Polymerization-Pyrolysis-Derived Hierarchical Nitrogen-Doped Porous Carbon for Energetic Capacitive Energy Storage

Nitrogen-doped porous carbons are attractive electrodematerialsfor supercapacitors because of their high specific capacitance anddesirable surface property. Here, we report a facile polymerization-pyrolysisstrategy to construct hierarchical porous carbon, which is rich insurface redox nitrogen species. The polymeric precursor of phenolicresin cross-linked with polyaniline is produced by a mild hydrothermalprocess. The following calcination procedure yields hierarchical nitrogen-dopedporous carbon, which presents a large specific surface area of 968.5m(2) g(-1) with multi-scale porous structuresincluding micro-, meso-, and macropores. It is found that pyrrolicnitrogen and oxidized nitrogen are successfully introduced on theporous carbon surface, and they can supply extra pseudo-capacitance.The synergy of massive charge storage sites and interconnected iontransport channels enables the hierarchical nitrogen-doped porouscarbon to exhibit a high specific capacitance of 320.6 and 250.0 Fg(-1) in the alkaline electrolyte at current densitiesof 0.5 and 100 A g(-1), respectively. In addition,the assembled symmetrical supercapacitor with organic electrolytesshows a huge energy density of 48.9 Wh kg(-1) at apower density of 375.0 W kg(-1), with a capacitanceretention close to 100% after 50,000 cycles.