Design of a Material Flow Method and Technology Procedure for Battery Cell Production in Mini-Environments

Due to the rising interest in electric vehicles, the demand for more efficient battery cells is increasing rapidly and immense production capacity expansions are announced in the next decade. Manufacturing of lithium ion battery cells is complex and highly influenced by the environmental product conditions. Nearly along the hole value chain, the production processes take place in so-called clean and dry rooms to strictly control humidity and particular contamination. Cleanliness can be ensured with appropriate air management systems, while dry air handling is technically and energetically much more complex. To counteract this, the mini-environment approach reduces the amount of air, as the system is enclosed airtight in a process- and product-oriented manner. Mini-environments offer the possibility of replacing conventional clean and dry rooms through energy and cost savings, improved product quality and increased operator safety. However, to rollout the mini-environment approach in battery cell production facilities, production methods and technologies must be developed and researched. Next to the machine level, especially the material flow level must be addressed and is key for the holistic integration of the mini-environment approach in production facilities. Moreover, due to cross-machine movements while maintaining constant and stable atmosphere conditions, there are currently no logistics or airlock solutions tailored for battery cell production. This paper provides a method named MiniMaFlow including systematically developed solutions to enable modular and rigid material flow in mini-environments. The method is conducted to fulfill the cleanliness and humidity requirements with focus on innovation, costs, and sustainability. A first modular prototype has been designed to achieve detailed level for production research. With this, a holistic analysis and evaluation is conducted compared to the state of the art. In conclusion, a validated transferable potential heat-map and a use-case-specific quantitative evaluation for technology-implementation are shown as a result.