Top cover assembly and single battery

Abstract

This application discloses a top cover assembly and a single battery cell. The top cover assembly includes a top cover sheet, an electrode post, and a connecting piece. The top cover sheet includes a substrate and a limiting portion. The substrate has a through mounting hole, and the limiting portion is connected to the side of the substrate facing the battery cell. The limiting portion surrounds the mounting hole and defines a limiting space with the substrate. The electrode post includes a main body and a flange. The flange surrounds the main body and is located within the limiting space. Along the axial direction of the electrode post, both ends of the flange abut against the substrate and the limiting portion, respectively, to restrict the movement of the electrode post. The connecting piece includes a first connecting portion and a second connecting portion. The first connecting portion is connected to the electrode post, and the second connecting portion is used to connect to the tab of the battery cell. Along the axial direction, the distance from the first connecting portion to the substrate is greater than the distance from the second connecting portion to the substrate. This embodiment simplifies the structure and assembly process of the top cover assembly and improves the energy density of the battery cell.

Description

Technical Field

[0001] This application relates to the field of energy storage device technology, and in particular to a top cover assembly and a single battery cell. Background Technology

[0002] Currently, with the development of electric vehicles, consumers have increasingly higher requirements for the driving range of electric vehicles. As an energy storage device that provides power to electric vehicles, the energy density of the power battery is a direct factor affecting the driving range. However, common methods to improve the energy density of power batteries, such as increasing the specific capacity of positive and negative electrode active materials, have reached a bottleneck with the development of technology, which restricts the improvement of the driving range of electric vehicles. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a top cover assembly capable of improving the energy density of a battery.

[0004] This application also discloses a single battery cell using the aforementioned top cover assembly.

[0005] The top cover assembly according to the first embodiment of this application includes:

[0006] The top cover sheet includes a substrate and a limiting portion. The substrate has a through mounting hole, and the limiting portion is connected to the side of the substrate facing the battery cell. The limiting portion surrounds the mounting hole and defines a limiting space with the substrate.

[0007] An electrode post includes a main body and a flange. The flange surrounds the main body and is located within the limiting space. Along the axial direction of the electrode post, both ends of the flange abut against the substrate and the limiting portion, respectively, to restrict the movement of the electrode post.

[0008] The connecting piece includes a first connecting portion and a second connecting portion. The first connecting portion is connected to the electrode post, and the second connecting portion is used to connect to the electrode tab of the battery cell. Along the axial direction, the distance from the first connecting portion to the substrate is greater than the distance from the second connecting portion to the substrate.

[0009] The top cover assembly according to the embodiments of this application has at least the following beneficial effects:

[0010] This embodiment can fix the pole post through the limiting part, thereby simplifying the structure and assembly process. At the same time, by setting the first connecting part and the second connecting part with a height difference on the connecting piece, the height of the battery cell can be increased, thereby increasing the energy density of the battery cell.

[0011] In other embodiments of this application, the substrate has a mounting groove on the side facing the battery cell, the mounting groove surrounds the mounting hole, the limiting portion surrounds the mounting groove, and the flange is at least partially located within the mounting groove.

[0012] In other embodiments of this application, the main body includes a first connecting end that extends axially relative to the flange and passes through the mounting hole.

[0013] In other embodiments of this application, the sidewall of the first connecting end is provided with at least one first positioning surface, and the wall of the mounting hole is provided with at least one second positioning surface. The first positioning surface and the second positioning surface are in contact to restrict the rotation of the pole post.

[0014] In other embodiments of this application, the pole post further includes a second connecting end, which is located on the side of the flange facing the battery cell and extends along the axial direction relative to the flange, and the second connecting end is connected to the first connecting portion.

[0015] In other embodiments of this application, the top cover assembly further includes an insulating member located between the pole post and the top cover sheet, for separating the pole post and the top cover sheet.

[0016] In other embodiments of this application, the insulating element includes an insulating layer integrally formed on the outer peripheral surface of the pole post, or the insulating element includes a thermoplastic film covering the outer peripheral surface of the pole post.

[0017] In other embodiments of this application, the top cover assembly further includes a seal located between the flange and the top cover sheet for sealing between the pole post and the top cover sheet.

[0018] In other embodiments of this application, the pole post further includes a second connecting end, which is located on the side of the flange facing the battery cell and extends along the axial direction relative to the flange, and the second connecting end is connected to the first connecting portion;

[0019] The sealing element includes a first sealing portion and a second sealing portion, wherein the first sealing portion is located between the flange and the limiting portion, and the second sealing portion is located between the second connecting end and the limiting portion.

[0020] In other embodiments of this application, the top cover plate further includes an explosion-proof valve mounting hole, and the top cover assembly further includes an explosion-proof valve. The explosion-proof valve includes a mounting portion, a first reinforcing portion, and a deformable portion. The first reinforcing portion is disposed around the deformable portion, and the mounting portion is disposed around the first reinforcing portion and connected to the edge of the explosion-proof valve mounting hole.

[0021] In other embodiments of this application, the top cover sheet further includes an injection hole, and the top cover assembly further includes a sealing pin connected to the top cover sheet to close the injection hole, wherein the outer end face of the sealing pin has a groove.

[0022] In other embodiments of this application, the sealing nail further includes a second reinforcing portion disposed on the bottom wall of the groove.

[0023] The single-cell battery according to the second embodiment of this application includes:

[0024] Battery casing;

[0025] The top cover assembly is connected to the battery housing and defines a mounting cavity with the battery housing;

[0026] The battery cell, located within the mounting cavity, includes a battery cell body and a tab. The battery cell body is disposed corresponding to the second connecting portion, and the tab is electrically connected to the second connecting portion.

[0027] In other embodiments of this application, the single battery cell further includes a tab limiting member, which is located between the cell body and the top cover assembly and has a tab channel;

[0028] The electrode tab is inserted into the electrode tab channel and can be limited by the electrode tab limiting member.

[0029] In other embodiments of this application, the electrode channel includes a first cavity and a second cavity, the electrode includes a folded portion and a protruding portion, the folded portion is located in the first cavity and is electrically connected to the battery cell body, and the protruding portion passes through the second cavity and is electrically connected to the electrode post.

[0030] In other embodiments of this application, the single battery cell further includes a cell protective film, the cell protective film having a first positioning structure, the top cover assembly having a second positioning structure, the cell protective film covering the outside of the cell body, and being positioned by the first positioning structure and the second positioning structure.

[0031] The battery pack according to the third embodiment of this application includes:

[0032] Box;

[0033] The single battery cell is located inside the housing.

[0034] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0035] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0036] Figure 1 This is a perspective view of the top cover assembly in one embodiment of this application;

[0037] Figure 2 for Figure 1 Exploded view of the top cover assembly;

[0038] Figure 3 for Figure 1 Cross-sectional view of the top cover assembly;

[0039] Figure 4 This is an exploded view of the top cover assembly in another embodiment of this application;

[0040] Figure 5 for Figure 4 Cross-sectional view of the top cover assembly;

[0041] Figure 6 This is a perspective view of an explosion-proof valve in one embodiment of this application;

[0042] Figure 7 for Figure 6 Cross-sectional view of a medium-sized explosion-proof valve;

[0043] Figure 8 This is a cross-sectional view of the connection between the sealing pin and the top cover plate in one embodiment of this application;

[0044] Figure 9 for Figure 8 Cross-sectional view of the central sealing pin;

[0045] Figure 10 A cross-sectional view of the sealing pin in another embodiment;

[0046] Figure 11 for Figure 1 Partial cross-sectional view of the connection between the top cover assembly and the battery cell;

[0047] Figure 12 This is a cross-sectional view of the electrode tab limiting member in one embodiment of this application;

[0048] Figure 13 for Figure 12 Cross-sectional view of the connection between the middle electrode retainer and the battery cell;

[0049] Figure 14 This is an exploded view of the cell protective film and the cell in one embodiment of this application.

[0050] Figure label:

[0051] Top cover assembly 100, top cover piece 110, base plate 111, mounting hole 1111, mounting groove 1112, second positioning surface 1113, explosion-proof valve mounting hole 1114, injection hole 1115, limiting part 112, vertical part 1121, horizontal part 1122, pole post 120, main body part 121, first connecting end 1211, second connecting end 1212, first positioning surface 1213, flange 122, connecting piece 130, first connecting part 131, second connecting part 132, insulating part 140, sealing part 150, first sealing part 151, second sealing part 152, plastic part 160, protrusion 161, explosion-proof valve 170, mounting part 171, first reinforcing part 172, bending part 1721, deformable part 173, sealing nail 180, groove 181, second reinforcing part 182, side 183;

[0052] Battery cell 200, battery cell body 210, electrode tab 220;

[0053] Electrode limiting component 300, electrode channel 310, first cavity 311, second cavity 312;

[0054] Cell protective film 400, notch 410. Detailed Implementation

[0055] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0056] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this application.

[0057] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0058] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0059] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] Reference Figure 1 , Figure 2 The top cover assembly 100 includes a top cover plate 110, a terminal post 120, and a connecting piece 130. The top cover plate 110 is used to seal the battery casing of a single cell. The terminal post 120 and the connecting piece 130 are used together to realize the electrical connection between the internal cell and the external electrical device. The following is a detailed description in conjunction with the accompanying drawings.

[0061] For ease of description, this application defines the possible directions in the top cover assembly 100 as follows: for a component, the side facing the battery cell is described as the lower side, and the side away from the battery cell is described as the upper side. When axial and radial directions are involved, unless otherwise specified, they refer to the axial and radial directions of the pole post 120.

[0062] Reference Figure 3 The top cover plate 110 includes a substrate 111 and a limiting part 112. The substrate 111 is generally a flat plate structure, made of metal materials such as aluminum, which has both electrical conductivity and a certain strength to mount the pole post 120. The substrate 111 is provided with a mounting hole 1111 that runs through the axial direction, and the mounting hole 1111 is used to mount the pole post 120. The limiting part 112 is provided with a side of the substrate 111 facing the battery cell (i.e., the lower side) for fixing the electrode post 120. Specifically, a cylindrical thin-walled structure is formed on the lower surface of the substrate 111. The thin-walled structure is arranged around the mounting hole 1111, and the lower part of the thin-walled structure is bent radially inward. At this time, the limiting part 112 includes a vertical part 1121 and a horizontal part 1122. The limiting part 112 and the substrate 111 can define a limiting space to accommodate the flange 122 of the electrode post 120. The horizontal part of the electrode post 120 can abut and limit the electrode post 120, thereby fixing the electrode post 120.

[0063] One end of the terminal post 120 is used for electrical connection to the electrode tab of the battery cell, and the other end is used for electrical connection to an external electrical device. The terminal post 120 is a copper-aluminum composite cylinder; in some specific embodiments, its upper part is an aluminum plate and its lower part is a copper plate. Using a composite plate structure can reduce the height of the terminal post 120. (Refer to...) Figure 2 The pole post 120 includes a main body 121 and a flange 122, wherein the flange 122 is disposed around the main body 121 and is used to cooperate with the limiting part 112 to fix the pole post 120. (See reference...) Figure 3 The main body 121 includes a first connecting end 1211, which protrudes from the mounting hole 1111, allowing the first connecting end 1211 to be connected to an external electrical device. It should be noted that the first connecting end 1211 protruding from the mounting hole 1111 means that the first connecting end 1211 is in a contactable state, allowing it to... Figure 3 The flange 122 shown protrudes axially and is located within the mounting hole 1111, or it can be flush with the flange 122 axially.

[0064] The flange 122 is located within the limiting space, and both ends of its axial direction are provided with planes. The flange 122 abuts against the lower surface of the substrate 111 through the upper plane and abuts against the horizontal portion 1122 of the limiting part 112 through the lower plane. This can limit the axial movement of the pole post 120. At the same time, the pole post 120 can cooperate with the top cover plate 110 for radial limiting. For example, the flange 122 abuts against the vertical portion 1122 of the limiting part 112, or the first connecting end 1211 abuts against the wall of the mounting hole 1111. As can be seen from the above, the pole post 120 of this embodiment can be completely fixed by relying solely on the top cover plate 110 without the need for additional connecting components. This simplifies the structure of the top cover assembly 100, thereby reducing costs and the weight of the top cover assembly 100. On the other hand, the limiting part 112 can fix the pole post 120 through a simple riveting process. Compared with the solution that requires welding or other processes to connect the pole post 120 and the top cover plate 110, this embodiment can also simplify the process and improve assembly efficiency.

[0065] It should be noted that when the pole post 120 and the top cover plate 110 are described as abutting, it means that the two abut each other through a component with insulating ability, so as to avoid direct conduction between the pole post 120 and the top cover plate 110.

[0066] The connecting piece 130 is made of conductive materials such as metal and is used to realize the electrical connection between the battery cell tab and the terminal 120, as shown in the figure. Figure 2 , Figure 3The connecting piece 130 extends approximately in the left-right direction shown in the figure, with one end (e.g., the left end) welded to the terminal post 120 and the other end (e.g., the right end) welded to the electrode tab of the battery cell. The connecting piece 130 is connected to the terminal post 120 by laser welding, and the connecting piece 130 is connected to the electrode tab by ultrasonic welding. Figure 3 As shown, since the limiting part 112 is located on the lower side of the substrate 111, that is, extending towards the cell, the limiting part 112 will encroach on a portion of the internal space of the battery, resulting in a reduction in the height of the cell, which is not conducive to improving the energy density of a single cell. Based on this, the connecting piece 130 of this embodiment includes a first connecting part 131 and a second connecting part 132, wherein the first connecting part 131 is connected to the electrode post 120, and along the radial direction of the electrode post 120, the second connecting part 132 is located on one side of the first connecting part 131 and is used to connect to the electrode tab of the cell. Meanwhile, referring to... Figure 3 Along the axial direction of the electrode post 120, let h1 be the distance from the first connecting part 131 to the substrate 111 and h2 be the distance from the second connecting part 132 to the substrate 111. The two satisfy: h1 > h2. That is, since the second connecting part 132 is offset from the limiting part 112, it can be closer to the substrate 111. In this way, the battery cell can be placed below the second connecting part 132, so that the height of the battery cell can be increased by Δh (Δh = h1 - h2), thereby increasing the energy density of the battery cell. In combination with the above, this embodiment can not only fix the electrode post 120 through the limiting part 112, thereby simplifying the structure and assembly process, but also increase the height of the battery cell, thereby increasing the energy density of the battery cell.

[0067] As shown in the figure, the first connecting part 131 and the second connecting part 132 can be bent parts formed by stamping process.

[0068] It should be noted that the top cover assembly 100 typically also includes other auxiliary structures, such as Figure 2 , Figure 3 The plastic part 160 shown is generally a plate-shaped structure and is connected to the underside of the top cover plate 110.

[0069] In some embodiments, refer to Figure 2 , Figure 3The substrate 111 also has a mounting groove 1112 on the side facing the battery cell 200. That is, the thickness of the part of the substrate 111 with the mounting groove 1112 is less than the thickness of other parts. The mounting groove 1112 is adapted to the shape of the mounting hole 1111 and is arranged around the mounting hole 1111. The limiting part 112 is arranged around the mounting groove 1112. Specifically, the vertical part 1121 of the limiting part 112 is arranged along the edge of the mounting groove 1112. That is, the mounting groove 1112 constitutes part of the limiting space. The flange 122 is at least partially located within the mounting groove 1112, which allows the flange 122 to be completely hidden inside the top cover plate 110, or at least reduces the height of the flange 122 protruding from the lower surface of the top cover plate 110. This reduces the height of the limiting portion 112 protruding from the lower surface of the top cover plate 110, thereby reducing the overall height of the top cover assembly 100. With a fixed total height of a single battery cell, if the height of the top cover assembly is reduced, the space inside the single battery cell for placing the battery cell will be larger, which can also increase the energy density of the single battery cell.

[0070] In some embodiments, refer to Figure 3 The first connecting end 1211 extends axially relative to the flange 122, establishing a reference plane parallel to the radial direction of the pole post 120. The projection of the first connecting end 1211 on this reference plane is located within the projection of the flange 122 on this reference plane, thus forming a first stepped surface at the connection between the first connecting end 1211 and the flange 122. The first connecting end 1211 passes through the mounting hole 1111 and can achieve radial positioning of the pole post 120 by abutting against the wall of the mounting hole 1111. In addition, the pole post 120 can be installed in the internal space of the top cover plate 110, so that the pole post 120 and the top cover plate 110 partially overlap in the height direction. With a fixed total height of the pole post 120, the total height of the top cover assembly 100 can be reduced, thereby allowing the single battery to accommodate a larger volume cell.

[0071] When the first connecting end 1121 passes through the mounting hole 1111, the upper surface of the first connecting end 1121 can be flush with the upper surface of the substrate 111, lower than the upper surface of the substrate 111, or slightly higher than the upper surface of the substrate 111. For the latter two cases, the height difference between the first connecting end 1121 and the substrate 111 should be controlled within a set range. For example, the height of the first connecting end 1121 above the substrate 111 should be within 1 mm to 3 mm to avoid the height difference being too large and increasing the total height of the top cover assembly 100.

[0072] Based on the above embodiments, referring to Figure 2The first connecting end 1211 has at least one first positioning surface 1213 on its sidewall, and the mounting hole 1111 has at least one second positioning surface 1113 on its wall. When the first connecting end 1211 is located inside the mounting hole 1111, the first positioning surface 1213 and the second positioning surface 1113 fit together, thereby restricting the rotation of the pole post 120. Of course, multiple positioning surfaces can be provided on both the first connecting end 1211 and the mounting hole 1111 to enhance the positioning effect. For example, the first connecting end 1211 is a roughly rectangular protrusion in the figure, and the mounting hole 1111 is a corresponding rectangular hole.

[0073] In some embodiments, refer to Figure 3 The pole post 120 also includes a second connecting end 1212, which extends axially relative to the flange 122. A reference plane parallel to the radial direction of the pole post 120 is also established. The projection of the second connecting end 1212 on the reference plane is located within the projection of the flange 122 on the reference plane. This forms a second stepped surface at the connection between the second connecting end 1212 and the flange 122. The lower surface of the flange 122 abuts against the horizontal surface of the second stepped surface, thereby restricting the downward movement of the pole post 120. Based on the above structure, the horizontal portion 1122 of the limiting portion 112 can be partially or entirely located in the annular groove between the flange 122 and the second connecting end 1212, thereby reducing the height of the limiting portion 112 protruding from the lower surface of the pole post 120 and thus reducing the total height of the top cover assembly 100.

[0074] In some embodiments, the top cover assembly 100 further includes an insulating member 140 located between the terminal post 120 and the top cover plate 110, used to separate the terminal post 120 and the top cover plate 110, preventing direct contact between the terminal post 120 and the top cover plate 110 and thus avoiding a short circuit. Typically, the contact area between the terminal post 120 and the top cover plate 110 is concentrated on the outer peripheral surface of the terminal post 120. The insulating member 140 can completely cover the outer peripheral surface of the terminal post 120, that is, the terminal post 120 and the top cover plate 110 are completely isolated by the insulating member 140. Alternatively, the insulating member 140 can cover a portion of the outer peripheral surface of the terminal post 120, that is, the terminal post 120 and the top cover plate 110 are isolated by the insulating member 140 and other components such as the sealing member 150 described below.

[0075] The insulating element 140 can be formed in various ways. In some embodiments, the insulating element 140 is an insulating layer formed on the outer peripheral surface of the electrode post 120 by an integral molding process, such as a plastic layer formed by injection molding or a ceramic layer formed by sintering. In other embodiments, the insulating element 140 can also be a thermoplastic film covering the outer peripheral surface of the electrode post 120. The thermoplastic film can shrink and fit the electrode post 120 after being heated, which can adapt to the outer contour shape of the electrode post 120, has a high degree of fit with the electrode post 120, and is convenient and quick to operate.

[0076] Specifically, refer to Figure 2 When the first connecting end 1211 of the pole post 120 is a rectangular structure and the flange 122 is a circular structure, the overall shape of the pole post 120 changes greatly, and the insulation layer is prone to breakage when using thermoplastic film for overall isolation. Therefore, the illustrated embodiment uses a plastic layer injection molded on the outside of the pole post 120 as an insulation layer. The connection strength between the plastic layer and the pole post 120 is relatively high, and it has better insulation performance.

[0077] Reference Figure 4 , Figure 5 When the pole post 120 is a rotating body with the vertical axis as the axis of rotation, a thermoplastic film covering the outer circumference of the pole post 120 can be used as an insulating component 140.

[0078] In some embodiments, the top cover assembly 100 further includes a seal 150 located between the flange 122 and the top cover plate 110 for sealing between the pole post 120 and the top cover plate 110. Since the limiting portion 112 abuts against the flange 122 radially, the seal 150 is disposed at least between the limiting portion 112 and the flange 122, or between the substrate 111 and the flange 122, such that the seal 150 can be compressed to produce elastic deformation.

[0079] exist Figure 3 In the illustrated embodiment, the pole post 120 includes a second connecting end 1212 extending from the lower surface of the flange 122, and there is a gap between the second connecting end 1212 and the horizontal portion 1122 of the limiting portion 112. Correspondingly, the seal 150 includes a first sealing portion 151 and a second sealing portion 152. The first sealing portion 151 is horizontally disposed between the flange 122 and the limiting portion 112, and the second sealing portion 152 is vertically disposed between the second connecting end 1212 and the limiting portion 112. This improves the sealing performance of the seal 150.

[0080] It should be noted that, Figure 3 The insulating element 140 is located on the outer side of the first connecting end 1211, the upper surface of the flange 122, and the outer side of the flange 122, respectively. The sealing element 150 is located on the lower side of the flange 122 and the outer side of the second connecting end 1212, respectively. That is, in this embodiment, the pole post 120 and the top cover plate 110 are insulated together by the insulating element 140 and the sealing element 150.

[0081] exist Figure 5 In the embodiment shown, the outer surface of the pole post 120 is completely covered by the insulating member 140, and the sealing member 150 is disposed between the lower side of the flange 122 and the limiting part 112. Of course, the sealing member 150 can also be disposed between the upper surface of the flange 122 and the substrate 111.

[0082] Reference Figure 2 and Figure 4 The top cover plate 110 also includes an explosion-proof valve mounting hole 1114, and the top cover assembly 100 also includes an explosion-proof valve 170. The explosion-proof valve 170 is mounted on the top cover plate 110 to seal the explosion-proof valve mounting hole 1114. When a fault occurs inside the battery, causing the internal pressure to rise to a set range, the explosion-proof valve 170 will burst open to release pressure, thereby reducing the risk of battery explosion. The explosion-proof valve 170 is usually fixedly connected to the edge of the explosion-proof valve mounting hole 1114 by welding. When the internal pressure of the battery gradually increases, the explosion-proof valve 170 will first bulge outward, and drive the aforementioned edge to bulge outward simultaneously. This will change the force mode of the explosion-proof valve 170, posing a safety hazard that the explosion-proof valve 170 may not burst open when the detonation range is reached. Based on this, referring to... Figure 6 , Figure 7 This embodiment proposes an improved explosion-proof valve structure, including a mounting part 171, a first reinforcing part 172, and a deformable part 173. The first reinforcing part 172 is arranged around the deformable part 173, and the mounting part 171 is arranged around the first reinforcing part 172. The deformable part 173 is used to burst open after bearing pressure. The mounting part 171 is used to connect with the edge of the explosion-proof valve mounting hole 1114. The first reinforcing part 172 can increase the local strength of the explosion-proof valve 170 and reduce the amount of deformation transmitted from the deformable part 173 to the top cover plate 110, so that the explosion-proof valve 170 can burst open normally after bearing a preset pressure.

[0083] Among them, reference Figure 7 The first reinforcing portion 172 may include an annular bent portion 1721, which may be formed, for example, by stamping, in which case the wall thickness of the first reinforcing portion 172 remains substantially constant. In some specific embodiments, the first reinforcing portion 172 includes a plurality of bent portions 1721 along the radial direction of the pole post 120, and the plurality of bent portions 1721 form a wave structure.

[0084] As an alternative to the above solution, the first reinforcing part 172 may also include more than one protrusion, that is, the wall thickness of the first reinforcing part 172 at the protrusion is greater than the wall thickness at other locations.

[0085] Furthermore, the wall thickness of the mounting part 171 can be greater than the wall thickness of the deformable part 173, so that the mounting part 171 has stronger resistance to deformation.

[0086] Reference Figure 8 , Figure 9The top cover plate 110 is also provided with an injection hole 1115, through which external electrolyte is injected into the battery. After the injection is completed, the injection hole 1115 is sealed by a sealing pin 180. Typically, the sealing pin 180 is welded to the top cover plate 110 by circumferential welding. The internal stress from welding may cause the sealing pin 180 to warp. To improve this problem, in some embodiments, the outer end face of the sealing pin 180 is also provided with a groove 181, making the sealing pin 180 a thin-shell structure. During installation, the sealing pin 180 is welded to the inner circumferential surface of the injection hole 1115 via its side 183. Even in the event of localized internal stress concentration, the sealing pin 180 can absorb the internal stress through a certain deformation, thereby reducing warping. The groove 181 on the sealing pin 180 can be formed by stamping.

[0087] Reference Figure 10 The sealing nail 180 also includes a second reinforcing part 182, which is disposed on the bottom wall of the groove 181. The second reinforcing part 182 can enhance the deformation resistance of the bottom wall, so that the deformation is concentrated on the circumferential side wall of the sealing nail 180. Specifically, the second reinforcing part 182 can be an annular bend or a protrusion. It should be noted that the bend can be formed by stamping, so that the sealing nail 180 as a whole can be manufactured by stamping, which is convenient for processing.

[0088] This application also proposes a single battery, including a battery casing (not shown), a top cover assembly 100 and a battery cell 200. The top cover assembly 100 is connected to the opening of the battery casing by welding or other means, thereby defining a mounting cavity together with the battery casing, and the battery cell 200 is located in the mounting cavity.

[0089] Reference Figure 11 The battery cell 200 mainly includes a battery cell body 210 and a tab 220. The battery cell body 210 is disposed corresponding to the second connecting portion 132, specifically located below the second connecting portion 132. Since the second connecting portion 132 is higher than the first connecting portion 131, the top of the battery cell body 210 can extend further upward, thereby increasing the height of the battery cell body 210. One end of the tab 220 is electrically connected to the battery cell body 210, and the other end is electrically connected to the second connecting portion 132.

[0090] In some embodiments, adhesive tape is typically applied to both sides of the tab 220 to achieve positioning and insulation. However, when the adhesive tape is exposed to the electrolyte environment for a long time, it is prone to losing its adhesiveness and falling off, leaving the tab 220 in a free state. This can lead to the tab 220 becoming embedded in the separator during battery production and use, potentially causing battery fires, explosions, and other problems. To address these issues, the single-cell battery in this embodiment also includes a tab limiting member 300. The tab limiting member 300 can limit the tab 220 and will not fail due to the electrolyte environment.

[0091] Specific reference Figure 12 , Figure 13 A tab limiting member 300 is disposed between the cell body 210 and the top cover assembly 100, and can be made of a rigid material that can withstand the electrolyte environment. The tab limiting member 300 has a tab channel 310 inside, one end of which extends to the upper surface of the cell body 210, and the other end extends to the electrode post 121. The main structure of the tab 220 is located in the tab channel 310, with its upper end extending out of the tab channel 310 to connect to the electrode post 121. The width of the tab channel 310 is slightly larger than the width of the corresponding tab 220, thus allowing the tab 220 to pass through while restricting its displacement to prevent it from inserting into the diaphragm.

[0092] Typically, to reduce the space occupied by the tab 220, the section of the tab 220 near the cell body 210 is folded. The folded portion of the tab 220 is described as a folded portion 221, and the undisturbed portion as a protrusion 222. The folded portion 221 is located on the upper surface of the cell body 210, with one end connected to the cell body 210 and the other end connected to the protrusion 222. The other end of the protrusion 222 is connected to the terminal post 121. To accommodate this tab 220, in some embodiments, the tab channel 310 includes a first cavity 311 and a second cavity 312. The first cavity 311 is close to the cell body 210, and the second cavity 312 is close to the terminal post 121, arranged generally in a vertical direction. Along the width direction of the cell body 210 (i.e.,...) Figure 13 (in the left-right direction), the width of the first cavity 311 is greater than that of the second cavity 312. During installation, the folded part 221 of the electrode ear is housed in the first cavity 311, the protruding part 222 passes through the second cavity 312, and the top end protrudes from the second cavity 312 and is electrically connected to the electrode post 121.

[0093] In some embodiments, along the direction away from the upper surface of the cell body 210 (i.e.) Figure 13From bottom to top, the width of the folded portion 221 gradually decreases, so the width of the first cavity 311 also decreases accordingly to ensure the limiting effect on the folded portion 221. The width of the second cavity 312 remains constant, which is suitable for limiting the folded tab 220.

[0094] In some embodiments, the overall width of the tab limiting member 300 gradually decreases from bottom to top. This adapts to the shape of the internal tab channel 310, preventing excessive differences in wall thickness between different parts of the tab limiting member 300, which would hinder molding by injection molding or other methods. It also reduces the volume of the tab limiting member 300. The lower end face of the tab limiting member 300 can be a plane, parallel to the upper end face of the cell body 210, and its width is equal to or slightly less than the width of the upper end face, allowing the tab limiting member 300 to be stably placed above the cell body 210.

[0095] Individual battery cells typically also have a cell protective film for insulation protection. During actual production, this protective film is prone to displacement, exceeding the top cover plate 110, leading to quality problems in subsequent welding processes. To address this issue, in some embodiments, the cell protective film can be positioned using a positioning structure. Specifically, the cell protective film 400 has a first positioning structure, and components in the top cover assembly 100, such as the plastic part 160, have a second positioning structure. The cell protective film 400 is positioned using both the first and second positioning structures to prevent displacement. The positioning of the cell protective film 400 by the first and second positioning structures includes: circumferential positioning of the cell protective film 400 relative to the top cover assembly 100, axial positioning of the cell protective film 400 relative to the top cover assembly 100 along the electrode post 120, and a combination of both positioning methods.

[0096] In some specific embodiments, one of the first positioning structure and the second positioning structure is a protruding structure, and the other is a recessed structure. The protruding structure is positioned by being embedded into the recessed structure. Figure 14Taking the example shown, the first positioning structure is a notch 410 located on the upper edge of the battery cell protective film 400, and the second positioning structure is a protrusion 161 located on the side of the plastic part 160. During assembly, the battery cell protective film 400 is sleeved on the outside of the battery cell body 210, and the battery cell protective film 400 and the plastic part 160 are positioned by the protrusion 161 and the notch 410. At this time, the position between the battery cell protective film 400 and the top cover plate 110 is determined, and it cannot move circumferentially along the top cover plate 110, nor can it move axially along the electrode post 120, to prevent the battery cell protective film 400 from exceeding the top cover plate 110. After the battery cell protective film 400 is positioned, the upper end of the battery cell protective film 400 is welded to the top cover plate 110 by means of laser welding, etc., so as to fix the battery cell protective film 400. The above method can effectively avoid welding quality problems caused by positional misalignment between the battery cell protective film 400 and the top cover plate 110.

[0097] Reference Figure 14 Each side of the battery cell protective film 400 can be provided with a first positioning structure, and each side of the plastic part 160 can be provided with a second positioning structure, thereby enhancing the positioning effect.

[0098] It should be noted that the cell protective film 400 is a thin film structure with a generally uniform wall thickness, while the plastic part 160 is an injection molded structure, and its shape can be flexibly adjusted according to the design. Therefore, it is easier to process the notch 410 and the bump 161 on the cell protective film 400 and the plastic part 160 respectively.

[0099] This application also proposes a battery pack, including a housing and individual batteries from the above embodiments. The individual batteries are located inside the housing. It should be noted that the housing can be an integral housing structure or a split housing structure formed by splicing together mounting structures such as side panels.

[0100] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. A top cover assembly, characterized in that, include: The top cover sheet includes a substrate and a limiting portion. The substrate has a through mounting hole, and the limiting portion is connected to the side of the substrate facing the battery cell. The limiting portion surrounds the mounting hole and defines a limiting space with the substrate. An electrode post includes a main body and a flange. The flange surrounds the main body and is located within the limiting space. Along the axial direction of the electrode post, both ends of the flange abut against the substrate and the limiting part, respectively, to restrict the movement of the electrode post. The connecting piece includes a first connecting portion and a second connecting portion. The first connecting portion is connected to the electrode post, and the second connecting portion is used to connect to the electrode tab of the battery cell. Along the axial direction of the electrode post, the distance from the first connecting portion to the substrate is greater than the distance from the second connecting portion to the substrate. The top cover assembly also includes an insulating component located between the pole post and the top cover sheet, which is used to separate the pole post and the top cover sheet; The top cover assembly also includes a seal located between the flange and the top cover plate for sealing between the pole post and the top cover plate.

2. The top cover assembly according to claim 1, characterized in that, The substrate also has a mounting groove on the side facing the battery cell, the mounting groove surrounds the mounting hole, the limiting portion surrounds the mounting groove, and the flange is at least partially located within the mounting groove.

3. The top cover assembly according to claim 1, characterized in that, The main body includes a first connecting end, which extends axially relative to the flange along the pole post and passes through the mounting hole.

4. The top cover assembly according to claim 3, characterized in that, The sidewall of the first connecting end is provided with at least one first positioning surface, and the wall of the mounting hole is provided with at least one second positioning surface. The first positioning surface and the second positioning surface are in contact to restrict the rotation of the pole post.

5. The top cover assembly according to claim 1, characterized in that, The electrode post further includes a second connecting end, which is located on the side of the flange facing the battery cell and extends axially relative to the flange along the electrode post. The second connecting end is connected to the first connecting portion.

6. The top cover assembly according to claim 1, characterized in that, The insulating element includes an insulating layer integrally formed on the outer peripheral surface of the pole post, or the insulating element includes a thermoplastic film covering the outer peripheral surface of the pole post.

7. The top cover assembly according to claim 1, characterized in that, The electrode post further includes a second connecting end, which is located on the side of the flange facing the battery cell and extends axially relative to the flange along the electrode post. The second connecting end is connected to the first connecting portion. The sealing element includes a first sealing portion and a second sealing portion, wherein the first sealing portion is located between the flange and the limiting portion, and the second sealing portion is located between the second connecting end and the limiting portion.

8. A single-cell battery, characterized in that, include: Battery casing; The top cover assembly according to any one of claims 1 to 7 is connected to the battery housing and defines a mounting cavity with the battery housing; The battery cell, located within the mounting cavity, includes a battery cell body and a tab. The battery cell body is disposed corresponding to the second connecting portion, and the tab is electrically connected to the second connecting portion.

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