Room-temperature synthesis of CuO/graphene nanocomposite electrodes for high lithium storage capacity

A facile approach for the synthesis of hybrid nanocomposite electrodes comprising pine-nut-shaped cupric oxide (CuO) particles and electrolytically exfoliated conducting graphene nanosheets (GNSs) for lithium ion battery applications is demonstrated. The GNSs were initially dispersed in aqueous solution, and then, Cu(OH)₂ was synthesized by the reaction of CuSO₄·5H₂O, NH₄OH, and NaOH. In the subsequent chemical reduction process, a controlled amount of hydrazine hydrate (N₂H₄·H₂O) was added to the reaction mixture to obtain the CuO/GNS nanocomposite. Information about the phase, surface properties, and morphology of the CuO and CuO/GNS composite was obtained by X-ray diffraction, Brunauer-Emmett-Teller surface analysis, field-emission scanning electron microscopy, and high-resolution transmission electron microcopy. The electrochemical performance of the nanocomposite was evaluated by cyclic voltammetry and galvanostatic cycling. The nanocomposite synthesized by this method had a uniform morphology without aggregation and showed enhanced electrochemical performances.