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

Abstract 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.