Electrocapacitive performance of graphene/Co sub(3)O sub(4) hybrid material prepared by a nanosheet assembly route

• Published in: Electrochimica acta Vol. 119; pp. 184 - 191
• Main Authors: Li, Qi, Hu, Xiaona, Yang, Qian, Yan, Zhe, Kang, Liping, Lei, Zhibin, Yang, Zupei, Liu, Zonghuai
• Format: Journal Article
• Language: English
• Published: 10.02.2014
• Subjects: Capacitance; Capacitors; Electrodes; Graphene; Nanocomposites; Nanostructure; Oxides; Supercapacitors
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2013.12.066

Graphite oxide/Co(OH) sub(2) layered composites are prepared by nanosheet assembling between the exfoliated Co(OH) sub(2) and graphene oxide (GO) nanosheets. The subsequent thermal treatment of GO/Co(OH) sub(2) composites in controlled atmospheres converts GO into reduced graphene oxide (RGO) and Co(OH) sub(2) into Co sub(3)O sub(4). The RGO/Co sub(3)O sub(4) hybrid nanocomposites with different amounts of Co sub(3)O sub(4) are thoroughly characterized, and their electrochemical properties as supercapacitor electrode are systematically investigated by cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy in the KOH electrolyte. In particularly, the RGO/Co sub(3)O sub(4) hybrid composite with 94.3 wt% Co sub(3)O sub(4) exhibits a high specific capacitance of 331 F g super(-1) at the current density of 5 A g super(-1), and shows the excellent electrochemical cycle stability with capacitance retention over 122% after 5000 continuous charge-discharge cycles. These outstanding capacitive performances make the RGO/Co sub(3)O sub(4) hybrid nanocomposites one of the promising candidates for the supercapacitor electrode.