Charge Relaxation and Stokes–Einstein Relation in Diluted Electrolyte Solution of Propylene Carbonate and Lithium Perchlorate

Impedance spectroscopy was used for studies of electrical conductivity and electric charge relaxation in a diluted solution of propylene carbonate and lithium perchlorate (mole fraction x LiClO4 = 6 × 10–5) in the temperature range from 250 to 350 K. It was found that the viscosity behavior of the conductivity as well as the charge relaxation time related to the Li+ and ClO4 – ions immersed in propylene carbonate fulfill quite well the Stokes–Einstein hydrodynamic model. An essentially limited ion-pairing process in the studied solution of a low ion concentration and considerably limited dipolar aggregation of propylene carbonate molecules are considered to be essential factors determining the dynamic behavior of the ions immersed in that strongly polar liquid.