WorldWideScience

Sample records for polymer-electrolyte fuel cell

  1. 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...

  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. 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.

  4. 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...

  5. 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.

  6. 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

  7. 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.

  8. 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)

  9. 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.

  10. 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

  11. 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)

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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...

  20. 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.

  1. 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

  2. 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

    Polymer electrolyte fuel cells (PEFC) have a complex electrode structure, which usually consists of a catalyst, a catalyst support, a polymer electrolyte and pores. The materials used are largely amorphous, have a strong defective structure or have particle diameter of only a few nanometers. In the electrode the materials form highly disordered aggregated structures. Both aspects complicate a systematic structural analysis significantly. However, thorough knowledge of the electrode structure, is needed for systematic advancement of fuel cell technology and to obtain a better understanding of mass and charge carrier transport processes in the electrode. Because of the complex structure of the electrode, an approach based on the examination of electrode thin-sections by electron microscopy was chosen in this work to depicting the electrode structure experimentally. The present work presents these studies of the electrode structure. Some fundamental issues as the influence of the polymer electrolyte concentration and the polarity of the solvent used in the electrode manufacturing process were addressed. During the analysis particular attention was payed to the distribution and structure of the polymer electrolyte. A major problem to the investigations, were the low contrast between the polymer electrolyte, the catalyst support material and the embedding resin. Therefore, dilerent techniques were investigated in terms of their ability to improve the contrast. In this context, a computer-assisted acquisition procedure for energy filtered transmission electron microscopy (EF-TEM) was developed. The acquisition procedure permits a significant extension of the imageable sample. At the same time, it was possible to substantially reduce beam damage of the specimen and to minimize drift of the sample considerably. This allowed unambiguous identification of the polymer electrolyte in the electrode. It could further be shown, that the polymer electrolyte not only coats the

  3. 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...

  4. 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...

  5. 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.

  6. 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)

  7. 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).

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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....

  15. 300 W polymer electrolyte fuel cell generators for educational purposes

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-08-01

    A 300 W fuel cell power pack has been developed for educational purposes in close collaboration with the Fachhochschule Solothurn Nordwestschweiz. The project was initiated and financed by the Swiss Federal Office of Energy. The outlay and the performance of the power pack are described. (author) 3 figs.

  16. 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.)

  17. 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.

  18. Operando Raman Micro Spectroscopy of Polymer Electrolyte Fuel Cells

    Science.gov (United States)

    2016-01-16

    the cathode , transitions ion exchange sites from the sulfonic acid to the dissociated sulfonate form. Visualization of density functional theory...catalysts dispersed in an alcoholic dispersion of solubilized ionomer (e.g., Nafion). Teflon dispersion is included in cathode inks to lower the surface...tolerant of condensed water, is complementary to FTIR. Operando Raman spectroscopy of solid oxide fuel cells has been reported.28–30 Although there are

  19. 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.

  20. 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

  1. 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....

  2. 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.

  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. 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. 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.

  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. 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.

  8. 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.)

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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...

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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...

  20. 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

  1. 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.

  2. 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.

  3. 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...

  4. 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

  5. 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...

  6. 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...

  7. 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.

  8. 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)

  9. 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.

  10. 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.)

  11. 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.

  12. 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.

  13. 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)

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

    Science.gov (United States)

    Xiao, Lixiang

    Recent advances have made polymer electrolyte membrane fuel cells (PEMFCs) a leading alternative to internal combustion engines for both stationary and transportation applications. In particular, high temperature polymer electrolyte membranes operational above 120°C without humidification offer many advantages including fast electrode kinetics, high tolerance to fuel impurities and simple thermal and water management systems. A series of polybenzimidazole (PBI) derivatives including pyridine-based PBI (PPBI) and sulfonated PBI (SPBI) homopolymers and copolymers have been synthesized using polyphosphoric acid (PPA) as both solvent and polycondensation agent. High molecular weight PBI derivative polymers were obtained with well controlled backbone structures in terms of pyridine ring content, polymer backbone rigidity and degree of sulfonation. A novel process, termed the PPA process, has been developed to prepare phosphoric acid (PA) doped PBI membranes by direct-casting of the PPA polymerization solution without isolation or re-dissolution of the polymers. The subsequent hydrolysis of PPA to PA by moisture absorbed from the atmosphere usually induced a transition from the solution-like state to a gel-like state and produced PA doped PBI membranes with a desirable suite of physiochemical properties characterized by the PA doping levels, mechanical properties and proton conductivities. The effects of the polymer backbone structure on the polymer characteristics and membrane properties, i.e., the structure-property relationships of the PBI derivative polymers have been studied. The incorporation of additional basic nitrogen containing pyridine rings and sulfonic acid groups enhanced the polymer solubility in acid and dipolar solvents while retaining the inherently high thermal stability of the PBI heteroaromatic backbone. In particular, the degradation of the SPBI polymers with reasonable high molecular weights commenced above 450°C, notably higher than other

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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)

  1. 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)

  2. 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)

  3. 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.

  4. 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.

  5. 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).

  6. 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.

  7. 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.)

  8. 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

  9. Investigation of freeze/thaw durability in polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Soo-Jin; Park, Gu-Gon; Sohn, Young-Jun; Yim, Sung-Dae; Yang, Tae-Hyun; Kim, Chang-Soo [Fuel Cell Research Center, Korea Institute of Energy Research, 102, Gajeong-ro, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Park, Jin-Soo [Department of Environmental Engineering, College of Engineering, Sanmyung University, 300 Anseo-dong, Dongnam-gu, Cheonam, Chungnam Province 330-720 (Korea, Republic of); Hong, Bo Ki [Fuel Cell Vehicle Team 1, Ecotechnology Center, Hyundai-Kia Motors Company, 104, Mabuk-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-912 (Korea, Republic of)

    2010-12-15

    This study aims to investigate the effect of different gas diffusion layers (GDLs) on freeze/thaw condition durability in polymer electrolyte fuel cells (PEFCs). Three kinds of GDLs-cloth, felt and paper type - with similar basic properties except thickness and bending stiffness were used. The changes in the properties and cell performance were investigated from the -30 to 70 C range of freeze/thaw cycles. The I-V performance degradation was observed to be negligible for the felt GDL whereas the cloth and paper GDLs showed a marked I-V performance loss. No distinctive correlation between the changes in electrochemical properties, such as active metal surface area, hydrogen crossover rates and decreased I-V performance, was observed except an increase in ohmic resistance revealed by ac-impedance spectroscopy. The physical destruction of electrodes was also shown by scanning electron microscope (SEM) analysis. The present study found that sufficient mechanical supporting force between the interfaces of materials enhances PEFC durability in sub-zero temperature conditions. (author)

  10. 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)

  11. 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...

  12. 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....

  13. 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.

  14. 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)

  15. 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....

  16. 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.

  17. Mathematical Modeling of Transport Phenomena in Polymer Electrolyte and Direct Methanol Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Birgersson, Erik

    2004-02-01

    This thesis deals with modeling of two types of fuel cells: the polymer electrolyte fuel cell (PEFC) and the direct methanol fuel cell (DMFC), for which we address four major issues: a) mass transport limitations; b) water management (PEFC); c) gas management (DMFC); d) thermal management. Four models have been derived and studied for the PEFC, focusing on the cathode. The first exploits the slenderness of the cathode for a two-dimensional geometry, leading to a reduced model, where several non dimensional parameters capture the behavior of the cathode. The model was extended to three dimensions, where four different flow distributors were studied for the cathode. A quantitative comparison shows that the interdigitated channels can sustain the highest current densities. These two models, comprising isothermal gas phase flow, limit the studies to (a). Returning to a two-dimensional geometry of the PEFC, the liquid phase was introduced via a separate flow model approach for the cathode. In addition to conservation of mass, momentum and species, the model was extended to consider simultaneous charge and heat transfer for the whole cell. Different thermal, flow fields, and hydrodynamic conditions were studied, addressing (a), (b) and (d). A scale analysis allowed for predictions of the cell performance prior to any computations. Good agreement between experiments with a segmented cell and the model was obtained. A liquid-phase model, comprising conservation of mass, momentum and species, was derived and analyzed for the anode of the DMFC. The impact of hydrodynamic, electrochemical and geometrical features on the fuel cell performance were studied, mainly focusing on (a). The slenderness of the anode allows the use of a narrow-gap approximation, leading to a reduced model, with benefits such as reduced computational cost and understanding of the physical trends prior to any numerical computations. Adding the gas-phase via a multiphase mixture approach, the gas

  18. 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

  19. 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

  20. 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)

  1. 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...

  2. In situ diagnostic of two-phase flow phenomena in polymer electrolyte fuel cells by neutron imaging

    International Nuclear Information System (INIS)

    Kramer, Denis; Zhang, Jianbo; Shimoi, Ryoichi; Lehmann, Eberhard; Wokaun, Alexander; Shinohara, Kazuhiko; Scherer, Guenther G.

    2005-01-01

    Neutron radiographical measurements have been performed on operating hydrogen-fueled polymer electrolyte fuel cells (PEFC). With the successful detection of liquid accumulation in flow field and gas diffusion layer (GDL) under various operating conditions a unique experimental approach for the investigation of two-phase flow phenomena in technical PEFC has been realized. The experimental setup will be described in detail. Algorithms for an enhanced quantitative evaluation of the obtained images are presented and successful application to the data demonstrated. Finally, results from PEFC investigations will be given. Different flow field geometries and their implications for liquid accumulation inside flow field and GDL are discussed

  3. 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.

  4. Testing of a De Nora polymer electrolyte fuel cell stack of 1 kW for naval applications

    Science.gov (United States)

    Schmal, D.; Kluiters, C. E.; Barendregt, I. P.

    In a previous study calculations were carried out for a navy frigate with respect to the energy consumption of a propulsion/electricity generation system based on fuel cells. The fuel consumption for the 'all-fuel cell' ship was compared with the consumption of the current propulsion/electricity generation system based on gas turbines and diesel engines; it showed potential energy savings of a fuel cell based system amounting from 25 to 30%. On the basis of these results and taking into account various military aspects it was decided to start tests with a polymer electrolyte fuel cell (PEFC) stack. For this purpose a De Nora 1 kW PEFC was chosen. Results of the first tests after installation are satisfying.

  5. 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

  6. 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...

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. Heat and fuel coupled operation of a high temperature polymer electrolyte fuel cell with a heat exchanger methanol steam reformer

    Science.gov (United States)

    Schuller, G.; Vázquez, F. Vidal; Waiblinger, W.; Auvinen, S.; Ribeirinha, P.

    2017-04-01

    In this work a methanol steam reforming (MSR) reactor has been operated thermally coupled to a high temperature polymer electrolyte fuel cell stack (HT-PEMFC) utilizing its waste heat. The operating temperature of the coupled system was 180 °C which is significantly lower than the conventional operating temperature of the MSR process which is around 250 °C. A newly designed heat exchanger reformer has been developed by VTT (Technical Research Center of Finland LTD) and was equipped with commercially available CuO/ZnO/Al2O3 (BASF RP-60) catalyst. The liquid cooled, 165 cm2, 12-cell stack used for the measurements was supplied by Serenergy A/S. The off-heat from the electrochemical fuel cell reaction was transferred to the reforming reactor using triethylene glycol (TEG) as heat transfer fluid. The system was operated up to 0.4 A cm-2 generating an electrical power output of 427 Wel. A total stack waste heat utilization of 86.4% was achieved. It has been shown that it is possible to transfer sufficient heat from the fuel cell stack to the liquid circuit in order to provide the needed amount for vaporizing and reforming of the methanol-water-mixture. Furthermore a set of recommendations is given for future system design considerations.

  12. Rapid evaluation of the electrooxidation of fuel compounds with a multiple-electrode setup for direct polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, Naoko; Siroma, Zyun; Ioroi, Tsutomu; Yasuda, Kazuaki [Research Institute for Ubiquitous Energy Devices, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

    2007-02-10

    Electrochemical oxidation of fuel compounds in acidic media was examined on eight electrodes (Pt, Ru, PtRu, Rh, Ir, Pd, Au, and glassy carbon) simultaneously by multiple cyclic voltammetry (CV) with an electrochemical cell equipped with an eight-electrode configuration. Direct-type polymer electrolyte fuel cells (PEFCs), in which aqueous solutions of the fuel compounds are directly supplied to the anode, were also evaluated. The performances of direct PEFCs with various anode catalysts could be roughly estimated from the results obtained with multiple CV. This multiple evaluation may be useful for identifying novel fuels or electrocatalysts. Methanol, ethanol, ethylene glycol, 2-propanol, and D-glucose were oxidized selectively on Pt or PtRu, as reported previously. However, several compounds that are often used as reducing agents show electrochemical oxidation with unique characteristics. Large current was obtained for the oxidation of formic acid, hypophosphorous acid, and phosphorous acid on a Pd electrode. L-Ascorbic acid and sulfurous acid were oxidized on all of the electrodes used in the present study. (author)

  13. Performance comparison of protonic and sodium phosphomolybdovanadate polyoxoanion catholytes within a chemically regenerative redox cathode polymer electrolyte fuel cell

    Science.gov (United States)

    Ward, David B.; Gunn, Natasha L. O.; Uwigena, Nadine; Davies, Trevor J.

    2018-01-01

    The direct reduction of oxygen in conventional polymer electrolyte fuel cells (PEFCs) is seen by many researchers as a key challenge in PEFC development. Chemically regenerative redox cathode (CRRC) polymer electrolyte fuel cells offer an alternative approach via the indirect reduction of oxygen, improving durability and reducing cost. These systems substitute gaseous oxygen for a liquid catalyst that is reduced at the cathode then oxidised in a regeneration vessel via air bubbling. A key component of a CRRC system is the liquid catalyst or catholyte. To date, phosphomolybdovanadium polyoxometalates with empirical formula H3+nPVnMo12-nO40 have shown the most promise for CRRC PEFC systems. In this work, four catholyte formulations are studied and compared against each other. The catholytes vary in vanadium content, pH and counter ion, with empirical formulas H6PV3Mo9O40, H7PV4Mo8O40, Na3H3PV3Mo9O40 and Na4H3PV4Mo8O40. Thermodynamic properties, cell performance and regeneration rates are measured, generating new insights into how formulation chemistry affects the components of a CRRC system. The results include the best CRRC PEFC performance reported to date, with noticeable advantages over conventional PEFCs. The optimum catholyte formulation is then determined via steady state tests, the results of which will guide further optimization of the catholyte formulation.

  14. 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.

  15. 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.

  16. 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.

  17. 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 ...

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. In situ diagnostic of two-phase flow phenomena in polymer electrolyte fuel cells by neutron imaging

    International Nuclear Information System (INIS)

    Zhang Jianbo; Kramer, Denis; Shimoi, Ryoichi; Ono, Yoshitaka; Lehmann, Eberhard; Wokaun, Alexander; Shinohara, Kazuhiko; Scherer, Guenther G.

    2006-01-01

    The formation of liquid water in operating polymer electrolyte fuel cells (PEFC) of industrial and laboratory size has been investigated by in situ neutron imaging. The influence of the materials chosen for the structural components of the cell on droplet formation and transport in flow fields and on liquid formation in gas diffusion layers has been studied. The changing of the cathodic gas diffusion layer material allowed the relationship between materials, liquid accumulation, and electrochemical performance to be examined. It has been shown that material choice has considerable bearing on the presence of liquid inside the porous structures and the electrochemical characteristics. A simplified quasi one-dimensional cell with an active area of 25 cm 2 was used for materials comparison, and the results were related to technically relevant operating conditions - where inhomogeneities have to be considered - by subsequent examination of cells with an active area of 100 cm 2

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. Nanographene synthesized in triple-phase plasmas as a highly durable support of catalysts for polymer electrolyte fuel cells

    Science.gov (United States)

    Amano, Tomoki; Kondo, Hiroki; Takeda, Keigo; Ishikawa, Kenji; Hiramatsu, Mineo; Sekine, Makoto; Hori, Masaru

    2018-04-01

    Nanographene was synthesized in triple-phase plasmas comprising a gaseous phase, a gas-liquid boundary layer, and an in-liquid phase using a setup in which one electrode was placed in the gaseous phase while the other was immersed in the liquid phase. The triple-phase plasmas were generated using a pure alcohol, such as ethanol, 1-propanol, or 1-butanol, by applying a high voltage to a pair of electrodes made of copper or graphite. The nanographene synthesized using ethanol had high durability and thus could serve as a catalyst support in polymer electrolyte fuel cells (PEFCs). The PEFCs exhibited low degradation rates in the high-potential cycle test of a half-cell, as a result of which, a loss of only 10% was observed in the effective electrochemical surface area of Pt, even after 10,000 cycles.

  9. 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.

  10. 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...

  11. Pore-Network Modeling of Water and Vapor Transport in the Micro Porous Layer and Gas Diffusion Layer of a Polymer Electrolyte Fuel Cell

    NARCIS (Netherlands)

    Qin, C.; Hassanizadeh, S.M.; van Oosterhout, L.M.

    2016-01-01

    In the cathode side of a polymer electrolyte fuel cell (PEFC), a micro porous layer (MPL) added between the catalyst layer (CL) and the gas diffusion layer (GDL) plays an important role in water management. In this work, by using both quasi-static and dynamic pore-network models, water and vapor

  12. 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

  13. 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)

  14. 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.

  15. Current advances in polymer electrolyte fuel cells based on the promotional role of under-rib convection

    Energy Technology Data Exchange (ETDEWEB)

    Choi, K.S. [Industrial Technology Cooperation Center, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Kim, B.G.; Park, K.; Kim, H.M. [Department of Mechanical Engineering and High Safety Vehicle Core Technology Research Center, INJE University, 607 Eobang-dong, Gimhae, Gyeongnam 621-749 (Korea, Republic of)

    2012-12-15

    Literature data on the promotional role of under-rib convection for polymer electrolyte fuel cells (PEFCs) fueled by hydrogen and methanol are structured and analyzed, thus providing a guide to improving fuel cell performance through the optimization of flow field interaction. Data are presented for both physical and electrochemical performance showing reactant mass transport, electrochemical reaction, water behavior, and power density enhanced by under-rib convection. Performance improvement studies ranging from single cell to stack are presented for measuring the performance of real operating conditions and large-scale setups. The flow field optimization techniques by under-rib convection are derived from the collected data over a wide range of experiments and modeling studies with a variety of components including both single cell and stack arrangements. Numerical models for PEFCs are presented with an emphasis on mass transfer and electrochemical reaction inside the fuel cell. The models are primarily used here as a tool in the parametric analysis of significant design features and to permit the design of the experiment. Enhanced flow field design that utilizes the promotional role of under-rib convection can contribute to commercializing PEFCs. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. 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.

  17. 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.

  18. Hardware/Software Data Acquisition System for Real Time Cell Temperature Monitoring in Air-Cooled Polymer Electrolyte Fuel Cells.

    Science.gov (United States)

    Segura, Francisca; Bartolucci, Veronica; Andújar, José Manuel

    2017-07-09

    This work presents a hardware/software data acquisition system developed for monitoring the temperature in real time of the cells in Air-Cooled Polymer Electrolyte Fuel Cells (AC-PEFC). These fuel cells are of great interest because they can carry out, in a single operation, the processes of oxidation and refrigeration. This allows reduction of weight, volume, cost and complexity of the control system in the AC-PEFC. In this type of PEFC (and in general in any PEFC), the reliable monitoring of temperature along the entire surface of the stack is fundamental, since a suitable temperature and a regular distribution thereof, are key for a better performance of the stack and a longer lifetime under the best operating conditions. The developed data acquisition (DAQ) system can perform non-intrusive temperature measurements of each individual cell of an AC-PEFC stack of any power (from watts to kilowatts). The stack power is related to the temperature gradient; i.e., a higher power corresponds to a higher stack surface, and consequently higher temperature difference between the coldest and the hottest point. The developed DAQ system has been implemented with the low-cost open-source platform Arduino, and it is completed with a modular virtual instrument that has been developed using NI LabVIEW. Temperature vs time evolution of all the cells of an AC-PEFC both together and individually can be registered and supervised. The paper explains comprehensively the developed DAQ system together with experimental results that demonstrate the suitability of the system.

  19. Hardware/Software Data Acquisition System for Real Time Cell Temperature Monitoring in Air-Cooled Polymer Electrolyte Fuel Cells

    Directory of Open Access Journals (Sweden)

    Francisca Segura

    2017-07-01

    Full Text Available This work presents a hardware/software data acquisition system developed for monitoring the temperature in real time of the cells in Air-Cooled Polymer Electrolyte Fuel Cells (AC-PEFC. These fuel cells are of great interest because they can carry out, in a single operation, the processes of oxidation and refrigeration. This allows reduction of weight, volume, cost and complexity of the control system in the AC-PEFC. In this type of PEFC (and in general in any PEFC, the reliable monitoring of temperature along the entire surface of the stack is fundamental, since a suitable temperature and a regular distribution thereof, are key for a better performance of the stack and a longer lifetime under the best operating conditions. The developed data acquisition (DAQ system can perform non-intrusive temperature measurements of each individual cell of an AC-PEFC stack of any power (from watts to kilowatts. The stack power is related to the temperature gradient; i.e., a higher power corresponds to a higher stack surface, and consequently higher temperature difference between the coldest and the hottest point. The developed DAQ system has been implemented with the low-cost open-source platform Arduino, and it is completed with a modular virtual instrument that has been developed using NI LabVIEW. Temperature vs time evolution of all the cells of an AC-PEFC both together and individually can be registered and supervised. The paper explains comprehensively the developed DAQ system together with experimental results that demonstrate the suitability of the system.

  20. 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.

  1. Advanced control of liquid water region in diffusion media of polymer electrolyte fuel cells through a dimensionless number

    Science.gov (United States)

    Wang, Yun; Chen, Ken S.

    2016-05-01

    In the present work, a three-dimension (3-D) model of polymer electrolyte fuel cells (PEFCs) is employed to investigate the complex, non-isothermal, two-phase flow in the gas diffusion layer (GDL). Phase change in gas flow channels is explained, and a simplified approach accounting for phase change is incorporated into the fuel cell model. It is found that the liquid water contours in the GDL are similar along flow channels when the channels are subject to two-phase flow. Analysis is performed on a dimensionless parameter Da0 introduced in our previous paper [Y. Wang and K. S. Chen, Chemical Engineering Science 66 (2011) 3557-3567] and the parameter is further evaluated in a realistic fuel cell. We found that the GDL's liquid water (or liquid-free) region is determined by the Da0 number which lumps several parameters, including the thermal conductivity and operating temperature. By adjusting these factors, a liquid-free GDL zone can be created even though the channel stream is two-phase flow. Such a liquid-free zone is adjacent to the two-phase region, benefiting local water management, namely avoiding both severe flooding and dryness.

  2. 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...

  3. 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....

  4. 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

  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. 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.

  7. Investigation of concentration overpotential distribution in a polymer electrolyte fuel cell. Paper no. IGEC-1-081

    International Nuclear Information System (INIS)

    Tajiri, K.; Yang, X.-G.; Wang, C.-Y.; Shinohara, K.

    2005-01-01

    Simultaneous measurement of current and high frequency resistance (HFR) distributions has been performed using a segmented polymer electrolyte fuel cell operated with H 2 /air. Each flow plate consisted of twelve segments along a serpentine flow field. Two types of gas diffusion layer (GDL), a treated hydrophobic carbon cloth coated with a microporous layer (MPL) on one side, and an untreated hydrophilic carbon cloth without MPL, were studied and contrasted. The total voltage loss is divided into three overpotentials: the activation, ohmic and concentration; and the concentration overpotential and its distribution are analyzed in detail. While the fuel cell using the GDL with MPL features a nearly uniform concentration overpotential profile, the one without-MPL shows an increase in concentration overpotential along the cathode flow. When the local concentration overpotential is plotted against the local oxygen concentration, the carbon cloth GDL without MPL showed a steeply increasing concentration overpotential with decreasing oxygen concentration, indicating a high sensitivity to the oxygen content. The same trend was observed for the GDL without MPL under lower relative humidity gases. It is thus found that the increase in concentration overpotential with decreasing oxygen concentration is related to the absence of MPL. (author)

  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. 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

  10. 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.)

  11. Particle size dependence of CO tolerance of anode PtRu catalysts for polymer electrolyte fuel cells

    Science.gov (United States)

    Yamanaka, Toshiro; Takeguchi, Tatsuya; Wang, Guoxiong; Muhamad, Ernee Noryana; Ueda, Wataru

    An anode catalyst for a polymer electrolyte fuel cell must be CO-tolerant, that is, it must have the function of hydrogen oxidation in the presence of CO, because hydrogen fuel gas generated by the steam reforming process of natural gas contains a small amount of CO. In the present study, PtRu/C catalysts were prepared with control of the degree of Pt-Ru alloying and the size of PtRu particles. This control has become possible by a new method of heat treatment at the final step in the preparation of catalysts. The CO tolerances of PtRu/C catalysts with the same degree of Pt-Ru alloying and with different average sizes of PtRu particles were thus compared. Polarization curves were obtained with pure H 2 and CO/H 2 (CO concentrations of 500-2040 ppm). It was found that the CO tolerance of highly dispersed PtRu/C (high dispersion (HD)) with small PtRu particles was much higher than that of poorly dispersed PtRu/C (low dispersion (LD)) with large metal particles. The CO tolerance of PtRu/C (HD) was higher than that of any commercial PtRu/C. The high CO tolerance of PtRu/C (HD) is thought to be due to efficient concerted functions of Pt, Ru, and their alloy.

  12. 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.

  13. 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)

  14. 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.

  15. 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.

  16. 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

  17. 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.)

  18. 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...

  19. 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.

  20. 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.

  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. 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...

  3. Pt supported on nanosized oxides for electrocatalyst used in polymer electrolyte fuel cells

    DEFF Research Database (Denmark)

    Banu, N.; Serban, E. C.; Marinescu, A.

    2011-01-01

    Even though Pt is a standard catalyst for fuel cells, new advanced materials with low activation energy and high specific surface area are required. Researches proved that conducting oxides are the emerging candidates as support for Pt catalysts targeting replacement of nanocarbons. This paper pr...

  4. 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

  5. Advanced cathode materials for polymer electrolyte fuel cells based on pt/ metal oxides: from model electrodes to catalyst systems.

    Science.gov (United States)

    Fabbri, Emiliana; Pătru, Alexandra; Rabis, Annett; Kötz, Rüdiger; Schmidt, Thomas J

    2014-01-01

    The development of stable catalyst systems for application at the cathode side of polymer electrolyte fuel cells (PEFCs) requires the substitution of the state-of-the-art carbon supports with materials showing high corrosion resistance in a strongly oxidizing environment. Metal oxides in their highest oxidation state can represent viable support materials for the next generation PEFC cathodes. In the present work a multilevel approach has been adopted to investigate the kinetics and the activity of Pt nanoparticles supported on SnO2-based metal oxides. Particularly, model electrodes made of SnO2 thin films supporting Pt nanoparticles, and porous catalyst systems made of Pt nanoparticles supported on Sb-doped SnO2 high surface area powders have been investigated. The present results indicate that SnO2-based supports do not modify the oxygen reduction reaction mechanism on the Pt nanoparticle surface, but rather lead to catalysts with enhanced specific activity compared to Pt/carbon systems. Different reasons for the enhancement in the specific activity are considered and discussed.

  6. 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.

  7. 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.

  8. 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)

  9. 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.

  10. Investigation of liquid water in gas diffusion layers of polymer electrolyte fuel cells using X-ray tomographic microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Flueckiger, Reto [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Marone, Federica [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Stampanoni, Marco [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, CH-8092 Zurich (Switzerland); Wokaun, Alexander [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Buechi, Felix N., E-mail: felix.buechi@psi.c [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2011-02-01

    In polymer electrolyte fuel cells (PEFCs), condensation of water within the pore network of the gas diffusion layers (GDL) can influence the gas transport properties and thus reduce the electrochemical conversion rates. The use of X-ray tomographic microscopy (XTM), which allows for a resolution in the order of one micrometer is investigated for studying ex situ the local saturation in GDL's. The strength of XTM is the high spatial resolution with simultaneous contrast for water and carbon, allowing for non-destructive 3D-imaging of the solid and the contained water. The application of this method for imaging the ex situ water intrusion into the porous network of GDLs is explored using absorption and phase contrast methods. It is shown that the inhomogeneous filling behavior of GDL materials can indeed be visualized with sufficient resolution. For Toray paper TGP-H-060 the local saturation was measured as function of the water pressure. The results, evaluated in 1D, 2D and 3D show a liquid water retention effect at the denser layers near the surface. A comparison with established capillary pressure functions is presented. Altogether, the results show the potential of the XTM-method as a tool for studying the liquid water behavior in PEFC on a microscopic scale.

  11. Investigation of liquid water in gas diffusion layers of polymer electrolyte fuel cells using X-ray tomographic microscopy

    International Nuclear Information System (INIS)

    Flueckiger, Reto; Marone, Federica; Stampanoni, Marco; Wokaun, Alexander; Buechi, Felix N.

    2011-01-01

    In polymer electrolyte fuel cells (PEFCs), condensation of water within the pore network of the gas diffusion layers (GDL) can influence the gas transport properties and thus reduce the electrochemical conversion rates. The use of X-ray tomographic microscopy (XTM), which allows for a resolution in the order of one micrometer is investigated for studying ex situ the local saturation in GDL's. The strength of XTM is the high spatial resolution with simultaneous contrast for water and carbon, allowing for non-destructive 3D-imaging of the solid and the contained water. The application of this method for imaging the ex situ water intrusion into the porous network of GDLs is explored using absorption and phase contrast methods. It is shown that the inhomogeneous filling behavior of GDL materials can indeed be visualized with sufficient resolution. For Toray paper TGP-H-060 the local saturation was measured as function of the water pressure. The results, evaluated in 1D, 2D and 3D show a liquid water retention effect at the denser layers near the surface. A comparison with established capillary pressure functions is presented. Altogether, the results show the potential of the XTM-method as a tool for studying the liquid water behavior in PEFC on a microscopic scale.

  12. A phenyl-sulfonic acid anchored carbon-supported platinum catalyst for polymer electrolyte fuel cell electrodes

    International Nuclear Information System (INIS)

    Selvarani, G.; Sahu, A.K.; Choudhury, N.A.; Sridhar, P.; Pitchumani, S.; Shukla, A.K.

    2007-01-01

    A method, to anchor phenyl-sulfonic acid functional groups with the platinum catalyst supported onto a high surface-area carbon substrate, is reported. The use of the catalyst in the electrodes of a polymer electrolyte fuel cell (PEFC) helps enhancing its performance. Characterization of the catalyst by Fourier transform infra red (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and point-of-zero-charge (PZC) studies suggests that the improvement in performance of the PEFC is facilitated not only by enlarging the three-phase boundary in the catalyst layer but also by providing ionic-conduction paths as well as by imparting negative charge to platinum sites with concomitant oxidation of sulfur present in the carbon support. It is argued that the negatively charged platinum sites help repel water facilitating oxygen to access the catalyst sites. The PEFC with modified carbon-supported platinum catalyst electrodes exhibits 40% enhancement in its power density as compared to the one with unmodified carbon-supported platinum catalyst electrodes

  13. 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)

  14. 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.

  15. 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.

  16. 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....

  17. 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....

  18. Electrochemically Promoted Organic Isomerization Reactions at Polymer Electrolyte Fuel Cell Cathodes

    Science.gov (United States)

    2011-01-04

    fuel cells ( PEMFCs ) incorporate an ionomer membrane (e.g., Nafion 117) for support of electro- catalytic layers and proton conduction between the...central to PEMFC electrocatalysis. For example, a spin coated Nafion layer on polycrystalline Pt enhances electrocatalysis.7,8 Little is known about...CO Poisoning Effect in PEMFCs Operational at Temperatures up to 200°C. Journal of the Electrochemical Society, 2003. 150(12): p. A1599-A1605. 21

  19. New electrodes for hydrogen/oxygen solid polymer electrolyte fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Mosdale, R [CEA Centre d` Etudes de Grenoble, 38 (France). Dept. de Recherche Fondamentale sur la Matiere Condensee; Stevens, P [CEA Centre d` Etudes de Grenoble, 38 (France). Dept. de Thermohydraulique et de Physique

    1993-12-31

    A new method of preparation of Electrode/Membrane/Electrode (EME) assemblies for Proton Exchange Membrane Fuel Cells (PEMFC) has been developed. The electrodes are deposited directly onto a Nafion electrolyte membrane from a mixture of platinized carbon, Nafion solution, and PTFE by using a spray technique. By this technique, porous electrodes are obtained with an optimized gas/electrolyte/catalyst interface, and electrode/membrane interface.

  20. 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

  1. 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...

  2. 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...

  3. Improved Modeling and Understanding of Diffusion-Media Wettability on Polymer-Electrolyte-Fuel-Cell Performance

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Adam

    2010-03-05

    A macroscopic-modeling methodology to account for the chemical and structural properties of fuel-cell diffusion media is developed. A previous model is updated to include for the first time the use of experimentally measured capillary pressure -- saturation relationships through the introduction of a Gaussian contact-angle distribution into the property equations. The updated model is used to simulate various limiting-case scenarios of water and gas transport in fuel-cell diffusion media. Analysis of these results demonstrate that interfacial conditions are more important than bulk transport in these layers, where the associated mass-transfer resistance is the result of higher capillary pressures at the boundaries and the steepness of the capillary pressure -- saturation relationship. The model is also used to examine the impact of a microporous layer, showing that it dominates the response of the overall diffusion medium. In addition, its primary mass-transfer-related effect is suggested to be limiting the water-injection sites into the more porous gas-diffusion layer.

  4. 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.

  5. Mass transport aspects of polymer electrolyte fuel cells under two-phase flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, D.

    2007-03-27

    This work deals with selected aspects of mass transport phenomena in PEFCs and DMFCs. Emphasis is placed on the implications originating from the occurrence of two-phase flow within these devices. Optimality of supply, distribution, and removal of the fuel, the oxidant, and the reaction products is of utmost importance for the stability, efficiency, and durability of the devices. Being a prerequisite for high current densities while maintaining sufficient voltage, mass transport optimization contributes to the development of cost effective as well as compact designs and hence competitive fuel cells. [German] Die Visualisierung und Quantifizierung von Fluessigwasseransammlungen in Polymerelektrolytmembran-Brennstoffzellen konnte mittels Neutronenradiographie erreicht werden. Dank dieser neuartigen diagnostischen Methode konnte erstmals die Fluessigwasseransammlung in den poroesen Gasdiffusionsschichten direkt nachgewiesen und quantifiziert werden. Die Kombination von Neutronenradiographie mit ortsaufgeloesten Stromdichtemessungen bzw. lokaler Impedanzspektroskopie erlaubte die Korrelation des inhomogenen Fluessigwasseranfalls mit dem lokalen elektrochemischen Leistungsverhalten. Systematische Untersuchungen an Polymerelektrolyt- und Direkt-Methanol-Brennstoffzellen verdeutlichen sowohl den Einfluss von Betriebsbedingungen als auch die Auswirkung von Materialeigenschaften auf die Ausbildung zweiphasiger Stroemungen.

  6. 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....

  7. Cross-linked aromatic cationic polymer electrolytes with enhanced stability for high temperature fuel cell applications

    DEFF Research Database (Denmark)

    Ma, Wenjia; Zhao, Chengji; Yang, Jingshuai

    2012-01-01

    Diamine-cross-linked membranes were prepared from cross-linkable poly(arylene ether ketone) containing pendant cationic quaternary ammonium group (QPAEK) solution by a facile and general thermal curing method using 4,4′-diaminodiphenylmethane with rigid framework and 1,6-diaminohexane with flexible...... anchoring of the molecule. Combining the excellent thermal stability, the addition of a small amount of diamines enhanced both the chemical and mechanical stability and the phosphoric acid doping (PA) ability of membranes. Fuel cell performance based on impregnated cross-linked membranes have been...... successfully operated at temperatures up to 120 °C and 180 °C with unhumidified hydrogen and air under ambient pressure, the maximum performance of diamine-cross-linked membrane is observed at 180 °C with a current density of 1.06 A cm−2 and the peak power density of 323 mW cm−2. The results also indicate...

  8. A Graphite Oxide Paper Polymer Electrolyte for Direct Methanol Fuel Cells

    Directory of Open Access Journals (Sweden)

    Ravi Kumar

    2011-01-01

    Full Text Available A flow directed assembly of graphite oxide solution was used in the formation of free-standing graphene oxide paper of approximate thickness of 100 μm. The GO papers were characterised by XRD and SEM. Electrochemical characterization of the GO paper membrane electrode assembly revealed proton conductivities of 4.1 × 10−2 S cm−1 to 8.2 × 10−2 S cm−1 at temperatures of 25–90°C. A direct methanol fuel cell, at 60°C, gave a peak power density of 8 mW cm−2 at a current density of 35 mA cm−2.

  9. 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.

  10. 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

  11. Modeling and simulation of high-temperature polymer electrolyte fuel cells; Modellierung und Simulation von Hochtemperatur-Polymerelektrolyt-Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Kvesic, Mirko

    2012-07-01

    Fuel cells are electrochemical energy converters that convert chemical energy of constantly fed reactants directly into electricity. The most commonly used fuel gas in this respect is hydrogen, which is either produced in pure form by electrolysis, for example, or as a hydrogen-rich gas mixture (reformate gas), produced by reforming diesel or kerosene e.g. However, a disadvantage of reformate gas is that it contains additional carbon monoxide (CO), which leads to catalyst poisoning in the fuel cell. Since higher operating temperatures also lead to a higher CO tolerance, the use of high-temperature Polymer-Electrolyte-Fuel-Cells (HT-PEFCs) is particularly suitable for reformate operation. The aim of the presented work is the modeling and CFD-simulation of HT-PEFC stacks with the intention of gaining a better understanding of multi-physical processes in the stack operation as well as the optimization and analysis of existing stack designs. The geometric modeling used is based on the Porous Volume Model, which significantly reduces the required number of computing elements. Furthermore, the electrochemical models for hydrogen / air and reformate / air operation, which were taking the CO poisoning effects into account, are developed in this work and implemented in the software ANSYS / Fluent. The resulting simulations indicated the optimal flow configuration for the stack operation in terms of the homogeneous current density distribution, which has a positive effect on the stack aging. Thus, the current densities showed a strong homogeneity regarding the stack configuration anode / cathode in counter-flow and anode / cooling in co-flow. The influence of cooling strategies was examined for the stack performance in a similar way. In the following, the local temperature distribution as well as temperature peaks within the stack could be predicted and validated with experimental measurements. Further on, the model scalability and thus the general validity of the developed

  12. 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.

  13. Influences of Contact Pressure on the Performances of Polymer Electrolyte Fuel Cells

    Directory of Open Access Journals (Sweden)

    Prakash C. Ghosh

    2013-01-01

    Full Text Available Fuel cells face major challenges in sustaining the laboratory-scale performance during the scale up. The contact resistance mainly arises from the dimensional mismatch between gasket and gas diffusion layer during scale up, which may cause diminution in performance. In the present work, experiment as well as modelling is carried out for different combinations of clamping force and gasket thickness. The polarisation behaviours of PEFCs configured under different clamping torques and gasket thicknesses are analysed. The combination of 0.3 mm gasket and 0.3 mm GDL under 3 Nm and 5 Nm clamping forces offers 480 mΩ cm2 and 148 mΩ cm2 contact resistances, respectively. The configurations under 3 Nm and 5 Nm clamping torques with 0.2 mm thick gasket offer contact resistances as low as 23 mΩ cm2 and 11 mΩ cm2, respectively. The polarisation behaviour obtained from the experiment of such configurations is found to be in good agreement with the modelling results.

  14. 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

  15. 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

  16. 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.

  17. 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

  18. 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....

  19. 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...

  20. Polymer electrolyte for lithium batteries and fuel cells - A key element; L'electrolyte polymere pour batterie lithium et piles a combustible. Un element cle

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, J.Y.; Chauvin, C.; Marechal, M.; Saunier, J.; Glandut, N.; Alloin, F.; My Ahmed Said, A.S.; Guindet, J. [Institut National Polytechnique, ENSEEG/INPG, LEPMI, 38 - Grenoble (France); Chabert, F.; El Kissi, N. [Ecole Nationale Superieure d' Hydraulique et de Mecanique de Grenoble, ENSHMG/INPG, 38 - Grenoble (France); Lojoiu, C. [ERAS-Labo 222, 38 - Saint Nazaires les Eymes (France); Dufresne, A. [CERMAV/CNRS, 38 - Grenoble (France)

    2003-10-01

    Fuel cells and lithium batteries based on polymer electrolytes are promising technologies. A global approach of these materials, including their functional as well as their structural properties and the film forming conditions is necessary. At the junction of several scientific fields - i.e. chemistry, electrochemistry, physical chemistry, rheology - the development of new materials requires a multi-disciplinary approach. The huge variety of macromolecular structure, as the opportunity to incorporate the ionic function onto the macromolecular backbone, will allow many draw-backs related to the use of liquid electrolytes to be overcame. (authors)

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

    KAUST Repository

    Seo, Jeongsuk

    2013-06-06

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

  2. 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.

  3. Platinum and palladium nano-structured catalysts for polymer electrolyte fuel cells and direct methanol fuel cells.

    Science.gov (United States)

    Long, Nguyen Viet; Thi, Cao Minh; Yong, Yang; Nogami, Masayuki; Ohtaki, Michitaka

    2013-07-01

    In this review, we present the synthesis and characterization of Pt, Pd, Pt based bimetallic and multi-metallic nanoparticles with mixture, alloy and core-shell structure for nano-catalysis, energy conversion, and fuel cells. Here, Pt and Pd nanoparticles with modified nanostructures can be controllably synthesized via chemistry and physics for their uses as electro-catalysts. The cheap base metal catalysts can be studied in the relationship of crystal structure, size, morphology, shape, and composition for new catalysts with low cost. Thus, Pt based alloy and core-shell catalysts can be prepared with the thin Pt and Pt-Pd shell, which are proposed in low and high temperature proton exchange membrane fuel cells (PEMFCs), and direct methanol fuel cells (DMFCs). We also present the survey of the preparation of Pt and Pd based catalysts for the better catalytic activity, high durability, and stability. The structural transformations, quantum-size effects, and characterization of Pt and Pd based catalysts in the size ranges of 30 nm (1-30 nm) are presented in electro-catalysis. In the size range of 10 nm (1-10 nm), the pure Pt catalyst shows very large surface area for electro-catalysis. To achieve homogeneous size distribution, the shaped synthesis of the polyhedral Pt nanoparticles is presented. The new concept of shaping specific shapes and morphologies in the entire nano-scale from nano to micro, such as polyhedral, cube, octahedra, tetrahedra, bar, rod, and others of the nanoparticles is proposed, especially for noble and cheap metals. The uniform Pt based nanosystems of surface structure, internal structure, shape, and morphology in the nanosized ranges are very crucial to next fuel cells. Finally, the modifications of Pt and Pd based catalysts of alloy, core-shell, and mixture structures lead to find high catalytic activity, durability, and stability for nano-catalysis, energy conversion, fuel cells, especially the next large-scale commercialization of next

  4. 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.

  5. 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)

  6. 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.

  7. Collection of summaries of polymer electrolyte fuel cell research and development reports presented at fiscal 2000 meeting; 2000 nendo kotai kobunshigata nenryo denchi kenkyu kaihatsu seika hokokukai yoshishu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-08

    Contained in this book are the summaries of 26 essays presented at an achievement reporting conference on polymer electrolyte fuel cell (PEFC) research and development held in Tokyo on March 8, 2000. In the development of high-efficiency energy systems for transportation and residential/commercial sectors, 6 essays are summarized, involving ion exchange membranes, normal pressure operation type several kW class power source systems for home use, and so forth. For the practical application of high-efficiency fuel cell systems, 12 essays are summarized, involving technologies of PEFC low cost electrodes, PEFC module manufacturing, hydrogen separation type reforming, PEFC system manufacturing, and so forth. In relation to the establishment of technologies for a fuel cell popularization infrastructure and development of key technologies for high-efficiency fuel cells, 2 essays are summarized, involving the construction of a popularization infrastructure and development of evaluation test equipment, and the like, for automotive fuel cells. In relation to the development of key technologies and verification thereof for the practical application of fuel cells, 6 essays are summarized, covering the research and development of hydrogen producing liquid fuels and hydrogen absorbing alloys. (NEDO)

  8. 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

  9. Measurement and modelling of local phenomena in polymer electrolyte fuel cells; Messung und Modellierung lokaler Phaenomene in Polymer-Elektrolyt-Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Eckl, R.

    2007-05-15

    Within the scope of this thesis, a new method for in situ current distribution measurement based on printed circuit board technology is developed and applied to polymer electrolyte fuel cells. Using the finite element method, the accuracy of this new approach is compared to conventional techniques and an estimate of the maximum uncertainty of measurement due to lateral currents is given. The effects of variable operating parameters on local electrochemical performance are studied by stationary and dynamic testing of laboratory cells with 100 cm{sup 2} active area. Based on experimental results, load conditions on the anode side are modelled and characteristic water management issues are analysed with the aid of computational fluid dynamics (CFD) simulations. (orig.)

  10. 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.

  11. Experimental study of cell reversal of a high temperature polymer electrolyte membrane fuel cell caused by H2 starvation

    DEFF Research Database (Denmark)

    Zhou, Fan; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2015-01-01

    Operation under fuel starvation has been proved to be harmful to the fuel cell by causing severe and irreversible degradation. To characterize the behaviors of the high temperature PEM fuel cell under fuel starvation conditions, the cell voltage and local current density is measured simultaneously...... under different H2 stoichiometries below 1.0 and at different current loads. The experimental results show that the cell voltage decreases promptly when the H2 stoichiometry decreases to below 1.0. Negative cell voltage can be observed which indicates cell reversal. The local current density starts...... to diverge when the cell voltage decreases. In the H2 upstream regions the current densities show an increasing trend, while those in the H2 downstream regions show a decreasing trend. Consequently, the current density distribution becomes very uneven. The current density is the highest in the upstream...

  12. 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

  13. A tri-generation system based on polymer electrolyte fuel cell and desiccant wheel – Part A: Fuel cell system modelling and partial load analysis

    International Nuclear Information System (INIS)

    Najafi, Behzad; De Antonellis, Stefano; Intini, Manuel; Zago, Matteo; Rinaldi, Fabio; Casalegno, Andrea

    2015-01-01

    Highlights: • A mathematical model for a PEMFC based cogeneration system is developed. • Developed model is validated using the available experimental data. • Performance of the plant at full load conditions is investigated. • Performance indices while applying two different modifications are determined. • System’s performance with and without modifications at partial loads is investigated. - Abstract: Polymer Electrolyte Membrane Fuel Cell (PEMFC) based systems have recently received increasing attention as a viable alternative for meeting the residential electrical and thermal demands. However, as the intermittent demand profiles of a building can only be addressed by a tri-generative unit which can operate at partial loads, the variation of performance of the system at partial loads might affect its corresponding potential benefits significantly. Nonetheless, no previous study has been carried out on assessing the performance of this type of tri-generative systems in such conditions. The present paper is the first of a two part study dedicated to the investigation of the performance of a tri-generative system in which a PEMFC based system is coupled with a desiccant wheel unit. This study is focused on evaluating the performance of the PEMFC subsystem while operating at partial loads. Accordingly, a detailed mathematical model of the fuel cell subsystem is first developed and validated using the experimental data obtained from the plant’s and the fuel cell stack’s manufacturer. Next, in order to increase the performance of the plant, two modifications have been proposed and the resulting performance at partial load have been determined. The obtained results demonstrate that applying both modifications results in increasing the electrical efficiency of the plant by 5.5%. It is also shown that, while operating at partial loads, the electrical efficiency of the plant does not significantly change; the fact which corresponds to the trade-off between

  14. 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.

  15. 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

  16. 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...

  17. 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.

  18. 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.

  19. 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)

  20. Numerical simulations of a full-scale polymer electrolyte fuel cell with analysing systematic performance in an automotive application

    International Nuclear Information System (INIS)

    Park, Heesung

    2015-01-01

    Highlights: • A 3-D full-scale fuel cell performance is numerically simulated. • Generated and consumed power in the system is affected by operating condition. • Systematic analysis predicts the net power of conceptual PEFC stack. - Abstract: In fuel cell powered electric vehicles, the net power efficiency is a critical factor in terms of fuel economy and commercialization. Although the fuel cell stack produces enough power to drive the vehicles, the transferred power to the power train could be significantly reduced due to the power consumption to operate the system components of air blower and cooling module. Thus the systematic analysis on the operating condition of the fuel cell stack is essential to predict the net power generation. In this paper numerical simulation is conducted to characterize the fuel cell performance under various operating conditions. Three dimensional and full-scale fuel cell of the active area of 355 cm 2 is numerically modelled with 47.3 million grids to capture the complexities of the fluid dynamics, heat transfer and electrochemical reactions. The proposed numerical model requires large computational time and cost, however, it can be powerful to reasonably predict the fuel cell system performance at the early stage of conceptual design without requiring prototypes. Based on the model, it has been shown that the net power is reduced down to 90% of the gross power due to the power consumption of air blower and cooling module

  1. 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.

  2. 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)

  3. Analysis of the water balance of polymer electrolyte membrane fuel cells; Untersuchung zum Wasserhaushalt von Polymerelektrolytmembran-Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Hakenjos, A.

    2006-09-14

    Within this thesis, instruments for the localised characterisation of fuel cells and fuel cell stacks have been created. The simultaneous multi-channel impedance spectroscopy was implemented and applied to fuel cells for the first time. A measurement device has been developed that can be used to simultaneously apply various localised measurement methods to fuel cells during operation. Within this work, mainly current density and localized impedance measurements were used. Additionally, the temperature distribution of the active fuel cell area was determined and the water condensation was visualised. Several fuel cells have been developed, constructed and assembled to carry out localised characterisation. An algorithm has been developed to evaluate impedance spectra that separate the processes in the fuel cell according to their different time constants. This algorithm is based on a system of physical model equations that provide time- and location-dependent descriptions of the different processes in the cell. This allows the quantitive extraction of physical parameters from the impedance spectroscopy results. To perform localised simulation, a three-dimensional, two-phase, stationary model was adopted cell. A simple one-dimensional fuel cell geometry was used to demonstrate that the three-dimensional model reliably describes the processes under various operation conditions. The model validation was also successfully carried out for various complex fuel cell geometries. With the localised characterisation methods, air flow field geometries of fuel cells were successfully analysed. It could be explained how the microporous coating of the diffusion layer influences the current density distribution. The water balance of a number of different gas flow geometries was successfully characterised. As a result, an optimised flow field design with a double meander has been developed. The water content has been improved so that the efficiency is increased, and the current

  4. 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.)

  5. 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

  6. 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.

  7. 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

  8. Deoxyribonucleic acid directed metallization of platinum nanoparticles on graphite nanofibers as a durable oxygen reduction catalyst for polymer electrolyte fuel cells

    Science.gov (United States)

    Peera, S. Gouse; Sahu, A. K.; Arunchander, A.; Nath, Krishna; Bhat, S. D.

    2015-11-01

    Effective surface functionalization to the hydrophobic graphite nanofibers (GNF) is performed with the biomolecule, namely deoxy-ribo-nucleic-acid (DNA) via π-π interactions. Pt nanoparticles are impregnated on GNF-DNA composite by ethylene glycol reduction method (Pt/GNF-DNA) and its effect on electro catalytic activity for oxygen reduction reaction (ORR) is systemically studied. Excellent dispersion of Pt nanoparticles over GNF-DNA surfaces with no evidence on particle aggregation is a remarkable achievement in this study. This result in higher electro chemical surface area of the catalyst, enhanced ORR behavior with significant enhancement in mass activity. The catalyst is validated in H2-O2 polymer electrolyte fuel cell (PEFC) and a peak power density of 675 mW cm-2 is achieved at a load current density of 1320 mA cm-2 with a minimal catalyst loading of 0.1 mg cm-2 at a cell temperature of 70 °C and 2 bar absolute pressure. Repeated potential cycling up to 10000 cycles in acidic media is also performed for this catalyst and found excellent stability with only 60 mV drop in the ORR half wave potential. The superior behavior of Pt/GNF-DNA catalyst is credited to the robust fibrous structure of GNF and its effective surface functionalization process via π-π interaction.

  9. 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.

  10. 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.

  11. A review of cell-scale multiphase flow modeling, including water management, in polymer electrolyte fuel cells

    International Nuclear Information System (INIS)

    Andersson, M.; Beale, S.B.; Espinoza, M.; Wu, Z.; Lehnert, W.

    2016-01-01

    Highlights: • The transport expressions inside PEFC GDLs are developed to describe significantly different systems. • Insight into the fundamental processes of liquid water evolution and transport in the GDL and GC is still lacking. • One important feature is the possibility to track the front between the liquid and the gas phases. • The two phase micro channels pressure drop correlations may not be applicable for GCs since one wall being porous. - Abstract: The PEFC has emerged as the most viable fuel cell type for automotive and some portable applications, and also has potential back-up power unit applications due to its low operating temperature, comparative simplicity of construction, high power density, and ease of operation. In spite of tremendous scientific advances, as well as engineering progress over the last few decades, the commercialization of PEFCs remains unrealized, owing primarily to economic viability associated with the high prices of materials and components and technical problems relating primarily to water management. The difficulty in addressing the water management issues lies mostly in the two-phase multi-component flow involving phase-change in porous media, coupled heat and mass transfer, interactions between the porous layers and gas channel (GC) and the complex relationship between water content and cell performance. Due to the low temperature of operation, water generated by the electrochemical reactions often condenses into liquid form, potentially flooding the gas diffusion layer (GDL), GC or other components. Insight into the fundamental processes of liquid water evolution and transport is still lacking, preventing further enhanced PEFC development. The aim of this paper is to give a comprehensive introduction to PEFC modeling inside GCs and GDLs, with a focus on two-phase flow and related phase-change and transport processes. Relevant momentum, mass and heat transport processes are introduced and the microstructural effects

  12. 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.

  13. Nano-nitride cathode catalysts of Ti, Ta, and Nb for polymer electrolyte fuel cells: Temperature-programmed desorption investigation of molecularly adsorbed oxygen at low temperature

    KAUST Repository

    Ohnishi, Ryohji

    2013-01-10

    TiN, NbN, TaN, and Ta3N5 nanoparticles synthesized using mesoporous graphitic (mpg)-C3N4 templates were investigated for the oxygen reduction reaction (ORR) as cathode catalysts for polymer electrolyte fuel cells. The temperature-programmed desorption (TPD) of molecularly adsorbed O2 at 120-170 K from these nanoparticles was examined, and the resulting amount and temperature of desorption were key factors determining the ORR activity. The size-dependent TiN nanoparticles (5-8 and 100 nm) were then examined. With decreasing particle size, the density of molecularly adsorbed O2 per unit of surface area increased, indicating that a decrease in particle size increases the number of active sites. It is hard to determine the electrochemical active surface area for nonmetal electrocatalysts (such as oxides or nitrides), because of the absence of proton adsorption/desorption peaks in the voltammograms. In this study, O2-TPD for molecularly adsorbed O2 at low temperature demonstrated that the amount and strength of adsorbed O2 were key factors determining the ORR activity. The properties of molecularly adsorbed O2 on cathode catalysts are discussed against the ORR activity. © 2012 American Chemical Society.

  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. 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.

  16. 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.

  17. 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.

  18. 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)

  19. 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.

  20. 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...

  1. A trigeneration system based on polymer electrolyte fuel cell and desiccant wheel – Part B: Overall system design and energy performance analysis

    International Nuclear Information System (INIS)

    Intini, M.; De Antonellis, S.; Joppolo, C.M.; Casalegno, A.

    2015-01-01

    Highlights: • Seasonal simulation of a trigeneration system for building air-conditioning. • Effects of technical constraints on trigeneration system power consumption. • Optimal PEMFC unit size for maximizing trigeneration primary energy savings. - Abstract: This paper represents the second part of a major work focusing on a trigeneration system integrating a low temperature polymer electrolyte fuel cell (PEMFC) and a desiccant wheel-based air handling unit. Low temperature PEMFC systems have a significant potential in combined heating, cooling and power applications. However cogenerated heat temperature is relatively low (up to 65–70 °C), resulting in low efficiency of the cooling process, and the fuel processor is far from being flexible, hindering the operation of the system at low load conditions. Therefore a trigeneration system based on PEMFC should be carefully designed through accurate simulation tools. In the current paper a detailed analysis of the energy performance of the trigenerative system is provided, taking into account constraints of real applications, such as PEMFC part load behavior, desiccant wheel effectiveness, heat storage losses and air handling unit electrical consumptions. The methodology adopted to model system components is deeply described. Energy simulations are performed on yearly basis with variable building air conditioning loads and climate conditions, in order to investigate the optimal trigenerative unit size. A sensitivity analysis on crucial design parameters is provided. It is shown that constrains of actual applications have relevant effects on system energy consumption, which is significantly far from expected values based on a simplified analysis. Primary energy savings can be positive in winter time if the ratio of PEMFC heating capacity to air conditioning peak heating load is close to 0.15. Instead on yearly basis primary energy savings cannot be achieved with present components performance. Positive savings

  2. 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.

  3. Morphological features of electrodeposited Pt nanoparticles and its application as anode catalysts in polymer electrolyte formic acid fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Hongrae; Joo, Jiyong; Kwon, Youngkook [Electrochemical Reaction and Technology Laboratory (ERTL), Department of Environmental Science and Engineering, GIST, Gwangju 500-712 (Korea); Uhm, Sunghyun [Ertl Center for Electrochemistry and Catalysis, GIST, Gwangju 500-712 (Korea); Lee, Jaeyoung [Electrochemical Reaction and Technology Laboratory (ERTL), Department of Environmental Science and Engineering, GIST, Gwangju 500-712 (Korea); Ertl Center for Electrochemistry and Catalysis, GIST, Gwangju 500-712 (Korea)

    2010-09-15

    Electrodeposited Pt nanoparticles on carbon substrate show various morphologies depending on the applied potentials. Dendritic, pyramidal, cauliflower-like, and hemi-spherical morphologies of Pt are formed at potential ranges between -0.2 and 0.3 V (vs. Ag/AgCl) and its particle sizes are distributed from 8 to 26 nm. Dendritic bulky particles over 20 nm are formed at an applied potential of -0.2 V, while low deposition potential of 0.2 V causes dense hemi-spherical structure of Pt less than 10 nm. The influence of different Pt shapes on an electrocatalytic oxidation of formic acid is represented. Consequently, homogeneous distribution of Pt nanoparticles with average particle of ca. 14 nm on carbon paper results in a high surface to volume ratio and the better power performance in a fuel cell application. (author)

  4. 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.

  5. 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

  6. 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.

  7. Nanotechnology convergence and modeling paradigm of sustainable energy system using polymer electrolyte membrane fuel cell as a benchmark example

    International Nuclear Information System (INIS)

    Chung, Pil Seung; So, Dae Sup; Biegler, Lorenz T.; Jhon, Myung S.

    2012-01-01

    Developments in nanotechnology have led to innovative progress and converging technologies in engineering and science. These demand novel methodologies that enable efficient communications from the nanoscale all the way to decision-making criteria for actual production systems. In this paper, we discuss the convergence of nanotechnology and novel multi-scale modeling paradigms by using the fuel cell system as a benchmark example. This approach includes complex multi-phenomena at different time and length scales along with the introduction of an optimization framework for application-driven nanotechnology research trends. The modeling paradigm introduced here covers the novel holistic integration from atomistic/molecular phenomena to meso/continuum scales. System optimization is also discussed with respect to the reduced order parameters for a coarse-graining procedure in multi-scale model integration as well as system design. The development of a hierarchical multi-scale paradigm consolidates the theoretical analysis and enables large-scale decision-making of process level design, based on first-principles, and therefore promotes the convergence of nanotechnology to sustainable energy technologies.

  8. Nanotechnology convergence and modeling paradigm of sustainable energy system using polymer electrolyte membrane fuel cell as a benchmark example

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Pil Seung; So, Dae Sup; Biegler, Lorenz T.; Jhon, Myung S., E-mail: mj3a@andrew.cmu.edu [Carnegie Mellon University, Department of Chemical Engineering (United States)

    2012-08-15

    Developments in nanotechnology have led to innovative progress and converging technologies in engineering and science. These demand novel methodologies that enable efficient communications from the nanoscale all the way to decision-making criteria for actual production systems. In this paper, we discuss the convergence of nanotechnology and novel multi-scale modeling paradigms by using the fuel cell system as a benchmark example. This approach includes complex multi-phenomena at different time and length scales along with the introduction of an optimization framework for application-driven nanotechnology research trends. The modeling paradigm introduced here covers the novel holistic integration from atomistic/molecular phenomena to meso/continuum scales. System optimization is also discussed with respect to the reduced order parameters for a coarse-graining procedure in multi-scale model integration as well as system design. The development of a hierarchical multi-scale paradigm consolidates the theoretical analysis and enables large-scale decision-making of process level design, based on first-principles, and therefore promotes the convergence of nanotechnology to sustainable energy technologies.

  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. 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.

  11. Synthesis, characterization and electrochemical studies of Pt- W/C catalyst for polymer electrolyte membrane fuel cells

    International Nuclear Information System (INIS)

    Ahmed, R.; Shahid, S.; Ansari, M. S.

    2013-01-01

    Pt-W/C catalyst was synthesized by slow reduction of platinum and tungsten solutions in the desired ratio with subsequent deposition on the Vulcan carbon already added to the solution. Crystallite size of catalyst was about 9 nm and its density, cell volume, d-spacing and lattice parameter were also calculated. EDX analysis of the catalyst was also done. Electrochemical surface area of the catalyst was determined by cyclic voltammetry (CV). CV of the catalyst was done both in acidic and basic media to find out the peak potential, peak current, specific activity and mass activity of the catalyst. Peak potential versus scan rate plots showed that the electro oxidation of methanol is an irreversible process. Tafel equation was used to plot polarization curves to find out the exchange current density. Higher values of exchange current indicate better catalysts. Specific activities of the catalyst were determined in acidic and basic media and it was found that the specific activity in basic media increased substantially as compared to acidic media. The specific activity in acidic media was 83 mA/mg pt whereas in basic media it was 137mA/mg pt which is a substantial increase. Heterogeneous rate constant in acidic media was 6.15 * 10-6 cm/ s and in basic media it was 4.92 * 10-5 cm/s which is much higher in basic media. In this binary catalyst addition of tungsten has increased the catalytic activity but it is non-noble metal thus will decrease the cost. Stability studies of the catalyst were done upto fifty cycles both in acidic and basic media and was found quite stable in both the media. (author)

  12. Synthesis, characterization and electrochemical studies of Pt-W/C catalyst for polymer electrolyte membrane fuel cells

    International Nuclear Information System (INIS)

    Ahmed, Riaz; Shahid, Saliha; Ansari, Muhammad Shahid

    2014-01-01

    Pt-W/C catalyst was synthesized by slow reduction of platinum and tungsten solutions in the desired ratio with subsequent deposition on the Vulcan carbon already added to the solution. Crystallite size of catalyst was about 9 nm and its density, cell volume, d-spacing and lattice parameter were also calculated. EDX analysis of the catalyst was also done. Electrochemical surface area of the catalyst was determined by cyclic voltammetry (CV). CV of the catalyst was done both in acidic and basic media to find out the peak potential, peak current, specific activity and mass activity of the catalyst. Peak potential versus scan rate plots showed that the electro oxidation of methanol is an irreversible process. Tafel equation was used to plot polarization curves to find out the exchange current density. Higher values of exchange current indicate better catalysts. Specific activities of the catalyst were determined in acidic and basic media and it was found that the specific activity in basic media increased substantially as compared to acidic media. The specific activity in acidic media was 83 mA/mg pt whereas in basic media it was 137mA/mg pt which is a substantial increase. Heterogeneous rate constant in acidic media was 6.15 x 10 −6 cm/ s and in basic media it was 4.92 x 10 −5 cm/s which is much higher in basic media. In this binary catalyst addition of tungsten has increased the catalytic activity but it is non-noble metal thus will decrease the cost. Stability studies of the catalyst were done upto fifty cycles both in acidic and basic media and was found quite stable in both the media

  13. Polymer electrolyte fuel cell durability

    National Research Council Canada - National Science Library

    Büchi, Felix N; Inaba, Minoru; Schmidt, Thomas J

    2009-01-01

    ... fundamental performance stability requirements. The apparent answer is that testing of the power system under fully realistic operation conditions was one prerequisite for revealing the nature and extent of some key modes of PEFC stack failure. Such modes of failure were not exposed to a similar degree, or not at all, in earlier tests of PEFC stac...

  14. 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.

  15. 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].

  16. 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.

  17. 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.

  18. Experimental investigation of carbon monoxide poisoning effect on a PBI/H3PO4 high temperature polymer electrolyte membrane fuel cell

    DEFF Research Database (Denmark)

    Zhou, Fan; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2015-01-01

    humidity level reduced the cell performance loss caused by CO poisoning. When the fuel cell was operated with pure H2, the cell performance was not significantly affect by the change in anode dew point temperature in the range of room temperature and 60 °C. CO2 in anode stream resulted in slight decrease...

  19. Quantitative and qualitative investigation of the fuel utilization and introducing a novel calculation idea based on transfer phenomena in a polymer electrolyte membrane (PEM) fuel cell

    International Nuclear Information System (INIS)

    Yousefkhani, M. Baghban; Ghadamian, H.; Massoudi, A.; Aminy, M.

    2017-01-01

    Highlights: • Investigation of fuel utilization in PEMFC within transfer phenomenon approach. • The main defect of the theoretical calculation of U_F depends on Nernst equation. • U_F has a differential nature so it is employed to do theoretical calculation. - Abstract: In this study, fuel utilization (U_F) of a PEMFC have been investigated within transfer phenomenon approach. Description of the U_F and fuel consumption measurement is the main factor to obtain the U_F. The differences between the experimental study and theoretical calculations results in the previous research articles reveal the available theoretical equations should be studied more based on the fundamental affairs of the U_F. Hence, there is a substantial issue that the U_F description satisfies the principles, and then it can be validated by the experimental results. The results of this study indicate that the U_F and power grew by 1.1% and 1%, respectively, based on one degree increased temperature. In addition, for every 1 kPa pressure increment, U_F improved considerably by 0.25% and 0.173% in the 40 °C and 80 °C, respectively. Furthermore, in the constant temperature, the power improved by 22% based on one atmospheric growth of the pressure. Results of this research show that the U_F has a differential nature, therefore differential equations will be employed to do an accurate theoretical calculation. Accordingly, it seems that the main defect of the theoretical calculation depends on Nernst equation that can be modified by a differential nature coefficient.

  20. Combined novel methods for the determination of the humidification conditions of polymer electrolyte fuel cells; Kombination neuer Methoden zur Bestimmung des Wasserhaushaltes von Polymer-Elektrolyt-Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Robert Martin

    2011-05-02

    The water management is one of the key factors for the performance of a low temperature PEM fuel cell. With respect to the optimization of the fuel cell operation it is important to detect and differentiate water in the membrane, in the gas diffusion layer (GDL) and excess water in the flow field channel. The water content of each component influences the performance in different ways and adapted operation modes have to be kept. This work entitled 'Combined novel methods for the determination of the humidification conditions of PEM fuel cells' provides techniques and guidelines for fuel cell operation and will conclude in a straightforward control and operation strategy. Based on a combination of electrochemical impedance spectroscopy (EIS), locally resolved current distribution measurements and neutron radiography an informative basis for the determination of the water content of an operating PEM fuel cell is created. Special attention has been paid to the reproducibility and comparability in order to set up a consistent investigation and control strategy. (orig.)

  1. Degradation of H3PO4/PBI High Temperature Polymer Electrolyte Membrane Fuel Cell under Stressed Operating Conditions

    DEFF Research Database (Denmark)

    Zhou, Fan

    performance loss caused by CO poisoning can be alleviated by the presence of water vapor. The CO oxidation via the water gas shift reaction is the main reason for the mitigated CO poisoning with the presence of water vapor. Meanwhile, the CO poisoning can deteriorate with the presence of CO2, although the CO2...... for HT-PEM fuel cell based micro-CHP units for households, the daily startup/shutdown operation is necessary. Moreover, the faults in the H2 supply system or in controlling the reformer can cause the H2 starvation of the HT-PEM fuel cell. The effects of these operating conditions to the degradation...... results in the degradation in cell performance of the HT-PEM fuel cell by increasing the charge transfer resistance and mass transfer resistance. The CO with volume fraction of 1% – 3% can cause significant performance loss to the HT-PEM fuel cell at the operating temperature of 150 oC. The cell...

  2. Evaluation of a fuel cell polymer electrolyte with Pt-Sn anode operating with H2, H2-CO mixture, propane and methane

    International Nuclear Information System (INIS)

    Monsalve, Carlos; Hoyos, Bibian

    2005-01-01

    In this work it was tested a proton Exchange membrane fuel cell with a Pt-Sn anode (in a 90:10 ratio) fed with H 2 , a H 2 -CO mixture, propane and methane under a pressure of 10 psi and temperatures of 30, 50 y 70 Celsius degrade. It was found good catalyst tolerance to the CO presence in the hydrogen current, even with catalytic activity to the CO oxidation. For the pure CO, propane and methane cases, the catalytic activity was too low. This results show that the Pt-Sn catalyst it is not appropriated for those fuels.

  3. 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.

  4. Novel techniques of oxygen bleeding for polymer electrolyte fuel cells under impure anode feeding and poisoning condition: A computational study using OpenFOAM®

    International Nuclear Information System (INIS)

    Hafttananian, M.; Ramiar, A.; Ranjbar, A.A.

    2016-01-01

    Highlights: • Oxygen bleeding as a treatment of poisoned fuel cells is simulated. • Oxygen bleeding, depended on impurity concentration, has an optimize range. • Three novel techniques of oxygen bleeding are introduced. • The OBME parameter is introduced to compare oxygen bleeding methods. • Pulsating and sinusoidal methods lead to 2.74 and 1.74 effectiveness, respectively. - Abstract: PEM fuel cells fed by steam methane reformate (SMR) and water gas shift reformate (WGSR) are always subjected to catalyst poisoning due to trace amounts of carbon monoxide in the fuel stream. Air or oxygen bleeding are the most common, cost-effective and easy-to-implement methods of mitigation for such conditions. In the present work, important restrictions of oxygen bleeding and disadvantages of continuous constant O_2 bleeding are introduced. In order to simulating the problem, a mathematical model containing reaction kinetics, governing equations, boundary conditions and constitutive relations are presented and according to these, a comprehensive OpenFOAM transient multicomponent solver having the capability of simulating anode side of PEM fuel cell is developed, introduced and validated with existing experimental data. In addition, three novel methods of oxygen bleeding: namely pulsating, exponential and sinusoidal methods are introduced which are practical for both open-end and dead-end fuel cells. A quantitative criterion, Oxygen Bleeding Method Effectiveness (OBME), is also introduced to attain comparability of novel methods with continuous constant O_2 bleeding as common method. Results showed up to more than 5% increase in recovery ratio accompanied with up to 63% save in oxygen consumption.

  5. Preparation of Carbon-Platinum-Ceria and Carbon-Platinum-Cerium catalysts and its application in Polymer Electrolyte Fuel Cell: Hydrogen, Methanol, and Ethanol

    Science.gov (United States)

    Guzman Blas, Rolando Pedro

    This thesis is focused on fuel cells using hydrogen, methanol and ethanol as fuel. Also, in the method of preparation of catalytic material for the anode: Supercritical Fluid Deposition (SFD) and impregnation method using ethylenediaminetetraacetic acid (EDTA) as a chelating agent. The first part of the thesis describes the general knowledge about Hydrogen Polymer Exchange Membrane Fuel Cell (HPEMFC),Direct Methanol Fuel Cell (DMFC) and Direct Ethanol Fuel Cell (DEFC), as well as the properties of Cerium and CeO2 (Ceria). The second part of the thesis describes the preparation of catalytic material by Supercritical Fluid Deposition (SFD). SFD was utilized to deposit Pt and ceria simultaneously onto gas diffusion layers. The Pt-ceria catalyst deposited by SFD exhibited higher methanol oxidation activity compared to the platinum catalyst alone. The linear sweep traces of the cathode made for the methanol cross over study indicate that Pt-Ceria/C as the anode catalyst, due to its better activity for methanol, improves the fuel utilization, minimizing the methanol permeation from anode to cathode compartment. The third and fourth parts of the thesis describe the preparation of material catalytic material Carbon-Platinum-Cerium by a simple and cheap impregnation method using EDTA as a chelating agent to form a complex with cerium (III). This preparation method allows the mass production of the material catalysts without additional significant cost. Fuel cell polarization and power curves experiments showed that the Carbon-Platinum-Cerium anode materials exhibited better catalytic activity than the only Vulcan-Pt catalysts for DMFC, DEFC and HPEMFC. In the case of Vulcan-20%Pt-5%w Cerium, this material exhibits better catalytic activity than the Vulcan-20%Pt in DMFC. In the case of Vulcan-40% Pt-doped Cerium, this material exhibits better catalytic activity than the Vulcan-40% Pt in DMFC, DEFC and HPEMFC. Finally, I propose a theory that explains the reason why the

  6. Design and test of a 5 kWe high-temperature polymer electrolyte fuel cell system operated with diesel and kerosene

    International Nuclear Information System (INIS)

    Samsun, Remzi Can; Pasel, Joachim; Janßen, Holger; Lehnert, Werner; Peters, Ralf; Stolten, Detlef

    2014-01-01

    Highlights: • A fuel cell system for application as auxiliary power unit was developed. • Key components were a high-temperature PEFC stack and an autothermal reformer. • The system was tested with GTL kerosene, BTL diesel and premium diesel fuel. • The target electrical power of 5 kW was achieved with all fuels used. • Self-sustaining system operation was demonstrated with the integrated system design. - Abstract: A high-temperature PEFC system, developed with the aim of delivering 5 kW electrical power from the chemical energy stored in diesel and kerosene fuels for application as an auxiliary power unit, was simulated and tested. The key components of the system were an autothermal reformer, a water–gas shift reactor, a catalytic burner, and the HT-PEFC stack. The targeted power level of 5 kW was achieved using different fuels, namely GTL kerosene, BTL diesel and premium diesel. Using an integrated system approach, operation without external heat input was demonstrated. The overall analysis showed slight but non-continuous performance loss for 250 h operation time

  7. 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)

  8. 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)

  9. Investigation of the role of the micro-porous layer in polymer electrolyte fuel cells with hydrogen deuterium contrast neutron radiography.

    Science.gov (United States)

    Cho, Kyu Taek; Mench, Matthew M

    2012-03-28

    In this study, the high resolution hydrogen-deuterium contrast radiography method was applied to elucidate the impact of the micro-porous layer (MPL) on water distribution in the porous fuel cell media. At the steady state, deuterium replaced hydrogen in the anode stream, and the large difference in neutron attenuation of the D(2)O produced at the cathode was used to track the produced water. It was found that the water content peaked in the cathode-side diffusion media (DM) for the cell without MPL, but with an MPL on the anode and cathode DM, the peak water amount was pushed toward the anode, resulting in a relatively flattened water profile through components and demonstrating a liquid barrier effect. Additionally, the dynamic water behavior in diffusion media was analyzed to understand the effect of a MPL and operating conditions. The water content in the DM changed with applied current, although there is a significant amount of residual liquid content that does not appear to be part of capillary channels. The effect of the MPL on irreducible saturation in DM and cell performance was also investigated.

  10. 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...

  11. 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.

  12. 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

  13. 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 ...

  14. 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)

  15. Niobium-based catalysts prepared by reactive radio-frequency magnetron sputtering and arc plasma methods as non-noble metal cathode catalysts for polymer electrolyte fuel cells

    International Nuclear Information System (INIS)

    Ohnishi, Ryohji; Katayama, Masao; Takanabe, Kazuhiro; Kubota, Jun; Domen, Kazunari

    2010-01-01

    Two vacuum methods, reactive radio-frequency (RF) magnetron sputtering and arc plasma deposition, were used to prepare niobium-based catalysts for an oxygen reduction reaction (ORR) as non-noble metal cathodes for polymer electrode fuel cells (PEFCs). Thin films with various N and O contents, denoted as NbO x and Nb-O-N, were prepared on glassy carbon plates by RF magnetron sputtering with controlled partial pressures of oxygen and nitrogen. Electrochemical measurements indicated that the introduction of the nitrogen species into the thin film resulted in improved ORR activity compared to the oxide-only film. Using an arc plasma method, niobium was deposited on highly oriented pyrolytic graphite (HOPG) substrates, and the sub-nanoscale surface morphology of the deposited particles was investigated using scanning tunneling microscopy (STM). To prepare practical cathode catalysts, niobium was deposited on carbon black (CB) powders by arc plasma method. STM and transmission electron microscopy observations of samples on HOPG and CB indicated that the prepared catalysts were highly dispersed at the atomic level. The onset potential of oxygen reduction on Nb-O-N/CB was 0.86 V vs. a reversible hydrogen electrode, and the apparent current density was drastically improved by the introduction of nitrogen.

  16. 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

  17. 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.

  18. Microstructure-property relationships in a gas diffusion layer (GDL) for Polymer Electrolyte Fuel Cells, Part I: effect of compression and anisotropy of dry GDL

    International Nuclear Information System (INIS)

    Holzer, L.; Pecho, O.; Schumacher, J.; Marmet, Ph.; Stenzel, O.; Büchi, F.N.; Lamibrac, A.; Münch, B.

    2017-01-01

    Highlights: • Methods are developed to predict transport properties of dry GDL in PE Fuel Cells. • Diffusivity and Permeability are reliably predicted based on 3D characteristics. • Predictions based on 3D microstructure match well with numerical simulations. • Anisotropy is due to in- and through-plane variation of tortuosity and hydraulic rad. • The methods can be used to predict relative permeability and diffusivity in wet GDL. - Abstract: New quantitative relationships are established between effective properties (gas diffusivity, permeability and electrical conductivity) for a dry GDL (25 BA) from SGL Carbon with the corresponding microstructure characteristics from 3D analysis. These microstructure characteristics include phase volume fractions, geodesic tortuosity, constrictivity and hydraulic radius. The latter two parameters include information from two different size distribution curves for bulges (continuous PSD) and for bottlenecks (MIP-PSD). X-ray tomographic microscopy is performed for GDL at different compression levels and the micro-macro-relationships are then established for the in-plane and through-plane directions. The predicted properties based on these relationships are compared with numerical transport simulations, which give very similar results and which can be summarized as follows: Gas diffusivity is higher in the in-plane than in the through-plane direction. Its variation with compression is mainly related to changes of porosity and geodesic tortuosity. Permeability is dominated by variations in hydraulic radius. Through-plane permeability is slightly higher than in-plane. Anisotropy of electrical conductivity is controlled by tortuosity, which is higher for the through-plane direction. A table with new quantitative relationships is provided, which are considered to be more accurate and precise than older descriptions (e.g. Carman-Kozeny, Bruggeman), because they are based on detailed topological information from 3D analysis

  19. Rambutan-like CNT-Al2O3 scaffolds for high-performance cathode catalyst layers of polymer electrolyte fuel cells

    Science.gov (United States)

    Chang, KwangHyun; Cho, Seonghun; Lim, Eun Ja; Park, Seok-Hee; Yim, Sung-Dae

    2018-03-01

    Rambutan-like CNT-Al2O3 scaffolds are introduced as a potential candidate for CNT-based catalyst supports to overcome the CNT issues, such as the easy bundling in catalyst ink and the poor pore structure of the CNT-based catalyst layers, and to achieve high MEA performance in PEFCs. Non-porous α-phase Al2O3 balls are introduced to enable the growth of multiwalled CNTs, and Pt nanoparticles are loaded onto the CNT surfaces. In a half-cell, the Pt/CNT-Al2O3 catalyst shows much higher durability than those of a commercial Pt/C catalyst even though it shows lower oxygen reduction reaction (ORR) activity than Pt/C. After using the decal process for MEA formation, the Pt/CNT-Al2O3 shows comparable initial performance characteristics to Pt/C, overcoming the lower ORR activity, mainly due to the facile oxygen transport in the cathode catalyst layers fabricated with the CNT-Al2O3 scaffolds. The Pt/CNT-Al2O3 also exhibits much higher durability against carbon corrosion than Pt/C owing to the durable characteristics of CNTs. Systematic analysis of single cell performance for both initial and after degradation is provided to understand the origin of the high initial performance and durable behavior of Pt/CNT-Al2O3-based catalyst layers. This will provide insights into the design of electrocatalysts for high-performance MEAs in PEFCs.

  20. Evaporative cooling in polymer electrolyte fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Shimotori, S; Sonai, A [Toshiba Corp. Tokyo (Japan)

    1996-06-05

    The concept of the evaporative cooling for the internally humidified PEFC was confirmed by the experiment. The evaporative cooling rates at the anode and the cathode were mastered under the various temperatures and air utilizations. At a high temperature the proportion of the evaporative cooling rate to the heat generation rate got higher, the possibility of the evaporative cooling was demonstrated. 2 refs., 7 figs., 1 tab.

  1. 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

  2. Heat balance of a molten carbonate fuel cell production hydrogen for a polymer electrolyte fuel cell-CoCell; Waermehaushalt einer Karbonat-Brennstoffzelle zur Wasserstoffherstellung fuer eine Polymerelektrolyt-Brennstoffzelle

    Energy Technology Data Exchange (ETDEWEB)

    Adamek, L.

    2006-10-17

    Molten carbonate fuel cells (MCFC) are being used in decentralised power plants, as they can reform hydrocarbon bound fuels internally, e.g. natural gas with a energy density of 10 kWh/m{sup 3} at standard conditions, and the efficiency of this mode of operation is around 50 %. However in comparison to other fuel cell systems the power density is only 5 kW/m{sup 3}. The power density of a polymerelectrolyte fuel cell (PEFC) is much higher (50 kW/m{sup 3}). These systems can be run with an efficiency of 50 %, too. Therefore they need hydrogen as a fuel, with an energy density of 2,9 kWh/m{sup 3} at standard conditions. Efficiency decreases to 35 to 40% using Methane as fuel, because of the reforming losses. The power density than is 6 kW/m3 and therefore as high as for a MCFC-system. Acombination of MCFC and PEFC, the so called CoCell, offers the following advantages: - A highly energetic, hydrocarbon based fuel can be used, e.g. Methane. - A high electrical efficiency is achieved. - The power density of this system is higher than for a fuel cell with reformer. In the CoCell the MCFC is working as electricity producing reformer for the PEFC. The off heat of the MCFC is used for reforming, whereby hydrogen is available, being utilised further in the power dense PEFC. The reforming capacity of the MCFC is limited by the internal heat balance. If the endothermic reforming consumes more heat than supplied by the material streams and the fuel cell waste heat, the stack cools down. The performance of such a combined fuel cell system has been evaluated in this thesis using the thermodynamic simulation software Aspen. Calculations reducing the utilisation in the MCFC by various heating techniques showed, that additional heat is supplied most efficiently by increasing the current density of the MCFC. Thereby the stack is heated electrically and the power density of the system is increased by the improved power density of the MCFC. The reduction of the utilisation is achieved

  3. Solid State Polymer Electrolytes for Dye-sensitized Solar Cell

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Introduction Over the past decade,Dye-sensitized solar cells (DSSCs) have been intensively investigated as potential alternatives to conventional inorganic photovoltaic devices due to their low production cost and high energy conversion[1-4]. This type of solar cell has achieved an impressive energy conversion efficiency of over 10%,whose electrolyte is a voltaic organic liquid solvent containing iodide/triiodide as redox couple.However,the use of a liquid electrolyte brings difficulties in the practi...

  4. Novelionic Polymer Electrolytes for Dye Sensitized Solar Cell

    Institute of Scientific and Technical Information of China (English)

    Li Wang; Shibi Fang; Yuan Lin

    2005-01-01

    @@ 1Introduction In recent years, dye-sensitized solar cells(DSC) based on nanocrystalline porous TiO2 films have attracted much attention because of their relatively higher efficiency and low cost compared with conventional inorganic photovoltaic devices[1]. This type of solar cell has achieved an impressive photo-to-energy conversion efficiency of over 10% where the electrolyte is volatile organic liquid solvents containing I-/I-3- as redox couple. Because of high volatilities, solvent losses occur during long-term operations, resulting in lowered DSC performances.And leakage of liquid electrolyte also limits the durability of DSC.

  5. FY 2000 report on development of the infrastructure to promote use of fuel cells for automobiles. Development of the infrastructure to spread stationary polymer electrolyte fuel cell (PEFC) systems; 2000 nendo nenryo denchi fukyu kiban seibi seika hokokusho. Teichiyo kotai kobunshigata nenryo denchi no fukyu kiban seibi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Described herein are the results of the FY 2000 studies on development of the infrastructures necessary for introduction and spread of stationary polymer electrolyte fuel cell (PEFC) systems. This project is aimed at establishment of testing and evaluation methods for safety, reliability, performance and so on, and collection of the data, both domestic and foreign, for drafting rules and standardization. The methods are studied to collect the data for the start-up/shut-down operations and rated-load/partial-load operations; establishing the methods for safety evaluation when inert gas purging is dispensed with; and dependence of the cell stack on current, carbon monoxide concentration and cell temperature to establish the basic performance testing methods. The makers are independently developing the stationary PEFC systems, and the data of the selected systems are collected individually as the test systems. The cell stacks also adopt different humidification and cooling methods by makers, and they are tested and their data are collected and analyzed, in order to establish the common testing methods. (NEDO)

  6. 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.

  7. 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}.

  8. 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)

  9. 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.

  10. 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].

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2011-06-01

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

  13. FY 2000 report on the results of development of technology for commercializing high-efficiency fuel cell systems. Development of technology for commercializing high-efficiency fuel cell systems (Development of technology for effective utilization of power produced by polymer electrolyte fuel cell systems); 2000 nendo kokoritsu nenryo denchi system jitsuyoka gijutsu kaihatsu seika hokokusho. Kotai kobunshigata nenryo denchi no shutsuryoku yuko riyo gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    This project is aimed at development of technologies for effective utilization of power produced by polymer electrolyte fuel cell (PEFC) systems and waste heat, to spread cogeneration systems incorporating PEFC systems for residential purposes. Described herein are the FY 2000 results. The program for high-efficiency peripherals for residential PFEC systems attempts use of GaN-FET as the semiconductor device of wide band gap and high breakdown voltage to realize conversion efficiency over 90% by improving inverter efficiency. Two types of the prototype heat recovery systems are developed for the PEFC, one incorporating a latent heat cooling system and the other a water cooling system, to improve heat recovery efficiency and increase heat recovery temperature. The program for technology to fit PEFC output to energy demand develops hot water supply systems provided with a hot water storage function for stable supply of hot water irrespective of the heat recovery conditions, and also with a back-up function with burners. The program also develops the PEFC system of fine load following characteristics, for which pure hydrogen is used as the fuel to allow the system to instantaneously follow fluctuating loads. The program for high-efficiency partial load operation technology studies a 1kW-class residential PEFC cogeneration system incorporating a power storage device for high-efficiency operation at partial loads, where the former operates in a high output mode while the latter absorbs fluctuating loads. (NEDO)

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Achievement report for fiscal 1998. Research and development of polymer electrolyte fuel cell module (Development of 10kW-class transportable power source system of high current density type); 1998 nendo seika hokokusho. Kotai kobunshigata nenryo denchi no kenkyu kaihatsu, kodenryu mitsudogata 10kW kyu kahangata dengen system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    For the development by the end of fiscal 2000 the above-named system which will operate on methanol/air (normal atmospheric pressure) yielding 0.3W/cm{sup 2} or more, efforts are exerted about a high-lamination type PEFC (polymer electrolyte fuel cell) module and a lamination type methanol reformer, this project carried over from fiscal 1997. In relation with the PEFC module, platinum loading was reduced (by 60% from the amount in fiscal 1997) by catalytic layer improvement, cell characteristics were improved, continuous load imposition was performed using a reformed simulation gas, life test was conducted consisting of frequent starts and stops, lamination was built using shaping separators, and a 2kW-class stack was built and evaluated for performance. Next to come is a test run of a 5kW-class stack. In relation with the lamination type methanol, element components were tested. A reformer section and a catalytic combustion section were designed, manufactured, and tested, and a vaporizer section and a CO reduction section were evaluated for performance and life. A 2kW-rate lamination type methanol reformer was designed and built by integrating the said element components, and was subjected to a test run for performance evaluation. (NEDO)

  19. 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.

  20. 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)

  1. Gel polymer electrolyte lithium-ion cells with improved low temperature performance

    Energy Technology Data Exchange (ETDEWEB)

    Smart, M.C.; Ratnakumar, B.V.; Behar, A.; Whitcanack, L.D. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Yu, J.-S. [LG Chem/Research Park, P.O. Box 61Yu Song, Science Town, Daejon (Korea); Alamgir, M. [Compact Power, Inc., 1857 Technology Drive, Troy, MI 48083 (United States)

    2007-03-20

    For a number of NASA's future planetary and terrestrial applications, high energy density rechargeable lithium batteries that can operate at very low temperature are desired. In the pursuit of developing Li-ion batteries with improved low temperature performance, we have also focused on assessing the viability of using gel polymer systems, due to their desirable form factor and enhanced safety characteristics. In the present study we have evaluated three classes of promising liquid low-temperature electrolytes that have been impregnated into gel polymer electrolyte carbon-LiMn{sub 2}O{sub 4}-based Li-ion cells (manufactured by LG Chem. Inc.), consisting of: (a) binary EC + EMC mixtures with very low EC-content (10%), (b) quaternary carbonate mixtures with low EC-content (16-20%), and (c) ternary electrolytes with very low EC-content (10%) and high proportions of ester co-solvents (i.e., 80%). These electrolytes have been compared with a baseline formulation (i.e., 1.0 M LiPF{sub 6} in EC + DEC + DMC (1:1:1%, v/v/v), where EC, ethylene carbonate, DEC, diethyl carbonate, and DMC, dimethyl carbonate). We have performed a number of characterization tests on these cells, including: determining the rate capacity as a function of temperature (with preceding charge at room temperature and also at low temperature), the cycle life performance (both 100% DOD and 30% DOD low earth orbit cycling), the pulse capability, and the impedance characteristics at different temperatures. We have obtained excellent performance at low temperatures with ester-based electrolytes, including the demonstration of >80% of the room temperature capacity at -60 C using a C/20 discharge rate with cells containing 1.0 M LiPF{sub 6} in EC + EMC + MB (1:1:8%, v/v/v) (MB, methyl butyrate) and 1.0 M LiPF{sub 6} in EC + EMC + EB (1:1:8%, v/v/v) (EB, ethyl butyrate) electrolytes. In addition, cells containing the ester-based electrolytes were observed to support 5C pulses at -40 C, while still

  2. 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....

  3. The JPL Direct Methanol Liquid-feed PEM Fuel Cell

    Science.gov (United States)

    Halpert, G.; Surampudi, S.

    1994-01-01

    Recently, there has been a breakthrough in fuel cell technology in the Energy Storage Systems Group at the Jet Propulsion Laboratory with the develpment of a direct methanol, liquid-feed, solid polymer electrolyte membrane (PEM) fuel cell... The methanol liquid-feed, solid polymer electrolyte (PEM) design has numerous system level advantages over the gas-feed design. These include:...

  4. On direct and indirect methanol fuel cells for transportation applications

    Energy Technology Data Exchange (ETDEWEB)

    Gottesfield, S.

    1996-04-01

    Research on direct oxidation methanol fuel cells (DMFCs) and polymer electrolyte fuel cells (PEFCs) is discussed. Systems considered for transportation applications are addressed. The use of platinum/ruthenium anode electrocatalysts and platinum cathode electrocatalysts in polymer electrolyte DMFCs has resulted in significant performance enhancements.

  5. 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)

  6. In situ concentration cartography in the neighborhood of dendrites growing in lithium/polymer-electrolyte/lithium cells

    Energy Technology Data Exchange (ETDEWEB)

    Brissot, C.; Rosso, M.; Chazalviel, J.N.; Lascaud, S.

    1999-12-01

    The authors report on three different in situ and ex situ concentration measurement methods in symmetric lithium/polymer-electrolyte/lithium cells. The results were examined on the basis of a simple calculation of ionic concentration within the electrolyte, in the case where no dendrite is observed, this calculation accounts quantitatively for all experimental results. In the case of dendritic growth, the authors can measure the concentration distribution around the dendrites; this permits correlation of the active parts of the electrodes and of the growing dendrites with local ionic depletion in the vicinity of these active parts.

  7. Commercialization of fuel-cells

    Energy Technology Data Exchange (ETDEWEB)

    Penner, S.S.; Appleby, A.J.; Baker, B.S.; Bates, J.L.; Buss, L.B.; Dollard, W.J.; Farris, P.J.; Gillis, E.A.; Gunsher, J.A.; Khandkar, A.; Krumpelt, M.; O' Sullivan, J.B.; Runte, G.; Savinell, R.F.; Selman, J.R.; Shores, D.A.; Tarman, P.

    1995-03-01

    This report is an abbreviated version of the ''Report of the DOE Advanced Fuel Cell Commercialization Working Group (AFC2WG),'' released January 1995. We describe fuel-cell commercialization for stationary power applications of phosphoric acid, molten carbonate, solid oxide, and polymer electrolyte membrane fuel cells.

  8. The use of poly(vinylpyridine-co-acrylonitrile) in polymer electrolytes for quasi-solid dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Li, Minyu; Feng, Shujing; Fang, Shibi; Xiao, Xurui; Li, Xueping; Zhou, Xiaowen; Lin, Yuan

    2007-01-01

    Poly(vinylpyridine-co-acrylonitrile) (P(VP-co-AN)) was used to form polymer electrolytes for dye-sensitized solar cells (DSSCs). The effects of P(VP-co-AN) on the photovoltaic performances of DSSCs have been investigated with nonaqueous electrolytes containing alkali-iodide and iodine. It was found that the effect of P(VP-co-AN) on V oc closely related to its amount in the electrolyte. Lower amount of P(VP-co-AN) was benefit for the construction of a solar cell containing P(VP-co-AN) with higher energy conversion efficiency. Chemically crosslinking solidification with backbone polymer P(VP-co-AN) amount of 3% fabricated quasi-solid DSSCs with 10% increased conversion efficiencies with relative to that of the initial liquid DSSCs

  9. Electrode of solid state polymer electrolyte type electrochemical cell; Kobunshi kotai denkaisitsugata denki kagaku seru yo denkyo

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, M [Yamanashi, (Japan); Inoue, M [Tanaka Kikinzoku Kogyo, Tokyo (Japan)

    1996-04-12

    The solid state polymer electrolyte type electrochemical cell (PEMFC) has such problem that the gas diffusion from the resin surface to the catalyst surface is prevented when the coating thickness of cation exchange resin on the catalyst particle and the number of micropores which conduct the gas flow in the catalyst layer are reduced. Resultingly, a sufficiently large current cannot be taken out of the cell. This invention solves the problem. The catalyst layer of electrode of PEMFC consists of a mixture of the conductive catalyst carrier coated with cation exchange resin and the conductive carrier coated with fluorinated hydrocarbon polymer. Adding the water repellent material to the electrode in this way improves the air-passing porosity. As for the cation exchange resin, perfluorocarbon sulfonate or perfluorocarbon carboxylate can be used. For the fluorinated hydrocarbon polymer, fluorinated polyethylene is preferably used. 4 figs., 2 tabs.

  10. Report on the results of the FY 1999 R and D of polymer electrolyte fuel cells. Development of the power system technology (Development of high voltage several 10 kW class dispersed generation system); 1999 nendo kotai kobunshigata nenryo denchi no kenkyu kaihatsu seika hokokusho. Hatsuden system gijutsu no kaihatsu (koden'atsugata suju kW kyu bunsan dengen system no kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    The paper described the results of the FY 1999 development of polymer electrolyte fuel cell and several 10 kW class dispersed generation system. The humidification of the cell body is the internal humidification method in which water is directly supplied to cell, which makes the cell life long. The cooling using latent heat of vaporization of the water supplied makes the temperature distribution inside the cell face homogeneous. In the test for long life, the system was stably operated at voltage lowering speed of 11mV/1000h. The optimization of water supply structure in the stack increases the latent heat cooling amount and makes the temperature distribution inside the cell face homogeneous. The reduction of CO concentration in reformed gas is extremely important for improvement of cell performance and long-term stabilization of cell voltage. By the two-stage structure selective oxidation device, the CO concentration at inlet, 5,000 ppm, can be reduced to below 10 ppm at outlet. In the demonstrative experiment on the several 10 kW class dispersed generation system, efforts for reduction in size of structural equipment and package were made, and a possible size of 200*150*180cm was obtained. Based on the chart of 30kW class system flow, the heat material balance was analyzed, and the power generation efficiency of 40% at a.c. sending end and overall efficiency of 80% were confirmed. (NEDO)

  11. Polymer electrolyte fuel cells science, applications, and challenges

    CERN Document Server

    Franco, Alejandro A

    2013-01-01

    This book focuses on the recent research progresses on the fundamentals understanding of the materials degradation phenomena in PEFC, for automotive applications. On a multidisciplinary basis, through contributions of internationally recognized researchers in the field, this book provides a complete and comprehensive critical review on crucial scientific topics related to PEFC materials degradation, and ensures a strong complementary between experimental and theoretical analysis and preparation techniques with several practical applications for both the research and the industry communities.

  12. Tetrazole substituted polymers for high temperature polymer electrolyte fuel cells

    DEFF Research Database (Denmark)

    Henkensmeier, Dirk; My Hanh Duong, Ngoc; Brela, Mateusz

    2015-01-01

    an equilibrium uptake of 0.5 and 4.7 mol PA per mol heterocycle, respectively, indicating that PBI has higher affinity for PA than TZ-PEEN. The highest achieved PA uptake was ca. 110 wt%, resulting in a proton conductivity of 25 mS cm−1 at 160 °C with a low activation energy of about 35 kJ mol−1. In a first HT...

  13. 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

  14. 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.

  15. 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.

  16. 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)

  17. 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

  18. 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.

  19. 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

  20. Improvement of N-phthaloylchitosan based gel polymer electrolyte in dye-sensitized solar cells using a binary salt system.

    Science.gov (United States)

    Yusuf, S N F; Azzahari, A D; Selvanathan, V; Yahya, R; Careem, M A; Arof, A K

    2017-02-10

    A binary salt system utilizing lithium iodide (LiI) as the auxiliary component has been introduced to the N-phthaloylchitosan (PhCh) based gel polymer electrolyte consisting of ethylene carbonate (EC), dimethylformamide (DMF), tetrapropylammonium iodide (TPAI), and iodine (I 2 ) in order to improve the performance of dye-sensitized solar cell (DSSC) with efficiency of 6.36%, photocurrent density, J SC of 17.29mAcm -2 , open circuit voltage, V OC of 0.59V and fill factor, FF of 0.62. This efficiency value is an improvement from the 5.00% performance obtained by the DSSC consisting of only TPAI single salt system. The presence of the LiI in addition to the TPAI improves the charge injection rates and increases the iodide contribution to the total conductivity and both factors contribute to the increase in efficiency of the DSSC. The interaction behavior between polymer-plasticizer-salt was thoroughly investigated using EIS, FTIR spectroscopy and XRD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Modeling of laser cladding with application to fuel cell manufacturing.

    Science.gov (United States)

    2010-01-01

    Polymer electrolyte membrane (PEM) fuel cells have many advantages such as compactness, : lightweight, high power density, low temperature operation and near zero emissions. Although : many research organizations have intensified their efforts toward...

  2. Hydrogen fuel cells for cars and buses

    NARCIS (Netherlands)

    Janssen, L.J.J.

    2007-01-01

    The use of hydrogen fuel cells for cars is strongly promoted by the governments of many countries and by international organizations like the European Community. The electrochem. behavior of the most promising fuel cell (polymer electrolyte membrane fuel cell, PEMFC) is critically discussed, based

  3. 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...

  4. 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.

  5. 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....

  6. Gas-discharge plasma processes for surface modification and conversion of chemical substances. Application for fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, K.; Meyer, D.; Rohland, B.; Heintze, M.; Zahn, R.J.; Hannemann, M.; Meusinger, J.; Ohl, A. [Institute of Non-Thermal Plasma Physics, Greifswald (Germany)]|[Gesellschaft fuer Angewandte Technik mbH Greifswald (Germany)]|[GAPC, Adam Opel AG, IPC, Ruesselsheim (Germany)

    2001-07-01

    The potential of plasma processes towards hydrogen and fuel cell technology will be demonstrated by two examples with preliminary results: 1. plasma modification of polymer electrolyte membranes for direct methanol fuel cells, and 2. plasma supported steam reforming.

  7. 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).

  8. 3-Dimensional Computational Fluid Dynamics Modeling of Solid Oxide Fuel Cell Using Different Fuels

    Science.gov (United States)

    2011-01-01

    major types of fuel cells in practice are listed below: Polymer Electrolyte Membrane Fuel Cell ( PEMFC ) Alkaline Fuel cell (AFC) Phosphoric Acid...Material Operating Temperature (oC) Efficiency (%) PEMFC H2, Methanol, Formic Acid Hydrated Organic Polymer < 90 40-50 AFC Pure H2 Aqueous

  9. 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...

  10. 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)

  11. 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.

  12. A Lithium/Polysulfide Battery with Dual-Working Mode Enabled by Liquid Fuel and Acrylate-Based Gel Polymer Electrolyte.

    Science.gov (United States)

    Liu, Ming; Ren, Yuxun; Zhou, Dong; Jiang, Haoran; Kang, Feiyu; Zhao, Tianshou

    2017-01-25

    The low density associated with low sulfur areal loading in the solid-state sulfur cathode of current Li-S batteries is an issue hindering the development of this type of battery. Polysulfide catholyte as a recyclable liquid fuel was proven to enhance both the energy density and power density of the battery. However, a critical barrier with this lithium (Li)/polysulfide battery is that the shuttle effect, which is the crossover of polysulfides and side deposition on the Li anode, becomes much more severe than that in conventional Li-S batteries with a solid-state sulfur cathode. In this work, we successfully applied an acrylate-based gel polymer electrolyte (GPE) to the Li/polysulfide system. The GPE layer can effectively block the detrimental diffusion of polysulfides and protect the Li metal from the side passivation reaction. Cathode-static batteries utilizing 2 M catholyte (areal sulfur loading of 6.4 mg cm -2 ) present superior cycling stability (727.4 mAh g -1 after 500 cycles at 0.2 C) and high rate capability (814 mAh g -1 at 2 C) and power density (∼10 mW cm -2 ), which also possess replaceable and encapsulated merits for mobile devices. In the cathode-flow mode, the Li/polysulfide system with catholyte supplied from an external tank demonstrates further improved power density (∼69 mW cm -2 ) and stable cycling performance. This novel and simple Li/polysulfide system represents a significant advancement of high energy density sulfur-based batteries for future power sources.

  13. 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.

  14. Fabrication of Cost-Effective Dye-Sensitized Solar Cells Using Sheet-Like CoS2 Films and Phthaloylchitosan-Based Gel-Polymer Electrolyte

    Directory of Open Access Journals (Sweden)

    Saradh Prasad

    2018-01-01

    Full Text Available Platinum-free counter electrodes (CE were developed for use in efficient and cost-effective energy conversion devices, such as dye-sensitized solar cells (DSSCs. Electrochemical deposition of CoS2 on fluorine-doped tin oxide (FTO formed a hierarchical sheet-like structured CoS2 thin film. This film was engaged as a cost-effective platinum-free and high-efficiency CE for DSSCs. High stability was achieved using a phthaloychitosan-based gel-polymer electrolyte as the redox electrolyte. The electrocatalytic performance of the sheet-like CoS2 film was analyzed by electrochemical impedance spectroscopy and cyclic voltammetry. The film displayed improved electrocatalytic behavior that can be credited to a low charge-transfer resistance at the CE/electrolyte boundary and improved exchange between triiodide and iodide ions. The fabricated DSSCs with a phthaloychitosan-based gel-polymer electrolyte and sheet-like CoS2 CE had a power conversion efficiency (PCE, η of 7.29% with a fill factor (FF of 0.64, Jsc of 17.51 mA/cm2, and a Voc of 0.65 V, which was analogous to that of Pt CE (η = 7.82%. The high PCE of the sheet-like CoS2 CE arises from the enhanced FF and Jsc, which can be attributed to the abundant active electrocatalytic sites and enhanced interfacial charge-transfer by the well-organized surface structure.

  15. Cationic Polymers Developed for Alkaline Fuel Cell Applications

    Science.gov (United States)

    2015-01-20

    into five categories: proton exchange membrane fuel cell ( PEMFC ), alkaline fuel cell (AFC), molten carbonate fuel cell (MCFC), solid oxide fuel...SOFC and PAFC belong to high temperature fuel cell, which can be applied in stationary power generation. PEMFC and AFC belong to low temperature fuel...function of the polymer electrolyte is to serve as electrolyte to transport ions between electrodes. PEMFC uses a polymer as electrolyte and works

  16. Fiscal 1996 result reports of the researches under consignment from NEDO. Developments of fuel cell technology, polymer electrolyte fuel cell, fuel cell power generation system technology, and high-voltage type several tens kW class distributed power source system; Shin energy sangyo gijutsu sogo kaihatsu kiko itaku gyomu 1996 nendo seika hokokusho. Nenryo denchi gijutsu kaihatsu, kotai kobunshigata nenryo denchi no kenkyu kaihatsu, hatsuden system gijutsu kaihatsu, koden`atsugata suju kW kyu bunsan dengen system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This paper precisely reports the research result on development of fuel cell technology in fiscal 1996. On verification of cell durability, the cell test result in hydrogen including CO of 100ppm using Pt-Ru catalyst as CO resistant catalyst showed that the loss percent of cell voltage decreases with an increase in Ru content. On development of stack technology, the carbon humidification plate superior in chemical stability was developed as one of the parts for layered stacks. The separator with a water- permeable carbon plate and serpentine flow fields was fabricated for highly layered stacks, and achieved the target performance in single cell power generation test. On establishment of design basis for compact fuel processor, the bench-scale test was conducted of Ru/{gamma}-Al2O3 and Pt-Ru/{gamma}-Al2O3 catalysts as advanced CO selective oxidation catalyst for CO reducers. On demonstration test for the several tens kW class stationary power plant, the system configuration of power generation plants using natural gas as fuel was studied. 106 figs., 38 tabs.

  17. Low-temperature fuel cells operating with contaminated feedstock

    NARCIS (Netherlands)

    Wingelaar, P.J.H.

    2007-01-01

    This work concerns the analysis and modeling of the dynamic and static behavior of Polymer Electrolyte Membrane Fuel Cells (PEMFC). Three fundamentally different measurement methods are used to determine the static, the large-signal, and the small-signal dynamic behavior of a fuel cell system. By

  18. Dynamic characteristics of an automotive fuel cell system for transitory load changes

    DEFF Research Database (Denmark)

    Rabbani, Raja Abid; Rokni, Masoud

    2013-01-01

    A dynamic model of Polymer Electrolyte Membrane Fuel Cell (PEMFC) system is developed to investigate the behavior and transient response of a fuel cell system for automotive applications. Fuel cell dynamics are subjected to reactant flows, heat management and water transportation inside the fuel...

  19. Electrocatalytic oxidation of methane: investigations of new catalysts to be used in a solid polymer electrolyte methane fuel-cell; Oxydation electrocatalytique du methane: recherche de catalyseurs en vue d'une application a une pile au methane a electrolyte polymere solide

    Energy Technology Data Exchange (ETDEWEB)

    Berthelot, S

    1998-07-01

    This thesis evaluated the performances of many catalysts facing the methane oxidation which is a critical step in methane fuel cells development. In a first part the study of the methane electro-oxidation has been realized by classical electrochemical technics on many electrodes to determine the most active ones. In a second part the in situ reflection infra-red spectroscopy allowed to identify, during the methane oxidation, the adsorbed species on the electrode and the reaction products. These results also help the understanding of the part of the concerned materials mechanisms in the methane oxidation and then to optimize them for a whole oxidation of the methane in carbon dioxide. The final objective is the use of the methane in a PEMFC fuel cell type. A comparison with the methanol and C2 hydrocarbons behaviour, such as the ethane the ethylene and the acetylene, has been done to evaluate the performances. (A.L.B.)

  20. Determination of As in tobacco by using electrochemical hydride generation at a Nafion® solid polymer electrolyte cell hyphenated with atomic fluorescence spectrometry

    Science.gov (United States)

    Yang, Qinghua; Gan, Wuer; Deng, Yun; Sun, Huihui

    2011-11-01

    In the present work, a novel solid polymer electrolyte hydride generation (SPE-HG) cell was developed. The home-made SPE-HG cell, mainly composed of three components (Nafion®117 membrane for separating and H + exchanging, a soft graphite felt cathode and a Ti mesh modified by Ir anode), was employed for detecting As by coupling to atomic fluorescence spectrometry (AFS). The H + generated by electrolysis of pure water in anode chamber transferred to cathode chamber through SPE, and immediately reacted with As 3 + to generate AsH 3. The relative mechanisms and operation conditions for hydride generation of As were investigated in detail. The developed cell employed water as an alternative of acid anolyte, with virtues of low-cost, more than 6 months lifetime and environment friendly compared with the conventional cell. Under the optimized conditions, the limit of determination of As 3 + for sample blank solution was 0.12 μg L - 1 , the RSD was 2.9% for 10 consecutive measurements of 5 μg L - 1 As 3 + standard solution. The accuracy of the method was verified by the determination of As in the reference Tea (GBW07605) and the developed method was successfully applied to determine trace amounts of As in tobacco samples with recovery from 97% to 103%.

  1. 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

  2. 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

  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. In-situ study of the dendritic growth in lithium/polymer electrolyte-salt/lithium cells; Etude in-situ de la croissance dendritique dans des cellules lithium/POE-sel/lithium

    Energy Technology Data Exchange (ETDEWEB)

    Brissot, C.; Rosso, M.; Chazalviel, J.N. [Ecole Polytechnique, 91 - Palaiseau (France); Baudry, P.; Lascaud, S. [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches

    1996-12-31

    The in-situ observation of dendritic growth in lithium/polymer electrolyte-LiTFSI/lithium battery cells shows that dendrites grow up with about the same rate as anion migration. Memory effects have been evidenced in cycling experiments and limit the dendrites length. An overall movement of the electrolyte due to variations of electrolyte concentration in the vicinity of the electrodes has been observed too. (J.S.) 13 refs.

  5. In-situ study of the dendritic growth in lithium/polymer electrolyte-salt/lithium cells; Etude in-situ de la croissance dendritique dans des cellules lithium/POE-sel/lithium

    Energy Technology Data Exchange (ETDEWEB)

    Brissot, C; Rosso, M; Chazalviel, J N [Ecole Polytechnique, 91 - Palaiseau (France); Baudry, P; Lascaud, S [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches

    1997-12-31

    The in-situ observation of dendritic growth in lithium/polymer electrolyte-LiTFSI/lithium battery cells shows that dendrites grow up with about the same rate as anion migration. Memory effects have been evidenced in cycling experiments and limit the dendrites length. An overall movement of the electrolyte due to variations of electrolyte concentration in the vicinity of the electrodes has been observed too. (J.S.) 13 refs.

  6. Characterization of polymer blends PES/SPSf and PES/SPEEK for direct methanol fuel cells

    NARCIS (Netherlands)

    Manea, G.C.; Mulder, M.H.V.

    2002-01-01

    Existing polymer electrolyte membranes (PEMs) applied for hydrogen fuel cells are frequently not suitable for direct methanol fuel cells due to the high methanol permeability. Therefore, new materials are required and in order to avoid laborious fuel cell experiments with a so-called

  7. Fuel Cells: A Real Option for Unmanned Aerial Vehicles Propulsion

    OpenAIRE

    González_Espasandín, Oscar; Leo Mena, Teresa de Jesus; Navarro Arevalo, Emilio

    2013-01-01

    The possibility of implementing fuel cell technology in Unmanned Aerial Vehicle (UAV) propulsion systems is considered. Potential advantages of the Proton Exchange Membrane or Polymer Electrolyte Membrane (PEMFC) and Direct Methanol Fuel Cells (DMFC), their fuels (hydrogen and methanol), and their storage systems are revised from technical and environmental standpoints. Some operating commercial applications are described. Main constraints for these kinds of fuel cells are analyzed in order t...

  8. A quasi-direct methanol fuel cell system based on blend polymer membrane electrolytes

    DEFF Research Database (Denmark)

    Li, Qingfeng; Hjuler, Hans Aage; Hasiotis, C.

    2002-01-01

    , compared to less than 100 ppm CO for the Nafion-based technology at 80degrees C. The high CO tolerance makes it possible to use the reformed hydrogen directly from a simple methanol reformer without further CO removal. That both the fuel cell and the methanol reformer operate at temperatures around 200......On the basis of blend polymer electrolytes of polybenzimidazole and sulfonated polysulfone, a polymer electrolyte membrane fuel cell was developed with an operational temperature up to 200degrees C. Due to the high operational temperature, the fuel cell can tolerate 1.0-3.0 vol % CO in the fuel...

  9. 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.

  10. 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.

  11. Fuel cell membrane humidification

    Science.gov (United States)

    Wilson, Mahlon S.

    1999-01-01

    A polymer electrolyte membrane fuel cell assembly has an anode side and a cathode side separated by the membrane and generating electrical current by electrochemical reactions between a fuel gas and an oxidant. The anode side comprises a hydrophobic gas diffusion backing contacting one side of the membrane and having hydrophilic areas therein for providing liquid water directly to the one side of the membrane through the hydrophilic areas of the gas diffusion backing. In a preferred embodiment, the hydrophilic areas of the gas diffusion backing are formed by sewing a hydrophilic thread through the backing. Liquid water is distributed over the gas diffusion backing in distribution channels that are separate from the fuel distribution channels.

  12. Low-cost non-fluorinated membranes for fuel cells

    CSIR Research Space (South Africa)

    Luo, H

    2010-08-31

    Full Text Available the driver of the next growth wave of the world’s economy. A proton conductive membrane is the core of the polymer electrolyte membrane fuel cell (PEMFC). Presently, Nafion® membranes are widely used in PEMFC. However, the high cost, low operation temperature...

  13. Air-cooled, hydrogen-air fuel cell

    Science.gov (United States)

    Shelekhin, Alexander B. (Inventor); Bushnell, Calvin L. (Inventor); Pien, Michael S. (Inventor)

    1999-01-01

    An air-cooled, hydrogen-air solid polymer electrolyte (SPE) fuel cell with a membrane electrode assembly operatively associated with a fluid flow plate having at least one plate cooling channel extending through the plate and at least one air distribution hole extending from a surface of the cathode flow field into the plate cooling channel.

  14. A Novel Polymer Electrolyte Using In-situ Quanternization for All Solid-state Dye-sensitized Solar Cell

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Introduction Dye-sensitized solar cells (DSSCs) with a mesoporous network of interconnected TiO2 nanocrystals have attracted wide-spread scientific and technological interest over the past decades due to its low cost and high energy conversion efficiency. Meantime, it also has been considered as potential alternative to conventional photovoltaic devices. In 2001, Gratzel group constructed such kind of DSSC with the conversion efficiency of more than 11%[1]. But this system uses liquid electrolyte with...

  15. End plate for e.g. solid oxide fuel cell stack, sets thermal expansion coefficient of material to predetermined value

    DEFF Research Database (Denmark)

    2011-01-01

    .05-0.3 mm. USE - End plate for solid oxide fuel cell stack (claimed). Can also be used in polymer electrolyte fuel cell stack and direct methanol fuel cell stack. ADVANTAGE - The robustness of the end plate is improved. The structure of the end plate is simplified. The risk of delamination of the stack...

  16. Enhanced performance of a quasi-solid-state dye-sensitized solar cell with aluminum nitride in its gel polymer electrolyte

    KAUST Repository

    Huang, Kuan-Chieh

    2011-08-01

    The effects of incorporation of aluminum nitride (AlN) in the gel polymer electrolyte (GPE) of a quasi-solid-state dye-sensitized solar cell (DSSC) were studied in terms of performance of the cell. The electrolyte, consisting of lithium iodide (LiI), iodine (I2), and 4-tert-butylpyridine (TBP) in 3-methoxypropionitrile (MPN), was solidified with poly(vinyidene fluoride-co-hexafluoro propylene) (PVDF-HFP). The 0.05, 0.1, 0.3, and 0.5 wt% of AlN were added to the electrolyte for this study. XRD analysis showed a reduction of crystallinity in the polymer PVDF-HFP for all the additions of AlN. The DSSC fabricated with a GPE containing 0.1 wt% AlN showed a short-circuit current density (JSC) and power-conversion efficiency (η) of 12.92±0.54 mA/cm2 and 5.27±0.23%, respectively, at 100 mW/cm2 illumination, in contrast to the corresponding values of 11.52±0.21 mA/cm2 and 4.75±0.08% for a cell without AlN. The increases both in JSC and in η of the promoted DSSC are attributed to the higher apparent diffusion coefficient of I- in its electrolyte (3.52×10-6 cm2/s), compared to that in the electrolyte without AlN of a DSSC (2.97×10-6 cm 2/s). At-rest stability of the quasi-solid-state DSSC with 0.1 wt% of AlN was found to decrease hardly by 5% and 7% at room temperature and at 40 °C, respectively, after 1000 h duration. The DSSC with a liquid electrolyte showed a decrease of about 40% at room temperature, while it virtually lost its performance in about 150 h at 40 °C. Explanations are further substantiated by means of electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and by porosity measurements. © 2010 Elsevier B.V.

  17. Nanostructured TiO2 microspheres for dye-sensitized solar cells employing a solid state polymer electrolyte

    International Nuclear Information System (INIS)

    Jung, Hun-Gi; Nagarajan, Srinivasan; Kang, Yong Soo; Sun, Yang-Kook

    2013-01-01

    Bimodal mesoporous, anatase TiO 2 microspheres with particle sizes ranging from 0.3 to 2 μm were synthesized using a facile solvothermal method. The photovoltaic performance of TiO 2 microspheres in dye-sensitized solar cells (DSSCs) using a solid state electrolyte was investigated. The solid state electrolyte DSSC device based on the TiO 2 microspheres exhibits an energy conversion efficiency of 4.2%, which is greater than that of commercial P25 TiO 2 (3.6%). The higher photocurrent density was primarily achieved as a result of the greater specific surface area and pore size, which resulted in an increase in the dye uptake of the TiO 2 microspheres and easy transport of solid electrolyte through mesopores. In addition, the greater electron lifetime and superior light scattering ability also enhanced the photovoltaic performance of the TiO 2 microsphere-based, solid state DSSCs

  18. FY 1999 Results of research and development project for polymer electrolyte fuel cells (PEFCs). Development of high current density type 10kW class portable power source systems; 1999 nendo kotai kobunshigata nenryo denchi no kenkyu kaihatsu seika hokokusho. Kodenryu mitsudogata 10kW kyu kahangata dengen system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Described herein are the FY 1999 results of the research and development project aimed at development of multi-stacked PEFC modules and plate-stack type methanol reformers, and researches on portable power source systems, for development of methanol-air 10kW class (over 0.3W/cm{sup 2}) PEFC systems for portable use by the end of the FY 2000. The programs for the multi-stacked PEFC modules include improvement of tolerance against CO by improvement of catalyst bed and gas passage structures; development of a multi-stacked 5kW class stack structured to prevent fuel starvation; endurance tests conducted at a constant load using a simulated methanol reformate gas; and development, on a trial basis, of the stack using a formed separator. The programs for the plate-stack type methanol reformers include development, on a trial basis, of reforming catalysts integrated with flow passages, combustion catalysts and CO oxidation catalysts, and endurance evaluation tests for the reformer elements. The researches on portable power source systems include studies on, e.g., system control/behavior and efficiency, and basic system designs. The performance and environment endurance tests are also conducted for auxiliary equipment, e.g., blowers. (NEDO)

  19. NASA Glenn Research Center Electrochemistry Branch Battery and Fuel Cell Development Overview

    Science.gov (United States)

    Manzo, Michelle A.

    2011-01-01

    This presentation covers an overview of NASA Glenn s history and heritage in the development of electrochemical systems for aerospace applications. Current developments related to batteries and fuel cells are addressed. Specific areas of focus are Li-ion batteries and Polymer Electrolyte Membrane Fuel cells systems and their development for future Exploration missions.

  20. The start-up analysis of a PEM fuel cell system in vehicles

    DEFF Research Database (Denmark)

    Rabbani, Raja Abid; Rokni, Masoud; Hosseinzadeh, Elham

    2014-01-01

    Addressing large load fluctuation in automotive applications, dynamic analysis of a polymer electrolyte membrane fuel cell system is conducted here. Operations of a comprehensive system-level control-oriented fuel cell model with all necessary auxiliary components are demonstrated and simulation ...

  1. Study on performance simulation of polymer electrolyte fuel cell for preventing degradation

    International Nuclear Information System (INIS)

    Kobayashi, T; Doi, M; Fukuda, T; Hashimoto, R; Kanematsu, H; Utsumi, Y

    2013-01-01

    In the present study, the distribution of water content in the membrane of PEFC was analyzed by using a numerical simulation as well as understanding the behavior of internal moisture of PEFC. Eight parameters were selected for the simulation then 18 combinations of the parameters were allocated by design of experiments, thus the data obtained were analyzed by multiple regression analysis to understand the influence factor of operating conditions quantitatively. As a result, the influence of the operating parameters on the dryness of the membrane for the anode side and the cathode side of PEFC was quantitatively shown by using the method of the multiple regression analysis. Further it was found that the area where cerium carbonate ought to be coated for preventing the degradation without decreasing performance.

  2. Observation of ionomer in catalyst ink of polymer electrolyte fuel cell using cryogenic transmission electron microscopy

    International Nuclear Information System (INIS)

    Takahashi, Shinichi; Shimanuki, Junichi; Mashio, Tetsuya; Ohma, Atsushi; Tohma, Hajime; Ishihara, Ayumi; Ito, Yoshiko; Nishino, Yuri; Miyazawa, Atsuo

    2017-01-01

    Optimizing the catalyst layer structure is one of the key issues for improving performance despite lower platinum loading. The catalyst ink, consisting of platinum-loaded carbon particles and ionomer dispersed in an aqueous solvent, is a key factor for controlling the structure of the catalyst layer because the catalyst layer is prepared in a wet coating process. For that purpose, we visualized the nanostructure of the ionomer in the catalyst ink by cryogenic electron microscopy, especially cryogenic transmission electron microscopy (cryo-TEM). By cryo-TEM, it was revealed that ionomer molecules formed rod-like aggregates macro-homogeneously in the solvent, and a similar morphology was observed in a carbon-particle-containing solvent. In contrast, ionomer aggregates in the catalyst ink containing platinum nanoparticles loaded on carbon particles were denser in the vicinity of the platinum-loaded carbon particles. That can be attributed to strong interaction between platinum nanoparticles and sulfonic acid groups in the ionomer. It also implies that a good understanding of ionomer morphology in the catalyst ink can play an important role in controlling the catalyst layer microstructure for reducing platinum loading.

  3. Titanium-Niobium Oxides as Non-Noble Metal Cathodes for Polymer Electrolyte Fuel Cells

    Directory of Open Access Journals (Sweden)

    Akimitsu Ishihara

    2015-07-01

    Full Text Available In order to develop noble-metal- and carbon-free cathodes, titanium-niobium oxides were prepared as active materials for oxide-based cathodes and the factors affecting the oxygen reduction reaction (ORR activity were evaluated. The high concentration sol-gel method was employed to prepare the precursor. Heat treatment in Ar containing 4% H2 at 700–900 °C was effective for conferring ORR activity to the oxide. Notably, the onset potential for the ORR of the catalyst prepared at 700 °C was approximately 1.0 V vs. RHE, resulting in high quality active sites for the ORR. X-ray (diffraction and photoelectron spectroscopic analyses and ionization potential measurements suggested that localized electronic energy levels were produced via heat treatment under reductive atmosphere. Adsorption of oxygen molecules on the oxide may be governed by the localized electronic energy levels produced by the valence changes induced by substitutional metal ions and/or oxygen vacancies.

  4. 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

  5. Synthesis, ionic conductivity, and thermal properties of proton conducting polymer electrolyte for high temperature fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Takahito; Hamaguchi, Yohei; Uno, Takahiro; Kubo, Masataka [Department of Chemistry for Materials, Faculty of Engineering, Mie University, 1577 Kurima Machiya-cho, Tsu, Mie 514-8507 (Japan); Aihara, Yuichi; Sonai, Atsuo [Samsung Yokohama Research Institute, 2-7 Sugasawa-cho, Tsurumi-ku, Yokohama 230-0027 (Japan)

    2006-01-16

    Hyperbranched polymer (poly-1a) with sulfonic acid groups at the end of chains was successfully synthesized. Interpenetration reaction of poly-1a with a hyperbranched polymer with acryloyl groups at the end of chains (poly-1b) as a cross-linker afforded a tough electrolyte membrane. The poly-1a and the resulting electrolyte membrane showed the ionic conductivities of 7x10{sup -4} and 8x10{sup -5} S/cm, respectively, at 150C under dry condition. The ionic conductivities of the poly-1a and the electrolyte membrane exhibited the VTF type temperature dependence. And also, both poly-1a and the resulting electrolyte membrane were thermally stable up to 200C. (author)

  6. 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...

  7. Challenge of non-precious metal oxide-based cathode for polymer electrolyte fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Ishihara, Akimitsu; Matsuzawa, Koichi; Mitsushima, Shigenori; Ota, Ken-ichiro [Yokohama National Univ. (Japan)

    2010-07-01

    The partially oxidized TaC{sub 0.58}N{sub 0.42} was investigated as non-platinum cathode for PEFC. In order to quantify the degree of oxidation, the degree of oxidation (DOO) was defined using the XRD peaks of Ta-CN and Ta{sub 2}O{sub 5}. The onset potential for the oxidation reduction reaction (ORR) had high value, that is, 0.9 V vs. RHE (reversible hydrogen electrode), at higher oxidation state of the TaC{sub 0.58}N{sub 0.42}. We found that the partial oxidation of TaC{sub 0.58}N{sub 0.42} was greatly useful to enhance the catalytic activity for the ORR. The volcano plot of the ionization potential vs. the E{sub ORR} suggested that there was a suitable interaction between the surface of the partially oxidized TaC{sub 0.58}N{sub 0.42} and oxygen. (orig.)

  8. Third International Fuel Cell Conference. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-30

    The Third International Fuel Cell Conference was held on November 30 to December 3, 1999 in City of Nagoya. A total of 139 papers, including those for plenary, sectional and poster cessions, were presented. In the plenary session, US's DOE presented fuel cell power plant development in the United States, EC fuel cells in perspective and fifth European framework programme, and Japan overview of the New Sunshine Program. In the polymer electrolyte fuel cells sessions, 23 papers were presented, including current status of commercialization and PEMFC systems developed by Toshiba. In the phosphoric acid fuel cells session, 6 papers were presented, including field test results and market developments. In the molten carbonate fuel cells session, 24 papers were presented, including development of 1,000kW MCFC power plant. In the solid oxide fuel cells session, 20 papers were presented, including 100kW SOFC field test results. The other topics include market analysis and fuel processes. (NEDO)

  9. Carbon Nanotubes and Other Nanostructures as Support Material for Nanoparticulate Noble-Metal Catalysts in Fuel Cells

    DEFF Research Database (Denmark)

    Larsen, Mikkel Juul; Veltzé, Sune; Skou, Eivind Morten

    In polymer electrolyte membrane fuel cells (PEMFC) a fuel - usually hydrogen - and oxygen are combined to produce electricity and water in an electrochemical process, which is commonly carried out at 60-80 °C. For oxygen reduction and fuel oxidation to occur at such low temperatures platinum or p...

  10. 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.

  11. Fuel cells: a real option for Unmanned Aerial Vehicles propulsion.

    Science.gov (United States)

    González-Espasandín, Óscar; Leo, Teresa J; Navarro-Arévalo, Emilio

    2014-01-01

    The possibility of implementing fuel cell technology in Unmanned Aerial Vehicle (UAV) propulsion systems is considered. Potential advantages of the Proton Exchange Membrane or Polymer Electrolyte Membrane (PEMFC) and Direct Methanol Fuel Cells (DMFC), their fuels (hydrogen and methanol), and their storage systems are revised from technical and environmental standpoints. Some operating commercial applications are described. Main constraints for these kinds of fuel cells are analyzed in order to elucidate the viability of future developments. Since the low power density is the main problem of fuel cells, hybridization with electric batteries, necessary in most cases, is also explored.

  12. Fuel Cells: A Real Option for Unmanned Aerial Vehicles Propulsion

    Science.gov (United States)

    2014-01-01

    The possibility of implementing fuel cell technology in Unmanned Aerial Vehicle (UAV) propulsion systems is considered. Potential advantages of the Proton Exchange Membrane or Polymer Electrolyte Membrane (PEMFC) and Direct Methanol Fuel Cells (DMFC), their fuels (hydrogen and methanol), and their storage systems are revised from technical and environmental standpoints. Some operating commercial applications are described. Main constraints for these kinds of fuel cells are analyzed in order to elucidate the viability of future developments. Since the low power density is the main problem of fuel cells, hybridization with electric batteries, necessary in most cases, is also explored. PMID:24600326

  13. Fuel Cells: A Real Option for Unmanned Aerial Vehicles Propulsion

    Directory of Open Access Journals (Sweden)

    Óscar González-Espasandín

    2014-01-01

    Full Text Available The possibility of implementing fuel cell technology in Unmanned Aerial Vehicle (UAV propulsion systems is considered. Potential advantages of the Proton Exchange Membrane or Polymer Electrolyte Membrane (PEMFC and Direct Methanol Fuel Cells (DMFC, their fuels (hydrogen and methanol, and their storage systems are revised from technical and environmental standpoints. Some operating commercial applications are described. Main constraints for these kinds of fuel cells are analyzed in order to elucidate the viability of future developments. Since the low power density is the main problem of fuel cells, hybridization with electric batteries, necessary in most cases, is also explored.

  14. 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}.

  15. Fuel cell power plants for automotive applications

    Science.gov (United States)

    McElroy, J. F.

    1983-02-01

    While the Solid Polymer Electrolyte (SPE) fuel cell has until recently not been considered competitive with such commercial and industrial energy systems as gas turbine generators and internal combustion engines, electrical current density improvements have markedly improved the capital cost/kW output rating performance of SPE systems. Recent studies of SPE fuel cell applicability to vehicular propulsion have indicated that with adequate development, a powerplant may be produced which will satisfy the performance, size and weight objectives required for viable electric vehicles, and that the cost for such a system would be competitive with alternative advanced power systems.

  16. Electrolytes for solid oxide fuel cells

    Science.gov (United States)

    Fergus, Jeffrey W.

    The high operating temperature of solid oxide fuel cells (SOFCs), as compared to polymer electrolyte membrane fuel cells (PEMFCs), improves tolerance to impurities in the fuel, but also creates challenges in the development of suitable materials for the various fuel cell components. In response to these challenges, intermediate temperature solid oxide fuel cells (IT-SOFCs) are being developed to reduce high-temperature material requirements, which will extend useful lifetime, improve durability and reduce cost, while maintaining good fuel flexibility. A major challenge in reducing the operating temperature of SOFCs is the development of solid electrolyte materials with sufficient conductivity to maintain acceptably low ohmic losses during operation. In this paper, solid electrolytes being developed for solid oxide fuel cells, including zirconia-, ceria- and lanthanum gallate-based materials, are reviewed and compared. The focus is on the conductivity, but other issues, such as compatibility with electrode materials, are also discussed.

  17. Electrolytes for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-11-08

    The high operating temperature of solid oxide fuel cells (SOFCs), as compared to polymer electrolyte membrane fuel cells (PEMFCs), improves tolerance to impurities in the fuel, but also creates challenges in the development of suitable materials for the various fuel cell components. In response to these challenges, intermediate temperature solid oxide fuel cells (IT-SOFCs) are being developed to reduce high-temperature material requirements, which will extend useful lifetime, improve durability and reduce cost, while maintaining good fuel flexibility. A major challenge in reducing the operating temperature of SOFCs is the development of solid electrolyte materials with sufficient conductivity to maintain acceptably low ohmic losses during operation. In this paper, solid electrolytes being developed for solid oxide fuel cells, including zirconia-, ceria- and lanthanum gallate-based materials, are reviewed and compared. The focus is on the conductivity, but other issues, such as compatibility with electrode materials, are also discussed. (author)

  18. Hydrogen storage and fuel cells

    Science.gov (United States)

    Liu, Di-Jia

    2018-01-01

    Global warming and future energy supply are two major challenges facing American public today. To overcome such challenges, it is imperative to maximize the existing fuel utilization with new conversion technologies while exploring alternative energy sources with minimal environmental impact. Hydrogen fuel cell represents a next-generation energy-efficient technology in transportation and stationary power productions. In this presentation, a brief overview of the current technology status of on-board hydrogen storage and polymer electrolyte membrane fuel cell in transportation will be provided. The directions of the future researches in these technological fields, including a recent "big idea" of "H2@Scale" currently developed at the U. S. Department of Energy, will also be discussed.

  19. 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.

  20. 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)

  1. FY 1999 Report on results of development of high-efficiency energy system technologies for transportation and domestic use. R and D of polymer electrolyte fuel cells, power system technologies, and several kW class domestic power systems operating at normal pressure; 1999 nendo un'yu minseiyo kokoritsu energy system gijutsu kaihatsu, kotai kobunshigata nenryo denchi no kenkyu kaihatsu, hatsuden system gijutsu kaihatsu, joatsu sadogata su kW kyu kateiyo dengen system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Described herein are the FY 1999 results of the research and development project aimed at development of fuel cell systems for power source systems suitable for domestic use. The programs for development of fuel cell body include improvement of the anode forming method for increasing its CO tolerance, enhancing cell performance at 0.5mg-metal/cm{sup 2} as the catalyst quantity to a level almost comparable to that obtainable at 0.9mg-metal/cm{sup 2}. The programs for development of the fuel supply system include studies on endurance of the elements, e.g., starting-up/shutting-down of the Ru/Al{sub 2}O{sub 3} catalyst, using a microreactor, confirming that it is serviceable for at least 1,000 hours. The natural gas reformer is developed and operated, on a trial basis, achieving stable supply of steam and fuel, and thermal efficiency of 82.7%. The operation researches include development and operation of a 1kW class module, achieving the performance surpassing the FY 1999 targets (average cell voltage: 0.70V, output: 1.27kW) with a simulated reformate gas at an air utilization rate of 20% and current density of 0.3A/cm{sup 2}. (NEDO)

  2. Effect of nitrogen crossover on purging strategy in PEM fuel cell systems

    DEFF Research Database (Denmark)

    Rabbani, Raja Abid; Rokni, Masoud

    2013-01-01

    A comprehensive study on nitrogen crossover in polymer electrolyte membrane fuel cell (PEMFC) system with anode recirculation is conducted and associated purging strategies are discussed. Such systems when employed in automobiles are subjected to continuous changes in load and external operating...

  3. Modelling membrane hydration and water balance of a pem fuel cell

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Nielsen, Mads Pagh

    2015-01-01

    Polymer electrolyte membrane (PEM) fuel cells requires an appropriate hydration in order to ensure high efficiency and long durability. As water is essential for promoting proton conductivity in the membrane, it is important to control membrane water hydration to avoid flooding. In this study we...

  4. A comprehensive, consistent and systematic mathematical model of PEM fuel cells

    International Nuclear Information System (INIS)

    Baschuk, J.J.; Li Xianguo

    2009-01-01

    This paper presents a comprehensive, consistent and systematic mathematical model for PEM fuel cells that can be used as the general formulation for the simulation and analysis of PEM fuel cells. As an illustration, the model is applied to an isothermal, steady state, two-dimensional PEM fuel cell. Water is assumed to be in either the gas phase or as a liquid phase in the pores of the polymer electrolyte. The model includes the transport of gas in the gas flow channels, electrode backing and catalyst layers; the transport of water and hydronium in the polymer electrolyte of the catalyst and polymer electrolyte layers; and the transport of electrical current in the solid phase. Water and ion transport in the polymer electrolyte was modeled using the generalized Stefan-Maxwell equations, based on non-equilibrium thermodynamics. Model simulations show that the bulk, convective gas velocity facilitates hydrogen transport from the gas flow channels to the anode catalyst layers, but inhibits oxygen transport. While some of the water required by the anode is supplied by the water produced in the cathode, the majority of water must be supplied by the anode gas phase, making operation with fully humidified reactants necessary. The length of the gas flow channel has a significant effect on the current production of the PEM fuel cell, with a longer channel length having a lower performance relative to a shorter channel length. This lower performance is caused by a greater variation in water content within the longer channel length

  5. Status and promise of fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Williams, M.C. [National Energy Technology Lab., Pittsburgh, PA (United States). Dept. of Energy

    2001-09-01

    The niche or early entry market penetration by ONSI and its phosphoric acid fuel cell technology has proven that fuel cells are reliable and suitable for premium power and other opportunity fuel niche market applications. Now, new fuel cell technologies - solid oxide fuel cells, molten carbonate fuel cells, and polymer electrolyte fuel cells - are being developed for near-term distributed generation shortly after 2003. Some of the evolving fuel cell systems are incorporating gas turbines in hybrid configurations. The combination of the gas turbine with the fuel cell promises to lower system costs and increase efficiency to enhance market penetration. Market estimates indicate that significant early entry markets exist to sustain the initially high cost of some distributed generation technologies. However, distributed generation technologies must have low introductory first cost, low installation cost, and high system reliability to be viable options in competitive commercial and industrial markets. In the long-term, solid state fuel cell technology with stack costs under $100/kilowatt (kW) promises deeper and wider market penetration in a range of applications including a residential, auxillary power, and the mature distributed generation markets. The solid state energy conversion alliance (SECA) with its vision for fuel cells in 2010 was recently formed to commercialize solid state fuel cells and realize the full potential of the fuel cell technology. Ultimately, the SECA concept could lead to megawatt-size fuel-cell systems for commercial and industrial applications and Vision 21 fuel cell turbine hybrid energy plants in 2015. (orig.)

  6. High Temperature PEM Fuel Cell Stacks with Advent TPS Meas

    Directory of Open Access Journals (Sweden)

    Neophytides Stylianos

    2017-01-01

    Full Text Available High power/high energy applications are expected to greatly benefit from high temperature Polymer Electrolyte Membrane Fuel Cells (PEMFCs. In this work, a combinatorial approach is presented, in which separately developed and evaluated MEAs, design and engineering are employed to result in reliable and effective stacks operating above 180°C and having the characteristics well matched to applications including auxiliary power, micro combined heat and power, and telecommunication satellites.

  7. Hydrogen-Oxygen PEM Regenerative Fuel Cell Energy Storage System

    Science.gov (United States)

    Bents, David J.; Scullin, Vincent J.; Chang, Bei-Jiann; Johnson, Donald W.; Garcia, Christopher P.

    2005-01-01

    An introduction to the closed cycle hydrogen-oxygen polymer electrolyte membrane (PEM) regenerative fuel cell (RFC), recently constructed at NASA Glenn Research Center, is presented. Illustrated with explanatory graphics and figures, this report outlines the engineering motivations for the RFC as a solar energy storage device, the system requirements, layout and hardware detail of the RFC unit at NASA Glenn, the construction history, and test experience accumulated to date with this unit.

  8. 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.

  9. INVESTIGATION OF PEM FUEL CELL FOR AUTOMOTIVE USE

    Directory of Open Access Journals (Sweden)

    A. K. M. Mohiuddin

    2015-11-01

    Full Text Available This paper provides a brief investigation on suitability of Proton-exchange  membrane fuel cells (PEMFCs as the source of power for transportation purposes. Hydrogen is an attractive alternative transportation fuel. It is the least polluting fuel that can be used in an internal combustion engine (ICE and it is widely available. If hydrogen is used in a fuel cell which converts the chemical energy of hydrogen into electricity, (NOx emissions are eliminated. The investigation was carried out on a  fuel cell car model by implementing polymer electrolyte membrane (PEM types of fuel cell as the source of power to propel the prototype car. This PEMFC has capability to propel the electric motor by converting chemical energy stored in hydrogen gas into useful electrical energy. PEM fuel cell alone is used as the power source for the electric motor without the aid of any other power source such as battery associated with it. Experimental investigations were carried out to investigate the characteristics of fuel cell used and the performance of the fuel cell car. Investigated papameters are the power it develops, voltage, current and speed it produces under different load conditions. KEYWORDS: fuel cell; automotive; proton exchange membrane; polymer electrolyte membrane; internal combustion engine

  10. 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.

  11. 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)

  12. 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)

  13. Methods of conditioning direct methanol fuel cells

    Science.gov (United States)

    Rice, Cynthia; Ren, Xiaoming; Gottesfeld, Shimshon

    2005-11-08

    Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell ("DMFC") are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer electrolyte membrane of the membrane electrode assembly to a cathode surface of the membrane electrode assembly, and an electrical current of polarity opposite to that in a functioning direct methanol fuel cell is drawn through the membrane electrode assembly, wherein methanol is oxidized at the cathode surface of the membrane electrode assembly while the catalyst on the anode surface is reduced. Surface oxides on the direct methanol fuel cell anode catalyst of the membrane electrode assembly are thereby reduced.

  14. 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.

  15. Modeling and experimental validation of water mass balance in a PEM fuel cell stack

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Araya, Samuel Simon; Olesen, Anders Christian

    2016-01-01

    Polymer electrolyte membrane (PEM) fuel cells require good hydration in order to deliver high performance and ensure long life operation. Water is essential for proton conductivity in the membrane which increases by nearly six orders of magnitude from dry to fully hydrated. Adequate water...... management in PEM fuel cell is crucial in order to avoid an imbalance between water production and water removal from the fuel cell. In the present study, a novel mathematical zero-dimensional model has been formulated for the water mass balance and hydration of a polymer electrolyte membrane. This model...... is validated against experimental data. In the results it is shown that the fuel cell water balance calculated by this model shows better fit with experimental data-points compared with model where only steady state operation were considered. We conclude that this discrepancy is due a different rate of water...

  16. Fuel Cell Handbook, Fifth Edition

    Energy Technology Data Exchange (ETDEWEB)

    Energy and Environmental Solutions

    2000-10-31

    Progress continues in fuel cell technology since the previous edition of the Fuel Cell Handbook was published in November 1998. Uppermost, polymer electrolyte fuel cells, molten carbonate fuel cells, and solid oxide fuel cells have been demonstrated at commercial size in power plants. The previously demonstrated phosphoric acid fuel cells have entered the marketplace with more than 220 power plants delivered. Highlighting this commercial entry, the phosphoric acid power plant fleet has demonstrated 95+% availability and several units have passed 40,000 hours of operation. One unit has operated over 49,000 hours. Early expectations of very low emissions and relatively high efficiencies have been met in power plants with each type of fuel cell. Fuel flexibility has been demonstrated using natural gas, propane, landfill gas, anaerobic digester gas, military logistic fuels, and coal gas, greatly expanding market opportunities. Transportation markets worldwide have shown remarkable interest in fuel cells; nearly every major vehicle manufacturer in the U.S., Europe, and the Far East is supporting development. This Handbook provides a foundation in fuel cells for persons wanting a better understanding of the technology, its benefits, and the systems issues that influence its application. Trends in technology are discussed, including next-generation concepts that promise ultrahigh efficiency and low cost, while providing exceptionally clean power plant systems. Section 1 summarizes fuel cell progress since the last edition and includes existing power plant nameplate data. Section 2 addresses the thermodynamics of fuel cells to provide an understanding of fuel cell operation at two levels (basic and advanced). Sections 3 through 8 describe the six major fuel cell types and their performance based on cell operating conditions. Alkaline and intermediate solid state fuel cells were added to this edition of the Handbook. New information indicates that manufacturers have stayed

  17. Fuel cells for electricity generation from carbonaceous fuels

    Energy Technology Data Exchange (ETDEWEB)

    Ledjeff-Hey, K; Formanski, V; Roes, J [Gerhard-Mercator- Universitaet - Gesamthochschule Duisburg, Fachbereich Maschinenbau/Fachgebiet Energietechnik, Duisburg (Germany); Heinzel, A [Fraunhofer Inst. for Solar Energy Systems (ISE), Freiburg (Germany)

    1998-09-01

    Fuel cells, which are electrochemical systems converting chemical energy directly into electrical energy with water and heat as by-products, are of interest as a means of generating electricity which is environmentally friendly, clean and highly efficient. They are classified according to the electrolyte used. The main types of cell in order of operating temperature are described. These are: alkaline fuel cells, the polymer electrolyte membrane fuel cell (PEMFC); the phosphoric acid fuel cell (PAFC); the molten carbonate fuel cell (MCFC); the solid oxide fuel cell (SOFC). Applications depend on the type of cell and may range from power generation on a large scale to mobile application in cars or portable systems. One of the most promising options is the PEM-fuel cell stack where there has been significant improvement in power density in recent years. The production from carbonaceous fuels and purification of the cell fuel, hydrogen, is considered. Of the purification methods available, hydrogen separation by means of palladium alloy membranes seems particular effective in reducing CO concentrations to the low levels required for PEM cells. (UK)

  18. Hydrogen-bromine fuel cell advance component development

    Science.gov (United States)

    Charleston, Joann; Reed, James

    1988-01-01

    Advanced cell component development is performed by NASA Lewis to achieve improved performance and longer life for the hydrogen-bromine fuel cells system. The state-of-the-art hydrogen-bromine system utilizes the solid polymer electrolyte (SPE) technology, similar to the SPE technology developed for the hydrogen-oxygen fuel cell system. These studies are directed at exploring the potential for this system by assessing and evaluating various types of materials for cell parts and electrode materials for Bromine-hydrogen bromine environment and fabricating experimental membrane/electrode-catalysts by chemical deposition.

  19. 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

  20. Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell

    Science.gov (United States)

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

    1987-01-01

    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.

  1. 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 ...

  2. Arrangement of fuel cell system for TNRF

    International Nuclear Information System (INIS)

    Nojima, Takehiro; Yasuda, Ryo; Iikura, Hiroshi; Sakai, Takuro; Matsubayashi, Masahito; Takenaka, Nobuyuki; Hayashida, Hirotoshi

    2012-02-01

    Polymer electrolyte fuel cells (fuel cells) can be potentially employed as sources of clean energy because they discharge only water as by-products. Fuel cells generate electricity with supply of oxygen and hydrogen gases. However, the water produced by the fuel cells blocks the gas supply, thereby degrading their performances. Therefore, it is important to understand the behavior of the water produced by the fuel cells in order to facilitate their development. Neutron radiography is a useful tool for visualizing the distribution of water in fuel cells. We have designed fuel cell operation system for TNRF (Thermal Neutron Radiography Facility) at JRR-3. The fuel cell operation system consists of various components such as gas flow and humidification systems, hydrogen-diluting system, purge system, and safety system for hydrogen gas. We tested this system using a Japan Automobile Research Institute (JARI) standard cell. The system performed stably and efficiently. In addition, neutron radiography tests were carried out to visualize the water distribution. The water produced by the fuel cell was observed during the fuel cell operation. (author)

  3. 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.

  4. Fuel cells science and engineering. Materials, processes, systems and technology. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Stolten, Detlef; Emonts, Bernd (eds.) [Forschungszentrum Juelich GmbH (DE). Inst. fuer Energieforschung (IEF), Brennstoffzellen (IEF-3)

    2012-07-01

    The second volume is divided in four parts and 19 chapters. It is structured as follows: PART V: Modeling and Simulation. Chapter 23: Messages from Analytical Modeling of Fuel Cells (Andrei Kulikovsky); 24: Stochastic Modeling of Fuel-Cell Components (Ralf Thiedmann, Gerd Gaiselmann, Werner Lehnert and Volker Schmidt); 25: Computational Fluid Dynamic Simulation Using Supercomputer Calculation Capacity (Ralf Peters and Florian Scharf); 26 Modeling Solid Oxide Fuel Cells from the Macroscale to the Nanoscale (Emily M. Ryan and Mohammad A. Khaleel); 27: Numerical Modeling of the Thermomechanically Induced Stress in Solid Oxide Fuel Cells (Murat Peksen); 28: Modeling of Molten Carbonate Fuel Cells (Peter Heidebrecht, Silvia Piewek and Kai Sundmacher); Chapter 29: High-Temperature Polymer Electrolyte Fuel-Cell Modeling (Uwe Reimer); Chapter 30: Modeling of Polymer Electrolyte Membrane Fuel-Cell Components (Yun Wang and Ken S. Chen); 31: Modeling of Polymer Electrolyte Membrane Fuel Cells and Stacks (Yun Wang and Ken S. Chen). PART VI: Balance of Plant Design and Components. Chapter 32: Principles of Systems Engineering (Ludger Blum, Ralf Peters and Remzi Can Samsun); 33: System Technology for Solid Oxide Fuel Cells (Nguyen Q. Minh); 34: Desulfurization for Fuel-Cell Systems (Joachim Pasel and Ralf Peters); 35: Design Criteria and Components for Fuel Cell Powertrains (Lutz Eckstein and Bruno Gnoerich); 36: Hybridization for Fuel Cells (Joerg Wilhelm). PART VII: Systems Verification and Market Introduction. Chapter 37: Off-Grid Power Supply and Premium Power Generation (Kerry-Ann Adamson); 38: Demonstration Projects and Market Introduction (Kristin Deason). PART VIII: Knowledge Distribution and Public Awareness. Chapter 39: A Sustainable Framework for International Collaboration: the IEA HIA and Its Strategic Plan for 2009-2015 (Mary-Rose de Valladares); 40: Overview of Fuel Cell and Hydrogen Organizations and Initiatives Worldwide (Bernd Emonts) 41: Contributions for

  5. PEM fuel cells thermal and water management fundamentals

    CERN Document Server

    Wang, Yun; Cho, Sung Chan

    2014-01-01

    Polymer Electrolyte Membrane (PEM) fuel cells convert chemical energy in hydrogen into electrical energy with water as the only by-product. Thus, PEM fuel cells hold great promise to reduce both pollutant emissions and dependency on fossil fuels, especially for transportation-passenger cars, utility vehicles, and buses-and small-scale stationary and portable power generators. But one of the greatest challenges to realizing the high efficiency and zero emissions potential of PEM fuel cells technology is heat and water management. This book provides an introduction to the essential concepts for effective thermal and water management in PEM fuel cells and an assessment on the current status of fundamental research in this field. The book offers you: An overview of current energy and environmental challenges and their imperatives for the development of renewable energy resources, including discussion of the role of PEM fuel cells in addressing these issues; Reviews of basic principles pertaining to PEM fuel cel...

  6. 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.

  7. First commercial fuel cells in emergency power supplies; Erste kommerzielle Brennstoffzellen im Notstrombereich. Praxistest als USV fuer eine Mobilfunkbasisstation

    Energy Technology Data Exchange (ETDEWEB)

    Trachte, U.

    2008-07-01

    This article takes a look at the testing of a fuel-cell-based uninterruptible power supply for a cell-phone base station. The working principles of various types of fuel cell are examined and their areas of application are discussed. The use of polymer-electrolyte-membrane (PEM) fuel cells as a back-up power supply for a cell-phone base station was examined by the University of Applied Sciences in Lucerne, Switzerland. Several designs and models of fuel cells were examined. The installation of the cell-phone station is described and experience gained from the use of fuel cells in practice is presented and discussed.

  8. Characterization and Modeling of a Methanol Reforming Fuel Cell System

    DEFF Research Database (Denmark)

    Sahlin, Simon Lennart

    topologies is the Reformed Methanol Fuel Cell (RMFC) system that operates on a mix of methanol and water. The fuel is reformed with a steam reforming to a hydrogen rich gas, however with additional formation of Carbon Monoxide and Carbon Dioxide. High Temperature Polymer Electrolyte Membrane Fuel Cell (HT...... to heat up the steam reforming process. However, utilizing the excess hydrogen in the system complicates the RMFC system as the amount of hydrogen can vary depending on the fuel methanol supply, fuel cell load and the reformer gas composition. This PhD study has therefore been involved in investigating......Many fuel cells systems today are operated with compressed hydrogen which has great benefits because of the purity of the hydrogen and the relatively simple storage of the fuel. However, compressed hydrogen is stored in the range of 800 bar, which can be expensive to compress.One of the interesting...

  9. 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

  10. Direct hydrogen fuel cell systems for hybrid vehicles

    Science.gov (United States)

    Ahluwalia, Rajesh K.; Wang, X.

    Hybridizing a fuel cell system with an energy storage system offers an opportunity to improve the fuel economy of the vehicle through regenerative braking and possibly to increase the specific power and decrease the cost of the combined energy conversion and storage systems. Even in a hybrid configuration it is advantageous to operate the fuel cell system in a load-following mode and use the power from the energy storage system when the fuel cell alone cannot meet the power demand. This paper discusses an approach for designing load-following fuel cell systems for hybrid vehicles and illustrates it by applying it to pressurized, direct hydrogen, polymer-electrolyte fuel cell (PEFC) systems for a mid-size family sedan. The vehicle level requirements relative to traction power, response time, start-up time and energy conversion efficiency are used to select the important parameters for the PEFC stack, air management system, heat rejection system and the water management system.

  11. 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.)

  12. 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.

  13. Experimental study to distinguish the effects of methanol slip and water vapour on a high temperature PEM fuel cell at different operating conditions

    DEFF Research Database (Denmark)

    Thomas, Sobi; Vang, Jakob Rabjerg; Araya, Samuel Simon

    2017-01-01

    The objective of this paper is to separate out the effects of methanol and water vapour on a high temperature polymer electrolyte membrane fuel cell under different temperatures (160°C and 180°C) and current densities (0.2Acm-2, 0.4Acm-2 and 0.6Acm-2). The degradation rates at the different curre...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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...

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

    Science.gov (United States)

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

    2018-03-01

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

  20. Third International Fuel Cell Conference. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-30

    The Third International Fuel Cell Conference was held on November 30 to December 3, 1999 in City of Nagoya. A total of 139 papers, including those for plenary, sectional and poster cessions, were presented. In the plenary session, US's DOE presented fuel cell power plant development in the United States, EC fuel cells in perspective and fifth European framework programme, and Japan overview of the New Sunshine Program. In the polymer electrolyte fuel cells sessions, 23 papers were presented, including current status of commercialization and PEMFC systems developed by Toshiba. In the phosphoric acid fuel cells session, 6 papers were presented, including field test results and market developments. In the molten carbonate fuel cells session, 24 papers were presented, including development of 1,000kW MCFC power plant. In the solid oxide fuel cells session, 20 papers were presented, including 100kW SOFC field test results. The other topics include market analysis and fuel processes. (NEDO)

  1. Novel materials for fuel cells operating on liquid fuels

    Directory of Open Access Journals (Sweden)

    César A. C. Sequeira

    2017-05-01

    Full Text Available Towards commercialization of fuel cell products in the coming years, the fuel cell systems are being redefined by means of lowering costs of basic elements, such as electrolytes and membranes, electrode and catalyst materials, as well as of increasing power density and long-term stability. Among different kinds of fuel cells, low-temperature polymer electrolyte membrane fuel cells (PEMFCs are of major importance, but their problems related to hydrogen storage and distribution are forcing the development of liquid fuels such as methanol, ethanol, sodium borohydride and ammonia. In respect to hydrogen, methanol is cheaper, easier to handle, transport and store, and has a high theoretical energy density. The second most studied liquid fuel is ethanol, but it is necessary to note that the highest theoretically energy conversion efficiency should be reached in a cell operating on sodium borohydride alkaline solution. It is clear that proper solutions need to be developed, by using novel catalysts, namely nanostructured single phase and composite materials, oxidant enrichment technologies and catalytic activity increasing. In this paper these main directions will be considered.

  2. The Effect of Lithium Iodide to the Properties of Carboxymethyl κ-Carrageenan/Carboxymethyl Cellulose Polymer Electrolyte and Dye-Sensitized Solar Cell Performance

    Directory of Open Access Journals (Sweden)

    Siti Rudhziah Che Balian

    2016-05-01

    Full Text Available This study was undertaken to investigate the solid biopolymer electrolytes based on a carboxymethyl κ-carrageenan/carboxymethyl cellulose blend complexed with lithium iodide of various weight ratios. The complexation of the doping salt with the polymer blend was confirmed by Fourier transform infrared spectroscopy. Ionic conductivity of the film was determined by impedance spectroscopy in the frequency range of 10 Hz to 4 MHz and in the temperature range of 303–338 K. The ionic conductivity increased with the increase in lithium iodide concentration as well as temperature. The membrane comprising 30 wt % of lithium iodide was found to give the highest conductivity of 3.89 × 10−3 S·cm−1 at room temperature. The increase in conductivity was associated with the increase in the number as well as the mobility of the charge carries. The conductivity increase with temperature followed the Vogel–Tamman–Fulcher model. The fabricated dye-sensitive solar cell, FTO/TiO2-dye/CMKC/CMCE-LiI (30 wt % +I2/Pt exhibited the highest conversion efficiency of 0.11% at a light intensity of 100 mW·cm−2. This indicated that the biopolymer blend electrolyte system has potential for use in dye-sensitized solar cells.

  3. Phosphoric acid doped polybenzimidazole membranes: Physiochemical characterization and fuel cell applications [PEM fuel cells

    DEFF Research Database (Denmark)

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

    2001-01-01

    A polymer electrolyte membrane fuel cell operational at temperatures around 150-200 degrees C is desirable for fast electrode kinetics and high tolerance to fuel impurities. For this purpose polybenzimidazole (PBI) membranes have been prepared and H/sub 3/PO/sub 4/-doped in a doping range from 300...... doping level. At 160 degrees C a conductivity as high as 0.13 S cm/sup -1/ is obtained for membranes of high doping levels. Mechanical strength measurements show, however, that a high acid doping level results in poor mechanical properties. At operational temperatures up to 190 degrees C, fuel cells...... based on this polymer membrane have been tested with both hydrogen and hydrogen containing carbon monoxide....

  4. Water balance simulations of a polymer-electrolyte membrane fuel cell using a two-fluid model

    DEFF Research Database (Denmark)

    Berning, Torsten; Odgaard, M.; Kær, Søren Knudsen

    2011-01-01

    the predominant transport mechanism is diffusion. Consequently, operating conditions with a high net water transport from anode to cathode should be avoided as it is important to keep the cathode catalyst layer well humidified in order to prevent high protonic losses. Addition of the micro-porous layer did...

  5. Lattice Boltzmann simulations of water transport in gas diffusion layer of a polymer electrolyte membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Liang; Cheng, Ping [Ministry of Education Key Laboratory of Power Machinery and Engineering, School of Mechanical Engineering, Shanghai Jiaotong University, DongChuan Road 800, Shanghai 200240 (China)

    2010-06-15

    The effect of wettability on water transport dynamics in gas diffusion layer (GDL) is investigated by simulating water invasion in an initially gas-filled GDL using the multiphase free-energy lattice Boltzmann method (LBM). The results show that wettability plays a significant role on water saturation distribution in two-phase flow in the uniform wetting GDL. For highly hydrophobicity, the water transport falls in the regime of capillary fingering, while for neutral wettability, water transport exhibits the characteristic of stable displacement, although both processes are capillary force dominated flow with same capillary numbers. In addition, the introduction of hydrophilic paths in the GDL leads the water to flow through the hydrophilic pores preferentially. The resulting water saturation distributions show that the saturation in the GDL has little change after water breaks through the GDL, and further confirm that the selective introduction of hydrophilic passages in the GDL would facilitate the removal of liquid water more effectively, thus alleviating the flooding in catalyst layer (CL) and GDL. The LBM approach presented in this study provides an effective tool to investigate water transport phenomenon in the GDL at pore-scale level with wettability distribution taken into consideration. (author)

  6. Electrochemical stability and postmortem studies of Pt/SiC catalysts for polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Stamatin, Serban Nicolae; Spéder, József; Dhiman, Rajnish

    2015-01-01

    In the presented work, the electrochemical stability of platinized silicon carbide is studied. Postmortem transmission electron microscopy and X-ray photoelectron spectroscopy were used to document the change in the morphology and structure upon potential cycling of Pt/SiC catalysts. Two differen......, silicon carbide undergoes at least mild oxidation if not even silicon leaching....

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

    KAUST Repository

    Arashi, Takuya

    2014-09-01

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

  8. New improved polymer electrolyte membrane for PEM fuel cell. Final Report, 1. Documentation synthesis and test of proton exchange membranes

    Energy Technology Data Exchange (ETDEWEB)

    Lund, Peter B.; Dimitrov, I. (IRD A/S, Svendborg (Denmark)); Jankova, K.; Hvilsted, S. (Technical Univ. of Denmark. Chemical Engineering, Kgs. Lyngby (Denmark)); Juul Larsen, M.; Skou, E. (Univ. of Southern Denmark. Institute of Chemical Engineering, Biotechnology and Environmental Technology, Odense (Denmark))

    2010-07-15

    A novel concept for preparation of sulfonate containing fluorinated block co-polystyrenes have been developed based on initial ATRP of fluorinated styrene monomers. The strategy depends on well defined macroinitiatiors that after conversion to block copolymers can be post functionalized in two steps with propyl sulfonate groups in different ratios. Thermal investigations have demonstrated that addition of a PFS block to the sulfonate containing block improves the materials' thermal stability. (Author)

  9. Effect of porosity heterogeneity on the permeability and tortuosity of gas diffusion layers in polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Nabovati, Aydin; Hinebaugh, James; Bazylak, Aimy; Amon, Cristina H.

    2014-02-01

    In this paper, we study the effect of porosity heterogeneity on the bulk hydrodynamic properties (permeability and tortuosity) of simulated gas diffusion layers (GDLs). The porosity distributions of the heterogeneous reconstructed samples are similar to those previously reported in the literature for Toray TGP-H 120™ GDLs. We use the lattice Boltzmann method to perform pore-level flow simulations in the reconstructed GDL samples. Using the results of pore-level simulations, the effect of porosity distribution is characterized on the predicted in- and cross-plane permeability and tortuosity. It was found that porosity heterogeneity causes a higher in-plane permeability and lower in-plane tortuosity, while the effect is opposite in the cross-plane direction, that is a lower cross-plane permeability and a higher cross-plane tortuosity. We further investigate the effect of adding poly-tetra-fluoro-ethylene (PTFE) & binder material to the reconstructed GDL samples. Three fiber volume percentages of 50, 75, and 100% are considered. Overall, increasing the fiber volume percentage reduces the predicted in- and cross-plane permeability and tortuosity values. A previously reported relationship for permeability of fibrous materials is fitted to the predicted permeability values, and the magnitude of the fitting parameter is reported as a function of fiber volume percentage.

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

    KAUST Repository

    Arashi, Takuya; Seo, Jeongsuk; Takanabe, Kazuhiro; Kubota, Jun; Domen, Kazunari

    2014-01-01

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

  11. Experimental investigation on a turbine compressor for air supply system of a fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Masayasu [Sumitomo Heavy Industries, Ltd., Yokosuka (Japan); Tsuchiyama, Syozo [Shipbuilding Research Association, Minato-ku, Tokyo (Japan)

    1996-12-31

    This report covers part of a joint study on a PEFC propulsion system for surface ships, summarized in a presentation to this Seminar, entitled {open_quotes}Study on a Polymer Electrolyte Fuel Cell (PEFC) Propulsion System for Surface Ships{close_quotes}, and which envisages application to a 1,500 DWT cargo vessel. The aspect treated here concerns a study on the air supply system for the PEFC, with particular reference to system components.

  12. Fuel cells - from the laboratory to the road

    Energy Technology Data Exchange (ETDEWEB)

    Fronk, M.H. [Delphi Energy and Engine Management Systems, Rochester, NY (United States)

    1996-12-31

    The polymer electrolyte membrane (PEM) Fuel Cell faces stiff competition from existing automotive powerplants and other Hybrid APUs. To be successful, the Fuel Cell will have to demonstrate real customer advantages such as fuel economy and emissions. The PEM technology has an inherent advantage over other powerplants in both thermal efficiency and emission performance, and as such fits in very well with the future regulations that strive to clean up the environment. In addition, it will need to be cost competitive and provide acceptable performance. The majority of development activity on PEM Fuel Cells to date has concentrated primarily in the area of Stack refinement and optimization with improvements coming in higher power densities and higher specific power. To make the Fuel Cell compatible with an automotive environment the entire system will need to be analyzed, understood, and then engineered to work together in an efficient manner.

  13. 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

  14. 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

  15. U.S. Clean Energy Hydrogen and Fuel Cell Technologies: A Competitiveness Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fullenkamp, Patrick [Westside Industrial Retention & Expansion Network, Cleveland, OH (United States); Holody, Diane [Westside Industrial Retention & Expansion Network, Cleveland, OH (United States); James, Brian [Strategic Analysis, Inc., Arlington, VA (United States); Houchins, Cassidy [Strategic Analysis, Inc., Arlington, VA (United States); Wheeler, Douglas [DJW Technology, Dublin, OH (United States); Hart, David [E4tech, London (United Kingdom); Lehner, Franz [E4tech, London (United Kingdom)

    2017-10-10

    The objectives of this project are a 1) Global Competitiveness Analysis of hydrogen and fuel cell systems and components manufactured including 700 bar compressed hydrogen storage system in the U.S., Europe, Asia, and other key areas to be identified to determine the global cost leaders, the best current manufacturing processes, the key factors determining competitiveness, and the potential means of cost reductions; and an 2) Analysis to assess the status of global hydrogen and fuel cell markets. The analysis of units, megawatts by country and by application will focus on polymer electrolyte membrane (PEM) fuel cell systems (automotive and stationary).

  16. 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.

  17. 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

  18. 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)

  19. 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.

  20. 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)

  1. Fuel Exhaling Fuel Cell.

    Science.gov (United States)

    Manzoor Bhat, Zahid; Thimmappa, Ravikumar; Devendrachari, Mruthyunjayachari Chattanahalli; Kottaichamy, Alagar Raja; Shafi, Shahid Pottachola; Varhade, Swapnil; Gautam, Manu; Thotiyl, Musthafa Ottakam

    2018-01-18

    State-of-the-art proton exchange membrane fuel cells (PEMFCs) anodically inhale H 2 fuel and cathodically expel water molecules. We show an unprecedented fuel cell concept exhibiting cathodic fuel exhalation capability of anodically inhaled fuel, driven by the neutralization energy on decoupling the direct acid-base chemistry. The fuel exhaling fuel cell delivered a peak power density of 70 mW/cm 2 at a peak current density of 160 mA/cm 2 with a cathodic H 2 output of ∼80 mL in 1 h. We illustrate that the energy benefits from the same fuel stream can at least be doubled by directing it through proposed neutralization electrochemical cell prior to PEMFC in a tandem configuration.

  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. On the efficiency of an advanced automotive fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, F.N.; Freunberger, S.A.; Reum, M.; Tsukada, A.; Dietrich, P. [Paul Scherrer Institut, Electrochemistry Laboratory, CH-5232 Villigen PSI (Switzerland); Paganelli, G.; Delfino, A. [Conception et Developpement Michelin, Route Andre-Piller 30, CH-1762 Givisiez (Switzerland)

    2007-04-15

    Efficiency is the key parameter for the application of fuel cells in automotive applications. The efficiency of a hydrogen/oxygen polymer electrolyte fuel cell system is analyzed and compared to hydrogen/air systems. The analysis is performed for the tank to electric power chain. Furthermore, the additional energy required for using pure oxygen as a second fuel is analyzed and included in the calculation. The results show that if hydrogen is produced from primary fossil energy carriers, such as natural gas and pure oxygen needs to be obtained by a conventional process; the fuel to electric current efficiency is comparable for hydrogen/oxygen and hydrogen/air systems. However, if hydrogen and oxygen are produced by the splitting of water, i.e., by electrolysis or by a thermochemical process, the fuel to electric current efficiency for the hydrogen/oxygen system is clearly superior. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  4. Fuel cells as renewable energy sources

    International Nuclear Information System (INIS)

    Cacciola, G.; Passalacqua, E.

    2001-01-01

    The technology level achieved in fuel cell (FC) systems in the last years has significantly increased the interest of various manufacturing industries engaged in energy production and distribution even under the perspectives that this technology could provide. Today, the fuel cells (FCs) can supply both electrical and thermal energy without using moving parts and with a high level of affordability with respect to the conventional systems. FCs can utilise every kind of fuel such as hydrocarbons, hydrogen available from the water through renewable sources (wind, solar energy), alcohol etc. Thus, they may find application in many field ranging from energy production in large or small plants to the cogeneration systems for specific needs such as for residential applications, hospitals, industries, electric vehicles and portable power sources. Low temperature polymer electrolyte fuel cells (PEFC, DMFC) are preferred for application in the field of transportation and portable systems. The CNR-ITAE research activity in this field concerns the development of technologies, materials and components for the entire system: electrocatalysts, conducting supports, electrolytes, manufacturing technologies for the electrodes-electrolyte assemblies and the attainment of fuel cells with high power densities. Furthermore, some activities have been devoted to the design and realisation of PEFC fuel cell prototypes with rated power lower than I kW for stationary and mobile applications [it

  5. 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.

  6. Durability of PEM Fuel Cell Membranes

    Science.gov (United States)

    Huang, Xinyu; Reifsnider, Ken

    Durability is still a critical limiting factor for the commercialization of polymer electrolyte membrane (PEM) fuel cells, a leading energy conversion technology for powering future hydrogen fueled automobiles, backup power systems (e.g., for base transceiver station of cellular networks), portable electronic devices, etc. Ionic conducting polymer (ionomer) electrolyte membranes are the critical enabling materials for the PEM fuel cells. They are also widely used as the central functional elements in hydrogen generation (e.g., electrolyzers), membrane cell for chlor-alkali production, etc. A perfluorosulfonic acid (PFSA) polymer with the trade name Nafion® developed by DuPont™ is the most widely used PEM in chlor-alkali cells and PEM fuel cells. Similar PFSA membranes have been developed by Dow Chemical, Asahi Glass, and lately Solvay Solexis. Frequently, such membranes serve the dual function of reactant separation and selective ionic conduction between two otherwise separate compartments. For some applications, the compromise of the "separation" function via the degradation and mechanical failure of the electrolyte membrane can be the life-limiting factor; this is particularly the case for PEM in hydrogen/oxygen fuel cells.

  7. 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...

  8. Fuel Cells

    DEFF Research Database (Denmark)

    Smith, Anders; Pedersen, Allan Schrøder

    2014-01-01

    Fuel cells have been the subject of intense research and development efforts for the past decades. Even so, the technology has not had its commercial breakthrough yet. This entry gives an overview of the technological challenges and status of fuel cells and discusses the most promising applications...... of the different types of fuel cells. Finally, their role in a future energy supply with a large share of fluctuating sustainable power sources, e.g., solar or wind, is surveyed....

  9. The mass balance of a Proton Exchange Membrane Fuel Cell (PEMFC)

    International Nuclear Information System (INIS)

    Miloud, S.; Kamaruzzaman Sopian; Wan Ramli Wan Daud

    2006-01-01

    A Proton Exchange Membrane Fuel Cell (PEMFC), operating at low temperature uses a simple chemical process to combine hydrogen and oxygen into water, producing electric current and heat during the electrochemical reaction. This work concern on the theoretical consideration of the mass balance has been evaluated to predict the mass flow rate of the both gases (hydrogen/oxygen), the water mass balance, and the heat transfer in order to design a single cell PEMFC stack with a better flow field distributor on the performance of Polymer Electrolyte membrane fuel cells

  10. Water Balance Simulations of a PEM Fuel Cell Using a Two-Fluid Model

    DEFF Research Database (Denmark)

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

    2010-01-01

    A previously published computational multi-phase model of a polymer-electrolyte membrane fuel cell has been extended in order to account for the anode side and the electrolyte membrane. The model has been applied to study the water balance of a fuel cell during operation under various humidificat...... net water transport coefficient. Thus we can reduce flooding at the cathode and may obtain improved cell performance due to a better humidified membrane. The results also suggest that membrane dehydration may occur at either anode or cathode depending on the net water transport....

  11. Fuel quality issues in stationary fuel cell systems.

    Energy Technology Data Exchange (ETDEWEB)

    Papadias, D.; Ahmed, S.; Kumar, R. (Chemical Sciences and Engineering Division)

    2012-02-07

    Fuel cell systems are being deployed in stationary applications for the generation of electricity, heat, and hydrogen. These systems use a variety of fuel cell types, ranging from the low temperature polymer electrolyte fuel cell (PEFC) to the high temperature solid oxide fuel cell (SOFC). Depending on the application and location, these systems are being designed to operate on reformate or syngas produced from various fuels that include natural gas, biogas, coal gas, etc. All of these fuels contain species that can potentially damage the fuel cell anode or other unit operations and processes that precede the fuel cell stack. These detrimental effects include loss in performance or durability, and attenuating these effects requires additional components to reduce the impurity concentrations to tolerable levels, if not eliminate the impurity entirely. These impurity management components increase the complexity of the fuel cell system, and they add to the system's capital and operating costs (such as regeneration, replacement and disposal of spent material and maintenance). This project reviewed the public domain information available on the impurities encountered in stationary fuel cell systems, and the effects of the impurities on the fuel cells. A database has been set up that classifies the impurities, especially in renewable fuels, such as landfill gas and anaerobic digester gas. It documents the known deleterious effects on fuel cells, and the maximum allowable concentrations of select impurities suggested by manufacturers and researchers. The literature review helped to identify the impurity removal strategies that are available, and their effectiveness, capacity, and cost. A generic model of a stationary fuel-cell based power plant operating on digester and landfill gas has been developed; it includes a gas processing unit, followed by a fuel cell system. The model includes the key impurity removal steps to enable predictions of impurity breakthrough

  12. 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

  13. Bio-inspired Construction of Advanced Fuel Cell Cathode with Pt Anchored in Ordered Hybrid Polymer Matrix

    OpenAIRE

    Xia, Zhangxun; Wang, Suli; Jiang, Luhua; Sun, Hai; Liu, Shuang; Fu, Xudong; Zhang, Bingsen; Sheng Su, Dang; Wang, Jianqiang; Sun, Gongquan

    2015-01-01

    The significant use of platinum for catalyzing the cathodic oxygen reduction reactions (ORRs) has hampered the widespread use of polymer electrolyte membrane fuel cells (PEMFCs). The construction of well-defined electrode architecture in nanoscale with enhanced utilization and catalytic performance of Pt might be a promising approach to address such barrier. Inspired by the highly efficient catalytic processes in enzymes with active centers embedded in charge transport pathways, here we demon...

  14. Formation of Platinum Catalyst on Carbon Black Using an In‐Liquid Plasma Method for Fuel Cells

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Show

    2017-01-01

    Full Text Available Platinum (Pt catalyst was formed on the surface of carbon black using an in‐liquid plasma method. The formed Pt catalyst showed the average particle size of 4.1 nm. This Pt catalyst was applied to a polymer electrolyte membrane fuel cell (PEMFC. The PEMFC showed an open voltage of 0.85 V and a maximum output power density of 216 mW/cm2.

  15. 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...

  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. PORTABLE PEM FUEL CELL SYSTEM: WATER AND HEAT MANAGEMENT

    Directory of Open Access Journals (Sweden)

    SITI NAJIBAH ABD RAHMAN

    2016-07-01

    Full Text Available Portable polymer electrolyte membrane (PEM fuel cell power generator is a PEM fuel cell application that is used as an external charger to supply the demand for high energy. Different environments at various ambient temperatures and humidity levels affect the performance of PEM fuel cell power generators. Thermal and water management in portable PEM fuel cells are a critical technical barrier for the commercialization of this technology. The size and weight of the portable PEM fuel cells used for thermal and water management systems that determine the performance of portable PEM fuel cells also need to be considered. The main objective of this paper review was to determine the importance of water and thermal management systems in portable PEM fuel cells. Additionally, this review investigated heat transfer and water transport in PEM fuel cells. Given that portable PEM fuel cells with different powers require different thermal and water management systems, this review also discussed and compared management systems for low-, medium-, and high-power portable PEM fuel cells.

  18. Fuel cells

    NARCIS (Netherlands)

    Veen, van J.A.R.; Janssen, F.J.J.G.; Santen, van R.A.

    1999-01-01

    The principles and present-day embodiments of fuel cells are discussed. Nearly all cells are hydrogen/oxygen ones, where the hydrogen fuel is usually obtained on-site from the reforming of methane or methanol. There exists a tension between the promise of high efficiency in the conversion of

  19. Fuel cells. Pt. 1; Celle a combustibile. Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Campanari, S; Macchi, E [Milan Politecnico (Italy). Dip. di Energetica

    1999-01-01

    Direct conversion of chemical energy into electricity (without intermediate heat generation) is a long-established method to improve the efficiency of power generation, as well as to reduce polluting emissions from thermal plants. The origins of fuel cells, as well as their operating principles, are dealt with. Then, various types of cells are taken into consideration, on the basis of both their characteristics and the operating principles of electrolytes. Finally, structure and operation of Polymer Electrolyte Membrane Fuel Cells (PEMFC), Alkaline Fuel Cells (AFC) and Phosphoric Acid Fuel Cells (PAFC) are described. [Italiano] La conversione diretta dell`energia chimica del combustibile in energia elettrica, senza passare attraverso la produzione di calore, rappresenta una via ormai ampiamente collaudata per migliorare l`efficienza della produzione di energia elettrica e per contenere le emissioni generate dagli impianti termoelettrici. L`articolo, dopo una breve presentazione della storia dello sviluppo nel tempo delle celle a combustibile, espone i principi di funzionamento delle stesse. Si esaminano quindi i vari tipi di cella a partire dalle caratteristiche e dalle modalita` di funzionamento degli elettroliti che ne definiscono la classificazione. Successivamente vengono illustrate le caratteristiche costruttive e funzionali delle celle ad elettrolita polimerico (PEMFC), delle celle alcaline (AFC) e delle celle ad acido fosforico (PAFC).

  20. 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.

  1. Power generation in fuel cells using liquid methanol and hydrogen peroxide

    Science.gov (United States)

    Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor); Chun, William (Inventor)

    2002-01-01

    The invention is directed to an encapsulated fuel cell including a methanol source that feeds liquid methanol (CH.sub.3 OH) to an anode. The anode is electrical communication with a load that provides electrical power. The fuel cell also includes a hydrogen peroxide source that feeds liquid hydrogen peroxide (H.sub.2 O.sub.2) to the cathode. The cathode is also in communication with the electrical load. The anode and cathode are in contact with and separated by a proton-conducting polymer electrolyte membrane.

  2. Near-ambient solid polymer fuel cell

    Science.gov (United States)

    Holleck, G. L.

    1993-01-01

    Fuel cells are extremely attractive for extraterrestrial and terrestrial applications because of their high energy conversion efficiency without noise or environmental pollution. Among the various fuel cell systems the advanced polymer electrolyte membrane fuel cells based on sulfonated fluoropolymers (e.g., Nafion) are particularly attractive because they are fairly rugged, solid state, quite conductive, of good chemical and thermal stability and show good oxygen reduction kinetics due to the low specific adsorption of the electrolyte on the platinum catalyst. The objective of this program is to develop a solid polymer fuel cell which can efficiently operate at near ambient temperatures without ancillary components for humidification and/or pressurization of the fuel or oxidant gases. During the Phase 1 effort we fabricated novel integral electrode-membrane structures where the dispersed platinum catalyst is precipitated within the Nafion ionomer. This resulted in electrode-membrane units without interfacial barriers permitting unhindered water diffusion from cathode to anode. The integral electrode-membrane structures were tested as fuel cells operating on H2 and O2 or air at 1 to 2 atm and 10 to 50 C without gas humidification. We demonstrated that cells with completely dry membranes could be self started at room temperature and subsequently operated on dry gas for extended time. Typical room temperature low pressure operation with unoptimized electrodes yielded 100 mA/cm(exp 2) at 0.5V and maximum currents over 300 mA/cm(exp 2) with low platinum loadings. Our results clearly demonstrate that operation of proton exchange membrane fuel cells at ambient conditions is feasible. Optimization of the electrode-membrane structure is necessary to assess the full performance potential but we expect significant gains in weight and volume power density for the system. The reduced complexity will make fuel cells also attractive for smaller and portable power supplies and as

  3. Cost reductions of fuel cells for transport applications: fuel processing options

    Energy Technology Data Exchange (ETDEWEB)

    Teagan, W P; Bentley, J; Barnett, B [Arthur D. Little, Inc., Cambridge, MA (United States)

    1998-03-15

    The highly favorable efficiency/environmental characteristics of fuel cell technologies have now been verified by virtue of recent and ongoing field experience. The key issue regarding the timing and extent of fuel cell commercialization is the ability to reduce costs to acceptable levels in both stationary and transport applications. It is increasingly recognized that the fuel processing subsystem can have a major impact on overall system costs, particularly as ongoing R and D efforts result in reduction of the basic cost structure of stacks which currently dominate system costs. The fuel processing subsystem for polymer electrolyte membrane fuel cell (PEMFC) technology, which is the focus of transport applications, includes the reformer, shift reactors, and means for CO reduction. In addition to low cost, transport applications require a fuel processor that is compact and can start rapidly. This paper describes the impact of factors such as fuel choice operating temperature, material selection, catalyst requirements, and controls on the cost of fuel processing systems. There are fuel processor technology paths which manufacturing cost analyses indicate are consistent with fuel processor subsystem costs of under $150/kW in stationary applications and $30/kW in transport applications. As such, the costs of mature fuel processing subsystem technologies should be consistent with their use in commercially viable fuel cell systems in both application categories. (orig.)

  4. Fuel cells

    International Nuclear Information System (INIS)

    Niederdoeckl, J.

    2001-01-01

    Europe has at present big hopes on the fuel cells technology, in comparison with other energy conversion technologies, this technology has important advantages, for example: high efficiency, very low pollution and parallel use of electric and thermal energy. Preliminary works for fuel cells developing and its commercial exploitation are at full speed; until now the European Union has invested approx. 1.7 billion Schillings, 60 relevant projects are being executed. The Austrian industry is interested in applying this technique to drives, thermal power stations and the miniature fuel cells as replacement of batteries in electronic products (Notebooks, mobile telephones, etc.). A general description of the historic development of fuel cells including the main types is given as well as what is the situation in Austria. (nevyjel)

  5. 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

  6. Materials Challenges for Automotive PEM Fuel Cells

    Science.gov (United States)

    Gasteiger, Hubert

    2004-03-01

    Over the past few years, significant R efforts aimed at meeting the challenging cost and performance targets required for the use of Polymer Electrolyte Membrane (PEM) fuel cells in automotive applications. Besides engineering advances in bipolar plate materials and design, the optimization of membrane-electrode assemblies (MEAs) was an important enabler in reducing the cost and performance gaps towards commercial viability for the automotive market. On the one hand, platinum loadings were reduced from several mgPt/cm2MEA [1] to values of 0.5-0.6 mgPt/cm2MEA in current applications and loadings as low as 0.25 mgPt/cm2MEA have been demonstrated on the research level [2]. On the other hand, implementation of thin membranes (20-30 micrometer) [3, 4] as well as improvements in diffusion medium materials, essentially doubled the achievable power density of MEAs to ca. 0.9 W/cm2MEA (at 0.65 V) [5], thereby not only reducing the size of a PEMFC fuel cell system, but also reducing its overall materials cost (controlled to a large extent by membrane and Pt-catalyst cost). While this demonstrated a clear path towards automotive applications, a renewed focus of R efforts is now required to develop materials and fundamental materials understanding to assure long-term durability of PEM fuel cells. This presentation therefore will discuss the state-of-the-art knowledge of catalyst, catalyst-support, and membrane degradation mechanisms. In the area of Pt-catalysts, experience with phosphoric acid fuel cells (PAFCs) has shown that platinum sintering leads to long-term performance losses [6]. While this is less critical at the lower PEMFC operating temperatures (200C), very little is known about the dependence of Pt-sintering on temperature, cell voltage, and catalyst type (i.e., Pt versus Pt-alloys) and will be discussed here. Similarly, carbon-support corrosion can contribute significantly to voltage degradation in PAFCs [7], and even in the PEMFC environment more corrosion

  7. Fuel cells:

    DEFF Research Database (Denmark)

    Sørensen, Bent

    2013-01-01

    A brief overview of the progress in fuel cell applications and basic technology development is presented, as a backdrop for discussing readiness for penetration into the marketplace as a solution to problems of depletion, safety, climate or environmental impact from currently used fossil and nucl......A brief overview of the progress in fuel cell applications and basic technology development is presented, as a backdrop for discussing readiness for penetration into the marketplace as a solution to problems of depletion, safety, climate or environmental impact from currently used fossil...... and nuclear fuel-based energy technologies....

  8. XAS Investigations of PEM Fuel Cells

    Science.gov (United States)

    Roth, Christina; Ramaker, David E.

    Polymer-electrolyte membrane (PEM) fuel cells are still far from an area-wide market launch due in part to long-term stability, reliability and cost issues. A more detailed knowledge of the underlying reaction mechanisms is expected to further their application, as it would allow for the design of tailor-made catalysts. However, this will only be possible by complementing traditional in situ studies on single-crystals in electrochemical cells with more sophisticated metal/electrolyte interfacial studies by novel spectroscopic methodologies, which can provide complementary insights into the behaviour of commercial catalysts under real fuel cell operating conditions. This review will focus on the advances of Xray absorption spectroscopy (XAS) in applied fuel cell research utilizing several examples. XAS enables both the nanoparticle morphology and the adsorbate coverage and binding site to be investigated with just one technique. The latter is possible when complementing the conventional extended X-ray absorption fine structure (EXAFS) analysis with the more novel Δμ XANES approach.

  9. 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

  10. 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.

  11. 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)

  12. 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

  13. 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

  14. Development and experimental characterization of a fuel cell powered aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, Thomas H.; Moffitt, Blake A.; Mavris, Dimitri N.; Parekh, David E. [Georgia Institute of Technology, Atlanta, GA 30332-0405 (United States)

    2007-09-27

    This paper describes the characteristics and performance of a fuel cell powered unmanned aircraft. The aircraft is novel as it is the largest compressed hydrogen fuel cell powered airplane built to date and is currently the only fuel cell aircraft whose design and test results are in the public domain. The aircraft features a 500 W polymer electrolyte membrane fuel cell with full balance of plant and compressed hydrogen storage incorporated into a custom airframe. Details regarding the design requirements, implementation and control of the aircraft are presented for each major aircraft system. The performances of the aircraft and powerplant are analyzed using data from flights and laboratory tests. The efficiency and component power consumption of the fuel cell propulsion system are measured at a variety of flight conditions. The performance of the aircraft powerplant is compared to other 0.5-1 kW-scale fuel cell powerplants in the literature and means of performance improvement for this aircraft are proposed. This work represents one of the first studies of fuel cell powered aircraft to result in a demonstration aircraft. As such, the results of this study are of practical interest to fuel cell powerplant and aircraft designers. (author)

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Thermal Design for Extra-Terrestrial Regenerative Fuel Cell System

    Science.gov (United States)

    Gilligan, R.; Guzik, M.; Jakupca, I.; Bennett, W.; Smith, P.; Fincannon, J.

    2017-01-01

    The Advanced Exploration Systems (AES) Advanced Modular Power Systems (AMPS) Project is investigating different power systems for various lunar and Martian mission concepts. The AMPS Fuel Cell (FC) team has created two system-level models to evaluate the performance of regenerative fuel cell (RFC) systems employing different fuel cell chemistries. Proton Exchange Membrane fuel cells PEMFCs contain a polymer electrolyte membrane that separates the hydrogen and oxygen cavities and conducts hydrogen cations (protons) across the cell. Solid Oxide fuel cells (SOFCs) operate at high temperatures, using a zirconia-based solid ceramic electrolyte to conduct oxygen anions across the cell. The purpose of the modeling effort is to down select one fuel cell chemistry for a more detailed design effort. Figures of merit include the system mass, volume, round trip efficiency, and electrolyzer charge power required. PEMFCs operate at around 60 C versus SOFCs which operate at temperatures greater than 700 C. Due to the drastically different operating temperatures of the two chemistries the thermal control systems (TCS) differ. The PEM TCS is less complex and is characterized by a single pump cooling loop that uses deionized water coolant and rejects heat generated by the system to the environment via a radiator. The solid oxide TCS has its own unique challenges including the requirement to reject high quality heat and to condense the steam produced in the reaction. This paper discusses the modeling of thermal control systems for an extraterrestrial RFC that utilizes either a PEM or solid oxide fuel cell.

  20. Dynamic fuel cell models and their application in hardware in the loop simulation

    Energy Technology Data Exchange (ETDEWEB)

    Lemes, Zijad; Maencher, H. [MAGNUM Automatisierungstechnik GmbH, Bunsenstr. 22, D-64293 Darmstadt (Germany); Vath, Andreas; Hartkopf, Th. [Technische Universitaet Darmstadt/Institut fuer Elektrische Energiewandlung, Landgraf-Georg-Str. 4, D-64283 Darmstadt (Germany)

    2006-03-21

    Currently, fuel cell technology plays an important role in the development of alternative energy converters for mobile, portable and stationary applications. With the help of physical based models of fuel cell systems and appropriate test benches it is possible to design different applications and investigate their stationary and dynamic behaviour. The polymer electrolyte membrane (PEM) fuel cell system model includes gas humidifier, air and hydrogen supply, current converter and a detailed stack model incorporating the physical characteristics of the different layers. In particular, the use of these models together with hardware in the loop (HIL) capable test stands helps to decrease the costs and accelerate the development of fuel cell systems. The interface program provides fast data exchange between the test bench and the physical model of the fuel cell or any other systems in real time. So the flexibility and efficiency of the test bench increase fundamentally, because it is possible to replace real components with their mathematical models. (author)

  1. Room temperature rechargeable polymer electrolyte batteries

    Energy Technology Data Exchange (ETDEWEB)

    Alamgir, M. [EIC Labs., Inc., Norwood, MA (United States); Abraham, K.M. [EIC Labs., Inc., Norwood, MA (United States)

    1995-03-01

    Polyacrylonitrile (PAN)- and poly(vinyl chloride) (PVC)-based Li{sup +}-conductive thin-film electrolytes have been found to be suitable in rechargeable Li and Li-ion cells. Li/Li{sub x}Mn{sub 2}O{sub y} and carbon/LiNiO{sub 2} cells fabricated with these electrolytes have demonstrated rate capabilities greater than the C-rate and more than 375 full depth cycles. Two-cell carbon/LiNiO{sub 2} bipolar batteries could be discharged at pulse currents as high as 50 mA/cm{sup 2}. (orig.)

  2. Fuel cell power trains for road traffic

    Science.gov (United States)

    Höhlein, Bernd; Biedermann, Peter; Grube, Thomas; Menzer, Reinhard

    Legal regulations, especially the low emission vehicle (LEV) laws in California, are the driving forces for more intensive technological developments with respect to a global automobile market. In the future, high efficient vehicles at very low emission levels will include low temperature fuel cell systems (e.g., polymer electrolyte fuel cell (PEFC)) as units of hydrogen-, methanol- or gasoline-based electric power trains. In the case of methanol or gasoline/diesel, hydrogen has to be produced on-board using heated steam or partial oxidation reformers as well as catalytic burners and gas cleaning units. Methanol could also be used for direct electricity generation inside the fuel cell (direct methanol fuel cell (DMFC)). The development potentials and the results achieved so far for these concepts differ extremely. Based on the experience gained so far, the goals for the next few years include cost and weight reductions as well as optimizations in terms of the energy management of power trains with PEFC systems. At the same time, questions of fuel specification, fuel cycle management, materials balances and environmental assessment will have to be discussed more intensively. On the basis of process engineering analyses for net electricity generation in PEFC-powered power trains as well as on assumptions for both electric power trains and vehicle configurations, overall balances have been carried out. They will lead not only to specific energy demand data and specific emission levels (CO 2, CO, VOC, NO x) for the vehicle but will also present data of its full fuel cycle (FFC) in comparison to those of FFCs including internal combustion engines (ICE) after the year 2005. Depending on the development status (today or in 2010) and the FFC benchmark results, the advantages of balances results of FFC with PEFC vehicles are small in terms of specific energy demand and CO 2 emissions, but very high with respect to local emission levels.

  3. Polarization Curve of a Non-Uniformly Aged PEM Fuel Cell

    Directory of Open Access Journals (Sweden)

    Andrei Kulikovsky

    2014-01-01

    Full Text Available We develop a semi-analytical model for polarization curve of a polymer electrolyte membrane (PEM fuel cell with distributed (aged along the oxygen channel MEA transport and kinetic parameters of the membrane–electrode assembly (MEA. We show that the curve corresponding to varying along the channel parameter, in general, does not reduce to the curve for a certain constant value of this parameter. A possibility to determine the shape of the deteriorated MEA parameter along the oxygen channel by fitting the model equation to the cell polarization data is demonstrated.

  4. Manufacturing technologies for direct methanol fuel cells (DMFCs)

    Energy Technology Data Exchange (ETDEWEB)

    Gluesen, Andreas; Mueller, Martin; Kimiaie, Nicola; Konradi, Irene; Mergel, Juergen; Stolten, Detlef [Forschungszentrum Juelich (Germany). Inst. of Energy Research - IEF-3: Fuel Cells

    2010-07-01

    Fuel cell research is focussing on increasing power density and lifetime and reducing costs of the whole fuel cell system. In order to reach these aims, it is necessary to develop appropriately designed components outgoing from high quality materials, a suitable manufacturing process and a well balanced system. To make use of the advantages that can be obtained by developing production technology, we are mainly improving the coating and assembling techniques for polymer electrolyte fuel cells, especially Direct Methanol Fuel Cells (DMFCs). Coating is used for making fuel cell electrodes as well as highly conductive contacts. Assembling is used to join larger components like membrane electrode assemblies (MEAs) and bipolar units consisting of flow fields and the separator plate, as well as entire stacks. On the one hand a reproducible manufacturing process is required to study fine differences in fuel cell performance affected by new materials or new designs. On the other hand a change in each parameter of the manufacturing process itself can change product properties and therefore affect fuel cell performance. As a result, gas diffusion electrodes (GDEs) are now produced automatically in square-meter batches, the hot-pressing of MEAs is a fully automated process and by pre-assembling the number of parts that have to be assembled in a stack was reduced by a factor of 10. These achievements make DMFC manufacturing more reproducible and less error-prone. All these and further developments of manufacturing technology are necessary to make DMFCs ready for the market. (orig.)

  5. HANARO Neutron Radiography Facility and Fuel Cell Research

    International Nuclear Information System (INIS)

    Kim, Taejoo

    2013-01-01

    Fuel cell which generates electric energy from hydrogen and oxygen is one of noticed renewable energy system because this has high efficiency and free from CO 2 . Especially, PEMFC (Polymer Electrolyte Membrane Fuel Cell) is focused by automotive companies because PEMFC, which has high power rate per volume and low operating temperature (60∼80), is suited due to the compact design and short start-up time. The water management is one of the most critical issues for fuel cell commercialization. In order to make a proper scheme for water management, thein formation of water distribution and behavior is very important. Neutron imaging is the best method to visualize the water at fuel cell and has been applied worldwide with qualitative and quantitative results. Because the NRF has large beam size (350Χ450mm 2 ) and relatively high neutron flux (2Χ107 n/cm 2 sec), it is suitable for large scale fuel cell research. Neutron imaging technique was used to investigate the water distribution and behavior in PEMFC under different operating conditions. The NRF has contributed the improvement of fuel cell performance and is one of the best choices for fuel cell study

  6. 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.

  7. 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.

  8. Investigation on preparing data collections related to new energy technology development. Fuel cells; Shin energy gijutsu kaihatsu kankei data shu sakusei chosa. Nenryo denchi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    With an objective to put data related to fuel cells systematically into order, related data were collected comprehensively. Reviewing large international conferences impresses dawn of commercialization in phosphoric acid fuel cells (PAFC), take-off of megawatt-class molten carbonate fuel cells (MCFC), and remarkable advancement in studies on solid oxide fuel cells (SOFC) and polymer electrolyte fuel cells (PEFC). The data collection may be compiled as follows: basic principles, features, operation principles, system configurations, utilization fields, and characteristics were summarized on fuel cell power generation systems using phosphoric acid, polymer, molten carbonate, solid oxide, and alkaline fuel cells; major installation examples in Japan and overseas countries were summarized; investigations were given on developing other fuel cells such as alkaline type and direct methanol type fuel cells; and marketability, subsidies operations in Japan, and states of policy implementation in the U.S.A. were investigated and put into order. 22 refs., 24 figs., 21 tabs.

  9. Simulation of a 250 kW diesel fuel processor/PEM fuel cell system

    Science.gov (United States)

    Amphlett, J. C.; Mann, R. F.; Peppley, B. A.; Roberge, P. R.; Rodrigues, A.; Salvador, J. P.

    Polymer-electrolyte membrane (PEM) fuel cell systems offer a potential power source for utility and mobile applications. Practical fuel cell systems use fuel processors for the production of hydrogen-rich gas. Liquid fuels, such as diesel or other related fuels, are attractive options as feeds to a fuel processor. The generation of hydrogen gas for fuel cells, in most cases, becomes the crucial design issue with respect to weight and volume in these applications. Furthermore, these systems will require a gas clean-up system to insure that the fuel quality meets the demands of the cell anode. The endothermic nature of the reformer will have a significant affect on the overall system efficiency. The gas clean-up system may also significantly effect the overall heat balance. To optimize the performance of this integrated system, therefore, waste heat must be used effectively. Previously, we have concentrated on catalytic methanol-steam reforming. A model of a methanol steam reformer has been previously developed and has been used as the basis for a new, higher temperature model for liquid hydrocarbon fuels. Similarly, our fuel cell evaluation program previously led to the development of a steady-state electrochemical fuel cell model (SSEM). The hydrocarbon fuel processor model and the SSEM have now been incorporated in the development of a process simulation of a 250 kW diesel-fueled reformer/fuel cell system using a process simulator. The performance of this system has been investigated for a variety of operating conditions and a preliminary assessment of thermal integration issues has been carried out. This study demonstrates the application of a process simulation model as a design analysis tool for the development of a 250 kW fuel cell system.

  10. Leading fuel cell projects ``PEM``; Brennstoffzellen-Leitprojekte ``PEM``

    Energy Technology Data Exchange (ETDEWEB)

    Isenberg, G

    1996-12-31

    Polymer electrolyte diaphragm fuel cells (PEMFC) are distinguished by high specific power densities which are necessary in the field of electrical drives, high efficiencies and no or very low emission of harmful substances, depending on the fuel. In the context of a leading project supported by BMBF, the development of improved and above all, more reasonably priced components for the PEMFC and the reforming of methanol is to work out the important technical basis for the subsequent economic conversion into a vehicle drive. (orig.) [Deutsch] Polymer-Elektrolyt-Membran-Brennstoffzellen (PEMFC) zeichnen sich durch hohe spezifische Leistungsdichten, wie sie im Bereich elektrischer Antriebe notwendig sind, hohe Wirkungsgrade und treibstoffabhaengig keine bzw. sehr niedrige Schadstoffemission aus. Im Rahmen eines BMBF-gefoerderten Leitprojekts sollen mit der Entwicklung verbesserter, vor allem kostenguenstiger Komponenten fuer die PEMFC und die Methanol-Reformierung wesentliche technologische Grundlagen fuer die anschliessende wirtschaftliche Umsetzung als Fahrzeugantrieb erarbeitet werden. (orig.)

  11. Hexadecacarbonylhexarhodium as a novel electrocatalyst for oxygen reduction and hydrogen oxidation in the presence of fuel cell contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Uribe-Godinez, J.; Jimenez-Sandoval, O. [Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional (Cinvestav), Unidad Queretaro. Apartado Postal 1-798, Queretaro, Qro. 76001 (Mexico); Hernandez-Castellanos, R. [Universidad Tecnologica de San Juan del Rio, Av. La Palma No. 125, Col. Vista Hermosa, San Juan del Rio, Qro. 76800 (Mexico)

    2010-11-01

    The electrocatalytic activity for oxygen reduction and hydrogen oxidation of a discrete metal carbonyl cluster with a well defined molecular and crystal structure, Rh{sub 6}(CO){sub 16}, is reported. The exchange current density of this compound for oxygen reduction is one order of magnitude higher than that of platinum, and its resistance degree to PEM fuel cell contaminants such as methanol and CO is as high as 2 mol L{sup -1} and 0.5%, respectively. These properties make the metal complex a potential alternative for use as electrode in polymer electrolyte membrane fuel cells. (author)

  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. 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.

  14. 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

  15. 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 prepa