摘要
荷电状态(SOC)作为锂电池运输安全的重要指标之一,研究其对锂电池热失控行为的影响至关重要。采用加速量热仪(ARC)对不同SOC的商用18650三元锂电池进行热失控研究。通过对电池热失控过程进行阶段划分,分别研究了其动力学行为。采用X射线衍射技术(XRD)分析了热失控前后电池正极材料的结构演变。结果表明,当电池SOC≥30%的情况下都存在发生热失控的风险。随着SOC的增加,电池在热失控前的绝热温升段时间间隔逐渐减小;同时在热失控阶段前期,电池内部反应的表观活化能随着SOC的增加而减小,说明高SOC电池热安全性明显降低。XRD分析结果表明,SOC≥30%的锂电池在热失控过程中其正极材料都发生了显著分解。通过分析锂电池热失控链式反应及其与SOC的关系,表明限制锂电池的荷电状态(SOC)对于抑制其潜在的热失控风险非常关键,也是保障其运输安全的有效手段之一。
State of charge(SOC)is one of the important parameters for the safety transportation of lithium batteries,thus the study of the influence of SOCs on the thermal runaway behavior of lithium batteries is very meaningful.The accelerating rate calorimeter(ARC)was utilized to study thermal runaway behaviors of the commercial 18650 NCM lithium batteries with different SOCs.The thermal runaway processes were divided into different stages and their related chemical kinetics were studied respectively.The structural evolution of the cathode materials during the thermal runaway were analyzed by X-ray diffraction(XRD)analysis.The related results show that there exist risks of thermal runaway in all batteries with SOC≥30%.With the increase of batteries’SOCs,the adiabatic temperature rising time interval before the thermal runaway of batteries decrease gradually;also the apparent activation energies of internal reactions decrease with the increase of SOCs,all indicating that the batteries’thermal safety are significantly reduced.The XRD analysis show that the cathode materials of SOC≥30%batteries are significantly decomposed during their thermal runaway.Finally,the thermal runaway chain reactions with the influence of SOCs of batteries were discussed,indicating that to limit the SOC of lithium batteries is very important for inhibiting their potential risks of thermal runaway,thus also for ensuring their transportation safety.
作者
孙建丹
汪红辉
储德韧
许铤
商照聪
SUN Jiandan;WANG Honghui;CHU Deren;XU Ting;SHANG Zhaocong(Shanghai Research Institute of Chemical Industry Co.,Ltd.,Shanghai 200062,China;Quality and Technology Evaluation Laboratory(Battery),Ministry of Industry and Information Technology,Shanghai 200062,China;Shanghai Research Institute Chemical Industry Testing Co.,Ltd.,Shanghai 200062,China)
出处
《电源技术》
CAS
北大核心
2023年第8期1040-1045,共6页
Chinese Journal of Power Sources
基金
上海市科委(20DZ2290500,2021SN02)
上海市国资委(2021012)。
关键词
锂电池
热失控
荷电状态
化学动力学
电池安全
正极材料
lithium battery
thermal runaway
state of charge(SOC)
chemical kinetics
battery safety
cathode materials
