The development of electroactive organic materials for use in aqueous redox flow battery (RFB) electrolytes is highly attractive because of their structural flexibility, low cost and sustainability. Here, we report on a highly reversible anthraquinone-based anolyte (1,8-dihydroxyanthraquinone, 1,8-DHAQ) for alkaline aqueous RFB applications. Electrochemical measurements reveal the substituent position of hydroxyl groups for DHAQ isomers has a significant impact on the redox potential, electrochemical reversibility and water-solubility. 1,8-DHAQ shows the highest redox reversibility and rapidest mass diffusion among five isomeric DHAQs. The alkaline aqueous RFB using 1,8-DHAQ as the anolyte and potassium ferrocyanide as the catholyte yields open-circuit voltage approaching 1.1 V and current efficiency and capacity retention exceeding 99.3% and 99.88% per cycle, respectively. This aqueous RFB produces a maximum power density of 152 mW cm⁻² at 100% SOC and 45 °C. Choline hydroxide was used as a hydrotropic agent to enhance the water-solubility of 1,8-DHAQ. 1,8-DHAQ has a maximum solubility of 3 M in 1 M KOH with 4 M choline hydroxide.

用于水性氧化还原液流电池（RFB）电解质的电活性有机材料的开发由于具有结构灵活性，低成本和可持续性而极具吸引力。在这里，我们报告了一种碱性碱性RFB应用的高度可逆的蒽醌基阳极电解液（1,8-二羟基蒽醌，1,8-DHAQ）。电化学测量表明DHAQ异构体的羟基取代基位置对氧化还原电势，电化学可逆性和水溶性具有重大影响。1,8-DHAQ在五个异构DHAQ中显示出最高的氧化还原可逆性和最快的质量扩散。碱性水溶液RFB使用1,8-DHAQ作为阳极电解液，使用亚铁氰化钾作为阴极电解液，其开路电压接近1.1 V，电流效率和容量保持率分别超过99.3％和99。每个周期分别为88％。这种水性RFB产生的最大功率密度为152 mW cm^-2在100％SOC和45°C下。氢氧化胆碱被用作水溶助剂，以增强1,8-DHAQ的水溶性。1,8-DHAQ在1 M KOH和4 M胆碱中的最大溶解度为3M。