Intermediate temperature solid oxide fuel cells using LaGaO₃ based perovskite oxide for electrolyte

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 P _o2 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 LaGaO ₃-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.