硫系玻璃离子电导性能的定量计算和预测及纳晶复合增强机理研究

高能电池和电致变色窗等电化学离子器件高安全、长寿命及绿色环保等方面的迫切需求，急需室温离子电导率高、安全性好和易于小型化等优点的固态电解质材料。硫系玻璃快离子导体材料作为一类重要的固态电解质材料，近年来一直是国际上的探索热点之一。目前，进一步提升该类材料离子传输性能的理论研究方面，亟需解决以下两个问题：1）离子传输性能定量计算和预测的方法欠缺；2）纳晶复合硫系材料离子电导纳米晶增强的微观机理尚不明晰。针对该现状，本项目拟首先以离子电导硫系玻璃为研究对象，利用"拓扑限制理论"探索离子电导性能定量计算和预测的方法；进而以纳米晶复合硫系玻璃为研究对象，通过界面区元素的组成、分布、化学配位环境以及离子传输特性的详细表征，结合第一性原理计算，阐明离子电导的纳米复合增强机理。本研究将深化玻璃及纳米复合材料中离子传输机理的认识，促进固态离子学的发展，对拥有自主知识产权固态离子功能器件的开发具有重要意义。

Considering the development trend of ion devices such as high energy battery and electrochromic windows toward high safety, long life and environment friendly, an urgent demand is very needed for inorganic solid electrolytes with the merits such as free of hazards of leakage, high reliability, long storage life and easy miniaturization. As an important kind of inorganic solid electrolyte, chalcogenide materials have consistently been a hot point of investigation. At present, to further enhance its ionic transporting property, the solution of the following two problems is necessitated: 1) Models of quantitative calculation and prediction of ionic conductivity are very scarce; 2) Enhancing mechanism of ionic conductivity due to nanocomposites compared with the base chalcogenide glasses is unclear. According to the state of the art in the field of ion conductive chalcogenide materials, this project will first probe the quantitative calculation and prediction of the macroscopic property of ion conduction of chalcogenide glasses based on the topological constraint theory of glasses. Furthermore, this project will focus on the phenomenon of "enhanced ionic conductivity of nanocomposites compared with the base glasses". Based on the detailed characterization of distribution and local environment of elements of interface regions together with the Li ion dynamics, combined with the first principles calculations, this project will clarify whether the observed enhancement of ionic conductivity is due to a higher defect concentration (thermodynamically controlled) or to smaller activation barriers for local hopping processes (kinetically controlled). This project will promote the deep insight into the ion transport mechanism among glasses and nanocomposites, boost the development of solid state ions, and enhance the strengths of our country in the field of solid state electrolytes.