Among the Li-ion conducting inorganic materials, lithium lanthanum zirconate (LLZO) is believed to possess good chemical stability against Li metal and hence considered to be a promising solid electrolyte for Li-ion batteries. However, systematic sets of studies conducted here at regular intervals during storage of Al-doped LLZO (cubic garnet) sintered pellets in ambient atmosphere have raised serious concerns over their structural/mechanical stability/integrity upon exposure to air. Spontaneous cracking/disintegration/pulverization of LLZO pellets takes place after about three weeks of exposure, primarily due to formation of La₂Zr₂O₇ in the LLZO bulk; as found to be thermodynamically feasible at room temperature upon reaction with CO₂/moisture. Steep increase in La₂Zr₂O₇ content coincides with the spontaneous cracking/disintegration. Estimation suggests that internal stresses associated with the formation of La₂Zr₂O₇ from LLZO can be high enough to cause spontaneous fracture. This mandates the development/fabrication/usage of solid-state cells using LLZO under stringent controls against exposure to atmospheric species.

在传导锂离子的无机材料中，锆酸镧锂（LLZO）被认为对锂金属具有良好的化学稳定性，因此被认为是锂离子电池的一种有前途的固体电解质。然而，在这里，在将Al掺杂的LLZO（立方石榴石）烧结的小球储存在环境中的过程中，定期进行系统的研究引起了人们对它们暴露于空气中的结构/机械稳定性/完整性的严重关注。暴露约三周后，LLZO颗粒会自发破裂/崩解/粉碎，这主要是由于在LLZO本体中形成了La ₂ Zr ₂ O ₇。经发现与CO ₂反应在室温下在热力学上是可行的/水分。La ₂ Zr ₂ O ₇含量的急剧增加与自发裂化/崩解相吻合。估计表明与LLZO形成La ₂ Zr ₂ O ₇相关的内部应力可能足够高，从而导致自发破裂。这要求在严格的控制下使用LLZO来开发/制造/使用固态电池，以免暴露于大气中。