TiO2 nanotubes wrapped with reduced graphene oxide as a high-performance anode material for lithium-ion batteries

摘要

Through electrostatic interaction and high-temperature reduction methods, rGO was closely coated onto the surface of TiO2 nanotubes. Even at a high temperature of 700 °C, the nanotube morphology of TiO2 (anatase) was preserved because of the assistance of rGO, which provides a framework that prevents the tubes from breaking into particles and undergoing a phase transformation. The rGO/TiO2 nanotubes deliver a high capacity (263 mAh g⁻¹ at the end of 100 cycles at 0.1 A g⁻¹), excellent rate performance (151 mAh g⁻¹ at 2 A g⁻¹ and 102 mAh g⁻¹ at 5 A g⁻¹), and good cycle stability (206 mAh g⁻¹ after 500 cycles at 0.5 A g⁻¹). These characteristics arise from the GO/TiO2 nanotubes’ advanced structure. First, the closely coated rGO and Ti³⁺ in the tubes give rise to a high electro-conductivity of the nanotubes. Additionally, the Li⁺ ions can rapidly transfer into the electrode via the nanotubes’ empty inner diameter and short tube wall.