Casing and cell

Abstract

The application provides a shell and an electric core. The shell comprises a base plate with a mounting surface, wherein the mounting surface is provided with a connected explosion-proof area and a body area, and the explosion-proof area is used for arranging an explosion-proof valve; and a reinforcing part connected to the mounting surface and covering at least part of the connecting part of the explosion-proof area and the body area. The shell and the electric core provided by the application can make the high-temperature gas generated in the shell concentrate on the explosion-proof valve when the electric core is in thermal runaway. Since the reinforcing part is arranged near the explosion-proof valve, when the explosion-proof valve is pressed, the reinforcing part can prevent the area near the explosion-proof valve from being deformed and torn, thereby improving the sealing performance and safety of the shell and effectively preventing the shell from leaking liquid or gas during use.

Description

Technical Field

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

[0002] In the development of battery technology, besides improving the energy density of battery cells, safety is also a crucial issue that cannot be ignored. If the safety of battery cells cannot be guaranteed, then the cells cannot be used. Therefore, how to enhance the safety of battery cells is a technical problem that urgently needs to be solved in battery technology. Utility Model Content

[0003] In view of this, the purpose of this application is to propose a casing and a battery cell to at least partially solve the problem of how to enhance the safety of the battery cell.

[0004] To achieve the above objectives, the first aspect of this application provides a housing comprising: a substrate having a mounting surface, the mounting surface having a connected explosion-proof area and a body area, the explosion-proof area being used to house an explosion-proof valve; and a reinforcing portion connected to the mounting surface and at least partially covering the connection portion between the explosion-proof area and the body area.

[0005] Based on the same inventive concept, the second aspect of this application also provides a battery cell, including a casing as described in the first aspect.

[0006] As can be seen from the above, the housing and battery cell provided in this application, when the battery cell experiences thermal runaway, will cause the high-temperature gas generated inside the housing to act more concentratedly on the explosion-proof valve within the explosion-proof area. Because a reinforcing section is provided at the connection between the explosion-proof area and the main body area, when the explosion-proof valve is under pressure, the reinforcing effect of the reinforcing section prevents deformation and tearing in the area near the explosion-proof valve, thus improving the sealing and safety of the housing and effectively preventing liquid or gas leakage during use. Attached Figure Description

[0007] 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.

[0008] Figure 1 This is a partial cross-sectional view of the outer shell of the first structure according to an embodiment of this application;

[0009] Figure 2 This is a partial perspective view of the outer shell of the second structure according to an embodiment of this application;

[0010] Figure 3This is a partial top view of the outer shell of the second structure according to an embodiment of this application;

[0011] Figure 4 for Figure 3 Schematic diagram of the cross section AA;

[0012] Figure 5 for Figure 4 An enlarged schematic diagram of the first structure in section B before welding;

[0013] Figure 5a for Figure 4 An enlarged schematic diagram of the second structure in part B when it is not welded;

[0014] Figure 5b for Figure 4 An enlarged schematic diagram of the third structure in part B when it is not welded;

[0015] Figure 5c for Figure 4 An enlarged schematic diagram of the fourth structure in section B when it is not welded;

[0016] Figure 5d for Figure 4 An enlarged schematic diagram of the fifth structure in part B when it is not welded;

[0017] Figure 5e for Figure 4 An enlarged schematic diagram of the sixth structure in section B when it is not welded;

[0018] Figure 6 for Figure 4 An enlarged schematic diagram of the seventh structure in part B when it is not welded;

[0019] Figure 6a for Figure 4 An enlarged schematic diagram of the eighth structure in section B before welding;

[0020] Figure 6b for Figure 4 An enlarged schematic diagram of the ninth structure in part B when it is not welded;

[0021] Figure 6c for Figure 4 An enlarged schematic diagram of the tenth structure in Part B when it is not welded;

[0022] Figure 7 for Figure 4 An enlarged schematic diagram of the first structure in section B after welding;

[0023] Figure 7a for Figure 4 An enlarged schematic diagram of the second structure in section B after welding;

[0024] Figure 8 This is a top view schematic diagram of the first extension structure of the reinforcing part of the outer shell according to an embodiment of this application;

[0025] Figure 8a This is a top view schematic diagram of a second extension structure of the reinforcing part of the outer shell according to an embodiment of this application;

[0026] Figure 8b This is a top view schematic diagram of a third extension structure of the reinforcing part of the outer shell according to an embodiment of this application;

[0027] Figure 8c This is a top view schematic diagram of a fourth extension structure of the reinforcing part of the outer shell according to an embodiment of this application;

[0028] Figure 8d This is a top view schematic diagram of the fifth extension structure of the reinforcing part of the outer shell according to an embodiment of this application;

[0029] Figure 8e This is a top view schematic diagram of the sixth extension structure of the reinforcing part of the outer shell according to an embodiment of this application;

[0030] Figure 9 This is a top view schematic diagram of the seventh extension structure of the reinforcing part of the outer shell according to an embodiment of this application;

[0031] Figure 9a This is a top view schematic diagram of the eighth extension structure of the reinforcing part of the outer shell according to an embodiment of this application;

[0032] Figure 10 for Figure 4 Enlarged schematic diagram of the eleventh structure in Part B;

[0033] Figure 11 for Figure 4 Enlarged schematic diagram of the twelfth structure in Part B;

[0034] Figure 12 for Figure 11 A partial explosion diagram of the corresponding outer shell;

[0035] Figure 13 for Figure 4 An enlarged schematic diagram of the thirteenth structure in section B before welding;

[0036] Figure 13a for Figure 4 An enlarged schematic diagram of the thirteenth structure in section B after welding using the first welding method;

[0037] Figure 13b for Figure 4 An enlarged schematic diagram of the thirteenth structure in section B after welding using the second welding method;

[0038] Figure 13c for Figure 4 An enlarged schematic diagram of the fourteenth structure in section B after welding using the first welding method;

[0039] Figure 13d for Figure 4 An enlarged schematic diagram of the fourteenth structure in section B after welding using the second welding method;

[0040] Figure 13e for Figure 4 An enlarged schematic diagram of the fifteenth structure in Part B before welding;

[0041] Figure 14 This is a partially cross-sectional schematic diagram of another structure of the reinforcing part of the outer shell according to an embodiment of this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 100. Substrate; 110. Mounting hole; 120. Mounting surface; 121. First edge; 122. Second edge; 123. Explosion-proof area; 124. Body area;

[0044] 200. Cover plate assembly; 210. Cover plate body; 220. Explosion-proof valve; 221. Explosion-proof protruding end; 222. Weak part; 223. Explosion-proof concave surface; 224. Third chamfer; 225. Fourth chamfer;

[0045] 300, welded section; 300a, first welded section; 300b, second welded section; 310, molten pool;

[0046] 400, Reinforcing part; 410, First sub-part; 420, Second sub-part; 430, First reinforcing body; 440, Second reinforcing body; 450, Third reinforcing body; 451, Clearance through hole; 460, Transition sub-part; 461, Transition protruding end; 462, Root end; 470, Main body sub-part; 471, Reinforcing protruding end; 472, Positioning groove; 480, Groove; 491, First chamfer; 492, Second chamfer;

[0047] 500. Capacity space;

[0048] 600. Shell; 610. Side plate; 620. Top plate; 630. Bottom plate; 640. Open end;

[0049] 700. Exhaust passage. Detailed Implementation

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] Figure 1 A partial cross-sectional schematic diagram of the outer shell of the first structure is shown.

[0056] like Figure 1 In some embodiments, the housing includes a housing 600 and a cover assembly 200. The housing 600 may include a base plate 630, each of the four edges of which is connected to a side plate 610. The edges of the four side plates 610 away from the base plate 630 enclose an opening 640. The cover assembly 200 includes a cover body 210 and an explosion-proof valve 220 disposed on the cover body 210. The cover body 210 covers the opening 640, so that the housing 600 and the cover assembly 200 enclose a receiving space 500 for accommodating a bare battery cell.

[0057] Figure 2 A partial three-dimensional schematic diagram of the shell with the second structure is shown. Figure 3 A partial top view of the shell of the second structure is shown.

[0058] like Figure 2 and Figure 3The housing 600 may have two open ends 640. The housing 600 may include two side plates 610, and a top plate 620 and a bottom plate 630 disposed opposite each other. The side plates 610 are connected between the long edges of the top plate 620 and the long edges of the bottom plate 630. The top plate 620, the bottom plate 630, and the two side plates 610 together form a cylindrical structure, with both ends of the cylindrical structure being open ends 640. The explosion-proof valve 220 may be connected to the top plate 620.

[0059] Taking the casing 600 as an example, if the casing 600 is made of aluminum alloy, not only will the material thickness of the casing 600 be large, but its strength will also be low and its high-temperature resistance will be poor, making it difficult to withstand large pressures. When a battery cell using this casing experiences thermal runaway, the casing 600 is prone to burn-through, and the risk of thermal diffusion from the battery cell is high. At the same time, the thick casing 600 will also occupy too much of the space 500, resulting in a lower energy density for the battery cell.

[0060] The applicant discovered that if steel is used to manufacture the casing 600, the material thickness of the casing 600 can be designed to be smaller due to the relatively high strength and good high temperature resistance of steel, thereby increasing the energy density of the battery cell.

[0061] However, taking the second type of casing as an example, when the casing 600 is designed to be thinner, if the battery cell experiences thermal runaway, there is a higher risk of deformation, tearing, and leakage in the area of ​​the casing 600 near the explosion-proof valve 220, resulting in poor safety performance of the battery cell.

[0062] To address the aforementioned issues, embodiments of this application provide a housing.

[0063] Figure 4 Showing Figure 3 A schematic diagram of the cross-section AA in the middle. Figure 5 Showing Figure 4 An enlarged schematic diagram of the first structure in section B before welding.

[0064] like Figure 3 , Figure 4 and Figure 5 The housing provided in this application embodiment includes: a substrate 100 having a mounting surface 120, the mounting surface 120 having a connected explosion-proof area 123 and a body area 124, the explosion-proof area 123 being used to house an explosion-proof valve 220; and a reinforcing part 400 connected to the mounting surface 120 and at least partially covering the connection portion between the explosion-proof area 123 and the body area 124.

[0065] For example, the substrate 100 may be the cover plate body 210, or may be at least one of the top plate 620, bottom plate 630 and side plate 610, and the receiving space 500 is located on one side of the substrate 100 along its thickness direction.

[0066] For example, the substrate 100, the explosion-proof valve 220 and the reinforcing part 400 may be made of the same material (e.g., all of them are SUS304 stainless steel) or different materials, but it is necessary to ensure that the three can be welded together.

[0067] For example, the surfaces of the substrate 100 disposed opposite each other along the thickness direction can be configured as mounting surfaces 120.

[0068] For example, the body area 124 may be set around the explosion-proof area 123.

[0069] For example, a through hole for mounting the explosion-proof valve 220 can be formed in the explosion-proof area 123, or the explosion-proof area 123 and the body area 124 of the substrate 100 can be integrally formed, and the explosion-proof valve 220 can be constructed on the substrate 100 in the explosion-proof area 123 by processes such as stamping or etching.

[0070] The reinforcement part 400 is connected to the mounting surface 120, which is equivalent to thickening the structure at its location by means of the reinforcement part 400, thereby strengthening the structure of the explosion-proof valve 220 or the area near it.

[0071] When the battery cell, including the casing of this embodiment, experiences thermal runaway, the high-temperature gas generated inside the casing 600 will concentrate on the explosion-proof valve 220 within the explosion-proof zone 123. Because a reinforcing part 400 is provided at the connection between the explosion-proof zone 123 and the main body zone 124, when the explosion-proof valve 220 is under pressure, the reinforcing effect of the reinforcing part 400 prevents deformation and tearing in the area near the explosion-proof valve 220, thus improving the sealing and safety of the casing and effectively preventing liquid or gas leakage during use.

[0072] like Figure 5 In some embodiments, a through mounting hole 110 is formed in the explosion-proof area 123, the explosion-proof valve 220 is independent of the body area 124, and at least a portion of the explosion-proof valve 220 is placed in the mounting hole 110; the reinforcing part 400 is provided at least in a portion of the area along the edge of the explosion-proof valve 220, and the reinforcing part 400 covers the edge of the explosion-proof valve 220 and the edge of the mounting hole 110 radially along the mounting hole 110.

[0073] It should be noted that the shape of the mounting hole 110 corresponds to the shape of the explosion-proof valve 220, that is, the edge of the mounting hole 110 and the edge of the explosion-proof valve 220 are close to each other.

[0074] by Figure 5Taking the structure and orientation shown as an example, the reinforcing part 400 is located at the joint between the main body region 124 and the explosion-proof valve 220. The left side of the reinforcing part 400 corresponds to the main body region 124, and the right side corresponds to the explosion-proof valve 220. After the reinforcing part 400 is connected to the main body region 124 and / or the explosion-proof valve 220, at least the area near the edge of the mounting hole 110 and the area near the edge of the explosion-proof valve 220 can be reinforced simultaneously. This makes the main body region 124 and the explosion-proof region 123 less prone to deformation and tearing, which helps to further improve the sealing and safety of the shell.

[0075] like Figure 5 In some embodiments, a receiving space 500 is formed within the housing, the inner side of the substrate 100 is close to the receiving space 500, and the outer side of the substrate 100 is away from the receiving space 500; the reinforcing portion 400 is independent of at least one of the body region 124 and the explosion-proof region 123, along a first direction (e.g., Figure 5 In the Z direction, the reinforcing part 400 has a reinforcing protrusion 471 that is away from the mounting surface 120 and is located inside the substrate 100; the first direction is the thickness direction of the substrate 100.

[0076] In this embodiment, the reinforcing part 400 can be independent of both the main body region 124 and the explosion-proof region 123 (e.g., an explosion-proof valve 220 disposed in the explosion-proof region 123 and independent of the main body region 124, or a portion of the substrate 100 with pressure relief function located in the explosion-proof region 123). Alternatively, it can be independent of only one of the main body region 124 and the explosion-proof region 123, and integrally connected to the other.

[0077] by Figure 5 Taking the structure and orientation shown as an example, the reinforcing part 400 is entirely located within the receiving space 500, and correspondingly, the surface of the substrate 100 near the receiving space 500 serves as the mounting surface 120. As can be seen from the foregoing, when assembling the battery cell, the bare battery cell is also placed within the receiving space 500. When the bare battery cell experiences thermal runaway, it will expand. If the expanded bare battery cell is too close to the explosion-proof area 123, it may obstruct the opening of the explosion-proof valve 220 and also encroach on the gas flow channel within the receiving space 500, preventing the gas within the receiving space 500 from flowing smoothly and promptly to the explosion-proof valve 220 and being discharged through the opened explosion-proof valve 220.

[0078] At the same time, by placing the reinforcing part 400 entirely within the accommodating space 500, the appearance of the housing can be made neater, and interference between the reinforcing part 400 and external circuits or busbars can be prevented.

[0079] For example, when a bare battery cell is disposed within the accommodating space 500, the bare battery cell is wrapped with an insulating film (i.e., Mylar film); simultaneously, an insulating base plate is disposed at the bottom of the bare battery cell away from the explosion-proof valve 220. The insulating film and the base plate ensure insulation between the reinforcing part 400, the substrate 100, the explosion-proof valve 220, and the bare battery cell, preventing the bare battery cell from directly contacting the casing and causing an internal short circuit. Furthermore, if the reinforcing protrusion 471 is closer to the bare battery cell than the explosion-proof valve 220, the reinforcing protrusion 471 can limit the bare battery cell in the first direction, further preventing direct contact between the bare battery cell and the explosion-proof valve 220, thus avoiding a short circuit to the casing.

[0080] Figure 5a Showing Figure 4 An enlarged schematic diagram of the second structure in section B when it is not welded.

[0081] like Figure 5a In some embodiments, the reinforcing protrusion 471 is located on the outside of the substrate 100.

[0082] by Figure 5a Taking the structure and orientation shown as an example, the reinforcing part 400 is entirely located outside the receiving space 500, and correspondingly, the surface of the substrate 100 away from the receiving space 500 serves as the mounting surface 120. Since the reinforcing part 400 no longer occupies the receiving space 500, the saved space can be used to install bare cells, which helps to improve the space utilization of the receiving space 500 and helps to improve the energy density of the cells using the casing of this embodiment.

[0083] Figure 5b Showing Figure 4 An enlarged schematic diagram of the third structure in section B when it is not welded.

[0084] like Figure 5b In some embodiments, the reinforcing protrusion 471 is located on the inner and outer sides of the substrate 100.

[0085] by Figure 5b Taking the structure and orientation shown as an example, the surfaces of the substrate 100 near the receiving space 500 and away from the receiving space 500 both serve as mounting surfaces 120. Correspondingly, each of the two mounting surfaces 120 is connected to a reinforcing part 400, that is, reinforcing parts 400 are provided both inside and outside the receiving space 500. In this embodiment, reinforcing parts 400 are provided on opposite sides of the substrate 100 and opposite sides of the explosion-proof valve 220 along the first direction, which can further improve the reinforcing effect of the reinforcing parts 400, prevent deformation and tearing in the area near the explosion-proof valve 220, and significantly improve the sealing and safety of the casing.

[0086] Furthermore, this embodiment can also achieve the aforementioned beneficial effect of providing the reinforcing part 400 only within the accommodating space 500, which will not be elaborated here.

[0087] like Figure 5 , Figure 5a and Figure 5b In some embodiments, an explosion-proof valve 220 is provided in the explosion-proof area 123. Along the first direction, the explosion-proof valve 220 has an explosion-proof protrusion 221 that is away from the mounting surface 120. The explosion-proof protrusion 221 is located inside the substrate 100.

[0088] in, Figure 5 The structure shown has an explosion-proof protrusion 221 located inside the substrate 100, and a reinforcing protrusion 471 located inside the substrate 100.

[0089] Figure 5a The structure shown has an explosion-proof protrusion 221 located inside the substrate 100, and a reinforcing protrusion 471 located outside the substrate 100.

[0090] Figure 5b The structure shown has an explosion-proof protrusion 221 located inside the substrate 100, and a reinforcing protrusion 471 located on both the inside and outside of the substrate 100.

[0091] by Figure 5 Taking the structure and orientation shown as an example, the explosion-proof valve 220 is located within the receiving space 500, which makes the appearance of the housing cleaner and prevents the explosion-proof valve 220 from interfering with external circuits or busbars. At the same time, the recess of the explosion-proof valve 220 into the receiving space 500 also protects the explosion-proof valve 220 from damage caused by external impacts during transportation, assembly, and use.

[0092] Figure 5c Showing Figure 4 An enlarged schematic diagram of the fourth structure in section B when it is not welded; Figure 5d Showing Figure 4 An enlarged schematic diagram of the fifth structure in part B when it is not welded; Figure 5e Showing Figure 4 An enlarged schematic diagram of the sixth structure in section B when it is not welded.

[0093] like Figure 5c , Figure 5d and Figure 5e In some embodiments, along the first direction, the explosion-proof valve 220 has an explosion-proof protrusion 221 away from the mounting surface 120, and the explosion-proof protrusion 221 is located on the outside of the substrate 100.

[0094] in, Figure 5cThe structure shown has an explosion-proof protrusion 221 located on the outside of the substrate 100, and a reinforcing protrusion 471 located on the inside of the substrate 100.

[0095] Figure 5d The structure shown has an explosion-proof protrusion 221 located on the outside of the substrate 100, and a reinforcing protrusion 471 located on the outside of the substrate 100.

[0096] Figure 5e The structure shown has an explosion-proof protrusion 221 located on the outer side of the substrate 100, and a reinforcing protrusion 471 located on both the inner and outer sides of the substrate 100.

[0097] by Figure 5c Taking the structure and orientation shown as an example, the explosion-proof valve 220 is located outside the accommodating space 500. Since the explosion-proof valve 220 no longer occupies the accommodating space 500, the space saved can be used to install bare battery cells, which helps to improve the space utilization of the accommodating space 500 and helps to improve the energy density of the battery cells.

[0098] like Figure 5 and Figure 5d In some embodiments, the reinforcing protrusion 471 and the explosion-proof protrusion 221 are located on the same side of the substrate 100.

[0099] When the reinforcing protrusion 471 and the explosion-proof protrusion 221 are located on the same side of the substrate 100, the reinforcing part 400 and the explosion-proof valve 220 have a height overlap in the first direction. This makes the overall height of the reinforcing part 400, the substrate 100 and the explosion-proof valve 220 smaller in the first direction after they are connected. The space saved can be used to reduce the size of the battery cell or to set up a bare battery cell, which helps to improve the energy density of the battery cell.

[0100] like Figure 5 In some embodiments, both the reinforcing protrusion 471 and the explosion-proof protrusion 221 are located inside the substrate 100.

[0101] In this embodiment, the reinforcing portion 400 disposed within the accommodating space 500 utilizes the height space of the explosion-proof valve 220, which reduces the additional space occupied by the reinforcing portion 400 in the first direction and helps to improve the energy density of the battery cell. Meanwhile, the beneficial effects achievable in this embodiment are similar to those described above regarding the beneficial effects of disposing the reinforcing portion 400 inside the substrate 100 and the beneficial effects of disposing the explosion-proof valve 220 inside the substrate 100, and will not be repeated here.

[0102] As can be seen from the foregoing embodiments, the placement of the reinforcing part 400 and the explosion-proof valve 220 is quite flexible and can be designed according to the actual needs of different battery cells, so that the battery cells can meet a variety of different usage scenarios.

[0103] like Figure 5 In some embodiments, along the first direction, the distance between the reinforcing protrusion 471 and the explosion-proof protrusion 221 is H1, where 0mm≤H1≤10mm.

[0104] It should be noted that when the reinforcing protrusion 471 and the explosion-proof protrusion 221 are located on the same side of the substrate 100, H1 is smaller; when the reinforcing protrusion 471 and the explosion-proof protrusion 221 are located on opposite sides of the substrate 100, H1 is larger.

[0105] For example, H1 can be 0mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm.

[0106] If H1 is too large, the height of the reinforcing part 400 along the first direction may be too large, causing the reinforcing part 400 to occupy too much of the accommodating space 500, which in turn leads to a lower energy density of the battery cell.

[0107] To avoid the above problems, in this embodiment, H1 is designed to be 0mm≤H1≤10mm. This allows the reinforcing part 400 to effectively strengthen the structure it covers while avoiding the reinforcing part 400 occupying too much of the accommodating space 500, which helps to improve the energy density of the battery cell.

[0108] like Figure 5 In some embodiments, along the first direction, the distance between the explosion-proof protrusion 221 and the surface of the adjacent body region 124 is H2, and the material thickness of the explosion-proof valve 220 is t1, where 2*t1≤H2≤10*t1.

[0109] It should be noted that, in Figure 5 In the structure shown, since the surface of the body region 124 and the surface of part of the explosion-proof region 123 (i.e., the part surrounding the explosion-proof protrusion 221) are located in the same plane, H2 is marked in the explosion-proof region 123 for clarity, but it still represents the distance between the explosion-proof protrusion 221 and the adjacent surface of the body region 124.

[0110] For example, the explosion-proof valve 220 can be made of metal sheet and can be formed with an explosion-proof protrusion 221 by stamping or other means.

[0111] For example, H2 can be 0.2mm, 0.4mm, 0.5mm, 0.6mm, 0.8mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm.

[0112] The explosion-proof valve 220 is equipped with an explosion-proof protrusion 221, which can improve the structural strength of the area where the explosion-proof protrusion 221 is located, helping to reduce the risk of deformation of the explosion-proof valve 220. If H2 is too small, the effect of the explosion-proof protrusion 221 in improving the structural strength of the explosion-proof valve 220 will not be significant. If H2 is too large, the explosion-proof protrusion 221 will occupy too much space in the first direction of the battery cell, which will adversely affect the energy density of the battery cell.

[0113] To avoid the above problems, this embodiment designs H2 as 2*t1≤H2≤10*t1. While improving the structural strength of the explosion-proof valve 220, it can also reduce the space occupied by the explosion-proof valve 220 in the first direction, which helps to improve the energy density of the battery cell.

[0114] like Figure 5 In some embodiments, the explosion-proof valve 220 is provided with a weak part 222, the thickness of which is less than the thickness of the part of the explosion-proof valve 220 excluding the weak part 222; the minimum interval between the weak part 222 and the reinforcing part 400 along the plane of the mounting surface 120 is L10, 0.5mm≤L10≤20mm.

[0115] For example, the weak portion 222 is at least partially provided at the explosion-proof protrusion 221.

[0116] For example, the weak part 222 can be formed by etching or by stamping. The specific forming method can be selected according to the material, thickness, structure of the explosion-proof valve 220 or the connection method between the explosion-proof valve 220 and the body area 124, and is not limited here.

[0117] For example, L10 can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm, 15mm, 15.5mm, 16mm, 16.5mm, 17mm, 17.5mm, 18mm, 18.5mm, 19mm, 19.5mm, or 20mm.

[0118] Since the reinforcing part 400 is located near the edge of the explosion-proof valve 220, if L10 is too large, the weak part 222 will only be located at the center of the explosion-proof valve 220. In the event of thermal runaway of the battery cell, there will be a risk of insufficient pressure relief area, and the high-temperature gas inside the battery cell will be difficult to be discharged in time. If L10 is too small, when connecting (e.g., welding) the reinforcing part 400 or forming the reinforcing part 400 (e.g., forming the reinforcing part 400 by stamping the substrate 100), the weak part 222 will be affected by heat or stress, which will cause the weak part 222 to malfunction and fail to relieve pressure.

[0119] To avoid the above problems, this embodiment designs L10 to be 0.5mm≤L10≤20mm. While avoiding the thermal or stress effects on the weak part 222, it can also ensure that the explosion-proof valve 220 has a sufficient pressure relief area. In the event of thermal runaway of the battery cell, the weak part 222 can be broken and opened normally to relieve pressure in time, which helps to improve the safety performance of the battery cell.

[0120] When an explosion-proof valve 220 is installed in the explosion-proof zone 123, the connection relationship between the reinforcing part 400, the main body zone 124 and the explosion-proof zone 123 can be as described in the following embodiments.

[0121] like Figure 5 In some embodiments, the reinforcing part 400, the body region 124 and the explosion-proof region 123 are independent of each other and are fixedly connected.

[0122] For example, the reinforcing part 400, the body area 124, and the explosion-proof area 123 can be connected by welding, riveting, or bonding.

[0123] For example, when the reinforcing part 400, the body area 124 and the explosion-proof area 123 are welded or bonded, two of the three can be pre-connected first, and then the three can be connected into a whole.

[0124] The body area 124, the explosion-proof area 123, and the reinforcing part 400 are independent of each other, which can simplify the structure of each of them, help reduce the molding difficulty and manufacturing cost of each of them, and facilitate mass production.

[0125] like Figure 5When the reinforcing part 400 is disposed at the connection between the main body region 124 and the explosion-proof region 123, after the three are fixedly connected, the thickness of the main body region 124 adjacent to the explosion-proof region 123 is increased by the reinforcing part 400, which also increases the thickness of the explosion-proof region 123 adjacent to the main body region 124. This helps to prevent deformation and tearing of the main body region 124 and the explosion-proof region 123, and helps to improve the sealing and safety of the shell. At the same time, since the reinforcing part 400 can be a one-piece molded structure, the connection strength between the main body region 124 and the explosion-proof valve 220 can be improved by the reinforcing part 400.

[0126] Figure 6 Showing Figure 4 An enlarged schematic diagram of the seventh structure in section B when it is not welded.

[0127] like Figure 6 In some embodiments, the reinforcing part 400 is integrally formed and connected to the body region 124.

[0128] It should be noted that, Figure 6 The example shown is based on the reinforcement 400 being disposed on the inner side of the substrate 100. When the reinforcement 400 is located on the outer side of the substrate 100, the reinforcement 400 can also be integrally formed and connected with the body region 124. When the reinforcement 400 is located on both the outer and inner sides of the substrate 100, at least one side of the reinforcement 400 can be integrally formed and connected with the body region 124.

[0129] For example, the reinforcing portion 400 in this embodiment can be formed by a stamping process during the fabrication of the substrate 100.

[0130] The reinforcing part 400 is integrally formed and connected to the body region 124. On the one hand, this helps to improve the connection strength between the reinforcing part 400 and the body region 124, thereby making the reinforcement effect of the reinforcing part 400 on the body region 124 more stable and reliable. On the other hand, it also helps to simplify the assembly process of the shell, improve assembly efficiency, and facilitate mass production.

[0131] Figure 6a Showing Figure 4 An enlarged schematic diagram of the eighth structure in section B before welding.

[0132] like Figure 6a In some embodiments, the reinforcing part 400 is integrally formed and connected to the explosion-proof area 123.

[0133] It should be noted that, Figure 6aThe example shown is based on the reinforcement 400 being located inside the substrate 100 and on the same side as the explosion-proof protrusion 221. When the reinforcement 400 is located inside the substrate 100 and on the opposite side of the explosion-proof protrusion 221, the reinforcement 400 can be integrally formed and connected to the explosion-proof area 123. When the reinforcement 400 is located outside the substrate 100 and on the same side or opposite side of the explosion-proof protrusion 221, the reinforcement 400 can be integrally formed and connected to the explosion-proof area 123. When the reinforcement 400 is located on both the inside and outside of the substrate 100, and the explosion-proof protrusion 221 is located on either the inside or outside of the substrate 100, the reinforcement 400 can be integrally formed and connected to the explosion-proof area 123.

[0134] For example, when the explosion-proof valve 220 located in the explosion-proof area 123 is independent of the body area 124, the reinforcing part 400 in this embodiment can be formed by a stamping process during the preparation of the explosion-proof valve 220.

[0135] The reinforcing part 400 is integrally formed and connected to the explosion-proof area 123. On the one hand, this helps to improve the connection strength between the reinforcing part 400 and the explosion-proof area 123, thereby making the reinforcing effect of the reinforcing part 400 on the explosion-proof valve 220 more stable and reliable. On the other hand, it also helps to simplify the assembly process of the housing, improve assembly efficiency, and facilitate mass production.

[0136] Figure 6b Showing Figure 4 An enlarged schematic diagram of the ninth structure in section B when it is not welded.

[0137] like Figure 6b In some embodiments, the body region 124 and the explosion-proof region 123 are integrally formed and connected, the reinforcing part 400 is independent of the body region 124 and the explosion-proof region 123, and the reinforcing part 400 is connected to the body region 124 and the explosion-proof region 123.

[0138] It should be noted that, with Figure 6b Taking the structure shown as an example, the explosion-proof valve 220 may not have the explosion-proof protrusion 221, that is, the explosion-proof valve 220 may be a sheet-like structure. Furthermore, the explosion-proof valve 220 without the explosion-proof protrusion 221 can be used in various situations listed in the aforementioned embodiments, such as the body region 124 and the explosion-proof region 123 being integrally formed and connected, the body region 124 and the explosion-proof region 123 being independent of each other, the explosion-proof region 123 being integrally formed and connected to the reinforcing part 400, and the explosion-proof region 123 being independent of the reinforcing part 400.

[0139] When the explosion-proof valve 220 is not equipped with the explosion-proof protrusion 221, the space occupied by the explosion-proof valve 220 can be reduced by 500, which helps to improve the energy density of the battery cell including the casing.

[0140] The main body area 124 and the explosion-proof area 123 are connected by an integral molding process, which helps to improve the sealing performance and overall strength of the shell, and can further reduce the deformation and tearing of the shell under the impact of high-temperature gases inside. At the same time, it can also eliminate the connection process between the main body area 124 and the explosion-proof area 123, which helps to improve assembly efficiency.

[0141] When the reinforcing part 400 is connected to the main body area 124 and the explosion-proof area 123, the reinforcing part 400 can simultaneously strengthen the main body area 124 and the explosion-proof area 123, which helps to reduce the risk of deformation and tearing of the main body area 124 and the explosion-proof area 123.

[0142] Figure 6c Showing Figure 4 An enlarged schematic diagram of the tenth structure in section B before welding.

[0143] like Figure 6c In some embodiments, the main body region 124 is integrally formed with a first reinforcing body 430, and the explosion-proof region 123 is integrally formed with a second reinforcing body 440. The first reinforcing body 430 and the second reinforcing body 440 are joined together to form a reinforcing part 400.

[0144] For example, the edge of the first reinforcing body 430 away from the mounting surface 120 and close to the second reinforcing body 440 is chamfered, and similarly, the edge of the second reinforcing body 440 away from the mounting surface 120 and close to the first reinforcing body 430 is also chamfered. When the first reinforcing body 430 and the second reinforcing body 440 are welded, the two chamfers can be used to position the welding head of the welding equipment, or as welding bevels, which helps to improve the welding quality.

[0145] It should be noted that, Figure 6c The example shown is based on the reinforcement 400 being located on the outer side of the substrate 100. When the reinforcement 400 is located on the inner side of the substrate 100, and when the reinforcement 400 is located on both the outer and inner sides of the substrate 100, the reinforcement 400 can be configured as a structure formed by combining the first reinforcement body 430 and the second reinforcement body 440.

[0146] The first reinforcing body 430 is integrally formed and connected to the body region 124, which helps to improve the connection strength between the reinforcing part 400 and the body region 124. Similarly, the second reinforcing body 440 is integrally formed and connected to the explosion-proof region 123, which also helps to improve the connection strength between the reinforcing part 400 and the explosion-proof region 123. At the same time, since the first reinforcing body 430 and the second reinforcing body 440 have a large height along the first direction, the connection area between them is also correspondingly large when they are connected. On the one hand, this can improve the connection strength and reliability between them, and on the other hand, it can also help to improve the sealing performance between the body region 124 and the explosion-proof region 123, which helps to improve the safety of the battery cell, including the outer casing.

[0147] like Figure 5a In some embodiments, at least a portion of the edge of the surface of the reinforcing portion 400 near the mounting surface 120 is formed with a first chamfer 491.

[0148] For example, the first chamfer 491 may be provided around the edge of the surface of the reinforcement 400 near the mounting surface 120.

[0149] The reinforcement 400 is provided with a first chamfer 491, which can reduce the stress concentration of the reinforcement 400 on the substrate 100 and / or the explosion-proof valve 220.

[0150] by Figure 5a The structure and orientation shown are used as an example for explanation. When a bare cell in the containment space 500 experiences thermal runaway, the gas generated by the bare cell will push the reinforcing part 400 outward. If the surface of the reinforcing part 400 near the mounting surface 120 has sharp edges, when the reinforcing part 400 is compressed, the sharp edges may exert excessive force on the structural components (e.g., substrate 100 or explosion-proof valve 220) in contact with it, thereby causing the structural components to deform or tear.

[0151] If a first chamfer 491 is provided at the aforementioned edge, when the reinforcing part 400 is compressed, the force exerted by the reinforcing part 400 on the structural component in contact with it can be applied to the structural component more evenly, which helps to reduce the risk of deformation or tearing of the structural component.

[0152] like Figure 5 In some embodiments, at least a portion of the edge of the surface of the reinforcement 400 away from the mounting surface 120 is formed with a second chamfer 492.

[0153] For example, the second chamfer 492 may be provided around the edge of the surface of the reinforcement 400 that is away from the mounting surface 120.

[0154] by Figure 5The structure and orientation shown are used as an example for explanation. When thermal runaway occurs in the bare cell within the accommodating space 500, the bare cell will expand. If the surface of the reinforcing part 400 away from the mounting surface 120 has sharp edges, when the expanded bare cell comes into contact with the sharp edges, due to stress concentration, the sharp edges may exert excessive force on the bare cell, causing the separator inside the bare cell to be cut, and the bare cell may be at risk of internal short circuit.

[0155] If a second chamfer 492 is provided at the aforementioned edge, even if the expanded bare cell comes into contact with the reinforcing part 400, the force exerted by the reinforcing part 400 on the bare cell can be applied to the bare cell more evenly, which can protect the bare cell and reduce the risk of internal short circuit after the bare cell is damaged.

[0156] It should be noted that the reinforcing part 400 can be provided with a first chamfer 491 and a second chamfer 492 at the same time. In this case, the housing 600 can have the beneficial effects of providing the first chamfer 491 and the second chamfer 492 mentioned above, which will not be elaborated here.

[0157] like Figure 5a In some embodiments, the explosion-proof valve 220 has an explosion-proof protrusion 221 away from the mounting surface 120, and at least a portion of the circumferential edge of the explosion-proof protrusion 221 is formed with a third chamfer 224.

[0158] For example, the third chamfer 224 may be provided around the edge of the explosion-proof protrusion 221.

[0159] by Figure 5a The structure and orientation shown are used as an example for explanation. If the surface of the explosion-proof protrusion 221 has sharp edges, when the expanded bare cell comes into contact with the sharp edges, due to stress concentration, the sharp edges may exert excessive force on the bare cell, causing the diaphragm inside the bare cell to be cut, and the bare cell may have the risk of internal short circuit.

[0160] If a third chamfer 224 is provided at the aforementioned edge, even if the expanded bare battery cell comes into contact with the explosion-proof valve 220, the force exerted by the explosion-proof valve 220 on the bare battery cell can be applied to the bare battery cell more evenly, which can protect the bare battery cell and reduce the risk of internal short circuit after the bare battery cell is damaged.

[0161] like Figure 5a In some embodiments, the explosion-proof valve 220 has an explosion-proof protruding end 221 away from the mounting surface 120, and the surface of the explosion-proof valve 220 that is disposed opposite to the explosion-proof protruding end 221 in a first direction is an explosion-proof concave surface 223, and at least a portion of the edge of the explosion-proof concave surface 223 is formed with a fourth chamfer 225.

[0162] For example, the fourth chamfer 225 may be provided around the edge of the explosion-proof concave surface 223.

[0163] by Figure 5a The structure and orientation shown are used as an example for explanation. When a bare battery cell in the containment space 500 experiences thermal runaway, the gas generated by the bare battery cell will push outwards to the explosion-proof protrusion 221. The fourth chamfer 225 set at the edge of the explosion-proof concave surface 223 can prevent stress concentration in the explosion-proof valve 220 under pressure and prevent the explosion-proof valve 220 from deforming.

[0164] In some embodiments, at least one of the first chamfer 491, the second chamfer 492, the third chamfer 224, and the fourth chamfer 225 includes a rounded corner, and the radius of the rounded corner is R, 0.05mm≤R≤5mm.

[0165] For example, R can be 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm.

[0166] For example, when at least two of the first chamfer 491, the second chamfer 492, the third chamfer 224 and the fourth chamfer 225 include rounded corners, the radii of the rounded corners of the at least two chamfers may be the same or different.

[0167] If R is too large, the effective connection area of ​​the reinforcing part 400 may be small, which may adversely affect the connection strength between the reinforcing part 400 and the main body area 124 or the explosion-proof area 123; or, it may also result in a small area where the explosion-proof valve 220 has a weak point 222, which may prevent the gas in the containment space 500 from being discharged in time when the bare cell experiences thermal runaway, thus adversely affecting the safety performance of the cell. If R is too small, the beneficial effects achieved by setting the first chamfer 491, the second chamfer 492, the third chamfer 224 or the fourth chamfer 225 will not be obvious.

[0168] To avoid the above problems, this embodiment designs R to be 0.05mm≤R≤5mm. On the one hand, this makes the beneficial effects achieved by setting the first chamfer 491, the second chamfer 492, the third chamfer 224 or the fourth chamfer 225 more obvious. On the other hand, it also helps to improve the connection strength between the reinforcing part 400 and the main body area 124 or the explosion-proof area 123, improve the exhaust capacity of the explosion-proof valve 220, and thus improve the safety performance of the shell.

[0169] like Figure 5 In some embodiments, the thickness of the substrate 100 is t, where 0.1 mm ≤ t ≤ 0.5 mm.

[0170] For example, t can be 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm.

[0171] If t is too large, the overall weight of the casing will be too high, which is not conducive to achieving a lightweight design for the battery cell, including the casing. If t is too small, the structural strength of the casing may be low, and the risk of deformation or tearing of the casing is higher in the event of thermal runaway of the bare battery cell.

[0172] To avoid the above problems, this embodiment designs t to be 0.1mm≤t≤0.5mm. This ensures that the structural strength of the casing meets the design requirements and is not prone to deformation or tearing, while also keeping the overall weight and manufacturing cost of the casing low, thus meeting the lightweight design requirements for cost reduction and weight reduction of the battery cell.

[0173] like Figure 5 In some embodiments, the material thickness of the explosion-proof valve 220 is t1, where 0.1mm≤t1≤0.5mm.

[0174] For example, t1 can be 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm.

[0175] If t1 is too large, it will be more difficult to form the explosion-proof protrusion 221 or the weak part 222 of the explosion-proof valve 220, resulting in a higher manufacturing cost for the explosion-proof valve 220. At the same time, a large t1 will also result in a heavier explosion-proof valve 220, which may make opening difficult and hinder the discharge of gases generated during thermal runaway of the bare battery cell. If t1 is too small, the structural strength of the explosion-proof valve 220 will be low, making it prone to deformation or tearing under external impact, which will not only affect the sealing performance of the battery cell but also cause the explosion-proof valve 220 to fail.

[0176] To avoid the above problems, this embodiment designs t1 to be 0.1mm≤t1≤0.5mm. This ensures that the structural strength of the explosion-proof valve 220 meets the design requirements and is not prone to deformation or tearing. It also keeps the overall weight and manufacturing cost of the explosion-proof valve 220 low. This ensures that the explosion-proof valve 220 opens smoothly and that the gas generated by the bare battery cell can be discharged in time, which helps to improve the safety and sealing of the battery cell.

[0177] In some embodiments, the absolute value of the difference between the thickness of the substrate 100 and the material thickness of the explosion-proof valve 220 is not greater than 0.2 mm.

[0178] For example, t can be greater than t1, less than t1, or equal to t1.

[0179] For example, the absolute value of the difference between t and t1 can be 0, 0.05 mm, 0.1 mm, 0.15 mm or 0.2 mm.

[0180] If the absolute value of the difference between t and t1 is too large, stress concentration will occur at the connection between the main body area 124 and the explosion-proof area 123, which will have an adverse effect on the connection strength between the two.

[0181] To avoid the above problems, this embodiment designs the absolute value of the difference between t and t1 to be no greater than 0.2mm, which can prevent stress concentration at the connection between the main body area 124 and the explosion-proof area 123, and help improve the connection strength between the two, thereby improving the sealing and safety of the shell.

[0182] Figure 7 Showing Figure 4 An enlarged schematic diagram of the first structure in section B after welding.

[0183] like Figure 7 In some embodiments, an explosion-proof valve 220 is provided in the explosion-proof area 123, and the reinforcing part 400 is welded to at least one of the body area 124 and the explosion-proof area 123 to form a welded part 300 extending around the explosion-proof area 123.

[0184] For example, when the explosion-proof area 123 is provided with a mounting hole 110 and the explosion-proof valve 220 is at least partially disposed within the mounting hole 110, the welded portion 300 is disposed along the edge of the mounting hole 110.

[0185] Welding the reinforcing portion 400 to at least one of the body region 124 and the explosion-proof region 123 into a single unit is equivalent to increasing the thickness of the body region 124 near the weld portion 300, or increasing the thickness of the explosion-proof region 123 near the weld portion 300, by at least the reinforcing portion 400. Figure 7 It can be seen that although the welded part 300 is the connection between the main body area 124 and the explosion-proof area 123, the reinforcing part 400 located at this position is an integrally formed structure. Since the integrally formed reinforcing part 400 has a large strength, it can improve the strength of the welded part 300 at the corresponding position.

[0186] Figure 7a Showing Figure 4 An enlarged schematic diagram of the second structure in section B after welding.

[0187] like Figure 5a and Figure 7aIn some embodiments, when the reinforcing portion 400 is located outside the substrate 100, a positioning groove 472 is formed on the surface of the reinforcing portion 400 away from the mounting surface 120, and the welding portion 300 is disposed along the positioning groove 472 and covers the positioning groove 472.

[0188] For example, the surface of the reinforcing part 400 can be stamped to form a positioning groove 472. Correspondingly, a protrusion is formed on the surface of the reinforcing part 400 near the mounting surface 120. The protrusion can be used to make the reinforcing part 400 form an interference fit with the body region 124 and / or the explosion-proof region 123, which helps to improve the welding strength of the reinforcing part 400 with the body region 124 and / or the explosion-proof region 123.

[0189] For example, the extending direction of the positioning groove 472 is the same as the extending direction of the reinforcing part 400.

[0190] If the reinforcing part 400 is located on the outside of the substrate 100, during welding, the welding head of the welding equipment will act on the surface of the reinforcing part 400 that is away from the mounting surface 120. At this time, the positioning groove 472 can assist in the positioning of the welding head. Especially when the body area 124 and the explosion-proof valve 220 provided in the explosion-proof area 123 are independent of each other, the positioning groove 472 can be aligned with the splicing gap between the body area 124 and the explosion-proof valve 220 before welding, so that the maximum weld depth of the welded part 300 formed after welding is aligned with the splicing gap, which helps to improve the connection reliability of the body area 124 and the explosion-proof valve 220.

[0191] Meanwhile, since the positioning groove 472 and the surrounding area will melt to form the welded part 300 after welding, the setting of the positioning groove 472 will not have an adverse effect on the structural strength of the reinforcing part 400 and the strength of the welded part 300.

[0192] like Figure 7 In some embodiments, the weld depth of the welded portion 300 along the first direction is H3, where 0.8*t≤H3≤5*t.

[0193] For example, H3 can be 0.8*t, 1*t, 1.5*t, 2*t, 2.5*t, 3*t, 3.5*t, 4*t, 4.5*t, or 5*t.

[0194] If H3 is too small, it will be difficult for the reinforcing part 400, the main body area 124 and the explosion-proof area 123 to form a reliable connection through the welding part 300, and the welding part 300 will still be at risk of cracking and leaking gas. If H3 is too large, the reinforcing part 400 may be welded through during welding, which will also result in insufficient strength of the welded welding part 300 and the risk of cracking and leaking gas.

[0195] To avoid the above problems, in this embodiment, H3 is designed to be 0.8*t≤H3≤5*t. This ensures that the reinforcing part 400, the main body area 124 and the explosion-proof area 123 can form a relatively reliable connection through the welding part 300, and also ensures the welding quality of the welding part 300, reducing the risk of cracking and leakage in the welding part 300.

[0196] like Figure 7 In some embodiments, the weld width direction of the welded portion 300 (e.g., Figure 7 The X direction in the welded section intersects with the extension direction of the welded section 300, and the weld width of the welded section 300 is L1, where 1*t≤L1≤5*t.

[0197] For example, L1 can be 1*t, 1.5*t, 2*t, 2.5*t, 3*t, 3.5*t, 4*t, 4.5*t or 5*t.

[0198] If L1 is too small, it will be difficult for the reinforcing part 400, the main body area 124 and the explosion-proof area 123 to form a reliable connection through the welding part 300, and the welding part 300 will still be at risk of cracking and leaking gas; if L1 is too large, it may cause large deformation of the main body area 124 and the explosion-proof area 123, affecting the welding quality of the welding part 300.

[0199] To avoid the above problems, in this embodiment, L1 is designed to be 1*t≤L1≤5*t. This ensures that the reinforcing part 400, the main body area 124 and the explosion-proof area 123 are reliably connected through the welding part 300, and also ensures the welding quality of the welding part 300, reducing the risk of cracking and leakage in the welding part 300.

[0200] like Figure 7 In some embodiments, along the weld width direction of the weld portion 300, the minimum gap between the edge of the weld portion 300 and the edge of the adjacent reinforcing portion 400 is L2, where 0mm≤L2≤2mm.

[0201] For example, along the weld width direction, the center line of the reinforcing portion 400 and the center line of the weld portion 300 can be aligned or offset.

[0202] For example, L2 can be 0, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm or 2mm.

[0203] If L2 is too small, the sidewall of the reinforcing part 400 may be welded through when the fusion section 300 is formed, resulting in insufficient welding strength of the fusion section 300 and the risk of cracking and leakage. If L2 is too large, the size of the reinforcing part 400 along the weld width direction needs to be set to be larger, which will not only increase the overall weight and manufacturing cost of the cell, but also cause the reinforcing part 400 to occupy too much space 500, which will reduce the energy density of the cell.

[0204] To avoid the above problems, in this embodiment, L2 is designed to be 0mm≤L2≤2mm. This can ensure the welding quality of the fusion section 300, reduce the risk of cracking and leakage in the fusion section 300, and avoid the reinforcing section 400 occupying too much space 500. This helps to ensure the energy density of the battery cell and also helps to reduce the overall weight and manufacturing cost of the battery cell.

[0205] like Figure 7 In some embodiments, the minimum distance between the weak part 222 of the explosion-proof valve 220 and the welded part 300 along the plane direction of the mounting surface 120 is L3, 0.5mm≤L3≤20mm.

[0206] For example, L3 can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm, 15mm, 15.5mm, 16mm, 16.5mm, 17mm, 17.5mm, 18mm, 18.5mm, 19mm, 19.5mm, or 20mm.

[0207] Since the welded portion 300 is arranged around the edge of the explosion-proof valve 220, if L3 is too large, the weak portion 222 will only be located in the center of the explosion-proof valve 220. In the event of thermal runaway of the battery cell, there will be a risk of insufficient pressure relief area, and the high-temperature gas inside the battery cell will be difficult to be discharged in time. If L3 is too small, when the welded portion 300 is formed, the weak portion 222 will be affected by welding heat and stress concentration, which will lead to abnormality of the weak portion 222 and failure to relieve pressure.

[0208] To avoid the above problems, in this embodiment, L3 is designed to be 0.5mm≤L3≤20mm. This avoids the weak part 222 from being affected by welding heat and stress concentration, while also ensuring that the explosion-proof valve 220 has a sufficient pressure relief area. In the event of thermal runaway of the battery cell, the weak part 222 can be opened normally to relieve pressure in time, which helps to improve the safety performance of the battery cell.

[0209] like Figure 7 In some embodiments, the welded portion 300 includes a weld pool 310, the outer contour of the cross section of the weld pool 310 along the weld width direction is U-shaped.

[0210] Combination Figure 7 For the welded portion 300, the weld pool 310 is located inside the substrate, that is, below the upper surface of the substrate 100. When the outer contour of the weld pool 310 cross-section is U-shaped, the strength of the welded portion 300 can more easily meet the process requirements, which helps to improve the connection strength between the reinforcing portion 400, the body region 124 and the explosion-proof region 123, and helps to improve the safety and sealing of the battery cell.

[0211] like Figure 5 In some embodiments, the height H4 of the reinforcing part 400 along the first direction is 0.5mm≤H4≤3mm.

[0212] For example, H4 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 2mm, 2.5mm or 3mm.

[0213] If H4 is too small, the reinforcing part 400 may be welded through when the fusion part 300 is formed, resulting in insufficient welding strength of the fusion part 300 and the risk of cracking and leakage. If H4 is too large, it will not only increase the overall weight and manufacturing cost of the cell, but also cause the reinforcing part 400 to occupy too much space 500, which will reduce the energy density of the cell.

[0214] To avoid the above problems, in this embodiment, H4 is designed to be 0.5mm≤H4≤3mm. This can not only ensure the welding quality of the fusion section 300 and reduce the risk of cracking and leakage in the fusion section 300, but also avoid the reinforcing section 400 occupying too much space 500, which helps to ensure the energy density of the battery cell and also helps to reduce the overall weight and manufacturing cost of the battery cell.

[0215] like Figure 5 In some embodiments, the reinforcing part 400 includes a main body sub-part 470 disposed on the mounting surface 120, the width of the main body sub-part 470 being L4, where 1mm≤L4≤5mm.

[0216] For example, L4 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm.

[0217] If L4 is too small, on the one hand, it will be difficult to position the reinforcement part 400, the edge of the mounting hole 110 and the edge of the explosion-proof valve 220. On the other hand, when forming the fusion part 300, the side wall of the reinforcement part 400 may be welded through, resulting in insufficient welding strength of the fusion part 300 and the risk of cracking and leakage. If L4 is too large, it will not only increase the overall weight and manufacturing cost of the battery cell, but also cause the reinforcement part 400 to occupy too much space 500, which will reduce the energy density of the battery cell.

[0218] To avoid the above problems, in this embodiment, L4 is designed to be 1mm≤L4≤5mm. This reduces the positioning difficulty between the edge of the reinforcing part 400, the edge of the mounting hole 110, and the edge of the explosion-proof valve 220, which helps to improve the assembly efficiency of the battery cell, ensures the welding quality of the fusion part 300, reduces the risk of rupture and leakage of the fusion part 300, and avoids the reinforcing part 400 occupying too much of the accommodating space 500. This helps to ensure the energy density of the battery cell and reduce the overall weight and manufacturing cost of the battery cell.

[0219] In some embodiments, the hardness of the reinforcing part 400 is greater than the hardness of the substrate 100, and the hardness of the reinforcing part 400 is greater than the hardness of the explosion-proof valve 220.

[0220] The reinforcing part 400 has a higher hardness, which can enhance the reinforcing effect of the reinforcing part 400 on the body area 124 and the explosion-proof area 123, further preventing deformation or tearing of the body area 124 and the explosion-proof area 123, and helping to improve the safety and sealing of the battery cell.

[0221] In some embodiments, the strength of the reinforcing part 400 is Q1, the strength of the substrate 100 is Q2, and the strength of the explosion-proof valve 220 is Q3; 2*Q2≤Q1≤10*Q2; or, 2*Q3≤Q1≤10*Q3.

[0222] For example, Q1 can be 2*Q2, 3*Q2, 4*Q2, 5*Q2, 6*Q2, 7*Q2, 8*Q2, 9*Q2 or 10*Q2.

[0223] For example, Q1 can be 2*Q3, 3*Q3, 4*Q3, 5*Q3, 6*Q3, 7*Q3, 8*Q3, 9*Q3 or 10*Q3.

[0224] If Q1 is too large, it will lead to higher molding difficulty and manufacturing costs for the reinforcing part 400, which is not conducive to mass production. If Q1 is too small, the reinforcing effect of the reinforcing part 400 will not be obvious, and the outer shell will still be at risk of deformation or tearing.

[0225] To avoid the above problems, in this embodiment, Q1 is designed as 2*Q2≤Q1≤10*Q2; or 2*Q3≤Q1≤10*Q3. This ensures that the reinforcing part 400 can significantly strengthen the body area 124 and the explosion-proof area 123, effectively preventing deformation or tearing of the outer shell, while also reducing the molding difficulty and manufacturing cost of the reinforcing part 400, which is conducive to mass production.

[0226] Figure 8 A top view schematic diagram of the first extension structure of the reinforcement section 400 is shown.

[0227] like Figure 8 In some embodiments, the reinforcing part 400 is arranged in a continuous ring around the explosion-proof area 123.

[0228] The reinforcing part 400 is arranged in a ring around the explosion-proof valve 220, which makes the reinforcing effect of the reinforcing part 400 more obvious and further ensures that the outer shell is not easily deformed or torn under the impact of high temperature gas.

[0229] Figure 8a A top view schematic diagram of the second extension structure of the reinforcement section 400 is shown.

[0230] like Figure 8a In some embodiments, the reinforcing part 400 is arranged in a segmented ring around the explosion-proof area 123.

[0231] When the reinforcement section 400 is segmented, in addition to ensuring that the outer shell is not easily deformed or torn under the impact of high-temperature gas, the material cost of the reinforcement section 400 can also be reduced, which is conducive to mass production.

[0232] Figure 8b A top view schematic diagram of the third extension structure of the reinforcement section 400 is shown. Figure 8c This shows a top view of the fourth extension structure of the reinforcement section 400. Figure 8d A top view schematic diagram of the fifth extension structure of the reinforcement section 400 is shown.

[0233] like Figure 8b , Figure 8c and Figure 8d In some embodiments, an explosion-proof valve 220 is provided in the explosion-proof area 123. The weak part 222 of the explosion-proof valve 220 is arranged in a segmented annular shape, and the reinforcing part 400 is arranged in a segmented annular shape. The location of the reinforcing part 400 corresponds to the location of the weak part 222.

[0234] For example, the circumferential outer contour of the weak part 222 can be a circle, an oblong shape, a rectangle, or a rounded rectangle, etc.

[0235] For example, the reinforcing part 400 can be formed with the weak part 222 into a C-shaped structure with a break region, such as Figure 8b .

[0236] For example, the reinforcing part 400 can be formed with the weak part 222 into a structure with two disconnected regions. In this case, the reinforcing part 400 is divided into two segments. The disconnected regions can be located at the straight edges of the explosion-proof valve 220, such as... Figure 8c Alternatively, the disconnection area can be located at the curved edge of the explosion-proof valve 220, such as... Figure 8d .

[0237] When the explosion-proof valve 220 opens to release pressure, the weak part 222 cracks, and the portion enclosed by the weak part 222 warps up, thereby opening the explosion-proof valve 220. During the cracking process of the weak part 222, the surrounding area is more prone to deformation. Therefore, in this embodiment, the reinforcing part 400 is correspondingly positioned to the weak part 222, that is, the reinforcing part 400 is placed in a location on the outer casing prone to deformation. This maximizes the reinforcing effect of the reinforcing part 400 while reducing material costs, preventing deformation or tearing of the body area 124 and the explosion-proof area 123, ensuring the smooth opening of the explosion-proof valve 220, and contributing to improved cell safety. Simultaneously, reducing the area where the reinforcing part 400 is located reduces the impact of the connection to the reinforcing part 400 (especially welding) on ​​the weak part 222 of the explosion-proof valve 220, reducing the risk of deformation of the weak part 222, and ensuring the normal opening and venting of the explosion-proof valve 220.

[0238] Figure 8e A top view schematic diagram of the sixth extension structure of the reinforcement section 400 is shown.

[0239] like Figure 8e In some embodiments, the reinforcing portion 400 includes a first sub-portion 410 and a second sub-portion 420, along the planar direction of the mounting surface 120 (e.g., Figure 8e (in the X and Y directions), the second sub-part 420 is located on the side of the first sub-part 410 away from the explosion-proof area 123.

[0240] For example, the first sub-part 410 can be arranged in a continuous ring or in a segmented ring.

[0241] For example, the second sub-part 420 can be arranged in a continuous ring or in a segmented ring, and the arrangement of the first sub-part 410 and the second sub-part 420 can be the same or different.

[0242] Simultaneously, a first sub-part 410 and a second sub-part 420 are provided. The first sub-part 410 can form a first ring of reinforcing structure around the explosion-proof area 123, while the second sub-part 420 can form a second ring of reinforcing structure around the explosion-proof area 123. The first sub-part 410 and the second sub-part 420 cooperate with each other to further enhance the reinforcing effect of the reinforcing part 400 and further ensure that the outer shell is not easily deformed or torn under the impact of high-temperature gas.

[0243] It should be noted that this embodiment is only an illustrative example. Multiple reinforcing structures may be provided on the side of the second sub-part 420 away from the first sub-part 410, which is not limited here.

[0244] Figure 9 A top view schematic diagram of the seventh extension structure of the reinforcement section 400 is shown.

[0245] like Figure 9 In some embodiments, the mounting surface 120 includes two surfaces along a second direction (e.g., Figure 9 The first edge 121 is set at intervals in the X direction, and two edges are set along the third direction (such as...). Figure 9 The second edge 122 is spaced apart in the Y direction; the minimum distance between the explosion-proof area 123 and the first edge 121 is L5, and the minimum distance between the explosion-proof area 123 and the second edge 122 is L6, where L5 > L6; the second direction and the third direction intersect and are both parallel to the mounting surface 120; the reinforcing part 400 is disposed between the explosion-proof area 123 and the second edge 122 and extends linearly along the second direction.

[0246] For example, along a third direction, the reinforcing part 400 may be provided only on one side of the explosion-proof valve 220, or it may be provided on both opposite sides of the explosion-proof valve 220.

[0247] Combination Figure 9 Taking the structure and orientation shown as an example, the substrate 100 is constructed as the top plate 620 of the housing 600. The first edge 121 of the mounting surface 120 is the short edge of the top plate 620, and the second edge 122 of the mounting surface 120 is the long edge of the top plate 620. Since the distance between the explosion-proof area 123 and the second edge 122 is small, and the distance between the explosion-proof area 123 and the first edge 121 is large, when the housing is heated (for example, during welding or when the bare cell is thermally runaway), both the main body area 124 and the explosion-proof area 123 are more susceptible to thermal effects and deformation than the area near the first edge 121.

[0248] Therefore, in this embodiment, a reinforcing part 400 is provided between the explosion-proof area 123 and the second edge 122, which can effectively prevent deformation of the main body area 124 and the explosion-proof area 123, and help improve the sealing and safety of the shell.

[0249] Meanwhile, the reinforcement section 400 is designed to extend linearly. While ensuring the effective range of the reinforcement section 400, the extension length of the reinforcement section 400 can be reduced, which helps to reduce the material cost of the reinforcement section 400 and facilitates mass production.

[0250] Figure 9a A top view schematic diagram of the eighth extension structure of the reinforcement section 400 is shown.

[0251] like Figure 9a In some embodiments, along the second direction, the two ends of the reinforcement 400 are respectively close to their respective adjacent first edges 121.

[0252] In this embodiment, the reinforcing part 400 can cover the entire area of ​​the top plate 620 along the second direction. On the one hand, it can further enhance the reinforcing effect on the top plate 620, more effectively prevent deformation of the body area 124 and the explosion-proof area 123, and further improve the sealing and safety of the shell. On the other hand, when the reinforcing part 400 protrudes into the accommodating space 500, the bare battery cell can be reliably limited by the reinforcing part 400, eliminating the need to provide an insulating gasket for limiting the bare battery cell on the inner side of the top plate 620, which helps to reduce the manufacturing cost of the battery cell.

[0253] In light of the foregoing, it should be noted that insulation between the bare battery cell and the reinforcing section 400, the main body region 124, and the explosion-proof region 123 can be achieved through a base plate at the bottom of the bare battery cell and an insulating film (i.e., Mylar) covering the bare battery cell. There is no need to install additional insulating structures between the reinforcing section 400 and the bare battery cell, or between the explosion-proof valve 220 and the bare battery cell.

[0254] Figure 10 Showing Figure 4 An enlarged schematic diagram of the eleventh structure in Part B.

[0255] like Figure 10 In some embodiments, the reinforcing portion 400 is integrally formed with the body region 124 and the explosion-proof region 123, and the reinforcing portion 400 is stamped at the connection between the body region 124 and the explosion-proof region 123. The reinforcing portion 400 has a reinforcing protrusion 471 that is away from the mounting surface 120.

[0256] For example, in this embodiment, the reinforcing protrusion 471 may be located on the outer or inner side of the substrate 100.

[0257] For example, in this embodiment, when multiple reinforcing portions 400 are provided, the reinforcing protrusions 471 of some reinforcing portions 400 may be located on the inner side of the substrate 100, and the reinforcing protrusions 471 of the other reinforcing portion 400 may be located on the outer side of the substrate 100.

[0258] In addition to the aforementioned beneficial effects of integrally forming the reinforcing portion 400 with the main body region 124 or the explosion-proof region 123, forming the reinforcing portion 400 by stamping the connection between the main body region 124 and the explosion-proof region 123 can reduce the manufacturing difficulty and material cost of the reinforcing portion 400 and simplify the assembly process of the casing. Simultaneously, a stamping groove is formed at the location of the reinforcing portion 400 after stamping. When there is stress in the main body region 124 or the explosion-proof region 123 (e.g., after welding), the stamping groove can be used to release stress, thereby reducing the risk of deformation in the main body region 124 and the explosion-proof region 123, especially in the weak point 222.

[0259] like Figure 10 In some embodiments, along the first direction, the reinforced protrusion 471 is located on the side of the substrate 100 near the receiving space 500, and the explosion-proof valve 220 protrudes.

[0260] by Figure 10 Taking the direction and structure shown as an example, the reinforcing protrusion 471 is located below the substrate 100. When the bare cell in the accommodating space 500 expands upward due to thermal runaway, moves upward due to vibration, or moves upward due to compression, it will first contact the reinforcing part 400. Under the limiting effect of the reinforcing part 400, the bare cell can be prevented from contacting the explosion-proof valve 220, which can effectively prevent the bare cell from short-circuiting to the shell.

[0261] Meanwhile, when thermal runaway occurs in the bare battery cell, the limiting effect of the reinforcing part 400 on the bare battery cell can also prevent the expanded bare battery cell from blocking the gas flow channel leading to the explosion-proof valve 220 in the housing space 500, ensuring that the gas can be discharged from the casing in a timely and smooth manner through the opened explosion-proof valve 220.

[0262] Figure 11 Showing Figure 4 An enlarged schematic diagram of the twelfth structure in Part B. Figure 12 Showing Figure 11 A partial explosion diagram of the corresponding outer shell.

[0263] like Figure 11 and Figure 12 In some embodiments, the reinforcing part 400 includes a plate-shaped third reinforcing body 450; the third reinforcing body 450 is connected to the connection portion of the body region 124 and the explosion-proof region 123, the edge of the third reinforcing body 450 is close to the edge of the mounting surface 120, and the third reinforcing body 450 is formed with a clearance through hole 451 extending along a first direction, the clearance through hole 451 corresponding to the explosion-proof region 123.

[0264] For example, the third reinforcing body 450 can be a sheet-like structure or a structural component formed from a sheet-like structure.

[0265] In this embodiment, the reinforcing part 400 can cover a large portion of the mounting surface 120, which can significantly strengthen the substrate 100 and greatly reduce the risk of deformation and tearing in the body area 124 and the explosion-proof area 123, thus helping to improve the safety and sealing of the casing.

[0266] Meanwhile, since the contact area between the third reinforcing body 450 and the mounting surface 120 in this embodiment is large, the connection method between the two can be more flexible, and it is easier to form a reliable connection structure between the two.

[0267] like Figure 11 In some embodiments, the reinforcing portion 400 has a reinforcing protrusion 471 formed by stamping a third reinforcing body 450.

[0268] By stamping the third reinforcing body 450 to form the reinforcing protrusion 471, the structural strength of the third reinforcing body 450 can be enhanced. This allows the third reinforcing body 450 to provide greater reinforcement to the body region 124 and the explosion-proof region 123, further preventing deformation or tearing of the body region 124 and the explosion-proof region 123. Simultaneously, it can reduce the material cost and molding difficulty of the reinforcing part 400, facilitating mass production.

[0269] like Figure 11 In some embodiments, the reinforced protrusion 471 is provided along the edge of the clearance through hole 451.

[0270] As described above, the pressure relief location of the explosion-proof zone 123 is typically located in the center of the zone, a position more prone to deformation. For the third reinforcing body 450, the edge of the clearance hole 451 is closest to the center of the explosion-proof zone 123, and the structural strength of the part of the third reinforcing body 450 near the reinforcing protrusion 471 is greater. Therefore, aligning the reinforcing protrusion 471 along the edge of the clearance hole 451 provides greater reinforcement to the deformation-prone areas of the explosion-proof zone 123.

[0271] Meanwhile, when the reinforcing protrusion 471 is formed by stamping, the third reinforcing body 450 at the corresponding position of the reinforcing protrusion 471 separates from the mounting surface 120. This can prevent the setting of the third reinforcing body 450 from having an adverse effect on the pressure relief position of the explosion-proof area 123. This helps to ensure that the pressure relief position of the explosion-proof area 123 can be opened smoothly when the bare cell experiences thermal runaway, which helps to improve the safety of the cell including the casing of this embodiment.

[0272] Furthermore, when the reinforcing protrusion 471 is formed by stamping and is disposed along the edge of the clearance hole 451, a continuous, large surface can be formed on the third reinforcing body 450, and this surface connects to the mounting surface 120, which helps to improve the connection reliability between the third reinforcing body 450 and the substrate 100. It also reduces the risk of deformation in the area of ​​the third reinforcing body 450 adjacent to the reinforcing protrusion 471 due to the stamping process, ensuring that the aforementioned area forms a relatively flat surface, which is beneficial for connection with the mounting surface 120.

[0273] like Figure 11 In some embodiments, the material thickness of the third reinforcing body 450 is t2, where 0.25mm≤t2≤3mm.

[0274] For example, t2 can be 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.5mm, 2mm, 2.5mm or 3mm.

[0275] If t2 is too small, the third reinforcing body 450 may be welded through when the welding reinforcement part 400 is formed, which may lead to the risk of cracking and leakage. If t2 is too large, it will not only increase the overall weight and manufacturing cost of the cell, but also cause the reinforcement part 400 to occupy too much space 500, which will reduce the energy density of the cell.

[0276] To avoid the above problems, this embodiment designs t2 to be 0.25mm≤t2≤3mm. This can reduce the risk of cracking and leakage in the welded part 300, and also avoid the reinforcing part 400 occupying too much space in the accommodating space 500. This helps to ensure the energy density of the battery cell, and also helps to reduce the overall weight and manufacturing cost of the battery cell.

[0277] like Figure 3 and Figure 5 In some embodiments, a through mounting hole 110 is formed in the explosion-proof area 123, and at least a portion of the explosion-proof valve 220 is placed in the mounting hole 110; the minimum distance between the edge of the mounting hole 110 and the edge of the mounting surface 120 is L7, 2mm≤L7≤10mm.

[0278] For example, L7 can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm.

[0279] If L7 is too small, deformation may occur at the edge of the mounting hole 110 during stamping, affecting the welding quality of the body region 124 and the explosion-proof valve 220. Simultaneously, stress concentration may occur during welding of the body region 124 and the explosion-proof valve 220, also affecting the welding quality. Furthermore, the strength at the edge of the mounting hole 110 will decrease, and excessive shear force may cause tearing of the body region 124 opposite the weak part 222 when the weak part 222 fractures under pressure. If L7 is too large, the explosion-proof valve 220 will be too small, hindering the timely discharge of high-temperature gases inside the battery cell in the event of thermal runaway.

[0280] To avoid the above problems, in this embodiment, L7 is designed to be 2mm≤L7≤10mm. This ensures that the explosion-proof valve 220 has sufficient installation space, allowing the high-temperature gas inside the battery cell to be discharged in a timely manner after the explosion-proof valve 220 is opened. It also ensures the strength of the area of ​​the body region 124 near the mounting hole 110, guarantees the welding quality of the body region 124 and the explosion-proof valve 220, reduces the risk of tearing in the body region 124, and helps to improve the safety of the battery cell.

[0281] Figure 13 Showing Figure 4 An enlarged schematic diagram of the thirteenth structure in section B before welding.

[0282] like Figure 13 In some embodiments, the explosion-proof area 123 is formed with a through mounting hole 110, and the explosion-proof valve 220 is at least partially disposed in the mounting hole 110; the reinforcing part 400 includes a main body sub-part 470 and a transition sub-part 460 connected to each other, the main body sub-part 470 is disposed on the mounting surface 120, and the transition sub-part 460 is located between the edge of the mounting hole 110 and the edge of the explosion-proof valve 220 along the planar direction of the mounting surface 120, and the main body sub-part 470 is connected to the main body area 124 and / or the explosion-proof valve 220 respectively through the transition sub-part 460.

[0283] By connecting the transition sub-section 460 to the main body region 124 or the explosion-proof valve 220, the main body sub-section 470 connected to the transition sub-section 460 thickens the structure at its location, thereby strengthening the structure of the explosion-proof valve 220 or the area nearby.

[0284] When the battery cell, including the casing of this embodiment, experiences thermal runaway, the high-temperature gas generated inside the casing 600 will concentrate on the explosion-proof valve 220 located in the explosion-proof area 123. Because the main body sub-section 470 is located near the explosion-proof valve 220, when the explosion-proof valve 220 is pressurized, the reinforcing effect of the main body sub-section 470 prevents deformation and tearing in the area near the explosion-proof valve 220, thus improving the sealing and safety of the casing and effectively preventing liquid or gas leakage during use.

[0285] Meanwhile, since the transition sub-part 460 can fill the gap between the edge of the mounting hole 110 and the edge of the explosion-proof valve 220, even if the gap between the two is large, it will not affect the connection between the body area 124 and the explosion-proof valve 220. This can reduce the dimensional accuracy requirements of the mounting hole 110 and the explosion-proof valve 220, which helps to reduce the manufacturing difficulty of the housing and improve the yield.

[0286] Figure 13a Showing Figure 4 An enlarged schematic diagram of the thirteenth structure in section B after welding using the first welding method.

[0287] like Figure 13 and Figure 13a In some embodiments, the explosion-proof valve 220, the body region 124, and the reinforcement 400 are independent of each other; the edge of the explosion-proof valve 220 and the edge of the mounting hole 110 are welded to the transition sub-part 460, and a welded part 300 is formed along the width direction of the reinforcement 400.

[0288] like Figure 13a When welding the transition sub-part 460, the edge of the explosion-proof valve 220 and the edge of the mounting hole 110, the width of the transition sub-part 460 can be reduced or the weld width of the weld 300 can be increased so that the transition sub-part 460 can form a molten pool 310 in one welding, so that the body area 124, the reinforcing part 400 and the explosion-proof valve 220 can be interconnected in one welding.

[0289] The explosion-proof valve 220, the body region 124, and the reinforcing part 400 are welded together as a whole through the transition sub-part 460 of the reinforcing part 400. This is equivalent to increasing the thickness of the body region 124 near the weld joint 300 and also increasing the thickness of the explosion-proof region 123 near the weld joint 300 through the main body part 420 of the reinforcing part 400. On the one hand, this improves the welding quality between the body region 124 and the explosion-proof valve 220; on the other hand, it combines... Figure 13aIt can be seen that although the welded part 300 is the connection between the explosion-proof area 123 and the main body area 124, the main body part 420 located at this position is an integrally formed structure. Since the integrally formed main body part 420 itself has greater strength, it can improve the strength of the welded part 300 at the corresponding position.

[0290] Figure 13b Showing Figure 4 An enlarged schematic diagram of the thirteenth structure in section B after welding using the second welding method.

[0291] like Figure 13b In some embodiments, the edges of the explosion-proof valve 220 and the mounting hole 110 are welded to the transition sub-part 460, and at least two welded portions 300 are formed along the width direction of the reinforcing part 400.

[0292] When the width of the transition sub-part 460 is large, the edges of the transition sub-part 460 and the mounting hole 110 can be welded to form a first welded part 300a, and the edges of the transition sub-part 460 and the explosion-proof valve 220 can be welded to form a second welded part 300b. In this case, two welding operations are required to connect the body area 124, the explosion-proof valve 220, and the reinforcing part 400.

[0293] The welding method of this embodiment can meet the welding requirements by forming a welded part 300 with a small weld width, thus reducing the energy consumption of a single welding operation and helping to reduce the assembly cost of the outer casing.

[0294] Figure 13c Showing Figure 4 An enlarged schematic diagram of the fourteenth structure in section B after welding using the first welding method.

[0295] like Figure 13c When the reinforcing protrusion 471 is located on the outer side of the substrate 100, the body region 124, the reinforcing part 400, and the explosion-proof valve 220 can be interconnected by a single welding process. The beneficial effects are similar to those achieved when the reinforcing protrusion 471 is located on the inner side of the substrate 100, and the body region 124, the reinforcing part 400, and the explosion-proof valve 220 can be interconnected by a single welding process. Therefore, the details will not be repeated here.

[0296] Figure 13d Showing Figure 4 An enlarged schematic diagram of the fourteenth structure in section B after welding using the second welding method.

[0297] like Figure 13dWhen the reinforcing protrusion 471 is located on the outer side of the substrate 100, the body region 124, the reinforcing part 400, and the explosion-proof valve 220 can be interconnected by secondary welding. The beneficial effect is similar to that achieved by interconnecting the body region 124, the reinforcing part 400, and the explosion-proof valve 220 by secondary welding when the reinforcing protrusion 471 is located on the inner side of the substrate 100, and will not be repeated here.

[0298] like Figure 13 In some embodiments, the width of the transition sub-part 460 is L8, where 0.1mm ≤ L8 ≤ 5mm.

[0299] For example, the transition sub-part 460 has a transition protrusion 461 away from the main sub-part 470 and a root end 462 close to the main sub-part 470. The width of the transition protrusion 461 can be the same as the width of the root end 462. In this case, the cross-sectional shape of the transition sub-part 460 perpendicular to the extension direction is rectangular.

[0300] For example, L8 can be 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm.

[0301] If L8 is too small, the transition section 460 will have difficulty effectively filling the gap between the edge of the mounting hole 110 and the edge of the explosion-proof valve 220, and the welding quality of the fusion section 300 cannot be guaranteed. Simultaneously, if L5 is too small, the transition section 460 will have low strength, potentially causing it to bend during alignment of the body region 124, the explosion-proof valve 220, and the transition section 460, also affecting the welding quality of the fusion section 300. If L8 is too large, interference may occur between the transition section 460, the body region 124, and the explosion-proof valve 220, making welding impossible.

[0302] To avoid the above problems, in this embodiment, L8 is designed to be 0.1mm≤L8≤5mm. This can avoid interference between the transition sub-part 460, the main body region 124 and the explosion-proof valve 220, and also ensure the welding quality of the welded part 300 formed by the three, reducing the risk of cracking and leakage in the welded part 300.

[0303] Figure 13e Showing Figure 4 An enlarged schematic diagram of the fifteenth structure in Part B before welding.

[0304] like Figure 13eIn some embodiments, the transition sub-part 460 has a transition protrusion 461 that is away from the main sub-part 470 and a root end 462 that is close to the main sub-part 470. The width of the transition protrusion 461 is smaller than the width of the root end 462, and the width of the transition protrusion 461 is L9, 0.2mm≤L9≤0.5mm.

[0305] For example, L9 can be 0.2mm, 0.3mm, 0.4mm or 0.5mm.

[0306] For example, in this embodiment, the cross-sectional shape of the transition sub-part 460 perpendicular to the extension direction is trapezoidal.

[0307] The width of the transition protrusion 461 is designed to be small, so that the entire transition protrusion 461 can form a molten pool 310 in one welding, so that the body area 124, the reinforcing part 400 and the explosion-proof valve 220 can be interconnected in one welding.

[0308] If L9 is too small, melting the transition sub-part 460 will not be sufficient to reliably connect the edge of the spaced body region 124 and the edge of the explosion-proof valve 220. If L9 is too large, it may cause interference between the transition sub-part 460, the body region 124 and the explosion-proof valve 220, making welding impossible. It may also prevent the transition protrusion 461 from being completely melted by a single welding operation, thus preventing the edge of the body region 124 and the edge of the explosion-proof valve 220 from being connected.

[0309] To avoid the above problems, in this embodiment, L9 is designed to be 0.2mm≤L9≤0.5mm. This can avoid interference between the transition sub-section 460, the main body region 124 and the explosion-proof valve 220, and also ensure the welding quality of the fusion section 300, reducing the risk of rupture and leakage in the fusion section 300. A reliable connection between the main body region 124 and the explosion-proof valve 220 can be formed by a single welding, which helps to simplify the welding process and improve the efficiency of cell manufacturing.

[0310] Figure 14 A partial cross-sectional diagram showing another structure of the reinforcement 400 is shown.

[0311] like Figure 13 and Figure 14 In some embodiments, a groove 480 is provided on the surface of the main body sub-part 470 near the mounting surface 120. The groove 480 passes through the side wall of the main body sub-part 470 radially along the mounting hole 110. The groove 480 and the mounting surface 120 enclose each other to form an exhaust channel 700.

[0312] For example, the radial cross-sectional shape of the groove 480 can be semi-circular, rectangular, triangular or arc-shaped.

[0313] For example, the transition sub-section 460 is segmented along the edge of the mounting hole 110, and the groove 480 may be provided between two adjacent transition sub-sections 460.

[0314] For example, the groove 480 may also extend through the root end 462 of the transition sub-section 460.

[0315] When thermal runaway occurs in the battery cell, the high-temperature air in the middle of the containment space 500 can flow directly to the opened explosion-proof valve 220. Meanwhile, the high-temperature gas near the inner wall of the housing 600 can flow through the exhaust channel 700 and the reinforcing part 400 to the explosion-proof valve 220. This prevents the main body sub-part 470 of the reinforcing part 400 from obstructing the flow of high-temperature gas, thus helping to quickly expel the high-temperature gas from the containment space 500 into the battery cell and improving the safety of the battery cell.

[0316] like Figure 13 In some embodiments, the minimum distance (hereinafter referred to as top height difference) between any two of the three surfaces of the substrate 100 away from the mounting surface 120, the surface of the transition sub-part 460 away from the main body sub-part 470, and the surface of the explosion-proof valve 220 away from the explosion-proof protrusion 221 along the first direction is 0 mm to 1 mm.

[0317] For example, when the thickness of the substrate 100 is less than 1 mm, the height difference at the top is not greater than the thickness of the substrate 100.

[0318] For example, the top height difference can be 0mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm.

[0319] If the height difference at the top is too large, it will affect the appearance of the battery cell on the one hand, and it will also have an adverse effect on the uniformity of the welded part 300 on the other hand. It may cause cracks in the welded part 300, resulting in lower welding strength and durability of the welded part 300 and affecting the welding quality.

[0320] To avoid the above problems, this embodiment limits the top height difference to 0mm to 1mm, which can ensure that the appearance of the battery cell is more aesthetically pleasing, as well as the welding quality, welding strength and durability of the fusion section 300, and avoid tearing of the fusion section 300, which helps to improve the safety and sealing of the battery cell.

[0321] like Figure 1 , Figure 2 and Figure 5In some embodiments, the housing includes a housing 600 and a cover body 210. The housing 600 is formed by stamping or splicing and has at least one open end 640. The cover body 210 covers the open end 640. The substrate 100 is configured as at least one of the cover body 210 and the housing 600.

[0322] Based on the foregoing, for the shell of the first structure, the bottom plate 630 and four side plates 610 of the shell 600 can be formed by stamping; or, a rectangular plate can be bent along its length and spliced ​​end to end to form four side plates 610, with the splice located on one of the side plates 610, and then the bottom plate 630 can be connected to the four side plates 610 to form the shell 600.

[0323] For the second type of shell structure, the top plate 620, bottom plate 630 and two side plates 610 of the shell 600 can be formed by stamping along the axis of the cylindrical structure; or, the top plate 620, bottom plate 630 and two side plates 610 can be formed by bending the rectangular plate along the length direction and splicing them end to end, with the splicing point located at the bottom plate 630 or the top plate 620.

[0324] It should be noted that when the substrate 100 is configured as a housing 600, it can be configured as the side plate 610 or bottom plate 630 of the housing with the first structure; or it can be configured as the side plate 610, top plate 620 or bottom plate 630 of the housing with the second structure.

[0325] For example, when the housing 600 is formed by splicing, the mounting surface 120 of the substrate 100 can be positioned opposite to the splicing point.

[0326] Based on the same inventive concept and in conjunction with the description of the casings of the above embodiments, this embodiment provides a battery cell that has the corresponding technical effects of the casings of the above embodiments, which will not be repeated here.

[0327] A battery cell includes a housing as described in the various embodiments above.

[0328] It should be noted that some embodiments of this application have been described above. Other embodiments are within the scope of the appended claims.

[0329] 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.

[0330] 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.

[0331] 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 (including the claims) is limited to these examples; within the framework 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 the details for the sake of brevity.

[0332] 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.

[0333] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. 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 casing, characterized in that, include: The substrate has a mounting surface, wherein the mounting surface is provided with an explosion-proof area and a body area connected together, and the explosion-proof area is used to install an explosion-proof valve; The reinforcing part is connected to the mounting surface and at least partially covers the connection between the explosion-proof area and the body area.

2. The outer casing according to claim 1, characterized in that, A through mounting hole is formed within the explosion-proof area. The explosion-proof valve is independent of the body area, and at least a portion of the explosion-proof valve is placed within the mounting hole. The reinforcing part is provided at least in a portion of the area along the edge of the explosion-proof valve, and the reinforcing part covers the edge of the explosion-proof valve and the edge of the mounting hole radially along the mounting hole.

3. The outer casing according to claim 1, characterized in that, An accommodating space is formed within the housing, with the inner side of the substrate close to the accommodating space and the outer side of the substrate away from the accommodating space; the reinforcing portion is independent of at least one of the body region and the explosion-proof region, and along a first direction, the reinforcing portion has a reinforcing protrusion away from the mounting surface, the reinforcing protrusion being located on the inner side and / or outer side of the substrate; the first direction is the thickness direction of the substrate.

4. The outer casing according to claim 3, characterized in that, The explosion-proof valve is provided within the explosion-proof area. Along the first direction, the explosion-proof valve has an explosion-proof protrusion away from the mounting surface. The explosion-proof protrusion is located on the inner or outer side of the substrate.

5. The outer casing according to claim 4, characterized in that, Along the first direction, the reinforcing protrusion and the explosion-proof protrusion are located on the same side of the substrate.

6. The outer casing according to claim 5, characterized in that, Both the reinforcing protrusion and the explosion-proof protrusion are located on the inner side of the substrate.

7. The outer casing according to claim 4, characterized in that, Along the first direction, the distance between the reinforcing protrusion and the explosion-proof protrusion is H1, 0mm ≤ H1 ≤ 10mm; and / or, Along the first direction, the distance between the explosion-proof protrusion and the adjacent surface of the body area is H2, the material thickness of the explosion-proof valve is t1, 2*t1≤H2≤10*t1; and / or, The explosion-proof valve is provided with a weak part, the thickness of which is less than the thickness of the rest of the explosion-proof valve excluding the weak part; the minimum interval between the weak part and the reinforcing part along the plane of the mounting surface is L10, where 0.5mm≤L10≤20mm.

8. The outer casing according to claim 1, characterized in that, The explosion-proof valve is installed in the explosion-proof area; The reinforcing section, the main body area, and the explosion-proof area are independent of each other and fixedly connected; or, The reinforcing part is integrally formed and connected to the body area or the explosion-proof area; or... The main body area and the explosion-proof area are integrally formed and connected; the reinforcing part is independent of the main body area and the explosion-proof area, and the reinforcing part is connected to the main body area and the explosion-proof area; or... The main body area is integrally formed and connected to a first reinforcing body, and the explosion-proof area is integrally formed and connected to a second reinforcing body. The first reinforcing body and the second reinforcing body are assembled to form the reinforcing part.

9. The outer casing according to claim 1, characterized in that, At least a portion of the edge of the surface of the reinforcing part near the mounting surface is formed with a first chamfer; and / or, At least a portion of the edge of the surface of the reinforcing part away from the mounting surface is formed with a second chamfer; and / or, The explosion-proof valve has an explosion-proof protrusion away from the mounting surface, and at least a portion of the circumferential edge of the explosion-proof protrusion has a third chamfer; and / or, The explosion-proof valve has an explosion-proof protruding end away from the mounting surface, and the surface of the explosion-proof valve that is disposed opposite to the explosion-proof protruding end in a first direction is an explosion-proof concave surface, and at least a portion of the edges of the explosion-proof concave surface are formed with a fourth chamfer.

10. The outer casing according to claim 9, characterized in that, At least one of the first chamfer, the second chamfer, the third chamfer, and the fourth chamfer includes a rounded corner, and the radius of the rounded corner is R, 0.05mm≤R≤5mm.

11. The outer casing according to claim 1, characterized in that, The thickness of the substrate is t, where 0.1 mm ≤ t ≤ 0.5 mm; and / or, The explosion-proof valve has a material thickness of t1, where 0.1mm ≤ t1 ≤ 0.5mm; and / or, The absolute value of the difference between the thickness of the substrate and the material thickness of the explosion-proof valve is no greater than 0.2 mm.

12. The outer casing according to claim 1, characterized in that, The explosion-proof valve is provided within the explosion-proof area, and the reinforcing part is welded to at least one of the body area and the explosion-proof area to form a welded part extending around the explosion-proof area.

13. The outer casing according to claim 12, characterized in that, When the reinforcing portion is located on the outer side of the substrate, a positioning groove is formed on the surface of the reinforcing portion away from the mounting surface, and the welding portion is disposed along the positioning groove and covers the positioning groove; and / or, The thickness of the substrate is t, and the weld depth along the first direction is H3, where 0.8*t ≤ H3 ≤ 5*t; and / or, The weld width direction intersects the extension direction of the weld, and the weld width of the weld is L1, where 1*t≤L1≤5*t; and / or, Along the weld width direction of the welded portion, the minimum gap between the edge of the welded portion and the edge of the adjacent reinforcing portion is L2, 0mm≤L2≤2mm; and / or, The explosion-proof valve is provided with a weak portion, the thickness of which is less than the thickness of the rest of the explosion-proof valve excluding the weak portion; the minimum distance between the weak portion and the welded portion along the plane of the mounting surface is L3, 0.5mm≤L3≤20mm; and / or, The welded portion includes a weld pool, and the outer contour of the cross-section of the weld pool along the weld width direction is U-shaped.

14. The outer casing according to claim 1, characterized in that, The height H4 of the reinforcing part along the first direction is 0.5mm ≤ H4 ≤ 3mm; and / or, The width direction of the reinforcing part intersects the extension direction of the reinforcing part, and the reinforcing part includes a main body sub-part disposed on the mounting surface, the width of the main body sub-part being L4, 1mm≤L4≤5mm; and / or, The hardness of the reinforcing portion is greater than the hardness of the substrate, and the hardness of the reinforcing portion is greater than the hardness of the explosion-proof valve; and / or, The strength of the reinforcing part is Q1, the strength of the substrate is Q2, and the strength of the explosion-proof valve is Q3; 2*Q2≤Q1≤10*Q2; or, 2*Q3≤Q1≤10*Q3.

15. The outer casing according to claim 1, characterized in that, The reinforcing part is arranged in a continuous ring or in a segmented ring around the explosion-proof area.

16. The outer casing according to claim 15, characterized in that, The explosion-proof valve is provided within the explosion-proof area. The explosion-proof valve has a weak part, and the thickness of the weak part is less than the thickness of the part of the explosion-proof valve excluding the weak part. The weak part is arranged in a segmented ring, the reinforcing part is arranged in a segmented ring, and the position of the reinforcing part corresponds to the position of the weak part.

17. The outer casing according to claim 1, characterized in that, The mounting surface includes two first edges spaced apart along a second direction, and two second edges spaced apart along a third direction; the minimum distance between the explosion-proof area and the first edge is L5, and the minimum distance between the explosion-proof area and the second edge is L6, where L5 > L6; the second direction and the third direction intersect and are both parallel to the mounting surface; The reinforcing part is disposed between the explosion-proof area and the second edge, and extends linearly along the second direction.

18. The outer casing according to claim 17, characterized in that, Along the second direction, the two ends of the reinforcing portion are respectively close to their respective adjacent first edges.

19. The outer casing according to claim 1, characterized in that, The reinforcing part includes a first sub-part and a second sub-part. Along the plane direction of the mounting surface, the second sub-part is located on the side of the first sub-part away from the explosion-proof area.

20. The outer casing according to claim 1, characterized in that, The reinforcing part is integrally formed with the body area and the explosion-proof area, and the reinforcing part is formed by stamping at the connection between the body area and the explosion-proof area. The reinforcing part has a reinforcing protrusion that is away from the mounting surface.

21. The outer casing according to claim 20, characterized in that, An accommodating space is formed within the housing, and the explosion-proof valve is disposed within the explosion-proof area; along the first direction, the reinforcing protrusion is located on the side of the substrate near the accommodating space and protrudes from the explosion-proof valve.

22. The outer casing according to claim 1, characterized in that, The reinforcing part includes a plate-shaped third reinforcing body; the third reinforcing body is connected to the connection portion of the body area and the explosion-proof area, the edge of the third reinforcing body is close to the edge of the mounting surface, and the third reinforcing body has a through hole extending along a first direction, the through hole corresponding to the explosion-proof area.

23. The outer casing according to claim 22, characterized in that, The reinforcing portion has a reinforcing protrusion formed by stamping the third reinforcing body; and / or The reinforcing portion includes a reinforcing protrusion, which is disposed along the edge of the clearance through hole; and / or, The material thickness of the third reinforcing body is t2, where 0.25mm ≤ t2 ≤ 3mm.

24. The outer casing according to claim 1, characterized in that, A through mounting hole is formed within the explosion-proof area, at least a portion of the explosion-proof valve is placed within the mounting hole, and the minimum distance between the edge of the mounting hole and the edge of the mounting surface is L7, where 2mm≤L7≤10mm.

25. The outer casing according to claim 1, characterized in that, The explosion-proof area has a through mounting hole, and the explosion-proof valve is at least partially disposed in the mounting hole; the reinforcing part includes a main body sub-part and a transition sub-part connected to each other, the main body sub-part is disposed on the mounting surface, and the transition sub-part is located between the edge of the mounting hole and the edge of the explosion-proof valve along the plane direction of the mounting surface, and the main body sub-part is connected to the main body area and / or the explosion-proof valve respectively through the transition sub-part.

26. The outer casing according to claim 25, characterized in that, The explosion-proof valve, the body area, and the reinforcing part are independent of each other; the edge of the explosion-proof valve and the edge of the mounting hole are both welded to the transition sub-part, and at least one welded part is formed along the width direction of the reinforcing part.

27. The outer casing according to claim 25, characterized in that, The width of the transition sub-section is L8, where 0.1mm ≤ L8 ≤ 5mm; and / or, The transition sub-part has a transition protrusion end away from the main sub-part and a root end close to the main sub-part. The width of the transition protrusion end is smaller than the width of the root end, and the width of the transition protrusion end is L9, where 0.2mm≤L9≤0.5mm.

28. The outer casing according to claim 25, characterized in that, The surface of the main body sub-part near the mounting surface is provided with a groove, which extends radially through the side wall of the main body sub-part along the mounting hole; the groove and the mounting surface together form an exhaust channel.

29. The outer casing according to any one of claims 1 to 28, characterized in that, The outer casing includes a shell and a cover plate body. The shell is formed by stamping or splicing, and the shell has at least one open end. The cover plate body covers the open end. The substrate is constructed as at least one of the cover plate body and the housing.

30. A battery cell, characterized in that, Includes the housing as described in any one of claims 1 to 29.

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