Fabrication of ZnO@TiO2 Core-Shell Nanotube Arrays as Three-Dimensional Anode Material for Lithium Ion Batteries

Abstract

[email protected]2 core-shell nanotube arrays are fabricated combining the anodization and atomic layer deposition techniques. In this process, thin ZnO layers are coated onto the inner wall surface of the TiO2 nanotubes. The novel three-dimensional material is directly used as anode for lithium ion batteries and exhibits excellent specific capacity, cycling performance, and rate capability. The enhanced electrochemical performance can be ascribed to the combination of high specific capacity of ZnO and the structural stability of TiO2 nanotube arrays. On one hand, the ZnO layer increases the areal capacity of TiO2 nanotube arrays from 74 to 170μAh cm-2 after 200 cycles. On the other hand, the special nanotubular structure not only buffers the volume change of ZnO during cycling and but also facilitates rapid ion diffusion.