Electrochemical Generation and Measurement of Sulfide Ion in Molten LiCl-KCl Eutectic

Abstract

An electrode composed of the eutectic mixture of nickel sulfide and nickel (1:1 mole ratio) has been shown to be useful for coulometrically generating sulfide ion (S−2) in molten lithium chloride‐potassium chloride eutectic. A shiny nickel electrode coated with nickel sulfide functions reversibly as an electrode of the second kind for sulfide ion. With this indicator electrode, the solubility product of nickel sulfide in the temperature range 375°–475°C has been determined, and the heat of reaction for the solubility equilibrium has been calculated. The solubility behavior of lithium sulfide in the same temperature range has also been investigated.