Energy Storage Science and Technology

   

SOH estimation of lithium-ion batteries based on multi-feature analysis and LSTM-XGBoost model

Jizhong Lu1(), Simin Peng2(), Xiaoyu Li3   

  1. 1.School of Electrical Engineering, Jiangsu Yancheng Technician College, Yancheng 224000
    2.School of Electrical Engineering, Yancheng Institute of Technology, Yancheng 224051
    3.School of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060
  • Received:2024-04-01 Revised:2024-04-11
  • Contact: Simin Peng E-mail:120322268@qq.com;psmsteven@163.com

Abstract:

Accurate assessment of the state of health (SOH) of lithium-ion batteries is critical to ensure the safe and stable operation of electric vehicles. However, traditional SOH estimation methods face some challenges in effectively extracting health features (HFs) and relying on large amounts of HFs test data. This paper proposes a SOH estimation method for lithium-ion batteries based on multi-feature analysis and the long short-term memory (LSTM)-eXtreme gradient boosting (XGBoost) model. First, to accurately describe the aging mechanism of the battery, a total of 6 HFs are extracted from the battery charging data in three categories: time, energy and IC. Considering a lot of redundant information among the same type of HFs, a feature processing method based on double correlation is presented to screen out the combined HFs that can accurately characterize the trend of battery degradation. Second, a SOH estimation model based on the LSTM-XGBoost is proposed to solve the problem that the traditional SOH estimation model requires a large amount of HFs test data. In this model, the LSTM algorithm is used to predict the HFs data of the number of battery remaining cycles. At the same time, in order to solve the problem of low computational efficiency in HFs prediction using the LSTM model, the LSTM-XGBoost model is developed to estimate battery SOH. The results show that the proposed method can accurately estimate the SOH of lithium batteries under different test data amounts, and the root-mean square error is kept within 1%, which has high estimation accuracy and robustness.

Key words: lithium-ion battery, State of health, Characteristic analysis, long short-term memory neural network, eXtreme gradient boosting

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