High-voltage activation and dynamics of conductivity relaxation in a binary NaHSO4-KHSO4 system

Abstract

The effect of high-voltage pulses on the conductivity of the binary system of protonic solid NaHSO4-KHSO4 electrolyte and its melt with the NaHSO4 content of 25, 50, 75 mol % is studied. The conductivity of both the solid electrolyte and its melt grows at the increase in the electric field intensity and tends to saturation in the melt. The highest relative conductivity increase of molten electrolyte (T = 469 K, 25 mol % NaHSO4) reaches 296% and that of the solid electrolyte (T = 408 K, equimolar composition) before breakdown phenomena is 78%. The breakdown conductivity increases by several orders of magnitude. The conductivity relaxation processes after high-voltage pulsed discharges are studied. Relaxation times τ for nonequilibrium carriers are calculated that are of the order of 103 to 104 s. This time is lower for solid electrolytes, as compared to that in the corresponding melts.