The Experts below are selected from a list of 2481 Experts worldwide ranked by ideXlab platform
S V Myakin - One of the best experts on this subject based on the ideXlab platform.
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polymer Membranes for fuel cells manufacture structure modification properties
Russian Chemical Reviews, 2010Co-Authors: Sergei S Ivanchev, S V MyakinAbstract:The state of the art in the field of synthesis, structural modification and practical use of polymer Membranes for fuel cells is analyzed. Synthetic methods, physicochemical characteristics and specific features of their composition, microphase separation and the structure of water ionic channels are considered for different types of proton-conducting materials together with the approaches to enhancement of their operational characteristics. Attention is focused on Nafion and other Fluorinated polymers as the materials that occupy the leading position as regards the design level and the broad use in small sized fuel cells. The newest developments in the field of alternative non-Fluorinated Membrane materials are also discussed, particularly, polycondensation polymer systems and hybrid organic-inorganic polymers.
Jochen Kerres - One of the best experts on this subject based on the ideXlab platform.
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stability of acid excess acid base blend Membranes in all vanadium redox flow batteries
Journal of Membrane Science, 2015Co-Authors: Andreas Chromik, Antonio Dos R Santos, Thomas Turek, Ulrich Kunz, Thomas Haring, Jochen KerresAbstract:Abstract In this contribution the performance of two acid–base blend Membranes in an all-vanadium redox-flow battery (VRFB) is studied. The first Membrane is a nonFluorinated acid–base blend Membrane composed of a sulfonated poly(arylene ether sulfone) and polybenzimidazole PBIOO, the second, partially Fluorinated, Membrane is composed of a sulfonated polymer from decafluorobiphenyl and bisphenol AF and the polybenzimidazole F6PBI. It turns out from gel permeation chromatography experiments that the molecular weight of both Membranes degrades in VRFB. However it is found that the partially Fluorinated Membrane (S1B1) is more stable in VRFB, which can be seen in the number of charge/discharge cycles, while the nonFluorinated Membrane S2B2 fails after 137 cycles, the partially Fluorinated Membrane S1B1 survives 200 cycles. Moreover, the percentage of residual molecular weight of the nonFluorinated Membrane after failure (after 137 cycles) is 34.0%, and of the partially Fluorinated Membrane (after 200 cycles) is 58.8%, respectively. Both Membranes show better peak power densities than a Nafion®117 Membrane operated in VRFB under the same conditions. In contrast to Nafion®117 and S2B2, the S1B1 Membrane shows stable voltage and energy efficiency within the first 60 charge/discharge cycles. Moreover, the Coulomb efficiency of the S1B1 Membrane was higher than that of S2B2 and Nafion®117, respectively, being nearly 100%.
Sergei S Ivanchev - One of the best experts on this subject based on the ideXlab platform.
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polymer Membranes for fuel cells manufacture structure modification properties
Russian Chemical Reviews, 2010Co-Authors: Sergei S Ivanchev, S V MyakinAbstract:The state of the art in the field of synthesis, structural modification and practical use of polymer Membranes for fuel cells is analyzed. Synthetic methods, physicochemical characteristics and specific features of their composition, microphase separation and the structure of water ionic channels are considered for different types of proton-conducting materials together with the approaches to enhancement of their operational characteristics. Attention is focused on Nafion and other Fluorinated polymers as the materials that occupy the leading position as regards the design level and the broad use in small sized fuel cells. The newest developments in the field of alternative non-Fluorinated Membrane materials are also discussed, particularly, polycondensation polymer systems and hybrid organic-inorganic polymers.
Abdul-ghani Olabi - One of the best experts on this subject based on the ideXlab platform.
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Fuel cell Membranes – Pros and cons
Energy, 2019Co-Authors: Emmanuel Ogungbemi, Mohamad Ramadan, Tabbi Wilberforce, Zaki El Hassan, Oluwatosin Ijaodola, F N Khatib, James Thompson, Abdul-ghani OlabiAbstract:Abstract This investigation provides a critical analysis of the development of PEM fuel cells and related research with specific focus on the Membrane material. The catalytic Membrane is the most important component of the PEMFC giving rise to the need for the use of efficient, durable and cheap material to reduce the overall cost of the fuel cell. In this work, the need for materials other than Nafion to be used as PEM Membranes is established and a case for the use of composite Membranes material in fuel cells is made. Composite Membranes increase the cell voltage by up to 11% even at high cell operating temperature of 95 °C. They also increase the overall performance of the cell by up to 17% when dry hydrogen is utilised. Non-Fluorinated Membranes are also suitable for use in fuel cells for portable applications but they are very expensive and less conductive. Partially Fluorinated Membranes have good mechanical stability but expensive. The Fluorinated Membrane has high stability under oxidation and reduction conditions. Unfortunately, they only reach their optimum performance at temperatures below 100 °C which makes them of limited use in PEM fuel cells application at higher temperatures.
Andreas Chromik - One of the best experts on this subject based on the ideXlab platform.
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stability of acid excess acid base blend Membranes in all vanadium redox flow batteries
Journal of Membrane Science, 2015Co-Authors: Andreas Chromik, Antonio Dos R Santos, Thomas Turek, Ulrich Kunz, Thomas Haring, Jochen KerresAbstract:Abstract In this contribution the performance of two acid–base blend Membranes in an all-vanadium redox-flow battery (VRFB) is studied. The first Membrane is a nonFluorinated acid–base blend Membrane composed of a sulfonated poly(arylene ether sulfone) and polybenzimidazole PBIOO, the second, partially Fluorinated, Membrane is composed of a sulfonated polymer from decafluorobiphenyl and bisphenol AF and the polybenzimidazole F6PBI. It turns out from gel permeation chromatography experiments that the molecular weight of both Membranes degrades in VRFB. However it is found that the partially Fluorinated Membrane (S1B1) is more stable in VRFB, which can be seen in the number of charge/discharge cycles, while the nonFluorinated Membrane S2B2 fails after 137 cycles, the partially Fluorinated Membrane S1B1 survives 200 cycles. Moreover, the percentage of residual molecular weight of the nonFluorinated Membrane after failure (after 137 cycles) is 34.0%, and of the partially Fluorinated Membrane (after 200 cycles) is 58.8%, respectively. Both Membranes show better peak power densities than a Nafion®117 Membrane operated in VRFB under the same conditions. In contrast to Nafion®117 and S2B2, the S1B1 Membrane shows stable voltage and energy efficiency within the first 60 charge/discharge cycles. Moreover, the Coulomb efficiency of the S1B1 Membrane was higher than that of S2B2 and Nafion®117, respectively, being nearly 100%.