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 welding part is formed on a first side wall of a shell main body, and the welding part comprises a first bulge protruding towards the outer part of the shell main body and a second bulge protruding towards the inner part of the shell main body; the length of the first protrusion in the direction perpendicular to the first side wall is a, and a is larger than 0 and smaller than or equal to 0.05 mm. The length of the second protrusion in the direction perpendicular to the first side wall is b, and b is larger than 0 and smaller than or equal to 0.15 mm. The wall thickness of the shell body is h, the width size of the shell body in the first direction is W, the unit is mm, and h / W is larger than or equal to 0.015 and smaller than or equal to 0.055. According to the invention, the structural strength of the welding part on the shell main body can be ensured, and the problem of cracking at the position of the welding part when the shell main body is impacted or pressed is avoided, so that the pressure resistance of the position, provided with the welding part, on the shell main body is improved, and the safety performance and the service life of the battery cell are further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and more particularly to a battery cell housing and a battery cell. Background Art

[0002] Lithium-ion batteries have the advantages of large capacity, small size, light weight, and environmental friendliness, and have been widely used in industries such as digital electronic products and electric vehicles.

[0003] The battery consists of a top cover and a housing to form a sealed space for the entire system. The top cover and the housing are integrally formed by laser welding. The common housing forming method is a drawn housing, and there are also some housing structures formed by welding. Among them, for the housing structure formed by welding, there are welds formed by metal fusion. The structural strength at the weld is relatively weak compared to other positions on the housing. When the battery is under complex operating conditions, it will be subjected to vibration and impact. The pressure resistance of the weld is insufficient and it is prone to fracture, resulting in the housing being easily cracked, affecting the safety performance and service life of the battery cell. In addition, during the formation of the weld, it is easy to affect the shape accuracy of the housing, thereby affecting the assembly yield with the cover plate in subsequent assembly. Summary of the Invention

[0004] In view of this, the purpose of the present application is to provide a battery cell housing and a battery cell to solve the problem that the structural strength at the weld on the existing battery cell housing is relatively weak, so that the battery cell is prone to fracture at the weld under external force, resulting in the battery cell housing being easily cracked, and further affecting the safety performance and service life of the battery cell.

[0005] The first aspect of the present invention provides a battery cell housing, wherein the battery cell housing includes:

[0006] A housing main body having a first side wall, and a welding portion is formed on the first side wall. The welding portion includes a first protrusion protruding towards the outside of the housing main body and a second protrusion protruding towards the inside of the housing main body; the length dimension of the first protrusion in the direction perpendicular to the first side wall is a, 0 < a ≤ 0.05 mm; the length dimension of the second protrusion in the direction perpendicular to the first side wall is b, 0 < b ≤ 0.15 mm;

[0007] The wall thickness of the housing main body is h, in mm; the width dimension of the housing main body in the first direction is W, in mm, 0.015 ≤ h / W ≤ 0.055.

[0008] Preferably, 0.15 mm ≤ h ≤ 1.0 mm.

[0009] Preferably, the housing body is formed into a rectangular housing structure. The housing body includes two first side walls arranged opposite to each other and two second side walls arranged opposite to each other. The first side walls and the second side walls are alternately arranged to enclose the housing body; the area of the first side walls is smaller than the area of the second side walls.

[0010] Preferably, the welding part is formed into a strip structure. The height dimension of the housing body in the second direction is H, with the unit of mm, and 1 < H / W ≤ 12. The second direction is perpendicular to the first direction and the length direction of the welding part respectively.

[0011] Preferably, the pressure resistance strength P of the welding part ≥ 1.2 Mpa;

[0012] And / or, the flatness of the outer surface of the second side wall is S, and 0 < S ≤ 0.5 mm.

[0013] Preferably, the welding part is formed by high-frequency welding.

[0014] Preferably, a < b.

[0015] Preferably, an accommodation cavity is formed inside the housing body, and the accommodation cavity has at least one opening;

[0016] When the accommodation cavity has one opening, the opening is arranged at one end in the length direction of the welding part;

[0017] When the accommodation cavity has multiple openings, at least two openings are arranged opposite to each other in the length direction of the welding part.

[0018] Preferably, the housing body is made of aluminum material; or the housing body is made of steel material.

[0019] The second aspect of the present invention provides an electric core, including the electric core housing according to any one of the above technical solutions.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] The battery cell housing of the present invention has a receiving cavity formed inside the housing body. A welding portion is formed on the first side wall of the housing body. The welding portion includes a first protrusion protruding towards the outside of the housing body and a second protrusion protruding towards the inside of the housing body. The length dimension of the first protrusion in the direction perpendicular to the first side wall is a, where 0 < a ≤ 0.05 mm, and the length dimension of the second protrusion in the direction perpendicular to the first side wall is b, where 0 < b ≤ 0.15 mm. This ensures the structural strength of the welding portion and prevents the housing body from cracking at the position of the welding portion when subjected to impact or pressure. The wall thickness of the housing body is h in mm, and the width dimension of the housing body in the first direction is W in mm, where 0.015 ≤ h / W ≤ 0.055. This improves the welding quality of the welding portion, thereby enhancing the pressure resistance and sealing performance of the position on the housing body where the welding portion is provided, preventing the housing body from cracking during use, and further enhancing the safety performance and service life of the battery cell.

[0022] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, provides a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a schematic structural diagram of the battery cell housing provided by an embodiment of the present invention;

[0025] Figure 2 It is a schematic structural diagram of the battery cell housing provided by an embodiment of the present invention from another perspective;

[0026] Figure 3 It is a schematic structural diagram of the welding portion in the battery cell housing provided by an embodiment of the present invention.

[0027] Reference numerals: 10 - housing body; 100 - receiving cavity; 1000 - opening; 11 - welding portion; 111 - first protrusion; 112 - second protrusion; 101 - first side wall; 102 - second side wall; D1 - first direction; D2 - second direction. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following specific embodiments are provided to assist the reader in obtaining a comprehensive understanding of the methods, apparatuses, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, and / or systems described herein will be apparent after 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, but rather changes that will be apparent after understanding the disclosure of this application may be made, except for operations that must occur in a specific order. Additionally, descriptions of features known in the art may be omitted for increased clarity and conciseness.

[0029] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many possible ways of implementing the methods, apparatuses, and / or systems described herein that will be apparent after understanding the disclosure of this application.

[0030] Throughout the specification, when an element (such as, a layer, region, or substrate) is described as "on" another element, "connected to" another element, "coupled to" another element, "above" another element, or "covering" another element, it may be directly "on", "connected to", "coupled to", "above", or "covering" the other element, or there may be one or more other elements intervening therebetween. In contrast, when an element is described as "directly on", "directly connected to", "directly coupled to", "directly above", or "directly covering" another element, there may be no other elements intervening therebetween.

[0031] As used herein, the term "and / or" includes any one of the listed related items and any combination of any two or more of them.

[0032] Although terms such as "first", "second", and "third" may be used herein to describe various components, elements, regions, layers, or parts, these components, elements, regions, layers, or parts are not limited by these terms. Rather, these terms are only used to distinguish one component, element, region, layer, or part from another. Thus, the first component, element, region, layer, or part described in the examples herein may also be referred to as the second component, element, region, layer, or part without departing from the teachings of the examples.

[0033] For ease of description, spatial relationship terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another as shown in the accompanying drawings. Such spatial relationship 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 flipped, an element described as "above" or "upper" relative to another element will then be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientation 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 spatial relationship terms used herein will be interpreted accordingly.

[0034] The terms used herein are for the purpose of describing various examples only and are not intended to limit the disclosure. Unless the context clearly dictates otherwise, the singular forms are also intended to include the plural forms. The terms "comprises", "comprising", and "having" list the stated features, quantities, operations, components, elements, and / or combinations thereof that exist, but do not preclude the existence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0035] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the accompanying drawings may occur. Thus, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that occur during manufacturing.

[0036] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of this application. In addition, although the examples described herein have various configurations, other configurations are possible, as will be apparent after understanding the disclosure of this application.

[0037] According to a first aspect of the present invention, a battery cell housing is provided, which specifically includes a housing body 10.

[0038] Hereinafter, the specific structure of the battery cell housing according to the present embodiment as described above will be described.

[0039] In the present embodiment, as Figure 1 and Figure 2 shown, the housing body 10 is a housing structure formed by bending a plate-like structure, and an accommodation cavity 100 is formed inside the enclosed space. A welding portion 11 is formed on the first side wall 101 of the housing body 10, that is, after the plate-like structure is bent, the butt joint position is connected by a welding process. The welding portion 11 can be understood as a weld formed by the welding process.

[0040] Specifically, as Figure 3As shown, the welding part 11 includes a first protrusion 111 protruding towards the outside of the housing body 10 and a second protrusion 112 protruding towards the inside of the housing body 10. That is, the protruding directions of the first protrusion 111 and the second protrusion 112 are opposite. The cross-section of the first protrusion 111 or the second protrusion 112 can be in the shape of a rectangle, a trapezoid, a semi-circle, etc. The cross-section shape of the second protrusion 112 can be the same as or different from the cross-section shape of the first protrusion 111. It should be noted that the cross-section of the first protrusion 111 or the second protrusion 112 is a section perpendicular to the extending direction of the welding part 11.

[0041] Furthermore, in this embodiment, as Figure 1 shown, the welding part 11 is formed into a strip structure. Preferably, the welding part 11 extends along the length direction of the housing body 10, which is convenient for welding. As Figure 3 shown, the length dimension of the first protrusion 111 in the direction perpendicular to the first side wall 101 is a, where 0 < a ≤ 0.05 mm; the length dimension of the second protrusion 112 in the direction perpendicular to the first side wall 101 is b, where 0 < b ≤ 0.15 mm. In this way, the structural strength of the welding part 11 is ensured, and the situation that the housing body 10 cracks at the position of the welding part 11 when being impacted or pressured is avoided.

[0042] Preferably, a < b. In this way, while ensuring the structural strength of the welding part 11, the flatness of the outer surface of the first side wall 101 can be improved.

[0043] Preferably, the protruding directions of the first protrusion 111 and the second protrusion 112 are the wall thickness directions of the first side wall 101.

[0044] Even further, in this embodiment, as Figure 2 shown, the wall thickness of the housing body 10 is h, with the unit of mm; the width dimension of the housing body 10 in the first direction D1 is W, with the unit of mm, and 0.015 ≤ h / W ≤ 0.055. In this way, the quality of the welding part 11 is improved, thereby improving the pressure resistance of the position on the housing body 10 where the welding part 11 is provided, avoiding the situation that the housing body 10 cracks during use, and further improving the sealing performance and safety performance of the battery cell.

[0045] In a preferred embodiment, the housing body 10 is a housing with an equal wall thickness, that is, the wall thickness at the positions on the housing body 10 other than the welding part 11 is equal, and 0.15 mm ≤ h ≤ 1.0 mm, thereby further improving the effectiveness and reliability of the limitation condition of 0.015 ≤ h / W ≤ 0.055.

[0046] In this embodiment, the pressure resistance strength P of the welding part 11 is P ≥ 1.2 Mpa, that is, when the welding part 11 bears a pressure less than 1.2 Mpa, it will not crack, so as to ensure that the battery cell housing has sufficient structural strength and pressure resistance performance to meet the usage conditions of the battery cell.

[0047] Furthermore, in this embodiment, as Figure 1 and Figure 2 shown, the housing body 10 is formed into a rectangular housing structure. Specifically, the housing body 10 includes two first side walls 101 arranged opposite to each other and two second side walls 102 arranged opposite to each other. The first side walls 101 and the second side walls 102 are alternately arranged to enclose the housing body 10; preferably, one of the two first side walls 101 is provided with the welding part 11, so as to simplify the preparation process of the battery cell housing and also reduce the risk of cracking of the welding part 11.

[0048] Furthermore, the first side walls 101 and the second side walls 102 are perpendicular to each other. Preferably, a fillet is provided between the first side walls 101 and the second side walls 102 to reduce the risk of stress concentration and also reduce the situation of scratching and damage of the insulating film to a certain extent, so as to ensure the insulation performance of the battery cell.

[0049] Preferably, the area of the first side wall 101 is smaller than the area of the second side wall 102, so that the welding part 11 is formed on the side wall with a relatively smaller area. In this way, when multiple battery cells are assembled into a battery module, they can be arranged and assembled by fitting each other through the second side walls 102, reducing the occupied space of the battery module in the battery pack, thereby improving the endurance of the battery pack.

[0050] Furthermore, in this embodiment, the flatness of the outer surface of the second side wall 102 is S, where 0 < S ≤ 0.5 mm, so as to avoid the situation that the two second side walls 102 are relatively recessed inward, causing the opening 1000 of the accommodating cavity 100 to deform accordingly, resulting in difficult assembly or even assembly failure of the battery cell housing and the cover plate.

[0051] In this embodiment, as Figure 1 and Figure 2 shown, the accommodating cavity 100 has at least one opening 1000, so that when assembling the battery cell, components such as the electrode group assembled inside the battery cell housing can extend into the accommodating cavity 100. Specifically, when the accommodating cavity 100 has one opening 1000, the opening 1000 is provided at one end in the length direction of the welding part 11; when the accommodating cavity 100 has multiple openings 1000, at least two openings 1000 are arranged opposite to each other in the length direction of the welding part 11.

[0052] In this embodiment, as Figure 2As shown, the height dimension of the housing body 10 in the second direction D2 is H, with the unit of mm, and 1 < H / W ≤ 12. In this way, it is avoided that the difference between H and W is too large, which causes the second side wall 102 to be recessed towards the inside of the battery cell, affecting the flatness S as described above, resulting in a poor flatness at the opening 1000 of the accommodation cavity 100 of the housing body 10 after welding, thus affecting the assembly yield rate of the battery cell housing and the cover plate. In this embodiment, the dimension of the housing body 10 in the second direction D2 is greater than the dimension of the housing body 10 in the first direction D1, and the second direction D2 is perpendicular to the first direction D1 and the length direction of the welding part 11 respectively.

[0053] It should be noted that the first direction D1 is perpendicular to the length direction of the welding part 11, and 1 < H / W means that the height dimension H of the housing body 10 in the second direction D2 is greater than the width dimension W of the housing body 10 in the first direction D1.

[0054] Next, the pressure resistance P and sealing performance of the welding part 11 and the flatness S of the outer surface of the second side wall 102 of the battery cell housing with different dimensions of h, W, and H are detected. It should be noted that the helium leak rate result less than or equal to 1×10 - 7 Pa·m 3 / s means that the sealing performance test is qualified, so as to verify the reliability of the above-mentioned limited ranges of h / W and H / W. The test results are shown in Table 1 and Table 2.

[0055] Table 1

[0056]

[0057]

[0058] Table 2

[0059] h / mm W / mm h / W H / mm H / W P / Mpa <![CDATA[Helium leak detection rate / Pa·m 3 / s]]> S / mm Comparative Example 1 0.15 10.2 0.0147 106 10.39 1.03 <![CDATA[4.1×10 -7 > 0.47 Comparative Example 2 0.15 10.8 0.0139 125 11.57 0.96 <![CDATA[2.4×10 -6 > 0.36 Comparative Example 3 0.45 30.2 0.0149 180 5.96 1.16 <![CDATA[3.1×10 -7 > 0.23 Comparative Example 4 0.45 32.5 0.0138 215 6.62 0.94 <![CDATA[6.7×10 -6 > 0.13 Comparative Example 5 0.75 24.6 0.0305 302 12.28 1.46 <![CDATA[2.3×10 -9 > 0.63 Comparative Example 6 0.75 35.8 0.0209 438 12.23 1.35 <![CDATA[4.6×10 -9 > 0.77 Comparative Example 7 1.0 22.5 0.0444 290 12.89 1.32 <![CDATA[7.5×10 -8 > 0.52 Comparative Example 8 1.0 31.6 0.0316 385 12.18 1.21 <![CDATA[5.6×10 -9 > 0.82 Comparative Example 9 0.15 2.7 0.0555 32.3 11.96 0.82 <![CDATA[3.6×10 -6 > 0.32 Comparative Example 10 0.45 8.0 0.0563 80.4 10.05 1.03 <![CDATA[6.8×10 -7 > 0.09 Comparative Example 11 0.75 12.9 0.0581 135.4 10.50 0.93 <![CDATA[7.0×10 -6 > 0.44 Comparative Example 12 1.0 16.3 0.0613 184.1 11.29 1.03 <![CDATA[8.5×10 -7 > 0.11

[0060] Referring to Table 1 above, it can be seen that in Embodiments 1 to 12, h / W is within the range of 0.015 to 0.055, and the pressure resistance P and sealing performance meet the usage requirements of the battery cell housing. In addition, H / W is within the range of greater than 1 and less than or equal to 12, and the flatness S of the outer surface of the second side wall 102 is within the range of greater than 0 and less than or equal to 0.5 mm, ensuring that the battery cell housing has good shape accuracy and meets the assembly requirements with the cover plate.

[0061] Referring to the above Table 2, it can be seen that in Comparative Examples 1 to 4, h / W is less than 0.015, resulting in the pressure resistance P and the sealing performance not meeting the usage requirements of the battery cell housing, and the usage performance and safety performance of the battery cell cannot be guaranteed; in Comparative Examples 5 to 8, H / W is greater than 12, and the excessive gap between H and W causes the second side wall 102 to be recessed towards the inside of the battery cell, thereby affecting the shape accuracy of the opening 1000, resulting in difficulty in assembling the battery cell housing and the cover plate, and not meeting the assembly requirements of the battery cell housing and the cover plate; in Comparative Examples 9 to 12, h / W is greater than 0.055, resulting in the pressure resistance P or the sealing performance not meeting the usage requirements of the battery cell housing, and the usage performance and safety performance of the battery cell cannot be guaranteed.

[0062] In this embodiment, the welding portion 11 is formed by high-frequency welding. High-frequency welding is a process that uses high-frequency current to generate resistance heat on the metal surface, heating the workpiece surface to a molten state, and at the same time applying an extrusion force to make the metals fuse with each other to achieve welding. High-frequency welding has the advantages of high material utilization rate, high production efficiency, and high product yield.

[0063] Further, in an optional implementation manner, the housing body 10 is an aluminum member, that is, the material of the housing body 10 is aluminum; in another optional implementation manner, the housing body 10 is a steel member, that is, the material of the housing body 10 is steel.

[0064] According to a battery cell housing provided by the present invention, a receiving cavity is formed inside the housing body, and a welding portion is formed on the first side wall of the housing body. The welding portion includes a first protrusion protruding towards the outside of the housing body and a second protrusion protruding towards the inside of the housing body; the length dimension of the first protrusion in the direction perpendicular to the first side wall is a, 0 < a ≤ 0.05 mm, and the length dimension of the second protrusion in the direction perpendicular to the first side wall is b, 0 < b ≤ 0.15 mm, so as to ensure the structural strength of the welding portion and avoid cracking at the position of the welding portion when the housing body is subjected to impact or pressure. The wall thickness of the housing body is h, in mm; the width dimension of the housing body in the first direction is W, in mm, 0.015 ≤ h / W ≤ 0.055, so as to improve the welding quality of the welding portion, thereby improving the pressure resistance and sealing performance of the position where the welding portion is provided on the housing body, avoiding cracking of the housing body during use, improving the service life of the housing body, and ensuring that the housing body can effectively protect the components inside the battery cell housing.

[0065] According to a battery cell provided by the present invention, it includes the above-mentioned battery cell housing. The battery cell housing has reliable structural strength, thereby reducing the safety performance and service life of the battery cell and meeting the usage requirements of the battery cell under complex working conditions.

[0066] Finally, it should be noted that the above-described embodiments are only specific implementation manners of the present application, used to illustrate the technical solutions of the present application, rather than limiting it. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the technical field can still modify the technical solutions described in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; 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 all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A battery cell housing, characterized in that, The battery cell housing includes: A housing main body having a first side wall, on which a welding portion is formed. The welding portion includes a first protrusion protruding toward the outside of the housing main body and a second protrusion protruding toward the inside of the housing main body; the length dimension of the first protrusion in the direction perpendicular to the first side wall is a, where 0 < a ≤ 0.05 mm; the length dimension of the second protrusion in the direction perpendicular to the first side wall is b, where 0 < b ≤ 0.15 mm; The wall thickness of the housing main body is h, in mm; the width dimension of the housing main body in the first direction is W, in mm, and 0.015 ≤ h / W ≤ 0.

055.

2. The cell housing according to claim 1, characterized in that, 0.15 mm ≤ h ≤ 1.0 mm.

3. The cell housing according to claim 1, characterized in that, The housing main body is formed into a rectangular housing structure. The housing main body includes two first side walls arranged opposite to each other and two second side walls arranged opposite to each other. The first side walls and the second side walls are alternately arranged to enclose the housing main body; the area of the first side wall is smaller than the area of the second side wall.

4. The cell housing according to claim 1, characterized in that, The welding portion is formed into a strip structure. The height dimension of the housing main body in the second direction is H, in mm, and 1 < H / W ≤ 12. The second direction is perpendicular to the first direction and the length direction of the welding portion respectively.

5. The cell housing according to claim 3, characterized in that, The pressure resistance strength P of the welding portion is ≥ 1.2 Mpa; And / or, the flatness of the outer surface of the second side wall is S, where 0 < S ≤ 0.5 mm.

6. The cell housing according to claim 1, characterized in that, The welding portion is formed by high-frequency welding.

7. The cell housing according to claim 1, characterized in that, a < b.

8. The cell housing according to claim 1, characterized in that, An accommodation cavity is formed inside the housing main body, and the accommodation cavity has at least one opening; When the accommodation cavity has one opening, the opening is provided at one end in the length direction of the welding portion; When the accommodation cavity has multiple openings, at least two openings are arranged opposite to each other in the length direction of the welding portion.

9. The cell housing according to claim 1, characterized in that, The housing main body is an aluminum part; or the housing main body is a steel part.

10. A battery cell, characterized in that, Including the battery cell housing according to any one of claims 1 to 9.

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