期刊
JOURNAL OF POWER SOURCES
卷 273, 期 -, 页码 41-51出版社
ELSEVIER
DOI: 10.1016/j.jpowsour.2014.09.073
关键词
Lithium ion batteries; Lithiation; Nanoindentation; Silicon
资金
- Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy [DE-FG02-04ER46163]
- U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering through the SLAC National Accelerator Laboratory LDRD project [DE-AC02-76SF00515]
- Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy under the Batteries for Advanced Transportation Technologies Program [DE-AC02-05CH11231, 6951379]
The time-independent and time-dependent mechanical behavior of electrochemically lithiated silicon was studied with nanoindentation. As indentation was performed with continuous stiffness measurements during loading and load-hold, new insight into the deformation behavior of lithiated silicon is furnished. Supporting other research, Young's modulus and the hardness of lithiated silicon are found to decline with increasing lithium content. However, the results of this study indicate that Young's modulus of the fully lithiated phase, at 41 GPa, is in fact somewhat larger than reported in some other studies. Nanoindentation creep experiments demonstrate that lithiated silicon creeps readily, with the observed viscoplastic flow governed by power law creep with large stress exponents (>20). Flow is thought to occur via local, shear-driven rearrangement at the scale of the Li15Si4 molecular unit volume. This research emphasizes the importance of incorporating viscoplasticity into lithiation/delithiation models. Additionally, more broadly, the work offers insight into nanoindentation creep methodology. (C) 2014 Elsevier B.V. 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