The article explores the structural regulation of halide superionic conductors for all-solid-state lithium batteries. Metal halide solid-state electrolytes are gaining attention due to their high ionic conductivities, wide electrochemical stability windows, and compatibility with oxide cathode materials. The study introduces the cationic polarization factor (τ) as a critical descriptor for predicting the stacking structure of halide electrolytes, which can guide the design and preparation of more effective halide electrolytes. By synthesizing over 10 lithium halide electrolytes with high conductivity, the researchers demonstrate that there are many promising halide electrolytes yet to be discovered. The cationic polarization factor is effective in predicting the stacking structure of halide electrolytes, and it can be used to systematically screen various potential halide electrolytes. The study also highlights the importance of controlling the composition and crystal structure to achieve high ionic conductivity and structural stability. The findings provide a valuable tool for accelerating the discovery of new halide electrolytes with superionic conductivity.The article explores the structural regulation of halide superionic conductors for all-solid-state lithium batteries. Metal halide solid-state electrolytes are gaining attention due to their high ionic conductivities, wide electrochemical stability windows, and compatibility with oxide cathode materials. The study introduces the cationic polarization factor (τ) as a critical descriptor for predicting the stacking structure of halide electrolytes, which can guide the design and preparation of more effective halide electrolytes. By synthesizing over 10 lithium halide electrolytes with high conductivity, the researchers demonstrate that there are many promising halide electrolytes yet to be discovered. The cationic polarization factor is effective in predicting the stacking structure of halide electrolytes, and it can be used to systematically screen various potential halide electrolytes. The study also highlights the importance of controlling the composition and crystal structure to achieve high ionic conductivity and structural stability. The findings provide a valuable tool for accelerating the discovery of new halide electrolytes with superionic conductivity.