Hierarchically porous nickel oxide nanosheets grown on nickel foam prepared by one-step in situ anodization for high-performance supercapacitors.
Porous NiO nanosheets are successfully grown on nickel foam substrate through an in situ anodization by using molten KOH as the electrolyte. High-purity NiO is directly obtained by this one-step method without any subsequent treatment. The obtained NiO supported on nickel foam is used as a binder-free electrode for a supercapacitor and its pseudocapacitive behavior has been investigated by cyclic voltammetry and galvanostatic charge-discharge tests in a 6 M aqueous solution of KOH. Electrochemical data demonstrates that this binder-free electrode possesses ultrahigh capacitance (4.74 F cm(-2) at 4 mA cm(-2)), excellent rate capability, and cycling stability. After 1000 cycles, the areal capacitance value is 9.4 % lower than the initial value and maintains 85.4 % of the maximum capacitance value.
College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064 (P.R. China), Fax: (+86) 28-85415029.
Li
L
Yang
Lei
L
Qian
Xianqing
X
Tian
Jing
J
Li
Jianyuan
J
Dai
Yong
Y
Guo
Dan
D
Xiao
anodization; electrochemistry; nanostructures; nickel; supercapacitors