Performance of nickel–scandia-stabilized zirconia cermet anodes for SOFCs in 3% H2O–CH4

The performance of solid oxide fuel cells (SOFCs) with a nickel–scandia-stabilized zirconia (Ni–ScSZ) anode and a nickel–yttria-stabilized zirconia (Ni–YSZ) anode was examined at a low steam/methane ratio (S/C) of 3% H2O–CH4. The power density of the cell with the Ni–ScSZ anode showed 0.85 W/cm2 at 0.85 V at 1273 K without degradation of power density during over 250 h. A whisker-shaped graphite was observed on a part of the Ni–ScSZ surface after the generation tests. On the other hand, the Ni–YSZ anode showed the power density of 0.8 W/cm2 at an initial stage and degraded to be 0.6 W/cm2 after 250 h. The degradation of the power density could be explained by the formation of amorphous carbon on the Ni-particles by the methane decomposition.