Pore-scale flow and mass transport in gas diffusion layer of proton exchange membrane fuel cell with interdigitated flow fields

Abstract

Lattice Boltzmann method (LBM) is employed to investigate pore-scale flow and mass transport in a carbon paper gas diffusion layer (GDL) of interdigitated PEMFC. The carbon paper GDL is reconstructed using the stochastic method, and its macroscopic transport properties are numerically predicted. The predicted anisotropic permeabilities and effective diffusivity of the reconstructed GDL agree well with existing measurements. Then, effects of the porous structures of the carbon paper GDL are explored in terms of fluid flow, species transport and electrochemical reaction. The GDL porous structures greatly affect flow and mass transport, creating distinct specie concentration distribution and local current density distribution. Besides, simulations are performed to explore liquid water behaviors in the reconstructed GDL. The simulation results present a detailed description of the pore-scale liquid water behaviors. Further, simulations are performed to investigate the effects of land width and GDL contact angle on liquid water removal time and residual saturation. Narrower land reduces liquid water removal time and residual saturation. Higher contact angle increases the removal time and reduces the residual saturation.