New electrochemically active highly sulfurized polyconjugated polymers

The electrochemical activity of new highly sulfurized polyconjugated polymers is studied. The polymers, polythienothiophene, poly(4,5,6,7-tetrathieno-4,5,6,7-tetrahydro-2,3-dehydrobenzothiophene), poly(6-methylthieno[2,3-b]pyridine-4-thione-5-thiol), and poly(6H-thieno[2,3-b]-azepine-6,7(8H)-dithione) are obtained in a deep sulfurization of polyethylene, polystyrene, and poly(5-vinyl-2-methylpyridine) by elemental sulfur. Employed as active cathodic material in lithium batteries, these polymers ensure their prolonged cycling with specific discharge capacity of up to 339 mA h/g. The effect of the conducting additive and electrolyte on the energy capacity and cycling of polymer cathodes in lithium batteries is discussed.