Battery cell housing and battery cell

Abstract

The application discloses an electric core shell and an electric core, and is used for solving the problem that the welding seam between the explosion-proof valves of the existing electric core shell is prone to cracking. The electric core shell comprises a first side wall, a second side wall and an explosion-proof valve. The first side wall and the second side wall are connected and surrounded to form a containing cavity for containing the electric core. The wall thickness of the first side wall is smaller than the wall thickness of the second side wall. The second side wall is provided with a mounting groove penetrating through the second side wall. The explosion-proof valve is arranged in the mounting groove. Therefore, the overall wall thickness of the shell is ensured without affecting the energy density of the electric core. The welding strength between the explosion-proof valve and the shell is improved. The welding seam between the explosion-proof valve and the shell caused by the too small wall thickness of the shell can be effectively avoided.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a cell housing and a cell. Background Technology

[0002] The battery cell casing mainly consists of a casing and a cover plate. The casing and cover plate enclose a sealed space to accommodate the battery cell. However, the external dimensions of the battery cell have specified technical requirements. Therefore, the wall thickness of the casing will directly affect the energy density of the battery cell. Moreover, in order to improve safety, an explosion-proof valve is usually installed on the casing to discharge the high-pressure gas inside the casing.

[0003] In the relevant existing technologies, the battery cell casing has a uniform wall thickness structure. When the casing wall thickness is too large, it greatly compresses the internal space of the casing, thereby affecting the energy density of the battery cell. When the casing wall thickness is too small, it seriously affects the welding strength between the casing and the explosion-proof valve. Moreover, because the casing wall thickness is too small, it is also easy to form weld seams at the welding point, which are prone to cracking and failure under long-term cyclic loads or extreme working conditions, posing a safety hazard.

[0004] Therefore, the weld between the existing battery cell casing and the explosion-proof valve is prone to cracking. Utility Model Content

[0005] The purpose of this application is to provide a battery cell housing and a battery cell to solve the problem that the weld between the existing battery cell housing and the explosion-proof valve is prone to cracking.

[0006] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0007] On one hand, this application provides a battery cell housing, including a first sidewall, a second sidewall, and an explosion-proof valve. The first sidewall and the second sidewall are connected and enclosed to form a cavity for accommodating the battery cell. The wall thickness of the first sidewall is less than the wall thickness of the second sidewall. The second sidewall is provided with a mounting groove that passes through the second sidewall. The explosion-proof valve is disposed in the mounting groove.

[0008] In some embodiments, the difference between the wall thickness of the second sidewall and the wall thickness of the first sidewall is greater than 0.45 mm.

[0009] In some embodiments, the area of ​​the first sidewall is greater than the area of ​​the second sidewall.

[0010] In some embodiments, the first sidewall and the second sidewall are integrally formed by stamping, and an arc-shaped transition portion is provided between the first sidewall and the second sidewall.

[0011] In some embodiments, the first sidewall, the second sidewall, and the arcuate transition portion are made of aluminum.

[0012] In some embodiments, the mounting groove includes a groove segment and a through hole, wherein the width of the groove segment is greater than the width of the through hole, and the explosion-proof valve is disposed in the groove segment.

[0013] In some embodiments, the groove segment includes a first sub-groove and a first arc-shaped transition groove, the first arc-shaped transition groove being connected to both ends of the first sub-groove, and the shape of the explosion-proof valve being adapted to the groove segment.

[0014] In some embodiments, the depth of the groove segment is less than 0.55 mm.

[0015] In some embodiments, the wall thickness of the explosion-proof valve is less than 0.4 mm.

[0016] On the other hand, this application provides a battery cell, which includes the battery cell housing provided in any of the foregoing embodiments.

[0017] This application has the following beneficial effects:

[0018] The battery cell housing provided in this application includes a first sidewall, a second sidewall, and an explosion-proof valve. The first and second sidewalls are connected and enclose a cavity for accommodating the battery cell. The thickness of the first sidewall is designed to be less than that of the second sidewall. A mounting groove penetrating the second sidewall is provided, and the explosion-proof valve is disposed in the mounting groove. By designing the battery cell housing with an unequal wall thickness structure and placing the explosion-proof valve in the mounting groove of the thickened second sidewall, the overall wall thickness of the housing is ensured to effectively improve the welding strength between the explosion-proof valve and the housing without affecting the energy density of the battery cell. Furthermore, it effectively avoids the problem of weld cracking between the explosion-proof valve and the housing due to insufficient housing wall thickness. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the battery cell housing structure in an embodiment of this application;

[0020] Figure 2 An exploded view of the battery cell housing is provided for the embodiments of this application;

[0021] Figure 3 for Figure 2 Enlarged view of section A;

[0022] Figure 4 This is a schematic diagram of the explosion-proof valve in the embodiments of this application.

[0023] Figure label:

[0024] 10 - First sidewall;

[0025] 20 - Second sidewall;

[0026] 21-Mounting slot;

[0027] 211 trench section;

[0028] 2111 - First sub-slot;

[0029] 2112 - First arc-shaped transition groove;

[0030] 212 - Through hole;

[0031] 2121 - Straight line segment;

[0032] 2122 - Arc-shaped transition section;

[0033] 213 - Steps;

[0034] 30-Arc-shaped transition section

[0035] 40 - Receptacle;

[0036] 50 - Explosion-proof valve;

[0037] 51-Ontology;

[0038] 52 - Thinning zone. Detailed Implementation

[0039] The following specific embodiments illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification.

[0040] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present application will now be described in detail with reference to the accompanying drawings and embodiments. To enable those skilled in the art to better understand the solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0041] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element; for example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0042] It should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0043] In the embodiments of this application, the words "exemplary" or "for example" are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs; rather, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0044] Existing battery cell casings are typically of uniform wall thickness. When the casing wall thickness is too large, it significantly compresses the internal space of the casing, thereby affecting the energy density of the battery cell. Conversely, when the casing wall thickness is too small, it severely affects the welding strength between the casing and the explosion-proof valve. Furthermore, because the casing wall thickness is too small, weld seams are easily formed at the welding points, which are prone to cracking and failure under long-term cyclic loads or extreme working conditions, posing a safety hazard.

[0045] Therefore, existing cell casings are no longer able to meet the multiple requirements of cell energy density, mechanical strength, and safety stability, and have become a bottleneck restricting the development of battery technology.

[0046] To address the aforementioned technical problems, one aspect of this application provides a battery cell housing. Figure 1 This is a schematic diagram of the battery cell housing structure in an embodiment of this application. Figure 2 An exploded view of the battery cell casing is provided for the embodiments of this application. Figure 3 for Figure 2 Enlarged view of section A.

[0047] like Figure 1 and Figure 2 As shown, in some embodiments, the battery cell housing may include a first sidewall 10, a second sidewall 20, and an explosion-proof valve 50. The first sidewall 10 and the second sidewall 20 are connected and enclosed to form a receiving cavity 40 for accommodating the battery cell. The wall thickness of the first sidewall 10 may be less than the wall thickness of the second sidewall 20. The second sidewall 20 is provided with a mounting groove 21 that penetrates the second sidewall 20. The explosion-proof valve 50 may be disposed in the mounting groove 21.

[0048] like Figures 1 to 3 As shown, the first sidewall 10 and the second sidewall 20 can be connected by welding, or they can be an integral structure. For example, the first sidewall 10 and the second sidewall 20 can be integrally formed by stamping or extrusion drawing. The first sidewall 10 can be a front sidewall or a rear sidewall. The second sidewall 20 can be an upper sidewall or a lower sidewall.

[0049] like Figure 2 As shown, the mounting groove 21 can be formed by punching holes in the second side wall 20 through a stamping process, and the depth of the mounting groove 21 can penetrate the second side wall 20. The shape of the explosion-proof valve 50 can be adapted to the mounting groove 21, and the explosion-proof valve 50 can be fixedly connected to the mounting groove 21 by welding. It should be noted that the depth of the mounting groove 21 penetrating the second side wall 20 means that the mounting groove 21 can penetrate the entire thickness of the second side wall 20.

[0050] For example, the first sidewall 10 and the second sidewall 20 may be made of aluminum, and the explosion-proof valve 50 may be made of aluminum.

[0051] In this embodiment, the battery cell housing is designed to include a first sidewall 10, a second sidewall 20, and an explosion-proof valve 50. The first sidewall 10 and the second sidewall 20 are connected and enclosed to form a receiving cavity 40 for accommodating the battery cell. The wall thickness of the first sidewall 10 is designed to be smaller than the wall thickness of the second sidewall 20. An installation groove 21 is provided on the second sidewall 20, and the explosion-proof valve 50 is disposed in the installation groove 21.

[0052] By designing the battery cell housing with an unequal wall thickness structure and placing the explosion-proof valve 50 in the mounting groove 21 of the thickened second side wall 20, the overall wall thickness of the housing is ensured to effectively improve the welding strength between the explosion-proof valve 50 and the housing without affecting the energy density of the battery cell. This also effectively avoids the problem of weld seams forming between the explosion-proof valve 50 and the housing due to insufficient housing wall thickness, enabling the battery cell housing to meet the technical requirements of balancing battery cell energy density, mechanical strength, and safety stability.

[0053] like Figure 1 As shown in the embodiment of this application, since the battery cell casing is designed with an unequal wall thickness structure, that is, the wall thickness of the first sidewall 10 is less than the wall thickness of the second sidewall 20, in order to reduce the manufacturing difficulty of the casing, the difference between the wall thickness of the second sidewall 20 and the wall thickness of the first sidewall 10 can be designed to be greater than 0.45mm, and the area of ​​the first sidewall 10 is designed to be greater than the area of ​​the second sidewall 20. For example, the outer area of ​​the first sidewall 10 is greater than the outer area of ​​the second sidewall 20.

[0054] Based on this structure, it is easier to weld the explosion-proof valve 50 on the second sidewall 20, and the thickened second sidewall 20 can further improve the structural strength of the connection between the second sidewall 20 and the explosion-proof valve 50.

[0055] Meanwhile, by designing the area of ​​the first sidewall 10 to be larger than the area of ​​the second sidewall 20, and simultaneously placing the explosion-proof valve 50 on the second sidewall 20, the inventors of this application can effectively reduce the impact of the overall thickness of the casing on the energy density of the battery cell. It is understood that because the area of ​​the first sidewall 10 is designed to be larger than the area of ​​the second sidewall 20, and the thickness of the first sidewall 10 is less than the thickness of the second sidewall 20, this structural design allows the larger area of ​​the first sidewall 10 to form the main component of the accommodating cavity 40 for housing the battery cell. This further effectively reduces the adverse effects of the overall wall thickness of the casing on the accommodating space of the low-density battery cell, thereby effectively reducing the negative impact of the overall wall thickness of the casing on the energy density of the battery cell.

[0056] like Figure 1 and Figure 2 As shown, an arc-shaped transition portion 30 can be provided between the first sidewall 10 and the second sidewall 20. Based on this structure, a transition connection can be formed between the first sidewall 10 and the second sidewall 20, which can further reduce the processing difficulty of the shell and improve the connection strength between the first sidewall 10 and the second sidewall.

[0057] For example, the arcuate transition portion 30 may be made of aluminum.

[0058] like Figure 3As shown, in some embodiments, the mounting groove 21 may include a groove segment 211 and a through hole 212, the groove width of the groove segment 211 is greater than the width of the through hole 212, and the explosion-proof valve 50 is disposed in the groove segment 211.

[0059] Specifically, the groove segment 211 and the through hole 212 are connected. Since the width of the groove segment 211 is greater than the width of the through hole 212, a step 213 is formed at the connection between the groove segment 211 and the through hole 212. The formation of this step 213 facilitates the welding of the explosion-proof valve 50 into the groove segment 211. It can be understood that when welding the explosion-proof valve 50, it can be placed in the groove segment 211, with the ground of the explosion-proof valve 50 abutting against the step 213, thus providing support for the explosion-proof valve 50.

[0060] For example, the shape of the mounting slot 21 can be a circular hole or a square hole, or a combination of a circular hole and a square hole.

[0061] For example, such as Figure 3 As shown, when the shape of the mounting groove 21 is a combination of a circular hole and a square hole, the mounting groove 21 may include a groove segment 211 and a through hole 212. The shape of the explosion-proof valve 50 is adapted to the groove segment 211. The groove segment 211 may include a first sub-groove 2111 and a first arc-shaped transition groove 2112. The first arc-shaped transition groove 2112 is connected to both ends of the first sub-groove 2111, so that the groove segment 211 can form a square groove and a circular groove.

[0062] Based on this structure, when the groove segment 211 is formed with square and circular grooves, it is convenient to place the explosion-proof valve 50 in the groove segment 211; at the same time, it can improve the field of vision of the groove segment 211, and make it easy to observe whether there is a gap between the explosion-proof valve 50 and the groove segment 211 during welding.

[0063] The through hole 212 may include a straight segment 2121 and an arc-shaped transition segment 2122. The arc-shaped transition segment 2122 is connected to both ends of the straight segment 2121, allowing the through hole 212 to form both square and circular holes. This makes the shape of the through hole 212 similar to that of the groove segment 211, further reducing the machining difficulty of the groove segment 211 and the through hole 212. It is understood that because the shape of the through hole 212 is similar to that of the groove segment 211, the groove segment 211 and the through hole 212 can be machined using the same or similar stamping processes, reducing the design difficulty of the machining process.

[0064] In this embodiment, the sum of the depth of the groove 211 and the depth of the through hole 212 is equal to the thickness of the second sidewall 20. In some embodiments, the depth of the groove 211 may be less than 0.55 mm. It is understood that the depth of the groove 211 refers to the depth relative to the surface of the second sidewall 20. Based on this structure, the processing difficulty of the groove 211 can be further reduced.

[0065] In some embodiments, the wall thickness of the explosion-proof valve 50 can be less than 0.4 mm. It is understood that the actual welding process between the explosion-proof valve 50 and the groove section 211 may produce welding bulges, which may exist on the upper surface of the second side wall 20 and affect the aesthetics. To address this problem, the inventors of this application designed the wall thickness of the explosion-proof valve 50 to be less than 0.4 mm, so that the wall thickness of the explosion-proof valve 50 is less than the depth of the groove section 211. This allows the upper surface of the explosion-proof valve 50 to be embedded in the groove section 211, so that the welding bulges produced during the welding process are embedded below the outer surface of the second side wall 20, achieving an aesthetically pleasing effect.

[0066] Figure 4 This is a schematic diagram of the explosion-proof valve in an embodiment of this application, as shown below. Figure 4 As shown, the explosion-proof valve 50 may include a body 51 and a thinning zone 52. The body 51 is disposed around the thinning zone 52, and the body 51 is a thickened area, which allows the thickened body 51 to form good welding strength with the groove section 211. It can be understood that, in order to improve the safety performance of the battery cell housing, the explosion-proof valve 50 is designed to include the thinning zone 52, that is, the thickness of the thinning zone 52 is less than the thickness of the body 51. When the pressure inside the battery cell housing reaches a predetermined pressure, the thinning zone 52 can rupture, thereby achieving an explosion-proof effect.

[0067] For example, the thickness of the thinning region 52 can be gradually reduced from the edge of the thinning region 52 to the center of the thinning region 52.

[0068] It is understood that, in this embodiment of the application, the thickness of the body 51 can be the wall thickness of the aforementioned explosion-proof valve 50.

[0069] Another aspect of the embodiments of this application provides a battery cell, which includes the battery cell housing provided in any of the foregoing embodiments.

[0070] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. All embodiments obtained by any modifications, alterations or equivalent substitutions made by those skilled in the art without departing from the technical concept of this application shall fall within the scope of protection of the claims of this application.

Claims

1. A battery cell housing, characterized in that, It includes a first sidewall, a second sidewall, and an explosion-proof valve. The first sidewall and the second sidewall are connected and enclosed to form a cavity for accommodating the battery cell. The wall thickness of the first sidewall is less than that of the second sidewall. The second sidewall is provided with a mounting groove that passes through the second sidewall. The explosion-proof valve is disposed in the mounting groove.

2. The cell housing according to claim 1, characterized in that, The difference between the wall thickness of the second sidewall and the wall thickness of the first sidewall is greater than 0.45 mm.

3. The cell housing according to claim 1, characterized in that, The area of ​​the first sidewall is greater than the area of ​​the second sidewall.

4. The cell housing according to claim 1, characterized in that, The first sidewall and the second sidewall are integrally formed by stamping, and an arc-shaped transition section is provided between the first sidewall and the second sidewall.

5. The cell housing according to claim 4, characterized in that, The first sidewall, the second sidewall, and the arc-shaped transition portion are made of aluminum.

6. The cell housing according to claim 1, characterized in that, The mounting groove includes a groove segment and a through hole. The width of the groove segment is greater than the width of the through hole, and the explosion-proof valve is disposed in the groove segment.

7. The cell housing according to claim 6, characterized in that, The groove segment includes a first sub-groove and a first arc-shaped transition groove. The first arc-shaped transition groove is connected to both ends of the first sub-groove. The shape of the explosion-proof valve is adapted to the groove segment.

8. The cell housing according to claim 6, characterized in that, The depth of the groove is less than 0.55 mm.

9. The cell housing according to claim 6, characterized in that, The explosion-proof valve has a wall thickness of less than 0.4 mm.

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

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