INFLUENCE OF THE SOLVENT ON THE DECOMPOSITION POTENTIALS OF NONAQUEOUS LITHIUM HEXAFLUOROARSENATE SOLUTIONS

The decomposition potentials of 0.5 M LiAsF6 solutions were studied as functions of the nature and composition of their binary solvents prep ared from acetonitrile, propylene carbonate, gamma-butyrolactone, dime thyl sulfoxide, dimethylformamide, sulfolane, dimethylacetamide, tetra hydrofuran, 1,2-dimethoxyethane, and methyl acetate. In the cathodic r egion, the decomposition potentials of the electrolytes studied were f ound to be due to lithium deposition and become more negative with inc reasing donor number of the solvent and increasing concentration of th e more basic component in the binary mixture. The anodic stability of LiAsF6 solutions in nonaqueous solvents was controlled by solvent oxid ation; here the decomposition potentials decreased with increasing don or number of the solvent. The trends of behavior observed were explain ed in terms of special features in interaction of the ionic and molecu lar forms in the solution.