Energy Storage Science and Technology ›› 2023, Vol. 12 ›› Issue (7): 2202-2210.doi: 10.19799/j.cnki.2095-4239.2023.0333

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Research on battery sorting technology for echelon utilization based on multifrequency impedance

Maosong FAN1(), Mengmeng GENG1, Guangjin ZHAO2, Kai YANG1(), Fangfang WANG2, Hao LIU1   

  1. 1.China Electric Power Research Institute, Beijing 100192, China
    2.State Grid Henan Electric Power Research Institute, Zhengzhou 450052, Henan, China
  • Received:2023-05-09 Revised:2023-06-02 Online:2023-07-05 Published:2023-07-25
  • Contact: Kai YANG E-mail:fanmaosong3@epri.sgcc.com.cn;yangkai@epri.sgcc.com.cn

Abstract:

Retired batteries must be resorted before echelon utilization, enabling them to meet the requirements of application scenarios for battery performance. The high cost of battery sorting for echelon utilization has become a technical bottleneck limiting its large-scale application. To reduce the cost of sorting and improving the technical and economic efficiency of battery echelon utilization, this study first studies the AC impedance characteristics of echelon-utilization batteries in different states, extracts characteristic frequency points to characterize battery states, and establishes a multifrequency point-based state of health (SOH) evaluation model for echelon utilization. Then, for developing a new model for echelon-utilization batteries, the model is optimized by testing the AC impedance and SOH data of a small number of samples. Finally, the open circuit voltage, multifrequency impedance, and estimated capacity were used as parameters for echelon-utilization battery sorting and compared with traditional sorting methods. The experimental results show that the maximum error of the optimized model in evaluating the SOH of the new battery model is within 3% and the MAPE is 1.93%, i.e., there is a significant reduction in the evaluation error compared to the unoptimized model. The cycling performance of battery pack sorting using this method is very close to that of traditional methods, which verifies the effectiveness of this sorting method. Moreover, this method can considerably shorten the sorting time of echelon-utilization batteries and has good engineering application value.

Key words: lithium-ion battery, echelon utilization, AC impedance spectroscopy, sorting technology

CLC Number: