Crumpled graphene oxide/spinel cobalt oxide composite based high performance supercapacitive energy storage device

Abstract Crumpled graphene oxide (cGO) was synthesized using a facile liquid phase exfoliation technique mediated by OHˉ cutter; followed by the synthesis of cGO/Co3O4 composite through hydrothermal route involving the as-synthesized cGO and cobalt salt precursors. Co3O4 is a mixed oxide of cobalt that exhibits good redox and charge cycling attributes owing to the presence of Co(II) and Co(III) oxidation states within it. This report includes thorough investigation on the electrochemical and charge storage properties of the fabricated electrodes using cyclic voltammetry, charge – discharge and impedance analyses, and also by endurance test. The report also describes detailed evaluation of the structural properties of the products (cGO and cGO/Co3O4 composites). Two sets of prototype ‘symmetric’ supercapacitors were fabricated using aqueous and gel KOH based electrolytes that successfully lit up LED and run a DC motor. The gel KOH electrolyte based device showed best performance and yielded 44 Wh/Kg specific energy and 1202 W/Kg specific power. The results are quite promising which open up a new avenue for using cGO/Co3O4 composite as a low cost alternative for conventional and costly carbon nanomaterial based supercapacitors.