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Sample records for exchange membrane fuel

  1. 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

  2. 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

  3. 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...complexity and carbonate formation. Anion exchange membrane (AEMs) fuel cells have a number of advantages over both PEM fuel cells and traditional AFCs...release; distribution is unlimited. (Invited) Thin Robust Anion Exchange Membranes for Fuel Cell Applications The views, opinions and/or findings

  4. Fuel cell ion-exchange membrane investigation

    Science.gov (United States)

    Toy, M. S.

    1972-01-01

    The present deficiencies in the fluorocarbon sulfonic acid membrane used as the solid polymer electrolyte in the H2/O2 fuel cell are studied. Considered are: Adhesives selection, elastomeric formulations, scavenger exploration, and membrane characterization. The significant data are interpreted and recommendations are given for both short and long range further investigations in two of the four major areas: membrane adhesives and membrane stabilization.

  5. 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

  6. Electronic circuit model for proton exchange membrane fuel cells

    Science.gov (United States)

    Yu, Dachuan; Yuvarajan, S.

    The proton exchange membrane (PEM) fuel cell is being investigated as an alternate power source for various applications like transportation and emergency power supplies. The paper presents a novel circuit model for a PEM fuel cell that can be used to design and analyze fuel cell power systems. The PSPICE-based model uses bipolar junction transistors (BJTs) and LC elements available in the PSPICE library with some modification. The model includes the phenomena like activation polarization, ohmic polarization, and mass transport effect present in a PEM fuel cell. The static and dynamic characteristics obtained through simulation are compared with experimental results obtained on a commercial fuel cell module.

  7. Hydroxyl pyridine containing polybenzimidazole membranes for proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

    Yang, Jingshuai; Xu, Yixin; Zhou, Lu

    2013-01-01

    at 180°C without humidifying. In addition, an improved tensile modulus at elevated temperatures was observed for acid doped OHPyPBI membranes. Fuel cell tests demonstrated the technical feasibility of acid doped OHPyPBI membranes for high temperature proton exchange membrane fuel cells. © 2013 Elsevier B.V....

  8. A direct ascorbate fuel cell with an anion exchange membrane

    Science.gov (United States)

    Muneeb, Omar; Do, Emily; Tran, Timothy; Boyd, Desiree; Huynh, Michelle; Ghosn, Gregory; Haan, John L.

    2017-05-01

    Ascorbic Acid (Vitamin C) is investigated as a renewable alternative fuel for alkaline direct liquid fuel cells (DLFCs). The environmentally- and biologically-friendly compound, L-ascorbic acid (AA) has been modeled and studied experimentally under acidic fuel cell conditions. In this work, we demonstrate that ascorbic acid is a more efficient fuel in alkaline media than in acidic media. An operating direct ascorbate fuel cell is constructed with the combination of L-ascorbic acid and KOH as the anode fuel, air or oxygen as the oxidant, a polymer anion exchange membrane, metal or carbon black anode materials and metal cathode catalyst. Operation of the fuel cell at 60 °C using 1 M AA and 1 M KOH as the anode fuel and electrolyte, respectively, and oxygen gas at the cathode, produces a maximum power density of 73 mW cm-2, maximum current density of 497 mA cm-2 and an open circuit voltage of 0.90 V. This performance is significantly greater than that of an ascorbic acid fuel cell with a cation exchange membrane, and it is competitive with alkaline DLFCs fueled by alcohols.

  9. 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.

  10. 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...... of the electricity will be consumed by pumps and compressors in the system. Generally the whole system can be separated in three parts, cathode circuit, anode circuit and cooling loops. In this paper the effect of operating conditions and anode recirculation on power production as well as system efficiency have been...

  11. Highly Water Resistant Anion Exchange Membrane for Fuel Cells.

    Science.gov (United States)

    Yang, Zhengjin; Hou, Jianqiu; Wang, Xinyu; Wu, Liang; Xu, Tongwen

    2015-07-01

    For anion exchange membranes (AEMs), achieving efficient hydroxide conductivity without excessive hydrophilicity presents a challenge. Hence, new strategies for constructing mechanically strengthened and hydroxide conductive (especially at controlled humidity) membranes are critical for developing better AEMs. Macromolecular modification involving ylide chemistry (Wittig reaction) for the fabrication of novel AEMs with an interpenetrating polymer network structure is reported. The macromolecular modification is cost effective, facile, and based on a one-pot synthesis. AEM water uptake is reduced to 3.6 wt% and a high hydroxide conductivity (69.7 mS cm(-1) , 90 °C) is achieved simultaneously. More importantly, the membrane exhibits similar tensile strength (>35 MPa) and comparable flexibility in both dry and wet states. These AEMs could find further applications within anion exchange membrane fuel cells with low humidity or photoelectric assemblies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. 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......- and system models match experimental data from the literature. However, limited data were available for verification so further work is necessary to confirm detailed aspects of the models. It is nonetheless expected that the developed models will be useful for system modeling and optimization of PEM fuel...

  13. Highly durable direct hydrazine hydrate anion exchange membrane fuel cell

    Science.gov (United States)

    Sakamoto, Tomokazu; Serov, Alexey; Masuda, Teruyuki; Kamakura, Masaki; Yoshimoto, Koji; Omata, Takuya; Kishi, Hirofumi; Yamaguchi, Susumu; Hori, Akihiro; Horiuchi, Yousuke; Terada, Tomoaki; Artyushkova, Kateryna; Atanassov, Plamen; Tanaka, Hirohisa

    2018-01-01

    The factors influenced on degradation of direct hydrazine hydrate fuel cells (DHFCs) under operation conditions are analyzed by in situ soft X-ray radiography. A durability of DHFCs is significantly improved by multi-step reaction DHFCs (MSR-DHFCs) approach designed to decrease the crossover of liquid fuel. An open circuit voltage (OCV) as well as cell voltage at 5 mA cm-2 of MSR-DHFC construct with commercial anion exchange membrane (AEM) maintained for over of 3500 h at 60 °C. Furthermore, the commercial proton exchange membrane (PEM) is integrated into AEM of MSR-DHFCs resulting in stable power output of MSR-DHFCs for over than 2800 h at 80 °C.

  14. A Novel Unitized Regenerative Proton Exchange Membrane Fuel Cell

    Science.gov (United States)

    Murphy, O. J.; Cisar, A. J.; Gonzalez-Martin, A.; Salinas, C. E.; Simpson, S. F.

    1996-01-01

    A difficulty encountered in designing a unitized regenerative proton exchange membrane (PEM) fuel cell lies in the incompatibility of electrode structures and electrocatalyst materials optimized for either of the two functions (fuel cell or electrolyzer) with the needs of the other function. This difficulty is compounded in previous regenerative fuel cell designs by the fact that water, which is needed for proton conduction in the PEM during both modes of operation, is the reactant supplied to the anode in the electrolyzer mode of operation and the product formed at the cathode in the fuel cell mode. Drawbacks associated with existing regenerative fuel cells have been addressed. In a first innovation, electrodes function either as oxidation electrodes (hydrogen ionization or oxygen evolution) or as reduction electrodes (oxygen reduction or hydrogen evolution) in the fuel cell and electrolyzer modes, respectively. Control of liquid water within the regenerative fuel cell has been brought about by a second innovation. A novel PEM has been developed with internal channels that permit the direct access of water along the length of the membrane. Lateral diffusion of water along the polymer chains of the PEM provides the water needed at electrode/PEM interfaces. Fabrication of the novel single cell unitized regenerative fuel cell and results obtained on testing it are presented.

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

    DEFF Research Database (Denmark)

    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......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...... mode of PEMFCs. Under idle, load-cycling or start-up/shutdown modes of operation, which are prerequisite for automobile applications, the cathode will experience significantly higher potentials and therefore suffer from serious carbon corrosion, especially at the presence of platinum. The carbon...

  16. Review of cell performance in anion exchange membrane fuel cells

    Science.gov (United States)

    Dekel, Dario R.

    2018-01-01

    Anion exchange membrane fuel cells (AEMFCs) have recently received increasing attention since in principle they allow for the use of non-precious metal catalysts, which dramatically reduces the cost per kilowatt of power in fuel cell devices. Until not long ago, the main barrier in the development of AEMFCs was the availability of highly conductive anion exchange membranes (AEMs); however, improvements on this front in the past decade show that newly developed AEMs have already reached high levels of conductivity, leading to satisfactory cell performance. In recent years, a growing number of research studies have reported AEMFC performance results. In the last three years, new records in performance were achieved. Most of the literature reporting cell performance is based on hydrogen-AEMFCs, although an increasing number of studies have also reported the use of fuels others than hydrogen - such as alcohols, non-alcohol C-based fuels, as well as N-based fuels. This article reviews the cell performance and performance stability achieved in AEMFCs through the years since the first reports in the early 2000s.

  17. Nonhumidified High-Temperature Membranes Developed for Proton Exchange Membrane Fuel Cells

    Science.gov (United States)

    Kinder, James D.

    2005-01-01

    Fuel cells are being considered for a wide variety of aerospace applications. One of the most versatile types of fuel cells is the proton-exchange-membrane (PEM) fuel cell. PEM fuel cells can be easily scaled to meet the power and space requirements of a specific application. For example, small 100-W PEM fuel cells are being considered for personal power for extravehicular activity suit applications, whereas larger PEM fuel cells are being designed for primary power in airplanes and in uninhabited air vehicles. Typically, PEM fuel cells operate at temperatures up to 80 C. To increase the efficiency and power density of the fuel cell system, researchers are pursuing methods to extend the operating temperature of the PEM fuel cell to 180 C. The most widely used membranes in PEM fuel cells are Nafion 112 and Nafion 117--sulfonated perfluorinated polyethers that were developed by DuPont. In addition to their relatively high cost, the properties of these membranes limit their use in a PEM fuel cell to around 80 C. The proton conductivity of Nafion membranes significantly decreases above 80 C because the membrane dehydrates. The useful operating range of Nafion-based PEM fuel cells can be extended to over 100 C if ancillary equipment, such as compressors and humidifiers, is added to maintain moisture levels within the membrane. However, the addition of these components reduces the power density and increases the complexity of the fuel cell system.

  18. 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.

  19. Preparation of Highly Sulfonated Ultra-Thin Proton-Exchange Polymer Membranes for Proton Exchange Membrane Fuel Cells

    Science.gov (United States)

    Jiang, Zhongqing; Meng, Yuedong; Jiang, Zhong-Jie; Shi, Yicai

    Sulfonated ultra-thin proton-exchange polymer membrane carrying pyridine groups was made from a plasma polymerization of styrene, 2-vinylpyridine, and trifluoromethanesulfonic acid by after-glow capacitively coupled discharge technique. Pyridine groups tethered to the polymer backbone acts as a medium through the basic nitrogen for transfer of protons between the sulfonic acid groups of proton exchange membrane. It shows that the method using present technology could effectively depress the degradation of monomers during the plasma polymerization. Spectroscopic analyses reveal that the obtained membranes are highly functionalized with proton exchange groups and have higher proton conductivity. Thus, the membranes are expected to be used in direct methanol fuel cells.

  20. 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.

  1. A general model of proton exchange membrane fuel cell

    Science.gov (United States)

    Le, Anh Dinh; Zhou, Biao

    In this study, a general model of proton exchange membrane fuel cell (PEMFC) was constructed, implemented and employed to simulate the fluid flow, heat transfer, species transport, electrochemical reaction, and current density distribution, especially focusing on liquid water effects on PEMFC performance. The model is a three-dimensional and unsteady one with detailed thermo-electrochemistry, multi-species, and two-phase interaction with explicit gas-liquid interface tracking by using the volume-of-fluid (VOF) method. The general model was implemented into the commercial computational fluid dynamics (CFD) software package FLUENT ® v6.2, with its user-defined functions (UDFs). A complete PEMFC was considered, including membrane, gas diffusion layers (GDLs), catalyst layers, gas flow channels, and current collectors. The effects of liquid water on PEMFC with serpentine channels were investigated. The results showed that this general model of PEMFC can be a very useful tool for the optimization of practical engineering designs of PEMFC.

  2. Proton Exchange Membrane Fuel Cell Reversal: A Review

    Directory of Open Access Journals (Sweden)

    Congwei Qin

    2016-12-01

    Full Text Available The H2/air-fed proton exchange membrane fuel cell (PEMFC has two major problems: cost and durability, which obstruct its pathway to commercialization. Cell reversal, which would create irreversible damage to the fuel cell and shorten its lifespan, is caused by reactant starvation, load change, low catalyst performance, and so on. This paper will summarize the causes, consequences, and mitigation strategies of cell reversal of PEMFC in detail. A description of potential change in the anode and cathode and the differences between local starvation and overall starvation are reviewed, which gives a framework for comprehending the origins of cell reversal. According to the root factor of cell starvation, i.e., fuel cells do not satisfy the requirements of electrons and protons of normal anode and cathode chemical reactions, we will introduce specific methods to mitigate or prevent fuel cell damage caused by cell reversal in the view of system management strategies and component material modifications. Based on a comprehensive understanding of cell reversal, it is beneficial to operate a fuel cell stack and extend its lifetime.

  3. Modelling and validation of Proton exchange membrane fuel cell (PEMFC)

    Science.gov (United States)

    Mohiuddin, A. K. M.; Basran, N.; Khan, A. A.

    2018-01-01

    This paper is the outcome of a small scale fuel cell project. Fuel cell is an electrochemical device that converts energy from chemical reaction to electrical work. Proton Exchange Membrane Fuel Cell (PEMFC) is one of the different types of fuel cell, which is more efficient, having low operational temperature and fast start up capability results in high energy density. In this study, a mathematical model of 1.2 W PEMFC is developed and simulated using MATLAB software. This model describes the PEMFC behaviour under steady-state condition. This mathematical modeling of PEMFC determines the polarization curve, power generated, and the efficiency of the fuel cell. Simulation results were validated by comparing with experimental results obtained from the test of a single PEMFC with a 3 V motor. The performance of experimental PEMFC is little lower compared to simulated PEMFC, however both results were found in good agreement. Experiments on hydrogen flow rate also been conducted to obtain the amount of hydrogen consumed to produce electrical work on PEMFC.

  4. Anion exchange membrane fuel cells: Current status and remaining challenges

    Science.gov (United States)

    Gottesfeld, Shimshon; Dekel, Dario R.; Page, Miles; Bae, Chulsung; Yan, Yushan; Zelenay, Piotr; Kim, Yu Seung

    2018-01-01

    The anion exchange membrane fuel cell (AEMFC) is an attractive alternative to acidic proton exchange membrane fuel cells, which to date have required platinum-based catalysts, as well as acid-tolerant stack hardware. The AEMFC could use non-platinum-group metal catalysts and less expensive metal hardware thanks to the high pH of the electrolyte. Over the last decade, substantial progress has been made in improving the performance and durability of the AEMFC through the development of new materials and the optimization of system design and operation conditions. In this perspective article, we describe the current status of AEMFCs as having reached beginning of life performance very close to that of PEMFCs when using ultra-low loadings of Pt, while advancing towards operation on non-platinum-group metal catalysts alone. In the latter sections, we identify the remaining technical challenges, which require further research and development, focusing on the materials and operational factors that critically impact AEMFC performance and/or durability. These perspectives may provide useful insights for the development of next-generation of AEMFCs.

  5. The application of Dow Chemical's perfluorinated membranes in proton-exchange membrane fuel cells

    Science.gov (United States)

    Eisman, G. A.

    1989-01-01

    Dow Chemical's research activities in fuel cells revolve around the development of perfluorosulfonic acid membranes useful as the proton transport medium and separator. Some of the performance characteristics which are typical for such membranes are outlined. The results of tests utilizing a new experimental membrane useful in proton-exchange membrane fuel cells are presented. The high voltage at low current densities can lead to higher system efficiencies while, at the same time, not sacrificing other critical properties pertinent to membrane fuel cell operation. A series of tests to determine response times indicated that on-off cycles are on the order of 80 milliseconds to reach 90 percent of full power. The IR free voltage at 100 amps/sq ft was determined and the results indicating a membrane/electrode package resistance to be .15 ohm-sq cm at 100 amps/sq ft.

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

    Science.gov (United States)

    Ulusoy, Sehribani

    results showed that the fuel performance can be improved by using flow field designs alleviating the reactant depletion along the channels and supplying more uniform reactant distribution. Stepped flow field was found to show better performance when compared to straight and tapered ones. ANSYS FLUENT model is evaluated in terms of predicting the two phase flow in the fuel cell components. It is proposed that it is not capable of predicting the entire fuel cell polarization due to the lack of agglomerate catalyst layer modeling and well-established two-phase flow modeling. Along with the comprehensive modeling efforts, also an analytical model has been computed by using MathCAD and it is found that this simpler model is able to predict the performance in a general trend according to the experimental data obtained for a new novel membrane. Therefore, it can be used for robust prediction of the cell performance at different operating conditions such as temperature and pressure, and the electrochemical properties such as the catalyst loading, the exchange current density and the diffusion coefficients of the reactants. In addition to the modeling efforts, this thesis also presents a very comprehensive literature review on the models developed in the literature so far, the modeling efforts in fuel cell sandwich including membrane, catalyst layer and gas diffusion layer and fuel cell model properties. Moreover, a summary of possible directions of research in fuel cell analysis and computational modeling has been presented.

  7. 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.

  8. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Shamsuddin Ilias

    2001-07-06

    Proton Exchange Membrane Fuel Cell (PEMFC) is one of the most promising power sources for space and electric vehicle applications. Platinum (Pt) catalyst is used for both fuel and air electrodes in PEMFCs. The carbon monoxide (CO) contamination of H{sub 2} greatly affects electrocatalysts used at the anode of PEMFCs and decrease the cell performance. This irreversible poisoning of the anode can happen even in CO concentrations as low as few ppm, and therefore, require expensive scrubbing of the H{sub 2}-fuel to reduce the contaminant concentration to acceptable level. In order to commercialize this environmentally sound source of energy/power system, development of suitable CO-tolerant catalyst is needed. In this work, we have synthesized several novel electrocatalysts (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. The concentration of CO in the H{sub 2} fuel varied from 10 ppm to 100 ppm. The performance of the electrodes was evaluated by determining the cell potential against current density. The effect of temperature, catalyst compositions, and electrode film preparation methods on the performance of PEM fuel cell has also been studied. It was found that at 70 C and 3.5 atm pressure at the cathode, Pt-alloy catalysts (10 wt % Pt/Ru/C, 20 wt % Pt/Mo/C) were more CO-tolerant than 20 wt % Pt catalyst alone. It was also observed that spraying method is better for the preparation of electrode film than the brushing technique. Some of these results are summarized in this report.

  10. Numerical modeling transport phenomena in proton exchange membrane fuel cells

    Science.gov (United States)

    Suh, DongMyung

    To study the coupled phenomena occurring in proton exchange membrane fuel cells, a two-phase, one-dimensional, non-isothermal model is developed in the chapter 1. The model includes water phase change, proton transport in the membrane and electro-osmotic effect. The thinnest, but most complex layer in the membrane electrode assembly, catalyst layer, is considered an interfacial boundary between the gas diffusion layer and the membrane. Mass and heat transfer and electro-chemical reaction through the catalyst layer are formulated into equations, which are applied to boundary conditions for the gas diffusion layer and the membrane. Detail accounts of the boundary equations and the numerical solving procedure used in this work are given. The polarization curve is calculated at different oxygen pressures and compared with the experimental results. When the operating condition is changed along the polarization curve, the change of physicochemical variables in the membrane electrode assembly is studied. In particular, the over-potential diagram presents the usage of the electrochemical energy at each layer of the membrane electrode assembly. Humidity in supplying gases is one of the most important factors to consider for improving the performance of PEMFE. Both high and low humidity conditions can result in a deteriorating cell performance. The effect of humidity on the cell performance is studied in the chapter 2. First, a numerical model based on computational fluid dynamics is developed. Second, the cell performances are simulated, when the relative humidity is changed from 0% to 100% in the anode and the cathode channel. The simulation results show how humidity in the reactant gases affects the water content distribution in the membrane, the over-potential at the catalyst layers and eventually the cell performance. In particular, the rapid enhancement in the cell performance caused by self-hydrating membrane is captured by the simulation. Fully humidifying either H2

  11. 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.

  12. Tandem cathode for proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

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

    2013-01-01

    tandem cathode design where the full oxygen reduction, involving four electron-transfer steps, is divided into formation (equilibrium potential 0.70 V) followed by reduction (equilibrium potential 1.76 V) of hydrogen peroxide. The two part reactions contain only two electron-transfer steps and one......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. Transient response of a proton exchange membrane fuel cell

    Science.gov (United States)

    Weydahl, Helge; Møller-Holst, Steffen; Hagen, Georg; Børresen, Børre

    The transient response of a proton exchange membrane fuel cell (PEMFC) supplied with pure hydrogen and oxygen was investigated by load step measurements assisted by electrochemical impedance spectroscopy and chronoamperometry. Using an in-house designed resistance board, the uncontrolled response in both cell voltage and current upon step changes in a resistive load was observed. The PEMFC was found to respond quickly and reproducibly to load changes. The transient PEMFC response was limited by a cathodic charge transfer process with a potential-dependent response time. For load steps to high-current densitities, a second transient process with a constant response time was observed. This transient was offset from the charge transfer transient by a temporarily stable plateau. Results from chronoamperometry indicated that the second transient could be related to a diffusion process. Transient paths were plotted in the V- i diagram, matching a predicted pattern with overshooting cell voltage and current during a load step.

  14. 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.

  15. Reactivation System for Proton-Exchange Membrane Fuel-Cells

    Directory of Open Access Journals (Sweden)

    Roberto Giral

    2012-07-01

    Full Text Available In recent years, Proton-Exchange Membrane Fuel Cells (PEMFCs have been the focus of very intensive researches. Manufacturers of these alternative power sources propose a rejuvenation sequence after the FC has been operating at high power for a certain period of time. These rejuvenation methods could be not appropriate for the reactivation of the FC when it has been out of operation for a long period of time or after it has been repaired. Since the developed reactivation system monitors temperature, current, and the cell voltages of the stack, it could be also useful for the diagnostic and repairing processes. The limited number of published contributions suggests that systems developing reactivation techniques are an open research field. In this paper, an automated system for reactivating PEMFCs and results of experimental testing are presented.

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

    DEFF Research Database (Denmark)

    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......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...

  17. Importance of balancing membrane and electrode water in anion exchange membrane fuel cells

    Science.gov (United States)

    Omasta, T. J.; Wang, L.; Peng, X.; Lewis, C. A.; Varcoe, J. R.; Mustain, W. E.

    2018-01-01

    Anion exchange membrane fuel cells (AEMFCs) offer several potential advantages over proton exchange membrane fuel cells (PEMFCs), most notably to overcome the cost barrier that has slowed the growth and large scale implementation of fuel cells for transportation. However, limitations in performance have held back AEMFCs, specifically in the areas of stability, carbonation, and maximum achievable current and power densities. In order for AEMFCs to contend with PEMFCs for market viability, it is necessary to realize a competitive cell performance. This work demonstrates a new benchmark for a H2/O2 AEMFC with a peak power density of 1.4 W cm-2 at 60 °C. This was accomplished by taking a more precise look at balancing necessary membrane hydration while preventing electrode flooding, which somewhat surprisingly can occur both at the anode and the cathode. Specifically, radiation-grafted ETFE-based anion exchange membranes and anion exchange ionomer powder, functionalized with benchmark benzyltrimethylammonium groups, were utilized to examine the effects of the following parameters on AEMFC performance: feed gas flow rate, the use of hydrophobic vs. hydrophilic gas diffusion layers, and gas feed dew points.

  18. High power density proton exchange membrane fuel cells

    Science.gov (United States)

    Murphy, Oliver J.; Hitchens, G. Duncan; Manko, David J.

    1993-01-01

    Proton exchange membrane (PEM) fuel cells use a perfluorosulfonic acid solid polymer film as an electrolyte which simplifies water and electrolyte management. Their thin electrolyte layers give efficient systems of low weight, and their materials of construction show extremely long laboratory lifetimes. Their high reliability and their suitability for use in a microgravity environment makes them particularly attractive as a substitute for batteries in satellites utilizing high-power, high energy-density electrochemical energy storage systems. In this investigation, the Dow experimental PEM (XUS-13204.10) and unsupported high platinum loading electrodes yielded very high power densities, of the order of 2.5 W cm(exp -2). A platinum black loading of 5 mg per cm(exp 2) was found to be optimum. On extending the three-dimensional reaction zone of fuel cell electrodes by impregnating solid polymer electrolyte into the electrode structures, Nafion was found to give better performance than the Dow experimental PEM. The depth of penetration of the solid polymer electrolyte into electrode structures was 50-70 percent of the thickness of the platinum-catalyzed active layer. However, the degree of platinum utilization was only 16.6 percent and the roughness factor of a typical electrode was 274.

  19. 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

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

  20. Ion exchange membrane cathodes for scalable microbial fuel cells.

    Science.gov (United States)

    Zuo, Yi; Cheng, Shaoan; Logan, Bruce E

    2008-09-15

    One of the main challenges for using microbial fuel cells (MFCs) is developing materials and architectures that are economical and generate high power densities. The performance of two cathodes constructed from two low-cost anion (AEM) and cation (CEM) exchange membranes was compared to that achieved using an ultrafiltration (UF) cathode, when the membranes were made electrically conductive using graphite paint and a nonprecious metal catalyst (CoTMPP). The best performance in single-chamber MFCs using graphite fiber brush anodes was achieved using an AEM cathode with the conductive coating facing the solution, at a catalyst loading of 0.5 mg/cm2 CoTMPP. The maximum power densitywas 449 mW/ m2 (normalized to the projected cathode surface area) or 13.1 W/m3 (total reactor volume), with a Coulombic efficiency up to 70% in a 50 mM phosphate buffer solution (PBS) using acetate. Decreasing the CoTMPP loading by 40-80% reduced power by 28-56%, with only 16% of the power (72 mW/m2) generated using an AEM cathode lacking a catalyst. Using a current collector (a stainless steel mesh) pressed against the inside surface of the AEM cathode and 200 mM PBS, the maximum power produced was further increased to 728 mW/m2 (21.2 W/m3). The use of AEM cathodes and brush anodes provides comparable performance to similar systems that use materials costing nearly an order of magnitude more (carbon paper electrodes) and thus represent more useful materials for reducing the costs of MFCs for wastewater treatment applications.

  1. 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...... group is achieved in 85wt% H3PO4 at room temperature. The membranes exhibit a proton conductivity of 0.015–0.022Scm−1 at 130–150°C under 15mol% water vapor in air, and a tensile strength of 5–6MPa at 130°C under ambient humidity. Fuel cell tests show an open circuit voltage as high as 0.96V and a peak...

  2. Polymer-zeolite nanocomposite membranes for proton exchange membrane fuel cells

    Science.gov (United States)

    Holmberg, Brett Anderson

    2005-07-01

    Proton exchange membrane fuel cells (PEMFCs) have recently received a great deal of attention for their potential as compact, high efficiency power sources for portable, distributed generation, and transportation applications. Unfortunately, current proton exchange membrane (PEM) technology hinders fuel cell performance by limiting fuel cell operation temperature and methanol feed concentration in direct methanol fuel cells (DMFCs). Nafion-zeolite nanocomposite membranes that take advantage of the hydrophilicity, selectivity, and proton conductivity of zeolite nanocrystals have been developed to address these problems. All known zeolite topologies were evaluated as potential additives to Nafion proton exchange membranes. Zeolites Y and beta were determined to have great potential as additives due to their low framework density, three dimensional pore structure, and high hydrophilicity. Zeolite Y nanocrystal syntheses were optimized to enhance yield and produce smaller crystal size. Significant improvement of the acid stability of the zeolite Y nanocrystals was not achieved with both ammonium hexafluorosilicate treatments and direct high silica nanocrystal synthesis. However, control of zeolite Y nanocrystal framework Si/Al ratio was demonstrated in the range of SiO2/Al2O3 = 4.38 to 5.84 by manipulating the tetramethylammonium structure directing agent hydroxide content. Zeolite beta nanocrystals were investigated due to their inherent high silica content and high acid stability. Zeolite beta nanocrystals were hydrothermally synthesized with and without phenethyl (called PE-BEA and BEA respectively) organic functional groups. Sulfonic acid functionalized zeolite beta (SAPE-BEA) was generated by treating the PE-BEA nanocrystals with a concentrated sulfuric acid post synthesis treatment. SAPE-BEA samples demonstrated proton conductivities up to 0.01 S/cm at room temperature under water-saturated conditions using a newly developed characterization technique. With

  3. Sulfated Titania-Silica Reinforced Nafion Nanocomposite Membranes for Proton Exchange Membrane Fuel Cells.

    Science.gov (United States)

    Abu Sayeed, M D; Kim, Hee Jin; Gopalan, A I; Kim, Young Ho; Lee, Kwang-Pill; Choi, Sang-June

    2015-09-01

    Sulfated titania-silica (SO4(2-)-/TiO2-SiO2) composites were prepared by a sol-gel method with sulfate reaction and characterized by X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). The nanometric diameter and geometry of the sulfated titania-silica (STS) was investigated by transmission electron microscopy (TEM). A small amount of the STS composite in the range of 0.5-3 wt% was then added as reinforcing into the Nafion membrane by water-assisted solution casting method to prepare STS reinforced Nafion nanocomposite membranes (STS-Nafion nanocomposite membranes). The additional functional groups, sulfate groups, of the nanocomposite membrane having more surface oxygenated groups enhanced the fuel cell membrane properties. The STS-Nafion nanocomposite membranes exhibited improved water uptake compared to that of neat Nafion membranes, whereas methanol uptake values were decreased dramatically improved thermal property of the prepared nanocomposite membranes were measured by thermogravimetric analysis (TGA). Furthermore, increased ion exchange capacity values were obtained by thermoacidic pretreatment of the nanocomposite membranes.

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

    DEFF Research Database (Denmark)

    Hosseinzadeh, Elham; Rokni, Masoud

    2011-01-01

    thermodynamically. The system includes a compressor, an air humidifier, set of heat exchangers and a stack which together build up the anode circuit, the cathode circuit and the cooling loop. Since fuel humidification is carried out via water cross over from cathode to anode, there is no humidifier in the anode...

  5. 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.

  6. A self-sustained, complete and miniaturized methanol fuel processor for proton exchange membrane fuel cell

    Science.gov (United States)

    Yang, Mei; Jiao, Fengjun; Li, Shulian; Li, Hengqiang; Chen, Guangwen

    2015-08-01

    A self-sustained, complete and miniaturized methanol fuel processor has been developed based on modular integration and microreactor technology. The fuel processor is comprised of one methanol oxidative reformer, one methanol combustor and one two-stage CO preferential oxidation unit. Microchannel heat exchanger is employed to recover heat from hot stream, miniaturize system size and thus achieve high energy utilization efficiency. By optimized thermal management and proper operation parameter control, the fuel processor can start up in 10 min at room temperature without external heating. A self-sustained state is achieved with H2 production rate of 0.99 Nm3 h-1 and extremely low CO content below 25 ppm. This amount of H2 is sufficient to supply a 1 kWe proton exchange membrane fuel cell. The corresponding thermal efficiency of whole processor is higher than 86%. The size and weight of the assembled reactors integrated with microchannel heat exchangers are 1.4 L and 5.3 kg, respectively, demonstrating a very compact construction of the fuel processor.

  7. 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

  8. 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.

  9. New High-Temperature Membranes Developed for Proton Exchange Membrane Fuel Cells

    Science.gov (United States)

    Kinder, James D.

    2004-01-01

    Fuel cells are receiving a considerable amount of attention for potential use in a variety of areas, including the automotive industry, commercial power generation, and personal electronics. Research at the NASA Glenn Research Center has focused on the development of fuel cells for use in aerospace power systems for aircraft, unmanned air vehicles, and space transportation systems. These applications require fuel cells with higher power densities and better durability than what is required for nonaerospace uses. In addition, membrane cost is a concern for any fuel cell application. The most widely used membrane materials for proton exchange membrane (PEM) fuel cells are based on sulfonated perfluorinated polyethers, typically Nafion 117, Flemion, or Aciplex. However, these polymers are costly and do not function well at temperatures above 80 C. At higher temperatures, conventional membrane materials dry out and lose their ability to conduct protons, essential for the operation of the fuel cell. Increasing the operating temperature of PEM fuel cells from 80 to 120 C would significantly increase their power densities and enhance their durability by reducing the susceptibility of the electrode catalysts to carbon monoxide poisoning. Glenn's Polymers Branch has focused on developing new, low-cost membranes that can operate at these higher temperatures. A new series of organically modified siloxane (ORMOSIL) polymers were synthesized for use as membrane materials in a high-temperature PEM fuel cell. These polymers have an organic portion that can allow protons to transport through the polymer film and a cross-linked silica network that gives the polymers dimensional stability. These flexible xerogel polymer films are thermally stable, with decomposition onset as high as 380 C. Two types of proton-conducting ORMOSIL films have been produced: (1) NASA-A, which can coordinate many highly acid inorganic salts that facilitate proton conduction and (2) NASA-B, which has been

  10. 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...

  11. 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.

  12. 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.

  13. 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].

  14. Theoretical Energy and Exergy Analyses of Proton Exchange Membrane Fuel Cell by Computer Simulation

    OpenAIRE

    I. D. Gimba; Abdulkareem, A. S.; Jimoh, A.; A. S. Afolabi

    2016-01-01

    A mathematical model of a proton exchange membrane fuel cell (PEMFC) was developed to investigate the effects of operating parameters such as temperature, anode and cathode pressures, reactants flow rates, membrane thickness, and humidity on the performance of the modelled fuel cell. The developed model consisted of electrochemical, heat energy and exergy components which were later simulated using a computer programme. The simulated model for the voltage output of the cell showed good confor...

  15. 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 of alkaline anionic-exchange membranes for direct alcohol fuel cells P. Nonjola*, M. Mathe, S. Hietkamp Materials Science and Manufacturing, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria 0001, South Africa *snonjola... exchange membranes from poly(arylene ether), by the conventional aromatic nucleophilic displacement route via chloromethylation and quaternary amination. The primary objective was to acquire basic information on structure-property relationships to permit...

  16. Performance of organic-inorganic hybrid anion-exchange membranes for alkaline direct methanol fuel cells

    Science.gov (United States)

    Xiong, Ying; Liu, Qing Lin; Zhu, Ai Mei; Huang, Si Meng; Zeng, Qing Hua

    A series of organic-inorganic membranes were prepared through sol-gel reaction of quaternized poly(vinyl alcohol) (QAPVA) with different contents of tetraethoxysilanes (TEOS) for alkaline direct methanol fuel cells. These hybrid membranes are characterized by FTIR, X-ray diffraction (XRD), scanning electron microscopy/energy-dispersive X-ray analysis (SEM/EDXA) and thermo gravimetric analysis (TGA). The ion exchange content (IEC), water content, methanol permeability and conductivity of the hybrid membranes were measured to evaluate their applicability in fuel cells. It was found that the addition of silica enhanced the thermal stability and reduced the methanol permeability of the hybrid membranes. The hybrid membrane M-5, for which the silica content was 5 wt%, showed the lowest methanol permeability and the highest ion conductivity among the three hybrid membranes. The ratio of conductivity to methanol permeability of the membrane M-5 indicated that it had a high potential for alkaline direct methanol fuel cell applications.

  17. Highly conductive anion exchange membrane for high power density fuel-cell performance.

    Science.gov (United States)

    Ren, Xiaoming; Price, Samuel C; Jackson, Aaron C; Pomerantz, Natalie; Beyer, Frederick L

    2014-08-27

    Anion exchange membrane fuel cells (AEMFCs) are regarded as a new generation of fuel cell technology that has the potential to overcome many obstacles of the mainstream proton exchange membrane fuel cells (PEMFCs) in cost, catalyst stability, efficiency, and system size. However, the low ionic conductivity and poor thermal stability of current anion exchange membranes (AEMs) have been the key factors limiting the performance of AEMFCs. In this study, an AEM made of styrenic diblock copolymer with a quaternary ammonium-functionalized hydrophilic block and a cross-linkable hydrophobic block and possessing bicontinuous phases of a hydrophobic network and hydrophilic conduction paths was found to have high ionic conductivity at 98 mS cm(-1) and controlled membrane swelling with water uptake at 117 wt % at 22 °C. Membrane characterizations and fuel cell tests of the new AEM were carried out together with a commercial AEM, Tokuyama A201, for comparison. The high ionic conductivity and water permeability of the new membrane reported in this study is attributed to the reduced torturosity of the ionic conduction paths, while the hydrophobic network maintains the membrane mechanical integrity, preventing excessive water uptake.

  18. Influence of water and membrane microstructure on the transport properties of proton exchange membrane fuel cells

    Science.gov (United States)

    Siu, Ana Rosa

    Proton transport in proton exchange membranes (PEMs) depends on interaction between water and acid groups covalently bound to the polymer. Although the presence of water is important in maintaining the PEM's functions, a thorough understanding of this topic is still lacking. The objective of this work is to provide a better understanding of how the nature water, confined to ionic domains of the polymer, influences the membrane's ability to transport protons, methanol and water. Understanding this topic will facilitate development of new materials with favorable transport properties for fuel cells use. Five classes of polymer membranes were used in this work: polyacrylonitrile-graft-poly(styrenesulfonic) acid (PAN-g-macPSSA); poly(vinylidene difluoride) irradiation-graft-poly(styrenesulfonic) acid (PVDF-g-PSSA); poly(ethylenetetrafluoroethylene) irradiation-graft-poly(styrenesulfonic) acid (ETFE-gPSSA); PVDF-g-PSSA with hydroxyethylmethacrylate (HEMA); and perfluorosulfonic acid membrane (Nafion). The nature of water within the polymers (freezable versus non-freezable states) was measured by systematically freezing samples, and observing the temperature at which water freezes and the amount of heat released in the process. Freezing water-swollen membranes resulted in a 4-fold decrease in the proton conductivity of the PEM. Activation energies of proton transport before and after freezing were ˜ 0.15 eV and 0.5 eV, consistent with proton transport through liquid water and bound water, respectively. Reducing the content of water in membrane samples decreased the amount of freezable and non-freezable water. Calorimetric measurements of membranes in various degrees of hydration showed that water molecules became non-freezable when lambda, (water molecules per sulfonic acid group) was less than ˜14. Proton conduction through membranes containing only non-freezable water was demonstrated to be feasible. Diffusion experiments showed that the permeability of methanol

  19. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. 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.

  1. 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

    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......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...

  2. Anion exchange composite membrane based on octa quaternary ammonium Polyhedral Oligomeric Silsesquioxane for alkaline fuel cells

    Science.gov (United States)

    Elumalai, Vijayakumar; Sangeetha, Dharmalingam

    2018-01-01

    A series of novel composite anion exchange membranes were prepared via simple solution casting method using synthesized quaternary ammonium functionalized Polyhedral Oligomeric Silsesquioxane (QA-POSS) with Quaternary polysulfone (QPSU). QA-POSS was synthesized from prepared Cl-POSS and well characterized by FT-IR, NMR, SEM and TEM analyses to confirm the chemical modifications and cubic morphologies. The QA-POSS nano particles have dual role in the membrane providing additional ion conducting groups and reinforcing the membrane in molecular level for the overall improvement of composite membrane. Additionally, the composite membranes were characterized by XRD, SEM, Ion exchange capacity (IEC), water uptake and conductivity to ensure the suitability of its use as an electrolyte in alkaline fuel cell. Finally, membrane electrode assembly (MEA) was fabricated using Pt anode (0.25 mg/cm2), Ag cathode (0.375 mg/cm2) and various synthesized composite membranes, and then it was tested in real time fuel cell setup. The membrane with 15% QA-POSS showed the maximum power density of 321 mW/cm2. The results showed that QA-POSS possess the ability to enhance the performance of the anion exchange membrane significantly.

  3. 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.

  4. FUEL CELL PROTON EXCHANGE MEMBRANE - PRESENT AND PERSPECTIVES

    Directory of Open Access Journals (Sweden)

    Victor CIUPINA

    2012-05-01

    Full Text Available The fuel cells could contribute to the reduction of the pollution emission and the fossil fuels due to the conversion efficiency which is higher than the other energy conversion systems. There are many possibilities to improve the efficiency and to reduce the weight of the fuel cells by the integration of new nanostructured materials.

  5. Characterization of proton exchange membrane fuel cell anode catalysts prepared by colloid method

    Energy Technology Data Exchange (ETDEWEB)

    Franco, E.G.; Dantas-Filho, P.L.; Burani, G.F. [Universidade de Sao Paulo (IEE/USP), Sao Paulo, SP (Brazil). Instituto de Eletrotecnica e Energia

    2009-07-01

    Full text: Anode catalysts for Proton Exchange Membrane Fuel Cell (PEMFC) were synthesized by the colloid method and their structure was investigated by transmission electron microscopy (TEM), energy dispersive analyses (EDS), X-ray Diffraction (XRD). The electrochemical behavior of the anode catalyst was analyzed by cyclic voltammetry (CV) and polarization curves (UxI). (author)

  6. Model-based fault detection for proton exchange membrane fuel cell ...

    African Journals Online (AJOL)

    In this paper, an intelligent model-based fault detection (FD) is developed for proton exchange membrane fuel cell (PEMFC) dynamic systems using an independent radial basis function (RBF) networks. The novelty is that this RBF networks is used to model the PEMFC dynamic systems and residuals are generated based ...

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

    DEFF Research Database (Denmark)

    Zhang, Wenjing

    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...

  8. 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.

  9. POLYSULFONE COMPOSED OF POLYANILINE NANOPARTICLES AS NANOCOMPOSITE PROTON EXCHANGE MEMBRANE IN MICROBIAL FUEL CELL

    OpenAIRE

    Mostafa Ghasemi; Mostafa Rahimnejad; Chakavak Esmaeili; Wan Ramli Wan Daud; Mohd Shahbudin Masdar; Edy Herianto Majlan; Sedky H.A. Hassan; Javed Alam; Manal Ismail; Mansour Saleh Alhoshan

    2012-01-01

    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....

  10. 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.

  11. 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.

  12. Hot topics in alkaline exchange membrane fuel cells

    Science.gov (United States)

    Serov, Alexey; Zenyuk, Iryna V.; Arges, Christopher G.; Chatenet, Marian

    2018-01-01

    The tremendous progress from the first discovery of fuel cell principles by Sir William Robert Grove in 1839 [1] and independent observation of electricity generated in electrochemical reaction of hydrogen and air by a Swiss scientist Christian F. Shoenbein [2] to the recent breakthroughs in the fuel cell field resulted in the appearance of this clean energy technology around us. Indeed, fuel cell technology undoubtedly has entered into our life with the first introduction of Toyota Mirai Fuel Cell Vehicle (FCV) by Toyota Motor Co. in December of 2014 [3,4]. This FCV is commercially available and can be purchased in several countries. However, its sticker price of 57,500 substantially limits the number of customers that can purchase it. There are numerous factors that contribute to the high cost of fuel cell stack, however the price of platinum and platinum alloys is the main contributor [5].

  13. Transport in Proton Exchange Membranes for Fuel Cell Applications-A Systematic Non-Equilibrium Approach.

    Science.gov (United States)

    Rangel-Cárdenas, Angie L; Koper, Ger J M

    2017-05-25

    We hypothesize that the properties of proton-exchange membranes for fuel cell applications cannot be described unambiguously unless interface effects are taken into account. In order to prove this, we first develop a thermodynamically consistent description of the transport properties in the membranes, both for a homogeneous membrane and for a homogeneous membrane with two surface layers in contact with the electrodes or holder material. For each subsystem, homogeneous membrane, and the two surface layers, we limit ourselves to four parameters as the system as a whole is considered to be isothermal. We subsequently analyze the experimental results on some standard membranes that have appeared in the literature and analyze these using the two different descriptions. This analysis yields relatively well-defined values for the homogeneous membrane parameters and estimates for those of the surface layers and hence supports our hypothesis. As demonstrated, the method used here allows for a critical evaluation of the literature values. Moreover, it allows optimization of stacked transport systems such as proton-exchange membrane fuel cell units where interfacial layers, such as that between the catalyst and membrane, are taken into account systematically.

  14. Transport in Proton Exchange Membranes for Fuel Cell Applications—A Systematic Non-Equilibrium Approach

    Directory of Open Access Journals (Sweden)

    Angie L. Rangel-Cárdenas

    2017-05-01

    Full Text Available We hypothesize that the properties of proton-exchange membranes for fuel cell applications cannot be described unambiguously unless interface effects are taken into account. In order to prove this, we first develop a thermodynamically consistent description of the transport properties in the membranes, both for a homogeneous membrane and for a homogeneous membrane with two surface layers in contact with the electrodes or holder material. For each subsystem, homogeneous membrane, and the two surface layers, we limit ourselves to four parameters as the system as a whole is considered to be isothermal. We subsequently analyze the experimental results on some standard membranes that have appeared in the literature and analyze these using the two different descriptions. This analysis yields relatively well-defined values for the homogeneous membrane parameters and estimates for those of the surface layers and hence supports our hypothesis. As demonstrated, the method used here allows for a critical evaluation of the literature values. Moreover, it allows optimization of stacked transport systems such as proton-exchange membrane fuel cell units where interfacial layers, such as that between the catalyst and membrane, are taken into account systematically.

  15. 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.

  16. 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.

  17. Proton Exchange Membrane (PEM) fuel Cell for Space Shuttle

    Science.gov (United States)

    Hoffman, William C., III; Vasquez, Arturo; Lazaroff, Scott M.; Downey, Michael G.

    1999-01-01

    Development of a PEM fuel cell powerplant (PFCP) for use in the Space Shuttle offers multiple benefits to NASA. A PFCP with a longer design life than is delivered currently from the alkaline fuel will reduce Space Shuttle Program maintenance costs. A PFCP compatible with zero-gravity can be adapted for future NASA transportation and exploration programs. Also, the commercial PEM fuel cell industry ensures a competitive environment for select powerplant components. Conceptual designs of the Space Shuttle PFCP have resulted in identification of key technical areas requiring resolution prior to development of a flight system. Those technical areas include characterization of PEM fuel cell stack durability under operational conditions and water management both within and external to the stack. Resolution of the above issues is necessary to adequately control development, production, and maintenance costs for a PFCP.

  18. 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.

  19. In-situ membrane hydration measurement of proton exchange membrane fuel cells

    Science.gov (United States)

    Lai, Yeh-Hung; Fly, Gerald W.; Clapham, Shawn

    2015-01-01

    Achieving proper membrane hydration control is one of the most critical aspects of PEM fuel cell development. This article describes the development and application of a novel 50 cm2 fuel cell device to study the in-situ membrane hydration by measuring the through-thickness membrane swelling via an array of linear variable differential transducers. Using this setup either as an air/air (dummy) cell or as a hydrogen/air (operating) cell, we performed a series of hydration and dehydration experiments by cycling the RH of the inlet gas streams at 80 °C. From the linear relationship between the under-the-land swelling and the over-the-channel water content, the mechanical constraint within the fuel cell assembly can suppress the membrane water uptake by 11%-18%. The results from the air/air humidity cycling test show that the membrane can equilibrate within 120 s for all RH conditions and that membrane can reach full hydration at a RH higher than 140% in spite of the use of a liquid water impermeable Carbel MP30Z microporous layer. This result confirms that the U.S. DOE's humidity cycling mechanical durability protocol induces sufficient humidity swings to maximize hygrothermal mechanical stresses. This study shows that the novel experimental technique can provide a robust and accurate means to study the in-situ hydration of thin membranes subject to a wide range of fuel cell conditions.

  20. 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 H 2 -O 2 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.

  1. Novel fluoropolymer anion exchange membranes for alkaline direct methanol fuel cells.

    Science.gov (United States)

    Zhang, Yanmei; Fang, Jun; Wu, Yongbin; Xu, Hankun; Chi, Xianjun; Li, Wei; Yang, Yixu; Yan, Ge; Zhuang, Yongze

    2012-09-01

    A series of novel fluoropolymer anion exchange membranes based on the copolymer of vinylbenzyl chloride, butyl methacrylate, and hexafluorobutyl methacrylate has been prepared. Fourier transform infrared (FT-IR) spectroscopy and elemental analysis techniques are used to study the chemical structure and chemical composition of the membranes. The water uptake, ion-exchange capacity (IEC), conductivity, methanol permeability, and chemical stability of the membranes are also determined. The membranes exhibit high anionic conductivity in deionized water at 65 °C ranging from 3.86×10(-2) S cm(-1) to 4.36×10(-2) S cm(-1). The methanol permeability coefficients of the membranes are in the range of 4.21-5.80×10(-8) cm(2) s(-1) at 65 °C. The novel membranes also show good chemical and thermal stability. An open-circuit voltage of 0.7 V and a maximum power density of 53.2 mW cm(-2) of alkaline direct methanol fuel cell (ADMFC) with the membrane C, 1 M methanol, 1 M NaOH, and humidified oxygen are achieved at 65 °C. Therefore, these membranes have great potential for applications in fuel cell systems. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Cast and 3D printed ion exchange membranes for monolithic microbial fuel cell fabrication

    Science.gov (United States)

    Philamore, Hemma; Rossiter, Jonathan; Walters, Peter; Winfield, Jonathan; Ieropoulos, Ioannis

    2015-09-01

    We present novel solutions to a key challenge in microbial fuel cell (MFC) technology; greater power density through increased relative surface area of the ion exchange membrane that separates the anode and cathode electrodes. The first use of a 3D printed polymer and a cast latex membrane are compared to a conventionally used cation exchange membrane. These new techniques significantly expand the geometric versatility available to ion exchange membranes in MFCs, which may be instrumental in answering challenges in the design of MFCs including miniaturisation, cost and ease of fabrication. Under electrical load conditions selected for optimal power transfer, peak power production (mean 10 batch feeds) was 11.39 μW (CEM), 10.51 μW (latex) and 0.92 μW (Tangoplus). Change in conductivity and pH of anolyte were correlated with MFC power production. Digital and environmental scanning electron microscopy show structural changes to and biological precipitation on membrane materials following long term use in an MFC. The cost of the novel membranes was lower than the conventional CEM. The efficacy of two novel membranes for ion exchange indicates that further characterisation of these materials and their fabrication techniques, shows great potential to significantly increase the range and type of MFCs that can be produced.

  3. Performance Analysis of Air Breathing Proton Exchange Membrane Fuel Cell Stack (PEMFCS) At Different Operating Condition

    Science.gov (United States)

    Sunil, V.; Venkata siva, G.; Yoganjaneyulu, G.; Ravikumar, V. V.

    2017-08-01

    The answer for an emission free power source in future is in the form of fuel cells which combine hydrogen and oxygen producing electricity and a harmless by product-water. A proton exchange membrane (PEM) fuel cell is ideal for automotive applications. A single cell cannot supply the essential power for any application. Hence PEM fuel cell stacks are used. The effect of different operating parameters namely: type of convection, type of draught, hydrogen flow rate, hydrogen inlet pressure, ambient temperature and humidity, hydrogen humidity, cell orientation on the performance of air breathing PEM fuel cell stack was analyzed using a computerized fuel cell test station. Then, the fuel cell stack was subjected to different load conditions. It was found that the stack performs very poorly at full capacity (runs only for 30 min. but runs for 3 hours at 50% capacity). Hence, a detailed study was undertaken to maximize the duration of the stack’s performance at peak load.

  4. Analysis of heterogeneous oxygen exchange and fuel oxidation on the catalytic surface of perovskite membranes

    KAUST Repository

    Hong, Jongsup

    2013-10-01

    The catalytic kinetics of oxygen surface exchange and fuel oxidation for a perovskite membrane is investigated in terms of the thermodynamic state in the immediate vicinity of or on the membrane surface. Perovskite membranes have been shown to exhibit both oxygen perm-selectivity and catalytic activity for hydrocarbon conversion. A fundamental description of their catalytic surface reactions is needed. In this study, we infer the kinetic parameters for heterogeneous oxygen surface exchange and catalytic fuel conversion reactions, based on permeation rate measurements and a spatially resolved physical model that incorporates detailed chemical kinetics and transport in the gas-phase. The conservation equations for surface and bulk species are coupled with those of the gas-phase species through the species production rates from surface reactions. It is shown that oxygen surface exchange is limited by dissociative/associative adsorption/desorption of oxygen molecules onto/from the membrane surface. On the sweep side, while the catalytic conversion of methane to methyl radical governs the overall surface reactions at high temperature, carbon monoxide oxidation on the membrane surface is dominant at low temperature. Given the sweep side conditions considered in ITM reactor experiments, gas-phase reactions also play an important role, indicating the significance of investigating both homogeneous and heterogeneous chemistry and their coupling when examining the results. We show that the local thermodynamic state at the membrane surface should be considered when constructing and examining models of oxygen permeation and heterogeneous chemistry. © 2013 Elsevier B.V.

  5. Water removal characteristics of proton exchange membrane fuel cells using a dry gas purging method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Yeop; Kim, Hyoung-Juhn; Jang, Jong Hyun; Oh, In-Hwan; Cho, Eun Ae; Hong, Seong-Ahn; Lim, Tae-Hoon [Center for Fuel Cell Research, Korea Institute of Science and Technology, 39-1 Hawolgok-dong, Sungbuk-gu, Seoul 136-791 (Korea); Kim, Sang-Uk [Center for Fuel Cell Research, Korea Institute of Science and Technology, 39-1 Hawolgok-dong, Sungbuk-gu, Seoul 136-791 (Korea); Department of Chemical Engineering, Korea University, Anam-dong, Sungbuk-gu, Seoul 136-701 (Korea); Ko, Jaejun; Lim, Tae-Won [Fuel Cell Vehicle Team 1, Hyundai-Kia Corporate Research and Development Division, 104 Mabuk-Dong, Giheung-Gu, Yongin-Si, Gyeonggi-do 446-912 (Korea); Lee, Kwan-Young [Department of Chemical Engineering, Korea University, Anam-dong, Sungbuk-gu, Seoul 136-701 (Korea)

    2008-06-01

    Water removal from proton exchange membrane fuel cells (PEMFC) is of great importance to improve start-up ability and mitigate cell degradation when the fuel cell operates at subfreezing temperatures. In this study, we report water removal characteristics under various shut down conditions including a dry gas-purging step. In order to estimate the dehydration level of the electrolyte membrane, the high frequency resistance of the fuel cell stack was observed. Also, a novel method for measuring the amount of residual water in the fuel cell was developed to determine the amount of water removal. The method used the phase change of liquid water and was successfully applied to examine the water removal characteristics. Based on these works, the effects of several parameters such as purging time, flow rate of purging gas, operation current, and stack temperature on the amount of residual water were investigated. (author)

  6. 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

    The present work involves the development of a model for predicting the dynamic temperature of a high temperature proton exchange membrane (HTPEM) fuel cell stack. The model is developed to test different thermal control strategies before implementing them in the actual system. The test system...... is managed by running the stack at a high stoichiometric air flow. This is possible because of the polybenzimidazole (PBI) fuel cell membranes used and the very low pressure drop in the stack. The model consists of a discrete thermal model dividing the stack into three parts: inlet, middle, and end....... The temperature is predicted in these three parts, where they also are measured. The heat balance of the system involves a fuel cell model to describe the heat added by the fuel cells when a current is drawn. Furthermore the model also predicts the temperatures when heating the stack with external heating...

  7. 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.

  8. Anion- or Cation-Exchange Membranes for NaBH4/H2O2 Fuel Cells?

    Science.gov (United States)

    Sljukić, Biljana; Morais, Ana L; Santos, Diogo M F; Sequeira, César A C

    2012-07-19

    Direct borohydride fuel cells (DBFC), which operate on sodium borohydride (NaBH4) as the fuel, and hydrogen peroxide (H2O2) as the oxidant, are receiving increasing attention. This is due to their promising use as power sources for space and underwater applications, where air is not available and gas storage poses obvious problems. One key factor to improve the performance of DBFCs concerns the type of separator used. Both anion- and cation-exchange membranes may be considered as potential separators for DBFC. In the present paper, the effect of the membrane type on the performance of laboratory NaBH4/H2O2 fuel cells using Pt electrodes is studied at room temperature. Two commercial ion-exchange membranes from Membranes International Inc., an anion-exchange membrane (AMI-7001S) and a cation-exchange membrane (CMI-7000S), are tested as ionic separators for the DBFC. The membranes are compared directly by the observation and analysis of the corresponding DBFC's performance. Cell polarization, power density, stability, and durability tests are used in the membranes' evaluation. Energy densities and specific capacities are estimated. Most tests conducted, clearly indicate a superior performance of the cation-exchange membranes over the anion-exchange membrane. The two membranes are also compared with several other previously tested commercial membranes. For long term cell operation, these membranes seem to outperform the stability of the benchmark Nafion membranes but further studies are still required to improve their instantaneous power load.

  9. Anion exchange membrane

    Science.gov (United States)

    Verkade, John G; Wadhwa, Kuldeep; Kong, Xueqian; Schmidt-Rohr, Klaus

    2013-05-07

    An anion exchange membrane and fuel cell incorporating the anion exchange membrane are detailed in which proazaphosphatrane and azaphosphatrane cations are covalently bonded to a sulfonated fluoropolymer support along with anionic counterions. A positive charge is dispersed in the aforementioned cations which are buried in the support to reduce the cation-anion interactions and increase the mobility of hydroxide ions, for example, across the membrane. The anion exchange membrane has the ability to operate at high temperatures and in highly alkaline environments with high conductivity and low resistance.

  10. In-situ Monitoring of Internal Local Temperature and Voltage of Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Chi-Yuan Lee

    2010-06-01

    Full Text Available The distribution of temperature and voltage of a fuel cell are key factors that influence performance. Conventional sensors are normally large, and are also useful only for making external measurements of fuel cells. Centimeter-scale sensors for making invasive measurements are frequently unable to accurately measure the interior changes of a fuel cell. This work focuses mainly on fabricating flexible multi-functional microsensors (for temperature and voltage to measure variations in the local temperature and voltage of proton exchange membrane fuel cells (PEMFC that are based on micro-electro-mechanical systems (MEMS. The power density at 0.5 V without a sensor is 450 mW/cm2, and that with a sensor is 426 mW/cm2. Since the reaction area of a fuel cell with a sensor is approximately 12% smaller than that without a sensor, but the performance of the former is only 5% worse.

  11. On-line fault diagnostic system for proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Riascos, Luis Alberto M. [Federal University of ABC, r. Santa Adelia 166, CEP 09210-170, Santo Andre, Sao Paulo (Brazil); Simoes, Marcelo G. [Colorado School of Mines, 1500 Illinois St, 80401 Golden, CO (United States); Miyagi, Paulo E. [Escola Politecnica, University of Sao Paulo, Av. Prof. Mello Moraes 2231, CEP 05508-900, Sao Paulo (Brazil)

    2008-01-03

    In this paper, a supervisor system, able to diagnose different types of faults during the operation of a proton exchange membrane fuel cell is introduced. The diagnosis is developed by applying Bayesian networks, which qualify and quantify the cause-effect relationship among the variables of the process. The fault diagnosis is based on the on-line monitoring of variables easy to measure in the machine such as voltage, electric current, and temperature. The equipment is a fuel cell system which can operate even when a fault occurs. The fault effects are based on experiments on the fault tolerant fuel cell, which are reproduced in a fuel cell model. A database of fault records is constructed from the fuel cell model, improving the generation time and avoiding permanent damage to the equipment. (author)

  12. On-line fault diagnostic system for proton exchange membrane fuel cells

    Science.gov (United States)

    Riascos, Luis Alberto M.; Simoes, Marcelo G.; Miyagi, Paulo E.

    In this paper, a supervisor system, able to diagnose different types of faults during the operation of a proton exchange membrane fuel cell is introduced. The diagnosis is developed by applying Bayesian networks, which qualify and quantify the cause-effect relationship among the variables of the process. The fault diagnosis is based on the on-line monitoring of variables easy to measure in the machine such as voltage, electric current, and temperature. The equipment is a fuel cell system which can operate even when a fault occurs. The fault effects are based on experiments on the fault tolerant fuel cell, which are reproduced in a fuel cell model. A database of fault records is constructed from the fuel cell model, improving the generation time and avoiding permanent damage to the equipment.

  13. In-situ Monitoring of Internal Local Temperature and Voltage of Proton Exchange Membrane Fuel Cells

    Science.gov (United States)

    Lee, Chi-Yuan; Fan, Wei-Yuan; Hsieh, Wei-Jung

    2010-01-01

    The distribution of temperature and voltage of a fuel cell are key factors that influence performance. Conventional sensors are normally large, and are also useful only for making external measurements of fuel cells. Centimeter-scale sensors for making invasive measurements are frequently unable to accurately measure the interior changes of a fuel cell. This work focuses mainly on fabricating flexible multi-functional microsensors (for temperature and voltage) to measure variations in the local temperature and voltage of proton exchange membrane fuel cells (PEMFC) that are based on micro-electro-mechanical systems (MEMS). The power density at 0.5 V without a sensor is 450 mW/cm2, and that with a sensor is 426 mW/cm2. Since the reaction area of a fuel cell with a sensor is approximately 12% smaller than that without a sensor, but the performance of the former is only 5% worse. PMID:22163556

  14. Development and characterization of direct ethanol fuel cells using alkaline anion-exchange membranes

    Science.gov (United States)

    Lim, Peck Cheng

    2009-08-01

    Alkaline membrane fuel cell (AMFC) is a relatively new fuel cell technology that is generating considerable interests. It offers the electrocatalytic advantages of conventional alkaline fuel cells, and the manufacturing and cost advantages of solid polymer electrolyte fuel cells. This project was carried out to develop and characterize high performance membrane electrode assemblies (MEAs) for all-solid-state AMFCs. The primary fuel of interests is ethanol, but hydrogen was used in the development stages to facilitate the diagnostic and evaluation of the fuel cell performance. In the preliminary investigation, AMFC was assembled using off-the-shelf electrodes and anion-exchange membrane (AEM). It was found that the performance of AMFC operating on ethanol fuel was limited by a large high-frequency resistance (HFR) value. The advantage of using non-toxic ethanol fuel was also compromised by the need to add hydrazine and potassium hydroxide to the fuel blend. Subsequently, a high performance MEA was developed for an all-solid-state AMFC, in which liquid electrolyte or other additives were not required during the operation of the fuel cell. Ionomer was incorporated in the formulation of catalyst ink, and the catalyst ink was directly coated on the anion-exchange membrane (AEM). An ionomer content of 20 wt.% was found to be the optimum amount required in the catalyst layers. It was demonstrated that the AMFC generated a maximum power density of 365 mW/cm2 and 213 mW/cm 2 with the use of hydrogen/oxygen and hydrogen/pure air, respectively. The performance of the AMFC was also found to be influenced by exposure to carbon dioxide in the air. Hence, the CCMs were pre-treated in potassium hydroxide solution and pure oxygen was used to condition the fuel cell to maximize the power output from the AMFCs. Although satisfactory performance was demonstrated in the AMFC, its stability during cell operation remains a major issue. The poor stability was attributed to degradation of

  15. 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...

  16. Performance of amorphous NiNb-based alloys in a proton exchange membrane fuel cell (PEMFC)

    Energy Technology Data Exchange (ETDEWEB)

    Barranco, J.; Pierna, A.R. [Univ. of the Basque Country, San Sebastien (Spain). Dept. of Chemical Engineering and Environment

    2009-04-15

    A study was conducted to investigate the effectiveness of the spray technique of the different amorphous catalysts nickel niobate (NiNb){sub 9}9 platinum (Pt){sub 1}, and NiNb{sub 9}9 platinum (Pt) tin (Sn){sub 1}, obtained by means of the mechanical alloying, on the polymeric membrane. In particular, it examined the deposition of the catalysts on the proton exchange membrane, which is of significant importance for preparing an efficient membrane electrode assembling, which will be part of a hydrogen fuel cell. The effectiveness of spray was studied by determining the efficacy in hydrogen fuel cells. Different particle sizes were used in the catalytic ink. The deposition over the proton exchange membrane of the alloys was carried out using the airbrush technique, a process of painting the polymeric membrane which offers a homogeneous spread of the catalyst and carbon powders over the polymeric membrane. The paper described the experiment and results. The paper included a characterization of the catalysts and catalytic layers, and described the performance of the simple cells. It was concluded that both cells exhibit better behaviour when the hydrogen flow rate is low. 16 refs., 6 figs.

  17. Synthesis and Characterization of Sulfonated Polyimides as Proton Exchange Membranes for Fuel Cells

    OpenAIRE

    Gunduz, Nazan

    2001-01-01

    Series of homo- and copolyimides containing controlled degrees of sulfonic acid ion conducting pendant groups have been synthesized from both phthalic (five-) and naphthalic (six-membered) dianhydrides and appropriate wholly aromatic diamines and heterocyclic analogues. The goal is to identify thermally and hydrolytically stable ion conducting polymers (ICP) suitable as proton exchange membranes, PEM, for fuel cells. The candidate ICP's have been synthesized and characterized for molecular we...

  18. 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...

  19. Improved durability of proton exchange membrane fuel cells by introducing Sn (IV) oxide into electrodes using an ion exchange method

    Science.gov (United States)

    Poulsen, M. G.; Larsen, M. J.; Andersen, S. M.

    2017-03-01

    Electrodes of Proton Exchange Membrane Fuel Cells (PEMFCs), consisting of catalyst-coated gas diffusion layers, were subjected to an optimized ion exchange procedure, in which tin (IV) oxide (SnO2) nanoparticles were introduced into them. Both methanol and sulfuric acid were tested as ion exchange solvents. SnO2 has previously been shown to exhibit radical scavenging abilities towards radicals inside the electrocatalyst layers. Its presence inside the electrodes was confirmed using X-ray photoelectron spectroscopy and X-ray fluorescence. After exposure to an accelerated stress test in a three-electrode setup, the electrodes containing SnO2 were found to have retained approximately 73.0% of their original Pt, while only 53.2% was retained in electrodes treated identically, but without Sn. Similarly, the SnO2-treated electrodes also experienced a smaller loss in electrochemical surface area in comparison to before the accelerated stress test. A membrane electrode assembly (MEA) constructed with a SnO2-containing anode was evaluated over 500 h. The results showed remarkably reduced OCV decay rate and end of test hydrogen crossover compared to the control MEA, indicating that SnO2 aids in impeding membrane thinning and pinhole formation. The results point toward a positive effect of SnO2 on fuel cell durability, by reducing the degradation of the membrane as well as of the ionomer in the electrocatalyst layer.

  20. 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.

  1. Experimental results with a natural gas cogeneration system using a polymer exchange membrane fuel cell

    Science.gov (United States)

    Radulescu, Mihai; Lottin, Olivier; Feidt, Michel; Lombard, Christophe; Noc, David Le; Doze, Stéphane Le

    This paper reports experimental results of an investigation of five identical CHP (combined heat and power) units using PEMFC (proton exchange membrane fuel cell) and running on natural gas. The natural gas is reformed locally to produce hydrogen. The net electric power is 4.5 kWe and the installations are designed for low temperature heat recovery (6 kW at 60 °C). The performances of the CHP units are analyzed in terms of electrical, thermal and total efficiencies. The electrical efficiency is low and it is shown that this is due mostly to the reforming process and to electric losses, while fuel cell performances are fully satisfying.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Microwave Assisted Reduction of Pt-Catalyst by N-Phenyl-p-Phenylenediamine for Proton Exchange Membrane Fuel Cells

    National Research Council Canada - National Science Library

    Ming-Jer Tsai; Tar-Hwa Hsieh; Yen-Zen Wang; Ko-Shan Ho; Chia-Yun Chang

    2017-01-01

    The presence of N-phenyl-p-phenylenediamine (PPDA: a dimer of aniline) during microwave (MW) irradiation can significantly improve Pt-loading on the XC72 carbon matrix as a catalyst support of proton exchange membrane fuel cells...

  7. 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 fuel cell water balance.

  8. Preparation and properties of high performance nanocomposite proton exchange membrane for fuel cell

    Science.gov (United States)

    Lin, Yu-Feng; Yen, Chuan-Yu; Ma, Chen-Chi M.; Liao, Shu-Hang; Hung, Chih-Hung; Hsiao, Yi-Hsiu

    Various spatially enlarged organoclays were prepared by using poly(oxyproplene)-backboned quaternary ammonium salts of various molecular weights M w 230, 400 and 2000 as the intercalating agents for Na +-montmorillonite. The modified MMT was utilized to improve the compatibility with Nafion ®. Sufficient interaction of the modified MMT with Nafion ® was studied by using X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS). The performance of the Nafion ®/ m-MMT composite membranes for direct methanol fuel cell (DMFCs) was evaluated in terms of water uptake, ion exchange capacity (IEC), methanol permeability, proton conductivity, and cell performance. The methanol permeability of the composite membrane decreased with the increasing of m-MMT content. The proton conductivity of the membrane was lowered slightly from that of pristine Nafion ® membrane. These results led to an essential improvement in the single-cell performance of DMFCs.

  9. Transient Performance Behavior of Proton Exchange Membrane Fuel Cell by Configuration of Membrane and Gas Diffusion Layer

    Science.gov (United States)

    Hwang, Sang Soon; Han, Sang Seok; Lee, Pil Hyong; Park, Bong Il

    A single-phase, fully three-dimensional transient numerical simulation was performed to analyze the dynamic response of a proton exchange membrane fuel cell (PEMFC) with single serpentine flow channels. . In addition, the effects of the membrane and gas diffusion layer thickness on current density transient behavior were investigated using numerical simulation. An overshoot of current density is observed for all thicknesses of the membrane and gas diffusion layer at an abrupt change of operating voltage from 0.7 V to 0.5 V. The peak of the overshoot and the elapsed thickness time to reach to the steady state value increase with decreasing membrane thickness. It is thought that the thin membrane facilitates the transport of water and ions through the membrane, resulting in an increase in current density and humidification of the membrane. The elapsed time to reach steady state voltage become shorter and the peak of the overshoot decreases as the thickness of the gas diffusion layer decreases. We suggest that this occurs because a thick gas diffusion layer increases the distance between the current collector (as heat exchanger) and catalyst layer (as heat source), resulting in a low transport rate of heat generated by the electrochemical reaction at the catalyst layer.

  10. 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

    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...

  11. Composite fuel cell membranes

    Science.gov (United States)

    Plowman, Keith R.; Rehg, Timothy J.; Davis, Larry W.; Carl, William P.; Cisar, Alan J.; Eastland, Charles S.

    1997-01-01

    A bilayer or trilayer composite ion exchange membrane suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

  12. 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.

  13. A Review on Cold Start of Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Zhongmin Wan

    2014-05-01

    Full Text Available Successful and rapid startup of proton exchange membrane fuel cells (PEMFCs at subfreezing temperatures (also called cold start is of great importance for their commercialization in automotive and portable devices. In order to maintain good proton conductivity, the water content in the membrane must be kept at a certain level to ensure that the membrane remains fully hydrated. However, the water in the pores of the catalyst layer (CL, gas diffusion layer (GDL and the membrane may freeze once the cell temperature decreases below the freezing point (Tf. Thus, methods which could enable the fuel cell startup without or with slight performance degradation at subfreezing temperature need to be studied. This paper presents an extensive review on cold start of PEMFCs, including the state and phase changes of water in PEMFCs, impacts of water freezing on PEMFCs, numerical and experimental studies on PEMFCs, and cold start strategies. The impacts on each component of the fuel cell are discussed in detail. Related numerical and experimental work is also discussed. It should be mentioned that the cold start strategies, especially the enumerated patents, are of great reference value on the practical cold start process.

  14. 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...... media in the fuel cell, and, more importantly, the flow channels and outlet ports of a single cell in a stack. These problems may be avoided if the fuel cell operates in a way that both the anode and cathode outlet stream are exactly fully humidified, i.e. the relative humidity is at 100...... %. Such operation can conceivably be obtained by adjusting the operating conditions using dew point diagrams. In this paper numerical results will be presented of two different flow field arrangements, both using the interdigitated flow field. It will be shown that arranging the gas streams in a counter-flow, “x...

  15. Performance prediction of a proton exchange membrane fuel cell using the ANFIS model

    Energy Technology Data Exchange (ETDEWEB)

    Vural, Yasemin; Ingham, Derek B.; Pourkashanian, Mohamed [Centre for Computational Fluid Dynamics, University of Leeds, Houldsworth Building, LS2 9JT Leeds (United Kingdom)

    2009-11-15

    In this study, the performance (current-voltage curve) prediction of a Proton Exchange Membrane Fuel Cell (PEMFC) is performed for different operational conditions using an Adaptive Neuro-Fuzzy Inference System (ANFIS). First, ANFIS is trained with a set of input and output data. The trained model is then tested with an independent set of experimental data. The trained and tested model is then used to predict the performance curve of the PEMFC under various operational conditions. The model shows very good agreement with the experimental data and this indicates that ANFIS is capable of predicting fuel cell performance (in terms of cell voltage) with a high accuracy in an easy, rapid and cost effective way for the case presented. Finally, the capabilities and the limitations of the model for the application in fuel cells have been discussed. (author)

  16. 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.

  17. Proton exchange membrane with hydrophilic capillaries for elevated temperature PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Xue-Min; Mei, Ping; Mi, Yuanzhu; Gao, Lin; Qin, Shaoxiong [College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434023 (China)

    2009-01-15

    Novel water-retention proton exchange membrane of Nafion-phosphotungstic acid/mesoporous silica with hydrophilic capillaries has been fabricated to improve the elevated temperature performance of the PEM fuel cells. Due to the hydrophilic capillarity of the HPW/meso-SiO{sub 2} mesoporous structure, the Nafion-HPW/meso-SiO{sub 2} composite membrane retained 23.7 wt% of water after being dried in 100 C for 2 h and then exposed in 25 RH% gas for 2 h. As a result, under the condition of elevated temperature of 120 C and low humidity of 25 RH%, the Nafion-HPW/meso-SiO{sub 2} composite membrane showed a steady performance. (author)

  18. A small portable proton exchange membrane fuel cell and hydrogen generator for medical applications.

    Science.gov (United States)

    Adlhart, O J; Rohonyi, P; Modroukas, D; Driller, J

    1997-01-01

    Small, lightweight power sources for total artificial hearts (TAH), left ventricular assist devices (LVAD), and other medical products are under development. The new power source will provide 2 to 3 times the capacity of conventional batteries. The implications of this new power source are profound. For example, for the Heartmate LVAD, 5 to 8 hours of operation are obtained with 3 lb of lead acid batteries (Personal Communication Mr. Craig Sherman, Thermo Cardiosystems, Inc TCI 11/29/96). With the same weight, as much as 14 hours of operation appear achievable with the proton exchange membrane (PEM) fuel cell power source. Energy densities near 135 watt-hour/L are achievable. These values significantly exceed those of most conventional and advanced primary and secondary batteries. The improvement is mission dependent and even applies for the short deployment cited above. The comparison to batteries becomes even more favorable if the mission length is increased. The higher capacity requires only replacement of lightweight hydride cartridges and logistically available water. Therefore, when one spare 50 L hydride cartridge weighing 115 g is added to the reactant supply the energy density of the total system increases to 230 watt-hour/kg. This new power source is comprised of a hydrogen fueled, air-breathing PEM fuel cell and a miniature hydrogen generator (US Patent No 5,514,353). The fuel cell is of novel construction and differs from conventional bipolar PEM fuel cells by the arrangement of cells on a single sheet of ion-exchange membrane. The construction avoids the weight and volume penalty of conventional bipolar stacks. The hydrogen consumed by the fuel cell is generated load-responsively in the miniature hydrogen generator, by reacting calcium hydride with water, forming in the process hydrogen and lime. The generator is cartridge rechargeable and available in capacities providing up to several hundred watt-hours of electric power.

  19. Fouling of proton exchange membrane (PEM) deteriorates the performance of microbial fuel cell.

    Science.gov (United States)

    Xu, Juan; Sheng, Guo-Ping; Luo, Hong-Wei; Li, Wen-Wei; Wang, Long-Fei; Yu, Han-Qing

    2012-04-15

    The fouling characteristics of proton exchange membrane (PEM) in microbial fuel cell (MFC) and the resulting deterioration of MFC performance were explored in this study. It was observed that the ion exchange capacity, conductivity and diffusion coefficients of cations of PEM were reduced significantly after fouling. Imaging analysis coupled with FTIR analysis indicated that the fouling layer attached on PEM consisted of microorganisms encased in extracellular polymers and inorganic salt precipitations. The results clearly demonstrate that PEM fouling deteriorated the performance of MFCs and led to a decrease in electricity generation. Cation transfer limitation might play an important role in the deterioration of MFC performance because of the membrane fouling. This was attributed to the physical blockage of charge transfer in the MFC resulted from the membrane fouling. With the experimental results, the effect of membrane fouling on the electrical generation of MFCs was evaluated. It was found that the decreased diffusion coefficients of cations and cathodic potential loss after membrane fouling contributed mainly to the deterioration of the MFC performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Characterization of Polyethylene-Graft-Sulfonated Polyarylsulfone Proton Exchange Membranes for Direct Methanol Fuel Cell Applications.

    Science.gov (United States)

    Kim, Hyung Kyu; Zhang, Gang; Nam, Changwoo; Chung, T C Mike

    2015-12-04

    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 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.

  1. 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.

  2. 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.

  3. 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.

  4. A Bayesian network fault diagnostic system for proton exchange membrane fuel cells

    Science.gov (United States)

    Riascos, Luis Alberto M.; Simoes, Marcelo G.; Miyagi, Paulo E.

    This paper considers the effects of different types of faults on a proton exchange membrane fuel cell model (PEMFC). Using databases (which record the fault effects) and probabilistic methods (such as the Bayesian-Score and Markov Chain Monte Carlo), a graphical-probabilistic structure for fault diagnosis is constructed. The graphical model defines the cause-effect relationship among the variables, and the probabilistic method captures the numerical dependence among these variables. Finally, the Bayesian network (i.e. the graphical-probabilistic structure) is used to execute the diagnosis of fault causes in the PEMFC model based on the effects observed.

  5. A Bayesian network fault diagnostic system for proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Riascos, Luis Alberto M. [Federal University of ABC, r. Santa Adelia, 166, CEP 09210-170, Santo Andre, SP (Brazil); Simoes, Marcelo G. [Colorado School of Mines, 1500 Illinois Street, 80401, Golden, CO (United States); Miyagi, Paulo E. [Escola Politecnica, University of Sao Paulo, Av. Prof. Mello Moraes, 2231, CEP 05508-900, Sao Paulo (Brazil)

    2007-02-25

    This paper considers the effects of different types of faults on a proton exchange membrane fuel cell model (PEMFC). Using databases (which record the fault effects) and probabilistic methods (such as the Bayesian-Score and Markov Chain Monte Carlo), a graphical-probabilistic structure for fault diagnosis is constructed. The graphical model defines the cause-effect relationship among the variables, and the probabilistic method captures the numerical dependence among these variables. Finally, the Bayesian network (i.e. the graphical-probabilistic structure) is used to execute the diagnosis of fault causes in the PEMFC model based on the effects observed. (author)

  6. 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...... decreased with the increase of the ionomer. The electrode surface studies surprisingly reveal that the ionomer coverage increases linearly with the ionomer loading/content only up to a certain extent (around 30 wt.% in this case); further increase of the ionomer content triggers ionomer agglomeration, which...

  7. 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.

  8. Towards neat methanol operation of direct methanol fuel cells: a novel self-assembled proton exchange membrane.

    Science.gov (United States)

    Li, Jing; Cai, Weiwei; Ma, Liying; Zhang, Yunfeng; Chen, Zhangxian; Cheng, Hansong

    2015-04-18

    We report here a novel proton exchange membrane with remarkably high methanol-permeation resistivity and excellent proton conductivity enabled by carefully designed self-assembled ionic conductive channels. A direct methanol fuel cell utilizing the membrane performs well with a 20 M methanol solution, very close to the concentration of neat methanol.

  9. Investigation of high temperature operation of proton exchange membrane fuel cells

    Science.gov (United States)

    Adjemian, Kevork Tro

    Proton exchange membrane fuel cells (PEMFCs) have garnered much attention in the media over the past years as they can provide a clean, environmentally friendly alternative to internal combustion engines. PEMFCs also have the flexibility to operate on many different types of fuels, thereby diminishing our reliance on foreign oil. PEMFCs, however, suffer from many drawbacks which need to be overcome before mass production becomes viable. One drawback is the expense of the fuel cell system, costing several times more than existing technologies. Another problem is that if the fuel cell is running on reformed fuels, trace amounts of carbon monoxide (10 ppm) in the hydrogen gas stream will completely poison the anode electrocatalyst, killing the PEMFC. Also, as a lot of waste heat is generated, a very elaborate cooling system needs to be used, making the overall system more expensive and complex. A possible solution to both the carbon monoxide poisoning and thermal management of a PEMFC is to elevate its operating temperature above 100°C. Unfortunately, current state-of-the-art electrolytes used in PEMFCs, i.e. Nafion 115, rely on water for the conduction of protons and by elevating the temperature, water loss occurs due to evaporation resulting in inadequate PEMFC performance. This thesis delves into the modification of Nafion and similar electrolytes to permit PEMFC operation above 100°C. This was accomplished by impregnating the pores of the Nafion with hydrophilic inorganic materials-silicon oxide via sol-gel processing and various inorganic particles. By performing these modifications to the various electrolytes, several composite membranes performed exceptionally well at an operating temperature of 130°C and demonstrated carbon monoxide tolerance of up to 500 ppm. In addition, a theory on how these materials help improve the water management characteristics of Nafion was developed, laying the foundation for the development of a completely novel membrane to

  10. Anion- or Cation-Exchange Membranes for NaBH4/H2O2 Fuel Cells?

    Science.gov (United States)

    Šljukić, Biljana; Morais, Ana L.; Santos, Diogo M. F.; Sequeira, César A. C.

    2012-01-01

    Direct borohydride fuel cells (DBFC), which operate on sodium borohydride (NaBH4) as the fuel, and hydrogen peroxide (H2O2) as the oxidant, are receiving increasing attention. This is due to their promising use as power sources for space and underwater applications, where air is not available and gas storage poses obvious problems. One key factor to improve the performance of DBFCs concerns the type of separator used. Both anion- and cation-exchange membranes may be considered as potential separators for DBFC. In the present paper, the effect of the membrane type on the performance of laboratory NaBH4/H2O2 fuel cells using Pt electrodes is studied at room temperature. Two commercial ion-exchange membranes from Membranes International Inc., an anion-exchange membrane (AMI-7001S) and a cation-exchange membrane (CMI-7000S), are tested as ionic separators for the DBFC. The membranes are compared directly by the observation and analysis of the corresponding DBFC’s performance. Cell polarization, power density, stability, and durability tests are used in the membranes’ evaluation. Energy densities and specific capacities are estimated. Most tests conducted, clearly indicate a superior performance of the cation-exchange membranes over the anion-exchange membrane. The two membranes are also compared with several other previously tested commercial membranes. For long term cell operation, these membranes seem to outperform the stability of the benchmark Nafion membranes but further studies are still required to improve their instantaneous power load. PMID:24958292

  11. Metal oxide nanoparticles synthesized by pulsed laser ablation for proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Dorcioman, G.; Serban, N.; Axente, E.; Sima, F.; Ristoscu, C.; Mihailescu, I.N. [Lasers Department, National Institute for Lasers, Plasma and Radiations Physics, 409 Atomistilor Street, PO Box MG-54, RO-77125, Magurele, Ilfov (Romania); Ebrasu, D. [National Research and Development Institute for Cryogenics and Isotopic Technologies - ICSI Rm. Valcea, RO-240050 (Romania); Enculescu, I. [National Institute of Materials Physics, 105 Bis Atomistilor Street, RO-77125, Magurele, Ilfov (Romania)

    2010-12-01

    We report on the development of a modified gas diffusion layer for fuel cells consisting of a simple or teflonized carbon cloth pulsed laser deposited with metal oxide nanostructures designed to operate both as co-catalyst, and oxidic support for other electrochemically active catalysts. We selected TiO{sub 2}, ZnO and Al{sub 2}O{sub 3} doped (2 wt.%) ZnO which were uniformly distributed over the surface of gas diffusion layers in order to improve the catalytic activity, stability and lifetime, and reduce the production costs of proton exchange membrane fuel cells. We evidenced by scanning electron microscopy and energy dispersive spectroscopy that our depositions consisted of TiO{sub 2} nanoparticles while in the case of ZnO and Al{sub 2}O{sub 3} doped (2 wt.%) ZnO transparent quasi-continuous films were synthesized. (author)

  12. Electrocatalysts and their Supporting Materials for Proton Exchange Membrane Fuel Cells: Activity and Durability Studies

    DEFF Research Database (Denmark)

    Permyakova, Anastasia Aleksandrovna

    This thesis describes investigations conducted exploring the activity, stability and durability of supported nano-particulate, bulk and thin film electrocatalysts used in proton exchange membrane fuel cells (PEMFCs). The effects of different factors and conditions on the reactions involved...... in oxygen reduction, carbon monoxide and methanol electro-oxidation reactions were explored. Employed catalysts were characterized electrochemically and physiochemically using techniques such as: cyclic voltammetry, rotating disk electrode technique, SEM, TEM, EDS, XPS, TGA/DTA, Raman, XRD, FTIR-IR among...... other methods. The thesis begins with an introduction in Chapter 1 providing an overview of fuel cells, their associated reaction mechanisms, catalysts and catalysts supports. Chapter 2 presents the theoretical background to the study including equipment and the techniques used to analyse the catalysts...

  13. Nanochannel arrays as supports for proton exchange membranes in microfluidic fuel cells

    Science.gov (United States)

    Wadsworth, Chandelle J.; Yanagisawa, Naoki; Dutta, Debashis

    In this article, we report the use of nanochannel arrays as supports for proton exchange membranes in microfluidic fuel cells. The proposed design has been demonstrated by fabricating a sodium silicate based sol-gel structure within such an array bridging two microchannels containing the fuel (HCOOH) and the oxidant (KMnO 4) streams. A voltage was generated in this system by bringing two platinum electrodes in contact with these solutions and then connecting them through an external circuitry. With this current design, we have been able to generate an open circuit potential of 1.31 V and a maximum current of 31.2 μA at 25 °C.

  14. A review on the effect of proton exchange membranes in microbial fuel cells

    Directory of Open Access Journals (Sweden)

    Mostafa Rahimnejad

    2014-03-01

    Full Text Available Microorganisms in microbial fuel cells (MFC liberate electrons while the electron donors are consumed. In the anaerobic anode compartment, substrates such as carbohydrates are utilized and as a result bioelectricity is produced in the MFC. MFCs may be utilized as electricity generators in small devices such as biosensors. MFCs still face practical barriers such as low generated power and current density. Recently, a great deal of attention has been given to MFCs due to their ability to operate at mild conditions and using different biodegradable substrates as fuel. The MFC consists of anode and cathode compartments. Active microorganisms are actively catabolized to carbon sources, therefore generating bioelectricity. The produced electron is transmitted to the anode surface but the generated protons must pass through the proton exchange membrane (PEM in order to reach the cathode compartment. PEM as a key factor affecting electricity generation in MFCs has been investigated here and its importance fully discussed.

  15. 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.

  16. New load cycling strategy for enhanced durability of high temperature proton exchange membrane fuel cell

    DEFF Research Database (Denmark)

    Thomas, Sobi; Jeppesen, Christian; Steenberg, Thomas

    2017-01-01

    The objective of this paper is to develop a new operational strategy to increase the lifetime of a high temperature proton exchange membrane (HT-PEMFCs) fuel cell system by using load cycling patterns to reduce the phosphoric acid loss from the fuel cell. Four single cells were operated under...... different current cycling profile, while one cell was operated at constant current density for comparison. Polarization curves and electrochemical impedance spectroscopy measurements were recorded during the course of the tests and analysed. Two different current densities, 0.2 Acm-2 for the lower end and 0.......8 Acm-2 for the higher end, were selected for the load cycling operation. The relaxation time, which is the period of time spent at low current density operation, is varied to understand how the performance over prolonged period behaves. The duration of the high current density operation is selected...

  17. Fatigue Analysis of Proton Exchange Membrane Fuel Cell Stacks Based on Structural Stress Distribution

    Science.gov (United States)

    Wu, C. W.; Liu, B.; Wei, M. Y.; Liu, L. F.

    2017-05-01

    Proton exchange membrane fuel cell (PEMFC) stack usually undergoes various vibrations during packing, transportation and serving time, in particular for those used in the automobiles and portable equipment. Based on the Miner fatigue damage theory, the fatigue lives of the fuel cell components are first assessed. Then the component fatigue life contours of the stack are obtained under four working conditions, i.e. the three single-axial (in X-, Y- and Z-axis separately) and multi-axial random vibrations. Accordingly, the component damage under various vibrations is evaluated. The stress distribution on the gasket and PEM will greatly affect their fatigue lives. Finally, we compare the fatigue lives of 4-bolt- and 6-bolt-clamping stacks under the same total clamping force, and find that increasing the bolt number could improve the bolt fatigue lives.

  18. Novel membranes for proton exchange membrane fuel cell operation above 120°C. Final report for period October 1, 1998 to December 31, 1999

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, Supramaniam [Princeton Univ., NJ (United States); Lee, Seung-Jae [Princeton Univ., NJ (United States); Costamagna, Paola [Princeton Univ., NJ (United States); Yang, Christopher [Princeton Univ., NJ (United States); Adjemian, Kevork [Princeton Univ., NJ (United States); Bocarsly, Andrew [Princeton Univ., NJ (United States); Ogden, Joan M. [Princeton Univ., NJ (United States); Benziger, Jay [Princeton Univ., NJ (United States)

    2000-05-01

    In this project we investigated the experimental performance of three new classes of membranes, composites of perfluorosulfonic acid polymers with heteropolyacides, hydrated oxides and fast proton conducting glasses, which are promising candidates as electrolytes for proton exchange membrane fuel cells (PEMFCs), capable of operation at temperatures above 120°C. The motivations for PEMFC's operation at this temperature are to: 1) minimize the CO poisoning problem (adsorption of CO onto the platinum catalyst is greatly reduced at these temperatures), 2) find better solutions for the water and thermal management problems in proton exchange membrane fuel cells, 3) find potentially lower cost materials for proton exchange membranes. We prepared and characterized a variety of novel membrane materials. The most promising of these have been evaluated for performance in a single, small area (5cm2) fuel cell run on hydrogen and oxygen. Our results establish the technical feasibility of PEMFC operation above 120°C.

  19. Analysis and Test of a Proton Exchange Membrane Fuel Cell Power System for Space Power Applications

    Science.gov (United States)

    Vasquez, Arturo; Varanauski, Donald; Clark, Robert, Jr.

    2000-01-01

    An effort is underway to develop a prototype Proton Exchange Membrane (PEM) Fuel Cell breadboard system for fuhlre space applications. This prototype will be used to develop a comprehensive design basis for a space-rated PEM fuel cell powerplant. The prototype system includes reactant pressure regulators, ejector-based reactant pumps, a 4-kW fuel cell stack and cooling system, and a passive, membranebased oxygen / water separator. A computer model is being developed concurrently to analytically predict fluid flow in the oxidant reactant system. Fuel cells have historically played an important role in human-rated spacecraft. The Gemini and Apollo spacecraft used fuel cells for vehicle electrical power. The Space Shuttle currently uses three Alkaline Fuel Cell Powerplants (AFCP) to generate all of the vehicle's 15-20kW electrical power. Engineers at the Johnson Space Center have leveraged off the development effort ongoing in the commercial arena to develop PEM fuel cel ls for terrestrial uses. The prototype design originated from efforts to develop a PEM fuel cell replacement for the current Space Shuttle AFCP' s. In order to improve on the life and an already excellent hi storical record of reliability and safety, three subsystems were focused on. These were the fuel cell stack itself, the reactant circulation devices, and reactant / product water separator. PEM fuel cell stack performance is already demonstrating the potential for greater than four times the useful life of the current Shuttle's AFCP. Reactant pumping for product water removal has historically been accomplished with mechanical pumps. Ejectors offer an effective means of reactant pumping as well as the potential for weight reduction, control simplification, and long life. Centrifugal water separation is used on the current AFCP. A passive, membrane-based water separator offers compatibility with the micro-gravity environment of space, and the potential for control simplification, elimination of

  20. Performance of gas diffusion layer from coconut waste for proton exchange membrane fuel cell

    Science.gov (United States)

    Widodo, H.; Destyorini, F.; Insiyanda, D. R.; Subhan, A.

    2017-04-01

    The performance of Gas Diffusion Layer (GDL) synthesized from coconut waste. Gas Diffusion Layer (GDL), produced from coconut waste, as a part of Proton Exchange Membrane Fuel Cell (PEMFC) component, has been characterized. In order to know the performance, the commercial products were used as the remaining parts of PEMFC. The proposed GDL possesses 69% porosity for diffusion of Hydrogen fuel and Oxygen, as well as for transporting electron. With the electrical conductivity of 500 mS.cm-1, it also has hydrophobic properties, which is important to avoid the reaction with water, with the contact angle of 139°. The 5 × 5 cm2 GDL paper was co-assembled with the catalyst, Nafion membrane, bipolar plate, current collector, end plate to obtain single Stack PEMFC. The performance was examined by flowing fuel and gas with the flow rate of 500 and 1000 ml.min-1, respectively, and analyse the I-V polarization curve. The measurements were carried out at 30, 35, and 40°C for 5 cycles to ensure the repeatability. The results shows that the current density and the maximum power density reaches 203 mA.cm-2 and 143 mW.cm-2, respectively, with a given voltage 0.6 V, at 40°C.

  1. Numerical simulation of proton exchange membrane fuel cells at high operating temperature

    Science.gov (United States)

    Peng, Jie; Lee, Seung Jae

    A three-dimensional, single-phase, non-isothermal numerical model for proton exchange membrane (PEM) fuel cell at high operating temperature (T ≥ 393 K) was developed and implemented into a computational fluid dynamic (CFD) code. The model accounts for convective and diffusive transport and allows predicting the concentration of species. The heat generated from electrochemical reactions, entropic heat and ohmic heat arising from the electrolyte ionic resistance were considered. The heat transport model was coupled with the electrochemical and mass transport models. The product water was assumed to be vaporous and treated as ideal gas. Water transportation across the membrane was ignored because of its low water electro-osmosis drag force in the polymer polybenzimidazole (PBI) membrane. The results show that the thermal effects strongly affect the fuel cell performance. The current density increases with the increasing of operating temperature. In addition, numerical prediction reveals that the width and distribution of gas channel and current collector land area are key optimization parameters for the cell performance improvement.

  2. Sulfonation of cPTFE Film grafted Styrene for Proton Exchange Membrane Fuel Cell

    Directory of Open Access Journals (Sweden)

    Yohan Yohan

    2010-10-01

    Full Text Available Sulfonation of γ-ray iradiated and styrene-grafted crosslinked polytetrafluoroethylene film (cPTFE-g-S film have been done. The aim of the research is to make hydropyl membrane as proton exchange membrane fuel cell. Sulfonation was prepared with chlorosulfonic acid in chloroethane under various conditions. The impact of the percent of grafting, the concentration of chlorosulfonic acid, the reaction time,and the reaction temperature on the properties of sulfonated film is examinated. The results show that sulfonation of surface-grafted films is incomplete at room  temperature. The increasing of concentration of chlorosulfonic acid and reaction temperature accelerates the reaction but they also add favor side reactions. These will lead to decreasing of the ion-exchange capacity, water uptake, and proton conductivity but increasing the resistance to oxidation in a perhidrol solution. The cPTFE-g-SS membrane which is resulted has stability in a H2O2 30% solution for 20 hours.

  3. Analytical Investigation and Improvement of Performance of a Proton Exchange Membrane (Pem) Fuel Cell in Mobile Applications

    OpenAIRE

    Khazaee I.

    2015-01-01

    In this study, the performance of a proton exchange membrane fuel cell in mobile applications is investigated analytically. At present the main use and advantages of fuel cells impact particularly strongly on mobile applications such as vehicles, mobile computers and mobile telephones. Some external parameters such as the cell temperature (Tcell ) , operating pressure of gases (P) and air stoichiometry (λair ) affect the performance and voltage losses in the PEM fuel cell. Because of the exis...

  4. Modelling, simulation and control of a proton exchange membrane fuel cell (PEMFC) power system

    Energy Technology Data Exchange (ETDEWEB)

    Al-Dabbagh, Ahmad W.; Lu, Lixuan; Mazza, Antonio [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, Oshawa, ON L1H 7K4 (Canada)

    2010-05-15

    Fuel cell power systems are emerging as promising means of electrical power generation on account of the associated clean electricity generation process, as well as their suitability for use in a wide range of applications. During the design stage, the development of a computer model for simulating the behaviour of a system under development can facilitate the experimentation and testing of that system's performance. Since the electrical power output of a fuel cell stack is seldom at a suitable fixed voltage, conditioning circuits and their associated controllers must be incorporated in the design of the fuel cell power system. This paper presents a MATLAB/Simulink model that simulates the behaviour of a Proton Exchange Membrane Fuel Cell (PEMFC), conditioning circuits and their controllers. The computer modelling of the PEMFC was based on adopted mathematical models that describe the fuel cell's operational voltage, while accounting for the irreversibilities associated with the fuel cell stack. The conditioning circuits that are included in the Simulink model are a DC-DC converter and DC-AC inverter circuits. These circuits are the commonly utilized power electronics circuits for regulating and conditioning the output voltage from a fuel cell stack. The modelling of the circuits is based on relationships that govern the output voltage behaviour with respect to their input voltages, switching duty cycle and efficiency. In addition, this paper describes a Fuzzy Logic Controller (FLC) design that is aimed at regulating the conditioning circuits to provide and maintain suitable electrical power for a wide range of applications. The model presented demonstrates the use of the FLC in conjunction with the PEMFC Simulink model and that it is the basis for more in-depth analytical models. (author)

  5. 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...... impedance spectroscopy (EIS) technique has been used, allowing the performance of a fuel cell diagnostic when the fuel cell stack does not contain any hydrogen, which would otherwise not be possible. The results appeared to confirm that measuring the impedance of an entire fuel cell stack could be a viable...

  6. 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

  7. 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.

  8. Proton exchange membrane micro fuel cells on 3D porous silicon gas diffusion layers

    Science.gov (United States)

    Kouassi, S.; Gautier, G.; Thery, J.; Desplobain, S.; Borella, M.; Ventura, L.; Laurent, J.-Y.

    2012-10-01

    Since the 90's, porous silicon has been studied and implemented in many devices, especially in MEMS technology. In this article, we present a new approach to build miniaturized proton exchange membrane micro-fuel cells using porous silicon as a hydrogen diffusion layer. In particular, we propose an innovative process to build micro fuel cells from a “corrugated iron like” 3D structured porous silicon substrates. This structure is able to increase up to 40% the cell area keeping a constant footprint on the silicon wafer. We propose here a process route to perform electrochemically 3D porous gas diffusion layers and to deposit fuel cell active layers on such substrates. The prototype peak power performance was measured to be 90 mW cm-2 in a “breathing configuration” at room temperature. These performances are less than expected if we compare with a reference 2D micro fuel cell. Actually, the active layer deposition processes are not fully optimized but this prototype demonstrates the feasibility of these 3D devices.

  9. 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.

  10. 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.

  11. Controlling fuel crossover and hydration in ultrathin proton exchange membrane-based fuel cells using Pt-nanosheet catalysts

    DEFF Research Database (Denmark)

    Wang, Rujie; Zhang, Wenjing (Angela); He, Gaohong

    2014-01-01

    and provided in situ hydration inside Nafion membranes to maintain their proton conductivity level. Furthermore, LDH nanosheets reinforced the Nafion membranes, with 181% improvement in tensile modulus and 166% improvement in yield strength. In a hydrogen fuel cell running with dry fuel, the membrane...

  12. 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...

  13. 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.

  14. Graphene-supported platinum catalyst prepared with ionomer as surfactant for anion exchange membrane fuel cells

    Science.gov (United States)

    Zeng, L.; Zhao, T. S.; An, L.; Zhao, G.; Yan, X. H.; Jung, C. Y.

    2015-02-01

    In this work, we have synthesized an ionomer-coated graphene-supported platinum catalyst for anion exchange membrane fuel cells. Unlike the common surfactant stabilized colloidal method, we employ a home-made anion exchange ionomer (AEI), namely quaternary ammonia poly (2, 6-dimethyl-1, 4-phenylene oxide) (QAPPO), as the surfactant. The AEI coated on reduced graphene oxide (rGO) surfaces serves as a stabilizer to anchor the platinum precursor on rGO surfaces due to electrostatic interactions. As a result, platinum nanoparticles (Pt NPs) can be easily deposited onto rGO surfaces with a uniform distribution. The remarkable feature of the present synthesis method is that the surfactant, the coated AEI, does not need to be removed from the catalyst, but serves as hydroxide-conductive paths in the catalyst layer, leading to enhanced triple phase boundaries. It is demonstrated that the use of the catalyst obtained with the present method enables a H2/O2 AEMFC to yield a peak power density of 264.8 mW cm-2 at 60 °C, which is 30% higher than that produced from the same fuel cell but with the use of the catalyst synthesized by the conventional synthesis method.

  15. Using adaptive neuro fuzzy inference system (ANFIS) for proton exchange membrane fuel cell (PEMFC) performance modeling

    Energy Technology Data Exchange (ETDEWEB)

    Rezazadeh, S.; Mirzaee, I. [Urmia Univ., Urmia (Iran, Islamic Republic of); Mehrabi, M. [University of Pretoria, Pretoria (South Africa)

    2012-11-15

    In this paper, an adaptive neuro fuzzy inference system (ANFIS) is used for modeling proton exchange membrane fuel cell (PEMFC) performance using some numerically investigated and compared with those to experimental results for training and test data. In this way, current density I (A/cm{sup 2}) is modeled to the variation of pressure at the cathode side P{sup C} (atm), voltage V (V), membrane thickness (mm), Anode transfer coefficient {alpha}{sup an}, relative humidity of inlet fuel RH{sup a} and relative humidity of inlet air RH{sup c} which are defined as input (design) variables. Then, we divided these data into train and test sections to do modeling. We instructed ANFIS network by 80% of numerical validated data. 20% of primary data which had been considered for testing the appropriateness of the models was entered ANFIS network models and results were compared by three statistical criterions. Considering the results, it is obvious that our proposed modeling by ANFIS is efficient and valid and it can be expanded for more general states.

  16. Nitrogen-Coordinated Single Cobalt Atom Catalysts for Oxygen Reduction in Proton Exchange Membrane Fuel Cells.

    Science.gov (United States)

    Wang, Xiao Xia; Cullen, David A; Pan, Yung-Tin; Hwang, Sooyeon; Wang, Maoyu; Feng, Zhenxing; Wang, Jingyun; Engelhard, Mark H; Zhang, Hanguang; He, Yanghua; Shao, Yuyan; Su, Dong; More, Karren L; Spendelow, Jacob S; Wu, Gang

    2018-01-24

    Due to the Fenton reaction, the presence of Fe and peroxide in electrodes generates free radicals causing serious degradation of the organic ionomer and the membrane. Pt-free and Fe-free cathode catalysts therefore are urgently needed for durable and inexpensive proton exchange membrane fuel cells (PEMFCs). Herein, a high-performance nitrogen-coordinated single Co atom catalyst is derived from Co-doped metal-organic frameworks (MOFs) through a one-step thermal activation. Aberration-corrected electron microscopy combined with X-ray absorption spectroscopy virtually verifies the CoN4 coordination at an atomic level in the catalysts. Through investigating effects of Co doping contents and thermal activation temperature, an atomically Co site dispersed catalyst with optimal chemical and structural properties has achieved respectable activity and stability for the oxygen reduction reaction (ORR) in challenging acidic media (e.g., half-wave potential of 0.80 V vs reversible hydrogen electrode (RHE). The performance is comparable to Fe-based catalysts and 60 mV lower than Pt/C -60 μg Pt cm-2 ). Fuel cell tests confirm that catalyst activity and stability can translate to high-performance cathodes in PEMFCs. The remarkably enhanced ORR performance is attributed to the presence of well-dispersed CoN4 active sites embedded in 3D porous MOF-derived carbon particles, omitting any inactive Co aggregates. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. 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)

  18. Steady state and transient simulation of anion exchange membrane fuel cells

    Science.gov (United States)

    Dekel, Dario R.; Rasin, Igal G.; Page, Miles; Brandon, Simon

    2018-01-01

    We present a new model for anion exchange membrane fuel cells. Validation against experimental polarization curve data is obtained for current densities ranging from zero to above 2 A cm-2. Experimental transient data is also successfully reproduced. The model is very flexible and can be used to explore the system's sensitivity to a wide range of material properties, cell design specifications, and operating parameters. We demonstrate the impact of gas inlet relative humidity (RH), operating current density, ionomer loading and ionomer ion exchange capacity (IEC) values on cell performance. In agreement with the literature, high air RH levels are shown to improve cell performance. At high current densities (>1 A cm-2) this effect is observed to be especially significant. Simulated hydration number distributions across the cell reveal the related critical dependence of cathode hydration on air RH and current density values. When exploring catalyst layer design, optimal intermediate ionomer loading values are demonstrated. The benefits of asymmetric (cathode versus anode) electrode design are revealed, showing enhanced performance using higher cathode IEC levels. Finally, electrochemical reaction profiles across the electrodes uncover inhomogeneous catalyst utilization. Specifically, at high current densities the cathodic reaction is confined to a narrow region near the membrane.

  19. Effects of sulfonated polyether-etherketone (SPEEK) and composite membranes on the proton exchange membrane fuel cell (PEMFC) performance

    Energy Technology Data Exchange (ETDEWEB)

    Erce Senguel; Erdener, Huelya; Akay, R. Gueltekin; Yuecel, Hayrettin; Eroglu, inci [Chemical Engineering Department, Middle East Technical University, 06531 Ankara (Turkey); Bac, Nurcan [Chemical Engineering Department, Yeditepe University, 34755 Istanbul (Turkey)

    2009-05-15

    Sulfonated polyether-etherketone (SPEEK) has a potential for proton exchange fuel cell applications. However, its conductivity and thermohydrolytic stability should be improved. In this study the proton conductivity was improved by addition of an aluminosilicate, zeolite beta. Moreover, thermohydrolytic stability was improved by blending poly-ether-sulfone (PES). Sulfonated polymers were characterized by H-NMR. Composite membranes prepared were characterized by Electrochemical Impedance Spectroscopy (EIS) for their proton conductivity. Degree of sulfonation (DS) values calculated from H-NMR results, and both proton conductivity and thermohydrolytic stability was found to strongly depend on DS. Therefore, DS values were controlled time in the range of 55-75% by controlling the reaction time. Zeolite beta fillers at different SiO{sub 2}/Al{sub 2}O{sub 3} ratios (20, 30, 40, 50) were synthesized and characterized by XRD, EDX, TGA, and SEM. The proton conductivity of plain SPEEK membrane (DS = 68%) was 0.06 S/cm at 60 C and the conductivity of the composite membrane containing of zeolite beta filled SPEEK was found to increase to 0.13 S/cm. Among the zeolite Beta/SPEEK composite membranes the best conductivity results were achieved with zeolite beta having a SiO{sub 2}/Al{sub 2}O{sub 3} ratio of 50 at 10 wt% loading. Single fuel cell tests performed at different operating temperatures indicated that SPES/SPEEK membrane is more stable hydrodynamically and also performed better than pristine SPEEK membranes which swell excessively. Membrane electrode assemblies (MEAs) were prepared by gas diffusion layer (GDL) spraying method. The highest performance of 400 mA/cm{sup 2} was obtained for SPEEK membrane (DS 56%) at 0.6 V for a H{sub 2}-O{sub 2}/PEMFC working at 1 atm and 70 C. At the same conditions Nafion {sup registered} 112 gave 660 mA/cm{sup 2}. It was observed that the operating temperature can be increased up to 90 C with polymer blends containing poly

  20. A Review of Metallic Bipolar Plates for Proton Exchange Membrane Fuel Cells: Materials and Fabrication Methods

    Directory of Open Access Journals (Sweden)

    Shahram Karimi

    2012-01-01

    Full Text Available The proton exchange membrane fuel cell offers an exceptional potential for a clean, efficient, and reliable power source. The bipolar plate is a key component in this device, as it connects each cell electrically, supplies reactant gases to both anode and cathode, and removes reaction products from the cell. Bipolar plates have been fabricated primarily from high-density graphite, but in recent years, much attention has been paid to developing cost-effective and feasible alternative materials. Two different classes of materials have attracted attention: metals and composites. This paper offers a comprehensive review of the current research being carried out on metallic bipolar plates, covering materials and fabrication methods.

  1. 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)

  2. High-Resolution Neutron Radiography Analysis of Proton Exchange Membrane Fuel Cells

    Science.gov (United States)

    Hussey, D. S.; Jacobson, D. L.

    Neutron radiography enables direct visualization and quantification of many water transport phenomena in proton exchange membrane fuel cells (PEMFCs). The advantage of the technique is that neutrons have a long penetration length through most common PEMFC materials of construction (with a 1/e length of about 11 cm for aluminum), while having a relatively short 1/e length for water (of order 3 mm). This sensitivity to water enables precise measurements via neutron radiography of the water content in an operating PEMFC that are primarily limited by systematic measurement uncertainties. Recent advances in the spatial resolution of neutron detector technology enable direct measurement of the through-plane water content. This new data provides gas diffusion layer water profiles that can serve as input or comparison data for a large class of one-dimensional PEMFC models. In this article, the technique of neutron radiography is discussed, with an emphasis on the quantitative image analysis of the through-plane water content.

  3. Microscopy studies on pronton exchange membrane fuel cell electrodes with different ionomer contents

    DEFF Research Database (Denmark)

    Ma, Shuang; Solterbeck, Claus Henning; Odgaard, Madeleine

    2009-01-01

    content in the catalyst layer. Transmission electron microscopy (TEM) was carried out on selective electrodes to provide additional information and confirmed with the AFM results. Cyclic voltammetry (CV) showed that the electrode containing 30 wt.% ionomer has maximum catalyst utilization.......Proton Exchange Membrane (PEM) fuel cell electrodes with different ionomer contents were studied with various microscopic techniques. The morphology and surface potential were examined by Atomic Force Microscopy (AFM) and Kelvin Probe Microscopy (KPM), respectively. The particulate nature...... in high ionomer content electrodes. The surface potential images showed distinct difference to the topography images. The overall grain size was seen to increase, the pore volume to decrease, the surface roughness to decrease, and the surface potential variation to increase with the increase of ionomer...

  4. Double cross-linked polyetheretherketone proton exchange membrane for fuel cell

    CSIR Research Space (South Africa)

    Luo, H

    2012-04-01

    Full Text Available . The performance of direct methanol fuel cell was slightly improved as compared to Nafion® 117 due to its low methanol permeability. The results indicated that the double cross-linked membrane is a promising candidate for the polymer electrolyte membrane fuel cell...

  5. Use of Multi-Functional Flexible Micro-Sensors for in situ Measurement of Temperature, Voltage and Fuel Flow in a Proton Exchange Membrane Fuel Cell

    Science.gov (United States)

    Lee, Chi-Yuan; Chan, Pin-Cheng; Lee, Chung-Ju

    2010-01-01

    Temperature, voltage and fuel flow distribution all contribute considerably to fuel cell performance. Conventional methods cannot accurately determine parameter changes inside a fuel cell. This investigation developed flexible and multi-functional micro sensors on a 40 μm-thick stainless steel foil substrate by using micro-electro-mechanical systems (MEMS) and embedded them in a proton exchange membrane fuel cell (PEMFC) to measure the temperature, voltage and flow. Users can monitor and control in situ the temperature, voltage and fuel flow distribution in the cell. Thereby, both fuel cell performance and lifetime can be increased. PMID:22163545

  6. 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)

  7. 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.

  8. Free air breathing proton exchange membrane fuel cell: Thermal behavior characterization near freezing temperature

    Science.gov (United States)

    Higuita Cano, Mauricio; Kelouwani, Sousso; Agbossou, Kodjo; Dubé, Yves

    2014-01-01

    A free air breathing fuel cell thermal model is developed. This proton exchange membrane fuel cell (PEMFC) has been selected as the basis for the study due to its use in automotive applications. The blowers integrated to the stack provide the required air flow for hydrogen oxidation as well as the fluid for the stack thermal regulation. Hence, their controls are a key point for keeping the system to maximum efficiency. Using well-known fuel cell electrochemistry, a dynamic thermal model near freezing temperature, which includes the stack physical parameters, is developed and validated. In addition to these parameters, only the inlet and outlet air temperatures are used to derive the model. Experimental validation with a real 1 kW free air breathing PEMFC has demonstrated that the model can reasonably track the stack internal temperature with a maximum deviation between the observed and the estimated temperatures of 5%. Therefore, the proposed method will allow the development of efficient blower management systems for PEMFC efficiency improvement.

  9. 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.

  10. Conceptual design report for a Direct Hydrogen Proton Exchange Membrane Fuel Cell for transportation application

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-05

    This report presents the conceptual design for a Direct-Hydrogen-Fueled Proton Exchange Membrane (PEM) Fuel Cell System for transportation applications. The design is based on the initial selection of the Chrysler LH sedan as the target vehicle with a 50 kW (gross) PEM Fuel Cell Stack (FCS) as the primary power source, a battery-powered Load Leveling Unit (LLU) for surge power requirements, an on-board hydrogen storage subsystem containing high pressure gaseous storage, a Gas Management Subsystem (GMS) to manage the hydrogen and air supplies for the FCS, and electronic controllers to control the electrical system. The design process has been dedicated to the use of Design-to-Cost (DTC) principles. The Direct Hydrogen-Powered PEM Fuel Cell Stack Hybrid Vehicle (DPHV) system is designed to operate on the Federal Urban Driving Schedule (FUDS) and Hiway Cycles. These cycles have been used to evaluate the vehicle performance with regard to range and hydrogen usage. The major constraints for the DPHV vehicle are vehicle and battery weight, transparency of the power system and drive train to the user, equivalence of fuel and life cycle costs to conventional vehicles, and vehicle range. The energy and power requirements are derived by the capability of the DPHV system to achieve an acceleration from 0 to 60 MPH within 12 seconds, and the capability to achieve and maintain a speed of 55 MPH on a grade of seven percent. The conceptual design for the DPHV vehicle is shown in a figure. A detailed description of the Hydrogen Storage Subsystem is given in section 4. A detailed description of the FCS Subsystem and GMS is given in section 3. A detailed description of the LLU, selection of the LLU energy source, and the power controller designs is given in section 5.

  11. Channel geometric scales effect on performance and optimization for serpentine proton exchange membrane fuel cell (PEMFC)

    Science.gov (United States)

    Youcef, Kerkoub; Ahmed, Benzaoui; Ziari, Yasmina; Fadila, Haddad

    2017-02-01

    A three dimensional computational fluid dynamics model is proposed in this paper to investigate the effect of flow field design and dimensions of bipolar plates on performance of serpentine proton exchange membrane fuel cell (PEMFC). A complete fuel cell of 25 cm2 with 25 channels have been used. The aim of the work is to investigate the effect of flow channels and ribs scales on overall performance of PEM fuel cell. Therefore, geometric aspect ratio parameter defined as (width of flow channel/width of rib) is used. Influences of the ribs and openings current collector scales have been studied and analyzed in order to find the optimum ratio between them to enhance the production of courant density of PEM fuel cell. Six kind of serpentine designs have been used in this paper included different aspect ratio varying from 0.25 to 2.33 while the active surface area and number of channels are keeping constant. Aspect ratio 0.25 corresponding of (0.4 mm channel width/ 1.6mm ribs width), and Aspect ratio2.33 corresponding of (0.6 mm channel width/ 1.4mm ribs width. The results show that the best flow field designs (giving the maximum density of current) are which there dimensions of channels width is minimal and ribs width is maximal (Γ≈0.25). Also decreasing width of channels enhance the pressure drop inside the PEM fuel cell, this causes an increase of gazes velocity and enhance convection process, therefore more power generation.

  12. Impact of heat and water management on proton exchange membrane fuel cells degradation in automotive application

    Science.gov (United States)

    Nandjou, F.; Poirot-Crouvezier, J.-P.; Chandesris, M.; Blachot, J.-F.; Bonnaud, C.; Bultel, Y.

    2016-09-01

    In Proton Exchange Membrane Fuel Cells, local temperature is a driving force for many degradation mechanisms such as hygrothermal deformation and creep of the membrane, platinum dissolution and bipolar plates corrosion. In order to investigate and quantify those effects in automotive application, durability testing is conducted in this work. During the ageing tests, the local performance and temperature are investigated using in situ measurements of a printed circuit board. At the end of life, post-mortem analyses of the aged components are conducted. The experimental results are compared with the simulated temperature and humidity in the cell obtained from a pseudo-3D multiphysics model in order to correlate the observed degradations to the local conditions inside the stack. The primary cause of failure in automotive cycling is pinhole/crack formation in the membrane, induced by high variations of its water content over time. It is also observed that water condensation largely increases the probability of the bipolar plates corrosion while evaporation phenomena induce local deposits in the cell.

  13. Review of ambient CO2 effect on anion exchange membranes fuel cells.

    Science.gov (United States)

    Ziv, Noga; Mustain, William E; Dekel, Dario R

    2018-01-27

    Over the past 10 years, there has been a surge of interest in anion exchange membrane fuel cells (AEMFCs) as a potentially lower cost alternative to proton exchange membrane fuel cells (PEMFCs). Recent work has shown that AEMFCs achieved nearly identical performance to state-of-the-art PEMFCs; however, much of that data has been collected while feeding CO2-free air or pure oxygen to the cathode. Usually, removing CO2 from the oxidant is done in order to avoid the detrimental effect of CO2 on AEMFC performance, due to carbonation where CO2 reacts with the OH- anions, forming HCO3- and CO32-. In spite of the crucial importance of this topic for the future development and commercialization of AEMFCs, unfortunately there have been very few investigations devoted to this phenomenon and its effects. Much of the data available in the literature is widely spread out and there currently does not exist a resource that researchers in the field, or those looking to enter the field, can use as a reference text that explains the complex influence of CO2 and HCO3-/CO32- on all aspects of AEMFC performance. The purpose of this review is to summarize the experimental and theoretical work that has been reported in the literature for the effect of ambient CO2 on AEMFCs. This systematic review intends to create a single comprehensive account of what is known regarding how CO2 behaves in AEMFCs to date, as well as identify the most important areas for future work in this field. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. 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.

  15. 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

    , 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......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....

  16. 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

    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...

  17. Membrane electrode assembly with enhanced platinum utilization for high temperature proton exchange membrane fuel cell prepared by catalyst coating membrane method

    Science.gov (United States)

    Liang, Huagen; Su, Huaneng; Pollet, Bruno G.; Linkov, Vladimir; Pasupathi, Sivakumar

    2014-11-01

    In this work, membrane electrode assemblies (MEAs) prepared by catalyst coating membrane (CCM) method are investigated for reduced platinum (Pt) loading and improved Pt utilization of high temperature proton exchange membrane fuel cell (PEMFC) based on phosphoric acid (PA)-doped poly(2,5-benzimidazole) (AB-PBI) membrane. The results show that CCM method exhibits significantly higher cell performance and Pt-specific power density than that of MEAs prepared with conventional gas diffusion electrode (GDE) under a low Pt loading level. In-suit cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) show that the MEAs prepared by the CCM method have a higher electrochemical surface area (ECSA), low cell ohmic resistance and low charge transfer resistance as compared to those prepared with GDEs at the same Pt loading.

  18. Physico-chemical study of the degradation of membrane-electrode assemblies in a proton exchange membrane fuel cell stack

    Science.gov (United States)

    Ferreira-Aparicio, P.; Gallardo-López, B.; Chaparro, A. M.; Daza, L.

    A proton exchange membrane fuel cell stack integrated by 8-elements has been evaluated in an accelerated stress test. The application of techniques such as TEM analyses of ultramicrotome-sliced sections of some samples and XRD, XPS and TGA of spent electrodes reveal the effects of several degradation processes contributing to reduce the cells performance. The reduction of the Pt surface area at the cathode is favored by the oxidation of carbon black agglomerates in the catalytic layer, the agglomeration of Pt particles and by the partial dissolution of Pt, which migrates towards the anode and precipitates within the membrane. In the light of the TEM, EDAX and XPS results, two combined effects are probably responsible of the increase of the internal resistance of the stack cells: (i) a lower proton conductivity of the membranes due to the high affinity of the sulfonic acid groups for ions originated from Pt crystallites and other peripherical elements such as the silicone elastomeric gaskets and (ii) the increment of electrically isolated islands in the cathode gas diffusion electrodes resulting from carbon corrosion and the degradation of the perfluorinated polymers. Water accumulation and inhomogeneous gas distribution throughout the stack cells originate different degradation rates in them.

  19. 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...

  20. Doping phosphoric acid in polybenzimidazole membranes for high temperature proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

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

    2007-01-01

    Polybenzimidazole (PBI) membranes were doped in phosphoric acid solutions of different concentrations at room temperature. The doping chemistry was studied using the Scatchard method. The energy distribution of the acid complexation in polymer membranes is heterogeneous, that is, there are two...

  1. Plasma-grafted alkaline anion-exchange membranes based on polyvinyl chloride for potential application in direct alcohol fuel cell

    Science.gov (United States)

    Hu, Jue; Zhang, Chengxu; Cong, Jie; Toyoda, Hirotaka; Nagatsu, Masaaki; Meng, Yuedong

    2011-05-01

    Plasma grafting is employed to prepare alkaline anion-exchange membranes in this study. The attenuated total reflection Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermo gravimetric analysis demonstrate that the benzyltrimethylammonium cationic groups are successfully introduced into the polyvinyl chloride matrix via plasma grafting, quaternization and alkalization. The plasma-grafted alkaline anion-exchange membrane exhibits a satisfactory ionic exchange capacity (1.01 mmol g-1), thermal stability, mechanical property, ionic conductivity (0.0145 S cm-1) and methanol permeability (9.59 × 10-12 m2 s-1), suggesting a great potential for application in direct alcohol fuel cells. The open circuit voltage of air-breathing ADAFC using plasma-grafted alkaline anion-exchange membrane is 0.796 V with 1 M EtOH solution at ambient temperature.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-09-01

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

  3. Proton Exchange Membrane fuel cell development with lightweight component materials, phase 1

    Science.gov (United States)

    Abens, Sandors

    1995-07-01

    Although the Proton Exchange Membrane (PEM) fuel cell is a leading candidate for an automobile power source through meeting the zero emission requirement, its power density is currently an order of magnitude below the 400 W/kg criterion proposed by the Department of Energy. The major contributors to stack weight are the bipolar gas distribution plates. This effort, performed jointly by Energy Research Corporation (ERC) and Texas A&M University (TAM U), focused on lightweight alternative bipolar plate materials and designs. The electronic conductivity of various candidate materials was evaluated. The emphasis was on conductive plastic materials and porous graphite. Several plastic materials with specific resistance between 0.5 and 0.8 ohm/cm were identified. Preliminary evaluation of lightweight materials was performed in single cell tests. The emphasis was on atmospheric pressure and internally humidified cell operation as a potential means of system simplification and reduction of PEM fuel cell ancillary equipment complexity and weight. The performance of single cells was nearly the same at 1 and 3 atm pressure. At a cell potential of O.6V, a current density of 230 mA/sq cm was reached at 1.7 stoichiometric air flow rate. With lightweight bipolar plates, the DOE power density target may be achieved with unpressurized, internally humidified cell stacks.

  4. Proton exchange membrane materials for the advancement of direct methanol fuel-cell technology

    Science.gov (United States)

    Cornelius, Christopher J [Albuquerque, NM

    2006-04-04

    A new class of hybrid organic-inorganic materials, and methods of synthesis, that can be used as a proton exchange membrane in a direct methanol fuel cell. In contrast with Nafion.RTM. PEM materials, which have random sulfonation, the new class of materials have ordered sulfonation achieved through self-assembly of alternating polyimide segments of different molecular weights comprising, for example, highly sulfonated hydrophilic PDA-DASA polyimide segment alternating with an unsulfonated hydrophobic 6FDA-DAS polyimide segment. An inorganic phase, e.g., 0.5 5 wt % TEOS, can be incorporated in the sulfonated polyimide copolymer to further improve its properties. The new materials exhibit reduced swelling when exposed to water, increased thermal stability, and decreased O.sub.2 and H.sub.2 gas permeability, while retaining proton conductivities similar to Nafion.RTM.. These improved properties may allow direct methanol fuel cells to operate at higher temperatures and with higher efficiencies due to reduced methanol crossover.

  5. Halloysite-derived nitrogen doped carbon electrocatalysts for anion exchange membrane fuel cells

    Science.gov (United States)

    Lu, Yaxiang; Wang, Lianqin; Preuß, Kathrin; Qiao, Mo; Titirici, Maria-Magdalena; Varcoe, John; Cai, Qiong

    2017-12-01

    Developing the low-cost, highly active carbonaceous materials for oxygen reduction reaction (ORR) catalysts has been a high-priority research direction for durable fuel cells. In this paper, two novel N-doped carbonaceous materials with flaky and rod-like morphology using the natural halloysite as template are obtained from urea nitrogen source as well as glucose (denoted as GU) and furfural (denoted as FU) carbon precursors, respectively, which can be directly applied as metal-free electrocatalysts for ORR in alkaline electrolyte. Importantly, compared with a benchmark Pt/C (20wt%) catalyst, the as-prepared carbon catalysts demonstrate higher retention in diffusion limiting current density (after 3000 cycles) and enhanced methanol tolerances with only 50-60mV negative shift in half-wave potentials. In addition, electrocatalytic activity, durability and methanol tolerant capability of the two N-doped carbon catalysts are systematically evaluated, and the underneath reasons of the outperformance of rod-like catalysts over the flaky are revealed. At last, the produced carbonaceous catalysts are also used as cathodes in the single cell H2/O2 anion exchange membrane fuel cell (AEMFC), in which the rod-like FU delivers a peak power density as high as 703 mW cm-2 (vs. 1106 mW cm-2 with a Pt/C benchmark cathode catalyst).

  6. 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.

  7. Recovery mechanisms in proton exchange membrane fuel cells after accelerated stress tests

    Science.gov (United States)

    Zhang, Xu; Guo, Liejin; Liu, Hongtan

    2015-11-01

    The mechanisms of performance recovery after accelerated stress test (AST) in proton exchange membrane fuel cells (PEMFCs) are systematically studied. Experiments are carried out by incorporating a well-designed performance recovery procedure right after the AST protocol. The experiment results show that the cell performance recovers significantly from the degraded state after the AST procedure. The results from cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements further show that the performance recovery can be divided into kinetic and mass transport recoveries. It is further determined that the kinetic recovery, i.e. the recovery of electrochemical active area (ECA), is due to two distinct mechanisms: the reduction of platinum oxide and the re-attachment of detached platinum nanoparticles onto the carbon surface. The mass transport resistance is probably due to reduction of hydrophilic oxide groups on the carbon surface and the microstructure change that alleviates flooding. Performance comparisons show that the recovery procedure is highly effective, indicating the results of AST significantly over-estimate the true degradation in a PEM fuel cell. Therefore, a recovery procedure is highly recommended when an AST protocol is used to evaluate cell degradations to avoid over-estimating true performance degradations in PEMFCs.

  8. 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...

  9. Three-dimensional multiphase flow computational fluid dynamics models for proton exchange membrane fuel cell: A theoretical development

    Directory of Open Access Journals (Sweden)

    Jean-Paul Kone

    2017-03-01

    Full Text Available A review of published three-dimensional, computational fluid dynamics models for proton exchange membrane fuel cells that accounts for multiphase flow is presented. The models can be categorized as models for transport phenomena, geometry or operating condition effects, and thermal effects. The influences of heat and water management on the fuel cell performance have been repeatedly addressed, and these still remain two central issues in proton exchange membrane fuel cell technology. The strengths and weaknesses of the models, the modelling assumptions, and the model validation are discussed. The salient numerical features of the models are examined, and an overview of the most commonly used computational fluid dynamic codes for the numerical modelling of proton exchange membrane fuel cells is given. Comprehensive three-dimensional multiphase flow computational fluid dynamic models accounting for the major transport phenomena inside a complete cell have been developed. However, it has been noted that more research is required to develop models that include among other things, the detailed composition and structure of the catalyst layers, the effects of water droplets movement in the gas flow channels, the consideration of phase change in both the anode and the cathode sides of the fuel cell, and dissolved water transport.

  10. Develpment of Higher Temperature Membrane and Electrode Assembly (MEA) for Proton Exchange Membrane Fuel Cell Devices

    Energy Technology Data Exchange (ETDEWEB)

    Susan Agro, Anthony DeCarmine, Shari Williams

    2005-12-30

    Our work will fucus on developing higher temperature MEAs based on SPEKK polymer blends. Thse MEAs will be designed to operatre at 120 degrees C Higher temperatures, up to 200 degrees C will also be explored. This project will develop Nafion-free MEAs using only SPEKK blends in both membrane and catalytic layers.

  11. 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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. 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 The properties of alkali doped poly(2,5-benzimidazole) membrane with different alkali doping level for fuel cell application is reported in this work. The alkali doping level played an important role for the ion conductivity of the membrane. The ion...

  13. A hydrogen-oxygen fuel cell using an ion-exchange membrane as an electrolyte

    NARCIS (Netherlands)

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

    1966-01-01

    Using an acidic type of water leached ion exchange membrane, cell current outputs of the order of 100 mA▪cm-2 at 0,6 V cell voltage have been obtained; the removal of produced water largely limits the cell performance. Cells using the alkaline type of membrane exhibit much smaller current densities,

  14. Cross-linked PEEK-WC proton exchange membrane for fuel cell

    CSIR Research Space (South Africa)

    Lou, H

    2009-10-01

    Full Text Available The low cost proton exchange membrane was prepared by cross-linking water soluble sulfonated-sulfinated poly(oxa-p-phenylene-3,3-phthalido-p-phenylene-oxa-p-phenylene-oxyphenylene) (SsPEEK-WC). The prepared cross-linked membrane became insoluble...

  15. 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.

  16. 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.

  17. 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.

  18. Hydrocarbon and partially fluorinated sulfonated copolymer blends as functional membranes for proton exchange membrane fuel cells

    Science.gov (United States)

    Arnett, Natalie Y.; Harrison, William L.; Badami, Anand S.; Roy, Abhishek; Lane, Ozma; Cromer, Frank; Dong, Limin; McGrath, James E.

    Polymer blending is recognized as a valuable technique used to modify and improve the mechanical, thermal, and surface properties of two different polymers or copolymers. This paper investigated the solution properties and membrane properties of a biphenol-based disulfonated poly (arylene ether sulfone) random copolymer (BPS-35) with hexafluoroisopropylidene bisphenol based sulfonated poly (arylene ether sulfone) copolymers (6FSH) and an unsulfonated biphenol-based poly (arylene ether sulfone)s. The development of blended membranes with desirable surface characteristics, reduced water swelling and similar proton conductivity is presented. Polymer blends were prepared both in the sodium salt and acid forms from dimethylacetamide (DMAc). Water uptake, specific conductivity, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and contact angles were used to characterize the blended films. Surface enrichment of the fluorinated component is illustrated by an significant increase in the water-surface contact angle was observed when 10 wt.% 6FBPA-00 (106°) was added to BPS 35 (80°). Water weight gain was reduced by a factor of 2.

  19. On active disturbance rejection in temperature regulation of the proton exchange membrane fuel cells

    Science.gov (United States)

    Li, Dazi; Li, Chong; Gao, Zhiqiang; Jin, Qibing

    2015-06-01

    Operating a Proton Exchange Membrane fuel cell (PEMFC) system to maintain the stack temperature stable is one of the key issues in PEMFC's normal electrochemical reaction process. Its temperature characteristic is easily affected by inlet gas humidity, external disturbances, and electrical load changes and so on. Because of the complexity and nonlinearity of the reaction process, it is hard to build a model totally consistent with the real characteristic of the process. If model uncertainty, external disturbances, parameters changes can be regarded as "total disturbance", which is then estimated and compensated, the accurate model is no longer required and the control design can be greatly simplified to meet the practical needs. Based on this idea, an active disturbance rejection control (ADRC) with a switching law is proposed for the problem of precise temperature regulation in PEMFC. Results of the work show that the proposed control system allows the PEMFC to operate successfully at the temperature of 343 K point in the presence of two different disturbances.

  20. Electrochemical stability of carbon nanofibers in proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Garbine [Energy Department, CIDETEC-IK4, Po Miramon, 196, 20009 San Sebastian (Spain); Alcaide, Francisco, E-mail: falcaide@cidetec.es [Energy Department, CIDETEC-IK4, Po Miramon, 196, 20009 San Sebastian (Spain); Miguel, Oscar [Energy Department, CIDETEC-IK4, Po Miramon, 196, 20009 San Sebastian (Spain); Cabot, Pere L. [Laboratori d' Electroquimica de Materials i del Medi Ambient, Dept. Quimica Fisica, Universitat de Barcelona, Marti i Franques, 1-11, 08028 Barcelona (Spain); Martinez-Huerta, M.V.; Fierro, J.L.G. [Instituto de Catalisis y Petroleoquimica (CSIC), Marie Curie 2, Cantoblanco, 28049 Madrid (Spain)

    2011-10-30

    This fundamental study deals with the electrochemical stability of several non-conventional carbon based catalyst supports, intended for low temperature proton exchange membrane fuel cell (PEMFC) cathodes. Electrochemical surface oxidation of raw and functionalized carbon nanofibers, and carbon black for comparison, was studied following a potential step treatment at 25.0 deg. C in acid electrolyte, which mimics the operating conditions of low temperature PEMFCs. Surface oxidation was characterized using cyclic voltammetry, X-ray photoelectron spectroscopy (XPS), and contact angle measurements. Cyclic voltammograms clearly showed the presence of the hydroquinone/quinone couple. Furthermore, identification of carbonyl, ether, hydroxyl and carboxyl surface functional groups were made by deconvolution of the XPS spectra. The relative increase in surface oxides on carbon nanofibers during the electrochemical oxidation treatment is significantly smaller than that on carbon black. This suggests that carbon nanofibers are more resistant to the electrochemical corrosion than carbon black under the experimental conditions used in this work. This behaviour could be attributed to the differences found in the microstructure of both kinds of carbons. According to these results, carbon nanofibers possess a high potential as catalyst support to increase the durability of catalysts used in low temperature PEMFC applications.

  1. Control of proton exchange membrane fuel cell system breathing based on maximum net power control strategy

    Science.gov (United States)

    Li, Qi; Chen, Weirong; Liu, Zhixiang; Guo, Ai; Liu, Shukui

    2013-11-01

    In order to achieve the maximum net power, the analysis for the maximum net power characterization of a proton exchange membrane fuel cell (PEMFC) system is carried out. A maximum net power control (MNPC) strategy based on an implicit generalized predictive control (IGPC) and a reference governor is proposed to keep optimal oxygen excess ratio (OER) trajectory. The IGPC based on an effective informed adaptive particle swarm optimization (EIA-PSO) algorithm is developed to solve the predictive control law and reduce the computational complexity in the rolling optimization process. The simulations of three conditional tests are implemented and the results demonstrate that the proposed strategy can track the optimal OER trajectory, reduce the parasitic power and maximize the output net power. The comprehensive comparisons based on three conditional tests verify that the MNPC-IGPC has better robust performance in the presence of large disturbances, time delay and various noises. The experimental comparison with internal control system of Ballard 1.2 kW Nexa Power Module testifies the validity of the MNPC-IGPC for increasing the net power. Hence, this proposed strategy can provide better behavior to guarantee optimal OER trajectory and the maximum net power even though the disturbances and uncertainties occur.

  2. Proton Exchange Membrane Fuel Cell With Enhanced Durability Using Fluorinated Carbon As Electrocatalyst

    Directory of Open Access Journals (Sweden)

    Ahmad Yasser

    2017-01-01

    Full Text Available This study evaluates the fluorination of a carbon aerogel and its effects on the durability of the resulting electrocatalyst for Proton Exchange Membrane Fuel Cell (PEMFC. Fluorine has been introduced before or after platinum deposition. The different electrocatalysts are physico-chemically and electrochemically characterized, and the results discussed by comparison with commercial Pt/XC72 from E-Tek. The results demonstrate that the level of fluorination of the carbon aerogel can be controlled. The fluorination modifies the texture of the carbons by increasing the pore size and decreasing the specific surface area, but the textures remain appropriate for PEMFC applications. Two fluorination sites are observed, leading to both high covalent C-F bond and weakened ones, the quantity of which depends on whether the treatment is done before or after platinum deposition. The order of the different treatments is very important. The presence of platinum contributes to the fluorination mechanism, but leads to amorphous platinum rather inactive towards the Oxygen Reduction Reaction. Finally, a better durability was demonstrated for the fluorinated then platinized catalyst compared both to the same but not fluorinated catalyst and to the reference commercial material (based on the loss of the electrochemical real surface area after accelerated stress tests.

  3. Chitosan/silica coated carbon nanotubes composite proton exchange membranes for fuel cell applications.

    Science.gov (United States)

    Liu, Hai; Gong, Chunli; Wang, Jie; Liu, Xiaoyan; Liu, Huanli; Cheng, Fan; Wang, Guangjin; Zheng, Genwen; Qin, Caiqin; Wen, Sheng

    2016-01-20

    Silica-coated carbon nanotubes (SCNTs), which were obtained by a simple sol-gel method, were utilized in preparation of chitosan/SCNTs (CS/SCNTs) composite membranes. The thermal and oxidative stability, morphology, mechanical properties, water uptake and proton conductivity of CS/SCNTs composite membranes were investigated. The insulated and hydrophilic silica layer coated on CNTs eliminates the risk of electronic short-circuiting and enhances the interaction between SCNTs and chitosan to ensure the homogenous dispersion of SCNTs, although the water uptake of CS/SCNTs membranes is reduced owing to the decrease of the effective number of the amino functional groups of chitosan. The CS/SCNTs composite membranes are superior to the pure CS membrane in thermal and oxidative stability, mechanical properties and proton conductivity. The results of this study suggest that CS/SCNTs composite membranes exhibit promising potential for practical application in proton exchange membranes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Water and proton transport properties of hexafluorinated sulfonated poly(arylenethioethersulfone) copolymers for applications to proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Khalfan, Amish N.; Sanchez, Luz M.; Kodiweera, Chandana; Greenbaum, Steve G. [Hunter College of the City University of New York, Physics Department, 695 Park Avenue, New York, NY 10021 (United States); Bai, Zongwu [University of Dayton Research Institute, University of Dayton, 300 College Park Drive, Dayton, OH 45469 (United States); Dang, Thuy D. [Air Force Research Laboratory/MLBP, Material and Manufacturing Directorate, Wright-Patterson Air Force Base, OH 45433 (United States)

    2007-11-15

    In the present study, we examine the water and proton transport properties of hexafluorinated sulfonated poly(arylenethioethersulfone) (6F-SPTES) copolymer membranes for applications to proton exchange membrane fuel cells (PEMFCs). The 6F-SPTES copolymer membranes build upon the structures of previously studied sulfonated poly(arylenethioethersulfone) (SPTES) copolymer membranes to include CF{sub 3} functional groups in efforts to strengthen water retention and extend membrane performance at elevated temperatures (above 120 C). The 6F-SPTES copolymer membranes sustain higher water self-diffusion and greater proton conductivities than the commercial Nafion {sup registered} membrane. Water diffusion studies of the 6F-SPTES copolymer membranes using the pulsed-field gradient spin-echo NMR technique reveal, however, the fluorinated membranes to be somewhat unfavorable over their non-fluorinated counterparts as high temperature membranes. In addition, proton conductivity measurements of the fluorinated membranes up to 85 C show comparable results with the non-fluorinated SPTES membranes. (author)

  5. Employing Hot Wire Anemometry to Directly Measure the Water Balance of a Commercial Proton Exchange Membrane Fuel Cell Stack

    DEFF Research Database (Denmark)

    Shakhshir, Saher Al; Berning, Torsten

    2016-01-01

    and increased degradation rates. Clearly, a fundamental understanding of all aspects of water management in PEMFC is imperative. This includes the fuel cell water balance, i.e. which fraction of the product water leaves the fuel cell via the anode channels versus the cathode channel. Our research group...... is currently developing a novel technique to obtain an ad-hoc and real time electrical signal of the fuel cell water balance by employing hot wire anemometry. In this work, the hot wire sensor is placed in the anode outlet of a commercial air-cooled fuel cell stack by Ballard Power Systems, and the voltage......Proton exchange membrane fuel cells (PEMFC’s) are currently being commercialized for various applications ranging from automotive (e.g. the Toyota Mirai) to stationary such as powering telecom backup units. In PEMFC’s, oxygen from air is internally combined with hydrogen to form water and produce...

  6. Polypyrrole layered SPEES/TPA proton exchange membrane for direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Neelakandan, S.; Kanagaraj, P. [PG & Research Department of Chemistry, Polymeric Materials Research Lab, Alagappa Government Arts College, Karaikudi 630003 (India); Sabarathinam, R.M. [Functional Material Division, Central Electrochemical Research Institute, Karaikudi 630006 (India); Nagendran, A., E-mail: nagimmm@yahoo.com [PG & Research Department of Chemistry, Polymeric Materials Research Lab, Alagappa Government Arts College, Karaikudi 630003 (India)

    2015-12-30

    Graphical abstract: - Highlights: • A series of Ppy layered SPEES/TPA composite membranes were prepared. • SPEES/TPA-Ppy hybrid membranes displayed efficient methanol resistance than Nafion 117. • SPEES/TPA-Ppy4 membrane exhibits highest relative selectivity of 2.86 × 104 S cm{sup 3} s. • Increasing Ppy layer on membrane surface reduces the leaching out of tungstophosphoric acid. - Abstract: Hybrid membranes based on sulfonated poly(1,4-phenylene ether ether sulfone) (SPEES)/tungstophosphoric acid (TPA) were prepared. SPEES/TPA membrane surfaces were modified with polypyrrole (Ppy) by in situ polymerization method to reduce the TPA leaching. The morphology and electrochemical property of the surface coated membranes were studied by SEM, AFM, water uptake, ion exchange capacity, proton conductivity, methanol permeability and tensile strength. The water uptake and the swelling ratio of the surface coated membranes decreased with increasing the Ppy layer. The surface roughness of the hybrid membrane was decreased with an increase in Ppy layer on the membrane surface. The methanol permeability of SPEES/TPA-Ppy4 hybrid membrane was significantly suppressed and found to be 2.1 × 10{sup −7} cm{sup 2} s{sup −1}, which is 1.9 times lower than pristine SPEES membrane. The SPEES/TPA-Ppy4 membrane exhibits highest relative selectivity (2.86 × 10{sup 4} S cm{sup −3} s) than the other membrane with low TPA leaching. The tensile strength of hybrid membranes was improved with the introduction of Ppy layer. Combining their lower swelling ratio, high thermal stability and selectivity, SPEES/TPA-Ppy4 membranes could be a promising material as PEM for DMFC applications.

  7. Improving the Performance Of Single Cells In The Design Of Proton Exchange Membrane Fuel Cell (PEMFC) When Using Hydrogen

    OpenAIRE

    - Mulyazmi; Maria Ulfah; Silvi Octavia

    2017-01-01

    A proton Exchange Membrane Fuel Cell (PEMFC) was developed as a potential solution in power supply applications. In this study, the parameter values such as the relative humidity, the temperature, the pressure, the stoichiometric ratio of hydrogen to oxygen and the mass of catalyst used were varied to determine their effects on the single cell performance of PEMFC. The investigation showed that an increase in the temperature from 353 to 363 K resulted in a modest improvement in the single-cel...

  8. Proton-Exchange-Membrane Fuel Cell Powerplants Developed and Tested for Exploration Missions

    Science.gov (United States)

    Hoberecht, Mark A.; Pham, Nang T.

    2005-01-01

    Proton-exchange-membrane fuel cell (PEMFC) technology has received major attention for terrestrial applications, such as the automotive and residential markets, for the past 20 years. This attention has significantly advanced the maturity of the technology, resulting in ever more compact, efficient, reliable, and inexpensive PEMFC designs. In comparison to the terrestrial operating environment, the space operating environment is much more demanding. Microgravity to high-gravity loads and the need to use pure oxygen (rather than air) as the fuel cell oxidizer place more stringent demands on PEMFC technology. NASA and its partners from industry are leveraging terrestrial PEMFC advancements by conducting parallel space technology development for future exploration missions. A team from the NASA Glenn Research Center, NASA Johnson Space Center, and NASA Kennedy Space Center recently completed the first phase of a PEMFC powerplant development effort for exploration missions. The industry partners for this phase of the development effort were ElectroChem, Inc., and Teledyne Energy Systems, Inc. Under contract to Glenn, both of these industry partners successfully designed, fabricated, and tested a breadboard PEMFC powerplant in the 1- to 5-kW power range. These powerplants were based on existing company-proprietary fuel cell stack designs, combined with off-the-shelf components, which formed the balance of the powerplant design. Subsequent to the contractor development efforts, both powerplants were independently tested at Johnson to verify operational and performance characteristics, and to determine suitability for further technology development in the second phase of the NASA-led effort. Following the independent NASA testing, Teledyne Energy Systems, Inc., was selected to develop an engineering model PEMFC powerplant. This effort was initiated by the 2nd Generation Reusable Launch Vehicle (RLV) Program Office in 2001; it transitioned to the Next Generation Launch

  9. The first anion-exchange membrane fuel cell to exceed 1 W cm-2 at 70 °C with a non-Pt-group (O2) cathode.

    Science.gov (United States)

    Wang, Lianqin; Brink, Jethro J; Varcoe, John R

    2017-08-22

    Anion-exchange membrane fuel cells face two challenges: performance and durability. Addressing the first, we demonstrate high performance with both O2 and CO2-free air supplies, even when using a Ag/C cathode. This was enabled by the development of a radiation-grafted anion-exchange membrane that was less than 30 μm thick when hydrated.

  10. Proton exchange membrane fuel cells for space and electric vehicle applications: From basic research to technology development

    Science.gov (United States)

    Srinivasan, Supramaniam; Mukerjee, Sanjeev; Parthasarathy, A.; CesarFerreira, A.; Wakizoe, Masanobu; Rho, Yong Woo; Kim, Junbom; Mosdale, Renaut A.; Paetzold, Ronald F.; Lee, James

    1994-01-01

    The proton exchange membrane fuel cell (PEMFC) is one of the most promising electrochemical power sources for space and electric vehicle applications. The wide spectrum of R&D activities on PEMFC's, carried out in our Center from 1988 to date, is as follows (1) Electrode Kinetic and Electrocatalysis of Oxygen Reduction; (2) Optimization of Structures of Electrodes and of Membrane and Electrode Assemblies; (3) Selection and Evaluation of Advanced Proton Conducting Membranes and of Operating Conditions to Attain High Energy Efficiency; (4) Modeling Analysis of Fuel Cell Performance and of Thermal and Water Management; and (5) Engineering Design and Development of Multicell Stacks. The accomplishments on these tasks may be summarized as follows: (1) A microelectrode technique was developed to determine the electrode kinetic parameters for the fuel cell reactions and mass transport parameters for the H2 and O2 reactants in the proton conducting membrane. (2) High energy efficiencies and high power densities were demonstrated in PEMFCs with low platinum loading electrodes (0.4 mg/cm(exp 2) or less), advanced membranes and optimized structures of membrane and electrode assemblies, as well as operating conditions. (3) The modeling analyses revealed methods to minimize mass transport limitations, particularly with air as the cathodic reactant; and for efficient thermal and water management. (4) Work is in progress to develop multi-kilowatt stacks with the electrodes containing low platinum loadings.

  11. Proton exchange membrane fuel cell degradation: A parametric analysis using Computational Fluid Dynamics

    Science.gov (United States)

    Ozden, Ender; Tari, Ilker

    2016-02-01

    A Polymer Electrolyte Membrane (PEM) fuel cell is numerically investigated both as fresh and as degraded with the help of observed degradation patterns reported in the literature. The fresh fuel cell model is validated and verified with the data from the literature. Modifying the model by varying the parameters affected by degradation, a degraded PEM fuel cell model is created. The degraded fuel cell is parametrically analyzed by using a commercial Computational Fluid Dynamics (CFD) software. The investigated parameters are the membrane equivalent weight, the Catalyst Layer (CL) porosity and viscous resistance, the Gas Diffusion Layer (GDL) porosity and viscous resistance, and the bipolar plate contact resistance. It is shown for the first time that PEM fuel cell overall degradation can be numerically estimated by combining experimental data from degraded individual components. By comparing the simulation results for the fresh and the degraded PEM fuel cells for two years of operation, it is concluded that the effects of overall degradation on cell potential is significant - estimated to be 17% around the operating point of the fuel cell at 0.95 V open circuit voltage and 70 °C operating temperature.

  12. Photoregenerative I−/I3− couple as a liquid cathode for proton exchange membrane fuel cell

    Science.gov (United States)

    Liu, Zhen; Wang, Yadong; Ai, Xinping; Tu, Wenmao; Pan, Mu

    2014-01-01

    A photoassisted oxygen reduction reaction (ORR) through I−/I3− redox couple was investigated for proton exchange membrane (PEM) fuel cell cathode reaction. The I−/I3−-based liquid cathode was used to replace conventional oxygen cathode, and its discharge product I− was regenerated to I3− by photocatalytic oxidation with the participation of oxygen. This new and innovative approach may provide a strategy to eliminate the usage of challenging ORR electrocatalysts, resulting in an avenue for developing low-cost and high-efficiency PEM fuel cells. PMID:25348812

  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. Characterization of an anionic-exchange membranes for direct methanol alkaline fuel cells

    CSIR Research Space (South Africa)

    Abuin, GC

    2010-06-01

    Full Text Available modulus were evaluated and compared to Nafion 117, commonly employed in direct methanol fuel cells. The anionic polysulfone membrane sorbs more water than Nafion all over the whole range of water activities, but it uptakes much less methanol as compared...

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

    CSIR Research Space (South Africa)

    Nonjola, S

    2010-09-01

    Full Text Available 's modulus were evaluated and compared to Nafion 117, commonly employed in direct methanol fuel cells. The anionic polysulfone membrane sorbs more water than Nafion all over the whole range of water activities, but it uptakes much less methanol as compared...

  16. Novel proton exchange membrane based on crosslinked poly(vinyl alcohol) for direct methanol fuel cells

    Science.gov (United States)

    Liu, Chien-Pan; Dai, Chi-An; Chao, Chi-Yang; Chang, Shoou-Jinn

    2014-03-01

    In this study, we report the synthesis and the characterization of poly (vinyl alcohol) based proton conducting membranes. In particular, we describe a novel physically and chemically PVA/HFA (poly (vinyl alcohol)/hexafluoroglutaric acid) blending membranes with BASANa (Benzenesulfonic acid sodium salt) and GA (Glutaraldehyde) as binary reaction agents. The key PEM parameters such as ion exchange capacity (IEC), water uptake, proton conductivity, and methanol permeability were controlled by adjusting the chemical composition of the membranes. The IEC value of the membrane is found to be an important parameter in affecting water uptake, conductivity as well as the permeability of the resulting membrane. Plots of the water uptake, conductivity, and methanol permeability vs. IEC of the membranes show a distinct change in the slope of their curves at roughly the same IEC value which suggests a transition of structural changes in the network. The proton conductivities and the methanol permeability of all the membranes are in the range of 10-3-10-2 S cm-1 and 10-8-10-7 cm2 s-1, respectively, depending on its binary crosslinking density, and it shows great selectivity compared with those of Nafion®-117. The membranes display good mechanical properties which suggest a good lifetime usage of the membranes applied in DMFCs.

  17. 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.

  18. 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...... operation. The water balance indicates how much of the product water leaves at the anode side versus the cathode side. Previous methods of determining the fuel cell water balance often relied on condensing the water in the exhaust gas streams and weighing the accumulated mass which is a time consuming...... process that has limited accuracy. Currently, our group is developing a novel method to accurately determine the water balance in a PEMFC in real time by employing hot-wire anemometry. The amount of heat transferred from the wire to the anode exhaust stream can be translated into a voltage signal which...

  19. Applying hot-wire anemometry to directly measure the water balance in a proton exchange membrane fuel cell

    DEFF Research Database (Denmark)

    Al Shakhshir, Saher; Andreasen, Søren Juhl; Berning, Torsten

    2016-01-01

    In order to better understand and more accurately measure the water balance in a proton exchange membrane fuel cell, our group has recently proposed to apply hot wire anemometry in the fuel cell's anode outlet. It was theoretically shown that the electrical signal obtained from the hot wire sensor...... can be directly converted into the fuel cell water balance. In this work an ex-situ experimental investigation is performed to examine the effect of the wire diameter and the outlet pipe diameter on the voltage signal. For a laboratory fuel cell where the mass flow rate the anode outlet is small......, it is found important to use a small output pipe diameter to obtain a sufficiently strong convection effect and hence clear voltage readings. Depending on the hot wire diameter and the inner pipe diameter, the resulting values for the exponent of the Reynolds number Re in the determination of the Nusselt...

  20. Study of operating conditions and cell design on the performance of alkaline anion exchange membrane based direct methanol fuel cells

    Science.gov (United States)

    Prakash, G. K. Surya; Krause, Frederick C.; Viva, Federico A.; Narayanan, S. R.; Olah, George A.

    2011-10-01

    Direct methanol fuel cells using an alkaline anion exchange membrane (AAEM) were prepared, studied, and optimized. The effects of fuel composition and electrode materials were investigated. Membrane electrode assemblies fabricated with Tokuyama® AAEM and commercial noble metal catalysts achieved peak power densities between 25 and 168 mW cm-2 depending on the operating temperature, fuel composition, and electrode materials used. Good electrode wettability at the anode was found to be very important for achieving high power densities. The performance of the best AAEM cells was comparable to Nafion®-based cells under similar conditions. Factors limiting the performance of AAEM MEAs were found to be different from those of Nafion® MEAs. Improved electrode kinetics for methanol oxidation in alkaline electrolyte at Pt-Ru are apparent at low current densities. At high current densities, rapid CO2 production converts the hydroxide anions, necessary for methanol oxidation, to bicarbonate and carbonate: consequently, the membrane and interfacial conductivity are drastically reduced. These phenomena necessitate the use of aqueous potassium hydroxide and wettable electrode materials for efficient hydroxide supply to the anode. However, aqueous hydroxide is not needed at the cathode. Compared to AAEM-based fuel cells, methanol fuel cells based on proton-conducting Nafion® retain better performance at high current densities by providing the benefit of carbon dioxide rejection.

  1. In situ measurements of water transfer due to different mechanisms in a proton exchange membrane fuel cell

    Science.gov (United States)

    Husar, Attila; Higier, Andrew; Liu, Hongtan

    Water management is of critical importance in a proton exchange membrane (PEM) fuel cell, in particular, those based on a sulfonic acid polymer, which requires water to conduct protons. Yet there are limited in situ studies of water transfer through the membrane and no data are available for water transfer due to individual mechanisms through the membrane in an operational fuel cell. Thus it is the objective of this study to measure water transfer through the membrane due to each individual mechanism in an operational PEM fuel cell. The three different mechanisms of water transfer, i.e., electro-osmotic drag, diffusion and hydraulic permeation are isolated by specially imposed boundary conditions. Therefore water transfer through the membrane due to each mechanism is measured separately. In this study, all the data is collected in an actual assembled operational fuel cell. The experimental results show that water transfer due to hydraulic permeation, i.e. the pressure difference between the anode and cathode is at least an order of magnitude lower than those due to the other two mechanisms. The data for water transfer due to diffusion through the membrane are in good agreement with some of the ex situ data in the literature. The data for electro-osmosis show that the number of water molecules dragged per proton increases not only with temperature but also with current density, which is different from existing data in the literature. The methodology used in this study is simple and can be easily adopted for in situ water transfer measurement due to different mechanisms in other PEM fuel cells without any cell modifications.

  2. Surface-fluorinated proton-exchange membrane with high electrochemical durability for direct methanol fuel cells.

    Science.gov (United States)

    Lee, Chang Hyun; Lee, So Young; Lee, Young Moo; Lee, Sang Yun; Rhim, Ji Won; Lane, Ozma; McGrath, James E

    2009-05-01

    Random disulfonated poly(arylene ether sulfone)-silica nanocomposite (FSPAES-SiO2) membranes were physicochemically tuned via surface fluorination. Surface fluorination for 30 min converted about 20% of the C-H bonds on the membrane surface into C-F bonds showing hydrophobicity and electronegativity at the same time. The membranes with hydrophobic surface properties showed high dimensional stability and low methanol permeability when hydrated for direct methanol fuel cell applications. In particular, the surface enrichment of fluorine atoms led to anisotropic swelling behavior, associated with a stable electrode interface formation. Interestingly, in spite of the use of a random copolymer as a polymer matrix, the low surface free energy of the C-F bonds induced a well-defined continuous ionic channel structure, similar to those of multiblock copolymers. In addition to the morphological transition, fluorine atoms with high electron-withdrawing capability promoted the dissociation of sulfonic acid (-SO3H) groups. Consequently, FSPAES-SiO2 membranes exhibited improved proton conductivity. Thus, FSPAES-SiO2 membranes exhibited significantly improved single-cell performances (about 200%) at a constant voltage of 0.4 V in comparison with those of Nafion 117 and nonfluorinated membranes. Surprisingly, their good electrochemical performances were maintained with very low nonrecovery loss over the time period of 1400 h and interfacial resistances 380% times lower than those of conventional membrane-electrode assemblies comprising the control hydrocarbon membrane and a Nafion binder for the electrodes.

  3. 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

    dispersion of modified laponite clay was achieved in polybenzimidazole (PBI) solutions which, when cast and allowed to dry, resulted in homogeneous and transparent composite membranes containing up to 20 wt% clay in the polymer. The clay was organically modified using a series of ammonium......, 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...... level of 12 mol H3PO4 per monomer unit, proton conductivity as high as 0.12 S cm−1 was obtained at 150 °C and 12% relative humidity. The composite membranes exhibited hydrogen permeability ranging from 0.6 to 1.2 × 10−10 mol cm−1 s−1 bar−1 from 100 to 200 °C, which was five times lower than that of acid...

  4. Fabrication BaZrO3/PBI-based nanocomposite as a new proton conducting membrane for high temperature proton exchange membrane fuel cells

    Science.gov (United States)

    Hooshyari, Khadijeh; Javanbakht, Mehran; Shabanikia, Akbar; Enhessari, Morteza

    2015-02-01

    Novel PBI (polybenzimidazole)-BaZrO3 (PBZ) nanocomposite membranes have been prepared for the high temperature proton exchange membrane (HT-PEM) fuel cells. The results showed that the water uptake, acid doping level and proton conductivity of the PBZ nanocomposite membranes were higher than that of virgin PBI membrane due to the presence of perovskite structure BaZrO3 nanoparticles, which as protonic conductor can perform as a special pathway for hydrogen transport. The proton conductivity of the PBZ nanocomposite membranes with 13 mol phosphoric acid per PBI repeat unit was obtained 125 mS/cm at 180 °C and 5% relative humidity. It was found that the performance of the fuel cells increases by increasing temperature; this was explained by faster reaction kinetic and higher proton conductivity. The power density and current density at 0.5 V 180 °C with 5% relative humidity were observed 0.56 W/cm2 and 1.12 A/cm2, respectively for PBZ nanocomposite membranes containing 4 wt% of the nanofillers. The results suggested that PBZ nanocomposite membranes are promising electrolytes for HT-PEM fuel cells with improved proton conductivity.

  5. Surface modification of a proton exchange membrane and hydrogen storage in a metal hydride for fuel cells

    Science.gov (United States)

    Andrews, Lisa

    Interest in fuel cell technology is rising as a result of the need for more affordable and available fuel sources. Proton exchange membrane fuel cells involve the catalysis of a fuel to release protons and electrons. It requires the use of a polymer electrolyte membrane to transfer protons through the cell, while the electrons pass through an external circuit, producing electricity. The surface modification of the polymer, NafionRTM, commonly researched as a proton exchange membrane, may improve efficiency of a fuel cell. Surface modification can change the chemistry of the surface of a polymer while maintaining bulk properties. Plasma modification techniques such as microwave discharge of an argon and oxygen gas mixture as well as vacuum-ultraviolet (VUV) photolysis may cause favorable chemical and physical changes on the surface of Nafion for improved fuel cell function. A possible increase in hydrophilicity as a result of microwave discharge experiments may increase proton conductivity. Grafting of acrylic acid from the surface of modified Nafion may decrease the permeation of methanol in a direct methanol fuel cell, a process which can decrease efficiency. Modification of the surface of Nafion samples were carried out using: 1) An indirect Ar/O2 gas mixture plasma investigating the reaction of oxygen radicals with the surface, 2) A direct Ar/O2 gas mixture plasma investigating the reaction of oxygen radicals and VUV radiation with the surface and, 3) VUV photolysis investigating exclusively the interaction of VUV radiation with the surface and any possible oxidation upon exposure to air. Acrylic acid was grafted from the VUV photolysed Nafion samples. All treated surfaces were analyzed using X-ray photoelectron spectroscopy (XPS). Fourier transform infrared spectroscopy (FTIR) was used to analyze the grafted Nafion samples. Scanning electron microscopy (SEM) and contact angle measurements were used to analyze experiments 2 and 3. Using hydrogen as fuel is a

  6. Studies on PVA based nanocomposite Proton Exchange Membrane for Direct methanol fuel cell (DMFC) applications

    Science.gov (United States)

    Bahavan Palani, P.; Kannan, R.; Rajashabala, S.; Rajendran, S.; Velraj, G.

    2015-02-01

    Different concentrations of Poly (vinyl alcohol)/Montmorillonite (PVA/MMT) based proton exchange membranes (PEMs) have been prepared by solution casting method. The structural and electrical properties of these composite membranes have been characterized by using X-ray diffraction (XRD), Fourier transform infrared spectroscopic (FTIR) and AC impedance spectroscopic methods. The conductivity of the PEMs has been estimated for the different concentration of MMT. Water/Methanol uptake measurement were also analyzed for the prepared PEMs and presented. The proton conductivity studies were carried out at room temperature with 100% of humidity.

  7. Preliminary Study of the Use of Sulphonated Polyether Ether Ketone (SPEEK as Proton Exchange Membrane for Microbial Fuel Cell (MFC

    Directory of Open Access Journals (Sweden)

    Dani Permana

    2018-02-01

    Full Text Available Sulfonated polyether ether ketone (SPEEK was utilized as a proton exchange membrane (PEM in Microbial Fuel Cell (MFC. The SPEEK performance in producing electricity had been observed in MFC using wastewater and glucose as substrates. The MFC with catering and tofu wastewater produced maximum power density about 0.31 mW/m2 and 0.03 mW/m2, respectively, lower that of MFC with tapioca average power density of 39.4 W/m2 over 48 h. The power density boosted because of the presence of Saccharomyces cerevisiae as inoculum. The study using of S. cerevisiae and Acetobacter acetii, separately, were also conducted in with glucose as substrate. The MFC produced an average power densities were 7.3 and 6.4 mW/m2 for S. cerevisiae and A. acetii, respectively. The results of this study indicated that SPEEK membrane has the potential usage in MFCs and can substitute the commercial membrane, Nafion. Article History: Received: Juni 14th 2017; Received: Sept 25th 2017; Accepted: December 16th 2017; Available online How to Cite This Article: Putra, H.E., Permana, D and Djaenudin, D. (2018 Preliminary Study of the Use of Sulfonated Polyether Ether Ketone (SPEEK as Proton Exchange Membrane for Microbial Fuel Cell (MFC. International Journal of Renewable Energy Development, 7(1, 7-12. https://doi.org/10.14710/ijred.7.1.7-12

  8. Detection of Reactive Oxygen Species in Anion Exchange Membrane Fuel Cells using In Situ Fluorescence Spectroscopy.

    Science.gov (United States)

    Zhang, Yunzhu; Parrondo, Javier; Sankarasubramanian, Shrihari; Ramani, Vijay

    2017-08-10

    The objectives of this study were: 1) to confirm superoxide anion radical (O2.- ) formation, and 2) to monitor in real time the rate of O2.- generation in an operating anion exchange membrane (AEM) fuel cell using in situ fluorescence spectroscopy. 1,3-Diphenlisobenzofuran (DPBF) was used as the fluorescent molecular probe owing to its selectivity and sensitivity toward O2.- in alkaline media. The activation energy for the in situ generation of O2.- during AEM fuel cell operation was estimated to be 18.3 kJ mol-1 . The rate of in situ generation of O2.- correlated well with the experimentally measured loss in AEM ion-exchange capacity and ionic conductivity attributable to oxidative degradation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. TiO2/bi A-SPAES(Ds 1.0) composite membranes for proton exchange membrane in direct methanol fuel cell (DMFC).

    Science.gov (United States)

    Zhang, Ni; Zhong, Chuanqing; Xie, Bing; Liu, Huiling; Wang, Xingzu

    2014-09-01

    A series of TiO2/bi A-SPAES(Ds 1.0) composite membranes with various contents of nano-sized TiO2 particles were prepared through sol-gel method. Scanning electron microscopy (SEM) images indicated the TiO2 particles were well dispersed within polymer matrix. These membranes were used for proton exchange membrane (PEM) for performance evaluation in direct methanol fuel cell (DMFC). These composite membranes showed good thermal stability and mechanical strength. It was found that the water uptake of these membranes enhanced with the TiO2 amount increasing in these composite membranes. Meanwhile, the introduction of TiO2 particles increased the proton conductivity and reduced the methanol permeability. The proton conductivities of these composite membranes with 8% TiO2 particles (0.120 S/cm and 0.128 S/cm) were higher than those of Nafion 117 membrane (0.114 S/cm and 0.117 S/cm) at 80 degrees C and 100 degrees C. Specially, the methanol diffusion coefficient (1.2 x 10(-7) cm2/s) of the composite membrane with 8% TiO2 content was much lower than that of Nafion 117 membrane (2.1 x 10(-6) cm2/s). As a result, the TiO2/bi A-SPAES composite membrane was considered as a promising material for PEM in DMFC.

  10. Development of membrane electrode assembly for high temperature proton exchange membrane fuel cell by catalyst coating membrane method

    Science.gov (United States)

    Liang, Huagen; Su, Huaneng; Pollet, Bruno G.; Pasupathi, Sivakumar

    2015-08-01

    Membrane electrode assembly (MEA), which contains cathode and anode catalytic layer, gas diffusion layers (GDL) and electrolyte membrane, is the key unit of a PEMFC. An attempt to develop MEA for ABPBI membrane based high temperature (HT) PEMFC is conducted in this work by catalyst coating membrane (CCM) method. The structure and performance of the MEA are examined by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and I-V curve. Effects of the CCM preparation method, Pt loading and binder type are investigated for the optimization of the single cell performance. Under 160 °C and atmospheric pressure, the peak power density of the MEA, with Pt loading of 0.5 mg cm-2 and 0.3 mg cm-2 for the cathode and the anode, can reach 277 mW cm-2, while a current density of 620 A cm-2 is delivered at the working voltage of 0.4 V. The MEA prepared by CCM method shows good stability operating in a short term durability test: the cell voltage maintained at ∼0.45 V without obvious drop when operated at a constant current density of 300 mA cm-2 and 160 °C under ambient pressure for 140 h.

  11. Oxygen reduction and methanol oxidation behaviour of SiC based Pt nanocatalysts for proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

    Dhiman, Rajnish; Stamatin, Serban Nicolae; Andersen, Shuang Ma

    2013-01-01

    Research with proton exchange membrane fuel cells has demonstrated their important potential as providers of clean energy. The commercialization of this type of fuel cell needs a breakthrough in electrocatalyst technology to reduce the relatively large amount of noble metal platinum used...... with the present carbon based substrates. We have recently examined suitably sized silicon carbide (SiC) particles as catalyst supports for fuel cells based on the stable chemical and mechanical properties of this material. In the present study, we have continued our work with studies of the oxygen reduction...... and methanol oxidation reactions of SiC supported catalysts and measured them against commercially available carbon based catalysts. The deconvolution of the hydrogen desorption signals in CV cycles shows a higher contribution of Pt (110) & Pt (111) peaks compared to Pt (100) for SiC based supports than...

  12. Effect of chloride impurities on the performance and durability of polybenzimidazole-based high temperature proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

    Ali, Syed Talat; Li, Qingfeng; Pan, Chao

    2011-01-01

    . The performance loss was recovered when switching from the HCl solution back to pure water in the air humidifier. Under an accelerated aging performance test conducted through potential cycling between 0.9 V and 1.2 V, the PBI-based fuel cell initially containing 0.5 NaCl mg cm−2 on the cathode catalyst layer......The effect of chloride as an air impurity and as a catalyst contaminant on the performance and durability of polybenzimidazole (PBI)-based high temperature proton exchange membrane fuel cell (HT-PEMFC) was studied. The ion chromatographic analysis reveals the existence of chloride contaminations...... temperatures in 85% phosphoric acid containing chloride ions showed both increase in oxidation and reduction current densities. The fuel cell performance, i.e. the current density at a constant voltage of 0.4 V and 0.5 V was found to be degraded as soon as HCl was introduced in the air humidifier...

  13. The production of sulfonated chitosan-sodium alginate found in brown algae (Sargassum sp.) composite membrane as proton exchange membrane fuel cell (PEMFC)

    Science.gov (United States)

    Wafiroh, Siti; Pudjiastuti, Pratiwi; Sari, Ilma Indana

    2016-03-01

    The majority of energy was used in this period is from fossil fuel, which getting decreased in the future. The objective of this research is production and characterization of sulfonated chitosan-sodium alginate found in brown algae (Sargassum sp.) composite membrane as Proton Exchange Membrane Fuel Cell (PEMFC) for alternative energy. PEMFC was produced with 4 variations (w/w) ratio between chitosan and sodium alginate, 8 : 0, 8 : 1, 8 : 2, 8 : 4 (w/w). The production of membrane was mixed sodium alginate solution into chitosan solution and sulfonated with H2SO4 0.72 N. The characterization of the PEM was uses Modulus Young analysis, water swelling, ion exchange capacity, FTIR, SEM, DTA, methanol permeability and proton conductivity. The result of the research, showed that the optimum membrane was with ratio 8 : 2 (w/w) that the Modulus Young 8564 kN/m2, water swelling 31.86%, ion exchange capacity 1.020 meq/g, proton conductivity 8,8 × 10-6 S/cm, methanol permeability 1.90 × 10-8 g/cm2s and glass transition temperature (Tg) 100.9 °C, crystalline temperature (Tc) 227.6 °C, and the melting temperature (Tm) 267.9 °C.

  14. On controllability and system constraints of the linear models of proton exchange membrane and solid oxide fuel cells

    Science.gov (United States)

    Radisavljevic, Verica

    2011-10-01

    In this paper we first show that the linear models of proton exchange membrane (polymer electrolyte membrane, PEM) and solid oxide (SO) fuel cells, commonly used in power and energy literature, are not controllable. The source of uncontrollability is the equation for pressure of the water vapor that is only affected by the fuel cell current, which in fact is a disturbance in this system and cannot be controlled by the given model inputs: inlet molar flow rates of hydrogen and oxygen. Being uncontrollable these models are not good candidates for studying control of dynamic processes in PEM and SO fuel cells. However, due to their simplicity, they can be used in hybrid configurations with other energy producing devices such as photovoltaic (solar) cells, wind turbine, micro gas turbine, battery (ultra capacitor) to demonstrate some other phenomena, but not for control purposes unless the hybrid models formed in such hybrid configurations are controllable. Testing controllability of such hybrid models is mandatory. Secondly, we introduce some algebraic constraints that follow from the model dynamics and the Nernst open-loop fuel cell voltage formula. These constraints must be satisfied in simulation of considered fuel cell modes, for example, via MATLAB/Simulink or any other computer software package.

  15. The dew point temperature as a criterion for optimizing the operating conditions of proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

    Berning, Torsten

    2012-01-01

    In this article an analytical method to calculate the dew point temperatures of the anode and cathode exit gas streams of a proton exchange membrane fuel cell is developed. The results of these calculations are used to create diagrams that show the dew point temperatures as function...... of the operating pressure, the stoichiometric flow ratios and the net drag coefficient of water through the membrane. Then, computational modeling results obtained with a previously published model are analyzed and compared with the dew point charts, and it is demonstrated how cell flooding or membrane dry-out can...... be predicted a priori with the aid of these diagrams. Finally, guidelines for the desired cell operating temperature based on the expected dew point temperatures are developed. In the current work these guidelines are limited to the interdigitated flow field design, and they are likely to be different...

  16. Recyclable cross-linked anion exchange membrane for alkaline fuel cell application

    Science.gov (United States)

    Hou, Jianqiu; Liu, Yazhi; Ge, Qianqian; Yang, Zhengjin; Wu, Liang; Xu, Tongwen

    2018-01-01

    Cross-linking can effectively solve the conductivity-swelling dilemma in anion exchange membranes (AEMs) but will generate solid wastes. To address this, we developed an AEM cross-linked via disulfide bonds, bearing quaternary ammonium groups, which can be easily recycled. The membrane (RC-QPPO) with IEC of 1.78 mmol g-1, when cross-linked, showed enhanced mechanical properties and good hydroxide conductivity (24.6 mS cm-1 at 30 °C). Even at higher IEC value (2.13 mmol g-1), it still has low water uptake, low swelling ratio and delivers a peak power density of 150 mW cm-2 at 65 °C. Exploiting the formation of disulfide bonds from -SH groups, the membrane can be readily cross-linked in alkaline condition and recycled by reversibly breaking disulfide bonds with dithiothreitol (DTT). The recycled membrane solution can be directly utilized to cast a brand-new AEM. By washing away the residual DTT with water and exposure to air, it can be cross-linked again and this process is repeatable. During the recycling and cross-linking processes, the membrane showed a slight IEC decrease of 5% due to functional group degradation. The strategy presented here is promising in enhancing AEM properties and reducing the impact of artificial polymers on the environment.

  17. Evaluation of Cathode Gas Composition and Temperature Influences on Alkaline Anion Exchange Membrane Fuel Cell (AAEMFC Performance

    Directory of Open Access Journals (Sweden)

    Topal Leyla

    2014-02-01

    Full Text Available The effects of different temperatures (55, 65, 75 and 85 °C and cathode gas compositions (O2, synthetic air, air and 90% synthetic air+10% CO2 on alkaline anion exchange membrane fuel cell (AAEMFC were evaluated. Membrane electrode assemblies (MEA were fabricated using commercial anion exchange membrane (AEM in OH- form and Pt catalyst. Polarization curves and voltage responses during constant current were performed in order to describe the influences of temperature and gas composition on the AAEMFC performance. The experimental results showed that the fuel cell performance increases with elevating temperatures for all applied gas compositions. Highest power density of 34.7 mW cm-2 was achieved for pure O2 as cathode feed. A decrease to 20.3 mW cm-2 was observed when cathode gas composition was changed to synthetic air due to reduction of the O2 partial pressure. The presence of CO2 in atmospheric air applied to the cathode stream caused a further drop of the maximum power density to 15.2 mW cm-2 driven by neutralization of OH- ions with CO2.

  18. The critical relation between chemical stability of cations and water in anion exchange membrane fuel cells environment

    Science.gov (United States)

    Dekel, Dario R.; Willdorf, Sapir; Ash, Uri; Amar, Michal; Pusara, Srdjan; Dhara, Shubhendu; Srebnik, Simcha; Diesendruck, Charles E.

    2018-01-01

    Anion exchange membrane fuel cells can potentially revolutionize energy storage and delivery; however, their commercial development is hampered by a significant technological impedance: the chemical decomposition of the anion exchange membranes during operation. The hydroxide anions, while transported from the cathode to the anode, attack the positively charged functional groups in the polymer membrane, neutralizing it and suppressing its anion-conducting capability. In recent years, several new quaternary ammonium salts have been proposed to address this challenge, but while they perform well in ex-situ chemical studies, their performance is very limited in real fuel cell studies. Here, we use experimental work, corroborated by molecular dynamics modeling to show that water concentration in the environment of the hydroxide anion, as well as temperature, significantly impact its reactivity. We compare different quaternary ammonium salts that have been previously studied and test their stabilities in the presence of relatively low hydroxide concentration in the presence of different amounts of solvating water molecules, as well as different temperatures. Remarkably, with the right amount of water and at low enough temperatures, even quaternary ammonium salts which are considered "unstable", present significantly improved lifetime.

  19. Proton exchange membranes for application in fuel cells: grafted silica/SPEEK nanocomposite elaboration and characterization.

    Science.gov (United States)

    Reinholdt, Marc X; Kaliaguine, Serge

    2010-07-06

    Hydrogen technologies and especially fuel cells are key components in the battle to find alternate sources of energy to the highly polluting and economically constraining fossil fuels in an aim to preserve the environment. The present paper shows the synthesis of surface functionalized silica nanoparticles, which are used to prepare grafted silica/SPEEK nanocomposite membranes. The nanoparticles are grafted either with hexadecylsilyl or aminopropyldimethylsilyl moieties or both. The synthesized particles are analyzed using XRD, NMR, TEM, and DLS to collect information on the nature of the particles and the functional groups, on the particle sizes, and on the hydrophilic/hydrophobic character. The composite membranes prepared using the synthesized particles and two SPEEK polymers with sulfonation degrees of 69.4% and 85.0% are characterized for their proton conductivity and water uptake properties. The corresponding curves are very similar for the composites prepared with both polymers and the nanoparticles bearing the two functional groups. The composites prepared with the nanoparticles bearing solely the aminopropyldimethylsilyl moiety exhibit lower conductivity and water uptake, possibly due to higher interaction of the polymer sulfonic acid sites with the amine groups. The composites prepared with the nanoparticles bearing solely the hexadecylsilyl moiety were not further investigated because of very high particles segregation. A study of the proton conductivity as a function of temperature was performed on selected membranes and showed that nanocomposites made with nanoparticles bearing both functional moieties have a higher conductivity at higher temperatures.

  20. 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...... in hot wire anemometry is the description of the Nusselt number as function of the Reynolds number and the Prandtl number, and in the current application it can be shown it is essential to employ a power-law equation instead of the commonly employed Churchill Bernstein equation. It will be shown...

  1. Analytical Investigation and Improvement of Performance of a Proton Exchange Membrane (Pem) Fuel Cell in Mobile Applications

    Science.gov (United States)

    Khazaee, I.

    2015-05-01

    In this study, the performance of a proton exchange membrane fuel cell in mobile applications is investigated analytically. At present the main use and advantages of fuel cells impact particularly strongly on mobile applications such as vehicles, mobile computers and mobile telephones. Some external parameters such as the cell temperature (Tcell ) , operating pressure of gases (P) and air stoichiometry (λair ) affect the performance and voltage losses in the PEM fuel cell. Because of the existence of many theoretical, empirical and semi-empirical models of the PEM fuel cell, it is necessary to compare the accuracy of these models. But theoretical models that are obtained from thermodynamic and electrochemical approach, are very exact but complex, so it would be easier to use the empirical and smi-empirical models in order to forecast the fuel cell system performance in many applications such as mobile applications. The main purpose of this study is to obtain the semi-empirical relation of a PEM fuel cell with the least voltage losses. Also, the results are compared with the existing experimental results in the literature and a good agreement is seen.

  2. Radiolytic preparation of ETFE and PFA based anion exchange membranes for alkaline fuel cell

    Science.gov (United States)

    Ko, Beom-Seok; Sohn, Joon-Yong; Nho, Young-Chang; Shin, Junhwa

    2011-11-01

    In this study, a versatile monomer, vinylbenzyl chloride (VBC) was radiolytically grafted onto a partially fluorinated ETFE and perfluorinated polymer PFA films. The VBC grafted films were treated with trimethylamine to prepare the alkaline anion exchange membranes (AAEMs). No significant differences in the ion exchange capacities and water uptakes were observed between the ETFE and PFA based AAEMs with similar degree of grafting (DOG). However, the distribution patterns of the graft chains over the cross-section of the ETFE and PFA based AAEMs were found to be quite different; the even distribution was observed from the ETFE based AAEMs while the uneven distribution was observed from the PFA based AAEMs. It was also found that the PFA based AAEMs have the higher ionic conductivity and chemical stability, compared to the ETFE based AAEMs.

  3. Anisotropic amplification of proton transport in proton exchange membrane fuel cells

    Science.gov (United States)

    Thimmappa, Ravikumar; Fawaz, Mohammed; Devendrachari, Mruthyunjayachari Chattanahalli; Gautam, Manu; Kottaichamy, Alagar Raja; Shafi, Shahid Pottachola; Thotiyl, Musthafa Ottakam

    2017-07-01

    Though graphene oxide (GO) membrane shuttles protons under humid conditions, it suffer severe disintegration and anhydrous conditions lead to abysmal ionic conductivity. The trade-off between mechanical integrity and ionic conductivity challenge the amplification of GO's ionic transport under anhydrous conditions. We show anisotropic amplification of GO's ionic transport with a selective amplification of in plane contribution under anhydrous conditions by doping it with a plant extract, phytic acid (PA). The hygroscopic nature of PA stabilized interlayer water molecules and peculiar geometry of sbnd OH functionalities around saturated hydrocarbon ring anisotropically enhanced ionic transport amplifying the fuel cell performance metrics.

  4. Low platinum loading for high temperature proton exchange membrane fuel cell developed by ultrasonic spray coating technique

    Science.gov (United States)

    Su, Huaneng; Jao, Ting-Chu; Barron, Olivia; Pollet, Bruno G.; Pasupathi, Sivakumar

    2014-12-01

    This paper reports use of an ultrasonic-spray for producing low Pt loadings membrane electrode assemblies (MEAs) with the catalyst coated substrate (CCS) fabrication technique. The main MEA sub-components (catalyst, membrane and gas diffusion layer (GDL)) are supplied from commercial manufacturers. In this study, high temperature (HT) MEAs with phosphoric acid (PA)-doped poly(2,5-benzimidazole) (AB-PBI) membrane are fabricated and tested under 160 °C, hydrogen and air feed 100 and 250 cc min-1 and ambient pressure conditions. Four different Pt loadings (from 0.138 to 1.208 mg cm-2) are investigated in this study. The experiment data are determined by in-situ electrochemical methods such as polarization curve, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The high Pt loading MEA exhibits higher performance at high voltage operating conditions but lower performances at peak power due to the poor mass transfer. The Pt loading 0.350 mg cm-2 GDE performs the peak power density and peak cathode mass power to 0.339 W cm-2 and 0.967 W mgPt-1, respectively. This work presents impressive cathode mass power and high fuel cell performance for high temperature proton exchange membrane fuel cells (HT-PEMFCs) with low Pt loadings.

  5. Non-covalent bonding interaction of surfactants with functionalized carbon nanotubes in proton exchange membranes for fuel cell applications.

    Science.gov (United States)

    Sayeed, M Abu; Kim, Young Ho; Park, Younjin; Gopalan, A I; Lee, Kwang-Pill; Choi, Sang-June

    2013-11-01

    Dispersion of functionalized multiwalled carbon nanotubes (MWCNTs) in proton exchange membranes (PEMs) was conducted via non-covalent bonding between benzene rings of various surfactants and functionalized MWCNTs. In the solution casting method, dispersion of functionalized MWCNTs in PEMs such as Nafion membranes is a critical issue. In this study, 1 wt.% pristine MWCNTs (p-MWCNTs) and oxidized MWCNTs (ox-MWCNTs) were reinforced in Nafion membranes by adding 0.1-0.5 wt.% of a surfactant such as benzalkonium chloride (BKC) as a cationic surfactant with a benzene ring, Tween-80 as a nonanionic surfactant without a benzene ring, sodium dodecylsulfonate (SDS) as an anionic surfactant without a benzene ring, or sodium dodecylben-zenesulfonate (SDBS) as an anionic surfactant with a benzene ring and their effects on the dispersion of nanocomposites were then observed. Among these surfactants, those with benzene rings such as BKC and SDBS produced enhanced dispersion via non-covalent bonding interaction between CNTs and surfactants. Specifically, the surfactants were adsorbed onto the surface of functionalized MWCNTs, where they prevented re-aggregation of MWCNTs in the nanocomposites. Furthermore, the prepared CNTs reinforced nanocomposite membranes showed reduced methanol uptake values while the ion exchange capacity values were maintained. The enhanced properties, including thermal property of the CNTs reinforced PEMs with surfactants, could be applicable to fuel cell applications.

  6. Anion- or Cation-Exchange Membranes for NaBH4/H2O2 Fuel Cells?

    Directory of Open Access Journals (Sweden)

    César A. C. Sequeira

    2012-07-01

    Full Text Available Direct borohydride fuel cells (DBFC, which operate on sodium borohydride (NaBH4 as the fuel, and hydrogen peroxide (H2O2 as the oxidant, are receiving increasing attention. This is due to their promising use as power sources for space and underwater applications, where air is not available and gas storage poses obvious problems. One key factor to improve the performance of DBFCs concerns the type of separator used. Both anion- and cation-exchange membranes may be considered as potential separators for DBFC. In the present paper, the effect of the membrane type on the performance of laboratory NaBH4/H2O2 fuel cells using Pt electrodes is studied at room temperature. Two commercial ion-exchange membranes from Membranes International Inc., an anion-exchange membrane (AMI-7001S and a cation-exchange membrane (CMI-7000S, are tested as ionic separators for the DBFC. The membranes are compared directly by the observation and analysis of the corresponding DBFC’s performance. Cell polarization, power density, stability, and durability tests are used in the membranes’ evaluation. Energy densities and specific capacities are estimated. Most tests conducted, clearly indicate a superior performance of the cation-exchange membranes over the anion-exchange membrane. The two membranes are also compared with several other previously tested commercial membranes. For long term cell operation, these membranes seem to outperform the stability of the benchmark Nafion membranes but further studies are still required to improve their instantaneous power load.

  7. Applying hot wire anemometry to directly measure the water balance in a proton exchange membrane fuel cell - Part 1

    DEFF Research Database (Denmark)

    Berning, Torsten; Al Shakhshir, Saher

    2015-01-01

    In order to accurately determine the water balance of a proton exchange membrane fuel cell it has recently been suggested to employ constant temperature anemometry (CTA), a frequently used method to measure the velocity of a fluid stream. CTA relies on convective heat transfer around a heated wire...... the equations required to calculate the heat transfer coefficient and the resulting voltage signal as function of the fuel cell water balance. The most critical and least understood part is the determination of the Nusselt number to calculate the heat transfer between the wire and the gas stream. Different...... for all current densities. Therefore, only one curve-fit equation will be required. The voltage curve E0 is an arbitrary calibration curve, and this can be conveniently chosen to be the voltage signal for a dry hydrogen stream at a given temperature and various flow rates which can be easily measured....

  8. Performance of Platinum Nanoparticles / Multiwalled Carbon Nanotubes / Bacterial Cellulose Composite as Anode Catalyst for Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Henry Fonda Aritonang

    2017-05-01

    Full Text Available Highly dispersed platinum (Pt nanoparticles / multiwalled carbon nanotubes (MWCNTs on bacterial cellulose (BC as anode catalysts for proton exchange membrane fuel cells (PEMFC were prepared with various precursors and their electro-catalytic activities towards hydrogen oxidation at 70 oC under non-humidified conditions. The composite was prepared by deposition of Pt nanoparticles and MWCNTs on BC gel by impregnation method using a water solution of metal precursors and MWCNTs followed by reducing reaction using a hydrogen gas. The composite was characterized by using TEM (transmission electron microscopy, EDS (energy dispersive spectroscopy, and XRD (X-ray diffractometry techniques. TEM images and XRD patterns both lead to the observation of spherical metallic Pt nanoparticles with mean diameter of 3-11 nm well impregnated into the BC fibrils. Preliminary tests on a single cell indicate that renewable BC is a good prospect to be explored as a membrane in fuel cell field. Copyright © 2017 BCREC Group. All rights reserved Received: 21st November 2016; Revised: 26th February 2017; Accepted: 27th February 2017 How to Cite: Aritonang, H.F., Kamu, V.S., Ciptati, C., Onggo, D., Radiman, C.L. (2017. Performance of Platinum Nanoparticles / Multiwalled Carbon Nanotubes / Bacterial Cellulose Composite as Anode Catalyst for Proton Exchange Membrane Fuel Cells. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2: 287-292 (doi:10.9767/bcrec.12.2.803.287-292 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.803.287-292

  9. The Effect of Inhomogeneous Compression on Water Transport in the Cathode of a Proton Exchange Membrane Fuel Cell

    DEFF Research Database (Denmark)

    Olesen, Anders Christian; Berning, Torsten; Kær, Søren Knudsen

    2012-01-01

    A three-dimensional, multicomponent, two-fluid model developed in the commercial CFD package CFX 13 (ANSYS Inc.) is used to investigate the effect of porous media compression on water transport in a proton exchange membrane fuel cell (PEMFC). The PEMFC model only consist of the cathode channel, gas....... Furthermore, the presence of irreducible liquid water is taken into account. In order to account for compression, porous media morphology variations are specified based on the gas diffusion layer (GDL) through-plane strain and intrusion which are stated as a function of compression. These morphology...... diffusion layer, microporous layer, and catalyst layer, excluding the membrane and anode. In the porous media liquid water transport is described by the capillary pressure gradient, momentum loss via the Darcy-Forchheimer equation, and mass transfer between phases by a nonequilibrium phase change model...

  10. Improving a free air breathing proton exchange membrane fuel cell through the Maximum Efficiency Point Tracking method

    Science.gov (United States)

    Higuita Cano, Mauricio; Mousli, Mohamed Islam Aniss; Kelouwani, Sousso; Agbossou, Kodjo; Hammoudi, Mhamed; Dubé, Yves

    2017-03-01

    This work investigates the design and validation of a fuel cell management system (FCMS) which can perform when the fuel cell is at water freezing temperature. This FCMS is based on a new tracking technique with intelligent prediction, which combined the Maximum Efficiency Point Tracking with variable perturbation-current step and the fuzzy logic technique (MEPT-FL). Unlike conventional fuel cell control systems, our proposed FCMS considers the cold-weather conditions, the reduction of fuel cell set-point oscillations. In addition, the FCMS is built to respond quickly and effectively to the variations of electric load. A temperature controller stage is designed in conjunction with the MEPT-FL in order to operate the FC at low-temperature values whilst tracking at the same time the maximum efficiency point. The simulation results have as well experimental validation suggest that propose approach is effective and can achieve an average efficiency improvement up to 8%. The MEPT-FL is validated using a Proton Exchange Membrane Fuel Cell (PEMFC) of 500 W.

  11. Hybrid membranes for fuel cells

    Science.gov (United States)

    Bochkareva, S. S.; Shashkina, S. S.

    2018-01-01

    Fuel cells are a very efficient, reliable, durable, and environmentally friendly energy source. Membranes for fuel cells were developed based on nitrogen-containing high-molecular compounds and organic–inorganic composites. Their electrical conductivities were measured. The influence of a silicon block of composites on the proton exchange properties of membranes was proved.The comparative characterization of the studied materials was performed.

  12. Molecular-Level Modeling of the Structure and Proton Transport within the Membrane Electrode Assembly of Hydrogen Proton Exchange Membrane Fuel Cells

    Science.gov (United States)

    Selvan, Myvizhi Esai; Keffer, David J.

    The creation of proton exchange membrane fuel cells (PEMFCs) in the early 1960's attracted great interest with the prospect of serving as a highly efficient and eco-friendly power source. This nascent technology found a broad range of applications spanning from spacecrafts to automobiles and electronic devices. The PEMFC in its simplest form consists of an anode, where the hydrogen fuel is catalytically electro-oxidized (dissociated into protons and electrons), a cathode, where oxygen is catalytically electro-reduced (combined with protons to form water) and a polymer electrolyte membrane, which serves as the structural framework of the cell and transports protons from anode to cathode, while the electrons are forced through the external circuit generating electricity. Today, fuel cell remains one of the most promising means of generating energy from alternative fuels, with tremendous potential to reduce oil dependence and carbon emissions. However, current PEMFCs have a relatively narrow operational range and a high cost of production, thus requiring significant experimental and theoretical research to develop a thorough understanding of this technology (at both the molecular and macroscopic scale), which will ultimately render the fuel cell as an economically viable option.

  13. Electrochemical characterization of proton exchange membrane fuel cells; Caracterizacao eletroquimica de celulas a combustivel de membrana polimerica trocadora de protons

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Jose Geraldo de Melo; Serra, Eduardo Torres [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)]. E-mail: furtado@cepel.br; Codeceira Neto, Alcides [Companhia HidroEletrica do Sao Francisco (CHESF), Recife, PE (Brazil)

    2008-07-01

    This paper describes the electrochemical behavior of a proton exchange membrane fuel cell in function of temperature and time of operation. Different polarization phenomena are considered in the 30 to 70 deg C temperature range, as well as the degradation of electrochemical behavior of the fuel cell analyzed up to 1260 hours of operation. The results show that there is a tendency for the experimental values approaching the theoretical as it increases the temperature of the membrane electrolyte. The electrochemical behavior of the PEMFC studied proved to be less stable at 70 deg C. On the other hand, at 30 deg C the fuel cell performance proved to be considerably lower than at other temperatures. Also, it was found that in certain current ranges occurs greater overlay in potential-current curves, and in some cases reversing between these curves depending on the electric current required for the data obtained at 60 and 70 deg C, indicating, perhaps, that at 70 deg C the characteristics of the electrolyte are slightly inferior to those at 70 deg C, corresponding to an electrolyte degradation. Additionally, for the system studied, we found that the rate of variation of the potential difference in function of the temperature is quite high at the beginning of the operation process and tends to stabilize in a level of around 2,3-2,5 {mu}V per minute for times greater than 330 hours of operation. (author)

  14. Recent Progress on the Key Materials and Components for Proton Exchange Membrane Fuel Cells in Vehicle Applications

    Directory of Open Access Journals (Sweden)

    Cheng Wang

    2016-07-01

    Full Text Available Fuel cells are the most clean and efficient power source for vehicles. In particular, proton exchange membrane fuel cells (PEMFCs are the most promising candidate for automobile applications due to their rapid start-up and low-temperature operation. Through extensive global research efforts in the latest decade, the performance of PEMFCs, including energy efficiency, volumetric and mass power density, and low temperature startup ability, have achieved significant breakthroughs. In 2014, fuel cell powered vehicles were introduced into the market by several prominent vehicle companies. However, the low durability and high cost of PEMFC systems are still the main obstacles for large-scale industrialization of this technology. The key materials and components used in PEMFCs greatly affect their durability and cost. In this review, the technical progress of key materials and components for PEMFCs has been summarized and critically discussed, including topics such as the membrane, catalyst layer, gas diffusion layer, and bipolar plate. The development of high-durability processing technologies is also introduced. Finally, this review is concluded with personal perspectives on the future research directions of this area.

  15. Water management in a single cell proton exchange membrane fuel cells with a serpentine flow field

    Science.gov (United States)

    Hassan, Nik Suhaimi Mat; Daud, Wan Ramli Wan; Sopian, Kamaruzzaman; Sahari, Jaafar

    Gas and water management is the key to achieving good performance from a polymer electrolyte membrane fuel cell (PEMFC) stack. Imbalance between production and evaporation rates can result in either flooding of the electrodes or membrane dehydration, both of which severely limit fuel cell performance. In the present study, a mathematical model was developed to evaluate moisture profiles of hydrogen and air flows in the flow field channels of both the anode and the cathode. For model validation, a single fuel cell was designed with an active area of 200 cm 2. Six humidity sensors were installed in the flow fields of both the anode and the cathode at 457 mm, 1266 mm and 2532 mm from the inlets. The experiment was performed using an Arbin Fuel Cell Test Station. The temperature was varied (25 °C, 40 °C, 50 °C and 60 °C), while hydrogen and air velocities were fixed at 3 L min -1 and 6 L min -1, respectively, during the operation of the single cell. The feed relative humidity at the anode was fixed at 1.0, while the feed relative humidity at the cathode was fixed at 0.005 (dry air). All humidity sensor readings were taken at steady state after 2 h of operation. Model predictions were then compared with experimental results by using the least squares algorithm. The moisture content was found to decrease along the flow field at the anode, but to increase at the cathode. The moisture content profile at the anode was shown to depend on the moisture Peclet number, which decreased with temperature. On the other hand, the moisture profile at the cathode was shown to depend on both the Peclet number and the Damkohler number. The trend of the Peclet number in the cathode followed closely that of the anode. The Damkohler number decreased with temperature, indicating increasing moisture mass transfer with temperature. The moisture profile models were successfully validated by the published data of the estimated overall mass transfer coefficient and moisture effective

  16. Channel aspect ratio effect for serpentine proton exchange membrane fuel cell: Role of sub-rib convection

    Science.gov (United States)

    Wang, Xiao-Dong; Duan, Yuan-Yuan; Yan, Wei-Mon; Lee, Duu-Jong; Su, Ay; Chi, Pei-Hung

    A complete three-dimensional, two-phase, non-isothermal model for proton exchange membrane (PEM) fuel cells was used to investigate the effect of the sub-rib convection on the performances for the single and triple serpentine flow fields at various channel aspect ratios and different thermal constraints. The occurrence of sub-rib convection, which is affected by the serpentine flow field, significantly influences the cell performance if the oxygen supply or membrane moisture content was limited. For single serpentine flow field in which sub-rib convection presents under all ribs, changing channel aspect ratio has minimal effects on cell performance since the oxygen supply is sufficient. For triple serpentine flow field or for serpentine cell with poor external heat loss, owing to limited sub-rib convection or to low membrane moisture content, decrease in channel aspect ratio significantly enhances cell performance. Blocking up the sub-rib convection markedly reduces cell performance. Flow field design for PEM fuel cell should take into consideration the effects of sub-rib convection flow on cell performance.

  17. Comparing the short and long term stability of biodegradable, ceramic and cation exchange membranes in microbial fuel cells.

    Science.gov (United States)

    Winfield, Jonathan; Chambers, Lily D; Rossiter, Jonathan; Ieropoulos, Ioannis

    2013-11-01

    The long and short-term stability of two porous dependent ion exchange materials; starch-based compostable bags (BioBag) and ceramic, were compared to commercially available cation exchange membrane (CEM) in microbial fuel cells. Using bi-directional polarisation methods, CEM exhibited power overshoot during the forward sweep followed by significant power decline over the reverse sweep (38%). The porous membranes displayed no power overshoot with comparably smaller drops in power during the reverse sweep (ceramic 8%, BioBag 5.5%). The total internal resistance at maximum power increased by 64% for CEM compared to 4% (ceramic) and 6% (BioBag). Under fixed external resistive loads, CEM exhibited steeper pH reductions than the porous membranes. Despite its limited lifetime, the BioBag proved an efficient material for a stable microbial environment until failing after 8 months, due to natural degradation. These findings highlight porous separators as ideal candidates for advancing MFC technology in terms of cost and operation stability. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Mechanical and transport properties of layer-by-layer electrospun composite proton exchange membranes for fuel cell applications.

    Science.gov (United States)

    Mannarino, Matthew M; Liu, David S; Hammond, Paula T; Rutledge, Gregory C

    2013-08-28

    Composite membranes composed of highly conductive and selective layer-by-layer (LbL) films and electrospun fiber mats were fabricated and characterized for mechanical strength and electrochemical selectivity. The LbL component consists of a proton-conducting, methanol-blocking poly(diallyl dimethyl ammonium chloride)/sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (PDAC/sPPO) thin film. The electrospun fiber component consists of poly(trimethyl hexamethylene terephthalamide) (PA 6(3)T) fibers in a nonwoven mat of 60-90% porosity. The bare mats were annealed to improve their mechanical properties, which improvements are shown to be retained in the composite membranes. Spray LbL assembly was used as a means for the rapid formation of proton-conducting films that fill the void space throughout the porous electrospun matrix and create a fuel-blocking layer. Coated mats as thin as 15 μm were fabricated, and viable composite membranes with methanol permeabilities 20 times lower than Nafion and through-plane proton selectivity five and a half times greater than Nafion are demonstrated. The mechanical properties of the spray coated electrospun mats are shown to be superior to the LbL-only system and possess intrinsically greater dimensional stability and lower mechanical hysteresis than Nafion under hydrated conditions. The composite proton exchange membranes fabricated here were tested in an operational direct methanol fuel cell. The results show the potential for higher open circuit voltages (OCV) and comparable cell resistances when compared to fuel cells based on Nafion.

  19. A COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF AIR FLOW THROUGH A TELECOM BACK-UP UNIT POWERED BY AN AIR-COOLED PROTON EXCHANGE MEMBRANE FUEL CELL

    OpenAIRE

    Gao, Xin; Berning, Torsten; Kær, Søren Knudsen

    2016-01-01

    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 heat. This product heat has to be effectively removed from the fuel cell, and while automotive fuel cells are usually liquid-cooled using a secondary coolant loop similar to the internal combustion engines,...

  20. Tolerance of non-platinum group metals cathodes proton exchange membrane fuel cells to air contaminants

    Science.gov (United States)

    Reshetenko, Tatyana; Serov, Alexey; Artyushkova, Kateryna; Matanovic, Ivana; Sarah Stariha; Atanassov, Plamen

    2016-08-01

    The effects of major airborne contaminants (SO2, NO2 and CO) on the spatial performance of Fe/N/C cathode membrane electrode assemblies were studied using a segmented cell system. The injection of 2-10 ppm SO2 in air stream did not cause any performance decrease and redistribution of local currents due to the lack of stably adsorbed SO2 molecules on Fe-Nx sites, as confirmed by density functional theory (DFT) calculations. The introduction of 5-20 ppm of CO into the air stream also did not affect fuel cell performance. The exposure of Fe/N/C cathodes to 2 and 10 ppm NO2 resulted in performance losses of 30 and 70-75 mV, respectively. DFT results showed that the adsorption energies of NO2 and NO were greater than that of O2, which accounted for the observed voltage decrease and slight current redistribution. The cell performance partially recovered when the NO2 injection was stopped. The long-term operation of the fuel cells resulted in cell performance degradation. XPS analyses of Fe/N/C electrodes revealed that the performance decrease was due to catalyst degradation and ionomer oxidation. The latter was accelerated in the presence of air contaminants. The details of the spatial performance and electrochemical impedance spectroscopy results are presented and discussed.

  1. 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.

  2. Thermochemical Stability Study of Alkyl-Tethered Quaternary Ammonium Cations for Anion Exchange Membrane Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Angela D.; Tignor, Steven E.; Sturgeon, Matthew R.; Long, Hai; Pivovar, Bryan S.; Bae, Chulsung

    2017-01-01

    The increased interest in the use of anion exchange membranes (AEMs) for applications in electrochemical devices has prompted significant efforts in designing materials with robust stability in alkaline media. Most reported AEMs suffer from polymer backbone degradation as well as cation functional group degradation. In this report, we provide comprehensive experimental investigations for the analysis of cation functional group stability under alkaline media. A silver oxide-mediated ion exchange method and an accelerated stability test in aqueous KOH solutions at elevated temperatures using a Parr reactor were used to evaluate a broad scope of quaternary ammonium (QA) cationic model compound structures, particularly focusing on alkyl-tethered cations. Additionally, byproduct analysis was employed to gain better understanding of degradation pathways and trends of alkaline stability. Experimental results under different conditions gave consistent trends in the order of cation stability of various QA small molecule model compounds. Overall, cations that are benzyl-substituted or that are near to electronegative atoms (such as oxygen) degrade faster in alkaline media in comparison to alkyl-tethered QAs. These comprehensive model compound stability studies provide valuable information regarding the relative stability of various cation structures and can help guide researchers towards designing new and promising candidates for AEM materials.

  3. Electrocatalytic oxidation of meso-erythritol in anion-exchange membrane alkaline fuel cell on PdAg/CNT catalyst

    Science.gov (United States)

    Benipal, Neeva; Qi, Ji; McSweeney, Ryan F.; Liang, Changhai; Li, Wenzhen

    2018-01-01

    C-C bond cleavage during electrocatalytic oxidation of glycerol and C3+ polyols often occurs and can significantly affect the Faradaic efficiency, fuel utilization, and output power density of a direct polyol fuel cell, although this has not been deeply investigated. With the goal of acquiring new knowledge of C-C bond breaking of polyols, this study examines the electrocatalytic oxidation of a C4 polyol meso-erythritol on carbon nanotube supported Pd-based catalysts (Pd/CNT, PdAg/CNT, and PdAg3/CNT) in an anion-exchange membrane fuel cell (AEMFC). Our results show that PdAg/CNT improves the fuel efficiency of meso-erythritol oxidation by contributing to the C-C bond cleavage of meso-erythritol in C3 and C2 chemicals. Based on the analysis of electro-oxidation products and half-cell cyclic voltammetry (CV) of intermediates, a meso-erythritol electro-oxidation pathway has been proposed to demonstrate that Ag is likely to assist Pd to promote the cleavage of C-C bonds of meso-erythritol.

  4. Influence of various carbon nano-forms as supports for Pt catalyst on proton exchange membrane fuel cell performance

    Science.gov (United States)

    Bharti, Abha; Cheruvally, Gouri

    2017-08-01

    In this study, we discuss the influence of various carbon supports for Pt on proton exchange membrane (PEM) fuel cell performance. Here, Pt supported on various carbon nano-forms [Pt/carbon black (Pt/CB), Pt/single-walled carbon nanotubes (Pt/SWCNT), Pt/multi-walled carbon nanotubes (Pt/MWCNT) and Pt/graphene (Pt/G)] are synthesized by a facile, single step, microwave-assisted, modified chemical reduction route. Their physical, chemical and electrochemical characteristics pertaining to oxygen reduction reaction (ORR) catalytic activity and stability in PEM fuel cell are studied in detail by various techniques and compared. The study shows that the different carbon supports does not significantly affect the Pt particle size during synthesis, but leads to different amount of defective sites in the carbon framework which influence both the availability of active metal nano-catalysts and metal-support interaction. In-situ electrochemical investigations reveal that the different carbon supports influence both ORR catalytic activity and stability of the catalyst. This is further corroborated by the demonstration of varying polarization characteristics on PEM fuel cell performance by different carbon supported Pt catalysts. This study reveals MWCNT as the most suitable carbon support for Pt catalyst, exhibiting high activity and stability for ORR in PEM fuel cell.

  5. Self assembled 12-tungstophosphoric acid-silica mesoporous nanocomposites as proton exchange membranes for direct alcohol fuel cells.

    Science.gov (United States)

    Tang, Haolin; Pan, Mu; Jiang, San Ping

    2011-05-21

    A highly ordered inorganic electrolyte based on 12-tungstophosphoric acid (H(3)PW(12)O(40), abbreviated as HPW or PWA)-silica mesoporous nanocomposite was synthesized through a facile one-step self-assembly between the positively charged silica precursor and negatively charged PW(12)O(40)(3-) species. The self-assembled HPW-silica nanocomposites were characterized by small-angle XRD, TEM, nitrogen adsorption-desorption isotherms, ion exchange capacity, proton conductivity and solid-state (31)P NMR. The results show that highly ordered and uniform nanoarrays with long-range order are formed when the HPW content in the nanocomposites is equal to or lower than 25 wt%. The mesoporous structures/textures were clearly presented, with nanochannels of 3.2-3.5 nm in diameter. The (31)P NMR results indicates that there are (≡SiOH(2)(+))(H(2)PW(12)O(40)(-)) species in the HPW-silica nanocomposites. A HPW-silica (25/75 w/o) nanocomposite gave an activation energy of 13.0 kJ mol(-1) and proton conductivity of 0.076 S cm(-1) at 100 °C and 100 RH%, and an activation energy of 26.1 kJ mol(-1) and proton conductivity of 0.05 S cm(-1) at 200 °C with no external humidification. A fuel cell based on a 165 μm thick HPW-silica nanocomposite membrane achieved a maximum power output of 128.5 and 112.0 mW cm(-2) for methanol and ethanol fuels, respectively, at 200 °C. The high proton conductivity and good performance demonstrate the excellent water retention capability and great potential of the highly ordered HPW-silica mesoporous nanocomposites as high-temperature proton exchange membranes for direct alcohol fuel cells (DAFCs).

  6. Anion-Exchange Membrane Fuel Cells with Improved CO2Tolerance: Impact of Chemically Induced Bicarbonate Ion Consumption.

    Science.gov (United States)

    Katayama, Yu; Yamauchi, Kosuke; Hayashi, Kohei; Okanishi, Takeou; Muroyama, Hiroki; Matsui, Toshiaki; Kikkawa, Yuuki; Negishi, Takayuki; Watanabe, Shin; Isomura, Takenori; Eguchi, Koichi

    2017-08-30

    Over the last few decades, because of the significant development of anion exchange membranes, increasing efforts have been devoted the realization of anion exchange membrane fuel cells (AEMFCs) that operate with the supply of hydrogen generated on-site. In this paper, ammonia was selected as a hydrogen source, following which the effect of conceivable impurities, unreacted NH 3 and atmospheric CO 2 , on the performance of AEMFCs was established. As expected, we show that these impurities worsen the performance of AEMFCs significantly. Furthermore, with the help of in situ attenuated total reflection infrared (ATR-IR) spectroscopy, it was revealed that the degradation of the cell performance was primarily due to the inhibition of the hydrogen oxidation reaction (HOR). This is attributed to the active site occupation by CO-related adspecies derived from (bi)carbonate adspecies. Interestingly, this degradation in the HOR activity is suppressed in the presence of both NH 3 and HCO 3 - because of the bicarbonate ion consumption reaction induced by the existence of NH 3 . Further analysis using in situ ATR-IR and electrochemical methods revealed that the poisonous CO-related adspecies were completely removed under NH 3 -HCO 3 - conditions, accompanied by the improvement in HOR activity. Finally, a fuel cell test was conducted by using the practical AEMFC with the supply of NH 3 -contained H 2 gas to the anode and ambient air to the cathode. The result confirmed the validity of this positive effect of NH 3 -HCO 3 - coexistence on CO 2 -tolerence of AEMFCs. The cell performance achieved nearly 95% of that without any impurity in the fuels. These results clearly show the impact of the chemically induced bicarbonate ion consumption reaction on the realization of highly CO 2 -tolerent AEMFCs.

  7. Instrument for layer-by-layer deposition of catalyst layers directly on proton exchange membrane for direct methanol fuel cell.

    Science.gov (United States)

    Wang, D; Wang, L; Liang, J; Liu, C

    2012-09-01

    A catalyst layer (CL) layer-by-layer (LbL) deposition instrument, consisting of an electrohydrodynamic atomization (EHDA) device and a proton exchange membrane (PEM) fixing device, has been developed. It has been used to deposit anode CL on Nafion membrane under different working distances of 4, 5, and 6 mm. The incorporation of EHDA LbL deposition allowed the generation of the CLs with different structures, where the higher working distance produced more porous CL structure. A catalyst-coated membrane (CCM) was also produced using this EHDA LbL deposition and PEM fixing device. It was observed that the catalyst has been uniformly coated on the Nafion membrane and the CCM presents an uniform surface feature. The performance of a single direct methanol fuel cell (DMFC) assembled with the deposited CCM at different working temperatures was analysed. The cell performance increased when the temperature rose. This instrument has the potential of being developed into a powerful device for controlling the deposition of CL of desired structures directly on PEM for DMFCs.

  8. Thermal-Conductivity Characterization of Gas Diffusion Layer in Proton Exchange Membrane Fuel Cells and Electrolyzers Under Mechanical Loading

    Science.gov (United States)

    Hamour, M.; Garnier, J. P.; Grandidier, J. C.; Ouibrahim, A.; Martemianov, S.

    2011-05-01

    Accurate information on the temperature field and associated heat transfer rates is particularly important for proton exchange membrane fuel cells (PEMFC) and PEM electrolyzers. An important parameter in fuel cell and electrolyzer performance analysis is the effective thermal conductivity of the gas diffusion layer (GDL) which is a solid porous medium. Usually, this parameter is introduced in modeling and performance analysis without taking into account the dependence of the GDL thermal conductivity λ (in W · m-1 · K-1) on mechanical compression. Nevertheless, mechanical stresses arising in an operating system can change significantly the thermal conductivity and heat exchange. Metrology allowing the characterization of the GDL thermal conductivity as a function of the applied mechanical compression has been developed in this study using the transient hot-wire technique (THW). This method is the best for obtaining standard reference data in fluids, but it is rarely used for thermal-conductivity measurements in solids. The experiments provided with Quintech carbon cloth indicate a strong dependence (up to 300%) of the thermal conductivity λ on the applied mechanical load. The experiments have been provided in the pressure range 0 cloth layers have been provided. The conducted experiments indicate the independence of the measured thermal conductivity on the number of GDL layers and, thus, justify the robustness of the developed method and apparatus for this type of application.

  9. Improvement the equation of polarization curve of a proton exchange membrane fuel cell at different channel geometry

    Science.gov (United States)

    Khazaee, I.

    2015-12-01

    The polarization curve of a proton exchange membrane fuel cell is an important parameter which is expressed by the change of voltage and current of it that indicates the performance of the cell. The voltage of the cell is a function of temperature that is expressed by the Nernst equation and the equation of voltage losses such as activation loss, ohmic loss and concentration loss. In this study a new correlation for polarization curve is obtained that it in addition to temperature, a new parameter is involved in it that shows the effect of the geometry of cross-section area of channels. For this purpose three PEM fuel cells with different channels geometry of rectangular, elliptical and triangular have constructed. The active area of each cell is 25 cm2 that its weight is 1300 g. The material of the gas diffusion layer is carbon clothes, the membrane is nafion 117 and the catalyst layer is a plane with 0.004 g/cm2 platinum. Also a test bench designed and constructed for testing the cell and a series of experiments are carried out to investigate the influence of the geometry of the cell on performance of the cell. The results show that when the geometry of channel is rectangular the performance of the cell is better than the triangular and elliptical channel.

  10. Analysis of alkaline exchange membrane fuel cells performance at different operating conditions using DC and AC methods

    Science.gov (United States)

    Reshetenko, Tatyana; Odgaard, Madeleine; Schlueter, Debbie; Serov, Alexey

    2018-01-01

    Membrane electrode assemblies (MEAs) for anion exchange membrane fuel cells (AEMFCs) were manufactured from commercial materials: Pt/C catalyst, A201 AEM and AS4 ionomer by using an industrial mass-production digital printing method. The MEA designs selected are close to those recommended by US Department of Energy, including low loading of platinum on the cathode side (0.2 mg cm-2). Polarization curves and electrochemical impedance spectroscopy (EIS) were applied for MEA evaluation in fuel cell conditions with variation of gas humidification and oxygen partial pressure (air vs oxygen). The typical impedance curves recorded at H2/O2 gas configuration consist of high- and medium-frequency arcs responsible for hydrogen oxidation and oxygen reduction, respectively. Operation with air as a cathode feed gas resulted in a decrease in AEMFC performance due to possible CO2 poisoning and mass transfer losses. At the same time, EIS demonstrated formation of a low frequency loop due to diffusion limitations. Despite the low loading of platinum on the cathode (0.2 mg cm-2), a peak power density of ∼330 mW cm-2 was achieved (at 50/50% of RH on anode and cathode), which is substantially higher performance than for AEMFC MEAs tested at similar conditions.

  11. Microwave Assisted Reduction of Pt-Catalyst by N-Phenyl-p-Phenylenediamine for Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Ming-Jer Tsai

    2017-03-01

    Full Text Available The presence of N-phenyl-p-phenylenediamine (PPDA: a dimer of aniline during microwave (MW irradiation can significantly improve Pt-loading on the XC72 carbon matrix as a catalyst support of proton exchange membrane fuel cells (PEMFCs. PPDA is converted to an emeraldine base state during MW-assisted redox reaction, which is characterized by both FTIR and Raman spectra. The increased degree of conjugation from the formation of quinone-state of PPDA is confirmed by UV-VIS spectra. TEM micrographs and residue weights obtained from the TGA thermograms illustrate the particle size and Pt-loading percent of Pt nanoparticles (NPs after MW irradiation, respectively. X-ray diffraction patterns indicate Pt NPs are successfully loaded on XC72 by MW irradiation corresponding to hydrothermal method. The single cell performance demonstrates an increasing power and maximum current density when Pt-catalyst of membrane exchanged assembly (MEA is prepared by MW-assisted reduction in the presence of PPDA.

  12. Pulsed plasma-polymerized alkaline anion-exchange membranes for potential application in direct alcohol fuel cells

    Science.gov (United States)

    Zhang, Chengxu; Hu, Jue; Cong, Jie; Zhao, Yanping; Shen, Wei; Toyoda, Hirotaka; Nagatsu, Masaaki; Meng, Yuedong

    Pulsed plasma polymerization is adopted to synthesize alkaline anion-exchange membranes (AAEMs) with high contents of functional groups. The attenuated total reflection Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermo gravimetric analysis demonstrate that the benzyltrimethylammonium cationic groups can be successfully introduced into the polymer matrix. The content of the quaternary nitrogen in pulsed plasma-polymerized membrane is up to 1.93 atom%. The ultra-flat and undamaged morphology structure of the AAEMs indicates a low plasma ablation effect in the pulsed plasma polymerization. The excellent properties of the pulsed plasma-polymerized AAEMs, including good adhesion to the substrate, acceptable chemical stability and thermal stability, high ion-exchange capacity (1.42 mmol g -1) and water uptake (59.73 wt%), interesting ionic conductivity (0.0205 S cm -1 in deionized water at 20 °C) and ethanol permeability (3.37 × 10 -11 m 2 s -1), suggest a great potential for application in direct alcohol fuel cells.

  13. The 3rd CARISMA international conference on medium and high temperature proton exchange membrane fuel cells: Three approaches to better platinum catalysts at biannual conference

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Cleemann, Lars Nilausen; Li, Qingfeng

    2013-01-01

    The 3rd CARISMA International Conference was held at the Axelborg venue in Copenhagen, Denmark, from September 3-5, 2012. The CARISMA conference series was specifically devoted to challenges in the development and testing of fuel cell materials and membrane electrode assemblies (MEAs) for proton...... exchange membrane fuel cells (PEMFCs) to be operated at intermediate and high temperatures. The conference series was initiated by the European CARISMA Coordination Action for Research on Intermediate and High Temperature Specialized Membrane Electrode Assemblies. The 2012 event in Copenhagen had around...

  14. Plasma Deposited Thin Iron Oxide Films as Electrocatalyst for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Lukasz JOZWIAK

    2017-02-01

    Full Text Available The possibility of using plasma deposited thin films of iron oxides as electrocatalyst for oxygen reduction reaction (ORR in proton exchange membrane fuel cells (PEMFC was examined. Results of energy-dispersive X-ray spectroscopy (EDX and X-ray photoelectron spectroscopy (XPS analysis indicated that the plasma deposit consisted mainly of FeOX structures with the X parameter close to 1.5. For as deposited material iron atoms are almost exclusively in the Fe3+ oxidation state without annealing in oxygen containing atmosphere. However, the annealing procedure can be used to remove the remains of carbon deposit from surface. The single cell test (SCT was performed to determine the suitability of the produced material for ORR. Preliminary results showed that power density of 0.23 mW/cm2 could be reached in the tested cell.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14406

  15. 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.

  16. Impedance characterization of high temperature proton exchange membrane fuel cell stack under the influence of carbon monoxide and methanol vapor

    DEFF Research Database (Denmark)

    Jeppesen, Christian; Polverino, Pierpaolo; Andreasen, Søren Juhl

    2017-01-01

    This work presents a comprehensive mapping of electrochemical impedance measurements under the influence of CO and methanol vapor contamination of the anode gas in a high temperature proton exchange membrane fuel cell, at varying load current. Electrical equivalent circuit model parameters based...... in an increase in the high frequency and intermediate frequency impedances. When adding CO and methanol to the anode gas, the low frequency part of the impedance spectrum is especially affected at high load currents, which is clearly seen as a result of the high load current resolution used in this work....... The negative effects of methanol vapor are found to be more pronounced on the series resistance. When CO and methanol vapor are both present in anode gas, the entire frequency spectrum and thereby all the equivalent circuit model parameters are affected. It is also shown that the trends of contamination...

  17. Investigating the effects of proton exchange membrane fuel cell conditions on carbon supported platinum electrocatalyst composition and performance

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Anant; Artyushkova, Kateryna; Atanassov, Plamen; Colbow, Vesna; Dutta, Monica; Harvey, Davie; Wessel, Silvia

    2011-12-01

    Changes that carbon-supported platinum electrocatalysts undergo in a proton exchange membrane fuel cell environment were simulated by ex situ heat treatment of catalyst powder samples at 150 C and 100% relative humidity. In order to study modifications that are introduced to chemistry, morphology, and performance of electrocatalysts, XPS, HREELS and three-electrode rotating disk electrode experiments were performed. Before heat treatment, graphitic content varied by 20% among samples with different types of carbon supports, with distinct differences between bulk and surface compositions within each sample. Following the aging protocol, the bulk and surface chemistry of the samples were similar, with graphite content increasing or remaining constant and Pt-carbide decreasing for all samples. From the correlation of changes in chemical composition and losses in performance of the electrocatalysts, we conclude that relative distribution of Pt particles on graphitic and amorphous carbon is as important for electrocatalytic activity as the absolute amount of graphitic carbon present

  18. Investigating the effects of proton exchange membrane fuel cell conditions on carbon supported platinum electrocatalyst composition and performance

    Energy Technology Data Exchange (ETDEWEB)

    A. Patel; K. Artyushkova; P. Atanassov; V. Colbow; M. Dutta; D. Harvey; S. Wessel

    2012-04-30

    Changes that carbon-supported platinum electrocatalysts undergo in a proton exchange membrane fuel cell environment were simulated by ex situ heat treatment of catalyst powder samples at 150 C and 100% relative humidity. In order to study modifications that are introduced to chemistry, morphology, and performance of electrocatalysts, XPS, HREELS and three-electrode rotating disk electrode experiments were performed. Before heat treatment, graphitic content varied by 20% among samples with different types of carbon supports, with distinct differences between bulk and surface compositions within each sample. Following the aging protocol, the bulk and surface chemistry of the samples were similar, with graphite content increasing or remaining constant and Pt-carbide decreasing for all samples. From the correlation of changes in chemical composition and losses in performance of the electrocatalysts, we conclude that relative distribution of Pt particles on graphitic and amorphous carbon is as important for electrocatalytic activity as the absolute amount of graphitic carbon present

  19. Technique for characterization of the wettability properties of gas diffusion media for proton exchange membrane fuel cells.

    Science.gov (United States)

    Gurau, Vladimir; Mann, J Adin

    2010-10-15

    In this paper, a measurement technique based on the capillary penetration method is presented for use in estimating the wettability properties of gas diffusion media (GDM), a component for proton exchange membrane fuel cells (PEMFCs). The present method solves several critical issues, including the formation of an external meniscus and the evaporation of imbibed solvent, both of which greatly affect the apparent rate of solvent imbibition. Solvent evaporation is prevented by inserting a GDM sample between two thin stainless steel plates to form a tri-layer structure having non-porous evaporation covers on each side of the porous GDM sample. The presence of stainless steel plates in contact with the GDM sample was demonstrated to have a negligible impact on the evaluation of the Washburn material constant. Copyright 2010 Elsevier Inc. All rights reserved.

  20. SIMULATION OF POROSITY AND PTFE CONTENT IN GAS DIFFUSION LAYER ON PROTON EXCHANGE MEMBRANE FUEL CELL PERFORMANCE

    Directory of Open Access Journals (Sweden)

    NUR H. MASLAN

    2016-01-01

    Full Text Available Numerous research and development activities have been conducted to optimize the operating parameters of a proton exchange membrane fuel cell (PEMFC by experiments and simulations. This study explains the development of a 3D model by using ANSYS FLUENT 14.5 to determine the optimum PEMFC parameters, namely, porosity and polytetrafluoroethylene (PTFE content, in the gas diffusion layer (GDL. A 3D model was developed to analyze the properties and effects of GDL. Simulation results showed that the increase in GDL porosity significantly improved the performance of PEMFC in generating electrical power. However, the performance of PEMFC decreased with increasing PTFE content in GDL. Thus, the PTFE content in the GDL must be optimized and the optimum PTFE content should be 5 wt%. The model developed in this simulation showed good capability in simulating the PEMFC parameters to assist the development process of PEMFC design.

  1. Effects of proton exchange membrane on the performance and microbial community composition of air-cathode microbial fuel cells.

    Science.gov (United States)

    Lee, Yun-Yeong; Kim, Tae Gwan; Cho, Kyung-Suk

    2015-10-10

    This study investigated the effects of proton exchange membranes (PEMs) on performance and microbial community of air-cathode microbial fuel cells (MFCs). Air-cathode MFCs with reactor volume of 1L were constructed in duplicate with or without PEM (designated as ACM-MFC and AC-MFC, respectively) and fed with a mixture of glucose and acetate (1:1, w:w). The maximum power density and coulombic efficiency did not differ between MFCs in the absence or presence of a PEM. However, PEM use adversely affected maximum voltage production and the rate of organic compound removal (p0.9 and pelectricity generation in MFC systems. Taken together, these findings demonstrate that MFC systems without PEM are more efficient with respect to power production and COD removal as well as exoelectrogen growth. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. 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

    In order to develop cheaper and better fuel-cell electrolyte membranes than the polyperfluorosulfonic acids, an effort has been made to improve the fuel-cell relevant properties of sulfonated styrene/divinylbenzenegrafted poly(ethylene-alt-tetrafluoroethylene) membranes. Thus the influence of the...

  3. Experimental diagnostics and modeling of inductive phenomena at low frequencies in impedance spectra of proton exchange membrane fuel cells

    Science.gov (United States)

    Pivac, Ivan; Šimić, Boris; Barbir, Frano

    2017-10-01

    Representation of fuel cell processes by equivalent circuit models, involving resistance and capacitance elements representing activation losses on both anode and cathode in series with resistance representing ohmic losses, cannot capture and explain the inductive loop that may show up at low frequencies in Nyquist diagram representation of the electrochemical impedance spectra. In an attempt to explain the cause of the low-frequency inductive loop and correlate it with the processes within the fuel cell electrodes, a novel equivalent circuit model of a Proton Exchange Membrane (PEM) fuel cell has been proposed and experimentally verified here in detail. The model takes into account both the anode and the cathode, and has an additional resonant loop on each side, comprising of a resistance, capacitance and inductance in parallel representing the processes within the catalyst layer. Using these additional circuit elements, more accurate and better fits to experimental impedance data in the wide frequency range at different current densities, cell temperatures, humidity of gases, air flow stoichiometries and backpressures were obtained.

  4. 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)

  5. High energy efficiency and high power density proton exchange membrane fuel cells: Electrode kinetics and mass transport

    Science.gov (United States)

    Srinivasan, Supramaniam; Velev, Omourtag A.; Parthasathy, Arvind; Manko, David J.; Appleby, A. John

    1991-01-01

    The development of proton exchange membrane (PEM) fuel cell power plants with high energy efficiencies and high power densities is gaining momentum because of the vital need of such high levels of performance for extraterrestrial (space, underwater) and terrestrial (power source for electric vehicles) applications. Since 1987, considerable progress has been made in achieving energy efficiencies of about 60 percent at a current density of 200 mA/sq cm and high power densities (greater than 1 W/sq cm) in PEM fuel cells with high (4 mg/sq cm) or low (0.4 mg/sq cm) platinum loadings in electrodes. The following areas are discussed: (1) methods to obtain these high levels of performance with low Pt loading electrodes - by proton conductor impregnation into electrodes, localization of Pt near front surface; (2) a novel microelectrode technique which yields electrode kinetic parameters for oxygen reduction and mass transport parameters; (3) demonstration of lack of water transport from anode to cathode; (4) modeling analysis of PEM fuel cell for comparison with experimental results and predicting further improvements in performance; and (5) recommendations of needed research and development for achieving the above goals.

  6. 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 Fuel cells are well-known electric generating devices which have higher energy conversion efficiency than heat engines and less exhaustion of carbon dioxide (CO2)1. There are several types of fuel cells. Solid oxide fuel cells (SOFC) and molten...

  7. Development of proton exchange membranes fuel cells with sulfonated HTPB-phenol; Desenvolvimento de membranas polimericas trocadoras de protons utilizando PBLH-fenol

    Energy Technology Data Exchange (ETDEWEB)

    Ferraz, Fernando A.; Oliveira, Angelo R.S.; Cesar-Oliveira, Maria Aparecida F. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica. Lab. de Polimeros Sinteticos], e-mail: ferraz@quimica.ufpr.br; Cantao, Mauricio P. [LACTEC - Instituto de Tecnologia para o Desenvolvimento, Curitiba, PR (Brazil). Centro Politecnico

    2007-07-01

    Proton exchange membrane fuel cells (PEMFC) have been paid attention as promising candidates for vehicle and portable applications. PEMFC employ proton exchange polymer membrane which serves as an electrolyte between anode and cathode. Nafion{sup R} (DuPont), perfluorosulfonic acid/PTFE copolymer membranes are typically used as the polymer electrolyte in PEMFC due to their good chemical and mechanical properties as well as high proton conductivity. However, high cost of these materials is one of main obstacles for commercialization of PEMFC. Extensive efforts have been devoted to develop alternative polymer electrolyte membranes. Our group have investigated the development of proton exchange membranes fuel cells using sulfonated HTPB-Phenyl ether (HTPB-Phenol), making possible the formation of membranes with sulfonated groups amount of 2,4, 2,5 and 2,8 mmol/g of dry polymer from HTPB-Phenol 80, 98 and 117 respectively. These results mean a bigger values than those of the Nafion{sup R} membranes, that possess an ion exchange capacity of 0,67 up to 1,25 mmol/g of sulfonated groups. (author)

  8. High-performance membrane electrode assembly with multi-functional Pt/SnO2eSiO2/C catalyst for proton exchange membrane fuel cell operated under low-humidity conditions

    CSIR Research Space (South Africa)

    Hou, S

    2016-06-01

    Full Text Available A novel self-humidifying membrane electrode assembly (MEA) with homemade multifunctional Pt/SnO(sub2)-SiO(sub2)/C as the anode was developed to improve the performance of a proton exchange membrane fuel cell under low humidity. The MEAs' performance...

  9. Insights into the role of wettability in cathode catalyst layer of proton exchange membrane fuel cell : pore scale immiscible flow and transport processes

    NARCIS (Netherlands)

    Fathi, H.; Raoof, A.; Mansouri, S.H.

    2017-01-01

    The production of liquid water in cathode catalyst layer, CCL, is a significant barrier to increase the efficiency of proton exchange membrane fuel cell. Here we present, for the first time, a direct three-dimensional pore-scale modelling to look at the complex immiscible two-phase flow in CCL.

  10. Synthesis and characterization of nanostructured sulfonated polyimides for proton exchange membrane fuel cells

    Science.gov (United States)

    Zou, Lijun

    Sulfonated polyimides (SPI) are considered to be good candidates for proton exchange membranes (PEMs) since they exhibit high strength, good film-forming ability, chemical resistance, thermal stability, and, in their hydrated state, relatively high proton conductivity. Despite intense research in the area of SPIs, fundamental investigations of hydrophilic/hydrophobic phase segregation and studies of humidity dependent morphologies are scarce. In an effort to influence the order and distribution of ionic groups in rigid-rod SPIs and to understand the interrelationships between morphology, hydration and proton conductivity, two novel model systems of SPI polymers containing hydrophobic polysiloxane (SPI-PSX) and hydrophilic silica nanoparticles (SPI-Si) were developed. The first model system of sulfonated polyimide containing hydrophobic polysiloxane segmented copolymers was prepared by a one-pot synthesis. SPI-PSX materials were evaluated using 1H NMR, size-exclusion chromatography. The presence of ion-containing diamines in the reaction mixture was found to inhibit stoichiometric incorporation of hydrophobic siloxane segments. Siloxane segments were found to lower the thermal stability of the polyimide host. Equilibrium water sorption studies of free standing films of copolymers with and without siloxane segments show that the presence of siloxane segments does not interfere with water swelling, which suggests a microphase-segregated morphology may exist. TEM and SAXS analyses show evidence of phase-segregation in sulfonated polyimides and reveal that siloxane segments strongly affect ionic clustering. However, proton conductivity only changes slightly when polysiloxane segments are incorporated. Sulfonated polyimides containing hydrophilic silica nanoparticles is our second model system developed for stabilizing the dispersed morphologies to promote proton conductivity. SPI-Si nanocomposites were prepared by a pre-polymer of anhydride-terminated sulfonated

  11. Development of next generation micro-CHP system: Based on high temperature proton exchange membrane fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Arsalis, A.

    2012-01-15

    Novel proposals for the modeling and operation of a micro-CHP (combined-heat-and-power) residential system based on HT-PEMFC (High Temperature-Proton Exchange Membrane Fuel Cell) technology are described and analyzed to investigate the technical feasibility of such systems. The proposed systems must provide electricity, hot water, and space heating for an average single-family household in Denmark. A complete fuel processing subsystem, with all necessary BOP (balance-of-plant) components, is modeled and coupled to the fuel cell stack subsystem. The research project is divided into five main study topics: (a) Modeling, simulation and validation of the system in LabVIEW environment to provide the ability of Data Acquisition of actual components, and thereby more realistic design in the future; (b) Modeling, parametric study, and sensitivity analysis of the system in EES (Engineering Equation Solver). The parametric study is conducted to determine the most viable system/component design based on maximizing total system efficiency; (c) An improved operational strategy is formulated and applied in an attempt to minimize operational implications, experienced when using conventional operational strategies; (d) Application of a GA (Genetic Algorithm) optimization strategy. The objective function of the single-objective optimization strategy is the net electrical efficiency of the micro-CHP system. The implemented optimization procedure attempts to maximize the objective function by variation of nine decision variables; (e) The micro-CHP system is optimized by formulating and applying a process integration methodology. The methodology involves system optimization targeting in net electrical efficiency maximization. Subsequently a MINLP (Mixed Integer Non-Linear Programming) problem optimization strategy is applied to minimize the annual cost of the HEN (Heat Exchanger Network). The results obtained throughout this research work indicate the high potential of the proposed

  12. A review on prognostics and health monitoring of proton exchange membrane fuel cell

    OpenAIRE

    Sutharssan, T.; Montalvão, Diogo; Chen, Y.K.; Wang, W.C.; Pisac, C.; Elemara, H.

    2017-01-01

    Fuel cell technology can be traced back to 1839 when British scientist Sir William Grove discovered that it was possible to generate electricity by the reaction between hydrogen and oxygen gases. However, fuel cell still cannot compete with internal combustion engines although they have many advantages including zero carbon emissions. Fossil fuels are cheaper and present very high volumetric energy densities compared with the hydrogen gas. Furthermore, hydrogen storage as a liquid is still a ...

  13. Three order state space modeling of proton exchange membrane fuel cell with energy function definition

    Energy Technology Data Exchange (ETDEWEB)

    Becherif, M. [University of Technology of Belfort-Montbeliard, SeT-FCLab, UTBM, 90010 Belfort Cedex (France); Hissel, D. [University of Franche Comte, FEMTO-ST/FCLab, UMR CNRS 6174, 90010 Belfort Cedex (France); Gaagat, S. [Department of Chemical Engineering, IIT Guwahati, Assam (India); Wack, M. [SeT, UTBM, 90010 Belfort Cedex (France)

    2010-10-01

    The fuel cell is a complex system which is the centre of a lot of multidisciplinary research activities since it involves intricate application of various fields of study. The operation of a fuel cell depends on a wide range of parameters. The effect of one cannot be studied in isolation without disturbing the system which makes it very difficult to comprehend, analyze and predict various phenomena occurring in the fuel cell. In the current work, we present an equivalent electrical circuit of the pneumatics and fluidics in a fuel cell stack. The proposed model is based on the physical phenomena occurring inside fuel cell stack where we define the fluidic-electrical and pneumatic-electrical analogy. The effect of variation in temperature and relative humidity on the cell are considered in this model. The proposed model, according to the considered hypothesis, is a simple three order state space model which is suitable for the control purpose where a desired control structure can be formulated for high-end applications of the fuel cell as a subpart of a larger system, for instance, in hybrid propulsion of vehicles coupled with batteries and supercapacitors. Another key point of our work is the definition of the natural fuel cell stack energy function. The circuit analysis equations are presented and the simulated model is validated using the experimental data obtained using the fuel cell test bench available in Fuel Cell Laboratory, France. (author)

  14. Three order state space modeling of proton exchange membrane fuel cell with energy function definition

    Science.gov (United States)

    Becherif, M.; Hissel, D.; Gaagat, S.; Wack, M.

    The fuel cell is a complex system which is the centre of a lot of multidisciplinary research activities since it involves intricate application of various fields of study. The operation of a fuel cell depends on a wide range of parameters. The effect of one cannot be studied in isolation without disturbing the system which makes it very difficult to comprehend, analyze and predict various phenomena occurring in the fuel cell. In the current work, we present an equivalent electrical circuit of the pneumatics and fluidics in a fuel cell stack. The proposed model is based on the physical phenomena occurring inside fuel cell stack where we define the fluidic-electrical and pneumatic-electrical analogy. The effect of variation in temperature and relative humidity on the cell are considered in this model. The proposed model, according to the considered hypothesis, is a simple three order state space model which is suitable for the control purpose where a desired control structure can be formulated for high-end applications of the fuel cell as a subpart of a larger system, for instance, in hybrid propulsion of vehicles coupled with batteries and supercapacitors. Another key point of our work is the definition of the natural fuel cell stack energy function. The circuit analysis equations are presented and the simulated model is validated using the experimental data obtained using the fuel cell test bench available in Fuel Cell Laboratory, France.

  15. Synthesis and characterization of sulfonated poly (arylene ether sulfone) copolymers via direct copolymerization: Candidates for proton exchange membrane fuel cells

    Science.gov (United States)

    Harrison, William Lamont

    A designed series of directly copolymerized homo- and disulfonated copolymers containing controlled degrees of pendant sulfonic acid groups have been synthesized via nucleophilic step polymerization. Novel sulfonated poly (arylene ether sulfone) copolymers using 4,4'-bisphenol A, 4,4'-biphenol, hexafluorinated (6F) bisphenol AF, and hydroquinone, respectively, with dichlorodiphenyl sulfone (DCDPS) and 3,3'-disodiumsulfonyl-4,4'-dichlorodiphenylsulfone (SDCDPS) were investigated. Molar ratios of DCDPS and SDCDPS were systematically varied to produce copolymers of controlled compositions, which contained up to 70 mol% of disulfonic acid moiety. The goal is to identify thermally, hydrolytically, and oxidatively stable high molecular weight, film-forming, ductile ion conducting copolymers, which had properties desirable for proton exchange membranes (PEM) in fuel cells. Commercially available bisphenols were selected to produce cost effective alternative PEMs. Partially aliphatic bisphenol A and hexafluorinated (6F) bisphenol AF produced amorphous copolymers with different thermal oxidative and surface properties. Biphenol and hydroquinone was utilized to produce wholly aromatic copolymers. The sulfonated copolymers were prepared in the sodium-salt form and converted to the acid moiety via two different methodologies and subsequently investigated as proton exchange membranes for fuel cells. Hydrophilicity increased with the level of disulfonation, as expected. Moreover, water sorption increased with increasing mole percent incorporation of SDCDPS. The copolymers' water uptake was a function of both bisphenol structure and degree of disulfonation. Furthermore, the acidification procedures were shown to influence the Tg values, water uptake, and conductivity of the copolymers. Atomic force microscopy (AFM) in the tapping mode confirmed that the morphology of the copolymers could be designed to display nanophase separation in the hydrophobic and hydrophilic (sulfonated

  16. Thermal and electrochemical durability of carbonaceous composites used as a bipolar plate of proton exchange membrane fuel cell

    Science.gov (United States)

    Kinumoto, Taro; Nagano, Keita; Tsumura, Tomoki; Toyoda, Masahiro

    Thermal and electrochemical durability of carbonaceous composite plates, which are made from graphite powders and a resin for use as bipolar plates of PEMFC (proton exchange membrane fuel cell), were investigated. The thermal durability was investigated by TG (thermal gravimetry) coupled with DTA (differential thermal analysis) technique under air up to 600 °C. A weight loss was significant over 300 °C, but the hydrophobicity was decreased after heated at 80 °C for 192 h. The electrochemical durability was investigated in 10 μmol dm -3 of hydrochloric acid solution under nitrogen or oxygen atmosphere by means of potential holding test from 0.8 to 1.5 V against RHE (reversible hydrogen electrode) at 80 °C. During the potential holding tests, CO 2 production due to the corrosion was quantified by a GC (gas-chromatography) and the production was detectable above 1.3 V irrespective with atmosphere; on the other hand, it was clarified from the contact angle measurements that the hydrophobicity was changed below 1.3 V. The results of this study showed that the carbonaceous composite plates were electrochemically degraded under PEMFC condition and were seriously degraded in URFC (unitized regenerative fuel cell) condition.

  17. CO-Tolerant Pt–BeO as a Novel Anode Electrocatalyst in Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Kyungjung Kwon

    2016-05-01

    Full Text Available Commercialization of proton exchange membrane fuel cells (PEMFCs requires less expensive catalysts and higher operating voltage. Substantial anodic overvoltage with the usage of reformed hydrogen fuel can be minimized by using CO-tolerant anode catalysts. Carbon-supported Pt–BeO is manufactured so that Pt particles with an average diameter of 4 nm are distributed on a carbon support. XPS analysis shows that a peak value of the binding energy of Be matches that of BeO, and oxygen is bound with Be or carbon. The hydrogen oxidation current of the Pt–BeO catalyst is slightly higher than that of a Pt catalyst. CO stripping voltammetry shows that CO oxidation current peaks at ~0.85 V at Pt, whereas CO is oxidized around 0.75 V at Pt–BeO, which confirms that the desorption of CO is easier in the presence of BeO. Although the state-of-the-art PtRu anode catalyst is dominant as a CO-tolerant hydrogen oxidation catalyst, this study of Be-based CO-tolerant material can widen the choice of PEMFC anode catalyst.

  18. Degradation of graphene coated copper in simulated proton exchange membrane fuel cell environment: Electrochemical impedance spectroscopy study

    Science.gov (United States)

    Ren, Y. J.; Anisur, M. R.; Qiu, W.; He, J. J.; Al-Saadi, S.; Singh Raman, R. K.

    2017-09-01

    Metallic materials are most suitable for bipolar plates of proton exchange membrane fuel cell (PEMFC) because they possess the required mechanical strength, durability, gas impermeability, acceptable cost and are suitable for mass production. However, metallic bipolar plates are prone to corrosion or they can passivate under PEMFC environment and interrupt the fuel cell operation. Therefore, it is highly attractive to develop corrosion resistance coating that is also highly conductive. Graphene fits these criteria. Graphene coating is developed on copper by chemical vapor deposition (CVD) with an aim to improving corrosion resistance of copper under PEMFC condition. The Raman Spectroscopy shows the graphene coating to be multilayered. The electrochemical degradation of graphene coated copper is investigated by electrochemical impedance spectroscopy (EIS) in 0.5 M H2SO4 solution at room temperature. After exposure to the electrolyte for up to 720 h, the charge transfer resistance (Rt) of the graphene coated copper is ∼3 times greater than that of the bare copper, indicating graphene coatings could improve the corrosion resistance of copper bipolar plates.

  19. Carbon nanofiber growth optimization for their use as electrocatalyst support in proton exchange membrane (PEM) fuel cells.

    Science.gov (United States)

    Lázaro, M J; Sebastián, D; Suelves, I; Moliner, R

    2009-07-01

    Carbon nanofiber (CNF) growth by catalytic decomposition of methane in a fixed-bed reactor was studied out to elucidate the influence of some important reaction conditions: temperature, space velocity and reactant partial pressure, in the morphological properties of the carbonaceous material obtained. The main objective is to synthesize a suitable carbonaceous nanomaterial to be used as support in platinum based electrocatalysts for Proton Exchange Membrane Fuel Cells (PEMFC) which improves current carbon blacks. High specific surface area is required in an electrocatalyst support since platinum dispersion is enhanced and so a cost-effective usage and high catalytic activity. Good electrical conductivity of carbon support is also required since the fuel cell power density is improved. With this proposal, characterization was carried out by nitrogen physisorption, XRD, SEM and TPO. The results were analysed by a factorial design and analysis of variance (ANOVA) in order to find an empirical correlation between operating conditions and CNF characteristics. It was found that the highest specific surface area and pore volume were found at 823 K and at a space velocity of 10 L gcat(-1) h(-1). The graphitic character of CNF, which is known to influence the electrical conductivity, presented a maximum value at temperatures between 923 K and 973 K. SEM images showed a narrow size distribution of CNF diameter between 40 and 90 nm and homogeneous appearance.

  20. Compact Design of 10 kW Proton Exchange Membrane Fuel Cell Stack Systems with Microcontroller Units

    Directory of Open Access Journals (Sweden)

    Hsiaokang Ma

    2014-04-01

    Full Text Available In this study, fuel, oxidant supply and cooling systems with microcontroller units (MCU are developed in a compact design to fit two 5 kW proton exchange membrane fuel cell (PEMFC stacks. At the initial stage, the testing facility of the system has a large volume (2.0 m × 2.0 m × 1.5 m with a longer pipeline and excessive control sensors for safe testing. After recognizing the performance and stability of stack, the system is redesigned to fit in a limited space (0.4 m × 0.5 m × 0.8 m. Furthermore, the stack performance is studied under different hydrogen recycling modes. Then, two similar 5 kW stacks are directly coupled with diodes to obtain a higher power output and safe operation. The result shows that the efficiency of the 5 kW stack is 43.46% with a purge period of 2 min with hydrogen recycling and that the hydrogen utilization rate µf is 66.31%. In addition, the maximum power output of the twin-coupled module (a power module with two stacks in electrical cascade/parallel arrangement is 9.52 kW.

  1. Numerical simulation and experimental validation of liquid water behaviors in a proton exchange membrane fuel cell cathode with serpentine channels

    Science.gov (United States)

    Le, Anh Dinh; Zhou, Biao; Shiu, Huan-Ruei; Lee, Chun-I.; Chang, Wen-Chen

    The volume-of-fluid (VOF) approach is one of the most promising methods of investigating water transport and water management in proton exchange membrane fuel cells (PEMFCs). A general PEMFC model combined with the VOF method has been developed by our group to simulate the mechanisms of fluid flows, mass and heat transport, and electrochemical reactions in a PEMFC, and it is necessary to validate the numerical model through experiments. In this paper, both the numerical model and an experimental visualization that can simulate the motion and transport behavior of liquid water in a cathode flow channel of a PEMFC are presented. Direct optical visualization is used in this work to capture the droplets' motions with high spatial and temporal resolutions. The numerical model and experimental setup have similar geometric dimensions and operating conditions, and the results of the experiment are in good agreement with numerical simulations. Moreover, the physics of droplet and liquid water behavior based on certain material and liquid properties and the operating conditions in the fuel cell channel are also addressed. This analysis also offers some basic understanding of the mechanism of liquid droplet dynamics in numerical and experimental studies of micro-fluidics.

  2. Modeling two-phase flow in three-dimensional complex flow-fields of proton exchange membrane fuel cells

    Science.gov (United States)

    Kim, Jinyong; Luo, Gang; Wang, Chao-Yang

    2017-10-01

    3D fine-mesh flow-fields recently developed by Toyota Mirai improved water management and mass transport in proton exchange membrane (PEM) fuel cell stacks, suggesting their potential value for robust and high-power PEM fuel cell stack performance. In such complex flow-fields, Forchheimer's inertial effect is dominant at high current density. In this work, a two-phase flow model of 3D complex flow-fields of PEMFCs is developed by accounting for Forchheimer's inertial effect, for the first time, to elucidate the underlying mechanism of liquid water behavior and mass transport inside 3D complex flow-fields and their adjacent gas diffusion layers (GDL). It is found that Forchheimer's inertial effect enhances liquid water removal from flow-fields and adds additional flow resistance around baffles, which improves interfacial liquid water and mass transport. As a result, substantial improvements in high current density cell performance and operational stability are expected in PEMFCs with 3D complex flow-fields, compared to PEMFCs with conventional flow-fields. Higher current density operation required to further reduce PEMFC stack cost per kW in the future will necessitate optimizing complex flow-field designs using the present model, in order to efficiently remove a large amount of product water and hence minimize the mass transport voltage loss.

  3. Energy dispersive X-ray diffraction applied to laboratory investigation on proton exchange membrane water content in working fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Isopo, A.; Rossi Albertini, V. [Istituto di Struttura della Materia - CNR, Roma (Italy); Nobili, F. [Scuola di Scienze e Tecnologie - Sezione Chimica, Universita degli Studi di Camerino (Italy)

    2012-10-15

    An original method, based on the energy-dispersive X-ray diffraction, has been recently proposed as a possible laboratory tool to accomplish long time resolved investigation of the water content in a proton exchange membrane fuel cell. However, this method has never been applied to a real working fuel cell. Therefore, a clear comprehension of its effectiveness in terms of relevant parameters such as time and space resolution, sensitivity, and reproducibility has not yet been achieved. In this paper, all these aspects are discussed and clarified. In order to focus on the method overall effectiveness and on the extent of possible improvements, a basic experimental configuration for both the electrochemical station and the X-ray equipment has been set. The method is described with particular attention to its operating principle and to the evaluation of the errors introduced in data assessment. Finally, applications to some model experiments, in particular working states of the device, are provided and the obtained results are discussed. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Triblock copolymer anion exchange membranes bearing alkyl-tethered cycloaliphatic quaternary ammonium-head-groups for fuel cells

    Science.gov (United States)

    Lin, Chen Xiao; Wang, Xiu Qin; Li, Ling; Liu, Fang Hua; Zhang, Qiu Gen; Zhu, Ai Mei; Liu, Qing Lin

    2017-10-01

    To explore highly conductive and alkaline stable anion exchange membrane (AEM) materials, triblock copolymers bearing alkyl-tethered cycloaliphatic quaternary ammonium-head-groups are prepared via nucleophilic substitution, Friedel-Crafts acylation, ketone reduction and Menshutkin reaction. The designed triblock copolymers composed of quaternized poly(phenylene oxide) segments and poly(ether sulfone) segments are responsible for the microphase separated morphology and well-connected ion domains, as confirmed by transmission electron microscopy. The highest conductivity, up to 105.1 mS cm-1 at 80 °C is achieved for the AEM with ionic exchange capacity (IEC) of 1.81 meq g-1. Furthermore, the AEMs show robust alkaline stability due to the alkyl-tethered cation-head-groups structure. High retention of hydroxide conductivity (88.9%) and IEC (91.2%) is observed for the AEMs via degradation test in a 1 M aqueous KOH solution at 80 °C for 480 h. Based on the AEM with high conductivity, a H2/O2 fuel cell achieves a peak power density of 176.5 mW cm-2 (80 °C) at a current density of 500 mA cm-2.

  5. Enthalpy analysis and Heat Exchanger Sizing of an Air-cooled Proton Exchange Membrane Fuel Cell System

    DEFF Research Database (Denmark)

    Gao, Xin; Berning, Torsten; Kær, Søren Knudsen

    the warmer exhaust air is used to pre-heat and also humidify the incoming colder and dryer air stream using an enthalpy wheel. It is important to thermodynamically understand such a fuel cell system, and in this work the enthalpy streams and the humidity stream are followed throughout the fuel cell system...... simulations have been carried out to better understand the distribution of the reactant air over the fuel cell stack and the resulting temperature distribution across the stack. These results suggest that the humidifying function of the current enthalpy wheel is negligible and a smaller enthalpy wheel...

  6. Anion-exchange membranes derived from quaternized polysulfone and exfoliated layered double hydroxide for fuel cells

    Science.gov (United States)

    Liu, Wan; Liang, Na; Peng, Pai; Qu, Rong; Chen, Dongzhi; Zhang, Hongwei

    2017-02-01

    Layered double hydroxides (LDH) are prepared by controlling urea assisted homogeneous precipitation conditions. Morphology and crystallinity of LDHs are confirmed by X-ray diffraction and scanning electron microscope. After LDHs are incorporated into quaternized polysulfone membranes, transmission electron microscope is used to observe the exfoliated morphology of LDH sheets in the membranes. The properties of the nanocomposite membranes, including water uptake, swelling ratio, mechanical property and ionic conductivity are investigated. The nanocomposite membrane containing 5% LDH sheets shows more balanced performances, exhibiting an ionic conductivity of 2.36×10-2 S cm-1 at 60 °C.

  7. Development of a Space-Rated Proton Exchange Membrane Fuel Cell

    Science.gov (United States)

    Hoffman, William C., III; Vasquez, Arturo; Lazaroff, Scott M.; Downey, Michael G.

    1999-01-01

    Power systems for human spacecraft have historically included fuel cells due to the superior energy density they offer over battery systems depending on mission length and power consumption. As space exploration focuses on the evolution of reusable spacecraft and also considers planetary exploration power system requirements, fuel cells continue to be a factor in the potential system solutions.

  8. Proton Exchange Membrane (PEM) Fuel Cell Status and Remaining Challenges for Manned Space-Flight Applications

    Science.gov (United States)

    Reaves, Will F.; Hoberecht, Mark A.

    2003-01-01

    The Fuel Cell has been used for manned space flight since the Gemini program. Its power output and water production capability over long durations for the mass and volume are critical for manned space-flight requirements. The alkaline fuel cell used on the Shuttle, while very reliable and capable for it s application, has operational sensitivities, limited life, and an expensive recycle cost. The PEM fuel cell offers many potential improvements in those areas. NASA Glenn Research Center is currently leading a PEM fuel cell development and test program intended to move the technology closer to the point required for manned space-flight consideration. This paper will address the advantages of PEM fuel cell technology and its potential for future space flight as compared to existing alkaline fuel cells. It will also cover the technical hurdles that must be overcome. In addition, a description of the NASA PEM fuel cell development program will be presented, and the current status of this effort discussed. The effort is a combination of stack and ancillary component hardware development, culminating in breadboard and engineering model unit assembly and test. Finally, a detailed roadmap for proceeding fiom engineering model hardware to qualification and flight hardware will be proposed. Innovative test engineering and potential payload manifesting may be required to actually validate/certify a PEM fuel cell for manned space flight.

  9. Covalent-ionically cross-linked polyetheretherketone proton exchange membrane for direct methanol fuel cell

    CSIR Research Space (South Africa)

    Luo, H

    2010-08-01

    Full Text Available cross-linked PEEK-WC membrane, this covalent-ionically cross-linked PEEK-WC membrane exhibits extremely reduced water uptake and methanol permeability, but just slightly sacrificed proton conductivity. The proton conductivity of the covalent...

  10. 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

    cell, and the only possibility to prevent membrane dry-out is to operate at or below 70 °C. The cell is generally better humidified at an elevated pressure, and here it is found that the cathode channels will become flooded when the operating temperature is too low, e.g. 70 °C, while membrane hydration...

  11. Synthesizing 2D MoS2 Nanofins on carbon nanospheres as catalyst support for Proton Exchange Membrane Fuel Cells

    National Research Council Canada - National Science Library

    Hu, Yan; Chua, Daniel H C

    2016-01-01

    ...) 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...

  12. Hybrid ion-exchange membranes for fuel cells and separation processes

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Carretero, F.J.; Compan, V. [Departamento de Termodinamica Aplicada, ETSII, Universidad Politecnica de Valencia, 46020 Valencia (Spain); Riande, E. [Instituto de Ciencia y Tecnologia de Polimeros (CSIC), 28006 Madrid (Spain)

    2007-11-08

    This work reports the preparation and characterization of hybrid membranes cast from dispersions of inorganic fillers in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene solutions. Silica gel, SBA-15 and sepiolite, all of them functionalized with phenylsulfonic acid groups, were used as fillers. For comparative purposes, the performance of composite membranes cast from dispersions of functionalized inorganic fillers in Nafion {sup registered} solutions was investigated. Inspection of the texture of the membranes by using SEM techniques shows that the fillers are better dispersed in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene than in Nafion {sup registered}. The value of the water uptake for the membranes prepared from the former polyelectrolyte is in most cases at least three times that measured for hybrid Nafion {sup registered} membranes. The conductivity of the membranes was measured at 80 C by impedance spectroscopy obtaining values of 3.44, 6.90 and 3.54 S m{sup -1} for the hybrid membranes based on the triblock copolymer containing functionalized silica gel, SBA-15 and sepiolite fillers, respectively. These results compare very favourably with those obtained at 80 C for Nafion {sup registered} hybrid membranes containing silica gel, SBA-15 and sepiolite, all of them fuctionalized with phenylsulfonic acid groups, whose conductivities are, 2.84, 6.75 and 3.31 S m{sup -1}, respectively. Resistance measurements carried out under controlled humidity conditions show that the conductivity of sulfonated triblock copolymer membranes containing functionalized SBA-15 filler undergoes a rather sharp increase when they are conditioned under an atmosphere of 75%, or larger, relative humidity. (author)

  13. Optimal selection of proton exchange membrane fuel cell condition monitoring thresholds

    Science.gov (United States)

    Boškoski, Pavle; Debenjak, Andrej

    2014-12-01

    When commissioning or restarting a system after a maintenance action there is a need to properly tune the decision thresholds of the diagnostic system. Too low or too high thresholds may implicate either missed alarms or false alarm rates. This paper suggests an efficient data-driven approach to optimal setting of decision thresholds for a PEM fuel cell system based solely on data acquired from the system in reference state of health (i.e. under fault free operation). The only design parameter is the desired false alarm rate. Technically, the problem reduces to analytically determining the probability distribution of the fuel cell's complex impedance and its particular components. Employing pseudo-random binary sequence perturbation signals, the distribution of the impedance is estimated through the complex wavelet coefficients of the fuel cell voltage and current. The approach is validated on a PEM fuel cell system subjected to various faults.

  14. Real Time Monitoring of Temperature of a Micro Proton Exchange Membrane Fuel Cell

    Science.gov (United States)

    Lee, Chi-Yuan; Lee, Shuo-Jen; Hu, Yuh-Chung; Shih, Wen-Pin; Fan, Wei-Yuan; Chuang, Chih-Wei

    2009-01-01

    Silicon micro-hole arrays (Si-MHA) were fabricated as a gas diffusion layer (GDL) in a micro fuel cell using the micro-electro-mechanical-systems (MEMS) fabrication technique. The resistance temperature detector (RTD) sensor was integrated with the GDL on a bipolar plate to measure the temperature inside the fuel cell. Experimental results demonstrate that temperature was generally linearly related to resistance and that accuracy and sensitivity were within 0.5 °C and 1.68×10−3/°C, respectively. The best experimental performance was 9.37 mW/cm2 at an H2/O2 dry gas flow rate of 30/30 SCCM. Fuel cell temperature during operation was 27 °C, as measured using thermocouples in contact with the backside of the electrode. Fuel cell operating temperature measured in situ was 30.5 °C. PMID:22573963

  15. Real Time Monitoring of Temperature of a Micro Proton Exchange Membrane Fuel Cell

    Directory of Open Access Journals (Sweden)

    Chih-Wei Chuang

    2009-03-01

    Full Text Available Silicon micro-hole arrays (Si-MHA were fabricated as a gas diffusion layer (GDL in a micro fuel cell using the micro-electro-mechanical-systems (MEMS fabrication technique. The resistance temperature detector (RTD sensor was integrated with the GDL on a bipolar plate to measure the temperature inside the fuel cell. Experimental results demonstrate that temperature was generally linearly related to resistance and that accuracy and sensitivity were within 0.5 °C and 1.68×10-3/°C, respectively. The best experimental performance was 9.37 mW/cm2 at an H2/O2 dry gas flow rate of 30/30 SCCM. Fuel cell temperature during operation was 27 °C, as measured using thermocouples in contact with the backside of the electrode. Fuel cell operating temperature measured in situ was 30.5 °C.

  16. Carbon corrosion of proton exchange membrane fuel cell catalyst layers studied by scanning transmission X-ray microscopy

    Science.gov (United States)

    Hitchcock, Adam P.; Berejnov, Viatcheslav; Lee, Vincent; West, Marcia; Colbow, Vesna; Dutta, Monica; Wessel, Silvia

    2014-11-01

    Scanning Transmission X-ray Microscopy (STXM) at the C 1s, F 1s and S 2p edges has been used to investigate degradation of proton exchange membrane fuel cell (PEM-FC) membrane electrode assemblies (MEA) subjected to accelerated testing protocols. Quantitative chemical maps of the catalyst, carbon support and ionomer in the cathode layer are reported for beginning-of-test (BOT), and end-of-test (EOT) samples for two types of carbon support, low surface area carbon (LSAC) and medium surface area carbon (MSAC), that were exposed to accelerated stress testing with upper potentials (UPL) of 1.0, 1.2, and 1.3 V. The results are compared in order to characterize catalyst layer degradation in terms of the amounts and spatial distributions of these species. Pt agglomeration, Pt migration and corrosion of the carbon support are all visualized, and contribute to differing degrees in these samples. It is found that there is formation of a distinct Pt-in-membrane (PTIM) band for all EOT samples. The cathode thickness shrinks due to loss of the carbon support for all MSAC samples that were exposed to the different upper potentials, but only for the most aggressive testing protocol for the LSAC support. The amount of ionomer per unit volume significantly increases indicating it is being concentrated in the cathode as the carbon corrosion takes place. S 2p spectra and mapping of the cathode catalyst layer indicates there are still sulfonate groups present, even in the most damaged material.

  17. Modeling the dynamic behavior of proton-exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Llapade, Peter O [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Davey, John R [Los Alamos National Laboratory; Borup, Rodney L [Los Alamos National Laboratory; Meyers, Jeremy P [UNIV OF TEXAS-AUSTIN

    2010-01-01

    A two-phase transient model that incorporates the permanent hysteresis observed in the experimentally measured capillary pressure of GDL has been developed. The model provides explanation for the difference in time constant between membrane hydration and dehydration observed in the HFR experiment conducted at LANL. When there is liquid water at the cathode catalyst layer, time constant of the water content in the membrane is closely tied to that of liquid water saturation in the CCL, as the vapor is already saturated. The water content in the membrane will not reach steady state as long as the liquid water flow in the CCL is not at steady state. Also, Increased resistance to proton transport in the membrane is observed when the cell voltage is stepped down to a very low value.

  18. The through-plane thermal conductivity and the contact resistance of the components of the membrane electrode assembly and gas diffusion layer in proton exchange membrane fuel cells

    Science.gov (United States)

    Alhazmi, N.; Ingham, D. B.; Ismail, M. S.; Hughes, K.; Ma, L.; Pourkashanian, M.

    2014-12-01

    The thermal conductivity of the components of the membrane electrode assembly (MEA) and GDL must be accurately estimated in order to better understand the heat transfer processes in the proton exchange membrane (PEM) fuel cells. In this study, an experimental investigation has been performed to measure the through-plane thermal conductivity and the contact resistance for a number of gas diffusion layer (GDL) materials. The sensitivity of these quantities to the temperature, PTFE content and micro porous layer (MPL) coating has been undertaken. In addition, the through-plane thermal conductivity of the membrane has been measured and reported as a function of temperature and water content. Further, the through-plane thermal conductivity of the catalyst layer has been determined as a function of temperature and platinum loading. It has been found that the through-plane thermal conductivity of the components of the MEA decreases when the temperature increases, and the through-plane thermal conductivity of the GDL is significantly lower than its in-plane thermal conductivity.

  19. Proton exchange membrane fuel cell systems engineering at Vickers Shipbuilding and Engineering Limited (VSEL)

    Science.gov (United States)

    Seymour, C. M.

    1992-01-01

    A project, jointly funded by VSEL and CJB Developments Limited, is aimed at the development of complete power generation systems based on PEM fuel cell technology. Potential markets for such systems are seen as being very broadly based, ranging from military land and marine systems through to commercial on-site power generation and transport. From the outset the project was applications driven, the intent being to identify market requirements, in terms of system specifications and to use these to produce development targets. The two companies have based their work on the Ballard PEM stack and have focused their efforts on the development of supporting systems. This benefits all three companies as it allows Ballard to obtain applications information on which to base future research and VSEL/CJBD are able to capitalise on the advanced development of the Ballard stack. Current work is focused on the production of a 20 kW, methanol fuelled, power generation system demonstrator, although work is also in hand to address a wider range of fuels including natural gas. The demonstrator, when complete, will be used to indicate the potential benefits of such systems and to act as a design aid for the applications phase of the project. Preliminary work on this next phase is already in hand, with studies to assess both systems and fuel cell stack design requirements for specific applications and to generate concept designs. Work to date has concentrated on the development of a methanol reformer, suitable for integration into a fuel cell system and on extensive testing and evaluation of the Ballard fuel cell stacks. This testing has covered a wide range of operating parameters, including different fuel and oxidant combinations. The effect of contaminants on the performance and life of the fuel cells is also under evaluation. PEM fuel cells still require a great deal of further development if they are to gain widespread commercial acceptance. A recent study conducted by VSEL in

  20. Epoxy-crosslinked sulfonated poly (phenylene) copolymer proton exchange membranes

    Science.gov (United States)

    Hibbs, Michael; Fujimoto, Cy H.; Norman, Kirsten; Hickner, Michael A.

    2010-10-19

    An epoxy-crosslinked sulfonated poly(phenylene) copolymer composition used as proton exchange membranes, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cell, in electrode casting solutions and electrodes, and in sulfur dioxide electrolyzers. These improved membranes are tougher, have higher temperature capability, and lower SO.sub.2 crossover rates.

  1. Hydrogen-oxygen proton-exchange membrane fuel cells and electrolyzers

    Science.gov (United States)

    Baldwin, R.; Pham, M.; Leonida, A.; Mcelroy, J.; Nalette, T.

    1990-01-01

    A flight experiment is planned for the validation, in a microgravity environment, of several ground-proven simplification features relating to SPE fuel cells and SPE electrolyzers. With a successful experiment, these features can be incorporated into equipment designs for specific extraterrestrial energy storage applications.

  2. Surface area loss mechanisms of Pt3Co nanocatalysts in proton exchange membrane fuel cells

    Science.gov (United States)

    Rasouli, S.; Ortiz Godoy, R. A.; Yang, Z.; Gummalla, M.; Ball, S. C.; Myers, D.; Ferreira, P. J.

    2017-03-01

    Pt3Co catalyst nanoparticles of 4.9 nm size present on the cathode side of a PEMFC membrane-electrode assembly (MEA) were analyzed by transmission electron microscopy after 10 K voltage cycles under different operating conditions. The operating conditions include baseline (0.4-0.95 V, 80° C, 100% Relative Humidity (RH)), high potential (0.4-1.05 V, 80° C, 100% RH), high temperature (0.4-0.95 V, 90° C, 100% RH), and low humidity (0.4-0.95 V, 80° C, 30% RH). Particle growth and particle loss to the membrane is more severe in the high potential sample than in the high temperature and baseline MEAs, while no significant particle growth and particle precipitation in the membrane can be observed in the low humidity sample. Particles with different morphologies were seen in the cathode including: 1-Spherical individual particles resulting from modified electro-chemical Ostwald ripening and 2-aggregated and coalesced particles resulting from either necking of two or more particles or preferential deposition of Pt between particles with consequent bridging. The difference in the composition of these morphologies results in composition variations through the cathode from cathode/diffusion media (DM) to the cathode/membrane interface.

  3. Bipolar plate/diffuser for a proton exchange membrane fuel cell

    Science.gov (United States)

    Besmann, Theodore M.; Burchell, Timothy D.

    2000-01-01

    A combination bipolar plate/diffuser fuel cell component includes an electrically conducting solid material having: a porous region having a porous surface; and a hermetic region, the hermetic region defining at least a portion of at least one coolant channel, the porous region defining at least a portion of at least one reactant channel, the porous region defining a flow field medium for diffusing the reactant to the porous surface.

  4. Decentralized generation of electricity from biomass with proton exchange membrane fuel cell

    Science.gov (United States)

    Toonssen, Richard; Woudstra, Nico; Verkooijen, Adrian H. M.

    Biomass can be applied as the primary source for the production of hydrogen in the future. The biomass is converted in an atmospheric fluidized bed gasification process using steam as the gasifying agent. The producer gas needs further cleaning and processing before the hydrogen can be converted in a fuel cell; it is assumed that the gas cleaning processes are able to meet the requirements for a PEM-FC. The compressed hydrogen is supplied to a hydrogen grid and can be used in small-scale decentralized CHP units. In this study it is assumed that the CHP units are based on low temperature PEM fuel cells. For the evaluation of alternative technologies the whole chain of centralized hydrogen production from biomass up to and including decentralized electricity production in PEM fuel cells is considered. Two models for the production of hydrogen from biomass and three models for the combined production of electricity and heat with PEM fuel cells are built using the computer program Cycle-Tempo. Two different levels of hydrogen purity are considered in this evaluation: 60% and 99.99% pure hydrogen. The purity of the hydrogen affects both the efficiencies of the hydrogen production as well as the PEM-FC systems. The electrical exergy efficiency of the PEM-FC system without additional heat production is calculated to be 27.66% in the case of 60% hydrogen and 29.06% in the case of 99.99% pure hydrogen. The electrical exergy efficiencies of the whole conversion chain appear to be 21.68% and 18.74%, respectively. The high losses during purification of the hydrogen gas result in a higher efficiency for the case with low purity hydrogen. The removal of the last impurities strongly increases the overall exergy losses of the conversion chain.

  5. A noble metal-free proton-exchange membrane fuel cell based on bio-inspired molecular catalysts.

    Science.gov (United States)

    Tran, P D; Morozan, A; Archambault, S; Heidkamp, J; Chenevier, P; Dau, H; Fontecave, M; Martinent, A; Jousselme, B; Artero, V

    2015-03-01

    Hydrogen is a promising energy vector for storing renewable energies: obtained from water-splitting, in electrolysers or photoelectrochemical cells, it can be turned back to electricity on demand in fuel cells (FCs). Proton exchange membrane (PEM) devices with low internal resistance, high compactness and stability are an attractive technology optimized over decades, affording fast start-up times and low operating temperatures. However, they rely on the powerful catalytic properties of noble metals such as platinum, while lower cost, more abundant materials would be needed for economic viability. Replacing these noble metals at both electrodes has long proven to be a difficult task, so far incompatible with PEM technologies. Here we take advantage of newly developed bio-inspired molecular H 2 oxidation catalysts and noble metal-free O 2 -reducing materials, to fabricate a noble metal-free PEMFC, with an 0.74 V open circuit voltage and a 23 μW cm -2 output power under technologically relevant conditions. X-ray absorption spectroscopy measurements confirm that the catalysts are stable and retain their structure during turnover.

  6. Alumina-carbon nanofibers nanocomposites obtained by spark plasma sintering for proton exchange membrane fuel cell bipolar plates

    Energy Technology Data Exchange (ETDEWEB)

    Borrell, A.; Torrecillas, R. [Centro de Investigacion en Nanomateriales y Nanotecnologia (CINN) Consejo Superior de Investigaciones Cientificas, Universidad de Oviedo, Principado de Asturias, Parque Tecnologico de Asturias, Llanera Asturias (Spain); Rocha, V.G.; Fernandez, A. [ITMA Materials Technology, Parque Tecnologico de Asturias, Llanera Asturias (Spain)

    2012-08-15

    There is an increasing demand of multifunctional materials for a wide variety of technological developments. Bipolar plates for proton exchange membrane fuel cells are an example of complex functionality components that must show among other properties high mechanical strength, electrical, and thermal conductivity. The present research explored the possibility of using alumina-carbon nanofibers (CNFs) nanocomposites for this purpose. In this study, it was studied for the first time the whole range of powder compositions in this system. Homogeneous powders mixtures were prepared and subsequently sintered by spark plasma sintering. The materials obtained were thoroughly characterized and compared in terms of properties required to be used as bipolar plates. The control on material microstructure and composition allows designing materials where mechanical or electrical performances are enhanced. A 50/50 vol.% alumina-CNFs composite appears to be a very promising material for this kind of application. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Experimental study on the optimal purge duration of a proton exchange membrane fuel cell with a dead-ended anode

    Science.gov (United States)

    Lin, Yu-Fen; Chen, Yong-Song

    2017-02-01

    When a proton exchange membrane fuel cell (PEMFC) is operated with a dead-ended anode, impurities gradually accumulate within the anode, resulting in a performance drop. An anode purge is thereby ultimately required to remove impurities within the anode. A purge strategy comprises purge interval (valve closed) and purge duration (valve is open). A short purge interval causes frequent and unnecessary activation of the valve, whereas a long purge interval leads to excessive impurity accumulation. A short purge duration causes an incomplete performance recovery, whereas a long purge duration results in low hydrogen utilization. In this study, a series of experimental trials was conducted to simultaneously measure the hydrogen supply rate and power generation of a PEMFC at a frequency of 50 Hz for various operating current density levels and purge durations. The effect of purge duration on the cell's energy efficiency was subsequently analyzed and discussed. The results showed that the optimal purge duration for the PEMFC was approximately 0.2 s. Based on the results of this study, a methodical process for determining optimal purge durations was ultimately proposed for widespread application. Purging approximately one-fourth of anode gas can obtain optimal energy efficiency for a PEMFC with a dead-ended anode.

  8. Influence of the cathode architecture in the frequency response of self-breathing proton exchange membrane fuel cells

    Science.gov (United States)

    Ferreira-Aparicio, P.; Chaparro, A. M.

    2014-12-01

    Self-breathing proton exchange membrane fuel cells are apparently simple devices, but efficient water management is critical for their performance. The cathode configuration should guarantee balanced rates between O2 accessibility from the circumventing air and H2O removal, and a good electric contact between catalyst layers and current collectors at the same time. By applying progressive modifications to the initial concept of a conventional PEMFC, the effect of the cathode architecture on cell performance has been analyzed. Frequency response analyses of the cell during steady-state potentiostatic stepping have yielded relevant information regarding limitations originated by the cathode impedance under high current load conditions. The primitive cell design has been optimized for self-breathing operation by means of this diagnostic tool. The thickness of the perforated plate in the cathode has been found to be one of the main factors contributing to limit oxygen accessibility when a high current load is demanded. Adequate cathode architecture is critical for reducing mass transport limitations in the catalytic layer and enhancing performance under self-breathing conditions.

  9. Hybrid approach combining multiple characterization techniques and simulations for microstructural analysis of proton exchange membrane fuel cell electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Cetinbas, Firat C.; Ahluwalia, Rajesh K.; Kariuki, Nancy; De Andrade, Vincent; Fongalland, Dash; Smith, Linda; Sharman, Jonathan; Ferreira, Paulo; Rasouli, Somaye; Myers, Deborah J.

    2017-03-01

    The cost and performance of proton exchange membrane fuel cells strongly depend on the cathode electrode due to usage of expensive platinum (Pt) group metal catalyst and sluggish reaction kinetics. Development of low Pt content high performance cathodes requires comprehensive understanding of the electrode microstructure. In this study, a new approach is presented to characterize the detailed cathode electrode microstructure from nm to μm length scales by combining information from different experimental techniques. In this context, nano-scale X-ray computed tomography (nano-CT) is performed to extract the secondary pore space of the electrode. Transmission electron microscopy (TEM) is employed to determine primary C particle and Pt particle size distributions. X-ray scattering, with its ability to provide size distributions of orders of magnitude more particles than TEM, is used to confirm the TEM-determined size distributions. The number of primary pores that cannot be resolved by nano-CT is approximated using mercury intrusion porosimetry. An algorithm is developed to incorporate all these experimental data in one geometric representation. Upon validation of pore size distribution against gas adsorption and mercury intrusion porosimetry data, reconstructed ionomer size distribution is reported. In addition, transport related characteristics and effective properties are computed by performing simulations on the hybrid microstructure.

  10. Impact of operating conditions on the acetylene contamination in the cathode of proton exchange membrane fuel cells

    Science.gov (United States)

    Zhai, Yunfeng; St-Pierre, Jean

    2017-12-01

    Realistically, proton exchange membrane fuel cells (PEMFCs) are operated under varying operating conditions that potentially impact the acetylene contamination reactions. In this paper, the effects of the cell operating conditions on the acetylene contamination in PEMFCs are investigated under different current densities and temperatures with different acetylene concentrations in the cathode. Electrochemical impedance spectroscopy is applied during the constant-current operation to analyze the impacts of the operating conditions on the acetylene electrochemical reactions. The experimental results indicate that higher acetylene concentrations, higher current densities and lower cell temperatures decrease the cell performance more. In particular, cathode poisoning becomes more severe at medium cell current densities. The cell cathode potentials at such current densities are not sufficient to completely oxidize the intermediate or sufficiently low to completely reduce the adsorbed acetylene. Based on these investigations, the possible condition-dependent limitations of the acetylene concentration and cell operating voltage are proposed for insight into the acetylene contamination mitigation stratagem. Regarding the barrier conditions, the acetylene reactions change abruptly, and adjusting the cell operation parameters to change the acetylene adsorbate and intermediate accumulation conditions to induce complete oxidation or reduction conditions may mitigate the severe acetylene contamination effects on PEMFCs.

  11. Development of an Internal Real-Time Wireless Diagnostic Tool for a Proton Exchange Membrane Fuel Cell

    Science.gov (United States)

    Lee, Chi-Yuan; Chen, Chia-Hung; Tsai, Chao-Hsuan; Wang, Yu-Syuan

    2018-01-01

    To prolong the operating time of unmanned aerial vehicles which use proton exchange membrane fuel cells (PEMFC), the performance of PEMFC is the key. However, a long-term operation can make the Pt particles of the catalyst layer and the pollutants in the feedstock gas bond together (e.g., CO), so that the catalyst loses reaction activity. The performance decay and aging of PEMFC will be influenced by operating conditions, temperature, flow and CO concentration. Therefore, this study proposes the development of an internal real-time wireless diagnostic tool for PEMFC, and uses micro-electro-mechanical systems (MEMS) technology to develop a wireless and thin (<50 μm) flexible integrated (temperature, flow and CO) microsensor. The technical advantages are (1) compactness and three wireless measurement functions; (2) elastic measurement position and accurate embedding; (3) high accuracy and sensitivity and quick response; (4) real-time wireless monitoring of dynamic performance of PEMFC; (5) customized design and development. The flexible integrated microsensor is embedded in the PEMFC, three important physical quantities in the PEMFC, which are the temperature, flow and CO, can be measured simultaneously and instantly, so as to obtain the authentic and complete reaction in the PEMFC to enhance the performance of PEMFC and to prolong the service life. PMID:29342832

  12. Effects of propylene, methyl methacrylate and isopropanol poisoning on spatial performance of a proton exchange membrane fuel cell

    Science.gov (United States)

    Reshetenko, Tatyana V.; St-Pierre, Jean

    2018-02-01

    This paper studies the effects of propylene, methyl methacrylate (MMA) and isopropanol (IPA) in air on the spatial performance of proton exchange membrane fuel cells (PEMFCs). The introduction of 100 ppm C3H6 into the oxidant stream resulted in a performance decrease of 130 mV at 1.0 A cm-2, whereas 20 ppm MMA caused a voltage loss of 80 mV. A moderate performance decline of 60 mV was detected in the presence of 5.3ṡ103 ppm IPA in air. Spatial electrochemical impedance spectroscopy (EIS) data showed an increase in charge and mass transfer resistances under exposure to C3H6 and MMA, although IPA did not affect the impedance. The observed PEMFC performances, local current redistributions and EIS data can be explained by the adsorption of contaminants on the Pt surface, their subsequent transformations, and their impacts on the electrochemical surface area and oxygen reduction mechanism. It was assumed that the studied contaminants were oxidized mainly to CO2 via electrochemical and chemical pathways under the operating conditions and at the cathode potential. Self-recovery of PEMFC performance was observed for each contaminant after halting its introduction into the air. Possible contaminant oxidation/reduction mechanisms and their correlations with spatial performance and EIS are presented and discussed.

  13. Gas diffusion electrode based on electrospun Pani/CNF nanofibers hybrid for proton exchange membrane fuel cells (PEMFC) applications

    Science.gov (United States)

    Hezarjaribi, M.; Jahanshahi, M.; Rahimpour, A.; Yaldagard, M.

    2014-03-01

    A novel hybrid system has been investigated based on polyaniline/carbon nanofiber (Pani/CNF) electrospun nanofibers for modification of gas diffusion electrode (GDE) in proton exchange membrane fuel cells (PEMFC). Pani/CNF hybrid nanofibers were synthesized directly on carbon paper by electrospinning method. For preparation of catalyst ink, 20 wt.% Pt/C electrocatalyst with a platinum loading of 0.4 mg cm-2 was prepared by polyol technique. SEM studies applied for morphological study of the modified GDE with hybrid nanofibers. This technique indicated that the electrospun nanofibers had a diameter of roughly 100 nm. XRD patterns also showed that the average size of Pt nanoparticles was about 2 nm. Subsequently, comparison of the hybrid electrode electrochemical behavior and 20 wt.% Pt/C commercial one was studied by cyclic voltammetry experiment. The electrochemical data indicated that the hybrid electrode exhibited higher current density (about 15 mA cm-2) and ESA (160 m2 gr-1) than commercial Pt/C with amount of about 10 mA cm-2 and 114 m2 gr-1, respectively. The results herein demonstrate that Pani/CNF nanofibers can be used as a good alternative electrode material for PEMFCs.

  14. Gas diffusion electrode based on electrospun Pani/CNF nanofibers hybrid for proton exchange membrane fuel cells (PEMFC) applications

    Energy Technology Data Exchange (ETDEWEB)

    Hezarjaribi, M.; Jahanshahi, M., E-mail: mjahan@nit.ac.ir; Rahimpour, A.; Yaldagard, M.

    2014-03-01

    A novel hybrid system has been investigated based on polyaniline/carbon nanofiber (Pani/CNF) electrospun nanofibers for modification of gas diffusion electrode (GDE) in proton exchange membrane fuel cells (PEMFC). Pani/CNF hybrid nanofibers were synthesized directly on carbon paper by electrospinning method. For preparation of catalyst ink, 20 wt.% Pt/C electrocatalyst with a platinum loading of 0.4 mg cm{sup −2} was prepared by polyol technique. SEM studies applied for morphological study of the modified GDE with hybrid nanofibers. This technique indicated that the electrospun nanofibers had a diameter of roughly 100 nm. XRD patterns also showed that the average size of Pt nanoparticles was about 2 nm. Subsequently, comparison of the hybrid electrode electrochemical behavior and 20 wt.% Pt/C commercial one was studied by cyclic voltammetry experiment. The electrochemical data indicated that the hybrid electrode exhibited higher current density (about 15 mA cm{sup −2}) and ESA (160 m{sup 2} gr{sup −1}) than commercial Pt/C with amount of about 10 mA cm{sup −2} and 114 m{sup 2} gr{sup −1}, respectively. The results herein demonstrate that Pani/CNF nanofibers can be used as a good alternative electrode material for PEMFCs.

  15. Development of an Internal Real-Time Wireless Diagnostic Tool for a Proton Exchange Membrane Fuel Cell

    Directory of Open Access Journals (Sweden)

    Chi-Yuan Lee

    2018-01-01

    Full Text Available To prolong the operating time of unmanned aerial vehicles which use proton exchange membrane fuel cells (PEMFC, the performance of PEMFC is the key. However, a long-term operation can make the Pt particles of the catalyst layer and the pollutants in the feedstock gas bond together (e.g., CO, so that the catalyst loses reaction activity. The performance decay and aging of PEMFC will be influenced by operating conditions, temperature, flow and CO concentration. Therefore, this study proposes the development of an internal real-time wireless diagnostic tool for PEMFC, and uses micro-electro-mechanical systems (MEMS technology to develop a wireless and thin (<50 μm flexible integrated (temperature, flow and CO microsensor. The technical advantages are (1 compactness and three wireless measurement functions; (2 elastic measurement position and accurate embedding; (3 high accuracy and sensitivity and quick response; (4 real-time wireless monitoring of dynamic performance of PEMFC; (5 customized design and development. The flexible integrated microsensor is embedded in the PEMFC, three important physical quantities in the PEMFC, which are the temperature, flow and CO, can be measured simultaneously and instantly, so as to obtain the authentic and complete reaction in the PEMFC to enhance the performance of PEMFC and to prolong the service life.

  16. A solution-phase synthesis method to highly active Pt-Co/C electrocatalysts for proton exchange membrane fuel cell

    Science.gov (United States)

    Li, Wenzhen; Chen, Zhongwei; Xu, Lianbin; Yan, Yushan

    A solution-phase synthesis method was studied to prepare carbon supported Pt-Co alloy catalysts. The organic precursors of Pt acetylacetonate and Co acetylacetonate were reduced in a high boiling point solvent of octyl ether in the presence of oleic acid (OAc) and oleylamine (OAm) to produce fine Pt-Co nanoparticles, which were subsequently deposited on carbon support to obtain Pt-Co/C catalysts. Thermogravimetric analysis suggests that the stabilizers (OAc and OAm) can be removed by copious ethanol washing and subsequent moderate temperature heat-treatment (250 °C, under Argon atmosphere). X-ray diffraction patterns indicate that the average particle size is around 2.3 nm, and the lattice parameter is 3.868 Å for the heat-treated Pt-Co/C (40 wt%). Transmission electron microscopy images show very small Pt-Co alloy nanoparticles homogeneously dispersed on the carbon support with a particle size distribution of 2-4 nm for all Pt-Co/C samples. The elements composition of Pt and Co in the final Pt-Co/C catalyst can be well controlled, as evidenced by inductively coupled plasma atomic emission spectroscopy and energy dispersive spectroscopy analyses. Proton exchange membrane fuel cell tests show the heat-treated Pt-Co/C cathode catalyst has higher mass activity of oxygen reduction reaction than Pt/C at an operation voltage of 0.9 V, this can be attributed to its smaller particle size and reduced lattice parameter.

  17. Carbon supported Ag nanoparticles as high performance cathode catalyst for H2/O2 anion exchange membrane fuel cell

    Science.gov (United States)

    Xin, Le; Zhang, Zhiyong; Wang, Zhichao; Qi, Ji; Li, Wenzhen

    2013-01-01

    A solution phase-based nanocapsule method was successfully developed to synthesize non-platinum metal catalyst—carbon supported Ag nanoparticles (Ag/C). XRD patterns and TEM image show Ag nanoparticles with a small average size (5.4 nm) and narrow size distribution (2–9 nm) are uniformly dispersed on the carbon black Vulcan XC-72 support. The intrinsic activity and pathway of oxygen reduction reaction (ORR) on the Ag/C and commercial Pt/C were investigated using rotating ring disk electrode (RRDE) tests at room temperature. The results confirmed that the 4-electron pathway of ORR proceeds on small Ag nanoparticles, and showed comparable ORR activities on the self-prepared Ag/C and a commercial Pt/C. A single H2-O2 anion exchange membrane fuel cell (AEMFC) with the Ag/C cathode catalyst exhibited an open circuit potential of 0.98 V and a peak power density of 190 mW/cm2 at 80°C. PMID:24790944

  18. Highly Stable and Active Pt/Nb-TiO2 Carbon-Free Electrocatalyst for Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Shuhui Sun

    2012-01-01

    Full Text Available The current materials used in proton exchange membrane fuel cells (PEMFCs are not sufficiently durable for commercial deployment. One of the major challenges lies in the development of an inexpensive, efficient, and highly durable and active electrocatalyst. Here a new type of carbon-free Pt/Nb-TiO2 electrocatalyst has been reported. Mesoporous Nb-TiO2 hollow spheres were synthesized by the sol-gel method using polystyrene (PS sphere templates. Pt nanoparticles (NPs were then deposited onto mesoporous Nb-TiO2 hollow spheres via a simple wet-chemical route in aqueous solution, without the need for surfactants or potentiostats. The growth densities of Pt NPs on Nb-TiO2 supports could be easily modulated by simply adjusting the experimental parameters. Electrochemical studies of Pt/Nb-TiO2 show much enhanced activity and stability than commercial E-TEK Pt/C catalyst. PtNP/Nb-TiO2 is a promising new cathode catalyst for PEMFC applications.

  19. Application of a self-supporting microporous layer to gas diffusion layers of proton exchange membrane fuel cells

    Science.gov (United States)

    Ito, Hiroshi; Heo, Yun; Ishida, Masayoshi; Nakano, Akihiro; Someya, Satoshi; Munakata, Tetsuo

    2017-02-01

    The intrinsic effect of properties of a self-supporting microporous layer (MPL) on the performance of proton exchange membrane fuel cells (PEMFCs) is identified. First, a self-supporting MPL is fabricated and applied to a gas diffusion layer (GDL) of a PEMFC, when the GDL is either an integrated sample composed of a gas diffusion backing (GDB, i.e., carbon paper) combined with MPL or a sample with only MPL. Cell performance tests reveal that, the same as the MPL fabricated by the coating method, the self-supporting MPL on the GDB improves the cell performance at high current density. Furthermore, the GDL composed only of the MPL (i.e., GDB-free GDL) shows better performance than does the integrated GDB/MPL GDL. These results along with literature data strongly suggest that the low thermal conductivity of MPL induces a high temperature throughout the GDL, and thus vapor diffusion is dominant in the transport of product water through the MPL.

  20. Isothermal ice crystallization kinetics in the gas-diffusion layer of a proton-exchange-membrane fuel cell.

    Science.gov (United States)

    Dursch, T J; Ciontea, M A; Radke, C J; Weber, A Z

    2012-01-17

    Nucleation and growth of ice in the fibrous gas-diffusion layer (GDL) of a proton-exchange membrane fuel cell (PEMFC) are investigated using isothermal differential scanning calorimetry (DSC). Isothermal crystallization rates and pseudo-steady-state nucleation rates are obtained as a function of subcooling from heat-flow and induction-time measurements. Kinetics of ice nucleation and growth are studied at two polytetrafluoroethylene (PTFE) loadings (0 and 10 wt %) in a commercial GDL for temperatures between 240 and 273 K. A nonlinear ice-crystallization rate expression is developed using Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory, in which the heat-transfer-limited growth rate is determined from the moving-boundary Stefan problem. Induction times follow a Poisson distribution and increase upon addition of PTFE, indicating that nucleation occurs more slowly on a hydrophobic fiber than on a hydrophilic fiber. The determined nucleation rates and induction times follow expected trends from classical nucleation theory. A validated rate expression is now available for predicting ice-crystallization kinetics in GDLs. © 2011 American Chemical Society

  1. Dynamic environmental transmission electron microscopy observation of platinum electrode catalyst deactivation in a proton-exchange-membrane fuel cell.

    Science.gov (United States)

    Yoshida, Kenta; Xudong, Zhang; Bright, Alexander N; Saitoh, Koh; Tanaka, Nobuo

    2013-02-15

    Spherical-aberration-corrected environmental transmission electron microscopy (AC-ETEM) was applied to study the catalytic activity of platinum/amorphous carbon electrode catalysts in proton-exchange-membrane fuel cells (PEMFCs). These electrode catalysts were characterized in different atmospheres, such as hydrogen and air, and a conventional high vacuum of 10(-5) Pa. A high-speed charge coupled device camera was used to capture real-time movies to dynamically study the diffusion and reconstruction of nanoparticles with an information transfer down to 0.1 nm, a time resolution below 0.2 s and an acceleration voltage of 300 kV. With such high spatial and time resolution, AC-ETEM permits the visualization of surface-atom behaviour that dominates the coalescence and surface-reconstruction processes of the nanoparticles. To contribute to the development of robust PEMFC platinum/amorphous carbon electrode catalysts, the change in the specific surface area of platinum particles was evaluated in hydrogen and air atmospheres. The deactivation of such catalysts during cycle operation is a serious problem that must be resolved for the practical use of PEMFCs in real vehicles. In this paper, the mechanism for the deactivation of platinum/amorphous carbon electrode catalysts is discussed using the decay rate of the specific surface area of platinum particles, measured first in a vacuum and then in hydrogen and air atmospheres for comparison.

  2. The influence of humidification and temperature differences between inlet gases on water transport through the membrane of a proton exchange membrane fuel cell

    Science.gov (United States)

    Huang, Kuan-Jen; Hwang, Sheng-Jye; Lai, Wei-Hsiang

    2015-06-01

    This paper discusses the effects of humidification and temperature differences of the anode and cathode on water transport in a proton exchange membrane fuel cell. Heaters are used to cause a difference in gas temperature between two electrodes before the gases enter the fuel cell. The results show that when the temperature of the cathode is higher than that of the anode, the electro-osmotic drag is suppressed. In contrast, when the temperature of the anode is higher than that of cathode, it is enhanced. These effects are more significant when the temperature difference between the anode and cathode is greater. The same trends are seen with back diffusion. Three cases are tested, and the results show that the suppression due to the temperature difference occurs even when the relative humidity is low at the hotter side. The water transport tendencies of electro-osmotic drag and back diffusion in different situations can be expressed as dominant percentages calculated by the water masses collected at the anode and cathode. The suppression effect due to the temperature difference is relatively insignificant with regard to back diffusion compared to electro-osmosis, so water tends to accumulate on the anode rather than the cathode side.

  3. Modification of Nafion membrane with biofunctional SiO2 nanofiber for proton exchange membrane fuel cells

    Science.gov (United States)

    Wang, Hang; Li, Xiaojie; Zhuang, Xupin; Cheng, Bowen; Wang, Wei; Kang, Weimin; Shi, Lei; Li, Hongjun

    2017-02-01

    Proton currents are an integral part of the most important energy-converting structures in biology. We prepared a new type of bioinspired Nafion (Bio-Nafion) membrane composited of biofunctional SiO2 (Bio-SiO2) nanofiber and Nafion matrix. SiO2 nanofibers were prepared by electrospinning silica sol prepared from tetraethyl orthosilicate. Meanwhile, Bio-SiO2 nanofibers were synthesized by immobilizing amino acids (cysteine, serine, lysine, and glycine) on SiO2 nanofibers, which acted as efficient proton-conducting pathways that involved numerous H+ transport sites. In our study, the SiO2 nanofibers biofunctionalized with cysteine were further oxidized, and the composite membranes were designated as Nafion-Cys, Nafion-Lys, Nafion-Ser, and Nafion-Gly, respectively. We then investigated the different polar groups (sbnd SO3H, sbnd OH, and sbnd NH2) of the amino acids that contributed to membrane properties of thermal stability, water uptake (WU), dimensional stability, proton conductivity, and methanol permeability. Nafion-Cys exhibited the highest proton conductivity of 0.2424 S/cm (80 °C). Nafion-Gly showed the lowest proton conductivity and WU because glycine contains the least number of hydrophilic groups among the amino acids. Overall, the introduction of Bio-SiO2 nanofiber to composite membranes significantly improved proton conductivity, dimensional stability, and methanol permeability.

  4. Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications. Hydrogen vehicle safety report

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.E. [Directed Technologies, Inc., Arlington, VA (United States)

    1997-05-01

    This report reviews the safety characteristics of hydrogen as an energy carrier for a fuel cell vehicle (FCV), with emphasis on high pressure gaseous hydrogen onboard storage. The authors consider normal operation of the vehicle in addition to refueling, collisions, operation in tunnels, and storage in garages. They identify the most likely risks and failure modes leading to hazardous conditions, and provide potential countermeasures in the vehicle design to prevent or substantially reduce the consequences of each plausible failure mode. They then compare the risks of hydrogen with those of more common motor vehicle fuels including gasoline, propane, and natural gas.

  5. X-ray Photoelectron Spectroscopy Investigation on Electrochemical Degradation of Proton Exchange Membrane Fuel Cell Electrodes

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Dhiman, Rajnish; Skou, Eivind Morten

    2015-01-01

    X-ray photoelectron spectroscopy studies were systematically carried out on the electrodes before and after the electrochemical stress tests in an aqueous electrolyte at 20 °C and 70 °C. The electrodes have different ionomer structures (no ionomer, only ionomer, physically mixed ionomer and hot...... pressed ionomer) but have identical, commercial catalyst and catalyst loading. A significant degree of carbon corrosion, platinum migration and ionomer degradation were observed in the electrodes after the treatment. The degradation of the ionomer in the electrode is more severe than that of membrane...

  6. Corrosion resistance characteristics of stamped and hydroformed proton exchange membrane fuel cell metallic bipolar plates

    Energy Technology Data Exchange (ETDEWEB)

    Dundar, F. [NSF I/UCRC Center for Precision Forming (CPF), Virginia Commonwealth University, Richmond, VA (United States); Department of Materials Science and Engineering, Gebze Institute of Technology (Turkey); Dur, Ender; Koc, M. [NSF I/UCRC Center for Precision Forming (CPF), Virginia Commonwealth University, Richmond, VA (United States); Mahabunphachai, S. [NSF I/UCRC Center for Precision Forming (CPF), Virginia Commonwealth University, Richmond, VA (United States); National Metal and Materials Technology Center (MTEC), Pathumthani (Thailand)

    2010-06-01

    Metallic bipolar plates have several advantages over bipolar plates made from graphite and composites due to their high conductivity, low material and production costs. Moreover, thin bipolar plates are possible with metallic alloys, and hence low fuel cell stack volume and mass are. Among existing fabrication methods for metallic bipolar plates, stamping and hydroforming are seen as prominent approaches for mass production scales. In this study, the effects of important process parameters of these manufacturing processes on the corrosion resistance of metallic bipolar plates made of SS304 were investigated. Specifically, the effects of punch speed, pressure rate, stamping force and hydroforming pressure were studied as they were considered to inevitably affect the bipolar plate micro-channel dimensions, surface topography, and hence the corrosion resistance. Corrosion resistance under real fuel cell conditions was examined using both potentiodynamic and potentiostatic experiments. The majority of the results exhibited a reduction in the corrosion resistance for both stamped and hydroformed plates when compared with non-deformed blank plates of SS304. In addition, it was observed that there exist an optimal process window for punch speed in stamping and the pressure rate in hydroforming to achieve improved corrosion resistance at a faster production rate. (author)

  7. Lithium polymer batteries and proton exchange membrane fuel cells as energy sources in hydrogen electric vehicles

    Science.gov (United States)

    Corbo, P.; Migliardini, F.; Veneri, O.

    This paper deals with the application of lithium ion polymer batteries as electric energy storage systems for hydrogen fuel cell power trains. The experimental study was firstly effected in steady state conditions, to evidence the basic features of these systems in view of their application in the automotive field, in particular charge-discharge experiments were carried at different rates (varying the current between 8 and 100 A). A comparison with conventional lead acid batteries evidenced the superior features of lithium systems in terms of both higher discharge rate capability and minor resistance in charge mode. Dynamic experiments were carried out on the overall power train equipped with PEM fuel cell stack (2 kW) and lithium batteries (47.5 V, 40 Ah) on the European R47 driving cycle. The usage of lithium ion polymer batteries permitted to follow the high dynamic requirement of this cycle in hard hybrid configuration, with a hydrogen consumption reduction of about 6% with respect to the same power train equipped with lead acid batteries.

  8. Degradation modeling of high temperature proton exchange membrane fuel cells using dual time scale simulation

    Science.gov (United States)

    Pohl, E.; Maximini, M.; Bauschulte, A.; vom Schloß, J.; Hermanns, R. T. E.

    2015-02-01

    HT-PEM fuel cells suffer from performance losses due to degradation effects. Therefore, the durability of HT-PEM is currently an important factor of research and development. In this paper a novel approach is presented for an integrated short term and long term simulation of HT-PEM accelerated lifetime testing. The physical phenomena of short term and long term effects are commonly modeled separately due to the different time scales. However, in accelerated lifetime testing, long term degradation effects have a crucial impact on the short term dynamics. Our approach addresses this problem by applying a novel method for dual time scale simulation. A transient system simulation is performed for an open voltage cycle test on a HT-PEM fuel cell for a physical time of 35 days. The analysis describes the system dynamics by numerical electrochemical impedance spectroscopy. Furthermore, a performance assessment is performed in order to demonstrate the efficiency of the approach. The presented approach reduces the simulation time by approximately 73% compared to conventional simulation approach without losing too much accuracy. The approach promises a comprehensive perspective considering short term dynamic behavior and long term degradation effects.

  9. Applying hot-wire anemometry to directly measure the water balance in a proton exchange membrane fuel cell for a pre-humidified hydrogen stream

    DEFF Research Database (Denmark)

    Berning, Torsten; Shakhshir, Saher Al

    2016-01-01

    In a recent publication it has been shown how the water balance in a proton exchange membrane fuel cell can be determined employing hot wire anemometry. The hot wire sensor has to be placed into the anode outlet pipe of the operating fuel cell, and the voltage signal E that is read from the sensor....... Finally, it will be shown how previously developed dew point diagrams for the anode side in a fuel cell can be corrected for a humidified hydrogen inlet stream....... has to be divided by a pre-determined voltage signal E0 that has been obtained for a stream of dry hydrogen where the molar flow rate corresponds to a total current I of the fuel cell stack and a stoichiometric flow ratio, ξ. Because the last two properties are usually continuously known in fuel cell...

  10. A COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF AIR FLOW THROUGH A TELECOM BACK-UP UNIT POWERED BY AN AIR-COOLED PROTON EXCHANGE MEMBRANE FUEL CELL

    DEFF Research Database (Denmark)

    Gao, Xin; Berning, Torsten; Kær, Søren Knudsen

    2016-01-01

    commercial telecom back-up system produced by Dantherm Power A/S, Denmark. The analysis is carried out with the commercial CFD solver Fluent (ANSYS Inc.). The fuel cell stack is modeled as a porous medium to accurately match the pressure drop, and it includes a heat source to account for the product heat......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 heat....... This product heat has to be effectively removed from the fuel cell, and while automotive fuel cells are usually liquid-cooled using a secondary coolant loop similar to the internal combustion engines, stationary fuel cell systems as they are used for telecom back-up applications often rely on excessive air fed...

  11. Demonstrating hydrogen production from ammonia using lithium imide - Powering a small proton exchange membrane fuel cell

    Science.gov (United States)

    Hunter, Hazel M. A.; Makepeace, Joshua W.; Wood, Thomas J.; Mylius, O. Simon; Kibble, Mark G.; Nutter, Jamie B.; Jones, Martin O.; David, William I. F.

    2016-10-01

    Accessing the intrinsic hydrogen content within ammonia, NH3, has the potential to play a very significant role in the future of a CO2-free sustainable energy supply. Inexpensive light metal imides and amides are effective at decomposing ammonia to hydrogen and nitrogen (2NH3 → 3H2 + N2), at modest temperatures, and thus represent a low-cost approach to on-demand hydrogen production. Building upon this discovery, this paper describes the integration of an ammonia cracking unit with a post-reactor gas purification system and a small-scale PEM fuel cell to create a first bench-top demonstrator for the production of hydrogen using light metal imides.

  12. Existence of the phase drainage diagram in proton exchange membrane fuel cell fibrous diffusion media

    Science.gov (United States)

    Medici, E. F.; Allen, J. S.

    It is well established that drainage in porous media can be characterized by two nondimensional numbers: the capillary number, Ca, and the viscosity ratio, M. Both quantities are useful to distinguish which force (viscous or capillary) is governing the fluid displacement behavior. This information is summarized in the Ca- M phase diagram. The Ca- M phase diagram is strongly dependent upon fluid properties and the porous medium morphology and wettability. Experimental evidence suggests that the morphology of the porous medium has an important role in the behavior in the fluid displacement. In this work, Ca- M phase diagram of fuel cell diffusion media layer (DM) is explored using a pseudo-Hele-Shaw experimental setup. This phase diagram will be explored together with the characteristic pressure curves of each displacement type. This Ca- M phase diagram will provide a fundamental resource for understanding the dynamics of the diffusion process and transport characteristics taking place inside of the DM as well as a characterization method for DMs.

  13. Perfluoropolyether-functionalized gas diffusion layers for proton exchange membrane fuel cells

    Science.gov (United States)

    Gola, Massimo; Sansotera, Maurizio; Navarrini, Walter; Bianchi, Claudia L.; Gallo Stampino, Paola; Latorrata, Saverio; Dotelli, Giovanni

    2014-07-01

    Linear perfluoropolyether (PFPE) peroxide was used to confer superhydrophobic surface properties to gas diffusion layer (GDL) by means of direct functionalization of a GDL based on carbon cloth (CC) material. The thermal decomposition of a linear PFPE peroxide produces linear PFPE radicals that covalently bond the unsaturated moieties on the surface. Perfluorinated radicals are directly and covalently bound to the carbonaceous structure of the CC without any spacer that could decrease both thermal and chemical stability of the GDL. The obtained CC hydrophobicity exceeded the superhydrophobicity threshold and was enduringly stable. The relationship between the linkage of fluorinated chains and the variations of surface chemical-physical properties were studied combining X-ray photoelectron spectroscopy (XPS), resistivity measurements, scanning electron microscopy (SEM) and contact angle measurements. Despite the excellent insulating properties of the PFPE polymer, the functionalized carbonaceous materials substantially retained their conductive properties. The PFPE-modified GDLs were tested in a single fuel cell at the lab scale. The cell tests were run at two temperatures (60 °C and 80 °C) with a relative humidity (RH) of hydrogen and air feeding gases equal to 80/100% and 60/100%, respectively.

  14. Development of gas diffusion layer using water based carbon slurry for proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Lin, J.F.; Liu, X.; Adame, A.; Villacorta, R. [Fuel Cell Research Laboratory, Engineering Technology Department, Arizona State University, Mesa, AZ 85212 (United States); Wertz, J. [Hollingsworth and Vose Co., A.K. Nicholson Research Lab, 219 Townsend Road, West Groton, MA 01472 (United States); Ahmad, R.; Thommes, M. [Quantachrome Instruments, 1900 Corporate Drive, Boynton Beach, FL 33426 (United States); Kannan, A.M., E-mail: amk@asu.ed [Fuel Cell Research Laboratory, Engineering Technology Department, Arizona State University, Mesa, AZ 85212 (United States)

    2011-01-01

    The micro-porous layer of gas diffusion layers (GDLs) was fabricated with the carbon slurry dispersed in water containing sodium dodecyl sulfate (SDS), by wire rod coating process. The aqueous carbon slurry with micelle-encapsulation was highly consistent and stable without losing any homogeneity even after adding polytetrafluoroethylene (PTFE) binder for hundreds of hours. The surface morphology, contact angle and pore size distribution of the GDLs were examined using SEM, Goniometer and Hg Porosimeter, respectively. GDLs fabricated with various SDS concentrations were assembled into MEAs and evaluated in a single cell PEMFC under diverse operating relative humidity (RH) conditions using H{sub 2}/O{sub 2} and H{sub 2}/air as reactants. The peak power density of the single cell using the GDLs with optimum SDS concentration was 1400 and 500 mW cm{sup -2} with H{sub 2}/O{sub 2} and H{sub 2}/air at 90% RH, respectively. GDLs were also fabricated with isopropyl alcohol (IPA) based carbon slurry for fuel cell performance comparison. It was found that the composition of the carbon slurry, specifically SDS concentration played a critical role in controlling the pore diameter as well as the corresponding pore volumes of the GDLs.

  15. Research and development of proton-exchange membrane (PEM) fuel cell system for transportation applications. Phase I final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    Objective during Phase I was to develop a methanol-fueled 10-kW fuel cell power source and evaluate its feasibility for transportation applications. This report documents research on component (fuel cell stack, fuel processor, power source ancillaries and system sensors) development and the 10-kW power source system integration and test. The conceptual design study for a PEM fuel cell powered vehicle was documented in an earlier report (DOE/CH/10435-01) and is summarized herein. Major achievements in the program include development of advanced membrane and thin-film low Pt-loaded electrode assemblies that in reference cell testing with reformate-air reactants yielded performance exceeding the program target (0.7 V at 1000 amps/ft{sup 2}); identification of oxidation catalysts and operating conditions that routinely result in very low CO levels ({le} 10 ppm) in the fuel processor reformate, thus avoiding degradation of the fuel cell stack performance; and successful integrated operation of a 10-kW fuel cell stack on reformate from the fuel processor.

  16. Fuel cell membrane humidification

    Science.gov (United States)

    Wilson, Mahlon S.

    1999-01-01

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

  17. Addition of sulfonated silicon dioxide on an anode catalyst layer to improve the performance of a self-humidifying proton exchange membrane fuel cell

    Science.gov (United States)

    Lin, Chien-Liang; Hsu, Shih-Chieh; Ho, Wei-Yu

    2016-03-01

    Sulfonated SiO2 was added on an anode catalyst layer to manufacture a hygroscopic electrode for self-humidifying proton exchange membrane fuel cells (PEMFCs). The inherent humidity of a proton exchange membrane (PEM) determines the electrical performance of PEMFCs. To maintain the high moisture content of the PEM, self-humidifying PEMFCs can use the water produced by the fuel cell reaction and, thus, do not require external humidification. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and water contact angle measurement tests were performed to characterize the structures and properties of sulfonated SiO2 and the related electrodes, and the electric current and voltage (I-V) performance curve tests for the fuel cells were conducted under differing gas humidification conditions. When 0.01mg/cm2 of sulfonated SiO2 was added, the electrical performance of the fuel cells (50∘C) increased 29% and 59% when the fuel cell reaction gases were humidified at 70∘C and 50∘C, respectively.

  18. Surface composition of magnetron sputtered Pt-Co thin film catalyst for proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Vorokhta, Mykhailo, E-mail: vorohtam@gmail.com [Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Khalakhan, Ivan; Václavů, Michal [Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Kovács, Gábor; Kozlov, Sergey M. [Departament de Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/ Martí i Franquès 1, 08028 Barcelona (Spain); Kúš, Peter; Skála, Tomáš; Tsud, Natalia; Lavková, Jaroslava [Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Potin, Valerie [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université Bourgogne, 9 Av. A. Savary, BP 47870, F-21078 Dijon Cedex (France); and others

    2016-03-01

    Graphical abstract: - Highlights: • Nanostructured Pt-Co thin catalyst films were grown on carbon by magnetron sputtering. • The surface composition of the nanostructured Pt-Co films was investigated by surface analysis techniques. • We carried out modeling of Pt-Co nanoalloys by computational methods. • Both experiment and modeling based on density functional theory showed that the surface of Pt-Co nanoparticles is almost exclusively composed of Pt atoms. - Abstract: Recently we have tested a magnetron sputtered Pt-Co catalyst in a hydrogen-fed proton exchange membrane fuel cell and showed its high catalytic activity for the oxygen reduction reaction. Here we present further investigation of the magnetron sputtered Pt-Co thin film catalyst by both experimental and theoretical methods. Scanning electron microscopy and transmission electron microscopy experiments confirmed the nanostructured character of the catalyst. The surface composition of as-deposited and annealed at 773 K Pt-Co films was investigated by surface analysis techniques, such as synchrotron radiation photoelectron spectroscopy and X-ray photoelectron spectroscopy. Modeling based on density functional theory showed that the surface of 6 nm large 1:1 Pt-Co nanoparticles is almost exclusively composed of Pt atoms (>90%) at typical operation conditions and the Co content does not exceed 20% at 773 K, in agreement with the experimental characterization of such films annealed in vacuum. According to experiment, the density of valence states of surface atoms in Pt-Co nanostructures is shifted by 0.3 eV to higher energies, which can be associated with their higher activity in the oxygen reduction reaction. The changes in electronic structure caused by alloying are also reflected in the measured Pt 4f, Co 3p and Co 2p photoelectron peak binding energies.

  19. Application of proton exchange membrane fuel cells for the monitoring and direct usage of biohydrogen produced by Chlamydomonas reinhardtii

    Science.gov (United States)

    Oncel, S.; Vardar-Sukan, F.

    Photo-biologically produced hydrogen by Chlamydomonas reinhardtii is integrated with a proton exchange (PEM) fuel cell for online electricity generation. To investigate the fuel cell efficiency, the effect of hydrogen production on the open circuit fuel cell voltage is monitored during 27 days of batch culture. Values of volumetric hydrogen production, monitored by the help of the calibrated water columns, are related with the open circuit voltage changes of the fuel cell. From the analysis of this relation a dead end configuration is selected to use the fuel cell in its best potential. After the open circuit experiments external loads are tested for their effects on the fuel cell voltage and current generation. According to the results two external loads are selected for the direct usage of the fuel cell incorporating with the photobioreactors (PBR). Experiments with the PEM fuel cell generate a current density of 1.81 mA cm -2 for about 50 h with 10 Ω load and 0.23 mA cm -2 for about 80 h with 100 Ω load.

  20. Water permeation through anion exchange membranes

    Science.gov (United States)

    Luo, Xiaoyan; Wright, Andrew; Weissbach, Thomas; Holdcroft, Steven

    2018-01-01

    An understanding of water permeation through solid polymer electrolyte (SPE) membranes is crucial to offset the unbalanced water activity within SPE fuel cells. We examine water permeation through an emerging class of anion exchange membranes, hexamethyl-p-terphenyl poly (dimethylbenzimidazolium) (HMT-PMBI), and compare it against series of membrane thickness for a commercial anion exchange membrane (AEM), Fumapem® FAA-3, and a series of proton exchange membranes, Nafion®. The HMT-PMBI membrane is found to possess higher water permeabilities than Fumapem® FAA-3 and comparable permeability than Nafion (H+). By measuring water permeation through membranes of different thicknesses, we are able to decouple, for the first time, internal and interfacial water permeation resistances through anion exchange membranes. Permeation resistances on liquid/membrane interface is found to be negligible compared to that for vapor/membrane for both series of AEMs. Correspondingly, the resistance of liquid water permeation is found to be one order of magnitude smaller compared to that of vapor water permeation. HMT-PMBI possesses larger effective internal water permeation coefficient than both Fumapem® FAA-3 and Nafion® membranes (60 and 18% larger, respectively). In contrast, the effective interfacial permeation coefficient of HMT-PMBI is found to be similar to Fumapem® (±5%) but smaller than Nafion®(H+) (by 14%).

  1. 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...

  2. Anticorrosion Coating of Carbon Nanotube/Polytetrafluoroethylene Composite Film on the Stainless Steel Bipolar Plate for Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Show

    2013-01-01

    Full Text Available Composite film of carbon nanotube (CNT and polytetrafluoroethylene (PTFE was formed from dispersion fluids of CNT and PTFE. The composite film showed high electrical conductivity in the range of 0.1–13 S/cm and hydrophobic nature. This composite film was applied to stainless steel (SS bipolar plates of the proton exchange membrane fuel cell (PEMFC as anticorrosion film. This coating decreased the contact resistance between the surface of the bipolar plate and the membrane electrode assembly (MEA of the PEMFC. The output power of the fuel cell is increased by 1.6 times because the decrease in the contact resistance decreases the series resistance of the PEMFC. Moreover, the coating of this composite film protects the bipolar plate from the surface corrosion.

  3. Experimental investigation and numerical comparison of the performance of a proton exchange membrane fuel cell at different channel geometry

    Science.gov (United States)

    Khazaee, I.

    2015-08-01

    In this study, the performance of a PEM fuel cell is investigated experimentally and numerically by changing the geometry of the channels. At first an experimental setup is used and three different fuel cells with rectangular, elliptical and triangular serpentine channels are constructed. The active area of each cell is 25 cm2 that its weight is 1,300 g. The material of the gas diffusion layer is carbon clothes, the membrane is nafion 117 and the catalyst layer is a plane with 0.004 g cm-2 platinum. Then a complete three-dimensional model for fuel cell is used to investigate the effect of using this channels geometry on the performance. 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. 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 when the geometry of channel is rectangular the performance of the cell is better than the triangular and elliptical channel.

  4. Multiblock copolymers with highly sulfonated blocks containing di- and tetrasulfonated arylene sulfone segments for proton exchange membrane fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Takamuku, Shogo; Jannasch, Patric [Polymer and Materials Chemistry, Department of Chemistry, Lund University (Sweden)

    2012-01-15

    Multiblock copoly(arylene ether sulfone)s with different block lengths and ionic contents are tailored for durable and proton-conducting electrolyte membranes. Two series of fully aromatic copolymers are prepared by coupling reactions between non-sulfonated hydrophobic precursor blocks and highly sulfonated hydrophilic precursor blocks containing either fully disulfonated diarylsulfone or fully tetrasulfonated tetraaryldisulfone segments. The sulfonic acid groups are exclusively introduced in ortho positions to the sulfone bridges to impede desulfonation reactions and give the blocks ion exchange capacities (IECs) of 4.1 and 4.6 meq. g{sup -1}, respectively. Solvent cast block copolymer membranes show well-connected hydrophilic nanophase domains for proton transport and high decomposition temperatures above 310 C under air. Despite higher IEC values, membranes containing tetrasulfonated tetraaryldisulfone segments display a markedly lower water uptake than the corresponding ones with disulfonated diarylsulfone segments when immersed in water at 100 C, presumably because of the much higher chain stiffness and glass transition temperature of the former segments. The former membranes have proton conductivities in level of a perfluorosulfonic acid membrane (NRE212) under fully humidified conditions. A membrane with an IEC of 1.83 meq. g{sup -1} reaches above 6 mS cm{sup -1} under 30% relative humidity at 80 C, to be compared with 10 mS cm{sup -1} for NRE212 under the same conditions. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Model-Based Control of a Continuous Coating Line for Proton Exchange Membrane Fuel Cell Electrode Assembly

    Directory of Open Access Journals (Sweden)

    Vikram Devaraj

    2015-01-01

    Full Text Available The most expensive component of a fuel cell is the membrane electrode assembly (MEA, which consists of an ionomer membrane coated with catalyst material. Best-performing MEAs are currently fabricated by depositing and drying liquid catalyst ink on the membrane; however, this process is limited to individual preparation by hand due to the membrane’s rapid water absorption that leads to shape deformation and coating defects. A continuous coating line can reduce the cost and time needed to fabricate the MEA, incentivizing the commercialization and widespread adoption of fuel cells. A pilot-scale membrane coating line was designed for such a task and is described in this paper. Accurate process control is necessary to prevent manufacturing defects from occurring in the coating line. A linear-quadratic-Gaussian (LQG controller was developed based on a physics-based model of the coating process to optimally control the temperature and humidity of the drying zones. The process controller was implemented in the pilot-scale coating line proving effective in preventing defects.

  6. Effect of different surface treatments on the stability of stainless steels for use as bipolar plates in low and high temperature proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Richards, J.; Schmidt, K. [Fraunhofer-Institut fuer Chemische Technologie (ICT), Wolfsburg (Germany); Tuebke, J.; Cremers, C. [Fraunhofer-Institut fuer Chemische Technologie (ICT), Pfinztal (Germany)

    2010-07-01

    The stability of different stainless steels against corrosion under simulated low and high temperature proton exchange membrane fuel cell (PEMFC) operating conditions was studied. These investigations showed a moderate corrosion resistance for a couple of steels under LT-PEMFC conditions. However, for the HT-PEMFC conditions all specimens except one exhibit visible corrosion traces. With regards to their corrosion resistance after different surface treatments results show a minor improvement in corrosion resistance after the electro polishing process for most of the tested stainless steel samples. (orig.)

  7. Three-Dimensional Transport Modeling for Proton Exchange Membrane(PEM Fuel Cell with Micro Parallel Flow Field

    Directory of Open Access Journals (Sweden)

    Sang Soon Hwang

    2008-03-01

    Full Text Available Modeling and simulation for heat and mass transport in micro channel are beingused extensively in researches and industrial applications to gain better understanding of thefundamental processes and to optimize fuel cell designs before building a prototype forengineering application. In this study, we used a single-phase, fully three dimensionalsimulation model for PEMFC that can deal with both anode and cathode flow field forexamining the micro flow channel with electrochemical reaction. The results show thathydrogen and oxygen were solely supplied to the membrane by diffusion mechanism ratherthan convection transport, and the higher pressure drop at cathode side is thought to becaused by higher flow rate of oxygen at cathode. And it is found that the amount of water incathode channel was determined by water formation due to electrochemical reaction pluselectro-osmotic mass flux directing toward the cathode side. And it is very important tomodel the back diffusion and electro-osmotic mass flux accurately since the two flux wasclosely correlated each other and greatly influenced for determination of ionic conductivityof the membrane which directly affects the performance of fuel cell.

  8. Three-Dimensional Transport Modeling for Proton Exchange Membrane(PEM) Fuel Cell with Micro Parallel Flow Field.

    Science.gov (United States)

    Lee, Pil Hyong; Han, Sang Seok; Hwang, Sang Soon

    2008-03-03

    Modeling and simulation for heat and mass transport in micro channel are beingused extensively in researches and industrial applications to gain better understanding of thefundamental processes and to optimize fuel cell designs before building a prototype forengineering application. In this study, we used a single-phase, fully three dimensionalsimulation model for PEMFC that can deal with both anode and cathode flow field forexamining the micro flow channel with electrochemical reaction. The results show thathydrogen and oxygen were solely supplied to the membrane by diffusion mechanism ratherthan convection transport, and the higher pressure drop at cathode side is thought to becaused by higher flow rate of oxygen at cathode. And it is found that the amount of water incathode channel was determined by water formation due to electrochemical reaction pluselectro-osmotic mass flux directing toward the cathode side. And it is very important tomodel the back diffusion and electro-osmotic mass flux accurately since the two flux wasclosely correlated each other and greatly influenced for determination of ionic conductivityof the membrane which directly affects the performance of fuel cell.

  9. Enhanced performance and stability of high temperature proton exchange membrane fuel cell by incorporating zirconium hydrogen phosphate in catalyst layer

    Science.gov (United States)

    Barron, Olivia; Su, Huaneng; Linkov, Vladimir; Pollet, Bruno G.; Pasupathi, Sivakumar

    2015-03-01

    Zirconium hydrogen phosphate (ZHP) together with polytetrafluoroethylene (PTFE) polymer binder is incorporated into the catalyst layers (CLs) of ABPBI (poly(2,5-benzimidazole))-based high temperature polymer electrolyte membrane fuel cell (HT-PEMFCs) to improve its performance and durability. The influence of ZHP content (normalised with respect to dry PTFE) on the CL properties are structurally characterised by scanning electron microscopy (SEM) and mercury intrusion porosimetry. Electrochemical analyses of the resultant membrane electrode assemblies (MEAs) are performed by recording polarisation curves and impedance spectra at 160 °C, ambient pressure and humidity. The result show that a 30 wt.% ZHP/PTFE content in the CL is optimum for improving fuel cell performance, the resultant MEA delivers a peak power of 592 mW cm-2 at a cell voltage of 380 mV. Electrochemical impedance spectra (EIS) indicate that 30% ZHP in the CL can increase the proton conductivity compared to the pristine PTFE-gas diffusion electrode (GDE). A short term stability test (∼500 h) on the 30 wt.% ZHP/PTFE-GDE shows a remarkable high durability with a degradation rate as low as ∼19 μV h-1 at 0.2 A cm-2, while 195 μV h-1 was obtained for the pristine GDE.

  10. Fabrication and characterisation of hydrogen fuel cell membrane electrode assemblies

    CSIR Research Space (South Africa)

    Mathe

    2006-09-01

    Full Text Available Proton-exchange membrane fuel cells (PEMFC) have been receiving attention owing to their highly attractive properties as a power source for both stationary and mobile applications. Fabrication of Membrane Electrode Assemblies (MEAs) is a key...

  11. Synthesis of electrocatalysts by the Bönnemann method for the oxidation of methanol and the mixture H2/CO in a Proton Exchange Membrane Fuel Cell

    Directory of Open Access Journals (Sweden)

    Franco E. G.

    2002-01-01

    Full Text Available The synthesis of ternary electrocatalysts Pt/Ru/Mo type were performed according to the Bönnemann method and characterized by the following techniques: energy dispersive analysis (EDX, X-rays diffraction (XRD, cyclic voltammetry (CV and polarization curves (E vs. i for the oxidation of H2, H2/CO and methanol in a Proton Exchange Membrane Fuel Cell (PEMFC. Catalysts structure consists of highly dispersed nanocrystals in carbon support, with an average particle size of 2 nm. The results of cyclic voltammetry suggest an enhancement of the catalyst electroactivity with the addition of cocatalysts. Polarization curves indicate that Pt/Ru/Mo systems could be employed as electrode material for PEM fuel cell for technological application.

  12. Platinum catalysts recovery of the proton exchange membrane fuel cell; Recuperacao de catalisadores de platina da celula a combustibel de membrana polimerica trocadora de protons

    Energy Technology Data Exchange (ETDEWEB)

    Fukurozaki, S.H.; Seo, E.S.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais. Lab. de Processamento de Residuos

    2006-07-01

    Currently, platinum is the most feasible catalyst for the Proton Exchange Membrane Fuel Cells - PEMFC. Along with platinum's significant importance in this energy system are the high cost of this noble metal and its detrimental effects on the environment. Therefore, recycling this material seems as an alternative to decrease its impacts on the environment and, at the same time, to provide a reduction of the system's costs. A search was conducted for literature and studies about platinum recycling methods. However, only two techniques of platinum recovery, which are still in development, were found. In face of this situation, a recovery method of platinum from deactivated Membrane Electrode Assembly - MEA's was developed, with attention to aspects related to the environment and the necessary requirements for its primary recycling. The results found showed a high recovery ratio and a possibility to reintroduce this metal into the production cycle. (author)

  13. Review on the Recent Developments of Photovoltaic Thermal (PV/T and Proton Exchange Membrane Fuel Cell (PEMFC Based Hybrid System

    Directory of Open Access Journals (Sweden)

    Zulkepli Afzam

    2016-01-01

    Full Text Available Photovoltaic Thermal (PV/T system emerged as one of the convenient type of renewable energy system acquire the ability to generate power and thermal energy in the absence of moving parts. However, the power output of PV/T is intermittent due to dependency on solar irradiation condition. Furthermore, its efficiency decreases because of cells instability at high temperature. On the other hand, fuel cell co-generation system (CGS is another technology that can generate power and heat simultaneously. Integration of PV/T and fuel cell CGS could enhance the reliability and sustainability of both systems as well as increasing the overall system performance. Hence, this paper intended to present the parameters that affect performance of PV/T and Proton Exchange Membrane Fuel Cell (PEMFC CGS. Moreover, recent developments on PV/T-fuel cell hybrid system are also presented. Based on literates, mass flow rate of moving fluid in PV/T was found to affect the system efficiency. For the PEMFC, when the heat is utilized, the system performance can be increased where the heat efficiency is similar to electrical efficiency which is about 50%. Recent developments of hybrid PV/T and fuel cell show that most of the studies only focus on the power generation of the system. There are less study on the both power and heat utilization which is indeed necessary in future development in term of operation strategy, optimization of size, and operation algorithm.

  14. A Comparison of Flow-Through Versus Non-Flow-Through Proton Exchange Membrane Fuel Cell Systems for NASA's Exploration Missions

    Science.gov (United States)

    Hoberecht, Mark A.

    2010-01-01

    As part of the Exploration Technology Development Program (ETDP) under the auspices of the Exploration Systems Mission Directorate (ESMD), NASA is developing both primary fuel cell power systems and regenerative fuel cell (RFC) energy storage systems within the fuel cell portion of the Energy Storage Project. This effort is being led by the NASA Glenn Research Center (GRC) in partnership with the NASA Johnson Space Center (JSC), Jet Propulsion Laboratory (JPL), NASA Kennedy Space Center (KSC), and industrial partners. The development goals are to improve fuel cell and electrolysis stack electrical performance, reduce system mass, volume, and parasitic power requirements, and increase system life and reliability. A major focus of this effort has been the parallel development of both flow-through and non-flow-through proton exchange membrane (PEM) primary fuel cell power systems. The plan has been, at the appropriate time, to select a single primary fuel cell technology for eventual flight hardware development. Ideally, that appropriate time would occur after both technologies have achieved a technology readiness level (TRL) of six, which represents an engineering model fidelity PEM fuel cell system being successfully tested in a relevant environment. Budget constraints in fiscal year 2009 and beyond have prevented NASA from continuing to pursue the parallel development of both primary fuel cell options. Because very limited data exists for either system, a toplevel, qualitative assessment based on engineering judgement was performed expeditiously to provide guidance for a selection. At that time, the non-flow-through technology was selected for continued development because of potentially major advantages in terms of weight, volume, parasitic power, reliability, and life. This author believes that the advantages are significant enough, and the potential benefits great enough, to offset the higher state of technology readiness of flow-through technology. This paper

  15. Vertically aligned carbon-coated titanium dioxide nanorod arrays on carbon paper with low platinum for proton exchange membrane fuel cells

    Science.gov (United States)

    Jiang, Shangfeng; Yi, Baolian; Zhang, Changkun; Liu, Sa; Yu, Hongmei; Shao, Zhigang

    2015-02-01

    Carbon-coated titanium dioxide (TiO2-C) has received much attention as a catalyst support in proton exchange membrane fuel cells. In this study, TiO2 nanorod arrays (NRs) are hydrothermally grown on carbon paper and converted into TiO2-C NRs by heat treatment at 900 °C under methane atmosphere. Then, platinum nanoparticles are sputtered onto the TiO2 NRs by physical vapor deposition to produce Pt-TiO2-C. The as-prepared Pt-TiO2-C exhibits high stability during accelerated durability tests. As compared with the commercial gas diffusion electrode (GDE, 34.4% decrease), a minor reduction in the electrochemically active surface area of the Pt-TiO2-C electrode after 1500 cycles (10.6% decrease) is observed. When the as-prepared electrode with ultra-low platinum content (Pt loading: 28.67 μg cm-2) is employed as the cathode of a single cell, the electrode generates power that is 4.84 × that of the commercial GDE (Pt loading: 400 μg cm-2). An electrode that generates power of 11.9 kW gPt-1 (as the cathode) is proposed. The fabricated Pt-TiO2-C electrode can be used in proton exchange membrane fuel cells.

  16. Simultaneous Congo red decolorization and electricity generation in air-cathode single-chamber microbial fuel cell with different microfiltration, ultrafiltration and proton exchange membranes.

    Science.gov (United States)

    Hou, Bin; Sun, Jian; Hu, Yong-you

    2011-03-01

    Different microfiltration membrane (MFM), proton exchange membrane (PEM) and ultrafiltration membranes (UFMs) with different molecular cutoff weights of 1K (UFM-1K), 5K (UFM-5K) and 10K (UFM-10K) were incorporated into air-cathode single-chamber microbial fuel cells (MFCs) which were explored for simultaneous azo dye decolorization and electricity generation to investigate the effect of membrane on the performance of the MFC. Batch test results showed that the MFC with an UFM-1K produced the highest power density of 324 mW/m(2) coupled with an enhanced coulombic efficiency compared to MFM. The MFC with UMF-10K achieved the fastest decolorization rate (4.77 mg/L h), followed by MFM (3.61 mg/L h), UFM-5K (2.38 mg/L h), UFM-1K (2.02 mg/Lh) and PEM (1.72 mg/Lh). These results demonstrated the possibility of using various membranes in the system described here, and showed that UFM-1K was the best one based on the consideration of both cost and performance. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Sulfonated Holey Graphene Oxide (SHGO) Filled Sulfonated Poly(ether ether ketone) Membrane: The Role of Holes in the SHGO in Improving Its Performance as Proton Exchange Membrane for Direct Methanol Fuel Cells.

    Science.gov (United States)

    Jiang, Zhong-Jie; Jiang, Zhongqing; Tian, Xiaoning; Luo, Lijuan; Liu, Meilin

    2017-06-14

    Sulfonated holey graphene oxides (SHGOs) have been synthesized by the etching of sulfonated graphene oxides with concentrated HNO 3 under the assistance of ultrasonication. These SHGOs could be used as fillers for the sulfonated aromatic poly(ether ether ketone) (SPEEK) membrane. The obtained SHGO-incorporated SPEEK membrane has a uniform and dense structure, exhibiting higher performance as proton exchange membranes (PEMs), for instance, higher proton conductivity, lower activation energy for proton conduction, and comparable methanol permeability, as compared to Nafion 112. The sulfonated graphitic structure of the SHGOs is believed to be one of the crucial factors resulting in the higher performance of the SPEEK/SHGO membrane, since it could increase the local density of the -SO 3 H groups in the membrane and induce a strong interfacial interaction between SHGO and the SPEEK matrix, which improve the proton conductivity and lower the swelling ratio of the membrane, respectively. Additionally, the proton conductivity of the membrane could be further enhanced by the presence of the holes in the graphitic planes of the SHGOs, since it provides an additional channel for transport of the protons. When used, direct methanol fuel cell with the SPEEK/SHGO membrane is found to exhibit much higher performance than that with Nafion 112, suggesting potential use of the SPEEK/SHGO membrane as the PEMs.

  18. Highly efficient transition metal and nitrogen co-doped carbide-derived carbon electrocatalysts for anion exchange membrane fuel cells

    Science.gov (United States)

    Ratso, Sander; Kruusenberg, Ivar; Käärik, Maike; Kook, Mati; Puust, Laurits; Saar, Rando; Leis, Jaan; Tammeveski, Kaido

    2018-01-01

    The search for an efficient electrocatalyst for oxygen reduction reaction (ORR) to replace platinum in fuel cell cathode materials is one of the hottest topics in electrocatalysis. Among the many non-noble metal catalysts, metal/nitrogen/carbon composites made by pyrolysis of cheap materials are the most promising with control over the porosity and final structure of the catalyst a crucial point. In this work we show a method of producing a highly active ORR catalyst in alkaline media with a controllable porous structure using titanium carbide derived carbon as a base structure and dicyandiamide along with FeCl3 or CoCl2 as the dopants. The resulting transition metal-nitrogen co-doped carbide derived carbon (M/N/CDC) catalyst is highly efficient for ORR electrocatalysis with the activity in 0.1 M KOH approaching that of commercial 46.1 wt.% Pt/C. The catalyst materials are also investigated by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy to characterise the changes in morphology and composition causing the raise in electrochemical activity. MEA performance of M/N/CDC cathode materials in H2/O2 alkaline membrane fuel cell is tested with the highest power density reached being 80 mW cm-2 compared to 90 mW cm-2 for Pt/C.

  19. Synthesis and characterization of sulfonated cardo poly(arylene ether sulfone)s for fuel cell proton exchange membrane application

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M.M.; Jang, H.H.; Lim, Y.D.; Seo, D.W.; Kim, W.G. [Department of Applied Chemistry, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kim, T.H.; Hong, Y.T. [Energy Material Research Center, Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of); Kim, D.M. [Material Engineering and Science, Hongik Univ, Jochiwon-eup, Yeongi-gun, Chungnam (Korea, Republic of)

    2012-12-15

    Sulfonated cardo poly(arylene ether sulfone)s (SPPA-PES) with various degrees of sulfonation (DS) were prepared by post-sulfonation of synthesized phenolphthalein anilide (PPA; N-phenyl-3,3'-bis(4-hydroxyphenyl)-1-isobenzopyrolidone) poly(arylene ether sulfone)s (PPA-PES) by using concentrated sulfuric acid. PPA-PES copolymers were synthesized by direct polycondensation of PPA with bis-(4-fluorophenyl)-sulfone and 4,4'-sulfonyldiphenol. The DS was varied with different mole ratios of PPA (24, 30, 40, 50 mol.%) in the polymer. The structure of the resulting SPPA-PES copolymers and the different contents of the sulfonated unit were studied by Fourier transform infrared (FT-IR) spectroscopy, {sup 1}H NMR spectroscopy, and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity of SPPA-PES were evaluated according to the increase of DS. The water uptake (WU) of the resulting SPPA-PES membranes was in the range of 20-72%, compared with 28% for Nafion 211 registered. The SPPA-PES membranes showed proton conductivities of 23-82 mS cm{sup -1}, compared with 194 mS cm{sup -1} for Nafion 211 registered, under 100% relative humidity (RH) at 80 C. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. A Comprehensive Review on Measurement and Correlation Development of Capillary Pressure for Two-Phase Modeling of Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Chao Si

    2015-01-01

    Full Text Available Water transport and the corresponding water management strategy in proton exchange membrane (PEM fuel cells are quite critical for the improvement of the cell performance. Accuracy modeling of water transport in porous electrodes strongly depends on the appropriate constitutive relationship for capillary pressure which is referred to as pc-s correlation, where pc is the capillary pressure and s is the fraction of saturation in the pores. In the present PEM fuel cell two-phase models, the Leverett-Udell pc-s correlation is widely utilized which is proposed based on fitting the experimental data for packed sands. However, the size and structure of pores for the commercial porous electrodes used in PEM fuel cells differ from those for the packed sands significantly. As a result, the Leverett-Udell correlation should be improper to characterize the two-phase transport in the porous electrodes. In the recent decade, many efforts were devoted to measuring the capillary pressure data and developing new pc-s correlations. The objective of this review is to review the most significant developments in recent years concerning the capillary pressure measurements and the developed pc-s correlations. It is expected that this review will be beneficial to develop the improved PEM fuel cell two-phase model.

  1. Efficiency measurement and uncertainty discussion of an electric engine powered by a "self-breathing" and "self-humidified" proton exchange membrane fuel cell.

    Science.gov (United States)

    Schiavetti, Pierluigi; Del Prete, Zaccaria

    2007-08-01

    The efficiency of an automotive engine based on a "self-breathing" and "self-humidified" proton exchange membrane fuel cell stack (PEM FC) connected to a dc brushless electrical motor was measured under variable power load conditions. Experiments have been carried out on a small scale 150 W engine model. After determining the fuel cell static polarization curve and the time response to power steps, the system was driven to copy on the test bench a "standard urban load cycle" and its instantaneous efficiencies were measured at an acquisition rate of 5 Hz. The integral system efficiency over the entire urban load cycle, comprising the losses of the unavoidable auxiliary components of the engine, was then calculated. The fuel cell stack was operated mainly in "partial" dead-end mode, with a periodic anode flow channel purging, and one test was carried out in "pure" dead-end mode, with no anode channel purging. An uncertainty analysis of the efficiencies was carried out, taking into account either type A and type B evaluation methods, strengthening the discussion about the outcomes obtained for a system based on this novel simplified FC type. For our small scale engine we measured over the standard urban cycle, on the basis of the H(2) high heating value (HHV), a tank-to-wheel integral efficiency of (18.2+/-0.8)%, when the fuel cell was operated with periodic flow channel purging, and of (21.5+/-1.3)% in complete dead-end operation mode.

  2. Advancements in Anion Exchange Membrane Cations

    Energy Technology Data Exchange (ETDEWEB)

    Sturgeon, Matthew R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Long, Hai [National Renewable Energy Lab. (NREL), Golden, CO (United States); Park, Andrew M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pivovar, Bryan S. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-10-15

    Anion-exchange membrane fuel cells (AME-FCs) are of increasingly popular interest as they enable the use of non-Pt fuel cell catalysts, the primary cost limitation of proton exchange membrane fuel cells. Benzyltrimethyl ammonium (BTMA) is the standard cation that has historically been utilized as the hydroxide conductor in AEMs. Herein we approach AEMs from two directions. First and foremost we study the stability of several different cations in a hydroxide solution at elevated temperatures. We specifically targeted BTMA and methoxy and nitro substituted BTMA. We've also studied the effects of adding an akyl spacer units between the ammonium cation and the phenyl group. In the second approach we use computational studies to predict stable ammonium cations, which are then synthesized and tested for stability. Our unique method to study cation stability in caustic conditions at elevated temperatures utilizes Teflon Parr reactors suitable for use under various temperatures and cation concentrations. NMR analysis was used to determine remaining cation concentrations at specific time points with GCMS analysis verifying product distribution. We then compare the experimental results with calculated modeling stabilities. Our studies show that the electron donating methoxy groups slightly increase stability (compared to that of BTMA), while the electron withdrawing nitro groups greatly decrease stability in base. These results give insight into possible linking strategies to be employed when tethering a BTMA like ammonium cation to a polymeric backbone; thus synthesizing an anion exchange membrane.

  3. Electroless Ni-Cu-P/nano-graphite composite coatings for bipolar plates of proton exchange membrane fuel cells

    Science.gov (United States)

    Lee, Cheng-Kuo

    2012-12-01

    This study evaluates the effects of an electroless Ni-Cu-P/nano-graphite composite coating on the surface characteristics of anodized 5083 aluminum alloy, including electrical resistivity, corrosion resistance of the alloy in a simulated solution of 0.5 M H2SO4 + 2 ppm NaF in polymer electrolyte membrane fuel cells (PEMFCs). The co-deposition and adhesion of the composite coatings on a 5083 substrate are enhanced by an anodizing process. The electroless Ni-Cu-P plating solution is prepared by adding different CuSO4·5H2O concentrations into the electroless Ni-P plating solution and adding nano-graphite (15-40 nm) particles to form the Ni-Cu-P/nano-graphite composite coatings. Experimental results indicate that the electroless Ni-Cu-P/nano-graphite composite coating enhances the hardness, conductivity, corrosion resistance of the 5083 substrate in the corrosive solution. The anodizing treatment enhances the electroless composite coatings by providing better uniformity, density, and adhesion compared to substrate without anodizing treatment. The electroless Ni-Cu-P/nano-graphite composite coating deposited on the optimal anodized 5083 substrate at a low CuSO4·5H2O concentration of 0.25 g l-1 with 20 g l-1 nano-graphite added have the best surface structure, highest hardness, electrical conductivity and corrosion resistance. Therefore, this novel electroless Ni-Cu-P/nano-graphite composite-coated 5083 aluminum alloy has potential applications in bipolar plates of PEM fuel cells.

  4. Investigation of carbon supported PtW catalysts as CO tolerant anodes at high temperature in proton exchange membrane fuel cell

    Science.gov (United States)

    Hassan, Ayaz; Paganin, Valdecir A.; Ticianelli, Edson A.

    2016-09-01

    The CO tolerance mechanism and the stability of carbon supported PtW electrocatalysts are evaluated in the anode of a proton exchange membrane fuel cell (PEMFC) at two different temperatures. The electrocatalysts are characterized by energy dispersive spectroscopy, X-ray diffraction, and transmission electron spectroscopy. Employed electrochemical techniques include cyclic voltammetry, CO stripping, fuel cell polarization, and online mass spectrometry. At a cell temperature of 85 °C, the PtW/C catalyst shows higher CO tolerance compared to Pt/C due an electronic effect of WOx in the Pt 5d band, which reduces the CO adsorption. An increase in hydrogen oxidation activity in the presence of CO is observed for both the catalysts at a higher temperature, due to the decrease of the Pt-CO coverage. A reduction in the current densities occurs for the PtW/C catalyst in both polarization curves and cyclic voltammograms after 5000 cycles of the anode in the range of 0.1-0.7 V vs. RHE at 50 mVs-1. This decrease in performance is assigned to the dissolution of W, with a consequent increase in the membrane resistivity. However, the observed decline of performance is small either in the presence of pure H2 or in the presence of H2/CO.

  5. Local potential evolutions during proton exchange membrane fuel cell operation with dead-ended anode - Part II: Aging mitigation strategies based on water management and nitrogen crossover

    Science.gov (United States)

    Abbou, S.; Dillet, J.; Maranzana, G.; Didierjean, S.; Lottin, O.

    2017-02-01

    Proton exchange membrane (PEM) fuel cells operate with dead-ended anode in order to reduce system cost and complexity when compared with hydrogen re-circulation systems. In the first part of this work, we showed that localized fuel starvation events may occur, because of water and nitrogen accumulation in the anode side, which could be particularly damaging to the cell performance. To prevent these degradations, the anode compartment must be purged which may lead to an overall system efficiency decrease because of significant hydrogen waste. In the second part, we present several purge strategies in order to minimize both hydrogen waste and membrane-electrode assembly degradations during dead-ended anode operation. A linear segmented cell with reference electrodes was used to monitor simultaneously the current density distribution along the gas channel and the time evolution of local anode and cathode potentials. To asses MEA damages, Platinum ElectroChemical Surface Area (ECSA) and cell performance were periodically measured. The results showed that dead-end mode operation with an anode plate maintained at a temperature 5 °C hotter than the cathode plate limits water accumulation in the anode side, reducing significantly purge frequency (and thus hydrogen losses) as well as MEA damages. As nitrogen contribution to hydrogen starvation is predominant in this thermal configuration, we also tested a microleakage solution to discharge continuously most the nitrogen accumulating in the anode side while ensuring low hydrogen losses and minimum ECSA losses provided the right microleakage flow rate is chosen.

  6. Pervaporation with ion exchange membranes

    Energy Technology Data Exchange (ETDEWEB)

    Boeddeker, K.W.; Wenzlaff, A.

    1986-01-01

    Sorption and pervaporation of aqueous-organic solvent systems (water-ethanol; water-carboxylic acids) with commercial ion exchange membranes are compared to obtain information on polymersolvent interaction vs. coupling. Close agreement between sorption selectivity and pervaporation selectivity indicates coupling. If pervaporation is less selective than sorption, polymer-solvent interaction overtakes coupling, the limit of de-coupling being phase separation within the sorbate as signaled by a sudden increase in permeability of the lesser interacting component. As long as sorption and pervaporation operate in parallel, favoring enrichment of the same component, coupling enhances the separation effect. If pervaporation counteracts sorption, coupling is detrimental to the separation effect. Potential applications include the dehydration of pre-concentrated water-ethanol using anion exchange membranes, and the enrichment of acetic acid from dilute aqueous solution by pervaporative removal of water through cation exchange membranes.

  7. Gram-Scale Synthesis of Highly Active and Durable Octahedral PtNi Nanoparticle Catalysts for Proton Exchange Membrane Fuel Cell

    DEFF Research Database (Denmark)

    Choi, Juhyuk; Jang, Jue-Hyuk; Roh, Chi-Woo

    2018-01-01

    , compared to commercial Pt/C (0.22 A mgPt−1). Single-cell performance and electrochemical impedance spectroscopy (EIS) were also tested. The PtNi@Pt catalysts showed enhanced current density of 3.1 A cm−2 at 0.6 V in O2 flow while the commercial Pt/C had the value of 2.5 A cm−2. After 30,000 cycles......Proton exchange membrane fuel cells (PEMFC) are regarded as a promising renewable energy source for a future hydrogen energy society. However, highly active and durable catalysts are required for the PEMFCs because of their intrinsic high overpotential at the cathode and operation under the acidic...... condition for oxygen reduction reaction (ORR). Since the discovery of the exceptionally high surface activity of Pt3Ni(111), the octahedral PtNi nanoparticles have been synthesized and tested. Nonetheless, their milligram-scale synthesis method and poor durability make them unsuitable...

  8. New Method for Super Hydrophobic Treatment of Gas Diffusion Layers for Proton Exchange Membrane Fuel Cells Using Electrochemical Reduction of Diazonium Salts.

    Science.gov (United States)

    Thomas, Yohann R J; Benayad, Anass; Schroder, Maxime; Morin, Arnaud; Pauchet, Joël

    2015-07-15

    The purpose of this article is to report a new method for the surface functionalization of commercially available gas diffusion layers (GDLs) by the electrochemical reduction of diazonium salt containing hydrophobic functional groups. The method results in superhydrophobic GDLs, over a large area, without pore blocking. An X-ray photoelectron spectroscopy study based on core level spectra and chemical mapping has demonstrated the successful grafting route, resulting in a homogeneous distribution of the covalently bonded hydrophobic molecules on the surface of the GDL fibers. The result was corroborated by contact angle measurement, showing similar hydrophobicity between the grafted and PTFE-modified GDLs. The electrochemically modified GDLs were tested in proton exchange membrane fuel cells under automotive, wet, and dry conditions and demonstrated improved performance over traditional GDLs.

  9. SSH2S: Hydrogen storage in complex hydrides for an auxiliary power unit based on high temperature proton exchange membrane fuel cells

    Science.gov (United States)

    Baricco, Marcello; Bang, Mads; Fichtner, Maximilian; Hauback, Bjorn; Linder, Marc; Luetto, Carlo; Moretto, Pietro; Sgroi, Mauro

    2017-02-01

    The main objective of the SSH2S (Fuel Cell Coupled Solid State Hydrogen Storage Tank) project was to develop a solid state hydrogen storage tank based on complex hydrides and to fully integrate it with a High Temperature Proton Exchange Membrane (HT-PEM) fuel cell stack. A mixed lithium amide/magnesium hydride system was used as the main storage material for the tank, due to its high gravimetric storage capacity and relatively low hydrogen desorption temperature. The mixed lithium amide/magnesium hydride system was coupled with a standard intermetallic compound to take advantage of its capability to release hydrogen at ambient temperature and to ensure a fast start-up of the system. The hydrogen storage tank was designed to feed a 1 kW HT-PEM stack for 2 h to be used for an Auxiliary Power Unit (APU). A full thermal integration was possible thanks to the high operation temperature of the fuel cell and to the relative low temperature (170 °C) for hydrogen release from the mixed lithium amide/magnesium hydride system.

  10. Modelling of the vapour-liquid equilibrium of water and the in situ concentration of H3PO4 in a high temperature proton exchange membrane fuel cell

    Science.gov (United States)

    Kazdal, Timur J.; Lang, Sebastian; Kühl, Frank; Hampe, Manfred J.

    2014-03-01

    The fuel cell technology is a key element for the hydrogen energy economy and therefore crucial for sustainable development. High temperature proton exchange membrane (HT-PEM) fuel cells (FC) can be operated with reformate gas and thus represent an important bridging technology for the energy transition to a renewable energy based system. HT-PEM FCs based on phosphoric acid (PA) are still subject to intense research, investigating the electrolyte behaviour. By enhancing state of the art 2D FEM simulations of FCs with the vapour liquid equilibrium of water-phosphoric acid and evaporation kinetics, a model was created in which the local concentration of PA can be calculated. Knowledge of the concentration field yields the basis for calculating the locally varying ionic conductivity and other physical properties. By describing the volume expansion behaviour of PA it was possible to predict the catalyst particle deactivation due to the swelling of PA. The in situ concentration predicted by the simulation ranges from 96 to 111 wt%. The model was validated using measured data of a single cell design for different temperatures and pressures. By varying the PA content flooding of the simulated fuel cell could be observed and was linked to humidification effects.

  11. Renewable Electricity Generation via Solar-Powered Methanol Reforming: Hybrid Proton Exchange Membrane Fuel Cell Systems Based on Novel Non-Concentrating, Intermediate-Temperature Solar Collectors

    Science.gov (United States)

    Real, Daniel J.

    Tremendous research efforts have been conducted studying the capturing and conversion of solar energy. Solar thermal power systems offer a compelling opportunity for renewable energy utilization with high efficiencies and excellent cost-effectiveness. The goal of this work was to design a non-concentrating collector capable of reaching temperatures above 250 °C, use this collector to power methanol steam reforming, and operate a proton exchange membrane (PEM) fuel cell using the generated hydrogen. The study presents the construction and characterization of a non-concentrating, intermediate-temperature, fin-in-tube evacuated solar collector, made of copper and capable of reaching stagnation temperatures of 268.5 °C at 1000 W/m2 irradiance. The collector was used to power methanol steam reforming, including the initial heating and vaporization of liquid reactants and the final heating of the gaseous reactants. A preferential oxidation (PROX) catalyst was used to remove CO from simulated reformate gas, and this product gas was used to operate a PEM fuel cell. The results show 1) that the outlet temperature is not limited by heat transfer from the absorber coating to the heat transfer fluid, but by the amount of solar energy absorbed. This implicates a constant heat flux description of the heat transfer process and allows for the usage of materials with lower thermal conductivity than copper. 2) It is possible to operate a PEM fuel cell from reformate gas if a PROX catalyst is used to remove CO from the gas. 3) The performance of the fuel cell is only slightly decreased (~4%) by CO2 dilution present in the reformate and PROX gas. These results provide a foundation for the first renewable electricity generation via solar-powered methanol reforming through a hybrid PEM fuel cell system based on novel non-concentrating, intermediate-temperature solar collectors.

  12. Electrochemical Behavior and Hydrophobic Properties of CrN and CrNiN Coatings in Simulated Proton Exchange Membrane Fuel Cell Environment

    Directory of Open Access Journals (Sweden)

    JIN Jie

    2016-10-01

    Full Text Available The CrN and CrNiN coatings were prepared on the surface of 304 stainless steel by closed field unbalanced magnetron sputtering.X ray diffraction and field emission scanning electron microscopy were used to characterize the structure and morphology of the coatings.The electrochemical corrosion properties under the simulated proton exchange membrane fuel cell(PEMFC environment, interfacial contact resistance and hydrophobic properties of the two kinds of different coatings were investigated by electrochemical methods,contact resistance test and hydrophobic test,respectively.The results indicate that CrN coating mainly consists of CrN and Cr2N phase,CrN and Cr2N phases in the CrNiN coating are less compared to CrN film, and Ni exist as element in CrNiN coating; dynamic polarization tests show the coating is of better corrosion resistance,whereas the corrosion resistance of CrNiN coating is worse than that of CrN coating,constant potential polarization test shows the corrosion current density of CrN and CrNiN coatings are equivalent; CrN and CrNiN coatings significantly reduce the interfacial contact resistance of the 304 stainless steel,among which CrN coating has the smallest contact resistance; and CrNiN coating which has better hydrophobicity than that of CrN coating is more beneficial for the water management in proton exchange membrane fuel cell.

  13. 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...... 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...

  14. Preparation and characterization of sulfonated amine-poly(ether sulfone)s for proton exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Dong-Wan; Lim, Young-Don; Lee, Soon-Ho; Jeong, Young-Gi; Kim, Whan-Gi [Department of Applied Chemistry/RIC-ReSEM, Konkuk University, Chungju-si, Chungbuk 380-701 (Korea, Republic of); Hong, Tae-Whan [Department of Materials Sci and Engineering/RIC-ReSEM, Chungju National University, Chungju, Chungbuk (Korea, Republic of)

    2010-12-15

    Sulfonated amine-poly(ether sulfone)s (S-APES)s were prepared by nitration, reduction and sulfonation of poly(ether sulfone) (ultrason {sup registered} -S6010). Poly(ether sulfone) was reacted with ammonium nitrate and trifluoroacetic anhydride to produce the nitrated poly(ether sulfone), and was followed by reduction using tin(II)chloride and sodium iodide as reducing agents to give the amino-poly(ether sulfone). The S-APES was obtained by reaction of 1,3-propanesultone and the amino-poly(ether sulfone) (NH{sub 2}-PES) with sodium methoxide. The different degrees of nitration and reduction of poly(ether sulfone) were successfully synthesized by an optimized process. The reduction of nitro group to amino was done quantitatively, and this controlled the contents of the sulfonic acid group. The films were converted from salt to acid forms with dilute hydrochloric acid. Different contents of sulfonated unit of the S-APES were studied by FT-IR, {sup 1}H NMR spectroscopy, differential scanning calorimetry (DSC), and thermo gravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. The ion exchange capacity (IEC), a measure of proton conductivity, was evaluated. The S-APES membranes exhibit conductivities (25 C) from 1.05 x 10{sup -3} to 4.83 x 10{sup -3} S/cm, water swell from 30.25 to 66.50%, IEC from 0.38 to 0.82 meq/g, and methanol diffusion coefficients from 3.10 x 10{sup -7} to 4.82 x 10{sup -7} cm{sup 2}/S at 25 C. (author)

  15. Synthesis and characterization of high performing Fe-N-C catalyst for oxygen reduction reaction (ORR) in Alkaline Exchange Membrane Fuel Cells

    Science.gov (United States)

    Hossen, Md Mosaddek; Artyushkova, Kateryna; Atanassov, Plamen; Serov, Alexey

    2018-01-01

    In this article, three different Fe-N-C oxygen reduction reaction (ORR) catalysts derived from different organic molecules i.e. Fe-NMG, Fe-NMP, Fe-MBZ have been synthesized, characterized by physical-chemical methods and studied in the reaction of oxygen reduction (ORR). It is found that Fe-NMG shows higher ORR performance than Fe-NMP and Fe-MBZ, by both rotating ring disk electrode (RRDE) and fuel cell tests. From characterization and surface analysis, it can be explained that the presence of higher amount of surface oxides and pyridinic nitrogen is the main reason for better performance towards ORR in alkaline media. To achieve the highest performance in alkaline exchange membrane fuel cell (AEMFC), the optimization of catalyst layer composition using various concentrations of ionomer (Tokuyama, AS4) was performed. At the optimum cathode layer configuration utilizing Fe-NMG produces the peak power density of 218 mWcm-2, which is one of the highest values presented in the open literature.

  16. Production of high-performance and improved-durability Pt-catalyst /support for proton-exchange-membrane fuel cells with pulsed laser deposition

    Science.gov (United States)

    Huang, Ting-Wei; Qayyum, Hamza; Lin, Guan-Ren; Chen, Szu-yuan; Tseng, Chung-Jen

    2016-06-01

    Pulsed laser deposition in Ar atmosphere is used to deposit Pt nanoparticles onto gas diffusion layer, and its application to proton-exchange-membrane fuel cell is optimized and characterized. When used at anode side, with a Pt loading of 17 μg cm-2 the fuel-cell current density at 0.6 V reaches 1.08 A cm-2, which is close to that of a cell with the anode made by conventional slurry process using E-TEK Pt /C of 200 μg cm-2 Pt loading. The usage of Pt is decreased by 12 fold. Such a low usage of Pt prepared by pulsed laser deposition can be ascribed to the prevention of forming isolated regions that occurs with Pt /C slurry, good dispersion of Pt particles on support, and small particle sizes of 2-3 nm. Furthermore, using accelerated degradation test, it is found that the pulsed laser deposition sample retains 60% of its initial electrochemical surface area after 5000 potential cycles, much higher than that with E-TEK Pt /C, which retains only 7% of its initial electrochemical surface area. The higher electrochemical durability can be attributed to the higher degree of graphitization in the gas diffusion layer used as compared with the carbon black in E-TEK Pt /C, which leads to stronger binding of the Pt nanoparticles onto the carbon support and stronger corrosion resistance of the carbon support.

  17. Method of fabricating electrode catalyst layers with directionally oriented carbon support for proton exchange membrane fuel cell

    Science.gov (United States)

    Liu, Di-Jia [Naperville, IL; Yang, Junbing [Bolingbrook, IL

    2012-03-20

    A membrane electrode assembly (MEA) of the invention comprises an anode and a cathode and a proton conductive membrane therebetween, the anode and the cathode each comprising a patterned sheet of longitudinally aligned transition metal-containing carbon nanotubes, wherein the carbon nanotubes are in contact with and are aligned generally perpendicular to the membrane, wherein a catalytically active transition metal is incorporated throughout the nanotubes.

  18. Comparison of The Performance of Proton Exchange Membrane Fuel Cell (PEMFC Electrodes with Different Carbon Powder Content and Methods of Manufacture

    Directory of Open Access Journals (Sweden)

    Dedi Rohendi

    2016-11-01

    Full Text Available Carbon powder in the gas diffusion layer (GDL contained in the membrane electrode assembly (MEA has an important role in the flow of electrons and reactant gas. Meanwhile, the method of making the electrode is one of the many studies conducted to determine the most appropriate method to use. Comparative study of the performance of proton exchange membrane fuel cell (PEMFC electrodes with different carbon powder content (vulcan XC-72 in the GDL and methods of manufacture of the electrode between casting and spraying method has been carried out. The spraying method consists of one layer and three layer of catalyst layer (CL. The content of carbon powder in the GDL as much as 3 mg cm-2 has a better performance compared to 1.5 mg cm-2 with an increase of 177.78% current density at 0.6 V. Meanwhile, the manufacture of CL with three-layer spraying method has better performance compared with one-layer spraying and casting method.

  19. 3D-Graphene supports for palladium nanoparticles: Effect of micro/macropores on oxygen electroreduction in Anion Exchange Membrane Fuel Cells

    Science.gov (United States)

    Kabir, Sadia; Serov, Alexey; Atanassov, Plamen

    2018-01-01

    Hierarchically structured 3D-Graphene nanosheets as supports for palladium nanoparticles (Pd/3D-GNS) were fabricated using the Sacrificial Support Method. The pore size distribution of the 3D-GNS supports were tuned by utilizing smaller and larger sized sacrificial silica templates, EH5 and L90. Using a combination of Scanning Electron Microscopy (SEM), N2 sorption and Rotating Ring Disc Electrode (RRDE) technique, it was demonstrated that the EH5 and L90 modified 3D-GNS supports had higher percentage of micro- (50 nm), respectively. The templated pores also played a role in enhancing the oxygen reduction reaction (ORR) as well as membrane electrode assembly (MEA) performance of the Pd nanoparticles in comparison to non-porous 2D-GNS supports. Particularly, incorporation of micropores increased peroxide generation at higher potentials whereas presence of macropores increased both limiting current densities and reduce peroxide yields. Integration of the Pd/GNS nanocomposites into a H2/O2 fed Anion Exchange Membrane Fuel Cell (AEMFC) operating at 60 °C also demonstrated the effect of modified porosity on concentration polarization or transport losses at high current densities. This strategy for the tunable synthesis of hierarchically 3D porous graphitized supports offers a platform for developing morphologically modified nanomaterials for energy conversion.

  20. Microscale X-ray tomographic investigation of the interfacial morphology between the catalyst and micro porous layers in proton exchange membrane fuel cells

    Science.gov (United States)

    Prass, Sebastian; Hasanpour, Sadegh; Sow, Pradeep Kumar; Phillion, André B.; Mérida, Walter

    2016-07-01

    The interfacial morphology between the catalyst layer (CL) and micro porous layer (MPL) influences the performance of proton exchange membrane fuel cells (PEMFCs). Here we report a direct method to investigate the CL-MPL interfacial morphology of stacked and compressed gas diffusion layer (GDL with MPL)-catalyst coated membrane (CCM) assemblies. The area, origin and dimensions of interfacial gaps are studied with high-resolution X-ray micro computed tomography (X-μCT). The projected gap area (fraction of the CL-MPL interface separated by gaps) is higher for GDL-CCM assemblies with large differences in the surface roughness between CL and MPL but reduces with increasing compression and similarity in roughness. Relatively large continuous gaps are found in proximity to cracks in the MPL. These are hypothesized to form due to the presence of large pores on the surface of the GDL. Smaller gaps are induced by the surface roughness features throughout the CL-MPL interface. By modification of the pore sizes on the GDL surface serving as substrate for the MPL, the number and dimension of MPL crack induced gaps can be manipulated. Moreover, adjusting the CL and MPL surface roughness parameters to achieve similar orders of roughness can improve the surface mating characteristics of these two components.

  1. Imidazolium-based anion exchange membranes for alkaline anion fuel cells: (2) elucidation of the ionic structure and its impact on conducting properties.

    Science.gov (United States)

    Yoshimura, Kimio; Zhao, Yue; Hasegawa, Shin; Hiroki, Akihiro; Kishiyama, Yoshihiro; Shishitani, Hideyuki; Yamaguchi, Susumu; Tanaka, Hirohisa; Koizumi, Satoshi; Appavou, Marie-Sousai; Radulescu, Aurel; Richter, Dieter; Maekawa, Yasunari

    2017-11-22

    In our previous study (Soft Matter, 2016, 12, 1567), the relationship between the morphology and properties of graft-type imidazolium-based anion exchange membranes (AEMs) was revealed, in that the semi-crystalline features of the polymer matrix maintain its mechanical properties and the formation of interconnected hydrophilic domains promotes the membrane conductivity. Here, we report a novel ionic structure of the same graft-type AEMs with different grafting degrees, analyzed using a small-angle X-ray scattering method under different relative humidity (RH) conditions. The characteristic "ionomer peak" with a corresponding correlation distance of approximately 1.0 nm was observed at RH ionic clusters, but close to the Bjerrum length of water. Since the representative number of water molecules per cation, nw, was small, we proposed that dissociated ion-pairs are distributed in the hydrophilic domains (ion-channels). At RH < 80%, ion-channels are disconnected, however in liquid water, they are well-connected as evidenced by the sharp increase in nw. The disconnected ion-channels even under relatively high RH conditions should be a substantial factor for the low power generation efficiency of AEM-type fuel cells.

  2. Fuel cell with ionization membrane

    Science.gov (United States)

    Hartley, Frank T. (Inventor)

    2007-01-01

    A fuel cell is disclosed comprising an ionization membrane having at least one area through which gas is passed, and which ionizes the gas passing therethrough, and a cathode for receiving the ions generated by the ionization membrane. The ionization membrane may include one or more openings in the membrane with electrodes that are located closer than a mean free path of molecules within the gas to be ionized. Methods of manufacture are also provided.

  3. 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...

  4. Modeling and control of a proton exchange membrane fuel cell with the air compressor according to requested electrical current

    Directory of Open Access Journals (Sweden)

    Malekbala Mohammad Rahim

    2015-01-01

    Full Text Available The aim of this paper is to design and investigate the dynamic behavior of a PEM fuel cell system. Dynamic analysis of a PEM fuel cell system has been done in Matlab\\Simulink software according to electrical current that has been applied from hybrid system. In addition, dynamical fuel cell system has been explained according to oriented control that is started from air injection compressor model. Also hydrogen valve actuator has been controlled according to the compressor model. The results of the fuel cell dynamic model as well as the applied compressor model are fully validated based on the available results in the open literature. Finally, the effects of several operating parameters of the fuel cell system such as anode and cathode pressures, cell voltage, compressor voltage, compressor mass flow rate variation with respect to inlet pressure ratio, net and stack powers on the dynamic behavior of the hybrid system are investigated. The results show that the model can predict the dynamic behavior of the fuel cell system accurately and it can be used directly for any control purposes.

  5. High throughput study of fuel cell proton exchange membranes: Poly(vinylidene fluoride)/acrylic polyelectrolyte blends and nanocomposites with zirconium

    Science.gov (United States)

    Zapata B., Pedro Jose

    Sustainability is perhaps one of the most heard buzzwords in the post-20 th century society; nevertheless, it is not without a reason. Our present practices for energy supply are largely unsustainable if we consider their environmental and social impact. In view of this unfavorable panorama, alternative sustainable energy sources and conversion approaches have acquired noteworthy significance in recent years. Among these, proton exchange membrane fuel cells (PEMFCs) are being considered as a pivotal building block in the transition towards a sustainable energy economy in the 21st century. The polyelectrolyte membrane or proton exchange membrane (PEM) is a vital component, as well as a performance-limiting factor, of the PEMFC. Consequently, the development of high-performance PEM materials is of utmost importance for the advance of the PEMFC field. In this work, alternative PEM materials based on semi-interpenetrated networks from blends of poly(vinyledene fluoride) (PVDF) (inert phase) and sulfonated crosslinked acrylic polyelectrolytes (PE) (proton-conducting phase), as well as tri-phase PVDF/PE/zirconium-based composites, are studied. To alleviate the burden resulting from the vast number of possible combinations of the different precursors utilized in the preparation of the membranes (PVDF: 5x, PE: 2x, Nanoparticle: 3x), custom high-throughput (HT) screening systems have been developed for their characterization. By coupling the data spaces obtained via these systems with the appropriate statistical and data analysis tools it was found that, despite not being directly involved in the proton transport process, the inert PVDF phase plays a major role on proton conductivity. Particularly, a univocal inverse correlation between the PVDF crystalline characteristics (i.e., crystallinity and crystallite size) and melt viscosity, and membrane proton conductivity was discovered. Membranes based on highly crystalline and viscous PVDF homopolymers exhibited reduced proton

  6. Preparation and Characterization of an Alkaline Anion Exchange Membrane from Chlorinated Poly(propylene) Aminated with Branched Poly(ethyleneimine)

    Science.gov (United States)

    2013-01-01

    exchange resins and as membranes for water purification [1], Li–air batteries, and in polymer exchange membrane ( PEM ) fuel cells [2]. PEM Fuel cells show...SUBJECT TERMS Anion exchange membrane, Fuel Cell , Poly(ethyleneimine), Quaternary ammonium caton, Hydroxide Ashley M. Maes, Tara P. Pandey, Melissa...membrane Fuel cell Poly(ethyleneimine) Quaternary ammonium cation Hydroxide a b s t r a c t A new randomly crosslinked polymer is investigated

  7. HPW/MCM-41 phosphotungstic acid/mesoporous silica composites as novel proton-exchange membranes for elevated-temperature fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Shanfu [School of Mechanical and Aerospace Engineering, Nanyang Technological University Singapore (Singapore); School of Chemistry and the Environment, Beihang University Beijing (China); Wang, Deli; Jiang, San Ping; Lu, Jinlin; Zeng, Jie [School of Mechanical and Aerospace Engineering, Nanyang Technological University Singapore (Singapore); Xiang, Yan [School of Chemistry and the Environment, Beihang University Beijing (China)

    2010-03-05

    A novel inorganic proton-conducting membrane based on highly ordered MCM-41 mesoporous silica with phosphotungstic acid (HPW) nanoparticles assembled within is successfully fabricated by a vacuum-assisted impregnation method (VIM). The results of HPW impregnation by VIM and a conventional method (CIM) are compared, and the performance of the membranes in fuel cells is reported. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  8. 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)

  9. Research and Development of Proton-Exchange Membrane (PEM) Fuel Cell System for Transportation Applications: Initial Conceptual Design Report

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-30

    This report addresses Task 1.1, model development and application, and Task 1.2, vehicle mission definition. Overall intent is to produce a methanol-fueled 10-kW power source, and to evaluate electrochemical engine (ECE) use in transportation. Major achievements include development of an ECE power source model and its integration into a comprehensive power source/electric vehicle propulsion model, establishment of candidate FCV (fuel cell powered electric vehicle) mission requirements, initial FCV studies, and a candidate FCV recommendation for further study.

  10. Research and development of Proton-Exchange Membrane (PEM) fuel cell system for transportation applications: Initial conceptual design report

    Science.gov (United States)

    1993-11-01

    This report addresses Task 1.1, model development and application, and Task 1.2, vehicle mission definition. Overall intent is to produce a methanol-fueled 10-kW power source and to evaluate electrochemical engine (ECE) use in transportation. Major achievements include development of an ECE power source model and its integration into a comprehensive power source/electric vehicle propulsion model, establishment of candidate FCV (fuel cell powered electric vehicle) mission requirements, initial FCV studies, and a candidate FCV recommendation for further study.

  11. Dynamic model of oxygen starved proton exchange membrane fuel-cell using hybrid analytical-numerical method

    Science.gov (United States)

    Vijayaraghavan, Krishna; DeVaal, Jake; Narimani, Mohammad

    2015-07-01

    One of the primary life-limiting factors in PEM fuel-cells arises from performance degradation resulting from transfer (crossover) leaks. Transfer leaks result in oxygen starvation and models of fuel cells under oxygen starved conditions would allow for detection of fault inception. This paper develops a unified fuel-cell model for when the fuel-cells can either deliver power (termed driving-mode, and for when the cell absorb power (termed driven-mode) for higher leak rates. The model captures the gradient of the reactants both in the GDL and in the flow channel in addition to capturing the various electro-chemical effects. The response of the model under normal conditions is first validated for normal operation against previously published experiments. The response of the model under oxygen-starved conditions is then validated against simulated leaks in three different cell architectures: a Ballard 9-cell Mk1100 stack where hydrogen is injected into one cell, and a Ballard 10-cell Mk902 stack and 20-cell Mk903 stack where hydrogen is injected into the upstream cathode flow. Finally, the response of the model is also validated against an actual leaky Mk902 cell. The model generally agrees well with the measured cell voltage data for all the above experiments.

  12. The Role of Ion Exchange Membranes in Membrane Capacitive Deionisation

    OpenAIRE

    Hassanvand, Armineh; Wei, Kajia; Talebi, Sahar; Chen, George Q.; Kentish, Sandra E.

    2017-01-01

    Ion-exchange membranes (IEMs) are unique in combining the electrochemical properties of ion exchange resins and the permeability of a membrane. They are being used widely to treat industrial effluents, and in seawater and brackish water desalination. Membrane Capacitive Deionisation (MCDI) is an emerging, energy efficient technology for brackish water desalination in which these ion-exchange membranes act as selective gates allowing the transport of counter-ions toward carbon electrodes. This...

  13. La and Al co-doped CaMnO 3 perovskite oxides: From interplay of surface properties to anion exchange membrane fuel cell performance

    Energy Technology Data Exchange (ETDEWEB)

    Dzara, Michael J.; Christ, Jason M.; Joghee, Prabhuram; Ngo, Chilan; Cadigan, Christopher A.; Bender, Guido; Richards, Ryan M.; O' Hayre, Ryan; Pylypenko, Svitlana

    2018-01-01

    This work reports the first account of perovskite oxide and carbon composite oxygen reduction reaction (ORR) catalysts integrated into anion exchange membrane fuel cells (AEMFCs). Perovskite oxides with a theoretical stoichiometry of Ca0.9La0.1Al0.1Mn0.9O3-d are synthesized by an aerogel method and calcined at various temperatures, resulting in a set of materials with varied surface chemistry and surface area. Material composition is evaluated by X-ray diffraction, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The perovskite oxide calcined at 800 degrees C shows the importance of balance between surface area, purity of the perovskite phase, and surface composition, resulting in the highest ORR mass activity when evaluated in rotating disk electrodes. Integration of this catalyst into AEMFCs reveals that the best AEMFC performance is obtained when using composites with 30:70 perovskite oxide:carbon composition. Doubling the loading leads to an increase in the power density from 30 to 76 mW cm-2. The AEMFC prepared with a composite based on perovskite oxide and N-carbon achieves a power density of 44 mW cm-2, demonstrating an ~50% increase when compared to the highest performing composite with undoped carbon at the same loading.

  14. Pt/C catalyst degradation in proton exchange membrane fuel cells due to high-frequency potential cycling induced by switching power converters

    Science.gov (United States)

    Uno, Masatoshi; Tanaka, Koji

    Proton exchange membrane fuel cells are operated using switching power converters that produce high-frequency ripple currents. These ripples cause high-frequency potential cycling of cells, which is believed to lead premature deterioration in the electrochemical surface area (ECA) of Pt/C catalysts. The qualitative relationship between ECA losses and the frequency of potential cycling was investigated in the range of 1 Hz to 1 kHz. For frequencies higher than 100 Hz, ECA losses were comparable with those at the potential hold condition. However, for lower frequencies, ECA decreased significantly with decreasing frequency. TEM observations showed that there was marked Pt particle growth for the 1-Hz cycling condition, whereas particle size distributions at 100 Hz and potential hold conditions were comparable. The currents associated with Pt oxidation and reduction during potential cycling were also investigated at various potentials and frequencies, and the charges associated with Pt loss (Δ Q) were determined by integrating the measured current. A correlation between the ECA trend and Δ Q was observed. The results obtained in this study are considered informative for electrical engineering research, because it relates to the design of switching power converters that do not negatively influence the Pt/C catalyst durability.

  15. Highly stable and CO-tolerant Pt/Ti0.7W0.3O2 electrocatalyst for proton-exchange membrane fuel cells.

    Science.gov (United States)

    Wang, Deli; Subban, Chinmayee V; Wang, Hongsen; Rus, Eric; DiSalvo, Francis J; Abruña, Hector D

    2010-08-04

    The current materials used in proton-exchange membrane fuel cells (PEMFCs) are not sufficiently durable for commercial deployment. One of the major challenges lies in the development of an inexpensive, efficient, and CO-tolerant anode catalyst. Here we report the unique CO-tolerant property of Pt nanoparticles supported on Ti(0.7)W(0.3)O(2). The Ti(0.7)W(0.3)O(2) nanoparticles (50 nm) were synthesized via a sol-gel process and platinized using an impregnation-reduction technique. Electrochemical studies of Pt/Ti(0.7)W(0.3)O(2) show unique CO-tolerant electrocatalytic activity for hydrogen oxidation compared to commercial E-TEK PtRu/C catalysts. Differential electrochemical mass spectrometry measurements show the onset potential for CO oxidation on Pt/Ti(0.7)W(0.3)O(2) to be below 0.1 V (vs RHE). Pt/Ti(0.7)W(0.3)O(2) is a promising new anode catalyst for PEMFC applications.

  16. Synthesis and structure-activity relationship exploration of carbon-supported PtRuNi nanocomposite as a CO-tolerant electrocatalyst for proton exchange membrane fuel cells.

    Science.gov (United States)

    Liang, Yongmin; Zhang, Huamin; Tian, Zhiqun; Zhu, Xiaobing; Wang, Xiaoli; Yi, Baolian

    2006-04-20

    A carbon-supported PtRuNi nanocomposite is synthesized via a microwave-irradiated polyol plus annealing synthesis strategy. The catalyst is characterized by transmission electron microscopy, powder X-ray diffraction, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. The data are discussed with respect to those for the carbon-supported PtRu nanocomposite prepared following the same way. The characterizations show that the inclusion of Ni in the PtRu system has only a small effect on the particle size, the structure, and the compositional homogeneity. CO-stripping voltammetry and measurements on the single proton exchange membrane fuel cells show that the PtRuNi/C catalyst has an improved activity for CO(ads) electro-oxidation. An accelerated durability test on the catalyst exhibits insignificant loss of activity in acidic media. On the basis of the exploration of the structure-activity relationship, a mechanism for the improved performance of the catalyst is proposed. It is suggested that the improved CO-tolerant performance of the PtRuNi/C nanocomposite should be related to the hydrogen spillover on the catalyst surface, the enhanced oxidation of CO(ads) by nickel hydroxides, and the high proton and electronic conductivity of the hydroxides. The nickel hydroxide passivated surface and/or anchoring of metallic nickel in the platinum lattice may contribute to the durability of the catalyst in acid solution.

  17. Insights into the role of wettability in cathode catalyst layer of proton exchange membrane fuel cell; pore scale immiscible flow and transport processes

    Science.gov (United States)

    Fathi, H.; Raoof, A.; Mansouri, S. H.

    2017-05-01

    The production of liquid water in cathode catalyst layer, CCL, is a significant barrier to increase the efficiency of proton exchange membrane fuel cell. Here we present, for the first time, a direct three-dimensional pore-scale modelling to look at the complex immiscible two-phase flow in CCL. After production of the liquid water at the surface of CCL agglomerates due to the electrochemical reactions, water spatial distribution affects transport of oxygen through the CCL as well as the rate of reaction at the agglomerate surfaces. To explore the wettability effects, we apply hydrophilic and hydrophobic properties using different surface contact angles. Effective diffusivity is calculated under several water saturation levels. Results indicate larger diffusive transport values for hydrophilic domain compared to the hydrophobic media where the liquid water preferentially floods the larger pores. However, hydrophobic domain showed more available surface area and higher oxygen consumption rate at the reaction sites under various saturation levels, which is explained by the effect of wettability on pore-scale distribution of water. Hydrophobic domain, with a contact angle of 150, reveals efficient water removal where only 28% of the pore space stays saturated. This condition contributes to the enhanced available reaction surface area and oxygen diffusivity.

  18. La and Al co-doped CaMnO3 perovskite oxides: From interplay of surface properties to anion exchange membrane fuel cell performance

    Science.gov (United States)

    Dzara, Michael J.; Christ, Jason M.; Joghee, Prabhuram; Ngo, Chilan; Cadigan, Christopher A.; Bender, Guido; Richards, Ryan M.; O'Hayre, Ryan; Pylypenko, Svitlana

    2018-01-01

    This work reports the first account of perovskite oxide and carbon composite oxygen reduction reaction (ORR) catalysts integrated into anion exchange membrane fuel cells (AEMFCs). Perovskite oxides with a theoretical stoichiometry of Ca0.9La0.1Al0.1Mn0.9O3-δ are synthesized by an aerogel method and calcined at various temperatures, resulting in a set of materials with varied surface chemistry and surface area. Material composition is evaluated by X-ray diffraction, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The perovskite oxide calcined at 800 °C shows the importance of balance between surface area, purity of the perovskite phase, and surface composition, resulting in the highest ORR mass activity when evaluated in rotating disk electrodes. Integration of this catalyst into AEMFCs reveals that the best AEMFC performance is obtained when using composites with 30:70 perovskite oxide:carbon composition. Doubling the loading leads to an increase in the power density from 30 to 76 mW cm-2. The AEMFC prepared with a composite based on perovskite oxide and N-carbon achieves a power density of 44 mW cm-2, demonstrating an ∼50% increase when compared to the highest performing composite with undoped carbon at the same loading.

  19. Design of Incremental Conductance Sliding Mode MPPT Control Applied by Integrated Photovoltaic and Proton Exchange Membrane Fuel Cell System under Various Operating Conditions for BLDC Motor

    Directory of Open Access Journals (Sweden)

    Jehun Hahm

    2015-01-01

    Full Text Available This paper proposes an integrated photovoltaic (PV and proton exchange membrane fuel cell (PEMFC system for continuous energy harvesting under various operating conditions for use with a brushless DC motor. The proposed scheme is based on the incremental conductance (IncCond algorithm combined with the sliding mode technique. Under changing atmospheric conditions, the energy conversion efficiency of a PV array is very low, leading to significant power losses. Consequently, increasing efficiency by means of maximum power point tracking (MPPT is particularly important. To manage such a hybrid system, control strategies need to be established to achieve the aim of the distributed system. Firstly, a Matlab/Simulink based model of the PV and PEMFC is developed and validated, as well as the incremental conductance sliding (ICS MPPT technique; then, different MPPT algorithms are employed to control the PV array under nonuniform temperature and insolation conditions, to study these algorithms effectiveness under various operating conditions. Conventional techniques are easy to implement but produce oscillations at MPP. Compared to these techniques, the proposed technique is more efficient; it produces less oscillation at MPP in the steady state and provides more precise tracking.

  20. 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

    The overall objective of this project was the development and evaluation of novel hydrocarbon fuel cell (FC) membranes that possess high temperature performance and long term chemical/mechanical durability in proton exchange membrane (PEM) fuel cells (FC). The major research theme was synthesis of aromatic hydrocarbon polymers of the poly(arylene ether sulfone) (PAES) type containing sulfonic acid groups tethered to the backbone via perfluorinated alkylene linkages and in some cases also directly attached to the phenylene groups along the backbone. Other research themes were the use of nitrogen-based heterocyclics instead of acid groups for proton conduction, which provides high temperature, low relative humidity membranes with high mechanical/thermal/chemical stability and pendant moieties that exhibit high proton conductivities in the absence of water, and synthesis of block copolymers consisting of a proton conducting block coupled to poly(perfluorinated propylene oxide) (PFPO) blocks. Accomplishments of the project were as follows: 1) establishment of a vertically integrated program of synthesis, characterization, and evaluation of FC membranes, 2) establishment of benchmark membrane performance data based on Nafion for comparison to experimental membrane performance, 3) development of a new perfluoroalkyl sulfonate monomer, N,N-diisopropylethylammonium 2,2-bis(p-hydroxyphenyl) pentafluoropropanesulfonate (HPPS), 4) synthesis of random and block copolymer membranes from HPPS, 5) synthesis of block copolymer membranes containing high-acid-concentration hydrophilic blocks consisting of HPPS and 3,3'-disulfonate-4,4'-dichlorodiphenylsulfone (sDCDPS), 6) development of synthetic routes to aromatic polymer backbones containing pendent 1H-1,2,3-triazole moieties, 7) development of coupling strategies to create phase-separated block copolymers between hydrophilic sulfonated prepolymers and commodity polymers such as PFPO, 8) establishment of basic

  1. Method of fabricating electrode catalyst layers with directionally oriented carbon support for proton exchange membrane fuel cell

    Science.gov (United States)

    Liu, Di-Jia; Yang, Junbing

    2010-07-20

    A method of making a membrane electrode assembly (MEA) having an anode and a cathode and a proton conductive membrane there between. A bundle of longitudinally aligned carbon nanotubes with a catalytically active transition metal incorporated in the nanotubes forms at least one portion of the MEA and is in contact with the membrane. A combination selected from one or more of a hydrocarbon and an organometallic compound containing an catalytically active transition metal and a nitrogen containing compound and an inert gas and a reducing gas is introduced into a first reaction zone maintained at a first reaction temperature for a time sufficient to vaporize material therein. The vaporized material is transmitted to a second reaction zone maintained at a second reaction temperature for a time sufficient to grow longitudinally aligned carbon nanotubes with a catalytically active transition metal incorporated throughout the nanotubes. The nanotubes are in contact with a portion of the MEA at production or being positioned in contact thereafter. Methods of forming a PEMFC are also disclosed.

  2. Final report on LDRD project : elucidating performance of proton-exchange-membrane fuel cells via computational modeling with experimental discovery and validation.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chao Yang (Pennsylvania State University, University Park, PA); Pasaogullari, Ugur (Pennsylvania State University, University Park, PA); Noble, David R.; Siegel, Nathan P.; Hickner, Michael A.; Chen, Ken Shuang

    2006-11-01

    In this report, we document the accomplishments in our Laboratory Directed Research and Development project in which we employed a technical approach of combining experiments with computational modeling and analyses to elucidate the performance of hydrogen-fed proton exchange membrane fuel cells (PEMFCs). In the first part of this report, we document our focused efforts on understanding water transport in and removal from a hydrogen-fed PEMFC. Using a transparent cell, we directly visualized the evolution and growth of liquid-water droplets at the gas diffusion layer (GDL)/gas flow channel (GFC) interface. We further carried out a detailed experimental study to observe, via direct visualization, the formation, growth, and instability of water droplets at the GDL/GFC interface using a specially-designed apparatus, which simulates the cathode operation of a PEMFC. We developed a simplified model, based on our experimental observation and data, for predicting the onset of water-droplet instability at the GDL/GFC interface. Using a state-of-the-art neutron imaging instrument available at NIST (National Institute of Standard and Technology), we probed liquid-water distribution inside an operating PEMFC under a variety of operating conditions and investigated effects of evaporation due to local heating by waste heat on water removal. Moreover, we developed computational models for analyzing the effects of micro-porous layer on net water transport across the membrane and GDL anisotropy on the temperature and water distributions in the cathode of a PEMFC. We further developed a two-phase model based on the multiphase mixture formulation for predicting the liquid saturation, pressure drop, and flow maldistribution across the PEMFC cathode channels. In the second part of this report, we document our efforts on modeling the electrochemical performance of PEMFCs. We developed a constitutive model for predicting proton conductivity in polymer electrolyte membranes and compared

  3. Fault detection and isolation of high temperature proton exchange membrane fuel cell stack under the influence of degradation

    DEFF Research Database (Denmark)

    Jeppesen, Christian; Araya, Samuel Simon; Sahlin, Simon Lennart

    2017-01-01

    This study proposes a data-drive impedance-based methodology for fault detection and isolation of low and high cathode stoichiometry, high CO concentration in the anode gas, high methanol vapour concentrations in the anode gas and low anode stoichiometry, for high temperature PEM fuel cells...... methanol vapour concentration in the anode gas fault, which was found to be difficult to distinguish from a normal operational data. The achieved accuracy for faults related to CO pollution, anode- and cathode stoichiometry is 100% success rate. Overall global accuracy on the test data is 94.6%....

  4. Proton exchange membrane fuel cells modeling: A review of the last ten years results of the Fuel Cell Research Center-IEEF

    OpenAIRE

    Maher A.R. Sadiq Al-Baghdadi

    2017-01-01

    Fuel cell technology is expected to play an important role in meeting the growing demand for distributed power generation. In an ongoing effort to meet increasing energy demand and to preserve the global environment, the development of energy systems with readily available fuels, high efficiency and minimal environmental impact is urgently required. A fuel cell system is expected to meet such demands because it is a chemical power generation device, which converts the chemical energy of a ren...

  5. Three dimensional proton exchange membrane fuel cell cathode model using a modified agglomerate approach based on discrete catalyst particles

    Science.gov (United States)

    Cetinbas, Firat C.; Advani, Suresh G.; Prasad, Ajay K.

    2014-03-01

    The spherical agglomerate model represents the most detailed description of the PEM fuel cell catalyst layer as it accounts for both micro and macroscale transport phenomena. The usual approach with the classical spherical agglomerate model is to couple the homogenous mixture assumption for the agglomerate core to its idealized spherical geometry to obtain an analytical solution which is easily incorporated within a macroscale model. In this study, we incorporate numerical results from a modified agglomerate model based on discrete platinum particles [33] to create a more physically realistic 3D macroscale model for the PEM fuel cell cathode catalyst layer. Results from the 3D cathode model based on the modified particle approach are compared with the classical model and the macro-homogenous model. We find that, similar to the classical approach, the modified 3D model is able to reproduce previously reported trends for reactant, reaction rate, and overpotential distributions, whereas the macro-homogenous model fails to predict mass transport limitations properly. It is also shown that, unlike the classical approach, the modified 3D model is able to accurately predict the effect of Pt loading in the diffusion-loss region.

  6. Experimental study of proton exchange membrane fuel cell; Estudo experimental de uma celula a combustivel de membrana polimerica

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, Luis Evelio Garcia; Oliveira, Amir Antonio Martins [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica], e-mail: evelio@labcet.ufsc.br, e-mail: amirol@emc.ufsc.br

    2006-07-01

    Here we present a thermodynamic and chemical kinetic analysis of the methane steam reforming for production of 5 kw of electrical power in a PEM fuel cell. The equilibrium analysis is based on the method of element potentials to find the state of minimum Gibbs free energy for the system and provides the equilibrium concentration of the reforming products. The objective of this analysis is to obtain the range of reforming temperature, pressure and steam-methane molar ratio that results in maximum hydrogen production subjected to low carbon monoxide production and negligible coke formation. The thermal analysis provides the heat transfer rates associated with the individual processes of steam production, gas-phase superheating and reforming necessary to produce 5 kw of electrical power in a PEM fuel cell and allows for the calculation of thermal efficiencies. Then, the chemical reaction pathways for hydrogen production in steam reforming are discussed and the available chemical, adsorption and equilibrium constants are analyzed in terms of thermodynamic consistency. This analysis provides the framework for the reactor sizing and for establishing the adequate operation conditions. (author)

  7. Electricity generation using an air-cathode single chamber microbial fuel cell in the presence and absence of a proton exchange membrane.

    Science.gov (United States)

    Liu, Hong; Logan, Bruce E

    2004-07-15

    Microbial fuel cells (MFCs) are typically designed as a two-chamber system with the bacteria in the anode chamber separated from the cathode chamber by a polymeric proton exchange membrane (PEM). Most MFCs use aqueous cathodes where water is bubbled with air to provide dissolved oxygen to electrode. To increase energy output and reduce the cost of MFCs, we examined power generation in an air-cathode MFC containing carbon electrodes in the presence and absence of a polymeric proton exchange membrane (PEM). Bacteria present in domestic wastewater were used as the biocatalyst, and glucose and wastewater were tested as substrates. Power density was found to be much greater than typically reported for aqueous-cathode MFCs, reaching a maximum of 262 +/- 10 mW/m2 (6.6 +/- 0.3 mW/L; liquid volume) using glucose. Removing the PEM increased the maximum power density to 494 +/- 21 mW/m2 (12.5 +/- 0.5 mW/L). Coulombic efficiency was 40-55% with the PEM and 9-12% with the PEM removed, indicating substantial oxygen diffusion into the anode chamber in the absence of the PEM. Power output increased with glucose concentration according to saturation-type kinetics, with a half saturation constant of 79 mg/L with the PEM-MFC and 103 mg/L in the MFC without a PEM (1000 omega resistor). Similar results on the effect of the PEM on power density were found using wastewater, where 28 +/- 3 mW/m2 (0.7 +/- 0.1 mW/L) (28% Coulombic efficiency) was produced with the PEM, and 146 +/- 8 mW/m2 (3.7 +/- 0.2 mW/L) (20% Coulombic efficiency) was produced when the PEM was removed. The increase in power output when a PEM was removed was attributed to a higher cathode potential as shown by an increase in the open circuit potential. An analysis based on available anode surface area and maximum bacterial growth rates suggests that mediatorless MFCs may have an upper order-of-magnitude limit in power density of 10(3) mW/m2. A cost-effective approach to achieving power densities in this range will likely

  8. A pore-scale model for the cathode electrode of a proton exchange membrane fuel cell by lattice Boltzmann method

    Energy Technology Data Exchange (ETDEWEB)

    Molaeimanesh, Gholam Reza; Akbari, Mohammad Hadi [Shiraz University, Shiraz (Iran, Islamic Republic of)

    2015-03-15

    A pore-scale model based on the lattice Boltzmann method (LBM) is proposed for the cathode electrode of a PEM fuel cell with heterogeneous and anisotropic porous gas diffusion layer (GDL) and interdigitated flow field. An active approach is implemented to model multi-component transport in GDL, which leads to enhanced accuracy, especially at higher activation over-potentials. The core of the paper is the implementation of an electrochemical reaction with an active approach in a multi-component lattice Boltzmann model for the first time. After model validation, the capability of the presented model is demonstrated through a parametric study. Effects of activation over-potential, pressure differential between inlet and outlet gas channels, land width to channel width ratio, and channel width are investigated. The results show the significant influence of GDL microstructure on the oxygen distribution and current density profile.

  9. Characterization of Anion Exchange Membrane Containing Epoxy Ring and C–Cl Bond Quaternized by Various Amine Groups for Application in Fuel Cells

    Directory of Open Access Journals (Sweden)

    Sung Kuk Jeong

    2015-07-01

    Full Text Available Anion exchange membranes were synthesized from different compositions of glycidyl methacrylate (GMA and vinylbenzyl chloride (VBC, with constant content of divinyl benzene (DVB by radical polymerization using benzoyl peroxide (BPO on non-woven polyethylene terephthalate (PET substrate. Polymerized membranes were then quaternized by soaking in trimethylamine (TMA, triethylamine (TEA, tripropylamine (TPA, and 1,4-diazabicyclo [2.2.2] octane (DABCO. Characteristics of membranes were confirmed by Fourier transform infrared spectroscopy, water uptake, ion exchange capacity, ion conductivity, thermal, and alkaline stability. The results revealed that membranes quaternized by TPA and DABCO showed high affinity when GMA content was 15 wt% and 75 wt%, respectively. IEC and ion conductivity of membranes quaternized by TPA were 1.34 meq·g−1 and 0.022 S·cm−1 (at 60 °C, respectively. IEC and ion conductivity of membranes were quaternized by DABCO were 1.34 meq·g−1 and 0.021 S·cm−1 (at 60 °C, respectively. The results indicate that the membrane containing GMA 15 wt% quaternized by TPA showed the highest thermal stability among membranes and exhibited high ion conductivity compared to existing researches using GMA, VBC, and DVB monomers.

  10. Fault detection and isolation of high temperature proton exchange membrane fuel cell stack under the influence of degradation

    Science.gov (United States)

    Jeppesen, Christian; Araya, Samuel Simon; Sahlin, Simon Lennart; Thomas, Sobi; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2017-08-01

    This study proposes a data-drive impedance-based methodology for fault detection and isolation of low and high cathode stoichiometry, high CO concentration in the anode gas, high methanol vapour concentrations in the anode gas and low anode stoichiometry, for high temperature PEM fuel cells. The fault detection and isolation algorithm is based on an artificial neural network classifier, which uses three extracted features as input. Two of the proposed features are based on angles in the impedance spectrum, and are therefore relative to specific points, and shown to be independent of degradation, contrary to other available feature extraction methods in the literature. The experimental data is based on a 35 day experiment, where 2010 unique electrochemical impedance spectroscopy measurements were recorded. The test of the algorithm resulted in a good detectability of the faults, except for high methanol vapour concentration in the anode gas fault, which was found to be difficult to distinguish from a normal operational data. The achieved accuracy for faults related to CO pollution, anode- and cathode stoichiometry is 100% success rate. Overall global accuracy on the test data is 94.6%.

  11. Radiolytic Preparation of Electrocatalysts with Pt-Co and Pt-Sn Nanoparticles for a Proton Exchange Membrane Fuel Cell

    Directory of Open Access Journals (Sweden)

    Sang Kyum Kim

    2014-01-01

    Full Text Available Nanosized Pt-Sn/VC and Pt-Co/VC electrocatalysts were prepared by a one-step radiation-induced reduction (30 kGy process using distilled water as the solvent and Vulcan XC72 as the supporting material. While the Pt-Co/VC electrodes were compared with Pt/VC (40 wt%, HiSpec 4000, in terms of their electrocatalytic activity towards the oxidation of H2, the Pt-Co/VC electrodes were evaluated in terms of their activity towards the hydrogen oxidation reaction (HOR and compared with Pt/VC (40 wt%, HiSpec 4000, Pt-Co/VC, and Pt-Sn/VC in a single cell. Additionally, the prepared electrocatalyst samples (Pt-Co/VC and Pt-Sn/VC were characterized by transmission electron microscopy (TEM, scanning electron microscope (SEM, thermogravimetric analysis (TGA, X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, electrochemical surface area (ECSA, and fuel cell polarization performance.

  12. Pt and PtRu catalyst bilayers increase efficiencies for ethanol oxidation in proton exchange membrane electrolysis and fuel cells

    Science.gov (United States)

    Altarawneh, Rakan M.; Pickup, Peter G.

    2017-10-01

    Polarization curves, product distributions, and reaction stoichiometries have been measured for the oxidation of ethanol at anodes consisting of Pt and PtRu bilayers and a homogeneous mixture of the two catalysts. These anode structures all show synergies between the two catalysts that can be attributed to the oxidation of acetaldehyde produced at the PtRu catalyst by the Pt catalyst. The use of a PtRu layer over a Pt layer produces the strongest effect, with higher currents than a Pt on PtRu bilayer, mixed layer, or either catalyst alone, except for Pt at high potentials. Reaction stoichiometries (average number of electrons transferred per ethanol molecule) were closer to the values for Pt alone for both of the bilayer configurations but much lower for PtRu and mixed anodes. Although Pt alone would provide the highest overall fuel cell efficiency at low power densities, the PtRu on Pt bilayer would provide higher power densities without a significant loss of efficiency. The origin of the synergy between the Pt and PtRu catalysts was elucidated by separation of the total current into the individual components for generation of carbon dioxide and the acetaldehyde and acetic acid byproducts.

  13. Development and testing of the proton exchange membrane fuel cell (PEMFC) for stationary generation; Desenvolvimento e ensaios de uma celula a combustivel de polimero solido (PEMFC) para geracao estacionaria

    Energy Technology Data Exchange (ETDEWEB)

    Ellern, Mara; Boccuzzi, Cyro Vicente [ELETROPAULO, Sao Caetano, SP (Brazil)], e-mail: mara.ellern@aes.com; Ett, Gerhard; Saiki, Gerson Yukio; Janolio, Gilberto [ELECTROCELL, Sao Paulo, SP (Brazil); Jardini, Jose Antonio [Universidade de Sao Paulo (USP), SP (Brazil)

    2004-07-01

    PEM (Proton Exchange Membrane) fuel cell uses a simple chemical reaction to combine hydrogen and oxygen into water, producing electric current in the process. It works something like reversed electrolysis: at the anode, hydrogen molecules give up electrons, forming hydrogen ions (this process is made possible by the platinum catalyst). The proton exchange membrane allows protons to flow through, but not electrons. As a result, the hydrogen ions flow directly through the proton exchange membrane to the cathode, while the electrons flow through an external circuit. As they travel to the cathode through the external circuit, the electrons produce electrical current. At the cathode, the electrons and hydrogen ions combine with oxygen to form water. In a fuel cell, hydrogen's natural tendency to oxidize and form water produces electricity and useful work. No pollution is produced and the only byproducts are water and heat. The huge advance on materials development combined with the growth demand of lower impact on environment is placing the fuel cells on the top of the most promising technologies world-wide. They are becoming in medium term feasible alternatives for energy generators up to energy plants of few MW. (author)

  14. Research and development of Proton-Exchange-Membrane (PEM) fuel cell system for transportation applications. Fuel cell infrastructure and commercialization study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-01

    This paper has been prepared in partial fulfillment of a subcontract from the Allison Division of General Motors under the terms of Allison`s contract with the U.S. Department of Energy (DE-AC02-90CH10435). The objective of this task (The Fuel Cell Infrastructure and Commercialization Study) is to describe and prepare preliminary evaluations of the processes which will be required to develop fuel cell engines for commercial and private vehicles. This report summarizes the work undertaken on this study. It addresses the availability of the infrastructure (services, energy supplies) and the benefits of creating public/private alliances to accelerate their commercialization. The Allison prime contract includes other tasks related to the research and development of advanced solid polymer fuel cell engines and preparation of a demonstration automotive vehicle. The commercialization process starts when there is sufficient understanding of a fuel cell engine`s technology and markets to initiate preparation of a business plan. The business plan will identify each major step in the design of fuel cell (or electrochemical) engines, evaluation of the markets, acquisition of manufacturing facilities, and the technical and financial resources which will be required. The process will end when one or more companies have successfully developed and produced fuel cell engines at a profit. This study addressed the status of the information which will be required to prepare business plans, develop the economic and market acceptance data, and to identify the mobility, energy and environment benefits of electrochemical or fuel cell engines. It provides the reader with information on the status of fuel cell or electrochemical engine development and their relative advantages over competitive propulsion systems. Recommendations and descriptions of additional technical and business evaluations that are to be developed in more detail in Phase II, are included.

  15. Development and design of experiments optimization of a high temperature proton exchange membrane fuel cell auxiliary power unit with onboard fuel processor

    Science.gov (United States)

    Karstedt, Jörg; Ogrzewalla, Jürgen; Severin, Christopher; Pischinger, Stefan

    In this work, the concept development, system layout, component simulation and the overall DOE system optimization of a HT-PEM fuel cell APU with a net electric power output of 4.5 kW and an onboard methane fuel processor are presented. A highly integrated system layout has been developed that enables fast startup within 7.5 min, a closed system water balance and high fuel processor efficiencies of up to 85% due to the recuperation of the anode offgas burner heat. The integration of the system battery into the load management enhances the transient electric performance and the maximum electric power output of the APU system. Simulation models of the carbon monoxide influence on HT-PEM cell voltage, the concentration and temperature profiles within the autothermal reformer (ATR) and the CO conversion rates within the watergas shift stages (WGSs) have been developed. They enable the optimization of the CO concentration in the anode gas of the fuel cell in order to achieve maximum system efficiencies and an optimized dimensioning of the ATR and WGS reactors. Furthermore a DOE optimization of the global system parameters cathode stoichiometry, anode stoichiometry, air/fuel ratio and steam/carbon ratio of the fuel processing system has been performed in order to achieve maximum system efficiencies for all system operating points under given boundary conditions.

  16. Effect of heat treatment on the activity and stability of carbon supported PtMo alloy electrocatalysts for hydrogen oxidation in proton exchange membrane fuel cells

    Science.gov (United States)

    Hassan, Ayaz; Carreras, Alejo; Trincavelli, Jorge; Ticianelli, Edson Antonio

    2014-02-01

    The effect of heat treatment on the activity, stability and CO tolerance of PtMo/C catalysts was studied, due to their applicability in the anode of proton exchange membrane fuel cells (PEMFCs). To this purpose, a carbon supported PtMo (60:40) alloy electrocatalyst was synthesized by the formic acid reduction method, and samples of this catalyst were heat-treated at various temperatures ranging between 400 and 700 °C. The samples were characterized by temperature programmed reduction (TPR), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Transmission electron microscopy (TEM), X-ray absorption spectroscopy (XAS), cyclic voltammetry (CV), scanning electron microscopy (SEM) and wavelength dispersive X-ray spectroscopy (WDS). Cyclic voltammetry was used to study the stability, and polarization curves were used to investigate the performance of all materials as CO tolerant anode on a PEM single cell text fixture. The catalyst treated at 600 °C, for which the average crystallite size was 16.7 nm, showed the highest hydrogen oxidation activity in the presence of CO, giving an overpotential induced by CO contamination of 100 mV at 1 Acm-2. This catalyst also showed a better stability up to 5000 potential cycles of cyclic voltammetry, as compared to the untreated catalyst. CV, SEM and WDS results indicated that a partial dissolution of Mo and its migration/diffusion from the anode to the cathode occurs during the single cell cycling. Polarization results showed that the catalytic activity and the stability can be improved by a heat treatment, in spite of a growth of the catalyst particles.

  17. Improved stability of TiO{sub 2} modified Ru{sub 85}Se{sub 15}/C electrocatalyst for proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ting; Ma, Yuanwei; Jin, Hong [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Zhang, Huamin; Zhong, Hexiang; Zhang, Yining [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)

    2010-12-15

    The electrocatalytic stability of the carbon supported Ru{sub 85}Se{sub 15} nanoparticles has been improved by the modification of titanium dioxide for proton exchange membrane fuel cells (PEMFCs). Transmission electron microscopy (TEM), X-ray diffraction (XRD) measurements and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) are applied for characterizing Ru{sub 85}Se{sub 15}/C and titanium dioxide modified Ru{sub 85}Se{sub 15}/C (Ru{sub 85}Se{sub 15}/TiO{sub 2}/C) electrocatalysts. Electrochemical measurements and single cell tests are conducted for the evaluation of the electrocatalysts. The results indicate that Ru{sub 85}Se{sub 15}/TiO{sub 2}/C electrocatalyst, presenting similar initial oxygen reduction reaction (ORR) activity with Ru{sub 85}Se{sub 15}/C, reveals better electrochemical stability. The final potential of Ru{sub 85}Se{sub 15}/TiO{sub 2}/C is 137 mV higher than that of Ru{sub 85}Se{sub 15}/C at 2 mA cm{sup -2} after the electrochemical durability test. Moreover, in the single cell stability test Ru{sub 85}Se{sub 15}/TiO{sub 2}/C also shows comparable initial performance with Ru{sub 85}Se{sub 15}/C, but better final performance. Therefore, the Ru{sub 85}Se{sub 15}/C is expected to be used as an effective cathode electrocatalyst for PEMFCs by TiO{sub 2} modification on the carbon support. (author)

  18. Experimental study of clamping effects on the performances of a single proton exchange membrane fuel cell and a 10-cell stack

    Science.gov (United States)

    Wen, Chih-Yung; Lin, Yu-Sheng; Lu, Chien-Heng

    The contact pressure distribution is known to have significant influences on the contact ohmic resistance, porosity of gas diffusion layers (GDLs) and performance of the proton exchange membrane fuel cell (PEMFC) consequently. This work experimentally investigated the effects of various combinations of bolt configuration and clamping torque on the corresponding contact pressure distributions and performances of a single PEMFC and a 10-cell stack. The pressure-sensitive films (FUJI-FILM I&I) were used to visualize the contact pressure distributions under three different clamping torques and three different bolt configurations in the experiments. The importance of the proper stacking design was clearly demonstrated by these contact pressure images. The mean value and the fluctuation intensity of the contact pressure were extracted statistically from the data of pressure-sensitive films. A non-dimensional pressure fluctuation intensity, which indicates the relative dispersion to its mean value, was proposed to gauge the uniformity of the contact pressure distribution, similar to the definition of the turbulence intensity in fluid mechanics. The experimental results showed that, for the single cell under the current experiment conditions, the larger mean contact pressure tends to yield the higher maximum power, regardless of the bolt configuration and the applied torque. The uniformity of the contact pressure distribution, the ohmic resistance and the mass transport limit current had highly linear correlations with the mean contact pressure. In the case of the 10-cell stack, the effects of various combinations of bolt configuration and clamping torque on its performance and the mass transport limit current could not be reflected by the stack mean contact pressure only. Increasing the mean contact pressure improved the uniformity of the contact pressure distribution and reduced the contact ohmic resistance, in general. However, the maximum power did not increase

  19. Cross-linked polybenzimidazole membranes for high temperature proton exchange membrane fuel cells with dichloromethyl phosphinic acid as a cross-linker

    DEFF Research Database (Denmark)

    Noye, Pernille; Li, Qingfeng; Pan, Chao

    2008-01-01

    Phosphoric acid doped polybenzimidazole (PBI) membranes have been covalently cross-linked with dichloromethyl phosphinic acid (DCMP). FT-IR measurements showed new bands originating from bonds between the hydrogen bearing nitrogen in the imidazole group of PBI and the CH2 group in DCMP. The produ...

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

    Indian Academy of Sciences (India)

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

  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. Anion exchange membrane design for reverse electrodialysis

    NARCIS (Netherlands)

    Güler, E.

    2014-01-01

    Reverse electrodialysis (RED) is a clean, sustainable technology for the generation of energy from the mixing of solutions with different salinity. The ion exchange membranes are key elements in RED. Especially the study of anion exchange membranes is crucial since limited research has been done

  3. Local potential evolutions during proton exchange membrane fuel cell operation with dead-ended anode - Part I: Impact of water diffusion and nitrogen crossover

    Science.gov (United States)

    Abbou, S.; Dillet, J.; Maranzana, G.; Didierjean, S.; Lottin, O.

    2017-02-01

    Operating a PEMFC with a dead-ended anode may lead to local fuel-starvation because of water and possibly nitrogen accumulation in the anode compartment. In previous works, we used a segmented linear cell with reference electrodes to monitor simultaneously the local potentials and current densities during dead-ended anode operation. The results indicated that water transport as well as nitrogen crossover through the membrane were most probably the two key factors governing fuel starvation. In this first from a set of two papers, we evaluated with more details the contributions of nitrogen crossover and water transport to hydrogen starvation. To assess nitrogen contribution, the fuel cell cathode compartment was first supplied with pure oxygen instead of air. The results showed that in the absence of nitrogen (in the cathode side) the fuel starvation was much slower than with air, suggesting that nitrogen contribution cannot be neglected. On the other hand, the contribution of water flooding to hydrogen starvation was investigated by using different cooling temperature on the cathode and anode sides in order to drive water toward the colder plate. The results showed that with a colder anode side, fuel starvation was faster. In the opposite case of a hotter anode plate, water accumulation in the anode compartment was limited, nitrogen crossover through the membrane was the main reason for hydrogen starvation in this case. To fully assess the impact of the thermal configurations on membrane-electrode assembly (MEA) degradation, aging protocols with a dead-ended anode and a fixed closing time were also performed. The results showed that operation with a hotter anode could help to limit significantly cathode ElectroChemical Surface Area (ECSA) losses along the cell area and performance degradation induced by hydrogen starvation.

  4. In-plane structuring of proton exchange membrane fuel cell cathodes: Effect of ionomer equivalent weight structuring on performance and current density distribution

    Science.gov (United States)

    Herden, Susanne; Riewald, Felix; Hirschfeld, Julian A.; Perchthaler, Markus

    2017-07-01

    Within the active area of a fuel cell inhomogeneous operating conditions occur, however, state of the art electrodes are homogenous over the complete active area. This study uses current density distribution measurements to analyze which ionomer equivalent weight (EW) shows locally the highest current densities. With this information a segmented cathode electrode is manufactured by decal transfer. The segmented electrode shows better performance especially at high current densities compared to homogenous electrodes. Furthermore this segmented catalyst coated membrane (CCM) performs optimal in wet as well as dry conditions, both operating conditions arise in automotive fuel cell applications. Thus, cathode electrodes with an optimized ionomer EW distribution might have a significant impact on future automotive fuel cell development.

  5. Study of coupled transport and its effect on different electrochemical systems: Implications in high temperature energy storage batteries and proton exchange membrane fuel cells

    Science.gov (United States)

    Parthasarathy, Preethy

    Coupled transport is studied on two electrochemical systems: Na-ZnCl 2 batteries and Proton Exchange Membrane Fuel Cells (PEMFC). The energy storage system of interest here is based on sodium β"-alumina solid electrolyte (BASE): Na/BASE/ZnCl2. BASE is an excellent Na+ conductor with a very high conductivity at 300°C. Its high Na+ ion conductivity and high stability are the principal reasons for its application in electrochemical storage systems. A novel vapor phase process was invented facilitating the fabrication of high strength and moisture/CO 2 resistant BASE. A two-phase composite of alumiNa+YSZ is formed by sintering and exposed to Na2O vapor, keeping the activity of Na2O lower than that in NaAlO2. This prevents the formation of hygroscopic NaAlO2 at the grain boundaries. A thin layer of β"-alumina is formed on the surface upon exposure. Further reaction occurs by transporting Na+ ions through the formed β"-alumina and a parallel transport of O2- ions through YSZ. This occurs by a coupled transport of Na+ through β"-alumina and O 2- ions through YSZ, thus expediting the process. The second electrochemical system of interest is PEMFC. The degradation mechanism of catalysts is studied using inexpensive copper particles. The mechanism of growth involves a coupled transport of Cu2+ through the aqueous medium and an electron transport through the direct particle-to-particle contact. Effect of applied stress on coarsening of platinum was also investigated. Two platinum wires/foils were immersed in a PtCl4+DMSO (Dimethyl sulfoxide) solution. A tensile load was applied to one wire/foil and the other one was left load-free. The wire/foil subjected to a tensile load became cathodic with respect to the unstressed wire/foil. Thus, under a tensile stress, the chemical potential of Pt decreases. This result suggests design strategies for core-shell catalysts used in PEMFCs: stable core-shell catalysts for PEMFC with Pt shell should be designed such that the shell is

  6. Platinum-cobalt catalysts for the oxygen reduction reaction in high temperature proton exchange membrane fuel cells - Long term behavior under ex-situ and in-situ conditions

    Science.gov (United States)

    Schenk, Alexander; Grimmer, Christoph; Perchthaler, Markus; Weinberger, Stephan; Pichler, Birgit; Heinzl, Christoph; Scheu, Christina; Mautner, Franz-Andreas; Bitschnau, Brigitte; Hacker, Viktor

    2014-11-01

    Platinum cobalt catalysts (Pt-Co) have attracted much interest as cathode catalysts for proton exchange membrane fuel cells (PEMFCs) due to their high activity toward oxygen reduction reaction (ORR). Many of the reported catalysts show outstanding performance in ex-situ experiments. However, the laborious synthesis protocols of these Pt-Co catalysts disable an efficient and economic production of membrane electrode assemblies (MEAs). We present an economic, flexible and continuous Pt-M/C catalyst preparation method as part of a large scale membrane electrode assembly manufacturing. In comparison, the as-prepared Pt-Co/C based high temperature (HT)-PEM MEA showed an equal performance to a commercially available HT-PEM MEA during 600 h of operation under constant load, although the commercial one had a significantly higher Pt loading at the cathode.

  7. Applications with proton exchange membrane (PEM) fuel cells for a de-regulated market place; Applications avec des piles a combustible a membrane echangeuse de protons (PEM) pour une place sur le marche deregule

    Energy Technology Data Exchange (ETDEWEB)

    Kohlstruck, B. [Alstom Energietechnik GmbH (Germany)

    2000-07-01

    The electric utility is in a period of rapid change. The deregulation and restructuring of the utilities will lead to massive industry change-with new structures of energy supply. This market's change creates a significant opportunity for fuel cells as on-site generation solutions. This paper considers the applications of Proton Exchange Membrane Fuel Cells (PEMFC) recent development, in particular for premium power applications, commercial distributed power plants, and for users of secure power supplies. The criteria to be considered is separated into broad categories namely, key features, electrical and system aspects, economics and emissions and costs as well. PEMFC will, in the near future, be used in the automotive industry and also in distributed power supply. Due to its excellent dynamic characteristics, PEMFC can be used as emergency generating set for customer, who have special requirements for their critical equipment in case of power interruptions, harmonics etc. in the public electricity supply. This, however, requires the fulfillment of very detailed specifications concerning the grid connections. The bridging time is defined by the size of the hydrogen storage. The quality problems of normal electricity experienced by commercial and small industrial users have an impact on applications, which provide high quality. Reliable electricity is becoming increasingly popular. Use of this technology in housing areas for electricity and heat generation will be possible in the future, when the costs of production have been greatly reduced. General introduction to the market at a large scale is dependent on reasonable costs, and the chances for cost digression of PEMFC are highest through the use in various market sectors. The paper will end with the conclusion of how to approach the goals and what are the steps between. (author)

  8. Vanadium proton exchange membrane water electrolyser

    Science.gov (United States)

    Noack, Jens; Roznyatovskaya, Nataliya; Pinkwart, Karsten; Tübke, Jens

    2017-05-01

    In order to reverse the reactions of vanadium oxygen fuel cells and to regenerate vanadium redox flow battery electrolytes that have been oxidised by atmospheric oxygen, a vanadium proton exchange membrane water electrolyser was set up and investigated. Using an existing cell with a commercial and iridium-based catalyst coated membrane, it was possible to fully reduce V3.5+ and V3+ solutions to V2+ with the formation of oxygen and with coulomb efficiencies of over 96%. The cell achieved a maximum current density of 75 mA/cm2 during this process and was limited by the proximity of the V(III) reduction to the hydrogen evolution reaction. Due to the specific reaction mechanisms of V(IV) and V(III) ions, V(III) solutions were reduced with an energy efficiency of 61%, making this process nearly twice as energy efficient as the reduction of V(IV) to V(III). Polarisation curves and electrochemical impedance spectroscopy were used to further investigate the losses of half-cell reactions and to find ways of further increasing efficiency and performance levels.

  9. Polybenzimidazole-crosslinked poly(vinylbenzyl chloride) with quaternary 1,4-diazabicyclo (2.2.2) octane groups as high-performance anion exchange membrane for fuel cells

    Science.gov (United States)

    Lu, Wangting; Zhang, Geng; Li, Jin; Hao, Jinkai; Wei, Feng; Li, Wenhui; Zhang, Jiying; Shao, Zhi-Gang; Yi, Baolian

    2015-11-01

    Development of anion exchange membrane (AEM) with high conductivity, good dimensional stability, desirable toughness and long life-time simultaneously is still a challenge for the practical application of AEM fuel cells. Herein, a novel AEM (denoted as PBI-c-PVBC/OH) is fabricated by applying polybenzimidazole (PBI) and 1,4-diazabicyclo (2.2.2) octane (DABCO) as the macromolecular crosslinker and quaternizing reagent for poly(vinylbenzyl chloride) (PVBC), respectively. With the aid of crosslinking by PBI, PBI-c-PVBC/OH exhibits good flexibility and strength both in dry and water-saturated state. Moreover, high hydroxide conductivity (>25 mS cm-1 at room temperature) and low swelling ratio (∼13%) is obtained, especially the swelling ratio nearly does not increase with temperature. The membrane is also advanced for the superior chemical stability in alkaline environment due to the stable polymer backbone and ionic conductive group (only one nitrogen atom in a DABCO molecule is quaternized). Furthermore, a peak power density of 230 mW cm-2 at 50 °C is obtained on the H2/O2 fuel cell using PBI-c-PVBC/OH, and the membrane presents high durability both in the constant current and continuous open circuit voltage testing. Therefore, it is considered that the PBI crosslinking together with DABCO quaternization can be regarded as a promising strategy in the development of AEM for fuel cells.

  10. 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.

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

    Science.gov (United States)

    Haryadi, Sugianto, D.; Ristopan, E.

    2015-12-01

    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-1 and 3300 cm-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 10-2 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.

  12. Designing Alkaline Exchange Membranes from Scratch

    Science.gov (United States)

    2011-10-10

    perfluorinated backbones invite interesting comparisons with the analogous proton exchange membranes. Conference Name: 220th ECS Meeting Conference...based on perfluorinated backbones invite interesting comparisons with the analogous proton exchange membranes. doi: 10.1149/1.3635708 2011, Volume 41...Liberatore,a and Andrew M. Herring,a a Department of Chemical Engineering and bDepartment of Chemistry and Geochemistry, Colorado School of Mines

  13. A comparative study of a bio fuel cell with two different proton exchange membrane for the production of electricity from waste water

    Directory of Open Access Journals (Sweden)

    Amrita Shahi

    2017-03-01

    Full Text Available In the present study, electricity generation with waste water as substrate was investigated in a two compartment biofuel cell with two different combinations of electrodes and membrane. Two proton exchange membranes namely nafion and agar salt bridge and aluminum as electrode were used in the biofuel cell. It was found that biofuel cells operated with nafion produce maximum voltage 0.504 V with a current density of 0.1 A/m2 whereas in case of agar salt bridge maximum voltage of 0.145 V with a current density of 0.05 A/m2 was obtained. The more voltage produced in case of nafion is attributed to its low resistance for hydrogen ion transport.

  14. Preparation and characterization of polymer blend based on sulfonated poly (ether ether ketone) and polyetherimide (SPEEK/PEI) as proton exchange membranes for fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Hashim, Nordiana; Ali, Ab Malik Marwan [Ionic Material and Devices Research Laboratory, Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia); Lepit, Ajis; Rasmidi, Rosfayanti [Faculty of Applied Sciences, Universiti Teknologi MARA Sabah, Beg Berkunci 71, 88997 Kota Kinabalu (Malaysia); Subban, Ri Hanum Yahaya [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia); Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia); Yahya, Muhd Zu Azhan [Faculty of Defence Science & Technology, Universiti Pertahanan Nasional Malaysia, 57000 Kuala Lumpur (Malaysia)

    2015-08-28

    Blends of sulfonated poly (ether ether ketone) (SPEEK) and polyetherimide (PEI) were prepared in five different weight ratios using N-methyl-2-pyrrolidone (NMP) as solvent by the solution cast technique. The degree of sulfonation (DS) of the sulfonated PEEK was determined from deuterated dimethyl sulfoxide (DMSO-d{sub 6}) solution of the purified polymer using {sup 1}H NMR method. The properties studied in the present investigation includes conductivity, water uptake, thermal stability and structure analysis of pure SPEEK as well as SPEEK-PEI polymer blend membranes. The experimental results show that the conductivity of the membranes increased with increase in temperature from 30 to 80°C, except for that of pure SPEEK membrane which increased with temperature from 30 to 60°C while its conductivity decreased with increasing temperature from 60 to 80°C. The conductivity of 70wt.%SPEEK-30wt.%PEI blend membrane at 80% relative humidity (RH) is found to be 1.361 × 10{sup −3} Scm{sup −1} at 30°C and 3.383 × 10{sup −3} Scm{sup −1} at 80°C respectively. It was also found that water uptake and thermal stability of the membranes slightly improved upon blending with PEI. Structure analysis was carried out using Fourier Transform Infrared (FTIR) spectroscopy which revealed considerable interactions between sulfonic acid group of SPEEK and imide groups of PEI. Modification of SPEEK by blending with PEI shows good potential for improving the electrical and physical properties of proton exchange membranes.

  15. Multi-block sulfonated poly(phenylene) copolymer proton exchange membranes

    Science.gov (United States)

    Fujimoto, Cy H [Albuquerque, NM; Hibbs, Michael [Albuquerque, NM; Ambrosini, Andrea [Albuquerque, NM

    2012-02-07

    Improved multi-block sulfonated poly(phenylene) copolymer compositions, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cells, in electrode casting solutions and electrodes. The multi-block architecture has defined, controllable hydrophobic and hydrophilic segments. These improved membranes have better ion transport (proton conductivity) and water swelling properties.

  16. Fuel-Cell Structure Prevents Membrane Drying

    Science.gov (United States)

    Mcelroy, J.

    1986-01-01

    Embossed plates direct flows of reactants and coolant. Membrane-type fuel-cell battery has improved reactant flow and heat removal. Compact, lightweight battery produces high current and power without drying of membranes.

  17. Development of a computational model applied to a unitary 144 cm{sup 2} proton exchange membrane fuel cell; Desenvolvimento de um modelo numerico computacional aplicado a uma celula a combustivel unitaria de 144 CM{sup 2} tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Robalinho, Eric

    2009-07-01

    This work presents the development of a numerical computer model and methodology to study and design polymeric exchange membrane fuel cell - PEM. For the validation of experimental results, a sequence of routines, appropriate to fit the data obtained in the laboratory, was described. At the computational implementation it was created a new strategy of coupling two 3-dimensional models to satisfy the requirements of the comprehensive model of the fuel cell, including its various geometries and materials, as well as the various physical and chemical processes simulated. To effective assessment of the real cell analogy with numerical model, numerical studies were carried out. Comparisons with values obtained in the literature, characterization of variables through laboratory experiments and estimates from models already tested in the literature were also performed. Regarding the experimental part, a prototype of a fuel cell unit of 144 cm of geometric area was designed, produced and operated at laboratory with the purpose of validating the numerical computer model proposed, with positive results. The results of simulations for the 2D and 3D geometries proposed are presented in the form of polarization curves, highlighting the catalytic layer model based on the geometry of agglomerates. Parametric and sensitivity studies are presented to illustrate the change in performance of the fuel cell studied. The final model is robust and useful as a tool for design and optimization of PEM type fuel cells in a wide range of operating conditions. (author)

  18. Development of a computational model applied to a unitary 144 CM{sup 2} proton exchange membrane fuel cell; Desenvolvimento de um modelo numerico computacional aplicado a uma celula a combustivel unitaria de 144 CM{sup 2} tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Robalinho, Eric

    2009-07-01

    This work presents the development of a numerical computer model and methodology to study and design polymeric exchange membrane fuel cell - PEM. For the validation of experimental results, a sequence of routines, appropriate to fit the data obtained in the laboratory, was described. At the computational implementation it was created a new strategy of coupling two 3-dimensional models to satisfy the requirements of the comprehensive model of the fuel cell, including its various geometries and materials, as well as the various physical and chemical processes simulated. To effective assessment of the real cell analogy with numerical model, numerical studies were carried out. Comparisons with values obtained in the literature, characterization of variables through laboratory experiments and estimates from models already tested in the literature were also performed. Regarding the experimental part, a prototype of a fuel cell unit of 144 cm{sup 2} of geometric area was designed, produced and operated at laboratory with the purpose of validating the numerical computer model proposed, with positive results. The results of simulations for the 2D and 3D geometries proposed are presented in the form of polarization curves, highlighting the catalytic layer model based on the geometry of agglomerates. Parametric and sensitivity studies are presented to illustrate the change in performance of the fuel cell studied. The final model is robust and useful as a tool for design and optimization of PEM type fuel cells in a wide range of operating conditions. (author)

  19. Novel quaternary ammonium microblock poly (p-phenylene-co-aryl ether ketone)s as anion exchange membranes for alkaline fuel cells

    Science.gov (United States)

    Dong, Xue; Xue, Boxin; Qian, Huidong; Zheng, Jifu; Li, Shenghai; Zhang, Suobo

    2017-02-01

    Using cation compounds as raw materials, three quaternized microblock poly(p-phenylene-co-aryl ether ketone)s (s-, m-, and l-QPP-co-PAEK) were synthesized using a nickel (0)-catalyzed coupling reaction. Hydrophilic and hydrophobic moieties were affixed using cationic quaternary ammonium (QA) groups attached to poly(p-phenylene) by a three-carbon interstitial spacer and nonionic dichloride monomers of various lengths, respectively. The morphology, water uptake, swelling ratio, mechanical properties, thermal stability, hydroxide conductivity and alkaline stability of these new membranes were investigated. Experimental results indicated that the membrane with the longest hydrophobic microblock exhibited high hydroxide conductivity (37.6 mS cm-1 at 80 °C) resulting from the aggregation of ionic clusters observed using TEM. The copolymers with longer hydrophobic nonionic segments exhibited improved alkaline stability, suggesting that the hydrophobic chain shields the QA groups and that the polymer chains pack in a manner that restricts rotation. Controlling the distribution of QA groups in poly(p-phenylene) moieties and tuning the block length of nonionic segments are demonstrated to be effective methods for improving the hydroxide conductivity and alkaline stability of anion exchange membranes.

  20. 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.

  1. The Role of Ion Exchange Membranes in Membrane Capacitive Deionisation.

    Science.gov (United States)

    Hassanvand, Armineh; Wei, Kajia; Talebi, Sahar; Chen, George Q; Kentish, Sandra E

    2017-09-14

    Ion-exchange membranes (IEMs) are unique in combining the electrochemical properties of ion exchange resins and the permeability of a membrane. They are being used widely to treat industrial effluents, and in seawater and brackish water desalination. Membrane Capacitive Deionisation (MCDI) is an emerging, energy efficient technology for brackish water desalination in which these ion-exchange membranes act as selective gates allowing the transport of counter-ions toward carbon electrodes. This article provides a summary of recent developments in the preparation, characterization, and performance of ion exchange membranes in the MCDI field. In some parts of this review, the most relevant literature in the area of electrodialysis (ED) is also discussed to better elucidate the role of the ion exchange membranes. We conclude that more work is required to better define the desalination performance of the proposed novel materials and cell designs for MCDI in treating a wide range of feed waters. The extent of fouling, the development of cleaning strategies, and further techno-economic studies, will add value to this emerging technique.

  2. 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.

  3. Fuel cell and membrane therefore

    Science.gov (United States)

    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.

  4. V-doped TiO2 supported Pt as a promising oxygen reduction reaction catalyst: Synthesis, characterization and in-situ evaluation in proton exchange membrane fuel cell

    Science.gov (United States)

    Bharti, Abha; Cheruvally, Gouri

    2017-09-01

    This study deals with the synthesis and characterization of V-doped, TiO2 supported Pt catalyst (Pt/V-TiO2) for oxygen reduction reaction (ORR) and its in-situ performance investigation in proton exchange membrane (PEM) fuel cell. Pt/V-TiO2 nanocomposite catalyst is prepared via a facile sol-gel and microwave assisted, modified chemical reduction route and its performance is compared with the undoped TiO2 supported catalyst, Pt/TiO2 prepared in an identical way. The prepared Pt/V-TiO2 and Pt/TiO2 catalysts are employed as cathode catalyst in PEM fuel cell and compared with standard Pt/C catalyst. Their comparative studies are conducted with physical and electrochemical techniques. In-situ electrochemical characterization studies show improved ORR catalytic activity of Pt/V-TiO2 compared to Pt/TiO2. Furthermore, both Pt/TiO2 and Pt/V-TiO2 are more stable than Pt/C when subjected to 6000 voltammetric cycles in the range of 0.2-1.2 V vs. standard hydrogen electrode in operating fuel cell conditions, losing only nanocomposite material as a potential cathode catalyst for PEM fuel cell with immense scope for further investigation.

  5. Partially fluorinated electrospun proton exchange membranes

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention relates to a novel porous membrane layer, to a novel method for producing a membrane, and the membranes produced by the novel method. The present invention further relates to a fuel cell comprising the porous layer, as well as any use of the porous layer in a fuel cell...... or in a filter. The porous membrane layer comprises a plurality of randomly oriented fibers manufactured by electrospinning, wherein the fibers comprise a graft copolymer, wherein the graft copolymer comprises a backbone and at least one side chain, wherein the backbone comprises a partially fluorinated...... copolymer, and wherein at least one side chain of the graft copolymer comprises a polymerization product of a polymerizable proton donor group or a precursor thereof....

  6. Anion Exchange Membranes: Current Status and Moving Forward

    Energy Technology Data Exchange (ETDEWEB)

    Hickner, MA; Herring, AM; Coughlin, EB

    2013-10-29

    This short review is meant to provide the reader with highlights in anion exchange membrane research, describe current needs in the field, and point out promising directions for future work. Anion exchange membranes (AEMs) provide one possible route to low platinum or platinum-free fuel cells with the potential for facile oxidation of complex fuels beyond hydrogen and methanol. AEMs and related stable cationic polymers also have applications in energy storage and other electrochemical technologies such as water electrolyzers and redox flow batteries. While anion exchange membranes have been known for a long time in water treatment applications, materials for electrochemical technology with robust mechanical properties in thin film format have only recently become more widely available. High hydroxide and bicarbonate anion conductivity have been demonstrated in a range of AEM formats, but intrinsic stability of the polymers and demonstration of long device lifetime remain major roadblocks. Novel approaches to stable materials have focused on new types of cations that employ delocalization and steric shielding of the positive center to mitigate nucleophilic attack by hydroxide. A number of promising polymer backbones and membrane architectures have been identified, but limited device testing and a lack of understanding of the degradation mechanisms in operating devices is slowing progress on engineered systems with alkaline fuel cell technology. Our objective is to spur more research in this area to develop fuel cell systems that approach the costs of inexpensive batteries for large-scale applications. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1727-1735, 2013

  7. Proton exchange membranes based on PVDF/SEBS blends

    Science.gov (United States)

    Mokrini, A.; Huneault, M. A.

    Proton-conductive polymer membranes are used as an electrolyte in the so-called proton exchange membrane fuel cells. Current commercially available membranes are perfluorosulfonic acid polymers, a class of high-cost ionomers. This paper examines the potential of polymer blends, namely those of styrene-(ethylene-butylene)-styrene block copolymer (SEBS) and polyvinylidene fluoride (PVDF), in the proton exchange membrane application. SEBS/PVDF blends were prepared by twin-screw extrusion and the membranes were formed by calendering. SEBS is a phase-segregated material where the polystyrene blocks can be selectively functionalized offering high ionic conductivity, while PVDF insures good dimensional stability and chemical resistance to the films. Proton conductivity of the films was obtained by solid-state grafting of sulfonic acid moieties. The obtained membranes were characterized in terms of conductivity, ionic exchange capacity and water uptake. In addition, the membranes were characterized in terms of morphology, microstructure and thermo-mechanical properties to establish the blends morphology-property relationships. Modification of interfacial properties between SEBS and PVDF was found to be a key to optimize the blends performance. Addition of a methyl methacrylate-butyl acrylate-methyl methacrylate block copolymer (MMA-BA-MMA) was found to compatibilize the blend by reducing the segregation scale and improving the blend homogeneity. Mechanical resistance of the membranes was also improved through the addition of this compatibilizer. As little as 2 wt.% compatibilizer was sufficient for complete interfacial coverage and lead to improved mechanical properties. Compatibilized blend membranes also showed higher conductivities, 1.9 × 10 -2 to 5.5 × 10 -3 S cm -1, and improved water management.

  8. Low temperature direct propane polymer electrolyte membranes fuel cell (DPFC)

    Energy Technology Data Exchange (ETDEWEB)

    Savadogo, O.; Varela, F. J. R. [Ecole Polytechnique, Laboratoire d' electrochimie et de materiaux energetiques, Montreal, PQ (Canada)

    2001-04-01

    A low-temperature direct propane polymer electrolyte membrane fuel cell (DPFC) is demonstrated. The propane is fed into the fuel cell directly, eliminating the need for reforming. The key elements of the DPFC system are an appropriate catalyst for the anodes, an appropriate membrane and a propane humidifier. Overall, the system consists of a propane container, an oxygen container, a propane humidifier, and oxygen humidifier, a proton exchange membrane fuel cell (PEMFC), and a fuel cell station monitored by a computer. The membranes are Nafion 117, doped with heteropolyacids (HPAs) or polybenzimidazole (PBI). The fuel cell was built of graphite blocks in which flow fields were engraved, one for humidified propane, the other for oxygen. The anode was based on platinum, platinum-ruthenium, or platinum-chromium oxide electrocatalysts; the cathode was based on a platinum electrocatalyst. Results showed that polymer electrolyte membranes can be directly fed by propane gas to make direct propane fuel cell (DPFC). This has many advantages compared to methanol, such as lower cost, greater operating temperature range, easy handling, simpler infrastructure requirements, and higher energy than those of methanol. However, like methanol, DPFC also has the disadvantage that its reaction product is carbon dioxide. 22 refs., 2 tabs., 5 figs.

  9. Fuel cell membranes and crossover prevention

    Science.gov (United States)

    Masel, Richard I [Champaign, IL; York, Cynthia A [Newington, CT; Waszczuk, Piotr [White Bear Lake, MN; Wieckowski, Andrzej [Champaign, IL

    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.

  10. 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 The research on ion-exchange membranes has grown considerably in recent years with the growing interest in fuel cell technology for the automotive and portable applications. The requirements for a fuel cell membrane are the following: high chemical...

  11. 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.

  12. Novel proton exchange membranes based on cardo poly(arylene ether sulfone/nitrile)s with perfluoroalkyl sulfonic acid moieties for passive direct methanol fuel cells

    Science.gov (United States)

    Zheng, Jifu; He, Qingyi; Gao, Nian; Yuan, Ting; Zhang, Suobo; Yang, Hui

    2014-09-01

    A new series of cardo poly(arylene ether sulfone/nitrile)s FSPES-x with perfluoroalkyl sulfonic acid groups have been successfully prepared by the perfluorosulfonic acid lactone ring-opening reaction without using any metal or base catalysts. These materials have been characterized by IR, NMR and TGA. The results indicate that this simple and metal-free method of preparation is highly efficient for controlling both the degree of perfluorosulfonation and the position of the sulfonate group and no side reactions such as crosslinking is observed. The FSPES-x membranes (IEC = 1.17-1.64 m equiv g-1) show the desired characteristics such as good film-forming ability, excellent thermal and mechanical properties, low methanol permeability, high conductivity (up to 0.083 S cm-1 at room temperature), as well as appropriate cell performance compared to Nafion®117. With these properties, such fluorinated sulfonic acid side-chain-type polymers are promising PEM materials for application in fuel cells.

  13. Polypropylene (PP) based proton exchange membrane for use in fuel cell; Obtencao de membrana trocadora de protons para uso em celula a combustivel, a base de polipropileno (PP)

    Energy Technology Data Exchange (ETDEWEB)

    Zen, Heloisa Augusto

    2008-07-01

    The radiation-induced graft of styrene onto polypropylene (PP) films was carried out by simultaneous irradiation method in a cobalt-60 source. The PP films were immersed in a solution of styrene with toluene (1:1 and 4:1, v/v) under inert atmosphere and at room temperature and then submitted at 20, 40, 80 and 100 kGy. After graft reaction the films were kept at room temperature under inert atmosphere for periods of 7, 14, 21 and 28 days in order to evaluate the degree of grafting. At the end of each period the films were sulfonated to provide the hydrophilic property to PP. The degree of grafting (DOG) was gravimetric determined and the chemical changes in the grafted and sulfonated films were characterized by Infrared Spectroscopy, Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry and the Ion Exchange Capacity (IEC) was calculated. The greatest DOG was obtained after 21 days of post-irradiation. By TGA the grafted films exhibited a decrease in the thermal stability, while the sulfonated exhibited an increase. By DSC was possible to verify that matrix polymeric did not suffer any drastic change in the melting temperature after grafting and sulfonation reactions. The IEC calculated shows that the new membrane developed has ionic conductivity property. (author)

  14. Effect of catalyst distribution in the active layers of proton exchange membrane fuel cells; Effet de la distribution du catalyseur dans les couches actives de piles a combustible de type PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Bultel, Y.; Durand, R.; Ozil, P. [Ecole Nationale Superieure d' Electrochimie et d' Electrometallurgie, Lab. d' Electrochimie et de Physico-chimie des Materiaux et des Interfaces, UMR 5631, 38 - Grenoble (France); Antoine, O. [Geneva Univ., Dept. de Chimie Minerale, Analytique et Appliquee, Sciences 2 (Switzerland)

    2000-07-01

    The aim of this work is to study the influence of the distribution of the platinum catalyst in the active layers on the performances of proton exchange membrane fuel cells (PEMFC) electrodes. In the one hand, the results predicted by the classical models and those in which the active layers is modified have been compared; these results have allowed to demonstrate theoretically the effect of the discrete distribution of the platinum catalyst in the form of nano-particles. On the other hand, the influence of a distribution gradient of the platinum catalyst for porous and non-porous active layers of PEMFC cathode has been experimentally demonstrated and predicted by numerical simulations. (O.M.)

  15. Environmental-Friendly Solid Synthesis of Fe-N-C Electrocatalyst with Fe Exclusively in Atomically Dispersed Fe-N4 Moieties for High-Power Proton Exchange Membrane Fuel Cells.

    Science.gov (United States)

    Liu, Qingtao; Liu, Xiaofang; Zheng, Lirong; Shui, Jianglan

    2017-12-05

    Environmental-friendly synthesis of highly active Fe-N-C electrocatalyst for proton exchange membrane fuel cells (PEMFCs) is desirable but remains challenging. Herein, we report a green, simple and scalable method to fabricate Fe(II)-doped ZIF-8, which can be further pyrolyzed into Fe-N-C with 3 wt.% of Fe exclusively in Fe-N4 active moieties. Significantly, this Fe-N-C derived acidic PEMFC exhibits an unprecedented current density of 1.65 A cm-2 at 0.6 V and the highest power density of 1.14 W cm-2 compared with previously reported NPMCs. The excellent PEMFC performance can be attributed to the densely and atomically dispersed Fe-N4 active moieties on the small and uniform catalyst nanoparticles. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Advanced nanocomposite membranes for fuel cell applications: a comprehensive review

    Directory of Open Access Journals (Sweden)

    Kolsoum Pourzare

    2016-12-01

    Full Text Available Combination of inorganic fillers into organic polymer membranes (organic–inorganic hybrid membranes has drawn a significant deal of attention over the last few decades. This is because of the incorporated influence of the organic and inorganic phases towards proton conductivity and membrane stability, in addition to cost decline, improved water retention property, and also suppressing fuel crossover by increasing the transport pathway tortuousness. The preparation methods of the composite membranes and the intrinsic characteristics of the used particles as filler, such as size, type, surface acidity, shape, and their interactions with the polymer matrix can significantly affect the properties of the resultant matrix. The membranes currently used in proton exchange membrane fuel cells (PEMFCs are perfluorinated polymers containing sulfonic acid, such as Nafion®. Although these membranes possess superior properties, such as high proton conductivity and acceptable chemical, mechanical, and thermal stability, they suffer from several disadvantages such as water management, CO poisoning, and fuel crossover. Organic-inorganic nanocomposite PEMs offer excellent potentials for overcoming these shortcomings in order to achieve improved FC performance. Various inorganic fillers for the fabrication of composite membranes have been comprehensively reviewed in the present article. Moreover, the properties of polymer composites containing different nanoparticles have been thoroughly discussed.

  17. Review on Modification of Sulfonated Poly (-ether-ether-ketone Membranes Used as Proton Exchange Membranes

    Directory of Open Access Journals (Sweden)

    Xiaomin GAO

    2015-11-01

    Full Text Available The proton exchange membrane fuel cell (PEMFC is a type of modern power, but the traditional proton exchange membranes (PEM of PEMFC are limited by high methanol permeability and water uptake. Poly-ether-ether-ketone (PEEK is a widely used thermoplastic with good cost-effective property. Sulfonated poly (-ether-ether-ketone (SPEEK has high electric conductivity and low methanol permeability, as well as comprehensive property, which is expected to be used as PEMs. However, the proton exchange ability, methanol resistance, mechanical property and thermal stability of SPEEK are closely related to the degree of sulfonation (DS of SPEEK membranes. Additionally, the proton conductivity, methanol permeability, and stability of SPEEK membranes applied in various conditions need to be further improved. In this paper, the research into modification of SPEEK membranes made by SPEEK and other polymers, inorganic materials are introduced. The properties and modification situation of the SPEEK and the composite membranes, as well as the advantages and disadvantages of membranes prepared by different materials are summarized. From the results we know that, the methanol permeability of SPEEK/PES-C membranes is within the order of magnitude, 10-7cm2/s. The proton conductivity of the SPPESK/SPEEK blend membrane reaches 0.212 S cm-1 at 80 °C. The cross-linked SPEEK membranes have raised thermal and dimensional stability. The non-solvent caused aggregation of the SPEEK ionomers. The proton conductivity of SPEEK/50%BMIMPF6/4.6PA membrane maintains stable as 2.0 x 10-2S cm-1 after 600 h at 160 °C. Incorporation of aligned CNT into SPEEK increases the proton conductivity and reduces the methanol permeability of the composite membranes. The PANI improves the hydrothermal stability. More proton transfer sites lead to a more compact structure in the composite membranes. According to the results, the proton exchange capacity, water uptake, and conductivity of

  18. Modeling and off-design performance of a 1 kWe HT-PEMFC (high temperature-proton exchange membrane fuel cell)-based residential micro-CHP (combined-heat-and-power) system for Danish single-family households

    DEFF Research Database (Denmark)

    Arsalis, Alexandros; Nielsen, Mads Pagh; Kær, Søren Knudsen

    2011-01-01

    A novel proposal for the modeling and operation of a micro-CHP (combined-heat-and-power) residential system based on HT-PEMFC (High Temperature-Proton Exchange Membrane Fuel Cell) technology is described and analyzed to investigate its commercialization prospects. An HT-PEMFC operates at elevated...

  19. Análisis y optimización de una celda de combustible de membrana de intercambio protónico; Analysis and optimization of a proton exchange membrane fuel cell using modeling techniques

    Directory of Open Access Journals (Sweden)

    Raciel de la Torre Valdés

    2015-04-01

    Full Text Available En el presente trabajo se realizó la modelación tridimensional y estacionaria de una celda de combustible de intercambio protónico empleando técnicas de modelación de dinámica de fluidos computacional, específicamente el software ANSYS FLUENT 14.5. El modelo fue comparado con datos experimentales y con resultados de otro modelo. Se analizaron los parámetros de operación del dispositivo presión y temperatura, sentido de los flujos, porosidad de los electrodos, humidificación de los gases y concentración de oxígeno. Se optimizó el diseño de la celda teniendo en cuenta las dimensiones de los canales y el espesor de la membrana. Se analizó el rendimiento de la celda funcionando con la membrana SPEEK (por sus siglas en inglés. Para realizar este estudio fue necesario modificar la expresión que describe la conductividad iónica. Se encontró que el rendimiento del dispositivo tiene gran sensibilidad a la variación de los parámetros termodinámicos y la composición de los gases. This paper proposes a three-dimensional, non-isothermal and steady-state model of Proton Exchange Membrane Fuel Cell using Computational Fluid Dynamic techniques, specifically ANSYS FLUENT 14.5. It's considered multicomponent diffusion and two-phasic flow. The model was compared with experimental published data and with another model. The operation parameters: reactants pressure and temperature, gases flow direction, gas diffusion layer and catalyst layer porosity, reactants humidification and oxygen concentration are analyzed. The model allows the fuel cell design optimization taking in consideration the channels dimensions, the channels length and the membrane thickness. Furthermore, fuel cell performance is analyzed working with SPEEK membrane, an alternative electrolyte to Nafion. In order to carry on membrane material study, it’s necessary to modify the expression that describes the electrolyte ionic conductivity. It’s found that the device

  20. 21 CFR 173.21 - Perfluorinated ion exchange membranes.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Perfluorinated ion exchange membranes. 173.21... ion exchange membranes. Substances identified in paragraph (a) of this section may be safely used as ion exchange membranes intended for use in the treatment of bulk quantities of liquid food under the...

  1. Interferometric tomography of fuel cells for monitoring membrane water content.

    Science.gov (United States)

    Waller, Laura; Kim, Jungik; Shao-Horn, Yang; Barbastathis, George

    2009-08-17

    We have developed a system that uses two 1D interferometric phase projections for reconstruction of 2D water content changes over time in situ in a proton exchange membrane (PEM) fuel cell system. By modifying the filtered backprojection tomographic algorithm, we are able to incorporate a priori information about the object distribution into a fast reconstruction algorithm which is suitable for real-time monitoring.

  2. Parameter Estimates for a Polymer Electrolyte Membrane Fuel Cell Cathode

    OpenAIRE

    Guo, Qingzhi; Sethuraman, Vijay A.; White, Ralph E.

    2013-01-01

    Five parameters of a model of a polymer electrolyte membrane fuel cell cathode (the porosity of the gas diffusion layer, the porosity of the catalyst layer, the exchange current density of the oxygen reduction reaction, the effective ionic conductivity of the electrolyte, and the ratio of the effective diffusion coefficient of oxygen in a flooded spherical agglomerate particle to the squared particle radius) were determined by the least square fitting of experimental polarization curves. The ...

  3. Synthesis and Characterization of Stable Anion Exchange Membranes: The Addition of Electron-withdrawing Group

    Directory of Open Access Journals (Sweden)

    Gülşen ALBAYRAK ARI

    2016-10-01

    Full Text Available Anion exchange membranes (AEM based on poly(2,6-dimethyl-1,4-phenylene oxide (PPO were used as polymer electrolyte membrane for fuel cell applications. The membranes were prepared via bromination, quaternization and nitration reactions and their fuel cell-related properties (water uptake, ion exchange capacity, ionic conductivity were determined. Also, the structures and thermal properties were studied with Fourier transform infrared spectroscopy (FTIR, Size exclusion chromatography (SEC and Differential scanning calorimetry (DSC. Nitration of quaternized PPO (Q-PPO leaded to a decrease in water uptake and ion exchange capacity of the AEM. However, Q-PPO membrane treated with nitration reaction (NO2-Q-PPO exhibited a significant alkaline stability compared to quaternized PPO (Q-PPO.   The results indicated that the addition of electron-withdrawing group, such as nitro, into the structure in order to improve in alkaline stability is a promising new route for preparation alkaline stable AEM membranes.

  4. Pd and Pt-Ru anode electrocatalysts supported on multi-walled carbon nanotubes and their use in passive and active direct alcohol fuel cells with an anion-exchange membrane (alcohol = methanol, ethanol, glycerol)

    Science.gov (United States)

    Bambagioni, Valentina; Bianchini, Claudio; Marchionni, Andrea; Filippi, Jonathan; Vizza, Francesco; Teddy, Jacques; Serp, Philippe; Zhiani, Mohammad

    Palladium and platinum-ruthenium nanoparticles supported on multi-walled carbon nanotubes (MWCNT) are prepared by the impregnation-reduction procedure. The materials obtained, Pd/ MWCNT and Pt-Ru/ MWCNT, are characterized by TEM, ICP-AES and XRPD. Electrodes coated with Pd/ MWCNT are scrutinized for the oxidation of methanol, ethanol or glycerol in 2 M KOH solution in half cells. The catalyst is very active for the oxidation of all alcohols, with glycerol providing the best performance in terms of specific current density and ethanol showing the lowest onset potential. Membrane-electrode assemblies have been fabricated using Pd/ MWCNT anodes, commercial cathodes and anion-exchange membrane and evaluated in both single passive and active direct alcohol fuel cells fed with aqueous solutions of 10 wt.% methanol, 10 wt.% ethanol or 5 wt.% glycerol. Pd/ MWCNT exhibits unrivalled activity as anode electrocatalyst for alcohol oxidation. The analysis of the anode exhausts shows that ethanol is selectively oxidized to acetic acid, detected as acetate ion in the alkaline media of the reaction, while methanol yields carbonate and formate. A much wider product distribution, including glycolate, glycerate, tartronate, oxalate, formate and carbonate, is obtained from the oxidation of glycerol. The results obtained with Pt-Ru/ MWCNT anodes in acid media are largely inferior to those provided by Pd/ MWCNT electrodes in alkaline media.

  5. Membrane degradation mechanisms in polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Mittal, Vishal Onkarmal

    Membrane degradation and failure is one of the most important factors limiting the lifetime of polymer electrolyte membrane fuel cells (PEMFCs). Increasing the membrane life by developing degradation mitigation strategies in the cell or developing a new membrane with improved life requires a detailed understanding of the membrane degradation mechanism during operation in a PEMFC. An in-situ and nondestructive technique, which relies on the measurement of the membrane degradation rate in a fuel cell, was used to study the chemical/electrochemical mode of membrane degradation. NafionRTM membrane was used for the degradation study and fluoride emission rate (FER) as measured from the fuel cell effluent water analysis was used as a quantitative indicator of the membrane degradation rate. The degradation mechanism was studied by a detailed investigation of the effect of reactants, catalyst properties (location, potential, catalyst type, interaction with O2 and H2O), cell current, membrane thickness, NafionRTM counterion, and direction of water movement on the membrane degradation rate. Based on the experimental findings it is shown that commonly known membrane degradation mechanisms involving formation of active oxygen species from H 2O2 decomposition or the direct formation of active oxygen species in the oxygen reduction reaction are not the dominating membrane degradation mechanisms in PEMFCs. It is proposed that molecular H2 and O 2 react on the surface of Pt catalyst to form the membrane degrading species. Depending upon the catalyst location the source of H2 or O2 or both is from the reactant crossover through the membrane. The reaction mechanism is chemical in nature and depends upon the catalyst surface properties and the relative concentrations of H2 and O 2 at the catalyst. The membrane degradation rate also depends on the residence time of the species in the membrane and the reaction volume i.e. the membrane thickness. Thus, the membrane degradation may not

  6. Environmental analysis of the proton exchange membrane fuel cell on the subject of life cycle assessment; Analise ambiental da celula a combustivel de membrana trocadora de protons sob o enfoque da avaliacao do ciclo de vida

    Energy Technology Data Exchange (ETDEWEB)

    Fukurozaki, Sandra Harumi

    2006-07-01

    The energy is the fuel of growth and an essential requirement for the socioeconomic development. However, the current production model is based on fossil fuels, considered as threat to man and nature. As for, the relating to the human activities and their effects on the environment, they are handled by the implementation of a more rigid model of environmental control and the mobilization of the society in favor of technologies with less energy impact. In view of this scenario, the Proton Exchange Membrane Fuel Cell - PEMFC has been recognized as a key for the vital need of a clean and efficient energy. Considering the conventional power generation system, their advantages during usage configure its application as an ideal option for several utilities, especially in the mobile sector. Even though, the focus on several environmental evaluations in energy systems is referred back to the initial stage of it use, the employment relating to production of the system and to final destination should be considered, since these also present impacts. In the case of PEMFC, their previous and subsequent phases of use are issues related to the platinum catalysts, which indicates an environmental importance that cannot be overlooked. In this sense, the Life Cycle Assessment has been used to understand and to question the risks and opportunities that are associated to certain product, starting from a systemic concept of their relationships with the environment. It is precisely in this context that the present research intends to present its major contribution, starting from an exploratory study towards the its objectives to provide an environmental analysis of such technology linked to post stage of powder-use of the membrane electrode assembly - MEA, concerning the platinum catalysts, on the subject of Life Cycle Assessment - LCA. To attain such aim, the relationships between energy, environment and development are presented and discussed, as well as, the Fuel Cell technology and

  7. Modeling and optimization of a heat-pump-assisted high temperature proton exchange membrane fuel cell micro-combined-heat-and-power system for residential applications

    DEFF Research Database (Denmark)

    Arsalis, Alexandros; Kær, Søren Knudsen; Nielsen, Mads Pagh

    2015-01-01

    In this study a micro-combined-heat-and-power (micro-CHP) system is coupled to a vapor-compression heat pump to fulfill the residential needs for heating (space heating and water heating) and electricity in detached single-family households in Denmark. Such a combination is assumed to be attractive...... for application, since both fuel cell technology and electric heat pumps are found to be two of the most efficient technologies for generation/conversion of useful energy. The micro-CHP system is fueled with natural gas and includes a fuel cell stack, a fuel processor and other auxiliary components. The micro....... The variational loads are considered from full to quarter load, and the micro-CHP system is optimized in terms of operating thermophysical parameters for every different load. The results clearly indicate the capability of the proposed system to perform efficiently throughout all necessary load changes to fulfill...

  8. 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.

  9. Mass-charge-heat coupled transfers in a single cell of a proton exchange membrane fuel cell; Transferts couples masse-charge-chaleur dans une cellule de pile a combustible a membrane polymere

    Energy Technology Data Exchange (ETDEWEB)

    Ramousse, J.

    2005-11-15

    Understanding and modelling of coupled mass, charges and heat transfers phenomena are fundamental to analyze the electrical behaviour of the system. The aim of the present model is to describe electrical performances of a PEFMC according to the fluidic and thermal operating conditions. The water content of the membrane and the water distribution in the single cell are estimated according to the coupled simulations of mass transport in the thickness of the single cell and in the feeding channels of the bipolar plates. A microscopic model of a Gas Diffusion Electrode is built up to describe charges transfer phenomena occurring at the electrodes. Completed by a study of heat transfer in the Membrane Electrode Assembly, conditions and preferential sites of water vapor condensation can be highlighted. A set of measurements of the effective thermal conductivity of carbon felts used in fuel cells as porous backing layers have also been performed. Although the value of this parameter is essential for the study of heat transfer, it is still under investigation because of the strong thermal anisotropy of the medium. (author)

  10. Membrane device and process for mass exchange, separation, and filtration

    Science.gov (United States)

    Liu, Wei; Canfield, Nathan L.

    2016-11-15

    A membrane device and processes for fabrication and for using are disclosed. The membrane device may include a number of porous metal membranes that provide a high membrane surface area per unit volume. The membrane device provides various operation modes that enhance throughput and selectivity for mass exchange, mass transfer, separation, and/or filtration applications between feed flow streams and permeate flow streams.

  11. Efeito dos dióxidos de enxofre e de nitrogênio no desempenho de uma célula a combustível de membrana de intercâmbio de prótons Effect of sulfur and nitrogen dioxides on the performance of a proton exchange membrane fuel cell

    Directory of Open Access Journals (Sweden)

    Thiago Lopes

    2008-01-01

    Full Text Available There is presently much interest in the clean and efficient generation of energy by proton exchange membrane fuel cells (PEMFC, using hydrogen as fuel. The generation of hydrogen by the reforming of other fuels, anaerobic fermentation of residual waters and other methods, often produce contaminants that affect the performance of the cell. In this work, the effect of gaseous SO2 and NO2 on the performance of a H2/O2 single PEMFC is studied. The results show that SO2 decreases irreversibly the performance of the cell under operating conditions, while NO2 has a milder effect that allows the recovery of the system.

  12. 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.

  13. 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.

  14. Near-infrared imaging of water in a polymer electrolyte membrane during a fuel cell operation.

    Science.gov (United States)

    Morita, Shigeaki; Jojima, Yuki; Miyata, Yasushi; Kitagawa, Kuniyuki

    2010-11-15

    A novel technique of spectroscopic imaging using a near-infrared (NIR) laser sheet beam was developed for visualization of liquid water in a proton-exchange membrane (PEM) sandwiched between two opaque electrodes set in a polymer electrolyte fuel cell (PEFC). In-plane two-dimensional distribution of water in the thin membrane was clearly visualized during the fuel cell operation. Under the condition of fuel feeding into the PEFC without humidification, water was generated by the fuel cell reaction in the whole electrode area. In contrast, under the condition of fuel feeding with humidification, the PEM got wet in the vicinity of a gas flow field locally.

  15. Research and development of a proton-exchange-membrane (PEM) fuel cell system for transportation applications. Progress report for Quarter 4 of the Phase II report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-20

    This 4th quarter report summarizes activity from July 1, 1995 through October 1, 1995; the report is organized as usual into sections describing background information and work performed under the main WBS categories: The Fuel Processor (WBS 1.0) team activity during this quarter focused on the continued design/development of the full scale fuel processing hardware. The combustor test stand has been completed allowing more detailed testing of the various parts of the combustor subsystem; this subsystem is currently being evaluated using the dual fuel (methanol/hydrogen) option to gain a better understanding of the control issues. The Fuel Cell Stack (WBS 2.0) team activity focused on material analysis and testing to determine the appropriate approach for the first GM stack. Five hundred hours of durability was achieved on a single cell fixture using coated titanium plates (anode and cathode) with no appreciable voltage degradation of the SEL (Stack Engineering Lab) produced MEA. Additionally, the voltage level drop across each of the plates remained low (<5mv) over the full test period; The system integration and control team focused on the initial layout and configuration of the system; and the Reference powertrain and commercialization studies are currently under review.

  16. Performance of electric forklift with low-temperature polymer exchange membrane fuel cell power module and metal hydride hydrogen storage extension tank

    Science.gov (United States)

    Lototskyy, Mykhaylo V.; Tolj, Ivan; Parsons, Adrian; Smith, Fahmida; Sita, Cordellia; Linkov, Vladimir

    2016-06-01

    We present test results of a commercial 3-tonne electric forklift (STILL) equipped with a commercial fuel cell power module (Plug Power) and a MH hydrogen storage tank (HySA Systems and TF Design). The tests included: (i) performance evaluation of "hybrid" hydrogen storage system during refuelling at low (forklift performances during heavy-duty operation when changing the powering in the series: standard battery - fuel cell power module (alone) - power module with integrated MH tank; and (iii) performance tests of the forklift during its operation under working conditions. It was found that (a) the forklift with power module and MH tank can achieve 83% of maximum hydrogen storage capacity during 6 min refuelling (for full capacity 12-15 min); (b) heavy-duty operation of the forklift is characterised by 25% increase in energy consumption, and during system operation mor