Na-ion conducting gel polymer membrane for flexible supercapacitor application

Jingwei Wang, Guohua Chen, Shenhua Song

Research output: Journal article publicationJournal articleAcademic researchpeer-review

13 Citations (Scopus)

Abstract

A sodium-ion conducting poly(vinyl alcohol)-based gel polymer electrolyte membrane is developed by plasticizing with an ionic liquid, for the fabrication of electric double-layer capacitors. Sodium triflate is selected as the sodium salt. 1-Ethyl-3 methylimidazoliumtrifluoromethanesulfonate is employed as the plasticizer. The properties of the electrolyte membranes are analyzed in terms of their crystallinity, morphology, thermal stability, electrochemical stability window, ionic transference number, and ionic conductivity. The composition with poly(vinyl alcohol) - 30% sodium triflate + 10% 1-ethyl-3 methylimidazoliumtrifluoromethanesulfonate shows the optimal performances such as good thermal stability up to 150 °C and wide electrochemical stability window of 4.70 V. It is thus employed in the fabrication of electric double-layer capacitors, serving as both ion-conducting electrolyte and separator. The capacitor shows almost 100% coulombic efficiency and stable charge-discharge cyclic property with almost 100% capacity retention after 1000 cycles, when charging up to 1.6 V and 2.0 V with a specific capacitance of 103.7 and 127.8 F g−1, respectively. It compares well with that made of a liquid electrolyte. This excellent performance is attributed to the sodium triflate with large-sized anions and thus high ionic conductivity (3.8 × 10−3 S cm−1) of the electrolyte membrane.

Original languageEnglish
Article number135322
JournalElectrochimica Acta
Volume330
DOIs
Publication statusPublished - 10 Jan 2020

Keywords

  • Electric double-layer capacitors
  • Gel polymer electrolytes
  • Ionic conductivity
  • Ionic liquid plasticizer
  • Sodium ion supercapacitor

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Electrochemistry

Cite this