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

通过这个奖项，由化学系的化学结构，动力学和机制- B计划资助，教授苏珊A。来自肯塔基州大学的Odom将寻求提高芳香分子的自由基阳离子形式的稳定性，这些芳香分子用作锂离子电池过充电保护的氧化还原穿梭电解质添加剂。自由基阳离子在各种溶剂环境中的寿命，包括用作电池电解质的碳酸盐，将被表征以确定氧化后的分解产物。对这些产物的分析将确定（i）溶剂环境如何影响反应结果，（ii）哪些特征导致更稳定的自由基阳离子，以及（iii）在氧化还原梭分解之前，自由基阳离子持久性与锂离子电池中的过充电保护循环次数是否存在相关性。将合成用于新型阴极材料的更高氧化电位梭，并探索通过将其包围在保护笼中并延长电子离域来稳定所产生的自由基阳离子的方法。该研究项目的结果有可能为科学界和我们的社会在开发新材料以改善储能材料的性能和安全性方面提供益处。特别是锂离子电池。 随着混合动力汽车的数量和对可再生能源存储的需求持续增长，可靠的能量存储变得更加重要。 需要提高锂离子电池安全性和寿命的电解质添加剂，以加快该技术在多种应用中的发展。该项目将使不同层次的学生（高中生，本科生和研究生）接触科学研究，在社会和实际重要性日益增长的领域。

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.