Two conceptional cathode flow field designs are proposed for preventing serious electrolyte dehydration and overcoming unstable performance issues in polymer electrolyte fuel cells (PEFCs) that are air-cooled and of the passive type. In one design, porous metal foam is selectively inserted into the parallel channels in contact with the cathode gas diffusion layer to suppress water transport from the cell, and the other design has a smaller cathode inlet area to reduce the amount of reactant air entering the MEA. The cathode flow field designs are evaluated through three-dimensional multiscale two-phase PEFC simulations. Compared with a conventional parallel flow-field configuration, the metal foam based design results in better water retention in the MEA when excess dry air is supplied. Furthermore, it shows more uniform distributions of species, temperature, current density, and higher cell performance. The modification of the cathode inlet area has a relatively small influence on the water content profile of the MEA and overall performance of the fuel cell. This study presents a new strategy for designing the cathode flow field for the optimal operation of passive air cooled fuel cells.

中文翻译：

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基于泡沫金属的阴极流场设计提高被动风冷聚合物电解质燃料电池的H2O保留能力


提出了两种概念性阴极流场设计，以防止风冷被动型聚合物电解质燃料电池（PEFC）中严重的电解质脱水并克服不稳定的性能问题。在一种设计中，多孔金属泡沫选择性地插入与阴极气体扩散层接触的平行通道中，以抑制电池中的水传输，另一种设计具有较小的阴极入口面积，以减少进入MEA的反应物空气量。通过三维多尺度两相 PEFC 模拟评估阴极流场设计。与传统的平行流场配置相比，当供应过量的干燥空气时，基于泡沫金属的设计可以在 MEA 中实现更好的保水性。此外，它显示出更均匀的物种、温度、电流密度分布和更高的电池性能。阴极入口面积的修改对MEA的含水量分布和燃料电池的整体性能影响相对较小。这项研究提出了一种设计阴极流场的新策略，以实现被动风冷燃料电池的最佳运行。