Numerical investigation of the anisotropic transport process within PEM fuel cell

The gas diffusion layer (GDL) of proton exchange membrane fuel cells (PEMFCs) exhibits strong structural anisotropy in through-plane and in-plane direction. However, the GDL has usually been simplified as a homogeneous porous structure in numerical modeling, and the anisotropic property of GDL is ignored. In this paper, a three dimensional, non-isothermal, single-phase model with different transport coefficients in through-plane and in-plane direction of the GDL is developed to investigate the effects of anisotropic transport characteristics of GDL on cell performance. From the results, it is found that although the overall cell performance is similar, local distributions, such as local current density and temperature, from the two models are significantly different. The results prove that only the polarization curve is not enough to verify the correctness of a simulation model.