Thermodynamic strategies to increase solubility for higher energy density in organic redox flow batteries
Year: 2025
Type: article
Abstract: Improving the solubility of redox-active organic molecules (ROMs) in electrolyte solutions is vital for boosting the energy density of redox flow batteries and avoiding precipitation issues. This study explores six thermodynamic strategies to enhance ROM solubility by lowering melting points or activity coefficients. Minor structural changes—such as tuning alkyl side chains, repositioning functional groups, or altering ROM ligands—introduce molecular asymmetry, consistently increasing solubility and energy density in various electrolyte solutions. Furthermore, tailored co-solvents or salting-in agents strengthen solute–solvent interactions, reducing activity coefficients. COSMO-RS proves effective for qualitatively assessing these modifications. These strategies collectively offer a structured approach to designing molecules and selecting solvent additives, optimizing ROM solubility and elevating battery performance.
Source: Journal of Energy Storage
Institutions: University of Aveiro, Universidad de Burgos
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,560
Funders: European Commission, Ministerio de Ciencia e Innovación, Ministério da Ciência, Tecnologia e Ensino Superior, Fundação para a Ciência e a Tecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Agencia Estatal de Investigación, HORIZON EUROPE European Innovation Council
OpenAlex ID: W4410633232