Numerical Investigation on Effects of Perforated Gas Diffusion Layers on Performance and Transports in a PEFC with a Single Channel Serpentine Flow Field

The gas diffusion layer (GDL) is an essential component of a polymer electrolyte fuel cell (PEFC). Not only does it provide mechanical support, allows reactants to flow toward the catalyst layer (CL) and helps water vapor reach the membrane, but it also enables capillary liquid transport away from the electrodes to avoid large concentration overpotentials and cell instability due to flooding. Artificially developing pathways for water removal using laser perforation is one of the techniques proposed to engineer water transport within the GDL. Because the capillary pressure in larger holes is lower than in the surrounding area, water from the neighbourhood is carried through the pores, leaving the remaining regions free of water and enabling better gas diffusion. The impacts of perforated GDLs, i.e., perforation location, on cell performance and other transport characteristics in a 5.1 cm2 PEFC with a single channel serpentine flow channel design are investigated in this paper. A full-cell numerical simulation was carried out in ANSYS FLUENT. The results revealed that the best flow channel design for the small-scale PEFC (the single-channel serpentine) might offer an even more outstanding performance of roughly 14% through perforating GDLs. Not only the performance but also the perforation provided better uniformity. The findings of this study potentially benefit the development of a GDL for water management in the PEFC operation.