Design of Zn0.76Co0.24S nanoparticles anchored to orthohexagonal Co3S4 nanosheets for high-performance asymmetric supercapacitors

The design of nanocomposite materials with special stable structure has become the consensus of researchers working on the exploitation of new materials for effective energy storage equipment. Herein, for the purpose of solving the problem of low capacity and short cycle life of the materials used for supercapacitors, we use Co-3(VO4)(2) with orthohexagonal nanosheet structure as the transition template, utilizing ion exchange reaction to prepare Co3S4 with a two-dimensional structure. At the same time, the surface of Co3S4 nanosheets were anchored by some Zn0.76Co0.24S nanoparticles through hydrothermal reaction. The prepared Co3S4/Zn0.76Co0.24S composite displays a satisfactory specific capacitance of 1832.1 F g(-1) at a current density of 1 A g(-1) and an outstanding conductivity. After 4000 times of continuous charge and discharge cycles, it still presents a good capacitance (94.6% retention). The tests on the assembled Co3S4/Zn0.76Co0.24S//AC device show an energy density of 55.6 Wh kg(-1), while the power density is 690.9 W kg(-1). With such a remarkable electrochemical performance, the prepared Co3S4/Zn0.76Co0.24S composite is considered as an excellent candidate for supercapacitors application.