Multiphysics modeling of the influence of initial pressure on mechanical and electrochemical performance of all-solid-state batteries

Abstract

All -solid-state batteries (ASSBs) are emerging as promising energy storage solutions owing to their enhanced safety and high energy density. However, the application of higher pressures is also required to improve electrochemical performance. This study employs a multiphysics approach by combining the discrete element method (DEM) and finite element method (FEM) to investigate the impact of the compression rate and initial pressure on electrochemical performance. To the best of the authors' knowledge, this is the first study to integrate the DEM and FEM methodologies for the prediction of electrochemical and mechanical responses, capitalizing on the advantages of both approaches. The DEM is used to investigate the compaction behaviors of solid electrolyte and electrode mixtures, yielding essential data on mechanical properties, which are subsequently incorporated into the FEM model. The FEM is utilized to systematically explore the electrochemical performance and mechanical responses. The findings highlight that elevated stress enhances geometric properties, including surface area and volume fraction, leading to improved electronic and ionic conductivity. Although higher compression ratios can enhance electrochemical performance, they also elevate stress levels, thereby increasing the potential for mechanical failure. Therefore, a well-balanced electrode design is crucial. This study provides valuable insights into the design of ASSBs.