关键词: 狭缝涂布, 表面化学, 流变学, 制造工艺, 智能制造

Abstract:

As a key process in manufacturing lithium-ion batteries, coating compliance with process specifications plays a crucial role in the capacity consistency and safety of batteries and involves complex mechanisms such as surface chemistry and rheology theory. Lithium-ion battery manufacturers and coating equipment suppliers are pursuing automated and intelligent coating operation methods, whereas current research on coating is often limited to surface chemistry and other microscopic problems. Based on comprehensive literature research and simulation analysis, four evolution processes of mass-density flow field and film morphology of slurry, namely during slot die coating, mold expansion, wetting film formation, and drying shrinkage, are proposed for the first time. The influence of six key processes and quality indices, namely the consistency of the transverse opposite density, consistency of longitudinal areal density, edge thickness, film width, missing coating defects, and peel strength after calendaring, are summarized in the process of coating evolution. Through the analysis of these active variables and uncontrollable factors affecting the coating process, we can better understand the possible problems and reasons related to these problems in the coating process. Finally, a closed-loop control strategy combining intelligence and manual intervention was devised to manage the six coating quality indices. This strategy provides theoretical guidance and an algorithmic framework for improving intelligent coating and unmanned production. Additionally, this strategy is of great significance for improving the quality and production efficiency of lithium-ion battery coatings.

Key words: slot die coating, surface chemistry, rheology, manufacturing process, intelligent manufacturing