respectively. The XPS analysis confirmed the presence of O, and N heteroatoms in SZE2-600 sample. The SZE2-600 electrode showed the highest specific capacitance of 550 F g -1 at 1 A g -1 current density, and 98.9% of capacitance retention after 1000 cycles for a three-electrode system with 1 M H2SO4 electrolyte. Similarly, a cell capacitance of 275 F g -1 at 1 A g -1 , and the energy density of 13.2 W h kg -1 at a power density of 596 W kg -1 was observed for twoelectrode system in 1 M H2SO4 electrolyte. Upon the incorporation of 0.01 M hydroquinone (HQ), as a redox additive to the 1 M H2SO4 electrolyte, a high specific capacitance of 1392 C g -1 , and 658 C g -1 was achieved in three-electrode, and two-electrode system, respectively, along with a cyclic stability of 77% retention after 5000 cycles. For two-electrode configurations of SZE2-600 electrode in the mixture of 0.01 M HQ with 1 M H2SO4 electrolyte, the energy density of 32 W h Kg -1 was gained at 2175 W Kg -1 , which is much higher than that of 1 M H2SO4 electrolyte. The electric double layer, and the faradaic reactions were appeared to be incorporated in the capacitive property through the integration of redox-active mediator HQ with H2SO4, and resulted in the improved capacity, as a well energy density performances x (where x refers to the carbonization temperature). For comparative purposes, peach gum alone was carbonized at 700 ˚C. In this study, Mn (CH3COO)2 was used as a graphitization catalyst during the carbonization of carbon precursors, and CO(NH2)2 was the main source of nitrogen. The NLPC -700 exhibited the highest SBET of 1372 m 2 g -1 , compared to NLPC-600 (965 m 2 g -1 ), NLPC-800 (1008 m 2 g -1 ), and PC-700 (8.6 m 2 g -1 ). The N, O heteroatoms determined by XPS analysis in NLPC-700 sample were 14.04, and 9.53 %, respectively. The NLPC-700 electrode exhibited a higher mass specific capacitance of 402 F g -1 at 0.5 A g -1 in 6.0 M KOH, and long cycle stability with a capacitance retention of 99.5% after 10000 cycles.