Pore network simulation of transport properties in grooved gas diffusion layer of PEMFC

Three-dimensional pore network model was performed to investigate water and oxygen transport in gas diffusion layer (GDL) with groove. The capillary pressure at breakthrough, the capillary pressure curve, the oxygen effective diffusivity and the relative permeability as a function of liquid saturation were calculated. Moreover, the mechanism of groove was explored from the perspective of pore level. The results indicate that groove changes the capillary pressure distribution of the gas diffusion layer, provides a direct transport path for liquid water and optimizes the gas-liquid distribution in GDL, thereby improving the oxygen effective diffusivity. The position of groove has a significant influence on oxygen diffusion, the influence on liquid transport depends on whether a liquid transport path through GDL is formed. Additionally, the oxygen and water transport enhances with the groove deepen, especially the optimal transmission performance is obtained when the groove penetrates the gas diffusion layer. With increase of the width of groove, while liquid relative permeability improves, oxygen effective diffusivity increases first and then decreases at low water saturation. Based on various factors, the groove parameters are given when the oxygen and liquid water transmission performance is optimal. © All Right Reserved.