Pore Network Modeling of Oxygen Diffusion in Gas Diffusion Layer of Proton Exchange Membrane Fuel Cells Available to Purchase

In the present study, a three dimensional pore network, consisting of spherical pores and cylindrical throats, is developed to simulate the oxygen diffusion and liquid water permeation in gas diffusion layer (GDL) in low-temperature fuel cell. Oxygen transport in the throats is described by Fick’s law and liquid water permeation in the network is simulated using percolation invasion algorithm. The effects of heterogeneity of GDL, connectivity of pores, and liquid water saturation on oxygen effective diffusivity are investigated respectively. The simulation results show that the GDL structure has a significant influence on the oxygen and water transport in the GDL. The oxygen effective diffusivity increases with increasing pore connectivity and decreasing heterogeneity. The shielding effect of large throats by smaller ones enhances with increasing heterogeneity of the network. Furthermore, the oxygen transportation is blocked in the presence of liquid water permeation. Thus the oxygen effective diffusivity drops significantly with increasing water saturation.