Abstract: The Co₃O₄/acetylene black composite anodes were successfully prepared by combination of oxalate precipitation and pyrolysis of the precipitate. The composite and its precursor were characterized by thermo-gravimetric analysis(TGA), differential thermal analysis(DTA), X-ray diffractometry(XRD), scanning electronic microscopy(SEM) and electrochemical measurements. The effects of carbon content and calcination temperature on properties of the composite were investigated in detail. The cycling performance of the Co₃O₄ anode is improved remarkably by the addition of carbon. As the calcination temperature rises in the range of 300−450 ℃, the crystallinity of the composites increases, but their reversible capacity and cycling stability decrease. Being charged/discharged at a current density of 0.1C rate, the optimized Co₃O₄/C composite anode shows a large initial reversible capacity of 757 mA∙h/g, and a capacity of 743 mA∙h/g is observed after 10 cycles.

Key words: lithium ion batteries; anode; Co₃O₄; composite