Lithium ion battery insulating coating, preparation method and pole piece and lithium ion battery using insulating coating

Abstract

The invention discloses a lithium ion battery insulating coating, a preparation method and a pole piece and a lithium ion battery using the insulating coating, and belongs to the technical field of lithium ion batteries. The effective components of the lithium ion battery insulating coating disclosed by the invention is formed by inorganic powder, an adhesive and a dispersing agent, wherein the three components generate a synergistic effect to improve the uniformity and stability of the insulating coating and improve the resistance uniformity of an insulating coating layer formed by the insulating coating, and the bonding strength with an aluminum foil matrix for the pole piece is high, thereby being unlikely to drop. The preparation method of the lithium ion battery insulating coating disclosed by the invention is easy to operate and is suitable for industrialized promotion and application, the inorganic powder, the adhesive and the dispersing agent are mixed in a high speed stirring and dispersing manner, so as to improve the uniformity and stability of the insulating coating, and the insulating coating is free of such phenomena as lamination and settlement after being stored for a long term. The lithium ion battery prepared by the insulating coating disclosed by the invention is good in safety performance and is stable in electrochemical performance.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to an insulating coating for lithium ion batteries, a preparation method, pole pieces and lithium ion batteries using the insulating coating. Background technique [0002] The main reasons for the failure of lithium-ion batteries are overcharging, overheating, short circuit and so on. Overcharging and overheating can be solved by external methods such as PTC, fuse, and cooling equipment, but short circuit is difficult to solve by external methods, and can only be improved from the inside of the lithium-ion battery. From a theoretical analysis, although the cause of the short circuit is quite complicated, the result is the short circuit of the positive and negative poles. According to the short circuit contact method of the positive and negative poles, the internal short circuit can be divided into four types as shown in Table 1 below: [0003] Table 1 Diff...

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Problems solved by technology

[0006] At present, the production, use and testing cannot completely avoid the occurrence of internal short circuit problems. Usually, tapes are used to insulate the tabs, dressing edges and scribed areas to solve the internal short circuit problem. However, this insulation The tape is thick, and at the same time, the manual operation is heavy, the process is complicated, and the production efficiency is low. Moreover, the tape has defects such as long-term soaking failure, dissolution of viscous material, electrolyte contamination, deformation and failure at high temperature, etc., which affect the performance of lithium-ion batteries. Aiming at the defects of insulating tape, an insulating coating has been developed in the prior art, which can be coated on areas such as tabs, dressing edges, and markings to achieve insulation and prevent short circuits. For example, Chinese patent CN101867070B discloses an inorganic An insulating coating composed of oxides and binders, but the coating is not easy to coat evenly, and the insulation performance of the coating is not uniform.

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