“Wine-Dark Sea” in an Organic Flow Battery: Storing Negative Charge in 2,1,3-Benzothiadiazole Radicals Leads to Improved Cyclability

Journal Article · Mon Apr 24 00:00:00 EDT 2017 · ACS Energy Letters

DOI:https://doi.org/10.1021/acsenergylett.7b00261· OSTI ID:1360150

Duan, Wentao ^[1]; Huang, Jinhua ^[2]; Kowalski, Jeffrey A. ^[3]; Shkrob, Ilya A.  ^[2]; Vijayakumar, M. ^[1]; Walter, Eric ^[4]; Pan, Baofei ^[2]; Yang, Zheng ^[1]; Milshtein, Jarrod D. ^[3]; Li, Bin ^[4]; Liao, Chen ^[2]; Zhang, Zhengcheng ^[2]; Wang, Wei  ^[4]; Liu, Jun  ^[1]; Moore, Jeffery S. ^[5]; Brushett, Fikile R.  ^[3]; Zhang, Lu ^[2]; Wei, Xiaoliang  ^[1]

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1. Joint Center for Energy Storage Research, Argonne, IL (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2. Joint Center for Energy Storage Research, Argonne, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
3. Joint Center for Energy Storage Research, Argonne, IL (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
4. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
5. Joint Center for Energy Storage Research, Argonne, IL (United States); Univ. of Illinois Urbana-Champaign, Urbana, IL (United States)

Redox-active organic materials (ROMs) have shown great promise for redox flow battery applications but generally encounter limited cycling efficiency and stability at relevant redox material concentrations in nonaqueous systems. Here we report a new heterocyclic organic anolyte molecule, 2,1,3-benzothiadiazole, that has high solubility, a low redox potential, and fast electrochemical kinetics. Coupling it with a benchmark catholyte ROM, the nonaqueous organic flow battery demonstrated significant improvement in cyclable redox material concentrations and cell efficiencies compared to the state-of-the-art nonaqueous systems. Especially, this system produced exceeding cyclability with relatively stable efficiencies and capacities at high ROM concentrations (>0.5 M), which is ascribed to the highly delocalized charge densities in the radical anions of 2,1,3-benzothiadiazole, leading to good chemical stability. As a result, this material development represents significant progress toward promising next-generation energy storage.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1360150
• Journal Information: ACS Energy Letters, Vol. 2, Issue 5; ISSN 2380-8195
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
flow battery
anolyte
non-aqueous
high concentration
cycling