| Developing excellent Flow-fields is one of the key factors of improving theperformance of Proton Exchange Membrane Fuel Cell (PEMFC). The flow-field structureand materials of bipolar plate are greatly influential to cell performance because flow-fieldstructure and materials decide the flow pattern of reactants and resultants and the long-runstability of fuel cell. Flow-field with rational design can distribute the fuel (alwaysHydrogen) and oxidants (Air or Oxygen) symmetrically and keep cell current distributionsymmetrical. At the same time, it can discharge water resultants with exhaust gas out ofcell smoothly and efficaciously. The work in this thesis focuses on the effects of flow-fieldgeometric structure on cell performance.Firstly, principles and considerations of flow-field design are analyzed. The contactresistance of hard graphite was measured and flow-field fabrication procedure wasdescribed. Then, several different types of flow-field were designed and their influences oncell performance are investigated by using 128cm2 single H2-air cell. Also, the gasdistribution of straight parallel and serpentine channel was analyzed by Navier-Stokesequation. Pressure difference in those flow-fields is measured and calculated.Influence of straight parallel and serpentine flow-field structure, channel depth andwidth, channel and shoulder size is investigated by 128cm2 single cell experiments. Theresults of experiments and model simulation have the same trend.
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