SrO Doping Effect on Fabrication and Performance of Ni/Ce<sub>1−</sub><i><sub>x</sub></i>Sr<i><sub>x</sub></i>O<sub>2−</sub><i><sub>x</sub></i> Anode-Supported Solid Oxide Fuel Cell for Direct Methane Utilization

The performance of Ni/SrO-doped CeO2 (SrDC) anode-supported cells, combined with the Sm2O3-doped CeO2 (SDC) electrolyte layer, has been investigated for the direct supply of a dry CH4. The SrO content in the Ce1−xSrxO2−x solid solution affects the porous structure of the starting anode support comprising of the sintered NiO and Ce1−xSrxO2−x grains and denseness of the SDC layer by co-sintering. The cell using the 5 mol% SrO-doped CeO2 shows the highest cell performance without time-dependent degradation even at 750°C. This cell (the 5SrDC cell) also provides better cell performance with decreasing operating temperature than the conventional Ni/YSZ anode-supported cell (the YSZ cell); the maximum power density of the 5SrDC cell is higher than that of the YSZ cell by 73% at 650°C. This enhancement effect is discussed in light of the mixed ionic-electronic conduction of the CeO2-based solid electrolytes.