title: Development of high energy density supercapacitor through hydrothermal synthesis of RGO/nano-structured cobalt sulphide composites.
abstract: Co9S8/reduced graphene oxide (RGO) composites were prepared on nickel foam substrate through hydrothermal reaction and used directly as supercapacitor electrode. The field emission scanning electron microscopy analysis of the composites showed the formation of Co9S8 nano-rods on the RGO surfaces. The average crystal size of the Co9S8 nano rods grown on the RGO sheets were ∼25-36 nm as calculated from x-ray diffraction analysis. The reduction of graphene oxide (GO) was confirmed by Raman and x-ray photoelectron spectroscopy analysis. The electrical conductivity of the Co9S8/RGO composite was recorded as 1690 S m(-1) at room temperature, which is much higher than that of pure GO further confirming the hydrothermal reduction of GO. Cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy were investigated to check the electrochemical performances of the Co9S8/RGO composites. The Co9S8/RGO composites supported on nickel foam showed very high specific capacitance (Sc)(1349 F g(-1) at a current density of 2.2 A g(-1)), energy density (68.6 W h kg(-1)) and power density (1319 W kg(-1)) in 6 M KOH electrolyte. The retention in Sc of the composite electrode was found to be ∼96% after 1000 charge-discharge cycles.
authors: Surface Engineering & Tribology Division, Council of Scientific and Industrial Research-Central Mechanical Engineering Research Institute, Durgapur-713209, India. Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi-110001, India.
authors: Milan
authors: M
authors: Jana
authors: Sanjit
authors: S
authors: Saha
authors: Pranab
authors: P
authors: Samanta
authors: Naresh Chandra
authors: NC
authors: Murmu
authors: Nam Hoon
authors: NH
authors: Kim
authors: Tapas
authors: T
authors: Kuila
authors: Joong Hee
authors: JH
authors: Lee