Electrodeposition of Silicon from the Low-Melting LiCl-KCl-CsCl-K2SiF6 Electrolytes

The possibility of silicon electrodeposition from the low-melting LiCl-KCl-CsCl-K2SiF6 electrolytes has been studied. The stability of a silicon-containing additive was studied by cyclic voltammetry, and the rate constant of the chemical reaction of SiF4 release at a temperature of 827 K was calculated. It is determined that the constants of velocity values in the melt based on eutectic composition are 2 orders of magnitude higher, which indicates a higher rate of formation of volatile compounds. Cyclic voltammetry was also used to study the electrochemical behavior of K2SiF6 in the melts under study. It was found that the silicon electroreduction at the cathode is not reversible and proceeds in one 4-electron reaction. The diffusion coefficient calculated by the Matsuda-Ayabe equation was 0.72 center dot 10(-5) cm(2)center dot s(-1) at temperature of 823 K. According to the obtained voltammograms, the parameters for the silicon electrodeposition were selected. At a potential of -0.4 V vs QRE, dendritic silicon deposits were obtained.

Automated summary

The possibility of silicon electrodeposition from low-melting LiCl-KCl-CsCl-K2SiF6 electrolytes was studied. The stability of a silicon-containing additive and the rate constant of SiF4 release were found to be temperature dependent. The electrochemical behavior of K2SiF6 in the melts was irreversible and proceeded through a 4-electron reaction. Dendritic silicon deposits were obtained under selected deposition parameters.