A Review of Process Innovations in the Cell Finishing of Lithium-Ion Batteries in Large-Scale Production

The European Union's ambitious climate targets will make climate-friendly storage technologies essential. More than any other, this decade could be marked by battery technology, especially the lithium-ion battery (LIB). In addition, various trends in mobility and consumer electronics are spurring the cross-industry use of this secondary storage device. As a result, the need for additional production capacities is rising, and the need for vertical integration of the value chain of LIB in Europe. In current forecasts, Europe has a considerable deficit between battery cell demand and production capacities. The deficit highlights the need for additional capacities and effort to develop new production systems. Furthermore, production technologies remain challenging, as high reject rates are expected initially, and a reduction of costs at the battery cell level is mandatory. Formation and aging as part of the cell finishing are the production steps with the highest processing time and space requirements. The formation can take up to 24 hours, and the subsequent aging between 8 to 36 days. It thus represents the biggest bottleneck. In large-scale production, various process innovations are being worked on, depending on the degree of automation. However, a systematic study of the impact of these process innovations is hardly ever carried out. Various approaches are conceivable here: Innovative formation protocols, optimized plant technology, flexible goods carrier systems and other process-related innovations. This paper provides researchers and industry experts with meaningful insights into the status quo and future developments in the cell finishing of battery cells through a comprehensive research approach. These trends will be presented and systematically evaluated to identify the most significant levers to reduce costs and time. It reviews process innovations in cell finishing to approach this research gap and aims to answer how these innovations will benefit and shape the large-scale production of lithium-ion battery cells.