In-Situ Experiment and Modeling of Electrode Failures in Li Ion Nano-batteries

锂离子纳米电池电极失效的原位实验和建模

• 批准号: 1100205
• 负责人: Ting Zhu
• 金额: $ 35万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1100205&HistoricalAwards=false
• 关键词: Situ; Experiment; Modeling; Electrode; Failures

The research objective of this grant is to elucidate the mechanisms of electrochemically driven mechanical failures in silicon nanowire electrodes for Lithium ion batteries. In-situ experiments and modeling of nanoscale batteries will be performed to investigate the failures in single nanowire electrodes. The proposed research involves three tightly coupled thrusts: (i) A nanomechanical testing device will be used to quantitatively measure the mechanical properties of lithiated silicon nanowires. (ii) The in-situ electron microscopy imaging will reveal the real-time processes of electrochemical reaction induced deformation, amorphization, and cracking. (iii) Atomistic and finite element modeling will enable the understanding of stress generation, crack initiation and growth on the time and size scales of battery experiments with atomic scale fidelity. Advanced battery technologies are critically important for applications from portable electronics to electric vehicles. Lithium ion batteries are presently the best performing ones, but they are limited in capacity and reliability. Silicon is being considered as a promising electrode for Lithium ion batteries, due to its highest theoretical charge capacity. However, Silicon electrodes often suffer from mechanical degradation, leading to capacity fading. Currently, there is a lack of understanding of the stress generation and failure mechanisms in lithiated Silicon. This project will show and explain when, where, and how the crack initiates and propagates in lithiated silicon nanowires. Results will provide insights into electrode failures that cannot be offered by traditional battery testing. This research will provide the basis for understanding, controlling, and mitigating materials degradation in high capacity Lithium ion batteries.

这项拨款的研究目的是阐明锂离子电池用硅纳米线电极电化学驱动机械故障的机制。将进行纳米级电池的现场实验和建模，以研究单纳米线电极的失效。拟议的研究涉及三个紧密耦合的推力：(I)将使用纳米机械测试装置来定量测量锂化硅纳米线的机械性能。(Ii)原位电子显微镜成像将实时揭示电化学反应引起的变形、非晶化和破裂过程。(Iii)原子模拟和有限元模拟将能够以原子尺度的保真度在电池实验的时间和尺寸尺度上理解应力产生、裂纹萌生和扩展。先进的电池技术对于从便携式电子产品到电动汽车的应用至关重要。锂离子电池是目前性能最好的电池，但它们的容量和可靠性有限。硅因其最高的理论充电容量而被认为是锂离子电池的一种很有前途的电极。然而，硅电极经常遭受机械退化，导致容量衰退。目前，对于锂化硅的应力产生和失效机制还缺乏了解。这个项目将展示和解释裂纹何时、何地以及如何在锂化硅纳米线中开始和传播。结果将提供对传统电池测试无法提供的电极故障的深入了解。这一研究将为理解、控制和缓解高容量锂离子电池中的材料降解提供基础。