A new method for electroplating Si using a water-soluble KF-KCl molten salt electrolyte and high-purity gaseous SiCl4 has been proposed. To gain a fundamental understanding of the process, the electrodeposition of Si from Si(IV) complex ions on a Ag electrode in a molten KF-KCl-K2SiF6 system was investigated by cyclic voltammetry at 923 K. The reduction of Si(IV) ions to metallic Si was observed as a single 4-electron wave, which is explained by an EqEr (quasireversible-reversible electron transfer reactions) mechanism. The diffusion coefficient of the Si(IV) ions in the electrolyte was determined to be 3.2 x 10(-5) cm(2) s(-1) at 923 K by chronoamperometry. (C) 2015 The Electrochemical Society. All rights reserved.