Eco-friendly synthesis of rutile TiO2 nanostructures with controlled morphology for efficient lithium-ion batteries

An environmentally friendly, scalable, and template-free route based on a simple hydrothermal process has been developed for preparing the rutile TiO2 nanostructures by using titanium oxysulfate (TiOSO4) as the titanium precursor under an acidic condition. Notably, two kinds of TiO2 nanostructures with different morphologies are obtained only by simply adjusting the solvent. The as-prepared hierarchical TiO2 nanostructures are constructed by numerous nanobundles or nanoneedles, corresponding to water and ethylene glycol as the solvent, respectively, designed as H-TiO2 and E-TiO2. The nucleation and crystal growth of rutile TiO2 products can be dominated with the help of hydrochloric acid, resulting in a uniform size and controllable morphology. The achieved products can be applied as the excellent anode material for lithium-ion batteries. Benefiting from the large specific surface area, small particle size and loosely hierarchical nanostructure, E-TiO2 product exhibits superior electrochemical properties including high reversible capacity, long cycling performance and good rate capability. Significantly, it shows a high reversible capacity up to 190 mA h g(-1) after 200 cycles at a high current rate of 0.6 C, and a stable capacity of 85.4 mA h g(-1) can also be delivered at an extremely high rate of 10 C. (C) 2016 Elsevier B.V. All rights reserved.