Water distribution and transmission within perforated gas diffusion layer and layered gas diffusion layer of a proton exchange membrane fuel cell

Abstract

Effective water management within the gas diffusion layer (GDL) is especially critical to the performance of the proton exchange membrane fuel cell (PEMFC). Various parameters, including operation time, driving voltage, porosity, and structure features, collectively govern water saturation distribution within the PEMFC. Through experimentally validated numerical simulations (with a maximum error of 4.7 % against experimental data), this study examines the effects of different porosity and contact angle distributions of GDL, as well as the addition of a microporous layer (MPL) and perforation, on the water drainage efficiency of a fuel cell under various operating conditions. The findings indicated that GDL's water removal capacity improved as the contact angle and porosity increased. Arranging the porosity in a positive manner or the contact angle in a negative manner effectively enhanced the GDL's water removal capability. A higher difference in porosity between MPL and GDL, with MPL having a lower porosity and a lower thickness ratio, resulted in better water transport performance for the GDL. The GDL utilizes a through-hole structure as a drainage channel for efficient water transport, and a smaller through-hole diameter leads to improved drainage effectiveness.