Hierarchical 3D Mesoporous Conch-like Co3O4 Nanostructure Arrays for High-Performance Supercapacitors

Hierarchical mesoporous conch-like Co3O4 nanostructure arrays with the thickness of a few nanometers supported on Ni foam substrate have been fabricated by a hydrothermal approach together with a post-annealing treatment. The highly ordered three-dimensional (3D) nanostructure offers numerous advantages duo to the desired properties of macroporosity, including enhanced mass transport for the electrolyte flow, thereby reducing the device resistance and faster the reaction kinetics. Such unique nanoarchitecture exhibits remarkable electrochemical performance with high capacitance and desirable cycle life. When evaluate as an electrode material for supercapacitors, the Co3O4 nanostructure arrays (NCAs) electrode is able to deliver high areal capacitance of 4.11 F cm(-2) at a current density of 5 mA cm(-2) in 2 M NaOH aqueous solution. The electrode also exhibits excellent cycling stability by retaining 93% of the maximum capacitance after 5000 charge-discharge cycles. The fabrication strategy presented here is facile, cost-effective, and can offer a new pathway for large-scale energy storage device applications. (C) 2014 Elsevier Ltd. All rights reserved.