Abstract
This article discusses the conversion of electrodeposited iodine to polyiodides within the nanopores of carbon electrodes that affect the performance of iodide electrolyte-based electrochemical cells. Here, carbon electrodes have been polarized in aqueous sodium iodide electrolyte to store charge in the form of solid iodine via highly reversible reaction (2I −⇌I 2+2e −). The stored iodine within the pores interacts with free iodide ions present in the bulk electrolyte via comproportionation reactions leading to polyiodide (I 3 − and I 5 −) formations. By tuning the mass asymmetry of carbon electrodes in hybrid cells and using the in-situ Raman spectroscopy on positive battery electrode, we show the influence of iodine/polyiodides equilibrium shifts on the self-discharge and voltage rebounds during open circuit conditions. This study provides insights into the charging mechanisms of carbon electrodes for iodine-based hybrid supercapacitors and battery systems.
Original language | English |
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Pages (from-to) | 3155-3160 |
Number of pages | 6 |
Journal | ChemElectroChem |
Volume | 8 |
Issue number | 16 |
DOIs | |
Publication status | Published - 13 Aug 2021 |
Keywords
- hybrid energy storage
- iodide redox-active electrolyte
- iodine electrodeposition
- nanoporous carbon
- supercapacitor
ASJC Scopus subject areas
- General Materials Science
- Catalysis
- Electrochemistry
Fields of Expertise
- Advanced Materials Science
Treatment code (Nähere Zuordnung)
- Basic - Fundamental (Grundlagenforschung)