浸入式表面修饰富锂层状正极材料的制备与电化学性能

项目名称： 浸入式表面修饰富锂层状正极材料的制备与电化学性能

项目编号： No.21473075

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 分析化学

项目作者： 魏英进

作者单位： 吉林大学

项目金额： 80万元

中文摘要： 富锂层状材料是具有重要应用前景的高比容量锂离子电池正极材料，其高比容量特性源于首次充电过程中特殊的氧气释放机制。然而，由于氧气释放导致材料的表面结构发生变化，并且与电解液发生复杂的表面/界面反应，严重影响了材料的电化学性能。本项目拟采用浸入式表面修饰解决上述问题，通过修饰层与主体材料之间的结构耦合，实现在原子尺度上对材料表面结构的调控，使其更有利于锂离子的可逆插入与脱出，同时有效抑制材料与电解液之间的表面/界面反应，提高材料的电化学性能。研究主要包括以下几个方面：（1）浸入式表面修饰富锂层状正极材料的制备；（2）浸入式表面修饰富锂层状材料的成份与结构表征；（3）表面修饰对富锂层状材料电化学反应机理的影响；（4）浸入式表面修饰富锂层状材料的电化学性能等。通过研究，获得具有高放电容量、并且倍率性能和循环性能优良的富锂层状正极材料，为实现应用奠定基础。

中文关键词： 锂离子电池；正极材料；表面修饰；电化学性能

英文摘要： Li-excess layered oxides are promising cathode materials for Li-ion batteries due to their high capacities over 250 mAh g-1 resulting from the unique oxygen loss process during the first charge. However, the irreversible surface structural transition, and the tedious side reactions between the active material and the electrolyte seriously hinder the electrochemical properties of the materials. In this project, we propose to use Inpregnated Surface Modification to resolve the above problems. With this novel technique, the surface structure of Li-excess layered oxides can be modified by the surface modification layer at the atomic level, which enables more effective Li+ intercalation and depresses the harmful side reactions. The research majorly involves: (1) preparation of the inpregnated surface modified Li-excess layered oxides; (2) chemical and structural characterizations of the materials; (3) effects of impregnated surface modification on the electrochemical properties of Li-excess layered oxides; (4) electrochemical performance of the inpregnated surface modified Li-excess layered oxides. Based on this work, the electrochemical properties of Li-excess layered oxides such as discharge capacity, rate capability, and capacity retention can be effectively improved by the impregnated surface modification, which will promote the practical applications of Li-excess layered oxides in Li-ion batteries.

英文关键词： Li-ion battery;Cathode Material;Surface Modification;Electrochemical Properties