Abstract: Ethanol methylimidazole bromide and ethoxy ehanol methylimidazole chloride were synthetized by the reaction of 1-methylimidazole with 2-(2-chloro-ethoxy)-ethanol and 2-bromoethanol, respectively. The structures were characterized using 1H HMR and FT-IR. The thermal performances of the products were examined by TG and DSC, and the electrochemical properties were also studied. The results show that the hydroxyl imidazole ionic liquid has an eminent thermal stability. The short-chain ionic liquid containing an ether bond and a hydroxyl is beneficial to improving the conductivity, and the conductive mechanism can be rationalized by the Vogel-Tmman-Fulcher(VTF) function. the ethanol methylimidazole bromide and ethoxy ethanol methylimidazole chloride have conductivities of 1.2×10-4 S/cm and 1.7×10-4 S/cm, respectively, at room temperature. For the system containing propylene carbonate, ethoxy ethanol methylimidazole chloride and potassium, the maxium conductivity can reach 3.82×10-3 S/cm. The electrochemical window of the ethoxy ethanol methylimidazole chloride is 3.4 V.

Key words: ionic liquids, polyethylene glycol, lithium ion battery, VTF function, electrochemical properties