All-PEGylated redox-active metal-free organic molecules in non-aqueous redox flow battery
All-PEGylated redox-active metal-free organic molecules in non-aqueous redox flow battery
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DOI：
10.1039/d0ta02303e
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发表时间：
2020-08-21
影响因子：
11.9
通讯作者：
Jiang, Jianbing 'Jimmy'
中科院分区：
文献类型：
--
作者：
Chai, Jingchao;Lashgari, Amir;Jiang, Jianbing 'Jimmy'
基于非水有机材料的氧化还原液流电池（NAORFBs）具有使用有机溶剂实现高电化学电势的优点。然而，尽管在过去的十年中在这方面取得了很大的进展，但由于缺乏稳定的电活性有机材料和高选择性的隔膜，进一步的发展受到限制。在这里，我们提出了一个NAORFB与所有聚乙二醇化，无金属，有机化合物作为电活性材料。聚乙二醇化吩噻嗪和聚乙二醇化紫精分别用作阴极电解液和阳极电解液。结合复合纳米多孔芳纶隔膜，全PEG化NAORFB具有出色的循环性能，每次循环的容量保持率为99.90%，平均库仑效率为99.7%。相比之下，使用半聚乙二醇化和非聚乙二醇化电解质的NAORFB由于非聚乙二醇化材料的交叉而显示出较差的循环能力。还对使用非聚乙二醇化或半聚乙二醇化材料的电池进行了扩展研究，以进行机理阐明。这项工作验证了NAORFB中的PEG化策略，以增强溶解性、可循环性和缓解交叉的整体性能。
Non-aqueous organic material-based redox flow batteries (NAORFBs) possess the advantage of using organic solvents to achieve high electrochemical potential. However, regardless of the great progress made in this regard in the past decade, further development has been restricted by the lack of stable electroactive organic materials and highly selective separators. Here, we present a NAORFB with all-PEGylated, metal-free, organic compounds as electroactive materials. PEGylated phenothiazine and PEGylated viologen are utilized as the catholyte and anolyte, respectively. Combined with a composite nanoporous aramid nanofiber separator, the all-PEGylated NAORFB presents outstanding cyclability, with a capacity retention of 99.90% per cycle and average coulombic efficiency of 99.7%. By contrast, NAORFBs using half-PEGylated and non-PEGylated electrolytes display inferior cyclability owing to the crossover of non-PEGylated materials. An extended investigation was also performed on the batteries using non-PEGylated or half-PEGylated materials for mechanistic elucidation. This work validates the PEGylation strategy in NAORFBs for enhanced overall performance with respect to solubility, cyclability, and alleviated crossover.