Preparation of hierarchically porous graphitic carbon materials from peanut shell via a facile catalytic activation method for supercapacitor applications

Abstract

In this study, peanut shells are selected as a biomass raw material, and biomass-based hierarchically porous graphitic carbons (PS@FN) are prepared by the synergistic effect of Fe catalysis and KOH activation. The obtained porous graphitic carbon material PS@FN has a large specific surface area of 1664.0 m² g⁻¹ and a good distribution of large-medium-small pore structure. Simultaneously, there is a notable enhancement in the level of graphitization, accompanied by a 13.8 % decrease in the I_D/I_G value. In order to investigate the potential of the samples as supercapacitor electrode materials, the porous graphitic carbon materials are tested for electrochemical properties by the related researchers. In the three-electrode system, the specific capacitance of PS@FN can reach 384.9 F g⁻¹ at a current density of 1 A g⁻¹ under the environment of 6 M KOH electrolyte, and remains as 311.3 F g⁻¹ at 10 A g⁻¹, with a capacitance retention rate of 80.87 %. In the two-electrode system, the energy density of PS@FN is 7.5 W h kg⁻¹ at a power density of 625 W kg⁻¹, and is still maintained at 6.9 W h kg⁻¹ at 3125 W kg⁻¹. A capacitance retention of 98.16 % is obtained after 10,000 charge/discharge cycles.