Energy Storage Science and Technology ›› 2025, Vol. 14 ›› Issue (9): 3599-3610.doi: 10.19799/j.cnki.2095-4239.2025.0033

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

State-of-health assessment of lithium batteries using variational mode decomposition and feature enhancement under capacity regeneration phenomena

Wuzhe ZHANG1(), Zhiduan CAI2,3(), Chengao WU1, Wei ZHENG1, Jiayang TONG2   

  1. 1.School of Engineering, Huzhou University
    2.School of Intelligent Manufacturing, Huzhou University
    3.Huzhou Key Laboratory of Green Energy Materials and Battery Cascade Utilization, Huzhou 313000, Zhejiang, China
  • Received:2025-01-08 Revised:2025-01-13 Online:2025-09-28 Published:2025-09-05
  • Contact: Zhiduan CAI E-mail:1035176174@qq.com;caizhiduan@zjhzu.edu.cn

Abstract:

Owing to their high energy density and long life cycle, lithium batteries have been widely used in electric vehicles, energy storage systems, and portable devices. However, capacity regeneration is an inevitable phenomenon during battery use, which influences the accuracy of battery health assessment. To reduce the influence of capacity regeneration on assessment accuracy, a new method combining variational mode decomposition and a generative adversarial network is proposed. First, variational mode decomposition is applied to decompose the iso-pressure-drop discharge-time characteristic, which reflects the capacity regeneration phenomenon during lithium battery discharge. The main degradation-trend component and local fluctuation component are then separated using Pearson correlation coefficient analysis, enabling a better characterization of battery health. The main degradation-trend component represents the overall degradation of the battery, while the local fluctuation component captures the variations caused by capacity regeneration. Second, to further enhance the features related to local wave components and the capacity regeneration phenomenon, a Fourier transform is used to extract the mid- and low-frequency components that reflect capacity regeneration. For components in these frequency bands, a generative adversarial network is employed to generate additional data. These generated data are then combined with the multifeature set obtained from variational mode decomposition to form a new, enriched multifeature set. Next, a support vector machine algorithm is used to train this new multifeature set to achieve accurate estimation of the battery's state of health. Finally, validation experiments are conducted using NASA and CALCE datasets. The experimental results show that, compared with traditional methods, the proposed method keeps the root-mean-square error within 4.5%, effectively reducing the influence of capacity regeneration on battery health assessment accuracy.

Key words: capacity regeneration, local fluctuation component, Fourier transform, support vector machine

CLC Number: