锂电池健康状态快速测量及系统实现

Rapid Measurement and System Realization of State of Health of Lithium Battery

为实现大规模退役锂电池的梯次利用,需要快速测量锂电池的健康状态;基于EIS的低频阻抗测量不仅耗时长,而且针对电池等效电路的还需要做复杂的参数估计,因此,建立了锂电池扩散过程健康因子与低频阻抗的关系,结合扩散过程健康因子和锂电池直流内阻以快速评估锂电池健康状态;其次,设计和构建快速测量系统以测量低频阻抗和直流内阻;实验结果表明,可通过测量扩散过程健康因子和直流内阻判断锂电池健康状态,测量过程仅需花费三分钟的时间,而且准确性较高,快速测量系统可应用于各个实际的工业现场,实现了集快速性、准确性、经济性于一体的目标。

In order to realize the echelon utilization of large-scale decommissioned lithium batteries,it is necessary to quickly measure the state of health(SoH)of lithium batteries.Low frequency impedance measurement based on electrochemical impedance spectrum(EIS)is not only time-consuming,but also requires complex parameter estimation for the equivalent circuit of battery.Therefore,the relationship between health factors in the diffusion process of lithium battery and the low frequency impedance of lithium battery is established.Health factors in the diffusion process of lithium battery and the direct current(DC)internal resistance of lithium battery are combined to rapidly evaluate the health status of lithium batteries.In addition,a rapid measurement system for measuring the low frequency impedance and DC internal resistance is designed and built.The experimental results show that health factors in the diffusion process and the DC internal resistance can be measured to judge the SoH of lithium battery.The measurement process only spends three minutes,and the accuracy of measurement is high.The rapid measurement system can be applied to all practical industrial sites,which realizes the goals of quickness,accuracy and economy.