Battery top cover and battery

Abstract

The utility model provides a battery top cover and a battery, the battery top cover comprises a top cover body, the top cover body is provided with an explosion-proof hole, and the explosion-proof hole penetrates through the top cover body; the explosion-proof piece comprises a connecting part and a blocking part which are connected with each other, the connecting part is fixedly connected with the top cover body, and the blocking part is configured to block the explosion-proof hole when the internal pressure of the battery is smaller than a pressure relief threshold value of the explosion-proof piece and open the explosion-proof hole when the internal pressure of the battery reaches the pressure relief threshold value of the explosion-proof piece. The connecting part is fixedly connected with the top cover body, the anti-explosion hole is plugged by the plugging part when the internal pressure of the battery is smaller than the pressure relief threshold value of the anti-explosion piece, and the anti-explosion hole is opened when the internal pressure of the battery reaches the pressure relief threshold value of the anti-explosion piece, so that one-way exhaust and pressure relief of the anti-explosion piece can be realized, and the air pressure in the battery can be effectively reduced in time; therefore, the safety risk caused by gas production at the end of battery circulation is reduced.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a battery top cover and a battery. Background Technology

[0002] When a battery experiences a short circuit or is compressed, it can cause internal gas production, ignition, or even an explosion. A common solution is to add an explosion-proof valve to the battery's top cover. When gas is generated inside the battery and the internal gas pressure reaches the explosion-proof valve's burst pressure, the explosion-proof plate on the top cover ruptures, allowing the gas inside the battery to escape through the valve opening and preventing the battery from exploding due to gas expansion.

[0003] However, throughout the battery's lifespan, as the cycle progresses, the negative electrode reacts with the electrolyte, causing the electrolyte to decompose and produce gas. This increases the internal gas pressure of the battery, resulting in the battery swelling at the end of the cycle. This puts enormous pressure on battery structural components and welds, posing safety hazards such as failure of structural components and welds. Utility Model Content

[0004] The present invention provides a battery top cover and a battery, which can improve the safety problem caused by gas generation at the end of the battery cycle.

[0005] In a first aspect, embodiments of the present invention provide a battery top cover, comprising:

[0006] The top cover body has an explosion-proof hole that penetrates through the top cover body;

[0007] An explosion-proof plate includes a connecting part and a sealing part that are connected to each other. The connecting part is fixedly connected to the top cover body. The sealing part is configured to block the explosion-proof hole when the internal pressure of the battery is less than the pressure relief threshold of the explosion-proof plate, and to open the explosion-proof hole when the internal pressure of the battery reaches the pressure relief threshold of the explosion-proof plate.

[0008] In one embodiment, the top cover body includes a cover plate and a lower plastic part, the lower plastic part being fixedly connected to the cover plate, and the end of the connecting part away from the sealing part being engaged between the lower plastic part and the cover plate.

[0009] In one embodiment, the explosion-proof hole includes a first through hole and a second through hole that are interconnected. The first through hole penetrates the cover plate, and the second through hole penetrates the lower plastic. The diameter of the first through hole is larger than the diameter of the second through hole. The connecting part and the sealing part are disposed in the first through hole, and the sealing part seals the second through hole.

[0010] In one embodiment, the top cover body has an outer surface facing away from the lower plastic, the lower plastic has a first surface and a second surface exposed from the first through hole, the first surface contacts the connecting portion, the second surface contacts the end of the sealing portion away from the connecting portion, and the second surface is closer to the outer surface than the first surface; and / or

[0011] The end of the sealing portion away from the connecting portion is spaced apart from the wall of the first through hole.

[0012] In one embodiment, the sealing portion includes a base and a sealing portion, the base being connected to the connecting portion, the sealing portion protruding from the base and configured to close the explosion-proof hole when the internal pressure of the battery is less than the pressure relief threshold.

[0013] In one embodiment, the peripheral surface of the sealing part is an arc-shaped surface, and the side of the explosion-proof hole opposite to the sealing part has an arc-shaped structure that matches the arc-shaped surface.

[0014] In one embodiment, the explosion-proof sheet is integrally formed.

[0015] In one embodiment, the side of the explosion-proof sheet opposite to the top cover body is provided with a sealing coating.

[0016] In one embodiment, the pressure relief threshold of the explosion-proof sheet is 0.10 MPa-0.14 MPa.

[0017] Secondly, embodiments of this utility model provide a battery, including the aforementioned battery top cover.

[0018] The beneficial effects of the embodiments of this utility model are as follows:

[0019] In embodiments of this utility model, by fixing the connecting part to the top cover body, the sealing part seals the explosion-proof hole when the internal pressure of the battery is less than the pressure relief threshold of the explosion-proof sheet, and opens the explosion-proof hole when the internal pressure of the battery reaches the pressure relief threshold of the explosion-proof sheet, thereby achieving one-way venting and pressure relief of the explosion-proof sheet. Specifically, when the internal pressure of the battery reaches the pressure relief threshold of the explosion-proof sheet, pressure relief is achieved by separating the end of the sealing part of the explosion-proof sheet away from the connecting part from the explosion-proof hole, while avoiding the explosion-proof sheet from rupture. When the internal pressure of the battery is less than the pressure relief threshold of the explosion-proof sheet, the sealing part seals the explosion-proof hole by means of the elastic reset of the connecting part. Thus, the internal air pressure of the battery can be reduced in a timely and effective manner, thereby reducing the safety risk caused by gas generation at the end of the battery cycle and improving the safety performance of the battery at the end of its use. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a cross-sectional view of the battery top cover provided in an embodiment of this utility model;

[0022] Figure 2 yes Figure 1 Enlarged view of point A in the middle.

[0023] Reference numerals: Top cover body - 1; Explosion-proof hole - 11; First through hole - 111; Second through hole - 112; Cover plate - 12; Lower plastic - 13; First surface - 131; Second surface - 132; Outer surface - 14; Explosion-proof sheet - 2; Connecting part - 21; Sealing part - 22; Base - 221; Sealing part - 222; Arc-shaped surface - 2221; Sealing coating - 3. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0025] In a first aspect, embodiments of the present invention provide a battery top cover, comprising:

[0026] The top cover body 1 is provided with an explosion-proof hole 11, which penetrates the top cover body 1.

[0027] The explosion-proof plate 2 includes a connecting part 21 and a sealing part 22 that are connected to each other. The connecting part 21 is fixedly connected to the top cover body 1. The sealing part 22 is configured to seal the explosion-proof hole 11 when the internal pressure of the battery is less than the pressure relief threshold of the explosion-proof plate 2, and to open the explosion-proof hole 11 when the internal pressure of the battery reaches the pressure relief threshold of the explosion-proof plate 2.

[0028] It is understood that the explosion-proof sheet 2 has a sheet-like structure, which can be divided into two parts: a connecting part 21 and a sealing part 22. The connecting part 21 is fixedly connected to the top cover body 1, thereby fixing the explosion-proof sheet 2 to the top cover body 1. The connecting part 21 and the top cover body 1 can be fixedly connected by welding, snap-fitting, or other methods. The connecting part 21 can have a certain degree of elasticity. When the internal pressure of the battery is less than the pressure relief threshold of the explosion-proof plate 2, the explosion-proof plate 2 is in contact with the top cover. At this time, the sealing part 22 completely covers the explosion-proof hole 11, thereby sealing the explosion-proof hole 11. When the internal pressure of the battery is greater than or equal to the pressure relief threshold of the explosion-proof plate 2, the sealing part 22 is pushed open by the gas inside the battery. That is, the sealing part 22 moves away from the explosion-proof plate 2, thereby opening the explosion-proof hole 11 to relieve pressure. As the gas inside the battery is discharged, the gas pressure inside the battery gradually decreases. When the gas pressure inside the battery drops to less than the pressure relief threshold of the explosion-proof plate 2, the explosion-proof plate 2 begins to move towards the explosion-proof plate 2. This cycle continues, thereby achieving real-time pressure relief of the battery, avoiding excessive accumulation of internal pressure, and thus improving the safety performance at the end of the battery cycle.

[0029] It is understood that the explosion-proof sheet 2 can be made of metals such as stainless steel, aluminum, and nickel. Metal materials possess a certain rigidity, and within a certain elastic range, the explosion-proof sheet 2 can deform and has the ability to automatically recover its deformation. The length, thickness, width, and material of the explosion-proof sheet 2 affect its deformation capacity and pressure-bearing capacity. In this application, the length, thickness, width, and material of the explosion-proof sheet 2 can be adjusted according to the required pressure relief threshold of the battery. The battery's pressure relief threshold (i.e., the pressure relief threshold of the explosion-proof sheet mentioned above) and the size of the explosion-proof hole 11 can be set according to the battery's gas generation conditions, etc.

[0030] It is understandable that, in order to enable the sealing part 22 to better seal the explosion-proof hole 11, a sealing structure, such as a sealing strip or sealing coating 3, can be provided on the side of the sealing part 22 opposite to the explosion-proof hole 11. Alternatively, the shape of the side of the sealing part 22 that seals the explosion-proof hole 11 can be matched with the shape of the explosion-proof hole 11, thereby improving the sealing performance of the sealing part 22 on the explosion-proof hole 11.

[0031] In one embodiment, the top cover body 1 includes a cover plate 12 and a lower plastic 13, the lower plastic 13 being fixedly connected to the cover plate 12, and the end of the connecting part 21 away from the sealing part 22 being engaged between the lower plastic 13 and the cover plate 12.

[0032] It is understood that the lower plastic part 13 is a plastic support, which prevents the battery cell from contacting the cover plate 12. The lower plastic part 13 is fixed to one surface of the cover plate 12, and the end of the connecting part 21 away from the sealing part 22 is engaged between the lower plastic part 13 and the cover plate 12, thereby fixing the explosion-proof sheet 2 to the top cover body 1. During installation, the end of the connecting part 21 away from the sealing part 22 can be placed between the lower plastic part 13 and the cover plate 12 first, and then the lower plastic part 13 and the cover plate 12 can be fixedly connected, thereby achieving the goal of engaging the end of the connecting part 21 away from the sealing part 22 between the lower plastic part 13 and the cover plate 12, which is simple and easy to operate.

[0033] In one embodiment, the explosion-proof hole 11 includes a first through hole 111 and a second through hole 112 that are interconnected. The first through hole 111 penetrates the cover plate 12, and the second through hole 112 penetrates the lower plastic 13. The diameter of the first through hole 111 is larger than the diameter of the second through hole 112. The connecting part 21 and the sealing part 22 are disposed in the first through hole 111, and the sealing part 22 seals the second through hole 112.

[0034] It is understood that the first through hole 111 and the second through hole 112 are interconnected, allowing the gas inside the battery to be discharged sequentially through the first through hole 111 and the second through hole 112. In the projection plane perpendicular to the axis of the through hole, the projection of the first through hole 111 can completely cover the projection of the second through hole 112, thereby facilitating the rapid discharge of gas. The sealing part 22 seals the second through hole 112, thus achieving the sealing of the explosion-proof hole 11.

[0035] In embodiments where a sealing structure is provided on the side of the sealing portion 22 opposite to the explosion-proof hole 11, the sealing structure can be positioned opposite the surface of the sealing portion 22 and the surface of the lower plastic 13 exposed from the first through hole 111 (which can be understood as the bottom of the first through hole 111). That is, the sealing structure abuts against the bottom of the first through hole 111 to improve the sealing performance of the sealing portion 22 on the explosion-proof hole 11 when the internal pressure of the battery is less than the pressure relief threshold.

[0036] In one embodiment, the top cover body 1 has an outer surface 14 facing away from the lower plastic 13. The lower plastic 13 has a first surface 131 and a second surface 132 exposed from the first through hole 111. The first surface 131 contacts the connecting portion 21, and the second surface 132 contacts the end of the sealing portion 22 away from the connecting portion 21. The second surface 132 is closer to the outer surface 14 than the first surface 131.

[0037] For example, the first surface 131 and the second surface 132 can be stepped surfaces and are parallel to each other.

[0038] It is understood that the lower plastic 13 has a first surface 131 and a second surface 132 exposed from the first through hole 111, with the first surface 131 and the second surface 132 located on both sides of the second through hole 112. The connecting part 21 of the explosion-proof sheet 2 is fixedly connected to the top cover body 1. When the explosion-proof sheet 2 blocks the explosion-proof hole 11, the first surface 131 can be tightly bonded to the sealing part 22. The second surface 132 is closer to the outer surface 14 than the first surface 131. When the explosion-proof sheet 2 blocks the explosion-proof hole 11, the second surface 132 can be tightly bonded to the sealing part 22, thereby improving the sealing effect of the sealing part 22 on the explosion-proof hole 11.

[0039] In one embodiment, the end of the sealing portion 22 away from the connecting portion 21 is spaced apart from the wall of the first through hole 111.

[0040] It is understandable that when the explosion-proof plate 2 is subjected to the internal pressure of the battery and moves away from the explosion-proof hole 11, the end of the sealing part 22 away from the connecting part 21 will move along an arc-shaped trajectory with the end of the connecting part 21 fixed to the top cover body 1 as the center (or, with the part of the connecting part 21 in contact with the side wall of the first through hole 111 as the center). By setting the end of the sealing part 22 away from the connecting part 21 at a distance from the wall of the first through hole 111, the movement of the sealing part 22 can be prevented from being hindered by the contact between the side wall of the first through hole 111 and the end of the sealing part 22 away from the connecting part 21. The distance between the end of the sealing part 22 away from the connecting part 21 and the wall of the first through hole 111 can be set as needed, as long as it does not affect the movement of the sealing part 22 and the sealing performance of the sealing part 22 to the explosion-proof hole 11.

[0041] In one embodiment, the sealing portion 22 includes a base 221 and a sealing portion 222. The base 221 is connected to the connecting portion 21, and the sealing portion 222 protrudes from the base 221 and is configured to close the explosion-proof hole 11 when the internal pressure of the battery is less than the pressure relief threshold.

[0042] For example, the base 221 and the connecting portion 21 may have the same thickness, and both may be coplanarly disposed away from the surface of the lower plastic 13. The sealing portion 222 protrudes from the base 221 near the surface of the lower plastic 13.

[0043] It is understandable that when the explosion-proof disc 2 seals the explosion-proof hole 11, the sealing part 222 is disposed within the explosion-proof hole 11, thereby better sealing the explosion-proof hole 11. When the explosion-proof hole 11 includes a first through hole 111 and a second through hole 112 that are interconnected, the sealing part 222 is disposed within the second through hole 112, thereby achieving the sealing of the explosion-proof hole 11. In order to make the sealing part 222 better seal the explosion-proof hole 11, a sealing structure, such as a sealing strip or a sealing coating 3, can be provided on the sealing part 222. Alternatively, the shape of the side of the sealing part 222 near the explosion-proof hole 11 can be made to match the shape of the explosion-proof hole 11, thereby improving the sealing performance of the sealing part 222 on the explosion-proof hole 11.

[0044] In one embodiment, the peripheral surface of the sealing part 222 is an arc-shaped surface 2221, and the side of the explosion-proof hole 11 opposite to the sealing part 22 has an arc-shaped structure that matches the arc-shaped surface 2221.

[0045] It can be understood that the sealing part 222 protrudes from the base 221, and the circumferential surface of the sealing part 222 is the surface that protrudes outward from the base 221. The circumferential surface of the sealing part 222 is an arc-shaped surface 2221. Correspondingly, the side of the explosion-proof hole 11 opposite to the sealing part 22 has an arc-shaped structure that matches the arc-shaped surface 2221. When the explosion-proof plate 2 seals the explosion-proof hole 11, the sealing part 222 is disposed inside the explosion-proof hole 11, and the arc-shaped surface 2221 of the sealing part 222 contacts the arc-shaped structure of the explosion-proof hole 11, which can achieve a tighter contact, thereby enabling the sealing part 222 to better seal the explosion-proof hole 11.

[0046] In one embodiment, the explosion-proof sheet 2 is a one-piece molded structure.

[0047] It is understandable that the explosion-proof sheet 2 is a one-piece molded structure, that is, the connecting part 21 and the sealing part 22 are molded as one piece, which makes it easier to process the explosion-proof sheet 2.

[0048] In one embodiment, the explosion-proof sheet 2 is provided with a sealing coating 3 on the side opposite to the top cover body 1.

[0049] It is understood that the sealing coating 3 can be disposed on the side opposite to the explosion-proof sheet 2 and the battery top cover (exemplarily, the surface of the lower plastic 13 exposed from the first through hole 111 mentioned above), which can improve the sealing effect of the explosion-proof sheet 2 on the explosion-proof hole 11 when the explosion-proof sheet 2 blocks the explosion-proof hole 11. The material of the sealing coating 3 may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), and polycarbonate (PC).

[0050] It is understandable that in order to make the sealing coating 3 more stable on the explosion-proof sheet 2, the sealing coating 3 can be wrapped on the explosion-proof sheet 2, which also facilitates the processing of the sealing coating 3.

[0051] In one embodiment, the pressure relief threshold of the explosion-proof sheet 2 is 0.10 MPa-0.14 MPa.

[0052] It can be understood that the pressure relief threshold of the explosion-proof plate 2 is 0.10 MPa-0.14 MPa, for example, it can be 0.10 MPa, 0.11 MPa, 0.12 MPa, 0.14 MPa, or any specific value between two of the above. When the internal air pressure of the battery cell reaches the pressure relief threshold, the sealing part 22 of the explosion-proof plate 2 leaves the sealing hole and begins to relieve pressure, thereby improving the safety of the battery in the later stages of cycle life.

[0053] Secondly, embodiments of this utility model provide a battery, including the aforementioned battery top cover.

[0054] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A battery top cover, characterized in that, include: The top cover body has an explosion-proof hole that penetrates through the top cover body; An explosion-proof plate includes a connecting part and a sealing part that are connected to each other. The connecting part is fixedly connected to the top cover body. The sealing part is configured to block the explosion-proof hole when the internal pressure of the battery is less than the pressure relief threshold of the explosion-proof plate, and to open the explosion-proof hole when the internal pressure of the battery reaches the pressure relief threshold of the explosion-proof plate.

2. The battery top cover according to claim 1, characterized in that, The top cover body includes a cover plate and a lower plastic part, the lower plastic part is fixedly connected to the cover plate, and the end of the connecting part away from the sealing part is engaged between the lower plastic part and the cover plate.

3. The top cover according to claim 2, characterized in that, The explosion-proof hole includes a first through hole and a second through hole that are interconnected. The first through hole penetrates the cover plate, and the second through hole penetrates the lower plastic. The diameter of the first through hole is larger than the diameter of the second through hole. The connecting part and the sealing part are disposed in the first through hole, and the sealing part seals the second through hole.

4. The battery top cover according to claim 3, characterized in that, The top cover body has an outer surface facing away from the lower plastic, and the lower plastic has a first surface and a second surface exposed from the first through hole. The first surface contacts the connecting portion, and the second surface contacts the end of the sealing portion away from the connecting portion. The second surface is closer to the outer surface than the first surface; and / or The end of the sealing portion away from the connecting portion is spaced apart from the wall of the first through hole.

5. The battery top cover according to claim 1, characterized in that, The sealing portion includes a base and a sealing portion. The base is connected to the connecting portion. The sealing portion protrudes from the base and is configured to close the explosion-proof hole when the internal pressure of the battery is less than the pressure relief threshold.

6. The battery top cover according to claim 5, characterized in that, The circumferential surface of the sealing part is an arc-shaped surface, and the side of the explosion-proof hole opposite to the sealing part has an arc-shaped structure that matches the arc-shaped surface.

7. The battery top cover according to claim 5, characterized in that, The explosion-proof sheet is integrally molded.

8. The battery top cover according to claim 1, characterized in that, The explosion-proof sheet has a sealing coating on the side opposite to the top cover body.

9. The battery top cover according to claim 1, characterized in that, The pressure relief threshold of the explosion-proof sheet is 0.10 MPa-0.14 MPa.

10. A battery, characterized in that, Includes the battery top cover as described in any one of claims 1-9.

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