抄録
Solid Oxide Fuel Cells (SOFCs) show a great promise as new power generators with high energy conversion efficiency. Decreasing operating temperature is critically requested for the further improvement in SOFC performance, in particular, for improving stability. Perovskite oxide of LaGaO3, doped with La and Mg exhibits the high oxide ion conductivity over wide PO2 range; the value is higher than that of Y2O3 stabilized ZrO2 by an order of magnitude at 773 K and useful for electrolyte of SOFC operating at intermediate temperature range. When LaGaO3-based oxide was used as the electrolyte of SOFC, the power density could be improved greatly, in particular in low temperature range. In this study, power generation property of SOFC using LaGaO3 electrolyte and also the improvement in power density of the cell by using a LaGaO3 thin film is also introduced. The maximum power density of the cell using LaGaO3 based oxide is as high as 0.6 W/cm2 at 773 K. This suggests that SOFC could be operable at temperature lower than 773 K. Tubular type cell stack using LSGM thin film is also introduced.
