Composites of porous Co₃O₄ grown on Li₂MnO₃ microspheres as cathode materials for lithium ion batteries

The core-shell structure of Co₃O₄@Li₂MnO₃ was prepared by a facile hydrothermal method following heat treatment at 300 °C. The outer shell is porous and makes the diffusion of Li⁺ ions to the inner shell easier. The synergetic effect between the core and shell shows that the Co₃O₄ shell in the composite serves as a host to react with lithium oxide removed from the Li₂MnO₃ core during the initial charging process, which eliminates the huge irreversible capacity loss of Li₂MnO₃. As the cathode material for lithium ion batteries, the composite exhibits an attractive discharge capacity of 178 mA h g^-1 with little irreversible capacity loss in the voltage range of 2.0-4.8 V. Its cycling performance is stable without any drastic capacity fading when cycling in the high voltage range of 2.0-4.6 V.