Disorder-induced enhancement of lithium-ion transport in solid-state electrolytes

Enhancing the ion conduction in solid electrolytes is critically importantfor the development of high-performance all-solid-state lithium-ion batteries(LIBs). Lithium thiophosphates are among the most promising solid electrolytes,as they exhibit superionic conductivity at room temperature. However, the lackof comprehensive understanding regarding their ion conduction mechanism,especially the effect of structural disorder on ionic conductivity, is along-standing problem that limits further innovations of all-solid-state LIBs.Here, we address this challenge by establishing and employing a deep learningpotential to simulate Li3PS4 electrolyte systems with varying levels ofdisorder. The results show that disorder-driven diffusion dynamicssignificantly enhances the room-temperature conductivity. We further establishbridges between dynamical characteristics, local structural features, andatomic rearrangements by applying a machine learning-based structurefingerprint termed "softness". This metric allows the classification of thedisorder-induced "soft" hopping lithium ions. Our findings offer insights intoion conduction mechanisms in complex disordered structures, therebycontributing to the development of superior solid-state electrolytes for LIBs.