Modeling of High-Temperature Polymer Electrolyte Membrane Fuel Cell for Reaction Spatial Variation

A three-dimensional (3D) nonisothermal model is proposed to explore operation in details for high-temperature polymer electrolyte membrane (PEM) fuel cells to investigate the spatial variation of the electrochemical reaction. The model fully couples the reactant flows, heat transfer, gaseous species transport, charge conservation, and electrochemical kinetics in PEM fuel cells. Validation is carried out against two sets of experimental data for Polybenzimidazole(PBI)-based membranes. Numerical results reveal the spatial distributions of flow, hydrogen, oxygen, temperature, proton flux, and electrolyte phase potential in PEM fuel cell. It was found the reaction rate of the oxygen reduction reaction (ORR) varies significantly across the catalyst layer under 0.6 A/cm(2). Through a dimensionless number that measures the degree of the ORR variation, it is indicated that the observed large variation is primarily due to the thick CL considered in the study. Future work includes application of the numerical tool for the design of high-temperature PEM fuel cells and optimization of their operation conditions and model improvement, including incorporation of heterogeneous transport properties in fuel cell electrodes. (C) 2022 Elsevier Ltd. All rights reserved.