In situ sodium chloride template synthesis of cobalt oxide hollow octahedra for lithium-ion batteries

A novel template synthesis route is developed to synthesize cobalt oxide hollow octahedra. The sodium chloride templates are formed in situ in the reaction system by controlling the supersaturation of sodium chloride in the N,N-dimethylformamide solution. Transmission electron microscopy indicates that the porous shells of hollow octahedra are composed of ultra small particles. Electrochemical tests show that the discharge capacity of the cobalt oxide hollow octahedra is about 965 mA h g−1 after 30 cycles at 0.2C.