In-situ synthesis of Co3O4/graphite nanocomposite for high-performance supercapacitor electrode applications

Abstract

In this work, a low cost and pollution free in-situ synthesis of phase pure Co3O4 nanoparticles and Co3O4/graphite nanocomposite have been successfully developed via co-precipitation method followed by the thermal treatment process. The prepared samples were characterized by powder X-ray diffraction, scanning electron microscope, high resolution transmission electron microscope, Fourier Transform Infrared Spectroscopy and electrochemical measurements. Electrochemical measurements such as cyclic voltammetry, galvanostatic charge–discharge, electrochemical impedance spectroscopy were carried out in 6M KOH aqueous electrolytic solution. The results show the excellent maximum specific capacitive behavior of 239.5Fg−1 for pure and 395.04Fg−1 for Co3O4/graphite nanocomposite at a current density of 0.5Ag−1. This composite exhibits a good cyclic stability, with a small loss of 2.68% of maximum capacitance over a consecutive 1000 cycles. The investigation indicates that the prepared electrode material could be a potential and promising candidate for electrochemical supercapacitors.