Preparation Of Titanium-based Materials And Their Application In Lithium Ion Batteries

With the growing energy demand and increasing environmental pollution,the development and utilization of energy have drawn more and more attention.In this context,it has become an important topic to look for efficient,safe,environment friendly energy storage devices.Lithium ion batteries have become a hotspot in the field of electrochemical energy storage devices due to their high specific energy and environmentally benign nature.Titanium oxide(TiO2)has been found to be one of the good candidates as a lithium-ion battery material because its a small volume expansion(<3%)during the lithium-ion insertion/extraction process.In addition,TiO2 exhibits a relatively high lithium ion insertion voltage,which can effectively avoid the formation of lithium dendrite.These features render it a promising anode material for large-scale and long-life energy storage batteries.However,bulk anatase TiO2 normally possesses a practical specific capacity of 168 mAh/g,which is about half of the theoretical capacity of TiO2 materials(335 mAh/g).In addition,TiO2 has a poor electrical conductivity,which may restrict its electrochemical performance for high power batteries.In this paper,we prepared the TiO2 flexible thin film electrode material firstly,which is a promising anode material for lithium ion batteries.The TiO2 flexible electrode after calcination could retain a capacity of 107.0 mAh/g with high capacity retention of 62.2%after 300 cycles at a high current density of 400 mA/g.Because of its 3D network structure in large scale,it is beneficial to be used as the carrier of other materials.At the same time,it has good cycle performance.If we combine TiO2 with material of the poor cycle performance and high capacity together,we may get composite materials with high capacity and good cycling performance.This paper tries to obtain MoS2?TiO2 and SnO2@TiO2 with excellent electrochemical property.TiO2 hybrid nano composites are promising electrode materials for lithium-ion batteries because of the large specific capacity and excellent electrochemical performance.In this work,MoS2@TiO2 hybrid flexible electrodes have been successfully synthesized via a facile hydrothermal process.Encouragingly,when being evaluated as an anode material for LIBs,the MoS2@TiO2 flexible electrode after second calcination could retain a capacity of 361.5 mAh/g with high capacity retention of 88.0%after 300 cycles at a high current density of 800 mA/g.Such good performance may be derived from TiO2 nanowires with 3D nano-network structure,the well-dispersed MoS2 nanoparticles and the close connection between TiO2 and MoS2 after the second calcinationWhen the SnCl4 solution is sprayed on the TiO2 flexible electrode material,the SnO2@TiO2 composite electrode material with the best electrochemical performance can be prepared by calcination.The SnO2@TiO2 flexible electrode after calcination could retain a capacity of 449.4 mAh/g with high capacity retention of 74.2%after 100 cycles at a high current density of 400 mA/g.