Hierarchically porous carbon nanofibers containing numerous heteroatoms for supercapacitors

In this study, hierarchically porous carbon nanofibers (HPCNFs) containing numerous electroactive heteroatoms are prepared by controlling carbonization and chemical activation. The HPCNFs have a large surface area of 2862.1 m 2 g −1 , hierarchical porous structure, and 20.6 at% electroactive oxygen atoms. These HPCNFs exhibit excellent electrochemical performance, and their thermal treatment with melamine results in nitrogen-doped HPCNFs (N-HPCNFs) with 9.1 at% nitrogen and improved electrical property (1.8 × 10 2 Ω □ −1 ). The electrochemical performance of N-HPCNFs is better than that of HPCNFs, displaying specific energy of 113 Wh kg −1 , specific power of 105 kW kg −1 , and stable cycle life of over 5000 cycles.