Free-standing cross-linked activated carbon nanofibers with nitrogen functionality for high-performance supercapacitors

Abstract

Flexible, heteroatoms-rich activated carbon nanofibers with fascinating cross-linked architectures are successfully gained in a facile and controllable way via electrospinning polyacrylonitrile (PAN) /dicyandiamide (DICY) composite nanofibers followed by carbonation and a CO 2 activation process. The unique inter-bonded structures and heteroatoms contents could be easily controlled by adjusting the preoxidation temperature applied in the calcining procedure and the addition of DICY. Significantly, the resultant samples display hierarchical pores with micro/meso/macropores, abundant N, O species doped and unique fiber-fiber interconnections, which considerably boost the electrochemical properties. As an electrode material, the activated N-doped cross-linked carbon nanofibers (ANCLCNFs) show a high capacitance of 323 F g −1 with a current density of 0.5 A g −1 , excellent rate capacity (230.1 F g −1 at 20 A g −1 ) and long-term duration (over 95% after 10000 cycles). Furthermore, the symmetrical supercapacitor delivers a maximum energy density of 14.3 Wh kg −1 at a power density of 162.5 W kg −1 .

Design of Ultra‐Microporous Carbons by Interpenetrating MF Prepolymer into PAAS Networks at Molecule Level for Enhanced Electrochemical Performance

“…The results show that the electrode has favorable kinetics and high power capacitance performance in the KOH electrolyte. The energy density and power density of the device is summarized in the Ragone plot of Figure f, which shows a high energy density of 17.13 Wh kg −1 at the power density of 900 W kg −1 , and much higher than other previously reported materials such as ANCLCNFs, NFMCNFs, C‐blank, Z‐HPAC, CLCNF/PANi, HGPC‐A, N,S‐GLC, NPCs and other carbon materials related symmetrical devices . In contrast, the energy density of the device in KOH solution is only 7.15 Wh kg‐1, which is less than half that in Na 2 SO 4 solution, and smaller in H 2 SO 4.…”

“… The devices: (a) CV curves in 6 M KOH, (b) CV curves in 1 M Na 2 SO 4 , (c) CV curves in 1 M H 2 SO 4 , (d) electrochemical impedance spectroscopy, (e) bode plots (inset is the time constants, τ) in different electrolytes, and (f) Ragone plot in different electrolytes and the comparison with other reported works ANCLCNFs, NFMCNFs, C‐blank, Z‐HPAC, CLCNF/PANi, HGPC‐A N,S‐GLC, NPCs …”

Molten salt-confined pyrolysis towards carbon nanotube-backboned microporous carbon for high-energy-density and durable supercapacitor electrodes

“…Neat MPCs in figure 5(a) exhibited a weak and broad diffraction pattern at 2θ=24.5°, which was assigned to (002) plane of carbon lattices, suggesting the nature of amorphous carbon of MPCs [25]. When CNTs are introduced to form the CNT-MPC, typical graphitic (002) diffraction pattern shifted to 25.6°and a low-intensity (100) diffraction pattern at 42.6°w as observed, implying the existence of a highly graphitic carbon of CNTs and MPCs [26,27]. No diffraction patterns ascribing to LiCl and KCl were observed from XRD results.…”

Porous Carbons Prepared from Polyacrylonitrile Doped with Graphitic Carbon Nitride or Melamine for Supercapacitor Applications

“…[16] Using dicyandiamide as both nitrogen additive and cross-linking agent, heteroatoms-rich activated carbon nanofibers with cross-linked architectures were successfully obtained from polyacrylonitrile (PAN)/dicyandiamide composite nanofibers. [17] The heteroatom contents could be easily controlled with the addition of dicyandiamide, and the highest specific capacitance of 323 F/g at 0.5 A/g was achieved by the sample added with a maximum dicyandiamide. Plasma treated graphite oxide (GO) with a high nitrogen content of 12.8 wt% was synthesized by using melamine and solution plasma for supercapacitor electrode applications.…”

“…Compared with graphene fibers (GFs), the NGFs showed improvement in capacitance, 709.5 mF/cm 2 at 0.1 mA/cm 2 , while the capacitance value of GFs was 379.5 mF/cm 2 [16] . Using dicyandiamide as both nitrogen additive and cross‐linking agent, heteroatoms‐rich activated carbon nanofibers with cross‐linked architectures were successfully obtained from polyacrylonitrile (PAN)/dicyandiamide composite nanofibers [17] . The heteroatom contents could be easily controlled with the addition of dicyandiamide, and the highest specific capacitance of 323 F/g at 0.5 A/g was achieved by the sample added with a maximum dicyandiamide.…”