NiO-C nanocomposite was prepared by a spray pyrolysis method using a mixture of Ni(NO3)(2) and citric acid solution at 600 degrees C. The microstructure and morphology of the NiO-C composite were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) mapping, and thermogravimetric analysis (TGA). The results showed that the NiO nanoparticles were surrounded by amorphous carbon. Electrochemical tests demonstrated that the NiO-C nanocomposites exhibited better capacity retention (382 mAh g(-1) for 50 cycles) than that of pure NiO (141 mAh g(-1) for 50 cycles), which was also prepared by spray pyrolysis using only Ni(NO3)(2) as precursor. The enhanced capacity retention can be mainly attributed to the NiO-C composite structure, composed of NiO nanoparticles surrounded by carbon, which can accommodate the volume changes during charge-discharge and improve the electrical conductivity between the NiO nanoparticles. (C) 2009 Elsevier B.V. All rights reserved,