Modeling the SEI layer formation and its growth in lithium-ion batteries (LiB) during charge-discharge cycling

A numerical model is developed to analyse the effect of solid electrolyte interphase (SEI layer) formation and SEI layer growth in a Li-ion battery (LiB) under charge-discharge load cycling in COMSOL 5.3a software. The solvent (ethylene carbonate) reaction at the negative electrode/SEI interface leads to lithium carbonate (Li2CO3) formation as an SEI film product. In this paper, SEI film thickness formed on the anode and its growth is studied with respect to the number of cycles and time for various dependent parameters such as C rate, cell voltage, anode particle size, and reaction rate constant. The resistance offered by SEI film and overpotential is also computed in this model. The model predicts that the anode overpotential increases with increasing cycle number but levels off after a certain cycle number. Model results are compared with experimental data and are found to compare well.

Automated summary

The effect of solid electrolyte interphase (SEI layer) formation and growth in a Li-ion battery (LiB) has been analyzed using a numerical model. The model considers various parameters such as cycle number, time, C rate, cell voltage, anode particle size, and reaction rate constant. The results are compared with experimental data and show good agreement.