Energy Storage Science and Technology ›› 2022, Vol. 11 ›› Issue (2): 679-689.doi: 10.19799/j.cnki.2095-4239.2021.0408

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

Discharge performance and charge-discharge heat generation characteristics of aging batteries

Bing CHEN1,2,3(), Lili ZHENG1,2,3, Xichao LI4, Yan FENG1,2,3, Zhuo XU1,2,3, Zuoqiang DAI1,2,3()   

  1. 1.College of Mechanical and Electrical Engineering, Qingdao 260071, Shandong, China
    2.Engineering Technology Center of Power Integration and Energy Storage System, Qingdao University, Qingdao 260071, Shandong, China
    3.National and Local Joint Engineering Technology Center for Intelligent Power Integration Technology for Electric Vehicles (Qingdao), Qingdao 260071, Shandong, China
    4.Energy storage division of CRRC Qingdao Sifang Vehicle Research Institute Co. , Ltd, Qingdao 260071, Shandong, China
  • Received:2021-08-06 Revised:2021-10-12 Online:2022-02-05 Published:2022-02-08
  • Contact: Zuoqiang DAI E-mail:1504847530@qq.com;daizuoqiangqdu@163.com

Abstract:

Currently, the aging performance degradation of vehicle power batteries is becoming increasingly prominent, and their performance after aging is concerning. In this study, a 18650-type ncm811 lithium-ion battery was used as the research object to study the discharge performance and charge-discharge heat generation characteristics after aging. The performance change of the battery after aging is explained by taking the corresponding performance parameters of the new battery of the same model as the reference. The battery's discharge performance was evaluated at varying ambient temperatures and discharge rates. The discharge voltage curve, discharge capacity, and temperature variation of the battery's outer surface during discharge were obtained. The battery's thermal power and heat production during charging and discharging were measured using an isothermal adiabatic calorimeter. The results show that at 25 ℃, the discharge capacity of the aged battery accounts for 72%, 69.5%, 66.2%, and 62.2% of that of the new battery at 0.2 C, 0.5 C, 1 C, and 2 C, and the aged battery's surface temperature increase is 147%, 208%, 331%, and 138%, respectively, of that of the new battery. At 0.5 C, -20 ℃, -10 ℃, 0 ℃, 20 ℃, and 40 ℃, the aging battery's capacity is 57.5%, 63.4%, 66.9%, 69.5%, and 69.3% of that of the new battery, and the aging battery's temperature increase is 91%, 120%, 106%, 208%, and 146%, respectively, of that of the new battery. During charging and discharging, the aging battery's heat production power and heat production are larger than that of the new battery. However, because the aging battery's charging and discharging times are sometimes short, its heat production power or heat production is smaller than that of the new battery.

Key words: cyclic aging, ambient temperature, discharge doubling rate, heat production power, heat production

CLC Number: