N‑doped Hierarchical Mesoporous Carbon from Mesophase Pitch and Polypyrrole for Supercapacitors

N-doped hierarchical mesoporous carbons have been fabricated by using mesophase pitch (MP) as a carbon precursor and polypyrrole as a nitrogen resource through the MCM-48 template. Carbonization temperature plays a key role in the morphology, mesoporous structure, and electrochemical properties of N-doped porous carbons (NPCs). At an appropriate carbonization temperature (700 °C), as-prepared NPC-700 exhibits rich nitrogen content (4.48 wt %), medium specific surface area (495.9 m² g^–1), and high specific capacitance of 232.2 F g^–1 at a current density of 2 A g^–1 in a three-electrode system. Due to the generation of pseudocapacitance, the specific capacitance of NPC-700 is 53.6 F g^–1 higher than that of PC-700 without polypyrrole. In addition, NPC-700 shows high specific capacitance of 110.6 F g^–1 at a current density of 0.2 A g^–1, a good capacitance retention of 77.8% at the current density of 5 A g^–1, and the large energy density of 15.30 Wh kg^–1 at a power density of 399.9 W kg^–1 in a two-electrode system. This work provides a novel example of how N-doped porous carbons derived from mesophase pitch and polypyrrole can be used as a promising electrode material for potential energy storage applications.