End cover assembly, energy storage device and electrical equipment

Abstract

The present application provides an end cap assembly, an energy storage device and an electrical device, which are used to improve the sealing performance of the end cap assembly. The end cap assembly includes an end cap and a pole assembly, the end cap is provided with a mounting hole, the mounting hole penetrates the end cap along the thickness direction of the end cap, the pole assembly includes a pole, a sealing ring and an upper plastic, the pole includes a column part, the column part is inserted into the mounting hole, the column part is provided with at least one first annular structure, the first annular structure is provided on the circumference of the column part and is arranged around the column part, the sealing ring is sleeved on the column part and covers the first annular structure and is clamped between the column part and the hole wall of the mounting hole, the upper plastic is sleeved on the column part and connected between the column part and the end cap.

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] Rechargeable battery, also known as 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. As the demand for secondary batteries gradually increases, people's requirements for their performance in various aspects are also getting higher and higher, especially for the energy density per unit volume of the battery. The sealing performance of the battery's end cap assembly is an important parameter that affects the reliability of battery use. The current end cap assembly mainly uses a sealing ring mounted on the pole to achieve the seal between the pole and the end cap, and the sealing performance of the end cap assembly is poor. Summary of the invention

[0003] The present application provides an end cover assembly, an energy storage device and an electrical device, which are used to improve the sealing performance of the end cover assembly.

[0004] In the first aspect, the present application provides an end cap assembly for use in an energy storage device. The end cap assembly includes an end cap and a pole assembly, the end cap is provided with a mounting hole, the mounting hole penetrates the end cap along the thickness direction of the end cap, the pole assembly includes a pole, a sealing ring and an upper plastic, the pole includes a column portion, the column portion is provided with an annular groove, the opening of the annular groove is located on the outer peripheral surface of the column portion, the annular groove is arranged around the periphery of the column portion, the column portion is penetrated by the mounting hole, the column portion is provided with at least one first annular structure, the first annular structure is arranged on the peripheral surface of the column portion and arranged around the column portion, the sealing ring is sleeved on the column portion, covers the first annular structure, and is clamped between the end cap and the pole, the upper plastic is sleeved on the column portion, covers the groove wall of the annular groove, and is connected between the column portion and the end cap.

[0005] There are a plurality of the first annular structures, and the plurality of the first annular structures are arranged in sequence and at equal intervals along the height direction of the column portion.

[0006] Wherein, the first annular structure is in a thread shape or a line shape.

[0007] Wherein, each of the first annular structures is provided with at least one first notch along the circumference of the column portion.

[0008] The first notches of every two adjacent first annular structures are arranged opposite to each other, or the first notches of every two adjacent first annular structures are arranged in a staggered manner.

[0009] Wherein, the width of the first annular structure is between 0.02 mm and 0.45 mm.

[0010] Wherein, the pole further comprises a flange portion, the flange portion is fixedly connected to one side of the column portion, the flange portion is provided with at least one second annular structure, the second annular structure is provided on the surface of the flange portion facing the column portion, and is arranged around the column portion;

[0011] The sealing ring abuts against a surface of the flange portion facing the column portion and covers at least a portion of the second annular structure.

[0012] Among them, when there are multiple second annular structures, along the direction from the center to the edge of the surface of the flange portion facing the column portion, the multiple first annular structures are arranged in sequence at equal intervals and cover the surface of the flange portion facing the column portion.

[0013] Wherein, each of the second annular structures is provided with at least one second notch arranged along the circumference of the column portion.

[0014] The second notches of every two adjacent second annular structures are arranged opposite to each other, or the second notches of every two adjacent second annular structures are arranged in a staggered manner.

[0015] Wherein, the width of the second annular structure is smaller than the width of the first annular structure.

[0016] Wherein, the width of the second annular structure is between 0.01 mm and 0.35 mm.

[0017] The upper plastic is provided with a convex ring and a convex rib, the convex ring is provided on the surface of the upper plastic facing the end cover and is arranged around the column portion, at least part of the convex ring is located in the mounting hole, and is provided between the hole wall of the mounting hole and the column portion, and abuts against a part of the surface of the sealing ring away from the flange portion, the convex rib is provided on the surface of the convex ring facing the sealing member and is arranged around the column portion, and the convex rib is located between the inner side surface of the sealing ring and the outer peripheral surface of the column portion.

[0018] The flange portion is further provided with at least one third annular structure, and the third annular structure is provided on a surface of the flange portion which is away from the column portion.

[0019] There are multiple third annular structures, and the multiple third annular structures are cocentric and cover the surface of the flange portion away from the column portion.

[0020] The column portion is provided with a step groove, the opening of the step groove is located on the surface of the column portion away from the flange portion, the step groove is arranged around the edge of the column portion and passes through the outer peripheral surface of the column portion;

[0021] The upper plastic is also provided with a step ring, which is fixedly connected to the side of the upper plastic facing the pole and is located on the side of the upper plastic away from the end cover. The step ring partially covers the step groove, and there is a gap between the inner side surface of the step ring and the side wall surface of the step groove.

[0022] Wherein, the mounting hole includes a mounting hole portion and a countersunk hole portion, the countersunk hole portion is located on one side of the mounting hole portion and is connected to the mounting hole portion, the cross-sectional area of ​​the countersunk hole portion is larger than the cross-sectional area of ​​the mounting hole portion, the hole wall of the countersunk portion includes a plurality of guide portions, the plurality of guide portions are arranged at intervals around the mounting portion, and the upper plastic covers the plurality of guide portions.

[0023] Wherein, each of the guide portions is spaced apart from the mounting hole portion.

[0024] Wherein, the thickness of the guide portion gradually decreases along the direction from the countersunk hole portion to the mounting hole portion.

[0025] The mounting hole portion includes a mounting part and a connecting part, the connecting part connects the mounting part and the countersunk hole portion, and a cross section of the connecting part gradually decreases in a direction from the countersunk hole portion to the mounting hole portion.

[0026] In a second aspect, the present application further provides an energy storage device, comprising a shell and any of the end cover assemblies described above, wherein the end cover assembly is installed on one side of the shell.

[0027] In a third aspect, the present application further provides an electrical device, comprising the energy storage device described above, wherein the energy storage device supplies power to the electrical device.

[0028] In the end cap assembly shown in the present application, the column portion of the pole is provided with a first annular structure, and the first annular structure is arranged around the column portion. The design of the first annular structure can increase the contact area between the column portion and the sealing ring, which helps to improve the sealing performance of the sealing ring. Moreover, when the pole is cut and milled, the first annular structure can be formed at one time by controlling the depth of the cutter head, which can reduce the processing steps of the pole and help reduce the processing cost of the pole. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solution of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be described below.

[0030] Figure 1 is an application scenario diagram of the energy storage system provided in the embodiment of the present application;

[0031] Figure 2 yes Figure 1 A schematic diagram of the structure of the energy storage device in the energy storage system shown;

[0032] Figure 3 yes Figure 2 A schematic diagram of the structure of the end cover assembly in the energy storage device shown;

[0033] Figure 4 yes Figure 3 The structure schematic diagram of the end cover assembly after being cut along AA;

[0034] Figure 5 yes Figure 3 An exploded structural diagram of the end cap assembly shown;

[0035] Figure 6 yes Figure 5 A schematic diagram of the structure of the lower plastic in the end cover assembly shown;

[0036] Figure 7 yes Figure 5 A schematic diagram of the structure of an end cap in the end cap assembly shown;

[0037] Figure 8 yes Figure 7 The structure diagram of the end cover after being cut open along BB is shown;

[0038] Fig. 9 yes Figure 7 The cross-sectional structure diagram of the end cover after being cut along CC;

[0039] Fig.10 yes Figure 5 A schematic diagram of the exploded structure of the positive electrode assembly in the end cap assembly shown;

[0040] Fig.11a yes Fig.10 A schematic structural diagram of a first pole in the positive electrode assembly shown in the first embodiment;

[0041] Fig.11b yes Fig.11a The schematic diagram of the structure of the first pole shown is at another angle;

[0042] Fig.12 yes Fig.11a The schematic diagram of the structure of the first pole after being cut along DD;

[0043] Fig.13 yes Fig.10 A schematic structural diagram of the first pole in the positive electrode assembly shown in the second embodiment;

[0044] Fig.14 yes Fig.10 A schematic structural diagram of the first pole in the positive electrode assembly shown in the third embodiment;

[0045] Fig.15 yes Fig.10 A schematic diagram of the structure of the first upper plastic in the positive electrode assembly shown at another angle;

[0046] Fig.16 yes Fig.10 A schematic diagram of the structure of the first upper plastic in the positive electrode assembly after being cut open along EE;

[0047] Fig.17 yes Figure 5 Schematic diagram of the exploded structure of the negative electrode assembly in the end cap assembly shown.

[0048] The names corresponding to the reference numerals in the figure are: energy storage system 1000, light energy conversion device 400, wind energy conversion device 300, power grid 200, energy storage device 100, shell 110, end cover assembly 120, lower plastic 10, end cover 20, explosion-proof valve 30, protective sheet 40, seal 50, pole assembly 60, positive electrode assembly 70, negative electrode assembly 80, positive electrode lower plastic 11, negative electrode lower plastic 12, first assembly boss 111, first through hole 112, liquid inlet hole 113, fence part 121, second assembly boss 122, second through hole 123, air vent 124, mounting boss 21, first mounting boss 22, second mounting boss 23, avoidance groove 201, explosion-proof hole 202, injection hole 203, mounting hole 204, first avoidance groove 205, second avoidance groove 206, first mounting hole 207, second mounting hole 208, first mounting hole portion 2071, first countersunk hole portion 2072, first protrusion 24, first guide portion 241, first guide surface 242, first mounting portion 2073, first connecting portion 2074, second mounting hole portion 2081, second countersunk hole portion 2082, first pole 71, first sealing ring 72, first upper plastic 73, first adapter 74, first column portion 711, first flange portion 712, first step groove 713, first annular groove 714, first annular structure 715, second annular structure 716, third annular structure 719, first notch 717, second notch 718, first convex ring 731, first convex rib 732, first step ring 733, first identification groove 734, second pole 81, second sealing ring 82, second upper plastic 83, second adapter 84 and second identification groove 834. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0050] Since the energy people need is highly temporal and spatial, in order to rationally use 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 based on future application needs. As we all know, in order to achieve the goal of carbon neutrality, the main way to generate green electricity is to develop green energy such as photovoltaics and wind power to replace fossil energy.

[0051] At present, the generation of green electricity generally relies on photovoltaics, wind power, and hydropower, etc. However, wind and solar energy generally have problems of strong intermittency and large volatility, which will cause instability in the power grid, insufficient electricity during peak hours, and too much electricity during valley hours. Unstable voltage will also cause damage to electricity. Therefore, insufficient electricity demand or insufficient grid acceptance capacity may cause the problem of "abandoning wind and solar power". To solve these problems, we must rely on energy storage. That is, converting electrical energy into other forms of energy through physical or chemical means and storing it, and converting energy into electrical energy and releasing it when needed. In simple terms, energy storage is like a large "power bank". When photovoltaic and wind energy are sufficient, electrical energy is stored and the stored electricity is released when needed.

[0052] Taking electrochemical energy storage as an example, this solution provides an energy storage device, which has a group of chemical batteries in it. The chemical elements in the chemical batteries are mainly used 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 and solar energy is stored in chemical batteries. When the use of external electricity reaches its peak, the stored electricity is released for use, or transferred to places where electricity is scarce for use.

[0053] At present, energy storage (i.e. energy storage) has a wide range of application scenarios, including power generation side energy storage, grid side energy storage, renewable energy grid-connected energy storage, base station side energy storage and user side energy storage. The corresponding types of energy storage devices include:

[0054] (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;

[0055] (2) The main operating mode of small and medium-sized energy storage cabinets used in industrial and commercial energy storage scenarios (banks, shopping malls, etc.) on the user side and small household energy storage boxes used in home energy storage scenarios on the user side is "peak shaving and valley filling". Since there is a large price difference in electricity charges at peak and valley locations according to electricity demand, after users have energy storage equipment, in order to reduce costs, they usually charge the energy storage cabinets / boxes during the low electricity price period; during the peak electricity price period, the electricity in the energy storage equipment is discharged for use to achieve the purpose of saving electricity bills. In addition, in remote areas and areas prone to natural disasters such as earthquakes and hurricanes, the existence of household energy storage devices is equivalent to users providing themselves and the power grid with backup power, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0056] See also Figure 1 , Figure 1 It is an application scenario diagram of the energy storage system 1000 provided in an embodiment of the present application.

[0057] The energy storage system 1000 includes a light energy conversion device 400, a wind energy conversion device 300, a power grid 200 and an energy storage device 100. Among them, the energy storage device 100 can be used as an energy storage cabinet installed outdoors. Exemplarily, the light energy conversion device 400 can be a photovoltaic panel, and the wind energy conversion device 300 can be a power generation windmill. During the period of low electricity prices, the light energy conversion device 400 can convert solar energy into electrical energy, and the wind energy conversion device 300 can convert wind energy into electrical energy. The energy storage device 100 can store the electrical energy converted by the light energy conversion device 400 and the wind energy conversion device 300, and can also supply electrical energy to the power grid 200 during the peak period of electricity prices. Among them, the electrical energy of the power grid can be transmitted through cables.

[0058] There may be multiple energy storage devices 100, and the multiple energy storage devices 100 are connected in series and / or in parallel. In addition, the energy storage system 1000 may also include an energy storage box, which is used to accommodate multiple energy storage devices. It should be noted that in this embodiment, "multiple" means more than two, and similar descriptions in the following text can be understood in the same way.

[0059] It is understandable that the energy storage device 100 may include but is not limited to a single cell, a battery module, a battery pack, a battery system, etc. When the energy storage device 100 is a single cell, it may be a square battery. When the energy storage device 100 is a battery module, the energy storage device 100 may include a plurality of single cells and a plurality of connecting plates, each connecting plate being electrically connected between two single cells. The connecting plate may be an aluminum plate. The single cells may be connected in series and / or in parallel through a plurality of connecting plates.

[0060] See also Figure 2 , Figure 2 yes Figure 1A schematic structural diagram of the energy storage device 100 in the energy storage system 1000 is shown.

[0061] In this embodiment, the energy storage device 100 is a square battery. The energy storage device 100 includes a housing 110, an electrode assembly (not shown) and an end cap assembly 120. The housing 110 has an opening (not shown), and the housing 110 is provided with a receiving cavity (not shown), and the receiving cavity contains an electrolyte. The electrode assembly is received in the receiving cavity and immersed in the electrolyte. The end cap assembly 120 is installed on one side of the housing 110 and closes the opening.

[0062] See also Figures 3 to 5 , Figure 3 yes Figure 2 The schematic diagram of the structure of the end cover assembly 120 in the energy storage device 100 is shown. Figure 4 yes Figure 3 The schematic diagram of the structure of the end cover assembly 120 after being cut along AA is shown. Figure 5 yes Figure 3 The schematic diagram of the exploded structure of the end cap assembly 120 is shown. Herein, "cut along AA" means cutting along the plane where the AA line is located, and similar descriptions in the following text can be understood in the same way.

[0063] The end cap assembly 120 includes a lower plastic 10, an end cap 20, an explosion-proof valve 30, a protective sheet 40, a seal 50 and two pole assemblies 60. The end cap 20 is installed on one side of the thickness direction of the lower plastic 10 (i.e., the thickness direction D1 of the end cap assembly 120). The explosion-proof valve 30, the protective sheet 40, the seal 50 and the two pole assemblies 60 are all installed on the end cap 20. Along the thickness direction D1 of the end cap assembly 120, the explosion-proof valve 30 and the protective sheet 40 are arranged opposite to each other. The seal 50 is located on one side of the protective sheet 40 and is spaced apart from the protective sheet 40. Along the length direction D2 of the end cap assembly 120, the two pole assemblies 60 are respectively located on opposite sides of the protective sheet 40. Among them, the two pole assemblies 60 are respectively a positive electrode assembly 70 and a negative electrode assembly 80. The positive electrode assembly 70 and the seal 50 are located on the same side of the protection sheet 40 and are located on the side of the seal 50 away from the protection sheet 40 and are spaced apart from the seal 50. The negative electrode assembly 80 is located on the side of the protection sheet 40 away from the seal 50 and is spaced apart from the protection sheet 40.

[0064] See also Figure 4 and Figure 6 , Figure 6 yes Figure 5 The schematic diagram of the structure of the lower plastic 10 in the end cover assembly 120 is shown.

[0065] In this embodiment, the lower plastic 10 is made of plastic. The lower plastic 10 includes a positive electrode lower plastic 11 and a negative electrode lower plastic 12. Along the length direction of the lower plastic 10 (i.e., the length direction D2 of the end cap assembly 120), the positive electrode lower plastic 11 and the negative electrode lower plastic 12 are arranged in sequence. It should be noted that in the embodiment of the present application, the direction from the positive electrode lower plastic 11 to the negative electrode lower plastic 12 is the length direction D2 of the end cap assembly 120. In some other embodiments, the direction from the negative electrode lower plastic 12 to the positive electrode lower plastic 11 can also be the length direction D2 of the end cap assembly 120. The embodiment of the present application does not make specific restrictions on this.

[0066] A first assembly boss 111 is convexly provided on the surface of the positive electrode lower plastic 11 facing the end cover 20, and the first assembly boss 111 is located on the side of the positive electrode lower plastic 11 away from the negative electrode lower plastic 12. Exemplarily, the first assembly boss 111 is a square boss. The positive electrode lower plastic 11 is also provided with a first through hole 112 and a liquid inlet hole 113, and the first through hole 112 and the liquid inlet hole 113 both penetrate the positive electrode lower plastic 11 along the thickness direction of the positive electrode lower plastic 11 (i.e., the thickness direction D1 of the end cover assembly 120). Specifically, the opening of the first through hole 112 is located on the surface of the first assembly boss 111 facing the end cover 20, and the liquid inlet hole 113 is located on the side of the first assembly boss 111 facing the negative electrode lower plastic 12, and is spaced apart from the first assembly boss 111. Exemplarily, the first through hole 112 is a circular hole.

[0067] The negative electrode lower plastic 12 includes a fence portion 121, and the fence portion 121 is located on the side of the negative electrode lower plastic 12 close to the positive electrode lower plastic 11. A second assembly boss 122 is protruding from the surface of the negative electrode lower plastic 12 facing the end cover 20, and the second assembly boss 122 is located on the side of the negative electrode lower plastic 12 away from the positive electrode lower plastic 11. Exemplarily, the second assembly boss 122 is a square boss.

[0068] The negative electrode lower plastic 12 is also provided with a second through hole 123 and a plurality of air holes 124, and the second through hole 123 and the plurality of air holes 124 all penetrate the negative electrode lower plastic 12 along the thickness direction of the negative electrode lower plastic 12 (i.e., the thickness direction D1 of the end cap assembly 120). Specifically, the opening of the second through hole 123 is located on the surface of the second assembly boss 122 facing the end cap 20. Exemplarily, the second through hole 123 is a circular hole. The plurality of air holes 124 are all located in the fence portion 121, and all penetrate the fence portion 121 along the thickness direction of the fence portion 121 (i.e., the thickness direction D1 of the end cap assembly 120). Specifically, the plurality of air holes 124 are arranged at intervals from each other. Among them, the plurality of air holes 124 are arranged in an array. Exemplarily, the plurality of air holes 124 are all square holes.

[0069] Please also read Figure 7 and Figure 8 , Figure 7 yes Figure 5 The schematic diagram of the structure of the end cover 20 in the end cover assembly 120 is shown. Figure 8 yes Figure 7 The structure diagram of the end cover 20 after being cut open along BB is shown.

[0070] In this embodiment, the end cap 20 is a plain aluminum sheet made of aluminum. The surface of the end cap 20 away from the lower plastic 10 is provided with two mounting bosses 21, and the two mounting bosses 21 are respectively a first mounting boss 22 and a second mounting boss 23. Specifically, the surface of the end cap 20 away from the positive electrode lower plastic 11 is provided with a first mounting boss 22, and the surface of the end cap 20 away from the negative electrode lower plastic 12 is provided with a second mounting boss 23. Among them, along the length direction of the end cap 20 (i.e., the length direction D2 of the end cap assembly 120), the first mounting boss 22 and the second mounting boss 23 are respectively located on opposite sides of the end cap 20. Exemplarily, the first mounting boss 22 and the second mounting boss 23 are both circular bosses.

[0071] The end cover 20 is provided with two avoidance grooves 201, an explosion-proof hole 202, a liquid injection hole 203 and two mounting holes 204. The openings of the two avoidance grooves 201 are both located on the surface of the end cover 20 facing the lower plastic 10, and the two avoidance grooves 201 are both recessed from the surface of the end cover 20 facing the lower plastic 10 to the surface of the end cover 20 away from the lower plastic 10. Along the length direction of the end cover 20 (i.e., the length direction D2 of the end cover assembly 120), the two avoidance grooves 201 are respectively located on opposite sides of the end cover 20, and are respectively arranged corresponding to the two mounting bosses 21. Among them, the two avoidance grooves 201 are respectively the first avoidance groove 205 and the second avoidance groove 206. The first avoidance groove 205 is arranged corresponding to the first mounting boss 22, and is used to avoid the first assembly boss 111. The second avoidance groove 206 is arranged corresponding to the second mounting boss 23, and is used to avoid the second assembly boss 122. Exemplarily, the first avoidance groove 205 is a square groove matched with the first assembly boss 111 , and the second avoidance groove 206 is a square groove matched with the second assembly boss 122 .

[0072] It should be noted that the first avoidance groove 205 and the second avoidance groove 206 can both be formed by a stamping process, and the end cover 20 is stamped from the surface of the end cover 20 toward the surface of the end cover 20 away from the lower plastic 10 to form the first avoidance groove 205 and the second avoidance groove 206, so as to simultaneously form the first mounting boss 22 and the second mounting boss 23.

[0073] The explosion-proof hole 202, the injection hole 203 and the two mounting holes 204 all penetrate the end cover 20 along the thickness direction of the end cover 20 (i.e., along the thickness direction D1 of the end cover assembly 120). Specifically, the explosion-proof hole 202 is located in the middle of the end cover 20. Among them, along the thickness direction of the end cover assembly 120, the explosion-proof hole 202 is arranged opposite to the fence part 121. The explosion-proof hole 202 can connect the inside and the outside of the energy storage device 100 through the fence part 121. Exemplarily, the explosion-proof hole 202 is an elliptical hole.

[0074] It should be noted that the directional words such as “outside” and “inside” mentioned in the description of the end cap assembly 120 in the embodiment of the present application are all in Figure 2 The energy storage device 100 is described in terms of its orientation, with the side facing away from the exterior of the housing 110 being referred to as “outside” and the side facing the interior of the housing 110 being referred to as “inside”. Similar descriptions hereinbelow may be understood in the same manner.

[0075] Along the length direction D2 of the end cap 20, the injection hole 203 is located on the side of the explosion-proof hole 202 facing the first mounting boss 22, and is spaced apart from the explosion-proof hole 202 and the first mounting boss 22. The injection hole 203 is connected to the liquid inlet hole 113. The electrolyte can be injected into the housing 110 (such as the electrolyte) through the injection hole 203 of the end cap 20 and the liquid inlet hole 113 of the positive lower plastic 11 in sequence. Figure 2 As shown in the figure, the receiving cavity 203 is provided to realize the perfusion of the electrolyte of the energy storage device 100. Exemplarily, the injection hole 203 is a circular hole.

[0076] Along the length direction D2 of the end cover 20, the two mounting holes 204 are respectively located on opposite sides of the explosion-proof hole 202, and are spaced apart from the explosion-proof hole 202. The opening of each mounting hole 204 is located on the surface of a mounting boss 21 away from the lower plastic 10. Specifically, the two mounting holes 204 are respectively a first mounting hole 207 and a second mounting hole 208. The opening of the first mounting hole 207 is located on the surface of the first mounting boss 22 away from the positive lower plastic 11, and the opening of the second mounting hole 208 is located on the surface of the second mounting boss 23 away from the negative lower plastic 12. Among them, the first mounting hole 207 is connected to the first through hole 112, and the second mounting hole 208 is connected to the second through hole 123.

[0077] It should be noted that, in the present embodiment, the structures of the first mounting hole 207 and the second mounting hole 208 are the same. The structure of the two mounting holes 204 will be described below taking the structure of the first mounting hole 207 as an example. To avoid redundancy, the structure of the second mounting hole 208 will not be described repeatedly. The structures of the first mounting hole 204 and the second mounting hole 208 can refer to the relevant description of the mounting hole 204 below.

[0078] See also Figure 8 and Fig. 9 , Fig. 9 yes Figure 7 The cross-sectional structure diagram of the end cover 20 is shown after being cut along CC.

[0079] The first mounting holes 207 each include a first mounting hole portion 2071 and a first countersunk hole portion 2072. Along the thickness direction of the end cover 20, the first countersunk hole portion 2072 is located on one side of the first mounting hole portion 2071 and is connected to the first mounting hole portion 2071. Specifically, the opening of the first countersunk hole portion 2072 is located on the surface of the first mounting boss 22 away from the positive lower plastic 11. Among them, the cross-sectional area of ​​the first countersunk hole portion 2072 is larger than the cross-sectional area of ​​the first mounting hole portion 2071. Exemplarily, the first mounting hole portion 2071 and the first countersunk hole portion 2072 are both circular holes, and the aperture of the first countersunk hole portion 2072 is larger than the aperture of the first mounting hole portion 2071.

[0080] In this embodiment, the first countersunk hole portion 2072 is spline-shaped. The hole wall of the first countersunk hole portion 2072 is provided with a plurality of first protrusions 24, and the plurality of first protrusions 24 are arranged at intervals around the first mounting hole portion 2071, and are all arranged at intervals from the first mounting hole portion 2071. Among them, the distance between each first protrusion 24 and the first mounting hole portion 2071 is w1, and w1 is between 0.15mm and 0.65mm. Exemplarily, w1 is 0.15mm. Among them, the "mm" mentioned in this application is the abbreviation of the length unit millimeter.

[0081] In this embodiment, each first protrusion 24 includes a first guide portion 241 facing the center of the first countersunk hole portion 2072, and the thickness of the first guide portion 241 gradually decreases in the direction from the first countersunk hole portion 2072 to the first mounting hole portion 2071. Exemplarily, the first guide portion 241 is pointed, and the tip of the first guide portion 241 faces the center of the first countersunk hole portion 2072. The first guide portion 241 includes a first guide surface 242 facing away from the first mounting hole portion 2071, and the angle between the first guide surface 242 and the surface of the end cover 20 facing away from the lower plastic 10 is θ1, and θ1 is between 2 degrees and 15 degrees. Exemplarily, θ1 is 5 degrees.

[0082] The first mounting hole portion 2071 includes a first mounting portion 2073 and a first connecting portion 2074. The first mounting portion 2073 is located on the side of the first countersunk hole portion 2072 facing the lower plastic 10 and is spaced apart from the first countersunk hole portion 2072. The first connecting portion 2074 is located between the first mounting portion 2073 and the first countersunk hole portion 2072 and connects the first mounting portion 2073 and the first countersunk hole portion 2072. In the direction from the first countersunk hole portion 2072 to the first mounting portion 2073, the cross-sectional area of ​​the first connecting portion 2074 gradually decreases. Exemplarily, the hole wall surface of the first connecting portion 2074 is an arc surface.

[0083] It should be noted that in the positive electrode assembly 70, during the injection molding process of the first upper plastic, a flow channel can be formed between the hole wall of the first mounting hole 207 and the first pole, and the first guide surface 242 of the first guide portion 241 and the hole wall surface of the first connecting portion 2074 can guide the plastic to flow smoothly, so that the gap between the hole wall of the first mounting hole 207 and the first pole can form a smooth flow channel. The design of the first guide surface 242 of the first guide portion 241 and the hole wall surface of the first connecting portion 2074 can not only increase the width of the gap between the first pole and the end cover 20, prevent the gap between the first pole and the end cover 20 from being too narrow to cause air entrapment, but also increase the thickness of the first upper plastic after molding, avoid the first upper plastic from being too weak, thereby helping to improve the structural strength of the first upper plastic.

[0084] See also Figure 7 and Figure 8 The second mounting hole 208 includes a second mounting hole portion 2081 and a second countersunk hole portion 2082. Along the thickness direction of the end cover 20, the second countersunk hole portion 2082 is located on one side of the second mounting hole portion 2081 and is connected to the second mounting hole portion 2081. The second mounting hole portion 2081 has the same structure as the first mounting hole portion 2071, the second countersunk hole portion 2082 has the same structure as the first countersunk hole portion 2072, and the matching relationship between the second mounting hole portion 2081 and the second countersunk hole portion 2082 is the same as the matching relationship between the first mounting hole portion 2071 and the first countersunk portion 2072. The details will not be repeated here. The structures of the second mounting hole portion 2081 and the first mounting hole portion 2071, and the matching relationship between the second mounting hole portion 2081 and the first mounting hole portion 2071 can all refer to the above-mentioned description of the first mounting hole portion 2071 and the first countersunk hole portion 2072.

[0085] It should be noted that, in the negative electrode assembly 80, during the process of plastic injection molding on the negative electrode, the gap between the hole wall of the second mounting hole 208 and the negative electrode column can form a flow channel, and the second guide surface of the second guide part and the hole wall surface of the second connecting part can guide the plastic to flow smoothly, so that the gap between the hole wall of the second mounting hole 208 and the negative electrode column can form a smooth flow channel, and the design of the second guide surface of the second guide part and the hole wall surface of the second connecting part can not only increase the width of the gap between the negative electrode column and the end cover 20, and prevent the gap between the negative electrode column and the end cover 20 from being too narrow to cause air trapping, but also increase the thickness of the plastic on the negative electrode after molding, avoid the plastic on the negative electrode from being too weak, thereby helping to improve the structural strength of the plastic on the negative electrode.

[0086] See also Figure 4 , Figure 6 and Figure 7The explosion-proof valve 30 is installed on the side of the end cover 20 facing the lower plastic 10, covers the opening of the explosion-proof hole 202 facing the lower plastic 10, and is arranged opposite to the fence part 121. The protection sheet 40 is installed on the side of the end cover 20 away from the lower plastic 10, and covers the opening of the explosion-proof hole 202 away from the lower plastic 10, so as to protect the explosion-proof valve 30 and prevent foreign objects or external forces from damaging the explosion-proof valve 30. Exemplarily, the explosion-proof valve 30 and the protection sheet 40 can be installed on the end cover 20 by welding.

[0087] It can be understood that since the explosion-proof hole 202 connects the inside and outside of the energy storage device 100, when the air pressure inside the energy storage device 100 is too high, the gas inside the energy storage device 100 can pass through the fence part 121 to impact the explosion-proof valve 30, and the explosion-proof valve 30 will rupture under the action of the air pressure. The gas inside the energy storage device 100 can pass through the fence part 121 and the explosion-proof hole 202 in turn and be discharged to the outside of the energy storage device 100 in time, thereby avoiding the explosion of the energy storage device 100 and improving the safety and reliability of the energy storage device 100.

[0088] The sealing member 50 is installed on the injection hole 203 and seals the injection hole 203 to prevent dust, moisture and other impurities from entering the energy storage device 100 through the injection hole 203 of the end cover 20 and the liquid inlet hole 113 of the lower plastic 10 in sequence, thereby ensuring the reliability of the energy storage device 100.

[0089] See also Figure 4 and Fig.10 , Fig.10 yes Figure 5 A schematic diagram of the exploded structure of the positive electrode assembly 70 in the end cap assembly 120 is shown.

[0090] The positive electrode assembly 70 includes a first pole 71, a first sealing ring 72, a first upper plastic 73 and a first adapter 74. The first pole 71 is inserted into the first through hole 112 of the positive lower plastic 11 and the first mounting hole 207 of the end cover 20. The first upper plastic 73 and the first sealing ring 72 are both sleeved on the first pole 71, and isolate the first pole 71 and the end cover 20 to insulate the first pole 71 from the end cover 20. The first upper plastic 73 is located on the side of the first sealing ring 72 away from the lower plastic 10. The first adapter 74 is fixedly connected to the first pole 71, and is electrically connected between the first pole 71 and the positive pole ear of the electrode assembly.

[0091] It should be noted that during the assembly of the end cap assembly 120, the lower plastic 10 is first aligned with the end cap 20, and then the first pole 71 with the first sealing ring 72 is sequentially passed through the first through hole 112 of the positive lower plastic 11 and the first mounting hole 207 of the end cap 20 from the lower plastic 10 to the end cap 20, and pressure is applied to the flange of the first pole 71 to squeeze the first sealing ring 72, so that the first sealing ring 72 is clamped between the first pole 71 and the hole wall of the first mounting hole 207, and then placed in the injection mold, and injection molding is performed in the injection mold. During the injection molding process, the plastic will flow between the hole wall of the first mounting hole 207 and the first pole 71. After the injection molding is completed, the plastic is demoulded after cooling to form the first upper plastic 73.

[0092] See also Figure 4 , Fig.11a , Fig.11b and Fig.12 , Fig.11a yes Fig.10 The schematic diagram of the structure of the first pole 71 in the positive electrode assembly 70 in the first embodiment is shown. Fig.11b yes Fig.11a The schematic diagram of the structure of the first pole 71 at another angle is shown. Fig.12 yes Fig.11a The structure diagram of the first pole 71 after being cut open along DD is shown.

[0093] The first pole 71 includes a first column portion 711 and a first flange portion 712. The first flange portion 712 is fixedly connected to one side of the first column portion 711 in the height direction (ie, the thickness direction D1 of the end cover assembly 120). Exemplarily, the first column portion 711 and the first flange portion 712 may be integrally formed.

[0094] In this embodiment, the first column portion 711 is inserted through the first through hole 112 of the lower plastic 11 of the positive electrode and the first mounting hole 207 of the end cover 20. The first column portion 711 is provided with a first step groove 713 and a first annular groove 714. The opening of the first step groove 713 is located on the surface of the first column portion 711 away from the first flange portion 712. The first step groove 713 is recessed from the surface of the first column portion 711 away from the first flange portion 712 toward the direction of the first flange portion 712, and penetrates the circumference of the first column portion 711. Among them, the first step groove 713 is arranged around the periphery of the first column portion 711.

[0095] During the process of injection molding the first upper plastic 73, the mold retaining ring can abut the groove wall of the first step groove 713 to prevent the plastic from overflowing to the surface of the first column part 711 away from the first flange part 712, thereby preventing the plastic from affecting the subsequent welding stability between the surface of the first column part 711 away from the first flange part 712 and connecting pieces such as aluminum bars.

[0096] Along the height direction of the first column portion 711, the first annular groove 714 is located on the side of the first step groove 713 facing the first flange portion 712, and is spaced apart from the first step groove 713. Specifically, the opening of the first annular groove 714 is provided on the peripheral surface of the first column portion 711. The first annular groove 714 is recessed from the peripheral surface of the first column portion 711 toward the center of the first column portion 711. Among them, the first annular groove 714 is provided around the periphery of the first column portion 711. In the process of injection molding the first upper plastic 73, the design of the first annular groove 714 can increase the contact area between the plastic and the first column portion 711, and improve the connection stability between the first upper plastic 73 and the first pole 71.

[0097] In addition, the first column portion 711 is further provided with at least one first annular structure 715, and along the height direction of the first column portion 711, the first annular structure 715 is located on the side of the first annular groove 714 facing the first flange portion 712. The first annular structure 715 is provided on the circumferential surface of the first column portion 711. The first annular structure 715 extends from the circumferential surface of the first column portion 711 toward the center away from the first column portion 711. The first annular structure 715 is arranged around the periphery of the first column portion 711. Among them, along the height direction of the first column portion 711, the width of the first annular structure 715 is w2, and w2 is between 0.02 mm and 0.45 mm. Exemplarily, w2 is 0.15 mm. Exemplarily, the first annular structure 715 is in the shape of a thread or a line.

[0098] In this embodiment, there are multiple first annular structures 715, and the multiple first annular structures 715 are arranged in sequence at intervals along the height direction of the first cylindrical portion 711. Exemplarily, the multiple first annular structures 715 are arranged in sequence at equal intervals. The design of the multiple first annular structures 715 can increase the abutment area between the first cylindrical portion 711 and the first sealing ring 72, which helps to improve the sealing performance of the first sealing ring 72. In addition, the multiple first annular structures 715 are away from the surface of the first flange portion 712 abutted by the first sealing ring 72, and the multiple first annular structures 715 are subjected to less extrusion force from the first sealing ring 72. The gap between two adjacent first annular structures 715 can accommodate air that is not discharged in time, avoiding the phenomenon of local air entrapment when the multiple first annular structures 715 abut against the first sealing ring 72, which helps to improve the sealing uniformity of each area when the multiple first annular structures 715 abut against the first sealing ring 72. When the first pole 71 is cut and milled, the first annular structure 715 can be formed at one time by controlling the depth of the cutter head, thereby reducing the processing steps of the first pole 71 and helping to reduce the processing cost of the first pole 71. Alternatively, the first annular structure 715 can also be formed by providing convex ribs on the outer surface of the first column portion 711. The embodiment of the present application does not specifically limit the formation method of the first annular structure 715.

[0099] The first flange portion 712 is provided with at least one second annular structure 716 and at least one third annular structure 719. The second annular structure 716 is provided on the surface of the first flange portion 712 facing the first column portion 711. The second annular structure 716 extends from the surface of the first flange portion 712 facing the first column portion 711 in the direction toward the first column portion 711. The second annular structure 716 is located at a position of the first flange portion 712 close to the first column portion 711 and is arranged around the first column portion 711. In the direction from the center to the edge of the first flange portion 712, the width of the second annular structure 716 is w3, and w3 is between 0.01 mm and 0.35 mm. Exemplarily, w3 is 0.05 mm.

[0100] In this embodiment, there are multiple second annular structures 716, and multiple second annular structures 716 are arranged in sequence at equal intervals in the direction from the center to the edge of the first flange portion 712. Exemplarily, the second annular structure 716 covers the surface of the first flange portion 712 facing the first column portion 711. The design of multiple second annular structures 716 can increase the abutment area between the first flange portion 712 and the first sealing ring 72, which helps to improve the sealing performance of the first sealing ring 72. Moreover, the gap between two adjacent second annular structures 716 can accommodate air that has not been discharged in time, which can avoid the phenomenon of local air entrapment when multiple second annular structures 716 abut against the first sealing ring 72, and help to improve the sealing uniformity of each area when multiple second annular structures 716 abut against the first sealing ring 72. When the first pole 71 is cut and milled, the second annular structure 716 can be formed once by controlling the depth of the cutter head, reducing the processing steps of the first pole 71, which helps to reduce the processing cost of the first pole 71.

[0101] In addition, w3 is smaller than w2. It can be understood that in the end cover assembly 120, the contact area between the first flange portion 712 of the first pole 71 and the first sealing ring 72 is larger, the contact area between the first column portion 711 of the first pole 71 and the first sealing ring 72 is smaller, and the width of the second annular structure 716 is smaller than the width of the first annular structure 715, which means that the second annular structure 716 is thinner and the first annular structure 715 is rougher, which can make the overall sealing performance of the first pole 71 more uniform, the electrolyte inside the energy storage device 100 has a longer path to flow out through the gap between the first pole 71 and the first sealing ring 72, and the sealing performance of the first sealing ring 72 is better.

[0102] Moreover, when the first sealing ring 72 is squeezed to perform the injection molding of the first upper plastic 73, firstly, the first sealing ring 72 abuts against the surface of the first flange portion 712 facing the first column portion 711 and the surface of the end cover 20 facing the lower plastic 10, which surrounds the periphery of the first mounting hole 207. Secondly, the compression deformation of the first sealing ring 72 in the thickness direction is tightly abutted against its upper and lower surfaces without sealing, and the first sealing ring 72 extends to both sides in the width direction. Furthermore, the first sealing ring 72 continues to be compressed until its inner side surface abuts against the end of the first annular structure 715 away from the axis of the first column portion 711. There is a gap between the outer circumference of the first column portion 711 and the inner side surface of the first sealing ring 72, and there is air in the gap. Because part of the inner side surface of the first sealing ring 72 is not in contact with the surface of the end cover 20 facing the lower plastic 10, the upper end of the inner side surface of the first sealing ring 72 is slightly tilted. At this time, the wider first annular structure 715 can form a larger exhaust channel, which is conducive to the rapid discharge of air in the gap on the outer circumference of the first column portion 711 to be enclosed and sealed, avoiding local air entrapment between the first sealing ring 72 and the first column portion 711, and improving the uniformity of the seal.

[0103] The third annular structure 719 is disposed on the surface of the first flange portion 712 away from the first column portion 711. The third annular structure 719 extends from the surface of the first flange portion 712 away from the first column portion 711 in a direction away from the first column portion 711. Specifically, the center of the third annular structure 719 coincides with the axis of the first pole 71. There are multiple third annular structures 719, and the multiple second annular structures 716 are concentric. Exemplarily, the third annular structure 719 covers the surface of the first flange portion 712 away from the first column portion 711.

[0104] When cutting and milling the first pole 71, the surface of the first flange 712 away from the first column 711 can be milled to flatten the surface, and the metal burrs remaining on the edge of the surface of the first flange 712 away from the first column 711 during punching can be removed to avoid the risk of the first adapter 74 abutting against the surface of the first flange 712 away from the first column 711 for positioning, causing the metal burrs to fall into the interior of the energy storage device 100 and cause a short circuit. Moreover, when the first adapter 74 and the surface of the first flange 712 away from the first column 711 are laser-penetrated and welded, the molten metal can be guided by the third annular structure 719 and flowed in the axial direction around the first pole 71, consistent with the annular welding trajectory, thereby improving the uniformity of welding, eliminating the internal stress after welding, and avoiding local warping of the welding area.

[0105] See also Figure 4 and Fig.13 , Fig.13 yes Fig.10The structure diagram of the first pole 71 in the positive electrode assembly 70 in the second embodiment is shown.

[0106] The first pole 71 shown in this embodiment is different from the first pole 71 shown in the first embodiment in that each first annular structure 715 is provided with at least one first notch 717 along the circumference of the first column portion 711. Exemplarily, the opening of the first notch 717 is located on the circumference of the first annular structure 715. The first notch 717 is recessed from the circumference of the first annular structure 715 toward the center of the first column portion 711, and connects the opposite sides of the first annular structure 715. Each first annular structure 715 is provided with a plurality of first notches 717, and the first notches 717 of each two adjacent first annular structures 715 are arranged opposite to each other.

[0107] Each second annular structure 716 is provided with at least one second notch 718 arranged along the circumference of the first column portion 711, and the opening of the second notch 718 is located on the surface of the second annular structure 716 facing the first column portion 711. The second notch 718 is recessed from the surface of the second annular structure 716 facing the first column portion 711 toward the first flange portion 712, and passes through the opposite sides of the second annular structure 716. Each second annular structure 716 is provided with a plurality of second notches 718, and the second notches 718 of each two adjacent first annular structures 715 are correspondingly arranged.

[0108] During the process of pressing the first pole 71 and the end cover 20 to form the first upper plastic 73 by injection molding, the first sealing ring 72 is compressed and deformed to cover the first annular structure 715 and the second annular structure 716. The gas between two adjacent first annular structures 715 can be discharged through the first notch 717, and the gas between two adjacent second annular structures 716 can be discharged through the second notch 718, thereby avoiding the phenomenon of trapped air and helping to improve the sealing performance of the first sealing ring 72.

[0109] See also Figure 4 and Fig.14 , Fig.14 yes Fig.10 The structure diagram of the first pole 71 in the positive electrode assembly 70 in the third embodiment is shown.

[0110] The first pole 71 shown in this embodiment is different from the first pole 71 shown in the first embodiment in that the first notches 717 of two adjacent first annular structures 715 are staggered, and the second notches 718 of two adjacent second annular structures 716 are staggered. It should be noted that, after the energy storage device 100 is used for a long time, the internal air pressure of the energy storage device 100 increases, and the electrolyte will penetrate from the gap between the first flange portion 712 and the lower plastic 10. The first notches 717 of the two adjacent first annular structures 715 are staggered, and the second notches 718 of the two adjacent second annular structures 716 are staggered. The leaked electrolyte needs to bypass the second notches 718 of the two adjacent staggered second annular structures 716 and the first notches 717 of the two adjacent staggered first annular structures 715. The leaked electrolyte needs to pass through a more winding path. In other words, the first notches 717 of the two adjacent first annular structures 715 are staggered, and the second notches 718 of the two adjacent second annular structures 716 are staggered, which can extend the path for the electrolyte to penetrate to the outside, and help improve the leakage phenomenon of the energy storage device 100.

[0111] See also Figure 4 , the first sealing ring 72 is sleeved on the first column portion 711 and abuts against the first flange portion 712. Specifically, the first sealing ring 72 is sleeved on the portion of the first column portion 711 facing the first flange portion 712, and is clamped between the first column portion 711 and the hole wall surface of the first mounting hole 207. The surface of the first sealing ring 72 facing the first flange portion 712 abuts against the surface of the first flange portion 712 facing the first column portion 711, and the first sealing ring 72 is clamped between the first flange portion 712 and the first upper plastic 73. Among them, the first sealing ring 72 covers a plurality of first annular structures 715 and at least a portion of the second annular structure 716, so as to increase the contact area between the first sealing ring 72 and the first column portion 711 and the first flange portion 712, which helps to improve the sealing performance of the first sealing ring 72.

[0112] See also Figure 4 , Fig.15 and Fig.16 , Fig.15 yes Fig.10 The structure diagram of the first upper plastic 73 in the positive electrode assembly 70 is shown at another angle. Fig.16 yes Fig.10 The structure diagram of the first upper plastic 73 in the positive electrode assembly 70 after being cut open along EE is shown.

[0113] The first upper plastic 73 is arranged around the first column portion 711, and is connected between the first column portion 711 and the end cover 20, and covers the groove wall surface of the first annular groove 714 and the plurality of first guide portions 241. The first upper plastic 73 is provided with a first convex ring 731, a first convex rib 732 and a first step ring 733. The first convex ring 731 is arranged on the surface of the first upper plastic 73 facing the end cover 20, and extends from the surface of the first upper plastic 73 facing the end cover 20 in a direction away from the end cover 20. The first convex ring 731 is arranged around the first column portion 711. At least part of the first convex ring 731 is located in the first mounting hole 207, and is fixedly connected between the hole wall of the first mounting hole 207 and the first column portion 711, and abuts against the surface of the first sealing ring 72 away from the first flange portion 712.

[0114] The first convex rib 732 is provided on the surface of the first convex ring 731 facing the first sealing ring 72, and extends from the surface of the first convex ring 731 facing the first sealing ring 72 to the direction toward the first sealing ring 72. The first convex rib 732 is provided around the first column portion 711, and is located between the outer peripheral surface of the first column portion 711 and the inner side surface of the first sealing ring 72, and is connected between the first column portion 711 and the first sealing ring 72.

[0115] It is understandable that, since the first pole 71, the first sealing ring 72 and the end cover 20 are all separately processed parts, there will be assembly errors between them, resulting in the first sealing ring 72 being unable to achieve a good seal between the first pole 71 and the end cover 20, and the design of the first convex rib 732 can further improve the sealing performance between the first pole 71 and the first sealing ring 72. In addition, the first convex rib 732 can also isolate the first column portion 711 from the hole wall of the first mounting hole 207, increase the creepage distance between the first column portion 711 and the hole wall of the first mounting hole 207, and help ensure the insulation performance between the first pole 71 and the end cover 20.

[0116] It should be noted that during the cutting and milling process of the first pole 71, metal burrs may appear on the surface of the first pole 71. During the injection molding process of the first upper plastic 73, the first rib 732 can also fold the metal burrs to prevent the metal burrs from extending into the first mounting hole 207 and causing a short circuit between the first pole 71 and the end cover 20, thereby ensuring insulation between the first pole 71 and the end cover 20.

[0117] The first step ring 733 is provided at one end of the first upper plastic 73 away from the end cover 20, and extends from the side surface of the first upper plastic 73 toward the first pole 71 to the direction toward the first pole 71. Specifically, the first step ring 733 partially covers the first step groove 713, is fixedly connected to the groove wall of the first step groove 713, and is arranged around the first column portion 711. There is a gap between the inner side surface of the first step ring 733 and the groove side wall surface of the first step groove 713. Exemplarily, the surface of the first step ring 733 away from the end cover 20 can be flush with the surface of the first upper plastic 73 away from the end cover 20.

[0118] It should be noted that, in the process of injection molding the first upper plastic 73, the injection mold is inserted into the gap between the inner side surface of the first step ring 733 and the side wall of the first step groove 713, and abuts against the side wall and part of the bottom wall of the first step groove 713 to form a closed cavity, so as to prevent the molten plastic liquid from overflowing to the surface of the first pole 71 away from the end cover 20, so as to avoid affecting the subsequent welding effect of the first pole 71 and the connecting pieces such as the bar piece.

[0119] In addition, the first upper plastic 73 is further provided with a first identification groove 734, and the opening of the first identification groove 734 is located on the surface of the first upper plastic 73 away from the end cover 20. The first identification groove 734 is recessed from the surface of the first upper plastic 73 away from the end cover 20 toward the end cover 20. There are two first identification grooves 734, and the two first identification grooves 734 are respectively located on opposite sides of the first upper plastic 73. Exemplarily, the first identification groove 734 is in the shape of a "cross". In some other embodiments, the first identification groove 734 can also be in the shape of a "square" or other shapes.

[0120] The first adapter 74 is installed on the inner side of the positive lower plastic 11 and is located on the side of the first flange 712 away from the first column 711. Specifically, one end of the first adapter 74 is electrically connected to the first flange 712, and the other end is electrically connected to the positive electrode ear of the electrode assembly. Exemplarily, the first adapter 74 can be electrically connected to the first flange 712 and / or the negative electrode ear of the electrode assembly by welding.

[0121] Please also read Figure 4 and Fig.17 , Fig.17 yes Figure 5 A schematic diagram of the exploded structure of the negative electrode assembly 80 in the end cap assembly 120 is shown.

[0122] The negative electrode assembly 80 includes a second pole 81, a second sealing ring 82, a second upper plastic 83 and a second adapter 84. The second pole 81 is inserted into the second through hole 123 of the negative lower plastic 12 and the second mounting hole 208 of the end cover 20. The second upper plastic 83 and the second sealing ring 82 are both sleeved on the second pole 81 and isolate the second pole 81 and the end cover 20 to insulate the second pole 81 from the end cover 20. The second upper plastic 83 is located on the side of the second sealing ring 82 away from the lower plastic 10. The second adapter 84 is fixedly connected to the second pole 81 and electrically connected between the second pole 81 and the negative pole ear of the electrode assembly.

[0123] Among them, the structures of the second pole 81, the second sealing ring 82, the second upper plastic 83 and the second adapter 84, and the matching relationship between the two can all refer to the relevant descriptions of the first pole 71, the first sealing ring 72, the first upper plastic 73 and the first adapter 74 above, and no further description is given here. The difference between the negative electrode assembly 80 and the positive electrode assembly 70 is that in the second upper plastic 83, the second identification groove 834 is in the shape of a "one". In some other embodiments, the second identification groove 834 can also be in the shape of a "negative" or other shapes.

[0124] The present application also provides an electric device, which includes the energy storage device 100, and the energy storage device 100 supplies power to the electric device. The electric device may be a new energy vehicle, a power storage station, a server, or other equipment that requires electricity.

[0125] The above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application; in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An end cap assembly for use in an energy storage device, characterized in that: The invention comprises an end cover and a pole assembly, wherein the end cover is provided with a mounting hole, and the mounting hole penetrates the end cover along the thickness direction of the end cover, the pole assembly comprises a pole, a sealing ring and an upper plastic, the pole comprises a column part and a flange part, the column part is provided with an annular groove, the opening of the annular groove is located on the outer peripheral surface of the column part, the annular groove is arranged around the peripheral edge of the column part, the column part is penetrated by the mounting hole, the column part is provided with a plurality of first annular structures, each of the first annular structures is arranged on the peripheral surface of the column part and is arranged around the column part, along the height direction of the column part, the plurality of the first annular structures are all located on the side of the annular groove facing the flange part, and are arranged in sequence at intervals, and the first annular structure is in the shape of a thread or a line. The flange part is strip-shaped, and is fixedly connected to one side of the column part. The flange part is provided with a plurality of second annular structures, and each of the second annular structures is provided on the surface of the flange part facing the column part, and is arranged around the column part. In the direction from the center to the edge of the surface of the flange part facing the column part, a plurality of the second annular structures are arranged in sequence at equal intervals. The sealing ring is sleeved on the column part, and abuts against the surface of the flange part facing the column part, and is clamped between the end cover and the pole. The sealing ring also covers the first annular structure and at least part of the second annular structure. The upper plastic sleeve is provided on the column part, and covers the groove wall of the annular groove, and is connected between the column part and the end cover.

2. The end cap assembly according to claim 1, characterized in that: Along the height direction of the column portion, a plurality of the first annular structures are arranged in sequence at equal intervals.

3. The end cap assembly according to claim 1, characterized in that: Each of the first annular structures is provided with at least one first notch along the circumference of the column portion.

4. The end cap assembly according to claim 3, characterized in that: The first notches of every two adjacent first annular structures are arranged opposite to each other, or the first notches of every two adjacent first annular structures are arranged in a staggered manner.

5. The end cap assembly according to claim 1, characterized in that: The width of the first annular structure is between 0.02 mm and 0.45 mm.

6. The end cap assembly according to claim 1, characterized in that: A plurality of the second annular structures are distributed on the surface of the flange portion facing the column portion.

7. The end cap assembly according to claim 6, characterized in that: Each of the second annular structures is provided with at least one second notch arranged along the circumference of the column portion.

8. The end cap assembly according to claim 7, characterized in that: The second notches of every two adjacent second annular structures are arranged opposite to each other, or the second notches of every two adjacent second annular structures are arranged in a staggered manner.

9. The end cap assembly according to any one of claims 1 and 6 to 8, characterized in that The width of the second annular structure is smaller than the width of the first annular structure.

10. The end cap assembly according to any one of claims 1 and 6 to 8, characterized in that The width of the second annular structure is between 0.01 mm and 0.35 mm.

11. The end cap assembly according to claim 1, characterized in that: The upper plastic is provided with a convex ring and a convex rib. The convex ring is provided on the surface of the upper plastic facing the end cover and is arranged around the column portion. At least part of the convex ring is located in the mounting hole and is provided between the hole wall of the mounting hole and the column portion, and abuts against a part of the surface of the sealing ring away from the flange portion. The convex rib is provided on the surface of the convex ring facing the sealing ring and is arranged around the column portion. The convex rib is located between the inner side surface of the sealing ring and the outer peripheral surface of the column portion.

12. The end cap assembly according to claim 1, wherein: The flange portion is further provided with at least one third annular structure, and the third annular structure is provided on a surface of the flange portion away from the column portion.

13. The end cap assembly according to claim 12, characterized in that: There are a plurality of the third annular structures, and the plurality of the third annular structures are cocentric and cover the surface of the flange portion away from the column portion.

14. The end cap assembly according to claim 1, wherein: The column part is provided with a step groove, the opening of the step groove is located on the surface of the column part away from the end cover, the step groove is arranged around the edge of the column part and passes through the outer peripheral surface of the column part; The upper plastic is also provided with a step ring, which is fixedly connected to the side of the upper plastic facing the pole and is located on the side of the upper plastic away from the end cover. The step ring partially covers the step groove, and there is a gap between the inner side surface of the step ring and the side wall surface of the step groove.

15. The end cap assembly according to claim 1, wherein: The mounting hole includes a mounting hole portion and a countersunk hole portion, the countersunk hole portion is located on one side of the mounting hole portion and is connected to the mounting hole portion, the cross-sectional area of ​​the countersunk hole portion is larger than the cross-sectional area of ​​the mounting hole portion, the hole wall of the countersunk hole portion includes a plurality of guide portions, the plurality of guide portions are spaced around the mounting hole portion, and the upper plastic covers the plurality of guide portions.

16. The end cap assembly according to claim 15, characterized in that Each of the guide portions is spaced apart from the mounting hole portion, and the thickness of the guide portion gradually decreases in a direction from the countersunk hole portion to the mounting hole portion.

17. The end cap assembly according to claim 16, characterized in that The mounting hole portion includes a mounting part and a connecting part, wherein the connecting part connects the mounting part and the countersunk hole portion, and a cross section of the connecting part gradually decreases in a direction from the countersunk hole portion to the mounting hole portion.

18. An energy storage device, characterized in that: The invention comprises a shell and an end cover assembly according to any one of claims 1 to 17, wherein the end cover assembly is installed on one side of the shell.

19. An electrical equipment, characterized in that: It includes the energy storage device as described in claim 18, and the energy storage device supplies power to the electrical equipment.

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