Highly stable performance of supercapacitors using microporous carbon derived from phenol–melamine–formaldehyde resin

Abstract

A series of microporous carbons were prepared by simple carbonization and activation of phenol–melamine–formaldehyde resin. The morphology, surface area, and elemental composition of the samples were investigated by scanning electron microscope, Brunauer–Emmett–Teller measurement, Raman spectra, and elemental analysis, respectively. Electrochemical characteristics were evaluated by cyclic voltammograms, galvanostatic charge/discharge, and electrochemical impedance spectroscopy measurements in 6.0 mol L−1 KOH. The microporous carbon activated by KOH presented a high specific capacitance of 202 F g−1 at a scan rate of 2 mV s−1. Furthermore, the KOH-activated microporous carbon electrode exhibited durable operation, the total loss of capacitance after 20,000 cycles is 2% at a current density of 500 mA g−1. The good electrochemical performance of the activated carbon was ascribed to well-developed micropores, high surface area, larger pore volume as well as oxygen groups.