Ni/Co-MOFs derived NiS2/Co3S4 heterostructured microspheres for high-performance asymmetric supercapacitors

Abstract

Despite the relatively mature state with respect to the technology for synthesizing transition metal sulfide structure, preparation of heterostructured transition metal sulfides with superior structure and high specific capacitance is still challenging. Herein, we prepared NiS2/Co3S4 heterostructured microspheres by the two-part hydrothermal method using bimetallic MOFs as precursors. By constructing this heterostructure, we aimed to modify the electronic structure of electrode materials to enhance the electrochemical performance. We did not need carbonization in the preparation process and showed good electrochemical properties with a great appearance. Experimental and characterization analysis demonstrated the successful synthesis of NiS2/Co3S4 heterostructured microspheres. The NiS2/Co3S4 electrode manifests a specific capacity of 252.3 mAh/g at 1 A/g. Furthermore, the hybrid asymmetric supercapacitor with NiS2/Co3S4 as the positive electrode has the energy density of 4.29 Wh kg−1 at the power density of 61.99 W kg−1 according to the stack volume. These heterostructured mixed metal sulfide electrode materials with high specific capacity and high rate provide new ideas for research.