双层界面膜成膜添加剂的设计与成膜机理研究

项目名称： 双层界面膜成膜添加剂的设计与成膜机理研究

项目编号： No.U1504211

项目类型： 联合基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 岳红云

作者单位： 河南师范大学

项目金额： 27万元

中文摘要： 提高动力锂离子电池的能量密度、安全性和耐久性是其大规模应用的前提，高电压正极材料的使用是提高锂离子电池能量密度的有效途径。本研究针对锂离子电池高电压正极材料与电解液易于发生界面反应而导致电池性能恶化的问题，采取理论计算和具体实验、测试技术相结合的方法，从密度泛函理论计算出发，结合线性扫描伏安法等电化学技术设计并优选高电压正极成膜添加剂，采用有机电氧化技术重现并制备界面膜，分析其成分、探讨成膜机理。本项目的特色之处在于，利用双电位成膜或组装高稳定性链尾，开发新型高稳定双层界面膜正极成膜添加剂。比较研究不同功能化手段形成的双层界面膜对电池性能的影响，探索制备高稳定性双层界面膜添加剂的便捷途径。完成新型高电压电解液在半电池及全电池中的全性能应用评估和优化，考察其对电池循环性能、倍率性能及安全性的影响规律。最终实现基于高电压正极材料的高能量密度动力电池性能的整体提升。

中文关键词： 锂离子电池；电解液；成膜添加剂；导电聚合物；理论计算

英文摘要： The enhancement of energy density, safety and endurance is an important key on the development of power lithium ion battery. It’s an effective way to improve the energy density of lithium ion battery utilizing the high voltage cathode materials. However, electrolyte solvents and organic carbonate esters sustain decomposition on highly oxidative surfaces of these charged cathodes. The aim of this project is to solve this problem by using new type electrolyte additives to avoid the interface reaction between them. The design of the new type electrolyte additives and formation mechanism are studied by theoretical calculation and experimental methods. Density functional theory and linear sweep voltammetry are utilized to calculate and test the oxidation potential of the additives. Organic electro-oxidation technique is adopted to prepare interfacial film and analyze its component, formation mechanism, thermostability and chemical stability. The feature of this project is the design of new double-layer interfacial film formation additives. The electrodes with the double-layer interface films formed through different methods are studied to find out an effective method to prepare low cost high stability film. The rate capability, cycle stability and safety of battery with new type film additives were characterized using electrochemistry methods. Finally, the improvement on the battery performance of the power lithium ion battery can be achieved through the application of the new type additives.

英文关键词： Lithium ion batteries ;electrolyte;film-forming additives;conducting polymer;theoretical calculation