Electrolytic production of silicon using liquid zinc alloy in molten CaCl2

Kouji Yasuda, Takeyuki Shimao, Rika Hagiwara, Takayuki Homma, Toshiyuki Nohira

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)

Abstract

A new electrolytic production process for solar-grade Si has been proposed utilizing liquid Si–Zn alloy cathode in molten CaCl2. To establish this process, the behavior of liquid Zn metal in molten CaCl2 at 1123 K was investigated. Evaporation of Zn metal was largely suppressed by immersion in the molten salt, which enabled the use of a Zn electrode despite its high vapor pressure. Cyclic voltammetry results suggested that the reduction of SiO2 on a Zn cathode proceeded at a more negative than 1.45 V vs. Ca2+/Ca. After potentiostatic electrolysis at 0.9 V, Si particles with sizes of 2–30 μm were precipitated in the solidified Zn matrix by a slow cooling process. The rate-determining step for electrochemical reduction of SiO2 on the Zn cathode was discussed on the basis of a measurement of the alloying rate between solid Si and liquid Zn.

Original languageEnglish
Pages (from-to)H5049-H5056
JournalJournal of the Electrochemical Society
Volume164
Issue number8
DOIs
Publication statusPublished - 2017

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films
  • Electrochemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Electrolytic production of silicon using liquid zinc alloy in molten CaCl<sub>2</sub>'. Together they form a unique fingerprint.

Cite this