NiO/Graphene Nanocomposite as Anode Material for Lithium-Ion Batteries

In this study, NiO/graphene nanocomposite was prepared by a hydrothermal route followed by heating under N-2, and its electrochemical performance was studied as a potential anode for lithium ion batteries. The NiO/graphene nanocomposite is systematically characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectra, and X-ray photoelectron spectroscopy techniques. It was found that the NiO nanoparticles (about 30-50 nm in size) with a narrow size distribution are uniformly anchored on graphene sheets. Compared to bare NiO, the NiO/graphene nanocomposite shows improved electrochemical performance with large reversible capacity, excellent cyclic performance, and good rate capacity. The reason is that the good conductive graphene sheets act as buffer to accommodate the volume changes and as a separator to prevent NiO nanoparticles from aggregating during Li charge/discharge process. Electrochemical impendance spectroscopy (EIS) was measured in order to analysis the influence of graphene sheets on the electrochemical properties of NiO.