Top cover assembly and lithium ion battery based on top cover assembly

Abstract

The invention provides a top cover assembly and a lithium ion battery based on the top cover assembly, and relates to the technical field of lithium ion batteries. The top cover assembly comprises a top cover sheet, a positive electrode unit, a negative electrode unit and a lower injection molding piece, wherein the lower injection molding piece is fixedly arranged on the bottom surface of the top cover sheet, the positive electrode unit and the negative electrode unit are located on one side of the top cover sheet respectively, an electrode hole is formed in each of the two ends of the top cover sheet in the length direction, the positive electrode unit and the negative electrode unit partially cover the corresponding electrode holes, the rest parts of the electrode holes extend above the top surface of the top cover sheet, each of the positive electrode unit and the negative electrode unit comprises an electrode column, a fixing piece, a sealing ring and a connecting piece, a through hole is formed in the lower injection molding sheet corresponding to the electrode column, and the bottom surface of the connecting piece is exposed out of the through hole. The lithium ion battery disclosed by the invention uses the top cover assembly. According to the top cover assembly disclosed by the invention, the assembly process of the top cover assembly is simplified, the top cover assembly yield is improved, and the occupation of the top cover assembly on the internal space of the lithium ion square aluminum shell battery can be reduced, so that the energy density of the secondary battery is improved.

Description

technical field [0001] The present disclosure relates to the field of lithium-ion batteries, in particular to a top cover assembly and a lithium-ion battery based on the top cover assembly. Background technique [0002] At present, the battery type commonly used in the power battery industry is the square aluminum shell cell. The main components of the square aluminum shell cell are the cell aluminum shell and the top cover assembly. The main function of the cell aluminum shell is to provide a closed space for the cell to accommodate The electrode assembly and electrolyte, the internal components of the electrode are connected to the positive and negative terminals of the top cover assembly to realize the electrochemical reaction. [0003] In the existing top cover components, the lower injection molded part and the top cover are generally matched by laser hot-melt fitting, and the assembly process is relatively complicated. This in turn affects the cost of the roof. [00...

AI Technical Summary

Problems solved by technology

[0003] In the existing top cover components, the lower injection molded part and the top cover are generally matched by laser hot-melt fitting, and the assembly process is relatively complicated. which in turn affects the cost of the roof

[0004] In the current common lithium-ion square aluminum shell battery technology, the Mylar sheet (Mylar sheet) is connected to the lower injection molded part by hot melting. In this method, the lower injection molded part needs to have a certain height to facilitate the hot melting of the Mylar sheet. The structure of injection molded parts reduces the internal space occupancy of the battery, which is not conducive to the improvement of energy density

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