Three-dimensional modeling of flow field optimization for co-electrolysis solid oxide electrolysis cell

Abstract

Flow field optimization has an evident effect on the performance improvement of solid oxide electrolysis cells (SOEC). In this study, a novel flow field based on porous material is proposed to improve the electrolysis efficiency of SOEC. The internal reforming reactions, multi-component diffusion process and co-electrolysis of H2O and CO2 are numerically studied by establishing a three-dimensional model. The results show that the novel design with porous material instead of conventional rib-channel configuration can lower the electrolysis voltage demand up to 0.062 V. To understand the mechanisms for the improved performance of the new flow field design, the multi-physical field distributions and thermal process are investigated. It is found that the new flow field design can ensure more uniform distribution of species concentration and reduce the maximum temperature difference by 3.81 K at 1.5 A cm−2. The thermal analysis indicates that the ohmic loss is the most important factor for temperature distribution. In addition, the structure and configuration of porous flow field are further optimized to obtain a better performance.