泡沫金属在PEMFC流场中的应用

Application of metal foam in PEMFC flow field

优化流场结构,可提高质子交换膜燃料电池(PEMFC)的反应物气体传质和输出性能。泡沫金属是具有高孔隙率和高导电性的多孔材料。建立以泡沫金属为阴极流场的三维单相等温PEMFC模型,并与平行流场、波浪形流场和蛇形阴极流场模型对比,分析化学计量比对PEMFC氧气摩尔分数及电流密度的影响。泡沫金属作为阴极流场,可提高气体扩散层和催化层的反应物气体浓度,从而提高电化学反应效率;工作电压为0.30 V时,燃料电池的电流密度比蛇形流场的提高了38.84%;提高化学计量比,可提高反应气体的摩尔分数及输出性能,当阳极化学计量比从1.5提高到3.0时,气体扩散层(GDL)中的平均氢气摩尔分数提高41.02%,电流密度提高51.80%。

Optimizing the flow field structure could improve the reactant gas mass transfer and output performance of proton exchange membrane fuel cell(PEMFC).Metal foam was porous material with high porosity and high electrical conductivity.A threedimensional single-phase isothermal PEMFC model with metal foam as cathode flow field was established and compared with parallel,wavy and serpentine cathode flow field models,the effects of stoichiometric ratio on oxygen molar fraction and current density of PEMFC were analyzed.As cathode flow field,metal foam could increase reactant gas concentration in gas diffusion layer and catalytic layer,thus improving the electrochemical reaction efficiency.The current density of fuel cell was increased by 38.84%compared with that of serpentine flow field when operating voltage was 0.30 V.Increasing stoichiometric ratio could improve the molar fraction of reactant gas and output performance.When anode stoichiometric ratio was increased from 1.5 to 3.0,the average molar fraction of hydrogen in gas diffusion layer(GDL)increased by 41.02%and the current density increased by 51.80%.