Synthesis of nitrogen-doped carbon cellular foam with ultra-high rate capability for supercapacitors

Abstract

Three-dimensional (3D) interconnected N-doped porous carbons (NPCs) with different levels of pore structure are synthesized by a template method using MnOx as template and N-enriched pyrrole as carbon source. The fabricated materials show favorable pore size distribution in the range about 3–4 nm and moderate nitrogen content changing from 0.94 to 1.63 at%. Used as electrode material, the NPC originated from the optimum pyrolysis temperature of 750 °C demonstrates the best capacitance performance with a high specific capacitance of about 239.30 F g⁻¹ at 0.5 A g⁻¹. Moreover, it reveals an outstanding rate capability and the specific capacitance reaches 212.90 F g⁻¹ at 10.0 A g⁻¹ (up to 88.97% capacitance retention), as well as excellent cycling stability (∼10% capacitance loss after 5000 cycles) tested in 6 M KOH aqueous solution. Such exquisite performance may be ascribed to a unique combination of high specific surface area, suitable pore size distribution and introduction of nitrogen atoms.