Evolutionary Design of Low Molecular Weight Organic Anolyte Materials for Applications in Nonaqueous Redox Flow Batteries
摘要:
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, is 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.
Visible light photoredox alkylazidation of alkenes with sodium azide and heteroarenium salts: entry to azido-containing 1,4-dihydropyridines
作者:Yuan Yang、Chong-Hui Xu、Zhi-Qiang Xiong、Jin-Heng Li
DOI:10.1039/d0cc03235b
日期:——
A three-component alkene alkylazidation using sodium azide as the azido resource and heteroarenium salts as functionalized alkyl reagents for producing highly valuable 2-azido-1-(1,4-dihydropyridin-4-yl)-ethanes is described. This reaction allows the incorporation of both an azido group and a 1,4-dihydropyridin-4-yl group across CC bonds to construct two new bonds in a single reaction step, and represents
Electron-transfer reactions of rhenium carbonyl radicals with N-methylpyridinium cations: application of Marcus-type relationships
作者:Michael R. Burke、Theodore L. Brown
DOI:10.1021/ja00196a027
日期:1989.7
radicals, Re(CO)sub 4}L* (L = PMesub 3} or P(O-i-Pr)sub 3}), generated via flashphotolysis at 22degree}C of acetonitrile solutions of the corresponding dinuclear compounds, Resub 2}(CO)sub 8}Lsub 2}, are observed to undergo electron transfer to substituted N-methylpyridinium cations. Reaction rates were measured by observing the disappearance of the transient absorption due to Re(CO)sub 4}L* or