CoO/Co3O4/graphene nanocomposites as anode materials for lithium-ion batteries

CoO/Co3O4/graphene nanocomposites were successfully synthesized through an easy, accessible method followed by annealing treatment. Graphene was used as the appropriate carrier to load CoO/Co3O4 nanoparticles because of its high surface area. The CoO/Co3O4/graphene nanocomposites were then tested as anode material for lithium-ion batteries (LIBs). Results showed that the nanocomposites led to high capacity, delivering initial discharge-charge capacities of 1093.4 and 825.3 mAh·g−1, with an initial coulombic efficiency of 75.5%. The nanocomposite electrode showed excellent rate capability and impressive cyclability, as well as a high reversible capacity of 695.4 mAh·g−1 after 70 cycles at a discharge-charge current density of 0.5 C (1 C = 890 mA g−1). The excellent electrochemical performance was ascribed to the CoO nanoparticles and graphene. By contrast, pristine Co3O4 can maintain only 339.7 mAh·g−1 after 70 cycles, indicating very poor cycling performance because of the huge volume change during cycling. These results revealed that the nanocomposites were excellent anode material for LIBs.