A solid-state route to stabilize cubic LiLaZrO at low temperature for all-solid-state-battery applications.

The integration of a solid electrolyte with electrodes without interfacial degradation is an integral part of enabling high-performance all-solid-state batteries. Here we highlight that additive-assisted solid-state reactions using high-energy ball-milling and multistep heating can be an effective approach to lower the processing temperatures of cubic Li7La3Zr2O12 garnet. The obtained total Li conductivity is 1.4 × 10-4 S cm-1, comparable with that obtained using high-temperature processing. We found that liquid-phase sintering triggered by a lithium borate additive increases the microstrain of Li7La3Zr2O12, increasing Li conductivity. Our work demonstrates the feasibility to engineer conventional ceramics processing to sustainably produce all-solid-state batteries with a low thermal budget in practice.