Coiling needle of square lithium battery

Abstract

The invention discloses a coiling needle of a square lithium battery. The coiling needle of the square lithium battery comprises a needle core and a shell, wherein two sides of the needle core have protruded acute angles and are of scabbard shapes, the inside of the needle core is hollow, through holes are uniformly distributed in the side wall of the needle core, the base part of the needle core is provided with a gas inlet communicated with the inside of the needle core, the shell is a thin shell layer wrapping the periphery of the needle core, and the thin shell layer is provided with a run-through bar-type groove. The coiling needle of the square lithium battery has high stability and good winding effect, the winding precision and the quality of the battery product are greatly improved, the scrap rate of the battery cell is lower then 10% in a winding process, and the scrap rate of a ceramic membrane is greatly reduced in a winding process.

Description

technical field [0001] The invention relates to lithium battery production equipment, in particular to a square lithium battery winding needle suitable for winding ceramic diaphragms. Background technique [0002] In the manufacturing process of lithium batteries, winding is a key step in the preparation process of cylindrical batteries and square batteries, which has a very important impact on battery consistency, service life and safety performance. [0003] Most of the existing winding machines use two halves of needles. Before winding, the two halves of needles are separated. There is a gap between the two halves of needles for the diaphragm to penetrate. After the diaphragm is penetrated, the two halves are separated. The needles will be combined into a whole and wound together with the diaphragm clamped. [0004] During the winding process, with the gradual increase of the winding diameter, the winding needle will be gradually wound and squeezed. After the winding is ...

AI Technical Summary

Problems solved by technology

This phenomenon is more obvious in the lithium battery system using the ceramic diaphragm. Since the ceramic coating on the surface of the ceramic diaphragm is relatively rough, the sliding friction force generated when it is in direct contact with the surface of the winding needle is too large, so that the winding needle is pulled out from the middle of the winding core. Difficulty, even the inner membrane of the core will be taken out, which will damage the alignment of the core and cause the core to be scrapped

At the same time, the two halves of the winding needle made of metal material will generate a large mechanical force when they are combined, which is easy to cause damage to the inner diaphragm and increase the risk of short circuit of the winding core

The existence of these problems will greatly reduce the winding pass rate of lithium-ion batteries using ceramic separators. The scrap rate of ceramic separators when using ordinary two-half needles for winding ceramic separators is as high as 30%, resulting in unnecessary waste of materials.

Images