▎ 摘　　要

In this paper, we developed a simple strategy for preparing three-dimensional porous carbon from xylose mother liquor for high-performance supercapacitors. Through simple regulation of activation temperature, the porous carbon prepared under optimized conditions have a perfect honeycombed structure with fewer layers and co-existing macropores, mesopores and micropores. The product also has high content of self doped hetero-atoms of O (10.2 at%) and N (0.5 at%). The constructed supercapacitors based on this porous carbon exhibited excellent performance with fantastic specific capacitance of 544 F/g at 0.5 A/g, excellent rate performance of 260 F/g at 20 A/g, as well as long cycle stability of 90.2% capacitance retention after 10000 cycles at 10 A/g in 6 M KOH in three-electrode systems. Notably, symmetric supercapacitors exhibited energy density of 22.3 Wh kg(-1) at a power density of 448 W kg(-1) in the aqueous electrolyte Na2SO4, and a even higher specific energy density of 42.8 Wh kg(-1) was achieved at a high power density of 749.8 W kg(-1) in the organic electrolyte Et4NBF4.