The impact of polypyrrole:carboxymethyl cellulose composite nanostructure on conductivity and capacitance

Abstract

Polypyrrole is a popular conjugated polymer that becomes highly conductive in its p-doped state. The intrinsically non-polar nature of the conjugated bond network limits the processing options of such polymers. Surfactants and polyanions help increase dispersity of conductive polymer in suitable solvents for processing. However, while such dispersions can be highly stable, they are formed by complex nanostructures that significantly impact the conducting polymer composite’s bulk properties. Similarly, complex nanostructures can be formed when surfactants or polyelectrolytes serve as templates during the polymerization of the conducting polymer precursor. Following the report of polypyrrole:carboxymethyl cellulose composites in battery electrodes as conductive binders, we are here investigating the role that nanostructure control can have in optimizing their performance. Using methyl orange as a structural template, we can control the composite’s nanoscopic shape between nanospheres and nanofibers. In the bulk material, the latter gives rise to significantly increased electronic conductivity and capacitance in battery use conditions, underlining the opportunities for improved performance of conducting polymer composites by controlling synthesis conditions.