Binder-free PEO/PPy/PEDOT:PSS layer coated on nickel foam for high-performance asymmetric supercapacitor applications

Conducting polymers have recently attracted considerable attention for supercapacitor applications. This study demonstrates that the combination of poly ethylene oxide (PEO) with two conducting polymers, polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) PEDOT:polystyrene sulfonate (PSS), can be synthesized using an aqueous polymerization method and used as an active electrode material for supercapacitor applications. The chemical composition and surface morphology of the PEO, PEO/PPy, PEO/PEDOT:PSS, and PEO/PPy/PEDOT:PSS conducting polymers were examined using Fourier-transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and field-emission scanning electron microscopy analyses. Furthermore, the electrochemical performance of the composites coated electrodes was investigated using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge–discharge analyses (GCD) in aqueous 2 M KOH electrolyte. The GCD results in a three-electrode system were evidenced by the pseudocapacitive behavior of PEO/PPy/PEDOT:PSS providing a maximum specific capacitance of 524.4 F/g at a current density of 2 A/g. The cyclic stability performance was studied at a current density of 2 A/g for 5000 continuous cycles and showed a capacity retention of 89.8%. Furthermore, the asymmetric PEO/PPy/PEDOT:PSS//RGO device exhibited an excellent energy density of 33.0 Wh kg−1 at a power density of 725.0 W kg−1. This outstanding supercapacitor performance demonstrates that PEO/PPy/PEDOT:PSS is a promising material for high-performance supercapacitors.