质子交换膜燃料电池阴极梯度催化层的数值模拟

Numerical Simulation of Cathode Gradient Catalytic Layer in Proton Exchange Membrane Fuel Cell

质子交换膜燃料电池催化层中使用的商用Pt催化剂价格昂贵,优化催化层成分分布对降低电池成本、提高Pt利用率和改善电池性能具有重要意义。本研究采用数值模拟技术计算了含有两个子层的梯度催化层和传统单层催化层的流体流动、传质、电化学反应过程,对比两者的模拟结果发现:当催化剂、离聚物和孔隙以梯度的形式分布时,改善了阴极反应物氧气的传输和生成物水的排出,梯度催化层的电池性能明显优于平均分布催化层的电池性能。

Commercial Pt catalysts used in the catalytic layer of proton exchange membrane fuel cells(PEMFC)are expensive,so optimizing the distribution of the catalytic layer is of great significance to reduce the cost,improve the utilization ratio of Pt and improve the performance of the fuel cell.The fluid flow,mass transfer and electrochemical reaction processes in the gradient catalytic layer with two sub-layers and in the traditional monolayer were both calculated by numerical simulation.Comparing the simulation results of two cases,it was showed that the oxygen transport of the cathode side and the effluent of the product water were improved when the catalyst,ionomer and pore were distributed in gradient,so the battery performance of the gradient catalytic layer was obviously better than that of the evenly distributed catalytic layer.