Battery cell

Abstract

The utility model provides a battery cell, which comprises: a shell having an open end, the shell being provided with a first section and a second section in sequence in the height direction, the first section being close to the open end; the first section is thicker than the second section; the cover plate assembly covers the opening end, and an accommodating space is defined by the cover plate assembly and the shell; the cover plate assembly comprises a cover plate body connected with the first section and an insulating part connected to the side, close to the containing space, of the cover plate body. In the height direction of the shell, the distance from the edge, close to the first section, of the second section to the opening end is L1, the distance from the surface, away from the cover plate body, of the insulating part to the opening end is L2, and L1 is larger than L2. According to the battery cell provided by the invention, the risk of deformation of the opening end of the shell in the processing process can be reduced by arranging the first section with relatively thick thickness; and by arranging the second section with relatively thin thickness, the weight of the shell and the preparation cost of the battery cell can be reduced, so that a lightweight effect is achieved.

Description

Technical Field

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

[0002] The battery cell includes a housing with an open end and a cover plate assembly that fits over the open end. In order to reduce the weight of the battery cell and manufacturing costs, the overall thickness of the housing is designed to be relatively thin in related technologies.

[0003] However, the applicant discovered that when the shell thickness is too thin, the opening end may deform during processing, resulting in wavy edges, which would adversely affect the fit and welding strength between the shell and the cover plate assembly. Utility Model Content

[0004] In view of this, the purpose of this application is to propose a battery cell that solves some or all of the aforementioned technical problems.

[0005] To achieve the above objectives, this application provides a battery cell, comprising: a housing having an open end, wherein the housing is provided with a first segment and a second segment in sequence along its height direction, the first segment being close to the open end; the thickness of the first segment being greater than the thickness of the second segment; a cover plate assembly covering the open end and forming an accommodating space with the housing; the cover plate assembly including a cover plate body connected to the first segment and an insulating member connected to the side of the cover plate body near the accommodating space; wherein, along the height direction of the housing, the distance from the edge of the second segment near the first segment to the open end is L1, and the distance from the surface of the insulating member away from the cover plate body to the open end is L2, where L1 > L2.

[0006] Optionally, a bare battery cell is disposed in the accommodating space, the bare battery cell including a battery cell body; along the height direction of the housing, the edge of the second segment near the first segment is located on the side of the battery cell body near the insulating member.

[0007] Optionally, the first segment includes a first upper segment and a transition segment arranged sequentially along the height direction of the housing. The transition segment is connected to the second segment, and the first upper segment is connected to the side of the transition segment away from the second segment. The thickness of the transition segment gradually increases from the second segment to the first upper segment.

[0008] Optionally, the difference between the thickness of the first upper segment and the thickness of the second segment is 0.3 mm.

[0009] Optionally, the first upper segment extends along the height direction of the housing to the opening end, and the extension length of the first upper segment is L3, where L3 ≥ 0.5 mm.

[0010] Optionally, the inner side of the transition section is configured as an inclined surface that is directly connected to the inner side of the first upper section and the inner side of the second section, respectively; wherein, the inner side is the side of the housing near the receiving space.

[0011] Optionally, the length of the transition section along the height direction of the shell is L4, where L4 ≥ 0.3 mm.

[0012] Optionally, a battery cell body is disposed in the accommodating space; along the height direction of the housing, the transition section is located between the insulating member and the battery cell body.

[0013] Optionally, the housing includes two first side plates disposed opposite each other along a first direction and two second side plates disposed opposite each other along a second direction; the surface area of ​​the first side plate is larger than the surface area of ​​the second side plate, and the first segment and the second segment are disposed at least on the first side plate; the first direction, the second direction and the height direction of the housing are mutually perpendicular.

[0014] Optionally, the outer side of the first segment coincides with the outer side of the second segment, wherein the outer side is the side of the housing that is away from the receiving space.

[0015] As can be seen from the above, the battery cell provided in this application, by setting a thicker first segment, can reduce the risk of deformation at the open end of the casing during processing; by setting a thinner second segment, it can reduce the weight of the casing and the manufacturing cost of the battery cell, thus achieving a lightweight effect. Simultaneously, by limiting the distance L1 from the edge of the second segment near the first segment to the open end, and the distance L2 from the surface of the insulating component away from the cover plate body to the open end, to L1 > L2, the dimension of the first segment along the height direction of the casing can be larger, further ensuring that the open end will not deform. This ensures a strong connection between the casing and the cover plate body, contributing to improved sealing and safety of the battery cell. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a partial top view schematic diagram of the battery cell according to an embodiment of this application;

[0018] Figure 2 for Figure 1 Schematic diagram of the cross section AA;

[0019] Figure 3 for Figure 2 Enlarged schematic diagram of part B.

[0020] Explanation of reference numerals in the attached figures:

[0021] 100. Shell; 110. Open end; 120. First section; 121. First upper section; 122. Transition section; 130. Second section; 140. Bottom plate; 150. First side plate; 160. Second side plate;

[0022] 200. Cover plate assembly; 210. Cover plate body; 220. Insulating component; 230. Terminal post;

[0023] 300. Accommodation space;

[0024] 400. Bare battery cell; 410. Battery cell body. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0026] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components described in these embodiments do not limit the scope of this application.

[0027] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0028] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0029] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0030] Figure 1 This shows a partial top-view diagram of the battery cell. Figure 2 Showing Figure 1 A schematic diagram of the cross-section AA in the middle. Figure 3 Showing Figure 2 Enlarged schematic diagram of part B.

[0031] like Figure 1 , Figure 2 and Figure 3 The battery cell provided in this application embodiment includes: a housing 100 having an open end 110, the housing 100 in its height direction (e.g., Figure 2 and Figure 3 A first segment 120 and a second segment 130 are sequentially arranged in the Z direction of the housing 100. The first segment 120 is close to the opening end 110. The thickness of the first segment 120 is greater than the thickness of the second segment 130. A cover plate assembly 200 is fitted onto the opening end 110 and surrounds the housing 100 to form an accommodating space 300. The cover plate assembly 200 includes a cover plate body 210 connected to the first segment 120 and an insulating member 220 connected to the side of the cover plate body 210 near the accommodating space 300. Along the height direction of the housing 100, the distance from the edge of the second segment 130 near the first segment 120 to the opening end 110 is L1, and the distance from the surface of the insulating member 220 away from the cover plate body 210 to the opening end 110 is L2, where L1 > L2.

[0032] For example, housing 100 can be an aluminum housing or a steel housing.

[0033] For example, the top of the housing 100 is configured as an open end 110.

[0034] For example, the insulating element 220 may be a plastic part.

[0035] For example, the cover body 210 may be welded to the first segment 120 of the housing 100.

[0036] The housing 100 includes a first segment 120 and a second segment 130 connected vertically. Because the first segment 120 is close to the opening end 110 and needs to connect to the cover plate body 210, its thickness is made relatively thick. This avoids wavy edges during processing due to a thin housing 100, thus ensuring the connection strength between the first segment 120 and the cover plate body 210. For the second segment 130, which is farther from the opening end 110, even if its thickness is made relatively thin, it will not adversely affect the connection between the housing 100 and the cover plate body 210. Therefore, in this embodiment, making the second segment 130 thinner not only reduces the cell weight and manufacturing cost but also helps to expand the accommodating space 300, allowing the cell to have a higher energy density.

[0037] However, to achieve the aforementioned beneficial effects, the positions of the first segment 120 and the second segment 130 need to be reasonably set. If L1≤L2, the second segment 130 will extend too close to the opening end 110, resulting in the first segment 120 having an excessively small dimension along the height direction of the housing 100. During the processing of the housing 100, the opening end 110 may still deform, potentially reducing the connection strength between the housing 100 and the cover plate body 210. Therefore, in this embodiment, L1 and L2 are limited to L1>L2, allowing the first segment 120 to have a larger dimension along the height direction of the housing 100, sufficient to ensure that the opening end 110 does not deform during the processing of the housing 100.

[0038] The battery cell provided in this application embodiment, by providing a thicker first segment 120, can reduce the risk of deformation of the open end 110 of the housing 100 during processing; by providing a thinner second segment 130, it can reduce the weight of the housing 100 and the manufacturing cost of the battery cell, thereby achieving a lightweight effect. Simultaneously, by limiting the distance L1 from the edge of the second segment 130 near the first segment 120 to the open end 110, and the distance L2 from the surface of the insulating member 220 away from the cover plate body 210 to the open end 110, to L1 > L2, the first segment 120 can be made larger in the height direction of the housing 100, further ensuring that the open end 110 will not deform, thereby ensuring a strong connection between the housing 100 and the cover plate body 210, which helps to improve the sealing and safety of the battery cell.

[0039] like Figure 2 and Figure 3 In some embodiments, a bare battery cell 400 is disposed in the accommodating space 300, the bare battery cell 400 including a battery cell body 410; along the height direction of the housing 100, the edge of the second segment 130 near the first segment 120 is located on the side of the battery cell body 410 near the insulating member 220.

[0040] For example, the cover plate assembly 200 also includes a terminal post 230 penetrating the cover plate body 210 and the insulator 220. The terminal post 230 may include a positive terminal post and a negative terminal post, and the terminal post 230 is insulated and sealed to the cover plate body 210.

[0041] For example, the cell body 410 includes a plurality of positive electrode plates, a plurality of negative electrode plates, and a separator separating the positive and negative electrode plates. The positive electrode plates, negative electrode plates, and separator can form a stacked structure or a wound structure. A portion of each positive electrode plate extends out of the cell body 410 to form a positive tab, which is electrically connected to a positive terminal. A portion of each negative electrode plate extends out of the cell body 410 to form a negative tab, which is electrically connected to a negative terminal.

[0042] by Figure 3Taking the structure and orientation shown as an example, the insulating component 220 is located above the cell body 410, that is, the top surface of the cell body 410 faces the insulating component 220. If the second segment 130 is close to the edge of the first segment 120, that is, the upper edge of the second segment 130 is below the top surface of the cell body 410, then a portion of the first segment 120 may extend downward to a position corresponding to the cell body 410. In this case, the first segment 120 may compress the cell body 410 (especially the negative electrode sheet inside the cell body 410), causing pressure damage to the bare cell 400.

[0043] Therefore, in this embodiment, the edge of the second segment 130 near the first segment 120 is defined on the side of the cell body 410 near the insulating member 220, that is, the upper edge of the second segment 130 is defined above the top surface of the cell body 410, so as to ensure that the entire cell body 410 corresponds to the thinner second segment 130. This can make the gap between the cell body 410 and the housing 100 larger, thereby effectively preventing the housing 100 from squeezing the cell body 410 and helping to extend the service life of the cell.

[0044] like Figure 3 In some embodiments, the first segment 120 includes a first upper segment 121 and a transition segment 122 arranged sequentially along the height direction of the housing 100. The transition segment 122 is connected to the second segment 130, and the first upper segment 121 is connected to the side of the transition segment 122 away from the second segment 130. The thickness of the transition segment 122 gradually increases from the second segment 130 to the first upper segment 121.

[0045] For example, the first upper segment 121 and the transition segment 122 can be integrally formed or welded together.

[0046] For example, the second segment 130 and the transition segment 122 can be integrally formed or welded together.

[0047] For example, the thickness of the transition segment 122 can be continuously varied or gradually varied. When the thickness of the transition segment 122 is continuously varied, the surface of the transition segment 122 is constructed as a smooth inclined surface or a curved surface; when the thickness of the transition segment 122 is gradually varied, the surface of the transition segment 122 is constructed as a stepped surface or a step-like surface.

[0048] The transition section 122 facilitates the thickness transition between the first upper section 121 and the second section 130, strengthening the connection between them. This prevents stress concentration at the junction of the two sections due to abrupt changes in thickness, which could negatively impact the mechanical strength of the casing 100. Simultaneously, it enhances the safety of the battery cell and extends its lifespan.

[0049] like Figure 3 In some embodiments, the difference between the thickness d1 of the first upper segment 121 and the thickness d2 of the second segment 130 is 0.3 mm.

[0050] If the difference between d1 and d2 is too large, stress concentration may occur at the position between the first upper segment 121 and the second segment 130. During the processing of the housing 100, the assembly of the battery cell, and transportation, cracks may appear at the aforementioned position of the housing 100, which may adversely affect the sealing and safety of the battery cell. If the difference between d1 and d2 is too small, there may be two situations: the thickness of the first upper segment 121 is too thin or the thickness of the second segment 130 is too thick. When the thickness of the first upper segment 121 is too thin, the open end 110 may still be at risk of deformation during the processing of the housing 100. When the thickness of the second segment 130 is too thick, the weight reduction and cost reduction effect of the battery cell is not obvious.

[0051] Therefore, in this embodiment, the difference between d1 and d2 is limited to 0.3mm, which can effectively reduce the risk of deformation at the open end 110 and also achieve a significant cost reduction and weight reduction effect on the battery cell.

[0052] like Figure 3 In some embodiments, the first upper segment 121 extends along the height direction of the housing 100 to the opening end 110, and the extension length of the first upper segment 121 is L3, where L3 ≥ 0.5 mm.

[0053] For example, in order to meet the requirements of lightweight battery cells, L3 can be limited to 0.5mm≤L3≤1.0mm, specifically 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, and 1.0mm.

[0054] For example, the thickness of the first upper segment 121 is uniform.

[0055] Since a transition section 122 is provided between the second section 130 and the first upper section 121, if only the position of the second section 130 is limited, the transition section 122 may also excessively encroach on the space of the first upper section 121 on the housing 100, resulting in the first upper section 121 having insufficient dimensions along the height direction of the housing 100.

[0056] To avoid the above situation, this embodiment limits L3. If L3 < 0.5 mm, the opening end 110 still has the risk of deformation during the processing of the housing 100, which may reduce the connection strength between the housing 100 and the cover plate body 210. Therefore, this embodiment limits L3 so that the extension length of the first upper segment 121 is sufficient to ensure that the opening end 110 will not deform during the processing of the housing 100.

[0057] like Figure 2 and Figure 3 In some embodiments, the inner side of the transition section 122 is configured as an inclined surface that is directly connected to the inner side of the first upper section 121 and the inner side of the second section 130, respectively; wherein the inner side is the side of the housing 100 near the receiving space 300.

[0058] In this embodiment, the inner surfaces of the first upper segment 121, the second segment 130, and the transition segment 122 form a continuous surface, and the inner surface of the transition segment 122 is constructed as a smooth inclined surface, which helps to reduce the processing difficulty of the transition segment 122 and reduce the processing cost of the housing 100. At the same time, it can also avoid sharp edges on the inner surface of the transition segment 122 due to its stepped surface, thus preventing scratches to the bare battery cell 400 or the insulating component 220 by the inner surface of the transition segment 122 during battery cell assembly and use.

[0059] like Figure 3 In some embodiments, the dimension of the transition section 122 along the height direction of the housing 100 is L4, where L4 ≥ 0.3 mm.

[0060] For example, in order to ensure that the length of the second segment 130 can be designed reasonably to take into account the lightweight requirements of the battery cell, L4 can be limited to 0.3mm≤L4≤1.0mm, specifically 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm.

[0061] If L4 is too small, the effect of the thickness transition of the transition segment 122 will not be significant, and stress concentration may still occur between the first upper segment 121 and the second segment 130. To avoid the above problem, this embodiment limits L4 so that the thicker first upper segment 121 and the thinner second segment 130 can transition more smoothly, effectively preventing stress concentration between the first upper segment 121 and the second segment 130, further ensuring the mechanical strength of the casing 100 and improving the safety of the battery cell.

[0062] like Figure 3 In some embodiments, the transition section 122 is located between the insulator 220 and the cell body 410 along the height direction of the housing 100.

[0063] Based on the foregoing, the thickness of the transition section 122 is less than that of the first upper section 121 and greater than that of the second section 130. If the position of the transition section 122 corresponds to the main body of the battery cell 410, its greater thickness may cause compression to the main body of the battery cell 410. If the position of the transition section 122 corresponds to the insulating component 220, it may encroach on the setting space of the first upper section 121, which may cause the shell 100 to still have the risk of deformation of the opening end 110 during the processing.

[0064] Therefore, in this embodiment, the transition section 122 is set between the insulating member 220 and the cell body 410, which can prevent the transition section 122 from squeezing the cell body 410 and avoid the electrode in the cell body 410 from being compressed and causing the active material to fall off; it can also make the first upper section 121 have sufficient setting space to ensure that the shell 100 will not deform at the open end 110 during the processing.

[0065] like Figure 1 In some embodiments, the housing 100 includes a first direction (e.g., Figure 1 Two first side plates 150 are arranged opposite each other in the X direction, and along the second direction (e.g., Figure 1 Two second side plates 160 are arranged opposite each other in the Y direction; the surface area of ​​the first side plate 150 is larger than the surface area of ​​the second side plate 160, and the first segment 120 and the second segment 130 are at least provided on the first side plate 150; the first direction, the second direction and the height direction of the shell 100 are perpendicular to each other.

[0066] For example, such as Figure 2 and Figure 3 The housing 100 also includes a base plate 140, which is disposed opposite to the opening end 110. The two first side plates 150 and the two second side plates 160 are all connected to the base plate 140. The accommodating space 300 is the space formed by the insulating member 220, the base plate 140, the two first side plates 150 and the two second side plates 160.

[0067] It should be noted that the surface area of ​​the first side plate 150 can be the side surface area of ​​the first side plate 150 near the bare cell 400. Similarly, the surface area of ​​the second side plate 160 can be the side surface area of ​​the second side plate 160 near the bare cell 400.

[0068] For example, the first segment 120 and the second segment 130 are simultaneously disposed on the first side plate 150 and the second side plate 160.

[0069] Since the first side plate 150 has a large surface area, the first segment 120 and the second segment 130 are at least provided on the first side plate 150. On the one hand, this allows the thicker first segment 120 to have a larger installation area on the housing 100, which has a correspondingly greater impact on the strength of the area of ​​the housing 100 near the opening end 110, and can further prevent deformation of the opening end 110. On the other hand, it also allows the thinner second segment 130 to have a larger installation area on the housing 100, which can improve the cost reduction and weight reduction effect, and also allows more space in the housing space 300 to accommodate the bare battery cell 400, which helps to further improve the energy density of the battery cell.

[0070] like Figure 3 In some embodiments, the outer side of the first segment 120 coincides with the outer side of the second segment 130, wherein the outer side is the side of the housing 100 away from the receiving space 300.

[0071] In this embodiment, the outer side of the housing 100 is a smooth side, that is, the flatness of its outer side is not affected by the thinning design of the housing 100. The thinning design is only carried out on the inner side of the housing 100. The smooth and flat outer side of the housing 100 is conducive to the housing 100 resisting the impact force from the outside, and facilitates the assembly and transportation of the battery cell.

[0072] It should be noted that some embodiments of this application have been described above. Other embodiments are within the scope of the appended claims.

[0073] The various embodiments in this application are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0074] The description in this application is given for illustrative purposes and is not intended to be exhaustive or to limit the application to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of this application and to enable those skilled in the art to understand this application and design various embodiments with various modifications suitable for a particular purpose.

[0075] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application is limited to these examples; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0076] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0077] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: A housing having an open end, the housing having a first segment and a second segment sequentially arranged in its height direction, the first segment being close to the open end; the thickness of the first segment being greater than the thickness of the second segment; A cover plate assembly is fitted onto the opening end and surrounds the housing to form an accommodating space; the cover plate assembly includes a cover plate body connected to the first section, and an insulating member connected to the cover plate body on the side near the accommodating space; Wherein, along the height direction of the housing, the distance from the edge of the second segment near the first segment to the opening end is L1, and the distance from the surface of the insulating member away from the cover plate body to the opening end is L2, where L1 > L2.

2. The battery cell according to claim 1, characterized in that, A bare battery cell is disposed in the accommodating space. The bare battery cell includes a battery cell body. Along the height direction of the housing, the edge of the second segment near the first segment is located on the side of the battery cell body near the insulating member.

3. The battery cell according to claim 1, characterized in that, The first segment includes a first upper segment and a transition segment arranged sequentially along the height direction of the shell. The transition segment is connected to the second segment, and the first upper segment is connected to the side of the transition segment away from the second segment. The thickness of the transition segment gradually increases from the second segment to the first upper segment.

4. The battery cell according to claim 3, characterized in that, The difference between the thickness of the first upper segment and the thickness of the second segment is 0.3 mm.

5. The battery cell according to claim 3, characterized in that, The first upper segment extends along the height direction of the shell to the opening end, and the extension length of the first upper segment is L3, where L3 ≥ 0.5 mm.

6. The battery cell according to claim 3, characterized in that, The inner side of the transition section is configured as an inclined surface that is directly connected to the inner side of the first upper section and the inner side of the second section, respectively; wherein, the inner side is the side of the housing near the receiving space.

7. The battery cell according to claim 3, characterized in that, The length of the transition section along the height direction of the shell is L4, and L4 ≥ 0.3 mm.

8. The battery cell according to claim 3, characterized in that, The housing contains a battery cell body; along the height direction of the housing, the transition section is located between the insulating member and the battery cell body.

9. The battery cell according to claim 1, characterized in that, The housing includes two first side plates arranged opposite each other along a first direction, and two second side plates arranged opposite each other along a second direction; the surface area of ​​the first side plates is larger than the surface area of ​​the second side plates, and the first segment and the second segment are at least disposed on the first side plates; the first direction, the second direction and the height direction of the housing are mutually perpendicular.

10. The battery cell according to claim 1, characterized in that, The outer side of the first segment coincides with the outer side of the second segment, wherein the outer side is the side of the housing that is away from the receiving space.

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