权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Li Diffusion in Lithium Silicon Compounds

Li在锂硅化合物中的扩散

基本信息

批准号：
316931911
负责人：
Professor Dr. Harald Schmidt
金额：
--
依托单位：
Institut für Metallurgie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/316931911?language=en
关键词：
Li Diffusion Lithium Silicon Compounds

项目摘要

Topic of the present proposal is the realization of the first systematic lithium tracer diffusion investigations in the system lithium-silicon (LixSi). This is of relevance for a fundamental understanding of kinetic processes at negative electrode materials in lithium-ion batteries for optimized charging times, power densities and maximum capacity. Further it is important to further develop a methodology, not very widely used in the area of Li diffusion, using an interesting model system. The experiments will be carried out on Li¬¬xSi samples as a function of Li concentration x, temperature, annealing time, and production method (sputter deposition, electrochemically). For this, different model systems in form of 6LixSi/7LixSi isotope heterostructures will be deposited on silicon substrates by ion-beam sputtering. Complementary investigations on electrochemically lithiated silicon layers will complete the experiments and identify the differences. For isotope selective analysis, secondary ion mass spectrometry (SIMS) in depth profile mode and/or alternatively in line scan mode will be used. This will allow a quantification of diffusivities between 10-10 and 10-23 m2/s. Diffusivities will be measured in a range between room temperature and 500 °C as a function of temperature. If the diffusivities follow the Arrhenius law, the activation enthalpy of diffusion will determined and analysed concerning different diffusion mechanisms in the framework of literature. The results should be compared to electrochemical GITT measurements. The results should be analysed in a comparative way.

本提案的主题是实现系统锂-硅（LixSi）中的第一个系统的锂示踪剂扩散研究。这对于从根本上理解锂离子电池中负极材料的动力学过程以优化充电时间、功率密度和最大容量具有重要意义。此外，重要的是进一步开发一种方法，使用有趣的模型系统，在Li扩散领域中不被广泛使用。实验将在Li xSi样品上进行，作为Li浓度x、温度、退火时间和生产方法（溅射沉积，电化学）的函数。为此，将通过离子束溅射在硅衬底上沉积6LixSi/7 LixSi同位素异质结构形式的不同模型系统。对电化学锂化硅层的补充研究将完成实验并确定差异。对于同位素选择性分析，将使用深度剖面模式和/或线扫描模式的二次离子质谱法（西姆斯）。这将允许在10-10和10-23 m2/s之间量化扩散率。将在室温至500 °C的范围内测量扩散率随温度的变化。在扩散系数服从阿耳忒弥斯定律的情况下，在文献的框架内，针对不同的扩散机制，对扩散活化焓进行了测定和分析。应将结果与电化学GITT测量结果进行比较。应以比较的方式分析结果。