Electrolyte engineering plays a critical role in enabling lithium (Li) metal batteries. However, the simultaneous realization of anion-rich solvation structure and high ionic conductivity of electrolytes via solvation structure design remains challenging. Here, we report a low-cost, non-fluorinated electrolyte with a micelle-like solvation structure by introducing amphiphilic n-butyl methyl ether (MNBE) into Li bis(fluorosulfonyl)imide (LiFSI)/1,2-dimethoxyethane (DME) for stable Li metal batteries (LMBs). MNBE can effectively promote Li⁺-FSI⁻ coordination through steric crowding. Meanwhile, the inert alkyl chains of MNBE can mitigate the reaction between electrolyte and Li metal due to their lithiophobicity. Specifically, the micelle-like, non-fluorinated electrolyte exhibits an ionic conductivity as high as 12.55 mS cm⁻¹, and its anion-rich solvation structure promotes the formation of LiF-rich solid-electrolyte interphase. We constructed a 7.3 Ah Li||NMC811 pouch cell employing this electrolyte under harsh conditions, exhibiting ultra-high specific energy of 503.7 Wh kg⁻¹ with impressive cycling stability of 84.1% capacity retention after 100 cycles.

中文翻译：

---

用于超高能量密度锂金属电池的具有胶束状溶剂化作用的无氟电解质


电解质工程在实现锂 （Li） 金属电池方面发挥着关键作用。然而，通过溶剂化结构设计同时实现富阴离子溶剂化结构和电解质的高离子电导率仍然具有挑战性。在这里，我们通过将两亲性正丁基甲基醚 （MNBE） 引入锂双（氟磺酰基）酰亚胺 （LiFSI）/1,2-二甲氧基乙烷 （DME） 中，报道了一种具有胶束状溶剂化结构的低成本、无氟电解质，用于稳定的锂金属电池 （LMB）。MNBE 可以通过空间拥挤有效促进 Li⁺-FSI⁻ 配位。同时，MNBE 的惰性烷基链由于其疏锂性而可以减轻电解质与锂金属之间的反应。具体来说，胶束状非氟化电解质表现出高达 12.55 mS ^cm-1 的离子电导率，其富含阴离子的溶剂化结构促进了富含 LiF 的固体电解质界面的形成。我们建造了一个 7.3 Ah Li||NMC811 软包电池在恶劣条件下使用这种电解质，表现出 503.7 Wh ^kg-1 的超高比能量，在 100 次循环后具有令人印象深刻的 84.1% 容量保持率。