Inelastic shape changes of silicon particles and stress evolution at binder/particle interface in a composite electrode during lithiation/delithiation cycling

Document Type

Article

Publication Date

12-1-2016

Abstract

Inelastic shape changes of Si particles and stress evolution at binder/particle interface was modeled using coupled diffusion–stress framework available in finite element software. A simple model that contains two spherical Si particles with and without the polymer binder film was used to represent the composite electrode. The particles were lithiated and delithiated at two different rates: one representing a slow charging case which results in a uniform Li concentration throughout the Si particles and the other representing a fast charging condition which results in non-uniform lithium concentration within the spherical Si particles. The inelastic shape changes and associated contact forces predicted by the model are qualitatively consistent with experimental data. Further, the effect of binder mechanical properties and the binder fraction on the stress evolution in Si particles and at the binder/particle interface was calculated. The proposed model, although simple, can guide a battery design engineer to choose a proper binder, charge/discharge strategy, and binder fraction for a durable electrode design.

Identifier

84962037334 (Scopus)

Publication Title

Extreme Mechanics Letters

External Full Text Location

https://doi.org/10.1016/j.eml.2016.03.020

e-ISSN

23524316

First Page

430

Last Page

438

Volume

9

Grant

DE-SC0007074

Fund Ref

National Science Foundation

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