Title: Evolutionary Design of Low Molecular Weight Organic Anolyte Materials for Applications in Nonaqueous Redox Flow Batteries

Abstract

The integration of renewable energy sources into the electric grid requires low-cost energy storage systems that mediate the variable and intermittent flux of energy associated with most renewables. Nonaqueous redox-flow batteries have emerged as a promising technology for grid-scale energy storage applications. Because the cost of the system scales with mass, the electroactive materials must have a low equivalent weight (ideally 150 g/(mol·e^–) or less), and must function with low molecular weight supporting electrolytes such as LiBF₄. However, soluble anolyte materials that undergo reversible redox processes in the presence of Li-ion supports are rare. We report the evolutionary design of a series of pyridine-based anolyte materials that exhibit up to two reversible redox couples at low potentials in the presence of Li-ion supporting electrolytes. A combination of cyclic voltammetry of anolyte candidates and independent synthesis of their corresponding charged-states was performed to rapidly screen for the most promising candidates. Results of this workflow provided evidence for possible decomposition pathways of first-generation materials and guided synthetic modifications to improve the stability of anolyte materials under the targeted conditions. This iterative process led to the identification of a promising anolyte material, N-methyl 4-acetylpyridinium tetrafluoroborate. This compound is soluble in nonaqueous solvents, ismore » prepared in a single synthetic step, has a low equivalent weight of 111 g/(mol·e^–), and undergoes two reversible 1e^– reductions in the presence of LiBF₄ to form reduced products that are stable over days in solution.« less

Authors:

Sevov, Christo S. ^[1]; Brooner, Rachel E. M. ^[1]; Chénard, Etienne ^[2]; Assary, Rajeev S. ^[3]; Moore, Jeffrey S. ^[4]; Rodríguez-López, Joaquín ^[2]; Sanford, Melanie S. ^[1]

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+ Show Author Affiliations

1. Joint Center for Energy Storage Research, Argonne, Illinois 60439, United States, Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
2. Joint Center for Energy Storage Research, Argonne, Illinois 60439, United States, Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
3. Joint Center for Energy Storage Research, Argonne, Illinois 60439, United States, Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
4. Joint Center for Energy Storage Research, Argonne, Illinois 60439, United States, Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States

Publication Date:

Fri Oct 30 00:00:00 EDT 2015

Research Org.:

Argonne National Laboratory (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES). Joint Center for Energy Storage Research (JCESR)

OSTI Identifier:

1225406

Alternate Identifier(s):

OSTI ID: 1352862

Grant/Contract Number:  

AC02-06CH11357

Resource Type:

Journal Article: Published Article

Journal Name:

Journal of the American Chemical Society

Additional Journal Information:

Journal Name: Journal of the American Chemical Society Journal Volume: 137 Journal Issue: 45; Journal ID: ISSN 0002-7863

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

25 ENERGY STORAGE; Salts; Redox reactions; Organic reactions; Electrolytes; Materials