Synthesis of CuO Sentezi, rGO/CuO and rGO/CuO/PEDOT nanocomposites and their supercapacitor and equivalent circuit model evaluations

Supercapacitor properties of rGO, CuO, PEDOT and rGO/CuO at [rGO]o/[CuO]o= 1:1; 1:1.5; 1:2 and rGO/CuO/PEDOT nanocomposite at [rGO]o/[CuO]o/[EDOT]o= 1:1:1; 1:1:3; 1:1:5 were investigated using chemical reduction of GO and in- situ polymerization process. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET) surface area analysis confirm the nanocomposite formations. Nanocomposite materials are also analyzed through spectroscopic and thermo-gravimetric analysis (FTIR-ATR, Raman and TGA-DTA). Electrochemical performance were studied by galvonanostatic charge/discharge (GCD), cyclic voltametry (CV) and electrochemical impedance spectroscopy (EIS). The highest specific capacitance of Csp= 156.7 F/g at 2 mV/s is determined as rGO/CuO/PEDOT at [rGO]o/[CuO]o/[EDOT]o =1:1:5. In addition, two electrode supercapacitor device for rGO/CuO/PEDOT at [rGO]o/[CuO]o/[EDOT]o=1:1:5 are found to provide a maximum specific energy (E= 14.15 Wh/kg at 20 mA) and specific power (P= 24730 W/kg at 50 mA), electrical serial resistance (ESR= 13.33 Ω) with good capacity retention after 3000 cycles. An equivalent circuit model of LR1(CR2)(QR3) is proposed to interpret the EIS data. The supercapacitor performance of the rGO/CuO/PEDOT nanocomposite electrode indicates the synergistic effect of hybrid supercapacitors. Keywords : Supercapacitors, reduced graphene oxide, conductive polymers, Copper oxide, poly(3,4-ethylenedioxythiophene)