Brush-like nickel ferrite nanosheets decorated CuCo2O4/CuO nanowire arrays as high-performance electrode for all-solid-state asymmetric supercapacitors

The inferior energy density limits the practical application and sustainable development of supercapacitors. Excellent electrode materials can effectively improve the specific capacitance and operating potential window. Thus, we deposit brush-like nickel ferrite (NiFe2O4) nanosheets and CuCo2O4/CuO nanowire arrays to construct a binder-free electrode with tree-like CuCo2O4/CuO/NiFe2O4 arrays. The resulting CuCo2O4/CuO/NiFe2O4 electrode shows an outstanding specific capacitance (2067 F/g) and wide potential window (-0.1-0.6 V). The contribution rate of surface faradaic redox reaction is calculated to be 71% at 1 mV/s and assembled CuCo2O4/CuO/NiFe2O4//AC device realizes a remarkable energy density (77.1 Wh/kg at power density of 851.4 W/kg) and cyclic performance (92.9% of initial specific capacitance retained after 10,000 cycles). Apparently, the CuCo2O4/CuO/NiFe2O4 electrode as a novel binder-free electrode has great application potential and our work offers a novel idea to construct the arrays of multicomponent composite materials.