Abstract: ZnO, a transition metal oxide, possesses a high theoretical capacity of 978 mAh·g^-1 as an anode for lithium batteries. However, its cycling stability and capacity retention still need to be improved. Therefore, ZnO/CuO microspheres modified with nitrogen-doped carbon-coating (ZnO/CuO/N-C) were synthesized using Cu-ZnSe microspheres as a template and dopamine hydrochloride as raw material. This synthesis strategy simultaneously achieves the conversion of active materials, construction of internal pore structure, and coating of external conductive carbon layer. The electrochemical properties of ZnO/CuO microspheres anode are greatly improved after the treatment of nitrogen-doped carbon-coating. The pyridine nitrogen, pyrrole nitrogen, and graphite nitrogen are formed after nitrogen-doped into ZnO/CuO microspheres, significantly increasing surface active sites and promoting ion electron transfer. A large number of defects are generated in the inner composites after carbon coating, advantageous for providing more active sites for surface redox reactions. The ZnO/CuO/N-C microspheres as anode material of Li-ion battery exhibit excellent electrochemical properties. They still display a high specific capacity of 1010.4 mAh·g^-1 at 0.1 A·g^-1 after 200 cycles. The specific capacity of ZnO/CuO/N-C microspheres anode could reach 447.1 mAh·g^-1 at a high current density of 1 A·g^-1 after 1000 cycles. The excellent rate performance is exhibited in the process of Li⁺ ions insertion, ascribed to a high contribution of pseudocapacitance. The improved electrochemical properties of ZnO/CuO/N-C microspheres can be ascribed to the following factors. The structural integrity of composites could maintain by buffering volume expansion after carbon-coating. The electrolyte infiltration and ion transport can be promoted due to the existence of internal pores. A high capacity is caused through the conversion and alloying reactions of between ZnO and CuO.

Key words: ZnO/CuO, N-doped carbon, microspheres, lithium-ion battery