Ann-Kathrin Wurba, M.Sc.

A critical process step within the liquid composite moulding constitutes in the preforming of two-dimensional textile material into a near-net-shape and load-capable fibre structure by stamp forming. This paper presents fundamental material experiments on the shearing behaviour, bending properties and friction behaviour considering the binder quantity and forming temperature. In addition, the influence of the process time on the resulting stability of the preform is examined. The findings indicate that the quantity of the binder as well as the forming temperature and the process time have a great influence on the preform quality.

Lithium-ion battery cells will dominate the market in the next 10 years. However, the use of certain materials as cobalt is a critical issue today and is constantly being reduced. Sodium-ion batteries are an alternative, which has already been researched on a laboratory scale. Increasing of the individual production steps are serious bottlenecks for bringing basic cell concepts into application. Within this paper a systematic investigation of parameters influencing the producibility for sodium-ion battery cells will be taken into account. For this purpose, the characteristic process variables and challenges along the production chain are presented along the process chain of lithium-ion battery cells. The influence of various process-machine interactions on the properties of the electrode is illustrated using the anode of sodium-ion batteries as an example. First conclusions whether the production technology can be adapted to the cell chemistry of the future at an early stage will be made.

Current developments in the electric mobility sector and the need for the storage of energy from renewable sources lead to a growing demand for lithium-ion batteries (LIB). Although they provide high energy densities, the increasing requirements push this technology to its performance limits. Furthermore some of the commonly used electrode raw materials face alarming political, ecological and economic risks. The DFG-funded project POLiS Cluster of Excellence therefore aims to develop sustainable battery materials to produce safer batteries with higher performance properties. In addition to the choice of the material each process step has an impact on future cell performance. High energy densities are obtained by a properly adjusted calendering process. The compression of the electrode material leads among other improvements to an increase of the volumetric energy density. Hence, it is of great importance to understand the process of calendering to achieve satisfying electrochemical cell properties. This work investigates the influence of material characteristics on the calendering process. One promising post-lithium candidate is sodium with its corresponding anode material hard carbon. This study focusses on analysing the correlation between the particle size and morphology of hard carbon and the generated anode properties after calendering. Furthermore the slurry composition and drying conditions are taken into account. Line load, web tension and temperature are varied calendering process parameters. Resulting compaction rates and adhesive forces are presented and scanning electron microscopy images complete the analysis of the material behavior. A stereo camera system quantifies the distortions caused by calendering. Finally conductivity measurements rate the quality of the calendered anode material. These results contribute to building a tool for the prediction of the processability of future battery materials.