Simple electrochemical preparation of nanoflake-like copper oxide on Cu-plated nickel foam for supercapacitor electrodes with high areal capacitance

Herein, a simple and green two-step electrochemical method was used to prepare nanoflake-like CuO\Cu microparticles on Nickel Foam (NiF) for supercapacitor applications. First, Cu microparticles were plated on NiF through a simple immersion method. Next, the Cu/NiF electrode was electrochemically oxidized in KOH solution to CuO/Cu/NiF. The effect of KOH electrolyte concentration on the electro-oxidation of Cu/NiF was also investigated. FESEM studies show that the surface morphology of CuO/Cu is highly porous, consisting of Cu interconnected microparticles on which islands of CuO have grown. The CuO/Cu/NiF electrode exhibited a high areal capacitance of 0.31 F cm(-2) at a scan rate of 10 mV s(-1) with excellent stability over 1000 voltammetric cycles. The results in this study show the potential application of CuO/Cu/NiF as a low-cost high-performance positive electrode in Supercapacitors.