Effect of gradient porosity distribution in gas diffusion layer on mass transfer and performance of ten-flow channel proton exchange membrane fuel cell

The transport capacity of the gas diffusion layer (GDL) directly affects the uniformity of oxygen distribution and drainage capability within the proton exchange membrane fuel cell (PEMFC), thereby influencing the output performance and lifespan of the PEMFC. This study establishes a three-dimensional two-phase ten-channel PEMFC model and employs numerical simulation to investigate the effects of different GDL porosity distributions on the uniformity of oxygen distribution, drainage capability and output performance of PEMFC. The results indicate that appropriately increasing the porosity along the direction of gas flow can improve the performance of PEMFC, enhancing both the uniformity of reaction gas distribution and the drainage capability. Under a working voltage of 0.6 V, the output performance of porosity with a linear increasing distribution is 5.78 % higher than that with a uniform distribution. Under high current density conditions, logarithmic distribution porosity demonstrates better performance than linear distribution porosity in enhancing the drainage capacity of the GDL and enhancing the output performance of the PEMFC. When the operating voltage is 0.4 V, the output performance is improved by 4.83 %. This study provides a new analysis method and design idea for optimizing the distribution of GDL porosity in practical applications.