Electrochemical Behavior of Silicon in the (NaCl-KCl-NaF-SiO2) Molten Salt

The electrochemical behavior of silicon was investigated in a molten salts system including saturation silicon dioxide. Silicon was electrodeposited and MoSi 2 was formed on the employed molybdenum working electrode by the diffusivities of silicon and the substrate metals. Transient electrochemical techniques such as cyclic voltammetry and chronoamperometry were used to study the reaction mechanism at the molybdenum electrode. Cyclic voltammograms showed the possibility of electrodeposition of Si at −0.64 V versus Pt reference electrode in a NaCl-KCl-NaF-SiO 2 system at 1073 K (800 °C). The electrodeposition of Si is single-step charge-transfer process and the cathode process is irreversible. Chronoamperometry studies indicated that electrocrystallization of Si is controlled by progressive nucleation with a three-dimensional growth mechanism.