Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5448546 | Materials Chemistry and Physics | 2016 | 9 Pages |
Abstract
Highly pyrolytic graphite (HOPG) was used as a precursor to produce graphene in an apt ratio of ethanol and water. The as-synthesised graphene was subsequently used to produce graphene-Cobalt oxide (Co3O4) composites via solvothermal method. Morphological and structural characterizations of the prepared composites demonstrated that Co3O4 was successfully formed on the graphene sheet. Electrochemical measurements of graphene-Co3O4 composites from cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy indicated that the mass ratio of graphene to cobalt oxide precursors is crucial to affect their electrochemical performance. The capacitive performance of the graphene-Co3O4 composites electrode prepared at a mass ratio (1:4) exhibited superior specific capacitance of 384Â F/g at a current density of 0.3Â A/g, with an energy density of 64Â Wh/kg and a power density of 103Â kW/kg. The electrode also showed good cycling performance, with about 80% retention of the capacitance after 1000 cycles.
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Authors
Ejikeme Raphael Ezeigwe, Chu Joon Sin, Poi Sim Khiew, Chiu Wee Siong, Michelle T.T. Tan,