物理化学学报 >> 2009, Vol. 25 >> Issue (05): 1004-1008.doi: 10.3866/PKU.WHXB20090418

研究论文 上一篇    下一篇

微波合成法制备锂离子电池正极材料Li2FeSiO4

胡国荣 曹雁冰 彭忠东 杜柯 蒋庆来   

  1. 中南大学冶金科学与工程学院, 长沙410083
  • 收稿日期:2008-12-01 修回日期:2008-12-26 发布日期:2009-05-04
  • 通讯作者: 胡国荣

Preparation of Li2FeSiO4 Cathode Material for Lithium-Ion Batteries by Microwave Synthesis

HU Guo-Rong, CAO Yan-Bing, PENG Zhong-Dong, DU Ke, JIANG Qing-Lai   

  1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, P. R. China
  • Received:2008-12-01 Revised:2008-12-26 Published:2009-05-04
  • Contact: HU Guo-Rong

摘要:

研究了一种制备锂离子电池正极材料Li2FeSiO4的新方法. 采用机械球磨结合微波热处理合成了Li2FeSiO4正极材料. 通过XRD、SEM和恒流充放电测试, 对样品结构、形貌和电化学性能进行了表征和分析. 与传统固相法合成的材料在晶体结构、微观形貌以及充放电性能方面进行了比较. 结果表明, 微波合成法可以快速制备具有正交结构的Li2FeSiO4材料; 在650 ℃时处理12 min, 获得了纯度高、晶粒细小均匀的产物, 该产物具有较高的放电比容量和良好的循环性能. 在60 ℃下以C/20倍率(电流密度, 1C=160 mA·g-1)进行充放电, 首次放电容量为119.5 mAh·g-1, 10次循环后放电容量为116.2 mAh·g-1. 与传统高温固相法相比, 微波合成法制备的材料具有较高的纯度、均匀的形貌和较好的电化学性能.

关键词: 锂离子电池, 正极材料, Li2FeSiO4, 微波合成

Abstract:

We report a novel synthetic route for the preparation of the Li2FeSiO4 cathode material by microwave processing. The Li2FeSiO4 material was synthesized using mechanical ball-milling and subsequent microwave processing. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, and electrochemical methods. Properties of the prepared materials and electrochemical characteristics of the samples were investigated and compared to samples prepared by the conventional solid-state reaction. The obtained results indicated that highly pure Li2FeSiO4 material with uniform and fine particle size was quickly and successfully synthesized by microwave (MW) heating at 650 ℃ for 12 min. This compound showed high specific capacity and good cycle ability. The initial discharge capacity of the sample obtained by MW heating delivered 119.5 mAh·g-1 at 60 ℃ at a current density of C/20 rate (1C=160 mA·g-1). After 10 cycles the discharge capacity maintained 116.2 mAh·g-1. The Li2FeSiO4 material displayed higher phase purity, better microstructure, and better electrochemical properties than the sample prepared by the conventional solid-state method.

Key words: Li-ion battery, Cathode material, Li2FeSiO4, Microwave synthesis

MSC2000: 

  • O646