sample. The XPS measurement of YPC-4 showed the presence of oxygen, and nitrogen heteroatoms with 46.42, and 0.33 wt%, respectively. The electrochemical properties of YPC were analysed using a three-electrode system in 6 M KOH electrolyte, and YPC-4 electrode showed the maximum specific capacitance of 423.2 F g -1 at 0.5 A g -1 , and the capacitance retention of 96.4% was observed after 10000 continuous cycles. In addition, a symmetrical supercapacitor was assembled using YPC-4 electrode in 6 M KOH electrolyte, and obtained the specific capacitance of 387.3 F g -1 at 0.5 A g -1 , and presented a high energy density of 13.45