TY - JOUR
T1 - Electrolytic production of silicon using liquid zinc alloy in molten CaCl2
AU - Yasuda, Kouji
AU - Shimao, Takeyuki
AU - Hagiwara, Rika
AU - Homma, Takayuki
AU - Nohira, Toshiyuki
N1 - Funding Information:
This study was partially supported by Core Research for Evolutionary Science and Technology (CREST) from the Japan Science and Technology Agency (JST); Grant-in-Aid for Scientific Research A, grant Number 16H02410, from the Japan Society for the Promotion of Science (JSPS); The Japan Prize Foundation; and the Kato Foundation for Promotion of Science. The purified SiO2 granules were supplied by Taiheiyo Cement Corporation.
Publisher Copyright:
© The Author(s) 2017. Published by ECS. All rights reserved.
PY - 2017
Y1 - 2017
N2 - 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.
AB - 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.
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U2 - 10.1149/2.0121708jes
DO - 10.1149/2.0121708jes
M3 - Article
AN - SCOPUS:85036474857
SN - 0013-4651
VL - 164
SP - H5049-H5056
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
IS - 8
ER -