Battery cell shell and battery cell

Abstract

The invention relates to the technical field of batteries, in particular to a battery cell shell and a battery cell. According to the battery cell shell, a shell body comprises an annular side wall defining a containing cavity, the containing cavity is provided with an opening, and a flanging part which is folded inwards and extends in the first direction is formed at the opening of the side wall and used for connecting a sealing ring in a cap to a top cover in the cap in a pressing mode; the side wall is provided with a rolling groove part which is recessed inwards in the first direction, so that a protrusion is formed on the cavity wall of the containing cavity. The bulges and the flanging parts are arranged at intervals in the second direction; the distance between the end, facing the axis of the side wall, of the flanging part and the outer wall of the side wall in the first direction is w2, the distance between the end, facing the axis of the side wall, of the protrusion and the inner wall of the side wall in the first direction is w4, and 1.8 * w4 < = w2 < = 2.2 * w4. The assembling quality of the battery cell shell and the cap is improved, so that the use performance and the service life of the battery cell are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cell shell and a battery cell. Background Art

[0002] As lithium-ion battery technology becomes increasingly mature, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and the requirements for the performance and safety of lithium-ion batteries are increasing.

[0003] Current batteries include a shell and a cap. After the cap is assembled with the shell, part of the sealing ring in the cap of the shell will be bent inward together, so that the bent part of the shell can press the sealing ring onto the top cover of the cap to achieve battery sealing. After the shell is bent, the insufficient pressing strength of the sealing ring will affect the sealing performance of the cap, thereby affecting the performance and service life of the battery. In addition, the shell is processed by rolling to form an inner boss for positioning and supporting the cap. The structure of the inner boss affects the support strength. If the strength is insufficient, the risk of fracture and failure will increase. Summary of the Invention

[0004] In view of this, the purpose of the present application is to provide a battery cell shell and a battery cell to solve the problem that the existing battery cell shell has insufficient crimping strength on the sealing ring after bending, affecting the sealing performance, thereby reducing the performance and service life of the battery cell.

[0005] A first aspect of the present invention provides a battery cell shell, wherein the battery cell shell comprises: The housing body includes an annular side wall surrounding an accommodating cavity, the accommodating cavity having an opening, the side wall having an inwardly folded flange portion extending along a first direction formed at the opening, the side wall having an inwardly recessed groove portion along the first direction, so that a protrusion is formed on the cavity wall of the accommodating cavity; the protrusion is spaced apart from the flange portion in a second direction, and the first direction is perpendicular to the second direction; The distance between one end of the flange facing the axis of the side wall and the outer wall of the side wall in the first direction is w2; the distance between one end of the protrusion facing the axis of the side wall and the inner wall of the side wall in the first direction is w4, 1.8×w4≤w2≤2.2×w4.

[0006] Preferably, the dimension of the side wall in the first direction is w1, 0.05×w1≤w4≤0.08×w1.

[0007] Preferably, the size of the protrusion in the second direction is w3, 1.1×w3≤w4≤1.2×w3.

[0008] Preferably, the thickness of the side wall is equal at all locations, and the thickness of the side wall is g, in mm; 6×g≤w3≤7×g;11.88×g≤w2≤18.48×g;6.6×g≤w4≤8.4×g; The dimension of the side wall in the first direction is w1, 132×g≤w1≤168×g.

[0009] Preferably, in the second direction, the accommodating cavity forms a first accommodating space for accommodating the cap on a side of the protrusion facing the outside of the battery; In the second direction, the accommodating cavity forms a second accommodating space for accommodating the electrode group on the side of the protrusion facing the interior of the battery. Preferably, the thickness dimension of the flange portion in the second direction is g1, in mm; the thickness dimension of the side wall forming the first accommodating space in the first direction is g2, in mm; the thickness dimension of the groove bottom of the groove portion in the first direction is g3, in mm; the thickness dimension of the side wall forming the second accommodating space in the first direction is g4, in mm; At least two values ​​among g1, g2, g3 and g4 are not equal.

[0010] Preferably, G1=min{g1, g2, g3, g4}, 0.15mm≤G1≤0.3mm; G2=max{g1, g2, g3, g4}, 0.15mm≤G2≤0.3mm.

[0011] Preferably, 6×G1≤w3≤7×G2; 11.88×G1≤w2≤18.48×G2; 6.6×G1≤w4≤8.4×G2; The outer surface of the side wall extending in the second direction that encloses the first accommodating space and the outer surface of the side wall extending in the second direction that encloses the second accommodating space are arranged coplanar with each other; the size of the side wall in the first direction is w1, 132×G1≤w1≤168×G2.

[0012] Preferably, the housing body further includes: The bottom wall is arranged on a side of the side wall away from the opening in the second direction. A second aspect of the present invention provides a battery cell, comprising the battery cell shell described in any one of the above technical solutions.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The battery cell shell of the present invention, the shell body includes an annular side wall that forms an accommodating cavity, the accommodating cavity has an opening, and the side wall is formed with a flange portion that is folded inward and extends along a first direction at the opening, which is used to press the sealing ring in the cap onto the top cover in the cap; the side wall is provided with a rolling groove portion that is recessed inward along the first direction, so that a protrusion is formed on the cavity wall of the accommodating cavity to support the cap; the protrusion and the flange portion are spaced apart in the second direction, and the first direction is perpendicular to the second direction; the distance between one end of the axis of the flange portion facing the side wall and the outer wall of the side wall in the first direction is w2; the distance between one end of the axis of the protrusion facing the side wall and the inner wall of the side wall in the first direction is w4, 1.8×w4≤w2≤2.2×w4, thereby ensuring that the flange portion has sufficient crimping strength, ensuring the sealing of the cap, improving the assembly quality of the battery cell shell and the cap, and thus improving the performance and service life of the battery cell.

[0014] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 A schematic structural diagram of a battery cell housing provided in an embodiment of the present invention; Figure 2 A schematic structural diagram of a battery cell housing provided by an embodiment of the present invention from another perspective; Figure 3 A cross-sectional view of the structure of a battery cell housing provided by an embodiment of the present invention; Figure 4 A partially enlarged cross-sectional view of the structure of a battery cell housing of uniform wall thickness provided by an embodiment of the present invention; Figure 5 A partially enlarged structural cross-sectional view of a battery cell casing with unequal wall thicknesses provided in an embodiment of the present invention.

[0017] Icon: 1-shell body; 10-accommodation cavity; 100-opening; 101-first accommodation space; 102-second accommodation space; 1000-protrusion; 11-side wall; 111-flanged portion; 112-groove portion; 12-bottom wall; D1-first direction; D2-second direction. DETAILED DESCRIPTION

[0018] The following detailed description is provided to help the reader gain a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent upon understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein. Rather, except for operations that must occur in a particular order, changes may be made that will be apparent upon understanding the disclosure of this application. Furthermore, descriptions of features known in the art may be omitted for clarity and brevity.

[0019] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways to implement the methods, devices, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0020] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being “on,” “connected to,” “coupled to,” “over,” or “overlaying” another element, it may be directly “on,” “connected to,” “coupled to,” “over,” or “overlaying” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on,” “directly connected to,” “directly coupled to,” “directly over,” or “directly covering” another element, there may be no other elements present between them.

[0021] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0022] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are used only to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Thus, a first member, component, region, layer, or portion in the examples described herein may also be referred to as a second member, component, region, layer, or portion without departing from the teachings of the examples.

[0023] For ease of description, spatially relative terms such as "above," "upper," "below," and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element would subsequently be located "below" or "lower" relative to the other element. Thus, the term "above" encompasses both the orientations of "above" and "below," depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used herein will be interpreted accordingly.

[0024] The terms used herein are intended only to describe various examples and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular is intended to include the plural. The terms "comprise," "include," and "have" list the presence of stated features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0025] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the drawings may occur. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include changes in shapes that occur during manufacturing.

[0026] The features of the examples described herein can be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0027] According to a first aspect of the present invention, a battery cell casing is provided, which specifically includes a casing body 1 .

[0028] Hereinafter, the specific structure of the cell case according to the present embodiment as described above will be described.

[0029] In this embodiment, if Figures 1 to 3As shown, the housing body 1 includes an annular sidewall 11 that encloses a housing cavity 10. The sidewall 11 can be a cylindrical annular structure. The housing cavity 10 has an opening 100. The sidewall 11 has an inwardly folded flange portion 111 extending along a first direction D1 formed at the opening 100, which is used to press the sealing ring in the cap onto the top cover of the cap. The sidewall 11 is provided with a groove portion 112 that is recessed inward along the first direction D1, forming a protrusion 1000 on the wall of the housing cavity 10 to support the cap. The groove portion 112 can be formed by a rolling process.

[0030] Specifically, the flanging portion 111 is formed as an annular plate structure, and the groove portion 112 is formed as an annular groove structure. It should be noted that the relationship between the groove portion 112 and the protrusion 1000 can be understood as that after the side wall 11 is processed by the rolling process, the groove wall of the groove portion 112 is formed on the outer wall of the side wall 11, and the protrusion 1000 is formed on the inner wall of the side wall 11.

[0031] In this embodiment, the protrusion 1000 is spaced apart from the flange portion 111 in the second direction D2. The first direction D1 is perpendicular to the second direction D2. When the battery cell is a cylindrical battery cell, the first direction D1 is the radial direction of the battery cell, and the second direction D2 is the axial direction of the battery cell.

[0032] Preferably, the housing body 1 is a steel shell.

[0033] In this embodiment, if Figure 4 As shown, the distance between one end of the axis of the flange portion 111 facing the side wall 11 and the outer wall of the side wall 11 in the first direction D1 is w2; the distance between one end of the axis of the protrusion 1000 facing the side wall 11 and the inner wall of the side wall 11 in the first direction D1 is w4, 1.8×w4≤w2≤2.2×w4, so as to ensure that the flange portion 111 has sufficient crimping strength, ensure the sealing of the cap, improve the assembly quality of the battery cell shell and the cap, and thus enhance the performance and service life of the battery cell.

[0034] Furthermore, in this embodiment, Figure 4 As shown, the dimension of the side wall 11 in the first direction D1 is w1, 0.05×w1≤w4≤0.08×w1, which ensures that the protrusion 1000 has sufficient supporting strength to meet the assembly requirements of the cap and the battery cell shell.

[0035] In this embodiment, if Figure 4 As shown, the dimension of the protrusion 1000 in the second direction D2 is w3, 1.1×w3≤w4≤1.2×w3, so as to ensure that the protrusion 1000 has sufficient rigidity to prevent the protrusion 1000 from being easily deformed.

[0036] In an alternative embodiment, Figure 4As shown, the cell shell is formed into a shell structure with equal wall thickness, that is, the thickness of the side wall 11 is equal at all places, and the thickness dimension of the side wall 11 is g, 6×g≤w3≤7×g, which reduces the processing difficulty of the groove portion 112 and reduces the risk of fracture and failure of the protrusion 1000.

[0037] Furthermore, 11.88×g≤w2≤18.48×g, thus ensuring that the flange portion 111 has sufficient crimping strength and facilitating bending the shell body 1 to form the flange portion 111, thereby improving the sealing performance and ensuring reliable sealing. Furthermore, 6.6×g≤w4≤8.4×g, which ensures that the protrusion 1000 has sufficient supporting strength, while reducing the processing difficulty and facilitating the processing and forming of the groove portion 112. Furthermore, 132×g≤w1≤168×g, thus ensuring the structural strength of the side wall 11. It should be noted that the units of w1, w2, w3, w4 and g are all mm.

[0038] The reliability of the limiting conditions of 1.8×w4≤w2≤2.2×w4, 6×g≤w3≤7×g, 11.88×g≤w2≤18.48×g, 6.6×g≤w4≤8.4×g and 132×g≤w1≤168×g in the present invention is verified through multiple groups of tests. Each group of tests includes multiple battery cells. The test results are shown in Table 1.

[0039] Table 1

[0040] Referring to Table 1, it can be seen that in Examples 1 to 7, w1, w2, w3 and w4 are respectively within the limited ranges of 1.8×w4≤w2≤2.2×w4, 132×g≤w1≤168×g, 11.88×g≤w2≤18.48×g, 6×g≤w3≤7×g and 6.6×g≤w4≤8.4×g, the matching relationship of each dimension is reasonable, does not affect the assembly of the battery cell shell, and the sealing and safety of the assembled battery cell meet the requirements; in Comparative Example 1, due to the small size of w2, the cap cannot be effectively pressed, resulting in sealing failure; in Comparative Example 2, due to the large size of w2, the explosion-proof valve in the cap will be squeezed, affecting the opening of the explosion-proof valve, resulting in the failure of the valve opening of the three battery cells, and the safety performance of the battery cell cannot be guaranteed; in Comparative Example 3, due to the large size of w4, the sealing ring in the cap will be squeezed, resulting in cracking of the sealing ring and sealing failure.

[0041] In this embodiment, if Figures 3 to 5As shown, in the second direction D2, the accommodating cavity 10 forms a first accommodating space 101 for accommodating the cap on the side of the protrusion 1000 facing the outside of the battery; in the second direction D2, the accommodating cavity 10 forms a second accommodating space 102 for accommodating the electrode group on the side of the protrusion 1000 facing the inside of the battery. The first accommodating space 101 and the second accommodating space 102 are arranged in the second direction D2, and the pole ears on the electrode group can extend into the first accommodating space 101 and connect with the cap, thereby realizing power transmission.

[0042] In another alternative embodiment, as Figure 5 As shown, the battery cell shell is formed into a shell structure with unequal wall thickness. Specifically, the thickness dimension of the flange portion 111 in the second direction D2 is g1, in mm; the thickness dimension of the side wall 11 that encloses the first accommodating space 101 in the first direction D1 is g2, in mm; the thickness dimension of the groove bottom of the groove portion 112 in the first direction D1 is g3, in mm; the thickness dimension of the side wall 11 that encloses the second accommodating space 102 in the first direction D1 is g4, in mm; at least two values ​​of g1, g2, g3 and g4 are unequal, so that multiple positions with unequal thickness are provided on the side wall 11, thereby meeting the strength requirements of the wall thickness at different positions of the battery cell shell. Preferably, g1≠g2≠g3≠g4.

[0043] Furthermore, if Figure 5 As shown, G1=min{g1,g2,g3,g4}, that is, G1 is the minimum value among g1, g2, g3 and g4, 0.15mm≤G1≤0.3mm; G2=max{g1,g2,g3,g4}, that is, G2 is the maximum value among g1, g2, g3 and g4, 0.15mm≤G2≤0.3mm.

[0044] Furthermore, if Figure 5 As shown, 6×G1≤w3≤7×G2, which reduces the processing difficulty of the groove portion 112 and reduces the risk of fracture and failure of the protrusion 1000; 11.88×G1≤w2≤18.48×G2, which ensures that the flange portion 111 has sufficient crimping strength and facilitates bending the shell body 1 to form the flange portion 111, thereby improving the sealing performance and ensuring reliable sealing; 6.6×G1≤w4≤8.4×G2, which ensures that the protrusion 1000 has sufficient supporting strength and reduces the processing difficulty, which facilitates the processing and forming of the groove portion 112.

[0045] Preferably, 2.1×w3≤w2≤2.5×w3 and w4>w3, so that the cap is securely fixed to avoid the flange portion 111 or the groove portion 112 from being broken or collapsed.

[0046] In addition, the outer surface of the side wall 11 extending in the second direction D2 that encloses the first accommodating space 101 and the outer surface of the side wall 11 extending in the second direction D2 that encloses the second accommodating space 102 are arranged coplanar with each other, that is, the thickness difference between g2 and g4 is reflected on the inner surface of the side wall 11; the dimension of the side wall 11 in the first direction D1 is w1, 132×G1≤w1≤168×G2, thereby ensuring the structural strength of the side wall 11.

[0047] It should be noted that the units of w1, w2, w3 and w4 are all mm.

[0048] In addition, in this embodiment, Figure 2 and Figure 3 As shown, the shell body 1 also includes a bottom wall 12, which is formed into a plate-like structure perpendicular to the second direction D2. The bottom wall 12 is arranged on the side of the side wall 11 away from the opening 100 in the second direction D2 and its circumferential side wall 11 is connected to the side wall 11, so that after the battery cell is assembled, one end of the side wall 11 in the second direction D2 is closed by the bottom wall 12, and the other end is closed by the cap. According to a battery cell shell provided by the present invention, the shell body includes an annular side wall that forms an accommodating cavity, the accommodating cavity has an opening, and the side wall is formed with a flange portion that is folded inward and extends along a first direction at the opening, which is used to press the sealing ring in the cap onto the top cover in the cap; a rolling groove portion that is recessed inward along the first direction is provided on the side wall, so that a protrusion is formed on the cavity wall of the accommodating cavity to support the cap; the protrusion and the flange portion are spaced apart in the second direction, and the first direction is perpendicular to the second direction; the distance between one end of the flange portion facing the axis of the side wall and the outer wall of the side wall in the first direction is w2; the distance between one end of the protrusion facing the axis of the side wall and the inner wall of the side wall in the first direction is w4, 1.8×w4≤w2≤2.2×w4, thereby ensuring that the flange portion has sufficient crimping strength, ensuring the sealing of the cap, improving the assembly quality of the battery cell shell and the cap, and thereby improving the performance and service life of the battery cell.

[0049] A battery cell provided according to the present invention includes the battery cell shell as described above, and thus has all the above-mentioned beneficial effects, which will not be described in detail here.

[0050] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed in the present application, or perform equivalent replacements for some of the technical features thereof. These modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims.

Claims

1. A battery cell shell, characterized in that: The battery cell housing comprises: The housing body includes an annular side wall surrounding an accommodating cavity, the accommodating cavity having an opening, the side wall having an inwardly folded flange portion extending along a first direction formed at the opening, the side wall having an inwardly recessed groove portion along the first direction, so that a protrusion is formed on the cavity wall of the accommodating cavity; the protrusion is spaced apart from the flange portion in a second direction, and the first direction is perpendicular to the second direction; The distance between one end of the flange facing the axis of the side wall and the outer wall of the side wall in the first direction is w2; the distance between one end of the protrusion facing the axis of the side wall and the inner wall of the side wall in the first direction is w4, 1.8×w4≤w2≤2.2×w4.

2. The battery cell housing according to claim 1, wherein: The dimension of the side wall in the first direction is w1, 0.05×w1≤w4≤0.08×w1.

3. The battery cell housing according to claim 1, wherein: The size of the protrusion in the second direction is w3, 1.1×w3≤w4≤1.2×w3.

4. The battery cell housing according to claim 3, wherein: The thickness of the side wall is equal at all locations, and the thickness of the side wall is g, in mm; 6×g≤w3≤7×g; 11.88×g≤w2≤18.48×g; 6.6×g≤w4≤8.4×g; The dimension of the side wall in the first direction is w1, 132×g≤w1≤168×g.

5. The battery cell casing according to claim 3, characterized in that: In the second direction, the accommodating cavity forms a first accommodating space for accommodating the cap on a side of the protrusion facing the outside of the battery; In the second direction, the accommodating cavity forms a second accommodating space for accommodating the electrode group on the side of the protrusion facing the interior of the battery.

6. The battery cell casing according to claim 5, characterized in that: The thickness dimension of the flange portion in the second direction is g1, in mm; the thickness dimension of the side wall forming the first receiving space in the first direction is g2, in mm; the thickness dimension of the groove bottom of the groove portion in the first direction is g3, in mm; the thickness dimension of the side wall forming the second receiving space in the first direction is g4, in mm; At least two values ​​among g1, g2, g3 and g4 are not equal.

7. The battery cell casing according to claim 6, characterized in that: G1=min{g1,g2,g3,g4}, 0.15mm≤G1≤0.3mm; G2=max{g1,g2,g3,g4}, 0.15mm≤G2≤0.3mm.

8. The battery cell casing according to claim 7, characterized in that: 6×G1≤w3≤7×G2;11.88×G1≤w2≤18.48×G2; 6.6×G1≤w4≤8.4×G2; The outer surface of the side wall extending in the second direction that encloses the first accommodating space and the outer surface of the side wall extending in the second direction that encloses the second accommodating space are arranged coplanar with each other; the size of the side wall in the first direction is w1, 132×G1≤w1≤168×G2.

9. The battery cell casing according to claim 1, wherein: The housing body further comprises: The bottom wall is arranged on a side of the side wall away from the opening in the second direction.

10. A battery cell, characterized in that: A battery cell casing comprising the battery cell casing according to any one of claims 1 to 9.

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