Dürr and Grob Unveil Innovative Concept Factory for Lithium-Ion Battery Cell Production

Dürr and Grob Present Concept Factory for Battery Cell Production
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By Zahra Awan, June 12, 2025

Dürr and Grob have unveiled a concept factory dedicated to the production of lithium-ion battery cells. These companies have been collaborating in the realm of production technology for lithium-ion batteries since 2022. German Wankmiller, CEO of the Grob Group, stated, “With our expanded portfolio of highly available machines and systems, we jointly cover almost the entire value chain for battery cell production with our own technologies.”

The partners have developed a concept factory featuring both a traditional production layout with wet coating and an innovative dry coating process utilizing the latest Z-folder technology. Dr. Jochen Weyrauch, CEO of Dürr, emphasized, “Our concept factory, particularly the dry coating process, represents the next generation of battery cell production. Thanks to powerful and innovative technologies, production requires 50% less space and energy. For our customers, this translates to significantly higher space efficiency and lower operating costs.”

### Dry Coating Process

The activated dry electrode process employs a dry-mixed active material. This powder mixture is pressed into a free-standing film using calender machines, which is then laminated onto both sides of the collector foil. By eliminating the drying process and the need for solvent recovery and treatment, dry coating saves space, energy, and costs. Calendering allows for direct measurement of coat weight, enabling better control over coating thickness. The lamination process requires less force than in wet coating, preventing foil deformation and enhancing processability for subsequent notching and stacking.

### High-Speed Cell Assembly

With its latest generation of Z-folders that integrates notching, Grob aims to optimize performance while minimizing space requirements. The separator is guided over deflection rollers with consistent and low web tension. Utilizing a magazine buffer system for the electrodes, the setup reportedly achieves 95% availability.

### Advanced Electrolyte Filling

Traditionally, electrolyte filling occurs directly into the cells at pressures up to 30 bar. However, Dürr has reached a filling pressure that is two to three times higher than the current industry standard, allowing battery cells to be filled in a single step without residual gas. This advancement enables precise dosing and expedites both the filling process and the subsequent penetration of the electrolyte into the active material.

### End-to-End Digitalization

The equipment is further enhanced by comprehensive digital mapping of the production process. A digital twin facilitates the simulation of the entire factory, with data from the simulation integrated into the Manufacturing Execution System (MES) and Manufacturing Operations Management (MOM) software from Dürr’s subsidiary, iTAC. This system enables control and planning of all production steps in battery manufacturing, emphasizing traceability and quality analysis to prevent errors in production. Ultimately, this results in high overall equipment effectiveness.

### Innovations in Wet Coating

Dürr has also improved the performance and energy efficiency of its wet coating technologies. Enhancements include automation at the coating station and slot dies that operate within a closed control loop to manage layer thickness, thereby reducing scrap and allowing for faster production ramp-up. In the drying phase, laser dryers support web speeds that are up to 50% faster and promote energy-efficient drying. For densifying the electrode coating, Dürr’s subsidiary, Ingecal, offers calendering machines equipped with dynamic gap control, utilizing two sensors to measure roller distance with 0.5µm precision. This ensures consistent layer thickness with minimal force applied, making these calenders suitable for both wet and dry coating processes.

In related news, RML Group has received conformity of production (CoP) certification for its battery systems.