Oxide Anode Derived from Sr-Doped LaMnO3 Perovskite Oxide for SOFCs Using LaGaO3 Electrolyte

Various oxides were investigated as a ceramic anode of solid oxide fuel cells (SOFCs) using LaGaO 3 -based oxide electrolyte. It was found that the cell using Sr-doped LaMnO 3 for anode exhibits a fairly large power density among the examined oxides for anode. Because the anodic overpotential as well as the electrical resistance decreased, the power density of the cell increased with increasing the amount of Sr doped for La site in LaMnO 3 , and the highest power density of the cell was obtained by using La 0.5 Sr 0.5 MnO 3 for anode. On this cell, the maximum power density was achieved to a value of 0.64 and 0.25 W/cm 2 at 1273 and 1073 K, respectively. After exposure of the cell to air at 1273 K for 24 h, almost the same power density was recovered by changing air to H 2 . X-ray diffraction measurement suggests that the perovskite phase of La 0.5 Sr 0.5 MnO 3 anode partially decomposed into La 2 MnO 4 , MnO 2 , and SrMnO 3 after the power generation measurement; however, small power density can only be achieved on the cell using MnO 2 , SrMnO 3 , La 2 MnO 4 , and LaSrMnO 4 for anode. Therefore, LaMnO 3 perovskite phase doped with Sr is active as the anode of SOFCs, which is highly tolerant against oxidation.