End cover assembly, energy storage device and electric equipment

Abstract

The invention discloses an end cover assembly, an energy storage device and electric equipment, the end cover assembly comprises an end cover, upper plastic and a pole, the end cover comprises an end cover body, the end cover body comprises a first surface, an inclined boss and a through hole, the inclined boss is arranged on the first surface in a protruding mode, the inclined boss comprises an inclined circumferential surface and a boss surface, the inclined circumferential surface is connected with the boss surface and the first surface, and the through hole is formed in the inclined circumferential surface. The periphery of the boss surface is surrounded; the upper plastic comprises a body section, an extending section and a protruding section, the body section is connected with the periphery of the extending section, the extending section extends in the height direction of the upper plastic, the extending direction of the body section intersects with the extending direction of the extending section, the protruding section extends from the periphery, away from the extending section, of the body section, and the extending direction is the same as the extending direction of the body section. The pole comprises a flange; the upper plastic and the pole are arranged on the end cover; the body section is positioned between the flange and the inclined boss; the end, away from the through hole, of the protruding section protrudes out of the inclined circumferential face and the outer circumferential edge of the flange in the direction, away from the axis of the through hole, of the protruding section and is spaced from the first surface.

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] A secondary battery (rechargeable battery), also known as a rechargeable battery or storage battery, refers to a battery that can be recharged to activate the active material and continue to be used after the battery is discharged. The recyclable nature of secondary batteries has made them gradually become the main power source for electrical equipment. Among them, secondary batteries use electrolytes. During the formation of the battery, if the electrolyte splashes near the pole, it is easy to penetrate into the battery from the gap between the upper plastic and the top cover, and stay for a long time. The electrolyte will corrode the sealing ring in the end cover, causing the seal to fail; and the electrolyte may form white crystals due to oxidation or drying, destroying the uniformity of the force on the inside of the sealing ring, causing the seal to fail. Summary of the invention

[0003] The present application provides an end cover assembly, an energy storage device and an electrical device, which can prevent the electrolyte from entering the interior of the battery from between the upper plastic and the top cover and affecting the sealing ring, thereby ensuring the sealing performance of the sealing ring.

[0004] In a first aspect, the present application provides an end cover assembly, comprising: an end cover, comprising an end cover body, the end cover body comprising a first surface, a second surface and an inclined boss, the first surface and the second surface are arranged opposite to each other along the thickness direction of the end cover body, the inclined boss is protruded from the first surface of the end cover body, the inclined boss comprises an inclined circumferential surface and a boss surface, the inclined circumferential surface connects the boss surface and the first surface and surrounds the periphery of the boss surface, the end cover body also comprises a through hole penetrating the second surface and the first surface and the second surface of the boss surface.

[0005] The upper plastic comprises a main body section, an extension section and a protruding section, the main body section is connected to the outer periphery of the extension section, the extension section extends along the height direction of the upper plastic, the extension direction of the main body section intersects with the extension direction of the extension section, the extension section forms an insulating hole, and the protruding section extends from the main body section away from the outer periphery of the extension section, and the extension direction is the same as the extension direction of the main body section.

[0006] The pole comprises a flange and a main body, the flange comprises a top surface and a bottom surface, the top surface and the bottom surface are arranged opposite to each other along the thickness direction of the flange, and the main body is protruded from the bottom surface and extends in a direction away from the flange.

[0007] The upper plastic and the pole are mounted on the end cover, the extension section is passed through the through hole, the main body is passed through the insulating hole and the through hole in sequence, and along the axial direction of the through hole, the main body section is located between the bottom surface of the flange and the inclined boss of the end cover body. Along the direction in which the protruding section is away from the axis of the through hole, one end of the protruding section away from the through hole protrudes from the inclined boss of the inclined peripheral surface and the outer periphery of the flange, and the protruding section is spaced apart from the first surface of the end cover body.

[0008] In one embodiment, the protruding section includes an upper curved surface, the upper curved surface faces away from the end cover, and the upper curved surface is arranged at an angle with the first surface of the end cover.

[0009] In one embodiment, the inclined boss includes an inclined peripheral surface and a boss surface, the inclined peripheral surface connects the boss surface and the first surface and surrounds the periphery of the boss surface, and the through hole penetrates the second surface and the boss surface.

[0010] The protruding section also includes a lower arc surface, which is arranged opposite to the upper arc surface along the thickness direction of the protruding section. The lower arc surface and the inclined peripheral surface form an annular notch with a "<" shape in cross section, and the notch surrounds and faces away from the pole.

[0011] In one embodiment, the main body segment includes an upper portion and a lower portion, the upper portion and the lower portion are arranged opposite to each other along the thickness direction of the main body segment, the upper portion is opposite to and connected to the bottom surface, and the upper portion and the bottom surface are both parallel to the first surface, and the lower portion is opposite to and connected to the boss surface, and the lower portion and the boss surface are both parallel to the first surface.

[0012] The width of the upper surface is smaller than the width of the lower surface, the width of the upper curved surface is larger than the width of the lower curved surface, and the angle at which the upper curved surface is inclined relative to the upper surface is smaller than the angle at which the lower curved surface is inclined relative to the lower surface.

[0013] In one embodiment, the end cover assembly also includes an explosion-proof valve, and the end cover also includes an inner recess and a reinforcing protrusion, the inner recess is formed by the second surface being recessed in the direction of the first surface, and the reinforcing protrusion is formed on the first surface, and the reinforcing protrusion protrudes out of the first surface.

[0014] The end cover also includes a pressure relief hole, which runs through the reinforcing convex portion along the thickness direction of the end cover. Part of the explosion-proof valve is arranged on the end cover and covers the pressure relief hole.

[0015] In one embodiment, the end cover assembly further includes a lower plastic, and the lower plastic and the end cover are stacked along the thickness direction of the end cover assembly.

[0016] The end cover also includes a first annular groove and a second annular groove, the first annular groove is located in the inner recess, the second annular groove is recessed in the reinforcing protrusion, the first annular groove and the second annular groove are both arranged around the periphery of the pressure relief hole and are both connected to the hole wall of the pressure relief hole.

[0017] The explosion-proof valve includes an explosion-proof valve plate, a protective plate and an explosion-proof fence. The explosion-proof valve plate is accommodated in the second annular groove, the protective plate is accommodated in the first annular groove, the protective plate and the explosion-proof valve plate are opposite and spaced apart along the thickness direction of the end cover assembly, the explosion-proof fence is arranged on the lower plastic, and the explosion-proof valve plate is located in the explosion-proof fence.

[0018] In one embodiment, the end cover assembly further includes an explosion-proof valve, which includes an explosion-proof valve plate, a protective plate and an explosion-proof fence, wherein the explosion-proof fence is disposed on the lower plastic, and the end cover further includes a pressure relief hole, which is opposite to the explosion-proof fence along the thickness direction of the end cover assembly.

[0019] The end cover also includes a plurality of reinforcing recesses and a plurality of inner convex bumps, each of the reinforcing recesses is recessed on the first surface and is recessed toward the second surface to form an inner convex bump, a plurality of the inner convex bumps are all convexly disposed on the second surface, a plurality of the reinforcing recesses are arranged in parallel along the length direction of the end cover and are arranged at intervals along the width direction of the end cover, and a plurality of the reinforcing recesses are respectively disposed on both sides of the pressure relief hole along the width direction of the end cover.

[0020] The extension direction of the reinforced recess is consistent with the length direction of the end cover, and the length of the reinforced recess is greater than the width of the explosion-proof valve fence.

[0021] In one embodiment, the lower plastic also includes a plurality of avoidance portions, which are recessed in the first surface and recessed toward the second surface. The plurality of avoidance portions are arranged in parallel along the length direction of the lower plastic and are arranged at intervals along the width direction of the lower plastic. The plurality of avoidance portions all cross the explosion-proof fence and are connected to the explosion-proof fence, and each of the inner convexities is contained in one of the avoidance portions.

[0022] In one embodiment, the flange is an elliptical block, the main body is an elliptical cylinder, and the through hole is an elliptical hole.

[0023] In a second aspect, the present application provides an energy storage device, which, in addition to the end cover assembly, further includes: a housing, wherein the housing includes an opening.

[0024] The electrode assembly comprises a battery cell, wherein the battery cell comprises a battery cell body and a tab, wherein the battery cell body comprises an upper end face and a lower end face, wherein the upper end face and the lower end face are arranged opposite to each other along the height direction of the battery cell body, and the tab extends out of the upper end face. And a connecting piece.

[0025] The end cap assembly is mounted on one end of the electrode assembly facing the opening and sealed at the opening. The connecting piece is located between the electrode assembly and the lower plastic. The connecting piece connects and conducts the pole and the pole ear.

[0026] In a third aspect, the present application provides an electrical device, wherein the electrical device comprises the energy storage device, and the energy storage device is used to supply power to the electrical device.

[0027] The inventor has found through research that when electrolyte penetrates from the outside of the energy storage device through the assembly gap between the end cap and the upper plastic into the energy storage device and stays there for a long time, the electrolyte will corrode the sealing ring in the end cap assembly and cause the seal to fail. At the same time, the residual electrolyte is prone to form white crystals due to oxidation or drying, which not only destroys the uniformity of the force on the inside of the sealing ring, thereby causing the seal to fail, but also remains in the assembly gap between the end cap and the upper plastic, affecting the appearance and performance of the energy storage device.

[0028] In the embodiment of the present application, along the direction of the protruding section away from the axis of the through hole, the protruding section protrudes from the outer periphery of the inclined boss of the end cover, so that the electrolyte that slides off the upper plastic will not penetrate into the energy storage device from the assembly gap between the upper plastic and the end cover, preventing the electrolyte from affecting the sealing ring and ensuring the sealing performance of the sealing ring. At the same time, the protruding section can block the assembly gap between the end cover and the upper plastic, thereby blocking the white crystals formed at the assembly gap between the end cover and the upper plastic, reducing the defect rate of the appearance of the energy storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is an application scenario diagram of the energy storage device provided in the embodiment of the present application;

[0030] Figure 2 A schematic diagram of the structure of the energy storage device provided in the embodiment of the present application;

[0031] Figure 3 for Figure 2 A schematic diagram of the exploded structure of the energy storage device shown;

[0032] Figure 4 for Figure 3 A schematic cross-sectional structure diagram of a first connecting member and a second connecting member in the energy storage device shown;

[0033] Figure 5 for Figure 3 The schematic diagram of the exploded structure of the first embodiment of the end cover assembly in the energy storage device shown;

[0034] Figure 6 for Figure 5 The end cap assembly is shown as a schematic diagram of an exploded structure at another angle;

[0035] Figure 7 for Figure 5 A schematic cross-sectional view of a partially exploded structure of an end cap assembly shown;

[0036] Figure 8 for Figure 5 A schematic cross-sectional structure diagram of an end cap assembly in an energy storage device shown;

[0037] Fig. 9 for Figure 2 The schematic diagram of the cross-sectional structure of the energy storage device along MM shown;

[0038] Fig.10 for Figure 3 A schematic structural diagram of a second embodiment of an end cover assembly in an energy storage device shown;

[0039] Fig.11 for Fig.10 The schematic diagram of the structure of the end cover assembly shown in another angle;

[0040] Fig.12 for Fig.10 An exploded structural diagram of the end cap assembly shown;

[0041] Fig.13 for Fig.11 An exploded structural diagram of the end cap assembly shown;

[0042] Fig.14 for Fig.12 A schematic diagram of the cross-sectional structure of an end cap in the end cap assembly shown;

[0043] Fig.15 for Fig.14 Another cross-sectional schematic diagram of the end cover is shown.

[0044] The nouns corresponding to the reference numerals in the figures are: energy storage device 1000, housing 200, opening 201, accommodating cavity 202, end cover assembly 100, end cover 10, end cover body 11, first surface 111, second surface 112, first assembly groove 12, second assembly groove 13, first inclined boss 14, first boss surface 141, first inclined peripheral surface 142, second inclined boss 15, second boss surface 151, second inclined peripheral surface 152, pressure relief hole 16, first annular groove 17, second annular groove 18, limiting groove 19, first through hole 1, second through hole 2, inner recess 113, reinforcing protrusion 114, reinforcing recess 115, inner convex package 116, lower plastic 20, lower plastic body 21, upper surface 211, lower surface 212, first assembly protrusion 2 2, first raised surface 221, second assembly protrusion 23, second raised surface 231, first through hole 24, second through hole 25, limit column 26, avoidance portion 27, first pole 30, first body 31, first end surface 311, first flange 32, first top surface 321, first bottom surface 322, first step 33, first step surface 331, first pole through hole 34, first sink 35, second pole 40, second body 41, second end surface 411, second flange 42, second top surface 421, second bottom surface 422, second step 43, second step surface 431, second pole through hole 44, second sink 45, first upper plastic 50, first body section 51, first upper surface 511, first lower surface 512, first protruding section 52, first upper arc surface 521, first lower arc surface 522, first extension section 53, first insulating hole 54, second upper plastic 60, second body section 61, second upper surface 611, second lower surface 612, second protruding section 62, second upper arc surface 621, second lower arc surface 622, second extension section 63, second insulating hole 64, first sealing ring 71, first sealing hole 711, second sealing ring 72, second sealing hole 721, first pressing block 80, first connecting hole 801, second pressing block 81, second connecting hole 811, explosion-proof valve 90, explosion-proof fence 91, explosion-proof valve sheet 92, protective sheet 93, electrode assembly 900, battery cell 910, battery cell body 920, upper end surface 921, lower end surface 922, side surface 923, first electrode Ear 930, second pole ear 940, first connector 300, first connecting portion 360, first connecting outer surface 361, first connecting inner surface 362, first adapter portion 370, first adapter outer surface 371, first adapter inner surface 372, first groove 373, first convex hull 374, first top surface 375, first peripheral surface 376, first bending portion 380, second connector 400, second connecting portion 460, second connecting outer surface 461, second connecting inner surface 462, second adapter portion 470, second adapter outer surface 471, second adapter inner surface 472, second groove 473, second convex hull 474, second top surface 475, second peripheral surface 476, second bending portion 480, insulating film 500, support member 600, outer film 700,Protective element 800, first electric device 3000, second electric device 2000, first electric energy conversion device 4100, second electric energy conversion device 4200, energy storage system 5000. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0046] In this application, unless otherwise specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, they can be fixedly connected, detachably connected, or integrated; they can be mechanically connected, electrically connected, or able to communicate with each other; they can be directly connected, or indirectly connected through an intermediate medium, and they can be internally connected between two elements or the interaction relationship between two elements, unless otherwise specified and limited. And the terms "same", "equal" or "parallel" used in the following text are allowed to have a certain tolerance.

[0047] It should be noted that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include at least one of the features.

[0048] Since the energy people need is highly temporal and spatial, in order to rationally utilize 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. As we all know, the main way to generate green electricity is to develop green energy such as photovoltaics and wind power to replace fossil energy. At present, the generation of green electricity generally relies on photovoltaics, wind power, water potential, etc., while wind and solar energy generally have problems of strong intermittency and large volatility, which will cause instability of the power grid, insufficient electricity during peak hours, too much electricity during low hours, and unstable voltage will also cause damage to electricity. Therefore, it may cause "wind and light abandonment" problems due to insufficient electricity demand or insufficient grid acceptance capacity. To solve these problems, energy storage must be relied on. That is, electrical energy is converted into other forms of energy by physical or chemical means and stored, and energy is converted into electrical energy and released when needed. In simple terms, energy storage is similar to a large "power bank". When photovoltaic and wind energy are sufficient, electrical energy is stored and the stored electricity is released when needed.

[0049] Taking electrochemical energy storage as an example, the present application provides an energy storage device 1000, which has a group of chemical batteries inside. The energy storage device 1000 mainly uses the chemical elements in the chemical batteries as energy storage media. The charging and discharging process is accompanied by chemical reactions or changes in the energy storage media. Simply put, the electricity generated by wind energy and solar energy is stored in chemical batteries. 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.

[0050] At present, energy storage (i.e., energy storage) has a wide range of application scenarios, including (wind and solar) power generation side energy storage, grid side energy storage, base station side energy storage, and user side energy storage. The corresponding types of energy storage devices 1000 include:

[0051] (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, achieve load matching of electric energy in time and space, enhance the ability to absorb renewable energy, and are of great significance in grid system backup, relieving peak load power supply pressure, and peak and frequency regulation;

[0052] (2) Small and medium-sized energy storage cabinets used in industrial and commercial energy storage scenarios (banks, shopping malls, etc.) on the user side mainly operate in the "peak shaving and valley filling" mode. 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.

[0053] It should be noted that the above-mentioned energy storage containers, small and medium-sized energy storage cabinets, household small energy storage boxes and other equipment containing the energy storage device 1000 can be understood as electrical equipment.

[0054] See also Figure 1 , Figure 1 It is an application scenario diagram of the energy storage device provided in the embodiment of the present application.

[0055] The energy storage device 1000 provided in the embodiment of the present application is applied to an energy storage system 5000, which includes a first power conversion device 4100 (photovoltaic panel), a second power conversion device 4200 (wind turbine), a first power user 3000 (grid), a second power user 2000 (base station) and an energy storage device 1000. The energy storage system 5000 also includes an energy storage cabinet, and the energy storage device 1000 is installed in the energy storage cabinet, which can be installed outdoors. Specifically, the first power conversion device 4100 can convert solar energy into electrical energy during the period of low electricity prices, and the energy storage device 1000 is used to store the electrical energy and supply the first power user 3000 or the second power user 2000 during peak electricity consumption, or to supply power when the first power user 3000 or the second power user 2000 is powered off / out of power. The second power conversion device 4200 can convert wind energy into electric energy, and the energy storage device 1000 is used to store the electric energy and supply it to the first power device 3000 or the second power device 2000 during peak power consumption, or to supply power when the first power device 3000 or the second power device 2000 is powered off / out of power. The transmission of electric energy can be carried out using a high-voltage cable.

[0056] It should be noted that the first power-consuming device 3000, the second power-consuming device 2000 and other devices including the energy storage device 1000 can be understood as power-consuming devices. The energy storage device 1000 supplies power to the power-consuming devices.

[0057] There may be multiple energy storage devices 1000, and multiple energy storage devices 1000 are connected in series or in parallel. In this embodiment, "multiple" means two or more.

[0058] It can be understood that the energy storage device 1000 may include but is not limited to single cells, battery modules, battery packs, battery systems, etc. The actual application form of the energy storage device 1000 provided in the embodiment of the present application may be but is not limited to the listed products, and may also be other application forms. For example, the energy storage device 1000 may be a secondary battery such as a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid (or lead storage) battery, a lithium-ion battery, a polymer lithium-ion battery, etc. When the energy storage device 1000 is a single cell, it may be a cylindrical battery, a square battery, or a battery of other shapes. In this embodiment, the energy storage device 1000 is a square battery. Among them, the square battery is a secondary battery.

[0059] The inventor has found through research that, during the process of injecting electrolyte into the energy storage device 1000, it is easy for electrolyte to splash near the pole. For example, when the injection needle moves, the electrolyte remaining on the injection needle will drip near the pole. For example, during the process of forming a solid electrolyte interface membrane (SEI membrane) inside the energy storage device 1000, if the electrolyte injection amount is too full, the bubbles generated will move to the top of the energy storage device 1000 and rupture near the injection hole, and the film electrolyte above the bubbles will be ejected from the injection hole to the vicinity of the pole. If the electrolyte penetrates into the energy storage device 1000 from the gap between the upper plastic and the end cover and stays for a long time, the electrolyte will corrode the sealing ring in the end cover and cause the seal to fail. In addition, the electrolyte may form white crystals due to oxidation or drying, which will destroy the uniformity of force on the inside of the sealing ring and cause the seal to fail.

[0060] The present application provides the energy storage device 1000 described below, which can prevent the electrolyte from entering the battery from between the upper plastic and the top cover and affecting the sealing ring, thereby ensuring the sealing performance of the sealing ring.

[0061] See also Figure 2 and Figure 3 , Figure 2 A schematic diagram of the structure of the energy storage device provided in the embodiment of the present application, Figure 3 for Figure 2 Schematic diagram of the exploded structure of the energy storage device shown.

[0062] For ease of description, the width direction of the energy storage device 1000 is defined as the X-axis direction, the length direction is defined as the Y-axis direction, and the height direction is defined as the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are mutually perpendicular.

[0063] The directional terms such as "upper", "top", "lower", "bottom", "left", and "right" mentioned in the description of the embodiments of the present application are based on the Figure 2 The description of the directions shown does not constitute a limitation on the actual application scenario of the energy storage device 1000. Specifically, the positive direction toward the Z-axis direction is the top of the energy storage device 1000, and the negative direction toward the Z-axis direction is the bottom of the energy storage device 1000. The positive direction toward the X-axis direction is the left side of the energy storage device 1000, and the negative direction toward the X-axis direction is the right side of the energy storage device 1000.

[0064] The energy storage assembly includes an end cap assembly 100, a housing 200, a first connector 300, a second connector 400, an insulating film 500, a support member 600, an outer film 700, a protective member 800 and an electrode assembly 900. The housing 200 has an opening 201 and is provided with a receiving cavity 202. The opening 201 is connected to the receiving cavity 202. The electrode assembly 900, the insulating film 500 and the support member 600 are all received in the receiving cavity 202. The support member 600 is located at the bottom of the electrode assembly 900, which is used to support the electrode assembly 900. The insulating film 500 wraps around and around the bottom of the electrode assembly 900, and separates the support member 600 and the housing 200 from the electrode assembly 900. The end cap assembly 100 is mounted on one end of the electrode assembly 900 facing the opening 201 and is sealed to the opening 201. Along the height direction of the energy storage device 1000 (i.e., the Z-axis direction), the first connector 300 and the second connector 400 both connect the end cap assembly 100 and the electrode assembly 900. Along the length direction of the energy storage device 1000 (i.e., the Y-axis direction), the first connector 300 and the second connector 400 are arranged at intervals. The outer film 700 is located on the side of the outer shell 200 facing away from the electrode assembly 900, and is coated around and on the bottom of the outer shell 200 and the edge of the end cap assembly 100. The protective member 800 is attached to the surface of the end cap assembly 100 facing away from the electrode assembly 900. The electrode assembly 900 includes a plurality of battery cells 910. The plurality of battery cells 910 are arranged side by side along the Y-axis direction and fixedly connected by a plurality of tapes.

[0065] In this embodiment, the housing 200 is an aluminum housing structure. The housing 200 is rectangular in shape. The protective member 800 and the support member 600 are both rectangular sheets. There are two battery cells 910. The first connector 300 and the second connector 400 both connect the two battery cells 910 and make the two battery cells 910 electrically conductive.

[0066] In this embodiment, the battery cell 910 may be a wound structure or a laminated structure, which is not limited in this embodiment of the present application.

[0067] The battery cell 910 includes a battery cell body 920 and a tab. The battery cell body 920 is formed by winding a positive electrode sheet, a negative electrode sheet, and an insulating film 500 located between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet and the negative electrode sheet each include a first portion coated with an active material and a second portion extending outward from the first portion and not coated with the active material.

[0068] The battery cell body 920 includes an upper end surface 921 and a lower end surface 922. The upper end surface 921 and the lower end surface 922 are arranged opposite to each other along the height direction (i.e., the Z-axis direction) of the battery cell body 920. The battery cell body 920 also includes a side surface 923. The side surface 923 connects the upper end surface 921 and the lower end surface 922 and is arranged around the edges of the upper end surface 921 and the lower end surface 922.

[0069] The tabs include a first tab 930 and a second tab 940. The first tab 930 and the second tab 940 are both connected to the cell body 920 and electrically conductive. Along the Z-axis direction, the first tab 930 and the second tab 940 are located on the same side of the cell body 920. The first tab 930 and the second tab 940 both extend out of the upper end surface 921 of the cell body 920. The first tab 930 is used to connect to the first connector 300 and electrically conductive. The second tab 940 is used to connect to the second connector 400 and electrically conductive. Along the Y-axis direction, the first tab 930 and the second tab 940 are spaced apart. In this embodiment, the first tab 930 may be a positive tab, and the second tab 940 may be a negative tab. In some other embodiments, the first tab 930 may be a negative tab, and the second tab 940 may be a positive tab.

[0070] Please refer to Figure 3 and Figure 4 , Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure of a first connecting member and a second connecting member in the energy storage device is shown.

[0071] In this embodiment, the first connecting member 300 is made of a metal material. The first connecting member 300 includes a first connecting portion 360, a first adapter portion 370 and a first bending portion 380. The first bending portion 380 is located between the first connecting portion 360 and the first adapter portion 370, and is connected to the first connecting portion 360 and the first adapter portion 370 at an angle. Through the first bending portion 380, the first adapter portion 370 can be bent relative to the first connecting portion 360. The first connecting portion 360 is used to connect and electrically conduct with the first pole ear 930. The first adapter portion 370 is used to connect and electrically conduct with the end cover assembly 100.

[0072] The first connection portion 360 includes a first connection outer surface 361 and a first connection inner surface 362. The first connection outer surface 361 and the first connection inner surface 362 are disposed opposite to each other along the thickness direction (ie, the Z-axis direction) of the first connection portion 360. In this embodiment, the first connection portion 360 is a rectangular sheet.

[0073] The first adapter portion 370 includes a first adapter outer surface 371 and a first adapter inner surface 372. The first adapter outer surface 371 and the first adapter inner surface 372 are arranged opposite to each other along the thickness direction (i.e., the Z-axis direction) of the first adapter portion 370. The first adapter portion 370 also includes a first groove 373. The first groove 373 is recessed in the first adapter inner surface 372. The first groove 373 is recessed from the first adapter inner surface 372 toward the first adapter outer surface 371, and protrudes from the first adapter inner surface 372 to form a first convex bump 374. It can be understood that the first adapter portion 370 also includes a first convex bump 374, which is protruding from the first adapter outer surface 371. The first convex bump 374 extends in a direction away from the first adapter portion 370. The first convex bump 374 can be formed by the first adapter portion 370 through a stamping process. The first convex bump 374 is used to be inserted into the end cap assembly 100 and connected to the end cap assembly 100. The first convex hump 374 includes a first top surface 375 and a first peripheral surface 376. The first top surface 375 is away from the first adapter outer surface 371, and the first top surface 375 is oriented in the same direction as the first adapter outer surface 371. The first peripheral surface 376 connects the first top surface 375 and the first adapter outer surface 371, and surrounds the periphery of the first top surface 375. In this embodiment, the shape of the first convex hump 374 is an ellipse. The first adapter portion 370 is a rectangular sheet.

[0074] It should be noted that along the Z-axis direction, the first adapter outer surface 371 of the first adapter part 370 protrudes compared to the first connection outer surface 361 of the first connection part 360 , and the first adapter inner surface 372 of the first adapter part 370 protrudes compared to the first connection outer surface 361 of the first connection part 360 .

[0075] In this embodiment, the structure of the second connecting member 400 is the same as that of the first connecting member 300. The second connecting member 400 is made of metal material. The second connecting member 400 includes a second connecting portion 460, a second adapter portion 470 and a second bending portion 480. The second bending portion 480 is located between the second connecting portion 460 and the second adapter portion 470, and is connected to the second connecting portion 460 and the second adapter portion 470 at an angle. Through the second bending portion 480, the second adapter portion 470 can be bent relative to the second connecting portion 460. The second connecting portion 460 is used to connect and electrically conduct with the second pole ear 940. The second adapter portion 470 is used to connect and electrically conduct with the end cover assembly 100.

[0076] The second connection part 460 includes a second connection inner surface 462 and a second connection outer surface 461. The second connection inner surface 462 and the second connection outer surface 461 are disposed opposite to each other along the thickness direction (ie, the Z-axis direction) of the second connection part 460. In this embodiment, the second connection part 460 is a rectangular sheet.

[0077] The second adapter part 470 includes a second adapter inner surface 472 and a second adapter outer surface 471. The second adapter inner surface 472 and the second adapter outer surface 471 are arranged opposite to each other along the thickness direction (i.e., the Z-axis direction) of the second adapter part 470. The second adapter part 470 also includes a second groove 473. The second groove 473 is recessed in the second adapter inner surface 472. The second groove 473 is recessed from the second adapter inner surface 472 to the direction of the second adapter outer surface 471, and protrudes from the second adapter inner surface 472 to form a second convex hump 474. It can be understood that the second adapter part 470 also includes a second convex hump 474, which is protruding from the second adapter outer surface 471. The second convex hump 474 extends in a direction away from the second adapter part 470. The second convex hump 474 can be formed by the second adapter part 470 through a stamping process. The second convex hump 474 is used to be inserted into the end cap assembly 100 and connected to the end cap assembly 100. The second convex hump 474 includes a second top surface 475 and a second peripheral surface 476. The second top surface 475 is away from the second adapter outer surface 471, and the second top surface 475 is oriented in the same direction as the second adapter outer surface 471. The second peripheral surface 476 connects the second top surface 475 and the second adapter outer surface 471, and surrounds the periphery of the second top surface 475. In this embodiment, the shape of the second convex hump 474 is an ellipse. The second adapter portion 470 is a rectangular sheet.

[0078] It should be noted that along the Z-axis direction, the second adapter outer surface 471 of the second adapter part 470 protrudes compared to the second connection outer surface 461 of the second connection part 460 , and the second adapter inner surface 472 of the second adapter part 470 protrudes compared to the second connection outer surface 461 of the second connection part 460 .

[0079] Please refer to Figure 5 , Figure 6 and Figure 7 , Figure 5 for Figure 3 The schematic diagram of the exploded structure of the first embodiment of the end cover assembly in the energy storage device shown in FIG. Figure 6 for Figure 5 The schematic diagram of the exploded structure of the end cap assembly shown in FIG. Figure 7 for Figure 5 A cross-sectional schematic diagram of a partially exploded structure of an end cap assembly is shown.

[0080] In this embodiment, the end cap assembly 100 includes an end cap 10, a first pole 30, a second pole 40, a first upper plastic 50, a second upper plastic 60, a first sealing ring 71, a second sealing ring 72, a lower plastic 20, a first pressing block 80 and a second pressing block 81. The end cap 10 and the lower plastic 20 are stacked along the thickness direction (i.e., the Z-axis direction) of the end cap assembly 100. The first pole 30 and the second pole 40 are respectively located at opposite ends of the length direction (i.e., the Y-axis direction) of the end cap assembly 100. The first upper plastic 50, the first sealing ring 71 and the first pressing block 80 are sequentially sleeved on the first pole 30. The first pole 30 is insulated and sealed with the end cap 10 by the cooperation of the first upper plastic 50, the first sealing ring 71 and the lower plastic 20. The second upper plastic 60, the second sealing ring 72 and the second pressing block 81 are sequentially sleeved on the second pole 40. The second pole 40 is insulated and sealed with the end cap 10 by the cooperation of the second upper plastic 60, the second sealing ring 72 and the lower plastic 20. Among them, the first pole 30 can be defined as a positive pole and the second pole 40 can be defined as a negative pole. In other embodiments, the first pole 30 can also be defined as a negative pole and the second pole 40 can be defined as a positive pole. The end cap assembly 100 also includes an explosion-proof valve 90. The explosion-proof valve 90 is used to discharge the gas inside the energy storage device 1000 to relieve pressure and prevent the risk of explosion caused by the accumulation of gas inside the energy storage device 1000. The explosion-proof valve 90 includes an explosion-proof fence 91, an explosion-proof valve sheet 92 and a protective sheet 93. The explosion-proof fence 91 is provided on the lower plastic 20. The explosion-proof valve sheet 92 and the protective sheet 93 are both installed on the end cap 10, and the explosion-proof valve sheet 92 and the protective sheet 93 are arranged at intervals along the Z-axis direction. The explosion-proof valve sheet 92 completely covers the explosion-proof fence 91. That is, along the Z-axis direction, the orthographic projection of the explosion-proof valve 90 on the lower plastic 20 is located inside the explosion-proof fence 91 .

[0081] See Figure 5 and Figure 6 In this embodiment, the shape of the end cap 10 is substantially rectangular. The end cap 10 is a plain aluminum sheet. The end cap 10 includes an end cap body 11. The end cap body 11 includes a first surface 111 and a second surface 112. The first surface 111 and the second surface 112 are arranged opposite to each other along the thickness direction (i.e., the Z-axis direction) of the end cap body 11.

[0082] See Figure 6 and Figure 7, the end cover 10 includes a first assembly groove 12 and a second assembly groove 13. The first assembly groove 12 and the second assembly groove 13 are respectively located at opposite ends of the length direction of the end cover body 11. The first assembly groove 12 and the second assembly groove 13 are both recessed in the second surface 112 of the end cover body 11. The first assembly groove 12 is recessed from the second surface 112 to the direction of the first surface 111 and forms a first inclined boss 14. The first assembly groove 12 is used to accommodate the first sealing ring 71 and the first pressing block 80. The second assembly groove 13 is recessed from the second surface 112 to the direction of the first surface 111 and forms a second inclined boss 15. The second assembly groove 13 is used to accommodate the second sealing ring 72 and the second pressing block 81. In addition, the first assembly groove 12 and the second assembly groove 13 also respectively accommodate part of the lower plastic 20. It can be understood that the end cover 10 also includes a first inclined boss 14 and a second inclined boss 15. The first inclined boss 14 and the second inclined boss 15 are respectively located at opposite ends of the direction of the end cover body 11. The first inclined boss 14 and the second inclined boss 15 are both convexly disposed on the first surface 111 of the end cover body 11. In this embodiment, the first assembly groove 12 and the second assembly groove 13 are both elliptical in shape. The first inclined boss 14 and the second inclined boss 15 are both elliptical in shape.

[0083] The first inclined boss 14 includes a first boss surface 141 and a first inclined peripheral surface 142. The first boss surface 141 is away from the first surface 111, and the orientation of the first boss surface 141 is the same as that of the first surface 111. The first inclined peripheral surface 142 is connected to the first boss surface 141 and the first surface 111 of the end cover body 11. The first inclined peripheral surface 142 is inclined toward the direction of the first boss surface 141. That is, the first inclined peripheral surface 142 is an inclined surface or an arc surface.

[0084] The second inclined boss 15 includes a second boss surface 151 and a second inclined peripheral surface 152. The second boss surface 151 is away from the first surface 111, and the direction of the second boss surface 151 is the same as the direction of the first surface 111. The second inclined peripheral surface 152 is connected to the second boss surface 151 and the first surface 111. The second inclined peripheral surface 152 is inclined toward the direction of the second boss surface 151. That is, the second inclined peripheral surface 152 is an inclined surface or an arc surface.

[0085] The end cover 10 further includes a first through hole 1 and a second through hole 2. The first through hole 1 penetrates the first boss surface 141 of the first inclined boss 14 and the bottom wall of the first assembly groove 12. The first through hole 1 is used for the first pole 30 to pass through. The second through hole 2 penetrates the second boss surface 151 of the second inclined boss 15 and the bottom wall of the second assembly groove 13. The second through hole 2 is used for the second pole 40 to pass through.

[0086] The end cover 10 further includes a pressure relief hole 16. Along the Y-axis direction, the pressure relief hole 16 is located between the first through hole 1 and the first through hole 1, and is spaced apart from the first through hole 1 and the second through hole 2. The pressure relief hole 16 penetrates the first surface 111 and the second surface 112 of the end cover body 11. The pressure relief hole 16 is used to allow the gas inside the energy storage device 1000 to pass through and be discharged to the outside of the energy storage device 1000.

[0087] The end cover 10 also includes a first annular groove 17 and a second annular groove 18. The first annular groove 17 is recessed in the first surface 111 and is recessed in the direction of the second surface 112. The first annular groove 17 is connected to the hole wall of the pressure relief hole 16 and is arranged around the periphery of the pressure relief hole 16. The first annular groove 17 is used to accommodate the protective sheet 93. The second annular groove 18 is recessed in the second surface 112 and is recessed in the direction of the first surface 111. The second annular groove 18 is connected to the hole wall of the pressure relief hole 16 and is arranged around the periphery of the pressure relief hole 16. The second annular groove 18 is used to accommodate the explosion-proof valve sheet 92.

[0088] In some embodiments, Figure 6 As shown, the end cap 10 further includes a plurality of limit grooves 19. The plurality of limit grooves 19 are all recessed in the second surface 112. The limit grooves 19 are used to accommodate part of the lower plastic 20. Exemplarily, the number of the limit grooves 19 is four. Two limit grooves 19 are located on one side of the outer circumference of the first assembly groove 12 and are symmetrically arranged about the central axis in the length direction of the end cap 10. The other two limit grooves 19 are located on one side of the outer circumference of the second assembly groove 13 and are symmetrically arranged about the central axis in the length direction of the end cap 10.

[0089] See Figure 5 and Figure 6 The lower plastic 20 includes a lower plastic body 21. The lower plastic body 21 includes an upper surface 211 and a lower surface 212. The upper surface 211 and the lower surface 212 are disposed opposite to each other along the thickness direction (ie, the Z-axis direction) of the lower plastic body 21.

[0090] The lower plastic 20 also includes a first assembly protrusion 22 and a second assembly protrusion 23. The first assembly protrusion 22 and the second assembly protrusion 23 are respectively located at opposite ends of the length direction (i.e., the Y-axis direction) of the lower plastic 20. The first assembly protrusion 22 and the second assembly protrusion 23 are both convexly arranged on the upper surface 211. The first assembly protrusion 22 is accommodated in the first assembly groove 12 of the end cover 10. The first assembly protrusion 22 includes a first convex surface 221. The first convex surface 221 is away from the upper surface 211, and the orientation of the first convex surface 221 is the same as the orientation of the upper surface 211. The second assembly protrusion 23 is accommodated in the second assembly groove 13 of the end cover 10. The second assembly protrusion 23 includes a second convex surface 231. The second convex surface 231 is away from the upper surface 211, and the orientation of the second convex surface 231 is the same as the orientation of the upper surface 211.

[0091] The lower plastic 20 further includes a first through hole 24 and a second through hole 25. Along the Z-axis direction, the first through hole 24 penetrates the first convex surface 221 and the lower surface 212. The first through hole 24 is used for the first pole 30 to pass through. The second through hole 25 penetrates the second convex surface 231 and the lower surface 212. The second through hole 25 is used for the second pole 40 to pass through.

[0092] It can also be understood that the first assembly protrusion 22 surrounds the periphery of the first through hole 24 and is connected to the hole wall of the first through hole 24. The second assembly protrusion 23 surrounds the periphery of the second through hole 25 and is connected to the hole wall of the second through hole 25.

[0093] In some embodiments, the lower plastic 20 further includes a plurality of limiting posts 26. The plurality of limiting posts 26 are all protruding from the upper surface 211. The limiting posts 26 are accommodated in the limiting grooves 19. Exemplarily, the number of limiting posts 26 matches the number of limiting grooves 19. The number of limiting posts 26 is four. Two limiting posts 26 are located on one side of the outer circumference of the first assembly protrusion 22 and are symmetrically arranged about the central axis in the length direction of the lower plastic 20. The other two limiting posts 26 are located on one side of the outer circumference of the second assembly protrusion 23 and are symmetrically arranged about the central axis in the length direction of the lower plastic 20.

[0094] See Figure 7 In this embodiment, the first pole 30 is a roughly T-shaped column structure. The first pole 30 includes a first main body 31 and a first flange 32. Along the height direction of the first pole 30 (i.e., the Z-axis direction), the first main body 31 is connected to the surface of one side of the first flange 32. The first flange 32 is an elliptical block, which includes a first top surface 321 and a first bottom surface 322. The first top surface 321 and the first bottom surface 322 are arranged opposite to each other along the thickness direction of the first flange 32. The first main body 31 is convexly arranged on the first bottom surface 322 of the first flange 32. The first main body 31 includes a first end face 311. The first end face 311 is away from the first flange 32, and its direction is the same as the direction of the first bottom surface 322 of the first flange 32. The first main body 31 is coaxially arranged with the first flange 32. The first main body 31 is an elliptical cylinder.

[0095] The first pole 30 also includes a first step 33. The first step 33 is arranged around the outer periphery of the first body 31. The first step 33 is formed by cutting the periphery of a portion of the end of the first body 31. It can also be understood that the first step 33 is formed by a portion of the end of the first body 31 being recessed toward the center of the first body 31. The first step 33 includes a first step surface 331. The first step surface 331 is arranged away from the first flange 32, and the orientation of the first step surface 331 is the same as the orientation of the first bottom surface 322. In this embodiment, the first step surface 331 is an annular surface.

[0096] The first pole 30 further includes a first pole through hole 34. The first pole through hole 34 penetrates both sides of the first flange 32 and the first body 31 in the thickness direction, that is, the first pole through hole 34 penetrates the first top surface 321 of the first flange 32 and the first end surface 311 of the first body 31. The first pole through hole 34 is used for the first convex hump 374 to pass through, and the hole wall of the first pole through hole 34 is used to abut against the first circumferential surface 376 of the first convex hump 374. In this embodiment, the first pole through hole 34 is an elliptical hole.

[0097] The first pole 30 also includes a first recessed groove 35. The first recessed groove 35 is recessed in the first top surface 321 of the first flange 32 and is recessed in the direction of the first end surface 311 of the first body 31. The first recessed groove 35 is arranged around the periphery of the first pole through hole 34 and is connected to the first pole through hole 34. The first recessed groove 35 is used to accommodate the weld produced when the first convex bump 374 is welded to the first pole 30. In this embodiment, the first recessed groove 35 is an elliptical groove body. The radial dimension of the first recessed groove 35 is smaller than the radial dimension of the first body 31.

[0098] In this embodiment, the structure of the second pole 40 is similar to that of the first pole 30. In this embodiment, the second pole 40 is a cylindrical structure with a T-shaped cross section. The second pole 40 includes a second body 41 and a second flange 42. Along the height direction of the second pole 40 (i.e., the Z-axis direction), the second body 41 is connected to the surface of one side of the second flange 42. The second flange 42 is an elliptical block, which includes a second top surface 421 and a second bottom surface 422. The second top surface 421 and the second bottom surface 422 are arranged opposite to each other along the thickness direction of the second flange 42. The second body 41 is convexly arranged on the second bottom surface 422 of the second flange 42. The second body 41 includes a second end face 411. The second end face 411 is away from the second flange 42, and its direction is the same as the second bottom surface 422 of the second flange 42. The second body 41 and the second flange 42 are coaxially arranged. The second body 41 is an elliptical cylinder.

[0099] The second pole 40 also includes a second step 43. The second step 43 is arranged around the outer periphery of the second body 41. The second step 43 is formed by cutting the periphery of a portion of the end of the second body 41. It can also be understood that the second step 43 is formed by a portion of the end of the second body 41 being recessed toward the center of the second body 41. The second step 43 includes a second step surface 431. The second step surface 431 is arranged away from the second flange 42, and the direction of the second step surface 431 is the same as the direction of the first bottom surface 322. In this embodiment, the second step surface 431 is an annular surface.

[0100] The second pole 40 further includes a second pole through hole 44. The second pole through hole 44 penetrates both sides of the second flange 42 and the second body 41 in the thickness direction, that is, the second pole through hole 44 penetrates the first bottom surface 322 of the second flange 42 and the second end surface 411 of the second body 41. The second pole through hole 44 is used for the second convex hump 474 to pass through, and the hole wall of the second pole through hole 44 is used to abut against the second circumferential surface 476 of the second convex hump 474. In this embodiment, the second pole through hole 44 is an elliptical hole.

[0101] The second pole 40 also includes a second recessed groove 45. The second recessed groove 45 is recessed in the second top surface 421 of the second flange 42 and is recessed in the direction of the second end surface 411 of the second body 41. The second recessed groove 45 is arranged around the periphery of the second pole through hole 44 and is connected to the second pole through hole 44. The second recessed groove 45 is used to accommodate the weld produced when the second convex bump 474 is welded to the second pole 40. In this embodiment, the second recessed groove 45 is an elliptical groove body. The radial dimension of the second recessed groove 45 is smaller than the radial dimension of the second body 41.

[0102] See you next time Figure 7 , Figure 7 The middle dashed line indicates the boundary between the first body section 51, the first protruding section 52 and the first extension section 53, and also indicates the boundary between the second body section 61, the second protruding section 62 and the second extension section 63. In this embodiment, the edge of the first upper plastic 50 is formed into a flying saucer shape.

[0103] The first upper plastic 50 includes a first body section 51, a first protruding section 52 and a first extension section 53. The first body section 51 is connected to the outer periphery of the first extension section 53, and the first extension section 53 extends along the height direction (i.e., the Z-axis direction) of the first upper plastic 50. The extension direction of the first body section 51 intersects with the extension direction of the first extension section 53, and the first extension section 53 encloses a first insulating hole 54. The first insulating hole 54 is an elliptical hole. The first protruding section 52 extends from the first body section 51 away from the outer periphery of the first extension section 53, and the extension direction is the same as the extension direction of the first body section 51. The first body section 51 includes a first upper surface 511 and a first lower surface 512. The first upper surface 511 and the first lower surface 512 are arranged opposite to each other along the thickness direction (i.e., the Z-axis direction) of the first body section 51. The first protruding section 52 includes a first upper arc surface 521 and a first lower arc surface 522. The first upper curved surface 521 and the first lower curved surface 522 are disposed opposite to each other along the thickness direction (i.e., the Z-axis direction) of the first protruding section 52. The first upper curved surface 521 is connected to the first upper surface 511 of the first body section 51 and is inclined relative to the first upper surface 511, and the first lower curved surface 522 is connected to the first lower surface 512 of the first body section 51 and is inclined relative to the first lower surface 512. In this embodiment, the first upper surface 511 and the first lower surface 512 are both planes. The first upper curved surface 521 and the first lower curved surface 522 are both arc-shaped surfaces.

[0104] It should be noted that the width of the first upper surface 511 is smaller than the width of the first lower surface 512. The width of the first upper curved surface 521 is larger than the width of the first lower curved surface 522. The angle at which the first upper curved surface 521 is inclined relative to the first upper surface 511 is smaller than the angle at which the first lower curved surface 522 is inclined relative to the first lower surface 512. It can be understood that the inclination of the first upper curved surface 521 is smaller than the inclination of the first lower curved surface 522.

[0105] In this embodiment, the structure of the second upper plastic 60 is the same as that of the first upper plastic 50. The edge of the first upper plastic 50 is formed in a flying saucer shape. The second upper plastic 60 includes a second body section 61, a second protruding section 62, and a second extension section 63. The second body section 61 is connected to the outer periphery of the second extension section 63, and the second extension section 63 extends along the height direction (i.e., the Z-axis direction) of the second upper plastic 60. The extension direction of the second body section 61 intersects with the extension direction of the first extension section 53, and the second extension section 63 encloses a second insulating hole 64. The second insulating hole 64 is an elliptical hole. The second protruding section 62 extends from the second body section 61 away from the outer periphery of the second extension section 63, and the extension direction is the same as the extension direction of the second body section 61. The second body section 61 includes a second upper surface 611 and a second lower surface 612. The second upper surface 611 and the second lower surface 612 are arranged opposite to each other along the thickness direction (i.e., the Z-axis direction) of the second body section 61. The second protruding section 62 includes a second upper arc surface 621 and a second lower arc surface 622. The second upper curved surface 621 and the second lower curved surface 622 are disposed opposite to each other along the thickness direction (i.e., the Z-axis direction) of the second protruding section 62. The second upper curved surface 621 is connected to the second upper surface 611 of the second body section 61 and is inclined relative to the second upper surface 611, and the second lower curved surface 622 is connected to the second lower surface 612 of the second body section 61 and forms an angle with the second lower surface 612. In this embodiment, the second upper surface 611 and the second lower surface 612 are both planes. The second upper curved surface 621 and the second lower curved surface 622 are both arc-shaped surfaces.

[0106] It should be noted that the width of the second upper surface 611 is smaller than the width of the second lower surface 612. The width of the second upper curved surface 621 is larger than the width of the second lower curved surface 622. The angle at which the second upper curved surface 621 is inclined relative to the second upper surface 611 is smaller than the angle at which the second lower curved surface 622 is inclined relative to the second lower surface 612. It can be understood that the inclination of the second upper curved surface 621 is smaller than the inclination of the second lower curved surface 622.

[0107] See Figure 5 and Figure 6The first sealing ring 71 is used to insulate and seal the first pole 30 from the end cover 10. The first sealing ring 71 includes a first sealing hole 711. The first sealing hole 711 penetrates both surfaces of the first sealing ring 71 in the thickness direction. The first sealing hole 711 is used for the first pole 30 to pass through. In this embodiment, the shape of the first sealing ring 71 is elliptical. The first sealing hole 711 is an elliptical hole.

[0108] In this embodiment, the structure of the second sealing ring 72 is the same as that of the first sealing ring 71. The second sealing ring 72 is used to insulate and seal the second pole 40 from the end cover 10. The second sealing ring 72 includes a second sealing hole 721. The second sealing hole 721 penetrates both surfaces of the second sealing ring 72 in the thickness direction. The second sealing hole 721 is used for the second pole 40 to pass through. The shape of the second sealing ring 72 is elliptical. The second sealing hole 721 is an elliptical hole.

[0109] The first pressing block 80 is used to press the first sealing ring 71 toward the first flange 32 and deform the first sealing ring 71. The first pressing block 80 includes a first connecting hole 801. The first connecting hole 801 runs through both surfaces of the first pressing block 80 in the thickness direction. The first connecting hole 801 is used for the first pole 30 to pass through. In this embodiment, the shape of the first pressing block 80 is elliptical. The first connecting hole 801 is an elliptical hole.

[0110] In this embodiment, the structure of the second pressing block 81 is the same as that of the first pressing block 80. The second pressing block 81 is used to press the second sealing ring 72 toward the second flange 42 and deform the second sealing ring 72. The second pressing block 81 includes a second connecting hole 811. The second connecting hole 811 runs through both surfaces of the second pressing block 81 in the thickness direction. The second connecting hole 811 is used for the second pole 40 to pass through. The shape of the second pressing block 81 is elliptical. The second connecting hole 811 is an elliptical hole.

[0111] Please also read Figure 8 , Figure 8 for Figure 5 A schematic diagram of the cross-sectional structure of the end cover assembly in the energy storage device shown.

[0112] The first pole 30 , the second pole 40 , the first upper plastic 50 , the second upper plastic 60 , the first sealing ring 71 , the second sealing ring 72 , the lower plastic 20 , the explosion-proof valve 90 , the first pressing block 80 and the second pressing block 81 are assembled together on the end cover 10 to form an end cover assembly 100 .

[0113] The explosion-proof fence 91 of the explosion-proof valve 90 is arranged on the lower plastic body 21. Along the Y-axis direction, the explosion-proof fence 91 is located between the first assembly protrusion 22 and the second assembly protrusion 23, and is spaced apart from the first assembly protrusion 22 and the second assembly protrusion 23. The explosion-proof valve sheet 92 of the explosion-proof valve 90 is accommodated in the first annular groove 17 of the end cover 10, and at the same time, the protection sheet 93 of the explosion-proof valve 90 is accommodated in the second annular groove 18 of the end cover 10, so that the thickness of the end cover assembly 100 is reduced.

[0114] Along the Z-axis direction, the upper surface 211 of the lower plastic 20 is connected to the second surface 112 of the end cover 10. The first assembly protrusion 22 of the lower plastic 20 is accommodated in the first assembly groove 12 of the end cover 10, and the first convex surface 221 of the first assembly protrusion 22 abuts against the bottom wall of the first assembly groove 12. At the same time, the second assembly protrusion 23 is accommodated in the second assembly groove 13 of the end cover 10, and the second convex surface 231 of the second assembly protrusion 23 abuts against the bottom wall of the second assembly groove 13 to achieve the limit fixation of the lower plastic 20 on the end cover 10. Each limit post 26 of the lower plastic 20 is accommodated in a limit groove 19 of the end cover 10 to further limit and fix the lower plastic 20 to the end cover 10. Along the Z-axis direction, the first through hole 24 of the lower plastic 20 and the first through hole 1 of the end cover 10 are coaxially arranged and connected. The second through hole 25 and the second through hole 2 are coaxially arranged and connected.

[0115] The first pole 30 abuts the first upper plastic 50 against the end cover 10, and the first upper plastic 50 is used to achieve insulation and sealing with the end cover 10. The first extension section 53 of the first upper plastic 50 is provided in the first through hole 1 of the end cover 10. The first main body 31 of the first pole 30 is provided in the first insulating hole 54 of the first upper plastic 50. Along the axial direction of the first through hole 1, the first body section 51 of the first upper plastic 50 is located between the first flange 32 and the first inclined boss 14. The first upper surface 511 of the first body section 51 abuts against the first bottom surface 322 of the first flange 32. The first lower surface 512 of the first body section 51 abuts against the first boss surface 141 of the first inclined boss 14. Along the direction of the first protruding section 52 away from the axis of the first through hole 1, the first protruding section 52 of the first upper plastic 50 protrudes from the outer periphery of the first flange 32 to increase the creepage distance between the first pole 30 and the end cover 10, ensure the insulation performance between the first pole 30 and the end cover 10, and improve the safety of the energy storage device 1000. In addition, because the width of the first upper arc surface 521 is greater than the width of the first lower arc surface 522, the first upper plastic 50 can further increase the creepage distance between the first pole 30 and the end cover 10.

[0116] The first upper arc surface 521 of the first protruding section 52 is set at an angle with the first surface 111 of the end cover 10, and forms a slope, which is conducive to the electrolyte splashed onto the first upper plastic 50 to slide down to the first surface 111 of the end cover 10, so as to avoid the electrolyte splashed on the first upper plastic 50 and unable to slide down and accumulate, thereby ensuring the performance of the first upper plastic 50. The first lower arc surface 522 of the first protruding section 52 faces the end cover 10, and forms a circular notch with a cross section of "<" shape with the first inclined peripheral surface 142 of the first inclined boss 14, and the notch faces away from the first pole 30. It can be understood that the gap between the end cover 10 and the first upper plastic 50 has a large exposed area, which is conducive to wiping off the electrolyte dripping between the end cover 10 and the first upper plastic 50.

[0117] In addition, the inventors have found through research that when electrolyte penetrates from the outside of the energy storage device 1000 through the assembly gap between the first upper plastic 50 and the end cover 10 into the inside of the energy storage device 1000 and stays there for a long time, the electrolyte will corrode the first sealing ring 71 in the end cover assembly 100 and cause the seal to fail. At the same time, the residual electrolyte is prone to form white crystals due to oxidation or drying, which not only destroys the uniformity of the force on the inside of the first sealing ring 71, thereby causing the seal to fail, but also remains in the assembly gap between the end cover 10 and the first upper plastic 50, affecting the appearance performance of the energy storage device 1000. In the embodiment of the present application, along the direction in which the first protruding section 52 is away from the axis of the first through hole 1, the first protruding section 52 protrudes from the outer periphery of the first inclined boss 14 of the end cover 10, so that the electrolyte that slides off the first upper plastic 50 will not penetrate into the interior of the energy storage device 1000 from the assembly gap between the first upper plastic 50 and the end cover 10, preventing the electrolyte from affecting the first sealing ring 71, thereby ensuring the sealing performance of the first sealing ring 71. At the same time, the first protruding section 52 can block the assembly gap between the end cover 10 and the first upper plastic 50, so that the first protruding section 52 can block the white crystals formed at the assembly gap between the end cover 10 and the first upper plastic 50, thereby reducing the defective rate of the appearance of the energy storage device 1000.

[0118] It should be noted that the assembly gap between the first body section 51 of the first upper plastic 50 and the first flange 32 and the assembly gap between the first body section 51 and the end cover 10 are both located in the direction of the first protruding section 52 away from the axis of the first through hole 1. The first body section 51 and the first flange 32 both extend parallel to the end cover 10, that is, the first upper surface 511 of the first body section 51 is parallel to the first bottom surface 322 of the first flange 32. During the manufacturing process of the energy storage device 1000, the electrolyte dripping on the end cover 10 is prevented from splashing onto the first pole 30 and flowing into the above-mentioned assembly gap, further reducing the appearance defect rate of the energy storage device 1000. At the same time, the risk of welding explosion points when the first connector 300 and the first pole 30 are welded due to the presence of residual electrolyte in the above-mentioned assembly gap is also avoided.

[0119] The first sealing ring 71 is sleeved on the outer circumference of the first body 31 and is accommodated in the first assembly groove 12. The first sealing ring 71 includes a first sealing hole 711, and the first sealing hole 711 runs through both sides of the first sealing ring 71 in the thickness direction.

[0120] The first pressing block 80 is sleeved on the outer periphery of the first main body 31 and is pressed against the first sealing ring 71, so that the first sealing ring 71 is deformed and interference fits with the surrounding components, thereby improving the sealing performance of the end cover assembly 100. The surface of the first pressing block 80 facing the first sealing ring 71 abuts against the first step surface 331 of the first step 33. The first pressing block 80 includes a first connecting hole 801, and the first connecting hole 801 runs through both sides of the first pressing block 80 in the thickness direction. The first pressing block 80 is connected to the first pole 30 by welding and is electrically conductive, and the first pressing block 80 is insulated from the end cover 10 through the first sealing ring 71 and the lower plastic 20.

[0121] It can be understood that the first insulating hole 54 of the first upper plastic 50, the first through hole 1 of the end cover 10, the first through hole 24 of the lower plastic 20, the first sealing hole 711 of the first sealing ring 71 and the first connecting hole 801 of the first pressing block 80 are coaxially arranged, and the first body 31 of the first pole 30 is sequentially penetrated through the first insulating hole 54, the first through hole 1, the first through hole 24, the first sealing hole 711 and the first connecting hole 801.

[0122] The second pole 40 abuts the second upper plastic 60 against the end cover 10, and the second upper plastic 60 is used to achieve insulation and sealing with the end cover 10. The second extension section 63 of the second upper plastic 60 is provided in the second through hole 2 of the end cover 10. The second main body 41 of the second pole 40 is provided in the second insulating hole 64 of the second upper plastic 60. Along the axial direction of the second through hole 2, the second body section 61 of the second upper plastic 60 is located between the second flange 42 and the second inclined boss 15. The second upper surface 611 of the second body section 61 abuts against the second bottom surface 422 of the second flange 42. The second lower surface 612 of the second body section 61 abuts against the second boss surface 151 of the second inclined boss 15. Along the direction of the second protruding section 62 away from the axis of the second through hole 2, the second protruding section 62 of the second upper plastic 60 protrudes from the outer periphery of the second flange 42 to increase the creepage distance between the second pole 40 and the end cover 10, ensure the insulation performance between the second pole 40 and the end cover 10, and improve the safety of the energy storage device 1000. In addition, because the width of the second upper arc surface 621 is greater than the width of the second lower arc surface 622, the second upper plastic 60 can further increase the creepage distance between the second pole 40 and the end cover 10.

[0123] The second upper arc surface 621 of the second protruding section 62 is set at an angle with the first surface 111 of the end cover 10, and forms a slope, which is conducive to the electrolyte splashed onto the second upper plastic 60 to slide down to the first surface 111 of the end cover 10, so as to avoid the electrolyte splashed on the second upper plastic 60 and unable to slide down and accumulate, thereby ensuring the performance of the second upper plastic 60. The second lower arc surface 622 of the second protruding section 62 faces the end cover 10, and forms a circular notch with a cross section of "<" shape with the second inclined peripheral surface 152 of the second inclined boss 15, and the notch faces away from the second pole 40. It can be understood that the assembly gap between the end cover 10 and the second upper plastic 60 has a large exposed area, which is conducive to wiping off the electrolyte dripping between the end cover 10 and the second upper plastic 60.

[0124] In addition, the inventors have found through research that when electrolyte penetrates from the outside of the energy storage device 1000 through the assembly gap between the end cap 10 and the second upper plastic 60 into the inside of the energy storage device 1000 and stays there for a long time, the electrolyte will corrode the second sealing ring 72 in the end cap assembly 100 and cause the seal to fail. At the same time, the residual electrolyte is prone to form white crystals due to oxidation or drying, which not only destroys the uniformity of the force on the inside of the second sealing ring 72, thereby causing the seal to fail, but also remains in the assembly gap between the end cap 10 and the second upper plastic 60, affecting the appearance performance of the energy storage device 1000. In the embodiment of the present application, along the direction in which the second protruding section 62 is away from the axis of the second through hole 2, the second protruding section 62 protrudes from the outer periphery of the second inclined boss 15 of the end cover 10, so that the electrolyte that slides off the second upper plastic 60 will not penetrate into the energy storage device 1000 from the assembly gap between the second upper plastic 60 and the end cover 10, preventing the electrolyte from affecting the second sealing ring 72, thereby ensuring the sealing performance of the second sealing ring 72. At the same time, the second protruding section 62 can block the assembly gap between the end cover 10 and the second upper plastic 60, thereby blocking the white crystals formed at the assembly gap between the end cover 10 and the second upper plastic 60, and reducing the defect rate of the appearance of the energy storage device 1000.

[0125] It should be noted that the assembly gap between the second body section 61 of the second upper plastic 60 and the second flange 42 and the assembly gap between the second body section 61 and the end cover 10 are both located in the direction of the second protruding section 62 away from the axis of the second through hole 2. The second body section 61 and the second flange 42 both extend parallel to the end cover 10, that is, the second upper surface 611 of the second body section 61 is parallel to the second bottom surface 422 of the second flange 42. During the manufacturing process of the energy storage device 1000, the electrolyte dripping on the end cover 10 is prevented from splashing onto the second pole 40 and flowing into the above-mentioned assembly gap, further reducing the appearance defect rate of the energy storage device 1000, and also avoiding the risk of welding explosion points when the second connector 400 and the second pole 40 are welded due to the presence of residual electrolyte in the above-mentioned assembly gap.

[0126] The second sealing ring 72 is sleeved on the outer circumference of the second body 41 and is accommodated in the second assembly groove 13. The second sealing ring 72 includes a second sealing hole 721 which penetrates both sides of the second sealing ring 72 in the thickness direction.

[0127] The second pressing block 81 is sleeved on the outer periphery of the second main body 41 and is crimped on the second sealing ring 72, so that the second sealing ring 72 is deformed and interference fits with the surrounding components, thereby improving the sealing performance of the end cover assembly 100. The surface of the second pressing block 81 facing the second sealing ring 72 abuts against the second step surface 431 of the second step 43. The second pressing block 81 includes a second connection hole 811, and the second connection hole 811 runs through both sides of the second pressing block 81 in the thickness direction. The second pressing block 81 is connected to the second pole 40 by welding and is electrically conductive, and the second pressing block 81 is insulated from the end cover 10 by the second sealing ring 72 and the lower plastic 20.

[0128] It can be understood that the second insulating hole 64 of the second upper plastic 60, the second through hole 2 of the end cover 10, the second through hole 25 of the lower plastic 20, the second sealing hole 721 of the second sealing ring 72 and the second connecting hole 811 of the second pressing block 81 are coaxially arranged, and the second body 41 of the second pole 40 is sequentially penetrated through the second insulating hole 64, the second through hole 2, the second through hole 25, the second sealing hole 721 and the second connecting hole 811.

[0129] Please refer to Figure 3 , Figure 8 and Fig. 9 , Fig. 9 for Figure 2 The schematic diagram of the cross-sectional structure of the energy storage device along MM is shown. It should be noted that: Fig. 9 The outer envelope and protective member are not shown, and Fig. 9 for Figure 8 Schematic diagram of the structure of assembling the end cover assembly shown in with the remaining components.

[0130] The electrode assembly 900 , the first connector 300 , the second connector 400 , the end cap assembly 100 , the insulating film 500 and the support member 600 are installed together in the housing 200 , and the outer film 700 is wrapped around and at the bottom of the housing 200 to form an energy storage device 1000 .

[0131] Among them, Fig. 9As shown, the electrode assembly 900 is accommodated in the accommodating cavity 202 of the housing 200. The end cap assembly 100 is located at one end of the electrode assembly 900 facing the opening 201. The lower surface 212 of the lower plastic 20 abuts against the upper end surface 921 of the battery cell 910 in the electrode assembly 900. The first connector 300 and the second connector 400 are both located between the lower plastic 20 and the electrode assembly 900, and are spaced apart from the lower plastic 20. The first connector 300 is connected to the two first pole ears 930 of the electrode assembly 900 and the first pole column 30 of the end cap assembly 100 to electrically connect the electrode assembly 900 and the first pole column 30. The second connector 400 connects the two second pole ears 940 of the electrode assembly 900 and the second pole column 40 of the end cap assembly 100 to electrically connect the electrode assembly 900 and the second pole column 40.

[0132] Along the Z-axis direction, the first bending portion 380 of the first connector 300 extends away from the first pole tab 930. The first adapter portion 370 of the first connector 300 is spaced apart from the first pole tab 930, so as to separate the first adapter portion 370 from the first pole tab 930, thereby preventing the heat generated by the first connector 300 during current overflow from being transferred to the battery cell body 920 and affecting the performance of the battery cell body 920.

[0133] The first convex bump 374 of the first connector 300 is inserted into the first pole through hole 34 of the first pole 30 , and the first convex bump 374 is welded to the first pole 30 by seam welding and is electrically connected.

[0134] In this embodiment, the shape of the first convex bump 374 and the shape of the first pole through hole 34 are both elliptical, and when the first convex bump 374 is inserted into the first pole through hole 34, the circumference of the elliptical first convex bump 374 is longer than the circumference of the circular first convex bump 374, so the contact area between the first convex bump 374 and the first pole through hole 34 is larger, and after the first convex bump 374 and the first pole 30 are welded and electrically connected, the current flow capacity of the first connector 300 and the first pole 30 is increased, thereby improving the energy efficiency of the energy storage device 1000. At the same time, the elliptical first convex bump 374 cooperates with the elliptical first pole through hole 34, which can improve the torsional strength when the first pole 30 and the first connector 300 are connected, and ensure the stability of the energy storage device 1000 during the manufacturing process.

[0135] In addition, along the Z-axis direction, the first top surface 375 of the first convex bump 374 is flush with the bottom wall of the first recessed groove 35, so as to prevent the weld seam generated when the first convex bump 374 and the first pole 30 are welded from protruding from the first top surface 321 of the first flange 32, and to prevent a virtual weld between the first convex bump 374 and the first pole 30. It can be understood that the first recessed groove 35 is provided on the first pole 30, which not only reduces the height required for welding the first convex bump 374 and the first pole 30, thereby reducing the manufacturing difficulty and manufacturing cost of the first connector 300, but also accommodates the weld seam in the first recessed groove 35, thereby improving the appearance of the energy storage device 1000.

[0136] The first adapter portion 370 of the first connector 300 is spaced apart from the first main body 31 of the first pole 30. That is, the first adapter outer surface 371 of the first adapter portion 370 is spaced apart from the first end surface 311 of the first main body 31, and the gap L is greater than or equal to 0.1 mm and less than or equal to 2 mm. Preferably, the gap L is 0.5 mm. It can be understood that the first adapter portion 370 and the first pole 30 are spaced apart to reduce the risk of assembly failure of the electrode assembly 900 and the end cap assembly 100 caused by errors in the manufacturing process of the energy storage device 1000.

[0137] Along the Z-axis direction, the second bending portion 480 of the second connector 400 extends away from the two second tabs 940. The second adapter portion 470 of the second connector 400 is spaced apart from the second tabs 940 to prevent the heat generated by the second connector 400 during current over-flow from being transferred to the cell body 920 and affecting the performance of the cell body 920.

[0138] The second convex hump 474 of the second connector 400 is inserted into the second pole through hole 44 of the second pole 40, and the second convex hump 474 is welded to the second pole 40 by seam welding and electrically connected. In this embodiment, the shape of the second convex hump 474 and the shape of the second pole through hole 44 are both elliptical, and when the second convex hump 474 is inserted into the second pole through hole 44, the circumference of the elliptical second convex hump 474 is longer than the circumference of the circular second convex hump 474, so the contact area between the second convex hump 474 and the second pole through hole 44 is larger, and after the second convex hump 474 and the second pole 40 are welded and electrically connected, the current flow capacity of the second connector 400 and the second pole 40 is increased, thereby improving the energy efficiency of the energy storage device 1000. At the same time, the elliptical second convex hump 474 cooperates with the elliptical second pole through hole 44 to improve the torsional strength when the second pole 40 and the second connector 400 are connected, thereby ensuring the stability of the energy storage device 1000 during the manufacturing process.

[0139] In addition, along the Z-axis direction, the second top surface 475 of the second convex bump 474 is flush with the bottom wall of the second recessed groove 45, so as to prevent the weld seam generated when the second convex bump 474 and the second pole 40 are welded from protruding from the second top surface 421 of the second flange 42, and to prevent a cold weld between the second convex bump 474 and the second pole 40. It can be understood that the second pole 40 is provided with the second recessed groove 45, which not only reduces the height required for welding the second convex bump 474 and the second pole 40, thereby reducing the manufacturing difficulty and manufacturing cost of the second connector 400, but also accommodates the weld seam in the second recessed groove 45, thereby improving the appearance of the energy storage device 1000.

[0140] The second adapter portion 470 of the second connector 400 is spaced apart from the second main body 41 of the second pole 40. That is, the second adapter outer surface 471 of the second adapter portion 470 is spaced apart from the second end surface 411 of the second main body 41, and the gap K is greater than or equal to 0.1 mm and less than or equal to 2 mm. Preferably, the gap K is 0.5 mm. It can be understood that the second adapter portion 470 and the second pole 40 are spaced apart to reduce the risk of assembly failure of the electrode assembly 900 and the end cap assembly 100 caused by errors in the manufacturing process of the energy storage device 1000.

[0141] The insulating film 500 may be made of, but not limited to, at least one of Mylar, polyethylene (PE), polypropylene (PP), polyester, etc. The present application embodiment does not limit this. The insulating film 500 wraps around and around the bottom of the electrode assembly 900 and is connected to the edge of the lower plastic 20 to separate and insulate the electrode assembly 900 from the housing 200 to prevent the electrode assembly 900 from short-circuiting.

[0142] Along the Z-axis direction, the support member 600 is installed at one end of the electrode assembly 900 facing away from the end cap assembly 100, and is separated from the electrode assembly 900 by the insulating film 500. The support member 600 supports the electrode assembly 900 to prevent the electrode assembly 900 from being separated from the end cap 10 due to gravity, and ensures the stability of the first electrode tab 930 and the first connector 300, and the stability of the second electrode tab 940 and the second connector 400.

[0143] Since the housing 200 is made of metal, the periphery and bottom of the housing 200 are wrapped with an outer film 700. The outer film 700 is made of insulating material to separate and insulate the housing 200 from the external environment. At the same time, the outer film 700 can also protect the appearance of the housing 200 to prevent the appearance of the housing 200 from being scratched and affecting the use of the housing 200.

[0144] In addition, the outer film 700 also covers the edge of the first surface 111 of the end cap 10 , which not only ensures the adhesion stability between the outer film 700 and the outer shell 200 , but also covers the weld between the outer shell 200 and the end cap 10 , thereby improving the appearance of the energy storage device 1000 .

[0145] Along the Z-axis direction, the protective member 800 is attached to the first surface 111 of the end cap 10 and completely covers the outer film 700 connected to the edge of the end cap 10 to protect the appearance of the end cap 10 .

[0146] In addition, the protection member 800 is made of insulating material to separate and insulate the end cover 10 from the external environment.

[0147] Please refer to Fig.10 and Fig.11 , Fig.10 for Figure 3 The schematic diagram of the structure of the second embodiment of the end cover assembly in the energy storage device shown in FIG. Fig.11 for Fig.10 The structure schematic diagram of the end cover assembly shown in another angle.

[0148] With the above Figure 5 , Figure 6 and Figure 7 The end cap assembly 100 shown in the first embodiment is different in that, in this embodiment, the structure of the end cap 10 and the structure of the lower plastic 20 are respectively different from the structure of the end cap 10 and the structure of the lower plastic 20 in the first embodiment described above. In this embodiment, the end cap 10 further includes a reinforcing protrusion 114 and a plurality of reinforcing recesses 115. The reinforcing protrusion 114 is arranged around the periphery of the protective sheet 93. The reinforcing protrusion 114 is used to improve the rigidity of the end cap 10. The plurality of reinforcing recesses 115 are arranged in parallel along the length direction of the end cap 10 and are arranged at intervals along the width direction of the end cap 10. The plurality of reinforcing recesses 115 are respectively located on both sides of the protective sheet 93 along the width direction of the end cap 10. The plurality of reinforcing recesses 115 are all long strip structures. The extension direction of the plurality of reinforcing recesses 115 is consistent with the length direction of the end cap 10. The length of the plurality of reinforcing recesses 115 is greater than the width of the protective sheet 93. The reinforcing recesses 115 are used to further improve the rigidity of the end cap 10. Exemplarily, the number of reinforcing recesses 115 is four. Two of the reinforcing recesses 115 are located on one side of the reinforcing protrusion 114 in the width direction, and the other two of the reinforcing recesses 115 are located on the other side of the reinforcing protrusion 114 in the width direction.

[0149] Combination Fig.11 , Fig.12 and Fig.13 , Fig.12 for Fig.10 The exploded structural diagram of the end cap assembly shown in FIG. Fig.13 for Fig.11Schematic diagram of the exploded structure of the end cover assembly shown. In this embodiment, the lower plastic 20 also includes a plurality of avoidance portions 27. The plurality of avoidance portions 27 are all recessed in the upper surface 211 of the lower plastic 20, and are recessed in the direction of the lower surface 212. Along the Z-axis direction, the avoidance portions 27 are arranged corresponding to the reinforcing recesses 115. The plurality of avoidance portions 27 are arranged in parallel along the length direction of the lower plastic 20, and are arranged at intervals along the width direction of the lower plastic 20. The extension direction of the plurality of avoidance portions 27 is consistent with the length direction of the lower plastic 20. The plurality of avoidance portions 27 are all strip structures. Each avoidance portion 27 crosses the explosion-proof fence 91 and is connected to the explosion-proof fence 91.

[0150] Combination Fig.14 and Fig.15 , Fig.14 for Fig.12 The schematic diagram of the cross-sectional structure of the end cover in the end cover assembly shown in FIG. Fig.15 for Fig.14 Another cross-sectional schematic diagram of the end cover is shown.

[0151] In this embodiment, the thickness D of the end cover body 11 is thinned to be greater than or equal to 1.5 mm and less than or equal to 1.8 mm. The end cover 10 also includes an inner recess 113. The inner recess 113 is recessed in the second surface 112 of the end cover body 11, and the inner recess 113 is recessed from the second surface 112 to the first surface 111 and forms a reinforcing convex portion 114. The reinforcing convex portion 114 is convexly arranged on the first surface 111. The reinforcing convex portion 114 is formed by stamping the end cover 10 from one side of the second surface 112 to one side of the first surface 111. The pressure relief hole 16 of the end cover 10 runs through both sides of the reinforcing convex portion 114 and the inner recess 113 in the thickness direction, the first annular groove 17 is recessed in the reinforcing convex portion 114, and the second annular groove 18 is located in the inner recess 113. It can be understood that the reinforcing convex portion 114 is arranged around the periphery of the first annular groove 17, and the inner recess 113 is arranged around the periphery of the second annular groove 18. In this embodiment, the number of the inner concave portion 113 and the reinforcing convex portion 114 is one. The shapes of the inner concave portion 113 and the reinforcing convex portion 114 are both elliptical. Along the Z-axis direction, the thickness S of the reinforcing convex portion 114 (i.e., the straight-line distance between the two opposite surfaces of the reinforcing convex portion 114 and the inner concave portion 113) is equal to the thickness D of the end cover body 11, or the thickness S of the reinforcing convex portion 114 is greater than or equal to 80% of the thickness D of the end cover body 11 and less than or equal to 99% of the thickness D of the end cover body 11.

[0152] The multiple reinforcement recesses 115 of the end cover 10 are all recessed on the first surface 111 of the end cover 10, and the multiple reinforcement recesses 115 are recessed in the direction of the second surface 112, and protrude from the second surface 112 to form an inner convex bump 116. Exemplarily, the number of the inner convex bumps 116 is the same as the number of the reinforcement recesses 115, and the number of the inner convex bumps 116 is four, and each inner convex bump 116 is corresponding to a reinforcement recess 115.

[0153] See again Fig.12 and Fig.13 , the explosion-proof valve sheet 92 and the protection sheet 93 are mounted on the end cover 10, the reinforcing protrusion 114 is arranged around the periphery of the protection sheet 93 and the inner recess 113 is arranged around the periphery of the explosion-proof valve sheet 92, which improves the stability of the explosion-proof valve sheet 92 and the protection sheet 93 when they are exploded by the internal gas of the energy storage device 1000. In addition, the reinforcing recess 115 is located on the outside of the explosion-proof valve sheet 92 and the protection sheet 93, further improving the stability of the explosion-proof valve sheet 92 and the protection sheet 93 when they are exploded by the internal gas of the energy storage device 1000. The end cover 10 and the lower plastic 20 are stacked along the Z-axis direction, and the inner recess 113 of the end cover 10 is opposite to the explosion-proof fence 91. The length of the reinforcing recess 115 of the end cover 10 is greater than the width of the explosion-proof fence 91. Each inner convex bump 116 of the end cover 10 is accommodated in an avoidance portion 27 , which reduces the space occupied by the end cover assembly 100 in the height direction of the energy storage device 1000 , and is beneficial to improving the energy density of the energy storage device 1000 .

[0154] It should be noted that the same contents as those in the first embodiment of the end cap assembly 100 in this embodiment are not described in detail. The assembly relationship between the end cap assembly 100 and other structural components in the energy storage device 1000 in this embodiment is the same as that in the first embodiment, so they are not described in detail.

[0155] The above are only some embodiments and implementation methods of the present application, and the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by any person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An end cap assembly, characterized in that: include: An end cap, comprising an end cap body, the end cap body comprising a first surface, a second surface and an inclined boss, the first surface and the second surface are arranged opposite to each other along the thickness direction of the end cap body, the inclined boss is convexly arranged on the first surface of the end cap body, the inclined boss comprises an inclined peripheral surface and a boss surface, the inclined peripheral surface connects the boss surface and the first surface and surrounds the periphery of the boss surface, the end cap body further comprises a through hole penetrating the second surface and the boss surface; The upper plastic includes a main body section, an extension section and a protruding section, the main body section is connected to the outer periphery of the extension section, the extension section extends along the height direction of the upper plastic, the extension direction of the main body section intersects with the extension direction of the extension section, the extension section encloses an insulating hole, and the protruding section extends from the main body section away from the outer periphery of the extension section, and the extension direction is the same as the extension direction of the main body section; A pole, the pole comprising a flange and a main body, the flange comprising a top surface and a bottom surface, the top surface and the bottom surface are arranged opposite to each other along the thickness direction of the flange, the main body is protruded from the bottom surface and extends in a direction away from the flange; The upper plastic and the pole are mounted on the end cover, the extension section is penetrated through the through hole, the main body is penetrated through the insulating hole and the through hole in sequence, along the axial direction of the through hole, the main body section is located between the bottom surface of the flange and the inclined boss of the end cover body; along the direction in which the protruding section is away from the axis of the through hole, one end of the protruding section away from the through hole protrudes from the inclined peripheral surface and the outer peripheral edge of the flange, and the protruding section is spaced apart from the first surface of the end cover body.

2. The end cap assembly according to claim 1, characterized in that: The protruding section includes an upper arc surface, the upper arc surface faces away from the end cover, and the upper arc surface and the first surface of the end cover are arranged at an angle.

3. The end cap assembly according to claim 2, characterized in that: The protruding section also includes a lower arc surface, which is arranged opposite to the upper arc surface along the thickness direction of the protruding section. The lower arc surface and the inclined peripheral surface form an annular notch with a "<" shape in cross section, and the notch surrounds and faces away from the pole.

4. The end cap assembly according to claim 3, characterized in that: The body segment includes an upper surface and a lower surface, the upper surface and the lower surface are arranged opposite to each other along the thickness direction of the body segment, the upper surface is opposite to and connected to the bottom surface, the upper surface and the bottom surface are both parallel to the first surface, the lower surface is opposite to and connected to the boss surface, and the lower surface and the boss surface are both parallel to the first surface; The width of the upper surface is smaller than the width of the lower surface, the width of the upper curved surface is larger than the width of the lower curved surface, and the angle at which the upper curved surface is inclined relative to the upper surface is smaller than the angle at which the lower curved surface is inclined relative to the lower surface.

5. The end cap assembly according to claim 1, characterized in that: The end cover assembly further includes an explosion-proof valve, and the end cover further includes an inner concave portion and a reinforcing convex portion, wherein the inner concave portion is formed by the second surface being recessed in a direction toward the first surface, and the reinforcing convex portion is formed on the first surface, and the reinforcing convex portion protrudes out of the first surface; The end cover also includes a pressure relief hole, which runs through the reinforcing convex portion along the thickness direction of the end cover. Part of the explosion-proof valve is arranged on the end cover and covers the pressure relief hole.

6. The end cap assembly according to claim 5, characterized in that: The end cap assembly further comprises a lower plastic, wherein the lower plastic and the end cap are stacked along the thickness direction of the end cap assembly; The end cover further includes a first annular groove and a second annular groove, wherein the first annular groove is located in the inner concave portion, and the second annular groove is recessed in the reinforcing convex portion, and the first annular groove and the second annular groove are both arranged around the periphery of the pressure relief hole and are both connected to the hole wall of the pressure relief hole; The explosion-proof valve includes an explosion-proof valve plate, a protective plate and an explosion-proof fence. The explosion-proof valve plate is accommodated in the second annular groove, the protective plate is accommodated in the first annular groove, the protective plate and the explosion-proof valve plate are opposite and spaced apart along the thickness direction of the end cover assembly, the explosion-proof fence is arranged on the lower plastic, and the explosion-proof valve plate is located in the explosion-proof fence.

7. The end cap assembly according to claim 6, characterized in that: The end cover assembly further includes an explosion-proof valve, which includes an explosion-proof valve sheet, a protection sheet and an explosion-proof fence, wherein the explosion-proof fence is arranged on the lower plastic, and the end cover further includes a pressure relief hole, wherein the pressure relief hole is opposite to the explosion-proof fence along the thickness direction of the end cover assembly; The end cover further includes a plurality of reinforcing recesses and a plurality of inner convex bumps, each of the reinforcing recesses is recessed on the first surface and is recessed toward the second surface to form an inner convex bump, a plurality of the inner convex bumps are convexly disposed on the second surface, a plurality of the reinforcing recesses are arranged in parallel along the length direction of the end cover, and are arranged at intervals along the width direction of the end cover, and a plurality of the reinforcing recesses are respectively disposed on both sides of the pressure relief hole along the width direction of the end cover; The extension direction of the reinforced recess is consistent with the length direction of the end cover, and the length of the reinforced recess is greater than the width of the explosion-proof valve fence.

8. The end cap assembly according to claim 7, characterized in that: The lower plastic also includes a plurality of avoidance portions, which are recessed in the first surface and recessed toward the second surface. The plurality of avoidance portions are arranged in parallel along the length direction of the lower plastic and are arranged at intervals along the width direction of the lower plastic. The plurality of avoidance portions all cross the explosion-proof fence and are connected to the explosion-proof fence, and each of the inner convexities is contained in one of the avoidance portions.

9. The end cap assembly according to any one of claims 1 to 8, characterized in that: The flange is an elliptical block, the main body is an elliptical cylinder, and the through hole is an elliptical hole.

10. An energy storage device, characterized in that: The end cap assembly according to any one of claims 1 to 9 further comprises: a housing, including an opening; An electrode assembly, comprising a battery cell, wherein the battery cell comprises a battery cell body and a tab, the battery cell body comprises an upper end surface and a lower end surface, the upper end surface and the lower end surface are arranged opposite to each other along the height direction of the battery cell body, and the tab extends out of the upper end surface; and Connectors; The end cap assembly is mounted on one end of the electrode assembly facing the opening and sealed at the opening. The connecting piece is located between the electrode assembly and the lower plastic. The connecting piece connects and conducts the pole and the pole ear.

11. An electrical device, characterized in that: It comprises the energy storage device as claimed in claim 10, wherein the energy storage device is used to supply power to the electrical equipment.

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