Conductivity, Viscosity, and Their Correlation of a Super Concentrated Aqueous Electrolyte

A super-concentrated aqueous electrolyte, "water-in-bisalt (WiBS)", consisting of 21 m lithium bis(trifluoromethanesulfonyl)imide and 7 m lithium trifluoromethanesulfonate on the most concentrated end, was measured for its electrolytic conductivity k and glass transition temperature T-g in wide ranges of salt concentration m and temperature 0, with Tg as an indicator for the electrolyte viscosity. The measured K-(m, theta) data in its entirety was fitted with an extended Casteel-Amis equation for an accurate functional representation, and the k-theta data for the most concentrated electrolytes were fitted with the Vogel-Fulcher-Tammann equation for an evaluation of the activation energy Ea and vanishing mobility temperature To. The resultant values of K. and T-0 are compared and correlated with T-g, and the possibility of the formation of a water salt liquid structure under these super-concentrated environments is discussed.