Recycling lithium-ion batteries from electric cars and completing the material cycle of valuable raw materials is made possible by combining two different recycling processes.

The first step in the process is for the car batteries to be deep-discharged at Duesenfeld GmbH in Wendeburg (Lower Saxony). Following this, they are dismantled and shredded. In the next step, the granulate is transferred to a vacuum dryer. At this stage, the lithium is on the cathode. But the liquid electrolyte, which is spread over the shredded material, also contains lithium. There is negative pressure and a temperature of 80 °C in the vacuum dryer. The electrolyte evaporates and a lithium salt is created on the granulate. This granulate is now separated into different fractions. The valuable substances cobalt, nickel, manganese and also the lithium are now in a powdery black fraction, the so-called black mass.

This black mass can be further treated with the help of the so-called COOL process. The process was developed at the TU Bergakademie Freiberg. A pilot plant for this process has been installed at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Freiberg (Saxony), with the help of which 95 % of the lithium contained can be recovered from the Black Mass. For this purpose, water and CO2 are added to the Black Mass. A supercritical state is created - with a liquid and a solid fraction. The lithium is in the liquid phase. It is filtered, first concentrated and then heated. White battery-quality lithium carbonate is formed. This lithium carbonate can be reused for battery production. The cycle is completed.

12:11 min: In the film, the expert states the required degree of purity of lithium carbonate for battery quality with a value of 99.8 %. Only 99.5 % is required for battery quality. The process presented achieves 99.8 %. This means that the quality requirements are met.

The system for carrying out the COOL process at Fraunhofer IKTS in Freiberg was purchased as part of a grant from the Saxon State Ministry for Science, Culture and Tourism for the SaxBattEmPower project (part of the SaxBatt project).
The system is operated within the framework of the EarLiMet project, which is funded by the German Federal Ministry of Education and Research (BMBF).

Further information on Duesenfeld GmbH: https://www.duesenfeld.com/
Further information on the Fraunhofer Institute for Ceramic Technologies and Systems IKTS: https://www.ikts.fraunhofer.de
Further information on the BMBF-Competence Cluster Recycling & Green Battery (greenBatt): https://www.greenbatt-cluster.de/en/

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On behalf of the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection