Drying process

© Photo Fraunhofer IPA

 

A key process step in electrode manufacture is drying the active material layer completely before it is compacted in the subsequent calendering process. In addition to the coating process, the drying process can also alter the surface characteristics of electrodes significantly.

In general, convection dryers and IR dryers combined with hot air units are used in battery manufacture. The heat output (heater temperature), as well as the temperature and flow velocity of the hot air, needs to be adapted to the specific requirements of the combination of active material and substrate. This is essential for a fast drying process that is gentle on materials.

These optimum drying conditions and their impact on cell performance can be evaluated in the laboratory. The drying line in the roll-to-roll pilot plant has a range of adjustable parameters. This allows optimum process parameters to be determined for transfer to an industrial scale. Furthermore, by flexibly adapting drying conditions to the requirements of specific electrode systems, the energy efficiency of this cost-intensive process step is also optimized.