Electrolytes with sparingly polysulfide solubility such as 1.5 M LiTFSI in tetramethylene sulfone (TMS) and 1,1,2,2‐tetrafluoroethyl‐2,2,3,3‐tetrafluoropropyl ether (TTE) are beneficial for the cycle stability of Li−S pouch cells. In this work, this specific electrolyte system and the role of dissolved polysulfides (PS) in symmetrical Li/Li cells is investigated. By studying varying TMS/TTE volume ratios and polysulfide addition aided by both ex situ and operando spectroscopic as well as microscopic techniques, the positive impact of PS on the lithium plating/stripping behavior is evaluated. The composition of the solid‐electrolyte interphase (SEI) as well as the microscopic morphology differs for electrolytes with PS from those without PS addition. These findings are crucial for the development of electrolytes for cycle‐stable Li−S prototype cells.

中文翻译：

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少量硫化溶剂中多硫化物对锂金属阳极的稳定作用

具有少量多硫化物溶解性的电解质，例如1.5M LiTFSI在四亚甲基砜（TMS）和1,1,2,2-四氟乙基-2,2,3,3-四氟丙基醚（TTE）中的溶解度对Li-S的循环稳定性有好处袋状细胞。在这项工作中，研究了这种特定的电解质体系以及溶解的多硫化物（PS）在对称Li / Li电池中的作用。通过研究由两个辅助改变TMS / TTE体积比和多硫化物此外易地和operando在光谱学和微观技术上，评估了PS对锂电镀/剥离行为的积极影响。含PS的电解质与不添加PS的电解质的固体电解质中间相（SEI）的组成以及微观形态是不同的。这些发现对于周期稳定的LiS原型电池电解质的开发至关重要。