Crystal growth and electrochemistry of Lithium-based materials: Investigation of model systems for Li-ion batteries

该项目采用系统研究，以了解最先进的锂离子电池阴极材料的复杂结构和电子相图。我们将研究晶体生长参数并合成单晶模型材料，这些材料在结构，化学计量和尺寸方面进行了优化，我们将对其物理和化学性质进行表征。此外，我们将研究单晶沿着其主轴的电化学脱锂，以研究晶体结构，电化学性质和锂沿晶轴沿着扩散动力学之间的关系。特别是，我们将通过高压移动溶剂浮区技术（高达150 bar）合成LiMPO 4（M = Mn，Fe，Ni，（Mn，Ni），（Mn，Fe））和LiCoO 2单晶。随后，添加额外的掺杂剂（例如，（三）将引进。将详细分析和表征多晶进料棒以及单晶的完美性，并通过磁性，运输和热力学测量研究电子相图。此外，晶体将提供给优先计划，其中锂动力学，有序现象和结构将进行研究，例如通过NMR，硬X射线衍射和理论建模。注：最近批准的BMBF研究组03 SF 0340/LIB 2015旨在研究纳米级和单晶阴极材料应与SPP相关。研究小组将搬到海德堡大学。因此我申请了一台高压移动式溶剂浮区炉。

The project applies a systematic study in order to understand the complex structural and electronic phase diagrams of state-of-the-art cathode materials for Li-ion batteries. We will investigate the crystal growth parameters and synthesize single-crystalline model materials optimized regarding structure, stoichiometry, and size, and we will characterize them regarding their physical and chemical properties. In addition, we will study electrochemical delithiation of the single crystals along their main axes in order to investigate relations between crystal structure, electrochemical properties and kinetics of Li-diffusion along the crystal axis. In particular, we will synthesize LiMPO4, (M = Mn, Fe, Ni, (Mn,Ni), (Mn,Fe)), and LiCoO2 single crystals by means of the high-pressure traveling-solvent floating-zone technique (up to 150 bar). Later on, additional dopants (e.g., Si) will be introduced. The perfection of polycrystalline feed rods as well as single crystals will be analyzed and characterized in detail and the electronic phase diagrams will be investigated by means of magnetic, transport, and thermodynamic measurements. In addition, the crystals will be provided to the priority program where Li-kinetics, ordering phenomena, and structure will be studied, e.g. by NMR, hard x-ray diffraction, and theoretical modelling.Note: The recently granted BMBF-Research group 03SF0340/LIB2015 aiming at the investigation of nanoscaled and single-crystalline cathode materials shall be associated with the SPP. The research group will move to University of Heidelberg. I hence apply for a high-pressure travelingsolvent floating-zone furnace.