Abstract
Combining high specific surface area (SSA) and superior electrical conductivity together at bulk state is very important for carbon materials in capacitive energy storage applications. Herein, by applying molten sodium metal to activate natural cotton at a relatively low processing temperature (800°C), we have obtained hierarchically porous graphitic carbon fibers (HPGCFs) with SSA up to 1716m2g−1 and a high degree of graphitization in the bulk state. This is advantageous compared to amorphous carbon fibers obtained by conventional thermal annealing and KOH-activation. The obtained HPGCFs show remarkable energy storage capability (61% capacitance retention from 1 to 60Ag−1). To further increase the capacitance value, anthraquinone (AQ) molecules have been selected to functionalize HPGCFs via π–π stacking interactions. Asymmetric supercapacitors have been assembled using HPGCFs as the positive electrode and AQ-HPGCFs as the negative electrode in aqueous H2SO4 solution. The device presents a large energy density (19.3Whkg−1 in the applied potential range between 0 and 1.2V) and ultrahigh power capability (up to 120Ag−1, a full charge–discharge within 0.8s).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.