Lithium dendrites hinder the development of solid-state batteries with lithium metal anodes. This study explores amorphous Li₇La₃Zr₂O₁₂ (LLZO) as a dendrite shield due to its grain-boundary-free structure, stability against lithium metal, and high electronic insulation. Tuning lithium stoichiometry increased ionic conductivity by four orders of magnitude while maintaining negligible electronic conductivity. Symmetric cells showed no lithium penetration up to 3.2 mA cm⁻². Microbatteries with 70 nm electrolytes cycled at 10C for over 500 cycles. Amorphous Li-La-Zr-O coatings on crystalline LLZO lowered interface resistance and increased critical current density.

Jordi Sastre, Moritz H. Futscher, Lea Pompizi, Abdessalem Aribia, Agnieszka Priebe, Jan Overbeck, Michael Stiefel, Ayodhya N. Tiwari, Yaroslav E. Romanyuk