Comparison of thermophysical properties of pure imidazolium nitrate and doped with a lithium nitrate salt in liquid and gel forms as potential electrolytes.

Current electrolytes for electrochemical energy storage devices are made of solvent which often present problems of flammability, corrosion and high toxicity. Ionic liquids and mixtures with metal salts are proposed as a good selection for more safety electrolytes due to their properties as, among others, non-flammability, negligible vapour pressure, high ionic conductivity and wide electrochemical window.

In this work, electrical conductivity of solutions of the ionic liquid 1-Ethyl-3-methylimidazolium nitrate ([EIm][NO₃]) with lithium nitrate salt in four different concentrations has been analysed, for liquid and gel states.

Temperature and salt concentration dependences of electrical conductivity have been studied for liquid and gel states. As expected, an increase of conductivity with temperature and a decrease whit salt concentration were observed, except for the case of gel [EIm][NO₃] with salt concentration of 0.5 m which shows a little increase of conductivity compared to the pure gel.

Comparison of conductivity of the liquid and gel states shows a significant increase for gel state at low concentrations of the added salt.