Hydrogen-bonding power interfacial load transfer of carbon fabric/polypyrrole composite pseudosupercapacitor electrode with improved electrochemical stability

Abstract

The design of a strong interface interaction is a critical issue to improve the electrochemical stability of polypyrrole (PPy) composite electrodes. In the natural world, hydrogen bond that powers the load transfer can be observed in spider silk. The challenges are to achieve interfacial hydrogen bond interaction to stiff the PPy to help the effective load transfer and alleviate the swelling/shrinkage of PPy chains. Here, a composite electrode was prepared by pyrrole (Py) vapor deposition on the air-plasma-activated carbon fabric (PCF) surface. The X-ray photoelectron spectroscopy and fourier transformed infrared spectroscopy results showed that the COOH groups appearing on the PCF and hydrogen bonds can be formed on the interface of PCF/PPy. Interfacial shear strength (IFSS) and scanning electronic microscope determined hydrogen bond on the interface of PCF/PPy enhance the adhesion and power the load transfer process from PPy to carbon fiber. These interfacial hydrogen bonds severed as adhesion points helped the load transfer effectively to the substrate and decreased the contact resistance, preventing the damage of PPy chains and improving electrochemical performances of PCF/PPy as the electrode for pseudosupercapacitor. The PCF/PPy supercapacitor showed excellent cycling stability (93% capacitance retention after 4000 cycles), while CF/PPy showed poor cycling stability (74% after 4000 cycles). The idea of hydrogen bond powered electrochemical stability can be of reference for the researchers to improve the cycling stability of other conductive polymers that are widely used in high-performance supercapacitor.