Preparation and Characterization of Peasecod-Based Activated Carbons as Electrode Materials for electrochemical double-layer capacitors

Abstract

Activated carbons for electrochemical double-layer capacitor electrodes were prepared from peasecod-based carbons using ZnCl2 or KOH as activating agents. The pore structures of the prepared activated carbon materials were characterized using N2 adsorption. The specific surface area of the peasecod-based carbon materials increased obviously from 1.69 m2·g-1 to 2237 m2·g-1 by KOH activation and to 621 m2·g-1 by ZnCl2 treatment. The electrochemical properties of the prepared peasecod-based activated carbon materials were evaluated by cyclic voltammetry and galvanostatic charge-discharge, and a specific capacitance as high as 297.5 F·g-1 in 6 mol·L-1 KOH aqueous electrolyte was obtained for the KOH-treated carbon material. Additionally, the KOH-activated peasecod-based carbon material showed excellent long-term charge-discharge cycle stability and a 8.6% decrease in the specific capacitance was observed at a high current density of 5 A·g-1 after 500 cycles. © Editorial office of Acta Physico-Chimica Sinica.