The Study on Foundation of Electrodeposited Silicon in Fused Salts

The electrochemical reaction mechanism and diffusion coefficient of Si~(4+) are studied in FLINAK- Na2SiF6 system by Cyclic Voltammetry and Chronopotentionmetry at 750℃. Pt, silicon sheet and graphite are respectively reference electrode, working electrode and auxiliary electrode. The results indicate that electrodeposited silicon is viable in this fused salt system. The electrochemical reaction of Si~(4+) is reversible electrode process by diffusion controlling and the production cannot be dissolved; The whole electrochemical reaction process is Si~(4+) + 4e →Si~0, The electric potential of cathode shouldn't be less than -2V, or Na will be deposited out and affect the quality of deposit. Diffusion coefficient of Si~(4+) is 5.42×10~(-11)m~2/s.