Facile synthesis of nitrogen-containing porous carbon as electrode materials for superior-performance electrical double-layer capacitors

Nitrogen-containing porous carbons with numerous micropores were fabricated by pyrolysing polyvinylidene fluoride (PVDF) membrane following potassium hydroxide (KOH) activation at 600–900 °C for 2 h under N₂ atmosphere. The fabricated nitrogen-containing porous carbons have a large specific surface area of approximately 2289 m² g⁻¹, a certain nitrogen content of 1.35 at.% and a favourable hierarchical porous structure possessing a great number of micropores and a part of mesopores. The carbon materials exhibit high specific capacitance of 338 F g⁻¹ at 0.5 A g⁻¹ in a 6 M KOH and outstanding cycling property of 91.6% maintenance at 2 A g⁻¹ after 10000 cycles. An all-solid-state symmetrical supercapacitor with these as-prepared materials as electrodes can deliver energy densities of 21.9 to 10.4 W h kg⁻¹ at power densities from 700.8 to 12910.3 W kg⁻¹. To sum up, the as-obtained porous carbon is a type of potential electrode material for electrical double-layer capacitor.