In situ nitrogen-doped mesoporous carbon nanofibers as flexible freestanding electrodes for high-performance supercapacitors

Abstract

Herein we propose a low-cost, one-step synthesis of magnesium hydroxide (Mg(OH)₂) that is deposited on polyacrylonitrile (PAN) nanofibers by electrospinning. Following carbonization and etching, an in situ N-doped mesoporous carbon nanofiber (N-MCNF) network is synthesized. The synthesized flexible network is employed as a freestanding electrode for supercapacitors. The as-constructed supercapacitor based on the N-MCNFs prepared at 900 °C (N-MCNFs-900) can deliver excellent performance with an ultrahigh specific capacitance of 327.3 F g⁻¹ at a current density of 1.0 A g⁻¹, and remarkable cycling stability, e.g., only about 7% loss after 10 000 cycles at a constant high charging–discharging current of 20 A g⁻¹ in 6 M KOH aqueous electrolyte. The flexible network consisting of N-MCNFs-900 as the electrode material with long cycling stability is highly promising for next-generation high-performance supercapacitors.