Membranes with fast and selective ion transport are widely used for water purification and devices for energy conversion and storage including fuel cells, redox flow batteries and electrochemical reactors. However, it remains challenging to design cost-effective, easily processed ion-conductive membranes with well-defined pore architectures. Here, we report a new approach to designing membranes with narrow molecular-sized channels and hydrophilic functionality that enable fast transport of salt ions and high size-exclusion selectivity towards small organic molecules. These membranes, based on polymers of intrinsic microporosity containing Tröger's base or amidoxime groups, demonstrate that exquisite control over subnanometre pore structure, the introduction of hydrophilic functional groups and thickness control all play important roles in achieving fast ion transport combined with high molecular selectivity. These membranes enable aqueous organic flow batteries with high energy efficiency and high capacity retention, suggesting their utility for a variety of energy-related devices and water purification processes.

中文翻译：

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亲水性微孔膜，用于选择性离子分离和流电池能量存储。

具有快速和选择性离子迁移的膜广泛用于水净化以及能量转换和存储的设备，包括燃料电池，氧化还原液流电池和电化学反应器。然而，设计具有明确的孔结构的具有成本效益的，易于处理的离子导电膜仍然具有挑战性。在这里，我们报告了一种设计具有窄分子大小通道和亲水功能的膜的新方法，该膜能够实现盐离子的快速运输和对小有机分子的高尺寸排阻选择性。这些膜基于含有Tröger碱或a胺肟基团的固有微孔性聚合物，证明了对亚纳米孔结构的精确控制，亲水性官能团的引入和厚度控制在实现快速离子迁移和高分子选择性方面都起着重要作用。这些膜使水性有机液流电池具有高能效和高容量保持能力，表明它们可用于各种与能源相关的设备和水净化工艺。