Anti-explosion valve structure, top cover and battery

Abstract

The utility model belongs to the technical field of lithium batteries, and discloses an anti-explosion valve structure, a top cover and a battery. The anti-explosion valve structure is arranged at a pressure relief opening of the battery and comprises an anti-explosion piece, a nick groove, a buffering convex rib and a welding outer ring are sequentially arranged on the anti-explosion piece from inside to outside in the radial direction, when the internal pressure of the battery exceeds a preset value, the anti-explosion piece is broken from the nick groove, the buffering convex rib is arranged on the surface of the anti-explosion piece in a protruding mode, and the welding outer ring is welded to the anti-explosion piece. The buffering convex rib is arranged in the nick groove in a surrounding manner, and the welding outer ring is configured to be fixedly connected to a top cover plate of the battery in a welding manner. Through the arrangement, residual stress generated in the welding process can firstly pull the buffering convex rib, so that the buffering convex rib deforms to reduce the influence of the residual stress on the nick groove, the buffering convex rib plays a role in buffering pressure and releases the residual stress, and therefore the weak nick groove can be prevented from cracking, and the welding quality is improved. Therefore, the stability of the bursting pressure of the nick groove is kept, and the use safety of the top cover and the battery can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to an explosion-proof valve structure, a top cover and a battery. Background Art

[0002] Lithium batteries refer to batteries that provide power for electric vehicles, plug-in hybrid vehicles and other equipment. Currently, most lithium batteries are packaged in aluminum shells. The explosion-proof valve is a thin-walled valve body on the top cover of the battery. When the internal pressure of the battery exceeds the specified pressure, the explosion-proof valve ruptures, thereby preventing the battery from bursting.

[0003] Existing explosion-proof valves need to be annealed (450℃) to reduce hardness, eliminate residual stress, and stabilize the performance of the explosion-proof valve. However, when the explosion-proof valve is welded to the top cover, due to the high energy of laser welding, the temperature can reach above 600℃, which is equivalent to annealing the explosion-proof valve again for a short time, and residual stress will still be generated, which will cause the explosion-proof valve to deform or even crack, thus seriously affecting the product performance of the explosion-proof valve, causing the bursting pressure to change, and making it impossible for the explosion-proof valve to burst accurately at the specified pressure.

[0004] Based on the above, there is an urgent need for an explosion-proof valve structure, a top cover and a battery to solve the problems existing in the prior art. Utility Model Content

[0005] One purpose of the utility model is to provide an explosion-proof valve structure, which can eliminate the influence of residual stress generated during welding with a top cover sheet on the explosion-proof valve, thereby ensuring the performance of the explosion-proof valve.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] An explosion-proof valve structure is arranged at the pressure relief port of the battery, the explosion-proof valve structure includes an explosion-proof plate, and along the radial direction, the explosion-proof plate is provided with a notched groove, a buffer rib and a welded outer ring from the inside to the outside in sequence, the notched groove is configured so that when the internal pressure of the battery exceeds a preset value, the explosion-proof plate ruptures at the notched groove, the buffer rib is protrudingly arranged on the surface of the explosion-proof plate, the buffer rib is arranged around the notched groove, and the welded outer ring is configured to be fixedly connected to the top cover plate of the battery by welding.

[0008] Preferably, the cross-sectional shape of the buffer rib is U-shaped, M-shaped or wavy.

[0009] Preferably, the cross-sectional shape of the buffer rib is U-shaped.

[0010] Preferably, the buffer rib is protrudingly provided on the top of the explosion-proof disc; and / or the buffer rib is protrudingly provided on the bottom of the explosion-proof disc.

[0011] Preferably, along the radial direction of the explosion-proof plate, a plurality of the buffer ribs are arranged at intervals between the notched groove and the welded outer ring.

[0012] Preferably, the distance between the top of the buffer rib and the surface of the explosion-proof disk is 0.1-0.3 mm.

[0013] Preferably, the side wall inclination angle of the buffer rib is 45°-65°.

[0014] Preferably, the notched groove and the buffer rib are both annular closed structures.

[0015] The explosion-proof valve structure provided by the utility model has the following beneficial effects: on the surface of the explosion-proof disk, a buffer rib is protrudingly provided between the notched groove and the welding outer ring, and the buffer rib is arranged around the notched groove, so that the residual stress generated during the welding process will first pull the buffer rib, causing the buffer rib to deform and reduce the influence of the residual stress on the notched groove, and the buffer rib plays a role of buffering pressure and releasing the residual stress, thereby avoiding the cracking of the weak notched groove, and further maintaining the stability of the bursting pressure of the notched groove.

[0016] The second purpose of the utility model is to provide a top cover, which can improve the production quality and production efficiency of the top cover and ensure the reliability of the use of the top cover.

[0017] To achieve this purpose, the utility model adopts the following technical solutions:

[0018] The top cover comprises a top cover sheet and the explosion-proof valve structure. The top cover sheet is provided with a pressure relief port. The explosion-proof valve structure is sealed and connected to the pressure relief port. The explosion-proof sheet in the explosion-proof valve structure is welded and connected to the top cover sheet.

[0019] The top cover provided by the utility model has the beneficial effects that the top cover is provided with the above-mentioned explosion-proof valve structure. Since the explosion-proof valve structure is provided, the explosion-proof sheet is provided with a buffer rib that can set the interval between the notched groove and the welded outer ring. The buffer rib can absorb and eliminate the stress generated during the annealing process, thereby avoiding the influence of the stress on the notched groove and preventing the notched groove from deforming. Therefore, by connecting the above-mentioned explosion-proof valve structure to the top cover sheet, the production quality and production efficiency of the top cover can be effectively improved, so that the top cover can release the internal gas after the internal pressure of the battery reaches a preset value, thereby ensuring the reliability of the use of the top cover.

[0020] The third object of the utility model is to provide a battery that can improve production efficiency and avoid the situation where the scored groove bursts open before the internal gas pressure of the battery reaches a preset value, thereby ensuring the safety of the battery.

[0021] To achieve this purpose, the utility model adopts the following technical solutions:

[0022] The battery comprises a single cell, a shell and the above-mentioned top cover, wherein the single cell is accommodated in the shell, and the top cover sealing cover is arranged at the opening of the shell.

[0023] The battery provided by the utility model has the following beneficial effects: the battery comprises a single cell, a shell and the above-mentioned top cover, the shell has a receiving cavity, the single cell is located in the receiving cavity, and the top cover sealing cover is arranged at the opening of the shell receiving cavity to seal the single cell. The battery can improve the production efficiency by arranging the above-mentioned top cover, and avoid the situation that the scored groove bursts open before the internal gas pressure of the battery reaches a preset value, thereby ensuring the safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the explosion-proof disk provided by the embodiment of the utility model;

[0025] Figure 2 is a cross-sectional view of an explosion-proof disk provided in an embodiment of the utility model;

[0026] Figure 3 yes Figure 2 A partial enlarged view of point A in the middle.

[0027] In the figure:

[0028] 11. Explosion-proof disk;

[0029] 111. notched groove; 112. welded outer ring; 113. buffer rib; 1131. corner end. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0031] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0034] The existing explosion-proof valve structure needs to be annealed (450°C) to reduce hardness, eliminate residual stress, and stabilize the performance of the explosion-proof valve structure. However, when the explosion-proof valve structure is welded to the top cover sheet, due to the high energy of laser welding, the temperature can reach above 600°C, which is equivalent to annealing the explosion-proof valve again for a short time, and residual stress will still be generated, which will cause the explosion-proof disc 11 in the explosion-proof valve structure to deform or even crack, thereby seriously affecting the product performance of the explosion-proof valve structure, causing the bursting pressure to change, and making it impossible for the explosion-proof disc 11 to burst accurately at the specified pressure.

[0035] When the explosion-proof valve is welded to the top cover sheet, in order to eliminate the influence of residual stress on the explosion-proof valve and ensure the performance of the explosion-proof valve so that the explosion-proof valve can still explode under a specified pressure, the present embodiment provides an explosion-proof valve structure arranged at the pressure relief port of the battery, which can buffer the pressure on the explosion-proof valve during laser welding and avoid cracking at the weak position of the notch.

[0036] like Figure 1As shown, the explosion-proof valve structure includes an explosion-proof disc 11, on which a notch groove 111 is provided. The explosion-proof disc 11 is usually supported by a thinner aluminum alloy sheet, which will rupture under a certain pressure, and the notch groove 111 further reduces the thickness of the explosion-proof disc 11 at this position, so when the internal pressure of the battery exceeds a preset value, the explosion-proof disc 11 will first rupture from the notch groove 111. In addition, the outer edge position of the explosion-proof disc 11 is set as a welding outer ring 112. After the explosion-proof valve structure is installed on the top cover sheet, the explosion-proof valve structure and the top cover sheet are sealed and welded at the welding outer ring 112 of the explosion-proof disc 11 by laser welding. In addition, a buffer rib 113 is protrudingly provided on the surface of the explosion-proof plate 11 between the notched groove 111 and the welding outer ring 112. The buffer rib 113 is arranged around the notched groove 111, so that the residual stress generated during the welding process will first pull the buffer rib 113, causing the buffer rib 113 to deform and reduce the influence of the residual stress on the notched groove 111. The buffer rib 113 plays a role in buffering pressure and releases the residual stress, thereby avoiding the cracking of the weak notched groove 111, thereby maintaining the stability of the bursting pressure of the notched groove 111.

[0037] It should be noted that in this embodiment, the notched groove 111 and the buffer rib 113 are both annular closed structures. By providing the notched groove 111 in annular closed shape, when the internal gas pressure of the battery reaches a preset value, the notched groove 111 can be completely exploded, thereby effectively releasing the pressure inside the battery, so that the rapidly increased gas pressure inside the battery can be leaked in time.

[0038] Of course, in other parallel embodiments, the notched groove 111 may also be configured to be non-closed. When the non-closed notched groove 111 explodes, it will explode along the notched groove 111, and the portion of the explosion-proof plate 11 without the notched groove 111 will not explode, thereby avoiding the splashing of fragments of the explosion-proof plate 11 and preventing the hidden danger of short circuit in other batteries.

[0039] Optionally, in this embodiment, a buffer rib 113 is provided between the notched groove 111 and the welded outer ring 112 along the radial direction of the explosion-proof disc 11, so as to separate the notched groove 111 and the welded outer ring 112 on a limited area, so that the notched groove 111 can be away from the welded outer ring 112 to a safe distance. Of course, it is understandable that in other parallel embodiments, when the area of ​​the explosion-proof disc 11 is sufficient, multiple buffer ribs 113 can be designed between the notched groove 111 and the welded outer ring 112, so as to be more helpful in releasing the pressure generated during the welding process and making the notched groove 111 safer.

[0040] Combination Figure 2 , Figure 3As shown, the welding outer ring 112 is configured as a step-shaped structure to increase the thickness of the welding outer ring 112, thereby helping to increase the welding strength and stability between the explosion-proof plate 11 and the top cover plate.

[0041] refer to Figure 3 As shown, the distance h between the top of the buffer rib 113 and the surface of the explosion-proof disk 11 is 0.1-0.3 mm. For example, the distance h can be 0.1 mm, 0.2 mm, or 0.3 mm. It is preferred that the distance h does not exceed the upper surface of the welded outer ring 112, so as to prevent the explosion-proof valve assembly from being scratched by friction with adjacent explosion-proof valve assemblies when the explosion-proof valve assembly is stacked. Those skilled in the art can select a specific value of the distance h according to actual conditions, and the utility model does not limit this. Preferably, in this embodiment, the distance h is 0.2 mm.

[0042] Continue to refer Figure 3 As shown, the side wall inclination angle α of the buffer rib 113 is 45°-65°. For example, the inclination angle α can be 45°, 50°, 55°, 60°, 65°, which helps to reduce the deformation difficulty of the buffer rib 113 when it is pulled by stress, and ensures that the buffer rib 113 can effectively absorb residual stress. The utility model does not limit the inclination angle α of the side wall of the buffer rib 113. Preferably, in this embodiment, the inclination angle α of the side wall of the buffer rib 113 is 60°, which can help reduce the friction between the mold and the explosion-proof disk 11, make the mold opening smoother, and increase the success rate of molding.

[0043] Furthermore, the corner end 1131 of the buffer rib 113 is configured to be in an arc shape. The arc-shaped corner end 1131 can reduce the risk of the buffer rib 113 being damaged or deformed, and can also better protect the life of the mold.

[0044] Furthermore, in this embodiment, the cross-sectional shape of the buffer rib 113 is U-shaped. The U-shaped structure can provide a larger surface area for the buffer rib 113, thereby giving the buffer rib 113 a stronger energy absorption capacity, and can effectively absorb the stress generated during the laser welding process, thereby providing the maximum protection effect for the notched groove 111. In addition, the U-shaped buffer rib 113 can also provide better stability, and can effectively resist the forces in the lateral and vertical directions, thereby helping to maintain the stability and strength of the overall structure of the buffer rib 113 and reduce damage and destruction.

[0045] It should be noted that, in some parallel embodiments, the cross-sectional shape of the buffer rib 113 may also be M-shaped, wavy, or other shapes. The above shapes all have a certain degree of anti-deformation ability and a good deformation effect, and therefore can meet the performance requirements of the present invention for the buffer rib 113. Therefore, these cross-sectional shapes also fall within the scope of protection of the present invention.

[0046] Optionally, in this embodiment, a buffer rib 113 is protrudingly provided on the top of the explosion-proof disc 11 to meet the mold opening requirements and facilitate the stacking of the explosion-proof valve structure. Of course, in other parallel embodiments, the buffer rib 113 may be protrudingly provided only on the bottom of the explosion-proof disc 11, or the buffer rib 113 may be protrudingly provided on both the top and the bottom of the explosion-proof disc 11, and the utility model is not limited thereto.

[0047] This embodiment also provides a top cover, including a top cover sheet and the above-mentioned explosion-proof valve structure, wherein a pressure relief port is provided on the top cover sheet, the explosion-proof valve structure is sealed and connected to the pressure relief port, and the explosion-proof sheet 11 in the explosion-proof valve structure can be fixedly connected to the top cover sheet by laser welding. In the explosion-proof valve structure, a buffer rib 113 is provided on the explosion-proof sheet 11, which can set the notched groove 111 and the welding outer ring 112 at intervals. The buffer rib 113 can absorb and eliminate the stress generated during the annealing process, thereby avoiding the influence of the stress on the notched groove 111 and preventing the notched groove 111 from deforming. Therefore, by connecting the above-mentioned explosion-proof valve structure to the top cover sheet, the production quality and production efficiency of the top cover can be effectively improved, so that the top cover can release the internal gas after the internal pressure of the battery reaches a preset value, thereby ensuring the reliability of the use of the top cover.

[0048] This embodiment also provides a battery, including a single cell, a shell and the above-mentioned top cover, the shell having a receiving cavity, the single cell is located in the receiving cavity, and the top cover sealing cover is arranged at the opening of the shell receiving cavity to seal the single cell. The battery can improve the production efficiency by arranging the above-mentioned top cover, and avoid the situation that the scored groove 111 bursts open before the internal gas pressure of the battery reaches a preset value, thereby ensuring the safety of the battery.

[0049] In the description of this specification, the description of reference terms such as "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0050] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. An explosion-proof valve structure, arranged at a pressure relief port of a battery, the explosion-proof valve structure comprising an explosion-proof disc (11), characterized in that: Along the radial direction, the explosion-proof plate (11) is provided with a notched groove (111), a buffer convex rib (113) and a welding outer ring (112) in sequence from the inside to the outside; the notched groove (111) is configured so that when the internal pressure of the battery exceeds a preset value, the explosion-proof plate (11) ruptures at the notched groove (111); the buffer convex rib (113) is protrudingly arranged on the surface of the explosion-proof plate (11); the buffer convex rib (113) is arranged around the notched groove (111); and the welding outer ring (112) is configured to be fixedly connected to the top cover plate of the battery by welding.

2. The explosion-proof valve structure according to claim 1, characterized in that: The cross-sectional shape of the buffer rib (113) is U-shaped, M-shaped or wave-shaped.

3. The explosion-proof valve structure according to claim 1, characterized in that: The cross-sectional shape of the buffer rib (113) is U-shaped.

4. The explosion-proof valve structure according to claim 1, characterized in that: The top of the explosion-proof disc (11) is provided with the buffer convex rib (113) protrudingly; and / or the bottom of the explosion-proof disc (11) is provided with the buffer convex rib (113) protrudingly.

5. The explosion-proof valve structure according to claim 1, characterized in that: Along the radial direction of the explosion-proof disk (11), a plurality of buffer ribs (113) are arranged at intervals between the notched groove (111) and the welded outer ring (112).

6. The explosion-proof valve structure according to claim 1, characterized in that: The distance between the top of the buffer rib (113) and the surface of the explosion-proof disk (11) is 0.1-0.3 mm.

7. The explosion-proof valve structure according to claim 1, characterized in that: The side wall inclination angle of the buffer rib (113) is 45°-65°.

8. The explosion-proof valve structure according to claim 1, characterized in that: The notched groove (111) and the buffer rib (113) are both annular closed structures.

9. A top cover, characterized in that: It comprises a top cover sheet and an explosion-proof valve structure as described in any one of claims 1 to 8, wherein the top cover sheet is provided with a pressure relief port, the explosion-proof valve structure is sealed and connected to the pressure relief port, and the explosion-proof sheet (11) in the explosion-proof valve structure is welded and connected to the top cover sheet.

10. A battery, characterized in that The invention comprises a single battery cell, a shell and the top cover as claimed in claim 9, wherein the single battery cell is accommodated in the shell, and the top cover sealing cover is arranged at the opening of the shell.

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