Supercapacitor Electrodes Based on Corn Stalk Binderless Activated Carbon

Abstract

Activated carbon electrodes from cornstalk core waste have been produced using combination of chemical and physical activation for supercapacitor application. Cornstalk was processed into self-adhesive carbon grains. The chemical activation of self-adhesive carbon grains was conducted using 0.4 M KOH at room temperature, and simultaneously followed by carbonized at 600°C in N2 environment, and physical activation in the CO2 environment with difference temperature of 600, 700 and 800°C using a multi-step heating profile. The physical properties of the cornstalk based activated carbon electrode which involve microstructure, functional groups and porosity parameter were evaluated using X-ray diffraction, Fourier transform infrared analysis, and N2 adsorption/desorption isotherm at 77K, respectively. The electrochemical measurement of supercapacitor cells was conducted using cyclic voltammetry technique. The activation temperature of 700°C resulted cornstalk based activated carbon electrode with a higher BET surface area of 826 m2/g and stack diameter of 1.0461 nm, corresponding to higher of specific capacitance of 109 F/g.