Designer Two-Electron Storage Viologen Anolyte Materials for Neutral Aqueous Organic Redox Flow Batteries
Designer Two-Electron Storage Viologen Anolyte Materials for Neutral Aqueous Organic Redox Flow Batteries
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DOI：
10.1016/j.chempr.2017.11.001
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发表时间：
2017-12-14
期刊：
影响因子：
23.5
通讯作者：
Liu, T. Leo
中科院分区：
文献类型：
--
作者：
DeBruler, Camden;Hu, Bo;Liu, T. Leo
水性有机氧化还原液流电池(AORFB)因其氧化还原活性有机分子具有可调谐、可持续和潜在的低成本等优点，在大规模储能方面具有极大的吸引力。在这里，我们表明，合理的分子工程生产了一系列的双电子储存紫精分子作为AORFB的阳极液材料。在中性氯化钠溶液中，这些紫精阳极在水中的理论容量高达96.5ah/L，与普通氢电极相比，还原电位低至-0.78V。带有两个双电子储存紫精分子的中性水流电池提供了高达1.38V的电池电压和出色的电池性能，包括高达130 mW/cm(2)的功率密度、高达99.99%的每循环容量保持率以及60 mA/cm(2)时高达65%的能效。密度泛函理论计算表明，这些分子的1E(-)和2E(-)还原的氧化还原态被其前线自组织轨道(SOMO)或HOMO的高电荷离域稳定。
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/cm(2), capacity retention of up to 99.99% per cycle, and energy efficiency of up to 65% at 60 mA/cm(2). 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.