Improved electrochemical properties of Sn-doped TiO2 nanotube as an anode material for lithium ion battery

Anatase TiO2 nanotube was doped with different contents of Sn (3, 5, and 7 at.%) through sol-gel method and subsequent hydrothermal process. X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET), and Hall effect measurement are utilized to characterize the structures, components, chemical environments, morphologies, specific areas, and electronic conductivities of the samples. The investigation in cycling performances demonstrates that 5 at.% Sn-doped TiO2 nanotube exhibits the best cycling stability, with specific capacity of 386 mAh g(-1) and coulombic efficiency of 99.2 % after 50 cycles at 0.1 C, much higher than those of the other Sn-doped samples and pristine TiO2 nanotube. The improved electrochemical performances of Sn-doped TiO2 nanotube are attributed to the increase of electronic conductivity and therefore enhance the reversible capacity of the material.