The growing demand for efficient and sustainable energy storage has intensified interest in green materials known for their high-power density. In this work, we evaluated the electrochemical and electrical performance of coin-cell supercapacitors with activated carbon electrodes from palm kernel shell. Two activated carbons were obtained using KOH and ZnCl2 as activating agents at 700 °C and then superficially modified with nitric acid. The KOH-activated carbon electrodes showed the highest specific surface area (1181 m2 g−1) and the best electrochemical behavior, reaching an average gravimetric capacitance of 56. ± 9.2 F g−1. The coins were characterized electrically by series and parallel arrangements, yielding specific energy and specific power densities of 2.6 Wh kg−1 and 475 W kg−1, and 1.8 Wh kg−1 and 353 W kg−1, at 0.001 A and 0.75 V for parallel and series arrangements, respectively.
Gaviria et al. (2026) studied this question.