固态锂基电池是解决锂电池能量密度低和安全性能差等问题的最佳途径之一，而锂离子导体低的电导率是阻碍其实用化的关键问题。本项目以Li-Ge-P-S硫化物固体电解质为研究对象，通过热处理过程中非晶粉体的玻璃化与晶化作用，辅助以复合少量异极性氧化物形成复合电解质的方法，调控硫化物固体电解质离子迁移的空隙或通道的大小，弱化骨架与迁移离子间的作用力，形成有利于离子输运的通道，降低多晶材料的晶界电阻，使晶界效应得到抑制，提高其离子晶界电导率。考察各种实验参数对硫化物固体电解质晶界电导的影响，分析材料的微观结构特征、晶界结构特性、复合电解质效应及温度与材料晶界离子电导之间的关系，获取锂离子导体中与晶界离子迁移动力学相关的信息，阐明硫化物固体电解质晶界调控与离子导电性能之间的内在联系，揭示其提高导电性能的机理与导电机制，为多晶固体电解质材料的设计、制备、改性及其在新型锂电池中的应用提供实验基础与科学依据。

All solid state Li-based batteries are the next generation batteries with much higher energy density and safty. However, the low ionic conductivity of the electrolyte limits their pratical application. In this project, the Li-Ge-P-S system will be investigated in order to prepare new type solid state electrolytes with high ionic conductivities at room temperature. The disadvantage of grain boundaries in polycrystalline materials will be suppressed by regulation of vitrification and crystallization effect during the heat-treatment of amorphous precursors. At the same time, the composite electrolyte of the sulfide matrix with oxide ceramics will be adopted to decrease the grain boundary resistance. The experiment parameters will be strictly adjusted and optimized. The dependence of ionic conductivity in grain boundaries on microstructure, grain boundary effect, composite electrolytes and temperature will be studied in detail. And the relationship between grain boundary control and ionic conductivity will be investigated. Also the mechanism on the modification of Li-ion conducting materials and the conduction mechanism of the obtained sulfide solid state electrolyte will be revealed. The achievement in this project will provide theory and practice basis for the design, preparation, modification and application of new type solid state electrolyte materials.