<p>Biomass-derived activated carbon has gained significant attention as a cost-effective and sustainable material for various energy conversion and storage applications. In this work, <i>Typha angustifolia</i>, a relatively underutilized biomass source, was employed as the carbon precursor for supercapacitor electrodes. A mild and less toxic activation method was adopted to process the biomass-derived carbon. The physicochemical properties were analyzed using XRD, Raman, FTIR, and FE-SEM techniques, while the electrochemical behavior of the resulting biocarbon electrodes was evaluated through CV, GCD, and EIS analyses. This study investigates the influence of temperature on biomass-based activated carbon as an efficient, high-performance supercapacitor electrode material. Among the three prepared samples, the activated carbon (AC) treated at 750&#xa0;°C demonstrated excellent performance as a supercapacitor electrode material. The assembled device achieved a high specific capacitance of 375 Fg⁻¹ at a current density of 1 Ag⁻¹, along with an energy density of 52.08 Whkg⁻¹ at a power density of 625 Wkg⁻¹. It also showed strong rate capability with impressive cycling stability, retaining 91.18% of its initial capacitance after 10,000 cycles in a 2&#xa0;M KOH electrolyte. Its superior charge storage characteristics are attributed to the material’s high specific surface area, significant microporosity, and well-optimized pore size distribution.</p>