Winding needle, wound battery cell and production process of wound battery cell

Abstract

The invention discloses a winding needle which is a columnar needle body made of an insulating rigid material. The winding needle is a columnar needle body made of an insulating rigid material, and the winding needle is wound in a diaphragm and a tab and is packaged into a battery shell along with a battery cell, so that the operation of pulling out a winding needle in the prior art is avoided, and the alignment degree of a wound battery cell is ensured, and the battery cell defect caused by the pulling-out of a silver winding needle in the existing technology is overcome. When the interior ofthe battery cell is short-circuited, the winding needle and a winding body ascend at the same time to press a safety valve on a battery cap, in order to realize rapid pressure relief and overcome thedefect that a center needle is separated from a battery cell due to gap. Heating is fast in the charging and discharging process, and due to winding tension, the pole pieces of the battery cell deform and extrude towards the inner ring of the battery cell, and the diaphragm looses and even collapses. Compared with the center needle, there is no gap between the winding needle and the diaphragm, the winding needle can well support the battery cell, and the looseness or collapse probability of the diaphragm is reduced. The invention further discloses a wound battery cell comprising the winding needle and a production process of the wound battery cell.

Description

technical field [0001] The invention relates to the technical field of lithium battery production, in particular to a winding needle, a winding battery core and a production process for the winding battery core. Background technique [0002] The rolling needle is one of the main tools for preparing wound batteries. The needle rolls in the prior art, as disclosed in CN206441823U and CN101212069A, are mostly composed of two roll needle units made of stainless steel. The needle roll units respectively include a needle body and a fixing seat, and the function of the fixing seat is to fix the needle body. onto the winding device. When winding, the diaphragm is inserted between the needle bodies of the two needle coiling units and clamped. The assembly planes of the two halves of the needle coils are attached to the diaphragm and merged into a cylinder or a nearly cylindrical whole. The fixed seat and the winding machine Connected, the winding machine drives the winding needle t...

AI Technical Summary

Problems solved by technology

[0003] At present, there are the following problems in the winding process of the battery: due to the friction between the winding needle and the diaphragm, the following battery defects will occur during the pulling out of the winding needle: the diaphragm will cause certain damage, the inner diaphragm of the winding core will be taken out, and after the needle is pulled out, the following defects will occur: The inner ring of the diaphragm is wrinkled and deformed, which destroys the alignment of the core

However, the winding needles of the above two structures also need to be pulled out, and the defect of the battery cell caused by the needle pulling out cannot be fundamentally solved.

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