ULTRA-LONG CARBON NANOTUBE PAPER AS AN ELECTRODE MATERIAL FOR SUPERCAPACITORS

This study presents the development and comprehensive investigation of flexible electrode materials based on ultra-long double-walled carbon nanotubes (DWCNTs) for supercapacitor applications. The raw nanotubes were initially purified and grounded in an aqueous solution to obtain homogeneous dispersions. The dispersions were subjected to vacuum filtration, producing a flexible paper-like material. This method, due to the effect of mechanical interweaving of long DWCNTs, eliminates the need for a binder and thereby allows to preserve the material's high electrical conductivity. In order to improve the electrophysical properties, as well as increase the capacitance and physicochemical characteristics of the DWCNT paper, the deposition of dispersions with the addition of conductive components was carried out. The effect of additives, such as thermally expanded graphite, activated carbon, acetylene black and single-walled carbon nanotubes manufactured by OCSiAl has been studied. The obtained samples of paper were compacted using roller pressing to enhance mechanical strength and density and used as electrodes in supercapacitors. During electrochemical testing, all electrode samples are stable in a 38 wt.% H2SO4 electrolyte and show capacitor-like recharging behavior. The pure DWCNTs electrodes (without additives) exhibit a specific surface area of 239 m2/g, electrical conductivity of (3.1 ± 0.6) 104 S/m and a specific capacitance of 9 F/g per total weight of both electrodes. These results highlight the potential of the developed materials for creating flexible energy storage applications. For composite electrodes (DWCNTs + conductive additives) the most pronounced positive effect is achieved in a combination with the high-surface-area additives, namely activated carbon and single-walled carbon nanotubes. The introducing of these additives allows to increase the capacitance of the electrode material, as well as to obtain a material with the pronounced retention of discharge specific capacitance at higher discharge rates. For citation: De V.V., Filimonenkov I.S., Urvanov S.A., Kazennov N.V., Karaeva A.R., Mordkovich V.Z. Ultra-long carbon nanotube paper as an electrode material for supercapacitors. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 9. P. 43-52. DOI: 10.6060/ivkkt.20256809.5y.