Spectroscopic investigations of the fouling process on Nafion membranes in vanadium redox flow batteries
Spectroscopic investigations of the fouling process on Nafion membranes in vanadium redox flow batteries
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DOI：
10.1016/j.memsci.2010.10.018
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发表时间：
2011-01-01
影响因子：
9.5
通讯作者：
Hu, Jianzhi
中科院分区：
文献类型：
--
作者：
Vijayakumar, M.;Bhuvaneswari, M. S.;Hu, Jianzhi
Nafion膜是氧化还原液流电池中的关键部件，其被广泛研究用于电网规模的能量存储。然而，人们对氧化还原液流电池相关工作环境中膜材料的基本性质的理解非常有限。本文介绍了X射线光电子能谱（XPS），核磁共振（NMR）光谱和紫外/可见光谱的分析结果的全钒氧化还原液流电池中使用的Nafion-117膜。XPS研究揭示了钒阳离子在表面积累的化学身份和环境。另一方面，O-17 NMR测量探索了Nation主体部分内扩散的钒阳离子的性质，并显示了阳离子和宿主膜的化学键合。F-19 NMR表明，基本的Nafion结构没有被扩散到内部的钒阳离子改变。基于这些光谱研究，扩散的钒阳离子在Nafion膜的化学身份和环境进行了讨论。这项研究揭示了钒氧化还原液流电池中膜材料性能退化的起源的重要信息，并为如何改善储能装置的化学和性能提供了线索。(C)2010 Elsevier B. V.保留所有权利。
The Nation membrane is a critical component in redox flow batteries, which are widely investigated for grid-scale energy storage. However, there is very limited understanding of the fundamental properties of the membrane materials in the working environment relevant to redox flow batteries. This paper presents results of the analysis of the Nafion-117 membrane used in a vanadium redox flow battery by X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR) spectroscopy, and ultraviolet/visible spectroscopy. The XPS study reveals the chemical identity and environment of vanadium cations accumulated at the surface. On the other hand, the O-17 NMR measurement explores the nature of the diffused vanadium cations inside the bulk part of the Nation and shows the chemical bonding of cations and the host membrane. The F-19 NMR shows that the basic Nafion structure is not altered by the vanadium cations diffused inside. Based on these spectroscopic studies, the chemical identity and environment of the diffused vanadium cations in the Nafion membrane are discussed. This study reveals important information on the origin of performance degradation of the membrane materials in vanadium redox flow batteries and provides clues on how to improve the chemistry and properties of the energy storage devices. (C) 2010 Elsevier B.V. All rights reserved.