Supercapacitor application of nickel oxide-titania nanocomposites

Highly-ordered and well-separated titania nanotube array was prepared by a potentiostatic anodization process. The desired nickel oxide-titania (NiO-TiO2) nanocomposites were constructed through incorporating nickel hydroxide into titania nanotubes by a one-cycle or multi-cycle alternate electrodeposition-oxidation and then a thermal dehydration process. By means of the microstructure promotion from particulate to flower-like NiO-TiO2 nanocomposite, specific capacitances were accordingly increased from 26.9 to 46.3 mF cm(-2) and energy densities were also improved from 13.1 to 33.3 for mw s cm(-2) in a redox supercapacitor application at a potential window of 1.2 V. The flower-like nanocomposite could keep 92.3% of initial capacitance even after 1000 cycles, presenting high operation stability in a continuous charge-discharge process. The superior energy-storage performance of flower-like nanocomposite was mostly attributed to its highly accessible redox reaction sites of three-dimensional NiO on TiO2 nanotubes. (C) 2009 Elsevier Ltd. All rights reserved.