Energy Storage Science and Technology ›› 2025, Vol. 14 ›› Issue (6): 2498-2511.doi: 10.19799/j.cnki.2095-4239.2025.0021

• Energy Storage Test: Methods and Evaluation • Previous Articles     Next Articles

Lithium-ion batteries SOH estimation based on gaussian processed regression optimized by egret swarm optimization

Chunling WU1,2(), Liding WANG1,2, Yong LU1,2, Limin GENG1,2, Hao CHEN1,2, Jinhao MENG3   

  1. 1.School of Energy and Electrical Engineering, Chang'an University, Xi'an 710064, Shaanxi, China
    2.Shaanxi Key Laboratory of Transportation New Energy Development, Application and Vehicle Energy Saving Technology, Xi'an 710061, Shaanxi, China
    3.School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, China
  • Received:2025-01-04 Revised:2025-01-22 Online:2025-06-28 Published:2025-06-27
  • Contact: Chunling WU E-mail:wuchl@chd.edu.cn

Abstract:

Accurate estimation of the state of health (SOH) of lithium-ion batteries is essential for ensuring the safety and reliability of battery systems and is a critical function of battery management systems. To address the limitations of existing data-driven SOH estimation methods—such as inadequate representation of uncertainty and insufficient decoupling of training and testing data—this study proposes a novel approach based on Gaussian process regression (GPR) optimized by the egret swarm optimization algorithm (ESOA). Health features related to battery aging are extracted from the charging voltage, current, and relaxation voltage data of similar batteries, and features with high correlation to capacity are selected using Pearson correlation analysis. A GPR model employing a squared exponential kernel is then used for SOH estimation, with its hyperparameters optimized via ESOA. The proposed method is validated using NCA and NCM battery datasets from Tongji University. Experimental results show that the method significantly improves estimation accuracy and robustness. For the tested batteries, the maximum root mean square error (RMSE) and mean absolute error (MAE) are 0.0028 and 0.22%, respectively, representing improvements of 58.82% and 57.69% over conventional GPR models. Additionally, the method enables SOH interval estimation, reducing the risk of safety hazards from overestimation.

Key words: lithium-ion battery, state of health, egret swarm optimization algorithm, Gaussian process regression, interval estimation

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