Cover plate assembly and battery

Abstract

The invention discloses a cover plate assembly and a battery, and relates to the technical field of batteries, the cover plate assembly comprises a pole, a cover plate and a pressing plate, the cover plate is provided with a mounting hole penetrating along the thickness direction of the cover plate, the pole is arranged in the mounting hole in a penetrating manner, the pressing plate sleeves the pole, the pole comprises a flanging part, the flanging part is located on the inner side of the cover plate, and the pressing plate is located on the inner side of the cover plate. The projection of the flanging part on the plane where the cover plate is located at least partially coincides with the projection of the pressing plate on the plane where the cover plate is located. Moreover, the specifications of the pressing plate and the flanging part are matched with each other, so that the pressing plate and the flanging part are matched with each other, the cover plate assembly is prevented from forming a structural weak point, enough welding space between the pressing plate and the pole can be ensured, the connection strength between the pressing plate and the pole is ensured, and the reliability of the cover plate assembly is improved. The flanging part can be prevented from excessively occupying the internal space of the battery, and the space utilization rate of the battery cell is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and in particular to a cover plate assembly and a battery. Background Art

[0002] A power battery is a battery that provides power for tools. It generally includes a metal shell, a battery cell disposed in the metal shell, and a cover assembly fixed to the top of the metal shell. The cover assembly is provided with a pole structure, which is responsible for the power transmission of the power battery. Therefore, the stability of the pole structure itself affects the performance of the power battery.

[0003] At present, the existing cover plate assembly generally includes a cover plate, a pressure plate and a pole, wherein the pole is inserted into the cover plate and welded to the pole lug of the battery cell to realize the electrical connection between the pole and the battery cell, and the pressure plate is sleeved on the pole and pressed on the cover plate. The pressure plate is connected and fixed to the pole by welding to realize the fixed connection between the pole and the cover plate.

[0004] During the use of power batteries, the poles are easily pulled by the battery cells or external forces, resulting in deformation of the poles or failure of the welding connection between the poles and the pressure plate. In response to this, existing cover plate assemblies often increase the size of the pressure plate or the poles to strengthen the structural strength of the two. However, increasing the size of the pressure plate will increase the load on the cover plate and increase the risk of deformation of the cover plate. Increasing the size of the poles will occupy the space inside the battery cell, affecting the space utilization rate inside the battery cell. Summary of the invention

[0005] The object of the present invention is to provide a cover plate assembly and a battery, which make the overall structure of the cover plate assembly balanced by matching the flanges of the pressure plate and the pole, so as to solve the problem of insufficient matching between the existing pressure plate and the pole.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A cover plate assembly, comprising:

[0008] A cover plate, wherein the cover plate is provided with mounting holes arranged through the cover plate along the thickness direction thereof;

[0009] A pressing plate, the pressing plate is arranged on the outer side of the cover plate;

[0010] A pole, wherein the pole is passed through the mounting hole, and the pressing plate is sleeved on the pole; and the pole comprises:

[0011] A flange portion, for electrically connecting to an output terminal of a battery cell; the flange portion is located on the inner side of the cover plate, and a projection of the flange portion on the plane where the cover plate is located at least partially overlaps with a projection of the pressing plate on the plane where the cover plate is located; and,

[0012] The width of the pressing plate is W1, the thickness of the pressing plate is t1, the width of the flange portion is W2, and the thickness of the flange portion is t2, then the above parameters satisfy:

[0013]

[0014] The width W1 of the pressure plate is the shortest distance from the inner edge to the outer edge of the pressure ring, and the width W2 of the flange portion is the shortest distance from the inner edge to the outer edge of the flange portion.

[0015] In some embodiments, the width of the pressing plate is W1, the thickness of the pressing plate is t1, the width of the flange portion is W2, and the thickness of the flange portion is t2, then the above parameters satisfy: t1>t2, W2>W1.

[0016] In some embodiments, the width of the pressing plate is W1 which satisfies: 2≤W1≤4 mm.

[0017] In some embodiments, the width of the flange portion is W2 and satisfies: 2≤W2≤5mm.

[0018] In some embodiments, the thickness of the pressing plate is t1 satisfying: 1.5≤t1≤3 mm.

[0019] In some embodiments, the thickness of the flange portion is t2 satisfying: 0.5≤t2≤1.5 mm.

[0020] In some embodiments, an insulating member is further included, wherein the insulating member is sleeved on the pole and disposed between the pressing plate and the cover plate to separate the pressing plate from the cover plate; and

[0021] The Rockwell hardness of the insulating component is K, and the Rockwell hardness K of the insulating component satisfies: 40≤K≤120.

[0022] In some embodiments, a seal is further included, the seal is sleeved on the pole, and the seal is arranged on the inner side of the cover plate and between the cover plate and the flange portion, and,

[0023] The projection of the sealing member on the plane where the cover plate is located coincides with the projection of the insulating member on the plane where the cover plate is located.

[0024] In some embodiments, the cover plate is provided with a groove, the groove is arranged around the mounting hole, and the insulating member is at least partially disposed in the groove; and,

[0025] The thickness of the insulating member is t3, and the thickness of the sealing member is t4, then the above parameters satisfy:

[0026]

[0027] In some embodiments, the pressing plate is fixed to the outer peripheral side of the pole by welding, so that a welding mark is formed between the pressing plate and the pole; and

[0028] The width of the weld mark is W3, the height of the weld mark is h, and the compression rate of the seal is W. Then the above parameters satisfy:

[0029]

[0030] In some embodiments, the width of the seal is W4, then the above parameters satisfy:

[0031]

[0032] In some embodiments, the thickness of the cover plate is t5, and the above parameters satisfy:

[0033]

[0034] Based on the above-mentioned cover plate assembly, the present application also provides a battery, which includes a battery cell and any of the above-mentioned cover plate assemblies, and the output end of the battery cell is electrically connected to the pole.

[0035] In some embodiments, a conductive bar is connected to the end surface of the pole facing the outer side of the cover plate.

[0036] In some embodiments, the flange portion is welded to the output end of the battery cell, and the welding area between the flange portion and the output end of the battery cell is S1, and the welding area between the pole and the conductive bar is S2, then the above parameters satisfy:

[0037]

[0038] In some embodiments, the welding area S1 between the flange portion and the output end of the battery cell satisfies: 78≤S1≤706mm 2 .

[0039] Compared with the prior art, the cover plate assembly and battery implemented in this application have the following beneficial effects:

[0040] The pole of the cover plate assembly of the present application is connected and fixed to the cover plate by the cooperation between the pressing plate and the flange part, and the pressing plate is sleeved on the pole on the outer side of the cover plate and fixed to the pole by welding. By controlling the specifications of the pressing plate and the flange part, the pressing plate and the flange part are matched with each other to avoid the formation of structural weak points in the cover plate assembly. In addition, in this way, it can be ensured that there is sufficient welding space between the pressing plate and the pole, thereby ensuring the connection strength between the pressing plate and the pole, and it can be avoided that the flange part excessively occupies the internal space of the battery, ensuring the space utilization rate of the battery cell.

[0041] Moreover, the cover plate assembly of the present application controls the specifications of the insulating parts and the sealing parts so as to balance the overall structure of the cover plate assembly, thereby preventing the overall structure of the cover plate assembly from being unbalanced and causing the structure of the cover plate assembly to fail or be torn. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic diagram of a cover plate assembly in an embodiment of the present application;

[0043] Figure 2 is a partial cross-sectional schematic diagram of a cover plate assembly in an embodiment of the present application;

[0044] Figure 3 is a partial cross-sectional schematic diagram of a cover plate assembly in an embodiment of the present application;

[0045] Figure 4 yes Figure 3 A magnified view of middle;

[0046] Figure 5 is a schematic diagram of a cover plate in an embodiment of the present application;

[0047] Figure 6 Schematic diagram of the pole in the embodiment of the present application.

[0048] In the figure, 100, cover plate assembly;

[0049] 1. Cover plate; 10. Groove; 2. Pole; 20. Main body; 21. Flanged portion; 3. Press plate; 4. Insulator; 5. Welding mark; 6. Sealing member; 7. Mounting hole. DETAILED DESCRIPTION

[0050] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0051] In the description of the present invention, it should be understood that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. The terms "installed", "connected" and "connected" 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, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0052] In the description of the present invention, it should be understood that the terms "height", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used in the present invention to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 invention.

[0053] In the description of the present invention, it should be understood that the terms "first" and "second" are used in the present invention for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0054] Example

[0055] like Figure 1-6 As shown, the embodiment of the present application provides a cover plate assembly 100, which is suitable for a power battery. The cover plate assembly 100 includes a cover plate 1, a pole 2 and a pressure plate 3, wherein the cover plate 1 is provided with a mounting hole 7 arranged through the thickness direction thereof, the pole 2 is penetrated through the mounting hole 7, so that part of the pole 2 passes through the mounting hole 7 and extends to the outside of the cover plate 1, and the pressure plate 3 is arranged on the outside of the cover plate 1 and sleeved on the pole 2.

[0056] It should be noted that the side of the cover plate 1 facing the battery cell is the inner side of the cover plate 1 , and the side opposite to the inner side of the cover plate 1 is the outer side of the cover plate 1 .

[0057] The pole 2 includes a main body 20 and a flange 21, wherein the main body 20 is a columnar structure and is arranged along the thickness direction of the cover plate 1, so that the main body 20 passes through the mounting hole 7 and extends to the outside of the cover plate 1; the flange 21 is formed on the side of the main body 20 facing the battery cell and extends toward the outside of the main body 20, so that the flange 21 is located on the inner side of the cover plate 1, and the projection of the flange 21 on the plane where the cover plate 1 is located at least partially overlaps with the projection of the pressure plate 3 on the plane where the cover plate 1 is located.

[0058] It is understandable that the pressure plate 3 is sleeved on the pole 2 and welded to the pole 2, so that a weld mark 5 is formed between the pressure plate 3 and the pole 2. In this way, the pressure plate 3 will generally fit the outer peripheral surface of the main body 20. Therefore, when the flange portion 21 extends outward from the main body 20, the projections of the flange portion 21 and the pressure plate 3 on the same plane will at least partially overlap. Take the horizontal placement of the cover plate 1 as an example. At this time, the plane where the cover plate 1 is located is the horizontal plane. The projection of the flange portion 21 on the horizontal plane starts from the main body 20 and extends toward the outside of the main body 20. Similarly, since the pressure plate 3 will generally fit the outer peripheral surface of the main body 20, the projection of the pressure plate 3 on the horizontal plane will also start from the main body 20 and extend toward the outside of the main body 20. In this way, according to the width specifications of the flange portion 21 and the pressure plate 3, there is a partial overlap between the projections of the flange portion 21 and the pressure plate 3 on the horizontal plane. The possibility of overlapping or completely overlapping, for example, the width of the flange portion 21 is less than or equal to the width of the pressing plate 3. In this case, the projection of the flange portion 21 on the horizontal plane completely falls into the projection of the pressing plate 3 on the horizontal plane, and the projection of the flange portion 21 and the pressing plate 3 on the horizontal plane completely overlap; the width of the flange portion 21 is greater than the width of the pressing plate 3. In this case, the projection area of ​​the flange portion 21 on the horizontal plane is greater than the projection area of ​​the pressing plate 3 on the horizontal plane, and the projection of the flange portion 21 and the pressing plate 3 on the horizontal plane partially overlap.

[0059] It is understandable that the pole 2 of the cover assembly 100 cooperates with the pressing plate 3 and the flange portion 21 to connect and fix the pole 2 to the cover 1, so the size specifications of the pressing plate 3 and the flange portion 21 will affect the structural stability of the cover assembly 100.

[0060] For example, consider that the pressure plate 3 and the pole 2 are connected and fixed by welding. If the volume of the pressure plate 3 is too small, the connection strength between the pressure plate 3 and the pole 2 is difficult to ensure, which may easily lead to failure of the connection between the pressure plate 3 and the pole 2. Moreover, if the volume of the pressure plate 3 is too small, it may easily lead to laser breakdown of the pressure plate 3 during welding and damage other structures. The larger the volume of the pressure plate 3, the greater the contact area between the pressure plate 3 and the pole 2, which is more conducive to ensuring the welding area between the pressure plate 3 and the pole 2, thereby ensuring the connection strength between the pressure plate 3 and the pole 2. However, if the volume of the pressure plate 3 is too large, the load borne by the cover plate 1 will be greater, and the cover plate 1 will be more likely to deform and cause structural failure.

[0061] Considering that the flange portion 21 is arranged on the inner side of the cover plate 1, it will occupy the space inside the battery cell. The smaller the volume of the flange portion 21, the smaller the volume of the internal space occupied by the flange portion 21, and the easier it is to improve the internal space utilization rate of the battery cell. However, if the volume of the flange portion 21 is too small, it is easy to cause the structural strength of the flange portion 21 to be insufficient, and the flange portion 21 is easy to deform, resulting in failure of the connection between the pole 2 and the battery cell.

[0062] Therefore, the specifications of the pressing plate 3 and the flange portion 21 need to match each other so that the volumes of the two are balanced to avoid the formation of structural weaknesses and failure of the cover plate assembly 100. Generally speaking, the volumes of the pressing plate 3 and the flange portion 21 can be controlled by their respective widths and thicknesses, wherein the width of the pressing plate 3 is W1, the thickness of the pressing plate 3 is t1, the width of the flange portion 21 is W2, and the thickness of the flange portion 21 is t2, then the above parameters satisfy:

[0063]

[0064] The width W1 of the pressing plate 3 is the shortest distance from the inner edge to the outer edge of the pressing ring 3, and the width W2 of the flange portion 21 is the shortest distance from the inner edge to the outer edge of the flange portion 21. For example, the value of the relation (1) can be 0.5, 0.8, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0.

[0065] In order to verify that when the structural parameters of the cover plate assembly 100 provided in this embodiment satisfy the above relationship, that is, when the width W1 of the pressing plate 3, the thickness t1 of the pressing plate 3, the width W2 of the flange portion 21, and the thickness t2 of the flange portion 21 match, the cover plate assembly 100 of this embodiment can avoid structural weak points compared with other cover plate assemblies 100, 10 groups of tests were conducted, refer to the following Table 1:

[0066] In Table 1, Test Examples 1 to 10 are tests based on the structure of the cover plate assembly 100 of the present embodiment, that is, the width W1 of the pressing plate 3, the thickness t1 of the pressing plate 3, the width W2 of the flange portion 21, and the thickness t2 of the flange portion 21 of the cover plate assembly 100 of Test Examples 1 to 10 satisfy the above matching relationship. Comparative Examples 1 and 2 are other cover plate assembly structures, that is, the width W1 of the pressing plate 3, the thickness t1 of the pressing plate 3, the width W2 of the flange portion 21, and the thickness t2 of the flange portion 21 of Comparative Examples 1 and 2 do not satisfy the above matching relationship.

[0067] The tensile force test method is as follows: 20 batteries are taken for each experiment, a tensile block is installed on the surface of the pole 2, and the tensile block is connected to a tensile machine (model: DNS-2). After the pressure ring 3 is fixed, the tensile machine pulls the pole 2 through the tensile block, and the tensile machine sensor (sensor model: CLY30) is turned on to collect the tensile force value of the tensile block until the pole 2 falls off. The maximum value in the tensile force curve is read, and the maximum value in the tensile force curve is above 1200, which is qualified.

[0068] The leakage rate test method is as follows: take 20 batteries for each experiment, put the pole 2 into a special airtight test tool, and then connect the airtight test tool to the helium detector (model: NHJ400). Pass helium into the airtight test tool, and observe whether the leakage rate value of the helium detector exceeds the standard. If the helium detector detects leakage, it is unqualified.

[0069] Table 1

[0070]

[0071]

[0072] As can be seen from Table 1, when the width W1 of the pressing plate 3, the thickness t1 of the pressing plate 3, the width W2 of the flange 21, and the thickness t2 of the flange 21 satisfy the above matching relationship, the cover plate assembly 100 does not have a structural weak point, and the pole 2 of the cover plate assembly 100 can withstand a tensile force of more than 1200N and ensure no air leakage. However, when the width W1 of the pressing plate 3, the thickness t1 of the pressing plate 3, the width W2 of the flange 21, and the thickness t2 of the flange 21 do not satisfy the above matching relationship, the corresponding cover plate assembly will have a structural weak point, resulting in this type of cover plate assembly having the problem that the pole 2 can not withstand enough tensile force or the airtightness is insufficient.

[0073] Considering the welding method of the pressing plate 3 and the pole 2, the thickness t1 of the pressing plate 3 is usually greater than the thickness t2 of the flange 21, that is, t1>t2. In order to avoid the pressing plate 3 being too thick and the flange 21 being too thin, which may cause the overall structure of the cover assembly 100 to be unbalanced, the width W2 of the flange 21 may be greater than the width W1 of the pressing plate 3, that is, W2>W1, so that the volumes of the two are as balanced as possible, and the cover assembly 100 is prevented from forming a structural weak point. Of course, as an example of this embodiment, the width W1 of the pressing plate may also satisfy: 2≤W1≤4mm. For example, the width W1 of the pressing plate may be one of 2mm, 3mm or 4mm to avoid the width W1 of the pressing plate 3 being too large, which may cause the pressing plate 3 to be warped and uneven. Alternatively, by controlling the thickness t1 of the pressing plate 3, the size of the pressing plate 3 may also be controlled within an appropriate range. For example, as an example of this embodiment, the thickness t1 of the pressing plate 3 satisfies: 1.5≤t1≤3mm. Exemplarily, the thickness t1 of the pressing plate 3 may be 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm or 3 mm.

[0074] Moreover, the specifications of the flanging portion 21 and the specifications of the pressing plate 3 need to match each other, and the size of the flanging portion 21 also needs to be controlled within a certain range. For example, as an example of the present embodiment, the width W2 of the flanging portion 21 satisfies: 2≤W2≤5mm. For example, the width W2 of the flanging portion 21 can be 2mm, 3mm, 4mm or 5mm. Alternatively, the specifications of the flanging portion 21 can be controlled by controlling the thickness t2 of the flanging portion 21. As an example of the present embodiment, the thickness t2 of the flanging portion 21 satisfies: 0.5≤t2≤1.5mm. For example, the thickness t2 of the flanging portion 21 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm or 1.5mm.

[0075] In addition, the thickness of the cover plate 1 affects the structural strength of the cover plate 1 itself, and also affects the overall structural balance of the cover plate assembly 100. If the thickness of the cover plate 1 is too small, it is easy to cause the cover plate 1 to deform. Therefore, the thickness t5 of the cover plate 1 and the thickness t1 of the pressure plate 3 should also match each other to avoid forming a structural weak point in the cover plate assembly 100. As an example of this embodiment, the above parameters can meet:

[0076]

[0077] Generally speaking, the thickness t5 of the cover plate 1 can satisfy: 1≤t5≤3mm, so that the cover plate 1 can have sufficient structural strength and avoid the cover plate 1 occupying too much space. Exemplarily, the thickness t5 of the cover plate 1 can be 1mm, 2mm or 3mm.

[0078] refer to Figure 1-6 As an example of this embodiment, the cover plate assembly 100 further includes an insulating member 4, which is sleeved on the pole 2 and disposed between the pressure plate 3 and the cover plate 1 to separate the pressure plate 3 from the cover plate 1. The insulating member 4 forms a buffer between the pressure plate 3 and the cover plate 1. In this way, when the pole 2 is subjected to a pulling force toward the inside of the battery cell, the insulating member 4 can provide a buffer for the weld between the pressure plate 3 and the pole 2, thereby preventing the weld between the pressure plate 3 and the pole 2 from cracking due to repeated impacts.

[0079] It is understandable that when the pole 2 is subjected to a pulling force toward the inside of the battery cell, the pole 2 has a tendency to move toward the inside of the battery cell. Under the constraint of the battery cell, the displacement of the pole 2 in the thickness direction of the cover 1 is very small. However, since the pressing plate 3 is welded and fixed to the pole 2, the pressing plate 3 is driven by the pole 2 to squeeze the insulating member 4. If the deformation of the insulating member 4 due to extrusion is large, it will cause uneven displacement of the pressing plate 3 and the pole 2, and then cause a force along the thickness direction of the cover 1 to the welding point between the pressing plate 3 and the pole 2, that is, the weld mark 5. In order to avoid this situation, it is possible to consider controlling the hardness of the insulating member 4. For example, if the Rockwell hardness of the insulating member 4 is K, the Rockwell hardness K of the insulating member 4 satisfies: 40≤K≤120. Exemplarily, the Rockwell hardness K of the insulating member 4 may be one of 40, 50, 60, 70, 80, 90, 100, 110 or 120, so as to control the deformation of the insulating member 4 due to extrusion and avoid fracture and failure of the weld mark 5.

[0080] refer to Figure 1-6 As an example of this embodiment, the cover plate assembly 100 may further include a seal 6, which is sleeved on the pole 2, and the seal 6 is arranged on the inner side of the cover plate 1 and is disposed between the cover plate 1 and the flange portion 21, and the projection of the seal 6 on the plane where the cover plate 1 is located coincides with the projection of the insulating member 4 on the plane where the cover plate 1 is located.

[0081] It can be understood that, since both the insulating member 4 and the sealing member 6 are sleeved on the pole 2, the projections of the insulating member 4 and the sealing member 6 on the plane where the cover plate 1 is located both start from the main body 20 and extend toward the outside of the main body 20. Therefore, by controlling the length of the sealing member 6 extending from the main body 20 and the length of the insulating member 4 extending from the main body 20, the projection of the sealing member 6 on the plane where the cover plate 1 is located can be made to coincide with the projection of the insulating member 4 on the plane where the cover plate 1 is located, that is, the projection of the insulating member 4 on the cover plate 1 can cover the projection of the sealing member 6 on the cover plate 1, so that the insulating member 4 and the sealing member 6 cooperate with each other, so that the cover plate assembly 100 can obtain better sealing and insulation effects.

[0082] refer to Figure 1-6As an example of this embodiment, the cover plate 1 is provided with a groove 10, and the groove 10 is arranged around the mounting hole 7, and the insulating member 4 is at least partially arranged in the groove 10. The insulating member 4 can adopt various structures. Part of the insulating member 4 is arranged in the groove 10, that is, the pressing plate 3 and the cover plate 1 can be separated, and the remaining part of the insulating member 4 can be adjusted according to the product requirements, such as wrapping the pressing plate 3 by the insulating member 4 to provide installation positioning for the pressing plate 3. By setting the insulating member 4 and the sealing member 6, the pressing plate 3 and the insulating member 4 are arranged on the outside of the cover plate 1, and the sealing member 6 and the flange portion 21 are arranged on the inside of the cover plate 1. The inside and outside of the cover plate 1 are clamped together by these components and form a seal around the pole 2. Of course, in the thickness direction of the cover plate 1, in order to ensure that the cover plate assembly 100 is structurally balanced in its thickness direction, the components located on the inside of the cover plate 1 and the components located on the outside of the cover plate 1 need to constrain each other. For example, if the thickness of the insulating member 4 is t3 and the thickness of the sealing member 6 is t4, then the above parameters meet:

[0083]

[0084] Generally speaking, the thickness t3 of the insulating member 4 can satisfy: 0.5≤t3≤1mm, and the thickness t4 of the sealing member 6 can satisfy: 0.5≤t4≤1mm, so as to ensure that the insulating member 4 and the sealing member 6 do not occupy too much internal space of the cover assembly 100, and ensure the reasonable use of the space of the cover assembly 100. Exemplarily, the thickness t3 of the insulating member 4 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm, and the thickness t4 of the sealing member 6 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm.

[0085] It is understandable that during the use of the power battery, the pole 2 may also be subjected to a pulling force toward the outside of the cover plate 1. In this case, the seal 6 will be compressed due to the extrusion of the flange portion 21, so that the pole 2 has a tendency to move toward the outside of the cover plate 1, thereby generating a force at the welding point between the pole 2 and the pressure plate 3, that is, the weld mark 5. These forces can easily cause the weld mark 5 to break and fail. Therefore, in addition to controlling the hardness of the insulating member 4, the welding area of ​​the weld mark 5 can also be controlled to ensure that the weld mark 5 itself has sufficient connection strength. As an example of this embodiment, the width of the weld mark 5 is W3, the height of the weld mark 5 is h, and the compression rate of the seal 6 is W, then the above parameters satisfy:

[0086]

[0087] The width W3 of the weld mark 5 may satisfy: 0.5≤W3≤2mm to ensure that the welding area of ​​the weld mark 5 is sufficient. In addition, the compression rate W of the seal 6 may satisfy: 20%≤W≤45% to ensure that the seal 6 can withstand the force between the cover plate 1 and the flange portion 21 . Exemplarily, the width W3 of the weld mark 5 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm or 2mm, and the compression rate W of the seal 6 can be 20%, 21%, 22%, 23%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%.

[0088] Moreover, when the pole 2 is subjected to a pulling force in the direction toward the outside of the cover plate 1, the seal 6 is pressed against the inner side of the cover plate 1 due to the extrusion of the flange portion 21, and the seal 6 will generate a corresponding reaction force on the flange portion 21. Since the flange portion 21 and the output end of the battery cell are generally connected and fixed by welding, the flange portion 21 will have a certain weld heat affected zone. If the contact area between the seal 6 and the flange portion 21 is too large, it is easy to cause the entire weld heat affected zone to be subjected to stress for a long time, and then the flange portion 21 will cause fatigue cracking at the position corresponding to the weld heat affected zone. However, if the contact area between the seal 6 and the flange portion 21 is insufficient, it is easy to affect the sealing effect, resulting in failure of the sealing of the cover plate assembly 100. Therefore, the contact area between the seal 6 and the flange portion 21 should also be controlled within an appropriate range so that the structures of the seal 6 and the flange portion 21 match each other. As an example of this embodiment, the width of the flange portion 21 is W2, and the width of the seal 6 is W4, then the above parameters satisfy:

[0089]

[0090] The width W4 of the seal 6 may satisfy: 2≤W4≤5mm, so that the seal 6 can be installed between the cover plate 1 and the flange portion 21, thereby matching the cover plate 1 and the flange portion 21. Exemplarily, the width W4 of the seal 6 may be 2mm, 3mm, 4mm or 5mm.

[0091] Based on the above cover plate assembly, this embodiment further provides a battery, which includes a cell and any of the above cover plate assemblies, wherein the output end of the cell is electrically connected to the pole 2. Moreover, the end surface of the pole 2 facing the outer side of the cover plate 1 is connected to a conductive bar.

[0092] It can be understood that in the battery of the present embodiment, the battery cell, the pole 2 and the conductive bar are welded and fixed by the flange portion 21 and the output end of the battery cell, and the pole 2 and the conductive bar are welded and fixed, so that the battery cell, the pole 2 and the conductive bar form a current path, and the connection area of ​​the flange portion 21 and the output end of the battery cell and the connection area of ​​the pole 2 and the conductive bar are both the flow area of ​​the current path. Therefore, the connection area of ​​the flange portion 21 and the output end of the battery cell and the connection area of ​​the pole 2 and the conductive bar affect the uniformity of the current density of the pole 2 in the current path. The connection area of ​​the flange portion 21 and the output end of the battery cell and the connection area of ​​the pole 2 and the conductive bar match each other, so that there is no narrow part with a sudden increase in resistance in the current path, and the current density of the pole 2 is more uniform, and the local heating will not be excessive due to the increase in resistance of a certain part. Moreover, the connection area of ​​the flange portion 21 and the output end of the battery cell and the connection area of ​​the pole 2 and the conductive bar match each other, so that the inner side of the pole 2 and the outer side of the pole 2 are more balanced, thereby improving the structural strength of the cover plate assembly 100. As an example of this embodiment, the welding area between the flange portion 21 and the output end of the battery cell is S1, and the welding area between the pole 2 and the conductive bar is S2, and the above parameters satisfy:

[0093]

[0094] It should be noted that the welding area S1 between the flange portion 21 and the output end of the battery cell refers to the cross-sectional area of ​​the welding area between the flange portion 21 and the output end of the battery cell, with the cross section perpendicular to the thickness direction of the cover plate 1 as the cross section. Similarly, the welding area S2 between the pole 2 and the conductive bar refers to the cross-sectional area of ​​the welding area between the pole 2 and the conductive bar, with the cross section perpendicular to the thickness direction of the cover plate 1 as the cross section.

[0095] Of course, in a power battery, the weight of the battery cell is generally large, and the pulling force generated by the battery cell on the flange portion 21 is greater than the pulling force generated by the pole 2 on the pressure plate 3. Therefore, in addition to the connection area between the flange portion 21 and the output end of the battery cell and the connection area between the pole 2 and the conductive bar, the welding area S1 between the flange portion 21 and the output end of the battery cell and the welding area S2 between the pole 2 and the conductive bar can also be configured in an appropriate range to meet the stress release requirements between the flange portion 21 and the output end of the battery cell and between the pole 2 and the conductive bar, so as to avoid connection failure between the flange portion 21 and the output end of the battery cell and between the pole 2 and the conductive bar. As an example of this embodiment, the welding area S1 between the flange portion 21 and the output end of the battery cell can meet the following requirements: 78≤S1≤706mm 2 , the welding area S2 between pole 2 and conductive bar can meet the following requirements: 100≤S1≤800mm 2 For example, the welding area S1 between the flange portion 21 and the output end of the battery cell can be 78 mm 2 、79mm2 、80mm 2 、90mm 2 、95mm 2 、100mm 2 、105mm 2 、110mm 2 、115mm 2 、120mm 2 、125mm 2 、130mm 2 、140mm 2 、150mm 2 、160mm 2 、170mm 2 、180mm 2 、190mm 2 、200mm 2 、210mm 2 、220mm 2 、230mm 2 、240mm 2 、250mm 2 、260mm 2 、270mm 2 、280mm 2 、290mm 2 、300mm 2 、310mm 2 、320mm 2 、330mm 2 、340mm 2 、350mm 2 、360mm 2 、370mm 2 、380mm 2 、390mm 2 、400mm 2 、410mm 2 、420mm 2 、430mm 2 、440mm 2 、450mm 2 、460mm 2 、470mm 2 、480mm 2 、490mm 2 、500mm 2 、510mm 2 、520mm 2 、530mm 2 、540mm 2 、550mm 2、560mm 2 、570mm 2 、580mm 2 、590mm 2 、600mm 2 、610mm 2 、620mm 2 、630mm 2 、640mm 2 、650mm 2 、660mm 2 、670mm 2 、680mm 2 、690mm 2 、700mm 2 、701mm 2 、702mm 2 、703mm 2 、704mm 2 、705mm 2 、706mm 2 One of the dimensions, the welding area S2 between the pole 2 and the conductive bar can be 100mm 2 、105mm 2 、110mm 2 、115mm 2 , 120mm 2 , 125mm 2 、130mm 2 、140mm 2 , 150mm 2 、160mm 2 、170mm 2 、180mm 2 、190mm 2 , 200mm 2 , 210mm 2 、220mm 2 , 230mm 2 , 240mm 2 , 250mm 2 , 260mm 2 、270mm 2 、280mm 2 、290mm 2 、300mm 2 、310mm 2 、320mm 2 、330mm 2 、340mm 2 、350mm 2 、360mm 2 、370mm2 、380mm 2 、390mm 2 , 400mm 2 、410mm 2 、420mm 2 、430mm 2 、440mm 2 , 450mm 2 、460mm 2 、470mm 2 、480mm 2 、490mm 2 , 500mm 2 、510mm 2 、520mm 2 、530mm 2 、540mm 2 、550mm 2 、560mm 2 、570mm 2 、580mm 2 、590mm 2 、600mm 2 、610mm 2 、620mm 2 、630mm 2 、640mm 2 、650mm 2 、660mm 2 、670mm 2 、680mm 2 、690mm 2 、700mm 2 、710mm 2 、720mm 2 、730mm 2 、740mm 2 , 750mm 2 、760mm 2 、770mm 2 、780mm 2 、790mm 2 , 800mm 2 One of the sizes.

[0096] In summary, the pole 2 of the cover plate assembly 100 provided in the embodiment of the present application cooperates with the pressing plate 3 and the flange portion 21, so that the pole 2 is connected and fixed to the cover plate 1, and the pressing plate 3 is sleeved on the pole 2 on the outer side of the cover plate 1 and is welded and fixed to the pole 2. By controlling the specifications of the pressing plate 3 and the flange portion 21, the pressing plate 3 and the flange portion 21 are matched with each other to avoid the formation of structural weak points in the cover plate assembly 100, and in this way, it can be ensured that there is sufficient welding space between the pressing plate 3 and the pole 2, thereby ensuring the connection strength between the pressing plate 3 and the pole 2, and it can be avoided that the flange portion 21 excessively occupies the internal space of the battery, ensuring the space utilization rate of the battery cell.

[0097] Moreover, the cover assembly 100 of the embodiment of the present application controls the specifications of the insulating component 4 and the sealing component 6 so that the overall structure of the cover assembly 100 is balanced, thereby preventing the overall structure of the cover assembly 100 from being unbalanced and causing the structure of the cover assembly 100 to fail or be torn.

[0098] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A cover plate assembly, characterized in that: include: A cover plate, wherein the cover plate is provided with mounting holes arranged through the cover plate along the thickness direction thereof; A pressing plate, the pressing plate is arranged on the outer side of the cover plate; A pole, wherein the pole is passed through the mounting hole, and the pressing plate is sleeved on the pole; and the pole comprises: A flange portion, for electrically connecting to an output terminal of a battery cell; the flange portion is located on the inner side of the cover plate, and a projection of the flange portion on the plane where the cover plate is located at least partially overlaps with a projection of the pressing plate on the plane where the cover plate is located; and, The width of the pressing plate is W1, the thickness of the pressing plate is t1, the width of the flange portion is W2, and the thickness of the flange portion is t2, then the above parameters satisfy: The width W1 of the pressure plate is the shortest distance from the inner edge to the outer edge of the pressure ring, and the width W2 of the flange portion is the shortest distance from the inner edge to the outer edge of the flange portion.

2. The cover plate assembly according to claim 1, characterized in that: The width W1 of the pressing plate, the thickness t1 of the pressing plate, the width W2 of the flange portion, and the thickness t2 of the flange portion satisfy: t1>t2, W2>W1.

3. The cover plate assembly according to claim 1, characterized in that: The width W1 of the pressing plate satisfies: 2≤W1≤4mm.

4. The cover plate assembly according to claim 1, characterized in that: The width W2 of the flange portion satisfies: 2≤W2≤5mm.

5. The cover plate assembly according to claim 1, characterized in that: The thickness t1 of the pressing plate satisfies: 1.5≤t1≤3mm.

6. The cover plate assembly according to claim 1, characterized in that: The thickness t2 of the flange portion satisfies: 0.5≤t2≤1.5mm.

7. The cover plate assembly according to claim 1, characterized in that: It also includes an insulating member, which is sleeved on the pole and disposed between the pressing plate and the cover plate to separate the pressing plate from the cover plate; and The Rockwell hardness of the insulating component is K, and the Rockwell hardness K of the insulating component satisfies: 40≤K≤120.

8. The cover plate assembly according to claim 7, characterized in that: It also includes a sealing member, which is sleeved on the pole, and is arranged on the inner side of the cover plate and between the cover plate and the flange portion, and, The projection of the sealing member on the plane where the cover plate is located coincides with the projection of the insulating member on the plane where the cover plate is located.

9. The cover plate assembly according to claim 8, characterized in that: The cover plate is provided with a groove, the groove is arranged around the mounting hole, and the insulating member is at least partially arranged in the groove; and, The thickness of the insulating member is t3, and the thickness of the sealing member is t4, then the above parameters satisfy:

10. The cover plate assembly according to claim 8, characterized in that: The pressing plate is welded and fixed to the outer peripheral side of the pole, so that a welding mark is formed between the pressing plate and the pole; and The width of the weld mark is W3, the height of the weld mark is h, and the compression rate of the seal is W. Then the above parameters satisfy:

11. The cover plate assembly according to claim 8, characterized in that: The width of the seal is W4, and the above parameters meet:

12. The cover plate assembly according to claim 1, characterized in that: The thickness of the cover plate is t5, then the above parameters satisfy:

13. A battery, characterized in that: It comprises a pole ear and a cover plate assembly as described in any one of claims 1 to 9, and the output end of the battery cell is electrically connected to the pole.

14. The battery according to claim 13, characterized in that The end surface of the pole facing the outer side of the cover plate is connected with a conductive bar.

15. The battery according to claim 14, characterized in that The flange is welded and fixed to the output end of the battery cell, and the welding area between the flange and the output end of the battery cell is S1, and the welding area between the pole and the conductive bar is S2. The above parameters satisfy:

16. The battery according to claim 15, characterized in that The welding area S1 between the flange portion and the output end of the battery cell satisfies: 78≤S1≤706mm 2 .

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