Solid State Ionics, Vol.336, 80-86, 2019
High-performance electrode based on electrochemical polymerization of polypyrrole film on electrophoretically deposited CNTs conductive framework for supercapacitors
In this study, a binderless and high-performance polypyrrole/multi-walled carbon nanotubes (PPy/CNT) composite electrode was fabricated using an efficient two-step procedure with CNTs as support frameworks. CNTs were electrophoretically deposited on the graphite substrate followed by electrodeposition of PPy via a galvanostatic method, to fabricate PPy/CNT electrode. The as-prepared PPy electrodes were characterized by field emission scanning electron microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), nitrogen adsorption-desorption and contact angle measurements. Moreover, the supercapacitive performance of the electrodes was investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) at various constant rates and electrochemical impedance spectroscopy (EIS). The results confirm that CNTs web-like network with an open porous structure obviously enhances the pseudocapacitive performance of the PPy/CNT electrode, which is corresponding to the large electrochemical surface area with porous structure, high electrical conductivity and enhanced integrity of the electrode. Consequently, the composite electrode exhibits a high specific capacitance of 292 F g(-1) at 0.2 A g(-1), outstanding rate performance (79.8% capacitance retention from 0.2 A g(-1) to 5.0 A g(-1)) and superior cycling stability (89.2% capacitance retention after 1000 cycles at 1.0 A g(-1)). Therefore, this work may introduce a new and facile approach to develop high-performance and binder-free electrodes for energy storage devices.
Keywords:Polypyrrole;Carbon nanotubes;Electrodeposition;Energy storage and conversion;Supercapacitor