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: 1620901
• 负责人: Reza Shahbazian- Yassar
• 金额: $ 42.82万
• 依托单位: University of Illinois at Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-16 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1620901&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.

为了增加锂离子电池的能量和功率，世界范围内正在进行广泛的研究，以寻找更好的锂离子电池材料。过渡金属氧化物作为锂离子电池的电极具有优越的性能；然而，由于缺乏对其电化学性能的了解，阻碍了其商业化应用的进展。特别是，局部原子结构和化学的变化需要更好地研究，以便为可充电电池应用适当地设计它们。在材料研究部固态和材料化学项目的支持下，该项目将努力解决这一缺点。首席研究员计划在高分辨率电子显微镜中研究电化学电池反应，从而实现原子水平的成像。有了这种能力，锂离子在电池电极内部的运动可以在存在结构缺陷的情况下进行研究。纳米过渡金属氧化物（TMO）是锂离子电池极具发展前景的材料。这些材料通过转化反应起作用，并与高能量密度有关。这些材料非常容易受到合成过程中产生的结构缺陷的影响，这些缺陷会改变锂离子的路径并影响它们的电化学性能。这项研究活动的目的是了解结构缺陷（如异质界面和位错）影响TMOs锂化行为的潜在原子机制。为了实现这一目标，纳米级TMOs在原子分辨率透射电子显微镜下进行了实时电化学锂化。该项目有望更好地理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通路的影响。此外，在异质界面和位错存在的情况下，可以研究转化反应相的结构演变。