Zhi Liping, Liao Chenyi, Xu Pengcheng, Li Guohui, Yuan Zhizhang, Li Xianfeng
Division of Energy Storage, Dalian National Laboratory for Clean Energy Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Angew Chem Int Ed Engl. 2024 Dec 16;63(51):e202412559. doi: 10.1002/anie.202412559. Epub 2024 Oct 24.
Alkaline ferri/ferro-cyanide-based flow batteries are well suited for energy storage because of their features of high electrochemical activity, good kinetics and low material cost. However, they suffer from low energy density and poor temperature adaptability. The ferri/ferro-cyanide catholyte exhibits low solubility (0.4 M at 25 °C) in NaOH- or KOH-based supporting electrolyte and can easily form precipitates below room temperature. Here we report a lithium-based supporting electrolyte that significantly enhances the solubility of ferrocyanide. The use of LiOH intensifies the ion-dipole interaction between water molecules and solutes and cripples polarization among ferrocyanide ions. Thus, we have achieved a ferrocyanide-based catholyte of 1.7 M at 25 °C and of 0.8 M at -10 °C. A zinc-ferricyanide flow battery based on the lithium-based supporting electrolyte demonstrates a steady charge energy of ~72 Wh L at 25 °C, and maintains stable for ~4200 cycles (4200 hours). Furthermore, it remains stable for 800 cycles (800 hours) at -10 °C.
基于碱性铁氰化物/亚铁氰化物的液流电池因其具有高电化学活性、良好的动力学性能和低材料成本等特点，非常适合用于能量存储。然而，它们存在能量密度低和温度适应性差的问题。铁氰化物/亚铁氰化物阴极电解液在基于氢氧化钠或氢氧化钾的支持电解质中表现出低溶解度（25℃时约为0.4 M），并且在室温以下容易形成沉淀。在此，我们报道了一种锂基支持电解质，它能显著提高亚铁氰化物的溶解度。使用氢氧化锂增强了水分子与溶质之间的离子 - 偶极相互作用，并削弱了亚铁氰化物离子之间的极化作用。因此，我们在25℃时获得了浓度为1.7 M、在 - 10℃时为0.8 M的基于亚铁氰化物的阴极电解液。基于锂基支持电解质的锌 - 铁氰化物液流电池在25℃时展示出约72 Wh L的稳定充电能量，并在约4200次循环（约4200小时）内保持稳定。此外，它在 - 10℃时也能在约800次循环（约800小时）内保持稳定。
