Further, a symmetric supercapacitor was fabricated using two same NSHPC-700 electrodes in a neutral aqueous electrolyte of 1 M sodium sulfate electrolyte solution, and displayed a specific capacitance of 204 F g -1 at 0. g -1 , and the pore volume of 0.75, 1.31, and 1.47 cm 3 g -1 , respectively, indicating that temperature is the major factor influencing the SBET, and total pore volume. The XPS analysis of the prepared materials showed the presence of O, and N heteroatoms, which were found to be decreased with increasing temperature owing to the poor thermal stability of nitrogen, and oxygen at high temperatures. The O/N contents in AF-PCMRST-700, AF-PCMRST-800 and AF-PCMRST-900 were estimated as .01/1.34, respectively. The AF-PCMRST-900 electrode in 6 M KOH displayed the highest specific capacitance of 390 F g - 1 at 1 A g -1 , and the capacitance retention of 86.2 %, compared to other electrodes due to large specific area, rich N-doping groups, reasonable pore distribution, and unique porous microrod.