Energy Storage Science and Technology ›› 2023, Vol. 12 ›› Issue (6): 1995-2010.doi: 10.19799/j.cnki.2095-4239.2023.0016

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

Overview of SOC estimation methods for lithium-ion batteries based on model

Birong TAN1,2(), Jianhua DU1,2(), Xianghu YE1,2, Xin CAO1,2, Chang QU1,2   

  1. 1.Key Laboratory of Process Monitoring and System Optimization for Mechanical and Electrical Equipment, Huaqiao University
    2.College of Mechanical Engineering and Automation, Huaqiao University, Xiamen 361021, Fujian, China
  • Received:2023-02-06 Revised:2023-02-24 Online:2023-06-05 Published:2023-06-21
  • Contact: Jianhua DU E-mail:tanbirong185@163.com;dujh@hqu.edu.cn

Abstract:

Lithium-ion batteries are extensively used in electric energy storage and new vehicles due to their high energy density and long cycle life. Accurate estimation of the battery's state of charge(SOC) is crucial for improving its service life and utilization efficiency. However, lithium batteries are a highly complex, time-varying, and nonlinear electrochemical system. Thus, an online SOC estimation method with high accuracy is vital for the practical application of lithium batteries. In recent years, model-based SOC estimation methods have gained widespread attention and research because of their closed-loop control and ease of implementation. This paper reviews model-based SOC estimation methods from the aspects of model classification, model parameter identification algorithm, SOC estimation algorithms, and factors influencing SOC estimation. First, various common lithium-ion battery models are summarized, primarily focusing on introducing and comparing common electrochemical and equivalent circuit models. Then, the model establishment methods and SOC state estimation algorithms are examined and compared; various model parameter identification methods and SOC estimation calculation methods are introduced and contrasted. After that, the influencing factors and solutions of the model-based SOC estimation method are analyzed and summarized, mainly addressing the impact of temperature, aging, and battery pack factors on battery SOC estimation. Finally, potential future research directions are discussed and explored.

Key words: lithium-ion batteries, equivalent circuit model, electrochemical model, state of charge, online estimation

CLC Number: