An Investigation on the Effect of Li-Ion Cycling on the Vertically Aligned Brookite TiO2 Nanostructure

We reported the investigation on the effect of Li-ion cycling on the vertically aligned brookite (beta) TiO2 nanorods coated on Cu substrate as a Li-ion battery electrode. The vertically grown beta-TiO2 nanorods synthesized over large area array using hot filament metal vapor deposition (HFMVD) technique were similar to 19 nm in diameter with well-defined textural boundaries. X-ray photoelectron spectroscopy revealed the formation of stoichiometric beta-TiO2 nanorods and Raman spectroscopy revealed the formation of pure brookite phase, and not accompanied by the anatase and/or rutile phases. The beta-TiO2 nanorods showed good electrochemical performance with the appearance of the potential plateau at 1.8 and 2.1 V during Li insertion and desertion. The initial discharge/charge capacities of similar to 81 (52 mu Ah cm(-2) mu m(-1)) and similar to 72 mAhg(-1) (45 mu Ah cm(-2) mu m(-1)) obtained at the current density of 33 mAg(-1) were retained further to similar to 62 mAhg(-1) (40 mu Ah cm(-2) mu m(-1)) until the 200th cycle. The exceptional cycling performance of beta-TiO2 nanorods with a high coulombic efficiency of greater than similar to 98% confirms their potentials as a competent electrode for Li-ion rechargeable batteries.