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Yongsheng Hu

Publications and source records attributed to Yongsheng Hu.

3 recordsLinked to original sources

Spectroscopic studies on the cation-anion, cation-solvent and anion-solvent interactions in the LiCF3SO3/acetamide complex system.

A molten salt electrolyte composed of lithium triflate (LiCF3SO3) and acetamide (CH3CONH2) has been prepared and characterized by Raman, IR spectroscopy and ac impedance. It is found that acetamide molecule not only complexes with the Li+ cation but also interacts with the CF3SO3- anion via hydrogen bonding due to its two polar groups (C=O group and NH2 group) capable of coordinating with cations and anions, respectively. Cation-anion interaction is strengthened while cation-solvent and anion-solvent interactions are weakened with the increases of salt concentration and temperature in the LiCF3SO3/acetamide complex. The ionic conductivities of the LiCF3SO3/acetamide complex with different molar ratios depend strongly on the ionic association in the complex system.

Acetamides↗

Spectroscopic and DFT studies to understand the liquid formation mechanism in the LiTFSI/acetamide complex system.

It is interesting that although both lithium bis(trifluoromethane sulfone) imide (LiN(SO2CF3)2, LiTFSI) and acetamide (CH3CONH2) are solid, their mixture is a liquid in an appropriate molar ratio range at room temperature. The liquid formation mechanism of the LiTFSI/acetamide complex has been investigated by FT-IR and FT-Raman spectroscopy. The spectroscopic studies show that the Li+ ions coordinate with the C=O group of acetamide whereas the SO2 group in TFSI- anions interacts with the NH2 group of acetamide via hydrogen bonding. These interactions lead to the breakage of the hydrogen bonds between acetamide molecules and to the dissociation of LiTFSI, resulting in the formation of this molten salt. Furthermore, it has been found that moderate interaction between LiX and RCONH2 (R = -NH2, -CH3 and -CF3) is favorable for forming a LiX/RCONH2 molten salt system with low eutectic temperature and high conductivity based on density functional theory (DFT) calculational and experimental comparison for different R groups in RCONH2 and different lithium salts.

Acetamides↗