Title:Activation Energy Rechargeable Prussian Yellow Nano Film Electrode
using Hydrated Ions
Volume: 15
Issue: 4
Author(s): Abeer Baioun*Hassan Kellawi
Affiliation:
- Electrochemical Laboratory, Department of Chemistry, Faculty of Science, Damascus University, Damascus, Syria
Keywords:
Electrochromic film, redox charge/discharge coloration, prussian yellow, prussian blue, prussian white, cyclic voltammetry, contrast ratio, coloration efficiency.
Abstract:
Aim: Interfacial charge transfer is a fundamental issue in both the science and technology
of the batteries. In this work, the activation energy for the interfacial charge transfer, Ea, though PY
thin film was estimated by measurement measurements of electrochemical impedance spectroscopy
(EIS) for both monovalent and multivalent hydration cations: Li+, Na+, K+, Ca+2 and Mg+2 in aqueous
electrolytes.
Background: Rechargeable batteries have become quintessential energy conversion devices that are
widely used in portable electronic devices and hybrid electric vehicles. PB and its analogues have
open channels that allow rapid insertion/extraction of different cations and that lead to a long cycle
of its in such as batteries (Na+, Li+ and K+).
Objective: preparation of Prussian yellow Nanofilm on ITO glass by a simple chemical facial method
and study of its charge/discharge processes of intercalation compounds in rechargeable features.
Methods: The electrochemical measurements of potentiostat/galvanostat cyclic voltammograms and
EIS were carried out in three-electrode cells, with Ag/AgCl as a reference electrode. Pt. and ITO|PY
as working and counter electrodes respectively. The electrolytes were solutions of 0.1 M+z cation in
water where M+z was one of the following cations: Li+, Na+, K+, Ca+2 or Mg+2.
Results: The effect of hydration on the activation energy for the PY thin film was studied by the EIS
at different temperatures. The ions K+ have an activation energy interfacial, which is lower than that
of Na+ and Li+. So the coulombic repulsion at the interface is largely suppressed by the screening effect
of ions hydration, explaining the small values of Ea with aqueous electrolyte. Furthermore, the
hydration helped the Ca+2 and Mg+2 intercalation in PBA but with large values of Ea that were due to
coulombic repulsion at the interface.
Conclusion: Prussian blue can be considered among the most promising cathode materials for energy
storage batteries because of their rigid open framework with large interstitial sites that can pertain
to mono and bivalent cation mobility and accommodate volume variation during ions insertion/
extraction.
