Unique ion rectification in hypersaline environment: A high-performance and sustainable power generator system
Unique ion rectification in hypersaline environment: A high-performance and sustainable power generator system
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高盐环境中独特的离子整流：高性能且可持续的发电机系统
DOI：
10.1126/sciadv.aau1665
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发表时间：
2018
期刊：
影响因子：
13.6
通讯作者：
Lei Jiang
中科院分区：
文献类型：
--
作者：
Xuanbo Zhu;Junran Hao;Bin Bao;Yahong Zhou;Haibo Zhang;Jinhui Pang;Zhenhua Jiang;Zhenhua Jiang;Lei Jiang
离子选择性 Janus 膜在高盐溶液中具有单向离子传输，可实现有效的渗透能转换。膜科学的发展在收集渗透力方面发挥着基础作用，渗透力被认为是未来的清洁和可再生能源。然而，现有的膜设计无法应对低转换效率和功率密度。理论预测，具有离子二极管型电流的 Janus 膜将是最有效的材料。 Therefore, rectified ionic transportation in a hypersaline environment (the salt concentration is at least 0.5 M in sea) is highly desired, but it still remains a challenge.在这里，我们展示了一种创建基于 Janus 三维 (3D) 多孔膜的渗透发电机系统的通用策略。通过复合两种离聚物获得了表面电荷密度和孔隙率可调的Janus膜。在电场或化学梯度下，Janus 膜在高盐环境下具有离子电流整流特性和阴离子选择性。实验和理论计算表明，丰富的表面电荷和窄的孔径分布有利于这种在高盐溶液中独特的离子传输行为。因此，该膜基发电机的输出功率密度达到2.66 W/m2（混合海水和河水），在500倍盐度梯度（即将盐湖流入河水）时高达5.10 W/m2。此外，由一系列膜连接而成的发电机可以为计算器供电120小时，电流没有明显下降，证明了其优异的物理和化学稳定性。因此，我们相信这项工作增进了对流体传输和材料设计作为高性能能量转换发生器范例的基本理解。
Ion-selective Janus membranes with one-way ionic transport in hypersaline solution approach efficient osmotic energy conversion. The development of membrane science plays a fundamental role in harvesting osmotic power, which is considered a future clean and renewable energy source. However, the existing designs of the membrane cannot handle the low conversion efficiency and power density. Theory has predicted that the Janus membrane with ionic diode–type current would be the most efficient material. Therefore, rectified ionic transportation in a hypersaline environment (the salt concentration is at least 0.5 M in sea) is highly desired, but it still remains a challenge. Here, we demonstrate a versatile strategy for creating a scale-up Janus three-dimensional (3D) porous membrane–based osmotic power generator system. Janus membranes with tunable surface charge density and porosity were obtained by compounding two kinds of ionomers. Under electric fields or chemical gradients, the Janus membrane has ionic current rectification properties and anion selectivities in a hypersaline environment. Experiments and theoretical calculation demonstrate that abundant surface charge and narrow pore size distribution benefit this unique ionic transport behavior in high salt solution. Thus, the output power density of this membrane-based generator reaches 2.66 W/m2 (mixing seawater and river water) and up to 5.10 W/m2 at a 500-fold salinity gradient (i.e., flowing salt lake into river water). Furthermore, a generator, built by connecting a series of membranes, could power a calculator for 120 hours without obvious current decline, proving the excellent physical and chemical stabilities. Therefore, we believe that this work advances the fundamental understanding of fluid transport and materials design as a paradigm for a high-performance energy conversion generator.