Winding needle

Abstract

A winding needle comprises an outer cover and two oppositely-arranged winding needle outer sleeve main bodies, a base material clamping space is formed between the two winding needle outer sleeve mainbodies, and each winding needle outer sleeve main body comprises a needle base groove. An outer needle seat and a clamping needle are arranged in the needle seat groove, the groove bottom of the needle seat groove extends outwards to form a forming part with a gradually reduced sectional area, and a telescopic winding needle outer sleeve auxiliary body is installed on the forming part through anadjusting assembly. Two or more plug pins are installed on the winding needle outer sleeve auxiliary body, the lower ends of the plug pins extend into plug pin holes of the forming part, and plug pinconnecting rod bodies are installed in the plug pin connecting rod holes. First inclined faces are arranged at the bottoms of the plug pins, second inclined faces corresponding to the first inclined faces are arranged on the plug pin connecting rod bodies, and a magnetic attraction piece is arranged between the winding needle outer sleeve auxiliary body and the forming part. In the winding processof the battery cell, the internal interlayer space of a winding core is increased by dynamically adjusting the overall appearance perimeter of the winding needle, so that the problem of S-shaped deformation of the battery cell caused by the tension shrinkage and pole piece expansion of a pole piece and an isolating membrane in the winding process of the battery cell can be effectively solved.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a winding needle. Background technique [0002] With the development of the electric vehicle market, the demand for batteries is increasing and the demand for capacity is increasing. Therefore, the battery cells have become thicker and thicker. Most lithium-ion batteries for electric vehicles still use a wound structure, and the problem of "S-shaped" deformation often occurs in the wound structure, especially when the thickness of the winding core is getting thicker and thicker. There are mainly two reasons for this kind of phenomenon: 1) winding process reason: in the winding process, it is necessary to apply a certain pulling force to the positive electrode sheet, negative electrode sheet, and separator in the direction of tape travel to ensure that the positive electrode sheet, negative electrode sheet, The degree of alignment between the separators to ensure th...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a winding needle that solves the winding deformation of lithium-ion batteries, aiming to solve the "S-shaped" deformation of the battery core caused by the shrinkage of the pole piece and the separator due to the tensile force and the expansion of the pole piece in the existing battery winding process The problem

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