2018/10/26 by Evgeny Senokosa, Evgeny Senokos, Moumita Ranaa +5 · 5 citations
Chemistry · Materials Science · Physics and Astronomy · #Carbon nanotube #Chemical engineering #Chemistry #Composite material #Conducting polymers and applications #Contact angle #Dielectric spectroscopy #Electrochemistry #Electrode #Electrolyte #Graphene research and applications #Materials science #Nanotechnology #Raman spectroscopy #Supercapacitor #Supercapacitor Materials and Fabrication #Surface modification #X-ray photoelectron spectroscopy #cond-mat.mtrl-sci #physics.app-ph
paper · pdf · doi:10.1016/j.carbon.2018.10.082
published as Carbon 2019, 142, 599-609 · 23 pages, 9 figures
openalex publication_date 2018/10/26 · openalex created_date 2018/11/02 · arxiv created 2020/08/12 · arxiv updated 2020/08/13 · openalex updated_date 2026/08/05
Chemical functionalization of nanocarbons is an important strategy to produce electrochemical systems with higher energy/power density by generating surface functional groups with additional faradaic contribution, by increasing their surface area and correspondent capacitive contribution and by improving compatibility with aqueous electrolytes and other active materials, such as pseudocapacitive metal-oxides. Here we present an electrochemical method to simultaneously swell and functionalize large electrodes consisting of fabrics of macroscopic fibers of carbon nanotubes that renders the material hydrophilic and produces a substantial increase of specific capacitance and energy density in aqueous electrolytes. Through in-depth characterization of the carbon nanotube fibres (CNTF) by Raman spectroscopy, transmission electron microscopy, X-ray photoelectrocn spectroscopy (XPS) and small-angle X-ray scattering (SAXS) we identify various contributions to such improvements, including surface oxidation, tubular unzipping, debundling and inter-bundle swelling. Changes in hydrophilicity of functionalized CNTF are determined by analyzing the dynamics of spreading of polar and nonpolar liquids in the electrode. The extracted contact angles and polar and dispersive surface energy components for different treatment conditions are in agreement with changes in dipole-moment obtained by XPS. Finally, functionalized CNTF electrodes were employed in current collector-free solid flexible supercapacitors, which show enhanced electrochemical properties compared to as-produced hydrophobic ones.