Electric double layer capacitors (EDLCs) were fabricated using biomass derived porous activated carbon as electrode material with 1 M H₂SO₄ and VOSO4 added 1 M H₂SO₄ as electrolytes. Here, VOSO₄ was used as redox additive to improve the overall performance of EDLC. As expected, the VOSO₄ electrolyte showed 43% of improved specific capacitance of 630.6 Fg^-1at 1 mA cm^-2 compared to pristine 1 M H₂SO₄ (440.6 F g^-1) due to the contribution of VO²⁺/VO₂ ⁺ redox reaction at the electrode–electrolyte interface. Possible redox reaction mechanism of VO²⁺/VO₂ ⁺ pair is also briefly illustrated. The good cycling performance of 97.57% capacitance retention was observed even after 4000 cycles. For comparison, the polymer gel electrolyte (PVA/VOSO₄/H₂SO₄) was also prepared and then the performance of the fabricated EDLCs was studied. Overall, these findings could open up a simple and cost effective way to improve the performance of EDLCs significantly.