In situ measurement of mechanical property and stress evolution in a composite silicon electrode

JOURNAL OF POWER SOURCES

卷:366

Article

Li, Dawei^1,2  Wang, Yikai²  Hu, Jiazhi²  Lu, Bo¹  Cheng, Yang-Tse²  Zhang, Junqian^3,4,5 

[1] Shanghai Univ, Shanghai Inst Appl Math & Mech, Shanghai 200072, Peoples R China

[2] Univ Kentucky, Dept Chem & Mat Engn, Lexington, KY 40506 USA

[3] Shanghai Univ, Dept Mech, Shanghai 200444, Peoples R China

[4] Shanghai Key Lab Mech Energy Engn, Shanghai 200072, Peoples R China

[5] Shanghai Univ, Mat Genome Inst, Shanghai 200444, Peoples R China

关键词: Lithium-ion battery;    Silicon composite electrode;    In situ measurement;    Fracture;    Modulus;    Diffusion induced stress;   

DOI  :  10.1016/j.jpowsour.2017.09.004

来源: Elsevier

【 摘 要 】

Mechanical properties and lithiation-induced stress are crucial to the performance and durability of lithium-ion batteries. Here, we report the evolution of elastic modulus and stress in a silicon/polyvinylidene fluoride (PVDF) composite electrode coated on a copper foil, along with a model for analyzing the large change in the radius of curvature of the composite electrode/copper foil cantilever. The radius of curvature of the cantilever is captured by a video camera during lithiation/delithiation. The elastic modulus of the composite electrode decreases from about 0.64 GPa to 0.18 GPa during lithiation. It decreases further to about 0.10 GPa after delithiation, which is caused by the fracture of the electrode. The magnitude of the compressive stress increases lineally during lithiation and decreases suddenly to reach a steady state value during delithiation. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

Free