Theory and Modeling of Specific Ion Solvation in Water and Non-Aqueous Solvents with Applications to Energy Storage

辛辛那提大学的托马斯贝克得到化学系化学理论、模型和计算方法项目的支持，对水和非水溶剂中的特定离子或霍夫迈斯特效应进行理论和计算研究。一系列的理论工具，包括自由能分区方法，如准化学理论和局部分子场理论，正在探索特定的离子溶剂化在复杂的环境中。解决了三个一般性问题：1）在量子力学水平上计算离子水合自由能2）通过自由能分配详细分析水亲和力匹配定律3）非水溶剂中离子溶剂化的基础研究，如碳酸亚乙酯和碳酸亚丙酯，并应用于锂离子电池和超级电容器的能量存储。 经典和高级量子方法都用于将相互作用划分为局部和远场分量，特别关注电荷重排和对相互作用能量的各种贡献（静电，感应，色散和电荷转移）。贝克和他的研究小组使用详细的计算模型来理解溶液中离子的特定行为。离子性质的微小变化，如大小或极化率，会对行为产生重大影响。 对特定离子溶剂化现象的透彻理解在溶液相化学、生物物理学和可持续能源储存等一系列领域具有广泛的影响。此外，从这些重要领域的广泛的例子都包括在核心本科生和研究生课程和针对计算化学家的专题课程。PI积极参与俄亥俄州拉尔夫·雷古拉计算科学学院新课程的开发，并在其顶峰研究项目期间指导代表性不足的本科生。正在开发一个新的关于化学促进可持续能源的概述课程（针对广泛的化学、物理和工程专业学生），以及一套网上提供的主动学习模块，以促进对基本物理化学原理的理解。

Thomas Beck of the University of Cincinnati is supported by the Chemical Theory, Models and Computational Methods program in the Chemistry Division to carry out theoretical and computational studies of specific ion or Hofmeister effects in water and non-aqueous solvents. A range of theoretical tools, including free energy partitioning methods such as the quasichemical theory and the local molecular field theory, is being employed to explore specific ion solvation in complex environments. Three general problems are addressed: 1) computation of ion hydration free energies at the quantum mechanical level 2) detailed analysis of the Law of Matching Water Affinities by free energy partitioning and 3) fundamental studies of ion solvation in non-aqueous solvents such as ethylene carbonate and propylene carbonate with application to energy storage in lithium-ion batteries and supercapacitors. Both classical and high-level quantum methods are utilized in partitioning the interactions into local and far-field components, with a particular focus on charge rearrangements and the various contributions to the interaction energies (electrostatics, induction, dispersion, and charge transfer). Beck and his research group use detailed computational modeling to understand the specfic behavior of ions in solution. Minor changes in the properties of an ion such as size or polarizability can have major effects on behavior. A thorough understanding of specific ion solvation phenomena has broad impacts in a range of fields including solution phase chemistry, biophysics, and sustainable energy storage. In addition, extensive examples from these important areas are included in both core undergraduate and graduate courses and special topics courses aimed at computational chemists. The PI is active in the development of a new curriculum for the Ralph Regula School of Computational Science in Ohio, and in mentoring under-represented undergraduates during their capstone research projects. A new overview course on Chemistry for Sustainable Energy is under development (aimed at a broad range of chemistry, physics, and engineering students), as well as a web-available set of active-learning modules for stimulating understanding of basic physical chemical principles.