Superior La1 − xSrxCoO3 − δ ceramic electrode fabrication by MOCSD for low-temperature SOFC application

Abstract

Metalorganic chemicalsolutiondeposited lanthanum strontium cobaltite (LSC, La-1-xSrxCoO3-delta) nanoporous thin films were fabricated for use as cathodes for lowtemperature solid oxide fuel cells (LT-SOFCs). Electrochemical performance and durability were evaluated under continuous operation by comparing with typical Pt cathode SOFCs. In the initial stage of operation, SOFCs with Pt cathodes showed higher output power density for its superior catalytic activity. However, the overall performance of SOFCs with Pt cathodes gradually degraded due to thermal instability, while the performance with LSC cathodes remained stable for 10 h of continuous operation. In addition, by taking advantage of wet chemical solution methods, the amount of dopant was systematically varied to investigate its effect on fuel cell performance (La-1-xSrxCoO3-delta, x = 0.4, 0.5, 0.6). The fuel cell sample with the dopant ratio x = 0.5 showed the highest peak power density independent of the operating temperature. This result implies that LSC cathodes deposited by chemical solution deposition show better operational durability than Pt cathodes and provided potentiality of replacing precious metal cathode for low temperature SOFCs.