Application of the dianion croconate violet for symmetric organic non-aqueous redox flow battery electrolytes
Application of the dianion croconate violet for symmetric organic non-aqueous redox flow battery electrolytes
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DOI：
10.1016/j.jpowsour.2019.227037
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发表时间：
2019-11-15
影响因子：
9.2
通讯作者：
Toghill, Kathryn E.
中科院分区：
文献类型：
--
作者：
Armstrong, Craig G.;Hogue, Ross W.;Toghill, Kathryn E.
氧化还原活性有机分子(ROMs)由于具有高可持续性和低成本等优点，在氧化还原液流电池(RFB)储能方面具有广阔的应用前景。本文将假氧碳衍生物巴豆紫(Croc(2-))作为一种新型的对称只读存储器应用于乙腈电解液中，将Croc(2-)同时用作电池正极和负极，电池电位为1.82V，溶解度接近或等于1M。通过伏安法和电池循环技术对双阴离子Croc(2-)进行了表征，证明了Croc(2-)具有高数量的氧化态，从而突出了低分子量只读存储器的高固有容量。研究了Croc(2-)及其带电自由基态的稳定性，以评估对称设计的可行性，并确定了Croc(中心点3-)氧化态的不希望看到的自由基歧化机理，以解释容量保持性差的原因。将Croc(2-)与2，1，3-苯并噻二唑或四氰基喹甲烷负极进行不对称电池实验，电池性能得到改善，表明Croc(2-)是一种很有前途的阴离子只读存储器正极。
Redox active organic molecules (ROMs) are promising candidates for redox flow battery (RFB) energy storage due to their high sustainability and low cost. Herein, the pseudooxocarbon derivative croconate violet (Croc(2-)) is applied as a novel symmetric ROM in acetonitrile electrolyte, whereby Croc(2-) is used as both the battery posolyte and negolyte, with a 1.82 V cell potential and similar or equal to 1 M solubility. Characterisation of the dianion Croc(2-) is given by way of voltammetry and battery cycling techniques to demonstrate the high number of oxidation states accessible by Croc(2-), thus highlighting a high intrinsic capacity for a low molecular weight ROM. The stability of Croc(2-) and its charged radical states is investigated to assess the viability of the symmetric design, and an undesirable radical disproportionation mechanism of the Croc(center dot 3-) oxidation state is identified to account for poor capacity retention. Asymmetric battery experiments of a Croc(2-) posolyte with 2,1,3-benzothiadiazole or tetracyanoquinodimethane negolytes gave improved battery performance, indicating that Croc(2-) is a promising anionic ROM posolyte.