The spinel-type Co3O4 with a dendritic nanostructure is prepared via homogeneous co-precipitation method in the presence of oxalic as complex agent. The special structure was characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis, which show that the precursor can be transformed into dendritic crystal Co3O4 by calcining at 500 °C for 2 h with a diameter of 20–50 nm. Such a three-dimensional interconnected structure used as an anode material for lithium-ion batteries shows that the discharge specific capacity still remains at 951.7 mA h g−1 after 100 cycles at a current density of 100 mA g−1. Furthermore, this material also presents a good rate performance; when the current density increases to 1,000, 4,000, and 8,000 mA g−1, the reversible capacity can render about 1,126.2, 932.3, and 344.2 mA h g−1, respectively. The excellent electrochemical performance is mainly attributed to the dendritic nanostructure composed of interconnected Co3O4 nanoparticles.
