Fluoroethylene Carbonate (FEC) is an effective electrolyte additive which can significantly improve the cyclability of Si and other anode materials. However, the fundamental mechanism on this improvement is still not well understood. Based on the results obtained from 6Li Nuclear Magnetic Resonance and X-ray Photoelectron Scanning study, we propose a molecular level mechanism on how FEC affects the formation of solid electrolyte interphase (SEI) film: 1) FEC is reduced through the opening of the five member ring leading to the formation of lithium poly (vinyl carbonate), LiF and some dimmers; 2) The high tensile strength of the FEC-derived lithium poly (vinyl carbonate) enhances the stability of the SEI film. This mechanism has been verified by the results of electrochemical tests.
Revised: July 16, 2020 |
Published: February 1, 2014
Citation
Chen X., X. Li, D. Mei, J. Feng, M.Y. Hu, J.Z. Hu, and M.H. Engelhard, et al. 2014.Reduction Mechanism of Fluoroethylene Carbonate for Stable Solid–Electrolyte Interphase Film on Silicon Anode.ChemSusChem 7, no. 2:549-554.PNNL-SA-97198.doi:10.1002/cssc.201300770