储能科学与技术 ›› 2025, Vol. 14 ›› Issue (2): 636-647.doi: 10.19799/j.cnki.2095-4239.2024.0764

• 储能系统与工程 • 上一篇    下一篇

100 Ah磷酸铁锂软包电池的热失控特性及产气行为

叶锦昊1(), 侯军辉2(), 张正国1,3, 凌子夜1,3, 方晓明1,3(), 黄思林2, 肖质文2   

  1. 1.华南理工大学传热强化与过程节能教育部重点实验室，广东 广州 510640
    2.厦门新能安科技有限公司，福建 厦门 361100
    3.广东省热能高效储存与利用工程技术研究中心，广东 广州 510640
  • 收稿日期:2024-08-14 修回日期:2024-10-15 出版日期:2025-02-28 发布日期:2025-03-18
  • 通讯作者: 侯军辉,方晓明 E-mail:2216410337@qq.com;HouJH@Ampacetech.com;cexmfang@scut.edu.cn
  • 作者简介:叶锦昊（2001—），男，硕士研究生，研究方向为电池热失控，E-mail：2216410337@qq.com；
  • 基金资助:
    国家自然科学基金(22078105)

Thermal runaway characteristics and gas generation behavior of 100 Ah lithium iron phosphate pouch cell

Jinhao YE1(), Junhui HOU2(), Zhengguo ZHANG1,3, Ziye LING1,3, Xiaoming FANG1,3(), Silin HUANG2, Zhiwen XIAO2   

  1. 1.Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, Guangdong, China
    2.Xiamen Ampace Technology Limited, Xiamen 361100, Fujian, China
    3.Guangdong Engineering Technology Research Center of Efficient Heat Storage and Application, Guangzhou 510640, Guangdong, China
  • Received:2024-08-14 Revised:2024-10-15 Online:2025-02-28 Published:2025-03-18
  • Contact: Junhui HOU, Xiaoming FANG E-mail:2216410337@qq.com;HouJH@Ampacetech.com;cexmfang@scut.edu.cn

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摘要：

本研究以100 Ah磷酸铁锂软包电池为研究对象，通过侧面加热触发热失控，借助工业计算机断层扫描(CT)、扫描电子显微技术(SEM)、气相色谱仪(GC)等表征测试手段，系统分析了40%、60%、80%、100%SOC下电池的热失控特性和产气变化规律。结果表明，电池热失控的过热触发可细分为四个阶段：过热温度升高、副反应膨胀产气、隔膜收缩与破裂冒烟、热失控引起剧烈温升和产气。进一步计算了产热能量，发现100%、80%、60%、40%SOC电池的峰值产热率分别达到140.34、115.44、14.76和3.91 kW，且100%SOC时释放的能量相当于104.63 g三硝基甲苯(TNT)的能量，破坏半径达到5.90 m，相比40%SOC的危险性提升了64.3%。对热失控后电池材料表征发现，正极磷酸铁锂材料从方块状转变为团聚的不规则球状，负极石墨结构则从层状转变为团聚的球形颗粒，这归因于内部副反应的加剧。通过对比产气特性发现，SOC的增加导致电池产H2量增加，CO2量下降，各SOC下电池产气的爆炸风险均高于普通烃类气体，爆炸上限呈现先下降后上升的变化趋势。本研究结果对后续储能系统的安全设计提供了理论依据和实践指导。

关键词: 大容量, 热失控, 磷酸铁锂软包电池, 残骸特征, 产气

Abstract:

This study focuses on 100 Ah lithium iron phosphate pouch cells, triggering thermal runaway by side heating. By utilizing industry characterization tools such as Industrial Computer Tomography, Scanning Electron Microscopy, and Gas Chromatography, the thermal runaway characteristics and gas evolution patterns at 40%, 60%, 80%, and 100% SOC were systematically analyzed. The results show that the overheating trigger of battery thermal runaway can be subdivided into four stages: increased overheating temperature; by-product reaction gas expansion; separator shrinkage and cracking with smoke emission; and thermal runaway caused by severe temperature rise and gas production. Further calculation of heat generation energy revealed that at 100%, 80%, 60%, and 40% SOC, the peak heat generation rates reached 140.34, 115.44, 14.76, and 3.91 kW, respectively, and the energy released at 100% SOC is equivalent to 104.63 grams of TNT, with a destructive radius reaching 5.90 meters, representing nearly a 64.3% increase in hazard compared to that at 40% SOC. Characterization of battery materials post-thermal runaway indicated that the LFP cathode material transformed from a block shape to aggregated irregular spheres, and the graphite anode structure was transformed from layered to aggregated spherical particles due to accentuated internal side reactions. A comparison of gas evolution characteristics showed that with increased SOC, the amount of H2 produced by the battery increased, while the amount of CO2 decreased. The explosion risk of the gases produced at various SOC levels is higher than that of Common hydrocarbon gases, with the explosion upper limit first decreasing and then increasing. The findings from this study provide a theoretical basis and practical guidance for the safety design of follow-up energy storage systems.

Key words: large capacity, thermal runaway, lithium iron phosphate pouch cell, debris characteristics, aerogenesis

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