Salt Template-Derived Fe-N Co-Doped Ultrathin Carbon for Boosted Performance of Supercapacitors

Heteroatoms-doped ultrathin carbon materials hold great promise for electrochemical energy application. Herein, we develop a salt-templating method to prepare three-dimensional Fe-N co-doped carbon (FeNPC) with ultrathin (~ 5-nm-thick) structural feature. The synthetic procedure involves the following steps: First, fabrication of nanoNaCl templates with uniform particle sizes (~500 nm) via one-pot solution synthesis. Second, fabrication of the precursor by encapsulating of NaCl nanoparticles via the in-situ polymerization of pyrrole monomers under vapor atmosphere. Last, FeNPC formation by subsequent pyrolysis and pickling. The optimized sample displays excellent performance as supercapacitors exhibiting 393.5 F g-1 at 1A g-1 in 6 M KOH. Furthermore, the symmetric supercapacitors assembled with the optimized sample show an energy density of 10.45 Wh kg-1 at a power density of 300 W kg-1 and outstanding cycling stability retaining 93% capacitance at 5A g-1 after 10000 cycles.