Insights From Synthesis to Performance of Polyaniline/Multiwalled Carbon Nanotube/Zinc Oxide/Nickel Oxide Nanocomposite for Hybrid Supercapacitors

Need for high‐performance, efficient, and economical devices for next‐generation energy storage technologies have led researchers to explore supercapacitors (SC) as alternative. A novel hybrid composite (HC)‐based device comprising polyaniline (PANI), multiwalled carbon nanotubes (MWCNTs), zinc oxide (ZnO), and nickel oxide (NiO) was developed via in situ oxidative polymerization and hydrothermal processing for high‐performance SC applications. The composite integrates the pseudocapacitive behavior of transition metal oxides with the superior conductivity of PANI and MWCNT. Structural and morphological analyses confirmed a highly interconnected hybrid network, where PANI formed a conductive polymeric matrix, MWCNTs facilitated rapid electron transport, and ZnO/NiO nanoparticles provided abundant redox‐active sites. Electrochemical experiments conducted with the HC‐based device exhibit a specific capacitance of 319.52 F g −1 at 1 A g −1 , surpassing individual components. The HC‐based device delivered an energy density of 63.90 Wh kg −1 at a power density of 0.6 kW kg −1 , retaining 78% capacitance after 10,000 cycles at 12 A g −1 . This enhanced performance, confirmed by electrochemical impedance spectroscopy analysis showing low charge‐transfer resistance and efficient ion diffusion, underscores the synergistic interaction among its constituents. The composite's outstanding electrochemical characteristics establish it as a promising candidate for next‐generation, high energy density, long cycle life SCs.