汽车工程 ›› 2025, Vol. 47 ›› Issue (6): 1103-1111.doi: 10.19562/j.chinasae.qcgc.2025.06.009

• • 上一篇    

微正压氮气抑制大容量磷酸铁锂电池包热失控实验研究

李师1,2,贾壮壮1,沈光杰2,王青松1,孙金华1()   

  1. 1.中国科学技术大学,火灾科学国家重点实验室,合肥 230026
    2.郑州深澜动力科技有限公司,郑州 450000
  • 收稿日期:2024-12-10 出版日期:2025-06-25 发布日期:2025-06-20
  • 通讯作者: 孙金华 E-mail:sunjh@ustc.edu.cn
  • 基金资助:
    第二十七届中国科协年会学术论文。广东省重点领域研发计划项目(2024B1111080001)

An Experimental Study on Suppressing Thermal Runaway of Large-Capacity Lithium Iron Phosphate Battery Pack by Micro-Positive Pressure Nitrogen

Shi Li1,2,Zhuangzhuang Jia1,Guangjie Shen2,Qingsong Wang1,Jinhua Sun1()   

  1. 1.University of Science and Technology of China,State Key Laboratory of Fire Science,Hefei 230026
    2.Zhengzhou Shenlan Power Technology Co. ,Ltd. ,Zhengzhou 450000
  • Received:2024-12-10 Online:2025-06-25 Published:2025-06-20
  • Contact: Jinhua Sun E-mail:sunjh@ustc.edu.cn

摘要:

磷酸铁锂电池具有循环寿命长、安全性能高等优势,在商用电动汽车上得到广泛应用,但是,磷酸铁锂电池在使用过程中仍有可能发生热失控事故。为抑制磷酸铁锂电池包内火灾事故扩大,提出一种高效、易操作且成本低的磷酸铁锂电池包内热失控抑制技术,即在磷酸铁锂电池包内注入微正压氮气抑制电池热失控。通过开展有无微正压氮气抑制电池包内电池模组热失控实验和电池包内凝露实验,系统地分析了微正压氮气抑制电池包热失控的效果和可行性。实验结果表明:(1)无抑制措施工况下,电池模组在140 s内全部热失控,电池持续燃烧413 s,电池表面最高温度为627.6 ℃,电池包的绝缘阻值为43.7 MΩ,降低了95%,电池包内相对湿度增加约200%。(2) 在微正压氮气抑制工况下,电池模组仅有一个电池防爆阀打开,且开阀时间比无抑制措施迟526 s,电池表面最高温度为148 ℃,综合判断电池模组没有发生热失控;微正压氮气条件下,电池包内无凝露,并有效抑制了电池包的呼吸效应,降低了电池包内发生绝缘短路等次生灾害的风险。本研究为大容量磷酸铁锂电池包的设计与安全防控技术提供了新的研究思路。

关键词: 磷酸铁锂电池包, 微正压, 氮气, 热失控

Abstract:

Lithium iron phosphate (LFP) battery features a long lifetime and high safety, which is widely used in electric commercial vehicles. However, thermal runaway accidents may still occur during its use. To inhibit the expansion of fire in LFP battery packs, an efficient, easy-to-operate and low-cost internal thermal runaway suppression technology is proposed, that is, injecting micro-positive pressure nitrogen into battery packs. The effect and feasibility of this technology are systematically analyzed by module thermal runaway tests of packs with/without micro-positive pressure nitrogen and the condensation test in the pack. The test results show that: (1) Under the condition of no suppression measures, the thermal runaway of all modules occurs within 140 s, and the battery burns continuously for 413 s, with a maximum surface temperature of 627.6 °C. The insulation resistance of the battery pack is 43.7 MΩ, reduced by 95%, and the internal relative humidity increasing by about 200%. (2) Under the condition of micro-positive pressure nitrogen suppression, only one battery explosion-proof valve of the battery module is opened, with the opening time 526 s later than that without nitrogen, and the maximum temperature on the battery surface is 148 ℃, so it is comprehensively judged that there is no thermal runaway in the battery module. Under the condition of micro-positive pressure nitrogen, there is no condensation in the pack, which effectively inhibits the respiration effect and reduces the risk of secondary disasters such as an insulation short circuit in the pack. This study provides new research ideas for the design and safety prevention and control technology of high-capacity lithium iron phosphate battery packs.

Key words: lithium iron phosphate battery pack, micropositive atmospheric, nitrogen environment, thermal runaway