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电化学(中英文) ›› 2013, Vol. 19 ›› Issue (6): 558-564.  doi: 10.13208/j.electrochem.130354

• 锂离子电池近期研究专辑 (厦门大学 杨勇教授主编) • 上一篇    下一篇

铝掺杂LiFePO4的表面成份结构及电化学性能研究

尚怀芳1,黄伟峰2,储旺盛2,夏定国3*,吴自玉2*   

  1. 1. 北京工业大学环境与能源工程学院环境电化学实验室,北京 100717;2. 中国科技大学国家同步辐射实验室,合肥 230026;3. 北京大学工学院先进电池材料理论与技术北京市重点实验室,北京 100871
  • 收稿日期:2013-05-06 修回日期:2013-05-24 出版日期:2013-12-28 发布日期:2013-12-23
  • 通讯作者: 夏定国 E-mail:dgxia@pku.edu.cn
  • 基金资助:

    国家自然科学基金项目(No. 11179001)、北京市自然科学基金项目(No. 20110001)和国家高技术研究发展863计划项目(No. 2011AA11A254,No. 2012AA052201)资助

Surface Composition Structure and Electrochemical Performance of Aluminum Doped LiFePO4

SHANG Huai-fang1, HUANG Wei-feng2, HU Wang-sheng2, XIA Ding-guo3*, WU Zi-yu2*   

  1. 1. College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022, P. R. China; 2. NSRL, University of Science and Technology of China, Hefei 230026, P. R. China; 3. Key lab of theory and technology for advanced batteries materials, College of Engineering, Peking University, Beijing 100871, P. R. China
  • Received:2013-05-06 Revised:2013-05-24 Published:2013-12-28 Online:2013-12-23
  • Contact: XIA Ding-guo E-mail:dgxia@pku.edu.cn

摘要: 锂离子电池正极材料掺杂LiFePO4的报道已很多,而涉及掺杂LiFePO4的表面成份及结构的研究仍很少见. 本文采用溶剂热法一步得了表面富Al的LiFePO4正极材料. TEM测试证实LiFePO4的表面形成均匀的无定型包覆层;俄歇电子能谱和软X射线吸收谱共同揭示了其表面的自包覆层为部分Al替代Fe的LiFe1-xAlxPO4. 表面富Al(x=0.02)的LiFePO4显示了较好的电化学倍率性能和低温性能,充放电-10 oC的条件下,电压范围2.2 ~ 4.2 V、0.1C倍率电极的放电比容量为98 mAh·g-1,0.5C倍率放电比容量可达70 mAh·g-1. 这归因于Al的加入改变了材料体相及表面的电子结构,增加了体相电子的传导及表面离子的传导.

关键词: LiFePO4, 表面包覆, 电化学性能

Abstract: Despite there are many successful reports about the preparation of electrode materials with surface coating for lithium ion batteries, the study in surface self-coating of cathode materials using segregation of doping elements and their electrochemical properties is still very rare. The LiFePO4 particles with rich-Al on the surface were synthesized by one step solvothermal route. TEM results demonstrated that the surface of the obtained LiFePO4 particles was well-covered by the amorphous coating. The soft X-ray absorption spectroscopy (XAS) and Auger electron spectroscopy (AES) component analyses revealed that the amorphous coating was composed of LiFe1-xAlxPO4 by part of Al substitution to Fe. The LiFePO4 material with surface rich-Al showed good electrochemical rate capacity and low temperature performance. This could be attributed to the changes of the bulk and surface electron structures which promote the bulk electron and surface ionic conductivities.

Key words: LiFePO4, surface coating, electrochemical performances

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