2024

Electrochimica Acta

Journal year: 2024 | Journal volume: vol. 492

scientific article

english

EN Self-standing films from single-walled carbon nanotubes (SWCNTs) were successfully used as electrochemical capacitors’ (ECs) electrode material, which exhibited state-of-the-art characteristics. The surface of SWCNTs was modified by iodonium salt molecules that substantially and permanently improved their electrical conductivity. The addition of pyridinium iodine chloride salt (IPyCl) quadrupled the value of the electrical conductivity of the SWCNT film, which reached values as high as 1022 S cm-1. Subsequently, the electrochemical performance of the newly designed self-standing SWCNTs with deposited IPyCl in aqueous neutral 1 M Li2SO4 and redox-active 1 M KI electrolytes was thoroughly analyzed. Because redox activity of iodine species was observed mainly on the positive electrode, activated carbon with a developed surface area was used as a negative electrode to balance the faradaic charge. Due to the notable stability of iodonium salt dopant (instead of labile halogen-containing compounds typically used for SWCNT doping), robust charge/discharge performance of EC was demonstrated (> 10 000 cycles) in Li2SO4 electrolyte. Moreover, a significant improvement of capacitor metrics (from 49 to 75 F g-1) was obtained when electrodes modified by previously unexplored iodonium salt were utilized in 1 M KI electrolyte. Extensive analysis of the obtained data led to the elucidation of the doping mechanism responsible for the aforementioned achievements. The novel SWCNT-based electrodes enhanced with iodonium salt are auspicious materials, which can be used to build EC systems of appreciable capacitance.

04.05.2024

144386-1 - 144386-10

10.1016/j.electacta.2024.144386

https://www.sciencedirect.com/science/article/pii/S0013468624006285?via%3Dihub

Article number: 144386

100

5,5 [List 2023]