Microsecond-scale staircase voltammetry for measuring the electrical conductivity of highly conductive liquids

Performing accurate electrical conductivity measurements in harsh environments (such as high temper-atures and corrosive conditions) or highly conductive liquids, which exhibit significant polarization, remains challenging. Thus, a rapid, simple technique involving two-electrode capillary cells and microsecond-scale staircase voltammetry was devised to effectively determine the electrical conductiv-ities of highly conductive liquids and high-temperature molten salts. The maximum currents generated in response to the voltage applied on a short microsecond timescale were free from polarization-induced interference. Thus, solution resistances were accurately determined from the slope of the simple, linear plot between the maximum peak current and applied voltage, and the electrical conductivities were determined using cell constants estimated using an aqueous 3 M KCl solution at room temperature. Validation was performed using a highly corrosive eutectic LiCl-KCl molten salt, whose conductivities in the temperature range of 657-915 K and conductivity range (1.1-2.5 S cm-1) were accurately known. Multiple steps of large-amplitude voltages facilitated measurements of liquids with a wide range of con-ductivities. Moreover, the measurements were performed within a few tens of microseconds, highlight-ing the potential of the method for real-time on-line monitoring of processes involving highly conductive molten salts.(c) 2022 Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chem-istry.