New Publication in Chem. Mater.

We are pleased to announce that our latest research paper has been accepted for publication in Chemistry of Materials. In this work, we found that lithium nonstoichiometry in tetragonal Li₇La₃Zr₂O₁₂ significantly reduce the activation energy for Li⁺ ion diffusion, increasing room-temperature ionic conductivity by 10 orders of magnitude and lowering the phase transition temperature to stabilize the high-conductivity cubic phase.

Research Highlights

• Small deviations from stoichiometry, particularly lithium deficiency, dramatically reduce the activation energy for Li⁺ diffusion in tetragonal LLZO, increasing room-temperature ionic conductivity by 10 orders of magnitude.
• We resolve the longstanding discrepancy between computational predictions and experimental measurements of ionic conductivity in tetragonal LLZO.
• Lithium nonstoichiometry was found to affect the phase transition temperature (T_c) of the tetragonal-to-cubic phase, potentially stabilizing the high-conductivity cubic phase at lower temperatures.

These findings provide crucial insights into the atomic-scale mechanisms underlying the enhanced performance of nonstoichiometric LLZO and offer a promising avenue for the optimization of solid electrolytes through defect engineering. Our work bridges the gap between theoretical predictions and experimental observations, emphasizing the necessity of incorporating realistic defect concentrations in theoretical studies. In addition, this study underscores the critical importance of considering and controlling the lithium content in the development of high-performance all-solid-state lithium batteries. It opens new avenues for tailoring the properties of solid electrolytes through careful manipulation of stoichiometry, paving the way for the rational design of next-generation solid electrolytes with enhanced ionic conductivity and improved phase stability.