Computational Investigation of Dynamic Voltage Stability in Solid State Batteries

Intrinsic or interface thermodynamic voltage windows of solid electrolytes are often narrower than the operational voltage range needed by a full battery, thus various decomposition reactions can happen in a practical solid-state battery. These decompositions can undergo local volume expansions, which will compress the reaction front in a solid environment under a mechanical constriction and modify the reaction thermodynamics and kinetics. Experimentally, it was found that a proper battery design utilizing the effect can lead to dynamic voltage stability for advanced battery performance. Here we articulate first our state-of-the-art understanding about how computationally the dynamic voltage stability should be interpreted and treated. We further apply our constrained ensemble computational approach across these solid-state electrolytes to systematically evaluate and compare their dynamic stability voltage windows in response to the mechanical constriction effect. High throughput calculations are used to search for coating materials for different interfaces between sulfide, halide, and oxide electrolytes and typical cathode materials with enhanced dynamic voltage stability.