In situ measurement of biaxial modulus of Si anode for Li-ion batteries
In situ measurement of biaxial modulus of Si anode for Li-ion batteries
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DOI：
10.1016/j.elecom.2010.09.008
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发表时间：
2010-11-01
影响因子：
5.4
通讯作者：
Guduru, P. R.
中科院分区：
文献类型：
--
作者：
Sethuraman, V. A.;Chon, M. J.;Guduru, P. R.
我们报告在原位测量的硅薄膜电极的双轴模量作为其锂浓度的函数。在锂化期间，在Si膜中诱导双轴压应力，并且其经历塑性流动。在任何荷电状态（SOC）下，相对小的脱锂-再锂化序列弹性地卸载和重新加载膜。从脱锂-再锂化循环期间的应力和应变变化，计算膜的双轴模量。通过使用多光束光学传感器测量衬底曲率的变化来获得应力变化;从SOC的变化获得弹性应变变化。70 GPa（对于Li0.32Si）至约35 GPa（Li3.0Si）。弹性模量的这种显著降低对于模拟Si基阳极中的应力演变和机械退化具有重要意义。(C)2010 Elsevier B. V.保留所有权利。
We report in situ measurement of biaxial moduli of a Si thin-film electrode as a function of its lithium concentration. During lithiation, biaxial compressive stress is induced in the Si film and it undergoes plastic flow. At any state-of-charge (SOC), a relatively small delithiation-relithiation sequence unloads and reloads the film elastically. From the stress and strain changes during a delithiation-relithiation cycle, the biaxial modulus of the film is calculated. Stress change is obtained by measuring the change in substrate curvature using a Multi-beam Optical Sensor; the elastic strain change is obtained from the change in SOC. By repeating these measurements at several different values of SOC, the biaxial modulus was seen to decrease from ca. 70 GPa for Li0.32Si to ca. 35 GPa for Li3.0Si. Such a significant reduction in elastic modulus has important implications for modeling stress evolution and mechanical degradation in Si-based anodes. (C) 2010 Elsevier B.V. All rights reserved.