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液含有挥发性和易燃的有机溶剂，并对这些电池在大规模应用中的广泛采用提出了安全问题。相比之下，具有高离子导电性和稳定性的固体电解质可能会给电池设计带来革命性的变化，并提供卓越的安全性。本项目研究了一类新的固体电解质，即锂石榴石氧化物的基本结构-性质关系。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途径，并为寻找其他高性能材料提供指导。这个项目还启动了一个独特的电池材料推广计划(MBAY)，以激发K-12年级学生对电池所涉及的材料科学和工程原理的兴趣。技术细节：该项目旨在研究一类新的锂石榴石氧化物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。科学目标是发现锂的总含量和四面体/八面体位置上的锂无序对离子传导机制的影响。通过实验和建模相结合的方式。用布拉格散射(Rietveld精细化)和扩散散射(对分布函数)研究了平均结构和局域结构。这种全散射研究，以及一种新的平均场能量模拟方法，有助于揭开这些复杂氧化物中锂无序和传导机制的原子特征。这些氧化物的电化学性能正在作为锂电池的固体电解液进行评估。该项目为研究生和本科生提供多学科的研究活动，并能够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.