Evaluation of the Electrochemical Characterizations of Lithium-Ion Battery (LIB) Slurry with 10-Parameter Electrical Equivalent Circuit (EEC)
Evaluation of the Electrochemical Characterizations of Lithium-Ion Battery (LIB) Slurry with 10-Parameter Electrical Equivalent Circuit (EEC)
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DOI：
10.1149/2.1421614jes
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发表时间：
2017
影响因子：
3.9
通讯作者：
Zhilong Wang;Tong Zhao;Jiafeng Yao;Yusei Kishikawa;M. Takei
中科院分区：
文献类型：
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作者：
Zhilong Wang;Tong Zhao;Jiafeng Yao;Yusei Kishikawa;M. Takei
采用10参数等效电路（10-parameter EEC）对PVDF-NMP溶液、无炭黑（CB）浆料和有炭黑（CB）浆料组成的三种样品在不同组分重量比下的锂离子电池（LIB）浆料的电阻、电抗和弛豫频率等电化学特性进行了评价。结合LIB浆料的内部结构和3种样品的电化学响应，构建了10参数的EEC。通过对电化学阻抗谱（EIS） Nyquist和Bode图与10参数电阻抗曲线的拟合，得到了四个结论。首先，10参数EEC = 14.3%的标准差S比常规8参数EEC = 30.6%的标准差S = 16.3%。其次，随着LiCoO2颗粒重量比wtLiCoO2的增加，电双层（EDL） Rdl的电阻先增大后减小，LiCoO2- pvdf比值效应可以很好地解释这一现象。PVDF-NMP溶液RSO电阻和导电路径Rp电阻分别为LiCoO2-NMP界面分散电阻和PVDF-NMP溶液在LIB浆液中的分散电阻。最后，EIS实验得到的LiCoO2-NMP界面色散弛豫频率、高色散频率和PVDF-NMP溶液色散弛豫频率、低色散频率可以用10参数EEC计算得到的frelax1和frelax2的弛豫频率来表示。©2016电化学学会。[DOI: 10.1149/2.1421614jes]版权所有
A 10-parameter Electrical Equivalent Circuit (10-parameter EEC) has been proposed to evaluate the electrochemical characterizations which are resistance, reactance and relaxation frequency of Lithium-ion battery (LIB) slurry under different components weight ratio of three samples composed of PVDF-NMP solution, Carbon Black (CB) absent slurry and CB present slurry. The 10-parameter EEC is constructed by combining the internal structure of LIB slurry and the electrochemical responses of three samples. Four conclusions are clarified by fitting Electrochemical Impedance Spectroscopy (EIS) Nyquist and Bode plots with the 10-parameter EEC. Firstly, the standard deviation S of the 10-parameter EEC = 14.3% is lower than that of a conventional 8-parameter EEC = 30.6% by S = 16.3%. Secondly, the resistance of electric double layer (EDL) Rdl is firstly increased and then decreased as LiCoO2 particles weight ratio wtLiCoO2 is increased, which is well explained by LiCoO2-PVDF ratio effect. Thirdly, the resistances of PVDF-NMP solution RSO and conductive path Rp are the resistances of LiCoO2-NMP interface dispersion and PVDF-NMP solution dispersion in LIB slurry. Lastly, relaxation frequencies of LiCoO2-NMP interface dispersion frelax,high and PVDF-NMP solution dispersion frelax,low obtained from EIS experiment can be represented by those of frelax1 and frelax2 calculated from the 10-parameter EEC. © 2016 The Electrochemical Society. [DOI: 10.1149/2.1421614jes] All rights reserved.