One-pot synthesis of N-doped hierarchical porous carbon for high-performance aqueous capacitors in a wide pH range

Nitrogen doped porous carbons are the most attractive electrode materials for supercapacitors due to their large surface area and surface pseudocapacitance. Herein, a nitrogen-doped porous carbon with an ultra-high specific surface area of 3709 m(2) g(-1) is synthesized by a simple one-pot polymerization and calcination process. The porous carbon exhibits both high specific capacitance and excellent rate capability in a wide pH range. High specific capacitances of 304.3, 348.0, 185.4 and 298.0 F g(-1) are achieved for the nitrogen-doped porous carbon in 1 M H2SO4, 6 M KOH, 21 m LiTFSI and 1 M Li2SO4 at 2 mV s(-1), respectively. The symmetrical supercapacitor with this porous carbon as the electrodes can deliver a high energy density of 25.9 Wh kg(-1) at a power density of 339.6 W kg(-1) with an operating cell voltage of 1.7 V in 1 M Li2SO4 electrolyte, and a good cycle stability with 84% of its initial specific capacitance remains after 23,000 cycles. The superior electrochemical properties can be attributed to the large specific surface area, well-defined hierarchical pores, and high level of disorder structure for the N-doped carbon material.

Automated summary

Nitrogen-doped porous carbons with ultra-high specific surface area have been successfully synthesized and shown to exhibit high specific capacitance and excellent rate capability in various electrolytes. The porous carbon electrodes in symmetrical supercapacitors demonstrate good cycling stability and high energy density.