Advantages and disadvantages of various cathode flow field designs for a polymer electrolyte membrane fuel cell

In this study, oxygen transport in and water-removal characteristics of a polymer electrolyte membrane fuel cell (PEMFC) with a three-dimensional (3D) complex flow field are numerically investigated. A two-phase, multiscale, multidimensional PEMFC model developed in our previous studies is improved by including Forchheimer's inertial term to more accurately predict two-phase flow in porous media under a strong inertial effect, which is necessary to simulate PEMFCs with complex 3D flow field designs. Numerical simulations are performed under three different cathode flow field configurations, namely, traditional serpentine channels, metal foam, and 3D complex flow channels. The model predictions highlight that the 3D flow field structure induces a substantial degree of flow penetration into the gas diffusion layer, thus greatly improving water removal capability, oxygen transportation, and cell performance. In particular, the stripe-shaped distributions of oxygen concentration, liquid saturation, and current density can be successfully predicted using the cathode 3D flow field structure.