Electrochemical study of nanocomposite of nickel cobalt oxide with reduced graphene oxide

Abstract

Nickel cobalt oxide has been explored as one of the most promising mixed metal oxide because of its low cost, abundance in nature, better electrochemical and redox activity and higher theoretical capacitance than Ni oxide and Co oxide. Also, reduced graphene oxide is a low cost alternative of graphene. So, in the present work, Nanocomposite of nickel cobalt oxide-reduced graphene oxide has been prepared by the hydrothermal method for its application as the electrode material for supercapacitor. The structure and texture of the nanocomposite is characterized by X-ray diffraction, Fourier transform infra-red spectroscopy and Field emission scanning electron microscopy. The supercapacitive properties are studied by cyclic voltammetry and galvanostatic charge-discharge measurements. The values of specific capacitance, energy density and power density have been evaluated to be 205 F g-1, 34.5 W h kg-1 and 412 W kg-1 respectively. These results may be ascribed to the highly porous interpenetrating superstructures formed which enhanced ion diffusion and better electrochemical behaviour. Also, the electrochemical impedance spectroscopy studies are done to find the various resistances associated with the electrochemical process.