NaHSO3 as a Key Component in Developing Enhanced Performance Electrolytes for All-Iron Redox Flow Batteries
Redox flow batteries (RFBs) are attractive electrochemical systems for large-scale energy storage. Despite the most developed ones being those based on vanadium, the search for new chemistries is essential to overcome several problems associated with this metal identified as a critical raw material....
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/398596 |
| Acceso en línea: | http://hdl.handle.net/10261/398596 https://api.elsevier.com/content/abstract/scopus_id/85215303937 |
| Access Level: | acceso abierto |
| Palabra clave: | iron-based aqueous electrolyte all-iron redox flow battery electrochemical performance http://metadata.un.org/sdg/9 Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation |
| Sumario: | Redox flow batteries (RFBs) are attractive electrochemical systems for large-scale energy storage. Despite the most developed ones being those based on vanadium, the search for new chemistries is essential to overcome several problems associated with this metal identified as a critical raw material. All-iron redox flow battery (A-IRFB) is an interesting device due to iron abundance and worldwide distribution. However, the poor performance of its negative half-cell, due to the sluggish plating/stripping processes related to the Fe<sup>2+</sup>/Fe<sup>0</sup> redox pair, negatively impacts its energy efficiency and long-term performance. Here, it is demonstrated that the addition of a low concentration of NaHSO<inf>3</inf> (10 mM), as a novel additive, to an electrolyte formulation based on 0.5 M FeCl<inf>2</inf>, 3 M NaCl, and 10 mM citric acid (H<inf>3</inf>Cit) remarkably improves the electrochemical behavior of the negative half-cell. The enhanced performance can be explained as the additive guarantees a low oxygen solution content (reductant agent), promotes the plating/stripping reactions (improving the kinetics of the Fe<sup>0</sup> deposit through the formation of a FeHSO<inf>3</inf><sup>+</sup> complex), and diminishes the contribution of the competitive hydrogen evolution reaction. The use of this key additive opens up a promising scenario for the development of A-IRFBs with significantly enhanced electrochemical performance, thus boosting their potential commercial development. |
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