储能科学与技术 ›› 2021, Vol. 10 ›› Issue (1): 202-209.doi: 10.19799/j.cnki.2095-4239.2020.0249

• 储能测试与评价 • 上一篇    下一篇

大型磷酸铁锂电池高温热失控模拟研究

梅文昕1(), 段强领1, 王青山2,3, 李妍2,3, 李欣4, 朱金大4, 王青松1()   

  1. 1.中国科学技术大学,安徽 合肥 230026
    2.国网江苏省电力有限公司经济技术研究院,江苏 南京 210008
    3.国网江苏省电力有限公司,江苏 南京 210024
    4.国网电力科学研究院有限公司,江苏 南京 211000
  • 收稿日期:2020-07-15 修回日期:2020-09-10 出版日期:2021-01-05 发布日期:2021-01-08
  • 通讯作者: 王青松 E-mail:heart@mail.ustc.edu.cn;pinew@ustc.edu.cn
  • 作者简介:梅文昕(1995—),女,博士研究生,主要从事锂离子电池电化学-热-应力耦合模型的模拟研究,E-mail:heart@mail.ustc.edu.cn
  • 基金资助:
    国家电网公司总部科技项目(5400-201940486A-0-0-00)

Thermal runaway simulation of large-scale lithium iron phosphate battery at elevated temperatures

Wenxin MEI1(), Qiangling DUAN1, Qingshan WANG2,3, Yan LI2,3, Xin LI4, Jinda ZHU4, Qingsong WANG1()   

  1. 1.University of Science and Technology of China, Hefei 230026, Anhui, China
    2.Economic and Technological Research Institute of State Grid Jiangsu Electric Power Co. Ltd. , Nanjing 210008, Jiangsu, China
    3.State Grid Jiangsu Electric Power Co. Ltd. , Nanjing 210024, Jiangsu, China
    4.State Grid Electric Power Research Institute Co. Ltd, Nanjing 211000, Jiangsu, China
  • Received:2020-07-15 Revised:2020-09-10 Online:2021-01-05 Published:2021-01-08
  • Contact: Qingsong WANG E-mail:heart@mail.ustc.edu.cn;pinew@ustc.edu.cn

摘要:

高温是触发锂离子电池热失控的最直接原因,因此研究锂离子电池在高温加热中的热失控特征及其内在机制至关重要。本文选取109 A·h大型磷酸铁锂电池为研究对象,在COMSOL Multiphysics中建立了6种不同温度下(140 ℃、145 ℃、150 ℃、155 ℃、160 ℃、165 ℃)的烘箱热失控模型,模拟分析了电池在高温加热条件下的热失控特征和温度分布。研究结果表明在140 ℃和145 ℃时电池未发生热失控,其他工况下电池均发生热失控,且环境温度越高,电池发生热失控的时间越早,温升速率加快。此外,通过对热失控各副反应分解浓度分析得知,未发生热失控情况下只发生了SEI膜和负极的分解反应,而正极与电解液的反应是造成电池热失控的主要诱因。最后通过对比发生热失控和未发生热失控情况下电池的温度分布,发现未发生热失控条件下电池温度分布均匀,而发生热失控时电池温度均匀性变差。同时发现高环境温度下电池的热失控更为剧烈,温度分布极不均匀,且在热失控前后温度分布变化较快,预计电池材料发生的不可逆分解反应是导致电池损坏的主要原因。

关键词: 锂离子电池安全, 磷酸铁锂, 高温热失控模型, 副反应, 温度分布

Abstract:

Elevated temperature is the most direct trigger of thermal runaway in lithium-ion batteries, so it is crucial to study the thermal runaway characteristics and mechanism of lithium-ion batteries at elevated temperatures. This paper presents the study of 109 A·h large-scale lithium iron phosphate power batteries, and an oven thermal runaway model at six different temperatures (140 ℃, 145 ℃, 150 ℃, 155 ℃, 160 ℃, 165 ℃) is presented via COMSOL Multiphysics software to simulate the thermal runaway characteristics and temperature distribution of the battery under high temperatures. The studies showed that the battery does not trigger thermal runaway at temperatures of 140 ℃ and 145 ℃, but does trigger thermal runaway at higher temperatures. The higher the oven temperature, the earlier the thermal runaway occurs, and the rate of temperature rise is also accelerated. Through the analysis of the decomposition concentration of each side reaction in the thermal runaway, it is observed that only the decomposition of the solid electrolyte interphase layer and anode occurred in the non-thermal runaway cases. The reaction between the cathode and the electrolyte is the main cause of thermal runaway. Finally, by comparing the thermal runaway cases with the non-thermal runaway cases, it was found that the temperature distribution of the battery is uniform in the case of a non-thermal runaway, while the temperature uniformity is poor in the case of a thermal runaway. At higher temperatures, the thermal runaway of the battery is more severe, where the temperature distribution is extremely uneven and changes rapidly before and after thermal runaway. In such thermal runaways, it is predicted that the electrode materials have undergone irreversible decomposition leading to battery damage.

Key words: lithium ion battery safety, lithium iron phosphate, oven thermal runaway model, side reaction, temperature distribution

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