基于半解析法的固态电池粘弹性接触力学方法与界面力-电化学耦合机理研究

固态锂金属电池是兼顾电池安全性和能量需求的可行途径之一。但由于缺少有机溶液的浸润以及固体表面不可避免的粗糙度，锂金属与固态电解质界面的接触力学问题尤为突出，造成界面阻抗过大，致使界面电流集中现象，加剧锂枝晶的生长并穿透固体电解质造成电池短路。本项目将着眼于固态电池中锂金属电极与聚合物-陶瓷电解质界面，（1）构建基于半解析法和连续卷积-快速傅里叶变换技术的粘弹性接触力学数值模型，（2）提出基于多物理场接触建模研究力-电化学耦合规律的新方法，（3）发展结合力学和电化学耦合规律的界面稳定性设计思路，探索锂电池界面接触力学-电化学耦合作用机理。期望在粗糙表面粘弹性接触力学方法、锂电池层状结构接触力学模型等方面获得原创性成果，为提高固态电池使用稳定性和安全性提供理论支持和技术指南。

Solid-state lithium metal battery is one of the feasible ways to meet the safety and energy demand of batteries. However, due to the lack of infiltration of organic solution and the inevitable roughness of solid surface, the poor contact problem between lithium metal and solid electrolyte is particularly prominent, resulting in a too larger interface impedance, and an interface current concentration phenomenon, aggravating the growth of lithium dendrite and penetrating the solid electrolyte, and further resulting in short circuit. This project will focus on the interface of the Li anode and polymer-ceramics electrolyte, (1) propose a viscoelastic contact mechanics model based on the semi-analytical method and the continuous convolution-fast Fourier transform, (2) a multi-physical field based method to study the mechanical-electrochemical coupling behavior, and (3) a design method combining mechanical, mechanical and electrochemical coupling law to improve the interface stability of solid-state battery, to explore the interfacial mechanism in the aspects of lithium battery interface contact stability. We hope to obtain original results in the viscoelastic contact mechanics algorithms considering rough surfaces and the contact mechanics model of layered structures of lithium batteries, to provide theoretical support and technical guidance for the battery stability and safety of use.