CN215118999U

CN215118999U - Battery core is convoluteed with rolling up needle subassembly and battery manufacture equipment

Info

Publication number: CN215118999U
Application number: CN202120954850.0U
Authority: CN
Inventors: 王恒; 占克军; 杨高光; 梁东建; 桂亚林
Original assignee: Dongguan Weike Battery Co ltd
Current assignee: Dongguan Weike Battery Co ltd
Priority date: 2021-05-07
Filing date: 2021-05-07
Publication date: 2021-12-10
Anticipated expiration: 2031-05-07

Abstract

The utility model provides a winding needle component for winding an electric core, which comprises a first winding needle and a second winding needle; the first winding needle comprises a first winding part and a second winding part; the thickness of the first roll part is smaller than that of the second roll part; the second winding needle is arranged opposite to the first winding needle, and at least a part of overlapping area exists between the second winding needle and the first winding needle; the second winding needle comprises a third winding part and a fourth winding part, and the thickness of the fourth winding part is smaller than that of the third winding part; the first winding part, the second winding part, the third winding part and the fourth winding part are sequentially arranged along the winding direction of the battery cell, the outer side wall of the first winding part protrudes out of the second winding part, and the outer side wall of the fourth winding part protrudes out of the third winding part. Compared with the prior art, via the utility model discloses the electric core that obtains is convoluteed to the book needle subassembly that has the radian, has obviously improved the phenomenon that electric core negative pole piece deciduate after partial volume is full of the electricity for the first time.

Description

Battery core is convoluteed with rolling up needle subassembly and battery manufacture equipment

Technical Field

The utility model relates to a lithium cell field, concretely relates to electricity core is convoluteed with rolling up needle subassembly and battery manufacture equipment.

Background

With the rapid development of the electronic product market, people have higher and higher requirements on the energy density and safety of lithium ions in electronic products. In the current aqueous formulation of the negative electrode, the proportion of the binder needs to be reduced to increase the proportion of the negative active material so as to increase the cell energy density. The production process of the battery core with the winding structure is mature, the production efficiency is high, and the battery core with the winding structure also has the advantage of high energy density, and is the most main structure of the current lithium ion battery.

In the production process of the battery core, winding is the most critical step of battery core forming, and generally, the positive plate, the diaphragm and the negative plate are placed on a winding needle with a rectangular top view for winding, and after winding, the winding core is drawn out from the winding needle. When the negative binder is reduced for improving the energy density of the battery core, the bonding force between the negative material and the current collector is reduced, and when the square winding needle is used for winding the pole piece, the winding tension on the edges of the pole piece is greater than that in the middle, so that the stress on the edges of the pole piece is easy to generate and cannot be released. This causes the following problems: after the core is filled with liquid, is formed and is charged for the first time in a capacity grading way, lithium ions migrate from the positive electrode to the negative electrode, the negative active material expands, the temperature of the pole piece rises, stress is released, the negative material is stripped from the edge of the pole piece, namely the upper part and the lower part of the battery, the upper part and the lower part of the battery core are bulged, the battery is extremely thick, when the battery is impacted and shaken and the like, the negative material separated from the current collector easily breaks through a diaphragm, then the negative material is contacted with the positive electrode, and safety risks such as short circuit, fire and the like occur.

In order to solve the above problems, it is common in the industry to use a binder with better adhesion to improve the adhesion of the negative electrode to the current collector, but the cost of each corresponding cell increases, and it is not possible to eliminate the stress generated at the edge of the pole piece during winding, and when the cell is first fully charged, the stress is released, and the negative electrode material is still stripped, so that when the energy density is improved by increasing the proportion of the active material, even if the binder with better adhesion is used, the problem of stripping of the negative electrode material due to the fact that the stress cannot be timely released cannot be solved.

In view of the above, it is necessary to provide a technical solution to the above problems.

SUMMERY OF THE UTILITY MODEL

One of the purposes of the utility model lies in: the utility model provides a coil needle subassembly is used in electric core coiling to solve present negative pole piece when coiling its both sides edge produce stress easily and can't in time release the problem.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a winding needle assembly for winding a battery cell comprises:

a first winding needle including a first winding part and a second winding part; the thickness of the first roll part is smaller than that of the second roll part;

the second winding needle is arranged opposite to the first winding needle, and at least a part of overlapping area exists between the second winding needle and the first winding needle; the roll comprises a third roll part and a fourth roll part, wherein the thickness of the fourth roll part is smaller than that of the third roll part;

the first winding part, the second winding part, the third winding part and the fourth winding part are sequentially arranged along the winding direction of the battery cell, the outer side wall of the first winding part protrudes out of the second winding part, and the outer side wall of the fourth winding part protrudes out of the third winding part.

Preferably, the top view of the outer side walls of the first roll portion and the fourth roll portion is any one of an arc shape, a curved shape formed by sequentially connecting and folding a plurality of straight lines, and a curved shape formed by connecting a plurality of straight lines and an arc shape.

Preferably, the arc is a circular arc or an elliptical arc.

Preferably, the thicknesses of the second roll portion and the first roll portion are gradually decreased, and the thicknesses of the third roll portion and the fourth roll portion are gradually decreased.

Preferably, the first roll portion and the fourth roll portion have the same shape and size.

Preferably, the first winding needle further comprises a fifth winding part, and the fifth winding part is arranged on two sides of the second winding part opposite to the first winding part; the second winding needle further comprises a sixth winding part, and the sixth winding part and the fourth winding part are oppositely arranged on two sides of the third winding part.

Preferably, the thickness of the fifth rolling part is smaller than that of the second rolling part, and the outer side wall of the fifth rolling part protrudes out of the second rolling part; the thickness of the sixth rolling part is smaller than that of the third rolling part, and the outer side wall of the sixth rolling part protrudes out of the third rolling part.

Preferably, the fifth roll portion has the same shape and size as the first roll portion; the sixth roll is the same in shape and size as the third roll.

Preferably, the second roll portion corresponds to and overlaps with the third roll portion, the first roll portion corresponds to and overlaps with the sixth roll portion, and the fourth roll portion corresponds to and overlaps with the fifth roll portion.

Another object of the present invention is to provide a battery manufacturing apparatus including the winding pin assembly for winding a battery cell according to any one of the above aspects.

Compared with the prior art, the beneficial effects of the utility model reside in that:

1) the utility model provides a needle rolling component, the thickness of a first rolling part and a fourth rolling part which are arranged at the two sides of the needle rolling component is respectively smaller than that of a second rolling part and that of a third rolling part, meanwhile, the outer side walls of the first rolling part and the fourth rolling part are protruded out of two sides, so that when the pole piece is wound, not only can the higher thickness of the second and third wraps provide support for the upper portion of the core, and the convex parts of the first roll part and the fourth roll part can also provide supporting force for the side part of the roll core, so that the roll core can be wound more smoothly on one hand, and the convex parts can also greatly reduce the stress on the edge of the pole piece on the other hand, so that the stress condition of the edge of the pole piece is consistent with that of the middle part when the pole piece is wound, thereby avoiding the situation that the negative pole piece is stripped because the edge stress can not be effectively released in the processes of capacity grading, full charging and temperature rise, particularly in the case where the cell energy density is increased by increasing the negative electrode active material content.

2) The utility model provides a roll up needle subassembly solves the problem that its both sides edge produced stress easily and can't in time release when convoluteing through the structural design who changes roll up the needle, can not increase the raw and other materials cost and the processing procedure of electric core, and the practicality is higher, and maneuverability is stronger.

Drawings

Fig. 1 is one of the structural schematic diagrams of the needle winding assembly of the present invention.

Fig. 2 is a front view of the needle assembly of fig. 1.

Fig. 3 is a top view of the needle assembly of fig. 1.

Fig. 4 is an exploded view of the needle assembly of fig. 1.

Fig. 5 is a second schematic structural view of the needle winding assembly of the present invention.

Fig. 6 is an exploded view of the needle assembly of fig. 5.

Fig. 7 is an enlarged view of a in fig. 6.

In the figure: 1-a first winding needle; 11-a first roll; 111-the outer side wall of the first roll; 12-a second roll; 2-second winding needle; 21-a third roll; 22-a fourth wrap; 221-outer sidewall of the fourth wrap.

Detailed Description

In order to make the technical solutions and advantages of the present invention clearer, the present invention and its advantageous effects will be described in further detail below with reference to the accompanying drawings of the detailed description and the specification, but the present invention is not limited thereto.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The utility model discloses the standard part that uses all can purchase from the market, and dysmorphism piece all can be customized according to the description with the record of drawing of description, and the concrete connection mode of each part all adopts conventional means such as ripe bolt, rivet, welding among the prior art, and machinery, part and equipment all adopt prior art, and conventional model, including circuit connection adopts conventional connection mode among the prior art, does not detailed here again.

Example 1

As shown in fig. 1 to 7, a winding needle assembly for winding a battery cell includes a first winding needle 1 and a second winding needle 2; the first winding needle 1 comprises a first winding part 11 and a second winding part 12; the thickness of the first roll part 11 is smaller than that of the second roll part 12; the second winding needle 2 is arranged opposite to the first winding needle 1, and at least a part of overlapping area exists between the second winding needle and the first winding needle 1; the second winding needle 2 comprises a third winding part 21 and a fourth winding part 22, and the thickness of the fourth winding part 22 is smaller than that of the third winding part 21; the first winding part 11, the second winding part 12, the third winding part 21 and the fourth winding part 22 are sequentially arranged along the cell winding direction, the outer side wall 111 of the first winding part protrudes from the second winding part 12, and the outer side wall 221 of the fourth winding part protrudes from the third winding part 21.

Wherein, first book needle 1 and second book needle 2 can be the same structural design, also can be for the structural design that matches, be the symmetry setting, can be that first book needle 1 is for rolling up the needle, and second book needle 2 is for rolling up the needle down, also can be vice versa. The first winding needle 1 and the second winding needle 2 can be made of metal or acrylic materials, and after the first winding needle 1 and the second winding needle 2 are assembled into the winding needle assembly, the winding needle assembly can be a full-automatic winding needle assembly, a semi-automatic winding needle assembly or a pure-manual winding needle assembly.

In addition, the first winding needle 1 and the second winding needle 2 at least have a part of overlapping area, and the winding of winding cores with different sizes can be adapted through the adjustment of the overlapping area, when the winding core is smaller, the overlapping area of the first winding needle and the second winding needle can be timely increased, and when the required winding core is larger, the overlapping area of the first winding needle and the second winding needle can be timely reduced.

Further, the protruding structure of the outer sidewall 221 of the first roll 11 and the fourth roll includes, but is not limited to, the following structures:

1) the outer side wall 221 of the first roll 11 and the fourth roll has an arc shape in plan view. The arc shape in the top view direction may be a circular arc shape or an elliptic arc shape. This curved concrete radian can set up according to the design of actually rolling up the core, and when rolling up the core great, this curved radian can increase thereupon to better unload the stress at negative pole piece edge, and when rolling up the core less, then the radian with the adaptation coil design can, do not too much injectd here.

2) The top view of the outer sidewalls 221 of the first and fourth rolled

portions

11 and 221 is a curved shape formed by sequentially connecting and folding a plurality of straight lines. The pole piece is composed of a part of sides of a polygon, the number of the sides of the polygon is preferably larger than or equal to six, and the connection of the sides is more gradual when the number of the sides is more, so that the stress of the edge of the pole piece is more favorably relieved.

3) The top view of the outer side wall 221 of the first roll 11 and the fourth roll is a curved shape formed by connecting a plurality of straight lines and arcs. The curved shape of the term can be considered as an arbitrary combination of 1) and 2) above.

Further, the thicknesses of the second roll portion 12 and the first roll portion 11 are gradually decreased, and the thicknesses of the third roll portion 21 and the fourth roll portion 22 are gradually decreased. The gradual thickness reduction is more favorable for winding the pole piece, the winding is tighter, and the stress of each part of the pole piece is more consistent.

Further, the first roll portion 11 and the fourth roll portion 22 have the same shape and size. Correspondingly, the second roll part 12 and the third roll part 21 have the same shape and size, that is, the first roll needle 1 and the second roll needle 2 have the same structural design, and the same structural design is more beneficial to automatic setting on one hand and production and application of enterprises on the other hand.

Further, the first winding needle 1 further comprises a fifth winding part, and the fifth winding part is arranged on two sides of the second winding part 12 opposite to the first winding part 11; the second winding needle 2 further includes a sixth winding portion, and the sixth winding portion and the fourth winding portion 22 are oppositely disposed on two sides of the third winding portion 21.

Further, the thickness of the fifth rolling part is smaller than that of the second rolling part 12, and the outer side wall of the fifth rolling part protrudes from the second rolling part 12; the thickness of the sixth rolling part is smaller than that of the third rolling part 21, and the outer side wall of the sixth rolling part protrudes out of the third rolling part 21. This design of fifth book portion and sixth book portion is mainly when rolling up needle 2 and overlapping completely to first book needle 1 and second, adds fifth book portion and sixth book portion again, can guarantee like this to roll up the needle both sides and still have thickness reduction and the convex structural design of lateral wall, and then guarantee that the atress at negative pole piece edge is unanimous with middle atress size.

Further, the fifth roll portion is the same in shape and size as the first roll portion 11; the sixth roll has the same shape and size as the third roll 21.

Further, the second roll portion 12 corresponds to and overlaps the third roll portion 21, the first roll portion 11 corresponds to and overlaps the sixth roll portion, and the fourth roll portion 22 corresponds to and overlaps the fifth roll portion.

Example 2

A battery manufacturing apparatus including the cell winding needle assembly of embodiment 1.

Specifically, will the utility model discloses a book needle subassembly is specifically applied to electric core and is convoluteed, and wherein the electric core model is 377295 (thickness 3.7mm, width 72mm, height 95mm), and the design of negative pole piece is: the negative electrode active material accounts for 97.8%, and the binder accounts for 1.2%. The longest width of the winding needle assembly is 66.5mm (including the part with the convex outer side wall, and the width of the convex part is 2mm) to wind the battery core. In addition, a comparative cell was also wound using a conventional square winding needle assembly, which also had a longest width of 66.5mm, but which did not have a design with a protruding outer sidewall.

Tests show that the thickness of the main body of the battery cell prepared by the winding needle assembly is uniform and meets the design thickness, the battery cell is disassembled after the battery cell is fully charged for the first time in a capacity division manner, and the film release rate of the upper edge and the lower edge of the negative plate is 0%. And then find the position outward appearance of battery core week side (being the edge of negative pole piece) and swell in the test of contrast electric core, week side thickness has surpassed the middle part position of electric core, causes electric core main part to surpass design thickness, and electric core and disassemble after the partial volume is full of the electricity for the first time, and the stripping rate of negative pole piece upper and lower edge has reached 96%.

Therefore, use the utility model discloses the electric core that the book needle subassembly that has the radian was convoluteed and is obtained has obviously improved electric core and has been full of the phenomenon of electricity back negative pole piece deciduate for the first time in the partial volume, and electric core main part thickness is more even, and the coiling effect is better.

Variations and modifications to the above-described embodiments may become apparent to those skilled in the art from the disclosure and teachings of the above description. Therefore, the present invention is not limited to the above-mentioned embodiments, and any obvious modifications, replacements or variations made by those skilled in the art on the basis of the present invention belong to the protection scope of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. The utility model provides a battery core is convoluteed with book needle subassembly which characterized in that includes:

2. The winding needle assembly for winding the battery cell according to claim 1, wherein the top view of the outer side walls of the first winding portion and the fourth winding portion is any one of an arc shape, a curved shape formed by sequentially connecting a plurality of straight lines and a folded shape, and a curved shape formed by connecting a plurality of straight lines and an arc shape.

3. The winding needle assembly for winding the battery cell according to claim 2, wherein the arc shape is a circular arc shape or an elliptical arc shape.

4. The winding pin assembly for winding the battery cell according to any one of claims 1 to 3, wherein the thicknesses of the second winding portion and the first winding portion are gradually decreased, and the thicknesses of the third winding portion and the fourth winding portion are gradually decreased.

5. The winding pin assembly for winding a battery cell according to claim 4, wherein the first winding part and the fourth winding part have the same shape and size.

6. The winding needle assembly for winding the battery cell according to claim 1, wherein the first winding needle further comprises a fifth winding portion, and the fifth winding portion is disposed on two sides of the second winding portion opposite to the first winding portion; the second winding needle further comprises a sixth winding part, and the sixth winding part and the fourth winding part are oppositely arranged on two sides of the third winding part.

7. The winding pin assembly for winding the battery cell according to claim 6, wherein the thickness of the fifth winding part is smaller than that of the second winding part, and an outer side wall of the fifth winding part protrudes from the second winding part; the thickness of the sixth rolling part is smaller than that of the third rolling part, and the outer side wall of the sixth rolling part protrudes out of the third rolling part.

8. The winding pin assembly for winding a battery cell according to claim 7, wherein the fifth winding part has the same shape and size as the first winding part; the sixth roll is the same in shape and size as the third roll.

9. The battery cell winding needle assembly according to claim 8, wherein the second winding portion corresponds to and overlaps the third winding portion, the first winding portion corresponds to and overlaps the sixth winding portion, and the fourth winding portion corresponds to and overlaps the fifth winding portion.

10. A battery manufacturing apparatus comprising the winding pin assembly for winding a battery cell according to any one of claims 1 to 9.