▎ 摘　　要

Asymmetric supercapacitor is fabricated using reduced graphene oxide-polymer (RGO-PEDOT.PSS) and reduced graphene-manganese oxide (RGO-CNF-MnO2) nanocomposites as negative and positive electrodes, respectively. Both the RGO-PEDOT. PSS and RGO-CNF-MnO2 (GCM) nanocomposite electrode were studied systematically with three electrode and asymmetric device configuration. The cyclic voltammetry (CV) and galvanostatic charge-discharge (CD) studies revealed a maximum specific capacitance of 247 F/g at 1 A/g between -0.9 to 0.1 V (vs. SCE) for RGO-PEDOT. PSS electrode. While the GCM nanocomposite electrode showed 145 F/g at 1 A/g between -0.1 to 0.9 V (vs. SCE). The X-ray diffraction (XRD) studies of GCM positive electrode revealed the formation of crystalline Akhtenskite MnO2 hexagonal structure and the XRD of RGO-PEDOT. PSS confirms the complete reduction of graphene oxide (GO). The microscopic images of GCM demonstrate the MnO2 nanowhiskers growth over the carbon support. The fabricated asymmetric supercapacitor device showed a cell voltage of 1.8 V in 1 M Na2SO4 electrolyte. The CD profile of RGO-PEDOT. PSS//RGO-CNF-MnO2 shows the device capacitance of 47 F/g with a high energy density of 21 Wh/kg while the symmetric device shows 5 and 5.6 Wh/kg for negative and positive electrodes respectively. The high energy density and electrochemical stability of the prepared asymmetric device is promising for electrochemical energy storage in aqueous electrolyte.