Sealing metal sheet, battery monomer and battery

Abstract

The utility model provides a sealing metal sheet, a battery monomer and a battery, and relates to the technical field of batteries. The sealing metal sheet is used for sealing a liquid injection hole of a battery monomer, the sealing metal sheet comprises a body, the body is provided with a first surface which is configured to deviate from the interior of the battery monomer, and the first surface is provided with a sinking table. By arranging the sinking table, the molten metal material which does not flow into the space between the sealing metal sheet and the cover plate can be guided to flow into the sinking table, so that the molten metal material is prevented from being accumulated at the periphery of the sealing metal sheet, the surface flatness of the sealing metal sheet after welding can be improved, and the welding stress is reduced. Thus, the structural uniformity of the sealing metal sheet can be improved, the stress state of the sealing metal sheet can be improved, and finally the welding quality between the sealing metal sheet and the cover plate can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a sealing metal sheet, a battery cell and a battery. Background Art

[0002] A battery cell consists of a housing, a cover plate, and an electrode assembly. The cover plate and housing combine to define a chamber, within which the electrode assembly is positioned. A lower plastic component is positioned between the electrode assembly and the cover plate. After the battery cell is assembled, liquid is injected into the chamber through the injection hole provided in the cover plate. Once the battery cell is injected and formed, the injection hole is sealed and welded to the sealing metal sheet using sealing pins to ensure a tight seal.

[0003] Since the sealing metal sheet needs to be welded to the cover plate to seal the injection hole, the welding quality between the sealing metal sheet and the cover plate is directly related to the sealing performance of the battery cell. When welding the sealing metal sheet, it is necessary to first form a molten metal material between the sealing metal sheet and the cover plate to connect the sealing metal sheet and the cover plate. After the molten metal material cools and solidifies, the sealing metal sheet and the cover plate can be stably connected. However, the molten metal material accumulates at the periphery of the sealing metal sheet, and its flow direction is uncertain, which causes the surface of the sealing metal sheet to be uneven after the metal material solidifies, resulting in less uniform force on the sealing metal sheet, which has an adverse effect on the welding quality between the sealing metal sheet and the cover plate. Utility Model Content

[0004] The embodiments of the present application provide a sealing metal sheet, a battery cell, and a battery, which can improve the surface flatness of the sealing metal sheet after welding, thereby improving the welding quality between the sealing metal sheet and the cover plate.

[0005] In a first aspect, an embodiment of the present application provides a sealing metal sheet for sealing a liquid injection hole of a battery cell. The sealing metal sheet includes a body having a first surface configured to face away from the interior of the battery cell, and a sink is provided on the first surface.

[0006] In one embodiment, the sealing metal sheet has a peripheral sidewall for contacting the hole wall of the liquid injection hole. On the first surface side, there is a distance D1 between the peripheral sidewall and the periphery of the sink, which satisfies: 0.3mm≤D1≤0.8mm.

[0007] In one embodiment, along the axial direction of the main body, the sink has a depth dimension H1 that satisfies: 0.05 mm ≤ H1 ≤ 0.3 mm.

[0008] In one embodiment, along the axial direction of the body, the peripheral side wall of the sealing metal sheet includes a tapered surface, which is configured to fit against the hole wall of the injection hole, with the small diameter end of the tapered surface facing the interior of the battery cell.

[0009] In one embodiment, along the axial direction of the body, the peripheral side wall further includes a cylindrical surface, which is configured to be located on the side of the conical surface away from the interior of the battery cell. The cylindrical surface has an axial dimension H2 that satisfies: 0.05 mm ≤ H2 ≤ 0.2 mm.

[0010] In one embodiment, the body has a second surface configured to face the interior of the battery cell, and the second surface is provided with a relief groove configured to accommodate a head of a sealing nail of the battery cell.

[0011] In one embodiment, a reinforcing rib is provided at the angle between the groove bottom and the groove wall of the give way groove, one side of the reinforcing rib is connected to the groove bottom of the give way groove, and the other side is connected to the groove wall of the give way groove.

[0012] In one embodiment, the distance between the reinforcing rib and the center line of the relief groove gradually increases in a direction away from the first surface.

[0013] In one embodiment, the reinforcing rib extends in a ring shape along the circumference of the relief groove.

[0014] In one embodiment, the reinforcing rib is spaced apart from the second surface, and the distance between the reinforcing rib and the second surface gradually increases in a direction approaching the center of the clearance groove.

[0015] In one embodiment, along the axial direction of the main body, there is a distance H3 between the bottom of the clearance groove and the bottom of the sink, which satisfies: 0.3 mm ≤ H3 ≤ 0.5 mm.

[0016] In the second aspect, an embodiment of the present application provides a battery cell, which includes a shell, a cover plate, an electrode assembly, a sealing pin and the aforementioned sealing metal sheet; the shell has a accommodating cavity; the cover plate is provided with an injection hole, and the cover plate covers the shell; the electrode assembly is arranged in the accommodating cavity; the sealing pin is arranged in the injection hole; the sealing metal sheet is arranged at the end of the injection hole away from the accommodating cavity, and is sealed with the cover plate.

[0017] In a third aspect, an embodiment of the present application provides a battery comprising a plurality of the aforementioned battery cells.

[0018] Beneficial effects of the embodiments of the present application:

[0019] In the embodiments of the present application, by providing a sink, the flow of molten metal material that has not flowed between the sealing metal sheet and the cover plate can be guided into the sink, thereby preventing the molten metal material from accumulating at the periphery of the sealing metal sheet. This improves the surface flatness of the sealing metal sheet after welding and reduces welding stress. This improves the structural uniformity of the sealing metal sheet, thereby improving its stress state and ultimately improving the welding quality between the sealing metal sheet and the cover plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 is a schematic structural diagram of a sealing metal sheet provided in an embodiment of the present application;

[0022] Figure 2 is a schematic structural diagram of a longitudinal section of a sealing metal sheet provided in an embodiment of the present application;

[0023] Figure 3 yes Figure 2 Enlarged view of point A in the middle;

[0024] Figure 4 is a schematic structural diagram of a sealing metal sheet from another perspective provided by an embodiment of the present application;

[0025] Figure 5 is a schematic structural diagram of a battery cell provided in an embodiment of the present application;

[0026] Figure 6 Schematic diagram of the cooperation between the sealing metal sheet and the cover plate provided in an embodiment of the present application;

[0027] Figure 7 It is a schematic structural diagram of a battery provided in an embodiment of the present application.

[0028] Description of reference numerals:

[0029] 001-sealing metal sheet;

[0030] 011-body; 111-first surface; 112-sunk platform; 113-side wall; 114-cylindrical surface; 115-second surface; 116-relief groove; 117-reinforcement rib; 118-positioning hole;

[0031] 002-battery cell; 021-housing; 022-cover; 221-liquid injection hole; 023-electrode;

[0032] 003-battery; 031-box; 032-box cover. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0034] In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application and are not intended to limit the present application. The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0035] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0036] In the description of the embodiments of this application, words such as "example" or "for example" are used to indicate an example, illustration, or description. Any embodiment or design described as "for example" or "for example" in the embodiments of this application is not to be construed as being preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to clearly present relative concepts.

[0037] To facilitate understanding of the solution of the present application, the spline curves and arrows used in the drawings are explained here: the components indicated by the spline curves without arrows are solid components, that is, components with solid structures; the components indicated by the spline curves with arrows are virtual components, that is, components without solid structures.

[0038] See also Figure 1 , Figure 1 Figure 1 is a schematic diagram of the structure of a sealing metal sheet 001 provided in an embodiment of the present application. This embodiment of the present application provides a sealing metal sheet 001. Sealing metal sheet 001 is used to seal the liquid injection hole of a battery cell. Sealing metal sheet 001 includes a body 011. Body 011 has a first surface 111 configured to face away from the interior of the battery cell. A recessed platform 112 is provided on first surface 111.

[0039] It can be understood that the sealing metal sheet 001 is a circular sheet structure. Specifically, the sealing metal sheet 001 is an aluminum sheet.

[0040] The sink 112 is coaxially arranged with the sealing metal sheet 001 .

[0041] When sealing the battery cell's injection hole, place the sealing metal sheet 001 inside the injection hole, away from the interior of the battery cell. Welding material can be filled into the gap between the sealing metal sheet 001 and the cover plate 022, and heated using welding equipment to convert the material into molten metal. Part of the molten metal flows into the gap between the sealing metal sheet 001 and the cover plate 022, while the remaining part flows into the sink 112. After the molten metal cools and solidifies, the sealing metal sheet and the cover plate 022 are stably connected.

[0042] In this embodiment, by providing a sink 112, the flow of molten metal material that has not flowed between the sealing metal sheet 001 and the cover plate 022 can be guided to flow into the sink 112, thereby preventing the molten metal material from accumulating at the periphery of the sealing metal sheet 001. This can improve the surface flatness of the sealing metal sheet 001 after welding and reduce welding stress. In this way, the structural uniformity of the sealing metal sheet 001 can be improved, thereby improving its stress state, and ultimately improving the welding quality between the sealing metal sheet 001 and the cover plate 022.

[0043] Furthermore, by providing the sinking platform 112, a molten metal pool is formed on the sinking platform 112 when the molten metal material flows into the sinking platform 112. The presence of the molten pool can fully metallurgically bond the sealing metal sheet 001 and the cover plate 022, thereby improving the connection strength of the welding portion between the sealing metal sheet 001 and the cover plate 022.

[0044] At the same time, the formation of the molten pool helps to discharge the gas and impurities generated during the welding process, which can effectively reduce defects such as porosity and inclusions in the welding area.

[0045] Furthermore, by providing the sinking platform 112, when the sealing metal sheet 001 is welded to the top cover sheet, the constraint of the sealing metal sheet 001 on the weld can be reduced based on the provision of the sinking platform 112, allowing the weld to shrink freely. That is, the side of the outer ring of the sealing metal sheet 001 close to the first surface 111 can be deformed radially toward the sinking platform 112, so that the welding stress can be released through the sinking platform 112. In this way, the residual stress in the weld between the sealing metal sheet 001 and the top cover can be reduced, thereby improving the welding quality between the sealing metal sheet 001 and the cover plate 022.

[0046] See also Figure 2 and Figure 3 , Figure 2001 is a schematic structural diagram of a longitudinal section of a sealing metal sheet 001 provided in an embodiment of the present application. Figure 3 yes Figure 2 Enlarged view of point A in the middle. In one embodiment, the sealing metal sheet 001 has a peripheral sidewall 113 for contact with the wall of the injection hole. On the first surface 111 side, a distance D1 is defined between the peripheral sidewall 113 and the periphery of the sink 112, satisfying the following: 0.3 mm ≤ D1 ≤ 0.8 mm.

[0047] It can be understood that the distance D1 between the peripheral side wall 113 and the peripheral edge of the sink 112 includes but is not limited to: 0.3mm, 0.32mm, 0.35mm, 0.39mm, 0.4mm, 0.43mm, 0.48mm, 0.5mm, 0.53mm, 0.55mm, 0.58mm, 0.6mm, 0.65mm, 0.7mm, 0.72mm, 0.75mm, 0.78mm, and 0.8mm.

[0048] Furthermore, 0.45 mm ≤ D1 ≤ 0.5 mm.

[0049] In this embodiment, by limiting the distance between the peripheral side wall 113 and the peripheral edge of the sink 112, on the one hand, it can avoid the distance being too small, which leads to a low strength of the sealing metal sheet 001, thereby ensuring the strength of the fitting part between the sealing metal sheet 001 and the injection hole, and further ensuring the welding quality; on the other hand, it can avoid the distance being too large, which leads to the molten metal material that has not flowed into the space between the sealing metal sheet 001 and the cover plate 022 not being able to flow into the sink 112 in time, thereby improving the speed and stability of the molten pool forming.

[0050] See also Figure 3 In one embodiment, along the axial direction of the main body 011, the sink 112 has a depth dimension H1 that satisfies: 0.05mm≤H1≤0.3mm.

[0051] It can be understood that the depth dimension H1 of the sink 112 includes but is not limited to: 0.05mm, 0.08mm, 0.1mm, 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.29mm, and 0.3mm.

[0052] In the embodiment, by limiting the depth of the sink 112, on the one hand, it can be avoided that the depth is too small to form a molten pool, or cannot significantly reduce the constraint of the sealing metal sheet 001 on the weld, so that the molten pool can be formed stably and the weld can be easily contracted freely to reduce the residual stress of the weld between the sealing metal sheet 001 and the top cover; on the other hand, it can be avoided that the depth is too large to affect the strength of the sealing metal sheet 001, so that the sealing metal sheet 001 can meet the strength requirements of the pressure changes during the cyclic breathing of the battery cell, thereby ensuring its sealing strength.

[0053] See also Figure 2 In one embodiment, along the axial direction of the body 011, the peripheral side wall 113 of the sealing metal sheet 001 includes a tapered surface, which is configured to fit with the hole wall of the injection hole and make the small diameter end of the tapered surface face the interior of the battery cell.

[0054] It can be understood that the injection hole is a tapered hole, and the small diameter end of the tapered hole faces the inner wall of the battery cell.

[0055] In this embodiment, the above arrangement can not only achieve the matching of the sealing metal sheet 001 and the liquid injection hole to facilitate the subsequent welding operation, but also prevent the sealing metal sheet 001 from falling into the battery cell during welding.

[0056] See also Figure 3 In one embodiment, along the axial direction of the main body 011, the peripheral side wall 113 further includes a cylindrical surface 114. The cylindrical surface 114 is configured to be located on the side of the conical surface away from the interior of the battery cell. Along the axial direction of the main body 011, the cylindrical surface 114 has an axial dimension H2, satisfying: 0.05mm≤H2≤0.2mm.

[0057] It can be understood that the height dimensions of the cylindrical surface 114 include but are not limited to 0.05 mm, 0.06 mm, 0.08 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.19 mm, and 0.2 mm.

[0058] In this embodiment, the above-mentioned restrictions can reduce burrs at the sharp corners of the sealing metal sheet 001, thereby improving the appearance quality and surface finish of the sealing metal sheet 001. This can prevent impurities from being carried in the weld, and can also reduce pores and inclusion defects. This can improve the welding quality between the sealing metal sheet 001 and the top cover.

[0059] See also Figure 4 , Figure 4This is a schematic diagram of the structure of the sealing metal sheet 001 from another perspective, according to an embodiment of the present application. In one embodiment, the body 011 has a second surface 115 configured to face the interior of the battery cell. A clearance groove 116 is provided on the second surface 115. The clearance groove 116 is configured to accommodate the head of the sealing pin of the battery cell.

[0060] It's understandable that when sealing the injection hole, a sealing pin is first placed in the hole, and then the sealing metal sheet 001 is placed at the end of the injection hole away from the interior of the battery cell. Because the top cover (i.e., the lower plastic) is thin, while the sealing pin is long, there's a risk of the sealing pin being inserted upside down into the electrode assembly.

[0061] Based on this, in this embodiment, by providing a clearance groove 116, on the one hand, the sealing pin and the sealing metal sheet 001 can be partially overlapped, thereby effectively preventing the sealing pin from being driven too deep and inserting the electrode assembly upside down; on the other hand, the clearance groove 116 can also form a buffer space on the sealing metal sheet 001 to accommodate the expanded and deformed head of the sealing pin, preventing the sealing pin from directly abutting the sealing metal sheet 001, thereby improving the stress state of the sealing metal sheet 001. In this way, the connection strength between the sealing metal sheet 001 and the top cover can be guaranteed.

[0062] In which, along the axial direction of the sealing metal sheet 001 , the clearance groove 116 has a depth dimension H4 that satisfies: 0.3≤H4≤0.5mm.

[0063] See also Figure 3 In one embodiment, a reinforcing rib 117 is provided at the angle between the bottom of the give way groove 116 and the wall of the give way groove 116. One side of the reinforcing rib 117 is connected to the bottom of the give way groove 116, and the other side is connected to the wall of the give way groove 116.

[0064] It can be understood that the injection hole is a circular hole. Correspondingly, the sealing metal sheet 001 is a rotating body, and the center line of the clearance groove 116 is coaxially arranged with the axis of the injection hole.

[0065] In this embodiment, by providing reinforcing ribs 117, on the one hand, the structural strength of the sealing metal sheet 001 can be increased, thereby improving the connection strength between the sealing metal sheet 001 and the top cover; on the other hand, based on the improvement of the structural strength of the sealing metal sheet 001, a larger depth of the recess 116 can be provided to increase the space of the sealing metal sheet 001 for accommodating the sealing nails, thereby improving the reliability of the battery cell.

[0066] In one embodiment, the distance between the reinforcing rib 117 and the center line of the clearance groove 116 gradually increases in a direction away from the first surface 111 .

[0067] In this embodiment, by gradually increasing the distance between the reinforcing rib 117 and the center line of the giveway groove 116, the bottom of the giveway groove 116 can be smoothly transitioned to the groove wall of the giveway groove 116 through the reinforcing rib 117, so as to improve the stress concentration and thus enhance the structural reliability of the sealing metal sheet 001.

[0068] See also Figure 4 In one embodiment, the reinforcing rib 117 extends in a ring shape along the circumference of the clearance groove 116 .

[0069] In this embodiment, by setting the reinforcing rib 117 in a ring shape, the sealing metal sheet 001 can be structurally symmetrical, thereby improving its force symmetry and further enhancing its structural reliability.

[0070] See also Figure 3 In one embodiment, the reinforcing rib 117 is spaced apart from the second surface 115. The spacing between the reinforcing rib 117 and the second surface 115 gradually increases as it approaches the center of the clearance groove 116. This ensures that the opening size of the clearance groove 116 is suitable for sealing pins of various diameters, thereby improving the applicability of the sealing metal sheet 001.

[0071] See also Figure 3 In one embodiment, along the axial direction of the main body 011, there is a spacing H3 between the bottom of the groove 116 and the bottom of the sink 112, which satisfies: 0.3mm≤H3≤0.5mm.

[0072] It can be understood that the spacing between the bottom of the groove and the bottom of the sink 112 includes but is not limited to 0.3mm, 0.32mm, 0.35mm, 0.36mm, 0.37mm, 0.38mm, 0.39mm, 0.4mm, 0.43mm, 0.44mm, 0.45mm, 0.46mm, 0.47mm, 0.48mm, 0.49mm, and 0.5mm.

[0073] In this embodiment, through the above-mentioned limitation, on the one hand, the thickness dimension of this part can be guaranteed to meet the strength requirement of pressure change during the cycle breathing of the battery cell, thereby ensuring its sealing strength; on the other hand, it can avoid the thickness dimension of this part being too large to affect the setting of the sink 112 and the give way groove 116.

[0074] See also Figure 1 In one embodiment, a positioning hole 118 is provided at the bottom of the sink 112, and the positioning hole 118 is coaxially arranged with the sealing metal sheet 001. The positioning hole 118 facilitates the positioning of the sealing metal sheet 001, thereby improving the convenience of assembling the sealing metal sheet.

[0075] See also Figure 5 and Figure 6 , Figure 5 is a schematic structural diagram of a battery cell 002 provided in an embodiment of the present application, Figure 6 It is a schematic diagram of the cooperation between the sealing metal sheet 001 and the cover plate 022 provided in an embodiment of the present application. Accordingly, an embodiment of the present application provides a battery cell 002, which includes a shell 021, a cover plate 022, an electrode assembly, a sealing pin and the aforementioned sealing metal sheet. The shell 021 has a accommodating cavity. The cover plate 022 is provided with an injection hole 221. The cover plate 022 covers the shell 021. The electrode assembly is arranged in the accommodating cavity. The sealing pin is arranged in the injection hole 221. The sealing metal sheet 001 is arranged at the end of the injection hole 221 away from the accommodating cavity and is sealed with the cover plate 022.

[0076] Specifically, the battery cell 002 is a square-shell battery cell.

[0077] It can be understood that the battery cell 002 further includes a pole 023 provided on the cover plate 022 , and the electrode assembly is electrically connected to the pole 023 via the pole tab.

[0078] In this embodiment, the aforementioned sealing metal sheet 001 is used to guide the flow of molten metal material that has not flowed between the sealing metal sheet 001 and the cover plate 022 into the sink 112, thereby preventing the molten metal material from accumulating at the periphery of the sealing metal sheet 001. This also improves the surface flatness of the sealing metal sheet 001 after welding, reduces welding stress, and further improves the structural uniformity and stress state of the sealing metal sheet 001, thereby improving the welding quality between the sealing metal sheet 001 and the cover plate 022. Ultimately, the reliability of the battery cell 002 can be improved.

[0079] See also Figure 7 , Figure 7 003 is a schematic structural diagram of a battery 003 provided in an embodiment of the present application. Accordingly, an embodiment of the present application provides a battery 003, which includes a plurality of the aforementioned battery cells 002.

[0080] It is understood that the battery 003 may further include a box body 031 and a box cover 032, which together define an installation cavity. Multiple battery cells 002 are disposed in the installation cavity, and the multiple battery cells 002 are connected in series or in parallel, or some are connected in series and others in parallel.

[0081] In this embodiment, the aforementioned battery cell 002 is used to guide the flow of molten metal material that has not flowed between the sealing metal sheet 001 and the cover plate 022 into the sink 112, thereby preventing the molten metal material from accumulating at the periphery of the sealing metal sheet 001. This also improves the surface flatness of the sealing metal sheet 001 after welding, reduces welding stress, and further improves the structural uniformity and stress state of the sealing metal sheet 001, thereby improving the welding quality between the sealing metal sheet 001 and the cover plate 022. Ultimately, the reliability of the battery 003 can be improved.

[0082] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A sealing metal sheet for sealing the liquid injection hole of a battery cell, characterized in that: The sealing metal sheet includes a body having a first surface configured to face away from the interior of the battery cell, and the first surface is provided with a recessed platform.

2. The sealing metal sheet according to claim 1, characterized in that: The sealing metal sheet has a peripheral side wall for contacting the hole wall of the liquid injection hole. On the first surface side, there is a distance D1 between the peripheral side wall and the peripheral edge of the sink, which satisfies: 0.3mm≤D1≤0.8mm.

3. The sealing metal sheet according to claim 1, characterized in that: Along the axial direction of the main body, the sink has a depth dimension H1 that satisfies: 0.05mm≤H1≤0.3mm.

4. The sealing metal sheet according to claim 1, characterized in that Along the axial direction of the body, the peripheral side wall of the sealing metal sheet includes a tapered surface, which is configured to fit against the hole wall of the liquid injection hole, with the small diameter end of the tapered surface facing the interior of the battery cell.

5. The sealing metal sheet according to claim 4, characterized in that: Along the axial direction of the body, the peripheral side wall further includes a cylindrical surface, which is configured to be located on a side of the conical surface away from the interior of the battery cell. The cylindrical surface has an axial dimension H2 that satisfies: 0.05 mm ≤ H2 ≤ 0.2 mm.

6. The sealing metal sheet according to any one of claims 1 to 5, characterized in that: The body further has a second surface configured to face the interior of the battery cell, the second surface being provided with a relief groove configured to accommodate a head of a sealing nail of the battery cell.

7. The sealing metal sheet according to claim 6, characterized in that: A reinforcing rib is provided at the angle between the groove bottom of the give way groove and the groove wall of the give way groove, one side of the reinforcing rib is connected to the groove bottom of the give way groove, and the other side is connected to the groove wall of the give way groove.

8. The sealing metal sheet according to claim 7, characterized in that: In a direction away from the first surface, the distance between the reinforcing rib and the center line of the clearance groove gradually increases.

9. The sealing metal sheet according to claim 7, characterized in that: The reinforcing rib extends in a ring shape along the circumference of the clearance groove.

10. The sealing metal sheet according to claim 7 or 8, characterized in that: The reinforcing rib is spaced apart from the second surface, and the distance between the reinforcing rib and the second surface gradually increases in a direction approaching the center of the clearance groove.

11. The sealing metal sheet according to claim 6, characterized in that: Along the axial direction of the main body, there is a distance H3 between the bottom of the groove of the clearance groove and the bottom of the sink, which satisfies: 0.3mm≤H3≤0.5mm.

12. A battery cell, characterized in that: include: A housing having a receiving cavity; A cover plate is provided with a liquid injection hole, and the cover plate is covered with the shell; an electrode assembly, disposed in the accommodating cavity; A sealing pin, disposed in the liquid injection hole; And, the sealing metal sheet according to any one of claims 1 to 11 is arranged at an end of the liquid injection hole away from the accommodating cavity and is sealed to the cover plate.

13. A battery, characterized in that: The device comprises a plurality of battery cells as claimed in claim 12 .

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