MnxCo3-xO4 spinel coatings: Controlled synthesis and high temperature oxidation resistance behavior

Abstract

A controllable method for the synthesis of MnxCo3-xO4 (x = 0.4, 0.8, 1.0, 1.2) spinel coatings with unique microstructures and high-temperature oxidation resistances for solid oxide fuel cells is crucially desired. Herein, we report the synthesis and analysis of synthesized coatings with different phase compositions of ferritic stainless steel interconnects. The coatings are fabricated using a sol-gel dip-coating method. Multiple experimental results confirm that the MnxCo3-xO4 coatings exhibit the advantages of having fine grains and uniform density. Furthermore, the as-prepared Mn1.2Co1.8O4 coating has a low coefficient of thermal expansion (11.98 × 10-6 K-1), matching that of ferritic stainless steel, which effectively improves the anti-stripping property of the materials. In particular, oxidation tests illustrate that the oxidation weight gain of this coating decreased by 84.4% compared with bare ferritic stainless steel after 3600 h. The area-specific resistance (ASR) results indicate that the ASR value of the Mn1.2Co1.8O4-coated sample reduced by about 70% compared with those of the ferritic stainless steel samples, which demonstrates its desirable high-temperature oxidation resistance property. It is hoped that this work stimulates new research ideas for the development of spinel oxide coating.