<p>Developing supercapacitor electrodes that combine high energy density, fast charge–discharge capability, and long-term stability remains a critical challenge for advanced energy storage. Herein, ZnFe₂O₄–SiO₂ reinforced PVA/PVP nanocomposites with different filler contents (1–9 wt%) were synthesized and evaluated as supercapacitor electrode materials. Structural and morphological analyses confirmed that ZnFe₂O₄–SiO₂ incorporation enhanced the amorphous character of the polymer matrix, suppressed nanoparticle aggregation, and produced a more open, homogeneous microstructure favorable for electrolyte accessibility. In 3 M KOH, the optimized composition (4 wt% filler) delivered a high specific capacitance of 566 F g⁻¹ at 2 A g⁻¹, nearly 2.7 times that of the pristine PVA/PVP electrode (206 F g⁻¹), while retaining 200 F g⁻¹ at 4 A g⁻¹. It also achieved an energy density of 78.61 Wh kg⁻¹ at 1000 W kg⁻¹ (27.78 Wh kg⁻¹ at 2000 W kg⁻¹) with ~ 79% capacitance retention after 5000 cycles. These values are comparable to or exceed those of many reported ZnFe₂O₄-based hybrid electrodes, achieved without conductive substrates such as carbon cloth or graphene. The enhanced performance stems from synergy between polymer blending, ferrite pseudocapacitance, and SiO₂-assisted dispersion, highlighting polymer–oxide hybrids as scalable, efficient electrodes for next-generation supercapacitors.</p>