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

[Display omitted] • The porous lamellar rGO/NiCo 2 S 4 was prepared using simple ZIF-9 templating method. • Bimetallic sulfides have more active pseudocapacitors than monometallic sulfides. • rGO/NiCo 2 S 4 inherits the high specific surface area of the ZIF template and the high pseudocapacitance of the sulfide. • High specific capacity of 1242.4 F g−1 were achieved at the current density of 1 A g−1. 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 NiCo 2 S 4 (rGO/NiCo 2 S 4) 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(NO 3) 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/NiCo 2 S 4 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. [ABSTRACT FROM AUTHOR]