This paper reports an exploratory investigation on the effects of a colloidal phase on the conductivity of lithium-ion liquid electrolytes. The conductivities of liquid electrolytes comprising of organic solvents, lithium salts and a colloidal phase were characterized. The colloidal phase consisted of BaTiO3 and Al2O3. The conductivity of a separator material impregnated with liquid and colloidal electrolytes was also characterized. The low temperature conductivity enhancement in colloidal electrolytes was attributed to a formation of space charge region between the colloidal phase and liquid electrolyte. The space charge region appears to be essential for the formation of a high conductivity phase. (C) 2004 Elsevier B.V. All rights reserved.