Reduced graphene oxide/Ni foam supported ZIF-67 derived CuCo2S4@CoS2 core-shell heterostructure for boosted electrochemical energy storage

Designing novel multiple composite material with core-shell structure has been demonstrated as an effective method to improve the electrochemical properties of energy storage due to the synergistic effects and structural advantages between the ingredients. Herein, a novel [email protected]2S4@CoS2/NF composite material with core-shell structure was synthesized by ZIF-67 derivatives and the solvothermal method. The composite material overcomes the shortcomings of MOF as an electrode material and provides a large contact area for the active materials and the electrolyte solution. The [email protected]2S4@CoS2/NF electrode exhibits an excellent specific capacity is 1101.2 C g − 1 (2447.1 F g − 1) at a current density of 1 A g − 1 and outstanding cycling performance after 10,000 cycles (79.2% of the initial value). Meanwhile, a typical asymmetric supercapacitor (ASC) device based on [email protected]2S4@CoS2/NF as the cathode and AC as the anode ([email protected]2S4@CoS2/NF//AC) achieves a maximum energy density of 52.46 Wh kg−1 with the power density of 750.02 W kg−1. Moreover, the device maintains the cycle stability of 88.2% after 10,000 cycles, demonstrating that [email protected]2S4@CoS2/NF could be a potential electroactive material in advanced energy storage systems.