Preparation, Evaluation, and Application of SUS430/441 Interconnect with Mn-Co Coating in Solid Oxide Fuel Cells

Mn-Co spinel is one of the most promising coatings for ferrite stainless steel interconnects. This study combines ex-situ and in-situ experiments, evaluating corrosion behavior and electrical performance of SUS430/441 interconnects with Mn-Co spinel coatings prepared by physical vapor deposition (PVD) in air. The ex-situ area-specific resistance (ASR) test indicated that the ASR growth rate of the coated sample at 750℃ was 0.37%/kh, suggesting good corrosion resistance. Under actual operating conditions, the stack with a Mn-Co spinel coating and heat treatment had the lowest ohmic resistance growth rate and performance degradation rate. Thus, a Mn-Co spinel coating applied to the cathode side of the interconnect by PVD can efficiently improve stack stability. Meanwhile, heat treatment at the initial operation of stacks is beneficial to the formation of the Mn-Co coating and the elimination of Cr diffusion.