软包三元锂离子电池热失控毒性产物分析及结构变化研究

Investigation of toxic products and structural changes in softpacked ternary lithium-ion batteries during thermal runaway

本研究旨在深入探究三元电池在热失控过程中产生的毒性产物,并分析电池结构变化对电学性能和安全性的影响。随着电动汽车市场的快速增长,三元电池因其高能量密度和较长的使用寿命而广受欢迎。然而,电池热失控作为电动汽车安全的重大隐患,已成为行业关注的焦点。本研究首先通过火焰触发三元电池的热失控反应,并对反应过程中产生的气体进行收集和分析。实验结果显示,随着荷电状态(state of charge,SOC)的升高,电池热失控也越发剧烈,一旦开始热失控,极易引起周围电池的连锁反应。同时热失控过程中会产生包括一氧化碳(CO)、氟化氢(HF)、丙烯醛、丙烯腈以及含有苯环的有毒有害气体。其中,一氧化碳和其他一些高毒性的化合物对人体健康构成严重威胁。在毒性产物分析的基础上,本研究进一步探讨了热失控过程中电池结构的变化。通过扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)等先进表征手段,对热失控前后的电池材料进行观察和分析。结果表明,热失控过程中,电池的正负极材料会发生明显的热解和氧化反应,产生大量的气体和高分子化合物,这些产物会进一步加剧电池的热失控,并导致电池结构的破坏。本研究不仅揭示了三元电池热失控过程中产生的毒性产物及其危害,还深入分析了热失控过程中电池结构的变化。这些研究成果不仅为电动汽车的安全评估提供了重要的数据支持,也为三元电池的改进和优化提供了有益的参考。

This study aims to investigate the toxic products generated during the thermal runaway of ternary lithium-ion batteries and examine the impact of structural changes on battery performance and safety.With the rapid growth of the electric vehicle market,ternary batteries have gained popularity due to their high energy density and extended service life.However,thermal runaway poses a significant safety risk for electric vehicles,making it a critical area of concern for the industry.In this research,we initiated the thermal runaway of ternary batteries using flame ignition and subsequently collected and analyzed the gases produced.Experimental results indicated that the severity of thermal runaway intensifies with an increase in the state of charge(SOC).Once thermal runaway occurs,it can easily trigger a chain reaction in nearby batteries.During this process,toxic gases including carbon monoxide(CO),hydrogen fluoride(HF),acrolein,acrylonitrile,and aromatic chemicals are emitted.Notably,carbon monoxide and several other toxic compounds pose severe health risks.Building upon the analysis of toxic emissions,this study further examined the structural changes occurring within the battery during thermal runaway.Advanced characterization techniques,including scanning electron microscopy(SEM),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS),were employed to observe and analyze battery materials before and after thermal runaway.The findings revealed that the cathode and anode materials undergo significant pyrolysis and oxidation,resulting in the generation of substantial quantities of gas and macromolecular compounds.These byproducts further accelerate the thermal runaway process and contribute to the structural degradation of the battery.This study not only elucidates the toxic emissions generated during the thermal runaway of ternary batteries and their associated hazards but also provides an in-depth analysis of the structural transformations within the battery.The findings offer crucial data for the safety evaluation of electric vehicles and serve as a valuable reference for the improvement and optimization of ternary lithium-ion batteries.