Nitrogen‐Doped Hierarchically Porous Carbon Materials with Enhanced Performance for Supercapacitor

Hierarchical porous carbon (HPC) with a high specific surface area is a promising material for supercapacitors, owing to its effective ion diffusion paths and low transport resistance. Herein, a nitrogen‐doped hierarchical porous carbon (NHPC) material was successfully synthesized from a gelatin and graphene oxide composite through a combined solvation volatilization/nano‐CaCO 3 template/KOH activation method. The obtained NHPC exhibits a large surface area ( S BET =1091 m 2 g −1 ) as well as a combination of electrical double layer capacitance and pseudocapacitance behavior. Benefiting from the advanced synergistic effect of the nitrogen‐doped property and the hierarchically porous structure, NHPC shows a specific capacitance of 234 F g −1 at 0.5 A g −1 in a three‐electrode system. Moreover, a supercapacitor based on NHPC exhibits an excellent cycle life (retaining>98 % after 5000 cycles) and a high energy density up to 9.43 Wh kg −1 .