Constrasting Conductance/Viscosity Relations in Liquid States of Vitreous and Polymer Solid Electrolytes

摘要

In order to contrast conductivity mechanisms in fast ion glassy and rubbery polymer electrolytes, the liquid states of two prototypical cases have been studied. Viscosity and conductivity measurements have been performed on molten (as opposed to glassy) (AgCl) 0.35 (Ag(I)) 0.45 (CsCl) 0.20 and on solutions of sodium triflate in low molecular weight PPG (as opposed to high mw, 1,000,000 rubbery solid PPG - called PPO). Both types of system show non-Arrhenius viscosity with divergent behavior near T(g). The energetics of the conductivity processes, however, are very different. This is emphasized by reduced temperature scale (T/T(g)) plotting of (temperature-dependent) activation energies. For the polymer salt systems, as for normal molten salt systems and aqueous solutions, conductance and viscosity energetics are comparable - the processes are coupled. Reduced temperature plots of polymer solutions and glassforming aqueous solution data show the relative importance of T(g) and ion association factors in limiting polymer electrolyte performance.