Controllable synthesis of TiO2hierarchical and their applications in lithium ion batteries

Abstract

In this article, TiO₂ has been successfully ^f_a in the Ti(SO₄)₂–CH₃COOH system via a simple hydrothermal method. The formation mechanism of the TiO₂ hierarchical nanostructures was also investigated in detail, which involved the complex reaction between Ti(SO₄)₂ and CH₃COOH, hydrolysis of the complex, nucleation and self-assembly of TiO₂ nanocrystals and anisotropic growth of these subunits. SO₄²⁻ plays an important role in the self-assembly of subunits. In addition, controllable synthesis of TiO₂ hierarchical nanostructures with tunable size can be realized just by changing experimental parameters, such as reaction time or Ti(SO₄)₂ concentration. When used as the anode in lithium ion batteries, these TiO₂ hierarchical nanostructures present much higher specific capacity and better rate performances than TiO₂ nanoparticles, which are attributed to the stability of the secondary-structure during the charge and discharge processes.