Effects of Sodium Alginate on the Composition, Morphology, and Electrochemical Properties of Electrospun Carbon Nanofibers as Electrodes for Supercapacitors

Abstract

Heteroatoms-doped porous carbon nanofibers (HPCNFs) are fabricated through electrospinning of polyacrylonitrile and poly­(methyl methacrylate) in N,N-dimethylformamide with sodium alginate as additive, followed by pyrolysis. The morphology and composition of the as-fabricated HPCNFs have been characterized comprehensively by a variety of methods, including scanning and transmission electron microscopies, X-ray photoelectron spectroscopy, and other spectroscopic measurements. Supercapacitors are assembled with the as-obtained HPCNFs as electrodes, and their electric capacitance performances are investigated. The supercapacitors show high specific capacitance (253.2 F/g at 0.25 A/g in 1 M H2SO4 aqueous electrolyte), excellent rate capability, and prominent cycling durability (with capacitance maintenance of 99.8% after 10 000 cycles). It has also been illustrated that the heteroatom content and the morphology of porous carbon nanofibers can be simply tuned by varying the content of SA in the precursor solution, which determine finally the electrochemical performances of HPCNFs as the electrodes in supercapacitors.

Template-Free, Self-Doped Approach to Porous Carbon Spheres with High N/O Contents for High-Performance Supercapacitors

“…The value of I D / I G (the intensity ratio of D band to G band) reflects the graphitization degree of carbon-based materials. With the increasing of heat treatment temperature, the I D / I G value slightly decreased from 0.94 (PCS 750 ) to 0.83 (PCS 850 ), revealing enhanced graphitization degree of PCSs …”

“…With the increasing of heat treatment temperature, the I D /I G value slightly decreased from 0.94 (PCS 750 ) to 0.83 (PCS 850 ), revealing enhanced graphitization degree of PCSs. 54 XPS results (Figure 5) reveal that as-prepared materials comprise C, O, and N elements. As increasing carbonization/ activation temperature from 750 to 850 °C, the C contents in PCSs increase from 81.21 to 83.38 wt %, accompanied by a diminished N content from 10.76 to 6.11 wt % and an enhanced O content of 8.03−11.01 wt % (Table 2).…”

Novel mesoporous electrode materials for symmetric, asymmetric and hybrid supercapacitors

“…The CNFs are 1D carbon nanostructures used widely as electrode materials in EDLCs due to their unique properties such as easy processability, light-in-weight, large surface area, mesoporous architecture, good chemical and electrochemical stabilities, etc. The long cycling stability is an added advantage of CNFs based supercapacitor electrodes [72][73][74]. Different strategies are used to synthesize CNFs such as CNFs derived from polymer blends, use of sacrificial polymers in the carbon fiber (CF), use of degradable small molecules in CNFs, etc [75][76][77].…”

Free-Standing, Flexible Nanofeatured Polymeric Films Prepared by Spin-Coating and Anodic Polymerization as Electrodes for Supercapacitors

“…Within this context, a wide variety of electrode materials have been developed. For example, graphene [ 8 , 9 , 10 ], carbon nanotubes [ 11 , 12 , 13 ], and carbon nanofibers [ 14 , 15 , 16 ] are typical EDLC electrode materials, whereas metal oxides [ 17 , 18 , 19 ] and conducting polymers [ 20 , 21 , 22 , 23 ] (CPs) are pseudo-capacitor electrode materials. In general, pseudo-capacitor electrodes exhibit higher capacitance and energy density than EDLC electrodes.…”