Thin-film composite membrane breaking the trade-off between conductivity and selectivity for a flow battery
Thin-film composite membrane breaking the trade-off between conductivity and selectivity for a flow battery
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薄膜复合膜打破了液流电池电导率和选择性之间的权衡
DOI：
10.1038/s41467-019-13704-2
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发表时间：
2020-01-07
影响因子：
16.6
通讯作者：
Li, Xianfeng
中科院分区：
文献类型：
--
作者：
Dai, Qing;Liu, Zhiqiang;Li, Xianfeng
同时具有高离子导电性和选择性的膜是高功率密度和低成本液流电池的关键，这对于可再生能源的广泛应用具有重要意义。离子选择性和电导率之间的平衡是离子导电膜的瓶颈。在本文中，一种薄膜复合膜与聚酰胺选择性层被发现打破了离子选择性和导电性之间的权衡，并显着提高了液流电池的功率密度。结果，具有薄膜复合膜的钒液流电池在260 mA cm（-2）的电流密度下实现了高于80%的能量效率，这是据我们所知有史以来报道的最高能量效率。结合实验和理论计算，我们认为高性能的质子转移是通过Grotthuss机理和Vehicle机理在亚1 nm的微孔中进行的。
A membrane with both high ion conductivity and selectivity is critical to high power density and low-cost flow batteries, which are of great importance for the wide application of renewable energies. The trade-off between ion selectivity and conductivity is a bottleneck of ion conductive membranes. In this paper, a thin-film composite membrane with ultrathin polyamide selective layer is found to break the trade-off between ion selectivity and conductivity, and dramatically improve the power density of a flow battery. As a result, a vanadium flow battery with a thin-film composite membrane achieves energy efficiency higher than 80% at a current density of 260 mA cm(-2), which is the highest ever reported to the best of our knowledge. Combining experiments and theoretical calculation, we propose that the high performance is attributed to the proton transfer via Grotthuss mechanism and Vehicle mechanism in sub-1 nm pores of the ultrathin polyamide selective layer.