LAUSR

We proposed a simple strategy of one-pot carbonization, activation and nitrogen-doped processes to prepare biomass-derived nitrogen-doped porous carbon (NPC-K) by using well-sourced dumpling flour as carbon precursor, urea as nitrogen precursor and KOH as activation agent. In this process, the combination of KOH and urea was used to construct a highly porous structure because of their synergistic effect. The as-prepared NPC-K exhibited honeycomb-like porous structure, large specific surface area (2853.6 m2 g−1) and moderate nitrogen content. Therefore, the NPC-K displayed maximum specific capacitance of 311 F g−1 at 1 A g−1, outstanding rate capability and long lifetime of 10000 cycles in 6M KOH. Furthermore, NPC-K based symmetrical supercapacitor presented a high energy density of 15.92 Wh kg−1. These results are superior to many previously reported carbon materials.