电化学阻抗谱法研究Cu_6Sn_5合金负极相变过程  

Electrochemical Impedance Spectroscopy Study on Phase Transformation of Cu_6Sn_5 Alloy Anode

作　　者：樊小勇[1,2] 庄全超[2] 魏国祯[2] 柯福生[2] 黄令[2] 董全峰[2] 孙世刚[2] 

机构地区：[1]长安大学材料科学与工程学院,西安710061 [2]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

出　　处：《化学学报》2009年第14期1547-1552,共6页Acta Chimica Sinica

基　　金：国家重点基础研究和发展规划(973)(No.2009CB220102);国家自然科学基金(No.20773102)资助项目

摘　　要：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405mAh·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.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.

关 键 词：锂离子电池 负极 Cu6Sn5合金 电化学阻抗谱 相变 

分 类 号：TM912[电气工程—电力电子与电力传动]