Anisotropic mechanical properties of Si anodes in a lithiation process of lithium-ion batteries

作者：Wang, Dan; Wang, Yan; Zou, Youlan; Lu, Chunsheng; Ma, Zengsheng^*

来源：Acta Mechanica, 2018, 229(8): 3293-3303.

DOI：10.1007/s00707-018-2169-4

• DIFFUSION-INDUCED STRESSES
• ELECTROCHEMICAL LITHIATION
• SECONDARY CELLS
• SILICON
• ELECTRODES
• MODEL
• DEFORMATION
• FRACTURE

High-capacity active electrodes, such as Si anodes in Li-ion batteries, undergo a significant volume deformation of up to similar to 400% during lithiation. Such a huge volume change could cause mechanical fracture and pulverization of electrode materials and result in harmful effects on their electrochemical performance. To have better understanding on this problem, the two-phase lithiation process of hollow core-shell and film structural electrodes is simulated by using a diffusion lithiation model. It is shown that the anisotropic hoop stress is larger than the isotropic one, which may easily induce damage of hollow core-shell negative electrodes. In addition, the anisotropic nature of mechanical properties can also remarkably magnify the edge stress intensity factor of hollow core-shell and film electrodes. These results on the morphological evolution and stress generation shed light on the design of novel and failure-resistant electrodes.

• 出版日期2018-8
• 单位湘潭大学; 湖南科技大学