Electroplated Ni–Fe2O3 composite coating for solid oxide fuel cell interconnect application

Ni–Fe2O3 composite coating was applied onto ferritic stainless steel using the cost-effective method of electroplating for intermediate temperature solid oxide fuel cell (SOFC) interconnects application. By comparison, the coated and bare steels were evaluated at 800 °C in air corresponding to the cathode environment of SOFC. The oxidation investigations indicated that the oxidation rate of the coated steel was close to that of the bare steel after initially rapid mass gain. The mass gain of the coated steel was higher than that of the bare steel owing to the formation of double-layer oxide structure with an outer layer of (Ni,Fe)3O4/NiO atop an inner layer of Cr2O3. The area specific resistance (ASR) of the double-layer oxide scale was lower than that of the Cr2O3 scale thermally grown on the bare steel.

► Ni–Fe2O3 composite coating has been electroplated on ferrtitic stainless steel.
► Oxides of NiO/(Ni,Fe)3O4 atop Cr2O3 was thermally grown on the coated steel.
► Cr-free outer layer exhibited a high electrical conductivity.
► Cr-free outer layer offered an effective barrier to Cr outward migration.