New interconnector designs for electrical performance enhancement of solid oxide fuel cells : a 3D modelling study

Abstract

Interconnector (IC) is a critical component of solid oxide fuel cell (SOFC) stack for current collection and gas distribution. However, the commonly used IC design causes low average SOFC stack performance due to the highly uneven distribution of gas (especially O2) in the porous electrodes and the contact resistance between IC and electrode. In this study, several unconventional IC designs are proposed and studied numerically by 3D multi-physics modeling. Compared with the traditional straight channel-based IC design, the new IC design can achieve more uniform distribution of O2 in the cathode of SOFC. As a result, the peak power density of SOFC can be improved by up to 27.86%. The performance improvement can be attributed to the discrete distribution of ribs, the reduction of rib size, and the spatial layout arrangement of discrete ribs, which may shorten gas diffusion path, current collection path, or both. It is also found that the performance degradation caused by IC oxidation is highly related to the contact area between IC and electrode. In addition, the increased parasitic power loss induced by the newly designed IC is less than 0.1% of the increased electric power, so it can be neglected.