By subjecting amorphous titanium dioxide (TiO 2 ) colloidal spheres as scaffold to a two-step external template-free hydrothermal treatment, anatase TiO 2 hollow spheres with an average diameter of 410nm and shell thickness of 65 nm were successfully yielded. Such hollow TiO 2 nanostructures possessed 10 large surface area, abundant active sites and reduced Li ion diffusion path, and thus was highly favorable for use in TiO 2 -based lithium ion battery (LIB). Electrochemical measurements revealed that asprepared TiO 2 hollow spheres exhibited specific discharge capacities of 296, 185, 118, 66 and 37mAhg -1 at 0.1C, 1C, 2C, 5C and 10C, respectively. This is in sharp contrast to those much lower values obtained in TiO 2 solid nanoparticles (i.e., 182, 119, 81, 43 18 mAhg -1 at discharge rates of 15 0.1C, 1C, 2C, 5C and 10C, respectively). Interestingly, TiO 2 hollow spheres showed a large irreversible capacity loss and relatively low cycling performance due to the residual chemisorbed water in TiO 2 and hydroxyl groups present on the TiO 2 surface. A solid electrolyte interface (SEI) layer composed primarily of Li 2 CO 3 , lithium alkyl carbonates and organic phosphates was thus formed on the surface of hollow TiO 2 spheres, thereby leading to an increased internal cell 20 impedance and the decreased rate and cycling performance. The subsequent high-temperature annealing effectively removed chemisorbed water and hydroxyls on the TiO 2 surface. As a consequence, annealed TiO 2 hollow spheres rendered markedly improved rate stability and cycle performance in the resulting TiO 2 -based LIBs. The specific discharge capacities at rates of 5C and 10C were 77mAhg -1 and 50mAhg -1 , which are much larger than those obtained from as-prepared TiO 2 hollow 25 spheres. Moreover, compared to only 42.1% for as-prepared hollow TiO 2 spheres, a capacity retention as high as 93.5% over 200 cycles at 1C was achieved for annealed hollow TiO 2 spheres. 60