Cu doped Mn–Co spinel protective coating on ferritic stainless steels for SOFC interconnect applications

The Mn–Co serial spinel is a promising coating material for solid oxide fuel cell (SOFC) metallic interconnects. The Cu–Mn–Co spinel powder was obtained by citric acid-nitrate method, and it was applied onto the surfaces of ferritic stainless steel via a slurry dip-coating and subsequent sintering process. The addition of Cu into Mn–Co spinel materials showed two main advantages: Firstly, thermal expansion behavior of Mn–Co spinel was altered, which could be more compatible with that of metallic substrates; Secondly, the sintering temperature was reduced, which was favorable for the dip-coating and sintering process. Long-term isothermal oxidation experiment and ASR (area specific resistance) measurement were investigated. The Cu–Mn–Co spinel protective coating demonstrated excellent anti-oxidation performance, as well as effective action as a mass barrier to the outward diffusion of Cr.