Top cover assembly, battery cell monomer, battery and electric equipment

Abstract

The utility model relates to the technical field of batteries, in particular to a top cover assembly, a battery cell monomer, a battery and electric equipment. The top cover assembly comprises a cover plate, an adapter plate and a pole, and a through hole is formed in the cover plate in the thickness direction. A welding hole is formed in the adapter piece in a penetrating mode, and the inner side face of the welding hole expands outwards in the direction towards the cover plate. The pole comprises a main body part and a conical part; the main body part penetrates through the through hole; the top end of the main body part protrudes out of the outer surface of the cover plate; the bottom end of the main body part is connected with the conical part, the conical part penetrates through the welding hole, and the circumferential side face of the conical part is attached to and welded to the inner side face of the welding hole. The battery cell monomer, the battery and the electric equipment comprise the top cover assembly, the circumferential side face of the conical part of the pole is attached to and welded to the inner side face of the welding hole of the switching piece, so that welding of the conical part and the welding area of the welding hole is facilitated, the welding area is increased, pseudo soldering is avoided, the welding quality is improved, and the internal resistance of the top cover assembly is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a top cover assembly, a battery cell, a battery and electrical equipment. Background Art

[0002] A battery cell usually includes a top cover assembly, a shell and an electrode assembly. The electrode assembly is installed in the shell, the top cover assembly is installed at the top opening of the shell, and the poles in the top cover assembly are electrically connected to the electrode assembly through adapters so that the electrical energy of the electrode assembly can be led out to the outside of the shell through the poles on the top cover assembly.

[0003] At present, in order to improve the assembly efficiency of battery cells, the cover plate, pole and adapter are usually assembled into an integral part. The pole is inserted into the cover plate and abuts against the adapter. Then the contact part (i.e., welding area) of the pole and the adapter is connected by laser welding. Due to the processing technology of the pole and the adapter, there is a gap in the contact part between the pole and the adapter, which reduces the welding area and quality of the pole and the adapter, and at the same time leads to a large internal resistance after the adapter and the pole are welded. Utility Model Content

[0004] The utility model aims to provide a top cover assembly, a battery cell, a battery and an electrical device, so as to improve the welding quality between the pole and the adapter and reduce the internal resistance between the pole and the adapter.

[0005] To achieve this purpose, the technical solution adopted by the utility model is:

[0006] Top cover assembly, including:

[0007] A cover plate, wherein the cover plate is provided with through holes along a thickness direction;

[0008] The adapter plate is provided with a welding hole;

[0009] The pole comprises a main body and a tapered portion, wherein the main body passes through the through hole and the top end of the main body protrudes from the outer surface of the cover plate; the bottom end of the main body is connected to the tapered portion, the tapered portion passes through the welding hole, and the circumferential side surface of the tapered portion is attached to and welded to the inner side surface of the welding hole.

[0010] As a preferred solution of the top cover assembly, the welding hole is a tapered hole, the large hole end of the tapered hole faces the cover plate, and the tapered portion is a conical structure matched with the tapered hole.

[0011] As a preferred solution of the top cover assembly, the taper angle of the welding hole is 130° to 140°.

[0012] As a preferred solution of the top cover assembly, the end surface of the tapered portion away from the main body portion is a horizontal end surface, so that the conical structure is in the shape of a truncated cone.

[0013] As a preferred solution of the top cover assembly, one side of the adapter sheet along the thickness direction is adhered to and welded to the bottom end of the main body.

[0014] As a preferred solution of the top cover assembly, the bottom end of the main body is coplanar with the inner side surface of the cover plate, so that one side of the adapter plate along the thickness direction is also attached to the inner side surface of the cover plate.

[0015] As a preferred solution of the top cover assembly, the main body is a stepped shaft, one end of the stepped shaft passes through the through hole and protrudes from the outer surface of the cover plate, the other end of the stepped shaft is connected to the conical portion, and the through hole is a stepped hole adapted to the stepped shaft.

[0016] The battery cell comprises a shell, an electrode assembly and the above-mentioned top cover assembly, wherein the electrode assembly is installed in the shell, the top cover assembly is installed at the top opening of the shell, and the adapter in the top cover assembly is electrically connected to the electrode assembly.

[0017] A battery comprises the above-mentioned battery cell.

[0018] Electrical equipment, including the above-mentioned battery.

[0019] The beneficial effects of the utility model are:

[0020] The top cover assembly proposed by the utility model is provided with a welding hole on the adapter plate, and the pole has a conical portion adapted to the welding hole, and the circumferential side surface of the conical portion is attached to and welded with the inner side surface of the welding hole, so that the laser can directly hit the welding area where the pole and the adapter plate are attached during the laser welding process, thereby increasing the welding area and generating a wider molten pool between the conical portion and the welding hole, avoiding the occurrence of cold welding, improving the welding quality, and reducing the internal resistance between the pole and the adapter plate.

[0021] The battery cell proposed in the utility model includes the above-mentioned top cover assembly. A welding hole is set on the adapter plate, and the pole has a conical portion adapted to the welding hole, and the circumferential side surface of the conical portion is attached and welded to the inner side surface of the welding hole, thereby improving the welding quality of the battery cell and reducing the internal resistance of the battery cell.

[0022] The battery proposed by the utility model includes the above-mentioned battery cell. A welding hole is set on the adapter plate, and the pole has a conical portion adapted to the welding hole, and the circumferential side surface of the conical portion is attached and welded to the inner side surface of the welding hole, thereby improving the welding quality of the battery and reducing the internal resistance of the battery.

[0023] The electrical equipment proposed by the utility model includes the above-mentioned battery. By arranging a welding hole on the adapter plate, the pole has a conical portion adapted to the welding hole, and the circumferential side surface of the conical portion is affixed and welded to the inner side surface of the welding hole, thereby improving the welding quality of the battery and reducing the internal resistance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is an exploded view of the assembly of the cover plate and the adapter plate provided in the embodiment of the utility model;

[0025] Figure 2 It is a structural schematic diagram of a first top cover assembly provided by an embodiment of the utility model;

[0026] Figure 3 It is a schematic diagram of the structural decomposition of the first top cover assembly provided by the embodiment of the utility model;

[0027] Figure 4 It is a structural schematic diagram of a second top cover assembly provided in an embodiment of the utility model.

[0028] The names and numbers of the components in the figure are as follows:

[0029] 1. Cover plate; 10. Through hole; 11. Cover plate; 111. First hole; 112. Liquid injection hole; 113. Explosion-proof hole; 12. Upper insulating member; 13. Lower insulating member; 131. Second hole; 132. Liquid leakage hole; 14. Sealing ring; 15. Explosion-proof plate; 16. Protective plate; 17. Conductive block; 18. Ceramic column;

[0030] 2. Adapter; 21. Welding hole;

[0031] 3. Pole; 31. Main body; 311. First part; 312. Second part; 313. Third part; 32. Conical part; 321. Horizontal end face. DETAILED DESCRIPTION

[0032] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the present invention are further described below in conjunction with the accompanying drawings and through specific implementation methods. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all of them.

[0033] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] In the description of this embodiment, the terms "upper", "lower", "right", "left" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0036] The technical solution of the utility model is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0037] This embodiment provides a battery cell, which includes a top cover assembly, an electrode assembly and a shell, wherein the shell has a top opening, the electrode assembly is installed in the shell through the top opening, and the top cover assembly is installed in the top opening of the shell to seal the electrode assembly in the shell.

[0038] Specifically, the shell may be a hexahedron or other shapes, and a receiving cavity is formed inside the shell to receive the electrode assembly and the electrolyte. A plurality of stacked electrode assemblies may be installed in the receiving cavity. The shell may be made of a metal material, such as aluminum or an aluminum alloy. When the shell is a metal shell, an insulating film is provided inside the shell. Of course, the shell may also be made of an insulating material, such as plastic.

[0039] The electrode assembly includes an electrode unit and a tab. The tab can be arranged at the two ends of the electrode unit or at intervals on the top of the electrode unit. The electrode unit includes a positive electrode sheet, a negative electrode sheet and a separator. The separator is located between adjacent positive and negative electrode sheets and is used to insulate and separate the positive and negative electrode sheets to prevent short circuits between the positive and negative electrode sheets.

[0040] In one optional embodiment, the positive electrode sheet, the separator and the negative electrode sheet are stacked and wound in sequence to form a wound electrode unit. In another optional embodiment, the positive electrode sheet, the separator and the negative electrode sheet are stacked in sequence to form a laminated electrode unit. At the same time, both the laminated electrode unit and the laminated electrode unit have gaps to facilitate the electrolyte to enter the electrode unit through the gaps, thereby infiltrating the positive electrode sheet and the negative electrode sheet. Specifically, the positive electrode sheet includes a positive electrode collector (such as aluminum foil) and a positive electrode active material layer (such as ternary material, lithium iron phosphate or lithium cobalt oxide) coated on the surface of the positive electrode collector. The negative electrode sheet includes a negative electrode collector (such as copper foil) and a negative electrode active material layer (such as graphite, carbon or silicon) coated on the surface of the negative electrode collector. The positive electrode tab is connected to the positive electrode sheet and extends from the electrode unit, and the positive electrode tab can be directly cut from the positive electrode collector. The negative electrode tab is connected to the negative electrode plate and extends out from the electrode unit, and the negative electrode tab can be directly formed by cutting the negative electrode current collector.

[0041] like Figure 1 and Figure 2 As shown, this embodiment also proposes a top cover assembly, which includes a cover plate 1, an adapter plate 2 and a pole 3. In order to improve the assembly efficiency of the battery cell, the cover plate 1, the pole 3 and the adapter plate 2 are usually assembled into an integral part. The pole 3 is inserted into the cover plate 1 and abuts against the adapter plate 2, and then the contact part (i.e., the welding area) of the pole 3 and the adapter plate 2 is connected by laser welding.

[0042] Specifically, the cover plate 1 includes a cover plate sheet 11, an upper insulating member 12, a lower insulating member 13, an explosion-proof plate 15, a protective plate 16 and a conductive block 17. Two upper insulating members 12 are stacked at both ends of the cover plate sheet 11 in the length direction, and a lower insulating member 13 is stacked below the cover plate sheet 11. The upper insulating member 12 and the lower insulating member 13 are both plastic parts to achieve a good insulation effect. A conductive block 17 is stacked above each upper insulating member 12, and the conductive block 17 and the corresponding upper insulating member 12 are fixedly mounted on the cover plate sheet 11 through a ceramic column 18. The two conductive blocks 17 are electrically connected to two poles 3 (a positive pole and a negative pole) respectively. An explosion-proof hole 113 and a liquid injection hole 112 are provided on the cover plate sheet 11. An explosion-proof plate 15 is installed in the explosion-proof hole 113, and a layer of protective plate 16 covers the top of the explosion-proof hole 113. When thermal runaway occurs in the shell and the internal pressure rises sharply, the high-temperature and high-pressure gas in the shell breaks through the explosion-proof plate 15 and the protective plate 16 to release the pressure in the shell, thereby improving the safety of the battery cell. The electrolyte is injected into the shell through the injection hole 112 on the cover plate 11, and the lower insulating member 13 is provided with a leakage hole 132. The electrolyte on the lower insulating member 13 can enter the shell through the leakage hole 132 to prevent the electrolyte from remaining on the lower insulating member 13.

[0043] Furthermore, two adapter plates 2 are installed below the lower insulating member 13 through a sealing ring 14, and the two poles 3 are respectively welded to the two adapter plates 2, and the two adapter plates 2 are respectively welded to the positive pole tab and the negative pole tab to achieve reliable electrical connection between the pole 3 and the tab. Since the top cover assembly is a prior art, the structure and assembly relationship of the top cover assembly will not be described in detail.

[0044] In the existing top cover assembly, due to the limitations of the processing technology of the pole and the adapter, there is a gap in the contact area between the pole and the adapter, which reduces the welding area and quality of the pole and the adapter, and at the same time causes a large internal resistance after the adapter and the pole are welded.

[0045] To solve the above problems, Figure 2 and Figure 3As shown, in the top cover assembly of the present embodiment, the cover plate 1 is provided with a through hole 10 along the thickness direction. The adapter plate 2 is provided with a welding hole 21, and the inner side surface of the welding hole 21 expands outwardly in the direction toward the cover plate 1. The pole 3 includes a main body 31 and a tapered portion 32, the main body 31 passes through the through hole 10, and the top end of the main body 31 protrudes from the outer surface of the cover plate 1. The bottom end of the main body 31 is connected to the tapered portion 32, the tapered portion 32 passes through the welding hole 21, and the circumferential side surface of the tapered portion 32 is affixed and welded to the inner side surface of the welding hole 21. By providing the welding hole 21 on the adapter plate 2, and at the same time the pole 3 has a tapered portion 32 adapted to the welding hole 21, and the circumferential side surface of the tapered portion 32 is affixed and welded to the inner side surface of the welding hole 21, so that the laser can directly hit the welding area ( Figure 2 The area corresponding to L in the figure increases the welding area to generate a wider molten pool between the tapered portion 32 and the welding hole 21, thereby avoiding the occurrence of cold welding, improving the welding quality, and reducing the internal resistance between the pole 3 and the adapter 2.

[0046] It should be noted that when laser welding is performed on the pole 3 and the adapter plate 2, a protective gas is usually blown into the welding area of ​​the pole 3 and the adapter plate 2 to prevent the welding area from reacting with the air to splash molten metal chips. This not only improves the welding quality, but also prevents metal chips from splashing into the shell, thereby improving the safety of the battery.

[0047] like Figure 2 and Figure 3 As shown, the welding hole 21 is a conical hole, the large hole end of the conical hole faces the cover plate 1, and the conical portion 32 is a conical structure adapted to the conical hole. By setting the bottom of the pole 3 extending into the shell into a conical structure, the welding hole 21 is correspondingly set as a conical hole, so that the outer peripheral surface of the conical portion 32 and the inner side surface of the welding hole 21 fit more closely, increasing the contact area between the pole 3 and the adapter 2, facilitating the generation of a wider molten pool during laser welding, and helping to improve the welding quality and reduce the internal resistance between the pole 3 and the adapter 2 after welding. In addition, the inner side surface of the welding hole 21 is an inclined surface, which has a good guiding effect on the installation of the conical portion 32 of the pole 3, facilitating the rapid assembly of the pole 3 and the adapter 2.

[0048] In an optional embodiment, the taper angle of the welding hole 21 is 130° to 140°. Figure 2 and Figure 3As shown, the taper angle α of the welding hole 21 can be 130°, 132°, 134°, 135°, 136°, 138° or 140°, etc., so that the tapered portion 32 has a suitable taper angle, ensuring that the circumferential side surface of the tapered portion 32 has a small slope, which is convenient for laser welding operation. When the taper angle α is too large, the length of the welding area L is long, which increases the welding time and reduces the welding efficiency; when the taper angle α is too small, the length of the welding area L is short, which reduces the contact area between the pole 3 and the adapter 2 and reduces the welding quality.

[0049] In an alternative embodiment, if Figure 2 and Figure 3 As shown, the conical portion 32 is a conical structure (i.e., a cone) with a conical tip. In another optional embodiment, as Figure 4 As shown, the end surface of the conical portion 32 away from the main body 31 is a horizontal end surface 321, so that the conical structure is truncated. By removing the tip of the conical portion 32, the length of the conical portion 32 extending into the shell is reduced, avoiding the pole 3 from occupying too much internal space of the shell, and improving the energy density of the battery cell.

[0050] Furthermore, one side of the adapter sheet 2 along the thickness direction is attached and welded to the bottom end of the main body 31, which increases the welding area between the pole 3 and the adapter sheet 2, improves the welding strength between the pole 3 and the adapter sheet 2, and enables the top cover assembly to pass a larger current. In this embodiment, the bottom end of the main body 31 is coplanar with the inner side surface of the cover plate 1, so that one side of the adapter sheet 2 along the thickness direction is also attached to the inner side surface of the cover plate 1, achieving stable installation of the adapter sheet 2 and improving the compactness of the top cover assembly.

[0051] like Figure 1 and Figure 2 As shown, the main body 31 is a stepped shaft, one end of the stepped shaft passes through the through hole 10 and protrudes from the outer surface of the cover plate 1, the other end of the stepped shaft is connected to the tapered portion 32, and the through hole 10 is a stepped hole adapted to the stepped shaft. By setting the main body 31 of the pole 3 as a stepped shaft and the through hole 10 as a stepped hole adapted to the stepped shaft, the through hole 10 plays a limiting role in the installation of the main body 31, thereby achieving stable installation of the cover plate 1 and the pole 3.

[0052] Specifically, the cover plate 11 is provided with a first hole 111, and the lower insulating member 13 is provided with a second hole 131. The first hole 111 and the second hole 131 have different inner diameters and are coaxially connected to form a through hole 10. The main body 31 includes a first part 311, a second part 312, and a third part 313 which are sequentially connected as a whole, and the axial diameters of the first part 311, the second part 312, and the third part 313 increase sequentially, so that the main body 31 is a stepped shaft. The first part 311 is inserted into the second hole 131, the second part 312 is inserted into the first hole 111, and the third part 313 protrudes from the upper surface of the cover plate 11 and can be welded to the corresponding conductive block 17.

[0053] The battery cell of the present embodiment includes the above-mentioned top cover assembly, and a welding hole 21 is provided on the adapter 2. At the same time, the pole 3 has a conical portion 32 adapted to the welding hole 21, and the circumferential side surface of the conical portion 32 is adhered to and welded to the inner side surface of the welding hole 21, thereby improving the welding quality of the battery cell and reducing the internal resistance of the battery cell.

[0054] This embodiment also proposes a battery, which includes the above-mentioned battery cell. By setting a welding hole 21 on the adapter 2, the pole 3 has a conical portion 32 adapted to the welding hole 21, and the circumferential side surface of the conical portion 32 is attached to and welded to the inner side surface of the welding hole 21, thereby improving the welding quality of the battery and reducing the internal resistance of the battery.

[0055] This embodiment also proposes an electrical device, which includes the above-mentioned battery. By setting a welding hole 21 on the adapter 2, and the pole 3 has a conical portion 32 adapted to the welding hole 21, and the circumferential side surface of the conical portion 32 is attached to and welded to the inner side surface of the welding hole 21, the welding quality of the battery is improved and the internal resistance of the battery is reduced.

[0056] The above embodiments are only to illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and modifications, which are within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A top cover assembly, characterized in that: include: A cover plate (1), wherein the cover plate (1) is provided with a through hole (10) along a thickness direction; The adapter plate (2) is provided with a welding hole (21) extending therethrough; A pole (3), the pole (3) comprising a main body (31) and a tapered portion (32), the main body (31) passing through the through hole (10) and the top end of the main body (31) protruding from the outer surface of the cover plate (1); the bottom end of the main body (31) is connected to the tapered portion (32), the tapered portion (32) passes through the welding hole (21), and the circumferential side surface of the tapered portion (32) is attached to and welded to the inner side surface of the welding hole (21).

2. The top cover assembly according to claim 1, characterized in that: The welding hole (21) is a conical hole, the large hole end of the conical hole faces the cover plate (1), and the conical portion (32) is a conical structure that matches the conical hole.

3. The top cover assembly according to claim 2, characterized in that: The taper angle of the welding hole (21) is 130° to 140°.

4. The top cover assembly according to claim 2, characterized in that: The end surface of the conical portion (32) away from the main body portion (31) is a horizontal end surface (321), so that the conical structure is in the shape of a truncated cone.

5. The top cover assembly according to claim 1, characterized in that: One side of the adapter sheet (2) along the thickness direction is adhered to and welded to the bottom end of the main body (31).

6. The top cover assembly according to claim 5, characterized in that: The bottom end of the main body (31) is coplanar with the inner side surface of the cover plate (1), so that one side of the adapter plate (2) along the thickness direction is also in contact with the inner side surface of the cover plate (1).

7. The top cover assembly according to claim 5, characterized in that: The main body (31) is a stepped shaft, one end of the stepped shaft passes through the through hole (10) and protrudes from the outer surface of the cover plate (1), the other end of the stepped shaft is connected to the conical portion (32), and the through hole (10) is a stepped hole adapted to the stepped shaft.

8. A battery cell, characterized in that: It comprises a shell, an electrode assembly and a top cover assembly as claimed in any one of claims 1 to 7, wherein the electrode assembly is installed in the shell, the top cover assembly is installed at the top opening of the shell, and the adapter (2) in the top cover assembly is electrically connected to the electrode assembly.

9. A battery, characterized in that Comprising the battery cell monomer as claimed in claim 8.

10. Electrical equipment, characterized in that: A battery comprising the battery of claim 9.

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