In this work, ternary nanocomposites of iron (II and III) oxides/reduced graphene oxide/polypyrrole (iron oxide/rGO/PPy) have been prepared as the electrode materials of the supercapacitor. These nanocomposites were prepared via a facile two-step process including, the synthesis of iron oxides/rGO binary nanohybrids by a one-pot chemical-microwave method and in-situ oxidative polymerization. The morphological and structural characterizations of these nanocomposites were demonstrated decoration of the iron oxides on GO sheets and proper formation of iron oxide/rGO/PPy ternary nanocomposites. The electrochemical performance evaluation of the samples revealed charge storage mechanisms in both the binary and ternary nanocomposites. A high specific capacitance of 626.8 F g-1 was obtained for the Fe2O3/rGO/PPy nanocomposite at a constant current density of 1 A g-1 in a 1 M H2SO4 solution electrolyte. This high specific capacitance (vs 158.2 F g-1 for Fe3O4/rGO/PPy) can be assigned to the attendance of both electrical double-layer capacitance (EDLC) and pseudocapacitance mechanisms in its charge storage. The Fe2O3/rGO/PPy nanocomposite revealed the highest energy density of 87.05 Wh kg-1 with a corresponding power density of 500 W kg-1. The frequency dependence and relaxation time constant investigation of these ternary nanocomposites revealed an ideal capacitive behavior at very low frequency and resistive behavior at the higher frequencies.

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