| Autor: |
Hey, Dominic, Jethwa, Rajesh B., Farag, Nadia L., Rinkel, Bernardine L. D., Zhao, Evan Wenbo, Grey, Clare P. |
| Předmět: |
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| Zdroj: |
Nature Communications; 8/25/2023, Vol. 14 Issue 1, p1-10, 10p |
| Abstrakt: |
While aqueous organic redox flow batteries (RFBs) represent potential solutions to large-scale grid storage, their electrolytes suffer from short lifetimes due to rapid degradation. We show how an understanding of these degradation processes can be used to dramatically improve performance, as illustrated here via a detailed study of the redox-active biomolecule, flavin mononucleotide (FMN), a molecule readily derived from vitamin B2. Via in-situ nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) we identify FMN hydrolysis products and show that these give rise to the additional plateau seen during charging of an FMN-cyanoferrate battery. The redox reactions of the hydrolysis product are not reversible, but we demonstrate that capacity is still retained even after substantial hydrolysis, albeit with reduced voltaic efficiency, FMN acting as a redox mediator. Critically, we demonstrate that degradation is mitigated and battery efficiency is substantially improved by lowering the pH to 11. Furthermore, the addition of cheap electrolyte salts to tune the pH results in a dramatic increase in solubility (above 1 M), this systematic improvement of the flavin-based system bringing RFBs one step closer to commercial viability. Aqueous organic redox-flow batteries are known to suffer capacity loss via degradation of the redox-active species. Here, the authors use in situ methods to study the electrolyte flavin mononucleotide, identifying a redox mediator mechanism that mitigates capacity loss and a route to prevent its degradation. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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