空位缺陷结合掺杂金属离子对LiNi0.5Mn1.5O4正极材料高功率电化学性能的影响及机理研究

项目名称： 空位缺陷结合掺杂金属离子对LiNi0.5Mn1.5O4正极材料高功率电化学性能的影响及机理研究

项目编号： No.51462029

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 王海龙

作者单位： 宁夏大学

项目金额： 47万元

中文摘要： 电动汽车和能源材料是国家和宁夏重点支持的高技术产业。锂离子动力电池是电动汽车中的关键技术，正极材料的电位、容量和快速充放电性能很大程度上决定了锂离子电池的功率性能。 LiNi0.5Mn1.5O4具有很高的电位和可观的容量，在锂离子动力电池领域有很好的应用前景，但在快速充放电条件下，其性能急剧恶化，晶体结构特性和较差的导电性是其性能恶化的重要原因；掺杂金属离子一般以1:1比例取代Ni、Mn离子，并保持其完整的AB2O4化学通式, 通常对晶体结构特性或导电性某一方面有显著改善。本项目提出将空位缺陷与掺杂金属离子结合的方法，利用空位缺陷对于晶体结构和导电性的影响，结合不同金属离子的独特掺杂效果，同时改善LiNi0.5Mn1.5O4的晶体结构特性和导电性；系统研究该方法对于晶体结构特性、导电性和电化学性能带来的新的影响规律及其机理，为LiNi0.5Mn1.5O4性能的进一步改善提供理论和实验基础。

中文关键词： 锂离子电池；正极材料；电化学性能；晶体结构；电导率

英文摘要： Both electric vehicles and energy materials are high-tech industries supported by central-government and Ningxia local-government. Lithium ion power battery is a key technology for electrical vehicles, and the potential, capacity and high-rate charge/discharge performances of the cathodes could dominate the power performances of the lithium ion batteries in a large extent. LiNi0.5Mn1.5O4 is a very proming cathode to be used in lithium ion power batteries owing to its high potential and large capacity, but at high-rate charge/discharge conditions,its performances deteriorate badly;its crystal structure charateristics and poor electrical conductivity are key factors leading to the poor performances at high current rates. Metal-ion doping method generally uses positively charged metal-ion to replace Ni or Mn ion in a ratio of 1:1, and maintain the perfect chemical formula AB2O4; it usually could put significant influence on either crystal structure characteristics or electrical conductivity. In this project, we propose a method of combining the vacancy defects and metal-ion dopants together to improve the crystal structure charateristics and electrical conductivity at the same, through utilizing the significant influences of vancay defects and specific effects of different dopant ions; the effects and mechanisms of this method on the cyrstal structure characteristics,electrical conductivity and electrochemical performances will be systematically investigated, and it could build the theoretical and experimental basis for further improving the high power electrochemical performances of LiNi0.5Mn1.5O4 cathode.

英文关键词： Lithium Ion Batteries;Cathode;Electrochemical Performance;Crystal Structure;Electrical Conductivity