Power battery and top cover thereof

Abstract

The invention belongs to the technical field of a power battery, and particularly relates to a power battery and a top cover thereof. The top cover comprises a top cover sheet, and a first polar column, a second polar column, an explosion-proof valve and a liquid injecting hole arranged on the top cover sheet; the top cover sheet is provided with a first convex bump which protrudes out of the upper surface; the first convex bump forms a first convex bump accommodating part on the lower surface of the top cover sheet; a first mounting hole is formed in the first convex bump; the first polar column is mounted in the first mounting hole; the first polar column comprises a first base body part and a first column body part which extends from the first base body part downwardly; a high-temperature-resistant resistance block is arranged between the first base body part and the top cover sheet in a sleeving manner; a first conductive base block is riveted at the lower end of the first column body part; and a first insulating sealing ring is arranged between the first conductive base block and the top cover sheet in a sleeving manner. The top cover is safe and reliable, and capable of not only improving the battery energy density but also improving the overcurrent capability of the polar column surfaces; and meanwhile, by setting a riveting structure at the bottom of each polar column, the problem of unattractive appearance of the polar column surfaces caused by residual welding trace on the polar column surfaces is solved.

Description

technical field [0001] The invention belongs to the technical field of power batteries, in particular to a power battery and its top cover. Background technique [0002] With the development of modern society and the enhancement of people's awareness of environmental protection, more and more devices choose to use lithium batteries as power sources, such as mobile phones, notebook computers, power tools and electric vehicles, etc., which provides a great opportunity for the application and development of lithium batteries wide open space. Among them, lithium batteries used in electric tools and electric vehicles are generally called power batteries. [0003] As an important part of the power battery, the top cover generally includes a top cover sheet, an explosion-proof valve, a liquid injection hole, a positive pole and a negative pole, etc. Among them, the pole is the internal and external conduction part of the power battery, one end of which is connected to the externa...

AI Technical Summary

Problems solved by technology

Among them, threaded assembly is to process threads on the pole, and then use nuts to fix the pole and the top cover sheet. Since this method requires threading of the pole and nuts, the processing is complicated, the cost is high, and the assembly efficiency is low. product is heavy

The circlip assembly is to process a ring-shaped slot on the pole. By installing the circlip on the slot of the pole, it presses the top cover and other parts so that they cannot move axially, so that the pole and the pole are connected. The assembly between the top cover pieces; although this method has high reliability and can reduce the product weight compared with threaded assembly, this method also has the problems of cumbersome processing and low assembly efficiency, and there are also problems due to the circlip assembly The risk of pole loosening and battery short circuit caused by improper positioning

[0005] In addition, the above two assembly methods also have common defects: on the one hand, a riveting structure is set on the upper surface of the pole, so that welding marks are left on the surface of the pole, which makes the surface of the pole unsightly; The large "丄"-shaped installation structure makes the flow area on the surface of the pole smaller, which leads to poor flow capacity when it is connected to the external adapter piece; on the other hand, the existing top cover piece is generally a flat piece structure, so that the energy density of the battery cannot be increased by reducing the height of the pole inside the battery case

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