Availability evaluation of SiC anode in chloride molten salt electrolysis

摘要

Carbon or graphite is commonly used to anode material in molten salt electrolysis, but they are consumed by a electrochemical reaction with a residual O~(2-) in the bath. In this study, the dependence of anodic behavior in molten chloride containing O~(2-) 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 CO_2 and CO_3~(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 SiO_2 was formed on SiC material, the consumption of SiC was not prevented completely. The unevenness of SiO_2 layer on SiC might cause the consumption of SiC.