锂离子电池电极材料性能调控的界面效应研究

项目名称： 锂离子电池电极材料性能调控的界面效应研究

项目编号： No.11474216

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 刘恩佐

作者单位： 天津大学

项目金额： 86万元

中文摘要： 富锂正极材料、橄榄石型正极材料、金属氧化物负极材料等新型锂离子电池电极材料具有重要应用潜力，但是其稳定性、循环和倍率性能等需要改进，掺杂和石墨烯包覆是调控其电化学性能的研究热点；性能调控中，表面、晶界以及石墨烯包覆层与电极材料间界面起着重要作用，但界面对材料电化学性能的微观作用机制尚不清楚。本项目采用第一性原理计算系统研究富锂和橄榄石型正极材料、金属氧化物负极材料的表面、晶界、与石墨烯间界面，以及界面掺杂对体系电化学性能的影响；确立界面的稳定原子构型和电子结构，并结合实验对不同掺杂和石墨烯包覆材料的电化学测试，探明界面及界面掺杂影响电化学性能的微观机制，阐明电极材料性能调控的界面效应，并深入理解锂离子脱嵌过程中氧化还原过程。建立掺杂、石墨烯包覆与电极材料电化学性能间的关系，研究结果对于通过掺杂和包覆，实现界面调控，提高电极材料的电化学性能，设计优化新型锂离子电池电极材料具有重要指导意义。

中文关键词： 界面效应；电化学性能；锂离子电池电极材料；石墨烯；第一性原理计算

英文摘要： New-type electrode materials of Li ion batteries such as Li-rich and olivine cathode materials, metal oxide anode materials, etc. have great application potential.However, their stability, cycling and rate performances require to be further improved. Doping and graphene coating are the hot research topics to modulate the electrochemical performances of electrode materials. The surfaces and grain boundaries in electrode materials, as well as the interfaces between the electrode materials and the coating, play an important role in the control of the electrochemical performances of the electrode materials. The microscopic mechanism of the interface influence on the electrochemical properties is a scientific problem urgent to be solved. In this project, we will focus on the Li-rich and olivine cathode materials and metal oxide anode materials to systematically study the effects of surfaces and grain boundaries of electrode materials and the interfaces between the electrode materials and graphene, as well as the dopants at the interface, on the electrochemical properties of the electrode materials, using first-principles calculations. The atomic structures of the interfaces will be obtained and the electronic structures of the systems will be analyzed. In combination with the electrochemical performance test of electrode materials with different dopants and graphene coating, the microscopic influence mechanism of the interface, as well as the dopants at the interface, on the electrochemical properites of the electrode materials will be made clear. The interface effects in the electrochemical performance modulation of the electrode materials will be elucidated. Furthermore, through this project, the redox processes during the Li ion intercalation and deintercalation will be comprehensively understood. Thus, the relationship of the electrochemical performances of the eletrode materials with doping and graphene coating is expected to be established, which will direct the optimization of sythesis conditions to control the doping and coating and to realize the interface modulation, and as a result, the eletrochemical performance of the electrode materials will be enhanced, and new-type electrode materials in Li ion batteries will be designed.

英文关键词： interface effect;electrochemical properties;electrode materials in Li-ion battery;graphene;first-principles calculations