Understanding Ion Solvation Structure and Transport in Multicomponent Ionic Liquids

离子液体是一种液态盐混合物，具有良好的物理性能，如热稳定性和电化学稳定性、不可燃性和低挥发性，使其成为各种化学合成和储能应用中的理想溶剂、催化剂和电解质。为了使电动汽车得到更广泛的应用，目前的研究需要是在保证安全运行的同时，具备足够耐用性的高性能电池。本基础研究项目旨在引入一种控制旋钮，用于设计离子液体作为锂离子和锂金属电池电解质的性能。这种合理的设计方法可能会导致实现更安全的电池，其不可燃电解质可在超出传统电解质范围的温度下工作，并在所有其他电解质失效的极还原或氧化环境中工作。该项目将推动下一代储能设备的发展。作为该项目的一部分，“蒸汽能源”综合教育计划将通过视觉艺术的视角教授基本的物理现象，从而加强学生的科学和工程训练。通过与克利夫兰艺术学院的持续合作，视觉艺术模块将被整合到凯斯西储大学的课程中。教育和外展活动的预期结果是提高工科学生对STEM的兴趣和参与，提高他们的创造力和科学沟通技巧。本项目的目的是了解多组分离子液体中溶质离子的溶剂化结构和输运机制，其中存在三个或更多的离子。该研究将利用理论指导的实验方法，结合量子计算和拉曼光谱来解释复杂电解质中的离子配位和溶剂化结构。该结构如何影响输运性质和最终的系统级性能将通过锂离子转移测量和速率能力测试来研究。所获得的新知识将回答重要的基本问题，包括溶质离子浓度、溶剂化结构中的离子配位和多组分离子液体混合物中离子电导率之间的关系，以及离子液体的诱导、极性-非极性、纳米尺度非均质性在决定宏观电导率和溶质离子转移中的作用的表征和机制。这项研究将产生与下一代电化学储能系统相关的新型电解质和传输特性的基础。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。

Ionic liquids are liquid salt mixtures that have favorable physical properties such as thermal and electrochemical stability, non-flammability, and low volatility, which render them as ideal solvents, catalysts, and electrolytes in various chemical synthesis and energy storage applications. A current research need to enable wider adoption of electric cars, is high performance batteries with sufficient durability while retaining safe operations. This fundamental research project aims to introduce a control knob for the design of ionic liquids' properties as electrolytes for lithium ion and lithium metal batteries. This rational design approach may lead to the realization of safer batteries with nonflammable electrolytes operable at temperatures beyond the range of traditional electrolytes and within extremely reductive or oxidative environments where all other electrolytes fail. This project will advance the next generation of energy storage devices. As part of this project, the integrated education program 'STEAM for Energy' will enhance students' science and engineering training by teaching fundamental physical phenomena through a visual arts lens. The visual arts module will be integrated into the Case Western Reserve University curriculum through the investigators ongoing collaborations with the Cleveland Institute of Art. The expected outcomes from the educational and outreach activities are increased interest and broadened participation in STEM, and enhanced creativity and scientific communication skills for engineering students.The objective of this project is to understand the solvation structure and transport mechanism of solute ions in multicomponent ionic liquids, where ions of three or more are present. The research will utilize a theory-guided experimental approach that combines quantum calculations with Raman spectroscopy to interpret the ion coordination and solvation structure in the complex electrolytes. How the structure impacts transport properties and ultimately the system level performances will be investigated by lithium ion transference measurements and rate-capability tests. The new knowledge gained will answer important fundamental questions including the relationship among the solute ion concentration, ion coordination within the solvation structure, and the ion conductivity in multicomponent ionic liquid mixtures and the characterization and mechanism of the role of induced, polar-nonpolar, nanoscale heterogeneity of ionic liquids in determining the macroscopic conductivity and the solute ion transference. This research will produce new electrolytes and the underpinnings of the transport properties that are relevant to next generation electrochemical energy storage systems.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.