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

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.