储能科学与技术 ›› 2025, Vol. 14 ›› Issue (5): 1797-1805.doi: 10.19799/j.cnki.2095-4239.2024.1061

• 储能材料与器件 • 上一篇    下一篇

磷酸铁锂电池存储失效机理及热安全性研究

汪红辉1,3(), 李嘉鑫1,3, 储德韧1,2,3(), 李彦仪1,3, 许铤2,3   

  1. 1.上海化工研究院有限公司
    2.上海化工院检测有限公司
    3.工信部工业(电池)产品质量控制和技术评价上海实验室，上海 200062
  • 收稿日期:2024-11-12 修回日期:2024-12-02 出版日期:2025-05-28 发布日期:2025-05-21
  • 通讯作者: 储德韧 E-mail:whh@ghs.cn;cdr@ghs.cn
  • 作者简介:汪红辉（1992—），男，博士，高级工程师，从事电池失效分析、安全检测及法规标准制修订等，E-mail：whh@ghs.cn；
  • 基金资助:
    上海市技术标准项目“动力锂电池运输安全技术规范”(23DZ2200800)

Study on the electrochemical performance failure mechanisms and thermal safety of lithium iron phosphate battery during storage conditions

Honghui WANG1,3(), Jiaxin LI1,3, Deren CHU1,2,3(), Yanyi LI1,3, Ting XU2,3   

  1. 1.Shanghai Research Institute of Chemical Industry Co. , Ltd.
    2.Shanghai Research Institute Chemical Industry Testing Co. , Ltd.
    3.Shanghai Laboratory for Quality Control and Technical Evaluation of Industrial Products (Battery), Ministry of Industry and Information Technology, Shanghai 200062, China
  • Received:2024-11-12 Revised:2024-12-02 Online:2025-05-28 Published:2025-05-21
  • Contact: Deren CHU E-mail:whh@ghs.cn;cdr@ghs.cn

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摘要：

磷酸铁锂电池因长循环周期稳定性、高安全性和低成本等优点在能源存储领域具有广泛应用，是当下主流的电化学储能器件之一，然而目前关于其存储过程性能失效和安全性研究并不充分。本文以某商用圆柱形磷酸铁锂电池为典型储能对象，通过存储模拟实验，借助多种无损分析技术和绝热加速量热仪，探究在不同环境温度(室温~72 ℃)和多种荷电状态(SOC = 0~100%)下磷酸铁锂电池的电化学性能及热安全性演化规律及深层次机理。实验结果表明，磷酸铁锂电池在存储过程中健康状态(SOH)及热失控特征受环境温度和荷电状态影响显著，温度为72 ℃且SOC为100%时，电池容量衰减速率是室温下的22.1倍，是SOC为0时的5.6倍，温度或荷电状态越高，电池容量衰减越严重，这主要是由于内部活性锂损失LLI和负极活性材料损失LAMNE所导致的。然而经过存储后磷酸铁锂电池的热安全性反而有所改善，这可能与内部活性材料损失导致电池内部体系能量下降有关。此外，借助容量增量技术，基于IC曲线特征峰强构建了电池容量衰减半经验预测模型。本研究为磷酸铁锂电池在未来大规模储能应用中的运行维护和安全防护提供了技术指导。

关键词: 磷酸铁锂电池, 存储失效, 荷电状态(SOC), 活性锂损失, 热安全性

Abstract:

Lithium iron phosphate batteries have gained widespread application in energy storage owing to their long cycle life, high safety, and low cost, making them one of the mainstream electrochemical energy storage devices. However, research on the performance degradation and safety of LFP batteries during stationary storage remains limited and is not sufficiently comprehensive. This study focuses on commercial cylindrical LFP batteries, investigating the evolution of electrochemical performance and failure mechanisms under varying temperature gradients (from room temperature to 72 ℃ and different states of charge (SOCs ranging from 0 to 100%). A series of composite storage simulation experiments were conducted, employing various nondestructive analysis techniques and adiabatic acceleration calorimeters (ARCs). The experimental results have shown that the state of health (SOH) and thermal runaway characteristics of LFP batteries during storage are significantly affected by temperature and SOC. The capacity attenuation rate of LFP battery with 100% SOC at 72 ℃ is 22.1 times that at room temperature and 5.6 times that with 0 SOC. Higher temperatures and higher SOC levels accelerate capacity fading, mainly owing to the loss of active lithium ions and active materials within the battery. Conversely, the thermal safety of LFP batteries during storage has been improved, which may be attributed to the reduced energy within the battery system caused by the depletion of active materials. Finally, a semi-empirical prediction model of LFP battery capacity decay is constructed based on the characteristic peak strength using the incremental capacity (IC) method. This study provides valuable technical guidance for the operation, maintenance, and safety measures required for LFP batteries in future large-scale energy storage applications.

Key words: LFP battery, storage failure, state of charge (SOC), LLI, thermal safety

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