Mechanical analysis of the delamination of artificial solid electrolyte interface in lithium-ion batteries

Abstract

An artificial solid electrolyte interface (SEI) layer is able to provide mechanical force to constrain or suppress the undesirable growth of dendrite in lithium-ion batteries. This paper performs an axis-symmetrical mechanical analysis to investigate the delamination behavior of artificial SEI layer on the surface of the anode electrode due to dendrite growth. The adhesion force between the SEI layer and the electrode is modeled by using the exponential and the bi-linear traction-separation laws (TSLs), in which the maximum stress and its peak position can be varied. With all of the given TSL profiles, the suppression force of the artificial SEI layer exerted on the dendrite is shown to present a simple relation with the final delamination radius. Further exploration on the change in the dendrite size and the SEI layer thickness demonstrates two findings regarding the relationships among the suppression force, the final delamination radius, the dendrite height, the dendrite radius, and the thickness of the artificial SEI layer.