A homologous series of deep eutectic electrolytes based on lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was investigated by molecular dynamics (MD) simulations [1]. Forces and energies were ontained by the local equivariant neural network interatomic potential Allegro [2]. The accuracy at the level of density functional theory is essential for Li-Li-contacts of about 2.9 Å which are nearly absent in classical force field simulations. The unexpected structure of the liquid is facilitated by the oxygen atoms of the urea derivates resulting in a coupled rocking motion of neighbored Li-atoms. The Li-diffusion is affected by this structural motive as well changing from a solvent exchange to a vehicular Li-transport mechanism within the studied homologous series.

[1] O. Shayestehpour, S. Zahn, J. Chem Phys., 2024, 161, 134505
[2] A. Musaelian et al., Nat. Commun., 2023, 14, 579