Sealing metal piece, battery cell and battery

Abstract

The present application relates to the technical field of batteries. Provided are a sealing metal piece, a battery cell and a battery. The sealing metal piece is configured to seal a liquid injection hole of a battery cell, and comprises a body, wherein the body has a first surface configured to face away from the interior of the battery cell, the first surface being provided with a recess.

Description

Sealing metal sheet, battery monomer and battery

[0001] The present application claims priority to the Chinese patent application No. 202422299997.7, filed on September 19, 2024, and entitled "Sealing metal sheet, battery monomer and battery", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a sealing metal sheet, a battery monomer and a battery. BACKGROUND

[0003] The battery monomer comprises a shell, a cover plate and an electrode assembly. The cover plate is covered with the shell to define a containing cavity. The electrode assembly is arranged in the containing cavity, and a lower plastic part is arranged between the electrode assembly and the cover plate. After the battery monomer is assembled, liquid needs to be injected into the containing cavity through the injection hole provided on the cover plate. After the battery monomer is injected, the injection hole needs to be sealed and welded by a sealing nail and a sealing metal sheet to ensure its sealing performance.

[0004] Since the sealing metal sheet needs to be welded on the cover plate to seal the injection hole, the welding quality between the sealing metal sheet and the cover plate directly relates to the sealing performance of the battery monomer. When the sealing metal sheet is welded, a molten metal material needs to be formed between the sealing metal sheet and the cover plate, so as to connect the sealing metal sheet and the cover plate. After the molten metal material is cooled and solidified, the sealing metal sheet and the cover plate can be stably connected. SUMMARY

[0005] The molten metal material is accumulated at the periphery of the sealing metal sheet, and its flow direction is uncertain, so that the surface of the sealing metal sheet is uneven after the metal material is solidified, which causes the sealing metal sheet to be not uniform in stress, and has an adverse effect on the welding quality between the sealing metal sheet and the cover plate.

[0006] In a first aspect, the present application provides a sealing metal sheet configured to seal an injection hole of a battery monomer. The sealing metal sheet comprises a body having a first surface configured to face away from the inside of the battery monomer, and the first surface is provided with a sink.

[0007] In a second aspect, the present application provides a battery monomer comprising a shell, a cover plate, an electrode assembly, a sealing nail and the aforementioned sealing metal sheet. The shell has a containing cavity. The cover plate is provided with an injection hole, and the cover plate is covered with the shell. The electrode assembly is arranged in the containing cavity. The sealing nail is arranged in the injection hole. The sealing metal sheet is arranged at one end of the injection hole away from the containing cavity, and is sealingly connected with the cover plate.

[0008] In a third aspect, the present application provides a battery comprising a plurality of the aforementioned battery monomers. Advantages

[0009] In the present application, by setting the sink, the flow of the molten metal material not flowing into the sealing metal sheet and the cover plate can be guided to flow into the sink, so as to avoid the molten metal material from accumulating at the periphery of the sealing metal sheet, thereby improving the flatness of the sealing metal sheet after welding and reducing the welding stress. In this way, the structural uniformity of the sealing metal sheet can be improved, thereby improving the stress state, and finally improving the welding quality between the sealing metal sheet and the cover plate. BRIEF DESCRIPTION OF DRAWINGS

[0010] Fig. 1 is a structural schematic diagram of a sealing metal sheet according to an embodiment of the present application;

[0011] Fig. 2 is a structural schematic diagram of a longitudinal section of a sealing metal sheet according to an embodiment of the present application;

[0012] Fig. 3 is an enlarged view of A in Fig. 2;

[0013] Fig. 4 is a structural schematic diagram of a sealing metal sheet from another perspective according to an embodiment of the present application;

[0014] Fig. 5 is a structural schematic diagram of a battery cell according to an embodiment of the present application;

[0015] Fig. 6 is a schematic diagram of a sealing metal sheet and a cover plate according to an embodiment of the present application;

[0016] Fig. 7 is a structural schematic diagram of a battery according to an embodiment of the present application.

[0017] Explanation of Reference Signs

[0018] 001 - sealing metal sheet;

[0019] 011 - body; 111 - first surface; 112 - sink; 113 - peripheral sidewall; 114 - cylindrical surface; 115 - second surface; 116 - accommodation groove; 117 - reinforcing rib; 118 - positioning hole;

[0020] 002 - battery cell; 021 - shell; 022 - cover plate; 221 - liquid injection hole; 023 - pole;

[0021] 003 - battery; 031 - box body; 032 - box cover. Embodiments of the present application

[0022] Please refer to FIG. 1, which is a structural schematic diagram of a sealing metal sheet 001 provided by an embodiment of the present application. The sealing metal sheet 001 is configured to seal a filling hole 221 of a battery monomer 002. The sealing metal sheet 001 comprises a body 011. The body 011 has a first surface 111 configured to face away from the inside of the battery monomer 002. The first surface 111 is provided with a sink 112.

[0023] 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.

[0024] The sink 112 is coaxially arranged with the sealing metal sheet 001.

[0025] When the filling hole 221 of the battery monomer 002 is sealed, the sealing metal sheet 001 is placed in the filling hole 221 and away from the inside of the battery monomer 002. A welding material can be filled in the fitting gap between the sealing metal sheet 001 and the cover plate 022, and the welding material is heated by a welding device to become a molten metal material. Part of the molten metal material flows to the gap between the sealing metal sheet 001 and the cover plate 022, and the other part flows to the sink 112. After the molten metal material cools and solidifies, the sealing metal sheet and the cover plate 022 are stably connected.

[0026] In the embodiment, by arranging the sink 112, the flow of the molten metal material that does not flow into the gap between the sealing metal sheet 001 and the cover plate 022 can be guided to flow into the sink 112, so as to avoid the molten metal material from accumulating at the periphery of the sealing metal sheet 001, thereby improving the surface flatness of the sealing metal sheet 001 after welding, and reducing the welding stress. In this way, the structural uniformity of the sealing metal sheet 001 can be improved, so as to improve the stress state thereof, and finally improve the welding quality between the sealing metal sheet 001 and the cover plate 022.

[0027] Moreover, by arranging the sink 112, when the molten metal material flows into the sink 112, the sink 112 forms a molten pool. The existence of the molten pool can make the sealing metal sheet 001 and the cover plate 022 be fully metallurgically combined, so as to improve the connection strength of the welding part between the sealing metal sheet 001 and the cover plate 022.

[0028] Meanwhile, the formation of the molten pool helps to discharge the gas and impurities generated in the welding process, and can effectively reduce the defects such as pores and inclusions at the welding part.

[0029] In addition, by arranging the sink 112, the restraint of the sealing metal sheet 001 on the weld can be reduced based on the arrangement of the sink 112 when the sealing metal sheet 001 is welded with the top cover sheet, so that the weld can freely shrink, that is, the side of the outer ring of the sealing metal sheet 001 close to the first surface 111 can be deformed radially to the sink 112, so that the welding stress can be released through the sink 112. In this way, the residual stress of the welding between the sealing metal sheet 001 and the top cover can be reduced, so that the welding quality between the sealing metal sheet 001 and the cover plate 022 can be improved.

[0030] Please refer to FIG. 2 and FIG. 3, FIG. 2 is a structure schematic diagram of the longitudinal section of the sealing metal sheet 001 provided by the embodiment of the present application, and FIG. 3 is an enlarged view of A in FIG. 2. In an embodiment, the sealing metal sheet 001 has a peripheral side wall 113 configured to be in contact with the hole wall of the liquid injection hole 221. On the side of the first surface 111, the peripheral side wall 113 has a spacing D1 with the peripheral edge of the sink 112, which satisfies: 0.3 mm≤D1≤0.8 mm.

[0031] It can be understood that the spacing D1 between the peripheral side wall 113 and the peripheral edge of the sink 112 includes but is not limited to: 0.3 mm, 0.32 mm, 0.35 mm, 0.39 mm, 0.4 mm, 0.43 mm, 0.48 mm, 0.5 mm, 0.53 mm, 0.55 mm, 0.58 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.72 mm, 0.75 mm, 0.78 mm, 0.8 mm.

[0032] Specifically, 0.45 mm≤D1≤0.5 mm.

[0033] In the embodiment, by limiting the spacing between the peripheral side wall 113 and the peripheral edge of the sink 112, on the one hand, the strength of the sealing metal sheet 001 can be prevented from being too small due to the too small spacing, so that the strength of the fitting part between the sealing metal sheet 001 and the liquid injection hole 221 can be ensured, and then the welding quality can be ensured; on the other hand, the molten metal material that does not flow between the sealing metal sheet 001 and the cover plate 022 can be timely flowed into the sink 112 due to the too large spacing, so that the rapidity and stability of the molten pool forming can be improved.

[0034] Please refer to FIG. 3, in an embodiment, along the axial direction of the body 011, the sink 112 has a depth dimension H1, which satisfies: 0.05 mm≤H1≤0.3 mm.

[0035] It can be understood that the depth dimension H1 of the sink 112 includes but is not limited to: 0.05 mm, 0.08 mm, 0.1 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm, 0.29 mm, 0.3 mm.

[0036] In an embodiment, by limiting the depth of the sink 112, on the one hand, the depth cannot be too small to form a molten pool, or cannot significantly reduce the constraint of the sealing metal sheet 001 on the weld, so as to both stably form a molten pool and facilitate the free shrinkage of the weld to reduce the residual stress of the welding between the sealing metal sheet 001 and the top cover; on the other hand, the depth cannot be too large to affect the strength of the sealing metal sheet 001, so that the sealing metal sheet 001 can meet the strength requirement of the pressure change in the cyclic breathing process of the battery monomer 002, thereby ensuring the sealing strength.

[0037] Please refer to FIG. 2, in an 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 be fitted with the hole wall of the liquid injection hole 221, and the small-diameter end of the tapered surface faces the inside of the battery monomer 002.

[0038] It can be understood that the liquid injection hole 221 is a tapered hole, and the small-diameter end of the tapered hole faces the inner wall of the battery monomer 002.

[0039] In the present embodiment, by the above arrangement, the cooperation of the sealing metal sheet 001 and the liquid injection hole 221 can be realized to facilitate subsequent welding operation; and the sealing metal sheet 001 can be prevented from falling into the inside of the battery monomer 002 during welding.

[0040] Please refer to FIG. 3, in an embodiment, along the axial direction of the body 011, the peripheral side wall 113 further includes a cylindrical surface 114, which is configured to be located on the side of the tapered surface away from the inside of the battery monomer 002, and the cylindrical surface 114 has an axial dimension H2, which satisfies: 0.05 mm≤H2≤0.2 mm.

[0041] It can be understood that the height dimension of the cylindrical surface 114 includes but is 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, 0.2 mm.

[0042] In the present embodiment, by the above limitation, the burr at the sharp corner of the sealing metal sheet 001 can be reduced, so as to improve the appearance quality and surface finish of the sealing metal sheet 001, thereby avoiding the inclusion of impurities in the weld, and also reducing the porosity and inclusion defects. In this way, the welding quality between the sealing metal sheet 001 and the top cover can be improved.

[0043] Please refer to FIG. 4, which is a structural schematic diagram of the sealing metal sheet 001 from another perspective according to an embodiment of the present application. In an embodiment, the body 011 has a second surface 115 configured to face the inside of the battery monomer 002. The second surface 115 is provided with a clearance slot 116. The clearance slot 116 is configured to accommodate the head of the sealing nail of the battery monomer 002.

[0044] It can be understood that when the liquid injection hole 221 is sealed, the sealing nail is first arranged in the liquid injection hole 221, and then the sealing metal sheet 001 is arranged at the end of the liquid injection hole 221 away from the inside of the battery monomer 002. Because the thickness of the top cover and the lower plastic is small, and the length of the sealing nail is large, there is a risk that the sealing nail will be inserted into the electrode assembly.

[0045] Based on this, in the present embodiment, by arranging the clearance slot 116, on the one hand, the sealing nail and the sealing metal sheet 001 can be partially overlapped, thereby effectively preventing the sealing nail from being inserted too deep and the electrode assembly from being inserted upside down; on the other hand, the clearance slot 116 can also form a buffer space on the sealing metal sheet 001 to accommodate the head of the sealing nail that expands and deforms, thereby avoiding the sealing nail directly abutting against the sealing metal sheet 001, so that the stress state of the sealing metal sheet 001 can be improved. In this way, the connection strength between the sealing metal sheet 001 and the top cover can be guaranteed.

[0046] Among them, along the axial direction of the sealing metal sheet 001, the clearance slot 116 has a depth dimension H4, which satisfies: 0.3≤H4≤0.5mm.

[0047] Please refer to FIG. 3, in an embodiment, a reinforcing rib 117 is arranged at the angle between the bottom of the clearance slot 116 and the wall of the clearance slot 116. One side of the reinforcing rib 117 is connected with the bottom of the clearance slot 116, and the other side is connected with the wall of the clearance slot 116.

[0048] It can be understood that the liquid injection hole 221 is a circular hole, and correspondingly, the sealing metal sheet 001 is a rotating body, and the center line of the clearance slot 116 is coaxially arranged with the axis of the liquid injection hole 221.

[0049] In the present embodiment, by arranging the reinforcing rib 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 clearance slot 116 with a larger depth dimension can be arranged to increase the space of the sealing metal sheet 001 configured to accommodate the sealing nail, thereby improving the reliability of the battery monomer 002.

[0050] In an embodiment, along the direction away from the first surface 111, the distance between the reinforcing rib 117 and the center line of the clearance slot 116 gradually increases.

[0051] In the embodiment, by setting the gradually increasing distance between the reinforcing rib 117 and the center line of the allowance slot 116, the groove bottom of the allowance slot 116 can be smoothly transitioned from the reinforcing rib 117 to the groove wall of the allowance slot 116, so as to improve the stress concentration, thereby improving the structural reliability of the sealing metal sheet 001.

[0052] Referring to FIG. 4, in an embodiment, the reinforcing rib 117 extends along the circumference of the allowance slot 116 in a ring shape.

[0053] In the embodiment, by setting the reinforcing rib 117 in a ring shape, the structure of the sealing metal sheet 001 can be symmetrical, so as to improve the force symmetry, thereby improving the structural reliability.

[0054] Referring to FIG. 3, in an embodiment, the reinforcing rib 117 is arranged spaced apart from the second surface 115. In the direction close to the center of the allowance slot 116, the distance between the reinforcing rib 117 and the second surface 115 gradually increases. In this way, the size of the opening of the allowance slot 116 can be ensured to be suitable for sealing pins of various diameters, thereby improving the applicability of the sealing metal sheet 001.

[0055] Referring to FIG. 3, in an embodiment, along the axial direction of the body 011, the distance H3 between the groove bottom of the allowance slot 116 and the bottom of the sink 112 satisfies: 0.3mm≤H3≤0.5mm.

[0056] It can be understood that the distance between the groove bottom of the allowance slot 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, 0.5mm.

[0057] In the embodiment, by the above limitation, on the one hand, the thickness of the part can be ensured to meet the strength requirement of the pressure change in the circulation and breathing process of the battery monomer 002, thereby ensuring the sealing strength; on the other hand, the thickness of the part can be prevented from being too large to affect the arrangement of the sink 112 and the allowance slot 116.

[0058] Referring to FIG. 1, in an embodiment, a positioning hole 118 is arranged at the bottom of the sink 112, and the positioning hole 118 is coaxially arranged with the sealing metal sheet 001. By arranging the positioning hole 118, the sealing metal sheet 001 can be positioned, thereby improving the convenience of assembling the sealing metal sheet 001.

[0059] Please refer to FIG. 5 and FIG. 6, FIG. 5 is a structural schematic diagram of the battery monomer 002 provided by the embodiments of the present application, and FIG. 6 is a schematic diagram of the cooperation of the sealing metal sheet 001 and the cover plate 022 provided by the embodiments of the present application. Accordingly, the embodiments of the present application provide a battery monomer 002, which comprises a shell 021, a cover plate 022, an electrode assembly, a sealing nail, and the sealing metal sheet 001 provided by some embodiments of the present application. The shell 021 has a containing cavity. The cover plate 022 is provided with a liquid injection hole 221. The cover plate 022 is covered with the shell 021. The electrode assembly is arranged in the containing cavity. The sealing nail is arranged in the liquid injection hole 221. The sealing metal sheet 001 is arranged at an end of the liquid injection hole 221 away from the containing cavity and is sealingly connected with the cover plate 022.

[0060] Specifically, the battery monomer 002 is a square cell battery monomer.

[0061] It can be understood that the battery monomer 002 further comprises a pole 023 arranged on the cover plate 022, and the electrode assembly is electrically connected with the pole 023 through a tab.

[0062] In the present embodiment, by adopting the aforementioned sealing metal sheet 001, not only can the flow of the molten metal material not flowing into the space between the sealing metal sheet 001 and the cover plate 022 be guided to flow into the sink 112, so as to avoid the molten metal material from accumulating at the periphery of the sealing metal sheet 001, but also the flatness of the surface of the sealing metal sheet 001 after welding can be improved, the welding stress can be reduced, and thus the structural uniformity and stress state of the sealing metal sheet 001 can be improved, so as to improve the welding quality between the sealing metal sheet 001 and the cover plate 022. Finally, the reliability of the battery monomer 002 can be improved.

[0063] Please refer to FIG. 7, which is a structural schematic diagram of the battery 003 provided by the embodiments of the present application. Accordingly, the embodiments of the present application provide a battery 003, which comprises a plurality of battery monomers 002 provided by some embodiments of the present application.

[0064] It can be understood that the battery 003 can further comprise a box 031 and a box cover 032, which are covered to define a mounting cavity. The plurality of battery monomers 002 are arranged in the mounting cavity, and the plurality of battery monomers 002 are connected in series or in parallel, or part of them are connected in series and part of them are connected in parallel.

[0065] In the present embodiment, by employing the aforementioned battery cell 002, not only can the flow of the molten metal material that does not flow between the sealing metal sheet 001 and the cover plate 022 be guided to flow into the sink 112, so as to avoid the molten metal material from accumulating at the periphery of the sealing metal sheet 001, but also the flatness of the surface of the sealing metal sheet 001 after welding can be improved, the welding stress can be reduced, and thus the structural uniformity and stress state of the sealing metal sheet 001 can be improved, so as to improve the welding quality between the sealing metal sheet 001 and the cover plate 022. Finally, the reliability of the battery 003 can be improved.

Claims

1. A sealing metal sheet (001) configured to seal a pouring hole (221) of a battery cell (002), the sealing metal sheet (001) comprising a body (011) having a first surface (111) configured to face away from an inside of the battery cell (002), the first surface (111) being provided with a sink (112).

2. The sealed metal sheet (001) according to claim 1, wherein, The sealing metal sheet (001) has a peripheral side wall (113) configured to be in contact with a hole wall of the pouring hole (221), and between the peripheral side wall (113) and a peripheral edge of the sink (112) on the side of the first surface (111), there is a spacing D1 satisfying 0.3 mm≤D1≤0.8 mm.

3. The sealed metal sheet (001) according to claim 1 or 2, wherein Along an axial direction of the body (011), the sink (112) has a depth dimension H1 satisfying 0.05 mm≤H1≤0.3 mm.

4. The sealed metal sheet (001) according to any one of claims 1-3, wherein, Along the axial direction of the body (011), the peripheral side wall (113) of the sealing metal sheet (001) comprises a tapered surface configured to be in abutment with the hole wall of the pouring hole (221) and to have a small-diameter end of the tapered surface facing the inside of the battery cell (002).

5. The sealed metal sheet (001) according to claim 4, wherein, Along the axial direction of the body (011), the peripheral side wall (113) further comprises a cylindrical surface (114) configured to be located on a side of the tapered surface away from the inside of the battery cell (002), the cylindrical surface (114) having an axial dimension H2 satisfying 0.05 mm≤H2≤0.2 mm.

6. The sealed metal sheet (001) according to any one of claims 1-5, wherein, The body (011) further has a second surface (115) configured to face the inside of the battery cell (002), the second surface (115) being provided with a clearance groove (116) configured to accommodate a head of a sealing pin of the battery cell (002).

7. The sealed metal sheet (001) according to claim 6, wherein, A reinforcing rib (117) is arranged at an angle between a groove bottom of the clearance groove (116) and a groove wall of the clearance groove (116), one side of the reinforcing rib (117) being connected to the groove bottom of the clearance groove (116) and the other side being connected to the groove wall of the clearance groove (116).

8. The sealed metal sheet (001) according to claim 7, wherein, Along a direction away from the first surface (111), a spacing between the reinforcing rib (117) and a center line of the clearance groove (116) gradually increases.

9. The sealed metal sheet (001) according to claim 7 or 8, wherein The reinforcing rib (117) extends in a ring shape along a circumferential direction of the clearance groove (116).

10. The sealed metal sheet (001) according to any one of claims 7-9, wherein, The reinforcing rib (117) is spaced apart from the second surface (115), and along a direction close to a center of the clearance groove (116), a spacing between the reinforcing rib (117) and the second surface (115) gradually increases.

11. The sealed metal sheet (001) according to any one of claims 6-10, wherein, Along the axial direction of the body (011), there is a spacing H3 between the groove bottom of the clearance groove (116) and a bottom of the sink (112), satisfying 0.3 mm≤H3≤0.5 mm. 12.A battery cell (002) comprising: a housing (021) having a receiving cavity; a cover plate (022) provided with a pouring hole (221), the cover plate (022) being covered with the housing (021) ; an electrode assembly disposed in the accommodation cavity; a sealing nail disposed in the liquid injection hole (221); and the sealing metal sheet (001) as claimed in any one of claims 1-11 is disposed at the end of the liquid injection hole (221) away from the accommodation cavity and is sealingly connected with the cover plate (022).

13. A battery (003) comprising a plurality of battery cells (002) as claimed in claim 12.

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