Synthesis of VS2/NiS Nanocomposites by In Situ Growing NiS Clusters on VS2 Ultrathin Nanoplates for High Performance Supercapacitors

Abstract Novel transition metal sulfide composite VS 2 /NiS nanomaterials are synthesized through a two‐step route, where VS 2 was synthesized by colloidal chemical method, and NiS was in situ grown between the ultrathin and defective VS 2 through a hydrothermal method. The composites showed VS 2 nanoplates wrapped with a NiS clusters structure. Under the 1 : 7 optimal composite ratio, the VS 2 /NiS electrode exhibits a specific capacitance of 2416.5 F/g at 1 A/g, the specific capacitance stays at 930.2 F/g when the current density increases to 20 A/g. The asymmetric supercapacitor assembled with VS 2 /NiS‐1 : 7 and activated carbon electrodes also exhibits an ultrahigh energy density of 69.58 Wh/kg at a power density of 874.9 W/kg and showed good cycling performance with 74.9 % capacitance retention after 3000 cycles. This work not only demonstrates the excellent performance of the VS 2 /NiS composites in supercapacitors, but also provided a new compound strategy for transition metal sulfides.