Layer-by-layer self-assembly of graphene-like Co3O4 nanosheet/graphene hybrids: Towards high-performance anode materials for lithium-ion batteries

• Graphene-like Co3O4 nanosheet/graphene hybrids have been successfully synthesized.
• The Co3O4/graphene hybrids exhibit a very high reversible lithium storage capacity.
• The Co3O4/graphene hybrids also exhibit an ultrahigh rate capability.

We have successfully synthesized graphene-like Co(OH)2 and fabricated sandwich-like Co(OH)2/graphene hybrids by the electrostatic self-assembly. After annealing at low temperatures, we further fabricated Co3O4 nanosheet/graphene hybrids, in which the thickness of graphene-like Co3O4 nanosheets is only ∼5 nm. The as-prepared product exhibits a very high reversible lithium storage capacity up to 982.6 mAh g−1 after 50 cycles, while pure Co3O4 nanosheets only show the discharge capacity of 108 mAh g−1 after 50 cycles. Moreover, in comparison with the reported results, it exhibits an ultrahigh rate capability of 209.7 mAh g−1 at 5000 mA g−1. The greatly improved electrochemical performances may be ascribed to the sandwich-like structure of ultrathin Co3O4 nanosheet/graphene.