Determination of electrochemical impedance of lithium-ion battery from charge curve by wavelet transformation
Determination of electrochemical impedance of lithium-ion battery from charge curve by wavelet transformation
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DOI：
10.1016/j.electacta.2022.140957
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发表时间：
2022-08-09
影响因子：
6.6
通讯作者：
Itagaki, Masayuki
中科院分区：
文献类型：
--
作者：
Watanabe, Hikari;Uemori, Miku;Itagaki, Masayuki
锂离子电池（LIBs）正被用作电动汽车和飞机等的电源。随着电动汽车和飞机的普及，对电池劣化的早期检测技术提出了更高的要求。电化学阻抗谱是评价锂离子电池内部状态的有效方法。最近，我们提出了一种通过对外部输入和输出信号进行小波变换来确定LIB阻抗谱的方法。在没有外部输入信号的情况下，通过对锂离子电池的电荷曲线进行小波变换，确定了锂离子电池的阻抗谱。小波变换确定的阻抗谱中出现电容性半圆和Warburg阻抗，与频响分析仪（FRA）测量的阻抗谱基本一致。此外，还将新的阻抗测定方法应用于劣化电池的评价。随着电池容量的衰减，半圆直径增大。对WT确定的光谱进行曲线拟合。随着容量损失的增加，与电极结构相关的电阻Rc和电荷转移电阻Rct的总和增加。此外，参数值与FRA测得的阻抗值吻合较好，表明这种新的阻抗测定方法可用于评价劣化电池。此外，我们强调该方法可以通过简单的充电来诊断电池劣化。
Lithium-ion batteries (LIBs) are being used as power sources for use in electric vehicles and aircraft, and so on. Early detection technique of battery deterioration is required with the spread adoption of electric vehicles and aircraft. Electrochemical impedance spectroscopy is a powerful method to evaluate the internal state of LIB. We recently have proposed a method to determine the impedance spectra of LIB by wavelet transformation (WT) of the external input and the output signals. In the present paper, the impedance spectra were determined by performing WT on the charge curves of the LIB without an external input signal. A capacitive semicircle and Warburg impedance appeared in the impedance spectrum determined by the WT, which is roughly consistent with the impedance spectrum measured by a frequency response analyzer (FRA). In addition, the new impedance determination method was applied to the evaluation of deteriorated batteries. The diameter of the semicircle increased with fading the battery capacity. Curve fitting was applied to the spectra determined by the WT. The sum of the resistance related to electrode structure, Rc, and the charge transfer resistance, Rct, increased as the capacity loss increased. Moreover, the parameter values were in good agreement with those calculated from the impedance measured using FRA, indicating that this new impedance determination method is useful for evaluation of deteriorated batteries. Furthermore, we emphasize that this method can diagnose the battery deterioration simply by charging the battery.