Understanding the structure-response of Si-rich solid-state batteries under different stress fields

Solid-state batteries (SSBs) with silicon (Si) anodes offer improved safety and energy density but are significantly limited by structural changes during cycling. To maintain materials contact and structural integrity, biaxial compressive stress is usually applied to batteries formed in a cylindrical housing. The correlation between electrochemical performance, structural characteristics such as cracking patterns, and applied stress have been well established. Here, we introduce a novel funnel-shaped battery housing that induces an additional radial force, enabling a comprehensive investigation of multi-axial stress effects on battery structures. Leveraging X-ray microtomography, we will examine microstructural evolution in heterogeneous Si-rich SSBs beyond the biaxial stress framework. This research will be the first experimental study of Si SSBs under multi-axial stress, providing critical insights into structural responses and serving as a benchmark for improved battery design.