To produce battery cells ever more cheaply, the production processes must be optimised continuously. With a throughput of 0.6 to 0.7 GWh/a per electrolyte filling system, the process is a bottleneck in cell assembly and must be highly parallelized to keep up with the throughput of a gigafactory. Additionally, electrolyte filling is decisive for the quality and safety of the cell, as complete wetting of the cell must be guaranteed to maximize performance and prevent formation of high
surface area Li deposits due to local current differences. Considering the current trend of producing larger battery cells formats, especially in the automotive sector, the bottleneck in production capacity represented by electrolyte filling becomes even more critical due to the increase in wetting time. Consequently, there is substantial potential for identifying process optimizations in the electrolyte filling process to save costs and resources. However, there is a gap in the research on industrial applications and large cell formats in the electrolyte filling literature. Nevertheless, understanding the electrolyte filling process for industrially applicable cell formats including scaling effects is indispensable for process optimization and deriving recommendations for future process development.
Therefore, in this study, we analyze and evaluate novel technologies for electrolyte filling, identifying several technologies with significant potential to contribute to an optimization of the process. To this end, a systematic literature and patent search was conducted, the results were filtered, and then evaluated by a group of experts on the basis of various criteria. Several promising technology approaches for optimizing the process in industrial environment in terms of speed, flexibility, safety, and quality were identified. Based on the criteria, the technologies were discussed and evaluated, and classified according to their technological maturity and suitable cell designs. Thereby, some eminently promising technologies were identified and recommendations for industry and science were derived.