Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (05): 1108-1115.doi: 10.3866/PKU.WHXB20110504

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Electrodeposition Behavior of Silicon from Na3AlF6-LiF Melts

JIA Ming, LAI Yan-Qing, TIAN Zhong-Liang, LIU Fang-Yang, LI Jie, XIN Peng-Fei, LIU Ye-Xiang   

  1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, P. R. China
  • Received:2010-12-27 Revised:2011-02-25 Published:2011-04-28
  • Contact: TIAN Zhong-Liang E-mail:tianzhongliang@126.com
  • Supported by:

    The project was supported by the Specialized Research Fund for the Doctoral Program of Higher Education, China (200805331120), Hunan Provincial Innovation Foundation For Postgraduate and Graduate Degree Thesis, China (CX2009B036), and Innovation Foundation of Central South University, China (2010 bsxt02).

Abstract:

A fundamental electrochemical study of Si in Na3AlF6-LiF melts and electrowinning and electrorefining in a small-scale laboratory cell was conducted. Cyclic voltammograms showed that the reduction of Si proceeds by two successive electron transfers and the presence of the Si(II) species in the melt was confirmed. Galvanostatic electrolysis showed that the deposited silicon crystal does not form any dense or massive layer at the graphite cathode as other metals do, but it is generally dispersed in the deposit around the cathode. The co-deposition of Al and Si is possible when the reduction potentials are more negative than -1.8 V versus Pt. The purity of the deposited Si was higher than 99.9%. This study demonstrates the feasibility of very pure Si production by electrochemical methods.

Key words: Silicon, Deposition, Electrowinning, Electrorefining, Purity

MSC2000: 

  • O646