Enabling Holistic Tracking and Tracing in Battery Cell Production: Marking Technologies and Identification

The production of battery cells involves a complex process chain with interconnected steps leading to unknown cause-and-effect relationships and production inaccuracies, contributing to costly scrap due to expensive materials. An integrated traceability system down to the level of single electrode sheets allows the linkage of intermediate products and their measured properties throughout the entire process chain. This approach creates a new database that improves the understanding of interactions within the process chain. For a traceability system, a unique identification of the intermediate products is required. Therefore, this work introduces a four-step methodology for seamlessly integration of relevant components into the battery cell production process to ensure traceability. Laser and ink-based markings are described in detail, and the readability is evaluated depending on the marking parameters. For all methods, the advantages and challenges are outlined. Laser and ink marking systems are suitable options for the unique identification of intermediate products. The markings can be decoded with devices along the process chain, which is an efficient solution. Image-based methods enable marking-free identification of intermediate products but require a significantly more complex hardware technology in each process step for a comprehensive traceability system.