A facile one-pot synthesis of TiO₂/nitrogen-doped reduced graphene oxide nanocomposite as anode materials for high-rate lithium-ion batteries

TiO₂/nitrogen-doped reduced graphene oxide nanocomposite (TiO₂/N-RGO) is prepared via a facile one-pot hydrothermal method, in which ethylene glycol and ammonia are used as the reducing agent and nitrogen precursor, respectively. The reducing and nitrating process was accompanied by the generation of TiO₂ nanoparticles. Various state-of-the-art techniques, including field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, thermogravimetric (TG) analysis and X-ray photoelectron spectroscopy (XPS) are performed to characterize the morphologies, structures and compositions. The introduced nitrogen atoms into graphene skeleton could enhance nucleation and growth kinetics and thus resulted in the nano-sized TiO₂ uniformly anchoring on the N-RGO surface. Electrochemical tests show that the TiO₂/N-RGO nanocomposite exhibits superior rate capability and outstanding capacity retention. The reversible capacity of the TiO₂/N-RGO electrode is up to 126.8 mAh g^-1 at 10 C and still remains at 118.4 mAh g^-1 after 100 cycles. The excellent electrochemical performances can be attributed to electronic structure modification of graphene, which promoting intrinsic electron transfer between the host substrate and electroactive materials. Moreover, the high contact area between the electrolyte/electrode facilitates the transportation of electrolyte ion into the inner region of the electrode. Therefore, the TiO₂/N-RGO nanocomposite can be a promising candidate anode material for high-rate lithium ion batteries.