Graphene encapsulated NiS/Ni3S4 mesoporous nanostructure: A superlative high energy supercapacitor device with excellent cycling performance

Innovative materials with excellent cyclic performance become the mantra for energy storage. Graphene encapsulated NiS/Ni3S4 (NSG) nanostructure is synthesized via polyethylene glycol assisted one-step hydrothermal method. The encapsulated nanostructure is examined for supercapacitor applications. The NSG nanostructure offers a large specific capacity of 827 C g(-1) at 5 A g(-1) (pristine PEG assisted nickel sulphide yields 574 C g(-1)) and shows good cyclic stability (88%) and Coulombic efficiency (95%) after 5000 cycles at a high and practically useful specific current of 70 A g(-1). The superior electrochemical performance of NSG is due to its high conductivity, high surface area, a synergistic effect between the graphene and nickel sulphide and their mesoporous graphene encapsulated nanostructure. The NSG and reduced graphene oxide based asymmetric supercapacitor device achieves a maximum energy density of 86.3 W h kg(-1) at 2 A g(-1) with excellent device stability (98%) over 5000 cycles. The superior electrochemical features of NSG makes it a potential electroactive material for supercapacitor applications. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

In this study, graphene encapsulated NiS/Ni3S4 (NSG) nanostructure was synthesized and examined for supercapacitor applications, showing superior electrochemical performance in terms of specific capacity and cyclic stability. The asymmetric supercapacitor device based on NSG and reduced graphene oxide achieved a high energy density and excellent device stability over 5000 cycles, making NSG a potential electroactive material for supercapacitor applications.