Design and synthesis of novel electroactive 2,2′:5′,2″-terthiophene monomers including oxyethylene chains for solid-state flexible energy storage applications

Yigit D., Güllü M.

Electrochimica Acta, vol.389, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 389
  • Publication Date: 2021
  • Doi Number: 10.1016/j.electacta.2021.138662
  • Journal Name: Electrochimica Acta
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Communication Abstracts, INSPEC, Metadex, Civil Engineering Abstracts
  • Keywords: 2,2 ':5 ',2 ''-terthiophene-based electroactive monomers, Poly(2,2 ':5 ',2 ''-terthiophene)s, Redox-active electrodes, Symmetric solid-state supercapacitors, Flexible supercapacitor devices, HIGH-PERFORMANCE, ELECTRODE MATERIALS, ALKYL-CHAIN, SUPERCAPACITIVE PERFORMANCES, ELECTROCHEMICAL PROPERTIES, REDOX SUPERCAPACITORS, CONDUCTING POLYMERS, CYCLING STABILITY, CARBON NANOTUBES, POLYPYRROLE
  • Lokman Hekim University Affiliated: Yes


© 2021Here, we present the synthesis of novel poly(2,2′:5′,2″-terthiophene) derivatives containing oxyethylene pendant groups for the fabrication of high performance flexible redox-active electrode materials. The poly(3′,4′-bis(2-methoxyethoxy)-2,2′:5′,2″-terthiophene) (PSEDEN1), poly(3′,4′-bis(2-(2-methoxyethoxy)ethoxy)-2,2′:5′,2″-terthiophene) (PSEDEN2) and poly(3′,4′-bis(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)-2,2′:5′,2″-terthiophene) (PSEDEN3) have been electrochemically polymerized on flexible stainless steel substrates without any binder and directly employed as redox-active materials. The effect of pendant group chain length on morphological characteristics of conducting polymer films have been systematically evaluated and correlated to the charge storage properties of redox-active electrode materials. Capacitive performance tests reveal that PSEDEN1, PSEDEN2 and PSEDEN3 could reach up to specific capacitances of 135 F g−1, 212.8 F g−1 and 403.3 F g−1, respectively, at constant current density of 2.5 mA cm−2 in the potential range of 0.4–1.8 V with good rate capability performances. In addition, symmetrical flexible solid-state supercapacitor devices based on polymer gel electrolyte have also been assembled using PSEDEN1, PSEDEN2 and PSEDEN3 coated flexible stainless steel substrates and tested by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy techniques in detail. Fabricated devices (Cell 1, Cell 2 and Cell 3) have delivered maximum specific capacitances of Cspec= 29.3 F g−1, 92.1 F g−1 and 162.4 F g−1, energy densities of SE= 6.35 W h kg−1, 22.9 W h kg−1 and 41.1 W h kg−1 and power densities of SP= 929 W kg−1, 937.7 W kg−1 and 986.4 W kg−1 at a current density of 2.5 mA cm−2 in two-electrode cell configuration. Furthermore, flexible supercapacitor devices have achieved high cycle life performances with good capacitance retention values of 80.2%, 84.7% and 91.4% over 10 000 consecutive galvanic charge/discharge cycles at 2.5 mA cm−2 constant current density from 0.4 to 1.8 V. Similarly, excellent mechanical stabilities have also been observed with 3.4%, 4.66% and 1.97% capacitance losses under various bending conditions from 0° to 170° for all flexible supercapacitor devices. These results confirm that PSEDEN1, PSEDEN2 and PSEDEN3 redox-active materials with gratifying capacitive performances and excellent flexibilities have a great potential for utilization in innovative flexible or wearable energy storage solutions. Keywords