Graphene encapsulated NiS/Ni3S4 mesoporous nanostructure: A superlative high energy supercapacitor device with excellent cycling performance. (1st January 2021)

• Record Type: Journal Article
• Authors: Nandhini, S.; Muralidharan, G.
• Is Part Of: Electrochimica acta. Volume 365(2021)
• Publication Date: 2021-01-01
• Subjects: Supercapacitor -- Graphene -- NiS/Ni3S4 -- Encapsulation -- Asymmetric device; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2020.137367
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: This paper reports the growth of Graphene encapsulated NiS/Ni3 S4 (NSG) on Ni-foam with an aid of Polyethylene glycol. NSG attained a high specific capacitance of 827 C g −1 at 5 A g −1 with an excellent cycling performance. The NSG having higher specific capacitance (44%) than pristine nickel sulphide owing to the encapsulation of graphene. The asymmetric device achieved a energy density of 86.3 W h kg −1 at 2 A g −1 with excellent stability (98%) over 5000 cycles. Abstract: Innovative materials with excellent cyclic performance become the mantra for energy storage. Graphene encapsulated NiS/Ni3 S4 (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. Graphical abstract: Image, graphical abstract