在质子交换膜燃料电池(PEMFC)阴极中,电化学反应速率较低,且反应气体传递缓慢,阴极成为限制PEMFC性能提高的主要因素之一。在阴极中发生着各种物理、化学、电学、电化学过程。从孔隙尺度研究有助于深刻理解这些过程。本文利用格子-Boltzmann方法(LBM)研究了PEMFC阴极中的流动、反应物和生成物的传质、质子传递和电化学反应过程。提出了综合模拟阴极中发生的过程的VCCP-LBM方案。讨论了利用VCCP-LBM模拟得到的结果。
Due to its slow kinetics of oxygen reduction reaction(ORR) and mass transport limitations,air cathode is a main limiting factor to performance of PEMFC.Simulations at pore-scale will provide detailed information of fluid flows and mass transports in the cathode of a PEMFC.In this paper,for the first time the lattice Boltzmann method(LBM) is employed to investigate the fluid flow,species concentration distribution,current densities distribution and potential distribution in the cathode of a PEMFC.The two-dimensional computation domain is a cathode including a straight GC (GC),a porous gas diffusion layer(GDL) with micro-blocks and a CL(CL).Using the VCCP-LBM (velocity-concentration-current-potential-Lattice Boltzmann method) codes developed by us,in which some skills are adopted to couple the solutions of mass transports and proton conduct,detailed flow field,species concentration distribution,current densities distribution and potential distribution are obtained under different over potentials.Effects of local porous structures on flow field,species concentration distribution,current densities distribution and potential distribution are discussed.