Cover plate assembly and battery cell

Abstract

The application relates to the technical field of batteries, in particular to a cover plate assembly and a battery cell. The cover plate assembly comprises a cover plate body, an explosion-proof valve and a supporting ring. The cover plate body is provided with an explosion-proof hole penetrating through the cover plate body. The supporting ring and the explosion-proof valve are arranged on the two sides of the cover plate body in a first direction. The supporting ring comprises a ring body and a supporting leg. The ring body is arranged around the outside of the explosion-proof hole. The ring body and the cover plate body are spaced apart in the first direction, so as to form a buffer space between the ring body and the cover plate body. The supporting leg connects the ring body and the cover plate body. The number of the supporting legs is plural. The plural supporting legs are spaced apart along the outer edge of the ring body, so as to form an air inlet channel communicating with the buffer space between two adjacent supporting legs. The inner edge of the ring body surrounds to form an air inlet communicating with the buffer space. According to the cover plate assembly and the battery cell, the front end of the pole group is prevented from directly abutting against the cover plate body and plugging the explosion-proof hole, so that the pressure relief and exhaust efficiency of the explosion-proof valve are improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a cover plate assembly and a battery cell. Background Technology

[0002] The demand for large capacity and high safety performance in the energy storage cell field is increasing. In existing technologies, blade-type energy storage cells typically adopt a structure in which the terminals are led out on the same side and the explosion-proof valve is set on the opposite side cover plate to achieve thermal and electrical separation and improve the intrinsic safety performance of the cell.

[0003] However, when a thermal runaway accident occurs in a battery cell, the explosion-proof valve opens to release pressure and vent air, creating a rapid, high-temperature, and high-pressure airflow inside the cell. This airflow strongly impacts the internal electrode assembly, driving it towards the side where the explosion-proof valve is located. Once the electrode assembly moves, its front end can easily block the exhaust channel of the explosion-proof valve, obstructing airflow and significantly reducing the valve's pressure release and venting efficiency. Consequently, it cannot effectively curb the development of thermal runaway, severely weakening the overall safety assurance capability of the battery cell and hindering the application and promotion of blade energy storage cells in scenarios with high reliability requirements. Summary of the Invention

[0004] The purpose of this application is to provide a cover plate assembly and a battery cell to address, to some extent, the technical problem in the prior art where, during a thermal runaway accident in a battery cell, the explosion-proof valve opens to release pressure and vent air, creating a rapid, high-temperature, and high-pressure airflow inside the cell. This airflow strongly impacts the internal electrode assembly, driving it towards the side where the explosion-proof valve is located. Once the electrode assembly shifts, its front end can easily block the exhaust channel of the explosion-proof valve, obstructing airflow and significantly reducing the pressure relief and venting efficiency of the explosion-proof valve. Consequently, it fails to effectively curb the development of thermal runaway and severely weakens the overall safety assurance capability of the battery cell.

[0005] According to a first aspect of this application, a cover plate assembly is provided, the cover plate assembly having a first direction, a second direction and a third direction, wherein any two of the first direction, the second direction and the third direction are perpendicularly disposed; The cover plate assembly includes a cover plate body, an explosion-proof valve, and a support ring. The cover plate body is provided with an explosion-proof hole that penetrates itself. The support ring and the explosion-proof valve are respectively disposed on both sides of the cover plate body in the first direction. The support ring includes a ring body and a support leg. The ring body is arranged around the outside of the explosion-proof hole. The ring body and the cover plate body are spaced apart along the first direction to form a buffer space between the ring body and the cover plate body. The support leg connects the ring body and the cover plate body. The number of support legs is multiple, and the multiple support legs are spaced apart along the outer edge of the ring body to form an air intake channel connecting the buffer space between two adjacent support legs. The inner edge of the ring body surrounds an air intake port connecting the buffer space.

[0006] Preferably, the explosion-proof hole has a dimension of A1 in the second direction, and the air inlet has a dimension of A2 in the second direction, wherein 3mm ≤ ≤5mm; And / or, the dimension of the explosion-proof hole in the third direction is B1, and the dimension of the air inlet in the third direction is B2, wherein 3mm ≤ ≤5mm.

[0007] Preferably, the dimension of the cover plate body in the second direction is A0, and the dimension of the support ring in the second direction is A3, wherein 0.3 ≤ ≤0.4; And / or, the dimension of the cover plate body in the third direction is B0, and the dimension of the support ring in the third direction is B3, 5mm≤ ≤10mm.

[0008] Preferably, the dimension T1 of the cover plate body in the first direction satisfies: 2.0mm≤T1≤2.5mm; And / or, the wall thickness T2 of the support ring satisfies: 0.5mm≤T2≤0.8mm; And / or, the size of the explosion-proof hole in the second direction is A1, which satisfies: 40mm≤A1≤58mm; And / or, the size of the explosion-proof hole in the third direction, B1, satisfies: 20mm≤B1≤35mm.

[0009] Preferably, on the outer edge of the support ring, the total length of all the air intake channels accounts for 60% to 75% of the outer circumference of the support ring.

[0010] Preferably, it further includes a mounting platform, which is fixedly connected to the cover plate body, and the mounting platform is arranged along the edge of the explosion-proof hole to support the explosion-proof valve; The mounting platform is lowered a predetermined distance from the end face of the cover plate body on the side opposite to the support ring along the first direction toward the side closer to the support ring.

[0011] Preferably, the dimension T3 of the mounting platform in the first direction satisfies: 1.0mm ≤ T3 ≤ 1.2mm; And / or, the dimension B4 of the mounting platform in the normal direction of the explosion-proof hole satisfies: 1.2mm≤B4≤1.5mm.

[0012] Preferably, the cover plate body, the support ring, and the mounting platform are integrally stamped parts.

[0013] According to a second aspect of this application, a battery cell is provided, including the cover plate assembly described in any of the above technical solutions, and thus has all the beneficial technical effects of the cover plate assembly, which will not be repeated here.

[0014] It also includes an electrode assembly, an insulating support plate, and an adhesive part. The insulating support plate is disposed on the side where the support ring of the cover plate assembly is located, and the insulating support plate covers the side of the electrode assembly facing the cover plate assembly. The insulating support plate includes a partition portion and a limiting portion connected to each other. The limiting portion is disposed at both ends of the partition portion in the second direction, and the limiting portion is respectively disposed on both sides of the pole group in the second direction. The adhesive portion bonds the electrode assembly and the insulating support plate.

[0015] Preferably, in the second direction, the size of the pole group is L1, and the size of the partition is L2, wherein L2 < L1, and / or 1mm ≤ L1 - L2 ≤ 1.5mm; In the third direction, the size of the pole group is W1, and the size of the partition is W2, wherein W2 < W1, and / or, 1mm ≤ W1 - W2 ≤ 1.5mm; The total contact area between the insulating support plate and the electrode assembly is S1, and the total area of ​​the adhesive portion is S2, wherein 0.1 ≤ ≤0.15.

[0016] Compared with the prior art, the beneficial effects of this application are as follows: The cover plate assembly provided in this application has a support ring body surrounding the outside of the explosion-proof hole and spaced apart from the cover plate body along a first direction. When the thermal runaway of the battery cell generates a high-temperature and high-pressure airflow that impacts the electrode assembly and drives it to move towards the explosion-proof valve, the ring body can directly limit and block the front end of the electrode assembly, preventing the front end of the electrode assembly from directly contacting the cover plate body and blocking the explosion-proof hole. This solves the problem of the electrode assembly moving and blocking the exhaust channel, ensuring that the pressure relief and exhaust path of the explosion-proof valve remains unobstructed. The support ring connects the ring body and the cover plate body through multiple spaced legs. The air intake channel is formed between adjacent legs, and the air inlet is formed by the inner edge of the ring body. This allows the high-temperature and high-pressure airflow inside the battery cell to smoothly enter the buffer space between the ring body and the cover plate body through the air inlet and the air intake channel, and then quickly exit from the explosion-proof valve through the explosion-proof hole. This prevents the airflow from accumulating inside the battery cell and the pressure from rising disorderly, and greatly improves the pressure relief and exhaust efficiency of the explosion-proof valve. In addition, the buffer space formed between the ring body and the cover plate body can buffer and depressurize the high-temperature and high-pressure airflow, weakening the instantaneous impact of the airflow on the cover plate assembly and the electrode group. At the same time, the evenly distributed connection method of the support legs ensures the stability of the overall structure of the support ring, ensuring the continuous reliability of the limiting and guiding functions, and effectively improving the overall safety guarantee capability of the blade-type energy storage cell.

[0017] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is an exploded structural diagram of the cover plate assembly provided in an embodiment of this application; Figure 2 This is an isometric structural schematic diagram of the cover plate assembly provided in the embodiments of this application; Figure 3 A bottom view of the cover plate assembly provided in an embodiment of this application; Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure obtained by cutting the provided cover plate assembly along the CC direction; Figure 5 This is a front view of the cover plate assembly provided in an embodiment of this application; Figure 6 This is a schematic diagram of the exploded structure of a battery cell provided in an embodiment of this application; Figure 7 This is a schematic diagram of the exploded structure of the shell provided in an embodiment of this application; Figure 8 This is an isometric structural diagram of the insulating tray provided in an embodiment of this application.

[0020] Figure label: 1-Cover plate assembly; 10-Cover plate body; 101-Explosion-proof hole; 11-Support ring; 111-Ring body; 112-Support leg; 113-Air inlet channel; 114-Air inlet; 12-Setting platform; 13-Explosion-proof valve; 2-Pole group; 21-Layer section; 22-Insulating film section; 3-Insulating support plate; 31-Block section; 32-Limiting section; 33-Ventilation hole; 34-Adhesive section; 4-Pole post cover plate; 5-Housing shell.

[0021] F1 - First direction; F2 - Second direction; F3 - Third direction. Detailed Implementation

[0022] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0023] The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application.

[0024] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0025] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0027] The following reference Figures 1 to 8 This application describes a cover plate assembly 1 and a battery cell according to some embodiments.

[0028] See Figures 1 to 8 As shown, an embodiment of the first aspect of this application provides a cover plate assembly 1, which includes a cover plate body 10, an explosion-proof valve 13, and a support ring 11. The cover plate body 10 is provided with an explosion-proof hole 101 penetrating through itself. The support ring 11 and the explosion-proof valve 13 are respectively disposed on both sides of the cover plate body 10 in a first direction F1. The support ring 11 includes a ring body 111 and support legs 112. The ring body 111 is disposed around the outside of the explosion-proof hole 101. The ring body 111 and the cover plate body 10 are spaced apart along the first direction F1 to form a buffer space between the ring body 111 and the cover plate body 10. The support legs 112 connect the ring body 111 and the cover plate body 10. There are multiple support legs 112, which are spaced apart along the outer edge of the ring body 111 to form an air intake channel 113 communicating with the buffer space between two adjacent support legs 112. The inner edge of the ring body 111 surrounds an air inlet 114 communicating with the buffer space.

[0029] According to the above-mentioned technical features, the cover plate assembly 1 is arranged around the outside of the explosion-proof hole 101 by the ring body 111 of the support ring 11, and is distributed at intervals with the cover plate body 10 along the first direction F1. When the thermal runaway of the battery cell generates a high-temperature and high-pressure airflow that impacts the electrode group 2 and drives the electrode group 2 to move towards the explosion-proof valve 13, the ring body 111 can directly limit and block the front end of the electrode group 2, preventing the front end of the electrode group 2 from directly contacting the cover plate body 10 and blocking the explosion-proof hole 101. This solves the problem of the electrode group 2 moving and blocking the exhaust channel, and ensures that the pressure relief and exhaust path of the explosion-proof valve 13 remains unobstructed. The support ring 11 connects the ring body 111 and the cover plate body 10 via multiple spaced legs 112. An air intake channel 113 is formed between adjacent legs 112, and an air inlet 114 is formed around the inner edge of the ring body 111. This allows the high-temperature, high-pressure airflow inside the cell to smoothly enter the buffer space between the ring body 111 and the cover plate body 10 through the air inlet 114 and the air intake channel 113. The airflow then quickly exits through the explosion-proof hole 101 and exits through the explosion-proof valve 13, preventing airflow accumulation and disorderly pressure increases inside the cell, significantly improving the pressure relief and exhaust efficiency of the explosion-proof valve 13. Furthermore, the buffer space between the ring body 111 and the cover plate body 10 buffers and depressurizes the high-temperature, high-pressure airflow, reducing the instantaneous impact of the airflow on the cover plate assembly 1 and the electrode group 2. Simultaneously, the evenly distributed connection of the legs 112 ensures the overall structural stability of the support ring 11, guaranteeing the continuous reliability of the limiting and guiding functions, and effectively improving the overall safety of the blade-type energy storage cell.

[0030] The cover plate assembly 1 has a first direction F1, a second direction F2, and a third direction F3, wherein any two of the three directions F1, F2, and F3 are perpendicularly arranged. Figures 1 to 8 As shown in the figure, F1 can be an example of the first direction F1 described above, F2 can be an example of the second direction F2 described above, and F3 can be an example of the third direction F3 described above. Figure 6 and Figure 7 In the example of the square battery cell shown, the first direction F1 can be the length direction of the battery cell, the second direction F2 can be the width direction of the battery cell, and the third direction F3 can be the thickness direction of the battery cell.

[0031] Preferably, as shown in Table 1 and Figure 3 As shown, the size of the cover plate body 10 in the second direction F2 is A1, which satisfies 40mm≤A1≤58mm to accommodate most square cell sizes.

[0032] Preferably, as shown in Table 1 and Figure 3 As shown, the size of the cover plate body 10 in the third direction F3 is B1, which satisfies 20mm≤B1≤35mm to accommodate most square cell sizes.

[0033] Preferably, as shown in Table 1 and Figure 3 As shown, the dimension of the air intake 114 in the second direction F2 is A2, where 3mm ≤ The ≤5mm gap ensures that the air inlet 114 and the explosion-proof hole 101 form a suitable annular guide gap. This avoids the airflow from being obstructed when entering the buffer space due to an excessively small gap, while also preventing the support ring 11 from having insufficient strength due to an excessively large gap. This ensures that the high-temperature and high-pressure airflow can flow smoothly and evenly from the air inlet 114 into the buffer space and be discharged through the explosion-proof hole 101, further improving the stability of pressure relief and exhaust. On the other hand, this size parameter can accurately match the displacement of the electrode group 2. While effectively preventing the electrode group 2 from blocking the explosion-proof hole 101, it also avoids the support ring 11 occupying too much space inside the cell, thus balancing the energy density and safety performance of the cell.

[0034] Similarly, as shown in Table 1 and Figure 3 As shown, the dimension of the air intake 114 in the third direction F3 is B2, where 3mm ≤ ≤5mm, which is consistent with the above The beneficial effects of the range are similar and will not be repeated here.

[0035] Preferably, as shown in Table 1 and Figure 3 As shown, the dimension of the cover plate body 10 in the second direction F2 is A0, and the dimension of the support ring 11 in the second direction F2 is A3, wherein 0.3 ≤ ≤0.4, thus ensuring that the size of the support ring 11 is in a reasonable proportion to the cover plate body 10, and ensuring the support effect of the support ring 11 on the pole group 2 in the second direction F2.

[0036] Preferably, as shown in Table 1 and Figure 3 As shown, the dimension of the cover body 10 in the third direction F3 is B0, and the dimension of the support ring 11 in the third direction F3 is B3, 5mm≤ ≤10mm, thus ensuring the support strength at the narrowest point of the cover plate body 10.

[0037] Preferably, such as Figure 4 As shown, the dimension T1 of the cover plate body 10 in the first direction F1 satisfies: 2.0mm≤T1≤2.5mm, so as to balance the supporting strength of the cover plate body 10 and the energy density of the battery cell.

[0038] Preferably, such as Figure 4 As shown, the wall thickness T2 of the support ring 11 satisfies: 0.5mm≤T2≤0.8mm, thus balancing the support strength of the support ring 11 and the yield rate of the support ring 11.

[0039] Preferably, on the outer edge of the support ring 11, the total length of all intake channels 113 accounts for 60% to 75% of the outer circumference of the support ring 11; in other words, it is 0.60 ≤ 0.60 as shown in Table 1. With a value of ≤0.75, the support ring 11 can effectively balance support stability and intake efficiency.

[0040] In an embodiment, preferably, such as Figures 1 to 4 As shown, the cover plate assembly 1 may further include a mounting platform 12, which is fixedly connected to the cover plate body 10 and is disposed along the edge of the explosion-proof hole 101 to support the explosion-proof valve 13. This facilitates the overlap between the explosion-proof valve 13 and the cover plate body 10; furthermore, by using the height difference between the mounting platform 12 and the cover plate body 10 in the first direction F1 to set the explosion-proof valve 13, the dimensions of the cover plate assembly 1 in the first direction F1 are effectively reduced, thereby increasing the volumetric energy density of the battery cell.

[0041] Preferably, such as Figure 1 and Figure 2 As shown, the mounting platform 12 is lowered a predetermined distance from the end face of the cover plate body 10 on the side opposite to the support ring 11 along the first direction F1 towards the side closer to the support ring 11. In this way, the explosion-proof valve 13 and the support protrusion are respectively arranged on both sides of the cover plate body 10 in the first direction F1. This not only facilitates the assembly of the explosion-proof valve 13, but also effectively avoids interference between the support ring 11 and the explosion-proof valve 13, thus preventing the explosion-proof valve 13 from opening normally.

[0042] Preferably, such as Figure 1 and Figure 4 As shown, the dimension T3 of the mounting platform 12 in the first direction F1 satisfies: 1.0mm≤T3≤1.2mm, thus balancing the support strength of the mounting platform 12 and the energy density of the battery cell.

[0043] Preferably, such as Figure 1 As shown, the dimension B4 of the mounting platform 12 in the normal direction of the explosion-proof hole 101 satisfies: 1.2mm ≤ B4 ≤ 1.5mm, thus ensuring the stability of the mounting platform 12 in supporting the explosion-proof valve 13. It should be noted that the normal direction of the explosion-proof hole 101 can be understood as the direction perpendicular to the tangent plane of any point on the wall of the explosion-proof hole 101.

[0044] Preferably, the cover plate body 10, the support ring 11, and the mounting platform 12 can be integrally stamped parts. This ensures the connection strength of the cover plate body 10, the support ring 11, and the mounting platform 12, and also ensures the machining accuracy of the cover plate body 10, the support ring 11, and the mounting platform 12, simplifying the assembly process of the cover plate assembly 1.

[0045] For ease of description, the two opposite sides of the cover plate body 10 in the first direction F1 are defined as the first side and the second side, respectively, where the first side is the side where the support ring 11 is located. Specifically, during the processing, the mounting platform 12 can be punched out from the corresponding position of the original sheet material of the cover plate body 10 along the direction from the second side to the first side using a stamping process. An explosion-proof hole 101 is punched out in the middle of the mounting platform 12 according to the size of the explosion-proof hole 101. At this time, the excess sheet material originally located at the explosion-proof hole 101 will extend towards the first side along the perimeter of the explosion-proof hole under the stamping action. Then, a mold is used on the portion of the excess sheet material exceeding the thickness of the mounting platform 12, and this portion of the excess sheet material is expanded outward to the position of the support leg 112 by extrusion. Finally, it is shaped according to the shape of the support ring 11 using a roll forming process to achieve the integrated stamping processing of the cover plate body 10, the support ring 11, and the mounting platform 12. It should be noted that the above processing technology is existing in the field and will not be described in detail here.

[0046] Table 1:

[0047] See Figures 6 to 8 The second aspect of this application also provides a battery cell including the cover plate assembly 1 described in any of the above embodiments, and thus has all the beneficial technical effects of the cover plate assembly 1, which will not be repeated here.

[0048] Preferably, such as Figure 6 and Figure 7 As shown, the aforementioned battery cell may further include an electrode assembly 2. Optionally, not shown in the figure, the electrode assembly 2 may include a stacked portion 21 and an insulating film portion 22. The stacked portion 21 is formed by alternating stacking of positive and negative electrode sheets, and the insulating film portion 22 covers the outside of the stacked portion 21 to achieve insulation of the electrode assembly 2. It should be noted that the aforementioned electrode assembly 2 structure is a prior art structure and will not be described in detail here.

[0049] Preferably, such as Figure 6 and Figure 7 As shown, the aforementioned battery cell also includes an insulating support plate 3, which is disposed on the side of the support ring 11 of the cover plate assembly 1. The insulating support plate 3 covers the side of the electrode group 2 facing the cover plate assembly 1 to achieve insulation between the cover plate assembly 1 and the electrode group 2. In this way, the traditional lower plastic structure of the cover plate is eliminated, which not only better accommodates the structure of the support ring 11, but also effectively saves the space occupied by the insulating components between the cover plate assembly 1 and the battery cell, further reducing the impact of the support ring 11 on the volumetric energy density of the battery cell.

[0050] Preferably, the insulating plate 3 can be made of insulating material and is in sheet form. The insulating plate 3 can cover the end of the pole group 2 facing the cover plate assembly 1.

[0051] Optionally, the material of the insulating tray 3 can meet the following requirements: tensile strength ≥ 50 MPa, elastic modulus E ≥ 1100 MPa, and elongation A ≥ 85%, so as to ensure the durability of the insulating tray 3 and the limiting energy for the following electrode group 2.

[0052] Preferably, such as Figure 8 As shown, the wall thickness of the above-mentioned insulating tray 3 can be expressed as t, where 0.5mm≤t≤1mm, in order to balance the insulation and economy of the insulating tray 3.

[0053] Preferably, such as Figures 6 to 8 As shown, the insulating tray 3 may include a partition body and an adhesive part 34. The adhesive part 34 is disposed on the side of the partition body facing the electrode assembly 2, and is used to bond the electrode assembly 2 to the partition body, thereby fixing the insulating tray 3 to the electrode assembly 2. Optionally, the insulating tray 3 can be attached to the outside of the insulating film part 22 via the adhesive part 34.

[0054] Optionally, the adhesive portion 34 can be an insulating adhesive, which on the one hand ensures the durability and high-temperature resistance of the adhesive portion 34 in the electrolyte environment; on the other hand, it further improves the insulation between the electrode assembly 2 and the cover plate assembly 1. Optionally, the temperature resistance range of the adhesive portion 34 is between -40℃ and 85℃, and the adhesive portion 34 also needs to meet the following requirements: peel force N > 35N at 180℃, and remain unfallen for more than 60 hours. Initial tack force > 25N, thus ensuring the bonding effect of the insulating tray 3.

[0055] Preferably, such as Figure 6 and Figure 8 As shown, the partition body may include a partition part 31 and a limiting part 32 connected to each other. The limiting part 32 is connected to both sides of the partition part 31 in the second direction F2. The limiting part 32 is disposed on the side of the pole group 2 in the second direction F2, thus ensuring the complete coverage of the pole group 2 by the insulating support plate 3.

[0056] Preferably, the total contact area of ​​the insulating tray 3 and the electrode assembly 2 is S1, and the area of ​​the adhesive portion 34 is S2, wherein 0.1 ≤ ≤0.15, thus, ≥0.1 can effectively ensure the bonding stability of the insulating tray 3 and prevent the insulating tray 3 from falling off and moving relative to the pole group 2. With a value of ≤0.15, the usable area of ​​the adhesive part 34 can be effectively saved, reducing the space occupied by the adhesive part 34 and the adhesive cost.

[0057] Preferably, such as Figure 6As shown, the partition body is also provided with a vent 33 that penetrates itself along the first direction F1, so as to guide the gas inside the electrode group 2 to the cover plate assembly 1.

[0058] Preferably, the aperture of the above-mentioned vent 33 can be expressed as φ, where 4mm≤φ≤6mm. In this way, particulate impurities in the electrode group 2 can be effectively prevented from falling into the housing 5, thus ensuring the insulation of the housing 5.

[0059] Preferably, the insulating tray 3 is projected along the first direction F1 onto a plane perpendicular to the first direction F1, so that the total projected area of ​​all the vent holes 33 can account for 3% to 6% of the projected area of ​​the insulating tray 3, so as to take into account the supporting strength, insulation and exhaust efficiency of the insulating tray 3.

[0060] Preferably, such as Figure 6 As shown, the end of the electrode group 2 facing the cover plate assembly 1 is provided with a clearance groove, which is provided in correspondence with the support ring 11. In this way, the impact of the support ring 11 on the volumetric energy density of the battery cell is further reduced.

[0061] Correspondingly, as shown in 6, the position of the partition 31 corresponding to the clearance groove is also provided with a clearance groove. In other words, the insulating support plate 3 is configured to conform to the end of the pole group 2 near the cover plate assembly 1.

[0062] Optionally, such as Figure 7 As shown, the aforementioned battery cell may further include a housing 5 and a terminal cover plate 4. The cover plate assembly 1 and the terminal cover plate 4 can be respectively disposed opposite to each other on both sides of the housing 5 in the first direction F1 to form a closed space for accommodating the aforementioned electrode group 2. It should be noted that the aforementioned terminal cover plate 4 can be understood as a cover plate on the terminal setting side of the battery cell. The terminal cover plate 4 is a prior art structure and will not be described in detail here.

[0063] Preferably, such as Figure 6 As shown, in the second direction F2, the size of the pole group 2 can be represented as L1, and the size of the insulating support plate 3 can be represented as L2, where 1mm≤L1-L2≤1.5mm. That is to say, the insulating support plate 3 is interference-fitted with the pole group 2. In this way, the insulating support plate 3 can constrain the end of the pole group 2 near the cover plate assembly 1, thereby facilitating the smooth installation of the pole group 2 into the housing 5.

[0064] Preferably, such as Figure 6 As shown, on the third direction F3, the size of the pole group 2 can be represented as W1, and the size of the insulating support plate 3 can be represented as W2, where 1mm≤W1-W2≤2mm, so as to avoid interference between the insulating support plate 3 and the housing 5 during the process of the pole group 2 being inserted into the housing.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A cover plate assembly, characterized in that, The cover plate assembly has a first direction, a second direction, and a third direction, wherein any two of the first direction, the second direction, and the third direction are perpendicularly arranged. The cover plate assembly includes a cover plate body, an explosion-proof valve, and a support ring. The cover plate body is provided with an explosion-proof hole that penetrates itself. The support ring and the explosion-proof valve are respectively disposed on both sides of the cover plate body in the first direction. The support ring includes a ring body and a support leg. The ring body is arranged around the outside of the explosion-proof hole. The ring body and the cover plate body are spaced apart along the first direction to form a buffer space between the ring body and the cover plate body. The support leg connects the ring body and the cover plate body. The number of support legs is multiple, and the multiple support legs are spaced apart along the outer edge of the ring body to form an air intake channel connecting the buffer space between two adjacent support legs. The inner edge of the ring body surrounds an air intake port connecting the buffer space.

2. The cover plate assembly according to claim 1, characterized in that, The explosion-proof hole has a dimension of A1 in the second direction, and the air inlet has a dimension of A2 in the second direction, wherein 3mm ≤ ≤5mm; And / or, the dimension of the explosion-proof hole in the third direction is B1, and the dimension of the air inlet in the third direction is B2, wherein 3mm ≤ ≤5mm.

3. The cover plate assembly according to claim 1, characterized in that, The dimension of the cover plate body in the second direction is A0, and the dimension of the support ring in the second direction is A3, wherein 0.3 ≤ ≤0.4; And / or, the dimension of the cover plate body in the third direction is B0, and the dimension of the support ring in the third direction is B3, 5mm≤ ≤10mm.

4. The cover plate assembly according to claim 1, characterized in that, The dimension T1 of the cover plate body in the first direction satisfies: 2.0mm≤T1≤2.5mm; And / or, the wall thickness T2 of the support ring satisfies: 0.5mm≤T2≤0.8mm; And / or, the size of the explosion-proof hole in the second direction is A1, which satisfies: 40mm≤A1≤58mm; And / or, the size of the explosion-proof hole in the third direction, B1, satisfies: 20mm≤B1≤35mm.

5. The cover plate assembly according to claim 1, characterized in that, On the outer edge of the support ring, the total length of all the air intake channels accounts for 60% to 75% of the outer circumference of the support ring.

6. The cover plate assembly according to any one of claims 1 to 5, characterized in that, It also includes a mounting platform, which is fixedly connected to the cover plate body and is arranged along the edge of the explosion-proof hole to support the explosion-proof valve; The mounting platform is lowered a predetermined distance from the end face of the cover plate body on the side opposite to the support ring along the first direction toward the side closer to the support ring.

7. The cover plate assembly according to claim 6, characterized in that, The dimension T3 of the mounting platform in the first direction satisfies: 1.0mm ≤ T3 ≤ 1.2mm; And / or, the dimension B4 of the mounting platform in the normal direction of the explosion-proof hole satisfies: 1.2mm≤B4≤1.5mm.

8. The cover plate assembly according to claim 6, characterized in that, The cover plate body, the support ring, and the mounting platform are all integral stamped parts.

9. A battery cell, characterized in that, Includes the cover plate assembly according to any one of claims 1 to 8; It also includes an electrode assembly, an insulating support plate, and an adhesive part. The insulating support plate is disposed on the side where the support ring of the cover plate assembly is located, and the insulating support plate covers the side of the electrode assembly facing the cover plate assembly. The insulating support plate includes a partition portion and a limiting portion connected to each other. The limiting portion is disposed at both ends of the partition portion in the second direction, and the limiting portion is respectively disposed on both sides of the pole group in the second direction. The adhesive portion bonds the electrode assembly and the insulating support plate.

10. The battery cell according to claim 9, characterized in that, In the second direction, the size of the pole group is L1, and the size of the partition is L2, wherein L2 < L1, and / or 1mm ≤ L1 - L2 ≤ 1.5mm; In the third direction, the size of the pole group is W1, and the size of the partition is W2, wherein W2 < W1, and / or, 1mm ≤ W1 - W2 ≤ 1.5mm; The total contact area between the insulating support plate and the electrode assembly is S1, and the total area of ​​the adhesive portion is S2, wherein 0.1 ≤ ≤0.15.

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