High performance laboratory X-ray absorption spectroscopy system

高性能实验室X射线吸收光谱系统

• 批准号: 426693405
• 金额: --
• 依托单位: Technische Universität Clausthal
• 依托单位国家: 德国
• 项目类别: Major Research Instrumentation
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/426693405?language=en
• 关键词: performance; laboratory; ray; absorption; spectroscopy

Our objective in this proposal is to better understand the chemistry of amorphous structures in functional polymer materials and secondary resources. Polymer electrolyte membranes (PEMs), are an important part of many electrochemical units like Vanadium redox flow batteries (VRFB). They serve as unique ion conductors and ion barriers simultaneously. In VRFBs the PEM is ideally transporting protons and is impermeable for Vanadium ions. The cross over of Vanadium ions is a main reason for capacity fade in VRFBs. Though this phenomenon is well studied especially on Nafion, the transport of ions in the PEM is not yet understood. The chemistry inside of the mesoscopic, hydrated channels inside the membrane, which are formed by hydrophilic interactions of the sulfonyl-groups and water, is quite different from that of free water. Our specific aim is to identify chemical reactions and interactions which are contributing to Vanadium ion transport in the membrane e.g. interaction with the sulfonyl groups and reactions of Vanadium redox pairs. We study Nafion and novel PEMs which are less expensive and can be designed with variable characteristics e.g. gradient of cross linkers. The laboratory X-ray absorption spectrometer system (L-XAFS) will allow us to determine the oxidation state and the chemical surrounding of Vanadium ions directly in the hydrated membrane which is difficult to study other vice. The understanding we will have gained in the course of the project will enable us and others to develop more selective membranes. Additionally, we will work on a better understanding of the formation of amorphous and crystalline compounds in recycling slags. The longterm goal is to enable an economic way to retrieve critical elements from recycling slags. This can be achieved by synthesizing amorphous and crystalline compounds with the critical elements being enriched in engineered artificial minerals (EAMs). Only little is known on the formation and structure of amorphous components in slags. Our preliminary studies show that redox active elements like Manganese have a directive influence. While the formation of crystalline structures can be followed by X-ray diffraction, it is difficult to study the formation of amorphous structures. Our specific aim is to better understand the influence of Manganese and especially its valence on the formation of amorphous structures and EAMs in slags stemming from the recycling of Li-ion batteries. The L-XAFS allows us to investigate the identity of amorphous structure and with the appropriate experimental parameters also to investigate their formation. we expect to gain a fundamental understanding on this process which will be applicable also to other systems. Until now XAFS is nearly exclusively available at Synchrotron sources. New developments in X-ray optics and X-ray tubes enables now to perform a fast majority of the necessary analyses in the laboratory with the system which is subject to this proposal.

我们的目标是更好地了解功能聚合物材料和二次资源中无定形结构的化学。聚合物电解质膜（PEM）是许多电化学单元如钒氧化还原液流电池（VRFB）的重要组成部分。它们同时作为独特的离子导体和离子屏障。在VRFB中，PEM理想地传输质子并且对于钒离子是不可渗透的。钒离子的交换是VRFBs容量衰减的主要原因。虽然这种现象已经得到了很好的研究，特别是在Nafion上，但PEM中离子的传输还没有被理解。膜内的介观水合通道内的化学性质与自由水的化学性质完全不同，所述通道由磺酰基基团和水的亲水性相互作用形成。我们的具体目标是确定有助于膜中钒离子转运的化学反应和相互作用，例如与磺酰基的相互作用和钒氧化还原对的反应。我们研究了Nafion和新型PEM，它们价格较低，可以设计成具有可变特性，例如交联剂的梯度。实验室X射线吸收光谱仪系统（L-XAFS）将使我们能够直接测定水合膜中钒离子的氧化态和化学环境，这是难以研究其他副作用的。我们在项目过程中获得的理解将使我们和其他人能够开发出更具选择性的膜。此外，我们将努力更好地了解回收渣中无定形和结晶化合物的形成。长期目标是实现一种经济的方法，从回收炉渣中回收关键元素。这可以通过合成无定形和结晶化合物来实现，其中关键元素在工程人造矿物（EAM）中富集。渣中非晶态组分的形成和结构至今仍知之甚少。我们的初步研究表明，氧化还原活性元素，如锰有直接的影响。虽然晶体结构的形成可以通过X射线衍射来跟踪，但很难研究非晶结构的形成。我们的具体目标是更好地了解锰的影响，特别是它的价态对锂离子电池回收产生的炉渣中非晶结构和EAM的形成。L-XAFS使我们能够研究非晶结构的身份，并与适当的实验参数也调查他们的形成。我们希望对这一过程有基本的了解，这一过程也将适用于其他系统。到目前为止，XAFS几乎只在同步辐射源上可用。X射线光学和X射线管的新发展使我们能够在实验室中使用本提案所述的系统快速进行大多数必要的分析。