SrO Doping Effect on Fabrication and Performance of Ni/Ce_(1-x)Sr_xO_(2-x)Anode-Supported Solid Oxide Fuel Cell for Direct Methane Utilization

摘要

The performance of Ni/SrO-doped CeO_2 (SrDC) anode-supported cells, combined with the Sm_2O_3-doped CeO_2 (SDC) electrolyte layer, has been investigated for the direct supply of a dry CH4. The SrO content in the Ce_(1-x)Sr_xO_(2-x)- solid solution affects the porous structure of the starting anode support comprising of the sintered NiO and Ce_(1-x)Sr_xO_(2-x) grains and denseness of the SDC layer by co-sintering. The cell using the 5 mol SrO-doped CeO_2 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 CeO_2-based solid electrolytes.