Strategies to Optimize the Capacitive Behavior of Polypyrrole Electrodes

Abstract

Polypyrrole (PPR) and composite PPR-multi-walled carbon nanotube (MCNT) electrodes for electrochemical supercapacitors were manufactured using new anionic additives for PPR polymerization. The analysis of the microstructure of PPR and PPR-MCNTs and electrochemical testing data provided information on the influence of the dopants on the mechanism of chemical polymerization and properties of nanostructured PPR and PPR-MCNT materials. The increase of the size and charge of the aromatic dopants resulted in decreasing PPR particle size, reducing agglomeration, and promoted the formation of PPR coatings on MCNTs. New additives allowed for the manufacturing of advanced electrodes with high active mass loading, excellent capacitance at high charging–discharging rates, and cyclic stability. A capacitance of 2.67 F cm⁻² at a potential variation rate of 100 mV s⁻¹ was achieved using composite PPR-MCNT electrodes. The electrodes were applied for the manufacturing of supercapacitor cells, which showed good electrochemical performance.

Keywords:

• Composite
• Device
• Dispersant
• Dopant
• Electrode
• Nanotube
• Polypyrrole
• Supercapacitor

ACKNOWLEDGMENTS

We thank Vale Canada Company for Ni foam samples and NSERC Canada for the financial support.