Battery and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery and a battery pack, which comprise a shell with a hollow structure with an opening; the cover plate and the shell are welded to form a welding seam at the joint of the cover plate and the shell, the cover plate and the shell define a containing space, a connecting boss is formed on the edge of the cover plate, a positioning protrusion is formed on the inner side of the connecting boss of the cover plate, the connecting boss abuts against the end face, where the opening is formed, of the shell, and the positioning protrusion extends into the shell from the opening; the pole group is arranged in the accommodating space; and the connecting sheet is arranged between the pole group and the cover plate, and the edge of the connecting sheet is inserted between the inner wall of the shell and the positioning bulge. When the cover plate is assembled, the cover plate is positioned by the connecting piece, the edge of the connecting piece is positioned between the inner wall of the shell and the positioning bulge, and the connecting boss is propped against the end surface of the shell for welding, so that the cover plate is prevented from being rubbed with the shell in the assembly process, and the cover plate and the shell are prevented from being damaged; the production quality of the battery is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to batteries and battery packs. Background Art

[0002] The battery generally includes an internal structure and an external structure. The internal structure mainly includes a cell pole group, and the external structure mainly includes a cell cover and a cell shell. The cell shell provides a space for the cell pole group. The cell cover and the cell shell are welded together to form a closed space, thereby forming a complete battery structure. However, in the prior art, the cover is directly inserted into the shell, and the cover and the shell are matched with zero clearance. When the cover is assembled, it is easy to scratch the shell, causing damage to the cover and the shell, affecting the quality of the battery. Utility Model Content

[0003] In view of this, the utility model provides a battery and a battery pack to solve the problem in the prior art that the cover plate is easily scratched against the shell when assembled, causing damage to the cover plate and the shell, thereby affecting the quality of the battery.

[0004] In the first aspect, the utility model provides a battery, comprising: a shell, which is a hollow structure with an opening; a cover plate, arranged corresponding to the opening, the cover plate and the shell are welded to form a weld at the connection between the cover plate and the shell, the cover plate and the shell are enclosed to form a accommodating space, the edge of the cover plate forms a connecting boss, the cover plate forms a positioning boss on the inner side of the connecting boss, the connecting boss and the shell form an end face of the opening, and the positioning boss extends from the opening into the shell; a pole group, arranged in the accommodating space; a connecting sheet, arranged between the pole group and the cover plate, the edge of the connecting sheet is inserted between the inner wall of the shell and the positioning boss.

[0005] Beneficial effect: When assembling the cover plate, the cover plate is positioned using the connecting piece so that the edge of the connecting piece is located between the inner wall of the shell and the positioning protrusion, and the connecting boss is abutted against the end face of the shell for welding, thereby avoiding scratches between the cover plate and the shell during assembly, avoiding damage to the cover plate and the shell, and ensuring the production quality of the battery.

[0006] In an optional embodiment, the distance t between the inner wall of the shell and the positioning protrusion is the same as the thickness of the connecting piece.

[0007] Beneficial effect: the two opposite sides of the edge of the connecting piece are respectively in contact with the inner wall of the shell and the side wall of the positioning protrusion, thereby improving the positioning effect of the cover plate.

[0008] In an optional implementation, the distance t between the inner wall of the shell and the positioning protrusion is in the range of 0.2 mm≤t≤0.5 mm.

[0009] In an optional implementation, the thickness of the connecting boss is a, satisfying 0.4mm≤a≤0.6mm; and / or the wall thickness of the shell is b, satisfying 0.3mm≤b≤0.6mm.

[0010] Beneficial effects: while ensuring the structural strength and welding strength of the cover plate, the cover plate thickness is prevented from being too large to affect the energy density of the battery; while ensuring the structural strength and welding strength of the shell, the shell wall thickness is prevented from being too large to affect the energy density of the battery.

[0011] In an optional implementation, along the axial direction of the shell, the weld width of the weld is w, and the weld width ratio is defined as x=w / a, satisfying 1≤x≤2.75.

[0012] Beneficial effect: while ensuring the welding strength and welding air tightness of the shell and the cover plate, the welding yield rate is improved.

[0013] In an optional implementation, the weld width w of the weld is in the range of 0.6 mm ≤ w ≤ 1.1 mm.

[0014] Beneficial effect: while ensuring the welding strength and welding air tightness of the shell and the cover plate, the welding yield rate is improved.

[0015] In an optional implementation, along the radial direction of the shell, the penetration depth of the weld is d, and the penetration ratio is defined as y=d / b, satisfying 0.375≤y≤1.

[0016] Beneficial effect: While ensuring the welding strength and welding air tightness of the shell and the cover plate, it prevents the weld from penetrating the shell and burning the pole group.

[0017] In an optional implementation, the penetration depth d of the weld is in the range of 0.3 mm ≤ d ≤ 0.5 mm.

[0018] Beneficial effect: While ensuring the welding strength and welding air tightness of the shell and the cover plate, it prevents the weld from penetrating the shell and burning the pole group.

[0019] In an optional embodiment, the weld forms a first protrusion on the outer peripheral surfaces of the shell and the cover plate, and along the radial direction of the shell, the height of the first protrusion is c1, satisfying c1<0.15mm; and / or, the weld forms a second protrusion on a side of the cover plate away from the shell, and along the axial direction of the shell, the height of the second protrusion is c2, satisfying c2<0.15mm.

[0020] Beneficial effect: When attaching the insulating protection sheet to the periphery of the battery, the insulating protection sheet is prevented from warping, thereby ensuring the flatness of the battery surface.

[0021] In a second aspect, the utility model also provides a battery pack, comprising the above-mentioned battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is a schematic diagram of the exploded structure of a battery according to an embodiment of the present utility model;

[0024] Figure 2 A top view of a battery according to an embodiment of the present utility model;

[0025] Figure 3 for Figure 2 Sectional view in the AA direction;

[0026] Figure 4 for Figure 3 A partial enlarged schematic diagram of B in the middle;

[0027] Figure 5 It is a schematic diagram of the welding structure of the shell and the cover plate of the embodiment of the utility model.

[0028] Description of reference numerals:

[0029] 1. Shell; 11. Guide angle; 2. Cover plate; 21. Connecting boss; 22. Positioning protrusion; 3. Welding seam; 31. First protrusion; 32. Second protrusion; 4. Pole group; 5. Connecting piece. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0031] Combine the following Figures 1 to 5 , describing an embodiment of the utility model.

[0032] According to an embodiment of the utility model, on the one hand, a battery is provided, comprising: a shell 1, a cover plate 2, a pole group 4 and a connecting piece 5. The shell 1 is a hollow structure with an opening, the cover plate 2 is arranged corresponding to the opening, the cover plate 2 is welded to the shell 1 to form a weld 3 at the connection between the cover plate 2 and the shell 1, and the cover plate 2 and the shell 1 are enclosed to form a receiving space. The edge of the cover plate 2 forms a connecting boss 21, and the cover plate 2 forms a positioning boss 22 on the inner side of the connecting boss 21. The connecting boss 21 is arranged in abutment with the end face of the opening formed by the shell 1, and the positioning boss 22 extends from the opening into the shell 1. The pole group 4 is arranged in the receiving space, and the connecting piece 5 is arranged between the pole group 4 and the cover plate 2, and the edge of the connecting piece 5 is inserted between the inner wall of the shell 1 and the positioning boss 22.

[0033] When assembling the cover plate 2, the cover plate 2 is positioned using the connecting piece 5 so that the edge of the connecting piece 5 is located between the inner wall of the shell 1 and the positioning protrusion 22, and the connecting boss 21 is abutted against the end face of the shell 1 for welding, thereby avoiding scratches between the cover plate 2 and the shell 1 during assembly, avoiding damage to the cover plate 2 and the shell 1, and ensuring the production quality of the battery.

[0034] It is worth noting that if Figure 4 and Figure 5 As shown, the inner wall of the shell 1 forms a guide angle 11 near the opening so that the opening is expanded relative to the interior of the shell 1 to facilitate the insertion of the pole group 4 into the shell and prevent the pole group 4 from being scratched by the shell 1 when entering the shell.

[0035] In one embodiment, Figure 4 As shown, the distance t between the inner wall of the housing 1 and the positioning protrusion 22 is the same as the thickness of the connecting piece 5. The two opposite sides of the edge of the connecting piece 5 are respectively in contact with the inner wall of the housing 1 and the side wall of the positioning protrusion 22, thereby improving the positioning effect of the cover plate 2.

[0036] In one embodiment, Figure 4 As shown, the distance t between the inner wall of the housing 1 and the positioning protrusion 22 is in the range of 0.2 mm ≤ t ≤ 0.5 mm. That is, the thickness of the connecting sheet 5 is 0.2 mm to 0.5 mm.

[0037] It is worth noting that if t<0.2mm, that is, the thickness of the connecting sheet 5 is less than 0.2mm, the connecting sheet 5 is too thin, the structural strength of the connecting sheet 5 itself is low, and it is easy to deform or even break, and the positioning effect of the connecting sheet 5 on the cover plate 2 is affected; if t>0.5mm, that is, the thickness of the connecting sheet 5 is greater than 0.5mm, the connecting sheet 5 is too thick, the cost is high, and the internal volume of the battery is increased, resulting in a decrease in the energy density of the battery.

[0038] In one embodiment, Figure 4As shown, the thickness of the connecting boss 21 is a, which satisfies 0.4 mm ≤ a ≤ 0.6 mm. While ensuring the structural strength and welding strength of the cover plate 2, the thickness of the cover plate 2 is prevented from being too large to affect the energy density of the battery.

[0039] It is worth noting that if a is less than 0.4 mm, the connecting boss 21 is too thin, the structural strength of the cover plate 2 itself is low, and it is not easy to weld the connecting boss 21 to the shell 1, and the welding strength is difficult to ensure; if a is greater than 0.6 mm, the connecting boss 21 is too thick, resulting in a decrease in the energy density of the battery.

[0040] In one embodiment, Figure 4 As shown, the wall thickness of the shell 1 is b, which satisfies 0.3 mm ≤ b ≤ 0.6 mm. While ensuring the structural strength and welding strength of the shell 1, the wall thickness of the shell 1 is prevented from being too large to affect the energy density of the battery.

[0041] It is worth noting that if b is less than 0.3 mm, the shell 1 is too thin, the structural strength of the shell 1 itself is low, and it is not easy to weld the shell 1 to the cover plate 2, and the welding strength is not easy to ensure; if b is greater than 0.6 mm, the shell 1 is too thick, resulting in a decrease in the energy density of the battery.

[0042] In one embodiment, Figure 5 As shown, along the axial direction of the shell 1, the weld width of the weld 3 is w, and the weld width ratio is defined as x=w / a, which satisfies 1≤x≤2.75. While ensuring the welding strength and welding air tightness of the shell 1 and the cover plate 2, the welding yield rate is improved.

[0043] In one embodiment, Figure 5 As shown, the range of the weld width w of the weld 3 is 0.6 mm ≤ w ≤ 1.1 mm, thereby improving the welding yield rate while ensuring the welding strength and welding air tightness of the housing 1 and the cover plate 2.

[0044] It is worth noting that if the weld width and / or the weld width ratio are too small, the welding strength is insufficient, the welding sealing is poor, and there is a risk of leakage; if the weld width and / or the weld width ratio are too large, the weld 3 exceeds the thickness of the connecting boss 21 too much, and it is easy to have undesirable phenomena such as melt beads, explosion points, and pinholes.

[0045] In one embodiment, Figure 5 As shown, along the radial direction of the shell 1, the penetration depth of the weld 3 is d, and the penetration ratio is defined as y=d / b, which satisfies 0.375≤y≤1. While ensuring the welding strength and welding airtightness of the shell 1 and the cover plate 2, the weld 3 is prevented from penetrating the shell 1 and burning the pole group 4.

[0046] In one embodiment, Figure 5As shown, the range of the penetration depth d of the weld 3 is 0.3 mm ≤ d ≤ 0.5 mm. While ensuring the welding strength and welding air tightness of the shell 1 and the cover plate 2, the weld 3 is prevented from penetrating the shell 1 and burning the electrode group 4.

[0047] It is worth noting that if the penetration depth and / or penetration depth ratio are too small, the welding strength is insufficient, the welding sealing is poor, and there is a risk of leakage; if the penetration depth and / or penetration depth ratio are too large, the weld 3 penetrates the shell 1 and easily causes burns to the pole group 4.

[0048] In one embodiment, Figure 5 As shown, the weld 3 forms a first protrusion 31 on the outer circumference of the shell 1 and the cover plate 2. The height of the first protrusion 31 along the radial direction of the shell 1 is c1, and c1 < 0.15 mm is satisfied. When attaching the insulating protection sheet to the outer circumference of the battery, the insulating protection sheet is prevented from warping to ensure the flatness of the battery surface.

[0049] In one embodiment, Figure 5 As shown, the weld 3 forms a second protrusion 32 on the side of the cover plate 2 away from the housing 1. The height of the second protrusion 32 along the axial direction of the housing 1 is c2, and c2 < 0.15 mm is satisfied. When attaching the insulating protective sheet to the outer surface of the cover plate 2, the insulating protective sheet is prevented from warping to ensure the flatness of the battery surface.

[0050] It should be noted that, in this embodiment, by constraining and limiting the welding matching dimensions of the shell 1 and the cover plate 2, the welding yield of the shell 1 and the cover plate 2 is improved, the material cost is reduced, and the production efficiency is improved.

[0051] The following tests were conducted on batteries with different welding fitting sizes, and the test results of the embodiment and comparative example are shown in Table 1 and Table 2. The embodiment refers to a battery that meets the requirements of the embodiment, and the comparative example refers to a battery that does not meet the requirements of the embodiment.

[0052] Table 1 Example test results

[0053]

[0054] Table 2 Comparative Example Test Results

[0055]

[0056]

[0057] It can be seen from Table 1 that in Examples 1 to 13, the weld width w satisfies 0.6 mm ≤ w ≤ 1.1 mm, and the weld depth d satisfies 0.3 mm ≤ d ≤ 0.5 mm. Therefore, the strength requirements and airtightness requirements of the battery weld 3 of Examples 1 to 13 are met.

[0058] It can be seen from Table 2 that in Comparative Examples 1 to 6, the values ​​of the weld width w are all less than 0.6 mm, and the values ​​of the weld depth d are all less than 0.3 mm. Although the batteries of Comparative Examples 1 to 6 meet the airtight performance requirements, they do not meet the strength requirements of the weld 3.

[0059] It can be seen from Table 2 that in Comparative Examples 7 to 12, the values ​​of the weld width w are all greater than 1.1 mm, and the values ​​of the weld depth d are all greater than 0.5 mm. The batteries of Comparative Examples 7 to 12 neither meet the strength requirements of the battery weld 3 nor meet the airtight performance requirements.

[0060] It is worth noting that the strength and air tightness of the battery weld 3 are tested, including the following steps: after the shell 1 and the cover plate 2 are welded, the battery is placed in a special inspection fixture and helium inspected by a helium mass spectrometer. If the battery leakage rate is ≤9.9×10 -8 Pa·m 3 / s is OK, if the battery leakage rate is > 9.9×10 -8 Pa·m 3 / s is NG; after the helium test is completed, the opening pressure of the explosion-proof valve is tested, and the inside of the shell 1 is pressurized until the explosion-proof valve opens. If the weld 3 is damaged before the explosion-proof valve opens, there will be an obvious leakage sound, and the pressure inside the shell 1 will rise very slowly or cannot rise.

[0061] According to an embodiment of the present invention, on the other hand, a battery pack is provided, comprising the above-mentioned battery.

[0062] Although the embodiments of the present invention are described in conjunction with 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, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery, characterized in that: include: A shell, wherein the shell is a hollow structure with an opening; A cover plate is arranged corresponding to the opening, the cover plate is welded to the shell to form a weld at the connection between the cover plate and the shell, the cover plate and the shell are enclosed to form a receiving space, the edge of the cover plate forms a connecting boss, the cover plate forms a positioning boss on the inner side of the connecting boss, the connecting boss is abutted against the end surface of the shell forming the opening, and the positioning boss extends from the opening into the shell; A pole group is arranged in the accommodation space; A connecting piece is arranged between the pole group and the cover plate, and an edge of the connecting piece is inserted between the inner wall of the shell and the positioning protrusion.

2. The battery according to claim 1, characterized in that The distance t between the inner wall of the housing and the positioning protrusion is the same as the thickness of the connecting sheet.

3. The battery according to claim 2, characterized in that The distance t between the inner wall of the shell and the positioning protrusion is in the range of 0.2 mm≤t≤0.5 mm.

4. The battery according to any one of claims 1 to 3, characterized in that The thickness of the connecting boss is a, satisfying 0.4 mm ≤ a ≤ 0.6 mm; and / or, The wall thickness of the shell is b, satisfying 0.3mm≤b≤0.6mm.

5. The battery according to claim 4, characterized in that Along the axial direction of the shell, the weld width of the weld is w, and the weld width ratio is defined as x=w / a, satisfying 1≤x≤2.

75.

6. The battery according to claim 5, characterized in that The weld width w of the weld is in the range of 0.6 mm ≤ w ≤ 1.1 mm.

7. The battery according to claim 4, characterized in that Along the radial direction of the shell, the penetration depth of the weld is d, and the penetration ratio is defined as y=d / b, satisfying 0.375≤y≤1.

8. The battery according to claim 7, characterized in that The penetration depth d of the weld is in the range of 0.3 mm ≤ d ≤ 0.5 mm.

9. The battery according to any one of claims 1 to 3, characterized in that The weld forms a first protrusion on the outer circumferential surface of the shell and the cover plate, and along the radial direction of the shell, the height of the first protrusion is c1, and c1<0.15mm is satisfied; and / or, The weld forms a second protrusion on a side of the cover plate away from the shell. Along the axial direction of the shell, the height of the second protrusion is c2, satisfying c2<0.15mm.

10. A battery pack, characterized in that: A battery comprising the battery according to any one of claims 1 to 9.

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