Binder-free combination of large area reduced graphene oxide nanosheets with Cu foil for lithium ion battery anode

•Binder-free combination of RGO with Cu foil was designed and achieved.•Large area RGO nanosheets did tightly attach onto the surface of Cu foil.•Binder-free integration was helpful for high conductivity of RGO/Cu electrode.•RGO/Cu electrode delivered satisfying electrochemical performances.•Tiny residual O-containing groups also contributed into Li-storage capacity.

Binder-free combination of large area reduced graphene oxide (RGO) nanosheets with Cu foil was designed and achieved via one-step facile electro-reduction reaction. The obtained composite RGO/Cu foil electrode were studied in terms of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), selected area electron diffraction (SAED), Raman, galvanostatic charge/discharge, AC impedance and cyclic voltammetry (CV). As expected, large area RGO nanosheets with micron order of magnitude successfully formed and tightly combined with Cu foil without any additional polymer binders. Furthermore, RGO/Cu foil electrode delivered a reversible discharge capacity of 870.3 mAh/g after 110 cycles, indicating satisfactory cyclic stability and rate performance. High Li-storage activity, eminent conductivity and tight binder-free integration of RGO nanosheets with Cu foil current collector should be responsible for high electrochemical performances.

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