Fabrication and electrochemical characterization of polyimide‐derived carbon nanofibers for self‐standing supercapacitor electrode materials

Abstract

We report the electrochemical performance of aromatic polyimide (PI)‐based carbon nanofibers (CNFs), which were fabricated by electrospinning, imidization, and carbonization process of poly(amic acid) (PAA) as an aromatic PI precursor. For the purpose, PAA solution was electrospun into nanofibers, which were then converted into CNFs via one‐step (PAA‐CNFs) or two‐step heat treatment (PI‐CNFs) of imidization and carbonization. The FTIR and Raman spectra demonstrated a successful structural evolution from PAA nanofibers to PI nanofibers to CNFs at the molecular level. The SEM images revealed that the average diameter of the nanofibers decreased noticeably via imidization and carbonization, while it decreased slightly with increasing the carbonization temperature from 800 °C to 1000 °C. In case of PI‐CNF carbonized at 1000 °C, a porous structure was developed on the surface of nanofibers. The electrical conductivity of PI‐CNFs, which was even higher than that of PAA‐CNFs, increased significantly from 0.41 to 2.50 S/cm with increasing the carbonization temperature. From cyclic voltammetry and galvanostatic charge/discharge tests, PI‐CNF carbonized at 1000 °C was evaluated to have a maximum electrochemical performance of specific capacitance of ~126.3 F/g, energy density of ~12.2 Wh/kg, and power density of ~160 W/kg, in addition to an excellent operational stability. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47846.

Polyacrylonitrile/polyvinyl alcohol‐based porous carbon nanofiber electrodes for supercapacitor applications

“…Electrospinning technique is the effective, common, versatile, and relatively simple method to manufacture polymer nanofibers 40‐42 . Although lignin, 43‐45 cellulose, 46,47 polybenzimidazole, 48,49 and polyimide (PI) 48,50‐52 can be used as raw material, polyacrylonitrile (PAN) 5,17,33,36,37,53‐55 is the most common polymer precursor in CNF production due to easy electrospinnability and high carbon yield. CNF material is obtained after stabilization of PAN nanofibers in the oxygen atmosphere at moderate temperatures (~200°C‐300°C) and carbonization in the inert atmosphere (nitrogen, argon, etc) at high temperatures (~ 900°C‐1500°C) 56 …”

Poly(azomethine ether)‐derived carbon nanofibers for self‐standing and binder‐free supercapacitor electrode material applications

“…The electrochemical properties of CNFs, which were derived from different polymeric precursors via electrospinning and carbonization, are compared in Table 2. As a result, it was found that the electrochemical performance, such as specific capacitance, energy density and power density of PAME‐derived CNFs is even higher than or comparable to other CNFs fabricated from polyacrylonitrile (PAN), 34‐36 polyacrylonitrile/poly(methyl methacrylate) (PAN/PMMA) blends, 37,38 polybenzimidazole (PBI), 39 alkaline lignin/poly(vinyl alcohol) (Lignin/PVA) blend, 40 phenolic resin, 41 polyimide (PI), 42 etc. It is conjectured that the excellent electrochemical performance of PAME‐derived CNFs stems from the synergistic effects of nitrogen self‐doping, good wettability to electrolyte, and high electrical conductivity.…”

Poly(Ether Amide)-Derived, Nitrogen Self-Doped, and Interfused Carbon Nanofibers as Free-Standing Supercapacitor Electrode Materials

“…Electrospinning followed by carbonization is considered as a facile, cost-effective, and scalable process to fabricate continuous carbon nanofibers (CNFs) with designed microstructures. − Electrospinning is a simple method to produce a 2-dimensional nonwoven web of fibers with submicron- or nanoscale diameters by spraying polymer solutions or melts in an electric field. Accordingly, a variety of polymeric materials, such as polyacrylonitrile (PAN), − poly­(acrylonitrile- co -vinyl imidazole) (P­(AN- co -VIM)), polyimide (PI), , poly­(azomethine ether) (PAME), polybenzimidazole (PBI), poly­(vinyl chloride) (PVC), etc.…”

“…22−30 Electrospinning is a simple method to produce a 2-dimensional nonwoven web of fibers with submicron-or nanoscale diameters by spraying polymer solutions or melts in an electric field. Accordingly, a variety of polymeric materials, such as polyacrylonitrile (PAN), 31−37 poly(acrylonitrile-covinyl imidazole) (P(AN-co-VIM)), 38 polyimide (PI), 27,39 poly(azomethine ether) (PAME), 30 polybenzimidazole (PBI), 40 poly(vinyl chloride) (PVC), 41 etc. have thus been adopted as precursors of binder-free and self-supporting CNFbased electrode materials.…”