Heterogeneity of solid electrolyte interphase layer sensitively determines thermo-chemo-mechanical stresses in a silicon anode particle

Abstract

A significant amount of work has been carried out to study the effect of temperature at the battery level. However, its effect at the particle level has not been investigated extensively. Further, the effect of heterogeneity of solid electrolyte interphase (SEI) layer is not given much attention. It is decisive in the stability of the SEI layer. Motivated by these facts, to study the effect of heterogeneity of SEI layer along with temperature on chemo-mechanical stresses within a silicon anode particle, a mathematical model is developed based on the finite deformation theory, together with the incorporation of plasticity. The effect of temperature on the stresses, with and without heterogeneous SEI layer, is also discussed. The heterogeneity of the SEI layer significantly alters the stresses in the inorganic part of the SEI layer as compared to the homogeneous assumption of the SEI layer. Additionally, the impact of various parameters on peak hoop stress found in the SEI layer is also investigated. The radial and hoop stresses in the particle without SEI layer considering temperature variation are found to be less as compared to without considering temperature variation. This study can help in identifying important properties for designing a superior artificial SEI for the better performance of Li-ion batteries. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.