The effect of various preparative parameters, such as the size and form of alumina and also the time of sintering, on the electrical conductivity of the Li2SO4-Al2O3 composite system has been investigated. The sintering time appears to be an insignificant preparative parameter. The role of different phases of Al2O3 on the electrical conductivity of the composite clearly establishes that the maximum enhancement is achieved for gamma-Al2O3. The 50 m/o Al2O3 composition was found to exhibit the highest conductivity, an enhancement of three orders of magnitude at 500degreesC. The experimental data indicates higher conduction in the space charge layer near the surface to be the possible mechanism of conductivity enhancement. (C) 2002 Elsevier Science Ltd. All rights reserved.