关键词: 室温熔盐, 二(三氟甲基磺酸酰)亚胺锂, 乙酰胺, 非局部密度泛函, 红外光谱, 拉曼光谱

Abstract: New room-temperature molten salt based on lithium bis(trifluoro methane sucfone) imide(LiTFSI) and acetamide with a proper molar ratio has an excellent thermal stability and electrochemical performance. The action mechanism was studied by FTIR spectroscopy, FT-Raman spectroscopy and quantum chemistry calculation with nonlocal DFT. The vibrational spectra and calculated results show that acetamide can coordinate with Li⁺ cation in LiTFSI through Li—O bonding, and electrovalent bonding of LiTFSI was destroyed. A big coordinate cation formed and its positive charge was shielded in acetamide molecule. Charges of TFSI-ion were partly off resulting in to shielding of charges in the whole molecule by the terminal CF₃^- group. The coulombic forces was very weakly between the cations and anions, and the coordination of LiO can also cause the breakage of hydrogen bonding between acetamide molecules, resulting in the formation of this molten salt in the liquid state.

Key words: Room-temperature molten salt, LiTFSI, Acetamide, Nonlocal DFT, IR spectroscopy, Raman spectroscopy