Abstract
The reaction mechanism of electrolytic reduction of SiO2 at a liquid Zn cathode in molten CaCl2 was investigated with the aim of establishing a new production process of solar-grade Si. Three types of Zn/SiO2 contacting electrodes were prepared depending on the objectives. Cyclic voltammetry suggested two reduction mechanisms of SiO2 at a Zn electrode. One is a direct electrolytic reduction that proceeds at potentials more negative than 1.55 V vs. Ca2+/Ca. The other is an indirect reduction by liquid Ca-Zn alloy at potentials more negative than 0.85 V. The both reduction mechanisms were confirmed to proceed at 0.60 V by electrolysis and immersion experiments. Impurity analysis by ICP-AES was conducted for the Si prepared by potentiostatic electrolysis at 0.60 V, and confirmed that the concentrations of the metal elements and P were lower than the target levels for primary Si before directional solidification process.
| Original language | English |
|---|---|
| Pages (from-to) | D162-D167 |
| Journal | Journal of the Electrochemical Society |
| Volume | 166 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2019 Jan 1 |
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ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Electrochemistry
- Materials Chemistry
Cite this
Mechanism of electrolytic reduction of SiO2 at liquid Zn cathode in molten CaCl2. / Ma, Yuanjia; Ido, Akifumi; Yasuda, Kouji; Hagiwara, Rika; Homma, Takayuki; Nohira, Toshiyuki.
In: Journal of the Electrochemical Society, Vol. 166, No. 6, 01.01.2019, p. D162-D167.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Mechanism of electrolytic reduction of SiO2 at liquid Zn cathode in molten CaCl2
AU - Ma, Yuanjia
AU - Ido, Akifumi
AU - Yasuda, Kouji
AU - Hagiwara, Rika
AU - Homma, Takayuki
AU - Nohira, Toshiyuki
PY - 2019/1/1
Y1 - 2019/1/1
N2 - The reaction mechanism of electrolytic reduction of SiO2 at a liquid Zn cathode in molten CaCl2 was investigated with the aim of establishing a new production process of solar-grade Si. Three types of Zn/SiO2 contacting electrodes were prepared depending on the objectives. Cyclic voltammetry suggested two reduction mechanisms of SiO2 at a Zn electrode. One is a direct electrolytic reduction that proceeds at potentials more negative than 1.55 V vs. Ca2+/Ca. The other is an indirect reduction by liquid Ca-Zn alloy at potentials more negative than 0.85 V. The both reduction mechanisms were confirmed to proceed at 0.60 V by electrolysis and immersion experiments. Impurity analysis by ICP-AES was conducted for the Si prepared by potentiostatic electrolysis at 0.60 V, and confirmed that the concentrations of the metal elements and P were lower than the target levels for primary Si before directional solidification process.
AB - The reaction mechanism of electrolytic reduction of SiO2 at a liquid Zn cathode in molten CaCl2 was investigated with the aim of establishing a new production process of solar-grade Si. Three types of Zn/SiO2 contacting electrodes were prepared depending on the objectives. Cyclic voltammetry suggested two reduction mechanisms of SiO2 at a Zn electrode. One is a direct electrolytic reduction that proceeds at potentials more negative than 1.55 V vs. Ca2+/Ca. The other is an indirect reduction by liquid Ca-Zn alloy at potentials more negative than 0.85 V. The both reduction mechanisms were confirmed to proceed at 0.60 V by electrolysis and immersion experiments. Impurity analysis by ICP-AES was conducted for the Si prepared by potentiostatic electrolysis at 0.60 V, and confirmed that the concentrations of the metal elements and P were lower than the target levels for primary Si before directional solidification process.
UR - http://www.scopus.com/inward/record.url?scp=85065094165&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85065094165&partnerID=8YFLogxK
U2 - 10.1149/2.1211904jes
DO - 10.1149/2.1211904jes
M3 - Article
AN - SCOPUS:85065094165
VL - 166
SP - D162-D167
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
SN - 0013-4651
IS - 6
ER -