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

• Published in: Journal of energy storage Vol. 42; p. 103021
• Main Authors: Baral, Apurba, Nandi, Anupam, Bose, Navonil, Mukherjee, Nillohit
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2021
• Subjects: Crumpled graphene oxide; Energy storage device; Prototype fabrication; Spinel cobalt oxide; Supercapacitors; Supercapacitors; Prototype fabrication; Energy storage device; Spinel cobalt oxide; Crumpled graphene oxide
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2021.103021

•Crumpled GO/spinel Co3O4 composite based supercapacitors.•Good pseudocapacitance along with EDLC observed due to Co3O4 and cGO.•Co(II)/Co(III) metal centres in the spinel Co3O4 helps in better reversibility.•The synthesized electrode showed 568 F/g specific capacitance.•Device showed notable specific energy (44 Wh/Kg) and specific power (1202 W/Kg).Crumpled graphene oxide / spinel cobalt oxide (cGO/Co3O4) composite based electrodes were fabricated which showed encouraging results in energy storage through supercapacitive manner. The specific capacitance of the electrode was ∼ 568 F/g at a scan rate of 1 mV/s. The specific energy and specific power were also promising and calculated to be 54.22 Wh/kg and 379 W/kg (at current density of 1 A/g) and 43.68 Wh/kg and 4251 W/kg (at current density of 10 A/g). The fabricated device with gel KOH electrolyte showed specific energy of 44 Wh/Kg and specific power of 1202 W/Kg. Good pseudocapacitive behaviour was observed due to the presence of both Co3O4 and cGO along with the double layer capacitance contributed by cGO. Owing to the presence of both Co(II) and Co(III) metal ion centres in the spinel Co3O4, better reversibility was obtained. 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. [Display omitted]