In situ synthesized PPY@CuO–NiO ternary nanocomposite for high-performance pseudocapacitors

Recent advancements in energy storage technology have highlighted the advantages of supercapacitors. Among them, pseudocapacitors have attracted significant attention because of their exceptional ability to balance power delivery and energy storage. In this study, polypyrrole (PPY) and a ternary PPY@copper oxide–nickel oxide (PPY@CuO–NiO) nanocomposite were synthesized through a simple in-situ chemical oxidation method to fabricate high-performance electrochemical pseudocapacitor electrodes. The structural, chemical, and optical characteristics of the PPY@CuO–NiO nanocomposite, examined by X-ray diffraction, field-emission scanning electron microscopy, Fourier-transform infrared spectroscopy, and ultraviolet–visible spectroscopy, revealed a highly porous architecture that enhanced surface area, electrical conductivity, and mechanical stability, providing additional electroactive sites and improved ion-diffusion pathways. The electrochemical performance was evaluated using cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. The PPY and PPY@CuO–NiO electrodes exhibited specific capacitances of 342 and 702 F g− 1, respectively, at a current density of 0.2 A g− 1. Moreover, the PPY and PPY@CuO–NiO electrodes retained 65.65% and 86.25% of their capacitance after 5000 charge–discharge cycles at the same current density. These findings indicated that the PPY@CuO–NiO nanocomposite benefited from a strong synergistic interaction between the conducting polymer matrix and the metal-oxide components, leading to enhanced charge transfer, reduced charge-transfer resistance, and improved overall capacitive performance.