Dürr and GROB concept battery factory uses 50% less production space

Engineering companies Dürr and GROB have developed a concept factory for lithium-ion battery cells which needs less space and energy than existing plants, while delivering higher performance and quality.

This technology was introduced to the industry by the two partners at “The Battery Show Europe 2025” trade fair held in Stuttgart, Germany. Technologies at their expo stand included the dry coating of electrodes without needing a drying process, and a powerful Z-folder system for cell assembly with integrated notching.

Automotive Industries (AI) asked Bernhard Bruhn, Vice President Global Business Unit Lithium-Ion Battery at Dürr, what motivated Dürr and GROB to partner in the development of a new concept factory for lithium-ion battery cells.

Bruhn: It is about market presence, capabilities, and coverage of a major part of the value chain in the battery factory.

At the beginning of the growth phase for lithium-ion batteries in 2022/23, it became clear that this represented opportunities for German machinery manufacturers, especially those with the depth and size of Dürr, and which have the ability to build and equip big factories, but there was little broader market recognition of our capabilities.

Dürr and GROB have been cooperating in the field of production technology for lithium-ion batteries since 2022. The partnership is built on achieving market recognition that we have the corporate power, the capabilities, and the competence to develop the factories.

Our joint capabilities were showcased for the first time at the Battery Show 2024. The aim is to jointly establish ourselves as system suppliers of battery production equipment in Europe and North America. With o

ur expanded portfolio of machines and systems, together we cover almost the entire value chain for battery cell production with our own technologies.

AI: What key technologies did you present at the Battery Show in 2025?

Bruhn: In addition to a classic production layout with wet coating, we have developed a concept factory with dry coating, which is close to commercialization on pilot scale. For our customers, this means significantly better space efficiency and lower operating costs.

AI: How does the dry coating process work?

Bruhn: Instead of conventional slurry, the process uses a dry-mixed active material. This powder mixture is pressed into a free-standing film using calender machines, and then laminated onto both sides of the collector foil.

Compared to wet coating, this eliminates the drying process as well as the recovery and treatment of solvents – saving space, energy, and costs.

The free-standing film also offers advantages in terms of material efficiency, as excess film material can be completely recycled into the production process before lamination onto the collector foil. After calendering, the coat weight can be measured directly, enabling better control of the coating thickness.

The subsequent lamination onto the collector foil requires less force than calendering in the wet coating process, which means that the foil does not deform – improving its processability for downstream notching and stacking.

AI: What new process have you developed for battery electrolyte filling?

Bruhn: A process developed by Dürr enables battery cells to be filled in a single step without residual gas. Unlike the conventional process, the electrolyte is filled directly into the cells at up to 30 bar.

The filling pressure is thus two to three times higher than the current industry standard. The process design enables precise dosing and shortens both the filling process and the subsequent penetration of the electrolyte into the active material.

AI: Are you using digital mapping of the production process?

Bruhn: Our equipment technology is complemented by end-to-end digital mapping of the production process. In the planning phase before production starts, a digital twin enables simulation of the entire factory and speeds up implementation on site.

The data from the simulation flows into the MES/MOM software of our subsidiary iTAC and is used to plan and control all production steps in battery manufacturing. Important functions here are traceability and quality analysis to avoid errors in production. This results in high overall equipment effectiveness.

AI: Has Dürr further optimized its technologies in the classic wet coating process and in what way?

Bruhn: Dürr has further optimized its technologies in the simultaneous dual-side wet coating process in terms of perform

ance and energy efficiency. One example is the automation of the coating station and the slot dies, which form a closed control loop for the layer thickness – resulting in faster production start-up and reduced scrap rate.

In the subsequent drying process, battery manufacturers can use laser dryers to achieve a 50% faster web speed and particularly energy-efficient drying. After drying, we use our own calender technology for densification of the electrode coating.

The machines from our subsidiary Ingecal work with particular precision using “Dynamic Gap Control”:  the distance between the two rollers is controlled with an accuracy of 0.5 µm. This results in a very uniform layer thickness, with no more force being applied than necessary. Dürr Ingecal’s calenders are used for both wet coating and dry coating to compress the film.

AI: What is next for Dürr?

Bruhn: The focus is on the further development of dry coating, commercialization and ramp-up. To foster a strong market presence, we are bringing together our products for electrode coating and electrolyte filling under the new name “X.Cellify.” We continue to develop our relationships with technical partners and customers, realizing mutually beneficial relationships.