Preparation and Electrochemical Properties of Carrot-based Hierarchical Porous Carbon

Carrot carbon was used as carbon source,KOH activation method was developed to prepare highly qualified porous carbon with hierarchical pore size distribution and high specific surface area. The morphology and structure of the prepared materials were analyzed by means of scanning electron microscopy (SEM),X-ray diffraction (XRD)analysis,and nitrogen adsorption-desorption. The results showed that the different KOH to carbon ratio would cause different degree of structural changes of the carbon materials. When the alkali to carbon ratio was 2 ∶ 1,the pore structure distribution of the prepared carbon material showed the best with the specific surface area of 3 111. 45 m2 / g and total pore volume of 1. 51 m3 / g. The cyclic voltammetry and constant current charge-discharge tests showed that the specific capacitance of the electrodes prepared under the optimal activation conditions was 486 F / g at 6 mol / L KOH electrolyte and 0. 5 A / g current density,which indicated that the material had good electrochemical performance. When the current density was increased by 20 times,the capacitance retention was 86% of the original,which indicated that the material had good rate performance. The capacitance retention was reserved as 97. 3% after 8 000 test cycles at 10 A / g current density which demonstrated that the material had good stability. The energy density and power density of the water-based supercapacitor device assembled by the carrot-based hierarchical porous carbon electrode plate could reach 14. 67 Wh / kg and 1 000 W / kg. © 2023 Cailiao Daobaoshe/ Materials Review. All rights reserved.