Numerical analysis of the effect of anisotropic gas diffusion layer permeability on polymer electrolyte membrane fuel cell performance with various channel types

Abstract

In this study, polymer electrolyte membrane fuel cell (PEMFC) models with three types of channels (serpentine, parallel, and interdigitated) were employed to determine which directional permeability of the gas diffusion layer (GDL) predominantly affects PEMFC performance using computational fluid dynamics (CFD). Except for the cathode channel, all PEMFC models contained the same components and were analyzed at identical boundary conditions. The analysis was conducted on a GDL having an isotropic permeability of 10−11 m2 to compare the variations in performance based on changes in the directional permeability of the GDL. Subsequently, we studied permeabilities of 10−10 m2 and 10−12 m2 in each direction, which is the x (in-plane), y (in-plane), and z (through-plane) directions for the three types of channels. That is, seven permeability conditions were applied for each channel type. The CFD results demonstrated that permeability effects were observed at high current density conditions above 1 A/cm2. For the serpentine channel type, the x direction permeability has the most influence on PEMFC performance. The permeability of the specific direction hardly affected the performance of the other channel types. However, the pressure drop in the cathode flow field changed in the interdigitated channel but not the parallel channel.