Influence of Heat and Mass Transfer Processes on the Electrochemical Performance of Proton Exchange Membrane Fuel Cell

Abstract

Abstract. To investigate the influence of internal heat-mass transfer processes on the electrochemical performance of proton exchange membrane fuel cell (PEMFC), a three-dimensional multiphysics coupling model is developed based on electrochemical mechanisms and porous media multifield coupling theory. A comparison between the simulation results and experimental data demonstrated an error margin within ±15%. Subsequently, the spatial distribution characteristics of key hydrothermal parameters are analyzed along with effects on electrochemical performance. The results show that when the peak current density decreased by 9.6%, the peak water content of the membrane decreased by 1.8% along the flow path, while the lowest liquid saturation increased by 9.6% and the local temperature increased by 0.043%. Additionally, oxygen transport limitations in rib-regions resulted in a 40.4% attenuation of current density at the edges. Along the flow path, the peak values of activation, ohmic, and concentration overpotential decreased by 9.70%, 10.42%, and 11.21%, respectively. Finally, the differences in electrochemical performance are compared under coflow and counterflow gas modes. The results show that the counterflow mode has higher membrane water content, more uniform liquid saturation, and a gentler temperature gradient, with a hotspot temperature 0.23 K lower than that under coflow mode. These findings provide a quantitative basis for optimizing PEMFC hydrothermal management strategies.