Top cover assembly of battery cell, battery cell and battery

Abstract

The utility model provides a top cover assembly of a battery cell, the battery cell and a battery, and relates to the technical field of batteries. The top cover assembly of the battery cell comprises a top cover piece and a reinforcing block, an assembling part is arranged on the top cover piece, and the assembling part is of a groove structure; the reinforcing block is installed on the assembling part. According to the top cover assembly provided by the invention, the reinforcing block is mounted on the top cover piece, so that the main body part of the top cover assembly is formed by combining the top cover piece and the reinforcing block, compared with a single top cover piece, the deformation resistance of the combined top cover assembly is improved, and the deformation resistance of the top cover assembly is improved under the conditions of thermal runaway and the like. The probability of occurrence of conditions such as airtight failure between the positive and negative electrode output terminals and the top cover plate and delayed opening of an anti-explosion valve caused by deformation of the top cover plate due to internal pressure of the battery cell is reduced, and the reliability and the safety of the battery cell in use are improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and in particular to a top cover assembly of a battery cell, a battery cell, and a battery. Background Art

[0002] At present, the most commonly used cell for power batteries is a square hard shell structure. The cell shell of this structure includes a shell and a top cover assembly. The shell and the top cover assembly are sealed and connected to seal and isolate the electrochemical part inside the shell from the external environment.

[0003] The top cover assembly typically includes a top cover sheet, as well as positive and negative output terminals and a pressure relief explosion-proof valve mounted on the top cover sheet. The positive and negative output terminals are sealed to the top cover sheet, allowing the electrode assembly's electrical energy to be drawn out of the enclosed space. The explosion-proof valve opens to release gas from the battery cell when the internal pressure reaches a certain value, preventing explosions and allowing for the targeted discharge of harmful gases. After the top cover sheet connects the positive and negative output terminals to the internal positive and negative tabs, it is welded to the perimeter of the housing to achieve assembly and sealing.

[0004] The top cover of the existing square battery cell will bulge outward after gas is generated inside the battery cell. The top cover cell is constrained by the shell on all sides and the deformation is small. The farther away from the shell (closer to the middle of the top cover cell), the larger the deformation will be. The deformation of the top cover cell will cause the following problems: 1. The sealing between the top cover cell and the positive and negative output terminals becomes worse, and gas leakage inside the shell is likely to occur; 2. Since the deformation of the top cover cell will divert part of the pressure, the opening pressure of the explosion-proof valve will increase, and the explosion-proof valve will delay opening. When the valve is opened, the pressure inside the battery cell exceeds the standard, which is prone to explosion, resulting in an increased risk of the battery cell.

[0005] Therefore, there is an urgent need for a battery cell structure that can reduce the deformation of the top cover sheet to improve the reliability and safety of the battery cell. Utility Model Content

[0006] The present application provides a top cover assembly of a battery cell, a battery cell and a battery to solve the problem that the existing battery cell top cover sheet is easily deformed, thereby improving the reliability and safety of the battery cell during use.

[0007] In a first aspect, the present application provides a top cover assembly of a battery cell, comprising a top cover sheet and a reinforcement block. The top cover sheet is provided with an assembly portion, which is configured as a groove structure; the reinforcement block is mounted on the assembly portion.

[0008] The top cover assembly provided in the first aspect of the present application is characterized in that a reinforcement block is installed on the top cover sheet so that the main part of the top cover assembly is composed of a top cover sheet and a reinforcement block. Compared with a single top cover sheet, once one side of the combined top cover assembly is subjected to air pressure impact, in order for it to deform, the top cover sheet and the reinforcement block need to be deformed at the same time, and the relative stress between the top cover sheet and the reinforcement block needs to be overcome. Therefore, the deformation resistance of the top cover sheet is increased, thereby reducing the probability of airtight failure between the positive and negative output terminals and the top cover sheet and delayed opening of the explosion-proof valve caused by deformation of the top cover sheet due to the internal pressure of the battery cell in cases of thermal runaway, thereby improving the reliability and safety of the battery cell during use.

[0009] In a possible design, the top cover sheet has a transverse centerline, which is a centerline bisecting the inner side or outer side of the top cover sheet along its width direction; the assembly portion is at least partially located on the transverse centerline.

[0010] With the above solution, the transverse centerline is the most central position of the roof sheet in the width direction, and the area where the transverse centerline lies includes the area of ​​the roof sheet most susceptible to deformation. The assembly portion is at least partially located on the transverse centerline. When the reinforcement block is located at the assembly portion, the area of ​​the roof sheet most susceptible to deformation is reinforced by the reinforcement block, making deformation more difficult, thereby enhancing the overall deformation resistance of the roof sheet.

[0011] In a possible design, in any direction except the thickness of the reinforcement block, the dimension M of the reinforcement block and the dimension N of the assembly portion satisfy: M≤N+0.2 mm.

[0012] Through the above solution, the size of the reinforcement block in any direction is controlled within a range of 0.2 mm larger than the assembly portion, making it relatively easy to install the reinforcement block into the assembly portion without the possibility of failure to install.

[0013] In a possible design, the thickness of the reinforcement block is less than or equal to the depth of the mounting portion.

[0014] With the above solution, after the reinforcement block is installed in the assembly portion, it will not protrude from the surface of the top cover piece, so no additional space is required, and the volume of the top cover assembly is reduced.

[0015] In a possible design, the material strength of the reinforcement block is greater than or equal to the material strength of the roof sheet.

[0016] Through the above solution, the strength of the reinforcement block itself is relatively large. Therefore, the addition of the reinforcement block will not lead to a decrease in the local strength of the top cover sheet, thereby not reducing the local strength of the top cover assembly, and the deformation of the top cover assembly will be more difficult.

[0017] In a possible design, the number of the assembly parts is one or more, and correspondingly, the number of the reinforcement blocks is one or more.

[0018] Through the above scheme, one or more assembly parts can be arranged according to the distribution of other components on the top cover piece, so that the setting position and number of the reinforcement blocks are more flexible, which is conducive to the reasonable configuration of the number and position of the reinforcement blocks without affecting the original structural characteristics of the top cover assembly, so as to enhance the strength of the top cover assembly.

[0019] In a possible design, the assembly portion is provided on the inner side or the outer side of the top cover sheet, the inner side being the side close to the inner side of the battery cell shell, and the outer side being the side close to the outer side of the battery cell shell.

[0020] With the above solution, the reinforcement block can be positioned on either the inside or outside of the top cover sheet, corresponding to the assembly portion, providing greater flexibility in its placement. Regardless of whether the reinforcement block is positioned on the inside or outside of the top cover sheet, it can enhance the strength of the top cover sheet to a certain extent, reducing or even eliminating deformation of the top cover sheet, thereby improving the reliability and safety of the battery cell during use.

[0021] In a possible design, the reinforcement block is assembled to the assembly portion of the roof panel by welding, screwing, or riveting.

[0022] Through the above solution, the reinforcement block and the top cover piece can be connected together by any of the above simpler methods, which reduces the difficulty of assembling the reinforcement block and the top cover piece.

[0023] In a second aspect, the present application provides a battery cell comprising a shell, an electrode assembly and a top cover assembly in any of the above embodiments, wherein the top cover assembly is sealed around the opening of the shell, and the electrode assembly is disposed in the space enclosed by the top cover assembly and the shell.

[0024] Through the above scheme, the battery cell adopting the top cover assembly in any of the above embodiments is not prone to leakage of chemical substances from the top cover assembly during use, and when thermal runaway occurs, the probability of delayed opening of the explosion-proof valve is small, and the reliability and safety of the battery cell are improved.

[0025] In a third aspect, the present application provides a battery comprising the battery cell in the above embodiment.

[0026] The beneficial effects of the battery cells and batteries provided in the above-mentioned second and third aspects and the various possible designs of the above-mentioned second and third aspects can be referred to the beneficial effects brought about by the above-mentioned first aspect and the top cover assembly in the various possible embodiments of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1A schematic diagram of the exploded structure of a top cover assembly provided in one embodiment of the present application.

[0028] Figure 2 This is a cross-sectional view of the top cover assembly in the exploded state.

[0029] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0030] Figure 4 A schematic diagram of the exploded structure of a battery cell provided in one embodiment of the present application.

[0031] Figure 5 A schematic diagram of the exploded structure of another top cover assembly provided in one embodiment of the present application.

[0032] Figure 6 A schematic diagram of the exploded structure of another top cover assembly provided in one embodiment of the present application.

[0033] Explanation of reference numerals: 100, top cover assembly; 110, top cover sheet; 111, assembly portion; 120, reinforcement block; 130, transverse center line; 200, shell; 300, electrode assembly. DETAILED DESCRIPTION

[0034] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification, claims and drawings of this application are intended to cover non-exclusive inclusions.

[0036] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiment" in various places in the specification does not necessarily refer to the same embodiment, nor does it necessarily refer to independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0037] The directional words appearing in the following description are all directions shown in the drawings, and do not limit the specific structure of the top cover assembly or battery cell of this application. For example, in the description of this application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, and 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 direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on this application.

[0038] In addition, the terms "first", "second", etc. in the description and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order, and may explicitly or implicitly include one or more such features.

[0039] In the description of this application, unless otherwise specified, "plurality" means more than two (including two), and similarly, "multiple groups" means more than two (including two).

[0040] In the description of this application, it should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, "connected" or "connected" in a mechanical structure can refer to a physical connection. For example, a physical connection can be a fixed connection, such as a fixed connection via screws, bolts, or other spacers; a physical connection can also be a removable connection, such as a snap-fit ​​connection; or an integral connection, such as a connection formed by welding, bonding, or integral molding. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances. "Connected" or "connected" in a circuit structure can refer not only to a physical connection, but also to an electrical connection or a signal connection. For example, it can be a direct connection, i.e., a physical connection, or an indirect connection through at least one intermediate component, as long as circuit connectivity is achieved. It can also refer to internal communication between two components. A signal connection can refer not only to signal connection through an electrical circuit, but also to signal connection through a media medium, such as radio waves. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0041] A battery cell is the basic unit that makes up a battery. It can be used alone to provide power to electrical equipment, or multiple cells can be used in combination. When multiple battery cells are used in combination, the multiple battery cells can be electrically connected in series, in parallel, or in a combination of series and parallel, and can communicate with a battery management system to form a battery pack. The battery management system controls and monitors the working status of each battery cell. In addition, multiple battery cells can also be connected in series and / or in parallel first, and then formed into a battery module with a module management system. Multiple battery modules can then be electrically connected in series, in parallel, or in a combination of series and parallel, and together with the battery management system, form a battery pack.

[0042] Typically, a battery cell includes a shell, an electrode assembly, and a top cover assembly. The shell and the top cover assembly are connected to form a sealed accommodating cavity, and the electrode assembly is accommodated in the accommodating cavity.

[0043] The electrode assembly is the smallest unit in a battery where electrochemical reactions occur, enabling the charging and discharging of the battery cell. It typically includes a positive electrode sheet, a negative electrode sheet, and a separator that separates the positive and negative electrodes. After the electrode assembly is placed in a housing, an electrolyte is injected into the housing. The electrolyte penetrates the interior of the electrode assembly, providing an ion migration pathway for the electrochemical reaction and acting as a conductor.

[0044] The top cover assembly typically includes a top cover sheet and output terminals connected to the top cover sheet. The output terminals are divided into positive and negative output terminals. The positive output terminal is electrically connected to the positive electrode sheet, and the negative output terminal is electrically connected to the negative electrode sheet. Specifically, the positive output terminal and the positive electrode sheet are electrically connected via an adapter sheet, and the negative output terminal and the negative electrode sheet are electrically connected via another adapter sheet. Between the output terminal and the top cover sheet, from the outside to the inside, are arranged an upper plastic, a sealing ring, and a lower plastic. The upper plastic is used to provide insulation or high resistance between the output terminal and the top cover sheet; the sealing ring is used to seal the edge of the output terminal and has insulation properties; the lower plastic assists the sealing ring in ensuring compression during press-fitting and has insulation properties.

[0045] The top cover assembly usually also includes an explosion-proof valve, which is set on the top cover piece. When the air pressure inside the battery cell reaches a certain value, the explosion-proof valve opens to discharge the gas inside the battery cell to ensure that no explosion occurs and to allow harmful gases to be discharged in a targeted manner.

[0046] However, when the strength of the top cover is insufficient, the top cover will deform during the use of the battery cell. The deformation of the top cover will cause the following problems: 1. The sealing between the top cover and the output terminal will deteriorate, and the electrochemical substances inside the shell will easily leak; 2. Since the deformation of the top cover will divert part of the pressure, the opening pressure of the explosion-proof valve will increase, and the explosion-proof valve will delay opening. When the valve opens, the pressure inside the battery cell has often exceeded the standard, which is prone to explosion, resulting in an increase in the danger level of the battery cell.

[0047] In view of this, the present application provides a top cover assembly of a battery cell and a battery cell to solve the problem that the existing battery cell top cover sheet is easy to deform, thereby improving the reliability and safety of the battery cell during use.

[0048] Figure 1 A schematic diagram of the exploded structure of a top cover assembly provided in one embodiment of the present application. Figure 2 This is a cross-sectional view of the top cover assembly in the exploded state. Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0049] like Figures 1 to 3 As shown, a top cover assembly 100 of a battery cell provided in the present application includes a top cover sheet 110 and a reinforcement block 120 . The top cover sheet 110 is provided with an assembly portion 111 , which is configured as a groove structure; the reinforcement block 120 is installed on the assembly portion 111 .

[0050] Figure 4 This is a schematic diagram of the exploded structure of a battery cell provided in one embodiment of the present application. Figure 4 The top cover piece 110 is configured to adapt to the shape of the battery cell's outer shell. For example, when the battery cell is a prismatic battery, the top cover piece 110 is rectangular and can cover the opening of the shell 200. Similarly, when the battery cell is a cylindrical battery, the top cover piece 110 is circular and can cover the opening of the shell 200. This embodiment of the application only takes the prismatic battery as an example to schematically illustrate the structure of the top cover assembly 100.

[0051] The top cover 110 is typically welded to the opening of the housing 200 around its perimeter. It also houses electrode terminals, an explosion-proof valve, and a liquid injection port. The specific structures of the explosion-proof valve and electrode terminals have been detailed above and will not be repeated here. The liquid injection port is used to inject electrolyte into the housing cavity. After the electrolyte is injected, the port is sealed.

[0052] The assembly portion 111 is a groove structure on the top cover piece 110. The groove structure refers to a structure that is concave relative to the flat surface of the top cover piece 110. The assembly portion 111 is set as a groove structure. After the reinforcement block 120 is installed in the assembly portion 111, the surface of the reinforcement block 120 can be kept basically flush with the surface of the top cover piece 110, or the height of the reinforcement block 120 protruding from the surface of the top cover piece 110 can be controlled within a certain range while ensuring that the reinforcement block 120 has sufficient strength, thereby reducing the maximum thickness of the top cover assembly 100 and thereby reducing the volume of the battery cell.

[0053] The assembly portion 111 can be located on the inside or outside of the top cover 110. The inside refers to the side closer to the inside of the battery cell's housing, while the outside refers to the side closer to the outside of the battery cell's housing. Accordingly, the reinforcement block 120 can also be located on the inside or outside of the top cover 110, providing greater flexibility in its configuration.

[0054] In addition, the number of assembly portions 111 can be one or more, and each assembly portion 111 can be located on the inside or outside of the top cover sheet 110 without being affected by the position of other assembly portions 111. Moreover, regardless of whether one or more assembly portions 111 are provided, the shape, size, and dimensions of each assembly portion 111 are not restricted, as long as they avoid the electrode terminals, liquid injection holes, and explosion-proof valves on the top cover sheet 110. One or more assembly portions 111 can be arranged according to the distribution of other components on the top cover sheet 110, making the location and number of the reinforcement blocks 120 more flexible, which is conducive to rationally configuring the number and location of the reinforcement blocks 120 without affecting the original structural characteristics of the top cover assembly 100, thereby enhancing the strength of the top cover assembly 100.

[0055] For example, in some embodiments, the assembly portion 111 is configured as a cubic groove, and the reinforcement block 120 is configured as a cube that matches the shape and size of the assembly portion 111 .

[0056] The reinforcement block 120 is a structure embedded in the assembly portion 111. The shape of the reinforcement block 120 is adapted to the shape of the assembly portion 111. In any direction, the size of the reinforcement block 120 can be slightly larger than the size of the assembly portion 111, slightly smaller than the size of the assembly portion 111, or equal to the size of the assembly portion 111.

[0057] After the reinforcement block 120 is embedded in the assembly portion 111, the reinforcement block 120 and the top cover piece 110 can be further fixed to make the connection between the reinforcement block 120 and the top cover piece 110 more firmly, thereby preventing the reinforcement block 120 from loosening or falling off when the battery cell is in use, thereby reducing the reinforcement effect of the top cover piece 110.

[0058] When the internal pressure of the battery cell increases, the top cover sheet 110 is subjected to a force from the inside out, which causes the top cover sheet 110 to bulge outward and deform. At this time, if the top cover sheet 110 wants to further undergo substantial deformation, it is necessary to overcome the pulling force or pushing force between the top cover sheet 110 and the reinforcement block 120 in multiple directions. Once the strength of the reinforcement block 120 is large, or the interaction force between the reinforcement block 120 and the inner wall of the assembly portion 111 is large, it is difficult for the top cover sheet 110 to undergo substantial deformation, thereby strengthening the top cover sheet 110.

[0059] It can be understood that the reinforcing effect of the reinforcement block 120 on the top cover sheet 110 has no direct relationship or significant difference to whether the reinforcement block 120 is arranged on the inner side or the outer side of the top cover sheet 110. As long as the reinforcement block 120 is arranged on the top cover sheet 110, the reinforcement block 120 can strengthen the strength of the top cover sheet 110 to a certain extent, reduce or even eliminate the deformation of the top cover sheet 110, and play a role in improving the reliability and safety of the battery cell during use.

[0060] Therefore, the top cover assembly 100 provided in the present application installs a reinforcement block 120 on the top cover sheet 110, so that the main part of the top cover assembly 100 is composed of the top cover sheet 110 and the reinforcement block 120. Compared with a single top cover sheet 110, once one side of the combined top cover assembly 100 is subjected to air pressure shock, in order to deform, the top cover sheet 110 and the reinforcement block 120 need to be deformed at the same time, and the relative stress between the top cover sheet 110 and the reinforcement block 120 needs to be overcome. Therefore, the deformation resistance of the top cover sheet 110 is increased, so that in cases of thermal runaway, the probability of airtight failure between the positive and negative output terminals and the top cover sheet 110 and delayed opening of the explosion-proof valve caused by the deformation of the top cover sheet 110 due to the internal pressure of the battery cell is reduced, thereby improving the reliability and safety of the battery cell during use.

[0061] The above analysis shows that the reinforcing effect of the reinforcement block 120 on the top cover sheet 110 is related to the interaction force between the reinforcement block 120 and the top cover sheet 110, as well as the material strength of the reinforcement block 120. The interaction force between the reinforcement block 120 and the top cover sheet 110 is related to the size of the reinforcement block 120 relative to the assembly portion 111, and is also related to the connection structure and connection method between the reinforcement block 120 and the assembly portion 111. Therefore, the present application proposes several implementation methods that can enhance the reinforcing effect of the reinforcement block 120 on the top cover sheet 110, as follows.

[0062] In a possible design, in any direction except the thickness of the reinforcement block 120 , the dimension M of the reinforcement block 120 and the dimension N of the assembly portion 111 satisfy: M≦N+0.2 mm (millimeter).

[0063] The dimension of a reinforcement block in a particular direction refers to the distance between two points on the edge of the reinforcement block along a line parallel to that direction. Depending on the shape of the reinforcement block and the position of the line, the dimensions corresponding to different locations on the reinforcement block may be the same or different, even in the same direction. For example, if the reinforcement block is a cubic block, the dimensions corresponding to different locations along the length of the cubic block are the same. However, if the reinforcement block is an elliptical sheet, the dimensions corresponding to different locations along the long axis of the ellipse are different.

[0064] The thickness direction of the reinforcing block 120 corresponds to the depth direction of the assembly portion 111 . The above embodiment does not limit the dimensions of the reinforcing block 120 and the assembly portion 111 in this direction.

[0065] Taking the reinforcing block 120 as a cubic block as an example, when the dimension N1 of the assembly portion 111 in the longitudinal direction of the reinforcing block 120 is 50 mm, the dimension M1 of the reinforcing block 120 in the longitudinal direction is ≤ 50.2 mm. When the dimension N2 of the assembly portion 111 in the width direction of the reinforcing block 120 is 20 mm, the dimension M2 of the reinforcing block 120 in the width direction is ≤ 20.2 mm.

[0066] Through the above solution, the size of the reinforcement block 120 in any direction is controlled to be within a range of 0.2 mm larger than the assembly portion 111, making it relatively easy to install the reinforcement block 120 into the assembly portion 111 without the possibility of failure to install.

[0067] In a possible design, the reinforcement block 120 is assembled to the assembly portion 111 of the top cover piece 110 by welding, screwing, or riveting.

[0068] Through the above solution, the reinforcement block 120 and the top cover piece 110 can be connected together by any of the above simpler methods, which reduces the difficulty of assembling the reinforcement block 120 and the top cover piece 110.

[0069] When the reinforcing block 120 is welded to the top cover sheet 110, either fusion welding or fill welding can be used, depending on the size of the reinforcing block 120. For example, when the size of the reinforcing block 120 is greater than or equal to the size of the assembly portion 111 in any direction other than the thickness of the reinforcing block 120, since the reinforcing block 120 and the assembly portion 111 fit tightly together, with no gap or a small gap between them, fusion welding can be used to fuse the edges of the reinforcing block 120 with the top cover sheet 110, thereby strengthening the connection. When the size of the reinforcing block 120 is smaller than the size of the assembly portion 111 in any direction other than the thickness of the reinforcing block 120, fill welding can be used to fill molten solder between the edges of the reinforcing block 120 and the assembly portion 111, thereby connecting the reinforcing block 120 and the top cover sheet 110 and filling and strengthening the connection position.

[0070] In a possible design, the material strength of the reinforcement block 120 is greater than or equal to the material strength of the top cover sheet 110 .

[0071] For example, if the top cover sheet 110 is made of 3-series aluminum, the reinforcement block 120 can be made of a higher-grade aluminum material, such as 6-series aluminum, 7-series aluminum, or 8-series aluminum. A higher aluminum grade indicates a higher aluminum content and, therefore, a higher strength.

[0072] Through the above solution, the strength of the reinforcement block 120 itself is relatively large. Therefore, the addition of the reinforcement block 120 will not lead to a decrease in the local strength of the top cover piece 110, and further will not reduce the local strength of the top cover assembly 100. In addition, when the top cover piece 110 is subjected to force, the reinforcement block 120 is not easy to deform, and thus can maintain good support for the top cover piece 110 for a long time, further making it more difficult for the top cover piece 110 to deform.

[0073] Regarding the assembly position of the reinforcement block 120, considering that the edge of the top cover sheet 110 is generally welded to the shell 200, the edge of the top cover sheet 110 is less likely to deform due to the traction of the shell 200, and the farther the top cover sheet 110 is from the edge, the easier it is to deform. That is to say, in any direction other than the thickness direction of the top cover sheet 110, the position where the top cover sheet 110 is most likely to deform is the center position of the top cover sheet 110 in that direction.

[0074] In view of this, if Figure 1 As shown, taking the top cover piece 110 as a cubic block as an example, in a possible design, the top cover piece 110 has a transverse center line 130, which is the center line that bisects the inner side or outer side of the top cover piece 110 along the width direction of the top cover piece 110; the assembly portion 111 is at least partially located on the transverse center line 130.

[0075] It can be understood that when the assembly portion 111 is located on the inner side of the top cover piece 110, the transverse center line 130 is the center line that bisects the inner side surface of the top cover piece 110 along the width direction of the top cover piece 110; when the assembly portion 111 is located on the outer side of the top cover piece 110, the transverse center line 130 is the center line that bisects the outer side surface of the top cover piece 110 along the width direction of the top cover piece 110.

[0076] In the width direction of the top cover sheet 110, the transverse centerline 130 is the most central position of the top cover sheet 110. The area where the transverse centerline 130 is located includes the area of ​​the top cover sheet 110 most susceptible to deformation. When the assembly portion 111 is at least partially located on the transverse centerline 130 and the reinforcement block 120 is located on the assembly portion 111, the area of ​​the top cover sheet 110 most susceptible to deformation is reinforced by the reinforcement block 120, making deformation more difficult, thereby enhancing the overall deformation resistance of the top cover sheet 110.

[0077] After ensuring the reinforcing effect of the reinforcing block 120 on the top cover sheet 110 , the aesthetics and volume of the top cover sheet 110 after adding the reinforcing block 120 must also be considered. Therefore, the thickness of the reinforcing block 120 can be less than or equal to the depth of the assembly portion 111 .

[0078] Through the above solution, after the reinforcement block 120 is installed in the assembly part 111, there will be no protrusion from the surface of the top cover piece 110, so there is no need to occupy additional space, the volume of the top cover assembly 100 is reduced, and the surface of the top cover piece 110 is relatively flat, thereby improving the aesthetics of the top cover piece 110.

[0079] Although the above embodiments are all described with the reinforcement block 120 being a cubic block as an example, it is understandable that the reinforcement block 120 can also be in various other shapes. Figure 5 A schematic diagram of the exploded structure of another top cover assembly provided in one embodiment of the present application. Figure 6 A schematic diagram of the exploded structure of another top cover assembly provided in one embodiment of the present application.

[0080] Please refer to Figure 5 and Figure 6 Taking the reinforcing block as a thin sheet as an example, when viewed from the inside or outside of the top cover assembly, the overall shape of the reinforcing block can be a rounded rectangle (as shown in FIG. Figure 5 As shown), "X" shape (as shown Figure 6 As shown), "Y" shape, "8" shape, diamond shape, snake shape, ellipse shape, etc., under the condition of meeting the requirements of the above embodiments, no matter what the shape of the reinforcement block 120 is, the top cover assembly 100 is within the scope of protection of this application.

[0081] The present application also provides a battery cell, such as Figure 4 As shown, it includes a shell 200, an electrode assembly 300 and a top cover assembly 100 in any of the above embodiments. The top cover assembly 100 is sealed around the opening of the shell 200, and the electrode assembly 300 is arranged in the space enclosed by the top cover assembly 100 and the shell 200.

[0082] The possible structures and beneficial effects of the shell 200, the electrode assembly 300 and the top cover assembly 100 have been described in detail above and will not be repeated here.

[0083] The battery cell using the top cover assembly 100 in any of the above embodiments is not prone to chemical leakage from the top cover assembly 100 during use, and the probability of delayed opening of the explosion-proof valve is small when thermal runaway occurs, thereby improving the reliability and safety of the battery cell.

[0084] The present application also provides a battery, comprising the battery cell in the above embodiment.

[0085] The above-mentioned battery can be a battery pack or a battery module. When the above-mentioned battery is a battery pack, the battery pack specifically includes a battery management system (BMS) and a plurality of the above-mentioned battery cells. The plurality of battery cells can be electrically connected in series, in parallel, or in a mixture of series and parallel, and communicated with the battery management system to form a battery pack, and the above-mentioned battery management system controls and monitors the working status of each battery cell. In addition, the plurality of battery cells can also be connected in series and / or in parallel first, and form a battery module with the module management system, and then the plurality of battery modules are electrically connected in series, in parallel, or in a mixture of series and parallel, and together with the battery management system form a battery pack.

[0086] The multiple cells in the battery pack or battery module can be mounted on a supporting structure such as a box, frame, or bracket. Electrical connections can be made between the cells and between the cells and the battery management system via busbars, such as tabs. The cells can be lithium-ion, sodium-ion, or magnesium-ion batteries, and their outer contours can be cylindrical, flat, rectangular, or other shapes, but are not limited thereto.

[0087] To sum up, the top cover assembly 100 provided in the embodiment of the present application installs a reinforcement block 120 on the top cover sheet 110, so that the main part of the top cover assembly 100 is composed of the top cover sheet 110 and the reinforcement block 120. Compared with a single top cover sheet 110, once one side of the combined top cover assembly 100 is subjected to air pressure shock, in order to deform, the top cover sheet 110 and the reinforcement block 120 need to be deformed at the same time, and the relative stress between the top cover sheet 110 and the reinforcement block 120 needs to be overcome. Therefore, the deformation resistance of the top cover sheet 110 is increased, so that in cases of thermal runaway, the probability of airtight failure between the positive and negative output terminals and the top cover sheet 110 and delayed opening of the explosion-proof valve caused by the deformation of the top cover sheet 110 due to the internal pressure of the battery cell is reduced, thereby improving the reliability and safety of the battery cell during use.

Claims

1. A top cover assembly of a battery cell, characterized in that: include: A top cover sheet, wherein the top cover sheet is provided with an assembly portion, and the assembly portion is configured as a groove structure; The reinforcement block is installed on the assembly portion.

2. The top cover assembly according to claim 1, wherein: The top cover sheet has a transverse centerline, which is a centerline bisecting the inner side or the outer side of the top cover sheet along the width direction of the top cover sheet; The mounting portion is at least partially located on the transverse centerline.

3. The top cover assembly according to claim 1, wherein: In any direction except the thickness of the reinforcement block, a dimension M of the reinforcement block and a dimension N of the assembly portion satisfy: M≤N+0.2 mm.

4. The top cover assembly according to claim 1, wherein: The thickness of the reinforcement block is less than or equal to the depth of the fitting portion.

5. The top cover assembly according to claim 1, wherein: The material strength of the reinforcement block is greater than or equal to the material strength of the top cover sheet.

6. The top cover assembly according to any one of claims 1 to 5, characterized in that: The number of the assembling parts is one or more, and correspondingly, the number of the reinforcing blocks is one or more.

7. The top cover assembly according to any one of claims 1 to 5, characterized in that: The assembly portion is provided on the inner side or the outer side of the top cover sheet, the inner side is the side close to the inner side of the shell of the battery core, and the outer side is the side close to the outer side of the shell of the battery core.

8. The top cover assembly according to any one of claims 1 to 5, characterized in that: The reinforcement block is assembled to the assembly portion of the top cover sheet by welding, screwing or riveting.

9. A battery cell, characterized in that: The invention comprises a shell, an electrode assembly and a top cover assembly according to any one of claims 1 to 8, wherein the top cover assembly is sealed to the circumference of the opening of the shell, and the electrode assembly is arranged in the space enclosed by the top cover assembly and the shell.

10. A battery, characterized in that: Including the battery cell according to claim 9.

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