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, and the mounting surface is provided with an anti-explosion valve; the reinforcing part is connected to the mounting surface and / or the anti-explosion valve; in the first direction, the orthographic projection of the reinforcing part on the mounting surface is defined as the projection of the reinforcing part, the orthographic projection of the anti-explosion valve on the mounting surface is defined as the projection of the anti-explosion valve, and the projection of the reinforcing part is located on at least one side of the projection of the anti-explosion valve; the first direction is the thickness direction of the substrate. According to the shell and the battery cell provided by the invention, when the battery cell is subjected to thermal runaway, high-temperature gas generated in the shell can act on the anti-explosion valve in a relatively concentrated manner. Due to the fact that the reinforcing part is arranged at the position close to the anti-explosion valve, when the anti-explosion valve is pressed, the area close to the anti-explosion valve is not prone to deformation and tearing through the reinforcing effect of the reinforcing part, the sealing performance and 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] The present application relates to the technical field of energy storage, in particular to a shell and a battery cell. BACKGROUND

[0002] The shell of the battery cell includes a shell and a cover plate assembly, and the cover plate assembly covers the open end of the shell to form a containing space for containing a bare battery cell. In the related art, the cover plate body in the cover plate assembly is welded with the shell, and both the shell and the cover plate body are made of aluminum alloy. The shell and the cover plate body have large thickness, low strength and poor high-temperature resistance, and it is difficult for them to withstand large pressure. When the battery cell has thermal runaway, the shell and the cover plate body are prone to burn-through, and the battery cell has a large risk of thermal diffusion. At the same time, the shell and the cover plate body with large thickness also occupy too much containing space, resulting in low energy density of the battery cell.

[0003] The applicant finds that if the shell and the cover plate body are made of steel, the thickness of the shell and the cover plate body can be designed to be small because the strength of steel is relatively large and the high-temperature resistance of steel is good, so as to improve the energy density of the battery cell.

[0004] However, taking the explosion-proof valve arranged in the shell as an example, when the shell is designed to be thin, if the battery cell has thermal runaway, the shell near the explosion-proof valve may have the risk of deformation, tearing and leakage. CONTENT OF THE INVENTION

[0005] Therefore, the present application aims to provide a shell and a battery cell to solve the above-mentioned technical problems.

[0006] To achieve the above-mentioned purpose, the present application provides a shell in the first aspect, which includes: a base plate having a mounting surface and provided with an explosion-proof valve on the mounting surface; a reinforcing part connected to the mounting surface and / or the explosion-proof valve; in a first direction, a projection of the reinforcing part on the mounting surface is defined as a reinforcing part projection, a projection of the explosion-proof valve on the mounting surface is defined as an explosion-proof valve projection, and the reinforcing part projection is located on at least one side of the explosion-proof valve projection; and the first direction is the thickness direction of the base plate.

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

[0008] Optionally, the reinforcing part includes a first sub-part and a second sub-part, and in the planar direction of the mounting surface, the second sub-part is located on the side of the first sub-part away from the explosion-proof valve.

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

[0010] Optionally, the reinforcing portion is integrally connected to the substrate or the explosion-proof valve; or the reinforcing portion is welded to the substrate or the explosion-proof valve.

[0011] Optionally, the explosion-proof valve is integrally connected to the substrate, and the explosion-proof valve comprises a weak portion formed by etching; or the explosion-proof valve is welded to the substrate, and the explosion-proof valve comprises a weak portion formed by stamping.

[0012] Optionally, the explosion-proof valve, the substrate, and the reinforcing portion are independent of each other; the substrate is formed with a through mounting hole, at least part of the explosion-proof valve is arranged in the mounting hole, an edge of the explosion-proof valve, an edge of the mounting hole, and the reinforcing portion are welded to form a fusion portion.

[0013] Optionally, a thickness of the substrate is t, a fusion depth H3 of the fusion portion along the first direction is 2t to 5t; and / or the fusion portion extends along the edge of the mounting hole, a dimension of the fusion portion along a radial direction of the mounting hole is defined as a fusion width of the fusion portion, the fusion width L1 is 1t to 5t; and / or a 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 a distance L3 between a center line of the fusion portion along the fusion width direction and a center line of the weak portion along the fusion width direction is 3 mm to 5 mm; and / or a height H2 of the reinforcing portion along the first direction is 0.8 mm to 1.5 mm; and / or a dimension L4 of the reinforcing portion along the fusion width direction is 2 mm to 3 mm.

[0014] Optionally, the shell comprises a shell body and a cover plate body, the shell body has an open end, and the cover plate body covers the open end; the shell body comprises a bottom plate and / or a top plate; the substrate is configured as at least one of the cover plate body, the bottom plate, and the top plate.

[0015] Based on the same inventive concept, the second aspect of the present application further provides an electric cell comprising the shell as described in the first aspect.

[0016] As can be seen from the above, the shell and the electric cell provided by the present application can make the high-temperature gas generated in the shell body more concentrated on the explosion-proof valve when the electric cell is in thermal runaway. Since the reinforcing portion is arranged near the explosion-proof valve, when the explosion-proof valve is pressed, the reinforcing portion can prevent the area near the explosion-proof valve from being deformed and torn, which helps to improve the sealing performance and safety of the shell, and can effectively prevent the shell from leaking liquid or gas during use. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a partial cross-sectional view of the outer shell of the first structure according to an embodiment of this application;

[0019] Figure 2 This is a partial perspective view of the outer shell of the second structure according to an embodiment of this application;

[0020] Figure 3 This is a partial top view of the outer shell of the second structure according to an embodiment of this application;

[0021] Figure 4 for Figure 3 Schematic diagram of the cross section AA in the middle;

[0022] Figure 5 for Figure 4 An enlarged schematic diagram of the first structure in section B before welding;

[0023] Figure 6 A schematic diagram of the reinforcing portion of the first structure of the outer casing according to an embodiment of this application;

[0024] Figure 7 A schematic diagram of the reinforcing portion of the second structure of the outer casing according to an embodiment of this application;

[0025] Figure 8 A schematic diagram of the reinforcing part of the third structure of the outer casing according to an embodiment of this application;

[0026] Figure 9 for Figure 4 An enlarged schematic diagram of the second structure in section B;

[0027] Figure 10 for Figure 4 An enlarged schematic diagram of the third structure in part B;

[0028] Figure 11 for Figure 4 Enlarged schematic diagram of the fourth structure in Part B;

[0029] Figure 12 for Figure 4 An enlarged schematic diagram of the first structure in section B after welding.

[0030] Reference Signs List:

[0031] 100 substrate; 110 mounting hole; 120 mounting surface;

[0032] 200 cover assembly; 210 cover body; 220 explosion-proof valve; 221 explosion-proof protrusion; 222 weak portion;

[0033] 300 fusion portion;

[0034] 400 reinforcing portion; 410 first sub-portion; 420 second sub-portion; 430 reinforcing protrusion;

[0035] 500 accommodation space;

[0036] 600 housing; 610 side plate; 620 top plate; 630 bottom plate; 640 open end. DETAILED DESCRIPTION

[0037] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0038] It should be noted that: unless otherwise specified, the relative arrangement of the components, numerical expressions and values set forth in these embodiments do not limit the scope of the present application.

[0039] At the same time, it should be understood that, in order to facilitate the description, the size of each part shown in the drawings is not drawn in accordance with the actual proportion relationship.

[0040] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way limiting on the application or its use. The description of at least one exemplary embodiment is actually only illustrative and in no way limits the application and its applications or uses.

[0041] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be understood as the usual meaning understood by those skilled in the art to which the embodiments of the present application belong. The "first", "second" and similar words used in the embodiments of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. "Include" or "contain" and similar words mean that the elements or objects before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connected" or "connected" and similar words are not limited to physical or mechanical connection, but can include electrical connection, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to represent relative positional relationship, when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0042] Figure 1 A partial cross-sectional view of a first structure of the shell is shown.

[0043] As Figure 1 In some embodiments, the shell comprises a casing 600 and a cover plate assembly 200, the casing 600 can comprise a bottom plate 630, four edges of the bottom plate 630 are respectively connected with a side plate 610, and four side plates 610 are respectively connected with the edges of the bottom plate 630 to form an open end 640. The cover plate assembly 200 comprises a cover plate body 210 and an explosion-proof valve 220 arranged on the cover plate body 210, and the cover plate body 210 covers the open end 640, so that the casing 600 and the cover plate assembly 200 form a containing space 500 for containing bare battery cells.

[0044] Figure 2 A partial perspective view of a second structure of the shell is shown, Figure 3 A partial top view of the second structure of the shell is shown.

[0045] As Figure 2 And Figure 3 The casing 600 can have two open ends 640, the casing 600 can comprise two side plates 610, and a top plate 620 and a bottom plate 630 arranged oppositely, the side plate 610 is connected between the long edge of the top plate 620 and the long edge of the bottom plate 630, and the two side plates 610, the top plate 620 and the bottom plate 630 form a cylindrical structure, and the two ends of the cylindrical structure are the open ends 640. The explosion-proof valve 220 can be connected to the top plate 620.

[0046] The shell of the second structure is taken as an example to further illustrate the embodiments of the present application.

[0047] Figure 4 A partial cross-sectional view of the A-A section in Figure 3 is shown, Figure 5 An enlarged view of the first structure of the B part in Figure 4 is shown.

[0048] As Figure 3 , Figure 4 And Figure 5 The shell provided by the embodiments of the present application comprises: a base plate 100 having a mounting surface 120, and an explosion-proof valve 220 arranged on the mounting surface 120; a reinforcing portion 400 connected to the mounting surface 120 and / or the explosion-proof valve 220; and a first direction (such as Figure 3 And Figure 4 , the projection of the reinforcing portion 400 on the mounting surface 120 is defined as a reinforcing portion projection, and the projection of the explosion-proof valve 220 on the mounting surface 120 is defined as an explosion-proof valve projection, the reinforcing portion projection is located on at least one side of the explosion-proof valve projection; and the first direction is the thickness direction of the base plate 100.

[0049] Exemplarily, the substrate 100 can be the cover body 210, or can be at least one of the top plate 620, the bottom plate 630 and the side plate 610, and the accommodation space 500 is located at one side of the substrate 100 along the thickness direction thereof.

[0050] Exemplarily, the materials of the substrate 100, the explosion-proof valve 220 and the reinforcing portion 400 can be the same (for example, all are SUS304 stainless steel) and can be different, but need to ensure that welding can be achieved between the three.

[0051] Exemplarily, the mounting surface 120 can be a plate surface of the substrate 100 arranged oppositely along the thickness direction.

[0052] The mounting surface 120 or the explosion-proof valve 220 is connected to the reinforcing portion 400, which is equivalent to thickening the structure at the position thereof by the reinforcing portion 400, so as to reinforce the structure of the area near the explosion-proof valve 220.

[0053] When the battery cell including the shell of the present embodiment appears thermal runaway, the high-temperature gas generated inside the shell 600 will act on the explosion-proof valve 220 more concentratedly. Since the reinforcing portion 400 is arranged near the explosion-proof valve 220, when the explosion-proof valve 220 is pressed, the area near the explosion-proof valve 220 is not easy to deform and tear by the reinforcing effect of the reinforcing portion 400, which helps to improve the sealing performance and safety of the shell, and can effectively prevent the shell from leaking liquid or gas during use.

[0054] Figure 6 A schematic view of the reinforcing portion 400 of the first structure is shown; Figure 7 A schematic view of the reinforcing portion 400 of the second structure is shown.

[0055] As Figure 6 and Figure 7 In some embodiments, the reinforcing portion 400 is arranged in a continuous annular shape around the explosion-proof valve 220 (such as Figure 6 ) or in a segmented annular shape (such as Figure 7 ).

[0056] The reinforcing portion 400 is arranged in an annular shape around the explosion-proof valve 220, which can make the reinforcing effect of the reinforcing portion 400 more obvious, and further ensure that the shell is not easy to deform and tear under the impact of high-temperature gas.

[0057] At the same time, whether the reinforcing portion 400 is arranged in a continuous annular shape or a segmented annular shape, the above-mentioned effect can be achieved. Moreover, when the reinforcing portion 400 is arranged in a segmented manner, the material cost of the reinforcing portion 400 can be reduced, which is conducive to mass production.

[0058] Figure 8 A schematic view of the reinforcing portion 400 of the third structure is shown.

[0059] As Figure 5 And Figure 8 In some embodiments, the reinforcing portion 400 comprises a first sub-portion 410 and a second sub-portion 420, and the second sub-portion 420 is located on the side of the first sub-portion 410 away from the explosion-proof valve 220 along the planar direction of the mounting surface 120 (e.g., the XY direction in the figure). Figure 8

[0060] For example, the first sub-portion 410 can be arranged in a continuous annular manner or in a segmented annular manner.

[0061] For example, the second sub-portion 420 can be arranged in a continuous annular manner or in a segmented annular manner, and the arrangement manners of the first sub-portion 410 and the second sub-portion 420 can be the same or different.

[0062] When the first sub-portion 410 and the second sub-portion 420 are arranged simultaneously, the first sub-portion 410 can form a first annular reinforcing structure around the explosion-proof valve 220, and the second sub-portion 420 can form a second annular reinforcing structure around the explosion-proof valve 220. The first sub-portion 410 and the second sub-portion 420 can further improve the reinforcing effect of the reinforcing portion 400 and further ensure that the shell is not easily deformed and torn under the impact of high-temperature gas.

[0063] It should be noted that the present embodiment is only illustrative, and a plurality of annular reinforcing structures can be further arranged on the side of the second sub-portion 420 away from the first sub-portion 410, which is not limited herein.

[0064] As Figure 5 In some embodiments, the reinforcing portion 400 has a reinforcing protrusion 430 away from the mounting surface 120, the explosion-proof valve 220 has an explosion-proof protrusion 221 away from the mounting surface 120, and the distance H1 between the reinforcing protrusion 430 and the explosion-proof protrusion 221 is 0 mm to 3 mm.

[0065] For example, H1 can be 0 mm, 1 mm, 2 mm, or 3 mm.

[0066] If H1 is too large, the thickness of the reinforcing portion 400 can be too large, which can cause the reinforcing portion 400 to occupy too much accommodation space 500, and thus the energy density of the battery cell including the shell is relatively low.

[0067] In order to avoid the above problems, the present embodiment limits H1 to 0 mm to 3 mm, which can enable the reinforcing portion 400 to effectively reinforce the structure covered thereby while avoiding the reinforcing portion 400 from occupying too much accommodation space 500, and thus helps to ensure the energy density of the battery cell.

[0068] Figure 9 It is shown that Figure 4 ​An enlarged schematic view of the second structure of the middle B part, Figure 10 An enlarged schematic view of the third structure of the middle B part is shown. Figure 4 An enlarged schematic view of the third structure of the middle B part is shown.

[0069] As Figure 9 and Figure 10 In some embodiments, the reinforcing part 400 is integrally formed with the base plate 100 (such as Figure 9 ) or the explosion-proof valve 220 (such as Figure 10 ).

[0070] The reinforcing part 400 is integrally formed with the base plate 100 or the explosion-proof valve 220, which on the one hand helps to improve the connection strength between the reinforcing part 400 and the base plate 100 or between the reinforcing part 400 and the explosion-proof valve 220, so that the reinforcing effect of the reinforcing part 400 on the base plate 100 or on the explosion-proof valve 220 is more stable and reliable. On the other hand, it also helps to simplify the assembly process of the shell and improve the assembly efficiency, which is conducive to mass production.

[0071] In some embodiments, the reinforcing part 400 is welded to the base plate 100 or the explosion-proof valve 220.

[0072] It should be noted that when the base plate 100 and the explosion-proof valve 220 are independent of each other, the reinforcing part 400 can be welded to one of the base plate 100 and the explosion-proof valve 220. Then, the connection between the base plate 100 and the explosion-proof valve 220 is performed, or the connection between the base plate 100, the reinforcing part 400 and the explosion-proof valve 220 is performed.

[0073] Designing the reinforcing part 400 to be welded to the base plate 100 or the explosion-proof valve 220 can reduce the molding difficulty of the base plate 100 and the explosion-proof valve 220, which helps to reduce the preparation cost of the base plate 100 and the explosion-proof valve 220, and is conducive to mass production.

[0074] Figure 11 An enlarged schematic view of the fourth structure of the middle B part is shown. Figure 4 An enlarged schematic view of the fourth structure of the middle B part is shown.

[0075] Figure 11 In some embodiments, the explosion-proof valve 220 is integrally formed with the base plate 100, and the explosion-proof valve 220 includes a weak part 222 formed by etching; or, as Figure 5 , the explosion-proof valve 220 is welded to the base plate 100, and the explosion-proof valve 220 includes a weak part 222 formed by stamping.

[0076] For example, the explosion-proof valve 220 can have a sheet structure.

[0077] Exemplarily, the weak part 222 can be a notch, and the notch can be in a "cross" shape or a C shape. When the battery cell including the explosion-proof valve 222 of the embodiment has thermal runaway, the notch can be broken under pressure, and the area near or around the notch can be bent under pressure, so that the high-temperature gas inside the battery cell is released outward.

[0078] The explosion-proof valve 220 and the base plate 100 are connected by integrally formed connection, 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 the internal high-temperature gas. At the same time, when the explosion-proof valve 220 and the base plate 100 are integrally formed and connected, the explosion-proof valve 220 and the base plate 100 can be configured as a flat plate structure, thereby reducing the space occupied by the explosion-proof valve 220, and helping to improve the energy density of the battery cell including the shell.

[0079] The explosion-proof valve 220 and the base plate 100 are connected by welding, which helps to reduce the forming difficulty of the base plate 100 and the explosion-proof valve 220, and the structural design of the explosion-proof valve 220 can be flexibly adjusted according to the overall structure of the shell, so that the explosion-proof valve 220 can be timely and smoothly opened when the battery cell has thermal runaway, and helps to improve the safety of the battery cell including the shell.

[0080] Figure 12 It is shown that Figure 4 The first structure of the middle B part is shown in an enlarged view after welding.

[0081] As Figure 3 , Figure 5 and Figure 12 , in some embodiments, the explosion-proof valve 220, the base plate 100 and the reinforcing part 400 are independent of each other; the base plate 100 is formed with a through mounting hole 110, at least part of the explosion-proof valve 220 is arranged in the mounting hole 110, the edge of the explosion-proof valve 220, the edge of the mounting hole 110 and the reinforcing part 400 are welded, and a fusion part 300 is formed.

[0082] 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, and the fusion part 300 is arranged along the edge of the mounting hole 110.

[0083] Exemplarily, when welding, two of the reinforcing part 400, the base plate 100 and the explosion-proof valve 220 can be pre-welded first, and then the three are welded as a whole.

[0084] In combination with Figure 5 and Figure 12The substrate 100, the reinforcing portion 400 and the explosion-proof valve 220 are welded as a whole, which is equivalent to increasing the thickness of the substrate 100 in the region close to the welding portion 300 and the thickness of the explosion-proof valve 220 in the region close to the welding portion 300 through the reinforcing portion 400. On the one hand, the welding quality between the substrate 100 and the explosion-proof valve 220 can be improved; on the other hand, the welding portion 300 is combined with the reinforcing portion 400, which can improve the strength of the welding portion 300. Figure 12 It can be seen that, although the welding portion 300 is the connection between the substrate 100 and the explosion-proof valve 220, the reinforcing portion 400 located at this position is an integral structure. Since the integral reinforcing portion 400 itself has greater strength, it can improve the strength of the welding portion 300 at the corresponding position.

[0085] As shown in FIG. 1, the substrate 100 is provided with a reinforcing portion 400. The reinforcing portion 400 is arranged in the region close to the welding portion 300 of the substrate 100. Figure 12 In some embodiments, the thickness H4 of the substrate 100 is t, and the penetration H3 of the welding portion 300 in the first direction is 2t to 5t.

[0086] For example, t can be 0.15 mm, 0.2 mm, 0.25 mm or 0.3 mm.

[0087] For example, H3 can be 2t, 2.5t, 3t, 3.5t, 4t, 4.5t or 5t.

[0088] If H3 is too small, the reinforcing portion 400, the substrate 100 and the explosion-proof valve 220 are difficult to form a relatively reliable connection through the welding portion 300, and the welding portion 300 still has the risk of rupture and leakage. If H3 is too large, the reinforcing portion 400 can be welded through during welding, which also leads to insufficient strength of the welding portion 300 and the risk of rupture and leakage.

[0089] In order to avoid the above problems, H3 is limited to 2t to 5t in the embodiment, which can not only ensure that the reinforcing portion 400, the substrate 100 and the explosion-proof valve 220 can form a relatively reliable connection through the welding portion 300, but also ensure the welding quality of the welding portion 300 and reduce the risk of rupture and leakage of the welding portion 300.

[0090] As shown in FIG. 1, the substrate 100 is provided with a reinforcing portion 400. The reinforcing portion 400 is arranged in the region close to the welding portion 300 of the substrate 100. Figure 12 In some embodiments, the welding portion 300 extends along the edge of the mounting hole 110, and the size of the welding portion 300 in the radial direction of the mounting hole 110 is defined as the fusion width of the welding portion 300. The fusion width L1 is 1t to 5t.

[0091] For example, L1 can be 1t, 1.5t, 2t, 2.5t, 3t, 3.5t, 4t, 4.5t or 5t.

[0092] If L1 is too small, the reinforcing portion 400, the substrate 100 and the explosion-proof valve 220 are difficult to form a relatively reliable connection through the fusion portion 300, and the fusion portion 300 still has a risk of rupture and leakage; if L1 is too large, it may cause the substrate 100 and the explosion-proof valve 220 to deform greatly, affecting the welding quality of the fusion portion 300.

[0093] To avoid the above problems, the embodiment limits L1 to 1 t to 5 t, which can not only ensure that the reinforcing portion 400, the substrate 100 and the explosion-proof valve 220 form a relatively reliable connection through the fusion portion 300, but also ensure the welding quality of the fusion portion 300 and reduce the risk of rupture and leakage of the fusion portion 300.

[0094] As shown in FIG. 1, 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. Figure 3

[0095] For example, L2 can be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm.

[0096] If L2 is too small, when the mounting hole 110 is punched, the substrate 100 at the edge of the mounting hole 110 may deform, thereby affecting the welding quality of the substrate 100 and the explosion-proof valve 220; at the same time, stress concentration may occur during welding of the substrate 100 and the explosion-proof valve 220, which will also affect the welding quality of the substrate 100 and the explosion-proof valve 220; in addition, the strength of the substrate 100 around the mounting hole 110 will also be reduced, and when the weak portion 222 is broken under pressure, excessive shear force may cause the substrate 100 on the opposite side of the weak portion 222 to tear. If L2 is too large, the size of the explosion-proof valve 220 will be too small, which is not conducive to the timely discharge of high-temperature gas inside the battery cell when the battery cell is in thermal runaway.

[0097] To avoid the above problems, the embodiment limits L2 to 0.5 mm to 10 mm, which can not only ensure that the explosion-proof valve 220 has a relatively sufficient setting space to ensure that the high-temperature gas inside the battery cell can be discharged in time after the explosion-proof valve 220 is opened, but also ensure the strength of the area of the substrate 100 close to the mounting hole 110, ensure the welding quality of the substrate 100 and the explosion-proof valve 220, and reduce the risk of tearing of the substrate 100, which helps to improve the safety of the battery cell.

[0098] As shown in FIG. 1, in some embodiments, the distance L3 between the center line of the fusion portion 300 along the fusion width direction and the center line of the weak portion 222 along the fusion width direction is 3 mm to 5 mm. Figure 12

[0099] ​​Exemplarily, L3 can be 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm.

[0100] Since the welding portion 300 is arranged around the edge of the explosion-proof valve 220, if L3 is too large, the weak portion 222 is only located at the center of the explosion-proof valve 220, and there is a risk of insufficient pressure relief area when the battery cell is in thermal runaway, and the high-temperature gas in the battery cell is difficult to discharge in time; if L3 is too small, the weak portion 222 will be affected by welding heat and stress concentration when forming the welding portion 300, and then the weak portion 222 will be abnormal and unable to relieve pressure.

[0101] In order to avoid the above problems, L3 is limited to 3 mm to 5 mm in the embodiment, which can not only avoid the influence of welding heat and stress concentration on the weak portion 222, but also ensure that the explosion-proof valve 220 has a sufficient pressure relief area, so that the weak portion 222 can normally break and open when the battery cell is in thermal runaway, and relieve pressure in time, which helps to improve the safety performance of the battery cell.

[0102] As shown in FIG. 4, the reinforcing portion 400 is arranged on the welding portion 300, and the reinforcing portion 400 is arranged on the welding portion 300 in a manner of surrounding the welding portion 300. Figure 12 In some embodiments, the height H2 of the reinforcing portion 400 along the first direction is 0.8 mm to 1.5 mm.

[0103] Exemplarily, H2 can be 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm or 1.5 mm.

[0104] If H2 is too small, the reinforcing portion 400 may be welded through when forming the welding portion 300, which results in insufficient welding strength of the welding portion 300 and the risk of rupture and leakage; if H2 is too large, not only the overall weight and preparation cost of the battery cell will increase, but also the reinforcing portion 400 will occupy too much accommodation space 500, which will reduce the energy density of the battery cell.

[0105] In order to avoid the above problems, H2 is limited to 0.8 mm to 1.5 mm in the embodiment, which can not only ensure the welding quality of the welding portion 300 and reduce the risk of rupture and leakage of the welding portion 300, but also avoid the reinforcing portion 400 occupying too much accommodation space 500, which helps to ensure the energy density of the battery cell and also helps to reduce the overall weight and preparation cost of the battery cell.

[0106] As shown in FIG. 4, the reinforcing portion 400 is arranged on the welding portion 300, and the reinforcing portion 400 is arranged on the welding portion 300 in a manner of surrounding the welding portion 300. Figure 12 In some embodiments, the size L4 of the reinforcing portion 400 along the welding width direction is 2 mm to 3 mm.

[0107] Exemplarily, L4 can be 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm or 3 mm.

[0108] If L4 is too small, on the one hand, it is difficult to position the reinforcing portion 400, the edge of the mounting hole 110, and the edge of the explosion-proof valve 220, and on the other hand, the side wall of the reinforcing portion 400 may be welded through when the fusion portion 300 is formed, resulting in insufficient welding strength of the fusion portion 300 and a risk of rupture and leakage. If L4 is too large, not only will the overall weight and the preparation cost of the battery cell increase, but also the reinforcing portion 400 will occupy too much accommodation space 500, which will reduce the energy density of the battery cell.

[0109] To avoid the above problems, the embodiment limits L4 to 2 mm to 3 mm, that is, it can reduce the difficulty of positioning the reinforcing portion 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, can ensure the welding quality of the fusion portion 300, reduce the risk of rupture and leakage of the fusion portion 300, and also avoid the reinforcing portion 400 occupying too much accommodation space 500, which helps to ensure the energy density of the battery cell and reduce the overall weight and preparation cost of the battery cell.

[0110] For example, Figure 12 In some embodiments, the minimum distance L5 between the edge of the fusion portion 300 along the fusion width direction and the edge of the reinforcing portion 400 along the fusion width direction is 0.1 mm to 2 mm.

[0111] For example, the center line of the reinforcing portion 400 and the center line of the fusion portion 300 along the fusion width direction can be aligned or offset.

[0112] For example, the cross-sectional shape of the fusion portion 300 perpendicular to the extension direction can be U-shaped.

[0113] For example, L5 can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, or 2 mm.

[0114] If L5 is too small, the side wall of the reinforcing portion 400 may be welded through when the fusion portion 300 is formed, resulting in insufficient welding strength of the fusion portion 300 and a risk of rupture and leakage. If L5 is too large, the size of the reinforcing portion 400 along the fusion width direction needs to be set larger, which not only increases the overall weight and the preparation cost of the battery cell, but also causes the reinforcing portion 400 to occupy too much accommodation space 500, which reduces the energy density of the battery cell.

[0115] To avoid the above problems, the embodiment limits the L5 to 0.1mm to 2mm, that is, the welding quality of the fusion portion 300 can be ensured, the risk of the fusion portion 300 being cracked and leaking can be reduced, the reinforced portion 400 can be prevented from occupying too much accommodation space 500, the energy density of the battery cell can be ensured, and the overall weight and preparation cost of the battery cell can be reduced.

[0116] In some embodiments, the minimum distance between the surface of the substrate 100 away from the accommodation space 500 and the surface of the explosion-proof valve 220 away from the accommodation space 500 in the first direction (hereinafter referred to as the top height difference) is 0mm to 1mm.

[0117] For example, when the thickness of the substrate 100 is less than 1mm, the top height difference is not greater than the thickness of the substrate 100.

[0118] 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.

[0119] If the top height difference is too large, on the one hand, the appearance of the battery cell will be affected, and on the other hand, the uniformity of the fusion portion 300 will be adversely affected, which may cause the fusion portion 300 to be cracked, thereby reducing the welding strength and durability of the fusion portion 300 and affecting the welding quality.

[0120] To avoid the above problems, the embodiment limits the top height difference to 0mm to 1mm, which can ensure that the appearance of the battery cell is more beautiful, and can ensure the welding quality, welding strength and durability of the fusion portion 300, thereby avoiding the tearing of the fusion portion 300 and improving the safety and sealing of the battery cell.

[0121] Based on the same inventive concept, in combination with the description of the shell in the above various embodiments, the embodiment provides a battery cell having the corresponding technical effects of the shell of the above various embodiments, which will not be described here.

[0122] A battery cell includes a shell as described in the above various embodiments.

[0123] It should be noted that the above describes some embodiments of the present application. Other embodiments are within the scope of the appended claims.

[0124] Each of the embodiments in the present application is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be mutually referred to.

[0125] The description of the application is presented for purposes of illustration and description, and not by limitation. Numerous modifications and variations on the embodiments described herein will be apparent to those of ordinary skill in the art in light of the foregoing description. The embodiments described herein are chosen and described in order to best explain the principles of the application and its practical application to thereby enable others skilled in the art to best utilize the application. Various embodiments of the application are contemplated and can be made without departing from the spirit or scope of the application.

[0126] It should be understood that any of the above-described embodiments can be implemented in the form of control logic using hardware (e.g. an application specific integrated circuit or field programmable gate array) or a combination of hardware and software (e.g. software running on a processor or microprocessor). The software can be software instructions stored in memory and executed on a processor or a microprocessor.

[0127] Although the application has been described in conjunction with specific embodiments thereof, numerous alternatives, modifications, and variations will be readily apparent to those of ordinary skill in the art. Such alternatives, modifications, and variations are intended to fall within the ambit of the present application.

[0128] The embodiments of the application are intended to cover all such alternatives, modifications, and variations as falling within the scope of the application. Accordingly, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the application should be included in the protection scope of the application.

Claims

1. A casing, characterized in that, include: The substrate has a mounting surface, and an explosion-proof valve is provided on the mounting surface; The reinforcing part is connected to the mounting surface and / or the explosion-proof valve; Along the first direction, the orthographic projection of the reinforcing part on the mounting surface is defined as the reinforcing part projection, and the orthographic projection of the explosion-proof valve on the mounting surface is defined as the explosion-proof valve projection. The reinforcing part projection is located on at least one side of the explosion-proof valve projection. The first direction is the thickness direction of the substrate.

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 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 valve.

4. The outer casing according to claim 1, characterized in that, Along the first direction, the reinforcing part has a reinforcing protrusion away from the mounting surface, the explosion-proof valve has an explosion-proof protrusion away from the mounting surface, and 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 reinforcing part is integrally formed and connected to the substrate or the explosion-proof valve; or... The reinforcing 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 is integrally formed and connected to the substrate, and the explosion-proof valve includes a weak portion formed by etching; or, the explosion-proof valve is welded to the substrate, and the explosion-proof valve includes a weak portion formed by stamping.

7. 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 base plate has a through mounting hole, at least a portion of the explosion-proof valve is placed in the mounting hole, and the edge of the explosion-proof valve, the edge of the mounting hole, and the reinforcing part are welded together to form a welded part.

8. The outer casing according to claim 7, characterized in that, The thickness of the substrate is t, and 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 explosion-proof valve includes a weak section formed by stamping, and the distance L3 between the centerline of the welded portion along the weld width direction and the centerline of the weak section along the weld width direction is 3mm to 5mm; and / or, The height H2 of the reinforcing portion along the first direction is 0.8 mm to 1.5 mm; and / or, The dimension L4 of the reinforcing part along the weld width direction is 2mm to 3mm.

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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