Study of the interfacial mechanical degradation in all-solid-state lithium batteries (FWOSB68)

Lithium-ion batteries have become a key technology in our everyday lives, and great interest has grown during the past decade towards new materials and new configurations of the cells. Solid state lithium batteries (SSBs) allow having higher energy density without compromising power and capacity, while assuring high safety at variable temperatures and good cycle stability. However during the charge and discharge of these batteries, there are significant volume changes in the electrodes that produce stress and strain effects on the materials. These effects can make layers separate and cracks to form in the battery materials, which reduces the potentially improved performance of these batteries. Our goal is to investigate the causes of this effect and to develop a tool that allows to determine under which operation conditions can a SSB operate without suffering these undesirable effects. To do so, we aim to to create a physics-based model of a complete thin-film battery, which would use the mechanical properties of the electrode and electrolyte materials and information about the battery geometry, to simulate cycling of the batteries and predict local stress/strain failure as a function of the state of charge of the cell and the applied forces. The model follows a built-in approach in which the interface geometry
increases in complexity gradually, and it will be validated experimentally at each step of the model development.

Keywords:Lithium ion

Disciplines:Destructive and non-destructive testing of materials