Pressure-Driven Thermo-Electrochemical Interaction and Safety in Solid-State Batteries

Solid-state batteries (SSBs) can potentially offer superior energy density and power densities compared to conventional lithium-ion batteries. However, their performance is significantly hindered by poor solid-solid contact, which leads to sluggish ion transport and reaction kinetics. Ensuring sufficient particle contact through optimal stack pressure is crucial for mitigating these limitations, yet it remains a key challenge for large-scale SSB deployment. This work investigates the impact of stack pressure on the thermo-electrochemical interactions and safety of solid-state cathodes using different sulfide-based solid electrolytes. Our framework examines the intricate balance between transport and kinetics at both particle and electrode length scales, analyzing the trade-off between capacity and thermal safety. By systematically evaluating how pressure-driven interactions influences transport, interfacial resistance, and heat generation, we provide critical insights into mechanistic factors affecting the thermo-electrochemical response and thermal stability of solid-state cells. The findings from this study will aid in developing design strategies to enhance the thermal safety and resilience of SSBs. By addressing the underpinning performance-safety tradeoffs, this work contributes to advancing the practical implementation of high-energy-density SSBs.