Electrodeposition of Silicon in the Low-Temperature LiCl-KCl-CsCl-K2SiF6 Melt Under Direct and Pulse Current

Abstract

In this work, the effect of electrolysis modes and their parameters on the morphology of the silicon deposits on glassy carbon were studied. In direct current mode it was found that an increase in current density and deposition time changes the morphology of the silicon from a coating to a deposit with a complex surface. Scanning electron microscopy showed that silicon films produced at low current densities and a short deposition time are represented by spherical particles with a diameter of less than 1 μm. The pulse current mode made it possible to increase the cathode density of the deposition current, and the pulse current density to an average of ≈250 mA cm−2 does not lead to the formation of a large amount of dendritic deposit. It was found that a low frequency makes it possible to obtain higher-quality silicon coatings, because when the frequency increases, the coating most often does not cover the entire electrode. The high value of the duty cycle, even at low pulse current densities, always leads to the formation of dendrites. An increase in the total deposition time also leads to an increase in the amount of deposit and the formation of dendrites.