Fundamental Understanding on the Role of Structural Defects on Lithiation of Nanoscale Transition Metal Oxides

结构缺陷对纳米过渡金属氧化物锂化作用的基本认识

• 批准号: 1410560
• 负责人: Reza Shahbazian- Yassar
• 金额: $ 44.57万
• 依托单位: Michigan Technological University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-15 至 2016-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1410560&HistoricalAwards=false
• 关键词: Fundamental; Understanding; Role; Structural; Defects

Non Technical AbstractExtensive research worldwide is underway to find better materials for Li-ion batteries in order to increase their energy and power. Transition metal oxides offer superior performance as electrodes for lithium-ion batteries; however, the progress toward their commercial use has been hindered due to lack of understanding of their electrochemical performance. In particular, variations in local atomic structure and chemistry need to be better investigated in order to properly design them for rechargeable battery applications. With support from the Solid State and Materials Chemistry program in the Division of Materials Research, this project will work to address this shortcoming. The principal investigator plans to study the electrochemical battery reactions inside high-resolution electron microscopes enabling imaging down to atomic level. With this capability, lithium-ion movements inside the battery electrodes can be investigated in the presence of structural defects.Technical AbstractNanoscale transition metal oxides (TMO) are promising materials for lithium-ion batteries. These materials operate through conversion reactions and are associated with high energy densities. These materials are highly vulnerable to structural defects produced during synthesis that can alter lithium ion pathways and affect their electrochemical performance. The objective of this research activity is to understand the underlying atomistic mechanisms by which structural defects such as heterointerfaces and dislocations affect the lithiation behavior of TMOs. To meet this goal, nanoscale TMOs are subjected to real time electrochemical lithiation inside atomic-resolution transmission electron microscopes. This project is expected to yield better understanding on the evolution of localized strain and electronic structure at the vicinity of structural defects and their effect on lithium-ion pathways. In addition, the structural evolution of conversion reaction phases can be investigated in the presence of heterointerfaces and dislocations.

全世界的非技术抽象扩展研究正在进行中，以寻找更好的锂离子电池材料，以增加其能量和力量。过渡金属氧化物作为锂离子电池的电极提供了出色的性能；但是，由于缺乏对其电化学性能的了解，因此阻碍了其商业用途的进展。 特别是，需要对局部原子结构和化学的变化进行更好的研究，以便将它们适当地设计用于可充电电池应用。在材料研究部固态和材料化学计划的支持下，该项目将致力于解决这一缺点。主要研究者计划研究高分辨率电子显微镜内部的电化学电池反应，使成像降低到原子水平。有了这种能力，可以在结构缺陷的情况下研究电池电极内部的锂离子运动。技术抽象纳米级过渡金属氧化物（TMO）是锂离子电池的有前途的材料。这些材料通过转化反应运行，并与高能密度相关。这些材料高度容易受到合成过程中可能改变锂离子途径并影响其电化学性能的结构缺陷的影响。这项研究活动的目的是了解结构缺陷（例如异质空间和位错）会影响TMO的岩性行为的基本原子机制。为了实现这一目标，纳米级TMO会在原子分辨率传输电子显微镜内进行实时电化学固定。预计该项目将更好地了解结构缺陷附近局部应变和电子结构的演变及其对锂离子途径的影响。另外，可以在异源空间和位错的存在下研究转化反应阶段的结构演变。