Battery recycling Researchers make lithium-ion battery virtually "immortal"

Scientists from the INM in Saarbrücken, the Fraunhofer ISC in Würzburg, and the FAU in Erlangen are soon to start a project aimed at ensuring the reusability of batteries by design.

The world is experiencing a gigantic boom in lithium-ion battery technology due to the mobility transition, among other factors, say researchers involved in the project. Therefore, according to the European mobility association "Transport and Environment," over 40 battery factory projects are announced in Europe for the next ten years. In the interest of the sustainability of electromobility, research into efficient recycling of battery materials and their nearly complete reintegration into the raw material cycle must be advanced as quickly as possible. This involves not only the components responsible for energy storage but also the required electrodes, encapsulations, and casings.

In the BMBF project Adrecbat – Additive-based "Design for Recycling" of lithium-ion batteries, research teams from the Leibniz Institute for New Materials INM, the Fraunhofer Institute for Silicate Research ISC and the Friedrich-Alexander University Erlangen-Nuremberg (FAU) are now pooling their expertise. They aim to design lithium-ion batteries on multiple levels in such a way that the materials used can be easily separated at the end of the battery's life, making them easier to recycle. To this end, the partners are examining all key points relevant to the efficient recycling of lithium-ion batteries.

Built-in separation effect instead of chaotic shredding

Recycling-relevant points include the seal seam of the so-called pouch film, the interface between the current collector and the electrode, and the interface between the active material and the cathode, as the researchers explain. Once the battery reaches its end of life, depending on the properties of the used trigger materials, separation reactions would be specifically triggered by changes in the external magnetic field, temperature, or pH value.

Afterward, essentially only individual components remain, which can then be more easily reintegrated into the manufacturing cycle, as further explained. The trigger additives are intended to be flexible and, if possible, independent of the battery type, so that different manufacturers of lithium-ion batteries can equip their energy cells with the additives while simultaneously improving their recyclability.

The precondition for the success of the procedure is that the additives remain virtually invisible within the battery and do not affect its functionality in any way. Therefore, the set goal is to create a recycling alternative that is more efficient and thus more economical compared to existing pyro- and hydrometallurgical recycling methods. Because with usual methods, the discarded batteries are simply shredded in their entirety without any intermediate steps. The researchers say that the raw materials for lithium-ion batteries can thus be kept in a closed loop, which, in a way, makes the battery type "immortal".