Energy Storage Science and Technology ›› 2022, Vol. 11 ›› Issue (7): 2324-2331.doi: 10.19799/j.cnki.2095-4239.2021.0725

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

Semi-empirical degradation model of lithium-ion battery with high energy density

Qingwei ZHU1(), Xiaoli YU2, Qichao WU2, Yidan XU2, Fenfang CHEN2, Rui HUANG2()   

  1. 1.Polytechnic Institute, Zhejiang University, Hangzhou 310015, Zhejiang, China
    2.College of Energy Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China
  • Received:2021-12-31 Revised:2022-01-13 Online:2022-07-05 Published:2022-06-29
  • Contact: Rui HUANG E-mail:qwzhu@zju.edu.cn;hrss@zju.edu.cn

Abstract:

The capacity of the battery will continue to fall as the cycle ages, and the internal resistance will progressively grow, affecting the battery's service life and performance. To establish the semi-empirical model of capacity decline and internal resistance growth and shorten the time required to investigate the battery aging characteristics, the 21700 lithium-ion battery with high energy density is adopted to conduct the cycle aging experiment of the battery under six working conditions at 0 ℃, 23 ℃, and 40 ℃ combined with 1 C and 2 C discharge rates. The effect of temperature and other environmental conditions on battery capacity reduction and internal resistance increase is investigated.

When the semi-empirical model of battery capacity decline is created by combining the Arrhenius equation, an additional power function and a constant term about the number of cycles are introduced, which can broaden the model's applicability and make it suitable for different capacity decline trends at different temperatures. A semi-empirical model of battery internal resistance growth is developed using the double exponential function multiplication formula, which can effectively predict the law of internal resistance growth under various working conditions. The cross-validation approach is used to demonstrate the accuracy of semi-empirical models of capacity decrease and internal resistance increase, which may be used to forecast the aging law of batteries at various temperatures. Finally, the semi-empirical model of battery aging is used to predict the capacity and internal resistance of the battery at 15 ℃, 30 ℃, and 45 ℃, allowing for a better understanding of the battery's aging characteristics while avoiding a large number of repeated experiments and increasing research efficiency.

Key words: lithium-ion battery, capacity decline, internal resistance growth, semi-empirical degradation model

CLC Number: