Effects of water dynamic behavior on oxygen transport in catalyst layers: A pore-scale study of proton exchange membrane fuel cells

Abstract

Gaining insight into the transmission properties of the catalyst layer (CL) in proton exchange membrane fuel cell (PEMFC) is essential for optimizing performance. This study employs a pore-scale approach to investigate the formation, distribution, and migration of water and its effect on oxygen transport within the CL. A coupled lattice Boltzmann method (LBM), integrating two-phase flow and oxygen transport, is employed to analyze mass and water transfer. The performance of different CL structures, including high surface carbon (HSC) and low surface carbon (LSC), along with their layered and doped configurations, is evaluated. The results reveal that HSC structures are significantly impacted by liquid water saturation in primary pores, where the reactive surface area increases by approximately 64 % as saturation rises from 0 to 0.5. Additionally, the distribution of water in the secondary pores from the view of LSC is more affected by the contact angle. The study highlights that the layered H_LSC configuration effectively enhances water management and oxygen transport, even under high water saturation conditions. These findings provide deeper insights into the relationship between CL structure and its impact on the overall performance of PEMFCs.