东北大学学报（自然科学版）

东北大学学报(自然科学版) ›› 2010, Vol. 31 ›› Issue (6): 860-863.DOI: -

• 论著 • 上一篇    下一篇

碳包埋固相法制备LiFePO_4及其电化学性能研究

康晓雪;田彦文;曲涛;   

  1. 东北大学材料与冶金学院;辽宁科技学院冶金系;
  • 收稿日期:2013-06-20 修回日期:2013-06-20 出版日期:2010-06-15 发布日期:2013-06-20
  • 通讯作者: -
  • 作者简介:-
  • 基金资助:
    辽宁省科技攻关项目(2005224016)

Synthesis of LiFePO4 by solid-state method with raw materials embedded in graphite and electrochemical properties

Kang, Xiao-Xue (1); Tian, Yan-Wen (1); Qu, Tao (2)   

  1. (1) School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China; (2) Department of Metallurgy Engineering, Liaoning Institute of Science and Technology, Benxi 117000, China
  • Received:2013-06-20 Revised:2013-06-20 Online:2010-06-15 Published:2013-06-20
  • Contact: Tian, Y.-W.
  • About author:-
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摘要： 用石墨粉包埋取代保护性气氛,一步固相法制备LiFePO4.采用XRD,FTIR,SEM和恒电流充放电等方法对材料结构、形貌和电化学性能进行了表征.利用循环伏安法研究了Li+在LiFePO4中的嵌/脱过程.结果表明,这种改进的固相法可以合成亚微米级纯相橄榄石结构LiFePO4,所得材料具有良好的倍率性能和循环稳定性,在0.1C和1C倍率首次放电比容量分别为148.3和131.9mAh.g-1,1C和5C倍率下循环50次容量保持率分别为96%和90%.由循环伏安法计算得到阳极峰和阴极峰处Li+的表观扩散系数分别为1.64×10-13和1.94×10-13cm2.s-1.

关键词: LiFePO4, 石墨包埋, 一步固相法, 扩散系数, 循环伏安

Abstract: LiFePO4 was successfully synthesized as a product via one-step solid-state reaction during which the raw materials were embedded in graphite powder instead of the protective atmosphere when heated at high-temperature. The structure, morphology and electrochemical properties of the product were investigated by XRD, FTIR, SEM and galvanostatic charge/discharge test. The process of lithiation/delithiation of Li+ in LiFePO4 electrode was studied by cyclic voltammetry. The results showed that the pure-phase olivine-type LiFePO4 composed of near spherical particles in sub-micrometered size can be obtained by this improved solid-state method. The LiFePO4 thus prepared has favorable multiplication rate and cycling stability. The initial discharge specific capacity is 148.3 and 131.9mAh·g-1 if the rate is 0.1 C and 1 C, respectively; and after the charge/discharge action cycles 50 times the capacity holding rate is 96% and 90% if the rate is 1 C and 5 C, respectively. As calculated according to cyclic voltammetry, the apparent Li+ diffusion coefficients are 1.64×10-13 and 1.94×10-13 cm2·s-1 at the peaks of corresponding CV curves of anode and cathode, respectively.

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