Polished aluminum sheet, top cover assembly and battery cell

Abstract

A polished aluminum sheet, a top cover assembly and a battery cell. The polished aluminum sheet comprises a polished aluminum sheet body (1), the polished aluminum sheet body (1) being provided with a mounting portion and a liquid injection hole (11); the mounting portion is configured to mount an explosion-proof member (2), the liquid injection hole (11) is provided on the mounting portion and penetrates through the polished aluminum sheet body (1), and the explosion-proof member (2) is located above the liquid injection hole (11).

Description

Aluminum sheet, top cover assembly and battery cell

[0001] This application claims priority to Chinese patent application No. 202322927614.1 filed with the Patent Office of China on October 30, 2023. The entire contents of the above application are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a bare aluminum sheet, a top cover assembly, and a battery cell. Background Art

[0003] As lithium battery technology matures, it's widely used in electric vehicles and energy storage, raising the bar for performance and safety. The cover plate (also known as the top cover assembly), a lithium battery accessory, performs two functions: welding to the aluminum shell to isolate the internal and external environments, providing a seal; and connecting internal and external circuits, directing the battery's internal current through the cover plate terminals. SUMMARY OF THE INVENTION

[0004] However, in the related art, the top cover assembly includes parts such as bare aluminum sheet, upper plastic, terminal, pole, explosion-proof plate, sealing rubber particles, sealing nails, lower plastic, pole, pins, etc., and the large number of parts leads to high material cost, production cost and assembly cost.

[0005] The present application provides a plain aluminum sheet. The plain aluminum sheet includes a plain aluminum sheet body, the plain aluminum sheet body being provided with a mounting portion and a liquid injection hole, the mounting portion being configured to mount an explosion-proof component, the liquid injection hole being provided on the mounting portion and extending through the plain aluminum sheet body, and the explosion-proof component being located above the liquid injection hole.

[0006] The present application also provides a top cover assembly, comprising the above-mentioned smooth aluminum sheet.

[0007] The present application also provides a battery cell, comprising the above-mentioned top cover assembly. Beneficial effects

[0008] Compared with the solution in the related art in which the injection hole and the mounting portion for installing the explosion-proof component are separately arranged on the bare aluminum sheet, the bare aluminum sheet provided in the present application arranges the injection hole on the mounting portion, that is, the injection hole and the mounting portion for installing the explosion-proof component are integrated. Therefore, there is no need to design the explosion-proof component and the injection hole to prevent electrolyte leakage separately. It is only necessary to design the mounting portion to prevent electrolyte leakage, thereby reducing the number of seals required to prevent electrolyte leakage, eliminating the sealing rubber particles and sealing nails required to seal the injection hole, and then reducing the number of structural parts and the assembly process of the corresponding structural parts, which helps to reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG1 is a schematic diagram of the overall structure of a light aluminum sheet provided in this application;

[0010] FIG2 is an enlarged structural diagram of part A in FIG1 ;

[0011] FIG3 is a schematic diagram of the cross-sectional structure of the light aluminum sheet of FIG1 ;

[0012] FIG4 is a schematic diagram of the cross-sectional structure of a bare aluminum sheet provided in the present application with explosion-proof components installed thereon.

[0013] Description of reference numerals:

[0014] 1. Plain aluminum sheet body; 11. Liquid injection hole; 12. First sinking platform; 13. Second sinking platform; 14. Third sinking platform; 15. Boss; 2. Explosion-proof parts. Modes for Carrying Out the Invention

[0015] In the description of this application, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0016] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, with the first feature having a higher horizontal height than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, with the first feature having a lower horizontal height than the second feature.

[0017] In the description of this embodiment, terms such as "upper," "lower," "left," "right," "front," and "rear" are used to refer to positions or locations based on the positions or locations shown in the accompanying drawings. These terms are intended to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and do not have any special meanings.

[0018] The bare aluminum sheet, as a component of the top cover assembly, has the following functions: after being welded to the aluminum shell, it isolates the internal and external environments to achieve a sealing effect, and connects the internal and external circuits to transmit the internal current of the battery to the outside through the top cover pole to achieve a current diversion effect.

[0019] In the prior art, a plain aluminum sheet is typically provided with an injection hole on its body, and an explosion-proof component, typically an explosion-proof valve, is positioned near the injection hole. To prevent electrolyte leakage, both the injection hole and the explosion-proof valve must be individually sealed, resulting in high sealing costs for the plain aluminum sheet.

[0020] Based on the above-mentioned bare aluminum sheet, please refer to Figures 1 and 2. Figure 1 is a schematic diagram of the overall structure of a bare aluminum sheet provided in an embodiment of the present application, and Figure 2 is an enlarged schematic diagram of the structure of portion A in Figure 1. The embodiment of the present application provides a bare aluminum sheet, comprising a bare aluminum sheet body 1, a mounting portion and a liquid injection hole 11 provided on the bare aluminum sheet body 1, the mounting portion being configured to mount an explosion-proof component 2, the liquid injection hole 11 being provided on the mounting portion and penetrating the bare aluminum sheet body 1, and the explosion-proof component 2 being located above the liquid injection hole 11.

[0021] It should be noted that the explosion-proof component 2 can be an explosion-proof valve that opens when the internal pressure of the battery cell exceeds a certain threshold, or it can be an explosion-proof plate that ruptures when the internal pressure of the battery cell exceeds a certain threshold, so that during the charging and discharging process of the battery cell, when the internal pressure caused by thermal runaway rises to a certain threshold, the explosion-proof component 2 opens, thereby releasing the pressure inside the battery cell.

[0022] It can be understood that the liquid injection hole 11 is provided at the mounting portion, which can realize the integration (integrated arrangement) of the explosion-proof component 2 and the liquid injection hole 11 , and can save the casting processing procedure.

[0023] The present application sets the injection hole 11 on the mounting portion so that the explosion-proof component 2 is mounted on the mounting portion that is integrated with the injection hole 11, that is, the injection hole is integrated with the mounting portion for mounting the explosion-proof component, thereby eliminating the need for additional perforations on the plain aluminum sheet 1, such as setting an additional mounting portion for the explosion-proof component 2 next to the injection hole 11, that is, generally, leakage-proof designs are made for the explosion-proof component 2 and the injection hole 11 on the plain aluminum sheet 1, for example, by reinforcing the connection method and setting seals at positions that require sealing. Since the explosion-proof component 2 and the injection hole 11 of the present application are integrated, that is, the injection hole is integrated with the mounting portion for mounting the explosion-proof component, it is only necessary to design the mounting portion to prevent leakage of the electrolytic liquid, thereby reducing the number of seals required for the explosion-proof component 2 and the injection hole 11 to prevent leakage of the electrolyte, eliminating the need for sealing rubber particles and sealing nails required to seal the injection hole 11, and then reducing the number of structural components and the assembly process of the corresponding structural components, thereby helping to reduce costs.

[0024] Referring to Figures 2 and 3, Figure 3 is a schematic diagram of the cross-sectional structure of the bare aluminum sheet in Figure 1, and Figure 4 is a schematic diagram of the cross-sectional structure of the bare aluminum sheet equipped with explosion-proof components provided in an embodiment of the present application. In some embodiments of the present application, the mounting portion includes a first sinker 12, which is located on the side of the bare aluminum sheet body 1 located outside the battery, the injection hole 11 is opened at the bottom of the first sinker 12, and the explosion-proof component 2 is installed on the first sinker 12.

[0025] It can be understood that, in the present application, by providing a first sinking platform 12 on one side of the bare aluminum sheet body 1 , it is convenient to fix the explosion-proof component 2 after the explosion-proof component 2 is installed inside the first sinking platform 12 .

[0026] In some embodiments of the present application, the explosion-proof component 2 is an explosion-proof plate, a second sinking platform 13 is formed at the bottom of the first sinking platform 12, the injection hole 11 is opened at the bottom of the second sinking platform 13, and a cavity is formed between the second sinking platform 13 and the explosion-proof component 2.

[0027] It can be understood that the reason why the explosion-proof component 2 is set as an explosion-proof disk instead of an explosion-proof valve is because the explosion-proof disk can make the battery cell shell thin enough, thereby making the total weight of the battery cell light enough.

[0028] It can be understood that the explosion-proof component 2 can be a plate-shaped explosion-proof piece, an arc-shaped explosion-proof piece, or a hemispherical explosion-proof piece.

[0029] The present application is to install the explosion-proof component 2 on the mounting portion above the injection hole 11. After the explosion-proof component 2 is installed on the mounting portion, a cavity is formed with the second sink 13. The injection hole 11 serves as a flow channel between the internal space where the electrolyte of the battery cell is located and the cavity. When the electrolyte inside the battery cell is working normally, the explosion-proof component 2 is not easy to open. When the electrolyte inside the battery cell is in thermal runaway during charging or discharging, the thermal pressure generated inside the battery cell will be evenly dispersed in the cavity through the injection hole 11. In this way, the explosion-proof component 2 can withstand the pressure generated by the thermal runaway inside the battery cell to a certain extent. When the thermal runaway inside the battery cell causes the internal pressure of the battery cell to rise to a certain threshold, the explosion-proof component 2 opens and releases the thermal pressure inside the battery cell. Compared with not setting a cavity, the explosion-proof component 2 is easier to withstand thermal pressure. Without affecting the battery cell breaking through the explosion-proof component 2 due to thermal runaway to release internal pressure, the cavity can raise the thermal pressure tolerance threshold of the explosion-proof component 2.

[0030] 2 and 3 , in some embodiments of the present application, the mounting portion includes a third sinking platform 14 , which is formed at the bottom of the second sinking platform 13 , and the injection hole 11 is opened at the bottom of the third sinking platform 14 .

[0031] The present application provides a third sink 14 on the top surface of the injection hole 11, which helps to release the pressure inside the battery cell more evenly inside the cavity when the battery cell expands due to heat, so as to apply sufficient and uniform force to the bottom of the explosion-proof component 2, thereby enabling the explosion-proof component 2 to withstand higher air pressure, thereby improving the ability of the explosion-proof component 2 to withstand internal pressure. When the explosion-proof component 2 is an explosion-proof disk, the explosion-proof disk can be made thin enough, further saving the material of the explosion-proof disk, reducing the volume occupied by the explosion-proof component 2, and reducing the weight of the explosion-proof component 2.

[0032] 2 and 3 , in some embodiments of the present application, a boss 15 is provided on the bare aluminum sheet body 1 , and the mounting portion is provided on the boss 15 .

[0033] It can be understood that the boss 15 and the edge of the explosion-proof component 2 can be welded, and the welding method can be spot welding or laser welding.

[0034] By arranging a boss 15 around the first sinker 12 on the bare aluminum sheet 1, the present application can weld the inner side of the boss 15 after the explosion-proof component 2 is installed on the first sinker 12. Compared with directly welding the edge of the first sinker 12 to the explosion-proof component 2, the welding is more convenient and the welding connection is better, which further improves the effect of preventing the electrolyte inside the battery cell from leaking to the outside of the battery cell.

[0035] In some embodiments of the present application, an explosion-proof film may be affixed to the surface of the explosion-proof component 2 .

[0036] It should be understood that by sticking an explosion-proof film on the surface of the explosion-proof part 2, the explosion-proof part 2 that is broken into multiple fragments after the explosion can be bonded together, thereby preventing the explosion-proof part 2 from breaking into multiple fragments and scattering everywhere after the explosion. In addition, sticking a film on the explosion-proof part 2 can further seal the gap between the explosion-proof part and the annular recess, preventing the welding seal between the boss 15 and the explosion-proof part 2 from being insufficient, and further preventing the electrolyte inside the battery cell from leaking to the outside of the battery cell.

[0037] 4 , in some embodiments of the present application, the surface of the explosion-proof component 2 is flush with the top surface of the boss 15 .

[0038] The present application can facilitate close adhesion between the explosion-proof component film and the surface of the explosion-proof component 2 by arranging the surface of the explosion-proof component 2 flush with the top surface of the boss 15 .

[0039] 1 to 4 , in some embodiments of the present application, the cavity is cylindrical, and the injection hole 11 is located at the center of the bottom surface of the cavity.

[0040] The present application sets the cavity to a cylindrical shape, and the injection hole 11 is located at the center of the bottom surface of the cavity, so that the high-pressure gas generated by thermal runaway inside the battery cell can be evenly distributed to the entire cavity as quickly as possible.

[0041] Referring to FIG. 3 , in some embodiments of the present application, the bottom edge of the cavity is rounded.

[0042] The present application provides rounded corners on the bottom edge of the cavity, so that the gas generated by thermal runaway of the battery cell can be distributed more evenly when flowing onto the assembled explosion-proof component 2, i.e., the explosion-proof plate.

[0043] In a second aspect, the present application provides a top cover assembly, comprising the above-mentioned smooth aluminum sheet 1.

[0044] In a third aspect, the present application provides a battery cell comprising the above-mentioned top cover assembly.

Claims

1. A plain aluminum sheet, comprising a plain aluminum sheet body, wherein the plain aluminum sheet body (1) is provided with a mounting portion and a liquid injection hole (11), wherein the mounting portion is configured to mount an explosion-proof component (2), wherein the liquid injection hole (11) is disposed on the mounting portion and passes through the plain aluminum sheet body (1), and wherein the explosion-proof component (2) is located above the liquid injection hole (11).

2. The light aluminum sheet according to claim 1, wherein: The mounting portion comprises a first sinker (12), the first sinker (12) being located on the side of the bare aluminum sheet body (1) located outside the battery, the injection hole (11) being opened at the bottom of the first sinker (12), and the explosion-proof component (2) being mounted on the first sinker (12).

3. The light aluminum sheet according to claim 2, wherein: The explosion-proof component (2) is an explosion-proof plate, a second sinking platform (13) is formed at the bottom of the first sinking platform (12), the injection hole (11) is opened at the bottom of the second sinking platform (13), and a cavity is formed between the second sinking platform (13) and the explosion-proof component (2).

4. The light aluminum sheet according to claim 3, wherein: The mounting portion comprises a third sinker (14), the third sinker (14) is formed at the bottom of the second sinker (13), and the injection hole (11) is opened at the bottom of the third sinker (14).

5. The light aluminum sheet according to claim 1, wherein: The smooth aluminum sheet body (1) is provided with a boss (15), and the mounting portion is provided on the boss (15).

6. The light aluminum sheet according to claim 5, wherein: The surface of the explosion-proof component (2) is flush with the top surface of the boss (15).

7. The light aluminum sheet according to claim 3, wherein: The cavity is cylindrical, and the injection hole (11) is located at the center of the bottom surface of the cavity.

8. The light aluminum sheet according to claim 3, wherein: The bottom edge of the cavity is rounded.

9. A top cover assembly comprising the plain aluminum sheet according to any one of claims 1 to 8.

10. A battery cell comprising the top cover assembly according to claim 9.

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