期刊
NANO ENERGY
卷 13, 期 -, 页码 192-199出版社
ELSEVIER
DOI: 10.1016/j.nanoen.2015.02.020
关键词
Lithium ion battery; Stress; Diffusion; Silicon; ab initio molecular dynamics; Potentiostatic intermittent titration technique
类别
资金
- Center for Computational Sciences at University of Kentucky
- National Science Foundation [CMMI 1000726, 1355438]
- Department of Energy
- Office of Vehicle Technologies of the U.S. Department of Energy [DE-AC02-05CH11231, 7056410]
- Directorate For Engineering
- Div Of Civil, Mechanical, & Manufact Inn [1000726] Funding Source: National Science Foundation
- Office Of The Director
- Office of Integrative Activities [1355438] Funding Source: National Science Foundation
Silicon, as a promising electrode material for high energy density lithium ion batteries, experiences large strains and stresses during lithiation and delithation. The coupling effect between stress and lithium diffusion leads to a grand challenge to optimizing the design of Si electrodes with high capacity and high rate capability, particularly considering the amorphization of Si during initial cycles. In this study, we established a relationship between stress and the diffusion coefficients of Li in amorphous Si by ab initio molecular dynamics calculations (AIMD). The prediction from AIMD was validated by the potentiostatic intermittent titration measurements. Our results showed that two Li diffusion mechanisms can operate depending on the stress state. Specifically, the stress can increase Li diffusion either through increasing free volume under tension or by changing local structure under compression. However, within the range of stress generated during the lithiation and delithation process, diffusion coefficients are expected to vary by only one order of magnitude. (C) 2015 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据