We report the preliminary analysis of a new cathode material and the performance of secondary lithium cells which contain it. The material is comprised of an organosulfur compound, 2,5-dimercapto-1,3,4-thiadiazole (DMcT), doped with a copper(ll) salt in a poly(aniline) matrix. Secondary lithium cells which use this material as cathodes can be discharged at 300 Ah per kg-cathode for ca. 10 cycles, 260 Ah per kg-cathode for at least 80 cycles, or 170 Ah per kg-cathode for ca. 130 cycles. Fur?her, after failure of these cells, replacement of the lithium anode restores the original capacity. Vibrational and electronic spectroscopy of the copper(ll)/DMcT system agree with previous reports on the redox chemistry which occurs between Cu(ll) and thioamide groups. A preliminary cyclic voltammetric study of this system indicates that the electroactive compound is probably a Cu(I)/DMcT complex which does not exhibit traditional electrocatalytic behavior, most likely due to the effects of proton-coupling in the redox processes of DMcT.