Zhi Liping, Liao Chenyi, Xu Pengcheng, Sun Fusai, Fan Fengtao, 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, 116023, Dalian, China.
University of Chinese Academy of Sciences, 100049, Beijing, China.
Angew Chem Int Ed Engl. 2024 Jul 8;63(28):e202403607. doi: 10.1002/anie.202403607. Epub 2024 Jun 3.
Alkaline zinc-ferricyanide flow batteries are efficiency and economical as energy storage solutions. However, they suffer from low energy density and short calendar life. The strongly alkaline conditions (3 mol L OH) reduce the solubility of ferri/ferro-cyanide (normally only 0.4 mol L at 25 °C) and induce the formation of zinc dendrites at the anode. Here, we report a new zinc-ferricyanide flow battery based on a mild alkalescent (pH 12) electrolyte. Using a chelating agent to rearrange ferri/ferro-cyanide ion-solvent interactions and improve salt dissociation, we increased the solubility of ferri/ferro-cyanide to 1.7 mol L and prevented zinc dendrites. Our battery has an energy density of ~74 Wh L at 60 °C and remains stable for 1800 cycles (1800 hours) at 0 °C and for >1400 cycles (2300 hours) at 25 °C. An alkalescent zinc-ferricyanide cell stack built using this alkalescent electrolyte stably delivers 608 W of power for ~40 days.
碱性锌铁氰化物液流电池作为储能解决方案，具有高效且经济的特点。然而，它们存在能量密度低和日历寿命短的问题。强碱性条件（3 mol·L⁻ OH⁻）会降低铁氰化物/亚铁氰化物的溶解度（在25°C时通常仅为0.4 mol·L⁻），并在阳极诱导锌枝晶的形成。在此，我们报道了一种基于弱碱性（pH 12）电解质的新型锌铁氰化物液流电池。通过使用螯合剂重新排列铁氰化物/亚铁氰化物离子与溶剂的相互作用并改善盐的解离，我们将铁氰化物/亚铁氰化物的溶解度提高到了1.7 mol·L⁻，并防止了锌枝晶的形成。我们的电池在60°C时的能量密度约为74 Wh·L⁻，在0°C下可稳定运行1800次循环（1800小时），在25°C下可稳定运行超过1400次循环（2300小时）。使用这种弱碱性电解质构建的弱碱性锌铁氰化物电池组可稳定输出608 W的功率约40天。
