A central focus of research for the working group is the development and optimization of recipes and manufacturing processes for electrode foils at the pilot scale. From a technological point of view, lithium-ion batteries and high-performance capacitors for mobile applications are of particular interest. Commercially available active materials, binders and additives, as well as IKTS-owned active materials (e. g. LiNi0.5Mn1.5O4) are processed so as to obtain electrode slurries and pastes, and applied onto current collector foils for research purposes. This allows, for instance, to apply ceramic functional layers onto existing LFP electrodes in another tape-casting step, which in turn allows to replace the component of the separator.
Beside the recipe, the structure and morphology of the electrodes have a significant effect on the cell’s properties and performance parameters. In order to systematically optimize the electrode design, IKTS uses empirical, knowledge-based approaches as well as model-based methods, developed at Technische Universität Dresden and validated for IKTS electrode development in joint research projects. Especially when it comes to producing electrodes with a high storage capacity load, it is possible to use simulation and optimization efforts to accurately identify the electrode’s specific design parameters (porosity, coat thickness, particle distribution). It allows to attain the best possible current load rating.
In general, the long-term stability and performance of the electrodes can be improved significantly by selecting the right process parameters, resulting in advantages in terms of efficiency and quality. Among other things, typical developments focus on:
- Reproducible slurries and paste production at pilot scale up to 10 kg
- Prevention of gas cavities and agglomerates
- Substitution of organic solvents by watery solvents for improved environmental compatibility of the manufacturing process
- Optimal electrode adhesion and binder distribution after drying
- High coating speeds through roll-to-roll (R2R) processes
- Uniform surface quality (without cavities, agglomerates, creases)
- Minimized variations in layer thickness for large-format cells
- Uniform, continuous compression in the calender
Building on its experience with ceramic tapes, the working group uses extensive know-how from slurry production and pre-industrial casting and extrusion processes. This specific know-how is available for clients who intend to bring new materials from pre-development into serial production and want to identify or validate the technological process parameters beforehand in the Battery Technology Application Center, in manufacturing conditions similar to those prevalent in industrial production.
- Model-based electrode development and optimization according to client’s specification
- Manufacture of electrode slurries and pastes at pre-industrial scale
- Development and optimization of innovative manufacturing concepts for electrode production
- Implementation of material or coating trials on electrode foil using the classic tape-casting process or hot or cold plastic tape extrusion in dry-room conditions
- Upscaling of manufacturing processes and technology transfer to the client
- Feasibility studies and consulting in the field of process development