Interface Structure in Li-Metal/[Pyr_(14)][TFSI]-Ionic Liquid System from Ab Initio Molecular Dynamics Simulations
Boris V. Merinov, Sergey V. Zybin, Saber Naserifar, Sergey Morozov, Julius Oppenheim, William A. Goddard III, Jinuk Lee, Jae Hyun Lee, Hyea Eun Han, Young Cheol Choi, Seung Ha Kim
Abstract
Ionic liquids (ILs) are promising materials for application in a new generation of Li batteries. They can be used as electrolyte or interlayer or incorporated into other materials. ILs have the ability to form a stable solid electrochemical interface (SEI), which plays an important role in protecting the Li-based electrode from oxidation and the electrolyte from extensive decomposition. Experimentally, it is hardly possible to elicit fine details of the SEI structure. To remedy this situation, we have performed a comprehensive computational study (density functional theory-based molecular dynamics) to determine the composition and structure of the SEI compact layer formed between the Li anode and [Pyr_(14)][TFSI] IL. We found that the [TFSI] anions quickly reacted with Li and decomposed, unlike the [Pyr_(14)] cations which remained stable. The obtained SEI compact layer structure is nonhomogeneous and consists of the atomized S, N, O, F, and C anions oxidized by Li atoms.
Group Members
Merinov, B. V., Zybin, S. V., Naserifar, S., Morozov, S., Oppenheim, J., III, W. A. G., Lee, J., Lee, J. H., Han, H. E., Choi, Y. C., & Kim, S. H. (2019). Interface Structure in Li-Metal/[Pyr_(14)][TFSI]-Ionic Liquid System from Ab Initio Molecular Dynamics Simulations. *J. Phys. Chem. Lett.*, *10*(16), 4577-4586. https://doi.org/10.1021/acs.jpclett.9b01515