Mitigation of Chromium Poisoning of Ferritic Interconnect from Annealed Spinel of CuFe₂O₄

Low-temperature solid oxide fuel cells permit the possibility of metallic interconnects over conventional ceramic interconnects. Among various metallic interconnects, the ferritic interconnects are the most promising. However, chromium poisoning in them adversely affects their performance. To resolve this issue, various coatings and pretreatment methods have been studied. Herein, this article encloses the coating of CuFe(2)O(4)spinel over two prominent ferritic interconnects (Crofer 22 APU and SUS 430). The CuFe(2)O(4)spinel layer coating has been developed by the dip-coating of both samples in CuFe(2)O(4)slurry, followed by heat treatment at 800 degrees C in a reducing environment (5% hydrogen and 95% nitrogen). Additionally, both samples were annealed to further enhance their spinel coating structure. The morphological and crystallinity analysis confirmed that the spinel coating formed multiple layers of protection while annealing further reduced the thickness and improved the densities. Moreover, the area-specific resistance (ASR) and weight gain rate (WGR) of both samples before and after annealing was calculated using mathematical modeling, which matches with the experimental data. It has been noted that CuFe(2)O(4)spinel coating improved the ASR and WGR of both samples which were further improved after annealing. This research reveals that the CuFe(2)O(4)spinel is the promising protective layer for ferritic interconnects and annealing is the better processing technique for achieving the preferred properties.