Crystal Structure, Ionic Conduction, and Electrochemistry of Novel Garnet Oxides Li5+x+2yLa3Ta2-x-yZrxScyO12

非技术描述：最先进的锂离子电池中的液体电解质含有挥发性和易燃的有机溶剂，并且在大规模应用中广泛采用这些电池引起了安全问题。相比之下，具有高离子电导率和稳定性的固体电解质可能会彻底改变电池的设计，并提供卓越的安全性。本课题研究一类新型固体电解质锂石榴石氧化物的基本结构-性能关系。更好地了解这些复合氧化物的结构将有助于深入了解离子传导路径，并为寻找其他高性能材料提供指导。该项目还启动了一项独特的“你身边的电池材料”（MBAY）外展计划，以激发K-12学生对电池材料科学和工程原理的兴趣。技术细节：该项目旨在研究锂石榴石氧化物新家族Li(5+x+2y)La(3)Ta(2-x-y)Zr(x)Sc(y)O（12）的晶体结构，离子传导和电化学，涵盖配方5至9的锂含量。科学目标是通过实验和建模相结合的努力，找出四面体/八面体位置的总锂含量和锂无序性对离子传导机制的影响。利用Bragg散射（Rietveld细化）和漫射散射（对分布函数）研究了平均结构和局部结构。这种全散射研究，以及一种新的平均场能量建模方法，有助于揭示锂无序的原子特征和这些复杂氧化物中的传导机制。这些氧化物作为固体电解质在锂电池中的电化学性能正在被评价。该项目为研究生和本科生提供多学科研究活动，并可能发现对可再生能源未来至关重要的固体电解质。

NON-TECHNICAL DESCRIPTION: The liquid electrolytes in the state-of-the-art lithium ion batteries contain volatile and flammable organic solvents and have raised safety concerns over the wide adoption of these batteries in large-scale applications. In contrast, solid electrolytes with high ionic conductivity and stability could potentially revolutionize the battery design and provide superior safety. This project studies the fundamental structure-property relation of a new family of solid electrolytes, namely lithium garnet oxides. A better understanding of the structure of these complex oxides will provide insight into the ionic conduction path and provide guidance in the search for other high performance materials. This project also enables a unique Materials in Batteries Around You (MBAY) outreach program to inspire the interests of K-12 students in the materials science and engineering principles involved in batteries.TECHNICAL DETAILS: This project aims to study the crystal structure, ionic conduction, and electrochemistry of a new family of lithium garnet oxides, Li(5+x+2y)La(3)Ta(2-x-y)Zr(x)Sc(y)O(12) covering lithium content per formula from 5 to 9. The scientific goal is to find the effect of the total lithium content and lithium disorder in tetrahedral/octahedral sites on the ionic conduction mechanisms, through a combined experimental and modeling effort. The average structure and local structure is being studied by the Bragg scattering (Rietveld refinement) and diffuse scattering (pair distribution function). This total scattering investigation, along with a novel mean-field energetic modeling approach, is helping to unravel the atomistic features of lithium disorder and conduction mechanisms in these complex oxides. The electrochemical performance of these oxides is being evaluated as solid electrolytes in lithium batteries. This project provides multidisciplinary research activities for students at both the graduate and undergraduate levels and could enable the discovery of solid electrolytes essential to a renewable energy future.