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

Abstract

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.

Electrochemical Behaviors and Extraction of Ln(III) (Ln = La, Ce, Nd) Ions in LiCl–KCl–CsCl Eutectic Salts at Low Temperatures

“…CV and SWV measurements were first applied to study the electrochemical behavior of Ln­(III) in the range of 563–683 K. As displayed in Figure , the redox behaviors of La­(III), Ce­(III), and Nd­(III) in the melt were recorded at 683 K. Here, the CV curves of La­(III) are consistent with the behavior in LiCl–KCl, and there is only one redox pair 4c/4a at −2.18/–1.97 V in Figures a and S1, which should be attributed to the deposition and dissolution of lanthanum metal. − Similarly, in the corresponding SWV curve (in Figure b), it can be found that peak 4c at −2.15 V was caused by the deposition of the La metal …”

Experimental Studies of Lanthanides Electro-Codeposition in Molten Salt to Evaluate a 1-D Electrorefining Computer Model

“…In general, experimental studies investigating the behaviors of elements in a molten salt are conducted in a small-scale electrochemical cell. [19][20][21][22][23][24][25][26][27][28][29][30][31][32] However, in this study, the experiment cell was designed to be large enough (∼250 cm 3 ) to allow dendrite growth, thereby facilitating the study of the mass transfer phenomena in the cell. The experiment setup is as follows.…”

Electrochemical behaviors of Li–B alloys in a LiCl–LiBr–KBr molten salt system

“…the open circuit potential, charge transfer coefficient and exchange current density, play an important role in evaluating the electrochemical behaviors. 10,11 Specifically, the open circuit potential in relation to the Gibbs free energy can affect the energy density of power sources. The charge transfer coefficient is a kinetic parameter relating how the applied potential promotes one direction of a reaction over the other.…”