Effect of external pressure and internal stress on battery performance and lifespan

There are abundant electrochemical-mechanical coupled behaviors in lithium-ion battery (LIB) cells on the mesoscale or macroscale level, such as electrode delamination, pore closure, and gas formation. These behaviors are part of the reasons that the excellent performance of LIBs in the lab/material scale fail to transfer to the industrial scale. This paper aims to systematically review these behaviors by utilizing the ‘mechanical origins – structural changes – electrochemical changes – performance’ logic. We first introduce the mechanical origins i.e., the external pressure and internal deformation, based on the different stages of battery life cycle, i.e., manufacture and operation. The response of the batteries due to the two mechanical origins are determined by the mechanical constitutive relation of battery components. The resulting structural changes are ascribed to size and distribution of pores and particles of the battery components, and the contact states between different components. The electrochemical changes are divided into ionic/electrical impedance and lifespan. We have summarized massive experimental observations and modeling efforts and the influencing factors in each section. We also clarify the range of external pressure and internal deformation under which the proposed structural and electrochemical changes are likely to take effects. Lastly, we apply the logic to the next generation lithium metal-based solid-state battery. This review will provide useful guidelines to the design and manufacture of lithium-based rechargeable batteries and promote the development of the electric vehicle industry.