Modelling of GO/PPy/CB and rGO/PPy/CB nanocomposite supercapacitors using an electrical equivalent circuit

In this study, supercapacitor device performances of graphene oxide (GO), reduced graphene oxide (rGO), polypyrrole (PPy), and ternary nanocomposites of GO, PPy, and carbon black (CB) as GO/PPy/CB and rGO/PPy/CB were firstly prepared using the in situ polymerization method. The obtained composite materials were characterized by scanning electron microscopy energy-dispersive X-ray (SEM-EDX), Fourier-transform infrared-attenuated transmission reflectance (FTIR-ATR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), atomic force microscopy (AFM), Brunauer-Emmett-Teller (BET) surface area analysis, cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopic (EIS) methods. The highest specific capacitance (C-sp) of the rGO/PPy/CB nanocomposite was obtained as C-sp = 39, 48, and 27.86 F x g(-1) by three methods of CV, GCD, and EIS, respectively. Two equivalent circuit models of R-s(CdlRct) and LRs(QR(ct)) were presented to compare equivalent circuit parameters. Theoretical and experimental values are compatible with each other.