Particle Morphology and Lithium Segregation to Surfaces of the Li\(_7\)La\(_3\)Zr\(_2\)O\(_{12}\) Solid Electrolyte

• Published in: arXiv.org 2018-04
• Main Authors: Canepa, Pieremanuele, Dawson, James A, Gopalakrishnan Sai Gautam, Statham, Joel M, Parker, Stephen C, M Saiful Islam
• Format: Article
• Language: English
• Subjects: Conductors; Dendritic structure; Density functional theory; Electrolytes; Energy storage; First principles; Grain boundaries; Ion currents; Lithium; Lithium-ion batteries; Molten salt electrolytes; Morphology; Organic chemistry; Rechargeable batteries; Solid electrolytes; Solid state devices; Storage batteries; Zirconium
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1804.05165

Solid electrolytes for solid-state Li-ion batteries are stimulating considerable interest for next-generation energy storage applications. The Li\(_7\)La\(_3\)Zr\(_2\)O\(_{12}\) garnet-type solid electrolyte has received appreciable attention as a result of its high ionic conductivity. However, several challenges for the successful application of solid-state devices based on Li\(_7\)La\(_3\)Zr\(_2\)O\(_{12}\) remain, such as dendrite formation and maintaining physical contact at interfaces over many Li intercalation/extraction cycles. Here, we apply first-principles density functional theory to provide insights into the Li\(_7\)La\(_3\)Zr\(_2\)O\(_{12}\) particle morphology under various physical and chemical conditions. Our findings indicate Li segregation at the surfaces, suggesting Li-rich grain boundaries at typical synthesis and sintering conditions. On the basis of our results, we propose practical strategies to curb Li segregation at the Li\(_7\)La\(_3\)Zr\(_2\)O\(_{12}\) interfaces. This approach can be extended to other Li-ion conductors for the design of practical energy storage devices.