Battery cover plate, battery and battery pack

Abstract

The present invention relates to the technical field of batteries, and discloses a battery cover plate, a battery and a battery pack, the battery cover plate comprises a cover plate body provided with an anti-explosion valve hole; the cover plate body comprises a main body; the boss is connected with one side face of the main body, the anti-explosion valve hole penetrates through the main body and the boss at the same time, one face, away from the main body, of the boss is concavely arranged towards the main body to form a partition groove, and the partition groove is circumferentially arranged around the anti-explosion valve hole; and the anti-explosion valve is connected with the main body and is arranged corresponding to the anti-explosion valve hole. The boss is arranged on the periphery of the anti-explosion valve hole, the structural strength of the position, corresponding to the anti-explosion valve, of the battery cover plate is improved, the partition groove is formed in the periphery of the anti-explosion valve hole, conduction of welding heat in the welding process of the battery cover plate and the shell can be effectively reduced, therefore, the heat influence of the welding heat on the anti-explosion valve is reduced, and the service life of the battery cover plate is prolonged. The cracking risk of the explosion-proof valve is greatly reduced, and the production efficiency and the safety of the battery are ensured.

Description

Technical Field

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

[0002] Lithium-ion batteries are currently widely used in various fields such as transportation power supply, electric energy storage power supply, new energy energy storage power supply, aerospace and military industry due to their large capacity, high operating voltage, strong charge retention ability and long cycle life.

[0003] The battery usually includes a battery cover, a battery shell and an electrode group. The battery cover and the battery shell are welded to form a closed space to protect the electrode group. An explosion-proof valve is usually set on the battery cover. Its main function is to release pressure and exhaust. That is, when the battery has thermal runaway due to mechanical impact, abnormal short circuit of internal lap joint, etc., the internal high-temperature and high-pressure gas is released in a directional manner, thereby improving the safety performance of the battery pack.

[0004] In order to improve the space utilization of the entire battery pack and increase the battery pack capacity, the thickness of the battery cell is gradually reduced, which leads to the limitation of the size of the explosion-proof valve. The distance between the explosion-proof valve and the edge of the cover plate is getting smaller and smaller, resulting in a great thermal impact on the explosion-proof valve when the cover plate and the shell are welded at the periphery, which leads to frequent cracking of the explosion-proof valve due to thermal deformation, seriously affecting the battery production efficiency and battery safety. Summary of the invention

[0005] In view of this, the present invention provides a battery cover, a battery and a battery pack to solve the problem in the prior art that the explosion-proof valve frequently cracks due to thermal deformation, which seriously affects the battery production efficiency and battery safety.

[0006] In the first aspect, the present invention provides a battery cover, including a cover body, which is provided with an explosion-proof valve hole; the cover body includes: a main body; a boss connected to a side surface of the main body, the explosion-proof valve hole penetrates the main body and the boss at the same time, and a partition groove is formed by a side of the boss away from the main body toward the main body, and the partition groove is circumferentially arranged around the explosion-proof valve hole; an explosion-proof valve is connected to the main body and arranged corresponding to the explosion-proof valve hole.

[0007] Beneficial effect: By arranging a boss on the periphery of the explosion-proof valve hole, the structural strength of the battery cover corresponding to the explosion-proof valve is increased, and by arranging a partition groove on the periphery of the explosion-proof valve hole, the conduction of welding heat during the welding process of the battery cover and the shell can be effectively reduced, thereby reducing the thermal effect of the welding heat on the explosion-proof valve, greatly reducing the risk of cracking of the explosion-proof valve, and ensuring the production efficiency and safety of the battery.

[0008] In an optional implementation, along the thickness direction of the battery cover plate, the thickness of the boss is a, satisfying 0.3 mm ≤ a ≤ 0.5 mm.

[0009] Beneficial effect: While ensuring that the structural strength of the battery cover at the explosion-proof valve hole is effectively increased, the internal space occupied by the battery is reduced to avoid affecting the battery capacity.

[0010] In an optional implementation, the width of the partition groove is b, satisfying 0.5 mm ≤ b ≤ 1 mm.

[0011] Beneficial effect: While ensuring the heat insulation effect of the partition, it avoids affecting the structural strength of the battery cover.

[0012] In an optional implementation, the minimum distance between a groove wall on one side of the partition groove close to the explosion-proof valve hole and a hole wall of the explosion-proof valve hole is c, satisfying c≥1 mm.

[0013] Beneficial effect: Make c ≥ 1mm to ensure the heat insulation effect of the partition.

[0014] In an optional embodiment, the explosion-proof valve is provided with a bursting notch, and the bursting notch is opened inwardly from the outer surface of the explosion-proof valve or opened outwardly from the inner surface of the explosion-proof valve.

[0015] In an optional embodiment, along the thickness direction of the battery cover plate, the distance between the bottom of the partition groove and the side surface of the explosion-proof valve where the bursting mark is located is d, and d≥0.5mm.

[0016] Beneficial effect: Make d ≥ 0.5 mm to ensure the heat insulation effect of the partition.

[0017] In an optional embodiment, the explosion-proof valve hole is a stepped hole so that the hole wall of the explosion-proof valve hole forms a step structure, and the outer peripheral edge of the explosion-proof valve is welded to the step structure; and / or, the main body includes a connecting part and a guide part, and the connecting part and the guide part are connected and arranged along the thickness direction of the battery cover plate, and the outer periphery of the connecting part extends out of the outer periphery of the guide part, so that the guide part extends into the shell and the part of the connecting part extending out of the guide part is connected to the end face of the shell, and the boss is connected to a side of the guide part away from the connecting part.

[0018] In an optional embodiment, the area of ​​the explosion-proof valve hole on the side of the boss away from the main body accounts for less than 0.5; and / or, on the side of the boss away from the main body, the minimum distance between the edge of the explosion-proof valve hole and the edge of the boss is greater than 3 mm.

[0019] Beneficial effect: By limiting the relationship between the explosion-proof valve hole and the side of the boss away from the main body, the enhancement effect of the boss on the structural strength of the main body is ensured.

[0020] In a second aspect, the present invention further provides a battery, comprising the above-mentioned battery cover.

[0021] In a third aspect, the present invention further 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 present invention 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 present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic structural diagram of a battery cover at one angle according to an embodiment of the present invention;

[0024] Figure 2 for Figure 1 A schematic diagram of the exploded structure of the battery cover shown in another angle;

[0025] Figure 3 for Figure 1 A top view of the battery cover and the housing after being matched;

[0026] Figure 4 for Figure 3 Sectional view of AA in the middle;

[0027] Figure 5 It is a schematic structural diagram of an explosion-proof valve hole on a side of a boss away from a main body according to an embodiment of the present invention.

[0028] Description of reference numerals:

[0029] 1. Main body; 11. Explosion-proof valve hole; 111. First hole body; 112. Second hole body; 12. Step structure; 13. Connecting part; 14. Guide part; 2. Boss; 3. Groove; 4. Explosion-proof valve; 41. Explosion notch; 5. Shell. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the 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 creative work are within the scope of protection of the present invention.

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

[0032] According to an embodiment of the present invention, on the one hand, a battery cover is provided, including a cover body, which is provided with an explosion-proof valve hole 11; the cover body includes: a main body 1, a boss 2 and an explosion-proof valve 4. The boss 2 is connected to one side of the main body 1, and the explosion-proof valve hole 11 is set through the main body 1 and the boss 2 at the same time. A partition groove 3 is formed by the side of the boss 2 away from the main body 1 and facing the main body 1, and the partition groove 3 is circumferentially arranged around the explosion-proof valve hole 11. The explosion-proof valve 4 is connected to the main body 1 and is arranged corresponding to the explosion-proof valve hole 11.

[0033] The battery cover of the present embodiment increases the structural strength of the battery cover corresponding to the explosion-proof valve 4 by arranging a boss 2 on the periphery of the explosion-proof valve hole 11, and effectively reduces the conduction of welding heat during the welding process between the battery cover and the shell 5 by arranging a partition groove 3 on the periphery of the explosion-proof valve hole 11, thereby reducing the thermal influence of the welding heat on the explosion-proof valve 4, greatly reducing the risk of cracking of the explosion-proof valve 4, and ensuring the production efficiency and safety of the battery.

[0034] It is worth mentioning that by providing the boss 2, the structural strength of the battery cover corresponding to the explosion-proof valve hole 11 is increased. Therefore, when welding heat is generated during the welding process of the battery cover and the shell 5, the battery cover is not easily thermally deformed at the position of the explosion-proof valve hole 11, thereby avoiding affecting the explosion-proof valve 4 and reducing the risk of cracking of the explosion-proof valve 4.

[0035] Furthermore, since the thermal conductivity of air is lower than that of metal, by providing the partition groove 3, the welding heat during the welding process of the battery cover and the shell 5 can be effectively prevented from being transferred to the explosion-proof valve 4, thereby effectively reducing the thermal deformation of the explosion-proof valve 4, and further reducing the risk of cracking of the explosion-proof valve 4.

[0036] In summary, under the dual effects of the boss 2 and the partition groove 3, the risk of cracking of the explosion-proof valve 4 can be effectively reduced, the production efficiency of the battery can be improved, and the safety of the battery can be improved.

[0037] Please note that Figure 4, the boss 2 is connected to the inner side of the main body 1, and the inner side of the main body 1 is the side of the main body 1 close to the shell 5 when the battery cover and the shell 5 are assembled. Similarly, the side of the boss 2 away from the main body 1 is the inner side of the boss 2, and further, the outer side of the boss 2 is connected to the inner side of the main body 1. Therefore, the recessed direction of the partition 3 is from the inner side of the boss 2 to the outer side of the main body 1.

[0038] In one embodiment, Figure 4 As shown, along the thickness direction of the battery cover, the thickness of the boss 2 is a, which satisfies 0.3mm≤a≤0.5mm. This arrangement effectively increases the structural strength of the battery cover at the explosion-proof valve hole 11 while reducing the occupation of the internal space of the battery to avoid affecting the battery capacity.

[0039] It is worth noting that if a is less than 0.3 mm, the thickness of the boss 2 is too small, and the effect of increasing the structural strength of the battery cover is not obvious. It is still easy to be thermally deformed under the influence of the welding heat during the welding process of the battery cover and the shell 5, resulting in an impact on the explosion-proof valve 4; and when the battery cover is processed and formed, the position of the explosion-proof valve hole 11 is greatly affected by the mold, and the thickness of the boss 2 is too small to be easily formed. If a>0.5 mm, the battery cover occupies a larger internal space of the shell 5, which will affect the capacity of the battery.

[0040] In one embodiment, Figure 4 As shown, the width of the partition 3 is b, which satisfies 0.5 mm ≤ b ≤ 1 mm. This arrangement ensures the heat insulation effect of the partition 3 while avoiding affecting the structural strength of the battery cover.

[0041] It is worth noting that if b is less than 0.5 mm, the width of the partition 3 is too small, and it is not easy to prevent the conduction of heat through the partition 3. A large part of the welding heat during the welding process of the battery cover and the shell 5 is still transferred to the explosion-proof valve 4, which is still easy to cause thermal deformation of the explosion-proof valve 4. If b is greater than 1 mm, the width of the partition 3 is too large, which will greatly weaken the structural strength of the battery cover, and thus the overall structural strength of the battery cannot be guaranteed.

[0042] In one embodiment, Figure 4 As shown, the minimum distance between the groove wall of the partition groove 3 close to the explosion-proof valve hole 11 and the hole wall of the explosion-proof valve hole 11 is c, and c≥1mm is satisfied. When c≥1mm, the heat insulation effect of the partition groove 3 is guaranteed.

[0043] It is worth mentioning that please refer to Figures 1 to 3 The explosion-proof valve hole 11 and the explosion-proof valve 4 are both oblong structures (i.e., runway-shaped). At this time, the partition groove 3 is also opened in an oblong shape and arranged around the explosion-proof valve hole 11. The distance between the groove wall on one side of the partition groove 3 close to the explosion-proof valve hole 11 and the hole wall of the explosion-proof valve hole 11 is c.

[0044] Of course, in other alternative embodiments, the explosion-proof valve 4, the explosion-proof valve hole 11 and the partition groove 3 can be in other shapes, such as square, circular, elliptical, etc.

[0045] In one embodiment, Figure 4 As shown, the explosion-proof valve 4 is provided with a bursting notch 41, which is opened inwardly from the outer surface of the explosion-proof valve 4 or opened outwardly from the inner surface of the explosion-proof valve 4. By providing the bursting notch 41, when the battery needs to be vented, the explosion-proof valve 4 can be exploded at the remaining thickness of the bursting notch 41.

[0046] In one embodiment, along the thickness direction of the battery cover, the distance d between the bottom of the partition groove 3 and the side surface of the explosion-proof valve 4 where the bursting notch 41 is located satisfies d≥0.5mm. When d≥0.5mm, the heat insulation effect of the partition groove 3 is ensured.

[0047] Specifically, in this embodiment, if Figure 4 As shown, the bursting notch 41 is opened inwardly from the outer surface of the explosion-proof valve 4. Therefore, the distance between the bottom of the partition groove 3 and the outer surface of the explosion-proof valve 4 corresponding to the opening position of the bursting notch 41 is d.

[0048] It is worth noting that if d is less than 0.5 mm, the welding heat during the welding process between the battery cover and the shell 5 is still easily transferred to the position of the bursting notch 41 of the explosion-proof valve 4 through the main body 1, and thus is still likely to affect the explosion-proof valve 4.

[0049] Please note that Figure 4 Along the thickness direction of the battery cover, the partition groove 3 penetrates the boss 2 and extends into the main body 1 , and forms a groove bottom of the partition groove 3 in the main body 1 .

[0050] In one embodiment, Figure 5 As shown, the area of ​​the explosion-proof valve hole 11 on the side of the boss 2 away from the main body 1 accounts for less than 0.5. Figure 5 The area of ​​the explosion-proof valve hole 11 on the side of the boss 2 away from the main body 1 is S1. Along the length direction of the battery cover, the length of the side of the boss 2 away from the main body 1 is L1, and the width of the side of the boss 2 away from the main body 1 is L2. Therefore, S1 / (L1×L2)<0.5.

[0051] It should be noted that the side of the boss 2 away from the main body 1 may also be other regular or irregular shapes, such as circular, elliptical, oblong, etc.

[0052] In one embodiment, Figure 5As shown, on the side of the boss 2 away from the main body 1, the minimum distance between the edge of the explosion-proof valve hole 11 and the edge of the boss 2 is greater than 3mm. Figure 5 The distances between the edge of the explosion-proof valve hole 11 and the four sides of the boss 2 away from the main body 1 are e, f, g, and h respectively. Therefore, e>3mm, f>3mm, g>3mm, and h>3mm.

[0053] In one embodiment, Figure 4 As shown, the explosion-proof valve hole 11 is a stepped hole, so that the hole wall of the explosion-proof valve hole 11 forms a step structure 12, and the outer peripheral edge of the explosion-proof valve 4 is welded to the step structure 12. Specifically, as Figure 4 As shown, the explosion-proof valve hole 11 includes a first hole body 111 and a second hole body 112. The first hole body 111 and the second hole body 112 are connected along the thickness direction of the battery cover plate. The first hole body 111 is located on the outside of the second hole body 112. The opening size of the first hole body 111 is smaller than the opening size of the second hole body 112 to form a step structure 12 at the connection between the first hole body 111 and the second hole body 112.

[0054] In one embodiment, Figure 4 As shown, the main body 1 includes a connecting portion 13 and a guiding portion 14, and the connecting portion 13 and the guiding portion 14 are connected and arranged along the thickness direction of the battery cover. The outer periphery of the connecting portion 13 extends out of the outer periphery of the guiding portion 14, so that the guiding portion 14 extends into the shell 5 and the part of the connecting portion 13 extending out of the guiding portion 14 is connected to the end surface of the shell 5, and the boss 2 is connected to a side of the guiding portion 14 away from the connecting portion 13.

[0055] The explosion-proof valve 4 after welding the battery cover plate and the shell 5 with different values ​​of the minimum distance c between the groove wall on one side of the partition groove 3 close to the explosion-proof valve hole 11 and the hole wall of the explosion-proof valve hole 11 is tested. The test results are shown in Table 1.

[0056] Table 1 Test results of explosion-proof valve 4 after welding of battery cover and shell 5 with different values ​​of dimension c

[0057]

[0058] It can be seen from Table 1 that in Comparative Examples 1 to 7, when the value of c is less than 1 mm, the thermal insulation effect of the partition groove 3 is not obvious, and the cracking ratio of the explosion-proof valve 4 is still relatively high. In Examples 1 to 5, when the value of c is not less than 1 mm, the thermal insulation effect of the partition groove 3 is better, and the cracking ratio of the explosion-proof valve 4 is significantly reduced.

[0059] The explosion-proof valve 4 after welding the battery cover plate and the housing 5 with different values ​​of the width b of the partition 3 is tested below. The test results are shown in Table 2.

[0060] Table 2 Test results of explosion-proof valve 4 after welding of battery cover and shell 5 with different values ​​of dimension b

[0061]

[0062] It can be seen from Table 2 that in Comparative Examples 8 to 14, when the value of b is less than 0.5 mm, the thermal insulation effect of the partition groove 3 is not obvious, and the cracking ratio of the explosion-proof valve 4 is still relatively high. In Examples 6 to 10, when the value of b is not less than 0.5 mm, the thermal insulation effect of the partition groove 3 is better, and the cracking ratio of the explosion-proof valve 4 is significantly reduced.

[0063] The following tests are conducted on the explosion-proof valve 4 after welding the battery cover plate and the shell 5 with different values ​​of the distance d between the bottom of the partition groove 3 and the side of the bursting notch 41 close to the outer surface of the explosion-proof valve 4. The test results are shown in Table 3.

[0064] Table 3 Test results of explosion-proof valve 4 after welding of battery cover and shell 5 with different values ​​of dimension d

[0065]

[0066] It can be seen from Table 3 that in Comparative Examples 15 to 21, when the value of d is less than 0.5 mm, the thermal insulation effect of the partition groove 3 is not obvious, and the cracking ratio of the explosion-proof valve 4 is still relatively high. In Examples 11 to 15, when the value of d is not less than 0.5 mm, the thermal insulation effect of the partition groove 3 is better, and the cracking ratio of the explosion-proof valve 4 is significantly reduced.

[0067] The battery cover of the present embodiment is designed with a boss 2 at the position of the explosion-proof valve hole 11 of the main body 1, and a partition groove 3 with a reasonable size is added, which can effectively reduce the thermal impact of the welding heat during the welding process of the battery cover and the shell 5 on the explosion-proof valve 4, greatly reduce the cracking ratio of the explosion-proof valve 4 caused by the welding of the battery cover and the shell 5, significantly improve the production yield of the battery process, and reduce the risk of explosion of the explosion-proof valve 4 due to thermal deformation caused by the heat of welding during the battery process and in the later stage.

[0068] According to an embodiment of the present invention, on the other hand, a battery is provided, comprising the above-mentioned battery cover.

[0069] In one embodiment, Figure 4 As shown, the battery further includes a shell 5, at least one end of the shell 5 is open, and the battery cover is connected to the shell 5 and blocks the opening.

[0070] According to an embodiment of the present invention, in yet another aspect, a battery pack is provided, comprising the above-mentioned battery.

[0071] Although the embodiments of the present invention have been 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 cover, characterized in that: It includes a cover plate body, which is provided with an explosion-proof valve hole; the cover plate body includes: main body; A boss is connected to a side surface of the main body, the explosion-proof valve hole is set through the main body and the boss at the same time, a partition groove is formed by a side of the boss away from the main body toward the main body, and the partition groove is circumferentially arranged around the explosion-proof valve hole; An explosion-proof valve is connected to the main body and is arranged corresponding to the explosion-proof valve hole.

2. The battery cover according to claim 1, characterized in that: Along the thickness direction of the battery cover plate, the thickness of the boss is a, satisfying 0.3mm≤a≤0.5mm.

3. The battery cover according to claim 1 or 2, characterized in that: The width of the partition groove is b, which satisfies 0.5mm≤b≤1mm.

4. The battery cover according to claim 1 or 2, characterized in that: The minimum distance between the groove wall on one side of the partition groove close to the explosion-proof valve hole and the hole wall of the explosion-proof valve hole is c, and c≥1mm.

5. The battery cover according to claim 1 or 2, characterized in that: The explosion-proof valve is provided with a bursting notch, and the bursting notch is opened inwardly from the outer surface of the explosion-proof valve or opened outwardly from the inner surface of the explosion-proof valve.

6. The battery cover according to claim 5, characterized in that: Along the thickness direction of the battery cover plate, the distance between the bottom of the partition groove and the side surface of the explosion-proof valve where the bursting notch is located is d, and d≥0.5mm.

7. The battery cover according to claim 1 or 2, characterized in that: The explosion-proof valve hole is a stepped hole, so that the hole wall of the explosion-proof valve hole forms a step structure, and the outer peripheral edge of the explosion-proof valve is welded to the step structure; and / or, The main body includes a connecting portion and a guiding portion, and the connecting portion and the guiding portion are connected and arranged along the thickness direction of the battery cover plate. The outer periphery of the connecting portion extends out of the outer periphery of the guiding portion, so that the guiding portion extends into the shell and the part of the connecting portion extending out of the guiding portion is connected to the end surface of the shell, and the boss is connected to a side of the guiding portion away from the connecting portion.

8. The battery cover according to claim 1 or 2, characterized in that: The area of ​​the explosion-proof valve hole on the side of the boss away from the main body accounts for less than 0.5; and / or, On a side of the boss away from the main body, a minimum distance between an edge of the explosion-proof valve hole and an edge of the boss is greater than 3 mm.

9. A battery, characterized in that: A battery cover comprising the battery cover according to any one of claims 1 to 8.

10. A battery pack, characterized in that: A battery comprising the battery of claim 9.

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