高等学校化学学报 ›› 2011, Vol. 32 ›› Issue (4): 946.

• 研究论文 • 上一篇    下一篇

5 V锂离子电池正极材料LiNi0.5Mn1.5O4的合成与Li+在材料中的扩散性能

卢华权,吴锋,苏岳锋,李宁,陈实,包丽颖   

  1. 北京理工大学化工与环境学院,   国家高技术绿色材料发展中心, 北京 100081
  • 收稿日期:2010-06-21 修回日期:2010-10-19 出版日期:2011-04-10 发布日期:2011-03-09
  • 通讯作者: 苏岳锋 E-mail:suyuefeng@bit.edu.cn
  • 基金资助:

    国家“九七三”计划项目(批准号: 2009CB220100)资助.

Preparation of LiNi0.5Mn1.5O4 as 5 V Cathode Materials for Lithium Ion Battery and Diffusion  Performance of Li+ in the Materials

LU Hua-Quan, WU Feng, SU Yue-Feng*, LI Ning, CHEN Shi, BAO Li-Ying   

  1. School of Chemical Engineering & Environment, Beijing Institute of Technology, National Development Center of Hi-Tech Green Materials, Beijing 100081,   China
  • Received:2010-06-21 Revised:2010-10-19 Online:2011-04-10 Published:2011-03-09
  • Contact: SU Yue-Feng E-mail:suyuefeng@bit.edu.cn
  • Supported by:

    国家“九七三”计划项目(批准号: 2009CB220100)资助.

摘要: 使用草酸盐共沉淀法合成了5 V正极材料LiNi0.5Mn1.5O4,研究了不同温度下合成的材料结构形貌与电化学性能之间的关系。结果表明,在900℃下合成的样品电化学性能最好,可逆放电容量达到133.0 mAh?g-1,经30周循环后,容量仍然保持在132.2 mAh?g-1,容量保持率高达99.4%。使用恒电位间歇滴定法(PITT)测定了锂离子在LiNi0.5Mn1.5O4材料中的扩散系数。结果表明,在LiNi0.5Mn1.5O4材料放电过程中,在不同电位嵌锂量不同,发生反应的氧化还原电对也不同,锂离子的扩散系数在不同的电位下也会有差别,扩散系数在10e-10 cm2?s-1~10e-11 cm2?s-1范围内变

关键词: 锂离子电池, 正极材料, 草酸盐共沉淀;LiNi0.5Mn1.5O4;扩散系数

Abstract: 5 V cathode material LiNi0.5M1.5O4 was synthesized via an oxalate co-precipitation method, and the relationship between the structure, morphology and the electrochemical performance of the material were investigated. The results show that the sample synthesized at 900 ℃ has the best electrochemical performance, and its reversible capacity reaches 133.0 mAh?g-1. After 30 cycles, this LiNi0.5Mn1.5O4 sample maintains a discharge capacity of 132.2 mAh?g-1 with a capacity retention rate of 99.4%. The chemical diffusion coefficient of Li-ion in LiNi0.5M1.5O4 cathode material was measured by potentiostatic intermittent titration technique (PITT). It’s found that at the different voltage point of the discharge process, the change of Li content and the redox couple is also different, thus the chemical diffusion coefficient of Li-ion is various, it ranges in 10e-10 cm2?s-1~10e-11 cm2?s-1.

Key words: Lithium-ion batteries, Cathode material, Oxalate co-precipitation; LiNi0.5Mn1.5O4; Diffusion coefficient

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