A numerical study of liquid water distribution and transport in PEM fuel cell using Cathode-Anode model

Abstract

The performance of a PEM fuel cell that uses hydrogen as the fuel and pure oxygen as the oxidant strongly depends on water management, which has been primarily studied in a single-channel domain. Therefore, there is a need to examine water distribution throughout the entire fuel cell domain, including both the anode and cathode sides. Liquid water can cause flooding in the gas diffusion layer, catalyst layer, and channels, reducing the active surface area of the catalyst and, consequently, the reaction rate. Phase transfer between liquid water and water vapor influences the buildup of liquid water in these domains. In the present work, a three-dimensional, non-isothermal, two-phase numerical model incorporating both the cathode and anode domains has been developed to study water distribution. This model includes water phase transition in the gas diffusion layer, catalyst layer, and channels. The mixed flow distributor is used to analyze water formation and distribution throughout the domain. The study shows that using pure oxygen at the inlet increases the ohmic region in the polarization curve and decreases concentration losses, which could be important for applications such as spacecraft. Additionally, the effects of liquid water accumulation in the porous layers on reactant transport and cell performance are investigated.