Comparison of the Ionic Conductivity of Pure Imidazolium Nitrate and That Doped with a Lithium Nitrate Salt in Liquid and Gel Forms as Potential Electrolytes

Abstract

Current electrolytes for electrochemical energy storage devices are made of solvents, which often present problems of flammability, corrosion and high toxicity. Ionic liquids and mixtures with metal salts are proposed as a good selection for safer electrolytes due to their properties such as, among others, non-flammability, negligible vapor pressure, high ionic conductivity and wide electrochemical window. In this work, the electrical conductivity of solutions of the ionic liquid 1-ethyl-3-methylimidazolium nitrate ([EIm][NO3]) with lithium nitrate salt in three different concentrations is analyzed for liquid and gel states. The temperature and salt concentration dependences of electrical conductivity are studied for liquid and gel states. As expected, an increase in conductivity with temperature and a decrease with salt concentration were observed, except for the case of gel [EIm][NO3] with a salt concentration of 0.5 m, which shows a small increase in conductivity compared to the pure gel. Comparison of the conductivity of the liquid and gel states shows a significant increase for the gel state at low concentrations of the added salt.

Temperature-dependent anomalous viscosity of aqueous solutions of imidazolium-based ionic liquids

“…For an electrolyte solution, in general, the ionic conductivity increases with the increase in temperature because of enhanced mobility of the available free ions due to their higher thermal energy. 89 However, in the present case, the conductivity initially decreases and then increases with the temperature. This is an opposite trend from the behaviour of viscosity.…”

Pyrrolidinium Containing Ionic Liquid Electrolytes for Li-Based Batteries

“…This IL has shown compatibility with a wide range of cathode and anode materials in both its liquid [ 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 ] and polymer gel form [ 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 ]. Other imidazolium-based ILs have been synthesized and characterized, and their physicochemical properties were determined [ 108 , 109 , 110 ]. More recently, functionalized-imidazolium-based ILs are being investigated including phosphonate- [ 111 ], and Si-functionalized ILs [ 112 , 113 ].…”