A Comparison of Standard SEI Growth Models in the Context of Battery Formation

This paper compares standard SEI growth models in lithium-ion batteries during formation cycles.

This paper compares standard SEI growth models in lithium-ion batteries during formation cycles. I categorise zero-dimensional models into solvent-limited (reaction-diffusion, diffusion-limited, reaction-limited) and electron-limited (electron migration, interstitial diffusion, electron tunneling, and Von Kolzenberg) types. The analysis shows that while these models predict higher SEI growth in the first cycle compared to subsequent ones, they fail to capture the experimental observation that first-cycle capacity fade is two orders of magnitude higher than later cycles.

Qualitative comparison with experimental coulombic efficiency data from coin cells at low C-rates confirms this limitation. This suggests new models are needed to accurately describe formation cycle physics, as current approaches derived for long-term degradation are inadequate for the unique processes occurring during initial SEI formation. Better understanding these mechanisms could optimize formation protocols and reduce manufacturing costs.