The electrochemical properties of 2,5-dimercapto-1,3,4-thiadiazole (DMcT)-polyaniline (PAn) composite films containing Ag nanoparticles (Ag-NPs; Phi 17 nm) were investigated. Adding the nanoparticles to DMcT-PAn composites, charge-discharge performance of the composite was enhanced due to electrocatalytic activation of DMcT by the nanoparticles. Optimum content of the Ag-NPs was 5 wt.%. The observed current enhancement was ascribed to the improve efficiency of DMcT utilization in the composites due to electrocatalytic activation of the DMcT redox reactions in the presence of Ag-NPs. (C) 2004 Elsevier Ltd. All rights reserved.