Progress in battery recycling: "Infinite" durability of lithium-ion batteries in sight

In the wake of the boom in lithium-ion batteries brought about by the mobility revolution, more than 40 new battery factory projects are expected in the next few years, according to the European mobility association Transport and Environment. In view of the increasingly urgent search for efficient and sustainable approaches to energy generation, the question of appropriate recycling solutions for batteries also arises.

While the recycling of lithium-ion batteries could only begin after the discharged batteries had been shredded - this is the only way to get at the incorporated recyclable materials - researchers at the INM in Saarbrücken, the FAU in Erlangen and the Fraunhofer-ISC in Würzburg are working on a more efficient process to completely return the recyclable materials to the raw material cycle. This is the BMBF project "AdRecBat", the additive-based design to recycling lithium-ion batteries. Here, the researchers' efforts are not only directed at the components that are necessary for energy storage, but also at the other parts such as housings, electrodes or encapsulations.

Integrated separating effect

To facilitate the recycling of lithium-ion batteries at the end of their life cycle, the researchers are examining all key connections of the individual components - the changes compared to today's design thus occur on several levels. Points that are relevant for recycling are, for example, the interface between the electrode and the current collector, the sealing seam of the pouch foil and the limiting surface between the active material and the cathode.

In the new design, the researchers work with trigger materials that cause separation reactions when external conditions change in different ways. Such changes can affect the temperature, the pH value or the external magnetic field. For example, if the pH value changes, the separation reaction occurs and the components separate from each other. The challenge regarding the trigger materials - also called trigger additives - is that they should be able to be flexibly incorporated into different types of batteries, also independent of the manufacturer.

The idea behind the process is that of the "immortality" of the individual materials: they should - at least theoretically - be able to be recycled an infinite number of times. To achieve this and to guarantee a certain economy and efficiency in the way the components work, the separation additives must not impair the functionality of the components that surround them in any way. If this succeeds, the chaotic shredding of lithium-ion batteries could soon be a thing of the past.

Source: maschinenmarkt.vogel.de, Peter Königsreuther, 10.01.2023
Image: Institut für Neue Materialien (INM)