Battery top cover, battery casing and power battery

Abstract

This utility model belongs to the field of battery technology and discloses a battery top cover, a battery casing, and a power battery. The battery top cover includes a top cover sheet and an explosion-proof valve assembly. The top cover sheet is made of stainless steel and has explosion-proof holes. The explosion-proof valve assembly includes a valve body made of aluminum alloy. The valve body is located on the side of the top cover sheet facing the battery cell. The valve body and the top cover sheet can be riveted and self-locked to seal the end of the explosion-proof hole facing the battery cell. The surface of the valve body facing away from the battery cell has explosion-proof markings. This battery top cover ensures the high structural strength advantage of a thin top cover sheet while solving the problem of difficult processing of high-strength materials and meeting the requirements of precise voltage control for power batteries.

Description

Technical Field

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

[0002] Power batteries are widely used due to their advantages such as high energy density, high power density, long cycle life, high safety, and low cost. In the actual production of power batteries, the battery casing or top cover is usually made of stainless steel, which has high strength and corrosion resistance, to achieve a thin battery casing design. For example, the thickness of the battery top cover can be reduced to 0.3mm-0.5mm, improving the space utilization and energy density of the power battery.

[0003] Typically, stainless steel power batteries require an explosion-proof valve on their casing. This valve is designed to rupture precisely when the internal pressure of the battery is abnormal, releasing pressure and preventing an explosion. Traditionally, the explosion-proof valve for stainless steel power batteries involves creating ultra-thin grooves (residual thickness typically ≤0.05mm) on the casing (e.g., the top cover). Specifically, this can be achieved by directly stretching and thinning the stainless steel top cover before groove formation, or by groove formation on a thin stainless steel sheet followed by laser welding to the stainless steel top cover. However, both methods present several problems: firstly, the high strength of stainless steel makes groove formation difficult; secondly, during the thinning, stamping, and laser welding processes, stress concentration and thermal deformation in the stainless steel result in a cracking rate of 15-20% at the grooves, leading to a burst pressure deviation rate exceeding ±12% for the stainless steel explosion-proof valve, which fails to meet the precise pressure control requirements of stainless steel power batteries.

[0004] Therefore, there is an urgent need to propose a battery top cover, battery casing, and power battery to solve the above problems. Utility Model Content

[0005] The first objective of this utility model is to provide a battery top cover that, while ensuring the high structural strength of the thin top cover sheet, also solves the problem of difficult processing of high-strength materials and meets the requirements of precise voltage control for power batteries.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] Battery top cover, including:

[0008] The top cover plate is made of stainless steel and has explosion-proof holes.

[0009] An explosion-proof valve assembly includes a valve body made of aluminum alloy. The valve body is located on the side of the top cover plate facing the battery cell. The valve body and the top cover plate can be riveted and self-locked to seal the end of the explosion-proof hole facing the battery cell. The surface of the valve body facing away from the battery cell is provided with explosion-proof markings.

[0010] As an optional technical solution for the battery top cover, the top cover sheet has a first groove on the side facing the battery cell, the explosion-proof hole is located at the bottom of the first groove, and the valve body is located in the first groove and connected to the side wall of the first groove.

[0011] As an optional technical solution for the battery top cover, the first groove is formed by the top cover sheet through multi-stage stretching, and a protrusion corresponding to the first groove is formed on the side of the top cover sheet opposite to the battery cell.

[0012] As an optional technical solution for the battery top cover, the radial dimension of the first groove gradually increases along the groove depth direction, the valve body is adapted to the shape of the first groove, and the valve body can be locked in the first groove.

[0013] As an optional technical solution for the battery top cover, the raised outer side wall and the side of the top cover plate opposite to the battery cell are arranged to form a second groove. The explosion-proof valve assembly also includes a reinforcing member that can be engaged in the second groove.

[0014] As an optional technical solution for the battery top cover, the reinforcing member extends circumferentially along the second groove and is arranged in a closed loop.

[0015] As an optional technical solution for the battery top cover, the explosion-proof hole is coaxially arranged with the valve body.

[0016] The second objective of this invention is to provide a battery casing that has high structural strength, is simple to process, and can meet the requirements of precise voltage control for power batteries.

[0017] To achieve this objective, the present invention adopts the following technical solution:

[0018] The battery casing includes an outer shell and the aforementioned battery top cover, wherein one end of the outer shell has an opening and the top cover sheet seals the opening.

[0019] As an optional technical solution for the battery casing, the top cover and the outer shell are integrally formed.

[0020] The third objective of this invention is to provide a power battery with high safety performance and high production yield.

[0021] To achieve this objective, the present invention adopts the following technical solution:

[0022] A power battery includes a battery cell and a battery casing, wherein the battery cell is located inside the casing, and a top cover is provided on the opening of the casing to seal the battery cell inside the casing.

[0023] The beneficial effects of this utility model are:

[0024] The battery top cover provided by this utility model includes a top cover sheet and an explosion-proof valve assembly. The top cover sheet is made of stainless steel, which has high strength and allows for a thin design. The explosion-proof valve assembly includes a valve body with explosion-proof grooves on the side of the valve body facing away from the battery cell. The valve body is made of aluminum alloy, which has low strength and can avoid stress concentration during groove processing. The valve body is riveted to the top cover sheet for self-locking fixation to avoid thermal deformation, thereby preventing excessive deviation in the valve body's burst pressure. The top cover sheet has an explosion-proof hole, and the valve body is sealed at the end of the explosion-proof hole facing the battery cell. When the internal pressure of the power battery is abnormal, it can rupture precisely to release the pressure and prevent the power battery from exploding. Compared to traditional power batteries where ultra-thin grooves on the top cover cause stress concentration and thermal deformation, this power battery's top cover is made of stainless steel, while the valve body is made of aluminum alloy. The valve body and the top cover can be riveted and self-locked together. This not only ensures the high structural strength of the thin top cover but also solves the problem of processing high-strength materials and meets the requirements for precise voltage control of power batteries, thereby improving the safety performance and production yield of power batteries. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the battery top cover (after the top cover piece and the explosion-proof valve assembly are riveted together) provided in Embodiment 1 of this utility model;

[0026] Figure 2 This is a cross-sectional view of the battery top cover (after the top cover piece and the explosion-proof valve assembly are riveted together) provided in Embodiment 1 of this utility model;

[0027] Figure 3 yes Figure 2 A magnified view of a portion at point A;

[0028] Figure 4 This is a schematic diagram of the structure of the battery top cover (before the top cover piece and the explosion-proof valve assembly are riveted) provided in Embodiment 1 of this utility model;

[0029] Figure 5 This is a cross-sectional view of the battery top cover (before the top cover piece and the explosion-proof valve assembly are riveted) provided in Embodiment 1 of this utility model;

[0030] Figure 6 yes Figure 5 A magnified view of a section at point B.

[0031] In the picture:

[0032] 100. Top cover plate; 110. First groove; 120. Protrusion; 210. Valve body; 211. Explosion-proof groove; 220. Reinforcing member. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0034] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0037] Example 1

[0038] This embodiment provides a battery top cover that, while ensuring the high structural strength of the thin top cover sheet, also solves the problem of difficult processing of high-strength materials and meets the requirements of precise voltage control of power batteries.

[0039] Specifically, such as Figures 1 to 6 As shown, the battery top cover includes a top cover plate 100 and an explosion-proof valve assembly. The top cover plate 100 is made of stainless steel and has an explosion-proof hole. The explosion-proof valve assembly includes a valve body 210, which is made of aluminum alloy. The valve body 210 is located on the side of the top cover plate 100 facing the battery cell. The valve body 210 and the top cover plate 100 can be riveted and self-locked to seal the end of the explosion-proof hole facing the battery cell. The surface of the valve body 210 facing away from the battery cell has explosion-proof markings 211.

[0040] It should be noted that the valve body 210 and the top cover plate 100 are connected by a cold riveting process, and the cold riveting process is a relatively mature existing technology in this field, which will not be described in detail here.

[0041] Based on the above design, the top cover plate 100 is made of stainless steel, which has high strength and allows for a thin design. The valve body 210 has explosion-proof grooves 211 on the side facing away from the battery cell. The valve body 210 is made of aluminum alloy, which has low strength and can avoid stress concentration during groove processing. The valve body 210 and the top cover plate 100 are riveted and self-locked to prevent thermal deformation, thereby preventing excessive deviation rate of the valve body 210's burst pressure. The top cover plate 100 has an explosion-proof hole, and the valve body 210 is sealed at the end of the explosion-proof hole facing the battery cell. When the internal pressure of the power battery is abnormal, it can rupture precisely to release the pressure and prevent the power battery from exploding. Compared to the stress concentration and thermal deformation caused by ultra-thin grooves on the top cover of traditional power batteries, the top cover plate 100 of this power battery is made of stainless steel, and the valve body 210 is made of aluminum alloy. The valve body 210 and the top cover plate 100 can be riveted and locked together. While ensuring the high structural strength of the thin top cover plate 100, it also solves the problem of difficult processing of high-strength materials, meets the requirements of precise voltage control of power batteries, and thus improves the safety performance and production yield of power batteries.

[0042] Optionally, the explosion-proof hole is coaxially arranged with the valve body 210 to improve the symmetry between the valve body 210 and the explosion-proof hole, so that the burst pressure on the valve body 210 is uniform.

[0043] Optionally, the top cover plate 100 has a first groove 110 on the side facing the battery cell, the explosion-proof hole is located at the bottom of the first groove 110, the valve body 210 is located in the first groove 110 and connected to the side wall of the first groove 110, that is, the valve body 210 is embedded in the first groove 110 and riveted to the side wall of the first groove 110, which can save space and improve the connection strength between the valve body 210 and the top cover plate 100.

[0044] Furthermore, the first groove 110 is formed by the top cover sheet 100 through multi-stage stretching, and a protrusion 120 corresponding to the first groove 110 is formed on the side of the top cover sheet 100 away from the battery cell. The first groove 110 is formed by stamping, stretching and thinning, which is simple to process and can ensure the structural strength of the top cover sheet 100 at the first groove 110.

[0045] In this specific embodiment, along the depth direction of the first groove 110, the radial dimension of the first groove 110 gradually increases, and the shape of the valve body 210 is adapted to the first groove 110, so that the valve body 210 can be locked inside the first groove 110. That is, the sidewall of the first groove 110 (the sidewall of the protrusion 120) is inclined outward, and the valve body 210 can be clamped and fixed by the bottom wall and sidewall of the first groove 110 to form a self-locking mechanism.

[0046] Furthermore, a second groove is formed by surrounding the outer wall of the protrusion 120 and the side of the top cover plate 100 away from the battery cell. The explosion-proof valve assembly also includes a reinforcing member 220, which can be locked in the second groove. On the one hand, it is to improve the connection strength between the protrusion 120 and the top cover plate 100, and on the other hand, it is to ensure that the reinforcing member 220 can support and fix the inclined side wall of the protrusion 120, thus providing a guarantee for the self-locking of the valve body 210 and the top cover plate 100.

[0047] In this embodiment, the reinforcing member 220 extends circumferentially along the second groove and is arranged in a closed loop.

[0048] In the actual production of the battery top cover, the first groove 110 is first formed on the stainless steel top cover plate 100 through multi-stage stretching. The aluminum alloy valve body 210 is then embedded in the first groove 110. A reinforcing member 220 is then fitted on the outer wall of the protrusion 120 corresponding to the first groove 110 of the top cover plate 100. Then, the mechanical interlocking of the top cover plate 100, valve body 210 and reinforcing member 220 is achieved through a cold riveting process. At the same time, explosion-proof grooves 211 are pressed on the aluminum alloy valve body 210.

[0049] This embodiment also provides a battery housing with high structural strength, simple processing, and the ability to meet the requirements of precise voltage control for power batteries.

[0050] The battery casing includes an outer shell (not shown in the figure) and the aforementioned top cover. One end of the outer shell has an opening, and the top cover 100 seals the opening, forming the entire battery casing. The top cover 100 is made of stainless steel, while the valve body 210 of the explosion-proof valve assembly is made of aluminum alloy. The valve body 210 and the top cover 100 can be riveted and self-locked together. This design ensures the high structural strength of the thin top cover 100 while also solving the problem of processing high-strength materials and meeting the requirements for precise voltage control of the power battery, thereby improving the safety performance and production yield of the power battery.

[0051] In this embodiment, the battery casing also includes a terminal assembly, a sealing ring, an upper plastic component, and a lower plastic component. The upper plastic component is located on the side of the battery casing facing away from the battery cell, and the lower plastic component is located on the side of the battery casing facing the lower plastic component. The terminal assembly passes through the battery casing and is connected to both the upper and lower plastic components. The specific assembly methods of the terminal assembly, sealing ring, upper and lower plastic components, etc., with the battery casing are existing technologies in the art and will not be described in detail here.

[0052] In one specific embodiment, the battery casing is square, and the square battery casing is formed by two opposing first walls and four second walls connected end to end. The top cover 100 is one of the second walls of the square battery casing.

[0053] In other specific embodiments, the battery casing can also be cylindrical, and the cylindrical battery casing is formed by a cylindrical third wall and two fourth walls arranged vertically opposite each other, and the top cover 100 is one of the fourth walls of the cylindrical battery casing.

[0054] It is worth noting that the number of battery top covers of the battery casing can be multiple, that is, the number of top cover pieces 100 can be multiple. In other words, explosion-proof valve assemblies are provided on multiple (two, three or four) second walls of the square battery casing, or explosion-proof valve assemblies are provided on both fourth walls of the cylindrical battery casing.

[0055] This embodiment also provides a power battery with high safety performance and high production yield.

[0056] Specifically, the power battery includes a cell (not shown in the figure) and the aforementioned battery casing. The cell is located inside the casing, and a top cover 100 covers the opening in the casing to seal the cell inside. The top cover 100 on the battery casing is made of stainless steel, and the valve body 210 on the battery casing is made of aluminum alloy. The valve body 210 and the top cover 100 can be riveted and self-locked together. This design ensures the high structural strength of the thin battery casing while solving the problem of difficult processing of high-strength materials and meeting the requirements for precise voltage control of the power battery, thereby improving the safety performance and production yield of the power battery.

[0057] Example 2

[0058] This embodiment provides a battery casing, which differs from the battery casing of Embodiment 1 in that:

[0059] The top cover 100 of the battery casing is integrally formed with the outer shell, making it simple to process.

[0060] The battery casing provided in this embodiment differs from the battery casing provided in Embodiment 1 only in the above-mentioned aspects; all other parts are the same and will not be described in detail here.

[0061] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A battery top cover characterized by, include: Top cover plate (100), the top cover plate (100) is made of stainless steel, and the top cover plate (100) is provided with explosion-proof holes; An explosion-proof valve assembly includes a valve body (210) made of aluminum alloy. The valve body (210) is located on the side of the top cover plate (100) facing the battery cell. The valve body (210) and the top cover plate (100) can be riveted and self-locked to seal the end of the explosion-proof hole facing the battery cell. The surface of the valve body (210) facing away from the battery cell is provided with explosion-proof markings (211).

2. The battery header of claim 1, wherein, The top cover plate (100) has a first groove (110) on the side facing the battery cell. The explosion-proof hole is located at the bottom of the first groove (110). The valve body (210) is located in the first groove (110) and connected to the side wall of the first groove (110).

3. The battery header of claim 2, wherein, The first groove (110) is formed by the top cover plate (100) through multi-stage stretching, and a protrusion (120) corresponding to the first groove (110) is formed on the side of the top cover plate (100) opposite to the battery cell.

4. The battery header of claim 3, wherein, Along the groove depth direction of the first groove (110), the radial dimension of the first groove (110) gradually increases, the shape of the valve body (210) is adapted to the first groove (110), and the valve body (210) can be locked in the first groove (110).

5. The battery header of claim 4, wherein, The outer wall of the protrusion (120) and the top cover plate (100) on the side away from the battery cell form a second groove. The explosion-proof valve assembly also includes a reinforcing member (220) that can be engaged in the second groove.

6. The battery header of claim 5, wherein, The reinforcing member (220) extends circumferentially along the second groove and is arranged in a closed loop.

7. The battery cover of any one of claims 1-6, wherein the cover is made of a material selected from the group consisting of: aluminum, steel, and a combination thereof. The explosion-proof hole is coaxially arranged with the valve body (210).

8. A battery housing, characterized by The battery includes a housing and a battery top cover as described in any one of claims 1-7, wherein one end of the housing has an opening and the top cover sheet (100) seals the opening.

9. The battery case of claim 8, wherein, The top cover (100) and the outer shell are integrally formed.

10. A power cell, characterized by The battery includes a battery cell and a battery housing as described in claim 8 or claim 9, wherein the battery cell is located inside the housing and the top cover (100) covers the opening of the housing to seal the battery cell inside the housing.

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