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化学学报
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化学学报 ›› 2009, Vol. 67 ›› Issue (14): 1547-1552. 上一篇    下一篇

研究论文

电化学阻抗谱法研究Cu6Sn5合金负极相变过程

樊小勇*,a,b 庄全超b 魏国祯b 柯福生b 黄 令b
董全峰b 孙世刚*,b

  

  1. (a长安大学材料科学与工程学院 西安 710061)
    (b厦门大学化学化工学院化学系 固体表面物理化学国家重点实验室 厦门 361005)

  • 投稿日期:2008-10-30 修回日期:2008-12-26 发布日期:2009-07-28
  • 通讯作者: 樊小勇

Electrochemical Impedance Spectroscopy Study on Phase Transformation of Cu6Sn5 Alloy Anode

Fan, Xiaoyong *,a,b Zhuang, Quanchao b Wei, Guozhen b Ke, Fusheng b Huang, Ling b
Dong, Quanfeng b Sun, Shigang *,b

  

  1. (a School of Materials Science and Engineering, Chang’an University, Xi’an 710061)
    (b State Key Laboratory for Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and
    Chemical Engineering, Xiamen University, Xiamen 361005)
  • Received:2008-10-30 Revised:2008-12-26 Published:2009-07-28
  • Contact: Fan, Xiaoyong

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以粗糙铜箔为基底, 采用一步电沉积法获得Cu-Sn合金, X射线衍射(XRD)测试结果显示其主要为Cu6Sn5合金相. 扫描电子显微镜(SEM)测试结果表明该合金表面由大量“小岛”组成, 且每个“小岛”上存在大量纳米合金粒子. 充放电测试结果表明, 以该合金为锂离子电池负极, 其初始放电(嵌锂)和充电(脱锂)容量分别为461和405 mAh•g－1. 电化学阻抗谱测试结果显示, Cu6Sn5合金电极在阴极极化过程中分别出现了代表固体电解质界面膜(SEI膜)阻抗、电荷传递阻抗和相变阻抗的圆弧, 并详细分析了它们的变化规律.

关键词: 锂离子电池, 负极, Cu6Sn5合金, 电化学阻抗谱, 相变

The Cu-Sn alloy electrode was prepared by a one-step electrodepositing method using rough Cu foil as the substrate, and was determined as the intermetallic composite of Cu6Sn5 using an X-ray diffraction (XRD) method. The electrode surface morphology was analyzed by scanning electron microscopy (SEM) which displayed “small islands” structure with many nano-particles on it. The first discharge and charge capacities were determined as 461 and 405 mAh•g－1, respectively. Electrochemical impedance spectra (EIS) indicated that there appeared three arcs in the Nyquist plots respectively representing the impedance of solid electrolyte interphase film, charge transfer and phase transformation in the first lithiation, and their evolutive principles were also investigated.

Key words: lithium ion battery, anode, Cu6Sn5 alloy, electrochemical impedance spectroscopy, phase transformation