Top cover assembly, battery cell, and battery pack

Abstract

The present application provides a top cover assembly, a battery cell, and a battery pack. The top cover assembly comprises a cover plate, a pole plate, and a sealant; a through hole is formed in the cover plate, and the through hole is configured to be communicated with the interior of a battery cell; the pole plate is mounted on the cover plate and covers the through hole, and the pole plate is provided with a first sealant overflow groove at a position corresponding to the through hole; the opening of the first sealant overflow groove faces the through hole; the sealant is sandwiched between the cover plate and the pole plate, and part of the sealant is filled in the first sealant overflow groove.

Description

Top cover assembly, electric core and battery pack

[0001] The present application claims priority to the Chinese patent application No. 202422411155.6 filed on September 30, 2024 with the China Patent Office, the whole content of the above application is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a top cover assembly, an electric core and a battery pack. BACKGROUND

[0003] In the related art, the electric core includes a mounting shell, a core pack and a top cover assembly. The mounting shell is provided with a mounting cavity and a top opening communicating with the mounting cavity. The core pack is installed in the mounting cavity. The top cover assembly is covered at the top opening of the mounting shell to protect the core pack. The top cover assembly includes a cover plate and a pole plate. The pole plate is press-fit on the cover plate by a sealing glue. The cover plate is provided with a through hole communicating with the mounting cavity to facilitate the electrical connection between the pole plate and the core pack. SUMMARY

[0004] However, when the pole plate is press-fit on the cover plate by the sealing glue, the sealing glue is prone to overflow the cover plate through the through hole on the cover plate, resulting in an increase in the overall thickness of the top cover assembly, which in turn occupies the space in the mounting shell and reduces the energy density of the electric core.

[0005] In a first aspect, the possible implementation manner of the present application provides a top cover assembly. The top cover assembly includes a cover plate, a pole plate and a sealing glue. The cover plate is provided with a through hole configured to communicate with the inside of an electric core. The pole plate is installed on the cover plate and covers the through hole. The pole plate is provided with a first glue overflow groove at a position corresponding to the through hole. The groove opening of the first glue overflow groove faces the through hole. The sealing glue is clamped between the cover plate and the pole plate, and part of the sealing glue is filled in the first glue overflow groove.

[0006] In a second aspect, the possible implementation manner of the present application provides an electric core. The electric core includes a mounting shell, a core pack and the top cover assembly of the possible implementation manner. The mounting shell is provided with a mounting cavity and an opening communicating with the mounting cavity. The core pack is installed in the mounting cavity. The cover plate covers the opening. The pole plate is electrically connected with the core pack at the through hole.

[0007] In a third aspect, the possible implementation manner of the present application provides a battery pack. The battery pack includes the electric core of the possible implementation manner. ADVANTAGEOUS EFFECTS

[0008] The top cover assembly provided by the application sets the first overflow groove on the pole plate, the first overflow groove is set at the position corresponding to the through hole on the cover plate, and the slot of the first overflow groove faces the through hole on the cover plate. Thus, the first overflow groove forms a space for the sealant to overflow in the direction away from the through hole. When the pole plate is pressed and combined to the cover plate by the sealant, the sealant is more likely to overflow into the first overflow groove and be partially filled in the first overflow groove, that is, the sealant is not easy to overflow through the through hole on the cover plate, avoiding the increase of the total thickness of the top cover assembly after pressing and combining, and further avoiding the excessive occupation of the space in the mounting shell by the top cover assembly, so as to ensure the energy density of the battery cell. BRIEF DESCRIPTION OF DRAWINGS

[0009] Fig. 1 is a structure sectional view of some possible implementations of the top cover assembly of the application;

[0010] Fig. 2 is a structure exploded view of the top cover assembly in Fig. 1;

[0011] Fig. 3 is a structure sectional view of some possible implementations of the pole plate in the top cover assembly of the application;

[0012] Fig. 4 is a structure sectional view of some possible implementations of the top cover assembly of the application before pressing and combining;

[0013] Fig. 5 is a structure sectional view of some possible implementations of the battery cell of the application.

[0014] Explanation of reference signs:

[0015] 100, top cover assembly, 10, cover plate, 11, through hole, 12, first outer periphery, 13, second top surface, 14, second bottom surface, 15, folded part, 20, pole plate, 21, first overflow groove, 210, mounting shell, 211, mounting cavity, 212, opening, 22, first top surface, 220, cell package, 221, first tab, 222, second tab, 23, first bottom surface, 24, explosion-proof area, 25, conductive connection area, 26, second overflow groove, 27, second outer periphery, 28, connecting protrusion, 30, sealant, 31, third outer periphery. Embodiments of the application

[0016] In the description of the application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0017] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, and the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, and the horizontal height of the first feature is lower than that of the second feature.

[0018] In the description of the present embodiment, the terms "upper", "lower", "left", "right", "front", "back" and the like orientation or position relationship are based on the orientation or position relationship shown in the drawings, which is for the convenience of description and simplification of operation, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used to distinguish in description and have no special meaning.

[0019] As shown in FIG. 1, the possible implementation of the present application provides a top cover assembly 100, which comprises a cover plate 10, a pole plate 20 and a sealing glue 30.

[0020] As shown in FIG. 2, the cover plate 10 is provided with a through hole 11, which is arranged to communicate with the inside of the battery cell 200. In some embodiments, the top cover assembly 100 of the present application is applied to a cylindrical battery cell 200, and the outer shape of the cover plate 10 is circular. The through hole 11 penetrates the cover plate 10 along the thickness direction of the cover plate 10, and the through hole 11 is located at the center position of the cover plate 10, that is, the through hole 11 is coaxially arranged with the cover plate 10. As shown in FIG. 5, when the top cover assembly 100 is applied to the battery cell 200, the cover plate 10 is installed at the opening 212 of the mounting shell 210 to cover the opening 212 of the mounting shell 210. The through hole 11 on the cover plate 10 communicates with the mounting cavity 211 in the mounting shell 210, so as to facilitate the electrical connection between the core pack 220 in the mounting cavity 211 and the pole plate 20 mounted on the cover plate 10.

[0021] Of course, when it is necessary to apply the top cover assembly 100 to a square column battery cell 200 or other shaped battery cell 200, the outer shape of the cover plate 10 can be adaptively designed, such as a polygonal shape, an elliptical shape, etc.

[0022] In addition, the shape of the through hole 11 can be circular, square, or other shapes, as long as it is convenient for the pole plate 20 to be electrically connected with the tab of the core package 220, such as in some possible implementations, the through hole 11 and the cover plate 10 are both circular to adapt to the cylindrical battery cell 200.

[0023] It should be noted here that the cover plate 10 is made of a conductive material to facilitate electrical connection with the tab of the core package 220, and the material of the cover plate 10 can be a metal material such as stainless steel, copper, iron, aluminum alloy, or a conductive non-metallic material. In addition, the cover plate 10 can be made by stamping, turning, cutting, etc., and in some embodiments the forming process can be flexibly selected according to actual conditions.

[0024] As shown in FIG. 1, the pole plate 20 is installed on the cover plate 10 and covers the through hole 11, and the pole plate 20 is provided with a first glue overflow groove 21 at a position corresponding to the through hole 11, and the slot of the first glue overflow groove 21 faces the through hole 11.

[0025] In some embodiments, the pole plate 20 is made of a conductive material to facilitate electrical connection with the tab of the core package 220, and the material of the pole plate 20 can be a metal material such as stainless steel, copper, iron, aluminum alloy, or a conductive non-metallic material. In addition, the pole plate 20 can be made by stamping, turning, cutting, etc., and in some embodiments the forming process can be flexibly selected according to actual conditions.

[0026] During assembly, the pole plate 20 is fixed on the cover plate 10, and the area of the pole plate 20 is greater than the area of the through hole 11, so that the pole plate 20 can completely cover the through hole 11, ensuring the sealing of the battery cell 200. In some possible implementations, the pole plate 20 and the through hole 11 are both circular, and the pole plate 20 and the through hole 11 are coaxially arranged, of course, the pole plate 20 and the through hole 11 can also be arranged in different shapes respectively, as long as the pole plate 20 can completely cover the through hole 11 on the cover plate 10.

[0027] Importantly, in some possible implementations, the pole plate 20 has a first bottom surface 23 facing the cover plate 10, and the first bottom surface 23 is recessed with a first glue overflow groove 21 at a position corresponding to the through hole 11, and the slot of the first glue overflow groove 21 faces the through hole 11, so that the first glue overflow groove 21 forms a space for the sealant 30 to overflow away from the through hole 11, thereby preventing the sealant 30 from overflowing from the through hole 11.

[0028] In some embodiments, as shown in FIG. 4, when assembling the top cover assembly 100, the sealant 30 is first sandwiched between the cover plate 10 and the pole plate 20, and the pole plate 20 is pressed on the sealant 30, and the sealant 30 is partially located between the first overflow groove 21 and the through hole 11, and at this time the sealant 30 is a semi-solid glue. Then the pole plate 20 can be pressed on the sealant 30 by hot pressing or cold pressing, at this time the sealant 30 will deform due to the pressure, and because the pole plate 20 is pressed on the sealant 30 from top to bottom, and the first overflow groove 21 is provided above the sealant 30, the sealant 30 is more likely to overflow into the first overflow groove 21, as shown in FIG. 1, after the pressing is completed, the sealant 30 is partially filled in the first overflow groove 21.

[0029] That is, in the present application, by providing the first overflow groove 21 on the pole plate 20, the first overflow groove 21 is provided at a position corresponding to the through hole 11 on the cover plate 10, and the slot of the first overflow groove 21 faces the through hole 11 on the cover plate 10, so that the first overflow groove 21 forms a space for the sealant 30 to overflow in a direction away from the through hole 11, when the pole plate 20 is pressed on the cover plate 10 by the sealant 30, the sealant 30 is more likely to overflow into the first overflow groove 21 and be partially filled in the first overflow groove 21, that is, the sealant 30 is not easy to overflow through the through hole 11 on the cover plate 10, avoiding the increase of the total thickness of the top cover assembly 100 after pressing, and further avoiding the excessive occupation of the space in the mounting shell 210 by the top cover assembly 100, and ensuring the energy density of the battery cell 200.

[0030] In some possible implementations, as shown in FIG. 1, when the inner circumferential wall of the through hole 11 is projected along the thickness direction of the cover plate 10 to the pole plate 20, the projection of the inner circumferential wall of the through hole 11 is located in the first overflow groove 21, or the projection of the inner circumferential wall of the through hole 11 coincides with the inner circumferential wall of the first overflow groove 21.

[0031] In some embodiments, by making the area of the first overflow groove 21 greater than or equal to the area of the through hole 11, and making the first overflow groove 21 capable of completely covering the through hole 11, it can be ensured that the part of the sealant 30 above the through hole 11 can overflow into the first overflow groove 21 during pressing, and further ensure that the sealant 30 is not easy to overflow into the through hole 11.

[0032] For example, in some embodiments, the through hole 11 and the first overflow groove 21 are both circular in shape, the through hole 11 and the first overflow groove 21 are coaxially arranged, and the inner diameter of the first overflow groove 21 is greater than or equal to the inner diameter of the through hole 11, that is, when the inner diameter of the first overflow groove 21 is greater than the inner diameter of the through hole 11, the projection of the inner circumferential wall of the through hole 11 is located in the first overflow groove 21; when the inner diameter of the first overflow groove 21 is equal to the inner diameter of the through hole 11, the projection of the inner circumferential wall of the through hole 11 coincides with the inner circumferential wall of the first overflow groove 21.

[0033] Of course, in other possible implementations, the through hole 11 and the first overflow groove 21 can both be polygonal, elliptical or other shapes, as long as the first overflow groove 21 can completely cover the through hole 11.

[0034] In some possible implementations, as shown in FIG. 2, the pole post plate 20 has a first top surface 22 and a first bottom surface 23 opposite along the thickness direction thereof, the first bottom surface 23 faces the cover plate 10, the first overflow groove 21 is recessed from the first bottom surface 23 to the first top surface 22, and the recessed depth of the first overflow groove 21 is greater than 0 millimeter and less than or equal to 0.98 millimeter. In some embodiments, the recessed depth can be 0.05 millimeter, 0.1 millimeter, 0.15 millimeter, 0.2 millimeter, 0.25 millimeter, 0.3 millimeter, 0.35 millimeter, 0.4 millimeter, 0.45 millimeter, 0.5 millimeter, 0.55 millimeter, 0.6 millimeter, 0.65 millimeter, 0.7 millimeter, 0.75 millimeter, 0.8 millimeter, 0.85 millimeter, 0.9 millimeter, 0.95 millimeter, 0.98 millimeter, etc.

[0035] It can be understood that if the recessed depth of the first overflow groove 21 is too large, it will affect the structural strength of the pole post plate 20. Therefore, by controlling the recessed depth of the first overflow groove 21 to be within 0.98 millimeter, the overflow space can be provided for the sealing glue 30, and the structural strength of the pole post plate 20 can be avoided from being affected.

[0036] It should be noted that when measuring the recessed depth of the first overflow groove 21, the groove bottom of the first overflow groove 21 is measured from the first bottom surface 23 along the thickness direction of the pole post plate 20.

[0037] In some possible implementation manners, as shown in FIG. 3, the pole plate 20 is formed with an explosion-proof area 24 at a position corresponding to the first overflow groove 21. In some embodiments, when the pole plate 20 and the cover plate 10 are made of the same material, the thickness of the pole plate 20 in the explosion-proof area 24 can be less than the thickness of the cover plate 10 at any position. In this way, the pole plate 20 at the explosion-proof area 14 is more likely to be broken by high-pressure gas, thereby achieving the effect of explosion-proof. Alternatively, the pole plate 20 and the cover plate 10 can be made of different materials, and the material of the pole plate 20 is more likely to be broken by high-pressure gas than the material of the cover plate 10. In addition, the first overflow groove 21 on the pole plate 20 corresponds to the through hole 11 on the cover plate 10, so that the position corresponding to the through hole 11 on the pole plate 20 is relatively weak. Thus, the explosion-proof area 24 that can be broken by high-pressure gas is formed, thereby achieving the effect of explosion-proof.

[0038] In some possible implementation manners, the pole plate 20 is provided with a conductive connection area 25 and an explosion-proof area 24 at a position corresponding to the first overflow groove 21. The conductive connection area 25 is provided with a connection protrusion 28 extending from the bottom of the first overflow groove 21 to the through hole 11, and the connection protrusion 28 is arranged to be electrically connected with the core package 220.

[0039] The explosion-proof area 24 is annular and surrounds the conductive connection area. In particular, the thickness of the pole plate 20 in the explosion-proof area 24 is less than the thickness of the cover plate 10 at any position. In this way, the explosion-proof area 24 becomes the weakest position on the entire top cover assembly 100. When the pressure in the battery cell 200 is too large, the explosion-proof area 24 will be broken by the high-temperature and high-pressure gas in the battery cell 200, so that the pressure in the battery cell 200 is released, thereby avoiding explosion. At the same time, because the pole plate 20 is broken at the explosion-proof area 24, the resistance of the entire circuit is increased, which is close to short circuit, thereby blocking the heat generation reaction and avoiding further increase of the internal pressure of the battery, so as to prevent violent explosion, thereby achieving the effect of safety explosion-proof.

[0040] That is, in some possible implementation manners, the effect of explosion-proof is achieved by directly providing the explosion-proof area 24 on the pole plate 20. In this way, the top cover assembly 100 does not need to be provided with an explosion-proof valve at other positions, thereby simplifying the structure of the top cover assembly 100 and reducing the production cost.

[0041] In some possible implementation manners, as shown in FIG. 1, the surface of the pole plate 20 facing the cover plate 10 (i.e., the first bottom surface 23) is further concavely provided with a second overflow groove 26 extending along the outer periphery of the pole plate 20, and the second overflow groove 26 penetrates to the outer peripheral wall of the pole plate 20. The sealing glue 30 is also partially filled in the second overflow groove 26.

[0042] In some embodiments, referring to FIG. 4, if the outer periphery of the pole plate 20 is not provided with the second overflow groove 26, when the pole plate 20 is pressed down to seal the sealant 30, the part of the sealant 30 not covered by the pole plate 20 will overflow upwards, and when the amount of overflow is large, the height of the upward overflow of the sealant 30 can be higher than the first top surface 22 of the pole plate 20, thereby increasing the total thickness of the top cover assembly 100.

[0043] In some possible implementations, by providing the second overflow groove 26 on the outer periphery of the pole plate 20, referring to FIG. 4, when the pole plate 20 is pressed down to seal the sealant 30, the part of the sealant 30 corresponding to the second overflow groove 26 will overflow upwards and into the second overflow groove 26, thereby filling the second overflow groove 26. That is, a part of the overflow of the sealant 30 will be limited in the second overflow groove 26, reducing the amount of overflow of the sealant 30 outside the pole plate 20, thereby making the overflow of the sealant 30 not easily protrude from the first top surface 22 of the pole plate 20, thereby avoiding the situation that the total thickness of the top cover assembly 100 after being assembled is greater than the preset total thickness, and in addition, the provision of the second overflow groove 26 can also avoid the situation that the size of the overflow of the sealant 30 outside the pole plate 20 is unstable.

[0044] In some possible implementations, the depth of the second overflow groove 26 is greater than 0 mm and less than or equal to 0.98 mm, and in some embodiments, the depth can be 0.08 mm, 0.1 mm, 0.18 mm, 0.2 mm, 0.28 mm, 0.3 mm, 0.38 mm, 0.4 mm, 0.48 mm, 0.8 mm, 0.88 mm, 0.6 mm, 0.68 mm, 0.7 mm, 0.78 mm, 0.8 mm, 0.88 mm, 0.9 mm, 0.98 mm, etc.

[0045] It can be understood that if the depth of the second overflow groove 26 is too large, it will affect the structural strength of the pole plate 20, therefore, by controlling the depth of the second overflow groove 26 to be within 0.98 mm, it can provide space for the overflow of the sealant 30, and also avoid affecting the structural strength of the pole plate 20.

[0046] It should be noted that when measuring the depth of the second overflow groove 26, the depth should be measured from the first bottom surface 23 to the bottom of the second overflow groove 26 along the thickness direction of the pole plate 20.

[0047] In some possible implementation manners, as shown in FIG. 1, the cover plate 10 has a first outer periphery 12, the pole plate 20 has a second outer periphery 27, and the sealing glue 30 has a third outer periphery 31, which is located between the first outer periphery 12 and the second outer periphery 27, that is, the outer periphery of the sealing glue 30 protrudes from the outer periphery of the pole plate 20, so that good insulation between the pole plate 20 and the cover plate 10 can be achieved, and the situation that the pole plate 20 is short-circuited with the cover plate 10 at the outer periphery of the pole plate 20 is avoided.

[0048] It should be noted that the shapes of the cover plate 10, the pole plate 20 and the sealing glue 30 can be flexibly set according to actual needs, as long as the third periphery is located between the first periphery and the second periphery.

[0049] For example, in some embodiments, the shapes of the cover plate 10, the pole plate 20 and the sealing glue 30 are all circular, and the outer diameter of the sealing glue 30 is greater than the outer diameter of the pole plate and less than the outer diameter of the cover plate 10, so that the third periphery is located between the first periphery and the second periphery.

[0050] Of course, the shapes of the cover plate 10, the pole plate 20 and the sealing glue 30 can also be similar polygons, ellipses and the like with different sizes.

[0051] In some possible implementation manners, as shown in FIG. 1, the pole plate 20 further protrudes a connecting protrusion 28 in the first glue overflow groove 21, the connecting protrusion 28 is arranged to be electrically connected with the core package 220 in the battery cell 200, the sealing glue 30 is arranged around the connecting protrusion 28, and the inner periphery wall of the sealing glue 30 is located between the inner periphery wall of the through hole 11 and the outer periphery wall of the connecting protrusion 28. It can be understood that in this way, the glue overflow of the sealing glue 30 can be accommodated by the first glue overflow groove 21, and the position (i.e., the connecting protrusion 28) for electrically connecting with the core package 220 on the pole plate 20 can be ensured.

[0052] It should be noted that the inner periphery wall of the sealing glue 30, the outer periphery wall of the connecting protrusion 28 and the inner periphery wall of the through hole 11 can be circular, elliptical, polygonal or other shapes, as long as the inner periphery wall of the sealing glue 30 is located between the inner periphery wall of the through hole 11 and the outer periphery wall of the connecting protrusion 28.

[0053] For example, in some embodiments, the shapes of the sealing glue 30, the through hole 11 and the connecting protrusion 28 are all circular, the inner diameter of the sealing glue 30 is greater than or equal to the outer diameter of the connecting protrusion 28, and less than the inner diameter of the through hole 11, so that the inner periphery wall of the sealing glue 30 is located between the inner periphery wall of the through hole 11 and the outer periphery wall of the connecting protrusion 28.

[0054] In some possible implementations, as shown in FIG. 1, the connecting protrusion 28 protrudes from the slot of the first overflow groove 21, and since the first overflow groove 21 is recessed along the thickness direction of the pole plate 20 from the first bottom surface 23 to the first top surface 22, the connecting protrusion 28 protrudes from the slot of the first overflow groove 21, that is, protrudes from the first bottom surface 23 of the pole plate 20. It can be understood that in this way, the situation that the sealant 30 covers the lower surface of the connecting protrusion 28 when the sealant 30 overflows and then affects the electrical connection between the connecting protrusion 28 and the core package 220 can be avoided.

[0055] In some possible implementations, as shown in FIG. 1, the pole plate 20 has a first top surface 22 and a first bottom surface 23 opposite along the thickness direction thereof, the cover plate 10 has a second top surface 13 and a second bottom surface 14 opposite along the thickness direction thereof, the sealant 30 is partially clamped between the first bottom surface 23 and the second top surface 13, and the sealant 30 does not protrude from the first top surface 22 and the first bottom surface 23. In this way, when the top cover assembly 100 is produced, the thickness dimension of the top cover assembly 100 can be better controlled, and the situation that the thickness dimension of the top cover assembly 100 is unstable during production can be avoided.

[0056] In some possible implementations, the thickness of the cover plate 10 at any position thereof (except the through hole 11) is greater than or equal to 0.05 mm and less than or equal to 1 mm, and in some embodiments, the thickness can be 0.05 mm, 0.15 mm, 0.25 mm, 0.35 mm, 0.45 mm, 0.55 mm, 0.65 mm, 0.75 mm, 0.85 mm, 0.95 mm, 1 mm, and the like.

[0057] It can be understood that if the thickness of the cover plate 10 is too small, the structural strength of the cover plate 10 will be weak and cannot play a better protection role; and if the thickness of the cover plate 10 is too large, the cover plate 10 will be too thick and heavy, which is not conducive to the lightweight design of the battery cell 200.

[0058] Therefore, some possible implementations control the thickness of the cover plate 10 at any position thereof to be between 0.05 mm and 1 mm, which can not only ensure the structural strength of the cover plate 10, but also be conducive to the lightweight design of the top cover assembly 100 and the battery cell 200.

[0059] In some possible implementations, the thickness of the pole plate 20 at any position thereof is greater than or equal to 0.05 mm and less than or equal to 1 mm, and in some embodiments, the thickness can be 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, and the like.

[0060] It can be understood that if the thickness of the pole plate 20 is too small, the structural strength of the pole plate 20 will be weak and cannot play a good protection role; and if the thickness of the pole plate 20 is too large, the pole plate 20 will be too thick and heavy, which is not conducive to the lightweight design of the battery cell 200.

[0061] Therefore, some possible implementations control the thickness of the pole plate 20 at any position thereof to be between 0.05 millimeters and 1 millimeter, which can ensure the structural strength of the pole plate 20 and is conducive to the lightweight design of the top cover assembly 100 and the battery cell 200.

[0062] It should be noted here that because the first overflow groove 21, the second overflow groove 26, the connecting protrusion 28 and other structures are provided on the pole plate 20, the thickness of the pole plate 20 at different positions thereof can be different, such as the thickness of the pole plate 20 at the first overflow groove 21 and the second overflow groove 26 is small, and the thickness of the pole plate 20 at the position of the connecting protrusion 28 is large, as long as the thickness is controlled to be between 0.05 millimeters and 1 millimeter.

[0063] In the second aspect, as shown in FIG. 5, the possible implementation of the present application provides a battery cell 200, which comprises a mounting shell 210, a cell pack 220 and a top cover assembly 100. The mounting shell 210 is provided with a mounting cavity 211 and an opening 212 communicating with the mounting cavity 211. The cell pack 220 is installed in the mounting cavity 211. The cell pack 220 is mainly wound by a positive plate, a negative plate and a separator, and is a component for generating an electrochemical reaction in the battery cell 200. The specific structure of the cell pack 220 can refer to the related technology, and will not be described in more detail here. The specific structure of the top cover assembly 100 refers to the possible implementation, and the cover plate 10 in the top cover assembly 100 covers the opening 212, thereby completely sealing the mounting cavity 211, and the pole plate 20 is electrically connected with the cell pack 220 at the through hole 11.

[0064] It can be understood that since the present battery cell 200 adopts all the technical solutions of all possible implementations, it at least has all the beneficial effects brought by the technical solutions of some possible implementations, which will not be described one by one here.

[0065] In some possible implementations, as shown in FIG. 5, the cell pack 220 is provided with a first tab 221 and a second tab 222. One of the first tab 221 and the second tab 222 is a positive tab, and the other is a negative tab. The first tab 221 is electrically connected with the pole plate 20, and the second tab 222 is clamped between the outer peripheral wall of the cover plate 10 and the inner peripheral wall of the mounting cavity 211, and the tab is electrically connected with the cover plate 10, so that the cell pack 220 can realize conduction between the external circuit through the pole plate 20 and the cover plate 10.

[0066] It can be understood that some possible implementations can achieve the electrical connection between the second lug 222 and the cover plate 10 when installing the top cover assembly 100 by clamping the second lug 222 between the outer peripheral wall of the cover plate 10 and the inner peripheral wall of the mounting cavity 211, thereby simplifying the assembly process and improving production efficiency.

[0067] In some possible implementations, as shown in FIG. 5, the outer periphery of the cover plate 10 is provided with a folding portion 15, the folding portion 15 is folded upward, the folding portion 15 extends parallel to the inner peripheral wall of the mounting cavity 211, and the folding portion 15 is attached to the inner peripheral wall of the mounting cavity 211. The second lug 222 is clamped between the folding portion 15 and the inner peripheral wall of the mounting cavity 211.

[0068] It can be understood that some possible implementations can increase the contact area of the cover plate 10 with the mounting shell 210 by providing the folding portion 15 on the outer periphery of the cover plate 10, thereby making the top cover assembly 100 more stable when mounted on the mounting shell 210.

[0069] In a third aspect, the possible implementations of the present application provide a battery pack (not shown), which includes the battery cell 200 of the possible implementations, and the battery cell 200 includes the top cover assembly 100 of the possible implementations. Since the battery pack adopts all the technical solutions of the possible implementations, it at least has all the beneficial effects brought by the technical solutions of the possible implementations, which will not be repeated here.

Claims

1. A top cover assembly, comprising: a cover plate provided with a through hole configured to communicate with an interior of a battery cell; a pole plate mounted on the cover plate and covering the through hole, and the pole plate is provided with a first overflow groove at a position corresponding to the through hole, and an opening of the first overflow groove faces the through hole; and a sealing glue interposed between the cover plate and the pole plate, and the sealing glue is partially filled in the first overflow groove.

2. The roof assembly of claim 1, wherein, When an inner circumferential wall of the through hole is projected along a thickness direction of the cover plate to the pole plate, the projection of the inner circumferential wall of the through hole is located in the first overflow groove, or the projection of the inner circumferential wall of the through hole coincides with an inner circumferential wall of the first overflow groove.

3. The roof assembly of claim 1, wherein, The through hole and the first overflow groove are both circular in shape, and an inner diameter of the first overflow groove is greater than or equal to an inner diameter of the through hole.

4. The roof assembly of claim 1, wherein, The pole plate has a first top surface and a first bottom surface opposite to each other along a thickness direction of the pole plate, the first bottom surface faces the cover plate, the first overflow groove is recessed from the first bottom surface to a majority of the first top surface, and a recessed depth of the first overflow groove is greater than 0 mm and less than or equal to 0.98 mm.

5. The roof assembly of claim 1, wherein, The pole plate is formed with an anti-explosion area at a position corresponding to the first overflow groove.

6. The roof assembly of any of claims 1-5, wherein, A surface of the pole plate facing the cover plate is further recessed with a second overflow groove, the second overflow groove extends along an outer periphery of the pole plate, and the second overflow groove penetrates to an outer circumferential wall of the pole plate, and the sealing glue is further partially filled in the second overflow groove.

7. The roof assembly of claim 6, wherein, The recessed depth of the second overflow groove is greater than 0 mm and less than or equal to 0.98 mm.

8. The roof assembly of any of claims 1-7, wherein, The cover plate has a first outer periphery, the pole plate has a second outer periphery, and the sealing glue has a third outer periphery, and the third outer periphery is located between the first outer periphery and the second outer periphery. Alternatively, the cover plate, the pole plate and the sealing glue are all circular in shape, and an outer diameter of the sealing glue is greater than an outer diameter of the pole plate and less than an outer diameter of the cover plate.

9. The roof assembly of claim 8, wherein, The pole plate is further provided with a connecting protrusion in the first overflow groove, the connecting protrusion is configured to be electrically connected with a core package in the battery cell, and the sealing glue is arranged around the connecting protrusion. An inner circumferential wall of the sealing glue is located between an inner circumferential wall of the through hole and an outer circumferential wall of the connecting protrusion, or the sealing glue, the through hole and the connecting protrusion are all circular in shape, and an inner diameter of the sealing glue is greater than or equal to an outer diameter of the connecting protrusion and less than an inner diameter of the through hole.

10. The roof assembly of claim 9, wherein, The connecting protrusion protrudes from the opening of the first overflow groove.

11. The cap assembly of any one of claim 10, wherein, The pole plate has a first top surface and a first bottom surface opposite to each other along a thickness direction of the pole plate, the cover plate has a second top surface and a second bottom surface opposite to each other along a thickness direction of the cover plate, the sealing glue is partially interposed between the first bottom surface and the second top surface, and the sealing glue does not protrude from the first top surface and the first bottom surface.

12. The roof assembly of any of claims 1-11, wherein, A thickness of the cover plate at any position thereof is greater than or equal to 0.05 mm and less than or equal to 1 mm.

13. The roof assembly of any of claims 1-12, wherein, A thickness of the pole plate at any position thereof is greater than or equal to 0.05 mm and less than or equal to 1 mm. 14.A battery cell, comprising: a mounting shell provided with a mounting cavity and an opening communicating with the mounting cavity; a core pack installed in the installation cavity; and, The top cover assembly of any one of claims 1-13, wherein the cover plate covers the opening, and the pole plate is electrically connected to the core pack at the through hole.

15. A battery pack comprising the battery cell of claim 14.

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