A nanocomposite material (SnO2Co3O4) has been synthesized as an anode material for lithium-ion batteries by the molten salt method. Characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed that the composite has a small particle size. The electrochemical performance was examined, including the charge–discharge and cycling properties. The experimental results showed that the sample containing the highest amount of Co3O4 compound exhibited a specific capacity of 355 mAh g−1 after 40 cycles, with cycling at 70 mA g−1 (35.2% higher than for the sample containing a lower amount of Co3O4). It seems that increasing the amount of Co3O4 can give good capacity retention and high specific capacity.