Controlled and Solvent-free Synthesis of Polypyrrole for Energy Storage
Fika Fauzi*, Yizeng Di, Dulce M. Morales, and Ranjita K. Bose
Engineering and Technology Institute Groningen (ENTEG), University of Groningen, Nijenborgh 3, 9747AG Groningen, The Netherlands
*Presenting author, email: f.fauzi@rug.nl
Oxidative chemical vapor deposition (oCVD) is a solvent-free method for synthesizing uniform, conformal thin films of conductive polymers with tunable properties. We investigated parameters involved in oCVD for synthesizing polypyrrole (PPy), which is well known for its versatility for many applications. We focused on the effects of nitrogen gas flow rate and deposition time on the structure and properties of PPy. The results show that increasing the nitrogen flow rate enhances the distribution of the oxidant, increasing the polaronic defects, which significantly deteriorate the polymeric structure and reduce electrical conductivity. Meanwhile, extending the deposition time increases the film thickness linearly due to longer reaction time and initially enhances the electrical conductivity until it reaches a plateau at approximately 75 S/cm2 [1].
Furthermore, we successfully deployed the PPy synthesized by oCVD for energy storage devices. We deposited a sub-micron-thick layer of PPy onto porous carbon fabric (CF) for supercapacitor electrodes. The resulting PPy coatings exhibit uniform, conformal, and retain the porosity of CF. The supercapacitive performance of the electrodes was then analyzed using electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic charge-discharge measurements. Finally, the PPy/CF electrodes were used to fabricate a symmetric supercapacitor device, which exhibits ideal capacitive behavior, high rate capability (up to 500 mV/s), and a stable operational voltage of 1 V. These findings highlight the ability of oCVD to precisely control the synthesis of conductive polymers, which advances the design of conductive polymer .
Reference
[1] F. Fauzi and R. K. Bose, "Mechanistic study of oxidative chemical vapor deposition of polypyrrole: Effects of the inert gas and deposition time," Applied Surface Science Advances, vol. 25, p. 100673, 2025/01/01/ 2025, doi: https://doi.org/10.1016/j.apsadv.2024.100673.