Buckypapers of carbon nanotubes and cellulose nanofibrils: Foldable and flexible electrodes for redox supercapacitors. (20th July 2020)

• Record Type: Journal Article
• Authors: Santos, Mayara C.G.; da Silva, Débora R.; Pinto, Paula S.; Ferlauto, Andre S.; Lacerda, Rodrigo G.; Jesus, Wander P.; da Cunha, Thiago H.R.; Ortega, Paulo F.R.; Lavall, Rodrigo L.
• Is Part Of: Electrochimica acta. Volume 349(2020)
• Publication Date: 2020-07-20
• Subjects: Buckypaper -- Redox supercapacitor -- Carbon nanotubes -- Cellulose nanofibrils -- Redox electrolytes; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2020.136241
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: In this work, we report a buckypaper composite with properties suitable for high performance electrodes of redox supercapacitors. The synthesis employs a specific combination of the double- and triple-walled carbon nanotubes (FWCNT) with cellulose nanofibrils (CNF), with dimensions of 20–50 nm in width and lengths of up to several hundred microns. The generated composite (BP/CNT@CNF) preserves the structure of the FWCNTs and ensures greater wettability, without significant damage to electrical conductivity. When compared to a buckypaper produced without CNF, BP/CNT@CNF is completely moldable and flexible, with an increase of about 375% in tensile strength, and 400% in the maximum strain. As electrodes, BP/CNT@CNF is stable in different aqueous redox electrolytes at different pHs containing hydroquinone (HQ in 1.0 M H2 SO4 ), potassium hexacyanoferrate(II) (K₄[Fe(CN)₆] in 3.0 M KOH) and KBr in neutral medium. In all media, excellent capacitance retentions are obtained, evaluated in 12, 000 cycles. The best electrochemical performances are obtained with HQ/H2 SO4 as a redox electrolyte. High specific capacitance values are found from 1 A g −1 (380.8 F g −1 ) to 15 A g −1 (216.1 F g −1 ), with energy and power densities corresponding to 28.2 W h kg −1 and 3974.7 W kg −1, respectively, calculated at electrode level. Graphical abstract: Image 1