Electrochemical investigation on chlorine and electrolyte intercalation into graphite anodes during magnesium electrolysis process

摘要

Cyclic voltammetry (CV) was used to investigate chlorine andelectrolyte intercalation into three different graphite anodes fromNaCl-KCl-MgCl_2 melts at 700°C. The three anodes werecomposed of needle-coke (NC), petroleum-coke (FPC) andcommon petroleum-coke (CPC), respectively. Chlorineintercalation amount was characterized by the reduction current(reduction electricity quantity) on the reverse scan during thecyclic voltammograms. And the electrolyte intercalation waspresented by the increase in oxidation charge between the forwardscan and the reverse scan during the CV measurements. Theresults show that among the three graphite anodes, NC shows thelowest reduction current and nearly no increase in the charges,while about 5-10 times increase in the charge for the PFC andCPC. The above results implied that NC has a better resistance toelectrolyte and chlorine intercalation, which were confirmed bythe electrolysis experiments results. As a simple and usefulmethod, CV can be used to test graphite anode corrosionresistance to electrolyte and chlorine in chloride system.