Shell and battery cell

Abstract

The utility model provides a shell and a battery cell, and the shell comprises a substrate which is provided with a mounting surface arranged along a first direction, and the mounting surface is provided with a through mounting hole; at least part of the anti-explosion valve is arranged in the mounting hole; the reinforcing part comprises a main body sub-part and a transition sub-part which are connected with each other, the main body sub-part is arranged on the mounting surface, the transition sub-part is located between the edge of the mounting hole and the edge of the anti-explosion valve in the second direction, and the main body sub-part is connected with the base plate and / or the anti-explosion valve through the transition sub-part. According to the shell and the battery cell provided by the invention, the transition sub-part is connected with the substrate or the anti-explosion valve, so that the main body sub-part connected with the transition sub-part thickens the structure of the position where the main body sub-part is located, the structure of the anti-explosion valve or the area near the anti-explosion valve can be reinforced, the area near the anti-explosion valve is not easy to deform and tear, and the anti-explosion performance of the battery cell is improved. The sealing performance and the safety of the shell can be improved, and the phenomenon of liquid leakage or gas leakage of the shell in the using process can be effectively prevented.

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] The battery cell's outer casing includes a housing and a cover assembly. The cover assembly fits over the open end of the housing, forming a space to accommodate the bare battery cell. In related technologies, the cover body of the cover assembly is welded to the housing. Both the housing and the cover body are made of aluminum alloy, which is not only thick and has low strength but also poor high-temperature resistance, making it difficult to withstand high pressure. When the battery cell experiences thermal runaway, the housing and cover body are prone to burn-through, resulting in a significant risk of thermal diffusion from the battery cell. Furthermore, the thick housing and cover body occupy excessive space, leading to a lower energy density of the battery cell.

[0003] The applicant discovered that if steel is used to manufacture the casing and cover body, the thickness of the casing and cover body 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.

[0004] However, taking the explosion-proof valve installed in the housing as an example, if the housing is designed to be thin, if the battery cell experiences thermal runaway, there may be a risk of deformation, tearing and leakage in the area of ​​the housing near the explosion-proof valve. Utility Model Content

[0005] In view of this, the purpose of this application is to provide a casing and a battery cell to solve some or all of the aforementioned technical problems.

[0006] To achieve the above objectives, a first aspect of this application provides a housing comprising: a substrate having a mounting surface disposed along a first direction, the mounting surface having a through mounting hole; an explosion-proof valve at least partially disposed within the mounting hole; and a reinforcing portion comprising a main body sub-part and a transition sub-part connected to each other, the main body sub-part being disposed on the mounting surface, the transition sub-part being located along a second direction between the edge of the mounting hole and the edge of the explosion-proof valve, the main body sub-part being connected to the substrate and / or the explosion-proof valve respectively via the transition sub-part; the first direction being the thickness direction of the substrate, and the second direction being the planar direction of the mounting surface.

[0007] Optionally, the reinforcing part is arranged in a continuous annular pattern or in a segmented annular pattern around the explosion-proof valve.

[0008] Optionally, the reinforcing part is provided in at least one ring along the radial direction of the explosion-proof valve.

[0009] Optionally, along the first direction, the main body sub-part has a reinforcing protrusion away from the mounting surface, and the explosion-proof valve has an explosion-proof protrusion away from the mounting surface. The distance H1 between the reinforcing protrusion and the explosion-proof protrusion is 0 mm to 3 mm.

[0010] Optionally, the transition sub-part is integrally formed and connected to the substrate or the explosion-proof valve; or, the transition sub-part is welded to the substrate or the explosion-proof valve.

[0011] Optionally, the explosion-proof valve, the base plate, and the reinforcing part are independent of each other; the edge of the explosion-proof valve and the edge of the mounting hole are respectively welded to the transition part to form at least one welded part.

[0012] Optionally, the thickness H2 of the substrate is t, where t is from 0.15 mm to 0.3 mm; the weld depth H3 of the welded portion along the first direction is from 2 t to 5 t, and / or; the welded portion extends along the edge of the mounting hole, and the radial dimension of the welded portion along the mounting hole is defined as the weld width of the welded portion, where the weld width L1 is from 1 t to 5 t; and / or, the minimum distance L2 between the edge of the mounting hole and the edge of the substrate is from 0.5 mm to 10 mm; and / or, the dimension of the reinforcing portion along the weld width direction is defined as the width, and the minimum distance L3 between the edge of the welded portion along the weld width direction and the edge of the reinforcing portion along the width direction is from 0.1 mm to 2 mm; and / or, the width L4 of the main body sub-part is from 1 mm to 5 mm; and / or, the width L5 of the transition sub-part is from 0.1 mm to 5 mm; and / or The transition sub-part has a transition protrusion distant from the main sub-part and a root end close to the main sub-part. The width of the transition protrusion is smaller than the width of the root end, and the width L6 of the transition protrusion is 0.2 mm to 0.5 mm. And / or, the explosion-proof valve has a weak portion, and the minimum distance L7 between the centerline of the welded portion along the weld width direction and the centerline of the weak portion along the weld width direction is 3 mm to 5 mm. And / or, the explosion-proof valve has an explosion-proof protrusion. The minimum distance along the first direction between any two of the surface of the substrate away from the mounting surface, the surface of the transition sub-part away from the main sub-part, and the surface of the explosion-proof valve away from the explosion-proof protrusion is 0 mm to 1 mm. And / or, the height H4 of the reinforcing portion along the first direction is 0.8 mm to 1.5 mm.

[0013] Optionally, a groove is provided on the surface of the main body sub-part near the mounting surface, and the groove 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.

[0014] Optionally, the housing includes a shell and a cover body, the shell having an open end, and the cover body covering the open end; the shell includes a bottom plate and / or a top plate; the base plate is configured as at least one of the cover body, the bottom plate, and the top plate.

[0015] 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.

[0016] As can be seen from the above, the housing and battery cell provided in this application connect the transition sub-section to the substrate or explosion-proof valve, thereby thickening the structure of the main body sub-section connected to the transition sub-section at its location, thereby strengthening the structure of the explosion-proof valve or the area nearby.

[0017] When a battery cell experiences thermal runaway, the high-temperature gas generated inside the casing will concentrate on the explosion-proof valve. Because the main body sub-section is located near the explosion-proof valve, when the valve is under pressure, the reinforcement of the main body sub-section helps prevent deformation and tearing in the vicinity of the valve. This improves the sealing and safety of the casing and effectively prevents liquid or gas leakage during use.

[0018] Meanwhile, since the transition sub-part can fill the gap between the edge of the mounting hole and the edge of the explosion-proof valve, even if the gap between the two is large, it will not affect the connection between the substrate and the explosion-proof valve. This can reduce the dimensional accuracy requirements of the mounting hole and the explosion-proof valve, help reduce the manufacturing difficulty of the housing, and improve the yield. Attached Figure Description

[0019] 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.

[0020] Figure 1 This is a partial cross-sectional view of the outer shell of the first structure according to an embodiment of this application;

[0021] Figure 2 This is a partial perspective view of the outer shell of the second structure according to an embodiment of this application;

[0022] Figure 3 This is a partial top view of the outer shell of the second structure according to an embodiment of this application;

[0023] Figure 4 for Figure 3 Schematic diagram of the cross section AA;

[0024] Figure 5 for Figure 4 An enlarged schematic diagram of the first structure in section B before welding;

[0025] Figure 6 A schematic diagram of the reinforcing portion of the first structure of the outer casing according to an embodiment of this application;

[0026] Figure 7 A schematic diagram of the reinforcing part of the second structure of the outer shell according to an embodiment of this application;

[0027] Figure 8 A schematic diagram of the reinforcing part of the third structure of the outer casing according to an embodiment of this application;

[0028] Figure 9 for Figure 4 An enlarged schematic diagram of the second structure in section B;

[0029] Figure 10 for Figure 4 An enlarged schematic diagram of the third structure in part B;

[0030] Figure 11 for Figure 4 An enlarged schematic diagram of the first structure in section B after welding;

[0031] Figure 12 for Figure 4 An enlarged schematic diagram of the fourth structure in section B when it is not welded;

[0032] Figure 13 for Figure 4 An enlarged schematic diagram of the fourth structure in section B after welding;

[0033] Figure 14 This is a schematic diagram of the reinforcement portion of the fourth structure of the outer casing according to an embodiment of this application.

[0034] Explanation of reference numerals in the attached figures:

[0035] 100, substrate; 110, mounting hole; 120, mounting surface;

[0036] 200. Cover plate assembly; 210. Cover plate body; 220. Explosion-proof valve; 221. Explosion-proof protrusion; 222. Weak point;

[0037] 300, welded section; 300a, first welded section; 300b, second welded section;

[0038] 400, Reinforcing section; 410, Transition sub-section; 411, Transition protrusion; 412, Root end; 420, Main body sub-section; 421, Reinforcing protrusion; 430, Groove;

[0039] 500. Capacity space;

[0040] 600. Shell; 610. Side plate; 620. Top plate; 630. Bottom plate; 640. Open end;

[0041] 700. Exhaust passage. Detailed Implementation

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] Figure 1 A partial cross-sectional schematic diagram of the outer shell of the first structure is shown.

[0048] like Figure 1In 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.

[0049] 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.

[0050] like Figure 2 and Figure 3 The 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 two side plates 610, the top plate 620, and the bottom plate 630 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.

[0051] Taking the second type of shell structure as an example, the embodiments of this application will be further described.

[0052] 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.

[0053] like Figure 2 , Figure 3 , Figure 4 and Figure 5 The housing provided in this application embodiment includes: a substrate 100 having a first direction (e.g., Figure 4 and Figure 5 A mounting surface 120 (in the Z direction) is provided, and a through mounting hole 110 is formed on the mounting surface 120; an explosion-proof valve 220 is at least partially disposed within the mounting hole 110; a reinforcing part 400 includes a main body sub-part 420 and a transition sub-part 410 connected to each other, the main body sub-part 420 being disposed on the mounting surface 120, and the transition sub-part 410 being disposed along a second direction (e.g., in the Z direction). Figure 4 and Figure 5The X direction is located between the edge of the mounting hole 110 and the edge of the explosion-proof valve 220. The main body sub-part 420 is connected to the substrate 100 and / or the explosion-proof valve 220 respectively through the transition sub-part 410. The first direction is the thickness direction of the substrate 100, and the second direction is the plane direction of the mounting surface 120.

[0054] 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.

[0055] For example, the substrate 100, the explosion-proof valve 220 and the reinforcing part 400 can be made of the same material, such as SUS304 stainless steel, or they can be different, but it is necessary to ensure that the three can be welded together.

[0056] For example, the mounting surface 120 can be a plate surface of the substrate 100 disposed opposite to each other in the thickness direction.

[0057] For example, the mounting surface 120 may be close to the receiving space 500.

[0058] 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.

[0059] By connecting the transition sub-part 410 to the substrate 100 or the explosion-proof valve 220, the main body sub-part 420 connected to the transition sub-part 410 thickens the structure at its location, thereby strengthening the structure of the explosion-proof valve 220 or its surrounding area.

[0060] When the battery cell, including the casing of this embodiment, experiences thermal runaway, the high-temperature gas generated inside the casing 600 will act more concentratedly on the explosion-proof valve 220. Because the main body sub-section 420 is located near the explosion-proof valve 220, when the explosion-proof valve 220 is under pressure, the reinforcing effect of the main body sub-section 420 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.

[0061] Meanwhile, since the transition sub-part 410 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 substrate 100 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.

[0062] Figure 6 A schematic diagram of the reinforcing part 400 of the first structure is shown; Figure 7 A schematic diagram of the reinforcing part 400 of the second structure is shown.

[0063] like Figure 6 and Figure 7 In some embodiments, the reinforcing part 400 is arranged in a continuous annular pattern around the explosion-proof valve 220, such as... Figure 6 Or it can be arranged in a segmented ring shape, such as Figure 7 .

[0064] 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.

[0065] Furthermore, the above-mentioned effect can be achieved regardless of whether the reinforcing part 400 is arranged in a continuous ring or in a segmented ring. Moreover, when the reinforcing part 400 is arranged in segments, the material cost of the reinforcing part 400 can be reduced, which is beneficial for mass production.

[0066] Figure 8 A schematic diagram of the reinforcing section 400 of the third structure is shown.

[0067] like Figure 8 In some embodiments, the reinforcing part 400 is provided in at least one ring along the radial direction of the explosion-proof valve 220.

[0068] For example, the different ring reinforcement sections 400 can be configured in the same or different ways.

[0069] For example, the single-ring reinforcement 400 can be arranged in a continuous ring or in a segmented ring.

[0070] At the same time, the addition of multiple reinforcing rings 400 can further enhance the structural reinforcement of the area near the explosion-proof valve 220, and further ensure that the outer shell is not easily deformed or torn under the impact of high-temperature gas.

[0071] like Figure 5 In some embodiments, along the first direction, the main body sub-part 420 has a reinforcing protrusion 421 away from the mounting surface 120, and the explosion-proof valve 220 has an explosion-proof protrusion 221 away from the mounting surface 120. The distance H1 between the reinforcing protrusion 421 and the explosion-proof protrusion 221 is 0 mm to 3 mm.

[0072] For example, H1 can be 0mm, 1mm, 2mm or 3mm.

[0073] If H1 is too large, the thickness of the main body sub-part 420 may be too large, causing the main body sub-part 420 to occupy too much of the accommodating space 500, which in turn leads to a lower energy density of the cell including the casing.

[0074] To avoid the above problems, this embodiment limits H1 to 0mm to 3mm, which allows the main body sub-part 420 to effectively strengthen the structure it covers while avoiding the main body sub-part 420 occupying too much of the accommodating space 500, thus helping to ensure the energy density of the battery cell.

[0075] Figure 9 Showing Figure 4 An enlarged schematic diagram of the second structure in section B. Figure 10 Showing Figure 4 An enlarged schematic diagram of the third structure in part B.

[0076] like Figure 9 and Figure 10 In some embodiments, the transition sub-part 410 is integrally formed and connected to the substrate 100 (e.g., Figure 9 ) or explosion-proof valve 220 (e.g.) Figure 10 ).

[0077] The transition sub-part 410 is integrally formed and connected to the substrate 100 or the explosion-proof valve 220. On the one hand, this helps to improve the connection strength between the transition sub-part 410 and the substrate 100 or between the transition sub-part 410 and the explosion-proof valve 220, thereby making the reinforcement effect of the main sub-part 420 on the substrate 100 or 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.

[0078] In some embodiments, the transition sub-part 410 is welded to the substrate 100 or the explosion-proof valve 220.

[0079] It should be noted that the transition sub-part 410 can be soldered to one of the substrate 100 and the explosion-proof valve 220 first, and then connected to the other; or, the substrate 100, the transition sub-part 410 and the explosion-proof valve 220 can be connected together.

[0080] Designing the transition sub-part 410 to be welded to the substrate 100 or the explosion-proof valve 220 can reduce the molding difficulty of the substrate 100 and the explosion-proof valve 220, help reduce the manufacturing cost of the substrate 100 and the explosion-proof valve 220, and facilitate mass production.

[0081] Figure 11 Showing Figure 4 An enlarged schematic diagram of the first structure in section B after welding. Figure 12 Showing Figure 4 An enlarged schematic diagram of the fourth structure in section B before welding. Figure 13 Showing Figure 4 An enlarged schematic diagram of the fourth structure in section B after welding.

[0082] like Figure 3 , Figure 5 , Figure 11 , Figure 12 and Figure 13 In some embodiments, the explosion-proof valve 220, the base plate 100, and the reinforcing part 400 are independent of each other; the edge of the explosion-proof valve 220 and the edge of the mounting hole 110 are respectively welded to the transition sub-part 410 to form at least one welded part 300.

[0083] For example, the welded portion 300 is provided along the edge of the mounting hole 110.

[0084] like Figure 5 and Figure 11 When the dimension of the transition sub-part 410 along the second direction is large, the edges of the transition sub-part 410 and the mounting hole 110 can be welded to form a first welded part 300a, and the edges of the transition sub-part 410 and the explosion-proof valve can be welded to form a second welded part 300b. At this time, in order to connect the substrate 100, the explosion-proof valve 220 and the reinforcing part 400, two welding operations are required.

[0085] like Figure 12 and Figure 13 When the size of the transition sub-part 410 along the second direction is small, when the transition sub-part 410, the edge of the explosion-proof valve 220 and the edge of the mounting hole 110 are welded, the transition sub-part 410 can form a molten pool in one welding, so that the substrate 100, the reinforcing part 400 and the explosion-proof valve 220 can be interconnected in one welding.

[0086] By using the transition sub-part 410 of the reinforcing part 400, the substrate 100, the reinforcing part 400, and the explosion-proof valve 220 are welded into a single unit. This is equivalent to increasing the thickness of the region of the substrate 100 near the weld joint 300 and also increasing the thickness of the region of the explosion-proof valve 220 near the weld joint 300 through the main body 420 of the reinforcing part 400. This improves the welding quality between the substrate 100 and the explosion-proof valve 220; on the other hand, it combines... Figure 11 and Figure 13 It can be seen that although the welded part 300 is the connection between the substrate 100 and the explosion-proof valve 220, the main body 420 located at this position is an integrally formed structure. Since the integrally formed main body 420 has greater strength, it can improve the strength of the welded part 300 at the corresponding position.

[0087] like Figure 11 and Figure 13 In some embodiments, the thickness H2 of the substrate 100 is t, and the weld depth H3 of the welded portion 300 along the first direction is 2t to 5t.

[0088] For example, t can be 0.15 to 0.3 mm. For instance, t can be 0.15 mm, 0.2 mm, 0.25 mm, or 0.3 mm.

[0089] For example, H3 can be 2t, 2.5t, 3t, 3.5t, 4t, 4.5t, or 5t.

[0090] If H3 is too small, it will be difficult for the reinforcing part 400, the substrate 100 and the explosion-proof valve 220 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, it may weld through the main body sub-part 420 during welding, which will also result in insufficient strength of the welding welding part 300 and the risk of cracking and leaking gas.

[0091] To avoid the above problems, this embodiment limits H3 to 2t to 5t, which can ensure that the reinforcing part 400, the substrate 100 and the explosion-proof valve 220 can form a relatively reliable connection through the welding part 300, and can also ensure the welding quality of the welding part 300, reducing the risk of cracking and leakage of the welding part 300.

[0092] like Figure 11 and Figure 13 In some embodiments, the welded portion 300 extends along the edge of the mounting hole 110, and the radial dimension of the welded portion 300 along the mounting hole 110 is defined as the weld width of the welded portion 300, where the weld width L1 is 1t to 5t.

[0093] For example, L1 can be 1t, 1.5t, 2t, 2.5t, 3t, 3.5t, 4t, 4.5t, or 5t.

[0094] If L1 is too small, it will be difficult for the reinforcing part 400, the substrate 100 and the explosion-proof valve 220 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 the substrate 100 and the explosion-proof valve 220 to deform significantly, affecting the welding quality of the welding part 300.

[0095] To avoid the above problems, this embodiment limits L1 to 1t to 5t, which can ensure that the reinforcing part 400, the substrate 100 and the explosion-proof valve 220 form a relatively reliable connection through the welding part 300, and also ensure the welding quality of the welding part 300, reducing the risk of cracking and leakage of the welding part 300.

[0096] like Figure 11 and Figure 13 In some embodiments, the explosion-proof valve 220 is provided with a weak part 222, and the minimum distance L7 between the center line of the welded part 300 along the weld width direction and the center line of the weak part 222 along the weld width direction is 3mm to 5mm.

[0097] For example, the weak point 222 can be a groove, which can be in the shape of a cross or a C. When the cell experiences thermal runaway, the groove can be broken by pressure, and the area near or around the groove can be bent by pressure, so that the high-temperature gas inside the cell can be released to the outside.

[0098] For example, L7 can be 3mm, 3.5mm, 4mm, 4.5mm or 5mm.

[0099] Since the welded portion 300 is arranged around the edge of the explosion-proof valve 220, if L7 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 L7 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.

[0100] To avoid the above problems, this embodiment limits L7 to 3mm to 5mm. While avoiding the influence of welding heat and stress concentration 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.

[0101] like Figure 3 In some embodiments, the minimum distance L2 between the edge of the mounting hole 110 and the edge of the substrate 100 is 0.5 mm to 10 mm.

[0102] For example, L2 can be 0.5mm, 1mm, 1.5mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm.

[0103] If L2 is too small, deformation of the substrate 100 at the edge of the mounting hole 110 may occur during the stamping process, affecting the welding quality of the substrate 100 and the transition sub-part 410. Simultaneously, stress concentration may occur during welding of the substrate 100 and the transition sub-part 410. Furthermore, the strength of the substrate 100 around the mounting hole 110 will decrease, and excessive shear force may cause the substrate 100 on the opposite side of the weak part 222 to tear when the weak part 222 is subjected to pressure and fractures. If L2 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.

[0104] To avoid the above problems, this embodiment limits L2 to 0.5mm to 10mm, which ensures that the explosion-proof valve 220 has sufficient installation space, can promptly discharge the high-temperature gas inside the battery cell after the explosion-proof valve 220 is opened, can also ensure the strength of the area of ​​the substrate 100 near the mounting hole 110, can ensure the welding quality of the substrate 100 and the transition sub-part 410, can reduce the risk of the substrate 100 tearing, and can help improve the safety of the battery cell.

[0105] like Figure 5 and Figure 12 In some embodiments, the height H4 of the reinforcing part 400 along the first direction is 0.8 mm to 1.5 mm.

[0106] For example, H4 can be 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm or 1.5mm.

[0107] If H4 is too small, it may weld through the main body sub-part 420 when forming the fusion part 300, 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 main body sub-part 420 to occupy too much space 500, which will reduce the energy density of the cell.

[0108] To avoid the above problems, this embodiment limits H4 to 0.8mm to 1.5mm, which can not only ensure the welding quality of the fusion section 300 and reduce the risk of cracking and leakage of the fusion section 300, but also avoid the main body sub-section 420 occupying too much of the storage 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.

[0109] like Figure 5 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 410 away from the main body sub-part 420, 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] like Figure 11 and Figure 13 In some embodiments, the dimension of the reinforcing portion 400 along the weld width direction of the weld portion 300 is defined as the width, and the minimum distance L3 between the edge of the weld portion 300 along the weld width direction and the edge of the reinforcing portion 400 along the width direction is 0.1 mm to 2 mm.

[0115] For example, along the weld width direction, the center line of the main body sub-part 420 and the center line of the welded part 300 can be aligned or offset.

[0116] For example, the cross-sectional shape of the welded portion 300 along the extension direction can be U-shaped.

[0117] For example, L3 can be 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.

[0118] If L3 is too small, the side wall of the main body sub-part 420 may be welded through when forming the welded part 300, resulting in insufficient welding strength of the welded part 300 and the risk of cracking and leakage. If L3 is too large, the size of the main body sub-part 420 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 main body sub-part 420 to occupy too much space 500, which will reduce the energy density of the cell.

[0119] To avoid the above problems, this embodiment limits L3 to 0.1mm to 2mm, which can ensure the welding quality of the fusion section 300, reduce the risk of rupture and leakage of the fusion section 300, and avoid the main body sub-section 420 occupying too much of the storage 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.

[0120] like Figure 11 and Figure 13 In some embodiments, the width L4 of the main body sub-part 420 is 1 mm to 5 mm.

[0121] For example, L4 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm.

[0122] If L4 is too small, it may weld through the side wall of the main body sub-part 420 when forming the fusion part 300, 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 cell, but also cause the main body sub-part 420 to occupy too much space 500, which will reduce the energy density of the cell.

[0123] To avoid the above problems, this embodiment limits L4 to 1mm to 5mm, which can ensure the welding quality of the fusion section 300, reduce the risk of rupture and leakage of the fusion section 300, and avoid the main body sub-section 420 occupying too much of the accommodating space 500, which helps to ensure the energy density of the battery cell and reduce the overall weight and manufacturing cost of the battery cell.

[0124] like Figure 5 In some embodiments, the width L5 of the transition sub-part 410 is 0.1 mm to 5 mm.

[0125] For example, the transition sub-part 410 has a transition protrusion 411 away from the main sub-part 420 and a root end 412 close to the main sub-part 420. The width of the transition protrusion 411 can be the same as the width of the root end 412. In this case, the cross-sectional shape of the transition sub-part 410 perpendicular to the extension direction is rectangular.

[0126] For example, L5 can be 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm.

[0127] If L5 is too small, the transition sub-part 410 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, a small L5 will also result in low strength of the transition sub-part 410, which may cause bending of the transition sub-part 410 during alignment of the substrate 100, the explosion-proof valve 220, and the transition sub-part 410, also affecting the welding quality of the fusion section 300. If L5 is too large, interference may occur between the transition sub-part 410, the substrate 100, and the explosion-proof valve 220, making welding impossible.

[0128] To avoid the above problems, this embodiment limits L5 to 0.1mm to 5mm, which can avoid interference between the transition sub-part 410, the substrate 100 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 of the welded part 300.

[0129] like Figure 12 In some embodiments, the width of the transition protrusion 411 is less than the width of the root end 412, and the width L6 of the transition protrusion 411 is 0.2 mm to 0.5 mm.

[0130] For example, L6 can be 0.2mm, 0.3mm, 0.4mm or 0.5mm.

[0131] For example, in this embodiment, the cross-sectional shape of the transition sub-part 410 perpendicular to the extension direction is trapezoidal.

[0132] By designing the width of the transition protrusion 411 to be relatively small, at least the entire transition protrusion 411 can form a molten pool in one welding operation, so that the substrate 100, the reinforcing part 400 and the explosion-proof valve 220 can be interconnected in one welding operation.

[0133] If L6 is too small, melting the transition sub-part 410 will not be enough to reliably connect the edge of the spaced substrate 100 and the edge of the explosion-proof valve 220. If L6 is too large, it may cause interference between the transition sub-part 410, the substrate 100 and the explosion-proof valve 220, making welding impossible. It may also prevent the transition protrusion 411 from being completely melted by a single welding operation, thus preventing the edge of the substrate 100 and the edge of the explosion-proof valve 220 from being connected.

[0134] To avoid the above problems, this embodiment limits L6 to 0.2mm to 0.5mm, which can avoid interference between the transition sub-section 410, the substrate 100 and the explosion-proof valve 220, and also ensure the welding quality of the fusion section 300, reduce the risk of rupture and leakage of the fusion section 300. The substrate 100 and the explosion-proof valve 220 can be reliably connected by a single welding, which helps to simplify the welding process and improve the manufacturing efficiency of the battery cell.

[0135] Figure 14 A partial cross-sectional schematic diagram of the fourth structure of the reinforcing section 400 is shown.

[0136] like Figure 5 and Figure 14 In some embodiments, a groove 430 is provided on the surface of the main body sub-part 420 near the mounting surface 120. The groove 430 passes through the side wall of the main body sub-part 420 radially along the mounting hole 110. The groove 430 and the mounting surface 120 enclose each other to form an exhaust channel 700.

[0137] For example, the radial cross-sectional shape of the groove 430 can be semi-circular, rectangular, triangular or arc-shaped.

[0138] For example, the transition sub-parts 410 are segmented along the edge of the mounting hole 110, and the grooves 430 may be provided between two adjacent transition sub-parts 410.

[0139] For example, the groove 430 may also extend through the root end 412 of the transition sub-section 410.

[0140] 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 420 of the reinforcing part 400 from obstructing the flow of high-temperature gas, and helps to quickly expel the high-temperature gas from the containment space 500 into the battery cell, thereby improving the safety of the battery cell.

[0141] 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.

[0142] A battery cell includes a housing as described in the various embodiments above.

[0143] It should be noted that some embodiments of this application have been described above. Other embodiments are within the scope of the appended claims.

[0144] 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.

[0145] 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.

[0146] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application is limited to these examples; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0147] 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.

[0148] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A casing, characterized in that, include: The substrate has a mounting surface disposed along a first direction, and the mounting surface is formed with a through mounting hole; An explosion-proof valve is at least partially disposed within 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 a second direction. The main body sub-part is connected to the substrate and / or the explosion-proof valve respectively through the transition sub-part. The first direction is the thickness direction of the substrate, and the second direction is the planar direction of the mounting surface.

2. 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 valve.

3. The outer casing according to claim 2, characterized in that, The reinforcing part is arranged in at least one ring along the radial direction of the explosion-proof valve.

4. The outer casing according to claim 1, characterized in that, Along the first direction, the main body sub-part has a reinforcing protrusion away from the mounting surface, and the explosion-proof valve has an explosion-proof protrusion away from the mounting surface. The distance H1 between the reinforcing protrusion and the explosion-proof protrusion is 0 mm to 3 mm.

5. The outer casing according to claim 1, characterized in that, The transition sub-part is integrally formed and connected to the substrate or the explosion-proof valve; or... The transition sub-part is welded to the substrate or the explosion-proof valve.

6. The outer casing according to claim 1, characterized in that, The explosion-proof valve, the base plate, and the reinforcing part are independent of each other; the edge of the explosion-proof valve and the edge of the mounting hole are respectively welded to the transition part to form at least one welded part.

7. The outer casing according to claim 6, characterized in that, The thickness H2 of the substrate is t, where t is from 0.15 mm to 0.3 mm; The weld depth H3 along the first direction is 2t to 5t, and / or; The welded portion extends along the edge of the mounting hole, and the radial dimension of the welded portion along the mounting hole is defined as the weld width L1, which is 1t to 5t; and / or The minimum distance L2 between the edge of the mounting hole and the edge of the substrate is 0.5 mm to 10 mm; and / or, The dimension of the reinforcing portion along the weld width direction is defined as its width, and the minimum distance L3 between the edge of the welded portion along the weld width direction and the edge of the reinforcing portion along the width direction is 0.1 mm to 2 mm; and / or, The width L4 of the main body sub-part is 1mm to 5mm; and / or, The width L5 of the transition sub-section is 0.1 mm to 5 mm; and / or, The transition sub-part has a transition protrusion distant from the main sub-part and a root end close to the main sub-part, the width of the transition protrusion being smaller than the width of the root end, and the width L6 of the transition protrusion being 0.2 mm to 0.5 mm; and / or, The explosion-proof valve is provided with a weak point, and the minimum distance L7 between the centerline of the welded portion along the weld width direction and the centerline of the weak point along the weld width direction is 3mm to 5mm; and / or, The explosion-proof valve has an explosion-proof protrusion; the minimum distance along the first direction between any two of the following three surfaces: the surface of the substrate away from the mounting surface, the surface of the transition sub-part away from the main body sub-part, and the surface of the explosion-proof valve away from the explosion-proof protrusion; and / or, The height H4 of the reinforcing part along the first direction is 0.8 mm to 1.5 mm.

8. The outer casing according to claim 1, 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.

9. The outer casing according to claim 1, characterized in that, The outer casing includes a housing and a cover plate body, the housing having an open end, and the cover plate body covering the open end; the housing includes a bottom plate and / or a top plate; The substrate is constructed as at least one of the cover plate body, the bottom plate, and the top plate.

10. A battery cell, characterized in that, Includes the housing as described in any one of claims 1 to 9.

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