Redox-active polypyrrole: Toward polymer-based batteries

Abstract

A device consisting of two electrodes coated with polypyrrole (pPy) doped with different redox-actice compounds for energy storage, the performance parameter of which reside between a rechargeable battery and an ultracapacitor was analyzed. This feature is uniquely different from batteries or electrochemical capacitors that depend solely on redox reactions or doping/developing of conducting polymers. The enhanced performance of the device is derived from a combination of merits found in batteries and electric double-layer capacitor (EDLC). The cationic charge that develops in the pPy during the electropolymerization of pyrrole requires an influx of anions from the electrolyte to maintain charge neutrality. The results show that the molecular-level incorporation of electroactive molecules into conducting polymers can provide a spectrum of materials useful for energy-storage devices.