WorldWideScience

Sample records for polymer membrane fuel

  1. POLYMER ELECTROLYTE MEMBRANE FUEL CELLS

    DEFF Research Database (Denmark)

    2001-01-01

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

  2. Radiation Grafted Polymer Membranes for Fuel Cell Applications

    International Nuclear Information System (INIS)

    Scherer, G.G.; Wallasch, F.; Ben Youcef, H.; Gubler, L.

    2012-01-01

    Partially fluorinated proton exchange membranes prepared via radiation induced graft copolymerization ('radiation grafting') offer the prospect of cost-effective and tailor made membrane electrolytes for the polymer electrolyte fuel cell (PEFC). The composition and structure of radiation grafted membranes can be adjusted in a broad range to balance the different requirements of proton transport and mechanical robustness. Based on the earlier work on Styrene grafting, the novel monomer combination α-methyl-styrene/methacrylonitrile (AMS/MAN) is introduced for improved stability in the prevailing fuel cell environment. Successful fuel cell experiments proved the concept. (author)

  3. Radiation Grafted Polymer Membranes for Fuel Cell Applications

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, G G; Wallasch, F; Ben Youcef, H; Gubler, L [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen (Switzerland)

    2012-09-15

    Partially fluorinated proton exchange membranes prepared via radiation induced graft copolymerization ('radiation grafting') offer the prospect of cost-effective and tailor made membrane electrolytes for the polymer electrolyte fuel cell (PEFC). The composition and structure of radiation grafted membranes can be adjusted in a broad range to balance the different requirements of proton transport and mechanical robustness. Based on the earlier work on Styrene grafting, the novel monomer combination {alpha}-methyl-styrene/methacrylonitrile (AMS/MAN) is introduced for improved stability in the prevailing fuel cell environment. Successful fuel cell experiments proved the concept. (author)

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

    Science.gov (United States)

    Xiao, Lixiang

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

  5. 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.

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

    Science.gov (United States)

    Narayan, Sri; Reddy, Prakash

    2012-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  9. 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 ...

  10. Toughness of membranes applied in polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-08-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

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

    DEFF Research Database (Denmark)

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

    2003-01-01

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

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

    Science.gov (United States)

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

    2013-12-05

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

  14. A Comparison of Water Diffusion in Polymer Based Fuel Cell and Reverse Osmosis Membrane Materials

    Science.gov (United States)

    Soles, Christopher; Frieberg, Bradley; Tarver, Jacob; Tyagi, Madhusudan; Jeong, Cheol; Chan, Edwin; Stafford, Christopher

    Hydrated polymer membranes are critical in both fuel cells and water filtration and desalination. In both of these applications the membrane function (selectively transporting or separating ions) is coupled with the transport of water through the membrane. There is a significant need to understand the nature by which the water and ions distribute and move through these membranes. This presentation compares the transport mechanisms in in an ion containing block copolymer alkaline fuel cell membrane with that of a polyamide membrane that is used as the active layer in a reverse osmosis water desalination membrane. Small angle neutron scattering measurements are used to locally probe how water swells the different materials and quantitatively describe the distribution of water within the membrane microstructures. Quasielastic neutron scattering measurements are then used to separate the polymer dynamics of the host membranes from the dynamics of the water inside the membranes. This reveals that water moves at least an order of magnitude slower through the ion containing fuel cell membrane materials, consistent with a solution-diffusion model, while the water in the polyamide membranes moves faster, consistent with a pore-flow diffusion mechanism. These insights will be discussed in terms of a coupling of the water and polymer dynamics and design cues for high performance membrane materials.

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

    Science.gov (United States)

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

    2011-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-08-05

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

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

    Directory of Open Access Journals (Sweden)

    Xiaoteng Liu

    2013-12-01

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

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

    OpenAIRE

    Xing, Wei; Wu, Zucheng; Tao, Shanwen

    2016-01-01

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

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

    OpenAIRE

    Gerteisen, D.

    2010-01-01

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

  20. Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Viktor Johánek

    2016-01-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

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

    KAUST Repository

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

    2010-01-01

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

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

    DEFF Research Database (Denmark)

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

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

    Directory of Open Access Journals (Sweden)

    Hazlina Junoh

    2015-01-01

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

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

    DEFF Research Database (Denmark)

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

    2002-01-01

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

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

    Science.gov (United States)

    Zhang, Tao

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    DEFF Research Database (Denmark)

    Li, Qingfeng

    2003-01-01

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

  9. Quaternized poly(vinyl alcohol)/alumina composite polymer membranes for alkaline direct methanol fuel cells

    Science.gov (United States)

    Yang, Chun-Chen; Chiu, Shwu-Jer; Chien, Wen-Chen; Chiu, Sheng-Shin

    The quaternized poly(vinyl alcohol)/alumina (designated as QPVA/Al 2O 3) nanocomposite polymer membrane was prepared by a solution casting method. The characteristic properties of the QPVA/Al 2O 3 nanocomposite polymer membranes were investigated using thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), micro-Raman spectroscopy, and AC impedance method. Alkaline direct methanol fuel cell (ADMFC) comprised of the QPVA/Al 2O 3 nanocomposite polymer membrane were assembled and examined. Experimental results indicate that the DMFC employing a cheap non-perfluorinated (QPVA/Al 2O 3) nanocomposite polymer membrane shows excellent electrochemical performances. The peak power densities of the DMFC with 4 M KOH + 1 M CH 3OH, 2 M CH 3OH, and 4 M CH 3OH solutions are 28.33, 32.40, and 36.15 mW cm -2, respectively, at room temperature and in ambient air. The QPVA/Al 2O 3 nanocomposite polymer membranes constitute a viable candidate for applications on alkaline DMFC.

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

    Science.gov (United States)

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

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

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

    International Nuclear Information System (INIS)

    Putri, Zufira; Arcana, I Made

    2014-01-01

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

  12. 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.

  13. Durability of PEM Fuel Cell Membranes

    Science.gov (United States)

    Huang, Xinyu; Reifsnider, Ken

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

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

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Li, Qingfeng

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

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

    Science.gov (United States)

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

    2015-12-08

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-24

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

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

    Directory of Open Access Journals (Sweden)

    Celik Muhammet

    2016-01-01

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

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

    International Nuclear Information System (INIS)

    Mulijani, S.

    2017-01-01

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

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

    DEFF Research Database (Denmark)

    Li, Qingfeng; Jensen, Jens Oluf

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Moeller-Holst, S.

    1996-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Moeller-Holst, S

    1997-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  4. 35-We polymer electrolyte membrane fuel cell system for notebook computer using a compact fuel processor

    Science.gov (United States)

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

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

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-10-15

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

  8. Modeling and Simulation for Fuel Cell Polymer Electrolyte Membrane

    Directory of Open Access Journals (Sweden)

    Takahiro Hayashi

    2013-01-01

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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

    Li Mingqiang; Scott, Keith

    2010-01-01

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

  11. An all-aromatic polypyridine: Monomer and polymer synthesis; Film formation and crosslinking; A candidate fuel cell membrane

    Science.gov (United States)

    Sikkema, Doetze J.; Versteegen, Ron M.; Pouderoijen, Maarten J.; Janssen, Henk M.; Boere, Ben; Brands, Ferry; Kemperman, GerJan; Rewinkel, Jos B. M.; Koeman, Menno

    2018-03-01

    2,6-di (3-pyridyl)phenol and the title polymer are synthesized at 1 kg scale. Polymer is processed and crosslinked without the introduction of non-aromatic moieties after shaping into membranes. Attractive proton conduction, at high temperature (140-180 °C: 300 mS cm-1) and at room temperature (60 mS cm-1) are recorded in the dry state (higher numbers at modest humidity) and excellent retention of properties after challenge by humidity (in contrast with state-of-the-art PBI membranes). Functional fuel cells are made and tested. In prolonged use the membrane is plasticized and this seems attributable to curing reversal at the hydrogen electrode. For high temperature fuel cell use, another curing scheme (again without the introduction of aliphatic character) must be found.

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

    Energy Technology Data Exchange (ETDEWEB)

    Vath, Andreas

    2008-12-15

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

  13. 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.

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

    Science.gov (United States)

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

    2012-12-18

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

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

    Science.gov (United States)

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

    2013-05-01

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

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

    DEFF Research Database (Denmark)

    Jeong, Gisu; Kim, MinJoong; Han, Junyoung

    2016-01-01

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

  17. Fuel cell electrolyte membrane with basic polymer

    Science.gov (United States)

    Larson, James M.; Pham, Phat T.; Frey, Matthew H.; Hamrock, Steven J.; Haugen, Gregory M.; Lamanna, William M.

    2012-12-04

    The present invention is an electrolyte membrane comprising an acid and a basic polymer, where the acid is a low-volatile acid that is fluorinated and is either oligomeric or non-polymeric, and where the basic polymer is protonated by the acid and is stable to hydrolysis.

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

    International Nuclear Information System (INIS)

    Karimi, G.; Li, X.

    2005-01-01

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

  19. 35-We polymer electrolyte membrane fuel cell system for notebook computer using a compact fuel processor

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-10-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Dimitrios C. Papageorgopoulos

    2012-12-01

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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  4. 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.

  5. Cationic Polymers Developed for Alkaline Fuel Cell Applications

    Science.gov (United States)

    2015-01-20

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

  6. New polymer electrolytes for low temperature fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sundholm, F.; Elomaa, M.; Ennari, J.; Hietala, S.; Paronen, M. [Univ. of Helsinki (Finland). Lab. of Polymer Chemistry

    1998-12-31

    Proton conducting polymer membranes for demanding applications, such as low temperature fuel cells, have been synthesised and characterised. Pre-irradiation methods are used to introduce sulfonic acid groups, directly or using polystyrene grafting, in stable, preformed polymer films. The membranes produced in this work show promise for the development of cost-effective, highly conducting membranes. (orig.)

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

    Science.gov (United States)

    Mishler, Jeffrey Harris

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

  8. HIGH TEMPERATURE POLYMER FUEL CELLS

    DEFF Research Database (Denmark)

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

    2003-01-01

    This paper will report recent results from our group on polymer fuel cells (PEMFC) based on the temperature resistant polymer polybenzimidazole (PBI), which allow working temperatures up to 200°C. The membrane has a water drag number near zero and need no water management at all. The high working...

  9. Near-ambient solid polymer fuel cell

    Science.gov (United States)

    Holleck, G. L.

    1993-01-01

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

  10. Nanostructured polymer membranes for proton conduction

    Science.gov (United States)

    Balsara, Nitash Pervez; Park, Moon Jeong

    2013-06-18

    Polymers having an improved ability to entrain water are characterized, in some embodiments, by unusual humidity-induced phase transitions. The described polymers (e.g., hydrophilically functionalized block copolymers) have a disordered state and one or more ordered states (e.g., a lamellar state, a gyroid state, etc.). In one aspect, the polymers are capable of undergoing a disorder-to-order transition while the polymer is exposed to an increasing temperature at a constant relative humidity. In some aspects the polymer includes a plurality of portions, wherein a first portion forms proton-conductive channels within the membrane and wherein the channels have a width of less than about 6 nm. The described polymers are capable of entraining and preserving water at high temperature and low humidity. Surprisingly, in some embodiments, the polymers are capable of entraining greater amounts of water with the increase of temperature. The polymers can be used in Polymer Electrolyte Membranes in fuel cells.

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

    DEFF Research Database (Denmark)

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

    2001-01-01

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

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

    DEFF Research Database (Denmark)

    Berning, Torsten; Kær, Søren Knudsen

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-03-01

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

  14. 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)

  15. High Temperature Polymers for use in Fuel Cells

    Science.gov (United States)

    Peplowski, Katherine M.

    2004-01-01

    NASA Glenn Research Center (GRC) is currently working on polymers for fuel cell and lithium battery applications. The desire for more efficient, higher power density, and a lower environmental impact power sources has led to interest in proton exchanges membrane fuels cells (PEMFC) and lithium batteries. A PEMFC has many advantages as a power source. The fuel cell uses oxygen and hydrogen as reactants. The resulting products are electricity, heat, and water. The PEMFC consists of electrodes with a catalyst, and an electrolyte. The electrolyte is an ion-conducting polymer that transports protons from the anode to the cathode. Typically, a PEMFC is operated at a temperature of about 80 C. There is intense interest in developing a fuel cell membrane that can operate at higher temperatures in the range of 80 C- 120 C. Operating the he1 cell at higher temperatures increases the kinetics of the fuel cell reaction as well as decreasing the susceptibility of the catalyst to be poisoned by impurities. Currently, Nafion made by Dupont is the most widely used polymer membrane in PEMFC. Nafion does not function well above 80 C due to a significant decrease in the conductivity of the membrane from a loss of hydration. In addition to the loss of conductivity at high temperatures, the long term stability and relatively high cost of Nafion have stimulated many researches to find a substitute for Nafion. Lithium ion batteries are popular for use in portable electronic devices, such as laptop computers and mobile phones. The high power density of lithium batteries makes them ideal for the high power demand of today s advanced electronics. NASA is developing a solid polymer electrolyte that can be used for lithium batteries. Solid polymer electrolytes have many advantages over the current gel or liquid based systems that are used currently. Among these advantages are the potential for increased power density and design flexibility. Automobiles, computers, and cell phones require

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-12-01

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

  17. 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

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

    DEFF Research Database (Denmark)

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

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

  19. 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].

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

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  1. Development of the sulphonated poly(2,6-Dimethyl-1,4-Phenylene Oxide) membranes for proton exchange membranes fuel cells

    International Nuclear Information System (INIS)

    Ebrasu, Daniela; Petreanu, Irina; Iordache, Ioan; Stefanescu, Ioan; Gaspar, Costinela-Laura; Militaru, Daniela

    2008-01-01

    Full text: Fuel cells have the potential to become an important energy conversion technology. Research efforts directed toward the widespread commercialization of fuel cells have accelerated the developing of new types of Proton Exchange Membranes (also termed 'polymer electrolyte membranes') (PEM). Common issues critical to all high performance proton exchange membranes include: - high protonic conductivity; - low electronic conductivity; - low permeability to fuel and oxidant; - low water transport through diffusion and electro-osmosis; - oxidative and hydrolytic stability; - good mechanical properties in both the dry and hydrated states; - cost; and capability for fabrication into Membrane Electrode Assemblies (MEAs). In this sense we choose to use poly(2,6-Dimethyl-1,4-Phenylene Oxide) (PPO) as basis for development of new PEM membranes. The membranes were prepared by lamination from solution (Doctor Balde) method in controlled atmosphere (preliminary vacuum 0.003 Torr and/or nitrogen). FTIR spectra of the sulphonated polymers prove the sulphonic groups presence according the literature. Ionic exchange capacity (IEC) have the values 1.15-3.6 meq/g. TGA-DSC analysis put in evidence the thermal degradation of the sulphonated polymers at about 120 deg. C. These properties of the sulphonated PPO are in accordance of the requirements for PEM membranes and indicate that this polymer is suitable for PEM Fuel cells. (authors)

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

    Science.gov (United States)

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

    2017-11-01

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

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

    KAUST Repository

    Hussaini, I.S.

    2010-06-01

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

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

    Science.gov (United States)

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

    2017-10-01

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

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

    Science.gov (United States)

    Kamino, Takeo; Yaguchi, Toshie; Shimizu, Takahiro

    2017-10-01

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

  6. Study of poly(vinyl alcohol)/titanium oxide composite polymer membranes and their application on alkaline direct alcohol fuel cell

    Science.gov (United States)

    Yang, Chun-Chen; Chiu, Shwu-Jer; Lee, Kuo-Tong; Chien, Wen-Chen; Lin, Che-Tseng; Huang, Ching-An

    The novel poly(vinyl alcohol)/titanium oxide (PVA/TiO 2) composite polymer membrane was prepared using a solution casting method. The characteristic properties of the PVA/TiO 2 composite polymer membrane were investigated by thermal gravimetric analysis (TGA), a scanning electron microscopy (SEM), a micro-Raman spectroscopy, a methanol permeability measurement and the AC impedance method. An alkaline direct alcohol (methanol, ethanol and isopropanol) fuel cell (DAFC), consisting of an air cathode based on MnO 2/C inks, an anode based on PtRu (1:1) black and a PVA/TiO 2 composite polymer membrane, was assembled and examined for the first time. The results indicate that the alkaline DAFC comprised of a cheap, non-perfluorinated PVA/TiO 2 composite polymer membrane shows an improved electrochemical performances. The maximum power densities of alkaline DAFCs with 4 M KOH + 2 M CH 3OH, 2 M C 2H 5OH and 2 M isopropanol (IPA) solutions at room temperature and ambient air are 9.25, 8.00, and 5.45 mW cm -2, respectively. As a result, methanol shows the highest maximum power density among three alcohols. The PVA/TiO 2 composite polymer membrane with the permeability values in the order of 10 -7 to 10 -8 cm 2 s -1 is a potential candidate for use on alkaline DAFCs.

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

    CSIR Research Space (South Africa)

    Luo, H

    2010-08-31

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

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

    Science.gov (United States)

    Millett, Stephen; Mahadevan, Kathya

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-04-19

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

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

    Science.gov (United States)

    Shore, Lawrence [Edison, NJ

    2012-02-28

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

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

    Directory of Open Access Journals (Sweden)

    Zidong Wei

    2009-11-01

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

  13. Protic Salt Polymer Membranes: High-Temperature Water-Free Proton-Conducting Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Gervasio, Dominic Francis [Univ. of Arizona, Tucson, AZ (United States)

    2010-09-30

    This research on proton-containing (protic) salts directly addresses proton conduction at high and low temperatures. This research is unique, because no water is used for proton ionization nor conduction, so the properties of water do not limit proton fuel cells. A protic salt is all that is needed to give rise to ionized proton and to support proton mobility. A protic salt forms when proton transfers from an acid to a base. Protic salts were found to have proton conductivities that are as high as or higher than the best aqueous electrolytes at ambient pressures and comparable temperatures without or with water present. Proton conductivity of the protic salts occurs providing two conditions exist: i) the energy difference is about 0.8 eV between the protic-salt state versus the state in which the acid and base are separated and 2) the chemical constituents rotate freely. The physical state of these proton-conducting salts can be liquid, plastic crystal as well as solid organic and inorganic polymer membranes and their mixtures. Many acids and bases can be used to make a protic salt which allows tailoring of proton conductivity, as well as other properties that affect their use as electrolytes in fuel cells, such as, stability, adsorption on catalysts, environmental impact, etc. During this project, highly proton conducting (~ 0.1S/cm) protic salts were made that are stable under fuel-cell operating conditions and that gave highly efficient fuel cells. The high efficiency is attributed to an improved oxygen electroreduction process on Pt which was found to be virtually reversible in a number of liquid protic salts with low water activity (< 1% water). Solid flexible non-porous composite membranes, made from inorganic polymer (e.g., 10%indium 90%tin pyrophosphate, ITP) and organic polymer (e.g., polyvinyl pyridinium phosphate, PVPP), were found that give conductivity and fuel cell performances similar to phosphoric acid electrolyte with no need for hydration at

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  15. Characterization of polymer electrolytes for fuel cell applications

    International Nuclear Information System (INIS)

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

    1992-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Lei Mao

    2017-09-01

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

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

    Science.gov (United States)

    Licoccia, Silvia; Traversa, Enrico

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

  18. Selectivity of Direct Methanol Fuel Cell Membranes

    Directory of Open Access Journals (Sweden)

    Antonino S. Aricò

    2015-11-01

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

  19. Selectivity of Direct Methanol Fuel Cell Membranes.

    Science.gov (United States)

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

    2015-11-24

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

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

    DEFF Research Database (Denmark)

    Thomas, Sobi; Bates, Alex; Park, Sam

    2016-01-01

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

  1. Microstructured Electrolyte Membranes to Improve Fuel Cell Performance

    Science.gov (United States)

    Wei, Xue

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

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

    DEFF Research Database (Denmark)

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

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

  3. Synthesis and characterisation of alkaline anionic-exchange membranes for direct alcohol fuel cells

    CSIR Research Space (South Africa)

    Nonjola, P

    2007-12-01

    Full Text Available , but the most important being proton exchange membrane fuel cell (PEMFC), which uses an acidic membrane like Nafion (sulfonated fluorocarbon polymers) as an electrolyte. The use of polymer electrolytes represents an interesting path to pursue...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-03-15

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

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

    DEFF Research Database (Denmark)

    Liao, Jianhui; Yang, Jingshuai; Li, Qingfeng

    2013-01-01

    Phosphoric acid doped polybenzimidazole membranes have been explored as proton exchange membranes for high temperature polymer electrolyte membrane fuel cells. Long-term durability of the membrane is of critical concern and has been evaluated by accelerated degradation tests under Fenton conditions...... of the polymer. Fuel cell durability tests with contaminations of ferrous ions did show considerable performance degradation, however, primarily due to the catalyst deterioration rather than the membrane degradation........ In this study effects of phosphoric acid and ferrous ions were investigated by measurements of the weight loss, intrinsic viscosity and size exclusion chromatography (SEC) of the polymer membranes. Ferrous ions resulted in, as expected, catalytic formation of peroxide radicals and hence the accelerated polymer...

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

    Energy Technology Data Exchange (ETDEWEB)

    Zedda, Marco

    2011-05-12

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

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

    DEFF Research Database (Denmark)

    Li, Qingfeng; Jensen, Jens Oluf

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

  8. New proton conducting membranes for fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Sukumar, P.R.

    2006-07-01

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

  9. New proton conducting membranes for fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Sukumar, P R

    2006-07-01

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

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-15

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

  12. based anion exchange membrane for alkaline polymer electrolyte

    Indian Academy of Sciences (India)

    Administrator

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

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

    Directory of Open Access Journals (Sweden)

    Passos Raimundo R.

    2002-01-01

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  15. Polybenzimidazoles based on high temperature polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

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

    Directory of Open Access Journals (Sweden)

    A.A. Abd El Monem

    2014-03-01

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

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

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Nielsen, Mads Pagh

    2015-01-01

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

  18. Sulfonation and characterization of styrene-indene copolymers for the development of proton conducting polymer membranes

    Directory of Open Access Journals (Sweden)

    Cristiane M. Becker

    2012-01-01

    Full Text Available The aim of this work is to obtain polymer precursors based on styrene copolymers with distinct degrees of sulfonation, as an alternative material for fuel cell membranes. Acetyl sulfate was used to carry out the sulfonation and the performance of the polyelectrolyte was evaluated based on the content of acid polar groups incorporated into the macromolecular chain. Polymeric films were produced by blending the sulfonated styrene-indene copolymer with poly(vinylidene fluoride. The degree of sulfonation of the polymer was strongly affected by the sulfonation reaction parameters, with a direct impact on the ionic exchange capacity and the ionic conductivity of the sulfonated polymers and the membranes obtained from them. The films produced with the blends showed more suitable mechanical properties, although the conductivity of the membranes was still lower than that of commercially available membranes used in fuel cells.

  19. Physicochemical properties of phosphoric acid doped polybenzimidazole membranes for fuel cells

    DEFF Research Database (Denmark)

    He, Ronghuan; Li, Qingfeng; Bach, Anders

    2006-01-01

    of the polymer, a level necessary to obtain high enough proton conductivity for fuel cell uses, the polymer membrane exhibits a volume swelling by 118%, resulting in separation of the polymer backbones. The separation in turn reduces the mechanical strength of the membrane especially at high temperatures....... Another consequence is the increased H2 and O2 permeability through the membrane. In the temperature range from 120 to 180 ◦C, the hydrogen permeability was found to be 1.6–4.3×10−17 and 1.2–4.0×10−15 mol cm cm−2 s−1 Pa−1 for pristine and acid doped PBI membranes, respectively, while for oxygen it was 5...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-01

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

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

    DEFF Research Database (Denmark)

    Yang, Jingshuai; Li, Xueyuan; Xu, Yizin

    2013-01-01

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

  2. Catalytic membranes for CO oxidation in fuel cells

    Science.gov (United States)

    Sandi-Tapia, Giselle; Carrado Gregar, Kathleen; Kizilel, Riza

    2010-06-08

    A hydrogen permeable membrane, which includes a polymer stable at temperatures of about 200 C having clay impregnated with Pt or Au or Ru or Pd particles or mixtures thereof with average diameters of less than about 10 nanometers (nms) is disclosed. The membranes are useful in fuel cells or any device which requires hydrogen to be separated from carbon monoxide.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-07-01

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

  4. Catalytic phosphonation of high performance polymers and POSS. Novel components for polymer blend and nanocomposite fuel cell membranes

    Energy Technology Data Exchange (ETDEWEB)

    Bock, T.R.

    2006-10-15

    Aim of this thesis was the preparation and evaluation of phosphonated high performance (HP) polyelectrolytes and polyhedral oligomeric silsesquioxanes (POSS) for polyelectrolyte membrane fuel cell (PEMFC) application. Brominated derivatives of the commercial high performance (HP) polymers poly(ethersulfone) (PES), poly(etheretherketone) (PEEK), poly(phenylsulfone) (PPSu), poly(sulfone) (PSU) and of octaphenyl-POSS of own production were phosphonated by Ni-catalysed Arbuzov reaction. Phosphonated PSU was cast into pure and blend films with sulfonated PEEK (s-PEEK) to investigate H+-conductivity, water uptake and film morphology. Blend films' properties were referenced to films containing unmodified blend partners. Solution-compounding of phosphonated octaphenyl-POSS and s-PEEK was used to produce novel nanocomposite films. An in-situ zirconisation method was assessed as convenient strategy for novel ionically crosslinked membranes of enhanced swelling resistance. Dibromo isocyanuric acid (DBI) and N-bromo succinimide (NBS) as brominating agents allowed polymer analogous preparation of the novel brominated PES and PEEK with precise reaction control. A random distribution of functional groups, i.e. polyelectrolytes' microstructural homogeneity was revealed as decisive factor concerning solubility of phosphonated PSU. Brominated phT8 was prepared with Br2 by a high temperature approach in tetrachloroethane (TCE). Brominated polymers were phosphonated by Ni-catalysis in non-coordinating high temperature solvents, such as diphenylether, benzophenone and diphenylsulfone without notable solvent influence. The lack of solvent - catalyst complexes and high reaction temperatures of 180-200 C led to halogen-free phosphonates with unprecedented high functionalities. Polymer analogous application of P(OSiMe3)3 offered a novel direct access to easily cleavable disilyl ester derivatives. These were obtained from PEEK and PSU in near quantitative yields at NiCl2-loads as

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

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

    Science.gov (United States)

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

    2014-03-01

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

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    the oxidative degradation of the polymer membrane was studied under the Fenton test conditions by the weight loss, intrinsic viscosity, size exclusion chromatography, scanning electron microscopy and Fourier transform infrared spectroscopy. During the Fenton test, significant weight losses depending...... 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......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...

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

    Science.gov (United States)

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

    2018-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-04-15

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

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

    International Nuclear Information System (INIS)

    Ramirez-Salgado, Joel

    2007-01-01

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

  11. Introducing catalyst in alkaline membrane for improved performance direct borohydride fuel cells

    Science.gov (United States)

    Qin, Haiying; Lin, Longxia; Chu, Wen; Jiang, Wei; He, Yan; Shi, Qiao; Deng, Yonghong; Ji, Zhenguo; Liu, Jiabin; Tao, Shanwen

    2018-01-01

    A catalytic material is introduced into the polymer matrix to prepare a novel polymeric alkaline electrolyte membrane (AEM) which simultaneously increases ionic conductivity, reduces the fuel cross-over. In this work, the hydroxide anion exchange membrane is mainly composed of poly(vinylalcohol) and alkaline exchange resin. CoCl2 is added into the poly(vinylalcohol) and alkaline exchange resin gel before casting the membrane to introduce catalytic materials. CoCl2 is converted into CoOOH after the reaction with KOH solution. The crystallinity of the polymer matrix decreases and the ionic conductivity of the composite membrane is notably improved by the introduction of Co-species. A direct borohydride fuel cell using the composite membrane exhibits an open circuit voltage of 1.11 V at 30 °C, which is notably higher than that of cells using other AEMs. The cell using the composite membrane achieves a maximum power density of 283 mW cm-2 at 60 °C while the cell using the membrane without Co-species only reaches 117 mW cm-2 at the same conditions. The outstanding performance of the cell using the composite membrane benefits from impregnation of the catalytic Co-species in the membrane, which not only increases the ionic conductivity but also reduces electrode polarization thus improves the fuel cell performance. This work provides a new approach to develop high-performance fuel cells through adding catalysts in the electrolyte membrane.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-27

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  14. Proton Conducting Polymer Membrane Comprised of 2-Acrylamido-2-Methylpropanesulfonic Acid

    National Research Council Canada - National Science Library

    Walker, Charles

    2002-01-01

    In order to identify a proton-conducting polymer membrane suitable for replacing Nafion 117 in direct methanol fuel cells, we prepared a cross-linked copolymer of hydrophilic 2-acrylamido-2-methylpropanesulfonic acid (AMPS...

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

    Energy Technology Data Exchange (ETDEWEB)

    Abuin, Graciela C. [Centro de Procesos Superficiales, Instituto Nacional de Tecnologia Industrial (INTI), Av. Gral. Paz 5445, B1650KNA, San Martin, Buenos Aires (Argentina); Nonjola, Patrick; Mathe, Mkhulu K. [Council for Scientific and Industrial Research (CSIR), Material Science and Manufacturing, PO Box 395, Brumeria, Pretoria 0001 (South Africa); Franceschini, Esteban A.; Izraelevitch, Federico H.; Corti, Horacio R. [Departamento de Fisica de la Materia Condensada, Comision Nacional de Energia Atomica (CNEA), Av. Gral. Paz 1499, B1650KNA, San Martin, Buenos Aires (Argentina)

    2010-06-15

    Ammonium quaternized polymers such as poly (arylene ether sulfones) are being developed and studied as candidates of ionomeric materials for application in alkaline fuel cells, due to their low cost and promising electrochemical properties. In this work, a quaternary ammonium polymer was synthesized by chloromethylation of a commercial polysulfone followed by amination process. Quaternized polysulfone membrane properties such us water and water-methanol uptake, electrical conductivity and Young'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 to Nafion. The specific conductivity of the fully hydrated polysulfone membrane equilibrated with KOH solutions at ambient temperature increases with the KOH concentration, reaching a maximum of 0.083 S cm{sup -1} for 2 M KOH, slightly less conductive than Nafion 117. The elastic modulus of the polysulfone membranes inmersed in water is similar to that reported for Nafion membranes under the same conditions. We concluded that quaternized polysulfone membrane are good candidates as electrolytes in alkaline direct methanol fuel cells. (author)

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  17. Dendronized Polymer Architectures for Fuel Cell Membranes

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  18. Durability study and lifetime prediction of baseline proton exchange membrane fuel cell under severe operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Marrony, M.; Quenet, S.; Aslanides, A. [European Institute for Energy Research, Emmy-Noether Strasse 11, 76131 Karlsruhe (Germany); Barrera, R.; Ginocchio, S.; Montelatici, L. [Edison, Via Giorgio La Pira 2, 10028 Trofarello (Italy)

    2008-08-01

    Comparative studies of mechanical and electrochemical properties of Nafion{sup registered} - and sulfonated polyetheretherketone polymer-type membranes are carried out under severe fuel cell conditions required by industrials, within stationary and cycling electric load profiles. These membranes are proposed to be used in PEM between 70 and 90 C as fluorinated or non-fluorinated baseline membranes, respectively. Thus, though the performance of both membranes remains suitable, Nafion{sup registered} backbone brought better mechanical properties and higher electrochemical stabilities than sulfonated polyetheretherketone backbone. The performance stability and the mechanical strength of the membrane-electrode assembly were shown to be influenced by several intrinsic properties of the membrane (e.g., thermal pre-treatment, thickness) and external conditions (fuel cell operating temperature, relative humidity). Finally, a lifetime prediction for membranes under stationary conditions is proposed depending on the operation temperature. At equivalent thicknesses (i.e. 50 {mu}m), Nafion{sup registered} membranes were estimated able to operate into the 80-90 C range while sulfonated polyetheretherketone would be limited into the 70-80 C range. This approach brings baseline information about the capability of these types of polymer electrolyte membrane under fuel cell critical operations. Finally, it is revealed as a potential tool for the selection of the most promising advanced polymers for the ensuing research phase. (author)

  19. Sulfonated PEEK and fluorinated polymer based blends for fuel cell applications: Investigation of the effect of type and molecular weight of the fluorinated polymers on the membrane's properties

    Energy Technology Data Exchange (ETDEWEB)

    Inan, Tuelay Y.; Dogan, Hacer; Unveren, Elif E. [The Scientific and Technological Research Council of Turkey (TUBITAK), Marmara Research Center, Chemistry Institute, 41470 Gebze, Kocaeli (Turkey); Eker, Ersoy [Tuerk Demirdoekuem Fabrikalari A.S., 11300 Bozueyuek, Bilecik (Turkey)

    2010-11-15

    This work clearly demonstrates the effect of the type and molecular weight of the fluorinated polymer of SPEEK/Fluorinated polymer blends for low temperature (<80 C) Fuel Cell Applications. Comparisons with trademarks (e.g., Nafion {sup registered}) suggests that the membranes we have prepared in this study have good compatibility in all application respects. Membranes were prepared by solution casting method from four different fluorinated polymers; poly (vinylidene fluoride) with three different molecular weights (PVDF, M{sub w}: 180.000, M{sub w}: 275.000, M{sub w}: 530.000); Poli(vinylidene fluoride-co-Hexafluoro propylen) (PVDF-HFP M{sub n}:130.000) and sulfonated poly(ether ether ketone) (SPEEK) with sulfonation degree (SD) of 70. The sulfonation degree (SD) of SPEEK was determined by FTIR, {sup 1}H NMR and ion exchange capacity (IEC) measurements. Thermo-oxidative stability and proton conductivity of the membranes were determined by using thermal gravimetric analysis (TGA) and BT-512 BekkTech membrane test systems, respectively. Chemical degradation of SPEEK membranes was investigated via Fenton test. The morphology of the membranes were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Water uptake and proton conductivity values decreased with the addition of fluorinated polymers (PVDF, PVDF-HFP) as expected, but proton conductivity values were still comparable to that of Nafion 117 {sup registered} membrane. Addition of fluorinated polymers improved chemical degradation of the blend membranes in all ratios while addition of PVDF-HFP to the SPEEK70 caused phase separations in all ratios. Methanol permeability value of SPEEK70/PVDF(M{sub w} = 275.000) blend membrane (3.13E-07 (cm{sup 2}/s)) was much lower than Nafion 117 {sup registered} (1.21E-06 (cm{sup 2}/s)). PVDF addition to the SPEEK polymers caused increase in elongation of the membranes. Increase in the molecular weight of the PVDF did not show any effect on

  20. Poly (ether ether ketone) membranes for fuel cells

    International Nuclear Information System (INIS)

    Marrero, Jacqueline C.; Gomes, Ailton de S.; Filho, Jose C.D.; Hui, Wang S.; Oliveira, Vivianna S. de

    2015-01-01

    Polymeric membranes were developed using a SPEEK polymer matrix (sulphonated poly (ether ether ketone)), containing hygroscopic particles of zirconia (Zr) (incorporated by sol-gel method), for use as electrolyte membranes in fuel cells. SPEEK with different sulfonation degrees were used: 63 and 86%. The thermal analysis (TGA and DSC) was carried out to characterize the membranes and electrochemical impedance spectroscopy (EIS) was carried out to evaluating the proton conductivity of the membranes. Additional analysis were underway in order to characterize these membranes, which include: X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in order to evaluate the influence of zirconia and sulfonation degree on the properties of the membranes. (author)

  1. Degradation mechanisms of sulfonated poly-aromatic membranes in fuel cell

    International Nuclear Information System (INIS)

    Perrot, C.

    2006-11-01

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

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

    DEFF Research Database (Denmark)

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

    2003-01-01

    The technical achievement and challenges for the PEMFC technology based on perfluorosulfonic acid (PFSA) polymer membranes (e.g. Nafion®) are briefly discussed. The newest development in the field is alternative polymer electrolytes for operation above 100°C. As one of the successful approaches...... to high operational temperatures, the development and evaluation of acid doped PBI membranes are reviewed, covering polymer synthesis, membrane casting, acid doping, physiochemical characterization and fuel cell tests. A high temperature PEMFC system operational at up to 200°C is demonstrated with no gas...... humidification and high CO-tolerance up to 10 vol%. This high CO tolerance allows for a direct use of reformed hydrogen without further CO removal, which opens the possibility for an integrated reformer-fuel cell system. The content of this review is to a large extent based on research performed by the authors...

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

    NARCIS (Netherlands)

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

    2002-01-01

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

  4. 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.

  5. 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 less than proton exchange membrane systems using alcohol as fuel. Many anion exchange membranes based on quaternised polymers have been developed and studied for AMFC3-5. The quaternary ammonium functional groups are the anion conductors...

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

    Science.gov (United States)

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

    2012-01-01

    In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane. PMID:24958295

  7. Plasma membranes modified by plasma treatment or deposition as solid electrolytes for potential application in solid alkaline fuel cells.

    Science.gov (United States)

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

    2012-07-30

    In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane.

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

    Science.gov (United States)

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

    2017-06-01

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

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

    Science.gov (United States)

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

    2016-08-01

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

  10. Structural and Morphological Features of Acid-Bearing Polymers for PEM Fuel Cells

    DEFF Research Database (Denmark)

    Yang, Yunsong; Siu, Ana; Peckham, Timothy J.

    2008-01-01

    Chemical structure, polymer microstructure, sequence distribution, and morphology of acid-bearing polymers are important factors in the design of polymer electrolyte membranes (PEMs) for fuel cells. The roles of ion aggregation and phase separation in vinylic- and aromatic-based polymers in proton...... conductivity and water transport are described. The formation, dimensions, and connectivity of ionic pathways are consistently found to play an important role in determining the physicochemical properties of PEMs. For polymers that possess low water content, phase separation and ionic channel formation...

  11. Grafted functional groups on expanded tetrafluoroethylene (ePTFE) support for fuel cell and water transport membranes

    Science.gov (United States)

    Fuller, Timothy J.; Jiang, Ruichun

    2017-01-24

    A method for forming a modified solid polymer includes a step of contacting a solid fluorinated polymer with a sodium sodium-naphthalenide solution to form a treated fluorinated solid polymer. The treated fluorinated solid polymer is contacted with carbon dioxide, sulfur dioxide, or sulfur trioxide to form a solid grafted fluorinated polymer. Characteristically, the grafted fluorinated polymer includes appended CO.sub.2H or SO.sub.2H or SO.sub.3H groups. The solid grafted fluorinated polymer is advantageously incorporated into a fuel cell as part of the ion-conducting membrane or a water transport membrane in a humidifier.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-01

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

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

    International Nuclear Information System (INIS)

    Uctug, Fehmi Goerkem; Holmes, Stuart M.

    2011-01-01

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

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

    DEFF Research Database (Denmark)

    Yang, Jingshuai; Aili, David; Li, Qingfeng

    2013-01-01

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

  15. Novel composite membranes based on PBI and dicationic ionic liquids for high temperature polymer electrolyte membrane fuel cells

    International Nuclear Information System (INIS)

    Hooshyari, Khadijeh; Javanbakht, Mehran; Adibi, Mina

    2016-01-01

    Two types of innovative composite membranes based on polybenzimidazole (PBI) containing dicationic ionic liquid 1,3-di(3-methylimidazolium) propane bis (trifluoromethylsulfonyl) imide (PDC 3 ) and monocationic ionic liquid 1-hexyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide (PMC 6 ) are prepared as electrolyte for high temperature fuel cells applications under anhydrous conditions. The analyses of results display promising characteristics such as high proton conductivity and thermal stability. Moreover the fuel cell performance of PA doped PDC 3 composite membranes is enhanced in comparison with PA doped PMC 6 and PA doped PBI membranes at high temperatures. Dicationic ionic liquid with high number of charge carriers provides well-developed ionic channels which form facile pathways and considerably develop the anhydrous proton conductivity. The highest proton conductivity of 81 mS/cm is achieved for PA doped PDC 3 composite membranes with PBI/IL mole ratio: 4 at 180 °C. A power density of 0.44 W/cm 2 is obtained at 0.5 V and 180 °C for PA doped PDC 3 composite membranes, which proves that these developed composite membranes can be considered as most promising candidates for high temperature fuel cell applications with enhanced proton conductivity.

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

    International Nuclear Information System (INIS)

    Tiss, Faysal; Chouikh, Ridha; Guizani, Amenallah

    2013-01-01

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

  17. Oxygen permeation through Nafion 117 membrane and its impact on efficiency of polymer membrane ethanol fuel cell

    Science.gov (United States)

    Jablonski, Andrzej; Kulesza, Pawel J.; Lewera, Adam

    2011-05-01

    We investigate oxygen permeation through Nafion 117 membrane in a direct ethanol fuel cell and elucidate how it affects the fuel cell efficiency. An obvious symptom of oxygen permeation is the presence of significant amounts of acetaldehyde and acetic acid in the mixture leaving anode when no current was drawn from the fuel cell (i.e. under the open circuit conditions). This parasitic process severely lowers efficiency of the fuel cell because ethanol is found to be directly oxidized on the surface of catalyst by oxygen coming through membrane from cathode in the absence of electric current flowing in the external circuit. Three commonly used carbon-supported anode catalysts are investigated, Pt, Pt/Ru and Pt/Sn. Products of ethanol oxidation are determined qualitatively and quantitatively at open circuit as a function of temperature and pressure, and we aim at determining whether the oxygen permeation or the catalyst's activity limits the parasitic ethanol oxidation. Our results strongly imply the need to develop more selective membranes that would be less oxygen permeable.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  19. The next generation fuel cells: anion exchange membrane fuel cells (AEMFC)

    International Nuclear Information System (INIS)

    Tauqir, A.; Zahoor, S.

    2013-01-01

    Many environmentally friendly alternatives (solar, wind, hydroelectric, and geothermal power) can only be used in particular environments. In contrast, fuel cells can have near-zero emissions, are quiet and efficient, and can work in any environment where the temperature is lower than the cell's operating temperature. Among various types of fuel cells, the AEMFC is the most recent one and has advantages such as excellent performance compared to other candidate fuel cells due to its active O/sub 2/ electrode kinetics and flexibility to use a wide range of electro-catalysts such as silver and nickels contrary to expensive one (Platinum) required for proton exchange membrane fuel cell (PEMFC). Anion exchange membrane (AEM) is a crucial part in AEMFC, determining durability and electrochemical performances of membrane electrode assembly (MEA). The role of an AEM is to conduct hydroxyl ions from cathode to anode. If this conduction is not sufficiently high and selective, the corresponding fuel cell will not find any practical application. One of the major problems associated with AEMFC is much lower conductivities of anion compare to proton conductivity in PEMFCs, even upon similar working condition. Thus AEMs is only practical, if it is chemically and mechanically stable against severe basic operation conditions and highly hydroxyl ions conductive. The conventional AEMs based on animated aliphatic and aromatic hydrocarbon or even fluorinated polymers tend to be attacked by hydroxyl ions, causing the degradation during operation is strongly basic conditions. (author)

  20. 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

    -term durability with a degradation rate of 5Vh−1 has been achieved under continuous operation with hydrogen and air at 150–160 ◦C. With load or thermal cycling, a performance loss of 300V per cycle or 40Vh−1 per operating hour was observed. Further improvement should be done by, e.g. optimizing the thermal...... 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...

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

    Science.gov (United States)

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

    2018-02-01

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

  2. Biocatalytic Self-Cleaning Polymer Membranes

    Directory of Open Access Journals (Sweden)

    Agnes Schulze

    2015-09-01

    Full Text Available Polymer membrane surfaces have been equipped with the digestive enzyme trypsin. Enzyme immobilization was performed by electron beam irradiation in aqueous media within a one-step method. Using this method, trypsin was covalently and side-unspecific attached to the membrane surface. Thus, the use of preceding polymer functionalization and the use of toxic solvents or reagents can be avoided. The resulting membranes showed significantly improved antifouling properties as demonstrated by repeated filtration of protein solutions. Furthermore, the biocatalytic membrane can be simply “switched on” to actively degrade a fouling layer on the membrane surface and regain the initial permeability. The membrane pore structure (pore size and porosity was neither damaged by the electron beam treatment nor blocked by the enzyme loading, ensuring a stable membrane performance.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  5. Metal membrane-type 25-kW methanol fuel processor for fuel-cell hybrid vehicle

    Science.gov (United States)

    Han, Jaesung; Lee, Seok-Min; Chang, Hyuksang

    A 25-kW on-board methanol fuel processor has been developed. It consists of a methanol steam reformer, which converts methanol to hydrogen-rich gas mixture, and two metal membrane modules, which clean-up the gas mixture to high-purity hydrogen. It produces hydrogen at rates up to 25 N m 3/h and the purity of the product hydrogen is over 99.9995% with a CO content of less than 1 ppm. In this fuel processor, the operating condition of the reformer and the metal membrane modules is nearly the same, so that operation is simple and the overall system construction is compact by eliminating the extensive temperature control of the intermediate gas streams. The recovery of hydrogen in the metal membrane units is maintained at 70-75% by the control of the pressure in the system, and the remaining 25-30% hydrogen is recycled to a catalytic combustion zone to supply heat for the methanol steam-reforming reaction. The thermal efficiency of the fuel processor is about 75% and the inlet air pressure is as low as 4 psi. The fuel processor is currently being integrated with 25-kW polymer electrolyte membrane fuel-cell (PEMFC) stack developed by the Hyundai Motor Company. The stack exhibits the same performance as those with pure hydrogen, which proves that the maximum power output as well as the minimum stack degradation is possible with this fuel processor. This fuel-cell 'engine' is to be installed in a hybrid passenger vehicle for road testing.

  6. The Characteristic Thickness of Polymer Electrolyte Membrane and the

    Czech Academy of Sciences Publication Activity Database

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

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

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

    International Nuclear Information System (INIS)

    Park, Heesung

    2014-01-01

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

  9. 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)

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

    Science.gov (United States)

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

    2018-04-01

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

  11. A highly durable fuel cell electrocatalyst based on double-polymer-coated carbon nanotubes.

    Science.gov (United States)

    Berber, Mohamed R; Hafez, Inas H; Fujigaya, Tsuyohiko; Nakashima, Naotoshi

    2015-11-23

    Driven by the demand for the commercialization of fuel cell (FC) technology, we describe the design and fabrication of a highly durable FC electrocatalyst based on double-polymer-coated carbon nanotubes for use in polymer electrolyte membrane fuel cells. The fabricated electrocatalyst is composed of Pt-deposited polybenzimidazole-coated carbon nanotubes, which are further coated with Nafion. By using this electrocatalyst, a high FC performance with a power density of 375 mW/cm(2) (at 70 ˚C, 50% relative humidity using air (cathode)/H2(anode)) was obtained, and a remarkable durability of 500,000 accelerated potential cycles was recorded with only a 5% loss of the initial FC potential and 20% loss of the maximum power density, which were far superior properties compared to those of the membrane electrode assembly prepared using carbon black in place of the carbon nanotubes. The present study indicates that the prepared highly durable fuel cell electrocatalyst is a promising material for the next generation of PEMFCs.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  13. Polymer sulfonation- a versatile route to prepare proton-conducting membrane material for advanced technologies

    International Nuclear Information System (INIS)

    Zaidi, S.M.J.

    2003-01-01

    Sulfonation of polymers is a viable method for making proton exchange membranes used in electrochemical devices. Polyether-ether ketone was modified by using concentrated sulfuric acid (97.4%) to produce ion-containing polymers bearing HSO3 groups. The sulfonated polymer was characterized for IEC, HNMR, DSC and water uptake etc. The degree of sulfonation of sulfonated PEEK was found to vary from 40 to 80 mol%. The PEEK became amorphous after sufonation (as evidenced from DSC and WXRD), which enhanced its solubility in organic solvents such as DMF. The glass transition temperature, Tg increased from 151C for pure PEEK to 217C upon sulfonation. The water uptake was also increased with sulfonation level, which provides formation of water-mediated pathways for protons involving SO3H groups. The membranes from these polymers have a high potential for use in electrochemical devices such as polymer fuel cell and electrodialysis. (author)

  14. Electrochemical performance of an air-breathing direct methanol fuel cell using poly(vinyl alcohol)/hydroxyapatite composite polymer membrane

    Science.gov (United States)

    Yang, Chun-Chen; Chiu, Shwu-Jer; Lin, Che-Tseng

    A novel composite polymer membrane based on poly(vinyl alcohol)/hydroxyapatite (PVA/HAP) was successfully prepared by a solution casting method. The characteristic properties of the PVA/HAP composite polymer membranes were examined by thermal gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), micro-Raman spectroscopy and AC impedance method. An air-breathing DMFC, comprised of an air cathode electrode with MnO 2/BP2000 carbon inks on Ni-foam, an anode electrode with PtRu black on Ti-mesh, and the PVA/HAP composite polymer membrane, was assembled and studied. It was found that this alkaline DMFC showed an improved electrochemical performance at ambient temperature and pressure; the maximum peak power density of an air-breathing DMFC in 8 M KOH + 2 M CH 3OH solution is about 11.48 mW cm -2. From the application point of view, these composite polymer membranes show a high potential for the DMFC applications.

  15. Electrochemical performance of an air-breathing direct methanol fuel cell using poly(vinyl alcohol)/hydroxyapatite composite polymer membrane

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chun-Chen; Chiu, Shwu-Jer; Lin, Che-Tseng [Department of Chemical Engineering, Mingchi University of Technology, Taipei Hsien 243 (China)

    2008-02-15

    A novel composite polymer membrane based on poly(vinyl alcohol)/hydroxyapatite (PVA/HAP) was successfully prepared by a solution casting method. The characteristic properties of the PVA/HAP composite polymer membranes were examined by thermal gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), micro-Raman spectroscopy and AC impedance method. An air-breathing DMFC, comprised of an air cathode electrode with MnO{sub 2}/BP2000 carbon inks on Ni-foam, an anode electrode with PtRu black on Ti-mesh, and the PVA/HAP composite polymer membrane, was assembled and studied. It was found that this alkaline DMFC showed an improved electrochemical performance at ambient temperature and pressure; the maximum peak power density of an air-breathing DMFC in 8 M KOH + 2 M CH{sub 3}OH solution is about 11.48 mW cm{sup -2}. From the application point of view, these composite polymer membranes show a high potential for the DMFC applications. (author)

  16. From polymer chemistry to membrane elaboration

    Energy Technology Data Exchange (ETDEWEB)

    Iojoiu, C. [ERAS-Labo, 222 RN 90, F-38330 St. Nazaire-les-Eymes (France); Chabert, F.; Marechal, M.; Guindet, J.; Sanchez, J.-Y. [LEPMI ENSEEG, Domaine Universitaire, BP 75, F-38402 St. Martin d' Heres Cedex (France); Kissi, N.El. [Laboratoire de Rheologie, ENSHMG, Domaine Universitaire, BP 95, F-38402 St. Martin d' Heres Cedex (France)

    2006-02-28

    The paper tries to make a critical inventory of Ionomers, free of fluorine or fluorine less, which can be used as alternatives to Nafion{sup R} in polymer electrolytes fuel cells, as Ionomer is indisputably one of the main bolts of these technologies. All the Ionomer families are discussed, with their main advantages and drawbacks, in particular in terms of their possible industrial scale-up. Special attention has been paid to the discussions about the choice of the ionic functions and that of polymeric backbones of the Ionomers, with regard to the required electrochemical properties and also to their thermomechanical behaviour. It has been emphasized that a global approach of the polymer electrolytes is essential to progress. This must involve (i) a control of the syntheses up to the pilot scale, (ii) thorough characterizations, (iii) attention to the membrane and the MEA assembly and (iv) durability investigations, including post-mortem characterizations. (author)

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

    Science.gov (United States)

    Zhang, Lei

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

  18. 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

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

    Science.gov (United States)

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

    2016-12-01

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

  20. Synthesis and properties of imidazole-grafted hybrid inorganic-organic polymer membranes

    International Nuclear Information System (INIS)

    Li Siwen; Zhou Zhen; Liu Meilin; Li Wen; Ukai, Junzo; Hase, Kohei; Nakanishi, Masatsugu

    2006-01-01

    Imidazole rings were grafted on alkoxysilane with a simple nucleophilic substitute reaction to form hybrid inorganic-organic polymers with imidazole rings. Proton exchange membranes (PEM) based on these hybrid inorganic-organic polymers and H 3 PO 4 exhibit high proton conductivity and high thermal stability in an atmosphere of low relative humidity. The grafted imidazole rings improved the proton conductivity of the membranes in the high temperature range. It is found that the proton conductivities increase with H 3 PO 4 content and temperature, reaching 3.2 x 10 -3 S/cm at 110 deg. C in a dry atmosphere for a membrane with 1 mole of imidazole ring and 7 moles of H 3 PO 4 . The proton conductivity increases with relative humidity (RH) as well, reaching 4.3 x 10 -2 S/cm at 110 deg. C when the RH is increased to about 20%. Thermogravimetric analysis (TGA) indicates that these membranes are thermally stable up to 250 deg. C in dry air, implying that they have a good potential to be used as the membranes for high-temperature PEM fuel cells

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

    CSIR Research Space (South Africa)

    Luo, H

    2012-04-01

    Full Text Available and separating the fuel from oxidant. A polyperfluorosulfonic acid ionomer Nafion? (developed by Dupont) is the mostly used proton exchange membrane in PEMFCs, because of its high proton conductivity and excellent chemical stability [3, 4]. However, the high...-Methyl-2-pyrrolidinone. After the solution was homogenized by stirring, the polymer solution was cast on a glass Petri dish. The solvent was then removed in a vacuum oven at 130 ?C. The membrane was peeled off from the Petri dish. Thereafter...

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

    Energy Technology Data Exchange (ETDEWEB)

    Perrot, C

    2006-11-15

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

  3. 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.

  4. High-performance Fuel Cell with Stretched Catalyst-Coated Membrane: One-step Formation of Cracked Electrode.

    Science.gov (United States)

    Kim, Sang Moon; Ahn, Chi-Yeong; Cho, Yong-Hun; Kim, Sungjun; Hwang, Wonchan; Jang, Segeun; Shin, Sungsoo; Lee, Gunhee; Sung, Yung-Eun; Choi, Mansoo

    2016-05-23

    We have achieved performance enhancement of polymer electrolyte membrane fuel cell (PEMFC) though crack generation on its electrodes. It is the first attempt to enhance the performance of PEMFC by using cracks which are generally considered as defects. The pre-defined, cracked electrode was generated by stretching a catalyst-coated Nafion membrane. With the strain-stress property of the membrane that is unique in the aspect of plastic deformation, membrane electrolyte assembly (MEA) was successfully incorporated into the fuel cell. Cracked electrodes with the variation of strain were investigated and electrochemically evaluated. Remarkably, mechanical stretching of catalyst-coated Nafion membrane led to a decrease in membrane resistance and an improvement in mass transport, which resulted in enhanced device performance.

  5. Water-Free Proton-Conducting Membranes for Fuel Cells

    Science.gov (United States)

    Narayanan, Sekharipuram; Yen, Shiao-Pin

    2007-01-01

    Poly-4-vinylpyridinebisulfate (P4VPBS) is a polymeric salt that has shown promise as a water-free proton-conducting material (solid electrolyte) suitable for use in membrane/electrode assemblies in fuel cells. Heretofore, proton-conducting membranes in fuel cells have been made from perfluorinated ionomers that cannot conduct protons in the absence of water and, consequently, cannot function at temperatures >100 C. In addition, the stability of perfluorinated ionomers at temperatures >100 C is questionable. However, the performances of fuel cells of the power systems of which they are parts could be improved if operating temperatures could be raised above 140 C. What is needed to make this possible is a solid-electrolyte material, such as P4VPBS, that can be cast into membranes and that both retains proton conductivity and remains stable in the desired higher operating temperature range. A family of solid-electrolyte materials different from P4VPBS was described in Anhydrous Proton-Conducting Membranes for Fuel Cells (NPO-30493), NASA Tech Briefs, Vol. 29, No. 8 (August 2005), page 48. Those materials notably include polymeric quaternized amine salts. If molecules of such a polymeric salt could be endowed with flexible chain structures, it would be possible to overcome the deficiencies of simple organic amine salts that must melt before being able to conduct protons. However, no polymeric quaternized amine salts have yet shown to be useful in this respect. The present solid electrolyte is made by quaternizing the linear polymer poly- 4-vinylpyridine (P4VP) to obtain P4VPBS. It is important to start with P4VP having a molecular weight of 160,000 daltons because P4VPBS made from lower-molecular-weight P4VP yields brittle membranes. In an experimental synthesis, P4VP was dissolved in methanol and then reacted with an excess of sulfuric acid to precipitate P4VPBS. The precipitate was recovered, washed several times with methanol to remove traces of acid, and dried to a

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

    Science.gov (United States)

    Gyenge, E. L.

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-08-25

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

  9. High-throughput screening of ionic conductivity in polymer membranes

    International Nuclear Information System (INIS)

    Zapata, Pedro; Basak, Pratyay; Carson Meredith, J.

    2009-01-01

    Combinatorial and high-throughput techniques have been successfully used for efficient and rapid property screening in multiple fields. The use of these techniques can be an advantageous new approach to assay ionic conductivity and accelerate the development of novel materials in research areas such as fuel cells. A high-throughput ionic conductivity (HTC) apparatus is described and applied to screening candidate polymer electrolyte membranes for fuel cell applications. The device uses a miniature four-point probe for rapid, automated point-to-point AC electrochemical impedance measurements in both liquid and humid air environments. The conductivity of Nafion 112 HTC validation standards was within 1.8% of the manufacturer's specification. HTC screening of 40 novel Kynar poly(vinylidene fluoride) (PVDF)/acrylic polyelectrolyte (PE) membranes focused on varying the Kynar type (5x) and PE composition (8x) using reduced sample sizes. Two factors were found to be significant in determining the proton conducting capacity: (1) Kynar PVDF series: membranes containing a particular Kynar PVDF type exhibited statistically identical mean conductivity as other membranes containing different Kynar PVDF types that belong to the same series or family. (2) Maximum effective amount of polyelectrolyte: increments in polyelectrolyte content from 55 wt% to 60 wt% showed no statistically significant effect in increasing conductivity. In fact, some membranes experienced a reduction in conductivity.

  10. Helium Ion Microscopy of proton exchange membrane fuel cell electrode structures

    DEFF Research Database (Denmark)

    Chiriaev, Serguei; Dam Madsen, Nis; Rubahn, Horst-Günter

    2017-01-01

    electrode interface structure dependence on ionomer content, systematically studied by Helium Ion Microscopy (HIM). A special focus was on acquiring high resolution images of the electrode structure and avoiding interface damage from irradiation and tedious sample preparation. HIM demonstrated its....... In the hot-pressed electrodes, we found more closed contact between the electrode components, reduced particle size, polymer coalescence and formation of nano-sized polymer fiber architecture between the particles. Keywords: proton exchange membrane fuel cells (PEMFCs); Helium Ion Microscopy (HIM...

  11. Aprediction study for the behaviour of fuel cell membrane subjected to hygro and thermal stresses in running PEM fuel cell

    OpenAIRE

    Maher A.R. Sadiq Al-Baghdadi

    2016-01-01

    A three-dimensional, multi–phase, non-isothermal computational fluid dynamics model of a proton exchange membrane fuel cell has been used and developed to investigate the hygro and thermal stresses in polymer membrane, which developed during the cell operation due to the changes of temperature and relative humidity. The behaviour of the membrane during operation of a unit cell has been studied and investigated under real cell operating conditions. The results show that the non-uniform distrib...

  12. Nafion-based nanocomposite membranes for fuel cells

    CSIR Research Space (South Africa)

    Cele, NP

    2008-11-01

    Full Text Available . Zhang, J. Wang and F. Sheu, Journal of Electroanalytical Chemistry, 577 (2005) 295 J. James, T.Z. McMaster, J.M. Newton, M.J. Miles, Polymer 41 (2000) 4223 M. Ludvigsson, J. Lindgren, J. Tegenfeldt, Electrochim. Acta (2000) 2267 Shoibal Banerjee..., Dennis E. Curtin Journal of Fluorine Chemistry 125 (2004) 1211–1216 1. 2. 3. 4. 5. CPO-0023 By incorporating multi walled carbon nanotubes onto proton exchange membranes (PEM), its thermal stability is increased, making PEM fuel cells ideal...

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

    Science.gov (United States)

    Baker, Andrew M.

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

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

    DEFF Research Database (Denmark)

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

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Chulsung Bae

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Baradie, B

    1997-07-01

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

  18. Development of anionic membranes produced by radiation-grafting for alkaline fuel cell applications

    International Nuclear Information System (INIS)

    Pereira, Clotilde Coppini

    2017-01-01

    Anion Exchange Membranes (AEMs) are a promising alternative to the development of more efficient electrolytes for alkaline fuel cells. In general, the AEMs are ionomeric membranes able to conduct hydroxide ions (OH - ) due to the quaternary ammonium groups, which confer high pH equivalent to the AEM. In order to develop alkaline membranes with high chemical and thermal stability, besides satisfactory ionic conductivity for alkaline fuel cells, membranes based on low density polyethylene (LDPE), ultrahigh weight molecular weight polyethylene (UHWHPE), poly(ethylene-co-tetrafluoroethylene) (PETFE) and poly(hexafluoropropylene-co-tetrafluoroethylene) (PFEP) previously irradiated by using 60 Co gamma and electron beam sources, have been synthesized by styrene-grafting, and functionalized with trimethylamine to introduced quaternary ammonium groups. The resulting membranes were characterized by electron paramagnetic resonance (EPR), Raman spectroscopy, thermogravimetry (TG) and electrochemical impedance spectroscopy (EIS). The determination of the grafting degree and water uptake were conducted by gravimetry and ion exchange capacity, by titration. The membranes synthesized with PELD and PEUHMW polymers pre-irradiated at 70 kGy and stored at low temperature (-70 deg C), up to 10 months, showed ionic conductivity results, in hydroxide form (OH - ), of 29 mS.cm -1 and 14 mS.cm -1 at 65 deg C, respectively. The PFEP polymers irradiated by the simultaneous process showed insufficient grating levels for the membrane synthesis, requiring more studies to improve the irradiation and grafting process. The styrene-grafted PETFE membranes, pre-irradiated at 70 kGy and stored at low temperature (-70 deg C), up to 10 months, showed ionic conductivity results, in hydroxide form (OH - ), of 90 mS.cm -1 to 165 mS.cm -1 , in the temperature range 30 to 60 deg C. Such results have demonstrated that LDPE, UHMWPE and PETFE based AEMs are promising electrolytes for alkaline fuel cell

  19. Polymer Inclusion Membranes with Strip Dispersion

    Directory of Open Access Journals (Sweden)

    Yueh-Hsien Li

    2017-06-01

    Full Text Available The present work investigated the permeation of indium ions through a polymer inclusion membrane (PIM, prepared with cellulose triacetate (CTA as the base polymer, tris(2-butoxyethyl phosphate (TBEP as the plasticizer and di-(2-ethylhexylphosphoric acid (D2EHPA as the extractant. With 5 M HCl aqueous solution as the strip solution, we observed an initial indium permeability of 2.4 × 10−4 m/min. However, the permeability decreases with time, dropping to about 3.4 × 10−5 m/min after 200 min of operation. Evidence was obtained showing that hydrolysis of CTA occurred, causing a dramatic decrease in the feed pH (protons transported from strip to feed solutions and a loss of extractant and plasticizer from the membrane, and then leading to the loss of indium permeability. To alleviate the problem of hydrolysis, we proposed an operation scheme called polymer inclusion membranes with strip dispersion: dispersing the strip solution in extractant-containing oil and then bringing the dispersion to contact with the polymer membrane. Since the strong acid was dispersed in oil, the membrane did not directly contact the strong acid at all times, and membrane hydrolysis was thus alleviated and the loss of indium permeability was effectively prevented. With the proposed scheme, a stable indium permeability of 2.5 × 10−4 m/min was obtained during the whole time period of the permeation experiment.

  20. PBI/Nafion/SiO2 hybrid membrane for high-temperature low-humidity fuel cell applications

    International Nuclear Information System (INIS)

    Wang, Liang; Advani, Suresh G.; Prasad, Ajay K.

    2013-01-01

    A novel composite membrane for fuel cell applications was prepared by incorporating SiO 2 in PBI/Nafion resin by the sol–gel method. Polybenzimidazole (PBI) was blended with Nafion to improve the membrane stability. The presence of PBI also improves the dimensional stability of the composite membrane over a wide range of hydration conditions. Being highly hygroscopic, SiO 2 enhances water absorption and retention in the membrane which improves fuel cell performance under low relative humidity conditions. Scanning electron microscopy showed that the PBI and Nafion polymers can be blended uniformly. Energy dispersive X-ray spectroscopy confirmed the presence of SiO 2 in the composite membrane. Thermal gravimetric analysis confirmed the improved thermal stability of the SiO 2 /PBI/Nafion membrane. Tensile strength, water uptake and swelling of the composite membrane were also measured at 60 °C and compared with Nafion. The fuel cell performance of the novel SiO 2 /PBI/Nafion composite membrane at 120 °C and 35% relative humidity significantly improved over a pure Nafion membrane of the same thickness

  1. High temperature transport properties of polyphosphazene membranes for direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Xiangyang Zhou; Chalkova, E. [Pennsylvania State University (United States). The Energy Institute; Weston, J.; Lvov, S.N. [Pennsylvania State University (United States). The Energy Institute; Pennsylvania State University (United States). Department of Energy and Geo-Environment Engineering; Hofmann, M.A.; Ambler, C.M.; Allcock, H.R. [Pennsylvania State University (United States). Department of Chemistry

    2003-06-30

    Experimental methods for studying the conductivity and methanol permeability of proton conductive polymers over a wide range of temperatures have been developed. The proton conductivity and methanol permeability of several polymer electrolyte membranes including sulfonated and phosphonated poly[(aryloxy)phosphazenes] was determined at temperatures up to 120 {sup o}C. Nafion 117 membranes were tested using the same methods in order to determine the reliability of the methods. Although the conductivities of the polyphosphazene membranes were either similar to or lower than that of the Nafion 117 membranes, they continue to hold promise for fuel cell applications. We observed similar activation energies of proton conduction for Nafion 117, and for sulfonated and phosphonated polyphosphazene membranes. However, the methanol permeability of a sulfonated membrane was about 8 times lower than that of the Nafion 117 membrane at room temperature although the values were comparable at 120 {sup o}C. The permeability of a phosphonated phosphazene derivative was about 40 times lower than that of the Nafion 117 membrane at room temperature and about 9 times lower at 120 {sup o}C. This is a significant improvement over the behavior of Nafion 117. (author)

  2. High temperature transport properties of polyphosphazene membranes for direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Xiangyang; Weston, Jamie; Chalkova, Elena; Hofmann, Michael A.; Ambler, Catherine M.; Allcock, Harry R.; Lvov, Serguei N

    2003-06-30

    Experimental methods for studying the conductivity and methanol permeability of proton conductive polymers over a wide range of temperatures have been developed. The proton conductivity and methanol permeability of several polymer electrolyte membranes including sulfonated and phosphonated poly[(aryloxy)phosphazenes] was determined at temperatures up to 120 deg. C. Nafion 117 membranes were tested using the same methods in order to determine the reliability of the methods. Although the conductivities of the polyphosphazene membranes were either similar to or lower than that of the Nafion 117 membranes, they continue to hold promise for fuel cell applications. We observed similar activation energies of proton conduction for Nafion 117, and for sulfonated and phosphonated polyphosphazene membranes. However, the methanol permeability of a sulfonated membrane was about 8 times lower than that of the Nafion 117 membrane at room temperature although the values were comparable at 120 deg. C. The permeability of a phosphonated phosphazene derivative was about 40 times lower than that of the Nafion 117 membrane at room temperature and about 9 times lower at 120 deg. C. This is a significant improvement over the behavior of Nafion 117.

  3. High temperature transport properties of polyphosphazene membranes for direct methanol fuel cells

    International Nuclear Information System (INIS)

    Zhou Xiangyang; Weston, Jamie; Chalkova, Elena; Hofmann, Michael A.; Ambler, Catherine M.; Allcock, Harry R.; Lvov, Serguei N.

    2003-01-01

    Experimental methods for studying the conductivity and methanol permeability of proton conductive polymers over a wide range of temperatures have been developed. The proton conductivity and methanol permeability of several polymer electrolyte membranes including sulfonated and phosphonated poly[(aryloxy)phosphazenes] was determined at temperatures up to 120 deg. C. Nafion 117 membranes were tested using the same methods in order to determine the reliability of the methods. Although the conductivities of the polyphosphazene membranes were either similar to or lower than that of the Nafion 117 membranes, they continue to hold promise for fuel cell applications. We observed similar activation energies of proton conduction for Nafion 117, and for sulfonated and phosphonated polyphosphazene membranes. However, the methanol permeability of a sulfonated membrane was about 8 times lower than that of the Nafion 117 membrane at room temperature although the values were comparable at 120 deg. C. The permeability of a phosphonated phosphazene derivative was about 40 times lower than that of the Nafion 117 membrane at room temperature and about 9 times lower at 120 deg. C. This is a significant improvement over the behavior of Nafion 117

  4. Preparation and properties of hybrid direct methanol fuel cell membranes by embedding organophosphorylated titania submicrospheres into a chitosan polymer matrix

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hong [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072 (China); Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin University, Tianjin 300072 (China); Hou, Weiqiang; Wang, Jingtao; Xiao, Lulu; Jiang, Zhongyi [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072 (China)

    2010-07-01

    Organophosphorylated titania submicrospheres (OPTi) are prepared and incorporated into a chitosan (CS) matrix to fabricate hybrid membranes with enhanced methanol resistance and proton conductivity for application in direct methanol fuel cells (DMFC). The pristine monodispersed titania submicrospheres (TiO{sub 2}) of controllable particle size are synthesized through a modified sol-gel method and then phosphorylated by amino trimethylene phosphonic acid (ATMP) via chemical adsorption, which is confirmed by XPS, FTIR and TGA. The morphology and thermal property of the hybrid membranes are explored by SEM and TGA. The ionic cross-linking between the -PO{sub 3}H{sub 2} groups on OPTi and the -NH{sub 2} groups on CS lead to better compatibility between the inorganic fillers and the polymer matrix, as well as a decreased fractional free volume (FFV), which is verified by positron annihilation lifetime spectroscopy (PALS). The effects of particle size and content on the methanol permeability, proton conductivity, swelling and FFV of the membranes are investigated. Compared to pure CS membrane, the hybrid membranes exhibit an increased proton conductivity to an acceptable level of 0.01 S cm{sup -1} for DMFC application and a reduced methanol permeability of 5 x 10{sup -7} cm{sup 2} s{sup -1} at a 2 M methanol feed. (author)

  5. Preparation and properties of hybrid direct methanol fuel cell membranes by embedding organophosphorylated titania submicrospheres into a chitosan polymer matrix

    Science.gov (United States)

    Wu, Hong; Hou, Weiqiang; Wang, Jingtao; Xiao, Lulu; Jiang, Zhongyi

    Organophosphorylated titania submicrospheres (OPTi) are prepared and incorporated into a chitosan (CS) matrix to fabricate hybrid membranes with enhanced methanol resistance and proton conductivity for application in direct methanol fuel cells (DMFC). The pristine monodispersed titania submicrospheres (TiO 2) of controllable particle size are synthesized through a modified sol-gel method and then phosphorylated by amino trimethylene phosphonic acid (ATMP) via chemical adsorption, which is confirmed by XPS, FTIR and TGA. The morphology and thermal property of the hybrid membranes are explored by SEM and TGA. The ionic cross-linking between the -PO 3H 2 groups on OPTi and the -NH 2 groups on CS lead to better compatibility between the inorganic fillers and the polymer matrix, as well as a decreased fractional free volume (FFV), which is verified by positron annihilation lifetime spectroscopy (PALS). The effects of particle size and content on the methanol permeability, proton conductivity, swelling and FFV of the membranes are investigated. Compared to pure CS membrane, the hybrid membranes exhibit an increased proton conductivity to an acceptable level of 0.01 S cm -1 for DMFC application and a reduced methanol permeability of 5 × 10 -7 cm 2 s -1 at a 2 M methanol feed.

  6. Proton-Conducting Sulfonated and Phosphonated Polymers and Fuel Cell Membranes by Chemical Modification of Polysulfones

    OpenAIRE

    Lafitte, Benoit

    2007-01-01

    The proton exchange membrane fuel cell (PEMFC) is currently emerging as an efficient and environmentally friendly power source. The technology is very complex and relies ultimately on materials and components which need further development. One of the major hurdles for advancing the PEMFC technology is currently the demand for new durable low-cost polymeric membranes that will allow fuel cell operation at high temperatures without extensive humidification requirements. Thus, the design and pr...

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

    Science.gov (United States)

    Khalfan, Amish N.

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

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

    Science.gov (United States)

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

    2016-02-29

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

  9. Reformate tolerant electrocatalysts in solid polymer fuel cell membrane electrode assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, S J; Gunner, A G; Thompsett, D; Hards, G A

    1998-12-31

    The aim of the project was to evaluate a series of platinum group metal catalysts which had previously been identified from a wide range of areas related to carbon monoxide (CO) activation, and to demonstrate superior intrinsic reformate tolerance to current platinum/ruthenium technology as anode catalysts for Proton Exchange Membrane Fuel Cells (PEMFC). (author)

  10. Synthesis and characterization of sulfonated polymers for ionomeric membranes based on styrene copolymers; Sintese e caracterizacao de precursores sulfonados para membranas polimericas a base de copolimeros estirenicos

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.M.; Forte, M.M.C.; Amico, S.C. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Escola de Engenharia. Lab. de Materiais Polimericos (LAPOL)], e-mail: crismbecker@yahoo.com.br, e-mail: mmcforte@ufrgs.br, e-mail: amico@ufrgs.br; Vargas, J.V.C. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Engenharia Mecanica], e-mail: jvargas@demec.ufpr.br

    2006-07-01

    Polymer electrolyte membrane fuel cell (PEMFC) have emerged strongly as a viable alternative for power source owing to their high energy efficiency and environmental friendliness. Currently, Nafion is the most frequently used membrane even though it has a high cost. The objective of this work is to synthesize sulfonated polymers, based on styrene copolymers, with different sulfonation degrees as an alternative material for fuel cell membranes. Acetyl sulfate was used to carry out the sulfonation and the resulting polymers were characterized by Fourier Transform Infra-red (FTIR), thermogravimetric analysis (TGA) and degree of substitution or sulfonation (DS). The polyelectrolytes were evaluated regarding their ion exchange capacity (IEC) and conductivity. The results demonstrated that increasing the sulfonic acid content of the polymer results in higher IEC, conductivity and water uptake. (author)

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  12. Development of Less Water-Dependent Radiation Grafted Proton Exchange Membranes for Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Nasef, M M; Ahmad, A; Saidi, H; Dahlan, K Z.M. [Institute of Hydrogen Economy, Energy Research Alliance (ERA), International Campus, Univeristi Teknologi Malaysia, Jalan Semarak, Kuala Lumpur (Malaysia); Radiation Processing Division, Malaysian Nuclear Agency, Bangi, Kajang (Malaysia)

    2012-09-15

    The aim of these studies was the development of proton exchange membranes for polymer electrolyte membrane (PEM) fuel cell operated above 100{sup o}C, in order to obtain less water dependent, high quality and cheap electrolyte membrane. Sulfonic acid membranes were prepared by radiation induced grafting (RIG) of sodium styrene sulfonate (SSS) onto electron beam (EB) irradiated poly(vinylidene fluoride) (PVDF) films in a single step reaction for the first time using synergetic effect of acid addition to grafting mixture under various grafting conditions. The fuel cell related properties of the membranes were evaluated and the in situ performance was tested in a single H{sub 2}/O{sub 2} fuel cell under dynamic conditions and compared with a similar sulfonated polystyrene PVDF membrane obtained by two-step conventional RIG method i.e. grafting of styrene and subsequent sulfonation. The newly obtained membrane (degree of grafting, G% = 53) showed an improved performance and higher stability together with a cost reduction mainly as a result of elimination of sulfonation reaction. Acid-base composite membranes were also studied. EB pre-irradiated poly(ethylene-co-tetrafluoroethylene) (ETFE) films were grafted with N-vinyl pyridine (NVP). The effects of monomer concentration, dose, reaction time, film thickness, temperature and film storage time on G% were investigated. The membranes were subsequently doped with phosphoric acid under controlled condition. The proton conductivity of these membranes was investigated under low water conditions in correlation with the variation in G% and temperature (30-130{sup o}C). The performance of 34 and 49% grafted and doped membranes was tested in a single fuel cell at 130{sup o}C under dynamic conditions with 146 and 127 mW/cm{sup 2} power densities. The polarization, power density characteristics and the initial stability of the membrane showed a promising electrolyte candidate for fuel cell operation above 100 deg. C. (author)

  13. Steric Pressure among Membrane-Bound Polymers Opposes Lipid Phase Separation.

    Science.gov (United States)

    Imam, Zachary I; Kenyon, Laura E; Carrillo, Adelita; Espinoza, Isai; Nagib, Fatema; Stachowiak, Jeanne C

    2016-04-19

    Lipid rafts are thought to be key organizers of membrane-protein complexes in cells. Many proteins that interact with rafts have bulky polymeric components such as intrinsically disordered protein domains and polysaccharide chains. Therefore, understanding the interaction between membrane domains and membrane-bound polymers provides insights into the roles rafts play in cells. Multiple studies have demonstrated that high concentrations of membrane-bound polymeric domains create significant lateral steric pressure at membrane surfaces. Furthermore, our recent work has shown that lateral steric pressure at membrane surfaces opposes the assembly of membrane domains. Building on these findings, here we report that membrane-bound polymers are potent suppressors of membrane phase separation, which can destabilize lipid domains with substantially greater efficiency than globular domains such as membrane-bound proteins. Specifically, we created giant vesicles with a ternary lipid composition, which separated into coexisting liquid ordered and disordered phases. Lipids with saturated tails and poly(ethylene glycol) (PEG) chains conjugated to their head groups were included at increasing molar concentrations. When these lipids were sparse on the membrane surface they partitioned to the liquid ordered phase. However, as they became more concentrated, the fraction of GUVs that were phase-separated decreased dramatically, ultimately yielding a population of homogeneous membrane vesicles. Experiments and physical modeling using compositions of increasing PEG molecular weight and lipid miscibility phase transition temperature demonstrate that longer polymers are the most efficient suppressors of membrane phase separation when the energetic barrier to lipid mixing is low. In contrast, as the miscibility transition temperature increases, longer polymers are more readily driven out of domains by the increased steric pressure. Therefore, the concentration of shorter polymers required

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

    Science.gov (United States)

    Suresh, P V; Jayanti, Sreenivas

    2016-10-01

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

  15. 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.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    DEFF Research Database (Denmark)

    . 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...... or ionically cross-linking and structure modification With load, thermal or startup-shutdown cycling, the performance loss was found to be much bigger, about 300 µV per cycle or 40 µV per operating hour, due to the increased acid loss and catalyst support corrosion, particularly under open circuit voltage...... operation. Further efforts are outlined to the future work....

  19. Use of Novel Reinforced Cation Exchange Membranes for Microbial Fuel Cells

    International Nuclear Information System (INIS)

    Kamaraj, Sathish-Kumar; Romano, Sergio Mollá; Moreno, Vicente Compañ; Poggi-Varaldo, H.M.; Solorza-Feria, O.

    2015-01-01

    This work has been focused on the synthesis and characterization of different blended membranes SPEEK-35PVA (Water), SPEEK-35PVA (DMAc) prepared by casting and nanofiber-reinforced proton exchange membranes Nafion-PVA-15, Nafion-PVA-23 and SPEEK/PVA-PVB. The two first reinforced membranes were made up of Nafion® polymer deposited between polyvinyl alcohol (PVA) nanofibers. The last composite membrane is considered because the PVA is a hydrophilic polymer which forms homogeneous blends with SPEEK suitable to obtain high proton conductivity, while the hydrophobic PVB can produce blends in a phase separation morphology in which very low water uptake can be found. The synthesized membranes showed an outstanding stability, high proton conductivity, and enhanced mechanical and barrier properties. The membranes were characterized in single chamber microbial fuel cells (SCMFCs) using electrochemically enriched high sodic saline hybrid H-inocula (Geobacter metallireducen, Desulfurivibrio alkaliphilus, and Marinobacter adhaerens) as biocatalyst. The best performance was obtained with Nafion-PVA-15 membrane, which achieved a maximum power density of 1053 mW/m 3 at a cell voltage of 340 mV and displayed the lowest total internal resistance (Rint ≈ 522 Ω). This result is in agreement with the low oxygen permeability and the moderate conductivity found in this kind of membranes. These results are encouraging towards obtaining high concentrated sodic saline model wastewater exploiting MFCs

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-08-15

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  3. Spectrophotometric Analysis of Phosphoric Acid Leakage in High-Temperature Phosphoric Acid-Doped Polybenzimidazole Membrane Fuel Cell Application

    Directory of Open Access Journals (Sweden)

    Seungyoon Han

    2016-01-01

    Full Text Available High-temperature proton exchange membrane fuel cells (HT-PEMFCs utilize a phosphoric acid- (PA- doped polybenzimidazole (PBI membrane as a polymer electrolyte. The PA concentration in the membrane can affect fuel cell performance, as a significant amount of PA can leak from the membrane electrode assembly (MEA by dissolution in discharged water, which is a byproduct of cell operation. Spectrophotometric analysis of PA leakage in PA-doped polybenzimidazole membrane fuel cells is described here. This spectrophotometric analysis is based on measurement of absorption of an ion pair formed by phosphomolybdic anions and the cationoid color reagent. Different color reagents were tested based on PA detection sensitivity, stability of the formed color, and accuracy with respect to the amount of PA measured. This method allows for nondestructive analysis and monitoring of PA leakage during HT-PEMFCs operation.

  4. A polymer electrolyte fuel cell stack for stationary power generation from hydrogen fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gottesfeld, S. [Los Alamos National Lab., NM (United States)

    1995-09-01

    The fuel cell is the most efficient device for the conversion of hydrogen fuel to electric power. As such, the fuel cell represents a key element in efforts to demonstrate and implement hydrogen fuel utilization for electric power generation. The low temperature, polymer electrolyte membrane fuel cell (PEMFC) has recently been identified as an attractive option for stationary power generation, based on the relatively simple and benign materials employed, the zero-emission character of the device, and the expected high power density, high reliability and low cost. However, a PEMFC stack fueled by hydrogen with the combined properties of low cost, high performance and high reliability has not yet been demonstrated. Demonstration of such a stack will remove a significant barrier to implementation of this advanced technology for electric power generation from hydrogen. Work done in the past at LANL on the development of components and materials, particularly on advanced membrane/electrode assemblies (MEAs), has contributed significantly to the capability to demonstrate in the foreseeable future a PEMFC stack with the combined characteristics described above. A joint effort between LANL and an industrial stack manufacturer will result in the demonstration of such a fuel cell stack for stationary power generation. The stack could operate on hydrogen fuel derived from either natural gas or from renewable sources. The technical plan includes collaboration with a stack manufacturer (CRADA). It stresses the special requirements from a PEMFC in stationary power generation, particularly maximization of the energy conversion efficiency, extension of useful life to the 10 hours time scale and tolerance to impurities from the reforming of natural gas.

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

    International Nuclear Information System (INIS)

    Padmavathi, Rajangam; Karthikumar, Rajendhiran; Sangeetha, Dharmalingam

    2012-01-01

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

  6. Design of flow-field patterns for proton exchange membrane fuel cell application

    International Nuclear Information System (INIS)

    Rosli, M.I.; Wan Ramli Wan Daud; Kamaruzzaman Sopian; Jaafar Sahari

    2006-01-01

    Fuel cells are electrochemical devices that produce electricity at high efficiency without combustion. Fuel cells are emerging as viable candidates as power sources in many applications, including road vehicles, small-scale power stations, and possibly even portable electronics. This paper addresses the design of flow-field patterns for proton exchange membrane fuel cell (PEMFC). The PEMFC is a low-temperature fuel cell, in which a proton conductive polymer membrane is used as the electrolyte. In PEMFC, flow-field pattern is one important thing that effects the performance of PEMFC. This paper present three types of flow-field pattern that will be consider to be testing using CFD analysis and by experimental. The design look detail on to their shape and dimension to get the best pattern in term of more active electrode area compare to electrode area that will be used. Another advantage and disadvantage for these three type of flow-field patterns from literature also compared in this paper

  7. Evaluation of sulphonated polycarbonate membranes for fuel cells; Avaliacao de membranas de policarbonato sulfonado para celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Isabela M.M.; Gomes, Ana C.; Pessan, Luiz A. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Engenharia de Materiais], e-mail: isabelamuglia@gmail.com; Paranhos, Caio [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2011-07-01

    Fuel cells based on ion conducting polymer membranes offer an alternative for the conventional energetic matrices. Among many advantages of this system, we can mention the reduction on the emission of pollutants, high efficiency and simplicity. This work presents the modification of polycarbonate by sulfonation reaction using acetyl sulfate, in order to increase the conductor ionic character of the membranes used as electrolytes for hydrogen fuel cells. The sulfonated polycarbonate membranes were obtained by casting and then characterized by Fourier transform infrared spectroscopy, water vapor transmission, differential scanning calorimetry, thermogravimetric analysis and viscosimetry. (author)

  8. Imade-imide cross-linked PEEK proton exchange membrane.

    CSIR Research Space (South Africa)

    Luo, H

    2009-08-01

    Full Text Available The proton exchange membrane is a key component of polymer electrolyte membrane fuel cell (PEMFC). It plays an important role, conducts protons and separates the fuel from oxidant in PEMFC. DuPont’s Nafion is a perfluorinated sulfonic acid polymer...

  9. Mechanisms of proton conductance in polymer electrolyte membranes

    DEFF Research Database (Denmark)

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

    2001-01-01

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

  10. Numerical and experimental investigation on effects of inlet humidity and fuel flow rate and oxidant on the performance on polymer fuel cell

    International Nuclear Information System (INIS)

    Takalloo, Pourya Karimi; Nia, Ehsan Shabahang; Ghazikhani, Mohsen

    2016-01-01

    Highlights: • The impact of alteration in humidification on performance of fuel cell. • The impact of variation of temperature on performance of fuel cell. • The effects of using pure oxygen on the polarity curve are studied. • Fuel cell has been investigated both experimentally and numerically. - Abstract: Considering the importance of water management in a fuel cell and in order to increase the rate of the electro-chemical process in fuel cells with polymer membrane, it is required to optimize the humidity and inlet flow rates on anode and cathode sides. In this study, the impact of alteration in humidification and inlet flow rates on performance improvements for polymer membrane fuel cells is investigated both experimentally and numerically. To obtain the objective, employing the results from experiments and simulations, polarity curve and power density are produced and further used to conduct the desired investigations. In addition, through the conducted simulations the effects of using pure oxygen in the cathode side and inlet gas temperatures on the polarity curve is studied. The results demonstrate that an increase in humidity of the inlet gases will lead to performance amelioration in the cell, due to reduction in ionic resistance at the membrane. Furthermore, with the aforementioned increment; molar fractions of hydrogen and oxygen are decreased through the channel which results in produced water increment. Amplification in inlet flow rates to a certain level will improve the penetration possibility for gaseous forms leading to betterment of the cell performance in this specified range. Performance improvements with inlet gases temperature increment conclude other results of this study.

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

    Science.gov (United States)

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

    2016-01-01

    The regenerative H2/Br2-HBr fuel cell, utilizing an oxidant solution of Br2 in aqueous HBr, shows a number of benefits for grid-scale electricity storage. The membrane-electrode assembly, a key component of a fuel cell, contains a proton-conducting membrane, typically based on the perfluorosulfonic acid (PFSA) ionomer. Unfortunately, the high cost of PFSA membranes and their relatively high bromine crossover are serious drawbacks. Nanofiber composite membranes can overcome these limitations. In this work, composite membranes were prepared from electrospun dual-fiber mats containing Nafion® PFSA ionomer for facile proton transport and an uncharged polymer, polyphenylsulfone (PPSU), for mechanical reinforcement, and swelling control. After electrospinning, Nafion/PPSU mats were converted into composite membranes by softening the PPSU fibers, through exposure to chloroform vapor, thus filling the voids between ionomer nanofibers. It was demonstrated that the relative membrane selectivity, referenced to Nafion® 115, increased with increasing PPSU content, e.g., a selectivity of 11 at 25 vol% of Nafion fibers. H2-Br2 fuel cell power output with a 65 μm thick membrane containing 55 vol% Nafion fibers was somewhat better than that of a 150 μm Nafion® 115 reference, but its cost advantage due to a four-fold decrease in PFSA content and a lower bromine species crossover make it an attractive candidate for use in H2/Br2-HBr systems. PMID:28773268

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

    Directory of Open Access Journals (Sweden)

    Jun Woo Park

    2016-02-01

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

  13. Computational simulation of lithium ion transport through polymer nanocomposite membranes

    International Nuclear Information System (INIS)

    Moon, P.; Sandi, G.; Kizilel, R.; Stevens, D.

    2003-01-01

    We think of membranes as simple devices to facilitate filtration. In fact, membranes play a role in chemical, biological, and engineering processes such as catalysis, separation, and sensing by control of molecular transport and recognition. Critical factors that influence membrane discrimination properties include composition, pore size (as well as homogeneity), chemical functionalization, and electrical transport properties. There is increasing interest in using nanomaterials for the production of novel membranes due to the unique selectivity that can be achieved. Clay-polymer nanocomposites show particular promise due to their ease of manufacture (large sheets), their rigidity (self supporting), and their excellent mechanical properties. However, the process of lithium ion transport through the clay-polymer nanocomposite and mechanisms of pore size selection are poorly understood at the ionic and molecular level. In addition, manufacturing of clay-polymer nanocomposite membranes with desirable properties has proved challenging. We have built a general membrane-modeling tool (simulation system) to assist in developing improved membranes for selection, electromigration, and other electrochemical applications. Of particular interest are the recently formulated clay-polymer membranes. The transport mechanisms of the lithium ions membranes are not well understood and, therefore, they make an interesting test case for the model. In order to validate the model, we synthesized polymer nanocomposites membranes.

  14. Anion-conducting polymer, composition, and membrane

    Science.gov (United States)

    Pivovar, Bryan S [Los Alamos, NM; Thorn, David L [Los Alamos, NM

    2009-09-01

    Anion-conducing polymers and membranes with enhanced stability to aqueous alkali include a polymer backbone with attached sulfonium, phosphazenium, phosphazene, and guanidinium residues. Compositions also with enhanced stability to aqueous alkali include a support embedded with sulfonium, phosphazenium, and guanidinium salts.

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

    Science.gov (United States)

    Kahveci, E. E.; Taymaz, I.

    2018-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-15

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

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

    Science.gov (United States)

    Tadanaga, Kiyoharu

    2012-06-01

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

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  19. Ion pair reinforced semi-interpenetrating polymer network for direct methanol fuel cell applications.

    Science.gov (United States)

    Fang, Chunliu; Julius, David; Tay, Siok Wei; Hong, Liang; Lee, Jim Yang

    2012-06-07

    This paper describes the synthesis of ion-pair-reinforced semi-interpenetrating polymer networks (SIPNs) as proton exchange membranes (PEMs) for the direct methanol fuel cells (DMFCs). Specifically, sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO), a linear polymer proton source, was immobilized in a brominated PPO (BPPO) network covalently cross-linked by ethylenediamine (EDA). The immobilization of SPPO in the SIPN network was accomplished not only by the usual means of mechanical interlocking but also by ion pair formation between the sulfonic acid groups of SPPO and the amine moieties formed during the cross-linking reaction of BPPO with EDA. Through the ion pair interactions, the immobilization of SPPO polymer in the BPPO network was made more effective, resulting in a greater uniformity of sulfonic acid cluster distribution in the membrane. The hydrophilic amine-containing cross-links also compensated for some of the decrease in proton conductivity caused by ion pair formation. The SIPN membranes prepared as such showed good proton conductivity, low methanol permeability, good mechanical properties, and dimensional stability. Consequently, the PPO based SIPN membranes were able to deliver a higher maximum power density than Nafion, demonstrating the potential of the SIPN structure for PEM designs.

  20. Interaction of multiple biomimetic antimicrobial polymers with model bacterial membranes

    Energy Technology Data Exchange (ETDEWEB)

    Baul, Upayan, E-mail: upayanb@imsc.res.in; Vemparala, Satyavani, E-mail: vani@imsc.res.in [The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600113 (India); Kuroda, Kenichi, E-mail: kkuroda@umich.edu [Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan 48109 (United States)

    2014-08-28

    Using atomistic molecular dynamics simulations, interaction of multiple synthetic random copolymers based on methacrylates on prototypical bacterial membranes is investigated. The simulations show that the cationic polymers form a micellar aggregate in water phase and the aggregate, when interacting with the bacterial membrane, induces clustering of oppositely charged anionic lipid molecules to form clusters and enhances ordering of lipid chains. The model bacterial membrane, consequently, develops lateral inhomogeneity in membrane thickness profile compared to polymer-free system. The individual polymers in the aggregate are released into the bacterial membrane in a phased manner and the simulations suggest that the most probable location of the partitioned polymers is near the 1-palmitoyl-2-oleoyl-phosphatidylglycerol (POPG) clusters. The partitioned polymers preferentially adopt facially amphiphilic conformations at lipid-water interface, despite lacking intrinsic secondary structures such as α-helix or β-sheet found in naturally occurring antimicrobial peptides.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  3. In-situ radiation grafting of polymer films and degradation studies of monomers for applications in fuel cell membranes

    Energy Technology Data Exchange (ETDEWEB)

    Mitov, S.

    2007-02-15

    The present work consists of three parts which deal with the optimization of the properties of polymers finding application as proton exchange membranes in PEMFCs. The focus is the oxidative and photochemical stability of non-fluorinated polymer membranes, as well as the radiation-induced grafting of commercially available fluoropolymer films. The use of the ESR technique is common for the first two parts of the dissertation. ESR spectroscopy is the major method of study, because of its sensitivity and specificity for the detection of radical intermediates. It is a suitable spectroscopic technique to identify the nature of radiation generated radicals in organic polymers, and to monitor their concentration in-situ during the grafting process. The third part comprises the results and discussions of DFT calculations for non-fluorinated and fluorinated fragments.

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

    Science.gov (United States)

    Liu, Han; LaConti, Anthony B.

    2010-10-05

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

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

    Science.gov (United States)

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

    2011-01-11

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

  6. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Jie; Lee, Seung Jae [Energy Lab, Samsung Advanced Institute of Technology, Mt. 14-1 Nongseo-Dong, Giheung-Gu, Yongin-Si, Gyeonggi-Do 446-712 (Korea, Republic of)

    2006-11-22

    A three-dimensional, single-phase, non-isothermal numerical model for proton exchange membrane (PEM) fuel cell at high operating temperature (T>=393K) 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. (author)

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

    DEFF Research Database (Denmark)

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

    2001-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-07-01

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

  10. Quaternized poly(methyl methacrylate-co-butyl acrylate-co-vinylbenzyl chloride) membrane for alkaline fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Yanting; Guo, Juchen; Wang, Chunsheng [Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742 (United States); Chu, Deryn [Sensors and Electron Device Directorate, U.S. Army Research Laboratory, Adelphi, MD 20783 (United States)

    2010-06-15

    Instead of modification of pre-existing polymers, a new route of preparation of polyelectrolyte OH{sup -} conductive membranes via copolymerization of selected functional monomers was reported in this study. A random copolymer of poly(methyl methacrylate-co-butyl acrylate-co-vinylbenzyl chloride) was synthesized via copolymerization, which was followed by quaternization and membrane casting. The intrinsic OH{sup -} conductivity of the free-standing polyelectrolyte membranes can reach 8.2 x 10{sup -3} S cm{sup -1} at 80 C. The alkaline fuel cells using copolymer polyelectrolytes demonstrated the feasibility of the preparation concept of these membranes. (author)

  11. POROUS MEMBRANE TEMPLATED SYNTHESIS OF POLYMER PILLARED LAYER

    Institute of Scientific and Technical Information of China (English)

    Zhong-wei Niu; Dan Li; Zhen-zhong Yang

    2003-01-01

    The anodic porous alumina membranes with a definite pore diameter and aspect ratio were used as templates to synthesize polymer pillared layer structures. The pillared polymer was produced in the template membrane pores, and the layer on the template surfaces. Rigid cured epoxy resin, polystyrene and soft hydrogel were chosen to confirm the methodology. The pillars were in the form of either tubes or fibers, which were controlled by the alumina membrane pore surface wettability. The structural features were confirmed by scanning electron microscopy results.

  12. Pre-Stretched Low Equivalent Weight PFSA Membranes with Improved Fuel Cell Performance

    DEFF Research Database (Denmark)

    Zhang, Wenjing (Angela); Wycisk, Ryszard; Kish, Daniel L.

    2014-01-01

    for the morphological changes to be permanent. For 825 EW PFSA, stretching increased the polymer crystallinity by 22.5%, with a reduction in methanol permeability and a small increase in proton conductivity. In direct methanol fuel cell tests at 60◦C with 1.0 M methanol, the power density at 0.4 V with a DR = 4...... stretched 825 EW membrane (72 mW/cm2) was considerably greater than that obtained with a solution-cast membrane (28 mW/cm2) or with a commercial Nafion 117 membrane (55 mW/cm2). For 733 EW PFSA, stretching promoted the formation of ordered ionic domains leading to an increase in proton conductivity...

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

    Science.gov (United States)

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

    1988-01-01

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

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

    Science.gov (United States)

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

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

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

    Directory of Open Access Journals (Sweden)

    Nguyen Duy Vinh

    2016-10-01

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

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

    International Nuclear Information System (INIS)

    Kulikovsky, A.A.

    2004-01-01

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

  17. 3-Dimensional Computational Fluid Dynamics Modeling of Solid Oxide Fuel Cell Using Different Fuels

    Science.gov (United States)

    2011-01-01

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

  18. Layered plasma polymer composite membranes

    Science.gov (United States)

    Babcock, Walter C.

    1994-01-01

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

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

    Science.gov (United States)

    Chandran, Priji; Ghosh, Arpita; Ramaprabhu, Sundara

    2018-02-26

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

  20. Light Responsive Polymer Membranes: A Review

    Directory of Open Access Journals (Sweden)

    Fiore Pasquale Nicoletta

    2012-03-01

    Full Text Available In recent years, stimuli responsive materials have gained significant attention in membrane separation processes due to their ability to change specific properties in response to small external stimuli, such as light, pH, temperature, ionic strength, pressure, magnetic field, antigen, chemical composition, and so on. In this review, we briefly report recent progresses in light-driven materials and membranes. Photo-switching mechanisms, valved-membrane fabrication and light-driven properties are examined. Advances and perspectives of light responsive polymer membranes in biotechnology, chemistry and biology areas are discussed.

  1. Structure/property relationships in polymer membranes for water purification and energy applications

    Science.gov (United States)

    Geise, Geoffrey

    Providing sustainable supplies of purified water and energy is a critical global challenge for the future, and polymer membranes will play a key role in addressing these clear and pressing global needs for water and energy. Polymer membrane-based processes dominate the desalination market, and polymer membranes are crucial components in several rapidly developing power generation and storage applications that rely on membranes to control rates of water and/or ion transport. Much remains unknown about the influence of polymer structure on intrinsic water and ion transport properties, and these relationships must be developed to design next generation polymer membrane materials. For desalination applications, polymers with simultaneously high water permeability and low salt permeability are desirable in order to prepare selective membranes that can efficiently desalinate water, and a tradeoff relationship between water/salt selectivity and water permeability suggests that attempts to prepare such materials should rely on approaches that do more than simply vary polymer free volume. One strategy is to functionalize hydrocarbon polymers with fixed charge groups that can ionize upon exposure to water, and the presence of charged groups in the polymer influences transport properties. Additionally, in many emerging energy applications, charged polymers are exposed to ions that are very different from sodium and chloride. Specific ion effects have been observed in charged polymers, and these effects must be understood to prepare charged polymers that will enable emerging energy technologies. This presentation discusses research aimed at further understanding fundamental structure/property relationships that govern water and ion transport in charged polymer films considered for desalination and electric potential field-driven applications that can help address global needs for clean water and energy.

  2. Mass transport of direct methanol fuel cell species in sulfonated poly(ether ether ketone) membranes

    International Nuclear Information System (INIS)

    Silva, V.S.; Ruffmann, B.; Vetter, S.; Boaventura, M.; Mendes, A.M.; Madeira, L.M.; Nunes, S.P.

    2006-01-01

    Homogeneous membranes based on sulfonated poly(ether ether ketone) (sPEEK) with different sulfonation degrees (SD) were prepared and characterized. In order to perform a critical analysis of the SD effect on the polymer barrier and mass transport properties towards direct methanol fuel cell species, proton conductivity, water/methanol pervaporation and nitrogen/oxygen/carbon dioxide pressure rise method experiments are proposed. This procedure allows the evaluation of the individual permeability coefficients in hydrated sPEEK membranes with different sulfonation degrees. Nafion[reg] 112 was used as reference material. DMFC tests were also performed at 50 deg. C. It was observed that the proton conductivity and the permeability towards water, methanol, oxygen and carbon dioxide increase with the sPEEK sulfonation degree. In contrast, the SD seems to not affect the nitrogen permeability coefficient. In terms of selectivity, it was observed that the carbon dioxide/oxygen selectivity increases with the sPEEK SD. In contrast, the nitrogen/oxygen selectivity decreases. In terms of barrier properties for preventing the DMFC reactants loss, the polymer electrolyte membrane based on the sulfonated poly(ether ether ketone) with SD lower or equal to 71%, although having slightly lower proton conductivity, presented much better characteristics for fuel cell applications compared with the well known Nafion[reg] 112. In terms of the DMFC tests of the studied membranes at low temperature, the sPEEK membrane with SD = 71% showed to have similar performance, or even better, as that of Nafion[reg] 112. However, the highest DMFC overall efficiency was achieved using sPEEK membrane with SD = 52%

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

    Science.gov (United States)

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

    2018-03-01

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

  4. Fuel cell water transport

    Science.gov (United States)

    Vanderborgh, Nicholas E.; Hedstrom, James C.

    1990-01-01

    The moisture content and temperature of hydrogen and oxygen gases is regulated throughout traverse of the gases in a fuel cell incorporating a solid polymer membrane. At least one of the gases traverses a first flow field adjacent the solid polymer membrane, where chemical reactions occur to generate an electrical current. A second flow field is located sequential with the first flow field and incorporates a membrane for effective water transport. A control fluid is then circulated adjacent the second membrane on the face opposite the fuel cell gas wherein moisture is either transported from the control fluid to humidify a fuel gas, e.g., hydrogen, or to the control fluid to prevent excess water buildup in the oxidizer gas, e.g., oxygen. Evaporation of water into the control gas and the control gas temperature act to control the fuel cell gas temperatures throughout the traverse of the fuel cell by the gases.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-08-15

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

  6. Diffusion in inhomogeneous polymer membranes

    Science.gov (United States)

    Kasargod, Sameer S.; Adib, Farhad; Neogi, P.

    1995-10-01

    The dual mode sorption solubility isotherms assume, and in instances Zimm-Lundberg analysis of the solubilities show, that glassy polymers are heterogeneous and that the distribution of the solute in the polymer is also inhomogeneous. Under some conditions, the heterogeneities cannot be represented as holes. A mathematical model describing diffusion in inhomogeneous polymer membranes is presented using Cahn and Hilliard's gradient theory. The fractional mass uptake is found to be proportional to the fourth root of time rather than the square root, predicted by Fickian diffusion. This type of diffusion is classified as pseudo-Fickian. The model is compared with one experimental result available. A negative value of the persistence factor is obtained and the results are interpreted.

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  8. Synthesis, characterization and optimization of platinum-alloy nanoparticle catalysts in proton exchange membrane fuel cells

    Science.gov (United States)

    Srivastava, Ratndeep

    Renewable hydrogen-fuelled proton exchange membrane (PEMFC) fuel cells have consistently demonstrated great promise as a future source of energy due to their high conversion efficiency, lower temperature of operation and lack of greenhouse emissions. One of the major impediments in the commercialization of polymer electrolyte membrane fuel cells is the insufficient catalytic reactivity and higher cost of Pt electrocatalysts which are utilized for the electroreduction of oxygen from air. This dissertation focuses primarily on a family of Pt alloy fuel cell electrocatalysts referred to as de-alloyed core-shell electrocatalysts. These materials are bimetallic or multimetallic nanoparticles, mostly supported on conductive supports which were first described in a dissertation by Dr. S. Koh earlier in 2009.1 De-alloyed Pt nanoparticle electrocatalysts are formed from base metal rich binary Pt-M and ternary Pt-M1-M 2 (M, M1, M2 = Cu, Co, Ni, Fe and Cr) alloy nanoparticle precursors. The precursors are transformed and activated by electrochemical selective dissolution of the less noble metal component of the precursors (de-alloying). They have shown exceptional activity for oxygen reduction reaction (ORR) in idealized electrochemical half cell measurements, in particular rotating disk electrode experiments. However, these materials were never tested or implemented in realistic Membrane Electrode Assemblies (MEA) and single PEM fuel cells. The objective of this work was to implement de-alloyed Pt particle catalysts in realistic fuel cell electrode layers as well as a detailed characterization of their behavior and stability. The major challenges of MEA implementation consists of the behavior of the new nanostructured electrocatalysts inside the complex three-phase interface of polymer membrane ionomer, liquid water, metal catalyst, support, and reactant gas. Activity measurements were followed by medium and long-term durability analysis by potential cycling of the membrane

  9. Polymer and Membrane Design for Low Temperature Catalytic Reactions

    KAUST Repository

    Villalobos, Luis Francisco

    2016-02-29

    Catalytically active asymmetric membranes have been developed with high loadings of palladium nanoparticles located solely in the membrane\\'s ultrathin skin layer. The manufacturing of these membranes requires polymers with functional groups, which can form insoluble complexes with palladium ions. Three polymers have been synthesized for this purpose and a complexation/nonsolvent induced phase separation followed by a palladium reduction step is carried out to prepare such membranes. Parameters to optimize the skin layer thickness and porosity, the palladium loading in this layer, and the palladium nanoparticles size are determined. The catalytic activity of the membranes is verified with the reduction of a nitro-compound and with a liquid phase Suzuki-Miyaura coupling reaction. Very low reaction times are observed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  11. Modified hydrogenated PBLH copolymer synthesis with styrene for proton exchange membranes fuel cell application

    International Nuclear Information System (INIS)

    Ferraz, Fernando A.; Oliveira, Angelo R.S.; Rodrigues, Maraiza F.; Groetzner, Mariana B.; Cesar-Oliveira, Maria Aparecida F.; Cantao, Mauricio P.

    2005-01-01

    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)

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

    Directory of Open Access Journals (Sweden)

    Timothy D. Myles

    2015-10-01

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

  13. A Cation-containing Polymer Anion Exchange Membrane based on Poly(norbornene)

    Science.gov (United States)

    Beyer, Frederick; Price, Samuel; Ren, Xiaoming; Savage, Alice

    Cation-containing polymers are being studied widely for use as anion exchange membranes (AEMs) in alkaline fuel cells (AFCs) because AEMs offer a number of potential benefits including allowing a solid state device and elimination of the carbonate poisoning problem. The successful AEM will combine high performance from several orthogonal properties, having robust mechanical strength even when wet, high hydroxide conductivity, and the high chemical stability required for long device lifetimes. In this study, we have synthesized a model cationic polymer that combines three of the key advantages of Nafion. The polymer backbone based on semicrystalline atactic poly(norbornene) offers good mechanical properties. A flexible, ether-based tether between the backbone and fixed cation charged species (quaternary ammonium) should provide the low-Tg, hydrophilic environment required to facilitate OH- transport. Finally, methyl groups have been added at the beta position relative to the quaternary ammonium cation to prevent Hoffman elimination, one mechanism by which AEMs are neutralized in a high pH environment. In this poster, we will present our findings on mechanical properties, morphology, charge transport, and chemical stability of this material.

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

    Science.gov (United States)

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

    2017-09-01

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

  15. Carbon-supported co-pyridine as non-platinum cathode catalyst for alkaline membrane fuel cells

    International Nuclear Information System (INIS)

    Qiao, Jinli; Xu, Li; Liu, Yuyu; Xu, Pan; Shi, Jingjing; Liu, Shiyao; Tian, Binglun

    2013-01-01

    Development of high-performance cost-effective electrocatalyts that can replace Pt catalyst have been a central theme in polymer electrolyte membrane fuel cells (PEMFCs) including direct methanol fuel cells (DMFCs). Here we show that carbon-supported pyridine–cobalt nanoparticles (CoPy/C) can generate a high catalytic activity toward the oxygen reduction reaction (ORR). The catalysts are synthesized using cobalt sulfate heptahydrate (CoSO 4 ·7H 2 O) and pyridine (Py) as the Co and N precursors via a solid state reaction by heat-treatment in an inert atmosphere at 800 °C. In particular, the ORR kinetics on these catalyst materials are evaluated using rotating disk electrode (RDE) technique in electrolytes of various KOH concentrations, ranging from 0.05 to 12 M. The Koutecky–Levich equation analyses indicate that the transferred electron number, n, per oxygen molecule on CoPy/C electrode depend on the low negative ovevrpotentials in low KOH concentrations, whereas in high KOH concentrations the values of n for oxygen reduction depend on the high negative overpotentials, and varies between 3.5 and 4.0. These catalysts exhibit the superior methanol tolerance to commercial 40%Pt/C catalyst, and the negative effect of high KOH concentration is much less for CoPy/C than for Pt/C, suggesting the promising utilization of CoPy/C as electrocatalysts for alkaline polymer electrolyte membrane fuel cells

  16. A study for the research trends of membranes for proton exchange membrane fuel cells

    International Nuclear Information System (INIS)

    Sener, T.

    2004-01-01

    'Full text:' A single PEM fuel cell is comprised of a membrane electrode assembly, two bipolar plates and two fields. Membrane electrode assembly is the basic component of PEM fuel cell due to its cost and function, and it consists a membrane sandwiched between two electrocatalyst layers/electrodes and two gas diffusion layers. Increasing the PEM fuel cell operation temperature from 80 o C to 150-200 o C will prevent electrocatalysts CO poisoning and increase the fuel cell performance. Therefore, membranes must have chemical and mechanical resistance and must keep enough water at high temperatures. The aim of membrane studies through fuel cell commercialization is to produce a less expensive thin membrane with high operation temperature, chemical and mechanical resistance and water adsorption capacity. Within this frame, alternative membrane materials, membrane electrode assembly manufacture and evaluation methods are being studied. In this paper, recent studies are reviewed to give a conclusion for research trends. (author)

  17. PEM fuel cells for mobile applications. Project part: Membrane development. Final report; PEM-Brennstoffzellen fuer mobile Anwendungen. Teilprojekt: Membranentwicklung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Frank, G

    1999-01-20

    Polymer-Electrolyte-Membrane Fuel Cells (PEMFC) are attractive candidates for next century propulsion systems in passenger cars. The technical feasibility has been demonstrated by several car manufacturers. Today, PEMFC lack economical viability. One of the reasons is the cost of currently used materials, e.g. membranes. This project target towards the development of low cost, non-fluorinated membranes, which fulfil all technical requirements in PEMFC systems. In the frame of this project we were able to successfully develop new membranes based on polyaromatic polymers, which can be produced on a technical scale. These membranes enabled high power densities, exceeding 700 mW/cm{sup 2} at 80 C and their longevity has been demonstrated successfully up to 5,000 hours. Therefore, these membranes have sufficient electrochemical stability for the application in fuel cells. The prices in mass production for these new membranes can get significantly below prices of fluorinated membranes. (orig.) [Deutsch] Polymer-Elektrolyt-Membran-Brennstoffzellen (PEMFC) gelten als aussichtsreiche Kandidaten fuer alternative Fahrzeugantriebe fuer das naechste Jahrzehnt. Die technische Machbarkeit ist bereits mehrfach demonstriert worden. Allerdings sind die Kosten der PEMFC-Systeme noch zu hoch u.a. durch zu hohe Kosten der eingesetzten Materialien, so auch der Membranen. Ziel des Projektes war daher die Entwicklung kostenguenstiger, nichtfluorierter Membranen, die die technischen Anforderungen fuer die Anwendung in der PEM-Brennstoffzelle erfuellen. Im Projekt konnten erfolgreich Membranen auf Basis polyaromatischer Polymere entwickelt werden, die sich auch im technischen Massstab herstellen lassen. Die Membranen ermoeglichen hohe Leistungsdichten groesser 700 mW/cm{sup 2} bei Betriebstemperaturen von 80 C. Die Lebensdauer der Membranen wurde erfolgreich ueber 5.000 Stunden nachgewiesen. Die elektrochemische Stabilitaet der untersuchten Materialien ist damit gegeben. Die Preise dieser

  18. 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.

  19. Surface-Modified Membrane as A Separator for Lithium-Ion Polymer Battery

    Directory of Open Access Journals (Sweden)

    Jun Young Kim

    2010-04-01

    Full Text Available This paper describes the fabrication of novel modified polyethylene (PE membranes using plasma technology to create high-performance and cost-effective separator membranes for practical applications in lithium-ion polymer batteries. The modified PE membrane via plasma modification process plays a critical role in improving wettability and electrolyte retention, interfacial adhesion between separators and electrodes, and cycle performance of lithium-ion polymer batteries. This paper suggests that the performance of lithium-ion polymer batteries can be greatly enhanced by the plasma modification of commercial separators with proper functional materials for targeted application.

  20. High Molecular Weight Polybenzimidazole Membranes for High Temperature PEMFC

    DEFF Research Database (Denmark)

    Yang, Jingshuai; Cleemann, Lars Nilausen; Steenberg, T.

    2014-01-01

    High temperature operation of proton exchange membrane fuel cells under ambient pressure has been achieved by using phosphoric acid doped polybenzimidazole (PBI) membranes. To optimize the membrane and fuel cells, high performance polymers were synthesized of molecular weights from 30 to 94 kDa w...

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  2. Utilization of methanol for polymer electrolyte fuel cells in mobile systems

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, V M [Research Centre Juelich (KFA), Inst. of Energy Process Engineering (Germany); Broeckerhoff, P [Research Centre Juelich (KFA), Inst. of Energy Process Engineering (Germany); Hoehlein, B [Research Centre Juelich (KFA), Inst. of Energy Process Engineering (Germany); Menzer, R [Research Centre Juelich (KFA), Inst. of Energy Process Engineering (Germany); Stimming, U [Research Centre Juelich (KFA), Inst. of Energy Process Engineering (Germany)

    1994-04-01

    The constantly growing volume of road traffic requires the introduction of new vehicle propulsion systems with higher efficiency and drastically reduced emission rates. As part of the fuel cell programme of the Research Centre Juelich a vehicle propulsion system with methanol as secondary energy carrier and a polymer electrolyte membrane fuel cell (PEMFC) as the main component for energy conversion is developed. The fuel gas is produced by a heterogeneously catalyzed steam reforming reaction in which methanol is converted to H[sub 2], CO and CO[sub 2]. The required energy is provided by the catalytic conversion of methanol for both heating up the system and reforming methanol. The high CO content of the fuel gas requires further processing of the gas or the development of new electrocatalysts for the anode. Various Pt-Ru alloys show promising behaviour as CO-tolerant anodes. The entire fuel cell system is discussed in terms of energy and emission balances. The development of important components is described and experimental results are discussed. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-08-15

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

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

    Science.gov (United States)

    Gerteisen, Dietmar; Sadeler, Christian

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

  5. Polymer and Membrane Design for Low Temperature Catalytic Reactions

    KAUST Repository

    Villalobos, Luis Francisco; Xie, Yihui; Nunes, Suzana Pereira; Peinemann, Klaus-Viktor

    2016-01-01

    Catalytically active asymmetric membranes have been developed with high loadings of palladium nanoparticles located solely in the membrane's ultrathin skin layer. The manufacturing of these membranes requires polymers with functional groups, which can form insoluble complexes with palladium ions. Three polymers have been synthesized for this purpose and a complexation/nonsolvent induced phase separation followed by a palladium reduction step is carried out to prepare such membranes. Parameters to optimize the skin layer thickness and porosity, the palladium loading in this layer, and the palladium nanoparticles size are determined. The catalytic activity of the membranes is verified with the reduction of a nitro-compound and with a liquid phase Suzuki-Miyaura coupling reaction. Very low reaction times are observed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Styrene-Based Copolymer for Polymer Membrane Modifications

    OpenAIRE

    Harsha Srivastava; Harshad Lade; Diby Paul; G. Arthanareeswaran; Ji Hyang Kweon

    2016-01-01

    Poly(vinylidene fluoride) (PVDF) was modified with a styrene-based copolymer. The crystalline behavior, phase, thermal stability, and surface morphology of the modified membranes were analyzed. The membrane surface roughness showed a strong dependence on the styrene-acrylonitrile content and was reduced to 34% for a PVDF/styrene-acrylonitrile blend membrane with a 40/60 ratio. The thermal and crystalline behavior confirmed the blend miscibility of both polymers. It was observed in X-ray diffr...

  7. Polymeric molecular sieve membranes via in situ cross-linking of non-porous polymer membrane templates.

    Science.gov (United States)

    Qiao, Zhen-An; Chai, Song-Hai; Nelson, Kimberly; Bi, Zhonghe; Chen, Jihua; Mahurin, Shannon M; Zhu, Xiang; Dai, Sheng

    2014-04-16

    High-performance polymeric membranes for gas separation are attractive for molecular-level separations in industrial-scale chemical, energy and environmental processes. Molecular sieving materials are widely regarded as the next-generation membranes to simultaneously achieve high permeability and selectivity. However, most polymeric molecular sieve membranes are based on a few solution-processable polymers such as polymers of intrinsic microporosity. Here we report an in situ cross-linking strategy for the preparation of polymeric molecular sieve membranes with hierarchical and tailorable porosity. These membranes demonstrate exceptional performance as molecular sieves with high gas permeabilities and selectivities for smaller gas molecules, such as carbon dioxide and oxygen, over larger molecules such as nitrogen. Hence, these membranes have potential for large-scale gas separations of commercial and environmental relevance. Moreover, this strategy could provide a possible alternative to 'classical' methods for the preparation of porous membranes and, in some cases, the only viable synthetic route towards certain membranes.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-10-25

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

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

    International Nuclear Information System (INIS)

    Gao Kun; Hu Xinguo; Yi Tingfeng; Dai Changsong

    2006-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-10-25

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

  11. Plasma-modified polyethylene membrane as a separator for lithium-ion polymer battery

    International Nuclear Information System (INIS)

    Kim, Jun Young; Lee, Yongbeom; Lim, Dae Young

    2009-01-01

    The surface of polyethylene (PE) membranes as a separator for lithium-ion polymer battery was modified with acrylonitrile (AN) using the plasma technology. The plasma-induced acrylonitrile coated PE (PiAN-PE) membrane was characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and contact angle measurement. The electrochemical performance of the lithium-ion polymer cell fabricated with the PE and the PiAN-PE membranes were also analyzed. The surface characterization demonstrates that the enhanced adhesion of the PiAN-PE membrane resulted from the increased polar component of surface energy for the PiAN-PE membrane. The presence of the PiAN induced onto the surface of the membrane via the plasma modification plays a critical role in improving the wettability and electrolyte retention, the interfacial adhesion between the electrodes and the separator, the cycle performance of the resulting lithium-ion polymer cell assembly. The PiAN-PE membrane modified by the plasma treatment holds a great potential to be used as a high-performance and cost-effective separator for lithium-ion polymer battery.

  12. Selective transport of Fe(III) using ionic imprinted polymer (IIP) membrane particle

    Science.gov (United States)

    Djunaidi, Muhammad Cholid; Jumina, Siswanta, Dwi; Ulbricht, Mathias

    2015-12-01

    The membrane particles was prepared from polyvinyl alcohol (PVA) and polymer IIP with weight ratios of 1: 2 and 1: 1 using different adsorbent templates and casting thickness. The permeability of membrane towards Fe(III) and also mecanism of transport were studied. The selectivity of the membrane for Fe(III) was studied by performing adsorption experiments also with Cr(III) separately. In this study, the preparation of Ionic Imprinted Polymer (IIP) membrane particles for selective transport of Fe (III) had been done using polyeugenol as functional polymer. Polyeugenol was then imprinted with Fe (III) and then crosslinked with PEGDE under alkaline condition to produce polyeugenol-Fe-PEGDE polymer aggregates. The agrregates was then crushed and sieved using mesh size of 80 and the powder was then used to prepare the membrane particles by mixing it with PVA (Mr 125,000) solution in 1-Methyl-2-pyrrolidone (NMP) solvent. The membrane was obtained after casting at a speed of 25 m/s and soaking in NaOH solution overnight. The membrane sheet was then cut and Fe(III) was removed by acid to produce IIP membrane particles. Analysis of the membrane and its constituent was done by XRD, SEM and size selectivity test. Experimental results showed the transport of Fe(III) was faster with the decrease of membrane thickness, while the higher concentration of template ion correlates with higher Fe(III) being transported. However, the transport of Fe(III) was slower for higher concentration of PVA in the membrane. IImparticles works through retarded permeation mechanism, where Fe(III) was bind to the active side of IIP. The active side of IIP membrane was dominated by the -OH groups. The selectivity of all IIP membranes was confirmed as they were all unable to transport Cr (III), while NIP (Non-imprinted Polymer) membrane was able transport Cr (III).

  13. 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

  14. Comparison of different cells for resistance determination of freely standing polymer membranes developed for direct methanol fuel cell (DMFC) applications

    Czech Academy of Sciences Publication Activity Database

    Mohr, R.; Kůdela, Vlastimil; Schauer, Jan; Richau, K.

    2002-01-01

    Roč. 147, 1-3 (2002), s. 191-196 ISSN 0011-9164. [International Congress on Membranes and Membrane Processes. Toulouse, 07.07.2002-12.07.2002] R&D Projects: GA MŠk ME 366 Grant - others:GA-(DE) WTZ CZE 028/00 Institutional research plan: CEZ:AV0Z4050913 Keywords : conducting polymer membranes * impedance spectroscopy * sulfonated poly(phenylene oxide) Subject RIV: CG - Electrochemistry Impact factor: 0.517, year: 2002

  15. Electrochemical polymer electrolyte membranes

    CERN Document Server

    Fang, Jianhua; Wilkinson, David P

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Yang, Meijun; Zhang, Dongming

    2014-01-01

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

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

    Science.gov (United States)

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

    2017-06-01

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

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

    Science.gov (United States)

    Nogueira, Jéssica Alves; Varela, Hamilton

    2017-10-01

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

  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. Coupling Metallic Nanostructures to Thermally Responsive Polymers Allows the Development of Intelligent Responsive Membranes

    Directory of Open Access Journals (Sweden)

    J. Rubén Morones-Ramírez

    2014-01-01

    Full Text Available Development of porous membranes capable of controlling flow or changing their permeability to specific chemical entities, in response to small changes in environmental stimuli, is an area of appealing research, since these membranes present a wide variety of applications. The synthesis of these membranes has been mainly approached through grafting of environmentally responsive polymers to the surface walls of polymeric porous membranes. This synergizes the chemical stability and mechanical strength of the polymer membrane with the fast response times of the bonded polymer chains. Therefore, different composite membranes capable of changing their effective pore size with environmental triggers have been developed. A recent interest has been the development of porous membranes responsive to light, since these can achieve rapid, remote, noninvasive, and localized flow control. This work describes the synthesis pathway to construct intelligent optothermally responsive membranes. The method followed involved the grafting of optothermally responsive polymer-metal nanoparticle nanocomposites to polycarbonate track-etched porous membranes (PCTEPMs. The nanoparticles coupled to the polymer grafts serve as the optothermal energy converters to achieve optical switching of the pores. The results of the paper show that grafting of the polymer and in situ synthesis of the metallic particles can be easily achieved. In addition, the composite membranes allow fast and reversible switching of the pores using both light and heat permitting control of fluid flow.

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

    Science.gov (United States)

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

    2017-04-01

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

  3. Characterization of Hydrophobic Interactions of Polymers with Water and Phospholipid Membranes Using Molecular Dynamics Simulations

    Science.gov (United States)

    Drenscko, Mihaela

    Polymers and lipid membranes are both essential soft materials. The structure and hydrophobicity/hydrophilicity of polymers, as well as the solvent they are embedded in, ultimately determines their size and shape. Understating the variation of shape of the polymer as well as its interactions with model biological membranes can assist in understanding the biocompatibility of the polymer itself. Computer simulations, in particular molecular dynamics, can aid in characterization of the interaction of polymers with solvent, as well as polymers with model membranes. In this thesis, molecular dynamics serve to describe polymer interactions with a solvent (water) and with a lipid membrane. To begin with, we characterize the hydrophobic collapse of single polystyrene chains in water using molecular dynamics simulations. Specifically, we calculate the potential of mean force for the collapse of a single polystyrene chain in water using metadynamics, comparing the results between all atomistic with coarse-grained molecular simulation. We next explore the scaling behavior of the collapsed globular shape at the minimum energy configuration, characterized by the radius of gyration, as a function of chain length. The exponent is close to one third, consistent with that predicted for a polymer chain in bad solvent. We also explore the scaling behavior of the Solvent Accessible Surface Area (SASA) as a function of chain length, finding a similar exponent for both all-atomistic and coarse-grained simulations. Furthermore, calculation of the local water density as a function of chain length near the minimum energy configuration suggests that intermediate chain lengths are more likely to form dewetted states, as compared to shorter or longer chain lengths. Next, in order to investigate the molecular interactions between single hydrophobic polymer chains and lipids in biological membranes and at lipid membrane/solvent interface, we perform a series of molecular dynamics simulations of

  4. Compact hydrogen production systems for solid polymer fuel cells

    Science.gov (United States)

    Ledjeff-Hey, K.; Formanski, V.; Kalk, Th.; Roes, J.

    Generally there are several ways to produce hydrogen gas from carbonaceous fuels like natural gas, oil or alcohols. Most of these processes are designed for large-scale industrial production and are not suitable for a compact hydrogen production system (CHYPS) in the power range of 1 kW. In order to supply solid polymer fuel cells (SPFC) with hydrogen, a compact fuel processor is required for mobile applications. The produced hydrogen-rich gas has to have a low level of harmful impurities; in particular the carbon monoxide content has to be lower than 20 ppmv. Integrating the reaction step, the gas purification and the heat supply leads to small-scale hydrogen production systems. The steam reforming of methanol is feasible at copper catalysts in a low temperature range of 200-350°C. The combination of a small-scale methanol reformer and a metal membrane as purification step forms a compact system producing high-purity hydrogen. The generation of a SPFC hydrogen fuel gas can also be performed by thermal or catalytic cracking of liquid hydrocarbons such as propane. At a temperature of 900°C the decomposition of propane into carbon and hydrogen takes place. A fuel processor based on this simple concept produces a gas stream with a hydrogen content of more than 90 vol.% and without CO and CO2.

  5. Fabrication of all-polymer micro-DMFCs using UV-sensitive photoresist

    International Nuclear Information System (INIS)

    Cha, Hye-Yeon; Choi, Hoo-Gon; Nam, Jae-Do; Lee, Youngkwan; Cho, Sung Min; Lee, Eun-Sook; Lee, Jung-Kyu; Chung, Chan-Hwa

    2004-01-01

    We have developed the novel design and the fabrication processes for micro-direct methanol fuel cell (μ-DMFC). The membrane-electrode assemblies (MEA) consist of two identical polymer chips positioned on both sides of the proton exchange membrane, which play the roles of current collector, fuel-diffusion layer, and catalyst supporter. The detailed fabrication steps for the polymer chips are described. Each chip has 300 μm thru holes for catalyst supporter and 400 μm thru holes for fuel-diffusion layer. The total thickness of our all polymer μ-DMFC applying this MEA is about 500 μm including the thickness of Nafion (registered). The measured maximum power density of the all polymer micro-DMFC was 8 mW/cm 2 and current density was 37 mA/cm 2

  6. Improvement of interface property for membrane electrode assembly in fuel cell

    International Nuclear Information System (INIS)

    Fujii, K.; Sato, Y.; Kakigi, T.; Matsuura, A.; Mitani, N.; Muto, F.; Li Jingye; Miura, T.; Oshima, A.; Washio, M.

    2006-01-01

    Membrane electrode assembly (MEA) in polymer electrolyte fuel cells (PEFC) is consisted of proton exchange membrane (PEM), binder and Pt/C electrodes. In our previous work, partial-fluorinated sulfonic acid membranes were synthesized for PEMs using pre-EB grafting method. In the fuel cell (FC) operation, the dispersion of per-fluorinated sulfonic acid such as Nafion (DuPont de Nemours LTD.) was used for binder material. So, it is found that the trouble on conditions at three phase interface would occur at high temperature FC operation due to the differences of thermal properties. Thus, the control of interface property is important. In this study, in order to improve the interface properties, proton exchange membrane was synthesized from poly (tetrafluoroethylene-co-perfluoroalkylvinylether) (PFA), and then the obtained sulfonated PFA (s-PFA) was applied for binder material. PFA membranes were grafted in liquid styrene after EB irradiation under nitrogen atmosphere, and then sulfonated by chlorosulfonic acid solutions. The s-PFA membranes were milled to the powder in the mortar, and the average diameter was about 13 μm. S-PFA / Nafion blend dispersion was prepared by s-PFA mixed with Nafion dispersion with various ratios. MEAs were fabricated by using obtained binders, s-PFA membranes and Pt / C electrodes, followed by hot pressing at 110 degree C and at 8 MPa during 3 min. The properties of MEAs were measured by electrochemical analyses. In consequence, ion conductivities in MEA using obtained binders were about 1.3 times higher than those using Nafion dispersion. And, both power densities at 500 mA/cm 2 and maximum power densities were 1.1 times higher than those of Nafion dispersion. These are due to the improvement of the proton transfer at interface. (authors)

  7. Crosslinked polybenzimidazoles containing branching structure as membrane materials with excellent cell performance and durability for fuel cell applications

    Science.gov (United States)

    Hu, Meishao; Ni, Jiangpeng; Zhang, Boping; Neelakandan, Sivasubramaniyan; Wang, Lei

    2018-06-01

    Crosslinking is an effective method to improve the properties of high temperature proton exchange membranes based on polybenzimidazole. However, the compact structure of crosslinked polybenzimidazole hinders the phosphoric acid absorption of the membranes, resulting in a relatively poor fuel cell performance. Recently, we find that branched polymers can absorb more phosphoric acid with a larger free volume, but suffer from deteriorated mechanical strength. In this work, a new method is proposed to obtain excellent over-all properties of high temperature proton exchange membranes. A series of crosslinked polybenzimidazoles containing branching structure as membrane materials are successfully prepared for the first time. Compared with conventional crosslinked membranes, these crosslinked polybenzimidazole membranes containing branching structure exhibit a higher phosphoric acid doping level and proton conductivity, improved durability, lower swelling rate and comparable mechanical strength. In particular, the fuel cell base on the crosslinked and branched membrane with a 10% ratio of crosslinker in non-humidified hydrogen/air at 160 °C achieves a power density of 404 mW cm-2. The results indicate that the combination of crosslinking and branching is an effective approach to improve the properties of polybenzimidazole membrane materials.

  8. Analysis of coupled proton and water transport in a PEM fuel cell using the binary friction membrane model

    International Nuclear Information System (INIS)

    Carnes, B.; Djilali, N.

    2006-01-01

    Transport of liquid water within a polymer electrolyte membrane (PEM) is critical to the operation of a PEM fuel cell, due to the strong dependence of the membrane transport coefficients on water content. In addition, enhanced predictive abilities are particularly significant in the context of passive air breathing fuel cell designs where lower water contents will prevail in the membrane. We investigate and analyze the numerical predictions of a recently proposed rational model for transport of protons and water in a PEM, when compared to a widely used empirical model. While the performance is similar for a saturated membrane, for PEMs with low water content, the difference in computed current density and membrane water crossover can be substantial. The effects of coupling partially saturated gas diffusion electrodes (GDLs) with the membrane are studied in both a 1D and 2D context. In addition, a simplified 1D analytical membrane water transport model is validated against the complete 1D model predictions. Our numerical results predict a higher current density and more uniform membrane hydration using a dry cathode instead of a dry anode, and illustrate that the strongest 2D effects are for water vapor transport

  9. 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.

  10. Poly (ether ether ketone) membranes for fuel cells; Membranas de poli (eter eter cetona) sulfonado para celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Marrero, Jacqueline C.; Gomes, Ailton de S.; Filho, Jose C.D., E-mail: jacquecosta@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Hui, Wang S. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil); Oliveira, Vivianna S. de [Escola Tecnica Rezende-Rammel, Rio de Janeiro, RJ (Brazil)

    2015-07-01

    Polymeric membranes were developed using a SPEEK polymer matrix (sulphonated poly (ether ether ketone)), containing hygroscopic particles of zirconia (Zr) (incorporated by sol-gel method), for use as electrolyte membranes in fuel cells. SPEEK with different sulfonation degrees were used: 63 and 86%. The thermal analysis (TGA and DSC) was carried out to characterize the membranes and electrochemical impedance spectroscopy (EIS) was carried out to evaluating the proton conductivity of the membranes. Additional analysis were underway in order to characterize these membranes, which include: X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in order to evaluate the influence of zirconia and sulfonation degree on the properties of the membranes. (author)

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

    Science.gov (United States)

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

    2018-03-01

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

  12. Alkaline polymer electrolyte fuel cells stably working at 80 °C

    Science.gov (United States)

    Peng, Hanqing; Li, Qihao; Hu, Meixue; Xiao, Li; Lu, Juntao; Zhuang, Lin

    2018-06-01

    Alkaline polymer electrolyte fuel cells are a new class of polymer electrolyte fuel cells that fundamentally enables the use of nonprecious metal catalysts. The cell performance mostly relies on the quality of alkaline polymer electrolytes, including the ionic conductivity and the chemical/mechanical stability. For a long time, alkaline polymer electrolytes are thought to be too weak in stability to allow the fuel cell to be operated at elevated temperatures, e.g., above 60 °C. In the present work, we report a progress in the state-of-the-art alkaline polymer electrolyte fuel cell technology. By using a newly developed alkaline polymer electrolyte, quaternary ammonia poly (N-methyl-piperidine-co-p-terphenyl), which simultaneously possesses high ionic conductivity and excellent chemical/mechanical stability, the fuel cell can now be stably operated at 80 °C with high power density. The peak power density reaches ca. 1.5 W/cm2 at 80 °C with Pt/C catalysts used in both the anode and the cathode. The cell works stably in a period of study over 100 h.

  13. Robust and Elastic Polymer Membranes with Tunable Properties for Gas Separation.

    Science.gov (United States)

    Cao, Peng-Fei; Li, Bingrui; Hong, Tao; Xing, Kunyue; Voylov, Dmitry N; Cheng, Shiwang; Yin, Panchao; Kisliuk, Alexander; Mahurin, Shannon M; Sokolov, Alexei P; Saito, Tomonori

    2017-08-09

    Polymer membranes with the capability to process a massive volume of gas are especially attractive for practical applications of gas separation. Although much effort has been devoted to develop novel polymer membranes with increased selectivity, the overall gas-separation performance and lifetime of membrane are still negatively affected by the weak mechanical performance, low plasticization resistance and poor physical aging tolerance. Recently, elastic polymer membranes with tunable mechanical properties have been attracting significant attentions due to their tremendous potential applications. Herein, we report a series of urethane-rich PDMS-based polymer networks (U-PDMS-NW) with improved mechanical performance for gas separation. The cross-link density of U-PDMS-NWs is tailored by varying the molecular weight (M n ) of PDMS. The U-PDMS-NWs show up to 400% elongation and tunable Young's modulus (1.3-122.2 MPa), ultimate tensile strength (1.1-14.3 MPa), and toughness (0.7-24.9 MJ/m 3 ). All of the U-PDMS-NWs exhibit salient gas-separation performance with excellent thermal resistance and aging tolerance, high gas permeability (>100 Barrer), and tunable gas selectivity (up to α[P CO 2 /P N 2 ] ≈ 41 and α[P CO 2 /P CH 4 ] ≈ 16). With well-controlled mechanical properties and gas-separation performance, these U-PDMS-NW can be used as a polymer-membrane platform not only for gas separation but also for other applications such as microfluidic channels and stretchable electronic devices.

  14. Exploring Alkaline Stable Organic Cations for Polymer Hydroxide Exchange Membranes

    Science.gov (United States)

    2015-04-29

    1   1.1.2   Proton exchange membrane fuel cells ( PEMFCs ) ......................... 3   1.1.3   Alkaline fuel cells (AFCs...160   xi LIST OF FIGURES Figure 1.1:   Schematic diagram of a PEMFC ...according to the type of electrolyte they use. Nowadays, there are six major types of fuel cells: proton-exchange membrane fuel cells ( PEMFCs ), hydroxide

  15. Advances in Ceramic Supports for Polymer Electrolyte Fuel Cells

    Directory of Open Access Journals (Sweden)

    Oran Lori

    2015-08-01

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

  16. Block Copolymers for Alkaline Fuel Cell Membrane Materials

    Science.gov (United States)

    2014-07-30

    temperature fuel cells including proton exchange membrane fuel cell ( PEMFC ) and alkaline fuel cell (AFC) with operation temperature usually lower than 120...advantages over proton exchange membrane fuel cells ( PEMFCs ) resulting in the popularity of AFCs in the US space program.[8-11] The primary benefit AFC...offered over PEMFC is better electrochemical kinetics on the anode and cathode under the alkaline environment, which results in the ability to use

  17. Membranes for direct ethanol fuel cells: An overview

    International Nuclear Information System (INIS)

    Zakaria, Z.; Kamarudin, S.K.; Timmiati, S.N.

    2016-01-01

    Highlights: • DEFCs have emerged as alternative energy source. • But many issue need to be addressed. • This paper describes current problem and advancement of membrane in DEFC. - Abstract: Direct ethanol fuel cells (DEFCs) are attractive as a power source options because ethanol is a nontoxic, leading to ease of handling and a high energy density fuel, leading to high system energy density. However, to provide practical DEFCs power source there are several issues that still must be addressed including low power density, effect of ethanol crossover on efficiency of fuel utilization, electrical, mechanical and thermal stability and water uptake of the DEFCs electrolyte membrane. This paper describes the proton exchange membrane and alkaline exchange membrane for DEFCs, focusing on current problems and advancements in DEFC membranes. It also presents the specifications and performances of the membranes used in DEFC.

  18. Control-oriented model of a membrane humidifier for fuel cell applications

    International Nuclear Information System (INIS)

    Solsona, Miguel; Kunusch, Cristian; Ocampo-Martinez, Carlos

    2017-01-01

    Highlights: • A control-oriented model of a Nafion® membrane gas humidifier has been developed. • The control-oriented model has been experimentally validated. • A non-linear control strategy has been used to test its suitability for control purposes. - Abstract: Improving the humidification of polymer electrolyte membrane fuel-cells (PEMFC) is essential to optimize its performance and stability. Therefore, this paper presents an experimentally validated model of a low temperature PEMFC cathode humidifier for control/observation design purposes. A multi-input/multi-output non-linear fourth order model is derived, based on the mass and heat dynamics of circulating air. In order to validate the proposed model and methodology, experimental results are provided. Finally, a non-linear control strategy based on second order sliding mode is designed and analyzed in order to show suitability and usefulness of the approach.

  19. Nanoporous polymer--clay hybrid membranes for gas separation.

    Science.gov (United States)

    Defontaine, Guillaume; Barichard, Anne; Letaief, Sadok; Feng, Chaoyang; Matsuura, Takeshi; Detellier, Christian

    2010-03-15

    Nanohybrid organo-inorgano clay mineral-polydimethylsiloxane (PDMS) membranes were prepared by the reaction of pure and/or modified natural clay minerals (Sepiolite and montmorillonite) with PDMS in hexane, followed by evaporation of the solvent at 70 degrees C. The membranes were characterized by means of XRD, SEM, ATD-TG and solid state (29)Si magic angle spinning (MAS) and cross-polarization (CP) CP/MAS NMR. The morphology of the membranes depends on the content loading of clay mineral. For low content, the membrane composition is homogeneous, with well dispersed nanoparticles of clay into the polymer matrix, whereas for higher clay content, the membranes are constituted also of a mixture of well dispersed nanoparticles into the polymer, but in the presence of agglomerations of small clay particles. Quantitative (29)Si MAS NMR demonstrated a strong correlation between the clay content of the membrane and the average length of the PDMS chain, indicating that the nanohybrid material is made of clay particles covalently linked to the PDMS structure. This is particularly the case for Sepiolite with has a high density of Q(2) silanol sites. The separation performances of the prepared membranes were tested for CO(2)/CH(4) and O(2)/N(2) mixtures. The observed separation factors showed an increase of the selectivity in the case of CO(2)/CH(4) in comparison with membranes made from PDMS alone under the same conditions. 2009 Elsevier Inc. All rights reserved.

  20. 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.

  1. Grafting of molecularly imprinted polymer to porous polyethylene filtration membranes by plasma polymerization.

    Science.gov (United States)

    Cowieson, D; Piletska, E; Moczko, E; Piletsky, S

    2013-08-01

    An application of plasma-induced grafting of polyethylene membranes with a thin layer of molecularly imprinted polymer (MIP) was presented. High-density polyethylene (HDPE) membranes, "Vyon," were used as a substrate for plasma grafting modification. The herbicide atrazine, one of the most popular targets of the molecular imprinting, was chosen as a template. The parameters of the plasma treatment were optimized in order to achieve a good balance between polymerization and ablation processes. Modified HDPE membranes were characterized, and the presence of the grafted polymeric layer was confirmed based on the observed weight gain, pore size measurements, and infrared spectrometry. Since there was no significant change in the porosity of the modified membranes, it was assumed that only a thin layer of the polymer was introduced on the surface. The experiments on the re-binding of the template atrazine to the membranes modified with MIP and blank polymers were performed. HDPE membranes which were grafted with polymer using continuous plasma polymerization demonstrated the best result which was expressed in an imprinted factor equal to 3, suggesting that molecular imprinting was successfully achieved.

  2. Thermally rearranged (TR) bismaleimide-based network polymers for gas separation membranes.

    Science.gov (United States)

    Do, Yu Seong; Lee, Won Hee; Seong, Jong Geun; Kim, Ju Sung; Wang, Ho Hyun; Doherty, Cara M; Hill, Anita J; Lee, Young Moo

    2016-11-15

    Highly permeable, thermally rearranged polymer membranes based on bismaleimide derivatives that exhibit excellent CO 2 permeability up to 5440 Barrer with a high BET surface area (1130 m 2 g -1 ) are reported for the first time. In addition, the membranes can be easily used to form semi-interpenetrating networks with other polymers endowing them with superior gas transport properties.

  3. Novel proton conducting polymer electrolytes based on polyparabanic acid doped with H 3PO 4 for high temperature fuel cell

    Science.gov (United States)

    Aihara, Yuichi; Sonai, Atsuo

    Three novel proton conducting polymer electrolytes based on polyparabanic acid doped with H 3PO 4 were synthesized and their use in high temperature fuel cells characterized. The precursor polymers, PMD-Im, POD-Im and PDMDP-Im, were synthesized by cyclization polymerization of diisocynanates. After doping with H 3PO 4, the ionic conductivity and the thermal degradation were studied by using the AC impedance method and thermal gravimetric analysis, respectively. These membranes showed high ionic conductivity of the order of 10 -2 S cm -1 at 423 K with good thermal stability. Their application to fuel cells was demonstrated and polarization curves were obtained at 423 K were obtained without humidification.

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

    OpenAIRE

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

    2015-01-01

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

  5. The State of Water in Proton Conducting Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Allcock, Harry R.; Benesi, Alan; Macdonald, Digby D.

    2010-08-27

    The research carried out under grant No. DE-FG02-07ER46371, "The State of Water in Proton Conducting Membranes", during the period June 1, 2008 - May 31, 2010 was comprised of three related parts. These are: 1. An examination of the state of water in classical proton conduction membranes with the use of deuterium T1 NMR spectroscopy (Allcock and Benesi groups). 2. A dielectric relaxation examination of the behavior of water in classical ionomer membranes (Macdonald program). 3. Attempts to synthesize new proton-conduction polymers and membranes derived from the polyphosphazene system. (Allcock program) All three are closely related, crucial aspects of the design and development of new and improved polymer electrolyte fuel cell membranes on which the future of fuel cell technology for portable applications depends.

  6. Studies on as separation behaviour of polymer blending PI/PES hybrid mixed membrane: Effect of polymer concentration and zeolite loading

    Directory of Open Access Journals (Sweden)

    Ahmad Fauzi Ismail

    2014-04-01

    Full Text Available This study is performed primarily to investigate the effect of polymer concentration of polyimide/polyethersulfone (PI/PES blending on the gas separation performance of hybrid mixed matrix membrane. In this study, PI/ (PES–zeolite 4A mixed matrix membranes were casted using dry/wet phase inversion technique. The efefct of PI/PES concentrations and zeolite loading on the dope solution were investigated for gas separation performance. The results from the Field Emission Scanning Electron Microscopy (FESEM analysis confirmed that polymer concentration and zeolite loading was affected the morphology of membrane and gas separation performance. ‘Sieve-in-a-cage’ morphology observed the poor adhesion between polymer and zeolite at higher zeolite loading. The gas separation performance of the mixed matrix membranes were relatively higher compared to that of the neat polymeric membrane.

  7. Morphologies and separation characteristics of polyphenyl sulfone-based solvent resistant nanofiltration membranes: Effect of polymer concentration in casting solution and membrane pretreatment condition

    Energy Technology Data Exchange (ETDEWEB)

    Sani, Nur Aimie Abdullah; Lau, Woei Jye; Ismail, Ahmad Fauzi [Universiti Teknologi Malaysia, Skudai (Malaysia)

    2015-04-15

    The performance of polyphenylsulfone (PPSU) solvent resistant nanofiltration (SRNF)-based flat sheet membranes prepared from phase inversion method was investigated by varying the concentration of polymer in the dope solution and condition of membrane pretreatment process. The membrane properties were characterized by SEM, FTIR, AFM and contact angle goniometer, while their performance was evaluated by measuring methanol flux and rejection of different molecular weight of dyes (ranging from 269 to 1,470 g/mol) in methanol. The experimental results showed that the polymer concentration has great impact not only on the final membrane morphology but also its separation characteristics. Increasing polymer concentration from 17 to 25wt% tended to suppress finger-like structure and more pear-like pores were developed, causing methanol flux to decrease. This can be explained by the decrease in molecular weight cut off (MWCO) of the membrane prepared at high polymer concentration. With respect to the effect of membrane pretreatment conditions, the rejection of membrane was negatively affected with longer immersion period in methanol solution prior to filtration experiment. The variation in membrane rejection can be attributed to the rearrangement of the polymer chain, which results in membrane swelling and/or change of membrane surface hydrophilicity.

  8. Morphologies and separation characteristics of polyphenyl sulfone-based solvent resistant nanofiltration membranes: Effect of polymer concentration in casting solution and membrane pretreatment condition

    International Nuclear Information System (INIS)

    Sani, Nur Aimie Abdullah; Lau, Woei Jye; Ismail, Ahmad Fauzi

    2015-01-01

    The performance of polyphenylsulfone (PPSU) solvent resistant nanofiltration (SRNF)-based flat sheet membranes prepared from phase inversion method was investigated by varying the concentration of polymer in the dope solution and condition of membrane pretreatment process. The membrane properties were characterized by SEM, FTIR, AFM and contact angle goniometer, while their performance was evaluated by measuring methanol flux and rejection of different molecular weight of dyes (ranging from 269 to 1,470 g/mol) in methanol. The experimental results showed that the polymer concentration has great impact not only on the final membrane morphology but also its separation characteristics. Increasing polymer concentration from 17 to 25wt% tended to suppress finger-like structure and more pear-like pores were developed, causing methanol flux to decrease. This can be explained by the decrease in molecular weight cut off (MWCO) of the membrane prepared at high polymer concentration. With respect to the effect of membrane pretreatment conditions, the rejection of membrane was negatively affected with longer immersion period in methanol solution prior to filtration experiment. The variation in membrane rejection can be attributed to the rearrangement of the polymer chain, which results in membrane swelling and/or change of membrane surface hydrophilicity

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

    Science.gov (United States)

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

    2018-04-01

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

  10. Model-based diagnosis through Structural Analysis and Causal Computation for automotive Polymer Electrolyte Membrane Fuel Cell systems

    Science.gov (United States)

    Polverino, Pierpaolo; Frisk, Erik; Jung, Daniel; Krysander, Mattias; Pianese, Cesare

    2017-07-01

    The present paper proposes an advanced approach for Polymer Electrolyte Membrane Fuel Cell (PEMFC) systems fault detection and isolation through a model-based diagnostic algorithm. The considered algorithm is developed upon a lumped parameter model simulating a whole PEMFC system oriented towards automotive applications. This model is inspired by other models available in the literature, with further attention to stack thermal dynamics and water management. The developed model is analysed by means of Structural Analysis, to identify the correlations among involved physical variables, defined equations and a set of faults which may occur in the system (related to both auxiliary components malfunctions and stack degradation phenomena). Residual generators are designed by means of Causal Computation analysis and the maximum theoretical fault isolability, achievable with a minimal number of installed sensors, is investigated. The achieved results proved the capability of the algorithm to theoretically detect and isolate almost all faults with the only use of stack voltage and temperature sensors, with significant advantages from an industrial point of view. The effective fault isolability is proved through fault simulations at a specific fault magnitude with an advanced residual evaluation technique, to consider quantitative residual deviations from normal conditions and achieve univocal fault isolation.

  11. Novel Ceramic-Polymer Composite Membranes for the Separation of Hazardous Liquid Waste

    Energy Technology Data Exchange (ETDEWEB)

    Yoram Cohen

    2001-12-01

    The present project was conceived to address the need for robust yet selective membranes suitable for operating in harsh ph, solvent, and temperature environments. An important goal of the project was to develop a membrane chemical modification technology that would allow one to tailor-design membranes for targeted separation tasks. The method developed in the present study is based on the process of surface graft polymerization. Using essentially the same base technology of surface modification the research was aimed at demonstrating that improved membranes can be designed for both pervaporation separation and ultrafiltration. In the case of pervaporation, the present study was the first to demonstrate that pervaporation can be achieved with ceramic support membranes modified with an essentially molecular layer of terminally anchored polymer chains. The main advantage of the above approach, relative to other proposed membranes, is that the separating polymer layer is covalently attached to the ceramic support. Therefore, such membranes have a potential use in organic-organic separations where the polymer can swell significantly yet membrane robustness is maintained due to the chemical linkage of the chains to be inorganic support. The above membrane technology was also useful in developing fouling resistant ultrafiltration membranes. The prototype membrane developed in the project was evaluated for the treatment of oil-in-water microemulsions, demonstrating lack of irreversible fouling common with commercial membranes.

  12. Ultrathin self-assembled anionic polymer membranes for superfast size-selective separation

    Science.gov (United States)

    Deng, Chao; Zhang, Qiu Gen; Han, Guang Lu; Gong, Yi; Zhu, Ai Mei; Liu, Qing Lin

    2013-10-01

    Nanoporous membranes with superior separation performance have become more crucial with increasing concerns in functional nanomaterials. Here novel ultrahigh permeable nanoporous membranes have been fabricated on macroporous supports by self-assembly of anionic polymer on copper hydroxide nanostrand templates in organic solution. This facile approach has a great potential for the fabrication of ultrathin anionic polymer membranes as a general method. The as-fabricated self-assembled membranes have a mean pore size of 5-12 nm and an adjustable thickness as low as 85 nm. They allow superfast permeation of water, and exhibit excellent size-selective separation properties and good fouling resistance for negatively-charged solutes during filtration. The 85 nm thick membrane has an ultrahigh water flux (3306 l m-2 h-1 bar-1) that is an order of magnitude larger than commercial membranes, and can highly efficiently separate 5 and 15 nm gold nanoparticles from their mixtures. The newly developed nanoporous membranes have a wide application in separation and purification of biomacromolecules and nanoparticles.Nanoporous membranes with superior separation performance have become more crucial with increasing concerns in functional nanomaterials. Here novel ultrahigh permeable nanoporous membranes have been fabricated on macroporous supports by self-assembly of anionic polymer on copper hydroxide nanostrand templates in organic solution. This facile approach has a great potential for the fabrication of ultrathin anionic polymer membranes as a general method. The as-fabricated self-assembled membranes have a mean pore size of 5-12 nm and an adjustable thickness as low as 85 nm. They allow superfast permeation of water, and exhibit excellent size-selective separation properties and good fouling resistance for negatively-charged solutes during filtration. The 85 nm thick membrane has an ultrahigh water flux (3306 l m-2 h-1 bar-1) that is an order of magnitude larger than

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  15. Surface modification of polyacrylonitrile co-polymer membranes using pulsed direct current nitrogen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Dipankar; Neogi, Sudarsan; De, Sirshendu, E-mail: sde@che.iitkgp.ernet.in

    2015-12-31

    Low temperature plasma treatment using pulsed direct current discharge of nitrogen gas was employed to enhance hydrophilicity of the polyacrylonitrile co-polymer membranes. The membranes were characterized in terms of morphology, structure, hydrophilicity, and membrane performance. Properties and functional groups on the surface of polyacrylonitrile co-polymer membranes were investigated by contact angle, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Effects of plasma conditions, namely, pulsed voltage, duty cycle and treatment time on increase in membrane hydrophilicity were studied. Permeability of treated membrane was increased by 47% and it was retained up to 70 days. Surface etching due to plasma treatment was confirmed by weight loss of the treated membranes. Due to surface etching, average pore size increased and rejection of 200 kDa polyethylene glycol decreased to about 70% for the treated membrane. Oxygen and nitrogen functional groups were responsible for surface hydrophilicity. - Highlights: • Surface modification of polyacrylonitrile co-polymer membranes by pulsed direct current nitrogen plasma • Hydrophilic functional groups incorporated on the membrane surface • Significant enhancement of the permeability and wettability of the membranes • Water contact angle increased with storage time and finally stabilized.

  16. Surface modification of polyacrylonitrile co-polymer membranes using pulsed direct current nitrogen plasma

    International Nuclear Information System (INIS)

    Pal, Dipankar; Neogi, Sudarsan; De, Sirshendu

    2015-01-01

    Low temperature plasma treatment using pulsed direct current discharge of nitrogen gas was employed to enhance hydrophilicity of the polyacrylonitrile co-polymer membranes. The membranes were characterized in terms of morphology, structure, hydrophilicity, and membrane performance. Properties and functional groups on the surface of polyacrylonitrile co-polymer membranes were investigated by contact angle, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Effects of plasma conditions, namely, pulsed voltage, duty cycle and treatment time on increase in membrane hydrophilicity were studied. Permeability of treated membrane was increased by 47% and it was retained up to 70 days. Surface etching due to plasma treatment was confirmed by weight loss of the treated membranes. Due to surface etching, average pore size increased and rejection of 200 kDa polyethylene glycol decreased to about 70% for the treated membrane. Oxygen and nitrogen functional groups were responsible for surface hydrophilicity. - Highlights: • Surface modification of polyacrylonitrile co-polymer membranes by pulsed direct current nitrogen plasma • Hydrophilic functional groups incorporated on the membrane surface • Significant enhancement of the permeability and wettability of the membranes • Water contact angle increased with storage time and finally stabilized.

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

    International Nuclear Information System (INIS)

    Haryadi,; Sugianto, D.; Ristopan, E.

    2015-01-01

    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

  18. 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.

  19. 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.

  20. Trypsin immobilization in ordered porous polymer membranes for effective protein digestion

    International Nuclear Information System (INIS)

    Qiao, Juan; Kim, Jin Yong; Wang, Yuan Yuan; Qi, Li; Wang, Fu Yi; Moon, Myeong Hee

    2016-01-01

    Fast and effective protein digestion is a vital process for mass spectrometry (MS) based protein analysis. This study introduces a porous polymer membrane enzyme reactor (PPMER) coupled to nanoflow liquid chromatography-tandem MS (nLC-ESI-MS/MS) for on-line digestion and analysis of proteins. Poly (styrene-co-maleic anhydride) (PS-co-MAn) was fabricated by the breath figure method to make a porous polymer membrane in which the MAn group was covalently bound to enzyme. Based on this strategy, microscale PPMER (μPPMER) was constructed for on-line connection with the nLC-ESI-MS/MS system. Its capability for enzymatic digestion with bovine serum albumin (BSA) was evaluated with varied digestion periods. The on-line proteolysis of BSA and subsequent analysis with μPPMER-nLC-ESI-MS/MS revealed that peptide sequence coverage increased from 10.3% (digestion time 10 min) to 89.1% (digestion time 30 min). μPPMER can efficiently digest proteins due to the microscopic confinement effect, showing its potential application in fast protein identification and protease immobilization. Applications of on-line digestion using μPPMER with human plasma and urinary proteome samples showed that the developed on-line method yielded equivalent or better performance in protein coverage and identified more membrane proteins than the in-solution method. This may be due to easy accommodation of hydrophobic membrane proteins within membrane pores. - Highlights: • A porous polymer membrane enzyme reactor was developed. • Breath figure method was used for the fabrication of porous polymer membrane. • The enzyme reactor was coupled to nLC-ESI-MS/MS for proteins on-line digestion.

  1. Trypsin immobilization in ordered porous polymer membranes for effective protein digestion

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, Juan [Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, No. 2 Zhongguancun Beiyijie, Beijing 100190 (China); Kim, Jin Yong [Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seoul 120-749 (Korea, Republic of); Wang, Yuan Yuan [Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, No. 2 Zhongguancun Beiyijie, Beijing 100190 (China); Qi, Li, E-mail: qili@iccas.ac.cn [Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, No. 2 Zhongguancun Beiyijie, Beijing 100190 (China); Wang, Fu Yi [Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, No. 2 Zhongguancun Beiyijie, Beijing 100190 (China); Moon, Myeong Hee, E-mail: mhmoon@yonsei.ac.kr [Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seoul 120-749 (Korea, Republic of)

    2016-02-04

    Fast and effective protein digestion is a vital process for mass spectrometry (MS) based protein analysis. This study introduces a porous polymer membrane enzyme reactor (PPMER) coupled to nanoflow liquid chromatography-tandem MS (nLC-ESI-MS/MS) for on-line digestion and analysis of proteins. Poly (styrene-co-maleic anhydride) (PS-co-MAn) was fabricated by the breath figure method to make a porous polymer membrane in which the MAn group was covalently bound to enzyme. Based on this strategy, microscale PPMER (μPPMER) was constructed for on-line connection with the nLC-ESI-MS/MS system. Its capability for enzymatic digestion with bovine serum albumin (BSA) was evaluated with varied digestion periods. The on-line proteolysis of BSA and subsequent analysis with μPPMER-nLC-ESI-MS/MS revealed that peptide sequence coverage increased from 10.3% (digestion time 10 min) to 89.1% (digestion time 30 min). μPPMER can efficiently digest proteins due to the microscopic confinement effect, showing its potential application in fast protein identification and protease immobilization. Applications of on-line digestion using μPPMER with human plasma and urinary proteome samples showed that the developed on-line method yielded equivalent or better performance in protein coverage and identified more membrane proteins than the in-solution method. This may be due to easy accommodation of hydrophobic membrane proteins within membrane pores. - Highlights: • A porous polymer membrane enzyme reactor was developed. • Breath figure method was used for the fabrication of porous polymer membrane. • The enzyme reactor was coupled to nLC-ESI-MS/MS for proteins on-line digestion.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

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

    DEFF Research Database (Denmark)

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

    2018-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  5. Tröger’s Base Ladder Polymer for Membrane-Based Hydrocarbon Separation

    KAUST Repository

    Alhazmi, Abdulrahman

    2017-05-01

    The use of polymeric membranes for natural gas separation has rapidly increased during the past three decades, particularly for carbon dioxide separation from natural gas. Another valuable application is the separation of heavy hydrocarbons from methane (fuel gas conditioning), more importantly for remote area and off-shore applications. A new potential polymeric membrane that might be utilized for natural gas separations is a Tröger’s base ladder polymer (PIM-Trip-TB-2). This glassy polymeric membrane was synthesized by the polymerization reaction of 9, 10-dimethyl-2,6 (7) diaminotriptycene with dimethoxymethane. In this research, the polymer was selected due to its high surface area and highly interconnected microporous structure. Sorption isotherms of nitrogen (N2), oxygen (O¬2), methane (CH4), carbon dioxide (CO2), ethane (C2H6), propane (C3H8), and n-butane (n-C4H10) were measured at 35 °C over a range of pressures using a Hiden Intelligent Gravimetric Analyzer, IGA. The more condensable gases (C2H6, CO2, C3H8, and n-C4H10) showed high solubility due to their high affinity to the polymer matrix. The permeation coefficients were determined for various gases at 35 °C and pressure difference of 5 bar via the constant-pressure/variable-volume method. The PIM-Trip-TB-2 film exhibited high performance for several high-impact applications, such as O2/N2, H2/N2 and H2/CH4. Also, physical aging for several gases was examined by measuring the permeability coefficients at different periods of time. Moreover, a series of mixed-gas permeation tests was performed using 2 vol.% n-C4H10/98 vol.% CH4 and the results showed similar transport characteristics to other microporous polymers with pores of less than 2 nm. The work performed in this research suggested that PIM-Trip-TB-2 is suitable for the separation of: (i) higher hydrocarbons from methane and (ii) small, non-condensable gases such as O2/N2 and H2/CH4.

  6. High-pressure nuclear magnetic resonance studies of fuel cell membranes

    Science.gov (United States)

    Mananga, Eugene Stephane

    This thesis focuses on the use of high pressure NMR to study transport properties in electrolyte membranes used for fuel cells. The main concern is in studying the self-diffusion coefficients of ions and molecules in membranes and solutions, which can be used to characterize electrolytes in fuel cells. For this purpose, a high-pressure fringe field NMR method to study transport properties in material systems useful for fuel cell and battery electrolytes, was designed, developed, and implemented. In this investigation, pressure is the thermodynamic variable to obtain additional information about the ionic transport process, which could yield the crucial parameter, activation volume. Most of the work involves proton NMR, with additional investigations of others nuclei, such as fluorine, phosphorus and lithium. Using the FFG method, two fuel cell membrane types (NAFION-117, SPTES), and different dilutions of phosphoric acid were investigated, as was LiTf salt in Diglyme solution, which is used as a lithium battery electrolyte. In addition to high-pressure NMR diffusion measurements carried out in the fringe field gradient for the investigation of SPTES, pulse field gradient spin echo NMR was also used to characterize the water diffusion, in addition to measuring diffusion rates as a function of temperature. This second method allows us to measure distinct diffusion coefficients in cases where the different nuclear (proton) environments can be resolved in the NMR spectrum. Polymer electrolyte systems, in which the mobility of both cations and anions is probed by NMR self-diffusion measurements using standard pulsed field gradient methods and static gradient measurements as a function of applied hydrostatic pressure, were also investigated. The material investigated is the low molecular weight liquid diglyme/LiCF3SO3 (LiTf) complexes which can be used as electrolytes in lithium batteries. Finally, high-pressure diffusion coefficient measurements of phosphoric acid in

  7. Patents on Membranes Based on Non-Fluorinated Polymers for Vanadium Redox Flow Batteries.

    Science.gov (United States)

    Choi, So-Won; Kim, Tae-Ho; Cha, Sang-Ho

    2017-07-10

    Vanadium redox flow batteries (VRFBs) have received considerable attention as large-scale electrochemical energy storage systems. In particular, VRFBs offer a higher power and energy density than other RFBs and mitigate undesirable performance fading, such as inevitable ion crossover, because of the unique advantage that only the vanadium ion is employed as the active species in the two electrolytes. The key constituent of VRFBs is a separator to conduct protons and prevent cross-mixing of the positive and negative electrolytes. For this purpose, ion exchange membranes like sulfonated polymer membranes can be used. Although this type of membrane does not have ion exchange groups, it can achieve an ion exchange capacity by the formation of pores. This review highlights the patents on the preparation of non-fluorinated membranes (sulfonated aromatic polymer membranes and porous membranes) as alternatives to high-cost perfluorinated polymers and their VRFB performance. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. Commercialization of fuel-cells

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Scheiba, Frieder

    2009-01-28

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

  10. Polymers for hydrogen infrastructure and vehicle fuel systems :

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Rachel Reina; Simmons, Kevin L.; San Marchi, Christopher W.

    2013-10-01

    This document addresses polymer materials for use in hydrogen service. Section 1 summarizes the applications of polymers in hydrogen infrastructure and vehicle fuel systems and identifies polymers used in these applications. Section 2 reviews the properties of polymer materials exposed to hydrogen and/or high-pressure environments, using information obtained from published, peer-reviewed literature. The effect of high pressure on physical and mechanical properties of polymers is emphasized in this section along with a summary of hydrogen transport through polymers. Section 3 identifies areas in which fuller characterization is needed in order to assess material suitability for hydrogen service.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  12. Phosphoric acid distribution in the membrane electrode assembly of high temperature proton exchange membrane fuel cells

    International Nuclear Information System (INIS)

    Kwon, Kyungjung; Park, Jung Ock; Yoo, Duck Young; Yi, Jung S.

    2009-01-01

    The ionomer content in electrode is one of the most important parameters for the high performance of fuel cells. The high temperature PEMFC based on phosphoric acid (PA)-doped polymer membrane with unhumidified reactant gases has a difficulty in controlling the liquid state PA ionomer content in electrode. To evaluate the PA content in electrode, the three techniques of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and acid-base titration (ABT) are carried out in situ or ex situ. The properties of membrane electrode assembly (MEA) such as electrochemical surface area (ESA), ohmic resistance, charge transfer resistance, double layer capacitance and the amount of PA in MEA components (anode, cathode and membrane) are extracted by each technique. Ex situ CV with the usage of dry gases has a limitation in assessing the reliable ESA of unhumidified PEMFC. While in situ EIS presents some informative values of resistance and capacitance for understanding the PA distribution in MEA, its sensitivity to the PA content in MEA components needs to be higher for detecting a subtle change in PA distribution. Ex situ ABT supplies a clear PA distribution in MEA at room temperature but does not seem to reflect the operating state well at high temperatures. However, it can be used as a detection tool for the loss of the initial acid content in membrane during a long-term MEA durability study.

  13. Phosphoric acid distribution in the membrane electrode assembly of high temperature proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Kyungjung [Fuel Cell Group, Energy Lab, SAIT, Samsung Electronics Co., Ltd., San 14-1, Nongseo-dong, Giheung-gu, Yongin-si, Gyeonggi-do, 446-712 (Korea, Republic of)], E-mail: kfromberk@gmail.com; Park, Jung Ock; Yoo, Duck Young; Yi, Jung S. [Fuel Cell Group, Energy Lab, SAIT, Samsung Electronics Co., Ltd., San 14-1, Nongseo-dong, Giheung-gu, Yongin-si, Gyeonggi-do, 446-712 (Korea, Republic of)

    2009-11-01

    The ionomer content in electrode is one of the most important parameters for the high performance of fuel cells. The high temperature PEMFC based on phosphoric acid (PA)-doped polymer membrane with unhumidified reactant gases has a difficulty in controlling the liquid state PA ionomer content in electrode. To evaluate the PA content in electrode, the three techniques of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and acid-base titration (ABT) are carried out in situ or ex situ. The properties of membrane electrode assembly (MEA) such as electrochemical surface area (ESA), ohmic resistance, charge transfer resistance, double layer capacitance and the amount of PA in MEA components (anode, cathode and membrane) are extracted by each technique. Ex situ CV with the usage of dry gases has a limitation in assessing the reliable ESA of unhumidified PEMFC. While in situ EIS presents some informative values of resistance and capacitance for understanding the PA distribution in MEA, its sensitivity to the PA content in MEA components needs to be higher for detecting a subtle change in PA distribution. Ex situ ABT supplies a clear PA distribution in MEA at room temperature but does not seem to reflect the operating state well at high temperatures. However, it can be used as a detection tool for the loss of the initial acid content in membrane during a long-term MEA durability study.

  14. Multilayer affinity adsorption of albumin on polymer brushes modified membranes in a continuous-flow system.

    Science.gov (United States)

    Hu, Meng-Xin; Li, Xiang; Li, Ji-Nian; Huang, Jing-Jing; Ren, Ge-Rui

    2018-02-23

    Polymer brushes modified surfaces have been widely used for protein immobilization and isolation. Modification of membranes with polymer brushes increases the surface concentration of affinity ligands used for protein binding. Albumin is one of the transporting proteins and shows a high affinity to bile acids. In this work, the modified membranes with cholic acid-containing polymer brushes can be facilely prepared by the immobilization of cholic acid on the poly(2-hydroxyethyl methacrylate) grafted microporous polypropylene membranes (MPPMs) for affinity adsorption of albumin. ATR/FT-IR and X-ray photoelectron spectroscopy were used to characterize the chemical composition of the modified membranes. Water contact angle measurements were used to analyze the hydrophilic/hydrophobic properties of the membrane surface. The modified MPPMs show a high affinity to albumin and have little non-specific adsorption of hemoglobin. The dynamic binding capacity of albumin in the continous-flow system increases with the cycle number and feed rate as the binding degree of cholic acid is moderate. The highest binding capacity of affinity membranes is about 52.49 g/m 2 membrane, which is about 24 times more than the monolayer binding capacity. These results reveal proteins could be captured in multilayers by the polymer brushes containing affinity ligands similar to the polymer brushes containing ion-exchange groups, which open up the potential of the polymer brushes containing affinity ligands in protein or another components separation. And the cholic acid containing polymer brushes modified membranes has the promising potential for albumin separation and purification rapidly from serum or fermented solution in medical diagnosis and bioseparation. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. INVESTIGATION OF PEM FUEL CELL FOR AUTOMOTIVE USE

    Directory of Open Access Journals (Sweden)

    A. K. M. Mohiuddin

    2015-11-01

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

  16. Process to prepare stable trifluorostyrene containing compounds grafted to base polymers using a solvent/water mixture

    Science.gov (United States)

    Roelofs, Mark Gerrit; Yang, Zhen-Yu; Han, Amy Qi

    2010-06-15

    A fluorinated ion exchange polymer is prepared by grafting at least one grafting monomer derived from trifluorostyrene on to at least one base polymer in a organic solvent/water mixture. These ion exchange polymers are useful in preparing catalyst coated membranes and membrane electrode assemblies used in fuel cells.

  17. MEMS-Based Fuel Reformer with Suspended Membrane Structure

    Science.gov (United States)

    Chang, Kuei-Sung; Tanaka, Shuji; Esashi, Masayoshi

    We report a MEMS-based fuel reformer for supplying hydrogen to micro-fuel cells for portable applications. A combustor and a reforming chamber are fabricated at either side of a suspended membrane structure. This design is used to improve the overall thermal efficiency, which is a critical issue to realize a micro-fuel reformer. The suspended membrane structure design provided good thermal isolation. The micro-heaters consumed 0.97W to maintain the reaction zone of the MEMS-based fuel reformer at 200°C, but further power saving is necessary by improving design and fabrication. The conversion rate of methanol to hydrogen was about 19% at 180°C by using evaporated copper as a reforming catalyst. The catalytic combustion of hydrogen started without any assistance of micro-heaters. By feeding the fuel mixture of an equivalence ratio of 0.35, the temperature of the suspended membrane structure was maintained stable at 100°C with a combustion efficiency of 30%. In future works, we will test a micro-fuel reformer by using a micro-combustor to supply heat.

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

    Science.gov (United States)

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

    2011-10-01

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

  19. CO2 Selective, Zeolitic Imidazolate Framework-7 Based Polymer Composite Mixed-Matrix Membranes

    KAUST Repository

    Chakrabarty, Tina; Neelakanda, Pradeep; Peinemann, Klaus-Viktor

    2018-01-01

    CO2 removal is necessary to mitigate the effects of global warming but it is a challenging process to separate CO2 from natural gas, biogas, and other gas streams. Development of hybrid membranes by use of polymers and metal-organic framework (MOF) particles is a viable option to overcome this challenge. A ZIF-7 nano-filler that was synthesized in our lab was embedded into a designed polymer matrix at various loadings and the performance of the mixed matrix membranes was evaluated in terms of gas permeance and selectivity. Hybrid membranes with various loadings (20, 30 and 40 wt%) were developed and tested at room temperature by a custom made time lag equipment and a jump in selectivity was observed when compared with the pristine polymer. A commercially attractive region for the selectivity CO2 over CH4 was achieved with a selectivity of 39 for 40 wt% particle loading. An increase in selectivity was observed with the increase of ZIF-7 loadings. Best performance was seen at 40% ZIF-7 loaded membrane with an ideal selectivity of 39 for CO2 over CH4. The obtained selectivity was 105% higher for CO2 over CH4 than the selectivity of the pristine polymer with a slight decrease in permeance. Morphological characterization of such developed membranes showed an excellent compatibility between the polymer and particle adhesion.

  20. CO2 Selective, Zeolitic Imidazolate Framework-7 Based Polymer Composite Mixed-Matrix Membranes

    KAUST Repository

    Chakrabarty, Tina

    2018-05-17

    CO2 removal is necessary to mitigate the effects of global warming but it is a challenging process to separate CO2 from natural gas, biogas, and other gas streams. Development of hybrid membranes by use of polymers and metal-organic framework (MOF) particles is a viable option to overcome this challenge. A ZIF-7 nano-filler that was synthesized in our lab was embedded into a designed polymer matrix at various loadings and the performance of the mixed matrix membranes was evaluated in terms of gas permeance and selectivity. Hybrid membranes with various loadings (20, 30 and 40 wt%) were developed and tested at room temperature by a custom made time lag equipment and a jump in selectivity was observed when compared with the pristine polymer. A commercially attractive region for the selectivity CO2 over CH4 was achieved with a selectivity of 39 for 40 wt% particle loading. An increase in selectivity was observed with the increase of ZIF-7 loadings. Best performance was seen at 40% ZIF-7 loaded membrane with an ideal selectivity of 39 for CO2 over CH4. The obtained selectivity was 105% higher for CO2 over CH4 than the selectivity of the pristine polymer with a slight decrease in permeance. Morphological characterization of such developed membranes showed an excellent compatibility between the polymer and particle adhesion.

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

    International Nuclear Information System (INIS)

    Hasegawa, Shin; Suzuki, Yasuyuki; Maekawa, Yasunari

    2008-01-01

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

  2. Catalytic molecularly imprinted polymer membranes: development of the biomimetic sensor for phenols detection.

    Science.gov (United States)

    Sergeyeva, T A; Slinchenko, O A; Gorbach, L A; Matyushov, V F; Brovko, O O; Piletsky, S A; Sergeeva, L M; Elska, G V

    2010-02-05

    Portable biomimetic sensor devices for the express control of phenols content in water were developed. The synthetic binding sites mimicking active site of the enzyme tyrosinase were formed in the structure of free-standing molecularly imprinted polymer membranes. Molecularly imprinted polymer membranes with the catalytic activity were obtained by co-polymerization of the complex Cu(II)-catechol-urocanic acid ethyl ester with (tri)ethyleneglycoldimethacrylate, and oligourethaneacrylate. Addition of the elastic component oligourethaneacrylate provided formation of the highly cross-linked polymer with the catalytic activity in a form of thin, flexible, and mechanically stable membrane. High accessibility of the artificial catalytic sites for the interaction with the analyzed phenol molecules was achieved due to addition of linear polymer (polyethyleneglycol Mw 20,000) to the initial monomer mixture before the polymerization. As a result, typical semi-interpenetrating polymer networks (semi-IPNs) were formed. The cross-linked component of the semi-IPN was represented by the highly cross-linked catalytic molecularly imprinted polymer, while the linear one was represented by polyethyleneglycol Mw 20,000. Extraction of the linear polymer from the fully formed semi-IPN resulted in formation of large pores in the membranes' structure. Concentration of phenols in the analyzed samples was detected using universal portable device oxymeter with the oxygen electrode in a close contact with the catalytic molecularly imprinted polymer membrane as a transducer. The detection limit of phenols detection using the developed sensor system based on polymers-biomimics with the optimized composition comprised 0.063 mM, while the linear range of the sensor comprised 0.063-1 mM. The working characteristics of the portable sensor devices were investigated. Storage stability of sensor systems at room temperature comprised 12 months (87%). As compared to traditional methods of phenols

  3. Improving Hemocompatibility of Membranes for Extracorporeal Membrane Oxygenators by Grafting Nonthrombogenic Polymer Brushes.

    Science.gov (United States)

    Obstals, Fabian; Vorobii, Mariia; Riedel, Tomáš; de Los Santos Pereira, Andres; Bruns, Michael; Singh, Smriti; Rodriguez-Emmenegger, Cesar

    2018-03-01

    Nonthrombogenic modifications of membranes for extracorporeal membrane oxygenators (ECMOs) are of key interest. The absence of hemocompatibility of these membranes and the need of anticoagulation of patients result in severe and potentially life-threatening complications during ECMO treatment. To address the lack of hemocompatibility of the membrane, surface modifications are developed, which act as barriers to protein adsorption on the membrane and, in this way, prevent activation of the coagulation cascade. The modifications are based on nonionic and zwitterionic polymer brushes grafted directly from poly(4-methyl-1-pentene) (TPX) membranes via single electron transfer-living radical polymerization. Notably, this work introduces the first example of well-controlled surface-initiated radical polymerization of zwitterionic brushes. The antifouling layers markedly increase the recalcification time (a proxy of initiation of coagulation) compared to bare TPX membranes. Furthermore, platelet and leukocyte adhesion is drastically decreased, rendering the ECMO membranes hemocompatible. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. A novel anion exchange membrane from polystyrene (ethylene butylene) polystyrene: Synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Vinodh, Rajangam; Ilakkiya, Arjunan; Elamathi, Swaminathan [Department of Chemistry, Anna University Chennai, Sardar Patel Road, Chennai 600025, Tamil Nadu (India); Sangeetha, Dharmalingam, E-mail: sangeetha@annauniv.ed [Department of Chemistry, Anna University Chennai, Sardar Patel Road, Chennai 600025, Tamil Nadu (India)

    2010-02-25

    We look forward for an eco-friendly hydrocarbon polymer with higher molecular weight for the preparation of an anion exchange membrane. Polystyrene ethylene butylene polystyrene (PSEBS) was chosen as the polymer matrix. The anion exchange membrane was prepared from PSEBS tri-block co-polymer and then the properties were characterized for alkaline fuel cell application. The preparation of anion exchange polymer involved two steps namely chloromethylation and quaternization. The anion exchange membrane with high conductivity has been prepared by introducing quaternary ammonium groups in to the polymer. Finally, the membrane was prepared using solution casting method. The solution casting method yields highly hydrophilic membranes with uniform structure that were suitable for electrochemical applications. The efficiency of the entrapment was monitored by swelling ratio, chemical stability and ion exchange measurement. The characteristic structural properties of the membrane were investigated by FT-IR spectroscopy and {sup 1}H NMR spectroscopy. The thermal stability of the membrane was characterized by TGA, DSC and DMA (dynamic mechanical analysis). The prepared uniform electrolyte membrane in this study has high thermal and chemical stability. The surface morphology and elemental composition of the quaternized PSEBS was determined by SEM-EDXA techniques, respectively. The measured hydroxyl ion conductivity of the synthesized alkaline PSEBS polymer electrolyte membrane showed ionic conductivity in the range of 10{sup -3} S/cm in deionized water at room temperature. It was found that the substitution provided a flexible, chemically and thermally stable membrane. Hence, the membrane will have potential application in the alkaline fuel cell.

  5. A novel anion exchange membrane from polystyrene (ethylene butylene) polystyrene: Synthesis and characterization

    International Nuclear Information System (INIS)

    Vinodh, Rajangam; Ilakkiya, Arjunan; Elamathi, Swaminathan; Sangeetha, Dharmalingam

    2010-01-01

    We look forward for an eco-friendly hydrocarbon polymer with higher molecular weight for the preparation of an anion exchange membrane. Polystyrene ethylene butylene polystyrene (PSEBS) was chosen as the polymer matrix. The anion exchange membrane was prepared from PSEBS tri-block co-polymer and then the properties were characterized for alkaline fuel cell application. The preparation of anion exchange polymer involved two steps namely chloromethylation and quaternization. The anion exchange membrane with high conductivity has been prepared by introducing quaternary ammonium groups in to the polymer. Finally, the membrane was prepared using solution casting method. The solution casting method yields highly hydrophilic membranes with uniform structure that were suitable for electrochemical applications. The efficiency of the entrapment was monitored by swelling ratio, chemical stability and ion exchange measurement. The characteristic structural properties of the membrane were investigated by FT-IR spectroscopy and 1 H NMR spectroscopy. The thermal stability of the membrane was characterized by TGA, DSC and DMA (dynamic mechanical analysis). The prepared uniform electrolyte membrane in this study has high thermal and chemical stability. The surface morphology and elemental composition of the quaternized PSEBS was determined by SEM-EDXA techniques, respectively. The measured hydroxyl ion conductivity of the synthesized alkaline PSEBS polymer electrolyte membrane showed ionic conductivity in the range of 10 -3 S/cm in deionized water at room temperature. It was found that the substitution provided a flexible, chemically and thermally stable membrane. Hence, the membrane will have potential application in the alkaline fuel cell.

  6. Carbon nanotubes rooted montmorillonite (CNT-MM) reinforced nanocomposite membrane for PEM fuel cells

    International Nuclear Information System (INIS)

    Manikandan, Dhanagopal; Mangalaraja, Ramalinga Viswanathan; Avila, Ricardo E.; Siddheswaran, Rajendran; Ananthakumar, Solaiappan

    2012-01-01

    Highlights: ► Novel montmorillonite-CNT (MM-CNT) nanohybrid materials were produced by CVD. ► Highly selective crystalline carbon nanotubes were grown over montmorillonite. ► Fabricated Nafion-MM-CNT nanocomposite membrane by solution casting method. ► Homogeneous dispersion of MM-CNT in the Nafion matrix was achieved. ► Combined effect of montmorillonite and CNT improves the thermal stability of Nafion. - Abstract: Nafion based nanocomposite membranes containing montmorillonite-carbon nanotubes (a binary hybrid material) were produced to develop high performance polymer electrolyte fuel cells. Multi walled carbon nanotubes were grown over 20 and 25 wt% iron loaded montmorillonite catalysts by CVD using acetylene as the carbon precursor. Growth experiments were carried out at optimised conditions to obtain highly selective crystalline carbon nanotubes. X-ray diffraction spectra of the catalysts were recorded for the structural characterisation and definition of particle size. The carbon nanotubes obtained were examined by various physico chemical characterisation studies such as SEM, TEM, Raman spectroscopy and TG analyses to understand the morphology and crystallinity of the CNTs. The MM-CNT hybrid material with I D /I G ratio of Raman spectral band as 0.53 represents the high selectivity towards CNTs. Thus the hybrid material produced was considered as the best nanofiller to develop polymer nanocomposites. Nafion based nanocomposite membranes were prepared by adding MM-CNT as nanofiller by solution casting method. A better dispersion of MM-CNT into the Nafion matrix was observed and the addition of the MM-CNT improved the thermal stability of the Nafion membrane.

  7. Modification of electrical properties of polymer membranes by ion implantation

    International Nuclear Information System (INIS)

    Dworecki, K.; Hasegawa, T.; Sudlitz, K.; Wasik, S.

    2000-01-01

    This paper presents an experimental study of the electrical properties of polymer ion irradiated polyethylene terephthalate (PET) membranes. The polymer samples have been implanted with a variety of ions (O 5+ , N 4+ , Kr 9+ ) by the energy of 10 keV/q up to doses of 10 15 ions/cm 2 and then they were polarized in an electric field of 4.16x10 6 V/m at non-isothermal conditions. The electrical properties and the changes in the chemical structure of implanted membrane were measured by conductivity and discharge currents and FTIR spectra. Electrical conductivity of the membranes PET increases to 1-3 orders of magnitude after implantation and is determined by the charge transport caused by free space charge and by thermal detrapping of charge carriers. The spectra of thermally induced discharge current (TDC) shows that ion irradiated PET membranes are characterized by high ability to accumulate charge

  8. 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......An ultra-thin proton exchange membrane with Pt-nanosheet catalysts was designed for a self-humidifying fuel cell running on H2 and O2. In this design, an ultra-thin Nafion membrane was used to reduce ohmic resistance. Pt nanocatalysts were uniformly anchored on exfoliated, layered double hydroxide...

  9. Polymer coatings as separator layers for microbial fuel cell cathodes

    KAUST Repository

    Watson, Valerie J.

    2011-03-01

    Membrane separators reduce oxygen flux from the cathode into the anolyte in microbial fuel cells (MFCs), but water accumulation and pH gradients between the separator and cathode reduces performance. Air cathodes were spray-coated (water-facing side) with anion exchange, cation exchange, and neutral polymer coatings of different thicknesses to incorporate the separator into the cathode. The anion exchange polymer coating resulted in greater power density (1167 ± 135 mW m-2) than a cation exchange coating (439 ± 2 mW m-2). This power output was similar to that produced by a Nafion-coated cathode (1114 ± 174 mW m-2), and slightly lower than the uncoated cathode (1384 ± 82 mW m-2). Thicker coatings reduced oxygen diffusion into the electrolyte and increased coulombic efficiency (CE = 56-64%) relative to an uncoated cathode (29 ± 8%), but decreased power production (255-574 mW m-2). Electrochemical characterization of the cathodes ex situ to the MFC showed that the cathodes with the lowest charge transfer resistance and the highest oxygen reduction activity produced the most power in MFC tests. The results on hydrophilic cathode separator layers revealed a trade off between power and CE. Cathodes coated with a thin coating of anion exchange polymer show promise for controlling oxygen transfer while minimally affecting power production. © 2010 Elsevier B.V. All rights reserved.

  10. A NOVEL HYDROPHILIC POLYMER MEMBRANE FOR THE DEHYDRATION OF ORGANIC SOLVENTS

    Science.gov (United States)

    Novel hydrophilic polymer membranes based on polyallylamine ydrochloride- polyvinylalcohol are developed. The high selectivity and flux characteristics of these membranes for the dehydration of organic solvents are evaluated using pervaporation technology and are found to be ver...

  11. Improved antifouling properties of polymer membranes using a ‘layer-by-layer’ mediated method

    KAUST Repository

    Chen, Lin

    2013-01-01

    Polymeric reverse osmosis membranes were modified with antifouling polymer brushes through a \\'layer by layer\\' (LBL) mediated method. Based on pure physical electrostatic interaction, the attachment of LBL films did not alter separation performance of the membranes. In addition, the incorporation of an LBL film also helped to amplify the number of potential reaction sites on the membrane surfaces for attachment of antifouling polymer brushes, which were then attached to the surface. Attachment of the brushes included two different approaches, grafting to and grafting from. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and water contact angle measurements showed successful growth of the LBL films and subsequently the polymer brushes. Using this method to modify reverse osmosis membranes, preliminary performance testing showed the antifouling properties of the as-modified membranes were much better than the virgin membrane with no significant loss in water flux and salt rejection. © 2013 The Royal Society of Chemistry.

  12. Empirical membrane lifetime model for heavy duty fuel cell systems

    Science.gov (United States)

    Macauley, Natalia; Watson, Mark; Lauritzen, Michael; Knights, Shanna; Wang, G. Gary; Kjeang, Erik

    2016-12-01

    Heavy duty fuel cells used in transportation system applications such as transit buses expose the fuel cell membranes to conditions that can lead to lifetime-limiting membrane failure via combined chemical and mechanical degradation. Highly durable membranes and reliable predictive models are therefore needed in order to achieve the ultimate heavy duty fuel cell lifetime target of 25,000 h. In the present work, an empirical membrane lifetime model was developed based on laboratory data from a suite of accelerated membrane durability tests. The model considers the effects of cell voltage, temperature, oxygen concentration, humidity cycling, humidity level, and platinum in the membrane using inverse power law and exponential relationships within the framework of a general log-linear Weibull life-stress statistical distribution. The obtained model is capable of extrapolating the membrane lifetime from accelerated test conditions to use level conditions during field operation. Based on typical conditions for the Whistler, British Columbia fuel cell transit bus fleet, the model predicts a stack lifetime of 17,500 h and a membrane leak initiation time of 9200 h. Validation performed with the aid of a field operated stack confirmed the initial goal of the model to predict membrane lifetime within 20% of the actual operating time.

  13. 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.

  14. Biomass Biorefinery for the production of Polymers and Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Oliver P. Peoples

    2008-05-05

    The conversion of biomass crops to fuel is receiving considerable attention as a means to reduce our dependence on foreign oil imports and to meet future energy needs. Besides their use for fuel, biomass crops are an attractive vehicle for producing value added products such as biopolymers. Metabolix, Inc. of Cambridge proposes to develop methods for producing biodegradable polymers polyhydroxyalkanoates (PHAs) in green tissue plants as well as utilizating residual plant biomass after polymer extraction for fuel generation to offset the energy required for polymer extraction. The primary plant target is switchgrass, and backup targets are alfalfa and tobacco. The combined polymer and fuel production from the transgenic biomass crops establishes a biorefinery that has the potential to reduce the nation’s dependence on foreign oil imports for both the feedstocks and energy needed for plastic production. Concerns about the widespread use of transgenic crops and the grower’s ability to prevent the contamination of the surrounding environment with foreign genes will be addressed by incorporating and expanding on some of the latest plant biotechnology developed by the project partners of this proposal. This proposal also addresses extraction of PHAs from biomass, modification of PHAs so that they have suitable properties for large volume polymer applications, processing of the PHAs using conversion processes now practiced at large scale (e.g., to film, fiber, and molded parts), conversion of PHA polymers to chemical building blocks, and demonstration of the usefulness of PHAs in large volume applications. The biodegradability of PHAs can also help to reduce solid waste in our landfills. If successful, this program will reduce U.S. dependence on imported oil, as well as contribute jobs and revenue to the agricultural economy and reduce the overall emissions of carbon to the atmosphere.

  15. Polymer-metal organic frameworks (MOFs) mixed matrix membranes for gas separation applications

    NARCIS (Netherlands)

    Shahid, S.

    2015-01-01

    The performance of polymeric membranes is often limited by a trade-off between membrane permeability and selectivity, the so-called Robeson upper bound. Additionally, in high pressure CO2 capture applications, excessive swelling of the polymer membrane often leads to plasticization resulting in

  16. A novel sulfonated poly(ether ether ketone) and cross-linked membranes for fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hongtao; Zhang, Gang; Wu, Jing; Zhao, Chengji; Zhang, Yang; Shao, Ke; Han, Miaomiao; Lin, Haidan; Zhu, Jing; Na, Hui [Alan G MacDiarmid Institute, College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, Jilin (China)

    2010-10-01

    A novel poly(ether ether ketone) (PEEK) containing pendant carboxyl groups has been synthesized by a nucleophilic polycondensation reaction. Sulfonated polymers (SPEEKs) with different ion exchange capacity are then obtained by post-sulfonation process. The structures of PEEK and SPEEKs are characterized by both FT-IR and {sup 1}H NMR. The properties of SPEEKs as candidates for proton exchange membranes are studied. The cross-linking reaction is performed at 140 C using poly(vinyl alcohol) (PVA) as the cross-linker. In comparison with the non-cross-linked membranes, some properties of the cross-linked membranes are significantly improved, such as water uptake, methanol resistance, mechanical and oxidative stabilities, while the proton conductivity decreases. The effect of PVA content on proton conductivity, water uptake, swelling ratio, and methanol permeability is also investigated. Among all the membranes, SPEEK-C-8 shows the highest selectivity of 50.5 x 10{sup 4} S s cm{sup -3}, which indicates that it is a suitable candidate for applications in direct methanol fuel cells. (author)

  17. Sulfonation of PEEK-WC polymer via chloro-sulfonic acid for potential PEM fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Iulianelli, A.; Clarizia, G.; Gugliuzza, A.; Ebrasu, D.; Basile, A. [Institute on Membrane Technology, ITM-CNR, c/o University of Calabria, Via P. Bucci, Cubo 17/C, 87030 Rende (CS) (Italy); Bevilacqua, A. [Research Centre Italsistemi S.r.l., Via Avogadro, 88900 Crotone (KR) (Italy); Trotta, F. [Department of Organic Chemistry, University of Torino, C.So M. D' Azeglio 48, 10125 Torino (TO) (Italy)

    2010-11-15

    The preparation and characterization of thin dense sulfonated poly-ether-ether-ketone with cardo group (PEEK-WC) membranes for proton exchange membrane fuel cell (PEMFC) applications are described. The sulfonation of PEEK-WC polymer was realized via chloro-sulfonic acid and different kinds of membrane samples were prepared with a sulfonation degree ranging from 67 to 99%. The degree of sulfonation, homogeneity and thickness significantly affect both the membrane transport properties and the electrochemical performances. The dense character of the membranes was confirmed by SEM analysis. Proton conductivity measurements were carried out in a temperature range from 30 to 80 C and at 100% of relative humidity, reaching 5.40 x 10{sup -3} S/cm{sup -1} as best value at 80 C and with a sulfonation degree (DS) of 99%. At the same conditions, a water uptake of 17% was achieved. DSC and TGA characterizations were used in order to determine the thermal stability of the membranes, confirming a T{sub g} ranging between 206 and 216 C depending on the DS, whereas FT-IR yielded indication about intermolecular interactions and water uptake at various sulfonation degrees. (author)

  18. Intrinsically Microporous Polymer Membranes for High Performance Gas Separation

    KAUST Repository

    Swaidan, Raja

    2014-01-01

    This dissertation addresses the rational design of intrinsically microporous solutionprocessable polyimides and ladder polymers for highly permeable and highly selective gas transport in cornerstone applications of membrane-based gas separation

  19. Electrochemical impedance spectroscopy analysis of a thin polymer film-based micro-direct methanol fuel cell

    Science.gov (United States)

    Schulz, Tobias; Weinmüller, Christian; Nabavi, Majid; Poulikakos, Dimos

    A single cell micro-direct methanol fuel cell (micro-DMFC) was investigated using electrochemical impedance spectroscopy. The electrodes consisted of thin, flexible polymer (SU8) film microchannel structures fabricated in-house using microfabrication techniques. AC impedance spectroscopy was used to separate contributions to the overall cell polarization from the anode, cathode and membrane. A clear distinction between the different electrochemical phenomena occurring in the micro-DMFC, especially the distinction between double layer charging and Faradaic reactions was shown. The effect of fuel flow rate, temperature, and anode flow channel structure on the impedance of the electrode reactions and membrane/electrode double layer charging were investigated. Analysis of impedance data revealed that the performance of the test cell was largely limited by the presence of intermediate carbon monoxide in the anode reaction. Higher temperatures increase cell performance by enabling intermediate CO to be oxidized at much higher rates. The results also revealed that serpentine anode flow microchannels show a lower tendency to intermediate CO coverage and a more stable cell behavior than parallel microchannels.

  20. Application of Photocured Polymer Ion Selective Membranes for Solid-State Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Natalia Abramova

    2015-06-01

    Full Text Available Application of conducting polymers with additional functional groups for a solid contact formation and photocurable membranes as sensitive elements of solid-state chemical sensors is discussed. Problems associated with application of UV-curable polymers for sensors are analyzed. A method of sensor fabrication using copolymerized conductive layer and sensitive membrane is presented and the proof of concept is confirmed by two examples of solid-contact electrodes for Ca ions and pH.

  1. Design of an optical thermal sensor for proton exchange membrane fuel cell temperature measurement using phosphor thermometry

    Science.gov (United States)

    Inman, Kristopher; Wang, Xia; Sangeorzan, Brian

    Internal temperatures in a proton exchange membrane (PEM) fuel cell govern the ionic conductivities of the polymer electrolyte, influence the reaction rate at the electrodes, and control the water vapor pressure inside the cell. It is vital to fully understand thermal behavior in a PEM fuel cell if performance and durability are to be optimized. The objective of this research was to design, construct, and implement thermal sensors based on the principles of the lifetime-decay method of phosphor thermometry to measure temperatures inside a PEM fuel cell. Five sensors were designed and calibrated with a maximum uncertainty of ±0.6 °C. Using these sensors, surface temperatures were measured on the cathode gas diffusion layer of a 25 cm 2 PEM fuel cell. The test results demonstrate the utility of the optical temperature sensor design and provide insight into the thermal behavior found in a PEM fuel cell.

  2. Methods of conditioning direct methanol fuel cells

    Science.gov (United States)

    Rice, Cynthia; Ren, Xiaoming; Gottesfeld, Shimshon

    2005-11-08

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

  3. Efficiency of Polymer Electrolyte Membrane Fuel Cell Stack

    Directory of Open Access Journals (Sweden)

    Hans Bosma

    2011-08-01

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

  4. A sacrificial process for fabrication of biodegradable polymer membranes with submicron thickness.

    Science.gov (United States)

    Beardslee, Luke A; Stolwijk, Judith; Khaladj, Dimitrius A; Trebak, Mohamed; Halman, Justin; Torrejon, Karen Y; Niamsiri, Nuttawee; Bergkvist, Magnus

    2016-08-01

    A new sacrificial molding process using a single mask has been developed to fabricate ultrathin 2-dimensional membranes from several biocompatible polymeric materials. The fabrication process is similar to a sacrificial microelectromechanical systems (MEMS) process flow, where a mold is created from a material that can be coated with a biodegradable polymer and subsequently etched away, leaving behind a very thin polymer membrane. In this work, two different sacrificial mold materials, silicon dioxide (SiO2 ) and Liftoff Resist (LOR) were used. Three different biodegradable materials; polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and polyglycidyl methacrylate (PGMA), were chosen as model polymers. We demonstrate that this process is capable of fabricating 200-500 nm thin, through-hole polymer membranes with various geometries, pore-sizes and spatial features approaching 2.5 µm using a mold fabricated via a single contact photolithography exposure. In addition, the membranes can be mounted to support rings made from either SU8 or PCL for easy handling after release. Cell culture compatibility of the fabricated membranes was evaluated with human dermal microvascular endothelial cells (HDMECs) seeded onto the ultrathin porous membranes, where the cells grew and formed confluent layers with well-established cell-cell contacts. Furthermore, human trabecular meshwork cells (HTMCs) cultured on these scaffolds showed similar proliferation as on flat PCL substrates, further validating its compatibility. All together, these results demonstrated the feasibility of our sacrificial fabrication process to produce biocompatible, ultra-thin membranes with defined microstructures (i.e., pores) with the potential to be used as substrates for tissue engineering applications. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1192-1201, 2016. © 2015 Wiley Periodicals, Inc.

  5. Diffuse Charge Effects in Fuel Cell Membranes

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Franco, A.A.; Bazant, M.Z.

    2009-01-01

    It is commonly assumed that electrolyte membranes in fuel cells are electrically neutral, except in unsteady situations, when the double-layer capacitance is heuristically included in equivalent circuit calculations. Indeed, the standard model for electron transfer kinetics at the membrane/electrode

  6. Development of Nanoporous Polymer Membranes by Swift Heavy Ion Irradiation

    Science.gov (United States)

    Dinesh, Divya; Predeep, P.

    2011-10-01

    This study reveals the preparation of conical pores in polyethylene terephthalate (PET) by track etching. The polymer membrane is etched from one side by keeping between the clamps of conductivity cell followed by irradiation with swift heavy ion of 197Au. Electrical stopping supports chemical stopping. During etching process current is measured as a function of time till a sharp increase -breakthrough-observed. After etching membranes are thoroughly washed with stopping solution and water. Resultant films are characterized using Optical microscope and field emission scanning electron microscopy. Polymer films with uniform pores can be a cheaper templating material in the fields of photonic crystals and micro- electronics.

  7. 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.

  8. Polymer-SnO2 composite membranes

    DEFF Research Database (Denmark)

    Nørgaard, Casper Frydendal; Skou, Eivind Morten

    . This work utilizes the latter approach and makes use of particles of tin dioxide (SnO2). Polymer-SnO2 composite membranes were successfully prepared using an ion-exchange method. SnO2 was incorporated into membranes by ion-exchange in solutions of SnCl2 ∙ 2 H2O in methanol, followed by oxidation to SnO2...... in air. The content of SnO2 proved controllable by adjusting the concentration of the ion-exchange solution. The prepared nanocomposite membranes were characterized by powder XRD, 119Sn MAS NMR, electrochemical impedance spectroscopy, water uptake and tensile stress-strain measurements. For Nafion 117...

  9. Hydrogen fuel cells for cars and buses

    NARCIS (Netherlands)

    Janssen, L.J.J.

    2007-01-01

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

  10. Biomolecule-recognition gating membrane using biomolecular cross-linking and polymer phase transition.

    Science.gov (United States)

    Kuroki, Hidenori; Ito, Taichi; Ohashi, Hidenori; Tamaki, Takanori; Yamaguchi, Takeo

    2011-12-15

    We present for the first time a biomolecule-recognition gating system that responds to small signals of biomolecules by the cooperation of biorecognition cross-linking and polymer phase transition in nanosized pores. The biomolecule-recognition gating membrane immobilizes the stimuli-responsive polymer, including the biomolecule-recognition receptor, onto the pore surface of a porous membrane. The pore state (open/closed) of this gating membrane depends on the formation of specific biorecognition cross-linking in the pores: a specific biomolecule having multibinding sites can be recognized by several receptors and acts as the cross-linker of the grafted polymer, whereas a nonspecific molecule cannot. The pore state can be distinguished by a volume phase transition of the grafted polymer. In the present study, the principle of the proposed system is demonstrated using poly(N-isopropylacrylamide) as the stimuli-responsive polymer and avidin-biotin as a multibindable biomolecule-specific receptor. As a result of the selective response to the specific biomolecule, a clear permeability change of an order of magnitude was achieved. The principle is versatile and can be applied to many combinations of multibindable analyte-specific receptors, including antibody-antigen and lectin-sugar analogues. The new gating system can find wide application in the bioanalytical field and aid the design of novel biodevices.

  11. The Effect of Covalently-Attached ATRP-Synthesized Polymers on Membrane Stability and Cytoprotection in Human Erythrocytes.

    Science.gov (United States)

    Clafshenkel, William P; Murata, Hironobu; Andersen, Jill; Creeger, Yehuda; Koepsel, Richard R; Russell, Alan J

    2016-01-01

    Erythrocytes have been described as advantageous drug delivery vehicles. In order to ensure an adequate circulation half-life, erythrocytes may benefit from protective enhancements that maintain membrane integrity and neutralize oxidative damage of membrane proteins that otherwise facilitate their premature clearance from circulation. Surface modification of erythrocytes using rationally designed polymers, synthesized via atom-transfer radical polymerization (ATRP), may further expand the field of membrane-engineered red blood cells. This study describes the fate of ATRP-synthesized polymers that were covalently attached to human erythrocytes as well as the effect of membrane engineering on cell stability under physiological and oxidative conditions in vitro. The biocompatible, membrane-reactive polymers were homogenously retained on the periphery of modified erythrocytes for at least 24 hours. Membrane engineering stabilized the erythrocyte membrane and effectively neutralized oxidative species, even in the absence of free-radical scavenger-containing polymers. The targeted functionalization of Band 3 protein by NHS-pDMAA-Cy3 polymers stabilized its monomeric form preventing aggregation in the presence of the crosslinking reagent, bis(sulfosuccinimidyl)suberate (BS3). A free radical scavenging polymer, NHS-pDMAA-TEMPO˙, provided additional protection of surface modified erythrocytes in an in vitro model of oxidative stress. Preserving or augmenting cytoprotective mechanisms that extend circulation half-life is an important consideration for the use of red blood cells for drug delivery in various pathologies, as they are likely to encounter areas of imbalanced oxidative stress as they circuit the vascular system.

  12. The Effect of Covalently-Attached ATRP-Synthesized Polymers on Membrane Stability and Cytoprotection in Human Erythrocytes.

    Directory of Open Access Journals (Sweden)

    William P Clafshenkel

    Full Text Available Erythrocytes have been described as advantageous drug delivery vehicles. In order to ensure an adequate circulation half-life, erythrocytes may benefit from protective enhancements that maintain membrane integrity and neutralize oxidative damage of membrane proteins that otherwise facilitate their premature clearance from circulation. Surface modification of erythrocytes using rationally designed polymers, synthesized via atom-transfer radical polymerization (ATRP, may further expand the field of membrane-engineered red blood cells. This study describes the fate of ATRP-synthesized polymers that were covalently attached to human erythrocytes as well as the effect of membrane engineering on cell stability under physiological and oxidative conditions in vitro. The biocompatible, membrane-reactive polymers were homogenously retained on the periphery of modified erythrocytes for at least 24 hours. Membrane engineering stabilized the erythrocyte membrane and effectively neutralized oxidative species, even in the absence of free-radical scavenger-containing polymers. The targeted functionalization of Band 3 protein by NHS-pDMAA-Cy3 polymers stabilized its monomeric form preventing aggregation in the presence of the crosslinking reagent, bis(sulfosuccinimidylsuberate (BS3. A free radical scavenging polymer, NHS-pDMAA-TEMPO˙, provided additional protection of surface modified erythrocytes in an in vitro model of oxidative stress. Preserving or augmenting cytoprotective mechanisms that extend circulation half-life is an important consideration for the use of red blood cells for drug delivery in various pathologies, as they are likely to encounter areas of imbalanced oxidative stress as they circuit the vascular system.

  13. 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

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

    International Nuclear Information System (INIS)

    Ogawa, Kuniyasu; Ito, Kohei; Haishi, Tomoyuki

    2007-01-01

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

  15. Conductive polymer layers to limit transfer of fuel reactants to catalysts of fuel cells to reduce reactant crossover

    Science.gov (United States)

    Stanis, Ronald J.; Lambert, Timothy N.

    2016-12-06

    An apparatus of an aspect includes a fuel cell catalyst layer. The fuel cell catalyst layer is operable to catalyze a reaction involving a fuel reactant. A fuel cell gas diffusion layer is coupled with the fuel cell catalyst layer. The fuel cell gas diffusion layer includes a porous electrically conductive material. The porous electrically conductive material is operable to allow the fuel reactant to transfer through the fuel cell gas diffusion layer to reach the fuel cell catalyst layer. The porous electrically conductive material is also operable to conduct electrons associated with the reaction through the fuel cell gas diffusion layer. An electrically conductive polymer material is coupled with the fuel cell gas diffusion layer. The electrically conductive polymer material is operable to limit transfer of the fuel reactant to the fuel cell catalyst layer.

  16. Polymer-inorganic hybrid proton conductive membranes: Effect of the interfacial transfer pathways

    International Nuclear Information System (INIS)

    Chen, Pingping; Hao, Lie; Wu, Wenjia; Li, Yifan; Wang, Jingtao

    2016-01-01

    Highlights: • A series of hybrid membranes are prepared using fillers with different structures. • The fillers (0-D, 1-D, and 2-D) are sulfonated to ensure close surface component. • The effect of filler’s structure on microstructure of hydrid membrane is explored. • For single-kind filler series, 2-D filler has the strongest conduction promotion. • The synergy effect of different kinds of fillers is systematacially investigated. - Abstract: For hybrid membrane, the polymer-inorganic interface along filler surface can be facilely created to be distinctive and controllable pathway for mass transfer. Herein, three kinds of fillers are used as inorganic additives including zero-dimensional silica (0-D, SiO_2), one-dimensional halloysite nanotube (1-D, HNT), and two-dimensional graphene oxide (2-D, GO), which are functionalized by sulfonated polymer layer to ensure close surface component. Then the fillers are incorporated into two types of polymer matrixes (phase-separated sulfonated poly(ether ether ketone) and non-phase-separated chitosan) to prepare three series of hybrid membranes with single-kind filler, double-kinds fillers, or triple-kinds fillers, respectively. The microstructures, physicochemical properties, and proton conduction properties (under hydrated and anhydrous conditions) of the membranes are extensively investigated. It is found that (i) for the single-kind filler-filled membranes, 2-D filler has the strongest promotion ability for proton conductivity of membrane due to the constructed wide and long-range pathways for proton transfer; (ii) while for the hybrid membranes with double-kinds fillers, instead of synergistic promotion effect, the fillers cause more tortuous transfer pathways within membranes and then decrease proton conductivity; (iii) the hybrid membranes with triple-kinds fillers exhibit similar behavior but a little higher conductivity than the membranes with double-kinds fillers.

  17. Sulfonated carbon black-based composite membranes for fuel cell

    Indian Academy of Sciences (India)

    Composite membranes were then prepared using S–C as fillers and sulfonated poly(ether ether ketone) (SPEEK) as polymer matrix with three different sulfonation degrees (DS = 60, 70 and 82%). Structure and properties of the composite membranes were characterized by FTIR, TGA, scanning electron microscopy, proton ...

  18. Carbon nanotubes rooted montmorillonite (CNT-MM) reinforced nanocomposite membrane for PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Manikandan, Dhanagopal, E-mail: dmani_cat@yahoo.co.in [Department of Materials Engineering, Faculty of Engineering, University of Concepcion, Concepcion (Chile); Mangalaraja, Ramalinga Viswanathan, E-mail: mangal@udec.cl [Department of Materials Engineering, Faculty of Engineering, University of Concepcion, Concepcion (Chile); Avila, Ricardo E. [Personal Dosimetry Section, Chilean Nuclear Energy Commission, Cas. 188-D, Santiago (Chile); Siddheswaran, Rajendran [Department of Materials Engineering, Faculty of Engineering, University of Concepcion, Concepcion (Chile); Ananthakumar, Solaiappan [Materials and Minerals Division, National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum, Kerala (India)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Novel montmorillonite-CNT (MM-CNT) nanohybrid materials were produced by CVD. Black-Right-Pointing-Pointer Highly selective crystalline carbon nanotubes were grown over montmorillonite. Black-Right-Pointing-Pointer Fabricated Nafion-MM-CNT nanocomposite membrane by solution casting method. Black-Right-Pointing-Pointer Homogeneous dispersion of MM-CNT in the Nafion matrix was achieved. Black-Right-Pointing-Pointer Combined effect of montmorillonite and CNT improves the thermal stability of Nafion. - Abstract: Nafion based nanocomposite membranes containing montmorillonite-carbon nanotubes (a binary hybrid material) were produced to develop high performance polymer electrolyte fuel cells. Multi walled carbon nanotubes were grown over 20 and 25 wt% iron loaded montmorillonite catalysts by CVD using acetylene as the carbon precursor. Growth experiments were carried out at optimised conditions to obtain highly selective crystalline carbon nanotubes. X-ray diffraction spectra of the catalysts were recorded for the structural characterisation and definition of particle size. The carbon nanotubes obtained were examined by various physico chemical characterisation studies such as SEM, TEM, Raman spectroscopy and TG analyses to understand the morphology and crystallinity of the CNTs. The MM-CNT hybrid material with I{sub D}/I{sub G} ratio of Raman spectral band as 0.53 represents the high selectivity towards CNTs. Thus the hybrid material produced was considered as the best nanofiller to develop polymer nanocomposites. Nafion based nanocomposite membranes were prepared by adding MM-CNT as nanofiller by solution casting method. A better dispersion of MM-CNT into the Nafion matrix was observed and the addition of the MM-CNT improved the thermal stability of the Nafion membrane.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-03-30

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

  20. Grafting of Styrene onto Commercial Polytetrafluorethylene (PTFE) Membrane and Sulfonation for Possible use in Fuel Cell

    International Nuclear Information System (INIS)

    Abdel-Hady, E.E.; Abdel-Hamed, M.O.; Hammam, A.M.; El-toony, M.M.

    2010-01-01

    The purpose of this work is to initiate the fundamental research necessary for the development of a novel proton-exchange membranes (PEM) to overcome the material and performance limitations of the s tate of the art N afion that is used in both hydrogen and methanol fuel cells. Silica was inserted in commercial PTFE membrane in ratio 8%. Gamma irradiation was used for grafting of different ratios of styrene onto the membrane in one and two steps. Methacrylic acid and styrene were used as binary monomers for grafting of such membranes to raise the grafting percentage. Thermal characterization of the grafted membrane was discussed using thermal gravimetric analysis (TGA). The mechanical properties were tested by measuring ultimate tensile value, and Young modulus. The positron annihilation lifetime spectroscopy has been used to investigate the free volume hole size, while the surface morphology of the membrane was studied by scanning electron microscope (SEM). It was found that the maximum water uptake of the sulfonated membrane reached 20% by weight. The proton conductivity of the prepared polymer electrolyte was measured by ac impedance spectroscopic analysis. And it was found to be 0.9 x 10 -4 ohm -1 cm -1 .

  1. Crystal nuclei templated nanostructured membranes prepared by solvent crystallization and polymer migration

    Science.gov (United States)

    Wang, Bo; Ji, Jing; Li, Kang

    2016-09-01

    Currently, production of porous polymeric membranes for filtration is predominated by the phase-separation process. However, this method has reached its technological limit, and there have been no significant breakthrough over the last decade. Here we show, using polyvinylidene fluoride as a sample polymer, a new concept of membrane manufacturing by combining oriented green solvent crystallization and polymer migration is able to obtain high performance membranes with pure water permeation flux substantially higher than those with similar pore size prepared by conventional phase-separation processes. The new manufacturing procedure is governed by fewer operating parameters and is, thus, easier to control with reproducible results. Apart from the high water permeation flux, the prepared membranes also show excellent stable flux after fouling and superior mechanical properties of high pressure load and better abrasion resistance. These findings demonstrate the promise of a new concept for green manufacturing nanostructured polymeric membranes with high performances.

  2. Synthesis of Thin Film Composite Metal-Organic Frameworks Membranes on Polymer Supports

    KAUST Repository

    Barankova, Eva

    2017-06-01

    Since the discovery of size-selective metal-organic frameworks (MOF) researchers have tried to manufacture them into gas separation membranes. ZIF-8 became the most studied MOF for membrane applications mainly because of its simple synthesis, good chemical and thermal stability, recent commercial availability and attractive pore size. The aim of this work is to develop convenient methods for growing ZIF thin layers on polymer supports to obtain defect-free ZIF membranes with good gas separation properties. We present new approaches for ZIF membranes preparation on polymers. We introduce zinc oxide nanoparticles in the support as a secondary metal source for ZIF-8 growth. Initially the ZnO particles were incorporated into the polymer matrix and later on the surface of the polymer by magnetron sputtering. In both cases, the ZnO facilitated to create more nucleation opportunities and improved the ZIF-8 growth compared to the synthesis without using ZnO. By employing the secondary seeded growth method, we were able to obtain thin (900 nm) ZIF-8 layer with good gas separation performance. Next, we propose a metal-chelating polymer as a suitable support for growing ZIF layers. Defect-free ZIF-8 films with a thickness of 600 nm could be obtained by a contra-diffusion method. ZIF-8 membranes were tested for permeation of hydrogen and hydrocarbons, and one of the highest selectivities reported so far for hydrogen/propane, and propylene/propane was obtained. Another promising method to facilitate the growth of MOFs on polymeric supports is the chemical functionalization of the support surface with functional groups, which can complex metal ions and which can covalently bond the MOF crystals. We functionalized the surface of a common porous polymeric membrane with amine groups, which took part in the reaction to form ZIF-8 nanocrystals. We observed an enhancement in adhesion between the ZIF layer and the support. The effect of parameters of the contra-diffusion experiment

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

    OpenAIRE

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

    2013-01-01

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

  4. Application of the nanocomposite membrane as electrolyte of proton exchange membrane fuel cell

    International Nuclear Information System (INIS)

    Mahreni

    2010-01-01

    Hydrogen fuel cells proton exchange membrane fuel cell (PEMFC) is currently still in development and commercialization. Several barriers to the commercialization of these Nafion membrane as electrolyte is its very sensitive to humidity fluctuation. Nafion must be modified by making a composite Nafion-SiO 2 -HPA to increase electrolyte resistance against humidity fluctuations during the cell used. Research carried out by mixing Nafion solution with Tetra Ethoxy Ortho Silicate (TEOS) and conductive materials is phosphotungstic acid (PWA) by varying the ratio of Nafion, TEOS and PWA. The membrane is produced by heating a mixture of Nafion, TEOS and PWA by varying the evaporation temperature, time and annealing temperature to obtain the transparent membrane. The resulting membrane was analyzed its physical, chemical and electrochemical properties by applying the membrane as electrolyte of PEMFC at various humidity and temperature of operation. The results showed that at low temperatures (30-90 °C) and high humidity at 100 % RH, pure Nafion membrane is better than composite membrane (Nafion-SiO 2 -PWA), but at low humidity condition composite membrane is better than the pure Nafion membrane. It can be concluded that the composite membranes of (Nafion-SiO 2 -PWA) can be used as electrolyte of PEMFC operated at low humidity (40 % RH) and temperature between (30-90 °C). (author)

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

    Science.gov (United States)

    Halpert, G.; Surampudi, S.

    1994-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Johanna K. Dombrovskis

    2014-12-01

    Full Text Available Transition metal ion-chelating ordered mesoporous carbon (TM-OMC materials were recently shown to be efficient polymer electrolyte membrane fuel cell (PEMFC catalysts. The structure and properties of these catalysts are largely different from conventional catalyst materials, thus rendering membrane electrode assembly (MEA preparation parameters developed for conventional catalysts not useful for applications of TM-OMC catalysts. This necessitates development of a methodology to incorporate TM-OMC catalysts in the MEA. Here, an efficient method for MEA preparation using TM-OMC catalyst materials for PEMFC is developed including effects of catalyst/ionomer loading and catalyst/ionomer-mixing and application procedures. An optimized protocol for MEA preparation using TM-OMC catalysts is described.

  7. Hybrid polymer composite membrane for an electromagnetic (EM) valveless micropump

    Science.gov (United States)

    Said, Muzalifah Mohd; Yunas, Jumril; Bais, Badariah; Azlan Hamzah, Azrul; Yeop Majlis, Burhanuddin

    2017-07-01

    In this paper, we report on a hybrid membrane used as an actuator in an electromagnetically driven valveless micropump developed using MEMS processes. The membrane structure consists of the combination of a magnetic polymer composite membrane and an attached bulk permanent magnet which is expected to have a compact structure and a strong magnetic force with maintained membrane flexibility. A soft polymeric material made of polydimethylsiloxane (PDMS) is initially mixed with neodymium magnetic particles (NdFeB) to form a magnetic polymer composite membrane. The membrane is then bonded with the PDMS based microfluidic part, developed using soft lithography process. The developed micropump was tested in terms of the actuator membrane deflection capability and the fluidic flow of the injected fluid sample through the microfluidic channel. The experimental results show that the magnetic composite actuator membrane with an attached bulk permanent magnet is capable of producing a maximum membrane deflection of up to 106 µm. The functionality test of the electromagnetic (EM) actuator for fluid pumping purposes was done by supplying an AC voltage with various amplitudes, signal waves and frequencies. A wide range of sample injection rates from a few µl min-1 to tens of nl min-1 was achieved with a maximum flow rate of 6.6 µl min-1. The injection flow rate of the EM micropump can be controlled by adjusting the voltage amplitude and frequency supplied to the EM coil, to control the membrane deflection in the pump chamber. The designed valveless EM micropump has a very high potential to enhance the drug delivery system capability in biomedical applications.

  8. Modification of electrical properties of polymer membranes by ion implantation (II)

    International Nuclear Information System (INIS)

    Dworecki, K.; Hasegawa, T.; Sudlitz, K.; Slezak, A.; Wasik, S.

    2001-01-01

    In the present work we report on the results of an experimental study of the electrical properties of polymer ion irradiated polyethylene terephthalate (PET) membranes. The polymer samples have been implanted under vacuum at room temperature with a variety of ions (C 4+ , O 6+ , S 7+ ) at energy of 10 keV/q up to the dose of 10 15 ions/cm 2 and then they were polarized in an electric field of 4.16x10 6 V/m at non-isothermal conditions. The electrical properties and changes in chemical structure of ion implanted membranes were studied by the conductivity and discharge currents measurements, FTIR spectra and differential thermal analysis. The electrical conductivity of the PET membranes is determined by the charge transport caused by free space charge and by thermal releasing of charge carriers. The spectra of thermally induced discharge current (TDC) shows that ion irradiated PET membranes are characterized by high ability of charge accumulation

  9. Intrinsically Microporous Polymer Membranes for High Performance Gas Separation

    KAUST Repository

    Swaidan, Raja

    2014-11-01

    This dissertation addresses the rational design of intrinsically microporous solutionprocessable polyimides and ladder polymers for highly permeable and highly selective gas transport in cornerstone applications of membrane-based gas separation – that is, air enrichment, hydrogen recovery and natural gas sweetening. By virtue of rigid and contorted chains that pack inefficiently in the solid state, polymers of intrinsic microporosity (PIMs) have the potential to unite the solution-processability, mechanical flexibility and organic tunability of commercially relevant polymers with the microporosity characteristics of porous crystalline materials. The performance enhancements of PIMs over conventional low-free-volume polymers have been primarily permeability-driven, compromising the selectivity essential to commercial viability. An approach to unite high permeability with high selectivity for performance transcending the state-of-the-art in air and hydrogen separations was demonstrated via a fused-ring integration of a three-dimensional, shape persistent triptycene moiety optimally substituted with short, branched isopropyl chains at the 9,10-bridgeheads into a highly inflexible backbone. The resulting polymers exhibited selectivities (i.e., O2/N2, H2/N2, H2/CH4) similar to or higher than commercial materials matched with permeabilities up to three hundred times higher. However, the intra-chain rigidity central to such conventional PIM-design principles was not a singular solution to suppression of CO2-induced plasticization in CO2/CH4 mixedgas separations. Plasticization diminishes the sieving capacity of the membrane, resulting in costly hydrocarbon losses that have significantly limited the commercialization of new polymers. Unexpectedly, the most permeable and selective PIMs designed for air and hydrogen separations strongly plasticized in 50:50 CO2/CH4 mixtures, enduring up to three-fold increases in mixed-gas CH4 permeability by 30 bar and strong drops in

  10. Development and Characterization of Temperature-resistant Polymer Electrolytes

    DEFF Research Database (Denmark)

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

    1999-01-01

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

  11. Novel ceramic-polymer composite membranes for the separation of hazardous liquid waste. 1998 annual progress report

    International Nuclear Information System (INIS)

    Cohen, Y.

    1998-01-01

    'This report summarizes the work progress over the last 1.75 years of a 3 year project. The objectives of the project have been to develop a new class of ceramic-supported polymeric membranes that could be tailored-designed for a wide-range of applications in remediation and pollution prevention. To date, a new class of chemically-modified ceramic membranes was developed for the treatment of oil-in-water emulsions and for the pervaporation removal of volatile organics from aqueous systems. These new ceramic-supported polymer (CSP) membranes are fabricated by modifying the pore surface of a ceramic membrane support by a graft polymerization process (Chaimberg and Cohen, 1994). The graft polymerization process consists of activating the membrane surface with alkoxy vinyl silanes onto which vinyl monomers are added via free-radical graft polymerization resulting in a thin surface layer of terminally anchored polymer chains. Reaction conditions are selected based on knowledge of the graft polymerization kinetics for the specific polymer/substrate system. The resultant ceramic-supported polymer (CSP) membrane is a composite structure in which mechanical strength is provided by the ceramic support and the selectivity is determined by the covalently bonded polymer brush layer. Thus, one of the unique attributes of the CSP membrane is that it can be used in environments where the polymer layer is swollen (or even completely miscible) in the mixture to be separated (Castro et al., 1993). It is important to note that the above modification process is carried out under mild conditions (e.g., temperature of about 70 C) and is well suited for large scale commercial application. In a series of studies, the applicability of a polyvinylpyrrolidone CSP membrane was demonstrated for the treatment of oil-in-water emulsion under a variety of flow conditions (Castro et al.,1996). Improved membrane performance was achieved due to minimization of surface adsorption of the oil components

  12. Electrolytic membrane formation of fluoroalkyl polymer using a UV-radiation-based grafting technique and sulfonation

    Energy Technology Data Exchange (ETDEWEB)

    Shironita, Sayoko; Mizoguchi, Satoko; Umeda, Minoru, E-mail: mumeda@vos.nagaokaut.ac.jp [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka 940-2188, Niigata (Japan)

    2011-03-15

    A sulfonated fluoroalkyl graft polymer (FGP) membrane was prepared as a polymer electrolyte. First, the FGP membrane was grafted with styrene under UV irradiation. The grafted FGP was then sulfonated to functionalize it for proton conductivity. The grafting degree of the membrane increased with increasing grafting time during UV irradiation. The proton conductivity of the membrane increased with increasing grafting degree. The swelling ratio was independent of the grafting time, however, the water uptake increased with increasing grafting degree. Based on these results, it was found that the UV-initiated styrene grafting occurred along the membrane thickness direction. Moreover, the membrane was embedded within the glass fibers of the composite. This composite electrolytic membrane had 1.15 times the proton conductivity of a Nafion 117 membrane.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevan, Kathyayani

    2011-10-04

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-30

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

  15. Polyarylenethioethersulfone Membranes for Fuel Cells (Postprint)

    Science.gov (United States)

    2010-01-01

    The Electrochemical SocietyProton exchange membrane fuel cells PEMFCs are an attrac- tive power source due to their energy efficiency and...standard in PEMFC technology.3,4 Nafion membranes have a polytetrafluoro- ethylene PTFE backbone, which provides thermal and chemical stability, and...diffusion layers to fabricate MEAs. Single-cell test (H- PEMFC ).— MEAs were positioned in a single-cell fixture with graphite blocks as current

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

    CSIR Research Space (South Africa)

    Lou, H

    2009-10-01

    Full Text Available was added to the 15 wt% of SsPEEK-WC solution in NMP with magnetic stir. The solution was cast on a glass Petri dish. The solvent was then removed in a vacuum oven at 130 °C. The membrane was peeled off from the Petri dish. Thereafter, the membrane... and polyetherketone for fuel cell applications. Journal of Membrane Science, 2001. 185(1): p. 41-58. [6] Kerres, J.A., Development of ionomer membranes for fuel cells. Journal of Membrane Science, 2001. 185(1): p. 3-27. [7] Basile, A.; Paturzo, L.; Iulianelli, A...

  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. Novel ceramic-polymer composite membranes for the separation of liquid waste. Annual progress report, September 15, 1996 - September 14, 1997

    International Nuclear Information System (INIS)

    Cohen, Y.

    1997-01-01

    'The project on ceramic-supported polymer membranes focuses on the development of a novel class of membranes for the separation of organics from both organic-aqueous and organic-organic mixtures, Theses membranes are fabricated by a graft polymerization process where polymer chains are grown onto the surface of a ceramic support membrane. The surface graft polymerization process, developed at UCLA, results in the formation of a thin polymer layer covalently bonded to the membrane pore surface as a layer of terminally anchored polymeric chains. Through the selection of the polymer most appropriate for the desired separation task, the graft polymerized surface layer can be synthesized to impart specific separation properties to the membrane. It is expected that this project will lead to the demonstration of a new technology for the tailor design of a new class of selective and robust ceramic-supported polymer membranes. This new approach will allow the rapid deployment of task-specific membranes for the separation of waste constituents for subsequent recovery, treatment or disposal. Progress to date includes the preparation of successful silica-polyvinylpyrrolidone (PVP) membrane for the treatment of oil-in-water emulsions and a silica-polyvinylacetate (PVAc) pervaporation membrane for the separation of organics from water. Current work is ongoing to study the performance of the pervaporation membrane for the removal of chlorinated organics from water and to develop a pervaporation membrane for organic-organic separation. In another aspect of the study, the authors are studying the hydrophilic PVP CSP membrane for oil-in-water emulsion treatment with the goal of determining the optimal membrane polymer surface structure as a function of various operating conditions (e.g., tube-side Reynolds number and transmembrane pressure), Work is also in progress to characterize the polymer layer by AFM and internal reflection FTIR, and to model the conformation of the polymer

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

    Directory of Open Access Journals (Sweden)

    Dietmar Gerteisen

    2013-09-01

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

  20. Research on the Changes to the Lipid/Polymer Membrane Used in the Acidic Bitterness Sensor Caused by Preconditioning

    Directory of Open Access Journals (Sweden)

    Yuhei Harada

    2016-02-01

    Full Text Available A taste sensor that uses lipid/polymer membranes can evaluate aftertastes felt by humans using Change in membrane Potential caused by Adsorption (CPA measurements. The sensor membrane for evaluating bitterness, which is caused by acidic bitter substances such as iso-alpha acid contained in beer, needs an immersion process in monosodium glutamate (MSG solution, called “MSG preconditioning”. However, what happens to the lipid/polymer membrane during MSG preconditioning is not clear. Therefore, we carried out three experiments to investigate the changes in the lipid/polymer membrane caused by the MSG preconditioning, i.e., measurements of the taste sensor, measurements of the amount of the bitterness substance adsorbed onto the membrane and measurements of the contact angle of the membrane surface. The CPA values increased as the preconditioning process progressed, and became stable after 3 d of preconditioning. The response potentials to the reference solution showed the same tendency of the CPA value change during the preconditioning period. The contact angle of the lipid/polymer membrane surface decreased after 7 d of MSG preconditioning; in short, the surface of the lipid/polymer membrane became hydrophilic during MSG preconditioning. The amount of adsorbed iso-alpha acid was increased until 5 d preconditioning, and then it decreased. In this study, we revealed that the CPA values increased with the progress of MSG preconditioning in spite of the decrease of the amount of iso-alpha acid adsorbed onto the lipid/polymer membrane, and it was indicated that the CPA values increase because the sensor sensitivity was improved by the MSG preconditioning.

  1. Fuel cells for electricity generation from carbonaceous fuels

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-09-01

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

  2. Functionalized polymer nanofibre membranes for protection from chemical warfare stimulants

    International Nuclear Information System (INIS)

    Ramaseshan, Ramakrishnan; Sundarrajan, Subramanian; Liu, Yingjun; Barhate, R S; Lala, Neeta L; Ramakrishna, S

    2006-01-01

    A catalyst for the detoxification of nerve agents is synthesized from β-cyclodextrin (β-CD) and o-iodosobenzoic acid (IBA). Functionalized polymer nanofibre membranes from PVC polymer are fabricated with β-CD, IBA, a blend of β-CD+IBA, and the synthesized catalyst. These functionalized nanofibres are then tested for the decontamination of paraoxon, a nerve agent stimulant, and it is observed that the stimulant gets hydrolysed. The kinetics of hydrolysis is investigated using UV spectroscopy. The rates of hydrolysis for different organophosphate hydrolyzing agents are compared. The reactivity and amount of adsorption of these catalysts are of higher capacity than the conventionally used activated charcoal. A new design for protective wear is proposed based on the functionalized nanofibre membrane

  3. Functionalized polymer nanofibre membranes for protection from chemical warfare stimulants

    Science.gov (United States)

    Ramaseshan, Ramakrishnan; Sundarrajan, Subramanian; Liu, Yingjun; Barhate, R. S.; Lala, Neeta L.; Ramakrishna, S.

    2006-06-01

    A catalyst for the detoxification of nerve agents is synthesized from β-cyclodextrin (β-CD) and o-iodosobenzoic acid (IBA). Functionalized polymer nanofibre membranes from PVC polymer are fabricated with β-CD, IBA, a blend of β-CD+IBA, and the synthesized catalyst. These functionalized nanofibres are then tested for the decontamination of paraoxon, a nerve agent stimulant, and it is observed that the stimulant gets hydrolysed. The kinetics of hydrolysis is investigated using UV spectroscopy. The rates of hydrolysis for different organophosphate hydrolyzing agents are compared. The reactivity and amount of adsorption of these catalysts are of higher capacity than the conventionally used activated charcoal. A new design for protective wear is proposed based on the functionalized nanofibre membrane.

  4. Functionalized polymer nanofibre membranes for protection from chemical warfare stimulants

    Energy Technology Data Exchange (ETDEWEB)

    Ramaseshan, Ramakrishnan [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576, Singapore (Singapore); Sundarrajan, Subramanian [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576, Singapore (Singapore); Liu, Yingjun [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore (Singapore); Barhate, R S [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576, Singapore (Singapore); Lala, Neeta L [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576, Singapore (Singapore); Ramakrishna, S [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576, Singapore (Singapore)

    2006-06-28

    A catalyst for the detoxification of nerve agents is synthesized from {beta}-cyclodextrin ({beta}-CD) and o-iodosobenzoic acid (IBA). Functionalized polymer nanofibre membranes from PVC polymer are fabricated with {beta}-CD, IBA, a blend of {beta}-CD+IBA, and the synthesized catalyst. These functionalized nanofibres are then tested for the decontamination of paraoxon, a nerve agent stimulant, and it is observed that the stimulant gets hydrolysed. The kinetics of hydrolysis is investigated using UV spectroscopy. The rates of hydrolysis for different organophosphate hydrolyzing agents are compared. The reactivity and amount of adsorption of these catalysts are of higher capacity than the conventionally used activated charcoal. A new design for protective wear is proposed based on the functionalized nanofibre membrane.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

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

  6. The effect of silica toward polymer membrane for water separation process

    Science.gov (United States)

    Jamalludin, Mohd Riduan; Rosli, M. U.; Ishak, Muhammad Ikman; Khor, C. Y.; Shahrin, Suhaimi; Ismail, Ras Izzati; Lailina N., M.; Leng Y., L.; Jahidi, H.

    2017-09-01

    The aim of this present work was to investigate the effect of different percentage rice husk silica (RHS) particles composition towards polymer mixed matrix membrane microstructure and performance in water separation process. The polymer membranes were prepared by a phase inversion method using polysulfone (PSf), N-methyl-2-pyrrolidone (NMP) as solvent, distilled water as non-solvent and fixed RHS at 400°C as an additive. The microstructures of PSf/PEG/RHS sample were characterized by performing scanning electron microscope (SEM). The performance was measured by using pure water flux and humic acid for the rejection test. The analyzed result of SEM analysis revealed that the addition of RHS obviously improved the microstructure of the membrane especially at the top and sub layer at the range of 1 until 3 wt. %. This was proven by the pure water flux (PWF) value measured from 114.47 LMH to 154.04 LMH and rejection from value 83% to 96% at this specified range substantially higher than the mixed matrix membrane with synthetic silica. In fact, the presence of RHS particles not only improved the properties and performance of membrane but also possess biodegradable properties which can minimize the pollution and provide a membrane green technology system.

  7. Self-positioning of polymer membranes driven by thermomechanically induced plastic deformation

    DEFF Research Database (Denmark)

    Häfliger, Daniel; Hansen, Ole; Boisen, Anja

    2006-01-01

    Stress in polymeric resins is tailored by a thermomechanical process. It allows for controlled self-positioning of membranes in microdevices (see Figure). The process makes specific use of plastic deformation that results from the low viscosity of the polymer. This demonstrates that polymers offer...... new approaches to microfabrication that cannot be realized for common semiconductor materials without severe difficulties....

  8. Synthesis of precursor the base of indene for polyelectrolyte an membrane production for application in fuel cell; Sintese de precursores a base de indeno para producao de polieletrolitos e membranas para uso em celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Brum, F.J.B.; Laux, F.N.; Haack, M.S.; Forte, M.M.C. [Universidade Federal do Rio Grande do Sul. Escola de Engenharia, Porto Alegre, RS (Brazil)

    2010-07-01

    Monomers with vinyl bond can be polymerized via a cationic mechanism using acid catalysts. This study aimed to obtain homo and copolymers of styrene and indene via cationic mechanism and the functionalization of sulfonic groups to the production of membranes for fuel cells. Polymers and poly electrolytes were characterized by infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and gel permeation chromatography (GPC/SEC). The degree of sulfonation of the polymers was determined by titration and evaluated for these films to the degree of swelling in water, ion exchange capacity and analysis of electrochemical impedance spectroscopy. Membranes prepared with polyindene and PVA were tested in an apparatus of the fuel cell. (author)

  9. Novel Zeolitic Imidazolate Framework/Polymer Membranes for Hydrogen Separations in Coal Processing

    Energy Technology Data Exchange (ETDEWEB)

    Musselman, Inga H.

    2013-01-31

    Nanoparticles of zeolitic imidazolate frameworks and other related hybrid materials were prepared by modifying published synthesis procedures by introducing bases, changing stoichiometric ratios, or adjusting reaction conditions. These materials were stable at temperatures >300 °C and were compatible with the polymer matrices used to prepare mixed-matrix membranes (MMMs). MMMs tested at 300 °C exhibited a >30 fold increase in permeability, compared to those measured at 35 °C, while maintaining H{sub 2}/CO{sub 2} selectivity. Measurements at high pressure (up to 30 atm) and high temperature (up to 300 °C) resulted in an increase in gas flux across the membrane with retention of selectivity. No variations in permeability were observed at high pressures at either 35 or 300 °C. CO{sub 2}-induced plasticization was not observed for Matrimid®, VTEC, and PBI polymers or their MMMs at 30 atm and 300 °C. Membrane surface modification by cross-linking with ethylenediamine resulted in an increase in H{sub 2}/CO{sub 2} selectivity at 35 °C. Spectrometric analysis showed that the cross-linking was effective to temperatures <150 °C. At higher temperatures, the cross-linked membranes exhibit a H2/CO2 selectivity similar to the uncrosslinked polymer.

  10. Cell-Culture Reactor Having a Porous Organic Polymer Membrane

    Science.gov (United States)

    Koontz, Steven L. (Inventor)

    2000-01-01

    A method for making a biocompatible polymer article using a uniform atomic oxygen treatment is disclosed. The substrate may be subsequently optionally grated with a compatibilizing compound. Compatibilizing compounds may include proteins, phosphory1choline groups, platelet adhesion preventing polymers, albumin adhesion promoters, and the like. The compatibilized substrate may also have a living cell layer adhered thereto. The atomic oxygen is preferably produced by a flowing afterglow microwave discharge, wherein the substrate resides in a sidearm out of the plasma. Also, methods for culturing cells for various purposes using the various membranes are disclosed as well. Also disclosed are porous organic polymers having a distributed pore chemistry (DPC) comprising hydrophilic and hydrophobic regions, and a method for making the DPC by exposing the polymer to atomic oxygen wherein the rate of hydrophilization is greater than the rate of mass loss.

  11. New ETFE-based membrane for direct methanol fuel cell

    International Nuclear Information System (INIS)

    Saarinen, V.; Kallio, T.; Paronen, M.; Tikkanen, P.; Rauhala, E.; Kontturi, K.

    2005-01-01

    The investigated membranes are based on 35-bar μ m thick commercial poly(ethylene-alt-tetrafluoroethylene) (ETFE) films. The films were made proton conductive by means of irradiation treatment followed by sulfonation. These membranes have exceptionally low water uptake and excellent dimensional stability. The new membranes are investigated widely in a laboratory-scale direct methanol fuel cell (DMFC). The temperature range used in the fuel cell tests was 30-85-bar o C and the measurement results were compared to those of the Nafion ( R)115 membrane. Also methanol permeability through the ETFE-based membrane was measured as a function of temperature, resulting in values less than 10% of the corresponding values for Nafion ( R)115, which was considerably thicker than the experimental membrane. Methanol crossover was reported to decrease when the thickness of the membrane increases, so the ETFE-based membrane compares favourably to Nafion ( R) membranes. The maximum power densities achieved with the experimental ETFE-based membrane were about 40-65% lower than the corresponding values of the Nafion ( R)115 membrane, because of the lower conductivity and noticeably higher IR-losses. Chemical and mechanical stability of the ETFE-based membrane appeared to be promising since it was tested over 2000-bar h in the DMFC without any performance loss

  12. The defouling of membranes using polymer beads containing ...

    African Journals Online (AJOL)

    Methods of physical cleaning of the polymer membranes, which do not require the plant to be shut down for lengthy periods, are very attractive and also do not generate any waste fluids. This paper reports on an investigation into the possibility of obtaining flux enhancement during the filtration process, as well as the ...

  13. 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.

  14. Fuel cells with solid polymer electrolyte and their application on vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Fateev, V.

    1996-04-01

    In Russia, solid polymer electrolyte MF-4-SK has been developed for fuel cells. This electrolyte is based on perfluorinated polymer with functional sulfogroups. Investigations on electrolyte properties and electrocatalysts have been carried out.

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

    Science.gov (United States)

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

    2017-06-01

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

  16. Mixed hydrocarbon/fluoropolymer membrane/ionomer MEAs for durability studies

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bo [Los Alamos National Laboratory; Kim, Yu Seung [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Borup, Rodney L [Los Alamos National Laboratory; Wilson, Mahlon S [Los Alamos National Laboratory; Welch, Cynthia [Los Alamos National Laboratory; Fenton, James [FLORIDA SOLAR ENERGY CENTER

    2010-01-01

    The durability of polymer electrolyte membrane (PEM) fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. Commercial viability depends on improving the durability of the fuel cell components to increase the system reliability. The aim of this work is to separate ionomer degradation from membrane degradation via mixed membrane/ionomer MEA experiments. The challenges of mixed MEA fabrication due to the incompatibility of the membrane and the electrode are addressed. OCV accelerated testing experiment (AST) were performed. Development of in situ diagnostics and unique experiments to characterize the performance and properties of the ionomer in the electrode as a function of time is reported. These measurements, along with extensive ex situ and post-mortem characterization, can delineate the degradation mechanisms in order to develop more durable fuel cells and fuel cell components.

  17. Castor oil and commercial thermoplastic polyurethane membranes modified with polyaniline: a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Almeida Junior, Jose Humberto Santos; Meneguzzi, Alvaro; Ferreira, Carlos Arthur, E-mail: jhsajunior@globomail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegtre, RS (Brazil). Dept. de Engenharia de Materiais; Bertuol, Daniel Assumpcao [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Dept. de Engenharia Quimica; Amado, Franco Dani Rico [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil). Dept. de Ciencias Exatas e Tecnologia

    2013-11-01

    The study of conducting polymeric membranes is decisive in some areas, as in fuel cells and electrodialysis. This work aims the study of membranes using conventional and conductive polymers blends. Two types of polyurethane were used as conventional polymers, commercial thermoplastic polyurethane and polyurethane synthesized from castor oil and 4-4-dicyclohexylmethane isocyanate. Two kinds of conducting polymers were used, polyaniline doped with organic acid and a self doped polyaniline. The polymers and the membranes were characterized by electrical conductivity, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). The synthesis of the membranes produced was proper, featuring a complete reaction, analyzed by FTIR. The membranes also showed good mechanical properties and thermal stability ( Almost-Equal-To 220 Degree-Sign C). Among the membranes studied, the polyaniline doped with p-toluenesulphonic acid obtained higher thermal and viscoelastic properties. Thus they can be used in separation techniques using membranes. (author)

  18. Fuel cell electrodes: Electrochemical characterization and electrodeposition of Pt nanoparticles

    CSIR Research Space (South Africa)

    Modibedi, M

    2008-05-01

    Full Text Available Fuel Cell (PEMFC) Electrolyte: solid polymer membrane (typically Nafion) Types of fuel cells (FC) ? CSIR 2007 www.csir.co.za PEMFC http://fuelcellsworks.com/ ? CSIR 2007 www.csir.co.za Electrodes...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Joy Wei Yi Liew

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

  1. Development and testing of a hybrid system with a sub-kW open-cathode type PEM (proton exchange membrane) fuel cell stack

    International Nuclear Information System (INIS)

    Huang, Zhen-Ming; Su, Ay; Liu, Ying-Chieh

    2014-01-01

    In this study, the performance of a polymer electrolyte membrane fuel cell stack has been evaluated for a hybrid power system test platform. To simulate vehicle acceleration, the stack was operated under dynamic-loading, and to demonstrate the exchange of power flow between two power sources the hybrid power system was tested under three different modes. A unit cell was fabricated for high stack performance and the stack was constructed with 18 open-cathode type fuel cells. Air which acts as a coolant as well as an oxidant for electrochemical reactions is provided by a pair of fans. The capabilities of the stack for hybrid power system test platform were validated by successful dynamic-loading tests. The performance of the stack for various air fan voltage was evaluated and an optimal value was concluded. The conditions like inlet temperature of H 2 and the stack current were established for maximum power. It was also found that humidification of hydrogen at anode inlet degrades the stack performance and stability due to flooding. Evidence shows that for the higher overall performance, the fuel cell acts continuously on constant current output. The study contributes to the design of mobility hybrid system to get better performance and reliability. - Highlights: • An open-cathode type PEMFC (polymer electrolyte membrane fuel cell) stack (rated output 300 W) was fabricated. • The open-cathode configuration simplifies the design of a stack system. • Assess the feasibility of combining a fuel cell stack in a hybrid system. • The study contributes to the design of mobility hybrid system to get better performance and reliability

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

    Science.gov (United States)

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

    2015-02-24

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

  3. Quantitative characterization of water transport and flooding in the diffusion layers of polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Casalegno, A.; Colombo, L.; Galbiati, S.; Marchesi, R. [Department of Energy, Politecnico di Milano, via Lambruschini 4, 20156 Milano (Italy)

    2010-07-01

    Optimization of water management in polymer electrolyte membrane fuel cells (PEMFC) and in direct methanol fuel cells (DMFC) is a very important factor for the achievement of high performances and long lifetime. A good hydration of the electrolyte membrane is essential for high proton conductivity; on the contrary water in excess may lead to electrode flooding and severe reduction in performances. Many studies on water transport across the gas diffusion layer (GDL) have been carried out to improve these components; anyway efforts in this field are affected by lack of effective experimental methods. The present work reports an experimental investigation with the purpose to determine the global coefficient of water transport across different diffusion layers under real operating conditions. An appropriate and accurate experimental apparatus has been designed and built to test the single GDL under a wide range of operating conditions. Data analysis has allowed quantification of both the water vapor transport across different diffusion layers, and the effects of micro-porous layers; furthermore flooding onset and its consequences on the mass transport coefficient have been characterized by means of suitably defined parameters. (author)

  4. Incorporating Graphene Oxide into Alginate Polymer with a Cationic Intermediate To Strengthen Membrane Dehydration Performance.

    Science.gov (United States)

    Guan, Kecheng; Liang, Feng; Zhu, Haipeng; Zhao, Jing; Jin, Wanqin

    2018-04-25

    Two-dimensional graphene oxide (GO) in hybrid membranes provides fast water transfer across its surface due to the abundant oxygenated functional groups to afford water sorption and the hydrophobic basal plane to create fast transporting pathways. To establish more compatible and efficient interactions for GO and sodium alginate (SA) polymer chains, cations sourced from lignin are employed to decorate GO (labeled as cation-functionalized GO (CG)) nanosheets via cation-π and π-π interactions, providing more interactive sites to confer synergetic benefits with polymer matrix. Cations from CG are also functional to partially interlock SA chains and intensify water diffusion. And with the aid of two-dimensional pathways of CG, fast selective water permeation can be realized through hybrid membranes with CG fillers. In dehydrating aqueous ethanol solution, the hybrid membrane exhibits considerable performance compared with bare SA polymer membrane (long-term stable permeation flux larger than 2500 g m -2 h -1 and water content larger than 99.7 wt %, with feed water content of 10 wt % under 70 °C). The effects of CG content in SA membrane were investigated, and the transport mechanism was correspondingly studied through varying operation conditions and membrane materials. In addition, such a membrane possesses long-term stability and almost unchanged high dehydration capability.

  5. Materials comprising polydienes and hydrophilic polymers and related methods

    Science.gov (United States)

    Mays, Jimmy W [Knoxville, TN; Deng, Suxiang [Knoxville, TN; Mauritz, Kenneth A [Hattiesburg, MS; Hassan, Mohammad K [Hattiesburg, MS; Gido, Samuel P [Hadley, MA

    2011-11-22

    Materials prepared from polydienes, such as poly(cyclohexadiene), and hydrophilic polymers, such as poly(alkylene oxide), are described. Methods of making the materials and their use in fuel cell membranes, batteries, breathable chemical-biological protective materials, and templates for sol-gel polymerization are also provided. The materials can be crosslinked and sulfonated, and can include copolymers and polymer blends.

  6. Pyro-electrification of polymer membranes for cell patterning

    Energy Technology Data Exchange (ETDEWEB)

    Rega, R.; Gennari, O.; Mecozzia, L.; Grilli, S.; Pagliarulo, V.; Ferraro, P. [National Council of Research, Institute of Applied Science & Intelligent Systems (ISASI) ‘E. Caianiello’, Via Campi Flegrei 34, 80078 Pozzuoli (Italy)

    2016-05-18

    In the recent years, much attention has been devoted to the possibility of charging polymer-based materials, due to their potential in developing large-scale and inexpensive flexible thin-film technology. The availability of localized electrostatic fields is in of great interest for a huge amount of applications such as distribution of biomolecules and cells from the liquid phase. Here we report a voltage-free pyro-electrification (PE) process able to induce permanent dipoles into polymer layers; the lithium niobate (LN) crystal is the key component that plays the multi-purpose role of sustaining, heating and poling the polymer layer that is then peeled-off easily in order to have a free-standing charged membrane. The results show the fascinating application for the living cell patterning. It well known that cell behaviour is affected by chemical and topographical cues of substrate. In fact, polymers, such as polystyrene (PS) and poly(methyl methacrylate) (PMMA), are naturally cytophobic and require specific functionalization treatments in order to promote cell adhesion. Through our proposal technique, it’s possible to obtain spontaneous organization and a driven growth of SH-SY5Y cells that is solely dictated by the nature of the charge polymer surface, opening, in this way, the innovative chance to manipulate and transfer biological samples on a free-standing polymer layer [1].

  7. Influence of radiation-induced grafting process on mechanical properties of ETFE-based membranes for fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ben Youcef, H.; Alkan Guersel, S.; Buisson, A.; Gubler, L.; Wokaun, A.; Scherer, G.G. [Electrochemistry Laboratory, Paul Scherrer Institut, Villigen PSI (Switzerland)

    2010-06-15

    The mechanical stability is, in addition to thermal and chemical stability, a primary requirement of polymer electrolyte membranes in fuel cells. In this study, the impact of grafting parameters and preparation steps on stress-strain properties of ETFE-based proton conducting membranes, prepared by radiation-induced grafting and subsequent sulphonation, was studied. No significant change in the mechanical properties of the ETFE base film was observed below an irradiation dose of 50 kGy. It was shown that the elongation at break decreases with increasing both the crosslinker concentration and graft level (GL). However, the tensile strength was positively affected by the crosslinker concentration. Yield strength and modulus of elasticity are almost unaffected by the introduction of crosslinker. Interestingly, yield strength and modulus of elasticity increase gradually with GL without noticeable change of the inherent crystallinity of grafted films. The most brittle membranes are obtained via the combination of high GL and crosslinker concentration. The optimised ETFE-based membrane (GL of {proportional_to}25%, 5% DVB v/v), shows mechanical properties superior to those of Nafion registered 112 membrane. The obtained results were correlated qualitatively to the other ex situ properties, including crystallinity, thermal properties and water uptake of the grafted membranes. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  8. Innovative membrane development for fuel cells

    CSIR Research Space (South Africa)

    Vaivars, G

    2011-10-01

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

  9. CO tolerance of polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-08-01

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

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

    DEFF Research Database (Denmark)

    Rabbani, Raja Abid; Rokni, Masoud

    2013-01-01

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

  11. Membrane reactor technology for ultrapure hydrogen production

    NARCIS (Netherlands)

    Patil, Charudatta Subhash

    2005-01-01

    The suitability of polymer electrolyte membrane fuel cells (PEMFC) for stationary and vehicular applications because of its low operating temperatures, compactness, higher power density, cleaner exhausts and higher efficiencies compared to conventional internal combustion engines and gas turbines

  12. 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.

  13. Helium Ion Microscopy of proton exchange membrane fuel cell electrode structures

    Directory of Open Access Journals (Sweden)

    Serguei Chiriaev

    2017-12-01

    Full Text Available Characterization of composite materials with microscopy techniques is an essential route to understanding their properties and degradation mechanisms, though the observation with a suitable type of microscopy is not always possible. In this work, we present proton exchange membrane fuel cell electrode interface structure dependence on ionomer content, systematically studied by Helium Ion Microscopy (HIM. A special focus was on acquiring high resolution images of the electrode structure and avoiding interface damage from irradiation and tedious sample preparation. HIM demonstrated its advantages in surface imaging, which is paramount in studies of the interface morphology of ionomer covered or absorbed catalyst structures in a combination with electrochemical characterization and accelerated stress test. The electrode porosity was found to depend on the ionomer content. The stressed electrodes demonstrated higher porosity in comparison to the unstressed ones on the condition of no external mechanical pressure. Moreover, formation of additional small grains was observed for the electrodes with the low ionomer content, indicating Pt redeposition through Ostwald ripening. Polymer nanofiber structures were found in the crack regions of the catalyst layer, which appear due to the internal stress originated from the solvent evaporation. These fibers have fairly uniform diameters of a few tens of nanometers, and their density increases with the increasing ionomer content in the electrodes. In the hot-pressed electrodes, we found more closed contact between the electrode components, reduced particle size, polymer coalescence and formation of nano-sized polymer fiber architecture between the particles.

  14. 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.

  15. Nanostructured Block Polymer Membranes as High Capacity Adsorbers for the Capture of Metal Ions from Water

    Science.gov (United States)

    Boudouris, Bryan; Weidman, Jacob; Mulvenna, Ryan; Phillip, William

    The efficient removal of metal ions from aqueous streams is of significant import in applications ranging from industrial waste treatment to the purification of drinking water. An emerging paradigm associated with this separation is one that utilizes membrane adsorbers as a means by which to bind metal salt contaminants. Here, we demonstrate that the casting of an A-B-C triblock polymer using the self-assembly and non-solvent induced phase separation (SNIPS) methodology results in a nanoporous membrane geometry. The nature of the triblock polymer affords an extremely high density of binding sites within the membrane. As such, we demonstrate that the membranes with binding capacities equal to that of state-of-the-art packed bed columns. Moreover, because the affinity of the C moiety can be tuned, highly selective binding events can occur based solely on the chemistry of the block polymer and the metal ions in solution (i.e., in a manner that is independent of the size of the metal ions). Due to these combined facts, these membranes efficiently remove heavy metal (e.g., lead- and cadmium-based) salts from contaminated water streams with greater than 95% efficiency. Finally, we show that the membranes can be regenerated through a simple treatment in order to provide long-lasting adsorber systems as well. Thus, it is anticipated that these nanostructured triblock polymer membranes are a platform by which to obtain next-generation water purification processes.

  16. Poly (fluorenyl ether ketone) ionomers containing separated hydrophilic multiblocks used in fuel cells as proton exchange membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hu, H.; Xiao, M.; Wang, S.J.; Meng, Y.Z. [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275 (China); The Key Laboratory of Low-carbon Chemistry and Energy Conservation of Guangdong Province, Sun Yat-Sen University, Guangzhou 510275 (China)

    2010-01-15

    A series of sulfonated poly(fluorenyl ether ketone) with different hydrophilic block lengths were synthesized via a two-step one-pot polymerization from 9,9'-bis(4-Hydroxypheyl) fluorine, 3,3'-disulfonated-4,4'-difluorobenzophenone, and 4,4'-difluorobenzophenone. The resulting sulfonated block polymers with high inherent viscosity (0.8-1.37 dL/g) were very soluble in polar organic solvents and can form flexible and transparent membranes by casting from their solutions. Transmission electron microscope (TEM) was used to examine the microstructure of the membranes and the results revealed that significant hydrophilic/hydrophobic microphase separation was produced. The effects of the multiblock structure and/or length were investigated by comparison of the properties of the multiblock copolymer and the corresponding random structure. The multiblock structure can provide enhanced proton transport, especially under partially hydrated conditions. The as-made membranes can also exhibit better oxidative stability and single cell performance than random copolymer. The multiblock structure design method provides a useful way to prepare proton exchange membrane used in PEM fuel cells. (author)

  17. Fuel cell subassemblies incorporating subgasketed thrifted membranes

    Science.gov (United States)

    Iverson, Eric J.; Pierpont, Daniel M.; Yandrasits, Michael A.; Hamrock, Steven J.; Obradovich, Stephan J.; Peterson, Donald G.

    2016-03-01

    A fuel cell roll good subassembly is described that includes a plurality of individual electrolyte membranes. One or more first subgaskets are attached to the individual electrolyte membranes. Each of the first subgaskets has at least one aperture and the first subgaskets are arranged so the center regions of the individual electrolyte membranes are exposed through the apertures of the first subgaskets. A second subgasket comprises a web having a plurality of apertures. The second subgasket web is attached to the one or more first subgaskets so the center regions of the individual electrolyte membranes are exposed through the apertures of the second subgasket web. The second subgasket web may have little or no adhesive on the subgasket surface facing the electrolyte membrane.

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  19. Analysis of proton exchange membrane fuel cell performance with alternate membranes

    Energy Technology Data Exchange (ETDEWEB)

    Wakizoe, Masanobu; Velev, O A; Srinivasan, S [Texas A and M Univ., College Station, TX (United States). Texas Engineering Experiment Station

    1995-02-01

    Renewed interest in proton exchange membrane fuel cell technology for space and terrestrial (particularly electric vehicles) was stimulated by the demonstration, in the mid 1980s, of high energy efficiencies and high power densities. One of the most vital components of the PEMFC is the proton conducting membrane. In this paper, an analysis is made of the performances of PEMFCs with Dupont`s Nafion, Dow`s experimental, and Asahi Chemical`s Aciplex-S membranes. Attempts were also made to draw correlations between the PEMFC performances with the three types of membranes and their physico-chemical characteristics. Practically identical levels of performances (energy efficiency, power density, and lifetime) were achieved in PEMFCs with the Dow and the Aciplex-S membranes and these performances were better than in the PEMFCs with the Nafion-115 membrane. The electrode kinetic parameters for oxygen reduction are better for the PEMFCs with the Aciplex-S and Nafion membranes than with the Dow membranes. The PEMFCs with the Aciplex-S and Dow membranes have nearly the same internal resistances which are considerably lower than for the PEMFC with the Nafion membrane. The desired membrane characteristics to obtain high levels of performance are low equivalent weight and high water content. (Author)

  20. High Temperature Polymer Electrolyte Fuel Cells

    DEFF Research Database (Denmark)

    Fleige, Michael

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

  1. Gas Separation Membranes Derived from High-Performance Immiscible Polymer Blends Compatibilized with Small Molecules.

    Science.gov (United States)

    Panapitiya, Nimanka P; Wijenayake, Sumudu N; Nguyen, Do D; Huang, Yu; Musselman, Inga H; Balkus, Kenneth J; Ferraris, John P

    2015-08-26

    An immiscible polymer blend comprised of high-performance copolyimide 6FDA-DAM:DABA(3:2) (6FDD) and polybenzimidazole (PBI) was compatibilized using 2-methylimidazole (2-MI), a commercially available small molecule. Membranes were fabricated from blends of 6FDD:PBI (50:50) with and without 2-MI for H2/CO2 separations. The membranes demonstrated a matrix-droplet type microstructure as evident with scanning electron microscopy (SEM) imaging where 6FDD is the dispersed phase and PBI is the continuous phase. In addition, membranes with 2-MI demonstrated a uniform microstructure as observed by smaller and more uniformly dispersed 6FDD domains in contrast to 6FDD:PBI (50:50) blend membranes without 2-MI. This compatibilization effect of 2-MI was attributed to interfacial localization of 2-MI that lowers the interfacial energy similar to a surfactant. Upon the incorporation of 2-MI, the H2/CO2 selectivity improved remarkably, compared to the pure blend, and surpassed the Robeson's upper bound. To our knowledge, this is the first report of the use of a small molecule to compatibilize a high-performance immiscible polymer blend. This approach could afford a novel class of membranes in which immiscible polymer blends can be compatibilized in an economical and convenient fashion.

  2. HIGH PERMEABILITY MEMBRANES FOR THE DEHYDRATION OF LOW WATER CONTENT ETHANOL BY PERVAPORATION

    Science.gov (United States)

    Energy efficient dehydration of low water content ethanol is a challenge for the sustainable production of fuel-grade ethanol. Pervaporative membrane dehydration using a recently developed hydrophilic polymer membrane formulation consisting of a cross-linked mixture of poly(allyl...

  3. Synthesis of protons exchange polymeric membranes via co-poly-esters doped with sodium dodecyl sulfate for application in PEM fuel cells; Sintese de membranas polimericas condutoras de protons por imobilizacao de MDs em copoliesteres para aplicacao em PEM-FC

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, R.A.; Brioude, M.M.; Bresciani, D.; Jose, N.M.; Boaventura, J.S. [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica

    2008-07-01

    Polymers are largely studied for use in PEM-type fuel cell (Proton Exchange membrane, PEMFC). These fuel cells are based on polymer membranes as electrolyte, also called protons conductor. This work developed co-polyesters made electrical conductors by doping with sodium dodecyl sulfate. The copolymers were synthesized from the copolymerization of terephthalic and adipic acids with glycerol. The material was processed in a reactor and shaped by hot pressing, yielding homogeneous and flexible plates, with excellent surface finish. The co-polyesters were analyzed by SEM, FTIR, TG, DSC, and XRD. The thermal analysis showed that the composites were thermally stable up to about 250 deg C. The micrographics revealed the MDS homogeneously dispersed in the polymeric matrix. These copolymers showed electrical conductivity between 10-7 to 10-1 S/cm, suggesting strong potential use in PEM fuel cells. (author)

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

    International Nuclear Information System (INIS)

    Perna, Alessandra; Minutillo, Mariagiovanna; Jannelli, Elio

    2015-01-01

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

  5. DEVELOPMENT AND CHARACTERIZATION OF POLYVINYLIDENE FLUORIDE - IMIDAZOLIUM FUNCTIONALIZED POLYSULFONE BLEND ANION EXCHANGE MEMBRANE

    Directory of Open Access Journals (Sweden)

    S. VELU

    2015-09-01

    Full Text Available Anion exchange membrane (AEM is one of the core components of an alkaline fuel cell influencing the fuel cell’s performance, durability and stability. Out of the many anion exchange membranes reported so far, imidazolium functionalized polysulfone (PSf-ImOH membrane has been identified to have high hydroxide ionic conductivity, reaching up to 50 mS cm-1 at 20oC. However, at high levels of ion exchange capacity, the membrane’s water uptake and swelling ratio increases significantly with temperature thus destabilizing it and making it unfit for potential use in high temperature alkaline fuel cells. This limitation of PSf-ImOH membranes has been overcome by blending it with polyvinylidene fluoride (PVDF polymer, which is a thermally stable and highly hydrophobic polymer. PSf-ImOH membrane with a high degree of chloromethylation (180% was synthesized and blended with PVDF at different weight ratios (PVDF / PSf-ImOH: 30/70, 50/50 and 70/30 to create a series of novel anion exchange membranes. The prepared membranes were characterized to study their structure, water uptake, swelling ratio, solubility in low boiling water soluble solvents, thermal stability, ion exchange capacity (IEC and ionic conductivity (IC at different temperatures. The 70% PVDF blend membrane demonstrated the better performance in terms of IEC, IC and water uptake properties compared to other membranes. Comparative studies on the water uptake and IC variation between the 70% PVDF blend membrane and pure PSfImOH membrane (having the same IEC as that of the blend membrane, clearly indicated the superiority and the promising use of the blend membrane in alkaline fuel cell especially for high temperature working condition.

  6. Long term testing of PSI-membranes

    Energy Technology Data Exchange (ETDEWEB)

    Huslage, J; Brack, H P; Geiger, F; Buechi, F N; Tsukada, A; Scherer, G G [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Long term tests of PSI membranes based on radiation-grafted FEP and ETFE films were carried out and FEP-based membranes were evaluated by monitoring the in-situ membrane area resistance measured by a current pulse method. By modifying our irradiation procedure and using the double crosslinking concept we obtain reproducible membrane cell lifetimes (in term of in-situ membrane resistance) of greater than 5000 hours at 60-65{sup o}C. Preliminary tests at 80-85{sup o}C with lifetimes of greater than 2500 demonstrate the potential long term stability of PSI proton exchange membranes based on FEP over the whole operating temperature range of low-temperature polymer electrolyte fuel cells. Radiation grafted PSI membranes based on ETFE have better mechanical properties than those of the FEP membranes. Mechanical properties are particularly important in large area cells and fuel cell stacks. ETFE membranes have been tested successfully for approximately 1000 h in a 2-cell stack (100 cm{sup 2} active area each cell). (author) 4 figs., 4 refs.

  7. Low-temperature fuel cells operating with contaminated feedstock

    NARCIS (Netherlands)

    Wingelaar, P.J.H.

    2007-01-01

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

  8. The role of polymer nanolayer architecture on the separation performance of anion-exchange membrane adsorbers: I. Protein separations.

    Science.gov (United States)

    Bhut, Bharat V; Weaver, Justin; Carter, Andrew R; Wickramasinghe, S Ranil; Husson, Scott M

    2011-11-01

    This contribution describes the preparation of strong anion-exchange membranes with higher protein binding capacities than the best commercial resins. Quaternary amine (Q-type) anion-exchange membranes were prepared by grafting polyelectrolyte nanolayers from the surfaces of macroporous membrane supports. A focus of this study was to better understand the role of polymer nanolayer architecture on protein binding. Membranes were prepared with different polymer chain graft densities using a newly developed surface-initiated polymerization protocol designed to provide uniform and variable chain spacing. Bovine serum albumin and immunoglobulin G were used to measure binding capacities of proteins with different size. Dynamic binding capacities of IgG were measured to evaluate the impact of polymer chain density on the accessibility of large size protein to binding sites within the polyelectrolyte nanolayer under flow conditions. The dynamic binding capacity of IgG increased nearly linearly with increasing polymer chain density, which suggests that the spacing between polymer chains is sufficient for IgG to access binding sites all along the grafted polymer chains. Furthermore, the high dynamic binding capacity of IgG (>130 mg/mL) was independent of linear flow velocity, which suggests that the mass transfer of IgG molecules to the binding sites occurs primarily via convection. Overall, this research provides clear evidence that the dynamic binding capacities of large biologics can be higher for well-designed macroporous membrane adsorbers than commercial membrane or resin ion-exchange products. Specifically, using controlled polymerization leads to anion-exchange membrane adsorbers with high binding capacities that are independent of flow rate, enabling high throughput. Results of this work should help to accelerate the broader implementation of membrane adsorbers in bioprocess purification steps. Copyright © 2011 Wiley Periodicals, Inc.

  9. Inorganic-based proton conductive composite membranes for elevated temperature and reduced relative humidity PEM fuel cells

    Science.gov (United States)

    Wang, Chunmei

    Proton exchange membrane (PEM) fuel cells are regarded as highly promising energy conversion systems for future transportation and stationary power generation and have been under intensive investigations for the last decade. Unfortunately, cutting edge PEM fuel cell design and components still do not allow economically commercial implementation of this technology. The main obstacles are high cost of proton conductive membranes, low-proton conductivity at low relative humidity (RH), and dehydration and degradation of polymer membranes at high temperatures. The objective of this study was to develop a systematic approach to design a high proton conductive composite membrane that can provide a conductivity of approximately 100 mS cm-1 under hot and dry conditions (120°C and 50% RH). The approach was based on fundamental and experimental studies of the proton conductivity of inorganic additives and composite membranes. We synthesized and investigated a variety of organic-inorganic Nafion-based composite membranes. In particular, we analyzed their fundamental properties, which included thermal stability, morphology, the interaction between inorganic network and Nafion clusters, and the effect of inorganic phase on the membrane conductivity. A wide range of inorganic materials was studied in advance in order to select the proton conductive inorganic additives for composite membranes. We developed a conductivity measurement method, with which the proton conductivity characteristics of solid acid materials, zirconium phosphates, sulfated zirconia (S-ZrO2), phosphosilicate gels, and Santa Barbara Amorphous silica (SBA-15) were discussed in detail. Composite membranes containing Nafion and different amounts of functionalized inorganic additives (sulfated inorganics such as S-ZrO2, SBA-15, Mobil Composition of Matter MCM-41, and S-SiO2, and phosphonated inorganic P-SiO2) were synthesized with different methods. We incorporated inorganic particles within Nafion clusters

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    DEFF Research Database (Denmark)

    Miao, Ruiying; Liu, Bowen; Zhu, Zhongzheng

    2008-01-01

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

  12. Novel materials for fuel cells operating on liquid fuels

    Directory of Open Access Journals (Sweden)

    César A. C. Sequeira

    2017-05-01

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

  13. 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 was prepared. The alkali doped poly(2,5-benzimidazole) membrane is a promising candidate as anion exchange membrane for fuel cell application. The alkali doped poly(2,5-benzimidazole) membrane reached an anion conductivity of 2.3×10-2 S cm-1 at room temperature...

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

    Science.gov (United States)

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

    2014-09-24

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

  15. 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...

  16. Etched ion track polymer membranes for sustained drug delivery

    International Nuclear Information System (INIS)

    Rao, Vijayalakshmi; Amar, J.V.; Avasthi, D.K.; Narayana Charyulu, R.

    2003-01-01

    The method of track etching has been successfully used for the production of polymer membranes with capillary pores. In the present paper, micropore membranes have been prepared by swift heavy ion irradiation of polycarbonate (PC). PC films were irradiated with ions of gold, silicon and oxygen of varying energies and fluence. The ion tracks thus obtained were etched chemically for various time intervals to get pores and these etched films were used as membranes for the drug release. Ciprofloxacine hydrochloride was used as model drug for the release studies. The drug content was estimated spectrophotometrically. Pore size and thus the drug release is dependent on the etching conditions, ions used, their energy and fluence. Sustained drug release has been observed in these membranes. The films can be selected for practical utilization by optimizing the irradiation and etching conditions. These films can be used as transdermal patches after medical treatment

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-01-01

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

  18. Crosslinked Hexafluoropropylidene Polybenzimidazole Membranes with Chloromethyl Polysulfone for Fuel Cell Applications

    DEFF Research Database (Denmark)

    Yang, Jingshuai; Li, Qingfeng; Cleemann, Lars Nilausen

    2013-01-01

    Hexafluoropropylidene polybenzimidazole (F6PBI) was synthesized with excellent chemical stability and improved solubility. When doped with phosphoric acid, however, the F6PBI membranes showed plastic deformation at elevated temperatures. Further efforts were made to covalently crosslink F6PBI...... membranes with chloromethyl polysulfone as a polymeric crosslinker. Comparing with linear F6PBI and mPBI membranes, the polymer crosslinked F6PBI membranes exhibited little organo solubility, excellent stability towards the radical oxidation, high resistance to swelling in concentrated phosphoric acid...... with the linear F6PBI and mPBI membranes....

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-30

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

  20. Analysis of a Lipid/Polymer Membrane for Bitterness Sensing with a Preconditioning Process

    Directory of Open Access Journals (Sweden)

    Rui Yatabe

    2015-09-01

    Full Text Available It is possible to evaluate the taste of foods or medicines using a taste sensor. The taste sensor converts information on taste into an electrical signal using several lipid/polymer membranes. A lipid/polymer membrane for bitterness sensing can evaluate aftertaste after immersion in monosodium glutamate (MSG, which is called “preconditioning”. However, we have not yet analyzed the change in the surface structure of the membrane as a result of preconditioning. Thus, we analyzed the change in the surface by performing contact angle and surface zeta potential measurements, Fourier transform infrared spectroscopy (FTIR, X-ray photon spectroscopy (XPS and gas cluster ion beam time-of-flight secondary ion mass spectrometry (GCIB-TOF-SIMS. After preconditioning, the concentrations of MSG and tetradodecylammonium bromide (TDAB, contained in the lipid membrane were found to be higher in the surface region than in the bulk region. The effect of preconditioning was revealed by the above analysis methods.

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

    Science.gov (United States)

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

    2016-03-01

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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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