Identification of Cause–Effect Relationships between Process Parameters and the Film Formation in the Semidry Electrode Production for Lithium-Ion Batteries

Abstract

Conventional electrode production for lithium-ion batteries has high energy and plant space demand, due to the high solvent content of the slurry to be processed by slot die or doctor blade coating. By using the semidry electrode production, the solvent content is reduced by more than 50% compared to the conventional electrode production, decreasing energy demand and drying length. Regarding technology readiness level, the semidry electrode production is on the pilot scale, as the basic principles have been shown. However, many unknown cause–effect correlations exist between the process parameters and the product properties. This study aims to analyze process parameter variations and their influence on the geometric, electrochemical, and mechanical properties of the electrode. An experimental design is utilized to obtain statistically relevant conclusions. It is found that the first calender gap and the roller speed influence the mass loading and the porosity of the electrode. The roller speed significantly influences the ionic resistance within the electrode, which may be attributed to the used release foil.