A thin carbon nanofiber/branched carbon nanofiber nanocomposite for high-performance supercapacitors

Abstract

Thin carbon nanofibers (TCNFs) hanging on branched carbon nanofibers (3D TCNF/CNF) with an N-doping level up to 8.7 at% for high-performance supercapacitors are designed and synthesized. TCNF/CNF shows a 3D hierarchical porous structure, a large surface area, abundant ionic-channels, and a great number of electrochemically active sites by N-doping. Because of the multiple synergistic effects of these features, the supercapacitors (SCs) based on TCNF/CNF show a remarkably excellent electrochemical behavior with a high specific capacitance of 224 F g⁻¹. After 50 000 cycles of charge/discharge, 92% of the initial capacitance value is retained in 1.0 M H₂SO₄ electrolyte. Moreover, the TCNF/CNF-based SCs show low internal resistance, leading to a high power density with a relatively high energy density.