SrO Doping Effect on Fabrication and Performance of Ni/Ce₁₋<i>_x</i>Sr<i>_x</i>O₂₋<i>_x</i> Anode-Supported Solid Oxide Fuel Cell for Direct Methane Utilization

Abstract

The performance of Ni/SrO-doped CeO 2 (SrDC) anode-supported cells, combined with the Sm 2 O 3 -doped CeO 2 (SDC) electrolyte layer, has been investigated for the direct supply of a dry CH 4 . The SrO content in the Ce 1¹x Sr x O 2¹x solid solution affects the porous structure of the starting anode support comprising of the sintered NiO and Ce 1¹x Sr x O 2¹x 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.