LAUSR

Carbon is the promising candidate served as electrode material for electrochemical capacitors, due to its merits in good electrical conductivity, high surface area and relatively low cost. Pore size distribution is an important factor for carbon based electrode materials. Herein, oxygen-doped hierarchical porous carbon (OPC) was synthesized by a two-step low cost carbonization and KOH activation process of pomelo mesocarp. Oxygen functional groups were introduced to the structure and served as hydrophilizing agent, which highly contributes to the permeation of electrolyte into the inner pores of the OPC material. The as prepared OPC material delivers a superhigh specific surface area at 2378.1 m 2 /g and a large pore volume at 1.13 cm 3 /g. Electrochemical performances of the OPC electrode show a high capacitance of 292 F/g at 0.5 A/g and excellent cycling stability with capacitance retention of 96.41 % over 1000 th cycle at 1 A/g.