Current Status of SOFC Development Using Scandia Doped Zirconia

Abstract

The Sc2O3-ZrO2 (ScSZ) system, which has higher electrical conductivity than the Y2O3-ZrO2 system was examined in terms of electrolyte and anode materials of the planar type SOFC. Both electrolyte supported and anode supported type test cells using ScSZ as electrolyte were studied. The electrolyte supported cells were shown to have maximum power density of 2.5W/cm2 in H2-H2O as fuel and O2 at 1273K. For anode supported cells power density of l.OW/cm2 in H2-H2O as fuel and O2 at 1023K was registered. This is considered to be sufficient for low temperature operation. Finally, the performance of the Ni/ScSZ cermet anodes was compared to that of conventional Ni/YSZ cermet anodes. The Ni/ScSZ cermet anodes showed lower overpotential than Ni/YSZ cermet anodes in H2-H2O as fuel at 1273K. Next, internal methane reforming was tested, the Ni-ScSZ cermet anodes showed a lower overpotential and higher stability than the Ni/YSZ cermet anodes at lower S/C ratio.