Comparison of Exchange Current Density Acquisition Methods for LaCl3in Molten LiCl-KCl Eutectic Salt

The exchange current density values (i 0 ) of the La/La 3+ in LiCl-KCl eutectic salts at different temperatures (723–798 K) and concentrations (0.229–0.597 mol%) were measured by using cyclic voltammetry (CV), linear polarization (LP), and Tafel methods. The Tafel i 0 values had the largest relative error on an average of 27%, while the LP values, found at the same scan rates, had a lower relative error, ranging from 10–17%. The LP and Tafel results were found to be highly affected by an unstable surface area. The CV i 0 values were less affected by this issue due to higher scan rates, mainly 50–200 mV s −1 . The relative error of CV was the least among the three, averaging 6.5–11%. Linear correlations for i 0 versus temperature and concentration were developed from these results.