ReAktiv – Highly Efficient Recycling of Li-Ion Active Materials from Round and Button Cells

The "ReAktiv" project addresses a significant improvement in the recycling process for round cells and the processing of the active materials recovered from them without producing black mass. In addition, the recycling of the active materials into new battery cells is to be demonstrated. On the other hand, a process based on the black mass from button cells is currently undergoing revision and optimization, aiming to enable the recovery of the contained lithium metal as well. Round cells, which mainly come from production waste, are first dismantled and the anodes and cathodes they contain are separated by type. Once the active materials have been removed from the electrode foils, they are cleaned and, if necessary, processed in further steps. The properties of this recycled material should be comparable to virgin material, which will be demonstrated by the construction of new cells with a recycled content and their subsequent characterization. At the same time, the knowledge gained will be transferred to a battery cell model with the help of a hybrid model, so that at the end of the project a model for recycled cells will be available as a design aid. Fraunhofer ISE is preparing an economic and ecological assessment of the new process chain.

The ReAktiv project aims to significantly increase the efficiency of recycling processes for round and button cells as well as the recyclability of the recovered active materials. Along the battery recycling process chain, a total of three process steps are to be explicitly further developed and implemented in demonstrators up to a Technology Readiness Level (TRL) 7 as part of the project. Firstly, a new process for dismantling round cells is to be developed with the help of which battery cells can be opened automatically and broken down into their cell components in a defined manner. In contrast to the mechanical shredding processes used today (e.g., shredding), this is intended to avoid premature mixing of the material fractions. The product of the dismantling process to be developed is electrode foils that have been dismantled and largely freed of organic components (electrolyte and binder), separated into anode and cathode.

The second new development in the project involves the mechanical separation of the anode and cathode materials from the corresponding electrode foils and their downstream hydro-mechanical processing. For the development of this direct recycling process, various mechanical separation processes are to be investigated and evaluated regarding their efficiency and scalability. The anode and cathode materials recovered in this way are to be processed downstream with the best possible preservation of structure and with the greatest possible restoration of electrochemical properties for reuse in the production of Li-ion cells via admixture in anode and cathode slurry.

The third new development involves the further development of existing hydrometallurgical processes with the aim of increasing the recycling efficiency in the recovery of lithium to over 90 %. This increase in efficiency is to be achieved by selective lithium leaching and increasing the activity of the black mass at the start of the process, which also significantly reduces the acid requirement for the subsequent leaching steps for other valuable metals.

The further development of the three process steps is always accompanied and evaluated by the corresponding material and economic life cycle analysis. Fraunhofer ISE carries out the corresponding assessments and supports the partners in their decisions. The associated project partner Varta provides the other partners with the samples of round cells and material from the production scrap, or the end-of-life (EoL) round and button cells required for the project work. Proof of the usability of the recovered active materials in new battery cells is to be provided by setting up corresponding test and full cells on a laboratory scale. The knowledge gained here will be continuously fed back into the development of the various processes. The results of the project will be used to demonstrate for the first time the technical and economic feasibility of round cell disassembly and the recyclability of the active material fractions directly recovered in this way. To this end, scientific findings will be implemented in prototypes together with the industrial partners. The results offer potential applications for the recycling and processing of end-of-line production waste at cell manufacturers as well as for EoL round and button cells at recyclers.