Investigations on transfer of water and vanadium ions across Nafion membrane in an operating vanadium redox flow battery
Investigations on transfer of water and vanadium ions across Nafion membrane in an operating vanadium redox flow battery
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DOI：
10.1016/j.jpowsour.2009.08.041
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发表时间：
2010-02-01
影响因子：
9.2
通讯作者：
Luo, Qingtao
中科院分区：
文献类型：
--
作者：
Sun, Chenxi;Chen, Jian;Luo, Qingtao
测量了钒离子在钒氧化还原液流电池（VRFB）中穿过Nafion 115（Dupont）的扩散系数，发现其顺序为V2+ > VO 2 + > VO 2 + > V3+。研究发现，在自放电过程和充放电循环中，正、负电解液中钒离子浓度的差异是引起钒离子跨膜迁移的主要原因。在自放电过程中。水的转移包括钒离子与结合水的转移和质子与拖曳水的相应转移以平衡电荷，以及由渗透驱动的水的转移。在这种情况下，大约75%的水净转移是由渗透引起的。在充电-放电循环中，除了在自放电情况下提到的那些，在用于形成内部电路的电极反应期间质子与被拖曳的水穿过膜的转移在水转移中起关键作用。但在长期的充放电循环中。水向+VE的净转移是由钒离子与结合水的转移和渗透驱动的水转移引起的。皇冠版权所有（C）2009年出版的爱思唯尔B. V.保留所有权利。
Diffusion coefficients of the vanadium ions across Nafion 115 (Dupont) in a vanadium redox flow battery (VRFB) are measured and found to be in the order of V2+ > VO2+ >VO2+ > V3+. It is found that both in self-discharge process and charge-discharge cycles, the concentration difference of vanadium ions between the positive electrolyte (+ve) and negative electrolyte (-ve) is the main reason causing the transfer of vanadium ions across the membrane. In self-discharge process. the transfer of water includes the transfer of vanadium ions with the bound water and the corresponding transfer of protons with the dragged water to balance the charges, and the transfer of water driven by osmosis. In this case, about 75% of the net transfer of water is caused by osmosis. in charge-discharge cycles, except those as mentioned in the case of self-discharge, the transfer of protons with the dragged water across the membrane during the electrode reaction for the formation of internal electric circuit plays the key role in the water transfer. But in the long-term cycles of charge-discharge. the net transfer of water towards +ve is caused by the transfer of vanadium ions with the bound water and the transfer of water driven by osmosis. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.