In this paper, the CuO@Ag core-shell structured nanocomposite were successfully fabricated, and the enhanced cycle stability was obtained. The thickness of Ag shell was adjusted by the usage of AgNO3. Results shown the CuO@Ag-3% (the molar ratio of CuO and AgNO3 is 1:0.03) composite material achieved the best electrochemical performance. The specific capacity of the CuO@Ag-3% material after 200 cycles reached 420 mAh/g at the current density of 0.2C, higher than the bare CuO of 138 mAh/g. In addition, the effect of Ag addition on the diffusion coefficient of Li+ was investigated. The diffusion coefficient of Li+ gained the highest in the discharge process of CuO@Ag-3% sample. The research proved that the improvement of the cycle stability of the CuO@Ag-3% sample can attribute to the improvement of lithium ion diffusion ability. (C) 2019 Elsevier B.V. All rights reserved.