The application of Industry 4.0 in lithium-ion battery cell production enables companies to achieve increased product quality and global competitiveness, since the majority of value creation takes place in this process. Studies have shown, that improving production performance is the most effective way for battery cell manufacturers to become competitive in the increasingly globalized market. To achieve operational excellence, battery manufacturers must adopt the concepts of networked and digitized production. However, holistically introducing digitalization, data systems and Industry 4.0 methods in all sectors of lithium-ion battery cell production currently poses a major challenge as comprehensive approaches are not available. Therefore, a tailored methodology for the evaluation of suitability and introduction of digitalization and Industry 4.0 is presented. The approach addresses all production-related sectors from logistics to plant engineering to quality management via so called application areas. Multiple development stages divide these into the maturity levels in terms of Industry 4.0. To design each application area and stage, Industry 4.0 use cases from battery cell producers, plant manufacturers, and battery-related research projects are clustered and abstracted for general accessibility. It is shown, that abstracted application areas may be assigned either to all production sectors such as communication or to specific fields such as quality methods. Based on the application areas, corresponding toolboxes are established forming the core of a digitalization guide. To increase the level of maturity with regard to Industry 4.0, the presented paper aims at enabling companies to apply appropriate tools from the toolbox to their production. The systematic and efficient development and implementation of digitalization as well as the holistic assessment of a company's maturity are enabled and provide an essential tool towards increased competitiveness.