Temperature dependent transport properties of aluminum chloride in thionyl chloride solutions: A non-aqueous battery electrolyte study.

Abstract

This thesis is a physical chemical study of the AlCl$\sb3$/SOCl$\sb2$ system. Conductivity, viscosity, and density were determined for AlCl$\sb3$ concentrations ranging from 0 to 35 weight percent in SOCl$\sb2$, and over the temperature range $-$35 to 20$\sp\circ$C. The measured conductivity was in the $\mu$Scm$\sp{-1}$ range, indicating the solution to be a weak electrolyte. Viscosities ranging from 0.7 cP for pure SOCl$\sb2$, to 3.0 cP for 4.0M AlCl$\sb3$ were found, with viscosity increasing with increasing salt concentration. The solution densities for all concentrations considered were approximately 1.7g/ml, and thermal expansivity, $\alpha\sb{\rm TE}$, was approximately 1000$\sp\circ$K$\sp{-1}$, (5 times greater than $\alpha\sb{\rm TE}$ of water). Experimental results indicate that no abrupt change in the distribution of species in solution occurs, either as a function of solute concentration or temperature. The physical properties of these solutions were observed to change gradually and smoothly with both solute concentration and temperature indicating that a mechanistic change in the Li/SOCl$\sb2$ cell operation does not likely occur as a result of changes in bulk electrolyte properties. (Abstract shortened by UMI.)