CuO/C microspheres as anode materials for lithium ion batteries

► CuO/C composite microspheres have been successfully prepared by calcining the CuCl 2/resorcinol–formaldehyde gel in argon atmosphere followed by a subsequent oxidation treatment using H 2O 2 solution. ► CuO particles disperse homogenously inside the carbon aerogel microspheres. ► Carbon aerogel microspheres have the abilities of alleviating the pulverization, suppressing the aggregation, and enhancing the conductivity of the CuO particles. Therefore, CuO/C composite microspheres exhibit better electrochemical performance than that of pure CuO. CuO/C microspheres are prepared by calcining CuCl 2/resorcinol-formaldehyde (RF) gel in argon atmosphere followed by a subsequent oxidation process using H 2O 2 solution. The microstructure and morphology of materials are characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and transition electron microscopy (TEM). Carbon microspheres have an average diameter of about 2 μm, and CuO particles with the sizes of 50–200 nm disperse in these microspheres. The electrochemical properties of CuO/C microspheres as anode materials for lithium ion batteries are investigated by galvanostatic discharge–charge and cyclic voltammetry (CV) tests. The results show that CuO/C microspheres deliver discharge and charge capacities of 470 and 440 mAh g −1 after 50 cycles, and they also exhibit better rate capability than that of pure CuO. It is believed that the carbon microspheres play an important role in their electrochemical properties.