Abstract Composite materials based on ionic liquids (ILs) / poly(vinylidene fluoride) (PVDF) and their copolymers have emerged as an interesting approach to develop high ionic conductivity solid polymer electrolytes (SPEs) for lithium-ion battery application. This work reports the development of SPEs based on fluoropolymers, PVDF and poly(vinylidene fluoride co-hexafluoropropylene), PVDF-HFP, containing different ILs: 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([EMIM][TFSI]) and 1-butyl-3-methylimidazolium thiocyanate ([BMIM][SCN]). The influence of IL type and content on the morphological, wettability, physical-chemical, thermal, mechanical and electrochemical properties were evaluated. It is shown that, independently of the polymer matrix, both ILs improve surface wettability and increase the polar β phase content and crystallinity degree of the polymers. The mechanical properties show that the incorporation of IL in the composites results in a plasticizing behaviour. Further, the [BMIM][SCN]/PVDF-HFP with 40 wt% IL content shows the best room temperature ionic conductivity of 0.15 mS.cm−1 with excellent electrochemical stability in the 0.0–5.0 V potential window. The initial discharge capacity value at C/8-rate is 148 mAh.g−1 and 124 mAh.g−1 for the [BMIM][SCN]/PVDF and [BMIM][SCN]/PVDF-HFP composites, respectively, with high coulombic efficiency (98%). At C/8-rate, batteries with [BMIM][SCN]/PVDF-HFP show the lowest capacity fade (16% after 50 cycles) of the prepared composites. Thus, it is demonstrated the suitability of developing SPEs based on IL and fluorinated polymers for the next generation of solid-state room temperature lithium-ion batteries.

中文翻译：

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用于锂离子电池的基于离子液体的含氟聚合物固体电解质

摘要 基于离子液体 (IL) / 聚偏二氟乙烯 (PVDF) 及其共聚物的复合材料已成为开发用于锂离子电池应用的高离子电导率固体聚合物电解质 (SPE) 的有趣方法。这项工作报告了基于含氟聚合物、PVDF 和聚（偏二氟乙烯共六氟丙烯）、PVDF-HFP 的 SPE 的开发，其中包含不同的 IL：1-乙基-3-甲基咪唑鎓双（三氟甲基磺酰基）酰亚胺（[EMIM][TFSI]）和 1-丁基-3-甲基咪唑鎓硫氰酸盐 ([BMIM][SCN])。评价了IL类型和含量对形态、润湿性、物理化学、热、机械和电化学性能的影响。结果表明，与聚合物基体无关，两种离子液体都提高了聚合物的表面润湿性并增加了极性β相含量和结晶度。机械性能表明，在复合材料中加入 IL 会导致增塑行为。此外，具有 40 wt% IL 含量的 [BMIM][SCN]/PVDF-HFP 在 0.0-5.0 V 电位窗口中显示出最佳的室温离子电导率为 0.15 mS.cm-1，具有优异的电化学稳定性。[BMIM][SCN]/PVDF和[BMIM][SCN]/PVDF-HFP复合材料在C/8倍率下的初始放电容量值分别为148 mAh.g-1和124 mAh.g-1，库仑效率高（98%）。在 C/8 倍率下，具有 [BMIM][SCN]/PVDF-HFP 的电池显示出所制备复合材料的最低容量衰减（50 次循环后为 16%）。因此，