Nitrogen-doped porous carbon with a 3D network structure produced from resorcinol-gelatin-formaldehyde co-polymers and its use as an electrode material for supercapacitors

Nitrogen-doped porous carbons (NPCs) with a three-dimensional network structure were prepared by the direct pyrolysis of resorcinol-gelatin-formaldehyde co-polymers, in which the biomacromolecule, gelatin acted as a nitrogen precursor. Their electrochemical properties as the electrodes of supercapacitors were evaluated with a three-electrode system. Since gelatin can affect the interfacial energy of the reaction liquid, the morphology of the co-polymers was changed into a three-dimensional framework consisting of small spheres. The nitrogen content of the NPCs increases from 1.04 to 2.03 wt% with the mass ratio of gelatin to resorcinol from 0.1 to 0.4. Their specific capacitance increases to 149 F·g^-1 with increasing nitrogen content and levels off when the nitrogen content is above 1.46%. After activation with water, the NPC has a high specific capacitance of 228 F·g^-1,and a specific surface area and nitrogen content of 1 174 m²·g^-1 and 1.51 wt%, respectively.