The powders of LiCoO2/Ag composite were prepared by thermal decomposition of AgNO3 added to commercial LiCoO2 powders and were examined on their electrochemical performance with particular attention to their high-rate charge–discharge cycling properties as cathode materials for lithium-ion batteries. X-ray diffraction (XRD), scanning electron microscopy (SEM), ac impedance, CV and charge–discharge cycles were used to evaluate the LiCoO2/Ag composite powders. It was shown that the Ag additive effectively increased the electrical conductivity of the LiCoO2 and decreased the polarization of cathode, and marvellously improved the high-rate discharge capacity and cycling stability of LiCoO2.