Effects of micro-porous layer on the two-phase flow in the cathode of polymer electrolyte fuel cells

This study can be divided into two parts. The first part is that to design a gas diffusion layer with linear porosity. Analyzing liquid water saturation and oxygen concentration distribution in gas diffusion layer of cathode gas diffusion layer of PEM fuel cells by using two-phase flow model. We find liquid water due to chemical reactions reduces effective porosity of gas diffusion layer and hinders oxygen transport to reaction site. When the permeability decreases or the contact angle increases, the liquid water saturation and oxygen concentration distribution in gas diffusion layer would be better. The second part is to put a micro-porous layer on the catalyst side of gas diffusion layer. Liquid water transportation is governed by capillary action in pore structure, therefore , the gas and liquid pressure across the interface of these two layers are continuos. The effects of gas diffusion layer and micro-porous layer composed of two materials and characteristics are elucidated.