Preparation and Electrochemical Properties of Porous Carbon Nanofiber Electrodes Derived from New Precursor Polymer: 6FDA-TFMB

Abstract

Porous carbon nanofibers (CNFs) with high energy storage performance were fabricated with a single precursor polymer, 6FDA-TFMB, without the use of any pore-generating materials. 6FDA-TFMB was synthesized, electrospun, and thermally treated to produce binder-free CNF electrodes for electrochemical double-layer capacitors (EDLCs). Highly porous CNFs with a surface area of 2213 m2 g−1 were prepared by steam-activation. CNFs derived from 6FDA-TFMB showed rectangular cyclic voltammograms with a specific capacitance of 292.3 F g−1 at 10 mV s−1. It was also seen that CNFs exhibit a maximum energy density of 13.1 Wh kg−1 at 0.5 A g−1 and power density of 1.7 kW kg−1 at 5 A g−1, which is significantly higher than those from the common precursor polymer, polyacrylonitrile (PAN).

Preparation of Porous Carbon Nanofiber Electrodes Derived from 6FDA-Durene/PVDF Blends and Their Electrochemical Properties

“…6FDA-based PIs are considered to be excellent precursor polymers for highly porous carbon [ 10 , 11 , 40 ]. During thermal treatment, the decomposition of bulky fluorinated substituents in the 6FDA unit can generate pores, resulting in a high surface area and high porosity in the resultant CNFs.…”

“…It was also reported that CNFs derived from crosslinked 6FDA–durene exhibited a high specific capacitance of 301 F/g compared to that of non-treated ones (205 F/g) with KOH [ 43 ]. CNFs derived from 6FDA-2-2′-bis(trifluoromethyl) benzidine (TFMB) were also reported, and steam-activated CNFs showed a specific capacitance of 292 F/g at 10 mV/s with KOH [ 11 ]. It seems that the addition of PVDF has a comparable effect on improving surface porosity and energy storage performance with pre- (surface crosslinking of PI nanofibers before carbonization) or post-treatment (steam activation of carbonized PI nanofibers).…”

“…To produce CNFs, polyacrylonitrile (PAN), polybenzimidazole (PBI), aromatic polyimides (PIs), and polyvinylidene fluoride (PVDF) have typically been reported as precursor polymers [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Their copolymers and polymer blends have been also studied as precursors in order to improve the electrochemical properties of the resultant CNFs.…”

“…Moreover, highly porous carbon can be fabricated through the thermal treatment of 6FDA-based PIs since the decomposition of CF 3 – groups can generate a large number of pores. It was reported that CNFs derived from 6FDA-based PIs exhibit a large surface area and high porosity compared to those derived from PAN or PBI with sacrificial polymers [ 10 , 11 ].…”

Polymer Adsorbents vs. Functionalized Oxides and Carbons: Particulate Morphology and Textural and SurfaceCharacteristics

“…Therefore, additional methods, such as small-angle X-ray or neutrons scattering (SAXS, SANS) [ 53 , 54 , 55 , 56 , 57 , 58 ], X-ray diffraction (XRD) [ 59 , 60 , 61 ], high-resolution transmission (HRTEM) and scanning (SEM) electron microscopies [ 59 , 62 ], nuclear magnetic resonance (NMR) spectroscopy with cryoporometry and relaxometry [ 15 , 63 , 64 , 65 ], differential scanning calorimetry (DSC) and thermoporometry [ 66 ], infrared spectroscopy (FTIR), thermogravimetry (TG) and thermoporometry, dielectric relaxation spectroscopy (DRS), thermally stimulated depolarization current (TSDC) and relaxometry, theoretical simulations, etc. [ 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 ] should be used. Besides the textural characteristics, the data of these methods allow one to obtain information on the materials’ behavior under different conditions, which could model real situations related to practical applications.…”