Fabrication of three-dimensional CuS2@CoNi2S4 core–shell rod-like structures as cathode and thistle-derived carbon as anode for hybrid supercapacitors

Abstract

The unique 3D rod-like structure has a broad range of potential applications for energy storage. In this work, a three-dimensional core–shell cathode material CuS2@CoNi2S4 and a porous rod-like anode material thistle-derived carbon (TDC) are synthesized for hybrid capacitors. Among them, the cathode CuS2@CoNi2S4 was prepared by straightforward in-situ growth and solvothermal method, showing excellent specific capacitance (1191.6 C g−1 at 1 A g−1), as well as enhanced cyclic stability (85.7% after 10,000 cycles). And the anode TDC was prepared by alkali activation and high temperature calcination, which showed a better double-layer energy storage behavior compared with activated carbon. The assembled hybrid capacitors which benefit from the synergistic effect of cathode core and shell and the porous structure of anode show high energy density (79.5 Wh kg−1 at 800 W kg−1) and long cycle performance (84.5% after 10,000 cycles), indicating that they have great application potential in the domain of supercapacitors. In short, the distinct cathode and anode structural designs offer a novel approach to the synthesis of electrode materials in the realm of energy storage.