New electrolytes are needed to replace commercial carbonate electrolytes to enable a wider working temperature range, higher energy density, and faster charging of lithium-ion batteries (LIBs). Fluorinated diluents and solvents have shown promise in LIB electrolyte design, but most of them are considered per- and polyfluoroalkyl substances (PFAS) with significant environmental and health concerns. In this work, we design a family of non-PFAS, partially fluorinated ether solvents for LIB electrolytes. Through rational molecular design, an optimized rate capability is achieved by low viscosity, weak lithium-ion solvation, and high ion diffusivity. The optimized electrolytes enable a longer cycle life and better rate capability (up to 6 C) than previously reported fluorinated ethers or commercial carbonate electrolyte in graphite/LiNi_0.8Mn_0.1Co_0.1O₂ (Gr/NMC811) full cells. In addition, they also show an extended working temperature window with stable long-term cycling from 60 to −40 °C. This work shows a promising path to next generation batteries capable of extreme conditions without introducing PFAS concerns.

中文翻译：

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全温快充锂离子电池氟醚电解质分子结构优化


需要新的电解质来取代商用碳酸盐电解质，以实现更宽的工作温度范围、更高的能量密度和更快的锂离子电池 （LIB） 充电。含氟稀释剂和溶剂在 LIB 电解液设计中显示出前景，但它们中的大多数被认为是全氟烷基和多氟烷基物质 （PFAS），具有重大的环境和健康问题。在这项工作中，我们设计了一系列用于 LIB 电解质的非 PFAS、部分氟化醚溶剂。通过合理的分子设计，通过低粘度、弱锂离子溶剂化和高离子扩散率实现了优化的速率能力。与以前报道的石墨/LiNi_0.8Mn_0.1Co_0.1O₂ （Gr/NMC811） 全电池中的氟化醚或商用碳酸盐电解质相比，优化的电解质具有更长的循环寿命和更好的倍率能力（高达 6 C）。此外，它们还显示出扩展的工作温度窗口，可在 60 °C 至 −40 °C 范围内保持稳定的长期循环。 这项工作为能够在极端条件下运行而不会引入 PFAS 问题的新型电池指明了一条前景广阔的道路。