查看文章

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 …