Manufacturing method of winding needle, manufacturing method of lithium ion battery and lithium ion battery

Abstract

The invention discloses a manufacturing method of a winding needle. The manufacturing method comprises the steps of: measuring the length, width and thickness of a designed square soft package wound lithium ion battery to be manufactured; calculating a deformation coefficient of the lithium ion battery, with the deformation coefficient satisfying the formula of: the deformation coefficient=a length-width ratio*a length-thickness ratio*a thickness-width ratio; and according to the deformation coefficient, determining the ratio of a short shaft to a long shaft of an elliptic winding needle, determining the circumference of the elliptic winding needle according to the specification of the lithium ion battery to be manufactured, and manufacturing the winding needle meeting the demands according to a defined ratio of a short semi-shaft to a long semi-shaft of the elliptic winding needle. The invention also discloses a manufacturing method of a corresponding square soft package wound lithium ion battery and the square soft package wound lithium ion battery. The lithium ion battery manufactured by the manufacturing method disclosed in the invention still maintains its original shape and has no deformation after repeated charge-discharge use, so that the service life of the battery is improved, and the product using the battery can be better protected.

Description

[0001] technical field [0002] The invention relates to a rolling pin for rolling lithium ion batteries, in particular to a manufacturing method of the rolling pin, a manufacturing method of a square soft package winding lithium ion battery and a square soft package winding lithium ion battery. [0003] Background technique [0004] Square soft-pack lithium-ion batteries are widely used in digital products, especially under the leadership of the trend represented by Apple's iphone and ipad, square soft-pack lithium-ion batteries have developed faster. For different digital products, the volume and type of square soft-pack lithium-ion batteries required are different. Square soft-pack lithium-ion batteries are divided into stacked soft-pack lithium-ion batteries and wound-type soft-pack lithium-ion batteries according to different processing methods. Among them, the wound-type lithium-ion batteries have high processing efficiency and high cost performance, so they have broa...

AI Technical Summary

Problems solved by technology

[0006] However, after flattening, the gap between layers at the inflection point of the multilayer structure of the cell winding body in some types of batteries is too small. The deformation of materials such as separator or separator will lead to the destruction of the multi-layer structure of the cell winding body, the layers may contact each other, and the appearance of the lithium-ion battery may also appear S-shaped deformation, which will affect the battery. use, and even cause damage to digital products

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