Polythiophene Grafted onto Single‐Wall Carbon Nanotubes through Oligo(ethylene oxide) Linkages for Supercapacitor Devices with Enhanced Electrochemical Performance

Abstract

Poly(3‐oligo(ethylene oxide))thiophene (PD2ET) with an ethanolamine terminal in the side chain was covalently grafted onto the surface of single‐walled carbon nanotube bundles (PD2ET‐g‐SWCNTs) by using an esterification reaction. The chemical bond between PD2ET and the SWCNTs is confirmed by using various techniques, such as Fourier transform infrared (FTIR), Raman spectroscopy, and X‐ray photoelectron spectroscopy (XPS) analysis. The microstructural and morphological investigation revealed a good distribution of PD2ET on the surface of the SWCNTs, with a thickness of about 2–3 nm. As an electroactive material, the fabricated PD2ET‐g‐SWCNTs electrode demonstrated high capacitive performance in electrochemical tests, in which an efficient specific capacitance of 399 F/g at 1 A/g was obtained from galvanostatic charge/discharge techniques. Furthermore, the long‐term stability investigation of PD2ET‐g‐SWCNTs electrode showed that over 91 % capacitance retention could be retained after 8000 successive charge/discharge cycles. The integrated two‐electrode supercapacitor based on the PD2ET‐g‐SWCNTs hybrid exhibited a high energy density of 22.5 Wh/kg and a power density of 500 W/kg at 0.625 A/g. The enhanced electrochemical behavior of the PD2ET‐g‐SWCNTs hybrid can be ascribed to the contribution of oligo(ethylene oxide), which facilitates ion diffusion and enables a faster charge process, thus rendering high efficiency in supercapacitors.

Organic Supercapacitors as the Next Generation Energy Storage Device: Emergence, Opportunity, and Challenges

“…[107] Zhou et al used oligo linking to attach polythiophene for having crafted composite where direct linking between the material provided good electrical conductivity and they were able to achieve 399 F g À 1 specific capacitance at 1 A g À 1 current. [108] These improvements were not sufficient to compete with the metal oxide-based supercapacitor. Hence other polymers and composites were also tried.…”

“…Zhou et al. used oligo linking to attach polythiophene for having crafted composite where direct linking between the material provided good electrical conductivity and they were able to achieve 399 F g −1 specific capacitance at 1 A g −1 current [108] …”

Conjugated Polymer/Graphene Oxide Nanocomposites—State-of-the-Art

“…The PE-DOT/GO nanocomposite revealed high specific capacitance of 320 Fg −1 . The poly(9-butyl-3,6-di (thien-2-yl)-9H-carbazole)/GO showed specific capacitance of 296 Fg −1 [100,101]. The interactions between the polythiophene and GO through π-π stacking or non-covalent linking have enhanced the electron mobility, capacitance values, and charge/discharge performance [102][103][104].…”

Preparation of flexible and free-standing polypyrrole/graphene film electrodes for supercapacitors

“…Recently, conducting polymers have demonstrated advantages of easy preparation, low density, high conductivity, stable chemical properties and excellent electrochemical properties, so they have broad development prospects in supercapacitors. The main conductive polymer materials for supercapacitors are polypyrrole (PPy), [8][9][10] polyaniline (PANI), 11,12 polythiophene (PTH), 13,14 etc. Among these conductive polymers, PPy is considered to be one of the most promising function modifiers for supercapacitor electrode materials due to its excellent energy-storage ability, high conductivity, and strong hydrophobicity.…”