Mesoporous Co₃O₄ nanosheets-3D graphene networks hybrid materials for high-performance lithium ion batteries

Mesoporous Co₃O₄ nanosheets-3D graphene networks (3DGN) hybrid materials have been synthesized by combining chemical vapor deposition (CVD) and hydrothermal method and investigated as anode materials for Li-ion batteries (LIBs). Microscopic characterizations have been performed to confirm the 3DGN and mesoporous Co3O4 nanostructures. The specific surface area and pore size of the hybrid structures have been found similar to ~ 34.5 m²g^-1 and similar to ~ 3.8 nm respectively. It has been found that the Co₃O₄/3DGNs composite displays better LIB performance with enhanced reversible capacity, good cyclic performance and rate capability as compare with Co₃O₄/CNT and Co₃O₄ structures. Electrochemical impedance spectroscopy (EIS) results show that the addition of 3DGN not only preserves high conductivity of the composite electrode, but also largely enhanced the electrochemical activity of Co₃O₄ during the cycling processes. The improved electrochemical performance is considered due to the addition of 3DGNs which prevent the cracking of electrode. In addition, the large specific surface area and porous nature of the Co₃O₄ nanosheets are also very convenient and accessible for electrolyte diffusion and intercalation of Li⁺ ions into the active phases. Therefore, this combination can be considered to be an attractive candidate as an anode material for LIBs. © 2013 Elsevier Ltd. All rights reserved.