Battery recycling starts with material design

How Material Selection, Design, and the Battery Passport Shape the Circular Economy

November 10, 2026

Batteries are often considered a key technology for the energy transition. But their sustainability also depends on the materials they contain and whether those materials can be returned to the cycle after use.

Three questions for Dr. Kathrin Baumgartner, TechHUB Battery:

1. Batteries are often described in terms of their cell chemistry. Beyond that, what role do metals and plastics play?

Batteries are complex material systems. Cell chemistry is important, but it represents only one part of this material system. In a lithium-ion cell, the active materials of the electrodes are deposited onto metallic current collectors: typically aluminum on the cathode side and copper on the anode side. Other components include the separator, electrolyte, binder, and cell housing. Numerous additional metallic and polymer components are also used at the module and pack levels.

Polymers are not merely auxiliary materials here: as binders, they hold the particles within the electrode layer together and ensure their adhesion to the current collector. As separators, they prevent direct electrical contact between the electrodes while simultaneously allowing the transport of ions.

For development, this means that the materials used must not only enable the desired performance and safety. Their interfaces, connections, and processing methods also influence how complex it will be to later disassemble cells and battery systems and recover their components.

2. What makes battery recycling challenging, and where does recycling-friendly design come into play?

A battery is a tightly integrated assembly of materials and components.

Cell chemistry, cell format, and module and pack design all influence which processing methods are appropriate and which materials can be recovered—and to what quality. Adhesives and bonds that are difficult to break can complicate disassembly. In electrode processing, it is also crucial to separate active materials as cleanly as possible from the metallic current collectors and other cell components.

Therefore, “recycling-friendly design” does not simply mean using as few materials as possible. It is also crucial whether materials and components can be identified, separated, and processed with reasonable effort. If different materials are bonded together in a way that makes them difficult to separate, or if components can only be disassembled with great effort, recovery becomes more complicated.

Equally important is reliable information about which materials and cell chemistries are used in a battery. This enables stakeholders along the value chain—from manufacturing through use and disassembly to recycling—to collaborate more effectively. Material combinations, joining techniques, disassembly methods, and the availability of relevant product information should therefore be taken into account as early as the development stage.

3. What is needed to turn recycling into a functioning material cycle?

What matters is not just how much battery waste is processed, but which materials are recovered and in what quality.

The EU Battery Regulation therefore distinguishes between recycling efficiency and the recovery of individual materials. For lithium-based used batteries, a recycling efficiency of 65 percent—based on the average weight of the used batteries received—will apply starting at the end of 2025. However, this metric does not automatically indicate how much lithium, nickel, cobalt, or copper is recovered.

To achieve a closed-loop system, collection, pretreatment, and material-selective processing must work together. Approaches such as the direct regeneration of active materials aim to preserve their material structure but require the cleanest possible separation of cell components.

At the same time, traceability and digital material information are becoming more important, for example through the battery passport. Starting February 18, 2027, a digital battery passport will be mandatory for electric vehicle batteries, batteries for light-duty vehicles, and industrial batteries exceeding 2 kWh. It establishes a regulatory framework for battery-related information throughout the life cycle and makes data on materials and their origin a key issue for the value chain.

Thinking Ahead Together on Batteries

The Bavarian Battery Congress will once again bring together stakeholders from industry, research, and politics in 2027 to advance innovation and collaboration across the entire battery value chain. Details about the event will follow shortly.

AI-edited