The thermal effects of all porous solid oxide fuel cells

Abstract

All porous solid oxide fuel cells adopt a porous electrolyte to resist coking caused by hydrocarbon fuels such as methane. With O2 molecules coming from the cathode, chemical oxidation reactions occur at the anode, competing with the electrochemical oxidations with O2− ions. These reactions release a lot of heat, thus significantly affects the cell's power density and fuel efficiency. In this paper, we developed a 2D thermal-electrochemical model to study its thermal effects. After model validation, parametric studies are conducted to investigate the impact of operating condition and cell structure. Cell performance, including power density, coking resistance, peak cell temperature, heat source composition, and energy efficiency is analysed. Notably, the detailed heat-releasing processes at different operating conditions are discussed. A power density of 373 mW cm−2 is obtained when a CH4 and O2 concentration of 10% and an electrolyte thickness of 200 μm are adopted. This model can serve as a useful tool for the optimization of operating conditions and geometry design to improve the performance and coking resistance of solid oxide fuel cells.