无机材料学报

• 研究论文 • 上一篇    下一篇

锂离子电池正极材料LiMnyFe1-yPO4的制备及性能研究

谢辉, 周震涛   

  1. 华南理工大学材料科学与工程学院, 广州 510640
  • 收稿日期:2005-06-23 修回日期:2005-09-14 出版日期:2006-05-20 网络出版日期:2006-05-20

Synthesis and Performances of LiMnyFe1-yPO4 as Cathode Materials for Lithium-ion Batteries

XIE Hui, ZHOU Zhen-Tao   

  1. College of Material Science & Engineering, South-China University of Technology, Guangdong 510640, China
  • Received:2005-06-23 Revised:2005-09-14 Published:2006-05-20 Online:2006-05-20

摘要: 采用高速球磨与高温固相反应相结合的方法合成了LiMnyFe1-yPO4(0.1≤ y≤1.0)锂离子电池正极材料, 并对其晶体结构、表观形貌和电化学性能进行了研究. 结果表明, 所合成的LiMnyFe1-yPO4为单一橄榄石型结构, 粒径分布较均匀. 当以小电流密度(0.1C)充放电时, LiMn0.1Fe0.9PO4具有最高的放电比容量, 为145mAh/g; LiMn0.6Fe0.4PO4质量比能量最高, 达568Wh/kg. LiMnyFe1-yPO4的倍率放电性能随着y的增加而降低, 这主要是材料在4.0V平台的容量损失造成的; LiMn0.1Fe0.9PO4具有最佳的倍率性能: 以0.5、1.5C倍率进行放电, 放电容量分别达到130、109mAh/g.

关键词: 锂离子电池, 磷酸铁/锰锂, 循环伏安, 倍率性能

Abstract: The LiMnyFe1-yPO4 (0.1≤ y≤1) cathode materials for lithium-ion batteries were synthesized by solid-state reaction combined with high-rate ball milling. The crystalline structure, morphology of particles, and electrochemical performance of the sample were investigated by X-ray diffraction, scanning electron microscope, charge-discharge test and cyclic voltammetry. The results show that all LiMnyFe1-yPO4 samples are simple pure olive-type phase with small particles, and uniformly distribution of gain sizes. At low rate of 0.1C, the first specific discharge capacity of LiMn0.1Fe0.9PO4 is the highest with 145mAh/g and LiMn0.6Fe0.4PO4 shows the highest energy density of 568Wh/kg. The rate capabilities of the samples are strongly influenced by y value of LiMnyFe1-yPO4. LiMn0.1Fe0.9PO4 shows the best rate capabilities with discharge capacity of 130mAh/g at 0.5C rate and 109mAh/g at 1.5C rate.

Key words: lithium-ion batteries, lithium iron/manganese phosphate, cyclic voltammetry, rate capability

中图分类号: