Polyaniline/multi-walled carbon nanotubes (MWNTS) composites were prepared by an in situ chemical oxidative polymerization method and were used as the cathode materials for rechargeable lithium batteries. The structure and morphology of the as-synthesized samples were investigated by X-ray diffraction (XRD) and transmission electron microscope (TEM). The charge/discharge property, coulombic efficiency, cyclic voltammetry and ac impedance spectroscopy of the as-prepared samples were also examined in detail. It was confirmed that MWNTs had an obvious effect on the electrochemical performance of polyaniline. The results could be attributed to the excellent electronic and electrochemical properties of MWNTs. (c) 2008 Elsevier B.V. All rights reserved.