Mixed-Fuels Fuel Cell Running on Methane-Air Mixture

Abstract

In order to develop solid oxide fuel cells (SOFCs) running on hydrocarbon fuels, we have focused on a new method of improving electrode performance and reducing carbon deposition by coating thin films of samaria-doped ceria (SDC) within the pores of electrode by a sol-gel coating technique. The SDC coating on the pores of anode made it possible to have a good stability for long-term operation due to low carbon deposition and nickel sintering. In this study, we demonstrated a new method of improving electrode performance and reducing carbon deposition by coating thin films of samaria-doped ceria and applied the modification technique to two different types of fuel cell structures, anode-supported SOFC and comb-shaped SOFC. From our results, the maximum power density of an anode-supported cell (electrolyte; 8 mol% YSZ and thickness of 30μm, and cathode; La0.85Sr0.15MnO3) with the modified anode was ∼300mW∕cm2 at 700°C in the mixture of methane (25%) and air (75%) as the fuel, and air as the oxidant. The cell was operated for 500hr without significant degradation of cell performance. For the comb-shaped SOFCs operated in the mixed-fuels fuel cell conditions, the cell performance was 40mW∕cm2 at 700°C in the CH4∕O2 ratio of 1.