Battery Technology Application Center

Topic

© Fraunhofer IKTS
Process flow of a lithium-ion battery production.
© Fraunhofer IKTS
Intensive mixer for homogeneous dispersion of battery slurries.
© Fraunhofer IKTS
IR drying of electrode foils.

Continuously reducing manufacturing costs is essential for expanding further the use of lithium-ion batteries for mobile or stationary energy storage in the future. Technology development and scaling are decisive links between the basic research in the lab and industrial process development in serial production. For several years we have been operating an application center for this purpose, which has been continuously expanded.

At the Battery Technology Application Center, industrial clients find various technological facilities for mixing, slurry preparation, foil coating, drying and compaction of electrode foils, which allow to transfer continuous production processes from the lab to the pre-industrial pilot scale.

With the versatile mixing units (e.g. planetary mixers 2 l and 10 l, intensive mixers, kneaders, single- and twin-screw extruders), customers have access to a wide range of equipment and process parameters for inert wet and dry mixing routes under different viscosities and temperature ranges. Furthermore, film widths of up to 300 mm can be coated on the pilot coater using the classic tape casting process or slot dies. These processes are also used, for instance, if additional functional layers such as ceramic separator layers or polymer electrolytes are applied onto the electrode as a second coat, or when the current collector foil is to be coated on both sides. Furthermore, high-energy electrodes with high surface capacity loading can be produced via flat sheet extrusion using smoothing calenders. Thanks to their high solids content of up to 90 wt % and therefore low solvent contents, continuous extrusion processes for combined mixing and forming for electrode foils have great potential and can reduce manufacturing costs in battery production.

In the Battery Technology Application Center, commercial and prototype inline testing methods are used to research and optimize manufacturing processes. In the process, the pilot plant facilities and their measurement technology are being expanded so that fluctuations and defects in slurries and coatings can be detected and classified at an early stage. With the help of this special testing technology, the quality of slurry and foil production can be continuously improved and new material systems effectively scaled up.

 

Technical equipment

 

  • Drying chamber with adjustable dew point temperature down to -70 °C
  • Intensive mixer for dry mixing and dispersing up to 10 kg
  • Tempered planetary mixer for dispersing up to 10 kg
  • Measuring kneader for formulation development for highly viscous compounds
  • Single and twin-screw extruder for continuous paste feeding and mixing
  • Drum preparation on a roller mill
  • Roll-to-roll coater with 10 m drying line (IR and HotPlate), application tools doctor blade (up to 300 mm) and slot die (up to 260 mm)
  • Processing of organic solvents incl. recovery system in all plants
  • Extrusion line for cold and hot plastic electrode compounds incl. smoothing unit and drying line for high-capacity electrode compounds
  • Inline ultrasonic grammage measurement, thickness measurement and optical defect detection
  • Residual moisture analysis in drying chamber (Karl Fischer titration)
  • Heatable compacting calender with IR emitter
© Fraunhofer IKTS
Electrode coating with doctor blade on roll.
© Fraunhofer IKTS
Electrode production using slot die coating.
© Fraunhofer IKTS
Inline measurement technology for determining the coating thickness and grammage of electrode foils.