Cover plate assembly of battery and battery monomer

Abstract

The utility model discloses a cover plate assembly of a battery and a single battery. The cover plate assembly of the battery comprises a cover body, the lower plastic is arranged on one side of the cover body in the thickness direction and stacked with the cover body; the pole is arranged on the cover body and the lower plastic in a penetrating manner; the connecting sheet is arranged on one side, far away from the cover body, of the lower plastic and is in welded connection with the post terminal, and two ends of the connecting sheet in the length direction are provided with bending parts which are bent towards the direction far away from the lower plastic. According to the cover plate assembly of the battery disclosed by the utility model, the pole group can be limited to move towards the lower plastic, the stability of the pole group is improved, and the moving distance generated when the pole group is subjected to thermal runaway is also reduced, so that safe structures such as an anti-explosion valve are prevented from being blocked, and the safety of the single battery is improved.

Description

Technical Field

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

[0002] In energy storage batteries, the cell capacity is high and the pole group is large. When the cell experiences thermal runaway, the lower plastic melts due to the temperature rise, and there is a large space for movement inside the cell. At this time, the cell produces a lot of gas at a fast speed, causing the pole group to shift inside the cell. If the pole group shifts toward the explosion-proof valve, the exhaust channel will be blocked, which will eventually lead to the inability to discharge the gas inside the cell in time, causing the shell to expand and burst. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a battery cover assembly, which improves the stability of the pole group and reduces the distance of movement of the pole group when thermal runaway occurs, thereby preventing the blockage of safety structures such as explosion-proof valves and improving the safety of battery cells.

[0004] The utility model also provides a battery monomer, comprising the battery cover assembly.

[0005] According to the embodiment of the utility model, the cover plate assembly of the battery includes: a cover body; a lower plastic, which is arranged on one side of the cover body in the thickness direction and is stacked with the cover body; a pole, which is passed through the cover body and the lower plastic; a connecting piece, which is arranged on a side of the lower plastic away from the cover body and is welded to the pole, and both ends of the connecting piece in the length direction have a bending portion bent in a direction away from the lower plastic.

[0006] According to the cover plate assembly of the battery of the embodiment of the utility model, a connecting piece is provided on the side of the lower plastic away from the cover body, and bent portions bent in a direction away from the lower plastic are provided at both ends of the connecting piece in the length direction, thereby limiting the movement of the electrode group in the direction of the lower plastic, thereby improving the stability of the electrode group and reducing the movement distance of the electrode group when thermal runaway occurs, thereby preventing the blockage of safety structures such as explosion-proof valves and improving the safety of the battery monomer.

[0007] In some embodiments of the present invention, the connecting piece has a hollow area, and the hollow area is located outside the welding area on the connecting piece welded to the pole.

[0008] In some embodiments of the present invention, the hollow areas are multiple and spaced apart.

[0009] In some embodiments of the present invention, the poles are two spaced apart along the length direction of the connecting piece, and the plurality of hollow areas include a first hollow area located between the two poles and a second hollow area and a third hollow area respectively located on one side of the two poles away from each other.

[0010] In some embodiments of the present invention, the second hollow area and the third hollow area extend to the bending portion on the same side respectively.

[0011] In some embodiments of the present invention, two ends of the lower plastic in the length direction of a side away from the cover body have protrusions, and the connecting piece is located between the two protrusions.

[0012] In some embodiments of the present invention, the cover plate assembly of the battery also includes: an end plate, which is arranged on the side of the lower plastic away from the cover body, and has a through hole that penetrates the end plate in the thickness direction of the end plate, and the connecting piece is arranged in the through hole.

[0013] In some embodiments of the present invention, an explosion-proof valve is provided on the cover body, and an avoidance hole opposite to the explosion-proof valve is provided on the lower plastic.

[0014] According to the battery cell of the embodiment of the utility model, it includes: a shell, at least one of the two opposite ends of the shell is open; the cover plate assembly of the above-mentioned battery, the cover plate assembly is provided at the open mouth of the shell; a pole group, the pole group is arranged in the shell, and the pole ear on the pole group is welded to the connecting piece.

[0015] According to the battery cell of the embodiment of the utility model, by setting the above-mentioned battery cover assembly, a connecting piece is set on the side of the lower plastic away from the cover body, and bent portions bent in the direction away from the lower plastic are set at both ends of the connecting piece in the length direction, so that the movement of the electrode group toward the lower plastic can be restricted, thereby improving the stability of the electrode group and reducing the movement distance of the electrode group when thermal runaway occurs, thereby preventing the blockage of safety structures such as explosion-proof valves and improving the safety of the battery cell.

[0016] In some embodiments of the present invention, the electrode group includes a stacked positive electrode sheet, a negative electrode sheet and a separator, and the stacking direction of the positive electrode sheet, the negative electrode sheet and the separator is perpendicular to the length direction of the connecting sheet; or, the electrode group includes a wound positive electrode sheet, a negative electrode sheet and a separator, and the winding axis of the positive electrode sheet, the negative electrode sheet and the separator is perpendicular to the thickness direction of the cover body.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 is a cross-sectional view of a battery cell according to an embodiment of the utility model;

[0020] Figure 2 is an exploded view of a cover plate assembly of a battery according to an embodiment of the utility model;

[0021] Figure 3 is a cross-sectional view of a cover plate assembly of a battery according to an embodiment of the utility model;

[0022] Figure 4 yes Figure 3 The enlarged view of point A in the middle;

[0023] Figure 5 is an exploded view of a cover plate assembly of a battery according to an embodiment of the utility model, wherein it is shown that no explosion-proof valve is provided;

[0024] Figure 6 is a cross-sectional view of a cover plate assembly of a battery according to an embodiment of the utility model, wherein no explosion-proof valve is provided;

[0025] Figure 7 yes Figure 6 The enlarged view of point B in the middle;

[0026] Figure 8 It is a stereoscopic view of a connecting piece of a cover assembly of a battery according to an embodiment of the utility model.

[0027] Reference numerals:

[0028] 100. Battery cell;

[0029] 10. Battery cover assembly;

[0030] 1. Cover body; 11. Explosion-proof valve;

[0031] 2. Lower plastic; 21. Protrusion; 22. Avoidance hole;

[0032] 3. Pole; 31. Sealing ring;

[0033] 4. Connecting piece; 41. Hollow area; 411. First hollow area; 412. Second hollow area; 413. Third hollow area; 42. Welding area; 43. Bending portion;

[0034] 5. End plate; 51. Through hole;

[0035] 6. Riveting block;

[0036] 7. Apply plastic;

[0037] 20. Shell;

[0038] 30. Pole group. DETAILED DESCRIPTION

[0039] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0040] In the description of the present utility model, it is necessary to understand that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] Reference below Figure 2-Figure 8 A cap plate assembly 10 of a battery according to an embodiment of the present invention is described.

[0043] like Figure 2 and Figure 5 As shown, the cover plate assembly 10 of the battery according to the embodiment of the utility model includes a cover body 1, a lower plastic 2, a pole 3 and a connecting piece 4.

[0044] Specifically, refer to Figure 3 , Figure 4 , Figure 6 and Figure 7 The lower plastic 2 is arranged on one side of the cover body 1 in the thickness direction and is stacked with the cover body 1. The pole 3 is passed through the cover body 1 and the lower plastic 2. The connecting piece 4 is arranged on the side of the lower plastic 2 away from the cover body 1 and is welded to the pole 3.

[0045] It can be understood that the cover body 1 has a high structural strength and is used to bear loads and collisions, so it is generally a metal part (a bare aluminum sheet) with conductivity. The lower plastic 2 is an insulating part. The lower plastic 2 is arranged between the cover body 1 and the pole group 30, and is used for insulation between the cover body 1 and the pole group 30 to avoid dangers such as short circuits. One end of the connecting piece 4 in the thickness direction is used to connect to the pole group 30, and the other end is used to connect to the pole 3. The other end of the pole 3 is connected to the riveting block 6, so as to realize the electrical connection between the pole group 30 and the external device, thereby supplying power to the external device. At the same time, a sealing ring 31 is provided on the pole 3, so as to realize insulation between the cover body 1 and the pole 3, and avoid dangers such as short circuits.

[0046] Furthermore, if Figure 8 As shown, both ends of the connecting piece 4 in the length direction have bent portions 43 bent in a direction away from the lower plastic 2, and the bent portions 43 abut against the electrode group 30, thereby limiting the movement of the electrode group 30 in the direction of the lower plastic 2. When the electrode group has thermal runaway, the lower plastic melts, and the electrode group moves in the direction of the lower plastic. However, since the connecting piece 4 is made of metal, it has good heat resistance and is not easy to melt. The bent portion 43 of the connecting piece 4 can abut against the electrode group 30, thereby still limiting the movement of the electrode group 30 in the direction of the lower plastic 2, thereby improving the stability of the electrode group 30 and reducing the distance of movement of the electrode group 30 when thermal runaway occurs, thereby preventing the explosion-proof valve 11 and other safety structures from being blocked, thereby improving the safety of the battery cell 100.

[0047] In addition, if Figure 2 and Figure 5 As shown, the cover assembly 10 of the battery also includes an upper plastic 7, which is located on the side of the cover body 1 away from the lower plastic 2, and the pole 3 is penetrated by the upper plastic 7. The side of the upper plastic 7 away from the cover body 1 has a mounting groove for mounting a rivet block 6, and the upper plastic 7 is used for insulation between the rivet block 6 and the cover body 1, so as to avoid the risk of short circuit or leakage.

[0048] According to the cover plate assembly 10 of the battery of the embodiment of the utility model, a connecting piece 4 is provided on the side of the lower plastic 2 away from the cover body 1, and bent portions 43 bent in a direction away from the lower plastic 2 are provided at both ends of the connecting piece 4 in the length direction, so that the movement of the electrode group 30 in the direction of the lower plastic 2 can be restricted, thereby improving the stability of the electrode group 30 and reducing the movement distance of the electrode group 30 when thermal runaway occurs, thereby preventing the explosion-proof valve 11 and other safety structures from being blocked, thereby improving the safety of the battery cell 100.

[0049] In some embodiments of the present invention, Figure 8 As shown, the connecting sheet 4 has a hollow area 41, and the hollow area 41 is located outside the welding area 42 on the connecting sheet 4 that is welded to the pole 3. It can be understood that the welding area 42 provided on the connecting sheet 4 needs to meet the area requirement for welding with the pole 3. Under this premise, the hollow area 41 is provided on the connecting sheet 4, which can reduce the weight of the connecting sheet 4, thereby reducing the weight of the battery cover assembly 10, and also reducing the cost of the battery cover assembly 10, thereby making the battery cell 100 lighter and reducing the manufacturing cost of the battery cell 100.

[0050] In some embodiments of the present invention, Figure 8 As shown, there are multiple hollow areas 41 spaced apart. Thus, the weight of the connecting sheet 4 can be further reduced, thereby reducing the weight of the battery cover assembly 10 and the cost of the battery cover assembly 10, thereby making the battery cell 100 lighter and reducing the manufacturing cost of the battery cell 100.

[0051] exist Figure 8 In the example shown, there are three hollow areas 41 spaced apart from each other, but the present invention is not limited thereto, and there may be more or less hollow areas 41 , such as 2, 4, 5 or 6.

[0052] In some embodiments of the present invention, Figure 8 , Figure 2 and Figure 5 As shown, there are two poles 3 spaced apart along the length direction of the connecting piece 4, and the plurality of hollow areas 41 include a first hollow area 411 located between the two poles 3 and a second hollow area 412 and a third hollow area 413 located respectively on the sides of the two poles 3 away from each other.

[0053] It can be understood that there are two poles 3 and two welding areas 42, and the welding areas 42 correspond to the poles 3 one by one. The first hollow area 411 is located between the two poles 3, and the second hollow area 412 and the third hollow area 413 are respectively located on the side of the two poles 3 away from each other, so that the first hollow area 411, the second hollow area 412 and the third hollow area 413 are spaced apart in the length direction of the connecting piece 4, so that the first hollow area 411, the second hollow area 412 and the third hollow area 413 are reasonably arranged in the length direction of the connecting piece 4, the structure of the connecting piece 4 is optimized, the weight is avoided from being too concentrated, and the weight distribution of the connecting piece 4 is even, thereby avoiding the collapse of the connecting piece 4 and improving the durability of the connecting piece 4.

[0054] In some embodiments of the present invention, Figure 8 As shown, the second hollow area 412 and the third hollow area 413 extend to the bent portion 43 on the same side, respectively. Thus, the weight of the bent portion 43 is reduced, so that the weight distribution of the connecting piece 4 is more uniform, and the weight is avoided from being concentrated on the bent portion 43, thereby avoiding the collapse of the connecting piece 4 and improving the durability of the connecting piece 4.

[0055] In some embodiments of the present invention, Figure 5-Figure 7 As shown, the lower plastic 2 has protrusions 21 at both ends of the length direction of the side away from the cover body 1, and the connecting piece 4 is located between the two protrusions 21. It can be understood that the ends of the two protrusions 21 away from the cover body 1 stop against the electrode group 30, thereby playing the role of supporting the electrode group 30, and forming a receiving space between the two protrusions 21. The connecting piece 4 is located between the two protrusions 21, that is, located in the receiving space, so that the structure of the battery cover assembly 10 is more compact and the volume of the battery cover assembly 10 is reduced.

[0056] At the same time, the accommodation space between the two protrusions 21 can provide a channel for the wiring of the electrode group 30 and provide installation space for various detection units, while also dissipating heat for the electrode group 30, reducing the thermal expansion coefficient of the battery cell 100 and reducing risks.

[0057] In some embodiments of the present invention, Figure 2-Figure 4 As shown, the battery cover assembly 10 also includes an end plate 5, which is arranged on the side of the lower plastic 2 away from the cover body 1, and has a through hole 51 that penetrates the end plate 5 in the thickness direction of the end plate 5, and the connecting piece 4 is arranged in the through hole 51.

[0058] It is understandable that the through hole 51 of the end plate 5 can provide a channel for the electrode group 30 to be routed and provide installation space for various detection units, while also dissipating heat for the electrode group 30, reducing the thermal expansion coefficient of the battery cell 100 and reducing risks. At the same time, the connecting piece 4 is arranged in the through hole 51, making the structure of the battery cover assembly 10 more compact and reducing the volume of the battery cover assembly 10.

[0059] In some embodiments of the present invention, Figure 2-Figure 4 As shown, the cover body 1 is provided with an explosion-proof valve 11, and the lower plastic 2 is provided with an avoidance hole 22 opposite to the explosion-proof valve 11. It can be understood that the explosion-proof valve 11 is a safety device for the battery cell 100. When thermal runaway occurs in the electrode group 30, the high-temperature gas generated in the electrode group 30 can be discharged to the outside through the explosion-proof valve 11, thereby avoiding explosion and improving the safety of the battery cell 100. The setting of the avoidance hole 22 can prevent the lower plastic 2 from blocking the explosion-proof valve 11, further improving the safety of the battery cell 100.

[0060] Reference below Figure 1 A battery cell 100 according to an embodiment of the present invention is described.

[0061] like Figure 1 As shown, the battery cell 100 according to the embodiment of the present invention includes a housing 20 , the above-mentioned battery cover assembly 10 and an electrode group 30 .

[0062] Specifically, refer to Figure 1 At least one of the two opposite ends of the shell 20 is open, that is, one of the two opposite ends of the shell 20 is open and the other end is closed, or both opposite ends of the shell 20 are open, and a cover plate assembly is provided at the open opening, and the electrode group 30 is provided in the shell 20. It can be understood that the electrode group 30 is an energy storage structure inside the battery cell 100, and the cover plate assembly and the shell 20 are used to protect the electrode group 30 so that the electrode group 30 is isolated from the external environment.

[0063] Furthermore, if Figure 2 , Figure 5 and Figure 8 As shown, the pole lug on the pole group 30 is welded to the connecting piece 4, the pole lug is welded to the welding area 42 of the connecting piece 4 facing the pole group 30, and the pole 3 is welded to the welding area 42 of the connecting piece 4 facing away from the pole group 30, so as to better facilitate the electrical connection between the pole 3 and the pole lug.

[0064] exist Figure 1 In the example shown, both opposite ends of the housing 20 are open, and cover plate assemblies are provided at the opposite openings of the housing 20. Figure 2 As shown, a cover plate assembly has an explosion-proof valve 11 and an end plate 5, as shown in FIG. Figure 5As shown, the other cover plate assembly is not provided with the explosion-proof valve 11 and the end plate 5.

[0065] According to the battery cell 100 of the embodiment of the utility model, by setting the above-mentioned battery cover assembly 10, a connecting piece 4 is set on the side of the lower plastic 2 away from the cover body 1, and bent portions 43 bent in the direction away from the lower plastic 2 are set at both ends in the length direction of the connecting piece 4, so that the movement of the electrode group 30 toward the lower plastic 2 can be restricted, thereby improving the stability of the electrode group 30 and reducing the movement distance of the electrode group 30 when thermal runaway occurs, thereby preventing the explosion-proof valve 11 and other safety structures from being blocked, thereby improving the safety of the battery cell 100.

[0066] In some embodiments of the present invention, the electrode group 30 includes a stacked positive electrode sheet, a negative electrode sheet and a separator, and the stacking direction of the positive electrode sheet, the negative electrode sheet and the separator is perpendicular to the length direction of the connecting sheet 4. It can be understood that the positive electrode sheet corresponds to the positive electrode ear, and the negative electrode sheet corresponds to the negative electrode ear. Figure 2 , Figure 5 and Figure 8 As shown, when the pole 3 is two poles spaced apart along the length direction of the connecting piece 4, the positive pole ear and the negative pole ear are respectively welded to the two welding areas 42 of the connecting piece 4, so as to realize the connection between the connecting piece 4 and the positive pole sheet and the negative pole sheet. A diaphragm is provided between the positive pole sheet and the negative pole sheet to prevent the positive pole sheet and the negative pole sheet from directly contacting each other and causing a short circuit, so that the pole group 30 can work normally.

[0067] Since the positive electrode sheet, the negative electrode sheet and the diaphragm are stacked, there is a gap between the positive electrode sheet and the diaphragm, and there is also a gap between the negative electrode sheet and the diaphragm. The stacking direction of the positive electrode sheet, the negative electrode sheet and the diaphragm is perpendicular to the length direction of the connecting sheet 4. This can prevent the bent portion 43 of the connecting sheet 4 from extending into the gap between the positive electrode sheet and the diaphragm or the negative electrode sheet and the diaphragm when it contacts the electrode group 30, thereby improving the effect of the connecting sheet 4 in fixing the electrode group 30, thereby further improving the stability of the electrode group 30, and further improving the safety of the battery cell 100.

[0068] Further, the electrode group 30 includes a positive electrode sheet, a negative electrode sheet and a separator that are wound, and the winding axes of the positive electrode sheet, the negative electrode sheet and the separator are perpendicular to the thickness direction of the cover body 1. Since the positive electrode sheet, the negative electrode sheet and the separator are wound, there is a gap between the positive electrode sheet and the separator, and there is also a gap between the negative electrode sheet and the separator, and the winding axes of the positive electrode sheet, the negative electrode sheet and the separator are perpendicular to the thickness direction of the cover body 1, it can be avoided that the bent portion 43 of the connecting sheet 4 extends into the gap between the positive electrode sheet and the separator or the negative electrode sheet and the separator when contacting the electrode group 30, thereby improving the effect of the connecting sheet 4 fixing the electrode group 30, thereby further improving the stability of the electrode group 30, and further improving the safety of the battery cell 100.

[0069] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0070] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery cover assembly, characterized in that: include: Cover body; A lower plastic, the lower plastic is arranged on one side of the cover body in the thickness direction and is stacked with the cover body; A pole, the pole is passed through the cover body and the lower plastic; A connecting piece, the connecting piece is arranged on a side of the lower plastic away from the cover body and is welded to the pole, both ends of the connecting piece in the length direction have bent portions bent in a direction away from the lower plastic, and the connecting piece has a hollow area, and the hollow area is located outside the welding area on the connecting piece welded to the pole.

2. The battery cover assembly according to claim 1, characterized in that: The hollow areas are multiple and spaced apart.

3. The battery cover assembly according to claim 2, characterized in that: The poles are two and spaced apart along the length direction of the connecting piece, and the plurality of hollow areas include a first hollow area located between the two poles and a second hollow area and a third hollow area respectively located on one side of the two poles away from each other.

4. The battery cover assembly according to claim 3, characterized in that: The second hollow area and the third hollow area extend to the bending portion on the same side respectively.

5. The battery cover assembly according to claim 1, characterized in that: The lower plastic has protrusions at both ends of the length direction of one side away from the cover body, and the connecting piece is located between the two protrusions.

6. The battery cover assembly according to claim 1, characterized in that: Also includes: The end plate is arranged on a side of the lower plastic away from the cover body, and has a through hole penetrating the end plate in the thickness direction of the end plate, and the connecting piece is arranged in the through hole.

7. The battery cover assembly according to claim 1, characterized in that: The cover body is provided with an explosion-proof valve, and the lower plastic is provided with an avoidance hole opposite to the explosion-proof valve.

8. A battery cell, characterized in that: include: a shell, at least one of two opposite ends of the shell being open; The cover plate assembly of the battery according to any one of claims 1 to 7, wherein the cover plate assembly is provided at the open opening of the shell; The pole group is arranged in the shell, and the pole ears on the pole group are welded to the connecting sheet.

9. The battery cell according to claim 8, characterized in that: The electrode group comprises a positive electrode sheet, a negative electrode sheet and a separator which are stacked, and the stacking direction of the positive electrode sheet, the negative electrode sheet and the separator is perpendicular to the length direction of the connecting sheet; Alternatively, the electrode group includes a positive electrode sheet, a negative electrode sheet and a separator that are wound, and the winding axis of the positive electrode sheet, the negative electrode sheet and the separator is perpendicular to the thickness direction of the cover body.

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