"Cation/anion with co-solvation" type high-voltage aqueous electrolyte enabled by strong hydrogen bonding
"Cation/anion with co-solvation" type high-voltage aqueous electrolyte enabled by strong hydrogen bonding
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DOI：
10.1016/j.nanoen.2022.107377
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发表时间：
2022-05-23
期刊：
影响因子：
17.6
通讯作者：
Yan, Xingbin
中科院分区：
文献类型：
--
作者：
Hou, Ruilin;Wang, Yue;Yan, Xingbin
水溶液是各种电化学应用中重要的电荷传输介质。然而，水的分裂严重限制了电解液的工作电压。因此，进一步拓宽电解液的电化学稳定窗口具有重要意义。基于卤素阴离子(F-)的高电荷密度和高电负性，我们提出了一种“阳离子/阴离子共溶剂型”的16mKF水溶液电解液，其电导率可达196ms cm(-1)，基于不锈钢网的3.4V电流计和基于铝金属电极的6.72V电流计远远高于目前报道的最高电导率。这种优良的特性归因于F-离子与水分子在高浓度下形成了强烈的氢键。这一工作有助于从分子水平上理解阴离子在水溶液中的重要作用，为设计理想的高压水溶液提供新的途径。
Aqueous electrolytes are important charge transport media in various electrochemical applications. However, the water splitting seriously limits the operation voltage of aqueous electrolytes. Thus, further widening the electrochemical stability window (ESW) of aqueous electrolytes is great of importance. Here, based on the high charge density and high electro-negativity of halogen anions (F-), we proposed a "cation/anion with co-solvation" type 16 m KF aqueous electrolyte that can achieve a high conductivity of 196 mS cm(-1), a record 3.4 V ESW based on stainless steel mesh and even 6.72 V ESW based on Al metal electrode that is much higher than the highest value currently reported. Such excellent feature is attributed to the strong hydrogen bonds between the F anions and the water molecules at high concentrations. This work is helpful to provide a new path for design of ideal high-voltage aqueous electrolytes and to understand the important role of anions in aqueous electrolytes at the molecular level.