Cover plate, battery cell and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a cover plate, a battery cell and a battery pack, and the cover plate comprises a cover plate body, a first insulating part, a pole, a sealing part and a second insulating part. According to the cover plate, the boss surrounding the outer edge of the pole hole is arranged on the surface of one side of the cover plate body, the local thickness of the cover plate body is increased due to the arrangement of the boss, the face, facing the inner side of the cover plate, of the boss is closer to the end face of the short-edge protruding part, and therefore the distance between the face, facing the bottom plate, of the parallel part and the end face of the short-edge protruding part is shortened; by arranging the thinner bottom plate, one surface, facing the inner side of the cover plate, of the bottom plate can be flush with the end surface of the short-edge protruding part or one surface, facing the inner side of the cover plate, of the bottom plate is inwards protruded out of the end surface of the short-edge protruding part, so that the welding of the tab and the bottom plate is facilitated. The height of the boss is the thinned thickness of the bottom plate, the thickness of the pole bottom plate is reduced due to the arrangement of the boss, and the material cost of the pole is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a cover plate, a battery cell and a battery pack. Background Art

[0002] The cover plate includes a cover plate body, a pole and a first insulating member, among other components. The pole includes a base plate and a column portion provided on the base plate, and the column portion passes through the first insulating member and the cover plate body. After the cover plate is assembled, the pole tabs of the pole group are welded to the pole base plate. The first insulating member is provided on the inner side of the cover plate body. The two ends of the first insulating member in the width direction are provided with a short side protrusion and a long side protrusion extending toward the inner side of the cover plate. The length of the long side protrusion extending toward the inner side of the cover plate body is greater than the length of the short side protrusion extending toward the inner side of the cover plate body. In order to facilitate the welding of the pole tab and the base plate, under normal circumstances, the surface of the pole base plate facing the inner side of the cover plate needs to be flush with the end face of the short side protrusion, or the surface of the pole base plate facing the inner side of the cover plate needs to protrude beyond the end face of the short side protrusion, which results in a larger thickness of the base plate, thereby increasing the material cost of the pole. Summary of the Invention

[0003] In view of this, the present invention provides a cover plate, a battery cell and a battery pack to solve the problem in the prior art that the bottom plate of the pole of the cover plate is thick, which leads to an increase in the cost of the pole material.

[0004] In a first aspect, the present invention provides a cover plate, comprising:

[0005] The cover body is provided with a pole hole, and a boss is provided on one side surface of the cover body surrounding the outer edge of the pole hole;

[0006] a first insulating member, wherein a long-side protrusion and a short-side protrusion are respectively provided on both sides of a surface of the first insulating member facing the inner side of the cover plate in a width direction, the long-side protrusion being longer than the short-side protrusion along the thickness direction of the cover plate;

[0007] A pole, comprising a base plate and a column portion provided on the base plate, wherein the column portion passes through the first insulating member and the cover plate body; a surface of the base plate facing the inner side of the cover plate is flush with an end surface of the short-side protrusion, or a surface of the base plate facing the inner side of the cover plate protrudes beyond the end surface of the short-side protrusion;

[0008] The sealing member comprises a vertical portion and a parallel portion arranged on one side of the vertical portion, wherein the vertical portion and the parallel portion are sleeved on the column portion; two surfaces of the parallel portion respectively abut against the boss and the bottom plate.

[0009] Beneficial Effects: This structure of the cover plate has a boss surrounding the outer edge of the pole hole on one side surface of the cover plate body. The parallel portion of the seal abuts against the surface of the boss facing the inner side of the cover plate, and the bottom plate abuts against the surface of the parallel portion facing the inner side of the cover plate. The provision of the boss increases the local thickness of the cover plate body, making the side of the boss facing the inner side of the cover plate closer to the end face of the short-side protrusion, thereby shortening the distance between the side of the parallel portion facing the bottom plate and the end face of the short-side protrusion, thereby reducing the thickness of the bottom plate. Providing a thinner bottom plate can make the side of the bottom plate facing the inner side of the cover plate flush with the end face of the short-side protrusion or make the side of the bottom plate facing the inner side of the cover plate protrude inwardly from the end face of the short-side protrusion, thereby facilitating welding of the tab and the bottom plate. The height of the boss is the thickness of the thinned bottom plate. The provision of the boss reduces the thickness of the pole bottom plate, reducing the material cost of the pole.

[0010] In an optional embodiment, the boss is formed by stamping; the height of the boss protruding from the surface of the cover body is h2, 0.5mm≤h2≤1mm.

[0011] Beneficial effect: This arrangement can not only ensure the thinning effect of the base plate, but also facilitate the stamping and forming of the boss.

[0012] In an optional embodiment, the compression amount of the parallel portion along the thickness direction of the cover plate is h3, and along the width direction of the cover plate, the width of the contact area between the boss located on one side of the pole hole and the parallel portion is W, 0.5mm≤h3≤0.8mm, 0.7mm≤W≤1.2mm, and the circumferential outer edge of the boss is located outside the circumferential outer edge of the parallel portion.

[0013] Beneficial Effects: This allows the parallel portion to be fully compressed while also ensuring the contact area between the parallel portion and the boss, thereby ensuring a seal between the sealing ring and the boss, preventing air leakage from the cover plate and ensuring the tightness of the cover plate. The circumferential outer edge of the boss is located outside the circumferential outer edge of the parallel portion, ensuring that the boss is fully pressed against the parallel portion. The boss can effectively compress the parallel portion, thereby ensuring a seal at the boss.

[0014] In an optional embodiment, along the width direction of the cover plate body, the width of the pole hole is D, the width of the boss is W3, and (W3-D) / 2≥0.7 mm.

[0015] Beneficial effect: This arrangement can ensure the lower limit of the width of the boss on the side of the pole hole, thereby ensuring the contact area between the boss and the parallel portion, and further ensuring the sealing effect at the boss.

[0016] In an optional embodiment, a groove opposite to the boss is provided on the surface of the cover body facing the outer side of the cover plate, and the depth of the groove is h1; along the width direction of the cover body, the width of the groove is W1, the width of the pole hole is D, and the width of the boss is W3, h1*((W1-D) / 2)≥1.2*(h2*((W3-D) / 2)).

[0017] Beneficial effect: This arrangement makes the cross-sectional area of ​​the side boss of the pole hole greater than or equal to 1.2 times the theoretical design value of the cross-sectional area of ​​the side boss of the pole hole, thereby ensuring the actual value of the cross-sectional area of ​​the stamped boss, thereby ensuring the thinning effect of the boss on the bottom plate and the sealing of the boss, and also ensuring the assembly and fit of the various components of the cover plate.

[0018] In an optional embodiment, the depth of the groove is h1, 0.3mm≤h1≤1mm.

[0019] In an optional embodiment, along the width direction of the cover plate body, the width of the groove is W1, the width of the second insulating member is W2, the width of the pole hole is D, and D+0.8mm≤W1≤W2-0.4mm.

[0020] In a second aspect, the present invention further provides a battery cell comprising a housing and a cover plate as described above, wherein the housing has an opening and the cover plate is disposed over the opening. The battery cell including the cover plate has the same technical effects as the cover plate and will not be further described here.

[0021] In an optional embodiment, the battery cell includes a blade battery cell, both sides of the shell are open, and the cover plate includes a positive cover plate and a negative cover plate, and the positive cover plate and the negative cover plate are respectively arranged on the openings on both sides of the shell.

[0022] In a third aspect, the present invention further provides a battery pack comprising the aforementioned battery cell. The battery pack includes a cover plate, which has the same technical effects as the cover plate and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 is a cross-sectional view of a cover plate according to an embodiment of the present invention;

[0025] Figure 2 is a cross-sectional view of a cover plate according to an embodiment of the present invention;

[0026] Figure 3 is a cross-sectional view of a cover plate according to an embodiment of the present invention;

[0027] Figure 4 This is a cross-sectional view of a cover plate according to an embodiment of the present invention.

[0028] Description of reference numerals:

[0029] 1. Cover plate body; 11. Boss; 12. Groove; 2. First insulating member; 21. Long side protrusion; 22. Short side protrusion; 3. Pole; 31. Bottom plate; 32. Column; 4. Sealing member; 41. Vertical portion; 42. Parallel portion; 5. Second insulating member. DETAILED DESCRIPTION

[0030] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0031] The following combination Figures 1 to 4 , describing embodiments of the present invention.

[0032] According to an embodiment of the present invention, on one hand, a cover is provided, including a cover body 1 , a first insulating member 2 , a pole 3 , a sealing member 4 and a second insulating member 5 .

[0033] Among them, a pole hole is provided on the cover body 1, and a boss 11 is provided on one side surface of the cover body 1 around the outer edge of the pole hole. The first insulating member 2 is respectively provided with a long side protrusion 21 and a short side protrusion 22 protruding toward the inner side of the cover in the width direction on both sides of the surface facing the inner side of the cover. Along the thickness direction of the cover, the protruding length of the long side protrusion is greater than the protruding length of the short side protrusion; the pole 3 includes a bottom plate 31 and a columnar portion 32 provided on the bottom plate 31, and the columnar portion 32 passes through the first insulating member 2 and the cover body 1; one side of the bottom plate 31 facing the inner side of the cover is flush with the end face of the short side protrusion, or one side of the bottom plate 31 facing the inner side of the cover protrudes beyond the end face of the short side protrusion; the sealing member 4 includes a vertical portion 41 and a parallel portion 42 provided on one side of the vertical portion 41, and the vertical portion 41 and the parallel portion 42 are sleeved on the columnar portion 32; the two sides of the parallel portion 42 respectively abut the boss 11 and the bottom plate 31.

[0034] The cover plate of this structure is provided with a boss 11 surrounding the outer edge of the pole hole on one side surface of the cover plate body 1, the parallel portion 42 of the seal 4 abuts against the surface of the boss 11 facing the inner side of the cover plate, and the bottom plate 31 abuts against the surface of the parallel portion 42 facing the inner side of the cover plate. The provision of the boss 11 increases the local thickness of the cover plate body 1, so that the side of the boss 11 facing the inner side of the cover plate is closer to the end face of the short side protrusion 22, thereby shortening the distance between the side of the parallel portion 42 facing the bottom plate 31 and the end face of the short side protrusion 22, thereby reducing the thickness of the bottom plate 31. Providing a thinner bottom plate 31 can make the side of the bottom plate 31 facing the inner side of the cover plate flush with the end face of the short side protrusion 22 or make the side of the bottom plate 31 facing the inner side of the cover plate protrude inwardly from the end face of the short side protrusion 22, thereby facilitating the welding of the pole ear and the bottom plate 31. The height of the boss 11 is equal to the thickness of the bottom plate 31 reduced by the thickness of the boss 11 . The arrangement of the boss 11 reduces the thickness of the bottom plate 31 of the pole 3 , thereby reducing the material cost of the pole 3 .

[0035] The negative electrode column is generally made of copper, which is relatively expensive. Reducing the thickness of the bottom plate 31 can effectively reduce the material cost of the negative electrode column.

[0036] In some optional embodiments, such as Figure 2 As shown, the boss 11 is formed by stamping; the height of the boss 11 protruding from the surface of the cover body 1 is h2, 0.5mm≤h2≤1mm. During stamping, the punch acts on the first surface of the cover body 1 facing the outside of the cover, and the first surface is concave to form a groove 12. Correspondingly, the second surface of the cover body 1 facing the inside of the cover protrudes to form the boss 11. If h2 is too small, the local thickness of the cover body 1 does not increase significantly, so that the thickness of the bottom plate 31 is not significantly thinned; if h2 is too large, it is difficult to form the boss 11 by stamping. 0.5mm≤h2≤1mm, this setting can not only ensure the thinning effect of the bottom plate 31, but also facilitate the stamping of the boss 11.

[0037] In some optional embodiments, such as Figure 3As shown, the compression amount of the parallel portion 42 along the thickness direction of the cover plate is h3. Along the width direction of the cover plate, the width of the contact area between the boss 11 on one side of the pole hole and the parallel portion 42 is W, 0.5mm≤h3≤0.8mm, 0.7mm≤W≤1.2mm, and the circumferential outer edge of the boss 11 is located outside the circumferential outer edge of the parallel portion 42. h3≥0.5mm, which ensures that the compression amount of the parallel portion 42 along the height direction of the boss 11 is W≥0.7mm, which ensures the contact width between the parallel portion 42 and the boss 11 is h3≥0.5mm and W≥0.7mm. This ensures that the parallel portion 42 can be fully compressed, while also ensuring the contact area between the parallel portion 42 and the boss 11, thereby ensuring the sealing effect between the sealing ring and the boss 11, preventing air leakage in the cover plate, and ensuring the sealing performance of the cover plate. The circumferential outer edge of the boss 11 is located outside the circumferential outer edge of the parallel portion 42 , so that the boss 11 can be completely pressed onto the parallel portion 42 . The boss 11 can effectively compress the parallel portion 42 , thereby ensuring the sealing effect at the boss 11 .

[0038] In some optional embodiments, such as Figure 4 As shown, along the width direction of the cover body 1, the width of the pole hole is D, the width of the boss 11 is W3, (W3-D) / 2≥0.7mm, (W3-D) / 2 is the width of the pole hole side boss 11, and the width of the pole hole side boss 11 is greater than or equal to 0.7mm. This setting can ensure the lower limit of the width of the pole hole side boss 11, thereby ensuring the contact area between the boss 11 and the parallel portion 42, and further ensuring the sealing effect at the boss 11.

[0039] Cover plates with different W3, D, W, and h3 were designed, and air tightness tests were conducted on the covers to observe whether they leaked. The test results are shown in Table 1.

[0040] Table 1

[0041]

[0042] As shown in Examples 1 to 8 in Table 1, when the dimensional parameters of the cover plate satisfy 0.5mm≤h3≤0.8mm, 0.7mm≤W≤1.2mm, and (W3-D) / 2≥0.7mm, the cover plate has good sealing performance and does not leak during the air tightness test. As shown in Comparative Examples 1 and 2, when W is less than 0.7mm and (W1-D) / 2 is less than 0.7mm, the contact area between the parallel portion 42 of the seal 4 and the boss 11 is insufficient, the cover plate has poor sealing performance, and the cover plate leaks during the air tightness test. As shown in Comparative Examples 3 and 4, when h3 is less than 0.5mm, the parallel portion 42 has insufficient compression, the cover plate has poor sealing performance, and the cover plate leaks during the air tightness test.

[0043] like Figure 2 As shown, in some embodiments, a groove 12 is provided on the surface of the cover body 1 facing the outside of the cover plate, opposite to the boss 11, and the depth of the groove 12 is h1. Along the width direction of the cover body 1, the width of the groove 12 is W1, the width of the pole hole is D, and the width of the boss 11 is W3, and h1*((W1-D) / 2)≥1.2*(h2*(W3-D) / 2). Because the groove 12 and the boss 11 are formed by stamping, affected by the stamping process, after actual stamping, the height of the boss 11 is less than the depth of the groove 12. In order to ensure the sealing effect at the boss 11 and the thinning effect on the bottom plate 31, it is necessary to ensure the height h2 and width of the boss 11 on the side of the pole hole, that is, the cross-sectional area of ​​the boss 11 needs to be ensured. After the boss 11 is stamped, the cross-sectional area of ​​the boss 11 is smaller than the cross-sectional area of ​​the groove 12. In order to ensure the cross-sectional area of ​​the boss 11, the cross-sectional area of ​​the groove 12 needs to be increased accordingly. h1*((W1-D) / 2) is the actual value of the cross-sectional area of ​​the pole hole side groove 12, h2*((W3-D) / 2) is the theoretical design value of the cross-sectional area of ​​the pole hole side boss 11, and h1*((W1-D) / 2)≥1.2*(h2*((W3-D) / 2)). This setting makes the cross-sectional area of ​​the pole hole side boss 11 greater than or equal to 1.2 times the theoretical design value of the cross-sectional area of ​​the pole hole side boss 11, thereby ensuring the actual value of the cross-sectional area of ​​the stamped boss 11, thereby ensuring the thinning effect of the boss 11 on the bottom plate 31 and the sealing at the boss 11, and also ensuring the assembly and fit of the various components of the cover plate.

[0044] Cover plates with different h1, W1, h2, and W3 were designed. h1 and W1 are actual values, while h2 and W3 are theoretical design values. The cover plate body 1 was punched to form a groove 12 and a boss 11. The actual dimensions of the boss 11 were measured. The test results are shown in Table 2.

[0045] Table 2

[0046]

[0047] h1*((W1-D) / 2) is the actual size of the cover plate, and (h2*(W3-D) / 2) is the theoretical design value. As shown in Examples 1 to 8 in Table 2, when h1*((W1-D) / 2) ≥ 1.2*(h2*(W3-D) / 2), the actual size of the boss 11 formed after stamping is greater than or equal to the theoretical value, and the actual size of the convex hull meets the theoretical design value requirements. As shown in Comparative Examples 1 to 4 in Table 2, when h1*((W1-D) / 2) < 1.2*(h2*(W3-D) / 2), the actual size of the boss 11 after stamping is less than the theoretical design values ​​of h2 and W3.

[0048] In some embodiments, as Figure 2 As shown, the depth of the groove 12 is h1, 0.3mm≤h1≤1mm. The cover plate also includes a second insulating member 5, the bottom of the second insulating member 5 is embedded in the groove 12, a rivet block is provided on the second insulating member 5, and the column portion 32 is riveted on the rivet block. The bottom of the second insulating member 5 is clamped in the groove 12 to achieve positioning. If h1 is too small, the positioning effect of the groove 12 is poor. When the pole 3 is riveted, the force on the second insulating member 5 is likely to cause the position of the second insulating member 5 to shift; if h1 is too large, it is difficult to stamp the groove 12. 0.3mm≤h1≤1mm, this can ensure the depth of the groove 12, can ensure the positioning effect of the groove 12 on the second insulating member 5, and also facilitate the stamping of the groove 12.

[0049] In some embodiments, as Figure 3 As shown, along the width direction of the cover body 1, the width of the groove 12 is W1, the width of the second insulating member 5 is W2, and the width of the pole hole is D, D+0.8mm≤W1≤W2-0.4mm. In this way, on the basis of leaving an appropriate assembly offset, it can be ensured that the step on the second insulating member 5 can cover the cover body on the side of the groove 12, and the width of the groove 12 can be prevented from being too large to form a gap between the side wall of the groove 12 and the side wall of the second insulating member 5, which can prevent foreign matter from entering the interior of the cover through the gap.

[0050] According to an embodiment of the present invention, on the other hand, a battery cell is provided, comprising a housing and the cover plate of the above embodiment, wherein the housing is provided with an opening, and the cover plate is provided on the opening.

[0051] In the battery cell of this structure, a boss 11 surrounding the outer edge of the pole hole is provided on one side surface of the cover body 1, the parallel portion 42 of the seal 4 abuts on the surface of the boss 11 facing the inner side of the cover, and the bottom plate 31 abuts on the surface of the parallel portion 42 facing the inner side of the cover. The provision of the boss 11 increases the local thickness of the cover body 1, so that the side of the boss 11 facing the inner side of the cover is closer to the end face of the short side protrusion 22, thereby shortening the distance between the side of the parallel portion 42 facing the bottom plate 31 and the end face of the short side protrusion 22, and thus reducing the thickness of the bottom plate 31. Providing a thinner bottom plate 31 can make the side of the bottom plate 31 facing the inner side of the cover flush with the end face of the short side protrusion 22 or make the side of the bottom plate 31 facing the inner side of the cover protrude inwardly from the end face of the short side protrusion 22, thereby facilitating the welding of the pole ear and the bottom plate 31. The height of the boss 11 is equal to the thickness of the bottom plate 31 reduced by the thickness of the boss 11 . The arrangement of the boss 11 reduces the thickness of the bottom plate 31 of the pole 3 , thereby reducing the material cost of the pole 3 .

[0052] The battery cell includes a blade battery cell, and the housing has two openings on both sides. The cover includes a positive cover and a negative cover, which are respectively arranged on the openings on both sides of the housing. The positive cover is provided with a positive electrode column 3, and the negative cover is provided with a negative electrode column 3.

[0053] According to another aspect of an embodiment of the present invention, a battery pack is provided, comprising the battery cell of the above embodiment.

[0054] In a battery pack of this structure, a boss 11 surrounding the outer edge of the pole hole is provided on one side surface of the cover body 1. The setting of the boss 11 increases the local thickness of the cover body 1 and can reduce the thickness of the bottom plate 31. The height of the boss 11 is the thickness of the thinned bottom plate 31. The setting of the boss 11 reduces the thickness of the bottom plate 31 of the pole 3, thereby reducing the material cost of the pole 3.

[0055] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A cover plate, characterized in that: include: The cover body is provided with a pole hole, and a boss is provided on one side surface of the cover body surrounding the outer edge of the pole hole; a first insulating member, wherein a long-side protrusion and a short-side protrusion are respectively provided on both sides of a surface of the first insulating member facing the inner side of the cover plate in a width direction, the long-side protrusion being longer than the short-side protrusion along the thickness direction of the cover plate; A pole, comprising a base plate and a column portion provided on the base plate, wherein the column portion passes through the first insulating member and the cover plate body; a surface of the base plate facing the inner side of the cover plate is flush with an end surface of the short-side protrusion, or a surface of the base plate facing the inner side of the cover plate protrudes beyond the end surface of the short-side protrusion; The sealing member comprises a vertical portion and a parallel portion arranged on one side of the vertical portion, wherein the vertical portion and the parallel portion are sleeved on the column portion; two surfaces of the parallel portion respectively abut against the boss and the bottom plate.

2. The cover plate according to claim 1, wherein: The boss is formed by stamping; the height of the boss protruding from the surface of the cover body is h2, 0.5mm≤h2≤1mm.

3. The cover plate according to claim 1 or 2, characterized in that: The compression amount of the parallel portion along the thickness direction of the cover plate is h3, and along the width direction of the cover plate, the width of the contact area between the boss located on one side of the pole hole and the parallel portion is W, 0.5mm≤h3≤0.8mm, 0.7mm≤W≤1.2mm, and the circumferential outer edge of the boss is located outside the circumferential outer edge of the parallel portion.

4. The cover plate according to claim 3, wherein: Along the width direction of the cover plate body, the width of the pole hole is D, the width of the boss is W3, and (W3-D) / 2≥0.7mm.

5. The cover plate according to claim 2, wherein: A groove opposite to the boss is provided on the surface of the cover body facing the outer side of the cover plate, and the depth of the groove is h1; along the width direction of the cover body, the width of the groove is W1, the width of the pole hole is D, and the width of the boss is W3, h1*((W1-D) / 2)≥1.2*(h2*((W3-D) / 2)).

6. The cover plate according to claim 5, characterized in that: The depth of the groove is h1, 0.3mm≤h1≤1mm.

7. The cover plate according to claim 5, characterized in that: It also includes a second insulating member, the bottom of which is arranged in the groove. Along the width direction of the cover body, the width of the groove is W1, the width of the second insulating member is W2, and the width of the pole hole is D, D+0.8mm≤W1≤W2-0.4mm.

8. A battery cell, characterized in that: The invention comprises a shell and the cover plate according to any one of claims 1 to 7, wherein the shell is provided with an opening, and the cover plate is arranged on the opening.

9. The battery cell according to claim 8, characterized in that: The battery cell includes a blade battery cell, both sides of the shell are open, and the cover plate includes a positive cover plate and a negative cover plate, and the positive cover plate and the negative cover plate are respectively arranged on the openings on both sides of the shell.

10. A battery pack, characterized in that: Comprising the battery cell according to claim 8 or 9.

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