Lithium dendrites have become a roadblock in the realization of solid-state batteries with lithium metal as high-capacity anode. The presence of surface and bulk defects in crystalline electrolytes such as the garnet Li₇La₃Zr₂O₁₂ (LLZO) facilitates the growth of these hazardous lithium filaments. Here we explore the amorphous phase of LLZO as a lithium dendrite shield owing to its grain-boundary-free microstructure, stability against lithium metal, and high electronic insulation. By tuning the lithium stoichiometry, the ionic conductivity can be increased by 4 orders of magnitude while retaining a negligible electronic conductivity. In symmetric cells, plating-stripping shows no signs of lithium penetration up to 3.2 mA cm⁻². The dense conformal nature of the films enables microbatteries with an electrolyte thickness of only 70 nm, which can be cycled at 10C for over 500 cycles. The application of this material as a coating on crystalline LLZO lowers the interface resistance and increases the critical current density. The effectiveness of the amorphous Li-La-Zr-O as dendrite blocking layer can accelerate the development of better solid-state batteries.

锂枝晶已成为实现以锂金属作为高容量负极的固态电池的障碍。晶体电解质（如石榴石 Li ₇ La ₃ Zr ₂ O ₁₂ (LLZO)）中表面和本体缺陷的存在促进了这些危险锂丝的生长。在这里，我们探索了 LLZO 的非晶相作为锂枝晶屏蔽层，因为它具有无晶界的微观结构、对锂金属的稳定性和高电子绝缘性。通过调整锂的化学计量，离子电导率可以增加 4 个数量级，同时保持可忽略不计的电子电导率。在对称电池中，电镀剥离显示出锂渗透高达 3.2 mA cm 的迹象^－2．薄膜的致密共形特性使微电池的电解质厚度仅为 70 nm，可在 10°C 下循环超过 500 次。这种材料作为结晶 LLZO 上的涂层的应用降低了界面电阻并增加了临界电流密度。无定形 Li-La-Zr-O 作为枝晶阻挡层的有效性可以加速更好的固态电池的开发。