An Interatomic Potential for LixSi Alloys and Its Applications to Lithiation Induced Deformation and Failure in Silicon

LixSi 合金的原子间势及其在锂化引起的硅变形和失效中的应用

• 批准号: 1200075
• 负责人: jianmin qu
• 金额: $ 36.65万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2016-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1200075&HistoricalAwards=false
• 关键词: Interatomic; Potential; LixSi; Alloys; Its

The goals of this project are (1) to obtain an interatomic potential for LixSi Alloys and (2) to use this interatomic potential to study the lithiation induced deformation and failure of silicon anode in lithium-ion batteries. Making solar energy economical and providing energy from fusion are two of the grand challenges identified by the National Academy of Engineering. A key component of both challenges is energy storage. At the moment, the most economical and efficient way of storing solar energy is electrical battery. Lithium-ion battery is considered the most promising technology for high density energy storage, and silicon is the highest capacity anode material. Despite the rapid development and significant progress made in recent years, capacity degradation and short lifetime have not been solved for silicon based anodes. Among other things, the lack of understanding of the mechanisms for lithium insertion/extraction, and the lack of efficient tools for designing Si-based anodes are the major roadblocks that prevent the technology breakthroughs for commercialization.To meet the above needs, this project is (1) to obtain an interatomic potential for LixSi Alloys and (2) to use this interatomic potential to study the deformation and failure of silicon anode in lithium ion batteries. Such an interatomic potential for LixSi alloys will be a powerful tool. It enables us to validate the various continuum models on lithium insertion. It can be used to estimate some of the material properties that are difficult to obtain experimentally. It gives us a mean to study the microstructural mechanisms of fracture and failure.Besides contributing to science and engineering, the research activities will also have a broader impact on educating students by (1) integrating the research results into a core engineering course, "Multi-scale Modeling", (2) recruiting undergraduates for research, focusing on women and minorities, (3) providing a platform for cross-department interactions among graduate students, and (4) recruiting local high school teachers and students for summer research experience in the PI's lab.

该项目的目标是：(1)获得LixSi合金的原子间电势，(2)利用该原子间电势研究锂离子电池中硅阳极的锂化引起的变形和失效。美国国家工程院（National Academy of Engineering）认为，使太阳能经济实惠和通过核聚变提供能源是两大挑战。这两个挑战的一个关键组成部分是能量储存。目前，最经济、最有效的储存太阳能的方法是电池。锂离子电池被认为是最有前途的高密度储能技术，而硅是容量最高的负极材料。尽管近年来硅基阳极发展迅速，取得了重大进展，但其容量退化和寿命短的问题尚未得到解决。除此之外，缺乏对锂插入/提取机制的理解，以及缺乏设计硅基阳极的有效工具是阻碍该技术实现商业化突破的主要障碍。为了满足上述需求，本项目是(1)获得LixSi合金的原子间电势，(2)利用该原子间电势研究锂离子电池中硅阳极的变形和失效。这种原子间电位对LixSi合金来说将是一个强大的工具。它使我们能够验证锂插入的各种连续体模型。它可以用来估计一些难以通过实验获得的材料性质。这为研究断裂和破坏的微观组织机制提供了一种手段。除了对科学和工程做出贡献外，研究活动还将通过以下方式对教育学生产生更广泛的影响：(1)将研究成果整合到核心工程课程“多尺度建模”中；(2)招募本科生进行研究，重点关注女性和少数民族；(3)为研究生提供跨部门互动的平台；(4)招募当地高中教师和学生到PI的实验室进行暑期研究体验。