Facile Synthesis of Ca-Doped LaCoO3 Perovskite via Chemically Assisted Electrodeposition as a Protective Film on Solid Oxide Fuel Cell Interconnects

Abstract

Interconnects in solid oxide fuel cells (SOFCs) serve two essential roles, namely, cell-to-cell electrical connection and the separation of fuel and oxidant gases. It is of practical significance to develop a protective coating that is capable of improving the surface stability of metallic interconnects while maintaining their electrical properties. Perovskite-type oxides are recognized as promising materials for protective coatings; however, it is difficult to fabricate high-density films by conventional powder-sintering processes. In this paper, we report a facile electrodeposition-based approach to preparing perovskite oxide films on SOFC interconnects. A high density, adhesive Ca-doped LaCoO3 perovskite film of ∼1.3 μm thickness is directly formed on an SOFC interconnect through the “chemically assisted electrodeposition” of hydroxide combined with the thermal conversion of hydroxide to oxide. In the proposed synthesis method, the electrodeposition parameters, such as solution composition and deposition time, have a strong influence on the composition, microstructure, and adhesion of the perovskite oxide film. The fabricated film exhibits outstanding performance as a protective coating for SOFC interconnects, as evidenced by a low area-specific resistance of 14.4 mΩ cm2 at 800°C and high stability during both continuous operation and repeated thermal cycling.