Abstract:

Vanadium flow battery (VFB) has received increasing attention in large-scale energy storage due to their attractive merits of large storage capacity, adjustable power and capacity, and no cross-contamination of redox-active materials. Commercialized perfluorosulfonic acid membranes are limited in VFB application due to the high cost and low ion selectivity. Therefore, nonperfluorinated polymer membranes have been comprehensively researched. So far, alternative membranes are facing challenges in an intrinsic trade-off between ion transport and selectivity. Meanwhile, the chemical stability of alternative membrane in strongly acidic and oxidizing condition for VFBs is also a challenge. It is the key to achieving high ion-selective transport and high stability to optimize ion-selective transport channels in the membrane on basic of the structure-performance relationship. The ion-selective transport channels based on traditional hydrophilic groups, size sieving effects and non-traditional hydrophilic groups were discussed, respectively. The current progress and problems of membrane were comprehensively overviewed, and the research directions of construction of ion-selective transport channels in membranes were pointed out for large-scale VFB application.

Key words: ion-selective transport channels, membrane, traditional hydrophilic group, size sieving effects, non-traditional hydrophilic group, vanadium flow battery

摘要：

全钒液流电池（VFB）具有存储容量大、功率和容量可调、活性物质无交叉污染等优点，在大规模储能领域受到广泛的关注。商业化全氟磺酸膜成本高、离子选择性低的问题，制约了VFB的大规模应用。低成本非氟膜的研究成为主要的研究方向。迄今为止，替代膜面临着离子传导率与选择性之间的权衡问题，同时在强酸性和氧化条件下的化学稳定性也是一个挑战。通过构效关系优化膜内的离子选择性传导通道，是实现高离子选择性传导和高稳定性的关键。本文对基于传统亲水基团的离子选择性传导通道、基于孔径筛分效应的离子选择性传导通道、基于非传统亲水基团的离子选择性传导通道进行分析研究，较为全面阐述了当前VFB膜研究取得的进展及目前面临的问题，并提出了膜内离子选择性传导通道构建的研究方向。

关键词: 离子选择性传导通道, 膜, 传统亲水基团, 孔径筛分, 非传统亲水基团, 全钒液流电池