Spouted bed processing for structuring of conductive battery hetero-aggregates

在本项目中，将建立一种新型的喷床干涂工艺，该工艺能够制备由三种材料组成的异质聚集体，适用于全固态电池。这些材料的主要粒径从40纳米到1微米左右，将由布朗瑞克的Kwade教授的工作组在SPP中提供，类似于生产高性能电池的候选材料。复合材料将在喷淋床内通过混合材料和由于凝聚力产生集料而形成。这种新方法的主要优点是避免了对健康有害的溶剂，在喷射床过程中作用的高力，同时具有扩大规模的潜力。为了能够同时处理喷床中的三种固体流，将评估两种新的、不同的固体注入方法：中心喷嘴式注入和与流化气体一起注入。因此，将重建现有的小型喷床工厂，然后将生产第一批复合材料，并对其机械性能和组成进行评估。特别是聚集体的稳定性以及聚集体内部不同材料的分布是决定其在固态电池中的后续应用的关键因素。复合材料的电化学性能，特别是电导率和离子电导率以及化学稳定性将在布伦瑞克进行研究。通过收到合作伙伴的反馈，我们将改变工艺参数（例如固体质量流量、气体速度和床质量），从而对工艺参数和骨料结构之间的关系有一个基本的了解，并生产出具有最佳性能的骨料，用于全固态电池。这项工作的基础将是评估和扩展在干涂层过程中作用的特定力的现有理论模型。通过实验和模拟的方法，在喷射床过程中作用在颗粒上的力（内聚力、破碎力、压缩力）将通过实验和模拟进行分析。工厂内的气体流动将通过CFD建模来确定颗粒轨迹的速度，这表明作用在颗粒上的最大应力。有了这些知识，就可以在DEM中模拟特定的相互作用。这项工作的目标是通过数值描述微过程来预测干涂层喷射过程中的行为。之后，将有可能通过人口平衡来描述这一过程，这反过来将用于创建一个用于流程图模拟的理论模型（Dyssol），并为该过程的进一步耦合CFD-DEM模拟奠定基础，该模拟计划在第二个资助期进行。

In this project, a novel spouted bed dry coating process will be established, which is able to fabricate hetero aggregates consisting of three materials, that are suitable for the use in all-solid-state-batteries. The materials, with primary particle sizes ranging from 40 nm to around 1 µm, will be provided within the SPP by the working group of Prof. Kwade in Braunschweig and resemble candidates for the production of high-performance batteries. The composites will be formed inside the spouted bed by mixing the materials and creating aggregates due to the cohesive forces. The main advantage of this novel method are the avoidance of dangerous-to-health solvents, high forces acting in spouted bed processes and at the same time a scale-up potential. To be able to handle three solid streams in the spouted bed simultaneously, two new, different approaches regarding the injection of solids will be evaluated: a central nozzle-like injection and an injection together with the fluidization gas. Therefore, an existing miniaturized spouted bed plant will be reconstructed and afterwards the first composites will be produced, which will be evaluated regarding their mechanical properties and their composition. Especially the stability of the aggregates as well as the distribution of the different materials inside the aggregate are key factors, which determine the later application in solid-state batteries. The electro-chemical properties of the composites, especially the electric and ionic conductivity as well as the chemical stability will be investigated in Braunschweig. By receiving feedback from our partners, the process parameters (e.g. solids mass flows, gas velocities and bed mass) will be changed, to achieve a fundamental understanding of the relationship between process parameters and aggregate structure and produce aggregates with the best properties for the use in all-solid-state batteries. The foundation of this work will be the evaluation and expansion of existing theoretical models for interparticular forces acting during dry coating processes. By using experimental as well simulative methods, the forces (cohesion, breakage, compression) acting on particles during a spouted bed process will be analysed experimentally as well as by simulation. The gas flow inside the plant will be modelled by CFD to determine the velocities of the trajectories of the particles, which indicate the highest stresses acting on the particles. With this knowledge it is possible to simulate the particular interactions in DEM. Goal of this work is the ability to predict the behaviour during a dry coating spouted process by describing the microprocesses numerically. Afterwards, it will be possible to describe the process by population balances, which in turn will be used to create a theoretical model for the use in flowsheet simulations (Dyssol) and lay the foundation for further coupled CFD-DEM simulations of the process, which are planned for the second funding period.