Density functional theory (DFT) is used in conjunction with experimental results to propose decomposition pathways that describe the role and ultimate fate of the PES additive in Li-ion batteries. Oxidation of PES produces carbonyl sulfide gas and ethene at the positive electrode, both experimentally observed byproducts. However, the calculated standard potential for simple PES oxidation, ${E^0}_{ox}$ ∼ 6.7 V vs. Li/Li⁺, is quite high, suggesting this pathway is unlikely. A “reactive electrode model” is presented, in which the positive electrode material is a reagent in the pseudo-combustion of PES (and other solvents). This spontaneous process produces carbonyl sulfide, carbon dioxide, and a rock salt surface layer, all of which are experimentally observed. At the negative electrode, the reduction of PES occurs via two one-electron steps, where ${E^0}_{red,1}$ = 0.9 V and ${E^0}_{red,2}$ = 4.3 V. The reduced species, Li₂PES, can react with hydrogen and methyl radicals to produce propene, methylpropene, propane and lithium sulfite. Nucleophilic Li₂PES can also react with electrophilic PES, ethylene carbonate, or ethyl methyl carbonate. Eighteen possible organic sulphate ‘building blocks’ for the solid-electrolyte interphase (SEI) are presented. X-ray photoelectron spectroscopy (XPS) measurements demonstrate that PES reduction indeed results in both lithium sulfite and organic sulphate SEI components.

密度泛函理论（DFT）与实验结果结合使用，提出了描述PES添加剂在锂离子电池中的作用和最终命运的分解途径。PES的氧化会在正极产生羰基硫化物气体和乙烯，这都是实验观察到的副产物。但是，计算得出的简单PES氧化的标准电势，${E^0}_{ØX}$ 相对于Li / Li ^+的6.7 V相对较高，表明这种途径不太可能。提出了“反应电极模型”，其中，正极材料是PES（和其他溶剂）假燃烧中的试剂。该自发过程产生了羰基硫，二氧化碳和岩盐表面层，所有这些均通过实验观察到。在负极，PES的还原通过两个单电子步骤进行，其中${E^0}_{\mathrm{[R}Ëd，\mathrm{1个}}$ = 0.9 V且 ${E^0}_{\mathrm{[R}Ëd，\mathrm{2个}}$ = 4.3V。还原的物质Li ₂ PES可与氢和甲基自由基反应生成丙烯，甲基丙烯，丙烷和亚硫酸锂。亲核性Li ₂ PES也可以与亲电性PES，碳酸亚乙酯或碳酸乙基甲酯反应。提出了十八种可能用于固体电解质相间（SEI）的有机硫酸盐“结构单元”。X射线光电子能谱（XPS）测量表明，PES还原确实导致亚硫酸锂和有机硫酸盐SEI组分。