Effect of rib width on the thermo-electro-mechanical behavior of solid oxide fuel cells

Abstract

In this study, a three-dimensional multi-physics coupled model is employed to investigate the effects of the rib width of the cathode-side interconnect on the flow characteristics, electrochemical performance, temperature distribution and stress distribution of solid oxide fuel cells (SOFCs) under cross-flow conditions based on a fixed gas channel-electrode interface area. The results show that as the rib width is reduced, there is a marked improvement in the uniformity of gas distribution and gas flow velocity within the channels, leading to an increase in the output power density of the SOFC stack, a reduction in the temperature gradient of the cell and a reduction in the thermal stress carried by the cell. However, if the ribs are of insufficient width, the pressure drop within the channels will be significantly increased, reducing the static pressure head of the gas and leading to a decrease in the gas flow velocity within the electrodes. This, in turn, will result in an increase in concentration polarization and higher manufacturing costs. The simulation results facilitate a more detailed comprehension of the internal reaction processes of SOFCs, thereby offering valuable guidance for the structural optimization of interconnects.