Simultaneous effect of thermal and chemical activation on novel argan pulp-derived activated carbon for high-performance supercapacitors

Abstract

In this paper, we offer new porous activated carbons (PACs) made from waste Argan pulp for use in solid-state supercapacitors. The synthesis is a two-step process of carbonization and KOH activation, with temperatures ranging from 700 to 850 °C and ratios ranging from 1:3 to 1:4. The carbon material obtained exhibits a significant surface area ranging from 2757 to 3235 m2 g−1. The evaluation of electrochemical characteristics in a two-electrode system using a 1 M H2SO4 electrolyte reveals exceptional capacitance and specific energy when subjected to a current density of 125 mAg-1. The AP-800-3 has outstanding performance, with a specific capacitance of 460 F g−1 and a specific energy of 15.98 Wh kg−1. Significantly, this particular PAC has exceptional durability in cycling, as it maintains its full specific capacitance even after undergoing 2500 charge and discharge cycles at a rate of 1 A.g−1. When testing with 6 M KOH and 1 M Na2SO4 electrolytes, the capacitance is found to be lower compared to 1 M H2SO4 (239 F g−1 and 258 F g−1, respectively). The superior performance in 1 M H2SO4 emphasizes the interplay between electrolyte composition, porosity, and appropriate microstructure of the PACs. This study proposes eco-friendly method for selecting supercapacitor electrode materials.The authors acknowledge financial support from the Vice President's Office of the University of Alicante initiatives for Cooperation to Development 2019 and 2020. The UGR-Carbon authors are indebted to Project PID2021-127803OB-I00, which was funded by MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe,” for its financial support of this work. The assistance of the grant Mara Zambrano (RD 289/2021), which was financed by the Next Generation EU program of the European Union, is acknowledged by A. Elmouwahidi