Abstract: TiO₂ core-shell nanostructures have been hydrothermally prepared through controlling hydrolysis rate of Ti⁴⁺ ions by urea and H₂O₂ in（NH₄）₂TiF₆ aqueous solution.Electrode materials were obtained by post-heating at 500 ℃.The structure， morphology，and electrochemical performance prepared materials were characterized by XRD，FESEM，and galvanostatic charge-discharge measurements and cyclic voltammetry.Result indicated that the products had well-defined morphologies， uniform sizes，and good dispersion.In comparison with commercial TiO₂ nanoparticles，core-shell structures had unique porous structures and excellent structural stability，thus exhibiting a superior cycle performance and rate capability.TiO₂ core-shell nanostructures can deliver a discharge capacity of 344 mA·h/g and 72 mA·h/g at 0.1C and 10C rates，respectively. Moreover，TiO₂ core-shell nanostructures delivered a high retained capacity about 80% at 1C after 100 cycles.

Key words: lithium ion batteries, TiO₂, electrochemical performance