嵌入化合物电极的电化学阻抗谱模型与理论模拟.pdf

物理化学学报( li Huaxue Xuebao)
October
Acta Phy:s.-Chim.Sin.2011,27(10),2353-2359
2353
Article
thxb. pku.edu. cn
嵌入化合物电极的电化学阻抗谱:模型与理论模拟
徐守冬2庄全超史月丽1朱亚波12邱祥云12孙智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2211
中国矿业大学化学工程学院,江苏徐州221115
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(SE)膜过程相关的 Rse CSE半圆,与电荷传递过程
相关的 R Ca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
电枚而言,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す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:镈离子电池;嵌入化合物;非均匀;多孔电极;电化学阻抗谱
中图分类号:O646.54
Electrochemical Impedance Spectra of ntercalation Compound
Electrodes: Models and Theoretical Simulations
XU Shou-dong ZHUANG Quan-chao"SHI Yue-li ZHU YA-BO
QIU Xiang-y
SUN Z
(li-ion Batteries Laboratory, School of Materials Science and Engineering, China University of Mining and Technology, Xuzho
2211/,iangsu Province, P R. China: School of Chemical Engineering and Technology, China University of Minin and
Technology, Xuzhou 221116, Jiangsu Province, P R. China
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 onsist of li ium on mian ouh the solid elec rolyte interphase(E film(Rs Cs
semicircle), an electron and ion transfer process(Ra Ca semicircle), and a finite-diffusion Warburg
element For the nonhomogeneous, multilayered porous elec roes 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
Received: May 4, 2011; Revised: July 12, 2011; Published on Web: August 15, 2011
Correspondingauthoremail:zhuangquanchao(@126.com;Tel+86-13605215324
The project was supported by the Fundamental Research Funds for the Central Universities, China(2010LKHX03, 2010QNB04, 2010QNB05)
Sciencc and Technology"Climbing " Pro ram of CUMT, China( ON090237)and Natural Science Foundation of Jiangsu Province, China
(BK20087129)
中央高校基本科研业务费专项资金(2010 LKKX03,2010QNB04,2010QNBO5),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
C Editorial office of Acta Physico-chimica Sinica