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 hypes of fuel cell structures, anode-supported SOFC and comb-shaped SOFC. Front our results, the maximum power density of an anode-supported cell (electrolyte; 8 mol% YSZ and thickness of 30 mu m, and cathode; La0.85Sr0.15MnO3) with the modified anode was similar to 300 mW/cm(2) at 700 degrees C in the mixture of methane (25%) and air (75%) as the fuel, and air as the oxidant. The cell was operated for 500 hr without significant degradation of cell performance. For the comb-shaped SOFCs operated in the mixed-fuels fuel cell conditions, the cell performance was 40 mW/cm(2) at 700 degrees C in the CH4/O-2 ratio of 1.