Synthesis of interconnected mesoporous ZnCo 2 O 4 nanosheets on a 3D graphene foam as a binder-free anode for high-performance Li-ion batteries.

Interconnected mesoporous sheet-like ZnCo 2 O 4 nanomaterials directly grown on a three-dimensional (3D) graphene film (GF) coated on Ni foam (NF) have been successfully synthesized via an effective chemical vapor deposition (CVD) method combined with a subsequent hydrothermal route. When the ZnCo 2 O 4 @3DGF@NF composite material with a high surface area of 46.06 m 2 g -1 is evaluated as a binder-free anode material for lithium ion batteries, it exhibits a superior electrochemical performance with a high discharge capacity (1223 mA h g -1 at a current density of 500 mA g -1 after 240 cycles), and an excellent reversibility (coulombic efficiency of 97-99%). Such an outstanding electrochemical performance may be attributed to its unique mesoporous sheet-like nanostructure with a 3DGF supporting, which can facilitate the electrolyte penetration and accelerate the ion/electron transport, as well as buffer the volume variation during charge/discharge processes.