Uniform polypyrrole electrodeposition triggered by phytic acid-guided interface engineering for high energy density flexible supercapacitor

Unevenly distributed polypyrrole (PPy) films/coatings with extensive dead volumes via electrodeposi-tion have emerged as a main challenge for high energy density flexible supercapacitor. In this work, we have fabricated a phytic acid-guided graphite carbon felt/polypyrrole (GF@PA@PPy) 3D porous composite with less dead volumes via electrodeposition. After the activation of phytic acid (PA), the quantity and content of defects and oxygen-containing groups on the surface of carbon felt (GF) have increased. First, these functional groups improve the hydrophilicity of the surface of GF, resulting in the preferential uni-form distribution of pyrrole monomer (Py). While significantly, the synergistic effects between the defects and oxygen-containing groups boost the attraction of pyrrole ring, and thus promotes the forma-tion of perfect PPy films with less dead volume on GF. Finally, the supercapacitor assembled from the GF@PA@PPy-40 displays a high areal energy density of 0.0732 mWh cm(-2), exceeding the previously reported PPy-based electrodes values. The deeper understanding of the role for the defects and oxygen-containing groups in the synthesis of PPy/carbon materials offers a new strategy to construct advanced PPy-based supercapacitors. (C) 2021 Published by Elsevier Inc.

Automated summary

Unevenly distributed polypyrrole films/coatings with extensive dead volumes via electrodeposition pose a challenge for high energy density flexible supercapacitors. In this study, a phytic acid-guided graphite carbon felt/polypyrrole 3D porous composite was fabricated with less dead volumes, leading to a higher areal energy density. The activation of phytic acid on the surface of carbon felt increased defects and oxygen-containing groups, which synergistically promoted the formation of perfect PPy films with less dead volume.