化学学报 ›› 2012, Vol. 70 ›› Issue (9): 1055-1058.DOI: 10.6023/A1112222 上一篇    下一篇

研究论文

XANES 研究Al2O3 包覆LiNi0.4Co0.2Mn0.4O2 材料的稳定性

刘浩涵, 张建, 娄豫皖, 夏保佳   

  1. 中国科学院上海微系统与信息技术研究所 上海 200050
  • 投稿日期:2011-12-22 修回日期:2012-03-15 发布日期:2012-03-20
  • 通讯作者: 夏保佳 E-mail:xiabj@mail.sim.ac.cn
  • 基金资助:

    上海市科委纳米专项(No. 1052nm00100)和上海市科委重大项目子课题(No. 11DZ1100205)资助项目.

An XANES Study of the Stability of Al2O3 Coated LiNi0.4Co0.2Mn0.4O2

Liu Haohan, Zhang Jian, Lou Yuwan, Xia Baojia   

  1. Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050
  • Received:2011-12-22 Revised:2012-03-15 Published:2012-03-20
  • Supported by:

    Project supported by the Shanghai Committee of Science and Technology, China (No. 1052nm00100) and (No. 11DZ1100205).

采用溶胶凝胶水解法在LiNi0.4Co0.2Mn0.4O2 (NCM)表面包覆了0.5 wt% Al2O3. 透射电镜(TEM)表明在NCM 表面形成了均匀的Al2O3 包覆层; 分别采用恒电位极化及热重分析(TG)研究了包覆前后NCM的析氧特性; 采用X射线吸收近边结构谱(XANES)研究了包覆前后O 的电子结构. 结果表明, 包覆后的NCM析氧量更少; Al2O3 包覆使得NCM 表面层中与金属3d 轨道杂化的O 比例减少, 而更稳定的、与金属4sp 轨道杂化的O 比例增加. 这些因素导致Al2O3 包覆后的NCM 更加稳定、安全性更高.

关键词: 锂离子电池, LiNi0.4Co0.2Mn0.4O2, Al2O3 包覆, X 射线吸收近边结构谱

0.5 wt% Al2O3-coated LiNi0.4Co0.2Mn0.4O2 (NCM) for lithium-ion batteries was prepared by sol-gel hydrolysis method. The TEM (transmission electron microscopy) showed that Al2O3 was covered uniformly at the surface of the NCM (LiNi0.4Co0.2Mn0.4O2). The linear potential sweep and thermogravimetric tests were performed to investigate the oxygen evolution of the NCM. The electronic structure of O was investigated by the XANES (X-ray absorption near edge structure). The results indicated that the oxygen evolution of the NCM was suppressed by the Al2O3 coating, and partial hybrid state of metal 3d and O2p was translated to a hybrid of metal 4sp and O2p by the Al2O3 coating, leading to the improvement of the safety performance.

Key words: lithium ion battery, LiNi0.4Co0.2Mn0.4O2, Al2O3 coating, XANES