Theory of energy landscapes and ion transport in amorphous materials

非晶材料中的离子输运在许多应用中具有重要意义。特别地，玻璃态电解质由于其化学组成的高度灵活性而可以被定制以满足特定需求。它们在电池、智能窗、超级电容器、光波导、传感器等领域有应用。该研究项目旨在开发理论方法，以构建玻璃材料中离子运动的能量景观，并基于该景观构建预测离子传输特性，如电导率及其活化能。对于景观建设，化学和结构信息相互联系的单位是用来形成主机网络的离子运动。理论发展的可靠性将对照实验观察加以检验。这些是，特别是，从一种新的技术获得的电荷附着诱导的离子传输，相关函数和核磁共振（NMR）测量的光谱密度，以及从魔角自旋NMR和原子探针断层扫描获得的局部组合物和结构配置的结果的扩散配置文件。具体目标是建模的浓度的化学单位建设的玻璃状网络，空间电荷分布来自这些浓度，和计算的离子传输量的动力学蒙特卡罗和分子动力学模拟。基于渗流和有效介质理论的分析计算补充了模拟。这包括分析离子动力学如何受到移动的离子之间的库仑相互作用和玻璃中空离子位点的浓度的影响。

Ion transport in amorphous materials is of vital interest for many applications. In particular glassy electrolytes can be tailored to specific needs because of a high flexibility in their chemical compositions. They find applications in batteries, smart windows, super-capacitors, optical wave guides, sensors, and others. This research project aims at developing theoretical methods to construct energy landscapes for the ionic motion in glassy materials and to predict ionic transport properties such as conductivities and their activation energies based on this landscape construction. For the landscape construction, chemical and structural information about mutually linked units is used that are forming the host network for the ionic motion. The reliability of the theoretical developments will be checked against experimental observations. These are, in particular, diffusion profiles obtained from a novel technique of charge attachment induced ion transport, correlation functions and spectral densities measured by nuclear magnetic resonance (NMR), as well as results for local compositions and structural configurations obtained from magic angle spinning NMR and atom probe tomography. Specific objectives are the modelling of concentrations of chemical units building the glassy network, of spatial charge distributions derived from these concentrations, and calculations of ionic transport quantities by means of kinetic Monte Carlo and molecular dynamics simulations. The simulations are complemented by analytical calculations based on percolation and effective medium theories. This includes analyses on how the ion dynamics are affected by the Coulomb interaction between mobile ions and by the concentration of empty ion sites in a glass.