Capacitive performance of electrochemically deposited Co/Ni oxides/hydroxides on polythiophene-coated carbon-cloth


Atun G., Sahin F., TÜRKER ACAR E., ORTABOY SEZER S.

JOURNAL OF POLYMER ENGINEERING, vol.42, no.2, pp.151-162, 2022 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 42 Issue: 2
  • Publication Date: 2022
  • Doi Number: 10.1515/polyeng-2021-0049
  • Journal Name: JOURNAL OF POLYMER ENGINEERING
  • Journal Indexes: Science Citation Index Expanded, Scopus, Applied Science & Technology Source, Compendex, INSPEC
  • Page Numbers: pp.151-162
  • Keywords: carbon-cloth, cobalt hydroxide, nickel hydroxide, polythiophene, supercapacitor, LAYERED DOUBLE HYDROXIDES, ELECTRODE MATERIALS, SUPERCAPACITIVE PROPERTIES, MICROWAVE SYNTHESIS, OXIDE NANOWIRES, NICKEL FOAM, ENERGY, NANOSHEETS, NANOTUBES, NANOCOMPOSITES

Abstract

Cobalt, nickel, and their mixed hydroxides were electrochemically deposited on polythiophene-coated carbon-cloth substrate to develop new pseudo-capacitive electrodes for energy storage devices. Thiophene was electro-polymerized on carbon-cloth by the potentiodynamic method in acetonitrile containing 1-butyl-2,3-dimethylimidazolium hexafluorophosphate ionic-liquid as supporting electrolyte. The scanning-electron-microscopy images imply that flower-like Co(OH)(2) microstructures deposited on bamboo-like polythiophene coatings on carbon-fibers but they are covered by net curtain like thin Ni(OH)(2) layer. The Co-Ni layered-double-hydroxide deposited from their equimolar sulfate solutions is composed of large aggregates. The electron-dispersive-spectrum exhibits that Co/Ni ratio equals unity in the layered-double-hydroxide. The capacitances of Co, Ni, and Co-Ni hydroxide-coated PTh electrodes are 100, 569, and 221 F/g at 5 mA/cm(2) in 1 M KOH solution, respectively. Their corresponding oxides obtained by calcination at 450 degrees C in de-aerated medium possess higher capacitance up to 911, 643, and 696 F/g at 2 A/cm(2). The shape of cyclic-voltammetry and galvanostatic-charge-discharge curves, as well as the Nyquist plots derived from electrochemical-impedance-spectroscopy measurements, reveal that hydroxide coatings on the polythiophene-coated carbon-cloth are more promising electrode materials for supercapacitor applications. The mixed hydroxide-coated electrode shows good cyclic stability of 100% after 400 cycles at 5 mA/cm(2).