Redox flow batteries based on quinonebearing aqueous electrolytes have emerged as promising systems for energy storage from intermittent renewable sources. The lifetime of these batteries is limited by quinone stability. Here, we confirm that 2,6-dihydroxyanthrahydroquinone tends to form an anthrone intermediate that is vulnerable to subsequent irreversible dimerization. We demonstrate quantitatively that this decomposition pathway is responsible for the loss of battery capacity. Computational studies indicate that the driving force for anthrone formation is greater for anthraquinones with lower reduction potentials. We show that the decomposition can be substantially mitigated. We demonstrate that conditions minimizing anthrone formation and avoiding anthrone dimerization slow the capacity loss rate by over an order of magnitude. We anticipate that this mitigation strategy readily extends to other anthraquinone-based flow batteries and is thus an important step toward realizing renewable electricity storage through long-lived organic flow batteries.
|Number of pages||6|
|Journal||Journal of the American Chemical Society|
|State||Published - 2020|
Bibliographical noteFunding Information:
This research was supported by U.S. DOE award DE-AC05-76RL01830 through PNNL subcontract 428977, by U.S. DOE ARPA-E award DE-AR-0000767, by Innovation Fund Denmark via the Grand Solutions project “ORBATS” file no. 7046-00018B, by the Massachusetts Clean Energy Technology Center, and by the Harvard School of Engineering and Applied Sciences. D.A.P. acknowledges funding support from the NSF Graduate Research Fellowship Program, no. DGE1144152 and DGE1745303. A.A.-G. acknowledges support from the Canada 150 Research Chair Program. We thank Prof. Cyrille Costentin, Prof. Luke M. Davis, Dr. Eugene S. Beh, Prof. Sergio Granados-Focil, and Prof. Alison E. Wendlandt for helpful discussions and Eric Fell for experimental support.
© 2019 American Chemical Society.
ASJC Scopus subject areas
- Chemistry (all)
- Colloid and Surface Chemistry