ZIF‐67–Prussian Blue Analogs Dual‐Metal‐Organic Framework Heterostructure‐Derived Co ₃ O ₄ /NiFe ₂ O ₄ Nanocomposite for High‐Performance Hybrid Supercapacitor

The growing demand for energy storage devices that combine high power density with high energy density has driven substantial progress in the development of advanced supercapacitor electrode materials. This study presents the development of a Co 3 O 4 /NiFe 2 O 4 nanocomposite derived from a ZIF‐67–Prussian blue analog heterostructure that simultaneously enhances the energy density and stability of supercapacitors. The rational design of Co 3 O 4 /NiFe 2 O 4 nanocomposites from ZIF‐67–Prussian blue analogs significantly enables improved redox activity, faster charge–transfer kinetics, and favors electron transport pathways along with structural robustness. The Co 3 O 4 /NiFe 2 O 4 nanocomposite exhibited a gravimetric capacitance of 678 F g −1 at 0.5 A g −1 in 6 M KOH, six times higher than pristine ZIF‐67. Furthermore, the composite demonstrated a remarkable capacity retention of 87% at 2 A g −1 after 5000 cycles. An asymmetric hybrid supercapacitor fabricated with Co 3 O 4 /NiFe 2 O 4 and activated carbon achieved a high energy density of 42 Wh kg −1 and a power density of 4 kW kg −1 (based on the mass of both electrodes). The supercapacitor also exhibited excellent cycling stability, retaining ∼90% of its initial capacitance after 10 000 cycles when cycled at 2 A g −1 . These findings demonstrate that heterostructure derived multicomponent nanostructures are potential electrode materials for energy storage solutions with high energy–high power.