Coating method for battery pole piece

Abstract

The invention relates to a pole piece coating method, which uses a back roller to drive the current collector to move, and coats the slurry on the rotating coating roller on the surface of the current collector. When the length of the slurry on the current collector reaches a preset length, the The coating roller is separated from the current collector on the back roller to form a blank strip. When the length of the blank strip reaches the preset length, the coating roller is brought into contact with the current collector on the back roller again, and the above steps are repeated continuously to form multiple strips on the current collector. Blank belt, in which, after the coating roller is separated from the current collector on the back roller, reduce the speed of the coating roller, and when the coating roller contacts the current collector on the back roller again, gradually increase the speed of the coating roller to reach the preset speed . After the coating roller of the present invention is separated from the current collector, its rotational speed becomes smaller, and at the moment when the coating roller and the current collector are in contact again, it can ensure that the slurry on the coating roller and the current collector have a relatively small relative speed, so that the A dragging phenomenon occurs on the pole piece.

Description

【Technical field】 [0001] The invention relates to a battery processing method, in particular to a method for coating pole pieces of nickel hydrogen batteries and lithium ion batteries. 【Background technique】 [0002] The pole pieces of nickel metal hydride batteries and lithium ion batteries are prepared by coating slurry on the current collector. In order to connect the tabs, it is necessary to set a blank strip on the current collector. Usually, the blank strip is realized by segmental coating. The coating device of the coating machine such as figure 1 As shown, it includes a coating roller 1, a backing roller 2 and a doctor blade 3. Slurry 4 is set on the coating roller 1, the back roller 2 drives the current collector 5 to move, and the slurry 4 on the rotating coating roller 1 is coated on the surface of the current collector 5, and the scraper 3 can keep the slurry 4 on the coating roller 1 Has a uniform thickness. When the length of the slurry 4 on the current col...

AI Technical Summary

Problems solved by technology

However, in the above-mentioned coating process, the rotating speeds of the coating roller 1 and the backing roller 2 are constant, and during the two processes of coating the paddle 4 and reserving the blank belt 6 again, the rotating speeds of the coating roller 1 and the backing roller 2 do not change. Therefore, at the moment when the coating roller 1 and the current collector 5 on the back roller 2 are just in contact, their relative speed is relatively high, which will cause a "drag head" phenomenon on the pole piece, that is, the blank strip 6 on the pole piece is initially coated with slurry The slurry at the place is thicker and forms protrusions, figure 2 The "dragging head" phenomenon occurred at A as shown in

In the process of compacting the pole piece with a puller, the force on the puller is too large, and the material often falls off; in addition, in the process of stacking or winding the pole piece, the puller Very easy to drop material

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