High Performance Supercapacitors Electrode Based on N-Doped Carbon Nanofibers

Abstract

Supercapacitors (also known as electrochemical capacitors) are considered to be the most promising devices to meet the urgent and pressing requirements of energy storage. Supercapacitive electrode materials, which are strongly related to the high-efficiency storage of energy, have provoked more attentions and interests. Heteroatom doping (nitrogen, oxygen, phosphorus, boron et.al) has been conceived as a promising approach to increase the special surface area, tune pore size distribution, and incorporate pseudo-capacitance. Recently, nitrogen-doped three-dimensional (3D) nanostructured carbon electrode materials have attracted immense interest due to their great potential merits, including enhance the electrical conductivity, surface polarity, wettability and electro-active surface area, provide an additional pseudo-capacitance and achieve high rate performance and good cycling stability. Herein, a simple, eco-friendly, novel, and effective way to fabricate N-doped carbon nanofiber networks (N-CNFs) is studied. The N-CNFs are successfully fabricated through in situ polymerization using pyrrole and ammonium persulfate as the monomer and oxidant, respectively, then followed by pyrolyzed in a nitrogen atmosphere. The fabricated electrode exhibits an excellent reversible specific capacitance of 233.5 F g-1 at the current density of 0.5 A g-1, and a high rate performance of 80.2 % retention at 5 A g−1 in 6.0 mol L-1 KOH electrolyte. The exceptional properties mostly stem from robust redox reactions of N-doping in the CNFs, which providing enhanced pseudo-capacitance. Furthermore, this kind of hybrid doped material could be easily scaled up and represents an alternative promising candidate for an efficient electrode material for supercapacitors.