A General Metal Acetate-Assisted Alcohol Thermal Strategy to Fabricate Flexible Carbon Nanofiber Film for Supercapacitor

Abstract

Flexible carbon nanofiber film (CNF) has drawn tremendous attention recently due to their fascinating properties. However, CNF prepared by conventional methods is fragile and easily broken. Therefore, a general approach for synthesizing flexible CNF is urgently needed. Herein, we report a metal acetate-assisted alcohol thermal (MAA) method for the preparation of flexible CNF. The MAA is a general and scalable method which can overcome the shortcomings of the pre-oxidation method, and more than 15 different flexible CNFs are successfully prepared. In this method, polyacrylonitrile (PAN) film is first prepared through an electrostatic spinning process, and then cyclized polyacrylonitrile (CPAN) film with high-temperature-resistant trapezoidal structure is formed after MAA treatment. The unique structure of CPAN will help in maintaining its flexibility to produce flexible CNF during carbonization at elevated temperature. To explore their potential in flexible devices, a supercapacitor made of flexible CNF-Zn is investigated, it shows an energy density of 11.5 Wh kg-1 at 500 W kg-1, and has a capacitance retention rate of 97.2% even after 10,000 charge-discharge cycles. Our findings demonstrate that the MAA method could not only prepare flexible CNF for energy storage devices, and it also has potential application prospects in other fields.