Adhesive sticking structure, battery cell and lithium battery

Abstract

The utility model discloses a rubberizing structure, cell and lithium battery, wherein the rubberizing structure includes roll core, skived gummed paper, connecting gummed paper and double faced gummed paper, the roll core is formed by winding pole piece and diaphragm, the skived gummed paper is arranged between the pole piece and the diaphragm, the skived gummed paper includes main part and buffer part, the buffer part is arranged between the main part and the connecting gummed paper, and the connecting gummed paper is arranged between the main part and the buffer part. The thickness of the main body part is uniform, and the buffer part is in an inclined shape with the thickness gradually reduced from the main body part to the outside; the roll core is provided with a head part, a tail part and two side surfaces, the head part and the tail part of the roll core are respectively adhered with the connecting gummed paper, each connecting gummed paper is respectively connected with the two side surfaces, each side surface is respectively adhered with the double-sided gummed paper, and the double-sided gummed paper is respectively connected with the connecting gummed paper of the head part and the connecting gummed paper of the tail part. According to the utility model, the problems of lithium separation due to sudden thickness change and poor falling safety of the battery cell caused by the existing rubberizing mode are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, and in particular mainly to a glue-sticking structure, a battery core and a lithium battery. Background Art

[0002] After the bare cell of the soft-pack lithium battery is wound, it needs to be glued in order to protect and fix the cell. Generally, there are two main locations for gluing: first, part of the glue is located between the anode and cathode plates and the diaphragm of the bare cell, so that the anode and cathode plates and the diaphragm are separated by a certain gap; second, glue is applied to the outer side of the entire bare cell so that the entire bare cell can be fixed to the aluminum-plastic film used for packaging on the outside. The above two gluing methods will cause the battery cell to have the following technical problems:

[0003] First, for the tape pasted between the anode and cathode plates and the diaphragm, since the tape has a certain thickness, the edges of the tape will have thickness step jumps and mutations due to the thickness difference with the non-taped positions, resulting in a larger gap between the anode and cathode plates. This makes it easy for lithium deposition to occur at the edges of the tape. In the later stages of the cycle, the battery cell is prone to thickness mutations due to lithium deposition problems, and may even expand and fail.

[0004] Secondly, the bonding method between the adhesive tape on the outside of the bare battery cell and the aluminum-plastic film causes the bare battery cell to be subjected to force on one side. In the drop test, the force on the bare battery cell only exists on the outermost layer, causing the bare battery cell to be easily damaged and having poor safety performance.

[0005] In view of this, it is necessary to improve the existing glue sticking method of the battery cell. Utility Model Content

[0006] In view of the deficiencies in the prior art, the utility model provides a glue sticking structure, a battery cell and a lithium battery to solve the problems of sudden thickness change and lithium deposition of the battery cell and easy damage due to falling caused by the existing glue sticking method.

[0007] The utility model discloses a glue sticking structure, including a winding core, a skived adhesive tape, a connecting adhesive tape and a double-sided adhesive tape, wherein the winding core is formed by winding a pole piece and a diaphragm, the skived adhesive tape is arranged between the pole piece and the diaphragm, the skived adhesive tape includes a main body and a buffering part, the main body has a uniform thickness, and the buffering part is inclined from the main body outward in a gradually thinning thickness; the winding core has a head, a tail and two side surfaces, the head and the tail of the winding core are both provided with the connecting adhesive tape, and each of the connecting adhesive tapes is connected to the two side surfaces, each of the side surfaces is provided with the double-sided adhesive tape, and the double-sided adhesive tape is connected to the connecting adhesive tapes at the head and the tail.

[0008] Preferably, the main body is a strip-shaped structure, and the buffer parts are provided on both sides of the main body.

[0009] Preferably, the cross-section of the skived adhesive tape is an isosceles trapezoid.

[0010] Preferably, the connecting adhesive tape is green adhesive, and the double-sided adhesive tape is double-sided hot melt adhesive.

[0011] Preferably, the connecting tape is provided with a hollow opening.

[0012] Preferably, the head portion is provided with a plurality of connecting adhesive tapes, and the tail portion is provided with a plurality of connecting adhesive tapes.

[0013] Preferably, two tabs are provided on the head of the winding core, and the connecting tape on the head passes through between the two tabs.

[0014] Preferably, the double-sided tape completely covers the side surfaces of the roll core.

[0015] The utility model discloses an electric core, comprising any of the above-mentioned adhesive bonding structures, and further comprising an aluminum-plastic film, wherein the aluminum-plastic film is coated on the outside of the winding core and connected to the double-sided adhesive paper.

[0016] The utility model discloses a lithium battery, comprising the above-mentioned battery core.

[0017] The beneficial effects of the utility model are:

[0018] By sticking thinned tape at the internal interface of the core, the gaps inside the core caused by the glue are completely filled with the tape, and the thickness mutation inside the core changes to a smooth transition, delaying the problem of expansion failure caused by lithium precipitation at the thickness mutation point in the late cycle. In addition, by setting connecting tape at the head and tail of the core and wrapping the connecting tape and the double-sided tape around the entire core to form a "safety belt" structure, when the battery cell falls, the core and the aluminum-plastic film as a whole are mutually correlated and subjected to stress, reducing the probability of the core being easily damaged due to only the outer layer of the core being subjected to stress.

[0019] Therefore, the utility model solves the problems of sudden thickness change of the battery cell, poor drop safety, and easy damage caused by the existing glue sticking method. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0021] Figure 1 It is a partial structural schematic diagram of the cross section of the roll core in the adhesive laminating structure, used to illustrate the structure of the thinned adhesive paper;

[0022] Figure 2 This is a schematic diagram of the structure of the side of the roll core in the adhesive tape structure, used to show the connecting tape and the double-sided tape.

[0023] Explanation of the reference numerals: 1. winding core; 101. head; 102. tail; 103. side; 11. pole piece; 12. diaphragm; 13. pole ear; 2. skived adhesive tape; 21. main body; 22. buffer part; 3. connecting adhesive tape; 31. hollow opening; 4. double-sided adhesive tape. DETAILED DESCRIPTION

[0024] In order to further understand the content, features and effects of the utility model, the following embodiments are given as examples and described in detail with reference to the accompanying drawings:

[0025] Reference Figure 1 and Figure 2 The utility model discloses a glue-sticking structure, including a winding core 1, which is formed by winding mutually overlapping anode and cathode electrodes 11 and a diaphragm 12, and a thinned adhesive paper 2 is arranged between the electrode piece 11 and the diaphragm 12, and the thinned adhesive paper 2 is pasted on the electrode piece 11, and the thinned adhesive paper 2 includes a main body 21 and a buffer part 22, the main body 21 is a strip-shaped structure with uniform thickness, and the buffer part 22 is integrally connected with the main body 21, and the above-mentioned buffer part 22 is arranged on both sides of the main body 21, and the buffer part 22 is inclined from the main body 21 to the outside, and the buffer part 22 makes the gap between the electrode piece 11 and the diaphragm 12 completely filled with the thinned adhesive paper 2, and the gap between the electrode piece 11 and the diaphragm 12 has a smooth transition, thereby avoiding the thickness mutation phenomenon between the electrode piece 11 and the diaphragm 12, so that the amount of active material reacting in the gap between the electrode piece 11 and the diaphragm 12 is very small, thereby delaying the problem of expansion failure caused by lithium precipitation due to thickness mutation in the late cycle. Preferably, the cross section of the skived adhesive tape 2 is an isosceles trapezoid.

[0026] Reference Figure 1 and Figure 2The core 1 is connected with a pole ear 13, and the pole ear 13 is arranged at one end of the winding structure of the core 1. The end of the core 1 is the head 101 of the core 1, and the other end is the tail 102 of the core 1. The outer surface of the core 1 is the side 103. The core 1 of the utility model has two side surfaces 103. The head 101 and the tail 102 of the core 1 are both affixed with connecting tape 3. The connecting tape 3 is in the shape of a strip. Both ends of each connecting tape 3 are connected to the two side surfaces 103 of the core 1. The two side surfaces 103 of the battery cell are each affixed with There is a double-sided tape 4, and each double-sided tape 4 is respectively connected to the connecting tape 3 of the head 101 and the tail 102, so that after the core 1 is encapsulated in the aluminum-plastic film, the aluminum-plastic film is connected to the core 1 through the double-sided tape 4 on the one hand, and on the other hand, the connecting tape 3 of the head 101 and the tail 102 can wrap the core 1 as a whole to form a "safety belt" structure. When the battery core falls, the core 1 and the aluminum-plastic film as a whole are mutually related and stressed, which reduces the probability of the core 1 being easily damaged due to only the outer layer of the core 1 being stressed.

[0027] Reference Figure 1 and Figure 2 , two tabs 13 are provided, and the two tabs 13 serve as the positive tab 13 and the negative tab 13 respectively, and the connecting tape 3 of the head 101 is provided between the two tabs 13. Preferably, the connecting tape 3 uses green glue, and the double-sided tape 4 uses double-sided hot melt adhesive, which is convenient for fixing with the aluminum-plastic film. A hollow opening 31 is provided on the connecting tape 3, and the hollow opening 31 allows the two sides of the connecting tape 3 to be interconnected, so that the electrolyte can pass through, and then infiltrate the interface of the main body of the winding core 1, reducing the probability of poor electrolyte infiltration caused by adhesive pasting. Furthermore, the connecting tape 3 of the head 101 can be provided with multiple strips, and the connecting tape 3 of the tail 102 can also be provided with multiple strips, so that the stress condition of the winding core 1 is fully improved.

[0028] Reference Figure 1 and Figure 2 Preferably, the double-sided tape 4 on each side 103 of the roll core 1 can cover part of the surface of the side 103, or completely cover the entire side 103. When the double-sided tape 4 completely covers the side 103 of the roll core 1, the side 103 of the roll core 1 will be completely fitted with the aluminum-plastic film, achieving an ideal fitting effect with optimal overall force on the roll core 1 when it falls.

[0029] The battery core disclosed in the utility model includes the above-mentioned adhesive bonding structure and also includes an aluminum-plastic film (not shown in the figure), which is coated on the outer side of the winding core 1 and is hot-melt connected with the double-sided adhesive tape 4.

[0030] The lithium battery disclosed in the utility model comprises the above-mentioned battery core.

[0031] The implementation principle and beneficial effect of the utility model are that by pasting the thinned adhesive tape 2 at the internal interface of the core 1, the gaps inside the core 1 caused by the adhesive are completely filled with the adhesive tape, and the thickness mutation inside the core 1 changes to a smooth transition, delaying the problem of expansion failure caused by lithium precipitation at the thickness mutation point in the late cycle. In addition, by arranging the connecting adhesive tape 3 at the head 101 and the tail 102 of the core 1, the connecting adhesive tape 3 and the double-sided adhesive tape 4 wrap the core 1 as a whole to form a "safety belt" structure, so that when the battery core falls, the core 1 and the aluminum-plastic film as a whole are mutually related and stressed, reducing the probability that the core 1 is easily damaged due to only the outer layer of the core 1 being stressed. Therefore, the utility model solves the problem that the battery core is prone to sudden thickness mutation lithium precipitation, poor falling safety, and easy damage caused by the existing adhesive method.

[0032] The above is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A glue-sticking structure, characterized in that: The invention comprises a winding core (1), a skived adhesive tape (2), a connecting adhesive tape (3) and a double-sided adhesive tape (4); the winding core (1) is formed by winding a pole piece (11) and a diaphragm (12); the skived adhesive tape (2) is arranged between the pole piece (11) and the diaphragm (12); the skived adhesive tape (2) comprises a main body (21) and a buffer part (22); the main body (21) has a uniform thickness; and the buffer part (22) is inclined such that the thickness gradually becomes thinner from the main body (21) to the outside. The winding core (1) comprises a head (101), a tail (102) and two side surfaces (103); the head (101) and the tail (102) of the winding core (1) are both provided with the connecting adhesive tape (3), and each of the connecting adhesive tapes (3) is connected to the two side surfaces (103); each of the side surfaces (103) is provided with the double-sided adhesive tape (4), and the double-sided adhesive tape (4) is connected to the connecting adhesive tapes (3) of the head (101) and the tail (102).

2. The adhesive bonding structure according to claim 1, characterized in that: The main body (21) is a belt-shaped structure, and the buffer parts (22) are provided on both sides of the main body (21).

3. The adhesive bonding structure according to claim 2, characterized in that: The cross section of the skived adhesive tape (2) is an isosceles trapezoid.

4. The adhesive bonding structure according to claim 1, characterized in that: The connecting adhesive tape (3) is green adhesive, and the double-sided adhesive tape (4) is double-sided hot melt adhesive.

5. The adhesive bonding structure according to any one of claims 1 to 4, characterized in that: The connecting adhesive tape (3) is provided with a hollow opening (31).

6. The adhesive bonding structure according to any one of claims 1 to 4, characterized in that: The head portion (101) is provided with a plurality of connecting adhesive tapes (3), and the tail portion (102) is provided with a plurality of connecting adhesive tapes (3).

7. The adhesive bonding structure according to any one of claims 1 to 4, characterized in that: Two pole lugs (13) are arranged on the head (101) of the winding core (1), and the connecting tape (3) of the head (101) passes between the two pole lugs (13).

8. The adhesive bonding structure according to any one of claims 1 to 4, characterized in that: The double-sided adhesive tape (4) completely covers the side surface (103) of the winding core (1).

9. A battery cell, characterized in that: It comprises the adhesive laminating structure as described in any one of claims 1 to 8, and also comprises an aluminum-plastic film, wherein the aluminum-plastic film is coated on the outside of the winding core (1) and connected to the double-sided adhesive tape (4).

10. A lithium battery, characterized in that: Comprising the battery cell as claimed in claim 9.

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