Crystallographically Guided Discovery of Li-Rich Garnet Solid Electrolytes for All-Solid-State Batteries

The development of high-performance all-solid-state batteries requires solid electrolytes with high ionic conductivity and lithium metal stability. Although Li7La3Zr2O12 (LLZO) garnet is promising, it suffers from interfacial instability and lithium loss. This study proposes a crystallography-based design strategy for Li7-type garnet electrolytes. By evaluation of the ionic radii and tolerance factors across 247 cationic combinations, 38 compositions with structural compatibility comparable to LLZO were identified. The results emphasize the importance of balanced ionic size matching across crystal sites for framework stability, offering a rational screening method to accelerate the discovery of next-generation solid electrolytes.