Tab assembly of battery cell, battery cell and battery pack

Abstract

The utility model relates to a tab assembly of a battery cell, the battery cell and a battery pack. The tab assembly comprises a connecting piece, a lead and a lead, wherein the connecting piece is an electric conductor; the tab glue is attached to the surface of the connecting piece, the tab glue comprises a glue body and a glue overflowing area, and the glue body can be filled into the glue overflowing area in the bonding process of the tab glue. The tab assembly provided by the utility model can have a good bonding effect with the packaging film, so that the safety of the battery cell is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery packaging, and more specifically, to a tab assembly of a battery cell, a battery cell and a battery pack. Background Art

[0002] In the packaging process of the battery cell, the connecting piece of the tab usually needs to be hot-melt compressed and bonded to the PP layer of the aluminum-plastic film through the tab glue at high temperature and pressure to achieve the sealing and leakage-proof function of the battery cell. In the prior art, in order to ensure the bonding strength, the compression amount of the tab glue needs to be increased, but excessive compression is prone to overflow of glue, resulting in a short circuit between the shell and the tab, affecting the safety of the battery cell. Utility Model Content

[0003] One purpose of the utility model is to provide a new technical solution for a battery cell tab assembly, a battery cell and a battery pack.

[0004] According to a first aspect of the utility model, a tab assembly of a battery cell is provided, comprising:

[0005] A connecting piece, wherein the connecting piece is a conductor;

[0006] The ear glue is attached to the surface of the connecting piece, and the ear glue comprises a colloid and an overflow glue area. During the bonding process of the ear glue, the colloid can fill into the overflow glue area.

[0007] Optionally, the glue overflow area includes a plurality of glue overflow holes.

[0008] Optionally, the glue overflow hole is a blind hole, and the blind hole faces a side away from the connecting sheet.

[0009] Optionally, the depth of the blind hole is less than or equal to 1 / 2 of the thickness of the tab glue.

[0010] Optionally, the total area of ​​the plurality of glue overflow holes accounts for 30% to 40% of the total area of ​​the tab glue.

[0011] Optionally, the tab glue is bonded to the connecting sheet through the colloid, so that the peel strength between the tab glue and the connecting sheet is greater than 10 N / mm.

[0012] Optionally, the connecting piece is used to connect to the pole core of the battery, and the end of the connecting piece close to the pole core is a root, and the end away from the pole core is a head, and the head is provided with rounded corners.

[0013] Optionally, a portion of the tab glue on the connecting sheet is projected beyond a side edge of the connecting sheet, and the side edge is provided with a bevel, and a size of the bevel is 1 / 3 to 1 / 2 of the thickness of the connecting sheet.

[0014] Optionally, the distance from the root to the head is the total height of the connecting piece, and the distance between the tab glue and the root is equal to 1 / 4 to 1 / 3 of the total height of the connecting piece.

[0015] Optionally, the colloid includes a melting layer and a high temperature resistant layer, the high temperature resistant layer is attached to the connecting sheet, the overflow area is located on the melting layer, and the melting point of the high temperature resistant layer is higher than that of the melting layer.

[0016] Optionally, the tab glue is provided with two layers, which are respectively attached to the upper surface and the lower surface of the connecting sheet.

[0017] According to a second aspect of the present invention, a battery cell is provided, comprising: a pole core and the pole tab assembly described in the first aspect, wherein the pole tab assembly is connected to an end of the pole core.

[0018] Optionally, the battery core further comprises a packaging film, which is coated on the outer side of the electrode core and bonded to the connecting sheet via the ear glue.

[0019] According to a third aspect of the utility model, a battery pack is provided, comprising the battery cell described in the second aspect.

[0020] A technical effect of the utility model is:

[0021] The pole ear assembly provided by the utility model provides a glue overflow area on the pole ear glue, so that in the process of bonding the connecting piece to the aluminum-plastic film of the battery cell, the colloid of the pole ear glue and the glue overflow part of the aluminum-plastic film glue can be filled into the glue overflow area first, which not only ensures the bonding strength, but also reduces the amount of glue overflow, reduces the risk of short circuit between the shell and the pole ear, and improves the safety of the battery cell.

[0022] Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present utility model and, together with the description, are used to explain the principles of the present utility model.

[0024] Figure 1 It is a schematic diagram of a tab assembly provided by the utility model.

[0025] Figure 2 yes Figure 1 A partial enlarged view of point A in the middle.

[0026] Figure 3 This is a front view of a tab assembly provided by the utility model.

[0027] Figure 4 yes Figure 3 A side view of a tab assembly is provided.

[0028] Figure 5 yes Figure 3 The BB cross-section of the tab assembly is provided.

[0029] Figure 6 yes Figure 5 A partial enlarged view of point C in the middle.

[0030] Figure 7 It is a partial structural schematic diagram of a battery core provided by the utility model.

[0031] Figure 8 yes Figure 6 Schematic diagram of the cross section at point D.

[0032] Fig. 9 It is a schematic diagram of bonding the ear glue and the aluminum-plastic film PP glue layer provided by the utility model.

[0033] Description of reference numerals:

[0034] 1. Connecting piece; 11. Root; 12. Head; 13. Side edge; 14. Fillet; 15. Bevel; 2. Ear glue; 21. Overflow glue area; 22. Colloid; 3. Pole core; 4. Packaging film; 41. PP glue layer; 42. Aluminum structure layer; 43. Protective layer. DETAILED DESCRIPTION

[0035] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0036] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present invention, its application, or uses.

[0037] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0038] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0039] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0040] like Figures 1 to 9 As shown, according to the first aspect of the utility model, a tab assembly of a battery cell is provided, comprising: a connecting sheet 1 and a tab glue 2, wherein the connecting sheet 1 is a conductor; the tab glue 2 is attached to the surface of the connecting sheet 1, and the tab glue 2 comprises a colloid 22 and a glue overflow area 21, and during the bonding process of the tab glue 2, the colloid 22 can be filled into the glue overflow area 21.

[0041] Specifically, in this embodiment, the provided tab assembly can be connected to the pole core 3, and then the tab glue 2 is pasted to the packaging film 4 that packages the pole core 3 to package the battery cell. Among them, the connecting piece 1 can be a conductor of metal material, and its root 11 is connected to the foil of the pole core 3, and the other end (i.e., the head 12) is used for PACK assembly welding, and the tab glue 2 is usually arranged in a partial area between the root 11 and the head 12 of the connecting piece 1, and after being bonded to the packaging film 4, the entire battery cell is sealed.

[0042] In practical applications, the packaging (bonding) strength of the tab glue 2 and the packaging film 4 affects the sealing performance of the entire battery cell. The packaging film 4 usually includes a PP glue layer 41 located on the inside, an aluminum structure layer 42 arranged on the outside of the PP glue layer 41, and a protective layer 43 arranged on the outside of the aluminum structure layer 42. During the packaging process, the tab glue 2 and the PP glue layer 41 of the packaging film 4 can be hot-melt compressed and bonded by high temperature and pressure, thereby achieving the sealing and leakage-proof function of the battery cell. Among them, when the tab assembly is used as the positive electrode of the battery cell, the material of the connecting sheet 1 can be selected from aluminum alloy with an aluminum content of >99.5%, and when used as the negative electrode, the material can be selected from copper-plated nickel.

[0043] The present application sets a glue overflow area 21 on the ear glue 2, referring to Figure 1 to Figure 2 ,as well as Figure 6 , so that in the process of packaging the tab assembly through the tab glue 2 and the packaging film 4, the excess overflowed colloid 22 can be filled into the overflow area 21 first, reducing the overflow of the glue outside the seal during the bonding process, and preventing the battery shell short circuit and other abnormalities caused by excessive overflow of glue, thereby improving the safety of the battery. Among them, the overflow area 21 is usually formed at different positions of the colloid 22, and the filling of the colloid can be achieved by extrusion or high temperature.

[0044] In addition, in the above-mentioned sealing process, by setting the overflow area 21 on the ear glue 2, the PP glue layer 41 of the packaging film 4 can also be preferentially filled into the overflow area 21 after melting, thereby constructing a three-dimensional curved colloid bonding surface with the ear glue 2, referring to Fig. 9 Compared with the two-dimensional planar bonding surface in the prior art, the bonding area has been significantly improved, thereby improving the sealing strength and further improving the safety performance of the battery cell.

[0045] Alternatively, if Figures 1 to 6As shown, the glue overflow area 21 includes a plurality of glue overflow holes.

[0046] Specifically, in this embodiment, the glue overflow area 21 is configured as a plurality of evenly arranged glue overflow holes, and the plurality of glue overflow holes can cover the surface of the tab glue 2, so that the glue overflow at each bonding surface during the bonding process can be filled into the glue overflow holes nearby, thereby improving the uniformity of the bonding strength of the bonding surface, and further improving the sealing strength between the tab glue 2 and the sealing film. Among them, the plurality of glue overflow holes can be arranged in an array, and their shapes can be circular, polygonal, etc., and the formation of the glue overflow holes can be by mold stamping, and the present utility model does not limit this.

[0047] Alternatively, if Figure 6 As shown, the glue overflow hole is a blind hole and the blind hole faces a side away from the connecting sheet 1 .

[0048] Specifically, in actual applications, if there are too many overflow holes, the amount of overflow glue of the colloid 22 will not be enough to fill each overflow hole, thereby affecting the bonding surface connection and causing the sealing strength to decrease. The present application designs multiple overflow holes as blind holes facing the side away from the connecting piece 1, so that during the bonding process, the overflow holes can be evenly distributed on the surface of the ear glue 2, and the overflow glue can fill each overflow hole as much as possible, so as to ensure the bonding strength and improve the sealing performance of the battery cell. In addition, the blind hole is designed on the side away from the connecting piece 1, that is, during the actual sealing process, the blind hole is directly in contact with the PP glue layer 41 of the packaging film 4, so that the overflow glue of the PP glue layer 41 flows into the overflow hole to construct a three-dimensional bonding surface.

[0049] Optionally, refer to Figure 6 The depth of the blind hole is less than or equal to 1 / 2 of the thickness of the tab glue 2.

[0050] Specifically, in practical applications, the glue capacity of the overflow glue area 21 can be adjusted by adjusting the depth of the blind hole. Normally, the sealing strength is highest when the thickness of the glue layer is 60% to 70% of the total thickness before compression. The depth of the blind hole is designed to be less than or equal to 1 / 2 of the thickness of the ear glue 2, so that each overflow glue hole can be fully filled during the sealing process to improve the sealing strength.

[0051] In one embodiment, the total area of ​​the plurality of overflow holes can be designed to account for 30% to 40% of the total area of ​​the tab glue 2, that is, the width of the overflow holes can be adjusted to meet the requirement of being fully filled.

[0052] In addition, the peel strength between the colloid 22 of the tab glue 2 and the connecting sheet 1 is greater than 10 N / mm, so as to meet the bonding strength between the tab glue 2 and the connecting sheet 1, avoid peeling between the tab glue 2 and the connecting sheet 1, and further improve the sealing performance of the battery cell.

[0053] Alternatively, if Figures 7 and 8 As shown, the connecting piece 1 is used to connect with the pole core 3 of the battery, and the end of the connecting piece 1 close to the pole core 3 is a root 11, and the end away from the pole core 3 is a head 12, and the head 12 is provided with a rounded corner 14. The setting of the rounded corner 14 can prevent the edge of the connecting piece 1 from cutting the pole ear glue 2 and affecting the bonding strength of the pole ear glue 2.

[0054] Alternatively, if Figures 1 to 6 As shown, the portion of the tab glue 2 on the connecting sheet 1 is projected beyond the side edge 13 of the connecting sheet 1 , and the side edge 13 is provided with a bevel 15 , and the dimension c of the bevel 15 is 1 / 3 to 1 / 2 of the thickness of the connecting sheet 1 .

[0055] Specifically, the setting of the bevel angle 15 enables a smooth transition of the tab glue 2 at the side edge 13 of the connecting piece 1. At the same time, when the tab glue 2 is set on both the upper and lower surfaces of the connecting piece 1, the bonding gap between the upper and lower adhesive layers is reduced to avoid the gap being too large to affect the sealing performance. Among them, the size of the bevel angle 15 that is too large or too small will lead to the bonding effect at the gap. Designing it to be 1 / 3 to 1 / 2 of the thickness of the connecting piece 1 can meet the gap width requirement. Among them, the size of the bevel angle 15 refers to the size c of the bevel angle 15 in the thickness direction of the connecting piece 1, refer to Figure 4 and Figure 6 .

[0056] Alternatively, if Figure 3 to Figure 4 As shown, the distance from the root 11 to the head 12 is the total height h of the connecting piece 1 , and the distance a between the tab glue 2 and the root 11 is equal to 1 / 4 to 1 / 3 of the total height h of the connecting piece 1 .

[0057] Specifically, in practical applications, the root 11 of the connecting sheet 1 is used for welding with the foil of the pole core 3. Under the premise of ensuring the welding effect, the distance between the pole ear glue 2 and the pole ear root 11 can be minimized to improve the space utilization of the battery cell. In addition, the larger the layout area of ​​the pole ear glue 2 on the connecting sheet 1, the better the bonding effect.

[0058] The present application designs the distance between the ear glue 2 and the root 11 to be equal to 1 / 4 to 1 / 3 of the total height of the connecting piece 1. At the same time, the width b of the ear glue 2 in the height direction of the connecting piece 1 can be designed to be 6 mm to 15 mm to meet the welding effect of the root 11 of the connecting piece 1 and the foil and the bonding strength of the ear glue 2.

[0059] Optionally, the colloid 22 includes a melting layer and a high temperature resistant layer, the high temperature resistant layer is attached to the connecting sheet 1, the overflow area 21 is located on the melting layer, and the melting point of the high temperature resistant layer is higher than that of the melting layer.

[0060] Specifically, in this embodiment, the colloid 22 of the ear glue 2 is provided with a melting layer and a high temperature resistant layer, and the melting point of the high temperature resistant layer is higher than that of the melting layer, so that during the packaging process of the battery cell, the melting layer can be melted and compressed at high temperature to fill the overflow area 21, playing the role of packaging melting and sealing, while the state of the high temperature resistant layer does not change, so as to ensure the bonding strength between the colloid 22 of the ear glue 2 and the connecting sheet 1 and prevent the problem of shell short circuit caused by colloid melting, thereby further improving the safety performance of the battery cell. Among them, the melting layer can be made of PP (polypropylene) material, and the high temperature resistant layer can be made of PET (polyethylene terephthalate) material.

[0061] Alternatively, if Figures 4 to 8 As shown, the tab glue 2 is provided with two layers, which are respectively attached to the upper surface and the lower surface of the connecting piece 1. The tab glue 2 with the overflow area 21 provided in this embodiment is provided on both sides of the connecting piece 1, so that the sealing and safety of the entire battery core are higher.

[0062] According to the second aspect of the present invention, Figures 7 to 9 As shown, a battery cell is provided, comprising: a pole core 3, a packaging film 4 and the pole ear assembly described in the first aspect, wherein the pole ear assembly is connected to the end of the pole core 3, the packaging film 4 is coated on the outside of the pole core 3, and is bonded to the connecting sheet 1 through the pole ear glue 2.

[0063] Specifically, in this embodiment, the pole core 3 assembly is welded to the end of the pole core 3 through the connecting piece 1, and the packaging film 4 is sealed on the outside of the pole core 3 and the pole ear assembly. Due to the setting of the overflow area 21 of the pole ear glue 2, the sealing strength between the connecting piece 1 and the packaging film 4 is higher, which improves the sealing performance and safety insulation performance of the battery. Among them, the packaging film 4 includes a PP glue layer 41 located on the inside, an aluminum structure layer 42 arranged on the outside of the PP glue layer 41, and a nylon protective layer 43 arranged on the outside of the aluminum structure layer 42.

[0064] According to the third aspect of the utility model, a battery pack is provided, comprising the battery cell according to the second aspect. The battery pack composed of the battery cell provided by the second aspect of the utility model has higher safety.

[0065] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0066] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A tab assembly of a battery cell, characterized in that: include: A connecting piece (1), wherein the connecting piece (1) is a conductor; The ear glue (2) is attached to the surface of the connecting sheet (1), and the ear glue (2) comprises a glue (22) and an overflow glue area (21). During the bonding process of the ear glue (2), the glue (22) can fill the overflow glue area (21).

2. The tab assembly according to claim 1, characterized in that: The glue overflow area (21) comprises a plurality of glue overflow holes.

3. The tab assembly according to claim 2, characterized in that: The glue overflow hole is a blind hole, and the blind hole faces a side away from the connecting piece (1).

4. The tab assembly according to claim 3, characterized in that: The depth of the blind hole is less than or equal to 1 / 2 of the thickness of the tab glue (2).

5. The tab assembly according to any one of claims 2 to 4, characterized in that: The total area of ​​the plurality of glue overflow holes accounts for 30% to 40% of the total area of ​​the tab glue (2).

6. The tab assembly according to claim 1, characterized in that: The tab glue (2) is bonded to the connecting sheet (1) via the colloid (22), so that the peel strength between the tab glue (2) and the connecting sheet (1) is greater than 10 N / mm.

7. The tab assembly according to claim 1, characterized in that: The connecting piece (1) is used to connect to the pole core (3) of a battery, and the end of the connecting piece (1) close to the pole core (3) is a root (11), and the end away from the pole core (3) is a head (12), and the head (12) is provided with a rounded corner (14).

8. The tab assembly according to claim 7, characterized in that: The portion of the tab glue (2) on the connecting sheet (1) is projected beyond the side edge (13) of the connecting sheet (1), and the side edge (13) is provided with a bevel (15), and the size of the bevel (15) is 1 / 3 to 1 / 2 of the thickness of the connecting sheet (1).

9. The tab assembly according to claim 7, characterized in that: The distance from the root (11) to the head (12) is the total height of the connecting piece (1), and the distance between the tab glue (2) and the root (11) is equal to 1 / 4 to 1 / 3 of the total height of the connecting piece (1).

10. The tab assembly according to claim 1, characterized in that: The colloid (22) comprises a melting layer and a high temperature resistant layer, the high temperature resistant layer is attached to the connecting sheet (1), the overflowing glue area (21) is located on the melting layer, and the melting point of the high temperature resistant layer is higher than that of the melting layer.

11. The tab assembly according to claim 1, characterized in that: The ear glue (2) is provided with two layers, which are respectively attached to the upper surface and the lower surface of the connecting sheet (1).

12. A battery cell, characterized in that: It comprises a pole core (3) and a pole lug assembly according to any one of claims 1 to 11, wherein the pole lug assembly is connected to the end of the pole core (3).

13. The battery cell according to claim 12, characterized in that: It also comprises a packaging film (4), wherein the packaging film (4) is coated on the outer side of the pole core (3) and is bonded to the connecting sheet (1) via the pole ear glue (2).

14. A battery pack, characterized in that: Comprising the battery cell according to claim 12 or 13.

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