A symmetric organic-based nonaqueous redox flow battery and its state of charge diagnostics by FTIR
Redox flow batteries have shown outstanding promise for grid-scale energy storage to promote utilization of renewable energy and improve grid stability. Nonaqueous battery systems can potentially achieve high energy density because of their broad voltage window. In this paper, we report a new organic redox-active material for use in a nonaqueous redox flow battery, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) that has high solubility (>2.6 M) in organic solvents. PTIO exhibits electrochemically reversible disproportionation reactions and thus can serve as both anolyte and catholyte redox materials in a symmetric flow cell. The PTIO flow battery has a moderate cell voltage of ~1.7 V and shows good cyclability under both cyclic voltammetry and flow cell conditions. Moreover, we demonstrate that FTIR can offer accurate estimation of the PTIO concentration in electrolytes and determine the state of charge of the PTIO flow cell, which suggests FTIR potentially as a powerful online battery status sensor. In conclusion, this study is expected to inspire more insights in this under-addressed area of state of charge analysis aiming at operational safety and reliability of flow batteries.
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- Joint Center for Energy Storage Research (JCESR) (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Joint Center for Energy Storage Research (JCESR) (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Chemical Engineering
- Joint Center for Energy Storage Research (JCESR) (United States); Univ. of Michigan, Ann Arbor, MI (United States)
- Joint Center for Energy Storage Research (JCESR) (United States); Univ. of Illinois Urbana-Champaign, Urbana, IL (United States)
- Joint Center for Energy Storage Research (JCESR) (United States); Argonne National Lab. (ANL), Lemont, IL (United States)
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Joint Center for Energy Storage Research (JCESR) (United States); United Technologies Research Center, East Hartford, CT (United States)
- Joint Center for Energy Storage Research (JCESR) (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
- Publication Date:
- Report Number(s):
- PNNL-SA-115896
Journal ID: ISSN 2050-7488; JMCAET; 48374; KC0208010
- Grant/Contract Number:
- AC05-76RL01830
- Type:
- Accepted Manuscript
- Journal Name:
- Journal of Materials Chemistry. A
- Additional Journal Information:
- Journal Volume: 4; Journal Issue: 15; Journal ID: ISSN 2050-7488
- Publisher:
- Royal Society of Chemistry
- Research Org:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Org:
- USDOE
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Environmental Molecular Sciences Laboratory
- OSTI Identifier:
- 1254564
- Free Publicly Accessible Full Text
-
Accepted Manuscript (DOE)
- Publisher's Version of Record
- https://doi.org/10.1039/c6ta01177b