Coating design method for lowering battery short circuit rate

Abstract

The invention discloses a coating design method for lowering the battery short circuit rate. A coating area is alternately distributed into areas A, areas B, areas C, areas D and areas E transversely,that is, the coating area is in an ABCDE-ABCDE-ABCDE mode, wherein the width of the areas A is La, the width of the areas B is Lb<5 mm, the coating singe-face thickness is Hb<=5 micrometers, the width of the areas C is Lc, and the coating thickness is Hc; the width of the areas D is Ld<5 mm, the coating single-face thickness is Hd<=5 micrometers, and the width of the areas E is Le. After coatingof pole piece sizing agent in the areas C is completed, the areas B and the areas D are coated with a layer of sizing agent, and the areas A and E are lead areas. The coating design method has the advantages that by the adoption of the optimized pole piece coating method, burrs caused by pole piece slitting can be reduced to a great degree, and the short circuit rate of a battery is lowered; meanwhile, wrinkles when active material coating areas and copper aluminum foil are nonuniform in extension after being rolled are reduced greatly.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a coating design method for reducing the short circuit rate of batteries. Background technique [0002] With the popularization and application of lithium-ion power batteries in electric buses, passenger cars and other fields, various battery companies develop advanced technologies and improve the automation level of production lines to improve the consistency and yield of batteries. In the production process of lithium-ion batteries, the burrs caused by the cutting and forming of the pole pieces will cause the breakdown of the diaphragm and the short circuit of the positive and negative electrodes during the high-voltage micro-short circuit test, resulting in battery failure and seriously reducing the yield of the battery; The micro-short circuit of a single battery cell that is not easy to detect will cause inconsistency between batteries, making the module unusable. ...

AI Technical Summary

Problems solved by technology

In the production process of lithium-ion batteries, the burrs caused by the cutting and forming of the pole pieces will cause the breakdown of the diaphragm and the short circuit of the positive and negative electrodes during the high-voltage micro-short circuit test, resulting in battery failure and seriously reducing the yield of the battery; The micro-short circuit of a single battery cell that is not easy to detect will cause inconsistency between batteries, making the module unusable

[0003] During the slitting and forming process of the positive and negative electrodes, especially at the junction of the material area and the tab, the blank copper and aluminum foil is very thin and has strong ductility, which is not easy to slit and is more likely to form burrs

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