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

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 NiFe₂O₄/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 NiFe₂O₄. The ternary NiFe₂O₄/rGO/PPy nanocomposite exhibited a gravimetric capacitance of 385 F g⁻¹ at 0.5 A g⁻¹ in 1 M Na₂SO₄, five times higher than that of pristine NiFe₂O₄ under the same three-electrode configuration. An asymmetric hybrid supercapacitor fabricated with NiFe₂O₄/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.