LLZO-PPC-Li固态锂离子电池层状结构关键界面力-电化学耦合行为实验研究

本项目拟对LLZO固态电解质-柔性PPC薄膜-锂负极（LLZO-PPC-Li）层状半电池结构在充放电过程中的界面力电化学耦合行为开展研究。设计和搭建在线太赫兹时域光谱/光学成像多物理参数协同实验表征系统，拟实现对LLZO-PPC-Li层状半电池结构进行多物理量的在线同步测量，表征电极的体积应变、应力、层状结构的界面阻抗、固态电解质的电导率以及半电池结构的多周期库伦效率衰减率等多种力学和电化学参数。通过PPC柔性过渡层和LLZO、Li金属的层间界面力学实验，分析其层间界面强度、损伤模式和损伤演化规律。建立PPC柔性过渡层的应变/应力传递模型，系统研究界面力学行为和界面锂离子传输的双向作用机制，进而揭示LLZO-PPC-Li结构的力学-电化学耦合失效机理，为未来深入研究全固态锂离子电池提供实验支持和技术储备。

The project aims to investigate the mechanical-/electrochemical coupling behavior of interfaces in LLZO solid electrolyte-compliant PPC thin film-Li metal anode laminate structures. THz-TDS system coupled with DIC imaging system is planned to be established to realize in operando measurements for multi-physical parameters of the LLZO-PPC-Li specimen, including the volumetric strain and the stress of Li metal, the interface impedance, the conductivity of the LLZO solid electrolyte as well as the coulombic efficiency during the lithiation/delithiation procedures.Through interfacial experiments between the three layers, the interfacial strength, the damage mode and the damage evolution can be analyzed.The strain/stress transfer model of the PPC compliant thin film is to be established to systematically investigate the coupling behavior between the interfacial mechanics and the Li ion transmission, revealing the failure mechanism of the LLZO-PPC-Li structure.