108228-37-1Relevant articles and documents
Designer Two-Electron Storage Viologen Anolyte Materials for Neutral Aqueous Organic Redox Flow Batteries
DeBruler, Camden,Hu, Bo,Moss, Jared,Liu, Xuan,Luo, Jian,Sun, Yujie,Liu, T. Leo
, p. 961 - 978 (2017)
Aqueous organic redox flow batteries (AORFBs) are highly attractive for large-scale energy storage because redox-active organic molecules are synthetically tunable, sustainable, and potentially low cost. Here, we show that rational molecular engineering yielded a series of two-electron storage viologen molecules as anolyte materials for AORFBs. In neutral NaCl solutions, these viologen anolytes have a theoretical capacity of up to 96.5 Ah/L in H2O and exhibit a reduction potential as low as ?0.78 V versus normal hydrogen electrode. The neutral aqueous flow batteries with two two-electron storage viologen molecules delivered a cell voltage of up to 1.38 V and outstanding battery performance, including a power density of up to 130 mW/cm2, capacity retention of up to 99.99% per cycle, and energy efficiency of up to 65% at 60 mA/cm2. Density functional theory calculations revealed that the 1e? and 2e? reduced redox states of these molecules were stabilized by the high charge delocalization of their frontier SOMO or HOMO. Renewable energy (e.g., solar and wind) can make a significant contribution to meeting the increasing global energy demands. However, its successful penetration into the existing electrical grids requires effective energy-storage solutions to overcome its intermittence. Redox flow batteries (RFBs) are a suitable option for large-scale energy-storage applications (up to MW/MWh). There is an urgent call to develop low-cost and benign RFB technologies to meet the burgeoning energy-storage demands. A new generation of aqueous organic RFBs utilizing sustainable and tunable redox-active organic molecules has emerged as a game changer for electrochemical energy storage. In the present study, we report a class of rationally designed highly reductive and high-charge capacity redox-active viologen molecules as a class of two-electron storage anolyte materials that promise aqueous organic RFBs with high voltage, high power density, and high energy density. Liu and co-workers reported a series of rationally designed two-electron storage viologen molecules as anolytes for high-voltage and high-power pH-neutral aqueous organic redox flow batteries. The synthetic and computational chemistry presented has opened a new avenue for designing energy-dense redox-active organic molecules for building neutral AORFBs with high power density and high energy density, and it promises economical, benign, and widespread uses of redox flow batteries in large-scale energy storage.
VIOLOGENS WITH CHARGED GROUPS: NEW REDOX CARRIERS IN REACTIONS OF PHOTOCATALYTIC SEPARATION OF HYDROGEN FROM WATER IN HOMOGENEOUS AND VESICULAR SYSTEMS
Maier, V. E.,Kitaigorodskii, A. N.,Khannanov, N. K.,Shafirovich, V. Ya.
, p. 2281 - 2286 (1987)
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AQUEOUS REDOX FLOW BATTERY ELECTROLYTES WITH HIGH CHEMICAL AND ELECTROCHEMICAL STABILITY, HIGH WATER SOLUBILITY, LOW MEMBRANE PERMEABILITY
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Paragraph 0070; 0074, (2020/12/08)
The invention features redox flow batteries and compound useful therein as negolytes or posolytes. The batteries and compounds are advantageous in terms of being useable in water solutions at neutral pH and have extremely high capacity retention. Suitable negolytes are diquaternized bipyridines, suitable posolytes are water-soluble ferrocene derivatives.
