Numerical modelling of a cathode-supported solid oxide fuel cell (SOFC) in comparison with an electrolyte-supported model

Solid oxide fuel cell (SOFC) is a high-efficiency power generation system that is a large fuel option and converts chemical energy directly into electrical energy. In this study, the parameters affecting the performance of a cathode and an electrolyte supported SOFC are numerically investigated by developing a finite element method (FEM) based SOFC model involving conservation of mass, momentum, species and energy with ionic and electronic charge transfer. After the validation of the mathematical model, effects of support thickness, oxidant type, operating temperature and pressure on the performance of the cells are examined by using a FEM code Comsol. These effects of parameters are shown by the polarization and power curves. As a result of the study, it can be concluded that the performance of the SOFC increases with increasing the operating temperature and pressure values. Compared with the electrolyte-supported, the cathode-supported SOFC is shown to exhibit higher performance in terms of support thickness and operating parameters. The effect of support thickness is seen that the cell power is inversely proportional to the support layer thickness. The improved performance thus the higher hydrogen consumption can be attributed to the lack of N₂ and higher reaction rate when the pure oxygen is used as oxidant. In general it can be said that the cathode-supported SOFC always outperforms the electrolyte-supported SOFC.