Top cover assembly for secondary battery and secondary battery

Abstract

The invention provides a top cover assembly of a secondary battery and the secondary battery. The top cover assembly of the secondary battery includes: a top cover plate, which is made of insulating plastic and has an electrode lead-out hole; a first electrode terminal, the first electrode terminal includes a terminal plate, and the terminal plate is located on one side of the top cover plate and Covering the electrode lead-out hole, and the outer peripheral surface of the terminal plate protrudes from the inner wall surface of the electrode lead-out hole; the connecting piece is respectively connected with the top cover plate and the first electrode terminal, and the first electrode terminal is fixed on the top cover plate through the connecting piece and a seal, the seal is disposed between the top cover plate and the terminal plate around the electrode lead-out hole to seal the electrode lead-out hole. While ensuring the sealing effect of the secondary battery casing, it can reduce the occupation of the internal space of the battery casing, thereby improving the energy density of the secondary battery and ensuring the reliability of the secondary battery.

Description

technical field [0001] The invention relates to the technical field of energy storage devices, in particular to a top cover assembly of a secondary battery and the secondary battery. Background technique [0002] At present, the power battery generally adopts a square hard shell structure. The power battery shell includes a shell and a top cover assembly. The power battery shell provides a closed space to accommodate the electrode assembly and electrolyte. The electric energy of the electrode assembly passes through the pole of the top cover assembly. Lead out from the confined space to the outside of the confined space. In the existing top cover assembly, the top cover plate is a metal plate and has a through hole, and the pole is divided into a base part and an extension part, and the cross-sectional area of ​​the base part is larger than the diameter of the through hole. When assembling, the base part is located under the top cover plate (that is, inside the housing), an...

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Problems solved by technology

[0003] Since a part of the pole is located inside the shell (usually 1.5-4 mm), and the sealing ring is also located inside the shell, the space utilization rate inside the battery shell will be low, resulting in low energy density of the battery, and because each pole Both columns need to be machined, making the manufacturing process complicated and expensive to manufacture

Moreover, in order to insulate the top cover plate from the electrode terminals provided thereon, it is usually necessary to arrange corresponding insulating parts between the pole and the top cover plate, thus increasing the structural complexity of the top cover assembly and increasing the The overall height of the top cover assembly results in low battery energy density

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