储能科学与技术 ›› 2024, Vol. 13 ›› Issue (11): 4133-4142.doi: 10.19799/j.cnki.2095-4239.2024.0447

• 储能测试与评价 • 上一篇    下一篇

受限空间NCM811锂离子电池热失控蔓延及痕迹特征研究

韩登超(), 裴苑翔, 刘朝阳, 刘松涛, 王淮斌(), 孙均利, 王永路, 韩彧   

  1. 中国人民警察大学,河北 廊坊 065000
  • 收稿日期:2024-05-22 修回日期:2024-05-30 出版日期:2024-11-28 发布日期:2024-11-27
  • 通讯作者: 王淮斌 E-mail:1301388091@qq.com;wanghuaibin@cppu.edu.cn
  • 作者简介:韩登超(1998—),男,硕士研究生,研究方向为锂离子电池热失控及事故调查,E-mail:1301388091@qq.com
  • 基金资助:
    国家自然科学基金(52106284);博士科研创新计划课题(BSKY202302)

Thermal runaway propagation characteristics and residue analysis of NCM811 lithium-ion batteries in confined spaces

Dengchao HAN(), Yuanxiang PEI, Zhaoyang LIU, Songtao LIU, Huaibin WANG(), Junli SUN, Yonglu WANG, Yu HAN   

  1. China People's Police University, Langfang 065000, Hebei, China
  • Received:2024-05-22 Revised:2024-05-30 Online:2024-11-28 Published:2024-11-27
  • Contact: Huaibin WANG E-mail:1301388091@qq.com;wanghuaibin@cppu.edu.cn

摘要:

随着人们对电动汽车续航里程要求的不断提高,Li(Ni x Co y Mn1-x-y )O2(NCM)电池包内电池单体正极材料不断由低镍Li(Ni x Co y Mn1-x-y )O2(NCM111)向Li(Ni x Co y Mn1-x-y )O2(NCM811)高镍转变。本文以51 Ah的NCM811锂离子电池为研究对象,研究其在受限空间内的热蔓延行为、形变特征以及失控前后痕迹特征。结果表明,100%荷电状态(SOC)的NCM811电池模组在受限空间内发生热失控时,全部电池单体均喷发大量红色高温颗粒物,但仅有触发电池失控时出现射流火喷射特征,结果表明受限空间能够抑制电池模组热失控过程中火焰的产生,但是并不能阻止锂离子电池模组的热蔓延行为。100%SOC NCM811电池热失控时的前后表面温度介于820~979 ℃;热失控蔓延时间介于52~106 s;质量损失介于390~462 g;质量损失百分比介于45.58%~52.73%;电池正极材料颗粒热失控后出现明显的团聚现象,颗粒表面出现大量孔洞,正极材料表面O元素含量占比由39.96%减小至32.15%。本文研究内容可为高镍三元锂离子电池模组安全优化设计、热失控蔓延抑制及高镍电池热失控事故调查提供理论依据。

关键词: 锂离子电池, 受限空间, 热失控, 热失控蔓延, 事故调查, 安全性

Abstract:

With the increasing demand for longer ranges in electric vehicles, the cathode materials of Li(Ni x Co y Mn1-x-y )O2 (NCM) cells are shifting from low-nickel (NCM111) to high-nickel (NCM811) compositions. This study investigates the thermal runaway propagation behavior, deformation characteristics, and residue analysis of 51 Ah NCM811 lithium-ion batteries in confined spaces. Results show that during thermal runaway in confined spaces, all cells in the NCM811 battery module expelled a significant amount of red high-temperature particles, although only the triggered cell exhibited a pronounced jet fire. While confined spaces can suppress flame formation during thermal runaway, they cannot prevent the propagation of thermal runaway within the battery module. The front and back surface temperatures of NCM811 cells at 100% state of charge during thermal runaway ranged between 820 ℃ and 979 ℃, with propagation times ranging from 52 to 106 seconds. The mass loss ranged between 390—462 g, corresponding to a mass loss percentage of 45.58%—52.73%. Post-thermal runaway analysis revealed significant agglomeration of cathode material particles, with numerous holes observed on the particle surfaces. The oxygen content in the cathode material decreased from 39.96% to 32.15% after thermal runaway, confirming oxygen release during the event. This study provides a theoretical basis for the safe and optimal design of high-nickel NCM lithium-ion battery modules, the suppression of thermal runaway propagation, and insights into thermal runaway accident investigations of high-nickel batteries.

Key words: lithium-ion battery, thermal runaway, confined space, thermal runaway propagation, accident investigation, safety

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