A hydroquinone mediated PVA–H₂SO₄ gel electrolyte (PHHQ) and activated carbon from bio-waste were prepared for supercapacitor fabrication. PHHQ delivered a higher capacitance (941 F g^-1 at 1 mA cm^-2) and energy density (20 Wh kg^-1 at 0.33 W g^-1) than the PVA–H₂SO₄ gel electrolyte (425 F g^-1 at 1 mA cm^-2, 9Wh kg^-1 at 0.33 W g^-1).