Pseudocapacitive electrode performance of zinc oxide decorated reduced graphene oxide/poly(1,8-diaminonaphthalene) composite

Abstract

Development of Reduced graphene oxide/Zinc oxide/poly(1,8-diaminonaphthalene) (rGO/ZnO/PDAN) composite and its supercapacitor performance has been evaluated. Functional, crystal and morphological structures along with the thermal stability of the polymer-impregnated composite were studied using analyses such as FTIR, powder XRD, Raman, SEM and TGA techniques. The SEM images showcased the random decoration of irregularly shaped ZnO in between the wrinkled rGO sheets and the PDAN. The defective structure of the hybrid composite contributes capacitive features through electron transfer kinetics. The specific capacitance value for the rGO/ZnO/PDAN composite modified NF electrode in 3 M KOH was found to be 239 F/g at the current density of 0.5 A/g. The capacitance retained is 92 % after 5000 cycles at 5 A/g current density. A solid-state symmetrical supercapacitor device based on a novel rGO/ZnO/PDAN composite was successfully developed, which exhibits the specific capacity (40 at 0.6 A/g), energy density (12.66 Wh/kg) and power density (993 W/kg). The synergistic combination of surface-active nitrogen heteroatoms, extended conjugation and ZnO particles decorated over rGO sheets of rGO/ZnO/PDAN ternary hybrid composite displayed significant structural stability and electrochemical pseudocapacitive performances.