电化学阻抗谱识别不同化学体系退役动力锂离子电池  

Identification of retired power lithium-ion batteries of chemical systems by electrochemical impedance spectroscopy

作　　者：王放放 冯祥明[2] 赵光金 夏大伟 胡玉霞 陈卫华[2] WANG Fangfang;FENG Xiangming;ZHAO Guangjin;XIA Dawei;HU Yuxia;CHEN Weihua(State Grid Henan Electric Power Research Institute,Zhengzhou 450052,Henan,China;Green Catalysis Center,College of Chemistry,Zhengzhou 450001,Henan,China)

机构地区：[1]国网河南省电力公司电力科学研究院,河南郑州450052 [2]郑州大学化学学院,河南郑州450001

出　　处：《储能科学与技术》2023年第2期609-614,共6页Energy Storage Science and Technology

基　　金：国网河南省电力公司电力科学研究院项目(退役磷酸铁锂动力电池单体快速状态评估技术研究和装置开发)。

摘　　要：退役动力锂离子电池梯次利用可充分提高动力电池的经济性,然而目前动力电池标识信息混乱、电池荷电状态差异和工作电压重叠均导致无法直接或依据开路电压准确分辨磷酸铁锂动力电池与镍钴锰三元动力电池。为此,基于动力锂离子电池的结构和等效电路,建立了容量与动力电池界面电容、反应电阻、韦伯阻抗和液相电阻的对应关系,通过分析动力电池容量对电化学阻抗实部和虚部的影响探讨了利用阻抗法快速识别退役动力锂离子电池化学体系的可能性。结果表明电化学阻抗实部与虚部的比值与电池容量无关,据此可利用该比值随频率的变化差异快速识别不同化学体系的动力锂离子电池,从而避免依据充放电判断电池化学体系的低效率。此外,软包装磷酸铁锂和镍钴锰三元电池的测试结果也表明10 Ah、12.5 Ah和50 Ah的磷酸铁锂电池阻抗虚部与实部比值随交流信号频率的变化基本相同,但与镍钴锰三元电池明显不同,初步验证了该方法的有效性。The economic efficiency of power batteries can be enhanced by the cascade utilization of retired lithium-ion batteries.However,the confusion of batteries’identification information,the difference in charge state,and the overlap of working voltage make it extremely difficult and unreliable to distinguish LiFePO4and Ni-Co-Mn oxide-based power batteries by judging only the open-circuit voltage.Therefore,electrochemical impedance spectroscopy(EIS)was employed as a rapid and nondestructive method to identify the power lithium-ion batteries of chemical systems by establishing the dependences among the capacity,interfacial capacitances,reaction resistances,Warburg impedances,and liquid resistance and then investigating the influence of capacity on the real and imaginary parts of electrochemical impedance based on the equivalent circuit of power lithium-ion batteries.The investigation showed that the ratio of the real part to the imaginary part was independent of the capacity.Consequently,the intrinsic feature only involving EIS frequency could be used to quickly identify the power lithium-ion batteries of different chemical systems,avoiding the poor efficiency of charge and discharge routes.Further,the effectiveness of the EIS method was rudimentarily verified with pouch LiFePO4and Ni-Co-Mn oxide-based batteries.As a result,LiFePO4-based power batteries with capacities of 10,12,and 50 Ah showed that the ratio only varied with EIS frequency and considerably contrasted from those of Ni-Co-Mn oxide-based batteries.

关 键 词：动力锂离子电池 电化学阻抗谱 磷酸铁锂 镍钴锰酸锂 

分 类 号：TM911[电气工程—电力电子与电力传动]