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

Abstract An environmentally friendly, scalable, and template-free route based on a simple hydrothermal process has been developed for preparing the rutile TiO 2 nanostructures by using titanium oxysulfate (TiOSO 4 ) as the titanium precursor under an acidic condition. Notably, two kinds of TiO 2 nanostructures with different morphologies are obtained only by simply adjusting the solvent. The as-prepared hierarchical TiO 2 nanostructures are constructed by numerous nanobundles or nanoneedles, corresponding to water and ethylene glycol as the solvent, respectively, designed as H-TiO 2 and E-TiO 2 . The nucleation and crystal growth of rutile TiO 2 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-TiO 2 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.