An Extrusion Coating Die Spacer that Eliminates Coating Edge Effects

Abstract

The invention discloses an extrusion coating type die gasket capable of eliminating the coating edge effect, and belongs to the technical field of lithium battery coating. An extrusion coating type die gasket capable of eliminating the coating edge effect, comprising a die gasket body, a discharge port is arranged in the die gasket body, and the die gasket body includes a lower gasket and a fixing device The upper extension gaskets on the left and right upper ends of the lower gasket, the space formed between the inner wall of the lower gasket and the two upper extension gaskets form the discharge port, and the ends of the two upper extension gaskets that are close to each other are provided for improving the pulp. The chamfering structure of the fluid pressure at the edge of the upper extension gasket flows through the discharge port, which can stabilize the fluid pressure at the edge of the die lip when the slurry is coated, and the velocity distribution of the slurry squeezed out from the slit is uniform , The edge thickness of the coated film surface is highly consistent, which can more effectively control the thickness of the coating film on the coating edge and the range of abnormal areas on the edge of the coating film, and realize multiple continuous coatings.

Description

technical field [0001] The invention relates to the technical field of lithium battery coating, in particular to an extrusion coating type die gasket capable of eliminating the coating edge effect. Background technique [0002] With the rapid development of new energy vehicles in recent years, the requirements for the safety, consistency, and energy density of lithium-ion power batteries are getting higher and higher. If you want to improve the safety of batteries, the consistency of batteries , Improving the energy density of the battery cell is very important for how to ensure the stability of the coating surface density and the consistency of the thickness during the manufacturing process of the battery cell. How to ensure the consistency of the surface density of the coating and the stability of the coating thickness directly affect the consistency of the battery cell and the safety of the battery system. [0003] As a high-precision, intelligent, and stable production ...

AI Technical Summary

Problems solved by technology

[0004] The electrode slurry is at the outlet of the lip of the coating die, and the edge of the die gasket is often where the fluid pressure is the highest. The electrode slurry is coated on the current collector, which is prone to bulging; if the positive electrode bulging is serious, it will easily cause roll Cracking on the edge of the pole piece during the pressing process, severe wavy edges on the pole piece edge after slitting, severe bulging of the negative electrode, excessive compaction density on the pole piece edge after rolling, and electrode cell edge cracking after cycling. Lithium, a safety hazard

[0005] Although the prior art has proposed a method of improving the flow of slurry inside the extrusion die by setting chamfers on the outer edge of the discharge port of the die gasket, this method can eliminate the dead zone of the slurry to a certain extent, Improve the coating effect on the edge of the discharge port so as to avoid the bulging phenomenon of the pole piece, but this type of gasket cannot effectively reduce the thickness of the coated edge material area in the actual application process, and the industrial coating process can reduce the thickness of the thinned area. Both thickness and width have certain requirements, and the thinning area cannot be effectively controlled

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