The Reductive Mechanism of Prop-1-ene-1,3-sultone as Solid Electrolyte Interphase Film-forming Additive for Lithium Ion Battery

The mechanism for the reduction of Prop-1-ene-1,3-sultone (PES) on anode of lithium ion battery is understood by theoretical calculation at the B3LYP/6-311++G (d, p) level of density functional theory with the polarized continuum models (PCM). It is found that PES in solvent is reduced prior to PC to form PES+e by the obtained frontier molecular orbital energy and electron affinity. The structure of PES+e is unstable, and prone to a spontaneous rearrangement to form PES-1 or PES-2 by the breaking of C1-O2 or O2-S7. The transition state (TS) is optimized and confirmed by vibrational frequency analysis and intrinsic reaction coordinate (IRC) method. The bond orders and atomic charge distribution of the stable points along the minimum energy path (MEP) are analyzed using the natural bond orbital (NBO) method at the B3LYP/6-311++G (d, p) level of DFT. The negative charge is mostly distribution on -SO2 group in PES+e, based on the structures, bond order and Charge distribution analyses, and it is known that PES+e experiences the breaking of C1-O2 or O2-S7 to form a stable open cyclic anion radical (PES-1 or PES-2).