Development of a CuFe2O4 interconnect coating

Abstract

Use of commercial grade ferritic steel interconnects in solid oxide fuel cells leads to problems of high resistance and chromium poisoning of the cathode during operation between 750-800°C. To avoid this problem, a novel method of applying coatings for interconnect protection has been tried. Copper and iron films have been deposited sequentially on the surface of a ferritic steel (UNS-430), which upon heat treatment in air at 750-775°C form an adherent coating of CuFe2C4 spinel phase. Electrical and microstructural characterization of spinel-coated steel samples have been carried out. The area specific resistivity (ASR) value of a 15 μm CuFe 2O4-coated sample was found to be as low as 0.025 Ω.cm2.