采用常规条形流场的质子交换膜燃料电池阴极数值模拟(Ⅱ) 电池性能影响因素的分析

NUMERICAL SIMULATION OF PROTON EXCHANGE MEMBRANE FUEL CELL CATHODE WITH CONVENTIONAL FLOW FIELD(Ⅱ) ANALYSIS OF INFLUENCE ON PERFORMANCE OF PEMFCs

利用已建立的数学模型考察了阴极扩散特性参数、阴极流场几何参数、电极电阻、催化剂活性、流道上O2 浓度变化对H2 AirPEMFCs性能的影响 .计算表明 ,增大氧有效扩散系数、减小扩散层厚度可增大电池的工作电流密度 ;提高氧还原反应交换电流密度、减小电极电阻、优化流道尺寸可改善电池性能 ;沿反应气体流动方向逐渐增加MEA的催化剂负载量可提高电流密度分布的均匀性 .

The effects of parameters on the performance of PEMFCs with conventional flow field operating with air were discussed, including diffusion factors, the geometric parameters of flow field, the resistance of electrode, the activity of catalyst and O 2 concentration in the flow channels, with the mathematical model developed in part I. The limiting current density would increase with increasing oxygen effective diffusion coefficient and decreasing electrode thickness. The performance of PEMFCs would be promoted with increasing exchange current density of oxygen reduction reaction, decreasing resistance of electrode and optimizing geometric parameter of flow field. The uniformity of current density distribution could be improved by increasing catalyst loading along the gas flowing direction.