Automatic film production is the core front-end process of lithium-ion battery electrode sheet manufacturing, which refers to the process of coating the slurry on metal foil material through a series of automated equipment, and then drying, rolling, cutting and other steps to produce positive and negative electrode sheets that meet the specifications. Its core goal is to achieve high consistency, high precision, and high quality of the polarizer, laying the foundation for the performance of the battery cell.

The standard workflow mainly includes the following steps:

Slurry preparation and transportation: Active substances, conductive agents, binders, etc. are made into a uniform slurry in a vacuum mixer according to specific formulas, and then automatically transported to the material box of the coating machine through pipelines, and continuously stirred to prevent settling.

Continuous coating and drying: The metal foil material (positive electrode aluminum foil/negative electrode copper foil) is led out by a unwinding device, and the slurry is uniformly coated on both sides of the foil material through a high-precision coating head (such as a slit extrusion type). The coated wet electrode sheet is immediately transferred to a drying oven with multiple temperature zones and a length of tens of meters. The solvent is dried at a precisely controlled temperature to form a strong coating.

Roll pressing and slitting: After drying, the polarizer is rolled by a hydraulic precision rolling machine to compact the coating to a predetermined thickness and density, ensuring close contact between the active substance and the current collector. Subsequently, the wide width polar coil material is cut into several narrow strips of the required width by a high-speed slitting machine according to design requirements, and automatically wound up.

The core value of this process lies in the fully automated production, which ensures a high degree of consistency in key parameters such as coating weight, thickness, and density of the polarizer. Precise tension control avoids wrinkling or stretching of the foil material; Uniform coating and stable compaction density are fundamental prerequisites for ensuring the final energy density, internal resistance consistency, and cycle life of batteries.