High‐performance hybrid supercapacitor using NiFe₂O₄/rGO/polypyrrole ternary composite derived from Prussian blue analogs

Abstract The pursuit of energy storage devices with high power and energy density has driven significant advancements in supercapacitor electrode materials. This study develops a ternary NiFe 2 O 4 /rGO/PPy composite derived from Prussian blue analogs to enhance both the energy density and electrochemical stability of supercapacitors. The incorporation of reduced graphene oxide (rGO) and polypropylene (PPy) significantly improves conductivity and electron transport pathways in NiFe 2 O 4 . The ternary NiFe 2 O 4 /rGO/PPy nanocomposite exhibited a gravimetric capacitance of 385 F g −1 at 0.5 A g −1 in 1 M Na 2 SO 4 , five times higher than that of pristine NiFe 2 O 4 under the same three‐electrode configuration. An asymmetric hybrid supercapacitor fabricated with NiFe 2 O 4 /rGO/PPy and activated carbon electrodes achieved a high energy density of 29.2 Wh kg −1 and a power density of 400 W kg −1 (based on the mass of both electrodes). The supercapacitor also exhibited excellent cycling stability, retaining ∼80% of its initial capacitance after 3000 cycles when cycled at 2 A g −1 . These findings demonstrate the potential of this strategy to enable advanced energy storage solutions.