Lightweight Rechargeable Storage Batteries Using Polyacetylene, ( CH ) x as the Cathode‐Active Material

Polyacetylene, can be controllably doped electrochemically through the semiconducting to the metallic regime using a solution of in propylene carbonate and a lithium cathode. Flexible, golden, free‐standing films of having conductivities up to ∼10 3 Ω −1 cm −1 are readily obtained. Electrochemical "undoping" of the allows this doped film to be used as the cathode‐active material in lightweight rechargeable storage batteries. The overall complete discharge reaction is A 0.5 cm 2 piece of the 6% doped film ( ; ∼3 mg) exhibited an open‐circuit voltage of 3.7V and an initial short‐circuit current of 25 mA. No change in the open‐circuit voltage characteristics of a battery could be detected even after 326 successive constant current partial charge/discharge cycles. No degradation of the polyacetylene electrode was observed. Experimental energy densities of ∼176 W‐hr/Kg were obtained based on the weight of the initially employed and the weight of Li consumed (exclusive of weights of electrolyte, solvent, and packaging material) during partial discharge when was converted to .