COMBUSTION CHEMISTRY OF LI-ION BATTERY ELECTROLYTES, THEIR PYROLYSIS PRODUCTS, AND POSSIBLE FIRE SUPPRESSANTS FOR ELECTRIC VEHICLE SAFETY

锂离子电池在全球范围内被用于为越来越多的移动设备提供动力，并将在未来几十年在交通运输行业发挥重要作用。电动汽车的发展具有重要的战略意义，因为为这些汽车提供动力的电力可以来自可再生能源（太阳能、风能、生物燃料）、无碳能源（核能）和大型集中式工厂的化石燃料，从而实现更高的效率、更好的排放控制和碳捕获。然而，这些电池的电池单元中含有易燃的电解液，如果它们受到损坏，例如在电动汽车的碰撞中或在它们的概念中存在缺陷的情况下，它们就会构成安全隐患。在过去的几年里，已经报道了许多与电动汽车有关的火灾事件。由于锂离子电池在我们的生活中变得如此重要，与它们的使用相关的火灾安全隐患也随着它们的尺寸和无处不在而增加。该项目旨在通过添加特定的灭火剂来降低电解质的可燃性，这是一个化学水平上的基本方法从未被遵循的领域。在拟议的项目中，锂离子电池电解质中的典型成分和电池热失控时喷出的典型气体混合物的燃烧特性将进行实验研究。这些燃烧特性将使用精确的化学动力学标记来测量，这些化学动力学标记来自定义良好的实验技术和光学诊断，如激光吸收光谱法。锂离子电池电解液中的许多成分将首次被研究。同样，将研究特定灭火剂的高温化学性质，并对其灭火潜力进行实验研究。在本研究过程中获得的实验结果将用于开发或完善电解质成分和灭火剂的详细化学动力学机制。该项目的成功完成将大大提高对lib可燃性的预测能力，并有可能在不降低其性能的情况下降低其可燃性。在这项研究的基础上，锂离子电池在许多行业的更安全使用可能会得到体验。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Lithium-ion batteries are globally used to power the ever-growing number of mobile devices and will play a significant role in the transportation industry for decades to come. The movement toward electric mobility is of strategic importance, as the electricity used to power these vehicles can be produced from a large blend of renewable (solar, wind, biofuels), carbon-free (nuclear) energies, and from fossil fuels within large centralized plants, allowing for higher efficiency, better emissions control, and carbon capture. However, these batteries contain a flammable electrolyte in their battery cells which makes them a safety hazard if they are damaged, such as during a collision of an electric vehicle or in case of default in their conception. Many fire incidents related to electric vehicles have been reported over the past few years. Since Lithium-ion batteries are becoming so important in our lives, the fire safety hazard associated with their usage is also increasing with their size and ubiquity. This project aims at reducing the flammability of the electrolyte by adding specific fire suppressants, an area where a fundamental approach at the chemistry level has never been followed. In the proposed project, the combustion properties of the typical components found in Lithium-ion battery electrolytes and of a mixture of the typical gases ejected during a battery thermal runaway will be investigated experimentally. These combustion properties will be measured using accurate chemical kinetics markers obtained from well-defined experimental techniques and optical diagnostics such as laser absorption spectrometry. Many of these components from the lithium-ion battery electrolyte will be studied for the first time. Similarly, the high-temperature chemistry of specific fire suppressant agents will be investigated, and their fire-suppressing potential will be investigated experimentally as well. The experimental results obtained during the course of this study will be used to develop or refine detailed chemical kinetics mechanisms for the electrolyte components and for the fire suppressants. The successful completion of the project will greatly advance the predictive capabilities on the flammability of LiBs and will potentially allow for reducing their flammability without reducing their performance. A safer use of lithium-ion batteries in many industries could be experienced based on the proposed research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.