Layered Li[Ni1/3Mn1/3Al1/3-xCox]O-2 (0 <= x <= 1/3) cathode materials are synthesized by a solvent evaporation method. Although XRD shows that Li[Ni1/3Mn1/3Al1/3]O-2 has no obvious impurity phase, it has poor electrochemical properties. To improve its capability, part of Al in Li[Ni1/3Mn1/3Al1/3]O-2 compound is replaced by Co in this study. The samples are characterized by X-ray diffraction (XRD). scanning electron microscope (SEM) and charge-discharge test. The results indicate that the introduction of Co has a large influence on the morphology, structure and electrochemical performances of the samples, which become more excellent with an increase of Co content in compounds. Meanwhile, the high-temperature behavior of the samples is also investigated. (C) 2011 Elsevier Ltd. All rights reserved.