In this study, 3-(2,2,2-trifluoroethoxy)-propionitrile (FEON), a fluorinated nitrile compound with high oxidative stability, low volatility and non-flammability, is introduced as an electrolyte solvent for high-energy density Li|NCM batteries. After optimization of the electrolyte as (0.8 M LiTFSI + 0.2 M LiODFB)/FEC : FEON (1 : 3, by vol., abbreviated as FF13), the FEON-based electrolyte exhibits better cycling performance for both the lithium metal anode and 4.4 V high-voltage NCM cathode, compared with those of a commercial carbonate electrolyte of 1 M LiPF₆/EC : EMC : DMC (1 : 1 : 1, by vol.). As for the FF13 electrolyte, the maximum coordination number of 3 for FEON molecules in the solvation structure is disclosed through molecular dynamics simulation combined with Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy measurements. Furthermore, the solid electrolyte interphase on the lithium metal anode is enriched with organic components and LiF, which is proposed from FEON decomposition based on density functional theory calculations and X-ray photoelectron spectroscopy analysis. All the above results demonstrate that fluorinated nitrile electrolytes constitute a promising platform for high energy density Li|NCM batteries.

中文翻译：

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用于高能量密度锂金属电池的 3-(2,2,2-三氟乙氧基)丙腈基电解质

在这项研究中，3-(2,2,2-三氟乙氧基)-丙腈 (FEON) 是一种具有高氧化稳定性、低挥发性和不易燃性的氟化腈化合物，被引入作为高能量密度 Li| 的电解质溶剂。三元电池。将电解液优化为(0.8 M LiTFSI + 0.2 M LiODFB)/FEC : FEON (1 : 3, by vol., 缩写为FF13)后，基于FEON的电解液对锂金属负极和4.4 V 高压 NCM 阴极，与 1 M LiPF _{6的商用碳酸盐电解质相比}/EC : EMC : DMC（1 : 1 : 1，按体积计）。对于FF13电解质，通过分子动力学模拟结合傅里叶变换红外光谱和核磁共振光谱测量，揭示了溶剂化结构中FEON分子的最大配位数为3。此外，锂金属负极上的固体电解质界面富含有机成分和 LiF，这是基于密度泛函理论计算和 X 射线光电子能谱分析的 FEON 分解提出的。所有上述结果表明，氟化腈电解质构成了高能量密度 Li|NCM 电池的有前途的平台。