Top cover assembly, battery monomer, battery and electric device

Abstract

The invention relates to a top cover assembly, a battery monomer, a battery and a power utilization device. The top cover assembly comprises a cover plate which is provided with a first surface, a second surface and a first through hole, the first surface and the second surface are opposite to each other, and the first through hole penetrates through the first surface and the second surface; the pole comprises a first connecting part and at least two second connecting parts, the first connecting part is located on the side, provided with the first surface, of the cover plate, and the second connecting parts are connected with the first connecting part and arranged in the first preset direction; at least part of each second connecting part is arranged in the first through hole in a penetrating manner and is used for being connected with a tab; and the first insulating part comprises a first insulating part arranged between the first connecting part and the cover plate.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, specifically to a top cover assembly, a battery cell, a battery and an electrical device. Background Art

[0002] Lithium-ion batteries have the advantages of high energy density, long cycle life, high rate performance, good safety, and environmental protection. They are important energy products for modern electronic products and electric vehicles. Battery cells are an important component of batteries.

[0003] There are two technical solutions for battery cells: with and without adapter plates. In the adapter plate solution, the tabs of the battery cell are connected to the posts via the adapter plates, making the posts serve as the electrode terminals of the battery cell. However, the presence of the adapter plates increases the number of parts, increasing the cost of the battery cell; it also adds a welding process between the tabs and the adapter plates, further increasing the cost of the battery cell.

[0004] In the adapter-free solution, the post and tab are directly connected. However, due to limited space on the cover, the post's position is restricted, so the tab must be extended to achieve direct connection. Extending the tab significantly increases the risk of the tab being inserted backwards into the battery cell and tearing. Summary of the Invention

[0005] Based on this, it is necessary to provide a top cover assembly, a battery cell, a battery and an electrical device that can omit the adapter and avoid lengthening the tabs to address the above problems.

[0006] In one aspect, the present application provides a top cover assembly, comprising:

[0007] The cover plate has a first surface, a second surface, and a first through hole, wherein the first surface and the second surface are opposite to each other, and the direction from the first surface to the second surface is parallel to the thickness direction of the cover plate and is the direction from the outside to the inside of the top cover assembly, and the first through hole passes through the first surface and the second surface;

[0008] A pole, comprising at least one first connecting portion and at least two second connecting portions, wherein the first connecting portion is located outside the cover plate, and each second connecting portion is connected to the first connecting portion; each second connecting portion is at least partially disposed within the first through hole and is used to be connected to a tab, respectively, and the second connecting portion has an outer surface located outside, and at least a portion of the outer surface is located outside the second surface; and

[0009] The first insulating member includes a first insulating portion provided between the first connecting portion and the cover plate.

[0010] In some embodiments, on an imaginary plane perpendicular to the thickness direction of the cover plate, the orthographic projection of the first connecting portion does not overlap with the orthographic projection of the first through hole, and the orthographic projection of the second connecting portion covers the orthographic projection of the first through hole.

[0011] In some embodiments, each of the second connecting portions includes a first area and a second area arranged around the first area, the second area is connected to the first connecting portion, the first area protrudes relative to the second area along the direction from the first surface to the second surface, and forms a connecting sub-portion passing through the first through hole.

[0012] In some embodiments, an end of the connecting sub-portion away from the second area is a welding end, the welding end has a welding surface, and the welding end protrudes from the second surface of the cover plate.

[0013] In some embodiments, the top cover assembly further includes a second insulating member, which is disposed on the second surface of the cover plate, the welding end is disposed through the second insulating member, and the welding surface protrudes from a side surface of the second insulating member away from the cover plate, or the welding surface is flush with a side surface of the second insulating member away from the cover plate.

[0014] In some embodiments, the distance that the welding end protrudes from the second surface along the thickness direction of the cover plate is 0 to 5 mm.

[0015] In some embodiments, the distance between the weld mark on the welding surface and the edge of the welding surface is greater than or equal to 1 mm.

[0016] In some embodiments, the first insulating member further includes a second insulating portion, and at least a portion of the second insulating portion covers the second region.

[0017] In some embodiments, the first insulating portion and the second insulating portion are integrally formed.

[0018] In some embodiments, an end surface of the connecting sub-part connected to the second region has a first groove, and the second insulating part further covers an inner wall of the first groove.

[0019] In some embodiments, the second insulating portion is recessed toward the first groove to form a pit.

[0020] In some embodiments, the top cover assembly further includes a first fixing portion, which is connected to the first surface of the cover plate and presses against a side of the second insulating portion facing away from the cover plate.

[0021] In some embodiments, the first fixing portion extends along a peripheral edge of the second connecting portion.

[0022] In some embodiments, the first fixing portion includes a first arc segment, a straight edge segment, and a second arc segment connected in sequence, and the first arc segment and the second arc segment are both located on the side of the straight edge segment facing the first connecting portion; an avoidance space is formed between an end of the first arc segment away from the straight edge segment and an end of the second arc segment away from the straight edge segment.

[0023] In some embodiments, the central angle of the first arc segment is greater than 90°; and / or

[0024] The central angle of the second arc segment is greater than 90°.

[0025] In some embodiments, the distance between the end of the first arc segment away from the straight edge segment and the first connecting portion is greater than or equal to 1.4 mm; and / or

[0026] A distance between an end of the second arc segment away from the straight edge segment and the first connecting portion is greater than or equal to 1.4 mm.

[0027] In some embodiments, the first fixing portion includes a standing edge sub-portion and a flanging sub-portion, the standing edge sub-portion is connected to the first surface of the cover plate, the flanging sub-portion is connected to the standing edge sub-portion, and is bent relative to the standing edge sub-portion to a side of the second insulating portion facing away from the cover plate.

[0028] In some embodiments, an insulating gap is provided between an end of the flange sub-portion facing away from the vertical side sub-portion and the second region, and a portion of the second insulating portion is filled in the insulating gap.

[0029] In some embodiments, the second insulating portion further covers the flange sub-portion and at least a portion of the vertical side sub-portion; or

[0030] The second insulating portion does not cover the standing edge sub-portion and the cuff sub-portion.

[0031] In some embodiments, the orthographic projection of the flange sub-portion on the cover plate along the thickness direction of the cover plate is a first orthographic projection, and the orthographic projection of the second connecting portion on the cover plate along the thickness direction of the cover plate is a second orthographic projection; the first orthographic projection and the second orthographic projection partially overlap or do not overlap.

[0032] In some embodiments, the pole further includes a plurality of transition portions corresponding one-to-one to each of the second connection portions, and each of the transition portions is connected between the first connection portion and the corresponding second connection portion.

[0033] In some embodiments, each of the transition portions is provided with a through hole; each of the second connecting portions includes a first region and a second region arranged around the first region, the second region being connected to the first connecting portion, the first region protruding relative to the second region in a direction from the first surface to the second surface and forming a connecting sub-portion passing through the first through hole;

[0034] The first insulating member further includes a second insulating portion and a third insulating portion. The second insulating portion at least partially covers the second region. The third insulating portion fills the through hole and is connected to the first insulating portion and the second insulating portion.

[0035] In some embodiments, the first insulating portion, the second insulating portion, and the third insulating portion are integrally formed.

[0036] In some embodiments, the top cover assembly further includes a sealing ring, which includes a first sealing portion and a second sealing portion, both of which are sleeved on the connecting sub-portion, the first sealing portion being located between the connecting sub-portion and the inner wall of the first through hole, and the second sealing portion being located between the second area and the first surface of the cover plate.

[0037] In some embodiments, the first surface of the cover plate has a first convex strip arranged around the first through hole, and the second sealing portion presses against the first convex strip.

[0038] In some embodiments, the sealing ring further includes a second ridge, which is protrudingly disposed on a side of the second sealing portion facing away from the cover plate and is arranged around the second area.

[0039] In some embodiments, the second protrusion is C-shaped, and an opening of the second protrusion faces the first connecting portion.

[0040] In some embodiments, a second groove is formed on a side of the first connecting portion facing the cover plate, and a portion of the first insulating portion is filled in the second groove.

[0041] In some embodiments, the second groove is at least partially narrowed gradually or in a step-like manner from the groove bottom to the groove opening.

[0042] In some embodiments, the depth dimension of the second groove is h1, the thickness dimension of the first connecting portion is H1, and h1 and H1 satisfy: h1 = (5% to 50%) H1.

[0043] In some embodiments, a third groove is formed on a surface of the cover plate facing the first connecting portion, and a portion of the first insulating portion is filled in the third groove.

[0044] In some embodiments, the third groove narrows gradually or in a step-wise manner from the groove bottom to the groove opening.

[0045] In some embodiments, the depth dimension of the third groove is h2, the thickness dimension of the cover plate is H2, and h2 and H2 satisfy: h2 = (5% to 50%) H2.

[0046] In some embodiments, the first connecting portion has a boss and an annular surface on a side facing away from the cover plate, the annular surface is arranged around the boss, and the boss is protruded relative to the annular surface in a direction facing away from the cover plate;

[0047] The first insulating member further includes a fourth insulating portion, which is arranged around the first connecting portion and covers a peripheral edge of the first connecting portion;

[0048] A surface of the fourth insulating portion is flush with the annular surface.

[0049] In some embodiments, two second connection parts are provided, and the two second connection parts are respectively located on both sides of the first connection part in a first preset direction, where the first preset direction is the width direction of the cover plate; or

[0050] Each of the second connection portions is located on the same side of the first connection portion in the second preset direction, and the second preset direction is the length direction of the cover plate.

[0051] On the other hand, the present application provides a battery cell, comprising a housing, a battery cell assembly, and a top cover assembly as described in any of the above embodiments;

[0052] The shell has a receiving cavity and an opening connected to the receiving cavity, the cover is arranged at the opening, the battery cell assembly is arranged in the receiving cavity, and has at least two pole ears on the side facing the cover, and each second connecting portion passes through the first through hole into the receiving cavity and is connected to the corresponding pole ear.

[0053] In another aspect, the present application provides a battery cell, comprising:

[0054] The housing has a receiving cavity and a first wall serving as a side wall of the receiving cavity, the first wall having an inner side surface, an outer side surface, and a first through hole, the inner side surface facing the receiving cavity, the outer side surface facing away from the receiving cavity, and the first through hole passing through the inner side surface and the outer side surface;

[0055] A battery cell assembly is accommodated in the accommodation cavity of the shell and has at least two tabs on a side facing the first wall;

[0056] A pole, comprising a first connecting portion and at least two second connecting portions, wherein the first connecting portion is provided on the outer surface of the first wall, and each of the second connecting portions is connected to the first connecting portion and arranged along the width direction of the first wall; each of the second connecting portions is at least partially provided in the first through hole and is respectively connected to the corresponding pole lug; and

[0057] The first insulating member includes a first insulating portion provided between the first connecting portion and the first wall.

[0058] On the other hand, the present application provides a battery, characterized by comprising a battery cell as described in any of the above embodiments.

[0059] On the other hand, the present application provides an electrical device, including the battery cell as described in any of the above embodiments, or including the battery as described in any of the above embodiments.

[0060] Compared with the prior art, this application has the following beneficial effects:

[0061] The above-mentioned top cover assembly, battery cell, battery and electrical device, the pole is directly connected to the pole ears of the two groups of battery cells through the two second connecting parts. On the one hand, it avoids the use of adapters, thereby reducing the number of parts of the top cover assembly and reducing one welding process; on the other hand, by arranging the two second connecting parts along the arrangement direction of the two groups of battery cells, the two second connecting parts pass through the cover plate through the first through hole on the cover plate and are respectively connected to the pole ears of the two groups of battery cells, thereby avoiding the need to increase the radial size of the pole and the need to extend the pole ear, thereby avoiding increasing the material cost of the pole ear and increasing the risk of adverse phenomena such as the pole ear being inserted upside down into the battery cell and the pole ear being torn. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a cross-sectional view of a battery cell at a pole in one embodiment of the present application (the cross section is perpendicular to the length direction of the cover plate);

[0063] Figure 2 for Figure 1 A schematic structural diagram of a top cover assembly of a battery cell shown;

[0064] Figure 3 for Figure 2 A schematic diagram of the exploded structure of the top cover assembly shown;

[0065] Figure 4 for Figure 2 A cross-sectional view of the top cover assembly shown (the cross section is perpendicular to the length direction of the cover);

[0066] Figure 5 for Figure 2 A schematic structural diagram of the pole of the top cover assembly shown;

[0067] Figure 6 for Figure 5 The cross-section of the pole shown (the cross section is perpendicular to the length direction of the cover);

[0068] Figure 7 for Figure 2 A schematic structural diagram of the sealing ring of the top cover assembly shown;

[0069] Figure 8 for Figure 2 A schematic structural diagram of the cover plate of the top cover assembly shown;

[0070] Figure 9 for Figure 2 A schematic structural diagram of the first insulating member of the top cover assembly shown;

[0071] Figure 10 This is a cross-sectional view of the top cover assembly at the pole in another embodiment of the present application (the cross section is perpendicular to the length direction of the cover plate). DETAILED DESCRIPTION

[0072] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0073] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0074] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0075] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. 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 elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0076] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0077] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0078] One embodiment of the present application provides an electrical device, a battery, and a battery cell. The electrical device includes a battery or a battery cell, and can be provided with electrical energy by the above-mentioned battery or the above-mentioned battery cell. The above-mentioned electrical device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, an energy storage device, an amusement ride, an elevator and a lifting device, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, or electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.; energy storage devices can be energy storage walls, base station energy storage, container energy storage, etc.; amusement rides can be carousels, bungee jumping machines, etc.

[0079] The vehicle may be a fuel-powered vehicle, a gas-powered vehicle, or a new energy vehicle. A new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle. For new energy vehicles, the battery may serve as a driving power source, thereby replacing fossil fuels in providing driving power. This application does not impose any specific restrictions on the electrical device.

[0080] The above-mentioned battery can be a battery pack or a battery module. When the above-mentioned battery is a battery pack, the battery pack specifically includes a battery management system (BMS) and a plurality of the above-mentioned battery cells. The plurality of battery cells can be electrically connected in series, in parallel, or in a combination of series and parallel, and can be communicated with the battery management system, which controls and monitors the working status of each battery cell. In addition, the plurality of battery cells can also be first formed into a battery module with the module management system, and then the plurality of battery modules can be electrically connected in series, in parallel, or in a combination of series and parallel, and together with the battery management system form a battery pack.

[0081] Multiple battery cells can be installed on supporting structures such as boxes, frames, and brackets. The battery cells and the battery management system can be electrically connected through electrical connectors, which can be busbars. In addition, the battery cells can also be electrically connected by plugging in their respective poles. For example, between two adjacent battery cells, a slot is provided on the pole of one battery cell, and a plug-in is correspondingly provided on the pole of the other battery cell. The plug-in is inserted into the slot to achieve electrical connection. Therefore, for a battery cell, the aforementioned electrical connector can be the pole of another battery cell. Similarly, the battery cell and the battery management system can also be electrically connected by plugging in each other, which will not be described in detail here. The above-mentioned battery cell can be a lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery, and its external contour can be cylindrical, flat, rectangular, or other shapes, but is not limited to these. Specifically in the present embodiment, the above-mentioned battery cell is a lithium-ion square battery.

[0082] See also Figure 1 The battery cell 1 includes a shell 200, a cell assembly 300, and a top cover assembly 100. The shell 200 is provided with an opening at at least one end, and the shell 200 has a receiving cavity therein, which is connected to the opening. The cell assembly 300 is received in the receiving cavity of the shell 200, and the top cover assembly 100 covers the opening of the shell 200, thereby enclosing the cell assembly 300 in the receiving cavity of the shell 200. The cell assembly 300 includes at least two groups of cells 301 arranged side by side along the thickness direction of the shell 200, and each group of cells 301 extends a tab 302 toward the end surface of the top cover assembly 100.

[0083] It should be noted that each group of battery cells 301 can be one battery cell 301 or multiple battery cells 301, which is not limited here. When each group of battery cells 301 includes one battery cell 301, the battery cell 301 extends a positive electrode tab and a negative electrode tab toward the end surface of the top cover assembly 100. When each group of battery cells 301 includes multiple battery cells 301, each battery cell 301 extends a positive electrode tab and a negative electrode tab toward the end surface of the top cover assembly 100, and the positive electrode tabs on each battery cell 301 in the same group are close together to form a positive electrode tab, and the negative electrode tabs on each battery cell 30 in the same group are close together to form a negative electrode tab.

[0084] As an embodiment, the battery cell assembly 300 includes two groups of battery cells 301, each group of battery cells 301 includes one battery cell 301, that is, the battery cell assembly 300 includes a total of two battery cells 301, and the two battery cells 301 are arranged side by side along the thickness direction of the shell 200, wherein the positive electrode ear on the end face of one battery cell 301 facing the top cover assembly 100 serves as a positive electrode ear, and the negative electrode ear serves as a negative electrode ear; wherein the positive electrode ear on the end face of the other battery cell 301 facing the top cover assembly 100 serves as another positive electrode ear, and the negative electrode ear serves as another negative electrode ear.

[0085] In the prior art, adapter plates are used to connect each positive tab to the positive post on the top cap assembly. However, the presence of adapter plates increases the number of parts, increasing the cost of the battery cell and increasing the internal resistance of the battery cell, which reduces the energy efficiency of the battery cell. Furthermore, the additional welding process between the tab and the adapter plate further increases the cost of the battery cell. To overcome these drawbacks, a technical solution without adapter plates has been adopted.

[0086] In the technical solution without an adapter, the positive pole on the top cover assembly extends directly into the receiving cavity and is directly connected to the positive tabs of each group of battery cells. However, since each group of battery cells is arranged along the thickness direction of the shell, the positive tabs of each group of battery cells are also arranged along the thickness direction of the shell. Since the span of each positive tab in the thickness direction of the shell is large, the positive tab needs to be arranged in the middle of the shell in the thickness direction, so the positive pole of conventional size cannot be directly connected to each positive tab. Therefore, in order to achieve direct connection between the positive pole and each positive tab, one way is to increase the radial dimension of the pole so that the pole is as close to the positive tabs on both sides as possible in the thickness direction of the shell to ensure that each positive tab can be directly connected to the positive pole; another way is to extend the length of the positive tab so that each positive tab extends to the positive pole and is directly connected to the positive pole.

[0087] However, during long-term research and development, the inventors of this application discovered that increasing the radial dimensions of the pole increases the material cost of the pole, and the mounting holes for the poles are larger, resulting in insufficient strength of the top cover assembly. Extending the length of the positive tab increases the risk of the tab being inserted upside down into the battery cell and tearing. It should be noted that the direct connection between the negative pole and the negative tab also has the above-mentioned drawbacks, which will not be discussed here.

[0088] In order to overcome the above-mentioned defects, the inventors of the present application have creatively proposed a pole that can realize direct connection between the pole and the tab. In the technical solution of the present application, the pole is formed by a plate through a stamping process (such as piercing, drawing and cutting, etc.). The pole includes a first connecting portion and at least two second connecting portions connected to the first connecting portion, and the at least two second connecting portions are arranged along a first preset direction, and the first preset direction is consistent with the thickness direction of the shell 200. In other words, the arrangement direction of each second connecting portion is consistent with that of each group of battery cells 301, so that each second connecting portion is opposite to the tab 302 of each group of battery cells 301 one by one, so that the tab 302 of each group of battery cells 301 is directly connected to the corresponding second connecting portion, thereby avoiding the need to increase the radial size of the pole or extend the length of the tab 302, thereby overcoming the defects caused by increasing the radial size of the pole and extending the tab 302.

[0089] The following is a detailed description of the specific structure of the top cover assembly with reference to the accompanying drawings. Figures 1 to 6 As shown, in the embodiment of the present application, the top cover assembly 100 includes a cover plate 10 and a pole 20. The cover plate 10 has a first surface a1, a second surface a2 and a first through hole 11. The first surface a1 and the second surface a2 are opposite to each other in the thickness direction of the cover plate 10. The direction parallel to the thickness direction of the cover plate 10 and pointing from the first surface a1 to the second surface a2 is the direction from the outside to the inside of the top cover assembly. The first surface a1 is located on the outside of the cover plate 19, and the second surface a2 is located on the inside of the cover plate 10. The first through hole 11 passes through the first surface a1 and the second surface a2 of the cover plate 10. The cover plate 10 is covered at the opening of the shell 200 to seal the opening of the shell 200. The first surface a1 of the cover plate 10 faces away from the battery cell assembly 300 in the receiving cavity of the shell 200, and the second surface a2 of the cover plate 10 faces the battery cell assembly 300 in the receiving cavity of the shell 200. The thickness direction of the shell 200 is consistent with the first preset direction, that is, the two groups of battery cells 301 of the battery cell assembly 300 in the shell 200 are arranged side by side along the first preset direction, so the tabs 302 of the two groups of battery cells 30 are also arranged at intervals along the first preset direction.

[0090] The electrode post 20 is disposed on the cover plate 10 , and its thickness is aligned with that of the cover plate 10 . The cover plate 10 may be provided with a positive electrode post 20 and a negative electrode post 20 . The positive electrode post 20 is used to connect to the positive tab of each group of battery cells 301 , thereby leading the positive tab of each group of battery cells 301 out of the housing 200 ; the negative electrode post 20 is used to connect to the negative tab of each group of battery cells 301 , thereby leading the negative tab of each group of battery cells 301 out of the housing 200 . The positive electrode post 20 serves as the positive terminal of the battery cell 1 , while the negative electrode post 20 serves as the negative terminal of the battery cell 1 . Electrical connectors are used to connect the positive and negative terminals of each battery cell 1 , enabling electrical connection of the battery cells 1 in series, parallel, or a combination of series and parallel.

[0091] It should be noted that, because the positive and negative electrode posts 20 have similar structures, for ease of understanding, this document uses one of the posts 20 as an example. That is, a "post" herein can refer to either the positive or negative electrode post 20 (unless explicitly noted otherwise), and a "tab" herein can refer to either the positive or negative tab (unless explicitly noted otherwise), as long as all tabs 302 connected to the positive post 20 are positive tabs, and all tabs 302 connected to the negative post 20 are negative tabs.

[0092] Specifically, the pole 20 includes a first connection portion 21 and two second connection portions 22. The first connection portion 21 is located on the side of the cover plate 10 having the first surface a1, that is, the outer side of the cover plate 10, and the two second connection portions 22 are both connected to the first connection portion 21. The two second connection portions 22 are arranged along a first preset direction, that is, the arrangement direction of the two second connection portions 22 is consistent with the arrangement direction of the tabs 302 of the two groups of battery cells 301. At least a portion of each second connection portion 22 is passed through the first through hole 11 on the cover plate 10 and is used to connect to the corresponding tab 302 respectively. In other words, the two second connection portions 22 are connected to the tabs 302 of the two groups of battery cells 301 in a one-to-one correspondence.

[0093] The second connection portion 22 has an outer surface located on the outside, with at least a portion of the outer surface located on the outside of the second surface a2. Along the outside-to-inside direction of the top cover assembly 100, the second connection portion 22 has opposing outer and inner sides, with the outer surface located on the outside and the inner surface located on the inside. In other words, the second connection portion 22 has opposing outer and inner surfaces along the outside-to-inside direction of the top cover assembly 100; along the outside-to-inside direction of the top cover assembly 100, the second surface a2 also has opposing outer and inner sides. At least a portion of the outer surface of the second connection portion 22 is located on the outside of the second surface a2. In other words, along the outside-to-inside direction of the top cover assembly 100, at least a portion of the outer surface of the second connection portion 22 does not exceed the second surface a2 of the cover plate 10.

[0094] In the above-mentioned top cover assembly 100, the pole 20 is directly connected to the pole tabs 302 of the two groups of battery cells 301 through the two second connecting parts 22. On the one hand, the use of adapters is avoided, thereby reducing the number of parts of the top cover assembly 100 and reducing one welding process; on the other hand, by arranging the two second connecting parts 22 along the arrangement direction of the two groups of battery cells 301, the two second connecting parts 22 pass through the cover plate 10 through the first through hole 11 on the cover plate 10 and are respectively connected to the pole tabs 302 of the two groups of battery cells 301, thereby avoiding the need to increase the radial size of the pole 20 and the need to extend the pole tab 302, thereby avoiding increasing the material cost of the pole tab 302 and increasing the risk of adverse phenomena such as the pole tab 302 being inserted upside down into the battery cell and the pole tab 302 being torn.

[0095] It is understandable that the number of the second connection parts 22 is not limited to two, but can also be three or more. The number of the second connection parts 2232 is related to the number of battery cell groups. Specifically, the number of battery cell groups is N groups, and the number of the second connection parts 22 is also set to N. The N second connection parts 22 are arranged at intervals along the first preset direction and are all connected to the first connection part 21. The N second connection parts 22 are respectively provided through the first through holes 11 on the cover plate 10 and are connected to the pole ears 302 of each group of battery cells 301 in a one-to-one correspondence, so that the pole ears 302 of each corresponding battery cell 301 are all led out to the first connection part 21. For ease of understanding, this article takes the battery cell assembly 300 including two groups of battery cells 301 and the pole 20 including two second connection parts 22 as an example for explanation.

[0096] It should also be noted that the number of first connecting portions 21 is not limited to one, but may be two or more. The number of first connecting portions 21 is related to the number of second connecting portions 22. A first connecting portion 21 is provided between two adjacent second connecting portions 22. In this case, the number of first connecting portions 21 is N-1. For example, when the number of second connecting portions 22 is 3 and the number of first connecting portions 21 is 2, the pole 20 includes, along the first predetermined direction, a second connecting portion 22, a first connecting portion 21, a second connecting portion 22, a first connecting portion 21, and a second connecting portion 22, which are sequentially connected.

[0097] In one embodiment, a first through hole 11 may be provided on the cover plate 10 . The first through hole 11 is a hole with a relatively large area, which allows at least two second connection parts 22 to pass through the first through hole 11 .

[0098] It is understood that in another embodiment, a first through hole 11 is provided on the cover plate 10 at a position corresponding to each second connecting portion 22, so that each second connecting portion 22 is respectively inserted into the corresponding first through hole 11 and then connected to the corresponding terminal lug 302. In this way, compared with the first through hole 11 in which the entire terminal is mounted on the cover plate 10, in this embodiment, only the first through hole 11 that matches the outer contour size of the second connecting portion 22 is required. This greatly reduces the opening area on the cover plate 10, minimizes the adverse effects on the strength of the cover plate 10, and ensures that the strength of the cover plate 10 meets the requirements.

[0099] See Figures 4 to 6As shown, in the embodiment of the present application, each second connection portion 22 includes a first area 221 and a second area 222 arranged around the first area 221. The second area 222 is connected to the first connection portion 21, and the outer side surface of the second area 222 is located on the outer side of the second surface a2. The first area 221 protrudes relative to the second area 222 along the direction from the first surface a1 to the second surface a2, and forms a connection sub-portion 223 that is inserted into the corresponding first through hole 11. In this way, the first area 221 of the second connection portion 22 can be drawn once or multiple times using a stamping process, so that the first area 221 protrudes relative to the second area 222 toward the cover plate 10 to form a connection sub-portion 223. The connection sub-portion 223 extends through the corresponding first through hole 11 to the pole ear 302 of the corresponding battery cell group and is directly connected to the pole ear 302.

[0100] Furthermore, the end of the connecting sub-portion 223 away from the second region 222 is a welding end a3, which passes through the corresponding first through-hole 11 and enters the receiving cavity of the housing 200. In other words, the welding end a3 of the connecting sub-portion 223 protrudes from the second surface a2 of the cover plate 10, thereby avoiding welding the tab 302 to the welding end a3 of the connecting sub-portion 223 inside the first through-hole 11, greatly reducing the welding difficulty and facilitating improving the welding quality of the welding end a3 between the tab 302 and the connecting sub-portion 223.

[0101] Furthermore, the distance that the welding end a3 of the connecting sub-portion 223 protrudes from the second surface a2 of the cover plate 10 along the thickness direction of the cover plate 10 is 0 to 5 mm, thereby avoiding occupying a large space in the receiving cavity due to the welding end a3 protruding from the second surface a2 too much, that is, saving space in the receiving cavity of the shell 200, which is beneficial to improving the energy density of the battery.

[0102] Furthermore, the top cover assembly 100 also includes a second insulating member 60, which is arranged on the second surface a2 of the cover plate 10 and is used to form insulation between the cover plate 10 and the battery cell assembly 300. The second insulating member 60 has a third through hole opposite to the first through hole 11, and the connecting sub-portion 223 is inserted into the corresponding first through hole 11 and the second through hole. The welding end a3 of the connecting sub-portion 223 has a welding surface a4, which protrudes from the side surface of the second insulating member 60 away from the cover plate 10, or the welding surface a4 is flush with the side surface of the second insulating member 60 away from the cover plate 10. In this way, welding of the tab 302 and the welding surface a4 of the connecting sub-portion 223 inside the third through hole is avoided, which greatly reduces the difficulty of welding and is conducive to improving the welding quality of the welding surface a4 of the tab 302 and the connecting sub-portion 223.

[0103] It should be noted that the connection sub-portion 223 and the tab 302 may be welded using welding processes such as laser welding, resistance welding, ultrasonic welding, and pressure fusion welding.

[0104] As an embodiment, the tab 302 is welded and fixed to the connecting sub-section 223 by pressure fusion welding. Specifically, a protrusion 227 is provided on the welding surface a4 of the connecting sub-section 223. During pressure fusion welding, the tab 302 contacts the protrusion 227. Since the flow area at the contact point between the tab 302 and the protrusion 227 is small, the heat generated is large, causing the protrusion 227 to melt and weld the tab 302 to the welding surface a4 of the connecting sub-section 223. It is understandable that the shape of the protrusion 227 can be spherical, hemispherical, truncated cone, etc., as long as it can ensure that the protrusion 227 can melt under the action of electrical energy and pressure and weld the tab 302 to the welding surface a4 of the connecting sub-section 223, and no limitation is made here.

[0105] As another embodiment, the tab 302 is fixed to the connecting sub-section 223 by laser welding. Specifically, the distance between the weld mark on the welding surface a4 of the welding end a3 and the edge of the welding surface a4 is greater than or equal to 1 mm. Alternatively, the distance between the weld mark on the welding surface a4 and the edge of the welding surface a4 can be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, or 2.0 mm, etc., without particular limitation.

[0106] It should be noted that the distance between the weld mark on the weld surface a4 and the edge of the weld surface a4 refers to the distance between any point on the edge of the weld surface a4 and any point on the edge of the weld mark.

[0107] Specifically in this embodiment, a first groove 225 is formed on the end surface of the connecting sub-portion 223 connected to the second region 222, giving the connecting sub-portion 223 a hollow structure, which helps reduce the weight of the pole 20 and save material for the pole 20. It is understood that during the process of one or more deep drawing of the plate, the first region 221 of the plate bulges out toward one side relative to the second region 222, thereby forming a hollow connecting sub-portion 223.

[0108] Optionally, the depth of the first groove 225 is 1 mm to 5 mm, preferably 1 mm to 3 mm. If the depth of the first groove 225 is too shallow, the welding end a3 of the connecting sub-section 223 will be far away from the battery cell assembly 300, requiring a longer tab 302; if the depth of the first groove 225 is too deep, the drawing process will be more difficult. In this embodiment, by rationally designing the depth of the first groove 225, the depth of the first groove 225 is moderate, which can achieve welding between the tab 302 and the welding end a3 of the connecting sub-section 223 without lengthening the tab 302, and reduce the difficulty of the drawing process, thereby improving production efficiency and the yield rate of the pole 20.

[0109] It should be noted that the depth of the first groove 225 can be 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm or 5.0 mm, etc., and is not particularly limited here.

[0110] In the embodiment of the present application, the pole 20 further includes a transition portion 23, through which the second region 222 of each second connecting portion 22 is connected to the first connecting portion 21. The end of the transition portion 23 connected to the second region 222 of the second connecting portion 22 is a first end, and the first end at least partially protrudes from the side surface of the first connecting portion 21 facing the cover plate 10 along the thickness direction of the pole 20. In other words, the transition portion 23 extends obliquely relative to the thickness direction of the pole 20 from the end connected to the first connecting portion 21 to the end connected to the second region 222, so that the second connecting portion 22 is generally lowered toward the cover plate 10 relative to the first connecting portion 21. This, in turn, brings the connecting sub-portion 223 closer to the corresponding terminal lug 302, which helps minimize the drawing depth of the connecting sub-portion 223, reduces the drawing difficulty, and improves the drawing quality of the pole 20.

[0111] Furthermore, the flow area of ​​the transition portion 23 is smaller than that of the first connection portion 21 and smaller than that of the second connection portion 22. Thus, in the event of a circuit anomaly during actual use, the smaller flow area of ​​the transition portion 23 causes the temperature there to rise more rapidly, allowing the transition portion 23 to fuse quickly, thereby promptly severing the circuit and significantly improving battery safety. It will be appreciated that the flow area of ​​the transition portion 23 can be reduced by creating grooves, openings, and / or localized thinning, ensuring that the circuit can be promptly severed by fusing in the event of an anomaly.

[0112] In the embodiment of the present application, the top cover assembly 100 further includes a first insulating member 30, which includes a first insulating portion 31. The first insulating portion 31 is disposed between the first connecting portion 21 of the pole 20 and the cover plate 10 to provide insulation, that is, to prevent electrical conduction between the first connecting portion 21 of the pole 20 and the cover plate 10.

[0113] Furthermore, the first insulating member 30 also includes a second insulating portion 34, which covers the second area 222 of the pole 20. On the one hand, the second insulating portion 34 insulates and protects the outer surface of the second area 222, and on the other hand, it wraps the second area 222 of the pole 20, which is beneficial to increase the overall strength of the pole 20 and reduce the risk of deformation of the pole 20.

[0114] Furthermore, the second insulating part 34 also covers the inner wall of the first groove 225. On the one hand, it provides insulation protection for the inner wall of the first groove 225. On the other hand, it is conducive to increasing the bonding force between the second insulating part 34 and the second connecting part 22, thereby greatly reducing the risk of positional displacement or even separation between the second insulating part 34 and the second connecting part 22.

[0115] Furthermore, the second insulating portion 34 is recessed toward the first groove 225 to form a pit 341. That is, the second insulating portion 34 only covers the inner wall of the first groove 225 and does not fill the first groove 225. On the one hand, it is beneficial to improve the bonding force between the second insulating portion 34 and the second connecting portion 22 of the pole 20, avoiding separation or misalignment of the second insulating portion 34 and the second connecting portion 22; on the other hand, it reduces the material usage of the second insulating portion 34 and avoids defects such as uneven injection molding due to local excessive thickness.

[0116] Furthermore, the second insulating portion 34 extends to each transition portion 23 and covers each transition portion 23, thereby insulating and protecting the surface of the transition portion 23. The first insulating member 30 also includes a fourth insulating portion 35. The fourth insulating portion 35 extends along the peripheral edge of the first connecting portion 21 and covers the peripheral edge of the second insulating portion 34, thereby facilitating improvement of the overall strength of the pole 20 and insulating and protecting the peripheral edge of the first connecting portion 21. In other words, the side surface of the first connecting portion 21 facing the cover plate 10 is covered by the first insulating portion 31, and the peripheral edge of the first connecting portion 21 is covered by the fourth insulating portion 35. Only the side surface of the first connecting portion 21 facing away from the cover plate 10 is uncovered, and this uncovered surface is used for welding to the electrical connector.

[0117] Specifically, in this embodiment, the first connecting portion 21 has a boss 211 and an annular surface 213 on the side facing away from the cover plate 10. The annular surface 213 surrounds the boss 211, and the boss 211 protrudes from the annular surface 213 in a direction away from the cover plate 10. The electrical connector is welded to the boss 211, and the fourth insulating portion 35 of the first insulating member 30 is lower than or flush with the annular surface 213. Thus, the provision of the boss 211 prevents the injection material from flowing onto the surface of the boss 211 during injection molding, thereby preventing the first insulating member 30 from covering the surface of the boss 211.

[0118] Optionally, the protrusion height of the boss 211 relative to the annular surface 213 is 0.05 mm to 0.8 mm, preferably 0.1 mm to 0.6 mm or 0.3 mm to 0.5 mm. It should be noted that the protrusion height of the boss 211 relative to the annular surface 213 can be 0.05 mm, 0.20 mm, 0.35 mm, 0.50 mm, 0.65 mm, or 0.8 mm, etc., and is not particularly limited here.

[0119] Specifically, in this embodiment, at least one second through-hole 231 is defined in the transition portion 23, and the first insulating member 30 further includes a third insulating portion 32 that fills the second through-hole 231. The third insulating portion 32 is connected to the first insulating portion 31, the second insulating portion 34, and the fourth insulating portion 35, thereby forming a single unit. This improves the bonding strength between the first insulating member 30 and the pole 20 and further enhances the overall strength of the pole 20.

[0120] Furthermore, the first insulating portion 31, the second insulating portion 34, and the third insulating portion 32 of the first insulating member 30 are integrally formed, for example, using an injection molding process. During injection molding of the first insulating member 30, a portion of the molten injection molding material flows onto the surfaces of each second connecting portion 22 and each transition portion 23, and solidifies to form the second insulating portion 34; a portion of the molten injection molding material flows onto the surface of the peripheral edge of the first connecting portion 21, and solidifies to form the fourth insulating portion 35; a portion of the injection molding material flows into the second through hole 231, and solidifies to form the third insulating portion 32; and a portion of the injection molding material flows through the second through hole 231 into the space between the first connecting portion 21 and the cover plate 10, and solidifies to form the first insulating portion 31 between the first connecting portion 21 and the cover plate 10.

[0121] It should be noted that the second through hole 231 on the transition portion 23, on the one hand, plays a role in circulating the injection molding material during injection molding, and on the other hand, also plays a role in reducing the flow area of ​​the transition portion 23, ensuring that the transition portion 23 can be melted in time to cut off the circuit when an abnormality occurs.

[0122] Please also see Figure 7 As shown, specifically in the embodiment, the top cover assembly 100 further includes a first fixing portion 40. The first fixing portion 40 is fixedly connected to the first surface a1 of the cover plate 10, and a portion of the first fixing portion 40 can be bent to the side surface of the second insulating portion 34 facing away from the cover plate 10 using a rolling process, so that the first fixing portion 40 is used to press the second insulating portion 34 and the terminal 20 against the cover plate 10, thereby preventing the terminal 20 from separating from the cover plate 10.

[0123] Furthermore, the second insulating portion 34 has a stepped surface a6 extending along the peripheral edge of the second region 222 of the second connecting portion 22. The first fixing portion 40 extends along the peripheral edge of the second connecting portion 22 and presses against the stepped surface a6, making the pressure of the first fixing portion 40 on the second insulating portion 34 more stable, thereby further strengthening the assembly structure of the terminal 20 and the cover plate 10, and preventing the terminal 20 from shifting or even separating from the cover plate 10.

[0124] It should be noted that the number of first fixing portions 40 is the same as the number of second connecting portions 22, and the two are arranged in a one-to-one correspondence. Each first fixing portion 40 presses against the second insulating portion 34 on the surface of the corresponding second connecting portion 22, thereby pressing each second connecting portion 22 of the pole 20 against the cover plate 10. Optionally, each first fixing portion 40 extends in a C-shape along the peripheral edge of the corresponding second connecting portion 22, with the opening of the C-shaped first fixing portion 40 facing the first connecting portion 21, so that the transition portion 23 passes through the opening of the first fixing portion 40, thereby preventing the fourth insulating portion 35 covering the peripheral edge of the first connecting portion 21 and the second insulating portion 34 covering the transition portion 23 from interfering with the rolling equipment when the first fixing portion 40 is rolled.

[0125] Specifically, the first fixing portion 40 includes a first arc segment 45, a straight-side segment 47, and a second arc segment 49, which are sequentially connected. The first arc segment 45 and the second arc segment 49 are both located on the side of the straight-side segment 47 facing the first connecting portion 21. A clearance space a5 is formed between the end of the first arc segment 45 away from the straight-side segment 47 and the end of the second arc segment 49 away from the straight-side segment 47. It will be appreciated that this clearance space a5 is the space at the opening of the C-shaped first fixing portion 40.

[0126] Optionally, the central angle of the first arc segment 45 is greater than 90°, which is conducive to extending the length of the first fixing portion 40 so that the first fixing portion 40 can more firmly press the second insulating portion 34 and the second connecting portion 22 onto the cover plate 10.

[0127] Optionally, the central angle of the second arc segment 49 is greater than 90°, which is conducive to extending the length of the first fixing portion 40 so that the first fixing portion 40 can more firmly press the second insulating portion 34 and the second connecting portion 22 onto the cover plate 10.

[0128] It should be noted that in order to improve the clamping effect, the length of the first fixing part 40 needs to be extended as much as possible. However, extending the length of the first fixing part 40 will cause the distance between the first arc segment 45 and / or the end of the second arc segment 49 away from the straight edge segment 47 and the first connecting part 21 to be too close, which will cause the fourth insulating part 35 wrapped around the peripheral edge of the first connecting part 21 to interfere with the rolling equipment when the first fixing part 40 is rolled.

[0129] To prevent interference between the fourth insulating portion 35 wrapped around the lateral edge of the first connecting portion 21 and the hemming equipment during the hemming operation on the first arc segment 45, in some embodiments, the distance between the end of the first arc segment 45 away from the straight edge segment 47 and the first connecting portion 21 is greater than or equal to 1.4 mm, so that the distance between the end of the first arc segment 45 away from the straight edge segment 47 and the first connecting portion 21 is large enough to ensure that the fourth insulating portion 35 on the lateral edge of the first connecting portion 21 does not interfere with the hemming equipment during the hemming operation on the first arc segment 45.

[0130] It should be noted that the distance between the end of the first arc segment 45 away from the straight edge segment 47 and the first connecting portion 21 can be 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm or 1.8 mm, etc., which is not particularly limited here.

[0131] To prevent interference between the fourth insulating portion 35 wrapped around the lateral edge of the first connecting portion 21 and the hemming equipment during the hemming operation on the second arc segment 49, in some embodiments, the distance between the end of the second arc segment 49 away from the straight edge segment 47 and the first connecting portion 21 is greater than or equal to 1.4 mm, so that the distance between the end of the second arc segment 49 away from the straight edge segment 47 and the first connecting portion 21 is large enough to ensure that the fourth insulating portion 35 on the lateral edge of the first connecting portion 21 does not interfere with the hemming equipment during the hemming operation on the second arc segment 49.

[0132] It should be noted that the distance between the end of the second arc segment 49 away from the straight edge segment 47 and the first connecting portion 21 can be 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm or 1.8 mm, etc., which is not particularly limited here.

[0133] Specifically, in this embodiment, the first fixing portion 40 includes an upright portion 41 and a flange portion 43. The upright portion 41 is connected to the first surface a1 of the cover plate 10. The flange portion 43 is connected to the upright portion 41 and is bent relative to the upright portion 41 to the stepped surface a6 of the second insulating portion 34. The flange portion 43 thereby compresses the second insulating portion 34, thereby securing the first insulating member 30 and the terminal 20 to the cover plate 10.

[0134] Furthermore, an insulating gap 430 is defined between the end of the flange sub-portion 43 facing away from the vertical side sub-portion 41 and the second region 222 of the second connecting portion 22. Part of the second insulating portion 34 fills the insulating gap 430, thereby achieving insulation between the flange sub-portion 43 and the second region 222 of the second connecting portion 22.

[0135] To more firmly press the second connecting portion 22 against the cover plate 10, in some embodiments, the orthographic projection of the flange sub-portion 43 along the thickness direction of the cover plate 10 on the cover plate 10 is a first orthographic projection, and the orthographic projection of the second connecting portion 22 along the thickness direction of the cover plate 10 on the cover plate 10 is a second orthographic projection. The first orthographic projection of the flange sub-portion 43 partially overlaps with the second orthographic projection of the second connecting portion 22, that is, the flange sub-portion 43 and the second connecting portion 22 overlap in the thickness direction of the cover plate 10.

[0136] In other embodiments, the first orthographic projection of the flange sub-portion 43 does not overlap with the second orthographic projection of the second connecting portion 22 , that is, there is no overlapping portion between the flange sub-portion 43 and the second connecting portion 22 in the thickness direction of the cover plate 10 .

[0137] It should also be noted that because each second connection portion 22 is pressed against the cover plate 10 by the first fixing portion 40, the bond between the first connection portion 21 and the cover plate 10 is weak, which can cause uneven force on the pole 20, leading to warping or even cracking. To prevent warping or cracking of the pole 20 due to uneven force, in some embodiments, a second groove 210 is defined on the surface of the first connection portion 21 facing the cover plate 10, and a third groove 12 is defined on the surface of the cover plate 10 facing the first connection portion 21. A portion of the first insulating portion 31 fills the second groove 210, and a portion of the first insulating portion 31 also fills the third groove 12. This allows the molten injection material to flow into the second groove 210 and the third groove 12 during injection molding of the first insulating member 30. After solidification, the first insulating portion 31 partially fills the second groove 210 and the third groove 12, resulting in a structure in which the first insulating portion 31 partially fills the second groove 210 and the third groove 12. This helps improve the bonding strength between the first connection portion 21, the first insulating portion 31, and the second connection portion 22.

[0138] Furthermore, at least a portion of the second groove 210 gradually narrows or narrows in a step-like manner from the groove bottom to the groove opening, thereby allowing the first insulating portion 31 to be tightly nested on the pole 20 through the second groove 210, preventing the pole 20 from separating from the first insulating member 30. At least a portion of the third groove 12 gradually narrows or narrows in a step-like manner from the groove bottom to the groove opening, thereby allowing the first insulating portion 31 to be tightly nested on the cover plate 10 through the third groove 12, preventing the cover plate 10 from separating from the first insulating member 30.

[0139] Optionally, the depth dimension of the second groove 210 is h1, and the thickness dimension of the first connecting portion 21 is H1, and h1 and H1 satisfy: h1 = (5% to 50%) × H1. Preferably, h1 and H1 satisfy: h1 = (10% to 20%) × H1. In this way, by designing the depth of the second groove 210 within an appropriate range, on the one hand, the depth of the second groove 210 is avoided from being too shallow, resulting in an insignificant effect of increasing the bonding force between the first insulating portion 31 and the first connecting portion 21; on the other hand, the depth of the second groove 210 is avoided from being too deep, resulting in low strength of the first connecting portion 21 and easy deformation. It should be noted that h1 can be 5% × H1, 10% × H1, 15% × H1, 20% × H1, 25% × H1, 30% × H1, 35% × H1, 40% × H1, 45% × H1 or 50% × H1, etc., and is not specifically limited here.

[0140] It should be noted that the number of second grooves 210 can be one or more, and is not specifically limited here. When there is only one second groove 210, the second groove 210 itself is arranged symmetrically with respect to the centerline of the first connecting portion 21, thereby preventing defects such as warping or cracking of the terminal 20 due to uneven force. When there are multiple second grooves 210, the multiple second grooves 210 are arranged symmetrically with respect to the centerline of the first connecting portion 21, thereby preventing defects such as warping or cracking of the terminal 20 due to uneven force.

[0141] Optionally, the depth dimension of the third groove 12 is h2, and the thickness dimension of the cover plate 10 is H2, and h2 and H2 satisfy: h2 = (5% to 50%) H2. Preferably, h2 and H2 satisfy: h2 = (10% to 20%) × H2. In this way, by designing the depth of the third groove 12 within an appropriate range, on the one hand, the depth of the third groove 12 is avoided from being too shallow, resulting in a poor effect of increasing the bonding force between the first insulating portion 31 and the cover plate 10; on the other hand, the depth of the third groove 12 is avoided from being too deep, resulting in a weak strength of the cover plate 10 and easy deformation. It should be noted that h2 can be 5% × H2, 10% × H2, 15% × H2, 20% × H2, 25% × H2, 30% × H2, 35% × H2, 40% × H2, 45% × H2, or 50% × H2, etc., without special limitation herein.

[0142] It should be noted that the number of third grooves 12 can be one or more, and is not particularly limited here. When there is only one third groove 12, the third groove 12 itself is symmetrically arranged relative to the centerline of the cover plate 10 to prevent defects such as warping or cracking of the cover plate 10 due to uneven force. When there are multiple third grooves 12, the multiple third grooves 12 are symmetrically arranged relative to the centerline of the cover plate 10 to prevent defects such as warping or cracking of the cover plate 10 due to uneven force.

[0143] See Figure 3 、 Figure 6 and Figure 7 As shown, in this embodiment, the top cover assembly 100 further includes a sealing ring 50, which includes a first sealing portion 51 and a second sealing portion 53. Both the first sealing portion 51 and the second sealing portion 53 are sleeved onto the connecting sub-portion 223. The first sealing ring 50 is located between the inner wall of the first through-hole 11 and the connecting sub-portion 223, while the second sealing portion 53 is located between the surface of the cover plate 10 facing away from the cell assembly 300 and the second region 222. In this manner, the sealing ring 50 seals the first through-hole 11 in the cover plate 10, preventing leakage of electrolyte from the housing 200 through the first through-hole 11. Furthermore, the sealing ring 50 insulates the connecting sub-portion 223 and the second region 222 from the cover plate 10, preventing electrical conduction between the terminal 20 and the cover plate 10. It should be noted that, under the pressure of the flanged sub-portion 43, the first sealing portion 51 and the second sealing ring 50 of the sealing ring 50 are compressed, thereby sealing the first through-hole 11.

[0144] Furthermore, the first surface a1 of the cover plate 10 has a first ridge 13 surrounding the first through hole 11. The second sealing portion 53 presses against the first ridge 13, thereby increasing the contact area between the sealing ring 50 and the cover plate 10, extending the sealing path, and improving the sealing effect.

[0145] It should be noted that the first ridge 13 provided around the first through hole 11 on the first surface a1 of the cover plate 10 can also strengthen the area of ​​the cover plate 10 near the first through hole 11, thereby greatly reducing the risk of deformation or warping of the cover plate 10.

[0146] Furthermore, the sealing ring 50 includes a second ridge 55. The second ridge 55 is provided protrudingly on the side of the second sealing portion 53 facing away from the cover plate 10 and is arranged around the second region 222. In other words, the second sealing portion 53 contacts the entire surface of the second region 222 facing the cover plate 10, and the second ridge 55 on the second sealing portion 53 also extends to the end surface of the second region 222, which further improves the sealing effect.

[0147] Furthermore, the second ridge 55 extends along the peripheral edge of the second region 222 in a C-shape, with the opening of the second ridge 55 facing the first connecting portion 21. Thus, since the second region 222 of the second connecting portion 22 is connected to the first connecting portion 21 via the transition portion 23, the second ridge 55 is configured in a C-shape. The space at the opening of the second ridge 55 is utilized for the transition portion 23 to pass through, thereby preventing interference between the second ridge 55 and the transition portion 23.

[0148] Specifically in the embodiment, on a virtual plane perpendicular to the thickness direction of the cover plate 10, the orthographic projection of the first connecting portion 21 does not overlap with the orthographic projection of the first through hole 11, and the orthographic projection of the second connecting portion 22 covers the orthographic projection of the first through hole 11, so that the position where the first connecting portion 21 is welded to the electrical connector is sufficiently far away from each second connecting portion 22, and thus when the electrical connector is welded to the boss 211 of the first connecting portion 21, the adverse effects of the heat generated by the welding on the first insulating portion 30 and the sealing ring 50 are greatly reduced, which is beneficial to reducing the risk of cracking or hot melting of the first insulating portion 30 and improving the sealing reliability of the sealing ring 50.

[0149] It should be noted that the assembly method of the top cover assembly 100 can be a pre-injection molding method or an integral injection molding method. Figure 9 As shown, the pre-injection molding method means: first, forming the pole 20 by a stamping process; then, the first insulating member 30 is injection-molded on the pole 20, so that the pole 20 and the first insulating member 30 form a whole; then, the sealing ring 50 is sleeved on the connecting sub-portion 223 of the pole 20, and the connecting sub-portion 223 of the pole 20 is inserted into the first through-hole 11 on the cover 10; then, the first fixing portion 40 is rolled, so that the flanged sub-portion 43 of the first fixing portion 40 is bent onto the second insulating portion 34 of the first insulating member 30, thereby pressing the pole 20 and the first insulating member 30 onto the cover 10, and at the same time, the sealing ring 50 is compressed so that the sealing ring 50 seals the first through-hole 11.

[0150] In the pre-injection molding method, the first fixing portion 40 is rolled to a folded state after the first insulating member 30 is injection-molded. Therefore, the second insulating portion 34 of the injection-molded first insulating member 30 does not cover the first fixing portion 40 .

[0151] See Figure 3As shown, the integrated injection molding method includes: first, forming the pole 20 using a stamping process; then, the sealing ring 50 is sleeved on the connecting sub-portion 223 of the pole 20, and the connecting sub-portion 223 is inserted into the first through-hole 11 on the cover; then, the pole 20, the sealing ring 50, and the cover plate 10 are loaded into the injection mold as a whole for injection molding, and the first insulating member 30 is injection molded (the flange sub-portion 43 of the first fixing portion 40 has been rolled when the first insulating member 30 is injection molded). During the injection molding process of the first insulating member 30, the pole 20 is pressurized so that the pole 20 compresses the sealing ring 50, that is, the sealing ring 50 maintains a certain amount of compression; after the injection molding is completed, the cover plate 10, the sealing ring 50, the pole 20, and the first insulating member 30 are removed from the injection mold as a whole. At this time, the pressure on the pole 20 disappears, but due to the pressing effect of the flange sub-portion 43 of the first fixing portion 40 on the first insulating member 30, the pole 20 and the first insulating member 30 can remain pressed against the cover plate 10, and the sealing ring 50 can also remain in a compressed state.

[0152] In the one-piece injection molding method, since the flange sub-portion 43 of the first fixing portion 40 has been rolled to a folded state before the first insulating part 30 is injection-molded, the second insulating portion 34 of the injection-molded first insulating part 30 also covers the flange sub-portion 43 and at least part of the vertical edge sub-portion 41 of the first fixing portion 40.

[0153] In some embodiments, the two second connection portions 22 are respectively located on both sides of the first connection portion 21 in the first preset direction. That is, one of the second connection portions 22, the first connection portion 21, and the other second connection portion 22 are spaced apart along the first preset direction (i.e., the width direction of the cover plate 10).

[0154] Of course, the positions of the two second connection portions 22 are not limited to being located on either side of the first connection portion 21; as long as the two second connection portions 22 are arranged along the first predetermined direction, they are sufficient. In other embodiments, the two second connection portions 22 are located on the same side of the first connection portion 21 in the second predetermined direction, where the second predetermined direction coincides with the length of the cover plate 10. Thus, arranging the two second connection portions 22 on the same side of the first connection portion 21 further reduces the width of the pole 20 in the cover plate 10, thereby adapting to narrower cover plates 10.

[0155] The above describes an embodiment in which the pole 20 is installed on the cover plate 10. However, the pole 20 is not limited to being installed on the cover plate 10. In other embodiments, the pole 20 can also be installed on the shell 200. Specifically, the battery cell 1 includes a shell 200, a cell assembly 300, a pole 20 and a first insulating member 30. The shell 200 has a receiving cavity and a first wall as a side wall of the receiving cavity. The first wall has an inner side surface, an outer side surface and a first through hole 11. The inner side surface faces the receiving cavity, and the outer side surface faces away from the receiving cavity. The first through hole 11 passes through the inner side surface and the outer side surface. The cell assembly 300 is accommodated in the receiving cavity of the shell 200 and has at least two pole ears 302 on the side facing the first wall. The pole 20 includes a first connecting portion 21 and at least two second connecting portions 22. The first connecting portion 21 is arranged on the outer side surface of the first wall, and each second connecting portion 22 is connected to the first connecting portion 21 and is arranged along the width direction of the first wall. Each second connection portion 22 is at least partially disposed in the first through hole 11 and is respectively connected to the corresponding tab 302. The first insulating member 30 includes a first insulating portion 31 disposed between the first connection portion 21 and the first wall to form insulation.

[0156] It should be noted that the difference between the embodiment in which the pole 20 is installed on the first wall of the housing 200 and the embodiment in which the pole 20 is installed on the cover 10 is only the different installation position of the pole 20. The other structures are the same and therefore will not be described in detail here.

[0157] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0158] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A top cover assembly, characterized in that: include: A cover plate (10) having a first surface (a1), a second surface (a2) and a first through hole (11); the first surface (a1) and the second surface (a2) are opposite to each other; a direction parallel to the thickness direction of the cover plate (10) and pointing from the first surface (a1) to the second surface (a2) is the direction from the outside to the inside of the top cover assembly; and the first through hole (11) passes through the first surface (a1) and the second surface (a2); A pole (20) comprising at least one first connecting portion (21) and at least two second connecting portions (22), wherein the first connecting portion (21) is located outside the cover plate (10), and each second connecting portion (22) is connected to the first connecting portion (21); each second connecting portion (22) is at least partially disposed within the first through hole (11) and is used to be connected to a pole lug, respectively; the second connecting portion (22) has an outer surface located outside, and at least a portion of the outer surface is located outside the second surface (a2); and The first insulating member (30) includes a first insulating portion (31) arranged between the first connecting portion (21) and the cover plate (10).

2. The top cover assembly according to claim 1, wherein: On a virtual plane perpendicular to the thickness direction of the cover plate (10), the orthographic projection of the first connecting portion (21) does not overlap with the orthographic projection of the first through hole (11), and the orthographic projection of the second connecting portion (22) covers the orthographic projection of the first through hole (11).

3. The top cover assembly according to claim 1 or 2, characterized in that: Each second connecting portion (22) includes a first area (221) and a second area (222) arranged around the first area (221), the second area (222) is connected to the first connecting portion (21), the first area (221) protrudes relative to the second area (222) along the direction from the first surface (a1) to the second surface (a2), and forms a connecting sub-portion (223) that passes through the first through hole (11).

4. The top cover assembly according to claim 3, wherein: One end of the connecting sub-portion (223) away from the second region (222) is a welding end (a3), the welding end (a3) ​​has a welding surface (a4), and the welding end (a3) ​​protrudes from the second surface (a2) of the cover plate (10).

5. The top cover assembly according to claim 4, wherein: The top cover assembly also includes a second insulating member (60), the second insulating member (60) is arranged on the second surface (a2) of the cover plate (10), the welding end (a3) ​​is arranged to pass through the second insulating member (60), and the welding surface (a4) protrudes from the side surface of the second insulating member (60) away from the cover plate (10), or the welding surface (a4) is flush with the side surface of the second insulating member (60) away from the cover plate (10).

6. The top cover assembly according to claim 4, wherein: The distance that the welding end (a3) ​​protrudes from the second surface (a2) along the thickness direction of the cover plate (10) is 0 to 5 mm.

7. The top cover assembly according to claim 4, wherein: The distance between the weld mark on the welding surface (a4) and the edge of the welding surface (a4) is greater than or equal to 1 mm.

8. The top cover assembly according to claim 3, wherein: The first insulating member (30) further includes a second insulating portion (34), and at least a portion of the second insulating portion (34) covers the second region (222).

9. The top cover assembly according to claim 8, wherein: The first insulating portion and the second insulating portion are integrally formed.

10. The top cover assembly according to claim 8, wherein: A first groove (225) is provided on an end surface of the connecting sub-part (223) connected to the second region (222), and the second insulating part (34) also covers the inner wall of the first groove (225).

11. The top cover assembly according to claim 10, wherein: The second insulating portion (34) is recessed toward the first groove (225) to form a pit (341).

12. The top cover assembly according to claim 8, wherein: The top cover assembly (100) further includes a first fixing portion (40), the first fixing portion (40) being connected to the first surface (a1) of the cover plate (10) and pressing against a side of the second insulating portion (34) facing away from the cover plate (10).

13. The top cover assembly according to claim 12, wherein: The first fixing portion (40) extends along a peripheral edge of the second connecting portion (22).

14. The top cover assembly according to claim 13, wherein: The first fixing portion (40) comprises a first arc segment (45), a straight edge segment (47) and a second arc segment (49) which are connected in sequence, and the first arc segment (45) and the second arc segment (49) are both located on the side of the straight edge segment (47) facing the first connecting portion (21); an escape space (a5) is formed between an end of the first arc segment (45) away from the straight edge segment (47) and an end of the second arc segment (49) away from the straight edge segment (47).

15. The top cover assembly according to claim 14, wherein: The central angle of the first arc segment (45) is greater than 90°; and / or The central angle of the second arc segment (49) is greater than 90°.

16. The top cover assembly according to claim 14, wherein: The distance between the end of the first arc segment (45) away from the straight edge segment (47) and the first connecting portion (21) is greater than or equal to 1.4 mm; and / or The distance between the end of the second arc segment (49) away from the straight edge segment (47) and the first connecting portion (21) is greater than or equal to 1.4 mm.

17. The top cover assembly according to claim 12, wherein: The first fixing portion (40) includes a vertical edge portion (41) and a flanged edge portion (43), wherein the vertical edge portion (41) is connected to the first surface (a1) of the cover plate (10), and the flanged edge portion (43) is connected to the vertical edge portion (41) and is bent relative to the vertical edge portion (41) to the side of the second insulating portion (34) facing away from the cover plate (10).

18. The top cover assembly according to claim 17, wherein: An insulating gap (430) is provided between one end of the flanging sub-portion (43) away from the vertical side sub-portion (41) and the second region (222), and a portion of the second insulating portion (34) is filled in the insulating gap (430).

19. The top cover assembly according to claim 17, wherein: The second insulating portion (34) also covers the flange sub-portion and at least a portion of the vertical edge sub-portion; or The second insulating portion (34) does not cover the vertical edge sub-portion (41) and the flanging sub-portion (43).

20. The top cover assembly according to claim 17, wherein: The orthographic projection of the flange sub-portion (43) on the cover plate (10) along the thickness direction of the cover plate (10) is a first orthographic projection, and the orthographic projection of the second connecting portion (22) on the cover plate (10) along the thickness direction of the cover plate (10) is a second orthographic projection; the first orthographic projection and the second orthographic projection partially overlap or do not overlap.

21. The top cover assembly according to claim 1 or 2, characterized in that: The pole (20) further includes a plurality of transition portions (23) corresponding one-to-one to each of the second connection portions (22), and each of the transition portions (23) is connected between the first connection portion (21) and the corresponding second connection portion (22).

22. The top cover assembly according to claim 21, wherein: Each of the transition portions (23) is provided with a through hole (231); each of the second connecting portions (22) includes a first region (221) and a second region (222) arranged around the first region (221); the second region (222) is connected to the first connecting portion (21); the first region (221) protrudes relative to the second region (222) along a direction from the first surface (a1) to the second surface (a2), and forms a connecting sub-portion (223) that passes through the first through hole (11); The first insulating member (30) further includes a second insulating portion (34) and a third insulating portion (32), wherein the second insulating portion (34) at least partially covers the second region (222), the third insulating portion (32) is filled in the through hole (231), and the third insulating portion (32) is connected to the first insulating portion (31) and the second insulating portion (34).

23. The top cover assembly according to claim 22, wherein: The first insulating portion (31), the second insulating portion (34) and the third insulating portion (32) are integrally formed.

24. The top cover assembly according to claim 3, wherein: The top cover assembly (100) further includes a sealing ring (50), the sealing ring (50) including a first sealing portion (51) and a second sealing portion (53), the first sealing portion (51) and the second sealing portion (53) both being sleeved on the connecting sub-portion (223), the first sealing portion (51) being located between the connecting sub-portion (223) and the inner wall of the first through hole (11), and the second sealing portion (53) being located between the second area (222) and the first surface (a1) of the cover plate (10).

25. The top cover assembly according to claim 24, wherein: The first surface (a1) of the cover plate (10) has a first convex strip (13) arranged around the first through hole (11), and the second sealing portion (53) is pressed against the first convex strip (13).

26. The top cover assembly according to claim 24, wherein: The sealing ring (50) further comprises a second convex strip (55), the second convex strip (55) being protrudingly arranged on a side of the second sealing portion (53) facing away from the cover plate (10) and being arranged around the second area (222).

27. The top cover assembly according to claim 26, wherein: The second convex strip (55) is C-shaped, and the opening of the second convex strip (55) faces the first connecting portion (21).

28. The top cover assembly according to claim 1 or 2, characterized in that A second groove (210) is provided on a side of the first connecting portion (21) facing the cover plate (10), and a portion of the first insulating portion (31) is filled in the second groove (210).

29. The top cover assembly according to claim 28, wherein: The second groove (210) is at least partially narrowed gradually or in a step-like manner in a direction from the groove bottom to the groove opening.

30. The top cover assembly according to claim 28, wherein The depth dimension of the second groove (210) is h1, and the thickness dimension of the first connecting portion (21) is H1, and h1 and H1 satisfy: h1=(5% to 50%)H1.

31. The top cover assembly according to claim 1 or 2, characterized in that A third groove (12) is provided on the surface of the cover plate (10) facing the first connecting portion (21), and a portion of the first insulating portion (31) is filled in the third groove (12).

32. The top cover assembly according to claim 31, wherein: The third groove (12) is gradually narrowed or stepped in a direction from the groove bottom to the groove opening.

33. The top cover assembly according to claim 31, wherein: The depth dimension of the third groove (12) is h2, the thickness dimension of the cover plate (10) is H2, and h2 and H2 satisfy: h2=(5% to 50%)H2.

34. The top cover assembly according to claim 1 or 2, characterized in that The first connecting portion (21) has a boss (211) and an annular surface (213) on a side facing away from the cover plate (10); the annular surface (213) is arranged around the boss (211), and the boss (211) is protruded relative to the annular surface (213) in a direction facing away from the cover plate (10); The first insulating member (30) further includes a fourth insulating portion (35), the fourth insulating portion (35) being arranged around the first connecting portion (21) and covering a peripheral edge of the first connecting portion (21); The surface of the fourth insulating portion (35) is flush with the annular surface.

35. The top cover assembly according to claim 1 or 2, characterized in that The second connecting portions (22) are provided in two numbers, and the two second connecting portions (22) are respectively located on both sides of the first connecting portion (21) in a first preset direction, and the first preset direction is the width direction of the cover plate; or Each of the second connecting portions (22) is located on the same side of the first connecting portion (21) in a second preset direction, and the second preset direction is the length direction of the cover plate.

36. A battery cell, characterized in that: It comprises a housing, a battery cell assembly and a top cover assembly (100) according to any one of claims 1 to 35; The shell has a receiving cavity and an opening communicating with the receiving cavity, the cover plate (10) is arranged to cover the opening, the battery cell assembly is arranged in the receiving cavity, and has at least two tabs on a side facing the cover plate (10), and each second connecting portion (22) passes through the first through hole (11) into the receiving cavity and is connected to the corresponding tab.

37. A battery cell, characterized in that: include: The housing has a receiving cavity and a first wall serving as a side wall of the receiving cavity, the first wall having an inner side surface, an outer side surface, and a first through hole, the inner side surface facing the receiving cavity, the outer side surface facing away from the receiving cavity, and the first through hole passing through the inner side surface and the outer side surface; A battery cell assembly is accommodated in the accommodation cavity of the shell and has at least two tabs on a side facing the first wall; A pole, comprising a first connecting portion and at least two second connecting portions, wherein the first connecting portion is provided on the outer surface of the first wall, and each of the second connecting portions is connected to the first connecting portion and arranged along the width direction of the first wall; each of the second connecting portions is at least partially provided in the first through hole and is respectively connected to the corresponding pole lug; and The first insulating member includes a first insulating portion provided between the first connecting portion and the first wall.

38. A battery, characterized in that: Comprising the battery cell as claimed in claim 36 or 37.

39. An electrical device, characterized in that: Includes the battery cell according to claim 36 or 37, or includes the battery according to claim 38.

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