Mechanism Study of Lithium Ion Insertion into Titania Nanotubes

Abstract

Lithium-ion batteries (LIBs) are widely used to power portable devices, microelectronics, and vehicles. With many advantages such as high surface area and improved charge transport, self-supported 3-D nanostructured metal oxides are promising electrode materials for LIBs and their impact is particularly significant when considering the miniaturization of energy storage systems and the development of 3D microbatteries [1-3]. During this talk, it will be presented the utilization of self-organized titania nanotubes (TiO2nts) as negative 3D self-supported electrode for Li-ion microbatteries [4–8]. This 3D nanostructured electrode is quite interesting owing to better electrochemical performance in terms of kinetics and stability. Then, the fabrication of a all-solid-state battery composed of vertical arrays of TiO2nts as anode, a polymer thin film as electrolyte, and a high potential cathode material like LiNi0.5Mn1.5O4 (LNMO) layer will be shown [9] and the current approaches developed to achieve the fabrication of a full 3D microcell will be highlighted. Particularly, the conformal electrodeposition of polymer electrolyte into titania nanotubes [10] will be discussed as well as the improvement of the electrochemical performance. Finally, the Li+ insertion into anatase titania nanotubes employing PEO-based polymer electrolyte studied by cyclic voltammetry and chronoamperometry will be presented. The study shows that the Li+ storage in the anatase is dominated by the bulk diffusion (into the lattice) and the increasing contribution of the pseudo-capacitive effect with faster kinetics We also report that the chemical diffusion of Li+ in self-organized titania nanotubes is around 2 × 10-16 cm2 s-1 suggesting that the use of a solid electrolyte does not alter the charge transport in the nanostructured electrode.