A numerical study on the performance of polymer electrolyte membrane fuel cells due to the variation in gas diffusion layer permeability

Abstract

Convective flow in the under-rib regions of gas diffusion layers (GDLs) is a non-negligible transport process that can enhance the performance of polymer electrolyte membrane fuel cells (PEMFCs) by facilitating efficient utilization of catalyst layers (CLs) in those regions. The permeability of GDLs has been recognized as a dominant factor influencing the intensity of the under-rib convection in PEMFCs. In this study, the correlation between the permeability of GDLs and the performance of PEMFCs was numerically investigated through a detailed simulation of the transport and electrochemical processes in PEMFCs using a computational fluid dynamics (CFD) tool. Three serpentine flow fields with one, three, or five parallel paths were considered as reactant flow channels for an active cell area of 3 cm × 3 cm, while the permeability of GDLs was varied from 1×10 −12 m 2 to 1×10 −10 m 2 . The effects of the flow field design and the GDL permeability on the performance of PEMFCs were presented, along with their impacts on the local distribution of current density, water content, and reactant concentration.

Efficient fuel utilization by enhancing the under-rib mass transport using new serpentine flow field designs of direct methanol fuel cells

“…One direction is to develop the under-rib mass transport. The roles of the under-rib mass transport were previously studied [2,[12][13][14][15][16][17][18][19][20][21][22]. It was reported that for a specified mass flow rate, the under rib convection is mainly affected by different factors such as the rib width, the pressure difference between the adjacent channels, and the diffusion layer permeability [9,23].…”