ORGANOSULFUR POLYMER BATTERIES WITH HIGH-ENERGY DENSITY

The redox reaction of 2,5-dimercapto-1,3,4-thiadiazole (DMcT) at the e lectrode surfaces is slow at room temperature and influenced strongly by the acidity of the solutions. However, this reaction can be acceler ated when the electron-transfer reaction is coupled with that of polya niline (PAn). PAn can be used as a molecular current collector for the insulating organosulfur compounds which are promising high capacity e nergy storage materials. The charge/discharge capability of a polymer composite cathode prepared from DMcT, PAn, 3-alkylcarboxylate-4-methyl pyrrole and acetylene black has been investigated on different types o f current collector, such as copper and porous carbon film, in a lithi um-cell system with a gel-like polymer electrolyte. A battery assemble d from the polymer composite cathode with a copper current collector p rovides a flat discharge potential difference from 3.4 to 2.8 V and hi gh current capability (137-194 A/kg-cathode) without undue deteriorati on of the energy density. The battery can be charged up to 550 W h/kg- cathode within 1.25 h and reversibly discharged within 1.25 h. (C) 199 7 Elsevier Science S.A.