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的一个核心问题是合成新的无定形李固体，以及在高压高温治疗时对锂迁移率变化的研究。该项目的主要目标是通过实验确定传输属性和以下参数之间的关系： - 组成和结构类型 - 排序状态 - 压实程度 - 锂的局部环境，在第一阶段，我们将重点放在系统LI2O -AL2O3 -SIO2中无晶化合物的合成，压实和表征上。使用阻抗光谱和NMR确定锂迁移率。遵循这种方法，我们希望研究组成结构状态和粒径对锂在无定形粉末压力/温度处理期间所选系统的运输的影响。我们选择两个代表更多离子的模型系统（例如Litao3 UND LINBO3）和更多共价材料（例如LifePo4或Limgpo4，后者分别具有MG具有单个氧化态）。该项目的目的是将体积和晶界扩散对颗粒单相系统中的液传输的影响分离，并研究压实过程中这些传输特性的变化。为此，我们想应用项目第一阶段开发的新活塞缸机器。该方法允许在压实温度和压力功能上直接测量阻抗光谱和体积变化。使用具有控制湿度和氧气压力的大气，在开始压缩之前，可以在运行温度下预先调节粉末。我们期望H2O对压实动力学有重大影响，进而对锂迁移率产生重大影响。微型分析和光谱法将在压实后对结构和拓扑修饰有洞察力。 NMR测量值，如果可能的话，机械放松光谱将提供有关起始材料和实验后样品中锂迁移率的信息。