Polymer electrolyte membranes (PEM) for vanadium redox flow batteries

全钒氧化还原液流电池用聚合物电解质膜（PEM）

• 批准号: 411688235
• 负责人: Professorin Dr. Sabine Beuermann
• 金额: --
• 依托单位: Institut für Leichtbau und Kunststofftechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/411688235?language=en
• 关键词: Polymer; electrolyte; membranes; PEM; vanadium

The amount of energy from renewable sources will increase in Germany in the upcoming years. Thus, storage systems for this fluctuating energy are of high importance. One possibility to store energy is the use of redox-flow-batteries (RFB), which are easy to scale. They allow for storage of electric energy in a liquid rechargeable electrolyte. Vanadium based systems (VRFB) are particularly interesting, since vanadium ions are present on both sides of the membrane in the electrochemical cell. While cross-over of vanadium ions in the other electrolyte half-cell will lead to a lowering of the energy density irreversible damage of the system due to contamination does not occur. Frequently, polymer electrolyte membranes (PEM) are used as separator in VRFBs. Particularly important is Nafion, which is a sulfonated fluoropolymer. Despite the fact that Nafion is used in a number of commercial applications, there are some shortcomings associated with Nafion and the development of new PEM materials with superior properties is of high importance. Within the interdisciplinary project novel PEM materials will be developed on the basis of commercially available fluoropolymer films and fabrics serving as scaffold. The radiation-induced activation of the fluoropolymers is followed by a graft copolymerization to incorporate functional groups allowing for sulfonation into the material. The influence of the irradiation conditions on radical type and concentration and subsequently on the polymerization is studied in detail. After sulfonation the PEMs are electrochemically characterized and application tests in VRFBs are performed. Important aspects to be addressed are high conductivity and prevention of cross-over. The experimental results constitute the basis for establishing a correlation of process, polymer, structure and the PEM properties. Moreover, the experiments are accompanied by modelling, e.g., with respect to optimization of the polymerization process and description of mass transfer through the membrane.

在接下来的几年里，德国可再生能源的数量将会增加。因此，这种波动能量的存储系统非常重要。储存能量的一种可能性是使用氧化还原液流电池(RFB)，这种电池很容易扩展。它们允许在液体可充电电解液中存储电能。基于钒的体系(VRFB)特别有趣，因为在电化学电池中，钒离子存在于膜的两侧。而钒离子在另一电解液半电池中的交叉会导致能量密度的降低，不会发生因污染而对系统造成的不可逆破坏。在VRFB中，经常使用聚合物电解质膜(PEM)作为隔膜。尤其重要的是Nafion，它是一种磺化的氟聚合物。尽管Nafion被用于许多商业应用，但与Nafion相关的一些缺点，开发具有优异性能的新型PEM材料具有非常重要的意义。在跨学科项目中，将在商业上可获得的氟聚合物薄膜和用作支架的织物的基础上开发新型的PEM材料。辐射诱导的氟聚合物活化之后是接枝共聚，以将允许磺化的官能团加入到材料中。详细研究了辐照条件对自由基类型和浓度的影响，进而对聚合反应的影响。磺化后的PEMS进行了电化学表征，并在VRFB中进行了应用试验。需要解决的重要方面是高传导性和防止交叉。实验结果为建立工艺、聚合物、结构与PEM性能之间的关联奠定了基础。此外，实验还伴随着建模，例如，关于聚合过程的优化和通过膜的传质描述。