In Situ Nitrogen‐Doped Covalent Triazine‐Based Multiporous Cross‐Linking Framework for High‐Performance Energy Storage

Abstract Porous carbon as an electrode material has attracted extensive attention in the field of energy storage. Herein, to promote the energy density of carbon‐based materials, a class of in situ nitrogen‐doped 3D carbon skeleton with hierarchical pores through the structural evolution of pyridine‐incorporated porous covalent triazine‐based framework (p‐CTFs) is rationally designed and prepared. The controlled microscopic pore structure and nitrogen doping concentration can be achieved by varying the polymerization temperature. The experimental results show that p‐CTF‐800 has a large specific surface area (2795 m 2 g −1 ), a rich nitrogen content (11.82%), and a broad pore size distribution (0.65–5 nm), and exhibited an excellent specific capacitance of 406 F g −1 in three‐electrode system and 245.7 F g −1 in water‐based symmetric supercapacitor. When using ionic liquid 1‐ethyl‐3‐methylimidazolium tetraflfluoroborate as electrolyte, the energy density can reach 77 Wh kg −1 at a power density of 175 W kg −1 , and still remain at 56.4 Wh kg −1 even at a power density up to 8749 W kg −1 . Moreover, p‐CTF‐800‐supercapacitor presents excellent cyclic stability (94% energy retention after 20 000 cycles for IL electrolytes) under current density of 4 A g −1 . These results indicate that as‐prepared p‐CTFs can behave as excellent electrode candidate materials for the future high‐performance energy storage devices.