Ceramic membranes made of garnet Li₇Zr₃La₂O₁₂ (LLZO) are promising separators for lithium metal batteries because they are chemically stable to lithium metal and can resist the growth of lithium dendrites. Free-standing garnet separators can be produced on a large scale using tape casting and sintering slurries containing LLZO powder, but the quality of the separators is severely compromized by the protonation of the moisture-sensitive LLZO during processing and the irreversible loss of lithium during sintering. In this work, an approach is presented to mitigate the degradation of the LLZO and produce high quality separators using Li₂CO₃ as a source of excess lithium. By systematically investigating the effects of Li₂CO₃ addition during the different steps of the tape casting process and the intricate relationship between the protonation and relithiation of LLZO phase, the formation of highly protonated LLZO during ball milling was identified as the most critical step. It was shown that the addition of minimal amounts of Li₂CO₃ during wet milling effectively suppresses LLZO protonation and ensure the effectiveness of relithiation during subsequent sintering. Using this modified method, flat LLZO separators with a relative density of 95.3% were prepared in a simplified process with a significantly reduced excess lithium of only 5 mol% with respect to the stoichiometric LLZO, exhibiting an ionic conductivity of 0.18 mS cm⁻¹ at room temperature and a critical current density of 1 mA cm⁻² at 60°C for lithium stripping/plating.

_{由石榴石Li 7} Zr ₃ La ₂ O ₁₂ (LLZO)制成的陶瓷膜是很有前途的锂金属电池隔膜，因为它们对锂金属具有化学稳定性，并且可以抵抗锂枝晶的生长。独立式石榴石隔膜可以使用含有 LLZO 粉末的流延和烧结浆料大规模生产，但隔膜的质量因加工过程中湿气敏感的 LLZO 的质子化和烧结过程中锂的不可逆损失而严重受损。在这项工作中，提出了一种方法来减轻 LLZO 的降解并使用 Li ₂ CO ₃作为过量锂源来生产高质量的隔膜。通过系统地研究Li ₂ CO ₃添加在流延过程的不同步骤中的影响以及LLZO相的质子化和再锂化之间的复杂关系，球磨过程中高度质子化的LLZO的形成被认为是最关键的步骤。结果表明，湿磨过程中添加极少量的Li ₂ CO ₃可以有效抑制LLZO质子化，并确保后续烧结过程中重新锂化的有效性。使用这种改进的方法，通过简化的工艺制备了相对密度为95.3%的扁平LLZO隔膜，相对于化学计量的LLZO，过量的锂显着减少，仅5 mol%，在室温下表现出0.18 mS cm -1^的离子电导率。室温和60℃下锂剥离/镀覆的临界电流密度为1mA cm ^{-2 。}