1,2-Dimethyl-3-octyl-1H-imidazolium salt with 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide;bis(trifluoromethylsulfonyl)azanide;1,2-dimethyl-3-octylimidazol-1-ium
1-Alkyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide ionic liquids as highly safe electrolyte for Li/LiFePO4 battery
摘要:
Several 1-alkyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide ionic liquids (alkyl-DMimTFSI) were prepared by changing carbon chain lengths and configuration of the alkyl group, and their electrochemical properties and compatibility with Li/LiFePO4 battery electrodes were investigated in detail. Experiments indicated the type of ionic liquid has a wide electrochemical window (-0.16 to 5.2V vs. Li+/Li) and are theoretically feasible as an electrolyte for batteries with metallic lithium as anode. Addition of vinylene carbonate (VC) improves the compatibility of alkyl-DMimTFSI-based electrolytes towards lithium anode and LiFePO4 cathode, and enhanced the formation of solid electrolyte interface to protect lithium anodes from corrosion. The electrochemical properties of the ionic liquids obviously depend on carbon chain length and configuration of the alkyl, including ionic conductivity, viscosity, and charge/discharge capacity etc. Among five alkyl-DMimTFSI-LiTFSI-VC electrolytes. Li/LiFePO4 battery with the electrolyte-based on amyl-DMimTESI shows best charge/discharge capacity and reversibility due to relatively high conductivity and low viscosity, its initial discharge capacity is about 152.6 mAh g(-1), which the value is near to theoretical specific capacity (170 mAh g(-1)). Although the battery with electrolyte-based isooctyl-DMimTFSI has lowest initial discharge capacity (8.1 mAh g(-1)) due to relatively poor conductivity and high viscosity, the value will be dramatically added to 129.6 mAh g(-1) when 10% propylene carbonate was introduced into the ternary electrolyte as diluent. These results clearly indicates this type of ionic liquids have fine application prospect for lithium batteries as highly safety electrolytes in the future. (C) 2010 Elsevier Ltd. All rights reserved.
Effect of Hydroxyl Groups in a Cation Structure on the Properties of Ionic Liquids
作者:V. G. Krasovskiy、E. A. Chernikova、L. M. Glukhov、G. I. Kapustin、A. A. Koroteev
DOI:10.1134/s0036024418120245
日期:2018.12
which differ by the presence of a hydroxylgroup at the ω-position of the alkyl substituent in the cation structure (nC = 2–8). The properties of the liquids were studied by DSC, TGA, and IR and NMR spectroscopy. Their thermal stability was studied, and the melting points, viscosity, and volatility in vacuum were measured. The effect of OH groups in the structure of the ionic liquid on its properties
合成了带有双(三氟甲基磺酰基)酰亚胺阴离子的两个咪唑鎓离子液体,它们的区别在于阳离子结构中烷基取代基的ω-位置存在羟基(n C = 2-8)。通过DSC,TGA,IR和NMR光谱研究了液体的性质。研究了它们的热稳定性,并测量了熔点,粘度和真空挥发度。评估了离子液体结构中的OH基团对其性能的影响。