Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7178246 | Journal of the Mechanics and Physics of Solids | 2014 | 13 Pages |
Abstract
We present a chemo-mechanical model to investigate the lithiation-induced phase transformation, morphological evolution, stress generation and fracture in crystalline silicon nanowires (c-SiNWs). The model couples lithium (Li) diffusion with elasto-plastic deformation in a three-dimensional (3D) setting. Several key features observed from recent transmission electron microscopy (TEM) studies are incorporated into the model, including the sharp interface between the lithiated amorphous shell and unlithiated crystalline core, crystallographic orientation dependent Li-Si reaction rate, and large-strain plasticity. Our simulation results demonstrate that the model faithfully predicts the anisotropic swelling of lithiated SiNWs observed from previous experimental studies. Stress analysis from the finite-deformation model reveals that the SiNWs are prone to surface fracture at the angular sites where two adjacent {110} facets intersect, consistent with previous experimental observations. The mechanistic understanding of the morphological evolution and stress generation sheds light on the design of failure-resistant nanostructured electrodes. Our model offers a framework for the study of the chemo-mechanical degradation in high-capacity electrode materials.
Related Topics
Physical Sciences and Engineering
Engineering
Mechanical Engineering
Authors
Hui Yang, Feifei Fan, Wentao Liang, Xu Guo, Ting Zhu, Sulin Zhang,