Current lithium ion battery technology makes use of flammable liquid electrolytes and so the development of solid ceramic electrolytes for the next generation of all-solid-state batteries can offer a safer alternative. However, the lithium diffusion behaviour in these solid electrolytes is not yet well characterised, despite the importance of this information for optimising cell performance. Similarly, the transport properties at the metal anode interface are critically important, but not well understood. We propose a methodology for obtaining lithium diffusion coefficients of bulk solid ceramic garnet-type Li₇La₃Zr₂O₁₂ (LLZO) electrolytes by coupling dense pellets with isotopically labelled lithium metal, followed by analysis with focused-ion-beam secondary ion mass spectrometry. We report room temperature lithium diffusivities of 2–8 10⁻¹³ m² s⁻¹ for doped LLZO using an estimate of the lithium diffusion length in good agreement with electrochemical impedance spectroscopy. Simultaneous detection of positive and negative secondary ion species by SIMS enables correlation of layered interfaces consisting of metallic lithium, corrosion/surface degradation products and bulk LLZO during depth profiling. Charging of the ceramic during ion sputtering is investigated and shown to have a minimal effect on the obtained lithium isotopic fractions in the current setup. Additionally, the effect of the presence of corrosion products at the surface of garnets as a result of air-exposure is investigated. This method could be extended to any Li-metal stable solid electrolyte, or with a reactive solid electrolyte coupled with a stable interlayer. As such, this work sets the basis of a methodology for further quantitative diffusion analyses for Li-conducting solid ceramic electrolytes and their interfaces with electrodes, as used in both solid-state lithium batteries and hybrid systems coupling solid and liquid electrolytes.

当前的锂离子电池技术使用易燃液体电解质，因此为下一代全固态电池开发固体陶瓷电解质可以提供更安全的替代方案。然而，尽管这些信息对于优化电池性能很重要，但这些固体电解质中的锂扩散行为尚未得到很好的表征。类似地，金属阳极界面的传输特性至关重要，但尚未得到很好的理解。我们提出了一种获得大块固体陶瓷石榴石型 Li ₇ La ₃ Zr ₂ O _{12 的}锂扩散系数的方法(LLZO) 电解质，通过将致密颗粒与同位素标记的锂金属耦合，然后使用聚焦离子束二次离子质谱法进行分析。我们报告了 2–8 10 ^-13 m ² s ^{-1 的}室温锂扩散率对于掺杂的 LLZO，使用与电化学阻抗谱非常一致的锂扩散长度的估计。通过 SIMS 同时检测正负二次离子种类，可以在深度剖析过程中关联由金属锂、腐蚀/表面降解产物和块状 LLZO 组成的层状界面。研究了离子溅射过程中陶瓷的充电，并表明对当前设置中获得的锂同位素分数的影响最小。此外，还研究了由于暴露在空气中而在石榴石表面存在腐蚀产物的影响。这种方法可以扩展到任何锂金属稳定的固体电解质，或与稳定的夹层耦合的反应性固体电解质。像这样，