Si production by direct electrolytic reduction of solid SiO2 in molten CaCl2

Kouji Yasuda, Toshiyuki Nohira, Koji Amezawa, Yukio H. Ogata, Yasuhiko Ito

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


Morphological and crystallographic investigations were conducted on the Si produced by direct electrolytic reduction of solid SiO2 in molten CaCl2 at 1123 K. From the results of SEM, it was proved that the produced Si had columnar shape. FE-SEM observation showed that the Si column had basically a hexagonal prismatic and stacking structure. The results of TEM and ED revealed that the Si column was a single crystal having {111} twin planes perpendicular to the major axis of the column. It is explained that amorphous Si is firstly formed by electrochemical reduction and then thermally transformed to crystalline Si. Purity of the Si was proved by EDX to be more than 99.9%. Current efficiency for the reduction of SiO2 to Si was calculated as 74% at 0.70 V.

Original languageEnglish
Title of host publicationMolten Salts XIV - Proceedings of the International Symposium
Number of pages7
Publication statusPublished - 2006 Dec 1
Externally publishedYes
Event206th ECS Meeting - Honolulu, HI, United States
Duration: 2004 Oct 32004 Oct 8

Publication series

NameProceedings - Electrochemical Society
VolumePV 2004-24


Other206th ECS Meeting
Country/TerritoryUnited States
CityHonolulu, HI

ASJC Scopus subject areas

  • Engineering(all)


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