An overview of amphoteric ion exchange membranes for vanadium redox flow batteries

Lei Liu¹，Chao Wang¹，Zhenfeng He²，Rajib Das^3,4，Binbin Dong⁵，Xiaofeng Xie⁶，Zhanhu Guo³

1. College of Materials Science and Engineering, North University of China2. School of Chemical Engineering and Technology, North University of China3. Integrated Composites Laboratory (ICL), Department of Chemical & Biomolecular Engineering, University of Tennessee5. Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education, National Engineering Research Center for Advanced Polymer Processing Technology, (Zhengzhou University)6. Institute of Nuclear and New Energy Technology, Tsinghua University

摘 要：Vanadium redox flow battery（VRB）,as the most promising large-scale electrical energy storage units,has attracted extensive attention.Amphoteric ion exchange membrane（AIEM）,as the core part of VRB,separates electrolyte on both sides of electrolytic tank and conducts H⁺.The AIEM with cation and anion groups possesses excellent performances,such as high ion conductivity（σ）,low vanadium ion permeability（Pvn+）,relative stability and low cost.However,the performance of AIEM directly depends on the chemical structure of polymers.In addition to ensuring foundational physical performance,ion selectivity of AIEM is significant since the crossover of vanadium ion with various valences may reduce the battery capacity.In this paper,AIEMs for VRB and their chemical structures as well as synthesis approaches to realize all kinds of high-performing AIEMs are reviewed.The current trend and future direction of prospective materials for the VRB separators are documented in detail as well.

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