Effect of pressure on transport properties of granular lithium ion conductors

压力对粒状锂离子导体输运性能的影响

• 批准号: 166931436
• 负责人: Professor Dr. Harald Behrens
• 金额: --
• 依托单位: Arbeitsgruppe Anorganische Chemie/ Festkörperchemie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/166931436?language=en
• 关键词: Effect; pressure; transport; properties; granular

A central issue of TP is the synthesis of new amorphous Li-bearing solids and the investigation of the change in lithium mobility upon high pressure - high temperature treatment. A primary goal of the project is to determine experimentally the relationships between transport properties and the following parameters: - composition and structure type - state of ordering - degree of compaction - local environment of lithium In the first period we have focussed on the synthesis, compaction and characterization of amorphous compounds in the system Li2O-Al2O3-SiO2. Lithium mobility was determined using impedance spectroscopy and NMR. Following this approach we want to study the influence of composition structural state and particle size on the transport of lithium for selected systems in situ during pressure/temperature treatment of amorphous powders. We choose two model systems representing more ionic (e.g., LiTaO3 und LiNbO3) and more covalent materials (e.g., LiFePO4 or LiMgPO4, the latter one has the advantage that Mg has a single oxidation state), respectively. The aim of the project is to separate effects of volume and grain boundary diffusion on Li-transport in granular single phase systems and to investigate the change of theses transport properties during compaction. For doing so, we want to apply the new piston cylinder apparatus which was developed during the first period of the project. The method allows direct measurement of impedance spectra and volume changes during compaction in function of temperature and pressure. Using an atmosphere with controlled humidity and oxygen partial pressure, the powders can be pre-conditioned at run temperature before starting compression. We expect in particular that H2O has major impact on compaction kinetics and in turn on lithium mobility. Microanalytical and spectroscopic methods will give insights to structural and topological modifications upon compaction. NMR measurements and, if possible, mechanical relaxation spectroscopy will provide information about lithium mobility in starting materials and post-experimental samples.

TP 的一个中心问题是新型非晶态含锂固体的合成以及高压高温处理后锂迁移率变化的研究。该项目的主要目标是通过实验确定输运特性与以下参数之间的关系： - 成分和结构类型 - 有序状态 - 压实程度 - 锂的局部环境 在第一阶段，我们重点关注合成、压实Li2O-Al2O3-SiO2 体系中非晶态化合物的表征及表征。使用阻抗谱和NMR测定锂迁移率。按照这种方法，我们想要研究在非晶粉末的压力/温度处理过程中，成分结构状态和粒度对选定系统的锂传输的影响。我们选择两个模型系统，分别代表更多离子（例如，LiTaO3 和 LiNbO3）和更多共价材料（例如，LiFePO4 或 LiMgPO4，后者具有 Mg 具有单一氧化态的优点）。该项目的目的是分离体积和晶界扩散对颗粒单相系统中锂传输的影响，并研究压实过程中这些传输特性的变化。为此，我们希望应用在项目第一阶段开发的新型活塞缸装置。该方法允许直接测量压实过程中阻抗谱和体积随温度和压力的变化。使用湿度和氧分压受控的气氛，可以在开始压缩之前在运行温度下对粉末进行预处理。我们特别预计 H2O 对压实动力学产生重大影响，进而对锂迁移率产生重大影响。微观分析和光谱方法将深入了解压实时的结构和拓扑变化。核磁共振测量和机械弛豫光谱（如果可能）将提供有关起始材料和实验后样品中锂迁移率的信息。