基于电化学阻抗谱的锂离子电池过放电诱发内短路的检测方法  

Detection Method of Overdischarge-Induced Internal Short Circuit in Lithium-Ion Batteries Based on Electrochemical Impedance Spectroscopy

作　　者：张闯[1,2] 王泽山 刘素贞[1,2] 金亮[1,2] 杨庆新[1] Zhang Chuang;Wang Zeshan;Liu Suzhen;Jin Liang;Yang Qingxin(State Key Laboratory of Reliability and Intelligence of Electrical Equipment Hebei University of Technology ,Tianjin 300130 China;Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province Hebei University of Technology ,Tianjin 300130 China)

机构地区：[1]省部共建电工装备可靠性与智能化国家重点实验室(河北工业大学),天津300130 [2]河北省电磁场与电器可靠性重点实验室(河北工业大学),天津300130

出　　处：《电工技术学报》2023年第23期6279-6291,6344,共14页Transactions of China Electrotechnical Society

基　　金：电力系统国家重点实验室课题(SKLD21KZ04);河北省中央引导地方科技发展专项(216Z4406G)资助项目。

摘　　要：锂离子电池内短路(ISC)是电池发生热失控的主要原因,电池内短路尤其是过放电导致的内短路初期产热不明显,电压变化小,很难通过常规的观察电、热特征的方法对其进行检测。随着电池内短路的演化,电池内部结构逐渐发生改变,这些电池内部的变化可以在对电池具有良好表征性的电化学阻抗谱中得到体现。该文分别对不同荷电状态(SOC)、不同温度和不同内短路程度的电池进行电化学阻抗谱的测量和研究,筛选检测电池内短路所需的特征参数。结果表明,电池电化学阻抗谱的欧姆电阻R_o基本不受电池温度(25~45℃)、SOC的影响,但是对电池内短路程度较为敏感。为便于检测,该文选择电化学阻抗谱中参数特性和大小都基本和欧姆电阻一致的1 000 Hz频率阻抗的实部作为特征参数,通过监测电池循环过程中特征参数变化趋势来判断电池是否发生内短路。经实验验证,监测1 000 Hz频率阻抗实部值变化的方法可有效检测出电池过放电诱发的内短路,该方法不影响电池的正常循环使用,限制条件少且准确性高。Internal short circuit(ISC)in lithium-ion batteries is the main cause of thermal runaway,timely and accurate detection of internal short circuit is of great importance in ensuring personal and property safety.ISC of batteries,especially the one caused by over-discharge,produces insignificant heat and small voltage changes,making it difficult to be detected through conventional observation of electrical and thermal characteristics.As ISC evolves and deepens,the battery's internal structure gradually changes,and these subtle changes can be reflected in electrochemical impedance spectroscopy(EIS),which is a good characterization technique for batteries.However,the current methods for detecting ISC induced by over-discharge based on electrochemical impedance spectroscopy do not consider the strict measurement conditions of electrochemical impedance,and changes in temperature and state of charge(SOC)in actual battery applications can affect the accuracy of detection.Therefore,this paper proposes an EIS-based detection method for ISC induced by over-discharge of lithium-ion batteries which is not affected by temperature(25~45℃)and SOC and can accurately detect internal short circuit induced by the overdischarge of the battery.Firstly,electrochemical impedance spectroscopies of the experimental batteries were measured,and an equivalent circuit model was established based on the characteristics of measured electrochemical impedance spectroscopies.Secondly,the electrochemical impedance spectroscopies of lithium-ion batteries were measured at different temperatures,different SOC and different degrees of ISC,the relevant fitting parameters were obtained by fitting the electrochemical impedance with the equivalent circuit model.Parameters that were sensitive to the degrees of ISC but not affected by battery temperature and SOC were selected as characteristic parameters.Finally,the detection method was designed based on the characteristic parameters,and the validation experiment is completed.The results of experiments show

关 键 词：锂离子电池 内短路 电化学阻抗谱 过放电 特征参数 

分 类 号：TM911[电气工程—电力电子与电力传动]