Design of Thin-Film Interlayer between Silicon Electrode and Current Collector Using a Chemo-Mechanical Degradation Model

Abstract

To enhance delamination limitations in silicon electrode, a thin-film interlayer between silicon electrode and copper current collector is designed using a chemo-mechanical degradation model. The chemo-mechanical degradation model considers the formation of the solid electrolyte interphase on the surface and within the cracks of the silicon electrode, the physical isolation of active materials and the resistance due to loss of contact between the silicon composite electrode and the copper foil as the main capacity fading mechanisms. The model is validated with experimental data collected from coin cells made of silicon electrode with a bare and an adhesive thin film laminated copper foil. The reduction in the delamination limitations depends on the interplay of the adhesion strength, conductivity, coverage and thickness of adhesive thin film on the surface of the copper foil.