Phase stability of alloy-type lithium storage anode materials

合金型储锂负极材料的相稳定性

• 批准号: 180081180
• 负责人: Professor Dr. Markus Rettenmayr (†)
• 金额: --
• 依托单位: Key Laboratory of Advanced Functional Materials
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/180081180?language=en
• 关键词: Phase; stability; alloy; type; lithium

In the present project, a systematic study will be carried out that provides coherent and extensive information about potential alloy systems for Li storage anodes in Li batteries. Three project partners combine theoretical competences in the Calphad method, the thermodynamics of nanomaterials and the combination of thermodynamics and kinetics during phase transformations, as well as experimental competences in the measurement of thermodynamic properties, production of nanomaterials and characterization of nanoscaled structures.The quaternary alloy system Li-Si-Sn-C with the respective subsystems Li-Si, Li-Sn, Li-Si-C and Li-Sn-C will be investigated/established using the Calphad method. Since nanostructuring is generally accepted as a strategy to achieve an increased cycling stability in Li batteries, the contribution of grain and phase boundaries to the phase stability in the alloy systems will be modeled on the basis of excess free energies as a function of structural length scales.On the experimental side, selected alloys will be cast as ingots and nanostructured by crushing, ball-milling and subsequent sintering in an SPS system. Nanostructuring will be carried out using unique experimental equipment in a closed system with essentially oxygenfree atmosphere. The nanostructured material will be thoroughly characterized. Focus will be to determine grain size distribution, phase distribution and orientation distribution in the Transmission Electron Microscope (TEM). For this, current TEM analysis methods will be further developed and extended to ultra fine grain sizes.With the phase diagrams, the comprehensive thermodynamic description and the tools developed in this project, an estimation of cycling stability and the prediction of Li storage capacity will be possible for a large range of compositions in the above mentioned alloy system, and promising materials for Li battery alloys will be identified.

在本项目中，将进行系统的研究，提供有关锂电池中锂存储阳极的潜在合金系统的连贯和广泛的信息。三个项目合作伙伴联合收割机结合了在Calphad方法、纳米材料热力学和相变过程中热力学和动力学结合方面的理论能力，以及在热力学性质测量、纳米材料生产和纳米尺度结构表征方面的实验能力。将使用Calphad方法研究/建立Li-Si-C和Li-Sn-C。由于纳米结构通常被认为是实现Li电池中增加的循环稳定性的策略，因此将基于作为结构长度尺度的函数的过量自由能来模拟合金系统中晶粒和相边界对相稳定性的贡献。在实验方面，将选定的合金铸造成铸锭并通过破碎进行纳米结构化，球磨和随后在SPS系统中烧结。纳米结构化将在基本无氧气氛的封闭系统中使用独特的实验设备进行。纳米结构材料将被彻底表征。重点是在透射电子显微镜（TEM）中确定粒度分布、相分布和取向分布。因此，目前的TEM分析方法将进一步发展并扩展到超细晶粒尺寸。借助相图、全面的热力学描述和本项目开发的工具，将有可能对上述合金体系中的大范围成分进行循环稳定性评估和锂储存容量预测，并将确定有前途的锂电池合金材料。