A Modeling Study of Porous Electrode Property Effects on Solid Oxide Fuel Cell Performance

Abstract

A two-dimensional isothermal mathematical model is developed for an anode-supported planar solid oxide fuel cell (SOFC). The model takes into account the complex coupling effects of multi-physics processes including mass transfer, charge (ion/electron) transport, and electrochemical reaction. The SOFC multi-physics processes are numerically linked to SOFC global performance such as polarization curve. The model is validated using polarization curve as a metric with the experimental data from open literature. Since triple phase boundary reaction zone may vary from the vicinity of the electrolyte all the way to the entire electrode depending on selected materials and fabrication process, the effects of anode active reaction zone with different volumes are investigated comprehensively for a generic button cell using the developed mathematical model. The tradeoff design between active reaction zone volumes and other design parameters such as porosity and tortuosity of electrodes are also examined. Results show that porous composite electrode properties have very complex effects on SOFC performance. The results may provide a valuable guidance for high performance SOFC design and fabrication.