TY - JOUR
T1 - Multi-potential electropurification of a reusable CaCl2-CaF2 eutectic salt for solar-grade Si electrorefining
AU - Tseng, Mao Feng
AU - Ricci, Lewis
AU - Tao, Meng
N1 - Funding Information:
This work was partially supported by the United States National Science Foundation (grant number 1904544).
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/11/1
Y1 - 2021/11/1
N2 - Molten-salt electrorefining is a promising technique for energy-efficient production of ultrapure solar-grade Si. This work focuses on electropurification to remove impurities from an eutectic CaCl2-CaF2 molten salt for solar-grade Si. Both an as-received salt and a salt used for Si electrorefining have been electropurified by a field-enhanced process and the impurity concentrations before and after purification have been characterized by inductively-coupled plasma mass spectrometry and cyclic voltammetry. More importantly, a new multi-potential electropurification process, enabled by the three-electrode electrolyzer, has been proposed and proven to be more effective in removing all the impurities in the molten salt than a single-potential process. The salt after Si electrorefining has been regenerated to its original purity level before Si electrorefining by the multi-potential process, demonstrating the feasibility of a reusable salt by electropurification.
AB - Molten-salt electrorefining is a promising technique for energy-efficient production of ultrapure solar-grade Si. This work focuses on electropurification to remove impurities from an eutectic CaCl2-CaF2 molten salt for solar-grade Si. Both an as-received salt and a salt used for Si electrorefining have been electropurified by a field-enhanced process and the impurity concentrations before and after purification have been characterized by inductively-coupled plasma mass spectrometry and cyclic voltammetry. More importantly, a new multi-potential electropurification process, enabled by the three-electrode electrolyzer, has been proposed and proven to be more effective in removing all the impurities in the molten salt than a single-potential process. The salt after Si electrorefining has been regenerated to its original purity level before Si electrorefining by the multi-potential process, demonstrating the feasibility of a reusable salt by electropurification.
KW - Molten salt electropurification
KW - Multi-potential electropurification
KW - Reusable molten salt
KW - Silicon electrorefining
KW - Three-electrode electropurification
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U2 - 10.1016/j.seppur.2021.119030
DO - 10.1016/j.seppur.2021.119030
M3 - Article
AN - SCOPUS:85106576978
SN - 1383-5866
VL - 274
JO - Separation and Purification Technology
JF - Separation and Purification Technology
M1 - 119030
ER -