Cobalt oxide-graphene nanocomposite as anode materials for lithium-ion batteries

Composites of Co3O4/graphene nanosheets are prepared and characterized by X-ray diffraction and scanning electron microscopy. Their electrochemical behavior as anode materials of lithium-ion rechargeable batteries is investigated by galvanostatic discharge/charge measurements and cyclic voltammetry. The composite is composed of Co3O4 nanorods (around 20-40 nm in diameter) and nanoparticles (around 10 nm in diameter) distributed within the graphene matrix. The specific capacity of the composite is higher than both Co3O4 and graphene nanosheets. The cycling stability of Co3O4 is obviously enhanced by compositing with graphene. After 100 cycles, the discharge and charge capacity of the composite is 1,005 and 975 mAh g(-1), respectively, and the irreversible capacity loss is less than 3%.