Cover plate assembly and battery cell

Abstract

The application provides a cover plate assembly and a battery cell, and relates to the technical field of batteries. The cover plate assembly comprises an explosion-proof valve, a cover plate body and a plurality of support frames. The cover plate body is provided with a mounting opening, and the explosion-proof valve is arranged in the mounting opening. The plurality of support frames are arranged at intervals along a second direction. The support frame comprises a support plate and two fixing members. The two fixing members are respectively connected to both ends of the support plate in a third direction. The fixing members protrude towards the cover plate body relative to the support plate. The two fixing members are respectively connected to the cover plate body. The two fixing members are located on both sides of the explosion-proof valve in the third direction. The support plate and the explosion-proof valve are arranged at intervals along a first direction. When the battery cell is in thermal runaway, the plurality of support frames can support the pole group, so as to form an exhaust passage between the pole group and the explosion-proof valve. High-temperature gas can flow to the explosion-proof valve through the exhaust passage, and then be discharged through the explosion-proof valve. In this way, the exhaust effect of the explosion-proof valve is ensured, and the safety performance of the battery cell is 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] Lithium-ion batteries are widely used in various fields such as transportation power supply, power storage, new energy storage power supply, aerospace and military industries due to their advantages such as large capacity, high operating voltage, strong charge retention capability, and long cycle life. A typical energy storage cell includes a cover plate, casing, bare cell, insulating film, side plates, electrode assembly, and electrolyte.

[0003] Energy storage cells generally have a large capacity and higher safety requirements. Their positive and negative terminals can be set on the same cover plate, and the explosion-proof valve is set on the opposite cover plate to achieve thermal and electrical separation and improve the safety performance of the cell.

[0004] However, when thermal runaway occurs in the battery cell, the explosion-proof valve opens to release pressure and exhaust gas. As the pressure decreases, the electrode assembly will move towards the explosion-proof valve under the impact of the high-temperature and high-pressure airflow inside the battery cell. This causes the front end of the electrode assembly to block the explosion-proof valve, which will significantly reduce the exhaust effect of the explosion-proof valve and thus weaken the safety performance of the battery cell. Summary of the Invention

[0005] In view of this, this application provides a cover plate assembly and a battery cell to solve, to some extent, the problem that electrode movement during battery cell thermal runaway can block the explosion-proof valve.

[0006] According to one aspect of this application, a cover plate assembly is provided, the cover plate assembly including an explosion-proof valve, a cover plate body and a plurality of support frames, the cover plate body having an installation port extending through the cover plate body in a first direction, and the explosion-proof valve being disposed in the installation port; Multiple support frames are arranged at intervals along a second direction. Each support frame includes a support plate and two fixing members. The two fixing members are respectively connected to both ends of the support plate in a third direction. The fixing members protrude relative to the support plate toward the cover plate body. The two fixing members are respectively connected to the cover plate body. The two fixing members are located on both sides of the explosion-proof valve in the third direction. The support plate and the explosion-proof valve are arranged at intervals along a first direction. The first direction is perpendicular to the second direction. The third direction is perpendicular to the plane defined by the first direction and the second direction.

[0007] Preferably, the dimension of the explosion-proof valve in the second direction is The dimension of the support frame in the second direction is The number of the support frames is , , and ,satisfy: .

[0008] Preferably, the fastener includes a fixing part and a connecting part. The two ends of the connecting part in the first direction are respectively connected to the fixing part and the support plate. The fixing part extends away from the support plate relative to the connecting part. The fixing part is connected to the cover plate body.

[0009] Preferably, a portion of the support plate protrudes along the side away from the cover plate body in the first direction to form a reinforcing rib; The support plate has a plurality of reinforcing ribs, which are spaced apart along the third direction.

[0010] Preferably, the thickness of the support frame is The distance between the two fixing parts in the third direction is , and satisfy: .

[0011] Preferably, a plane perpendicular to the first direction is defined as the projection plane, and the sum of the areas of the projections of the plurality of reinforcing ribs along the first direction onto the projection plane is... The area of ​​the projection of the support plate onto the projection plane along the first direction is , and satisfy: .

[0012] Preferably, the dimension of the explosion-proof valve in the second direction is , and satisfy: .

[0013] According to another aspect of this application, a battery cell is provided, the battery cell including an electrode assembly and the aforementioned cover plate assembly, the electrode assembly including a contact surface and a clearance groove, the clearance groove being recessed from the contact surface toward the interior of the electrode assembly, and the support frame being located within the clearance groove.

[0014] Preferably, the battery cell further includes a support plate, the support plate including an insulating body and two extensions, the two extensions being connected to opposite ends of the insulating body, the insulating body covering the contact surface and the groove wall of the clearance groove, and the two extensions being abutted to opposite ends of the electrode assembly.

[0015] Preferably, the dimension of the electrode assembly in the second direction is When the support plate is not mounted on the electrode assembly, the dimension of the support plate in the second direction is: , and satisfy: .

[0016] The cover assembly of this application includes an explosion-proof valve, a cover body, and multiple support frames. The cover body has an installation port extending through it in a first direction, and the explosion-proof valve is disposed within the installation port. The multiple support frames are spaced apart in a second direction. Each support frame includes a support plate and two fixing members. The two fixing members are respectively connected to the two ends of the support plate in a third direction. The fixing members protrude relative to the support plate towards the cover body and are located on either side of the explosion-proof valve in the third direction. The support plate and the explosion-proof valve are spaced apart in the first direction. In the event of thermal runaway in the battery cell, the multiple support frames can support the electrode assembly, forming an exhaust channel between the electrode assembly and the explosion-proof valve. High-temperature gas can flow through the exhaust channel to the explosion-proof valve and then be discharged through the explosion-proof valve. This ensures the exhaust effect of the explosion-proof valve and improves the safety performance of the battery cell. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A three-dimensional structural schematic diagram of the cover plate assembly is shown; Figure 2 A schematic diagram of the planar structure of the cover plate assembly from one perspective is shown; Figure 3 A schematic diagram of the cover plate assembly from another perspective is shown. Figure 4 This shows a planar structural schematic diagram of the cover plate assembly from another perspective; Figure 5 A three-dimensional structural diagram of the support frame is shown; Figure 6 A schematic diagram of the planar structure of the support frame is shown; Figure 7 A schematic diagram of the planar structure of the cover plate body is shown; Figure 8 A three-dimensional structural diagram of the battery cell is shown; Figure 9 A partial structural diagram of the battery cell is shown; Figure 10 A diagram showing the relative positions of the support plate, electrode assembly, and insulating film; Figure 11 A three-dimensional structural diagram of the tray is shown; Figure 12 A schematic diagram of the planar structure of the tray is shown.

[0019] Reference numerals: 1-Explosion-proof valve; 2-Cover plate body; 3-Support plate; 31-Insulating body; 311-Fitting part; 312-Extension part; 32-Extension piece; 33-Vent hole; 34-Installation groove; 4-Adhesive layer; 5-Electrode assembly; 51-Electrode group; 52-Insulating film; 521-Vent hole; 53-Allowing groove; 54-Contact surface; 6-Support frame; 61-Support plate; 611-Reinforcing rib; 62-Fixing piece; 621-Fixing part; 622-Connecting part; 7-Shell; 8-Top cover; F1-First direction; F2-Second direction; F3-Third direction. Detailed Implementation

[0020] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein; changes that will be apparent after understanding the disclosure of this application are possible, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.

[0021] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0022] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly on" another element, or "directly covering" another element, there may be no other elements in between.

[0023] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0024] Although terms such as “first,” “second,” and “third” may be used herein to describe individual components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the examples described herein, the first component, assembly, region, layer, or part referred to as the second component, assembly, region, layer, or part may also be referred to as the second component, assembly, region, layer, or part.

[0025] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” are used herein to describe the relationship between one element and another, as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to that other element. Therefore, the term “above” includes both “above” and “below” orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relation terms used herein will be interpreted accordingly.

[0026] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0027] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0028] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.

[0029] The following will combine Figures 1 to 12The cover plate assembly and the battery cell are described. Figures 1 to 12 In the middle, the first direction F1 is perpendicular to the second direction F2, and the third direction F3 is perpendicular to the plane determined by the second direction F2 and the first direction F1.

[0030] According to one aspect of this application, a cover plate assembly is provided, such as... Figures 1 to 7 As shown, the cover assembly includes an explosion-proof valve 1, a cover body 2, and multiple support frames 6. The cover body 2 has an installation port extending through it along a first direction F1, and the explosion-proof valve 1 is installed in the installation port. Multiple support frames 6 are spaced apart along a second direction F2. Each support frame 6 includes a support plate 61 and two fixing members 62. The two fixing members 62 are respectively connected to both ends of the support plate 61 in a third direction F3. The fixing members 62 protrude relative to the support plate 61 towards the cover body 2. The two fixing members 62 are located on both sides of the explosion-proof valve 1 in the third direction F3. The support plate 61 and the explosion-proof valve 1 are spaced apart along the first direction F1. In the event of thermal runaway of the battery cell, the multiple support frames 6 can support the electrode assembly 51, forming an exhaust channel between the electrode assembly 51 and the explosion-proof valve 1. High-temperature gas can flow through the exhaust channel between the electrode assembly 51 and the explosion-proof valve 1 to the explosion-proof valve 1, and then be discharged through the explosion-proof valve 1. In this way, when the cell experiences thermal runaway, the electrode group 51 will not block the explosion-proof valve 1, ensuring the venting effect of the explosion-proof valve 1 and improving the safety performance of the cell.

[0031] In the embodiments of this application, such as Figure 4 , Figure 5 and Figure 6 As shown, the fixing member 62 includes a fixing part 621 and a connecting part 622. The two ends of the connecting part 622 in the first direction F1 are connected to the fixing part 621 and the support plate 61, respectively. The fixing part 621 extends away from the support plate 61 relative to the connecting part 622. The fixing part 621 is welded to the cover plate body 2, thereby fixing the support frame 6. In this way, by setting the fixing member 62 including the fixing part 621 and the connecting part 622, the support plate 61 and the explosion-proof valve 1 are arranged at intervals along the first direction F1, so that the support plate 61 can support the electrode assembly 51 in the event of thermal runaway, thereby preventing the electrode assembly 51 from blocking the explosion-proof valve 1.

[0032] Furthermore, a portion of the support plate 61 protrudes along the first direction F1 away from the cover plate body 2 to form a reinforcing rib 611. Multiple reinforcing ribs 611 are formed on the support plate 61, and these ribs are spaced apart along the third direction F3. Thus, by processing reinforcing ribs 611 on the support plate 61, the structural strength of the support plate 61 can be improved, thereby enhancing the support effect of the support frame 6 on the pole assembly 51.

[0033] Optionally, the thickness of the support frame 6 is , satisfy: The dimension of the reinforcing rib 611 in the first direction F1 is... , satisfy: .

[0034] Furthermore, the dimension of the support frame 6 in the first direction F1 is , satisfy: .

[0035] Furthermore, such as Figure 7 As shown, the dimension of explosion-proof valve 1 in the second direction F2 is... The dimension of explosion-proof valve 1 in the second direction F2 is , and satisfy: , .

[0036] like Figure 2 and Figure 4 As shown, the dimension of the support frame 6 in the second direction F2 is That is, the dimensions of the support plate 61, the fixing part 621, and the connecting part 622 in the second direction F2 are all The distance between the two fixed parts 621 is That is, the dimension of the suspended part of the support frame 6 in the second direction F2 is The dimensions of the support plate 61 on the third direction F3 are: .

[0037] Optionally, a plane perpendicular to the first direction F1 is defined as the projection plane, and the sum of the areas of the projections of the multiple reinforcing ribs 611 along the first direction F1 onto the projection plane is... The area of ​​the support plate 61 projected onto the projection plane along the first direction F1 is... ,in, . and satisfy: In this way, the area occupied by the reinforcing rib 611 can be limited to ensure the structural strength of the support frame 6.

[0038] In the embodiments of this application, the number of support frames 6 is: , , and ,satisfy: .exist At that time, the dimensions of the multiple support frames 6 in the second direction F2 are relatively small, resulting in poor support effect of the multiple support frames 6 on the pole group 51, and the support frames 6 are at risk of deformation; At that time, the dimensions of the multiple support frames 6 in the second direction F2 are relatively large, and the area of ​​the multiple exhaust channels formed by the multiple support frames 6 is relatively small. This results in low exhaust efficiency during thermal runaway, affecting the safety performance of the battery cell. At the same time, it can ensure the support effect of the support frame 6 while ensuring the exhaust efficiency during thermal runaway.

[0039] Optionally, the number of support frames 6 It can be equal to 2, 3, 4, or 5. Preferably, ,at this time, and satisfy: .

[0040] Furthermore, and satisfy: .exist At that time, the dimension of the support plate 61 in the first direction F1 The larger size of the support plate 61 reduces the space available for the electrode assembly 51, thus affecting the cell's capacity. The distance between the two fixed parts 621 The support frame 6 is too large, posing a significant risk of deformation under pressure. Furthermore, the support frame 6 lacks sufficient strength to stably support the pole assembly 51. At the same time, it is possible to balance the structural strength of the support frame 6 and the capacity of the battery cell.

[0041] also, and satisfy: This is to facilitate welding the support frame 6 onto the cover plate body 2.

[0042] Alternatively, the entire support frame 6 can be made of aluminum.

[0043] Select rated discharge energy for Rated charging power for Rated voltage for Ten groups of battery cells were subjected to thermal runaway performance tests. The parameters of the ten cells in each group were identical, while the parameters of the cells in different groups were different. , , , , , , and The values ​​are shown in the table below.

[0044] Test environment: The battery cell under test is placed in the thermal runaway test apparatus. A sheet-like heating element is arranged on the largest surface area of ​​the battery cell. The size of the sheet-like heating element is no larger than the area of ​​the largest surface area of ​​the battery cell, and the power of the heating element needs to be greater than [missing information]. (For example, the power of the heating element can be) ); Test equipment: A temperature sensor with a diameter of less than 1 mm is placed at the center of the other surface with the largest area in the battery cell. The temperature sampling period is set to 1 second, and the test is set to continuously detect three temperature rise rate values ​​that are greater than or equal to... Alternatively, fire or explosion can be used as the criteria for determining thermal runaway. The test cell is then connected to the charging and discharging device and its voltage data sampling line. Experimental method: Perform constant current charging, start heating, and record time, voltage, current, temperature, and rate of temperature rise. Record experimental phenomena, including expansion, leakage, smoke, fire, explosion, shell rupture, and rupture location; trigger the judgment condition for thermal runaway or when the temperature reaches... Or the test time reaches When the power is turned off and heating is stopped, observe for 1 hour and record the time, voltage, current, temperature, and rate of temperature rise. Record the test phenomena, including expansion, leakage, smoke, fire, explosion, shell cracking, crack location, electrode group 51 movement, and support frame 6 deformation.

[0045] The test results of 10 groups of battery cells are as follows:

[0046] Based on the table above, it can be seen that... At that time, the span of the suspended portion of support frame 6 was too large, making support frame 6 prone to deformation under pressure and insufficient strength. The width of multiple support frames 6 is insufficient, resulting in poor support and deformation. ,and At the same time, it can ensure the supporting effect of multiple support frames 6 on pole group 51. In the event of thermal runaway, explosion-proof valve 1 can open normally, pole group 51 will not move significantly, and support frame 6 will not deform, and its strength meets the requirements.

[0047] According to another aspect of this application, a battery cell is provided, such as... Figures 8 to 12 As shown, the battery cell includes an electrode assembly 5 and the aforementioned cover plate assembly. The electrode assembly 5 includes a contact surface 54 and a clearance groove 53. The clearance groove 53 is recessed from the contact surface 54 toward the interior of the electrode assembly 5, and the support frame 6 is located within the clearance groove 53.

[0048] Preferably, the first direction F1 is parallel to the length direction of the battery cell, the second direction F2 is parallel to the width direction of the battery cell, and the third direction F3 is parallel to the thickness direction of the battery cell.

[0049] like Figure 8 As shown, the battery cell also includes a housing 7 and a top cover 8. The electrode assembly 5 is disposed inside the housing 7. The two ends of the housing 7 in the first direction F1 are welded to the top cover 8 and the cover plate body 2, respectively.

[0050] like Figure 9 and Figure 10 As shown, the battery cell also includes a support plate 3, which includes an insulating body 31 and two extensions 32. The two extensions 32 are respectively connected to both ends of the insulating body 31 in the second direction F2. The insulating body 31 has multiple vent holes 33. The insulating body 31 is attached to the side of the electrode assembly 5 facing the cover plate assembly in the first direction F1. The two extensions 32 are respectively attached to both sides of the electrode assembly 5 in the second direction F2. The electrode assembly 5 and the support plate 3 are interference-fitted. The support plate 3 can achieve insulation between the electrode assembly 5 and the support frame 6, and between the electrode assembly 5 and the cover plate body 2. When the battery cell experiences thermal runaway and the support plate 3 does not melt, the explosion-proof valve 1 opens, and high-temperature gas can flow out from the vent holes 33. Then, it flows to the explosion-proof valve 1 through the exhaust channel between the electrode assembly 51 and the explosion-proof valve 1, and is then discharged through the explosion-proof valve 1. When thermal runaway occurs in the battery cell and the support plate 3 melts, the support frame 6 can support the electrode assembly 5. High-temperature gas can flow to the explosion-proof valve 1 through the exhaust channel between the electrode group 51 and the explosion-proof valve 1, and then be discharged through the explosion-proof valve 1. Since the support frame 6 can support the electrode assembly 5, this prevents the electrode group 51 from blocking the explosion-proof valve 1. In this way, the exhaust effect of the explosion-proof valve 1 is guaranteed, and the safety performance of the battery cell is improved.

[0051] In addition, the tray 3 can serve as insulation, eliminating the need for plastic parts and improving the space utilization of the battery cell casing 7.

[0052] Optionally, the thickness of pallet 3 is , The pallet 3 can be made of PP (Polypropylene). The tensile strength of the material of the pallet 3 is greater than 50 MPa, the elastic modulus is greater than 1100 MPa, and the elongation is greater than 85%. The entire pallet 3 is integrally molded.

[0053] In the embodiments of this application, such as Figure 10As shown, the electrode assembly 5 includes an electrode group 51 and an insulating film 52. A groove is formed on the side of the electrode group 51 facing the cover plate assembly. The shape of the insulating film 52 is adapted to the shape of the electrode group 51, so that the electrode assembly 5 forms a relief groove 53. The surface of the insulating film 52 facing the cover plate assembly is a contact surface 54. The relief groove 53 is recessed into the interior of the electrode assembly 5 relative to the contact surface 54. The insulating body 31 includes an extension 312 and two fitting portions 311. The two fitting portions 311 are respectively connected to the two ends of the extension 312 in the second direction F2. At least one of the extension 312 and the two fitting portions 311 has an exhaust hole 33. The extension 312 protrudes from the side away from the cover plate body 2 relative to the fitting portions 311. The fitting portions 311 fit against the contact surface 54. The extension 312 extends into the clearance groove 53 and contacts the groove wall of the clearance groove 53. A mounting groove 34 is formed on the side of the extension 312 opposite to the electrode assembly 51, and the support frame 6 is located in the mounting groove 34. In this way, the electrode assembly 51 is configured with a groove, so that the electrode assembly 5 forms a clearance groove 53. The extension portions 312 of the support frame 6 and the tray 3 are both located in the clearance groove 53. In the limited space of the housing 7, the electrode assembly 51 can occupy a large space, which ensures the capacity of the battery cell.

[0054] In addition, a vent hole 521 is provided on the insulating film 52 so that the gas inside the insulating film 52 can be discharged through the vent hole 521.

[0055] Optionally, the end face of the electrode assembly 51 on the side in the second direction F2 is the bonding surface. A vent hole 521 is provided in the area where the insulating film 52 is bonded to the bonding surface. The area where the insulating film 52 is bonded to the end face of the electrode assembly 51 facing the cover plate assembly is divided into three regions. The first region is bonded to the groove wall of the electrode assembly 51. The second and third regions are located on opposite sides of the first region in the second direction F2, respectively. Vent holes 521 are provided in both the first and second regions. When the battery cell is in use, the bonding surface and the second region are located on the upper side, and the third region is located on the lower side to prevent electrode powder from falling into the housing 7.

[0056] In addition, an exhaust hole 33 is provided on the extension 312 and on the fitting portion 311 that is in contact with the second region, so as to facilitate exhaust in case of thermal runaway. The diameter of the exhaust hole 33 is greater than or equal to 4 mm and less than or equal to 6 mm, and the total area of ​​the exhaust hole 33 accounts for 3%-6% of the surface area of ​​the insulating body 31 facing the electrode assembly 5.

[0057] Optionally, such as Figure 10 , Figure 11 and Figure 12 As shown, the dimension of electrode assembly 5 in the second direction F2 is When the support plate 3 is not assembled onto the electrode assembly 5, the dimension of the support plate 3 in the second direction F2 is: , and satisfy: This ensures that the support plate 3 and the electrode assembly 5 are interference-fitted, thereby guaranteeing the assembly stability of the support plate 3 while avoiding damage to the electrode sheets in the electrode assembly 51.

[0058] Furthermore, the dimension of electrode assembly 5 on the third direction F3 is... The dimensions of tray 3 on the third direction F3 are: , and satisfy: In this way, the support plate 3 can be prevented from protruding relative to the electrode assembly 5 while ensuring the insulation effect on the electrode assembly 5, so that the electrode assembly 5 and the support plate 3 can be installed into the housing 7 during the cell manufacturing process.

[0059] like Figure 11 As shown, the battery cell also includes multiple adhesive layers 4. One side of the adhesive layer 4 is bonded to the electrode assembly 5, and the other side of the adhesive layer 4 is bonded to the tray 3. In this way, by setting the adhesive layer 4, the stability of the tray 3 installation can be improved, so as to ensure the insulation effect between the electrode assembly 5 and the cover plate body 2, and between the electrode assembly 5 and the support frame 6.

[0060] Optionally, the total area of ​​the three sides of the tray facing the electrode assembly 51 is The total area of ​​the support plate 3 facing the pole group 51 here This is the sum of the area where the vent 33 is located, the area where it is bonded to the adhesive layer 4, and the areas of other areas facing the electrode assembly 5. The sum of the areas where the tray 3 is bonded to the multiple adhesive layers 4 is... . and satisfy: This reduces costs while ensuring adhesive stability.

[0061] Optionally, the number of adhesive layers 4 can be four, with one adhesive layer 4 attached to each extension 32 and two adhesive layers 4 attached to the location of the extension 312.

[0062] Optionally, the adhesive layer 4 is made of an insulating adhesive that is resistant to temperature and electrolyte and has good stability. The temperature range of the insulating adhesive is -40℃ to 85℃. The insulating adhesive has been tested according to GB / T2792-2014 standard and has a 180° peel force greater than 35N. According to ASTM D3654 standard test, the holding force meets the requirement of not falling off for more than 60 hours. According to GB / T31125-2014 standard test, the initial tack force is greater than 25N to ensure the bonding effect of the adhesive layer 4.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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; and these 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 the present invention.

Claims

1. A cover plate assembly, characterized in that, The cover plate assembly includes an explosion-proof valve, a cover plate body, and multiple support frames. The cover plate body has an installation port that extends through the cover plate body in a first direction, and the explosion-proof valve is disposed in the installation port. Multiple support frames are arranged at intervals along a second direction. Each support frame includes a support plate and two fixing members. The two fixing members are respectively connected to both ends of the support plate in a third direction. The fixing members protrude relative to the support plate toward the cover plate body. The two fixing members are respectively connected to the cover plate body. The two fixing members are located on both sides of the explosion-proof valve in the third direction. The support plate and the explosion-proof valve are arranged at intervals along a first direction. The first direction is perpendicular to the second direction. The third direction is perpendicular to the plane defined by the first direction and the second direction.

2. The cover plate assembly according to claim 1, characterized in that, The dimension of the explosion-proof valve in the second direction is: The dimension of the support frame in the second direction is The number of the support frames is , , and ,satisfy: .

3. The cover plate assembly according to claim 1 or 2, characterized in that, The fastener includes a fixing part and a connecting part. The two ends of the connecting part in the first direction are respectively connected to the fixing part and the support plate. The fixing part extends away from the support plate relative to the connecting part. The fixing part is connected to the cover plate body.

4. The cover plate assembly according to claim 3, characterized in that, A portion of the support plate protrudes along the side away from the cover plate body in the first direction to form a reinforcing rib; The support plate has a plurality of reinforcing ribs, which are spaced apart along the third direction.

5. The cover plate assembly according to claim 4, characterized in that, The thickness of the support frame is The distance between the two fixing parts in the third direction is , and satisfy: .

6. The cover plate assembly according to claim 4, characterized in that, Define the plane perpendicular to the first direction as the projection plane, and the sum of the areas of the projections of the plurality of reinforcing ribs along the first direction onto the projection plane is: The area of ​​the projection of the support plate onto the projection plane along the first direction is , and satisfy: .

7. The cover plate assembly according to claim 5, characterized in that, The dimension of the explosion-proof valve in the second direction is: , and satisfy: .

8. A battery cell, characterized in that, The battery cell includes an electrode assembly and a cover plate assembly according to any one of claims 1-7. The electrode assembly includes a contact surface and a clearance groove, the clearance groove being recessed from the contact surface toward the interior of the electrode assembly, and the support frame being located within the clearance groove.

9. The battery cell according to claim 8, characterized in that, The battery cell also includes a support plate, which includes an insulating body and two extensions. The two extensions are respectively connected to the two opposite ends of the insulating body. The insulating body covers the contact surface and the groove wall of the clearance groove. The two extensions are respectively attached to the two opposite ends of the electrode assembly.

10. The battery cell according to claim 9, characterized in that, The electrode assembly has a dimension in the second direction of: When the support plate is not mounted on the electrode assembly, the dimension of the support plate in the second direction is: , and satisfy: .

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