High-volumetric-capacity and long-lifetime aqueous organic redox flow batteries (AORFBs) have received considerable attention for electrochemical energy storage. Here, we report a six-electron transfer π-conjugated heteroaromatic hexaazatrinaphthalene tricarboxylic acid (HATNTA) as a promising anolyte for AORFBs. HATNTA, synthesized by a straightforward and scalable one-step condensation reaction of cyclic carbonyl molecules, can undergo a reversible three-step six-electron redox process of -0.69, -0.87, and -0.94 V (versus Ag/AgCl) at pH=14. The redox reactions of HATNTA are unveiled by combining ultraviolet-visible spectrophotometry and density functional theory calculations. When paired with ferrocyanide catholyte, HATNTA-based AORFB with 1.5 M electron concentration exhibits high open-circuit voltage of 1.24 V, impressive specific capacity of 37.2 Ah L⁻¹, high output power density of 238 mW cm⁻² and superior cycling stability with a capacity fade rate of 0.021% per cycle. The outstanding battery performance substantiates that multi-redox HATNTA breaks a novel pathway to develop advanced AORFBs for large-scale energy storage.

高容量和长寿命的水系有机氧化还原液流电池 (AORFB) 在电化学储能领域受到了广泛关注。在这里，我们报告了六电子转移 π-共轭杂芳族六氮杂萘三羧酸 (HATNTA) 作为 AORFB 的有前途的阳极电解液。HATNTA 由环状羰基分子通过简单且可扩展的一步缩合反应合成，在 pH= 14. 通过结合紫外-可见分光光度法和密度泛函理论计算揭示了 HATNTA 的氧化还原反应。当与亚铁氰化物阴极电解液配对时，具有 1.5 M 电子浓度的基于 HATNTA 的 AORFB 表现出 1.24 V 的高开路电压，L ^{-1 、238 mW cm -2}的高输出功率密度和出色的循环稳定性，每个循环的容量衰减率为 0.021%。出色的电池性能证实，多氧化还原 HATNTA 开辟了一条开发用于大规模储能的先进 AORFB 的新途径。