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来为数量不断增长的移动设备提供动力，并将在未来几十年内在交通行业发挥重要作用。电动汽车的发展具有重要的战略意义，因为用于驱动这些车辆的电力可以从可再生能源(太阳能、风能、生物燃料)、无碳(核能)以及大型集中式工厂内的化石燃料的大量混合中产生，从而实现更高的效率、更好的排放控制和碳捕获。然而，这些电池在其电池单元中含有易燃电解液，如果它们被损坏，例如在电动汽车碰撞期间或在其构思出现故障的情况下，这将使它们成为安全隐患。在过去的几年里，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，与使用它们相关的火灾安全风险也随着它们的大小和普遍存在而增加。该项目旨在通过添加特定的灭火剂来降低电解液的易燃性，这是一个从未在化学层面上采用基本方法的领域。在拟议的项目中，将对锂离子电池电解液中的典型组分以及电池热失控期间喷出的典型气体的混合物的燃烧特性进行实验研究。这些燃烧特性将使用精确的化学动力学标记来测量，这些标记来自定义明确的实验技术和光学诊断，如激光吸收光谱。其中许多来自锂离子电池电解液的成分将是首次研究。同样，还将对特定灭火剂的高温化学进行研究，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改进电解液组分和灭火剂的详细化学动力学机理。该项目的成功完成将极大地提高对LIBS易燃性的预测能力，并可能在不降低其性能的情况下降低其易燃性。基于拟议的研究，许多行业可能会体验到更安全地使用锂离子电池。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.