卤化物中锂离子传导的物理机制探究及优化设计

卤化物固态电解质材料有望同时兼顾离子传导、稳定性、电极兼容性等优点，但是目前所报道的卤化物最高室温离子电导率（~1mS／cm）仍无法与硫化物媲美。本项目将结合近年来所报道的提升锂离子电导率的设计思想，从固体中离子扩散物理出发，全面探究可提升指前因子D0和降低活化能垒Ea的影响因素，例如，阴离子超晶格结构、阴离子电荷、晶格体积、锂晶格振动性质、锂占据形式以及锂占据多面体畸变等，提出高效开发新型卤化物超离子导体的设计指导原则，厘清畸变氯化钠和纤锌矿结构卤化物的离子电导率高于尖晶石结构的根本原因，结合第一性原理高通量计算和实验获得具有高离子电导率、高热力学和电化学稳定性的卤化物锂离子超快导体材料。

Lithium halide compounds are promising solid electrolytes with good combinations of lithium ionic conductivity, stability and compatibility with electrodes. However, the reported highest room temperature conductivity of halides (~1mS/cm) still can not compete with sulfides. Based on the recently reported approach to enhance Lithium ionic conductivity as well as the ionic diffusion physics in solids, we will systematically investigate the critical factors to increase the prefactor D0 and decrease the activation energy Ea, e.g., the anion super lattice, the anion charge, lattice volume, Li vibration, Li coordination environment and distortions of polyhedrons. The eventual goal of this project is to provide important guidance to the halide solid electrolyte materials design and to understand the superior Li ionic conductivity in the halide electrolyte with distorted NaCl and wurtzite structure compared to that with spinel structure. The high-throughput first-principle calculations and experiment will be performed to develop the advanced halide superionic conductors with high ionic conductivity, high thermal and chemical stabilities.