Examining the validity of Stoney-equation for in-situ stress measurements in thin film electrodes using a large-deformation finite-element procedure

JOURNAL OF POWER SOURCES

卷:387

Article

Wen, Jici¹  Wei, Yujie^1,3  Cheng, Yang-Tse² 

[1] Chinese Acad Sci, Inst Mech, LNM, State Key Lab Nonlinear Mech, Beijing 100190, Peoples R China

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

[3] Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China

关键词: Thin film electrode;    In-situ stress measurement;    Stoney equation;    Diffusion stress coupling;    Finite-deformation finite element;   

DOI  :  10.1016/j.jpowsour.2018.03.052

来源: Elsevier

【 摘 要 】

During the lithiation and delithiation of a thin film electrode, stress in the electrode is deduced from the curvature change of the film using the Stoney equation. The accuracy of such a measurement is conditioned on the assumptions that (a) the mechanical properties of the electrode remain unchanged during lithiation and (b) small deformation holds. Here, we demonstrate that the change in elastic properties can influence the measurement of the stress in thin film electrodes. We consider the coupling between diffusion and deformation during lithiation and delithiation of thin film electrodes and implement the constitutive behavior in a finite deformation finite element procedure. We demonstrate that both the variation in elastic properties in thin film electrodes and finite-deformation during lithiation and delithiation would challenge the applicability of the Stoney-equation for in-situ stress measurements of thin film electrodes.

【 授权许可】

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