Poly[3,4-(ethylenedithio)thiophene] (PEDTT) has been synthesized by oxidative-coupling polymerization of 3,4-(ethylenedithio)thiophene (EDTT) in the absence of solvent at ambient conditions. The resulting polymer has been characterized by FT-IR, XRD. TGA, UV-vis and Solution NMR analyses. In addition, PEDTT has been evaluated as the cathode active material for rechargeable lithium batteries. The charge-discharge tests are carried out at room temperature. PEDTT shows discharge specific capacity above 425 mAh g(-1). It is tentatively proposed that electrode reaction involves the formation of thioether cation, which imparts multi-electron redox reaction, high discharge specific capacity, high charge voltage and low discharge voltage. (C) 2008 Elsevier B.V. All rights reserved.