The cyclic voltammograms of the supercapacitors from biomass-derived and commercially available carbons show typical electrochemical double-layer (EDL) behavior at scan rate of 1 mV.s -1 (Figure ). GP-AC, GR-AC, and BPL-AC maintain the EDL behavior and high charge storage ability also at scan rates of 3 and 5 mV.s -1 (Figure and). S-AC and Y-AC show deviation from ideal EDL behavior as the scan rate increases from 1 mV.s -1 to 5 mV.s -1 . GS-AC shows the maximum deviation from EDL behavior even at 1 mV.s -1 due to high resistance and slow charge transport kinetics of the electrodes. GS-AC was carbonized at 600 o C for 1 h at 6.5 o C.min -1 and activated at 700 o C.min -1 for 1 h at 5.5 o C.min -1 . On the other hand, GP-AC and GR-AC were carbonized at 600 o C for 2 h at 5 o C.min -1 and activated at 800 o C for 2 h at 5 o C.min -1 . The synthesis conditions were modified to achieve a reasonable yield for GS-AC (∼11%). GS activation at 800℃ led to no yield at all. Nevertheless, GS-AC electrodes showed high specific capacitance and high adsorption capacity, comparable to GP-AC and GR-AC during the SSA tests (at constant current of 50 mA.g -1 ), as will be discussed in the later section.