Influence of key design variables on the performance and mechanical behavior of an electrochemical hydrogen compressor

Abstract

This study examines the impact of key design variables on the water management, mechanical responses, and overall performance of an Electrochemical Hydrogen Compressor (EHC) cell. A previously developed three-dimensional (3-D) computational model of EHC is applied to different EHC cell geometries, varying in the thicknesses of membranes and the gas diffusion layer (GDL), as well as the widths of the channel and rib in the flow field. Generally, the model's predictions align well with the experimental data measured across a broad spectrum of operating current densities, revealing the intricate interaction between electrochemical/transport phenomena and the mechanical behaviors within the EHC cell. Thinner membranes provide enhanced performance by reducing water shortage at the anode, while increased GDL thickness significantly mitigates cell deformation and stress concentration. Changes in the widths of the rib and channel exert minimal influence on water transport behaviors and cell performance, but they substantially impact mechanical stability. This study underlines the necessity of fine-tuning EHC design factors to strike a balance between mechanical stability and cell performance, thus aiding the practical implementation of EHC technology.