锂离子电池性能退化与分层新表面生成的关联机理

目前在锂离子电池领域内大部分力学相关的工作都是到应力和损伤为止，而对力学损伤如何导致电化学性能改变的探索还相当匮乏。本项目拟针对锂离子电池中电极分层对电化学性能的影响展开研究。电极活性层-集流体的界面分层是电极的最主要和最普遍的破坏形式，并与电池电化学性能紧密相关。准确描述分层对电化学性能的影响，对于锂离子电池内在机理的理解，尤其是对力学在锂离子电池问题中重要角色的认识，均具有重要意义。本项目拟通过考虑分层引起的新表面生成以及其对电极电势和电流的影响机理，建立用于预测随分层演化的电化学性能的理论模型，给出不同关键参数对电池电化学行为的影响规律，提出可以提高电化学性能的优化材料和结构，并借助宏观和微观实验进行验证。

Currently, the most studies on mechanical problems in lithium-ion batteries (LIBs) focused on the stresses and mechanical damages. However, it still lacks understanding of the coupled mechanical-electrochemical failure in the LIBs. In this project, the effect of interfacial delamination on electrochemical performance in LIB electrodes will be focused. The interfacial delamination between active layer and current collector is the most common and important damage phenomenon in the electrodes, and is closely related to the electrochemical performance. Precise description of the relationship between delamination and electrochemical performance would have a great significance for understanding of internal mechanisms in the LIBs, and more importantly, the crucial role of mechanics in the LIBs. The applicant plans to investigate new surface formation induced by delamination, and then evaluate its impact on electrode potential and current. By considering the new mechanisms, a theoretical model will be built to predict evolution of the electrochemical performance caused by growth of the delamination. According to the impacts of key parameters, optimized materials and structures will be able to be proposed. Moreover, macro and micro experiments are designed to validate the theoretical predictions.