Hieratical CuO clusters in-situ grown on copper films coated three-dimensional nickel foams for high-performance supercapacitors

Abstract Copper oxides (CuO) are promising pseudocapacitive materials for supercapacitors. However, the intrinsically poor electronic conductivity limits their applications. Herein, an electrode with hieratical CuO clusters based on nickel foams (CuO–Ni) are synthesized via the electroless copper plating and chemical etching process. The specific areal capacitance of CuO–Ni electrode in aqueous 6 M KOH solution reaches up to 1.61 F cm−2 at 3 mA cm−2 (equivalent to 679 F g−1 at 1.27 A g−1), and retains 93.6% after 5000 testing cycles, which is mainly attributed to their perfect hieratical structure and high electrical conductivity. The asymmetric supercapacitor device was assembled with the positive electrode of CuO–Ni and negative electrode of active carbon (AC). The energy density reaches up to 43.12 Wh kg−1 even at a high power density of 2.12 kW kg−1. This work offers a facile and attractive strategy for the rational construction of electrodes for supercapacitors with high-performance.