Energy-Efficient Clean and Dry Rooms and Mini-Environments

Battery cell production is very energy-intensive. A large proportion of the energy used is required to maintain the atmospheric conditions necessary for the production processes and is therefore used for the infrastructure. A particularly dry production environment and defined cleanliness requirements are prerequisites for high cell performance, especially when processing nickel-rich NMC materials and manufacturing all-solid-state batteries. In addition to controlling contamination and the degradation of active materials, the focus is on protecting employees and enabling uninterrupted production.

With the aim of successfully advancing the energy transition, Fraunhofer ISE is meeting these challenges and developing innovative solutions for the battery cell production of tomorrow. Through extensive expertise and cross-system research, both battery cell production-related and interdisciplinary issues are being researched. The optimization potential of the production infrastructure is considered holistically at Fraunhofer ISE. For example, the optimization of the efficiency of dry rooms and the encapsulation of systems in so-called micro or mini-environments are current research priorities.  

Through the operation of a semi-automatic pouch cell production line in the clean and dry room of the “Center for Electrical Energy Storage” at Fraunhofer ISE and close cooperation with renowned scientific partners, expertise is available with regard to the requirements of manufacturing processes in battery cell production. Extensive cell characterization and battery tests allow the effects of innovative concepts to be examined holistically. There is also many years of experience in the field of ventilation technology and the integration of heat pumps.

Our research focuses on increasing the efficiency of clean and dry rooms:

• Monitoring dew point temperatures and particle emissions along the process chain and evaluating the influences between infrastructure and manufacturing processes, with a focus on battery cell production
• Evaluation of air exchange in dry rooms using innovative measurement technology and simulations
• Integration into building infrastructures and development of energy concepts
• Increasing the efficiency of dehumidification systems through intelligent control, heat integration and modeling of dehumidification systems

The transformation of classic battery cell assembly into encapsulated production lines with locally varying atmospheric conditions requires further research:

• Investigation of various enclosure and ventilation concepts for applications with extremely low dew point temperatures
• Quantification and reduction of infiltrations into the production line as well as control of contamination and occupational safety
• Assessment of required air volumes and evaluation of air exchange
• Integration of system technology, intralogistics interfaces and airlock concepts
• Techno-economic evaluation and comparison of various enclosure concepts