Cyclic voltamperometry on platinum in LiCl-KCl and LiCl-KCl-Li2O melts

Mullabaev A.R., Kovrov V.A., Molchanova N.G., Zaikov Yu.P. 

ABSTRACT

Anode processes on platinum in 80LiCl-20KCl and 80LiCl-20KCl+Li₂O (mol. %) melts were investigated depending on the temperature by the methods of cyclic voltammetry and potentiostatic electrolysis. According to the experimental results obtained in the 80LiCl-20KCl (mol. %) melt, platinum begins to dissolve anodically with the formation of Pt²⁺ ions at the potentials of 3.14 and 3.04 V relative to Li⁺/Li at the temperatures of and 550°C  and 650°C, respectively. In 80LiCl-20KCl (mol. %) melt with the addition of Li₂O at the potentials of 2.40–2.43 V relative to Li⁺/Li, platinum oxidizes in two stages with the formation of Li₂PtO₃ at a rate of 4.96 mg/cm²·h. The rate of formation of Li₂PtO₃ and oxygen current efficiency at the potential of 2.8 V relative to Li⁺/Li and the temperature of 650°C are 23.5 mg/cm²·h and 96.15%, respectively. An increase in the temperature of the electrolyte leads to platinum corrosion losses.

KEY WORDS

oxide-halide melts, anodic processes, platinum anode, lithium chloride, lithium oxide

DOI: 10.31857/S0235010621060074