ZIF-9 derived rGO/NiCo2S4 composite as the electrode materials for high performance asymmetric supercapacitor

Transition metal sulfide is considered as one of the best materials for high-performance supercapacitors because of its excellent conductivity, high theoretical specific capacitance and good thermal stability. Herein, the reduction graphene oxide supported NiCo2S4 (rGO/NiCo2S4) nanomaterial was successfully fabricated at ambient temperature via a facile strategy. Three-dimensional ZIF-9 was used as a tem-plate, graphene oxide was used as the supporting material and Ni(NO3)2 was used as both etchant and Nickel source. As a result, the prepared materials shows a high specific capacitance of 1242.2 F g−1 at a current density of 1 A g−1. Besides, the assembled active carbon (AC)//rGO/NiCo2S4 asymmetric supercapacitor delivered a high energy density of 79.87 Wh kg−1 with a power density of 750 W kg−1 and a capacity retention of 58.5% after 5000 cycles. This work demonstrates an simple design pathway to manufacture bimetallic sulfide and provides basic research for the application of bimetallic sulfide with high surface area and high electrochemical activity used in supercapacitors.