Cover plate assembly, battery monomer, battery module and battery pack

Abstract

The utility model belongs to the technical field of batteries, and discloses a cover plate assembly, a battery monomer, a battery module and a battery pack, the cover plate assembly comprises a cover plate body, a connecting sheet and a pole, one side of the connecting sheet deviating from the cover plate body is provided with a riveting groove, the groove bottom of the riveting groove is provided with a through hole, the pole comprises a pole body and a riveting part, the riveting part is arranged on the side wall of the column in a protruding mode and extends in the circumferential direction of the column to form a closed-loop structure, the column penetrates through the through hole and is in insulation connection with the cover plate body, the side wall of the column is attached to the hole wall of the through hole, the riveting part is matched with the riveting groove in shape, and the riveting part is embedded in the riveting groove; the surface of the side, deviating from the cover plate body, of the connecting piece, the surface of the side, deviating from the cover plate body, of the riveting part and the surface of the side, deviating from the cover plate body, of the column body are flush. According to the cover plate assembly, the contact area of the connecting piece and the pole can be enlarged, the connection reliability of the connecting piece and the pole is improved, the tab is prevented from being scratched, and the energy density of the single battery is improved.

Description

Technical Field

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

[0002] As lithium-ion battery technology matures, it is widely used as a power battery in electric vehicles. With the development of the industry, the requirements for battery fast-charging performance are becoming increasingly stringent, as are the requirements for lithium-ion battery's current capacity and safety capabilities. As the connecting structure between the upper and lower parts of the battery cell and a key current carrier in the battery, the design of the connector is of paramount importance. Therefore, special attention must be paid to the connector's high current capacity and reliability.

[0003] Currently, cylindrical battery connectors and terminals are fixedly connected by welding. The limited weld area results in a low current flow between the connector and the terminal. During rapid charging, this low current flow causes the battery cell to heat up rapidly, hindering long-term battery cycling and even leading to thermal runaway, reducing battery safety. Furthermore, when the battery vibrates, the connector and terminal are prone to desoldering, causing a short circuit.

[0004] Therefore, it is urgent to propose a cover plate assembly, a battery cell, a battery module and a battery pack to solve the above technical problems. Utility Model Content

[0005] The first object of the present utility model is to provide a cover plate assembly, which can expand the contact area between the connecting plate and the pole, improve the reliability of the connection between the connecting plate and the pole, prevent the pole ear from being scratched, and is conducive to improving the energy density of the battery cell.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] Cover assembly, including:

[0008] Cover plate body;

[0009] A connecting piece, wherein a rivet groove is provided on a side of the connecting piece facing away from the cover plate body, and a through hole is provided at the bottom of the rivet groove;

[0010] The pole includes a column and a riveted portion. The riveted portion is protruded from the side wall of the column and extends along the circumference of the column to form a closed loop structure. The column is passed through the through hole and is insulated and connected to the cover body. The side wall of the column fits with the hole wall of the through hole. The riveted portion is adapted to the shape of the rivet groove and is embedded in the rivet groove. The side surface of the connecting piece facing away from the cover body, the side surface of the rivet portion facing away from the cover body, and the side surface of the column facing away from the cover body are flush.

[0011] Optionally, the rivet groove and the riveted portion are made by a riveting process.

[0012] Optionally, the edge of the riveting groove is welded to the riveting portion; and / or the bottom of the riveting groove is welded to the riveting portion; and / or the edge of the through hole is welded to the column.

[0013] Optionally, the orthographic projection of the riveted portion on the cover plate body is a circle or a polygon.

[0014] Optionally, the bottom of the riveting groove is perpendicular to the axis of the column.

[0015] Optionally, the axis of the through hole is located at the center of the bottom of the rivet groove.

[0016] A second object of the present invention is to provide a battery cell having a longer service life, higher safety in use, lower risk of short circuit and higher energy density.

[0017] To achieve this purpose, the present invention adopts the following technical solutions:

[0018] The battery cell comprises a battery shell, a battery core and the above-mentioned cover plate assembly. The battery core and the connecting piece are both arranged in the battery shell, and the cover plate body is sealed at the opening of the battery shell.

[0019] Optionally, a tab is protruded from one side of the battery cell facing the cover body, and the connecting piece is fixedly connected to the tab.

[0020] A third object of the present invention is to provide a battery module having a longer service life, higher safety in use, lower risk of short circuit and higher energy density.

[0021] To achieve this purpose, the present invention adopts the following technical solutions:

[0022] The battery module includes a connecting bar and the above-mentioned battery cells, the number of the battery cells is at least two, and the at least two battery cells are conductively connected through the connecting bar.

[0023] The fourth object of the present invention is to provide a battery pack having a longer service life, higher safety in use, lower risk of short circuit and higher energy density.

[0024] To achieve this purpose, the present invention adopts the following technical solutions:

[0025] The battery pack comprises a battery box and the above-mentioned battery module, wherein the battery module is arranged in the battery box.

[0026] Beneficial effects of the utility model:

[0027] A rivet groove is provided on the side of the connecting piece facing away from the cover body, and a through hole is provided at the bottom of the rivet groove. The pole includes a column and a rivet portion. The rivet portion is protruded from the side wall of the column, and the rivet portion extends along the circumference of the column to form a closed loop structure. The column is passed through the through hole and is insulated and connected to the cover body. The side wall of the column fits with the hole wall of the through hole, the rivet portion is adapted to the shape of the rivet groove, and the rivet portion is embedded in the rivet groove. The structure in which the side wall of the column fits with the hole wall of the through hole and the rivet portion is embedded in the rivet groove expands the contact area between the pole and the connecting piece, thereby increasing the current flow between the pole and the connecting piece, reducing the probability of rapid heating of the battery cell when the battery cell is quickly charged, and has the effect of extending the service life of the battery cell and improving the safety of the battery cell.

[0028] Secondly, the rivet groove is opened on the side of the connecting piece away from the cover body. The structure in which the riveted part is embedded in the rivet groove improves the reliability of the connection between the pole and the connecting piece, reduces the probability of failure of the connection between the pole and the connecting piece, and thus can reduce the probability of short circuit problems in the battery cell.

[0029] Thirdly, the surface of the connecting piece facing away from the cover body, the surface of the riveted part facing away from the cover body, and the surface of the column facing away from the cover body are flush, which not only prevents the connecting piece, the riveted part and the column from scratching the tabs, thus ensuring the safety of the battery cell, but also reduces the overall weight of the cover assembly to a certain extent, which is beneficial to improving the energy density of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the assembly structure of the connecting piece and the pole provided in an embodiment of the present utility model;

[0031] Figure 2 yes Figure 1 Cross-sectional view in the AA direction;

[0032] Figure 3 This is a schematic diagram of the cross-sectional structure of the connecting piece provided by an embodiment of the present utility model;

[0033] Figure 4 It is a schematic diagram of the cross-sectional structure of the pole provided by an embodiment of the utility model.

[0034] In the picture:

[0035] 100, connecting piece; 110, rivet groove; 120, through hole; 200, pole; 210, column; 220, rivet portion. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0037] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0038] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0039] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0040] This embodiment provides a cover plate assembly, which can expand the contact area between the connecting piece and the pole, improve the reliability of the connection between the connecting piece and the pole, prevent the pole tab from being scratched, and is conducive to improving the energy density of the battery cell.

[0041] Specifically, if Figures 1 to 4As shown, the cover assembly includes a cover body (not shown in the figure), a connecting piece 100 and a pole 200, wherein a rivet groove 110 is provided on the side of the connecting piece 100 facing away from the cover body, and a through hole 120 is provided at the bottom of the rivet groove 110. The pole 200 includes a column 210 and a rivet portion 220. The rivet portion 220 is protruding from the side wall of the column 210, and the rivet portion 220 extends along the circumference of the column 210 to form a closed loop structure. The column 210 is passed through the through hole 120 and is insulated and connected to the cover body. The side wall of the column 210 is in contact with the hole wall of the through hole 120. The rivet portion 220 is adapted to the shape of the rivet groove 110 and is embedded in the rivet groove 110. The side surface of the connecting piece 100 facing away from the cover body, the side surface of the rivet portion 220 facing away from the cover body and the side surface of the column 210 facing away from the cover body are flush.

[0042] Based on the above design, a rivet groove 110 is provided on the side of the connecting piece 100 away from the cover body, and a through hole 120 is provided at the bottom of the rivet groove 110. The pole 200 includes a column 210 and a riveted portion 220. The riveted portion 220 is protruding from the side wall of the column 210, and the riveted portion 220 extends along the circumference of the column 210 to form a closed loop structure. The column 210 is passed through the through hole 120 and is insulated from the cover body. The side wall of the column 210 is in contact with the hole wall of the through hole 120, and the riveted portion 220 is in contact with the rivet groove 110. The shape of the column 200 is adapted, and the rivet portion 220 is embedded in the rivet groove 110. The structure in which the side wall of the column 210 fits the hole wall of the through hole 120 and the rivet portion 220 is embedded in the rivet groove 110 expands the contact area between the pole 200 and the connecting piece 100, thereby increasing the current flow between the pole 200 and the connecting piece 100, reducing the probability of rapid temperature rise of the battery cell when the battery cell is quickly charged, and having the effect of extending the service life of the battery cell and improving the safety of the battery cell.

[0043] Secondly, the rivet groove 110 is opened on the side of the connecting piece 100 away from the cover body, and the structure in which the rivet portion 220 is embedded in the rivet groove 110 improves the reliability of the connection between the pole 200 and the connecting piece 100, reduces the probability of failure of the connection between the pole 200 and the connecting piece 100, and thus can reduce the probability of short circuit problems in the battery cell.

[0044] Again, the connecting piece 100 and the battery cell are usually arranged in the battery shell of the battery cell, and the side of the connecting piece 100 facing away from the cover body is welded to the pole ear of the battery cell. In this embodiment, the side surface of the connecting piece 100 facing away from the cover body, the side surface of the rivet part 220 facing away from the cover body, and the side surface of the column 210 facing away from the cover body are flush with each other. This can prevent the connecting piece 100, the rivet part 220 and the column 210 from scratching the pole ear, provide a guarantee for the safety of the battery cell, and also reduce the overall weight of the cover assembly to a certain extent, which is conducive to improving the energy density of the battery cell.

[0045] Furthermore, the rivet groove 110 and the rivet portion 220 are made by a riveting process. In actual production, the column 210 is passed through the through hole 120 of the connecting piece 100, and then the side of the connecting piece 100 facing away from the cover body and the side of the column 210 facing away from the cover body are riveted to form a rivet groove 110 on the side of the connecting piece 100 facing away from the cover body, and a rivet portion 220 is formed on the side of the column 210 facing away from the cover body, and the rivet portion 220 is embedded in the rivet groove 110. The riveting process is a relatively common production process in this field. It is simple to operate, which is conducive to reducing production costs, and can form a reliable connection relationship between the pole 200 and the connecting piece 100, and increase the contact area between the pole 200 and the connecting piece 100.

[0046] Furthermore, after the pole 200 and the connecting piece 100 are riveted, the pole 200 and the connecting piece 100 are welded to further improve the reliability of the connection between the two. Secondly, the welding of the pole 200 and the connecting piece 100 further expands the connection area between the two, which has the effect of further increasing the current flow between the pole 200 and the connecting piece 100. Thirdly, the welding of the pole 200 and the connecting piece 100 can also achieve a seal between the pole 200 and the connecting piece 100, thereby preventing the electrolyte in the battery shell from overflowing through the gap between the pole 200 and the connecting piece 100.

[0047] Specifically, the edge of the rivet groove 110 may be welded to the rivet portion 220, and / or the bottom of the rivet groove 110 may be welded to the rivet portion 220, and / or the edge of the through hole 120 may be welded to the column 210. Furthermore, the welding process between the pole 200 and the connecting piece 100 may be laser welding, penetration welding, ultrasonic welding, or other commonly used welding processes in the art.

[0048] Optionally, the orthographic projection of the rivet portion 220 on the cover body is a circle or a polygon. When the orthographic projection of the rivet portion 220 on the cover body is a polygon, it can be a triangle, a quadrilateral or a pentagon, etc., which is not limited here.

[0049] Optionally, the bottom of the rivet groove 110 is perpendicular to the axis of the column 210 to ensure the verticality of the connecting piece 100 and the column 210. After the connecting piece 100 and the pole 200 are connected, the connecting piece 100 can be smoothly installed in the battery shell, which reduces the production difficulty and improves the production efficiency.

[0050] Optionally, the axis of the through hole 120 is located at the center of the bottom of the rivet groove 110, so along the circumference of the column 210, the size of the rivet portion 220 protruding from the side wall of the column 210 is equal, so that the overall structural consistency of the pole 200 is better, and the reliability and force uniformity of the riveting between the rivet portion 220 and the rivet groove 110 are improved.

[0051] Further, if Figures 1 to 4 As shown, the sum of the size of the rivet portion 220 protruding from the side wall of the column 210 and the radius of the column 210 is a, and the height of the column 210 is h, a≤h. If a is too large, the riveting process will be more difficult. Therefore, the design of a≤h in this embodiment can appropriately reduce the difficulty of riveting the pole 200 and the connecting piece 100, which has the effect of improving production efficiency and reducing production costs.

[0052] This embodiment also provides a battery cell, which includes a battery shell, a battery cell and the above-mentioned cover plate assembly. The battery cell and the connecting piece 100 are both arranged in the battery shell, and the cover plate body is sealed at the opening of the battery shell.

[0053] Furthermore, a tab is protruded from one side of the battery cell facing the cover body, and the connecting piece 100 is fixedly connected to the tab.

[0054] The battery cell adopts the above-mentioned cover plate assembly, which has a high current flow capacity, and the reliability of the connection between the connecting piece 100 and the pole 200 is high. The side surface of the connecting piece 100 away from the cover plate body (that is, the side surface of the connecting piece 100 facing the battery cell), the side surface of the rivet part 220 away from the cover plate body (that is, the side surface of the rivet part 220 facing the battery cell) and the side surface of the column 210 away from the cover plate body (that is, the side surface of the column 210 facing the battery cell) are flush, which can prevent the connecting piece 100, the rivet part 220 and the column 210 from scratching the pole ear, and can also reduce the overall weight of the cover plate assembly. Therefore, the battery cell has a longer service life, higher safety in use, lower risk of circuit breaking and higher energy density.

[0055] It should be noted that the battery cell provided in this embodiment is a cylindrical battery, and in other embodiments, it can also be a square battery. In this embodiment, the above-mentioned pole 200 is a positive pole, and in other embodiments, the above-mentioned pole 200 can also be a negative pole.

[0056] This embodiment also provides a battery module, which includes a connecting bar and the above-mentioned battery cells, the number of which is at least two, and at least two battery cells are conductively connected through the connecting bar. The battery module adopts the above-mentioned battery cells, so the battery module has a longer service life, higher safety in use, lower risk of short circuit and higher energy density.

[0057] This embodiment also provides a battery pack, which includes a battery box and the above-mentioned battery module. The battery module is arranged in the battery box. The battery pack adopts the above-mentioned battery module, so the battery pack has a longer service life, higher safety in use, lower risk of short circuit and higher energy density.

[0058] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the manner in which the present invention is to be implemented. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Cover plate assembly, characterized in that, include: Cover plate body; A connecting piece (100), wherein a rivet groove (110) is provided on a side of the connecting piece (100) facing away from the cover plate body, and a through hole (120) is provided at the bottom of the rivet groove (110); A pole (200), the pole (200) comprising a column (210) and a riveted portion (220), the riveted portion (220) being protruding from the side wall of the column (210), and the riveted portion (220) extending along the circumference of the column (210) to form a closed loop structure, the column (210) being passed through the through hole (120) and being insulated and connected to the cover plate body, the side wall of the column (210) being in contact with the hole wall of the through hole (120), the riveted portion (220) being adapted to the shape of the riveted groove (110), and the riveted portion (220) being embedded in the riveted groove (110), and the side surface of the connecting piece (100) facing away from the cover plate body, the side surface of the riveted portion (220) facing away from the cover plate body, and the side surface of the column (210) facing away from the cover plate body being flush.

2. The cover plate assembly according to claim 1, wherein: The rivet groove (110) and the rivet portion (220) are manufactured using a riveting process.

3. The cover plate assembly according to claim 1, wherein: The edge of the rivet groove (110) is welded to the rivet portion (220); and / or the bottom of the rivet groove (110) is welded to the rivet portion (220); and / or the edge of the through hole (120) is welded to the column (210).

4. The cover plate assembly according to claim 1, wherein: The orthographic projection of the riveting portion (220) on the cover plate body is circular or polygonal.

5. The cover plate assembly according to claim 1, wherein: The bottom of the riveting groove (110) is perpendicular to the axis of the column (210).

6. The cover plate assembly according to claim 1, wherein: The axis of the through hole (120) is located at the center of the bottom of the rivet groove (110).

7. A battery cell, characterized in that The invention comprises a battery shell, a battery cell and a cover plate assembly according to any one of claims 1 to 6, wherein the battery cell and the connecting piece (100) are both arranged in the battery shell, and the cover plate body is sealed at the opening of the battery shell.

8. The battery cell according to claim 7, characterized in that A tab is protruding from one side of the battery cell facing the cover body, and the connecting piece (100) is fixedly connected to the tab.

9. A battery module, characterized in that: The invention comprises a connecting bar and the battery cell according to claim 7 or 8, wherein the number of the battery cells is at least two, and at least two of the battery cells are conductively connected via the connecting bar.

10. A battery pack, characterized in that: It comprises a battery box and the battery module according to claim 9, wherein the battery module is arranged in the battery box.

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