Double-Carbon Enhanced TiO2 Nanotubes as Highly Improved Anodes for Sodium-Ion Batteries

TiO2, with low cost, highly environmental benignity, and high safety, has been considered to exhibit great potential as an advanced anode material for sodium ion batteries (SIBs), although slow electron/ion transport hinders its development. Here, we find the composite of thin-walled TiO2 nanotubes with a double carbon coating by hydrothermal reaction and calcination, which effectively improves the structural stability and promotes electron transport. The composite material of TiO2/rGO@NC delivers the first charge specific capacity of 245.8 mA h g(-1) at 0.02 A g(-1), along with 118.7 and 91.7 mA h g(-1) at high current densities of 2.5 and 5 A g(-1). Simultaneously, it can still offer 135.8 mA h g(-1) over 500 cycles at the current density of 1 A g(-1). The remarkable electrochemical performance, combining with its own properties, demonstrates that it can be used as a hopeful anode material for superior performance SIBs.