Surface Coating for High-Capacity Electrodes in Li-ion Batteries: in-situ TEM Characterization and First-Principles Modeling

锂离子电池高容量电极的表面涂层：原位 TEM 表征和第一原理建模

• 批准号: 1603866
• 负责人: Kejie Zhao
• 金额: $ 25.47万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1603866&HistoricalAwards=false
• 关键词: Surface; Coating; Capacity; Electrodes; Li

Rechargeable lithium ion batteries help to enable sustainable energy systems by storing electricity generated by intermittent renewable resources such as wind and solar energy, or by powering zero-emission electric vehicles charged by electricity from renewable resources. However, lithium ion batteries designed for high energy storage capacity suffer from rapid power capacity loss over repeated charge and discharge cycles. This project seeks to elucidate of the underlying mechanisms of capacity loss through microscopic investigation of the changes in battery electrode structure during charging and recharging using transmission electron microscopy (TEM), which enables visualization at the nanometer scale. The microscopic study will be complimented by mathematical modeling studies that seek to predict the observed behavior. The educational activities associated with this project focus on hands-on outreach activities for middle school students on battery technology, coordinated through the Women in Engineering program at Purdue University. The overall goal of this research is to investigate how metal oxide coatings on high-capacity, lithium ion battery electrodes affect charge capacity fade through in-situ transmission electron microcopy (TEM) experiments and first-principles modeling. Surface coatings can potentially mitigate the degradation of electrodes through regulation of the electrochemical process of lithiation and the remediation of deformation dynamics. However, the electro-chemo-mechanical behavior of the coating materials is poorly understood. To develop a fundamental understanding of these processes, the research plan has two major objectives. The first objective is to synthesize core-shell structures of metal oxide-coated nanowires to directly observe the lithiation reaction and the morphological evolution and phase transitions associated with it using real-time, in situ TEM. The second objective is to perform first-principles atomistic modeling to develop a complimentary fundamental understanding of the effects of lithium ion insertion and extraction on electronic structure, crystal lattice structure, and structural stability. Through these objectives, the proposed research will determine the thermodynamics of diffusive reactions and phase transitions, the kinetics of structural evolution, ionic transport, and interfacial reactions, as well as the mechanical properties of the lithiated phases in the coating materials. The knowledge gained from this work will facilitate the selection of coating materials for high-capacity lithium ion batteries, and advance fundamental understanding of the intrinsic mechanisms underlying the cyclic performance of Li-ion batteries.

可充电锂离子电池通过存储由间歇性可再生资源（例如风能和太阳能）产生的电力，或通过为可再生资源电力收取的零发射电动汽车而产生的电力来实现可持续的能源系统。 但是，设计用于高能量存储容量的锂离子电池遭受重复充电和放电周期的快速功率损失。该项目旨在通过微观研究使用透射电子显微镜（TEM）来阐明电池电极结构的变化，以阐明能力损失的潜在机制，从而使纳米尺度可视化。微观研究将通过试图预测观察到的行为的数学建模研究来称赞。与该项目相关的教育活动集中于中学学生的动手外展活动，该活动是通过普渡大学的工程女性协调的。这项研究的总体目标是研究高容量，锂离子电池电极上的金属氧化物涂层如何通过原位传输电子微拷贝（TEM）实验和第一原理建模影响电荷的容量。 表面涂层可以通过调节静脉化学过程和变形动力学的修复来减轻电极的降解。 但是，涂料材料的电化学行为尚不清楚。为了发展对这些过程的基本理解，研究计划有两个主要目标。第一个目的是合成金属氧化物涂层纳米线的核壳结构，以直接观察岩性反应以及使用实时的原位tem与IT相关的形态演化和相变。第二个目标是执行第一原子原子模型，以对锂离子插入和提取对电子结构，晶体晶格结构和结构稳定性的影响的影响进行免费的基本了解。 通过这些目标，提出的研究将确定扩散反应和相变的热力学，结构进化的动力学，离子转运和界面反应的动力学以及涂层材料中熔融相的机械性能。从这项工作中获得的知识将有助于选择用于高容量锂离子电池的涂料材料，并提高对锂离子电池环状性能的内在机制的基本理解。