Revisiting the cycling stability of ferrocyanide in alkaline media for redox flow batteries

In the quest for searching for new redox-flow battery chemistries, cycling stability must be carefully evaluated since it is one of the most important parameters of new active species. However, it is challenging to elucidate the intrinsic stability during operation of a redox flow battery. The symme...

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Detalles Bibliográficos
Autores: Páez, Teresa, Martínez Cuezva, Alberto, Palma, Jesús, Ventosa Arbaizar, Edgar
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2020
País:España
Institución:Universidad de Burgos (UBU)
Repositorio:Repositorio Institucional de la Universidad de Burgos (RIUBU)
OAI Identifier:oai:riubu.ubu.es:10259/5824
Acceso en línea:http://hdl.handle.net/10259/5824
Access Level:acceso abierto
Palabra clave:Redox flow batteries
Electrochemistry
Stability
Ferrocyanide
Alkaline media
Química analítica
Chemistry, Analytic
Descripción
Sumario:In the quest for searching for new redox-flow battery chemistries, cycling stability must be carefully evaluated since it is one of the most important parameters of new active species. However, it is challenging to elucidate the intrinsic stability during operation of a redox flow battery. The symmetrical flow battery cell is a powerful tool that helps to unambiguously determine the cycling stability. Herein, trustworthiness of this technique is critically re-evaluated. Potassium ferrocyanide in alkaline media is used as a case study since i) it is the best performing species for the catholyte of alkaline flow batteries in terms of reversibility, solubility, costs and environmental compatibility and ii) the cycling stability of this species is still under strong debate. Potassium ferrocyanide is found to be stable at pH 14 upon electrochemical cycling when the oxygen evolution reaction is prevented, which should encourage researchers to resume the use of this species. The results also reveal that care should be taken when interpreting results from this powerful technique to avoid misleading conclusions.