Ionic conduction mechanism and design of amorphous Li_(2)O-TaCl_(5) solid electrolytesOA

Amorphous oxyhalides have emerged as promising solid-state electrolytes(SSEs)owing to their structural flexibility and high ionic conductivity.However,the origins of fast Li^(+)transport in these disordered structures remain unclear.Here,atomistic simulations reveal the microscopic mechanisms governing Li^(+)diffusion in amorphous xLi_(2)O–TaCl_(5) electrolytes.We identified two synergistic structural factors that control ion transport:(i)a stable,interconnected oxygen-bridged framework of Ta polyhedra,which forms continuous diffusion pathways;and(ii)reduced Li–Cl coordination,which alleviates local confinement.Together,these features enhance the connectivity of the Li^(+)diffusion pathways and promote correlated Li^(+)migration.To validate and further amplify these effects,F is substituted into the amorphous oxyhalide.The optimized composition(LTOC-8%F)exhibits enhanced structural characteristics consistent with this mechanism,and a corresponding elevated theoretical room-temperature ionic conductivity of 7.22 mS cm^(−1).This study reveals the origins of fast ion transport in amorphous oxyhalide SSEs and establishes a mechanism-informed design strategy.