Physicochemical and Electrochemical Properties of Novel Ionic Liquids Containing Aprotic Heterocyclic Anions Doped With Lithium Salts

摘要

A series of novel ionic liquids (ILs) based on N, N'-dialkylimidazolium, tetra-alkylphosphonium, and di-alkylpyrrolidinium cations paired with two aprotic heterocyclic anions (AHAs) were synthesized in the present study. In addition, lithium salts of the corresponding anions were prepared. Physicochemical and electrochemical properties of the neat ILs and their mixtures with the lithium salts at various concentrations were systematically measured from 283.15K to 343.15K at atmospheric pressure, including density (ρ), viscosity (η), and electrical conductivity (σ). The empirical Vogel-Fulcher-Tammann (VFT) was used to analyze the experimental viscosities and electrochemical conductivities. Furthermore, the Walden plot behavior of the pure ILs and ILs doped with lithium salts were investigated. The results provide some insight into the strength of the association between Li~+ and the different anions. Consequently, the ILs with low viscosity and good conductivities are promising electrolytes candidates to be used in electrochemical applications.