Integration of an Electrode-Sheet-Based Traceability System into the Manufacturing Process of Lithium-Ion Battery Cells

The production of lithium-ion batteries consists of a long and complex process chain. The individual process steps influence each other, resulting in unknown cause-and-effect interactions. As a result, production fluctuations cause variations in the final battery cell properties, which, coupled with high material costs, lead to costly scrap. Sensor and machine data provide important information during production about the manufacturing and condition of intermediate products. However, a challenge exists, in that these valuable production data cannot be precisely assigned to the corresponding intermediate products, and consequently, the cause of the production fluctuation cannot be explained. In this article, a method for tracking and tracing single-electrode sections from coating to formation is described. Using the example of areal mass loading, it shows that all production data for the electrode production can be assigned automatically to the individual electrode sheets. In addition, all production data for cell assembly and cell finalization can be assigned to each cell stack and thus to the electrodes used. The monitored electrode areal mass loading of individual electrode sheets enables the identification of deviating electrode sections and a cell-specific calculation of the final capacity from manufactured battery cells.