Polymerization-Pyrolysis-Derived\nHierarchical Nitrogen-Doped\nPorous Carbon for Energetic Capacitive Energy Storage

Abstract

Nitrogen-doped porous carbons are attractive electrode\nmaterials\nfor supercapacitors because of their high specific capacitance and\ndesirable surface property. Here, we report a facile polymerization-pyrolysis\nstrategy to construct hierarchical porous carbon, which is rich in\nsurface redox nitrogen species. The polymeric precursor of phenolic\nresin cross-linked with polyaniline is produced by a mild hydrothermal\nprocess. The following calcination procedure yields hierarchical nitrogen-doped\nporous carbon, which presents a large specific surface area of 968.5\nm² g^–1 with multi-scale porous structures\nincluding micro-, meso-, and macropores. It is found that pyrrolic\nnitrogen and oxidized nitrogen are successfully introduced on the\nporous carbon surface, and they can supply extra pseudo-capacitance.\nThe synergy of massive charge storage sites and interconnected ion\ntransport channels enables the hierarchical nitrogen-doped porous\ncarbon to exhibit a high specific capacitance of 320.6 and 250.0 F\ng^–1 in the alkaline electrolyte at current densities\nof 0.5 and 100 A g^–1, respectively. In addition,\nthe assembled symmetrical supercapacitor with organic electrolytes\nshows a huge energy density of 48.9 Wh kg^–1 at a\npower density of 375.0 W kg^–1, with a capacitance\nretention close to 100% after 50,000 cycles.