物理化学学报 >> 2005, Vol. 21 >> Issue (07): 725-729.doi: 10.3866/PKU.WHXB20050706

研究论文 上一篇    下一篇

Ti、Mg离子复合掺杂对LiNi0.4Co0.2Mn0.4O2性能的影响

黄友元; 周恒辉; 陈继涛; 高德淑; 苏光耀   

  1. 湘潭大学化学学院, 湘潭 411105； 北京大学化学与分子工程学院, 北京 100871
  • 收稿日期:2004-11-17 修回日期:2005-01-04 发布日期:2005-07-15
  • 通讯作者: 高德淑 E-mail:sugy@xtu.edu.cn

The Effect of Ti4+, Mg2+ Co-doping on Performance of LiNi0.4Co0.2Mn0.4O2

HUANG You-yuan; ZHOU Heng-hui; CHEN Ji-tao; GAO De-shu; SU Guang-yao   

  1. College of Chemistry, Xiangtan University, Xiangtan 411105； College of Chemistry and Molecular Engineering, Peking University, Beijing 100871
  • Received:2004-11-17 Revised:2005-01-04 Published:2005-07-15
  • Contact: GAO De-shu E-mail:sugy@xtu.edu.cn

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摘要： 采用SEM、XRD、恒电流充放电、交流阻抗谱等方法研究了钛镁离子复合掺杂对LiNi0.4Co0.2Mn0.4O2的结构及其电化学性能的影响. 结果表明材料的XRD图谱中部分特征峰的强度比值有较大的变化. 1%(摩尔分数) 的Ti、Mg离子复合掺杂能显著地改善LiNi0.4Co0.2Mn0.4O2的倍率放电能力, 平台保持能力和高倍率下的循环性能. 交流阻抗谱表明钛镁离子掺杂抑制了LiNi0.4Co0.2Mn0.4O2在高放电倍率下循环的电化学反应阻抗Rct的增加. 采用几种不同价态的金属离子复合掺杂是改善嵌锂的镍钴锰系金属氧化物的倍率放电能力的有效途径.

关键词: LiNi0.4Co0.2Mn0.4O2, 层状结构, 钛镁复合掺杂, 倍率特性, 锂离子电池

Abstract: The effect of co-doping with Ti and Mg ions in LiNi0.4Co0.2Mn0.4O2 on structure and electrochemical performance was investigated by using SEM, XRD, EIS and galvanostatic charge-discharge experiment. The XRD showed that some characteristic peak intensity ratios have significant change. The rate discharge capability and cycle stability of LiNi0.4Co0.2Mn0.4O2 can be improved significantly by a small amount of Ti, Mg ions co-doping (1% molar ratio). AC impedance was used to study the processes of charge-discharge cycle. The result showed that (Ti4+, Mg2+) multiple-ion dopant can evidently suppress the increasing of the electrochemical reaction resistant Rct at 1C & 2C discharge rates. Co-doping of metal ions with diferent valences is a useful method to improve large current discharge capability of the lithium insertion nickel cobalt manganese oxides.

Key words: LiNi0.4Co0.2Mn0.4O2, Layeredstructure, (Ti4+, Mg2+) multiple-ion dopant, Rate-capability, Lithium ion battery