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

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• 作者：Christo S. Sevov ; Rachel E. M. Brooner ; Etienne Ch茅nard ; Rajeev S. Assary ; Jeffrey S. Moore ; Joaqu铆n Rodr铆guez-L贸pez ; Melanie S. Sanford
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：November 18, 2015
• 年：2015
• 卷：137
• 期：45
• 页码：14465-14472
• 全文大小：593K
• ISSN：1520-5126

文摘

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路e^{鈭?/sup>) 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, is prepared in a single synthetic step, has a low equivalent weight of 111 g/(mol路e鈭?/sup>), and undergoes two reversible 1e鈥?/i> reductions in the presence of LiBF₄ to form reduced products that are stable over days in solution.}