物理化学学报 >> 2009, Vol. 25 >> Issue (06): 1232-1238.doi: 10.3866/PKU.WHXB20090629

研究论文 上一篇    下一篇

锂离子电池正极材料LiMnO2的掺杂及其电化学性能

粟智, 徐茂文, 叶世海, 王永龙   

  1. 新疆师范大学生命科学与化学学院, 乌鲁木齐 830054|南开大学化学学院, 新能源材料化学研究所, 天津 300071
  • 收稿日期:2008-12-26 修回日期:2009-03-09 发布日期:2009-06-05
  • 通讯作者: 粟智 E-mail:suzhixj@sina.com

Doping of Layered LiMnO2 as Cathode Materials for Lithium-Ion Batteries and Their Electrochemical Properties

SU Zhi, XU Mao-Wen, YE Shi-Hai, WANG Yong-Long   

  1. College of Life Science and Chemistry, Xinjiang Normal University, Urumqi 830054, P. R. China|Institute of New Energy Material Chemistry, College of Chemistry, Nankai University, Tianjin 300071, P. R. China
  • Received:2008-12-26 Revised:2009-03-09 Published:2009-06-05
  • Contact: SU Zhi E-mail:suzhixj@sina.com

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摘要：

采用水热法合成了用于锂离子电池正极材料的LiMxMn1-xO2(M=Mg, Y, Zr)化合物. 采用X射线衍射(XRD)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)等手段对材料的晶体结构和形貌进行了表征, 材料的电化学性能通过恒流充放电和交流阻抗谱(EIS)进行测试, 分析了掺杂元素在改善材料性能中的作用. 结果表明, 掺杂后的LiMxMn1-xO2正极材料循环性能优于未经掺杂的材料. 其中以掺杂钇的i0.99Mn0.979Y0.021O2正极材料循环性能最佳, 在室温下, 充放电电流密度为50 mA·g-1时, 60次循环后放电容量为226.3 mAh·g-1.

关键词: 层状LiMnO2, 掺杂, 水热合成法, 电化学性能

Abstract:

Hydrothermal methods were used to prepare doped LiMxMn1-xO2(M=Mg, Y, Zr) as cathode materials for lithium-ion batteries. The structure and morphology of the as-prepared cathode materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The effects of ion doping on the performance of orthorhombic materials was analyzed in terms of their crystal structure, charge-discharge curves, cycle performance and electrochemical impedance spectroscopy (EIS). Results show that the doped materials had better cycle performance. In particular, the discharge capacity of Li0.99Mn0.979Y0.021O2 remains 226.3 mAh·g-1 after 60 cycles with a current density of 50 mA·g-1 at roomtemperature.

Key words: Layered LiMnO2, Doping, Hydrothermal synthesis, Electrochemical property