A Proton exchange membrane water electrolysis cell model for analyzing the effects of liquid water supply characteristics on cell performance

Abstract

Proton exchange membrane water electrolyzers (PEMWE) have significant potential for green, high-purity hydrogen production. This study proposes a pseudo-two-dimensional cell-level model that considers all the physical characteristics involved in water electrolysis (WE), such as electron transport in the electrodes, proton transport in the membrane electrode assembly (MEA), water transport between the anode and cathode, gas diffusion in the porous electrodes, two-phase transport in the porous electrodes, and flow channel (FC), including the channel pressure drop and heat conduction across the cell. Liquid water dispersion at the electrode/channel interface is proposed based on a geometrical analysis of the bubble patterns inside the anode channel. The model was validated against the experimental data. The simulation results showed the effects of the liquid water supply characteristics on the cell operation, demonstrating that uniform water, temperature, and pressure distributions on the cell are required for higher performance. Furthermore, efficiency maps with operating constraints under different conditions provide basic guidelines for determining the optimum point of PEMWE operation. The proposed model is appropriate for extensive analysis of physical phenomena inside the PEMWE and rapid simulation for cell optimization.