ELECTRODEPOSITION OF TIN FROM AMBIENT-TEM PERATURE MOLTEN-SALT ELECTROLYTE AND IONIC SPECIES IN THE ELECTROLYTE

Electrodeposition of Sn from SnCl2-1-butylpyridinium chloride(BPC) amb ient temperature molten salt electrolytes was studied. The SnCl2-BPC b inary salts melted at ambient temperatures. The conductivity and the v iscosity of 33.3 mol% SnCl2 melt were 29.5 mS.cm(-1) and 7.4 mPa.s at 130 degrees C, respectively. Cyclic voltammograms on Pt electrode show er that the deposition potentials of Sn in the 33.3 mol% SnCl2 and the 66.7 mol% SnCl2 melts are about -0.65 V and 0.07 V vs. Sn(II)/Sn(0), respectively. The ionic species in the melt were also investigated by using the computer simulation method. The major ionic specie in the 33 .3 mol% SnCl2 melt is SnCl3- and that in the 66.7 mol% SnCl2 melt is S n2Cl5-. The optimized structures of SnCl3- and Sn2Cl5- calculated by t he ab initio molecular orbital method were C-3v and C-2, respectively.