Synthesis of Nitrogen-Doped Porous Carbon Monolith for Binder-Free All-Carbon Supercapacitors

A nitrogen-doped porous carbon monolith (N-PCM) was synthesized following a simple self-assembly method in a one-pot hydrothermal process. A solution of hexamethylenetetramine (HMT) in formaldehyde and ammonia was used as partial carbon precursor and nitrogen source, respectively. The monolithic polymer was formed through self-assembly of formaldehyde and resorcinol catalyzed by ammonia. After the annealing process, the N-PCM was prepared. The N-PCM with tailorable macrostructure possessed a high specific surface area (1124 m(2) g(-1)), rich porous structure and reasonable N content (up to 2.1 %). Used as binder-free all-carbon supercapacitor electrode, the N-PCM allowed efficient migration of electrolyte ions and electrons, showing a high specific capacitance up to 202 F g(-1) at a current density of 1 A g(-1), and favorable capacitance retention (93.5 % capacitive retention after 5000 cycles) in a 6 M KOH solution. This advanced monolith carbon material with high surface area and controllable morphology produced in a simple and efficient method could be used as a promising electrode material for high-performance supercapacitors.