Highly Soluble 1,4-Diaminoanthraquinone Derivative for Nonaqueous Symmetric Redox Flow Batteries
Highly Soluble 1,4-Diaminoanthraquinone Derivative for Nonaqueous Symmetric Redox Flow Batteries
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DOI：
10.1021/acssuschemeng.9b07244
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发表时间：
2020-03-09
影响因子：
8.4
通讯作者：
Binnemans, Koen
中科院分区：
文献类型：
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作者：
Geysens, Pieter;Li, Yun;Binnemans, Koen
基于氧化还原活性有机分子的非水氧化还原液流电池（RFBs）被认为是一种有前途的大规模电网储能技术。1，4-二氨基蒽醌（DAAQ）作为活性物质特别令人感兴趣，因为它们可以具有多达五种不同的电化学可接近的氧化态，但由于它们在常用极性有机溶剂中的低溶解度，它们的实际可用性受到限制。我们提出了一种DAAQ衍生物，1，4-双（（2-（2-（2-甲氧基乙氧基）乙氧基）乙基）氨基）蒽烯-9，10-二酮（Me-TEG-DAAQ），它可以从廉价的前体合成，并克服了溶解度低的缺点。该衍生物具有低熔点（25 ℃），在纯状态下浓度超过2.2 mol L-1，并且可以以任何比例与极性有机溶剂如乙腈（MeCN）和1，2-二甲氧基乙烷混溶。循环伏安实验表明，两个阳极和两个阴极的单电子氧化还原转变是电化学可及的和高度可逆的，与两个内部氧化还原对之间的1.8 V和两个外部氧化还原对之间的2.7 V的间隔。在简单对称电化学电池中对Me-TEG-DAAQ的稀溶液进行概念验证恒电流循环实验。当仅考虑两个内部氧化还原对时，电化学电池可以实现接近理论值（2.68 A h L-1）的比容量，仅具有有限的容量衰减（即，49 W h L-1），并且在基于单一活性物质的电化学电池中的有限容量衰减在RFB文献中是前所未有的。
Nonaqueous redox flow batteries (RFBs) based on redox-active organic molecules are regarded as a promising technology for large-scale grid energy storage. 1,4-Diaminoanthraquinones (DAAQs) are particularly interesting as active species because they can have up to five different electrochemically accessible oxidation states, but their practical usability is limited because of their low solubility in commonly used polar organic solvents. We present a DAAQ derivative, 1,4-bis((2-(2-(2-methoxyethoxy) ethoxy) ethyl) amino) anthra cene-9,10-dione (Me-TEG-DAAQ), which can be synthesized from inexpensive precursors and overcomes this disadvantage of low solubility. This derivative has a low melting point (25 degrees C), a concentration exceeding 2.2 mol L-1 in the pure state, and is miscible in any ratio with polar organic solvents such as acetonitrile (MeCN) and 1,2-dimethoxyethane. Cyclic voltammetry experiments show that two anodic and two cathodic one-electron redox transitions are electrochemically accessible and highly reversible, with an interval of 1.8 V between the two inner redox couples and 2.7 V between the two outer redox couples. Proof-of-concept galvanostatic cycling experiments were conducted on dilute solutions of Me-TEG-DAAQ in a simple symmetric electrochemical cell. When only the two inner redox couples are considered, the electrochemical cell can achieve specific capacities close to the theoretical value (2.68 A h L-1) with only limited capacity fading (i.e., 49 W h L-1), and limited capacity fading in an electrochemical cell based on one single active species is unprecedented in the RFB literature.