Molten hydroxides synthesis of hierarchical cobalt oxide nanostructure and its application as anode material for lithium ion batteries

Hierarchical Co₃O₄ nanostructure is synthesized via a self-assembled process in molten hydroxides. The morphologies, crystal structures and the phase transformation processes are analyzed by field-emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. As an anode material for lithium ion batteries, the hierarchical Co₃O₄ exhibit an initial capacity of 1336 mAh g ^-1 and a stable capacity of 680 mAh g^-1 over 50 cycles. More importantly, high rate capability is obtained at different current densities between 140 and 1120 mA g^-1. The improved electrochemical performance of Co₃O₄ could be attributed to the unique hierarchical nanostructure.