Fabrication hierarchical polyaniline–polythiophene co-polymer anchored iron hexacyanoferrate hybrid electrode for next-generation supercapacitors

This study used an in-situ oxidative copolymerization technique to rationally design an iron hexacyanoferrate (FeHCF)/polyaniline–polythiophene (PANI–PT) hybrid electrode. X-ray diffraction analysis confirmed the preservation of the characteristic crystalline structure of FeHCF after hybrid formation. Morphological studies revealed the uniform distribution of FeHCF nanostructures within the conductive PANI–PT copolymer network, forming an interconnected hybrid architecture that facilitates efficient charge transport. Nitrogen adsorption–desorption analysis indicated the presence of a mesoporous structure, where the pristine FeHCF exhibited a specific surface area of ∼85 m² g⁻¹ , which increased to ∼215 m² g⁻¹ after hybridization with the PANI–PT copolymer. This enhanced surface area provides additional electroactive sites and improves electrolyte accessibility. The FeHCF/PANI–PT electrode exhibited exceptional electrochemical stability, as evidenced by its high specific capacitance of 657 F g⁻¹ at 1 A g⁻¹ , excellent rate capability, and approximately 93% capacitance retention after 5000 charge–discharge cycles. Additionally, the assembled asymmetric supercapacitor, which is based on FeHCF/PANI–PT, demonstrated a high energy density of 11.2 Wh kg⁻¹ at a high power density of 7200 W kg⁻¹ , while maintaining a maximum energy density of 27.9 Wh kg⁻¹ at a power density of 780 W kg⁻¹ . The synergistic interaction between the redox-active FeHCF framework and the highly conductive PANI–PT copolymer matrix contributes to the improved electrochemical performance by accelerating electron transport and improving ion accessibility. This work offers a viable approach to the creation of conducting copolymer–hexacyanoferrate hybrid electrodes for advanced supercapacitor energy storage systems.