Microwave-assisted synthesis of Co3O4–graphene sheet-on-sheet nanocomposites and electrochemical performances for lithium ion batteries

•Co3O4–graphene nanocomposites are prepared by microwave irradiation method.•Co3O4 nanosheets exhibit porous structure with the pore sizes of 3–6 nm.•The porous Co3O4–graphene nanocomposites show excellent electrochemical performance.•Synergistic effects of Co3O4 and graphene improve the electrochemical performance.

Porous Co3O4 nanosheets anchored on graphene nanosheets were synthesized by microwave irradiation method. The obtained Co3O4–graphene sheet-on-sheet nanocomposite as an anode material for LIBs demonstrates a high initial discharge capacity of 1359.6 mAh g−1 with a Columbic efficiency of 72.7% at a rate of 100 mA g−1. Moreover, a significantly enhanced reversible capacity of ∼1036.9 mAh g−1 is retained after 50 cycles, and the capacity can reincrease to 1068 mAh g−1 when the current density returns back to 100 mA g−1 after cycled at various rates for 50 cycles. The improved electrochemical performance is attributed to the unique architectures of the porous Co3O4 nanosheets and the incorporation of graphene nanosheets. Therefore, this nanocomposite is widely considered to be an attractive candidate as an anode material for next-generation LIBs.

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