suited for use in transportation applications due to their high power density and low operating temperatures. However, under subfreezing conditions which may be encountered during winter seasons in some areas, product water will freeze within the membrane, cathode side catalyst layer and gas diffusion media, leading to voltage loss and operation failure. Experiments were undertaken in order to characterize the amount and location of water during fuel cell operation. First, in-situ neutron radiography was undertaken on the fuel cells at a normal operating temperature for various operating current densities, inlet relative humidities, and diffusion media hydrophobicities. It was found that more hydrophobic cathode microporous layer (MPL) or hydrophilic anode MPL may result in a larger amount of water transporting back to the anode. The water profiles along the channels were measured and the point of liquid water emergence, where two phase flow begins, was compared to previous models. Secondly, under subfreezing temperatures, neutron imaging showed that water ice product accumulates because of lack of a water removal mechanism. Water was observed under both the lands and channels, and increased almost linearly with time. It is found that most ice exists in the cathode side. With evidence from experimental observation, a cold start model was developed and explained, following existing approaches in the literature. Three stages of cold start are explained: membrane saturation, ice storage in catalyst layer pores, and then ice melting. The voltage losses due to temperature change, increased transport resistance, and reduced electrochemical surface area. The ionic conductivity of the membrane at subfreezing temperatures was modeled. Voltage evolution over time for isothermal cold starts was predicted and

  20. Radiolytic preparation of PFA-g-PVBSA membranes as a polymer electrolyte membrane

    Energy Technology Data Exchange (ETDEWEB)

    Fei Geng [Department of Chemistry and Materials Engineering, Changshu Institute of Technology, Nansanhuan Road 99, Changshu, Jiangsu 215-500 (China); Hwang, Mi-Lim; Sohn, Joon-Yong; Nho, Young Chang [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of); Shin, Junhwa, E-mail: shinj@kaeri.re.kr [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of)

    2012-03-01

    In this study, a polymer electrolyte membrane, PFA-g-PVBSA was prepared through the radiation-induced graft copolymerization of vinylbenzyl chloride (VBC) monomer onto a poly(tetrafluoroethylene-co-perfluoropropylvinyl ether) (PFA) film and subsequent sulfonation processes. The IEC values and water uptakes of the prepared membranes increased when increasing the contents of the poly(vinylbenzyl sulfonic acid) (PVBSA) graft polymers in the membranes. Compared with Nafion 212, the degree of grafting (DOG) of membranes of 50% and 70% showed higher proton conductivity with significantly lower methanol permeability. The combination of these properties suggests that the prepared membranes are promising for future application in direct methanol fuel cells.

  1. Nafion-TiO{sub 2} hybrid membranes for medium temperature polymer electrolyte fuel cells (PEFCs)

    Energy Technology Data Exchange (ETDEWEB)

    Sacca, A.; Carbone, A.; Passalacqua, E. [CNR-ITAE, Via Salita S. Lucia Sopra Contesse, 98126 Messina (Italy); D' Epifanio, A.; Licoccia, S.; Traversa, E. [Department of Chemical Science and Technology, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Sala, E.; Traini, F.; Ornelas, R. [Nuvera Fuel Cells, Via Bistolfi 35, 20134 Milan (Italy)

    2005-12-01

    A nanocomposite re-cast Nafion hybrid membrane containing titanium oxide calcined at T=400{sup o}C as an inorganic filler was developed in order to work at medium temperature in polymer electrolyte fuel cells (PEFCs) maintaining a suitable membrane hydration under fuel cell operative critical conditions. Nanometre TiO{sub 2} powder was synthesized via a sol-gel procedure by a rapid hydrolysis of Ti(OiPr){sub 4}. The membrane was prepared by mixing a Nafion-dimethylacetammide (DMAc) dispersion with a 3wt% of TiO{sub 2} powder and casting the mixture by Doctor Blade technique. The resulting film was characterised in terms of water uptake and ion exchange capacity (IEC). The membrane was tested in a single cell from 80 to 130{sup o}C in humidified H{sub 2}/air. The obtained results were compared with the commercial Nafion115 and a home-made recast Nafion membrane. Power density values of 0.514 and 0.256Wcm{sup -2} at 0.56V were obtained at 110 and 130{sup o}C, respectively, for the composite Nafion-Titania membrane. Preliminary tests carried out using steam reforming (SR) synthetic fuel at about 110{sup o}C have highlighted the benefit of the inorganic filler introduction when PEFC operates at medium temperature and with processed hydrogen. (author)

  2. A Review on the Fabrication of Electro spun Polymer Electrolyte Membrane for Direct Methanol Fuel Cell

    International Nuclear Information System (INIS)

    Junoh, H.; Jaafar, J.; Norddin, M.N.A.M.; Ismail, A.F.; Othman, M.H.D.; Rahman, M.A.; Yusof, N.; Salleh, W.N.W.; Junoh, H.; Jaafar, J.; Norddin, M.N.A.M.; Ismail, A.F.; Othman, M.H.D.; Rahman, M.A.; Yusof, N.; Salleh, W.N.W.; Hamid Ilbeygi, H.

    2014-01-01

    Proton exchange membrane (PEM) is an electrolyte which behaves as important indicator for fuel cell’s performance. Research and development (R and D) on fabrication of desirable PEM have burgeoned year by year, especially for direct methanol fuel cell (DMFC). However, most of the R and Ds only focus on the parent polymer electrolyte rather than polymer inorganic composites. This might be due to the difficulties faced in producing good dispersion of inorganic filler within the polymer matrix, which would consequently reduce the DMFC’s performance. Electro spinning is a promising technique to cater for this arising problem owing to its more widespread dispersion of inorganic filler within the polymer matrix, which can reduce the size of the filler up to nano scale. There has been a huge development on fabricating electrolyte nano composite membrane, regardless of the effect of electro spun nano composite membrane on the fuel cell’s performance. In this present paper, issues regarding the R and D on electro spun sulfonated poly (ether ether ketone) (SPEEK)/inorganic nano composite fiber are addressed.

  3. PEGDA/PVdF/F127 gel type polymer electrolyte membranes for lithium secondary batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yan-Jie; Kim, Dukjoon [Department of Chemical Engineering, Polymer Technology Institute, Sungkyunkwan University, Suwon, Kyunggi 440-746 (Korea)

    2007-03-30

    A novel porous gel polymer electrolyte (GPE) membrane based on poly(ethylene glycol) diacrylate (PEGDA), poly(vinylidene fluoride) (PVdF), and polyethylene oxide-co-polypropylene oxide-co-polyethylene oxide (PEO-PPO-PEO, F127) was fabricated by a phase inversion technique. The PEGDA cross-linking oligomer could be randomly mixed with unraveled PVdF polymer chains to form the interpenetrating polymer network (IPN) structure. Several experimental techniques including infrared (IR) spectra, differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and potentiostat/galvanostat were employed to investigate the characteristics of the polymer membranes. PEGDA and F127 influenced the porous size and structure. The mechanical strength and flexibility of the membrane were controlled by its composition. The membrane with the composition of PEGDA/PVdF/F127 (0/4/4) showed the highest electrolyte uptake of 152.6% and the maximum ionic conductivity of 2.0 x 10{sup -3} S cm{sup -1} at room temperature. All GPEs prepared in this study were electrochemically stable up to 4.5 V. (author)

  4. Biodegradation test of SPS-LS blends as polymer electrolyte membrane fuel cells

    International Nuclear Information System (INIS)

    Putri, Zufira; Arcana, I Made

    2014-01-01

    Sulfonated polystyrene (SPS) can be applied as a proton exchange membrane fuel cell due to its fairly good chemical stability. In order to be applied as polymer electrolyte membrane fuel cells (PEMFCs), membrane polymer should have a good ionic conductivity, high proton conductivity, and high mechanical strength. Lignosulfonate (LS) is a complex biopolymer which has crosslinks and sulfonate groups. SPS-LS blends with addition of SiO 2 are used to increase the proton conductivity and to improve the mechanical properties and thermal stability. However, the biodegradation test of SPS-LS blends is required to determine whether the application of these membranes to be applied as an environmentally friendly membrane. In this study, had been done the synthesis of SPS, biodegradability test of SPS-LS blends with variations of LS and SiO 2 compositions. The biodegradation test was carried out in solid medium of Luria Bertani (LB) with an activated sludge used as a source of microorganism at incubation temperature of 37°C. Based on the results obtained indicated that SPS-LS-SiO 2 blends are more decomposed by microorganism than SPS-LS blends. This result is supported by analysis of weight reduction percentage, functional groups with Fourier Transform Infrared (FTIR) Spectroscopy, and morphological surface with Scanning Electron Microscopy (SEM)

  5. Biodegradation test of SPS-LS blends as polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Putri, Zufira, E-mail: zufira.putri@gmail.com, E-mail: arcana@chem.itb.ac.id; Arcana, I Made, E-mail: zufira.putri@gmail.com, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Groups, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung (Indonesia)

    2014-03-24

    Sulfonated polystyrene (SPS) can be applied as a proton exchange membrane fuel cell due to its fairly good chemical stability. In order to be applied as polymer electrolyte membrane fuel cells (PEMFCs), membrane polymer should have a good ionic conductivity, high proton conductivity, and high mechanical strength. Lignosulfonate (LS) is a complex biopolymer which has crosslinks and sulfonate groups. SPS-LS blends with addition of SiO{sub 2} are used to increase the proton conductivity and to improve the mechanical properties and thermal stability. However, the biodegradation test of SPS-LS blends is required to determine whether the application of these membranes to be applied as an environmentally friendly membrane. In this study, had been done the synthesis of SPS, biodegradability test of SPS-LS blends with variations of LS and SiO{sub 2} compositions. The biodegradation test was carried out in solid medium of Luria Bertani (LB) with an activated sludge used as a source of microorganism at incubation temperature of 37°C. Based on the results obtained indicated that SPS-LS-SiO{sub 2} blends are more decomposed by microorganism than SPS-LS blends. This result is supported by analysis of weight reduction percentage, functional groups with Fourier Transform Infrared (FTIR) Spectroscopy, and morphological surface with Scanning Electron Microscopy (SEM)

  6. Novel polybenzimidazole derivatives for high temperature polymer electrolyte membrane fuel cell applications

    Science.gov (United States)

    Xiao, Lixiang

    sulfonated aromatic polymers. 31P-NMR technique was also used together with the titration and conductivity measurements to study the hydrolysis processes of PBI polymers with different structures and to further understand the effect of the polymer structure, PPA solution parameters and process conditions on the resulting membrane properties. The PA doped PBI membranes from the PPA process generally exhibited high acid doping levels from approximately 10--50 moles of PA per PBI repeat unit, which contributed to their unprecedented high proton conductivity values in the range of 0.1--0.3 S/cm. Owing to the high molecular weight of the PBI polymers and the unique gel structures resulting from the PPA process, these membranes exhibited high mechanical properties at high acid doping levels. It has been shown that the PBIs with more para linkages generally gave membranes with higher PA doping levels, higher mechanical properties and higher proton conductivities. Preliminary fuel cell performance evaluations on selected PBI polymer compositions together with a ˜1200 hours' long-term fuel cell test demonstrated the feasibility of the novel PBI derivative polymer electrolyte membranes from the PPA process for operating a fuel cell at temperatures in excess of 120°C without any external humidification or pressure requirements.

  7. Lowering the platinum loading of high temperature polymer electrolyte membrane fuel cells with acid doped polybenzimidazole membranes

    DEFF Research Database (Denmark)

    Fernandez, Santiago Martin; Li, Qingfeng; Jensen, Jens Oluf

    2015-01-01

    Membrane electrode assemblies (MEAs) with ultra-low Pt loading electrodes were prepared for high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) based on acid doped polybenzimidazole. With no electrode binders or ionomers, the triple phase boundary of the catalyst layer was establ......Membrane electrode assemblies (MEAs) with ultra-low Pt loading electrodes were prepared for high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) based on acid doped polybenzimidazole. With no electrode binders or ionomers, the triple phase boundary of the catalyst layer...

  8. High resolution neutron imaging of water in the polymer electrolyte fuel cell membrane

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Partha P [Los Alamos National Laboratory; Makundan, Rangachary [Los Alamos National Laboratory; Spendelow, Jacob S [Los Alamos National Laboratory; Borup, Rodney L [Los Alamos National Laboratory; Hussey, D S [NIST; Jacobson, D L [NIST; Arif, M [NIST

    2009-01-01

    Water transport in the ionomeric membrane, typically Nafion{reg_sign}, has profound influence on the performance of the polymer electrolyte fuel cell, in terms of internal resistance and overall water balance. In this work, high resolution neutron imaging of the Nafion{reg_sign} membrane is presented in order to measure water content and through-plane gradients in situ under disparate temperature and humidification conditions.

  9. Performance of a polymer electrolyte membrane fuel cell with thin film catalyst electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Young Gab; Kim, Chang Soo; Peck, Dong Hyun; Shin, Dong Ryul [Korea Institute of Energy Research, Taejon (Korea, Republic of)

    1998-03-15

    In order to develop a kW-class polymer electrolyte membrane fuel cell (PEMFC), several electrodes have been fabricated by different catalyst layer preparation procedures and evaluated based on the cell performance. Conventional carbon paper and carbon cloth electrodes were fabricated using a ptfe-bonded Pt/C electrol catalyst by coating and rolling methods. Thin-film catalyst/ionomer composite layers were also formed on the membrane by direct coating and transfer printing techniques. The performance evaluation with catalyst layer preparation methods was carried out using a large or small electrode single cell. Conventional and thin film membrane and electrode assemblies (MEAs) with small electrode area showed a performance of 350 and 650 mA/cm{sup 2} at 0.6 V, respectively. The performance of direct coated thin film catalyst layer with 300 cm{sup 2} MEAs was higher than those of the conventional and transfer printing technique MEAs. The influence of some characteristic parameters of the thin film electrode on electrochemical performance was examined. Various other aspects of overall operation of PEMFC stacks were also discussed. (orig.)

  10. A Review on the Fabrication of Electrospun Polymer Electrolyte Membrane for Direct Methanol Fuel Cell

    Directory of Open Access Journals (Sweden)

    Hazlina Junoh

    2015-01-01

    Full Text Available Proton exchange membrane (PEM is an electrolyte which behaves as important indicator for fuel cell’s performance. Research and development (R&D on fabrication of desirable PEM have burgeoned year by year, especially for direct methanol fuel cell (DMFC. However, most of the R&Ds only focus on the parent polymer electrolyte rather than polymer inorganic composites. This might be due to the difficulties faced in producing good dispersion of inorganic filler within the polymer matrix, which would consequently reduce the DMFC’s performance. Electrospinning is a promising technique to cater for this arising problem owing to its more widespread dispersion of inorganic filler within the polymer matrix, which can reduce the size of the filler up to nanoscale. There has been a huge development on fabricating electrolyte nanocomposite membrane, regardless of the effect of electrospun nanocomposite membrane on the fuel cell’s performance. In this present paper, issues regarding the R&D on electrospun sulfonated poly (ether ether ketone (SPEEK/inorganic nanocomposite fiber are addressed.

  11. Luminescent Polymer Electrolyte Composites Using Silica Coated-Y2O3:Eu as Fillers

    Directory of Open Access Journals (Sweden)

    Mikrajuddin Abdullah

    2003-05-01

    Full Text Available Luminescent polymer electrolyte composites composed of silica coated Y2O3:Eu in polyethylene glycol (PEG matrix has been produced by initially synthesizing silica coated Y2O3:Eu and mixing with polyethylene glycol in a lithium salt solution. High luminescence intensity at round 600 nm contributed by electron transitions in Eu3+ (5D0 -> 7F0, 5D0 -> 7F1, and 5D0 -> 7F3 transitions were observed. The measured electrical conductivity was comparable to that reported for polymer electrolyte composites prepared using passive fillers (non luminescent. This approach is therefore promising for production of high intensity luminescent polymer electrolyte composites for use in development of hybrid battery/display.

  12. Enhancing ionic conductivity in composite polymer electrolytes with well-aligned ceramic nanowires

    Science.gov (United States)

    Liu, Wei; Lee, Seok Woo; Lin, Dingchang; Shi, Feifei; Wang, Shuang; Sendek, Austin D.; Cui, Yi

    2017-04-01

    In contrast to conventional organic liquid electrolytes that have leakage, flammability and chemical stability issues, solid electrolytes are widely considered as a promising candidate for the development of next-generation safe lithium-ion batteries. In solid polymer electrolytes that contain polymers and lithium salts, inorganic nanoparticles are often used as fillers to improve electrochemical performance, structure stability, and mechanical strength. However, such composite polymer electrolytes generally have low ionic conductivity. Here we report that a composite polymer electrolyte with well-aligned inorganic Li+-conductive nanowires exhibits an ionic conductivity of 6.05 × 10-5 S cm-1 at 30 ∘C, which is one order of magnitude higher than previous polymer electrolytes with randomly aligned nanowires. The large conductivity enhancement is ascribed to a fast ion-conducting pathway without crossing junctions on the surfaces of the aligned nanowires. Moreover, the long-term structural stability of the polymer electrolyte is also improved by the use of nanowires.

  13. PE-g-MMA polymer electrolyte membrane for lithium polymer battery

    Energy Technology Data Exchange (ETDEWEB)

    Gao Kun [Departments of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China)]. E-mail: gaokun@hit.edu.cn; Hu Xinguo [Departments of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Yi Tingfeng [Departments of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Dai Changsong [Departments of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China)

    2006-10-25

    PE-g-MMA membranes with different degrees of grafting (DG) were prepared by electron beam radiation-induced graft copolymerization of methylmethacrylate (MMA) monomer onto polyethylene (PE) separator. The grafted membranes (GMs) were characterized using SEM, FTIR. The new polymer electrolytes based on GMs were prepared through immersion in a solution of LiPF{sub 6}-EC/DMC (1:1 by volume). It was found that the GMs with different DG exhibited the different uptake and retention ability of liquid electrolyte. Moreover, the ion conductivities of activated polymer electrolytes (APEs) were also found to vary with the different DG and reached a magnitude of 10{sup -3} S cm{sup -1} at the DG of 42%. Compared with those containing PE separators, the LiCoO{sub 2}-MCMB coin cells containing GMs demonstrated better cycle life and excellent rate performance.

  14. PE-g-MMA polymer electrolyte membrane for lithium polymer battery

    International Nuclear Information System (INIS)

    Gao Kun; Hu Xinguo; Yi Tingfeng; Dai Changsong

    2006-01-01

    PE-g-MMA membranes with different degrees of grafting (DG) were prepared by electron beam radiation-induced graft copolymerization of methylmethacrylate (MMA) monomer onto polyethylene (PE) separator. The grafted membranes (GMs) were characterized using SEM, FTIR. The new polymer electrolytes based on GMs were prepared through immersion in a solution of LiPF 6 -EC/DMC (1:1 by volume). It was found that the GMs with different DG exhibited the different uptake and retention ability of liquid electrolyte. Moreover, the ion conductivities of activated polymer electrolytes (APEs) were also found to vary with the different DG and reached a magnitude of 10 -3 S cm -1 at the DG of 42%. Compared with those containing PE separators, the LiCoO 2 -MCMB coin cells containing GMs demonstrated better cycle life and excellent rate performance

  15. PE-g-MMA polymer electrolyte membrane for lithium polymer battery

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Kun; Hu, Xinguo; Yi, Tingfeng; Dai, Changsong [Departments of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China)

    2006-10-25

    PE-g-MMA membranes with different degrees of grafting (DG) were prepared by electron beam radiation-induced graft copolymerization of methylmethacrylate (MMA) monomer onto polyethylene (PE) separator. The grafted membranes (GMs) were characterized using SEM, FTIR. The new polymer electrolytes based on GMs were prepared through immersion in a solution of LiPF{sub 6}-EC/DMC (1:1 by volume). It was found that the GMs with different DG exhibited the different uptake and retention ability of liquid electrolyte. Moreover, the ion conductivities of activated polymer electrolytes (APEs) were also found to vary with the different DG and reached a magnitude of 10{sup -3}Scm{sup -1} at the DG of 42%. Compared with those containing PE separators, the LiCoO{sub 2}-MCMB coin cells containing GMs demonstrated better cycle life and excellent rate performance. (author)

  16. Nanomaterials for Polymer Electrolyte Membrane Fuel Cells; Materials Challenges Facing Electrical Energy Storate

    Energy Technology Data Exchange (ETDEWEB)

    Gopal Rao, MRS Web-Editor; Yury Gogotsi, Drexel University; Karen Swider-Lyons, Naval Research Laboratory

    2010-08-05

    Symposium T: Nanomaterials for Polymer Electrolyte Membrane Fuel Cells Polymer electrolyte membrane (PEM) fuel cells are under intense investigation worldwide for applications ranging from transportation to portable power. The purpose of this seminar is to focus on the nanomaterials and nanostructures inherent to polymer fuel cells. Symposium topics will range from high-activity cathode and anode catalysts, to theory and new analytical methods. Symposium U: Materials Challenges Facing Electrical Energy Storage Electricity, which can be generated in a variety of ways, offers a great potential for meeting future energy demands as a clean and efficient energy source. However, the use of electricity generated from renewable sources, such as wind or sunlight, requires efficient electrical energy storage. This symposium will cover the latest material developments for batteries, advanced capacitors, and related technologies, with a focus on new or emerging materials science challenges.

  17. Performance enhancement of membrane electrode assemblies with plasma etched polymer electrolyte membrane in PEM fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong-Hun; Yoon, Won-Sub [School of Advanced Materials Engineering, Kookmin University, 861-1 Jeongneung-dong, Seongbuk-gu, Seoul 136-702 (Korea); Bae, Jin Woo; Cho, Yoon-Hwan; Lim, Ju Wan; Ahn, Minjeh; Jho, Jae Young; Sung, Yung-Eun [World Class University (WCU) program of Chemical Convergence for Energy and Environment (C2E2), School of Chemical and Biological Engineering, College of Engineering, Seoul National University (SNU), 599 Gwanak-Ro, Gwanak-gu, Seoul 151-744 (Korea); Kwon, Nak-Hyun [Fuel Cell Vehicle Team 3, Advanced Technology Center, Corporate Research and Development Division, Hyundai-Kia Motors, 104 Mabuk-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-912 (Korea)

    2010-10-15

    In this work, a surface modified Nafion 212 membrane was fabricated by plasma etching in order to enhance the performance of a membrane electrode assembly (MEA) in a polymer electrolyte membrane fuel cell. Single-cell performance of MEA at 0.7 V was increased by about 19% with membrane that was etched for 10 min compared to that with untreated Nafion 212 membrane. The MEA with membrane etched for 20 min exhibited a current density of 1700 mA cm{sup -2} at 0.35 V, which was 8% higher than that of MEA with untreated membrane (1580 mA cm{sup -2}). The performances of MEAs containing etched membranes were affected by complex factors such as the thickness and surface morphology of the membrane related to etching time. The structural changes and electrochemical properties of the MEAs with etched membranes were characterized by field emission scanning electron microscopy, Fourier transform-infrared spectrometry, electrochemical impedance spectroscopy, and cyclic voltammetry. (author)

  18. Increased Water Retention in Polymer Electrolyte Membranes at Elevated Temperatures Assisted by Capillary Condensation

    International Nuclear Information System (INIS)

    Park, M.J.; Downing, K.H.; Jackson, A.; Gomez, E.D.; Minor, A.M.; Cookson, D.; Weber, A.Z.; Balsara, N.P.

    2007-01-01

    We establish a new systematic methodology for controlling the water retention of polymer electrolyte membranes. Block copolymer membranes comprising hydrophilic phases with widths ranging from 2 to 5 nm become wetter as the temperature of the surrounding air is increased at constant relative humidity. The widths of the moist hydrophilic phases were measured by cryogenic electron microscopy experiments performed on humid membranes. Simple calculations suggest that capillary condensation is important at these length scales. The correlation between moisture content and proton conductivity of the membranes is demonstrated.

  19. Increased water retention in polymer electrolyte membranes at elevated temperatures assisted by capillary condensation.

    Science.gov (United States)

    Park, Moon Jeong; Downing, Kenneth H; Jackson, Andrew; Gomez, Enrique D; Minor, Andrew M; Cookson, David; Weber, Adam Z; Balsara, Nitash P

    2007-11-01

    We establish a new systematic methodology for controlling the water retention of polymer electrolyte membranes. Block copolymer membranes comprising hydrophilic phases with widths ranging from 2 to 5 nm become wetter as the temperature of the surrounding air is increased at constant relative humidity. The widths of the moist hydrophilic phases were measured by cryogenic electron microscopy experiments performed on humid membranes. Simple calculations suggest that capillary condensation is important at these length scales. The correlation between moisture content and proton conductivity of the membranes is demonstrated.

  20. CoPd x oxygen reduction electrocatalysts for polymer electrolyte membrane and direct methanol fuel cells

    International Nuclear Information System (INIS)

    Mustain, William E.; Kepler, Keith; Prakash, Jai

    2007-01-01

    The electrochemical activity of carbon-supported cobalt-palladium alloy electrocatalysts of various compositions have been investigated for the oxygen reduction reaction in a 5 cm 2 single cell polymer electrolyte membrane fuel cell. The polarization experiments have been conducted at various temperatures between 30 and 60 deg. C and the reduction performance compared with data from a commercial Pt catalyst under identical conditions. Investigation of the catalytic activity of the CoPd x PEMFC system with varying composition reveals that a nominal cobalt-palladium atomic ratio of 1:3, CoPd 3 , exhibits the best performance of all studied catalysts, exhibiting a catalytic activity comparable to the commercial Pt catalyst. The ORR on CoPd 3 has a low activation energy, 52 kJ/mol, and a Tafel slope of approximately 60 mV/decade, indicating that the rate-determining step is a chemical step following the first electron transfer step and may involve the breaking of the oxygen bond. The CoPd 3 catalyst also exhibits excellent chemical stability, with the open circuit cell voltage decreasing by only 3% and the observed current decreasing by only 10% at 0.8 V over 25 h. The CoPd 3 catalyst also exhibits superior tolerance to methanol crossover poisoning than Pt

  1. 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...... 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...

  2. Synthesis of polymer electrolyte membranes from cellulose acetate/poly(ethylene oxide)/LiClO{sub 4} for lithium ion battery application

    Energy Technology Data Exchange (ETDEWEB)

    Nurhadini,, E-mail: nur-chem@yahoo.co.id; Arcana, I Made, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Division, Faculty of Mathematics and Natural Sciences, Institiut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132 (Indonesia)

    2015-09-30

    This study was conducted to determine the effect of cellulose acetate on poly(ethylene oxide)-LiClO{sub 4} membranes as the polymer electrolyte. Cellulose acetate is used as an additive to increase ionic conductivity and mechanical property of polymer electrolyte membranes. The increase the percentage of cellulose acetate in membranes do not directly effect on the ionic conductivity, and the highest ionic conductivity of membranes about 5,7 × 10{sup −4} S/cm was observed in SA/PEO/LiClO{sub 4} membrane with cellulose ratio of 10-25% (w/w). Cellulose acetate in membranes increases mechanical strength of polymer electrolyte membranes. Based on TGA analysis, this polymer electrolyte thermally is stable until 270 °C. The polymer electrolyte membrane prepared by blending the cellulose acetate, poly(ethylene oxide), and lithium chlorate could be potentially used as a polymer electrolyte for lithium ion battery application.

  3. Modeling and Simulation for Fuel Cell Polymer Electrolyte Membrane

    Directory of Open Access Journals (Sweden)

    Takahiro Hayashi

    2013-01-01

    Full Text Available We have established methods to evaluate key properties that are needed to commercialize polyelectrolyte membranes for fuel cell electric vehicles such as water diffusion, gas permeability, and mechanical strength. These methods are based on coarse-graining models. For calculating water diffusion and gas permeability through the membranes, the dissipative particle dynamics–Monte Carlo approach was applied, while mechanical strength of the hydrated membrane was simulated by coarse-grained molecular dynamics. As a result of our systematic search and analysis, we can now grasp the direction necessary to improve water diffusion, gas permeability, and mechanical strength. For water diffusion, a map that reveals the relationship between many kinds of molecular structures and diffusion constants was obtained, in which the direction to enhance the diffusivity by improving membrane structure can be clearly seen. In order to achieve high mechanical strength, the molecular structure should be such that the hydrated membrane contains narrow water channels, but these might decrease the proton conductivity. Therefore, an optimal design of the polymer structure is needed, and the developed models reviewed here make it possible to optimize these molecular structures.

  4. The Effect of Platinum Electrocatalyst on Membrane Degradation in Polymer Electrolyte Fuel Cells.

    Science.gov (United States)

    Bodner, Merit; Cermenek, Bernd; Rami, Mija; Hacker, Viktor

    2015-12-08

    Membrane degradation is a severe factor limiting the lifetime of polymer electrolyte fuel cells. Therefore, obtaining a deeper knowledge is fundamental in order to establish fuel cells as competitive product. A segmented single cell was operated under open circuit voltage with alternating relative humidity. The influence of the catalyst layer on membrane degradation was evaluated by measuring a membrane without electrodes and a membrane-electrode-assembly under identical conditions. After 100 h of accelerated stress testing the proton conductivity of membrane samples near the anode and cathode was investigated by means of ex situ electrochemical impedance spectroscopy. The membrane sample near the cathode inlet exhibited twofold lower membrane resistance and a resulting twofold higher proton conductivity than the membrane sample near the anode inlet. The results from the fluoride ion analysis have shown that the presence of platinum reduces the fluoride emission rate; which supports conclusions drawn from the literature.

  5. High temperature polymer electrolyte membrane fuel cells: Approaches, status, and perspectives

    DEFF Research Database (Denmark)

    This book is a comprehensive review of high-temperature polymer electrolyte membrane fuel cells (PEMFCs). PEMFCs are the preferred fuel cells for a variety of applications such as automobiles, cogeneration of heat and power units, emergency power and portable electronics. The first 5 chapters...... of and motivated extensive research activity in the field. The last 11 chapters summarize the state-of-the-art of technological development of high temperature-PEMFCs based on acid doped PBI membranes including catalysts, electrodes, MEAs, bipolar plates, modelling, stacking, diagnostics and applications....

  6. Modelling multiphase flow inside the porous media of a polymer electrolyte membrane fuel cell

    DEFF Research Database (Denmark)

    Berning, Torsten; Kær, Søren Knudsen

    2011-01-01

    Transport processes inside polymer electrolyte membrane fuel cells (PEMFC’s) are highly complex and involve convective and diffusive multiphase, multispecies flow through porous media along with heat and mass transfer and electrochemical reactions in conjunction with water transport through...... an electrolyte membrane. We will present a computational model of a PEMFC with focus on capillary transport of water through the porous layers and phase change and discuss the impact of the liquid phase boundary condition between the porous gas diffusion layer and the flow channels, where water droplets can...

  7. Durability and degradation analysis of hydrocarbon ionomer membranes in polymer electrolyte fuel cells accelerated stress evaluation

    Science.gov (United States)

    Shimizu, Ryo; Tsuji, Junichi; Sato, Nobuyuki; Takano, Jun; Itami, Shunsuke; Kusakabe, Masato; Miyatake, Kenji; Iiyama, Akihiro; Uchida, Makoto

    2017-11-01

    The chemical durabilities of two proton-conducting hydrocarbon polymer electrolyte membranes, sulfonated benzophenone poly(arylene ether ketone) (SPK) semiblock copolymer and sulfonated phenylene poly(arylene ether ketone) (SPP) semiblock copolymer are evaluated under accelerated open circuit voltage (OCV) conditions in a polymer electrolyte fuel cell (PEFC). Post-test characterization of the membrane electrodes assemblies (MEAs) is carried out via gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy. These results are compared with those of the initial MEAs. The SPP cell shows the highest OCV at 1000 h, and, in the post-test analysis, the SPP membrane retains up to 80% of the original molecular weight, based on the GPC results, and 90% of the hydrophilic structure, based on the NMR results. The hydrophilic structure of the SPP membrane is more stable after the durability evaluation than that of the SPK. From these results, the SPP membrane, with its simple hydrophilic structure, which does not include ketone groups, is seen to be significantly more resistant to radical attack. This structure leads to high chemical durability and thus impedes the chemical decomposition of the membrane.

  8. Nafion/silane nanocomposite membranes for high temperature polymer electrolyte membrane fuel cell.

    Science.gov (United States)

    Ghi, Lee Jin; Park, Na Ri; Kim, Moon Sung; Rhee, Hee Woo

    2011-07-01

    The polymer electrolyte membrane fuel cell (PEMFC) has been studied actively for both potable and stationary applications because it can offer high power density and be used only hydrogen and oxygen as environment-friendly fuels. Nafion which is widely used has mechanical and chemical stabilities as well as high conductivity. However, there is a drawback that it can be useless at high temperatures (> or = 90 degrees C) because proton conducting mechanism cannot work above 100 degrees C due to dehydration of membrane. Therefore, PEMFC should be operated for long-term at high temperatures continuously. In this study, we developed nanocomposite membrane using stable properties of Nafion and phosphonic acid groups which made proton conducting mechanism without water. 3-Aminopropyl triethoxysilane (APTES) was used to replace sulfonic acid groups of Nafion and then its aminopropyl group was chemically modified to phosphonic acid groups. The nanocomposite membrane showed very high conductivity (approximately 0.02 S/cm at 110 degrees C, <30% RH).

  9. Sodium ion conducting polymer electrolyte membrane prepared by phase inversion technique

    Science.gov (United States)

    Harshlata, Mishra, Kuldeep; Rai, D. K.

    2018-04-01

    A mechanically stable porous polymer membrane of Poly(vinylidene fluoride-hexafluoropropylene) has been prepared by phase inversion technique using steam as a non-solvent. The membrane possesses semicrystalline network with enhanced amorphicity as observed by X-ray diffraction. The membrane has been soaked in an electrolyte solution of 0.5M NaPF6 in Ethylene Carbonate/Propylene Carbonate (1:1) to obtain the gel polymer electrolyte. The porosity and electrolyte uptake of the membrane have been found to be 67% and 220% respectively. The room temperature ionic conductivity of the membrane has been obtained as ˜ 0.3 mS cm-1. The conductivity follows Arrhenius behavior with temperature and gives activation energy as 0.8 eV. The membrane has been found to possess significantly large electrochemical stability window of 5.0 V.

  10. Preparation of polymer electrolyte membranes for lithium batteries by radiation-induced graft copolymerization

    Energy Technology Data Exchange (ETDEWEB)

    Nasef, Mohamed Mahmoud [Business and Advanced Technology Centre, Universiti Teknologi Malaysia, Jalan Semarak, 54100 Kuala Lumpur (Malaysia); Suppiah, Raja Rajeswary [Chemical Engineering Program, Universiti Teknologi Petronas, Bandar Seri Iskandar, 37150 Tronoh, Perak (Malaysia); Dahlan, Khairul Zaman Mohd [Malaysian Institute for Nuclear Technology Research, Bangi, 43000 Kajang (Malaysia)

    2004-07-30

    Polymer electrolyte membranes with different degrees of grafting were prepared by radiation-induced graft copolymerization of styrene monomer onto poly(vinylidene fluoride) (PVDF) films and subsequent chemical activation with liquid electrolyte consisting of lithium hexafluorophosphate (LiPF{sub 6}) in a mixture of ethylene carbonate/diethylene carbonate (EC/DEC). The chemical changes in the PVDF films after styrene grafting and subsequent chemical activation were monitored by FTIR spectroscopic analysis and the crystallinity was evaluated using differential scanning calorimetric (DSC) analysis. The swelling in electrolyte solution (electrolyte uptake) and the ionic conductivity of the membranes were determined at various degrees of grafting. The conductivity of the membranes was found to increase with the increase in the degree of grafting and reached a magnitude of 10{sup -3} S/cm at a degree of grafting of 50%. The results of this work suggest that radiation-induced graft polymerization provides an alternative method to substitute blending in preparation of polymer electrolyte membranes for application in lithium batteries.

  11. The effect of porosity on performance of phosphoric acid doped polybenzimidazole polymer electrolyte membrane fuel cell

    Directory of Open Access Journals (Sweden)

    Celik Muhammet

    2016-01-01

    Full Text Available A polybenzimidazole (PBI based polymer electrolyte fuel cells, which called high temperature polymer electrolyte fuel cells (HT-PEMS, operate at higher temperatures (120-200°C than conventional PEM fuel cells. Although it is known that HT-PEMS have some of the significant advantages as non-humidification requirements for membrane and the lack of liquid water at high temperature in the fuel cell, the generated water as a result of oxygen reduction reaction causes in the degradation of these systems. The generated water absorbed into membrane side interacts with the hydrophilic PBI matrix and it can cause swelling of membrane, so water transport mechanism in a membrane electrode assembly (MEA needs to be well understood and water balance must be calculated in MEA. Therefore, the water diffusion transport across the electrolyte should be determined. In this study, various porosity values of gas diffusion layers are considered in order to investigate the effects of porosity on the water management for two phase flow in fuel cell. Two-dimensional fuel cell with interdigitated flow-field is modelled using COMSOL Multiphysics 4.2a software. The operating temperature and doping level is selected as 160°C and 6.75mol H3PO4/PBI, respectively.

  12. Electrospun polyimide-based fiber membranes as polymer electrolytes for lithium-ion batteries

    International Nuclear Information System (INIS)

    Wang, Qiujun; Song, Wei-Li; Wang, Luning; Song, Yu; Shi, Qiao; Fan, Li-Zhen

    2014-01-01

    Polymer electrolytes based on electrospun polyimide (PI) membranes are incorporated with electrolyte solution containing 1 mol L −1 LiPF 6 /ethylene carbonate/ethylmethyl carbonate/dimethyl carbonate to examine their potential application for lithium ion batteries. The as-electrospun non-woven membranes demonstrate a uniformly interconnected structure with an average fiber diameter of 800 nm. The membranes, showing superior thermal stability and flame retardant property compared to the commercial Celgard® membranes, exhibit high porosity and high uptake when activated with the liquid electrolyte. The resulting PI electrolytes (PIs) have a high ionic conductivity up to 2.0 × 10 −3 S cm −1 at 25 °C, and exhibit a high electrochemical stability potential more than 5.0 V (vs. Li/Li + ). They also possess excellent charge/discharge performance and capacity retention. The initial discharge capacities of the Li/PIs/Li 4 Ti 5 O 12 cells are 178.4, 167.4, 160.3, 148.3 and 135.9 mAh g −1 at the charge/discharge rates of 0.2 C, 1 C, 2 C, 5 C and 10 C, respectively. After 200 cycles at 5 C, a capacity around ∼146.8 mAh g −1 can be still achieved. The PI-based polymer electrolytes with strong mechanical properties and good electrochemical performance are proved to be promising electrolytes for lithium ion batteries

  13. 35-We polymer electrolyte membrane fuel cell system for notebook computer using a compact fuel processor

    Science.gov (United States)

    Son, In-Hyuk; Shin, Woo-Cheol; Lee, Yong-Kul; Lee, Sung-Chul; Ahn, Jin-Gu; Han, Sang-Il; kweon, Ho-Jin; Kim, Ju-Yong; Kim, Moon-Chan; Park, Jun-Yong

    A polymer electrolyte membrane fuel cell (PEMFC) system is developed to power a notebook computer. The system consists of a compact methanol-reforming system with a CO preferential oxidation unit, a 16-cell PEMFC stack, and a control unit for the management of the system with a d.c.-d.c. converter. The compact fuel-processor system (260 cm 3) generates about 1.2 L min -1 of reformate, which corresponds to 35 We, with a low CO concentration (notebook computers.

  14. 35-We polymer electrolyte membrane fuel cell system for notebook computer using a compact fuel processor

    Energy Technology Data Exchange (ETDEWEB)

    Son, In-Hyuk; Shin, Woo-Cheol; Lee, Sung-Chul; Ahn, Jin-Gu; Han, Sang-Il; kweon, Ho-Jin; Kim, Ju-Yong; Park, Jun-Yong [Energy 1 Group, Energy Laboratory at Corporate R and D Center in Samsung SDI Co., Ltd., 575, Shin-dong, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-731 (Korea); Lee, Yong-Kul [Department of Chemical Engineering, Dankook University, Youngin 448-701 (Korea); Kim, Moon-Chan [Department of Environmental Engineering, Chongju University, Chongju 360-764 (Korea)

    2008-10-15

    A polymer electrolyte membrane fuel cell (PEMFC) system is developed to power a notebook computer. The system consists of a compact methanol-reforming system with a CO preferential oxidation unit, a 16-cell PEMFC stack, and a control unit for the management of the system with a d.c.-d.c. converter. The compact fuel-processor system (260 cm{sup 3}) generates about 1.2 L min{sup -1} of reformate, which corresponds to 35 We, with a low CO concentration (<30 ppm, typically 0 ppm), and is thus proven to be capable of being targetted at notebook computers. (author)

  15. Preparation and DMFC performance of a sulfophenylated poly(arylene ether ketone) polymer electrolyte membrane

    Energy Technology Data Exchange (ETDEWEB)

    Liu Baijun, E-mail: liubj@jlu.edu.c [College of Chemistry, Jilin University, Changchun 130012 (China); Hu Wei [College of Chemistry, Jilin University, Changchun 130012 (China); Kim, Yu Seung [Los Alamos National Laboratory, Electronic and Electrochemical Materials and Devices, Los Alamos, NM 87545 (United States); Zou Haifeng [College of Chemistry, Jilin University, Changchun 130012 (China); Robertson, Gilles P. [Institute for Chemical Process and Environmental Technology, National Research Council, Ottawa, Ontario K1A 0R6 (Canada); Jiang Zhenhua [College of Chemistry, Jilin University, Changchun 130012 (China); Guiver, Michael D. [Institute for Chemical Process and Environmental Technology, National Research Council, Ottawa, Ontario K1A 0R6 (Canada); Department of Energy Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)

    2010-04-15

    A sulfonated poly(aryl ether ether ketone ketone) (PEEKK) having a well-defined rigid homopolymer-like chemical structure was synthesized from a readily prepared PEEKK by post-sulfonation with concentrated sulfuric acid at room temperature within several hours. The polymer electrolyte membrane (PEM) cast from the resulting polymer exhibited an excellent combination of thermal resistance, oxidative and dimensional stability, low methanol fuel permeability and high proton conductivity. Furthermore, membrane electrode assemblies (MEAs) were successfully fabricated and good direct methanol fuel cell (DMFC) performance was observed. At 2 M MeOH feed, the current density at 0.5 V reached 165 mA/cm, which outperformed our reported similarly structured analogues and MEAs derived from comparative Nafion membranes.

  16. Dynamic water management of polymer electrolyte membrane fuel cells using intermittent RH control

    KAUST Repository

    Hussaini, I.S.

    2010-06-01

    A novel method of water management of polymer electrolyte membrane (PEM) fuel cells using intermittent humidification is presented in this study. The goal is to maintain the membrane close to full humidification, while eliminating channel flooding. The entire cycle is divided into four stages: saturation and de-saturation of the gas diffusion layer followed by de-hydration and hydration of membrane. By controlling the duration of dry and humid flows, it is shown that the cell voltage can be maintained within a narrow band. The technique is applied on experimental test cells using both plain and hydrophobic materials for the gas diffusion layer and an improvement in performance as compared to steady humidification is demonstrated. Duration of dry and humid flows is determined experimentally for several operating conditions. © 2010 Elsevier B.V. All rights reserved.

  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. Further Improvement and System Integration of High Temperature Polymer Electrolyte Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Li, Qingfeng; Jensen, Jens Oluf

    The new development in the field of polymer electrolyte membrane fuel cell (PEMFC) is high temperature PEMFC for operation above 100°C, which has been successfully demonstrated through the previous EC Joule III and the 5th framework programme. New challenges are encountered, bottlenecks for the new...... technology have been identified, and new concepts and solutions have been provisionally identified. FURIM is directed at tackling these key issues by concentrating on the further materials development, compatible technologies, and system integration of the high temperature PEMFC. The strategic developments...... of the FURIM are in three steps: (1) further improvement of the high temperature polymer membranes and related materials; (2) development of technological units including fuel cell stack, hydrocarbon reformer and afterburner, that are compatible with the HT-PEMFC; and (3) integration of the HT-PEMFC stack...

  19. Performance of polymer nano composite membrane electrode assembly using Alginate as a dopant in polymer electrolyte membrane fuel cell [Journal of Physics. Conference Series (Online), v. 795(1)

    International Nuclear Information System (INIS)

    Mulijani, S.

    2017-01-01

    Polymer membrane and composite polymer for membrane electrode assembly (MEAs) are synthesized and studied for usage in direct methanol fuel cell (DMFC). In this study, we prepared 3 type of MEAs, polystyrene (PS), sulfonated polystyrene (SPS) and composite polymer SPS-alginat membrane via catalyst hot pressed method. The performance and properties of prepared MEAs were evaluated and analyzed by impedance spectrometry and scanning electron microscopy (SEM). The result showed that, water up take of MEA composite polymer SPS-alginate was obtained higher than that in SPS and PS. The proton conductivity of MEA-SPS-alginate was also higher than that PS and PSS. SEM characterization revealed that the intimate contact between the carbon catalyst layers (CL) and the membranes, and the uniformly porous structure correlate positively with the MEAs prepared by hot pressed method, exhibiting high performances for DMFC. (paper)

  20. Synthesis and characterization of modified κ-carrageenan for enhanced proton conductivity as polymer electrolyte membrane.

    Directory of Open Access Journals (Sweden)

    Joy Wei Yi Liew

    Full Text Available Polymer electrolyte membranes based on the natural polymer κ-carrageenan were modified and characterized for application in electrochemical devices. In general, pure κ-carrageenan membranes show a low ionic conductivity. New membranes were developed by chemically modifying κ-carrageenan via phosphorylation to produce O-methylene phosphonic κ-carrageenan (OMPC, which showed enhanced membrane conductivity. The membranes were prepared by a solution casting method. The chemical structure of OMPC samples were characterized using Fourier transform infrared spectroscopy (FTIR, 1H nuclear magnetic resonance (1H NMR spectroscopy and 31P nuclear magnetic resonance (31P NMR spectroscopy. The conductivity properties of the membranes were investigated by electrochemical impedance spectroscopy (EIS. The characterization demonstrated that the membranes had been successfully produced. The ionic conductivity of κ-carrageenan and OMPC were 2.79 × 10-6 S cm-1 and 1.54 × 10-5 S cm-1, respectively. The hydrated membranes showed a two orders of magnitude higher ionic conductivity than the dried membranes.

  1. Application of the Sensor Selection Approach in Polymer Electrolyte Membrane Fuel Cell Prognostics and Health Management

    Directory of Open Access Journals (Sweden)

    Lei Mao

    2017-09-01

    Full Text Available In this paper, the sensor selection approach is investigated with the aim of using fewer sensors to provide reliable fuel cell diagnostic and prognostic results. The sensitivity of sensors is firstly calculated with a developed fuel cell model. With sensor sensitivities to different fuel cell failure modes, the available sensors can be ranked. A sensor selection algorithm is used in the analysis, which considers both sensor sensitivity to fuel cell performance and resistance to noise. The performance of the selected sensors in polymer electrolyte membrane (PEM fuel cell prognostics is also evaluated with an adaptive neuro-fuzzy inference system (ANFIS, and results show that the fuel cell voltage can be predicted with good quality using the selected sensors. Furthermore, a fuel cell test is performed to investigate the effectiveness of selected sensors in fuel cell fault diagnosis. From the results, different fuel cell states can be distinguished with good quality using the selected sensors.

  2. Carbon nanostructures as catalyst support for polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Natarajan, S.K.; Hamelin, J. [Quebec Univ., Trois Rivieres, PQ (Canada). Inst. de recherche sur l' hydrogene

    2008-07-01

    This paper reported on a study that investigated potential alternatives to Vulcan XC-72 as a catalyst supports for polymer electrolyte membrane fuel cells (PEMFCs). These included carbon nanostructures (CNS) prepared by high energy ball milling of graphite and transition metal catalysts, followed by heat treatment. Among the key factors discussed were the graphitic content, high surface area, microporous structure, good electrical conductivity and the ability of the material to attach functional groups. Some graphic results supporting the usage of CNS as catalyst support for PEMFCs were presented. Upon chemical oxidation, surface functional groups such as carbonyl, carboxyl, and hydroxyl were populated on the surface of CNS. Nanosized platinum particles with particle size distribution between 3 nm and 5 nm were reduced on the functionalized sites of CNS in a colloidal medium. The paper also presented cyclic voltammograms, XPS, HRTEM and PSD results. 3 refs.

  3. Performance of diagonal control structures at different operating conditions for polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Serra, Maria; Husar, Attila; Feroldi, Diego; Riera, Jordi [Institut de Robotica i Informatica Industrial, Universitat Politecnica de Catalunya, Consejo Superior de Investigaciones Cientificas, C. Llorens i Artigas 4, 08028 Barcelona (Spain)

    2006-08-25

    This work is focused on the selection of operating conditions in polymer electrolyte membrane fuel cells. It analyses efficiency and controllability aspects, which change from one operating point to another. Specifically, several operating points that deliver the same amount of net power are compared, and the comparison is done at different net power levels. The study is based on a complex non-linear model, which has been linearised at the selected operating points. Different linear analysis tools are applied to the linear models and results show important controllability differences between operating points. The performance of diagonal control structures with PI controllers at different operating points is also studied. A method for the tuning of the controllers is proposed and applied. The behaviour of the controlled system is simulated with the non-linear model. Conclusions indicate a possible trade-off between controllability and optimisation of hydrogen consumption. (author)

  4. Effect of time-varying humidity on the performance of a polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Noorani, Shamsuddin [Department of Mechanical Engineering, University of Michigan-Dearborn (United States); Shamim, Tariq [Mechanical Engineering, Masdar Institute of Science and Technology (United Arab Emirates)], E-mail: tshamim@masdar.ac.ae

    2011-07-01

    In the energy sector, fuel cells constitute a promising solution for the future due to their energy-efficient and environment-friendly characteristics. However, the performance of fuel cells is very much affected by the humidification level of the reactants, particularly in hot regions. The aim of this paper is to develop a better understanding of the effect of driving conditions on the performance of fuel cells. A macroscopic single-fuel-cell-based, one dimensional, isothermal model was used on a polymer electrolyte membrane fuel cell to carry out a computational study of the impact of humidity conditions which vary over time. It was found that the variation of humidity has a significant effect on water distribution but a much lower impact on power and current densities. This paper provided useful information on fuel cells' performance under varying conditions which could be used to improve their design for mobile applications.

  5. Liquid water breakthrough location distances on a gas diffusion layer of polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Yu, Junliang; Froning, Dieter; Reimer, Uwe; Lehnert, Werner

    2018-06-01

    The lattice Boltzmann method is adopted to simulate the three dimensional dynamic process of liquid water breaking through the gas diffusion layer (GDL) in the polymer electrolyte membrane fuel cell. 22 micro-structures of Toray GDL are built based on a stochastic geometry model. It is found that more than one breakthrough locations are formed randomly on the GDL surface. Breakthrough location distance (BLD) are analyzed statistically in two ways. The distribution is evaluated statistically by the Lilliefors test. It is concluded that the BLD can be described by the normal distribution with certain statistic characteristics. Information of the shortest neighbor breakthrough location distance can be the input modeling setups on the cell-scale simulations in the field of fuel cell simulation.

  6. Solid polymer electrolyte from phosphorylated chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Fauzi, Iqbal, E-mail: arcana@chem.itb.ac.id; Arcana, I Made, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Groups, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2014-03-24

    Recently, the need of secondary battery application continues to increase. The secondary battery which using a liquid electrolyte was indicated had some weakness. A solid polymer electrolyte is an alternative electrolytes membrane which developed in order to replace the liquid electrolyte type. In the present study, the effect of phosphorylation on to polymer electrolyte membrane which synthesized from chitosan and lithium perchlorate salts was investigated. The effect of the component’s composition respectively on the properties of polymer electrolyte, was carried out by analyzed of it’s characterization such as functional groups, ion conductivity, and thermal properties. The mechanical properties i.e tensile resistance and the morphology structure of membrane surface were determined. The phosphorylation processing of polymer electrolyte membrane of chitosan and lithium perchlorate was conducted by immersing with phosphoric acid for 2 hours, and then irradiated on a microwave for 60 seconds. The degree of deacetylation of chitosan derived from shrimp shells was obtained around 75.4%. Relative molecular mass of chitosan was obtained by viscometry method is 796,792 g/mol. The ionic conductivity of chitosan membrane was increase from 6.33 × 10{sup −6} S/cm up to 6.01 × 10{sup −4} S/cm after adding by 15 % solution of lithium perchlorate. After phosphorylation, the ionic conductivity of phosphorylated lithium chitosan membrane was observed 1.37 × 10{sup −3} S/cm, while the tensile resistance of 40.2 MPa with a better thermal resistance. On the strength of electrolyte membrane properties, this polymer electrolyte membrane was suggested had one potential used for polymer electrolyte in field of lithium battery applications.

  7. 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...... 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....

  8. Unraveling micro- and nanoscale degradation processes during operation of high-temperature polymer-electrolyte-membrane fuel cells

    Science.gov (United States)

    Hengge, K.; Heinzl, C.; Perchthaler, M.; Varley, D.; Lochner, T.; Scheu, C.

    2017-10-01

    The work in hand presents an electron microscopy based in-depth study of micro- and nanoscale degradation processes that take place during the operation of high-temperature polymer-electrolyte-membrane fuel cells (HT-PEMFCs). Carbon supported Pt particles were used as cathodic catalyst material and the bimetallic, carbon supported Pt/Ru system was applied as anode. As membrane, cross-linked polybenzimidazole was used. Scanning electron microscopy analysis of cross-sections of as-prepared and long-term operated membrane-electrode-assemblies revealed insight into micrometer scale degradation processes: operation-caused catalyst redistribution and thinning of the membrane and electrodes. Transmission electron microscopy investigations were performed to unravel the nanometer scale phenomena: a band of Pt and Pt/Ru nanoparticles was detected in the membrane adjacent to the cathode catalyst layer. Quantification of the elemental composition of several individual nanoparticles and the overall band area revealed that they stem from both anode and cathode catalyst layers. The results presented do not demonstrate any catastrophic failure but rather intermediate states during fuel cell operation and indications to proceed with targeted HT-PEMFC optimization.

  9. Theoretical voltammetric response of electrodes coated by solid polymer electrolyte membranes.

    Science.gov (United States)

    Gómez-Marín, Ana M; Hernández-Ortíz, Juan P

    2014-09-24

    A model for the differential capacitance of metal electrodes coated by solid polymer electrolyte membranes, with acid/base groups attached to the membrane backbone, and in contact with an electrolyte solution is developed. With proper model parameters, the model is able to predict a limit response, given by Mott-Schottky or Gouy-Chapman-Stern theories depending on the dissociation degree and the density of ionizable acid/base groups. The model is also valid for other ionic membranes with proton donor/acceptor molecules as membrane counterions. Results are discussed in light of the electron transfer rate at membrane-coated electrodes for electrochemical reactions that strongly depend on the double layer structure. In this sense, the model provides a tool towards the understanding of the electro-catalytic activity on modified electrodes. It is shown that local maxima and minima in the differential capacitance as a function of the electrode potential may occur as consequence of the dissociation of acid/base molecular species, in absence of specific adsorption of immobile polymer anions on the electrode surface. Although the model extends the conceptual framework for the interpretation of cyclic voltammograms for these systems and the general theory about electrified interfaces, structural features of real systems are more complex and so, presented results only are qualitatively compared with experiments. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Composite polymer electrolytes based on MG49 and carboxymethyl cellulose from kenaf

    International Nuclear Information System (INIS)

    Jafirin, Serawati; Ahmad, Ishak; Ahmad, Azizan

    2013-01-01

    The development of 49% poly(methyl methacrylate)-grafted natural rubber (MG49) and carboxymethyl cellulose as a composite polymer electrolyte film incorporating LiCF 3 SO 3 were explored. Carboxymethyl cellulose was synthesized from kenaf bast fibres via carboxymethylation process by alkali catalyzed reaction of cellulose with sodium chloroacetate. Reflection fourier transform infrared (ATR-FTIR) spectroscopy showed the presence of carboxyl peak after modification of cellulose with sodium chloroacetate. X-ray diffraction (XRD) analysis revealed that the crystallinity of cellulose was decrease after synthesis. High performance composite polymer electrolytes were prepared with various composition of carboxymethyl cellulose (2–10 wt%) via solution-casting method. The conductivity was increased with carboxymethyl cellulose loading. The highest conductivity value achieved was 3.3 × 10 −7 Scm −1 upon addition of 6% wt carboxymethyl cellulose. 6% wt carboxymethyl cellulose composition showed the highest tensile strength value of 7.9 MPa and 273 MPa of modulus value which demonstrated high mechanical performance with accepatable level of ionic conductivity

  11. Composite polymer electrolytes based on MG49 and carboxymethyl cellulose from kenaf

    Energy Technology Data Exchange (ETDEWEB)

    Jafirin, Serawati; Ahmad, Ishak; Ahmad, Azizan [Polymer Research Centre (PORCE), School of Chemical Science and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan (Malaysia)

    2013-11-27

    The development of 49% poly(methyl methacrylate)-grafted natural rubber (MG49) and carboxymethyl cellulose as a composite polymer electrolyte film incorporating LiCF{sub 3}SO{sub 3} were explored. Carboxymethyl cellulose was synthesized from kenaf bast fibres via carboxymethylation process by alkali catalyzed reaction of cellulose with sodium chloroacetate. Reflection fourier transform infrared (ATR-FTIR) spectroscopy showed the presence of carboxyl peak after modification of cellulose with sodium chloroacetate. X-ray diffraction (XRD) analysis revealed that the crystallinity of cellulose was decrease after synthesis. High performance composite polymer electrolytes were prepared with various composition of carboxymethyl cellulose (2–10 wt%) via solution-casting method. The conductivity was increased with carboxymethyl cellulose loading. The highest conductivity value achieved was 3.3 × 10{sup −7} Scm{sup −1} upon addition of 6% wt carboxymethyl cellulose. 6% wt carboxymethyl cellulose composition showed the highest tensile strength value of 7.9 MPa and 273 MPa of modulus value which demonstrated high mechanical performance with accepatable level of ionic conductivity.

  12. Composite polymer electrolytes based on MG49 and carboxymethyl cellulose from kenaf

    Science.gov (United States)

    Jafirin, Serawati; Ahmad, Ishak; Ahmad, Azizan

    2013-11-01

    The development of 49% poly(methyl methacrylate)-grafted natural rubber (MG49) and carboxymethyl cellulose as a composite polymer electrolyte film incorporating LiCF3SO3 were explored. Carboxymethyl cellulose was synthesized from kenaf bast fibres via carboxymethylation process by alkali catalyzed reaction of cellulose with sodium chloroacetate. Reflection fourier transform infrared (ATR-FTIR) spectroscopy showed the presence of carboxyl peak after modification of cellulose with sodium chloroacetate. X-ray diffraction (XRD) analysis revealed that the crystallinity of cellulose was decrease after synthesis. High performance composite polymer electrolytes were prepared with various composition of carboxymethyl cellulose (2-10 wt%) via solution-casting method. The conductivity was increased with carboxymethyl cellulose loading. The highest conductivity value achieved was 3.3 × 10-7 Scm-1 upon addition of 6% wt carboxymethyl cellulose. 6% wt carboxymethyl cellulose composition showed the highest tensile strength value of 7.9 MPa and 273 MPa of modulus value which demonstrated high mechanical performance with accepatable level of ionic conductivity.

  13. Introduction of functionalizable groups via radiation grafting into polymer electrolyte membranes for fuel cells

    International Nuclear Information System (INIS)

    Buchmueller, Y.; Scherer, G.G.; Wokaun, A.; Gubler, L.

    2011-01-01

    Complete text of publication follows. Our work is focused on the introduction of functionalizable groups, so called linkers, to polymer electrolyte membranes. The aim is to attach antioxidant groups to the linkers to enhance the durability of the proton conducting membrane in a fuel cell. The synthetic route we chose is radiation cografting of functionalizable monomers and precursor monomers of a protogenic group into ETFE base film (thickness 25 μm) with subsequent amination. Typically, we performed cografting of styrene with different linkers, such as acryloyl chloride, vinylbenzyl chloride, and glycidyl methacrylate. Styrene is readily sulfonated to introduce proton conductivity. The cografting behavior of the linkers and styrene was investigated to target the desired molar fraction of the monomers in the grafted polymer. All films were characterized by Fourier transform infrared (FTIR) spectroscopy and elemental analysis. Using these data the graft polymerization kinetics of these systems have been determined. The cografted films were first functionalized with amines, such as thyramine and dopamine, and then sulfonated or vice-versa, depending on the stability of the compounds in acidic environment. The synthesized membranes were characterized for conductivity and ion exchange capacity (IEC). Promising membranes were tested in a fuel cell.

  14. Further Improvement and System Integration of High Temperature Polymer Electrolyte Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Li, Qingfeng

    Polymer electrolyte membrane fuel cell (PEMFC) technology based on Nafion membranes can operate at temperatures around 80°C. The new development in the field is high temperature PEMFC for operation above 100°C, which has been successfully demonstrated through the previous EC Joule III and the 5th......, and system integration of the high temperature PEMFC. The strategic developments of the FURIM are in three steps: (1) further improvement of the high temperature polymer membranes and related materials; (2) development of technological units including fuel cell stack, hydrocarbon reformer, afterburner...... and power management system, that are compatible with the HT-PEMFC; and (3) integration of the HT-PEMFC stack with these compatible subunits. The main goal of the project is a 2kWel HT-PEMFC stack operating in a temperature range of 120-220°C, with a single cell performance target of 0.7 A/cm² at a cell...

  15. Control and experimental characterization of a methanol reformer for a 350 W high temperature polymer electrolyte membrane fuel cell system

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Sahlin, Simon Lennart

    2013-01-01

    is the water and methanol mixture fuel flow and the burner fuel/air ratio and combined flow. An experimental setup is presented capable of testing the methanol reformer used in the Serenergy H3 350 Mobile Battery Charger; a high temperature polymer electrolyte membrane (HTPEM) fuel cell system......This work presents a control strategy for controlling the methanol reformer temperature of a 350 W high temperature polymer electrolyte membrane fuel cell system, by using a cascade control structure for reliable system operation. The primary states affecting the methanol catalyst bed temperature....... The experimental system consists of a fuel evaporator utilizing the high temperature waste gas from the cathode air cooled 45 cell HTPEM fuel cell stack. The fuel cells used are BASF P1000 MEAs which use phosphoric acid doped polybenzimidazole membranes. The resulting reformate gas output of the reformer system...

  16. Amorphous metallic alloys for oxygen reduction reaction in a polymer electrolyte membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Huerta, R.; Guerra-Martinez, I.; Lopez, J.S. [Inst. Politecnico Nacional, ESIQIE, Mexico City (Mexico). Lab. de Electroquimica; Pierna, A.R. [Basque Country Univ., San Sebastian (Spain). Dept. of Chemical Engineering and Environment; Solorza-Feria, O. [Inst. Politenico Nacional, Centro de Investigacion y de Estudios Avanzados, Mexico City (Mexico). Dept. de Quimica

    2010-07-15

    Direct methanol fuel cells (DMFC) and polymer electrolyte membrane fuel cells (PEMFC) represent an important, environmentally clean energy source. This has motivated extensive research on the synthesis, characterization and evaluation of novel and stable oxygen reduction electrocatalysts for the direct four-electron transfer process to water formation. Studies have shown that amorphous alloyed compounds can be used as electrode materials in electrochemical energy conversion devices. Their use in PEMFCs can optimize the electrocatalyst loading in the membrane electrode assembly (MEA). In this study, amorphous metallic PtSn, PtRu and PtRuSn alloys were synthesized by mechanical milling and used as cathodes for the oxygen reduction reaction (ORR) in sulphuric acid and in a single PEM fuel cell. Two different powder morphologies were observed before and after the chemical activation in a hydrofluoric acid (HF) solution at 25 degrees C. The kinetics of the ORR on the amorphous catalysts were investigated. The study showed that the amorphous metallic PtSn electrocatalyst was the most active of the 3 electrodes for the cathodic reaction. Fuel cell experiments were conducted at various temperatures at 30 psi for hydrogen (H{sub 2}) and at 34 psi for oxygen (O{sub 2}). MEAs made of Nafion 115 and amorphous metallic PtSn dispersed on carbon powder in a PEMFC had a power density of 156 mW per cm{sup 2} at 0.43V and 80 degrees C. 12 refs., 1 tab., 5 figs.

  17. Current collector design for closed-plenum polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Daniels, F. A.; Attingre, C.; Kucernak, A. R.; Brett, D. J. L.

    2014-03-01

    This work presents a non-isothermal, single-phase, three-dimensional model of the effects of current collector geometry in a 5 cm2 closed-plenum polymer electrolyte membrane (PEM) fuel cell constructed using printed circuit boards (PCBs). Two geometries were considered in this study: parallel slot and circular hole designs. A computational fluid dynamics (CFD) package was used to account for species, momentum, charge and membrane water distribution within the cell for each design. The model shows that the cell can reach high current densities in the range of 0.8 A cm-2-1.2 A cm-2 at 0.45 V for both designs. The results indicate that the transport phenomena are significantly governed by the flow field plate design. A sensitivity analysis on the channel opening ratio shows that the parallel slot design with a 50% opening ratio shows the most promising performance due to better species, heat and charge distribution. Modelling and experimental analysis confirm that flooding inhibits performance, but the risk can be minimised by reducing the relative humidity of the cathode feed to 50%. Moreover, overheating is a potential problem due to the insulating effect of the PCB base layer and as such strategies should be implemented to combat its adverse effects.

  18. 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.

  19. Cross-linked Composite Gel Polymer Electrolyte using Mesoporous Methacrylate-Functionalized SiO2 Nanoparticles for Lithium-Ion Polymer Batteries

    Science.gov (United States)

    Shin, Won-Kyung; Cho, Jinhyun; Kannan, Aravindaraj G.; Lee, Yoon-Sung; Kim, Dong-Won

    2016-01-01

    Liquid electrolytes composed of lithium salt in a mixture of organic solvents have been widely used for lithium-ion batteries. However, the high flammability of the organic solvents can lead to thermal runaway and explosions if the system is accidentally subjected to a short circuit or experiences local overheating. In this work, a cross-linked composite gel polymer electrolyte was prepared and applied to lithium-ion polymer cells as a safer and more reliable electrolyte. Mesoporous SiO2 nanoparticles containing reactive methacrylate groups as cross-linking sites were synthesized and dispersed into the fibrous polyacrylonitrile membrane. They directly reacted with gel electrolyte precursors containing tri(ethylene glycol) diacrylate, resulting in the formation of a cross-linked composite gel polymer electrolyte with high ionic conductivity and favorable interfacial characteristics. The mesoporous SiO2 particles also served as HF scavengers to reduce the HF content in the electrolyte at high temperature. As a result, the cycling performance of the lithium-ion polymer cells with cross-linked composite gel polymer electrolytes employing methacrylate-functionalized mesoporous SiO2 nanoparticles was remarkably improved at elevated temperatures. PMID:27189842

  20. Theoretical voltammetric response of electrodes coated by solid polymer electrolyte membranes

    International Nuclear Information System (INIS)

    Gómez-Marín, Ana M.; Hernández-Ortíz, Juan P.

    2014-01-01

    Highlights: • Discretized model for an interface of covered electrodes. • Two limiting behaviors are capture: double-layer and conductive interfaces. • Additional phenomena are included easily: acid/base equilibrium, ion mobility. • The model provides explanations to observed phenomena that is vaguely explained in the literature. • Implications on electrodes in fuel cells are given and it opens avenues to understand and design such systems. - Abstract: A model for the differential capacitance of metal electrodes coated by solid polymer electrolyte membranes, with acid/base groups attached to the membrane backbone, and in contact with an electrolyte solution is developed. With proper model parameters, the model is able to predict a limit response, given by Mott–Schottky or Gouy–Chapman–Stern theories depending on the dissociation degree and the density of ionizable acid/base groups. The model is also valid for other ionic membranes with proton donor/acceptor molecules as membrane counterions. Results are discussed in light of the electron transfer rate at membrane-coated electrodes for electrochemical reactions that strongly depend on the double layer structure. In this sense, the model provides a tool towards the understanding of the electro-catalytic activity on modified electrodes. It is shown that local maxima and minima in the differential capacitance as a function of the electrode potential may occur as consequence of the dissociation of acid/base molecular species, in absence of specific adsorption of immobile polymer anions on the electrode surface. Although the model extends the conceptual framework for the interpretation of cyclic voltammograms for these systems and the general theory about electrified interfaces, structural features of real systems are more complex and so, presented results only are qualitatively compared with experiments

  1. UV-Induced Radical Photo-Polymerization: A Smart Tool for Preparing Polymer Electrolyte Membranes for Energy Storage Devices

    Directory of Open Access Journals (Sweden)

    Claudio Gerbaldi

    2012-06-01

    Full Text Available In the present work, the preparation and characterization of quasi-solid polymer electrolyte membranes based on methacrylic monomers and oligomers, with the addition of organic plasticizers and lithium salt, are described. Noticeable improvements in the mechanical properties by reinforcement with natural cellulose hand-sheets or nanoscale microfibrillated cellulose fibers are also demonstrated. The ionic conductivity of the various prepared membranes is very high, with average values approaching 10-3 S cm-1 at ambient temperature. The electrochemical stability window is wide (anodic breakdown voltages > 4.5 V vs. Li in all the cases along with good cyclability in lithium cells at ambient temperature. The galvanostatic cycling tests are conducted by constructing laboratory-scale lithium cells using LiFePO4 as cathode and lithium metal as anode with the selected polymer electrolyte membrane as the electrolyte separator. The results obtained demonstrate that UV induced radical photo-polymerization is a well suited method for an easy and rapid preparation of easy tunable quasi-solid polymer electrolyte membranes for energy storage devices.

  2. UV-Induced Radical Photo-Polymerization: A Smart Tool for Preparing Polymer Electrolyte Membranes for Energy Storage Devices

    Directory of Open Access Journals (Sweden)

    Claudio Gerbaldi

    2012-10-01

    Full Text Available In the present work, the preparation and characterization of quasi-solid polymer electrolyte membranes based on methacrylic monomers and oligomers, with the addition of organic plasticizers and lithium salt, are described. Noticeable improvements in the mechanical properties by reinforcement with natural cellulose hand-sheets or nanoscale microfibrillated cellulose fibers are also demonstrated. The ionic conductivity of the various prepared membranes is very high, with average values approaching 10-3 S cm-1 at ambient temperature. The electrochemical stability window is wide (anodic breakdown voltages > 4.5 V vs. Li in all the cases along with good cyclability in lithium cells at ambient temperature. The galvanostatic cycling tests are conducted by constructing laboratory-scale lithium cells using LiFePO4 as cathode and lithium metal as anode with the selected polymer electrolyte membrane as the electrolyte separator. The results obtained demonstrate that UV induced radical photo-polymerization is a well suited method for an easy and rapid preparation of easy tunable quasi-solid polymer electrolyte membranes for energy storage devices.

  3. Al2O3 Disk Supported Si3N4 Hydrogen Purification Membrane for Low Temperature Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Xiaoteng Liu

    2013-12-01

    Full Text Available Reformate gas, a commonly employed fuel for polymer electrolyte membrane fuel cells (PEMFCs, contains carbon monoxide, which poisons Pt-containing anodes in such devices. A novel, low-cost mesoporous Si3N4 selective gas separation material was tested as a hydrogen clean-up membrane to remove CO from simulated feed gas to single-cell PEMFC, employing Nafion as the polymer electrolyte membrane. Polarization and power density measurements and gas chromatography showed a clear effect of separating the CO from the gas mixture; the performance and durability of the fuel cell was thereby significantly improved.

  4. Al2O3 Disk Supported Si3N4 Hydrogen Purification Membrane for Low Temperature Polymer Electrolyte Membrane Fuel Cells.

    Science.gov (United States)

    Liu, Xiaoteng; Christensen, Paul A; Kelly, Stephen M; Rocher, Vincent; Scott, Keith

    2013-12-05

    Reformate gas, a commonly employed fuel for polymer electrolyte membrane fuel cells (PEMFCs), contains carbon monoxide, which poisons Pt-containing anodes in such devices. A novel, low-cost mesoporous Si3N4 selective gas separation material was tested as a hydrogen clean-up membrane to remove CO from simulated feed gas to single-cell PEMFC, employing Nafion as the polymer electrolyte membrane. Polarization and power density measurements and gas chromatography showed a clear effect of separating the CO from the gas mixture; the performance and durability of the fuel cell was thereby significantly improved.

  5. Novel electrospun gas diffusion layers for polymer electrolyte membrane fuel cells: Part I. Fabrication, morphological characterization, and in situ performance

    Science.gov (United States)

    Chevalier, S.; Lavielle, N.; Hatton, B. D.; Bazylak, A.

    2017-06-01

    In this first of a series of two papers, we report an in-depth analysis of the impact of the gas diffusion layer (GDL) structure on the polymer electrolyte membrane (PEM) fuel cell performance through the use of custom GDLs fabricated in-house. Hydrophobic electrospun nanofibrous gas diffusion layers (eGDLs) are fabricated with controlled fibre diameter and alignment. The eGDLs are rendered hydrophobic through direct surface functionalization, and this molecular grafting is achieved in the absence of structural alteration. The fibre diameter, chemical composition, and electrical conductivity of the eGDL are characterized, and the impact of eGDL structure on fuel cell performance is analysed. We observe that the eGDL facilitates higher fuel cell power densities compared to a commercial GDL (Toray TGP-H-60) at highly humidified operating conditions. The ohmic resistance of the fuel cell is found to significantly increase with increasing inter-fiber distance. It is also observed that the addition of a hydrophobic treatment enhances membrane hydration, and fibres perpendicularly aligned to the channel direction may enhance the contact area between the catalyst layer and the GDL.

  6. A Review of Water Management in Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Zidong Wei

    2009-11-01

    Full Text Available At present, despite the great advances in polymer electrolyte membrane fuel cell (PEMFC technology over the past two decades through intensive research and development activities, their large-scale commercialization is still hampered by their higher materials cost and lower reliability and durability. In this review, water management is given special consideration. Water management is of vital importance to achieve maximum performance and durability from PEMFCs. On the one hand, to maintain good proton conductivity, the relative humidity of inlet gases is typically held at a large value to ensure that the membrane remains fully hydrated. On the other hand, the pores of the catalyst layer (CL and the gas diffusion layer (GDL are frequently flooded by excessive liquid water, resulting in a higher mass transport resistance. Thus, a subtle equilibrium has to be maintained between membrane drying and liquid water flooding to prevent fuel cell degradation and guarantee a high performance level, which is the essential problem of water management. This paper presents a comprehensive review of the state-of-the-art studies of water management, including the experimental methods and modeling and simulation for the characterization of water management and the water management strategies. As one important aspect of water management, water flooding has been extensively studied during the last two decades. Herein, the causes, detection, effects on cell performance and mitigation strategies of water flooding are overviewed in detail. In the end of the paper the emphasis is given to: (i the delicate equilibrium of membrane drying vs. water flooding in water management; (ii determining which phenomenon is principally responsible for the deterioration of the PEMFC performance, the flooding of the porous electrode or the gas channels in the bipolar plate, and (iii what measures should be taken to prevent water flooding from happening in PEMFCs.

  7. P(AN-MMA)/TiO_2 Nano-composite Polymer Electrolyte by in-situ Polymerization

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Introduction With the development of portable electric devices,polymer lithium ion batteries (PLiBs) have been widely used as the power sources because of their high energy density and safe property[1].P(AN-MMA) copolymer is a kind of cheap macromolecules easily dissolving in the polar solvents such as carbonate,it has been applied as gel polymer electrolyte in PLiBs.Here we prepare a kind of highly conductive nano-composite polymer electrolytes using the P(AN-MMA) copolymer incorporated with TiO2 nan...

  8. Polymer electrolyte membrane water electrolysis: Restraining degradation in the presence of fluctuating power

    Science.gov (United States)

    Rakousky, Christoph; Reimer, Uwe; Wippermann, Klaus; Kuhri, Susanne; Carmo, Marcelo; Lueke, Wiebke; Stolten, Detlef

    2017-02-01

    Polymer electrolyte membrane (PEM) water electrolysis generates 'green' hydrogen when conducted with electricity from renewable - but fluctuating - sources like wind or solar photovoltaic. Unfortunately, the long-term stability of the electrolyzer performance is still not fully understood under these input power profiles. In this study, we contrast the degradation behavior of our PEM water electrolysis single cells that occurs under operation with constant and intermittent power and derive preferable operating states. For this purpose, five different current density profiles are used, of which two were constant and three dynamic. Cells operated at 1 A cm-2 show no degradation. However, degradation was observed for the remaining four profiles, all of which underwent periods of high current density (2 A cm-2). Hereby, constant operation at 2 A cm-2 led to the highest degradation rate (194 μV h-1). Degradation can be greatly reduced when the cells are operated with an intermittent profile. Current density switching has a positive effect on durability, as it causes reversible parts of degradation to recover and results in a substantially reduced degradation per mole of hydrogen produced. Two general degradation phenomena were identified, a decreased anode exchange current density and an increased contact resistance at the titanium porous transport layer (Ti-PTL).

  9. Thermal conductivity of catalyst layer of polymer electrolyte membrane fuel cells: Part 1 - Experimental study

    Science.gov (United States)

    Ahadi, Mohammad; Tam, Mickey; Saha, Madhu S.; Stumper, Jürgen; Bahrami, Majid

    2017-06-01

    In this work, a new methodology is proposed for measuring the through-plane thermal conductivity of catalyst layers (CLs) in polymer electrolyte membrane fuel cells. The proposed methodology is based on deconvolution of bulk thermal conductivity of a CL from measurements of two thicknesses of the CL, where the CLs are sandwiched in a stack made of two catalyst-coated substrates. Effects of hot-pressing, compression, measurement method, and substrate on the through-plane thermal conductivity of the CL are studied. For this purpose, different thicknesses of catalyst are coated on ethylene tetrafluoroethylene (ETFE) and aluminum (Al) substrates by a conventional Mayer bar coater and measured by scanning electron microscopy (SEM). The through-plane thermal conductivity of the CLs is measured by the well-known guarded heat flow (GHF) method as well as a recently developed transient plane source (TPS) method for thin films which modifies the original TPS thin film method. Measurements show that none of the studied factors has any effect on the through-plane thermal conductivity of the CL. GHF measurements of a non-hot-pressed CL on Al yield thermal conductivity of 0.214 ± 0.005 Wṡm-1ṡK-1, and TPS measurements of a hot-pressed CL on ETFE yield thermal conductivity of 0.218 ± 0.005 Wṡm-1ṡK-1.

  10. 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....

  11. A Quaternary Polybenzimidazole Membrane for Intermediate Temperature Polymer Electrolyte Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Xu, C.; Scott, K.; Li, Qingfeng

    2013-01-01

    at 150 °C with the PA acid loading level of 3.5 PRU (amount of H3PO4 per repeat unit of polymer QPBI). The QPBI membrane was characterized in terms of composition, structure and morphology by NMR, FTIR, SEM, and EDX. The fuel cell performance with the membrane gave peak power densities of 440 and 240 m......A quaternary ammonium polybenzimidazole (QPBI) membrane was synthesized for applications in intermediate temperature (100–200 °C) hydrogen fuel cells. The QPBI membrane was imbibed with phosphoric acid to provide suitable proton conductivity. The proton conductivity of the membrane was 0.051 S cm–1......W cm–2 using oxygen and air, respectively, at 175 °C....

  12. Performance enhancement of polymer electrolyte membrane fuel cells by dual-layered membrane electrode assembly structures with carbon nanotubes.

    Science.gov (United States)

    Jung, Dong-Won; Kim, Jun-Ho; Kim, Se-Hoon; Kim, Jun-Bom; Oh, Eun-Suok

    2013-05-01

    The effect of dual-layered membrane electrode assemblies (d-MEAs) on the performance of a polymer electrolyte membrane fuel cell (PEMFC) was investigated using the following characterization techniques: single cell performance test, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). It has been shown that the PEMFC with d-MEAs has better cell performance than that with typical mono-layered MEAs (m-MEAs). In particular, the d-MEA whose inner layer is composed of multi-walled carbon nanotubes (MWCNTs) showed the best fuel cell performance. This is due to the fact that the d-MEAs with MWCNTs have the highest electrochemical surface area and the lowest activation polarization, as observed from the CV and EIS test.

  13. Transient response of a polymer electrolyte membrane fuel cell subjected to time-varying modulating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Noorani, S.; Shamim, T. [Michigan-Dearborn Univ., Dearborn, MI (United States). Dept. of Mechanical Engineering

    2009-07-01

    In order for fuel cells to compete with internal combustion engines, they must have significant advantages in terms of overall efficiency, weight, packaging, safety and cost. A key requirement is its ability to operate under highly transient conditions during start-up, acceleration, and deceleration with stable performance. Therefore, a better understanding of fuel cell dynamic behaviour is needed along with better water management and distributions inside the cell. Therefore, this study investigated the effect of transient conditions on water distribution inside a polymer electrolyte membrane (PEM) cell. A macroscopic single-fuel cell based, one-dimensional, isothermal mathematical model was used to study the effect of modulating cell voltage on the water distribution of anode, cathode, catalyst layers, and membrane. Compared to other existing models, this model did not rely on the non-physical assumption of the uptake curve equilibrium between the pore vapour and ionomer water in the catalyst layers. Instead, the transition between the two phases was modeled as a finite-rate equilibration process. The modulating conditions were simulated by forcing the temporal variations in fuel cell voltage. The results revealed that cell voltage modulations cause a departure in the cell behaviour from its steady behaviour, and the finite-rate equilibration between the catalyst vapour and liquid water can be a factor in determining the cell response. The cell response is also affected by the modulating frequency and amplitude. The peak cell response was observed at low frequencies. Keywords: fuel cell, water transport, dynamic behaviour, numerical simulations. 9 refs., 1 tab., 5 figs.

  14. Electrospun polymer membrane activated with room temperature ionic liquid: Novel polymer electrolytes for lithium batteries

    Science.gov (United States)

    Cheruvally, Gouri; Kim, Jae-Kwang; Choi, Jae-Won; Ahn, Jou-Hyeon; Shin, Yong-Jo; Manuel, James; Raghavan, Prasanth; Kim, Ki-Won; Ahn, Hyo-Jun; Choi, Doo Seong; Song, Choong Eui

    A new class of polymer electrolytes (PEs) based on an electrospun polymer membrane incorporating a room-temperature ionic liquid (RTIL) has been prepared and evaluated for suitability in lithium cells. The electrospun poly(vinylidene fluoride- co-hexafluoropropylene) P(VdF-HFP) membrane is activated with a 0.5 M solution of LiTFSI in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMITFSI) or a 0.5 M solution of LiBF 4 in 1-butyl-3-methylimidazolium tetrafluoroborate (BMIBF 4). The resulting PEs have an ionic conductivity of 2.3 × 10 -3 S cm -1 at 25 °C and anodic stability at >4.5 V versus Li +/Li, making them suitable for practical applications in lithium cells. A Li/LiFePO 4 cell with a PE based on BMITFSI delivers high discharge capacities when evaluated at 25 °C at the 0.1 C rate (149 mAh g -1) and the 0.5 C rate (132 mAh g -1). A very stable cycle performance is also exhibited at these low current densities. The properties decrease at the higher, 1 C rate, when operated at 25 °C. Nevertheless, improved properties are obtained at a moderately elevated temperature of operation, i.e. 40 °C. This is attributed to enhanced conductivity of the electrolyte and faster reaction kinetics at higher temperatures. At 40 °C, a reversible capacity of 140 mAh g -1 is obtained at the 1 C rate.

  15. Control and experimental characterization of a methanol reformer for a 350W high temperature polymer electrolyte membrane fuel cell system

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Jensen, Hans-Christian Becker

    suited for reformer systems, where high CO tolerance is required. This enables the use fuels based on e.g. liquid alcohols. This work presents the control strategies of a methanol refoermer for a 350W HTPEM FC system. The system examined is the Serenergy H3-350 Mobile Battery Charger, an integrated......High temperature polymer electrolyte membrane(HTPEM) fuel cells offer many advantages due to their increased operating tempera-tures compared to similar Nafion-based membrane tech-nologies, that rely on the conductive abilities of liquid water. The polybenzimidazole (PBI) membranes are especially...

  16. Chemical characterization of solid polymer electrolyte membrane surfaces in LiFePO4 half-cells

    Science.gov (United States)

    Kyu, Thein; He, Ruixuan; Peng, Fang; Dunn, William E.; Kyu's Group Team, Dr.

    High temperature (60 °C) capacity retention of succinonitrile plasticized solid polymer electrolyte membrane (PEM) in a LiFePO4 half-cell was investigated with or without lithium bis(oxalato)borate (LiBOB) modification. Various symmetric cells and half-cells were studied under different thermal and electrochemical conditions. At room temperature cycling, the unmodified PEM in the half-cell appeared stable up to 50 cycles tested. Upon cycling at 60 °C, the capacity decays rapidly and concurrently the cell resistance increased. The chemical compositions of the solid PEM surfaces on both cathode and anode sides were analyzed. New IR bands (including those belonged to amide) were discerned on the unmodified PEM surface of the Li electrode side at 60 °C suggestive of side reaction, but no new bands develop during room temperature cycling. To our astonishment, the side reaction was effectively suppressed upon LiBOB addition (0.4 wt%) into the PEM, contributing to increased high temperature capacity retention at 60°C. Plausible mechanisms of capacity fading and improved cycling performance due to LiBOB modification are discussed.

  17. Fabrication of novel nanomaterials for polymer electrolyte membrane fuel cells and self-cleaning applications

    Science.gov (United States)

    Zhang, Lei

    Materials scientists have embraced nanoscale materials as allowing new degrees of freedom in materials design, as well as producing completely new and enhanced properties compared with conventional materials. However, most nanofabrication methods are tedious and expensive, or require extreme conditions. This thesis presents efficient methods for generating nanostructured materials under relatively mild chemistry and experimental conditions. The basis of most of this work is porous anodic aluminum oxide (p-AAO) membranes, which have hexagonally close-packed pores and were fabricated following a two-step aluminum anodization procedure. Partially removing the barrier layer of a p-AAO membrane enabled the preparation of silver nanorod arrays using a very simple electrodepostition procedure. One dimensional (1-D) alumina nanostructures were also electrochemically synthesized on the surface of a p-AAO membrane by carefully controlling the anodization parameters. Polyacrylonitrile nanofibers containing platinum salt were fabricated by polymerization of acrylonitrile in p-AAO templates. Subsequent pyrolysis resulted in carbon nanofibers wherein the platinum salt is reduced in-situ to elemental Pt. The Pt nanoparticles are dispersed throughout the carbon nanofibers, have a narrow size range, and are single crystals. Rotating disc electrode voltammetry suggests that the dispersion of Pt nanocrystals in the carbon nanofiber matrix should exhibit excellent electrocatalytic activity. The preparation of catalyst ink and the construction of membrane-electrode-assembly need to be optimized to get better performance in polymer electrolyte membrane fuel cells. Platinum nanoparticles embedded in carbon fibers were also prepared using electrospinning. The prepared platinum nanoparticles are narrowly distributed in size and well dispersed in the carbon matrix. This method can provide a large yield of products with a simple setup and procedure. 2-D arrays of nanopillars made from

  18. Experimental elucidation on rate-determining process of water transport in polymer electrolyte fuel cell membrane by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Takita, Shinpei; Tsushima, Shohji; Hirai, Shuichiro; Kubo, Norio; Aotani, Koichiro

    2007-01-01

    We examined rate-determining process of water transport in polymer electrolyte membrane (PEM) used in fuel cells by using magnetic resonance imaging (MRI). We measured transversal water content distributions of the membrane by MRI and through-plane mass flux of water by hygrometers. Through place water flux has taken place in the membrane when relative humidify of supplied gas is not equal in both side of the membrane. MRI results revealed that diffusion coefficient of water in the membrane increases with water content of membrane, λ, whilst it shows intensive peak at λ=3-4. Diffusion resistance and mass transfer resistance involving evaporation and condensation on the interface are almost in the same order and thus water transport process in the membrane is determined by either concentration diffusion or mass transfer, depending on water content of membrane. (author)

  19. Study of Ion Transport Behaviour in (PVA-NH4I):SIO2 Nano Composite Polymer Electrolyte

    Science.gov (United States)

    Tripathi, Mridula; Trivedi, Shivangi; Upadhyay, Ruby; Singh, Markandey; Pandey, N. D.; Pandey, Kamlesh

    2013-07-01

    Development and characterization of Poly vinyl alcohol (PVA) based nano composite polymer electrolytes comprising of (PVA-NH4I):SiO2 is reported. Sol-gel derived silica powder of nano dimension has been used as ceramic filler for development of nano composite electrolyte. Formation of nano composites, change in the structural and microscopic properties of the system have been investigated by X-ray differaction, SEM and conductivity.

  20. Effects of the operational conditions on the membrane and electrode properties of a polymer electrolyte fuel cell

    Directory of Open Access Journals (Sweden)

    Passos Raimundo R.

    2002-01-01

    Full Text Available The effects of the operational conditions on the membrane and electrode properties on a polymer electrolyte fuel cell (PEFC were investigated as a function of the cell and the gas humidifiers temperatures, the thickness of the membrane, the impregnation with phosphotungstic acid (PWA, and the variation of the Nafion and Teflon contents in the gas diffusion electrodes. An increase of the membrane resistance was observed when the PEFC is operated at temperatures equal or higher than those of the gas humidifiers, and this is more apparent for thicker electrolyte films. In the presence of PWA, the physicochemical properties of the membrane do not appreciably change with temperature. However, in this case, a lower humidification temperature affects the electrode performance. Changes on the Nafion loading in the electrodes do not lead to any significant effect in the electrode and membrane properties. For high Teflon contents there is a small lowering of the membrane conductivity.

  1. Energy storage in structural composites by introducing CNT fiber/polymer electrolyte interleaves.

    Science.gov (United States)

    Senokos, Evgeny; Ou, Yunfu; Torres, Juan Jose; Sket, Federico; González, Carlos; Marcilla, Rebeca; Vilatela, Juan J

    2018-02-21

    This work presents a method to produce structural composites capable of energy storage. They are produced by integrating thin sandwich structures of CNT fiber veils and an ionic liquid-based polymer electrolyte between carbon fiber plies, followed by infusion and curing of an epoxy resin. The resulting structure behaves simultaneously as an electric double-layer capacitor and a structural composite, with flexural modulus of 60 GPa and flexural strength of 153 MPa, combined with 88 mF/g of specific capacitance and the highest power (30 W/kg) and energy (37.5 mWh/kg) densities reported so far for structural supercapacitors. In-situ electrochemical measurements during 4-point bending show that electrochemical performance is retained up to fracture, with minor changes in equivalent series resistance for interleaves under compressive stress. En route to improving interlaminar properties we produce grid-shaped interleaves that enable mechanical interconnection of plies by the stiff epoxy. Synchrotron 3D X-ray tomography analysis of the resulting hierarchical structure confirms the formation of interlaminar epoxy joints. The manuscript discusses encapsulation role of epoxy, demonstrated by charge-discharge measurements of composites immersed in water, a deleterious agent for ionic liquids. Finally, we show different architectures free of current collector and electrical insulators, in which both CNT fiber and CF act as active electrodes.

  2. Rapid fabrication of microfluidic polymer electrolyte membrane fuel cell in PDMS by surface patterning of perfluorinated ion-exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yong-Ak; Han, Jongyoon [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States); Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States); Batista, Candy [Roxbury Community College, 1234 Columbus Ave., Roxbury Crossing, MA 02120 (United States); Sarpeshkar, Rahul [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States)

    2008-09-01

    In this paper we demonstrate a simple and rapid fabrication method for a microfluidic polymer electrolyte membrane (PEM) fuel cell using polydimethylsiloxane (PDMS), which has become the de facto standard material in BioMEMS. Instead of integrating a Nafion sheet film between two layers of a PDMS device in a traditional ''sandwich format,'' we pattern a perfluorinated ion-exchange resin such as a Nafion resin on a glass substrate using a reversibly bonded PDMS microchannel to generate an ion-selective membrane between the fuel-cell electrodes. After this patterning step, the assembly of the microfluidic fuel cell is accomplished by simple oxygen plasma bonding between the PDMS chip and the glass substrate. In an example implementation, the planar PEM microfluidic fuel cell generates an open circuit voltage of 600-800 mV and delivers a maximum current output of nearly 4 {mu}A. To enhance the power output of the fuel cell we utilize self-assembled colloidal arrays as a support matrix for the Nafion resin. Such arrays allow us to increase the thickness of the ion-selective membrane to 20 {mu}m and increase the current output by 166%. Our novel fabrication method enables rapid prototyping of microfluidic fuel cells to study various ion-exchange resins for the polymer electrolyte membrane. Our work will facilitate the development of miniature, implantable, on-chip power sources for biomedical applications. (author)

  3. Development of real-time measurement of methanol-concentration in polymer electrolyte membrane using a local NMR sensor

    International Nuclear Information System (INIS)

    Ogawa, Kuniyasu; Ito, Kohei; Haishi, Tomoyuki

    2007-01-01

    A real-time sensor to measure methanol concentration in polymer electrolyte membrane (PEM) was developed for reducing methanol cross-over in Direct Methanol Fuel Cell (DMFC). The principle of the methanol sensor is based on the chemical shift of CH and OH species under high magnetic field. The sensor consists of a planar surface coil of 1.3 mm outside diameter. NMR signal from PEM being exposed to CH3OH solvent was measured using NMR sensor. Time-dependence changes of methanol concentration in PEM were obtained from analyzing spectrum of NMR signal. (author)

  4. Cyclic voltammetric investigations of microstructured and platinum-covered glassy carbon electrodes in contact with a polymer electrolyte membrane

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, G G; Veziridis, Z; Staub, M [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Freimuth, H [Inst. fuer Mikrotechnik Mainz IMM, Mainz (Germany)

    1997-06-01

    Model gas diffusion electrodes were prepared by microstructuring glassy carbon surfaces with high aspect ratios and subsequent deposition of platinum. These electrodes were characterized by hydrogen under-potential deposition (H-upd) in contact with a polymer electrolyte membrane employing cyclic voltametry. H-upd was found on platinum areas not in direct contact to the solid electrolyte, as long as a continuous platinum-path existed. A carbon surface between platinum acts as barrier for H-upd. (author) 4 figs., 5 refs.

  5. 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.

  6. Enhancing the Chemical and Mechanical Durability of Polymer Electrolyte Membranes for Fuel Cell Applications

    Science.gov (United States)

    Baker, Andrew M.

    Polymer electrolyte membrane (PEM) fuel cells are energy conversion devices which generate electricity from the electrochemical reaction of hydrogen and oxygen. Currently, widespread adoption of PEM fuel cell technology is hindered by low component durability and high costs. In this work, strategies were investigated to improve the mechanical and chemical durability of the ion conducting polymer, or ionomer, which comprises the PEM, in order to directly address these limitations. Owing to their exceptional mechanical properties, carbon nanotubes (CNTs) were investigated for mechanical reinforcement of the PEM. Because of their electronic conductivity, which diminishes cell performance, two strategies were developed to enable the use of CNTs as PEM reinforcement. These systems result in enhanced mechanical properties without sacrificing performance of the PEM during operation. Further, when coated with ceria (CeO2), which scavenges radicals that are generated during operation and cause PEM chemical degradation by attacking vulnerable chemical groups in the ionomer, MWCNTs further improved PEM chemical durability. During cell fabrication, conditioning, and discharge, Ce rapidly migrates between the PEM and catalyst layers (CLs), which reduces catalyst efficiency and leaves areas of the cell defenseless against radical attacks. Therefore, in order to stabilize Ce and localize it to areas of highest radical generation, it is critical to understand and identify the relative influences of different migration mechanisms. Using a novel elemental analysis technique, Ce migration was characterized due to potential and concentration gradients, water flux, and degradation of Ce-exchanged sulfonic acid groups within the PEM. Additionally, Zr-doped ceria was employed to resist migration due to ionomer degradation which improved cell durability, without reducing performance, resulting in PEM Ce stabilization near its initial concentrations after > 1,400 hours of testing. Ce was

  7. Density functional theory calculations of H/D isotope effects on polymer electrolyte membrane fuel cell operations

    Energy Technology Data Exchange (ETDEWEB)

    Yanase, Satoshi; Oi, Takao [Sophia Univ., Tokyo (Japan). Faculty of Science and Technology

    2015-10-01

    To elucidate hydrogen isotope effects observed between fuel and exhaust hydrogen gases during polymer electrolyte membrane fuel cell operations, H-to-D reduced partition function ratios (RPFRs) for the hydrogen species in the Pt catalyst phase of the anode and the electrolyte membrane phase of the fuel cell were evaluated by density functional theory calculations on model species of the two phases. The evaluation yielded 3.2365 as the value of the equilibrium constant of the hydrogen isotope exchange reaction between the two phases at 39 C, which was close to the experimentally estimated value of 3.46-3.99 at the same temperature. It was indicated that H{sup +} ions on the Pt catalyst surface of the anode and H species in the electrolyte membrane phase were isotopically in equilibrium with one another during fuel cell operations.

  8. Development and Application of a Sample Holder for In Situ Gaseous TEM Studies of Membrane Electrode Assemblies for Polymer Electrolyte Fuel Cells.

    Science.gov (United States)

    Kamino, Takeo; Yaguchi, Toshie; Shimizu, Takahiro

    2017-10-01

    Polymer electrolyte fuel cells hold great potential for stationary and mobile applications due to high power density and low operating temperature. However, the structural changes during electrochemical reactions are not well understood. In this article, we detail the development of the sample holder equipped with gas injectors and electric conductors and its application to a membrane electrode assembly of a polymer electrolyte fuel cell. Hydrogen and oxygen gases were simultaneously sprayed on the surfaces of the anode and cathode catalysts of the membrane electrode assembly sample, respectively, and observation of the structural changes in the catalysts were simultaneously carried out along with measurement of the generated voltages.

  9. Proton transport in additives to the polymer electrolyte membrane for fuel cell application

    Energy Technology Data Exchange (ETDEWEB)

    Toelle, Pia

    2011-03-21

    The enhancement of proton transport in polymer electrolyte membranes is an important issue for the development of fuel cell technology. The objective is a material providing proton transport at a temperature range of 350 K to 450 K independent from a purely water based mechanism. To enhance the PEM properties of standard polymer materials, a class of additives is studied by means of atomistic simulations consisting of functionalised mesoporous silicon dioxide particles. The functional molecules are imidazole or sulphonic acid, covalently bound to the surface via a carbon chain with a surface density of about 1.0 nm{sup -2} groups. At first, the proton transport mechanism is explored in a system of functional molecules in vacuum. The molecules are constrained by the terminal carbon groups according to the geometric arrangement in the porous silicon dioxide. The proton transport mechanism is characterised by structural properties obtained from classical molecular dynamics simulations and consists of the aggregation of two or more functional groups, a barrier free proton transport between these groups followed by the separation of the groups and formation of new aggregates due to fluctuations in the hydrogen bond network and movement of the carbon chain. For the different proton conducting groups, i.e. methyl imidazole, methyl sulphonic acid and water, the barrier free proton transport and the formation of protonated bimolecular complexes were addressed by potential energy calculations of the density functional based tight binding method (DFTB). For sulphonic acid even at a temperature of 450 K, relatively stable aggregates are formed, while most imidazole groups are isolated and the hydrogen bond fluctuations are high. However, high density of groups and elevated temperatures enhance the proton transport in both systems. Besides the anchorage and the density of the groups, the influence of the chemical environment on the proton transport was studied. Therefore, the

  10. A UV-prepared linear polymer electrolyte membrane for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Imperiyka, M., E-mail: imperiyka@gmail.com [Faculty of Arts and Sciences, Kufra Campus, University of Benghazi, Al Kufrah (Libya); Ahmad, A.; Hanifah, S.A. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Polymer Research Center, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Bella, F. [Center for Space Human Robotics @Polito, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Department of Applied Science and Technology – DISAT, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2014-10-01

    The effects of LiClO{sub 4} and LiFS{sub 3}SO{sub 3} on poly(glycidyl methacrylate)-based solid polymer electrolyte and its photoelectrochemical performance in a dye sensitized solar cell consisting of FTO/TiO{sub 2}–dye/P(GMA)–LiClO{sub 4}–EC/Pt were investigated. The electrochemical stability of films was studied by cyclic voltammetry (CV). The highest ionic conductivities obtained were 4.2×10{sup −5} and 3.7×10{sup −6} S cm{sup −1} for the film containing 30 wt% LiClO{sub 4} and 25 wt% LiCF{sub 3}SO{sub 3}, respectively. The polymer electrolytes showed electrochemical stability windows up to 3 V and 2.8 V for LiClO{sub 4} and LiCF{sub 3}SO{sub 3}, respectively. The assembled dye-sensitized solar cell showed a sunlight conversion efficiency of 0.679% (J{sub sc}=3 mA cm{sup −2}, V{sub oc}=0.48 V and FF=0.47), under light intensity of 100 mW cm{sup −2}.

  11. 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

  12. Polybenzimidazole Membranes Containing Benzimidazole Side Groups for High Temprature Polymer Electrolyte Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Yang, Jingshuai; Li, Xueyuan; Xu, Yizin

    2013-01-01

    Polybenzimidazole (PBI) with a high molecular weight of 69,000 was first synthesized. It was afterwards grafted with benzimidazole pendant groups on the backbones. The acid doped benzimidaozle grafted PBI membranes were investigated and characterized including fuel cell tests at elevated temperat......Polybenzimidazole (PBI) with a high molecular weight of 69,000 was first synthesized. It was afterwards grafted with benzimidazole pendant groups on the backbones. The acid doped benzimidaozle grafted PBI membranes were investigated and characterized including fuel cell tests at elevated...... temperatures without humidification. At an acid doping level of 13.1 mol H3PO4 per average molar repeat unit, the PBI membranes with a benzimidazole grafting degree of 10.6% demonstrated a conductivity of 0.15 S cm-1 and a H2-air fuel cell peak power density of 378 mW cm-2 at 180 oC at ambient pressure without...

  13. U.S. DOE Progress Towards Developing Low-Cost, High Performance, Durable Polymer Electrolyte Membranes for Fuel Cell Applications.

    Science.gov (United States)

    Houchins, Cassidy; Kleen, Greg J; Spendelow, Jacob S; Kopasz, John; Peterson, David; Garland, Nancy L; Ho, Donna Lee; Marcinkoski, Jason; Martin, Kathi Epping; Tyler, Reginald; Papageorgopoulos, Dimitrios C

    2012-12-18

    Low cost, durable, and selective membranes with high ionic conductivity are a priority need for wide-spread adoption of polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). Electrolyte membranes are a major cost component of PEMFC stacks at low production volumes. PEMFC membranes also impose limitations on fuel cell system operating conditions that add system complexity and cost. Reactant gas and fuel permeation through the membrane leads to decreased fuel cell performance, loss of efficiency, and reduced durability in both PEMFCs and DMFCs. To address these challenges, the U.S. Department of Energy (DOE) Fuel Cell Technologies Program, in the Office of Energy Efficiency and Renewable Energy, supports research and development aimed at improving ion exchange membranes for fuel cells. For PEMFCs, efforts are primarily focused on developing materials for higher temperature operation (up to 120 °C) in automotive applications. For DMFCs, efforts are focused on developing membranes with reduced methanol permeability. In this paper, the recently revised DOE membrane targets, strategies, and highlights of DOE-funded projects to develop new, inexpensive membranes that have good performance in hot and dry conditions (PEMFC) and that reduce methanol crossover (DMFC) will be discussed.

  14. U.S. DOE Progress Towards Developing Low-Cost, High Performance, Durable Polymer Electrolyte Membranes for Fuel Cell Applications

    Directory of Open Access Journals (Sweden)

    Dimitrios C. Papageorgopoulos

    2012-12-01

    Full Text Available Low cost, durable, and selective membranes with high ionic conductivity are a priority need for wide-spread adoption of polymer electrolyte membrane fuel cells (PEMFCs and direct methanol fuel cells (DMFCs. Electrolyte membranes are a major cost component of PEMFC stacks at low production volumes. PEMFC membranes also impose limitations on fuel cell system operating conditions that add system complexity and cost. Reactant gas and fuel permeation through the membrane leads to decreased fuel cell performance, loss of efficiency, and reduced durability in both PEMFCs and DMFCs. To address these challenges, the U.S. Department of Energy (DOE Fuel Cell Technologies Program, in the Office of Energy Efficiency and Renewable Energy, supports research and development aimed at improving ion exchange membranes for fuel cells. For PEMFCs, efforts are primarily focused on developing materials for higher temperature operation (up to 120 °C in automotive applications. For DMFCs, efforts are focused on developing membranes with reduced methanol permeability. In this paper, the recently revised DOE membrane targets, strategies, and highlights of DOE-funded projects to develop new, inexpensive membranes that have good performance in hot and dry conditions (PEMFC and that reduce methanol crossover (DMFC will be discussed.

  15. Determination of membrane degradation products in the product water of polymer electrolyte membrane fuel cells using liquid chromatography mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zedda, Marco

    2011-05-12

    The predominant long term failure of polymer electrolyte membranes (PEM) is caused by hydroxyl radicals generated during fuel cell operation. These radicals attack the polymer, leading to chain scission, unzipping and consequently to membrane decomposition products. The present work has investigated decomposition products of novel sulfonated aromatic hydrocarbon membranes on the basis of a product water analysis. Degradation products from the investigated membrane type and the possibility to detect these compounds in the product water for diagnostic purposes have not been discovered yet. This thesis demonstrates the potential of solid phase extraction and liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) for the extraction, separation, characterization, identification and quantification of membrane degradation products in the product water of fuel cells. For this purpose, several polar aromatic hydrocarbons with different functional groups were selected as model compounds for the development of reliable extraction, separation and detection methods. The results of this thesis have shown that mixed mode sorbent materials with both weak anion exchange and reversed phase retention properties are well suited for reproducible extraction of both molecules and ions from the product water. The chromatographic separation of various polar aromatic hydrocarbons was achieved by means of phase optimized liquid chromatography using a solvent gradient and on a C18 stationary phase. Sensitive and selective detection of model compounds could be successfully demonstrated by the analysis of the product water using tandem mass spectrometry. The application of a hybrid mass spectrometer (Q Trap) for the characterization of unknown polar aromatic hydrocarbons has led to the identification and confirmation of 4-hydroxybenzoic acid in the product water. In addition, 4-HBA could be verified as a degradation product resulting from PEM decomposition by hydroxyl radicals using an

  16. An experimental and simulation study of novel channel designs for open-cathode high-temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Thomas, Sobi; Bates, Alex; Park, Sam

    2016-01-01

    A minimum balance of plant (BOP) is desired for an open-cathode high temperature polymer electrolyte membrane (HTPEM) fuel cell to ensure low parasitic losses and a compact design. The advantage of an open-cathode system is the elimination of the coolant plate and incorporation of a blower for ox...

  17. Effect of process parameters on the dynamic behavior of polymer electrolyte membrane fuel cells for electric vehicle applications

    Directory of Open Access Journals (Sweden)

    A.A. Abd El Monem

    2014-03-01

    Full Text Available This paper presents a dynamic mathematical model for Polymer Electrolyte Membrane “PEM” fuel cell systems to be used for electric vehicle applications. The performance of the fuel cell, depending on the developed model and taking the double layer charging effect into account, is investigated with different process parameters to evaluate their effect on the unit behavior. Thus, it will be easy to develop suitable controllers to regulate the unit operation, which encourages the use of fuel cells especially with electric vehicles applications. The steady-state performance of the fuel cell is verified using a comparison with datasheet data and curves provided by the manufacturer. The results and conclusions introduced in this paper provide a base for further investigation of fuel cells-driven dc motors for electric vehicle.

  18. In situ liquid water visualization in polymer electrolyte membrane fuel cells with high resolution synchrotron x-ray radiography

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier, S.; Banerjee, R.; Lee, J.; Ge, N.; Lee, C.; Bazylak, A., E-mail: abazylak@mie.utoronto.ca [Dept. of Mechanical & Industrial Engineering, Faculty of Applied Science & Engineering, University of Toronto, Toronto, Ontario (Canada); Wysokinski, T. W.; Belev, G.; Webb, A.; Miller, D.; Zhu, N. [Canadian Light Source, Saskatoon, Saskatchewan (Canada); Tabuchi, Y.; Kotaka, T. [EV System Laboratory, Research Division 2, Nissan Motor Co., Ltd., Yokosuka, Kanagawa (Japan)

    2016-07-27

    In this work, we investigated the dominating properties of the porous materials that impact water dynamics in a polymer electrolyte membrane fuel cell (PEMFC). Visualizations of liquid water in an operating PEMFC were performed at the Canadian Light Source. A miniature fuel cell was specifically designed for X-ray imaging investigations, and an in-house image processing algorithm based on the Beer-Lambert law was developed to extract quantities of liquid water thicknesses (cm) from raw X-ray radiographs. The X-ray attenuation coefficient of water at 24 keV was measured with a calibration device to ensure accurate measurements of the liquid water thicknesses. From this experiment, the through plane distribution of the liquid water in the fuel cell was obtained.

  19. In situ liquid water visualization in polymer electrolyte membrane fuel cells with high resolution synchrotron x-ray radiography

    International Nuclear Information System (INIS)

    Chevalier, S.; Banerjee, R.; Lee, J.; Ge, N.; Lee, C.; Bazylak, A.; Wysokinski, T. W.; Belev, G.; Webb, A.; Miller, D.; Zhu, N.; Tabuchi, Y.; Kotaka, T.

    2016-01-01

    In this work, we investigated the dominating properties of the porous materials that impact water dynamics in a polymer electrolyte membrane fuel cell (PEMFC). Visualizations of liquid water in an operating PEMFC were performed at the Canadian Light Source. A miniature fuel cell was specifically designed for X-ray imaging investigations, and an in-house image processing algorithm based on the Beer-Lambert law was developed to extract quantities of liquid water thicknesses (cm) from raw X-ray radiographs. The X-ray attenuation coefficient of water at 24 keV was measured with a calibration device to ensure accurate measurements of the liquid water thicknesses. From this experiment, the through plane distribution of the liquid water in the fuel cell was obtained.

  20. Evaluation of the effect of reactant gases mass flow rates on power density in a polymer electrolyte membrane fuel cell

    Science.gov (United States)

    Kahveci, E. E.; Taymaz, I.

    2018-03-01

    In this study it was experimentally investigated the effect of mass flow rates of reactant gases which is one of the most important operational parameters of polymer electrolyte membrane (PEM) fuel cell on power density. The channel type is serpentine and single PEM fuel cell has an active area of 25 cm2. Design-Expert 8.0 (trial version) was used with four variables to investigate the effect of variables on the response using. Cell temperature, hydrogen mass flow rate, oxygen mass flow rate and humidification temperature were selected as independent variables. In addition, the power density was used as response to determine the combined effects of these variables. It was kept constant cell and humidification temperatures while changing mass flow rates of reactant gases. From the results an increase occurred in power density with increasing the hydrogen flow rates. But oxygen flow rate does not have a significant effect on power density within determined mass flow rates.

  1. Development of nano-structure controlled polymer electrolyte fuel-cell membranes by high-energy heavy ion irradiation

    International Nuclear Information System (INIS)

    Yamaki, Tetsuya; Asano, Masaharu; Maekawa, Yasunari; Yoshida, Masaru; Kobayashi, Misaki; Nomura, Kumiko; Takagi, Shigeharu

    2008-01-01

    There is increasing interest in polymer electrolyte fuel cells (PEFCs) together with recent worldwide energy demand and environmental issues. In order to develop proton-conductive membranes for PEFCs, we have been using high-energy heavy ion beams from the cyclotron accelerator of Takasaki Ion Accelerators for Advanced Radiation Application (TIARA), JAEA. Our strategic focus is centered on using nano-scale controllability of the ion-beam processing; the membrane preparation involves (1) the irradiation of commercially-available base polymer films with MeV ions, (2) graft polymerization of vinyl monomers into electronically-excited parts along the ion trajectory, called latent tracks, and (3) sulfonation of the graft polymers. Interestingly, the resulting membranes exhibited anisotropic proton transport, i.e., higher conductivity in the thickness direction. According to microscopic observations, this is probably because the columnar electrolyte phase extended, with a width of tens-to-hundreds nanometers, through the membrane. Other excellent membrane properties, e.g., sufficient mechanical strength, high dimensional stability, and low gas permeability should be due to such a controlled structure. (author)

  2. 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.

  3. Carboxymethyl Cellulose From Kenaf Reinforced Composite Polymer Electrolytes Based 49 % Poly (Methyl Methacrylate)-Grafted Natural Rubber

    International Nuclear Information System (INIS)

    Serawati Jafirin; Ishak Ahmad; Azizan Ahmad; Ishak Ahmad; Azizan Ahmad

    2014-01-01

    Composite polymer electrolytes based 49 % poly(methyl methacrylate)-grafted natural rubber (MG49) incorporating lithium triflate (LiCF 3 SO 3 ) were prepared. The study mainly focuses on the ionic conductivity performances and mechanical properties. Prior to that, carboxymethyl cellulose was synthesized from kenaf fiber. The films were characterized by electrochemical impedance (EIS) spectroscopy, linear sweep voltammetry (LSV), universal testing machine and scanning electron microscopy (SEM). The conductivity was found to increase with carboxymethyl cellulose loading. The highest conductivity value achieved was 6.5 x 10 -6 Scm -1 upon addition of 6 wt % carboxymethyl cellulose. LSV graph shows the stability of this film was extended to 2.7 V at room temperature. The composition with 6 wt % carboxymethyl cellulose composition showed the highest tensile strength value of 7.9 MPa and 273 MPa of Young's modulus. The morphology of the electrolytes showed a smooth surface of films after addition of salt and filler indicating amorphous phase in electrolytes system. Excellent mechanical properties and good ionic conductivity are obtained, enlightening that the film is suitable for future applications as thin solid polymer electrolytes in lithium batteries. (author)

  4. Effect of sulphuric acid concentration on electroosmotic flow through polymer electrolyte membranes in PEM fuel cells. Paper no. IGEC-1-061

    International Nuclear Information System (INIS)

    Karimi, G.; Li, X.

    2005-01-01

    Polymer electrolyte membrane (PEM) fuel cells are highly efficient and environmentally clean, and hence one of the most promising power sources for both stationary and mobile applications. The operations of PEM fuel cells are complicated by the electroosmotic flow of water from anode to cathode through the polymer electrolyte membrane leading to the membrane dehydration and fuel cell performance degradations. In this study, electro osmotic flow in polymer electrolyte membranes is modeled by incorporating the electro kinetic effects in the presence of euphoric acid. The governing Poisson-Boatman and the Nervier-Stokes equations were solved numerically for a single membrane pore to determine the electro osmotic flow distributions through the membrane over a wide range of acid concentrations. The presence of euphoric acid modifies the protons distribution in the membrane and hence alters the driving force for electroosmotic drag. Numerical results indicate that the electro osmotic flow increases steadily with acid concentration. The water transport due to electro osmosis is almost doubled at 2 M acid concentration compared with that of non-doped membrane. The value of electroosmotic drag coefficient however falls steadily with acid concentration due to the presence of a larger number of protons in the electrolyte. (author)

  5. High-performance membrane-electrode assembly with an optimal polytetrafluoroethylene content for high-temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Jeong, Gisu; Kim, MinJoong; Han, Junyoung

    2016-01-01

    Although high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) have a high carbon monoxide tolerance and allow for efficient water management, their practical applications are limited due to their lower performance than conventional low-temperature PEMFCs. Herein, we present a high......-performance membrane-electrode assembly (MEA) with an optimal polytetrafluoroethylene (PTFE) content for HT-PEMFCs. Low or excess PTFE content in the electrode leads to an inefficient electrolyte distribution or severe catalyst agglomeration, respectively, which hinder the formation of triple phase boundaries...

  6. Effects of heat and water transport on the performance of polymer electrolyte membrane fuel cell under high current density operation

    International Nuclear Information System (INIS)

    Tabuchi, Yuichiro; Shiomi, Takeshi; Aoki, Osamu; Kubo, Norio; Shinohara, Kazuhiko

    2010-01-01

    Key challenges to the acceptance of polymer electrolyte membrane fuel cells (PEMFCs) for automobiles are the cost reduction and improvement in its power density for compactness. In order to get the solution, the further improvement in a fuel cell performance is required. In particular, under higher current density operation, water and heat transport in PEMFCs has considerable effects on the cell performance. In this study, the impact of heat and water transport on the cell performance under high current density was investigated by experimental evaluation of liquid water distribution and numerical validation. Liquid water distribution in MEA between rib and channel area is evaluated by neutron radiography. In order to neglect the effect of liquid water in gas channels and reactant species concentration distribution in the flow direction, the differential cell was used in this study. Experimental results suggested that liquid water under the channel was dramatically changed with rib/channel width. From the numerical study, it is found that the change of liquid water distribution was significantly affected by temperature distribution in MEA between rib and channel area. In addition, not only heat transport but also water transport through the membrane also significantly affected the cell performance under high current density operation.

  7. FTIR Spectroscopic and DC Ionic conductivity Studies of PVDF-HFP: LiBF4: EC Plasticized Polymer Electrolyte Membrane

    Science.gov (United States)

    Sangeetha, M.; Mallikarjun, A.; Jaipal Reddy, M.; Siva Kumar, J.

    2017-08-01

    In the present paper; the FTIR and Temperature dependent DC Ionic conductivity studies of polymer (80 Wt% PVDF-HFP) with inorganic lithium tetra fluoroborate salt (20 Wt% LiBF4) as ionic charge carrier and plasticized with various weight ratios of Ethylene carbonate plasticizer (10 Wt% to 70 Wt% EC) as gel polymer electrolytes. Solution casting method is used for the preparation of plasticized polymer-salt electrolyte films. FTIR analysis shows the good complexation between PVDF-HFP: LiBF4 and the presence of functional groups in the plasticized polymer-salt electrolyte membrane. Also the analysis and results show that the highest DC ionic conductivity of 1.66 × 10-3 SCm -1 was found at 373 K for a particular concentration of 80 Wt% PVDF-HFP: 20 Wt% LiBF4: 40 Wt% EC porous gel type polymer-salt plasticized porous membrane. Increase of temperature results expansion and segmental motion of polymer chain that generates free volume in turn promotes hopping of the lithium ions satisfying Vogel-Tammann-Fulcher equation.

  8. Dual control of low concentration CO poisoning by anode air bleeding of low temperature polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Klages, Merle; Tjønnås, Johannes; Zenith, Federico; Halvorsen, Ivar J.; Scholta, Joachim

    2016-12-01

    Fuel impurities, fed to a polymer electrolyte membrane fuel cell, can affect stack performance by poisoning of catalyst layers. This paper describes the dynamic behaviour of a stack, including state-of-the-art membrane electrode assemblies (MEA) of three different manufacturers, at different operating conditions. The voltage transients of the step responses to CO poisoning as well as air bleed recovery are compared, revealing differences in performance loss: slow poisoning versus fast recovery, incomplete recovery and voltage oscillation. The recorded behaviour is used to develop a model, based on Tafel equation and first order dynamic response, which can be calibrated to each MEA type. Using this model to predict voltage response, a controller is built with the aim of reducing the total amount of air bleed and monitoring upstream stack processes without the need of sensors measuring the poisoning level. Two controllers are implemented in order to show the concept from a heuristic, easy to implement, and a more technical side allowing more detailed analysis of the synthesis. The heuristic algorithm, based on periodic perturbations of the manipulated variable (air-bleed), is validated on a real stack, revealing a stabilized performance without the need of detailed stack properties knowledge.

  9. Effects of Silica Nanostructures in Poly(ethylene oxide)-Based Composite Polymer Electrolytes.

    Science.gov (United States)

    Mohanta, Jagdeep; Anwar, Shahid; Si, Satyabrata

    2016-06-01

    The present work describes the synthesis of some poly(ethylene oxide)-based nanocomposite polymer electrolyte films using various silica nanostructures as the inorganic filler by simple solution mixing technique, in which the nature of the silica nanostructures play a vital role in modulating their electrochemical performances at room temperature. The silica nanostructures are prepared by ammonical hydrolysis of tetraethyl orthosilicate following the modified St6ber method. The resulting films are characterized by X-ray diffraction and differential scanning calorimeter to study their crystallinity. Room temperature AC impedance spectroscopy is utilized to determine the Li+ ion conductivity of the resulting films. The observed conductivity values of various NCPE films depend on the nature of silica filling as well as on their surface characteristics and also on the varying PEO-Li+ ratio, which is observed to be in the order of 10(-7)-10(-6) S cm(-1).

  10. Composite polymer electrolyte containing ionic liquid and functionalized polyhedral oligomeric silsesquioxanes for anhydrous PEM applications.

    Science.gov (United States)

    Subianto, Surya; Mistry, Mayur K; Choudhury, Namita Roy; Dutta, Naba K; Knott, Robert

    2009-06-01

    A new type of supported liquid membrane was made by combining an ionic liquid (IL) with a Nafion membrane reinforced with multifunctional polyhedral oligomeric silsesquioxanes (POSSs) using a layer-by-layer strategy for anhydrous proton-exchange membrane (PEM) application. The POSS was functionalized by direct sulfonation, and the sulfonated POSS (S-POSS) was incorporated into Nafion 117 membranes by the infiltration method. The resultant hybrid membrane shows strong ionic interaction between the Nafion matrix and the multifunctional POSS, resulting in increased glass transition temperature and thermal stability at very low loadings of S-POSS (1%). The presence of S-POSS has also improved the proton conductivity especially at low humidities, where it shows a marked increase due to its confinement in the ionic domains and promotes water uptake by capillary condensation. In order to achieve anhydrous conductivity, the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMI-BTSI) was incorporated into these membranes to provide proton conduction in the absence of water. Although the incorporation of an IL shows a plasticizing effect on the Nafion membrane, the S-POSS composite membrane with an IL shows a higher modulus at high temperatures compared to Nafion 117 and a Nafion-IL membrane, with significantly higher proton conductivity (5 mS/cm at 150 degrees C with 20% IL). This shows the ability of the multifunctional POSS and IL to work symbiotically to achieve the desirable proton conductivity and mechanical properties of such membranes by enhancing the ionic interaction within the material.

  11. Internal hydration H{sub 2}/O{sub 2} 100 cm{sup 2} polymer electrolyte membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Miachon, S [CEA, Dept. de Recherche Fondamentale sur la Matiere Condensee, SESAM/PCM, 38 - Grenoble (France); Aldebert, P [CEA, Dept. de Recherche Fondamentale sur la Matiere Condensee, SESAM/PCM, 38 - Grenoble (France)

    1995-07-01

    This work deals with a new arrangement of a polymer electrolyte membrane fuel cell (PEMFC) support which allows the operation of a 100 cm{sup 2} surface area fuel cell with cold and unhumidified gases. Hydrogen is not recycled. Both gases (pure hydrogen and oxygen) are heated and humidified internally, each one crossing a porous carbon block. This allows a simplified water management. Classical low platinum loading E-Tek{sup R} electrodes, hot-pressed on Nafion{sup R} 117 and 112 membranes, are used. Performances are then a little higher than those of comparable PEMFCs in the literature: 0.7 V at 0.7 A/cm{sup 2} for Nafion{sup R} 117, and 0.724 V at 1 A/cm{sup 2} for Nafion{sup R} 112, under 4/6 bar (absolute) of H{sub 2}/O{sub 2} at 100 C. The values of PEMFC resistance obtained in fitting the data were found to be R=0.254 (with Nafion{sup R} 117) and 0.108 {Omega} cm{sup 2} (with Nafion{sup R} 112). The membrane contribution to the cell resistance was then estimated to be R{sub m}=0.204 and 0.058 {Omega} cm{sup 2}, respectively (with Nafion{sup R} conductivity estimated at 0.103 S/cm at 100 C in working fuel cell conditions). This membrane is therefore the major contributor to the total cell resistance. (orig.)

  12. Nanosized TiN-SBR hybrid coating of stainless steel as bipolar plates for polymer electrolyte membrane fuel cells

    International Nuclear Information System (INIS)

    Kumagai, Masanobu; Myung, Seung-Taek; Asaishi, Ryo; Sun, Yang-Kook; Yashiro, Hitoshi

    2008-01-01

    In attempt to improve interfacial electrical conductivity of stainless steel for bipolar plates of polymer electrolyte membrane fuel cells, TiN nanoparticles were electrophoretically deposited on the surface of stainless steel with elastic styrene butadiene rubber (SBR) particles. From transmission electron microscopic observation, it was found that the TiN nanoparticles (ca. 50 nm) surrounded the spherical SBR particles (ca. 300-600 nm), forming agglomerates. They were well adhered on the surface of the type 310S stainless steel. With help of elasticity of SBR, the agglomerates were well fitted into the interfacial gap between gas diffusion layer (GDL) and stainless steel bipolar plate, and the interfacial contact resistance (ICR), simultaneously, was successfully reduced. A single cell using the TiN nanoparticles-coated bipolar plates, consequently, showed comparable cell performance with the graphite employing cell at a current density of 0.5 A cm -2 (12.5 A). Inexpensive TiN nanoparticle-coated type 310S stainless steel bipolar plates would become a possible alternate for the expensive graphite bipolar plates as use in fuel cell applications

  13. Pressure drop and flow distribution characteristics of single and parallel serpentine flow fields for polymer electrolyte membrane fuel cells

    International Nuclear Information System (INIS)

    Baek, Seung Man; Kim, Charn Jung; Jeon, Dong Hyup; Nam, Jin Hyun

    2012-01-01

    This study numerically investigates pressure drop and flow distribution characteristics of serpentine flow fields (SFFs) that are designed for polymer electrolyte membrane fuel cells, which consider the Poiseuille flow with secondary pressure drop in the gas channel (GC) and the Darcy flow in the porous gas diffusion layer (GDL). The numerical results for a conventional SFF agreed well with those obtained via computational fluid dynamics simulations, thus proving the validity of the present flow network model. This model is employed to characterize various single and parallel SFFs, including multi-pass serpentine flow fields (MPSFFs). Findings reveal that under rib convection (convective flow through GDL under an interconnector rib) is an important transport process for conventional SFFs, with its intensity being significantly enhanced as GDL permeability increases. The results also indicate that under rib convection can be significantly improved by employing MPSFFs as the reactant flow field, because of the closely interlaced structure of GC regions that have different path lengths from the inlet. However, reactant flow rate through GCs proportionally decreases as under rib convection intensity increases, suggesting that proper optimization is required between the flow velocity in GCs and the under rib convection intensity in GDLs

  14. Novel synthesis of highly durable and active Pt catalyst encapsulated in nitrogen containing carbon for polymer electrolyte membrane fuel cell

    Science.gov (United States)

    Lee, Hyunjoon; Sung, Yung-Eun; Choi, Insoo; Lim, Taeho; Kwon, Oh Joong

    2017-09-01

    Novel synthesis of a Pt catalyst encapsulated in a N-containing carbon layer for use in a polymer electrolyte membrane fuel cell is described in this study. A Pt-aniline complex, formed by mixing Pt precursor and aniline monomer, was used as the source of Pt, C, and N. Heat treatment of the Pt-aniline complex with carbon black yielded 5 nm Pt nanoparticles encapsulated by a N-containing carbon layer originating from aniline carbonization. The synthesized Pt catalyst exhibited higher mass specific activity to oxygen reduction reaction than that shown by conventional Pt/C catalyst because pyridinic N with graphitic carbon in the carbon layer provided active sites for oxygen reduction reaction in addition to those provided by Pt. In single cell testing, initial performance of the synthesized catalyst was limited because the thick catalyst layer increased resistance related to mass transfer. However, it was observed that the carbon layer successfully prevented Pt nanoparticles from growing via agglomeration and Ostwald ripening under fuel cell operation, thereby improving durability. Furthermore, a mass specific performance of the synthesized catalyst higher than that of a conventional Pt/C catalyst was achieved by modifying the synthesized catalyst's layer thickness.

  15. Voltage Oscillations in a Polymer Electrolyte Membrane Fuel Cell with Pd-Pt/C and Pd/C Anodes.

    Science.gov (United States)

    Nogueira, Jéssica Alves; Varela, Hamilton

    2017-10-01

    Polymer electrolyte membrane fuel cells (PEMFC) fed with H 2 contaminated with CO may exhibit oscillatory behavior when operated galvanostatically. The self-organization of the anodic overpotential is interesting because it can be accompanied by an increase in the average performance. Herein we report experimental studies of voltage oscillations that emerge in a PEMFC equipped with a Pd/C or PdPt/C anode and fed with H 2 contaminated with CO (100 ppm). We used on-line mass spectrometry to investigate how the mass fragments associated with CO 2 and CO ( m / z 44 and 28, respectively) varied with the voltage oscillations. Overall, we observed that oscillations in the anodic overpotential are in phase with that of the CO and CO 2 signals. This fact is consistent with an autonomous adsorption-oxidation cyclic process. For both anodes, it has been observed that, in general, an increase in current density implies an increase in oscillatory frequency. By using CO stripping, we also discuss how the onset of CO oxidation is related to the maximum overpotential reached during a cycle, whereas the minimum overpotential can be associated with the catalytic activity of the electrode for H 2 oxidation.

  16. An electrochemical impedance spectroscopy study of polymer electrolyte membrane fuel cells electrocatalyst single wall carbon nanohorns-supported.

    Science.gov (United States)

    Brandão, Lúcia; Boaventura, Marta; Passeira, Carolina; Gattia, Daniele Mirabile; Marazzi, Renzo; Antisari, Marco Vittori; Mendes, Adélio

    2011-10-01

    Electrochemical impedance spectroscopy (EIS) was used to study the polymer electrolyte membrane fuel cells (PEMFC) performance when using single wall carbon nanohorns (SWNH) to support Pt nanoparticles. Additionally, as-prepared and oxidized SWNH Pt-supports were compared with conventional carbon black. Two different oxidizing treatments were considered: oxygen flow at 500 degrees C and reflux in an acid solution at 85 degrees C. Both oxidizing treatments increased SWNH surface area; oxygen treatment increased surface area 4 times while acid treatment increased 2.6 times. The increase in surface area should be related to the opening access to the inner tube of SWNH. Acid treatment of SWNH increased chemical fragility and decreased electrocatalyst load in comparison with as-prepared SWNH. On the other hand, the oxygen treated SWNH sample allowed to obtain the highest electrocatalyst load. The use of as-prepared and oxygen treated SWNH showed in both cases catalytic activities 60% higher than using conventional carbon black as electrocatalyst support in PEMFC. Moreover, EIS analysis indicated that the major improvement in performance is related to the cathode kinetics in the as-prepared SWNH sample, while concerning the oxidized SWNH sample, the improvements are related to the electrokinetics in both anode and cathode electrodes. These improvements should be related with differences in the hydrophobic character between SWNH and carbon black.

  17. A comparison of low-pressure and supercharged operation of polymer electrolyte membrane fuel cell systems for aircraft applications

    Science.gov (United States)

    Werner, C.; Preiß, G.; Gores, F.; Griebenow, M.; Heitmann, S.

    2016-08-01

    Multifunctional fuel cell systems are competitive solutions aboard future generations of civil aircraft concerning energy consumption, environmental issues, and safety reasons. The present study compares low-pressure and supercharged operation of polymer electrolyte membrane fuel cells with respect to performance and efficiency criteria. This is motivated by the challenge of pressure-dependent fuel cell operation aboard aircraft with cabin pressure varying with operating altitude. Experimental investigations of low-pressure fuel cell operation use model-based design of experiments and are complemented by numerical investigations concerning supercharged fuel cell operation. It is demonstrated that a low-pressure operation is feasible with the fuel cell device under test, but that its range of stable operation changes between both operating modes. Including an external compressor, it can be shown that the power demand for supercharging the fuel cell is about the same as the loss in power output of the fuel cell due to low-pressure operation. Furthermore, the supercharged fuel cell operation appears to be more sensitive with respect to variations in the considered independent operating parameters load requirement, cathode stoichiometric ratio, and cooling temperature. The results indicate that a pressure-dependent self-humidification control might be able to exploit the potential of low-pressure fuel cell operation for aircraft applications to the best advantage.

  18. 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.

  19. Stability and performance improvement of a polymer electrolyte membrane fuel cell stack by laser perforation of gas diffusion layers

    Energy Technology Data Exchange (ETDEWEB)

    Gerteisen, Dietmar; Sadeler, Christian [Fraunhofer Institute for Solar Energy Systems ISE, Department of Energy Technology, Heidenhofstrasse 2, 79110 Freiburg (Germany)

    2010-08-15

    The performance and stability of a hydrogen-driven polymer electrolyte membrane fuel cell stack (6-cell PEFC stack) are investigated with regard to pore flooding within the gas diffusion layers (GDLs). Two short stacks with various GDLs (Toray TGP-H-060 untreated and laser-perforated) were characterized at different operating conditions by several characterization techniques such as constant current load, polarization curve, chronoamperometry and chronovoltammetry. The experimental results reveal that the perforation of the cathode GDLs improves the water transport in the porous media and thus the performance as well as the stability of the operating stack in medium and high current density range. A reduced pore flooding is verified when using the customized laser-perforated GDLs. The GDL perforation has a huge potential to balance the inhomogeneous in-plane saturation conditions between the inlet and outlet area of the cell and to compensate to a certain degree the effects of temperature distribution within a stack regarding the water management. (author)

  20. Stability and performance improvement of a polymer electrolyte membrane fuel cell stack by laser perforation of gas diffusion layers

    Science.gov (United States)

    Gerteisen, Dietmar; Sadeler, Christian

    The performance and stability of a hydrogen-driven polymer electrolyte membrane fuel cell stack (6-cell PEFC stack) are investigated with regard to pore flooding within the gas diffusion layers (GDLs). Two short stacks with various GDLs (Toray TGP-H-060 untreated and laser-perforated) were characterized at different operating conditions by several characterization techniques such as constant current load, polarization curve, chronoamperometry and chronovoltammetry. The experimental results reveal that the perforation of the cathode GDLs improves the water transport in the porous media and thus the performance as well as the stability of the operating stack in medium and high current density range. A reduced pore flooding is verified when using the customized laser-perforated GDLs. The GDL perforation has a huge potential to balance the inhomogeneous in-plane saturation conditions between the inlet and outlet area of the cell and to compensate to a certain degree the effects of temperature distribution within a stack regarding the water management.

  1. Binderless electrodes for high-temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Fernandez, Santiago Martin; Li, Qingfeng; Steenberg, Thomas

    2014-01-01

    A new electrode concept was proved with no polymeric binder in the catalyst layer for acid-doped polybenzimidazole (PBI) membrane fuel cells. It shows that a stable interface between the membrane and the catalyst layer can be retained when a proton conducting acid phase is established. The absenc...

  2. A numerical investigation of the effects of membrane swelling in polymer electrolyte fuel cells

    International Nuclear Information System (INIS)

    Tiss, Faysal; Chouikh, Ridha; Guizani, Amenallah

    2013-01-01

    Highlights: ► Membrane water content is controlled by the operating conditions in the cathode. ► When the membrane is in contact with water, only pore size varies. ► Membrane water content increase by increasing the functioning temperature. ► Good agreement between computational results and previous reported experimental data. - Abstract: A two-dimensional computational fluid dynamics model of PEM fuel cell is developed by taking into account the electrochemical, mass and heat transfer process occurring in the cathode compartment. Additionally, this model includes the effect of water content in the membrane swelling phenomenon. Several parameters such as gases temperature, inlet velocity and membrane characteristics are too investigated to establish their effect on the PEM fuel cell performance. The membrane water content and the air fraction variation in the gas channel are examined for diverse values of Reynolds number. In particular, the desirable inlet flow for enhancing the performance of the PEM fuel cell is determined by examining membrane water content patterns. The methodology in this study is useful to the control of water management and gas diffusion layer design

  3. Solid state double layer capacitor based on a polyether polymer electrolyte blend and nanostructured carbon black electrode composites

    Energy Technology Data Exchange (ETDEWEB)

    Lavall, Rodrigo L.; Borges, Raquel S.; Calado, Hallen D.R.; Welter, Cezar; Trigueiro, Joao P.C.; Silva, Glaura G. [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, CEP 31270-901, Belo Horizonte (Brazil); Rieumont, Jacques [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, CEP 31270-901, Belo Horizonte (Brazil); Facultad de Quimica, Universidad de La Habana, Habana 10400 (Cuba); Neves, Bernardo R.A. [Departamento de Fisica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, CEP 31270-901, Belo Horizonte (Brazil)

    2008-03-01

    An all solid double layer capacitor was assembled by using poly(ethylene oxide)/poly(propylene glycol)-b-poly(ethylene glycol)-b-poly(propylene glycol)-bis(2-aminopropyl ether) blend (PEO-NPPP) and LiClO{sub 4} as polymer electrolyte layer and PEO-NPPP-carbon black (CB) as electrode film. High molecular weight PEO and the block copolymer NPPP with molecular mass of 2000 Da were employed, which means that the design is safe from the point of view of solvent or plasticizer leakage and thus, a separator is not necessary. Highly conductive with large surface area nanostructured carbon black was dispersed in the polymer blend to produce the electrode composite. The electrolyte and electrode multilayers prepared by spray were studied by differential scanning calorimetry, atomic force microscopy (AFM) and impedance spectroscopy. The ionic conductivity as a function of temperature was fitted with the Williams-Landel-Ferry equation, which indicates a conductivity mechanism typical of solid polymer electrolyte. AFM images of the nanocomposite electrode showed carbon black particles of approximately 60 nm in size well distributed in a semicrystalline and porous polymer blend coating. The solid double layer capacitor with 10 wt.% CB was designed with final thickness of approximately 130 {mu}m and delivered a capacitance of 17 F g{sup -1} with a cyclability of more than 1000 cycles. These characteristics make possible the construction of a miniature device in complete solid state which will avoid electrolyte leakage and present a performance superior to other similar electric double layer capacitors (EDLCs) presented in literature, as assessed in specific capacitance by total carbon mass. (author)

  4. Peclet number analysis of cross-flow in porous gas diffusion layer of polymer electrolyte membrane fuel cell (PEMFC).

    Science.gov (United States)

    Suresh, P V; Jayanti, Sreenivas

    2016-10-01

    Adoption of hydrogen economy by means of using hydrogen fuel cells is one possible solution for energy crisis and climate change issues. Polymer electrolyte membrane (PEM) fuel cell, which is an important type of fuel cells, suffers from the problem of water management. Cross-flow is induced in some flow field designs to enhance the water removal. The presence of cross-flow in the serpentine and interdigitated flow fields makes them more effective in proper distribution of the reactants on the reaction layer and evacuation of water from the reaction layer than diffusion-based conventional parallel flow fields. However, too much of cross-flow leads to flow maldistribution in the channels, higher pressure drop, and membrane dehydration. In this study, an attempt has been made to quantify the amount of cross-flow required for effective distribution of reactants and removal of water in the gas diffusion layer. Unit cells containing two adjacent channels with gas diffusion layer (GDL) and catalyst layer at the bottom have been considered for the parallel, interdigitated, and serpentine flow patterns. Computational fluid dynamics-based simulations are carried out to study the reactant transport in under-the-rib area with cross-flow in the GDL. A new criterion based on the Peclet number is presented as a quantitative measure of cross-flow in the GDL. The study shows that a cross-flow Peclet number of the order of 2 is required for effective removal of water from the GDL. Estimates show that this much of cross-flow is not usually produced in the U-bends of Serpentine flow fields, making these areas prone to flooding.

  5. The Seebeck coefficient and the Peltier effect in a polymer electrolyte membrane cell with two hydrogen electrodes

    International Nuclear Information System (INIS)

    Kjelstrup, S.; Vie, P.J.S.; Akyalcin, L.; Zefaniya, P.; Pharoah, J.G.; Burheim, O.S.

    2013-01-01

    Highlights: • The heat change associated with the hydrogen electrode in a polymer electrolyte cell is determined from Seebeck coefficient measurements. • When electric current is passed from left to right in the outer circuit, the anode becomes warmer, while the cathode becomes colder in a thermoelectric cell with hydrogen electrodes. • At Soret equilibrium for water in the fuel cell, most of the entropy of the fuel cell reaction is generated at the anode. -- Abstract: We report that the Seebeck coefficient of a Nafion membrane cell with hydrogen electrodes saturated with water vapour, at 1 bar hydrogen pressure and 340 K, is equal to 670 ± 50 μV/K, meaning that the entropy change of the anode reaction at reversible conditions (67 J/(K mol)) corresponds to a reversible heat release of 22 kJ/mol. The transported entropy of protons across the membrane at Soret equilibrium was estimated from this value to 1 ± 5 J/(K mol). The results were supported by the expected variation in the Seebeck coefficient with the hydrogen pressure. We report also the temperature difference of the electrodes, when passing electric current through the cell, and find that the anode is heated (a Peltier heat effect), giving qualitative support to the result for the Seebeck coefficient. The Seebeck and Peltier effects are related by non-equilibrium thermodynamics theory, and the Peltier heat of the cathode in the fuel cell is calculated for steady state conditions to 6 ± 2 kJ/mol at 340 K. The division of the reversible heat release between the anode and the cathode, can be expected to vary with the current density, as the magnitude of the current density can have a big impact on water transport and water concentration profile

  6. Smart coating process of proton-exchange membrane for polymer electrolyte fuel cell

    International Nuclear Information System (INIS)

    Leu, Hoang-Jyh; Chiu, Kuo-Feng; Lin, Chiu-Yue

    2013-01-01

    Highlights: ► Using oxygen plasma and smart coating technique for membrane modification. ► Oxygen plasma treatment can increase the reaction area of the membrane. ► AFM, SEM, FT-IR, XPS, EIS spectra can prove the surface treatment process. ► Nafion membrane modification can reduce Rct and enhance current density. - Abstract: The interfaces of electrolyte|catalyst|electrode play an important role in the performance of proton-exchange membrane fuel cells (PEMFCs). Increasing the interface effective area and lowering the charge transfer resistance of the interface are significant issues to promote the cell performance. In this study, oxygen plasma treatment was used to increase the surface roughness of Nafion®117 membrane, and then a smart coating process was applied to fabricate the initial Pt/C catalyst layer, which served to reduce the charge transfer resistance of the interface. The morphology and surface characteristics of membranes have been qualified by scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. These results show that the plasma treatments and smart coating processes were effective in reducing the interface charge transfer resistance. At optimal condition, the interface charge transfer resistance was 0.45 Ω/cm 2 which was 1–2 order less than the untreated ones

  7. On water transport in polymer electrolyte membranes during the passage of current

    DEFF Research Database (Denmark)

    Berning, Torsten

    2011-01-01

    This article discusses an approach to model the water transport in the membranes of PEM fuel cells during operation. Starting from a frequently utilized equation the various transport mechanisms are analyzed in detail. It is shown that the commonly used approach to simply balance the electro......-osmotic drag (EOD) with counter diffusion and/or hydraulic permeation is flawed, and that any net transport of water through the membrane is caused by diffusion. Depending on the effective drag the cathode side of the membrane may experience a lower hydration than the anode side. The effect of a water......-uptake layer on the net water transport will also be pictured. Finally, the effect of EOD is visualized using “Newton’s cradle”....

  8. Fluorinated building blocks for next-generation polymer electrolyte membrane fuel cells

    NARCIS (Netherlands)

    Wadekar, M.N.

    2012-01-01

    The purpose of this thesis is to design, create and study basic building blocks for the construction of self-assembled nanostructured electrodes and membranes for PEMFC. The research described deals with the synthesis of polymerizable fluorosurfactant (1) and its non-polymerizable analogue (2) and

  9. Low stoichiometry operation of a polymer electrolyte membrane fuel cell employing the interdigitated flow field design

    DEFF Research Database (Denmark)

    Berning, Torsten; Odgaard, Madeleine; Kær, Søren Knudsen

    2011-01-01

    Fuel cell operation on dry reactant gases under low stoichiometry conditions employing the interdigitated flow field is investigated using a multi-fluid model. It is assumed that the MEA contains a water uptake layer which facilitates water absorption to the membrane and hence prevents the anode...

  10. 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.

  11. Increasing the operation temperature of polymer electrolyte membranes for fuel cells: From nanocomposites to hybrids

    Science.gov (United States)

    Licoccia, Silvia; Traversa, Enrico

    Among the possible systems investigated for energy production with low environmental impact, polymeric electrolyte membrane fuel cells (PEMFCs) are very promising as electrochemical power sources for application in portable technology and electric vehicles. For practical applications, operating FCs at temperatures above 100 °C is desired, both for hydrogen and methanol fuelled cells. When hydrogen is used as fuel, an increase of the cell temperature produces enhanced CO tolerance, faster reaction kinetics, easier water management and reduced heat exchanger requirement. The use of methanol instead of hydrogen as a fuel for vehicles has several practical benefits such as easy transport and storage, but the slow oxidation kinetics of methanol needs operating direct methanol fuel cells (DMFCs) at intermediate temperatures. For this reason, new membranes are required. Our strategy to achieve the goal of operating at temperatures above 120 °C is to develop organic/inorganic hybrid membranes. The first approach was the use of nanocomposite class I hybrids where nanocrystalline ceramic oxides were added to Nafion. Nanocomposite membranes showed enhanced characteristics, hence allowing their operation up to 130 °C when the cell was fuelled with hydrogen and up to 145 °C in DMFCs, reaching power densities of 350 mW cm -2. The second approach was to prepare Class II hybrids via the formation of covalent bonds between totally aromatic polymers and inorganic clusters. The properties of such covalent hybrids can be modulated by modifying the ratio between organic and inorganic groups and the nature of the chemical components allowing to reach high and stable conductivity values up to 6.4 × 10 -2 S cm -1 at 120 °C.

  12. Polymer electrolyte membrane fuel cell (PEMFC) flow field plate: design, materials and characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, P.J.; Pollet, B.G. [PEM Fuel Cell Research Group, School of Chemical Engineering, University of Birmingham, Edgbaston, B15 2TT (United Kingdom)

    2010-08-15

    This review describes some recent developments in the area of flow field plates (FFPs) for proton exchange membrane fuel cells (PEMFCs). The function, parameters and design of FFPs in PEM fuel cells are outlined and considered in light of their performance. FFP materials and manufacturing methods are discussed and current in situ and ex situ characterisation techniques are described. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  13. Preparation and investigation of cheap polymer electrolyte membranes for fuel cells

    DEFF Research Database (Denmark)

    Larsen, Mikkel Juul; Ma, Yue; Lund, Peter Brilner

    ­tro­ly­tic pro­per­ti­es. Grafting with a fraction of DVB in the order of 1-2 vol-% of the total mo­no­mers seems to be advantageous for both of the two grafting sys­tems as a com­pro­mise between high chemical stability and good proton con­duc­tivity of the final membrane. The use of methyl­sty­rene and t......-bu­tyl­styrene as grafting mo­no­mers instead of sty­rene gives the resulting membranes a significantly increased chem­i­cal stability, while a rea­son­able pro­ton conductivity can still be ob­tai­ned. Both membrane systems show a smaller methanol up­take than water uptake. [i] Kreuer, K.-D.; Paddison, S. J.; Spohr, E.......; Schuster, M.; Chemical Reviews 104 (2004) 4637-4678 [ii] Skou, E.; Kauranen, P.; Hentschel, J.; Solid State Ionics 97 (1997) 333-337 [iii] Fuel Cell Handbook; Seventh Edition; EG&G Technical Services, Inc.; 2004; p. 3.1-3.25 [iv] Doyle, M.; Rajendran, G. in Handbook of Fuel Cells - Fundamentals, Technology...

  14. Operation Strategies Based on Carbon Corrosion and Lifetime Investigations for High Temperature Polymer Electrolyte Membrane Fuel Cell Stacks

    DEFF Research Database (Denmark)

    Kannan, A.; Kaczerowski, J.; Kabza, A.

    2018-01-01

    This paper is aimed to develop operation strategies or high temperature polymer electrolyte fuel cells (HT-PEMFCs) stacks in order to enhance the endurance by mitigating carbon oxidation reaction. The testing protocols are carefully designed to suit the operating cycle for the realistic application...

  15. Multilayer graphene for long-term corrosion protection of stainless steel bipolar plates for polymer electrolyte membrane fuel cell

    DEFF Research Database (Denmark)

    Stoot, Adam Carsten; Camilli, Luca; Spiegelhauer, Susie Ann

    2015-01-01

    Abstract Motivated by similar investigations recently published (Pu et al., 2015), we report a comparative corrosion study of three sets of samples relevant as bipolar plates for polymer electrolyte fuel cells: stainless steel, stainless steel with a nickel seed layer (Ni/SS) and stainless steel...

  16. Influence of carbon monoxide on the cathode in high-temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Søndergaard, Stine; Cleemann, Lars Nilausen; Jensen, Jens Oluf

    2017-01-01

    This paper describes the results of adding small amounts of CO gas to the cathode side in a HT-PEM fuel cell with a polybenzimidazole (PBI) membrane running on either oxygen or air. Experimental conditions: Temperature ranges 120–160 °C, constant current either 200 mA/cm2 or 800 mA/cm2 and CO...... improvement of the potential is seen before the situation goes back to normal. A good explanation for this is a competition between CO, O2 and H3PO4 at the three phase boundaries, also that a steady state exist in which CO constantly is oxidized to CO2....

  17. Further Improvement and System Integration of High Temperature Polymer Electrolyte Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Li, Qingfeng; Jensen, Jens Oluf

    The strategic developments of the FURIM are in three steps: (1) further improvement of the high temperature polymer membranes and related materials; (2) development of technological units including fuel cell stack, hydrocarbon reformer and afterburner, that are compatible with the HT-PEMFC; and (3......) integration of the HT-PEMFC stack with these compatible subunits. The main goal of the project is a 2kWel HT-PEMFC stack operating in a temperature range of 150-200°C, with a single cell performance target of 0.7 A/cm² at a cell voltage around 0.6 V. The target durability is more than 5,000 hours...

  18. Quantum-beam technology: A versatile tool for developing polymer electrolyte fuel-cell membranes

    Energy Technology Data Exchange (ETDEWEB)

    Yamaki, Tetsuya [Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2010-09-15

    This paper describes the versatile application of quantum beam-based technology to the development of proton exchange membranes (PEMs) for fuel-cell applications. The {gamma}-ray or electron-beam induced radiation grafting offers a way to prepare PEMs; typically, the radical-initiated polymerization of a styrene or styrene-derivative monomer on a base polymer is followed by a sulfonation step. Novel PEMs were previously obtained using radiation-crosslinked fluoropolymers as the base material. Interestingly, combining this radiation-crosslinking process with the well-known chemical crosslinker method enabled one to obtain the ''multiply''-crosslinked PEMs, in which both the main and grafted chains have covalently bridged structures leading to a high durability. The bombardment of heavy ions accelerated to MeV or higher energies produces a continuous trail of excited and ionized molecules in polymers, which is known as a latent track. The approach using this ion-track technology is based on the chemical etching and/or modification of each track with diameters of tens to hundreds of nanometers. The resulting ''nano-structure controlled'' PEM was found to have perfect one-dimensional proton-conductive pathways parallel to its thickness direction, while, in contrast, other existing PEMs mostly exhibited proton transport in the three-dimensional random media. The hierarchical structures of the PEMs, ranging from nanometers to micrometers, were revealed by small-angle neutron scattering experiments using a cold or thermal neutron beam. The information in such a wide length scale led to a deep insight into the dynamic properties inside the PEM from a molecular to macroscopic level, which can provide feedback for the reconsideration and optimization of the preparation procedure. As demonstrated above in the author's studies, it is important to understand that every quantum beam is different, thereby making the right beam choice

  19. Lithiated Nafion as polymer electrolyte for solid-state lithium sulfur batteries using carbon-sulfur composite cathode

    Science.gov (United States)

    Gao, Jing; Sun, Chunshui; Xu, Lei; Chen, Jian; Wang, Chong; Guo, Decai; Chen, Hao

    2018-04-01

    Due to flexible property and light weight, the lithiated Nafion membrane swollen with PC (PC-Li-Nafion) has been employed as both solid-state electrolyte and separator to fabricate solid-state Li-S cells. The electrochemical measurements of PC-Li-Nafion membrane show that its Li-ion transference number is 0.928, ionic conductivity of 2.1 × 10-4 S cm-1 can be achieved at 70 °C and its electrochemical window is 0 ∼ +4.1 V vs. Li+/Li. It is observed that the Li dendrites are suppressed by using PC-Li-Nafion membrane due to its single-ion conducting property. The amounts of Li-Nafion resin binder and conductive carbon in the cathode are optimized as 40% and 10% respectively to make a balance of ionic and electronic conductivities. A thin-layer Li-Nafion resin with a thickness of around 2 μm is fabricated between the cathode and PC-Li-Nafion membrane to improve the interfacial contact and further enhance the specific capacity of the cell. When measured at 70 °C, the Li-S cell delivers a reversible specific capacity of 1072.8 mAh g-1 (S) at 0.05 C and 895 mAh g-1 (S) at 1 C. The capacity retention at 1 C is 89% after 100 cycles. These results suggest that high-performance solid-state Li-S cells can be fabricated with the Li-Nafion polymer electrolyte.

  20. Nanostructured ZnO/Y2O3:Eu for use as fillers in luminescent polymer electrolyte composites

    International Nuclear Information System (INIS)

    Abdullah, Mikrajuddin; Panatarani, Camellia; Kim, Tae-Oh; Okuyama, Kikuo

    2004-01-01

    Nanostructured ZnO/Eu and ZnO/Y 2 O 3 :Eu composites have been produced by hydrolizing a mixture of zinc acetate, yttrium acetate and europium acetate in ethanol solution, followed by mixing with lithium hydroxide. By analyzing the ICP data, XRD patterns and luminescence emission spectra we concluded that the europium and yttrium compounds appeared as coating layer on the surface of ZnO nanoparticles. Without heating, these layers were in amorphous state and transformed into crystalline state after annealing at temperatures of above 600 deg. C around 30 min. We observed the presence of lithium hydroxide concentration threshold below which no coating layer was formed on the surface of ZnO nanoparticles. The emission intensity of ZnO/Y 2 O 3 :Eu was found to increase with increasing annealing temperature, while the crystalline size of Y 2 O 3 (close to 20 nm) decreased with increasing the annealing temperature. The powder produced might be used as fillers in luminescent polymer electrolyte composites, which can produce two colors, i.e., red (Eu emission) when excited using a wavelength of around 254 nm and green (emitted by ZnO nanoparticles) when excited using a wavelength of around 365 nm

  1. Dielectric relaxations and conduction mechanisms in polyether-clay composite polymer electrolytes under high carbon dioxide pressure.

    Science.gov (United States)

    Kitajima, Shunsuke; Bertasi, Federico; Vezzù, Keti; Negro, Enrico; Tominaga, Yoichi; Di Noto, Vito

    2013-10-21

    The composite material P(EO/EM)-Sa consisting of synthetic saponite (Sa) dispersed in poly[ethylene oxide-co-2-(2-methoxyethoxy)ethyl glycidyl ether] (P(EO/EM)) is studied by "in situ" measurements using broadband electrical spectroscopy (BES) under pressurized CO2 to characterize the dynamic behavior of conductivity and the dielectric relaxations of the ion host polymer matrix. It is revealed that there are three dielectric relaxation processes associated with: (I) the dipolar motions in the short oxyethylene side chains of P(EO/EM) (β); and (II) the segmental motion of the main chains comprising the polyether components (αfast, αslow). αslow is attributed to the slow α-relaxation of P(EO/EM) macromolecules, which is hindered by the strong coordination interactions with the ions. Two conduction processes are observed, σDC and σID, which are attributed, respectively, to the bulk conductivity and the interdomain conductivity. The temperature dependence of conductivity and relaxation processes reveals that αfast and αslow are strongly correlated with σDC and σID. The "in situ" BES measurements under pressurized CO2 indicate a fast decrease in σDC at the initial CO2 treatment time resulting from the decrease in the concentration of polyether-M(n+) complexes, which is driven by the CO2 permeation. The relaxation frequency (fR) of αslow at the initial CO2 treatment time increases and shows a steep rise with time with the same behavior of the αfast mode. It is demonstrated that the interactions between polyether chains of P(EO/EM) and cations in the polymer electrolyte layers embedded in Sa are probably weakened by the low permittivity of CO2 (ε = 1.08). Thus, the formation of ion pairs in the polymer electrolyte domains of P(EO/EM)-Sa occurs, with a corresponding reduction in the concentration of ion carriers.

  2. Ionic Conductivity and Cycling Stability Improvement of PVDF/Nano-Clay Using PVP as Polymer Electrolyte Membranes for LiFePO4 Batteries

    Directory of Open Access Journals (Sweden)

    Endah R. Dyartanti

    2018-07-01

    Full Text Available In this paper, we present the characteristics and performance of polymer electrolyte membranes (PEMs based on poly(vinylidene fluoride (PVDF. The membranes were prepared via a phase-inversion method (non-solvent-induced phase separation (NIPS. As separators for lithium battery systems, additive modified montmorillonite (MMT nano-clay served as a filler and poly(vinylpyrrolidone (PVP was used as a pore-forming agent. The membranes modified with an additive (8 wt % nano-clay and 7 wt % PVP showed an increased porosity (87% and an uptake of a large amount of electrolyte (801.69%, which generated a high level of ionic conductivity (5.61 mS cm−1 at room temperature. A graphite/PEMs/LiFePO4 coin cell CR2032 showed excellent stability in cycling performance (average discharge capacity 127 mA h g−1. Based on these results, PEMs are promising materials to be used in Polymer Electrolyte Membranes in lithium-ion batteries.

  3. Determining the platinum loading and distribution of industrial scale polymer electrolyte membrane fuel cell electrodes using low energy X-ray imaging

    DEFF Research Database (Denmark)

    Holst, T.; Vassiliev, Anton; Kerr, R.

    2014-01-01

    Low energy X-ray imaging (E <25 keV) is herein demonstrated to be a rapid, effective and non-destructive tool for the quantitative determination of the platinum loading and distribution over the entire geometric area of gas diffusion electrodes for polymer electrolyte membrane fuel cells. A linea...... of electrodes fabricated using an industrial spraying process. This technique proves to be an attractive option for the electrode performance study, the process optimization and quality control of electrode fabrication on an industrial scale....

  4. Nonlinear empirical model of gas humidity-related voltage dynamics of a polymer-electrolyte-membrane fuel cell stack

    Science.gov (United States)

    Meiler, M.; Andre, D.; Schmid, O.; Hofer, E. P.

    Intelligent energy management is a cost-effective key path to realize efficient automotive drive trains [R. O'Hayre, S.W. Cha, W. Colella, F.B. Prinz. Fuel Cell Fundamentals, John Wiley & Sons, Hoboken, 2006]. To develop operating strategy in fuel cell drive trains, precise and computational efficient models of all system components, especially the fuel cell stack, are needed. Should these models further be used in diagnostic or control applications, then some major requirements must be fulfilled. First, the model must predict the mean fuel cell voltage very precisely in all possible operating conditions, even during transients. The model output should be as smooth as possible to support best efficient optimization strategies of the complete system. At least, the model must be computational efficient. For most applications, a difference between real fuel cell voltage and model output of less than 10 mV and 1000 calculations per second will be sufficient. In general, empirical models based on system identification offer a better accuracy and consume less calculation resources than detailed models derived from theoretical considerations [J. Larminie, A. Dicks. Fuel Cell Systems Explained, John Wiley & Sons, West Sussex, 2003]. In this contribution, the dynamic behaviour of the mean cell voltage of a polymer-electrolyte-membrane fuel cell (PEMFC) stack due to variations in humidity of cell's reactant gases is investigated. The validity of the overall model structure, a so-called general Hammerstein model (or Uryson model), was introduced recently in [M. Meiler, O. Schmid, M. Schudy, E.P. Hofer. Dynamic fuel cell stack model for real-time simulation based on system identification, J. Power Sources 176 (2007) 523-528]. Fuel cell mean voltage is calculated as the sum of a stationary and a dynamic voltage component. The stationary component of cell voltage is represented by a lookup-table and the dynamic voltage by a parallel placed, nonlinear transfer function. A

  5. Incorporating Embedded Microporous Layers into Topologically Equivalent Pore Network Models for Oxygen Diffusivity Calculations in Polymer Electrolyte Membrane Fuel Cell Gas Diffusion Layers

    International Nuclear Information System (INIS)

    Fazeli, Mohammadreza; Hinebaugh, James; Bazylak, Aimy

    2016-01-01

    Highlights: • Pore network model for modeling PEMFC MPL-coated GDL effective diffusivity. • Bilayered GDL (substrate and MPL) is modeled with a hybrid network of block MPL elements combined with discrete substrate pores. • Diffusivities of MPL-coated GDLs agree with analytical solutions. - Abstract: In this work, a voxel-based methodology is introduced for the hybridization of a pore network with interspersed nano-porous material elements allowing pore network based oxygen diffusivity calculations in a 3D image of a polymer electrolyte membrane (PEM) fuel cell gas diffusion layer (GDL) with an embedded microporous layer (MPL). The composite GDL is modeled by combining a hybrid network of block MPL elements with prescribed bulk material properties and a topologically equivalent network of larger discrete pores and throats that are directly derived from the 3D image of the GDL substrate. This hybrid network was incorporated into a pore network model, and effective diffusivity predictions of GDL materials with MPL coatings were obtained. Stochastically generated numerical models of carbon paper substrates with and without MPLs were used, and the pore space was directly extracted from this realistic geometry as the input for the pore network model. The effective diffusion coefficient of MPL-coated GDL materials was predicted from 3D images in a pore network modeling environment without resolving the nano-scale structure of the MPL. This method is particularly useful due to the disparate length scales that are involved when attempting to capture pore-scale transport in the GDL. Validation was performed by comparing our predicted diffusivity values to analytical predictions, and excellent agreement was observed. Upon conducting a mesh sensitivity study, it was determined that an MPL element size of 7 μm provided sufficiently high resolution for accurately describing the MPL nano-structure.

  6. Membranes of polyindene sulfonated and PVA for use as polymer electrolyte; Membranas mistas de poli(indeno) sulfonado e PVA para uso como eletrolito polimerico

    Energy Technology Data Exchange (ETDEWEB)

    Loser, N.; Silva, B.B.R. da; Brum, F.J.B.; Forte, M.M.C. [Universidade Federal do Rio Grande do Sul - Escola de Engenharia, Porto Alegre, RS (Brazil)

    2010-07-01

    This study is focused on developing polymer poly electrolytes for fuel cell PEM and aims to evaluate the efficiency of sulfonated polyindene as A polymer electrolyte in blends with poly (vinyl alcohol) (PVA). For this, polyindene synthesized in the lab was functionalized with sulfonic groups (-SO{sub 3}H), using as sulfonation agent acetyl sulfate in 1,2-dichloroethane. The membranes of sulfonated polyindene (SPInd) and PVA were prepared in aqueous medium, using glutaraldehyde as a PVA cross linker. The membranes SPInd/PVA were evaluated on the content of sulfonic groups, ion exchange capacity (IEC), degree of swelling in water and thermal stability (TGA). Electrochemical impedance analysis was used for ionic conductivity evaluation and DMA for the mechanical strength of the membranes. Preliminary results show that the membranes showed ion exchange capacity about 3.2 m equiv/g and degree of swelling in water of 550%. (author)

  7. Commercialization scenarios of polymer electrolyte membrane fuel cell applications for stationary power generation in the United States by the year 2015

    Science.gov (United States)

    Millett, Stephen; Mahadevan, Kathya

    Battelle is identifying the most likely markets and economic impacts of stationary polymer electrolyte membrane (PEM) fuel cells in the range of 1-250 kW in the U.S. by the year 2015. For this task, Battelle is using the Interactive Future Simulations (IFS™), an analytical modeling and forecasting tool that uses expert judgment, trend analysis, and cross-impact analysis methods to generate most likely future conditions for PEM fuel cell applications, market acceptance, commercial viability, and economic impacts. The cross-impact model contains 28 descriptors including commercial and technological advances in both polymer electrolyte membrane (PEM) fuel cells and fossil fuel technologies, sources of hydrogen, investments, public policy, environmental regulation, value to consumers, commercialization leadership, modes of generation, and the reliability and prices of grid electricity. One likely scenario to the year 2015 is that the PEM fuel cells will be limited to commercial and industrial customers in the range of 50-200 kW with a market size less than US$ 5 billion a year.

  8. Surface composition effect of nitriding Ni-free stainless steel as bipolar plate of polymer electrolyte fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yang; Shironita, Sayoko [Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Nakatsuyama, Kunio [Nakatsuyama Heat Treatment Co., Ltd., 1-1089-10, Nanyou, Nagaoka, Niigata 940-1164 (Japan); Souma, Kenichi [Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Hitachi Industrial Equipment Systems Co., Ltd., 3 Kanda Neribei, Chiyoda, Tokyo 101-0022 (Japan); Umeda, Minoru, E-mail: mumeda@vos.nagaokaut.ac.jp [Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188 (Japan)

    2016-12-01

    Graphical abstract: The anodic current densities in the passive region of nitrided SUS445-N stainless steel are lower than those of a non heat-treated SUS445 stainless steel and heat-treated SUS445-Ar stainless steel under an Ar atmosphere. It shows a better corrosion resistance for the SUS445 stainless steel after the nitriding heat treatment. - Highlights: • The nitriding heat treatment was carried out using Ni-free SUS445 stainless steel. • The corrosion resistance of the nitrided SUS445-N stainless steel was improved. • The structure of the nitrided SUS445-N stainless steel changed from α-Fe to γ-Fe. • The surface elemental components present in the steels affect the corrosion resistance. - Abstract: In order to increase the corrosion resistance of low cost Ni-free SUS445 stainless steel as the bipolar plate of a polymer electrolyte fuel cell, a nitriding surface treatment experiment was carried out in a nitrogen atmosphere under vacuum conditions, while an Ar atmosphere was used for comparison. The electrochemical performance, microstructure, surface chemical composition and morphology of the sample before and after the electrochemical measurements were investigated using linear sweep voltammetry (LSV), X-ray diffraction (XRD), glow discharge optical emission spectroscopy (GDS) and laser scanning microscopy (LSM) measurements. The results confirmed that the nitriding heat treatment not only increased the corrosion resistance, but also improved the surface conductivity of the Ni-free SUS445 stainless steel. In contrast, the corrosion resistance of the SUS445 stainless steel decreased after heat treatment in an Ar atmosphere. These results could be explained by the different surface compositions between these samples.

  9. IMIDAZOLE-BASED IONIC LIQUIDS FOR USE IN POLYMER ELECTROLYTE MEMBRANE FUEL CELLS: EFFECT OF ELECTRON-WITHDRAWING AND ELECTRON-DONATING SUBSTITUENTS

    Energy Technology Data Exchange (ETDEWEB)

    Chang, E.; Fu, Y.; Kerr, J.

    2009-01-01

    Current polymer electrolyte membrane fuel cells (PEMFCs) require humidifi cation for acceptable proton conductivity. Development of a novel polymer that is conductive without a water-based proton carrier is desirable for use in automobiles. Imidazole (Im) is a possible replacement for water as a proton solvent; Im can be tethered to the polymer structure by means of covalent bonds, thereby providing a solid state proton conducting membrane where the solvating groups do not leach out of the fuel cell. These covalent bonds can alter the electron availability of the Im molecule. This study investigates the effects of electron-withdrawing and electron-donating substituents on the conductivity of Im complexed with methanesulfonic acid (MSA) in the form of ionic liquids. Due to the changes in the electronegativity of nitrogen, it is expected that 2-phenylimidazole (2-PhIm, electron-withdrawing) will exhibit increased conductivity compared to Im, while 2-methylimidazole (2-MeIm, electron-donating) will exhibit decreased conductivity. Three sets of ionic liquids were prepared at defi ned molar ratios: Im-MSA, 2-PhIm-MSA, and 2-MeIm- MSA. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and 1H-NMR were used to characterize each complex. Impedance analysis was used to determine the conductivity of each complex. Both the 2-PhIm-MSA and 2-MeIm-MSA ionic liquids were found to be less conductive than the Im-MSA complex at base-rich compositions, but more conductive at acid-rich compositions. 1H-NMR data shows a downfi eld shift of the proton on nitrogen in 2-PhIm compared to Im, suggesting that other factors may diminish the electronic effects of the electron withdrawing group at base-rich compositions. Further studies examining these effects may well result in increased conductivity for Im-based complexes. Understanding the conductive properties of Im-derivatives due to electronic effects will help facilitate the development of a new electrolyte

  10. High Ionic Conductivity of Composite Solid Polymer Electrolyte via In Situ Synthesis of Monodispersed SiO2 Nanospheres in Poly(ethylene oxide).

    Science.gov (United States)

    Lin, Dingchang; Liu, Wei; Liu, Yayuan; Lee, Hye Ryoung; Hsu, Po-Chun; Liu, Kai; Cui, Yi

    2016-01-13

    High ionic conductivity solid polymer electrolyte (SPE) has long been desired for the next generation high energy and safe rechargeable lithium batteries. Among all of the SPEs, composite polymer electrolyte (CPE) with ceramic fillers has garnered great interest due to the enhancement of ionic conductivity. However, the high degree of polymer crystallinity, agglomeration of ceramic fillers, and weak polymer-ceramic interaction limit the further improvement of ionic conductivity. Different from the existing methods of blending preformed ceramic particles with polymers, here we introduce an in situ synthesis of ceramic filler particles in polymer electrolyte. Much stronger chemical/mechanical interactions between monodispersed 12 nm diameter SiO2 nanospheres and poly(ethylene oxide) (PEO) chains were produced by in situ hydrolysis, which significantly suppresses the crystallization of PEO and thus facilitates polymer segmental motion for ionic conduction. In addition, an improved degree of LiClO4 dissociation can also be achieved. All of these lead to good ionic conductivity (1.2 × 10(-3) S cm(-1) at 60 °C, 4.4 × 10(-5) S cm(-1) at 30 °C). At the same time, largely extended electrochemical stability window up to 5.5 V can be observed. We further demonstrated all-solid-state lithium batteries showing excellent rate capability as well as good cycling performance.

  11. Application of a Coated Film Catalyst Layer Model to a High Temperature Polymer Electrolyte Membrane Fuel Cell with Low Catalyst Loading Produced by Reactive Spray Deposition Technology

    Directory of Open Access Journals (Sweden)

    Timothy D. Myles

    2015-10-01

    Full Text Available In this study, a semi-empirical model is presented that correlates to previously obtained experimental overpotential data for a high temperature polymer electrolyte membrane fuel cell (HT-PEMFC. The goal is to reinforce the understanding of the performance of the cell from a modeling perspective. The HT-PEMFC membrane electrode assemblies (MEAs were constructed utilizing an 85 wt. % phosphoric acid doped Advent TPS® membranes for the electrolyte and gas diffusion electrodes (GDEs manufactured by Reactive Spray Deposition Technology (RSDT. MEAs with varying ratios of PTFE binder to carbon support material (I/C ratio were manufactured and their performance at various operating temperatures was recorded. The semi-empirical model derivation was based on the coated film catalyst layer approach and was calibrated to the experimental data by a least squares method. The behavior of important physical parameters as a function of I/C ratio and operating temperature were explored.

  12. Polymer electrolytes: an investigation of some poly (N-propylaziridine)/lithium salt compositions

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, K R; Golder, A J; Knight, J

    1984-04-01

    Poly (N-propylaziridine)/lithium salt compositions were synthesized and their electrical conductivities were measured to assess their suitability as electrolytes in safe, leakproof, high energy-density lithium batteries operating at ambient temperature. The effects on conductivity of temperature, and the nature and concentration of the salt were studied. The salts markedly improve conductivity of the compositions over that of the undoped polymer but they are insufficiently conducting to be considered as battery electrolytes, due possibly to ion pairing. Their creep resistance is also low. Less fluid compositions containing higher molecular weight polymers better able to promote ion separation are more suitable. (ESA)

  13. Development and Characterization of Temperature-resistant Polymer Electrolytes

    DEFF Research Database (Denmark)

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

    1999-01-01

    Acid-doped PBI polymer electrolyte membranes have been developed and characterized for fuel cell applications at temperatures up to 200°C. Electric conductivity as high as 0.13 S/cm is obtained at 160°C at high doping levels. The water osmotic drag coefficient of the polymer electrolyte is found...

  14. Polymer electrolytes: an investigation of some poly (n-propylaziridine)/lithium salt compositions. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, K R; Golder, A J; Knight, J

    1984-04-01

    Some poly(N-propylaziridine)/lithium salt compositions have been synthesized and their electrical conductivities have been measured in order to assess their suitability as electrolytes in safe, leakproof, high energy-density lithium batteries operating at ambient temperature. The effects on conductivity of temperature, and the nature and concentration of the salt have also been studied. The presence of the salts markedly improved the conductivity of the compositions over that of the undoped polymer but they were insufficiently conducting to be considered as battery electrolytes, due possibly to ion-pairing. Their creep resistance was also low. It was concluded that less fluid compositions containing higher molecular weight polymers better able to promote ion separation would be more suitable.

  15. based gel polymer electrolytes

    Indian Academy of Sciences (India)

    (PVdF) as a host polymer, lithium perchlorate (LiClO4), lithium triflate ... TG/DTA studies showed the thermal stability of the polymer electrolytes. .... are observed while comparing pure XRD spectra with .... batteries as its operating temperature is normally in the .... chain ion movements and the conductivity of the polymer.

  16. 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.

  17. Three-dimensional dynamic modelling of Polymer-Electrolyte-Membrane-Fuel-Cell-Systems; Dreidimensionale dynamische Modellierung und Berechnung von Polymer-Elektrolyt-Membran-Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Vath, Andreas

    2008-12-15

    This thesis deals with dynamic and multi-dimensional modelling of Polymer- Electrolyte-Membrane-Fuel-Cells (PEMFC). The developed models include all the different layers of the fuel cell e.g. flow field, gas diffusion layer, catalyst layer and membrane with their particular physical, chemical and electrical characteristics. The simulation results have been verified by detailed measurements performed at the research centre for hydrogen and solar energy in Ulm (ZSW Ulm). The developed three dimensional model describes the time- and spatial-dependent charge and mass transport in a fuel cell. Additionally, this model allows the analysis of critical operating conditions. For example, the current density distribution for different membranes is shown during insufficient humidification which results in local overstraining and degradation. The model also allows to analyse extreme critical operating conditions, e.g. short time breakdown of the humidification. Furthermore, the model shows the available potential of improvement opportunities in power density and efficiency of PEMFC due to optimisation of the gas diffusion layer, the catalyst and membrane. In the second part of the work the application of PEMFC systems for combined heat and power units is described by one-dimensional models for an electrical power range between 1 kW and 5 kW. This model contains the necessary components, e.g. gas processing, humidification, gas supply, fuel cell stack, heat storage, pumps, auxiliary burner, power inverter und additional aggregates. As a main result, it is possible to distinctly reduce the energy demand and the carbon dioxide exhaust for different load profiles. Today the costs for fuel cell systems are considerably higher than that of the conventional electrical energy supply. (orig.)

  18. PEO nanocomposite polymer electrolyte for solid state symmetric

    Indian Academy of Sciences (India)

    Physical and electrochemical properties of polyethylene oxide (PEO)-based nanocomposite solid polymer electrolytes (NPEs) were investigated for symmetric capacitor applications. Nanosize fillers, i.e., Al2O3 and SiO2 incorporated polymer electrolyte exhibited higher ionic conductivity than those with filler-free composites ...

  19. Performance Degradation Tests of Phosphoric Acid Doped Polybenzimidazole Membrane Based High Temperature Polymer Electrolyte Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Zhou, Fan; Araya, Samuel Simon; Grigoras, Ionela

    2015-01-01

    Degradation tests of two phosphoric acid (PA) doped PBI membrane based HT-PEM fuel cells were reported in this paper to investigate the effects of start/stop and the presence of methanol in the fuel to the performance degradation of the HT-PEM fuel cell. Continuous tests with pure dry H2 and meth...

  20. Effect of surface treatment on the interfacial contact resistance and corrosion resistance of Fe–Ni–Cr alloy as a bipolar plate for polymer electrolyte membrane fuel cells

    International Nuclear Information System (INIS)

    Yang, Meijun; Zhang, Dongming

    2014-01-01

    The bipolar plate is an important component of the PEMFC (polymer electrolyte membrane fuel cell) because it supplies the pathway of electron flow between each unit cell. Fe–Ni–Cr alloy is considered as a good candidate material for bipolar plate, but it is limited to use as a bipolar plate due to its high ICR (interfacial contact resistance) and corrosion problem. In order to explore a cost-effective method on surface modification, various chemical and electrochemical treatments are performed on Fe–Ni–Cr alloy to acquire the effect of the surface modification on the ICR and corrosion behavior. The ICR and corrosion resistance of Fe–Ni–Cr alloy can be effectively controlled by the chemical treatment of immersion in the mixed acid solution with 10 vol% HNO 3 , 2 vol% HCl and 1 vol% HF for 10 min at 65 °C and then was placed in 30 vol% HNO 3 solution for 5 min. The chemical treatment is more effective on reducing ICR and improving corrosion resistance than that of electrochemical methods (be carried out in the 2 mol/L H 2 SO 4 solution with the electrical potential from −0.4 V to 0.6 V) for Fe–Ni–Cr alloy as a bipolar plate for polymer electrolyte membrane fuel cells. - Highlights: • The procedure of the surface treatments on Fe–Ni–Cr alloy as bipolar plate was described in detail. • Effects of various surface treatments on the interfacial contact resistivity and corrosion behavior were discussed. • The mechanism of the surface modification was particularly analyzed

  1. Solid polymer electrolytes

    Science.gov (United States)

    Abraham, Kuzhikalail M.; Alamgir, Mohamed; Choe, Hyoun S.

    1995-01-01

    This invention relates to Li ion (Li.sup.+) conductive solid polymer electrolytes composed of poly(vinyl sulfone) and lithium salts, and their use in all-solid-state rechargeable lithium ion batteries. The lithium salts comprise low lattice energy lithium salts such as LiN(CF.sub.3 SO.sub.2).sub.2, LiAsF.sub.6, and LiClO.sub.4.

  2. Localised electrochemical impedance measurements of a polymer electrolyte fuel cell using a reference electrode array to give cathode-specific measurements and examine membrane hydration dynamics

    Science.gov (United States)

    Engebretsen, Erik; Hinds, Gareth; Meyer, Quentin; Mason, Tom; Brightman, Edward; Castanheira, Luis; Shearing, Paul R.; Brett, Daniel J. L.

    2018-04-01

    Advances in bespoke diagnostic techniques for polymer electrolyte fuel cells continue to provide unique insight into the internal operation of these devices and lead to improved performance and durability. Localised measurements of current density have proven to be extremely useful in designing better fuel cells and identifying optimal operating strategies, with electrochemical impedance spectroscopy (EIS) now routinely used to deconvolute the various losses in fuel cells. Combining the two techniques provides another dimension of understanding, but until now each localised EIS has been based on 2-electrode measurements, composed of both the anode and cathode responses. This work shows that a reference electrode array can be used to give individual electrode-specific EIS responses, in this case the cathode is focused on to demonstrate the approach. In addition, membrane hydration dynamics are studied under current load steps from open circuit voltage. A three-stage process is identified associated with an initial rapid reduction in membrane resistance after 10 s of applying a current step, followed by a slower ramp to approximately steady state, which was achieved after ∼250 s. These results support previously published work that has looked at membrane swelling dynamics and reveal that membrane hydration/membrane resistance is highly heterogeneous.

  3. Performance comparison of portable direct methanol fuel cell mini-stacks based on a low-cost fluorine-free polymer electrolyte and Nafion membrane

    International Nuclear Information System (INIS)

    Baglio, V.; Stassi, A.; Modica, E.; Antonucci, V.; Arico, A.S.; Caracino, P.; Ballabio, O.; Colombo, M.; Kopnin, E.

    2010-01-01

    A low-cost fluorine-free proton conducting polymer electrolyte was investigated for application in direct methanol fuel cell (DMFC) mini-stacks. The membrane consisted of a sulfonated polystyrene grafted onto a polyethylene backbone. DMFC operating conditions specifically addressing portable applications, i.e. passive mode, air breathing, high methanol concentration, room temperature, were selected. The device consisted of a passive DMFC monopolar three-cell stack. Two designs for flow-fields/current collectors based on open-flow or grid-like geometry were investigated. An optimization of the mini-stack structure was necessary to improve utilization of the fluorine-free membrane. Titanium-grid current collectors with proper mechanical stiffness allowed a significant increase of the performance by reducing contact resistance even in the case of significant swelling. A single cell maximum power density of about 18 mW cm -2 was achieved with the fluorine-free membrane at room temperature under passive mode. As a comparison, the performance obtained with Nafion 117 membrane and Ti grids was 31 mW cm -2 . Despite the lower performance, the fluorine-free membrane showed good characteristics for application in portable DMFCs especially with regard to the perspectives of significant cost reduction.

  4. Comparison of high-temperature and low-temperature polymer electrolyte membrane fuel cell systems with glycerol reforming process for stationary applications

    International Nuclear Information System (INIS)

    Authayanun, Suthida; Mamlouk, Mohamed; Scott, Keith; Arpornwichanop, Amornchai

    2013-01-01

    Highlights: • PEMFC systems with a glycerol steam reformer for stationary application are studied. • Performance of HT-PEMFC and LT-PEMFC systems is compared. • HT-PEMFC system shows good performance over LT-PEMFC system at a high current density. • HT-PEMFC system with water gas shift reactor shows the highest system efficiency. • Heat integration can improve the efficiency of HT-PEMFC system. - Abstract: A high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) has a major advantage over a low-temperature polymer electrolyte fuel cell (LT-PEMFC) demonstrated by a tolerance to a higher CO content in the hydrogen feed and thus a simpler fuel processing. In this study, a direct comparison between the performance of HT-PEMFC and LT-PEMFC systems integrated with a glycerol steam reformer with and without a water gas shift reactor is shown. Under pure hydrogen operation, the LT-PEMFC performance is superior to the HT-PEMFC. However, the HT-PEMFC system shows good performance over the LT-PEMFC system when operated under high current density and high pressure (3 atm) and using the reformate gas derived from the glycerol processor as fuel. At high current density, the high concentration of CO is the major limitation for the operation of HT-PEMFC system without water gas shift reactor, whereas the LT-PEMFC suffers from CO poisoning and restricted oxygen mass transport. Considering the system efficiency with co-heat and power generation, the HT-PEMFC system with water gas shift reactor shows the highest overall system efficiency (approximately 60%) and therefore one of the most suitable technologies for stationary applications

  5. New Polymer Electrolyte Cell Systems

    Science.gov (United States)

    Smyrl, William H.; Owens, Boone B.; Mann, Kent; Pappenfus, T.; Henderson, W.

    2004-01-01

    PAPERS PUBLISHED: 1. Pappenfus, Ted M.; Henderson, Wesley A.; Owens, Boone B.; Mann, Kent R.; Smyrl, William H. Complexes of Lithium Imide Salts with Tetraglyme and Their Polyelectrolyte Composite Materials. Journal of the Electrochemical Society (2004), 15 1 (2), A209-A2 15. 2. Pappenfus, Ted M.; Henderson, Wesley A.; Owens, Boone B.; Mann, Kent R.; Smyrl, William H. Ionic-liquidlpolymer electrolyte composite materials for electrochemical device applications. Polymeric Materials Science and Engineering (2003), 88 302. 3. Pappenfus, Ted R.; Henderson, Wesley A.; Owens, Boone B.; Mann, Kent R.; and Smyrl, William H. Ionic Conductivity of a poly(vinylpyridinium)/Silver Iodide Solid Polymer Electrolyte System. Solid State Ionics (in press 2004). 4. Pappenfus Ted M.; Mann, Kent R; Smyrl, William H. Polyelectrolyte Composite Materials with LiPFs and Tetraglyme. Electrochemical and Solid State Letters, (2004), 7(8), A254.

  6. Dimensionless numbers and correlating equations for the analysis of the membrane-gas diffusion electrode assembly in polymer electrolyte fuel cells

    Science.gov (United States)

    Gyenge, E. L.

    The Quraishi-Fahidy method [Can. J. Chem. Eng. 59 (1981) 563] was employed to derive characteristic dimensionless numbers for the membrane-electrolyte, cathode catalyst layer and gas diffuser, respectively, based on the model presented by Bernardi and Verbrugge for polymer electrolyte fuel cells [AIChE J. 37 (1991) 1151]. Monomial correlations among dimensionless numbers were developed and tested against experimental and mathematical modeling results. Dimensionless numbers comparing the bulk and surface-convective ionic conductivities, the electric and viscous forces and the current density and the fixed surface charges, were employed to describe the membrane ohmic drop and its non-linear dependence on current density due to membrane dehydration. The analysis of the catalyst layer yielded electrode kinetic equivalents of the second Damköhler number and Thiele modulus, influencing the penetration depth of the oxygen reduction front based on the pseudohomogeneous film model. The correlating equations for the catalyst layer could describe in a general analytical form, all the possible electrode polarization scenarios such as electrode kinetic control coupled or not with ionic and/or oxygen mass transport limitation. For the gas diffusion-backing layer correlations are presented in terms of the Nusselt number for mass transfer in electrochemical systems. The dimensionless number-based correlating equations for the membrane electrode assembly (MEA) could provide a practical approach to quantify single-cell polarization results obtained under a variety of experimental conditions and to implement them in models of the fuel cell stack.

  7. Dimensionless numbers and correlating equations for the analysis of the membrane-gas diffusion electrode assembly in polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Gyenge, E.L. [Department of Chemical and Biological Engineering, The University of British Columbia, 2216 Main Mall, Vancouver, BC (Canada V6T 1Z4)

    2005-12-01

    The Quraishi-Fahidy method [Can. J. Chem. Eng. 59 (1981) 563] was employed to derive characteristic dimensionless numbers for the membrane-electrolyte, cathode catalyst layer and gas diffuser, respectively, based on the model presented by Bernardi and Verbrugge for polymer electrolyte fuel cells [AIChE J. 37 (1991) 1151]. Monomial correlations among dimensionless numbers were developed and tested against experimental and mathematical modeling results. Dimensionless numbers comparing the bulk and surface-convective ionic conductivities, the electric and viscous forces and the current density and the fixed surface charges, were employed to describe the membrane ohmic drop and its non-linear dependence on current density due to membrane dehydration. The analysis of the catalyst layer yielded electrode kinetic equivalents of the second Damkohler number and Thiele modulus, influencing the penetration depth of the oxygen reduction front based on the pseudohomogeneous film model. The correlating equations for the catalyst layer could describe in a general analytical form, all the possible electrode polarization scenarios such as electrode kinetic control coupled or not with ionic and/or oxygen mass transport limitation. For the gas diffusion-backing layer correlations are presented in terms of the Nusselt number for mass transfer in electrochemical systems. The dimensionless number-based correlating equations for the membrane electrode assembly (MEA) could provide a practical approach to quantify single-cell polarization results obtained under a variety of experimental conditions and to implement them in models of the fuel cell stack. (author)

  8. Self-Assembled Polymeric Ionic Liquid-Functionalized Cellulose Nano-crystals: Constructing 3D Ion-conducting Channels Within Ionic Liquid-based Composite Polymer Electrolytes.

    Science.gov (United States)

    Shi, Qing Xuan; Xia, Qing; Xiang, Xiao; Ye, Yun Sheng; Peng, Hai Yan; Xue, Zhi Gang; Xie, Xiao Lin; Mai, Yiu-Wing

    2017-09-04

    Composite polymeric and ionic liquid (IL) electrolytes are some of the most promising electrolyte systems for safer battery technology. Although much effort has been directed towards enhancing the transport properties of polymer electrolytes (PEs) through nanoscopic modification by incorporating nano-fillers, it is still difficult to construct ideal ion conducting networks. Here, a novel class of three-dimensional self-assembled polymeric ionic liquid (PIL)-functionalized cellulose nano-crystals (CNC) confining ILs in surface-grafted PIL polymer chains, able to form colloidal crystal polymer electrolytes (CCPE), is reported. The high-strength CNC nano-fibers, decorated with PIL polymer chains, can spontaneously form three-dimensional interpenetrating nano-network scaffolds capable of supporting electrolytes with continuously connected ion conducting networks with IL being concentrated in conducting domains. These new CCPE have exceptional ionic conductivities, low activation energies (close to bulk IL electrolyte with dissolved Li salt), high Li + transport numbers, low interface resistances and improved interface compatibilities. Furthermore, the CCPE displays good electrochemical properties and a good battery performance. This approach offers a route to leak-free, non-flammable and high ionic conductivity solid-state PE in energy conversion devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Validation of cell voltage and water content in a PEM (polymer electrolyte membrane) fuel cell model using neutron imaging for different operating conditions

    International Nuclear Information System (INIS)

    Salva, J. Antonio; Iranzo, Alfredo; Rosa, Felipe; Tapia, Elvira

    2016-01-01

    This work presents a one dimensional analytical model developed for a 50 cm"2 PEM (polymer electrolyte membrane) fuel cell with five-channel serpentine flow field. The different coupled physical phenomena such as electrochemistry, mass transfer of hydrogen, oxygen and water (two phases) together with heat transfer have been solved simultaneously. The innovation of this work is that the model has been validated with two different variables simultaneously and quantitatively in order to ensure the accuracy of the results. The selected variables are the cell voltage and the water content within the membrane MEA (Membrane Electrode Assembly) and GDL (gas diffusion layers) experimentally measured by means of neutron radiography. The results show a good agreement for a comprehensive set of different operating conditions of cell temperature, pressure, reactants relative humidity and cathode stoichiometry. The analytical model has a relative error less than 3.5% for the value of the cell voltage and the water content within the GDL + MEA for all experiments performed. This result presents a new standard of validation in the state of art of PEM fuel cell modeling where two variables are simultaneously and quantitatively validated with experimental results. The developed analytical model has been used in order to analyze the behavior of the PEM fuel cell under different values of relative humidity. - Highlights: • One dimensional analytical model has been developed for a PEM fuel cell. • The model is validated with two different variables simultaneously. • New standard of validation is proposed.

  10. Radiolytical Preparation of a Poly(Vinylbenzyl Sulfonic Acid)-Grafted FEP Membrane and Characterization as Polymer Electrolytes for Direct Methanol Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Nho, Y -C; Shin, J; Sohn, J -Y; Fei, G [Radiation Research Division for Industry and Environment, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of)

    2012-09-15

    In this study, a novel polymer electrolyte membrane, poly(vinylbenzyl sulfonic acid)-grafted poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP-g-PVBSA), has been successfully prepared by simultaneous irradiation grafting of vinylbenzyl chloride(VBC) monomer onto a FEP film and taking subsequent chemical modification steps to modify the benzyl chloride moiety to the benzyl sulfonic acid moiety. The chemical reactions for the sulfonation were carried out via the formation of thiouronium salt with thiourea, base-catalyzed hydrolysis for the formation of thiol, and oxidation with hydrogen peroxide. Each chemical conversion process was confirmed by FTIR, elemental analysis, and SEM-EDX. A chemical stability study performed with Fenton's reagent (3% H{sub 2}O{sub 2} solution containing 4 ppm of Fe{sup 2+}) at 70 deg. C revealed that FEP-g-PVBSA has a higher chemical stability than the poly(styrene sulfonic acid)-grafted membranes (FEP-g-PSSA). An EDX analysis was also used to observe the cross-sectional distribution behaviors of the hydrophilic sulfonic acid groups and hydrophobic fluorine groups. The characteristics of an ion-exchange capacity (IEC), water and methanol uptake, methanol permeability, and proton conductivity as a function of the degree of grafting were also studied. The IECs and water uptakes of membranes with different degrees of grafting (36-102%) were measured to be in the range of 0.8-1.62 meq/g, and 10-30%, respectively. When the degree of grafting reached 60% the proton conductivity was higher than that of a Nafion (registered) 212 membrane (6.1E-02 S/cm). The methanol permeability and uptake of the FEP-g-PVBSA membrane was significantly lower than that of the Nafion (registered) 212 membrane, and even the degree of grafting reached 102%. (author)

  11. DMFC Performance of Polymer Electrolyte Membranes Prepared from a Graft-Copolymer Consisting of a Polysulfone Main Chain and Styrene Sulfonic Acid Side Chains

    Directory of Open Access Journals (Sweden)

    Nobutaka Endo

    2016-08-01

    Full Text Available Polymer electrolyte membranes (PEMs for direct methanol fuel cell (DMFC applications were prepared from a graft-copolymer (PSF-g-PSSA consisting of a polysulfone (PSF main chain and poly(styrene sulfonic acid (PSSA side chains with various average distances between side chains (Lav and side chain lengths (Lsc. The polymers were synthesized by grafting ethyl p-styrenesulfonate (EtSS on macro-initiators of chloromethylated polysulfone with different contents of chloromethyl (CM groups, and by changing EtSS content in the copolymers by using atom transfer radical polymerization (ATRP. The DMFC performance tests using membrane electrode assemblis (MEAs with the three types of the PEMs revealed that: a PSF-g-PSSA PEM (SF-6 prepared from a graft copolymer with short average distances between side chains (Lav and medium Lsc had higher DMFC performance than PEMs with long Lav and long Lsc or with short Lav and short Lsc. SF-6 had about two times higher PDmax (68.4 mW/cm2 than Nafion® 112 at 30 wt % of methanol concentration. Furthermore, it had 58.2 mW/cm2 of PDmax at 50 wt % of methanol concentration because of it has the highest proton selectivity during DMFC operation of all the PSF-g-PSSA PEMs and Nafion® 112.

  12. Influence of Silica/Sulfonated Polyether-Ether Ketone as Polymer Electrolyte Membrane for Hydrogen Fueled Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Sri Handayani

    2011-12-01

    Full Text Available The operation of non-humidified condition of proton exchange membrane fuel cell (PEMFC using composite sPEEK-silica membrane is reported. Sulfonated membrane of PEEK is known as hydrocarbon polyelectrolyte membrane for PEMFC and direct methanol fuel cell (DMFC. The state of the art of fuel cells is based on the perluorosulfonic acid membrane (Nafion. Nafion has been the most used in both PEMFC and DMFC due to good performance although in low humidified condition showed poor current density. Here we reported the effect of silica in hydrocarbon sPEEK membrane that contributes for a better water management system inside the cell, and showed 0.16 W/cm2 of power density which is 78% higher than that of non-silica modified [Keywords: composite membrane, polyether-ether ketone, silica, proton exchange membrane fuel cell].

  13. Large scale simulation of liquid water transport in a gas diffusion layer of polymer electrolyte membrane fuel cells using the lattice Boltzmann method

    Science.gov (United States)

    Sakaida, Satoshi; Tabe, Yutaka; Chikahisa, Takemi

    2017-09-01

    A method for the large-scale simulation with the lattice Boltzmann method (LBM) is proposed for liquid water movement in a gas diffusion layer (GDL) of polymer electrolyte membrane fuel cells. The LBM is able to analyze two-phase flows in complex structures, however the simulation domain is limited due to heavy computational loads. This study investigates a variety means to reduce computational loads and increase the simulation areas. One is applying an LBM treating two-phases as having the same density, together with keeping numerical stability with large time steps. The applicability of this approach is confirmed by comparing the results with rigorous simulations using actual density. The second is establishing the maximum limit of the Capillary number that maintains flow patterns similar to the precise simulation; this is attempted as the computational load is inversely proportional to the Capillary number. The results show that the Capillary number can be increased to 3.0 × 10-3, where the actual operation corresponds to Ca = 10-5∼10-8. The limit is also investigated experimentally using an enlarged scale model satisfying similarity conditions for the flow. Finally, a demonstration is made of the effects of pore uniformity in GDL as an example of a large-scale simulation covering a channel.

  14. Surface characteristic of chemically converted graphene coated low carbon steel by electro spray coating method for polymer electrolyte membrane fuel cell bipolar plate.

    Science.gov (United States)

    Kim, Jungsoo; Kim, Yang Do; Nam, Dae Geun

    2013-05-01

    Graphene was coated on low carbon steel (SS400) by electro spray coating method to improve its properties of corrosion resistance and contact resistance. Exfoliated graphite was made of the graphite by chemical treatment (Chemically Converted Graphene, CCG). CCG is distributed using dispersing agent, and low carbon steel was coated with diffuse graphene solution by electro spray coating method. The structure of the CCG was analyzed using XRD and the coating layer of surface was analyzed using SEM. Analysis showed that multi-layered graphite structure was destroyed and it was transformed in to fine layers graphene structure. And the result of SEM analysis on the surface and the cross section, graphene layer was uniformly formed with 3-5 microm thickness on the surface of substrate. Corrosion resistance test was applied in the corrosive solution which is similar to the polymer electrolyte membrane fuel cell (PEMFC) stack inside. And interfacial contact resistance (ICR) test was measured to simulate the internal operating conditions of PEMFC stack. As a result of measuring corrosion resistance and contact resistance, it could be confirmed that low carbon steel coated with CCG was revealed to be more effective in terms of its applicability as PEMFC bipolar plate.

  15. Comparison of Numerical and Experimental Studies for Flow-Field Optimization Based on Under-Rib Convection in Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Nguyen Duy Vinh

    2016-10-01

    Full Text Available The flow-field design based on under-rib convection plays an important role in enhancing the performance of polymer electrolyte membrane fuel cells (PEMFCs because it ensures the uniform distribution of the reacting gas and the facilitation of water. This research focused on developing suitable configurations of the anode and cathode bipolar plates to enhance the fuel cell performance based on under-rib convection. The work here evaluated the effects of flow-field designs, including a serpentine flow field with sub channel and by pass and a conventional serpentine flow-field on single-cell performance. Both the experiment and computer simulation indicated that the serpentine flow field with sub channel and by pass (SFFSB configuration enables more effective utilization of the electrocatalysts since it improves reactant transformation rate from the channel to the catalyst layer, thereby dramatically improving the fuel cell performance. The simulation and experimental results indicated that the power densities are increased by up to 16.74% and 18.21%, respectively, when applying suitable flow-field configurations to the anode and cathode bipolar plates. The findings in this are the foundation for enhancing efficient PEMFCs based on flow field design.

  16. Investigation of the effects of process sequence on the contact resistance characteristics of coated metallic bipolar plates for polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Turan, Cabir; Cora, Ömer Necati; Koç, Muammer

    2013-12-01

    In this study, results of an investigation on the effects of manufacturing and coating process sequence on the contact resistance (ICR) of metallic bipolar plates (BPP) for polymer electrolyte membrane fuel cells (PEMFCs) are presented. Firstly, uncoated stainless steel 316L blanks were formed into BPP through hydroforming and stamping processes. Then, these formed BPP samples were coated with three different PVD coatings (CrN, TiN and ZrN) at three different thicknesses (0.1, 0.5 and 1 μm). Secondly, blanks of the same alloy were coated first with the same coatings, thickness and technique; then, they were formed into BPPs of the same shape and dimensions using the manufacturing methods as in the first group. Finally, these two groups of BPP samples were tested for their ICR to reveal the effect of process sequence. ICR tests were also conducted on the BPP plates both before and after exposure to corrosion to disclose the effect of corrosion on ICR. Coated-then-formed BPP samples exhibited similar or even better ICR performance than formed-then-coated BPP samples. Thus, manufacturing of coated blanks can be concluded to be more favorable and worth further investigation in quest of making cost effective BPPs for mass production of PEMFC.

  17. Investigating the effects of gas diffusion layer substrate thickness on polymer electrolyte membrane fuel cell performance via synchrotron X-ray radiography

    International Nuclear Information System (INIS)

    Lee, J.; Chevalier, S.; Banerjee, R.; Antonacci, P.; Ge, N.; Yip, R.; Kotaka, T.; Tabuchi, Y.; Bazylak, A.

    2017-01-01

    Synchrotron X-ray radiography was used to visualize the liquid water accumulation in polymer electrolyte membrane (PEM) fuel cells to compare the impact of carbon substrate thickness on water management. A differential fuel cell with an active area of 0.68 cm 2 and rib/channel width of 0.2 mm was custom-made to provide 1-dimensional (1D) conditions over the active area. The fuel cell with the thin substrate (TGP-H-030) outperformed the fuel cell with the thick substrate (TGP-H-060). The fuel cell with the thinner substrate exhibited a higher limiting current density, less liquid water in the microporous layer (MPL)-substrate transition region, and reduced oxygen transport resistance measured through electrochemical impedance spectroscopy (EIS). The compression behaviour of each GDL was also investigated through two consecutive fuel cell assemblies. The pressure in the second assembly was lower than that for the initial assemblies for both GDLs, and this significant change in assembly pressure was more pronounced for the thinner GDL (TGP-H-030). The resulting interfacial contact between the catalyst layer and the GDL was degraded, which manifested in the microscale displacement of fuel cell materials during operation (detected as a negative liquid water thickness). While the thinner GDL provided superior performance, the long term effects of material deformation may exacerbate a heterogeneous distribution of liquid water that could also impact the performance.

  18. Modeling the Liquid Water Transport in the Gas Diffusion Layer for Polymer Electrolyte Membrane Fuel Cells Using a Water Path Network

    Directory of Open Access Journals (Sweden)

    Dietmar Gerteisen

    2013-09-01

    Full Text Available In order to model the liquid water transport in the porous materials used in polymer electrolyte membrane (PEM fuel cells, the pore network models are often applied. The presented model is a novel approach to further develop these models towards a percolation model that is based on the fiber structure rather than the pore structure. The developed algorithm determines the stable liquid water paths in the gas diffusion layer (GDL structure and the transitions from the paths to the subsequent paths. The obtained water path network represents the basis for the calculation of the percolation process with low calculation efforts. A good agreement with experimental capillary pressure-saturation curves and synchrotron liquid water visualization data from other literature sources is found. The oxygen diffusivity for the GDL with liquid water saturation at breakthrough reveals that the porosity is not a crucial factor for the limiting current density. An algorithm for condensation is included into the model, which shows that condensing water is redirecting the water path in the GDL, leading to an improved oxygen diffusion by a decreased breakthrough pressure and changed saturation distribution at breakthrough.

  19. To immobilize polyethylene glycol-borate ester/lithium fluoride in graphene oxide/poly(vinyl alcohol for synthesizing new polymer electrolyte membrane of lithium-ion batteries

    Directory of Open Access Journals (Sweden)

    Y. F. Huang

    2017-01-01

    Full Text Available Polymer electrolyte membranes (PEMs are potentially applicable in lithium-ion batteries with high safety, low cost and good performance. Here, to take advantages of ionic conductivity and selectivity of borate ester-functionalized small molecules as well as structural properties of polymer nanocomposite, a strategy of immobilizing as-synthesized polyethylene glycol-borate ester/lithium fluoride (B-PEG/LiF in graphene oxide/poly(vinyl alcohol (GO/PVA to prepare a PEM is put forward. Chemical structure of the PEM is firstly characterized by 1H-, 11B- and 19F-nuclear magnetic resonance spectra, and Fourier transform infrared spectroscopy spectra, respectively, and then is further investigated under consideration of the interactions among PVA, B-PEG and LiF components. The immobilization of B-PEG/LiF in PVA-based structure is confirmed. As the interactions within electrolyte components can be further tuned by GO, ionic conductivity (~10–3 S·cm–1, lithium-ion transfer number (~0.49, and thermal (~273 °C/electrochemical (>4 V stabilities of the PEM can be obtained, and the feasibility of PEMs applied in a lithium-ion battery is also confirmed. It is believed that such PEM is a promising candidate as a new battery separator.

  20. Au-MnO{sub 2}/MWNT and Au-ZnO/MWNT as oxygen reduction reaction electrocatalyst for polymer electrolyte membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Imran Jafri, Razack; Sujatha, N.; Ramaprabhu, S. [Alternative Energy and Nanotechnology Laboratory (AENL), Nano Functional Materials Technology Centre (NFMTC), Department of Physics, Indian Institute of Technology Madras, Chennai (India); Rajalakshmi, N. [Center for Fuel Cell Technology (ARCI), Madavakkam, Chennai (India)

    2009-08-15

    Bi-functional catalysts based on Au supported on oxide based nanomaterials for use in fuel cells were evaluated by electrochemical methods for oxygen reduction reaction (ORR) in Polymer Electrolyte Membrane Fuel Cell (PEMFC). Metal oxide coated multi walled carbon nanotubes (MWNTs) (MnO{sub 2}/MWNT and ZnO/MWNT) were prepared by reduction of potassium permanganate and oxidation of Zn powder on MWNT surface respectively. Au-MnO{sub 2}/MWNT and Au-ZnO/MWNT were prepared by chemical reduction of chloroauric acid on MnO{sub 2}/MWNT and ZnO/MWNT. The samples were characterized and linear sweep voltammetric studies were performed in N{sub 2} saturated, O{sub 2} saturated and methanol containing 1 M KOH solution and the results have been discussed. A single fuel cell was also constructed using Au-MnO{sub 2}/MWNT and Au-ZnO/MWNT as ORR electrocatalysts. A maximum power density of 45 mW/cm{sup 2} and 56 mW/cm{sup 2} was obtained with Au-MnO{sub 2}/MWNT and Au-ZnO/MWNT respectively. Additionally, the methanol tolerance of these electrocatalysts has been investigated and results have been discussed. (author)

  1. Structural and morphological changes in supramolecular-structured polymer electrolyte membrane fuel cell on addition of phosphoric acid

    Science.gov (United States)

    Hendrana, S.; Pryliana, R. F.; Natanael, C. L.; Rahayu, I.

    2018-03-01

    Phosphoric acid is one agents used in membrane fuel cell to modify ionic conductivity. Therefore, its distribution in membrane is a key parameter to gain expected conductivity. Efforts have been made to distribute phosphoric acid in a supramolecular-structured membrane prepared with a matrix. To achieve even distribution across bulk of the membrane, the inclusion of the polyacid is carried out under pressurized chamber. Image of scanning electron microscopy (SEM) shows better phosphoric acid distribution for one prepared in pressurized state. It also leads in better performing in ionic conductivity. Moreover, data from differential scanning calorimetry (DSC) indicate that the addition of phosphoric acid is prominent in the change of membrane structure, while morphological changes are captured in SEM images.

  2. Solid polymer electrolyte lithium batteries

    Science.gov (United States)

    Alamgir, Mohamed; Abraham, Kuzhikalail M.

    1993-01-01

    This invention pertains to Lithium batteries using Li ion (Li.sup.+) conductive solid polymer electrolytes composed of solvates of Li salts immobilized in a solid organic polymer matrix. In particular, this invention relates to Li batteries using solid polymer electrolytes derived by immobilizing solvates formed between a Li salt and an aprotic organic solvent (or mixture of such solvents) in poly(vinyl chloride).

  3. Electrospun nanocomposite fibrous polymer electrolyte for secondary lithium battery applications

    International Nuclear Information System (INIS)

    Padmaraj, O.; Rao, B. Nageswara; Jena, Paramananda; Satyanarayana, N.; Venkateswarlu, M.

    2014-01-01

    Hybrid nanocomposite [poly(vinylidene fluoride -co- hexafluoropropylene) (PVdF-co-HFP)/magnesium aluminate (MgAl 2 O 4 )] fibrous polymer membranes were prepared by electrospinning method. The prepared pure and nanocomposite fibrous polymer electrolyte membranes were soaked into the liquid electrolyte 1M LiPF 6 in EC: DEC (1:1,v/v). XRD and SEM are used to study the structural and morphological studies of nanocomposite electrospun fibrous polymer membranes. The nanocomposite fibrous polymer electrolyte membrane with 5 wt.% of MgAl 2 O 4 exhibits high ionic conductivity of 2.80 × 10 −3 S/cm at room temperature. The charge-discharge capacity of Li/LiCoO 2 coin cells composed of the newly prepared nanocomposite [(16 wt.%) PVdF-co-HFP+(5 wt.%) MgAl 2 O 4 ] fibrous polymer electrolyte membrane was also studied and compared with commercial Celgard separator

  4. Single-ion polymer electrolyte membranes enable lithium-ion batteries with a broad operating temperature range.

    Science.gov (United States)

    Cai, Weiwei; Zhang, Yunfeng; Li, Jing; Sun, Yubao; Cheng, Hansong

    2014-04-01

    Conductive processes involving lithium ions are analyzed in detail from a mechanistic perspective, and demonstrate that single ion polymeric electrolyte (SIPE) membranes can be used in lithium-ion batteries with a wide operating temperature range (25-80 °C) through systematic optimization of electrodes and electrode/electrolyte interfaces, in sharp contrast to other batteries equipped with SIPE membranes that display appreciable operability only at elevated temperatures (>60 °C). The performance is comparable to that of batteries using liquid electrolyte of inorganic salt, and the batteries exhibit excellent cycle life and rate performance. This significant widening of battery operation temperatures coupled with the inherent flexibility and robustness of the SIPE membranes makes it possible to develop thin and flexible Li-ion batteries for a broad range of applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Technical assessment of a micro-cogeneration system based on polymer electrolyte membrane fuel cell and fluidized bed autothermal reformer

    International Nuclear Information System (INIS)

    Di Marcoberardino, Gioele; Roses, Leonardo; Manzolini, Giampaolo

    2016-01-01

    Highlights: • Performances of an ATR membrane reactor within a PEM FC micro-CHP system of 5 kWel. • Analysis of two different options for the H_2 permeate side: sweep and vacuum pump. • Optimization of operating conditions in terms of efficiency and membrane area. • Distribution of power and thermal consumptions and losses were discussed in detail. • A sensitivity analysis highlights the relevant design parameters of the CHP system. - Abstract: This work investigates the integration of an autothermal membrane reformer within a micro-CHP system of 5 kWel based on PEM fuel cell. The system modeled is based on a prototype developed within Reforcell European project. The optimization of the micro-CHP system is performed from a thermodynamic point of view aiming at the target of 40% of net electric efficiency and 90% of total system efficiency comparing different configuration and operating conditions. In particular, two hydrogen permeate side options as vacuum or sweep steam are evaluated together with different combination of feed temperature and pressures. A good compromise between electric efficiency (40%) and membrane surface area (0.3 m"2) was obtained for the sweep gas case at reaction side conditions of 8 bar, 600 °C and S/C of 2.5. Higher electric efficiency (40.5%) could be achieved by increasing the membrane surface area. The adoption of a vacuum pump simplifies the reactor design and manufacturing, but reduces the net electric efficiency by about 2% points with a membrane surface area of 0.15 m"2. Finally, the sensitivity analysis highlighted the influence of the main parameters and the design criteria for the definition of the CHP system.

  6. Zero-Gap Alkaline Water Electrolysis Using Ion-Solvating Polymer Electrolyte Membranes at Reduced KOH Concentrations

    DEFF Research Database (Denmark)

    Kraglund, Mikkel Rykær; Aili, David; Jankova Atanasova, Katja

    2016-01-01

    Membranes based on poly(2,2'-(m-phenylene)-5,5-bibenzimidazole) (m-PBI) can dissolve large amounts of aqueous KOH to give electrolyte systems with ion conductivity in a practically useful range. The conductivity of the membrane strongly depends on the concentration of the aqueous KOH phase......, reaching about 10-1 S cm-1 or higher in 15-25 wt% KOH. Herein, m-PBI membranes are systematically characterized with respect to performance and short-term stability as electrolyte in a zero-gap alkaline water electrolyzer at different KOH concentrations. Using plain uncatalyzed nickel foam electrodes......, the cell based on m-PBI outperforms the cell based on the commercially available state-of-the-art diaphragm and reaches a current density of 1500 mA cm-2 at 2.4 V in 20 wt% KOH at 80°C. The cell performance remained stable during two days of operation, though post analysis of the membrane using size...

  7. Effect of microstructure of TiN film on properties as bipolar plate coatings in polymer electrolyte membrane fuel cell prepared by inductively coupled plasma assisted magnetron sputtering

    International Nuclear Information System (INIS)

    Feng, Kai; Li, Zhuguo

    2013-01-01

    As potential application in bipolar plate of polymer electrolyte membrane fuel cell, the microstructure, corrosion resistance and the electrical conductivity of titanium nitride (TiN) and Si doped titanium nitride (Ti 0.9 Si 0.1 N) films deposited by magnetron sputtering with different bias voltages are investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), electrochemical test and four-point probe method, respectively. XRD, SEM and AFM results reveal that the texture and topography of TiN film depend on the bias voltage and incorporation of Si. When the bias voltage is − 20 V and − 30 V, the TiN and Ti 0.9 Si 0.1 N films exhibit a dense (111) plane preferred growth, denser structure and smoother surface topography. The potentiodynamic test results indicate that the TiN and Ti 0.9 Si 0.1 N films have higher chemical inertness and better corrosion resistance. The films can satisfy the requirement of current density for bipolar plate materials. Incorporation of Si element into TiN film makes the passive current density more stable. Four-point probe measurement results show that the resistivity of both TiN and Ti 0.9 Si 0.1 N films reaches minimum when the deposition bias voltage is − 20 V. - Highlights: • Dense TiN and Ti 0.9 Si 0.1 N films are deposited by magnetron sputtering. • Preferred growth orientation of TiN depends on the bias voltage and Si doping. • TiN and Ti 0.9 Si 0.1 N films have excellent corrosion resistance. • Surface conductivity of TiN and Ti 0.9 Si 0.1 N films evolves with bias voltage

  8. An experimental study on the cathode humidification and evaporative cooling of polymer electrolyte membrane fuel cells using direct water injection method at high current densities

    International Nuclear Information System (INIS)

    Hwang, Seong Hoon; Kim, Min Soo

    2016-01-01

    Highlights: • Proposal of a cathode humidification and evaporative cooling system for PEM fuel cells. • An external-mixing air-assist atomizer is used to produce a very fine water spray. • The system is effective in both cathode humidification and stack cooling. • Increased water flow rate improves stack performance and evaporative cooling capacity. • At a given water flow rate, lower stack temperatures cause greater humidification effect. - Abstract: Humidification and cooling are critical issues in enhancing the efficiency and durability of polymer electrolyte membrane fuel cells (PEMFCs). However, existing humidifiers and cooling systems have the disadvantage that they must be quite large to achieve adequate PEMFC performance. In this study, to eliminate the need for a bulky humidifier and to lighten the cooling load of PEMFCs, a cathode humidification and evaporative cooling system using an external-mixing air-assist atomizer was developed and its performance was investigated. The atomization performance of the nozzle was analyzed experimentally under various operating conditions with minimal changes in the system design. Experiments with a five-cell PEMFC stack with an active area of 250 cm"2 were carried out to analyze the effects of various parameters (such as the operating temperature, current density, and water injection flow rate) on the evaporation of injected water for humidification and cooling performances. The experimental results demonstrate that the direct water injection method proposed in this study is quite effective in cathode humidification and stack cooling in PEM fuel cells at high current densities. The stack performance was improved by humidification effect and the coolant temperature at the stack outlet decreased by evaporative cooling effect.

  9. Investigations on an advanced power system based on a high temperature polymer electrolyte membrane fuel cell and an organic Rankine cycle for heating and power production

    International Nuclear Information System (INIS)

    Perna, Alessandra; Minutillo, Mariagiovanna; Jannelli, Elio

    2015-01-01

    Energy systems based on fuel cells technology can have a strategic role in the range of small-size power generation for the sustainable energy development. In order to enhance their performance, it is possible to recover the “waste heat” from the fuel cells, for producing or thermal power (cogeneration systems) or further electric power by means of a bottoming power cycle (combined systems). In this work an advanced system based on the integration between a HT-PEMFC (high temperature polymer electrolyte membrane fuel cell) power unit and an ORC (organic Rankine cycle) plant, has been proposed and analysed as suitable energy power plant for supplying electric and thermal energies to a stand-alone residential utility. The system can operate both as cogeneration system, in which the electric and thermal loads are satisfied by the HT-PEMFC power unit and as electric generation system, in which the low temperature heat recovered from the fuel cells is used as energy source in the ORC plant for increasing the electric power production. A numerical model, able to characterize the behavior and to predict the performance of the HT-PEMFC/ORC system under different working conditions, has been developed by using the AspenPlus™ code. - Highlights: • The advanced plant can operate both as CHP system and as electric generation system. • The performance prediction of the integrated system is carried out by numerical modeling. • ORC thermodynamic optimization is carried out by a sensitivity analysis. • Thermal coupling between the HT-PEMC system and the ORC plant is analyzed. • Results are very promising in the field of the distributed generation

  10. Preliminary study of application of Moringa oleifera resin as polymer electrolyte in DSSC solar cells

    Science.gov (United States)

    Saehana, Sahrul; Darsikin, Muslimin

    2016-04-01

    This study reports the preliminary study of application of Moringa oleifera resin as polymer electrolyte in dye-sensitized solar cell (DSSC). We found that polymer electrolyte membrane was formed by using solution casting methods. It is observed that polymer electrolyte was in elastic form and it is very potential to application as DSSC component. Performance of DSSC which employing Moringa oleifera resin was also observed and photovoltaic effect was found.

  11. Control and Experimental Characterization of a Methanol Reformer for a 350 W High Temperature Polymer Electrolyte Membrane Fuel Cell system

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Jensen, Hans-Christian Becker

    , i.e. cathode and anode gas flows and temperature by using mass flow controllers and controlled heaters. Using this system the methanol reformer is characterized in its different operating points, both steady-state but also dynamically. Methanol steam reforming is a well known process, and provides...... and burner and the behaviour of the CO concentration of the reformate gas....... the high temperature waste gas from a cathode air cooled 45 cell HTPEM fuel cell stack. The MEAs used are BASF P2100 which use phosphoric acid doped polybenzimidazole type membranes; an MEA with high CO tolerance and no complex humidity requirements. The methanol reformer used is integrated into a compact...

  12. Preparation and Characterization of PVA Alkaline Solid Polymer Electrolyte with Addition of Bamboo Charcoal

    Directory of Open Access Journals (Sweden)

    Lidan Fan

    2018-04-01

    Full Text Available Natural bamboo charcoal (BC powder has been developed as a novel filler in order to further improve performances of the polyvinyl alcohol (PVA-based alkaline solid polymer electrolyte (ASPE by solution casting method. X-ray diffraction patterns of composite polymer electrolyte with BC revealed the decrease in the degree of crystallinity with increasing content of BC. Scanning electron microscopy images showed pores on a micrometer scale (average diameter about 2 μm distributed inside and on the surface of the membranes, indicating a three-dimension network formed in the polymer framework. The ionic conductivity was measured by the alternating-current (AC impedance method, and the highest conductivity value of 6.63 × 10−2 S·cm−1 was obtained with 16 wt % of BC content and mKOH:mPVA = 2:1.5 at 30 °C. The contents of BC and KOH could significantly influence the conductivity. The temperature dependence of the bulk electrical conductivity displayed a combination of Arrhenius nature, and the activation energy for the ion in polymer electrolyte has been calculated. The electrochemical stability window of the electrolyte membrane was over 1.6 V. The thermogravimetric analysis curves showed that the degradation temperatures of PVA-BC-KOH ASPE membranes shifted toward higher with adding BC. A simple nickel-hydrogen battery containing PVA-BC-KOH electrolyte membrane was assembled with a maximum discharge capacity of 193 mAh·g−1.

  13. Preparation and Characterization of PVA Alkaline Solid Polymer Electrolyte with Addition of Bamboo Charcoal.

    Science.gov (United States)

    Fan, Lidan; Wang, Mengyue; Zhang, Zhen; Qin, Gang; Hu, Xiaoyi; Chen, Qiang

    2018-04-26

    Natural bamboo charcoal (BC) powder has been developed as a novel filler in order to further improve performances of the polyvinyl alcohol (PVA)-based alkaline solid polymer electrolyte (ASPE) by solution casting method. X-ray diffraction patterns of composite polymer electrolyte with BC revealed the decrease in the degree of crystallinity with increasing content of BC. Scanning electron microscopy images showed pores on a micrometer scale (average diameter about 2 μm) distributed inside and on the surface of the membranes, indicating a three-dimension network formed in the polymer framework. The ionic conductivity was measured by the alternating-current (AC) impedance method, and the highest conductivity value of 6.63 × 10 −2 S·cm −1 was obtained with 16 wt % of BC content and m KOH : m PVA = 2:1.5 at 30 °C. The contents of BC and KOH could significantly influence the conductivity. The temperature dependence of the bulk electrical conductivity displayed a combination of Arrhenius nature, and the activation energy for the ion in polymer electrolyte has been calculated. The electrochemical stability window of the electrolyte membrane was over 1.6 V. The thermogravimetric analysis curves showed that the degradation temperatures of PVA-BC-KOH ASPE membranes shifted toward higher with adding BC. A simple nickel-hydrogen battery containing PVA-BC-KOH electrolyte membrane was assembled with a maximum discharge capacity of 193 mAh·g −1 .

  14. FY 2000 report on the results of the regional consortium R and D project - Regional consortium energy R and D field. First year report. R and D of new composite polymer electrolyte for battery; 2000 nendo chiiki consortium kenkyu kaihatsu jigyo - chiiki consortium energy kenkyu kaihatsu bun'ya. Denchiyo shinki fukugo polymer kei denkaishitsu no kenkyu kaihatsu (dai 1 nendo) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The development was proceeded with of new composite polymer electrolyte for Li secondary battery. The ultimate target of the development using this electrolyte is to get Li secondary battery markedly improved in safety/reliability which works at low temperature and controls thermal runaway. The composite polymer base electrolyte is composed of high molecular weight polyethylene oxide copolymer, ethylene oxide oligomer and Li salt, and it is finally cross-linked by heat or light. Studies were made in the following 6 fields: 1) R and D of the creation and optimization of new composite polymer electrolyte; 2) R and D of the commercialization of composite polymer electrolyte battery; 3) R and D on the safety of composite polymer electrolyte; 4) study of the synthesis of new electrolyte and catalytic activity of electrolyte-electrode interface; 5) R and D on polymer/oligomer composite electrolyte; and 6) comprehensive investigational research. (NEDO)

  15. In-situ experimental characterization of the clamping pressure effects on low temperature polymer electrolyte membrane electrolysis

    DEFF Research Database (Denmark)

    Al Shakhshir, Saher; Cui, Xiaoti; Frensch, Steffen Henrik

    2017-01-01

    as a gas with the circulating water. The effects of clamping pressure (Pc) on the LT-PEME cell performance, polarization resistances, and hydrogen and water crossover through the membrane, and hydrogen and oxygen production rate are studied. A 50 cm2 active area LT-PEME cell designed and manufactured......-PEME splits water into hydrogen and oxygen when the voltage is applied between anode and cathode. Electrical current forces the positively charged ions to migrate to negatively charged cathode through PEM, where hydrogen is produced. Meanwhile, oxygen is produced at the anode side electrode and escapes...... in house is utilized in this work. Higher Pc has shown higher cell performance this refers to lower ohmic and activation resistances. Water crossover from anode to cathode is slightly decreased at higher Pc resulting in a slight decrease in hydrogen crossover from cathode to anode. Also, the percentage...

  16. Influence of local porosity and local permeability on the performances of a polymer electrolyte membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Akiki, Tilda [Universite Saint Esprit Kaslik (Lebanon); Universite de Technologie de Belfort-Montbeliard, FCLAB Institute for Research on Fuel Cell Systems, 90010 Belfort (France); Charon, Willy; Iltchev, Marie-Christine; Kouta, Raed [Universite de Technologie de Belfort-Montbeliard, FCLAB Institute for Research on Fuel Cell Systems, 90010 Belfort (France); Accary, Gilbert [Universite Saint Esprit Kaslik (Lebanon)

    2010-08-15

    In the literature, many models and studies focused on the steady-state aspect of fuel cell systems while their dynamic transient behavior is still a wide area of research. In the present paper, we study the effects of mechanical solicitations on the performance of a proton exchange membrane fuel cell as well as the coupling between the physico-chemical phenomena and the mechanical behavior. We first develop a finite element method to analyze the local porosity distribution and the local permeability distribution inside the gas diffusion layer induced by different pressures applied on deformable graphite or steel bipolar plates. Then, a multi-physical approach is carried out, taking into account the chemical phenomena and the effects of the mechanical compression of the fuel cell, more precisely the deformation of the gas diffusion layer, the changes in the physical properties and the mass transfer in the gas diffusion layer. The effects of this varying porosity and permeability fields on the polarization and on the power density curves are reported, and the local current density is also investigated. Unlike other studies, our model accounts for a porosity field that varies locally in order to correctly simulate the effect of an inhomogeneous compression in the cell. (author)

  17. Validity of two-phase polymer electrolyte membrane fuel cell models with respect to the gas diffusion layer

    Science.gov (United States)

    Ziegler, C.; Gerteisen, D.

    A dynamic two-phase model of a proton exchange membrane fuel cell with respect to the gas diffusion layer (GDL) is presented and compared with chronoamperometric experiments. Very good agreement between experiment and simulation is achieved for potential step voltammetry (PSV) and sine wave testing (SWT). Homogenized two-phase models can be categorized in unsaturated flow theory (UFT) and multiphase mixture (M 2) models. Both model approaches use the continuum hypothesis as fundamental assumption. Cyclic voltammetry experiments show that there is a deterministic and a stochastic liquid transport mode depending on the fraction of hydrophilic pores of the GDL. ESEM imaging is used to investigate the morphology of the liquid water accumulation in the pores of two different media (unteflonated Toray-TGP-H-090 and hydrophobic Freudenberg H2315 I3). The morphology of the liquid water accumulation are related with the cell behavior. The results show that UFT and M 2 two-phase models are a valid approach for diffusion media with large fraction of hydrophilic pores such as unteflonated Toray-TGP-H paper. However, the use of the homgenized UFT and M 2 models appears to be invalid for GDLs with large fraction of hydrophobic pores that corresponds to a high average contact angle of the GDL.

  18. Synthesis and characterizations of novel polymer electrolytes

    Science.gov (United States)

    Chanthad, Chalathorn

    Polymer electrolytes are an important component of many electrochemical devices. The ability to control the structures, properties, and functions of polymer electrolytes remains a key subject for the development of next generation functional polymers. Taking advantage of synthetic strategies is a promising approach to achieve the desired chemical structures, morphologies, thermal, mechanical, and electrochemical properties. Therefore, the major goal of this thesis is to develop synthetic methods for of novel proton exchange membranes and ion conductive membranes. In Chapter 2, new classes of fluorinated polymer- polysilsesquioxane nanocomposites have been designed and synthesized. The synthetic method employed includes radical polymerization using the functional benzoyl peroxide initiator for the telechelic fluorinated polymers with perfluorosulfonic acids in the side chains and a subsequent in-situ sol-gel condensation of the prepared triethoxylsilane-terminated fluorinated polymers with alkoxide precursors. The properties of the composite membranes have been studied as a function of the content and structure of the fillers. The proton conductivity of the prepared membranes increases steadily with the addition of small amounts of the polysilsesquioxane fillers. In particular, the sulfopropylated polysilsesquioxane based nanocomposites display proton conductivities greater than Nafion. This is attributed to the presence of pendant sulfonic acids in the fillers, which increases ion-exchange capacity and offers continuous proton transport channels between the fillers and the polymer matrix. The methanol permeability of the prepared membranes has also been examined. Lower methanol permeability and higher electrochemical selectivity than those of Nafion have been demonstrated in the polysilsesquioxane based nanocomposites. In Chapter 3, the synthesis of a new class of ionic liquid-containing triblock copolymers with fluoropolymer mid-block and imidazolium methacrylate

  19. Gel polymer electrolytes for batteries

    Science.gov (United States)

    Balsara, Nitash Pervez; Eitouni, Hany Basam; Gur, Ilan; Singh, Mohit; Hudson, William

    2014-11-18

    Nanostructured gel polymer electrolytes that have both high ionic conductivity and high mechanical strength are disclosed. The electrolytes have at least two domains--one domain contains an ionically-conductive gel polymer and the other domain contains a rigid polymer that provides structure for the electrolyte. The domains are formed by block copolymers. The first block provides a polymer matrix that may or may not be conductive on by itself, but that can soak up a liquid electrolyte, thereby making a gel. An exemplary nanostructured gel polymer electrolyte has an ionic conductivity of at least 1.times.10.sup.-4 S cm.sup.-1 at 25.degree. C.

  20. 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.

  1. Advances in Ceramic Supports for Polymer Electrolyte Fuel Cells

    Directory of Open Access Journals (Sweden)

    Oran Lori

    2015-08-01

    Full Text Available Durability of catalyst supports is a technical barrier for both stationary and transportation applications of polymer-electrolyte-membrane fuel cells. New classes of non-carbon-based materials were developed in order to overcome the current limitations of the state-of-the-art carbon supports. Some of these materials are designed and tested to exceed the US DOE lifetime goals of 5000 or 40,000 hrs for transportation and stationary applications, respectively. In addition to their increased durability, the interactions between some new support materials and metal catalysts such as Pt result in increased catalyst activity. In this review, we will cover the latest studies conducted with ceramic supports based on carbides, oxides, nitrides, borides, and some composite materials.

  2. Preparation and application of PVDF-HFP composite polymer electrolytes in LiNi0.5Co0.2Mn0.3O2 lithium-polymer batteries

    International Nuclear Information System (INIS)

    Yang, Chun-Chen; Lian, Zuo-Yu; Lin, S.J.; Shih, Jeng-Ywan; Chen, Wei-Houng

    2014-01-01

    Graphical abstract: - Highlights: • PVDF-HFP/SBA15 membrane and NCM cathode material were prepared for Li ion battery. • SBA15 fillers can trap more liquid electrolytes to enhance the ionic conductivity. • Modified fillers with functional groups play a key role in reducing impedance. • LiNi 0.5 Co 0.2 Mn 0.3 O 2 polymer battery showed excellent electrochemical performance. - Abstract: This study reports the preparation of a composite polymer electrolyte for application in LiNi 0.5 Co 0.2 Mn 0.3 O 2 lithium-polymer batteries. Poly(vinylidiene fluoride-hexafluoropropylene) (denoted as PVDF-HFP) was used as the polymer host and mesoporous modified-silica fillers (denoted as m-SBA15) used as the solid plasticizer were added into the polymer matrix. The characteristic properties of the composite polymer membranes were examined using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and an AC impedance method. The discharge capacities of LiNi 0.5 Co 0.2 Mn 0.3 O 2 polymer batteries with a PE separator, pure PVDF-HFP polymer membrane, or a PVDF-HFP/10 wt.%m-SBA15 composite at 0.1 C were determined to be 155.5, 159.5, and 198.6 mAh g −1 , respectively. The LiNi 0.5 Co 0.2 Mn 0.3 O 2 polymer battery containing the PVDF-HFP/10 wt.%m-SBA15 composite achieved discharge capacities of 194, 170, 161, 150, 129, 115, and 87 mAh g −1 at 0.1, 0.2, 0.5, 1, 3, 5, and 10 C, respectively. The lithium-polymer battery demonstrated a high coulomb efficiency of ca. 99%. The PVDF-HFP/m-SBA15 composite membrane is a strong candidate for application in LiNi 0.5 Co 0.2 Mn 0.3 O 2 lithium-polymer batteries

  3. In situ quantification of the in-plane water content in the Nafion {sup registered} membrane of an operating polymer-electrolyte membrane fuel cell using {sup 1}H micro-magnetic resonance imaging experiments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Mingtao; Feindel, Kirk W.; Bergens, Steven H.; Wasylishen, Roderick E. [Department of Chemistry, University of Alberta, E3-24 Gunning/Lemieux Chemistry Center, Edmonton, Alberta (Canada)

    2010-11-01

    Spatial, quantitative, and temporal information regarding the water content distribution in the transverse-plane between the catalyst layers of an operating polymer-electrolyte membrane fuel cell (PEMFC) is essential to develop a fundamental understanding of water dynamics in these systems. We report {sup 1}H micro-magnetic resonance imaging (MRI) experiments that measure the number of water molecules per SO{sub 3}H group, {lambda}, within a Nafion {sup registered} -117 membrane between the catalyst stamps of a membrane-electrode assembly, MEA. The measurements were made both ex situ, and inside a PEMFC operating on hydrogen and oxygen. The observed {sup 1}H MRI T{sub 2} relaxation time of water in the PEM was measured for several known values of {lambda}. The signal intensity of the images was then corrected for T{sub 2} weighting to yield proton density-weighted images, thereby establishing a calibration curve that correlates the {sup 1}H MRI density-weighted signal with {lambda}. Subsequently, the calibration curve was used with proton density weighted (i.e., T{sub 2}-corrected) signal intensities of transverse-plane {sup 1}H MRI images of water in the PEM between the catalyst stamps of an operating PEMFC to determine {lambda} under various operational conditions. For example, the steady state, transverse-plane {lambda} was 9 {+-} 1 for a PEMFC operating at {proportional_to}26.4 mW cm{sup -2} ({proportional_to}20.0 mA, {proportional_to}0.661 V, 20 C, flow rates of the dry H{sub 2}(g) and O{sub 2}(g) were 5.0 and 2.5 mL min{sup -1}, respectively). (author)

  4. Development and characterization of acid-doped polybenzimidazole/sulfonated polysulfone blend polymer electrolytes for fuel cells

    DEFF Research Database (Denmark)

    Hasiotis, C.; Li, Qingfeng; Deimede, V.

    2001-01-01

    Polymeric membranes from blends of sulfonated polysulfones (SPSF) and polybenzimidazole (PBI) doped with phosphoric acid were developed as potential high-temperature polymer electrolytes for fuel cells and other electrochemical applications. The water uptake and acid doping of these polymeric...... membranes were investigated. Ionic conductivity of the membranes was measured in relation to temperature, acid doping level, sulfonation degree of SPSF, relative humidity, and blend composition. The conductivity of SPSF was of the order of 10/sup -3/ S cm/sup -1/. In the case of blends of PBI and SPSF...

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

    KAUST Repository

    Hu, Xian-Lei; Hou, Gao-Ming; Zhang, Ming-Qiu; Rong, Min-Zhi; Ruan, Wen-Hong; Giannelis, Emmanuel P.

    2012-01-01

    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

  6. 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....

  7. Preparation and Characterization of PVA Alkaline Solid Polymer Electrolyte with Addition of Bamboo Charcoal

    OpenAIRE

    Lidan Fan; Mengyue Wang; Zhen Zhang; Gang Qin; Xiaoyi Hu; Qiang Chen

    2018-01-01

    Natural bamboo charcoal (BC) powder has been developed as a novel filler in order to further improve performances of the polyvinyl alcohol (PVA)-based alkaline solid polymer electrolyte (ASPE) by solution casting method. X-ray diffraction patterns of composite polymer electrolyte with BC revealed the decrease in the degree of crystallinity with increasing content of BC. Scanning electron microscopy images showed pores on a micrometer scale (average diameter about 2 μm) distributed inside a...

  8. Characterization of polymer electrolytes for fuel cell applications

    International Nuclear Information System (INIS)

    Zawodzinski, T.A. Jr.; Springer, T.E.; Uribe, F.; Gottesfeld, S.

    1992-01-01

    We review here our recent work on polymer electrolyte fuel cells emphasizing membrane transport issues. Transport parameters measured at 30 degrees C for several available perfluorosulfonic acid membranes are compared. The water sorption characteristics, diffusion coefficient of water, electroosmotic drag, and pretonic conductivity were determined for Nafion reg-sign 117, Membrane C, and Dow XUS 13204.10 Developmental Fuel Cell Membrane. The diffusion coefficient and conductivity of each of these membranes were determined as functions of membrane water content. Data on water sorption and conductivity are reported for an experimental membrane which is a modified form of Nafion. Contact angle measurements indicate that the surface of a perfluorosulfonic acid membrane exposed to water vapor is quite hydrophobic, even in the presence of saturated water vapor. Modeling of water distribution in PEFC's based on the uptake and transport data shows that membrane thickness contributes in a nonlinear fashion to performance in PEM fuel cells. Finally, some work currently underway is discussed

  9. 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.

  10. Calibrating the X-ray attenuation of liquid water and correcting sample movement artefacts during in operando synchrotron X-ray radiographic imaging of polymer electrolyte membrane fuel cells.

    Science.gov (United States)

    Ge, Nan; Chevalier, Stéphane; Hinebaugh, James; Yip, Ronnie; Lee, Jongmin; Antonacci, Patrick; Kotaka, Toshikazu; Tabuchi, Yuichiro; Bazylak, Aimy

    2016-03-01

    Synchrotron X-ray radiography, due to its high temporal and spatial resolutions, provides a valuable means for understanding the in operando water transport behaviour in polymer electrolyte membrane fuel cells. The purpose of this study is to address the specific artefact of imaging sample movement, which poses a significant challenge to synchrotron-based imaging for fuel cell diagnostics. Specifically, the impact of the micrometer-scale movement of the sample was determined, and a correction methodology was developed. At a photon energy level of 20 keV, a maximum movement of 7.5 µm resulted in a false water thickness of 0.93 cm (9% higher than the maximum amount of water that the experimental apparatus could physically contain). This artefact was corrected by image translations based on the relationship between the false water thickness value and the distance moved by the sample. The implementation of this correction method led to a significant reduction in false water thickness (to ∼0.04 cm). Furthermore, to account for inaccuracies in pixel intensities due to the scattering effect and higher harmonics, a calibration technique was introduced for the liquid water X-ray attenuation coefficient, which was found to be 0.657 ± 0.023 cm(-1) at 20 keV. The work presented in this paper provides valuable tools for artefact compensation and accuracy improvements for dynamic synchrotron X-ray imaging of fuel cells.

  11. Novel inorganic materials for polymer electrolyte and alkaline fuel cells

    Science.gov (United States)

    Tadanaga, Kiyoharu

    2012-06-01

    Inorganic materials with high ionic conductivity must have big advantages for the thermal and long term stability when the materials are used as the electrolyte of fuel cells. In the present paper, novel ionic conductive inorganic materials for polymer electrolyte fuel cells (PEFCs) and all solid state alkaline fuel cells (AFCs) that have been developed by our group have been reviewed. PEFCs which can operate in temperature range from 100 to 200 °C are intensively studied because of some advantages such as reduction of CO poisoning of Pt catalyst and acceleration of electrode reactions. We showed that the fuel cells using the composite membranes prepared from phosphosilicate gel powder and polyimide precursor can operate in the temperature range from 30 to 180 °C. We also found that the inorganic-organic hybrid membranes with acid-base pairs from 3-aminopropyl triethoxy silane and H2SO4 or H3PO4 show high proton conductivity under dry atmosphere, and the membranes are thermally stable at intermediate temperatures. On the other hand, because the use of noble platinum is the serious problem for the commercialization of PEFCs and because oxidation reactions are usually faster than those of acid-type fuel cells, alkaline type fuel cells, in which a nonplatinum catalyst can be used, are attractive. Recently, we have proposed an alkaline-type direct ethanol fuel cell (DEFC) using a natural clay electrolyte with non-platinum catalysts. So-called hydrotalcite clay, Mg-Al layered double hydroxide intercalated with CO32- (Mg-Al CO32- LDH), has been proved to be a hydroxide ion conductor. An alkalinetype DEFC using Mg-Al CO32- LDH as the electrolyte and aqueous solution of ethanol and potassium hydroxide as a source of fuel exhibited excellent electrochemical performance.

  12. Influence of artificially aged gas diffusion layers on the water management of polymer electrolyte membrane fuel cells analyzed with in-operando synchrotron imaging

    International Nuclear Information System (INIS)

    Arlt, Tobias; Klages, Merle; Messerschmidt, Matthias; Scholta, Joachim; Manke, Ingo

    2017-01-01

    The influence of artificial ageing of gas diffusion layers (GDLs) on the cell performance was investigated using high resolution synchrotron radiography. State-of-the-art GDLs of the type SIGRACET ® SGL 25BC were aged for 0 h, 16 h and 24 h in a hydrogen peroxide solution before they were assembled in the fuel cells. In-operando radiographic measurements were combined with voltage and contact angle measurements. Correlations between applied ageing conditions, GDL water saturation and cell performance were revealed. Hereby, all cell operating conditions were tested several times to estimate the reproducibility of in-operando radiographic fuel cell measurements. Water films at the GDL-membrane and at the GDL-flow field interfaces were found and attributed to MPL cracks and large pores in the GDL structure. The combination of these cracks and pores are assumed to play a crucial role for blocked gas paths, leading to an undersupply with reactants and an increased humidification of the membrane. It is shown that water agglomerations directly impact the membrane resistance. We assume that the hydrophobicity of the fibers inside the GDL is more important for the cell performance than water agglomerations at the membrane-GDL interface. - Highlights: • Influence of ageing of gas diffusion layers on cell performance was investigated. • Cell performance decreased using artificially aged GDLs. • Performance decrease correlated to altered water distribution. • Reproducibility of water thickness measurements with synchrotron imaging.

  13. New Fabrication Strategies for Polymer Electrolyte Batteries

    National Research Council Canada - National Science Library

    Shriver, D

    1997-01-01

    .... The objective of this research was to fabricate lithium-polymer batteries by techniques that may produce a thin electrolyte and cathode films and with minimal contamination during fabrication. One such technique, ultrasonic spray was used. Another objective of this research was to test lithium cells that incorporate the new polymer electrolytes and polyelectrolytes.

  14. Synthesis and electrochemical characterization of hybrid membrane Nafion-SiO2 for application as polymer electrolyte in PEM fuel cell

    International Nuclear Information System (INIS)

    Dresch, Mauro Andre

    2009-01-01

    In this work, the effect of sol-gel synthesis parameters on the preparation and polarization response of Nafion-SiO 2 hybrids as electrolytes for proton exchange membrane fuel cells (PEMFC) operating at high temperatures (130 degree C) was evaluated. The inorganic phase was incorporated in a Nafion matrix with the following purposes: to improve the Nafion water uptake at high temperatures (> 100 degree C); to increase the mechanical strength of Nafion and; to accelerate the electrode reactions. The hybrids were prepared by an in-situ incorporation of silica into commercial Nafion membranes using an acid-catalyzed sol-gel route. The effects of synthesis parameters, such as catalyst concentration, sol-gel solvent, temperature and time of both hydrolysis and condensation reactions, and silicon precursor concentration (Tetraethyl orthosilicate - TEOS), were evaluated as a function on the incorporation degree and polarization response. Nafion-SiO 2 hybrids were characterized by gravimetry, thermogravimetric analysis (TGA), scanning electron microscopy and X-ray dispersive energy (SEM-EDS), electrochemical impedance spectroscopy (EIS), and X-ray small angle scattering (SAXS). The hybrids were tested as electrolyte in single H 2 /O 2 fuel cells in the temperature range of 80 - 130 degree C and at 130 degree C and reduced relative humidity (75% and 50%). Summarily, the hybrid performance showed to be strongly dependent on the synthesis parameters, mainly, the type of alcohol and the TEOS concentration. (author)

  15. Electrode structures of polymer-electrolyte fuel cells (PEFC). An electron microscopy approach to the characterization of the electrode structure of polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Scheiba, Frieder

    2009-01-28

    catalyst and catalyst support, but that it forms a complex structure consisting of fiber and film like structures in the pores of the electrode. In addition, the EF-TEM result delivered a strong indication for the infiltration of catalyst agglomerates by the polymer electrolyte. Furthermore, a new concept for the investigation of multi-component structures, consisting of the membrane, electrodes and gas di1usion layers (GDL) was developed. Thus it was possible to provide evidence for the intrusion of individual carbon fibers from the GDL into the electrode. In addition the influence of GDL structure on delamination of the electrode could be demonstrated. Another part of the work deals with the characterization of a novel platinum catalyst deposited on hydrous ruthenium oxide coated carbon nanotubes (CNT), which was developed in close cooperation with a Chinese partner at Tsinghua University (Beijing). (orig.)

  16. In-situ experimental characterization of the clamping pressure effects on low temperature polymer electrolyte membrane electrolysis International Journal of Hydrogen Energy

    DEFF Research Database (Denmark)

    Al Shakhshir, Saher; Cui, Xiaoti; Frensch, Steffen Henrik

    2017-01-01

    as a gas with the circulating water. The effects of clamping pressure (Pc) on the LT-PEME cell performance, polarization resistances, and hydrogen and water crossover through the membrane, and hydrogen and oxygen production rate are studied. A 50 cm2 active area LT-PEME cell designed and manufactured......-PEME splits water into hydrogen and oxygen when the voltage is applied between anode and cathode. Electrical current forces the positively charged ions to migrate to negatively charged cathode through PEM, where hydrogen is produced. Meanwhile, oxygen is produced at the anode side electrode and escapes...... in house is utilized in this work. Higher Pc has shown higher cell performance this refers to lower ohmic and activation resistances. Water crossover from anode to cathode is slightly decreased at higher Pc resulting in a slight decrease in hydrogen crossover from cathode to anode. Also, the percentage...

  17. Energy efficiency enhancement of ethanol electrooxidation on Pd-CeO(2)/C in passive and active polymer electrolyte-membrane fuel cells.

    Science.gov (United States)

    Bambagioni, Valentina; Bianchini, Claudio; Chen, Yanxin; Filippi, Jonathan; Fornasiero, Paolo; Innocenti, Massimo; Lavacchi, Alessandro; Marchionni, Andrea; Oberhauser, Werner; Vizza, Francesco

    2012-07-01

    Pd nanoparticles have been generated by performing an electroless procedure on a mixed ceria (CeO(2))/carbon black (Vulcan XC-72) support. The resulting material, Pd-CeO(2)/C, has been characterized by means of transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and X-ray diffraction (XRD) techniques. Electrodes coated with Pd-CeO(2)/C have been scrutinized for the oxidation of ethanol in alkaline media in half cells as well as in passive and active direct ethanol fuel cells (DEFCs). Membrane electrode assemblies have been fabricated using Pd-CeO(2)/C anodes, proprietary Fe-Co cathodes, and Tokuyama anion-exchange membranes. The monoplanar passive and active DEFCs have been fed with aqueous solutions of 10 wt% ethanol and 2 M KOH, supplying power densities as high as 66 mW cm(-2) at 25 °C and 140 mW cm(-2) at 80 °C. A comparison with a standard anode electrocatalyst containing Pd nanoparticles (Pd/C) has shown that, at even metal loading and experimental conditions, the energy released by the cells with the Pd-CeO(2)/C electrocatalyst is twice as much as that supplied by the cells with the Pd/C electrocatalyst. A cyclic voltammetry study has shown that the co-support ceria contributes to the remarkable decrease of the onset oxidation potential of ethanol. It is proposed that ceria promotes the formation at low potentials of species adsorbed on Pd, Pd(I)-OH(ads), that are responsible for ethanol oxidation. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. TEMPO addition into pre-irradiated fluoropolymers and living-radical graft polymerization of styrene for preparation of polymer electrolyte membranes

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, Shin-ichi, E-mail: sawada.shinnichi@jaea.go.j [Conducting Polymer Materials Research Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Suzuki, Akihiro; Terai, Takayuki [Department of Nuclear Engineering and Management, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Maekawa, Yasunari, E-mail: maekawa.yasunari@jaea.go.j [Conducting Polymer Materials Research Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2010-04-15

    We prepared proton exchange membranes (PEMs) by 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO)-mediated living-radical graft polymerization (LRGP) of styrene into fluoropolymer films and subsequent sulfonation. Poly(vinylidene fluoride) (PVDF) and poly(ethylene-co-tetrafluoroethylene) (ETFE) films were first irradiated and then treated with TEMPO solutions in various solvents. TEMPO addition was confirmed by the test of styrene grafting into TEMPO-treated films at 60 deg. C, at which the LRGP never proceeds. This test enabled us to differentiate the LRGP from the conventional graft polymerization. In order to gain a deep insight about TEMPO-addition reaction, the TEMPO-penetration behavior into the base polymer films was examined by a permeation experiment and computer simulation. Xylene and dioxane were appropriate solvents for the complete introduction of TEMPO into PVDF and ETFE films, respectively. Then, the LRGP of styrene was performed based on the fully TEMPO-capped films at 125 deg. C with various solvents. By using an alcoholic solvent, the degree of grafting was enhanced and it reached a maximum of 38%. This grafted film was sulfonated to prepare a PEM showing an ion exchange capacity of 2.2 meq/g and proton conductivity of 1.6x10{sup -1} S/cm.

  19. 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)

  20. 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.

  1. Novel Stable Gel Polymer Electrolyte: Toward a High Safety and Long Life Li-Air Battery.

    Science.gov (United States)

    Yi, Jin; Liu, Xizheng; Guo, Shaohua; Zhu, Kai; Xue, Hailong; Zhou, Haoshen

    2015-10-28

    Nonaqueous Li-air battery, as a promising electrochemical energy storage device, has attracted substantial interest, while the safety issues derived from the intrinsic instability of organic liquid electrolytes may become a possible bottleneck for the future application of Li-air battery. Herein, through elaborate design, a novel stable composite gel polymer electrolyte is first proposed and explored for Li-air battery. By use of the composite gel polymer electrolyte, the Li-air polymer batteries composed of a lithium foil anode and Super P cathode are assembled and operated in ambient air and their cycling performance is evaluated. The batteries exhibit enhanced cycling stability and safety, where 100 cycles are achieved in ambient air at room temperature. The feasibility study demonstrates that the gel polymer electrolyte-based polymer Li-air battery is highly advantageous and could be used as a useful alternative strategy for the development of Li-air battery upon further application.

  2. Solid polymer electrolyte fuel cells

    International Nuclear Information System (INIS)

    Giorgi, L.; Pozio, A.

    1995-05-01

    The report summarizes the state of art of systems for energy production in electrical vehicles, looking into the general characteristics of electrodes and membranes. The water and thermal balance of the cell in relation to operative conditions, the pressure and temperature influence on the performance are examined. Special emphasis is given to the electrode characteristics-fabrication techniques and assembly of membrane electrodes. The problems related to the oxygen reduction kinetics at the cathode are examined, in relation to the fabrication techniques and to operative conditions of the cells. Finally, the possible alternative catalyzers for anode and cathode are reviewed

  3. Characterizations of Chitosan-Based Polymer Electrolyte Photovoltaic Cells

    International Nuclear Information System (INIS)

    Buraidah, M.H.; Teo, L.P.; Majid, S.R.; Yahya, R.; Taha, R.M.; Arof, A.K.

    2010-01-01

    The membranes 55 wt.% chitosan-45 wt.% NH4I, 33 wt.% chitosan-27 wt.% NH4I-40 wt.% EC, and 27.5 wt.% chitosan-22.5 wt.%?NH4I-50 wt.% buthyl-methyl-imidazolium-iodide (BMII) exhibit conductivity of 3.73 x 10-7, 7.34x10-6, and 3.43x10-5 S cm -1 , respectively, at room temperature. These membranes have been used in the fabrication of solid-state solar cells with configuration ITO/TiO 2 /polymer electrolyte membrane/ITO. It is observed that the short-circuit current density increases with conductivity of the electrolyte. The use of anthocyanin pigment obtained by solvent extraction from black rice and betalain from the callus of Celosia plumosa also helps to increase the short-circuit current.

  4. A QuaternaryPoly(ethylene carbonate)-Lithium Bis(trifluoromethanesulfonyl)imide-Ionic Liquid-Silica Fiber Composite Polymer Electrolyte for Lithium Batteries

    International Nuclear Information System (INIS)

    Kimura, Kento; Matsumoto, Hidetoshi; Hassoun, Jusef; Panero, Stefania; Scrosati, Bruno; Tominaga, Yoichi

    2015-01-01

    Highlights: • A quaternary PEC-LiTFSI-Pyr 14 TFSI-Silica fiber electrolyte was prepared by a solvent casting method. • Both electrochemical and mechanical properties were improved by the presence of the Silica fiber. • The electrolyte showed a t Li+ value of 0.36 with an anodic stability extended up to 4.5 V vs. Li/Li + . • A prototype Li/LiFePO 4 polymer cell delivered a discharge capacity of about 100 mAh g −1 (75 °C, C/15). - Abstract: Poly(ethylene carbonate) (PEC) is known as an alternating copolymer derived from carbon dioxide (CO 2 ) and an epoxide as monomers. Here, we describe a new quaternary PEC-based composite electrolyte containing lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt, N-n-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (Pyr 14 TFSI) ionic liquid, and an electrospun silica (SiO 2 ) fiber (SiF) with a submicron diameter in view of its possible applications in solid-state Li polymer batteries. A free-standing electrolyte membrane is prepared by a solvent casting method. The Pyr 14 TFSI ionic liquid enhances the ionic conductivity of the electrolyte as a result of its plasticizing effect. The electrochemical properties, such as ionic conductivity and Li transference number (t Li+ ), as well as mechanical strength of the electrolyte, are further improved by the SiF. We show that the quaternary electrolyte has a conductivity of the order of 10 −7 S cm −1 at ambient temperature and a high t Li+ value of 0.36 with an excellent flexibility. A prototype Li polymer cell using LiFePO 4 as a cathode material is assembled and tested. We demonstrate that this battery delivers a reversible charge-discharge capacity close to 100 mAh g −1 at 75 °C and C/15 rate. We believe that this work may pave the road to utilize CO 2 as a carbon source for highly-demanded, functional battery materials in future

  5. Bipolar plates for polymer electrolyte membrane fuel cells made of thermal and electrical high conductivity thermoplastics. Formulation, production, characterization and application; Bipolarplatten fuer Polymerelektrolytmembran-Brennstoffzellen aus thermisch und elektrisch hochleitfaehigen thermoplastischen Kunststoffen. Rezeptierung, Herstellung, Charakterisierung und Anwendung

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, Ralf Leonhard

    2008-07-01

    The upcoming lack of primary energy sources and the need of reducing the anthropogenic climate change led to increased research activities in the field of Fuel Cells (FC) technology within the last ten years in Europe, the USA and Japan. Especially the automotive industry is highly interested in developing zero emission cars as a replacement of nowadays cars within the next twenty years. Not only for mobile applications the Polymer Electrolyte Membrane Fuel Cell systems (PEM-FC systems) is the focus of research and development. Also stationary (PEM-) FC applications seem to be more and more interesting for a decentralized energy supply, producing electricity and heat (Vaillant FC-Systems, Bosch/Junkers). For this purpose, system miniaturizing and weight reduction (70-90 wt-% of the stack itself is due to bipolar- and endplate) is not that essential as it is for mobile appliance, resulting in earlier commercial market introduction of these systems within the next few years. Not only the weight reduction of the FC-stack itself, but also the cost cutting of its components is vital for the economic success of this technology. The three most expensive components of the stack are the perfluorsulfonated ion conducting Membranen (PEM: Nafion, Ashai, Ashai glass), the noble metal catalyst (Platinum and/or Ruthenium) and the Bipolar Plate (BPP). The moulding processes (injection and/or compression moulding) of polymer materials allow highly integrated, tool reduced mass production of tailored stack components like the BP, the endplate, cell frame and peripheral components. The objective of this thesis is to describe the development of an conductive functionalised material suitable for moulding BPP, to investigate compounding optimisation methods (DOE) and evaluate the best fit parameters, to analyse the rheological behaviour of these highly filled compounds, to discuss suitable polymer related manufacturing processes like hot pressing, injection moulding and profile

  6. Electrochemistry Study on PVC-LiClO4 Polymer Electrolyte Supported by Bengkulu Natural Bentonite for Lithium Battery

    Directory of Open Access Journals (Sweden)

    Ghufira

    2012-04-01

    Full Text Available In this research bentonite was used as filler to produce polymer electrolyte (PVCLiClO4. Some weight variation of bentonite have been made by addition, such as 0% wt/wt; 5% wt/wt ; 10% wt/wt ; 15% wt/wt ; 20% wt/wt ; and 25% wt/wt of bentonite to the mixture of 0,5 gramof PVC and 0,125 gram of LiClO4. Ionic conductivity of polymer electrolyte was tested using impedance spectroscopy. The result of the research was showed that a mixture of PVCBentonite(10% wt/wt-LiClO4 gives the highest ionic conductivity (4,86 x 10-3 S.Cm-1. This result indicated that the presence of natural bentonite can be used as a filler in the current composite polymer electrolyte and can increase the ionic conductivity of the polymer electrolyte.

  7. 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

  8. Quantum dot doped solid polymer electrolyte for device application

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pramod K.; Kim, Kang Wook; Rhee, Hee-Woo [Department of Chemical and Biomolecular Engineering, Sogang University, Mapo-Gu, Seoul 121-742 (Korea)

    2009-06-15

    ZnS capped CdSe quantum dots embedded in PEO:KI:I{sub 2} polymer electrolyte matrix have been synthesized and characterized for dye sensitized solar cell (DSSC) application. The complex impedance spectroscopy shows enhance in ionic conductivity ({sigma}) due to charges provide by quantum dots (QD) while AFM affirm the uniform distribution of QD into polymer electrolyte matrix. Cyclic voltammetry revealed the possible interaction between polymer electrolyte, QD and iodide/iodine. The photovoltaic performances of the DSSC containing quantum dots doped polymer electrolyte was also found to improve. (author)

  9. Zinc polymer electrolytes in battery systems

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, W.P.; Latham, R.J.; Linford, R.G.; Vickers, S.L. (Dept. of Chemistry, School of Applied Sciences, De Montfort Univ., Leicester (United Kingdom))

    1994-06-01

    We have previously reported results of our studies of structure-conductivity relationships for polymer electrolytes of the form PEO[sub n][center dot]ZnX[sub 2]. In this paper we report the results of investigations of battery systems based on these electrolytes. Results will be presented for OCV and discharge curves for loaded cells of the type: Zn/polymer electrolyte/MnO[sub 2]. We are particularly interested in the speciation between oxidation states of manganese as a function of the degree of cell discharge, and have carried out determinations by chemical methods based on polarography. Preliminary studies indicate the presence of Mn[sup II] in cells discharged at various rates. The discharge times for a series of optimised cells show an exponential decrease with increasing load. This is consistent with a low electrolyte conductivity and less than ideal cathode conductivity, which leads to an increased 'front face' reaction with increasing load

  10. Positron annihilation lifetime study of Nafion/titanium dioxide nano-composite membranes

    Science.gov (United States)

    Lei, M.; Wang, Y. J.; Liang, C.; Huang, K.; Ye, C. X.; Wang, W. J.; Jin, S. F.; Zhang, R.; Fan, D. Y.; Yang, H. J.; Wang, Y. G.

    2014-01-01

    Positron annihilation lifetime (PAL) technique is applied for investigation of size and number density of free volumes in Nafion/TiO2-nanoparticles composite membrane. The proton transporting ability is correlated with the properties of free volume inside the membrane. It is revealed that composite membrane with 5 wt% of TiO2 nano-fillers exhibits good electrochemical performance under reduced humidity and it can be saturated with water at relative humidity of 50%, under which ionic clusters and proton transporting channels are formed, indicating that composite membranes with 5 wt% of TiO2 nano-fillers are effective electrolyte for fuel cells operated at reduced humidification levels. The results suggest that PAL can be a powerful tool for elucidating the relationship between microstructure and ion transport in polymer electrolyte membranes.

  11. A.C. impedance, XRD, DSC, SEM and charge/discharge studies on Al2O3, TiO2, SiO2 dispersoid LiPF6/PVC/PVdF-co-HFP composite polymer electrolytes by phase inversion

    Science.gov (United States)

    Vickraman, P.; Gopukumar, S.

    2017-07-01

    The PVC/PVdF-co-HFP composite polymer electrolyte membranes (CPEMs) by varying blend ratios 1:1, 1:2, and 2:1 with fixed content of Al2O3, TiO2 and SiO2 having soaked in 0.5 M LiPF6 in EC/DEC (1:1) v/v) have been prepared by phase inversion. CPEMs of higher ionic conductivity (not dependent on electrolyte uptake as observed in our study) ASA4 (3.61×10-4 Scm-1), TSA3 (1.53×10-4 Scm-1), and SSA3 (4.81×10-4 Scm-1) have been only chosen for XRD, DSC, SEM and electrochemical studies. In XRD, crystalline peaks (phases) of PVdF have been noted with/without change in intensity as well as FWHM which correspond to type of filler interaction with host matrix. In DSC, it is observed that shifts in baseline, melting endotherms, and area under the endotherms indicating the thermal hist ory of PVC (Tg = 82 ° C) and melting of VdF crystallites varied with nature of the filler dispersoid. In SEM, the coagulated fibrils of the polymer coiled with the sponge like structure has been mapped. The charge/discharge studies are carried out on these CPEMs at C/10 rate in the voltage range 2.8 V - 4.2 V, and it is noted that the TSA3 showed better cycling performance with good capacity retention i.e., 50 cycles with 66% capacity retention than ASA4 of 28 cycles with 65% and SSA3 of 5 cycles with 56%. In the present study Coulombic efficiency is concerned only for first cycle and it is noted that the TSA3 showed 71% than 66% and 62% respectively for SSA3 and ASA4.

  12. Nanocomposite polymer electrolyte based on whisker or microfibrils polyoxyethylene nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Alloin, Fannie, E-mail: fannie.alloin@lepmi.grenoble-inp.f [LEPMI, Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, Grenoble-INP-UJF-CNRS, UMR 5631, BP 75, 38041 Grenoble Cedex 9 (France); D' Aprea, Alessandra [Laboratoire de Rheologie, Grenoble-INP-UJF, UMR 5520, BP 53, 38041 Grenoble Cedex 9 (France); LEPMI, Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, Grenoble-INP-UJF-CNRS, UMR 5631, BP 75, 38041 Grenoble Cedex 9 (France); Ecole Internationale du Papier, de la communication imprimee et des Biomateriaux, PAGORA- Grenoble-INP, BP 65, 38402 Saint Martin d' Heres Cedex (France); Kissi, Nadia El [Laboratoire de Rheologie, Grenoble-INP-UJF, UMR 5520, BP 53, 38041 Grenoble Cedex 9 (France); Dufresne, Alain [Ecole Internationale du Papier, de la communication imprimee et des Biomateriaux, PAGORA- Grenoble-INP, BP 65, 38402 Saint Martin d' Heres Cedex (France); Bossard, Frederic [Laboratoire de Rheologie, Grenoble-INP-UJF, UMR 5520, BP 53, 38041 Grenoble Cedex 9 (France)

    2010-07-15

    Nanocomposite polymer electrolytes composed of high molecular weight poly(oxyethylene) PEO as a matrix, LiTFSI as lithium salt and ramie, cotton and sisal whiskers with high aspect ratio and sisal microfibrils (MF), as reinforcing phase were prepared by casting-evaporation. The morphology of the composite electrolytes was investigated by scanning electron microscopy and their thermal behavior (characteristic temperatures, degradation temperature) were investigated by thermogravimetric analysis and differential scanning calorimetry. Nanocomposite electrolytes based on PEO reinforced by whiskers and MF sisal exhibited very high mechanical performance with a storage modulus of 160 MPa at high temperature. A weak decrease of the ionic conductivity was observed with the incorporation of 6 wt% of whiskers. The addition of microfibrils involved a larger decrease of the conductivity. This difference may be associated to the more restricted PEO mobility due to the addition of entangled nanofibers.

  13. 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.

  14. Synthesis and characterization of aminated perfluoro polymer electrolytes

    Science.gov (United States)

    Page-Belknap, Zachary Stephan Glenn

    Polymer electrolytes have been developed for use in anion exchange membrane fuel cells for years. However, due to the highly corrosive environment within these fuel cells, poor chemical stability of the polymers and low ion conductivity have led to high development costs and thus prevention from widespread commercialization. The work in this study aims to provide a solution to these problems through the synthesis and characterization of a novel polymer electrolyte. The 800 EW 3M PFSA sulfonyl fluoride precursor was aminated with 3-(dimethylamino)-1-propylamine to yield a functional polymer electrolyte following quaternization, referred to in this work as PFSa-PTMa. 1 M solutions of LiPF6, HCL, KOH, NaOH, CsOH, NaHCO3 and Na2CO3 were used to exchange the polymer to alternate counterion forms. Chemical structure analysis was performed using both FT and ATR infrared spectroscopy to confirm sulfonyl fluoride replacement and the absence of sulfonic acid sites. Mechanical testing of the polymer, following counterion exchange with KOH, at saturated conditions and 60 ºC exhibited a tensile strength of 13 +/- 2.0 MPa, a Young's modulus of 87 +/- 16 MPa and a degree of elongation reaching 75% +/- 9.1%, which indicated no mechanical degradation following exposure to a highly basic environment. Conductivities of the polymer in the Cl- and OH- counterion forms at saturated conditions and 90 ºC were observed at 26 +/- 8.0 mS cm-1 and 1.1 +/- 0.1 mS cm-1, respectively. OH- conductivities were slightly above those observed for CO32- and HCO 3- counterions at the same conditions, 0.63 +/- 0.18 and 0.66 +/- 0.21 mS cm-1 respectively. The ion exchange capacity (IEC) of the polymer in the Cl- counterion form was measured via titration at 0.57 meq g-1 which correlated to 11.2 +/- 0.10 water molecules per ion site when at 60ºC and 95% relative humidity. The IEC of the polymer in the OH- counterion form following titration expressed nearly negligible charge density, less than 0.01 meq

  15. CO tolerance of polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Gubler, L; Scherer, G G; Wokaun, A [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Reformed methanol can be used as a fuel for polymer electrolyte fuel cells instead of pure hydrogen. The reformate gas contains mainly H{sub 2}, CO{sub 2} in the order of 20% and low levels of CO in the order of 100 ppm. CO causes severe voltage losses due to poisoning of the anode catalyst. The effect of CO on cell performance was investigated at different CO levels up to 100 ppm. Various options to improve the CO tolerance of the fuel cell were assessed thereafter, of which the injection of a few percents of oxygen into the fuel feed stream proved to be most effective. By mixing 1% of oxygen with hydrogen containing 100 ppm CO, complete recovery of the cell performance could be attained. (author) 2 figs., 2 tabs., 3 refs.

  16. High Temperature Polymer Electrolyte Fuel Cells

    DEFF Research Database (Denmark)

    Fleige, Michael

    This thesis presents the development and application of electrochemical half-cell setups to study the catalytic reactions taking place in High Temperature Polymer Electrolyte Fuel Cells (HTPEM-FCs): (i) a pressurized electrochemical cell with integrated magnetically coupled rotating disk electrode...... oxidation of ethanol is in principle a promising concept to supply HTPEM-FCs with a sustainable and on large scale available fuel (ethanol from biomass). However, the intermediate temperature tests in the GDE setup show that even on Pt-based catalysts the reaction rates become first significant...... at potentials, which approach the usual cathode potentials of HTPEM-FCs. Therefore, it seems that H3PO4-based fuel cells are not much suited to efficiently convert ethanol in accordance with findings in earlier research papers. Given that HTPEM-FCs can tolerate CO containing reformate gas, focusing research...

  17. Performance comparison of low and high temperature polymer electrolyte membrane fuel cells. Experimental examinations, modelling and numerical simulation; Leistungsvergleich von Nieder- und Hochtemperatur-Polymerelektrolytmembran-Brennstoffzellen. Experimentelle Untersuchungen, Modellierung und numerische Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Loehn, Helmut

    2010-11-03

    The experimental part of this thesis essentially comprises the performance comparison of low temperature (LT) - polymer electrolyte membrane fuel cells (PEMFCs) on basis of Nafion {sup registered} and high temperature (HT)- PEMFCs on basis of Polybenzimidazol (PBI)/phosphoric acid (H{sub 3}PO{sub 4}). The performance characteristic of commercially available Nafion {sup registered} - LT - (E-TEK-Series 12 W) and PBI/H{sub 3}PO{sub 4} - HT -(Celtec P 1000) membrane electrode assemblies (MEAs) were examined with a single cell in dependence of cell temperature (LT-MEA: 50 - 80 C, HT-MEA: 120 - 190 C), anode and cathode pressure (1 - 3 bar), stoichiometry of gas supply streams and relative humidity (only LT-MEA). Because of the same active cell area of both MEAs (45.16 cm{sup 2}) and the fact, that the flow field for the gas distribution of the test cell can be used universally, the performance tests with both MEA-types could be carried out with the same single test cell. When comparing the performance of both MEAs under similar test conditions - except increased temperature and deactivated humidification of the HT-MEA - at 0.7 A/cm{sup 2} with both MEA-types nearly equal performance densities of 0.3 - 0.45 W/cm{sup 2} can be reached. Since there is no liquid process water present in the HT-MEA the operation is not limited by concentration losses; therefore the HT-MEA can be operated in a wider range with higher current densities and because of the not required water management the operation of the HT-MEA is essentially simplified. Further advantages of the HT-MEA exist in the relative high tolerance against the catalyst poison carbon monoxide - the operation with reformat gas and hydrogen rich gases is facilitated - and an improved heat management because of the elevated operation temperature. However, a disadvantage of the Celtec-P-1000-MEA exists in the degradation at deep temperatures. At operating conditions, in which liquid process water is present, there is the

  18. The effect of microwave drying on polymer electrolyte conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Latham, R.J. (Dept. of Chemistry, De Montfort Univ., Gateway, Leicester (United Kingdom)); Linford, R.G. (Dept. of Chemistry, De Montfort Univ., Gateway, Leicester (United Kingdom)); Pynenburg, R.A.J. (Dept. of Chemistry, De Montfort Univ., Gateway, Leicester (United Kingdom))

    1993-03-01

    The morphology and conductivity of polymer electrolytes based on PEO are often substantially modified by the presence of water. A number of different approaches have commonly been used to eliminate water from polymer electrolyte films. The work reported here extends our earlier investigations of the use of microwaves for the rapid drying of solvent cast polymer electrolyte films. Films of PEO[sub n]:NiBr[sub 2] and PEO[sub n]:ZnCl[sub 2] have been prepared by normal casting techniques and then studied using EXAFS, DSC and ac conductivity measurements. (orig.)

  19. New Solid Polymer Electrolytes for Improved Lithium Batteries

    Science.gov (United States)

    Hehemann, David G.

    2002-01-01

    The objective of this work was to identify, synthesize and incorporate into a working prototype, next-generation solid polymer electrolytes, that allow our pre-existing solid-state lithium battery to function better under extreme conditions. We have synthesized polymer electrolytes in which emphasis was placed on the temperature-dependent performance of these candidate electrolytes. This project was designed to produce and integrate novel polymer electrolytes into a lightweight thin-film battery that could easily be scaled up for mass production and adapted to different applications.

  20. Truly quasi-solid-state lithium cells utilizing carbonate free polymer electrolytes on engineered LiFePO_4

    International Nuclear Information System (INIS)

    Nair, Jijeesh R.; Cíntora-Juárez, Daniel; Pérez-Vicente, Carlos; Tirado, José L.; Ahmad, Shahzada; Gerbaldi, Claudio

    2016-01-01

    Highlights: • Carbonate free truly quasi-solid-state polymer electrolytes for lithium batteries. • Simple and easy up scalable preparation by solvent free thermal curing. • LiFePO_4 cathode engineered by PEDOT:PSS interphase at the current collector. • Direct polymerization over the engineered electrode surface in one pot. • Stable lithium polymer cells operating in a wide temperature range. - Abstract: Stable and safe functioning of a Li-ion battery is the demand of modern generation. Herein, we are demonstrating the application of an in-situ free radical polymerisation process (thermal curing) to fabricate a polymer electrolyte that possesses mechanical robustness, high thermal stability, improved interfacial and ion transport characteristics along with stable cycling at ambient conditions. The polymer electrolyte is obtained by direct polymerization over the electrode surface in one pot starting from a reactive mixture comprising an ethylene oxide-based dimethacrylic oligomer (BDM), dimethyl polyethylene glycol (DPG) and lithium salt. Furthermore, an engineered cathode is used, comprising a LiFePO_4/PEDOT:PSS interface at the current collector that improves the material utilization at high rates and mitigates the corrosive effects of LiTFSI on aluminium current collector. The lithium cell resulting from the newly elaborated multiphase assembly of the composite cathode with the DPG-based carbonate-free polymer electrolyte film exhibits excellent reversibility upon prolonged cycling at ambient as well as elevated temperatures, which is found to be superior compared to previous reports on uncoated electrodes with polymer electrolytes.

  1. Recent advances in solid polymer electrolytes for lithium batteries

    Institute of Scientific and Technical Information of China (English)

    Qingqing Zhang; Kai Liu; Fei Ding; Xingjiang Liu

    2017-01-01

    Solid polymer electrolytes are light-weight,flexible,and non-flammable and provide a feasible solution to the safety issues facing lithium-ion batteries through the replacement of organic liquid electrolytes.Substantial research efforts have been devoted to achieving the next generation of solid-state polymer lithium batteries.Herein,we provide a review of the development of solid polymer electrolytes and provide comprehensive insights into emerging developments.In particular,we discuss the different molecular structures of the solid polymer matrices,including polyether,polyester,polyacrylonitrile,and polysiloxane,and their interfacial compatibility with lithium,as well as the factors that govern the properties of the polymer electrolytes.The discussion aims to give perspective to allow the strategic design of state-of-the-art solid polymer electrolytes,and we hope it will provide clear guidance for the exploration of high-performance lithium batteries.

  2. Ionic-Liquid-Based Polymer Electrolytes for Battery Applications.

    Science.gov (United States)

    Osada, Irene; de Vries, Henrik; Scrosati, Bruno; Passerini, Stefano

    2016-01-11

    The advent of solid-state polymer electrolytes for application in lithium batteries took place more than four decades ago when the ability of polyethylene oxide (PEO) to dissolve suitable lithium salts was demonstrated. Since then, many modifications of this basic system have been proposed and tested, involving the addition of conventional, carbonate-based electrolytes, low molecular weight polymers, ceramic fillers, and others. This Review focuses on ternary polymer electrolytes, that is, ion-conducting systems consisting of a polymer incorporating two salts, one bearing the lithium cation and the other introducing additional anions capable of plasticizing the polymer chains. Assessing the state of the research field of solid-state, ternary polymer electrolytes, while giving background on the whole field of polymer electrolytes, this Review is expected to stimulate new thoughts and ideas on the challenges and opportunities of lithium-metal batteries. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Novel, Solvent-Free, Single Ion Conductive Polymer Electrolytes

    National Research Council Canada - National Science Library

    Florjanczyk, Zbigniew

    2008-01-01

    This project report concerns studies on the synthesis of new polymer electrolytes for application in lithium and lithium-ion batteries characterized by limited participation of anions in the transport...

  4. Synthesis of new solid polymer electrolyte and actuator based on PEDOT/NBR/ionic liquid

    Science.gov (United States)

    Cho, M. S.; Seo, H. J.; Nam, J. D.; Choi, H. R.; Koo, J. C.; Lee, Y.

    2006-03-01

    The conducting polymer actuator was presented. The solid polymer electrolyte based on nitrile rubber (NBR) activated with different ionic liquids was prepared. The three different grades of NBR films were synthesized by emulsion polymerization with different amount of acrylonitrile, 23, 35, and 40 mol. %, respectively. The effect of acrylonitrile content on the ionic conductivity and dielectric constant of solid polymer electrolytes was characterized. A conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), was synthesized on the surface of the NBR layer by using a chemical oxidation polymerization technique, and room temperature ionic liquids (RTIL) based on imidazolium salts, e.g. 1-butyl-3-methyl imidazolium X [where X= BF 4 -, PF 6 -, (CF 3SO II) IIN -], were absorbed into the composite film. The effects of the anion size of the ionic liquids on the displacement of the actuator were examined. The displacement increased with increasing the anion-size of the ionic liquids.

  5. Cross-Linked Solid Polymer Electrolyte for All-Solid-State Rechargeable Lithium Batteries

    International Nuclear Information System (INIS)

    Ben youcef, Hicham; Garcia-Calvo, Oihane; Lago, Nerea; Devaraj, Shanmukaraj; Armand, Michel

    2016-01-01

    Semi-interpenetrated network Solid Polymer Electrolytes (SPEs) were fabricated by UV-induced cross-linking of poly(ethyleneglycol) diacrylate (PEGDA) and divinylbenzene (DVB) within a poly(ethyleneoxide) (PEO) matrix (M v = 5 × 10 6 g mol −1 ), comprising lithium bis(trifluoromethanesulfonyl)imide salt (LiTFSI), at a molar ratio of EO:Li ∼ 30:1. The influence of the DVB content on the final SPE properties was investigated in detail. An increase of DVB concentration resulted in self-standing polymer electrolytes. The DVB cross-linker incorporation was found to decrease the crystallinity of the PEO matrix from 34% to 23%, with a decrease in the melting temperature (T m ) of the membrane from 50 °C to 34 °C. Moreover, the influence of the DVB concentration on the ionic conductivity was determined for polymer electrolytes with 0, 10, 20 and 45% DVB from room temperature (RT) to 80 °C. The resulting SPEs showed a high electrochemical stability of 4.3 V as well as practical conductivity values exceeding 10 −4 S cm −1 at 70 °C. Cycling performance of these semi-interpenetrated SPE’s have been shown with a Li metal polymer battery and all solid -state Li sulphur battery.

  6. Chitosan-gold-Lithium nanocomposites as solid polymer electrolyte.

    Science.gov (United States)

    Begum, S N Suraiya; Pandian, Ramanathaswamy; Aswal, Vinod K; Ramasamy, Radha Perumal

    2014-08-01

    Lithium micro batteries are emerging field of research. For environmental safety biodegradable films are preferred. Recently biodegradable polymers have gained wide application in the field of solid polymer electrolytes. To make biodegradable polymers films plasticizers are usually used. However, use of plasticizers has disadvantages such as inhomogenities in phases and mechanical instability that will affect the performance of Lithium micro batteries. We have in this research used gold nanoparticles that are environmentally friendly, instead of plasticizers. Gold nanoparticles were directly template upon chitosan membranes by reduction process so as to enhance the interactions of Lithium with the polymer. In this article, for the first time the characteristics of Chitosan-gold-Lithium nanocomposite films are investigated. The films were prepared using simple solution casting technique. We have used various characterization tools such as Small Angle Neutron Scattering (SANS), XRD, FTIR, Raman, FESEM, and AFM, Light scattering, Dielectric and electrical conductivity measurements. Our investigations show that incorporation of gold results in enhancement of conductivity in Lithium containing Chitosan films. Also it affects the dielectric characteristics of the films. We conclude through various characterization tools that the enhancement in the conductivity was due to the retardation of crystal growth of lithium salt in the presence of gold nanoparticles. A model is proposed regarding the formation of the new nanocomposite. The conductivity of these biodegradable films is comparable to those of the current inorganic Lithium micro batteries. This new chitosan-Au-Li nanocomposite has potential applications in the field of Lithium micro batteries.

  7. Secondary lithium solid polymer electrolyte cells

    International Nuclear Information System (INIS)

    Fix, K.A.; Sammells, A.F.

    1988-01-01

    A strategy for developing morphologically invariant lithium/solid polymer electrolyte interface is being investigated via the use of lithium intercalated electrodes. Emphasis is being placed upon the rutile material Li/sub x/WO/sub 2/ 0.1 < x < 1.0. An absence of shape change at this interface is expected to result in both long cycle life electrochemical cells and the simultaneous maintenance of small interelectrode spacing so that low IR losses can be maintained. During fabrication of cells investigated here both electrochemical and chemical lithium intercalation of WO/sub 2/ was pursued. In the case of larger WO/sub 2/ electrodes initially prepared for fully discharged state cells, electrochemical intercalation during cell charge was found to require significant time, and the reproducible achievement of complete uniform intercalation across the negative electrode became an issue. Emphasis was consequently placed upon cells fabricated using Li/sub x/WO/sub 2/ electrodes initially chemically intercalated by lithium prior to cell assembly. Previous work has demonstrated direct lithium intercalation of metal dichalcogenides using n-BuLi. Lithium activity in n-BuLi is, however, insufficient to achieve lithium intercalation of WO/sub 2//sup 4/. However, recent work has shown that WO/sub 2/ can be directly lithium intercalated upon immersion in lithium naphthalide. Li/sub x/WO/sub 2/ electrodes prepared in this work were intercalated using lithium naphthalide (0.8M) in 2MeTHF. Lithium intercalation was found to readily occur at room temperature, being initially rapid and slowing as bulk intercalation within the electrode proceeded. For electrodes intercalated in this manner, a relationship was identified between the degree of lithium intercalation and initial open-circuit potential in liquid non-aqueous electrolyte

  8. Molecular motion in polymer electrolytes. An investigation of methods for improving the conductivity of solid polymer electrolytes

    International Nuclear Information System (INIS)

    Webster, Mark Ian

    2002-01-01

    Three methods were explored with a view to enhancing the ionic conductivity of polymer electrolytes; namely the addition of an inert, inorganic filler, the addition of a plasticizer and the incorporation of the electrolyte in the pores of silica matrices. There have been a number of reports, which suggest the addition of nanocrystalline oxides to polymer electrolytes increases the ionic conductivities by about a factor of two. In this thesis studies of the polymer electrolyte NaSCN.P(EO) 8 with added nanocrystalline alumina powder are reported which show no evidence of enhanced conductivity. The addition of a plasticizer to polymer electrolytes will increase the ionic conductivity. A detailed study was made of the polymer electrolytes LiT.P(EO) 10 and LiClO 4 .P(EO) 10 with added ethylene carbonate plasticizer. The conductivities showed an enhancement, however this disappeared on heating under vacuum. The present work suggests that the plasticised system is not thermodynamically stable and will limit the applications of the material. A series of samples were prepared from the polymer electrolyte LiT.P(EO) 8 and a range of porous silicas. The silicas were selected to give a wide range of pore size and included Zeolite Y, ZSM5, mesoporous silica and a range of porous glasses. This gave pore sizes from less than one nm to 50 nm. A variety of experiments, including X-ray diffraction, DSC and NMR, showed that the polymer electrolyte entered to pores of the silica. As a result the polymer was amorphous and the room temperature conductivity was enhanced. The high temperature conductivity was not increased above that for the pure electrolyte. The results suggest that this could be employed in applications, however would require higher conducting electrolytes to be of practical benefit. (author)

  9. The effect of cathodic water on performance of a polymer electrolyte fuel cell

    International Nuclear Information System (INIS)

    Kulikovsky, A.A.

    2004-01-01

    A simple analytical model of water transport in the polymer electrolyte fuel cell is developed. Nonlinear membrane resistance and voltage loss due to incomplete membrane humidification are calculated. Both values depend on parameter r, the ratio of mass transport coefficients of water in the membrane and in the backing layer. Simple equation for cell performance curve, which incorporates the effect of cathodic water is constructed. Depending of the value of r, the cell may operate in one of the two regimes. When r ≥ 1, incomplete membrane humidification simply reduces cell voltage; the limiting current density is determined by oxygen transport in the backing layer (oxygen-limiting regime). If r < 1, limiting current density is determined by membrane drying (water-limiting regime). In that case there exists optimal current density, which provides minimal membrane resistance. It is shown that membrane drying may lead to parasitic 'in-plane' proton current

  10. Report on results of development of fuel cell power generation technology 1998. Research and development on polymer electrolyte fuel cell (technological development of element, research on ion exchange membrane for practicability of high performance cell); 1998 nendo seika hokokusho. Nenryo denchi hatsuden gijutsu kaihatsu, kotai kobunshigata nenryo denchi no kenkyu kaihatsu, yoso kenkyu kaihatsu (koseino denchi jitsuyoka no tame no ion kokan maku ni kansuru kenkyu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This paper explains the results during fiscal 1998 of ion exchange membranes in the development of polymer electrolyte fuel cells. Studies were made on three kinds of standard and two kinds of experimental membranes selected among the Flemion membranes, which are perfluorosulfonic acid membranes made by Asahi Glass Co.,Ltd., and also on the Nafion membranes by Dupon as reference. As the resistance evaluation of the environmental cycle for the membranes, a temperature cycle test was carried out, with the characteristics measured such as moisture content, membrane resistance, mechanical properties, and gas permeability, so that the effects were examined of the temperature cycle on the membranes. Evaluation was also commenced on the water permeability, an important substance-moving characteristic of ion exchange membranes. In the evaluation of the characteristics of membrane-electrode assemblies, the environmental cycle test was performed by joining electrodes to membranes, with the evaluation similarly made as for the membranes alone. On the basis of a correlation between the water permeability and the cell performance, studies were made on the effect of thickness of the membranes on the cell performances. A continuous stability/durability operation of 3,500 hours was verified using Flemion R. As for membrane reinforcement, studies were continued on the cloth and fibril reinforcements as in the previous year.(NEDO)

  11. Solid polymer electrolyte on the basis of polyethylene carbonate-lithium perchlorate system

    International Nuclear Information System (INIS)

    Dukhanin, G.P.; Dumler, S.A.; Sablin, A.N.; Novakov, I.A.

    2009-01-01

    Reaction in the system polyethylene carbonate-lithium perchlorate was investigated by IR spectroscopy, differential thermal and X-ray structural analyses. Specific electric conductivity of the prepared composition has been measured. Solid polymer electrolytes on the basis of polyethylene carbonate have conducting properties as electrolytes on the basis of unmodified polyethylene oxide. Compositions of polyethylene carbonate : LiClO 4 =10 : 1Al 2 O 3 -ZrO 2 possess maximum value of electrical conductivity. Activation energies of the process is calculated for all investigated compositions, and dependence of these values from concentration of lithium perchlorate is established

  12. Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell. [Solid Polymer Electrolyte

    Science.gov (United States)

    Savinell, R. F.; Fritts, S. D.

    1988-01-01

    A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

  13. Conductivity enhancement induced by casting of polymer electrolytes under a magnetic field

    International Nuclear Information System (INIS)

    Kovarsky, R.; Golodnitsky, D.; Peled, E.; Khatun, S.; Stallworth, P.E.; Greenbaum, S.; Greenbaum, A.

    2011-01-01

    Highlights: ► Ordering of polymer electrolytes under applied magnetic field. ► Positive effect of nanosize ferromagnetic filler. ► Structure-ion conductivity interrelationship. - Abstract: We recently presented a procedure for orienting the polyethylene-oxide (PEO) helices in a direction perpendicular to the film plane by casting the polymer electrolytes (PE) under a magnetic field (MF). Here we study the influence of magnetic fields of different strengths and configurations on the structural properties and ionic conductivity of concentrated LiCF 3 SO 3 (LiTf) and LiAsF 6 :P(EO) pristine and composite polymer electrolytes containing γ-Fe 2 O 3 nanoparticles. Some data of LiI:P(EO) system are shown for comparison. We suggest that the effect of type of salt (LiI, LiTf and LiAsF 6 ) on the structure–conductivity relationship of the polymer electrolytes cast under magnetic field is closely connected to the crystallinity of the PEO–LiX system. It was found that the higher the content of the crystalline phase and the size of spherulites in the typically cast salt-polymer system, the stronger the influence of the magnetic field on the conductivity enhancement when the electrolyte is cast and dried under MF. Casting of the PE from a high-dielectric-constant solvent results in disentanglement of the PEO chains, which facilitates even more the perpendicular orientation of helices under applied MF. The enhancement of ionic conductivity was appreciably higher in the PEs cast under strong NdFeB magnets than under SmCo. Both bulk (intrachain) and grain-boundary conductivities increase when a MF is applied, but the improvement in the grain-boundary conductivity – associated with ion-hopping between polymer chains – is more pronounced. For LiAsF 6 :(PEO) 3 at 65 °C, the interchain conductivity increased by a factor of 75, while the intrachain conductivity increased by a factor of 11–14. At room temperature, the SEI resistance of these PEs, cast under NdFeB HMF

  14. Fiscal 1999 phase 2 R and D report of WE-NET (International Clean Energy Network Using Hydrogen Conversion). Task 6. Development of the polymer electrolyte membrane fuel cell supplied with pure hydrogen; 1999 nendo suiso riyo kokusai clean energy system gijutsu (WE-NET) dainiki kenkyu kaihatsu seika hokokusho. Task 6. Junsuiso kyokyu kotai kobunshigata nenryo denchi no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This report summarizes the fiscal 1999 research result on development of element technologies for a pure hydrogen fuel cell power system of nearly 45% in efficiency at terminal, and demonstration test result on the 30kW class polymer electrolyte membrane fuel cell system supplied with pure hydrogen. On cell voltage characteristics in high-utilization operation, study was made on degradation and corrosion caused by short supply of hydrogen by using a single cell. As a result, it was found out that reverse polarization of -3.0V has small effect, however, that of -0.7V causes corrosion and deterioration of cell characteristics in a short time. In operation using actual-size cells for the 30kW class plant, it was effective to wet cells on the air side. On hydrogen high-utilization operation technique, study was made on hydrogen recovery and recycle operation, anode outlet line closed operation, and anode recycle operation. In addition, some studies were made on specifications of auxiliary facilities for fuel cells, safety measures for fuel cells and humidity control of supplied hydrogen gas. (NEDO)

  15. How a gel polymer electrolyte affects performance of lithium/sulfur batteries

    International Nuclear Information System (INIS)

    Zhang, Sheng S.; Tran, Dat T.

    2013-01-01

    Highlights: •Conventional separator is coated with a 50PEO-50SiO 2 (wt.%) composite layer. •Composite coating increases tensile strength and electrolyte wettability. •Coated separator offers an alternative approach for making gel polymer Li/S battery. •Li/S battery takes benefits of gel polymer electrolyte at the expense of capacity. -- Abstract: Gel polymer electrolyte (GPE) and composite gel polymer electrolyte (CGPE) have been widely employed to improve the safety and cycling performance of rechargeable lithium and lithium-ion batteries. In order to determine whether this approach is applicable to lithium/sulfur (Li/S) battery, we examine the effect of CGPE on the cycling and storage performances of Li/S cells by comparing a 50PEO-50SiO 2 (wt.%) composite coated separator (C-separator) with a pristine separator (P-separator). Results show that the composite coating significantly enhances the wettability of liquid electrolyte on the separator and that resulting CGPE can tightly glue the separator and electrode together. In comparison with the P-separator, the C-separator offers Li/S cells similar capacity retention and rate capability; however it greatly affects the specific capacity of sulfur. The analysis on the impedance spectrum of a lithium polysulfide (PS) solution reveal that the reduction of sulfur specific capacity is due to the high viscosity of the CGPE and the strong adsorption of SiO 2 filler to the PS species, which trap PS species in the separator and hence reduce the utilization of sulfur active material. Therefore, the benefits of the GPE and CGPE to the Li/S batteries can be taken only at the expense of sulfur specific capacity

  16. Characterization of plasticized PEO-PAM blend polymer electrolyte system

    Science.gov (United States)

    Dave, Gargi; Kanchan, Dinesh

    2017-05-01

    Present study reports characterization studies of NaCF3SO3 based PEO-PAM Blend Polymer Electrolyte (BPE) system with varying amount of EC+PC as plasticizer prepared by solution cast technique. Structural analysis and surface topography have been performed using FTIR and SEM studies. To understand, thermal properties, DSC studies have been undertaken in the present paper

  17. Electrocatalysis in Water Electrolysis with Solid Polymer Electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Rasten, Egil

    2001-10-01

    Development and optimization of the electrodes in a water electrolysis system using a polymer membrane as electrolyte have been carried out in this work. A cell voltage of 1.59 V (energy consumption of about 3.8 kWh/Nm{sub 3} H{sub 2}) has been obtained at practical operation conditions of the electrolysis cell (10 kA . m2, 90{sup o}C) using a total noble metal loading of less than 2.4 mg.cm{sub 2} and a Nafion -115 membrane. It is further shown that a cell voltage of less than 1.5 V is possible at the same conditions by combination of the best electrodes obtained in this work. The most important limitation of the electrolysis system using polymer membrane as electrolyte has proven to be the electrical conductivity of the catalysts due to the porous backing/current collector system, which increases the length of the current path and decreases the cross section compared to the apparent one. A careful compromise must therefore be obtained between electrical conductivity and active surface area, which can be tailored by preparation and annealing conditions of the metal oxide catalysts. Anode catalysts of different properties have been developed. The mixed oxide of Ir-Ta (85 mole% Ir) was found to exhibit highest voltage efficiency at a current density of 10 kA.m{sub 2} or below, whereas the mixed oxide of Ir and Ru (60-80 mole% Ir) was found to give the highest voltage efficiency for current densities of above 10 kA.m{sub 2}. Pt on carbon particles, was found to be less suitable as cathode catalyst in water electrolysis. The large carbon particles introduced an unnecessary porosity into the catalytic layer, which resulted in a high ohmic drop. Much better voltage efficiency was obtained by using Pt-black as cathode catalyst, which showed a far better electrical conductivity. Ru-oxide as cathode catalyst in water electrolysis systems using a polymer electrolyte was not found to be of particular interest due to insufficient electrochemical activity and too low

  18. Synthesis, Characterization and Battery Performance of A Lithium Poly (4-vinylphenol) Phenolate Borate Composite Membrane

    International Nuclear Information System (INIS)

    Xu, Guodong; Zhang, Yunfeng; Rohan, Rupesh; Cai, Weiwei; Cheng, Hansong

    2014-01-01

    We report synthesis of lithium poly (4-vinylphenol) phenolate borate (LiPVPPB) single-ion conductor comprised of boron atoms with sp 3 electronic configuration covalently bonded to a polystyrene backbone with high thermal and electrochemical stability. The highly delocalized anionic charges surrounding the boron atoms in the polymer give rise to weak association with lithium ions in the polymer matrix, resulting in an ion transference number close to unity and remarkably high ionic conductivity. A composite membrane blended with LiPVPPB and poly(vinylidene-fluoride-co-hexafluoropropene) (PVDF-HFP) was fabricated. The battery of the electrolyte displays excellent cyclability with nearly 100% coulombic efficiency over a wide temperature range. The superior membrane performance suggests that single ion polymer electrolyte materials are highly promising for safe and high power applications of lithium ion batteries

  19. Effect of the alkyl chain length of the ionic liquid anion on polymer electrolytes properties

    International Nuclear Information System (INIS)

    Leones, Rita; Sentanin, Franciani; Nunes, Sílvia Cristina; Esperança, José M.S.S.; Gonçalves, Maria Cristina

    2015-01-01

    New polymer electrolytes (PEs) based on chitosan and three ionic liquid (IL) families ([C 2 mim][C n SO 3 ], [C 2 mim][C n SO 4 ] and [C 2 mim][diC n PO 4 ]) were synthesized by the solvent casting method. The effect of the length of the alkyl chain of the IL anion on the thermal, morphological and electrochemical properties of the PEs was studied. The solid polymer electrolytes SPE membranes were analyzed by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), polarized optical microscopy (POM), atomic force microscopy (AFM), complex impedance spectroscopy (ionic conductivity) and cyclic voltammetry (CV). The obtained results evidenced an influence of the alkyl chain length of the IL anion on the temperature of degradation, birefringence, surface roughness and ionic conductivity of the membranes. The DSC, XRD and CV results showed independency from the length of the IL-anion-alkyl chain. The PEs displayed an predominantly amorphous morphology, a minimum temperature of degradation of 135 °C, a room temperature (T = 25 °C) ionic conductivity of 7.78 × 10 −4 S cm −1 and a wide electrochemical window of ∼ 4.0 V.

  20. A mathematical model of the solid-polymer-electrolyte fuel cell

    International Nuclear Information System (INIS)

    Bernardi, D.M.; Verbrugge, M.W.

    1992-01-01

    This paper presents a mathematical model of the solid-polymer-electrolyte fuel cell and apply it to (i) investigate factors that limit cell performance and (ii) elucidate the mechanism of species transport in the complex network of gas, liquid, and solid phases of the cell. Calculations of cell polarization behavior compare favorably with existing experimental data. For most practical electrode thicknesses, model results indicate that the volume fraction of the cathode available for gas transport must exceed 20% in order to avoid unacceptably low cell-limiting current densities. It is shown that membrane dehydration can also pose limitations on operating current density; circumvention of this problem by appropriate membrane and electrode design and efficient water-management schemes is discussed. The authors' model results indicate that for a broad range of practical current densities there are no external water requirements because the water produced at the cathode is enough to satisfy the water requirement of the membrane

  1. Effect of the hydrophilic and hydrophobic characteristics of the gas diffusion medium on polymer electrolyte fuel cell performance under non-humidification condition

    International Nuclear Information System (INIS)

    Park, Heesung

    2014-01-01

    Highlights: • GDM played significant role in the PEFC performance under dry condition. • Hydrophobicity of GDM affect the water condensation at the surface. • Optimum water saturation in the porous layer was between 0.1 and 0.3. - Abstract: Water is a significant component of polymer electrolyte fuel cells, affecting the proton conductivity in the membrane electrolyte. Therefore, polymer electrolyte fuel cells are generally operated with a humidifier to maintain a high relative humidity of the supplied gases; however, the humidifier contributes additional weight and cost. Although many studies have attempted to develop polymer electrolyte fuel cells without a humidifier, the studies have been mainly focused on the self-humidified membrane electrolyte and catalyst layer. In this paper, the author investigates the effect of polytetrafluoroethylene coated gas diffusion medium on the water content in the membrane electrolyte. The water condensation on the surfaces of the gas diffusion medium is visualised when the polymer electrolyte fuel cell is operated under non-humidification conditions. Numerical simulation suggests that the optimum water saturation is between 0.1 and 0.3 at the gas diffusion medium to hydrate the membrane electrolyte sufficiently without significantly blocking the diffused species under non-humidification conditions

  2. Modeling of ionic transport in solid polymer electrolytes

    International Nuclear Information System (INIS)

    Cheang, P L; Teo, L L; Lim, T L

    2010-01-01

    A Monte Carlo model describing the ionic trans port in solid polyme relectrolyte is developed. Single cation simulation is carried out using hopping rate to study the transport mechanism of a thermally activated ion in solid polymer electrolyte. In our model, the ion is able to hop along a polymer chain and to jump between different chains, surmounting energy barriers that consist of polymer's activation energy and the externally applied electric field. The model is able to trace the motion of ion across polymer electrolyte. The mean hopping distance is calculated based on the available open bond in the next nearest side. Random numbers are used to determine the hopping distances, free flight times, final energy and direction of the cation after successful hop. Drift velocity and energy of cation are simulated in our work. The model is expected to be able to simulate the lithium-polymer battery in future.

  3. Structure-conductivity studies in polymer electrolytes containing multivalent cations

    International Nuclear Information System (INIS)

    Aziz, M.

    1996-05-01

    Understanding the structure - conductivity relationship is of paramount importance for the development of polymer electrolytes. The present studies present the techniques found useful in the elucidation of structure - conductivity relationship in PEO n :ZnBr 2 (n = 8, 1000, 2000, 3000, 4000 and 5000) and PEO n :FeBr x (n= 8, 20 and 50; x = 2 and 3). Local structural studies have been undertaken using X-ray absorption fine structures (XAFS) which includes extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES). EXAFS provides interatomic distance and coordination numbers of the nearest neighbours and results from the EXAFS studies showed that high conductivity is associated with stretched M - O interatomic distance. In the studies on ultra dilute Zn samples it was found that the cation is highly solvated by the heteroatom forming a tightly bound environment which inhibits local segmental motion thus impeding ion migration. XANES studies on the PEO and modified PEO complexes of NiBr 2 revealed the sensitivity of XANES to the structural differences. XANES on Zn and Fe samples also revealed the sensitivity to changes in interatomic distances reflected in shifts of the white line. The complementary nature of EXAFS and XANES was reflected in the studies conducted. Morphological studies were undertaken employing differential scanning calorimetry (DSC), variable temperature polarising microscopy (VTPM) and atomic force microscopy (AFM). DSC evidences helped to explain the texture of the iron samples during the drying process, and showed transitions between low melting, PEO and high melting spherulites, and VTPM is able to visualise the spherulites present in the samples. AFM has successfully imaged the as cast PEO 8 :FeBr 2 sample and the surface effect causing extra resistance in the impedance spectra could be seen. Conductivity studies were carried out using a.c. impedance spectra. Fe(ll) samples exhibit the typical semicircle

  4. Advanced Proton Conducting Polymer Electrolytes for Electrochemical Capacitors

    Science.gov (United States)

    Gao, Han

    Research on solid electrochemical energy storage devices aims to provide high performance, low cost, and safe operation solutions for emerging applications from flexible consumer electronics to microelectronics. Polymer electrolytes, minimizing device sealing and liquid electrolyte leakage, are key enablers for these next-generation technologies. In this thesis, a novel proton-conducing polymer electrolyte system has been developed using heteropolyacids (HPAs) and polyvinyl alcohol for electrochemical capacitors. A thorough understanding of proton conduction mechanisms of HPAs together with the interactions among HPAs, additives, and polymer framework has been developed. Structure and chemical bonding of the electrolytes have been studied extensively to identify and elucidate key attributes affecting the electrolyte properties. Numerical models describing the proton conduction mechanism have been applied to differentiate those attributes. The performance optimization of the polymer electrolytes through additives, polymer structural modifications, and synthesis of alternative HPAs has achieved several important milestones, including: (a) high proton mobility and proton density; (b) good ion accessibility at electrode/electrolyte interface; (c) wide electrochemical stability window; and (d) good environmental stability. Specifically, high proton mobility has been addressed by cross-linking the polymer framework to improve the water storage capability at normal-to-high humidity conditions (e.g. 50-80% RH) as well as by incorporating nano-fillers to enhance the water retention at normal humidity levels (e.g. 30-60% RH). High proton density has been reached by utilizing additional proton donors (i.e. acidic plasticizers) and by developing different HPAs. Good ion accessibility has been achieved through addition of plasticizers. Electrochemical stability window of the electrolyte system has also been investigated and expanded by utilizing HPAs with different heteroatoms

  5. 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

  6. Polymer-electrolyte-gated nanowire synaptic transistors for neuromorphic applications

    Science.gov (United States)

    Zou, Can; Sun, Jia; Gou, Guangyang; Kong, Ling-An; Qian, Chuan; Dai, Guozhang; Yang, Junliang; Guo, Guang-hua

    2017-09-01

    Polymer-electrolytes are formed by dissolving a salt in polymer instead of water, the conducting mechanism involves the segmental motion-assisted diffusion of ion in the polymer matrix. Here, we report on the fabrication of tin oxide (SnO2) nanowire synaptic transistors using polymer-electrolyte gating. A thin layer of poly(ethylene oxide) and lithium perchlorate (PEO/LiClO4) was deposited on top of the devices, which was used to boost device performances. A voltage spike applied on the in-plane gate attracts ions toward the polymer-electrolyte/SnO2 nanowire interface and the ions are gradually returned after the pulse is removed, which can induce a dynamic excitatory postsynaptic current in the nanowire channel. The SnO2 synaptic transistors exhibit the behavior of short-term plasticity like the paired-pulse facilitation and self-adaptation, which is related to the electric double-effect regulation. In addition, the synaptic logic functions and the logical function transformation are also discussed. Such single SnO2 nanowire-based synaptic transistors are of great importance for future neuromorphic devices.

  7. 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.

  8. Studies on the structure and transport properties of hexanoyl chitosan-based polymer electrolytes

    International Nuclear Information System (INIS)

    Winie, Tan; Ramesh, S.; Arof, A.K.

    2009-01-01

    Polymer electrolytes composed of hexanoyl chitosan as the host polymer, lithium trifluoromethanesulfonate (LiCF 3 SO 3 ) as the salt, diethyl carbonate (DEC)/ethylene carbonate (EC) as the plasticizers were prepared and characterized by X-ray diffraction and impedance spectroscopy. The X-ray diffraction results reveal the variation in conductivity from structural aspect. This is reflected in terms of amorphous content. Sample with higher amorphous content exhibits higher conductivity. In order to further understand the source of the conductivity variation with varying plasticizers compositions as well as temperatures, the ionic charge carrier concentration and their mobility in polymer electrolyte were determined. The Rice and Roth model was proposed to be used to estimate the ionic charge carrier concentration, n. Knowing n and combining the result with dc conductivity, the mobility of the ionic charge carrier can be calculated. It is found that the conductivity change with DEC/EC composition is due mainly to the change in ionic charge carrier concentration while the conductivity change with temperature is due primarily to the change in mobility.

  9. Studies on the structure and transport properties of hexanoyl chitosan-based polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Winie, Tan, E-mail: tanwinie@salam.uitm.edu.m [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia); Ramesh, S. [Faculty of Engineering and Science, University Tunku Abdul Rahman, 53300 Kuala Lumpur (Malaysia); Arof, A.K. [Physics Department, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2009-11-15

    Polymer electrolytes composed of hexanoyl chitosan as the host polymer, lithium trifluoromethanesulfonate (LiCF{sub 3}SO{sub 3}) as the salt, diethyl carbonate (DEC)/ethylene carbonate (EC) as the plasticizers were prepared and characterized by X-ray diffraction and impedance spectroscopy. The X-ray diffraction results reveal the variation in conductivity from structural aspect. This is reflected in terms of amorphous content. Sample with higher amorphous content exhibits higher conductivity. In order to further understand the source of the conductivity variation with varying plasticizers compositions as well as temperatures, the ionic charge carrier concentration and their mobility in polymer electrolyte were determined. The Rice and Roth model was proposed to be used to estimate the ionic charge carrier concentration, n. Knowing n and combining the result with dc conductivity, the mobility of the ionic charge carrier can be calculated. It is found that the conductivity change with DEC/EC composition is due mainly to the change in ionic charge carrier concentration while the conductivity change with temperature is due primarily to the change in mobility.

  10. Composite polymer membranes for proton exchange membrane fuel cells operating at elevated temperatures and reduced humidities

    Science.gov (United States)

    Zhang, Tao

    Proton Exchange Membrane Fuel Cells (PEMFCs) are the leading candidate in the fuel cell technology due to the high power density, solid electrolyte, and low operational temperature. However, PEMFCs operating in the normal temperature range (60-80°C) face problems including poor carbon monoxide tolerance and heat rejection. The poisoning effect can be significantly relieved by operating the fuel cell at elevated temperature, which also improves the heat rejection and electrochemical kinetics. Low relative humidity (RH) operation is also desirable to simplify the reactant humidification system. However, at elevated temperatures, reduced RH PEMFC performance is seriously impaired due to irreversible water loss from presently employed state-of-the-art polymer membrane, Nafion. This thesis focuses on developing polymer electrolyte membranes with high water retention ability for operation in elevated temperature (110-150°C), reduced humidity (˜50%RH) PEMFCs. One approach is to alter Nafion by adding inorganic particles such as TiO2, SiO2, Zr(HPO 4)2, etc. While the presence of these materials in Nafion has proven beneficial, a reduction or no improvement in the PEMFC performance of Nafion/TiO2 and Nafion/Zr(HPO4)2 membranes is observed with reduced particle sizes or increased particle loadings in Nafion. It is concluded that the PEMFC performance enhancement associated with addition of these inorganic particles was not due to the particle hydrophilicity. Rather, the particle, partially located in the hydrophobic region of the membrane, benefits the cell performance by altering the membrane structure. Water transport properties of some Nafion composite membranes were investigated by NMR methods including pulsed field gradient spin echo diffusion, spin-lattice relaxation, and spectral measurements. Compared to unmodified Nafion, composite membranes materials exhibit longer longitudinal relaxation time constant T1. In addition to the Nafion material, sulfonated styrene

  11. Composite membrane with integral rim

    Science.gov (United States)

    Routkevitch, Dmitri; Polyakov, Oleg G

    2015-01-27

    Composite membranes that are adapted for separation, purification, filtration, analysis, reaction and sensing. The composite membranes can include a porous support structure having elongate pore channels extending through the support structure. The composite membrane also includes an active layer comprising an active layer material, where the active layer material is completely disposed within the pore channels between the surfaces of the support structure. The active layer is intimately integrated within the support structure, thus enabling great robustness, reliability, resistance to mechanical stress and thermal cycling, and high selectivity. Methods for the fabrication of composite membranes are also provided.

  12. Enzymatically-Catalyzed Polymerization (ECP)- Derived Polymer Electrolyte for Rechargeable Li-Ion Batteries

    National Research Council Canada - National Science Library

    Chua, David

    1998-01-01

    Report developed under SBIR contract covers the syntheses and electrochemical characterizations of novel polymer electrolytes derived from compounds synthesized via enzyme-catalyzed polymerization(ECP) techniques...

  13. Novel composite Zr/PBI-O-PhT membranes for HT-PEFC applications.

    Science.gov (United States)

    Kondratenko, Mikhail S; Ponomarev, Igor I; Gallyamov, Marat O; Razorenov, Dmitry Yu; Volkova, Yulia A; Kharitonova, Elena P; Khokhlov, Alexei R

    2013-01-01

    Novel composite membranes for high temperature polymer-electrolyte fuel cells (HT-PEFC) based on a poly[oxy-3,3-bis(4'-benzimidazol-2″-ylphenyl)phtalide-5″(6″)-diyl] (PBI-O-PhT) polymer with small amounts of added Zr were prepared. It was shown in a model reaction between zirconium acetylacetonate (Zr(acac)4) and benzimidazole (BI) that Zr-atoms are capable to form chemical bonds with BI. Thus, Zr may be used as a crosslinking agent for PBI membranes. The obtained Zr/PBI-O-PhT composite membranes were examined by means of SAXS, thermomechanical analysis (TMA), and were tested in operating fuel cells by means of stationary voltammetry and impedance spectroscopy. The new membranes showed excellent stability in a 2000-hour fuel cell (FC) durability test. The modification of the PBI-O-PhT films with Zr facilitated an increase of the phosphoric acid (PA) uptake by the membranes, which resulted in an up to 2.5 times increased proton conductivity. The existence of an optimal amount of Zr content in the modified PBI-O-PhT film was shown. Larger amounts of Zr lead to a lower PA doping level and a reduced conductivity due to an excessively high degree of crosslinking.

  14. Dynamics and relaxation of charge carriers in poly(methylmethacrylate)-lithium salt based polymer electrolytes plasticized with ethylene carbonate

    Science.gov (United States)

    Pal, P.; Ghosh, A.

    2016-07-01

    In this paper, we have studied the dynamics and relaxation of charge carriers in poly(methylmethacrylate)-lithium salt based polymer electrolytes plasticized with ethylene carbonate. Structural and thermal properties have been examined using X-ray diffraction and differential scanning calorimetry, respectively. We have analyzed the complex conductivity spectra by using power law model coupled with the contribution of electrode polarization at low frequencies and high temperatures. The temperature dependence of the ionic conductivity and crossover frequency exhibits Vogel-Tammann-Fulcher type behavior indicating a strong coupling between the ionic and the polymer chain segmental motions. The scaling of the ac conductivity indicates that relaxation dynamics of charge carriers follows a common mechanism for all temperatures and ethylene carbonate concentrations. The analysis of the ac conductivity also shows the existence of a nearly constant loss in these polymer electrolytes at low temperatures and high frequencies. The fraction of free anions and ion pairs in polymer electrolyte have been obtained from the analysis of Fourier transform infrared spectra. It is observed that these quantities influence the behavior of the composition dependence of the ionic conductivity.

  15. Ionic conductivity and dielectric permittivity of PEO-LiClO4 solid polymer electrolyte plasticized with propylene carbonate

    Directory of Open Access Journals (Sweden)

    S. Das

    2015-02-01

    Full Text Available We have studied ionic conductivity and dielectric permittivity of PEO-LiClO4 solid polymer electrolyte plasticized with propylene carbonate. Differential scanning calorimetry and X-ray diffraction studies confirm minimum volume fraction of crystalline phase for the polymer electrolyte with 40 wt. % propylene carbonate. The ionic conductivity exhibits a maximum for the same composition. The temperature dependence of the ionic conductivity has been well interpreted using Vogel-Tamman-Fulcher equation. Ion-ion interactions in the polymer electrolytes have been studied using Raman spectra and the concentrations of free ions, ion-pairs and ion-aggregates have been determined. The ionic conductivity increases due to the increase of free ions with the increase of propylene carbonate content. But for higher content of propylene carbonate, the ionic conductivity decreases due to the increase of concentrations of ion-pairs and ion-aggregates. To get further insights into the ion dynamics, the experimental data for the complex dielectric permittivity have been studied using Havriliak–Negami function. The variation of relaxation time with temperature obtained from this formalism follows Vogel-Tamman-Fulcher equation similar to the ionic conductivity.

  16. Ionic conductivity and dielectric permittivity of PEO-LiClO{sub 4} solid polymer electrolyte plasticized with propylene carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Das, S.; Ghosh, A., E-mail: sspag@iacs.res.in [Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

    2015-02-15

    We have studied ionic conductivity and dielectric permittivity of PEO-LiClO{sub 4} solid polymer electrolyte plasticized with propylene carbonate. Differential scanning calorimetry and X-ray diffraction studies confirm minimum volume fraction of crystalline phase for the polymer electrolyte with 40 wt. % propylene carbonate. The ionic conductivity exhibits a maximum for the same composition. The temperature dependence of the ionic conductivity has been well interpreted using Vogel-Tamman-Fulcher equation. Ion-ion interactions in the polymer electrolytes have been studied using Raman spectra and the concentrations of free ions, ion-pairs and ion-aggregates have been determined. The ionic conductivity increases due to the increase of free ions with the increase of propylene carbonate content. But for higher content of propylene carbonate, the ionic conductivity decreases due to the increase of concentrations of ion-pairs and ion-aggregates. To get further insights into the ion dynamics, the experimental data for the complex dielectric permittivity have been studied using Havriliak–Negami function. The variation of relaxation time with temperature obtained from this formalism follows Vogel-Tamman-Fulcher equation similar to the ionic conductivity.

  17. Dynamics and relaxation of charge carriers in poly(methylmethacrylate)-lithium salt based polymer electrolytes plasticized with ethylene carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Pal, P.; Ghosh, A., E-mail: sspag@iacs.res.in [Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

    2016-07-28

    In this paper, we have studied the dynamics and relaxation of charge carriers in poly(methylmethacrylate)-lithium salt based polymer electrolytes plasticized with ethylene carbonate. Structural and thermal properties have been examined using X-ray diffraction and differential scanning calorimetry, respectively. We have analyzed the complex conductivity spectra by using power law model coupled with the contribution of electrode polarization at low frequencies and high temperatures. The temperature dependence of the ionic conductivity and crossover frequency exhibits Vogel-Tammann-Fulcher type behavior indicating a strong coupling between the ionic and the polymer chain segmental motions. The scaling of the ac conductivity indicates that relaxation dynamics of charge carriers follows a common mechanism for all temperatures and ethylene carbonate concentrations. The analysis of the ac conductivity also shows the existence of a nearly constant loss in these polymer electrolytes at low temperatures and high frequencies. The fraction of free anions and ion pairs in polymer electrolyte have been obtained from the analysis of Fourier transform infrared spectra. It is observed that these quantities influence the behavior of the composition dependence of the ionic conductivity.

  18. Multilayered sulphonated polysulfone/silica composite membranes for fuel cell applications

    International Nuclear Information System (INIS)

    Padmavathi, Rajangam; Karthikumar, Rajendhiran; Sangeetha, Dharmalingam

    2012-01-01

    Highlights: ► Multilayered membranes were fabricated with SPSu. ► Aminated polysulfone and silica were used as the layers in order to prevent the crossover of methanol. ► The methanol permeability and selectivity ratio proved a strong influence on DMFC application. ► The suitability of the multilayered membranes was studied in the lab made set-ups of PEMFC and DMFC. - Abstract: Polymer electrolyte membranes used in proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC) suffer from low dimensional stability. Hence multilayered membranes using sulfonated polysulfone (SPSu) and silica (SiO 2 ) were fabricated to alter such properties. The introduction of an SiO 2 layer between two layers of SPSu to form the multilayered composite membrane enhanced its dimensional stability, but slightly lowered its proton conductivity when compared to the conventional SPSu/SiO 2 composite membrane. Additionally, higher water absorption, lower methanol permeability and higher flame retardancy were also observed in this newly fabricated multilayered membrane. The performance evaluation of the 2 wt% SiO 2 loaded multilayered membrane in DMFC showed a maximum power density of 86.25 mW cm −2 , which was higher than that obtained for Nafion 117 membrane (52.8 mW cm −2 ) in the same single cell test assembly. Hence, due to the enhanced dimensional stability, reduced methanol permeability and higher maximum power density, the SPSu/SiO 2 /SPSu multilayered membrane can be a viable and a promising candidate for use as an electrolyte membrane in DMFC applications, when compared to Nafion.

  19. Study of microporous PVA/PVC composite polymer membrane and it application to MnO2 capacitors

    International Nuclear Information System (INIS)

    Yang, C.-C.; Wu, G.M.

    2009-01-01

    A microporous poly(vinyl alcohol)/poly(vinyl chloride) (PVA/PVC) composite polymer membrane was successfully synthesized by a solution casting method and a preferential dissolution method. The characteristic properties of PVA/PVC composite polymer membranes were systematically studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), micro-Raman spectroscopy and AC impedance spectroscopy. The PVA/PVC composite polymer membrane shows excellent thermal property, dimensional stability, and the ionic conductivity; it is due to the addition of secondary PVC polymer fillers. The MnO 2 capacitors with the PVA/PVC composite polymer membrane with 1 M Na 2 SO 4 was assembled and examined. It was found that the MnO 2 capacitor based on a microporous PVA/5 wt.%PVC composite polymer electrolyte membrane exhibited the maximum specific capacitance of 238 F g -1 and the current efficiency of 99% at 25 mV s -1 after 1000 cycle test. The result demonstrates that the novel microporous PVA/PVC composite polymer membrane is a potential candidate for use on the capacitors

  20. Synthesis and characterization of partially fluorinated poly(acryl) ionomers for polymer electrolyte membrane fuel cells and ESR-spectroscopic investigation of the radically induced degradation of model compounds; Synthese und Charakterisierung teilfluorierter Poly(acryl)-Ionomere als Polymerelektrolytmembranen fuer Brennstoffzellen und ESR-spektroskopische Untersuchung der radikalinduzierten Degradation von Modellverbindungen

    Energy Technology Data Exchange (ETDEWEB)

    Schoenberger, Frank

    2008-07-09

    In the first part of this work different strategies for the design of sulfonated partially fluorinated poly(aryl)s are developed and synthetically realized. The applied concept is that partially fluorinated poly(aryl)s are distinguished from the nonfluorinated ones by an enhanced acidity. Moreover they possess higher bond dissociation energies of both the C-F bonds and any adjacent C-H bonds which should be associated with a gain in radical stability and thus in chemical and thermal stability. In order to investigate the influence of the chemical structure of (partially fluorinated) monomeric building blocks, homo-polymers with different structural units (with aromatic C-F bonds, C(CF3)2-bridged and/or CF3-substituted phenylene rings) are synthesized by polycondensation and structurally characterized (elemental analysis, NMR spectroscopy, gel permeation chromatography). Established organic reactions, such as the Balz-Schiemann reaction, Suzuki reaction and Ullmann's biaryl synthesis, are applied for the synthesis of the specific monomers. After sulfonation of the homo-polymers (ionically crosslinked) membranes are prepared and characterized in terms of suitability as polymer electrolyte membrane in fuel cells (ion-exchange capacity, proton conductivity, thermal and chemical stability, water uptake, dimensional change). Both the chemical nature of the monomers and their constitution in the ionomer are important for the properties of the resulting membranes. Therefore microphase-separated multiblock-co-ionomers based on hydrophilic (sulfonated) and hydrophobic (partially fluorinated) telechelic macromonomers are prepared and characterized. Both the influence of the block length and the chemical nature of the used monomers on the membrane properties are comparatively investigated. On the basis of the findings gained in this part of the work, the advantages and disadvantages of partially fluorinated ionomer membranes are analyzed and discussed. The second part of

  1. Polymer electrolyte fuel cells physical principles of materials and operation

    CERN Document Server

    Eikerling, Michael

    2014-01-01

    The book provides a systematic and profound account of scientific challenges in fuel cell research. The introductory chapters bring readers up to date on the urgency and implications of the global energy challenge, the prospects of electrochemical energy conversion technologies, and the thermodynamic and electrochemical principles underlying the operation of polymer electrolyte fuel cells. The book then presents the scientific challenges in fuel cell research as a systematic account of distinct components, length scales, physicochemical processes, and scientific disciplines. The main part of t

  2. Polymer electrolyte fuel cells: flow field for efficient air operation

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, F N; Tsukada, A; Haas, O; Scherer, G G [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    A new flow field was designed for a polymer electrolyte fuel cell stack with an active area of 200 cm{sup 2} for operation at low air stoichiometry and low air over pressure. Optimum of gas flow and channel dimensions were calculated based on the required pressure drop in the fluid. Single cells and a bi-cell stack with the new flow field show an improved current/voltage characteristic when operated at low air stoichiometries as compared to that of the previous non optimized design. (author) 4 figs., 3 refs.

  3. Local impact of humidification on degradation in polymer electrolyte fuel cells

    Science.gov (United States)

    Sanchez, Daniel G.; Ruiu, Tiziana; Biswas, Indro; Schulze, Mathias; Helmly, Stefan; Friedrich, K. Andreas

    2017-06-01

    The water level in a polymer electrolyte membrane fuel cell (PEMFC) affects the durability as is seen from the degradation processes during operation a PEMFC with fully- and nonhumidified gas streams as analyzed using an in-situ segmented cell for local current density measurements during a 300 h test operating under constant conditions and using ex situ SEM/EDX and XPS post-test analysis of specific regions. The impact of the RH on spatial distribution of the degradation process results from different water distribution giving different chemical environments. Under nonhumidified gas streams, the cathode inlet region exhibits increased degradation, whereas with fully humidified gases the bottom of the cell had the higher performance losses. The degradation and the degree of reversibility produced by Pt dissolution, PTFE defluorination, and contaminants such as silicon (Si) and nickel (Ni) were locally evaluated.

  4. Hydrogen production by steam reforming methanol for polymer electrolyte fuel cells

    International Nuclear Information System (INIS)

    Amphlett, J.C.; Creber, K.A.M.; Davis, J.M.; Mann, R.F.; Peppley, B.A.; Stokes, D.M.

    1993-01-01

    Catalytic steam reforming of methanol has been studied as a means of generating hydrogen for a polymer electrolyte membrane fuel cell. A semi-empirical model of the kinetics of the catalytic steam reforming of methanol over Cu O/Zn O/Al 2 O 3 catalyst has been developed. This model is able to predict the performance of the reformer with respect to the various parameters important in developing an integrated reformer-polymer fuel cell system. A set of sample calculations of reformer temperature and CO production are given. The impact of the performance of the reformer catalyst on the design of the overall fuel cell power system is discussed. The selectivity of the catalyst to minimize CO content in the fuel gas is shown to be more critical than was previously believed. 4 figs., 4 tabs., 11 refs

  5. Preparation of a microporous polymer electrolyte based on poly(vinyl chloride)/poly(acrylonitrile-butyl acrylate) blend for Li-ion batteries

    International Nuclear Information System (INIS)

    Tian, Zheng; Pu, Weihua; He, Xiangming; Wan, Chunrong; Jiang, Changyin

    2007-01-01

    Poly(acrylonitrile-co-butyl acrylate) (P(AN-co-BuA))/poly(vinyl chloride) (PVC) blend-based gel polymer electrolyte (BGPE) was prepared for lithium-ion batteries. The P(AN-co-BuA)/PVC BGPE consists of an electrolyte-rich phase, which is mainly composed of P(AN-co-BuA) and liquid electrolyte, acting as a conducting channel and a PVC-rich phase that provides mechanical strength. The dual phase was just simply developed by the difference of miscibility properties in solvent, PC, between P(AN-co-BuA) and PVC. The mechanical strength of this new blend electrolyte was found to be much higher, with a fracture stress as high as 29 MPa in dry membrane and 21 MPa in gel state, than that of a previously reported P(AN-co-BuA)-based gel polymer electrolyte. The blended gel polymer electrolyte showed ionic conductivity of higher than 1.5 x 10 -3 S cm -1 and electrochemical stability up to at least 4.8 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for lithium-ion batteries

  6. Preparation of a microporous polymer electrolyte based on poly(vinyl chloride)/poly(acrylonitrile-butyl acrylate) blend for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Zheng; Pu, Weihua; He, Xiangming; Wan, Chunrong; Jiang, Changyin [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)

    2007-02-15

    Poly(acrylonitrile-co-butyl acrylate) (P(AN-co-BuA))/poly(vinyl chloride) (PVC) blend-based gel polymer electrolyte (BGPE) was prepared for lithium-ion batteries. The P(AN-co-BuA)/PVC BGPE consists of an electrolyte-rich phase, which is mainly composed of P(AN-co-BuA) and liquid electrolyte, acting as a conducting channel and a PVC-rich phase that provides mechanical strength. The dual phase was just simply developed by the difference of miscibility properties in solvent, PC, between P(AN-co-BuA) and PVC. The mechanical strength of this new blend electrolyte was found to be much higher, with a fracture stress as high as 29 MPa in dry membrane and 21 MPa in gel state, than that of a previously reported P(AN-co-BuA)-based gel polymer electrolyte. The blended gel polymer electrolyte showed ionic conductivity of higher than 1.5 x 10{sup -3} S cm{sup -1} and electrochemical stability up to at least 4.8 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for lithium-ion batteries. (author)

  7. Efficiency of Polymer Electrolyte Membrane Fuel Cell Stack

    Directory of Open Access Journals (Sweden)

    Hans Bosma

    2011-08-01

    Full Text Available This paper applies a feedforward control of optimal oxygen excess ratio that maximize net power (improve efficiency of a NedStack P8.0-64 PEM fuel cell stack (FCS system. Net powers profile as a function of oxygen excess ratio for some points of operation are analyzed by using FCS model. The relationships between stack current and the corresponding control input voltage that gives an optimal oxygen excess ratio are used to design a feedforward control scheme. The results of this scheme are compared to the results of a feedforward control using a constant oxygen excess ratio. Simulation results show that optimal oxygen excess ratio improves fuel cell performance compared to the results of constant oxygen excess ratio. The same procedures are performed experimentally for the FCS system. The behaviour of the net power of the fuel cell stack with respect to the variation of oxygen excess ratio is analyzed to obtain optimal values. Data of stack current and the corresponding voltage input to the compressor that gives optimal values of oxygen excess ratio are used to develop a feedforward control. Feedforward control based on constant and optimal oxygen excess ratio control, are implemented in the NedStack P8.0-64 PEM fuel cell stack system by using LabVIEW. Implementation results shows that optimal oxygen excess ratio control improves the fuel cell performance compared to the constant oxygen excess ratio control.

  8. Nafion and modified-Nafion membranes for polymer electrolyte fuel ...

    Indian Academy of Sciences (India)

    Administrator

    geothermal energy, wind energy and fusion power tech- nology have attracted .... the power plants for Gemini space missions in the early. 1960s. But the cells .... samples and measuring water uptake as a function of time in the temperature ...

  9. Economics of Direct Hydrogen Polymer Electrolyte Membrane Fuel Cell Systems

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevan, Kathyayani

    2011-10-04

    Battelle's Economic Analysis of PEM Fuel Cell Systems project was initiated in 2003 to evaluate the technology and markets that are near-term and potentially could support the transition to fuel cells in automotive markets. The objective of Battelle?s project was to assist the DOE in developing fuel cell systems for pre-automotive applications by analyzing the technical, economic, and market drivers of direct hydrogen PEM fuel cell adoption. The project was executed over a 6-year period (2003 to 2010) and a variety of analyses were completed in that period. The analyses presented in the final report include: Commercialization scenarios for stationary generation through 2015 (2004); Stakeholder feedback on technology status and performance status of fuel cell systems (2004); Development of manufacturing costs of stationary PEM fuel cell systems for backup power markets (2004); Identification of near-term and mid-term markets for PEM fuel cells (2006); Development of the value proposition and market opportunity of PEM fuel cells in near-term markets by assessing the lifecycle cost of PEM fuel cells as compared to conventional alternatives used in the marketplace and modeling market penetration (2006); Development of the value proposition of PEM fuel cells in government markets (2007); Development of the value proposition and opportunity for large fuel cell system application at data centers and wastewater treatment plants (2008); Update of the manufacturing costs of PEM fuel cells for backup power applications (2009).

  10. Direct dimethyl ether high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Vassiliev, Anton; Jensen, Jens Oluf; Li, Qingfeng

    and suffers from low DME solubility in water. When the DME - water mixture is fed as vapour miscibility is no longer a problem. The increased temperature is more beneficial for the kinetics of the direct oxidation of DME than of methanol. The Open Circuit Voltage (OCV) with DME operation was 50 to 100 m......A high temperature polybenzimidazole (PBI) polymer fuel cell was fed with dimethyl ether (DME) and water vapour mixture on the anode at ambient pressure with air as oxidant. A peak power density of 79 mW/cm2 was achieved at 200°C. A conventional polymer based direct DME fuel cell is liquid fed......V higher than that of methanol, indicating less fuel crossover....

  11. Non-precious electrocatalysts for polymer electrolyte fuel cell cathode

    Energy Technology Data Exchange (ETDEWEB)

    Wu, G.; Chung, H.T.; Zelenay, P. [Los Alamos National Laboratory, Los Alamos, NM (United States). Materials Physics and Applications

    2009-07-01

    This study investigated the feasibility of reducing the high cost of polymer electrolyte fuel cell stacks by using non-precious catalysts for the oxygen reduction reaction (ORR). Most research interest has focused on ORR catalysts based on heat-treated precursors of transition metals, nitrogen and carbon. While initial ORR activity of such catalysts has improved in recent years, it is not sufficient for automotive use. The long-term stability of these catalysts is also insufficient. The activity and durability of the catalysts must be improved significantly in order to overcome these limitations. In addition, innovative electrode structures must be developed to allow for operation with thick catalyst layers. The ORR reaction mechanism must also be well understood in terms of the active reaction site. This presentation summarized non-precious ORR catalysis research at Los Alamos, with particular focus on catalysts obtained by heat treatment of polymers (such as polyaniline) on high-surface-area carbon in the presence of transition metals, cobalt and iron. These heat-treated catalysts achieve respectable ORR activity and improved stability in both aqueous and polymer electrolytes. Electrochemical and non-electrochemical techniques such as XPS, XANES and XAFS were used to examine the source of ORR activity of these heat-treated catalysts.

  12. Thermally responsive polymer electrolytes for inherently safe electrochemical energy storage

    Science.gov (United States)

    Kelly, Jesse C.

    Electrochemical double layer capacitors (EDLCs), supercapacitors and Li-ion batteries have emerged as premier candidates to meet the rising demands in energy storage; however, such systems are limited by thermal hazards, thermal runaway, fires and explosions, all of which become increasingly more dangerous in large-format devices. To prevent such scenarios, thermally-responsive polymer electrolytes (RPEs) that alter properties in electrochemical energy storage devices were designed and tested. These RPEs will be used to limit or halt device operation when temperatures increase beyond a predetermined threshold, therefore limiting further heating. The development of these responsive systems will offer an inherent safety mechanism in electrochemical energy storage devices, while preserving the performance, lifetimes, and versatility that large-format systems require. Initial work focused on the development of a model system that demonstrated the concept of RPEs in an electrochemical device. Aqueous electrolyte solutions of polymers exhibiting properties that change in response to temperature were developed for applications in EDLCs and supercapacitors. These "smart materials" provide a means to control electrochemical systems where polymer phase separation at high temperatures affects electrolyte properties and inhibits device performance. Aqueous RPEs were synthesized using N-isopropylacrylamide, which governs the thermal properties, and fractions of acrylic acid or vinyl sulfonic acids, which provide ions to the solution. The molecular properties of these aqueous RPEs, specifically the ionic composition, were shown to influence the temperature-dependent electrolyte properties and the extent to which these electrolytes control the energy storage characteristics of a supercapacitor device. Materials with high ionic content provided the highest room temperature conductivity and electrochemical activity; however, RPEs with low ionic content provided the highest "on

  13. 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

  14. 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...

  15. Layered plasma polymer composite membranes

    Science.gov (United States)

    Babcock, Walter C.

    1994-01-01

    Layered plasma polymer composite fluid separation membranes are disclosed, which comprise alternating selective and permeable layers for a total of at least 2n layers, where n is .gtoreq.2 and is the number of selective layers.

  16. Lithium carbon batteries with solid polymer electrolyte; Accumulateur lithium carbone a electrolyte solide polymere

    Energy Technology Data Exchange (ETDEWEB)

    Andrieu, X.; Boudin, F. [Alcatel Alsthom Recherche, 91 - Marcoussis (France)

    1996-12-31

    The lithium carbon batteries studied in this paper use plasticized polymer electrolytes made with passive polymer matrix swollen by a liquid electrolyte with a high ionic conductivity (> 10{sup -3} S/cm at 25 deg. C). The polymers used to prepare the gels are polyacrylonitrile (PAN) and vinylidene poly-fluoride (PVdF). The electrochemical and physical properties of these materials are analyzed according to their composition. The behaviour of solid electrolytes with different materials of lithium ion insertion (graphite and LiNiO{sub 2}) are studied and compared to liquid electrolytes. The parameters taken into account are the reversible and irreversible capacities, the cycling performance and the admissible current densities. Finally, complete lithium ion batteries with gelled electrolytes were manufactured and tested. (J.S.) 2 refs.

  17. An electroactive conducting polymer actuator based on NBR/RTIL solid polymer electrolyte

    Science.gov (United States)

    Cho, M. S.; Seo, H. J.; Nam, J. D.; Choi, H. R.; Koo, J. C.; Lee, Y.

    2007-04-01

    This paper reports the fabrication of a dry-type conducting polymer actuator using nitrile rubber (NBR) as the base material in a solid polymer electrolyte. The conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), was synthesized on the surface of the NBR layer by using a chemical oxidation polymerization technique. Room-temperature ionic liquids (RTIL) based on imidazolium salts, e.g. 1-butyl-3-methyl imidazolium X (where X = BF4-, PF6-, (CF3SO2)2N-), were absorbed into the composite film. The compatibility between the ionic liquids and the NBR polymer was confirmed by DMA. The effect of the anion size of the ionic liquids on the displacement of the actuator was examined. The displacement increased with increasing anion size of the ionic liquids. The cyclic voltammetry responses and the redox switching dynamics of the actuators were examined in different ionic liquids.

  18. 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].

  19. Lithium carbon batteries with solid polymer electrolyte; Accumulateur lithium carbone a electrolyte solide polymere

    Energy Technology Data Exchange (ETDEWEB)

    Andrieu, X; Boudin, F [Alcatel Alsthom Recherche, 91 - Marcoussis (France)

    1997-12-31

    The lithium carbon batteries studied in this paper use plasticized polymer electrolytes made with passive polymer matrix swollen by a liquid electrolyte with a high ionic conductivity (> 10{sup -3} S/cm at 25 deg. C). The polymers used to prepare the gels are polyacrylonitrile (PAN) and vinylidene poly-fluoride (PVdF). The electrochemical and physical properties of these materials are analyzed according to their composition. The behaviour of solid electrolytes with different materials of lithium ion insertion (graphite and LiNiO{sub 2}) are studied and compared to liquid electrolytes. The parameters taken into account are the reversible and irreversible capacities, the cycling performance and the admissible current densities. Finally, complete lithium ion batteries with gelled electrolytes were manufactured and tested. (J.S.) 2 refs.

  20. Structural, vibrational and electrical characterization of PVA-NH4Br polymer electrolyte system

    International Nuclear Information System (INIS)

    Hema, M.; Selvasekerapandian, S.; Sakunthala, A.; Arunkumar, D.; Nithya, H.

    2008-01-01

    Polymer electrolyte based on PVA doped with different concentrations of NH 4 Br has been prepared by solution casting technique. The complexation of the prepared polymer electrolytes has been studied using X-ray diffraction (XRD) and Fourier transform infra red (FTIR) spectroscopy. The maximum ionic conductivity (5.7x10 -4 S cm -1 ) has been obtained for 25 mol% NH 4 Br-doped PVA polymer electrolyte. The temperature dependence of ionic conductivity of the prepared polymer electrolytes obeys Arrhenius law. The ionic transference number of mobile ions has been estimated by dc polarization method and the results reveal that the conducting species are predominantly ions. The dielectric behavior of the polymer electrolytes has been analyzed using dielectric permittivity and electric modulus spectra

  1. Robust solid polymer electrolyte for conducting IPN actuators

    International Nuclear Information System (INIS)

    Festin, Nicolas; Maziz, Ali; Plesse, Cédric; Teyssié, Dominique; Chevrot, Claude; Vidal, Frédéric

    2013-01-01

    Interpenetrating polymer networks (IPNs) based on nitrile butadiene rubber (NBR) as first component and poly(ethylene oxide) (PEO) as second component were synthesized and used as a solid polymer electrolyte film in the design of a mechanically robust conducting IPN actuator. IPN mechanical properties and morphologies were mainly investigated by dynamic mechanical analysis and transmission electron microscopy. For 1-ethyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMITFSI) swollen IPNs, conductivity values are close to 1 × 10 −3 S cm −1 at 25 ° C. Conducting IPN actuators have been synthesized by chemical polymerization of 3,4-ethylenedioxythiophene (EDOT) within the PEO/NBR IPN. A pseudo-trilayer configuration has been obtained with PEO/NBR IPN sandwiched between two interpenetrated PEDOT electrodes. The robust conducting IPN actuators showed a free strain of 2.4% and a blocking force of 30 mN for a low applied potential of ±2 V. (paper)

  2. Robust solid polymer electrolyte for conducting IPN actuators

    Science.gov (United States)

    Festin, Nicolas; Maziz, Ali; Plesse, Cédric; Teyssié, Dominique; Chevrot, Claude; Vidal, Frédéric

    2013-10-01

    Interpenetrating polymer networks (IPNs) based on nitrile butadiene rubber (NBR) as first component and poly(ethylene oxide) (PEO) as second component were synthesized and used as a solid polymer electrolyte film in the design of a mechanically robust conducting IPN actuator. IPN mechanical properties and morphologies were mainly investigated by dynamic mechanical analysis and transmission electron microscopy. For 1-ethyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMITFSI) swollen IPNs, conductivity values are close to 1 × 10-3 S cm-1 at 25 ° C. Conducting IPN actuators have been synthesized by chemical polymerization of 3,4-ethylenedioxythiophene (EDOT) within the PEO/NBR IPN. A pseudo-trilayer configuration has been obtained with PEO/NBR IPN sandwiched between two interpenetrated PEDOT electrodes. The robust conducting IPN actuators showed a free strain of 2.4% and a blocking force of 30 mN for a low applied potential of ±2 V.

  3. Polymer electrolyte fuel cell mini power unit for portable application

    Energy Technology Data Exchange (ETDEWEB)

    Urbani, F.; Squadrito, G.; Barbera, O.; Giacoppo, G.; Passalacqua, E. [CNR-ITAE, via Salita S. Lucia sopra Contesse n. 5, 98126 S. Lucia, Messina (Italy); Zerbinati, O. [Universita del Piemonte Orientale, Dip. di Scienze dell' Ambiente e della Vita, via Bellini 25/g, 15100 Alessandria (Italy)

    2007-06-20

    This paper describes the design, realisation and test of a power unit based on a polymer electrolyte fuel cell, operating at room temperature, for portable application. The device is composed of an home made air breathing fuel cell stack, a metal hydride tank for H{sub 2} supply, a dc-dc converter for power output control and a fan for stack cooling. The stack is composed by 10 cells with an active surface of 25 cm{sup 2} and produces a rated power of 15 W at 6 V and 2 A. The stack successfully runs with end-off fed hydrogen without appreciable performance degradation during the time. The final assembled system is able to generate 12 W at 9.5 V, and power a portable DVD player for 3 h in continuous. The power unit has collected about 100 h of operation without maintenance. (author)

  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. Alkaline solid polymer electrolytes and their application to rechargeable batteries; Electrolytes solides polymeres alcalins application aux generateurs electrochimiques rechargeables

    Energy Technology Data Exchange (ETDEWEB)

    Guinot, S

    1996-03-15

    A new family of solid polymer electrolytes (SPE) based on polyoxyethylene (POE), KOH and water is investigated in view of its use in rechargeable batteries. After a short review on rechargeable batteries, the preparation of various electrolyte compositions is described. Their characterization by differential scanning calorimetry (DSC), thermogravimetric analysis, X-ray diffraction and microscopy confirm a multi-phasic structure. Conductivity measurements give values up to 10 sup -3 S cm sup -1 at room temperature. Their use in cells with nickel as negative electrode and cadmium or zinc as positive electrode has been tested; cycling possibility has been shown to be satisfactory. (C.B.) 113 refs.

  6. Dynamic NMR studies of polymer electrolyte materials for application to lithium-ion batteries and fuel cells

    Science.gov (United States)

    Khalfan, Amish N.

    This dissertation investigates the structural and dynamical properties of polymer electrolyte materials for applications to lithium-ion batteries and fuel cells. The nuclear magnetic resonance (NMR) technique was used to characterize these materials. NMR aids in understanding the local environments of nuclei and the mobility of a molecular/ionic species. Five research projects were carried out, and they have been outlined in this work. NASA has developed rod-coil block copolymers for use as electrolytes in lithium-ion batteries. The copolymers exhibit a microphase separation within their structure leading to the formation of ionically conducting channels. We studied ion transport properties of the copolymers, and determined the predominant mechanism for transport to occur in the amorphous phase. Seven gel polymer electrolytes, each containing a mixture of LiBETI salt and organic solvents, were studied. Two of them incorporated BMI (1-n-butyl-3-methylimidazolium) ionic liquid. Ionic liquids are room temperature molten salts. BMI had been thought to enhance ion mobility. However, the BMI component was observed to restrict ion mobility. Gel polymer electrolytes containing LiTFSI salt and P13TFSI ionic liquid with or without the inclusion of ethylene carbonate (EC) were studied for application to lithium metal/air batteries, which have high theoretical energy densities. The addition of EC was found to improve lithium ion transport. The gels with EC therefore prove to be favorable for use as electrolytes in lithium metal/air batteries. Highly sulfonated poly(arylenethioethersulfone) (SPTES) membranes were examined for use in direct methanol fuel cells (DMFCs) as an alternative to the Nafion membrane. DMFCs use methanol as a fuel instead of reformed hydrogen as in conventional proton exchange membrane fuel cells. Compared to Nafion, the SPTES membranes were shown to retain water better at high temperatures and yield lower methanol diffusion. SPTES membranes with the

  7. Ionomer composite membranes for H{sub 2}/O{sub 2} fuel cells, elaboration and characterization; Membranes ionomeres composites pour piles a combustibles H{sub 2}/O{sub 2}, elaboration et caracterisation

    Energy Technology Data Exchange (ETDEWEB)

    Baradie, B

    1997-07-01

    In order to propose an alternative to per-fluorinated membranes for polymer electrolyte fuel cells, several protonic conduction polymer membranes have been elaborated and their electrochemical and physical properties have been characterized, in particular, their mechanical and thermal stability. The first family of membranes is obtained by dispersion of a protonic superconducting inorganic powder (H{sub 3}Sb{sub 3}P{sub 2}O{sub 14}, xH{sub 2}O, = 10{sup -2}.cm{sup -1}) inside an EPDM commercial polymer matrix. Despite their relatively high conductivities, these composite membranes do not fulfill the expected requirements because of the ohmic drop they generate and of their gases permeability. In the second approach, a thermoplastic ionomer, PSS, has been selected has polymer matrix. PSS is prepared by sulfonation of poly(sulfonated ether arylene). These composite membranes fulfill the proton exchange membrane fuel cells (PEMFC) specifications, in particular in terms of thermal, mechanical and electrochemical stability. Their protonic conductivity is close to the one of Nafion 117 but their gas permeability is much lower than the one of Nafion 117. They have been successfully tested on a test bench during 500 hours. Finally, their relatively low price would allow to consider their industrial production in a near future. (J.S.)

  8. Preparation and characterization of nanocomposite polymer electrolytes poly(vinylidone fluoride)/nanoclay

    Energy Technology Data Exchange (ETDEWEB)

    Rahmawati, Suci A.; Sulistyaningsih,; Putro, Alviansyah Z. A.; Widyanto, Nugroho F.; Jumari, Arif; Purwanto, Agus; Dyartanti, Endah R., E-mail: endahrd@uns.ac.id [Research Group of Battery & Advanced Material, Department of Chemical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A Kentingan, Surakarta Indonesia 57126 (Indonesia)

    2016-02-08

    Polymer electrolytes are defined as semi solid electrolytes used as separator in lithium ion battery. Separator used as medium for transfer ions and to prevent electrical short circuits in battery cells. To obtain the optimal battery performance, separator with high porosity and electrolyte uptake is required. This can reduce the resistance in the transfer of ions between cathode and anode. The main objective of this work is to investigate the impact of different solvent (Dimethyl acetamide (DMAc), N-methyl-2-pyrrolidone (NMP) and dimethyl formamide (DMF)), pore forming agent poly(vinylpyrolidone) (PVP) and nanoclay as filler in addition of membrane using phase inversion method on the morphology, porosity, electrolyte uptake and degree of crystallinity. The membrane was prepared by the phase inversion method by adding PVP and Nanoclay using different solvents. The phase inversion method was prepared by dissolving Nanoclay and PVP in solvent for 1-2 hours, and then add the PVDF with stirring for 4 hours at 60°C. The membranes were characterized by porosity test, electrolyte uptake test, scanning electron microscope (SEM), and X-ray diffraction (XRD). The results showed that DMAc as solvent gives the highest value of porosity and electrolyte uptake. The addition of nanoclay and PVP enlarge the size of the pores and reduce the degree of crystallinity. So, the usage of DMAc as solvent is better than NMP or DMF.

  9. 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.

  10. Capacitive behavior studies on electrical double layer capacitor using poly (vinyl alcohol)–lithium perchlorate based polymer electrolyte incorporated with TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Chin-Shen; Teoh, K.H.; Liew, Chiam-Wen; Ramesh, S., E-mail: rameshtsubra@gmail.com

    2014-01-15

    Electric double layer capacitors (EDLCs) based on activated carbon electrodes and poly (vinyl alcohol)–lithium perchlorate (PVA–LiClO{sub 4})-nanosized titania (TiO{sub 2}) doped polymer electrolyte have been fabricated. Incorporation of TiO{sub 2} into PVA–LiClO{sub 4} system increases the ionic conductivity. The highest ionic conductivity of 1.3 × 10{sup −4} S cm{sup −1} is achieved at ambient temperature upon inclusion of 8 wt.% of TiO{sub 2}. Differential scanning calorimetry (DSC) analyses reveal that addition of TiO{sub 2} into polymer system increases the flexibility of polymer chain and favors the ion migration. Scanning electron microscopy (SEM) analyses display the surface morphology of the nanocomposite polymer electrolytes. The electrochemical stability window of composite polymer electrolyte is in the range of −2.3 V to 2.3 V as shown in cyclic voltammetry (CV) studies. The performance of EDLC is evaluated by electrochemical impedance spectroscopy (EIS), CV and galvanostatic charge–discharge technique. CV test discloses a nearly rectangular shape, which signifies the capacitive behavior of an ELDC. The EDLC containing composite polymer electrolyte gives higher specific capacitance value of 12.5 F g{sup −1} compared to non-composite polymer electrolyte with capacitance value of 3.0 F g{sup −1} in charge–discharge technique. The obtained specific capacitance of EDLC is in good agreement with each method used in this present work. Inclusion of filler into the polymer electrolyte enhances the electrochemical stability of EDLC. - Highlights: • PVA–LiClO{sub 4}–TiO{sub 2} possesses ionic conductivity value of 1.30 × 10{sup −4} S cm{sup −1}. • CV indicates the electrochemical stability window in the range of −2.3 V to 2.3 V. • The EDLC gives specific capacitance value of 12.5 F g{sup −1}.

  11. Temperature dependence of electrochemical properties of cross-linked poly(ethylene oxide)–lithium bis(trifluoromethanesulfonyl)imide–N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide solid polymer electrolytes for lithium batteries

    International Nuclear Information System (INIS)

    Wetjen, Morten; Kim, Guk-Tae; Joost, Mario; Winter, Martin; Passerini, Stefano

    2013-01-01

    Highlights: ► Solid-state electrolyte for lithium batteries. ► Polymer electrolyte with improved mechanical properties by cross-linking. ► Enhanced performance of polymer electrolytes using water- and air-stable ionic liquids as co-salts. ► Polymer electrolyte with high rate capability at moderate temperatures. - Abstract: An advanced electrochemical characterization of cross-linked ternary solid polymer electrolytes (SPEs), prepared by a solvent-free hot-pressing process, is reported. Ionic conductivity, electrochemical stability window and limiting current measurements were performed as a function of the temperature by using both potentiodynamic and galvanostatic techniques. Additionally, the lithium cycleability was evaluated with respect to its dependence on both the operating temperature and the current density by using a new multi-rate Li-stripping-plating procedure. The results clearly indicate the beneficial effect of higher operating temperatures on the rate-capability, without major degradation of the electrochemical stability of the SPE. All-solid-state lithium metal polymer batteries (LMPBs), comprising a lithium metal anode, the cross-linked ternary solid polymer electrolyte and a LiFePO 4 composite cathode, were manufactured and investigated in terms of the interdependencies of the delivered capacity, operating temperature and discharge rate. The results prove quite exceptional delivered capacities both at medium current densities at ambient temperatures and even more impressive capacities above 160 mAh g −1 at high discharge rates (1 C) and temperatures above 60 °C.

  12. Electrochemical properties of proton exchange membranes: the role of composition and microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Holdcroft, S.; Beattie, P.D.; Basura, V.I.; Schmeisser, J.; Chuy, C.; Orfino, F.; Ding, J. [Simon Fraser Univ., Burnaby, BC (Canada). Dept. of Chemistry

    2001-06-01

    To measure electrochemical and proton conduction properties of a large variety of different polyelectrolyte membranes that possess a wide array of equivalent weights and water contents, a number of analytical techniques were employed and the results presented in this paper. At the electrocatalyst/polymer electrolyte interface, kinetic and mass transport parameters play an important role in fuel cell operation, the authors used microelectrodes to study the effects of temperature and pressure on the electrochemical reduction of oxygen at platinum/solid polymer electrolyte interfaces in solid polymer electrolytes under controlled humidity. Under conditions of controlled humidity and temperature, proton conductivity was measured transverse and normal to the membrane surface using an alternate current (a.c.) impedance spectroscopy. A wide array of membranes were investigated, including those based on sulfonated polystyrene-block-hydrogenated butadiene, polystyrenesulfonic acid grafted onto ethylenetetrafluoroethylene, sulfonated trifluorostyrene-copolymers, and a novel series of membranes where the internal biphasic morphology is controlled to yield materials with low water and high conductivity and prepared in house. Transmission electron microscopy and small angle X-ray scattering was used for the analysis of the microstructure of selected membranes. Modelling the scattered intensities was used to quantify aspects of the microstructure.

  13. Quantitative characterization of water transport and flooding in the diffusion layers of polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Casalegno, A.; Colombo, L.; Galbiati, S.; Marchesi, R. [Department of Energy, Politecnico di Milano, via Lambruschini 4, 20156 Milano (Italy)

    2010-07-01

    Optimization of water management in polymer electrolyte membrane fuel cells (PEMFC) and in direct methanol fuel cells (DMFC) is a very important factor for the achievement of high performances and long lifetime. A good hydration of the electrolyte membrane is essential for high proton conductivity; on the contrary water in excess may lead to electrode flooding and severe reduction in performances. Many studies on water transport across the gas diffusion layer (GDL) have been carried out to improve these components; anyway efforts in this field are affected by lack of effective experimental methods. The present work reports an experimental investigation with the purpose to determine the global coefficient of water transport across different diffusion layers under real operating conditions. An appropriate and accurate experimental apparatus has been designed and built to test the single GDL under a wide range of operating conditions. Data analysis has allowed quantification of both the water vapor transport across different diffusion layers, and the effects of micro-porous layers; furthermore flooding onset and its consequences on the mass transport coefficient have been characterized by means of suitably defined parameters. (author)

  14. 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.

  15. Compliant gel polymer electrolyte based on poly(methyl acrylate-co-acrylonitrile)/poly(vinyl alcohol) for flexible lithium-ion batteries

    International Nuclear Information System (INIS)

    Ma, Xianguo; Huang, Xinglan; Gao, Jiandong; Zhang, Shu; Deng, Zhenghua; Suo, Jishuan

    2014-01-01

    Highlights: •Compliant gel polymer electrolyte based on P(MA-co-AN)/PVA is facilely prepared for flexible lithium-ion batteries. •The compliant gel polymer electrolyte displays high ionic conductivity, self-standing and mechanical flexible. •The compliant gel polymer electrolyte exhibits excellent chemical and electrochemical performances. -- Abstract: In this report, mechanically compliant gel polymer electrolyte (GPE) for flexible lithium-ion batteries is facilely fabricated. The GPE that based on the poly(methyl acrylate-co-acrylonitrile)/poly(vinyl alcohol) (P(MA-co-AN)/PVA) was prepared via emulsion polymerization. Herein, the P(MA-co-AN) copolymer is anticipated to exert beneficial for the bendability of the GPE, as well as swollen with the liquid electrolyte to provide a facile pathway for ion movement. The PVA serves as a stabilizer during the emulsion polymerization and a mechanical framework for the compliant polymer membrane. Performance benefits of the mechanically compliant membrane are elucidated in terms of mechanical behavior, thermostability and ionic conductivity. The GPE is still self-standing and mechanical flexible after swollen with liquid electrolyte. The GPE displays a conductivity of 0.98 mS cm −1 with the uptake electrolyte up to 150% of its own weight at 30 °C, excellent electrochemical stability window (5.2 V vs. Li/Li + ) and favorable interfacial characteristics. When used in flexible lithium-ion batteries, such a GPE demonstrates satisfactory compatibility with LiCoO 2 and graphite electrodes

  16. 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

  17. Alkaline polymer electrolyte fuel cells stably working at 80 °C

    Science.gov (United States)

    Peng, Hanqing; Li, Qihao; Hu, Meixue; Xiao, Li; Lu, Juntao; Zhuang, Lin

    2018-06-01

    Alkaline polymer electrolyte fuel cells are a new class of polymer electrolyte fuel cells that fundamentally enables the use of nonprecious metal catalysts. The cell performance mostly relies on the quality of alkaline polymer electrolytes, including the ionic conductivity and the chemical/mechanical stability. For a long time, alkaline polymer electrolytes are thought to be too weak in stability to allow the fuel cell to be operated at elevated temperatures, e.g., above 60 °C. In the present work, we report a progress in the state-of-the-art alkaline polymer electrolyte fuel cell technology. By using a newly developed alkaline polymer electrolyte, quaternary ammonia poly (N-methyl-piperidine-co-p-terphenyl), which simultaneously possesses high ionic conductivity and excellent chemical/mechanical stability, the fuel cell can now be stably operated at 80 °C with high power density. The peak power density reaches ca. 1.5 W/cm2 at 80 °C with Pt/C catalysts used in both the anode and the cathode. The cell works stably in a period of study over 100 h.

  18. Hydrogen production by electrochemical decomposition of formic acid via solid polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Ebru Oender [KOSGEB Bursa Business Development Center, Besevler Kucuk Sanayi Sitesi 16149 Nilufer/Bursa (Turkey); Koparal, Ali Savas; Oeguetveren, Uelker Bakir [Anadolu University, Iki Eylul Campus, Applied Research Center for Environmental Problems 26555 Eskisehir (Turkey); Anadolu University, Iki Eylul Campus, Department of Environmental Engineering, 26555 Eskisehir (Turkey)

    2009-01-15

    The aim of this work is to investigate the feasibility of simultaneous hydrogen production by electrochemical decomposition of formic acid via solid polymer electrolyte (SPE) in an electrochemical reactor. Titanium oxide coated with iridium oxide as anode and carbon fibre with Pt catalyst as cathode were used in the experiments. Effects of applied current density, flow rates and temperature of formic acid solution, concentration of supporting electrolyte and pH of the solution on performance of the process have been investigated. The effect of membrane thickness has also been examined. The results suggest that electrolysis using SPE is a promising method for the treatment of organic pollutants. Hydrogen with purity of 99.999% at ambient temperature by using carbon fibre cathode with Pt catalyst can be produced simultaneously and COD removal efficiency of 95% has been achieved not requiring any chemical addition and temperature increase. Also complete electrochemical oxidation of formic acid at the original pH to CO{sub 2} and H{sub 2}O without production of intermediate has been proved by HPLC analysis. (author)

  19. Utilization of methanol for polymer electrolyte fuel cells in mobile systems

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, V M [Research Centre Juelich (KFA), Inst. of Energy Process Engineering (Germany); Broeckerhoff, P [Research Centre Juelich (KFA), Inst. of Energy Process Engineering (Germany); Hoehlein, B [Research Centre Juelich (KFA), Inst. of Energy Process Engineering (Germany); Menzer, R [Research Centre Juelich (KFA), Inst. of Energy Process Engineering (Germany); Stimming, U [Research Centre Juelich (KFA), Inst. of Energy Process Engineering (Germany)

    1994-04-01

    The constantly growing volume of road traffic requires the introduction of new vehicle propulsion systems with higher efficiency and drastically reduced emission rates. As part of the fuel cell programme of the Research Centre Juelich a vehicle propulsion system with methanol as secondary energy carrier and a polymer electrolyte membrane fuel cell (PEMFC) as the main component for energy conversion is developed. The fuel gas is produced by a heterogeneously catalyzed steam reforming reaction in which methanol is converted to H[sub 2], CO and CO[sub 2]. The required energy is provided by the catalytic conversion of methanol for both heating up the system and reforming methanol. The high CO content of the fuel gas requires further processing of the gas or the development of new electrocatalysts for the anode. Various Pt-Ru alloys show promising behaviour as CO-tolerant anodes. The entire fuel cell system is discussed in terms of energy and emission balances. The development of important components is described and experimental results are discussed. (orig.)

  20. Transient non-isothermal model of a polymer electrolyte fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Shah, A.A. [Queen' s-RMC Fuel Cell Research Centre, 945 Princess Street, Kingston, Ont. K7L 5L9 (Canada); Kim, G.-S.; Harvey, D. [Ballard Power Systems, 4343 North Fraser Way, Burnaby, BC V5J 5J9 (Canada); Sui, P.C. [Institute for Integrated Energy Systems, University of Victoria, Victoria, BC V8W 3P6 (Canada)

    2007-01-01

    In this paper we present a one-dimensional transient model for the membrane electrode assembly of a polymer-electrolyte fuel cell. In earlier work we established a framework to describe the water balance in a steady-state, non-isothermal cathode model that explicitly included an agglomerate catalyst layer component. This paper extends that work in several directions, explicitly incorporating components of the anode, including a micro-porous layer, and accounting for electronic potential variations, gas convection and time dependance. The inclusion of temperature effects, which are vital to the correct description of condensation and evaporation, is new to transient modelling. Several examples of the modelling results are given in the form of potentiostatic sweeps and compared to experimental results. Excellent qualitative agreement is demonstrated, particularly in regard to the phenomenon of hysteresis, a manifestation of the sensitive response of the system to the presence of water. Results pertaining to pore size, contact angle and the presence of a micro-porous layer are presented and future work is discussed. (author)

  1. Ionic relaxation in PEO/PVDF-HFP-LiClO4 blend polymer electrolytes: dependence on salt concentration

    Science.gov (United States)

    Das, S.; Ghosh, A.

    2016-06-01

    In this paper, we have studied the effect of LiClO4 salt concentration on the ionic conduction and relaxation in poly ethylene oxide (PEO) and poly (vinylidene fluoride hexafluoropropylene) (PVDF-HFP) blend polymer electrolytes, in which the molar ratio of ethylene oxide segments to lithium ions (R  =  EO: Li) has been varied between 3 and 35. We have observed two phases in the samples containing low salt concentrations (R  >  9) and single phase in the samples containing high salt concentrations (R  ⩽  9). The scanning electron microscopic images indicate that there exists no phase separation in the blend polymer electrolytes. The temperature dependence of the ionic conductivity shows two slopes corresponding to high and low temperatures and follows Arrhenius relation for the samples containing low salt concentrations (R  >  9). The conductivity relaxation as well as the structural relaxation has been clearly observed at around 104 Hz and 106 Hz for these concentrations of the blended electrolytes. However, a single conductivity relaxation peak has been observed for the compositions with R  ⩽  9. The scaling of the conductivity spectra shows that the relaxation mechanism is independent of temperature, but depends on salt concentration.

  2. 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.

  3. Relation between water adsorption in polymer-electrolyte fuel cell and its electric power

    International Nuclear Information System (INIS)

    Fukada, Satoshi; Ohba, Kazuto; Nomura, Atsushi

    2013-01-01

    Highlights: • The amount of H 2 O adsorbed on a Nafion® 117 membrane under electricity generation is correlated as a function of its vapor pressure and temperature. • The amount of H 2 O adsorbed on the membrane is correlated whether the membrane is under a compression state or not. • The adsorption amount behaves differently under the condition where the membrane is compressed by an outside frame. • The difference in H 2 O adsorption amount between mounted and unmounted states is explained based on force acting on the membrane. • Relation between electric conductivity and adsorption amount of membrane is clarified. - Abstract: The amount of H 2 O adsorbed on a Nafion® 117 membrane mounted inside a polymer-electrolyte fuel cell (PEFC) system is determined as a function of temperature and H 2 O vapor pressure. Its experimental values are related with a product of electric current and terminal voltage when the anode and cathode compartments are supplied with partially moist (0% to 90% in relative humidity) H 2 and O 2 gases at atmospheric pressure, respectively. Under conditions of H 2 O vapor pressure lower than 2 × 10 4 Pa, the amount of H 2 O adsorbed on the membrane mounted inside the PEFC module is near to its original one that was determined under an unfixed force-free condition, where it is not mounted in cell. However, under conditions of H 2 O vapor pressure higher than 2 × 10 4 Pa, the adsorption amount under the mounted state becomes smaller than its original value determined under the unfixed force-free state. At the higher vapor pressure, the electric power generated under the mounted state also becomes lower than its value expected from the adsorption amount under the unfixed state. Thus, it is experimentally clarified that the FC power is deeply related with the amount of H 2 O adsorbed on the membrane. The H 2 O adsorption amount depends on whether it is compressed in a FC by an outside mold or not

  4. Influence of the Ionic Liquid Type on the Gel Polymer Electrolytes Properties

    Directory of Open Access Journals (Sweden)

    Juan P. Tafur

    2015-11-01

    Full Text Available Gel Polymer Electrolytes (GPEs composed by ZnTf2 salt, poly(vinylidene fluoride-co-hexafluoropropylene (PVdF-HFP, and different ionic liquids are synthesized using n-methyl-2-pyrrolidone (NMP as solvent. Three different imidazolium-based ionic liquids containing diverse cations and anions have been explored. Structural and electrical properties of the GPEs varying the ZnTf2 concentration are analyzed by ATR-FTIR, DSC, TG, and cyclic voltammetry. Free salt IL-GPEs present distinct behavior because they are influenced by the different IL cations and anions composition. However, inclusion of ZnTf2 salt inside the polymers provide GPEs with very similar characteristics, pointing out that ionic transport properties are principally caused by Zn2+ and triflate movement. Whatever the IL used, the presence of NMP solvent inside the polymer’s matrix turns out to be a key factor for improving the Zn2+ transport inside the GPE due to the interaction between Zn2+ cations and carbonyl groups of the NMP. High values of ionic conductivity, low activation energy values, and good voltammetric reversibility obtained regardless of the ionic liquid used enable these GPEs to be applied in Zn batteries. Capacities of 110–120 mAh·g−1 have been obtained for Zn/IL-GPE/MnO2 batteries discharged at −1 mA·cm−2.

  5. 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.

  6. 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.

  7. Effect of a novel amphipathic ionic liquid on lithium deposition in gel polymer electrolytes

    International Nuclear Information System (INIS)

    Choi, Nam-Soon; Koo, Bonjae; Yeon, Jin-Tak; Lee, Kyu Tae; Kim, Dong-Won

    2011-01-01

    Highlights: · Synthesis of a dimeric ionic liquid. · Gel polymer electrolytes providing uniform lithium deposit pathway. · An amphipathic ionic liquid locates at the interface between an electrolyte-rich phase and a polymer matrix in a gel polymer electrolyte. · The presence of PDMITFSI ionic liquid leads to the suppression of dendritic lithium formation on a lithium metal electrode. - Abstract: A novel dimeric ionic liquid based on imidazolium cation and bis(trifluoromethanesulfonyl) imide (TFSI) anion has been synthesized through a metathesis reaction. Its chemical shift values and thermal properties are identified via 1 H nuclear magnetic resonance (NMR) imaging and differential scanning calorimetry (DSC). The effect of the synthesized dimeric ionic liquid on the interfacial resistance of gel polymer electrolytes is described. Differences in the SEM images of lithium electrodes after lithium deposition with and without the 1,1'-pentyl-bis(2,3-dimethylimidazolium) bis(trifluoromethane-sulfonyl)imide (PDMITFSI) ionic liquid in gel polymer electrolytes are clearly discernible. This occurs because the PDMITFSI ionic liquid with hydrophobic moieties and polar groups modulates lithium deposit pathways onto the lithium metal anode. Moreover, high anodic stability for a gel polymer electrolyte with the PDMITFSI ionic liquid was clearly observed.

  8. Structural, thermal and ion transport properties of radiation grafted lithium conductive polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Nasef, Mohamed Mahmoud [Business and Advanced Technology Centre (BATC), Universiti Teknologi Malaysia, Jalan Semarak, 54100 Kuala Lumpur (Malaysia)]. E-mail: mahmoudeithar@mailcity.com; Saidi, Hamdani [Business and Advanced Technology Centre (BATC), Universiti Teknologi Malaysia, Jalan Semarak, 54100 Kuala Lumpur (Malaysia)

    2006-10-10

    Structural, thermal and ion transport properties of lithium conductive polymer electrolytes prepared by radiation-induced grafting of styrene onto poly(vinylidene fluoride) (PVDF) films and subsequent activation with LiPH{sub 6}/EC/DEC liquid electrolyte were investigated in correlation with the content of the grafted polystyrene (Y%). The changes in the structure were studied using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Thermal gravimetric analysis (TGA) was used to evaluate the thermal stability. The ionic conductivity was measured by means of ac impedance spectroscopy at various temperatures. The polymer electrolytes were found to undergo considerable structural and morphological changes that resulted in a noticeable increase in their ionic conductivity with the increase in Y% at various temperatures (25-65 deg. C). The ionic conductivity achieved a value of 1.61 x 10{sup -3} S cm{sup -1} when Y of the polymer electrolyte reached 50% and at 25 deg. C. The polymer electrolytes also showed a multi-step degradation behaviour and thermal stability up to 120 deg. C, which suits normal lithium battery operation temperature range. The overall results of this work suggest that the structural changes took place in PVDF matrix during the preparation of these polymer electrolytes have a strong impact on their various properties.

  9. Novel proton conducting polymer electrolytes based on polyparabanic acid doped with H 3PO 4 for high temperature fuel cell

    Science.gov (United States)

    Aihara, Yuichi; Sonai, Atsuo

    Three novel proton conducting polymer electrolytes based on polyparabanic acid doped with H 3PO 4 were synthesized and their use in high temperature fuel cells characterized. The precursor polymers, PMD-Im, POD-Im and PDMDP-Im, were synthesized by cyclization polymerization of diisocynanates. After doping with H 3PO 4, the ionic conductivity and the thermal degradation were studied by using the AC impedance method and thermal gravimetric analysis, respectively. These membranes showed high ionic conductivity of the order of 10 -2 S cm -1 at 423 K with good thermal stability. Their application to fuel cells was demonstrated and polarization curves were obtained at 423 K were obtained without humidification.

  10. Numerical Simulation of a Polymer electrolyte Fuel Cell; Simulacion Numerica de una Pila de combustible de Membrana Polimerica

    Energy Technology Data Exchange (ETDEWEB)

    San Fabian, D.; Naud, B.

    2005-07-01

    This document reproduces the final project of David San Fabian Ayuso, presented on May 26, 2005, for the obtention of the engineer degree of the Carlos III University of Madrid. A single-phase, isothermal model, including both electron and proton transport, is introduced for the simulation of polymer electrolyte fuel cells (PEM). The model is implemented in the commercial code Fluent 6.0, through the use of UDFs (User Defined Functions). In order to validate the model, a single canal of a PEM monocell is simulated in three dimensions. The obtained result are qualitatively satisfactory. It is observed that it is not essential to solve the current collectors when a monocell is considered (and not a stack). in the present study, the number of nodes is the computational grid appears to be too low in the membrane zone in order to make a complete validation of the model. (Author) 20 refs.

  11. A polymer electrolyte fuel cell stack for stationary power generation from hydrogen fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gottesfeld, S. [Los Alamos National Lab., NM (United States)

    1995-09-01

    The fuel cell is the most efficient device for the conversion of hydrogen fuel to electric power. As such, the fuel cell represents a key element in efforts to demonstrate and implement hydrogen fuel utilization for electric power generation. The low temperature, polymer electrolyte membrane fuel cell (PEMFC) has recently been identified as an attractive option for stationary power generation, based on the relatively simple and benign materials employed, the zero-emission character of the device, and the expected high power density, high reliability and low cost. However, a PEMFC stack fueled by hydrogen with the combined properties of low cost, high performance and high reliability has not yet been demonstrated. Demonstration of such a stack will remove a significant barrier to implementation of this advanced technology for electric power generation from hydrogen. Work done in the past at LANL on the development of components and materials, particularly on advanced membrane/electrode assemblies (MEAs), has contributed significantly to the capability to demonstrate in the foreseeable future a PEMFC stack with the combined characteristics described above. A joint effort between LANL and an industrial stack manufacturer will result in the demonstration of such a fuel cell stack for stationary power generation. The stack could operate on hydrogen fuel derived from either natural gas or from renewable sources. The technical plan includes collaboration with a stack manufacturer (CRADA). It stresses the special requirements from a PEMFC in stationary power generation, particularly maximization of the energy conversion efficiency, extension of useful life to the 10 hours time scale and tolerance to impurities from the reforming of natural gas.

  12. Synthesis and characterization of ionomers as polymer electrolytes for energy conversion devices

    Science.gov (United States)

    Oh, Hyukkeun

    group and a poly(ether ether ketone) backbone showed the highest proton conductivity and proton diffusion coefficient among the three ionomers, demonstrating the effect of the perfluorinated side chains. The proton conductivity of the novel ionomer was comparable to that of Nafion over a wide humidity range and temperature. A lithium perfluorosulfonate ionomer based on aromatic poly(arylene ether)s with pendant lithium perfluoroethyl sulfonates was prepared by ion exchange of the perlfuorosulfonic acid ionomer, and subsequently incoroporated into a lithium-ion battery cell as a single-ion conducting electrolyte. The microporous polymer film saturated with organic carbonates exhibited a nearly unity Li + transfer number, high ionic conductivity (e.g. > 10-3 S m-1 at room temperature) over a wide range of temperatures, high electrochemical stability, and excellent mechanical properties. Excellent cyclability with almost identical charge and discharge capacities have been demonstrated at ambient temperature in the batteries assembled from the prepared single-ion conductors. The mechanical stability of the polymer film was attributed to the rigid polymer backbone which was largely unaffected by the presence of plasticizing organic solvents, while the porous channels with high concentration of the perfluorinated side chains resulted in high ionic conductivity. The expected high charge-rate performance was not achieved, however, due to the high interfacial impedance present between the polymer electrolyte and the electrodes. Several procedural modifications were employed in order to decrease the interfacial impedance of the battery cell. The poly(arylene ether) based ionomer was saturated with an ionic liquid mixture, in order to explore the possibility of its application as a safe, inflammable electrolyte. A low-viscosity ionic liquid with high ionic conductivity, 1-butyl-3-methylimidazolium thiocyanate which has never been successfully utilized as an electrolyte for lithium

  13. 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.)

  14. Conductivity and properties of polysiloxane-polyether cluster-LiTFSI networks as hybrid polymer electrolytes

    Science.gov (United States)

    Boaretto, Nicola; Joost, Christine; Seyfried, Mona; Vezzù, Keti; Di Noto, Vito

    2016-09-01

    This report describes the synthesis and the properties of a series of polymer electrolytes, composed of a hybrid inorganic-organic matrix doped with LiTFSI. The matrix is based on ring-like oligo-siloxane clusters, bearing pendant, partially cross-linked, polyether chains. The dependency of the thermo-mechanic and of the transport properties on several structural parameters, such as polyether chains' length, cross-linkers' concentration, and salt concentration is studied. Altogether, the materials show good thermo-mechanical and electrochemical stabilities, with conductivities reaching, at best, 8·10-5 S cm-1 at 30 °C. In conclusion, the cell performances of one representative sample are shown. The scope of this report is to analyze the correlations between structure and properties in networked and hybrid polymer electrolytes. This could help the design of optimized polymer electrolytes for application in lithium metal batteries.

  15. 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)

    1997-12-31

    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.)

  16. New Microporous Polymer Electrolyte Based on Polysiloxane Grafted with Imidazolium Iodide Moieties for DSSC

    Directory of Open Access Journals (Sweden)

    Yan Yang

    2011-01-01

    Full Text Available Two types of polysiloxane grafted with different ratio of imidazolium iodide moieties (IL-SiO2 have been synthesized to develop a micro-porous polymer electrolyte for quasi-solid-state dye-sensitized solar cells. The samples were characterized by 1HNMR, FT-IR spectrum, XRD, TEM and SEM, respectively. Moreover, the ionic conductivity of the electrolytes was measured by electrochemical workstation. Nanostructured polysiloxane containing imidazolium iodide showed excellent compatibility with organic solvent and polymer matrix for its ionic liquid characteristics. Increasing the proportion of imidazolium iodide moieties in polysiloxane improved the electrochemical behavior of the gel polymer electrolyte. A dye-sensitized solar cell with gel polymer electrolyte yielded an open-circuit voltage of 0.70 V, short-circuit current of 11.19 mA cm−2, and the conversion efficiency of 3.61% at 1 sun illumination.

  17. Biosensors Based on Ultrathin Film Composite Membranes

    Science.gov (United States)

    1994-01-25

    composite membranes should have a number C •’ of potential advantages including fast response time, simplicity of construction, and applicability to a number...The support membrane for the ultrathin film composite was an Anopore ( Alltech Associates) microporous alumina filter, these membranes are 55 Pm thick...constant 02 concentration in this solution. Finally, one of the most important potential advantage of a sensor based on an ultrathin film composite

  18. 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

  19. Improved power conversion efficiency of dye-sensitized solar cells using side chain liquid crystal polymer embedded in polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Woosum [Department of Chemistry Education, and Department of Frontier Materials Chemistry, and Institute for Plastic Information and Energy Materials, Pusan National University, Busan 609-735 (Korea, Republic of); Lee, Jae Wook, E-mail: jlee@donga.ac.kr [Department of Chemistry, Dong-A University, Busan 604-714 (Korea, Republic of); Gal, Yeong-Soon [Polymer Chemistry Lab, College of General Education, Kyungil University, Hayang 712-701 (Korea, Republic of); Kim, Mi-Ra, E-mail: mrkim2@pusan.ac.kr [Department of Polymer Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Jin, Sung Ho, E-mail: shjin@pusan.ac.kr [Department of Chemistry Education, and Department of Frontier Materials Chemistry, and Institute for Plastic Information and Energy Materials, Pusan National University, Busan 609-735 (Korea, Republic of)

    2014-02-14

    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{sub 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{sub sc}, 10.75 mA cm{sup −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{sup −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.

  20. Composite membranes and methods for making same

    Science.gov (United States)

    Routkevitch, Dmitri; Polyakov, Oleg G

    2012-07-03

    Composite membranes that are adapted for separation, purification, filtration, analysis, reaction and sensing. The composite membranes can include a porous support structure having elongate pore channels extending through the support structure. The composite membrane also includes an active layer comprising an active layer material, where the active layer material is completely disposed within the pore channels between the surfaces of the support structure. The active layer is intimately integrated within the support structure, thus enabling great robustness, reliability, resistance to mechanical stress and thermal cycling, and high selectivity. Methods for the fabrication of composite membranes are also provided.

  1. Radiation Grafted Polymer Membranes for Fuel Cell Applications

    International Nuclear Information System (INIS)

    Scherer, G.G.; Wallasch, F.; Ben Youcef, H.; Gubler, L.

    2012-01-01

    Partially fluorinated proton exchange membranes prepared via radiation induced graft copolymerization ('radiation grafting') offer the prospect of cost-effective and tailor made membrane electrolytes for the polymer electrolyte fuel cell (PEFC). The composition and structure of radiation grafted membranes can be adjusted in a broad range to balance the different requirements of proton transport and mechanical robustness. Based on the earlier work on Styrene grafting, the novel monomer combination α-methyl-styrene/methacrylonitrile (AMS/MAN) is introduced for improved stability in the prevailing fuel cell environment. Successful fuel cell experiments proved the concept. (author)

  2. Radiation Grafted Polymer Membranes for Fuel Cell Applications

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, G G; Wallasch, F; Ben Youcef, H; Gubler, L [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen (Switzerland)

    2012-09-15

    Partially fluorinated proton exchange membranes prepared via radiation induced graft copolymerization ('radiation grafting') offer the prospect of cost-effective and tailor made membrane electrolytes for the polymer electrolyte fuel cell (PEFC). The composition and structure of radiation grafted membranes can be adjusted in a broad range to balance the different requirements of proton transport and mechanical robustness. Based on the earlier work on Styrene grafting, the novel monomer combination {alpha}-methyl-styrene/methacrylonitrile (AMS/MAN) is introduced for improved stability in the prevailing fuel cell environment. Successful fuel cell experiments proved the concept. (author)

  3. Transport and spectroscopic studies of liquid and polymer electrolytes

    Science.gov (United States)

    Bopege, Dharshani Nimali

    Liquid and polymer electrolytes are interesting and important materials to study as they are used in Li rechargeable batteries and other electrochemical devices. It is essential to investigate the fundamental properties of electrolytes such as ionic conductivity, diffusion, and ionic association to enhance battery performance in different battery markets. This dissertation mainly focuses on the temperature-dependent charge and mass transport processes and ionic association of different electrolyte systems. Impedance spectroscopy and pulsed field gradient nuclear magnetic resonance spectroscopy were used to measure the ionic conductivity and diffusion coefficients of ketone and acetate based liquid electrolytes. In this study, charge and mass transport in non-aqueous liquid electrolytes have been viewed from an entirely different perspective by introducing the compensated Arrhenius formalism. Here, the conductivity and diffusion coefficient are written as an Arrhenius-like expression with a temperature-dependent static dielectric constant dependence in the exponential prefactor. The compensated Arrhenius formalism reported in this dissertation very accurately describes temperature-dependent conductivity data for acetate and ketone-based electrolytes as well as temperature-dependent diffusion data of pure solvents. We found that calculated average activation energies of ketone-based electrolytes are close to each other for both conductivity and diffusion data (in the range 24-26 kJ/mol). Also, this study shows that average activation energies of acetate-based electrolytes are higher than those for the ketone systems (in the range 33-37 kJ/mol). Further, we observed higher dielectric constants and ionic conductivities for both dilute and concentrated ketone solutions with temperature. Vibrational spectroscopy (Infrared and Raman) was used to probe intermolecular interactions in both polymer and liquid electrolytes, particularly those which contain lithium

  4. New polymer electrolytes for low temperature fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sundholm, F.; Elomaa, M.; Ennari, J.; Hietala, S.; Paronen, M. [Univ. of Helsinki (Finland). Lab. of Polymer Chemistry

    1998-12-31

    Proton conducting polymer membranes for demanding applications, such as low temperature fuel cells, have been synthesised and characterised. Pre-irradiation methods are used to introduce sulfonic acid groups, directly or using polystyrene grafting, in stable, preformed polymer films. The membranes produced in this work show promise for the development of cost-effective, highly conducting membranes. (orig.)

  5. 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.

  6. 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.

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

    Science.gov (United States)

    Aliahmad, Nojan; Shrestha, Sudhir; Varahramyan, Kody; Agarwal, Mangilal

    2016-06-01

    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 × 10-3 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.

  8. Modeling Water Management in Polymer-Electrolyte Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Department of Chemical Engineering, University of California, Berkeley; Weber, Adam; Weber, Adam Z.; Balliet, Ryan; Gunterman, Haluna P.; Newman, John

    2007-09-07

    Fuel cells may become the energy-delivery devices of the 21st century with realization of a carbon-neutral energy economy. Although there are many types of fuel cells, polymerelectrolyte fuel cells (PEFCs) are receiving the most attention for automotive and small stationary applications. In a PEFC, hydrogen and oxygen are combined electrochemically to produce water, electricity, and waste heat. During the operation of a PEFC, many interrelated and complex phenomena occur. These processes include mass and heat transfer, electrochemical reactions, and ionic and electronic transport. Most of these processes occur in the through-plane direction in what we term the PEFC sandwich as shown in Figure 1. This sandwich comprises multiple layers including diffusion media that can be composite structures containing a macroporous gas-diffusion layer (GDL) and microporous layer (MPL), catalyst layers (CLs), flow fields or bipolar plates, and a membrane. During operation fuel is fed into the anode flow field, moves through the diffusion medium, and reacts electrochemically at the anode CL to form hydrogen ions and electrons. The oxidant, usually oxygen in air, is fed into the cathode flow field, moves through the diffusion medium, and is electrochemically reduced at the cathode CL by combination with the generated protons and electrons. The water, either liquid or vapor, produced by the reduction of oxygen at the cathode exits the PEFC through either the cathode or anode flow field. The electrons generated at the anode pass through an external circuit and may be used to perform work before they are consumed at the cathode. The performance of a PEFC is most often reported in the form of a polarization curve, as shown in Figure 2. Roughly speaking, the polarization curve can be broken down into various regions. First, it should be noted that the equilibrium potential differs from the open-circuit voltage due mainly to hydrogen crossover through the membrane (i.e., a mixed potential

  9. Pollen viability and membrane lipid composition

    NARCIS (Netherlands)

    Bilsen, van D.G.J.L.

    1993-01-01

    In this thesis membrane lipid composition is studied in relation to pollen viability during storage. Chapter 1 reviews pollen viability, membranes in the dry state and membrane changes associated with cellular aging. This chapter is followed by a study of age-related changes in phospholipid

  10. Solid-state supercapacitors with ionic liquid based gel polymer electrolyte: Effect of lithium salt addition

    Science.gov (United States)

    Pandey, G. P.; Hashmi, S. A.

    2013-12-01

    Performance characteristics of the solid-state supercapacitors fabricated with ionic liquid (IL) incorporated gel polymer electrolyte and acid treated multiwalled carbon nanotube (MWCNT) electrodes have been studied. The effect of Li-salt (LiPF6) addition in the IL (1-ethyl-3-methylimidazolium tris(pentafluoroethyl) trifluorophosphate, EMImFAP) based gel electrolyte on the performance of supercapacitors has been specifically investigated. The LiPF6/IL/poly(vinylidine fluoride-co-hexafluoropropylene) (PVdF-HFP) gel electrolyte film possesses excellent electrochemical window of 4 V (from -2.0 to 2.0 V), high ionic conductivity ∼2.6 × 10-3 S cm-1 at 20 °C and high enough thermal stability. The comparative performance of supercapacitors employing electrolytes with and without lithium salt has been evaluated by impedance spectroscopy and cyclic voltammetric studies. The acid-treated MWCNT electrodes show specific capacitance of ∼127 F g-1 with IL/LiPF6 containing gel polymer electrolyte as compared to that with the gel polymer electrolyte without Li-salt, showing the value of ∼76 F g-1. The long cycling stability of the solid state supercapacitor based on the Li-salt containing gel polymer electrolyte confirms the electrochemical stability of the electrolyte.

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

    Directory of Open Access Journals (Sweden)

    Omed Gh. Abdullah

    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. Keywords: Solid polymer electrolyte, XRD analysis, FTIR study, Optical band gap, Dielectric constant, Refractive index

  12. Development of Gel Polymer Electrolytes Using Radiation for Lithium Secondary Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jung Ki; Lee, Jun Young; Lee, Dong Jin [KAIST, Daejeon (Korea, Republic of)

    2010-05-15

    Recently, demands of high performance lithium battery are increased. Development of battery materials for high power, high capacity, high safety are also needed. This project deals with the new gel polymer electrolyte based on the microporous matrix with specific functions using radiation techniques.

  13. A new modified-serpentine flow field for application in high temperature polymer electrolyte fuel cell

    DEFF Research Database (Denmark)

    Singdeo, Debanand; Dey, Tapobrata; Gaikwad, Shrihari

    2017-01-01

    field design is proposed and its usefulness for the fuel cell applications are evaluated in a high-temperature polymer electrolyte fuel cell. The proposed geometry retains some of the features of serpentine flow field such as multiple bends, while modifications are made in its in-plane flow path...

  14. 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 : polymer electrolyte * 2-ethoxyethyl methacrylate * lithium -ion battery Subject RIV: CG - Electrochemistry Impact factor: 3.792, year: 2009

  15. 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 carbona...

  16. Engineered Asymmetric Composite Membranes with Rectifying Properties.

    Science.gov (United States)

    Wen, Liping; Xiao, Kai; Sainath, Annadanam V Sesha; Komura, Motonori; Kong, Xiang-Yu; Xie, Ganhua; Zhang, Zhen; Tian, Ye; Iyoda, Tomokazu; Jiang, Lei

    2016-01-27

    Asymmetric composite membranes with rectifying properties are developed by grafting pH-stimulus-responsive materials onto the top layer of the composite structure, which is prepared by two novel block copolymers using a phase-separation technique. This engineered asymmetric composite membrane shows potential applications in sensors, filtration, and nanofluidic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Development of materials and processes for low-cost production of high-temperature bipolar plates for use in polymer electrolyte membrane fuel cells (PEMFC). Final report; Material- und Verfahrensentwicklung fuer eine kostenguenstige Herstellung von Hochtemperatur-Bipolarplatten zum Einsatz in Polymer-Elektrolyt-Membran Brennstoffzellen (PEM-BZ). Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    In the context of the project 'Verfahren zur spritzgiesstechnischen Herstellung von HT-BPP' (processes for injection moulding of high-temperature fuel cells), bipolar plates for high-temperature proton exchange membrane fuel cells (HT-PEM-FC) were produced by an injection moulding process suited for mass production. This implied extensive material analyses of fillers and matrix materials. A specific compound for application in fuel cells and suited for mass production was produced on this basis. (orig./AKB)

  18. Membrane reactor technology for ultrapure hydrogen production

    NARCIS (Netherlands)

    Patil, Charudatta Subhash

    2005-01-01

    The suitability of polymer electrolyte membrane fuel cells (PEMFC) for stationary and vehicular applications because of its low operating temperatures, compactness, higher power density, cleaner exhausts and higher efficiencies compared to conventional internal combustion engines and gas turbines

  19. Ceramic nanostructure materials, membranes and composite layers

    NARCIS (Netherlands)

    Burggraaf, A.J.; Keizer, Klaas; van Hassel, B.A.

    1989-01-01

    Synthesis methods to obtain nanoscale materials will be briefly discussed with a focus on sol-gel methods. Three types of nanoscale composites (powders, membranes and ion implanted layers) will be discussed and exemplified with recent original research results. Ceramic membranes with a thickness of

  20. Composite perfluorohydrocarbon membranes, their preparation and use

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Yong; Bikson, Benjamin

    2017-04-04

    Composite porous hydrophobic membranes are prepared by forming a perfluorohydrocarbon layer on the surface of a preformed porous polymeric substrate. The substrate can be formed from poly (aryl ether ketone) and a perfluorohydrocarbon layer can be chemically grafted to the surface of the substrate. The membranes can be utilized for a broad range of fluid separations, such as microfiltration, nanofiltration, ultrafiltration as membrane contactors for membrane distillation and for degassing and dewatering of fluids. The membranes can further contain a dense ultra-thin perfluorohydrocarbon layer superimposed on the porous poly (aryl ether ketone) substrate and can be utilized as membrane contactors or as gas separation. membranes for natural gas treatment and gas dehydration.

  1. Mass transport aspects of polymer electrolyte fuel cells under two-phase flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, D.

    2007-03-15

    This well-illustrated, comprehensive dissertation by Dr. Ing. Denis Kramer takes an in-depth look at polymer electrolyte fuel cells (PEFC) and the possibilities for their application. First of all, the operating principles of polymer electrolyte fuel cells are described and discussed, whereby thermodynamics aspects and loss mechanisms are examined. The mass transport diagnostics made with respect to the function of the cells are discussed. Field flow geometry, gas diffusion layers and, amongst other things, liquid distribution, the influence of flow direction and the low-frequency behaviour of air-fed PEFCs are discussed. Direct methanol fuel cells are examined, as are the materials chosen. The documentation includes comprehensive mathematical and graphical representations of the mechanisms involved.

  2. Conductivity studies of PEG based polymer electrolyte for applications as electrolyte in ion batteries

    Science.gov (United States)

    Patil, Ravikumar V.; Praveen, D.; Damle, R.

    2018-05-01

    Development of lithium ion batteries employing solid polymer electrolytes as electrolyte material has led to efficient energy storage and usage in many portable devices. However, due to a few drawbacks like lower ionic conductivity of solid polymer electrolytes (SPEs), studies on SPEs for improvement in conductivity still have a good scope. In the present paper, we report the conductivity studies of a new SPE with low molecular weight poly ethylene glycol (PEG) as host polymer in which a salt with larger anion Lithium trifluro methane sulphonate (LTMS). XRD studies have revealed that the salt completely dissociates in the polymer giving a good stable electrolyte at lower salt concentration. Conductivity of the SPEs has been studied as a function of temperature and we reiterate that the conductivity is a thermally activated process and follows Arrhenius type behavior.

  3. Characterization of ι-carrageenan and its derivative based green polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Jumaah, Fatihah Najirah; Mobaraka, Nadhratun Naiim; Ahmad, Azizan; Ramli, Nazaruddin [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan (Malaysia)

    2013-11-27

    The new types of green polymer electrolytes based on ι-carrageenan derivative have been prepared. ι-carrageenan act as precursor was reacted with monochloroacetic acid to produce carboxymethyl ι-carrageenan. The powders were characterized by Attenuated Total Reflection Fourier Transform infrared (ATR-FTIR) spectroscopy and {sup 1}H nuclear magnetic resonance (NMR) to confirm the substitution of targeted functional group in ι-carrageenan. The green polymer electrolyte based on ι-carrageenan and carboxymethyl ι-carrageenan was prepared by solution-casting technique. The films were characterized by electrochemical impedance spectroscopy to determine the ionic conductivity. The ionic conductivity ι-carrageenan film were higher than carboxymethyl ι-carrageenan which 4.87 ×10{sup −6} S cm{sup −1} and 2.19 ×10{sup −8} S cm{sup −1}, respectively.

  4. Functional Polymer Electrolytes for Multidimensional All-Solid-State Lithium Batteries

    OpenAIRE

    Sun, Bing

    2015-01-01

    Pressing demands for high power and high energy densities in novel electrical energy storage units have caused reconsiderations regarding both the choice of battery chemistry and design. Practical concerns originating in the conventional use of flammable liquid electrolytes have renewed the interests of using solvent-free polymer electrolytes (SPEs) as solid ionic conductors for safer batteries. In this thesis work, SPEs developed from two polymer host structures, polyethers and polycarbonate...

  5. Study and development of a hydrogen/oxygen fuel cell in solid polymer electrolyte technology

    Energy Technology Data Exchange (ETDEWEB)

    Mosdale, R

    1992-10-29

    The hydrogen/oxygen fuel cell appears today as the best candidate to the replacing of the internal combustion engine for automobile traction. This system uses the non explosive electrochemical recombination of hydrogen and oxygen. It is a clean generator whom only reactive product is water. This thesis shows a theoretical study of this system, the synthesis of different kinds of used electrodes and finally an analysis of water movements in polymer electrolyte by different original technologies. 70 refs., 73 figs., 15 tabs.

  6. 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.

  7. 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

  8. 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)

    1997-12-31

    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.

  9. Light-cured polymer electrolytes for safe, low-cost and sustainable sodium-ion batteries

    Science.gov (United States)

    Colò, Francesca; Bella, Federico; Nair, Jijeesh R.; Gerbaldi, Claudio

    2017-10-01

    In this work we present a very simple preparation procedure of a poly(ethylene oxide) (PEO)-based crosslinked polymer electrolyte (XPE) for application in sodium-ion batteries (NIBs). The polymer electrolyte, containing NaClO4 as Na+ source, is prepared by rapid, energy saving, solvent-free photopolymerization technique, in a single step. Thermal, mechanical, morphological and electrochemical properties of the resulting XPE are thoroughly investigated. The highly ionic conducting (>1 mS cm-1 at 25 °C) polymer electrolyte is used in a lab-scale sodium cell with nanostructured TiO2 working electrode. The obtained results in terms of ambient temperature cycling behaviour (stable specific capacity of about 250 mAh g-1 at 0.1 mA cm-2 and overall remarkable stability, for a quasi-solid state Na polymer cell, upon very long term cycling exceeding 1000 reversible cycles at 0.5 mA cm-2 corresponding to > 5000 h of continuous operation) demonstrate the promising prospects of this novel XPE to be implemented in the next-generation NIBs conceived for large-scale energy storage systems, such as those connected to photovoltaic and wind factories.

  10. Ceria Based Composite Membranes for Oxygen Separation

    DEFF Research Database (Denmark)

    Gurauskis, Jonas; Ovtar, Simona; Kaiser, Andreas

    2014-01-01

    Mixed ionic-electronic conducting membranes for oxygen gas separation are attracting a lot of interest due to their promising potential for the pure oxygen and the syngas production. Apart from the need for a sufficiently high oxygen permeation fluxes, the prolonged stability of these membranes...... under the large oxygen potential gradients at elevated temperatures is decisive for the future applications. The gadolinium doped cerium oxide (CGO) based composite membranes are considered as promising candidates due to inherent stability of CGO phase. The CGO matrix is a main oxygen ion transporter......; meanwhile the primary role of a secondary phase in this membrane is to compensate the low electronic conductivity of matrix at intended functioning conditions. In this work thin film (15-20 μm) composite membranes based on CGO matrix and LSF electronic conducting phase were fabricated and evaluated...

  11. Resolving the three-dimensional microstructure of polymer electrolyte fuel cell electrodes using nanometer-scale X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Epting, William K.; Gelb, Jeff; Litster, Shawn

    2012-02-08

    The electrodes of a polymer electrolyte fuel cell (PEFC) are composite porous layers consisting of carbon and platinum nanoparticles and a polymer electrolyte binder. The proper composition and arrangement of these materials for fast reactant transport and high electrochemical activity is crucial to achieving high performance, long lifetimes, and low costs. Here, the microstructure of a PEFC electrode using nanometer-scale X-ray computed tomography (nano-CT) with a resolution of 50 nm is investigated. The nano-CT instrument obtains this resolution for the low-atomic-number catalyst support and binder using a combination of a Fresnel zone plate objective and Zernike phase contrast imaging. High-resolution, non-destructive imaging of the three-dimensional (3D) microstructures provides important new information on the size and form of the catalyst particle agglomerates and pore spaces. Transmission electron microscopy (TEM) and mercury intrusion porosimetry (MIP) is applied to evaluate the limits of the resolution and to verify the 3D reconstructions. The computational reconstructions and size distributions obtained with nano-CT can be used for evaluating electrode preparation, performing pore-scale simulations, and extracting effective morphological parameters for large-scale computational models. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Study on property-gradient polymer electrolyte for rechargeable lithium batteries; Lithium niji denchi no tame no keisha tokusei kobunshi denkaishitsu no sosei ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Kokumi, Z; Kanemura, S; Inaba, M; Takehara, Z; Yao, K; Uchimoto, Y [Kyoto University, Kyoto (Japan)

    1997-02-01

    This paper describes the fundamental experiments for creating property-gradient polymer electrolyte for rechargeable lithium batteries. The rechargeable lithium battery is composed of an anodic composite agent section with high ion conductivity, a separator equivalent section with high mechanical strength (high bridging degree), and a section surpressing the precipitation of metal lithium by contacting with it. The continuous property-gradient polymer electrolyte was tried to be synthesized by means of the plasma polymerization method. As a result, plasma polymerization electrolyte with high ion conductivity could be prepared from the liquid phase by using a monomer with low vapor pressure. Porous material simulating the anodic composite agent was impregnated by the monomer, which was plasma-polymerized. As a result, it was found that the bridging degree decreased from the surface towards the inside of the plasma-polymerized porous material. In addition, polymer was prepared using fluorine-base monomer. Thus, LiF thin film could be prepared through the reaction between the polymer and metal lithium. 3 figs.

  13. Synthesis of Carbon Nanotube (CNT Composite Membranes

    Directory of Open Access Journals (Sweden)

    Dusan Losic

    2010-12-01

    Full Text Available Carbon nanotubes are attractive approach for designing of new membranes for advanced molecular separation because of their unique transport properties and ability to mimic biological protein channels. In this work the synthetic approach for fabrication of carbon nanotubes (CNTs composite membranes is presented. The method is based on growth of multi walled carbon nanotubes (MWCNT using chemical vapour deposition (CVD on the template of nanoporous alumina (PA membranes. The influence of experimental conditions including carbon precursor, temperature, deposition time, and PA template on CNT growth process and quality of fabricated membranes was investigated. The synthesis of CNT/PA composites with controllable nanotube dimensions such as diameters (30–150 nm, and thickness (5–100 µm, was demonstrated. The chemical composition and morphological characteristics of fabricated CNT/PA composite membranes were investigated by various characterisation techniques including scanning electron microscopy (SEM, energy-dispersive x-ray spectroscopy (EDXS, high resolution transmission electron microscopy (HRTEM and x-ray diffraction (XRD. Transport properties of prepared membranes were explored by diffusion of dye (Rose Bengal used as model of hydrophilic transport molecule.

  14. Electrolytic membrane formation of fluoroalkyl polymer using a UV-radiation-based grafting technique and sulfonation

    Energy Technology Data Exchange (ETDEWEB)

    Shironita, Sayoko; Mizoguchi, Satoko; Umeda, Minoru, E-mail: mumeda@vos.nagaokaut.ac.jp [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka 940-2188, Niigata (Japan)

    2011-03-15

    A sulfonated fluoroalkyl graft polymer (FGP) membrane was prepared as a polymer electrolyte. First, the FGP membrane was grafted with styrene under UV irradiation. The grafted FGP was then sulfonated to functionalize it for proton conductivity. The grafting degree of the membrane increased with increasing grafting time during UV irradiation. The proton conductivity of the membrane increased with increasing grafting degree. The swelling ratio was independent of the grafting time, however, the water uptake increased with increasing grafting degree. Based on these results, it was found that the UV-initiated styrene grafting occurred along the membrane thickness direction. Moreover, the membrane was embedded within the glass fibers of the composite. This composite electrolytic membrane had 1.15 times the proton conductivity of a Nafion 117 membrane.

  15. Studies on polymer electrolyte poly(vinyl) pyrrolidone (PVP) complexed with ionic liquid: Effect of complexation on thermal stability, conductivity and relaxation behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Saroj, A.L. [Department of Physics, Banaras Hindu University, Varanasi, 221005 (India); Singh, R.K., E-mail: rksingh_17@rediffmail.com [Department of Physics, Banaras Hindu University, Varanasi, 221005 (India); Chandra, S. [Department of Physics, Banaras Hindu University, Varanasi, 221005 (India)

    2013-03-01

    Highlights: Black-Right-Pointing-Pointer PVP + IL based polymer electrolyte films have been prepared and studied. Black-Right-Pointing-Pointer The complexation/interaction of PVP with IL has been confirmed by FT-IR analysis. Black-Right-Pointing-Pointer The conductivity and relaxation frequency increases with increasing IL content. Black-Right-Pointing-Pointer Two relaxation peaks for complexed and uncomplexed PVP with IL have been observed. - Abstract: Polymer electrolyte films of PVP + x wt% ionic liquid (IL) (1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF{sub 4}]) for x = 0, 5, 10, 15, 20, 25 wt% have been prepared using solution cast technique. These films were characterized by TGA, DSC, FT-IR and ac impedance spectroscopy techniques. From XRD studies it is found that the inclusion of IL increases the amorphocity of polymeric membranes. DSC thermograms show that the glass transition (T{sub g}) and melting temperatures (T{sub m}) of PVP shift upon complexation with IL. FT-IR analysis shows the complexation of PVP with IL. Thermogravimetric studies show that PVP decomposes in a single step while PVP/IL membranes exhibit two step decomposition; lower value of decomposition temperature corresponds to the decomposition of PVP/IL complex while the higher decomposition temperature has been attributed to the decomposition of PVP. The decomposition temperature of PVP/IL complex decreases with the increasing amount of IL in the PVP membrane. Temperature dependence of conductivity and dielectric relaxation frequencies have also been studied for PVP and PVP/IL membranes. Both show thermally activated Arrhenius behaviour.

  16. A New All-Solid-State Hyperbranched Star Polymer Electrolyte for Lithium Ion Batteries: Synthesis and Electrochemical Properties

    International Nuclear Information System (INIS)

    Wang, Ailian; Xu, Hao; Zhou, Qian; Liu, Xu; Li, Zhengyao; Gao, Rui; Wu, Na; Guo, Yuguo; Li, Huayi; Zhang, Liaoyun

    2016-01-01

    Highlights: • A new hyperbranched multi-arm star polymer was successfully synthesized. • The star polymer electrolyte has good thermal stability and forming-film property. • The ion conductivity electrolyte can reach 8.3 × 10"−"5 S cm"−"1 at room temperature. • The star polymer electrolyte has wide electrochemical windows of 4.7 V. - Abstract: A new hyperbranched multi-arm star polymer with hyperbranched polystyrene (HBPS) as core and polymethyl methacrylate-block-poly(ethylene glycol) methyl ether methacrylate(PMMA-b-PPEGMA) as arms was firstly synthesized by atom transfer radical polymerization. The obtained hyperbranched multi-arm star polymer (HBPS-(PMMA-b-PPEGMA)_x) exhibited good thermal stability with a thermal decomposition temperature of 372 °C. The transparent, free-standing, flexible polymer electrolyte film of the blending of HBPS-(PMMA-b-PPEGMA)_x and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) was successfully fabricated by a solution casting method. The ionic conductivity of the hyperbranched star polymer electrolyte with a molar ratio of [EO]/[Li] of 30 could reach 8.3 × 10"−"5 S cm"−"1 at 30 °C (with the content of PPEGMA of 83.7%), and 2.0 × 10"−"4 S cm"−"1 at 80 °C (with the content of PPEGMA of 51.6%). The effect of the concentration of lithium salts on ionic conductivity was also investigated. The obtained all-solid-state polymer electrolyte possessed a wide electrochemical stability window of 4.7 V (vs. Li"+/Li), and a lithium-ion transference number (t_L_i"+) up to 0.31. The interfacial impedance of the fabricated LiÔöépolymer electrolyteÔöéLi symmetric cell based on hyperbranched star multi-arm polymer electrolyte exhibited good interfacial compatibility between all-solid-state polymer electrolyte and electrodes. The excellent properties of the hyperbranched star polymer electrolyte made it attractive as solid-state polymer electrolyte for lithium-ion batteries.

  17. Synthesis and characterisation of alkaline anionic-exchange membranes for direct alcohol fuel cells

    CSIR Research Space (South Africa)

    Nonjola, P

    2007-12-01

    Full Text Available , but the most important being proton exchange membrane fuel cell (PEMFC), which uses an acidic membrane like Nafion (sulfonated fluorocarbon polymers) as an electrolyte. The use of polymer electrolytes represents an interesting path to pursue...

  18. Formation of nanotubes in poly (vinylidene fluoride): Application as solid polymer electrolyte in DSC fabricated using carbon counter electrode

    Energy Technology Data Exchange (ETDEWEB)

    Muthuraaman, B. [Department of Energy, University of Madras, Guindy campus, Chennai 600025 (India); Maruthamuthu, P., E-mail: pmaruthu@yahoo.com [Department of Energy, University of Madras, Guindy campus, Chennai 600025 (India)

    2011-09-01

    Highlights: > Incorporation of a {pi}-electron donor compound as dopant in poly(vinylidene fluoride) along with redox couple (I{sup -}/I{sub 3}{sup -}) which forms brush like nanotubes. > Investigations about the use of conducting carbon coated FTO as a durable counter electrode and its effects in DSC. > High charge separation and the channelized flow of electrons in the nanotubes in electrolyte favors stable performance. - Abstract: In the present work, we report the incorporation of 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) in poly(vinylidene fluoride) (PVDF) along with the redox couple (I{sup -}/I{sub 3}{sup -}). When ABTS, a {pi}-electron donor, is used to dope PVDF, the polymer composite forms brush-like nanotubes and has been successfully used as a solid polymer electrolyte in dye-sensitized solar cells. Under the given conditions, the electrolyte composition forms nanotubes while it is doped with ABTS, a {pi}-electron donor. With this new electrolyte, a dye-sensitized solar cell was fabricated using N3 dye adsorbed over TiO{sub 2} nanoparticles as the photoanode and conducting carbon cement coated FTO as counter electrode.

  19. Hybrid Nano composite Membranes for PEMFC Applications

    International Nuclear Information System (INIS)

    Niepceron, F.

    2008-03-01

    This work aims at validating a new concept of hybrid materials for the realization of proton exchange membranes, an essential constituent of PEM fuel cells. The originality of this nano-composite hybrid concept corresponds to a separation of the membrane's properties. We investigated the preparation of composite materials based on an inert, relatively low cost, polymer matrix (PVDF-HFP) providing the mechanical stability embedding inorganic fillers providing the necessary properties o f proton-conduction and water retention. The first step of this work consisted in the modification of fumed silica to obtain a proton-conducting filler. An ionic exchange capacity (CEI) equal to 3 meq/g was obtained by the original grafting of sodium poly(styrene-sulfonate) chains from the surface of particles. Nano-composite hybrid membranes PVDF-HFP/functionalized silica were accomplished by a film casting process. The coupling of the morphological and physicochemical analyses validated the percolation of the inorganic phase for 30 wt.% of particles. Beyond 40 % of loading, measured protonic conductivity is higher than the reference membrane Nafion 112. Finally, these membranes presented high performances, above 0.8 W/cm 2 , in single-cell fuel cell tests. A compromise is necessary according to the rate of loading between performances in fuel cell and mechanical properties of the membrane. 50 % appeared as best choice with, until 90 C, a remarkable thermal stability of the performances. (author)

  20. Influence of membrane composition on its flexibility

    International Nuclear Information System (INIS)

    Gerbelli, B.B.; Teixeira da Silva, E.R.; Oliveira, C.L.P.; Oliveira, E.A.

    2012-01-01

    Full text: Lamellar phases and vesicles composed of lipids have been used as model systems to investigate biological process related to cell membrane as well as promising carriers for drugs and gene therapy. The composition of the membrane determines its three dimensional shape and its properties such as rigidity and compressibility which play an important role on membrane fusion, protein adhesion, interactions between proteins, etc. We present systematic study of a lamellar system composed mainly of lecithin which is a biocompatible phospholipid and simusol, which is a mixture of fatty acids that acts as a cosurfactant introducing flexibility to the membrane. Using X ray scattering we determine the lamellar periodicity as a function of the hydration for different formulations of the membrane; ranging from 100 % to 50 % mass fraction of lecithin. The X-ray spectra are fitted using a 4 Gaussian model [1]that allows us to determine the lamellar periodicity and the Caille parameter [2]. The ideal swelling law relating the membrane volume fraction (φ m ) to the lamellar periodicity (D) is given by φ m =δ m /D, where δ m is the thickness membrane, however, when steric interactions are dominant with respect to electrostatic and van der Waals interactions, deviations from this behavior are expected [3]. We present experimental data illustrating the swelling behavior for the membrane compositions and the respective behavior of the hydration limit, membrane Luzzati [4], of the Caille parameter and qualitative interpretation of the interaction forces the systems studying the parameter membrane square amplitude fluctuation[5]. [1] Private communication with Prof. Dr. Cristiano Luis Pinto de Oliveira. [2] Caille A. et all, Acad. Sci. Paris B274 (1972) 891. [3] E. Kurtisovski et all, PRL 98, 258103 (2007). [4] Nagle et all, Curr Opin Struct Biol. 2000 Aug;10(4):474-80. [5] H. I. Petrache. Structure and interactions of fluid phospholipids bilayers measured by high resolution

  1. Electrochemical characterizations on MnO2 supercapacitors with potassium polyacrylate and potassium polyacrylate-co-polyacrylamide gel polymer electrolytes

    KAUST Repository

    Lee, Kuang-Tsin

    2009-11-01

    MnO2·nH2O supercapacitors with potassium polyacrylate (PAAK) and potassium polyacrylate-co-polyacrylamide (PAAK-co-PAAM) gel polymer electrolytes (GPEs) having the weight compositions of polymer:KCl:H2O = 9%:6.7%:84.3% have been characterized for their electrochemical performance. Compared with the liquid electrolyte (LE) counterpart, the GPE cells exhibit remarkable (∼50-130%) enhancement in specific capacitance of the oxide electrode, and the extent of the enhancement increases with increasing amount of the carboxylate groups in the polymers as well as with increasing oxide/electrolyte interfacial area. In situ X-ray absorption near-edge structure (XANES) analysis indicates that the oxide electrodes of the GPE cells possess higher Mn-ion valences and are subjected to greater extent of valence variation than that of the LE cell upon charging/discharging over the same potential range. Copolymerization of PAAK with PAAM greatly improves the cycling stability of the MnO2·nH2O electrode, and the improvement is attributable to the alkaline nature of the amino groups. Both GPEs exhibit ionic conductivities greater than 1.0 × 10-1 S cm-1 and are promising for high-rate applications. © 2009 Elsevier Ltd. All rights reserved.

  2. Experimental studies on poly methyl methacrylate based gel polymer electrolytes for application in electrical double layer capacitors

    International Nuclear Information System (INIS)

    Hashmi, S A; Kumar, Ashok; Tripathi, S K

    2007-01-01

    Studies have been carried out on gel polymer electrolytes comprising poly methyl methacrylate (PMMA)-ethylene carbonate (EC)-propylene carbonate (PC)-salts, LiClO 4 , NaClO 4 and (C 2 H 5 ) 4 NClO 4 (TEAClO 4 ) with a view to using them as electrolytes in electrical double layer capacitors (EDLCs) based on activated charcoal powder electrodes. The optimum composition of gel electrolytes, PMMA (20 wt%)-EC : PC (1 : 1 v/v)-1.0 M salts exhibit high ionic conductivity of the order of ∼10 -3 S cm -1 at room temperature with good mechanical/dimensional stability, suitable for their application in EDLCs. The EDLCs have been characterized using linear sweep cyclic voltammetry, galvanostatic charge-discharge tests and ac impedance spectroscopy. The values of capacitance of 68-151 mF cm -2 (equivalent to single electrode specific capacitance of 38-78 Fg -1 of activated charcoal powder) have been observed. These values correspond to a specific energy of 5.3-10.8 Wh kg -1 and a power density of 0.19-0.22 kW kg -1 . The capacitance values have been observed to be stable up to 5000 voltammetric cycles or even more. A comparison of studies shows the predominant role of anions of the gel electrolytes in the capacitive behaviour of EDLCs

  3. Electrochemical characterizations on MnO2 supercapacitors with potassium polyacrylate and potassium polyacrylate-co-polyacrylamide gel polymer electrolytes

    KAUST Repository

    Lee, Kuang-Tsin; Lee, Jyh-Fu; Wu, Nae-Lih

    2009-01-01

    MnO2·nH2O supercapacitors with potassium polyacrylate (PAAK) and potassium polyacrylate-co-polyacrylamide (PAAK-co-PAAM) gel polymer electrolytes (GPEs) having the weight compositions of polymer:KCl:H2O = 9%:6.7%:84.3% have been characterized for their electrochemical performance. Compared with the liquid electrolyte (LE) counterpart, the GPE cells exhibit remarkable (∼50-130%) enhancement in specific capacitance of the oxide electrode, and the extent of the enhancement increases with increasing amount of the carboxylate groups in the polymers as well as with increasing oxide/electrolyte interfacial area. In situ X-ray absorption near-edge structure (XANES) analysis indicates that the oxide electrodes of the GPE cells possess higher Mn-ion valences and are subjected to greater extent of valence variation than that of the LE cell upon charging/discharging over the same potential range. Copolymerization of PAAK with PAAM greatly improves the cycling stability of the MnO2·nH2O electrode, and the improvement is attributable to the alkaline nature of the amino groups. Both GPEs exhibit ionic conductivities greater than 1.0 × 10-1 S cm-1 and are promising for high-rate applications. © 2009 Elsevier Ltd. All rights reserved.

  4. Electrical and mechanical properties of poly(ethylene oxide)/intercalated clay polymer electrolyte

    International Nuclear Information System (INIS)

    Moreno, Mabel; Quijada, Raúl; Santa Ana, María A.; Benavente, Eglantina; Gomez-Romero, Pedro; González, Guillermo

    2011-01-01

    Highlights: ► Poly(ethylene oxide)/intercalated clay nanocomposite as filler in solid poly(ethylene oxide) electrolytes. ► Nanocomposite filler improves mechanical properties, transparency, and conductivity of poly(ethylene oxide) electrolyte films. ► Nanocomposite is more effective than unmodified clay in improving polymer electrolyte properties. ► Low Li/polymer ratio avoids crystalline Li complexes, so effects mainly arise from the polymer. ► High nanocomposite/poly(ethylene oxide)-matrix affinity enhances microhomogeneity in the polyelectrolyte. - Abstract: Solvent-free solid polymer electrolytes (SPEs) based on two different poly(ethylene oxide), PEO Mw 600,000 and 4,000,000 and intercalated clays are reported. The inorganic additives used were lithiated bentonite and the nanocomposite PEO-bentonite with the same polymer used as matrix. SPE films, obtained in the scale of grams by mixing the components in a Brabender-type batch mixer and molding at 130 °C, were characterized by X-ray diffraction analysis, UV–vis spectroscopy, and thermal analysis. During the preparation of the films, the unmodified clay got intercalated in situ. Comparative analysis of ionic conductivity and mechanical properties of the films show that the conductivity increases with the inclusion of fillers, especially for the polymer with low molecular weight. This effect is more pronounced when using PEO-bentonite as additive. Under selected work conditions, avoiding the presence of crystalline lithium complexes, observed effects are mainly centered on the polymer. An explanation, considering the higher affinity between the modified clay and PEO matrix which leads to differences in the micro homogeneity degree between both types of polymer electrolytes is proposed.

  5. Thermostable gel polymer electrolyte based on succinonitrile and ionic liquid for high-performance solid-state supercapacitors

    Science.gov (United States)

    Pandey, Gaind P.; Liu, Tao; Hancock, Cody; Li, Yonghui; Sun, Xiuzhi Susan; Li, Jun

    2016-10-01

    A flexible, free-standing, thermostable gel polymer electrolyte based on plastic crystalline succinonitrile (SN) and ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF4) entrapped in copolymer poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) is prepared and optimized for application in solvent-free solid-state supercapacitors. The synthesized gel polymer electrolyte exhibits a high ionic conductivity over a wide temperature range (from ∼5 × 10-4 S cm-1 at -30 °C up to ∼1.5 × 10-2 S cm-1 at 80 °C) with good electrochemical stability window (-2.9 to 2.5 V). Thermal studies confirm that the SN containing gel polymer electrolyte remains stable in the same gel phase over a wide temperature range from -30 to 90 °C. The electric double layer capacitors (EDLCs) have been fabricated using activated carbon as active materials and new gel polymer electrolytes. Electrochemical performance of the EDLCs is assessed through cyclic voltammetry, galvanostatic charge-discharge cycling and impedance spectroscopy. The EDLC cells with the proper SN-containing gel polymer electrolyte has been found to give high specific capacitance 176 F g-1 at 0.18 A g-1 and 138 F g-1 at 8 A g-1. These solid-state EDLC cells show good cycling stability and the capability to retain ∼80% of the initial capacitance after 10,000 cycles.

  6. Composite Membranes Based on Polyether Sulfone

    Directory of Open Access Journals (Sweden)

    A. Soroush

    2010-12-01

    Full Text Available The role of polymeric additives such as PVP and PEG is studied with respect to the morphology of PES porous layer as a sublayer of nanofiltration composite membranes based on PES/PA. Results show that by phase inversionprocess of quaternary systems comprised of four components of polymer/solvent/non-solvent/additive and the diffusion of intertwined polymers some changes occur in membrane morphology with changes in their concentration. With addition of PVP, tear-like pores, finger-like and channel-like morphology change to enlarged channel cavities and by adding more PVP, membrane morphology changes further and spongy regions are extended in the membrane. Presence of PEG in casting solution delayed the precipitation time. By adding PEG, the solution viscosity is increased which is followed by decreases in diffusion rates of solvent/non-solvent in coagulation bath.Therefore, membrane morphology shifts to small pores and spongier region. Another effect of increased PEG content would be deformed PA layer formation in PES sublayer which affects membrane performance. However, PVP as an additive does not change membrane salt rejection very much while it leads to higher fluxes. A membrane with 2.5 percent PVP would perform by 40 percent flux increases, while a membrane with 5% PVP shows flux reductions even below the initial value. Contrary to PVP, the PEG content of 20 percent leads to 4 folds flux increases and in a membrane with 50 percent PEG, there is a flux increase by 7 folds and drop in salt rejection occurs by 50 percent and 70 percent, respectively.

  7. Ionic conductivity and dielectric permittivity of polymer electrolyte plasticized with polyethylene glycol

    Science.gov (United States)

    Das, S.; Ghosh, A.

    2016-05-01

    We have studied ionic conductivity and dielectric permittivity of PEO-LiClO4 solid polymer electrolyte plasticized with polyethylene glycol (PEG). The temperature dependence of the ionic conductivity has been well interpreted using Vogel-Tamman-Fulcher equation. The maximum dielectric constant is observed for 30 wt. % of PEG content. To get further insights into the ion dynamics, the complex dielectric permittivity has been studied with Havriliak-Negami function. The variation of relaxation time with inverse temperature obtained from HN formalism follows VTF nature.

  8. Optical absorption studies on biodegradable PVA/PVP blend polymer electrolyte system

    Science.gov (United States)

    Basha, S. K. Shahenoor; Reddy, K. Veera Bhadra; Rao, M. C.

    2018-05-01

    Biodegradable blend polymer electrolytes of PVA/PVP with different wt% ratios of MgCl2.6H2O have been prepared using solution cast technique. Optical absorption studies were carried-out on to the prepared films at room temperature using JASCO V-670 Spectrophotometer in the wavelength region 200-600 nm. Due to the clusters between the vibrations of molecules a broad peak is obtained due to п-п* transition in the wavelength region 310-340 nm.

  9. 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)

  10. Pseudo one-dimensional analysis of polymer electrolyte fuel cell cold-start

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Partha P [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Borup, Rodney L [Los Alamos National Laboratory; Wang, Yun [NON LANL; Mishlera, Jeff [NON LANL

    2009-01-01

    This paper investigates the electrochemical kinetics, oxygen transport, and solid water formation in polymer electrolyte fuel cell (PEFC) during cold start. Following [Yo Wang, J. Electrochem. Soc., 154 (2007) B1041-B1048], we develop a pseudo one-dimensional analysis, which enables the evaluation of the impact of ice volume fraction and temperature variations on cell performance during cold-start. The oxygen profile, starvation ice volume fraction, and relevant overpotentials are obtained. This study is valuable for studying the characteristics of PEFC cold-start.

  11. Status of solid polymer electrolyte fuel cell technology and potential for transportation applications

    Science.gov (United States)

    McElroy, J. F.; Nuttall, L. J.

    The solid polymer electrolyte (SPE) fuel cell represents the first fuel cell technology known to be used operationally. Current activities are mainly related to the development of a space regenerative fuel cell system for energy storage on board space stations, or other large orbiting vehicles and platforms. During 1981, a study was performed to determine the feasibility of using SPE fuel cells for automotive or other vehicular applications, using methanol as the fuel. The results of this study were very encouraging. Details concerning a conceptual automotive fuel cell power plant study are discussed, taking into account also a layout of major components for compact passenger car installation.

  12. NMR studies of Na+-anion association effects in polymer electrolytes

    International Nuclear Information System (INIS)

    Greenbaum, S.G.; Pak, Y.S.; Wintergill, M.C.; Fontanella, J.J.

    1988-01-01

    23 Na nuclear magnetic resonance (NMR) measurements on poly (propylene oxide) (PPO) and siloxane based polymer electrolytes containing various sodium salts at a single nominal concentration are reported. In addition, differential scanning calorimetry (DSC) and electrical conductivity studies were carried out on the PPO materials. The NMR-determined mobile Na + concentrations and DSC results provide evidence for ionic aggregation effects which, for some samples, result in salt precipitation at elevated temperatures. 23 Na chemical shifts observed in solid state NMR due to mobile Na + -anion interactions influence ionic transport as well as the number of available carriers. (author). 19 refs.; 7 figs

  13. Solid-State NMR Study of New Copolymers as Solid Polymer Electrolytes

    Directory of Open Access Journals (Sweden)

    Jean-Christophe Daigle

    2018-01-01

    Full Text Available We report the analysis of comb-like polymers by solid-state NMR. The polymers were previously evaluated as solid-polymer-electrolytes (SPE for lithium-polymer-metal batteries that have suitable ionic conductivity at 60 °C. We propose to develop a correlation between 13C solid-state NMR measurements and phase segregation. 13C solid-state NMR is a perfect tool for differentiating polymer phases with fast or slow motions. 7Li was used to monitor the motion of lithium ions in the polymer, and activation energies were calculated.

  14. Properties of solid polymer electrolyte fluorocarbon film. [used in hydrogen/oxygen fuel cells

    Science.gov (United States)

    Alston, W. B.

    1973-01-01

    The ionic fluorocarbon film used as the solid polymer electrolyte in hydrogen/oxygen fuel cells was found to exhibit delamination failures. Polarized light microscopy of as-received film showed a lined region at the center of the film thickness. It is shown that these lines were not caused by incomplete saponification but probably resulted from the film extrusion process. The film lines could be removed by an annealing process. Chemical, physical, and tensile tests showed that annealing improved or sustained the water contents, spectral properties, thermo-oxidative stability, and tensile properties of the film. The resistivity of the film was significantly decreased by the annealing process.

  15. Anion-conducting polymer, composition, and membrane

    Science.gov (United States)

    Pivovar, Bryan S [Los Alamos, NM; Thorn, David L [Los Alamos, NM

    2009-09-01

    Anion-conducing polymers and membranes with enhanced stability to aqueous alkali include a polymer backbone with attached sulfonium, phosphazenium, phosphazene, and guanidinium residues. Compositions also with enhanced stability to aqueous alkali include a support embedded with sulfonium, phosphazenium, and guanidinium salts.

  16. Quasi-solid polymer electrolytes using photo-cross-linked polymers. Lithium and divalent cation conductors and their applications

    Science.gov (United States)

    Ikeda, Shoichiro; Mori, Yoichi; Furuhashi, Yuri; Masuda, Hideki; Yamamoto, Osamu

    In this report, we will present the results on the photo-cross-linked poly-(ethylene glycol) diacrylate (PEGDA) based quasi-solid, i.e. gel, polymer electrolyte systems with lithium, magnesium and zinc trifluoromethanesulfonates [triflate; M n(CF 3SO 3) n] and their preliminary applications to primary cells. The Celgard® membrane-impregnated electrolytes were prepared in the same manner as Abraham et al. [K.M. Abraham, M. Alamgir, D.K. Hoffman, J. Electrochem. Soc. 142 (1995) 683]. The precursor solutions were composed of metal triflates, ethylene carbonate, propylene carbonate, and tetraethylene glycol diacrylate. The Celgard® #3401 membrane was soaked overnight in the precursor solution, then clamped between two Pyrex glass plates and irradiated with UV light to form a gel electrolyte. The maxima of the conductivity obtained were 4.5×10 -4 S cm -1 at 12 mol% for LiCF 3SO 3, 1.7×10 -4 S cm -1 at 1 mol% for Mg(CF 3SO 3) 2, and 2.1×10 -4 S cm -1 at 4 mol% for Zn(CF 3SO 3) 2 system, respectively. The Arrhenius plots of the conductivities are almost linear between 268 and 338 K with 15-25 kJ/mol of activation energy for conduction. The cell, Li|LiCF 3SO 3-SPE+Celgard® #3401|(CH 3) 4NI 5+acetylene black, showed 2.86 V of OCV and could discharge up to 25% with respect to the cathode active material at a discharging current of 0.075 mA/cm 2.

  17. Quasi-solid polymer electrolytes using photo-cross-linked polymers. Lithium and divalent cation conductors and their applications

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Shoichiro; Mori, Yoichi; Furuhashi, Yuri; Masuda, Hideki [Nagoya Inst. of Tech. (Japan). Dept. of Applied Chemistry; Yamamoto, Osamu [Mie Univ., Tsu (Japan). Dept. of Chemistry

    1999-09-01

    In this report, we will present the results on the photo-cross-linked poly-(ethylene glycol) diacrylate (PEGDA) based quasi-solid, i.e. gel, polymer electrolyte systems with lithium, magnesium and zinc trifluoromethanesulfonates [triflate; M{sup n}(CF{sub 3}SO{sub 3}){sub n}] and their preliminary applications to primary cells. The Celgard{sup trademark} membrane-impregnated electrolytes were prepared in the same manner as Abraham et al. [K.M. Abraham, M. Alamgir, D.K. Hoffmann, J. Electrochem. Soc. 142 (1995) 683]. The precursor solutions were composed of metal triflates, ethylene carbonate, propylene carbonate, and tetraethylene glycol diacrylate. The Celgard{sup trademark} aa3401 membrane was soaked overnight in the precursor solution, then clamped between two Pyrex glass plates and irradiated with UV light to form a gel electrolyte. The maxima of the conductivity obtained were 4.5 x 10{sup -4} S cm{sup -1} at 12 mol% for LiCF{sub 3}SO{sub 3}, 1.7 x 10{sup -4} S cm{sup -1} at 1 mol% for Mg(CF{sub 3}SO{sub 3}){sub 2}, and 2.1 x 10{sup -4} S cm{sup -1} at 4 mol% Zn(CF{sub 3}SO{sub 3}){sub 2} system, respectively. The Arrhenius plots of the conductivities are almost linear between 268 and 338 K with 15-25 kJ/mol of activation energy for conduction. The cell, li vertical stroke LiCF{sub 3}SO{sub 3}-SPE+Celgard{sup trademark} aa3401 vertical stroke (CH{sub 3}){sub 4}NI{sub 5}+acetylene black, showed 2.86 V of OCV and could discharge up to 25% with respect to the cathode active material at a discharging current of 0.075 mA/cm{sup 2}. (orig.)

  18. Conductivity enhancement in SiO2 doped PVA:PVDF nanocomposite polymer electrolyte by gamma ray irradiation

    Science.gov (United States)

    Hema, M.; Tamilselvi, P.; Pandaram, P.

    2017-07-01

    Nanocomposite polymer electrolyte has been irradiated with 15 Gy Gamma rays. Exposure of gamma radiation caused scissoring and crosslinking of polymer chains thereby increasing amorphous phase of the polymer matrix because of which the ionic conductivity has been enhanced. Ionic conductivity of irradiated nanocomposite polymer electrolyte is enhanced to 9.4 × 10-4 Scm-1 at 303 K compared to un-irradiated system (σ ∼ 1.7 × 10-4 Scm-1). Temperature dependence of ionic conductivity of both un-irradiated and irradiated systems obeys VTF relation. Frequency and temperature dependence of dielectric and modulus of both systems have been analyzed. The ionic transference number of polymer electrolyte has been calculated by Wagner's polarization technique and it confirms that conducting species are predominantly due to ions in both systems.

  19. Effect of nanosized silica in poly(methyl methacrylate)-lithium bis(trifluoromethanesulfonyl)imide based polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh, S.; Lu, Soon-Chien [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Setapak, 53300 Kuala Lumpur (Malaysia)

    2008-12-01

    The effect of nanosized silica when incorporated in polymer electrolytes is analyzed by means of Fourier transform infrared (FTIR) spectroscopy, conductivity and thermal properties. Nanocomposite polymer electrolytes are synthesized by the dispersion of nanosized silica (SiO{sub 2}), up to 10 wt.% maximum, into a matrix formed by poly(methyl methacrylate) (PMMA) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The highest conductivity is 2.44 x 10{sup -6} S cm{sup -1} at room temperature, with 4 wt.% of silica added. The FTIR spectra show evidence of complexation between PMMA, LiTFSI and SiO{sub 2}. The addition of silica to the polymer electrolytes also improves the thermal stability and the ability to retain conductivity over time. (author)

  20. Characterization of proton conducting blend polymer electrolyte using PVA-PAN doped with NH{sub 4}SCN

    Energy Technology Data Exchange (ETDEWEB)

    Premalatha, M. [PG & Research Department of Physics, N.M.S.S.Vellaichamy Nadar College, Madurai-625 019 (India); Materials Research Center, Coimbatore-641 045 (India); Mathavan, T., E-mail: tjmathavan@gmail.com, E-mail: kingslin.genova20@gmail.com [PG & Research Department of Physics, N.M.S.S.Vellaichamy Nadar College, Madurai-625 019 (India); Selvasekarapandian, S. [Materials Research Center, Coimbatore-641 045 (India); Genova, F. Kingslin Mary, E-mail: tjmathavan@gmail.com, E-mail: kingslin.genova20@gmail.com; Umamaheswari, R. [Department of physics, S.F.R College for Women, Sivakasi-626 128 (India)

    2016-05-23

    Polymer electrolytes with proton conductivity based on blend polymer using polyvinyl alcohol (PVA) and poly acrylo nitrile (PAN) doped with ammonium thiocyanate have been prepared by solution casting method using DMF as solvent. The complex formation between the blend polymer and the salt has been confirmed by FTIR Spectroscopy. The amorphous nature of the blend polymer electrolytes have been confirmed by XRD analysis. The highest conductivity at 303 K has been found to be 3.25 × 10{sup −3} S cm{sup −1} for 20 mol % NH{sub 4}SCN doped 92.5PVA:7.5PAN system. The increase in conductivity of the doped blend polymer electrolytes with increasing temperature suggests the Arrhenius type thermally activated process. The activation energy is found to be low (0.066 eV) for the highest conductivity sample.

  1. SAXS Studies of TiO2 Nanoparticles in Polymer Electrolytes and in Nanostructured Films

    Directory of Open Access Journals (Sweden)

    Sigrid Bernstorff

    2010-11-01

    Full Text Available Polymer electrolytes as nanostructured materials are very attractive components for batteries and opto-electronic devices. (PEO8ZnCl2 polymer electrolytes were prepared from PEO and ZnCl2. The nanocomposites (PEO8ZnCl2/TiO2 themselves contained TiO2 nanograins. In this work, the influence of the TiO2 nanograins on the morphology and ionic conductivity of the nanocomposite was systematically studied by transmission small-angle X-ray scattering (SAXS simultaneously recorded with wide-angle X-ray diffraction (WAXD and differential scanning calorimetry (DSC at the synchrotron ELETTRA. Films containing nanosized grains of titanium dioxide (TiO2 are widely used in the research of optical and photovoltaic devices. The TiO2 films, prepared by chemical vapor deposition and e-beam epitaxy, were annealed in hydrogen atmospheres in the temperature range between 20 °C and 900 °C in order to study anatase-rutile phase transition at 740 °C. Also, grazing-incidence small angle X-ray scattering (GISAXS spectra for each TiO2 film were measured in reflection geometry at different grazing incident angles. Environmentally friendly galvanic cells, as well as solar cells of the second generation, are to be constructed with TiO2 film as working electrode, and nanocomposite polymer as electrolyte.

  2. Incorporating allylated lignin-derivatives in thiol-ene gel-polymer electrolytes.

    Science.gov (United States)

    Baroncini, Elyse A; Stanzione, Joseph F

    2018-07-01

    Growing environmental and economic concerns as well as the uncertainty that accompanies finite petrochemical resources contributes to the increase in research and development of bio-based, renewable polymers. Concurrently, industrial and consumer demand for smaller, safer, and more flexible technologies motivates a global research effort to improve electrolytic polymer separators in lithium-ion batteries. To incorporate the aromatic structural advantages of lignin, a highly abundant and renewable resource, into gel-polymer electrolytes, lignin-derived molecules, vanillyl alcohol and gastrodigenin are functionalized and UV-polymerized with multi-functional thiol monomers. The resulting thin, flexible, polymer films possess glass transition temperatures ranging from -42.1°C to 0.3°C and storage moduli at 25°C ranging from 1.90MPa to 10.08MPa. The crosslinked polymer films swollen with electrolyte solution impart conductivities in the range of 7.04×10 -7 to 102.73×10 -7 Scm -1 . Thiol molecular weight has the most impact on the thermo-mechanical properties of the resulting films while polymer crosslink density has the largest effect on conductivity. The conducting abilities of the bio-based gel-polymer electrolytes in this study prove the viability of lignin-derived feedstock for use in lithium-ion battery applications and reveal structurally and thermally desirable traits for future work. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. A new polymer electrolyte based on a discotic liquid crystal triblock copolymer

    International Nuclear Information System (INIS)

    Stoeva, Zlatka; Lu, Zhibao; Ingram, Malcolm D.; Imrie, Corrie T.

    2013-01-01

    A discotic liquid crystal triblock copolymer consisting of a central main chain triphenylene-based liquid crystal block capped at both ends by blocks of poly(ethylene oxide) (PEO) (M W = 2000 g mol −1 ) has been doped with lithium perchlorate in an EO:Li 6:1 ratio. The polymer electrolyte exhibits a phase separated morphology consisting of a columnar hexagonal liquid crystal phase and PEO-rich regions. The polymer electrolyte forms self-supporting, solid-like films. The ionic conductivity on initial heating of the sample is very low below ca. 60 °C but increases rapidly above this temperature. This is attributed to the melting of crystalline PEO-rich regions. Crystallisation is suppressed on cooling, and subsequent heating cycles exhibit higher conductivities but still less than those measured for the corresponding lithium perchlorate complex in poly(ethylene glycol) (M W = 2000 g mol −1 ). Instead the triblock copolymer mimics the behaviour of high molecular weight poly(ethylene oxide) (M W = 300,000 g mol −1 ). This is attributed, in part, to the anchoring of the short PEG chains to the liquid crystal block which prevents their diffusion through the sample. Temperature and pressure variations in ion mobility indicate that the ion transport mechanism in the new material is closely related to that in the conventional PEO-based electrolyte, opening up the possibility of engineering enhanced conductivities in future

  4. 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.

  5. The effects of functional ionic liquid on properties of solid polymer electrolyte

    International Nuclear Information System (INIS)

    An Yongxin; Cheng Xinqun; Zuo Pengjian; Liao Lixia; Yin Geping

    2011-01-01

    Highlights: → The functional ionic liquid(IL)-polymer electrolytes were successfully prepared. → The ionic conductivity of PEO electrolytes was raised to above 10-4 S.cm-1 at room temperature by functional IL. → The cells using functional IL-PEO electrolyte show higher reversible capacity and long cycle life. - Abstract: Polyethylene oxide (PEO) based solid state electrolytes have been thought as promising electrolytes to replace the organic liquid electrolyte for lithium ion batteries. But the lower ionic conductivities at room temperature restrict their application. In this paper, functional ionic liquid and polymer mixed electrolytes are prepared from N-methyoxymethyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide (PP1.1O1TFSI) and polyethylene oxide. The PP1.1O1TFSI, a kind of room-temperature molten salt, was added to the conventional P(EO) 20 LiTFSI polymer electrolyte and resulted in a significant improvement of the ionic conductivity at room temperature. LiFePO 4 /Li and Li 4 Ti 5 O 12 /Li cells using this kind of electrolyte show high reversible capacity and stable cycle performance.

  6. Polycarbonate-based polyurethane as a polymer electrolyte matrix for all-solid-state lithium batteries

    Science.gov (United States)

    Bao, Junjie; Shi, Gaojian; Tao, Can; Wang, Chao; Zhu, Chen; Cheng, Liang; Qian, Gang; Chen, Chunhua

    2018-06-01

    Four kinds of polycarbonate-based polyurethane with 8-14 wt% hard segments content are synthesized via reactions of polycarbonatediol, hexamethylene diisocyanate and diethylene glycol. The mechanical strength of the polyurethanes increase with the increase of hard segments content. Solid polymer electrolytes composed of the polycarbonate-based polyurethanes and LiTFSI exhibits fascinating characteristics for all-solid-state lithium batteries with a high ionic conductivity of 1.12 × 10-4 S cm-1 at 80 °C, an electrochemical stability window up to 4.5 V (vs. Li+/Li), excellent mechanical strength and superior interfacial stability against lithium metal. The all-solid-state batteries using LiFePO4 cathode can deliver high discharge capacities (161, 158, 134 and 93 mAh g-1 at varied rates of 0.2, 0.5, 1 and 2 C) at 80 °C and excellent cycling performance (with 91% capacity retention after 600 cycles at 1 C). All the results indicate that such a polyurethane-based solid polymer electrolyte can be a promising candidate for all-solid-state lithium batteries.

  7. Conductivity enhancement via chemical modification of chitosan based green polymer electrolyte

    International Nuclear Information System (INIS)

    Mobarak, N.N.; Ahmad, A.; Abdullah, M.P.; Ramli, N.; Rahman, M.Y.A.

    2013-01-01

    The potential of carboxymethyl chitosan as a green polymer electrolyte has been explored. Chitosan produced from partial deacetylation of chitin was reacted with monochloroacetic acid to form carboxymethyl chitosan. A green polymer electrolyte based chitosan and carboxymethyl chitosan was prepared by solution-casting technique. The powder and films were characterized by reflection Fourier transform infrared (ATR-FTIR) spectroscopy, 1 H nuclear magnetic resonance, elemental analysis and X-ray diffraction, electrochemical impedance spectroscopy, and scanning electron microscopy. The shift of wavenumber that represents hydroxyl and amine stretching confirmed the polymer solvent complex formation. The XRD spectra results show that chemical modification of chitosan has improved amorphous properties of chitosan. The ionic conductivity was found to increase by two magnitudes higher with the chemical modification of chitosan. The highest conductivity achieved was 3.6 × 10 −6 S cm −1 for carboxymethyl chitosan at room temperature and 3.7 × 10 −4 S cm −1 at 60 °C

  8. Influence of membrane composition on its flexibility

    Energy Technology Data Exchange (ETDEWEB)

    Gerbelli, B.B.; Teixeira da Silva, E.R.; Oliveira, C.L.P.; Oliveira, E.A. [Universidade de Sao Paulo (USP), SP (Brazil)

    2012-07-01

    Full text: Lamellar phases and vesicles composed of lipids have been used as model systems to investigate biological process related to cell membrane as well as promising carriers for drugs and gene therapy. The composition of the membrane determines its three dimensional shape and its properties such as rigidity and compressibility which play an important role on membrane fusion, protein adhesion, interactions between proteins, etc. We present systematic study of a lamellar system composed mainly of lecithin which is a biocompatible phospholipid and simusol, which is a mixture of fatty acids that acts as a cosurfactant introducing flexibility to the membrane. Using X ray scattering we determine the lamellar periodicity as a function of the hydration for different formulations of the membrane; ranging from 100 % to 50 % mass fraction of lecithin. The X-ray spectra are fitted using a 4 Gaussian model [1]that allows us to determine the lamellar periodicity and the Caille parameter [2]. The ideal swelling law relating the membrane volume fraction ({phi}{sub m}) to the lamellar periodicity (D) is given by {phi}{sub m} ={delta}{sub m}/D, where {delta}{sub m} is the thickness membrane, however, when steric interactions are dominant with respect to electrostatic and van der Waals interactions, deviations from this behavior are expected [3]. We present experimental data illustrating the swelling behavior for the membrane compositions and the respective behavior of the hydration limit, membrane Luzzati [4], of the Caille parameter and qualitative interpretation of the interaction forces the systems studying the parameter membrane square amplitude fluctuation[5]. [1] Private communication with Prof. Dr. Cristiano Luis Pinto de Oliveira. [2] Caille A. et all, Acad. Sci. Paris B274 (1972) 891. [3] E. Kurtisovski et all, PRL 98, 258103 (2007). [4] Nagle et all, Curr Opin Struct Biol. 2000 Aug;10(4):474-80. [5] H. I. Petrache. Structure and interactions of fluid phospholipids

  9. Cycling Performance of Li4Ti5O12 Electrodes in Ionic Liquid-Based Gel Polymer Electrolytes

    International Nuclear Information System (INIS)

    Kim, Jin Hee; Kim, Dong Won; Kang, Yong Ku

    2012-01-01

    We investigated the cycling behavior of Li 4 Ti 5 O 12 electrode in a cross-linked gel polymer electrolyte based on non-flammable ionic liquid consisting of 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide and vinylene carbonate. The Li 4 Ti 5 O 12 electrodes in ionic liquid-based gel polymer electrolytes exhibited reversible cycling behavior with good capacity retention. Cycling data and electrochemical impedance spectroscopy analyses revealed that the optimum content of the cross-linking agent necessary to ensure both acceptable initial discharge capacity and good capacity retention was about 8 wt %

  10. The platinum catalyst layer in polymer-electrolyte fuel cells[Dissertation 17127]; Die Platinkatalysatorschicht in Polymerelektrolyt-Brennstoffzellen. Beitraege zum Verstaendnis und zur Optimierung

    Energy Technology Data Exchange (ETDEWEB)

    Reiner, A.

    2007-07-01

    This illustrated, comprehensive dissertation by Dr. Andreas Reiner presents an in-depth analysis of polymer electrolyte fuel cells (PEFC) and in particular, their platinum catalyst layer. First of all, the thermodynamics and kinetics involved are reviewed, along with components, their efficiencies and the catalyst layer. The methods used, including scanning electron microscope, x-ray and Rutherford spectroscopy are discussed. The structure and composition of co-sputtered catalyst layers and their production are described. Electro-chemical activation and the electro-chemical properties of the layers are discussed. The second part of the dissertation deals with the principle of hydrogen under-potential deposition. This method provides information about the electrochemically active platinum surface fraction. The results of investigations made are presented and discussed.

  11. Organic-inorganic hybrid polymer electrolytes based on polyether diamine, alkoxysilane, and trichlorotriazine: Synthesis, characterization, and electrochemical applications

    Science.gov (United States)

    Saikia, Diganta; Wu, Cheng-Gang; Fang, Jason; Tsai, Li-Duan; Kao, Hsien-Ming

    2014-12-01

    A new type of highly conductive organic-inorganic hybrid polymer electrolytes has been synthesized by the reaction of poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether), 2,4,6-trichloro-1,3,5-triazine and alkoxysilane precursor 3-(glycidyloxypropyl)trimethoxysilane, followed by doping of LiClO4. The 13C and 29Si solid-sate NMR results confirm the successful synthesis of the organic-inorganic hybrid structure. The solid hybrid electrolyte thus obtained exhibits a maximum ionic conductivity of 1.6 × 10-4 S cm-1 at 30 °C, which is the highest among the organic-inorganic hybrid electrolytes. The hybrid electrolytes are electrochemically stable up to 4.2 V. The prototype electrochromic device with such a solid hybrid electrolyte demonstrates a good coloration efficiency value of 183 cm2 C-1 with a cycle life over 200 cycles. For the lithium-ion battery test, the salt free solid hybrid membrane is swelled with a LiPF6-containing electrolyte solution to reach an acceptable ionic conductivity value of 6.5 × 10-3 S cm-1 at 30 °C. The battery cell carries an initial discharge capacity of 100 mAh g-1 at 0.2C-rate and a coulombic efficiency of about 95% up to 30 cycles without the sign of cell failure. The present organic-inorganic hybrid electrolytes hold promise for applications in electrochromic devices and lithium ion batteries.

  12. Mass and charge transfer on various relevant scales in polymer electrolyte fuel cells[Dissertation 16991

    Energy Technology Data Exchange (ETDEWEB)

    Freunberger, S. A.

    2007-07-01

    This dissertation is concerned with the development, experimental diagnostics and mathematical modelling and simulation of polymer electrolyte fuel cells (PEFC). The central themes throughout this thesis are the closely interlinked phenomena of mass and charge transfer. In the face of developing a PEFC system for vehicle propulsion these phenomena are scrutinized on a broad range of relevant scales. Starting from the material related level of the membrane and the gas diffusion layer (GDL) we turn to length scales, where structural features of the cell additionally come into play. These are the scale of flow channels and ribs, the single cell and the cell stack followed by the cell, stack, and system development for an automotive power train. In Chapter 3 selected fundamental material models and properties, respectively, are explored that are crucial for the mathematical modelling and simulation of PEFC, as needed in some succeeding parts of this work. First, established mathematical models for mass and charge transfer in the membrane are compared within the framework of the membrane electrode assembly (MEA), which represents the electrochemical unit. Second, reliable values for effective diffusivities in the GDLs which are vital for the simulation of gaseous mass transport are measured. Therefore, a method is developed that allows measuring this quantity both as a function of compression and direction as this is a prerequisite of sophisticated more-dimensional numerical PEFC-models. Besides the cross section of the catalyst layer (CL) mass transfer under channels and ribs is considered as a major source of losses in particular under high load operation. As up to now there have been solely non-validated theoretical investigations, in Chapter 4 an experimental method is developed that is for the first time capable of resolving the current density distribution on the this scale. For this, the electron conductors in the cell are considered as 2-dimensional shunt

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

    KAUST Repository

    Seo, Jeongsuk; Zhao, Lan; Cha, Dong Kyu; Takanabe, Kazuhiro; Katayama, Masao; Kubota, Jun; Domen, Kazunari

    2013-01-01

    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

  14. Facile and Reliable in Situ Polymerization of Poly(Ethyl Cyanoacrylate)-Based Polymer Electrolytes toward Flexible Lithium Batteries.

    Science.gov (United States)

    Cui, Yanyan; Chai, Jingchao; Du, Huiping; Duan, Yulong; Xie, Guangwen; Liu, Zhihong; Cui, Guanglei

    2017-03-15

    Polycyanoacrylate is a very promising matrix for polymer electrolyte, which possesses advantages of strong binding and high electrochemical stability owing to the functional nitrile groups. Herein, a facile and reliable in situ polymerization strategy of poly(ethyl cyanoacrylate) (PECA) based gel polymer electrolytes (GPE) via a high efficient anionic polymerization was introduced consisting of PECA and 4 M LiClO 4 in carbonate solvents. The in situ polymerized PECA gel polymer electrolyte achieved an excellent ionic conductivity (2.7 × 10 -3 S cm -1 ) at room temperature, and exhibited a considerable electrochemical stability window up to 4.8 V vs Li/Li + . The LiFePO 4 /PECA-GPE/Li and LiNi 1.5 Mn 0.5 O 4 /PECA-GPE/Li batteries using this in-situ-polymerized GPE delivered stable charge/discharge profiles, considerable rate capability, and excellent cycling performance. These results demonstrated this reliable in situ polymerization process is a very promising strategy to prepare high performance polymer electrolytes for flexible thin-film batteries, micropower lithium batteries, and deformable lithium batteries for special purpose.

  15. Poly(vinylpyridine-co-styrene) based in situ cross-linked gel polymer electrolyte for lithium-ion polymer batteries

    International Nuclear Information System (INIS)

    Oh, Sijin; Kim, Dong Wook; Lee, Changjin; Lee, Myong-Hoon; Kang, Yongku

    2011-01-01

    A gel polymer electrolyte (GPE) was successfully prepared by means of an in situ cross-linking reaction of poly(2-vinylpyridine-co-styrene) and oligo(ethylene oxide) with epoxide functional groups at 65 °C without using a polymerization initiator. A stable gel polymer electrolyte could be obtained by adding only 1% of a polymer gelator. The ionic conductivity of the GPE containing 99 wt% of liquid electrolyte was measured to be ca. 10 −2 S/cm at the ambient temperature. The ionic conductivity of the resulting GPE was comparable to that of a pure liquid electrolyte. The electrochemical stability window of the prepared gel polymer electrolytes was measured to be 5.2 V. The test cell carried a discharge capacity of 133.2 mAh/g at 0.1 C and showed good cycling performance with negligible capacity fading after the 200th cycle, maintaining 99.5% coulombic efficiency throughout 200 cycles. The resulting gel polymer electrolyte prepared by in situ thermal cross-linking without a polymerization initiator holds promise for application to on the high power lithium-ion polymer batteries.

  16. Conductivity through Polymer Electrolytes and Its Implications in Lithium-Ion Batteries: Real-World Application of Periodic Trends

    Science.gov (United States)

    Compton, Owen C.; Egan, Martin; Kanakaraj, Rupa; Higgins, Thomas B.; Nguyen, SonBinh T.

    2012-01-01

    Periodic conductivity trends are placed in the scope of lithium-ion batteries, where increases in the ionic radii of salt components affect the conductivity of a poly(ethyleneoxide)-based polymer electrolyte. Numerous electrolytes containing varying concentrations and types of metal salts are prepared and evaluated in either one or two laboratory…

  17. Solid polymer electrolyte water electrolysis system development. [to generate oxygen for manned space station applications

    Science.gov (United States)

    1975-01-01

    Solid polymer electrolyte technology used in a water electrolysis system (WES) to generate oxygen and hydrogen for manned space station applications was investigated. A four-man rated, low pressure breadboard water electrolysis system with the necessary instrumentation and controls was fabricated and tested. A six man rated, high pressure, high temperature, advanced preprototype WES was developed. This configuration included the design and development of an advanced water electrolysis module, capable of operation at 400 psig and 200 F, and a dynamic phase separator/pump in place of a passive phase separator design. Evaluation of this system demonstrated the goal of safe, unattended automated operation at high pressure and high temperature with an accumulated gas generation time of over 1000 hours.

  18. Development status of solid polymer electrolyte water electrolysis for manned spacecraft life support systems

    Science.gov (United States)

    Nuttall, L. J.; Titterington, W. A.

    1974-01-01

    Details of the design and system verification test results are presented for a six-man-rated oxygen generation system. The system configuration incorporates components and instrumentation for computer-controlled operation with automatic start-up/shutdown sequencing, fault detection and isolation, and with self-contained sensors and controls for automatic safe emergency shutdown. All fluid and electrical components, sensors, and electronic controls are designed to be easily maintainable under zero-gravity conditions. On-board component spares are utilized in the system concept to sustain long-term operation (six months minimum) in a manned spacecraft application. The system is centered on a 27-cell solid polymer electrolyte water electrolysis module which, combined with the associated system components and controls, forms a total system envelope 40 in. high, 40 in. wide, and 30 in. deep.

  19. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Adam, Nurul Ilham [Faculty of Applied Sciences, Universiti Teknologi MARA, KampusTapah, 35400 Tapah Road, Tapah, Perak (Malaysia); Yahya, Muhd Zu Azhan [Faculty of Defence Sciences and Technology, Universiti Pertahanan Nasional Malaysia, Kem Sungai Besi, 57000 Kuala Lumpur (Malaysia); Ali, Ab Malik Marwan [Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2015-08-28

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance ({sup 1}HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in {sup 1}HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF{sub 3}SO{sub 3} show the highest conductivity. The complexation between EMG30 and LiCF{sub 3}SO{sub 3} were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR)

  20. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    International Nuclear Information System (INIS)

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz; Adam, Nurul Ilham; Yahya, Muhd Zu Azhan; Ali, Ab Malik Marwan

    2015-01-01

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance ( 1 HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in 1 HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF 3 SO 3 show the highest conductivity. The complexation between EMG30 and LiCF 3 SO 3 were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR)

  1. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    Science.gov (United States)

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz; Adam, Nurul Ilham; Yahya, Muhd Zu Azhan; Ali, Ab Malik Marwan

    2015-08-01

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance (1HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in 1HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF3SO3 show the highest conductivity. The complexation between EMG30 and LiCF3SO3 were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR).

  2. Morphology, optical and ionic conductivity studies of electron beam irradiated polymer electrolyte film

    Science.gov (United States)

    Devendrappa, H.; Yesappa, L.; Niranjana, M.; Ashokkumar, S. P.; Vijeth, H.; Ganesh, S.

    2018-04-01

    The effects of electron beam (EB) irradiation on morphology, optical properties and ionic conductivity of (PVdF-co-HFP: LiClO4=90:10, PHL10) electrolyte films. The FESEM image reveal increasing porous morphology with increasing EB dose confirms the polymer degradation as result more amorphousity. The optical absorbance was found to be increase with red shift in UV region and direct optical band gaps was found decreased upon EB dose from 3.70 eV to 2.65 eV. The ionic conductivity increases slowly in lower frequency, whereas rapidly increases at the high frequency and found about 8.28×10-4 S/cm at 120 kGy dose. The obtained results suggest that the physical properties of polymer electrolytes can be changed using EB irradiation as requirement.

  3. Neutron Computed Tomography of Freeze/thaw Phenomena in Polymer Electrolyte Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Matthew M. Mech; Jack Brenizer; Kenan Unlu; A.K. Heller

    2008-12-12

    This report summarizes the final year's progress of the three-year NEER program. The overall objectives of this program were to 1) design and construct a sophisticated hight-resolution neutron computed tomography (NCT) facility, 2) develop novel and sophisticated liquid water and ice quantification analysis software for computed tomography, and 3) apply the advanced software and NCT capability to study liquid and ice distribution in polymer electrolyte fuel cells (PEFCs) under cold-start conditions. These objectives have been accomplished by the research team, enabling a new capability for advanced 3D image quantification with neutron imaging for fuel cell and other applications. The NCT water quantification methodology and software will greatly add to the capabilities of the neutron imaging community, and the quantified liquid water and ice distribution provided by its application to PEFCs will enhance understanding and guide design in the fuel cell community.

  4. Ionic Liquid-Doped Gel Polymer Electrolyte for Flexible Lithium-Ion Polymer Batteries

    Science.gov (United States)

    Zhang, Ruisi; Chen, Yuanfen; Montazami, Reza

    2015-01-01

    Application of gel polymer electrolytes (GPE) in lithium-ion polymer batteries can address many shortcomings associated with liquid electrolyte lithium-ion batteries. Due to their physical structure, GPEs exhibit lower ion conductivity compared to their liquid counterparts. In this work, we have investigated and report improved ion conductivity in GPEs doped with ionic liquid. Samples containing ionic liquid at a variety of volume percentages (vol %) were characterized for their electrochemical and ionic properties. It is concluded that excess ionic liquid can damage internal structure of the batteries and result in unwanted electrochemical reactions; however, samples containing 40–50 vol % ionic liquid exhibit superior ionic properties and lower internal resistance compared to those containing less or more ionic liquids.

  5. Miniaturized polymer electrolyte fuel cell (PEFC) stack using micro structured bipolar plate

    Energy Technology Data Exchange (ETDEWEB)

    Veziridis, Z; Scherer, G G; Marmy, Ch; Glaus, F [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    In Polymer Electrolyte Fuel Cell (PEFC) technology the reducing of volume and mass of the fuel cell stack and the improvement of catalyst utilization are of great interest. These parameters affect applicability and system cost. In this work we present an alternative way for reducing the stack volume by combining gas distribution and catalytic active area in one plate. Micro machined glassy carbon electrodes serve as support material for the platinum catalyst, as well as gas distributor at the same time. A comparison of these electrodes with conventional platinum-black gas diffusion electrodes under fuel cell conditions shows that the new system is a promising electrode type for enhanced power density and catalyst utilization. (author) 3 figs., 5 refs.

  6. Tantalum oxide-based compounds as new non-noble cathodes for polymer electrolyte fuel cell

    International Nuclear Information System (INIS)

    Ishihara, Akimitsu; Tamura, Motoko; Matsuzawa, Koichi; Mitsushima, Shigenori; Ota, Ken-ichiro

    2010-01-01

    Tantalum oxide-based compounds were examined as new non-noble cathodes for polymer electrolyte fuel cell. Tantalum carbonitride powder was partially oxidized under a trace amount of oxygen gas at 900 o C for 4 or 8 h. Onset potential for oxygen reduction reaction (ORR) of the specimen heat-treated for 8 h was 0.94 V vs. reversible hydrogen electrode in 0.1 mol dm -3 sulfuric acid at 30 o C. The partial oxidation of tantalum carboniride was effective to enhance the catalytic activity for the ORR. The partially oxidized specimen with highest catalytic activity had ca. 5.25 eV of ionization potential, indicating that there was most suitable strength of the interaction of oxygen and tantalum on the catalyst surface.

  7. Effect of Dimethyl Carbonate Plasticizer on Ionic Conductivity of Methyl Cellulose-Based Polymer Electrolytes

    International Nuclear Information System (INIS)

    Mustafa, M.F.; Ridwan, N.I.M.; Hatta, F.F.; Yahya, M.Z.A.

    2012-01-01

    Influences of dimethyl carbonate (DMC) plasticizer on ionic conductivity, dielectric permittivity and electrical modulus formalism of methyl cellulose (MC)-based polymer electrolytes have been studied. The room temperature electrical conductivity as measured by impedance spectroscopy shows that a methyl cellulose film has a conductivity of ∼10 -10 S cm -1 . In this study, other than KOH ionic dopant, DMC plasticizer is also added to the polymer with the aim of enhancing the electrical conductivity of the polymer. The highest room temperature conductivity of the plasticised sample is ∼10 -5 S cm -1 . The plot of log σ versus 10 3 / T for the highest conducting sample obeys Arrhenius rule indicating that the conductivity occurs by thermally activated mechanism. (author)

  8. Evaluation of solid polymer electrolytes for use in conducting polymer/nanotube actuators

    Science.gov (United States)

    Lewis, Trevor W.; Kim, B. C.; Spinks, Geoffrey M.; Wallace, Gordon G.

    2000-06-01

    The stringent requirements for a solid polymer electrolyte (SPE) in solid state devices such as batteries or supercapacitors are even more demanding when used in electromechanical actuators. Not only is the SPE expected to exhibit good conductivity, mechanical properties, adhesion and mechanical/electrical stability, but it must also be flexible, maintained good adhesion while flexing, be easily processible and be able to function in air. In this work polyacrylonitrile and Kynar based non-aqueous SPEs and water based polyacrylamide hydrogel ion source/sinks containing various perchlorate salts were tested for their applicability to polypyrrole and carbon nanotube actuators and supercapacitors. The results indicate that the optimum SPE for both polypyrrole and carbon nanotube actuators would be a polyacrylonitrile plasticized with propylene carbonate and ethylene carbonate containing 1.0M NaClO4. It is also apparent that the same SPE would be the most suitable for supercapacitor applications with these materials.

  9. Electrochemical performance of trimethylolpropane trimethylacrylate-based gel polymer electrolyte prepared by in situ thermal polymerization

    International Nuclear Information System (INIS)

    Zhou, Dong; Fan, Li-Zhen; Fan, Huanhuan; Shi, Qiao

    2013-01-01

    Cross-linked trimethylolpropane trimethylacrylate-based gel polymer electrolytes (GPE) were prepared by in situ thermal polymerization. The ionic conductivity of the GPEs are >10 −3 S cm −1 at 25 °C, and continuously increased with the increase of liquid electrolyte content. The GPEs have excellent electrochemical stability up to 5.0 V versus Li/Li + . The LiCoO 2 |TMPTMA-based GPE|graphite cells exhibit an initial discharge capacity of 129 mAh g −1 at the 0.2C, and good cycling stability with around 83% capacity retention after 100 cycles. Both the simple fabricating process of polymer cell and outstanding electrochemical performance of such new GPE make it potentially one of the most promising electrolyte materials for next generation lithium ion batteries

  10. Ionic Liquid-Doped Gel Polymer Electrolyte for Flexible Lithium-Ion Polymer Batteries

    Directory of Open Access Journals (Sweden)

    Ruisi Zhang

    2015-05-01

    Full Text Available Application of gel polymer electrolytes (GPE in lithium-ion polymer batteries can address many shortcomings associated with liquid electrolyte lithium-ion batteries. Due to their physical structure, GPEs exhibit lower ion conductivity compared to their liquid counterparts. In this work, we have investigated and report improved ion conductivity in GPEs doped with ionic liquid. Samples containing ionic liquid at a variety of volume percentages (vol % were characterized for their electrochemical and ionic properties. It is concluded that excess ionic liquid can damage internal structure of the batteries and result in unwanted electrochemical reactions; however, samples containing 40–50 vol % ionic liquid exhibit superior ionic properties and lower internal resistance compared to those containing less or more ionic liquids.

  11. Dye-sensitized solar cells and solar module using polymer electrolytes: Stability and performance investigations

    Directory of Open Access Journals (Sweden)

    Jilian Nei de Freitas

    2006-01-01

    Full Text Available We present recent results on solid-state dye-sensitized solar cell research using a polymer electrolyte based on a poly(ethylene oxide derivative. The stability and performance of the devices have been improved by a modification in the method of assembly of the cells and by the addition of plasticizers in the electrolyte. After 30 days of solar irradiation (100 mW cm-2 no changes in the cell's efficiency were observed using this new method. The effect of the active area size on cell performance and the first results obtained for the first solar module composed of 4.5 cm2 solid-state solar cells are also presented.

  12. Investigating the dynamics of a direct parallel combination of supercapacitors and polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Papra, M.; Buechi, F.N.; Koetz, R. [Electrochemistry Laboratory, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland)

    2010-10-15

    Hydrogen fuelled vehicles with a fuel cell based powertrain are considered to contribute to sustainable mobility by reducing CO{sub 2} emissions from road transport. In such vehicles the fuel cell system is typically hybridised with an energy storage device such as a battery or a supercapacitor (SC) to allow for recovering braking energy and assist the fuel cell system for peak power. The direct parallel combination of a polymer electrolyte fuel cell (PEFC) and a SC without any control electronics is investigated in the present study. It is demonstrated that the combination enhances the dynamics of the PEFC significantly during load changes. However, due to the lack of a power electronic interface the SC cannot be utilised to its optimum capacity. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  13. 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.

  14. High elastic modulus polymer electrolytes suitable for preventing thermal runaway in lithium batteries

    Science.gov (United States)

    Mullin, Scott; Panday, Ashoutosh; Balsara, Nitash Pervez; Singh, Mohit; Eitouni, Hany Basam; Gomez, Enrique Daniel

    2014-04-22

    A polymer that combines high ionic conductivity with the structural properties required for Li electrode stability is useful as a solid phase electrolyte for high energy density, high cycle life batteries that do not suffer from failures due to side reactions and dendrite growth on the Li electrodes, and other potential applications. The polymer electrolyte includes a linear block copolymer having a conductive linear polymer block with a molecular weight of at least 5000 Daltons, a structural linear polymer block with an elastic modulus in excess of 1.times.10.sup.7 Pa and an ionic conductivity of at least 1.times.10.sup.-5 Scm.sup.-1. The electrolyte is made under dry conditions to achieve the noted characteristics. In another aspect, the electrolyte exhibits a conductivity drop when the temperature of electrolyte increases over a threshold temperature, thereby providing a shutoff mechanism for preventing thermal runaway in lithium battery cells.

  15. Studies on AC Electrical Conductivity of CdCl2 Doped PVA Polymer Electrolyte

    Directory of Open Access Journals (Sweden)

    M. B. Nanda Prakash

    2013-01-01

    Full Text Available PVA-based polymer electrolytes were prepared with various concentrations of CdCl2 using solvent casting method. Prepared polymer films were investigated using line profile analysis employing X-ray diffraction (XRD data. XRD results show that the crystallite size decreases and then increases with increase in CdCl2. AC conductivity in these polymer increases films first and then decreases. These observations are in agreement with XRD results. The highest ionic conductivity of 1.68E − 08 Scm−1 was observed in 4% of CdCl2 in PVA polymer blend. Crystallite ellipsoids for different concentrations of CdCl2 are computed here using whole pattern powder fitting (WPPF indicating that crystallite area decreases with increase in the ionic conductivity.

  16. Cogeneration of electricity and organic chemicals using a polymer electrolyte fuel cell

    International Nuclear Information System (INIS)

    Yuan, X.; Ma, Z.; Bueb, H.; Drillet, J.-F.; Hagen, J.; Schmidt, V.M.

    2005-01-01

    Several unsaturated organic alcohols (allyl alcohol, propargyl alcohol, 2-butin-1,4-diol, 2- buten-1,4-diol) and acids (maleic acid, acrylic acid, crotonic acid, acetylendicarboxylic acid) were used as oxidants together with hydrogen as fuel in a polymer electrolyte fuel cell (PEFC). The standard free enthalpies (Δ R G θ ) of the overall fuel cell reactions H 2 /oxidant were calculated to be negative and the equilibrium voltages of such systems are in the range of U 00 = 0.4-0.6 V. In this way, the cogeneration of electric energy and desired hydrogenated products in a fuel cell reactor is apparent. Nafion[reg] 117, as polymer electrolyte, and commercial gas diffusion electrodes (ETEK) with carbon supported Pt were used in a PEFC reactor. The aqueous solutions of unsaturated alcohols and organic acids (c = 1-2 mol dm -3 ) were pumped under ambient pressure through the cathode compartment of the cell whereas hydrogen was fed into the cell at p 0.15 MPa. The open circuit voltages were measured to be in the range of 0.1-0.25 V. Current densities up to 50 mA cm -2 and maximum power densities of around 1 mW cm -2 has been achieved in the case of allyl alcohol, 2-butene-1,4-diol and acrylic acid. HPLC analysis indicates that the double or triple bond in unsaturated alcohols and organic acids is selectively hydrogenated. In addition, the electrochemical behaviour of the alcohols and acids was studied by means of cyclic voltammetry at a smooth polycrystalline Pt electrode in H 2 SO 4 . Reduction reactions were observed at potentials of E < 200 mV versus RHE. It was found that the onset potential for electrochemical hydrogenation of the double and triple bond in the cyclic voltamogram correlates well with the fuel cell performances using these compounds as oxidants

  17. Tubular array, dielectric, conductivity and electrochemical properties of biodegradable gel polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Sudhakar, Y.N. [Department of Chemistry, Manipal Institute of Technology, Manipal, Karnataka (India); Selvakumar, M., E-mail: chemselva78@gmail.com [Department of Chemistry, Manipal Institute of Technology, Manipal, Karnataka (India); Bhat, D. Krishna [Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Mangalore (India)

    2014-02-15

    Highlights: • A new finding of tubular array of 10–20 μm in length and 1–2 μm in thickness of gel polymer electrolyte (GPE) having 2.2 × 10{sup −3} S cm{sup −1} conductivity is reported. • Thermal and electrochemical characterizations of GPEs show good interaction among the polymer, plasticizer and salt. • GPE based supercapacitor demonstrates high capacitance of 186 F g{sup −1}. • Low temperature studies did not influence much on capacitance values obtained from AC impedance studies. • Charge–discharge exhibits high capacity with excellent cyclic stability and energy density. -- Abstract: A supercapacitor based on a biodegradable gel polymer electrolyte (GPE) has been fabricated using guar gum (GG) as the polymer matrix, LiClO{sub 4} as the doping salt and glycerol as the plasticizer. The scanning electron microscopy (SEM) images of the gel polymer showed an unusual tubular array type surface morphology. FTIR, DSC and TGA results of the GPE indicated good interaction between the components used. Highest ionic conductivity and lowest activation energy values were 2.2 × 10{sup −3} S cm{sup −1} and 0.18 eV, respectively. Dielectric studies revealed ionic behavior and good capacitance with varying frequency of the GPE system. The fabricated supercapacitor showed a maximum specific capacitance value of 186 F g{sup −1} using cyclic voltammetry. Variation of temperature from 273 K to 293 K did not significantly influence the capacitance values obtained from AC impedance studies. Galvanostatic charge–discharge study of supercapacitor indicated that the device has good stability, high energy density and power density.

  18. Performance of solid state supercapacitors based on polymer electrolytes containing different ionic liquids

    Science.gov (United States)

    Tiruye, Girum Ayalneh; Muñoz-Torrero, David; Palma, Jesus; Anderson, Marc; Marcilla, Rebeca

    2016-09-01

    Four Ionic Liquid based Polymer Electrolytes (IL-b-PE) were prepared by blending a Polymeric Ionic Liquid, Poly(diallyldimethylammonium) bis(trifluoromethanesulfonyl)imide (PILTFSI), with four different ionic liquids: 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI) (IL-b-PE1), 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (PYR14FSI) (IL-b-PE2), 1-(2-hydroxy ethyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (HEMimTFSI) (IL-b-PE3), and 1-Butyl-1-methylpyrrolidinium dicyanamide, (PYR14DCA) (IL-b-PE4). Physicochemical properties of IL-b-PE such as ionic conductivity, thermal and electrochemical stability were found to be dependent on the IL properties. For instance, ionic conductivity was significantly higher for IL-b-PE2 and IL-b-PE4 containing IL with small size anions (FSI and DCA) than IL-b-PE1 and IL-b-PE3 bearing IL with bigger anion (TFSI). On the other hand, wider electrochemical stability window (ESW) was found for IL-b-PE1 and IL-b-PE2 having ILs with electrochemically stable pyrrolidinium cation and FSI and TFSI anions. Solid state Supercapacitors (SCs) were assembled with activated carbon electrodes and their electrochemical performance was correlated with the polymer electrolyte properties. Best performance was obtained with SC having IL-b-PE2 that exhibited a good compromise between ionic conductivity and electrochemical window. Specific capacitance (Cam), real energy (Ereal) & real power densities (Preal) as high as 150 F g-1, 36 Wh kg-1 & 1170 W kg-1 were found at operating voltage of 3.5 V.

  19. Towards Highly Performing and Stable PtNi Catalysts in Polymer Electrolyte Fuel Cells for Automotive Application

    Directory of Open Access Journals (Sweden)

    Sabrina C. Zignani

    2017-03-01

    Full Text Available In order to help the introduction on the automotive market of polymer electrolyte fuel cells (PEFCs, it is mandatory to develop highly performing and stable catalysts. The main objective of this work is to investigate PtNi/C catalysts in a PEFC under low relative humidity and pressure conditions, more representative of automotive applications. Carbon supported PtNi nanoparticles were prepared by reduction of metal precursors with formic acid and successive thermal and leaching treatments. The effect of the chemical composition, structure and surface characteristics of the synthesized samples on their electrochemical behavior was investigated. The catalyst characterized by a larger Pt content (Pt3Ni2/C presented the highest catalytic activity (lower potential losses in the activation region among the synthesized bimetallic PtNi catalysts and the commercial Pt/C, used as the reference material, after testing at high temperature (95 °C and low humidification (50% conditions for automotive applications, showing a cell potential (ohmic drop-free of 0.82 V at 500 mA·cm−2. In order to assess the electro-catalysts stability, accelerated degradation tests were carried out by cycling the cell potential between 0.6 V and 1.2 V. By comparing the electrochemical and physico-chemical parameters at the beginning of life (BoL and end of life (EoL, it was demonstrated that the Pt1Ni1/C catalyst was the most stable among the catalyst series, with only a 2% loss of voltage at 200 mA·cm−2 and 12.5% at 950 mA·cm−2. However, further improvements are needed to produce durable catalysts.

  20. Design of a Composite Membrane with Patches

    International Nuclear Information System (INIS)

    Cuccu, Fabrizio; Emamizadeh, Behrouz; Porru, Giovanni

    2010-01-01

    This paper is concerned with minimization and maximization problems of eigenvalues. The principal eigenvalue of a differential operator is minimized or maximized over a set which is formed by intersecting a rearrangement class with an affine subspace of finite co-dimension. A solution represents an optimal design of a 2-dimensional composite membrane Ω, fixed at the boundary, built out of two different materials, where certain prescribed regions (patches) in Ω are occupied by both materials. We prove existence results, and present some features of optimal solutions. The special case of one patch is treated in detail.

  1. Ionic conductivity and electrochemical properties of nanocomposite polymer electrolytes based on electrospun poly(vinylidene fluoride-co-hexafluoropropylene) with nano-sized ceramic fillers

    Energy Technology Data Exchange (ETDEWEB)

    Raghavan, Prasanth; Zhao Xiaohui; Kim, Jae-Kwang; Manuel, James; Chauhan, Ghanshyam S. [Department of Chemical and Biological Engineering and Engineering Research Institute, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of); Ahn, Jou-Hyeon [Department of Chemical and Biological Engineering and Engineering Research Institute, Gyeongsang National University, 900 Gajwa-dong, Jinju 660-701 (Korea, Republic of)], E-mail: jhahn@gnu.ac.kr; Nah, Changwoon [Department of Polymer-Nano Science and Technology, Chonbuk National University, 664-14 Duckjin-dong, Jeonju 561-756 (Korea, Republic of)

    2008-12-30

    A series of nanocomposite polymer electrolytes (NCPEs) comprising nanoparticles of BaTiO{sub 3}, Al{sub 2}O{sub 3} or SiO{sub 2} were prepared by electrospinning technique. The nano-sized ceramic fillers were incorporated into poly(vinylidene fluoride-co-hexafluoropropylene) [P(VdF-HEP)] membranes during the electrospinning process. The resultant porous membranes are good absorbent of the liquid electrolyte and exhibit high electrolyte retention capacity. The presence of the ceramic nanoparticles has positive effect on the mechanical properties of the membranes. The ionic conductivity and the electrochemical stability window of the electrospun P(VdF-HFP)-based polymer are enhanced by the presence of the fillers. The cell Li/LiFePO{sub 4} based on the NCPE containing BaTiO{sub 3} delivers a discharge capacity of 164 mAh/g, which corresponds to 96.5% utilization of the active material. In comparison, the performance of Li/LiFePO{sub 4} cells with NCPEs containing Al{sub 2}O{sub 3} and SiO{sub 2} was observed to be lower with respective discharge capacities of 153 and 156 mAh/g. The enhanced performance of the BaTiO{sub 3}-based-NCPE is attributed mainly to its better interaction with the host polymer and compatibility with lithium metal.

  2. Thin porphyrin composite membranes with enhanced organic solvent transport

    KAUST Repository

    Phuoc, Duong; Anjum, Dalaver H.; Peinemann, Klaus-Viktor; Nunes, Suzana Pereira

    2018-01-01

    Extending the stability of polymeric membranes in organic solvents is important for applications in chemical and pharmaceutical industry. Thin-film composite membranes with enhanced solvent permeance are proposed, using porphyrin as a building block

  3. Sulfonated carbon black-based composite membranes for fuel cell ...

    Indian Academy of Sciences (India)

    the properties of the composite membranes with the addition of S–C particles at high concentrations due to the .... metry and nuclear magnetic resonance that assured no sol- ... BT-512 BekkTech membrane test system at varying relative.

  4. High Performance Thin-Film Composite Forward Osmosis Membrane

    KAUST Repository

    Yip, Ngai Yin; Tiraferri, Alberto; Phillip, William A.; Schiffman, Jessica D.; Elimelech, Menachem

    2010-01-01

    obstacle hindering further advancements of this technology. This work presents the development of a high performance thin-film composite membrane for forward osmosis applications. The membrane consists of a selective polyamide active layer formed

  5. Tantalum carbide as a novel support material for anode electrocatalysts in polymer electrolyte membrane water electrolysers

    DEFF Research Database (Denmark)

    Polonský, Jakub; Petrushina, Irina; Christensen, Erik

    2012-01-01

    Iridium oxide (IrO2) currently represents a state of the art electrocatalyst for anodic oxygen evolution. Since iridium is both expensive and scarce, the future practical application of this process makes it essential to reduce IrO2 loading on the anodes of PEM water electrolysers. In the present...

  6. Nonlinear modelling of polymer electrolyte membrane fuel cell stack using nonlinear cancellation technique

    Energy Technology Data Exchange (ETDEWEB)

    Barus, R. P. P., E-mail: rismawan.ppb@gmail.com [Engineering Physics, Faculty of Industrial Technology, Institut Teknologi Bandung, Jalan Ganesa 10 Bandung and Centre for Material and Technical Product, Jalan Sangkuriang No. 14 Bandung (Indonesia); Tjokronegoro, H. A.; Leksono, E. [Engineering Physics, Faculty of Industrial Technology, Institut Teknologi Bandung, Jalan Ganesa 10 Bandung (Indonesia); Ismunandar [Chemistry Study, Faculty of Mathematics and Science, Institut Teknologi Bandung, Jalan Ganesa 10 Bandung (Indonesia)

    2014-09-25

    Fuel cells are promising new energy conversion devices that are friendly to the environment. A set of control systems are required in order to operate a fuel cell based power plant system optimally. For the purpose of control system design, an accurate fuel cell stack model in describing the dynamics of the real system is needed. Currently, linear model are widely used for fuel cell stack control purposes, but it has limitations in narrow operation range. While nonlinear models lead to nonlinear control implemnetation whos more complex and hard computing. In this research, nonlinear cancellation technique will be used to transform a nonlinear model into a linear form while maintaining the nonlinear characteristics. The transformation is done by replacing the input of the original model by a certain virtual input that has nonlinear relationship with the original input. Then the equality of the two models is tested by running a series of simulation. Input variation of H2, O2 and H2O as well as disturbance input I (current load) are studied by simulation. The error of comparison between the proposed model and the original nonlinear model are less than 1 %. Thus we can conclude that nonlinear cancellation technique can be used to represent fuel cell nonlinear model in a simple linear form while maintaining the nonlinear characteristics and therefore retain the wide operation range.

  7. Hybrid Organic - Inorganic Polymer Electrolyte Membranes for Low to Medium Temperature Fuel Cells

    NARCIS (Netherlands)

    Cordova Chavez, M.E.

    2017-01-01

    Crude oil, coal and gas are currently the main resources of energy in the world. The World Energy Outlook claimed in 2007 that the major source of energy (about 84%) would still be generated from fossil fuels in 2030. By these projections, the world's fossil fuel reserves will be consumed within a

  8. Modelling and Evaluation of Heating Strategies for High Temperature Polymer Electrolyte Membrane Fuel Cell Stacks

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2008-01-01

    Experiments were conducted on two different cathode air cooled high temperature PEM (HTPEM) fuel cell stacks; a 30 cell 400W prototype stack using two bipolar plates per cell, and a 65 cell 1 kW commercial stack using one bipolar plate per cell. The work seeks to examine the use of different...... model to simulate the temperature development of a fuel cell stack during heating can be used for assistance in system and control design. The heating strategies analyzed and tested reduced the startup time of one of the fuel cell stacks from 1 h to about 6 min....

  9. Characterization of internal wetting in polymer electrolyte membrane gas diffusion layers

    Science.gov (United States)

    Cheung, Perry; Fairweather, Joseph D.; Schwartz, Daniel T.

    Capillary pressure vs. saturation (P C(S L)) curves are fundamental to understanding liquid water transport and flooding in PEM gas diffusion layers (GDLs). P C(S L) curves convolute the influence of GDL pore geometry and internal contact angles at the three-phase liquid/solid/gas boundary. Even simple GDL materials are a spatially non-uniform mixture of carbon fiber and binder, making a Gaussian distribution of contact angles likely, based on the Cassie-Baxter equation. For a given Gaussian contact angle distribution with mean (θ Mean) and standard deviation (σ), a realistic P C(S L) curve can be computed using a bundle of capillaries model and GDL pore size distribution data. As expected, computed P C(S L) curves show that θ Mean sets the overall hydrophilic (θ Mean 90°) character of the GDL (i.e., liquid saturation level at a given capillary pressure), and σ affects the slope of the P C(S L) curve. The capillary bundle model also can be used with (θ Mean, σ) as unknown parameters that are best-fit to experimentally acquired P C(S L) and pore size distribution data to find (θ Mean, σ) values for actual GDL materials. To test this, pore size distribution data was acquired for Toray TGP-H-090 along with hysteretic liquid and gas intrusion capillary pressure curve data. High quality best-fits were found between the model and combined datasets, with GDL liquid intrusion showing fairly neutral internal surface wetting properties (θ Mean = 92° and σ = 10°) whereas gas intrusion displayed a hydrophilic character (θ Mean = 52° and σ = 8°). External liquid advancing and receding contact angles were also measured on this same material and they also showed major hysteresis. The new methods described here open the door for better understanding of the link between GDL material processing and the wetting properties that affect flooding.

  10. Parametric Sensitivity Tests—European Polymer Electrolyte Membrane Fuel Cell Stack Test Procedures

    DEFF Research Database (Denmark)

    Araya, Samuel Simon; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2014-01-01

    performed based on test procedures proposed by a European project, Stack-Test. The sensitivity of a Nafion-based low temperature PEMFC stack’s performance to parametric changes was the main objective of the tests. Four crucial parameters for fuel cell operation were chosen; relative humidity, temperature......As fuel cells are increasingly commercialized for various applications, harmonized and industry-relevant test procedures are necessary to benchmark tests and to ensure comparability of stack performance results from different parties. This paper reports the results of parametric sensitivity tests......, pressure, and stoichiometry at varying current density. Furthermore, procedures for polarization curve recording were also tested both in ascending and descending current directions....

  11. Flow maldistribution in the anode of a polymer electrolyte membrane electrolysis cell employing interdigitated channels

    DEFF Research Database (Denmark)

    Olesen, Anders Christian; Kær, Søren Knudsen

    2014-01-01

    of liquid water towards the catalytic layer of the electrode. As opposed to the more common serpentine and parallel channels, interdigitated channels force liquid water through the porous gas diffusion layer (GDL) of the electrode. This improves the supply of water, however it increases pressure losses......-circular cell design on the distribution of water in the anode. In the electrolysis of water using PEMEC the anode is fed by demineralized water. Throughout the anode, oxygen is produced and a two-phase flow develops. Interdigitated channels assist in avoiding that gaseous oxygen obstructs the transport......: water stoichiometry, temperature, GDL permeability and thickness. In conclusion, it is found that the interdigitated flow field results in an uneven distribution across the cell and that the extent depends strongly on the permeability and weaker on the remaining parameters....

  12. Poly(imide benzimidazole)s for high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Yuan, Sen; Guo, Xiaoxia; Aili, David

    2014-01-01

    A series of poly(imide benzimidazole) random copolymers (PIBIs) was synthesized by condensation polymerization of biphenyl-4,4'-diyldi(oxo)-4,4'-bis(1,8-naphthalenedicarboxylic anhydride) (BPNDA), 2-(4-aminophenyl)-5-aminobenzimidazole (APABI) and 4,4'diaminodiphenyl ether (ODA) in m-cresol in th......A series of poly(imide benzimidazole) random copolymers (PIBIs) was synthesized by condensation polymerization of biphenyl-4,4'-diyldi(oxo)-4,4'-bis(1,8-naphthalenedicarboxylic anhydride) (BPNDA), 2-(4-aminophenyl)-5-aminobenzimidazole (APABI) and 4,4'diaminodiphenyl ether (ODA) in m...

  13. Nonlinear modelling of polymer electrolyte membrane fuel cell stack using nonlinear cancellation technique

    International Nuclear Information System (INIS)

    Barus, R. P. P.; Tjokronegoro, H. A.; Leksono, E.; Ismunandar

    2014-01-01

    Fuel cells are promising new energy conversion devices that are friendly to the environment. A set of control systems are required in order to operate a fuel cell based power plant system optimally. For the purpose of control system design, an accurate fuel cell stack model in describing the dynamics of the real system is needed. Currently, linear model are widely used for fuel cell stack control purposes, but it has limitations in narrow operation range. While nonlinear models lead to nonlinear control implemnetation whos more complex and hard computing. In this research, nonlinear cancellation technique will be used to transform a nonlinear model into a linear form while maintaining the nonlinear characteristics. The transformation is done by replacing the input of the original model by a certain virtual input that has nonlinear relationship with the original input. Then the equality of the two models is tested by running a series of simulation. Input variation of H2, O2 and H2O as well as disturbance input I (current load) are studied by simulation. The error of comparison between the proposed model and the original nonlinear model are less than 1 %. Thus we can conclude that nonlinear cancellation technique can be used to represent fuel cell nonlinear model in a simple linear form while maintaining the nonlinear characteristics and therefore retain the wide operation range

  14. Composite Membrane with Underwater-Oleophobic Surface for Anti-Oil-Fouling Membrane Distillation.

    Science.gov (United States)

    Wang, Zhangxin; Hou, Deyin; Lin, Shihong

    2016-04-05

    In this study, we fabricated a composite membrane for membrane distillation (MD) by modifying a commercial hydrophobic polyvinylidene fluoride (PVDF) membrane with a nanocomposite coating comprising silica nanoparticles, chitosan hydrogel and fluoro-polymer. The composite membrane exhibits asymmetric wettability, with the modified surface being in-air hydrophilic and underwater oleophobic, and the unmodified surface remaining hydrophobic. By comparing the performance of the composite membrane and the pristine PVDF membrane in direct contact MD experiments using a saline emulsion with 1000 ppm crude oil (in water), we showed that the fabricated composite membrane was significantly more resistant to oil fouling compared to the pristine hydrophobic PVDF membrane. Force spectroscopy was conducted for the interaction between an oil droplet and the membrane surface using a force tensiometer. The difference between the composite membrane and the pristine PVDF membrane in their interaction with an oil droplet served to explain the difference in the fouling propensities between these two membranes observed in MD experiments. The results from this study suggest that underwater oleophobic coating can effectively mitigate oil fouling in MD operations, and that the fabricated composite membrane with asymmetric wettability can enable MD to desalinate hypersaline wastewater with high concentrations of hydrophobic contaminants.

  15. Ion Transport and Structure in Polymer Electrolytes with Applications in Lithium Batteries

    Science.gov (United States)

    Chintapalli, Mahati

    When mixed with lithium salts, polymers that contain more than one chemical group, such as block copolymers and endgroup-functionalized polymers, are promising electrolyte materials for next-generation lithium batteries. One chemical group can provide good ion solvation and transport properties, while the other chemical group can provide secondary properties that improve the performance characteristics of the battery. Secondary properties of interest include non-flammability for safer lithium ion batteries and high mechanical modulus for dendrite resistance in high energy density lithium metal batteries. Block copolymers and other materials with multiple chemical groups tend to exhibit nanoscale heterogeneity and can undergo microphase separation, which impacts the ion transport properties. In block copolymers that microphase separate, ordered self-assembled structures occur on longer length scales. Understanding the interplay between structure at different length scales, salt concentration, and ion transport is important for improving the performance of multifunctional polymer electrolytes. In this dissertation, two electrolyte materials are characterized: mixtures of endgroup-functionalized, short chain perfluoropolyethers (PFPEs) and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt, and mixtures of polystyrene-block-poly(ethylene oxide) (PS- b-PEO; SEO) and LiTFSI. The PFPE/LiTFSI electrolytes are liquids in which the PFPE backbone provides non-flammability, and the endgroups resemble small molecules that solvate ions. In these electrolytes, the ion transport properties and nanoscale heterogeneity (length scale 1 nm) are characterized as a function of endgroup using electrochemical techniques, nuclear magnetic resonance spectroscopy, and wide angle X-ray scattering. Endgroups, especially those containing PEO segments, have a large impact on ionic conductivity, in part because the salt distribution is not homogenous; we find that salt partitions

  16. Hydration and dehydration cycles in polymer electrolyte fuel cells operated with wet anode and dry cathode feed: A neutron imaging and modeling study

    Science.gov (United States)

    García-Salaberri, P. A.; Sánchez, D. G.; Boillat, P.; Vera, M.; Friedrich, K. A.

    2017-08-01

    Proper water management plays an essential role in the performance and durability of Polymer Electrolyte Fuel Cells (PEFCs), but it is challenged by the variety of water transport phenomena that take place in these devices. Previous experimental work has shown the existence of fluctuations between low and high current density levels in PEFCs operated with wet hydrogen and dry air feed. The alternation between both performance states is accompanied by strong changes in the high frequency resistance, suggesting a cyclic hydration and dehydration of the membrane. This peculiar scenario is examined here considering liquid water distributions from neutron imaging and predictions from a 3D two-phase non-isothermal model. The results show that the hydration-dehydration cycles are triggered by the periodic condensation and shedding of liquid water at the anode inlet. The input of liquid water humidifies the anode channel and offsets the membrane dry-out induced by the dry air stream, thus leading to the high-performance state. When liquid water is flushed out of the anode channel, the dehydration process takes over, and the cell comes back to the low-performance state. The predicted amplitude of the current oscillations grows with decreasing hydrogen and increasing air flow rates, in agreement with previous experimental data.

  17. Elaboration and study of fuel cell according to solid polymer electrolyte technology

    Energy Technology Data Exchange (ETDEWEB)

    Novel-Cattin, F

    1990-10-23

    A hydrogen-oxygen fuel cell was built in an attempt to develop a pilot scale fuel cell of a few kW. These fuel cells were based on a polymeric ion exchange membrane commercialized by Dupont de Nemours under the trademark NAFION 117. This work consists in part of the development of different test cells, for electrodes of surface area from 1 to 25 cm{sup 2}. Different types of porous electrodes were also used containing platinum as the electro-catalyst, in the synthesis of composite electrode-membrane electrode ensembles. Different methods of electrode manufacture are detailed in this thesis. These electrodes were characterized by their current potential behaviour under stationary conditions. Different analysis technics, such as the microprobe and electronic microscopy were used. The electrode structure was studied using impedance spectroscopy. A full factorial optimization program was developed in order to optimize the performance of some of these electrodes. The use of the thermoplastic form of the membrane was used as a mean of incorporating the electrodes into the membrane. The transport of water coupled to proton migration across the membrane was also measured. (author). 82 refs., 32 figs., 10 tabs., 11 curves., 14 schemes., 2 appends.

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

    Science.gov (United States)

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

    2015-05-01

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

  19. 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.

  20. The electrolyte challenge for a direct methanol-air polymer electrolyte fuel cell operating at temperatures up to 200 C

    Science.gov (United States)

    Savinell, Robert; Yeager, Ernest; Tryk, Donald; Landau, Uziel; Wainright, Jesse; Gervasio, Dominic; Cahan, Boris; Litt, Morton; Rogers, Charles; Scherson, Daniel

    1993-01-01

    Novel polymer electrolytes are being evaluated for use in a direct methanol-air fuel cell operating at temperatures in excess of 100 C. The evaluation includes tests of thermal stability, ionic conductivity, and vapor transport characteristics. The preliminary results obtained to date indicate that a high temperature polymer electrolyte fuel cell is feasible. For example, Nafion 117 when equilibrated with phosphoric acid has a conductivity of at least 0.4 Omega(exp -1)cm(exp -1) at temperatures up to 200 C in the presence of 400 torr of water vapor and methanol vapor cross over equivalent to 1 mA/cm(exp 2) under a one atmosphere methanol pressure differential at 135 C. Novel polymers are also showing similar encouraging results. The flexibility to modify and optimize the properties by custom synthesis of these novel polymers presents an exciting opportunity to develop an efficient and compact methanol fuel cell.