CoO-Co₃O₄ heterostructure nanoribbon/RGO sandwich-like composites as anode materials for high performance lithium-ion batteries

CoO-Co₃O₄ heterostructure nanoribbons were successfully sandwiched between reduced graphene oxide (RGO) nanosheets through a facile solvothermal method and sintering process, which used directly as the anode material for lithium ion batteries. The as-prepared ultrathin CoO-Co₃O₄ nanoribbon/RGO sandwich-like nanostructures (CoO-Co₃O₄-RGO) delivers a reversible capacity of 994 mAh g⁻¹ at a current density of 100 mA g⁻¹ after 200 cycles. Even at a high charge-discharge rate of 1000 mA g⁻¹, CoO-Co₃O₄-RGO still demonstrate a reversible capacity of 395 mAh g⁻¹ after 500 cycles. The rate capability of CoO-Co₃O₄-RGO evaluated by the ratio of capacity at 100, 200, 500, 1000, 2000, 5000 and 100 mA g⁻¹ after each 10 cycles was about 1210, 1060, 890, 730, 578, 392 and 915 mAh g⁻¹, respectively. The greatly enhanced performances for CoO-Co₃O₄-RGO may be ascribed to the synergistic effects: The multicomponent generates hybridizing advantages; The mutual influence of both CoO-Co₃O₄ nanoribbons and RGO nanosheets decreases the aggregation; The two-dimensional (2D) nanoribbons with the short lithium ion diffusion and 2D RGO sheets as conductive network built an efficient three dimensional (3D) storage active material.