LAUSR

Abstract Design and preparation of high N-doped content biomass-derived hierarchical porous carbon with appropriate pores size distribution and high electrical conductivity draw extensive research attention for supercapacitors. Herein, N-doped mesopore-dominated hierarchical porous graphitic carbons PG/PEI-CNi and PG/urea-CNi are successfully synthesized based on a facile “in-situ template catalyst formed-removed” method, in which the corresponding mixture of peach gum/polyethylenimine/NiCl2 and peach gum/urea/NiCl2 are treated with hydrothermal and carbonization process, respectively. As-prepared PG/PEI-CNi and PG/urea-CNi possess high N-doped content (8.7 and 8.4 at. %), high specific surface area (875.9 and 1161.4 m2 g−1) and excellent electronic conductivity (10.08 and 11.43 S cm−1). The PG/PEI-CNi and PG/urea-CNi exhibit high capacitance of 369 and 426 F g−1 at 0.5 A g−1 and excellent capacitance retention of 95.13% and 97.09% at 20 A g−1 after 10000 cycles, respectively. Moreover, PG/PEI-CNi and PG/urea-CNi assembled symmetric supercapacitors display excellent energy density of 25.76 and 30.28 W h kg−1 at power density of 180 W kg−1 in 1 M Na2SO4 electrolyte, respectively. The proposed “in-situ template catalyst formed-removed” method is prominent in the preparation of high-performance electrode materials for energy conversion/storage devices.