Cathode mathematical model of proton exchange membrane fuel cell
XU Hong feng 1,HAN Ming 2,YI Bao lian 2 (1.Dept. of Applied Chemistry, Dalian Railway Institute,Dalian Liaoning 116028,China; 2.Dalian Chemical Physics Institute,Chinese Academic Science,Dalian Liaoning 116012,China)
The mathematical model of oxygen electrode in proton exchange membrane fuel cell (PEMFC) was established by adopting the macroscopic homogeneous model in one dimension. In the mathematical model,Stefan Maxwell Equation was used for oxygen transferring in diffusion layer as well as Steady Continuous Equation and Fick First Law was used for oxygen transferring in catalyst layer gas channel and in membrane respectively. The distributions of reaction rate and oxygen concentration in catalyst layer were given and the effects of various parameters on the performance of oxygen electrode were analyzed. The results show that: (1) If the porosity of gas phase in catalyst layer is over 0.01, the distribution of oxygen concentration in catalyst layer trends to homogeneity; (2) The best thickness of catalyst layer is about 25 μm; (3) The performance of electrode will be improved by means of the improvement of the proton conductivity in catalyst layer and the effective area of catalyst; (4) For low current density, the distribution of reaction rate is nearly homogeneous while most of the reactions occurred near the diffusion layer in catalyst layer for high current density.