Synthesis and superior anode performance of TiO2@reduced graphene oxide nanocomposites for lithium ion batteries

Abstract

Herein, we report the synthesis of TiO₂-reduced graphene oxide composite (termed as TGC) nanostructures using tetrabutyl titanate as the titanium source via a solvothermal route. The TGC nanostructures were characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and adsorption–desorption isotherms for nitrogen measurements. The TGC was used as the anode of lithium ion batteries for investigation. The hybrid nanocomposite exhibited remarkable improvement in lithium ion insertion/extraction behaviour compared with TiO₂, which showed an initial irreversible capacity and a reversible capacity of 386.4 and 152.6 mAh g⁻¹ for TGC after 100 cycles at a high charge rate of 5 C (1000 mA g⁻¹), compared to 69.5 and 9.7 mAh g⁻¹ for TiO₂, respectively. The enhanced electrochemical performance of TGC is attributed to the increased conductivity in the presence of reduced graphene oxide in TGC, the small size of the TiO₂ particles in TGC, which can shorten the transport paths for both Li⁺ ions and electrons, and the enlarged electrode–electrolyte contact area, leading to more electroactive sites in TGC.