Selective micro-etching of duplex stainless steel for preparing manganese oxide supercapacitor electrode

Abstract In this investigation, manganese oxide electrodes that incorporate selectively micro-etched duplex stainless steel (DSS) for supercapacitor applications were fabricated. The experimental results demonstrate that selective dissolution of the γ phase could result in the formation of α phase network, and vice versa. Controlling the extent of selective dissolution produces a surface with a concave–convex morphology, increasing the surface area. Manganese oxide could then be anodically deposited onto the etched dual phase steel current collector. The experimental results of cyclic voltammetry (CV) show that the specific capacitance increased with the etching depth of either the γ or the α phase. Additionally, selective dissolution occurred in α phase had a better effect on increasing the specific capacitance. The successful application of selective dissolution in fabricating a current collector was thus demonstrated.