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 dialkylpyrrolidiniumcations paired with two aprotic heterocyclicanions (AHAs) were synthesized in the present study. In addition,lithium salts of the corresponding anions were prepared.Physicochemical and electrochemical properties of the neat ILsand their mixtures with the lithium salts at various concentrationswere systematically measured from 283.15K to 343.15K atatmospheric pressure, including density (ρ), viscosity (η), andelectrical conductivity (σ). The empirical Vogel-Fulcher-Tammann(VFT) was used to analyze the experimental viscosities andelectrochemical conductivities. Furthermore, the Walden plotbehavior of the pure ILs and ILs doped with lithium salts wereinvestigated. The results provide some insight into the strength ofthe association between Li~+ and the different anions. Consequently,the Ils with low viscosity and good conductivities are promisingelectrolytes candidates to be used in electrochemical applications.