Salt cavern redox flow batteries with a large salt-cavern storing electrolyte are a promising large-scale energy storage technology. Here a low-cost iron/organic redox material system was proposed to explore salt cavern redox flow batteries. To avoid the formation of ferric hydroxide, ligand threonine was used to enhance the stability of the ferric ion in aqueous solution. Paired with a two electron viologen catholyte and saturated brine solution as supporting electrolyte, the battery delivered a high battery efficiency and cycling stability, 99% CE, 80% EE, and an average 99.5% capacity retention per cycle. The impressive battery performance provides a promising strategy for developing large-scale salt-cavern redox flow batteries.

中文翻译：

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铁/有机材料在盐穴支撑的氧化还原液流电池中的原卤溶液

具有大型盐穴存储电解质的盐穴氧化还原液流电池是一种有前途的大规模能量存储技术。在这里，提出了一种低成本的铁/有机氧化还原材料系统来探索盐穴氧化还原液流电池。为了避免形成氢氧化铁，使用配体苏氨酸来增强水溶液中铁离子的稳定性。与两个电子的紫罗兰阴极电解液和饱和盐水溶液作为支持电解质搭配使用，该电池可提供高电池效率和循环稳定性，99％的CE，80％的EE以及每个周期平均99.5％的容量保持率。令人印象深刻的电池性能为开发大型盐穴氧化还原液流电池提供了有希望的策略。