GeO2 decorated reduced graphene oxide as anode material of sodium ion battery

GeO2-reduced graphene oxide (RGO) composites were prepared by a simple freeze-drying method. After thermal annealing in N2 atmosphere at 450 °C for 2 hours, the composites were examined as anode materials of sodium ion batteries for the first time. Their morphology, structure and electrochemical performance were characterized by field-emission scanning electron microscopy, X-ray diffraction, N2 adsorption-desorption isotherm, cyclic voltammetry and electrochemical impedance spectroscopy, respectively. A maximum specific capacity of 330 mAh g−1 can be achieved after 50 galvanostatic charge-discharge cycles at a current density of 100 mA g−1 by tuning the RGO content in the composites. Even after 650 cycles at a high current density of 1 A g−1, the specific capacity can still maintain at 153.7 mAh g−1, demonstrating the excellent Na ion storage properties of the GeO2-RGO composites.

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