物理化学学报 >> 2011, Vol. 27 >> Issue (10): 2353-2359.doi: 10.3866/PKU.WHXB20111004

电化学和新能源 上一篇    下一篇

嵌入化合物电极的电化学阻抗谱: 模型与理论模拟

徐守冬1,2, 庄全超1, 史月丽1, 朱亚波1,2, 邱祥云1,2, 孙智1   

  1. 1. 中国矿业大学材料科学与工程学院锂离子电池实验室, 江苏徐州 221116;
    2. 中国矿业大学化学工程学院, 江苏徐州 221116
  • 收稿日期:2011-05-04 修回日期:2011-07-12 发布日期:2011-09-27
  • 通讯作者: 庄全超 E-mail:zhuangquanchao@126.com
  • 基金资助:

    中央高校基本科研业务费专项资金(2010LKHX03, 2010QNB04, 2010QNB05), 中国矿业大学科技攀登计划(ON090237)及江苏省自然科学研究基金(BK2008129)资助项目

Electrochemical Impedance Spectra of Intercalation Compound Electrodes: Models and Theoretical Simulations

XU Shou-Dong1,2, ZHUANG Quan-Chao1, SHI Yue-Li1, ZHU Ya-Bo1,2, QIU Xiang-Yun1,2, SUN Zhi1   

  1. 1. Li-ion Batteries Laboratory, School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou 221116, Jiangsu Province, P. R. China;
    2. School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu Province, P. R. China
  • Received:2011-05-04 Revised:2011-07-12 Published:2011-09-27
  • Contact: ZHUANG Quan-Chao E-mail:zhuangquanchao@126.com
  • Supported by:

    The project was supported by the Fundamental Research Funds for the Central Universities, China (2010LKHX03, 2010QNB04, 2010QNB05), Science and Technology"Climbing"Program of CUMT, China (ON090237) and Natural Science Foundation of Jiangsu Province, China (BK2008129).

摘要: 建立了单个嵌入化合物颗粒、混合颗粒、厚度均匀多孔电极层以及非均匀、多层多孔电极层的理论模型, 模拟得出了上述模型的相对应电化学阻抗谱(EIS)特征. 结果表明, 单个颗粒和混合颗粒表现出相似的阻抗谱特征, 均由高频区域内与锂离子通过固体电解质相界面(SEI)膜过程相关的RSEICSEI半圆, 与电荷传递过程相关的RctCdl半圆以及与锂离子在固体颗粒内部的扩散相关的斜线三部分组成. 对于非均匀、多层多孔嵌入电极而言, 一个新奇的现象就是在阻抗谱中会出现三个半圆, 影响第三个半圆出现并形成的因素主要为电极中的颗粒尺寸分布以及电极层的厚度分布, 也就是说电极片中出现不同尺寸分布的颗粒以及形成薄厚两种电极层的时候, 容易导致阻抗谱中出现第三个半圆.

关键词: 锂离子电池, 嵌入化合物, 非均匀, 多孔电极, 电化学阻抗谱

Abstract: Single intercalation particles, mixed particles, homogeneous porous electrodes and nonhomogeneous, multilayered porous electrode models are proposed in this paper. Some peculiar features of impedance spectra were simulated using the above-mentioned models. The results reveal that the features of impedance spectra of the single intercalation particle and the mixed particles are the same and the features consist of lithium ion migration through the solid electrolyte interphase (SEI) film (RSEICSEI semicircle), an electron and ion transfer process (RctCdl semicircle), and a finite-diffusion Warburg element. For the nonhomogeneous, multilayered porous electrodes model, a peculiar feature of impedance spectra is that a new arc appears in the Nyquist plot. A detailed analysis revealed that a different particle size distribution could lead to the appearance of a new arc and a different layer distribution (a thicker layer and a thinner layer), which could lead to a well-developed semicircle.

Key words: Lithium ion battery, Intercalation compound, Nonhomogeneous, Porous electrode, Electrochemical impedance spectroscopy

MSC2000: 

  • O646.54