Understanding the Stability and Reactivity of Radical Cations for Improved Overcharge Protection in Lithium-Ion Batteries

通过这项由化学系化学结构、动力学和机制-B计划资助的奖项，来自肯塔基大学的Susan A.Odon教授将致力于提高芳香分子自由基阳离子形式的稳定性，将其用作锂离子电池过充电保护的氧化还原穿梭电解液添加剂。将表征自由基阳离子在各种溶剂环境中的寿命，包括用作电池电解液的碳酸盐，以确定氧化时的分解产物。对这些产品的分析将确定(I)溶剂环境如何影响反应结果，(Ii)哪些特征会产生更稳定的自由基阳离子，以及(Iii)自由基阳离子持久性与锂离子电池在氧化还原穿梭分解之前的循环过充电保护次数之间是否存在相关性。这项研究的结果将为科学界和社会在开发新材料以改善储能材料，特别是锂离子电池的性能和安全性方面提供帮助。随着混合动力汽车的数量和对可再生能源储存需求的持续增长，拥有可靠的能源储存变得更加重要。需要提高锂离子电池安全性和寿命的电解液添加剂，以加快这项技术的发展，使其用于多种应用。这个项目将使不同层次的学生(高中生、本科生和研究生)接触到越来越重要的社会和实践领域的科学研究。

Through this award, funded by the Chemical Structure, Dynamics, and Mechanisms - B Program of the Division of Chemistry, Prof. Susan A. Odom from the University of Kentucky will seek to improve the stability of radical cation forms of aromatic molecules used as redox shuttle electrolyte additives for overcharge protection in lithium-ion batteries. The lifetimes of the radical cations in a variety of solvent environments, including carbonates used as battery electrolytes will be characterized to determine decomposition products upon oxidation. Analysis of these products will determine (i) how solvent environment affects the reaction outcome, (ii) what features results in more stable radical cations, and (iii) if there is a correlation in radical cation persistence vs. the number of cycles overcharge protection in a lithium-ion battery before redox shuttle decomposition. Higher oxidation potential shuttles for new cathode materials will be synthesized and methods to stabilize the resulting radical cations, by surrounding them in protective cages and extending electronic delocalization, will be explored.The results of this research project have potential to provide benefits to the scientific community and our society in the development of new materials for the improved performance and safety of energy storage materials, specifically lithium-ion batteries. As the number of hybrid electric vehicles and the need for storage of renewable energy sources continue to grow, it becomes more important to have reliable energy storage. Electrolyte additives that improve the safety and lifetimes of lithium-ion batteries are needed to expedite the growth of this technology for use in multiple applications. This project will expose students at different levels (high school, undergraduate, and graduate students) to scientific research, in a growing area of social and practical importance.