Synthesis and electrochemical properties of SnO2-CuO nanocomposite powders

SnO2-CuO nanocomposite powders were prepared by chemical coprecipitation method using SnCl4 5H2O, NH3 H2O and Cu(NO3).3H2O as raw materials. The powders were characterized by thermogravimertric(TG) analysis and differential thermal analysis(DTA), X-ray diffraction(XRD), and scanning electron microscope(SEM). The electrochemical properties of SnO2-CuO and undoped SnO2 powders as anode materials of lithium ion batteries were investigated comparatively by galvanostatic charge-discharge experiments and AC impedance. The results show that SnO2-CuO nanocomposite powders with the average particle size of 87 nm can be obtained by this method. The structure of SnO2 does not change with the introduction of CuO, but the average particle size of nano-SnO2 decreases. SnO2-CuO nanocomposite powders show a reversible capacity of 752 mA h/g and better cycleability compared with nano-SnO2. The capacity retention rates after 60 cycles of nano-SnO2-CuO and SnO2 are 93.6% and 92.0% at the charge-discharge rate of 0.1 C, respectively, which suggests that the introduction of CuO into SnO2 can improve the cycleability of nano-SnO2.