A facile one-step route to synthesize of novel porous reduced graphene oxide@nickel sulfide (rGO@Ni3S2) core shell nanostructures for high-performance supercapacitor electrodes

Abstract

In the last decade, there has been significant interest in the use of supercapacitors with high power density and cycle stability in a wide range of applications. Graphene-based hybrid electrodes are considered a very promising option for supercapacitors owing to the synergistic effects they exhibit. In this study, we provide a novel and efficient method for synthesising a core-shell nanocomposite consisting of reduced graphene oxide (rGO) wrapped around nickel sulphide (Ni3S2) using a one-step hydrothermal process. The resulting rGO@Ni3S2 composite exhibits excellent performance as a supercapacitor electrode while also being cost-effective. As a promising supercapacitor electrode, a relatively high specific capacitance of 1052.5 Fg−1 at current density of 1 Ag−1 in 1 mol.L−1 KOH aqueous solution, along with good cycling stability (with a 94.5 % retention rate after 10,000 cycles) were demonstrated for the rGO@Ni3S2 core shell composite electrode. In addition, excellent electrochemical performances were also demonstrated for the asymmetric supercapacitor (ASC) by using rGO@Ni3S2 as the cathode and activated carbon, respectively. The fabricated ASC showed with a high energy density of 61.9 Whkg−1 at the power density of 585.7 W kg−1. Such high performance of rGO@Ni3S2 core shell electrode can enrich the prospects for future practical applications in energy storage.