Bis(2,2,2-trifluoroethyl) Carbonate As a Fire Suppressant Candidate for Lithium-Ion Batteries

Bis(2,2,2-trifluoroethyl) carbonate (BtFEC) is a fire
suppressant
candidate for the use of lithium-ion batteries (LIBs). It is known
that the electrolyte components in LIBs are highly flammable, making
them susceptible to igniting, whether this is due to a manufacturing
fault or an abuse of the LIB itself. To address this risk, the efficiency
of BtFEC as a fire suppressant was investigated experimentally in
a high-temperature combustion environment, allowing for further refinement
and validation of the model. Using a shock tube, BtFEC combustion
properties were measured experimentally behind a reflected shock wave,
capturing OH* chemiluminescence to assess ignition delay times (IDT)
as well as CO time-history profiles through the implementation of
laser absorption spectroscopy. Both pyrolysis and oxidation conditions
were captured with three equivalence ratios (ϕ = 0.5, 1.0, and
1.5) for a temperature range of ∼1200–1650 K at near-atmospheric
pressures. In addition, key species measurements were taken using
a microflow reactor (MFR) with a controlled temperature profile associated
with Fourier transform infrared spectroscopy (FTIR). Key species investigated
were BtFEC, CO, CO2, CHF3, CF2O,
C2F6, and HF for the temperatures range of 800–1300
K. MFR measurements allowed for a new set of measurements by which
to validate the model compared to the previous study [Mathieu et al. Proc. Combust. Inst. 2023, 39, 499] where the first assembly of the model used CO time-history,
IDT, and laminar flame speed measurements. Refinement of the model
was carried out with new high-level calculations as well as sensitivity,
rate-of-production, and reaction pathway analyses using recent reaction
rate updates from the literature. The modifications led to improvements
in the level of agreement between the kinetic modeling and the new
experimental data.

碳酸二(2,2,2-三氟乙基)酯(Bis(2,2,2-trifluoroethyl) carbonate, BtFEC)是一种可用于锂离子电池（lithium-ion batteries, LIBs）的阻燃候选组分。众所周知，锂离子电池的电解液组分具有极高可燃性，无论因制造缺陷还是电池自身滥用，均易引发起火。为应对该安全风险，本研究在高温燃烧环境下对BtFEC的阻燃效率开展了实验研究，以期为相关模型的进一步优化与验证提供支撑。本研究借助激波管（shock tube），在反射激波（reflected shock wave）后区域对BtFEC的燃烧特性开展实验测量：通过捕捉OH*化学发光（OH* chemiluminescence）信号以评估点火延迟时间（ignition delay times, IDT），并结合激光吸收光谱法（laser absorption spectroscopy）获取CO的时间历程曲线。实验覆盖了热解与氧化两种工况，当量比（equivalence ratio, ϕ）分别为0.5、1.0和1.5，测试温度范围约为1200~1650 K，压力接近常压。此外，本研究采用带有可控温度剖面的微流反应器（microflow reactor, MFR）结合傅里叶变换红外光谱（Fourier transform infrared spectroscopy, FTIR），对关键组分进行了测量。本次测试的关键组分包括BtFEC、CO、CO₂、CHF₃、CF₂O、C₂F₆及HF，测试温度范围为800~1300 K。相较于此前Mathieu等人发表于《Proceedings of the Combustion Institute》2023年第39卷第499页的研究——该研究首次构建模型时采用了CO时间历程、点火延迟时间及层流火焰速度（laminar flame speed）作为验证数据，本次微流反应器实验提供了全新的测量数据集，可用于该模型的验证与优化。本研究结合最新文献中更新的反应速率参数，通过高精度计算、敏感性分析（sensitivity analysis）、产率速率分析（rate-of-production analysis）及反应路径分析（reaction pathway analysis），对原模型进行了优化。本次模型优化后，动力学模型（kinetic modeling）结果与新实验数据之间的吻合度得到了显著提升。