Releasing when necessary – from adhesives to circularity

Planned release

Components bonded with conventional adhesives often cannot be separated without causing damage. In the past, this was less of an issue for batteries: At the end of their lifecycle, traction batteries were typically shredded completely so that the active materials they contained could be recovered in the subsequent recycling process. Selective disassembly usually did not take place – as a result, many components and valuable materials were lost. With the ramp-up of electromobility, however, this equation is changing fundamentally. In a vehicle battery, around 70 to 80 percent of the cost lies in the active materials – especially in the high‑quality cathode and anode materials that are responsible for storing and releasing electrical energy. If these materials can be selectively recycled and reused, both costs and raw material dependencies decrease. In production, dismantlability also opens up new potential: If a defective battery pack or module can be reopened, it does not have to be discarded or fully shredded immediately. This helps reduce scrap rates, enables repairs, and keeps valuable materials in circulation.

Henkel focuses on two technical mechanisms. In thermal debonding, heat is applied in a targeted and localized manner so that a special layer at the interface changes its structure or adhesion properties. This creates a defined separation path along which components can be cleanly detached from one another. This principle is used not only in batteries but also in display and other electronics applications, as well as headlights. In electrical debonding, conductive ions are present in the adhesive. When a voltage is applied, these ions migrate to the interface and selectively weaken the bond. Elizaveta describes the process as controlled, clean delamination that does not require significant heating or mechanical removal.

The key point: The bond must never release unintentionally. “There are no unintended triggers,” emphasizes Elizaveta. “Neither road vibrations nor fast charging nor summer heat activate the effect. Debonding is deliberate and tied to clearly defined conditions.” Currently, the technology is at an early stage of technical maturity, but the path forward is clear: From initial concepts to functional demonstrators and on to validation projects in customer environments, important milestones have already been achieved. The focus now is on making the systems industrially scalable and integrating them into real manufacturing and service processes. For customers, this will create significant added value in the future – from reduced scrap rates to more efficient repair processes to improved recovery of valuable materials.

Sustainability that pays off

Dr. Melanie Luckey approaches the topic from another perspective. As Head of Sustainability Automotive Components at Henkel, she shapes the sustainability strategy for this specific business area of the company – one whose adhesives, together with those from Henkel’s automotive OEM business, are installed in an estimated nine out of ten vehicles worldwide.

Melanie knows the practical challenge: Ecological arguments alone are often not enough to convince. “The beauty of debonding is that it not only increases sustainability but also can actually save costs,” she says. A headlamp scratched today often requires replacement of the entire module – including expensive LED technology. With debonding, only the lens might need to be replaced in the future. In batteries, defective units could be repaired instead of replacing the entire pack. And in production, scrap rates fall if defects can be corrected before a component must be discarded.

Yet Melanie is also clear about the limits. Sustainability is not created in the final production step. “Many essential aspects of sustainability performance are defined at the very beginning, in the design phase,” she says. Debonding must be integrated early – long before the vehicle ever reaches the road. That is easier said than done. In Europe, a vehicle design cycle for traditional automakers takes about four to five years. Production lines are built around established processes. Adding a debonding layer means new application steps, new tests, new approvals – and persuasion at every level. “From the outside, it often looks simple to just implement a new design,” Melanie says. “In reality, however, it is a demanding and lengthy process.”

Raw materials that should not be lost

Beyond the economic and environmental arguments, debonding also has a geopolitical dimension. Europe relies entirely on imports for many raw materials. Recycling thus becomes not only a question of sustainability, but also of supply security. “A well-positioned domestic circular economy strengthens our own value creation,” says Elizaveta. The goal is to use existing materials multiple times and thereby make value chains more resilient. Debonding contributes precisely to this: High-value materials can be recovered selectively instead of being lost in the shredder. Sustainability becomes a matter of intelligent resource management – ecologically meaningful and economically sound at the same time.

The moment of clarity

Henkel does not see itself as an adhesive supplier that merely responds to requests, but as a development partner that proactively drives topics forward. At the Battery Engineering Center in Düsseldorf and in other application centers around the world, demonstrators are built, concepts tested, customer requirements are simulated. Elizaveta presents the topic at conferences. Melanie showcases demonstrators in which a battery opens in a controlled manner before the observer’s eyes. “Debonding always produces that moment of sudden clarity,” she says. Even experienced engineers are surprised the first time they see a bonded component separate so cleanly. Sustainability cannot be achieved alone – not technologically and not economically. That is why Henkel works with vehicle manufacturers, suppliers, recyclers, and raw material producers to advance responsible resource use and circularity. Together, they identify and implement scalable solutions on the path to net-zero and a circular value chain. Because debonding must fit into real recycling streams. Workshops must be able to handle it. Recyclers need suitable trigger options. A battery that can be opened in a laboratory but is not accepted by any recycling facility solves nothing. Adhesives must hold. But the future belongs to those who know how to release.