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. The battery cell shell comprises a shell and a cover plate, the cover plate comprises a plate body part and a connecting part surrounding the circumferential side wall of the plate body part, and the plate body part is assembled in the accommodating cavity; the connecting part comprises a first connecting part abutting against the cavity wall of the containing cavity and a second connecting part spaced from the cavity wall of the containing cavity, the connecting part is bent, one end of the connecting part is connected with the plate body part, and the other end of the connecting part forms a sealing part connected with the end of the shell. The connecting part on the cover plate is bent twice, deformation generated in the stress release process of the cover plate is counteracted, one end of the connecting part is connected with the plate body part, the other end of the connecting part forms the sealing part connected with the end of the shell, and it is guaranteed that the cover plate and the shell are assembled reliably; and the assembly yield of the cover plate and the shell and the welding quality and safety of the cover plate and the shell are improved, so that the production yield of the battery cell is improved, and the production cost of the battery cell is reduced.

Description

Technical Field

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

[0002] As lithium-ion battery technology matures, 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. The shell is an important component of lithium batteries, which is used to carry the battery cell pole group and can be assembled and welded with the cover to form a sealed battery cell space. At present, the cover of the steel shell battery adopts L-shaped bending and is welded and assembled with the shell. After the cover of the steel shell battery is bent and formed, the bending position expands outward due to the release of material stress, and the size of the stamping step assembled with the shell is difficult to control, resulting in poor assembly of the shell cover, resulting in low production yield and production efficiency, and high cost of the battery. Summary of the invention

[0003] In view of this, the purpose of the present application is to provide a battery cell casing and a battery cell to solve the problem that the cover of the existing steel shell battery cell is prone to expand outward at the bending position after being bent into an L shape, resulting in poor assembly of the shell cover, thereby leading to low production yield and low production efficiency of the battery cell.

[0004] A first aspect of the present invention provides a battery cell casing, the battery cell casing comprising: A housing having an opening formed therein; The cover plate includes a plate body and a connecting portion surrounding the circumferential side wall of the plate body, wherein the plate body is assembled in the accommodating cavity; the connecting portion includes a first connecting portion abutting against the cavity wall of the accommodating cavity and a second connecting portion spaced apart from the cavity wall of the accommodating cavity, so that the connecting portion is bent, and one end of the connecting portion is connected to the plate body, and the other end of the connecting portion is formed as a sealing portion connected to the end of the shell.

[0005] Preferably, the thickness dimension of the cover plate is T1, 0.2 mm ≤ T1 ≤ 0.4 mm, and / or the wall thickness dimension of the shell is T2, 0.1 mm ≤ T2 ≤ 0.3 mm.

[0006] Preferably, the connecting portion further comprises a first fillet provided between the sealing portion and the second connecting portion, the radius of the first fillet is R1, and 0.5 mm ≤ R1 ≤ 1.2 mm.

[0007] Preferably, the connecting portion further comprises a second fillet provided between the plate body and the first connecting portion, the radius of the second fillet is R2, and 0.5 mm ≤ R2 ≤ 1.2 mm.

[0008] Preferably, the distance between the second connecting portion and the cavity wall of the accommodating cavity is N, and 0.3 mm≤N≤5 mm. Preferably, the connection portion further includes a third connection portion provided between the first connection portion and the second connection portion.

[0009] Preferably, the length dimension of the third connecting portion is L, and the connecting portion also includes a third fillet arranged between the second connecting portion and the third connecting portion and a fourth fillet arranged between the first connecting portion and the third connecting portion, the radius of the third fillet is R3, the angle of the central angle of the third fillet is X, X≤90°, the radius of the fourth fillet is R4, N=(R3-T1+R4)×(1-cosX)+L×sinX.

[0010] Preferably, a dimension of the connecting portion in a depth direction of the accommodating cavity is H, 2.2 mm ≤ H ≤ 6 mm.

[0011] Preferably, the end of the sealing portion away from the second connecting portion is coplanar with the outer wall of the shell; And / or, the battery cell casing is made of steel.

[0012] A second aspect of the present invention provides a battery cell, comprising the battery cell casing 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 casing of the present invention comprises a cover plate including a plate body portion and a connecting portion arranged on a circumferential side wall of the plate body portion, wherein the plate body portion is assembled in a receiving cavity of a shell; the connecting portion comprises a first connecting portion abutting against a cavity wall of the receiving cavity and a second connecting portion spaced apart from the cavity wall of the receiving cavity, so that the connecting portion is bent twice, thereby offsetting the deformation generated during the stress release process of the cover plate; one end of the connecting portion is connected to the plate body portion, and the other end is formed as a sealing portion connected to an end portion of the shell, thereby ensuring reliable assembly of the cover plate and the shell, improving the assembly yield of the cover plate and the shell, and the welding quality and safety of the cover plate and the shell, thereby improving the production yield of the battery cell and reducing the production cost 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 specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0016] Figure 1 A schematic diagram of the structure of a battery cell casing provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a battery cell housing provided by an embodiment of the present invention from another perspective; Figure 3 For along Figure 2 The cross-section taken at AA in the middle; Figure 4 for Figure 3 Enlarged structural diagram at B in the middle.

[0017] Icon: 10-shell; 11-accommodating cavity; 20-cover plate; 21-plate body; 22-connecting part; 221-first connecting part; 222-second connecting part; 223-third connecting part; 224-sealing part; 225-first rounded corner; 226-second rounded corner; 227-third rounded corner; 228-fourth rounded corner; 30-pole. DETAILED DESCRIPTION

[0018] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, in order to improve clarity and brevity, descriptions of features known in the art may be omitted.

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

[0020] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, “bound to”, “over”, or “covering” another element, it may be directly “on”, “connected to”, “bound to”, “over”, or “covering” 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 bound 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 only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, component, region, layer, or portion referred to may also be referred to as the second member, component, region, layer, or portion.

[0023] For ease of description, spatial relational 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 spatial relational terms are intended to include 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 will subsequently be "below" or "lower" relative to the other element. Therefore, the term "above" includes both "above" and "below" orientations 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 spatial relational terms used herein will be interpreted accordingly.

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

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

[0026] The features of the examples described herein may 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 includes a casing 10 and a cover plate 20 .

[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 3 As shown, a receiving cavity 11 with an opening is formed inside the shell 10 for accommodating components such as the pole group arranged inside the battery cell. The cover plate 20 is assembled on the opening to close the receiving cavity 11. The cover plate 20 is welded to the shell 10. A protruding pole 30 is provided on the cover plate 20. The pole 30 is connected to the pole ear on the pole group to realize the transmission of electric energy.

[0030] In this embodiment, if Figure 2 and Figure 3 As shown, the cover plate 20 includes a plate body portion 21 and a connecting portion 22 arranged around the circumferential side wall of the plate body portion 21, the plate body portion 21 is formed as a plate-like structure, the plate body portion 21 is assembled in the accommodating cavity 11, so that the plate body is embedded in the shell 10 at a preset depth, the connecting portion 22 is arranged on the side of the plate body portion 21 facing the outside of the battery cell and is formed as an annular structure that can abut against the cavity wall of the accommodating cavity 11, so that a groove is formed at one end of the cover plate 20 facing the outside of the battery cell, the plate body portion 21 is the groove bottom of the groove, and the connecting portion 22 is the groove wall of the groove.

[0031] Specifically, Figure 3 and Figure 4As shown, the connecting portion 22 includes a first connecting portion 221 abutting against the cavity wall of the accommodating cavity 11 and a second connecting portion 222 spaced apart from the cavity wall of the accommodating cavity 11, so that the connecting portion 22 is bent twice, thereby offsetting the deformation generated during the stress release process of the cover plate 20. One end of the connecting portion 22 is connected to the plate body 21, and the other end of the connecting portion 22 is formed as a sealing portion 224 connected to the end of the shell 10, eliminating the stamping step on the traditional steel shell cover plate 20, ensuring reliable assembly of the cover plate 20 and the shell 10, improving the assembly yield of the cover plate 20 and the shell 10, and the welding quality and safety of the cover plate 20 and the shell 10, thereby improving the production yield of the battery cell and reducing the production cost of the battery cell.

[0032] Preferably, if Figure 3 and Figure 4 As shown, the end of the sealing portion 224 away from the second connecting portion 222 is coplanar with the outer wall of the housing 10, thereby ensuring that the cover plate 20 and the housing 10 are effectively overlapped and facilitating welding of the cover plate 20 and the housing 10. In this embodiment, the sealing portion 224 is formed as an annular plate structure arranged parallel to the plate body 21.

[0033] In this embodiment, the cover plate 20 is made of steel, such as stainless steel, specifically 304 stainless steel, and the cover plate 20 is formed by stamping and bending a mold. Preferably, the housing 10 is also made of steel.

[0034] In a preferred embodiment, Figure 4 As shown, the thickness dimension of the cover plate 20 is T1, 0.2mm≤T1≤0.4mm, which facilitates the molding of the cover plate 20 and ensures that the molded cover plate 20 has sufficient structural strength, meets welding requirements and avoids excessive size and occupying the battery cell space. In this embodiment, the wall thickness dimension of the shell 10 is T2, 0.1mm≤T2≤0.3mm, which ensures that the shell 10 can protect the components inside the battery cell and meet the welding connection requirements of the shell 10 and the cover plate 20.

[0035] In this embodiment, if Figure 3 and Figure 4 As shown, the connecting portion 22 also includes a first fillet 225 arranged between the sealing portion 224 and the second connecting portion 222 to achieve a smooth transition between the sealing portion 224 and the second connecting portion 222 to avoid stress concentration. The radius of the first fillet 225 is R1, 0.5mm≤R1≤1.2mm, which helps to release stress and facilitates processing.

[0036] Furthermore, in this embodiment, if Figure 3 and Figure 4As shown, the connecting portion 22 also includes a second fillet 226 disposed between the plate body 21 and the first connecting portion 221 to achieve a smooth transition between the plate body 21 and the second connecting portion 222. The radius of the second fillet 226 is R2, 0.5mm≤R2≤1.2mm, which helps release stress and facilitates processing.

[0037] In this embodiment, if Figure 3 and Figure 4 As shown, the distance between the second connecting portion 222 and the cavity wall of the accommodating cavity 11 is N, 0.3mm≤N≤5mm, so as to ensure that the sealing portion 224 and one end of the shell 10 in the depth direction of the accommodating cavity 11 are effectively overlapped to meet the assembly requirements of the patch on the cover plate 20 to form effective protection, and to ensure that the connecting portion 22 has sufficient structural strength so that it is not easily deformed during the assembly process with the shell 10.

[0038] It should be noted that Figure 3 The vertical direction under the viewing angle is the depth direction of the accommodating cavity 11 .

[0039] In this embodiment, if Figure 4 As shown, the connection part 22 also includes a third connection part 223 arranged between the first connection part 221 and the second connection part 222, so that the first connection part 221 and the second connection part 222 are spaced apart in the depth direction of the accommodating cavity 11, ensuring that the connection part 22 after the secondary bending can effectively offset the deformation during the stress release process.

[0040] Furthermore, in this embodiment, if Figure 4 As shown, the length dimension of the third connection part 223 is L, and the connection part 22 also includes a third fillet 227 arranged between the second connection part 222 and the third connection part 223 and a fourth fillet 228 arranged between the first connection part 221 and the third connection part 223, so as to achieve a smooth transition between the second connection part 222 and the third connection part 223 and between the first connection part 221 and the third connection part 223, which is convenient for bending and forming and avoids stress concentration. The radius of the third fillet 227 is R3, and the angle of the central angle of the third fillet 227 is X, X≤90°. The radius of the fourth fillet 228 is R4. In this embodiment, the distance N between the second connection part 222 and the cavity wall of the accommodating cavity 11 is calculated as follows: N=(R3-T1+R4)×(1-cosX)+L×sinX.

[0041] In this embodiment, if Figure 4 As shown, the dimension of the connection portion 22 in the depth direction of the accommodating cavity 11 is H, 2.2mm≤H≤6mm, so that the connection portion 22 is easy to bend and avoids the connection portion 22 being too large to occupy the space of the accommodating cavity 11 and reduce the capacity of the battery cell. Figure 4As shown, the dimension H of the connecting portion 22 in the depth direction of the accommodating cavity 11 is calculated as: H=R1+R2+Y1+Y2+L×cosX+(R3-T1+R4)×sinX, wherein Y1 is the dimension of the second connecting portion 222 in the depth direction of the accommodating cavity 11, and Y2 is the dimension of the first connecting portion 221 in the depth direction of the accommodating cavity 11.

[0042] Next, the cover plates 20 with different sizes are assembled with the housing 10 with the same size to test the assembly quality of the housing 10 and the cover plate 20. The test results are shown in Table 1 below.

[0043] Table 1

[0044] Note: In the table, an “OK” test result indicates that the assembly of the cover plate 20 and the housing 10 is qualified, and an “NG” test result indicates that the assembly of the cover plate 20 and the housing 10 is unqualified.

[0045] All parameters in Example 1, Example 2, Example 6, and Example 8 to Example 11 are within the specified range, and the cover plate 20 and the shell 10 are qualified for assembly. However, in Example 3, the space occupied by the cover plate 20 in the accommodating cavity 11 is too large, which is not conducive to the design of the battery cell capacity, and the cover plate 20 has poor bending strength and is easy to deform, affecting its assembly with the shell 10. In Example 4, the distance between the second connecting portion 222 and the cavity wall of the accommodating cavity 11 is too large, which affects the assembly protection of the patch and the cover plate 20, and the service life of the mold used to stamp the cover plate 20 is low and the development cost is high. In Example 5, the cover plate 20 has poor bending strength, is easy to deform, and the welding yield of the cover plate 20 and the shell 10 is low. In Example 7, the cover plate 20 has poor bending strength, is easy to deform, and the mold is easy to wear and has a low life.

[0046] A battery cell casing provided according to the present invention includes a cover plate and a shell, the cover plate includes a plate body portion and a connecting portion surrounded by a circumferential side wall of the plate body portion, the plate body portion is assembled in a receiving cavity of the shell; the connecting portion includes a first connecting portion abutting against the cavity wall of the receiving cavity and a second connecting portion spaced apart from the cavity wall of the receiving cavity, so that the connecting portion is bent twice to present an S-shaped cross-section, offsetting the deformation generated during the stress release process of the cover plate, one end of the connecting portion is connected to the plate body portion, and the other end is formed as a sealing portion connected to the end of the shell, thereby ensuring reliable assembly of the cover plate and the shell, improving the assembly yield of the cover plate and the shell, and improving the welding quality and safety of the cover plate and the shell.

[0047] A battery cell provided according to the present invention includes the battery cell casing as described above, and the cover plate and the shell are assembled reliably, thereby improving the assembly yield of the cover plate and the shell, thereby improving the production yield of the battery cell and reducing the production cost of the battery cell.

[0048] 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 protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A battery cell casing, characterized in that: The battery cell housing comprises: A housing having an opening formed therein; The cover plate includes a plate body and a connecting portion surrounding the circumferential side wall of the plate body, wherein the plate body is assembled in the accommodating cavity; the connecting portion includes a first connecting portion abutting against the cavity wall of the accommodating cavity and a second connecting portion spaced apart from the cavity wall of the accommodating cavity, so that the connecting portion is bent, and one end of the connecting portion is connected to the plate body, and the other end of the connecting portion is formed as a sealing portion connected to the end of the shell.

2. The battery cell casing according to claim 1, characterized in that: The thickness dimension of the cover plate is T1, 0.2mm≤T1≤0.4mm, and / or the wall thickness dimension of the shell is T2, 0.1mm≤T2≤0.3mm.

3. The battery cell casing according to claim 1, characterized in that: The connecting portion further includes a first fillet provided between the sealing portion and the second connecting portion, the radius of the first fillet is R1, and 0.5 mm ≤ R1 ≤ 1.2 mm.

4. The battery cell casing according to claim 1, characterized in that: The connecting portion further includes a second fillet provided between the plate body and the first connecting portion, the radius of the second fillet is R2, and 0.5 mm ≤ R2 ≤ 1.2 mm.

5. The battery cell casing according to claim 2, characterized in that: The distance between the second connecting portion and the cavity wall of the accommodating cavity is N, 0.3 mm≤N≤5 mm.

6. The battery cell casing according to claim 5, characterized in that: The connection portion further includes a third connection portion disposed between the first connection portion and the second connection portion.

7. The battery cell casing according to claim 6, characterized in that: The length dimension of the third connecting portion is L, and the connecting portion also includes a third fillet arranged between the second connecting portion and the third connecting portion and a fourth fillet arranged between the first connecting portion and the third connecting portion, the radius of the third fillet is R3, the angle of the central angle of the third fillet is X, X≤90°, the radius of the fourth fillet is R4, N=(R3-T1+R4)×(1-cosX)+L×sinX.

8. The battery cell casing according to claim 1, characterized in that: The dimension of the connecting portion in the depth direction of the accommodating cavity is H, 2.2 mm≤H≤6 mm.

9. The battery cell casing according to claim 1, characterized in that: The end of the sealing portion away from the second connecting portion is coplanar with the outer wall of the shell; And / or, the cover plate is made of steel.

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

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