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Abstract Redox‐active anthraquinone molecules represent promising anolyte materials in aqueous organic redox flow batteries (AORFBs). However, the chemical stability issue and corrosion nature of anthraquinone‐based anolytes in reported acidic and alkaline AORFBs constitute a roadblock for their practical applications in energy storage. A feasible strategy to overcome these issues is migrating to pH‐neutral conditions and employing soluble AQDS salts. Herein, we report the 9,10‐anthraquinone‐2,7‐disulfonic diammonium saltAQDS(NH4)2, as an anolyte material for pH‐neutral AORFBs with solubility of 1.9 min water, which is more than 3 times that of the corresponding sodium salt. Paired with an NH4I catholyte, the resulting pH‐neutral AORFB with an energy density of 12.5 Wh L−1displayed outstanding cycling stability over 300 cycles. Even at the pH‐neutral condition, theAQDS(NH4)2 /NH4I AORFB delivered an impressive energy efficiency of 70.6 % at 60 mA cm−2and a high power density of 91.5 mW cm−2at 100 % SOC. The present AQDS(NH4)2flow battery chemistry opens a new avenue to apply anthraquinone molecules in developing low‐cost and benign pH‐neutral flow batteries for scalable energy storage.
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In situ electrosynthesis of anthraquinone electrolytes in aqueous flow batteries
We demonstrate the electrochemical oxidation of an anthracene derivative to a redox-active anthraquinone at room temperature in a flow cell without the use of hazardous oxidants or noble metal catalysts. The anthraquinone, generated in situ , was used as the active species in a flow battery electrolyte without further modification or purification. This potentially scalable, safe, green, and economical electrosynthetic method is also applied to another anthracene-based derivative and may be extended to other redox-active aromatics.
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- Award ID(s):
- 1914543
- PAR ID:
- 10244149
- Date Published:
- Journal Name:
- Green Chemistry
- Volume:
- 22
- Issue:
- 18
- ISSN:
- 1463-9262
- Page Range / eLocation ID:
- 6084 to 6092
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D0GC02236E
