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Sample records for fuel-cell membrane structure

  1. Corrugated Membrane Fuel Cell Structures

    Energy Technology Data Exchange (ETDEWEB)

    Grot, Stephen [President, Ion Power Inc.

    2013-09-30

    One of the most challenging aspects of traditional PEM fuel cell stacks is the difficulty achieving the platinum catalyst utilization target of 0.2 gPt/kWe set forth by the DOE. Good catalyst utilization can be achieved with state-of-the-art catalyst coated membranes (CCM) when low catalyst loadings (<0.3 mg/cm2) are used at a low current. However, when low platinum loadings are used, the peak power density is lower than conventional loadings, requiring a larger total active area and a larger bipolar plate. This results in a lower overall stack power density not meeting the DOE target. By corrugating the fuel cell membrane electrode structure, Ion Power?s goal is to realize both the Pt utilization targets as well as the power density targets of the DOE. This will be achieved by demonstrating a fuel cell single cell (50 cm2) with a twofold increase in the membrane active area over the geometric area of the cell by corrugating the MEA structure. The corrugating structure must be able to demonstrate the target properties of < 10 mOhm-cm2 electrical resistance at > 20 psi compressive strength over the active area, in combination with offering at least 80% of power density that can be achieved by using the same MEA in a flat plate structure. Corrugated membrane fuel cell structures also have the potential to meet DOE power density targets by essentially packaging more membrane area into the same fuel cell volume as compared to conventional stack constructions.

  2. Development of structured polymer electrolyte membranes for fuel cell applications

    Science.gov (United States)

    Gasa, Jeffrey

    The objective of this research was to explore structure-property relationships to develop the understanding needed for introduction of superior PEM materials. Polymer electrolyte membranes based on sulfonated poly(ether ketone ketone) (SPEKK) were fabricated using N-methyl pyrrolidone as casting solvent. The membranes were characterized in terms of properties that were relevant to fuel cell applications, such as proton conductivity, methanol permeability, and swelling properties, among others. It was found in this study that the proton conductivity of neat SPEKK membranes could reach the conductivity of commercial membranes such as NafionRTM. However, when the conductivity of SPEKK was comparable to NafionRTM, the swelling of SPEKK in water was quite excessive. The swelling problem was remedied by modifying the microstructure of SPEKK using different techniques. One of them involved blending of lightly sulfonated PEKK with highly acidic particles (sulfonated crosslinked polystyrene-SXLPS). Low sulfonation level of SPEKK was used to reduce the swelling of the membrane in water and the role of the highly acidic particles was to enhance the proton conductivity of the membrane. Because of the residual crystallinity in SPEKK with low sulfonation levels (IEC sulfone)) to act as mechanical reinforcement. It was found that miscibility behavior of the blends had a significant impact on the transport and swelling properties of these blends, which could be explained by the blend microstructure. The miscibility behavior was found to be strongly dependent on the sulfonation level of SPEKK. The conductivities of the blends were enhanced by as much as two orders of magnitude when the morphology was modified by electric field. The last approach was ionic crosslinking of the sulfonate groups in SPEKK using divalent cations, specifically barium ions. The crosslinking treatment has greatly improved the thermal stability of the membranes in both dry and wet conditions.

  3. Proton exchange membrane fuel cells

    CERN Document Server

    Qi, Zhigang

    2013-01-01

    Preface Proton Exchange Membrane Fuel CellsFuel CellsTypes of Fuel CellsAdvantages of Fuel CellsProton Exchange Membrane Fuel CellsMembraneCatalystCatalyst LayerGas Diffusion MediumMicroporous LayerMembrane Electrode AssemblyPlateSingle CellStackSystemCell Voltage Monitoring Module (CVM)Fuel Supply Module (FSM)Air Supply Module (ASM)Exhaust Management Module (EMM)Heat Management Module (HMM)Water Management Module (WMM)Internal Power Supply Module (IPM)Power Conditioning Module (PCM)Communications Module (COM)Controls Module (CM)SummaryThermodynamics and KineticsTheoretical EfficiencyVoltagePo

  4. Nano-Structured Proton Exchange Membrane for Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    Wu Chien-Suen; Lin Fan-Yen; Chu Peter P

    2005-01-01

    @@ 1Introduction Nano-structured materials are characterized by long range ordering of the nano-dimensioned quantum dot units. They have been found to deliver substantially different (electric, optical, magnetic and physical) properties from that of the bulk. The differences are mainly due to the increases of surface charge with large fraction of grain boundaries, and the periodical potential field created by the ordered nano-domains. Specifically,the issues considered in "nano ionics" are the degree of interaction, the charge distribution on the interfaces where they become obvious in ionic properties and thermodynamics such as mobility of charge carriers. Major efforts in this direction are focused on:

  5. POLYMER ELECTROLYTE MEMBRANE FUEL CELLS

    DEFF Research Database (Denmark)

    2001-01-01

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

  6. Structure of porous electrodes in polymer electrolyte membrane fuel cells: An optical reconstruction technique

    Science.gov (United States)

    Berejnov, Viatcheslav; Sinton, David; Djilali, Ned

    Computing flows and phase transport in porous media requires a physically representative geometric model. We present a simple method of digitizing the structure of fibrous porous media commonly used in polymer electrolyte membrane (PEM) fuel cells, the so-called gas diffusion layer (GDL). Employing an inverted microscope and image recognition software we process images of the GDL surface collected manually at different focal lengths with micrometer accuracy. Processing the series of images allows retrieval of local depths of the salient in-focus structural elements in each of the different images. These elements are then recombined into a depth-map representing the three-dimensional structure of the GDL surface. Superimposition of the in-focus portions of the structural elements distributed throughout the stack of images yields digitized data describing the geometry and structural attributes of the 3D surface of the GDL fibrous material.

  7. POLYMER ELECTROLYTE MEMBRANE FUEL CELLS

    DEFF Research Database (Denmark)

    2001-01-01

    A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various...... thermoplastic polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes....... With the thermally resistant polymer, e.g., polybenzimidazole or a mixture of polybenzimidazole and other thermoplastics as binder, the carbon-supported noble metal catalyst is tape-cast onto a hydrophobic supporting substrate. When doped with an acid mixture, electrodes are assembled with an acid doped solid...

  8. Membrane-electrode structures for molecular catalysts for use in fuel cells and other electrochemical devices

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, John B.; Zhu, Xiaobing; Hwang, Gi Suk; Martin, Zulima; He, Qinggang; Driscoll, Peter; Weber, Adam; Clark, Kyle

    2016-09-27

    Water soluble catalysts, (M)meso-tetra(N-Methyl-4-Pyridyl)Porphinepentachloride (M=Fe, Co, Mn & Cu), have been incorporated into the polymer binder of oxygen reduction cathodes in membrane electrode assemblies used in PEM fuel cells and found to support encouragingly high current densities. The voltages achieved are low compared to commercial platinum catalysts but entirely consistent with the behavior observed in electroanalytical measurements of the homogeneous catalysts. A model of the dynamics of the electrode action has been developed and validated and this allows the MEA electrodes to be optimized for any chemistry that has been demonstrated in solution. It has been shown that improvements to the performance will come from modifications to the structure of the catalyst combined with optimization of the electrode structure and a well-founded pathway to practical non-platinum group metal catalysts exists.

  9. 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)

  10. Interfacial Structure, Dynamics, and Transport of Polyelectrolyte Membrane Materials for Fuel Cells

    Science.gov (United States)

    Soles, Christopher; Page, K.; Eastman, S.; Kim, S.; Kang, S.; Dura, J.; National Institute of Standards; Technology; Polymers Divison Team; NIST Collaboration

    2011-03-01

    Polymer electrolyte membranes (PEM) fuel cells show promise for a wide range of applications both in the transportation sector and for stationary power production due to their high charge density and low operating temperatures. While the structure and transport of bulk PEMs have been studied extensively, little is known about these materials at interfaces and under confinement, as they exist within the membrane electrode assembly (MEA). Using neutron/ x-ray reflectivity and polarization-modulation infrared reflection-absorption spectroscopy, we have studied the polymer-substrate interfacial structure, swelling, and water transport as function of humidity, surface chemistry, and film thickness. The interfacial structure is highly dependent upon the substrate surface chemistry and the swelling/water diffusivity are suppressed when the PEM is confined to a thin film. This new information will enable researchers to more accurately model the performance of the MEA as current simulations typically rely on bulk property values to predict water and proton transport under these conditions.

  11. Partially Fluorinated Sulfonated Poly(ether amide Fuel Cell Membranes: Influence of Chemical Structure on Membrane Properties

    Directory of Open Access Journals (Sweden)

    Chulsung Bae

    2011-01-01

    Full Text Available A series of fluorinated sulfonated poly (ether amides (SPAs were synthesized for proton exchange membrane fuel cell applications. A polycondensation reaction of 4,4’-oxydianiline, 2-sulfoterephthalic acid monosodium salt, and tetrafluorophenylene dicarboxylic acids (terephthalic and isophthalic or fluoroaliphatic dicarboxylic acids produced SPAs with sulfonation degrees of 80–90%. Controlling the feed ratio of the sulfonated and unsulfonated dicarboxylic acid monomers afforded random SPAs with ion exchange capacities between 1.7 and 2.2 meq/g and good solubility in polar aprotic solvents. Their structures were characterized using NMR and FT IR spectroscopies. Tough, flexible, and transparent films were obtained with dimethylsulfoxide using a solution casting method. Most SPA membranes with 90% sulfonation degree showed high proton conductivity (>100 mS/cm at 80 °C and 100% relative humidity. Among them, two outstanding ionomers (ODA-STA-TPA-90 and ODA-STA-IPA-90 showed proton conductivity comparable to that of Nafion 117 between 40 and 80 °C. The influence of chemical structure on the membrane properties was systematically investigated by comparing the fluorinated polymers to their hydrogenated counterparts. The results suggest that the incorporation of fluorinated moieties in the polymer backbone of the membrane reduces water absorption. High molecular weight and the resulting physical entanglement of the polymers chains played a more important role in improving stability in water, however.

  12. Electricity producing property and bacterial community structure in microbial fuel cell equipped with membrane electrode assembly.

    Science.gov (United States)

    Rubaba, Owen; Araki, Yoko; Yamamoto, Shuji; Suzuki, Kei; Sakamoto, Hisatoshi; Matsuda, Atsunori; Futamata, Hiroyuki

    2013-07-01

    It is important for practical use of microbial fuel cells (MFCs) to not only develop electrodes and proton exchange membranes but also to understand the bacterial community structure related to electricity generation. Four lactate fed MFCs equipped with different membrane electrode assemblies (MEAs) were constructed with paddy field soil as inoculum. The MEAs significantly affected the electricity-generating properties of the MFCs. MEA-I was made with Nafion 117 solution and the other MEAs were made with different configurations of three kinds of polymers. MFC-I equipped with MEA-I exhibited the highest performance with a stable current density of 55 ± 3 mA m⁻². MFC-III equipped with MEA-III with the highest platinum concentration, exhibited the lowest performance with a stable current density of 1.7 ± 0.1 mA m⁻². SEM observation revealed that there were cracks on MEA-III. These results demonstrated that it is significantly important to prevent oxygen-intrusion for improved MFC performance. By comparing the data of DGGE and phylogenetic analyzes, it was suggested that the dominant bacterial communities of MFC-I were constructed with lactate-fermenters and Fe(III)-reducers, which consisted of bacteria affiliated with the genera of Enterobacter, Dechlorosoma, Pelobacter, Desulfovibrio, Propioniferax, Pelosinus, and Firmicutes. A bacterium sharing 100% similarity to one of the DGGE bands was isolated from MFC-I. The 16S rRNA gene sequence of the isolate shared 98% similarity to gram-positive Propioniferax sp. P7 and it was confirmed that the isolate produced electricity in an MFC. These results suggested that these bacteria are valuable for constructing the electron transfer network in MFC. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  13. Fuel cell and membrane therefore

    Energy Technology Data Exchange (ETDEWEB)

    Aindow, Tai-Tsui

    2016-08-09

    A fuel cell includes first and second flow field plates, and an anode electrode and a cathode electrode between the flow field plates. A polymer electrolyte membrane (PEM) is arranged between the electrodes. At least one of the flow field plates influences, at least in part, an in-plane anisotropic physical condition of the PEM that varies in magnitude between a high value direction and a low value direction. The PEM has an in-plane physical property that varies in magnitude between a high value direction and a low value direction. The PEM is oriented with its high value direction substantially aligned with the high value direction of the flow field plate.

  14. Polymer electrolyte membrane assembly for fuel cells

    Science.gov (United States)

    Yen, Shiao-Ping S. (Inventor); Kindler, Andrew (Inventor); Yavrouian, Andre (Inventor); Halpert, Gerald (Inventor)

    2002-01-01

    An electrolyte membrane for use in a fuel cell can contain sulfonated polyphenylether sulfones. The membrane can contain a first sulfonated polyphenylether sulfone and a second sulfonated polyphenylether sulfone, wherein the first sulfonated polyphenylether and the second sulfonated polyphenylether sulfone have equivalent weights greater than about 560, and the first sulfonated polyphenylether and the second sulfonated polyphenylether sulfone also have different equivalent weights. Also, a membrane for use in a fuel cell can contain a sulfonated polyphenylether sulfone and an unsulfonated polyphenylether sulfone. Methods for manufacturing a membrane electrode assemblies for use in fuel cells can include roughening a membrane surface. Electrodes and methods for fabricating such electrodes for use in a chemical fuel cell can include sintering an electrode. Such membranes and electrodes can be assembled into chemical fuel cells.

  15. In-membrane micro fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Omosebi, Ayokunle; Besser, Ronald

    2016-09-06

    An in-membrane micro fuel cell comprises an electrically-insulating membrane that is permissive to the flow of cations, such as protons, and a pair of electrodes deposited on channels formed in the membrane. The channels are arranged as conduits for fluids, and define a membrane ridge between the channels. The electrodes are porous and include catalysts for promoting the liberation of a proton and an electron from a chemical species and/or or the recombination of a proton and an electron with a chemical specie. The fuel cell may be provided a biosensor, an electrochemical sensor, a microfluidic device, or other microscale devices fabricated in the fuel cell membrane.

  16. 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.

  17. Advanced composite polymer electrolyte fuel cell membranes

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.S.; Zawodzinski, T.A.; Gottesfeld, S.; Kolde, J.A.; Bahar, B.

    1995-09-01

    A new type of reinforced composite perfluorinated polymer electrolyte membrane, GORE-SELECT{trademark} (W.L. Gore & Assoc.), is characterized and tested for fuel cell applications. Very thin membranes (5-20 {mu}m thick) are available. The combination of reinforcement and thinness provides high membrane, conductances (80 S/cm{sup 2} for a 12 {mu}m thick membrane at 25{degrees}C) and improved water distribution in the operating fuel cell without sacrificing longevity or durability. In contrast to nonreinforced perfluorinated membranes, the x-y dimensions of the GORE-SELECT membranes are relatively unaffected by the hydration state. This feature may be important from the viewpoints of membrane/electrode interface stability and fuel cell manufacturability.

  18. Alternate Fuel Cell Membranes for Energy Independence

    Energy Technology Data Exchange (ETDEWEB)

    Storey, Robson, F.; Mauritz, Kenneth, A.; Patton, Derek, L.; Savin, Daniel, A.

    2012-12-18

    performance properties of experimental membranes, 9) fabrication and FC performance testing of membrane electrode assemblies (MEA) from experimental membranes, and 10) measurement of ex situ and in situ membrane durability of experimental membranes. Although none of the experimental hydrocarbon membranes that issued from the project displayed proton conductivities that met DOE requirements, the project contributed to our basic understanding of membrane structure-property relationships in a number of key respects. An important finding of the benchmark studies is that physical degradation associated with humidity and temperature variations in the FC tend to open new fuel crossover pathways and act synergistically with chemical degradation to accelerate overall membrane degradation. Thus, for long term membrane survival and efficient fuel utilization, membranes must withstand internal stresses due to humidity and temperature changes. In this respect, rigid aromatic hydrocarbon fuel cell membranes, e.g. PAES, offer an advantage over un-modified Nafion membranes. The benchmark studies also showed that broadband dielectric spectroscopy is a potentially powerful tool in assessing shifts in the fundamental macromolecular dynamics caused by Nafion chemical degradation, and thus, this technique is of relevance in interrogating proton exchange membrane durability in fuel cells and macromolecular dynamics as coupled to proton migration, which is of fundamental relevance in proton exchange membranes in fuel cells. A key finding from the hydrocarbon membrane synthesis effort was that rigid aromatic polymers containing isolated ion exchange groups tethered tightly to the backbone (short tether), such as HPPS, provide excellent mechanical and durability properties but do not provide sufficient conductivity, in either random or block configuration, when used as the sole ion exchange monomer. However, we continue to hypothesize that longer tethers, and tethered groups spaced more closely

  19. Proton exchange membrane fuel cells modeling

    CERN Document Server

    Gao, Fengge; Miraoui, Abdellatif

    2013-01-01

    The fuel cell is a potential candidate for energy storage and conversion in our future energy mix. It is able to directly convert the chemical energy stored in fuel (e.g. hydrogen) into electricity, without undergoing different intermediary conversion steps. In the field of mobile and stationary applications, it is considered to be one of the future energy solutions.Among the different fuel cell types, the proton exchange membrane (PEM) fuel cell has shown great potential in mobile applications, due to its low operating temperature, solid-state electrolyte and compactness.This book pre

  20. Analysis of the control structures for an integrated ethanol processor for proton exchange membrane fuel cell systems

    Science.gov (United States)

    Biset, S.; Nieto Deglioumini, L.; Basualdo, M.; Garcia, V. M.; Serra, M.

    The aim of this work is to investigate which would be a good preliminary plantwide control structure for the process of Hydrogen production from bioethanol to be used in a proton exchange membrane (PEM) accounting only steady-state information. The objective is to keep the process under optimal operation point, that is doing energy integration to achieve the maximum efficiency. Ethanol, produced from renewable feedstocks, feeds a fuel processor investigated for steam reforming, followed by high- and low-temperature shift reactors and preferential oxidation, which are coupled to a polymeric fuel cell. Applying steady-state simulation techniques and using thermodynamic models the performance of the complete system with two different control structures have been evaluated for the most typical perturbations. A sensitivity analysis for the key process variables together with the rigorous operability requirements for the fuel cell are taking into account for defining acceptable plantwide control structure. This is the first work showing an alternative control structure applied to this kind of process.

  1. Analysis of the control structures for an integrated ethanol processor for proton exchange membrane fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Biset, S.; Nieto Deglioumini, L.; Basualdo, M. [GIAIP-CIFASIS (UTN-FRRo-CONICET-UPCAM-UNR), BV. 27 de Febrero 210 Bis, S2000EZP Rosario (Argentina); Garcia, V.M.; Serra, M. [Institut de Robotica i Informatica Industrial, C. Llorens i Artigas 4-6, 08028 Barcelona (Spain)

    2009-07-01

    The aim of this work is to investigate which would be a good preliminary plantwide control structure for the process of Hydrogen production from bioethanol to be used in a proton exchange membrane (PEM) accounting only steady-state information. The objective is to keep the process under optimal operation point, that is doing energy integration to achieve the maximum efficiency. Ethanol, produced from renewable feedstocks, feeds a fuel processor investigated for steam reforming, followed by high- and low-temperature shift reactors and preferential oxidation, which are coupled to a polymeric fuel cell. Applying steady-state simulation techniques and using thermodynamic models the performance of the complete system with two different control structures have been evaluated for the most typical perturbations. A sensitivity analysis for the key process variables together with the rigorous operability requirements for the fuel cell are taking into account for defining acceptable plantwide control structure. This is the first work showing an alternative control structure applied to this kind of process. (author)

  2. Novel proton exchange membrane fuel cell electrodes to improve performance of reversible fuel cell systems

    Science.gov (United States)

    Brown, Tim Matthew

    Proton exchange membrane (PEM) fuel cells react fuel and oxidant to directly and efficiently produce electrical power, without the need for combustion, heat engines, or motor-generators. Additionally, PEM fuel cell systems emit zero to virtually zero criteria pollutants and have the ability to reduce CO2 emissions due to their efficient operation, including the production or processing of fuel. A reversible fuel cell (RFC) is one particular application for a PEM fuel cell. In this application the fuel cell is coupled with an electrolyzer and a hydrogen storage tank to complete a system that can store and release electrical energy. These devices can be highly tailored to specific energy storage applications, potentially surpassing the performance of current and future secondary battery technology. Like all PEM applications, RFCs currently suffer from performance and cost limitations. One approach to address these limitations is to improve the cathode performance by engineering more optimal catalyst layer geometry as compared to the microscopically random structure traditionally used. Ideal configurations are examined and computer modeling shows promising performance improvements are possible. Several novel manufacturing methods are used to build and test small PEM fuel cells with novel electrodes. Additionally, a complete, dynamic model of an RFC system is constructed and the performance is simulated using both traditional and novel cathode structures. This work concludes that PEM fuel cell microstructures can be tailored to optimize performance based on design operating conditions. Computer modeling results indicate that novel electrode microstructures can improve fuel cell performance, while experimental results show similar performance gains that bolster the theoretical predictions. A dynamic system model predicts that novel PEM fuel cell electrode structures may enable RFC systems to be more competitive with traditional energy storage technology options.

  3. Dendronized Polymer Architectures for Fuel Cell Membranes

    DEFF Research Database (Denmark)

    Nielsen, Mads Møller; Dimitrov, Ivaylo; Takamuku, S.

    2013-01-01

    Multi‐step synthetic pathways to low‐ion exchange capacity (IEC) polysulfone (PSU) with sulfonic acid functionalized aliphatic dendrons and sulfonated comb‐type PSU structures are developed and investigated in a comparative study as non‐fluorinated proton exchange membrane (PEM) candidates. In each...... case the side chains are synthesized and introduced in their sulfonated form onto an azide‐functionalized PSU via click chemistry. Three degrees of substitution of each architecture were prepared in order to evaluate the dependence on number of sulfonated side chains. Solution cast membranes were...... evaluated as PEMs for use in fuel cells by proton conductivity measurements, and in the case of dendronized architectures: thermal stability. The proposed synthetic strategy facilitates exploration of a non‐fluorous system with various flexible side chains where IEC is tunable by the degree of substitution....

  4. Polymer Materials for Fuel Cell Membranes :Sulfonated Poly(ether sulfone) for Universal Fuel Cell Operations

    Institute of Scientific and Technical Information of China (English)

    Hyoung-Juhn Kim

    2005-01-01

    @@ 1Introduction Polymer electrolyte fuel cells (PEFCs) have been spotlighted because they are clean and highly efficient power generation system. Proton exchange membrane fuel cells (PEMFCs), which use reformate gases or pure H2 for a fuel, have been employed for automotives and residential usages. Also, liquid-feed fuel cells such as direct methanol fuel cell (DMFC) and direct formic acid fuel cell (DFAFC) were studied for portable power generation.

  5. Biological Fuel Cells and Membranes.

    Science.gov (United States)

    Ghassemi, Zahra; Slaughter, Gymama

    2017-01-17

    Biofuel cells have been widely used to generate bioelectricity. Early biofuel cells employ a semi-permeable membrane to separate the anodic and cathodic compartments. The impact of different membrane materials and compositions has also been explored. Some membrane materials are employed strictly as membrane separators, while some have gained significant attention in the immobilization of enzymes or microorganisms within or behind the membrane at the electrode surface. The membrane material affects the transfer rate of the chemical species (e.g., fuel, oxygen molecules, and products) involved in the chemical reaction, which in turn has an impact on the performance of the biofuel cell. For enzymatic biofuel cells, Nafion, modified Nafion, and chitosan membranes have been used widely and continue to hold great promise in the long-term stability of enzymes and microorganisms encapsulated within them. This article provides a review of the most widely used membrane materials in the development of enzymatic and microbial biofuel cells.

  6. Membrane electrode assembly for a fuel cell

    Science.gov (United States)

    Prakash, Surya (Inventor); Narayanan, Sekharipuram R. (Inventor); Atti, Anthony (Inventor); Olah, George (Inventor); Smart, Marshall C. (Inventor)

    2006-01-01

    A catalyst ink for a fuel cell including a catalytic material and poly(vinylidene fluoride). The ink may be applied to a substrate to form an electrode, or bonded with other electrode layers to form a membrane electrode assembly (MEA).

  7. High temperature polymer electrolyte membrane fuel cell

    Institute of Scientific and Technical Information of China (English)

    K.Scott; M. Mamlouk

    2006-01-01

    One of the major issues limiting the introduction of polymer electrolyte membrane fuel cells (PEMFCs) is the low temperature of operation which makes platinum-based anode catalysts susceptible to poisoning by the trace amount of CO, inevitably present in reformed fuel. In order to alleviate the problem of CO poisoning and improve the power density of the cell, operating at temperature above 100 ℃ is preferred. Nafion(R) -type perfluorosulfonated polymers have been typically used for PEMFC. However, the conductivity of Nafion(R) -type polymers is not high enough to be used for fuel cell operations at higher temperature ( > 90 ℃) and atmospheric pressure because they dehydrate under these condition.An additional problem which faces the introduction of PEMFC technology is that of supplying or storing hydrogen for cell operation,especially for vehicular applications. Consequently the use of alternative fuels such as methanol and ethanol is of interest, especially if this can be used directly in the fuel cell, without reformation to hydrogen. A limitation of the direct use of alcohol is the lower activity of oxidation in comparison to hydrogen, which means that power densities are considerably lower. Hence to improve activity and power output higher temperatures of operation are preferable. To achieve this goal, requires a new polymer electrolyte membrane which exhibits stability and high conductivity in the absence of liquid water.Experimental data on a polybenzimidazole based PEMFC were presented. A simple steady-state isothermal model of the fuel cell is also used to aid in fuel cell performance optimisation. The governing equations involve the coupling of kinetic, ohmic and mass transport. This paper also considers the advances made in the performance of direct methanol and solid polymer electrolyte fuel cells and considers their limitations in relation to the source and type of fuels to be used.

  8. High temperature polymer electrolyte membrane fuel cells

    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 the book describe rationalization and illustration of approaches to high temperature PEM systems. Chapters 6 - 13 are devoted to fabrication, optimization and characterization of phosphoric acid-doped polybenzimidazole membranes, the very first electrolyte system that has demonstrated the concept...... 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....

  9. Scanning transmission X-ray microscopy of nano structured thin film catalysts for proton-exchange-membrane fuel cells

    Science.gov (United States)

    Lee, Vincent; Berejnov, Viatcheslav; West, Marcia; Kundu, Sumit; Susac, Darija; Stumper, Jürgen; Atanasoski, Radoslav T.; Debe, Mark; Hitchcock, Adam P.

    2014-10-01

    Scanning transmission X-ray microscopy (STXM) has been applied to characterize nano structured thin film (NSTF) catalysts implemented as electrode materials in proton-exchange-membrane (PEM) fuel cells. STXM is used to study all chemical constituents at various stages in the fabrication process, from the perylene red (PR149) starting material, through the formation of the uncoated perylene whiskers, their coated form with Pt-based catalyst, and toward the NSTF anode fully integrated into the catalyst coated membrane (CCM). CCM samples were examined prior to operational testing and after several different accelerated testing protocols: start-up/shut-down (SU/SD), and reversal tests. It was found that, while the perylene support material is present in the pre-test samples, it was completely absent in the post-test samples. We attribute this loss of perylene material to the presence of cracks in the catalyst combined with intensive hydrogenation processes happening at the anode during operation. Despite the loss of the perylene support, the platinum shells forming the NSTF anode catalyst layer performed well during the tests.

  10. Sterion membranes in Direct Methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Linares, J. J.; Lobato, J.; Canizares, P.; Rodrigo, M. A.; Fernandez, A.

    2005-07-01

    Direct Methanol Fuel Cells (DMFCs) has been postulated as an alternative to traditional hydrogen fed Polymer Electrolyte Membrane Fuel Cells (H2-PEMFCs). Among their advantages, it can be pointed out the low cost of the fuel, simplicity of design, large availability, easy handling and distribution. However, there are still some challenges in this field, such as the development of electrocatalysts which can enhance the electrokinetics of methanol oxidation, the discovery of an electrolyte membrane with high conductivity and low methanol crossover at the same time and the production of methanol-tolerant electrocatalysts with high activity for oxygen reduction. So far, Nafion 117 has been the polymer membrane most widely used in DMFCs. Yet, it is well known that Nafion (Du Pont Inc.) membranes are not good barrier for methanol, so that the coulombic efficiency of Nafion-based DMFCs is significantly reduced by the chemical oxidation of methanol in the cathode. Recently, a new perfluorinated polymer with sulphonic acid groups (PFSA) has been developed, under the commercial name of Sterion (David Fuel Cell Components). As a difference as opposed to Nafion, this membrane is cast by the solution casting method, which provides a different sulphonic cluster configuration as compared to the extrusion cast Nafion membranes, which may give rise to different methanol crossover behaviour. In this work, it has been studied and analysed the suitability of Sterion in the DMFCs field. For that, it has been measured the methanol permeability of this membrane at different solute concentration and temperature, and its performance in an actual fuel cell at different operational conditions, such as methanol concentration, temperature and back pressure. Tests have been made using both oxygen and air in the cathode and half-cell potentials have been evaluated in some measurements in order to discriminate the contribution of both semi-reactions to the overall cell overvoltage. A lifetime

  11. Fuel cell membranes and crossover prevention

    Science.gov (United States)

    Masel, Richard I.; York, Cynthia A.; Waszczuk, Piotr; Wieckowski, Andrzej

    2009-08-04

    A membrane electrode assembly for use with a direct organic fuel cell containing a formic acid fuel includes a solid polymer electrolyte having first and second surfaces, an anode on the first surface and a cathode on the second surface and electrically linked to the anode. The solid polymer electrolyte has a thickness t:.gtoreq..times..times..times..times. ##EQU00001## where C.sub.f is the formic acid fuel concentration over the anode, D.sub.f is the effective diffusivity of the fuel in the solid polymer electrolyte, K.sub.f is the equilibrium constant for partition coefficient for the fuel into the solid polymer electrolyte membrane, I is Faraday's constant n.sub.f is the number of electrons released when 1 molecule of the fuel is oxidized, and j.sub.f.sup.c is an empirically determined crossover rate of fuel above which the fuel cell does not operate.

  12. Improved Membrane Materials for PEM Fuel Cell Application

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth A. Mauritz; Robert B. Moore

    2008-06-30

    The overall goal of this project is to collect and integrate critical structure/property information in order to develop methods that lead to significant improvements in the durability and performance of polymer electrolyte membrane fuel cell (PEMFC) materials. This project is focused on the fundamental improvement of PEMFC membrane materials with respect to chemical, mechanical and morphological durability as well as the development of new inorganically-modified membranes.

  13. Polyarylenethioethersulfone Membranes for Fuel Cells (Postprint)

    Science.gov (United States)

    2010-01-01

    release; distribution unlimited. See additional restrictions described on inside pages STINFO COPY © 2007 The Electrochemical Society AIR...PAO Case Number: 88ABW-2007-1713; Clearance Date: 24 July 2007. © 2007 The Electrochemical Society . The U.S. Government is joint author of the work...it to be a potential candidate for membranes in fuel cells. © 2007 The Electrochemical Society . DOI: 10.1149/1.2755881 All rights reserved

  14. Effects of polymer structure on properties of sulfonated polyimide/protic ionic liquid composite membranes for nonhumidified fuel cell applications.

    Science.gov (United States)

    Yasuda, Tomohiro; Nakamura, Shin-ichiro; Honda, Yoshiyuki; Kinugawa, Kei; Lee, Seung-Yul; Watanabe, Masayoshi

    2012-03-01

    To investigate the effects of polymer structure on the properties of composite membranes including a protic ionic liquid, [dema][TfO] (diethylmethylammonium trifluoromethanesulfonate), for nonhumidified fuel cell applications, we synthesized sulfonated polyimides (SPIs) with different structures as matrix polymers, which have different magnitudes of ion-exchange capacities (IECs), different sequence distributions of ionic groups, and positions of sulfonate groups in the main chain or side chain. Despite having similar IECs, multiblock copolymer SPI and random copolymer SPI having sulfonate groups in the side chain exhibit higher ionic conductivity than random copolymer SPI having sulfonate groups in the main chain, indicating that the flexibility of sulfonic acid groups and the sequence distribution of ionic groups greatly affect the ion conduction. Atomic force microscopy observation revealed that the multiblock copolymer SPI forms more developed phase separation than the others. These results indicate that the flexibility of sulfonic acid groups and the connectivity of the ion conduction channel, which greatly depends on the sequence distribution, affect the ion conduction.

  15. 3D visualization of membrane failures in fuel cells

    Science.gov (United States)

    Singh, Yadvinder; Orfino, Francesco P.; Dutta, Monica; Kjeang, Erik

    2017-03-01

    Durability issues in fuel cells, due to chemical and mechanical degradation, are potential impediments in their commercialization. Hydrogen leak development across degraded fuel cell membranes is deemed a lifetime-limiting failure mode and potential safety issue that requires thorough characterization for devising effective mitigation strategies. The scope and depth of failure analysis has, however, been limited by the 2D nature of conventional imaging. In the present work, X-ray computed tomography is introduced as a novel, non-destructive technique for 3D failure analysis. Its capability to acquire true 3D images of membrane damage is demonstrated for the very first time. This approach has enabled unique and in-depth analysis resulting in novel findings regarding the membrane degradation mechanism; these are: significant, exclusive membrane fracture development independent of catalyst layers, localized thinning at crack sites, and demonstration of the critical impact of cracks on fuel cell durability. Evidence of crack initiation within the membrane is demonstrated, and a possible new failure mode different from typical mechanical crack development is identified. X-ray computed tomography is hereby established as a breakthrough approach for comprehensive 3D characterization and reliable failure analysis of fuel cell membranes, and could readily be extended to electrolyzers and flow batteries having similar structure.

  16. Advanced membrane electrode assemblies for fuel cells

    Science.gov (United States)

    Kim, Yu Seung; Pivovar, Bryan S

    2014-02-25

    A method of preparing advanced membrane electrode assemblies (MEA) for use in fuel cells. A base polymer is selected for a base membrane. An electrode composition is selected to optimize properties exhibited by the membrane electrode assembly based on the selection of the base polymer. A property-tuning coating layer composition is selected based on compatibility with the base polymer and the electrode composition. A solvent is selected based on the interaction of the solvent with the base polymer and the property-tuning coating layer composition. The MEA is assembled by preparing the base membrane and then applying the property-tuning coating layer to form a composite membrane. Finally, a catalyst is applied to the composite membrane.

  17. Polymers application in proton exchange membranes for fuel cells (PEMFCs)

    Science.gov (United States)

    Walkowiak-Kulikowska, Justyna; Wolska, Joanna; Koroniak, Henryk

    2017-07-01

    This review presents the most important research on alternative polymer membranes with ionic groups attached, provides examples of materials with a well-defined chemical structure that are described in the literature. Furthermore, it elaborates on the synthetic methods used for preparing PEMs, the current status of fuel cell technology and its application. It also briefly discusses the development of the PEMFC market.

  18. Electrically Conductive, Hydrophilic Porous Membrane for Fuel Cell Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I effort seeks to produce a conductive polyethersulfone (PES) microporous membrane for fuel cell water management applications. This membrane will...

  19. Selectivity of Direct Methanol Fuel Cell Membranes

    Directory of Open Access Journals (Sweden)

    Antonino S. Aricò

    2015-11-01

    Full Text Available Sulfonic acid-functionalized polymer electrolyte membranes alternative to Nafion® were developed. These were hydrocarbon systems, such as blend sulfonated polyetheretherketone (s-PEEK, new generation perfluorosulfonic acid (PFSA systems, and composite zirconium phosphate–PFSA polymers. The membranes varied in terms of composition, equivalent weight, thickness, and filler and were investigated with regard to their methanol permeation characteristics and proton conductivity for application in direct methanol fuel cells. The behavior of the membrane electrode assemblies (MEA was investigated in fuel cell with the aim to individuate a correlation between membrane characteristics and their performance in a direct methanol fuel cell (DMFC. The power density of the DMFC at 60 °C increased according to a square root-like function of the membrane selectivity. This was defined as the reciprocal of the product between area specific resistance and crossover. The power density achieved at 60 °C for the most promising s-PEEK-based membrane-electrode assembly (MEA was higher than the benchmark Nafion® 115-based MEA (77 mW·cm−2 vs. 64 mW·cm−2. This result was due to a lower methanol crossover (47 mA·cm−2 equivalent current density for s-PEEK vs. 120 mA·cm−2 for Nafion® 115 at 60 °C as recorded at OCV with 2 M methanol and a suitable area specific resistance (0.15 Ohm cm2 for s-PEEK vs. 0.22 Ohm cm2 for Nafion® 115.

  20. Selectivity of Direct Methanol Fuel Cell Membranes

    Science.gov (United States)

    Aricò, Antonino S.; Sebastian, David; Schuster, Michael; Bauer, Bernd; D’Urso, Claudia; Lufrano, Francesco; Baglio, Vincenzo

    2015-01-01

    Sulfonic acid-functionalized polymer electrolyte membranes alternative to Nafion® were developed. These were hydrocarbon systems, such as blend sulfonated polyetheretherketone (s-PEEK), new generation perfluorosulfonic acid (PFSA) systems, and composite zirconium phosphate–PFSA polymers. The membranes varied in terms of composition, equivalent weight, thickness, and filler and were investigated with regard to their methanol permeation characteristics and proton conductivity for application in direct methanol fuel cells. The behavior of the membrane electrode assemblies (MEA) was investigated in fuel cell with the aim to individuate a correlation between membrane characteristics and their performance in a direct methanol fuel cell (DMFC). The power density of the DMFC at 60 °C increased according to a square root-like function of the membrane selectivity. This was defined as the reciprocal of the product between area specific resistance and crossover. The power density achieved at 60 °C for the most promising s-PEEK-based membrane-electrode assembly (MEA) was higher than the benchmark Nafion® 115-based MEA (77 mW·cm−2 vs. 64 mW·cm−2). This result was due to a lower methanol crossover (47 mA·cm−2 equivalent current density for s-PEEK vs. 120 mA·cm−2 for Nafion® 115 at 60 °C as recorded at OCV with 2 M methanol) and a suitable area specific resistance (0.15 Ohm cm2 for s-PEEK vs. 0.22 Ohm cm2 for Nafion® 115). PMID:26610582

  1. 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.

  2. Low cost, high temperature membranes for PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-08-15

    This report details the results of a project to develop novel, low-cost high temperature membranes specifically for automotive fuel cell use. The specific aim of the project was to determine whether a polyaromatic hydrocarbon membrane could be developed that would give a performance (0.68V at 500 mAcm{sub -2}) competitive with an established perfluoronated sulfonic acid (PSA) membrane in a fuel cell at 120{sup o}C and relative humidity of less than 50%. The novel approach used in this project was to increase the concentration of sulphonic groups to a useful level without dissolution by controlling the molecular structure of the membrane through the design of the monomer repeat unit. The physicochemical properties of 70 polymers synthesised in order to determine the effects of controlled sequence distribution were identified using an array of analytical techniques. Appropriate membranes were selected for fuel cell testing and fabricated into membrane electrode assemblies. Most of the homopolymers tested were able to withstand low humidity environments without immediate catastrophic failure and some showed promise from accelerated durability results. The properties of a simple starting polymer structure were found to be enhanced by doping with sulphonated copper phthalocyanine, resulting in high temperature capacity from a potential cheap, simple and scaleable process. The accelerated and long-term durability of such a doped polymer membrane showed that polyaromatics could easily outperform fluoropolymers under high temperature (120{sup o}C) operating conditions.

  3. Alternative membranes for polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, A.K.; Pitchumani, S.; Sridhar, P.; Shukla, A.K. [Central Electrochemical Research Inst., Karaikudi (India)

    2009-07-01

    Nafion, a perfluoro-sulfonated membrane, is utilized as a membrane electrolyte in polymer electrolyte fuel cells (PEFCs). However, to realize optimum PEFC performance, the Nafion membrane needs to be fully humidified, making the system quite costly. Therefore, in order to solve this problem, alternative membrane electrolytes that could operate under low humidity conditions are needed. This paper reported on composite Nafion membranes with ceramic/inorganic fillers such as silica and mesoporous zirconium phosphate (MZP). Silica was impregnated to the Nafion matrix by a unique water hydrolysis sol-gel route and casted as a composite membrane while MZP, a solid-super-acid-proton-conducting medium as well as water absorbing material was synthesized by a co-assembly technique and impregnated to the Nafion matrix to form a composite membrane. The performance of the PEFCs with Nafion membrane and composite membranes was tested with hydrogen/oxygen gas and hydrogen/air feeds at varying relative humidity (RH) values under ambient conditions. It was concluded that under RH value as low as 18 per cent, the PEFC with Nafion membrane delivers a peak-power density of only 130 mW/square centimeter.

  4. Microstructured Electrolyte Membranes to Improve Fuel Cell Performance

    Science.gov (United States)

    Wei, Xue

    Fuel cells, with the advantages of high efficiency, low greenhouse gas emission, and long lifetime are a promising technology for both portable power and stationary power sources. The development of efficient electrolyte membranes with high ionic conductivity, good mechanical durability and dense structure at low cost remains a challenge to the commercialization of fuel cells. This thesis focuses on exploring novel composite polymer membranes and ceramic electrolytes with the microstructure engineered to improve performance in direct methanol fuel cells (DMFCs) and solid oxide fuel cells (SOFCs), respectively. Polymer/particle composite membranes hold promise to meet the demands of DMFCs at lower cost. The structure of composite membranes was controlled by aligning proton conducting particles across the membrane thickness under an applied electric field. The field-induced structural changes caused the membranes to display an enhanced water uptake, proton conductivity, and methanol permeability in comparison to membranes prepared without an applied field. Although both methanol permeability and proton conductivity are enhanced by the applied field, the permeability increase is relatively lower than the proton conductivity improvement, which results in enhanced proton/methanol selectivity and improved DMFC performance. Apatite ceramics are a new class of fast ion conductors being studied as alternative SOFC electrolytes in the intermediate temperature range. An electrochemical/hydrothermal deposition method was developed to grow fully dense apatite membranes containing well-developed crystals with c-axis alignment to promote ion conductivity. Hydroxyapatite seed crystals were first deposited onto a metal substrate electrochemically. Subsequent ion substitution during the hydrothermal growth process promoted the formation of dense, fully crystalline films with microstructure optimal for ion transport. The deposition parameters were systematically investigated, such as

  5. Blend Concepts for Fuel Cell Membranes

    Institute of Scientific and Technical Information of China (English)

    J. Kerres

    2005-01-01

    @@ 1Introduction Direct methanol fuel cells (DMFC) are an alternative to lithium ion batteries as energy supply for mobile applications such as laptops, PDA's and cellphones. It would be advantageous if pure or highly concentrated methanol could be used as the fuel in these DMFC, due to the high energy density of meOH. However, most of the ionomer membranes used up to now as proton conductor in DMFC can not withstand pure or highly concentrated methanol due to extreme swelling or even dissolution under these conditions. Therefore it is required to prepare H+ -conducting membranes which remain dimensionally stable in pure or highly concentrated methanol. One way to approach this goal is to cross-link the ionomer membranes so that the swelling under the desired methanol-rich conditions is limited.

  6. Alkaline fuel cell with nitride membrane

    Science.gov (United States)

    Sun, Shen-Huei; Pilaski, Moritz; Wartmann, Jens; Letzkus, Florian; Funke, Benedikt; Dura, Georg; Heinzel, Angelika

    2017-06-01

    The aim of this work is to fabricate patterned nitride membranes with Si-MEMS-technology as a platform to build up new membrane-electrode-assemblies (MEA) for alkaline fuel cell applications. Two 6-inch wafer processes based on chemical vapor deposition (CVD) were developed for the fabrication of separated nitride membranes with a nitride thickness up to 1 μm. The mechanical stability of the perforated nitride membrane has been adjusted in both processes either by embedding of subsequent ion implantation step or by optimizing the deposition process parameters. A nearly 100% yield of separated membranes of each deposition process was achieved with layer thickness from 150 nm to 1 μm and micro-channel pattern width of 1μm at a pitch of 3 μm. The process for membrane coating with electrolyte materials could be verified to build up MEA. Uniform membrane coating with channel filling was achieved after the optimization of speed controlled dip-coating method and the selection of dimethylsulfoxide (DMSO) as electrolyte solvent. Finally, silver as conductive material was defined for printing a conductive layer onto the MEA by Ink-Technology. With the established IR-thermography setup, characterizations of MEAs in terms of catalytic conversion were performed successfully. The results of this work show promise for build up a platform on wafer-level for high throughput experiments.

  7. Durability of symmetrically and asymmetrically porous polybenzimidazole membranes for high temperature proton exchange membrane fuel cells

    Science.gov (United States)

    Jheng, Li-Cheng; Chang, Wesley Jen-Yang; Hsu, Steve Lien-Chung; Cheng, Po-Yang

    2016-08-01

    Two types of porous polybenzimidazole (PBI) membranes with symmetric and asymmetric morphologies were fabricated by the template-leaching method and characterized by scanning electron microscope (SEM). Their physicochemical properties were compared in terms of acid-doping level, proton conductivity, mechanical strength, and oxidative stability. The durability of fuel cell operation is one of the most challenging for the PBI based membrane electrode assembly (MEA) used in high-temperature proton exchange membrane fuel cells (HT-PEMFCs). In the present work, we carried out a long-term steady-state fuel cell test to compare the effect of membrane structure on the cell voltage degradation. It has also been demonstrated that the asymmetrically porous PBI could bring some notable improvements on the durability of fuel cell operation, the fuel crossover problem, and the phosphoric acid leakage.

  8. 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

    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...... 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...

  9. The Structure and Properties of Pulsed dc Sputtered Nanocrystalline NbN Coatings for Proton Exchange Membrane Fuel Cell.

    Science.gov (United States)

    Chun, Sung-Yong

    2016-02-01

    Niobium nitride coatings for the surface modified proton exchange membrane fuel cells with various pulse parameters have been prepared using dc (direct current) and asymmetric-bipolar pulsed dc magnetron sputtering. The pulse frequency and the duty cycle were varied from 5 to 50 kHz and 50 to 95%, respectively. The deposition rate, grain size and resistivity of pulsed dc sputtered films were decreased when the pulse frequency increased, while the nano hardness of niobium nitride films increased. We present in detail coatings (e.g., deposition rate, grain size, prefer-orientation, resistivity and hardness). Our studies show that niobium nitride coatings with superior properties can be prepared using asymmetric-bipolar pulsed dc sputtering.

  10. Analysis of Water Management in Proton Exchange Membrane Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A two-dimensional, steady-state, isothermal water-management model for a complete proton exchange membrane fuel cell (PEMFC) was developed. The model includes the transport in the diffusion layer and the proton exchange membrane (PEM) with a pseudo-homogeneous model for the cathode catalyst layer. The predicted fuel cell performance with variable cathode porosities compares well with experimental results. The model is then used to investigate the effects of some structural parameters, such as the rib size, the interdigitated flow field, and various operating conditions including the gas flow rate, the cell temperature and pressure, humidification, and the relative humidity at the inlet. Water management is best achieved by tuning the anode operating conditions.

  11. Water Soluble Polymers as Proton Exchange Membranes for Fuel Cells

    Directory of Open Access Journals (Sweden)

    Bing-Joe Hwang

    2012-03-01

    Full Text Available The relentless increase in the demand for useable power from energy-hungry economies continues to drive energy-material related research. Fuel cells, as a future potential power source that provide clean-at-the-point-of-use power offer many advantages such as high efficiency, high energy density, quiet operation, and environmental friendliness. Critical to the operation of the fuel cell is the proton exchange membrane (polymer electrolyte membrane responsible for internal proton transport from the anode to the cathode. PEMs have the following requirements: high protonic conductivity, low electronic conductivity, impermeability to fuel gas or liquid, good mechanical toughness in both the dry and hydrated states, and high oxidative and hydrolytic stability in the actual fuel cell environment. Water soluble polymers represent an immensely diverse class of polymers. In this comprehensive review the initial focus is on those members of this group that have attracted publication interest, principally: chitosan, poly (ethylene glycol, poly (vinyl alcohol, poly (vinylpyrrolidone, poly (2-acrylamido-2-methyl-1-propanesulfonic acid and poly (styrene sulfonic acid. The paper then considers in detail the relationship of structure to functionality in the context of polymer blends and polymer based networks together with the effects of membrane crosslinking on IPN and semi IPN architectures. This is followed by a review of pore-filling and other impregnation approaches. Throughout the paper detailed numerical results are given for comparison to today’s state-of-the-art Nafion® based materials.

  12. Proton Exchange Membrane Fuel Cells Applied for Transport Sector

    DEFF Research Database (Denmark)

    Hosseinzadeh, Elham; Rokni, Masoud

    2010-01-01

    A thermodynamic analysis of a PEMFC (proton exchange membrane fuel cell) is investigated. PEMFC may be the most promising technology for fuel cell automotive systems, which is operating at quite low temperatures, (between 60 to 80℃). In this study the fuel cell motive power part of a lift truck has...... investigated. In addition, different stack design schemes have been proposed and their effect on system efficiency has been investigated....

  13. Conductivity Measurements of Synthesized Heteropoly Acid Membranes for Proton Exchange Membrane Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Record, K.A.; Haley, B.T.; Turner, J.

    2006-01-01

    Fuel cell technology is receiving attention due to its potential to be a pollution free method of electricity production when using renewably produced hydrogen as fuel. In a Proton Exchange Membrane (PEM) fuel cell H2 and O2 react at separate electrodes, producing electricity, thermal energy, and water. A key component of the PEM fuel cell is the membrane that separates the electrodes. DuPont’s Nafion® is the most commonly used membrane in PEM fuel cells; however, fuel cell dehydration at temperatures near 100°C, resulting in poor conductivity, is a major hindrance to fuel cell performance. Recent studies incorporating heteropoly acids (HPAs) into membranes have shown an increase in conductivity and thus improvement in performance. HPAs are inorganic materials with known high proton conductivities. The primary objective of this work is to measure the conductivity of Nafion, X-Ionomer membranes, and National Renewable Energy Laboratory (NREL) Developed Membranes that are doped with different HPAs at different concentrations. Four-point conductivity measurements using a third generation BekkTech conductivity test cell are used to determine membrane conductivity. The effect of multiple temperature and humidification levels is also examined. While the classic commercial membrane, Nafion, has a conductivity of approximately 0.10 S/cm, measurements for membranes in this study range from 0.0030 – 0.58 S/cm, depending on membrane type, structure of the HPA, and the relative humidity. In general, the X-ionomer with H6P2W21O71 HPA gave the highest conductivity and the Nafion with the 12-phosphotungstic (PW12) HPA gave the lowest. The NREL composite membranes had conductivities on the order of 0.0013 – 0.025 S/cm.

  14. A highly order-structured membrane electrode assembly with vertically aligned carbon nanotubes for ultra-low Pt loading PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Zhi Qun; Lim, San Hua; Poh, Chee Kok; Lin, Jianyi [Institute of Chemical and Engineering Sciences, 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Tang, Zhe; Chua, Daniel [Department of Materials Science and Engineering, National University of Singapore, Singapore 117542 (Singapore); Xia, Zetao [Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602 (Singapore); Luo, Zhiqiang; Shen, Zexiang [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore (Singapore); Shen, Pei Kang [State Key Laboratory of Optoelectronic Materials and Technologies, and Key Laboratory of Low-carbon Chemistry and Energy Conservation of Guangdong Province, School of Physics and Engineering, Sun Yat-sen University, Guangzhou, 510275 (China); Feng, Yuan Ping [Department of Physics, National University of Singapore, Singapore 117542 (Singapore)

    2011-11-15

    A simple method was developed to prepare ultra-low Pt loading membrane electrode assembly (MEA) using vertically aligned carbon nanotubes (VACNTs) as highly ordered catalyst support for PEM fuel cells application. In the method, VACNTs were directly grown on the cheap household aluminum foil by plasma enhanced chemical vapor deposition (PECVD), using Fe/Co bimetallic catalyst. By depositing a Pt thin layer on VACNTs/Al and subsequent hot pressing, Pt/VACNTs can be 100% transferred from Al foil onto polymer electrolyte membrane for the fabrication of MEA. The whole transfer process does not need any chemical removal and destroy membrane. The PEM fuel cell with the MEA fabricated using this method showed an excellent performance with ultra-low Pt loading down to 35 {mu}g cm{sup -2} which was comparable to that of the commercial Pt catalyst on carbon powder with 400 {mu}g cm{sup -2}. To the best of our knowledge, for the first time, we identified that it is possible to substantially reduce the Pt loading one order by application of order-structured electrode based on VACNTs as Pt catalysts support, compared with the traditional random electrode at a comparable performance through experimental and mathematical methods. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Development of new membrane materials for direct methanol fuel cells

    NARCIS (Netherlands)

    Yildirim, Mustafa Hakan

    2009-01-01

    Development of new membrane materials for direct methanol fuel cells Direct methanol fuel cells (DMFCs) can convert the chemical energy of a fuel directly into electrical energy with high efficiency and low emission of pollutants. DMFCs can be used as the power sources to portable electronic devices

  16. Modeling Of Proton Exchange Membrane Fuel Cell Systems

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh

    The objective of this doctoral thesis was to develop reliable steady-state and transient component models suitable to asses-, develop- and optimize proton exchange membrane (PEM) fuel cell systems. Several components in PEM fuel cell systems were characterized and modeled. The developed component...

  17. Development of new membrane materials for direct methanol fuel cells

    NARCIS (Netherlands)

    Yildirim, M.H.

    2009-01-01

    Development of new membrane materials for direct methanol fuel cells Direct methanol fuel cells (DMFCs) can convert the chemical energy of a fuel directly into electrical energy with high efficiency and low emission of pollutants. DMFCs can be used as the power sources to portable electronic devices

  18. Thin Robust Anion Exchange Membranes for Fuel Cell Applications

    Science.gov (United States)

    2014-01-01

    provide inexpensive compact power from a wider variety of fuels than is possible with a proton exchange membrane (PEM) fuel cell, has continued to...in aqueous solution. Interestingly though, while the proton transfer events in the anion exchange membrane are more frequent as would be ECS...release; distribution is unlimited. (Invited) Thin Robust Anion Exchange Membranes for Fuel Cell Applications The views, opinions and/or findings

  19. Fabrication Method for Laboratory-Scale High-Performance Membrane Electrode Assemblies for Fuel Cells.

    Science.gov (United States)

    Sassin, Megan B; Garsany, Yannick; Gould, Benjamin D; Swider-Lyons, Karen E

    2017-01-03

    Custom catalyst-coated membranes (CCMs) and membrane electrode assemblies (MEAs) are necessary for the evaluation of advanced electrocatalysts, gas diffusion media (GDM), ionomers, polymer electrolyte membranes (PEMs), and electrode structures designed for use in next-generation fuel cells, electrolyzers, or flow batteries. This Feature provides a reliable and reproducible fabrication protocol for laboratory scale (10 cm(2)) fuel cells based on ultrasonic spray deposition of a standard Pt/carbon electrocatalyst directly onto a perfluorosulfonic acid PEM.

  20. Chemical degradation mechanisms of membranes for alkaline membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Yoong-Kee [National Institute of Advanced Industrial Science and Technology, Umezono 1-1-1, Tsukuba (Japan); Henson, Neil J.; Kim, Yu Seung [Los Alamos National Laboratory, Los Alamos, NM (United States)

    2015-12-31

    Chemical degradation mechanisms of membranes for alkaline membrane fuel cells have been investigated using density functional theory (DFT). We have elucidated that the aryl-ether moiety of membranes is one of the weakest site against attack of hydroxide ions. The results of DFT calculations for hydroxide initiated aryl-ether cleavage indicated that the aryl-ether cleavage occurred prior to degradation of cationic functional group. Such a weak nature of the aryl-ether group arises from the electron deficiency of the aryl group as well as the low bond dissociation energy. The DFT results suggests that removal of the aryl-ether group in the membrane should enhance the stability of membranes under alkaline conditions. In fact, an ether fee poly(phenylene) membrane exhibits excellent stability against the attack from hydroxide ions.

  1. Novel Membrane for Highly Efficient Fuel Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Proton Exchange Membrane (PEM) fuel cells and electrolyzers are key technologies for NASA space systems utilizing hydrogen, oxygen, or water as reactants. In order...

  2. Novel High Temperature Membrane for PEM Fuel Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation proposed in this STTR program is a high temperature membrane to increase the efficiency and power density of PEM fuel cells. The NASA application is...

  3. Better Proton-Conducting Polymers for Fuel-Cell Membranes

    Science.gov (United States)

    Narayan, Sri; Reddy, Prakash

    2012-01-01

    Polyoxyphenylene triazole sulfonic acid has been proposed as a basis for development of improved proton-conducting polymeric materials for solid-electrolyte membranes in hydrogen/air fuel cells. Heretofore, the proton-conducting membrane materials of choice have been exemplified by a family of perfluorosulfonic acid-based polymers (Nafion7 or equivalent). These materials are suitable for operation in the temperature of 75 to 85 C, but in order to reduce the sizes and/or increase the energy-conversion efficiencies of fuel-cell systems, it would be desirable to increase temperatures to as high as 120 C for transportation applications, and to as high as 180 C for stationary applications. However, at 120 C and at relative humidity values below 50 percent, the loss of water from perfluorosulfonic acid-based polymer membranes results in fuel-cell power densities too low to be of practical value. Therefore, membrane electrolyte materials that have usefully high proton conductivity in the temperature range of 180 C at low relative humidity and that do not rely on water for proton conduction at 180 C would be desirable. The proposed polyoxyphenylene triazole sulfonic acid-based materials have been conjectured to have these desirable properties. These materials would be free of volatile or mobile acid constituents. The generic molecular structure of these materials is intended to exploit the fact, demonstrated in previous research, that materials that contain ionizable acid and base groups covalently attached to thermally stable polymer backbones exhibit proton conduction even in the anhydrous state.

  4. Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells

    Science.gov (United States)

    Ostroverkh, Anna; Fiala, Roman; Rednyk, Andrii; Matolín, Vladimír

    2016-01-01

    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. PMID:28042492

  5. 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.

  6. Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells.

    Science.gov (United States)

    Johánek, Viktor; Ostroverkh, Anna; Fiala, Roman; Rednyk, Andrii; Matolín, Vladimír

    2016-01-01

    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.

  7. Protonic conductors for proton exchange membrane fuel cells: An overview

    Directory of Open Access Journals (Sweden)

    Jurado Ramon Jose

    2002-01-01

    Full Text Available At present, Nation, which is a perfluorinated polymer, is one of the few materials that deliver the set of chemical and mechanical properties required to perform as a good electrolyte in proton exchange membrane fuel cells (PEMFCs. However, Nation presents some disadvantages, such as limiting the operational temperature of the fuel system (So°C, because of its inability to retain water at higher temperatures and also suffers chemical crossover. In addition to these restrictions, Nation membranes are very expensive. Reducing costs and using environmentally friendly materials are good reasons to make a research effort in this field in order to achieve similar or even better fuel-cell performances. Glass materials of the ternary system SiO2-ZrO2-P2O5, hybrid materials based on Nation, and nanopore ceramic membranes based on SiO2 TiO2, Al2O3, etc. are considered at present, as promising candidates to replace Nation as the electrolyte in PEMFCs. These types of materials are generally prepared by sol-gel processes in order to tailor their channel-porous structure and pore size. In this communication, the possible candidates in the near future as electrolytes (including other polymers different than Nation in PEMFCs are briefly reviewed. Their preparation methods, their electrical transport properties and conduction mechanisms are considered. The advantages and disadvantages of these materials with respect to Nation are also discussed.

  8. Composition analysis of a polymer electrolyte membrane fuel cell microporous layer using scanning transmission X-ray microscopy and near edge X-ray absorption fine structure analysis

    Science.gov (United States)

    George, Michael G.; Wang, Jian; Banerjee, Rupak; Bazylak, Aimy

    2016-03-01

    The novel application of scanning transmission X-ray microscopy (STXM) to the microporous layer (MPL) of a polymer electrolyte membrane fuel cell is investigated. A spatially resolved chemical component distribution map is obtained for the MPL of a commercially available SGL 25 BC sample. This is achieved with near edge X-ray absorption fine structure spectroscopic analysis. Prior to analysis the sample is embedded in non-reactive epoxy and ultra-microtomed to a thickness of 100 nm. Polytetrafluoroethylene (PTFE), carbon particle agglomerates, and supporting epoxy resin distributions are identified and reconstructed for a scanning area of 6 μm × 6 μm. It is observed that the spatial distribution of PTFE is strongly correlated to the carbon particle agglomerations. Additionally, agglomerate structures of PTFE are identified, possibly indicating the presence of a unique mesostructure in the MPL. STXM analysis is presented as a useful technique for the investigation of chemical species distributions in the MPL.

  9. Pre-oxidized and nitrided stainless steel alloy foil for proton exchange membrane fuel cell bipolar plates: Part 1. Corrosion, interfacial contact resistance, and surface structure

    Science.gov (United States)

    Brady, M. P.; Wang, H.; Turner, J. A.; Meyer, H. M.; More, K. L.; Tortorelli, P. F.; McCarthy, B. D.

    Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr 2N, CrN, TiN, V 2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2× the target value. Pre-oxidized and nitrided surface structure examination revealed surface-through-layer-thickness V-nitride particles for the treated Fe-20Cr-4V, but near continuous chromia for treated 2205 stainless steel, which was linked to the variation in ICR values. Promising corrosion resistance was observed under simulated aggressive PEMFC anode- and cathode-side bipolar plate conditions for both materials, although ICR values were observed to increase. The implications of these findings for stamped bipolar plate foils are discussed.

  10. Development of membrane electrode assemblies for solid polymer fuel cells with higher performance, lower cost and carbon monoxide tolerance: improved cathode structures

    Energy Technology Data Exchange (ETDEWEB)

    Ralph, T.; Collis, N.; Edwards, N.

    1997-09-01

    Pre-commercial prototype solid polymer fuel cell (SPFC) modules and systems are presently available for sale. The widespread use of the technology has been limited, however, principally because of the high capital cost and insufficient power density. The UK Department of Trade and Industry`s Advanced Fuel Cells R and D Strategy has identified that the SPFC could, after appropriate development, be suitable for small scale combined heat and power and transportation applications in the UK. Key technology developments required to meet the cost and performance targets include increasing the power density of the membrane electrode assembly (MEA), reducing the platinum loading of the electrode materials and identifying anode catalysts with increased tolerance to reformate operation. The objectives of this project were to establish a SPFC single cell test facility at Johnson Matthey Technology Centre (JMTC) and evaluate the performance of a multicomponent cathode structure developed in a previous DTI supported project. The cathode combined two components in a multicomponent layer. This comprised an `ionomer` component consisting of a platinum catalyst which had been pre-impregnated with soluble polymer electrolyte, to enhance the platinum utilisation. This component was intimately mixed with a `gas transport` component, composed of a carbon/PTFE mixture, to provide gas transport channels. A Nafion surface coating to link together isolated pockets of `ionomer` component in the electrode depth completed the fabrication. (Author)

  11. 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...

  12. New proton conducting membranes for fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Sukumar, P.R.

    2006-07-01

    In order to synthesize proton-conducting materials which retain acids in the membrane during fuel cell operating conditions, the synthesis of poly(vinylphosphonic acid) grafted polybenzimidazole (PVPA grafted PBI) and the fabrication of multilayer membranes are mainly focussed in this dissertation. Synthesis of PVPA grafted PBI membrane can be done according to ''grafting through'' method. In ''grafting through'' method (or macromonomer method), monomer (e.g., vinylphosphonic acid) is radically copolymerized with olefin group attached macromonomer (e.g., allyl grafted PBI and vinylbenzyl grafted PBI). This approach is inherently limited to synthesize graft-copolymer with well-defined architectural and structural parameters. The incorporation of poly(vinylphosphonic acid) into PBI lead to improvements in proton conductivity up to 10-2 S/cm. Regarding multilayer membranes, the proton conducting layer-by-layer (LBL) assembly of polymers by various strong acids such as poly(vinylphosphonic acid), poly(vinylsulfonic acid) and poly(styrenesulfonic acid) paired with basic polymers such as poly(4-vinylimidazole) and poly(benzimidazole), which are appropriate for Proton Exchange Membrane Fuel Cell applications have been described. Proton conductivity increases with increasing smoothness of the film and the maximum measured conductivity was 10-4 S/cm at 25A C. Recently, anhydrous proton-conducting membranes with flexible structural backbones, which show proton-conducting properties comparable to Nafion have been focus of current research. The flexible backbone of polymer chains allow for a high segmental mobility and thus, a sufficiently low glass transition temperature (Tg), which is an essential factor to reach highly conductive systems. Among the polymers with a flexible chain backbone, poly(vinylphosphonic acid), poly(vinylbenzylphosphonic acid), poly(2-vinylbenzimidazole), poly(4-styrenesulfonic acid), poly(4-vinylimidazole), poly

  13. Electron Spin Resonance Study of Fuel Cell Polymer Membrane Degradation

    Institute of Scientific and Technical Information of China (English)

    Alexander Panchenko; Elena Aleksandrova; Emil Roduner

    2005-01-01

    @@ 1Introduction The long term stability of the membrane is an important factor limiting the fuel cell lifetime. During extended use the membrane degrades, probably via reaction with hydroxyl and superoxide radicals which are regular intermediates of the oxygen reduction at the cathode. Only extremely stable membranes can withstand the aggressive chemical and physical environment in an operating fuel cell. Within a given set of operating conditions, intrinsic chemical and mechanical properties of the membrane as well as its water content impact its durability dramatically.

  14. Proton exchange membrane fuel cell technology for transportation applications

    Energy Technology Data Exchange (ETDEWEB)

    Swathirajan, S. [General Motors R& D Center, Warren, MI (United States)

    1996-04-01

    Proton Exchange Membrane (PEM) fuel cells are extremely promising as future power plants in the transportation sector to achieve an increase in energy efficiency and eliminate environmental pollution due to vehicles. GM is currently involved in a multiphase program with the US Department of Energy for developing a proof-of-concept hybrid vehicle based on a PEM fuel cell power plant and a methanol fuel processor. Other participants in the program are Los Alamos National Labs, Dow Chemical Co., Ballard Power Systems and DuPont Co., In the just completed phase 1 of the program, a 10 kW PEM fuel cell power plant was built and tested to demonstrate the feasibility of integrating a methanol fuel processor with a PEM fuel cell stack. However, the fuel cell power plant must overcome stiff technical and economic challenges before it can be commercialized for light duty vehicle applications. Progress achieved in phase I on the use of monolithic catalyst reactors in the fuel processor, managing CO impurity in the fuel cell stack, low-cost electrode-membrane assembles, and on the integration of the fuel processor with a Ballard PEM fuel cell stack will be presented.

  15. 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....

  16. Modeling Of Proton Exchange Membrane Fuel Cell Systems

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh

    The objective of this doctoral thesis was to develop reliable steady-state and transient component models suitable to asses-, develop- and optimize proton exchange membrane (PEM) fuel cell systems. Several components in PEM fuel cell systems were characterized and modeled. The developed component...... cell systems. Consequences of indirectly fueling PEM stacks with hydrocarbons using reforming technology were investigated using a PEM stack model including CO poisoning kinetics and a transient Simulink steam reforming system model. Aspects regarding the optimization of PEM fuel cell systems...

  17. 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.

  18. Design & development of innovative proton exchange membrane fuel cells

    OpenAIRE

    Carton, James

    2011-01-01

    The research undertaken in this thesis is concerned with the design and development of Proton Exchange Membrane (PEM) fuel cells and provides a body of information for continued PEM fuel cell development, which will ideally aid in the future commercialisation of these electrochemical devices. Through a combination of numerical analysis, computational fluid dynamic modelling and experimental work, effective flow plate designs, flow field configurations and materials are analysed and new inn...

  19. Solid alkaline membrane fuel cell : what are they advantages and drawbacks compared to proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Coutanceau, C.; Baranton, S.; Simoes, M. [Univ. de Poitiers, Poitiers (France). Laboratoire de Catalyse en Chimie Organique, UMR CNRS

    2010-07-01

    Low temperature fuel cells such as proton exchange membrane fuel cells (PEMFCs) and direct alcohol fuel cells (DAFCs) are promising power sources for portable electronics and transportation applications. However, these fuel cells require high amounts of platinum at the anodes to achieve high cell performance. Although alkaline membrane fuel cells (AFCs) may be an alternative to PEMFCs, the technology of low temperature fuel cells is less developed than that of fuel cells working with a solid acid electrolyte. Interest in solid alkaline membrane fuel cells (SAMFCs) has increased in recent years because it is easier to activate the oxidation and reduction reactions in alkaline medium than in acidic medium. Fewer platinum based catalysts are needed due to higher electrode kinetics. The development of hydroxyl conductive membrane makes this technology available, but the fuel to be used in the system must be considered. Pure hydrogen or hydrogen-rich gases offer high electric efficiency, but their production, storage, and distribution are not sufficient for a large-scale development. This paper discussed the relatively good electroreactivity of polyols such as glycerol and ethylene glycol in a SAMFC, as well as sodium borohydride (NaBH{sub 4}) as an alternative. The working principle of SAMFCs was also presented along with considerations regarding the electrochemical reactions occurring at the electrodes, and requirements concerning the catalysts, the triple phase boundary in the electrode and the anionic membrane. Palladium based catalysts were found to be an interesting alternative to platinum in SAMFCs. In situ FTIR measurements and oxidation products analysis was used to determine the electrooxidation pathways of alcohol and NaBH{sub 4}in alkaline medium. The study also included a comparison with oxidation mechanisms in acid medium. 8 refs.

  20. Characterization and fuel cell performance analysis of polyvinylalcohol-mordenite mixed-matrix membranes for direct methanol fuel cell use

    Energy Technology Data Exchange (ETDEWEB)

    Uctug, Fehmi Goerkem, E-mail: gorkem.uctug@bahcesehir.edu.t [University of Manchester, School of Chemical Engineering and Analytical Science, M60 1QD (United Kingdom); Holmes, Stuart M. [University of Manchester, School of Chemical Engineering and Analytical Science, M60 1QD (United Kingdom)

    2011-10-01

    Highlights: > We investigated the availability of PVA-mordenite membranes for DMFC use. > We measured the methanol permeability of PVA-mordenite membranes via pervaporation. > We did the fuel cell testing of these membranes, which had not been done before. > We showed that PVA-mordenite membranes have poorer DMFC performance than Nafion. > Membrane performance can be improved by increasing the proton conductivity of PVA. - Abstract: Polyvinylalcohol-mordenite (PVA-MOR) mixed matrix membranes were synthesized for direct methanol fuel cell (DMFC) use. For the structural and the morphological characterization, Scanning Electron Microscopy and Thermal Gravimetric Analysis methods were used. Zeolite distribution within the polymer matrix was found to be homogeneous. An impedance spectroscope was used to measure the proton conductivity. In order to obtain information about methanol permeation characteristics, swelling tests and a series of pervaporation experiments were carried out. 60-40 wt% PVA-MOR membranes were found to give the optimum transport properties. Proton conductivity of these membranes was found to be slightly lower than that of Nafion117{sup TM} whereas their methanol permeability was at least two orders of magnitude lower than Nafion117{sup TM}. DMFC performance of the PVA-MOR membranes was also measured. The inferior DMFC performance of PVA-MOR membranes was linked to drying in the fuel cell medium and the consequent proton conductivity loss. Their performance was improved by adding a dilute solution of sulfuric acid into the feed methanol solution. Future studies on the improvement of the proton conductivity of PVA-MOR membranes, especially via sulfonation of the polymer matrix, can overcome the low-performance problem associated with insufficient proton conductivity.

  1. 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.

  2. Fundamental study of mechanical and chemical degradation mechanisms of PEM fuel cell membranes

    Science.gov (United States)

    Yoon, Wonseok

    mechanical stress necessitates the prediction of the stress distribution in the membrane under various conditions. One of research focuses was on the developing micromechanism-inspired continuum model for ionomer membranes. The model is the basis for stress analysis, and is based on a hyperelastic model with reptation-inspired viscous flow rule and multiplicative decomposition of viscoelastic and plastic deformation gradient. Finally, evaluation of the membrane degradation requires a fuel cell model since the degradation occurs under fuel cell operating conditions. The fuel cell model included structural mechanics models and multiphysics models which represents other phenomena such as gas and water transport, charge conservation, electrochemical reactions, and energy conservation. The combined model was developed to investigate the compression effect on fuel cell performance and membrane stress distribution.

  3. Water management in proton exchange membrane fuel cells using integrated electroosmotic pumping

    Science.gov (United States)

    Buie, Cullen R.; Posner, Jonathan D.; Fabian, Tibor; Cha, Suk-Won; Kim, Daejoong; Prinz, Fritz B.; Eaton, John K.; Santiago, Juan G.

    Recent experimental and numerical investigations on proton exchange membrane fuel cells (PEMFCs) emphasize water management as a critical factor in the design of robust, high efficiency systems. Although various water management strategies have been proposed, water is still typically removed by pumping air into cathode channels at flow rates significantly higher than required by fuel cell stoichiometry. Such methods are thermodynamically unfavorable and constrain cathode flow channel design. We have developed proton exchange membrane fuel cells (PEMFCs) with integrated planar electroosmotic (EO) pumping structures that actively remove liquid water from cathode flow channels. EO pumps can relieve cathode design barriers and facilitate efficient water management in fuel cells. EO pumps have no moving parts, scale appropriately with fuel cells, operate across a wide range of conditions, and consume a small fraction of fuel cell power. We demonstrate and quantify the efficacy of EO water pumping using controlled experiments in a single channel cathode flow structure. Our results show that, under certain operating conditions, removing water from the cathode using integrated EO pumping structures improves fuel cell performance and stability. The application of EO pumps for liquid water removal from PEMFC cathodes extends their operational range and reduces air flow rates.

  4. Water management in proton exchange membrane fuel cells using integrated electroosmotic pumping

    Energy Technology Data Exchange (ETDEWEB)

    Buie, Cullen R.; Posner, Jonathan D.; Fabian, Tibor; Cha, Suk-Won; Kim, Daejoong; Prinz, Fritz B.; Eaton, John K.; Santiago, Juan G. [Department of Mechanical Engineering, Stanford University, Stanford, CA 94305 (United States)

    2006-10-20

    Recent experimental and numerical investigations on proton exchange membrane fuel cells (PEMFCs) emphasize water management as a critical factor in the design of robust, high efficiency systems. Although various water management strategies have been proposed, water is still typically removed by pumping air into cathode channels at flow rates significantly higher than required by fuel cell stoichiometry. Such methods are thermodynamically unfavorable and constrain cathode flow channel design. We have developed proton exchange membrane fuel cells (PEMFCs) with integrated planar electroosmotic (EO) pumping structures that actively remove liquid water from cathode flow channels. EO pumps can relieve cathode design barriers and facilitate efficient water management in fuel cells. EO pumps have no moving parts, scale appropriately with fuel cells, operate across a wide range of conditions, and consume a small fraction of fuel cell power. We demonstrate and quantify the efficacy of EO water pumping using controlled experiments in a single channel cathode flow structure. Our results show that, under certain operating conditions, removing water from the cathode using integrated EO pumping structures improves fuel cell performance and stability. The application of EO pumps for liquid water removal from PEMFC cathodes extends their operational range and reduces air flow rates. (author)

  5. Graphene-doped electrospun nanofiber membrane electrodes and proton exchange membrane fuel cell performance

    Science.gov (United States)

    Wei, Meng; Jiang, Min; Liu, Xiaobo; Wang, Min; Mu, Shichun

    2016-09-01

    A rational electrode structure can allow proton exchange membrane (PEM) fuel cells own high performance with a low noble metal loading and an optimal transport pathway for reaction species. In this study, we develop a graphene doped polyacrylonitile (PAN)/polyvinylident fluoride (PVDF) (GPP) electrospun nanofiber electrode with improved electrical conductivity and high porosity, which could enhance the triple reaction boundary and promote gas and water transport throughout the porous electrode. Thus the increased electrochemical active surface area (ECSA) of Pt catalysts and fuel cell performance can be expected. As results, the ECSA of hot-pressed electrospun electrodes with 2 wt% graphene oxide (GO) is up to 84.3 m2/g, which is greatly larger than that of the conventional electrode (59.5 m2/g). Significantly, the GPP nanofiber electrospun electrode with Pt loading of 0.2 mg/cm2 exhibits higher fuel cell voltage output and stability than the conventional electrode.

  6. Understanding the transport processes in polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Cheah, May Jean

    Polymer electrolyte membrane (PEM) fuel cells are energy conversion devices suitable for automotive, stationary and portable applications. An engineering challenge that is hindering the widespread use of PEM fuel cells is the water management issue, where either a lack of water (resulting in membrane dehydration) or an excess accumulation of liquid water (resulting in fuel cell flooding) critically reduces the PEM fuel cell performance. The water management issue is addressed by this dissertation through the study of three transport processes occurring in PEM fuel cells. Water transport within the membrane is a combination of water diffusion down the water activity gradient and the dragging of water molecules by protons when there is a proton current, in a phenomenon termed electro-osmotic drag, EOD. The impact of water diffusion and EOD on the water flux across the membrane is reduced due to water transport resistance at the vapor/membrane interface. The redistribution of water inside the membrane by EOD causes an overall increase in the membrane resistance that regulates the current and thus EOD, thereby preventing membrane dehydration. Liquid water transport in the PEM fuel cell flow channel was examined at different gas flow regimes. At low gas Reynolds numbers, drops transitioned into slugs that are subsequently pushed out of the flow channel by the gas flow. The slug volume is dependent on the geometric shape, the surface wettability and the orientation (with respect to gravity) of the flow channel. The differential pressure required for slug motion primarily depends on the interfacial forces acting along the contact lines at the front and the back of the slug. At high gas Reynolds number, water is removed as a film or as drops depending on the flow channel surface wettability. The shape of growing drops at low and high Reynolds number can be described by a simple interfacial energy minimization model. Under flooding conditions, the fuel cell local current

  7. Structural and wetting properties of fuel cell components

    Science.gov (United States)

    Volfkovich, Yu. M.; Sosenkin, V. E.; Bagotsky, V. S.

    The operation of proton exchange membrane (PEMFC) and direct methanol fuel cells (DMFC) is connected with the flow of different gaseous and liquid components in the cell's membrane-electrode assembly (MEA). The structural and wetting properties of different components of the MEA influence the rate and direction of these flows and hence the fuel cell's efficiency. For a better understanding of the mechanism of all processes influencing the fuel cell efficiency, for a mathematical modelling of these processes, and for a possibility of their optimization, a detailed knowledge of the geometrical structure and wetting properties of all MEA components is necessary. This review describes the results of such investigations performed mainly by using the method of standard contact porosimetry (MSCP). This method gives the possibility to receive information on multicomponent porous and powdered materials hitherto not accessible, viz. their wetting and swelling properties, pore corrugation, and also isotherms of capillary pressure and bond energy. Measurements of MEA components by this method can be performed under exactly the same conditions (temperature, compression degree, contact with water, etc.) as those existing in real fuel cells.

  8. Gold Nanoparticles-Enhanced Proton Exchange Membrane (PEM) Fuel Cell

    Science.gov (United States)

    Li, Hongfei; Pan, Cheng; Liu, Ping; Zhu, Yimei; Adzic, Radoslav; Rafailovich, Miriam

    Proton exchange membrane fuel cells have drawn great attention and been taken as a promising alternated energy source. One of the reasons hamper the wider application of PEM fuel cell is the catalytic poison effect from the impurity of the gas flow. Haruta has predicted that gold nanoparticles that are platelet shaped and have direct contact with the metal oxide substrate to be the perfect catalysts of the CO oxidization, yet the synthesis method is difficult to apply in the Fuel Cell. In our approach, thiol-functionalized gold nanoparticles were synthesized through two-phase method developed by Brust et al. We deposit these Au particles with stepped surface directly onto the Nafion membrane in the PEM fuel cell by Langmuir-Blodgett method, resulting in over 50% enhancement of the efficiency of the fuel cell. DFT calculations were conducted to understand the theory of this kind of enhancement. The results indicated that only when the particles were in direct surface contact with the membrane, where AuNPs attached at the end of the Nafion side chains, it could reduce the energy barrier for the CO oxidation that could happen at T<300K.

  9. Microfluidic microbial fuel cells: from membrane to membrane free

    Science.gov (United States)

    Yang, Yang; Ye, Dingding; Li, Jun; Zhu, Xun; Liao, Qiang; Zhang, Biao

    2016-08-01

    Microfluidic microbial fuel cells (MMFCs) are small carbon-neutral devices that use self-organized bacteria to degrade organic substrates and harness energy from the waste water. Conventional MMFCs have made great strides in the past decade and have overcome some limitations, such as high capital costs and low energy output. A co-laminar flow MFC has been first proposed in 2011 with the potential to be an attractively power source to niche applications. Co-laminar MFCs typically operate without any physical membranes separating the reactants, and bacterial ecosystems can be easily manipulated by regulating the inlet conditions. This paper highlights recent accomplishments in the development of co-laminar MFCs, emphasizing basic principles, mass transport and fluid dynamics including boundary layer theory, entrance conditions and mixing zone issues. Furthermore, the development of current techniques, major challenges and the potential research directions are discussed.

  10. Durable Catalysts for High Temperature Proton Exchange Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Durability of proton exchange membrane fuel cells (PEMFCs) is recognized as one of the most important issues to be addressed before the commercialization. The failure mechanisms are not well understood, however, degradation of carbon supported noble metal catalysts is identified as a major failure...... corrosion, in turn, triggers the agglomeration of platinum particles resulting in reduction of the active surface area and catalytic activity. This is a major mechanism of the catalyst degradation and a key challenge to the PEMFC long-term durability. High temperature PEMFC, on the other hand, has attached...... the selectivity for platinum loading. Fuel cell durability tests in term of performance degradation were performed with acid doped polybenzimidazole membrane fuel cells at temperatures of up to 160°C. The tests were focused on catalyst degradation by means of a potential cycling protocol. The electrochemical...

  11. Anion permselective membrane. [For redox fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, S.S.; Hodgdon, R.B.

    1978-01-01

    Experimental anion permeselective membranes were improved and characterized for use as separators in a chemical redox, power storage cell being developed at the NASA Lewis Research Center. The goal of minimal Fe/sup +3/ ion transfer was achieved for each candidate membrane system. Minimal membrane resistivity was demonstrated by reduction of film thickness using synthetic backing materials but usefulness of thin membranes was limited by the scarcity of compatible fabrics. The most durable and useful backing fabrics were modacrylics. One membrane, a copolymer of 4 vinylpyridine and vinyl benzylchloride was outstanding in overall electrochemical and physical properties. Long term (1000 hrs) membrane chemical and thermal durability in redox environment was shown by three candidate polymers and two membranes. The remainder had good durability at ambient temperature. Manufacturing capability was demonstrated for large scale production of membrane sheets 5.5 ft/sup 2/ in area for two candidate systems.

  12. Stimulated-healing of proton exchange membrane fuel cell catalyst

    NARCIS (Netherlands)

    Latsuzbaia, R.; Negro, E.; Koper, G.J.M.

    2013-01-01

    Platinum nanoparticles, which are used as catalysts in Proton Exchange Membrane Fuel Cells (PEMFC), tend to degrade after long-term operation. We discriminate the following mechanisms of the degradation: poisoning, migration and coalescence, dissolution, and electrochemical Ostwald ripening. There a

  13. Spray deposition of Nafion membranes: Electrode-supported fuel cells

    Science.gov (United States)

    Bayer, Thomas; Pham, Hung Cuong; Sasaki, Kazunari; Lyth, Stephen Matthew

    2016-09-01

    Fuel cells are a key technology for the successful transition towards a hydrogen society. In order to accelerate fuel cell commercialization, improvements in performance are required. Generally, polymer electrolyte membrane fuel cells (PEFCs) are membrane-supported; the electrocatalyst layer is sprayed onto both sides of the membrane, and sandwiched between carbon-based gas diffusion layers (GDLs). In this work we redesign the membrane electrode assembly (MEA) and fabricate an electrode-supported PEFC. First the electrocatalyst layer is sprayed onto the GDL, and then Nafion dispersion is sprayed over the top of this to form a thin membrane. This method has the advantage of simplifying the fabrication process, allowing the fabrication of extremely thin electrolyte layers (down to ∼10 μm in this case), and reducing the amount of ionomer required in the cell. Electrode-supported PEFCs operate at significantly increased power density compared to conventional membrane-supported PEFCs, with a maximum of 581 mW/cm2 at 80 °C (atmospheric pressure, air at the cathode). Impedance spectroscopy confirmed that the origin of the improved performance was an 80% reduction in the membrane resistance due the thinner Nafion layer. This novel fabrication method is a step towards cheaper, thinner, fully printable PEFCs with high power density and efficiency.

  14. Alkaline direct alcohol fuel cells using an anion exchange membrane

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Koji; Iriyama, Yasutoshi; Abe, Takeshi; Ogumi, Zempachi [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); Matsuoka, Masao [Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan)

    2005-10-04

    Alkaline direct alcohol fuel cells using an OH-form anion exchange membrane and polyhydric alcohols were studied. A high open circuit voltage of ca. 800mV was obtained for a cell using Pt-Ru/C (anode) and Pt/C (cathode) at 323K, which was about 100-200mV higher than that for a DMFC using Nafion{sup R}. The maximum power densities were in the order of ethylene glycol>glycerol>methanol>erythritol>xylitol. Silver catalysts were used as a cathode catalyst to fabricate alkaline fuel cells, since silver catalyst is almost inactive in the oxidation of polyhydric alcohols. Alkaline direct ethylene glycol fuel cells using silver as a cathode catalyst gave excellent performance because higher concentrations of fuel could be supplied to the anode. (author)

  15. Physical Chemistry Research Toward Proton Exchange Membrane Fuel Cell Advancement.

    Science.gov (United States)

    Swider-Lyons, Karen E; Campbell, Stephen A

    2013-02-07

    Hydrogen fuel cells, the most common type of which are proton exchange membrane fuel cells (PEMFCs), are on a rapid path to commercialization. We credit physical chemistry research in oxygen reduction electrocatalysis and theory with significant breakthroughs, enabling more cost-effective fuel cells. However, most of the physical chemistry has been restricted to studies of platinum and related alloys. More work is needed to better understand electrocatalysts generally in terms of properties and characterization. While the advent of such highly active catalysts will enable smaller, less expensive, and more powerful stacks, they will require better understanding and a complete restructuring of the diffusion media in PEMFCs to facilitate faster transport of the reactants (O2) and products (H2O). Even Ohmic losses between materials become more important at high power. Such lessons from PEMFC research are relevant to other electrochemical conversion systems, including Li-air batteries and flow batteries.

  16. Innovative membrane development for fuel cells

    CSIR Research Space (South Africa)

    Vaivars, G

    2011-10-01

    Full Text Available The innovative membranes for alternative energy devices will be presented. An electrical car is long waited solution to environmental and fuel supply problems in transport. Most probably, the shift from a combustion engine to an electrical car...

  17. Scalable nanostructured membranes for solid-oxide fuel cells.

    Science.gov (United States)

    Tsuchiya, Masaru; Lai, Bo-Kuai; Ramanathan, Shriram

    2011-05-01

    The use of oxide fuel cells and other solid-state ionic devices in energy applications is limited by their requirement for elevated operating temperatures, typically above 800°C (ref. 1). Thin-film membranes allow low-temperature operation by reducing the ohmic resistance of the electrolytes. However, although proof-of-concept thin-film devices have been demonstrated, scaling up remains a significant challenge because large-area membranes less than ~ 100 nm thick are susceptible to mechanical failure. Here, we report that nanoscale yttria-stabilized zirconia membranes with lateral dimensions on the scale of millimetres or centimetres can be made thermomechanically stable by depositing metallic grids on them to function as mechanical supports. We combine such a membrane with a nanostructured dense oxide cathode to make a thin-film solid-oxide fuel cell that can achieve a power density of 155 mW cm⁻² at 510 °C. We also report a total power output of more than 20 mW from a single fuel-cell chip. Our large-area membranes could also be relevant to electrochemical energy applications such as gas separation, hydrogen production and permeation membranes.

  18. Crosslinking and alkyl substitution in nano-structured grafted fluoropolymer for use as proton-exchange membranes in fuel cells

    DEFF Research Database (Denmark)

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

    2009-01-01

    of the crosslinking agent divinylbenzene has been investigated and its amount optimized. Substitution of styrene by methylstyrene and t-butylstyrene has been performed with the purpose of improving the chemical stability of the membranes. Grafting with a fraction of divinylbenzene in the order of 1-2 vol......-% of the total monomers has been found to be the best compromise between high grafting yield, good chemical stability, and high proton conductivity of the final membrane. The use of methylstyrene and t-butylstyrene as grafting monomers instead of styrene results in substantially increased chemical stability......, with reasonable proton conductivity still being possible to obtain....

  19. Nanoporous gold membranes: From morphological control to fuel cell catalysis

    Science.gov (United States)

    Ding, Yi

    stable, low Pt usage, and better tolerance to CO poisoning. We incorporated it as a membrane electrode into a working proton exchange membrane fuel cells (PEMFC). Preliminary results show that Pt/NPG has very good fuel cell performance at a very low platinum loading.

  20. Multiphase transport in polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Gauthier, Eric D.

    Polymer electrolyte membrane fuel cells (PEMFCs) enable efficient conversion of fuels to electricity. They have enormous potential due to the high energy density of the fuels they utilize (hydrogen or alcohols). Power density is a major limitation to wide-scale introduction of PEMFCs. Power density in hydrogen fuel cells is limited by accumulation of water in what is termed fuel cell `flooding.' Flooding may occur in either the gas diffusion layer (GDL) or within the flow channels of the bipolar plate. These components comprise the electrodes of the fuel cell and balance transport of reactants/products with electrical conductivity. This thesis explores the role of electrode materials in the fuel cell and examines the fundamental connection between material properties and multiphase transport processes. Water is generated at the cathode catalyst layer. As liquid water accumulates it will utilize the largest pores in the GDL to go from the catalyst layer to the flow channels. Water collects to large pores via lateral transport at the interface between the GDL and catalyst layer. We have shown that water may be collected in these large pores from several centimeters away, suggesting that we could engineer the GDL to control flooding with careful placement and distribution of large flow-directing pores. Once liquid water is in the flow channels it forms slugs that block gas flow. The slugs are pushed along the channel by a pressure gradient that is dependent on the material wettability. The permeable nature of the GDL also plays a major role in slug growth and allowing bypass of gas between adjacent channels. Direct methanol fuel cells (DMFCs) have analogous multiphase flow issues where carbon dioxide bubbles accumulate, `blinding' regions of the fuel cell. This problem is fundamentally similar to water management in hydrogen fuel cells but with a gas/liquid phase inversion. Gas bubbles move laterally through the porous GDL and emerge to form large bubbles within the

  1. Application of Proton Exchange Membrane Fuel Cell for Lift Trucks

    DEFF Research Database (Denmark)

    Hosseinzadeh, Elham; Rokni, Masoud

    2011-01-01

    In this study a general PEMFC (Proton Exchange Membrane Fuel Cell) model has been developed to take into account the effect of pressure losses, water crossovers, humidity aspects and voltage over potentials in the cells. The model is zero dimensional and it is assumed to be steady state. The effect...... in order to account for water back diffusion. Further Membrane water content is assumed to be a linear function of thickness. PEM fuel cell is working at rather low operating conditions which makes it suitable for the automotive systems. In this paper motive power part of a lift truck has been investigated...... of concentration loss is neglected while the effect of activation and ohmic losses is investigated in the system. Some semi-empirical equations are required to predict the amount of exchange current density for calculation of ohmic loss and water diffusion coefficient through membrane. These equations are applied...

  2. Polymer Electrolyte Membrane (PEM) Fuel Cells Modeling and Optimization

    Science.gov (United States)

    Zhang, Zhuqian; Wang, Xia; Shi, Zhongying; Zhang, Xinxin; Yu, Fan

    2006-11-01

    Performance of polymer electrolyte membrane (PEM) fuel cells is dependent on operating parameters and designing parameters. Operating parameters mainly include temperature, pressure, humidity and the flow rate of the inlet reactants. Designing parameters include reactants distributor patterns and dimensions, electrodes dimensions, and electrodes properties such as porosity, permeability and so on. This work aims to investigate the effects of various designing parameters on the performance of PEM fuel cells, and the optimum values will be determined under a given operating condition.A three-dimensional steady-state electrochemical mathematical model was established where the mass, fluid and thermal transport processes are considered as well as the electrochemical reaction. A Powell multivariable optimization algorithm will be applied to investigate the optimum values of designing parameters. The objective function is defined as the maximum potential of the electrolyte fluid phase at the membrane/cathode interface at a typical value of the cell voltage. The robustness of the optimum design of the fuel cell under different cell potentials will be investigated using a statistical sensitivity analysis. By comparing with the reference case, the results obtained here provide useful tools for a better design of fuel cells.

  3. Solid Polymer Fuel Cells. Electrode and membrane performance studies

    Energy Technology Data Exchange (ETDEWEB)

    Moeller-Holst, S.

    1996-12-31

    This doctoral thesis studies aspects of fuel cell preparation and performance. The emphasis is placed on preparation and analysis of low platinum-loading solid polymer fuel cell (SPEC) electrodes. A test station was built and used to test cells within a wide range of real operating conditions, 40-150{sup o}C and 1-10 bar. Preparation and assembling equipment for single SPFCs was designed and built, and a new technique of spraying the catalyst layer directly onto the membrane was successfully demonstrated. Low Pt-loading electrodes (0.1 mg Pt/cm{sup 2}) prepared by the new technique exhibited high degree of catalyst utilization. The performance of single cells holding these electrodes is comparable to state-of-the-art SPFCs. Potential losses in single cell performance are ascribed to irreversibilities by analysing the efficiency of the Solid Oxide Fuel Cell by means of the second law of thermodynamics. The water management in membranes is discussed for a model system and the results are relevant to fuel cell preparation and performance. The new spray deposition technique should be commercially interesting as it involves few steps as well as techniques that are adequate for larger scale production. 115 refs., 43 figs., 18 tabs.

  4. Solid Polymer Fuel Cells. Electrode and membrane performance studies

    Energy Technology Data Exchange (ETDEWEB)

    Moeller-Holst, S.

    1996-12-31

    This doctoral thesis studies aspects of fuel cell preparation and performance. The emphasis is placed on preparation and analysis of low platinum-loading solid polymer fuel cell (SPEC) electrodes. A test station was built and used to test cells within a wide range of real operating conditions, 40-150{sup o}C and 1-10 bar. Preparation and assembling equipment for single SPFCs was designed and built, and a new technique of spraying the catalyst layer directly onto the membrane was successfully demonstrated. Low Pt-loading electrodes (0.1 mg Pt/cm{sup 2}) prepared by the new technique exhibited high degree of catalyst utilization. The performance of single cells holding these electrodes is comparable to state-of-the-art SPFCs. Potential losses in single cell performance are ascribed to irreversibilities by analysing the efficiency of the Solid Oxide Fuel Cell by means of the second law of thermodynamics. The water management in membranes is discussed for a model system and the results are relevant to fuel cell preparation and performance. The new spray deposition technique should be commercially interesting as it involves few steps as well as techniques that are adequate for larger scale production. 115 refs., 43 figs., 18 tabs.

  5. Silica based composite membranes for methanol fuel cells operating at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, A.; Guzman, C.; Peza-Ledesma, C.; Godinez, Luis A.; Nava, R.; Duron-Torres, S.M.; Ledesma-Garcia, J.; Arriaga, L.G.

    2011-01-15

    Direct methanol fuel cells (DMFCs) are seen as an alternative energy source for several applications, particularly portable power sources. Nafion membranes constitute a well known proton exchange system for DMFC systems due to their convenient electrochemical, mechanical and thermal stability and high proton conductivity properties. But there are problems currently associated with the direct methanol fuel cell technology. Intensive efforts to decrease the methanol crossover are focused mainly on the development of new polymer electrolyte membranes. In this study, Nafion polymer was modified by means of the incorporation of inorganic oxides with different structural properties (SBA-15 and SiO2), both prepared by sol-gel method in order to increase the proton conductivity at high temperature of fuel cell and to contribute decrementing the methanol crossover effect. Composite membranes based in inorganic fillers showed a significant decrease in the concentration of methanol permeation.

  6. Alkaline Exchange Membrane (AEM) for High-Efficiency Fuel Cells, Electrolyzers and Regenerative Fuel Cell Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop an alkaline exchange membrane (AEM)for use as a polymer electrolyte in both fuel cell and electrolyzer systems.  The ultimate goal in AEM development is...

  7. High temperature proton exchange membranes based on polybenzimidazoles for fuel cells

    DEFF Research Database (Denmark)

    Li, Qingfeng; Jensen, Jens Oluf; Savinell, Robert F

    2009-01-01

    To achieve high temperature operation of proton exchange membrane fuel cells (PEMFC), preferably under ambient pressure, acid–base polymer membranes represent an effective approach. The phosphoric acid-doped polybenzimidazole membrane seems so far the most successful system in the field. It has...... in recent years motivated extensive research activities with great progress. This treatise is devoted to updating the development, covering polymer synthesis, membrane casting, physicochemical characterizations and fuel cell technologies. To optimize the membrane properties, high molecular weight polymers...... with synthetically modified or N-substituted structures have been synthesized. Techniques for membrane casting from organic solutions and directly from acid solutions have been developed. Ionic and covalent cross-linking as well as inorganic–organic composites has been explored. Membrane characterizations...

  8. Novel niobium carbide/carbon porous nanotube electrocatalyst supports for proton exchange membrane fuel cell cathodes

    Science.gov (United States)

    Nabil, Y.; Cavaliere, S.; Harkness, I. A.; Sharman, J. D. B.; Jones, D. J.; Rozière, J.

    2017-09-01

    Niobium carbide/carbon nanotubular porous structures have been prepared using electrospinning and used as electrocatalyst supports for proton exchange membrane fuel cells. They were functionalised with 3.1 nm Pt particles synthesised by a microwave-assisted polyol method and characterised for their electrochemical properties. The novel NbC-based electrocatalyst demonstrated electroactivity towards the oxygen reduction reaction as well as greater stability over high potential cycling than a commercial carbon-based electrocatalyst. Pt/NbC/C was integrated at the cathode of a membrane electrode assembly and characterised in a single fuel cell showing promising activity and power density.

  9. Mathematical and Computational Modeling of Polymer Exchange Membrane Fuel Cells

    Science.gov (United States)

    Ulusoy, Sehribani

    In this thesis a comprehensive review of fuel cell modeling has been given and based on the review, a general mathematical fuel cell model has been developed in order to understand the physical phenomena governing the fuel cell behavior and in order to contribute to the efforts investigating the optimum performance at different operating conditions as well as with different physical parameters. The steady state, isothermal model presented here accounts for the combined effects of mass and species transfer, momentum conservation, electrical current distribution through the gas channels, the electrodes and the membrane, and the electrochemical kinetics of the reactions in the anode and cathode catalyst layers. One of the important features of the model is that it proposes a simpler modified pseudo-homogeneous/agglomerate catalyst layer model which takes the advantage of the simplicity of pseudo-homogenous modeling while taking into account the effects of the agglomerates in the catalyst layer by using experimental geometric parameters published. The computation of the general mathematical model can be accomplished in 3D, 2D and 1D with the proper assumptions. Mainly, there are two computational domains considered in this thesis. The first modeling domain is a 2D Membrane Electrode Assembly (MEA) model including the modified agglomerate/pseudo-homogeneous catalyst layer modeling with consistent treatment of water transport in the MEA while the second domain presents a 3D model with different flow filed designs: straight, stepped and tapered. COMSOL Multiphysics along with Batteries and Fuel Cell Module have been used for 2D & 3D model computations while ANSYS FLUENT PEMFC Module has been used for only 3D two-phase computation. Both models have been validated with experimental data. With 2D MEA model, the effects of temperature and water content of the membrane as well as the equivalent weight of the membrane on the performance have been addressed. 3D COMSOL simulation

  10. Towards Extrusion of Ionomers to Process Fuel Cell Membranes

    Directory of Open Access Journals (Sweden)

    Jean-Yves Sanchez

    2011-07-01

    Full Text Available While Proton Exchange Membrane Fuel Cell (PEMFC membranes are currently prepared by film casting, this paper demonstrates the feasibility of extrusion, a solvent-free alternative process. Thanks to water-soluble process-aid plasticizers, duly selected, it was possible to extrude acidic and alkaline polysulfone ionomers. Additionally, the feasibility to extrude composites was demonstrated. The impact of the plasticizers on the melt viscosity was investigated. Following the extrusion, the plasticizers were fully removed in water. The extrusion was found to impact neither on the ionomer chains, nor on the performances of the membrane. This environmentally friendly process was successfully validated for a variety of high performance ionomers.

  11. Properties, degradation and high temperature fuel cell test of different types of PBI and PBI blend membranes

    DEFF Research Database (Denmark)

    Li, Qingfeng; Rudbeck, Hans Christian; Chromik, Andreas;

    2010-01-01

    Polybenzimidazoles (PBIs) with synthetically modified structures and their blends with a partially fluorinated sulfonated aromatic polyether have been prepared and characterized for high temperature proton exchange membrane fuel cells. Significant improvement in the polymer chemical stability in ...

  12. Multiplex lithography for multilevel multiscale architectures and its application to polymer electrolyte membrane fuel cell

    Science.gov (United States)

    Cho, Hyesung; Moon Kim, Sang; Sik Kang, Yun; Kim, Junsoo; Jang, Segeun; Kim, Minhyoung; Park, Hyunchul; Won Bang, Jung; Seo, Soonmin; Suh, Kahp-Yang; Sung, Yung-Eun; Choi, Mansoo

    2015-01-01

    The production of multiscale architectures is of significant interest in materials science, and the integration of those structures could provide a breakthrough for various applications. Here we report a simple yet versatile strategy that allows for the LEGO-like integrations of microscale membranes by quantitatively controlling the oxygen inhibition effects of ultraviolet-curable materials, leading to multilevel multiscale architectures. The spatial control of oxygen concentration induces different curing contrasts in a resin allowing the selective imprinting and bonding at different sides of a membrane, which enables LEGO-like integration together with the multiscale pattern formation. Utilizing the method, the multilevel multiscale Nafion membranes are prepared and applied to polymer electrolyte membrane fuel cell. Our multiscale membrane fuel cell demonstrates significant enhancement of performance while ensuring mechanical robustness. The performance enhancement is caused by the combined effect of the decrease of membrane resistance and the increase of the electrochemical active surface area. PMID:26412619

  13. Polymer Electrolyte Membrane Fuel Cell Performance of a Sulfonated Poly(Arylene Ether Benzimidazole Copolymer Membrane

    Directory of Open Access Journals (Sweden)

    Hasan Ferdi Gerçel

    2016-01-01

    Full Text Available Disodium-3,3′-disulfonate-4,4′-dichlorodiphenylsulfone (SDCDPS and 5,5′-bis[2-(4-hydroxyphenylbenzimidazole] (HPBI monomers were synthesized. Binding these monomers via nucleophilic aromatic polycondensation reaction, a sulfonated poly(arylene ether benzimidazole copolymer was synthesized. Structures of monomers and copolymer were confirmed by proton nuclear magnetic resonance spectroscopy (1H NMR and Fourier transform infrared (FTIR spectroscopy analyses. Proton exchange membrane was prepared by dissolving copolymer in dimethylacetamide (DMAc and casting onto a glass plate. Copolymer membrane was doped with sulfuric acid to ensure proton exchange character. Single cell performance of the copolymer membrane was tested in a polymer electrolyte membrane fuel cell test station. The highest power density of the membrane was measured as 23.7 mW cm−2 at 80°C. Thermogravimetric analysis (TGA showed that as the degree of disulfonation is increased thermal stability of the copolymer is increased.

  14. Hybrid proton-conducting membranes for polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Romero, Pedro [Institut de Ciencia de Materials de Barcelona (CSIC), Campus UAB, E-08193 Bellaterra (Barcelona) (Spain)]. E-mail: pedro.gomez@icmab.es; Asensio, Juan Antonio [Institut de Ciencia de Materials de Barcelona (CSIC), Campus UAB, E-08193 Bellaterra (Barcelona) (Spain); Institut Quimic de Sarria, Universitat Ramon Llull, Via Augusta 390, E-08017 Barcelona (Spain); Borros, Salvador [Institut Quimic de Sarria, Universitat Ramon Llull, Via Augusta 390, E-08017 Barcelona (Spain)

    2005-08-30

    The synthesis and characterization of a novel hybrid organic-inorganic material formed by phosphomolybdic acid H{sub 3}PMo{sub 12}O{sub 40} (PMo{sub 12}) and poly(2,5-benzimidazole) (ABPBI) is reported. This material, composed of two proton-conducting components, can be cast in the form of membranes from methanesulfonic acid (MSA) solutions. Upon impregnation with phosphoric acid, the hybrid membranes present higher conductivity than the best ABPBI polymer membranes impregnated in the same conditions. These electrolyte membranes are stable up to 200 deg. C, and have a proton conductivity of 3 x 10{sup -2} S cm{sup -1} at 185 deg. C without humidification. These properties make them very good candidates as membranes for polymer electrolyte membrane fuel cells (PEMFC) at temperatures of 100-200 deg. C.

  15. Understanding on Interface Contribution to the Electrode Performance of Proton Exchange Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Grahl-Madsen, L.

    2016-01-01

    The commercialization of proton exchange membrane fuel cells (PEMFCs) is closer to the reality than ever before. Electrode interface development can bring a boost to the last few steps. Here, we explore electrode properties from its interface structure, especially the ionomer phase. Electrodes...

  16. Survey of sulfonated polyimide membrane as a good candidate for nafion substitution in fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Akbarian-Feizi, Leila; Mehdipour-Ataei, Shahram; Yeganeh, Hamid [Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran (Iran)

    2010-09-15

    Studies in fuel cell membranes show that modification of polyimides by introduction of aliphatic linkages in the structure of sulfonated copolyimides, synthesis of branched/crosslinked sulfonated polyimides, and semi and fully interpenetrating polymer networks of sulfonated polyimides restrain suitable potential for Nafion substitution. (author)

  17. Nanowire-based three-dimensional hierarchical core/shell heterostructured electrodes for high performance proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Madhu Sudan; Li, Ruying; Sun, Xueliang [Department of Mechanical and Materials Engineering, The University of Western Ontario, London, Ontario N6A 5B9 (Canada); Cai, Mei [General Motors Research and Development Center, Warren, MI 48090-9055 (United States)

    2008-12-01

    In order to effectively utilize expensive Pt in fuel cell electrocatalyst and improve the durability of PEM fuel cells, new catalyst supports with three-dimensional (3D) open structure are highly desirable. Here, we report the fabrication of a 3D core/shell heterostructure consisting tin nanowire core and carbon nanotube shell (SnC) grown directly onto fuel cell backing (here carbon paper) as Pt catalyst support for PEM fuel cells. Compared with the conventional Pt/C membrane electrode assembly (MEA), SnC nanowire-based MEA shows significantly higher oxygen reaction performance and better CO tolerance as well as excellent stability in PEM fuel cells. The results demonstrate that the core/shell nanowire-based composites are very promising supports in making cost effective and electrocatalysts for fuel cell applications. (author)

  18. 160 C PROTON EXCHANGE MEMBRANE (PEM) FUEL CELL SYSTEM DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    L.G. Marianowski

    2001-12-21

    The objectives of this program were: (a) to develop and demonstrate a new polymer electrolyte membrane fuel cell (PEMFC) system that operates up to 160 C temperatures and at ambient pressures for stationary power applications, and (b) to determine if the GTI-molded composite graphite bipolar separator plate could provide long term operational stability at 160 C or higher. There are many reasons that fuel cell research has been receiving much attention. Fuel cells represent environmentally friendly and efficient sources of electrical power generation that could use a variety of fuel sources. The Gas Technology Institute (GTI), formerly Institute of Gas Technology (IGT), is focused on distributed energy stationary power generation systems. Currently the preferred method for hydrogen production for stationary power systems is conversion of natural gas, which has a vast distribution system in place. However, in the conversion of natural gas into a hydrogen-rich fuel, traces of carbon monoxide are produced. Carbon monoxide present in the fuel gas will in time cumulatively poison, or passivate the active platinum catalysts used in the anodes of PEMFC's operating at temperatures of 60 to 80 C. Various fuel processors have incorporated systems to reduce the carbon monoxide to levels below 10 ppm, but these require additional catalytic section(s) with sensors and controls for effective carbon monoxide control. These CO cleanup systems must also function especially well during transient load operation where CO can spike 300% or more. One way to circumvent the carbon monoxide problem is to operate the fuel cell at a higher temperature where carbon monoxide cannot easily adsorb onto the catalyst and poison it. Commercially available polymer membranes such as Nafion{trademark} are not capable of operation at temperatures sufficiently high to prevent this. Hence this project investigated a new polymer membrane alternative to Nafion{trademark} that is capable of operation at

  19. DEVELOPMENT OF NOVEL ELECTROCATALYSTS FOR PROTON EXCHANGE MEMBRANE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Shamsuddin Ilias

    2003-04-24

    Fuel cells are electrochemical devices that convert the available chemical free energy directly into electrical energy, without going through heat exchange process. Of all different types of fuel cells, the Proton Exchange Membrane Fuel Cell (PEMFC) is one of the most promising power sources for stand-alone utility and electric vehicle applications. Platinum (Pt) Catalyst is used for both fuel and air electrodes in PEMFCs. However, carbon monoxide (CO) contamination of H{sub 2} greatly affects electro catalysts used at the anode of PEMFCs and decreases cell performance. The irreversible poisoning of the anode can occur even in CO concentrations as low as few parts per million (ppm). In this work, we have synthesized several novel elctrocatalysts (Pt/C, Pt/Ru/C, Pt/Mo/C, Pt/Ir and Pt/Ru/Mo) for PEMFCs. These catalysts have been tested for CO tolerance in the H{sub 2}/air fuel cell, using CO concentrations in the H{sub 2} fuel that varies from 10 to 100 ppm. The performance of the electrodes was evaluated by determining the cell potential against current density. The effects of catalyst composition and electrode film preparation method on the performance of PEM fuel cell were also studied. It was found that at 70 C and 3.5 atm pressure at the cathode, Pt-alloy catalyst (10 wt% Pt/Ru/C, 20 wt% Pt/Mo/C) were more CO tolerant than the 20 wt% Pt/C catalyst alone. It was also observed that spraying method was better than the brushing technique for the preparation of electrode film.

  20. Durability aspects of polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Sethuraman, Vijay Anand

    In order for the successful adoption of proton exchange membrane (PEM) fuel cell technology, it is imperative that durability is understood, quantified and improved. A number of mechanisms are known to contribute to PEMFC membrane electrode assembly (MEA) performance degradation. In this dissertation, we show, via experiments, some of the various processes that degrade the proton exchange membrane in a PEM fuel cell; and catalyst poisoning due to hydrogen sulfide (H2S) and siloxane. The effect of humidity on the chemical stability of two types of membranes, [i.e., perfluorosulfonic acid type (PFSA, NafionRTM 112) and biphenyl sulfone hydrocarbon type, (BPSH-35)] was studied by subjecting the MEAs to open-circuit voltage (OCV) decay and potential cycling tests at elevated temperatures and low inlet gas relative humidities. The BPSH-35 membranes showed poor chemical stability in ex situ Fenton tests compared to that of NafionRTM membranes. However, under fuel cell conditions, BPSH-35 MEAs outperformed NafionRTM 112 MEAs in both the OCV decay and potential cycling tests. For both membranes, (i) at a given temperature, membrane degradation was more pronounced at lower humidities and (ii) at a given relative humidity operation, increasing the cell temperature accelerated membrane degradation. Mechanical stability of these two types of membranes was also studied using relative humidity (RH) cycling. Hydrogen peroxide (H2O2) formation rates in a proton exchange membrane (PEM) fuel cell were estimated by studying the oxygen reduction reaction (ORR) on a rotating ring disc electrode (RRDE). Fuel cell conditions were replicated by depositing a film of Pt/Vulcan XC-72 catalyst onto the disk and by varying the temperature, dissolved O2 concentration and the acidity levels in HClO4. The HClO4 acidity was correlated to ionomer water activity and hence fuel cell humidity. H 2O2 formation rates showed a linear dependence on oxygen concentration and square dependence on water

  1. Aqueous liquid feed organic fuel cell using solid polymer electrolyte membrane

    Science.gov (United States)

    Surampudi, Subbarao (Inventor); Narayanan, Sekharipuram R. (Inventor); Vamos, Eugene (Inventor); Frank, Harvey A. (Inventor); Halpert, Gerald (Inventor); Olah, George A. (Inventor); Prakash, G. K. Surya (Inventor)

    1997-01-01

    A liquid organic fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.

  2. Ionic Liquids and New Proton Exchange Membranes for Fuel Cells

    Science.gov (United States)

    Belieres, Jean-Philippe

    2004-01-01

    There is currently a great surge of activity in fuel cell research as laboratories across the world seek to take advantage of the high energy capacity provided by &el cells relative to those of other portable electrochemical power systems. Much of this activity is aimed at high temperature fie1 cells, and a vital component of such &el cells must be the availability of a high temperature stable proton-permeable membrane. NASA Glenn Research Center is greatly involved in developing this technology. Other approaches to the high temperature fuel cell involve the use of single- component or almost-single-component electrolytes that provide a path for protons through the cell. A heavily researched case is the phosphoric acid fuel cell, in which the electrolyte is almost pure phosphoric acid and the cathode reaction produces water directly. The phosphoric acid fie1 cell delivers an open circuit voltage of 0.9 V falling to about 0.7 V under operating conditions at 170 C. The proton transport mechanism is mainly vehicular in character according to the viscosity/conductance relation. Here we describe some Proton Transfer Ionic Liquids (PTILs) with low vapor pressure and high temperature stability that have conductivities of unprecedented magnitude for non-aqueous systems. The first requirement of an ionic liquid is that, contrary to experience with most liquids consisting of ions, it must have a melting point that is not much above room temperature. The limit commonly suggested is 100 C. PTILs constitute an interesting class of non-corrosive proton-exchange electrolyte, which can serve well in high temperature (T = 100 - 250 C) fuel cell applications. We will present cell performance data showing that the open circuit voltage output, and the performance of a simple H2(g)Pt/PTIL/Pt/O2(g) fuel cell may be superior to those of the equivalent phosphoric acid electrolyte fuel cell both at ambient temperature and temperatures up to and above 200 C. My work at NASA Glenn Research

  3. Composite materials for polymer electrolyte membrane microbial fuel cells.

    Science.gov (United States)

    Antolini, Ermete

    2015-07-15

    Recently, the feasibility of using composite metal-carbon, metal-polymer, polymer-carbon, polymer-polymer and carbon-carbon materials in microbial fuel cells (MFCs) has been investigated. These materials have been tested as MFC anode catalyst (microorganism) supports, cathode catalysts and membranes. These hybrid materials, possessing the properties of each component, or even with a synergistic effect, would present improved characteristics with respect to the bare components. In this paper we present an overview of the use of these composite materials in microbial fuel cells. The characteristics of the composite materials as well as their effect on MFC performance were compared with those of the individual component and/or the conventionally used materials.

  4. New hybrid model of proton exchange membrane fuel cell

    Institute of Scientific and Technical Information of China (English)

    WANG Rui-min; CAO Guang-yi; ZHU Xin-jian

    2007-01-01

    Model and simulation are good tools for design optimization of fuel cell systems. This paper proposes a new hybrid model of proton exchange membrane fuel cell (PEMFC). The hybrid model includes physical component and black-box component. The physical component represents the well-known part of PEMFC, while artificial neural network (ANN) component estimates the poorly known part of PEMFC. The ANN model can compensate the performance of the physical model. This hybrid model is implemented on Matlab/Simulink software. The hybrid model shows better accuracy than that of the physical model and ANN model. Simulation results suggest that the hybrid model can be used as a suitable and accurate model for PEMFC.

  5. 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

  6. Durable, Low-cost, Improved Fuel Cell Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Chris Roger; David Mountz; Wensheng He; Tao Zhang

    2011-03-17

    The development of low cost, durable membranes and membranes electrode assemblies (MEAs) that operate under reduced relative humidity (RH) conditions remain a critical challenge for the successful introduction of fuel cells into mass markets. It was the goal of the team lead by Arkema, Inc. to address these shortages. Thus, this project addresses the following technical barriers from the fuel cells section of the Hydrogen Fuel Cells and Infrastructure Technologies Program Multi-Year Research, Development and Demonstration Plan: (A) Durability (B) Cost Arkema’s approach consisted of using blends of polyvinylidenefluoride (PVDF) and proprietary sulfonated polyelectrolytes. In the traditional approach to polyelectrolytes for proton exchange membranes (PEM), all the required properties are “packaged” in one macromolecule. The properties of interest include proton conductivity, mechanical properties, durability, and water/gas transport. This is the case, for example, for perfluorosulfonic acid-containing (PFSA) membranes. However, the cost of these materials is high, largely due to the complexity and the number of steps involved in their synthesis. In addition, they suffer other shortcomings such as mediocre mechanical properties and insufficient durability for some applications. The strength and originality of Arkema’s approach lies in the decoupling of ion conductivity from the other requirements. Kynar® PVDF provides an exceptional combination of properties that make it ideally suited for a membrane matrix (Kynar® is a registered trademark of Arkema Inc.). It exhibits outstanding chemical resistance in highly oxidative and acidic environments. In work with a prior grant, a membrane known as M41 was developed by Arkema. M41 had many of the properties needed for a high performance PEM, but had a significant deficiency in conductivity at low RH. In the first phase of this work, the processing parameters of M41 were explored as a means to increase its proton

  7. Proton Exchange Membranes for Fuel Cells Challenges and Recent Developments

    Institute of Scientific and Technical Information of China (English)

    Qingfeng Li; Jens Oluf Jensen; Pernille P. Noyé; Chao Pan; Niels J. Bjerrum

    2005-01-01

    @@ 1Introduction The current technology of proton exchange membrane fuel cells (PEMFC) is based on perfluorosulfonic acid (PFSA) membranes (e. g. Nafion(R)) as electrolyte. It operates on pure hydrogen and oxygen/air at typically 80℃ with high power density and long-term durability. For the membranes to be conductive, a minimum threshold of absorbed water molecules is about 6 to 7 mole per sulfonic site. The highest conductivity is only obtained under fully hydrated conductions, i.e. 21 - 22 mole water per sulfonic acid site. In other words, the proton conductivity is achieved by the locally liquid-like hydrophilic domain of the nanostructure.This strong dependence of conductivity on the water content in membranes limits the operational temperatureof PEMFC below 100℃.

  8. Platinum group metal-free electrocatalysts: Effects of synthesis on structure and performance in proton-exchange membrane fuel cell cathodes

    Science.gov (United States)

    Workman, Michael J.; Dzara, Michael; Ngo, Chilan; Pylypenko, Svitlana; Serov, Alexey; McKinney, Sam; Gordon, Jonathan; Atanassov, Plamen; Artyushkova, Kateryna

    2017-04-01

    Development of platinum group metal free catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) requires understanding of the interactions between surface chemistry and performance, both of which are strongly dependent on synthesis conditions. To elucidate these complex relationships, a set of Fe-N-C catalysts derived from the same set of precursor materials is fabricated by varying several key synthetic parameters under controlled conditions. The results of physicochemical characterization are presented and compared with the results of rotating disk electrode (RDE) analysis and fuel cell testing. We find that electrochemical performance is strongly correlated with three key properties related to catalyst composition: concentrations of 1) atomically dispersed Fe species, 2) species in which N is bound to Fe, and 3) surface oxides. Not only are these factors related to performance, these types of chemical species are shown to correlate with each other. This study provides evidence supporting the role of iron coordinated with nitrogen as an active species for the ORR, and offers synthetic pathways to increase the density of atomically dispersed iron species and surface oxides for optimum performance.

  9. Structure and Control Strategies of Fuel Cell Vehicle

    Institute of Scientific and Technical Information of China (English)

    宋建国; 张承宁; 孙逢春; 钟秋海

    2004-01-01

    The structure and kinds of the fuel cell vehicle (FCV) and the mathematical model of the fuel cell processor are discussed in detail. FCV includes many parts: the fuel cell thermal and water management, fuel supply, air supply and distribution, AC motor drive, main and auxiliary power management, and overall vehicle control system. So it requires different kinds of control strategies, such as the PID method, zero-pole method, optimal control method, fuzzy control and neural network control. Along with the progress of control method, the fuel cell vehicle's stability and reliability is up-and-up. Experiment results show FCV has high energy efficiency.

  10. Porous silicon membrane for micro fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Torres, N.; Duch, M.; Santander, J.; Sabate, N.; Esquivel, J.P.; Tarancon, A.; Cane, C. [Consejo Superior de Investigaciones Cientificas, Barcelona (Spain). Centro National de Microelectronica

    2009-04-15

    Significant advances have been made in the field of microsystems to offer a wide variety of applications for these devices. However, improvements in powering these devices are needed in order to obtain an autonomous power supply without increasing either the size or the cost of the devices. A promising solution involves the use of micro fuel cells instead of standard batteries, due to their easy portability, high autonomy and fast and inexpensive fuel refilling. Research in this area is based mainly on hybrid approaches consisting of microfabricated silicon parts assembled together with a Nafion thin film as a proton exchange membrane. However, higher functionality of these devices would be achieved by integrating these power sources within the microsystems to be powered. The development of specific technologies based on standard fabrication processes has to be approached and the electrode and the electrolyte will have to be developed with fabrication techniques compatible with microelectronic technologies. Porous silicon has proved to be a promising material to replace traditional Nafion-based proton exchange membranes, as this material provides a porous matrix that can be functionalized for further proton exchange behaviour. This paper presented a study that used different anodization conditions and types of silicon material to characterize the anodization process in bulk silicon. The obtained results were used to fabricate porous membranes suitable for applicability as electrolyte-frame in proton exchange membrane micro fuel cells. It was concluded that further work is needed involving pore filling with a 5 per cent Nafion solution to provide the membrane with a proton exchange capability. Moreover, a proton conductivity characterization of the membrane will be carried out as well as a complete implementation of this membrane in a final device. 10 refs., 1 tab., 6 figs.

  11. 2011 Alkaline Membrane Fuel Cell Workshop Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Pivovar, B.

    2012-02-01

    A workshop addressing the current state-of-the-art in alkaline membrane fuel cells (AMFCs) was held May 8-9, 2011, at the Crystal Gateway Marriott in Arlington, Virginia. This workshop was the second of its kind, with the first being held December 11-13, 2006, in Phoenix, Arizona. The 2011 workshop and associated workshop report were created to assess the current state of AMFC technology (taking into account recent advances), investigate the performance potential of AMFC systems across all possible power ranges and applications, and identify the key research needs for commercial competitiveness in a variety of areas.

  12. Tandem cathode for proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

    Siahrostami, Samira; Björketun, Mårten E.; Strasser, Peter

    2013-01-01

    The efficiency of proton exchange membrane fuel cells is limited mainly by the oxygen reduction reaction at the cathode. The large cathodic overpotential is caused by correlations between binding energies of reaction intermediates in the reduction of oxygen to water. This work introduces a novel...... reaction intermediate each, and they occur on different catalyst surfaces. As a result they can be optimized independently and the fundamental problem associated with the four-electron catalysis is avoided. A combination of density functional theory calculations and published experimental data is used...

  13. Ultrasonic Bonding of Membrane-Electrode-Assemblies of Fuel Cells

    Directory of Open Access Journals (Sweden)

    Dung-An Wang

    2016-05-01

    Full Text Available Ultrasonic bonding has a great potential for manufacturing of membrane electrode assemblies (MEAs of fuel cells (FCs due to its short process cycle time and low energy consumption.  Before introduction of the bonding process into the industry, a detailed and elaborate investigation of the effects of the processing parameters on the bonding quality is necessary.  We develop a finite element model of the ultrasonic bonding for MEAs of FCs.  The model can be used as a computational framework for initial evaluation of the effectiveness of ultrasonic boding for MEAs of FCs.

  14. Anion exchange membrane based on alkali doped poly(2,5-benzimidazole) for alkaline membrane fuel cell

    CSIR Research Space (South Africa)

    Luo, H

    2010-03-01

    Full Text Available Alkaline membrane fuel cell (AMFC) has been received increasing attention among the different types of fuel cells. Ammonium quaternized polymers such as poly (arylene ether sulfones) are being developed and studied as candidates of ionomeric...

  15. Direct alcohol fuel cells: toward the power densities of hydrogen-fed proton exchange membrane fuel cells.

    Science.gov (United States)

    Chen, Yanxin; Bellini, Marco; Bevilacqua, Manuela; Fornasiero, Paolo; Lavacchi, Alessandro; Miller, Hamish A; Wang, Lianqin; Vizza, Francesco

    2015-02-01

    A 2 μm thick layer of TiO2 nanotube arrays was prepared on the surface of the Ti fibers of a nonwoven web electrode. After it was doped with Pd nanoparticles (1.5 mgPd  cm(-2) ), this anode was employed in a direct alcohol fuel cell. Peak power densities of 210, 170, and 160 mW cm(-2) at 80 °C were produced if the cell was fed with 10 wt % aqueous solutions of ethanol, ethylene glycol, and glycerol, respectively, in 2 M aqueous KOH. The Pd loading of the anode was increased to 6 mg cm(-2) by combining four single electrodes to produce a maximum peak power density with ethanol at 80 °C of 335 mW cm(-2) . Such high power densities result from a combination of the open 3 D structure of the anode electrode and the high electrochemically active surface area of the Pd catalyst, which promote very fast kinetics for alcohol electro-oxidation. The peak power and current densities obtained with ethanol at 80 °C approach the output of H2 -fed proton exchange membrane fuel cells.

  16. Design of efficient methanol impermeable membranes for fuel cell applications.

    Science.gov (United States)

    Lufrano, F; Baglio, V; Di Blasi, O; Staiti, P; Antonucci, V; Aricò, A S

    2012-02-28

    In this paper, the design of efficient composite membranes based on sulfonated polysulfone and acidic silica material with characteristics and properties such as methanol barrier, high proton conductivity and suitable fuel cells performance is presented. A positive influence of nanosized acidic silica powders, used as an additive filler in the preparation of composite membranes, due to an efficient hydrophilic inter-distribution inside the membrane when compared to pure silica, is found. A series of different techniques such as XRF, FT-IR, TGA, DSC, IEC and conductivity measurements are used to highlight the properties of acidic silica material and composite membranes. The composite membrane based on acidic silica (SPSf-SiO(2)-S) shows the lowest crossover current (only 8 mA cm(-2)), which is 43% lower than that of a pure SPSf membrane and 33% lower compared to a composite membrane based on bare silica (SPSf-SiO(2)). These significant differences are attributed to the increasing diffusion path length of MeOH/H(2)O clusters in the composite membranes. The maximum DMFC performance at 30 °C is achieved with the SPSf-SiO(2)-S membrane (23 mW cm(-2)), whereas the MEAs based on SPSf-SiO(2) and pure SPSf membranes reached 21 and 16 mW cm(-2), respectively. These significant results of the composite SPSf-SiO(2)-S membrane are ascribed at a good compromise among high proton conductivity, low swelling and low methanol crossover compared to pure SPSf and (unmodified silica)-SPSf membranes. A preliminary short durability test of 100 h performed in a cell with the composite SPSf-SiO(2)-S membrane shows remarkable performance stability during chrono-voltammetric measurements (60 mA cm(-2)) at 30 °C.

  17. 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...

  18. 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

    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...... 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....... 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...

  19. Estimation of membrane hydration status for active proton exchange membrane fuel cell systems by impedance measurement

    DEFF Research Database (Denmark)

    Török, Lajos; Sahlin, Simon Lennart; Kær, Søren Knudsen

    2016-01-01

    , the membrane of which PEMFCs are made of tends to dry out when not in use. This increases the time interval required to start the system up and could lead to the destruction of the fuel cell. In this article a start-up time measurement setup is presented, which is part of a larger project, the membrane......Fuel cells are getting growing interest in industrial areas like backup systems for telecom applications or power source for electric vehicles. Although these systems are characterized by long periods of inactivity, they must be able to start at any instant in the shortest time. However...... hydration status estimator for monitoring the humidity of a fuel cell stack during standby. The fuel cell has been placed in a climatic chamber, connected to hydrogen and the start-up time has been measured with different environmental conditions. Based on the previous results and the ones presented...

  20. Water free proton conducting membranes based on poly-4-vinylpyridinebisulfate for fuel cells

    Science.gov (United States)

    Narayanan, Sekharipuram R. (Inventor); Yen, Shiao-Pin S. (Inventor)

    2007-01-01

    Disclosed are methods for forming a water-free electrolyte membrane useful in fuel cells. Also provided is a water-free electrolyte membrane comprising a quaternized amine salt including poly-4-vinylpyridinebisulfate, a poly-4-vinylpyridinebisulfate silica composite, and a combination thereof and a fuel cell comprising the membrane.

  1. Two-dimensional simulation of polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Hum, B.; Li, X. [Waterloo Univ., ON (Canada). Dept. of Mechanical Engineering

    2002-07-01

    Polymer electrolyte membrane (PEM) fuel cells have fast startup, are highly energy efficient and have high power density, rendering them very suitable for use in zero-emission vehicles and on-site power cogeneration. Before the PEM fuel cell can reach widespread commercial use, the performance has to be improved regarding the minimization of all transport resistances. This can be done by considering the electrochemical reactions in the catalyst layers along with the physical transport of reactant gas flows, product and process water, heat and the charged particles in the individual cells and stacks. This paper presents the results of a two-dimensional numerical simulation of a steady, isothermal, fully humidified PEM fuel cell which was conducted to examine what happens in the catalyst layers. The finite volume method was used together with the alternating direction implicit algorithm. It was determined that the cathode catalyst layer has more pronounced changes in potential, reaction rate and current density generation compared to the anode catalyst layer. This is because of the large cathode activation overpotential and the low diffusion coefficient of oxygen. It was demonstrated that catalyst layers, by nature, are 2 dimensional, particularly in areas of low reactant concentrations. Maximum power density is limited by the depletion of one of the reactants in the catalyst layer. Both the fuel and oxidant supply must be managed simultaneously for optimal cell performance. It was concluded that cell performance is not greatly affected by flow direction. It was noted that this analysis can also be used for more complex cell design, such as cross flow between reactant streams and practical serpentine flow channel design. 11 refs., 2 tabs., 10 figs.

  2. High aspect ratio, nanostructured, platinum based electrodes for proton exchange membrane fuel cells: Design, development and ionic conduction of the proposed structures

    Science.gov (United States)

    Paschos, Odysseas

    High aspect ratio nanostructures can provide substantial benefits when used as fuel cell electrodes since they can alleviate problems associated with conventional carbon supports. In this work the potential of incorporating high aspect ratio nanostructures as electrodes for fuel cells was studied. Moreover, a model was created that demonstrated the potential for the nanostructures to yield high performance. The creation of Pt nanorods using anodic aluminum oxide templates was investigated and experiments showed complete utilization of the electrodes surface area. However, the Pt nanorod structure was found to not be effective in terms of Pt mass utilization, since only the outer surface of the rod is utilized for catalytic activity. An alternate method was developed to coat (with Pt) high aspect ratio structures made from a cost-effective support material. Thus far, methods used to conformally coat Pt either cannot be used directly on several materials or tend not to be cost-effective. A non-vacuum method based on an Aerosol Assisted Deposition (AAD) technique was developed and optimized. Initial experiments showed feasibility of the technique to coat a large variety of substrates. Dimensions of the particles were controlled by the deposition parameters and ranged from 4 nm up to several hundreds of nm in diameter. Experiments where Pt nanoparticles were deposited on gas diffusion layer substrates, showed higher electrochemical performance compared to commercial catalyst. The need for electrolyte coating on the high aspect ratio structures was also investigated. Initial experiments were performed by splitting an MEA in half and using an intermediate Pt film. These experiments showed that ionic conduction on Pt surface is possible. Moreover these studies indicated that ionic conduction on Pt could result from hydrophilic groups that can exist on its surface. Since these groups can either be physisorbed due to presence of water or chemisorbed on the oxidized Pt

  3. Nanocomposite membranes based on polybenzimidazole and ZrO2 for high-temperature proton exchange membrane fuel cells.

    Science.gov (United States)

    Nawn, Graeme; Pace, Giuseppe; Lavina, Sandra; Vezzù, Keti; Negro, Enrico; Bertasi, Federico; Polizzi, Stefano; Di Noto, Vito

    2015-04-24

    Owing to the numerous benefits obtained when operating proton exchange membrane fuel cells at elevated temperature (>100 °C), the development of thermally stable proton exchange membranes that demonstrate conductivity under anhydrous conditions remains a significant goal for fuel cell technology. This paper presents composite membranes consisting of poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI4N) impregnated with a ZrO2 nanofiller of varying content (ranging from 0 to 22 wt %). The structure-property relationships of the acid-doped and undoped composite membranes have been studied using thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, wide-angle X-ray scattering, infrared spectroscopy, and broadband electrical spectroscopy. Results indicate that the level of nanofiller has a significant effect on the membrane properties. From 0 to 8 wt %, the acid uptake as well as the thermal and mechanical properties of the membrane increase. As the nanofiller level is increased from 8 to 22 wt % the opposite effect is observed. At 185 °C, the ionic conductivity of [PBI4N(ZrO2 )0.231 ](H3 PO4 )13 is found to be 1.04×10(-1)  S cm(-1) . This renders membranes of this type promising candidates for use in high-temperature proton exchange membrane fuel cells.

  4. Durability Issues of High Temperature Proton Exchange Membrane Fuel Cells Based on Acid Doped Polybenzimidazole Membranes

    DEFF Research Database (Denmark)

    To achieve high temperature operation of proton exchange membrane fuel cells (PEMFC), preferably under ambient pressure, phosphoric acid doped polybenzimidazole (PBI) membrane represents an effective approach, which in recent years has motivated extensive research activities with great progress....... As a critical concern, issues of long term durability of PBI based fuel cells are addressed in this talk, including oxidative degradation of the polymer, mechanical failures of the membrane, acid leaching out, corrosion of carbon support and sintering of catalysts particles. Excellent polymer durability has...... observed under continuous operation with hydrogen and air at 150-160oC, with a fuel cell performance degradation rate of 5-10 µV/h. Improvement of the membrane performance such as mechanical strength, swelling and oxidative stability has achieved by exploring the polymer chemistry, i.e. covalently...

  5. Modified SPEEK membranes for direct ethanol fuel cell

    KAUST Repository

    Maab, Husnul

    2010-07-01

    Membranes with low ethanol crossover were prepared aiming their application for direct ethanol fuel cell (DEFC). They were based on (1) sulfonated poly(ether ether ketone) (SPEEK) coated with carbon molecular sieves (CMS) and (2) on SPEEK/PI homogeneous blends. The membranes were characterized concerning their water and ethanol solution uptake, water and ethanol permeability in pervaporation experiments and their performance in DEFC tests. The ethanol permeabilities for the CMS-coated (180 nm and 400 nm thick layers) SPEEK were 8.5 and 3.1 x 10(-10) kg m s(-1) m(-2) and for the homogeneous SPEEK/PI blends membranes with 10, 20 and 30 wt.% of PI were 4.4, 1.0 and 0.4 x 10(-10) kg m s(-1) m(-2) respectively, which is 2- to 50-fold lower than that for plain SPEEK (19 x 10(-10) kg m s(-1) m(-2)). Particularly the SPEEK/PI membranes had substantially better performance than Nafion 117 membranes in DEFC tests at 60 degrees C and 90 degrees C. (C) 2010 Elsevier B.V. All rights reserved.

  6. Modified SPEEK membranes for direct ethanol fuel cell

    Science.gov (United States)

    Maab, Husnul; Nunes, Suzana Pereira

    Membranes with low ethanol crossover were prepared aiming their application for direct ethanol fuel cell (DEFC). They were based on (1) sulfonated poly(ether ether ketone) (SPEEK) coated with carbon molecular sieves (CMS) and (2) on SPEEK/PI homogeneous blends. The membranes were characterized concerning their water and ethanol solution uptake, water and ethanol permeability in pervaporation experiments and their performance in DEFC tests. The ethanol permeabilities for the CMS-coated (180 nm and 400 nm thick layers) SPEEK were 8.5 and 3.1 × 10 -10 kg m s -1 m -2 and for the homogeneous SPEEK/PI blends membranes with 10, 20 and 30 wt.% of PI were 4.4, 1.0 and 0.4 × 10 -10 kg m s -1 m -2 respectively, which is 2- to 50-fold lower than that for plain SPEEK (19 × 10 -10 kg m s -1 m -2). Particularly the SPEEK/PI membranes had substantially better performance than Nafion 117 ® membranes in DEFC tests at 60 °C and 90 °C.

  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. Nanocomposite Membranes based on Perlfuorosulfonic Acid/Ceramic for Proton Exchange Membrane Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    LI Qiong; WANG Guangjin; YE Hong; YAN Shilin

    2015-01-01

    Perlfuorosulfonic acid/ceramic nanocomposite membranes were investigated as electrolytes for polymer electrolyte membrane fuel cell applications under low relative humidity. Different nanosized ceramics (SiO2, ZrO2, TiO2) with diameters in the range of 2-6 nm were synthesized in situ in Nafion solution through a sol-gel process and the formed nanosized ceramics were well-dispersed in the solution. The nanocomposite membranes were formed through a casting process. The nanocomposite membrane showes enhanced water retention ability and improved proton conductivity compared to those of pure Naifon membrane. The mechanical strength of the formed nanocomposite membranes is slightly less than that of pure Naifon membrane. The experimental results demonstrate that the polymer ceramic nanocompsite membranes are potential electrolyte for fuel cells operating at elevated temperature.

  9. Phosphoric acid doped imidazolium polysulfone membranes for high temperature proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

    Yang, Jingshuai; Li, Qingfeng; Jensen, Jens Oluf

    2012-01-01

    A novel acid–base polymer membrane is prepared by doping of imidazolium polysulfone with phosphoric acid for high temperature proton exchange membrane fuel cells. Polysulfone is first chloromethylated, followed by functionalization of the chloromethylated polysulfone with alkyl imidazoles i.e. me...

  10. Estimation of membrane hydration status for standby proton exchange membrane fuel cell systems by impedance measurement

    DEFF Research Database (Denmark)

    Bidoggia, Benoit; Rugholt, Mark; Nielsen, Morten Busk

    2014-01-01

    Fuel cells are getting growing interest in both backup systems and electric vehicles. Although these systems are characterized by long periods of inactivity, they must be able to start at any instant in the shortest time. However, the membrane of which PEMFCs are made tends to dry out when...... not in use. This increases the time required to start the system and could lead to the destruction of the fuel cell. In this article an impedance measurement circuit is presented, which is part of a humidity status estimator for monitoring the humidity status of a fuel cell stack during standby....... The impedance measurement circuit has been connected to a fuel cell stack and the operation of estimating the relative humidity has been demonstrated....

  11. Segmented polymer electrolyte membrane fuel cells - A review

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Luis C.; Brandao, Lucia; Mendes, Adelio [LEPAE, Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Roberto Frias, 4200-465 Porto (Portugal); Sousa, Jose M. [LEPAE, Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Roberto Frias, 4200-465 Porto (Portugal); Chemistry Department, University of Tras-os-Montes e Alto Douro, Apartado 202, 5001-911 Vila-Real Codex (Portugal)

    2011-01-15

    A complex interaction of many design, assembling and operating parameters as well as the properties of the materials used in the construction of polymer electrolyte membrane fuel cells (PEMFC) result in an uneven electrochemical performance over the MEA active area. For more than one decade, segmented PEMFC (SFC) have been used to study the factors responsible for that uneven performance. This paper reviews relevant literature related to SFC published since 1998 focusing on the three most important SFC design techniques: (1) printed circuit board, (2) resistors network and (3) Hall effect sensors. First, the three techniques are described and fundamental considerations for its design, construction and electrochemical characterization are provided. After that, the effect of most important parameters on the current density distribution is highlighted. Finally, representative results combining current density distribution measurements with other analytical techniques for distributed analysis are presented. (author)

  12. Analysis performance of proton exchange membrane fuel cell (PEMFC)

    Science.gov (United States)

    Mubin, A. N. A.; Bahrom, M. H.; Azri, M.; Ibrahim, Z.; Rahim, N. A.; Raihan, S. R. S.

    2017-06-01

    Recently, the proton exchange membrane fuel cell (PEMFC) has gained much attention to the technology of renewable energy due to its mechanically ideal and zero emission power source. PEMFC performance reflects from the surroundings such as temperature and pressure. This paper presents an analysis of the performance of the PEMFC by developing the mathematical thermodynamic modelling using Matlab/Simulink. Apart from that, the differential equation of the thermodynamic model of the PEMFC is used to explain the contribution of heat to the performance of the output voltage of the PEMFC. On the other hand, the partial pressure equation of the hydrogen is included in the PEMFC mathematical modeling to study the PEMFC voltage behaviour related to the input variable input hydrogen pressure. The efficiency of the model is 33.8% which calculated by applying the energy conversion device equations on the thermal efficiency. PEMFC’s voltage output performance is increased by increasing the hydrogen input pressure and temperature.

  13. Fault tolerance control for proton exchange membrane fuel cell systems

    Science.gov (United States)

    Wu, Xiaojuan; Zhou, Boyang

    2016-08-01

    Fault diagnosis and controller design are two important aspects to improve proton exchange membrane fuel cell (PEMFC) system durability. However, the two tasks are often separately performed. For example, many pressure and voltage controllers have been successfully built. However, these controllers are designed based on the normal operation of PEMFC. When PEMFC faces problems such as flooding or membrane drying, a controller with a specific design must be used. This paper proposes a unique scheme that simultaneously performs fault diagnosis and tolerance control for the PEMFC system. The proposed control strategy consists of a fault diagnosis, a reconfiguration mechanism and adjustable controllers. Using a back-propagation neural network, a model-based fault detection method is employed to detect the PEMFC current fault type (flooding, membrane drying or normal). According to the diagnosis results, the reconfiguration mechanism determines which backup controllers to be selected. Three nonlinear controllers based on feedback linearization approaches are respectively built to adjust the voltage and pressure difference in the case of normal, membrane drying and flooding conditions. The simulation results illustrate that the proposed fault tolerance control strategy can track the voltage and keep the pressure difference at desired levels in faulty conditions.

  14. 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...

  15. Nafion®/H-ZSM-5 composite membranes with superior performance for direct methanol fuel cells

    NARCIS (Netherlands)

    Yildirim, Mustafa Hakan; Curos, Anna Roca; Motuzas, Julius; Julbe, Anne; Stamatialis, Dimitrios; Wessling, Matthias

    2009-01-01

    Solution cast composite direct methanol fuel cell membranes (DEZ) based on DE2020 Nafion® dispersion and in-house prepared H-ZSM-5 zeolites with different Si/Al ratios were prepared and thoroughly characterized for direct methanol fuel cell (DMFC) applications. All composite membranes have indeed l

  16. 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

    is an order of magnitude higher than that of the common polybenzimidazole membranes with similar acid contents. A preliminary H2/air fuel cell test at 180°C showed a peak power density of 350mWcm-2 of the fuel cell equipped with the phosphoric acid doped PIBI-1/1 membrane with a 300wt% acid uptake...

  17. High Performance Fuel Cell and Electrolyzer Membrane Electrode Assemblies (MEAs) for Space Energy Storage Systems

    Science.gov (United States)

    Valdez, Thomas I.; Billings, Keith J.; Kisor, Adam; Bennett, William R.; Jakupca, Ian J.; Burke, Kenneth; Hoberecht, Mark A.

    2012-01-01

    Regenerative fuel cells provide a pathway to energy storage system development that are game changers for NASA missions. The fuel cell/ electrolysis MEA performance requirements 0.92 V/ 1.44 V at 200 mA/cm2 can be met. Fuel Cell MEAs have been incorporated into advanced NFT stacks. Electrolyzer stack development in progress. Fuel Cell MEA performance is a strong function of membrane selection, membrane selection will be driven by durability requirements. Electrolyzer MEA performance is catalysts driven, catalyst selection will be driven by durability requirements. Round Trip Efficiency, based on a cell performance, is approximately 65%.

  18. 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...

  19. Polyvinyl alcohol (PVA) and sulfonated polyetheretherketone (SPEEK) anion exchange membrane for fuel cell

    CSIR Research Space (South Africa)

    Luo, H

    2010-08-31

    Full Text Available problems for PEFC (using proton exchange membrane) concerning the increasing cost of platinum catalysts and decreasing amount of platinum resources2. Alkaline membrane fuel cells (AMFC) have recently been receiving a lot of attention among the different...

  20. High Proton Conducting SPEEK/SiO2/PWA Composite Membranes for Direct Methanol Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gaowen; JIANG Jiuxin; LIU Jianing

    2011-01-01

    Sulfonated polyether ether ketone (SPEEK) based composite membranes for direct methanol fuel cell (DMFC) application were prepared by sol-gel reaction of tetraethoxysilane (TEOS) in the SPEEK matrix and the incorporation of phosphotungstic acid (PWA). The conductivity of the developed membranes was determined by impedance spectroscopy and the methanol permeability through the membranes was obtained from diffuseness experiments. The SEM images show that the addition of SiO2 and the covalent cross-linking structure lead to fine PWA particles and more uniformly dispersion. The swelling of composite membranes remains in the range of 5%-8% at 30-90 ℃ and the effusion of PWA reduces significantly. The composite membranes show a good balance in higher proton conductivity and lower methanol permeation. The cell with composite membrane has higher open circuit voltage(0.728 V) and higher peak power density(45 mW/cm2) than that with Nation 117.

  1. Computational fluid dynamics modelling of a polymer electrolyte membrane fuel cell under transient automotive operations

    OpenAIRE

    Choopanya, Pattarapong

    2016-01-01

    A polymer electrolyte membrane (PEM) fuel cell is probably the most promising technology that will replace conventional internal combustion engines in the near future. As a primary power source for an automobile, the transient performance of a PEM fuel cell is of prime importance. In this thesis, a comprehensive, three-dimensional, two-phase, multi-species computational fuel cell dynamics model is developed in order to investigate the effect of flow-field design on the magnitude of current ov...

  2. Estimation of membrane hydration status for standby proton exchange membrane fuel cell systems by impedance measurement

    DEFF Research Database (Denmark)

    Bidoggia, Benoit; Rugholt, Mark; Nielsen, Morten Busk;

    2014-01-01

    Fuel cells are getting growing interest in both backup systems and electric vehicles. Although these systems are characterized by long periods of inactivity, they must be able to start at any instant in the shortest time. However, the membrane of which PEMFCs are made tends to dry out when...

  3. Heat sources in proton exchange membrane (PEM) fuel cells

    Science.gov (United States)

    Ramousse, Julien; Lottin, Olivier; Didierjean, Sophie; Maillet, Denis

    In order to model accurately heat transfer in PEM fuel cell, a particular attention had to be paid to the assessment of heat sources in the cell. Although the total amount of heat released is easily computed from its voltage, local heat sources quantification and localization are not simple. This paper is thus a discussion about heat sources/sinks distribution in a single cell, for which many bold assumptions are encountered in the literature. The heat sources or sinks under consideration are: (1) half-reactions entropy, (2) electrochemical activation, (3) water sorption/desorption at the GDL/membrane interfaces, (4) Joule effect in the membrane and (5) water phase change in the GDL. A detailed thermodynamic study leads to the conclusion that the anodic half-reaction is exothermic (Δ Sr ev a = - 226 J mo l-1 K-1) , instead of being athermic as supposed in most of the thermal studies. As a consequence, the cathodic half-reaction is endothermic (Δ Sr ev c = + 62.8 J mo l-1 K-1) , which results in a heat sink at the cathode side, proportional to the current. In the same way, depending on the water flux through the membrane, sorption can create a large heat sink at one electrode and an equivalent heat source at the other. Water phase change in the GDL - condensation/evaporation - results in heat sources/sinks that should also be taken into account. All these issues are addressed in order to properly set the basis of heat transfer modeling in the cell.

  4. Inorganic-organic Composite Membranes with Novel Microstructure for High Temperature Proton Exchange Membrane Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    Zhigang Ma; Jiandong Gao; Jing Guo; Zhenghua Deng; Jishuan Suo

    2007-01-01

    Nowadays,more and more fossil fuels are consumed and air pollurion has become a threat to the survival of people.Therefore,we need some other power sources to provide energy without damaging the environment.Proton exchange membrane fuel cells(PEMFCs)have received wide attention due to their advantages Such as high energy density and zero emission[1].Particularly, direct methanol fuel cells (DMFCs)were considered as the most suitable energy sources for electric vehicles(EVs)and portable electronics.

  5. Novel Blend Membranes Based on Acid-Base Interactions for Fuel Cells

    Directory of Open Access Journals (Sweden)

    Yongzhu Fu

    2012-10-01

    Full Text Available Fuel cells hold great promise for wide applications in portable, residential, and large-scale power supplies. For low temperature fuel cells, such as the proton exchange membrane fuel cells (PEMFCs and direct methanol fuel cells (DMFCs, proton-exchange membranes (PEMs are a key component determining the fuel cells performance. PEMs with high proton conductivity under anhydrous conditions can allow PEMFCs to be operated above 100 °C, enabling use of hydrogen fuels with high-CO contents and improving the electrocatalytic activity. PEMs with high proton conductivity and low methanol crossover are critical for lowering catalyst loadings at the cathode and improving the performance and long-term stability of DMFCs. This review provides a summary of a number of novel acid-base blend membranes consisting of an acidic polymer and a basic compound containing N-heterocycle groups, which are promising for PEMFCs and DMFCs.

  6. Manifold seal structure for fuel cell stack

    Science.gov (United States)

    Collins, William P.

    1988-01-01

    The seal between the sides of a fuel cell stack and the gas manifolds is improved by adding a mechanical interlock between the adhesive sealing strip and the abutting surface of the manifolds. The adhesive is a material which can flow to some extent when under compression, and the mechanical interlock is formed providing small openings in the portion of the manifold which abuts the adhesive strip. When the manifolds are pressed against the adhesive strips, the latter will flow into and through the manifold openings to form buttons or ribs which mechanically interlock with the manifolds. These buttons or ribs increase the bond between the manifolds and adhesive, which previously relied solely on the adhesive nature of the adhesive.

  7. Catalyst Degradation in High Temperature Proton Exchange Membrane Fuel Cells Based on Acid Doped Polybenzimidazole Membranes

    DEFF Research Database (Denmark)

    Cleemann, Lars Nilausen; Buazar, F.; Li, Qingfeng;

    2013-01-01

    Degradation of carbon supported platinum catalysts is a major failure mode for the long term durability of high temperature proton exchange membrane fuel cells based on phosphoric acid doped polybenzimidazole membranes. With Vulcan carbon black as a reference, thermally treated carbon black...... and multi‐walled carbon nanotubes were used as supports for electrode catalysts and evaluated in accelerated durability tests under potential cycling at 150 °C. Measurements of open circuit voltage, area specific resistance and hydrogen permeation through the membrane were carried out, indicating little...... contribution of the membrane degradation to the performance losses during the potential cycling tests. As the major mechanism of the fuel cell performance degradation, the electrochemical active area of the cathodic catalysts showed a steady decrease in the cyclic voltammetric measurements, which was also...

  8. Low stoichiometry operation of a proton exchange membrane fuel cell employing the interdigitated flow field

    DEFF Research Database (Denmark)

    Berning, Torsten; Kær, Søren Knudsen

    2012-01-01

    A multiphase fuel cell model based on computational fluid dynamics is used to investigate the possibility of operating a proton exchange membrane fuel cell at low stoichiometric flow ratios (ξ < 1.5) employing the interdigitated flow field design and using completely dry inlet gases. A case study...

  9. Magnetic resonance imaging of water content across the Nafion membrane in an operational PEM fuel cell

    Science.gov (United States)

    Zhang, Ziheng; Martin, Jonathan; Wu, Jinfeng; Wang, Haijiang; Promislow, Keith; Balcom, Bruce J.

    2008-08-01

    Water management is critical to optimize the operation of polymer electrolyte membrane fuel cells. At present, numerical models are employed to guide water management in such fuel cells. Accurate measurements of water content variation in polymer electrolyte membrane fuel cells are required to validate these models and to optimize fuel cell behavior. We report a direct water content measurement across the Nafion membrane in an operational polymer electrolyte membrane fuel cell, employing double half k-space spin echo single point imaging techniques. The MRI measurements with T2 mapping were undertaken with a parallel plate resonator to avoid the effects of RF screening. The parallel plate resonator employs the electrodes inherent to the fuel cell to create a resonant circuit at RF frequencies for MR excitation and detection, while still operating as a conventional fuel cell at DC. Three stages of fuel cell operation were investigated: activation, operation and dehydration. Each profile was acquired in 6 min, with 6 μm nominal resolution and a SNR of better than 15.

  10. Dynamic Model of the High Temperature Proton Exchange Membrane Fuel Cell Stack Temperature

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2009-01-01

    consists of a prototype cathode air cooled 30 cell HTPEM fuel cell stack developed at the Institute of Energy Technology at Aalborg University. This fuel cell stack uses PEMEAS Celtec P-1000 membranes and runs on pure hydrogen in a dead-end anode configuration with a purge valve. The cooling of the stack...

  11. Simulation of nanostructured electrodes for polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Rao, Sanjeev M.; Xing, Yangchuan

    Aligned carbon nanotubes (CNTs) with Pt uniformly deposited on them are being considered in fabricating the catalyst layer of polymer electrolyte membrane (PEM) fuel cell electrodes. When coated with a proton conducting polymer (e.g., Nafion) on the Pt/CNTs, each Pt/CNT acts as a nanoelectrode and a collection of such nanoelectrodes constitutes the proposed nanostructured electrodes. Computer modeling was performed for the cathode side, in which both multicomponent and Knudsen diffusion were taken into account. The effect of the nanoelectrode lengths was also studied with catalyst layer thicknesses of 2, 4, 6, and 10 μm. It was observed that shorter lengths produce better electrode performance due to lower diffusion barriers and better catalyst utilization. The effect of spacing between the nanoelectrodes was studied. Simulation results showed the need to have sufficiently large gas pores, i.e., large spacing, for good oxygen transport. However, this is at the cost of obtaining large electrode currents due to reduction of the number of nanoelectrodes per unit geometrical area of the nanostructured electrode. An optimization of the nanostructured electrodes was obtained when the spacing was at about 400 nm that produced the best limiting current density.

  12. Spatial proton exchange membrane fuel cell performance under bromomethane poisoning

    Science.gov (United States)

    Reshetenko, Tatyana V.; Artyushkova, Kateryna; St-Pierre, Jean

    2017-02-01

    The poisoning effects of 5 ppm CH3Br in the air on the spatial performance of a proton exchange membrane fuel cell (PEMFC) were studied using a segmented cell system. The presence of CH3Br caused performance loss from 0.650 to 0.335 V at 1 A cm-2 accompanied by local current density redistribution. The observed behavior was explained by possible bromomethane hydrolysis with the formation of Br-. Bromide and bromomethane negatively affected the oxygen reduction efficiency over a wide range of potentials because of their adsorption on Pt, which was confirmed by XPS. Moreover, the PEMFC exposure to CH3Br led to a decrease in the anode and cathode electrochemical surface area (∼52-57%) due to the growth of Pt particles through agglomeration and Ostwald ripening. The PEMFC did not restore its performance after stopping bromomethane introduction to the air stream. However, the H2/N2 purge of the anode/cathode and CV scans almost completely recovered the cell performance. The observed final loss of ∼50 mV was due to an increased activation overpotential. PEMFC exposure to CH3Br should be limited to concentrations much less than 5 ppm due to serious performance loss and lack of self-recovery.

  13. Proton exchange membrane fuel cells for electrical power generation on-board commercial airplanes.

    Energy Technology Data Exchange (ETDEWEB)

    Curgus, Dita Brigitte; Munoz-Ramos, Karina (Sandia National Laboratories, Albuquerque, NM); Pratt, Joseph William; Akhil, Abbas Ali (Sandia National Laboratories, Albuquerque, NM); Klebanoff, Leonard E.; Schenkman, Benjamin L. (Sandia National Laboratories, Albuquerque, NM)

    2011-05-01

    Deployed on a commercial airplane, proton exchange membrane fuel cells may offer emissions reductions, thermal efficiency gains, and enable locating the power near the point of use. This work seeks to understand whether on-board fuel cell systems are technically feasible, and, if so, if they offer a performance advantage for the airplane as a whole. Through hardware analysis and thermodynamic and electrical simulation, we found that while adding a fuel cell system using today's technology for the PEM fuel cell and hydrogen storage is technically feasible, it will not likely give the airplane a performance benefit. However, when we re-did the analysis using DOE-target technology for the PEM fuel cell and hydrogen storage, we found that the fuel cell system would provide a performance benefit to the airplane (i.e., it can save the airplane some fuel), depending on the way it is configured.

  14. Proton Exchange Membrane Fuel Cells for Electrical Power Generation On-Board Commercial Airplanes

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, Joesph W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Klebanoff, Leonard E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Munoz-Ramos, Karina [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Akhil, Abbas A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Curgus, Dita B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schenkman, Benjamin L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2011-05-01

    Deployed on a commercial airplane, proton exchange membrane fuel cells may offer emissions reductions, thermal efficiency gains, and enable locating the power near the point of use. This work seeks to understand whether on-board fuel cell systems are technically feasible, and, if so, if they offer a performance advantage for the airplane as a whole. Through hardware analysis and thermodynamic and electrical simulation, we found that while adding a fuel cell system using today’s technology for the PEM fuel cell and hydrogen storage is technically feasible, it will not likely give the airplane a performance benefit. However, when we re-did the analysis using DOE-target technology for the PEM fuel cell and hydrogen storage, we found that the fuel cell system would provide a performance benefit to the airplane (i.e., it can save the airplane some fuel), depending on the way it is configured.

  15. Proton exchange membrane fuel cell system diagnosis based on the signed directed graph method

    Science.gov (United States)

    Hua, Jianfeng; Lu, Languang; Ouyang, Minggao; Li, Jianqiu; Xu, Liangfei

    The fuel-cell powered bus is becoming the favored choice for electric vehicles because of its extended driving range, zero emissions, and high energy conversion efficiency when compared with battery-operated electric vehicles. In China, a demonstration program for the fuel cell bus fleet operated at the Beijing Olympics in 2008 and the Shanghai Expo in 2010. It is necessary to develop comprehensive proton exchange membrane fuel cell (PEMFC) diagnostic tools to increase the reliability of these systems. It is especially critical for fuel-cell city buses serving large numbers of passengers using public transportation. This paper presents a diagnostic analysis and implementation study based on the signed directed graph (SDG) method for the fuel-cell system. This diagnostic system was successfully implemented in the fuel-cell bus fleet at the Shanghai Expo in 2010.

  16. 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.

  17. Development of composite membranes of PVA-TEOS doped KOH for alkaline membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Haryadi,, E-mail: haryadi@polban.ac.id; Sugianto, D.; Ristopan, E. [Department of Chemical Engineering, Politeknik Negeri Bandung Jl. Gegerkalong Hilir, Ds. Ciwaruga, Bandung West Java (Indonesia)

    2015-12-29

    Anion exchange membranes (AEMs) play an important role in separating fuel and oxygen (or air) in the Alkaline Membrane Fuel Cells. Preparation of hybrid organic inorganic materials of Polyvinylalcohol (PVA) - Tetraethylorthosilicate (TEOS) composite membrane doped KOH for direct alcohol alkaline fuel cell application has been investigated. The sol-gel method has been used to prepare the composite membrane of PVA-TEOS through crosslinking step and catalyzed by concentrated of hydrochloric acid. The gel solution was cast on the membrane plastic plate to obtain membrane sheets. The dry membranes were then doped by immersing in various concentrations of KOH solutions for about 4 hours. Investigations of the cross-linking process and the presence of hydroxyl group were conducted by FTIR as shown for frequency at about 1600 cm{sup −1} and 3300 cm{sup −1} respectively. The degree of swelling in ethanol decreased as the KOH concentration for membrane soaking process increased. The ion exchange capacity (IEC) of the membrane was 0.25meq/g. This composite membranes display significant ionic conductivity of 3.23 x 10{sup −2} S/cm in deionized water at room temperature. In addition, the morphology observation by scanning electron microscope (SEM) of the membrane indicates that soaking process of membrane in KOH increased thermal resistant.

  18. Engineering particle morphology and assembly for proton conducting fuel cell membrane applications

    Science.gov (United States)

    Liu, Dongxia

    The development of high performance ion conducting membranes is crucial to the commercialization of polymer electrolyte membrane fuel cells (PEMFCs) and solid oxide fuel cells (SOFCs). This thesis work addresses some of the issues for improving the performance of ion conducting membranes in PEMFCs and SOFCs through engineering membrane microstructures. Electric-field directed particle assembly shows promise as a route to control the structure of polymer composite membranes in PEMFCs. The application of electric fields results in the aggregation of proton conducting particles into particle chains spanning the thickness of composite membranes. The field-induced structure provides improved proton conductivity, selectivity for protons over methanol, and mechanical stability compared to membranes processed without electric field. Hydrothermal deposition is developed as a route to grow electrolyte crystals into membranes (material is hydroxyapatite) with aligned proton conductive pathways that significantly enhance proton transport by eliminating grain boundary resistance. By varying deposition parameters such as reactant concentration, reaction time, or adding crystal growth modifiers, dense hydroxyapatite electrolyte membranes with a range of thickness are produced. The microstructurally engineered hydroxyapatite membranes are promising electrolyte candidates for intermediate temperature fuel cells. The microstructural engineering of ceramics by hydrothermal deposition can potentially be applied to create other ion conducting materials with optimized transport properties. To understand how to control the crystal growth habit by adding growth modifiers, growth of unusual calcite rods was investigated in a microemulsion-based synthesis prior to the investigation of hydrothermal deposition of hydroxyapatite membranes. The microemulsions act as crystal growth modifier to mediate crystal nucleation and subsequent growth. The small microemulsion droplets confine nucleation

  19. BLEND MEMBRANES FOR DIRECT METHANOL AND PROTON EXCHANGE MEMBRANE FUEL CELLS

    Institute of Scientific and Technical Information of China (English)

    Perurnal Bhavani; Dharmalingam Sangeetha

    2012-01-01

    Sulphonated polystyrene ethylene butylene polystyrene (SPSEBS) prepared with 35% sulphonation was found to be highly elastic and enlarged up to 300%-400% of its initial length.It absorbed over 110% of water by weight.A major drawback of this membrane is its poor mechanical properties which are not adequate for use as polymer electrolytes in fuel cells.To overcome this,SPSEBS was blended with poly(vinylidene fluoride) (PVDF),a hydrophobic polymer.The blend membranes showed better mechanical properties than the base polymer.The effect of PVDF content on water uptake,ion exchange capacity and proton conductivity of the blend membranes was investigated.This paper presents the results of recent studies applied to develop an optimized in-house membrane electrode assembly (MEA) preparation technique combining catalyst ink spraying and assembly hot pressing.Easy steps were chosen in this preparation technique in order to simplify the method,aiming at cost reduction.The open circuit voltage for the cell with SPSEBS is 0.980 V which is higher compared to that of the cell with Nafion 117 (0.790 V).From this study,it is concluded that a polymer electrolyte membrane suitable for proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC) application can be obtained by blending SPSEBS and PVDF in appropriate proportions.The methanol permeability and selectivity showed a strong influence on DMFC performance.

  20. A boron phosphate-phosphoric acid composite membrane for medium temperature proton exchange membrane fuel cells

    Science.gov (United States)

    Mamlouk, M.; Scott, K.

    2015-07-01

    A composite membrane based on a non-stoichiometric composition of BPO4 with excess of PO4 (BPOx) was synthesised and characterised for medium temperature fuel cell use (120-180 °C). The electrolyte was characterised by FTIR, SS-NMR, TGA and XRD and showed that the B-O is tetrahedral, in agreement with reports in the literature that boron phosphorus oxide compounds at B:P < 1 are exclusively built of borate and phosphate tetrahedra. Platinum micro electrodes were used to study the electrolyte compatibility and stability towards oxygen reduction at 150 °C and to obtain kinetic and mass transport parameters. The conductivities of the pure BPOx membrane electrolyte and a Polybenzimidazole (PBI)-4BPOx composite membrane were 7.9 × 10-2 S cm-1 and 4.5 × 10-2 S cm-1 respectively at 150 °C, 5%RH. Fuel cell tests showed a significant enhancement in performance of BPOx over that of typical 5.6H3PO4-PBI membrane electrolyte. The enhancement is due to the improved ionic conductivity (3×), a higher exchange current density of the oxygen reduction (30×) and a lower membrane gas permeability (10×). Fuel cell current densities at 0.6 V were 706 and 425 mA cm-2 for BPOx and 5.6H3PO4-PBI, respectively, at 150 °C with O2 (atm).

  1. Importance of Electrode Hot-Pressing Conditions for the Catalyst Performance of Proton Exchange Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Dhiman, Rajnish; Larsen, Mikkel Juul;

    2015-01-01

    The catalyst performance in a proton exchange membrane fuel cell (PEMFC) depends on not only the choice of materials, but also on the electrode structure and in particular on the interface between the components. In this work, we demonstrate that the hot-pressing conditions used during electrode...

  2. Methods for using novel cathode and electrolyte materials for solid oxide fuel cells and ion transport membranes

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, Allan J.; Wang, Shuangyan; Kim, Gun Tae

    2016-01-12

    Methods using novel cathode, electrolyte and oxygen separation materials operating at intermediate temperatures for use in solid oxide fuel cells and ion transport membranes include oxides with perovskite related structures and an ordered arrangement of A site cations. The materials have significantly faster oxygen kinetics than in corresponding disordered perovskites.

  3. New composite membranes based on modified Nafion or Flemion for PEM fuel cell application

    Science.gov (United States)

    Tian, Huimin

    Nafion and Flemion during the procedure of casting composite membrane and there was the interaction between the sulphonic acid group and STA. X-ray photoelectron spectroscopy shows the existence of W-S and W-C bonds in composite membrane. This can be used to explain the previous experimental observation that the composite membrane with STA has higher conductivity and water uptake than the composite membrane without STA. The above studies allowed us to conclude that the improvements in ionic conductivity and water uptake are due to the change of the chemical composition of the composite membranes by the addition of silicotungstic acid. The current-potential polarization characterization of composite Nafion/STA and Flemion/STA membranes was measured using H2/O2 single polymer electrolyte membrane (PEM) fuel cell system. The performance based on composite Nafion/STA and Flemion/STA membranes is always better than that based on cast Nafion or cast Flemion without STA membranes. The improvement in the fuel cell characteristics for the composite Nafion/STA and Flemion/STAmembrane is due to a combined effect of the polymer and STA. The existence of STA improves the fuel cell performance and make this operation feasible under high temperature.

  4. Diffusion-driven proton exchange membrane fuel cell for converting fermenting biomass to electricity.

    Science.gov (United States)

    Malati, P; Mehrotra, P; Minoofar, P; Mackie, D M; Sumner, J J; Ganguli, R

    2015-10-01

    A membrane-integrated proton exchange membrane fuel cell that enables in situ fermentation of sugar to ethanol, diffusion-driven separation of ethanol, and its catalytic oxidation in a single continuous process is reported. The fuel cell consists of a fermentation chamber coupled to a direct ethanol fuel cell. The anode and fermentation chambers are separated by a reverse osmosis (RO) membrane. Ethanol generated from fermented biomass in the fermentation chamber diffuses through the RO membrane into a glucose solution contained in the DEFC anode chamber. The glucose solution is osmotically neutral to the biomass solution in the fermentation chamber preventing the anode chamber from drying out. The fuel cell sustains >1.3 mW cm(-2) at 47°C with high discharge capacity. No separate purification or dilution is necessary, resulting in an efficient and portable system for direct conversion of fermenting biomass to electricity.

  5. Cross-lined PEEK proton exchange membranes for fuel cell - Conference Poster

    CSIR Research Space (South Africa)

    Luo, H

    2009-07-01

    Full Text Available conductive, mechanically and chemically stable. They showed reduced water uptake and reduced methanol crossover. The membrane was applied in a direct methanol fuel cell (DMFC) and a considerable performance improvement was found as compared to commercial...

  6. Technological aspects in synthesis and characterization of proton conducting polyetheretherketone (PEEK) membranes for fuel cell applications.

    CSIR Research Space (South Africa)

    Vaivars, G

    2009-08-01

    Full Text Available in various industrial fields: medicine, analytical chemistry, electro- and diffusion dialysis, sensors, both separator and solid polymer electrolyte in electrolysis, batteries, fuel cells, etc [1]. The research on ion-exchange membranes has grown...

  7. Proton exchange membrane fuel cells modeling based on artificial neural networks

    Institute of Scientific and Technical Information of China (English)

    Yudong Tian; Xinjian Zhu; Guangyi Cao

    2005-01-01

    To understand the complexity of the mathematical models of a proton exchange membrane fuel cell (PEMFC) and their shortage of practical PEMFC control, the PEMFC complex mechanism and the existing PEMFC models are analyzed, and artificial neural networks based PEMFC modeling is advanced. The structure, algorithm, training and simulation of PEMFC modeling based on improved BP networks are given out in detail. The computer simulation and conducted experiment verify that this model is fast and accurate, and can be used as a suitable operational model for PEMFC real-time control.

  8. Recent Development of Pd-Based Electrocatalysts for Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Hui Meng

    2015-07-01

    Full Text Available This review selectively summarizes the latest developments in the Pd-based cataysts for low temperature proton exchange membrane fuel cells, especially in the application of formic acid oxidation, alcohol oxidation and oxygen reduction reaction. The advantages and shortcomings of the Pd-based catalysts for electrocatalysis are analyzed. The influence of the structure and morphology of the Pd materials on the performance of the Pd-based catalysts were described. Finally, the perspectives of future trends on Pd-based catalysts for different applications were considered.

  9. An analytical model and parametric study of electrical contact resistance in proton exchange membrane fuel cells

    Science.gov (United States)

    Wu, Zhiliang; Wang, Shuxin; Zhang, Lianhong; Hu, S. Jack

    This paper presents an analytical model of the electrical contact resistance between the carbon paper gas diffusion layers (GDLs) and the graphite bipolar plates (BPPs) in a proton exchange membrane (PEM) fuel cell. The model is developed based on the classical statistical contact theory for a PEM fuel cell, using the same probability distributions of the GDL structure and BPP surface profile as previously described in Wu et al. [Z. Wu, Y. Zhou, G. Lin, S. Wang, S.J. Hu, J. Power Sources 182 (2008) 265-269] and Zhou et al. [Y. Zhou, G. Lin, A.J. Shih, S.J. Hu, J. Power Sources 163 (2007) 777-783]. Results show that estimates of the contact resistance compare favorably with experimental data by Zhou et al. [Y. Zhou, G. Lin, A.J. Shih, S.J. Hu, J. Power Sources 163 (2007) 777-783]. Factors affecting the contact behavior are systematically studied using the analytical model, including the material properties of the two contact bodies and factors arising from the manufacturing processes. The transverse Young's modulus of chopped carbon fibers in the GDL and the surface profile of the BPP are found to be significant to the contact resistance. The factor study also sheds light on the manufacturing requirements of carbon fiber GDLs for a better contact performance in PEM fuel cells.

  10. An analytical model and parametric study of electrical contact resistance in proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhiliang; Wang, Shuxin; Zhang, Lianhong [School of Mechanical Engineering, Tianjin University, Tianjin 300072 (China); Hu, S. Jack [Department of Mechanical Engineering, The University of Michigan, Ann Arbor, MI 48109-2125 (United States)

    2009-04-15

    This paper presents an analytical model of the electrical contact resistance between the carbon paper gas diffusion layers (GDLs) and the graphite bipolar plates (BPPs) in a proton exchange membrane (PEM) fuel cell. The model is developed based on the classical statistical contact theory for a PEM fuel cell, using the same probability distributions of the GDL structure and BPP surface profile as previously described in Wu et al. [Z. Wu, Y. Zhou, G. Lin, S. Wang, S.J. Hu, J. Power Sources 182 (2008) 265-269] and Zhou et al. [Y. Zhou, G. Lin, A.J. Shih, S.J. Hu, J. Power Sources 163 (2007) 777-783]. Results show that estimates of the contact resistance compare favorably with experimental data by Zhou et al. [Y. Zhou, G. Lin, A.J. Shih, S.J. Hu, J. Power Sources 163 (2007) 777-783]. Factors affecting the contact behavior are systematically studied using the analytical model, including the material properties of the two contact bodies and factors arising from the manufacturing processes. The transverse Young's modulus of chopped carbon fibers in the GDL and the surface profile of the BPP are found to be significant to the contact resistance. The factor study also sheds light on the manufacturing requirements of carbon fiber GDLs for a better contact performance in PEM fuel cells. (author)

  11. Constant Power Control of a Proton Exchange Membrane Fuel Cell through Adaptive Fuzzy Sliding Mode

    Directory of Open Access Journals (Sweden)

    Minxiu Yan

    2013-05-01

    Full Text Available Fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent. The paper describes a mathematical model of proton exchange membrane fuel cells by analyzing the working mechanism of the proton exchange membrane fuel cell. Furthermore, an adaptive fuzzy sliding mode controller is designed for the constant power output of PEMFC system. Simulation results prove that adaptive fuzzy sliding mode control has better control effect than conventional fuzzy sliding mode control.

  12. Effect of gas diffusion layer and membrane properties in an annular proton exchange membrane fuel cell

    Science.gov (United States)

    Khazaee, I.; Ghazikhani, M.; Esfahani, M. Nasr

    2012-01-01

    A complete three-dimensional and single phase computational dynamics model for annular proton exchange membrane (PEM) fuel cell is used to investigate the effect of changing gas diffusion layer and membrane properties on the performances, current density and gas concentration. The proposed model is a full cell model, which includes all the parts of the PEM fuel cell, flow channels, gas diffusion electrodes, catalyst layers and the membrane. Coupled transport and electrochemical kinetics equations are solved in a single domain; therefore no interfacial boundary condition is required at the internal boundaries between cell components. This computational fluid dynamics code is used as the direct problem solver, which is used to simulate the two-dimensional mass, momentum and species transport phenomena as well as the electron- and proton-transfer process taking place in a PEMFC that cannot be investigated experimentally. The results show that by increasing the thickness and decreasing the porosity of GDL the performance of the cell enhances that it is different with planner PEM fuel cell. Also the results show that by decreasing the thickness of the membrane the performance of the cell increases.

  13. The Investigation and Development of Low Cost Hardware Components for Proton-Exchange Membrane Fuel Cells - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    George A. Marchetti

    1999-12-15

    Proton exchange membrane (PEM) fuel cell components, which would have a low-cost structure in mass production, were fabricated and tested. A fuel cell electrode structure, comprising a thin layer of graphite (50 microns) and a front-loaded platinum catalyst layer (600 angstroms), was shown to produce significant power densities. In addition, a PEM bipolar plate, comprising flexible graphite, carbon cloth flow-fields and an integrated polymer gasket, was fabricated. Power densities of a two-cell unit using this inexpensive bipolar plate architecture were shown to be comparable to state-of-the-art bipolar plates.

  14. High temperature proton exchange membranes based on polybenzimidazoles for fuel cells

    DEFF Research Database (Denmark)

    Li, Qingfeng; Jensen, Jens Oluf; Savinell, Robert F;

    2009-01-01

    in recent years motivated extensive research activities with great progress. This treatise is devoted to updating the development, covering polymer synthesis, membrane casting, physicochemical characterizations and fuel cell technologies. To optimize the membrane properties, high molecular weight polymers...... havebeenmadeincluding spectroscopy,wateruptake and acid doping, thermal and oxidative stability, conductivity, electro-osmoticwater drag, methanol crossover, solubility and permeability of gases, and oxygen reduction kinetics. Related fuel cell technologies such as electrode and MEA fabrication have been developed...

  15. Fabrication of Pt deposited on carbon nanotubes and performance of its polymer electrolyte membrane fuel cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new method of depositing nano-sized Pt particles on the surface of the carbon nano-tubes was introduced, and the performance of Pt/carbon nanotube compound on polymer electrolyte membrane fuel cells was measured. The experimental results show that the fine platinum particles (about 3 nm) were well dispersed on carbon nanotubes, which demonstrates the excellent catalytic properties of the Pt/CNTs compound in polymer electrolyte membrane fuel cells.

  16. The Pore Structure of Direct Methanol Fuel Cell Electrodes

    DEFF Research Database (Denmark)

    Lund, Peter Brilner

    2005-01-01

    The pore structure and morphology of direct methanol fuel cell electrodes are characterized using mercury intrusion porosimetry and scanning electron microscopy. It is found that the pore size distributions of printed primer and catalyst layers are largely dictated by the powders used to make the...

  17. Impedance study of membrane dehydration and compression in proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Le Canut, Jean-Marc; Latham, Ruth; Merida, Walter; Harrington, David A. [Institute for Integrated Energy Systems, University of Victoria, Victoria, British Columbia (Canada)

    2009-07-15

    Electrochemical impedance spectroscopy (EIS) is used to measure drying and rehydration in proton exchange membrane fuel cells running under load. The hysteresis between forward and backward acquisition of polarization curves is shown to be largely due to changes in the membrane resistance. Drying tests are carried out with hydrogen and simulated reformate (hydrogen and carbon dioxide), and quasi-periodic drying and rehydration conditions are studied. The membrane hydration state is clearly linked to the high-frequency arc in the impedance spectrum, which increases in size for dry conditions indicating an increase in membrane resistance. Changes in impedance spectra as external compression is applied to the cell assembly show that EIS can separate membrane and interfacial effects, and that changes in membrane resistance dominate. Reasons for the presence of a capacitance in parallel with the membrane resistance are discussed. (author)

  18. Improving dynamic performance of proton-exchange membrane fuel cell system using time delay control

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Bae [Mechanical Engineering Department, Chonnam National University, Gwangju (Korea)

    2010-10-01

    Transient behaviour is a key parameter for the vehicular application of proton-exchange membrane (PEM) fuel cell. The goal of this presentation is to construct better control technology to increase the dynamic performance of a PEM fuel cell. The PEM fuel cell model comprises a compressor, an injection pump, a humidifier, a cooler, inlet and outlet manifolds, and a membrane-electrode assembly. The model includes the dynamic states of current, voltage, relative humidity, stoichiometry of air and hydrogen, cathode and anode pressures, cathode and anode mass flow rates, and power. Anode recirculation is also included with the injection pump, as well as anode purging, for preventing anode flooding. A steady-state, isothermal analytical fuel cell model is constructed to analyze the mass transfer and water transportation in the membrane. In order to prevent the starvation of air and flooding in a PEM fuel cell, time delay control is suggested to regulate the optimum stoichiometry of oxygen and hydrogen, even when there are dynamical fluctuations of the required PEM fuel cell power. To prove the dynamical performance improvement of the present method, feed-forward control and Linear Quadratic Gaussian (LQG) control with a state estimator are compared. Matlab/Simulink simulation is performed to validate the proposed methodology to increase the dynamic performance of a PEM fuel cell system. (author)

  19. Improving dynamic performance of proton-exchange membrane fuel cell system using time delay control

    Science.gov (United States)

    Kim, Young-Bae

    Transient behaviour is a key parameter for the vehicular application of proton-exchange membrane (PEM) fuel cell. The goal of this presentation is to construct better control technology to increase the dynamic performance of a PEM fuel cell. The PEM fuel cell model comprises a compressor, an injection pump, a humidifier, a cooler, inlet and outlet manifolds, and a membrane-electrode assembly. The model includes the dynamic states of current, voltage, relative humidity, stoichiometry of air and hydrogen, cathode and anode pressures, cathode and anode mass flow rates, and power. Anode recirculation is also included with the injection pump, as well as anode purging, for preventing anode flooding. A steady-state, isothermal analytical fuel cell model is constructed to analyze the mass transfer and water transportation in the membrane. In order to prevent the starvation of air and flooding in a PEM fuel cell, time delay control is suggested to regulate the optimum stoichiometry of oxygen and hydrogen, even when there are dynamical fluctuations of the required PEM fuel cell power. To prove the dynamical performance improvement of the present method, feed-forward control and Linear Quadratic Gaussian (LQG) control with a state estimator are compared. Matlab/Simulink simulation is performed to validate the proposed methodology to increase the dynamic performance of a PEM fuel cell system.

  20. Simulation and in situ measurement of stress distribution in a polymer electrolyte membrane fuel cell stack

    Science.gov (United States)

    de la Cruz, Javier; Cano, Ulises; Romero, Tatiana

    2016-10-01

    A critical parameter for PEM fuel cell's electric contact is the nominal clamping pressure. Predicting the mechanical behavior of all components in a fuel cell stack is a very complex task due to the diversity of materials properties. Prior to the integration of a 3 kW PEMFC power plant, a numerical simulation was performed in order to obtain the mechanical stress distribution for two of the most pressure sensitive components of the stack: the membrane, and the graphite plates. The stress distribution of the above mentioned components was numerically simulated by finite element analysis and the stress magnitude for the membrane was confirmed using pressure films. Stress values were found within the elastic zone which guarantees mechanical integrity of fuel cell components. These low stress levels particularly for the membrane will allow prolonging the life and integrity of the fuel cell stack according to its design specifications.

  1. Improved Performance of Sulfonated Polyarylene Ethers for Proton Exchange Membrane Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    D. Xing; J. Kerres; F. Sch(o)nberger

    2005-01-01

    @@ 1Introduction The proton exchange membrane (PEM) is one of key components in fuel cell system. Its properties are very important in determining PEMFC performance. The membranes presently used in fuel cell are perfluorosulfonic polymers, such as Nafion(R) from Dupont. Although they have high proton conductivity and excellent chemical stability, their too high production cast and methanol permeability lead to failure of fuel cell application. Therefore, various partially fluorinated and non-fluorinated polymer electrolytes are under development for PEMFC application since one decade. In the middle of non-fluorinated polymer electrolytes, sulfonated poly(arylene ether)s display high thermal stability, good mechanical properties and exceptional resistance to oxidation and acid catalyzed hydrolysis. They have been regarded as well-suited proton exchange membrane candidates for fuel cells.

  2. A review of water flooding issues in the proton exchange membrane fuel cell

    Science.gov (United States)

    Li, Hui; Tang, Yanghua; Wang, Zhenwei; Shi, Zheng; Wu, Shaohong; Song, Datong; Zhang, Jianlu; Fatih, Khalid; Zhang, Jiujun; Wang, Haijiang; Liu, Zhongsheng; Abouatallah, Rami; Mazza, Antonio

    We have reviewed more than 100 references that are related to water management in proton exchange membrane (PEM) fuel cells, with a particular focus on the issue of water flooding, its diagnosis and mitigation. It was found that extensive work has been carried out on the issues of flooding during the last two decades, including prediction through numerical modeling, detection by experimental measurements, and mitigation through the design of cell components and manipulating the operating conditions. Two classes of strategies to mitigate flooding have been developed. The first is based on system design and engineering, which is often accompanied by significant parasitic power loss. The second class is based on membrane electrode assembly (MEA) design and engineering, and involves modifying the material and structural properties of the gas diffusion layer (GDL), cathode catalyst layer (CCL) and membrane to function in the presence of liquid water. In this review, several insightful directions are also suggested for future investigation.

  3. Commercialization of proton exchange membrane fuel cells for transportation applications

    Energy Technology Data Exchange (ETDEWEB)

    Wismer, L.

    1996-04-01

    Environmental concerns with air quality and global warming have triggered strict federal ambient ozone air quality standards. Areas on non-attainment of these standards exist across the United States. Because it contains several of the most difficult attainment areas, the State of California has adopted low emission standards including a zero emission vehicle mandate that has given rise to development of hybrid electric vehicles, both battery-powered and fuel-cell powered. Fuel cell powered vehicles, using on-board hydrogen as a fuel, share the non-polluting advantage of the battery electric vehicle while offering at least three times the range today`s battery technology.

  4. 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...

  5. Gas diffusion layer for proton exchange membrane fuel cells - A review

    Energy Technology Data Exchange (ETDEWEB)

    Cindrella, L. [Fuel Cell Research Laboratory, Department of Engineering Technology, Arizona State University, Mesa, AZ 85212 (United States); Department of Chemistry, National Institute of Technology, Tiruchirappalli 620015 (India); Kannan, A.M.; Lin, J.F.; Saminathan, K. [Fuel Cell Research Laboratory, Department of Engineering Technology, Arizona State University, Mesa, AZ 85212 (United States); Ho, Y. [Department of Biotechnology, College of Health Science, Asia University, Taichung 41354 (China); Lin, C.W. [Department of Chemical Engineering, National Yunlin University of Science and Technology, Yunlin 640 (China); Wertz, J. [Hollingsworth and Vose Co., A.K. Nicholson Research Lab, 219 Townsend Road, West Groton, MA 01472 (United States)

    2009-10-20

    Gas diffusion layer (GDL) is one of the critical components acting both as the functional as well as the support structure for membrane-electrode assembly in the proton exchange membrane fuel cell (PEMFC). The role of the GDL is very significant in the H{sub 2}/air PEM fuel cell to make it commercially viable. A bibliometric analysis of the publications on the GDLs since 1992 shows a total of 400+ publications (>140 papers in the Journal of Power Sources alone) and reveals an exponential growth due to reasons that PEMFC promises a lot of potential as the future energy source for varied applications and hence its vital component GDL requires due innovative analysis and research. This paper is an attempt to pool together the published work on the GDLs and also to review the essential properties of the GDLs, the method of achieving each one of them, their characterization and the current status and future directions. The optimization of the functional properties of the GDLs is possible only by understanding the role of its key parameters such as structure, porosity, hydrophobicity, hydrophilicity, gas permeability, transport properties, water management and the surface morphology. This paper discusses them in detail to provide an insight into the structural parts that make the GDLs and also the processes that occur in the GDLs under service conditions and the characteristic properties. The required balance in the properties of the GDLs to facilitate the counter current flow of the gas and water is highlighted through its characteristics. (author)

  6. 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.

  7. New polymeric electrolyte membranes based on proton donor proton acceptor properties for direct methanol fuel cells

    NARCIS (Netherlands)

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

    2002-01-01

    In order to reduce the high methanol permeability of membranes in a direct methanol fuel cell application new and better materials are still required. In this paper membranes made from polybenzimidazole/sulfonated polysulfone are given and compared with homopolymer membranes made from sulfonated pol

  8. Optimization of fuel cell membrane electrode assemblies for transition metal ion-chelating ordered mesoporous carbon cathode catalysts

    OpenAIRE

    Johanna K. Dombrovskis; Cathrin Prestel; Anders E. C. Palmqvist

    2014-01-01

    Transition metal ion-chelating ordered mesoporous carbon (TM-OMC) materials were recently shown to be efficient polymer electrolyte membrane fuel cell (PEMFC) catalysts. The structure and properties of these catalysts are largely different from conventional catalyst materials, thus rendering membrane electrode assembly (MEA) preparation parameters developed for conventional catalysts not useful for applications of TM-OMC catalysts. This necessitates development of a methodology to incorporate...

  9. Preparation and characterization of polymeric membranes for fuel cells

    KAUST Repository

    Nunes, Suzana Pereira

    2012-06-24

    This paper summarized part of the material development for fuel cell conducted in my group in the last 10 years, based on new functionalized polymers with phosphonic, sulfonic as well as oxadiazole and triazole sites. © 2012 Bentham Science Publishers. All rights reserved.

  10. Preparation and characterization of mono-sheet bipolar membranes by pre-irradiation grafting method for fuel cell applications

    Science.gov (United States)

    Guan, Yingjie; Fang, Jun; Fu, Tao; Zhou, Huili; Wang, Xin; Deng, Zixiang; Zhao, Jinbao

    2016-09-01

    A new method for the preparation of the mono-sheet bipolar membrane applied to fuel cells was developed based on the pre-irradiation grafting technology. A series of bipolar membranes were successfully prepared by simultaneously grafting of styrene onto one side of the poly(ethylene-co-tetrafluoroethylene) base film and 1-vinylimidazole onto the opposite side, followed by the sulfonation and alkylation, respectively. The chemical structures and microstructures of the prepared membranes were investigated by ATR-FTIR and SEM-EDS. The TGA measurements demonstrated the prepared bipolar membranes have reasonable thermal stability. The ion exchange capacity, water uptake and ionic conductivity of the membranes were also characterized. The H2/O2 single fuel cells using these membranes were evaluated and revealed a maximum power density of 107 mW cm-2 at 35 °C with unhumidified hydrogen and oxygen. The preliminary performances suggested the great prospect of these membranes in application of bipolar membrane fuel cells.

  11. Modeling of durability of polyelectrolyte membrane of O2/H2 fuel cell

    CERN Document Server

    Atrazhev, Vadim V

    2014-01-01

    In this paper, we discuss critical aspects of the mechanisms and features of polymer proton exchange membrane (PEM) degradation in low-temperature H2/O2 fuel cell. In this paper, we focused on chemical mechanism of OH radical generation and their distribution in operational fuel cell. According to the current concept, free radicals are generated from hydrogen and oxygen crossover gases at the surface of Pt particles that precipitated in the membrane. We explicitly calculate Pt precipitation rate and electrochemical potential distribution in the membrane that controls it. Based on radical generation rate and Pt distribution we calculate degradation rate of the membrane taking advantage of simple kinetics equations.

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

    Science.gov (United States)

    Celik, Muhammet; Genc, Gamze; Elden, Gulsah; Yapici, Huseyin

    2016-03-01

    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.

  13. Polarity governed selective amplification of through plane proton shuttling in proton exchange membrane fuel cells.

    Science.gov (United States)

    Gautam, Manu; Chattanahalli Devendrachari, Mruthyunjayachari; Thimmappa, Ravikumar; Raja Kottaichamy, Alagar; Pottachola Shafi, Shahid; Gaikwad, Pramod; Makri Nimbegondi Kotresh, Harish; Ottakam Thotiyl, Musthafa

    2017-03-15

    Graphene oxide (GO) anisotropically conducts protons with directional dominance of in plane ionic transport (σ IP) over the through plane (σ TP). In a typical H2-O2 fuel cell, since the proton conduction occurs through the plane during its generation at the fuel electrode, it is indeed inevitable to selectively accelerate GO's σ TP for advancement towards a potential fuel cell membrane. We successfully achieved ∼7 times selective amplification of GO's σ TP by tuning the polarity of the dopant molecule in its nanoporous matrix. The coexistence of strongly non-polar and polar domains in the dopant demonstrated a synergistic effect towards σ TP with the former decreasing the number of water molecules coordinated to protons by ∼3 times, diminishing the effects of electroosmotic drag exerted on ionic movements, and the latter selectively accelerating σ TP across the catalytic layers by bridging the individual GO planes via extensive host guest H-bonding interactions. When they are decoupled, the dopant with mainly non-polar or polar features only marginally enhances the σ TP, revealing that polarity factors contribute to fuel cell relevant transport properties of GO membranes only when they coexist. Fuel cell polarization and kinetic analyses revealed that these multitask dopants increased the fuel cell performance metrics of the power and current densities by ∼3 times compared to the pure GO membranes, suggesting that the functional group factors of the dopants are of utmost importance in GO-based proton exchange membrane fuel cells.

  14. 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.

  15. Role of membranes and membrane reactors in the hydrogen supply of fuel cells for transports

    Energy Technology Data Exchange (ETDEWEB)

    Julbe, A.; Guizard, Ch. [Institut Europeen des Membranes, UMII, Lab. des Materiaux et des Procedes Membranaires, CNRS UMR 5635, 34 - Montpellier (France)

    2000-07-01

    Production, storage and supply of high-purity hydrogen as a clean and efficient fuel is central to fuel cells technology, in particular in vehicle traction. Actually, technologies for handling liquefied or gaseous hydrogen in transports are not available so that a number of alternative fuels are considered with the aim of in-situ generation of hydrogen through catalytic processes. The integrated concept of membrane reactors (MRs) can greatly benefit to these technologies. Particular emphasis is put on inorganic membranes and their role in MRs performance for H{sub 2} production.

  16. Oxidative degradation of polybenzimidazole membranes as electrolytes for high temperature proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

    Liao, J.H.; Li, Qingfeng; Rudbeck, H.C.

    2011-01-01

    the oxidative degradation of the polymer membrane was studied under the Fenton test conditions by the weight loss, intrinsic viscosity, size exclusion chromatography, scanning electron microscopy and Fourier transform infrared spectroscopy. During the Fenton test, significant weight losses depending......Polybenzimidazole membranes imbibed with acid are emerging as a suitable electrolyte material for high-temperature polymer electrolyte fuel cells. The oxidative stability of polybenzimidazole has been identified as an important issue for the long-term durability of such cells. In this paper...

  17. Performance of polymer nano composite membrane electrode assembly using Alginate as a dopant in polymer electrolyte membrane fuel cell

    Science.gov (United States)

    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.

  18. Performance of polymer nano composite membrane electrode assembly using Alginate as a dopant in polymer electrolyte membrane fuel cell

    Science.gov (United States)

    Mulijani, S.

    2016-11-01

    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.

  19. 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...

  20. Identification and analysis based on genetic algorithm for proton exchange membrane fuel cell stack

    Institute of Scientific and Technical Information of China (English)

    LI Xi; CAO Guang-yi; ZHU Xin-jian; WEI Dong

    2006-01-01

    The temperature of proton exchange membrane fuel cell stack and the stoichiometric oxygen in cathode have relationship with the performance and life span of fuel cells closely. The thermal coefficients were taken as important factors affecting the temperature distribution of fuel cells and components. According to the experimental analysis, when the stoichiometric oxygen in cathode is greater than or equal to 1.8, the stack voltage loss is the least. A novel genetic algorithm was developed to identify and optimize the variables in dynamic thermal model of proton exchange membrane fuel cell stack, making the outputs of temperature model approximate to the actual temperature, and ensuring that the maximal error is less than 1℃. At the same time, the optimum region of stoichiometric oxygen is obtained, which is in the range of 1.8 -2.2 and accords with the experimental analysis results. The simulation and experimental results show the effectiveness of the proposed algorithm.

  1. A review on the performance and modelling of proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Boucetta, A., E-mail: abirboucetta@yahoo.fr; Ghodbane, H., E-mail: h.ghodbane@mselab.org; Bahri, M., E-mail: m.bahri@mselab.org [Department of Electrical Engineering, MSE Laboratory, Mohamed khider Biskra University (Algeria); Ayad, M. Y., E-mail: ayadmy@gmail.com [R& D, Industrial Hybrid Vehicle Applications (France)

    2016-07-25

    Proton Exchange Membrane Fuel Cells (PEMFC), are energy efficient and environmentally friendly alternative to conventional energy conversion for various applications in stationary power plants, portable power device and transportation. PEM fuel cells provide low operating temperature and high-energy efficiency with near zero emission. A PEM fuel cell is a multiple distinct parts device and a series of mass, energy, transport through gas channels, electric current transport through membrane electrode assembly and electrochemical reactions at the triple-phase boundaries. These processes play a decisive role in determining the performance of the Fuel cell, so that studies on the phenomena of gas flows and the performance modelling are made deeply. This paper gives a comprehensive overview of the state of the art on the Study of the phenomena of gas flow and performance modelling of PEMFC.

  2. A review on the performance and modelling of proton exchange membrane fuel cells

    Science.gov (United States)

    Boucetta, A.; Ghodbane, H.; Ayad, M. Y.; Bahri, M.

    2016-07-01

    Proton Exchange Membrane Fuel Cells (PEMFC), are energy efficient and environmentally friendly alternative to conventional energy conversion for various applications in stationary power plants, portable power device and transportation. PEM fuel cells provide low operating temperature and high-energy efficiency with near zero emission. A PEM fuel cell is a multiple distinct parts device and a series of mass, energy, transport through gas channels, electric current transport through membrane electrode assembly and electrochemical reactions at the triple-phase boundaries. These processes play a decisive role in determining the performance of the Fuel cell, so that studies on the phenomena of gas flows and the performance modelling are made deeply. This paper gives a comprehensive overview of the state of the art on the Study of the phenomena of gas flow and performance modelling of PEMFC.

  3. Nafion®/ODF-silica composite membranes for medium temperature proton exchange membrane fuel cells

    KAUST Repository

    Treekamol, Yaowapa

    2014-01-01

    A series of composite membranes were prepared by dispersing fluorinated polyoxadiazole oligomer (ODF)-functionalized silica nanoparticles in a Nafion matrix. Both melt-extrusion and solvent casting processes were explored. Ion exchange capacity, conductivity, water uptake and dimensional stability, thermal stability and morphology were characterized. The inclusion of functionalized nanoparticles proved advantageous, mainly due to a physical crosslinking effect and better water retention, with functionalized nanoparticles performing better than the pristine silica particles. For the same filler loading, better nanoparticle dispersion was achieved for solvent-cast membranes, resulting in higher proton conductivity. Filler agglomeration, however,was more severe for solvent-castmembranes at loadings beyond 5wt.%. The composite membranes showed excellent thermal stability, allowing for operation in medium temperature PEM fuel cells. Fuel cell performance of the compositemembranesdecreaseswithdecreasing relativehumidity, but goodperformance values are still obtained at 34% RHand 90 °C,with the best results obtained for solvent castmembranes loaded with 10 wt.% ODF-functionalized silica. Hydrogen crossover of the composite membranes is higher than that forpureNafion membranes,possiblydue toporosityresulting fromsuboptimalparticle- matrixcompatibility. © 2013 Crown Copyright and Elsevier BV. All rights reserved.

  4. Water Transport Analysis in Polymer Electrolyte Membrane Fuel Cells by Magnetic Resonance Imaging

    Institute of Scientific and Technical Information of China (English)

    S.Tsushima; S.Hirai

    2007-01-01

    1 Results Polymer electrolyte fuel cells (PEFCs) have beenintensively developedfor future vehicle applications andon-site power generation owing to its high energy efficiency and high power density.In PEFCs ,appropriatewater management to maintain polymer electrolyte membrane (PEM) hydratedis of great i mportance ,becausethe ion conductivity of membraneislower at lower water content .Consequently,it is of great interest to watercontent and water transport process in PEMs during fuel cell operation.

  5. Process for recycling components of a PEM fuel cell membrane electrode assembly

    Science.gov (United States)

    Shore, Lawrence [Edison, NJ

    2012-02-28

    The membrane electrode assembly (MEA) of a PEM fuel cell can be recycled by contacting the MEA with a lower alkyl alcohol solvent which separates the membrane from the anode and cathode layers of the assembly. The resulting solution containing both the polymer membrane and supported noble metal catalysts can be heated under mild conditions to disperse the polymer membrane as particles and the supported noble metal catalysts and polymer membrane particles separated by known filtration means.

  6. Characterization of proton exchange membrane materials for fuel cells by solid state nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Zueqian [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    Solid-state nuclear magnetic resonance (NMR) has been used to explore the nanometer-scale structure of Nafion, the widely used fuel cell membrane, and its composites. We have shown that solid-state NMR can characterize chemical structure and composition, domain size and morphology, internuclear distances, molecular dynamics, etc. The newly-developed water channel model of Nafion has been confirmed, and important characteristic length-scales established. Nafion-based organic and inorganic composites with special properties have also been characterized and their structures elucidated. The morphology of Nafion varies with hydration level, and is reflected in the changes in surface-to-volume (S/V) ratio of the polymer obtained by small-angle X-ray scattering (SAXS). The S/V ratios of different Nafion models have been evaluated numerically. It has been found that only the water channel model gives the measured S/V ratios in the normal hydration range of a working fuel cell, while dispersed water molecules and polymer ribbons account for the structures at low and high hydration levels, respectively.

  7. Sulfonated polystyrene-type plasma-polymerized membranes for miniature direct methanol fuel cells

    Science.gov (United States)

    Roualdes, Stéphanie; Topala, Ionut; Mahdjoub, Habiba; Rouessac, Vincent; Sistat, Philippe; Durand, Jean

    Sulfonated polystyrene-type membranes were synthesized by plasma polymerization of a mixture of styrene and trifluoromethane sulfonic acid monomers in a low-frequency after-glow discharge plasma reactor. Such a deposition process enables the preservation of the monomers structure, which was confirmed by mass spectrometry analysis. The synthesized plasma-polymerized membranes are dense and uniform with a few microns thickness. Their structure determined by Fourier-transform infra-red spectroscopy and X-ray photoelectron spectroscopy is very rich in sulfonic acid groups (up to 5%) and stable up to 120 °C. Even if their intrinsic proton conductivity is low (10 -1 mS cm -1), directly related to their disorganized and highly cross-linked structure, plasma-polymerized membranes present a proton conduction ability similar to Nafion ® because of their low thickness. Due to their highly cross-linked structure, these membranes enable a reduction of the methanol crossover in a factor 10 by comparison with Nafion ®. Thus, the integration of plasma-polymerized films in miniaturized direct methanol fuel cells as proton-exchange membranes seems promising.

  8. Pendant dual sulfonated poly(arylene ether ketone) proton exchange membranes for fuel cell application

    Science.gov (United States)

    Nguyen, Minh Dat Thinh; Yang, Sungwoo; Kim, Dukjoon

    2016-10-01

    Poly(arylene ether ketone) (PAEK) possessing carboxylic groups at the pendant position is synthesized, and the substitution degree of pendant carboxylic groups is controlled by adjusting the ratio of 4,4-bis(4-hydroxyphenyl)valeric acid and 2,2-bis(4-hydroxyphenyl)propane. Dual sulfonated 3,3-diphenylpropylamine (SDPA) is grafted onto PAEK as a proton-conducting moiety via the amidation reaction with carboxylic groups. The transparent and flexible membranes with different degrees of sulfonation are fabricated so that we can test and compare their structure and properties with a commercial Nafion® 115 membrane for PEMFC applications. All prepared PAEK-SDPA membranes exhibit good oxidative and hydrolytic stability from Fenton's and high temperature water immersion test. SAXS analysis illustrates an excellent phase separation between the hydrophobic backbone and hydrophilic pendant groups, resulting in big ionic clusters. The proton conductivity was measured at different relative humidity, and its behavior was analyzed by hydration number of the membrane. Among a series of membranes, some samples (including B20V80-SDPA) show not only higher proton conductivity, but also higher integrated cell performance than those of Nafion® 115 at 100% relative humidity, and thus we expect these to be good candidate membranes for proton exchange membrane fuel cells (PEMFCs).

  9. Development of large aperture projection scatterometry for catalyst loading evaluation in proton exchange membrane fuel cells

    Science.gov (United States)

    Stocker, Michael T.; Barnes, Bryan M.; Sohn, Martin; Stanfield, Eric; Silver, Richard M.

    2017-10-01

    Widespread commercialization of proton exchange membrane fuel cells remains curbed by various manufacturing and infrastructure challenges. One such technical barrier identified by the U. S. Department of Energy is the need for high-speed, in-line process control of platinum-based catalyst layers in the membrane electrode assembly of the fuel cell. Using multiple reflectivity-based optical methods, such as optical scatterometry and large aperture projection scatterometry, we demonstrate in-line-capable catalyst loading measurements of carbon-supported Pt nanoparticle and Pt-alloy nanostructured thin film catalyst coated membranes. Large aperture projection scatterometry is a new high-throughput approach developed at the National Institute of Standards and Technology specifically for fuel cell manufacturing metrology. Angle- and wavelength-resolved measurements of these fuel cell soft goods validate the ability of reflectivity-based measurements to produce industrially relevant sensitivities to changes in Pt and Pt-alloy loading. The successful application of these optical methods to fuel cell manufacturing metrology directly addresses the shortage of high-throughput process control approaches needed to facilitate performance improvements and manufacturing cost-reductions required to make fuel cells commercially viable.

  10. New Membranes Based on Polybenzimidazole for Polymer Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    P.Mustarelli; E.Quartarone; S; Grandi; A.Carollo; S.Leonardi; A.Magistris

    2007-01-01

    1 Results Acid-doped polybenzimidazoles[1] are particularly appealing because of high proton conductivity with no or low humidification and promising fuel cells performances. PBI, in fact, contains basic functional groups which can easily interact with strong oxo-acids, such as H3PO4 and H2SO4. The acid partially protonates the polymer and partially is freely dispersed in the polymer backbone, so allowing proton migration via Grotthuss mechanism along the anionic chains[2]. Anyway, a technological limit...

  11. Imidazolium-Based Polymeric Materials as Alkaline Anion-Exchange Fuel Cell Membranes

    Science.gov (United States)

    Narayan, Sri R.; Yen, Shiao-Ping S.; Reddy, Prakash V.; Nair, Nanditha

    2012-01-01

    Polymer electrolyte membranes that conduct hydroxide ions have potential use in fuel cells. A variety of polystyrene-based quaternary ammonium hydroxides have been reported as anion exchange fuel cell membranes. However, the hydrolytic stability and conductivity of the commercially available membranes are not adequate to meet the requirements of fuel cell applications. When compared with commercially available membranes, polystyrene-imidazolium alkaline membrane electrolytes are more stable and more highly conducting. At the time of this reporting, this has been the first such usage for imidazolium-based polymeric materials for fuel cells. Imidazolium salts are known to be electrochemically stable over wide potential ranges. By controlling the relative ratio of imidazolium groups in polystyrene-imidazolium salts, their physiochemical properties could be modulated. Alkaline anion exchange membranes based on polystyrene-imidazolium hydroxide materials have been developed. The first step was to synthesize the poly(styrene-co-(1-((4-vinyl)methyl)-3- methylimidazolium) chloride through a free-radical polymerization. Casting of this material followed by in situ treatment of the membranes with sodium hydroxide solutions provided the corresponding hydroxide salts. Various ratios of the monomers 4-chloromoethylvinylbenzine (CMVB) and vinylbenzine (VB) provided various compositions of the polymer. The preferred material, due to the relative ease of casting the film, and its relatively low hygroscopic nature, was a 2:1 ratio of CMVB to VB. Testing confirmed that at room temperature, the new membranes outperformed commercially available membranes by a large margin. With fuel cells now in use at NASA and in transportation, and with defense potential, any improvement to fuel cell efficiency is a significant development.

  12. A Mathematical Model for Predicting the Life of PEM Fuel Cell Membranes Subjected to Hydration Cycling

    CERN Document Server

    Burlatsky, S F; O'Neill, J; Atrazhev, V V; Varyukhin, A N; Dmitriev, D V; Erikhman, N S

    2013-01-01

    Under typical PEM fuel cell operating conditions, part of membrane electrode assembly is subjected to humidity cycling due to variation of inlet gas RH and/or flow rate. Cyclic membrane hydration/dehydration would cause cyclic swelling/shrinking of the unconstrained membrane. In a constrained membrane, it causes cyclic stress resulting in mechanical failure in the area adjacent to the gas inlet. A mathematical modeling framework for prediction of the lifetime of a PEM FC membrane subjected to hydration cycling is developed in this paper. The model predicts membrane lifetime as a function of RH cycling amplitude and membrane mechanical properties. The modeling framework consists of three model components: a fuel cell RH distribution model, a hydration/dehydration induced stress model that predicts stress distribution in the membrane, and a damage accrual model that predicts membrane life-time. Short descriptions of the model components along with overall framework are presented in the paper. The model was used...

  13. Employing Hot Wire Anemometry to Directly Measure the Water Balance in a Proton Exchange membrane Fuel Cell

    DEFF Research Database (Denmark)

    Shakhshir, Saher Al; Hussain, Nabeel; Berning, Torsten

    2015-01-01

    Water management in proton exchange membrane fuel cells (PEMFC’s) remains a critical problem for their durability, cost, and performance. Because the anode side of this fuel cell has the tendency to become dehydrated, measuring the water balance can be an important diagnosis tool during fuel cell...... can be directly converted into the fuel cell water balance. In this work, experimental ex-situ results are presented and the elegance and usefulness of this method is demonstrated....

  14. Porous matrix structures for alkaline electrolyte fuel cells

    Science.gov (United States)

    Vine, R. W.; Narsavage, S. T.

    1975-01-01

    A number of advancements have been realized by a continuing research program to develop higher chemically stable porous matrix structures with high bubble pressure (crossover resistance) for use as separators in potassium hydroxide electrolyte fuel cells. More uniform, higher-bubble-pressure asbestos matrices were produced by reconstituting Johns-Manville asbestos paper; Fybex potassium titanate which was found compatible with 42% KOH at 250 F for up to 3000 hr; good agreement was found between bubble pressures predicted by an analytical study and those measured with filtered structures; Teflon-bonded Fybex matrices with bubble pressures greater than 30 psi were obtained by filtering a water slurry of the mixture directly onto fuel cell electrodes; and PBI fibers have satisfactory compatibility with 42% KOH at 250 F.

  15. Enhancement of the fuel cell performance of a high temperature proton exchange membrane fuel cell running with titanium composite polybenzimidazole-based membranes

    Science.gov (United States)

    Lobato, Justo; Cañizares, Pablo; Rodrigo, Manuel A.; Úbeda, Diego; Pinar, F. Javier

    2011-10-01

    The fuel cell performance of a composite PBI-based membrane with TiO2 has been studied. The behaviour of the membrane has been evaluated by comparison with the fuel cell performance of other PBI-based membranes, all of which were cast from the same polymer with the same molecular weight. The PBI composite membrane incorporating TiO2 showed the best performance and reached 1000 mW cm-2 at 175 °C. Moreover, this new titanium composite PBI-based membrane also showed the best stability during the preliminary long-term test under our operation conditions. Thus, the slope of the increase in the ohmic resistance of the composite membrane was 0.041 mΩ cm2 h-1 and this is five times lower than that of the standard PBI membrane. The increased stability was due to the high phosphoric acid retention capacity - as confirmed during leaching tests, in which the Ti-based composite PBI membrane retained 5 mol of H3PO4/PBI r.u. whereas the PBI standard membrane only retained 1 mol H3PO4/PBI r.u. Taking into account the results obtained in this study, the TiO2-PBI based membranes are good candidates as electrolytes for high temperature PEMFCs.

  16. Radiolytic synthesis and characterization of PVA and chitosan based conductive polymer membranes for alkaline fuel cells

    Directory of Open Access Journals (Sweden)

    Stoševski Ivan D.

    2014-01-01

    Full Text Available Poly(vinyl alcohol (PVA and chitosan (CS based polymer membranes for alkaline fuel cells were synthesized by gamma irradiation method. They were swollen with 6 M KOH solution and their ionic conductivity and gas permeance were investigated as a function of temperature. They show high ionic conductivities at room temperature, which wasn't reduced over a period of few months. No gas flow through membranes was detected at any temperature and pressure. These properties show that the membranes could be potentially applied in alkaline fuel cells.

  17. Anionic-exchange membrane development for application in alcohol alkaline fuel cells

    CSIR Research Space (South Africa)

    Nonjola, S

    2010-09-01

    Full Text Available into electrical energy and heat using electrochemical process © CSIR 2010 Slide 4 Fuel Cell Types • Alkaline (AFC) developed for the Apollo program • Polymer membrane (PEMC) leading candidate for transportation • Phosphoric acid (PAFC) 200kW units... Slide 11 Membrane Development • Polymer electrolyte fuel cell (PEFC) – most developed in the past 2 decades. • PEFC – acidic membrane (Nafion) as an electrolyte. • Nafion based FCs several obstacles such as: dependence on Pt catalysts and Me...

  18. MICROBIAL FUEL CELL BASED POLYSTYRENE SULFONATED MEMBRANE AS PROTON EXCHANGE MEMBRANE

    Directory of Open Access Journals (Sweden)

    S. Mulijani

    2016-09-01

    Full Text Available Microbial fuel cell (MFC represents a major bioelectrochemical system that converts biomass spontaneously into electricity through the activity of microorganisms. The MFC consists of anode and cathode compartments. Microorganisms in MFC liberate electrons while the electron donor is consumed. The produced electron is transmitted to the anode surface, but the generated protons must pass through the proton exchange membrane (PEM to reach the cathode compartment. PEM, as a key factor, affects electricity generation in MFCs. The study attempted to investigate if the sulfonated polystyrene (SPS membrane can be used as a PEM in the application on MFC. SPS membrane has been characterized using Fourier transform infrared spectrophotometer (FTIR, scanning electron microscope (SEM and conductivity. The result of the conductivity (σ revealed that the membrane has a promising application for MFC.

  19. Using Polymer Electrolyte Membrane Fuel Cells in a Hybrid Surface Ship Propulsion Plant to Increase Fuel Efficiency

    Science.gov (United States)

    2010-06-01

    Using Polymer Electrolyte Membrane Fuel Cells in a Hybrid Surface Ship Propulsion Plant to Increase Fuel Efficiency by Douglas M. Kroll B.S...Electrolyte Membrane Fuel Cells in a Hybrid Surface Ship Propulsion Plant to Increase Fuel Efficiency 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Using Polymer Electrolyte Membrane Fuel Cells in a Hybrid Surface Ship Propulsion Plant to Increase

  20. 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.

  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. Covalently Cross-Linked Sulfone Polybenzimidazole Membranes with Poly(Vinylbenzyl Chloride) for Fuel Cell Applications

    DEFF Research Database (Denmark)

    Yang, Jingshuai; Aili, David; Li, Qingfeng;

    2013-01-01

    Covalently cross-linked polymer membranes were fabricated from poly(aryl sulfone benzimidazole) (SO(2) PBI) and poly(vinylbenzyl chloride) (PVBCl) as electrolytes for high-temperature proton-exchange-membrane fuel cells. The cross-linking imparted organo insolubility and chemical stability against...

  3. Simplified process for leaching precious metals from fuel cell membrane electrode assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Shore, Lawrence (Edison, NJ); Matlin, Ramail (Berkeley Heights, NJ)

    2009-12-22

    The membrane electrode assemblies of fuel cells are recycled to recover the catalyst precious metals from the assemblies. The assemblies are cryogenically embrittled and pulverized to form a powder. The pulverized assemblies are then mixed with a surfactant to form a paste which is contacted with an acid solution to leach precious metals from the pulverized membranes.

  4. Water Uptake and Acid Doping of Polybenzimidazoles as Electrolyte Membranes for Fuel Cells

    DEFF Research Database (Denmark)

    Qingfeng, Li; He, R.; Berg, Rolf W.

    2004-01-01

    Acid-doped polybenzimidazole (PBI) membranes have been demonstrated for fuel cell applications with advanced features such as high operating temperatures, little humidification, excellent CO tolerance, and promising durability. The water uptake and acid doping of PBI membranes have been studied. ...

  5. Characterization of anionic-exchange membranes for direct alcohol alkaline fuel cells

    CSIR Research Space (South Africa)

    Abuin, GC

    2009-06-01

    Full Text Available and Young modulus were evaluated and compared to other membrane materials commonly employed in PEM fuel cells. A quartz crystal microbalance (QMC) was used to measure the water uptake of thin membranes of this material casted over the quartz crystals...

  6. Investigation of membrane electrode assemblies (MEAs) for efficient and optimum performance of polymer electrolyte membrane (PEM) fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Okafor, A.C.; Mogbo, H.M.C. [Missouri Univ. of Science and Technology, Rolla, MO (United States). Dept. of Mechanical and Aerospace Engineering

    2009-07-01

    The core component of a proton exchange membrane (PEM) fuel cell is the membrane electrode assembly (MEA) which includes an assembled stack of ion exchange membrane reaction catalysts, and the electrodes that converts hydrogen ions into electricity. This study investigated various MEAs in an effort to improve fuel cell performance and durability. First, a literature review of different commercially available and innovative PEM fuel cell MEAs was conducted. The best performing MEAs were then investigated in terms of fuel cell output voltage, operating temperature, thermal and chemical stability, methanol permeability, proton conductivity, and hydrogen crossover. The selected MEAs based on their high output voltage, ability to withstand chemical/radical attacks, overall fuel cell performance, and other excellent physical properties were identified as phosphoric acid-doped polybenzimidazole (PBI/H{sub 3}PO{sub 4}), disulfonated poly(sulfide sulfone)s (SPSSF), and Nafion 212. Finally, in-house designed and manufactured bipolar plates of different materials and flow field configurations are being used to validate these 3 identified MEAs in a single fuel cell and 3 fuel cell stacks.

  7. Sulfonated carbon black-based composite membranes for fuel cell applications

    Indian Academy of Sciences (India)

    Hacer Doǧan; Emel Yildiz; Metin Kaya; Tülay Y Inan

    2013-08-01

    Two different commercial grade carbon black samples, Cabot Regal 400R (C1) and Cabot Mogul L (C2), were sulfonated with diazonium salt of sulfanilic acid. The resultant sulfonated carbon black samples (S–C) were characterized by Fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analysis (TGA). Composite membranes were then prepared using S–C as fillers and sulfonated poly(ether ether ketone) (SPEEK) as polymer matrix with three different sulfonation degrees (DS = 60, 70 and 82%). Structure and properties of the composite membranes were characterized by FTIR, TGA, scanning electron microscopy, proton conduction, water uptake, ion exchange capacity and chemical stability. Incorporation of S–C particles above 0.25 wt% caused decrease in chemical stability. Pristine and composite membranes prepared from SPEEK82 decomposed completely in <1 h, which is undesirable for fuel cell applications. SPEEK60 membrane having wt% of 0.25–0.5 with S–C particles led to higher proton conductivity than that of pristine membrane. No positive effect was observed on the properties of the composite membranes with the addition of S–C particles at high concentrations due to the agglomeration problems and decrease in the content of conductive polymer matrix.

  8. Proton exchange membrane fuel cell diagnosis by spectral characterization of the electrochemical noise

    Science.gov (United States)

    Maizia, R.; Dib, A.; Thomas, A.; Martemianov, S.

    2017-02-01

    Electrochemical noise analysis (ENA) has been performed for the diagnosis of proton-exchange membrane fuel cell (PEMFC) under various operating conditions. Its interest is related with the possibility of a non-invasive on-line diagnosis of a commercial fuel cell. A methodology of spectral analysis has been developed and an evaluation of the stationarity of the signal has been proposed. It has been revealed that the spectral signature of fuel cell, is a linear slope with a fractional power dependence 1/fα where α = 2 for different relative humidities and current densities. Experimental results reveal that the electrochemical noise is sensitive to the water management, especially under dry conditions. At RHH2 = 20% and RHair = 20%, spectral analysis shows a three linear slopes signature on the spectrum at low frequency range (f power spectral density, calculated thanks to FFT, can be used for the detection of an incorrect fuel cell water balance.

  9. Binary and ternary nano-catalysts as cathode materials in proton exchange membrane fuel cells

    Science.gov (United States)

    Trimm, Bryan Dunning

    The need for alternative energy, in order to reduce dependence on petroleum based fuels, has increased in recent years. Public demand is at an all-time high for low emitting or none polluting energy sources, driving the research for cleaner technology. Lithium batteries and fuel cells have the ability to produce this alternative energy with much cleaner standards, while allowing for portability and high energy densities. This work focuses on the performance of nanocatalysts in Proton Exchange Membrane Fuel Cell or PEMFC. A key technical challenge is the sluggish rate for oxygen reduction reaction at the cathode of PEMFC, which requires highly-active and stable catalysts. Our investigation is directed at increasing stability and durability as well as reducing high loading of noble metals in these catalyst materials. Binary and ternary structured nanomaterials, e.g., Pt51V1Co48/C and Pd xCu1-x/C, have been synthesized and tested in a PEMFC, in order to gain a better understanding of their durability and efficiency. In addition to electrochemical characterization, synchrotron x-ray techniques at the Advance Photon Source in Argonne National Lab have also been used for the structural characterization.

  10. Nafion and modified-Nafion membranes for polymer electrolyte fuel cells: An overview

    Indian Academy of Sciences (India)

    A K Sahu; S Pitchumani; P Sridhar; A K Shukla

    2009-06-01

    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 presents an overview on Nafion membranes highlighting their merits and demerits with efforts on modified-Nafion membranes.

  11. A polybenzimidazole/ionic-liquid-graphite-oxide composite membrane for high temperature polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Xu, Chenxi; Liu, Xiaoteng; Cheng, Jigui; Scott, Keith

    2015-01-01

    Graphite oxide is successfully functionalised by 3-aminopropyltriethoxysilane ionic liquid and used as a filler material in a polybenzimidazole (PBI) membrane for high temperature proton exchange membrane fuel cells. The ionic-liquid-graphite-oxide/polybenzimidazole (ILGO/PBI) composite membrane exhibits an appropriate level of proton conductivity when imbibed with phosphoric acid at low phosphoric acid loading, which promotes its use in fuel cells by avoiding acid leakage and materials corrosion. The ionic conductivities of the ILGO/PBI membranes at 175 °C are 0.035 S cm-1 and 0.025 S cm-1 at per repeat units of 3.5 and 2.0, respectively. The fuel cell performance of ILGO/PBI membranes exhibits a maximum power density of 320 mW cm-2 at 175 °C, which is higher than that of a pristine PBI membrane.

  12. 有机溶剂对PEM燃料电池CCM结构和性能的影响%Effects of organic solvents on the structure and performance of catalyst coated membrane used in PEM fuel cells

    Institute of Scientific and Technical Information of China (English)

    张志远; 田建华; 单忠强; 梁宝臣

    2011-01-01

    Catalyst coated membrane (CCM) was prepared by direct spraying deposition of the catalyst on the surface of proton exchange membrane, which was then assembled with carbon paper diffusion layers to form a membrane electrode assembly (MEA) for the proton exchange membrane fuel cell (PEMFC). The mixture solution for preparing CCM was composed of 20% (mass ratio) Pt/C catalyst, 5% (mass ratio) Nafion solution, organic solvent and de-ionized water. The surface morphology and pore structure were characterized by the environmental scanning electron microscopy (SEM) and the polarization characteristics of MEA were evaluated by the current-voltage curves of a single PEMFC. The results indicated that the selection of solvent (ethanol, isopropyl alcohol and fert-butyl alcohol) as well as its content and volatility exhibit direct impact on the pore structure of catalyst layers of CCM, which affects the electrochemical performances of MEA. CCM fabricated with isopropyl alcohol solvent and a mass ratio of 4. 28 to Nafion solution under 50 Xl ~ 75 Xl exhibits an improved pore structure and I-V characteristic of MEA obtained.%采用直接喷涂法将催化剂涂覆在质子交换膜上形成CCM(catalyst coated membrane),CCM与碳纸扩散层组成膜电极用于质子交换膜燃料电池.制备CCM的混合液由质量分数20%的Pt/C催化剂、质量分数5%的Nafion溶液、有机溶剂和水组成.不同的有机溶剂(乙醇、异丙醇和叔丁醇)、有机溶剂的含量、溶剂的挥发速率直接影响所制备的CCM孔结构,进而影响膜电极的电化学性能.采用扫描电镜(SEM)表征了膜电极的表面形貌和孔结构;采用单体质子交换膜燃料电池(PEMFC)的电流密度-电压曲线评价了膜电极的极化特性.实验结果表明,以异丙醇为溶剂,异丙醇与Nafion溶液的质量比为4.28,在 50℃~75℃制备的CCM具有良好的孔结构和膜电极性能.

  13. Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications

    Energy Technology Data Exchange (ETDEWEB)

    Oei, D.; Adams, J.A.; Kinnelly, A.A. [and others

    1997-07-01

    In partial fulfillment of the U.S. Department of Energy Contract No. DE-ACO2-94CE50389, {open_quotes}Direct Hydrogen-Fueled Proton-Exchange-Membrane (PEM) Fuel Cell System for Transportation Applications{close_quotes}, this conceptual vehicle design report addresses the design and packaging of battery augmented fuel cell powertrain vehicles. This report supplements the {open_quotes}Conceptual Vehicle Design Report - Pure Fuel Cell Powertrain Vehicle{close_quotes} and includes a cost study of the fuel cell power system. The three classes of vehicles considered in this design and packaging exercise are the same vehicle classes that were studied in the previous report: the Aspire, representing the small vehicle class; the AIV (Aluminum Intensive Vehicle) Sable, representing the mid-size vehicle; and the E-150 Econoline, representing the van-size class. A preliminary PEM fuel cell power system manufacturing cost study is also presented. As in the case of the previous report concerning the {open_quotes}Pure Fuel Cell Powertrain Vehicle{close_quotes}, the same assumptions are made for the fuel cell power system. These assumptions are fuel cell system power densities of 0.33 kW/ka and 0.33 kW/l, platinum catalyst loading of less than or equal to 0.25 mg/cm{sup 2} total, and hydrogen tanks containing compressed gaseous hydrogen under 340 atm (5000 psia) pressure. The batteries considered for power augmentation of the fuel cell vehicle are based on the Ford Hybrid Electric Vehicle (HEV) program. These are state-of-the-art high power lead acid batteries with power densities ranging from 0.8 kW/kg to 2 kW/kg. The results reported here show that battery augmentation provides the fuel cell vehicle with a power source to meet instant high power demand for acceleration and start-up. Based on the assumptions made in this report, the packaging of the battery augmented fuel cell vehicle appears to be as feasible as the packaging of the pure fuel cell powered vehicle.

  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 transport characteristics of porous diffusion media in polymer electrolyte membrane fuel cells: A review

    Science.gov (United States)

    Liu, Xunliang; Peng, Fangyuan; Lou, Guofeng; Wen, Zhi

    2015-12-01

    Fundamental understanding of liquid water transport in gas diffusion media (GDM) is important to improve the material and structure design of polymer electrolyte membrane (PEM) fuel cells. Continuum methods of two-phase flow modeling facilitate to give more details of relevant information. The proper empirical correlations of liquid water transport properties, such as capillary characteristics, water relative permeability and effective contact angle, are crucial to two phase flow modeling and cell performance prediction. In this work, researches on these properties in the last decade are reviewed. Various efforts have been devoted to determine the water transport properties for GDMs. However, most of the experimental studies are ex-situ measurements. In-situ measurements for GDMs and extending techniques available to study the catalyst layer and the microporous layer will be further challenges. Using the Leverett-Udell correlation is not recommended for quantitative modeling. The reliable Leverett-type correlation for GDMs, with the inclusion of the cosine of effective contact angle, is desirable but hard to be established for modeling two-phase flow in GDMs. A comprehensive data set of liquid water transport properties is needed for various GDM materials under different PEM fuel cell operating conditions.

  16. Membrane techniques in the periphery of fuel cell powered vehicles; Membrantechnik im Peripheriebereich von Brennstoffzellenfahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Matthias, Carsten Herbert

    2009-07-01

    The publication intends to make a contribution to the advancement of mobile fuel cell systems and to outline the potential applications of membrane techniques. There are three different approaches: 1. Characterisation of membranes and design of membrane moisturizers for water management in low-temperature PEFC. 2. Use of metal membranes in a shift membrane reactor or a membrane/reformer unit for on-board hydrogen production in APU systems. 3. System modelling for assessing the potential of components involving membrane techniques as compared to alternative techniques. (orig.)

  17. A parametric study of assembly pressure, thermal expansion, and membrane swelling in PEM fuel cells

    Directory of Open Access Journals (Sweden)

    Maher A.R. Sadiq Al-Baghdadi

    2016-01-01

    Full Text Available Proton Exchange membrane (PEM fuel cells are still undergoing intense development, and the combination of new and optimized materials, improved product development, novel architectures, more efficient transport processes, and design optimization and integration are expected to lead to major gains in performance, efficiency, durability, reliability, manufacturability and cost-effectiveness. PEM fuel cell assembly pressure is known to cause large strains in the cell components. All components compression occurs during the assembly process of the cell, but also during fuel cell operation due to membrane swelling when absorbs water and cell materials expansion due to heat generating in catalyst layers. Additionally, the repetitive channel-rib pattern of the bipolar plates results in a highly inhomogeneous compressive load, so that while large strains are produced under the rib, the region under the channels remains approximately at its initial uncompressed state. This leads to significant spatial variations in GDL thickness and porosity distributions, as well as in electrical and thermal bulk conductivities and contact resistances (both at the ribe-GDL and membrane-GDL interfaces. These changes affect the rates of mass, charge, and heat transport through the GDL, thus impacting fuel cell performance and lifetime. In this paper, computational fluid dynamics (CFD model of a PEM fuel cell has been developed to simulate the pressure distribution inside the cell, which are occurring during fuel cell assembly (bolt assembling, and membrane swelling and cell materials expansion during fuel cell running due to the changes of temperature and relative humidity. The PEM fuel cell model simulated includes the following components; two bi-polar plates, two GDLs, and, an MEA (membrane plus two CLs. This model is used to study and analyses the effect of assembling and operating parameters on the mechanical behaviour of PEM. The analysis helped identifying critical

  18. Advances in the high performance polymer electrolyte membranes for fuel cells.

    Science.gov (United States)

    Zhang, Hongwei; Shen, Pei Kang

    2012-03-21

    This critical review tersely and concisely reviews the recent development of the polymer electrolyte membranes and the relationship between their properties and affecting factors like operation temperature. In the first section, the advantages and shortcomings of the corresponding polymer electrolyte membrane fuel cells are analyzed. Then, the limitations of Nafion membranes and their alternatives to large-scale commercial applications are discussed. Secondly, the concepts and approaches of the alternative proton exchange membranes for low temperature and high temperature fuel cells are described. The highlights of the current scientific achievements are given for various aspects of approaches. Thirdly, the progress of anion exchange membranes is presented. Finally, the perspectives of future trends on polymer electrolyte membranes for different applications are commented on (400 references).

  19. Structural characterization combined with the first principles simulations of barium/strontium cobaltite/ferrite as promising material for solid oxide fuel cells cathodes and high-temperature oxygen permeation membranes.

    Science.gov (United States)

    Gangopadhayay, Shruba; Inerbaev, Talgat; Masunov, Artëm E; Altilio, Deanna; Orlovskaya, Nina

    2009-07-01

    Mixed ionic-electronic conducting perovskite type oxides with a general formula ABO(3) (where A = Ba, Sr, Ca and B = Co, Fe, Mn) often have high mobility of the oxygen vacancies and exhibit strong ionic conductivity. They are key materials that find use in several energy related applications, including solid oxide fuel cell (SOFC), sensors, oxygen separation membranes, and catalysts. Barium/strontium cobaltite/ferrite (BSCF) Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-delta) was recently identified as a promising candidate for cathode material in intermediate temperature SOFCs. In this work, we perform experimental and theoretical study of the local atomic structure of BSFC. Micro-Raman spectroscopy was performed to characterize the vibrational properties of BSCF. The Jahn-Teller distortion of octahedral coordination around Co(4+) cations was observed experimentally and explained theoretically. Different cations and oxygen vacancies ordering are examined using plane wave pseudopotential density functional theory. We find that cations are completely disordered, whereas oxygen vacancies exhibit a strong trend for aggregation in L-shaped trimer and square tetramer structure. On the basis of our results, we suggest a new explanation for BSCF phase stability. Instead of linear vacancy ordering, which must take place before the phase transition into brownmillerite structure, the oxygen vacancies in BSCF prefer to form the finite clusters and preserve the disordered cubic structure. This structural feature could be found only in the first-principles simulations and can not be explained by the effect of the ionic radii alone.

  20. Low-cost polyvinyl alcohol hydrogel membrane electrolyte for PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, Y. [Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering

    2010-07-01

    This paper presented a newly developed polyvinyl alcohol (PVA) chemical hydrogel membrane electrolyte (PCHME) for use in proton exchange membrane (PEM) fuel cells. The method of PCHME preparation was described along with its properties. The membrane is much less expensive than the commonly used Nafion membrane. A direct borohydride fuel cell (DBFC) using a polyvinyl alcohol (PVA) chemical hydrogel membrane electrolyte and a nickel-based composite anode was assembled in order to test the performance of the new membrane. The cathode catalysts were carbon-supported platinum and sputtered gold. Oxygen, air, and acidified hydrogen peroxide were used as oxidants in the DBFC. Performance characteristics of the PCHME-based DBFC were obtained at different temperatures and compared with similar DBFCs using Nafion membrane electrolytes under the same operating conditions. The peak power density of the PCHME-based DBFC was somewhat higher than that of the Nafion membrane electrolyte based DBFC at 60 degrees C. The borohydride-oxygen fuel cell with PCHME yielded a maximum peak power density of 242 mW cm{sup -2} at 60 degrees C. It was concluded that the membrane presents an inexpensive alternative to widely used polymer membrane electrolytes.

  1. Low power proton exchange membrane fuel cell system identification and adaptive control

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yee-Pien; Wang, Fu-Cheng; Ma, Ying-Wei [Department of Mechanical Engineering, National Taiwan University, Taipei (Taiwan); Chang, Hsin-Ping; Weng, Biing-Jyh [Chung Shan Institute of Science and Technology (CSIST), Armaments Bureau, M.N.D. (Taiwan)

    2007-02-10

    This paper proposes a systematic method of system identification and control of a proton exchange membrane (PEM) fuel cell. This fuel cell can be used for low-power communication devices involving complex electrochemical reactions of nonlinear and time-varying dynamic properties. From a system point of view, the dynamic model of PEM fuel cell is reduced to a configuration of two inputs, hydrogen and air flow rates, and two outputs, cell voltage and current. The corresponding transfer functions describe linearized subsystem dynamics with finite orders and time-varying parameters, which are expressed as discrete-time auto-regression moving-average with auxiliary input models for system identification by the recursive least square algorithm. In the experiments, a pseudo-random binary sequence of hydrogen or air flow rate is fed to a single fuel cell device to excite its dynamics. By measuring the corresponding output signals, each subsystem transfer function of reduced order is identified, while the unmodeled, higher-order dynamics and disturbances are described by the auxiliary input term. This provides a basis of adaptive control strategy to improve the fuel cell performance in terms of efficiency, as well as transient and steady state specifications. Simulation shows that adaptive controller is robust to the variation of fuel cell system dynamics, and it has proved promising from the experimental results. (author)

  2. Parametric analysis of the proton exchange membrane fuel cell performance using design of experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Wei-Lung [School of Defense Science, Chung Cheng Institute of Technology, National Defense University, No. 190, Sanyuan 1st Street, Ta-Hsi, Taoyuan, Taiwan 335 (China); Wu, Sheng-Ju; Shiah, Sheau-Wen [Department of Power Vehicle and Systems Engineering, Chung Cheng Institute of Technology, National Defense University, No. 190, Sanyuan 1st Street, Ta-Hsi, Taoyuan, Taiwan 335 (China)

    2008-05-15

    Proton exchange membrane fuel cell (PEMFC) performance depends on different fuel cell operating temperatures, humidification temperatures, operating pressures, flow rates, and various combinations of these parameters. This study employed the method of the design of experiments (DOE) to obtain the optimal combination of the six primary operating parameters (fuel cell operating temperatures, operating pressures, anode and cathode humidification temperatures, anode and cathode stoichiometric flow ratios). In the first stage, this study adopted a 2{sup k-2} fractional factorial design of the DOE to determine whether these factors have significant effects on a response and the interactions between various parameters. Second, the L{sub 27}(3{sup 13}) orthogonal array of the Taguchi method is utilized to determine the optimal combination of factors for a fuel cell. Based on this study, the operating pressure, the operating temperature, and the interactions between operating temperature and operating pressure have a significant effect on the fuel cell performance. Among them, the operating pressure is the most important contributor. When the operating pressure increases, it should simultaneously lower the effects of other factors. While both the operating temperature and pressure increase simultaneously with that, the other factors are at appropriate conditions, it is possible to improve the fuel cell performance. (author)

  3. Low power proton exchange membrane fuel cell system identification and adaptive control

    Science.gov (United States)

    Yang, Yee-Pien; Wang, Fu-Cheng; Chang, Hsin-Ping; Ma, Ying-Wei; Weng, Biing-Jyh

    This paper proposes a systematic method of system identification and control of a proton exchange membrane (PEM) fuel cell. This fuel cell can be used for low-power communication devices involving complex electrochemical reactions of nonlinear and time-varying dynamic properties. From a system point of view, the dynamic model of PEM fuel cell is reduced to a configuration of two inputs, hydrogen and air flow rates, and two outputs, cell voltage and current. The corresponding transfer functions describe linearized subsystem dynamics with finite orders and time-varying parameters, which are expressed as discrete-time auto-regression moving-average with auxiliary input models for system identification by the recursive least square algorithm. In the experiments, a pseudo-random binary sequence of hydrogen or air flow rate is fed to a single fuel cell device to excite its dynamics. By measuring the corresponding output signals, each subsystem transfer function of reduced order is identified, while the unmodeled, higher-order dynamics and disturbances are described by the auxiliary input term. This provides a basis of adaptive control strategy to improve the fuel cell performance in terms of efficiency, as well as transient and steady state specifications. Simulation shows that adaptive controller is robust to the variation of fuel cell system dynamics, and it has proved promising from the experimental results.

  4. Operation of polymer electrolyte membrane fuel cells with dry feeds: Design and operating strategies

    Science.gov (United States)

    Hogarth, Warren H. J.; Benziger, Jay B.

    The operation of polymer electrolyte membrane fuel cells (PEMFCs) with dry feeds has been examined with different fuel cell flow channel designs as functions of pressure, temperature and flow rate. Auto-humidified (or self-humidifying) PEMFC operation is improved at higher pressures and low gas velocities where axial dispersion enhances "back-mixing" of the product water with the dry feed. We demonstrate auto-humidified operation of the channel-less, self-draining fuel cell, based on a stirred tank reactor; data is presented showing auto-humidified operation from 25 to 115 °C at 1 and 3 atm. Design and operating requirements are derived for the auto-humidified operation of the channel-less, self-draining fuel cell. The auto-humidified self-draining fuel cell outperforms a fully humidified serpentine flow channel fuel cell at high current densities. The new design offers substantial benefits for simplicity of operation and control including: the ability to self-drain reducing flooding, the ability to uniformly disperse water removing current gradients and the ability to operate on dry feeds eliminating the need for humidifiers. Additionally, the design lends itself well to a modular design concept.

  5. Plasma Membranes Modified by Plasma Treatment or Deposition as Solid Electrolytes for Potential Application in Solid Alkaline Fuel Cells

    OpenAIRE

    Christophe Coutanceau; Marc Reinholdt; Jean Durand; Valérie Flaud; Serguei Martemianov; Alina Ilie; Eric Beche; Stéphanie Roualdès; Mauricio Schieda; Jérémy Frugier

    2012-01-01

    In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, com...

  6. Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications: Conceptual vehicle design report pure fuel cell powertrain vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Oei, D.; Kinnelly, A.; Sims, R.; Sulek, M.; Wernette, D.

    1997-02-01

    In partial fulfillment of the Department of Energy (DOE) Contract No. DE-AC02-94CE50389, {open_quotes}Direct-Hydrogen-Fueled Proton-Exchange-Membrane (PEM) Fuel Cell for Transportation Applications{close_quotes}, this preliminary report addresses the conceptual design and packaging of a fuel cell-only powered vehicle. Three classes of vehicles are considered in this design and packaging exercise, the Aspire representing the small vehicle class, the Taurus or Aluminum Intensive Vehicle (AIV) Sable representing the mid-size vehicle and the E-150 Econoline representing the van-size class. A fuel cell system spreadsheet model and Ford`s Corporate Vehicle Simulation Program (CVSP) were utilized to determine the size and the weight of the fuel cell required to power a particular size vehicle. The fuel cell power system must meet the required performance criteria for each vehicle. In this vehicle design and packaging exercise, the following assumptions were made: fuel cell power system density of 0.33 kW/kg and 0.33 kg/liter, platinum catalyst loading less than or equal to 0.25 mg/cm{sup 2} total and hydrogen tanks containing gaseous hydrogen under 340 atm (5000 psia) pressure. The fuel cell power system includes gas conditioning, thermal management, humidity control, and blowers or compressors, where appropriate. This conceptual design of a fuel cell-only powered vehicle will help in the determination of the propulsion system requirements for a vehicle powered by a PEMFC engine in lieu of the internal combustion (IC) engine. Only basic performance level requirements are considered for the three classes of vehicles in this report. Each vehicle will contain one or more hydrogen storage tanks and hydrogen fuel for 560 km (350 mi) driving range. Under these circumstances, the packaging of a fuel cell-only powered vehicle is increasingly difficult as the vehicle size diminishes.

  7. High surface area graphite as alternative support for proton exchange membrane fuel cell catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira-Aparicio, P.; Folgado, M.A. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avda. Complutense 22, E-28040 Madrid (Spain); Daza, L. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avda. Complutense 22, E-28040 Madrid (Spain); Instituto de Catalisis y Petroleoquimica (CSIC), C/Marie Curie, 2 Campus de Cantoblanco, E-28049 Madrid (Spain)

    2009-07-01

    The suitability of a high surface area graphite (HSAG) as proton exchange membrane fuel cell (PEMFC) catalyst support has been evaluated and compared with that of the most popular carbon black: the Vulcan XC72. It has been observed that Pt is arranged on the graphite surface resulting in different structures which depend on the catalysts synthesis conditions. The influence that the metal particle size and the metal-support interaction exert on the catalysts degradation rate is analyzed. Temperature programmed oxidation (TPO) under oxygen containing streams has been shown to be a useful method to assess the resistance of PEMFC catalysts to carbon corrosion. The synthesized Pt/HSAG catalysts have been evaluated in single cell tests in the cathode catalytic layer. The obtained results show that HSAG can be a promising alternative to the traditionally used Vulcan XC72 carbon black when suitable catalysts synthesis conditions are used. (author)

  8. Characterization of PEM fuel cell membrane-electrode-assemblies by electrochemical methods and microanalysis

    Energy Technology Data Exchange (ETDEWEB)

    Borup, R.L.; Vanderborgh, N.E.

    1995-05-01

    Hydrogen adsorption/desorption and CO oxidation are used to evaluate the active Pt surface area of fuel cell membrane electrode assemblies. The membrane electrode assemblies are evaluated for useful catalyst life and are examined for relative CO and CO{sub 2} tolerance. The electrochemical measurements combined with microanalysis of membrane electrode assemblies, including SEM and EDS allow a greater understanding and optimization of process variables.

  9. 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.

  10. Harvesting energy of interaction between bacteria and bacteriophage in a membrane-less fuel cell.

    Science.gov (United States)

    Gupta, Ragini; Bekele, Wasihun; Ghatak, Animangsu

    2013-11-01

    When a fuel and oxidant flow in laminar contact through a micro-fluidic channel, a sharp interface appears between the two liquids, which eliminate the need of a proton exchange membrane. This principle has been used to generate potential in a membrane-less fuel cell. This study use such a cell to harvest energy of interaction between a bacteria having negative charge on its surface and a bacteriophage with positive and negative charges on its tail and head, respectively. When Klebsiella pneumoniae (Kp6) and phage (P-Kp6) are pumped through a fuel cell fitted with two copper electrodes placed at its two sides, interaction between these two charged species at the interface results in a constant open circuit potential which varies with concentration of charged species but gets generated for both specific and non-specific bacteria and phage system. Oxygenation of bacteria or phage however diminishes the potential unlike in conventional microbial fuel cells.

  11. Predictive model of transport properties of fuel cell membrane : from microscopic to macroscopic level

    Energy Technology Data Exchange (ETDEWEB)

    Colinart, T.; Lottin, O.; Maranzana, G.; Didierjean, S.; Moyne, C. [Nancy-Univ., Vandoeuvre-les-Nancy (France). Laboratoire d' Energetique et de Mecanique Theorique et Appliquee

    2007-07-01

    Because of their attractiveness as efficient and clean energy producers, proton exchange membrane fuel cells (PEMFC) can be used in automotive and small stationary applications. The electrochemical reaction takes place on two electrodes separated by a ionomer membrane. An important component of fuel cell water management and a problem for fuel cell performances involves the transport of protons from the anode to the cathode as its' transport properties are highly water dependent. Nafion membranes are widely used as an electrolyte for PEMFC. This paper presented a model to predict transport properties of polymer membranes such as Nafion used as electrolytes in a low temperature fuel cell. The paper discussed the electrical double layer that was used to determine surface charge density. The paper then discussed the analytical solution to the physical problem in the diffuse part of a cylindrical pore which involved solving the Poisson-Boltzmann, the Navier-Stokes and the Nernst-Planck equations. The properties of the electrolytic solution were equal to those of water and they were considered to be constant within the pore. A literature comparison with other models was also presented. It was concluded that in order to supplement the model, it is necessary to investigate the mechanics of the membrane, particularly the swelling behaviour, and the adsorption phenomena of the ions in the stern layer. 15 refs., 1 tab., 3 figs.

  12. Carbon nanotubes based nafion composite membranes for fuel cell applications

    CSIR Research Space (South Africa)

    Cele, NP

    2009-01-01

    Full Text Available surface oxidation as well as functionalisation in composite membranes was investigated by focussing on three aspects: thermo-mechanical stability, thermal degradation and proton conductivity. The oCNTs-containing Nafion composite membrane exhibited...

  13. Water Management Membrane for Fuel Cells and Electrolyzers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of an improved water management membrane for a static vapor feed electrolyzer that produces sub-saturated H2 and O2 is proposed. This improved membrane...

  14. Dimensionally-stable phosphoric acid-doped polybenzimidazoles for high-temperature proton exchange membrane fuel cells

    Science.gov (United States)

    Li, Xiaobai; Ma, Hongwei; Shen, Yanchao; Hu, Wei; Jiang, Zhenhua; Liu, Baijun; Guiver, Michael D.

    2016-12-01

    Phosphoric acid-doped polybenzimidazole (PA-m-PBI) membranes are widely investigated for high temperature proton exchange membrane fuel cells because of their low cost and high performance. For this system, a major challenge is in achieving a good compromise between the phosphoric acid doping level and the membrane dimensional-mechanical stability. Different from the established PA-m-PBI system, the present work investigates two types of PA-PBI membranes incorporating flexible ether linkages and asymmetric bulky pendants (phenyl and methylphenyl), which exhibit much better dimensional-mechanical stability after immersing in PA solution, even at high temperature for an extended period. This superior stability allowed higher acid doping levels (20.6 and 24.6) to be achieved, thus increasing proton conductivity (165 and 217 mS cm-1 at 200 °C under anhydrous conditions) as well as significantly improving fuel cell performance. The peak power densities in hydrogen/air fuel cell were 279 and 320 mW cm-2 at 160 °C, without humidification. Molecular simulation, density and fractional free volume, and wide-angle X-ray diffraction were used to investigate their structure-property relationships.

  15. Block Copolymers for Alkaline Fuel Cell Membrane Materials

    Science.gov (United States)

    2014-07-30

    constitute the ionic conducting channel while the hydrophobic perfluorinated backbone forms the mechanical component of the membrane material. Although...membrane in many aspects and design optimized anion exchange membranes with better alkaline stability, mechanical integrity and ionic conductivity. A...high ionic conductivity through formation of phase separated ionic domains. Using anionic polymerization, a polyethylene based block copolymer was

  16. Activity targets for nanostructured platinum-group-metal-free catalysts in hydroxide exchange membrane fuel cells

    Science.gov (United States)

    Setzler, Brian P.; Zhuang, Zhongbin; Wittkopf, Jarrid A.; Yan, Yushan

    2016-12-01

    Fuel cells are the zero-emission automotive power source that best preserves the advantages of gasoline automobiles: low upfront cost, long driving range and fast refuelling. To make fuel-cell cars a reality, the US Department of Energy has set a fuel cell system cost target of US$30 kW-1 in the long-term, which equates to US$2,400 per vehicle, excluding several major powertrain components (in comparison, a basic, but complete, internal combustion engine system costs approximately US$3,000). To date, most research for automotive applications has focused on proton exchange membrane fuel cells (PEMFCs), because these systems have demonstrated the highest power density. Recently, however, an alternative technology, hydroxide exchange membrane fuel cells (HEMFCs), has gained significant attention, because of the possibility to use stable platinum-group-metal-free catalysts, with inherent, long-term cost advantages. In this Perspective, we discuss the cost profile of PEMFCs and the advantages offered by HEMFCs. In particular, we discuss catalyst development needs for HEMFCs and set catalyst activity targets to achieve performance parity with state-of-the-art automotive PEMFCs. Meeting these targets requires careful optimization of nanostructures to pack high surface areas into a small volume, while maintaining high area-specific activity and favourable pore-transport properties.

  17. Activity targets for nanostructured platinum-group-metal-free catalysts in hydroxide exchange membrane fuel cells.

    Science.gov (United States)

    Setzler, Brian P; Zhuang, Zhongbin; Wittkopf, Jarrid A; Yan, Yushan

    2016-12-06

    Fuel cells are the zero-emission automotive power source that best preserves the advantages of gasoline automobiles: low upfront cost, long driving range and fast refuelling. To make fuel-cell cars a reality, the US Department of Energy has set a fuel cell system cost target of US$30 kW(-1) in the long-term, which equates to US$2,400 per vehicle, excluding several major powertrain components (in comparison, a basic, but complete, internal combustion engine system costs approximately US$3,000). To date, most research for automotive applications has focused on proton exchange membrane fuel cells (PEMFCs), because these systems have demonstrated the highest power density. Recently, however, an alternative technology, hydroxide exchange membrane fuel cells (HEMFCs), has gained significant attention, because of the possibility to use stable platinum-group-metal-free catalysts, with inherent, long-term cost advantages. In this Perspective, we discuss the cost profile of PEMFCs and the advantages offered by HEMFCs. In particular, we discuss catalyst development needs for HEMFCs and set catalyst activity targets to achieve performance parity with state-of-the-art automotive PEMFCs. Meeting these targets requires careful optimization of nanostructures to pack high surface areas into a small volume, while maintaining high area-specific activity and favourable pore-transport properties.

  18. Preparation and analysis of new proton conducting membranes for fuel cells

    DEFF Research Database (Denmark)

    Lund, Peter Brilner

    2007-01-01

    A range of potential new fuel cell membranes were prepared by inserting zirconium phosphate (ZrP) into divinylbenzene (DVB) crosslinked, sulfonated, polystyrene grafted poly(ethylene-alt-tetrafluoroethylene) and poly(vinyl difluoride) membranes using an ion exchange procedure. In short, the prefo......A range of potential new fuel cell membranes were prepared by inserting zirconium phosphate (ZrP) into divinylbenzene (DVB) crosslinked, sulfonated, polystyrene grafted poly(ethylene-alt-tetrafluoroethylene) and poly(vinyl difluoride) membranes using an ion exchange procedure. In short....... Additional zirconium phosphate treatment resulted in composite ETFE samples containing up to 15 wt.% ZrP and composite PVdF samples containing up to 27 wt.%. TG analyses of the ETFE-g-PSSA and PVdF-g-PSSA composite membranes indicated no significant changes of the thermal stability in comparison...

  19. High temperature proton exchange membranes based on polybenzimidazole and clay composites for fuel cells

    DEFF Research Database (Denmark)

    Plackett, David; Siu, Ana; Li, Qingfeng

    2011-01-01

    and pyridinium salts with varying polarity and hydrogen-bonding capacity. Clay modification by ion-exchange reactions involving replacement of interlayer inorganic cations was confirmed using X-ray photoelectron and infrared spectroscopy techniques. The cast PBI membranes were characterized by their water uptake......, acid doping and swelling, tensile strength, conductivity and hydrogen permeability as well as by fuel cell tests. For the composite membranes, high acid doping levels were achieved with sufficient mechanical strength and improved dimensional stability or reduced membrane swelling. At an acid doping......-doped pristine PBI membranes. In accordance with the hydrogen permeability measurements, fuel cell tests exhibited high open circuit voltages (i.e., 1.02 V) at room temperature as well as high I–V performance compared with normal PBI membranes....

  20. 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

    A previously published computational multi-phase model of a polymer-electrolyte membrane fuel cell cathode 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 hum...

  1. The reasons for the high power density of fuel cells fabricated with directly deposited membranes

    Science.gov (United States)

    Vierrath, Severin; Breitwieser, Matthias; Klingele, Matthias; Britton, Benjamin; Holdcroft, Steven; Zengerle, Roland; Thiele, Simon

    2016-09-01

    In a previous study, we reported that polymer electrolyte fuel cells prepared by direct membrane deposition (DMD) produced power densities in excess of 4 W/cm2. In this study, the underlying origins that give rise to these high power densities are investigated and reported. The membranes of high power, DMD-fabricated fuel cells are relatively thin (12 μm) compared to typical benchmark, commercially available membranes. Electrochemical impedance spectroscopy, at high current densities (2.2 A/cm2) reveals that mass transport resistance was half that of reference, catalyst-coated-membranes (CCM). This is attributed to an improved oxygen supply in the cathode catalyst layer by way of a reduced propensity of flooding, and which is facilitated by an enhancement in the back diffusion of water from cathode to anode through the thin directly deposited membrane. DMD-fabricated membrane-electrode-assemblies possess 50% reduction in ionic resistance (15 mΩcm2) compared to conventional CCMs, with contributions of 9 mΩcm2 for the membrane resistance and 6 mΩcm2 for the contact resistance of the membrane and catalyst layer ionomer. The improved mass transport is responsible for 90% of the increase in power density of the DMD fuel cell, while the reduced ionic resistance accounts for a 10% of the improvement.

  2. Electrospun Nafion®/Polyphenylsulfone Composite Membranes for Regenerative Hydrogen Bromine Fuel Cells

    Directory of Open Access Journals (Sweden)

    Jun Woo Park

    2016-02-01

    Full Text Available The regenerative H2/Br2-HBr fuel cell, utilizing an oxidant solution of Br2 in aqueous HBr, shows a number of benefits for grid-scale electricity storage. The membrane-electrode assembly, a key component of a fuel cell, contains a proton-conducting membrane, typically based on the perfluorosulfonic acid (PFSA ionomer. Unfortunately, the high cost of PFSA membranes and their relatively high bromine crossover are serious drawbacks. Nanofiber composite membranes can overcome these limitations. In this work, composite membranes were prepared from electrospun dual-fiber mats containing Nafion® PFSA ionomer for facile proton transport and an uncharged polymer, polyphenylsulfone (PPSU, for mechanical reinforcement, and swelling control. After electrospinning, Nafion/PPSU mats were converted into composite membranes by softening the PPSU fibers, through exposure to chloroform vapor, thus filling the voids between ionomer nanofibers. It was demonstrated that the relative membrane selectivity, referenced to Nafion® 115, increased with increasing PPSU content, e.g., a selectivity of 11 at 25 vol% of Nafion fibers. H2-Br2 fuel cell power output with a 65 μm thick membrane containing 55 vol% Nafion fibers was somewhat better than that of a 150 μm Nafion® 115 reference, but its cost advantage due to a four-fold decrease in PFSA content and a lower bromine species crossover make it an attractive candidate for use in H2/Br2-HBr systems.

  3. Electrospun Nafion(®)/Polyphenylsulfone Composite Membranes for Regenerative Hydrogen Bromine Fuel Cells.

    Science.gov (United States)

    Park, Jun Woo; Wycisk, Ryszard; Pintauro, Peter N; Yarlagadda, Venkata; Van Nguyen, Trung

    2016-02-29

    The regenerative H₂/Br₂-HBr fuel cell, utilizing an oxidant solution of Br₂ in aqueous HBr, shows a number of benefits for grid-scale electricity storage. The membrane-electrode assembly, a key component of a fuel cell, contains a proton-conducting membrane, typically based on the perfluorosulfonic acid (PFSA) ionomer. Unfortunately, the high cost of PFSA membranes and their relatively high bromine crossover are serious drawbacks. Nanofiber composite membranes can overcome these limitations. In this work, composite membranes were prepared from electrospun dual-fiber mats containing Nafion(®) PFSA ionomer for facile proton transport and an uncharged polymer, polyphenylsulfone (PPSU), for mechanical reinforcement, and swelling control. After electrospinning, Nafion/PPSU mats were converted into composite membranes by softening the PPSU fibers, through exposure to chloroform vapor, thus filling the voids between ionomer nanofibers. It was demonstrated that the relative membrane selectivity, referenced to Nafion(®) 115, increased with increasing PPSU content, e.g., a selectivity of 11 at 25 vol% of Nafion fibers. H₂-Br₂ fuel cell power output with a 65 μm thick membrane containing 55 vol% Nafion fibers was somewhat better than that of a 150 μm Nafion(®) 115 reference, but its cost advantage due to a four-fold decrease in PFSA content and a lower bromine species crossover make it an attractive candidate for use in H₂/Br₂-HBr systems.

  4. 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 el...

  5. In situ formation of leak-free polyethylene glycol (PEG) membranes in microfluidic fuel cells.

    Science.gov (United States)

    Ho, W F; Lim, K M; Yang, K-L

    2016-11-29

    Membraneless microfluidic fuel cells operated under two co-laminar flows often face serious fuel cross-over problems, especially when flow rates are close to zero. In this study, we show that polyethylene glycol (PEG) monomers can be cross-linked inside microfluidic channels to form leak-free PEG membranes, which prevent mixing of two incompatible electrolyte solutions while allowing diffusion of certain molecules (e.g. glucose) and ions. By using PEG monomers of different molecular weights and cross-linking conditions, we are able to tailor selectivity of the membrane to allow passage of glucose while blocking larger molecules such as trypan blue. As a proof of principle, a microfluidic fuel cell with a PEG membrane and two incompatible electrolytes (acid and base) is demonstrated. Thanks to the leak-free nature of the PEG membrane, these two electrolytes do not mix together even at very slow flow rates. This microfluidic fuel cell is able to generate a voltage up to ∼450 mV from 10 mM of glucose with a flow rate of 20 μL min(-1). This microfluidic fuel cell is potentially useful as a miniature power source for many applications.

  6. Dynamic Thermal Model and Temperature Control of Proton Exchange Membrane Fuel Cell Stack

    Institute of Scientific and Technical Information of China (English)

    邵庆龙; 卫东; 曹广益; 朱新坚

    2005-01-01

    A dynamic thermal transfer model of a proton exchange membrane fuel cell (PEMFC) stack is developed based on energy conservation in order to reach better temperature control of PEMFC stack. Considering its uncertain parameters and disturbance, we propose a robust adaptive controller based on backstepping algorithm of Lyaponov function. Numerical simulations indicate the validity of the proposed controller.

  7. Rate-determining steps in fuel cells with ion exchange membranes

    NARCIS (Netherlands)

    Duin, P.J. van; Kruissink, C.A.

    1967-01-01

    It has been shown by impedance measurements that over a large range of potentials the current at the oxygen electrode of hydrogen-oxygen ion exchange membrane fuel cells is controlled by a charge tra11sfer reaction. The frequency range used covered six decades.

  8. 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...

  9. Multiphase Simulations and Design of Validation Experiments for Proton Exchange Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Berning, Torsten

    2013-01-01

    Proton exchange membrane fuel cells directly convert into electricity the chemical energy of hydrogen and oxygen from air. The by-products are just water and waste heat. Depending on the operating conditions the water may be in the liquid or gas phase, and liquid water can hence plug the porous m...

  10. Particle Swarm Optimization based predictive control of Proton Exchange Membrane Fuel Cell (PEMFC)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Proton Exchange Membrane Fuel Cells (PEMFCs) are the main focus of their current development as power sources because they are capable of higher power density and faster start-up than other fuel cells. The humidification system and output performance of PEMFC stack are briefly analyzed. Predictive control of PEMFC based on Support Vector Regression Machine (SVRM) is presented and the SVRM is constructed. The processing plant is modelled on SVRM and the predictive control law is obtained by using Particle Swarm Optimization (PSO). The simulation and the results showed that the SVRM and the PSO receding optimization applied to the PEMFC predictive control yielded good performance.

  11. Dynamic Model of the High Temperature Proton Exchange Membrane Fuel Cell Stack Temperature

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2009-01-01

    consists of a prototype cathode air cooled 30 cell HTPEM fuel cell stack developed at the Institute of Energy Technology at Aalborg University. This fuel cell stack uses PEMEAS Celtec P-1000 membranes and runs on pure hydrogen in a dead-end anode configuration with a purge valve. The cooling of the stack...... elements for start-up, heat conduction through stack insulation, cathode air convection, and heating of the inlet gases in the manifold. Various measurements are presented to validate the model predictions of the stack temperatures....

  12. Development of a Direct Ethanol Fuel Cell System with Anion Exchange Membranes

    Science.gov (United States)

    2015-01-15

    Fuel Cell System with Anion Exchange Membranes Report Title Based on the Phase I research results, we identified that carbon supported Pd-based catalysts...Report 22-0ct-2012- 21-Jan-2013 4. 1ITLE AND SUBTITLE 5a CONTRACT NUMBER Development of a Direct Ethanol Fuel Cell System with Anion Exchange...14. ABSTRACT Based on the Phase I research results, we identified that carbon supported Pd-based catalysts, such as Pd/C and PdRu!C, had better

  13. Continual Energy Management System of Proton Exchange Membrane Fuel Cell Hybrid Power Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Ren Yuan

    2016-01-01

    Full Text Available Current research status in energy management of Proton Exchange Membrane (PEM fuel cell hybrid power electric vehicles are first described in this paper, and then build the PEMFC/ lithium-ion battery/ ultra-capacitor hybrid system model. The paper analysis the key factors of the continuous power available in PEM fuel cell hybrid power electric vehicle and hybrid power system working status under different driving modes. In the end this paper gives the working flow chart of the hybrid power system and concludes the three items of the system performance analysis.

  14. Hierarchy carbon paper for the gas diffusion layer of proton exchange membrane fuel cells

    Science.gov (United States)

    Du, Chunyu; Wang, Baorong; Cheng, Xinqun

    This communication described the fabrication of a hierarchy carbon paper, and its application to the gas diffusion layer (GDL) of proton exchange membrane (PEM) fuel cells. The carbon paper was fabricated by growing carbon nanotubes (CNTs) on carbon fibers via covalently assembling metal nanocatalysts. Surface morphology observation revealed a highly uniform distribution of hydrophobic materials within the carbon paper. The contact angle to water of this carbon paper was not only very large but also particularly even. Polarization measurements verified that the hierarchy carbon paper facilitated the self-humidifying of PEM fuel cells, which could be mainly attributed to its higher hydrophobic property as diagnosed by electrochemical impedance spectroscopy (EIS).

  15. Improved Electrodes for High Temperature Proton Exchange Membrane Fuel Cells using Carbon Nanospheres.

    Science.gov (United States)

    Zamora, Héctor; Plaza, Jorge; Cañizares, Pablo; Lobato, Justo; Rodrigo, Manuel A

    2016-05-23

    This work evaluates the use of carbon nanospheres (CNS) in microporous layers (MPL) of high temperature proton exchange membrane fuel cell (HT-PEMFC) electrodes and compares the characteristics and performance with those obtained using conventional MPL based on carbon black. XRD, hydrophobicity, Brunauer-Emmett-Teller theory, and gas permeability of MPL prepared with CNS were the parameters evaluated. In addition, a short life test in a fuel cell was carried out to evaluate performance under accelerated stress conditions. The results demonstrate that CNS is a promising alternative to traditional carbonaceous materials because of its high electrochemical stability and good electrical conductivity, suitable to be used in this technology.

  16. Computational modeling study on polymer electrolyte membranes for fuel cell applications

    Science.gov (United States)

    Choe, Yoong-Kee; Tsuchida, Eiji

    2016-12-01

    Properties of polymer electrolyte membranes (PEMs) for use in polymer electrolyte membrane fuel cells (PEFCs) were investigated using the first-principles molecular dynamics simulations. One important issue in PEMs is how to improve the proton conductivity of PEMs under low hydration conditions. Results of the simulation show that perfluorinated type membranes such as Nafion exhibit excellent hydrophilic/hydrophobic phase separation while a hydrocarbon membrane has a relatively poor phase separation property. We found that such a poor phase separation behavior of a hydrocarbon membrane arise from hydrophilic functional groups attached to the PEMs.

  17. A PEM fuel cell based on electrocatalyst and membrane materials modified by PANAM dendrimers

    Energy Technology Data Exchange (ETDEWEB)

    Ledesma-Garcia, J.; Chapman, T.W.; Godinez, L.A. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Queretaro (Mexico)

    2008-10-15

    Due to its high energy conversion efficiency and low emission of pollutants, fuel-cell technology has been generally recognized as a key twenty-first century energy source. For polymer electrolyte membrane fuel cells (PEMFC), it has been found that platinum and its alloys exhibit the best electrocatalytic activity for oxygen reduction. The highest electrocatalytic activity of platinum and its alloys can be achieved when the particles are produced in the nanometer range. In this context, organic molecules have been adopted as templates to control the size of metal nanoparticles. Dendrimers, in particular, have shown promising properties for this application, and strategies that include direct adsorption, electrostatic attachment and covalent bonding have been developed for connecting metal-bearing dendrimers to conducting substrates. This paper reported on the preliminary results of a study that involved the construction and testing of a hydrogen-oxygen PEM fuel cell based on carbon-fiber-paper electrodes coated with hydroxyl-terminated dendrimers that encapsulated nanoparticles of platinum. This prototype cell also employed an ion exchange membrane comprising a cellulose acetate filter functionalized with proton-exchanging dendrimers. A proton-exchange membrane was prepared by binding duplex amine-carboxylate dendrimers to a cellulose-acetate support. With these dendrimer-based materials, a hydrogen-oxygen fuel cell was assembled and the performance compared with cells prepared with Nafion-based membranes. The voltage-current profiles and the power-density curves from the new cell provide encouragement to continue work with these dendrimer-modified materials. The paper discussed the experimental methods, with particular reference to materials; electrode preparation and characterization; proton-exchange membrane preparation; and PEM fuel-cell assembly and testing. It was concluded that the use of the dendritic macromolecules as supports for the nanoparticulate

  18. Model-Based Design of Energy Efficient Palladium Membrane Water Gas Shift Fuel Processors for PEM Fuel Cell Power Plants

    Science.gov (United States)

    Gummalla, Mallika; Vanderspurt, Thomas Henry; Emerson, Sean; She, Ying; Dardas, Zissis; Olsommer, Benoît

    An integrated, palladium alloy membrane Water-Gas Shift (WGS) reactor can significantly reduce the size, cost and complexity of a fuel processor for a Polymer Electrolyte Membrane fuel cell power system.

  19. Membranes for hydrogen and fuel cell technology; Membranas para celula combustivel e separacao de hidrogenio

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Suzana Pereira [GKSS-Forschungszentrum, Geesthacht (Germany)]. E-mail: nunes@gkss.de

    2005-07-01

    Membranes for fuel cell were prepared using as polymer matrix sulfonated polyether ketones. New sulfonated copolymers (poly oxazoles, poly imides and poly ketones) were synthesized. Nano composites using zirconium oxide and phosphates, as well as modified silicates were obtained aiming the application on direct methanol fuel cell (DMFC). The performances of membranes containing fillers with different aspects (spherical, layers, tubular, networks) and surface modification (hydroxy, imidazole, acid oligomers) were compared. The effect of surface modification was much more pronounced than that of the aspect. A good balance of proton conductivity and methanol permeability was obtained with silicates modified with imidazole groups. Good performance in DMFC were obtained with membranes containing zirconium phosphate. Acid oligomers also led to particularly high conductivity values above 100 deg C. Polyimide membranes with H{sub 2}/CH{sub 4} larger than 100 were obtained. (author )

  20. Non-isothermal two-phase transport in the polymer electrolyte membrane fuel cell microporous layer

    Science.gov (United States)

    Ge, Nan

    This thesis investigates the water transport mechanisms in the crack-free microporous layer (MPL) of a polymer electrolyte membrane (PEM) fuel cell. Synchrotron X-ray radiography was used to visualize and quantify the in situ liquid water in the gas diffusion layers (GDLs) of an operating fuel cell. A methodology was developed to correct the artefact of imaging sample movement. Furthermore, to address inaccuracies due to the scattering effect and higher harmonics at the synchrotron beamline, a calibration technique was introduced in order to experimentally determine the liquid water X-ray attenuation coefficient. Through in situ radiography, liquid water breakthrough events were observed in the MPL, and measured water thicknesses were used as inputs into a one-dimensional (1D) heat and mass transport model. The 1D model was used to describe the coupled relationship between liquid and vapour transport through the cathode MPL and the temperature distributions in the operating fuel cell.

  1. Issues associated with modelling of proton exchange membrane fuel cell by computational fluid dynamics

    Science.gov (United States)

    Bednarek, Tomasz; Tsotridis, Georgios

    2017-03-01

    The objective of the current study is to highlight possible limitations and difficulties associated with Computational Fluid Dynamics in PEM single fuel cell modelling. It is shown that an appropriate convergence methodology should be applied for steady-state solutions, due to inherent numerical instabilities. A single channel fuel cell model has been taken as numerical example. Results are evaluated for quantitative as well qualitative points of view. The contribution to the polarization curve of the different fuel cell components such as bi-polar plates, gas diffusion layers, catalyst layers and membrane was investigated via their effects on the overpotentials. Furthermore, the potential losses corresponding to reaction kinetics, due to ohmic and mas transport limitations and the effect of the exchange current density and open circuit voltage, were also investigated. It is highlighted that the lack of reliable and robust input data is one of the issues for obtaining accurate results.

  2. An non-uniformity voltage model for proton exchange membrane fuel cell

    Science.gov (United States)

    Li, Kelei; Li, Yankun; Liu, Jiawei; Guo, Ai

    2017-01-01

    The fuel cell used in transportation has environmental protection, high efficiency and no line traction power system which can greatly reduce line construction investment. That makes it a huge potential. The voltage uniformity is one of the most important factors affecting the operation life of proton exchange membrane fuel cell (PEMFC). On the basis of principle and classical model of the PEMFC, single cell voltage is calculated and the location coefficients are introduced so as to establish a non-uniformity voltage model. These coefficients are estimated with the experimental datum at stack current 50 A. The model is validated respectively with datum at 60 A and 100 A. The results show that the model reflects the basic characteristics of voltage non-uniformity and provides the beneficial reference for fuel cell control and single cell voltage detection.

  3. Small proton exchange membrane fuel cell power station by using bio-hydrogen

    Institute of Scientific and Technical Information of China (English)

    刘志祥; 毛宗强; 王诚; 任南琪

    2006-01-01

    In fermentative organic waste water treatment process, there was hydrogen as a by-product. After some purification,there was about 50% ~ 70% hydrogen in the bio-gas, which could be utilized for electricity generation with fuel cell. Half a year ago, joint experiments between biological hydrogen production in Harbin Institute of Technology (HIT) and proton exchange membrane fuel cell (PEMFC) power station in Tsinghua University were conducted for electricity generation with bio-hydrogen from the pilot plant in HIT. The results proved the feasibility of the bio-hydrogen as a by-product utilization with PEMFC power station and revealed some problems of fuel cell power station for this application.

  4. The direct formate fuel cell with an alkaline anion exchange membrane

    Science.gov (United States)

    Bartrom, Amy M.; Haan, John L.

    2012-09-01

    We demonstrate for the first time an operating Direct Formate Fuel Cell employing formate salts as the anode fuel, air or oxygen as the oxidant, a polymer anion exchange membrane, and metal catalysts at the anode and cathode. Operation of the DFFC at 60 °C using 1 M KOOCH and 2 M KOH as the anode fuel and electrolyte and oxygen gas at the cathode produces 144 mW cm-2 of peak power density, 181 mA cm-2 current density at 0.6 V, and an open circuit voltage of 0.931 V. This performance is competitive with alkaline Direct Liquid Fuel Cells (DLFCs) previously reported in the literature and demonstrates that formate fuel is a legitimate contender with alcohol fuels for alkaline DLFCs. A survey of the literature shows that a formate-oxygen fuel cell has a high theoretical potential, and the safe, renewable formate fuel does not poison the anode catalyst.

  5. Alkaline anion exchange membrane fuel cells for cogeneration of electricity and valuable chemicals

    Science.gov (United States)

    Pan, Z. F.; Chen, R.; An, L.; Li, Y. S.

    2017-10-01

    Alkaline anion exchange membrane fuel cells (AAEMFCs) have received ever-increasing attentions due to the enhanced electrochemical kinetics and the absence of precious metal electrocatalysts, and thus great progress has been made in recent years. The alkaline anion exchange membrane based direct alcohol fuel cells, one type of alkaline anion exchange membrane fuel cells utilizing liquid alcohols as fuel that can be obtained from renewable biomass feedstocks, is another attractive point due to its ability to provide electricity with cogeneration of valuable chemicals. Significant development has been made to improve the selectivity towards high added-value chemicals and power output in the past few years. This review article provides a general description of this emerging technology, including fuel-cell setup and potential reaction routes, summarizes the products, performance, and system designs, as well as introduces the application of this concept in the removal of heavy-metal ions from the industrial wastewater. In addition, the remaining challenges and perspectives are also highlighted.

  6. Mesoporous silica as a membrane for ultra-thin implantable direct glucose fuel cells.

    Science.gov (United States)

    Sharma, Tushar; Hu, Ye; Stoller, Meryl; Feldman, Marc; Ruoff, Rodney S; Ferrari, Mauro; Zhang, Xiaojing

    2011-07-21

    The design, fabrication and characterization of an inorganic catalyst based direct glucose fuel cell using mesoporous silica coating as a functional membrane is reported. The desired use of mesoporous silica based direct glucose fuel cell is for a blood vessel implantable device. Blood vessel implantable direct glucose fuel cells have access to higher continuous glucose concentrations. However, reduction in the implant thickness is required for application in the venous system as part of a stent. We report development of an implantable device with a platinum thin-film (thickness: 25 nm) deposited on silicon substrate (500 μm) to serve as the anode, and graphene pressed on a stainless steel mesh (175 μm) to serve as the cathode. Control experiments involved the use of a surfactant-coated polypropylene membrane (50 μm) with activated carbon (198 μm) electrodes. We demonstrate that a mesoporous silica thin film (270 nm) is capable of replacing the conventional polymer based membranes with an improvement in the power generated over conventional direct glucose fuel cells.

  7. Effects of temperature and stoichiometric ratio on performance of a proton exchange membrane fuel cell (PEMFC)

    Energy Technology Data Exchange (ETDEWEB)

    Park, Y.H.; Caton, J.A. [Texas A and M Univ., College Station, TX (United States). Engines, Emissions, Energy Laboratory; Parulian, A. [Arbin Instruments, College Station, TX (United States)

    2007-07-01

    Relative to any power source using any hydrocarbon fuel, the fuel cell offers the potential to produce power with minimal or zero emissions. Depending on the electrolyte utilized in the cell, there are several types of fuel cells. The most common is the proton exchange membrane fuel cell (PEMFC) because of its simplicity, quick start-up, and diversity for any application from powering small portable device to automobile applications. However, the handling and storing of hydrogen is the biggest challenge of the PEMFC. The technology related with the PEMFC, however, enables it to be commercialized in the near future as both hydrogen generation and storage continues to evolve. This paper assessed the effects of temperature and stoichiometric flow rate for various conditions for a proton exchange membrane (PEM) fuel cell. The study investigated the performance associated with the reagent stoichiometric ratio and the desired current starting stoichiometric flow rate, the effect of operating temperature, and the relationship between quantity of air used at the cathode and cell performance. The paper discussed membrane and electrode assembly (MEA) preparation as well as the study results. It was concluded that higher air supply leads to better performance at the constant stoichiometric ratio at the anode, but there is not have much of an increase after the stoichiometric ratio of 5. 14 refs., 4 tabs., 5 figs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  9. Anion exchange membranes for fuel cells and flow batteries : transport and stability of model systems

    OpenAIRE

    Marino, Michael G

    2015-01-01

    Polymeric anion exchange materials in membrane form can be key components in emerging energy storage and conversions systems such as the alkaline fuel cell and the RedOx flow battery. For these applications the membrane properties need to include good ionic conductivity and sufficient chemical stability, two aspects, that are not sufficiently understood in terms of materials science. Materials fulfilling both criteria are currently not available. The transport of ions and water in a model...

  10. A review of the development of high temperature proton exchange membrane fuel cells

    Institute of Scientific and Technical Information of China (English)

    Suthida Authayanun; Karittha Im-orb; Amornchai Arpornwichanop

    2015-01-01

    Due to the need for clean energy, the development of an efficient fuel cell technology for electricity generation has received considerable attention. Much of the current research efforts have investi‐gated the materials for and process development of fuel cells, including the optimization and simpli‐fication of the fuel cell components, and the modeling of the fuel cell systems to reduce their cost and improve their performance, durability and reliability to enable them to compete with the con‐ventional combustion engine. A high temperature proton exchange membrane fuel cell (HT‐PEMFC) is an interesting alternative to conventional PEMFCs as it is able to mitigate CO poisoning and water management problems. Although the HT‐PEMFC has many attractive features, it also possesses many limitations and presents several challenges to its widespread commercialization. In this re‐view, the trends of HT‐PEMFC research and development with respect to electrochemistry, mem‐brane, modeling, fuel options, and system design were presented.

  11. Estimation of Membrane Hydration Status for Standby Proton Exchange Membrane Fuel Cell Systems by Impedance Measurement: First Results on Variable Temperature Stack Characterization

    DEFF Research Database (Denmark)

    Bidoggia, Benoit; Kær, Søren Knudsen

    2013-01-01

    Fuel cells are getting growing interest in both backup systems and electric vehicles. Although these systems are characterized by periods of standby, they must be able to start at any instant in the shortest possible time. However, the membranes of which proton exchange membrane fuel cells are made...... way for estimating the hydration status and the temperature of its membrane before the system is started up. A summarizing table with the complete characterization of the fuel cell stack is included in this article....

  12. Co-assembly of a Nafion-mesoporous zirconium phosphate composite membrane for PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, A.K.; Pitchumani, S. [Central Electrochemical Research Institute, Karaikudi (India); Sridhar, P. [Central Electrochemical Research Institute, Karaikudi (India); Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore (India); Shukla, A.K.

    2009-04-15

    Synthesis of mesoporous zirconium phosphate (MZP) by co-assembly of a tri-block copolymer, namely pluronic-F127, as a structure-directing agent, and a mixture of zirconium butoxide and phosphorous trichloride as inorganic precursors is reported. MZP with a specific surface area of 84 m{sup 2} g{sup -1}, average pore diameter of about 17 nm and pore volume of 0.35 cm{sup 3} g{sup -1} has been prepared, and characterised by X-ray diffraction (XRD) and transmission electron microscopy. Nafion-MZP composite membrane is obtained by employing MZP as a surface-functionalised solid-super-acid-proton-conducting medium as well as an inorganic filler with high affinity to absorb water and fast proton-transport across the electrolyte membrane even under low relative humidity (RH) conditions. The composite membranes have been evaluated in H{sub 2}/O{sub 2} polymer electrolyte fuel cells (PEFCs) at varying RH values between 18 and 100%; a peak power density of 355 mW cm{sup -2} at a load current density of 1,100 mA cm{sup -2} is achieved with the PEFC employing Nafion-MZP composite membrane while operating at optimum temperature (70 C) under 18% RH and ambient pressure. On operating the PEFC employing Nafion-MZP membrane electrolyte with hydrogen and air feeds at ambient pressure and a RH value of 18%, a peak power density of 285 mW cm{sup -2} at the optimum temperature (60 C) is achieved. In contrast, operating under identical conditions, a peak power density of only {proportional_to}170 mW cm{sup -2} is achieved with the PEFC employing Nafion-1135 membrane electrolyte. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  13. Mechanical behaviour of membrane electrode assembly (MEA during cold start of PEM fuel cell from subzero environment temperature

    Directory of Open Access Journals (Sweden)

    Maher A.R. Sadiq Al-Baghdadi

    2015-01-01

    Full Text Available Durability is one of the most critical remaining issues impeding successful commercialization of broad PEM fuel cell transportation energy applications. Automotive fuel cells are likely to operate with neat hydrogen under load-following or load-levelled modes and be expected to withstand variations in environmental conditions, particularly in the context of temperature and atmospheric composition. In addition, they are also required to survive over the course of their expected operational lifetimes i.e., around 5,500 hrs, while undergoing as many as 30,000 startup/shutdown cycles. Cold start capability and survivability of proton exchange membrane fuel cells (PEM in a subzero environment temperature remain a challenge for automotive applications. A key component of increasing the durability of PEM fuel cells is studying the behaviour of the membrane electrode assembly (MEA at the heart of the fuel cell. The present work investigates how the mechanical behaviour of MEA are influenced during cold start of the PEM fuel cell from subzero environment temperatures. Full three-dimensional, non-isothermal computational fluid dynamics model of a PEM fuel cell has been developed to simulate the stresses inside the PEM fuel cell, which are occurring during fuel cell assembly (bolt assembling, and the stresses arise during fuel cell running due to the changes of temperature and relative humidity. The model is shown to be able to understand the many interacting, complex electrochemical, transport phenomena, and stresses distribution that have limited experimental data.

  14. Two phase flow simulation in a channel of a polymer electrolyte membrane fuel cell using the lattice Boltzmann method

    OpenAIRE

    Ben Salah, Yasser; Tabe, Yutaka; Chikahisa, Takemi

    2012-01-01

    Water management in polymer electrolyte (PEM) fuel cells is important for fuel cell performance and durability. Numerical simulations using the lattice Boltzmann method (LBM) are developed to elucidate the dynamic behavior of condensed water and gas flows in a polymer electrolyte membrane (PEM) fuel cell gas channel. A scheme for two-phase flow with large density differences was applied to establish the optimum gas channel design for different gas channel heights, droplet positions, and gas c...

  15. Degradation mechanisms of sulfonated poly-aromatic membranes in fuel cell; Mecanismes de degradation des membranes polyaromatiques sulfonees en pile a combustible

    Energy Technology Data Exchange (ETDEWEB)

    Perrot, C

    2006-11-15

    Fuel cell development requires an improvement in the electrode-membrane assembly durability which depends on both the polymer used and the fuel cell operating conditions. The origin of the degradation can be either electrochemical, chemical and/or mechanical. This study deals with the understanding of alternative membranes ageing mechanisms, i.e. non fluorinated membranes, such as sPEEK and sPI. For this kind of membranes, the first process is chemical. Understanding these mechanisms is the first essential step to develop more stable structures. An original approach is developed to overcome the analytical difficulties encountered with polymers. It consists in studying the degradation mechanism on model structures. Ageing are carried out in water, with H{sub 2}O{sub 2} in some cases (identified as a cause of membrane chemical ageing in the fuel cell system), and at different temperatures. The approach consists in separating the different products formed by chromatography. Then they are identified (NMR, IR, MS) and quantified. This method allows us to establish the ageing mechanism. We show that the ageing of a sPEEK structure mainly results from an attack by end chains which spreads to the whole. This mechanism is confirmed on ex-situ and in-situ aged membranes. These two kinds of ageing lead to an important decrease in polymerisation degree (determined by SEC). Formation of the same degradation products is observed. In fuel cells, a heterogeneous degradation is noticed. It takes place mainly on the cathode side. sPI are known for their high sensitivity to hydrolysis. Nevertheless, we highlight a limited degradation at 80 Celsius degrees due to the recombination of hydrolyzed species at this temperature. (author)

  16. 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

    2017-08-30

    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.

  17. Acid-doped Polybenzimidazole Membranes as Electrolyte for Fuel Cells Operating Above 100°C

    DEFF Research Database (Denmark)

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

    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 in the field is 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. A high temperature PEMFC system operational at up to 200°C is demonstrated with no gas...... humidification and high CO-tolerance up to 10 vol%. This high CO tolerance allows for a direct use of reformed hydrogen without further CO removal, which opens the possibility for an integrated reformer-fuel cell system. The content of this review is to a large extent based on research performed by the authors...

  18. A hybrid microbial fuel cell membrane bioreactor with a conductive ultrafiltration membrane biocathode for wastewater treatment

    KAUST Repository

    Malaeb, Lilian

    2013-10-15

    A new hybrid, air-biocathode microbial fuel cell-membrane bioreactor (MFC-MBR) system was developed to achieve simultaneous wastewater treatment and ultrafiltration to produce water for direct reclamation. The combined advantages of this system were achieved by using an electrically conductive ultrafiltration membrane as both the cathode and the membrane for wastewater filtration. The MFC-MBR used an air-biocathode, and it was shown to have good performance relative to an otherwise identical cathode containing a platinum catalyst. With 0.1 mm prefiltered domestic wastewater as the feed, the maximum power density was 0.38 W/m2 (6.8 W/m3) with the biocathode, compared to 0.82 W/m2 (14.5 W/m3) using the platinum cathode. The permeate quality from the biocathode reactor was comparable to that of a conventional MBR, with removals of 97% of the soluble chemical oxygen demand, 97% NH3-N, and 91% of total bacteria (based on flow cytometry). The permeate turbidity was <0.1 nephelometric turbidity units. These results show that a biocathode MFC-MBR system can achieve high levels of wastewater treatment with a low energy input due to the lack of a need for wastewater aeration. © 2013 American Chemical Society.

  19. Oxidative degradation of polybenzimidazole membranes as electrolytes for high temperature proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Liao, J.H. [The State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, Jilin 130022 (China); Energy and Materials Science Group, Department of Chemistry, Kemitorvet 207, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark); Li, Q.F.; Jensen, J.O.; Bjerrum, N.J. [Energy and Materials Science Group, Department of Chemistry, Kemitorvet 207, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark); Rudbeck, H.C. [Danish Power Systems ApS, Raadhusvej 59, DK 2920 Charlottenlund (Denmark); Chromik, A.; Kerres, J. [Institute for Chemical Process Engineering, University of Stuttgart, D-70199 Stuttgart (Germany); Xing, W. [The State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, Jilin 130022 (China)

    2011-12-15

    Polybenzimidazole membranes imbibed with acid are emerging as a suitable electrolyte material for high-temperature polymer electrolyte fuel cells. The oxidative stability of polybenzimidazole has been identified as an important issue for the long-term durability of such cells. In this paper the oxidative degradation of the polymer membrane was studied under the Fenton test conditions by the weight loss, intrinsic viscosity, size exclusion chromatography, scanning electron microscopy and Fourier transform infrared spectroscopy. During the Fenton test, significant weight losses depending on the initial molecular weight of the polymer were observed. At the same time, viscosity and SEC measurements revealed a steady decrease in molecular weight. The degradation of acid doped PBI membranes under Fenton test conditions is proposed to start by the attack of hydroxyl radicals at the carbon atom linking imidazole ring and benzenoid ring, which may eventually lead to the imidazole ring opening and formation of small molecules and terminal groups for further oxidation by an endpoint oxidation. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. NanoCapillary Network Proton Conducting Membranes for High Temperature Hydrogen/Air Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Pintauro, Peter [Vanderbilt Univ., Nashville, TN (United States)

    2012-07-09

    The objective of this proposal is to fabricate and characterize a new class of NanoCapillary Network (NCN) proton conducting membranes for hydrogen/air fuel cells that operate under high temperature, low humidity conditions. The membranes will be intelligently designed, where a high density interconnecting 3-D network of nm-diameter electrospun proton conducting polymer fibers is embedded in an inert (uncharged) water/gas impermeable polymer matrix. The high density of fibers in the resulting mat and the high ion-exchange capacity of the fiber polymer will ensure high proton conductivity. To further enhance water retention, molecular silica will be added to the sulfonated polymer fibers. The uncharged matrix material will control water swelling of the high ion-exchange capacity proton conducting polymer fibers and will impart toughness to the final nanocapillary composite membrane. Thus, unlike other fuel cell membranes, the role of the polymer support matrix will be decoupled from that of the proton-conducting channels. The expected final outcome of this 5-year project is the fabrication of fuel cell membranes with properties that exceed the DOE’s technical targets, in particular a proton conductivity of 0.1 S/cm at a temperature less than or equal to120°C and 25-50% relative humidity.

  1. Analysis of Heat Transport in a Proton Exchange Membrane (PEM Fuel Cell

    Directory of Open Access Journals (Sweden)

    E. Afshari

    2009-01-01

    Full Text Available In this study a two-phases, single-domain and non-isothermal model of a Proton Exchange Membrane (PEM fuel cell has been studied to investigate thermal management effects on fuel cell performance. A set of governing equations, conservation of mass, momentum, species, energy and charge for gas diffusion layers, catalyst layers and the membrane regions are considered. These equations are solved numerically in a single domain, using finite-volume-based computational fluid dynamics technique. Also the effects of four critical parameters that are thermal conductivity of gas diffusion layer, relative humidity, operating temperature and current density on the PEM fuel cell performance is investigated. In low operating temperatures the resistance within the membrane increases and this could cause rapid decrease in potential. High operating temperature would also reduce transport losses and it would lead to increase in electrochemical reaction rate. This could virtually result in decreasing the cell potential due to an increasing water vapor partial pressure and the membrane water dehydration. Another significant result is that the temperature distribution in GDL is almost linear but within membrane is highly non-linear. However at low current density the temperature across all regions of the cell dose not change significantly. The cell potential increases with relative humidity and improved hydration which reduces ohmic losses. Also the temperature within the cell is much higher with reduced GDL thermal conductivities. The numerical model which is developed is validated with published experimental data and the results are in good agreement.

  2. Effect of dynamic operation on chemical degradation of a polymer electrolyte membrane fuel cell

    Science.gov (United States)

    Jung, Minjae; Williams, Keith A.

    2011-03-01

    Dynamic operation is known as one of the factors for accelerating chemical degradation of the polymer electrolyte membrane in a polymer electrolyte membrane fuel cell (PEMFC). However, little effort has been made dealing with the quantification of the degradation process. In this investigation, cyclic current operation is carried out on a fuel cell system, and the frequency effect of cyclic operation on chemical degradation is investigated. The dynamic behavior of a fuel cell system is analyzed first with the modified Randles model, where the charge double layer is modeled by three components; a charge transfer resistance (Rct), and two RC cells for the Warburg impedance. After calculating each parameter value through exponential curve fitting, the dynamic behaviors of the three components are simulated using MATLAB Simulink®. Fluoride release as a function of the frequency of cyclic operation is evaluated by measuring the concentration of fluoride ion in effluent from a fuel cell exhaust. The frequency effect on chemical degradation is explained by comparing the simulated results and the fluoride release results. Two possible reasons for the accelerated degradation at cyclic operation are also suggested.

  3. 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.

  4. An extended stochastic reconstruction method for catalyst layers in proton exchange membrane fuel cells

    Science.gov (United States)

    Kang, Jinfen; Moriyama, Koji; Kim, Seung Hyun

    2016-09-01

    This paper presents an extended, stochastic reconstruction method for catalyst layers (CLs) of Proton Exchange Membrane Fuel Cells (PEMFCs). The focus is placed on the reconstruction of customized, low platinum (Pt) loading CLs where the microstructure of CLs can substantially influence the performance. The sphere-based simulated annealing (SSA) method is extended to generate the CL microstructures with specified and controllable structural properties for agglomerates, ionomer, and Pt catalysts. In the present method, the agglomerate structures are controlled by employing a trial two-point correlation function used in the simulated annealing process. An off-set method is proposed to generate more realistic ionomer structures. The variations of ionomer structures at different humidity conditions are considered to mimic the swelling effects. A method to control Pt loading, distribution, and utilization is presented. The extension of the method to consider heterogeneity in structural properties, which can be found in manufactured CL samples, is presented. Various reconstructed CLs are generated to demonstrate the capability of the proposed method. Proton transport properties of the reconstructed CLs are calculated and validated with experimental data.

  5. Stereochemistry-Dependent Proton Conduction in Proton Exchange Membrane Fuel Cells.

    Science.gov (United States)

    Thimmappa, Ravikumar; Devendrachari, Mruthyunjayachari Chattanahalli; Kottaichamy, Alagar Raja; Tiwari, Omshanker; Gaikwad, Pramod; Paswan, Bhuneshwar; Thotiyl, Musthafa Ottakam

    2016-01-12

    Graphene oxide (GO) is impermeable to H2 and O2 fuels while permitting H(+) shuttling, making it a potential candidate for proton exchange membrane fuel cells (PEMFC), albeit with a large anisotropy in their proton transport having a dominant in plane (σIP) contribution over the through plane (σTP). If GO-based membranes are ever to succeed in PEMFC, it inevitably should have a dominant through-plane proton shuttling capability (σTP), as it is the direction in which proton gets transported in a real fuel-cell configuration. Here we show that anisotropy in proton conduction in GO-based fuel cell membranes can be brought down by selectively tuning the geometric arrangement of functional groups around the dopant molecules. The results show that cis isomer causes a selective amplification of through-plane proton transport, σTP, pointing to a very strong geometry angle in ionic conduction. Intercalation of cis isomer causes significant expansion of GO (001) planes involved in σTP transport due to their mutual H-bonding interaction and efficient bridging of individual GO planes, bringing down the activation energy required for σTP, suggesting the dominance of a Grotthuss-type mechanism. This isomer-governed amplification of through-plane proton shuttling resulted in the overall boosting of fuel-cell performance, and it underlines that geometrical factors should be given prime consideration while selecting dopant molecules for bringing down the anisotropy in proton conduction and enhancing the fuel-cell performance in GO-based PEMFC.

  6. Design and Development of Membrane Electrode Assembly for Proton Exchange Membrane Fuel Cell

    Science.gov (United States)

    Kasat, Harshal Anil

    This work aimed to characterize and optimize the variables that influence the Gas Diffusion Layer (GDL) preparation using design of experiment (DOE) approach. In the process of GDL preparation, the quantity of carbon support and Teflon were found to have significant influence on the Proton Exchange Membrane Fuel Cell (PEMFC). Characterization methods like surface roughness, wetting characteristics, microstructure surface morphology, pore size distribution, thermal conductivity of GDLs were examined using laser interferometer, Goniometer, SEM, porosimetry and thermal conductivity analyzer respectively. The GDLs were evaluated in single cell PEMFC under various operating conditions of temperature and relative humidity (RH) using air as oxidant. Electrodes were prepared with different PUREBLACKRTM and poly-tetrafluoroethylene (PTFE) content in the diffusion layer and maintaining catalytic layer with a Pt-loading (0.4 mg cm-2). In the study, a 73.16 wt.% level of PB and 34 wt.% level of PTFE was the optimal compositions for GDL at 70°C for 70% RH under air atmosphere. For most electrochemical processes the oxygen reduction is very vita reaction. Pt loading in the electrocatalyst contributes towards the total cost of electrochemical devices. Reducing the Pt loading in electrocatalysts with high efficiency is important for the development of fuel cell technologies. To this end, this thesis work reports the approach to lower down the Pt loading in electrocatalyst based on N-doped carbon nanotubes derived from Zeolitic Imidazolate Frameworks (ZIF-67) for oxygen reduction. This electrocatalyst perform with higher electrocatalytic activity and stability for oxygen reduction in fuel cell testing. The electrochemical properties are mainly due to the synergistic effect from N-doped carbon nanotubes derived from ZIF and Pt loading. The strategy with low Pt loading forecasts in emerging highly active and less expensive electrocatalysts in electrochemical energy devices. This

  7. An integrated composite membrane electrode assembly (ICMEA) and its application in small H{sub 2}/air fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Nianfang [Institute of Nuclear and New Energy Technology (INET), Room A314, Energy Science Building, Tsinghua University, Beijing 100084 (China); Wang, Gang [Beijing Century Star Micropower System Ltd., Beijing (China)

    2006-09-22

    The commercialization of small fuel cells requires both the reduction of components cost and improvement of power density. To meet these requirements, we proposed the concept of an integrated composite membrane electrode assembly (ICMEA) which integrates the functions of conventional MEA, flow field, and current collector. Compared to conventional ones, it is advanced in simplification of fuel cell components, higher mechanical strength and dimensional stability, reduction in volume and weight, lower clamping pressure, and lower cost. A 200{mu}m thick ICMEA was successfully fabricated. A sandwiched structure was fabricated by attaching an e-PTFE substrate with two finely porous thin metal sheets on each side. After the impregnation of polymer electrolyte, the porous PTFE was filled with the polymer electrolyte and was bounded with the two metal sheets. Catalyst layer was directly coated on the surface of the composite membrane. At ambient conditions, the achieved maximum power density of ICMEA in H{sub 2}/air fuel cell was nearly 80mWcm{sup -2}. (author)

  8. 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.

  9. Enhanced stability of multilayer graphene-supported catalysts for polymer electrolyte membrane fuel cell cathodes

    Science.gov (United States)

    Marinkas, A.; Hempelmann, R.; Heinzel, A.; Peinecke, V.; Radev, I.; Natter, H.

    2015-11-01

    One of the biggest challenges in the field of polymer electrolyte membrane fuel cells (PEMFC) is to enhance the lifetime and the long-term stability of PEMFC electrodes, especially of cathodes, furthermore, to reduce their platinum loading, which could lead to a cost reduction for efficient PEMFCs. These demands could be achieved with a new catalyst support architecture consisting of a composite of carbon structures with significant different morphologies. A highly porous cathode catalyst support layer is prepared by addition of various carbon types (carbon black particles, multi-walled carbon nanotubes (MWCNT)) to multilayer graphene (MLG). The reported optimized cathodes shows extremely high durability and similar performance to commercial standard cathodes but with 89% lower Pt loading. The accelerated aging protocol (AAP) on the membrane electrode assemblies (MEA) shows that the presence of MLG increases drastically the durability and the Pt-extended electrochemical surface area (ECSA). In fact, after the AAP slightly enhanced performance can be observed for the MLG-containing cathodes instead of a performance loss, which is typical for the commercial carbon-based cathodes. Furthermore, the presence of MLG drastically decreases the ECSA loss rate. The MLG-containing cathodes show up to 6.8 times higher mass-normalized Pt-extended ECSA compared to the commercial standard systems.

  10. Proton Content and Nature in Perovskite Ceramic Membranes for Medium Temperature Fuel Cells and Electrolysers

    Directory of Open Access Journals (Sweden)

    Aneta Slodczyk

    2012-07-01

    Full Text Available Recent interest in environmentally friendly technology has promoted research on green house gas-free devices such as water steam electrolyzers, fuel cells and CO2/syngas converters. In such applications, proton conducting perovskite ceramics appear especially promising as electrolyte membranes. Prior to a successful industrial application, it is necessary to determine/understand their complex physical and chemical behavior, especially that related to proton incorporation mechanism, content and nature of bulk protonic species. Based on the results of quasi-elastic neutron scattering (QNS, thermogravimetric analysis (TGA, Raman and IR measurements we will show the complexity of the protonation process and the importance of differentiation between the protonic species adsorbed on a membrane surface and the bulk protons. The bulk proton content is very low, with a doping limit (~1–5 × 10−3 mole/mole, but sufficient to guarantee proton conduction below 600 °C. The bulk protons posses an ionic, covalent bond free nature and may occupy an interstitial site in the host perovskite structure.

  11. Proton content and nature in perovskite ceramic membranes for medium temperature fuel cells and electrolysers.

    Science.gov (United States)

    Colomban, Philippe; Zaafrani, Oumaya; Slodczyk, Aneta

    2012-07-25

    Recent interest in environmentally friendly technology has promoted research on green house gas-free devices such as water steam electrolyzers, fuel cells and CO2/syngas converters. In such applications, proton conducting perovskite ceramics appear especially promising as electrolyte membranes. Prior to a successful industrial application, it is necessary to determine/understand their complex physical and chemical behavior, especially that related to proton incorporation mechanism, content and nature of bulk protonic species. Based on the results of quasi-elastic neutron scattering (QNS), thermogravimetric analysis (TGA), Raman and IR measurements we will show the complexity of the protonation process and the importance of differentiation between the protonic species adsorbed on a membrane surface and the bulk protons. The bulk proton content is very low, with a doping limit (~1-5 × 10-3 mole/mole), but sufficient to guarantee proton conduction below 600 °C. The bulk protons posses an ionic, covalent bond free nature and may occupy an interstitial site in the host perovskite structure.

  12. Radiation-grafted membranes based on polyethylene for direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sherazi, Tauqir A. [Department of Chemistry, Government College University, Lahore 54000 (Pakistan); Institute for Chemical Process and Environmental Technology, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6 (Canada); Guiver, Michael D.; Kingston, David; Xue, Xinzhong [Institute for Chemical Process and Environmental Technology, National Research Council Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6 (Canada); Ahmad, Shujaat [PIEAS/PINSTECH, P O Nilore, Islamabad 45650 (Pakistan); Kashmiri, M. Akram [Department of Chemistry, Government College University, Lahore 54000 (Pakistan); Board of Intermediate and Secondary Education, Lahore 54000 (Pakistan)

    2010-01-01

    Styrene was grafted onto ultrahigh molecular weight polyethylene powder (UHMWPE) by gamma irradiation using a {sup 60}Co source. Compression moulded films of selected pre-irradiated styrene-grafted ultrahigh molecular weight polyethylene (UHMWPE-g-PS) were post-sulfonated to the sulfonic acid derivative (UHMWPE-g-PSSA) for use as proton exchange membranes (PEMs). The sulfonation was confirmed by X-ray photoelectron spectroscopy (XPS). The melting and flow properties of UHMWPE and UHMWPE-g-PS are conducive to forming homogeneous pore-free membranes. Both the ion conductivity and methanol permeability coefficient increased with degree of grafting, but the grafted membranes showed comparable or higher ion conductivity and lower methanol permeability than Nafion {sup registered} 117 membrane. One UHMWPE-g-PS membrane was fabricated into a membrane-electrode assembly (MEA) and tested as a single cell direct methanol fuel cell (DMFC). Low membrane cost and acceptable fuel cell performance indicate that UHMWPE-g-PSSA membranes could offer an alternative approach to perfluorosulfonic acid-type membranes for DMFC. (author)

  13. Radiation-grafted membranes based on polyethylene for direct methanol fuel cells

    Science.gov (United States)

    Sherazi, Tauqir A.; Guiver, Michael D.; Kingston, David; Ahmad, Shujaat; Kashmiri, M. Akram; Xue, Xinzhong

    Styrene was grafted onto ultrahigh molecular weight polyethylene powder (UHMWPE) by gamma irradiation using a 60Co source. Compression moulded films of selected pre-irradiated styrene-grafted ultrahigh molecular weight polyethylene (UHMWPE-g-PS) were post-sulfonated to the sulfonic acid derivative (UHMWPE-g-PSSA) for use as proton exchange membranes (PEMs). The sulfonation was confirmed by X-ray photoelectron spectroscopy (XPS). The melting and flow properties of UHMWPE and UHMWPE-g-PS are conducive to forming homogeneous pore-free membranes. Both the ion conductivity and methanol permeability coefficient increased with degree of grafting, but the grafted membranes showed comparable or higher ion conductivity and lower methanol permeability than Nafion ® 117 membrane. One UHMWPE-g-PS membrane was fabricated into a membrane-electrode assembly (MEA) and tested as a single cell direct methanol fuel cell (DMFC). Low membrane cost and acceptable fuel cell performance indicate that UHMWPE-g-PSSA membranes could offer an alternative approach to perfluorosulfonic acid-type membranes for DMFC.

  14. Development of cesium phosphotungstate salt and chitosan composite membrane for direct methanol fuel cells.

    Science.gov (United States)

    Xiao, Yanxin; Xiang, Yan; Xiu, Ruijie; Lu, Shanfu

    2013-10-15

    A novel composite membrane has been developed by doping cesium phosphotungstate salt (CsxH3-xPW12O40 (0≤x≤3), Csx-PTA) into chitosan (CTS/Csx-PTA) for application in direct methanol fuel cells (DMFCs). Uniform distribution of Csx-PTA nanoparticles has been achieved in the chitosan matrix. The proton conductivity of the composite membrane is significantly affected by the Csx-PTA content in the composite membrane as well as the Cs substitution in PTA. The highest proton conductivity for the CTS/Csx-PTA membranes was obtained with x=2 and Cs2-PTA content of 5 wt%. The value is 6×10(-3) S cm(-1) and 1.75×10(-2) S cm(-1) at 298 K and 353 K, respectively. The methanol permeability of CTS/Cs2-PTA membrane is about 5.6×10(-7), 90% lower than that of Nafion-212 membrane. The highest selectivity factor (φ) was obtained on CTS/Cs2-PTA-5 wt% composite membrane, 1.1×10(4)/Scm(-3)s. The present study indicates the promising potential of CTS/Csx-PTA composite membrane as alternative proton exchange membranes in direct methanol fuel cells.

  15. Properties and degradation of the gasket component of a proton exchange membrane fuel cell--a review.

    Science.gov (United States)

    Basuli, Utpal; Jose, Jobin; Lee, Ran Hee; Yoo, Yong Hwan; Jeong, Kwang-Un; Ahn, Jou-Hyeon; Nah, Changwoon

    2012-10-01

    Proton exchange membrane (PEM) fuel cell stack requires gaskets and seals in each cell to keep the reactant gases within their respective regions. Gasket performance is integral to the successful long-term operation of a fuel cell stack. This review focuses on properties, performance and degradation mechanisms of the different polymer gasket materials used in PEM fuel cell under normal operating conditions. The different degradation mechanisms and their corresponding representative mitigation strategies are also presented here. Summary of various properties of elastomers and their advantages and disadvantages in fuel cell'environment are presented. By considering the level of chemical degradation, mechanical properties and cost effectiveness, it can be proposed that EPDM is one of the best choices for gasket material in PEM fuel cell. Finally, the challenges that remain in using rubber component as in PEM fuel cell, as well as the prospects for exploiting them in the future are discussed.

  16. Performance comparison between high temperature and traditional proton exchange membrane fuel cell stacks using electrochemical impedance spectroscopy

    Science.gov (United States)

    Zhu, Ying; Zhu, Wenhua H.; Tatarchuk, Bruce J.

    2014-06-01

    A temperature above 100 °C is always desired for proton exchange membrane (PEM) fuel cell operation. It not only improves kinetic and mass transport processes, but also facilitates thermal and water management in fuel cell systems. Increased carbon monoxide (CO) tolerance at higher operating temperature also simplifies the pretreatment of fuel supplement. The novel phosphoric acid (PA) doped polybenzimidazole (PBI) membranes achieve PEM fuel cell operations above 100 °C. The performance of a commercial high temperature (HT) PEM fuel cell stack module is studied by measuring its impedance under various current loads when the operating temperature is set at 160 °C. The contributions of kinetic and mass transport processes to stack impedance are analyzed qualitatively and quantitatively by equivalent circuit (EC) simulation. The performance of a traditional PEM fuel cell stack module operated is also studied by impedance measurement and EC simulation. The operating temperature is self-stabilized between 40 °C and 65 °C. An enhancement of the HT-PEM fuel cell stack in polarization impedance is evaluated by comparing to the traditional PEM fuel cell stack. The impedance study on two commercial fuel cell stacks reveals the real situation of current fuel cell development.

  17. Perovskite solid electrolytes: Structure, transport properties and fuel cell applications

    DEFF Research Database (Denmark)

    Bonanos, N.; Knight, K.S.; Ellis, B.

    1995-01-01

    Doped barium cerate perovskites, first investigated by Iwahara and co-workers, have ionic conductivities of the order of 20 mS/cm at 800 degrees C making them attractive as fuel cell electrolytes for this temperature region. They have been used to construct laboratory scale fuel cells, which...

  18. Poly(cyclohexadiene)-Based Polymer Electrolyte Membranes for Fuel Cell Applications

    Energy Technology Data Exchange (ETDEWEB)

    Mays, Jimmy W.

    2011-03-07

    The goal of this research project was to create and develop fuel cell membranes having high proton conductivity at high temperatures and high chemical and mechanical durability. Poly(1,3-cyclohexadiene) (PCHD) is of interest as an alternative polymer electrolyte membrane (PEM) material due to its ring-like structure which is expected to impart superior mechanical and thermal properties, and due to the fact that PCHD can readily be incorporated into a range of homopolymer and copolymer structures. PCHD can be aromatized, sulfonated, or fluorinated, allowing for tuning of key performance structure and properties. These factors include good proton transport, hydrophilicity, permeability (including fuel gas impermeability), good mechanical properties, morphology, thermal stability, crystallinity, and cost. The basic building block, 1,3-cyclohexadiene, is a hydrocarbon monomer that could be inexpensively produced on a commercial scale (pricing typical of other hydrocarbon monomers). Optimal material properties will result in novel low cost PEM membranes engineered for high conductivity at elevated temperatures and low relative humidities, as well as good performance and durability. The primary objectives of this project were: (1) To design, synthesize and characterize new non-Nafion PEM materials that conduct protons at low (25-50%) RH and at temperatures ranging from room temperature to 120 C; and (2) To achieve these objectives, a range of homopolymer and copolymer materials incorporating poly(cyclohexadiene) (PCHD) will be synthesized, derivatized, and characterized. These two objectives have been achieved. Sulfonated and crosslinked PCHD homopolymer membranes exhibit proton conductivities similar to Nafion in the mid-RH range, are superior to Nafion at higher RH, but are poorer than Nafion at RH < 50%. Thus to further improve proton conductivity, particularly at low RH, poly(ethylene glycol) (PEG) was incorporated into the membrane by blending and by

  19. 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.

  20. 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.

  1. PREPARATION AND PROPERTIES OF SPAES-TiO_2 HYBRID MEMBRANES FOR DIRECT METHANOL FUEL CELL

    Institute of Scientific and Technical Information of China (English)

    刘惠玲

    2009-01-01

    Sulfonated poly(arylene ether sulfone)(SPAES) copolymer with degree of sulfonation of 1.0 was synthesized and characterized.A series of SPAES-TiO_2 hybrid membranes with various contents of nano-sized TiO_2 particles were prepared and characterized through sol-gel reactions.Scanning electron microscopy(SEM) images indicated the TiO_2 particles were well dispersed within polymer matrix.These composite membranes were evaluated for proton exchange membranes(PEMs) in direct methanol fuel cell(DMFC).These mem...

  2. Preparation of Stable Pt-Clay Nanocatalysts for Self-humidifying Proton Exchange Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Zhang, Wenjing

    ultrasonication and a rigorous mechanical agitation of Ptclay in the Nafion solution during the membrane casting process. Planar and hygroscopic clay reduced fuel crossover and balanced the water content. In situ water production for humidification of the dry membranes without any external humidification......One of the critical challenges in making proton exchange membrane (PEM) fuel cells commercially viable is the inability of Nafion (the most used PEM) to conduct protons at low water content level. Both external humidifier and physical seal of the fixture in commercial products increase the cost...

  3. Membrane fuel cell cathode catalysts based on titanium oxide supported platinum nanoparticles.

    Science.gov (United States)

    Gebauer, Christian; Jusys, Zenonas; Wassner, Maximilian; Hüsing, Nicola; Behm, R Jürgen

    2014-07-21

    The potential of platinum catalysts supported on pure, nitrogen-, or carbon-doped titania for application in the oxygen reduction reaction (ORR), as a cathode catalyst in polymer electrolyte membrane fuel cells, is investigated. The oxide supports are synthesized by using a sol-gel route. Modification with nitrogen and carbon doping is achieved by thermal decomposition of urea and the structure-directing agent P123. Platinum nanoparticles are prepared by reduction of a Pt(IV) salt in ethylene glycol and subsequently immobilized on different support materials. Structural and electronic properties of the support materials and the resulting catalysts are characterized by various methods, including X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. These results and electrochemical characterization of the support materials and platinum nanoparticle catalysts indicate distinct support effects in the catalysts. The electrocatalytic performance of these catalysts in the ORR, as determined in rotating ring disc electrode measurements, is promising. Also here, distinct support effects can be identified. Correlations with the structural/electronic and the electrochemical properties are discussed, as well as the role of metal-support interactions.

  4. Fuel cell membrane preparation: effects of base polymer

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-06-01

    Radiation grafted films and membranes prepared from the partially fluorinated base copolymer poly(ethylene-alt-tetrafluoroethylene) or ETFE have better mechanical properties than those prepared from poly(tetrafluoroethylene-co-hexafluoropropylene) or FEP. The influence of the base copolymer film type on the grafting rate and yields is reported in the present investigation. An understanding of the effects of these parameters is important so that the grafting process can be carried out reproducibly in as short a time as possible. The grafting rate and yield as a function of the irradiation dose has been found to be much higher for the partially fluorinated base copolymer ETFE. (author) 2 figs., 1 tab., 5 refs.

  5. Nanostructure-based proton exchange membrane for fuel cell applications at high temperature.

    Science.gov (United States)

    Li, Junsheng; Wang, Zhengbang; Li, Junrui; Pan, Mu; Tang, Haolin

    2014-02-01

    As a clean and highly efficient energy source, the proton exchange membrane fuel cell (PEMFC) has been considered an ideal alternative to traditional fossil energy sources. Great efforts have been devoted to realizing the commercialization of the PEMFC in the past decade. To eliminate some technical problems that are associated with the low-temperature operation (such as catalyst poisoning and poor water management), PEMFCs are usually operated at elevated temperatures (e.g., > 100 degrees C). However, traditional proton exchange membrane (PEM) shows poor performance at elevated temperature. To achieve a high-performance PEM for high temperature fuel cell applications, novel PEMs, which are based on nanostructures, have been developed recently. In this review, we discuss and summarize the methods for fabricating the nanostructure-based PEMs for PEMFC operated at elevated temperatures and the high temperature performance of these PEMs. We also give an outlook on the rational design and development of the nanostructure-based PEMs.

  6. Durability of Membrane Electrode Assemblies (MEAs) in PEM Fuel Cells Operated on Pure Hydrogen and Oxygen

    Science.gov (United States)

    Stanic, Vesna; Braun, James; Hoberecht, Mark

    2003-01-01

    Proton exchange membrane (PEM) fuel cells are energy sources that have the potential to replace alkaline fuel cells for space programs. Broad power ranges, high peak-to-nominal power capabilities, low maintenance costs, and the promise of increased life are the major advantages of PEM technology in comparison to alkaline technology. The probability of PEM fuel cells replacing alkaline fuel cells for space applications will increase if the promise of increased life is verified by achieving a minimum of 10,000 hours of operating life. Durability plays an important role in the process of evaluation and selection of MEAs for Teledyne s Phase I contract with the NASA Glenn Research Center entitled Proton Exchange Membrane Fuel cell (PEMFC) Power Plant Technology Development for 2nd Generation Reusable Launch Vehicles (RLVs). For this contract, MEAs that are typically used for H2/air operation were selected as potential candidates for H2/O2 PEM fuel cells because their catalysts have properties suitable for O2 operation. They were purchased from several well-established MEA manufacturers who are world leaders in the manufacturing of diverse products and have committed extensive resources in an attempt to develop and fully commercialize MEA technology. A total of twelve MEAs used in H2/air operation were initially identified from these manufacturers. Based on the manufacturers specifications, nine of these were selected for evaluation. Since 10,000 hours is almost equivalent to 14 months, it was not possible to perform continuous testing with each MEA selected during Phase I of the contract. Because of the lack of time, a screening test on each MEA was performed for 400 hours under accelerated test conditions. The major criterion for an MEA pass or fail of the screening test was the gas crossover rate. If the gas crossover rate was higher than the membrane intrinsic permeability after 400 hours of testing, it was considered that the MEA had failed the test. Three types of

  7. Critical Filler Concentration in Sulfated Titania-Added Nafion™ Membranes for Fuel Cell Applications

    Directory of Open Access Journals (Sweden)

    Mirko Sgambetterra

    2016-04-01

    Full Text Available In this communication we present a detailed study of Nafion™ composite membranes containing different amounts of nanosized sulfated titania particles, synthesized through an optimized one-step synthesis procedure. Functional membrane properties, such as ionic exchange capacity and water uptake (WU ability will be described and discussed, together with thermal analysis, atomic force microscopy and Raman spectroscopy data. Also electrochemical properties such as proton conductivity and performances in hydrogen fuel cells will be presented. It has been demonstrated that a critical concentration of filler particles can boost the fuel cell performance at low humidification, exhibiting a significant improvement of the maximum power and current density delivered under 30% low-relative humidity (RH and 70 °C with respect to bare Nafion™-based systems.

  8. Mass and Heat Transfer in Ion-Exchange Membranes Applicable to Solid Polymer Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Otteroey, M.

    1996-04-01

    In this doctoral thesis, an improved emf method for determination of transference numbers of two counter ions in ion-exchange membranes is presented. Transference numbers were obtained as a continuous function of the composition. The method avoids problems with diffusion by using a stack of membranes. Water transference coefficients in ion-exchange membranes is discussed and reversible and irreversible water transfer is studied by emf methods. Efforts were made to get data relevant to the solid polymer fuel cell. The results support the findings of other researchers that the reversible water transfer is lower than earlier predicted. A chapter on the conductivity of ion-exchange membranes establishes a method to separate the very thin liquid layers surrounding the membranes in a stack. Using the method it was found that the conductivity is obtained with high accuracy and that the liquid layer in a membrane stack can contribute significantly to the total measured resistance. A four point impedance method was tested to measure the conductivity of membranes under fuel cell conditions. Finally, there is a discussion of reversible heat effects and heat transfer in ion-exchange membranes. 155 refs., 45 figs., 13 tabs.

  9. Understanding the Effects of Compression and Constraints on Water Uptake of Fuel-Cell Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Kusoglu, Ahmet; Kienitz, Brian L.; Weber, Adam Z.

    2011-01-01

    Accurate characterization of polymer-electrolyte fuel cells (PEFCs) requires understanding the impact of mechanical and electrochemical loads on cell components. An essential aspect of this relationship is the effect of compression on the polymer membrane?s water-uptake behavior and transport properties. However, there is limited information on the impact of physical constraints on membrane properties. In this paper, we investigate both theoretically and experimentally how the water uptake of Nafion membrane changes under external compression loads. The swelling of a compressed membrane is modeled by modifying the swelling pressure in the polymer backbone which relies on the changes in the microscopic volume of the polymer. The model successfully predicts the water content of the compressed membrane measured through in-situ swelling-compression tests and neutron imaging. The results show that external mechanical loads could reduce the water content and conductivity of the membrane, especially at lower temperatures, higher humidities, and in liquid water. The modeling framework and experimental data provide valuable insight for the swelling and conductivity of constrained and compressed membranes, which are of interest in electrochemical devices such as batteries and fuel cells.

  10. Mass and Heat Transfer in Ion-Exchange Membranes Applicable to Solid Polymer Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Otteroey, M.

    1996-04-01

    In this doctoral thesis, an improved emf method for determination of transference numbers of two counter ions in ion-exchange membranes is presented. Transference numbers were obtained as a continuous function of the composition. The method avoids problems with diffusion by using a stack of membranes. Water transference coefficients in ion-exchange membranes is discussed and reversible and irreversible water transfer is studied by emf methods. Efforts were made to get data relevant to the solid polymer fuel cell. The results support the findings of other researchers that the reversible water transfer is lower than earlier predicted. A chapter on the conductivity of ion-exchange membranes establishes a method to separate the very thin liquid layers surrounding the membranes in a stack. Using the method it was found that the conductivity is obtained with high accuracy and that the liquid layer in a membrane stack can contribute significantly to the total measured resistance. A four point impedance method was tested to measure the conductivity of membranes under fuel cell conditions. Finally, there is a discussion of reversible heat effects and heat transfer in ion-exchange membranes. 155 refs., 45 figs., 13 tabs.

  11. Proton conductive montmorillonite-Nafion composite membranes for direct ethanol fuel cells

    Science.gov (United States)

    Wu, Xiu-Wen; Wu, Nan; Shi, Chun-Qing; Zheng, Zhi-Yuan; Qi, Hong-Bin; Wang, Ya-Fang

    2016-12-01

    The preparation of Nafion membranes modified with montmorillonites is less studied, and most relative works mainly applied in direct methanol fuel cells, less in direct ethanol fuel cells. Organic/inorganic composite membranes are prepared with different montmorillonites (Ca-montmorillonite, Na-montmorillonite, K-montmorillonite, Mg-montmorillonite, and H-montmorillonite) and Nafion solution via casting method at 293 K in air, and with balance of their proton conductivity and ethanol permeability. The ethanol permeability and proton conductivity of the membranes are comparatively studied. The montmorillonites can well decrease the ethanol permeability of the membranes via inserted them in the membranes, while less decrease the proton conductivities of the membranes depending on the inserted amount and type of montmorillonites. The proton conductivities of the membranes are between 36.0 mS/cm and 38.5 mS/cm. The ethanol permeability of the membranes is between 0.69 × 10-6 cm2/s and 2.67 × 10-6 cm2/s.

  12. Modeling and simulation of the dynamic behavior of portable proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ziegler, C.

    2005-07-01

    In order to analyze the operational behavior, a mathematical model of planar self-breathing fuel cells is developed and validated in Chapter 3 of this thesis. The multicomponent transport of the species is considered as well as the couplings between the transport processes of heat, charge, and mass and the electrochemical reactions. Furthermore, to explain the oxygen mass transport limitation in the porous electrode of the cathode side an agglomerate model for the oxygen reduction reaction is developed. In Chapter 4 the important issue of liquid water generation and transport in PEMFCs is addressed. One of the major tasks when operating this type of fuel cell is avoiding the complete flooding of the PEMFC during operation. A one-dimensional and isothermal model is developed that is based on a coupled system of partial differential equations. The model contains a dynamic and two-phase description of the proton exchange membrane fuel cell. The mass transport in the gas phase and in the liquid phase is considered as well as the phase transition between liquid water and water vapor. The transport of charges and the electrochemical reactions are part of the model. Flooding effects that are caused by liquid water accumulation are described by this model. Moreover, the model contains a time-dependent description of the membrane that accounts for Schroeder's paradox. The model is applied to simulate cyclic voltammograms. Chapter 5 is focused on the dynamic investigation of PEMFC stacks. Understanding the dynamic behavior of fuel cell stacks is important for the operation and control of fuel cell stacks. Using the single cell model of Chapter 3 and the dynamic model of Chapter 4 as basis, a mathematical model of a PEMFC stack is developed. However, due to the complexity of a fuel cell stack, the spatial resolution and dynamic description of the liquid water transport are not accounted for. These restrictions allow for direct comparison between the solution variables of

  13. Gas phase recovery of hydrogen sulfide contaminated polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Kakati, Biraj Kumar; Kucernak, Anthony R. J.

    2014-04-01

    The effect of hydrogen sulfide (H2S) on the anode of a polymer electrolyte membrane fuel cell (PEMFC) and the gas phase recovery of the contaminated PEMFC using ozone (O3) were studied. Experiments were performed on fuel cell electrodes both in an aqueous electrolyte and within an operating fuel cell. The ex-situ analyses of a fresh electrode; a H2S contaminated electrode (23 μmolH2S cm-2); and the contaminated electrode cleaned with O3 shows that all sulfide can be removed within 900 s at room temperature. Online gas analysis of the recovery process confirms the recovery time required as around 720 s. Similarly, performance studies of an H2S contaminated PEMFC shows that complete rejuvenation occurs following 600-900 s O3 treatment at room temperature. The cleaning process involves both electrochemical oxidation (facilitated by the high equilibrium potential of the O3 reduction process) and direct chemical oxidation of the contaminant. The O3 cleaning process is more efficient than the external polarization of the single cell at 1.6 V. Application of O3 at room temperature limits the amount of carbon corrosion. Room temperature O3 treatment of poisoned fuel cell stacks may offer an efficient and quick remediation method to recover otherwise inoperable systems.

  14. DEVELOPMENT AND SELECTION OF IONIC LIQUID ELECTROLYTES FOR HYDROXIDE CONDUCTING POLYBENZIMIDAZOLE MEMBRANES IN ALKALINE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Fox, E.

    2012-05-01

    Alkaline fuel cell (AFC) operation is currently limited to specialty applications such as low temperatures and pure HO due to the corrosive nature of the electrolyte and formation of carbonates. AFCs are the cheapest and potentially most efficient (approaching 70%) fuel cells. The fact that non-Pt catalysts can be used, makes them an ideal low cost alternative for power production. The anode and cathode are separated by and solid electrolyte or alkaline porous media saturated with KOH. However, CO from the atmosphere or fuel feed severely poisons the electrolyte by forming insoluble carbonates. The corrosivity of KOH (electrolyte) limits operating temperatures to no more than 80°C. This chapter examines the development of ionic liquids electrolytes that are less corrosive, have higher operating temperatures, do not chemically bond to CO and enable alternative fuels. Work is detailed on the IL selection and characterization as well as casting methods within the polybenzimidazole based solid membrane. This approach is novel as it targets the root of the problem (the electrolyte) unlike other current work in alkaline fuel cells which focus on making the fuel cell components more durable.

  15. Superhydrophobic PAN nanofibers for gas diffusion layers of proton exchange membrane fuel cells

    Science.gov (United States)

    Salahuddin, Mohammad; Hwang, Gisuk; Asmatulu, Ramazan

    2016-04-01

    Proton exchange membrane (PEM) fuel cells are considered to be the promising alternatives of natural resources for generating electricity and power. An optimal water management in the gas diffusion layers (GDL) is critical to high fuel cell performance. Its basic functions include transportation of the reactant gas from flow channels to catalyst effectively, draining out the liquid water from catalyst layer to flow channels, and conducting electrons with low humidity. In this study, polyacrylonitrile (PAN) was dissolved in a solvent and electrospun at various conditions to produce PAN nanofibers prior to the stabilization at 280 °C for 1 hour in the atmospheric pressure and carbonization at 850 °C for 1 hour. The surface hydrophobicity values of the carbonized PAN nanofibers were adjusted using superhydrophobic and hydrophilic agents. The thermal, mechanical, and electrical properties of the new GDLs depicted much better results compared to the conventionally used ones. The water condensation tests on the surfaces (superhydrophobic and hydrophilic) of the GDL showed a crucial step towards improved water managements in the fuel cell. This study may open up new possibilities for developing high- performing GDL materials for future PEM fuel cell applications.

  16. Contact behavior modelling and its size effect on proton exchange membrane fuel cell

    Science.gov (United States)

    Qiu, Diankai; Peng, Linfa; Yi, Peiyun; Lai, Xinmin; Janßen, Holger; Lehnert, Werner

    2017-10-01

    Contact behavior between the gas diffusion layer (GDL) and bipolar plate (BPP) is of significant importance for proton exchange membrane fuel cells. Most current studies on contact behavior utilize experiments and finite element modelling and focus on fuel cells with graphite BPPs, which lead to high costs and huge computational requirements. The objective of this work is to build a more effective analytical method for contact behavior in fuel cells and investigate the size effect resulting from configuration alteration of channel and rib (channel/rib). Firstly, a mathematical description of channel/rib geometry is outlined in accordance with the fabrication of metallic BPP. Based on the interface deformation characteristic and Winkler surface model, contact pressure between BPP and GDL is then calculated to predict contact resistance and GDL porosity as evaluative parameters of contact behavior. Then, experiments on BPP fabrication and contact resistance measurement are conducted to validate the model. The measured results demonstrate an obvious dependence on channel/rib size. Feasibility of the model used in graphite fuel cells is also discussed. Finally, size factor is proposed for evaluating the rule of size effect. Significant increase occurs in contact resistance and porosity for higher size factor, in which channel/rib width decrease.

  17. Prognostics of Proton Exchange Membrane Fuel Cells stack using an ensemble of constraints based connectionist networks

    Science.gov (United States)

    Javed, Kamran; Gouriveau, Rafael; Zerhouni, Noureddine; Hissel, Daniel

    2016-08-01

    Proton Exchange Membrane Fuel Cell (PEMFC) is considered the most versatile among available fuel cell technologies, which qualify for diverse applications. However, the large-scale industrial deployment of PEMFCs is limited due to their short life span and high exploitation costs. Therefore, ensuring fuel cell service for a long duration is of vital importance, which has led to Prognostics and Health Management of fuel cells. More precisely, prognostics of PEMFC is major area of focus nowadays, which aims at identifying degradation of PEMFC stack at early stages and estimating its Remaining Useful Life (RUL) for life cycle management. This paper presents a data-driven approach for prognostics of PEMFC stack using an ensemble of constraint based Summation Wavelet- Extreme Learning Machine (SW-ELM) models. This development aim at improving the robustness and applicability of prognostics of PEMFC for an online application, with limited learning data. The proposed approach is applied to real data from two different PEMFC stacks and compared with ensembles of well known connectionist algorithms. The results comparison on long-term prognostics of both PEMFC stacks validates our proposition.

  18. Proton Exchange Membrane Fuel Cell Modeling Based on Seeker Optimization Algorithm

    Institute of Scientific and Technical Information of China (English)

    LI Qi; DAI Chao-hua; Chen Wei-rong; JIA Jun-bo; HAN Ming

    2008-01-01

    Seeker optimization algorithm (SOA) has applications in continuous space of swarm intelligence. In the fields of proton ex-change membrane fuel cell (PEMFC) modeling, SOA was proposed to research a set of optimized parameters in PEMFC polariza-tion curve model. Experimental result showed that the mean square error of the optimization modeling strategy was only 6.9 × 10-23. Hence, the optimization model could fit the experiment data with high precision.

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

    OpenAIRE

    2009-01-01

    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 ...

  20. 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 ran...

  1. Effects of Straight and Serpentine Flow Field Designs on Temperature Distribution in Proton Exchange Membrane (PEM Fuel Cell

    Directory of Open Access Journals (Sweden)

    Zaman Izzuddin

    2016-01-01

    Full Text Available Proton exchange membrane fuel cells or sometimes called as polymer electrolyte membrane (PEM fuel cells is a device for energy transformation in a changing process from one form of energy to another form of energy. It became as an alternative especially for future use in stationary and vehicular applications. PEM fuel cells provide high efficiency and power density with null emission, low operating temperature, quickly start and long life. One of the aspects that are crucial in optimizing the PEM fuel cells performance is a flow field geometry. In this paper, a simulation case of PEM fuel cells was simulated to determine effects of a straight and serpentine flow field on temperature distribution in PEM fuel cells. ANSYS Fluent software was used to simulate 3-dimensional models of single PEM fuel cells in order to determine the effects of changes in the geometry flow field on temperature distributions. Results showed that the serpentine flow field design produces a better temperature distribution along the membrane. The simulation result shows a good agreement with the experiment, thus boost a higher confidence in the results to determine the effectiveness of the flow field design in PEM fuel cells.

  2. Estimation of Membrane Hydration Status for Standby Proton Exchange Membrane Fuel Cell Systems by Impedance Measurement: First Results on Stack Characterization

    DEFF Research Database (Denmark)

    Bidoggia, Benoit; Kær, Søren Knudsen

    Fuel cells have started replacing traditional lead-acid battery banks in backup systems. Although these systems are characterized by long periods of standby, they must be able to start at any instant in the shortest time. In the case of low temperature proton exchange membrane fuel cell systems......, a precise estimation of hydration status of the fuel cell during standby is important for a fast and safe startup. In this article, the measurement of the complex impedance of the fuel cell is suggested as a method to estimate the membrane hydration status. A 56-cell fuel cell stack has been symmetrically...... was applied, and the relationship between module of impedance and relative humidity was found. The results showed that measuring the impedance of a fuel cell during standby can be a viable way for estimating the hydration status of its membrane....

  3. Iron-based cathode catalyst with enhanced power density in polymer electrolyte membrane fuel cells.

    Science.gov (United States)

    Proietti, Eric; Jaouen, Frédéric; Lefèvre, Michel; Larouche, Nicholas; Tian, Juan; Herranz, Juan; Dodelet, Jean-Pol

    2011-08-02

    H(2)-air polymer-electrolyte-membrane fuel cells are electrochemical power generators with potential vehicle propulsion applications. To help reduce their cost and encourage widespread use, research has focused on replacing the expensive Pt-based electrocatalysts in polymer-electrolyte-membrane fuel cells with a lower-cost alternative. Fe-based cathode catalysts are promising contenders, but their power density has been low compared with Pt-based cathodes, largely due to poor mass-transport properties. Here we report an iron-acetate/phenanthroline/zeolitic-imidazolate-framework-derived electrocatalyst with increased volumetric activity and enhanced mass-transport properties. The zeolitic-imidazolate-framework serves as a microporous host for phenanthroline and ferrous acetate to form a catalyst precursor that is subsequently heat treated. A cathode made with the best electrocatalyst from this work, tested in H(2)-O(2,) has a power density of 0.75 W cm(-2) at 0.6 V, a meaningful voltage for polymer-electrolyte-membrane fuel cells operation, comparable with that of a commercial Pt-based cathode tested under identical conditions.

  4. Two-dimensional, isothermal, multi-component model for a polymer electrolyte membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Mahinpey, N.; Jagannathan, A.; Idem, R. [Regina Univ., SK (Canada). Faculty of Engineering

    2007-07-01

    A fuel cell is an electrochemical energy conversion device which is more efficient than an internal combustion engine in converting fuel to power. Numerous fuel cell models have been developed by a number of authors accounting for the various physical processes. Earlier models were restricted to being one dimensional, steady-state, and isothermal while more recent two-dimensional models had several limitations. This paper presented the results of a study that developed a two-dimensional computational fluid dynamics model of a polymer electrolyte membrane fuel cell using a finite element method to solve a multi-component transport model coupled with flow in porous media, charge balance, electrochemical kinetics, and rigorous water balance in the membrane. The mass transport, momentum transport, and electrochemical processes occurring in the membrane electrolyte and catalyst layers were modeled. The local equilibrium was assumed at the interfaces and the model was combined with the kinetics and was analytically solved for the anodic and cathodic current using an agglomerate spherical catalyst pellet. The paper compared the modeling results with previously published experimental data. The study investigated the effects of channel and bipolar plate shoulder size, porosity of the electrodes, temperature, relative humidity and current densities on the cell performance. It was concluded that smaller sized channels and bipolar plate shoulders were required to obtain higher current densities, although larger channels were satisfactory at moderate current densities. 13 refs., 5 figs.

  5. Alkaline membrane fuel cells with in-situ cross-linked ionomers

    Energy Technology Data Exchange (ETDEWEB)

    Leng, YJ; Wang, LZ; Hickner, MA; Wang, CY

    2015-01-10

    Improving cell performance and durability through both new materials and membrane electrode processing optimization is needed for the commercialization of alkaline membrane fuel cell (AMFC) technologies. In this work, we adopted an in-situ cross-linking strategy of an anion-conducting block copolymer to prepare durable ionomers for use in alkaline membrane fuel cells (AMFCs). Our goal was to use new ionomers and binders with an aim at improving long-term stability of AMFCs, especially at high operation temperatures. At 80 degrees C, AMFCs with in-situ cross-linked ionomers showed promising stability with an operating life time of more than 350 hours at 100 mA/cm(2). We found that the optimized electrode fabrication process and operating conditions can significantly improve the durability performance of AMFCs. For example, a suitable electrode binder in addition to the ion-conducting ionomer can greatly enhance the durability performance of AMFCs. Operating fuel cells under a cathode over-humification condition can also enhance the long-term stability of AMFCs. (C) 2014 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    The electrolyte of choice for low temperature polymer electrolyte fuel cells (PEFCs) has tra­di­ti­o­nal­ly been DuPontTM Nafion® membranes or similar poly(perfluorosulfonic acid)s. The chemical struc­ture and morphology in the hydrated state of Nafion® is shown in figure 1 from which it is seen...... found that crosslinking by divinylbenzene clear­ly improves the chemical stability of both sulfonated styrene- and methylstyrene/t-butylstyrene-grafted ETFE membranes. How­ever, the crosslinking reduces the proton conductivity due to decreased water uptake, thus downgrading the membranes' elec­tro­ly­tic.......; 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...

  7. 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 methanol containing H2 which was composed of H2, steam and methanol as the fuel were performed on both single cells. After the continuous tests, 12-h-startup/12-h-shutdown dynamic tests were performed on the first single cell with H2 as the fuel and on the second single cell with methanol containing H2...... as the fuel. Along with the degradation tests, electrochemical techniques such as polarization curves and electrochemical impedance spectroscopy (EIS) were employed to study the degradation mechanisms of the fuel cells. The results of the tests showed that both single cells experienced an increase...

  8. Study of basic biopolymer as proton membrane for fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Salgado, Joel [Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Lazaro Cardenas No. 152, CP 07730, Mexico D.F. (Mexico)

    2007-03-01

    Up to now, many research groups work to improve the electrical and mechanical properties of membranes with a low cost of production. The biopolymers could be an answer to produce proton membranes at low cost. This work demonstrates that the intrinsic membrane polymer and clays properties can help to develop a novel proton exchange membranes. Biopolymer composites (chitosan-oxide compounds) present conductivity between 10{sup -3} and 10{sup -2} S cm{sup -1}. The measurements were calculated by EIS (1 MHz-0.05 Hz) using the two-electrode configuration. Different oxides were used: MgO, CaO, SiO{sub 2}, Al{sub 2}O{sub 3}. The ionic conductivities were compared with Nafion {sup registered} 's in the same conditions of P and T. The catalyst layer/membrane ensemble was made during the design with the subsequent demonstration as membrane electrode assemblies and finally the fuel cell was built. Our focus was to increase the compatibility between the proton basic polymer exchange membrane and basic clays as CaO and test a new kind of fuel cell. (author)

  9. Long-term testing of a high-temperature proton exchange membrane fuel cell short stack operated with improved polybenzimidazole-based composite membranes

    Science.gov (United States)

    Pinar, F. Javier; Cañizares, Pablo; Rodrigo, Manuel A.; Úbeda, Diego; Lobato, Justo

    2015-01-01

    In this work, the feasibility of a 150 cm2 high-temperature proton exchange membrane fuel cell (HT-PEMFC) stack operated with modified proton exchange membranes is demonstrated. The short fuel cell stack was manufactured using a total of three 50 cm2 membrane electrode assemblies (MEAs). The PEM technology is based on a polybenzimidazole (PBI) membrane. The obtained results were compared with those obtained using a HT-PEMFC stack with unmodified membranes. The membranes were cast from a PBI polymer synthesized in the laboratory, and the modified membranes contained 2 wt.% micro-sized TiO2 as a filler. Long-term tests were performed in both constant and dynamic loading modes. The fuel cell stack with 2 wt.% TiO2 composite PBI membranes exhibited an irreversible voltage loss of less than 2% after 1100 h of operation. In addition, the acid loss was reduced from 2% for the fuel cell stack with unmodified membranes to 0.6% for the fuel cell stack with modified membranes. The results demonstrate that introducing filler into the membranes enhances the durability and stability of this type of fuel cell technology. Moreover, the fuel cell stack system also exhibits very rapid and stable power and voltage output responses under dynamic load regimes.

  10. Proton Exchange Membrane (PEM) Material Synthetic Design for Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    Michael; D.Guiver; Dae-Sik; Kim; Gilles; P.Robertson; Yu; Seung; Kim; Bryan; S.Pivovar

    2007-01-01

    1 Results Hydrocarbon PEM materials are being widely studied as replacements for Nafion-type perfluorinated polymeric materials to reduce cost and improve performance such as operating temperature and methanol crossover in the DMFC application. Among some of the important property considerations required are thermal and chemical stability, low dimensional swelling, low methanol permeability in the case of DMFC and high proton conductivity. Careful structural design can reduce the effect of swelling as...

  11. Development of a method to estimate the lifespan of proton exchange membrane fuel cell using electrochemical impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju-hyung; Lee, Jong-Hak; Choi, Woojin [Department of Electrical Engineering, Soongsil University, 1-1 Sangdo-dong, Dongjak-gu, Seoul 156-743 (Korea); Park, Kyung-Won [Department of Chemical/Environmental Engineering, Soongsil University, 1-1 Sangdo-dong, Dongjak-gu, Seoul 156-743 (Korea); Sun, Hee-Young [Samsung Advanced Institute of Technology, Mt. 14-1, Nongseo-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-712 (Korea); Oh, Jae-Hyuk [Samsung Electronics, 416 Maetan-dong, Youngtong-gu, Suwon-si, Gyeonggi-do 443-370 (Korea)

    2010-09-15

    This paper proposes a new method for estimating the state and lifespan of fuel cells in operation by fuel cell equivalent impedance modeling by electrochemical impedance spectroscopy (EIS) and observing degradation. The performance change of fuel cells takes place in the form of changes in each parameter value comprising an equivalent AC impedance circuit; monitoring such changes allows for the prediction of the state and lifespan of a fuel cell. In the experiments, the AC impedance of high-temperature proton exchange membrane (PEM) fuel cells was measured at constant time intervals during their continuous operation for over 2200 h. The expression for the lifespan of a fuel cell was deduced by curve fitting the changes in each parameter to a polynomial. Electric double layer capacitance and charge transfer resistance, which show the reduction reaction of the cathode, were used as major parameters for judging the degradation; a method of using time constants is proposed to more accurately estimate the degree of degradation. In addition, an algorithm that can evaluate the soundness and lifespan of a fuel cell is proposed; it compares the measured time constant of the fuel cell being tested with that of average lifespan fuel cell. (author)

  12. Advanced manufacturing of intermediate temperature, direct methane oxidation membrane electrode assemblies for durable solid oxide fuel cell Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ITN proposes to create an innovative anode supported membrane electrode assembly (MEA) for solid oxide fuel cells (SOFCs) that is capable of long-term operation at...

  13. Oxidative degradation of acid doped polybenzimidazole membranes and fuel cell durability in the presence of ferrous ions

    DEFF Research Database (Denmark)

    Liao, Jianhui; Yang, Jingshuai; Li, Qingfeng

    2013-01-01

    Phosphoric acid doped polybenzimidazole membranes have been explored as proton exchange membranes for high temperature polymer electrolyte membrane fuel cells. Long-term durability of the membrane is of critical concern and has been evaluated by accelerated degradation tests under Fenton conditio...

  14. Highly charged proton-exchange membrane. Sulfonated poly(ether sulfone)-silica polyelectrolyte composite membranes for fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Shahi, Vinod K. [Electro-Membrane Processes Division, Central Salt and Marine Chemicals Research Institute, Bhavnagar-364002, Gujarat (India)

    2007-01-15

    Sulfonation of poly(ether sulfone) was carried out with chlorosulphonic acid in chloroform and its composite proton-exchange membrane was prepared using aminopropyltriethoxysilane as inorganic precursor by sol-gel in acidic medium. These membranes were further subjected to phosphorylation with phosphorous acid for introducing phosphonic acid functionality at inorganic segment. Extent of sulphonation was estimated by {sup 1}H-NMR spectroscopy while introduction of phosphonic acid groups was confirmed by FTIR spectroscopy and ion-exchange capacity studies. Different membranes, with varied silica content without and with phosphorylation, were characterized for their thermal and mechanical stabilities, physicochemical and electrochemical properties using thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), aq. methanol uptake studies, proton conductivity and methanol permeability measurements. The silica content in the membrane matrix and effect of phosphorylation was optimized as a function of membrane properties. Activation energy required for the proton transport across the membrane was also estimated and found to be comparable with Nafion 117 membrane. From the frictional interpretation and estimation of selectivity parameter it was observed that SPS-Si composite phosphorylated membrane with 20% silica content (SPS-Si(P)/20) resulted in the best proton-exchange membrane, which exhibited quite higher selectivity parameter in comparison to Nafion 117 for direct methanol fuel cell applications. Also, current-voltage polarization characteristics of SPS-Si(P)/20 membrane measured in direct methanol fuel cell, were found to be comparable to the Nafion 117 membrane. (author)

  15. Employing Hot Wire Anemometry to Directly Measure the Water Balance of a Proton Exchange Membrane Fuel Cell

    DEFF Research Database (Denmark)

    Shakhshir, Saher Al; Berning, Torsten

    Proton exchange membrane fuel cells (PEMFC’s) are currently being commercialized for various applications ranging from automotive to stationary such as powering telecom back-up units. In PEMFC’s, oxygen from air is internally combined with hydrogen to form water and produce electricity and waste...... heat. One critical technical problem of these fuel cells is still the water management: the proton exchange membrane in the center of these fuel cells has to be hydrated in order to stay proton-conductive while excessive liquid water can lead to cell flooding and increased degradation rates. Clearly...

  16. Pre-oxidized and nitrided stainless steel alloy foil for proton exchange membrane fuel cell bipolar plates. Part 2: Single-cell fuel cell evaluation of stamped plates

    Science.gov (United States)

    Toops, Todd J.; Brady, Michael P.; Tortorelli, Peter F.; Pihl, Josh A.; Estevez, Francisco; Connors, Daniel; Garzon, Fernando; Rockward, Tommy; Gervasio, Don; Mylan, William; Kosaraju, Sree Harsha

    Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr 2N, CrN, TiN, V 2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of proton exchange membrane (PEM) single-cell fuel cell studies of stamped and pre-oxidized/nitrided developmental Fe-20Cr-4V weight percent (wt.%) and commercial type 2205 stainless steel alloy foils. The single-cell fuel cell behavior of the stamped and pre-oxidized/nitrided material was compared to as-stamped (no surface treatment) 904L, 2205, and Fe-20Cr-4V stainless steel alloy foils and machined graphite of similar flow field design. The best fuel cell behavior among the alloys was exhibited by the pre-oxidized/nitrided Fe-20Cr-4V, which exhibited ∼5-20% better peak power output than untreated Fe-20Cr-4V, 2205, and 904L metal stampings. Durability was assessed for pre-oxidized/nitrided Fe-20Cr-4V, 904L metal, and graphite plates by 1000+ h of cyclic single-cell fuel cell testing. All three materials showed good durability with no significant degradation in cell power output. Post-test analysis indicated no metal ion contamination of the membrane electrode assemblies (MEAs) occurred with the pre-oxidized and nitrided Fe-20Cr-4V or graphite plates, and only a minor amount of contamination with the 904L plates.

  17. Erythrocyte-like hollow carbon capsules and their application in proton exchange membrane fuel cells.

    Science.gov (United States)

    Kim, Jung Ho; Yu, Jong-Sung

    2010-12-14

    Hierarchical nanostructured erythrocyte-like hollow carbon (EHC) with a hollow hemispherical macroporous core of ca. 230 nm in diameter and 30-40 nm thick mesoporous shell was synthesized and explored as a cathode catalyst support in a proton exchange membrane fuel cell (PEMFC). The morphology control of EHC was successfully achieved using solid core/mesoporous shell (SCMS) silica template and different styrene/furfuryl alcohol mixture compositions by a nanocasting method. The EHC-supported Pt (20 wt%) cathodes prepared have demonstrated markedly enhanced catalytic activity towards oxygen reduction reactions (ORRs) and greatly improved PEMFC polarization performance compared to carbon black Vulcan XC-72 (VC)-supported ones, probably due to the superb structural characteristics of the EHC such as uniform size, well-developed porosity, large specific surface area and pore volume. In particular, Pt/EHC cathodes exhibited ca. 30-60% higher ORR activity than a commercial Johnson Matthey Pt catalyst at a low catalyst loading of 0.2 mg Pt cm(-2).

  18. Highly efficient single-layer gas diffusion layers for the proton exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Hung, T.F.; Bai, S.H.; Lai, Y.J.; Chen-Yang, Y.W. [Department of Chemistry and Center for Nanotechnology, Chung Yuan Christian University, Chung-Li 32023 (China); Huang, J. [Yeu Ming Tai Chemical Industrial Co., Ltd., Taichung 40768 (China); Chuang, H.J. [Materials and Electro-Optics Research Division, Electric Energy Section, Chung Shan Institute of Science and Technology, Lung-Tan 32544 (China)

    2008-09-15

    In the present study, a series of highly efficient single-layer gas diffusion layers (SL-GDLs) was successfully prepared by the addition of a vapor grown carbon nanofiber (VGCF) in the carbon black/poly(tetrafluoroethylene) composite-based SL-GDL through a simple and inexpensive process. The scanning electron micrographs of the as-prepared VGCF-containing SL-GDLs (SL-GDL-CFs) showed that the GDLs had a microporous layer (MPL)-like structure, while the wire-like VGCFs were well dispersed and crossed among the carbon black particles in the SL-GDL matrix. Utilization of the SL-GDL-CFs for MEA fabrication was also done by direct coating with the catalyst layer. Due to the presence of VGCFs, the properties of the SL-GDL-CFs, including electronic resistivity, mechanical characteristic, gas permeability, and water repellency, varied with the VGCF content, with the overall effect beneficial to the performance of the proton exchange membrane fuel cell (PEMFC). The best performances obtained from the PEMFC with VGCFs at 15 wt.% was approximately 63% higher than those without VGCFs, and about 85% as efficient as ELAT GDL, a commercial dual-layer GDL, for both the H{sub 2}/O{sub 2} and H{sub 2}/air systems. (author)

  19. Oxygen reduction electrocatalysts in solid polymer fuel cell membrane electrode assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Ralph, T.R.; Keating, J.E.; Collis, N.J.; Hyde, T.I.

    1997-07-01

    The feasibility of using platinum/base metal alloy electrodes in the cathode to improve the performance of a 50 mV solid polymer fuel cell (SPFC) under typical operating conditions was investigated. A range of alloys of platinum with iron, manganese, titanium, chromium, copper and nickel were prepared at a nominal 50:50 platinum to base metal ratio and supported on Vulcan Xc72R carbon black. The catalysts were fired in an inert atmosphere at temperatures between 650{sup o}C and 930{sup o}C to create the alloy catalysts, which were then incorporated into Nafion coated cathodes. Cell performance was assessed using a standard anode structure in membrane-based electrode assembles (MEAs). A clear electrokinetic benefit for some alloys (eg Pt/Fe, Pt/Mn and Pt/Cr over the range of alloying temperatures and Pt/Ti at 930{sup o}C) was found. This benefit was found to be due to improved rates of oxygen reduction with the alloys.

  20. 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...... stoichiometry may even be as low as 1.05. The effect of operation pressure and temperature on the membrane water content is studied. Finally, experiments are suggested to determine the kinetic absorption coefficient and the specific surface area of the electrolyte inside the catalyst layers....

  1. Method for recovering catalytic elements from fuel cell membrane electrode assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Shore, Lawrence [Edison, NJ; Matlin, Ramail [Berkeley Heights, NJ; Heinz, Robert [Ludwigshafen, DE

    2012-06-26

    A method for recovering catalytic elements from a fuel cell membrane electrode assembly is provided. The method includes converting the membrane electrode assembly into a particulate material, wetting the particulate material, forming a slurry comprising the wetted particulate material and an acid leachate adapted to dissolve at least one of the catalytic elements into a soluble catalytic element salt, separating the slurry into a depleted particulate material and a supernatant containing the catalytic element salt, and washing the depleted particulate material to remove any catalytic element salt retained within pores in the depleted particulate material.

  2. Chitosan-phosphotungstic acid complex as membranes for low temperature H2-O2 fuel cell

    Science.gov (United States)

    Santamaria, M.; Pecoraro, C. M.; Di Quarto, F.; Bocchetta, P.

    2015-02-01

    Free-standing Chitosan/phosphotungstic acid polyelectrolyte membranes were prepared by an easy and fast in-situ ionotropic gelation process performed at room temperature. Scanning electron microscopy was employed to study their morphological features and their thickness as a function of the chitosan concentration. The membrane was tested as proton conductor in low temperature H2-O2 fuel cell allowing to get peak power densities up to 350 mW cm-2. Electrochemical impedance measurements allowed to estimate a polyelectrolyte conductivity of 18 mS cm-1.

  3. 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...

  4. 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].

  5. Performance improvement of proton exchange membrane fuel cell by using annular shaped geometry

    Science.gov (United States)

    Khazaee, I.; Ghazikhani, M.

    2011-03-01

    A complete three-dimensional and single phase CFD model for a different geometry of proton exchange membrane (PEM) fuel cell is used to investigate the effect of using different connections between bipolar plate and gas diffusion layer on the performances, current density and gas concentration. The proposed model is a full cell model, which includes all the parts of the PEM fuel cell, flow channels, gas diffusion electrodes, catalyst layers and the membrane. Coupled transport and electrochemical kinetics equations are solved in a single domain; therefore no interfacial boundary condition is required at the internal boundaries between cell components. This computational fluid dynamics code is used as the direct problem solver, which is used to simulate the three-dimensional mass, momentum and species transport phenomena as well as the electron- and proton-transfer process taking place in a PEMFC that cannot be investigated experimentally. The results show that the predicted polarization curves by using this model are in good agreement with the experimental results. Also the results show that by increasing the number of connection between GDL and bipolar plate the performance of the fuel cell enhances.

  6. Structural dynamics and activity of nanocatalysts inside fuel cells by in operando atomic pair distribution studies

    Science.gov (United States)

    Petkov, Valeri; Prasai, Binay; Shan, Shiyao; Ren, Yang; Wu, Jinfang; Cronk, Hannah; Luo, Jin; Zhong, Chuan-Jian

    2016-05-01

    Here we present the results from a study aimed at clarifying the relationship between the atomic structure and activity of nanocatalysts for chemical reactions driving fuel cells, such as the oxygen reduction reaction (ORR). In particular, using in operando high-energy X-ray diffraction (HE-XRD) we tracked the evolution of the atomic structure and activity of noble metal-transition metal (NM-TM) nanocatalysts for ORR as they function at the cathode of a fully operational proton exchange membrane fuel cell (PEMFC). Experimental HE-XRD data were analysed in terms of atomic pair distribution functions (PDFs) and compared to the current output of the PEMFC, which was also recorded during the experiments. The comparison revealed that under actual operating conditions, NM-TM nanocatalysts can undergo structural changes that differ significantly in both length-scale and dynamics and so can suffer losses in their ORR activity that differ significantly in both character and magnitude. Therefore we argue that strategies for reducing ORR activity losses should implement steps for achieving control not only over the length but also over the time-scale of the structural changes of NM-TM NPs that indeed occur during PEMFC operation. Moreover, we demonstrate how such a control can be achieved and thereby the performance of PEMFCs improved considerably. Last but not least, we argue that the unique capabilities of in operando HE-XRD coupled to atomic PDF analysis to characterize active nanocatalysts inside operating fuel cells both in a time-resolved manner and with atomic level resolution, i.e. in 4D, can serve well the ongoing search for nanocatalysts that deliver more with less platinum.Here we present the results from a study aimed at clarifying the relationship between the atomic structure and activity of nanocatalysts for chemical reactions driving fuel cells, such as the oxygen reduction reaction (ORR). In particular, using in operando high-energy X-ray diffraction (HE

  7. Micro direct methanol fuel cell with perforated silicon-plate integrated ionomer membrane

    DEFF Research Database (Denmark)

    Larsen, Jackie Vincent; Dalslet, Bjarke Thomas; Johansson, Anne-Charlotte Elisabeth Birgitta

    2014-01-01

    This article describes the fabrication and characterization of a silicon based micro direct methanol fuel cell using a Nafion ionomer membrane integrated into a perforated silicon plate. The focus of this work is to provide a platform for micro- and nanostructuring of a combined current collector...... at a perforation ratio of 40.3%. The presented fuel cells also show a high volumetric peak power density of 2 mW cm−3 in light of the small system volume of 480 μL, while being fully self contained and passively feed....... and catalytic electrode. AC impedance spectroscopy is utilized alongside IV characterization to determine the influence of the plate perforation geometries on the cell performance. It is found that higher ratios of perforation increases peak power density, with the highest achieved being 2.5 mW cm−2...

  8. Performance Degradation Tests of Phosphoric Acid Doped PBI Membrane Based High Temperature PEM Fuel Cells

    DEFF Research Database (Denmark)

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

    2014-01-01

    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. Continuous tests with H2 and simulated reformate which was composed...... of H2, water steam and methanol as the fuel were performed on both single cells. 12-h-startup/12-h-shutdown dynamic tests were performed on the first single cell with pure dry H2 as the fuel and on the second single cell with simulated reformate as the fuel. Along with the tests electrochemical...... techniques such as polarization curves and electrochemical impedance spectroscopy (EIS) were employed to study the degradation mechanisms of the fuel cells. Both single cells showed an increase in the performance in the H2 continuous tests, because of a decrease in the ORR kinetic resistance probably due...

  9. Nano composite membrane-electrode assembly formation for fuel cell-modeling aspects

    Science.gov (United States)

    Vaivars, G.; Linkov, V.

    2007-12-01

    Long term stability is an essential requirement for fuel cell applications in automobile and stationary energy systems. In these systems the agglomeration of the catalyst nanoparticles is a well-known phenomenon which cannot be easily overcome or compensated for by re-designing the system. A direct result of this occurrence is the irreversible decrease of the electrochemical performance. Irregularities in electric field distribution are one root cause for migration and subsequent agglomeration of the catalyst nanoparticle. In this work, the impact of the electrode mechanical deformation on electric field distribution was studied using a computer modeling approach. Model of a Proton Exchange Membrane (PEM) fuel cell with interdigitated flow field from Comsol Chemical Engineering/Electrochemical Engineering Module library was used for simulations. It was established that by minimizing the backing layer deformation it is possible to achieve some improvement in current distribution.

  10. An Equivalent Electrical Circuit Model of Proton Exchange Membrane Fuel Cells Based on Mathematical Modelling

    Directory of Open Access Journals (Sweden)

    Dinh An Nguyen

    2012-07-01

    Full Text Available Many of the Proton Exchange Membrane Fuel Cell (PEMFC models proposed in the literature consist of mathematical equations. However, they are not adequately practical for simulating power systems. The proposed model takes into account phenomena such as activation polarization, ohmic polarization, double layer capacitance and mass transport effects present in a PEM fuel cell. Using electrical analogies and a mathematical modeling of PEMFC, the circuit model is established. To evaluate the effectiveness of the circuit model, its static and dynamic performances under load step changes are simulated and compared to the numerical results obtained by solving the mathematical model. Finally, the applicability of our model is demonstrated by simulating a practical system.

  11. Membrane-less micro fuel cell based on two-phase flow

    Science.gov (United States)

    Hashemi, S. M. H.; Neuenschwander, M.; Hadikhani, P.; Modestino, M. A.; Psaltis, D.

    2017-04-01

    Most microfluidic fuel cells use highly soluble fuels and oxidants in streams of liquid electrolytes to overcome the mass transport limitations that result from the low solubility of gaseous reactants such as hydrogen and oxygen. In this work, we address these limitations by implementing controlled two-phase flows of these gases in a set of microchannels electrolytically connected through a narrow gap. Annular flows of the gases reshape the concentration boundary layer over the surface of electrodes and increase the mass-transport limited current density in the system. Our results show that the power density of a two-phase system with hydrogen and oxygen streams is an order of magnitude higher than that of single phase system consisting of liquid electrolytes saturated with the same reactants. The reactor design described here can be employed to boost the performance of MFFCs and put them in a more competitive position compared to membrane based fuel cells.

  12. Inductive phenomena at low frequencies in impedance spectra of proton exchange membrane fuel cells - A review

    Science.gov (United States)

    Pivac, Ivan; Barbir, Frano

    2016-09-01

    The results of electrochemical impedance spectroscopy of proton exchange membrane (PEM) fuel cells may exhibit inductive phenomena at low frequencies. The occurrence of inductive features at high frequencies is explained by the cables and wires of the test system. However, explanation of inductive loop at low frequencies requires a more detailed study. This review paper discusses several possible causes of such inductive behavior in PEM fuel cells, such as side reactions with intermediate species, carbon monoxide poisoning, and water transport, also as their equivalent circuit representations. It may be concluded that interpretation of impedance spectra at low frequencies is still ambiguous, and that better equivalent circuit models are needed with clearly defined physical meaning of each of the circuit elements.

  13. Experimental and thermodynamic approach on proton exchange membrane fuel cell performance

    Energy Technology Data Exchange (ETDEWEB)

    Miansari, Me. [Islamic Azad University Ghaemshahr, P.O. Box 163, Ghaemshahr (Iran); Sedighi, K.; Alizadeh, E.; Miansari, Mo. [Department of Mechanical Engineering, Noushirvani University of Technology, P.O. Box 484, Babol (Iran); Amidpour, M. [Department of Mechanical Engineering, K.N. Toosi University, Box 15875-4416, Tehran (Iran)

    2009-05-15

    The present work is employed in two sections. Firstly the effect of different parameters such as pressure, temperature and anode and cathode channel depth on the performance of the proton exchange membrane (PEM) fuel cell was experimentally studied. The experimental result shows a good accuracy compared to other works. Secondly a semi-empirical model of the PEM fuel cell has been developed. This model was used to study the effect of different operating conditions such as temperature, pressure and air stoichiometry on the exergy efficiencies and irreversibilities of the cell. The results show that the predicted polarization curves are in good agreement with the experimental data and a high performance was observed at the channel depth of 1.5 mm for the anode and 1 mm for the cathode. Furthermore the results show that increase in the operating temperature and pressure can enhance the cell performance, exergy efficiencies and reduce irreversibilities of the cell. (author)

  14. Experimental and thermodynamic approach on proton exchange membrane fuel cell performance

    Science.gov (United States)

    Miansari, Me.; Sedighi, K.; Amidpour, M.; Alizadeh, E.; Miansari, Mo.

    The present work is employed in two sections. Firstly the effect of different parameters such as pressure, temperature and anode and cathode channel depth on the performance of the proton exchange membrane (PEM) fuel cell was experimentally studied. The experimental result shows a good accuracy compared to other works. Secondly a semi-empirical model of the PEM fuel cell has been developed. This model was used to study the effect of different operating conditions such as temperature, pressure and air stoichiometry on the exergy efficiencies and irreversibilities of the cell. The results show that the predicted polarization curves are in good agreement with the experimental data and a high performance was observed at the channel depth of 1.5 mm for the anode and 1 mm for the cathode. Furthermore the results show that increase in the operating temperature and pressure can enhance the cell performance, exergy efficiencies and reduce irreversibilities of the cell.

  15. Nano composite membrane-electrode assembly formation for fuel cell-modeling aspects

    Energy Technology Data Exchange (ETDEWEB)

    Vaivars, G [Institute of Solid State Physics of University of Latvia, Riga (Latvia); Linkov, V [University of the Western Cape, South African Institute of Advanced Material Chemistry, Cape Town, Western Cape (South Africa)

    2007-12-15

    Long term stability is an essential requirement for fuel cell applications in automobile and stationary energy systems. In these systems the agglomeration of the catalyst nanoparticles is a well-known phenomenon which cannot be easily overcome or compensated for by re-designing the system. A direct result of this occurrence is the irreversible decrease of the electrochemical performance. Irregularities in electric field distribution are one root cause for migration and subsequent agglomeration of the catalyst nanoparticle. In this work, the impact of the electrode mechanical deformation on electric field distribution was studied using a computer modeling approach. Model of a Proton Exchange Membrane (PEM) fuel cell with interdigitated flow field from Comsol Chemical Engineering/Electrochemical Engineering Module library was used for simulations. It was established that by minimizing the backing layer deformation it is possible to achieve some improvement in current distribution.

  16. Preparation of electrolyte membranes for micro tubular solid oxide fuel cells

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Yttria-stabilized zirconia (YSZ) micro tubular electrolyte membranes for solid oxide fuel cells (SOFCs) were prepared via the combined wet phase inversion and sintering technique. The as-derived YSZ mi- cro tubes consist of a thin dense skin layer and a thick porous layer that can serve as the electrode of fuel cells. The dense and the porous electrolyte layers have the thickness of 3-5 μm and 70-90 μm, respectively, while the inner surface porosity of the porous layer is higher than 28.1%. The two layers are perfectly integrated together to preclude the crack or flake of electrolyte film from the electrode. The presented method possesses distinct advantages such as technological simplicity, low cost and high reliability, and thus provides a new route for the preparation of micro tubular SOFCs.

  17. Phosphonic acid functionalized poly(pentafluorostyrene) as polyelectrolyte membrane for fuel cell application

    Science.gov (United States)

    Atanasov, Vladimir; Oleynikov, Andrey; Xia, Jiabing; Lyonnard, Sandrine; Kerres, Jochen

    2017-03-01

    In this paper we introduce polyelectrolyte membranes based on phosphonated poly(pentafluorostyrene) (PPFS) and their performances in a fuel cell. The polyelectrolytes were obtained via partial phosphonation of PPFS varying the phosphonation degree from 17 to 66%. These membranes showed a high resistance to temperature (Tdecomp. = 355-381 °C) and radical attack (96-288 h in Fenton's test). A blend membrane consisting of 82 wt% fully phosphonated PPFS and 18 wt% poly(benzimidazole) is compared to the 66% phosphonated membrane having similar ion-conductivity (σ = 57 mS cm-1 at 120 °C, 90% RH). In the fuel cell the blend showed the best performance reaching 0.40 W cm-2 against 0.34 W cm-2 for the 42 wt% phosphonated membrane and 0.35 W cm-2 for Nafion 212. Furthermore, the blend maintained its operation at potentiostatic regime (0.5 V) for 620 h without declining in its performance. The highest power density of 0.78 W cm-2 was reached for the blend with a thickness of 15 μm using humidified oxygen (RH > 90%) at the cathode side. The switch from humidified to dry gasses during operation reduced the current density down to 0.6 A cm-2, but the cell maintained under operation for 66 h.

  18. 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)

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

    Science.gov (United States)

    Putri, Zufira; Arcana, I. Made

    2014-03-01

    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 SiO2 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 SiO2 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-SiO2 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).

  20. An ultrathin self-humidifying membrane for PEM fuel cell application: fabrication, characterization, and experimental analysis.

    Science.gov (United States)

    Zhu, Xiaobing; Zhang, Huamin; Zhang, Yu; Liang, Yongmin; Wang, Xiaoli; Yi, Baolian

    2006-07-27

    An ultrathin poly(tetrafluoroethylene) (PTFE)-reinforced multilayer self-humidifying composite membrane (20 microm, thick) is developed. The membrane is composed of Nafion-impregnated porous PTFE composite as the central layer, and SiO2 supported nanosized Pt particles (Pt-SiO2) imbedded into the Nafion as the two side layers. The proton exchange membrane (PEM) fuel cell employing the self-humidifying membrane (Pt-SiO2/NP) turns out a peak power density of 1.40 W cm(-2) and an open circuit voltage (OCV) of 1.032 V under dry H2/O2 condition. The excellent performance is attributed to the combined result of both the accelerated water back-diffusion in the thin membrane and the adsorbing/releasing water properties of the Pt-SiO2 catalyst in the side layers. Moreover, the inclusion of the hygroscopic Pt-SiO2 catalyst inside the membrane results in an enhanced anode self-humidification capability and also the decreased cathode polarization (accordingly an improved cell OCV). Several techniques, such as transmission electronic microscopy, scanning electronic microscopy, energy dispersive spectroscopy, thermal analysis and electrochemical impedance spectroscopy etc., are employed to characterize the Pt-SiO2/NP membrane. The results are discussed in comparison with the plain Nafion/PTFE membrane (NP). It is established that the reverse net water drag (from the cathode to the anode) across the Pt-SiO2/NP membrane reaches 0.16 H2O/H+. This implies a good hydration of the Pt-SiO2/NP membrane and thus ensures an excellent PEM fuel cell performance under self-humidification operation.

  1. Catalytic hydrogen/oxygen reaction assisted the proton exchange membrane fuel cell (PEMFC) startup at subzero temperature

    Science.gov (United States)

    Sun, Shucheng; Yu, Hongmei; Hou, Junbo; Shao, Zhigang; Yi, Baolian; Ming, Pingwen; Hou, Zhongjun

    Fuel cells for automobile application need to operate in a wide temperature range including freezing temperature. However, the rapid startup of a proton exchange membrane fuel cell (PEMFC) at subfreezing temperature, e.g., -20 °C, is very difficult. A cold-start procedure was developed, which made hydrogen and oxygen react to heat the fuel cell considering that the FC flow channel was the characteristic of microchannel reactor. The effect of hydrogen and oxygen reaction on fuel cell performance at ambient temperature was also investigated. The electrochemical characterizations such as I- V plot and cyclic voltammetry (CV) were performed. The heat generated rate for either the single cell or the stack was calculated. The results showed that the heat generated rate was proportional to the gas flow rate when H 2 concentration and the active area were constant. The fuel cell temperature rose rapidly and steadily by controlling gas flow rate.

  2. Structural dynamics and activity of nanocatalysts inside fuel cells by in operando atomic pair distribution studies.

    Science.gov (United States)

    Petkov, Valeri; Prasai, Binay; Shan, Shiyao; Ren, Yang; Wu, Jinfang; Cronk, Hannah; Luo, Jin; Zhong, Chuan-Jian

    2016-05-19

    Here we present the results from a study aimed at clarifying the relationship between the atomic structure and activity of nanocatalysts for chemical reactions driving fuel cells, such as the oxygen reduction reaction (ORR). In particular, using in operando high-energy X-ray diffraction (HE-XRD) we tracked the evolution of the atomic structure and activity of noble metal-transition metal (NM-TM) nanocatalysts for ORR as they function at the cathode of a fully operational proton exchange membrane fuel cell (PEMFC). Experimental HE-XRD data were analysed in terms of atomic pair distribution functions (PDFs) and compared to the current output of the PEMFC, which was also recorded during the experiments. The comparison revealed that under actual operating conditions, NM-TM nanocatalysts can undergo structural changes that differ significantly in both length-scale and dynamics and so can suffer losses in their ORR activity that differ significantly in both character and magnitude. Therefore we argue that strategies for reducing ORR activity losses should implement steps for achieving control not only over the length but also over the time-scale of the structural changes of NM-TM NPs that indeed occur during PEMFC operation. Moreover, we demonstrate how such a control can be achieved and thereby the performance of PEMFCs improved considerably. Last but not least, we argue that the unique capabilities of in operando HE-XRD coupled to atomic PDF analysis to characterize active nanocatalysts inside operating fuel cells both in a time-resolved manner and with atomic level resolution, i.e. in 4D, can serve well the ongoing search for nanocatalysts that deliver more with less platinum.

  3. Graphene-Supported Platinum Catalyst-Based Membrane Electrode Assembly for PEM Fuel Cell

    Science.gov (United States)

    Devrim, Yilser; Albostan, Ayhan

    2016-08-01

    The aim of this study is the preparation and characterization of a graphene-supported platinum (Pt) catalyst for proton exchange membrane fuel cell (PEMFC) applications. The graphene-supported Pt catalysts were prepared by chemical reduction of graphene and chloroplatinic acid (H2PtCl6) in ethylene glycol. X-ray powder diffraction, thermogravimetric analysis (TGA) and scanning electron microscopy have been used to analyze structure and surface morphology of the graphene-supported catalyst. The TGA results showed that the Pt loading of the graphene-supported catalyst was 31%. The proof of the Pt particles on the support surfaces was also verified by energy-dispersive x-ray spectroscopy analysis. The commercial carbon-supported catalyst and prepared Pt/graphene catalysts were used as both anode and cathode electrodes for PEMFC at ambient pressure and 70°C. The maximum power density was obtained for the Pt/graphene-based membrane electrode assembly (MEA) with H2/O2 reactant gases as 0.925 W cm2. The maximum current density of the Pt/graphene-based MEA can reach 1.267 and 0.43 A/cm2 at 0.6 V with H2/O2 and H2/air, respectively. The MEA prepared by the Pt/graphene catalyst shows good stability in long-term PEMFC durability tests. The PEMFC cell voltage was maintained at 0.6 V without apparent voltage drop when operated at 0.43 A/cm2 constant current density and 70°C for 400 h. As a result, PEMFC performance was found to be superlative for the graphene-supported Pt catalyst compared with the Pt/C commercial catalyst. The results indicate the graphene-supported Pt catalyst could be utilized as the electrocatalyst for PEMFC applications.

  4. Transport phenomena within the porous cathode for a proton exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Juanfang; Oshima, Nobuyuki; Kurihara, Eru; Saha, Litan Kumar [Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan)

    2010-10-01

    A two-phase, one-dimensional steady model is developed to analyze the coupled phenomena of cathode flooding and mass-transport limiting for the porous cathode electrode of a proton exchange membrane fuel cell. In the model, the catalyst layer is treated not as an interface between the membrane and gas diffusion layer, but as a separate computational domain with finite thickness and pseudo-homogenous structure. Furthermore, the liquid water transport across the porous electrode is driven by the capillary force based on Darcy's law. And the gas transport is driven by the concentration gradient based on Fick's law. Additionally, through Tafel kinetics, the transport processes of gas and liquid water are coupled. From the numerical results, it is found that although the catalyst layer is thin, it is very crucial to better understand and more correctly predict the concurrent phenomena inside the electrode, particularly, the flooding phenomena. More importantly, the saturation jump at the interface of the gas diffusion layer and catalyst layers is captured, when the continuity of the capillary pressure is imposed on the interface. Elsewise, the results show further that the flooding phenomenon in the CL is much more serious than that in the GDL, which has a significant influence on the mass transport of the reactants. Moreover, the saturation level inside the cathode is determined, to a great extent, by the surface overpotential, the absolute permeability of the porous electrode, and the boundary value of saturation at the gas diffusion layer-gas channel interface. In order to prevent effectively flooding, it should remove firstly the liquid water accumulating inside the CL and keep the boundary value of liquid saturation as low as possible. (author)

  5. Reliability prediction of large fuel cell stack based on structure stress analysis

    Science.gov (United States)

    Liu, L. F.; Liu, B.; Wu, C. W.

    2017-09-01

    The aim of this paper is to improve the reliability of Proton Electrolyte Membrane Fuel Cell (PEMFC) stack by designing the clamping force and the thickness difference between the membrane electrode assembly (MEA) and the gasket. The stack reliability is directly determined by the component reliability, which is affected by the material property and contact stress. The component contact stress is a random variable because it is usually affected by many uncertain factors in the production and clamping process. We have investigated the influences of parameter variation coefficient on the probability distribution of contact stress using the equivalent stiffness model and the first-order second moment method. The optimal contact stress to make the component stay in the highest level reliability is obtained by the stress-strength interference model. To obtain the optimal contact stress between the contact components, the optimal thickness of the component and the stack clamping force are optimally designed. Finally, a detailed description is given how to design the MEA and gasket dimensions to obtain the highest stack reliability. This work can provide a valuable guidance in the design of stack structure for a high reliability of fuel cell stack.

  6. Modeling hydrogen starvation conditions in proton-exchange membrane fuel cells

    Science.gov (United States)

    Ohs, Jan Hendrik; Sauter, Ulrich; Maass, Sebastian; Stolten, Detlef

    In this study, a steady state and isothermal 2D-PEM fuel cell model is presented. By simulation of a single cell along the channel and in through-plane direction, its behaviour under hydrogen starvation due to nitrogen dilution is analysed. Under these conditions, carbon corrosion and water electrolysis are observed on the cathode side. This phenomenon, causing severe cell degradation, is known as reverse current decay mechanism in literature. Butler-Volmer equations are used to model the electrochemical reactions. In addition, we account for permeation of gases through the membrane and for the local water content within the membrane. The results show that the membrane potential locally drops in areas starved from hydrogen. This leads to potential gradients >1.2 V between electrode and membrane on the cathode side resulting in significant carbon corrosion and electrolysis reaction rates. The model enables the analysis of sub-stoichiometric states occurring during anode gas recirculation or load transients.

  7. Modeling hydrogen starvation conditions in proton-exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ohs, Jan Hendrik; Sauter, Ulrich; Maass, Sebastian [Robert Bosch GmbH, Robert-Bosch-Platz 1, 70839 Gerlingen-Schillerhoehe (Germany); Stolten, Detlef [Forschungszentrum Juelich GmbH, IEF-3: Fuel Cells, 52425 Juelich (Germany)

    2011-01-01

    In this study, a steady state and isothermal 2D-PEM fuel cell model is presented. By simulation of a single cell along the channel and in through-plane direction, its behaviour under hydrogen starvation due to nitrogen dilution is analysed. Under these conditions, carbon corrosion and water electrolysis are observed on the cathode side. This phenomenon, causing severe cell degradation, is known as reverse current decay mechanism in literature. Butler-Volmer equations are used to model the electrochemical reactions. In addition, we account for permeation of gases through the membrane and for the local water content within the membrane. The results show that the membrane potential locally drops in areas starved from hydrogen. This leads to potential gradients >1.2 V between electrode and membrane on the cathode side resulting in significant carbon corrosion and electrolysis reaction rates. The model enables the analysis of sub-stoichiometric states occurring during anode gas recirculation or load transients. (author)

  8. Microbial fuel cells and osmotic membrane bioreactors have mutual benefits for wastewater treatment and energy production.

    Science.gov (United States)

    Hou, Dianxun; Lu, Lu; Ren, Zhiyong Jason

    2016-07-01

    This study demonstrates that microbial fuel cells (MFCs) and osmotic membrane bioreactors (OMBRs) can be mutually beneficial when integrated together for wastewater treatment. When connecting MFCs with OMBRs, the solute buildup increased conductivity and buffer capacity, which greatly increased MFC power density from 3 W/m(3) up to 11.5 W/m(3). In turn, the MFCs conditioned and reduced sludge production and therefore reduced forward osmosis (FO) membrane fouling. The MFC-OMBR equipped with new thin-film composite (TFC) membrane showed excellent organic (>95%) and phosphorus removal (>99%) and therefore maintained effluent sCOD below 20 mg/L. However, the nitrogen removal was limited due to the negative surface charge of the thin-film composite membrane and solution chemistry, which led to higher flux of ammonium toward the OMBR draw solution. Further studies are needed to improve nitrogen removal, reduce fouling, and optimize system integration.

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

    DEFF Research Database (Denmark)

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

    The electrolyte of choice for low temperature polymer electrolyte fuel cells (PEFCs) has tra­di­ti­o­nal­ly been DuPontTM Nafion® membranes or similar poly(perfluorosulfonic acid)s. The chemical struc­ture and morphology in the hydrated state of Nafion® is shown in figure 1 from which it is seen...... crossover, and relatively poor thermal stability constitute seri­ous drawbacks with respect to their fuel cell use.[ii],[iii],[iv] These aspects propel the search for cheaper and better alternatives.           In this study membrane systems consisting of a hydrophobic poly...... found that crosslinking by divinylbenzene clear­ly improves the chemical stability of both sulfonated styrene- and methylstyrene/t-butylstyrene-grafted ETFE membranes. How­ever, the crosslinking reduces the proton conductivity due to decreased water uptake, thus downgrading the membranes' elec­tro­ly­tic...

  10. New polymeric electrolyte membranes based on proton donor-proton acceptor properties for direct methanol fuel cells

    NARCIS (Netherlands)

    Manea, Carmen; Mulder, Marcel

    2002-01-01

    In order to reduce the high methanol permeability of membranes in a direct methanol fuel cell application new and better materials are still required. In this paper membranes made from polybenzimidazole/sulfonated polysulfone are given and compared with homopolymer membranes made from sulfonated pol

  11. 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

  12. Effect of System Contaminants on the Performance of a Proton Exchange Membrane Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Mehrabadi, Bahareh Alsadat Tavakoli; Dinh, Huyen N.; Bender, Guido; Weidner, John W.

    2016-01-01

    The performance loss and recovery of the fuel cell due to Balance of Plant (BOP) contaminants was identified via a combination of experimental data and a mathematical model. The experiments were designed to study the influence of organic contaminants (e.g. those from BOP materials) on the resistance of the catalyst, ionomer and membrane, and a mathematical model was developed that allowed us to separate these competing resistances from the data collected on an operating fuel cell. For this reason, based on the functional groups, four organic contaminants found in BOP materials, diethylene glycol monoethyl ether (DGMEE), diethylene glycol monoethyl ether acetate (DGMEA), benzyl alcohol (BzOH) and 2,6-diaminotoluene (2,6-DAT) were infused separately to the cathode side of the fuel cell. The cell voltage and high frequency impedance resistance was measured as a function of time. The contaminant feed was then discontinued and voltage recovery was measured. It was determined that compounds with ion exchange properties like 2,6-DAT can cause voltage loss with non-reversible recovery, so this compound was studied in more detail. The degree of voltage loss increased with an increase in concentration, and/or infusion time, and increased with a decrease in catalyst loadings.

  13. Proton Exchange Membrane Fuel Cell Engineering Model Powerplant. Test Report: Benchmark Tests in Three Spatial Orientations

    Science.gov (United States)

    Loyselle, Patricia; Prokopius, Kevin

    2011-01-01

    Proton exchange membrane (PEM) fuel cell technology is the leading candidate to replace the aging alkaline fuel cell technology, currently used on the Shuttle, for future space missions. This test effort marks the final phase of a 5-yr development program that began under the Second Generation Reusable Launch Vehicle (RLV) Program, transitioned into the Next Generation Launch Technologies (NGLT) Program, and continued under Constellation Systems in the Exploration Technology Development Program. Initially, the engineering model (EM) powerplant was evaluated with respect to its performance as compared to acceptance tests carried out at the manufacturer. This was to determine the sensitivity of the powerplant performance to changes in test environment. In addition, a series of tests were performed with the powerplant in the original standard orientation. This report details the continuing EM benchmark test results in three spatial orientations as well as extended duration testing in the mission profile test. The results from these tests verify the applicability of PEM fuel cells for future NASA missions. The specifics of these different tests are described in the following sections.

  14. A new stochastic algorithm for proton exchange membrane fuel cell stack design optimization

    Science.gov (United States)

    Chakraborty, Uttara

    2012-10-01

    This paper develops a new stochastic heuristic for proton exchange membrane fuel cell stack design optimization. The problem involves finding the optimal size and configuration of stand-alone, fuel-cell-based power supply systems: the stack is to be configured so that it delivers the maximum power output at the load's operating voltage. The problem apparently looks straightforward but is analytically intractable and computationally hard. No exact solution can be found, nor is it easy to find the exact number of local optima; we, therefore, are forced to settle with approximate or near-optimal solutions. This real-world problem, first reported in Journal of Power Sources 131, poses both engineering challenges and computational challenges and is representative of many of today's open problems in fuel cell design involving a mix of discrete and continuous parameters. The new algorithm is compared against genetic algorithm, simulated annealing, and (1+1)-EA. Statistical tests of significance show that the results produced by our method are better than the best-known solutions for this problem published in the literature. A finite Markov chain analysis of the new algorithm establishes an upper bound on the expected time to find the optimum solution.

  15. Development of a miniaturized polymer electrolyte membrane fuel cell with silicon separators

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun-Yeop; Kwon, Oh Joong; Hwang, Sun-Mi; Kang, Moo Seong; Kim, Jae Jeong [Research Center for Energy Conversion and Storage, School of Chemical and Biological Engineering, Seoul National University, Shillim-dong, Kwanak-gu, Seoul 151-742 (Korea, Republic of)

    2006-10-20

    The fabrication process and electrochemical characterization of a miniaturized PEM fuel cell with silicon separators were investigated. Silicon separators were fabricated with silicon fabrication technologies such as by photolithography, anisotropic wet etching, anodic bonding and physical vapor deposition (PVD). A 400{mu}mx230{mu}m flow channel was made with KOH wet etching on the front side of a silicon separator, and then a 550nm gold current collector and 350nm TiN{sub x} thin film heater were respectively formed on the front side and the opposite side by PVD. Two separators were assembled with the membrane electrode assembly (MEA) having a 4cm{sup 2} active area for the single cell. With pure hydrogen and oxygen under atmospheric pressure without humidification, the performance of the single fuel cell was measured. A single cell operation led to generation of 203mWcm{sup -2} at 0.6V at room temperature, which corresponded to 360mWcm{sup -3} in terms of volumetric fuel cell power density, with 20ccm of gas flow rate of hydrogen and oxygen at the inlet. (author)

  16. Computational modeling of transport and electrochemical reactions in proton-exchange membrane fuel cells

    Science.gov (United States)

    Um, Sukkee

    A comprehensive, multi-physics computational fuel cell dynamics (CFCD) model integrating electrochemical kinetics, charge transport, mass transport (particularly water transport), and flow dynamics is developed in this thesis. The numerical model is validated against published experimental data and utilized to generate results that reveal the internal operation of a PEM fuel cell. A number of model applications are demonstrated in the present work. First, the CFCD model is applied to explore hydrogen dilution effects in the anode feed. Detailed two-dimensional electrochemical and flow/transport simulations are provided to examine substantial anode concentration polarization due to hydrogen depletion at the reaction sites. A transient simulation of the cell current response to a step change in cell voltage is also attempted to elucidate characteristics of the dynamic response of a fuel cell for the first time. After the two-dimensional computational study, the CFCD model is applied to illustrate three-dimensional interactions between mass transfer and electrochemical kinetics. Emphasis is placed on obtaining a fundamental understanding of fully three-dimensional flow in the air cathode with interdigitated flowfield design and how it impacts the transport and electrochemical reaction processes. The innovative design concept for enhanced oxygen transport to, and effective water removal from the cathode, is explored numerically. Next, an analytical study of water transport is performed to investigate various water transport regimes of practical interest. The axial locations characteristic of anode water loss and cathode flooding are predicted theoretically and compared with numerical results. A continuous stirred fuel cell reactor (CSFCR) model is also proposed for the limiting situation where the anode and cathode sides reach equilibrium in water concentration with a thin ionomer membrane in between. In addition to the analytical solutions, a detailed water transport

  17. 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

  18. Preparation of Sulfonated PVA-TMSP Membranes for Direct Methanol Fuel Cell

    Directory of Open Access Journals (Sweden)

    Haryadi

    2012-08-01

    Full Text Available Novel preparation and characterization of sulfonated polyvinyl alcohol (PVA–trimethoxysilyl propanethiol (TMSP membranes for direct methanol fuel cell (DMFC application have been investigated. Preparation of sulfonated PVA-TMSP membrane was conducted by crosslinking steps using sol-gel method and a catalyst of concentrated HCl. TMSP concentrations were varied from 1% to 3%. The gel solution was cast on to the membrane metal plate to obtain membrane sheets. The membrane was then oxidized in H2O2 concentrations of (10-30% to convert the mercapto groups into sulfonate group. Investigations of the cross-linking process and the existence of sulfonate group were conducted by infrared spectroscopy as shown for frequencies at 1140–1200/cm and 1200–1145/cm respectively. The scanning electron microscope–energy dispersive X-rays (SEM–EDX of the membranes indicated that the distribution of silica particles from sol–gel reaction products was uneven due to the fast exchange rate of condensation. The degree of swelling decreased as methanol concentrations increase for sulfonated PVA–TMSP membrane which opposed toward the value of commercial Nafion membrane. The maximum value of ion exchange capacity of the membrane was 1.82 mmol/g whereas the highest proton conductivity was 3.9 x 10-4 S/cm. Therefore it can be concluded that the membrane was a potential candidate for application in DMFC.

  19. Development of a process for the industrial production of electrodes for polymer electrolyte fuel cells; Verfahrensentwicklung fuer die industrielle Herstellung von Elektroden fuer Polymer-Elektrolyt-Membran Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Jacksch, C.

    2005-06-30

    The automobile companies as well as the manufacturers of stationary fuel cell systems see the necessity to be able to operate polymer electrolyte fuel cells at temperatures above 100 C. Especially for automotive applications the advantages of so called high-temperature systems (operating temperature 100-200 C) compared to so called low temperature systems (operating temperature 70-90 C) are significant. Using polymer membranes whose proton conductivity is almost independent from water, the expenditure of water management for the fuel cell system is zero. There is no need for a complicated moisture-system, which is not easy to handle and which needs quite a lot of space when it is integrated in the car. Operating a fuel cell at higher temperatures also reduces the heat exchange area needed to dissipate the excess heat. This is also a significant advantage for the overall fuel cell system design. Additionally, a higher operating temperature leads to a higher catalytic activity of the fuel cell electrodes and a decreasing proneness of the catalytic material to impurities in the feed. The recent work deals with the development of a manufacturing process for membrane electrode assemblies based on polybenzimidazol membranes for fuel cells operating at higher temperatures. One of the main interests of this work is the optimization of a screenprinting process with the aim of producing electrodes in a reproducible quality; the main requirement for optimizing the electrode structure and the electrode composition. With varying the electrode structure and composition it should be possible to determine the possible performance of the polybenzimidazol/phosphoric acid system. Different characterization methods were used to investigate and to compare different membrane electrode assemblies. These were made of a polybenzimidazol membrane and selfmade or commercially available electrodes. The characterization methods helped to show significant advantages in the behaviour in

  20. Modeling of a Membrane Based Humidifier for Fuel Cell Applications Subject to End-Of-Life Conditions

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh; Olesen, Anders Christian; Menard, Alan

    2014-01-01

    Proton Exchange Membrane (PEM) Fuel Cell Stacks efficiently convert the chemical energy in hydrogen to electricity through electrochemical reactions occurring on either side of a proton conducting electrolyte. This is a promising and very robust energy conversion process which can be used in many...... applications. For instance for automotive applications and various backup power systems substituting batteries. Humidification of the inlet air of PEM fuel cell stacks is essential to obtain optimum proton conductivity. Operational humidities of the anode and cathode streams having dew points close to the fuel...... cell operating temperature are required. These conditions must be met at the Beginning-Of-Life (BOL) as well as at the End-Of-Life (EOL) of the fuel cell system. This paper presents results of a numerical 1D model of the heat- and mass transport phenomena in a membrane humidifier with a Nafion...

  1. Modeling of a Membrane Based Humidifier for Fuel Cell Applications Subject to End-Of-Life Conditions

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh; Olesen, Anders Christian; Menard, Alan

    2014-01-01

    Proton Exchange Membrane (PEM) Fuel Cell Stacks efficiently convert the chemical energy in hydrogen to electricity through electrochemical reactions occurring on either side of a proton conducting electrolyte. This is a promising and very robust energy conversion process which can be used in many...... applications. For instance for automotive applications and various backup power systems substituting batteries. Humidification of the inlet air of PEM fuel cell stacks is essential to obtain optimum proton conductivity. Operational humidities of the anode and cathode streams having dew points close to the fuel...... cell operating temperature are required. These conditions must be met at the Beginning-Of-Life (BOL) as well as at the End-Of-Life (EOL) of the fuel cell system. This paper presents results of a numerical 1D model of the heat- and mass transport phenomena in a membrane humidifier with a Nafion...

  2. Water activities of polymeric membrane/water systems in fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Ji Yun; Bae, Young Chan [Division of Chemical Engineering and Molecular Thermodynamics Laboratory, Hanyang University, Seoul 133-791 (Korea, Republic of); Sun, Yang Kook [Division of Chemical Engineering and Center for Information and Communication Material, Hanyang University, Seoul 133-791 (Korea)

    2006-07-03

    A new equation of state (EOS) is established to describe water activities of polymeric membrane/water systems in fuel cell. It is developed based on the modified perturbed hard-sphere-chain (PHSC) EOS by introducing a new perturbation equation that is obtained from the generalized Lennard-Jones (GLJ) potential function based on a statistical-mechanical relationship. Experimentally observed water activities of polymeric electrolyte/water systems are interpreted by the proposed model. The values calculated from the proposed model are in a good agreement with the experimental data for given systems. (author)

  3. Study on Production of Hydrogen from Methane for Proton Exchange Membrane Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    宋正昶; 李传统

    2001-01-01

    The hydrogen production from methane for proton exchange membrane fuel cell (PEMFC) was studied experimentally. The conversion rate of methane under different steam-carbon ratios, the effect of the different excess air ratios on the constituents of the gas produced, the permeability of hydrogen under different pressure differences, and the effect of different system pressure on the reaction enthalpy of hydrogen were obtained. The results lay the basis for the production of hydrogen applicable to PEMFC, moreover, provide a new way for the comprehensive utilization of the coal bed methane.

  4. Synthesis of the diazonium (perfluoroalkyl) benzenesulfonimide monomer from Nafion monomer for proton exchange membrane fuel cells

    Science.gov (United States)

    Mei, Hua; D'Andrea, Dan; Nguyen, Tuyet-Trinh; Nworie, Chima

    2014-02-01

    One diazonium (perfluoroalkyl) benzenesulfonimide monomer, perfluoro-3, 6-dioxa-4-methyl-7-octene benzenesulfonyl imide, has been synthesized from Nafion monomer for the first time. With trifluorovinyl ether and diazonium precursors, the partially-fluorinated diazonium PFSI monomer can be polymerized and will provide chemically bonding with carbon electrode in proton exchange membrane fuel cells. A systematic study of the synthesis and characterization of this diazonium PFSI monomer has been conducted by varying reaction conditions. The optimized synthesis method has been established in the lab.

  5. Dynamic Control of Electric Output Characteristics of Proton Exchange Membrane Fuel Cell System

    Institute of Scientific and Technical Information of China (English)

    刘星则; 朱新坚

    2005-01-01

    This paper discusses dynamic characteristics of proton exchange membrane fuel cell (PEMFC) under rapid fluctuation of power demand. Wavelet neural network is adopted in the identification of the characteristic curve to predict the voltage. The system control scheme of the voltage and power is introduced. The corresponding schemes for voltage and power control are studied. MATLAB is used to simulate the control system. The results reveal that the adopted control schemes can produce expected effects. Corresponding anti-disturbance and robustness simulation are also carried out. The simulation results show that the implemented control schemes have better robustness and adaptability.

  6. Performance of Cassava Starch as a Proton Exchange Membrane in a Dual Chambered Microbial Fuel Cell.

    OpenAIRE

    Livinus A. Obasi; Charles C. Opara; Akuma Oji

    2012-01-01

    This research work shows the feasibility of power generation in a mediatorless dual chambered microbial fuel cell, utilizing cassava starch as the proton exchange membrane (PEM). The study employed swine house effluent (a serious environmental threat) as the substrate (fuel) (pH, 7.2, BOD: 1200mg/l, COD: 3800mg/l) in the anode chamber prepared with a phosphate buffer solution (K2HPO4+KH2PO4), potassium ferry cyanide solution served as the oxygen acceptor in the cathode chamber using graphite ...

  7. Double cross-linked polyetheretherketone proton exchange membrane for fuel cell

    CSIR Research Space (South Africa)

    Luo, H

    2012-04-01

    Full Text Available permeability and thermal stability have been investigated for fuel cell applications. 2. Experimental 2.1. Materials The catalysts, platinum (40 %) on carbon black (cathode), platinum (30 %)/ruthenium (15 %) on carbon black (anode), Nafion? (5 %) solution.... Luo, S. Ji, G. Vaivars, B. Bladergroen, V. Linkov, South African Journal of Chemistry, 60 (2007) 85-90. [13] P. Xing, G.P. Robertson, M.D. Guiver, S.D. Mikhailenko, K. Wang, S. Kaliaguine, Journal of Membrane Science, 229 (2004) 95-106. Page 10...

  8. Anion exchange membrane based on alkali doped poly(2,5-benzimidazole) for fuel cell

    CSIR Research Space (South Africa)

    Luo, H

    2012-02-01

    Full Text Available @csir.co.za *Manuscript Click here to view linked References 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53... catalyst compared with acidic systems [1] . At the same time, they exhibit faster reaction kinetics enabling higher power densities. In alcohol fed fuel cells they can also better limit fuel cross-over and cost less than proton exchange membrane systems...

  9. Oxygen reduction electrocatalyst in solid polymer fuel cell membrane electrode assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Ralph, T.R.; Keating, J.E.; Collis, N.J.; Hyde, T.I.

    1997-10-01

    The overall objective of the project was to determine the feasibility of achieving a 50 mV cell performance improvement at typical solid polymer fuel cell (SPFC) operating conditions from the application of platinum/base metal alloy electrocatalysts in the cathode. A secondary aim was to resolve the performance enhancement into that due to improved oxygen reduction kinetics and that due to electrode structural effects such as enhanced platinum utilisation. (UK)

  10. Characterization of transport phenomena in small polymer electrolyte membrane fuel cells

    OpenAIRE

    2008-01-01

    In small fuel cell systems, energy consumption and size of auxiliary devices should be minimized. One option is to use passive controlling methods that rely on material and structural solutions. Therefore it is important to understand transport phenomena occurring in the cells. In this thesis, charge, mass, and heat transport phenomena related to small PEMFCs were studied experimentally and by modeling. A new method was developed for the characterization of water transport properties of p...

  11. A graphite-coated carbon fiber epoxy composite bipolar plate for polymer electrolyte membrane fuel cell

    Science.gov (United States)

    Yu, Ha Na; Lim, Jun Woo; Suh, Jung Do; Lee, Dai Gil

    A PEMFC (polymer electrolyte membrane fuel cell or proton exchange membrane fuel cell) stack is composed of GDLs (gas diffusion layers), MEAs (membrane electrode assemblies), and bipolar plates. One of the important functions of bipolar plates is to collect and conduct the current from cell to cell, which requires low electrical bulk and interfacial resistances. For a carbon fiber epoxy composite bipolar plate, the interfacial resistance is usually much larger than the bulk resistance due to the resin-rich layer on the composite surface. In this study, a thin graphite layer is coated on the carbon/epoxy composite bipolar plate to decrease the interfacial contact resistance between the bipolar plate and the GDL. The total electrical resistance in the through-thickness direction of the bipolar plate is measured with respect to the thickness of the graphite coating layer, and the ratio of the bulk resistance to the interfacial contact resistance is estimated using the measured data. From the experiment, it is found that the graphite coating on the carbon/epoxy composite bipolar plate has 10% and 4% of the total electrical and interfacial contact resistances of the conventional carbon/epoxy composite bipolar plate, respectively, when the graphite coating thickness is 50 μm.

  12. Detecting proton exchange membrane fuel cell hydrogen leak using electrochemical impedance spectroscopy method

    Science.gov (United States)

    Mousa, Ghassan; Golnaraghi, Farid; DeVaal, Jake; Young, Alan

    2014-01-01

    When a proton exchange membrane (PEM) fuel cell runs short of hydrogen, it suffers from a reverse potential fault that, when driven by neighboring cells, can lead to anode catalyst degradation and holes in the membrane due to local heat generation. As a result, hydrogen leaks through the electrically-shorted membrane-electrode assembly (MEA) without being reacted, and a reduction in fuel cell voltage is noticed. Such voltage reduction can be detected by using electrochemical impedance spectroscopy (EIS). To fully understand the reverse potential fault, the effect of hydrogen crossover leakage in a commercial MEA is measured by EIS at different differential pressures between the anode and cathode. Then the signatures of these leaky cells were compared with the signatures of a no-leaky cells at different oxygen concentrations with the same current densities. The eventual intent of this early stage work is to develop an on-board diagnostics system that can be used to detect and possibly prevent cell reversal failures, and to permit understanding the status of crossover or transfer leaks versus time in operation.

  13. Analyze of Impedance for Water Management in Proton Exchange Membrane Fuel Cells Using Factorial Design of (DoE) Methodology

    OpenAIRE

    Khaled Mammar; Abdelkader Chaker

    2014-01-01

    Electrochemical impedance spectroscopy (EIS) is a very powerful tool for exploitation as a rich source of Proton Exchange Membrane Fuel Cell (PEMFC) diagnostic information. A primary goal of this work is to develop a suitable PEMFC impedance model, which can be used to analyze flooding and drying of the fuel cell. For this one a novel optimization method based on Factorial Design methodology is used. It was applied to parametric analysis of electrochemical impedance Thus it is pos...

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

    OpenAIRE

    Dietmar Gerteisen; Robert Alink

    2013-01-01

    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 ...

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

    Science.gov (United States)

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

    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.

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

    KAUST Repository

    Hussaini, I.S.

    2010-06-01

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

  17. Performance of Membrane-Assisted Solid Oxide Fuel Cell System Fuelled by Bioethanol

    Directory of Open Access Journals (Sweden)

    Amornchai Arpornwichanop

    2011-04-01

    Full Text Available The membrane separation units for bioethanol purification including pervaporation and vapor permeation are integrated with the bioethanol-fuelled solid oxide fuel cell (SOFC system. The preliminary calculations indicate that Hydrophilic type is a suitable membrane for vapor permeation to be installed after a hydrophobic pervaporation. Based on energy self-sufficient condition and data of available pervaporation membranes, the simulation results show that the use of vapor permeation unit after the pervaporation can significantly improve the overall electrical efficiency from 10.96% for the system with pervaporation alone to 26.56%. Regarding the effect of ethanol recovery, the ethanol recovery at 75% can offer the optimal overall efficiency from the proposed purification system compared to the ethanol recovery at 31.16% for the case with the single pervaporation.

  18. Local area water removal analysis of a proton exchange membrane fuel cell under gas purge conditions.

    Science.gov (United States)

    Lee, Chi-Yuan; Lee, Yu-Ming; Lee, Shuo-Jen

    2012-01-01

    In this study, local area water content distribution under various gas purging conditions are experimentally analyzed for the first time. The local high frequency resistance (HFR) is measured using novel micro sensors. The results reveal that the liquid water removal rate in a membrane electrode assembly (MEA) is non-uniform. In the under-the-channel area, the removal of liquid water is governed by both convective and diffusive flux of the through-plane drying. Thus, almost all of the liquid water is removed within 30 s of purging with gas. However, liquid water that is stored in the under-the-rib area is not easy to remove during 1 min of gas purging. Therefore, the re-hydration of the membrane by internal diffusive flux is faster than that in the under-the-channel area. Consequently, local fuel starvation and membrane degradation can degrade the performance of a fuel cell that is started from cold.

  19. Local Entropy Production Rates in a Polymer Electrolyte Membrane Fuel Cell

    Science.gov (United States)

    Siemer, Marc; Marquardt, Tobias; Valadez Huerta, Gerardo; Kabelac, Stephan

    2017-01-01

    A modeling study on a polymer electrolyte membrane fuel cell by means of non-equilibrium thermodynamics is presented. The developed model considers a one-dimensional cell in steady-state operation. The temperature, concentration and electric potential profiles are calculated for every domain of the cell. While the gas diffusion and the catalyst layers are calculated with established classical modeling approaches, the transport processes in the membrane are calculated with the phenomenological equations as dictated by the non-equilibrium thermodynamics. This approach is especially instructive for the membrane as the coupled transport mechanisms are dominant. The needed phenomenological coefficients are approximated on the base of conventional transport coefficients. Knowing the fluxes and their intrinsic corresponding forces, the local entropy production rate is calculated. Accordingly, the different loss mechanisms can be detected and quantified, which is important for cell and stack optimization.

  20. POLYSULFONE COMPOSED OF POLYANILINE NANOPARTICLES AS NANOCOMPOSITE PROTON EXCHANGE MEMBRANE IN MICROBIAL FUEL CELL

    Directory of Open Access Journals (Sweden)

    Mostafa Ghasemi

    2012-01-01

    Full Text Available Proton exchange membranes play a critical role in the performance of Microbial Fuel Cells (MFCs but their high price was always a big deal for commercialization of MFCs. In the present study, doped and undoped polyaniline nanoparticles/polysulfone nanocomposites membranes as a new type of PEM, were fabricated and applied in the MFC and their performance was compared with Nafion 117 as a traditional and expensive PEM. The obtained results show that MFC working by undoped Pani/Ps generated 78.1 mW/m2 which is higher than doped Pani/Ps system with 62.5 mW/m2. However, Naion 117 generated the highest power than other types of membrane by 93 mW/m2. It means that undoped Pani/Ps can compete in power generation with Nafion 117 and this is an outlook toward commercialization of MFC.

  1. Modified hydrogenated PBLH copolymer synthesis with styrene for proton exchange membranes fuel cell application; Derivados de PBLH hidrogenado na sintese de copolimeros com estireno, para a producao de membranas cationicas para celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Ferraz, Fernando A.; Oliveira, Angelo R.S.; Rodrigues, Maraiza F.; Groetzner, Mariana B.; Cesar-Oliveira, Maria Aparecida F. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica. Lab. de Polimeros Sinteticos (LABPOL)]. E-mails: ferraz@quimica.ufpr.br; angelorsoliveira@ig.com.br; maraiza@quimica.ufpr.br; marianabitt@brasilh2.com.br; mafco@quimica.ufpr.br; Cantao, Mauricio P. [Instituto de Tecnologia para o Desenvolvimento (LACTEC), Curitiba, PR (Brazil)]. E-mail: cantao@lactec.org.br

    2005-07-01

    Polymers used as electrolyte in fuel cells are expected to have functional groups in their structure which are responsible for proton conductivity. Since the use of hydroxylated liquid polybutadiene (PBLH) has not been mentioned in the literature as an ion exchange membrane for fuel cell application (PEMFC), and its structure can be modified for a later sulfonation, it has been studied. In this work, PBLH was modified through a hydrogenation reaction. Furthermore, hydrogenated polymeric esters were obtained by esterification and transesterification reactions (PBLH- estearate and PBLH- methacrylate). Reacting the PBLH methacrylate with styrene, it was generated a copolymer with appropriated structure for sulfonation, justifying researches for fuel cell. (author)

  2. Mass transport of direct methanol fuel cell species in sulfonated poly(ether ether ketone) membranes

    Energy Technology Data Exchange (ETDEWEB)

    Silva, V.S.; Boaventura, M.; Mendes, A.M.; Madeira, L.M. [LEPAE, Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Ruffmann, B.; Vetter, S.; Nunes, S.P. [GKSS Research Centre, Max-Planck Str., 21502 Geesthacht (Germany)

    2006-05-05

    Homogeneous membranes based on sulfonated poly(ether ether ketone) (sPEEK) with different sulfonation degrees (SD) were prepared and characterized. In order to perform a critical analysis of the SD effect on the polymer barrier and mass transport properties towards direct methanol fuel cell species, proton conductivity, water/methanol pervaporation and nitrogen/oxygen/carbon dioxide pressure rise method experiments are proposed. This procedure allows the evaluation of the individual permeability coefficients in hydrated sPEEK membranes with different sulfonation degrees. Nafion{sup (R)} 112 was used as reference material. DMFC tests were also performed at 50{sup o}C. It was observed that the proton conductivity and the permeability towards water, methanol, oxygen and carbon dioxide increase with the sPEEK sulfonation degree. In contrast, the SD seems to not affect the nitrogen permeability coefficient. In terms of selectivity, it was observed that the carbon dioxide/oxygen selectivity increases with the sPEEK SD. In contrast, the nitrogen/oxygen selectivity decreases. In terms of barrier properties for preventing the DMFC reactants loss, the polymer electrolyte membrane based on the sulfonated poly(ether ether ketone) with SD lower or equal to 71%, although having slightly lower proton conductivity, presented much better characteristics for fuel cell applications compared with the well known Nafion{sup (R)} 112. In terms of the DMFC tests of the studied membranes at low temperature, the sPEEK membrane with SD=71% showed to have similar performance, or even better, as that of Nafion{sup (R)} 112. However, the highest DMFC overall efficiency was achieved using sPEEK membrane with SD=52%. (author)

  3. Fuel cell catalyst degradation

    DEFF Research Database (Denmark)

    Arenz, Matthias; Zana, Alessandro

    2016-01-01

    Fuel cells are an important piece in our quest for a sustainable energy supply. Although there are several different types of fuel cells, the by far most popular is the proton exchange membrane fuel cell (PEMFC). Among its many favorable properties are a short start up time and a high power density...

  4. Experimental Investigation and Discussion on the Mechanical Endurance Limit of Nafion Membrane Used in Proton Exchange Membrane Fuel Cell

    Directory of Open Access Journals (Sweden)

    Yang Xiao

    2014-10-01

    Full Text Available As a solution of high efficiency and clean energy, fuel cell technologies, especially proton exchange membrane fuel cell (PEMFC, have caught extensive attention. However, after decades of development, the performances of PEMFCs are far from achieving the target from the Department of Energy (DOE. Thus, further understanding of the degradation mechanism is needed to overcome this obstacle. Due to the importance of proton exchange membrane in a PEMFC, the degradation of the membrane, such as hygrothermal aging effect on its properties, are particularly necessary. In this work, a thick membrane (Nafion N117, which is always used as an ionic polymer for the PEMFCs, has been analyzed. Experimental investigation is performed for understanding the mechanical endurance of the bare membranes under different loading conditions. Tensile tests are conducted to compare the mechanical property evolution of two kinds of bare-membrane specimens including the dog-bone and the deeply double edge notched (DDEN types. Both dog-bone and DDEN specimens were subjected to a series of degradation tests with different cycling times and wide humidity ranges. The tensile tests are repeated for both kinds of specimens to assess the strain-stress relations. Furthermore, Fourier transform infrared spectroscopy (FT-IR, X-ray diffraction (XRD and Scanning electron microscope (SEM observation and water absorption measurement were conducted to speculate the cause of this variation. The initial cracks along with the increasing of bound water content were speculated as the primary cause.

  5. Optimization of fuel cell membrane electrode assemblies for transition metal ion-chelating ordered mesoporous carbon cathode catalysts

    Directory of Open Access Journals (Sweden)

    Johanna K. Dombrovskis

    2014-12-01

    Full Text Available Transition metal ion-chelating ordered mesoporous carbon (TM-OMC materials were recently shown to be efficient polymer electrolyte membrane fuel cell (PEMFC catalysts. The structure and properties of these catalysts are largely different from conventional catalyst materials, thus rendering membrane electrode assembly (MEA preparation parameters developed for conventional catalysts not useful for applications of TM-OMC catalysts. This necessitates development of a methodology to incorporate TM-OMC catalysts in the MEA. Here, an efficient method for MEA preparation using TM-OMC catalyst materials for PEMFC is developed including effects of catalyst/ionomer loading and catalyst/ionomer-mixing and application procedures. An optimized protocol for MEA preparation using TM-OMC catalysts is described.

  6. Optimization of fuel cell membrane electrode assemblies for transition metal ion-chelating ordered mesoporous carbon cathode catalysts a

    Science.gov (United States)

    Dombrovskis, Johanna K.; Prestel, Cathrin; Palmqvist, Anders E. C.

    2014-12-01

    Transition metal ion-chelating ordered mesoporous carbon (TM-OMC) materials were recently shown to be efficient polymer electrolyte membrane fuel cell (PEMFC) catalysts. The structure and properties of these catalysts are largely different from conventional catalyst materials, thus rendering membrane electrode assembly (MEA) preparation parameters developed for conventional catalysts not useful for applications of TM-OMC catalysts. This necessitates development of a methodology to incorporate TM-OMC catalysts in the MEA. Here, an efficient method for MEA preparation using TM-OMC catalyst materials for PEMFC is developed including effects of catalyst/ionomer loading and catalyst/ionomer-mixing and application procedures. An optimized protocol for MEA preparation using TM-OMC catalysts is described.

  7. Improved performance of single-chamber microbial fuel cells through control of membrane deformation

    KAUST Repository

    Zhang, Xiaoyuan

    2010-03-01

    Cation (CEMs) and anion exchange membrane (AEMs) are commonly used in microbial fuel cells (MFCs) to enhance Coulombic efficiencies (CEs) by reducing thefluxof oxygen through the cathode to bacteriaonthe anode. AEMs typically work better than CEMs, but in initial experiments we observed the opposite using a membrane electrode assembly MFC. The reason was identified to be membrane deformation, which resulted in water and gas trapped between the membrane and cathode. To correct this, stainless steel mesh was used to press the membrane flat against the cathode. With the steel mesh, AEM performance increased to 46±4W/m3 in a single cathode MFC, and 98±14W/m3 in a double-cathode MFC. These power densities were higher than those using a CEM of 32±2W/m3 (single cathode) and 63±6W/m3 (double cathode). Higher pH gradients across the membrane and salt precipitation on the cathode were responsible for the reduced performance of the CEM compared to the AEM. CEs reached over 90% for both membranes at >2A/m2. These results demonstrate the importance of avoiding water accumulation in thin films between membranes and electrodes, and explain additional reasons for poorer performance of CEMs compared to AEMs. © 2009 Elsevier B.V.

  8. State-of-the-art in bipolar of proton exchange membrane fuel cell

    Science.gov (United States)

    Wang, Yun; Wang, Jingjing; Yin, Bi-feng; Xu, Zhen-ying; Ding, Sheng

    2010-10-01

    Proton exchange membrane fuel cell (PEMFC) has been the research focus because of the characteristics of compact structure, low-temperature starting, high specific energy density and power, environmental protection, prolonged service time. The bipolar plate in PEMFC has the function of isolating and uniformly distributing reactants, removing reaction products, collecting and inducing current, providing mechanical support for the cells in the stack collects, etc. The bipolar plate, which influences not only the cell stack performance but also the stack cost, is a vital component of PEMFC that is the choke point of industrialization. Compared with the conventional graphite bipolar plate, the metallic bipolar plate has the advantages of excellent electrical and thermal conductivity, high mechanical strength and power density, no leakage and good workability. Furthermore, the metal plate is especially suitable for production in mass. Therefore, metallic bipolar plate is considered to be a promising alternative for PEMFC bipolar. A review of the research work involves the material selection and processing of bipolar plate, flow-field type and the corresponding design, the forming methods of metallic bipolar plates. The materials of bipolar plate for PEMFC are focused on graphite, metal or alloy, and all kinds of composite materials. The disadvantages and advantages of these materials are compared. The flow channels of bipolar include dot-type, web-type, serpentine-type and the interdigital shape. Among them, serpentine-type flow channel plates are mentioned in detail. In this paper, we introduced the forming methods of metallic bipolar plates such as the electrochemical micro-fabrication, electroforming, thermoforming, micro-stamping and micro-milling. Finally, it points out that the prospective research about the PEMFC is minimization and industrialization.

  9. Realization of Both High-Performance and Enhanced Durability of Fuel Cells: Pt-Exoskeleton Structure Electrocatalysts.

    Science.gov (United States)

    Kim, Ok-Hee; Cho, Yoon-Hwan; Jeon, Tae-Yeol; Kim, Jung Won; Cho, Yong-Hun; Sung, Yung-Eun

    2015-07-01

    Core-shell structure nanoparticles have been the subject of many studies over the past few years and continue to be studied as electrocatalysts for fuel cells. Therefore, many excellent core-shell catalysts have been fabricated, but few studies have reported the real application of these catalysts in a practical device actual application. In this paper, we demonstrate the use of platinum (Pt)-exoskeleton structure nanoparticles as cathode catalysts with high stability and remarkable Pt mass activity and report the outstanding performance of these materials when used in membrane-electrode assemblies (MEAs) within a polymer electrolyte membrane fuel cell. The stability and degradation characteristics of these materials were also investigated in single cells in an accelerated degradation test using load cycling, which is similar to the drive cycle of a polymer electrolyte membrane fuel cell used in vehicles. The MEAs with Pt-exoskeleton structure catalysts showed enhanced performance throughout the single cell test and exhibited improved degradation ability that differed from that of a commercial Pt/C catalyst.

  10. Scale-up of a high temperature polymer electrolyte membrane fuel cell based on polybenzimidazole

    Science.gov (United States)

    Pinar, F. Javier; Cañizares, Pablo; Rodrigo, Manuel A.; Úbeda, Diego; Lobato, Justo

    A high temperature PEM fuel cell stack with a total active area 150 cm 2 has been studied. The PEM technology is based on a polybenzimidazole (PBI) membrane. Cast from a PBI polymer synthesised in our lab, the performance of a three-cell stack was analysed in static and dynamic modes. In static mode, operating at high constant oxygen flow rate (QO2 > 1105 ml O2 / min) produces a small decrease on the stack performance. High constant oxygen stoichiometry (λO2 > 3) does not produce a decrease on the performance of the stack. There are not differences between operating at constant flow rate of oxygen and constant stoichiometry of oxygen in the stack performance. The effect of operating at high temperature with a pressurization system and operating at higher temperatures are beneficial since the performance of the fuel cell is enhanced. A large shut-down stage produces important performance losses due to the loss of catalyst activity and the loss of membrane conductivity. After 150 h of operation at 0.2 A cm -2, it is observed a very high voltage drop. The phosphoric acid leached from the stack was also evaluated and did not exceed 2% (w/w). This fact suggests that the main degradation mechanism of a fuel cell stack based on polybenzimidazole is not the electrolyte loss. In dynamic test mode, it was observed a rapid response of power and current output even at the lower step-time (10 s). In the static mode at 125 °C and 1 atm, the stack reached a power density peak of 0.29 W cm -2 (43.5 W) at 1 V.

  11. Transient computation fluid dynamics modeling of a single proton exchange membrane fuel cell with serpentine channel

    Science.gov (United States)

    Hu, Guilin; Fan, Jianren

    The proton exchange membrane fuel cell (PEMFC) has become a promising candidate for the power source of electrical vehicles because of its low pollution, low noise and especially fast startup and transient responses at low temperatures. A transient, three-dimensional, non-isothermal and single-phase mathematical model based on computation fluid dynamics has been developed to describe the transient process and the dynamic characteristics of a PEMFC with a serpentine fluid channel. The effects of water phase change and heat transfer, as well as electrochemical kinetics and multicomponent transport on the cell performance are taken into account simultaneously in this comprehensive model. The developed model was employed to simulate a single laboratory-scale PEMFC with an electrode area about 20 cm 2. The dynamic behavior of the characteristic parameters such as reactant concentration, pressure loss, temperature on the membrane surface of cathode side and current density during start-up process were computed and are discussed in detail. Furthermore, transient responses of the fuel cell characteristics during step changes and sinusoidal changes in the stoichiometric flow ratio of the cathode inlet stream, cathode inlet stream humidity and cell voltage are also studied and analyzed and interesting undershoot/overshoot behavior of some variables was found. It was also found that the startup and transient response time of a PEM fuel cell is of the order of a second, which is similar to the simulation results predicted by most models. The result is an important guide for the optimization of PEMFC designs and dynamic operation.

  12. Graphene oxide based nanohybrid proton exchange membranes for fuel cell applications: An overview.

    Science.gov (United States)

    Pandey, Ravi P; Shukla, Geetanjali; Manohar, Murli; Shahi, Vinod K

    2017-02-01

    In the context of many applications, such as polymer composites, energy-related materials, sensors, 'paper'-like materials, field-effect transistors (FET), and biomedical applications, chemically modified graphene was broadly studied during the last decade, due to its excellent electrical, mechanical, and thermal properties. The presence of reactive oxygen functional groups in the grapheme oxide (GO) responsible for chemical functionalization makes it a good candidate for diversified applications. The main objectives for developing a GO based nanohybrid proton exchange membrane (PEM) include: improved self-humidification (water retention ability), reduced fuel crossover (electro-osmotic drag), improved stabilities (mechanical, thermal, and chemical), enhanced proton conductivity, and processability for the preparation of membrane-electrode assembly. Research carried on this topic may be divided into protocols for covalent grafting of functional groups on GO matrix, preparation of free-standing PEM or choice of suitable polymer matrix, covalent or hydrogen bonding between GO and polymer matrix etc. Herein, we present a brief literature survey on GO based nano-hybrid PEM for fuel cell applications. Different protocols were adopted to produce functionalized GO based materials and prepare their free-standing film or disperse these materials in various polymer matrices with suitable interactions. This review article critically discussed the suitability of these PEMs for fuel cell applications in terms of the dependency of the intrinsic properties of nanohybrid PEMs. Potential applications of these nanohybrid PEMs, and current challenges are also provided along with future guidelines for developing GO based nanohybrid PEMs as promising materials for fuel cell applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Evaluation of sulphonated polycarbonate membranes for fuel cells; Avaliacao de membranas de policarbonato sulfonado para celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Isabela M.M.; Gomes, Ana C.; Pessan, Luiz A. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Engenharia de Materiais], e-mail: isabelamuglia@gmail.com; Paranhos, Caio [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2011-07-01

    Fuel cells based on ion conducting polymer membranes offer an alternative for the conventional energetic matrices. Among many advantages of this system, we can mention the reduction on the emission of pollutants, high efficiency and simplicity. This work presents the modification of polycarbonate by sulfonation reaction using acetyl sulfate, in order to increase the conductor ionic character of the membranes used as electrolytes for hydrogen fuel cells. The sulfonated polycarbonate membranes were obtained by casting and then characterized by Fourier transform infrared spectroscopy, water vapor transmission, differential scanning calorimetry, thermogravimetric analysis and viscosimetry. (author)

  14. Crosslinking of polybenzimidazolemembranes by divinylsulfone post-treatment for high-temperature proton exchange membrane fuel cell applications

    DEFF Research Database (Denmark)

    Aili, David; Li, Qingfeng; Christensen, Erik;

    2011-01-01

    Phosphoric acid-doped polybenzimidazole (PBI) has been suggested as a promising electrolyte for proton exchangemembrane fuel cells operating at temperatures up to 200 ◦C. This paper describes the development of a crosslinking procedure for PBI membranes by post-treatment with divinylsulfone....... The crosslinking chemistry was studied and optimized on a low-molecularweight model system and the results were used to optimize the crosslinking conditions of PBI membranes. The crosslinked membraneswere characterized with respect to chemical and physiochemical properties, showing improved mechanical strength...... and oxidative stability compared with their linear analogues. Fuel cell tests were further conducted in order to demonstrate the feasibility of the crosslinked membranes....

  15. Synthesis of polymers for proton exchange membrane fuel cell; Synthese de polymeres pour membranes echangeuses de protons

    Energy Technology Data Exchange (ETDEWEB)

    Balland-Longeau, A.; Leninivin, C.; Pereira, F. [CEA Centre d' Etudes du Ripault, 37 - Tours (France)

    2006-05-15

    In the field of fuel cell application, the CEA - DAM has an important contribution in the development of new polymers for protonic conductor membranes. The specifications imposed are very strict in term of mechanical, thermal and chemical properties, in term of protonic conductivity, and for the performances in fuel cell. We have developed new types of per-fluorinated sulfonated polymers starting from poly-para-phenylenes (PPP). New PPP are developed using organometallic chemistry. In this article, we present the synthesis used to prepare these polymers and the very new approach allowing to insert protonic conductor chains (sulfonated and per-fluorinated sulfonated) into the polymers PPP, in the most homogeneous way. (authors)

  16. Enhanced water removal in a fuel cell stack by droplet atomization using structural and acoustic excitation

    Science.gov (United States)

    Palan, Vikrant; Shepard, W. Steve

    This work examines new methods for enhancing product water removal in fuel cell stacks. Vibration and acoustic based methods are proposed to atomize condensed water droplets in the channels of a bipolar plate or on a membrane electrode assembly (MEA). The vibration levels required to atomize water droplets of different sizes are first examined using two different approaches: (1) exciting the droplet at the same energy level required to form that droplet; and (2) by using a method called 'vibration induced droplet atomization', or VIDA. It is shown analytically that a 2 mm radius droplet resting on a bipolar-like plate can be atomized by inducing acceleration levels as low as 250 g at a certain frequency. By modeling the direct structural excitation of a simplified bipolar plate using a realistic source, the response levels that can be achieved are then compared with those required levels. Furthermore, a two-cell fuel cell finite element model and a boundary element model of the MEA were developed to demonstrate that the acceleration levels required for droplet atomization may be achieved in both the bipolar plate as well as the MEA through proper choice of excitation frequency and source strength.

  17. Enhanced water removal in a fuel cell stack by droplet atomization using structural and acoustic excitation

    Energy Technology Data Exchange (ETDEWEB)

    Palan, Vikrant; Shepard, W. Steve [Department of Mechanical Engineering, The University of Alabama, 290 Hardaway Hall, Box 870276, Tuscaloosa, AL 35487 (United States)

    2006-09-22

    This work examines new methods for enhancing product water removal in fuel cell stacks. Vibration and acoustic based methods are proposed to atomize condensed water droplets in the channels of a bipolar plate or on a membrane electrode assembly (MEA). The vibration levels required to atomize water droplets of different sizes are first examined using two different approaches: (1) exciting the droplet at the same energy level required to form that droplet; and (2) by using a method called 'vibration induced droplet atomization', or VIDA. It is shown analytically that a 2mm radius droplet resting on a bipolar-like plate can be atomized by inducing acceleration levels as low as 250g at a certain frequency. By modeling the direct structural excitation of a simplified bipolar plate using a realistic source, the response levels that can be achieved are then compared with those required levels. Furthermore, a two-cell fuel cell finite element model and a boundary element model of the MEA were developed to demonstrate that the acceleration levels required for droplet atomization may be achieved in both the bipolar plate as well as the MEA through proper choice of excitation frequency and source strength. (author)

  18. Characterization of Polyethylene-Graft-Sulfonated Polyarylsulfone Proton Exchange Membranes for Direct Methanol Fuel Cell Applications

    Directory of Open Access Journals (Sweden)

    Hyung Kyu Kim

    2015-12-01

    Full Text Available This paper examines polymer film morphology and several important properties of polyethylene-graft-sulfonated polyarylene ether sulfone (PE-g-s-PAES proton exchange membranes (PEMs for direct methanol fuel cell applications. Due to the extreme surface energy differences between a semi-crystalline and hydrophobic PE backbone and several amorphous and hydrophilic s-PAES side chains, the PE-g-s-PAES membrane self-assembles into a unique morphology, with many proton conductive s-PAES channels embedded in the stable and tough PE matrix and a thin hydrophobic PE layer spontaneously formed on the membrane surfaces. In the bulk, these membranes show good mechanical properties (tensile strength >30 MPa, Young’s modulus >1400 MPa and low water swelling (λ < 15 even with high IEC >3 mmol/g in the s-PAES domains. On the surface, the thin hydrophobic and semi-crystalline PE layer shows some unusual barrier (protective properties. In addition to exhibiting higher through-plane conductivity (up to 160 mS/cm than in-plane conductivity, the PE surface layer minimizes methanol cross-over from anode to cathode with reduced fuel loss, and stops the HO• and HO2• radicals, originally formed at the anode, entering into PEM matrix. Evidently, the thin PE surface layer provides a highly desirable protecting layer for PEMs to reduce fuel loss and increase chemical stability. Overall, the newly developed PE-g-s-PAES membranes offer a desirable set of PEM properties, including conductivity, selectivity, mechanical strength, stability, and cost-effectiveness for direct methanol fuel cell applications.

  19. Microblock ionomers: a new concept in high temperature, swelling-resistant membranes for PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Z. [Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD (United Kingdom); Thompsett, D.; Petrucco, E. [Johnson Matthey Technology Centre, Blounts Court, Sonning Common, Reading, RG4 9NH (United Kingdom); Walsby, N.M.; Colquhoun, H.M.

    2009-08-15

    A novel series of polyaromatic ionomers with similar equivalent weights but very different sulphonic acid distributions along the ionomer backbone has been designed and prepared. By synthetically organising the sequence-distribution so that it consists of fully defined ionic segments (containing singlets, doublets or quadruplets of sulphonic acid groups) alternating strictly with equally well-defined nonionic spacer segments, a new class of polymers which may be described as microblock ionomers has been developed. These materials exhibit very different properties and morphologies from analogous randomly substituted systems. Progressively extending the nonionic spacer length in the repeat unit (maintaining a constant equivalent weight by increasing the degree of sulphonation of the ionic segment) leads to an increasing degree of nanophase separation between hydrophilic and hydrophobic domains in these materials. Membranes cast from ionomers with the more highly phase-separated morphologies show significantly higher onset temperatures for uncontrolled swelling in water. This new type of ionomer design has enabled the fabrication of swelling-resistant hydrocarbon membranes, suitable for fuel cell operation, with very much higher ion exchange capacities (>2 meq g{sup -1}) than those previously reported in the literature. When tested in a fuel cell at high temperature (120 C) and low relative humidity (35% RH), the best microblock membrane matched the performance of Nafion 112. Moreover, comparative low load cycle testing of membrane -electrode assemblies suggests that the durability of the new membranes under conditions of high temperature and low relative humidity is superior to that of conventional perfluorinated materials. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  20. Rejuvenation of automotive fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Seung; Langlois, David A.

    2016-08-23

    A process for rejuvenating fuel cells has been demonstrated to improve the performance of polymer exchange membrane fuel cells with platinum/ionomer electrodes. The process involves dehydrating a fuel cell and exposing at least the cathode of the fuel cell to dry gas (nitrogen, for example) at a temperature higher than the operating temperature of the fuel cell. The process may be used to prolong the operating lifetime of an automotive fuel cell.

  1. Nonlinear robust control of proton exchange membrane fuel cell by state feedback exact linearization

    Energy Technology Data Exchange (ETDEWEB)

    Li, Q.; Chen, W. [School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, Sichuan Province (China); Wang, Y.; Jia, J. [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue 639798, Singapore (Singapore); Han, M. [School of Engineering, Temasek Polytechnic, Tampines 529757, Singapore (Singapore)

    2009-10-20

    By utilizing the state feedback exact linearization approach, a nonlinear robust control strategy is designed based on a multiple-input multiple-output (MIMO) dynamic nonlinear model of proton exchange membrane fuel cell (PEMFC). The state feedback exact linearization approach can achieve the global exact linearization via the nonlinear coordinate transformation and the dynamic extension algorithm such that H{sub {infinity}} robust control strategy can be directly utilized to guarantee the robustness of the system. The proposed dynamic nonlinear model is tested by comparing the simulation results with the experimental data in Fuel Cell Application Centre in Temasek Polytechnic. The comprehensive results of simulation manifest that the dynamic nonlinear model with nonlinear robust control law has better transient and robust stability when the vehicle running process is simulated. The proposed nonlinear robust controller will be very useful to protect the membrane damage by keeping the pressure deviations as small as possible during large disturbances and prolong the stack life of PEMFC. (author)

  2. A multi-objective optimisation model for a general polymer electrolyte membrane fuel cell system

    Science.gov (United States)

    Ang, Sheila Mae C.; Brett, Daniel J. L.; Fraga, Eric S.

    This paper presents an optimisation model for a general polymer electrolyte membrane (PEM) fuel cell system suitable for efficiency and size trade-offs investigation. Simulation of the model for a base case shows that for a given output power, a more efficient system is bigger and vice versa. Using the weighting method to perform a multi-objective optimisation, the Pareto sets were generated for different stack output powers. A Pareto set, presented as a plot of the optimal efficiency and area of the membrane electrode assembly (MEA), gives a quantitative description of the compromise between efficiency and size. Overall, our results indicate that, to make the most of the size-efficiency trade-off behaviour, the system must be operated at an efficiency of at least 40% but not more than 47%. Furthermore, the MEA area should be at least 3 cm 2 W -1 for the efficiency to be practically useful. Subject to the constraints imposed on the model, which are based on technical practicalities, a PEM fuel cell system such as the one presented in this work cannot operate at an efficiency above 54%. The results of this work, specifically the multi-objective model, will form a useful and practical basis for subsequent techno-economic studies for specific applications.

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

    Science.gov (United States)

    Martin, S.; Li, Q.; Steenberg, T.; Jensen, J. O.

    2014-12-01

    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 absence of the polymer in the catalytic layer turned out to be beneficial for the PBI cell performance particularly under high load operation. The influence on performance of the Pt loading of the cathode was studied in a range from 0.11 to 2.04 mgPt cm-2 showing saturation of the maximum performance for Pt loadings higher than 0.5 mgPt cm-2. For fuel cell operation on H2 and air supplied under ambient pressure, a peak power density as high as 471 mW cm-2 was measured. The tolerance to carbon monoxide (CO) was also studied with Pt loadings of the anode ranging from 0.24 to 1.82 mgPt cm-2. Lifetime test for a MEA loaded with 0.96 mgPt cm-2 on both electrodes revealed no voltage decay during 900 h of uninterrupted operation at 200 mA cm-2 and 160 °C.

  4. Design and simulation of novel flow field plate geometry for proton exchange membrane fuel cells

    Science.gov (United States)

    Ruan, Hanxia; Wu, Chaoqun; Liu, Shuliang; Chen, Tao

    2016-10-01

    Bipolar plate is one of the many important components of proton exchange membrane fuel cell (PEMFC) stacks as it supplies fuel and oxidant to the membrane-electrode assembly (MEA), removes water, collects produced current and provides mechanical support for the single cells in the stack. The flow field design of a bipolar plate greatly affects the performance of a PEMFC. It must uniformly distribute the reactant gases over the MEA and prevent product water flooding. This paper aims at improving the fuel cell performance by optimizing flow field designs and flow channel configurations. To achieve this, a novel biomimetic flow channel for flow field designs is proposed based on Murray's Law. Computational fluid dynamics based simulations were performed to compare three different designs (parallel, serpentine and biomimetic channel, respectively) in terms of current density distribution, power density distribution, pressure distribution, temperature distribution, and hydrogen mass fraction distribution. It was found that flow field designs with biomimetic flow channel perform better than that with convectional flow channel under the same operating conditions.

  5. Preparation of a self-humidifying membrane electrode assembly for fuel cell and its performance analysis

    Institute of Scientific and Technical Information of China (English)

    王诚; 毛宗强; 徐景明; 谢晓峰; 杨立寨

    2003-01-01

    A novel nano-porous material SiO2-gel was prepared. After being purified by H2O2, then protonized by H2SO4 and desiccated in vacuum, the SiO2-gel, mixed with Nafion solution, was coated between an electrode and a solid electrolyte, which made a new type of self-humidifying membrane electrode assembly. The SiO2 powder was characterized by FTIR, BET and XRD. The surface of the electrodes was characterized by SEM and EDS. The performances of the self-hu- midifying membrane electrodes were analyzed by polarization discharge and AC impedance under the operation modes of external humidification and self-humidification respectively. Experimental results indicated that the SiO2 powder held super-hydrophilicity, and the layer of SiO2 and Nafion polymer between electrode and solid electrolyte expanded three-dimension electrochemistry reaction area, maintained stability of catalyst layer and enhanced back-diffusion of water from cathode to anode, so the PEM Fuel cell can generate electricity at self-humidification mode. The power density of single PEM fuel cell reached 1.5 W/cm2 under 0.2 Mpa, 70℃ and dry hydrogen and oxygen.

  6. Single-wall carbon nanotube-based proton exchange membrane assembly for hydrogen fuel cells.

    Science.gov (United States)

    Girishkumar, G; Rettker, Matthew; Underhile, Robert; Binz, David; Vinodgopal, K; McGinn, Paul; Kamat, Prashant

    2005-08-30

    A membrane electrode assembly (MEA) for hydrogen fuel cells has been fabricated using single-walled carbon nanotubes (SWCNTs) support and platinum catalyst. Films of SWCNTs and commercial platinum (Pt) black were sequentially cast on a carbon fiber electrode (CFE) using a simple electrophoretic deposition procedure. Scanning electron microscopy and Raman spectroscopy showed that the nanotubes and the platinum retained their nanostructure morphology on the carbon fiber surface. Electrochemical impedance spectroscopy (EIS) revealed that the carbon nanotube-based electrodes exhibited an order of magnitude lower charge-transfer reaction resistance (R(ct)) for the hydrogen evolution reaction (HER) than did the commercial carbon black (CB)-based electrodes. The proton exchange membrane (PEM) assembly fabricated using the CFE/SWCNT/Pt electrodes was evaluated using a fuel cell testing unit operating with H(2) and O(2) as input fuels at 25 and 60 degrees C. The maximum power density obtained using CFE/SWCNT/Pt electrodes as both the anode and the cathode was approximately 20% better than that using the CFE/CB/Pt electrodes.

  7. Direct borohydride fuel cell: Main issues met by the membrane-electrodes-assembly and potential solutions

    Science.gov (United States)

    Demirci, Umit B.

    The direct borohydride fuel cell (DBFC) is a fuel cell for which there is consensus about its promising commercial future as a portable power system. However, its development faces three main issues: the borohydride hydrolysis (issue 1) and crossover (issue 2), and the cost (issue 3). These issues are encountered by the membrane-electrodes-assembly. By a discussion around these three issues, the present paper reviews the experimental aspects. The discussion stresses on the opportunities of improvements and reviews the potential solutions that are proposed in the open literature. For each issue, the best solution seems to be a combination of improvements. The issue 1 may be solved thanks to a gold-based anode catalyst and an optimized fuel. The solution to the issue 2 may be a more efficient membrane combined with an optimized fuel and an inactive-towards-borohydride cathode catalyst like MnO 2. Regarding the issue 3, cheaper materials and better fuel use efficiency are the keys. The DBFC is still in a development phase with a small number of years of R&D invested and it appears that there are real improvement opportunities on the path of the DBFC marketing.

  8. PREPARATION AND PROPERTIES OF SPAES-TiO_2 HYBRID MEMBRANES FOR DIRECT METHANOL FUEL CELL

    Institute of Scientific and Technical Information of China (English)

    Ni Zhang; Hui-ling Liu; Jun-jing Li; Zhi Xia

    2009-01-01

    Sulfonated poly(arylene ether sulfone) (SPAES) copolymer with degree of sulfonation of 1.0 was synthesized and characterized. A series of SPAES-TiO_2 hybrid membranes with various contents of nano-sized TiO_2 particles were prepared and characterized through sol-gel reactions. Scanning electron microscopy (SEM) images indicated the TiO_2 particles were well dispersed within polymer matrix. These composite membranes were evaluated for proton exchange membranes (PEMs) in direct methanol fuel cell (DMFC). These membranes showed good thermal stability and mechanical properties. It was found that the water uptake of these membranes increased with the increase of the TiO_2 contents in the hybrid membranes. Meanwhile, the introduction of inorganic particles increased the proton conductivity and reduced the methanol permeability. The proton conductivities (0.118-0.162 S/cm) of SPAES-TiO_2 hybrid membranes with 8% TiO_2 particles are much higher than those of Nation 117 membrane (0.095-0.117 S/cm) and pure SPAES membrane (0.100-0.124 S/cm) with degree of sulfonation of 1.0 at all temperatures (25-100℃). Especially, the methanol diffusion coefficient (8.4×10~(-7) cm~2/s) of SPAES-TiO_2 hybrid membranes with 8% TiO_2 is much lower than that of Nation 117 membrane (2.1 ×10~(-6) cm~2/s). SPAES-TiO_2 hybrid membranes were therefore proposed as candidates of material for PEM in DMFC.

  9. Promising aquivion composite membranes based on fluoroalkyl zirconium phosphate for fuel cell applications.

    Science.gov (United States)

    Donnadio, Anna; Pica, Monica; Subianto, Surya; Jones, Deborah J; Cojocaru, Paula; Casciola, Mario

    2014-08-01

    Layered zirconium phosphate (ZP) that bears fluorinated alkyl chains bonded covalently to the layers (ZPR) was used as a nanofiller in membranes based on a short-side-chain perfluorosulfonic acid (PFSA) to mechanically reinforce the PFSA hydrophobic component. Compared to the pristine PFSA, membranes with a ZPR loading up to 30 wt% show enhanced mechanical properties, and the largest improvement of elastic modulus (E) and yield stress (σY ) are observed for the 10 wt% ZPR membrane: ΔE/E up to 90% and ΔσY /σY up 70% at 70°C and 80% relative humidity (RH). In the RH range 50-95%, the in-plane conductivity of the composite membranes reaches 0.43 S cm(-1) for 10 wt% ZPR at 110°C and is on average 30% higher than the conductivity of the pristine PFSA. The 10 wt % ZPR membrane is as hydrated as the neat PFSA membrane at 50% RH but becomes progressively less hydrated with increasing RH both at 80 and 110°C. The fuel cell performance of this membrane, at 80°C and 30% RH, is better than that of the unmodified PFSA.

  10. A Nafion-Ceria Composite Membrane Electrolyte for Reduced Methanol Crossover in Direct Methanol Fuel Cells

    Directory of Open Access Journals (Sweden)

    Parthiban Velayutham

    2017-02-01

    Full Text Available An alternative Nafion composite membrane was prepared by incorporating various loadings of CeO2 nanoparticles into the Nafion matrix and evaluated its potential application in direct methanol fuel cells (DMFCs. The effects of CeO2 in the Nafion matrix were systematically studied in terms of surface morphology, thermal and mechanical stability, proton conductivity and methanol permeability. The composite membrane with optimum filler content (1 wt. % CeO2 exhibits a proton conductivity of 176 mS·cm−1 at 70 °C, which is about 30% higher than that of the unmodified membrane. Moreover, all the composite membranes possess a much lower methanol crossover compared to pristine Nafion membrane. In a single cell DMFC test, MEA fabricated with the optimized composite membrane delivered a peak power density of 120 mW·cm−2 at 70 °C, which is about two times higher in comparison with the pristine Nafion membrane under identical operating conditions.

  11. Nafion/PTFE composite membranes for direct methanol fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Hsiu-Li; Yu, T. Leon; Chen, Li-Chung [Department of Chemical Engineering and Materials Science, Yuan Ze University, Nei-Li, Taoyuan 32026 (Taiwan); Huang, Li-Ning; Shen, Kun-Sheng; Jung, Guo-Bin [Fuel Cell Center, Yuan Ze University, Nei-Li, Taoyuan 32026 (Taiwan)

    2005-10-04

    Using dynamic light scattering and scanning electron microscope (SEM), it is shown that a high-carbon-number alcohol/water, i.e., 2-propanol/water, mixed solvent is more effective than low-carbon-number alcohol/water, i.e., ethanol/water and methanol/water, mixed solvents in dispersing Nafion molecules. Thus, it is a better solvent for the preparation of Nafion/PTFE (poly(tetrafluoroethylene)) composite membranes. The performance of direct methanol fuel cells (DMFCs) with a Nafion/PTFE composite membrane, which was prepared in-house, a commercial Nafion-117 membrane, or a commercial Nafion-112 membrane were investigated by feeding various concentrations, i.e., 2-5M, of methanol to the anode. The Nafion/PTFE composite membrane gave a better DMFC performance than that obtained with Nafion-117 or Nafion-112 membranes. Using a DMFC model and varying the methanol concentration at the anode, cell voltage data were analyzed with respect to methanol concentration and cell current. The results indicate that inserting porous PTFE into Nafion polymer causes a reduction not only in methanol diffusion cross-over but also in the electro-osmosis of methanol cross-over in the membrane. (author)

  12. Preparation and characterisation of porous poly(2,5benzimidazole) (ABPBI) membranes using surfactants as templates for polymer electrolyte membrane fuel cells

    CSIR Research Space (South Africa)

    Zheng, H

    2010-04-01

    Full Text Available properties on mechanical strengths, thermal stability and electrochemical performance when compared with those of the original ABPBI membrane, suggestive of a promising polymer electrolyte for fuel cells at high temperature....

  13. Development of Novel PEM Membrane and Multiphase CD Modeling of PEM Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    K. J. Berry; Susanta Das

    2009-12-30

    To understand heat and water management phenomena better within an operational proton exchange membrane fuel cell's (PEMFC) conditions, a three-dimensional, two-phase computational fluid dynamic (CFD) flow model has been developed and simulated for a complete PEMFC. Both liquid and gas phases are considered in the model by taking into account the gas flow, diffusion, charge transfer, change of phase, electro-osmosis, and electrochemical reactions to understand the overall dynamic behaviors of species within an operating PEMFC. The CFD model is solved numerically under different parametric conditions in terms of water management issues in order to improve cell performance. The results obtained from the CFD two-phase flow model simulations show improvement in cell performance as well as water management under PEMFCs operational conditions as compared to the results of a single phase flow model available in the literature. The quantitative information obtained from the two-phase model simulation results helped to develop a CFD control algorithm for low temperature PEM fuel cell stacks which opens up a route in designing improvement of PEMFC for better operational efficiency and performance. To understand heat and water management phenomena better within an operational proton exchange membrane fuel cell's (PEMFC) conditions, a three-dimensional, two-phase computational fluid dynamic (CFD) flow model has been developed and simulated for a complete PEMFC. Both liquid and gas phases are considered in the model by taking into account the gas flow, diffusion, charge transfer, change of phase, electro-osmosis, and electrochemical reactions to understand the overall dynamic behaviors of species within an operating PEMFC. The CFD model is solved numerically under different parametric conditions in terms of water management issues in order to improve cell performance. The results obtained from the CFD two-phase flow model simulations show improvement in cell

  14. Low energy plasma treatment of a proton exchange membrane used for low temperature fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Charles, C [Space Plasma, Power, and Propulsion group, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Ramdutt, D [Space Plasma, Power, and Propulsion group, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Brault, P [GREMI-CNRS Laboratory, University of Orleans, BP 6744, F-45067, Orleans (France); Caillard, A [Space Plasma, Power, and Propulsion group, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Bulla, D [Space Plasma, Power, and Propulsion group, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Boswell, R [Space Plasma, Power, and Propulsion group, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Rabat, H [GREMI-CNRS Laboratory, University of Orleans, BP 6744, F-45067, Orleans (France); Dicks, A [School of Engineering, University of Queensland, Brisbane, QLD 4072 (Australia)

    2007-05-15

    A low energy ({approx}30 V) plasma treatment of Nafion, a commercial proton exchange membrane used for low temperature fuel cells, is performed in a helicon radiofrequency (13.56 MHz) plasma system. For argon densities in the 10{sup 9}-10{sup 10} cm{sup -3} range, the water contact angle (hydrophobicity) of the membrane surface linearly decreases with an increase in the plasma energy dose, which is maintained below 5.1 J cm{sup -2}, and which results from the combination of an ion energy dose (up to 3.8 J cm{sup -2}) and a photon (mostly UV) energy dose (up to 1.3 J cm{sup -2}). The decrease in water contact angle is essentially a result of the energy brought to the surface by ion bombardment. The measured effect of the energy brought to the surface by UV light is found to be negligible.

  15. Low energy plasma treatment of a proton exchange membrane used for low temperature fuel cells

    Science.gov (United States)

    Charles, C.; Ramdutt, D.; Brault, P.; Caillard, A.; Bulla, D.; Boswell, R.; Rabat, H.; Dicks, A.

    2007-05-01

    A low energy (~30 V) plasma treatment of Nafion, a commercial proton exchange membrane used for low temperature fuel cells, is performed in a helicon radiofrequency (13.56 MHz) plasma system. For argon densities in the 109-1010 cm-3 range, the water contact angle (hydrophobicity) of the membrane surface linearly decreases with an increase in the plasma energy dose, which is maintained below 5.1 J cm-2, and which results from the combination of an ion energy dose (up to 3.8 J cm-2) and a photon (mostly UV) energy dose (up to 1.3 J cm-2). The decrease in water contact angle is essentially a result of the energy brought to the surface by ion bombardment. The measured effect of the energy brought to the surface by UV light is found to be negligible.

  16. Electric power generation by a submersible microbial fuel cell equipped with a membrane electrode assembly

    DEFF Research Database (Denmark)

    Min, Booki; Poulsen, Finn Willy; Thygesen, Anders

    2012-01-01

    , the maximum power density was 631mW/m2 at current density of 1772mA/m2 at 82Ω. With 180-Ω external resistance, one set of the electrodes on the same side could generate more power density of 832±4mW/m2 with current generation of 1923±4mA/m2. The anode, inclusive a biofilm behaved ohmic, whereas a Tafel type...... behavior was observed for the oxygen reduction. The various impedance contributions from electrodes, electrolyte and membrane were analyzed and identified by electrochemical impedance spectroscopy. Air flow rate to the cathode chamber affected microbial voltage generation, and higher power generation......Membrane electrode assemblies (MEAs) were incorporated into the cathode chamber of a submersible microbial fuel cell (SMFC). A close contact of the electrodes could produce high power output from SMFC in which anode and cathode electrodes were connected in parallel. In polarization test...

  17. Estimation of Membrane Hydration Status for Standby Proton Exchange Membrane Fuel Cell Systems by Impedance Measurement: First Results on Stack Characterization

    DEFF Research Database (Denmark)

    Bidoggia, Benoit; Kær, Søren Knudsen

    Fuel cells have started replacing traditional lead-acid battery banks in backup systems. Although these systems are characterized by long periods of standby, they must be able to start at any instant in the shortest time. In the case of low temperature proton exchange membrane fuel cell systems...... was applied, and the relationship between module of impedance and relative humidity was found. The results showed that measuring the impedance of a fuel cell during standby can be a viable way for estimating the hydration status of its membrane....

  18. A review of water management in polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ji, M.; Wei, Z. [State Key Laboratory of Power Transmission Equipment and System Security and New Technology, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044 (China)

    2009-07-01

    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 and the gas diffusion layer 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. (author)

  19. 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.

  20. High temperature polymer electrolyte membrane fuel cell performance of Pt xCo y/C cathodes

    Science.gov (United States)

    Rao, Ch. Venkateswara; Parrondo, Javier; Ghatty, Sundara L.; Rambabu, B.

    Carbon-supported Pt-Co alloy nanoparticles of varying Pt:Co atomic ratios of 1:1, 2:1, 3:1 and 4:1 are prepared, characterized and tested in high temperature PEM fuel cell intend to reduce the Pt loading. These electrocatalysts are prepared by borohydride reduction method in the presence of citric acid as stabilizing agent. Face-centered cubic structure of Pt is evident from XRD. The positive shift of Pt diffraction peaks with increasing cobalt content in the Pt xCo y/C catalysts indicated the solubility of Co in Pt lattice. The average crystallite size is found to be 6 nm in all the prepared catalysts. The electrochemical active surface area (EAS) of the catalysts from CO-stripping voltammetry is calculated to be 65.2, 51.4, 47.7, 41.5 and 38.3 m 2 g -1 Pt for Pt/C, Pt-Co(4:1)/C, Pt-Co(3:1)/C, Pt-Co(2:1)/C and Pt-Co(1:1)/C, respectively. These catalysts are used as cathode in the fabrication of polybenzimidazole-based membrane electrode assembly (MEA) and the polarization curves are recorded at 160 and 180 °C. The results indicate the good performance of Pt-Co alloys than that of Pt under the PEM fuel cell conditions. Among the investigated electrocatalysts, Pt-Co(1:1)/C and Pt-Co(2:1)/C exhibited good fuel cell performance. Durability tests also indicated the good stability of Pt-Co(1:1)/C and Pt-Co(2:1)/C compared to Pt/C.

  1. Thermal signature and thermal conductivities of PEM fuel cells; PEM = Proton Exchange Membrane

    Energy Technology Data Exchange (ETDEWEB)

    Burheim, Odne Stokke

    2009-11-15

    of the motivations for the thermal model of the fuel cell was to demonstrate the importance of measuring the through-plane thermal conductivity of fuel cell components. An apparatus for these measurements was constructed and is reported in the presented work. Using K-type thermocouples and digital micrometers together, the apparatus had the possibility to measure the variables in Fourier's law; the heat flux through the sample, the temperature difference over the sample and its thickness. The thermal conductivity of Nafion was measured at room temperature as a function of water content; found to be 0.177 +- 0.008 and 0.254 +- 0.016 W K-1 m-1 for dry and maximally wetted membranes respectively. The membrane thickness and thermal conductivity showed no response to increased compaction pressure. The thermal conductivity of the chosen PTL was measured both dry and saturated with liquid water at different compaction pressures. The chosen PTL's through-plane thermal conductivities were measured to be 0.27, 0.36 and 0.40 W K-l m-1 at 4.6, 9.3 and 13.9 bar compaction pressure respectively. By saturating the PTL with liquid water, the thermal conductivity increased up to 70 %. By measuring the thickness of the uncompressed PTL, it was observed that the thickness changed by 70 mum depending on the location on the PTL. This corresponds to more than ten percent relatively speaking. Having used the model to see the effects rising from manipulating some of the experimentally measured data, several commercial PTLs were gathered and measured in order to create a small database of through-plane thermal conductivities and thermal contact resistivity. Depending on the brand, compaction pressure, Teflon content and liquid water content the material conductivity and thermal contact resistivity were found to be 0.15-1.6 W K-1 m-1 and 0.7 - 11.1 10-4 K m2 W-1, respectively. Though some efforts exists, both experimental and theoretical, there is yet no data collection concerning

  2. Hydroquinone based sulfonated poly (arylene ether sulfone copolymer as proton exchange membrane for fuel cell applications

    Directory of Open Access Journals (Sweden)

    V. Kiran

    2015-12-01

    Full Text Available Synthesis of sulfonated poly (arylene ether sulfone copolymer by direct copolymerization of 4,4'-bis(4-hydroxyphenyl valeric acid, benzene 1,4-diol and synthesized sulfonated 4,4'-difluorodiphenylsulfone and its characterization by using FTIR (Fourier Transform Infrared and NMR (Nuclear Magnetic Resonance spectroscopic techniques have been performed. The copolymer was subsequently cross-linked with 4, 4!(hexafluoroisopropylidenediphenol epoxy resin by thermal curing reaction to synthesize crosslinked membranes. The evaluation of properties showed reduction in water and methanol uptake, ion exchange capacity, proton conductivity with simultaneous enhancement in oxidative stability of the crosslinked membranes as compared to pristine membrane. The performance of the membranes has also been evaluated in terms of thermal stability, morphology, mechanical strength and methanol permeability by using Thermo gravimetric analyzer, Differential scanning calorimetery, Atomic force microscopy, XPERT-PRO diffractometer, universal testing machine and diffusion cell, respectively. The results demonstrated that the crosslinked membranes exhibited high thermal stability with phase separation, restrained crystallinity, acceptable mechanical properties and methanol permeability. Therefore, these can serve as promising proton exchange membranes for fuel cell applications.

  3. Portable proton exchange membrane fuel-cell systems for outdoor applications

    Science.gov (United States)

    Oszcipok, M.; Zedda, M.; Hesselmann, J.; Huppmann, M.; Wodrich, M.; Junghardt, M.; Hebling, C.

    A hydrogen fuelled, 30 W proton exchange membrane fuel-cell (PEMFC) system is presented that is able to operate at an ambient temperature between -20 and 40 °C. The system, which comprises the fuel-cell stack, pumps, humidifier, valves and blowers is fully characterized in a climatic chamber under various ambient temperatures. Successful cold start-up and stable operation at -20 °C are reported as well as the system behaviour during long-term at 40 °C. A simple thermal model of the stack is developed and validated, and accounts for heat losses by radiation and convection. Condensation of steam is addressed as well as reaction gas depletion. The stack is regarded as a uniform heat source. The electrochemical reaction is not resolved. General design rules for the cold start-up of a portable fuel-cell stack are deduced by the thermal model and are taken into consideration for the design. The model is used for a comparison between active-assisted cold start-up procedures with a passive cold start-up from temperatures below 0 °C. It is found that a passive cold start-up may not be the most efficient strategy. Additionally, the influence of different stack concepts on the start-up behaviour is analysed by the thermal model. Three power classes of PEMFC stacks are compared: a Ballard Mk902 module for automotive applications with 85 kW, the forerunner stack Ballard Mk5 (5 kW) for medium power applications, and the developed OutdoorFC stack (30 W), for portable applications.

  4. Plasma membranes modified by plasma treatment or deposition as solid electrolytes for potential application in solid alkaline fuel cells.

    Science.gov (United States)

    Reinholdt, Marc; Ilie, Alina; Roualdès, Stéphanie; Frugier, Jérémy; Schieda, Mauricio; Coutanceau, Christophe; Martemianov, Serguei; Flaud, Valérie; Beche, Eric; Durand, Jean

    2012-07-30

    In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane.

  5. Plasma Membranes Modified by Plasma Treatment or Deposition as Solid Electrolytes for Potential Application in Solid Alkaline Fuel Cells

    Directory of Open Access Journals (Sweden)

    Christophe Coutanceau

    2012-07-01

    Full Text Available In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane.

  6. Stabilized composite membranes and membrane electrode assemblies for high temperature/low relative humidity polymer electrolyte fuel cell operation

    Science.gov (United States)

    Ramani, Vijay Krishna

    Polymer electrolyte membrane fuel cells (PEMFCs) have a variety of applications in the stationary power, mobile power and automotive power sectors. Existing membrane technology presently permits fuel cell operation at temperatures less than 100°C under fully saturated conditions. However, several advantages such as easier heat rejection rates and improved impurities tolerance by the anode electrocatalyst result by operating a PEMFC at elevated temperatures (above 100°C) and lower relative humidities. In an attempt to extend the operating range of the polymer electrolyte membrane, perfluorosulfonic acid (NafionRTM) based organic/inorganic (heteropolyacid) composite membranes were investigated in terms of thermal and electrochemical stability, additive stability and conductivity. Tungsten based heteropolyacids (HPAs) were found to be electrochemically stable as opposed to molybdenum based additives. The stability of the inorganic heteropolyacid additive in aqueous environments was enhanced by ion exchanging the protons of the HPAs with larger counter ions. An additional stabilization technique developed involved improving the interaction of HPA with NafionRTM by linking the particles to the sulfonic acid clusters via a sol-gel induced metal oxide linkage. The proton conductivity of the composite membranes was found to depend on the particle size of the HPA additive. A two order of magnitude change in additive particle size was attained by modification of the membrane preparation technique. This modification resulted in a nearly 50% increase in conductivity. The membranes prepared were characterized by thermal analysis, spectroscopy and microscopy. A technique was developed to incorporate existing MEA preparation and HPA stabilization techniques to the composite membranes with small HPA particles. All MEAs prepared were evaluated at high temperatures (120°C) and low relative humidities (35%) in an operating fuel cell, with membrane resistance and hence conductivity

  7. Mechanisms and modeling development of water transport/phase change in catalyst layers of portion exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Yexiang [Dept. of Thermal Engineering, Tsinghua University Beijing (China)], email: Yexiang.Xiao@energy.lth.se; Yuan, Jinliang; Sunden, Bengt [Dept. of Energy Sciences, Faculty of Engineering, Lund University (Sweden)], email: Jinliang.yuan@energy.lth.se, email: bengt.sunden@energy.lth.se

    2011-07-01

    Research on proton exchange membrane fuel cells has shown that incorporation of nanosized catalysts can effectively increase active areas and catalyst activity and make a great contribution to development in performance and catalyst utilization. Multiphase transport processes are as significant and complicated as water generation/transfer processes which occur in nano-structured catalyst layers. A review project has been launched aimed at gaining a comprehensive understanding of the mechanisms of water generation or transport phenomena. It covers catalytic reactions and water-phase change within the catalyst layers. The review proceeds in three main stages: Firstly, it characterizes and reconstructs the nano/micro-structured pores and solid-phases; secondly, it emphasises the importance of sensitive and consistent analysis of various water-phase change and transport schemes; and thirdly, it recommends development of microscopic models for multi-phase transport processes in the pores and the solid phases.

  8. The applications of 3D-hexagonal mesoporous SiO2 in proton exchange membranes of fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, B.; Tang, H.; Pan, M.; Chen, L.; Liang, C. [Wuhan Univ. of Technology, Wuhan (China). State Key Laboratory of Advanced Technology for Materials Synthesis and Processing

    2010-07-01

    The advantages of 3D hexagonal ordered mesoporous silica include a homogeneous ordered pore, a large surface area, narrow pore size distribution and excellent thermal stability. Hetropolyacids (HPAs) are high conductivity solid proton conductors that can be loaded onto the channel of mesoporous silica as a carrier for the proton exchange membrane of fuel cells. In this study, an ordered 3D hexagonal structure HPW/SiO{sub 2} nano composite materials was prepared using the sol-gel method with a nonionic surfactant (Brij-76) as the template. The HPW/SiO{sub 2} composite was characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption-desorption. The study showed that the synthesis method can effectively make the HPW disperse uniformly in mesoporous framework, ensuring that the synthesized material has ordered mesoscopic structure. Impedance analysis revealed that the HPW/silica nano-materials have good proton conductivity without humidification at room temperature.

  9. Development of a Low-Cost, Durable Membrane and Membrane Electrode Assemby for Stationary and Mobile Fuel Cell Applications

    Energy Technology Data Exchange (ETDEWEB)

    Foure, Michel; Gaboury, Scott; Goldbach, Jim; Mountz, David; Yi, Jung

    2008-01-31

    The development of low cost, durable membranes and membranes electrode assemblies (MEAs) remain a critical challenge for the successful introduction of fuel cells into mass markets. It was the goal of the team lead by Arkema, Inc. (formerly Atofina, Inc.) to address these shortages. Thus, this project addresses the following technical barriers from the Fuel Cells section of the Hydrogen Fuel Cells and Infrastructure Technologies Program Multi-Year Research, Development and Demonstration Plan: (A) Durability (B) Cost Arkema’s approach consisted in using blends of polyvinylidenefluoride (PVDF) and proprietary sulfonated polyelectrolytes. The strength and originality of Arkema’s approach lies in the decoupling of ion conductivity from the other requirements. Kynar® (Arkema trade name for PVDF) provides an exceptional combination of properties that make it ideally suited for a membrane matrix. In a first phase, Arkema demonstrated the feasibility of the concept with the M31 membrane generation. After MEA optimization, it was shown that the beginning-of-life (BOL) performance of M31 MEAs was essentially on a par with that of PFSA MEAs at 60ºC under fully humidified conditions. On the other hand, long-term durability studies showed a high decay rate of 45µV/h over a 2100 hr. test. Arkema then designed several families of polyelectrolyte candidates, which, in principle, could not undergo the same failure mechanisms. A new membrane candidate was developed: M41. It offered the same generally good mechanical, ex-situ conductivity and gas barrier properties as M31. In addition, ex-situ accelerated testing suggested a several orders of magnitude improvement in chemical stability. M41 based MEAs showed comparable BOL performance with that of PFSA (80ºC, 100% RH). M41 MEAs were further shown to be able to withstand several hours temperature excursions at 120ºC without apparent damage. Accelerated studies were carried out using the DOE and/or US Fuel Cell Council

  10. Boundary model-based reference control of blower cooled high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Jensen, Hans-Christian Becker; Kær, Søren Knudsen

    2011-01-01

    Fuel cells have, by design, a limited effective life time, which depends on how they are operated. The general consent is that operation of the fuel cell at the extreme of the operational range, or operation of the fuel cell without sufficient reactants (a.k.a. starvation), will lower the effective...... life time of a fuel cell significantly. On air cooled HTPEMFCs, the blower, which supplies the fuel cell with oxygen for the chemical process, also functions as the cooling system. This makes the blower bi-functional and as a result a higher supply of oxygen is often available, hence changes...... in the fuel cell output can be optimised by the knowledge of how much oxygen is supplied to the fuel cell at any given time, without reducing the effective life time of a fuel cell by starvation....

  11. Boundary model-based reference control of blower cooled high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Jensen, Hans-Christian Becker; Kær, Søren Knudsen

    2011-01-01

    Fuel cells have, by design, a limited effective life time, which depends on how they are operated. The general consent is that operation of the fuel cell at the extreme of the operational range, or operation of the fuel cell without sufficient reactants (a.k.a. starvation), will lower the effective...... life time of a fuel cell significantly. On air cooled HTPEMFCs, the blower, which supplies the fuel cell with oxygen for the chemical process, also functions as the cooling system. This makes the blower bi-functional and as a result a higher supply of oxygen is often available, hence changes...... in the fuel cell output can be optimised by the knowledge of how much oxygen is supplied to the fuel cell at any given time, without reducing the effective life time of a fuel cell by starvation....

  12. Synthesizing 2D MoS2 Nanofins on carbon nanospheres as catalyst support for Proton Exchange Membrane Fuel Cells

    Science.gov (United States)

    Hu, Yan; Chua, Daniel H. C.

    2016-06-01

    Highly dense 2D MoS2 fin-like nanostructures on carbon nanospheres were fabricated and formed the main catalyst support structure in the oxygen reduction reaction (ORR) for polymer electrolyte membrane (PEM) fuel cells. These nanofins were observed growing perpendicular to the carbon nanosphere surface in random orientations and high resolution transmission electron microscope confirmed 2D layers. The PEM fuel cell test showed enhanced electrochemical activity with good stability, generating over 8.5 W.mgPt-1 as compared to standard carbon black of 7.4 W.mgPt-1 under normal operating conditions. Electrochemical Impedance Spectroscopy confirmed that the performance improvement is highly due to the excellent water management of the MoS2 lamellar network, which facilitates water retention at low current density and flood prevention at high current density. Reliability test further demonstrated that these nanofins are highly stable in the electrochemical reaction and is an excellent ORR catalyst support.

  13. Research on proton exchange membrane fuel cell%质子交换膜燃料电池研究

    Institute of Scientific and Technical Information of China (English)

    章晖

    2015-01-01

    Proton exchange membrane fuel cell(PEMFC) has an extensive application respective in EV, portable electronic device, stationary power plant and special power with the advantages of high energy conversion efficiency and quick startup at ambient temperature. The technology and mechanism of PEMFC was researched, and its structure defects were analyzed. It is concluded that to research novel catalysts with high activity and excellent stability is very important for the future fuel cell.%质子交换膜燃料电池(PEMFC)因无电解质腐蚀问题,能量转换效率高,可室温快速启动,在电动车、便携式电子设备、固定电站和军用特种电源等方面都有广阔的应用前景。研究了质子交换膜燃料电池实用化的技术及机理,对其结构缺陷进行了分析,认为开拓新的催化剂体系,合成出活性更高、稳定性更好的催化剂对于燃料电池来说意义重大。

  14. A critical review on gas diffusion micro and macroporous layers degradations for improved membrane fuel cell durability

    Science.gov (United States)

    Lapicque, Francois; Belhadj, Mariem; Bonnet, Caroline; Pauchet, Joël; Thomas, Yohann

    2016-12-01

    Formerly considered as a secondary component of fuel cell, gas diffusion layers (GDLs) have been shown to have a key role in gas transport to the catalyst layers and in water management: in particular, the microporous layer (MPL) deposited on the diffusion substrate has an active part in water distribution in the membrane electrode assembly and in its efficient removal from the cell. In addition to its perfect design for the targeted application and in combination with the macroporous substrate (MPS), the MPL structure and physicochemical properties have to contribute to the cell durability, which is still considered as insufficient for larger, massive commercialisation of this energy conversion system. The paper is aimed at reviewing the main knowledge gained on the role of the MPL on GDL operation and durability, with investigation of degradation phenomena of both MPL and MPS, together with the role played by the MPL in mitigating the occurrence of degradation phenomena that can occur in the whole fuel cell. In addition to the reviewing purpose, original data on ex-situ degradation of GDL are presented.

  15. Thermal and water management of low temperature Proton Exchange Membrane Fuel Cell in fork-lift truck power system

    DEFF Research Database (Denmark)

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

    2013-01-01

    A general zero-dimensional Proton Exchange Membrane Fuel Cell (PEMFC) model has been developed for forklift truck application. The balance of plant (BOP) comprises of a compressor, an air humidifier, a set of heat exchangers and a recirculation pump. Water and thermal management of the fuel cell...... voltage when membrane is fully hydrated otherwise it causes a drastic voltage drop in the stack. Furthermore, by substituting liquid water with water-ethylene glycol mixture of 50%, the mass flow of coolant increases by about 32-33% in the inner loop and 60-65% in the outer loop for all ranges of current...

  16. Enhanced performance of anion exchange membranes via crosslinking of ion cluster regions for fuel cells

    Science.gov (United States)

    Lai, Ao Nan; Guo, Dong; Lin, Chen Xiao; Zhang, Qiu Gen; Zhu, Ai Mei; Ye, Mei Ling; Liu, Qing Lin

    2016-09-01

    Development of anion exchange membranes (AEMs) with high hydroxide conductivity, good dimensional and alkaline stabilities is still a challenge for the practical application of AEM fuel cells. In this study, we report a new strategy to prepare high-performance AEMs with crosslinked ionic regions. A series of phenolphthalein-containing poly(arylene ether sulfone)s crosslinked AEMs was synthesized by grafting ion groups selectively and densely on the phenolphthalein units to form ion clusters that are further crosslinked to generate the hydrophilic ionic regions. The crosslinking reaction not only improved the dimensional stability of the AEMs, but also increased the aggregation of the ion clusters leading to the formation of hydrophilic/hydrophobic phase-separated morphology and ion-conducting channels. As a result, enhancements in both ion conductivity and dimensional stability can be achieved. The crosslinked AEMs showed high hydroxide conductivities in the range of 52.2-143.4 mS cm-1 from 30 to 80 °C and a superb ratio of relative conductivity to relative swelling at 80 °C. Furthermore, the crosslinked AEMs also exhibited good mechanical properties, thermal and alkaline stabilities and desirable single cell performance. This work presents a promising strategy for the synthesis of high-performance AEMs for fuel cells.

  17. A review of fault tolerant control strategies applied to proton exchange membrane fuel cell systems

    Science.gov (United States)

    Dijoux, Etienne; Steiner, Nadia Yousfi; Benne, Michel; Péra, Marie-Cécile; Pérez, Brigitte Grondin

    2017-08-01

    Fuel cells are powerful systems for power generation. They have a good efficiency and do not generate greenhouse gases. This technology involves a lot of scientific fields, which leads to the appearance of strongly inter-dependent parameters. This makes the system particularly hard to control and increases fault's occurrence frequency. These two issues call for the necessity to maintain the system performance at the expected level, even in faulty operating conditions. It is called ;fault tolerant control; (FTC). The present paper aims to give the state of the art of FTC applied to the proton exchange membrane fuel cell (PEMFC). The FTC approach is composed of two parts. First, a diagnosis part allows the identification and the isolation of a fault; it requires a good a priori knowledge of all the possible faults. Then, a control part allows an optimal control strategy to find the best operating point to recover/mitigate the fault; it requires the knowledge of the degradation phenomena and their mitigation strategies.

  18. Mathematical modeling and simulation of thermal management in polymer electrolyte membrane fuel cell stacks

    Science.gov (United States)

    Amirfazli, Amir; Asghari, Saeed; Koosha, Morteza

    2014-12-01

    The narrow range of operating temperature and small temperature differences between the stack and the ambient have made the fuel cell thermal management as one of the key factors that influence the performance and durability of polymer electrolyte membrane fuel cell (PEMFC) stacks. In the present study, an analytical model is developed to investigate coolant flow and temperature distributions within a PEMFC stack. The model consists of a coolant flow distribution submodel and a thermal submodel for determination of coolant mass flow distribution between different cooling flow fields of the stack and the temperature distribution within the stack, respectively. The coolant mass flow rate and the temperature distributions in stacks with U and Z configurations are compared with each other using the developed model. The test results of two 65-cells stacks are presented to verify the simulation. The results indicate that the Z configuration results in more uniform temperature distribution than the U configuration in low values of the manifold cross sectional area. However, the Z configuration cannot be applied in the stacks with very small manifold sizes. A parametric analysis is also conducted to assess the effects of some parameters on the temperature distribution in a stack.