A top cover assembly, a battery cell, a battery, and an electrical device

Abstract

The present application relates to a top cover assembly, a battery cell, a battery and an electrical device. The top cover assembly includes: a cover plate having a first surface, a second surface and a first through hole, the first surface and the second surface facing away from each other, and the first through hole penetrating through the first surface and the second surface; a pole column including a first connecting portion and at least two second connecting portions, the first connecting portion being located on the side of the cover plate having the first surface, each of the second connecting portions being connected to the first connecting portion and arranged along a first preset direction; each second connecting portion being at least partially disposed in the first through hole and being used for respectively connecting to a tab; and a first insulating member including a first insulating portion disposed between the first connecting portion and the cover plate.

Description

Technical Field

[0001] The present application relates to the technical field of new energy, and 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, good rate performance, safety and environmental friendliness, and are important energy products for modern electronic products and electric vehicles. A battery cell is an important component of a battery.

[0003] In the battery cell, there are two technical solutions: with a connecting piece and without a connecting piece. In the technical solution with a connecting piece, the tab of the battery core is connected to the terminal through the connecting piece, so that the terminal serves as the electrode terminal of the battery cell. However, on the one hand, the presence of the connecting piece leads to an increase in the number of parts, increasing the cost of the battery cell; on the other hand, it adds a welding process between the tab and the connecting piece, further increasing the cost of the battery cell.

[0004] In the technical solution without a connecting piece, the terminal is directly connected to the tab. However, due to the limited space on the cover plate, there are restrictions on the position of the terminal, so it is necessary to extend the tab to achieve the direct connection between the terminal and the tab. Extending the tab greatly increases the risk of the tab being inserted into the battery core and the tab being torn. 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 connecting piece and avoid lengthening the tab for the above problems.

[0006] On the one hand, the present application provides a top cover assembly, including:

[0007] A cover plate, having 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 the first surface and the second surface;

[0008] A terminal, including at least one first connecting portion and at least two second connecting portions, the first connecting portion is located on the side of the cover plate having the first surface, each of the second connecting portions is connected to the first connecting portion and is arranged along the first preset direction; each of the second connecting portions at least partially penetrates through the first through hole and is used to be respectively connected to a tab; and

[0009] A first insulating member, including a first insulating portion disposed between the first connecting portion and the cover plate.

[0010] In some of these embodiments, on a virtual plane perpendicular to the thickness direction of the cover plate, the orthographic projection of the first connecting portion does not coincide 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 of these embodiments, each of the second connecting portions includes a first region and a second region arranged around the first region. The second region is connected to the first connecting portion. The first region protrudes relative to the second region in the direction from the first surface to the second surface, and a connecting sub-portion penetrating through the first through hole is formed.

[0012] In some of these embodiments, one end of the connecting sub-portion away from the second region 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 of these embodiments, the top cover assembly further includes a second insulating member. The second insulating member is disposed on the second surface of the cover plate. The welding end penetrates through the second insulating member, and the welding surface protrudes from a surface of the second insulating member away from the cover plate, or the welding surface is flush with a surface of the second insulating member away from the cover plate.

[0014] In some of these embodiments, the distance by which the welding end protrudes from the second surface in the thickness direction of the cover plate is 0 - 5 mm.

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

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

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

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

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

[0020] In some of these embodiments, the top cover assembly further includes a first fixing portion. The first fixing portion is connected to the first surface of the cover plate and presses against a side of the second insulating portion 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 escape 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 center 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 flanged edge sub-portion, the standing edge sub-portion is connected to the first surface of the cover plate, the flanged edge 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 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 edge 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 also covers the flange sub-portion and at least a portion of the vertical edge sub-portion; or

[0030] The second insulating portion does not cover the standing edge sub-portion and the flange 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 partially overlaps or does not overlap with the second orthographic projection.

[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 of these embodiments, each of the transition portions is provided with a second through hole; each of the second connecting portions includes a first region and a second region arranged around the first region, the second region is connected to the first connecting portion, and the first region protrudes relative to the second region in a direction from the first surface to the second surface, and a connecting sub-portion penetrating through the first through hole is formed;

[0034] The first insulating member further includes a second insulating portion and a third insulating portion. At least a part of the second insulating portion covers the second region, the third insulating portion is filled in the second through hole, and the third insulating portion is connected to the first insulating portion and the second insulating portion.

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

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

[0037] In some of these embodiments, a first rib is provided on the first surface of the cover plate and is disposed around the first through hole, and the second sealing portion is pressed against the first rib.

[0038] In some of these embodiments, the sealing ring further includes a second rib, the second rib protrudes from a side of the second sealing portion facing away from the cover plate and is arranged around the second region.

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

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

[0041] In some of these embodiments, the second groove is at least partially gradually narrowed or stepwise narrowed in a direction from the groove bottom to the groove opening.

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

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

[0044] In some of these embodiments, the third groove gradually narrows or stepwise narrows in the direction from the groove bottom to the groove opening.

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

[0046] In some of these embodiments, a boss and an annular surface are provided on the side of the first connecting portion facing away from the cover plate, the annular surface surrounds the boss, and the boss protrudes in a direction away from the cover plate relative to the annular surface;

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

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

[0049] In some of these embodiments, the second connecting portion is provided in two, and the two second connecting portions are respectively located on both sides of the first connecting portion in the first preset direction; or

[0050] Each of the second connecting portions is located on the same side of the first connecting portion in the second preset direction, and the first preset direction is perpendicular to the second preset direction.

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

[0052] The housing has a receiving cavity and an opening communicating with the receiving cavity, the cover plate is disposed at the opening, the battery cell assembly is disposed in the receiving cavity, and at least two tab ears are provided on the side facing the cover plate, and a part of each second connecting portion passing through the first through hole into the receiving cavity is connected to the corresponding tab ear.

[0053] On the other hand, the present application provides a battery cell, including:

[0054] A housing having 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 penetrating 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 connection portion and at least two second connection portions, wherein the first connection portion is arranged on the outer side of the first wall, each of the second connection portions is connected to the first connection portion and arranged along the width direction of the first wall; each of the second connection portions is at least partially passed through the first through hole and is respectively connected to the corresponding pole lug; and

[0057] The first insulating member includes a first insulating portion disposed 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 a battery cell as described in any of the above embodiments, or including a battery as described in any of the above embodiments.

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

[0061] In 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, which avoids the use of adapters on the one hand, 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 holes 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 into the battery cell and the pole ear being torn. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 A cross-sectional view of a battery cell at a pole in an 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 An exploded structural diagram 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 is Figure 2 a schematic structural view of the terminal post of the top cover assembly shown;

[0067] Figure 6 is Figure 5 a cross-sectional view of the terminal post shown (the cross-section is perpendicular to the length direction of the cover plate);

[0068] Figure 7 is Figure 2 a schematic structural view of the sealing ring of the top cover assembly shown;

[0069] Figure 8 is Figure 2 a schematic structural view of the cover plate of the top cover assembly shown;

[0070] Figure 9 is Figure 2 a schematic structural view of the first insulating part of the top cover assembly shown;

[0071] Figure 10 is a cross-sectional view of the top cover assembly at the terminal post in another embodiment of the present application (the cross-section is perpendicular to the length direction of the cover plate). Detailed implementation manners

[0072] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the detailed implementation manners of the present application in conjunction with the accompanying drawings. Many specific details are set forth in the following description to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0073] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present application.

[0074] In addition, 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 quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0075] In this application, unless otherwise clearly specified and defined, terms such as "installed", "connected", "linked", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0076] In this application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0077] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it may be directly on the other element or there may also 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 at the same time. 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.

[0078] An 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 powered by the above-mentioned battery or battery cell. Among them, 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, a amusement device, an elevator, a lifting device, and so on. Electric toys include stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, or electric aircraft 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 electric drills, concrete vibrators, and electric planers, etc.; Energy storage devices can be energy storage walls, base station energy storage, container energy storage, etc.; Amusement devices can be carousels, drop towers, etc.

[0079] The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or an extended-range electric vehicle, etc.; For new energy vehicles, the above-mentioned battery can be used as a drive power source to replace fossil fuels to provide driving power. The present application does not impose special restrictions on the above-mentioned 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 communicate with the battery management system. The battery management system controls and monitors the working states of the individual battery cells. In addition, the plurality of battery cells can also first form a battery module with a module management system, and then a plurality of battery modules are electrically connected in series, in parallel, or in a combination of series and parallel, and jointly constitute a battery pack with the battery management system.

[0081] Multiple battery cells can be installed on support structures such as boxes, frames, and brackets. Electrical connections can be made between the individual battery cells and between the battery cells and the battery management system through electrical connectors, which can be busbars. In addition, electrical connections can also be achieved by plugging the respective terminal posts between the individual battery cells. For example, between two adjacent battery cells, a slot is provided on the terminal post of one battery cell, and a plug is correspondingly provided on the terminal post of the other battery cell. The plug is inserted into the slot to achieve the electrical connection. Therefore, for one battery cell, the aforementioned electrical connector can be the terminal post of another battery cell. Similarly, electrical connections can also be achieved by mutual plugging between the battery cell and the battery management system, which will not be elaborated here. The above-mentioned battery cells can be lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, and their external contours can be cylindrical, flat, cuboid, or other shapes, but are not limited thereto. Specifically, in this embodiment, the above-mentioned battery cell is a lithium-ion square battery.

[0082] Referring to Figure 1 , the above-mentioned battery cell 1 includes a housing 200, a core component 300, and a top cover component 100. The housing 200 is provided with an opening at at least one end, and there is a receiving cavity inside the housing 200, and the receiving cavity communicates with the opening. The core component 300 is received in the receiving cavity of the housing 200, and the top cover component 100 covers the opening of the housing 200, thereby enclosing the core component 300 in the receiving cavity of the housing 200. The core component 300 includes at least two groups of cores 301 arranged in parallel along the thickness direction of the housing 200, and each group of cores 301 extends a tab 302 towards the end face of the top cover component 100.

[0083] It should be noted that each group of cores 301 can be one core 301 or multiple cores 301, which is not limited here. When each group of cores 301 includes one core 301, a positive tab and a negative tab extend from the end face of this core 301 towards the top cover component 100. When each group of cores 301 includes multiple cores 301, positive tabs and negative tabs extend from the end faces of each core 301 towards the top cover component 100. The positive tabs on each core 301 in the same group are joined together to form a single positive tab, and the negative tabs on each core 301 in the same group are joined together to form a single negative tab.

[0084] As an implementation manner, the core component 300 includes two groups of cores 301, and each group of cores 301 includes one core 301. That is to say, the core component 300 includes a total of two cores 301, and the two cores 301 are arranged in parallel along the thickness direction of the housing 200. The positive tab on the end face of one core 301 towards the top cover component 100 serves as one positive tab, and the negative tab serves as one negative tab; the positive tab on the end face of the other core 301 towards the top cover component 100 serves as another positive tab, and the negative tab serves as another negative tab.

[0085] In the related art, a connecting piece is used to connect each positive electrode tab to the positive electrode post on the top cover assembly. However, the presence of the connecting piece increases the number of parts on the one hand, resulting in an increase in the cost of the battery cell, an increase in the internal resistance value of the battery cell, and a decrease in the energy efficiency of the battery cell; on the other hand, it adds a welding process for the electrode tab and the connecting piece, further increasing the cost of the battery cell. To overcome the above defects, a technical solution without a connecting piece has been applied.

[0086] In the technical solution without a connecting piece, the positive electrode post on the top cover assembly directly extends into the accommodating cavity and is directly connected to the positive electrode tabs of each group of battery cells. However, since each group of battery cells is arranged in the thickness direction of the housing, the positive electrode tabs of each group of battery cells are also arranged in the thickness direction of the housing. Since the span of each positive electrode tab in the thickness direction of the housing is relatively large, the positive electrode tab needs to be arranged in the middle in the thickness direction of the housing. Therefore, a conventional-sized positive electrode post cannot take into account direct connection with each positive electrode tab. Therefore, in order to directly connect the positive electrode post to each positive electrode tab, one way is to increase the radial dimension of the electrode post, so that the electrode post is as close as possible to the positive electrode tabs on both sides in the thickness direction of the housing, ensuring that each positive electrode tab can be directly connected to the positive electrode post; another way is to extend the length of the positive electrode tab, so that each positive electrode tab extends to the positive electrode post and is directly connected to the positive electrode post.

[0087] However, the inventors of the present application found in long-term research and development that in the solution of increasing the radial dimension of the electrode post, as the radial dimension of the electrode post increases, the material cost of the electrode post increases, and the size of the mounting hole for mounting the electrode post is large, resulting in insufficient strength of the cover plate of the top cover assembly. In the solution of extending the length of the positive electrode tab, there is a risk of the positive electrode tab being inserted inversely into the battery cell and the positive electrode tab being torn. It should be noted that the negative electrode post and the negative electrode tab are directly connected and also have the above defects, which will not be elaborated here.

[0088] To overcome the above defects, the inventors of the present application creatively proposed an electrode post capable of directly connecting the electrode post and the electrode tab. In the technical solution of the present application, the electrode post is formed by stamping a sheet (such as upsetting, drawing, and cutting, etc.). The electrode post includes a first connecting portion and at least two second connecting portions connected to the first connecting portion. 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 housing 200. That is to say, the arrangement directions of the second connecting portions are the same as those of each group of battery cells 301, so that each second connecting portion is opposite to the electrode tab 302 of each group of battery cells 301 one by one. Thus, the electrode tab 302 of each group of battery cells 301 is directly connected to its corresponding second connecting portion, thereby avoiding the need to increase the radial dimension of the electrode post or extend the length of the electrode tab 302, and further overcoming the defects brought about by increasing the radial dimension of the electrode post and extending the electrode tab 302.

[0089] The specific structure of the top cover assembly will be described in detail below with reference to the accompanying drawings. Please refer to 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 terminal post 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 face away from each other in the thickness direction of the cover plate 10, and the first through hole 11 penetrates through the first surface a1 and the second surface a2 of the cover plate 10. The cover plate 10 is disposed on the opening of the housing 200 to seal the opening of the housing 200. The first surface a1 of the cover plate 10 faces away from the battery cell assembly 300 in the receiving cavity of the housing 200, and the second surface a2 of the cover plate 10 faces the battery cell assembly 300 in the receiving cavity of the housing 200. The thickness direction of the above-mentioned housing 200 is consistent with the above-mentioned first preset direction, that is, the two groups of battery cells 301 of the battery cell assembly 300 in the housing 200 are arranged side by side in the first preset direction. Therefore, the tabs 302 of the two groups of battery cells 301 are also arranged at intervals in the first preset direction.

[0090] The terminal post 20 is disposed on the cover plate 10, and the thickness direction of the terminal post 20 is consistent with the thickness direction of the cover plate 10. A positive terminal post and a negative terminal post can be provided on the cover plate 10. The positive terminal post is used to connect to the positive tabs of each group of battery cells 301, so as to lead out the positive tabs of each group of battery cells 301 to the outside of the housing 200; the negative terminal post is used to connect to the negative tabs of each group of battery cells 301, so as to lead out the negative tabs of each group of battery cells 301 to the outside of the housing 200. The positive terminal post serves as the positive terminal of the battery cell 1, and the negative terminal post serves as the negative terminal of the battery cell 1. And electrical connectors are used to connect the positive terminals and negative terminals of each battery cell 1 to achieve electrical connection in series, parallel, or a combination of series and parallel of each battery cell 1.

[0091] It should be noted that since the structures of the positive terminal post and the negative terminal post are similar, for the convenience of understanding, one of the terminal posts 20 is taken as an example for description in this article. That is to say, the "terminal post" in this article can be either a positive terminal post or a negative terminal post (except in the case where it is clearly stated), and the "tab" in this article can be either a positive tab or a negative tab (except in the case where it is clearly stated), as long as it is ensured that all the tabs 302 connected to the positive terminal post are positive tabs, and all the tabs 302 connected to the negative terminal post are negative tabs.

[0092] Specifically, the terminal post 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 a first surface a1, 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 to say, 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 part of each second connection portion 22 penetrates through a first through hole 11 in the cover plate 10 and is used to be respectively connected to the corresponding tab 302, that is to say, 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] For the above-mentioned top cover assembly 100, the terminal post 20 is directly connected to the tabs 302 of the two groups of battery cells 301 through the two second connection portions 22. On the one hand, the use of adapter plates is avoided, thereby reducing the number of components of the top cover assembly 100 and reducing a welding process; on the other hand, by arranging the two second connection portions 22 along the arrangement direction of the two groups of battery cells 301, the two second connection portions 22 pass through the cover plate 10 through the first through holes 11 in the cover plate 10 and are respectively connected to the tabs 302 of the two groups of battery cells 301, avoiding the need to increase the radial dimension of the terminal post 20 and the need to extend the tabs 302, thereby avoiding increasing the material cost of the tabs 302 and increasing the risk of adverse phenomena such as the tabs 302 being inserted reversely into the battery cells and the tabs 302 being torn.

[0094] It can be understood that the number of the second connection portions 22 is not limited to two, and can also be three or more. The number of the second connection portions 22 is related to the number of groups of battery cells. Specifically, when the number of groups of battery cells is N groups, the number of the second connection portions 22 is also set to N. The N second connection portions 22 are arranged at intervals along the first preset direction and are all connected to the first connection portion 21. The N second connection portions 22 respectively penetrate through the first through holes 11 in the cover plate 10 and are connected to the tabs 302 of each group of battery cells 301 in a one-to-one correspondence, so as to lead out the tabs 302 of the respective corresponding battery cells 301 to the first connection portion 21. For the sake of easy understanding, in this article, an example is given in which the battery cell assembly 300 includes two groups of battery cells 301 and the terminal post 20 includes two second connection portions 22.

[0095] It should also be noted that the number of the first connection portions 21 is not limited to one, and can also be two or more. The number of the first connection portions 21 is related to the number of the second connection portions 22. One first connection portion 21 is arranged between two adjacent second connection portions 22. At this time, the number of the first connection portions 21 is N - 1. For example, when the number of the second connection portions 22 is 3 and the number of the first connection portions 21 is 2, the terminal post 20 includes, along the first preset direction, the second connection portion 22, the first connection portion 21, the second connection portion 22, the first connection portion 21, and the second connection portion 22 that are connected in sequence.

[0096] In one embodiment, a first through hole 11 may be disposed on the cover plate 10 . The first through hole 11 is a hole with a relatively large area and can allow at least two second connection portions 22 to pass through the first through hole 11 .

[0097] It can be understood that, in another embodiment, a first through hole 11 is provided at a position corresponding to each second connection portion 22 on the cover plate 10, so that each second connection portion 22 is respectively penetrated in the first through hole 11 corresponding to each of them, and then respectively connected to the corresponding pole lug 302. In this way, compared with the first through hole 11 in which the pole is integrally mounted on the cover plate 10, in this embodiment, only the first through hole 11 matching the outer contour size of the second connection portion 22 needs to be provided, which 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 can meet the requirements.

[0098] See also Figures 4 to 6 As 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. The first area 221 protrudes from 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 penetrates 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 by a stamping process, so that the first area 221 protrudes toward the cover plate 10 relative to the second area 222 to form a connection sub-portion 223. The connection sub-portion 223 extends to the pole ear 302 of the corresponding battery cell group through the corresponding first through hole 11, and is directly connected to the pole ear 302.

[0099] Furthermore, one end of the connecting sub-portion 223 away from the second region 222 is a welding end a3, and the welding end a3 passes through the corresponding first through hole 11 and enters the receiving cavity of the shell 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 electrode tab 302 and 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 of the electrode tab 302 and the connecting sub-portion 223.

[0100] 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 too far from the second surface a2, that is, saving space in the receiving cavity of the shell 200, which is beneficial to improving the energy density of the battery.

[0101] Further, the top cover group 100 further includes a second insulating member 60, which is disposed 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 passes through the corresponding first through hole 11 and the third through hole. The welding end a3 of the connecting sub - portion 223 has a welding surface a4, and the welding surface a4 protrudes from the surface of the second insulating member 60 away from the cover plate 10, or the welding surface a4 is flush with the surface of the second insulating member 60 away from the cover plate 10. In this way, the welding of the tab 302 and the welding surface a4 of the connecting sub - portion 223 inside the third through hole is avoided, greatly reducing the welding difficulty and being beneficial to improving the welding quality of the welding surface a4 between the tab 302 and the connecting sub - portion 223.

[0102] It should be noted that welding processes such as laser welding, resistance welding, ultrasonic welding, and pressure fusion welding can be used to realize the welding of the connecting sub - portion 223 and the tab 302.

[0103] As an embodiment, the tab 302 is welded and fixed to the connecting sub - portion 223 by pressure fusion welding. Specifically, a protrusion 227 is provided on the welding surface a4 of the connecting sub - portion 223. During pressure fusion welding, the tab 302 contacts the protrusion 227. Since the current - carrying area at the contact between the tab 302 and the protrusion 227 is small, more heat is generated, causing the protrusion 227 to melt and weld the tab 302 to the welding surface a4 of the connecting sub - portion 223. It can be understood that the shape of the protrusion 227 can be spherical, hemispherical, frustum - shaped, etc., as long as it can ensure that the protrusion 227 can melt under the action of electric energy and pressure to weld the tab 302 to the welding surface a4 of the connecting sub - portion 223, and no special limitation is made here.

[0104] As another embodiment method, the tab 302 is welded and fixed to the connecting sub - portion 223 by laser welding. Specifically, the distance between the welding 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. Optionally, the distance between the welding 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., and no special limitation is made here.

[0105] It should be noted that the distance between the welding mark on the welding surface a4 and the edge of the welding surface a4 refers to the distance between any point on the edge of the welding surface a4 and any point on the edge of the welding mark.

[0106] Specifically in the embodiment, one end face of the connecting sub - part 223 connected to the second region 222 has a first groove 225, making the connecting sub - part 223 a hollow structure, which is beneficial to reducing the weight of the pole column 20 and saving the material of the pole column 20. It can be understood that during one or more deep - drawing processes of the sheet, the first region 221 of the sheet bulges outward as a whole relative to the second region 222 to one side, thus forming the hollow connecting sub - part 223.

[0107] Optionally, the depth dimension of the first groove 225 is 1 mm to 5 mm, preferably 1 mm to 3 mm. In this way, if the depth of the first groove 225 is too shallow, the welding end a3 of the connecting sub - part 223 will be far from the battery cell assembly 300, and a longer tab 302 is required; if the depth of the first groove 225 is too deep, the deep - drawing process will be more difficult. In this embodiment, by reasonably designing the depth dimension of the first groove 225, the depth dimension of the first groove 225 is made appropriate, which can not only realize the welding of the tab 302 and the welding end a3 of the connecting sub - part 223 without lengthening the tab 302, but also reduce the deep - drawing process difficulty, improve the production efficiency and the yield of the pole column 20.

[0108] It should be noted that the depth dimension 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 no special limitation is made here.

[0109] In the embodiment of the present application, the pole column 20 further includes a transition part 23. The second region 222 of each second connecting part 22 is connected to the first connecting part 21 through the transition part 23. One end of the transition part 23 connected to the second region 222 of the second connecting part 22 is the first end, and at least part of the first end protrudes from the surface of the first connecting part 21 facing the cover plate 10 along the thickness direction of the pole column 20. That is to say, the transition part 23 extends obliquely along the thickness direction of the pole column 20 from the end connected to the first connecting part 21 to the end connected to the second region 222, so that the second connecting part 22 sinks as a whole relative to the first connecting part 21 towards the cover plate 10, and further makes the connecting sub - part 223 closer to the corresponding tab 302, which is beneficial to reducing the deep - drawing depth of the connecting sub - part 223 as much as possible, reducing the deep - drawing difficulty and improving the deep - drawing quality of the pole column 20.

[0110] Furthermore, the cross-sectional area of the current-carrying portion 23 is smaller than that of the first connecting portion 21 and smaller than that of the second connecting portion 22. In this way, when an abnormality occurs in the circuit during actual use, due to the smaller cross-sectional area of the current-carrying portion 23, the temperature at the current-carrying portion 23 rises faster, and the current-carrying portion 23 can be quickly melted to cut off the circuit in a timely manner, greatly improving the safety of the battery. It can be understood that the cross-sectional area of the current-carrying portion 23 can be reduced by means of grooving, punching, and / or local thinning to ensure that the circuit can be cut off by melting in a timely manner when the circuit is abnormal.

[0111] In an embodiment of the present application, the top cover assembly 100 further includes a first insulating member 30, and the first insulating member 30 includes a first insulating portion 31. The first insulating portion 31 is disposed between the first connecting portion 21 of the pole column 20 and the cover plate 10 to form insulation, that is, to prevent the first connecting portion 21 of the pole column 20 from being electrically connected to the cover plate 10.

[0112] Furthermore, the first insulating member 30 further includes a second insulating portion 34, and the second insulating portion 34 covers the second region 222 of the pole column 20. On the one hand, it provides insulation protection for the outer surface of the second region 222, and on the other hand, it wraps the second region 222 of the pole column 20, which is beneficial to increasing the overall strength of the pole column 20 and reducing the risk of deformation of the pole column 20.

[0113] Furthermore, the second insulating portion 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, and on the other hand, it is beneficial to increasing the bonding force between the second insulating portion 34 and the second connecting portion 22, greatly reducing the risk of the second insulating portion 34 and the second connecting portion 22 being displaced or even separated.

[0114] Furthermore, the second insulating portion 34 is recessed toward the first groove 225 to form a pit 341. That is to say, 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 improving the bonding force between the second insulating portion 34 and the second connecting portion 22 of the pole column 20 and preventing the second insulating portion 34 from being separated or misaligned with the second connecting portion 22; on the other hand, it reduces the material consumption of the second insulating portion 34 and avoids defects such as uneven injection molding due to local excessive thickness.

[0115] Furthermore, the second insulating portion 34 also extends to each transition portion 23 and covers each transition portion 23, thereby providing insulation protection for the surface of the transition portion 23. The first insulating member 30 further 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, which is beneficial to improving the overall strength of the terminal post 20 and providing insulation protection for the peripheral edge of the first connecting portion 21. That is to say, the 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 surface of the first connecting portion 21 facing away from the cover plate 10 is not covered, and this uncovered surface is used for welding with the electrical connector.

[0116] Specifically in the embodiment, the side of the first connecting portion 21 facing away from the cover plate 10 has a boss 211 and an annular surface 213. The annular surface 213 is arranged around the boss 211, and the boss 211 protrudes relative to the annular surface 213 in the 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 the annular surface 213 or flush with the annular surface 213. In this way, by providing the boss 211, the injection molding material can be blocked from flowing onto the surface of the boss 211 during injection molding, which may cause the first insulating member 30 to cover the surface of the boss 211.

[0117] Optionally, the protruding 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 protruding 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, 0.8 mm, etc., and no special limitation is made here.

[0118] Specifically in the embodiment, at least one second through hole 231 is formed in the transition portion 23, and the first insulating member 30 further includes a third insulating portion 32 filled in 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, so that the first insulating portion 31, the second insulating portion 34, the third insulating portion 32, and the fourth insulating portion 35 form an integral body. On the one hand, it is beneficial to improve the bonding force between the first insulating member 30 and the terminal post 20; on the other hand, it is beneficial to further enhance the overall strength of the terminal post 20.

[0119] Further, the first insulating part 31, the second insulating part 34, the third insulating part 32, and the fourth insulating part 33 of the first insulating member 30 are integrally formed, for example, by an injection molding process. When the first insulating member 30 is injection molded, a part of the molten injection material flows to the surfaces of the respective second connecting parts 22 and the respective transition parts 23, and after curing, the second insulating part 34 is formed; a part of the molten injection material flows to the surface of the peripheral edge of the first connecting part 21, and after curing, the fourth insulating part 35 is formed; a part of the injection material flows into the second through hole 231, and after curing, the third insulating part 32 is formed; a part of the injection material flows through the second through hole 231 into the space between the first connecting part 21 and the cover plate 10, and after curing, the first insulating part 31 is formed between the first connecting part 21 and the cover plate 10.

[0120] It should be noted that the second through hole 231 in the transition part 23 serves to circulate the injection material during injection molding on the one hand, and on the other hand, also serves to reduce the current-carrying area of the transition part 23, ensuring that the transition part 23 can be melted and cut off the circuit in time in case of an abnormality.

[0121] Please also refer to Figure 7 As shown, specifically in the embodiment, the top cover assembly 100 further includes a first fixing part 40. The first fixing part 40 is fixedly connected to the first surface a1 of the cover plate 10, and a part of the first fixing part 40 can be bent to the surface of the second insulating part 34 facing away from the cover plate 10 by a hemming process, so as to press the second insulating part 34 and the pole column 20 against the cover plate 10 by using the first fixing part 40, preventing the pole column 20 from detaching from the cover plate 10.

[0122] Further, the second insulating part 34 has a stepped surface a6 extending along the peripheral edge of the second region 222 of the second connecting part 22. The first fixing part 40 extends along the peripheral edge of the second connecting part 22 and presses against the stepped surface a6, making the pressing of the first fixing part 40 on the second insulating part 34 more stable, and further making the assembly structure of the pole column 20 and the cover plate 10 more stable, preventing the pole column 20 from being displaced or even detaching from the cover plate 10.

[0123] It should be noted that the number of the first fixing parts 40 is the same as the number of the second connecting parts 22, and the two are arranged in a one-to-one correspondence. Each first fixing part 40 presses against the second insulating part 34 on the surface of the corresponding second connecting part 22, so that each second connecting part 22 of the pole 20 is pressed against the cover plate 10. Optionally, each first fixing part 40 extends along the peripheral edge of the corresponding second connecting part 22 in a C-shape, and the opening of the C-shaped first fixing part 40 faces the first connecting part 21, so that the transition part 23 passes through the opening of the first fixing part 40, avoiding the fourth insulating part 35 covering the peripheral edge of the first connecting part 21 and the second insulating part 34 covering the transition part 23 from interfering with the rolling equipment when the first fixing part 40 is rolled.

[0124] Specifically, the first fixing portion 40 includes a first arc segment 45, a straight edge segment 47, and a second arc segment 49 that are sequentially connected, 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. It can be understood that the escape space a5 is the space at the opening of the C-shaped first fixing portion 40.

[0125] Optionally, the central angle of the first arc segment 45 is greater than 90°, which is beneficial to extend the length of the first fixing portion 40 so that the first fixing portion 40 can more stably press the second insulating portion 34 and the second connecting portion 22 onto the cover plate 10 .

[0126] Optionally, the central angle of the second arc segment 49 is greater than 90°, which is beneficial to extend the length of the first fixing portion 40 so that the first fixing portion 40 can more stably press the second insulating portion 34 and the second connecting portion 22 onto the cover plate 10 .

[0127] It should be noted that in order to improve the clamping effect, it is necessary to extend the length of the first fixing portion 40 as much as possible. However, extending the length of the first fixing portion 40 will cause the first arc segment 45 and / or the second arc segment 49 to be too close to the end away from the straight edge segment 47 and the first connecting portion 21, thereby causing the fourth insulating portion 35 wrapped around the peripheral edge of the first connecting portion 21 to interfere with the rolling equipment when the first fixing portion 40 is rolled.

[0128] In order to avoid interference between the fourth insulating portion 35 wrapped around the peripheral edge of the first connecting portion 21 and the hemming equipment when the first arc segment 45 is hemmed. 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 when the first arc segment 45 is hemmed, the fourth insulating portion 35 on the peripheral edge of the first connecting portion 21 will not interfere with the hemming equipment.

[0129] 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 may be 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm or 1.8 mm, etc., which is not particularly limited herein.

[0130] In order to avoid interference between the fourth insulating portion 35 wrapped around the peripheral edge of the first connection portion 21 and the hemming equipment when the second arc segment 49 is hemmed. In some embodiments, the distance between the end of the second arc segment 49 away from the straight edge segment 47 and the first connection 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 connection portion 21 is large enough to ensure that when the second arc segment 49 is hemmed, the fourth insulating portion 35 on the peripheral edge of the first connection portion 21 will not interfere with the hemming equipment.

[0131] 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 may be 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm or 1.8 mm, etc., which is not particularly limited herein.

[0132] Specifically in the embodiment, the first fixing portion 40 includes a vertical edge sub-portion 41 and a flanged edge sub-portion 43. The vertical edge sub-portion 41 is connected to the first surface a1 of the cover plate 10. The flanged edge sub-portion 43 is connected to the vertical edge sub-portion 41, and the flanged edge sub-portion 43 is bent relative to the vertical edge sub-portion 41 to the step surface a6 of the second insulating portion 34, so that the flanged edge sub-portion 43 is used to press the second insulating portion 34, thereby realizing the first insulating member 30 and the pole 20 being pressed and fixed on the cover plate 10.

[0133] Furthermore, an insulating gap 430 is formed between the end of the flange sub-portion 43 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 is filled in the insulating gap 430, thereby achieving insulation between the flange sub-portion 43 and the second region 222 of the second connecting portion 22.

[0134] In order to more firmly press the second connecting portion 22 against the cover plate 10, in some embodiments, the orthographic projection of the flanging sub-portion 43 on the cover plate 10 in the thickness direction of the cover plate 10 is the first orthographic projection, and the orthographic projection of the second connecting portion 22 on the cover plate 10 in the thickness direction of the cover plate 10 is the second orthographic projection. The first orthographic projection of the flanging sub-portion 43 coincides with a part of the second orthographic projection of the second connecting portion 22, that is to say, there is an overlapping part between the flanging sub-portion 43 and the second connecting portion 22 in the thickness direction of the cover plate 10.

[0135] In other embodiments, the first orthographic projection of the flanging sub-portion 43 does not coincide with the second orthographic projection of the second connecting portion 22, that is to say, there is no overlapping part between the flanging sub-portion 43 and the second connecting portion 22 in the thickness direction of the cover plate 10.

[0136] It should also be noted that since each second connecting portion 22 is pressed against the cover plate 10 through the first fixing portion 40, and the connection between the first connecting portion 21 and the cover plate 10 is weak, it will cause uneven stress on the pole column 20, resulting in warping or even cracking. In order to avoid warping or cracking of the pole column 20 due to uneven stress, in some embodiments, a second groove 210 is formed on the surface of the first connecting portion 21 facing the cover plate 10, and a third groove 12 is formed on the surface of the cover plate 10 facing the first connecting portion 21. A part of the first insulating portion 31 is filled in the second groove 210, and a part of the first insulating portion 31 is also filled in the third groove 12. In this way, when the first insulating member 30 is injection-molded, the molten injection material can flow into the second groove 210 and the third groove 12, and after curing, a structure in which a part of the first insulating portion 31 is filled in the second groove 210 and the third groove 12 is formed, which is beneficial to improving the bonding force among the first connecting portion 21, the first insulating portion 31, and the second connecting portion 22.

[0137] Furthermore, at least a part of the second groove 210 gradually narrows or narrows in a stepped manner from the groove bottom to the groove opening, so that the first insulating portion 31 is tightly nested on the pole column 20 through the second groove 210, preventing the pole column 20 from separating from the first insulating member 30. At least a part of the third groove 12 gradually narrows or narrows in a stepped manner from the groove bottom to the groove opening, so that the first insulating portion 31 is 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.

[0138] Optionally, the depth dimension of the second groove 210 is h1, the thickness dimension of the first connection part 21 is H1, and h1 and H1 satisfy: h1=(5%~50%)×H1. Preferably, h1 and H1 satisfy: h1=(10%~20%)×H1. In this way, by designing the depth of the second groove 210 within a suitable range, on the one hand, it is avoided that the depth of the second groove 210 is too shallow, resulting in the effect of increasing the bonding force between the first insulating part 31 and the first connection part 21 is not obvious; on the other hand, it is avoided that the depth of the second groove 210 is too deep, resulting in the first connection part 21 The strength is low and easy to deform. 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.

[0139] It should be noted that the number of the second grooves 210 can be one or more, and is not particularly limited here. When the number of the second grooves 210 is one, the second grooves 210 themselves are arranged symmetrically relative to the center line of the first connecting portion 21, so as to avoid the pole 20 from warping or cracking due to uneven force. When the number of the second grooves 210 is more than one, the multiple second grooves 210 are arranged symmetrically relative to the center line of the first connecting portion 21, so as to avoid the pole 20 from warping or cracking due to uneven force.

[0140] Optionally, 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%~50%)H2. Preferably, h2 and H2 satisfy: h2=(10%~20%)×H2. In this way, by designing the depth of the third groove 12 within a suitable range, on the one hand, the depth of the third groove 12 is avoided to be too shallow, resulting in the effect of increasing the bonding force between the first insulating part 31 and the cover plate 10 is not obvious; on the other hand, the depth of the third groove 12 is avoided to be too deep, resulting in the cover plate 10 being weak in strength and easy to deform. 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., and is not specifically limited here.

[0141] It should be noted that the number of the third grooves 12 can be one or more, and is not particularly limited here. When the number of the third grooves 12 is one, the third grooves 12 themselves are arranged symmetrically relative to the center line of the cover plate 10 to avoid defects such as warping or cracking of the cover plate 10 due to uneven force. When the number of the third grooves 12 is more than one, the multiple third grooves 12 are arranged symmetrically relative to the center line of the cover plate 10 to avoid defects such as warping or cracking of the cover plate 10 due to uneven force.

[0142] Please refer to Figure 3 、 Figure 6 and Figure 7 As shown, specifically in the embodiment, the top cover assembly 100 further includes a sealing ring 50, and the sealing ring 50 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 on the connecting sub-portion 223, and the first sealing portion 51 is located between the inner wall of the first through hole 11 and the connecting sub-portion 223, and the second sealing portion 53 is located between the surface of the cover plate 10 facing away from the battery cell assembly 300 and the second region 222. In this way, on the one hand, the sealing ring 50 is used to seal the first through hole 11 on the cover plate 10 to prevent the electrolyte in the housing 200 from leaking out through the first through hole 11; on the other hand, the sealing ring 50 is used to form insulation between the connecting sub-portion 223 and the second region 222 and the cover plate 10 to prevent the pole column 20 from being electrically connected to the cover plate 10. It should be noted that under the pressing action of the flanging sub-portion 43, the first sealing portion 51 and the second sealing portion 53 of the sealing ring 50 are in a compressed state, so as to realize the sealing of the first through hole 11.

[0143] Further, a first rib 13 is provided on the first surface a1 of the cover plate 10 and surrounds the first through hole 11. The second sealing portion 53 presses against the first rib 13, which is beneficial to increasing the contact area between the sealing ring 50 and the cover plate 10, extending the sealing path, and improving the sealing effect.

[0144] It should be noted that providing the first rib 13 on the first surface a1 of the cover plate 10 and surrounding the first through hole 11 can also play a role in strengthening the area of the cover plate 10 near the first through hole 11, greatly reducing the risk of deformation or warping of the cover plate 10.

[0145] Further, the sealing ring 50 further includes a second rib 55. The second rib 55 protrudes from the side of the second sealing portion 53 facing away from the cover plate 10 and is arranged around the second region 222. That is to say, the second sealing portion 53 contacts the entire surface of the second region 222 facing the cover plate 10, and the second rib 55 on the second sealing portion 53 also extends to the end surface of the second region 222, which is beneficial to further improving the sealing effect.

[0146] Further, the second rib 55 extends along the circumferential edge of the second region 222 in a C shape, and the opening of the second rib 55 faces the first connecting portion 21. In this way, since the second region 222 of the second connecting portion 22 is connected to the first connecting portion 21 through the transition portion 23, the second rib 55 is set in a C shape, and the space at the opening of the second rib 55 is used for the transition portion 23 to pass through, so as to avoid interference between the second rib 55 and the transition portion 23.

[0147] 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 coincide 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 far enough away from each second connecting portion 22. Thus, when the electrical connector is welded to the boss 211 of the first connecting portion 21, the adverse effect of the heat generated by the welding on the first insulating member 30 and the sealing ring 50 is greatly reduced, which is beneficial to reducing the risk of cracking or melting of the first insulating member 30 and improving the sealing reliability of the sealing ring 50.

[0148] It should be noted that the assembly method of the top cover assembly 100 can be the pre-injection molding method and the integral injection molding method. Please refer to Figure 9 As shown, the pre-injection molding method means that: First, the pole column 20 is formed by stamping process; Then, the first insulating member 30 is injection molded on the pole column 20 so that the pole column 20 and the first insulating member 30 form an integral body; Then, the sealing ring 50 is sleeved on the connecting sub-portion 223 of the pole column 20, and the connecting sub-portion 223 of the pole column 20 is inserted into the first through hole 11 on the cover plate 10; Then, the first fixing portion 40 is flanged so that the flanging 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 column 20 and the first insulating member 30 against the cover plate 10, and at the same time compressing the sealing ring 50 so that the sealing ring 50 seals the first through hole 11.

[0149] In the pre-injection molding method, since the first fixing portion 40 is flanged to the folded state after the first insulating member 30 is injection molded, the second insulating portion 34 of the injection molded first insulating member 30 does not cover the first fixing portion 40.

[0150] Please refer to Figure 3As shown, the one-piece injection molding method means: First, the pole column 20 is formed by stamping process; then, the sealing ring 50 is sleeved on the connecting part 223 of the pole column 20, and the connecting part 223 is inserted into the first through hole 11 on the cover; then, the pole column 20, the sealing ring 50 and the cover plate 10 are assembled as a whole into an injection mold for injection molding, and the first insulating part 30 is injection molded (the flanging part 43 of the first fixing part 40 has been flanged during the injection molding of the first insulating part 30). During the injection molding of the first insulating part 30, pressure is applied to the pole column 20, so that the pole column 20 compresses the sealing ring 50, that is, the sealing ring 50 maintains a certain compression amount; after the injection molding is completed, the cover plate 10, the sealing ring 50, the pole column 20 and the first insulating part 30 are removed from the injection mold as a whole. At this time, the pressure applied to the pole column 20 disappears, but due to the pressing action of the flanging part 43 of the first fixing part 40 on the first insulating part 30, the pole column 20 and the first insulating part 30 can be kept pressed on the cover plate 10, and the sealing ring 50 can also be kept in a compressed state.

[0151] In the one-piece injection molding method, since the flanging part 43 of the first fixing part 40 has been flanged to the folded state before the injection molding of the first insulating part 30, the second insulating part 34 of the injection molded first insulating part 30 still covers the flanging part 43 of the first fixing part 40 and at least part of the vertical side part 41.

[0152] In some embodiments, the two second connecting parts 22 are respectively located on both sides of the first connecting part 21 in the first preset direction. That is to say, one of the second connecting parts 22, the first connecting part 21 and the other second connecting part 22 are arranged at intervals along the first preset direction (i.e., the width direction of the cover plate 10).

[0153] Of course, the positions of the two second connecting parts 22 are not limited to being located on both sides of the first connecting part 21, as long as it is ensured that the two second connecting parts 22 are arranged along the first preset direction. In other embodiments, the two second connecting parts 22 are located on the same side of the first connecting part 21 in the second preset direction, and the second preset direction is consistent with the length direction of the cover plate 10. In this way, by arranging the two second connecting parts 22 on the same side of the first connecting part 21, the size of the pole column 20 in the width direction of the cover plate 10 is further reduced to adapt to the cover plate 10 with a narrower width.

[0154] The above-described embodiments of the installation of the terminal post 20 on the cover plate 10 have been described. However, the terminal post 20 is not limited to being installed on the cover plate 10. In other embodiments, the terminal post 20 can also be installed on the housing 200. Specifically, the battery cell 1 includes a housing 200, a battery core assembly 300, a terminal post 20, and a first insulating member 30. The housing 200 has a receiving cavity and a first wall that serves as one 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 penetrates through the inner side surface and the outer side surface. The battery core assembly 300 is received in the receiving cavity of the housing 200, and at least two electrode tabs 302 are provided on the side facing the first wall. The terminal post 20 includes a first connecting portion 21 and at least two second connecting portions 22. The first connecting portion 21 is disposed on the outer side surface of the first wall. 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 connecting portion 22 at least partially penetrates through the first through hole 11 and is respectively connected to the corresponding electrode tab 302. The first insulating member 30 includes a first insulating portion 31 provided between the first connecting portion 21 and the first wall to form insulation.

[0155] It should be noted that, compared with the embodiment in which the terminal post 20 is installed on the first wall of the housing 200, the difference from the embodiment in which the terminal post 20 is installed on the cover plate 10 is only the installation position of the terminal post 20, and the other structures are the same, so it will not be elaborated here.

[0156] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0157] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A top cover assembly, characterized in that: include: A cover plate (10) comprising a first surface (a1), a second surface (a2) and a first through hole (11), wherein the first surface (a1) and the second surface (a2) are opposite to each other, 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 connection portion (21) and at least two second connection portions (22), wherein the first connection portion (21) is located on a side of the cover plate (10) having the first surface (a1), and each of the second connection portions (22) is connected to the first connection portion (21) and arranged along a first preset direction; each of the second connection portions (22) is at least partially disposed in the first through hole (11) and is used to be connected to a pole lug respectively; and A first insulating member (30), comprising a first insulating portion (31) arranged between the first connecting portion (21) and the cover plate (10); 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).

2. The top cover assembly according to claim 1, characterized in that: Each second connecting portion (22) comprises 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) penetrating the first through hole (11).

3. The top cover assembly according to claim 2, characterized in that: One end of the connecting sub-portion (223) away from the second area (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).

4. The top cover assembly according to claim 3, characterized in that: The top cover assembly further comprises a second insulating member (60), wherein the second insulating member (60) is arranged on a second surface (a2) of the cover plate (10), the welding end (a3) ​​passes through the second insulating member (60), and the welding surface (a4) protrudes from a side surface of the second insulating member (60) away from the cover plate (10), or the welding surface (a4) is flush with a side surface of the second insulating member (60) away from the cover plate (10).

5. The top cover assembly according to claim 3, characterized in that: 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.

6. The top cover assembly according to claim 3, characterized in that: 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.

7. The top cover assembly according to claim 2, characterized in that: The first insulating member (30) further comprises a second insulating portion (34), and at least a portion of the second insulating portion (34) covers the second region (222).

8. The top cover assembly according to claim 7, characterized in that: The first insulating portion and the second insulating portion are integrally formed.

9. The top cover assembly according to claim 7, characterized in that: 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).

10. The top cover assembly according to claim 9, characterized in that: The second insulating portion (34) is recessed toward the first groove (225) to form a pit (341).

11. The top cover assembly according to claim 7, characterized in that: The top cover assembly (100) further comprises 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).

12. The top cover assembly according to claim 11, characterized in that: The first fixing portion (40) extends along a peripheral edge of the second connecting portion (22).

13. The top cover assembly according to claim 12, characterized in that: 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 a 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).

14. The top cover assembly according to claim 13, characterized in that: The center angle of the first arc segment (45) is greater than 90°; and / or The center angle of the second arc segment (49) is greater than 90°.

15. The top cover assembly according to claim 13, characterized in 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 greater than or equal to 1.4 mm; and / or The distance between an 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.

16. The top cover assembly according to claim 11, characterized in that The first fixing portion (40) comprises a vertical edge sub-portion (41) and a flanged edge sub-portion (43); the vertical edge sub-portion (41) is connected to the first surface (a1) of the cover plate (10); the flanged edge sub-portion (43) is connected to the vertical edge sub-portion (41) and is bent relative to the vertical edge sub-portion (41) to a side of the second insulating portion (34) facing away from the cover plate (10).

17. The top cover assembly according to claim 16, characterized in that An insulating gap (430) is provided between one end of the flange sub-portion (43) facing away from the vertical edge sub-portion (41) and the second region (222), and a portion of the second insulating portion (34) is filled in the insulating gap (430).

18. The top cover assembly according to claim 16, characterized in that: 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 flange sub-portion (43).

19. The top cover assembly according to claim 16, characterized in that 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 connection 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.

20. The top cover assembly according to claim 1, characterized in that The pole (20) further comprises 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).

21. The top cover assembly according to claim 20, characterized in that Each of the transition portions (23) is provided with a second through hole (231); each of the second connecting portions (22) comprises 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) penetrating the first through hole (11); The first insulating member (30) further comprises 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 second through hole (231), and the third insulating portion (32) is connected to the first insulating portion (31) and the second insulating portion (34).

22. The top cover assembly according to claim 21, characterized in that The first insulating portion (31), the second insulating portion (34) and the third insulating portion (32) are integrally formed.

23. The top cover assembly according to claim 2, characterized in that The top cover assembly (100) further comprises a sealing ring (50), wherein the sealing ring (50) comprises a first sealing portion (51) and a second sealing portion (53), wherein the first sealing portion (51) and the second sealing portion (53) are both sleeved on the connecting sub-portion (223), wherein the first sealing portion (51) is located between the connecting sub-portion (223) and the inner wall of the first through hole (11), and the second sealing portion (53) is located between the second area (222) and the first surface (a1) of the cover plate (10).

24. The top cover assembly according to claim 23, characterized in that 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).

25. The top cover assembly according to claim 23, characterized in that 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).

26. The top cover assembly according to claim 25, characterized in that The second convex strip (55) is C-shaped, and the opening of the second convex strip (55) faces the first connecting portion (21).

27. The top cover assembly according to claim 1, 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).

28. The top cover assembly according to claim 27, characterized in that The second groove (210) is at least partially gradually narrowed or stepped narrowed in a direction from the groove bottom to the groove opening.

29. The top cover assembly according to claim 27, characterized in that The depth dimension of the second groove (210) is h1, the thickness dimension of the first connection portion (21) is H1, and h1 and H1 satisfy: h1=(5%-50%)H1.

30. The top cover assembly according to claim 1, 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).

31. The top cover assembly according to claim 30, characterized in that The third groove (12) is gradually narrowed or stepped in a direction from the groove bottom to the groove mouth.

32. The top cover assembly according to claim 30, characterized in that 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%-50%)H2.

33. The top cover assembly according to claim 1, characterized in that The first connection 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 arranged to protrude relative to the annular surface (213) in a direction facing away from the cover plate (10); The first insulating member (30) further comprises a fourth insulating portion (35), wherein the fourth insulating portion (35) is arranged around the first connecting portion (21) and covers a peripheral edge of the first connecting portion (21); The surface of the fourth insulating portion (35) is flush with the annular surface.

34. The top cover assembly according to claim 1, characterized in that The number of the second connection parts (22) is two, and the two second connection parts (22) are respectively located on two sides of the first connection part (21) in the first preset direction; or Each of the second connection portions (22) is located on the same side of the first connection portion (21) in a second preset direction, and the first preset direction is perpendicular to the second preset direction.

35. 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 34; The shell has a receiving cavity and an opening connected to 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 pole lugs on a side facing the cover plate (10), and each second connection portion (22) is connected to the corresponding pole lug by passing through the first through hole (11) into the receiving cavity.

36. A battery cell, characterized in that: include: A housing having a receiving cavity and a first wall as a side wall of the receiving cavity, wherein the first wall has an inner side surface, an outer side surface and a first through hole, wherein the inner side surface faces the receiving cavity, the outer side surface faces away from the receiving cavity, and the first through hole passes 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 connection portion and at least two second connection portions, wherein the first connection portion is arranged on the outer side of the first wall, each of the second connection portions is connected to the first connection portion and arranged along the width direction of the first wall; each of the second connection portions is at least partially passed through the first through hole and is respectively connected to the corresponding pole lug; and a first insulating member, comprising a first insulating portion disposed between the first connecting portion and the first wall; On a virtual plane perpendicular to the thickness direction of the first wall, 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.

37. A battery, characterized in that: Comprising a battery cell as claimed in claim 35 or 36.

38. An electrical device, characterized in that: Includes the battery cell as claimed in claim 35 or 36, or includes the battery as claimed in claim 37.

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