End cover assembly, energy storage device and electrical equipment

Abstract

A end cap assembly, an energy storage device and an electrical equipment, wherein the end cap assembly includes a current collecting plate and a cover plate, wherein the current collecting plate includes a main body, a protrusion and a boss, the main body includes a first surface and a second surface opposite to each other, the protrusion is arranged on the first surface, and the boss is arranged on the surface of the protrusion facing away from the main body, the current collecting plate is provided with an injection hole, and the injection hole passes through the surface of the boss facing away from the protrusion and the second surface; the cover plate includes a third surface and a fourth surface opposite to each other, the fourth surface faces the current collecting plate, and a sink is provided on the third surface. The cover plate is also provided with an assembly hole, and the assembly hole passes through the bottom wall of the sink and the fourth surface of the sink, the assembly hole is welded to the protrusion, the boss protrudes from the bottom wall of the sink, and the boss is lower than the third surface. By making the end cap assembly, the energy storage device and the electrical equipment meet the above structure, it is beneficial to avoid local overflow or splashing when the electrolyte is injected into the injection hole, thereby improving the safety of the battery assembly process.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an end cover assembly, an energy storage device, and an electrical equipment. Background Art

[0002] The recyclable nature of secondary batteries has made them gradually become the main power source for electrical equipment. Usually, the volume of the wound electrode assembly of the secondary battery is increased to improve the energy density per unit volume of the secondary battery, thereby improving the storage capacity of the secondary battery. When the volume of the wound electrode assembly is too large, the gap between it and the shell is small, which is not conducive to the electrolyte infiltration of the wound electrode assembly.

[0003] The injection hole is usually designed on the side of the current collecting plate with a bent extension, and the gap between the lower plastic plate and the bent extension of the current collecting plate is used to make the electrolyte flow more evenly to the wound electrode assembly. However, there is a current collecting plate blocking the bottom of the injection hole. During the injection process of the electrolyte, the electrolyte is prone to local overflow and splashing, the injection efficiency is low and the injection hole is contaminated. When the cover plate is subsequently welded at the injection hole, it is easy to explode, posing a safety hazard. Summary of the Invention

[0004] The purpose of this application is to provide an end cover assembly, an energy storage device and an electrical equipment to solve the problem of local overflow and splashing during the electrolyte injection process.

[0005] To achieve the purpose of this application, this application provides the following technical solutions:

[0006] In the first aspect, the present application provides an end cover assembly, comprising: a collecting plate, comprising a main body, a protrusion and a boss, the main body comprising a first surface and a second surface opposite to each other, the protrusion is arranged on the first surface, and the boss is arranged on the surface of the protrusion facing away from the main body, the collecting plate is provided with an injection hole, and the injection hole passes through the side of the boss facing away from the protrusion and the second surface; a cover plate, comprising a third surface and a fourth surface opposite to each other, the fourth surface faces the collecting plate, the third surface is provided with a sink, the cover plate is provided with an assembly hole, the assembly hole passes through the bottom wall of the sink and the fourth surface, the assembly hole is welded to the protrusion, the boss protrudes from the bottom wall of the sink, and the height of the boss protruding from the bottom wall of the sink is less than the depth of the sink.

[0007] By sequentially arranging the protrusions and the bosses on the collecting disc body, the collecting disc has a certain thickness at the places where the protrusions and the bosses are arranged, and the collecting disc is provided with an injection hole, and the injection hole passes through the surface of the boss facing away from the protrusion and the surface of the main body facing away from the protrusion, so that the electrolyte injected from the injection hole can directly reach the central part of the wound electrode assembly, which is beneficial to improving the injection efficiency of the electrolyte. At the same time, after the assembly hole provided in the cover plate is matched with the protrusion, the boss protrudes from the cover plate, so that the injection hole is exposed, and the injection hole passes through the main body, the protrusion and the boss, so that the injection hole has a certain length, providing a buffer space for the electrolyte to flow in the injection hole, and the electrolyte can be injected into the battery at a large flow rate and high speed, reducing the probability of local overflow and backsplash, and improving the safety of the secondary battery production process.

[0008] In one embodiment, the inner wall of the assembly hole is in close contact with the side wall of the protrusion.

[0009] In one embodiment, the protrusion includes a first protrusion and a second protrusion, the first protrusion is connected to the main body, the second protrusion is connected to the side of the first protrusion facing away from the main body, the orthographic projection area of ​​the second protrusion on the main body is smaller than the orthographic projection area of ​​the first protrusion on the main body, and the orthographic projection of the second protrusion completely falls within the orthographic projection range of the first protrusion, the inner wall of the assembly hole is in close contact with the side wall of the second protrusion, and the boss is arranged on the side of the second protrusion facing away from the first protrusion.

[0010] In one embodiment, the maximum radius of the second protrusion is smaller than the minimum radius of the first protrusion.

[0011] In one embodiment, the protrusion also includes a third protrusion, which is connected to the side of the second protrusion facing away from the first protrusion, the orthographic projection area of ​​the third protrusion on the main body is smaller than the orthographic projection area of ​​the second protrusion on the main body, the inner wall of the assembly hole is in close contact with the side walls of the second protrusion and the third protrusion, and the boss is arranged on the side of the third protrusion facing away from the second protrusion.

[0012] In one embodiment, the maximum radius of the boss is smaller than the minimum radius of the third protrusion.

[0013] In one embodiment, the first protrusion and the third protrusion are both cylindrical, the second protrusion is truncated cone-shaped, and the maximum radius of the third protrusion is equal to the minimum radius of the second protrusion.

[0014] In one embodiment, the first protrusion, the second protrusion, and the third protrusion are all rotationally symmetric around the center line of the liquid injection hole.

[0015] In one embodiment, the injection hole passes through the surface of the boss facing away from the convex portion and the second surface, and the boss is rotationally symmetrical around the center line of the injection hole.

[0016] In one embodiment, a groove is formed on a surface of the boss facing away from the convex portion, and the injection hole passes through the bottom wall of the groove and the second surface, so that the boss surrounds the injection hole.

[0017] In one embodiment, the maximum radius of the liquid injection hole is smaller than the minimum radius of the bottom wall of the groove.

[0018] In one embodiment, the height of the protrusion protruding from the bottom wall of the sink is the same as the height of the bottom wall of the sink.

[0019] In one embodiment, the end cover assembly further includes a cover plate, which is welded to the boss and closes the liquid injection hole.

[0020] In one embodiment, the height of the cover relative to the bottom wall of the sink is smaller than the depth of the sink.

[0021] In one embodiment, the cover plate includes a top plate and an annular sleeve, the top plate is connected to one end of the annular sleeve, the annular sleeve is sleeved on the outer periphery of the boss, and the top plate cover is arranged on the surface of the boss facing away from the convex portion.

[0022] In one embodiment, the cover plate is welded to the collecting plate to form a welding ring, the welding ring is located on the outer peripheral surface of the protrusion, the orthographic projection of the annular sleeve on the main body and the orthographic projection of the welding ring on the main body have a preset distance, and the annular sleeve is welded to the bottom wall of the sink.

[0023] In one embodiment, the welding ring is connected to the annular sleeve, the protrusion and the cover plate.

[0024] In one embodiment, the preset distance is 1 mm to 4 mm.

[0025] In the second aspect, the present application also provides an energy storage device, which includes an electrode assembly, a shell, and an end cap assembly described in any embodiment of the first aspect, wherein the electrode assembly is arranged in the shell, the end cap assembly is electrically connected to the electrode assembly, and the end cap assembly is connected to the shell and seals the shell.

[0026] In a third aspect, the present application further provides an electrical device, which includes the energy storage device described in the second aspect, and the energy storage device is used to supply power to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the implementation methods or the description of the prior art. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a schematic diagram of a scenario of an energy storage device according to an embodiment;

[0029] Figure 2 is a schematic structural diagram of an end cap assembly according to an embodiment;

[0030] Figure 3A yes Figure 2 Exploded diagram of the middle end cover assembly;

[0031] Figure 3B for Figure 3A A partial enlarged schematic diagram;

[0032] Figure 4 is a schematic top view of a current collecting plate according to an embodiment;

[0033] Figure 5 yes Figure 4 Schematic diagram of the cross section of the middle collecting plate along AA;

[0034] Figure 6 This is a schematic structural diagram of an end cap assembly provided with a groove according to an embodiment;

[0035] Figure 7 yes Figure 6 An exploded schematic diagram of an end cap assembly having a groove therein;

[0036] Figure 8 is a schematic top view of a current collecting plate provided with grooves according to an embodiment;

[0037] Figure 9 yes Figure 8 A schematic cross-sectional view of a collecting plate with grooves along BB;

[0038] Figure 10 This is a schematic structural diagram of a cover plate according to an embodiment;

[0039] Figure 11 yes Figure 10 Schematic diagram of the cross section of the middle cover along CC;

[0040] Figure 12 is a schematic structural diagram of a cover sheet according to an embodiment;

[0041] Figure 13 yes Figure 12Schematic diagram of the cross section of the middle cover piece along DD;

[0042] Figure 14 is a schematic structural diagram of a cover sheet according to another embodiment;

[0043] Figure 15 yes Figure 14 Schematic diagram of the cross section of the middle cover piece along EE;

[0044] Figure 16 This is a schematic structural diagram of an energy storage device according to an embodiment.

[0045] Description of reference numerals:

[0046] 100-energy storage device, 101-end cover assembly, 102-housing, 200-power generation equipment, 300-power consumption equipment;

[0047] 10-collecting plate, 20-cover plate, 30-cover sheet;

[0048] 11-main body, 12-convex part, 13-boss, 14-liquid injection hole;

[0049] 111-first surface, 112-second surface;

[0050] 121-first protrusion, 122-second protrusion, 123-third protrusion;

[0051] 131-groove;

[0052] 21-third surface, 22-fourth surface, 23-assembly hole, 24-sink, 25-explosion-proof valve;

[0053] 31-top plate, 32-annular sleeve, 33-air pressure groove. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of 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.

[0055] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may be an intermediate component. When a component is referred to as being "connected to" another component, it may be directly connected to the other component or there may be an intermediate component.

[0056] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used in this application includes any and all combinations of one or more of the relevant listed items.

[0057] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0058] Since the energy people need is highly temporal and spatial, in order to make rational use of energy and improve energy utilization, it is necessary to use a medium or device to store one form of energy in the same form or convert it into another form of energy, and then release it in a specific form of energy based on future application needs.

[0059] Currently, the generation of green electricity generally relies on photovoltaics, wind power, hydropower, etc. However, wind and solar energy generally have problems of strong intermittency and large fluctuations, which can cause grid instability, insufficient electricity during peak hours, and excessive electricity during off-peak hours. Unstable voltage can also damage electricity. Therefore, insufficient electricity demand or insufficient grid acceptance capacity may lead to the problem of "wind and solar power abandonment". To solve these problems, we must rely on energy storage, that is, converting electrical energy into other forms of energy through physical or chemical means and storing it, and then converting the energy into electrical energy when needed. Simply put, energy storage is like a large "power bank", storing electrical energy when photovoltaic and wind energy are sufficient, and releasing the stored electricity when needed.

[0060] Taking electrochemical energy storage as an example, an embodiment of the present application provides an energy storage device 100. A chemical battery is provided in the energy storage device 100, which mainly uses the chemical elements in the chemical battery as an energy storage medium. The charging and discharging process is accompanied by chemical reactions or changes in the energy storage medium. Simply put, the electricity generated by wind and solar energy is stored in the chemical battery. When the use of external electricity reaches a peak, the stored electricity is released for use, or transferred to places where electricity is scarce for use.

[0061] Current energy storage (i.e., energy storage) has a wide range of application scenarios, including power generation-side energy storage, grid-side energy storage, renewable energy grid-connected energy storage, and user-side energy storage. The corresponding types of energy storage devices 100 include:

[0062] (1) Large energy storage containers used in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the grid, achieving load matching of electricity in time and space, enhancing the ability to absorb renewable energy, and are of great significance in grid system backup, alleviating peak load power supply pressure, and peak and frequency regulation;

[0063] (2) The main operating mode of small and medium-sized energy storage cabinets used in industrial and commercial energy storage scenarios (banks, shopping malls, etc.) on the user side and small household energy storage boxes used in home energy storage scenarios on the user side is "peak shaving and valley filling". Since there is a large price difference in electricity prices at peak and valley locations according to electricity demand, after users have energy storage equipment, in order to reduce costs, they usually charge the energy storage cabinets / boxes during the low electricity price period; during the peak electricity price period, the electricity in the energy storage equipment is discharged for use to achieve the purpose of saving electricity bills. In addition, in remote areas and areas with high incidence of natural disasters such as earthquakes and hurricanes, the existence of household energy storage devices is equivalent to users providing themselves and the power grid with backup power, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0064] The embodiments of the present application are described using a household energy storage scenario in user-side energy storage as an example. The energy storage device provided in the embodiments of the present application is not limited to the household energy storage scenario.

[0065] The present application embodiment provides a household energy storage system, such as Figure 1 As shown, the household energy storage system includes power generation equipment 200, power consumption equipment 300, and an energy storage device 100. The energy storage device 100 is a small energy storage box that can be mounted on an outdoor wall. The power consumption equipment 300 can be a street lamp or household appliance. Specifically, the power generation equipment 200 can be a photovoltaic panel that converts solar energy into electricity during periods of low electricity prices. The energy storage device 100 is used to store this electricity and supply it to street lamps and household appliances during peak electricity prices, or to provide power during power outages.

[0066] It is understood that the energy storage device 100 may include but is not limited to a single cell, a battery module, a battery pack, a battery system, etc. When the energy storage device is a single cell, it may be a cylindrical battery or a square battery.

[0067] This embodiment of the present application provides an end cap assembly 101, please refer to Figure 2 、 Figure 3A 、 Figure 4 、 Figure 5 、 Figure 10 and Figure 16The end cover assembly 101 includes a collecting plate 10 and a cover plate 20, wherein the collecting plate 10 includes a main body 11, a protrusion 12 and a boss 13, the main body 11 includes a first surface 111 and a second surface 112 opposite to each other, the protrusion 12 is arranged on the first surface 111, and the boss 13 is arranged on the surface of the protrusion 12 facing away from the main body 11, and the collecting plate 10 is provided with a liquid injection hole 14, which passes through the side of the boss 13 facing away from the protrusion 12 and the second surface 112.

[0068] The side of the main body 11 of the current collecting disc 10, facing away from the protrusion 12 and the boss 13, is used for welding to the battery's tab. The current collecting disc 10 includes a positive current collecting disc 10 and a negative current collecting disc 10. The positive current collecting disc 10 is connected to the positive tab of the wound electrode assembly, and the negative current collecting disc 10 is connected to the negative tab of the wound electrode assembly. Optionally, a liquid injection hole 14 is located in the center of the current collecting disc 10 and is used to inject liquid into the center portion of the wound electrode assembly.

[0069] Optionally, the opening of the injection hole 14 on the side of the boss 13 facing away from the convex portion 12 and the opening on the second surface 112 are both circular, and the injection hole 14 does not bend on the path from the surface of the boss 13 facing away from the convex portion 12 to the second surface 112, so that the injection hole 14 as a whole forms a cylindrical vertical through hole, so that a large amount of electrolyte can flow directly into the central area of ​​the wound electrode assembly, thereby improving the electrolyte injection efficiency and thereby improving the production efficiency of the secondary battery.

[0070] Since the main body 11, the protrusion 12 and the boss 13 all have a certain thickness, the injection hole 14 that passes through the main body 11, the protrusion 12 and the boss 13 has a certain length. When the electrolyte is injected from the injection hole 14, the length of the injection hole 14 provides a certain buffer space for the flow of the electrolyte, so that the electrolyte can be injected at a large flow rate and high speed, reducing the probability of local overflow and splashing of the electrolyte.

[0071] The cover plate 20 is provided with an assembly hole 23. When the cover plate 20 is assembled with the collecting plate 10, the boss 13 passes through the assembly hole 23, and the assembly hole 23 is matched with the convex portion 12. When the assembly hole 23 is matched with the convex portion 12, the inner wall of the assembly hole 23 can be fitted with the side wall of the convex portion 12, or can be in contact with the side wall portion of the convex portion 12. The cover plate 20 is welded to the convex portion 12 at the assembly hole 23 to seal the assembly hole 23. After the cover plate 20 is connected to the convex portion 12, the boss 13 protrudes from the cover plate 20.

[0072] Optionally, the cover plate 20 and the main board of the collecting plate 10 are both sheet structures, including but not limited to round or square. The shapes of the cover plate 20 and the main board can be the same or different. Preferably, the cover plate 20 and the main board have the same shape and size, and after the cover plate 20 is connected to the protrusion 12, the cover plate 20 is parallel to the main board.

[0073] Optionally, the injection hole 14 passes through the surface of the boss 13 facing away from the convex portion 12 and the second surface 112. The edge of the opening of the injection hole 14 at the surface of the boss 13 facing away from the convex portion 12 is flush with the surface of the boss 13 facing away from the convex portion 12, and the surface of the boss 13 facing away from the convex portion 12 is parallel to the cover plate 20, which is conducive to simplifying the process of opening the injection hole 14, so that the electrolyte injected from the injection hole 14 can directly reach the central part of the wound electrode assembly, thereby improving the electrolyte injection efficiency.

[0074] Since the boss 13 protrudes from the cover plate 20, the surface of the boss 13 facing away from the convex portion 12 is spaced apart from the cover plate 20, and the opening of the liquid injection hole 14 at the surface of the boss 13 facing away from the convex portion 12 is spaced apart from the cover plate 20. Therefore, when the cover plate 20 is welded to the collecting plate 10, the welding area thereof is spaced apart from the liquid injection hole 14, which helps to prevent welding slag from falling into the interior of the battery through the liquid injection hole 14 and causing a safety hazard of short circuit.

[0075] By sequentially arranging the protrusions 12 and the bosses 13 on the main body 11 of the current collecting disc 10, the current collecting disc 10 has a certain thickness at the locations where the protrusions 12 and the bosses 13 are provided, and the current collecting disc 10 is provided with an injection hole 14, and the injection hole 14 passes through the side of the boss 13 facing away from the protrusion 12 and the surface of the main body 11 facing away from the protrusion 12, so that the electrolyte injected from the injection hole 14 can directly reach the central part of the wound electrode assembly, which is beneficial to improving the injection efficiency of the electrolyte. At the same time, after the assembly hole 23 opened in the cover plate 20 is matched and connected with the protrusion 12, the boss 13 protrudes from the cover plate 20, so that the injection hole 14 is exposed, and the injection hole 14 passes through the main body 11, the protrusion 12 and the boss 13, so that the injection hole 14 has a certain length, providing a buffer space for the electrolyte to flow in the injection hole 14, and the electrolyte can be injected into the battery at a large flow rate and high speed, reducing the probability of local overflow and backsplash, and improving the safety of the secondary battery production process.

[0076] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 4 、 Figure 5 、 Figure 10 and Figure 11 The cover plate 20 includes a third surface 21 and a fourth surface 22 facing each other, the fourth surface 22 faces the collecting plate 10, and a sink 24 is opened on the third surface 21. The bottom wall of the sink 24 is lower than the third surface 21. The assembly hole 23 passes through the bottom wall of the sink 24 and the fourth surface 22, so the assembly hole 23 is lower than the third surface 21. When the assembly hole 23 is connected with the protrusion 12, the boss 13 protrudes from the bottom wall of the sink 24, and the height of the boss 13 protruding from the bottom wall of the sink 24 is less than the depth of the sink 24.

[0077] There is a spacing distance between the assembly hole 23 and the side wall of the sink 24, and there is a spacing distance between the outer peripheral surface of the protrusion 12 and the side wall of the sink 24, and this spacing distance is the same as the spacing distance between the assembly hole 23 and the side wall of the sink 24. There is a spacing distance between the outer peripheral surface of the boss 13 and the side wall of the sink 24, and this spacing distance is the sum of the spacing distance between the outer peripheral surface of the boss 13 and the outer peripheral surface of the protrusion 12 and the spacing distance between the assembly hole 23 and the side wall of the sink 24. Therefore, by changing the spacing distance between the assembly hole 23 and the side wall of the sink 24, the spacing distance between the side wall of the sink 24 and the protrusion 12 and the boss 13 can be changed.

[0078] The bottom wall of the groove 24 is lower than the surface of the boss 13 facing away from the convex portion 12. Optionally, the bottom wall of the groove 24 is lower than the surface of the convex portion 12 facing away from the main body 11; or, the bottom wall of the groove 24 is flush with the surface of the convex portion 12 facing away from the main body 11, so that the groove 24 has a certain depth, which is convenient for the groove 24 to accommodate the boss 13 and part of the convex portion 12, which is beneficial for the groove 24 to protect the boss 13 and convex portion 12 and other structures of the collecting plate 10, and provide space for the arrangement of relevant structures for the subsequent sealing of the injection hole 14 at the boss 13. At the same time, it is also beneficial to avoid the boss 13 protruding from the third surface 21, which causes interference with the bottom plate of the module during module assembly. Excessive protrusion of the boss 13 is also prone to cause bumps, affecting the sealing performance at the injection hole 14.

[0079] Optionally, the sink 24 is located in the central area of ​​the third surface 21, and the assembly hole 23 is located in the central area of ​​the bottom wall of the sink 24, so that the side walls of the sink 24 evenly surround the boss 13 and the convex portion 12, which is beneficial for the sink 24 to protect the boss 13 and the convex portion 12. At the same time, it also provides a space for setting a sealing structure for sealing the injection hole 14 at the boss 13.

[0080] Optionally, the assembly hole 23 is circular, the bottom wall and opening of the sink 24 are both circular, the center line of the assembly hole 23 coincides with the center line of the injection hole 14 , and the side walls of the sink 24 are rotationally symmetrical around the center line of the assembly hole 23 .

[0081] Optionally, the trough 24 has vertical side walls, and the opening size of the trough 24 is equal to the size of the bottom wall of the trough 24 ; or, the trough 24 has inclined side walls, and the opening size of the trough 24 is larger than the size of the bottom wall of the trough 24 .

[0082] Optionally, the third surface 21 is further provided with an explosion-proof valve 25 . The explosion-proof valve 25 is close to the edge of the third surface 21 , and there is a spacing distance between the explosion-proof valve 25 and the side wall of the sink 24 .

[0083] By making the cover plate 20 include a third surface 21 and a fourth surface 22 facing each other, the fourth surface 22 faces the collecting plate 10, the third surface 21 is provided with a sink 24, the assembly hole 23 passes through the bottom wall of the sink 24 and the fourth surface 22, the boss 13 protrudes from the bottom wall of the sink 24, and the height of the boss 13 protruding from the bottom wall of the sink 24 is less than the depth of the sink 24, so that the sink 24 has a certain depth, which is convenient for the sink 24 to accommodate the boss 13, and is beneficial for the sink 24 to protect the boss 13 and prevent the boss 13 from protruding from the third surface. The surface 21 causes interference with the bottom plate of the module during module assembly. At the same time, it also provides an installation space for the sealing structure of the injection hole 14 at the boss 13, avoiding collision between the protrusion at the boss 13 and the bottom plate of the module, resulting in deformation of the structure at the boss 13, and further affecting the sealing performance of the injection hole 14. Furthermore, the structures of the third surface 21 and the fourth surface 22 of the cover plate 20 are significantly different, which is beneficial to improving the accuracy of the installation direction of the cover plate 20 during the installation process and improving the production yield of the secondary battery.

[0084] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 4 、 Figure 5 and Figure 10 , the inner wall of the assembly hole 23 is in close contact with the side wall of the protrusion 12.

[0085] Optionally, when the assembly hole 23 is connected with the protrusion 12, the inner wall of the assembly hole 23 is completely fitted with the side wall of the protrusion 12. The protrusion 12 can be cylindrical, and the side wall of the protrusion 12 is vertical. At this time, the assembly hole 23 is a circular through hole, the inner wall of the assembly hole 23 is vertical, and the area of ​​the assembly hole 23 is the same as the area of ​​the circular bottom surface of the protrusion 12; the protrusion 12 can also be truncated cone-shaped, in which case the inner wall of the assembly hole 23 is inclined, and the inclination angle of the inner wall is the same as the inclination angle of the side wall of the protrusion 12.

[0086] Optionally, when the assembly hole 23 is mated with the protrusion 12, the inner wall of the assembly hole 23 fits partially with the side wall of the protrusion 12, such as one side of the inner wall of the assembly hole 23 contacts the side wall of the protrusion 12. The protrusion 12 can be cylindrical, and the side wall of the protrusion 12 is vertical. In this case, the inner wall of the assembly hole 23 is inclined; the protrusion 12 can also be truncated cone-shaped. In this case, the inner wall of the assembly hole 23 can be inclined, and the inclination angle of the inner wall is different from the inclination angle of the side wall of the protrusion 12, or the inner wall of the assembly hole 23 is vertical.

[0087] Taking the direction from the main body 11 to the boss 13 as the height direction, optionally, the height of the inner wall of the assembly hole 23 is the same as the height of the side wall of the protrusion 12; or, the height of the inner wall of the assembly hole 23 is less than the height of the side wall of the protrusion 12, that is, the thickness of the cover plate 20 is less than the thickness of the protrusion 12, and the inner wall of the assembly hole 23 contacts a partial area of ​​the side wall of the protrusion 12.

[0088] The cover plate 20 includes two opposing surfaces, and the assembly hole 23 passes through the two opposing surfaces. Optionally, the inner wall of the assembly hole 23 is welded to the side wall of the protrusion 12 to connect the cover plate 20 to the collecting plate 10; or, at least one of the two opposing surfaces of the cover plate 20 is welded to the side wall of the protrusion 12.

[0089] By making the inner wall of the assembly hole 23 in close contact with the side wall of the protrusion 12, it is beneficial to achieve the matching connection between the assembly hole 23 and the protrusion 12, making it easier to install the cover plate 20 on the collecting plate 10. At the same time, the contact area between the inner wall of the assembly hole 23 and the side wall of the protrusion 12 is increased, making the welding connection process between the cover plate 20 and the protrusion 12 more convenient and increasing the stability of the connection between the cover plate 20 and the protrusion 12.

[0090] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 3B 、 Figure 4 and Figure 5 The protrusion 12 includes a first protrusion 121 and a second protrusion 122. The first protrusion 121 is connected to the main body 11, and the second protrusion 122 is connected to the side of the first protrusion 121 facing away from the main body 11. The boss 13 is arranged on the side of the second protrusion 122 facing away from the first protrusion 121.

[0091] The first protrusion 121 and the second protrusion 122 both have a certain height. The height of the first protrusion 121 and the height of the second protrusion 122 may be the same or different. Optionally, the height of the first protrusion 121, the height of the second protrusion 122 and the height of the boss 13 are all the same.

[0092] The orthographic projection area of ​​the second protrusion 122 on the main body 11 is smaller than the orthographic projection area of ​​the first protrusion 121 on the main body 11, and the orthographic projection of the second protrusion 122 completely falls within the orthographic projection range of the first protrusion 121. The inner wall of the assembly hole 23 is in close contact with the side wall of the second protrusion 122, that is, the inner wall of the assembly hole 23 is connected to the side wall of the second protrusion 122.

[0093] When the cover plate 20 is connected to the second protrusion 122, the first protrusion 121 is located between the cover plate 20 and the main body 11 of the current collecting disk 10. The first protrusion 121 has a certain height, so that the cover plate 20 is spaced apart from the main body 11, and the spacing distance is the height of the first protrusion 121, so that a buffer space is formed between the cover plate 20 and the main body 11. When the wound electrode assembly heats up and expands, the main body 11 of the current collecting disk 10 can deform to absorb the pressure generated by the expansion of the wound motor assembly. The buffer space provides space for the deformation of the main body 11 of the current collecting disk 10, so that the pressure can be fully released, thereby improving the safety of the secondary battery during use.

[0094] Optionally, the surface of the cover 20 facing the main body 11 is fitted with the surface of the first protrusion 121 facing away from the main body 11, and the first protrusion 121 provides a certain support for the cover 20, making the welding connection process between the cover 20 and the second protrusion 122 more convenient and increasing the stability of the connection between the cover 20 and the second protrusion 122.

[0095] The central axes of the first protrusion 121 and the second protrusion 122 may coincide. Optionally, the shape of the first protrusion 121 and the second protrusion 122 may be the same, such as both being cylindrical. Alternatively, the shape of the first protrusion 121 and the second protrusion 122 may be different, such as the first protrusion 121 being a cuboid and the second protrusion 122 being cylindrical. In other words, the support area of ​​the first protrusion 121 on the cover plate 20 can be adjusted by adjusting the shape of the first protrusion 121.

[0096] Optionally, the orthographic projection area of ​​the boss 13 on the main body 11 is smaller than the orthographic projection area of ​​the second protrusion 122 on the main body 11. When the cover plate 20 is connected to the side wall of the second protrusion 122, the outer peripheral surface of the boss 13 is spaced apart from the connection between the cover plate 20 and the second protrusion 122, which is beneficial to further prevent welding slag generated during the welding of the cover plate 20 and the second protrusion 122 from falling into the injection hole 14 at the boss 13; or, the orthographic projection area of ​​the boss 13 on the main body 11 is equal to the orthographic projection area of ​​the second protrusion 122 on the main body 11. When the cover plate 20 is connected to the side wall of the second protrusion 122, the outer peripheral surface of the boss 13 is connected to the connection between the cover plate 20 and the second protrusion 122. The boss 13 and the second protrusion 122 can be an integrated structure, which is beneficial to simplify the manufacturing process of the boss 13 and the second protrusion 122.

[0097] By making the convex portion 12 include a first protrusion 121 and a second protrusion 122, the first protrusion 121 is connected to the main body 11, the second protrusion 122 is connected to the side of the first protrusion 121 facing away from the main body 11, the orthographic projection area of ​​the second protrusion 122 on the main body 11 is smaller than the orthographic projection area of ​​the first protrusion 121 on the main body 11, and the orthographic projection of the second protrusion 122 completely falls within the orthographic projection range of the first protrusion 121, the boss 13 is arranged on the side of the second protrusion 122 facing away from the first protrusion 121, which is conducive to the boss 13 and the second protrusion 122 smoothly passing through the assembly hole 23, so that the inner wall of the assembly hole 23 is in close contact with the side wall of the second protrusion 122, and the first protrusion 121 is arranged between the cover plate 20 and the main body 11 of the current collecting disk 10, so that the cover plate 20 is spaced apart from the main body 11, and the spacing distance is the height of the first protrusion 121, which is conducive to forming a buffer space between the cover plate 20 and the main body 11 of the current collecting disk 10. When the wound electrode assembly heats up and expands, a buffer space is provided for the deformation caused by the heat and expansion of the wound motor assembly, so that the pressure at the wound motor assembly can be fully released, thereby improving the safety of the secondary battery during use.

[0098] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 4 and Figure 5 The maximum radius of the second protrusion 122 is smaller than the minimum radius of the first protrusion 121, so that the area of ​​the first protrusion 121 is larger than the area of ​​the second protrusion 122. Optionally, when the cover plate 20 is connected to the side wall of the second protrusion 122, the surface of the cover plate 20 facing the main body 11 of the current collecting tray 10 contacts the surface of the first protrusion 121 facing away from the main body 11, and the first protrusion 121 supports the cover plate 20.

[0099] When the first protrusion 121 and the second protrusion 122 are cylindrical with their central axes coinciding, the first protrusion 121 forms an annular platform around the second protrusion 122, which can evenly support the cover plate 20, so that when the cover plate 20 is welded to the second protrusion 122, the installation of the cover plate 20 is more stable, which helps to avoid the cover plate 20 from shifting during the welding process and causing the cover plate 20 to tilt. At the same time, the first protrusion 121 always supports the cover plate 20, which also helps to increase the stability of the connection between the cover plate 20 and the second protrusion 122.

[0100] By making the maximum radius of the second protrusion 122 smaller than the minimum radius of the first protrusion 121, the first protrusion 121 can evenly support the cover plate 20, preventing the cover plate 20 from tilting during the welding process, making the connection process between the cover plate 20 and the second protrusion 122 more stable, and making the matching structure between the cover plate 20 and the second protrusion 122 more regular, thereby improving the production yield of the secondary battery. At the same time, the first protrusion 121 always supports the cover plate 20, which is conducive to increasing the stability of the connection between the cover plate 20 and the second protrusion 122.

[0101] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 3B 、 Figure 4 and Figure 5 The protrusion 12 further includes a third protrusion 123 , which is connected to a side of the second protrusion 122 facing away from the first protrusion 121 , and the boss 13 is arranged on a side of the third protrusion 123 facing away from the second protrusion 122 .

[0102] The first protrusion 121 , the second protrusion 122 and the third protrusion 123 all have a certain height. Optionally, the first protrusion 121 and the second protrusion 122 have the same height, and the third protrusion 123 has a height less than the second protrusion 122 or the third protrusion 123 .

[0103] The orthographic projection area of ​​the third protrusion 123 on the main body 11 is smaller than the orthographic projection area of ​​the second protrusion 122 on the main body 11, and the inner wall of the assembly hole 23 is in close contact with the side walls of the second protrusion 122 and the third protrusion 123, that is, the inner wall of the assembly hole 23 is connected to the side walls of the second protrusion 122 and the side walls of the third protrusion 123 at the same time.

[0104] When the cover plate 20 is connected to the second protrusion 122 and the third protrusion 123, similarly, the first protrusion 121 is located between the cover plate 20 and the main body 11 of the collecting plate 10. Optionally, the orthographic projection area of ​​the boss 13 on the main body 11 is smaller than the orthographic projection area of ​​the third protrusion 123 on the main body 11, and the outer peripheral surface of the boss 13 is spaced apart from the connection between the cover plate 20 and the third protrusion 123; or, the orthographic projection area of ​​the boss 13 on the main body 11 is equal to the orthographic projection area of ​​the third protrusion 123 on the main body 11, and the boss 13 and the third protrusion 123 are an integrated structure.

[0105] Optionally, the surface of the cover plate 20 facing the main body 11 contacts the surface of the first protrusion 121 facing away from the main body 11, and the surface of the cover plate 20 facing away from the main body 11 is flush with the surface of the third protrusion 123 facing away from the second protrusion 122, which is beneficial to increase the connection area between the cover plate 20 and the protrusion 12, and improve the stability of the connection between the cover plate 20 and the second protrusion 122 and the third protrusion 123.

[0106] The shape of the third protrusion 123 and the shape of the second protrusion 122 can be the same or different. Since the orthographic projection area of ​​the third protrusion 123 on the main body 11 is smaller than the orthographic projection area of ​​the second protrusion 122 on the main body 11, the inner wall shape of the assembly hole 23 corresponds to the second protrusion 122 and the third protrusion 123. The opening of the assembly hole 23 at the surface of the cover plate 20 facing the main body 11 has a first aperture, and the opening of the assembly hole 23 at the surface of the cover plate 20 facing away from the main body 11 has a second aperture. The size of the first aperture is larger than the size of the second aperture. The aperture sizes of the assembly hole 23 on both sides of the cover plate 20 are different. When the cover plate 20 is installed to the collecting plate 10, it is helpful to prevent the cover plate 20 from being installed upside down.

[0107] By making the protrusion 12 also include a third protrusion 123, the third protrusion 123 is connected to the side of the second protrusion 122 facing away from the first protrusion 121, the orthographic projection area of ​​the third protrusion 123 on the main body 11 is smaller than the orthographic projection area of ​​the second protrusion 122 on the main body 11, the inner wall of the assembly hole 23 is in close contact with the side walls of the second protrusion 122 and the third protrusion 123, and the boss 13 is arranged on the side of the third protrusion 123 facing away from the second protrusion 122, thereby increasing the connection area between the cover plate 20 and the protrusion 12, making the connection between the cover plate 20 and the protrusion 12 more stable, and improving the sealing of the connection between the cover plate 20 and the collecting plate 10. At the same time, the size of the third protrusion 123 is different from that of the second protrusion 122, which is conducive to preventing the cover plate 20 from being installed upside down when it is installed on the protrusion 12, thereby improving the production yield of the secondary battery.

[0108] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 3B 、 Figure 4 and Figure 5 The maximum radius of boss 13 is smaller than the minimum radius of third protrusion 123, resulting in an area of ​​third protrusion 123 larger than that of boss 13. When cover plate 20 is connected to the sidewalls of second protrusion 122 and third protrusion 123, a distance is provided between the outer circumference of boss 13 and the connection between cover plate 20 and third protrusion 123. This helps prevent welding slag generated during welding of cover plate 20 and third protrusion 123 from falling into injection hole 14 on boss 13.

[0109] By making the maximum radius of the boss 13 smaller than the minimum radius of the third protrusion 123, when the cover plate 20 is welded to the third protrusion 123, the welding area thereof is spaced apart from the injection hole 14 at the boss 13. This helps to prevent welding slag from falling into the interior of the battery through the injection hole 14 and causing a safety hazard of a short circuit.

[0110] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 3B 、 Figure 4 and Figure 5 The first protrusion 121 and the third protrusion 123 are both cylindrical, the second protrusion 122 is frustum-shaped, the maximum radius of the third protrusion 123 is equal to the minimum radius of the second protrusion 122, and the area of ​​the second protrusion 122 close to the first protrusion 121 is larger than the area of ​​the second protrusion 122 close to the third protrusion 123, so that the area of ​​the third protrusion 123 is equal to the area of ​​the second protrusion 122 close to the third protrusion 123.

[0111] Specifically, the second protrusion 122 includes an upper surface and a lower surface facing each other, both of which are circular, and the area of ​​the upper surface is smaller than that of the lower surface. The third protrusion 123 is arranged on the upper surface, and the lower surface is connected to the first protrusion 121. The area of ​​the circular bottom surface of the first protrusion 121 is larger than the area of ​​the lower surface, so that the outer peripheral surface of the second protrusion 122 is spaced apart from the outer peripheral surface of the first protrusion 121. The area of ​​the circular bottom surface of the third protrusion 123 is equal to the area of ​​the upper surface, so that the outer peripheral surface of the third protrusion 123 is connected to the outer peripheral surface of the second protrusion 122.

[0112] The third protrusion 123 has a vertical side wall, and the second protrusion 122 has an inclined side wall. The outer peripheral surface of the third protrusion 123 is connected to the outer peripheral surface of the second protrusion 122, so that an angle is formed between the side walls of the third protrusion 123 and the second protrusion 122, that is, a welding area with an angle can be formed. When the inner wall of the assembly hole 23 is laser-welded to the side walls of the second protrusion 122 and the side walls of the third protrusion 123, a higher power laser beam can be used to improve the welding efficiency. At the same time, compared with the third protrusion 123 and the second protrusion 122 both having vertical side walls and the welding area having no angle, the provision of the welding area with an angle also increases the welding width on the welding cross section, which is beneficial to further improve the sealing of the connection between the cover plate 20 and the collecting plate 10.

[0113] Optionally, the boss 13 is cylindrical, and the outer peripheral surface of the boss 13 is spaced apart from the outer peripheral surface of the third protrusion 123. When the cover plate 20 is connected to the third protrusion 123 and the second protrusion 122, the outer peripheral surface of the boss 13 is spaced apart from the connection between the cover plate 20 and the third protrusion 123, which is beneficial to prevent welding slag generated during welding of the cover plate 20 and the third protrusion 123 and the second protrusion 122 from falling into the injection hole 14 at the boss 13.

[0114] By making the first protrusion 121 and the third protrusion 123 both cylindrical, the second protrusion 122 truncated cone, and the maximum radius of the third protrusion 123 equal to the minimum radius of the second protrusion 122, it is conducive to forming an angle between the side wall of the third protrusion 123 and the side wall of the second protrusion 122, forming a welding area with an angle, and facilitating the use of a higher-power laser beam to weld the inner wall of the assembly hole 23 with the side wall of the second protrusion 122 and the side wall of the third protrusion 123, thereby improving the welding efficiency of the cover plate 20 and the collecting plate 10. At the same time, it is also conducive to increasing the welding width on the welding cross section, further improving the sealing of the connection between the cover plate 20 and the collecting plate 10.

[0115] In one embodiment, please refer to Figure 4 and Figure 5 The first protrusion 121, the second protrusion 122 and the third protrusion 123 are all rotationally symmetrical around the center line of the injection hole 14, so that the injection hole 14 is located at the center position of the first protrusion 121, the second protrusion 122 and the third protrusion 123. The injection hole 14 runs through the first protrusion 121, the second protrusion 122 and the third protrusion 123, so that the injection hole 14 has a certain length, which is conducive to the electrolyte being injected into the injection hole 14 at a large flow rate and high speed.

[0116] Optionally, the liquid injection hole 14 is a cylindrical vertical through hole.

[0117] By making the first protrusion 121, the second protrusion 122 and the third protrusion 123 rotationally symmetrical around the center line of the injection hole 14, the injection hole 14 is located at the center position of the first protrusion 121, the second protrusion 122 and the third protrusion 123, which is conducive to setting the injection hole 14 in the central area of ​​the collecting plate 10, so that the injection hole 14 injects liquid into the central part of the wound electrode assembly. At the same time, the thickness of the first protrusion 121, the second protrusion 122 and the third protrusion 123 makes the injection hole 14 have a certain length, which provides a certain buffer space for the flow of electrolyte injected into the injection hole 14, so that the electrolyte can be injected into the injection hole 14 at a large flow rate and high speed, reducing the probability of local overflow and splashing of the electrolyte, and improving the safety of the secondary battery production process.

[0118] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 4 and Figure 5The boss 13 is rotationally symmetrical around the center line of the injection hole 14, so that the injection hole 14 is located in the central area of ​​the boss 13, that is, there is a spacing distance between the injection hole 14 and the outer peripheral surface of the boss 13. When the cover plate 20 is connected to the convex portion 12, there is a spacing distance between the outer peripheral surface of the boss 13 and the welding connection between the cover plate 20 and the convex portion 12, so that there is a spacing distance between the injection hole 14 and the welding connection between the cover plate 20 and the convex portion 12, which is beneficial to prevent welding slag generated when the cover plate 20 and the convex portion 12 are welded into the injection hole 14 at the boss 13.

[0119] Optionally, the boss 13 is cylindrical; or, the boss 13 is frustum-shaped, and the area of ​​the surface of the boss 13 facing the convex portion 12 is larger than the area of ​​the surface of the boss 13 facing away from the convex portion 12 .

[0120] By making the boss 13 rotationally symmetrical around the center line of the injection hole 14, the injection hole 14 is located in the central area of ​​the boss 13, and there is a spacing distance between the injection hole 14 and the outer peripheral surface of the boss 13. When the cover plate 20 is connected to the convex portion 12, there is a spacing distance between the injection hole 14 and the welding connection between the cover plate 20 and the convex portion 12. This is beneficial to prevent welding slag generated when welding the cover plate 20 and the convex portion 12 from falling into the injection hole 14 at the boss 13, thereby improving the safety of the secondary battery production process.

[0121] In one embodiment, please refer to Figure 6 、 Figure 7 、 Figure 8 and Figure 9 A groove 131 is provided on the surface of the boss 13 facing away from the convex portion 12, and the bottom wall of the groove 131 is lower than the surface of the boss 13 facing away from the convex portion 12. There is a spacing distance between the side wall of the groove 131 and the outer peripheral surface of the boss 13, so that the boss 13 surrounds the bottom wall of the groove 131, and the injection hole 14 passes through the bottom wall of the groove 131 and the second surface 112, and the size of the injection hole 14 is smaller than the size of the bottom wall of the groove 131, so that the boss 13 surrounds the injection hole 14. When the electrolyte is injected from the injection hole 14, the groove 131 can accommodate part of the electrolyte that has not flowed smoothly into the injection hole 14, thereby preventing the electrolyte from contaminating the surface of the boss 13 facing away from the convex portion 12 and affecting the subsequent sealing process of the injection hole 14. The groove 131 also provides a certain buffer space for the flow of the electrolyte, so that the electrolyte can be injected with a large flow rate and high speed.

[0122] At the same time, the opening size of the injection hole 14 is appropriate, which avoids the opening size of the injection hole 14 being too small, affecting the injection efficiency of the electrolyte, or the opening size of the injection hole 14 being too large, resulting in excessive electrolyte injection flow, increasing the probability of electrolyte overflow and splashing, and affecting the electrolyte infiltration of the wound electrode assembly. The appropriate opening size also makes the sealing of the injection hole 14 simpler, which is beneficial to improving the sealing performance at the injection hole 14 and improving the performance of the secondary battery.

[0123] Optionally, the injection hole 14 is located in the central area of ​​the bottom wall of the groove 131, so that there is a spacing distance between the injection hole 14 and the outer peripheral surface of the boss 13. When the cover plate 20 is welded to the protrusion 12 of the collecting plate 10, the welding area and the injection hole 14 are spaced apart, and a boss 13 is also provided between the welding area and the injection hole 14 to block it, which is beneficial for the boss 13 to protect the injection hole 14 and prevent welding slag from falling into the injection hole 14 and entering the interior of the battery.

[0124] Optionally, the injection hole 14 is circular, the bottom wall and opening of the groove 131 are both circular, and the side walls of the protrusion 12 and the groove 131 are rotationally symmetrical around the center line of the injection hole 14, which is conducive to simplifying the production and manufacturing process of the protrusion 12 and the groove 131, making the opening position of the injection hole 14 easier to locate, thereby improving the production yield of the collecting plate 10.

[0125] Optionally, the groove 131 has vertical side walls, and the opening size of the groove 131 is equal to the size of the bottom wall of the groove 131, which is conducive to simplifying the opening of the groove 131, increasing the volume of the groove 131 for holding the electrolyte, and improving the safety of the injection hole 14 during the injection process; or, the groove 131 has inclined side walls, and the opening size of the groove 131 is larger than the size of the bottom wall of the groove 131, which is conducive to simplifying the opening of the groove 131. The inclined side walls are also conducive to the electrolyte attached to the side walls flowing into the injection hole 14, improving the safety when sealing the injection hole 14. At the same time, it is also conducive to simplifying the sealing steps at the injection hole 14 and improving the sealing performance of the injection hole 14.

[0126] When manufacturing the collecting tray 10, the protrusion 12 can be first formed on the main body 11, the boss 13 can then be connected to the surface of the protrusion 12 facing away from the main body 11, and finally the groove 131 can be defined on the surface of the boss 13 facing away from the protrusion 12. Alternatively, after the protrusion 12 is formed on the main body 11, the annular boss 13 can be connected to the surface of the protrusion 12 facing away from the main body 11, so that the inner sidewall of the annular boss 13 and the surface of the protrusion 12 facing away from the main body 11 form the groove 131. Optionally, the surface of the protrusion 12 facing away from the main body 11 is flush with the bottom wall of the groove 131. In this case, the groove 131 can be defined by the boss 13 or by the annular boss 13 and the protrusion 12. Alternatively, the surface of the protrusion 12 facing away from the main body 11 is lower than the bottom wall of the groove 131. In this case, the boss 13 defines the groove 131. Alternatively, the surface of the protrusion 12 facing away from the main body 11 is lower than the bottom wall of the groove 131. In this case, the boss 13 defines the groove 131. Alternatively, the surface of the protrusion 12 facing away from the main body 11 is higher than the bottom wall of the groove 131. In this case, the boss 13 defines the groove 131.

[0127] By providing a groove 131 on the surface of the boss 13 facing away from the convex portion 12, the injection hole 14 passes through the bottom wall of the groove 131 and the second surface 112, so that the boss 13 surrounds the injection hole 14. When the electrolyte is injected from the injection hole 14, the groove 131 can accommodate part of the electrolyte that has not flowed smoothly into the injection hole 14, providing a certain buffer space for the flow of the electrolyte, so that the electrolyte can be injected at a large flow rate and high speed, which is beneficial to improving the injection efficiency of the electrolyte. At the same time, the boss 13 has a certain height, so that the groove 131 has a certain depth, which is beneficial to avoid the electrolyte contaminating the surface of the boss 13 facing away from the convex portion 12, affecting the subsequent sealing process of the injection hole 14, and improving the safety of the sealing process of the injection hole 14. Furthermore, the boss 13 surrounds and protects the injection hole 14. When the cover plate 20 is welded to the collecting plate 10, welding slag is prevented from falling from the injection hole 14 into the interior of the battery, causing a safety hazard of short circuit.

[0128] In one embodiment, please refer to Figure 6 、 Figure 7 、 Figure 8 and Figure 9 The maximum radius of the injection hole 14 is smaller than the minimum radius of the bottom wall of the groove 131 , so that the area of ​​the bottom wall of the groove 131 is larger than the area of ​​the injection hole 14 .

[0129] By making the maximum radius of the injection hole 14 smaller than the minimum radius of the bottom wall of the groove 131, it is beneficial to reasonably reduce the area of ​​the injection hole 14 and reduce the probability of welding slag falling into the battery from the injection hole 14. At the same time, the electrolyte holding capacity of the groove 131 is increased, and the buffering capacity of the groove 131 for the electrolyte is improved.

[0130] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 4 、 Figure 5 、 Figure 10 and Figure 11 The height of the protrusion 12 protruding from the bottom wall of the groove 24 is the same as the height of the bottom wall of the groove 24, that is, the protrusion 12 does not protrude from the bottom wall of the groove 24, and there is only the boss 13 in the groove 24 protruding from the bottom wall of the groove 24, and at the connection between the inner wall of the assembly hole 23 and the protrusion 12, there is no height difference between the bottom wall of the groove 24 and the surface of the protrusion 12 facing away from the main body 11, which is conducive to enhancing the sealing performance of the connection between the assembly hole 23 and the protrusion 12, that is, enhancing the sealing performance of the connection between the cover plate 20 and the collecting plate 10.

[0131] Optionally, a groove 131 is formed on the surface of the boss 13 facing away from the convex portion 12 , and the injection hole 14 passes through the bottom wall of the groove 131 and the second surface 112 . The bottom wall of the groove 131 is flush with the bottom surface of the sink 24 .

[0132] By making the height of the protrusion 12 protruding from the bottom wall of the groove 24 the same as the height of the bottom wall of the groove 24, there is no height difference between the bottom wall of the groove 24 and the surface of the protrusion 12 facing away from the main body 11 at the connection between the inner wall of the assembly hole 23 and the protrusion 12, which is beneficial to enhancing the sealing of the connection between the assembly hole 23 and the protrusion 12, that is, enhancing the sealing of the connection between the cover plate 20 and the collecting plate 10.

[0133] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 4 、 Figure 5 、 Figure 14 and Figure 15 The end cover assembly 101 further includes a cover plate 30 , which is welded to the boss 13 and closes the liquid injection hole 14 .

[0134] When the injection hole 14 passes through the surface of the boss 13 facing away from the convex portion 12 and the second surface 112, optionally, the area of ​​the cover plate 30 is slightly larger than the area of ​​the injection hole 14 and smaller than the area of ​​the surface of the boss 13 facing away from the convex portion 12. After the cover plate 20 closes the injection hole 14, the cover plate 20 is welded to the surface of the boss 13 facing away from the convex portion 12 to achieve sealing of the injection hole 14; or, the cover plate 30 includes a top plate 31 and a sealing plug, the top plate 31 is connected to the sealing plug, the sealing plug corresponds to the size of the injection hole 14, the sealing plug is inserted into the injection hole 14 to achieve sealing of the injection hole 14, and the top plate 31 is in close contact with and connected to the surface of the boss 13 facing away from the convex portion 12.

[0135] When a groove 131 is provided on the surface of the boss 13 facing away from the convex portion 12, and the liquid injection hole 14 passes through the bottom wall of the groove 131 and the second surface 112, the area of ​​the cover sheet 30 is slightly larger than the area of ​​the liquid injection hole 14 and smaller than the area of ​​the bottom wall of the groove 131. After the cover plate 20 closes the liquid injection hole 14, the cover plate 20 is at least partially accommodated in the groove 131, and the cover plate 20 is welded to the bottom wall of the groove 131 to achieve sealing of the liquid injection hole 14; or, the cover sheet 30 includes a top sheet 31 and a sealing plug, the top sheet 31 is at least partially accommodated in the groove 131, and the top sheet 31 is in close contact with and connected to the bottom wall of the groove 131; or, the area of ​​the cover sheet 30 is slightly larger than the area of ​​the opening of the groove 131 and smaller than the area of ​​the surface of the boss 13 facing away from the convex portion 12, the cover plate 20 simultaneously closes the groove 131 and the liquid injection hole 14, and after the cover plate 20 closes the groove 131, the cover plate 20 is connected to the surface of the boss 13 facing away from the convex portion 12.

[0136] By making the end cap assembly 101 also include a cover plate 30, the cover plate 30 is welded to the boss 13 and closes the injection hole 14, which is conducive to sealing the injection hole 14 after the electrolyte is injected from the injection hole 14, avoiding leakage of the electrolyte from the injection hole 14, and ensuring the safety and stability of the secondary battery during use.

[0137] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 4 、 Figure 5 、 Figure 10 and Figure 14 The height of the cover plate 30 relative to the bottom wall of the sink 24 is less than the depth of the sink 24 .

[0138] When the injection hole 14 passes through the surface of the boss 13 facing away from the convex portion 12 and the second surface 112, the cover piece 30 is in close contact with the surface of the boss 13 facing away from the convex portion 12. The height of the cover piece 30 protruding from the bottom wall of the groove 24 is greater than the height of the boss 13 protruding from the bottom wall of the groove 24. The maximum height at the boss 13 is the height at which the cover piece 30 is provided. The thickness of the cover piece 30 needs to be controlled to avoid the height of the cover plate 20 being higher than the depth of the groove 24.

[0139] When the surface of the boss 13 facing away from the convex portion 12 is provided with a groove 131, and the injection hole 14 passes through the bottom wall of the groove 131 and the second surface 112, when the cover piece 30 is connected to the bottom wall of the groove 131, the cover piece 30 can be accommodated in the groove 131 as a whole, and the height of the cover piece 30 relative to the bottom wall of the sink 24 is lower than the height of the boss 13 protruding from the bottom wall of the sink 24. The maximum height at the boss 13 is the height of the boss 13 itself. It is necessary to control the height of the boss 13 to avoid the height of the boss 13 being higher than the depth of the sink 24; when the cover piece 30 is connected to the surface of the boss 13 facing away from the convex portion 12, the height of the cover piece 30 protruding from the bottom wall of the sink 24 is greater than the height of the boss 13 protruding from the bottom wall of the sink 24. It is necessary to control the thickness of the cover piece 30 to avoid the height of the cover plate 20 being higher than the depth of the sink 24.

[0140] By making the height of the cover piece 30 relative to the bottom wall of the recess 24 smaller than the depth of the recess 24, the recess 24 accommodates the boss 13 and the cover piece 30, which is beneficial for the recess 24 to protect the boss 13 and the cover piece 30, and prevents the cover piece 30 from protruding from the third surface 21, causing interference with the bottom plate of the module during module assembly. At the same time, it is also beneficial to ensure the sealing performance of the cover piece 30 on the injection hole 14, and avoid collision between the cover piece 30 and the bottom plate of the module, resulting in structural deformation of the cover piece 30, which in turn affects the sealing performance of the cover piece 30 on the injection hole 14.

[0141] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 4 、 Figure 5 、 Figure 14 and Figure 15 The boss 13 is cylindrical, and the cover 30 includes a top sheet 31 and an annular sleeve 32. The top sheet 31 is connected to one end of the annular sleeve 32. The annular sleeve 32 is sleeved on the outer periphery of the boss 13. The top sheet 31 is covered on the surface of the boss 13 facing away from the convex portion 12.

[0142] Alternatively, the inner wall of the annular sleeve 32 contacts the outer peripheral surface of the boss 13, and at this time, there may be a spacing distance between the surface of the annular sleeve 32 facing away from the top sheet 31 and the surface of the protrusion 12 facing away from the main body 11, and the cover sheet 30 is connected to the surface of the protrusion 13 facing away from the protrusion 12, or the cover sheet 30 is connected to the outer peripheral surface of the boss 13, and the surface of the annular sleeve 32 facing away from the top sheet 31 and the surface of the protrusion 12 facing away from the main body 11 may also contact. In addition to being connected to the boss 13, the cover sheet 30 may also be connected to the surface of the protrusion 12 facing away from the main body 11; or, there is a spacing distance between the inner wall of the annular sleeve 32 and the outer peripheral surface of the boss 13, and at this time, the surface of the annular sleeve 32 facing away from the top sheet 31 may contact the surface of the protrusion 12 facing away from the main body 11, so that the cover sheet 30 is connected to the protrusion 12, and may also contact the surface of the cover plate 20 facing away from the main body 11, so that the cover sheet 30 is connected to the cover plate 20, and it is ensured that the cover sheet 30 has a good sealing effect on the liquid injection hole 14.

[0143] Optionally, the surface of the top sheet 31 facing the boss 13 is flat, and the top sheet 31 is in close contact with the surface of the boss 13 facing away from the convex portion 12; or, the surface of the top sheet 31 facing the boss 13 is provided with an air pressure groove 33, the air pressure groove 33 corresponds to the liquid injection hole 14, and the opening size of the air pressure groove 33 is greater than or equal to the size of the liquid injection hole 14, and is used to provide a certain air pressure balance space when the cover sheet 30 seals the liquid injection hole 14.

[0144] By making the cover sheet 30 include a top sheet 31 and an annular sleeve 32, the top sheet 31 is connected to one end of the annular sleeve 32, the annular sleeve 32 is sleeved on the outer periphery of the boss 13, and the top sheet 31 is covered on the surface of the boss 13 facing away from the convex portion 12, so that the cover sheet 30 is sleeved on the outer periphery of the boss 13, which is beneficial to improving the sealing ability of the cover sheet 30 on the injection hole 14. At the same time, the contact area between the cover sheet 30 and the boss 13 is increased. Changing the structure and size of the annular sleeve 32 can also realize the connection between the cover sheet 30 and the boss 13, the convex portion 12 or the cover plate 20, which is beneficial to simplify the connection between the cover sheet 30 and the collecting tray 10 or the cover plate 20 and improve the stability of the connection between the cover sheet 30 and the collecting tray 10 or the cover plate 20.

[0145] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 4 、 Figure 14 and Figure 15 The cover plate 20 is welded to the collecting plate 10 to form a welding ring. The welding ring is located on the outer peripheral surface of the protrusion 12. The orthographic projection of the annular sleeve 32 on the main body 11 and the orthographic projection of the welding ring on the main body 11 have a preset distance. The annular sleeve 32 is welded to the bottom wall of the sink 24.

[0146] Optionally, the annular sleeve 32 is welded and fixed to the surface of the protrusion 12 facing away from the main body 11, and the welding position of the annular sleeve 32 and the surface of the protrusion 12 facing away from the main body 11 has a preset distance from the welding ring. At this time, the welding position of the annular sleeve 32 is close to the welding ring, and the heat generated by the welding can also reheat the welding ring to form a tempering effect.

[0147] Optionally, there is a spacing distance between the annular sleeve 32 and the side wall of the sink 24 .

[0148] The cover plate 20 is welded to the collecting plate 10 to form a welding ring, the welding ring is located on the outer peripheral surface of the protrusion 12, and the orthographic projection of the annular sleeve 32 on the main body 11 and the orthographic projection of the welding ring on the main body 11 have a preset distance, and the annular sleeve 32 is welded to the bottom wall of the sink 24. When the cover plate 30 is welded to the bottom wall of the sink 24, the heat generated by the welding can heat the welding ring again to form a tempering effect, which is beneficial to eliminate the stress generated by the welding of the cover plate 20 and the collecting plate 10, and improve the sealing performance of the welded connection between the cover plate 20 and the collecting plate 10. At the same time, the welding ring is located on the inner side of the annular sleeve 32, and the cover plate 30 not only seals the injection hole 14, but also seals the welding ring where the cover plate 20 is connected to the collecting plate 10, which is beneficial to further improve the sealing performance of the welded connection between the cover plate 20 and the collecting plate 10.

[0149] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 4 、 Figure 14 and Figure 15 The welding ring is connected to the annular sleeve 32 , the protrusion 12 and the cover plate 20 , so that the annular sleeve 32 , the protrusion 12 and the cover plate 20 are welded and fixed at one time through the welding ring, which is conducive to simplifying the welding and sealing method of the end cover assembly 101 .

[0150] In one embodiment, please refer to Figure 2 、 Figure 3A 、 Figure 4 、 Figure 14 and Figure 15 The preset distance between the orthographic projection of the annular sleeve 32 on the main body 11 and the orthographic projection of the welding ring on the main body 11 is 1 mm to 4 mm.

[0151] By setting the preset distance between the orthographic projection of the annular sleeve 32 on the main body 11 and the orthographic projection of the welding ring on the main body 11 to 1 mm to 4 mm, it is beneficial to ensure that the welding position of the annular sleeve 32 and the bottom wall of the sink 24 is close to the welding ring, which facilitates the reheating of the welding ring. At the same time, it also avoids the welding position of the annular sleeve 32 and the bottom wall of the sink 24 being too close to the welding ring, resulting in affecting the stability of the welding connection between the cover plate 20 and the collecting plate 10 during the welding process of the annular sleeve 32 and the bottom wall of the sink 24.

[0152] In one embodiment, please refer to Figure 6 、 Figure 7 、 Figure 10 、 Figure 12 and Figure 13 A groove 131 is formed on the surface of the boss 13 facing away from the convex portion 12 , and the cover 30 is received in the groove 131 and connected to the inner wall of the groove 131 .

[0153] Optionally, the surface of the cover sheet 30 facing the bottom wall of the groove 131 contacts the bottom wall of the groove 131, in which case the cover sheet 30 can be connected to the side wall of the groove 131 or to the bottom wall of the groove 131; or, there is a spacing distance between the surface of the cover sheet 30 facing the bottom wall of the groove 131 and the bottom wall of the groove 131, in which case the cover sheet 30 is connected to the side wall of the groove 131.

[0154] Optionally, an air pressure groove 33 is provided on the surface of the cover plate 30 facing the bottom wall of the groove 131, and the air pressure groove 33 corresponds to the liquid injection hole 14. The area of ​​the opening of the air pressure groove 33 is larger than the area of ​​the bottom wall of the air pressure groove 33, and the side wall of the air pressure groove 33 is inclined. The area of ​​the opening of the air pressure groove 33 can be larger than the area of ​​the liquid injection hole 14, or can be equal to the area of ​​the liquid injection hole 14. There is a spacing distance between the bottom wall of the air pressure groove 33 and the surface of the cover plate 30 facing away from the bottom wall of the groove 131.

[0155] Optionally, the surface of the cover plate 30 away from the bottom wall of the groove 131 is flush with the surface of the boss 13 facing away from the convex portion 12. At this time, the height of the cover plate 30 is the same as the height of the boss 13. The height of the boss 13 is lower than the depth of the groove 24, and the height of the cover plate 30 is also lower than the depth of the groove 24.

[0156] By providing a groove 131 on the surface of the boss 13 facing away from the convex portion 12, the cover sheet 30 is accommodated in the groove 131 and connected to the inner wall of the groove 131, thereby reducing the setting height of the cover sheet 30, which helps to prevent the cover sheet 30 from protruding from the third surface 21 and causing interference with the bottom plate of the module during module assembly. At the same time, it helps to ensure the sealing performance of the cover sheet 30 on the injection hole 14, avoid collision between the cover sheet 30 and the bottom plate of the module, resulting in structural deformation of the cover sheet 30, and further affecting the sealing performance of the cover sheet 30 on the injection hole 14.

[0157] This application also provides an energy storage device 100, please refer to Figure 6 、 Figure 7 and Figure 16 The energy storage device 100 includes an electrode assembly, a shell 102 and an end cap assembly 101 described in any of the above embodiments. The electrode assembly is disposed in the shell 102, the end cap assembly 101 is electrically connected to the electrode assembly, and the end cap assembly 101 is connected to the shell 102 and seals the shell 102.

[0158] It can be understood that the energy storage device 100 in this embodiment has the end cover assembly 101 in the above embodiment. Therefore, the energy storage device 100 in this embodiment has all the technical effects of the end cover assembly 101 in the above embodiment. Since the technical effects of the end cover assembly 101 have been fully described in the above embodiment, they will not be repeated here.

[0159] This application also provides an electrical device 300, please refer to Figure 16 The electrical equipment 300 includes the energy storage device 100 described in the above embodiment, and the energy storage device 100 is used to supply power to the electrical equipment 300.

[0160] It can be understood that the electrical equipment 300 in this embodiment has the energy storage device 100 in the above embodiment. Therefore, the electrical equipment 300 in this embodiment has all the technical effects of the energy storage device 100 in the above embodiment. Since the technical effects of the energy storage device 100 have been fully described in the above embodiment, they will not be repeated here.

[0161] In the description of the embodiments of the present application, it should be noted that the orientation or positional relationship of terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", and "outside" are based on the orientation or positional relationship described in the accompanying drawings. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present application.

[0162] The above disclosure is only a preferred embodiment of the present application, and certainly cannot be used to limit the scope of the claims of the present application. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made in accordance with the claims of the present application are still within the scope covered by the present application.

Claims

1. An end cap assembly, characterized in that: include: A current collecting tray comprises a main body, a convex portion, and a boss, wherein the main body comprises a first surface and a second surface opposite to each other, the convex portion is arranged on the first surface, the boss is arranged on the surface of the convex portion facing away from the main body, and the current collecting tray is provided with a liquid injection hole, the liquid injection hole passing through the side of the boss facing away from the convex portion and the second surface; The cover plate includes a third surface and a fourth surface facing each other, the fourth surface facing the collecting plate, a sink groove formed on the third surface, and an assembly hole formed on the cover plate. The assembly hole passes through the bottom wall of the sink groove and the fourth surface, the assembly hole is welded to the protrusion, the boss protrudes from the bottom wall of the sink groove, and the height of the boss protruding from the bottom wall of the sink groove is less than the depth of the sink groove; The orthographic projection area of ​​the boss on the main body is smaller than the orthographic projection area of ​​the end of the convex portion away from the main body on the main body, and the outer peripheral surface of the boss is spaced apart from the connection between the cover plate and the end of the convex portion away from the main body.

2. The end cap assembly according to claim 1, wherein: The inner wall of the assembly hole is in close contact with the side wall of the protrusion.

3. The end cap assembly according to claim 2, wherein: The protrusion includes a first protrusion and a second protrusion, the first protrusion is connected to the main body, the second protrusion is connected to the side of the first protrusion facing away from the main body, the orthographic projection area of ​​the second protrusion on the main body is smaller than the orthographic projection area of ​​the first protrusion on the main body, and the orthographic projection of the second protrusion completely falls within the orthographic projection range of the first protrusion, the inner wall of the assembly hole is in close contact with the side wall of the second protrusion, and the boss is arranged on the side of the second protrusion facing away from the first protrusion.

4. The end cap assembly according to claim 3, wherein: The maximum radius of the second protrusion is smaller than the minimum radius of the first protrusion.

5. The end cap assembly according to claim 3, wherein: The protrusion also includes a third protrusion, which is connected to the side of the second protrusion facing away from the first protrusion. The orthographic projection area of ​​the third protrusion on the main body is smaller than the orthographic projection area of ​​the second protrusion on the main body. The inner wall of the assembly hole is in close contact with the side walls of the second protrusion and the third protrusion, and the boss is arranged on the side of the third protrusion facing away from the second protrusion.

6. The end cap assembly according to claim 5, wherein: The maximum radius of the boss is smaller than the minimum radius of the third protrusion.

7. The end cap assembly according to claim 5, wherein: The first protrusion and the third protrusion are both cylindrical, the second protrusion is truncated cone-shaped, and the maximum radius of the third protrusion is equal to the minimum radius of the second protrusion.

8. The end cap assembly according to claim 7, wherein: The first protrusion, the second protrusion, and the third protrusion are all rotationally symmetrical around a center line of the liquid injection hole.

9. The end cap assembly according to claim 1, wherein: The boss is rotationally symmetrical around the center line of the liquid injection hole.

10. The end cap assembly according to claim 1, wherein: A groove is formed on the surface of the boss facing away from the convex portion, and the injection hole passes through the bottom wall of the groove and the second surface, so that the boss surrounds the injection hole.

11. The end cap assembly according to claim 10, wherein: The maximum radius of the liquid injection hole is smaller than the minimum radius of the bottom wall of the groove.

12. The end cap assembly according to claim 1, wherein: There is no height difference between the bottom wall of the sink and the surface of the protrusion facing away from the main body.

13. The end cap assembly according to claim 1, wherein: The end cover assembly further comprises a cover plate, which is welded to the boss and closes the liquid injection hole.

14. The end cap assembly according to claim 13, wherein: The height of the cover relative to the bottom wall of the sink is smaller than the depth of the sink.

15. The end cap assembly according to claim 14, wherein: The cover plate includes a top plate and an annular sleeve, wherein the top plate is connected to one end of the annular sleeve, the annular sleeve is sleeved on the outer periphery of the boss, and the top plate is covered on the surface of the boss facing away from the convex portion.

16. The end cap assembly according to claim 15, wherein: The cover plate is welded to the collecting plate to form a welding ring, the welding ring is located on the outer peripheral surface of the protrusion, the orthographic projection of the annular sleeve on the main body and the orthographic projection of the welding ring on the main body have a preset distance, and the annular sleeve is welded to the bottom wall of the sink.

17. The end cap assembly according to claim 16, wherein: The welding ring is connected to the annular sleeve, the protrusion and the cover plate.

18. The end cap assembly according to claim 16, wherein: The preset distance is 1 mm to 4 mm.

19. An energy storage device, characterized in that: The energy storage device includes an electrode assembly, a shell, and an end cap assembly according to any one of claims 1 to 18, wherein the electrode assembly is disposed in the shell, the end cap assembly is electrically connected to the electrode assembly, and the end cap assembly is connected to the shell and seals the shell.

20. An electrical device, characterized in that: The electrical equipment includes the energy storage device according to claim 19, and the energy storage device is used to supply power to the electrical equipment.

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