Electrochemical Investigation on Chlorine and Electrolyte Intercalation into Graphite Anodes during Magnesium Electrolysis Process

Cyclic voltammetry(CV) was used to investigate chlorine and electrolyte intercalation into three different graphite anodes from NaCl-KCl-MgCl2 melts at 700 degree C. They were needle-coke (NC), the petroleum-coke (FPC) and common petroleum-coke (CPC), respectively with the same processing technology. Chlorine intercalation amount was characterized by the reduction current (reduction electricity quantity) on the reverse scan during the cyclic voltammograms. And the electrolyte intercalation was presented by the increase in oxidation charge between the forward.scan and the reverse scan during the CV measurements. The results show that among the three graphite anodes, NC shows the lowest reduction current and nearly no increase in the charge, while about 5-10 times increase in the charge for the PFC and CPC,which implied that NC has a better resistance to electrolyte and chlorine intercalation.The results were further confirmed by the electrolysis experiments in NaCl-KCl-MgCl2 melts at 700 degree .