Development of a novel slot nozzle concept for the optimization of a metal foil coater for accumulator development

By adjusting the slot nozzle application, active particles for lithium-ion battery films are to be applied in a certain orientation in the active layer.

The required slot nozzle is intended to apply suitable for this application anisotropic active particles, which have a certain side-length ratio, over the wet application in a certain manner so that they then have a required orientation in the dried active layer.

In the end, the active particles should be oriented towards the arrester foil in terms of quality and quantity to the extent that the diffusion paths of the battery electrolyte are significantly shortened and thus the electrochemical properties of the electrode foils are improved.

The desired orientation should only take place via the application without an upstream treatment of the active particles and without the aid of a further complex process step after the application process.

If it becomes apparent during the course of the project that the entire suspension of the nozzle or even the classic slot nozzle application concept has to be changed, so that additional design changes have to be made to the entire application, then this is permissible.

Furthermore, additional, simple devices and measures that only affect the nozzle or the application itself up to the dryer, which are helpful for a desired particle orientation, are also permissible.

The slot nozzle must be suitable for solventborne and aqueous paste systems with abrasive metal oxide particles and be able to coat them.

In summary, this also means that in addition to its main attribute of being able to orient certain particles in a certain way, this slot nozzle must also cover a certain required application, rheology and paste flow range well in terms of material, solvent, application quality and cross homogeneity.

The dimensions of the nozzle must be in the dimensions so that they can still be well installed and used in the existing coater. The usual total nozzle width is roughly specified with 350-400mm, the total depth with 150-200mm and the total height with 150-200mm.

The nozzle upper part and lower part should be temperable with water up to 80 ° C in order to keep further influence possibilities and parameters on a particle orientation open, since the pastes become less viscous at higher temperatures. For this purpose, connections must be provided on the right side of the nozzle seen in the direction of application, which the ZSW then equips with suitable hose couplings so that an existing temperature control can be connected.

Since plastic dissolving solvents are also used, e.g. NMP (N-methyl-2-pyrrolidone), all seals and soft parts that come into contact with the paste must be solvent-resistant and preferably perfluorinated (PFTE or FFKM).

The slot nozzle material and its surfaces must also be able to withstand the requirements of the solvents and very abrasive particles used.

The nozzle should be easy to disassemble and clean and reassemble reproducibly without much effort. It must be possible to insert so-called shim templates in the nozzle, which vary the application width and the slot width.

Further documented and not mentioned functions must be implemented in accordance with the specifications and development progress.

A confidentiality agreement must be signed in the event of a successful bid.

Services required:

• Discussion of previous and new test results between ZSW and AN

• Creation of manufacturing drawings/3D models or other representations for a further developed slot nozzle, or steps leading to further development, such as the adaptation and repetition of coating tests and their conditions

• Coordination of drafts/concepts for a further developed slot nozzle with the investigators at ZSW before elaboration and production

• If necessary, updating of production drawings/representations after meetings

• Production and delivery of the slot nozzles (lot 2) after multiple optimizations and approval by ZSW for further coating tests

• All steps are carried out in partnership and are intended to document an improvement in battery properties by optimizing the slot nozzle

• Several different development approaches are also conceivable, which are pursued in parallel in order to prove the optimization with experiments

• The development work will be offered and remunerated for the individual development phases on the basis of a framework agreement valid until 31.08.2024

• There is the possibility of extending the framework agreement

The development of a novel slot nozzle concept described in Lot 1 for the optimization of a metal foil coater for accumulator development is to be implemented by a suitable manufacturer in Lot 2. Applications are expected from manufacturers who cooperate in close cooperation with the developers.