Availability Evaluation of SiC Anode in Chloride Molten Salt Electrolysis

Abstract

Carbon or graphite is commonly used to anode material in molten salt electrolysis, but they are consumed by a electrochemical reaction with a residual O2- in the bath. In this study, the dependence of anodic behavior in molten chloride containing O2- on some carbon materials with different structure has been investigated in LiCl-KCl-ClO melts at 723K. The anodic behavior of SiC was also investigated in the bath. In all materials, reactions of CO2 and CO3 2- occurred, and electrodes were consumed; a graphitization degree slightly influenced the consumption at graphite material, and the consumption of GC seemed the lowest. Although SiO2 was formed on SiC material, the consumption of SiC was not prevented completely. The unevenness of SiO2 layer on SiC might cause the consumption of SiC.