Unraveling Mechanisms of Strongly Correlated Dynamics in Ionic Systems

在这个由化学部化学结构动力学和机制- a （CSDM-A）项目资助的项目中，田纳西大学的Alexei Sokolov教授和Stephen Paddison教授将结合实验和计算研究，对浓离子系统中控制离子动力学相关性的机制有一个基本的理解。这些相关性强烈影响离子电导率，其机制仍然是一个谜。利用广泛的实验技术与高保真度模拟相结合，对可能增强或抑制液体和固体电解质电导率的不同离子-离子相关性的详细分子水平描述正在开发中。这些研究的结果可能会影响广泛的离子导电材料的基本原理，并将对各种电能存储技术的新型电解质的合理设计至关重要。参与该项目的学生和博士后将在复杂的实验和计算研究方面获得宝贵的经验。Sokolov研究小组还从事针对K-12学生的各种外展活动。本项目主要进行离子液体、聚合离子液体和有机离子塑料晶体中离子和电荷输运的协同实验和计算研究。实验涉及宽带介电光谱，中子散射和核磁共振将结合从头算和经典原子分子动力学（MD）模拟和电子结构计算。提出的研究可能会提供离子大小的作用，离子和反离子迁移率的差异，以及静电相互作用对离子相关性的全面认识。结果还将揭示特定的结构或成分，可以将离子-离子相关性从负（抑制电导率）调整为正（增强电导率）。本研究将有助于制定可用于固态电池、液流电池和其他电化学应用的新型电解质的设计标准，并为培养研究生和博士后研究人员提供良好的机会。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。

In this project funded by the Chemical Structure Dynamics and Mechanisms-A (CSDM-A) program of the Chemistry Division, Professors Alexei Sokolov and Stephen Paddison of the University of Tennessee will combine experimental and computational studies to develop a fundamental understanding of the mechanisms controlling correlations in ion dynamics in concentrated ionic systems. These correlations strongly influence ionic conductivity, and their mechanism remains a mystery. Using a broad array of experimental techniques combined with high fidelity simulations, a detailed molecular-level description of the distinct ion-ion correlations that may enhance or suppress conductivity in liquid and solid electrolytes is being developed. The results of these studies will likely impact the fundamentals of a wide range of ion conducting materials and will be important for rational design of novel electrolytes for various electrical energy storage technologies. The students and postdoc engaged in this project will gain valuable experience in sophisticated experimental and computational research. The Sokolov research group is also engaged in various outreach activities targeted at K-12 audiences.This project focuses on synergistic experimental and computational studies of ion and charge transport in ionic liquids, polymerized ionic liquids and organic ionic plastic crystals. Experiments involve Broadband Dielectric Spectroscopy, neutron scattering, and NMR will be combined with ab initio and classical atomistic molecular dynamics (MD) simulations and electronic structure calculations. The proposed study will likely provide a comprehensive knowledge of the role of ion size, disparity in the ion and counter-ion mobility, and electrostatic interactions on ionic correlations. The results will also reveal specific structure or compositions that may tune ion-ion correlations from negative (suppressing conductivity) to positive (enhancing conductivity). This study will help to develop design criteria for novel electrolytes that may be utilized in solid state batteries, flow batteries and other electrochemical applications, and provide good opportunities for the training of graduate students and postdoctoral researchers.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.