Influence of the physical properties of electrolytes on the behavior of all-vanadium redox flow batteries

Ibáñez, Álvaro (Universidad de Zaragoza) ; Montiel, Manuel ; Tejero, Andrés ; Ortiz de Landazuri, Ignacio ; Lozano, Antonio ; Barroso, Jorge (Universidad de Zaragoza) ; Barreras, Félix

Resumen: Electrolyte flow rate has a large impact on the overall efficiency and energy storage capacity of all‑vanadium redox flow batteries. This work focuses on the detailed determination of density and viscosity of vanadium electrolytes as a function of temperature and state of charge, as well as their influence on the actual electrolyte flow rate. Negative and positive electrolytes present different density and viscosity values and they also evolve differently, the divergence being especially significant in the dynamic viscosity. Mathematical correlations of experimental data are provided, and the influence of these properties on both hydraulic and electrochemical performance of the device is also discussed. An ad hoc experimental facility was manufactured where a 200 W battery was tested to assess the relevance of the different hydraulic conditions on the pressure drop and efficiency. A notable decrease in the total duration of the 5 charge/discharge cycles when the circulating flow rates were progressively reduced was observed. The average efficiency of the battery varied from 73.9% to 67.5% when decreasing the flow rate levels. In addition, a low-cost computational model was developed to estimate the circulating flow rate of each electrolyte and to discriminate the contribution of the specific pressure loss from the different components of the facility for a given operating condition.

Idioma: Inglés

DOI: 10.1016/j.est.2026.120760

Año: 2026

Publicado en: Journal of Energy Storage 152, Parte C (2026), 120760 [14 pp.]
ISSN: 2352-152X

Financiación: info:eu-repo/grantAgreement/ES/DGA/T06-23R
Financiación: info:eu-repo/grantAgreement/ES/DGA/T53-24
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2021-126001OB-C32
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2024-158394OB-C21

Tipo y forma: Article (Published version)

Área (Departamento): Área Mecánica de Fluidos (Dpto. Ciencia Tecnol.Mater.Fl.)