Fundamental study on reduction rate for electrolytic reduction of SiO 2 powder in molten CaCl2

Tetsuya Toba, Kouji Yasuda, Toshiyuki Nohira, Rika Hagiwara, Koki Ichitsubo, Kenta Masuda, Takayuki Homma

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)

Abstract

Direct electrolytic reduction of powdery SiO2 has been investigated in molten CaCl2 at 1123 K aiming at a low cost and mass production of solar-grade Si. SiO2 powder was set on a Si plate which was installed at the bottom of the crucible and connected to a graphite rod used as a current lead. SiO2 powder was reduced to Si by cathodic polarization of the Si plate. The reduction rate was evaluated by the magnitude of the reduction current, in which three parameters were varied: electrode potential, SiO2 layer thickness, and SiO2 particle size. As a result, the ratedetermining step of the reduction is suggested to be the diffusion of O2- ions inside the reduced porous Si particles filled with the electrolyte. During the reduction process, however, other factors such as contact resistance between Si particles and porosity of SiO2 particles possibly influence the reduction rate.

Original languageEnglish
Title of host publicationMolten Salts and Ionic Liquids 18
Pages119-126
Number of pages8
Edition11
DOIs
Publication statusPublished - 2012 Dec 1
Event18th International Symposium on Molten Salts and Ionic Liquids - 222nd ECS Meeting - Honolulu, HI, United States
Duration: 2012 Oct 72012 Oct 12

Publication series

NameECS Transactions
Number11
Volume50
ISSN (Print)1938-5862
ISSN (Electronic)1938-6737

Conference

Conference18th International Symposium on Molten Salts and Ionic Liquids - 222nd ECS Meeting
CountryUnited States
CityHonolulu, HI
Period12/10/712/10/12

ASJC Scopus subject areas

  • Engineering(all)

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