Preparation And Performance Exploration Of MnCo Protective Film For Sofc Metallic Interconnects

In recent years,people excessively rely on coal,oil and other fossil fuels to burn and turn them into electric energy,which releases a lot of greenhouse gases,mainly CO₂,causing serious environmental pollution and exacerbating the global energy crisis.In the context of global energy shortage and all countries are striving for new clean and environment-friendly energy,fuel cell shows its great opportunity and potential as a green energy.Solid oxide fuel cells（SOFC）are more energy efficient than any other type of power generation device,and the types of fuels available in the SOFC are diverse.The SOFC’s low pollutant emissions and its independence from platinum and other precious metal catalysts also make it a successful new solution to the world’s energy crisis.Traditional solid-oxide fuel cell connectors are mostly made of ceramic materials.However,with the continuous decrease of SOFC operating temperature,metal materials with higher conductivity and thermal conductivity at medium and low temperatures show their unique advantages and become the new favorite of SOFC interconnects.At present,the most commonly used metal interconnect material is stainless steel.However,when stainless steel is applied to SOFC interconnects,there are still a series of problems such as chromium volatilization and toxic cathode.This study attempts to improve the comprehensive performance of ferritic stainless steel as SOFC interconnects by coating.Two kinds of samples of manganese cobalt plating and manganese cobalt cerium plating were prepared by arc ion plating.Through the long-term oxidation experiment on ferritic stainless steel-SUS441 substrate,the comprehensive characterization of two kinds of alloy coating samples was obtained.Compared with previous studies,the innovation of this study lies in the adoption of the preparation process of arc ion plating which is more suitable for industrial production and has higher reproducibility.Meanwhile,Ce doping was investigated on the manganese-cobalt spinel layer.It is found that the manganese-cobalt and manganese-cobalt-cerium spinel films prepared by arc ion plating are in good growth condition.In the test of oxidation and sintering at 800℃for a long time,it showed a strong binding force with the substrate.XRD characterization shows that with the accumulation of sintering time at high temperature,more and more spinel components are formed on the surface of the coating.The cross section and the characterization results of oxidation weight gain show that the alloy coating has good oxidation resistance and certain inhibition of chromium toxicity.In the process of testing the surface resistance of the sample,it is also proved that the sample has excellent conductivity.To made the sample of 40000 h oxidation behavior prediction for a long time,it is concluded that two kinds of alloy coating the surface of the sample resistance are able to meet the department of energy put forward the"40000 h,oxide surface resistance should be less than 100 mΩ·cm²"requirements.At the same time,it was found that the manganese-cobalt alloy coating samples doped with cerium could inhibit the diffusion of various elements more effectively,and then inhibit the oxidation behavior of SOFC connector under high temperature working environment,so that the conductivity of the connector was significantly improved.