锂离子电池TiNb2O7负极材料的嵌脱锂机理、结构设计与可控制备

项目名称： 锂离子电池TiNb2O7负极材料的嵌脱锂机理、结构设计与可控制备

项目编号： No.51472065

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 程新群

作者单位： 哈尔滨工业大学

项目金额： 80万元

中文摘要： 锂离子电池在电动车等领域的应用需要高功率、高安全性的负极材料，然而，常用的石墨材料高功率性能较差，Li4Ti5O12高倍率充放电性能和循环稳定性优异，但是其较低的比容量限制了电池的能量密度，新型的ReO3结构TiNb2O7具有良好的倍率性能和更高的比容量，但是也存在导电性和稳定性差等缺点，目前对其研究还较少。本项目通过理论计算，结合电化学嵌脱锂过程中LixTiNb2O7的结构变化及物理化学性质表征、以及电化学性能研究，揭示锂离子在TiNb2O7中的存储与传输机理；同时引入原位红外光谱和质谱方法表征材料在循环过程中的界面反应，结合非现场的结构分析手段研究其循环稳定性，提出材料的改性方法；以锂离子传输与存储机理为基础，从微尺度调控TiNb2O7材料形貌与结构及改性，提升大倍率充放电性能。上述研究结果将为TiNb2O7负极材料的研发提供理论指导与实验帮助，并完善材料的电化学理论。

中文关键词： 锂离子电池；负极材料；氧化物；嵌脱锂机理；可控制备

英文摘要： With the wide application of lithium ion batteries in electric cars and other fields, it is important to find a high power and security anode material for lithium ion batteries. The rate performance of graphite materials used in commercial lithium ion batteries were poor, Li4Ti5O12 has been suggested as a promising alternative to graphite for its excellent high rate properties and cycle stability, however, its low specific capacity leads to low energy density of battery using this material, which limits its application in batteries. Novel anode material TiNb2O7 with a structure ReO3 has excellent rate performance and higher specific capacity, however, there are still many challenges to overcome, such as its poor electronic conductivity and poor cycle stability. Up to now, only few researches were done on , so further studies still need to be done. In this project, the mechanism of diffusion and storage of lithium ions will be revealed through theoretical calculation，combining with structure change of LixTiNb2O7 during the process of electrochemical Li insertion/extraction, the characterization of physical and chemical properties, as well as the study of electrochemical performance. In-situ infrared spectroscopy and mass spectrometry method will also be introduced into the characterization of interface reactions of TiNb2O7 materials, and ex-situ structure analysis method will be used to study the cycle stability. Modification methods for TiNb2O7 material will be proposed. Based on the mechanism of lithium ion transport and storage, we intend to regulate the morphology and structure of TiNb2O7 material in microscale, thereby improving the high-rate charge and discharge properties. This research will provide theoretical and experimental guidance for the study of TiNb2O7, and improve the electrochemical theory of TiNb2O7 materials.

英文关键词： lithium ion battery;anode material;oxide;machnism of lithium insertion and de-insertion;controllable preparation