Pole piece cutting method

Abstract

The invention provides a pole piece cutting method, which uses laser for cutting a pole piece along a predetermined cutting route. The invention adopts the cutting mode of non-physical contact; dust does not exist in the cutting process; after cutting, the fracture position of the pole piece does not have burr; the cutting method is particularly suitable for the cutting of the pole piece, the fracture of which takes on irregularly shape; the pole piece in the cutting process is not acted by mechanical force; the interior of the pole piece does not generate mechanical stress, and the crystalline phase organization of the pole piece also does not change; and the cutting method of the invention can ensure the process stability of the pole piece cutting and is beneficial to increase the quality of an electrical core and the percent of pass of a battery.

Description

【Technical field】 [0001] The invention relates to battery manufacturing technology, in particular to a pole piece cutting method with reliable performance. 【Background technique】 [0002] The currently widely used cell stacking technology, especially the cell stacking technology of the power battery, needs to cut the pole piece of the cell into the length required for stacking by mechanical cutting from the rolled material before stacking. Since the pole piece is coated with polar materials, such as graphite, lithium cobaltate, etc., mechanical cutting will cause dust to be generated when the pole piece is cut. In addition, mechanical cutting will also produce burrs at the fracture of the pole pieces. The burrs may puncture the diaphragm between the positive and negative pole pieces and cause a short circuit between the positive and negative poles of the battery. In severe cases, the battery may explode. Moreover, the life of the mechanical cutter will be affected by the ma...

AI Technical Summary

Problems solved by technology

In addition, mechanical cutting will also produce burrs at the fracture of the pole pieces. The burrs may pierce the diaphragm between the positive and negative pole pieces and cause a short circuit between the positive and negative poles of the battery. In severe cases, the battery will explode.

Moreover, the service life of the mechanical cutter will be affected by the material of the pole piece. After a period of use, maintenance is required, and the maintenance and repair costs are relatively high, and the mechanical cutter is not suitable for cutting pole pieces with irregular fracture shapes.

In addition, the mechanical cutting method is adopted. When cutting, the cutter directly makes physical contact with the pole piece, and the cutter will exert a certain force on the pole piece. This force may deform the pole piece or make its snake bend larger. At the moment of cutting off, a huge tangential force will be generated to change the crystal structure of the pole piece, thus affecting the performance of the battery

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