<p>Biomass-derived porous carbons are considered promising supercapacitor electrodes owing to their sustainable precursors, cost-effectiveness, and superior structural features. Using bamboo shoot shells (BSSs) as the precursor, BSS-derived porous carbon was synthesized through a NaOH-assisted hydrothermal process and subsequent activation in air. The impact of hydrothermal temperature and duration on the material’s physicochemical characteristics and subsequent supercapacitor performance is methodically examined in this work. The as-prepared sample (BSSN-160–10) delivers a high specific capacitance of 211.4 F·g⁻¹ at a current density of 1 A·g⁻¹, demonstrating exceptional electrochemical performance. Retaining 101% of its capacitance over 30,000 cycles, the symmetric supercapacitor yields an energy density of 15.15 Wh·kg⁻¹ at a power density of 500 W·kg⁻¹. High energy density, high power density, and exceptional cycling longevity are all achieved by BSS-derived porous carbon in supercapacitor electrodes. Thus these materials offer a compelling candidate solution for green energy storage.</p>