Effects of Temperature on the Crystal Structure of Lithium-Lanthanum Zirconate

Lithium-lanthanum zirconate (LLZ) can potentially be used as a solid electrolyte in lithium-metal batteries. Li-metal batteries offer superior charge capacities and higher energy densities compared to currently used Li-ion batteries. Lithium is highly reactive, which can be dangerous in consumer electronics, but a layer of LLZ electrolyte inserted alongside the Li-metal electrode greatly stabilizes its reactivity. The cubic phase structure of LLZ (Li7La3Zr2O12) has the highest conductivity of its crystalline phases, making it the most promising crystal form of LLZ for this application. Samples of LLZ were doped with different amounts of aluminum and heated to high temperatures in a furnace while measuring in-situ x-ray diffraction data. The aim of this project was to calibrate and integrate the data. Preliminary results show that different crystallographic phases form as the samples are heated. The amount of aluminum present plays a major role in stabilizing the cubic phase.