无机材料学报

• 研究论文 • 上一篇    下一篇

镁离子掺杂对 LiFePO4/C电化学性能和结构的影响

杨书廷1,2, 刘玉霞1,2, 尹艳红1,2, 王辉1,2, 崔成伟2,3   

  1. 1. 河南师范大学化学与环境科学学院, 新乡 453007; 2. 河南省新能源材料工程研究中心, 新乡 453007; 3. 新乡市中科科技有限公司, 新乡 453002
  • 收稿日期:2006-08-18 修回日期:2006-10-23 出版日期:2007-07-20 网络出版日期:2007-07-20

Effects of Mg Ion Doping on the Electrochemical Performances and
Structure of LiFePO4 /C

YANG Shu-Ting 1,2, LIU Yu-Xia1,2, YIN Yan-Hong1,2, WANG Hui1,2, CUI Cheng-Wei 2,3   

  1. 1. College of Chemistry and Environmental Science, Henna Normal University, Xinxiang 453007, China; 2. Research Institute of New Energy & Material Engineering of Henan Province, Xinxiang 453007, China; 3. Zhongke Science & Technology CO. Ltd, Xinxiang 453002, China
  • Received:2006-08-18 Revised:2006-10-23 Published:2007-07-20 Online:2007-07-20

摘要: 以乳酸镁做为Mg2+的掺杂源和部分的碳源, 在惰性氛围下用模板-固相合成法合成了掺Mg2+的LiFePO4/C复合正极材料, 考察了Mg2+对于目标化合物电化学和物理性能的影响. 研究结果表明, 在C/3倍率下材料掺杂前后第二个循环的放电容量分别为140.5和159.9mAh/g, 循环20次后容量为140.4 和162.1mAh/g. 电化学交流阻抗表明, 掺杂后的材料阻抗Rct从180Ω 减小到120Ω. 掺杂后振实密度比掺杂前提高了0.229g·cm-3.

关键词: 乳酸镁, LiFePO4/C, 正极材料, 掺杂

Abstract:

Stoichiometric Mg doped LiFePO4/C cathode material was synthesized through a templatesolid state reaction in an inert atmosphere using magnesium lactate as dopant and part of carbon source. Effects of Mg2+ doping on the electrochemical and physical performances of the cathode materials were investigated. At 1/3C discharge rate, the secondly reversible specific capacity of the Mg-doped LiFePO4/C is nearly 20mAh/g higher than that of the undoped one. After 20 cycles, the capacity of the former is 162.1mAh/g, 22mAh/g higher than that of the latter. Impedance R ct of the Mg-doped material is 120Ω, while that of the undoped material is 180Ω. The tap density of Mg-doped material is
also improved by 0.229g·cm-3 compared with undoped material.

Key words: magnesium lactate, LiFePO4/C, cathode material, doping

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