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

Low-temperature solid oxide fuel cells revitalizing usage of metallic interconnects over former ceramic materials. However, chromium poisoning is reducing the performance of ferritic interconnects. To resolve this problem, an attempt to layer metal-oxide coating has been considered. This article encloses the fabrication of optimized slurry composition of CuFe2O4 spinel over Crofer 22 APU and SUS 430 by using the dip-coating technique. These coated samples were dried, heated at 800oC in reducing environment (5% hydrogen and 95% nitrogen), oxidized in the open air and lastly annealed. SEM-EDS results are confirming that spinel protection layer has been fabricated over steel substrates, avoiding any spallation. Annealing reduced thickness of oxide layer from 7.25µm to 4.69µm and improved density of spinel. Spinel coated Crofer 22 APU and SUS 430 formed three and four layers with weight gain rate of 1.65 x 10-12 g2 cm-4.s-1 and 2.597 x 10-12 g2cm-4.s-1 respectively. Decarburization was also observed in both substrates during operational heating and annealing process. The research reveals that the spinel is the promising protective layer for interconnects of SOFC and annealing is the better processing technique for achieving the preferred properties.