Cost-efficient battery cell manufacturing is a topic of intense discussion in both industry and academia, as battery costs are crucial for the market success of electrical vehicles (EVs). Based on forecasted EV growth rates, battery cell manufacturers are investing billions of dollars in new battery cell plants. Whether these billion-dollar investments are economically viable depends on the materialization of forecasted EV growth rates and company-specific competitive market positions. For both, cost-efficient battery cell manufacturing is key for success. To ensure cost-efficient battery cell manufacturing, transparency is necessary regarding overall manufacturing costs, their cost drivers, and the monetary value of potential cost reductions. Driven by these requirements, a cost model for a large-scale battery cell factory is developed. The model relies on the process-based cost modelling technique (PBCM) and includes more than 250 parameters. Based on this cost model, directions are provided, how minimum costs can be achieved reflecting current and future state of technology. Further, it is outlined which process steps and cost elements have the greatest impact on total cost and should thus be focused within future cost reduction activities.