Keywords

reference electrode, molten salt electrochemistry, metal chlorides, metal oxides, saturated redox potential, stability

Abstract

Stable and reproducible reference electrodes (REs) are essential for electrochemical systems operating in high-temperature molten salts, where consistent control of potential is required. This study uses three different solutes to investigate the development and evaluation of REs in eutectic LiCl-KCl at 773 K. The solutes tested were NiCl2, AgCl, and NiO, each prepared at multiple concentrations to assess stability, reproducibility, and saturation. Electrochemical stability was measured over three days using chronopotentiometry (CP), followed by open circuit potential (OCP), with cyclic voltammetry (CV) also integrated to monitor changes in electrochemical behavior over time. The CP-OCP approach established a Li+/Li redox potential, and CV was used to confirm the consistency of RE performance. REs containing NiCl2 showed stable behavior at all concentrations, with saturation achieved at 15 mol% or greater. NiO-based REs also showed both stability and saturation at all concentrations tested, which can be attributed to the low solubility of NiO in LiCl-KCl. AgCl-based REs were stable at low concentrations but exhibited potential drift at 5 mol% after 35–40 h. These findings support the use of NiCl2 and NiO above saturated concentrations for constructing reliable REs for future high-temperature electrochemical applications.

Original Publication Citation

Carlos Mejia, Devin Rappleye, Investigation of a stable and saturated reference electrode using metal chlorides and oxides in eutectic LiCl-KCl molten salts, Nuclear Engineering and Technology, Volume 58, Issue 1, 2026, 103875, ISSN 1738-5733, https://doi.org/10.1016/j.net.2025.103875.

Document Type

Peer-Reviewed Article

Publication Date

2025-08-21

Publisher

Nuclear Engineering and Technology

Language

English

College

Ira A. Fulton College of Engineering

Department

Chemical Engineering

University Standing at Time of Publication

Assistant Professor

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