Effect of cobalt addition on BaCe _0˙8 Gd _0˙2 O _2˙9 as electrolyte of solid oxide fuel cell

The effect of cobalt oxide addition on the sintering process and electrical performance of BaCe0˙8Gd0˙2O2˙9 (BCGO) ceramics has been evaluated. By adding 1 mol.-% (1CoBCGO) and 2 mol.-% (2CoBCGO) of cobalt, the density of 1CoBCGO and 2CoBCGO samples can reach 91 and 94% respectively, after sintering at 1300°C for 10 h, and the open current voltages (OCV) of H2/air fuel cell with the electrolytes of which were over 0˙95 V at different temperatures. Moreover, there were abnormal OCV decreases for the two samples under 700°C. AC impedance and fuel cell testing showed 1CoBCGO sintered at 1300°C had a higher electrical performance than that of 2CoBCGO, and was very similar to that of BCGO sintered at 1500°C.