Low Temperature Solid Oxide Fuel Cells Using LaGaO₃-based Oxide Electrolyte on Metal Support

Abstract

Solid oxide fuel cells (SOFCs) can directly convert the chemical energy of various fuels to electric power with unmatched energy conversion efficiency. The oxide ion conductivity of LaGaO₃ doped with Sr and Mg (LSGM) is introduced and application of LSGM to low temperature SOFCs is explained. Power density at lower temperature was dramatically increased by application of LSGM film manufactured with laser ablation techniques. By application of a suitable buffer layer, the cell using LSGM thin film electrolyte had reasonable power density (0.2 W cm⁻²) at 773 K. Ce_0.6Mn_0.3Fe_0.1O₂ (CMF) oxide had high activity for the anodic reaction and insertion of a CMF layer much improved the maximum power density (0.17 W cm⁻² at 673 K). Oxide anode consisting of Ce_0.6Mn_0.3Fe_0.1O₂ (CMF)-La_0.6Sr_0.4Fe_0.9Mn_0.1O₃ (LSFM) (=12.5 : 87.5 wt%) enabled the use of dry hydrocarbon for fuel with almost no coke deposition.