Fabrication of Mn1.5Co1.5O4 by Electrostatic Spray Deposition for Application as Protective Coating on Alloy Interconnects for Solid Oxide Fuel Cells

Mn_1.5Co_1.5O₄ (MCO) protective coating was deposited by Electrostatic Spray Deposition on SS446 alloy for application as interconnects in Solid Oxide Fuel Cells. The main purpose of this work is to verify the feasibility of a thin coating layer prepared by this technique to inhibit the Cr volatilization and the subsequent cathode poisoning. Phase crystallization was obtained after deposition by thermal annealing at 800 °C in air. The corrosion resistance behavior of uncoated and coated steels was investigated by electric and thermogravimetric measurements. The coating films, 400 nm thick, are found efficient for reducing the oxidation rate by limiting the outward Cr³⁺ diffusion. The area specific resistance of the coated steel is found to be considerably low (6.7 mW.cm²) and stable compared to uncoated SS446 alloy (80 mW.cm²) after oxidation for 200 h at 800 °C in ambient air. These results evidence the excellent performance of the deposition technique for fabricating thin, crack free and dense conductive Mn_1.5Co_1.5O₄-coated ferritic alloys.