Mechanochemically induced transformation of CoO(OH) into Co3O4 nanoparticles and their highly reversible Li storage characteristics

A simple synthetic method for the mechanochemically induced transformation of cobalt oxyhydroxides (CoO(OH)) into cobalt oxide (Co3O4) nanoparticles is developed. Using this method, extremely small and well-dispersed Co3O4 (3–5 nm) nanoparticles are synthesized and their use as a high-performance anode for Li-ion batteries is evaluated. The Co3O4 nanoparticle electrode shows excellent electrochemical performances such as a highly reversible capacity of 1023 mA h g−1 with excellent cycling behavior over 100 cycles and a superior rate capability of 760 mA h g−1 at an extremely fast current rate of 3C. This simple mechanochemically induced transformation method for extremely small and well-dispersed cobalt oxide nanoparticles is highly applicable to the preparation of other metal oxide nanoparticles for obtaining highly reversible Li storage characteristics.