Excellent supercapacitive performance of a reduced graphene oxide/Ni(OH)2 composite synthesized by a facile hydrothermal route
来源期刊：中南大学学报(英文版)2014年第7期
论文作者：ZHENG Cui-hong(郑翠红) LIU Xin(刘欣) CHEN Zhi-dao(陈志道) WU Zhen-fei(伍振飞) FANG Dao-lai(方道来)
文章页码：2596 - 2603
Key words：supercapacitors; reduced graphene oxide; nickel hydroxide; hydrothermal method; electrochemical performance
Abstract: A reduced graphene oxide/Ni(OH)2 composite with excellent supercapacitive performance was synthesized by a facile hydrothermal route without organic solvents or templates used. XRD and SEM results reveal that the nickel hydroxide, which crystallizes into hexagonal b-Ni(OH)2 nanoflakes with a diameter less than 200 nm and a thickness of about 10 nm, is well combined with the reduced graphene oxide sheets. Electrochemical performance of the synthesized composite as an electrode material was investigated by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge measurements. Its specific capacitance is determined to be 1672 F/g at a scan rate of 2 mV/s, and 696 F/g at a high scan rate of 50 mV/s. After 2000 cycles at a current density of 10 A/g, the composite exhibits a specific capacitance of 969 F/g, retaining about 86% of its initial capacitance. The composite delivers a high energy density of 83.6 W·h/kg at a power density of 1.0 kW/kg. The excellent supercapacitive performance along with the easy synthesis method allows the synthesized composite to be promising for supercapacitor applications.
ZHENG Cui-hong(郑翠红), LIU Xin(刘欣), CHEN Zhi-dao(陈志道), WU Zhen-fei(伍振飞), FANG Dao-lai(方道来)
(Anhui Key Laboratory of Metal Materials and Processing (School of Materials Science and Engineering,
Anhui University of Technology), Ma’anshan 243002, China)
Abstract:A reduced graphene oxide/Ni(OH)2 composite with excellent supercapacitive performance was synthesized by a facile hydrothermal route without organic solvents or templates used. XRD and SEM results reveal that the nickel hydroxide, which crystallizes into hexagonal b-Ni(OH)2 nanoflakes with a diameter less than 200 nm and a thickness of about 10 nm, is well combined with the reduced graphene oxide sheets. Electrochemical performance of the synthesized composite as an electrode material was investigated by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge measurements. Its specific capacitance is determined to be 1672 F/g at a scan rate of 2 mV/s, and 696 F/g at a high scan rate of 50 mV/s. After 2000 cycles at a current density of 10 A/g, the composite exhibits a specific capacitance of 969 F/g, retaining about 86% of its initial capacitance. The composite delivers a high energy density of 83.6 W·h/kg at a power density of 1.0 kW/kg. The excellent supercapacitive performance along with the easy synthesis method allows the synthesized composite to be promising for supercapacitor applications.
Key words:supercapacitors; reduced graphene oxide; nickel hydroxide; hydrothermal method; electrochemical performance
