Cedar leaf-like CuCo2O4 directly grow on nickel foam by a hydrothermal/annealing process as an electrode for a high-performance symmetric supercapacitor

The cedar leaf-like CuCo2O4 was synthesized by a hydrothermal/annealing method. The unique nanostructures were beneficial to shortening the paths ion/electron diffusion, providing a larger specific surface area and exposing richer electroactive sites. As a three-electrode system based on cedar leaf-like CuCo2O4, the specific capacitance achieved 1223.2 F/g at a current density of 1.08 A/g, maintained the cycling stability of 88% at a high current density of 10.81 A/g after 2000 cycles, and kept the retention of 50.6% at a current density of 16.22 A/g. Furthermore, the symmetric supercapacitor exhibited the energy density of 26.52 W h/kg at the power density of 763.75 W/kg and the power density of 3057.27 W/kg at the energy density of 12.74 W h/kg. The results demonstrate that the cedar leaf-like CuCo2O4 can be a promising candidate as electrode materials for the real supercapacitor.