A top cover assembly, a battery monomer, a battery and an electric device

Abstract

This 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; a terminal post including at least one 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 predetermined direction; each second connecting portion extending from the first through hole to the second surface of the cover plate, and each second connecting portion having a terminal tab connecting surface for connecting with a tab; the orthographic projection of each second connecting portion on the plane of the first surface being located within the range of the first through hole, and the first connecting portion at least partially overlapping the cover plate in the thickness direction of the cover plate; and a first insulating member including a first insulating portion sleeved between the second connecting portion and the inner wall of the first through hole, the two ends of the first insulating portion extending from the first through hole to the first surface and the second surface of the cover plate, respectively.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a top cover assembly, a battery cell, a battery, and an electrical device. Background Technology

[0002] Lithium-ion batteries have advantages such as high energy density, long cycle life, high rate performance, good safety and environmental friendliness, making them an important energy product for modern electronic products and electric vehicles.

[0003] A battery cell is a crucial component of a battery, typically comprising the cell itself, a top cover, and terminals. For larger cells, bridge-type terminals are mounted on the top cover, connecting the cell's tabs from the inside to the outside of the top cover, offering good usability. However, to achieve a seal, a flange needs to be formed on the terminal to press the sealing ring firmly against the top cover. This flange increases the width of the terminal, making it unsuitable for thinner battery cells where the top cover's width may not meet the terminal installation requirements. Utility Model Content

[0004] Therefore, it is necessary to provide a top cover assembly, battery cell, battery, and power device that can reduce the width of the terminal post and ensure that the narrower top cover can meet the installation requirements of the terminal post.

[0005] On one hand, this application provides a top cover assembly, including:

[0006] A cover plate has a first surface, a second surface, and a first through hole, wherein the first surface and the second surface are opposite to each other in the thickness direction of the cover plate, and the first through hole penetrates the first surface and the second surface;

[0007] An electrode post includes 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 arranged along a predetermined direction, the predetermined direction being the width direction of the cover plate. Each second connecting portion extends from the first through hole to the second surface of the cover plate, and each second connecting portion has a tab connecting surface for connecting to a tab at one end opposite to the first connecting portion along the thickness direction of the cover plate. The orthographic projection of each second connecting portion on the plane containing the first surface is within the range of the first through hole, and the first connecting portion at least partially overlaps the cover plate in the thickness direction of the cover plate.

[0008] The first insulating element includes a first insulating portion sleeved between the second connecting portion and the inner wall of the first through hole, wherein the two ends of the first insulating portion extend from the first through hole to the first surface and the second surface of the cover plate, respectively.

[0009] In some embodiments, the second connecting portion includes a bottom wall and a side wall, one end of the side wall is connected to the bottom wall, and the other end extends away from the bottom wall; the side wall includes a first sub-side wall and a second sub-side wall arranged opposite to each other in the preset direction, the first sub-side wall is located between the second sub-side wall and the first connecting portion, and the tab connecting surface is the side surface of the bottom wall away from the side wall.

[0010] In some embodiments, the orthographic projection of the first sub-sidewall onto the first surface at least partially overlaps with the orthographic projection of the first connection portion onto the first surface.

[0011] In some embodiments, the sidewall is annular around an axis parallel to the thickness direction of the cover plate to form a groove together with the bottom wall, the opening of the groove being formed at the end of the sidewall away from the bottom wall; the end of the second sub-sidewall away from the bottom wall is folded outwards towards the groove to form a flange.

[0012] In some embodiments, the second connection portion includes a first metal layer and a second metal layer, the second metal layer covering the side of the first metal layer opposite to the first connection portion along the thickness direction of the cover plate; the surface of the second metal layer opposite to the first metal layer includes the tab connection surface; wherein, at the flange, the interface between the first metal layer and the second metal layer is perpendicular to the thickness direction of the cover plate.

[0013] In some embodiments, the sidewall is annular around an axis parallel to the thickness direction of the cover plate to form a groove together with the bottom wall, the opening of the groove being formed at the end of the sidewall away from the bottom wall; the end of the second sub-sidewall away from the bottom wall has no flange.

[0014] In some embodiments, the second connection portion includes a first metal layer and a second metal layer, the second metal layer covering the side of the first metal layer opposite to the first connection portion along the thickness direction of the cover plate; the surface of the second metal layer opposite to the first metal layer includes the tab connection surface; wherein, at the sidewall, the interface between the first metal layer and the second metal layer is parallel to the thickness direction of the cover plate.

[0015] In some embodiments, the inner wall surface of the sidewall is set at 90° to the inner wall surface of the bottom wall; and / or, the outer wall surface of the sidewall is set at 90° to the tab connection surface.

[0016] In some embodiments, the second connection portion includes a first metal layer and a second metal layer, the second metal layer covering the side of the first metal layer opposite to the first connection portion along the thickness direction of the cover plate; the surface of the second metal layer opposite to the first metal layer includes the tab connection surface; the thickness of the second metal layer at at least a portion of the first sub-sidewall is greater than the thickness of the second metal layer at at least a portion of the second sub-sidewall.

[0017] In some embodiments, the thickness of at least a portion of the first sub-sidewall is greater than the thickness of at least a portion of the second sub-sidewall.

[0018] In some embodiments, the side surface of the second connector facing away from the tab connection surface is a plane.

[0019] In some embodiments, the pole post further includes a transition portion connecting the first connection portion and the second connection portion, wherein the orthographic projection of the transition portion on the first surface is at least partially located within the range of the first through hole.

[0020] In some embodiments, the pole post further includes a transition portion connecting the first connecting portion and the second connecting portion, wherein the orthographic projection of the transition portion on the first surface does not overlap with the orthographic projection of the first connecting portion and / or the second connecting portion on the first surface; or

[0021] The orthographic projection of the transition portion on the first surface does not overlap with the orthographic projection of the first connecting portion on the first surface, but the orthographic projection of the transition portion on the first surface overlaps with the orthographic projection of the second connecting portion on the first surface; or

[0022] The orthographic projection of the transition portion on the first surface does not overlap with the orthographic projection of the first connecting portion on the first surface, and at least partially overlaps with the orthographic projection of the second connecting portion on the first surface; or

[0023] The orthographic projection of the transition portion on the first surface at least partially overlaps with the orthographic projections of the first connecting portion and the second connecting portion on the first surface.

[0024] In some embodiments, the first insulating member further includes a second insulating portion and a third insulating portion, the second insulating portion covering the side surface of the second connecting portion opposite to the tab connecting surface, and the third insulating portion being located between the first connecting portion and the cover plate.

[0025] In some embodiments, the first insulating portion, the second insulating portion, and the third insulating portion are integrally disposed.

[0026] In some embodiments, the first connecting portion has micropores on one side of the cover plate and the surface of the cover plate facing the first connecting portion, and the third insulating portion is formed by nano-injection molding so that the third insulating portion is embedded in the micropores on the cover plate and the first connecting portion.

[0027] In some embodiments, the peripheral surface of the second connector and the side surface opposite to the tab connection surface both have micropores. The first insulating part and the second insulating part are formed by nano-injection molding so that the first insulating part is embedded in the micropores on the peripheral surface of the second connector, and the second insulating part is embedded in the micropores on the side surface of the second connector opposite to the tab connection surface.

[0028] In some embodiments, an insulating cavity is formed between the first connecting portion and the cover plate, and the third insulating portion fills the insulating cavity; the dimension W1 of the insulating cavity in the thickness direction of the cover plate is 0.5 mm to 1.2 mm.

[0029] In some embodiments, the first insulating portion includes a first insulator portion, a second insulator portion, and a third insulator portion. The first insulator portion is sleeved between the second connecting portion and the inner wall of the first through hole. The second insulator portion is located on the first surface of the cover plate and connected to the first insulator portion. The third insulator portion is located on the second surface of the cover plate and connected to the first insulator portion. The outer diameter of both the second insulator portion and the third insulator portion is larger than the radial dimension of the first through hole.

[0030] In some embodiments, the top cover assembly further includes a second insulating member disposed on the side of the cover plate having the second surface and having a second through hole; the third insulator portion is located inside the second through hole and has a mating surface that is in contact with the inner wall of the second through hole, and both the inner wall of the second through hole and the mating surface are inclined relative to the thickness direction of the cover plate.

[0031] In some embodiments, the orthographic projection of the first connecting portion on the first surface of the cover plate does not overlap with the first through hole, and the distance W2 between the first connecting portion and the first through hole in the preset direction is 0 mm to 10 mm; or, the orthographic projection of the first connecting portion on the first surface of the cover plate partially overlaps with the first through hole, and the size W3 of the portion of the first through hole covered by the orthographic projection of the first connecting portion on the first surface in the preset direction is 0 mm to 10 mm.

[0032] In some embodiments, the dimension W4 of the first connecting part in the preset direction is 8 mm to 35 mm, and the dimension W5 of the cover plate in the preset direction is greater than or equal to 20 mm, and W5 is greater than W4; or, the dimension W4 of the first connecting part in the preset direction and the dimension W5 of the cover plate in the preset direction satisfy: 20% ≤ W4 / W5 ≤ 50%.

[0033] In some embodiments, the cover plate has a dimension of W5 in the preset direction, the distance between the first connecting portion and one side of the cover plate in the preset direction is W6, and W5 and W6 satisfy: 25% ≤ W6 / W5 ≤ 40%.

[0034] In some embodiments, a sealing ring is provided between the first insulating element and the cover plate.

[0035] On the other hand, this application provides a battery cell including a housing, a cell assembly, and a top cover assembly as described in any of the above embodiments; the housing has a receiving cavity and an opening communicating with the receiving cavity, the cover plate is disposed on the opening, the cell assembly is disposed in the receiving cavity, and has at least two tabs on the side facing the cover plate, and the tab connection surface of each second connection portion is connected to the corresponding tab.

[0036] On the other hand, this application provides a battery comprising a battery cell as described in any of the above embodiments.

[0037] On the other hand, this application provides an electrical device that includes a battery cell as described in any of the above embodiments, or includes a battery as described in any of the above embodiments.

[0038] Compared with the prior art, this application has the following beneficial effects: The above-mentioned top cover assembly, battery cell, battery, and power device, by arranging the two second connecting parts of the electrode post along the arrangement direction of the two sets of battery cells (i.e., the preset direction), allow the two second connecting parts to pass through the first through hole on the cover plate and connect to the electrode tabs of the two sets of battery cells respectively. The first insulating part is sleeved between the second connecting part and the inner wall of the first through hole, which serves to insulate the second connecting part from the cover plate, and the two ends of the first insulating part extend to the first surface and the second surface of the cover plate respectively, thereby being nested and fixed on the cover plate.

[0039] In this way, the need to set a sealing ring between the second connecting part and the cover plate is avoided, so that the second connecting part of the pole does not need to be provided with a flange for pressing the sealing ring, thereby greatly reducing the width dimension of the second connecting part (i.e., the dimension in the preset direction), and thus reducing the width dimension of the entire pole (i.e., the dimension in the preset direction). The space occupied by the pole in the width direction of the cover plate is greatly reduced, so that the pole can be installed on a cover plate with a smaller width. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of a single battery cell in one embodiment of this application;

[0041] Figure 2 for Figure 1 A cross-sectional view of the battery cell shown;

[0042] Figure 3 for Figure 2 The image shows a magnified view of a single battery cell at point A.

[0043] Figure 4 for Figure 2 A schematic diagram of the structure of the cover plate of the top cover assembly of the battery cell shown;

[0044] Figure 5 for Figure 2 A schematic diagram of the terminal post structure of the top cover assembly of the battery cell is shown.

[0045] Figure 6 for Figure 5 A cross-sectional view of the pole shown;

[0046] Figure 7 for Figure 2 A schematic diagram of the structure of the first insulating component of the top cover assembly of the battery cell shown;

[0047] Figure 8 for Figure 7 A cross-sectional view of the first insulating element shown;

[0048] Figure 9 for Figure 2 A schematic diagram of the structure of the second insulating component of the top cover assembly of the battery cell shown;

[0049] Figure 10 This is a schematic diagram of the pole structure in another embodiment of this application;

[0050] Figure 11 for Figure 10 A cross-sectional view of the pole shown;

[0051] Figure 12 This is a cross-sectional view of the top cover assembly of a battery cell in another embodiment of this application;

[0052] Figure 13 for Figure 12 A cross-sectional view of the terminal post of the top cover assembly of the battery cell shown;

[0053] Figure 14 This is a cross-sectional view of the top cover assembly of a battery cell in another embodiment of this application;

[0054] Figure 15 for Figure 14 A cross-sectional view of the terminal post of the top cover assembly of the battery cell shown. Detailed Implementation

[0055] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0056] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0058] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0059] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0060] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0061] One embodiment of this application provides an electrical device, a battery, a battery cell, and a top cover assembly 100. The electrical device includes a battery or a battery cell and is capable of receiving electrical energy from the battery or battery cell. The electrical device can be a vehicle, mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, power tool, energy storage device, amusement equipment, elevator, and lifting equipment, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, or electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.; energy storage devices can be energy storage walls, base station energy storage, container energy storage, etc.; amusement equipment can be a carousel, a drop tower, etc.

[0062] The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended vehicles, etc. For new energy vehicles, the aforementioned battery can serve as a driving power source, thereby replacing fossil fuels to provide propulsion. This application does not impose any special restrictions on the aforementioned electrical devices.

[0063] The aforementioned battery can be a battery pack or a battery module. When the battery is a battery pack, the battery pack specifically includes a battery management system (BMS) and multiple battery cells. Multiple battery cells can be electrically connected in series, parallel, or a combination of series and parallel connections, and communicate with the battery management system, which controls and monitors the operating status of each battery cell. Alternatively, multiple battery cells can first be combined with a module management system to form a battery module, and then these battery modules can be electrically connected in series, parallel, or a combination of series and parallel connections to form a battery pack together with the battery management system.

[0064] Multiple battery cells can be mounted on supporting structures such as housings, frames, and brackets. Electrical connections between battery cells and between battery cells and the battery management system can be established via electrical connectors, which can be busbars. Alternatively, battery cells can be electrically connected via their respective terminals. For example, between two adjacent battery cells, one battery cell has a slot on its terminal, and the other battery cell has a corresponding insert on its terminal. The insert is inserted into the slot to achieve electrical connection. Therefore, for one battery cell, the aforementioned electrical connector can be the terminal of another battery cell. Similarly, battery cells and the battery management system can also be electrically connected via mutual insertion, which will not be elaborated further here. The aforementioned battery cells can be lithium-ion, sodium-ion, or magnesium-ion batteries, and their external contours can be cylindrical, flat, cuboid, or other shapes, but are not limited to these. Specifically, in this embodiment, the aforementioned battery cell is a lithium-ion square battery.

[0065] See Figure 1 and Figure 2The aforementioned battery cell includes a top cover assembly 100, a housing 200, and a cell assembly 300. The housing 200 has an opening at at least one end and a receiving cavity 201 communicating with the opening. The cell assembly 300 is housed within the receiving cavity 201 of the housing 200, and the top cover assembly 100 covers the opening of the housing 200, thereby enclosing the cell assembly 300 within the receiving cavity 201 of the housing 200. The cell assembly 300 may be a single-core battery with two tab groups 301 of the same polarity arranged along the thickness direction of the core. Each tab group 301 is connected to the second connecting portion 22 of the terminal post 20. The cell assembly 300 may also include at least two sets of cells 302 arranged side-by-side along the thickness direction of the housing 200, with each set of cells 302 extending tabs 301 toward the end face of the top cover assembly 100.

[0066] It should be noted that each group of battery cells 302 can be a single battery cell 302 or multiple battery cells 302, and this is not limited here. When each group of battery cells 302 includes a single battery cell 302, the battery cell 302 extends a positive electrode tab and a negative electrode tab towards the end face of the top cover assembly 100. When each group of battery cells 302 includes multiple battery cells 302, each battery cell 302 extends a positive electrode tab and a negative electrode tab towards the end face of the top cover assembly 100. The positive electrode tabs on the battery cells 302 in the same group are brought together to form a single positive electrode tab, and the negative electrode tabs on the battery cells 302 in the same group are brought together to form a single negative electrode tab.

[0067] In one embodiment, the battery cell assembly 300 includes two sets of battery cells 302, each set of battery cells 302 including one battery cell 302. That is, the battery cell assembly 300 includes a total of two battery cells 302. The two battery cells 302 are arranged side by side along the thickness direction of the housing 200. One of the battery cells 302 has a positive electrode and a negative electrode on the end face facing the top cover assembly 100. The other battery cell 302 also has a positive electrode and a negative electrode on the end face facing the top cover assembly 100.

[0068] In related technologies, the positive terminal on the top cover assembly 100 extends directly into the receiving cavity 201 and connects directly to the positive terminals of each group of battery cells 302. However, since each group of battery cells 302 is arranged along the thickness direction of the housing 200, the positive terminals of each group of battery cells 302 are also arranged along the thickness direction of the housing 200. Because the span of each positive terminal in the thickness direction of the housing 200 is relatively large, in order to achieve direct connection between the positive terminal and each positive terminal, the positive terminal needs to be positioned in the middle of the thickness direction of the housing 200 and extend to both sides, so that the positive terminal is as close as possible to the positive terminals on both sides in the thickness direction of the housing 200, ensuring that each positive terminal can be directly connected to the positive terminal. To achieve a seal, the positive terminal also needs to have a flange added, which is used to press the sealing ring. The flange further increases the width of the positive terminal. However, as the radial dimension of the positive terminal increases, the material cost of the positive terminal increases, and the size of the mounting hole used to install the positive terminal becomes larger, resulting in insufficient strength of the cover plate 10 of the top cover assembly 100. That is, the width of the cover plate 10 of the top cover assembly 100 cannot meet the installation space requirements of the positive terminal. It should be noted that the negative terminal also suffers from the same defects, which will not be elaborated here.

[0069] To overcome the aforementioned shortcomings, the inventors of this application have creatively proposed a technical solution that enables direct connection between the tab 301 and the post 20 while minimizing the width of the post 20. The specific structure of the top cover assembly 100 is described in detail below with reference to the accompanying drawings. Please refer to... Figures 3 to 6 As shown in the embodiment of this application, the top cover assembly 100 includes a cover plate 10, a terminal post 20, and a first insulating member 30. The cover plate 10 has a first surface a1, a second surface a2, and a first through hole 11. The first surface a1 and the second surface a2 are opposite to each other in the thickness direction of the cover plate 10, and the first through hole 11 penetrates the first surface a1 and the second surface a2 of the cover plate 10. The cover plate 10 is placed over 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 cell assembly 300 in the receiving cavity 201 of the housing 200, and the second surface a2 of the cover plate 10 faces the cell assembly 300 in the receiving cavity 201 of the housing 200. The thickness direction of the housing 200 is consistent with the preset direction X, that is, the two sets of cells 302 of the cell assembly 300 in the housing 200 are arranged side by side along the preset direction X, so the terminals 301 of the two sets of cells 302 are also arranged at intervals along the preset direction X.

[0070] 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 disposed on the cover plate 10. The positive terminal post is used to connect to the positive tab of each group of battery cells 302, thereby leading the positive tab of each group of battery cells 302 out of the housing 200; the negative terminal post is used to connect to the negative tab of each group of battery cells 302, thereby leading the negative tab of each group of battery cells 302 out of the housing 200. The positive terminal post serves as the positive terminal of the battery cell, and the negative terminal post serves as the negative terminal of the battery cell. Electrical connectors are used to connect the positive and negative terminals of each battery cell to achieve series, parallel, or mixed series and parallel connections of the battery cells.

[0071] It should be noted that, since the positive and negative terminals have similar structures, this article will use one of the terminals as an example for ease of understanding. That is to say, the "terminal" in this article can be either a positive terminal or a negative terminal (unless explicitly stated otherwise), and the "tab" in this article can be either a positive tab or a negative tab (unless explicitly stated otherwise), as long as all tabs 301 connected to the positive terminal are positive tabs and all tabs 301 connected to the negative terminal are negative tabs.

[0072] The electrode post 20 includes a first connecting portion 21 and two second connecting portions 22. The two second connecting portions 22 are arranged at intervals along a predetermined direction X (i.e., the width direction of the cover plate 10). A first connecting portion 21 is provided between the two second connecting portions 22, and the first connecting portion 21 is connected to the two adjacent second connecting portions 22. The first connecting portion 21 is located on the side of the cover plate 10 with a first surface a1 and is used to connect with an electrical connector. Each second connecting portion 22 extends from the first surface a1 of the cover plate 10 to the second surface a2 of the cover plate 10 through a first through hole 11, and each second connecting portion 22 has a tab connecting surface a4 for connecting with a corresponding tab 301 at one end facing the second surface a2 of the cover plate 10 (i.e., the end facing away from the first connecting portion 21 in the thickness direction of the cover plate 10). The two second connecting portions 22 are connected to the tabs 301 of the two sets of battery cells 302 one-to-one through the tab connecting surface a4. Each second connecting portion 22 has its orthographic projection on the plane where the first surface a1 is located within the range of the first through hole 11, and the first connecting portion 21 at least partially overlaps with the cover plate 10 in the thickness direction of the cover plate 10.

[0073] The first insulating member 30 includes a first insulating portion 31 sleeved between the second connecting portion 22 and the inner wall of the first through hole 11. The two ends of the first insulating portion 31 extend from the inside of the first through hole 11 to the first surface a1 and the second surface a2 of the cover plate 10, respectively, thus creating a structure in which the first insulating portion 31 is nested and fixed on the cover plate 10. This allows the first insulating portion 31 to both insulate the second connecting portion 22 from the cover plate 10 and to fix the second connecting portion 22 to the cover plate 10. In some embodiments, a sealing ring may be provided between the first insulating portion 31 and the cover plate 10. In other embodiments, the sealing ring may be omitted, and the first insulating portion directly seals the gap between the second connecting portion 22 and the inner wall of the first through hole 11.

[0074] The aforementioned top cover assembly 100 arranges the two second connecting portions 22 of the electrode post 20 along the arrangement direction (i.e., the preset direction X) of the two sets of battery cells 302, so that the two second connecting portions 22 pass through the first through hole 11 on the cover plate 10 and are respectively connected to the electrode tabs 301 of the two sets of battery cells 302. The first insulating portion 31 is sleeved between the second connecting portion 22 and the inner wall of the first through hole 11, which serves to insulate the second connecting portion 22 from the cover plate 10, and the two ends of the first insulating portion 31 extend to the first surface a1 and the second surface a2 of the cover plate 10, respectively, thereby being nested and fixed on the cover plate 10. In this way, the need to set a sealing ring between the second connecting part 22 and the cover plate 10 is avoided, so that the second connecting part 22 of the pole post 20 does not need to be provided with a flange for pressing the sealing ring, thereby greatly reducing the width dimension of the second connecting part 22 (i.e., the dimension in the preset direction X), and further reducing the width dimension of the entire pole post 20 (i.e., the dimension in the preset direction X). The space occupied by the cover plate 10 in the width direction of the pole post 20 is greatly reduced, so that the pole post 20 can be installed on the cover plate 10 with a smaller width.

[0075] It should be noted that in the prior art, the second connecting part 22 is provided with a flange, which is used to press the sealing ring onto the cover plate 10, thereby achieving a seal on the first through hole 11. Since the flange is located on the peripheral edge of the second connecting part 22, it hardly plays a role in flow passage. Therefore, in the embodiment of this application, the second connecting part 22 is not provided with a flange for pressing the sealing ring, and the flow passage capacity of the pole 20 is hardly reduced.

[0076] It should also be noted that the number of first connecting parts 21 is not limited to one; it can be two or more. Similarly, the number of second connecting parts 22 is not limited to two; it can be three or more. The number of first connecting parts 21 and second connecting parts 22 is related to the number of groups of battery cells 302. Specifically, if there are N groups of battery cells 302, the number of second connecting parts 22 is also set to N. These N second connecting parts 22 are arranged at intervals along a preset direction X. A first connecting part 21 is provided between every two adjacent second connecting parts 22, and each pair of adjacent second connecting parts 22 is connected to the first connecting part 21 between them; that is, there are N-1 first connecting parts 21. The N second connecting parts 22 respectively pass through the first through holes 11 on the cover plate 10 and are connected one-to-one with the tabs 301 of each group of battery cells 302. It should be noted that the number of groups of battery cells 302 is not the same as the quantity of battery cells 302. For example, a battery cell assembly 300 may include four battery cells 302. Two battery cells 302 form one group, with their tabs 301 joined together to form a single tab 301, which is connected to a second connection part 22. The other two battery cells 302 form another group, with their tabs 301 joined together to form a single tab 301, which is connected to another second connection part 22. In this case, there are two groups of battery cells 302, but the quantity of battery cells 302 is four. The two are not the same. For ease of understanding, this article will use the example of a battery cell assembly 300 including two groups of battery cells 302, each group including one battery cell 302, and the terminal 20 including a first connection part 21 and two second connection parts 22.

[0077] In a specific embodiment, a first through hole 11 is formed on the cover plate 10 at the position of each of the two second connecting portions 22 corresponding to the pole post 20, so that the two second connecting portions 22 of the pole post 20 respectively pass through the corresponding first through hole 11, and are then connected to the two pole ears 301 on the inner side of the cover plate 10. The first connecting portion 21 is opposite to the portion of the cover plate 10 located between the two first through holes 11, so that the orthographic projection of the first connecting portion 21 on the first surface a1 of the cover plate 10 at least partially overlaps with the cover plate 10.

[0078] by Figure 4 As shown in the example, the cover plate 10 has four first through holes 11. Two of the first through holes 11 are located at one end of the length direction of the cover plate 10 and are spaced apart along the width direction of the cover plate 10. The other two first through holes 11 are located at the other end of the length direction of the cover plate 10 and are also spaced apart along the width direction of the cover plate 10.

[0079] Please see Figure 3 , Figure 7 and Figure 8In the embodiments of this application, the first insulating member 30 further includes a second insulating portion 32 and a third insulating portion 33. The second insulating portion 32 covers the side surface of the second connecting portion 22 facing away from the tab connection surface a4, and the third insulating portion 33 is located between the first connecting portion 21 and the cover plate 10. Thus, the second insulating portion 32 provides insulation protection for the side surface of the second connecting portion 22 facing away from the tab connection surface a4, which helps to enhance the overall strength of the pole post 20 and reduce the risk of deformation of the pole post 20. The third insulating portion 33 provides insulation between the first connecting portion 21 and the cover plate 10, preventing electrical conduction between the first connecting portion 21 and the cover plate 10.

[0080] Furthermore, the first insulating portion 31, the second insulating portion 32, and the third insulating portion 3332 of the first insulating member 30 are integrally formed, for example, by injection molding. During injection molding of the first insulating member 30, a portion of the molten injection material flows into the first through hole 11, and after solidification, forms the first insulating portion 31 fitted between the second connecting portion 22 and the inner wall of the first through hole 11; a portion of the molten injection material flows to the surface of each of the second connecting portions 22, and after solidification, forms the second insulating portion 32 covering the side of the second connecting portion 22 facing away from the tab connecting surface a4; a portion of the molten injection material flows into the space between the first connecting portion 21 and the cover plate 10, and after solidification, forms the third insulating portion 33 between the first connecting portion 21 and the cover plate 10. Of course, in other embodiments, the first insulating member 30 can also be prepared separately and then assembled into a whole. Furthermore, the first insulating portion 31, the second insulating portion 32, and the third insulating portion 3332 of the first insulating member 30 are integrally formed using a nano-injection molding process.

[0081] Specifically, the surface of the first connecting part 21 facing the cover plate 10 and the surface of the cover plate 10 facing the first connecting part 21 both have several nanometer-sized micropores. When the first insulating part 30 is injection molded, the molten injection material can enter into each micropore on the first connecting part 21 and the cover plate 10, so that the third insulating part 33 formed after solidification is embedded in the micropores on the cover plate 10 and the first connecting part 21, thereby greatly enhancing the bonding force between the third insulating part 33 and the first connecting part 21 and the cover plate 10.

[0082] Specifically, the peripheral surface of the second connecting part 22 and the side surface opposite to the tab connecting surface a4 both have several nanometer-sized micropores. When the first insulating part 30 is injection molded, the molten injection material can enter into each micropore on the second connecting part 22, so that the first insulating part 31 and the second insulating part 32 formed after solidification can be embedded in the micropores of the second connecting part 22, thereby greatly enhancing the bonding force between the first insulating part 31 and the second insulating part 32 and the second connecting part 22, and improving the sealing performance between the first insulating part 31 and the second connecting part 22, further improving the sealing effect, so that the cover plate 10 and the first insulating part 31 can be directly sealed without the need for a sealing ring.

[0083] Specifically, the surfaces of the first insulating part 31 that contact the cover plate 10 (e.g., the inner wall of the first through hole 11, the area of ​​the first surface a1 near the first through hole 11, and / or the area of ​​the second surface a2 near the first through hole 11) also have several nanoscale micropores. During injection molding of the first insulating part 30, the molten injection material can enter into each micropore on the cover plate 10, greatly increasing the bonding force between the first insulating part 31 and the cover plate 10, and improving the sealing performance between them, further enhancing the sealing effect. It should be noted that the micropores on the cover plate 10 and the pole post 20 can be formed by etching their surfaces with an etching solution.

[0084] It should be noted that in this embodiment, the first insulating component 30 is formed by nano-injection molding. On the one hand, this achieves a fixed connection between the first insulating component 30, the pole post 20, and the cover plate 10, avoiding the need to use the pressing edge on the cover plate 10 to press and fix the first insulating component 30 and the pole post 20 onto the cover plate 10. This greatly simplifies the structure and assembly process of the top cover assembly 100 and reduces the assembly difficulty and cost. On the other hand, nano-injection molding achieves a tight bond between the first insulating component 30, the pole post 20, and the cover plate 10, greatly improving the sealing effect of the first insulating component 30.

[0085] Furthermore, the first insulating portion 31 includes a first insulator portion 311, a second insulator portion 313, and a third insulator portion 315. The first insulator portion 311 is sleeved between the second connecting portion 22 and the inner wall of the first through hole 11. The second insulator portion 313 is located on the first surface a1 of the cover plate 10 and is connected to the first insulator portion 311. The third insulator portion 315 is located on the second surface a2 of the cover plate 10 and is connected to the first insulator portion 311. The outer diameter of both the second insulator portion 313 and the third insulator portion 315 is larger than the radial dimension of the first through hole 11. In this way, the cover plate 10 is secured between the second insulator portion 313 located on the first surface a1 and the third insulator portion 315 located on the second surface a2, thereby fixing the first insulating portion 31 to the cover plate 10, preventing the first insulating portion 31 from coming out of the first through hole 11, and increasing the contact area between the first insulating portion 31 and the cover plate 10, which is beneficial to improving the sealing effect.

[0086] Please see Figure 3 and Figure 9 Furthermore, the top cover assembly 100 also includes a second insulating member 40, which is disposed on the side of the cover plate 10 having a second surface a2 and has a second through hole 41. A third insulator portion 315 is located within the second through hole 41 and has a contact surface a6 that is in contact with the inner wall 411 of the second through hole 41 (see...). Figure 8 The inner wall 411 and the contact surface a6 of the second through hole 41 are both inclined relative to the thickness direction of the cover plate 10, for example, at 45°. Thus, by setting the contact surface a6 between the second insulator 40 and the third insulator portion 315 in an inclined state, it is beneficial to increase the contact area between them and improve the sealing effect. Of course, in other embodiments, the angle of inclination of the inner wall of the second through hole 41 and the contact surface a6 relative to the thickness direction of the cover plate 10 can also be 30°, 35°, 40°, 45°, 50°, 55°, 60°, or 65°, etc., and is not limited here.

[0087] Optionally, an insulating cavity is formed between the first connecting portion 21 and the cover plate 10, and the third insulating portion 33 is filled in the insulating cavity, thereby achieving insulation between the first connecting portion 21 and the cover plate 10. The dimension W1 of the insulating cavity in the thickness direction of the cover plate 10 (i.e., the thickness dimension of the third insulating portion 33) is 0.5 mm to 1.2 mm. It should be noted that the dimension W1 of the insulating cavity in the thickness direction of the cover plate 10 can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, or 1.2 mm, etc., and is not specifically limited here.

[0088] In some embodiments, the orthographic projection of the first connecting portion 21 on the first surface a1 of the cover plate 10 does not overlap with the first through hole 11, and the distance W2 between the first connecting portion 21 and the first through hole 11 in the preset direction X is 0 mm to 10 mm. It should be noted that the distance W2 between the first connecting portion 21 and the first through hole 11 in the preset direction X can be 0 mm, 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm, 5.0 mm, 6.0 mm, 7.0 mm, 8.0 mm, 9.0 mm, or 10.0 mm, etc., and is not specifically limited here.

[0089] It should be noted that the orthographic projection of the first connecting portion 21 on the first surface a1 of the cover plate 10 does not necessarily overlap with the first through hole 11. In other embodiments, the orthographic projection of the first connecting portion 21 on the first surface a1 of the cover plate 10 may also partially overlap with the first through hole 11. The dimension W3 of the portion of the first through hole 11 covered by the orthographic projection of the first connecting portion 21 on the first surface a1 in the preset direction X is 0 mm to 10 mm. Optionally, the dimension W3 of the portion of the first through hole 11 covered by the orthographic projection of the first connecting portion 21 on the first surface a1 in the preset direction X may be 0 mm, 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm, 5.0 mm, 6.0 mm, 7.0 mm, 8.0 mm, 9.0 mm, or 10.0 mm, etc., and is not specifically limited here.

[0090] In some embodiments, the dimension W4 of the first connecting portion 21 in the preset direction X is 8mm to 35mm, and the dimension W5 of the cover plate 10 in the preset direction X is greater than or equal to 20mm, and W5 is greater than W4. Optionally, the dimension W4 of the first connecting portion 21 in the preset direction X can be 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, or 35mm, etc., and is not specifically limited here.

[0091] In some embodiments, the dimensions W4 of the first connecting portion 21 in the preset direction X and the dimensions W5 of the cover plate 10 in the preset direction X satisfy: 20% ≤ W4 / W5 ≤ 50%.

[0092] In some embodiments, the size of the cover plate 10 in the preset direction X is W5, the distance between the first connecting portion 21 and one side of the cover plate 10 in the preset direction X is W6, and W5 and W6 satisfy: 25% ≤ W6 / W5 ≤ 40%.

[0093] Please see Figure 10 and Figure 11 In the embodiments of this application, the second connecting portion 22 further has a third surface a3 opposite to the electrode connecting surface a4 in the thickness direction of the cover plate 10. The second connecting portion 22 also has a groove 221 formed on the third surface a3. Thus, by forming a groove 221 on the second connecting portion 22, on the one hand, the bending resistance of the second connecting portion 22 is strengthened, and deformation of the second connecting portion 22 is avoided; on the other hand, the material usage of the electrode post 20 is reduced, thereby lowering the cost of the electrode post 20. Optionally, the sidewall of the groove does not have to be a complete annular closed structure; it can be that only a partial sidewall is provided, which can further save materials and reduce processing difficulty.

[0094] It should be noted that the groove 221 is not essential; in other embodiments, please refer to [link / reference needed]. Figure 14 and Figure 15 The side of the second connecting part 22 facing away from the electrode connecting surface a4 may not have a groove 221 formed, meaning the surface of the second connecting part 22 facing away from the electrode connecting surface a4 is flat, which facilitates the processing of the electrode post 20. With this structural design, after the electrode post plate is integrally formed, it can be formed through a single bending or stamping process, simplifying manufacturing; and it is equivalent to retaining only the connection between the first connecting part 21 and the second connecting part 22 on the original groove sidewall, eliminating the need for the other sidewalls, thus saving material.

[0095] For ease of understanding, the following explanation will take the example of the second connecting part 22 having a groove 221 formed on the side opposite to the connecting part of the tab 301.

[0096] Please continue reading Figure 10 and Figure 11 Specifically, in this embodiment, the second connecting portion 22 includes a bottom wall 223 and a side wall 225. One end of the side wall 225 is connected to the bottom wall 223, and the other end of the side wall 225 extends away from the bottom wall 223. The side wall 225 is annular around an axis parallel to the thickness direction of the cover plate 10, so that the side wall 225 and the bottom wall 223 together form the aforementioned groove 221. The opening of the groove 221 is formed at the end of the side wall 225 away from the bottom wall 223. Further, the side wall 225 includes a first sub-side wall d1 and a second sub-side wall d2 arranged opposite to each other in a predetermined direction X. The first sub-side wall d1 is located between the second sub-side wall d2 and the first connecting portion 21. The aforementioned tab connecting surface a4 is the surface of the bottom wall 223 facing away from the side wall 225. Optionally, the sidewall 225 here may only have a first sub-sidewall d1 and a second sub-sidewall d2 (not shown). That is, the entire sidewall is no longer arranged in a ring shape, and there are no sidewalls on both sides along the width direction perpendicular to the cover plate 10. This is because the removal of the sidewall does not affect the flow function. With this arrangement, the material used is more economical, and it is also easier to use non-stamping processes such as bending processes for processing, which is also simpler.

[0097] Optionally, the orthographic projection of the first sub-sidewall d1 on the first surface a1 partially overlaps or completely overlaps with the orthographic projection of the first connecting portion 21 on the first surface a1 (not shown). With this arrangement, at least a portion of the first sidewall d1 can be located below the first connecting portion 21 while ensuring the connection area between the pole and the electrical connector. This further reduces the overall size of the pole in the width direction of the cover plate 10, and also reduces the overall lateral size of the pole.

[0098] It should be noted that welding processes, such as laser welding and resistance welding, can be used to weld the electrical connector to the first connecting part 21. Alternatively, conductive adhesive can be used to bond and fix the electrical connector to the first connecting part 21, as long as electrical connection between the electrical connector and the first connecting part 21 can be achieved; no limitation is made here.

[0099] It should also be noted that the tab 301 can be welded to the tab connecting surface a4 of the second connecting part 22 using welding processes, such as laser welding, resistance welding, ultrasonic welding, and pressure welding. Of course, conductive adhesive can also be used to bond and fix the tab 301 to the tab connecting surface a4 of the second connecting part 22, as long as electrical connection between the tab 301 and the second connecting part 22 can be achieved, and no limitation is made here.

[0100] The positive terminal 20 is generally made of aluminum in one piece and can be directly contacted and welded to the positive terminal tab of the battery cell assembly 300. Since the positive terminal and the positive terminal tab of the battery cell assembly 300 are made of the same material, the welding effect between them can be improved.

[0101] The negative electrode post includes a first metal layer b1 and a second metal layer b2 stacked along the thickness direction of the electrode post 20. The first metal layer b1 extends to the first connecting portion 21 and each of the second connecting portions 22, and the second metal layer b2 extends at least to each of the second connecting portions 22. At each of the second connecting portions 22, the second metal layer b2 and the first metal layer b1 are stacked along the thickness direction of the electrode post 20, and the surface of the first metal layer b1 facing away from the second metal layer b2 includes the aforementioned third surface a3, and the surface of the second metal layer b2 facing away from the first metal layer b1 includes the aforementioned tab connecting surface a4. In other words, the second metal layer b2 is located on the side of the first metal layer b1 facing the cell assembly 300, such that the third surface a3 is the first metal layer b1 and the tab connection surface a4 is the second metal layer b2, that is, the tab 301 is welded to the second metal layer b2 at the tab connection surface a4; the part where the first connecting part 21 is welded to the electrical connector is the first metal layer b1, that is, the electrical connector is welded to the first metal layer b1 of the first connecting part 21.

[0102] Thus, by using a composite plate to prepare the electrode post 20, it is ensured that the tab 301 is welded to the second metal layer b2 at the second connection portion 22. This second metal layer b2 can be made of the same material as the corresponding tab 301, or a material that is easily welded to the corresponding tab 301, ensuring the welding quality of the tab 301 and the tab connection surface a4 of the second connection portion 22. Similarly, by using a composite plate to prepare the electrode post 20, it is ensured that the electrical connector is welded to the first metal layer b1 at the first connection portion 21. This first metal layer b1 can be made of the same material as the electrical connector, or a material that is easily welded to the electrical connector, ensuring the welding quality of the electrical connector and the first connection portion 21. More specifically, in this embodiment, the first metal layer b1 is an aluminum layer, the second metal layer b2 is a copper layer, and the electrode post 20 is made of a copper-aluminum composite plate through a stamping process. Since the negative electrode tab of the battery cell assembly 300 is generally also made of copper, the second metal layer b2 is made of the same material as the negative electrode tab, which can improve the welding effect between the negative electrode post and the negative electrode tab.

[0103] It is understood that both the bottom wall 223 and the side wall 225 of the second connecting portion 22 include a first metal layer b1 and a second metal layer b2. At the bottom wall 223, the interface c2 between the first metal layer b1 and the second metal layer b2 is approximately perpendicular to the thickness direction of the cover plate 10. At the side wall 225, the interface c1 between the first metal layer b1 and the second metal layer b2 is approximately parallel to the thickness direction of the cover plate 10.

[0104] Please see Figure 12 and Figure 13 In some embodiments, the end of the second sub-sidewall d2 away from the bottom wall 223 is folded outwards towards the groove 221 to form a flange 227. The third surface a3 is the surface of the flange 227 facing away from the bottom wall 223, and the tab connecting surface a4 is the surface of the bottom wall 223 facing away from the sidewall 225. Thus, by forming a flange 227 on the sidewall 225, it is beneficial to increase the contact area between the second connecting part 22 and the first insulating member 30, thereby extending the sealing path and improving the sealing effect. It is understood that the flange 227 in this embodiment does not serve to compress the sealing ring, and its orthographic projection along the thickness direction of the cover plate 10 on the first surface a1 of the cover plate 10 falls entirely within the range of the first through hole 11, so its size is small and has little impact on the width of the second connecting part 22 in the preset direction X. Furthermore, at the flange 227, the interface c3 between the first metal layer b1 and the second metal layer b2 is perpendicular to the thickness direction of the cover plate 10.

[0105] It should be noted that the flange 227 is not essential. In some embodiments, the end of the second sub-sidewall d2 away from the bottom wall 223 does not have a flange, see [link to relevant documentation]. Figure 10 and Figure 11As shown. The third surface a3 is the end face of the sidewall 225 away from the bottom wall 223, and the tab connection surface a4 is the side surface of the bottom wall 223 facing away from the sidewall 225. Thus, by not providing a flange on the second sub-sidewall d2, the size of the second connecting portion 22 in the width direction of the cover plate 10 can be further reduced, further reducing the space occupied by the pole post 20 in the width direction of the cover plate 10. Furthermore, at the sidewall 225, the interface c1 between the first metal layer b1 and the second metal layer b2 is parallel to the thickness direction of the cover plate 10.

[0106] Specifically, in this embodiment, the inner wall surface of the side wall 225 and the inner wall surface of the bottom wall 223 together form the aforementioned groove 221. The inner wall surface of the side wall 225 and the inner wall surface of the bottom wall 223 are set at approximately 90°. Here, the side wall 225 can be a whole circumference, or it can be set only along the preset direction X near the edge of the cover plate 10 (not shown), i.e., the first side sub-wall d1, or it can be set on both sides of the first connecting part 21 along the preset direction X, i.e., the first side sub-wall d1 and the second side sub-wall d2. This can save materials and reduce the processing difficulty. Thus, compared with the groove 221 in the prior art which has a shape that is larger at the top and smaller at the bottom, in this embodiment, the inner wall surface of the side wall 225 and the inner wall surface of the bottom wall 223 are set at approximately 90°, that is, the radial dimension of the groove 221 remains approximately unchanged from top to bottom. This is beneficial to reduce the radial dimension of the second connecting part 22, further reduce the dimension of the pole post 20 in the width direction of the cover plate 10, but without losing the area of ​​the pole tab connecting surface a4 connected to the pole tab.

[0107] In a specific embodiment, the outer wall surface of the sidewall 225 is approximately at a 90° angle to the electrode tab connection surface a4. Thus, compared to the prior art where the second connecting portion 22 has a shape that is larger at the top and smaller at the bottom, in this embodiment, the outer wall surface of the sidewall 225 is approximately at a 90° angle to the electrode tab connection surface a4. This means that the radial dimension of the second connecting portion 22 remains approximately constant from top to bottom, which helps to reduce the radial dimension of the second connecting portion 22 and further reduce the dimension of the electrode post 20 in the width direction of the cover plate 10.

[0108] Please continue reading Figure 10 and Figure 11 Specifically, in this embodiment, the sidewall 225 includes a first sub-sidewall d1 and a second sub-sidewall d2 arranged opposite each other in the width direction of the cover plate 10, wherein the first sub-sidewall d1 is located between the second sub-sidewall d2 and the first connecting portion 21. The sidewall 225 also includes a third sub-sidewall d3 and a fourth sub-sidewall d4 arranged opposite each other in the length direction of the cover plate 10. The first sub-sidewall d1, the third sub-sidewall d3, the second sub-sidewall d2 and the fourth sub-sidewall d4 are connected end to end in a ring.

[0109] Furthermore, the thickness of the second metal layer b2 at the first sub-sidewall d1 is greater than the thickness of the second metal layer b2 at the second sub-sidewall d2. Since the first sub-sidewall d1 primarily serves a current-carrying function, setting the second metal layer b2 (i.e., the copper layer) at the first sidewall 225 to be thicker and the second metal layer b2 at the second sidewall 225 to be thinner is beneficial for increasing the current-carrying capacity at the first sidewall 225, thereby increasing the current-carrying capacity of the second connection portion 22. Optionally, the overall thickness of the second metal layer b2 at the first sub-sidewall d1 may be greater than the overall thickness of the second metal layer b2 at the second sub-sidewall d2, or the thickness of a portion of the second metal layer b2 at the first sub-sidewall d1 may be greater than the thickness of a portion of the second metal layer b2 at the second sub-sidewall d2.

[0110] Furthermore, the thickness of the first sub-sidewall d1 is greater than the thickness of the second sub-sidewall d2. Since the first sub-sidewall d1 primarily serves a flow-through function, making the first sidewall 225 thicker and the second sidewall 225 thinner increases the flow-through capacity of the first sidewall 225, thereby increasing the flow-through capacity of the second connecting portion 22. Optionally, the overall thickness of the first sub-sidewall d1 can be greater than the overall thickness of the second sub-sidewall d2, or a portion of the first sub-sidewall d1 can be thicker than a portion of the second sub-sidewall d2, as long as the flow-through capacity of the first sub-sidewall d1 is relatively enhanced.

[0111] See Figure 5 , Figure 10 and Figure 14 In embodiments of this application, the pole post 20 further includes a transition portion 23. Each second connecting portion 22 is connected to the first connecting portion 21 through the transition portion 23. Specifically, the transition portion 23 may correspond to the portion located above the third surface a3 and on both sides of the outermost contour line of the first connecting portion 21. The orthographic projection of the transition portion 23 on the first surface a1 of the cover plate 10 is at least partially located within the range of the corresponding first through hole 11.

[0112] Furthermore, the transition section 23 is configured to melt first in the event of thermal runaway of a single battery cell, meaning that the transition section 23 melts before the first connecting section 21 and the second connecting section 22. Specifically, in this embodiment, the flow area of ​​the transition section 23 is smaller than that of the first connecting section 21 and smaller than that of the second connecting section 22. The flow area refers to the minimum area through which fluid passes. Here, the flow area of ​​the transition section 23 refers to the surface area of ​​the transition section 23 perpendicular to the current flow direction, i.e., the minimum cross-sectional area of ​​the transition section 23. Similarly, the flow areas of the first connecting section 21 and the second connecting section 22 refer to the surface areas of the first connecting section 21 and the second connecting section 22 perpendicular to the current flow direction, i.e., the minimum cross-sectional areas of the first connecting section 21 and the second connecting section 22. Thus, in actual use, when a circuit malfunctions, the smaller flow area of ​​the transition section 23 causes a faster temperature rise at the transition section 23, allowing it to melt quickly and promptly cut off the circuit, greatly improving battery safety. It is understandable that the transition portion 23 can reduce its current-carrying area by slotting, opening, and / or thinning, ensuring that it can melt and cut off the circuit in time when the circuit is abnormal. The thinning structure can be a general reduction in the thickness of the transition portion 23, or a groove structure formed in a part of the transition portion 23 and partially thinning the transition portion 23.

[0113] Please see Figure 14 and Figure 15 As shown, in some embodiments, the orthographic projection of the transition portion 23 on the first surface a1 of the cover plate 10 does not overlap with the orthographic projections of the first connecting portion 21 and the second connecting portion 22 on the first surface a1 of the cover plate 10.

[0114] Please see Figure 10 and Figure 11 As shown, in some other embodiments, the orthographic projection of the transition portion 23 on the first surface a1 of the cover plate 10 does not overlap with the orthographic projection of the first connecting portion 21 on the first surface a1 of the cover plate 10, and at least partially overlaps with the orthographic projection of the second connecting portion 22 on the first surface a1 of the cover plate 10. This facilitates reducing the distance between the first connecting portion 21 and the second connecting portion 22, thereby further reducing the dimension of the pole post 20 in the width direction of the cover plate 10.

[0115] In some other embodiments, the orthographic projection of the transition portion 23 on the first surface a1 of the cover plate 10 partially overlaps with the orthographic projections of the first connecting portion 21 and the second connecting portion 22 on the first surface a1 of the cover plate 10. This helps to reduce the distance between the first connecting portion 21 and the second connecting portion 22, thereby further reducing the size of the pole post 20 in the width direction of the cover plate 10.

[0116] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0117] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A top cover assembly, characterized in that, include: The cover plate (10) has a first surface (a1), a second surface (a2) and a first through hole (11). The first surface (a1) and the second surface (a2) are opposite to each other in the thickness direction of the cover plate (10), and the first through hole (11) penetrates the first surface (a1) and the second surface (a2). The pole post (20) includes at least one first connecting portion (21) and at least two second connecting portions (22). The first connecting portion (21) is located on one side of the cover plate (10) having the first surface (a1). Each of the second connecting portions (22) is connected to the first connecting portion (21) and is arranged along a preset direction (X), the preset direction being the width direction of the cover plate (10). Each of the second connecting portions (22) extends from the first through hole (11) to the second surface (a2), and each of the second connecting portions (22) has a tab connecting surface (a4) for connecting with a tab (301) at one end away from the first connecting portion (21) along the thickness direction of the cover plate (10). The orthographic projection of each of the second connecting portions (22) on the plane where the first surface (a1) is located is within the range of the first through hole (11). The first connecting portion (21) at least partially overlaps the cover plate (10) in the thickness direction of the cover plate (10). The first insulating member (30) includes a first insulating part (31) sleeved between the second connecting part (22) and the inner wall of the first through hole (11), and the two ends of the first insulating part (31) extend from the first through hole (11) to the first surface (a1) and the second surface (a2) of the cover plate (10), respectively.

2. The top cover assembly according to claim 1, characterized in that, The second connecting part (22) includes a bottom wall (223) and a side wall (225). One end of the side wall (225) is connected to the bottom wall (223), and the other end extends away from the bottom wall (223). The side wall (225) includes a first sub-side wall (d1) and a second sub-side wall (d2) arranged opposite to each other in the preset direction (X). The first sub-side wall (d1) is located between the second sub-side wall (d2) and the first connecting part (21). The tab connecting surface (a4) is the side surface of the bottom wall (223) away from the side wall (225).

3. The top cover assembly according to claim 2, characterized in that, The orthographic projection of the first sub-sidewall (d1) on the first surface (a1) at least partially overlaps with the orthographic projection of the first connecting portion (21) on the first surface (a1).

4. The top cover assembly according to claim 2, characterized in that, The sidewall (225) is annular around an axis parallel to the thickness direction of the cover plate (10) to form a groove (221) together with the bottom wall (223). The opening of the groove (221) is formed at the end of the sidewall (225) away from the bottom wall (223). The end of the second sub-sidewall (d2) away from the bottom wall (223) is folded outward toward the groove (221) to form a flange (227).

5. The top cover assembly according to claim 4, characterized in that, The second connecting portion (22) includes a first metal layer (b1) and a second metal layer (b2), the second metal layer (b2) covering the side of the first metal layer (b1) away from the first connecting portion (21) along the thickness direction of the cover plate (10); The side surface of the second metal layer (b2) facing away from the first metal layer (b1) includes the tab connection surface (a4). Wherein, at the flange (227), the interface (c3) between the first metal layer (b1) and the second metal layer (b2) is perpendicular to the thickness direction of the cover plate (10).

6. The top cover assembly according to claim 2, characterized in that, The sidewall (225) is annular around an axis parallel to the thickness direction of the cover plate (10) to form a groove (221) together with the bottom wall (223). The opening of the groove (221) is formed at the end of the sidewall (225) away from the bottom wall (223). The second sub-sidewall (d2) has no flange at the end away from the bottom wall (223).

7. The top cover assembly according to claim 6, characterized in that, The second connecting portion (22) includes a first metal layer (b1) and a second metal layer (b2), the second metal layer (b2) covering the side of the first metal layer (b1) away from the first connecting portion (21) along the thickness direction of the cover plate (10); the surface of the second metal layer (b2) away from the first metal layer (b1) includes the tab connecting surface (a4). Wherein, at the sidewall (225), the interface between the first metal layer (b1) and the second metal layer (b2) is parallel to the thickness direction of the cover plate (10).

8. The top cover assembly according to claim 4, characterized in that, The inner wall surface of the side wall (225) is set at 90° to the inner wall surface of the bottom wall (223); and / or The outer wall surface of the sidewall (225) is set at 90° to the tab connection surface (a4).

9. The top cover assembly according to claim 6, characterized in that, The inner wall surface of the side wall (225) is set at 90° to the inner wall surface of the bottom wall (223); and / or The outer wall surface of the sidewall (225) is set at 90° to the tab connection surface (a4).

10. The top cover assembly according to claim 4, characterized in that, The second connecting portion (22) includes a first metal layer (b1) and a second metal layer (b2), the second metal layer (b2) covering the side of the first metal layer (b1) away from the first connecting portion (21) along the thickness direction of the cover plate (10); The side surface of the second metal layer (b2) facing away from the first metal layer (b1) includes the tab connection surface (a4). The thickness of the second metal layer (b2) at least partially on the first sub-sidewall (d1) is greater than the thickness of the second metal layer (b2) at at least partially on the second sub-sidewall (d2).

11. The top cover assembly according to claim 6, characterized in that, The second connecting portion (22) includes a first metal layer (b1) and a second metal layer (b2), the second metal layer (b2) covering the side of the first metal layer (b1) away from the first connecting portion (21) along the thickness direction of the cover plate (10); The side surface of the second metal layer (b2) facing away from the first metal layer (b1) includes the tab connection surface (a4). The thickness of the second metal layer (b2) at least partially on the first sub-sidewall (d1) is greater than the thickness of the second metal layer (b2) at at least partially on the second sub-sidewall (d2).

12. The top cover assembly according to claim 3, characterized in that, The thickness of at least a portion of the first sub-sidewall (d1) is greater than the thickness of at least a portion of the second sub-sidewall (d2).

13. The top cover assembly according to claim 4, characterized in that, The thickness of at least a portion of the first sub-sidewall (d1) is greater than the thickness of at least a portion of the second sub-sidewall (d2).

14. The top cover assembly according to claim 6, characterized in that, The thickness of at least a portion of the first sub-sidewall (d1) is greater than the thickness of at least a portion of the second sub-sidewall (d2).

15. The top cover assembly according to claim 1, characterized in that, The side surface of the second connecting part (22) facing away from the tab connecting surface (a4) is flat.

16. The top cover assembly according to claim 1, characterized in that, The pole post (20) further includes a transition portion (23) connecting the first connecting portion (21) and the second connecting portion (22), wherein the orthographic projection of the transition portion (23) on the first surface (a1) is at least partially within the range of the first through hole (11).

17. The top cover assembly according to claim 1, characterized in that, The pole post (20) further includes a transition portion (23) connecting the first connecting portion (21) and the second connecting portion (22), wherein the orthographic projection of the transition portion (23) on the first surface (a1) does not overlap with the orthographic projection of the first connecting portion (21) and / or the second connecting portion (22) on the first surface (a1); or The orthographic projection of the transition portion (23) on the first surface (a1) does not overlap with the orthographic projection of the first connecting portion (21) on the first surface (a1), and at least partially overlaps with the orthographic projection of the second connecting portion (22) on the first surface (a1); or The orthographic projection of the transition portion (23) on the first surface (a1) at least partially overlaps with the orthographic projections of the first connecting portion (21) and the second connecting portion (22) on the first surface (a1).

18. The top cover assembly according to any one of claims 1 to 17, characterized in that, The first insulating member (30) further includes a second insulating part (32) and a third insulating part (33). The second insulating part (32) covers the side surface of the second connecting part (22) away from the tab connecting surface (a4), and the third insulating part (33) is located between the first connecting part (21) and the cover plate (10).

19. The top cover assembly according to claim 18, characterized in that, The first insulating part (31), the second insulating part (32) and the third insulating part (33) are integrally disposed.

20. The top cover assembly according to claim 18, characterized in that, The first connecting part (21) has micropores on one side of the cover plate (10) and the surface of the cover plate (10) facing the first connecting part (21). The third insulating part (33) is formed by nano-injection molding so that the third insulating part (33) is embedded in the micropores on the cover plate (10) and the first connecting part (21).

21. The top cover assembly according to claim 18, characterized in that, The peripheral surface of the second connecting part (22) and the side surface away from the tab connecting surface (a4) both have micropores. The first insulating part (31) and the second insulating part (32) are formed by nano-injection molding so that the first insulating part (31) is embedded in the micropores on the peripheral surface of the second connecting part (22) and the second insulating part (32) is embedded in the micropores on the side surface of the second connecting part (22) away from the tab connecting surface (a4).

22. The top cover assembly according to claim 18, characterized in that, An insulating cavity is formed between the first connecting part (21) and the cover plate (10), and the third insulating part (33) fills the insulating cavity; The dimension W1 of the insulating cavity in the thickness direction of the cover plate (10) is 0.5 mm to 1.2 mm.

23. The top cover assembly according to any one of claims 1 to 17, characterized in that, The first insulating part (31) includes a first insulator part (311), a second insulator part (313) and a third insulator part (315). The first insulator part (311) is sleeved between the second connecting part (22) and the inner wall of the first through hole (11). The second insulator part (313) is located on the first surface (a1) of the cover plate (10) and is connected to the first insulator part (311). The third insulator part (315) is located on the second surface (a2) of the cover plate (10) and is connected to the first insulator part (311). The outer diameter of the second insulator part (313) and the third insulator part (315) is larger than the radial dimension of the first through hole (11).

24. The top cover assembly according to claim 23, characterized in that, The top cover assembly (100) further includes a second insulating member (40), which is disposed on the side of the cover plate (10) having the second surface (a2) and has a second through hole (41); the third insulator part (315) is located inside the second through hole (41) and has a mating surface (a6) that is in contact with the inner wall of the second through hole (41), and both the inner wall of the second through hole (41) and the mating surface (a6) are inclined relative to the thickness direction of the cover plate (10).

25. The top cover assembly according to any one of claims 1 to 17, characterized in that, The orthographic projection of the first connecting part (21) on the first surface (a1) of the cover plate (10) does not overlap with the first through hole (11), and the distance W2 between the first connecting part (21) and the first through hole (11) in the preset direction (X) is 0 mm to 10 mm; or The orthographic projection of the first connecting part (21) on the first surface (a1) of the cover plate (10) partially overlaps with the first through hole (11), and the portion of the first through hole (11) covered by the orthographic projection of the first connecting part (21) on the first surface (a1) has a size W3 of 0 mm to 10 mm in the preset direction (X).

26. The top cover assembly according to any one of claims 1 to 17, characterized in that, The dimension W4 of the first connecting part (21) in the preset direction (X) is 8mm to 35mm, and the dimension W5 of the cover plate (10) in the preset direction (X) is greater than or equal to 20mm, and W5 is greater than W4; or The dimension W4 of the first connecting part (21) in the preset direction (X) and the dimension W5 of the cover plate (10) in the preset direction (X) satisfy: 20%≤W4 / W5≤50%.

27. The top cover assembly according to any one of claims 1 to 17, characterized in that, The size of the cover plate (10) in the preset direction (X) is W5, the distance between the first connecting part (21) and one side of the cover plate (10) in the preset direction (X) is W6, and W5 and W6 satisfy: 25%≤W6 / W5≤40%.

28. The top cover assembly according to any one of claims 1 to 17, characterized in that, A sealing ring is provided between the first insulating element (30) and the cover plate (10).

29. A single battery cell, characterized in that, It includes a housing (200), a cell assembly (300), and a top cover assembly (100) as described in any one of claims 1 to 28. The housing (200) has a receiving cavity (201) and an opening communicating with the receiving cavity (201). The cover plate (10) covers the opening. The battery cell assembly (300) is disposed in the receiving cavity (201) and has at least two tabs (301) on the side facing the cover plate (10). The tab connecting surface (a4) of each of the second connecting portions (22) is connected to the corresponding tab (301).

30. A battery, characterized in that, Includes the battery cell as described in claim 29.

31. An electrical device, characterized in that, It includes the battery cell as described in claim 29, or the battery as described in claim 30.

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