End cover assembly, energy storage device, and electric apparatus

Abstract

The present application discloses an end cover assembly, an energy storage device, and an electric apparatus. The end cover assembly comprises an end cover, an upper plastic, and a pole; the end cover comprises a first surface and a second surface which are provided facing away from each other; the pole comprises a pole body and a flange connected to one end of the pole body; the end cover further comprises a mounting hole; the mounting hole passes through the first surface and the second surface; a protruding portion protrudes out of the first surface; the protruding portion surrounds the mounting hole; the protruding portion is provided with an end surface; the upper plastic comprises an upper plastic body and a protruding ridge; the plastic body comprises a stepped surface and an abutting surface; the stepped surface and the abutting surface are provided facing away from each other in the height direction of the upper plastic; the protruding ridge protrudes out of the edge of the stepped surface away from the center of the upper plastic, and the upper plastic body and the protruding ridge define a pole through hole; the pole passes through the pole through hole; the surface of the flange facing the pole body abuts against the stepped surface; the protruding ridge surrounds the periphery of the flange; the upper plastic and the pole are accommodated in the mounting hole; the protruding ridge protrudes out of the first surface; and the abutting surface abuts against the end surface in the thickness direction of the end cover assembly.

Description

End cover assembly, energy storage device and electrical equipment

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on March 27, 2024, with application number 2024103614738 and application name “End cover assembly, energy storage device and electrical equipment”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] 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

[0003] As demand for secondary energy storage devices grows, so too do demands for energy density, reliability, sealing performance, and cost, particularly for the top cover. Existing end cap assemblies suffer from poor sealing, which can cause electrolyte to flow through the plastic and end cap during filling. This can corrode internal components and even render the end cap assembly useless, reducing the safety and reliability of the device. Summary of the Invention

[0004] The present application provides an end cap assembly, an energy storage device, and electrical equipment, which improve the sealing of the end cap assembly, block the leakage path of the electrolyte, reduce the corrosion of the electrolyte on the internal structural parts of the end cap assembly, and increase the safety and reliability of the energy storage device.

[0005] The present application provides an end cap assembly, comprising an end cap, an upper plastic, and a pole; the end cap comprises a first surface and a second surface, the first surface and the second surface being arranged in opposite directions along the thickness direction of the end cap assembly; the pole comprises a pole body and a flange connected to one end of the pole body;

[0006] The end cover further includes a mounting hole, the mounting hole passing through the first surface and the second surface, a raised portion is convexly provided on the first surface, the raised portion surrounds the mounting hole, and the raised portion is provided with an end surface;

[0007] The upper plastic includes an upper plastic body and a flange. The upper plastic body includes a step surface and an abutting surface. Along the height direction of the upper plastic, the step surface and the abutting surface are arranged in opposite directions. The flange is protruding from the edge of the step surface away from the center of the upper plastic, and the upper plastic body and the flange enclose a pole through hole.

[0008] The pole is passed through the pole through-hole, the surface of the flange facing the pole body abuts against the step surface, the flange surrounds the outer circumference of the flange, the upper plastic and the pole are accommodated in the mounting hole, the flange protrudes from the first surface, and along the thickness direction of the end cover assembly, the abutting surface abuts against the end surface.

[0009] The present application provides an end cap assembly, comprising an end cap, an upper plastic, and a pole; the end cap comprises a first surface and a second surface, the first surface and the second surface being arranged in opposite directions along the thickness direction of the end cap assembly; the pole comprises a pole body and a flange connected to one end of the pole body;

[0010] The end cover further includes a mounting hole, the mounting hole passing through the first surface and the second surface, a raised portion is convexly provided on the first surface, and the raised portion surrounds the mounting hole;

[0011] The raised portion includes a first boss and a second boss, the first boss is connected to the first surface, the first boss is provided with an end surface facing away from the first surface, and the second boss is provided on an edge of the end surface away from the axis of the mounting hole;

[0012] The upper plastic includes an upper plastic body and a flange, and the upper plastic body and the flange enclose a pole through hole; the upper plastic body includes a step surface and an abutment surface, and along the axial direction of the pole through hole, the step surface and the abutment surface are arranged in opposite directions, and the flange includes a sub-flange and an extended edge, and the sub-flange is protruded from the edge of the step surface away from the center of the upper plastic.

[0013] The extension edge is formed by bending and extending one end of the sub-flange, and then bending and extending in an axial direction parallel to the pole through hole. Along the radial direction of the pole through hole, the extension edge is spaced apart from the sub-flange and the upper plastic body.

[0014] The pole is passed through the pole through-hole, the surface of the flange facing the pole body abuts against the step surface, the sub-flange surrounds the outer circumference of the flange, the upper plastic and the pole are accommodated in the mounting hole, the second boss extends between the extension edge and the sub-flange, the first boss extends between the extension edge and the upper plastic body, and along the thickness direction of the end cover assembly, the abutting surface abuts against the end surface.

[0015] The present application provides an energy storage device, comprising the end cap assembly, a shell and a battery cell, wherein the battery cell is installed in the shell, and the end cap assembly is installed at one end of the shell and encapsulates the battery cell.

[0016] The present application provides an electrical device, comprising the energy storage device described above, wherein the energy storage device is used to supply power to the electrical device.

[0017] In the present application, in the thickness direction of the end cover assembly, the upper plastic body of the upper plastic is abutted against the raised portion, and the flange surrounding the flange is farther away from the first surface than the upper plastic body, so that the gap between the flange and the upper plastic is farther away from the first surface, that is, the gap between the upper plastic and the first pole is raised compared to the end cover, and the electrolyte splashed out when the electrolyte is injected will not easily enter the gap between the upper plastic and the pole, preventing the electrolyte from flowing into the pole and the lower plastic and the pressure ring, thereby improving the insulation performance of the battery cell, and at the same time reducing the possibility of corrosion of the upper plastic by the sputtered electrolyte, thereby improving the strength of the upper plastic. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained like these drawings without any creative work.

[0019] FIG1 is a diagram of an application scenario of an energy storage device provided in an embodiment of the present application;

[0020] FIG2 is a schematic structural diagram of a first embodiment of the energy storage device shown in FIG1 ;

[0021] FIG3 is a schematic structural diagram of an end cap assembly of the energy storage device shown in FIG2 ;

[0022] FIG4 is a schematic diagram of the exploded structure of the end cap assembly shown in FIG3 ;

[0023] FIG5 is a schematic cross-sectional view of the pole of the end cap assembly shown in FIG3 ;

[0024] FIG6 is an exploded cross-sectional schematic diagram of a portion of the end cap assembly shown in FIG3 ;

[0025] FIG7 is a schematic cross-sectional view of the upper plastic portion of the end cap assembly shown in FIG3 ;

[0026] FIG8 is a schematic cross-sectional view of the end cap assembly shown in FIG3 ;

[0027] FIG9 is a schematic structural diagram of an end cap assembly of a second embodiment of the energy storage device shown in FIG1 ;

[0028] FIG10 is a schematic diagram of the upper plastic structure of the end cap assembly shown in FIG9 ;

[0029] FIG11 is a schematic cross-sectional view of the upper plastic portion of the end cap assembly shown in FIG9 ;

[0030] FIG12 is a schematic cross-sectional view of the end cap assembly shown in FIG9;

[0031] FIG13 is a schematic structural diagram of an end cap assembly of a third embodiment of the energy storage device shown in FIG1 ;

[0032] FIG14 is an exploded schematic diagram of a portion of the structure of the end cap assembly shown in FIG13;

[0033] FIG15 is a schematic cross-sectional view of the end cap of the end cap assembly shown in FIG13;

[0034] FIG16 is a schematic cross-sectional view of the upper plastic portion of the end cap assembly shown in FIG13 ;

[0035] FIG17 is a schematic cross-sectional view of the end cap assembly shown in FIG13.

[0036] The nouns corresponding to the reference numerals in the figure are: energy storage system 5000, electric energy conversion device 4500, wind energy conversion device 4000, second electrical equipment 3000, energy storage device 1000, end cover assembly 100, housing 400, end cover 10, first pole 21, second pole 22, first upper plastic 30, second upper plastic 40, lower plastic 50, first pressing block 61, second pressing block 62, first pole body 211, first flange 212, first metal part 215, second metal part 2 16, connection interface 217, second pole body 221, second flange 222, first through hole 613, second through hole 623, first surface 11, second surface 12, first mounting groove 13, second mounting groove 14, first mounting hole 15, second mounting hole 16, first protrusion 17, second protrusion 18, first end surface 170, second end surface 180, second groove bottom wall 142, first groove bottom wall 132, lower plastic body 51, third surface 511, fourth surface 512, first avoidance Groove 52, second avoidance groove 53, first protrusion 54, second protrusion 55, first assembly hole 58, second assembly hole 59, first upper plastic body 31, first flange 32, first inner ring surface 311, first step surface 312, first abutting surface 313, first pole through hole 33, second upper plastic body 41, second flange 42, second inner ring surface 411, second step surface 412, second abutting surface 413, second pole through hole 43, first sub-flange 321, first extension edge 32 2, first inner side surface 3210, first inclined surface 3211, first plane 3213, second sub-flange 421, second extended edge 422, second inner side surface 4210, second inclined surface 4211, second plane 4213, gap A, first boss 171, second boss 172, third boss 181, fourth boss 182, third sub-holding gap 35, first sub-holding gap 34, second sub-holding gap 44, fourth sub-holding gap 45, first sealing ring 63, second sealing ring 64. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0038] In this application, unless otherwise expressly specified and limited, terms such as "installed", "connected", "connected", and "fixed" should be understood in a broad sense. For example, the connection may be fixed, detachable, or integrated; the connection may be mechanical, electrical, or communicative; the connection may be direct or indirect through an intermediate medium; the connection may be internal to two elements or an interaction relationship between two elements, unless otherwise clearly specified and limited.

[0039] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0040] Taking electrochemical energy storage as an example, this solution provides an energy storage device with a group of chemical batteries inside. The energy storage device 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 medium. Simply put, the electricity generated by wind and solar energy is stored in the 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.

[0041] Currently, 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 energy storage device types include:

[0042] (1) Large energy storage containers used in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the grid, achieving load matching of electricity in time and space, enhancing the ability to absorb renewable energy, and are of great significance in grid system backup, alleviating peak load power supply pressure, and peak and frequency regulation;

[0043] (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, they release the electricity in the energy storage equipment for use, thereby saving electricity costs.

[0044] 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 energy storage devices can be understood as electrical equipment.

[0045] Please refer to FIG1 , which is a diagram of an application scenario of the energy storage device provided in an embodiment of the present application.

[0046] The energy storage device 1000 provided in the embodiment of the present application is applied to an energy storage system 5000, which includes an electric energy conversion device 4500 (photovoltaic panel), a wind energy conversion device 4000 (windmill), a first electric device (grid), a second electric device 3000 (base station) and an energy storage device 1000. The energy storage system 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 electric energy conversion device can convert solar energy into electric energy during periods of low electricity prices, and the energy storage device 1000 is used to store the electric energy and supply it to the first electric device or the second electric device during peak electricity consumption, or to supply power when the first electric device or the second electric device is powered off / out of power. The second electric energy conversion device 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 electric device or the second electric device during peak electricity consumption, or to supply power when the first electric device or the second electric device is powered off / out of power. Among them, the transmission of electric energy can be carried out using high-voltage cables.

[0047] It should be noted that the first electric device, the second electric device and other devices including the energy storage device 1000 can be understood as electric devices.

[0048] Please refer to FIG. 2 , which is a schematic structural diagram of the first embodiment of the energy storage device shown in FIG. 1 .

[0049] The energy storage device 1000 may include but is not limited to single cells, battery modules, battery packs, battery systems, etc. It is understandable that 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-acid) 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. It should be noted that the number of energy storage devices 1000 may be several, and several energy storage devices 1000 are connected in series or in parallel. In this embodiment, "several" refers to two or more.

[0050] The energy storage device 1000 includes an end cover assembly 100, a shell 400 and a battery cell (not shown). The shell 400 includes an opening (not shown) and a receiving cavity (not shown). The battery cell includes a positive electrode ear (not shown) and a negative electrode ear (not shown). The end cover assembly 100 includes a first electrode 21 and a second electrode 22. When assembling the energy storage device 1000, the positive electrode ear is first welded to the first electrode 21 and the negative electrode ear is welded to the second electrode 22. Then, the battery cell is placed in the receiving cavity of the shell 400, and the end cover assembly 100 is sealed to the opening of the shell 400 to assemble into a semi-finished battery. After a series of processes such as liquid injection, the energy storage device 1000 is obtained. This application does not limit the specific structure of the energy storage device 1000.

[0051] For ease of description, in this application, the thickness direction of the energy storage device 1000 is defined as the Z-axis direction, the width direction is defined as the X-axis direction, and the length direction is defined as the Y-axis direction. The X-axis, Y-axis, and Z-axis directions are perpendicular to each other. The directional terms such as "upper", "top", "lower", "bottom", "left", and "right" mentioned in the description of the embodiments of this application are descriptions based on the orientation shown in Figure 2 of the specification, and do not constitute a limitation on the actual application scenario of the energy storage device 1000. A certain tolerance is allowed for the "same", "equal" or "parallel" used in the following text.

[0052] It should be noted that the end cap assembly 100 includes two poles (not shown) and the corresponding upper plastics of the two poles, the pole through holes provided on the end cap, the protrusions, the sealing ring and other related structures. The two poles are used to connect to the positive electrode tab and the negative electrode tab respectively. In the following specific embodiments, for the convenience of description, two components of the same structure are named first and second respectively to distinguish them. The different materials of the two poles lead to different structures. For the sake of ease of understanding, they are also named first and second to distinguish them.

[0053] 3 and 4 , the end cap assembly 100 includes an end cap 10 , a first pole 21 and a second pole 22 , a first upper plastic 30 and a second upper plastic 40 , a lower plastic 50 , a first pressing block 61 and a second pressing block 62 .

[0054] The first electrode 21 may be a positive electrode and the second electrode 22 may be a negative electrode, or the first electrode 21 may be a negative electrode and the second electrode 22 may be a positive electrode.

[0055] The first and second poles 21 and 22 are located at opposite ends of the end cap assembly 100 along its length. The end cap 10 and the lower plastic 50 are stacked along the thickness of the end cap assembly 100. The first upper plastic 30 fits over the first pole 21, insulating the end cap 10 from the first pole 21. The second upper plastic 40 fits over the second pole 22, insulating the second pole 22 from the end cap 10. The first pole 21, the first upper plastic 30, and the first pressing block 61 are sequentially arranged and connected to the end cap 10 and the lower plastic 50. The first pole 21 is insulated and sealed from the end cap 10 by the cooperation of the first sealing ring 63, the first upper plastic 30, and the lower plastic 50. The second pole 22, the second upper plastic 40, and the second pressing block 62 are sequentially arranged and connected to the end cap 10 and the lower plastic 50. The second pole 22 is insulated and sealed from the end cap 10 by the cooperation of the second upper plastic 40, the second sealing ring 64, and the lower plastic 50.

[0056] Referring to Figure 5 , the first pole 21 includes a first pole body 211 and a first flange 212. Along the height of the first pole 21, the first pole body 211 is connected to a surface of one side of the first flange 212. In this embodiment, the first flange 212 is a circular block, and the first pole body 211 protrudes from a surface of the first flange 212. The first flange 212 and the first pole body 211 are coaxially arranged.

[0057] In this embodiment, the first terminal 21 is a negative electrode. The first terminal 21 also includes a first metal portion 215 and a second metal portion 216. Along the height of the first terminal 21, the first metal portion 215 covers the side of the second metal portion 216 facing away from the first flange 212 of the first terminal 21. It is understood that the outer surface of the first terminal body 211 and the outer surface of the first flange 212 facing the first terminal body 211 together constitute the first metal portion 215. A connection interface 217 is formed between the first metal portion 215 and the second metal portion 216. In this embodiment, the connection interface 217 is a curved surface, generally a "bowl"-shaped interface. It is understood that the opposing surfaces of the first metal portion 215 and the second metal portion 216 are curved. The first terminal 21 can be formed by integral stamping or machining. In this embodiment, the first terminal 21 can be a copper-aluminum composite structure formed by stamping, which simplifies the processing and improves production efficiency, effectively reducing the production cost of the first terminal 21. For example, the first metal portion 215 of the first pole 21 is made of copper, and the second metal portion 216 is made of aluminum. The first flange 212 and the second metal portion 216 are integrally formed.

[0058] In this embodiment, the structure of the second pole 22 is similar to that of the first pole 21 (see Figure 7 ). The difference is that the material of the second pole 22 is different from that of the first pole 21. In this embodiment, the second pole 22 is the positive pole. The second pole 22 includes a second pole body 221 and a second flange 222. In this embodiment, the second flange 222 is a circular block, and the second pole body 221 is protruding from a surface of the second flange 222. The second flange 222 and the second pole body 221 are coaxially arranged.

[0059] As shown in Figure 4 , the first pressing block 61 includes a first through-hole 613, which extends through two opposing surfaces of the first pressing block 61 along its thickness direction. The first through-hole 613 is used to allow the first terminal 21 to pass through. The second pressing block 62 has the same structure as the first pressing block 61 and includes a second through-hole 623, which extends through two opposing surfaces of the second pressing block 62 along its thickness direction. The second through-hole 623 is used to allow the second terminal 22 to pass through. In other embodiments, the structure of the second pressing block 62 may differ from that of the first pressing block 61.

[0060] In this embodiment, the end cap assembly 100 further includes a first sealing ring 63 and a second sealing ring 64. Please refer to FIG. 8 .

[0061] Referring to FIG6 , the end cap 10 is a generally rectangular plate. In this embodiment, the end cap 10 is a plain aluminum sheet. The end cap 10 includes a first surface 11 and a second surface 12 , which are disposed opposite to each other along the thickness direction of the end cap 10 .

[0062] End cap 10 includes a first mounting slot 13 and a second mounting slot 14, located at opposite ends of the end cap 10 in its longitudinal direction. First mounting slot 13 is a generally rectangular slot, with its opening located on second surface 12. First mounting slot 13 is recessed from second surface 12 toward first surface 11. First mounting slot 13 includes a first bottom wall 132.

[0063] In this embodiment, the structure of the second mounting groove 14 is identical to that of the first mounting groove 13. The opening of the second mounting groove 14 is located on the second surface 12, and the second mounting groove 14 is recessed from the second surface 12 toward the first surface 11. The second mounting groove 14 includes a second groove bottom wall 142.

[0064] The end cap 10 also includes a first mounting hole 15 and a second mounting hole 16. The first mounting hole 15 and the second mounting hole 16 are located at opposite ends of the end cap 10 along its length. Along the thickness of the end cap 10, the first mounting hole 15 extends through the first surface 11 and the first groove bottom wall 132. The second mounting hole 16 extends through the first surface 11 and the second groove bottom wall 142. In other embodiments, the structures of the first mounting groove 13 and the second mounting groove 14 may differ.

[0065] The end cover 10 also includes a first protrusion 17 and a second protrusion 18. The first protrusion 17 is a closed annular structure, which is protruded from the first surface 11 and surrounds the first mounting hole 15. The first protrusion 17 of this embodiment is connected to the hole wall of the first mounting hole 15 and is coaxially arranged with the first mounting hole 15. Exemplarily, the first protrusion 17 and the second protrusion 18 are circular ring structures. In the radial direction of the first mounting hole 15, the first protrusion 17 has a certain width, and its outer diameter is larger than the diameter of the first mounting hole 15, and the inner diameter of the first protrusion 17 is the same as the diameter of the first mounting hole 15. The first protrusion 17 includes a first end face 170, which is the surface of the free end of the first protrusion 17 away from the first surface 11.

[0066] In this embodiment, the second protrusion 18 has the same structure as the first protrusion 17. The second protrusion 18 is protruded from the first surface 11 and surrounds the second mounting hole 16, and is coaxially arranged with the second mounting hole 16. In the radial direction of the second mounting hole 16, the second protrusion 18 has a certain width, its outer diameter is larger than the diameter of the second mounting hole 16, and the inner diameter of the second protrusion 18 is the same as the diameter of the second mounting hole 16. The second protrusion 18 includes a second end surface 180, which is the surface of the free end of the second protrusion 18 away from the first surface 11. The above-mentioned "same" can allow a certain tolerance range. In this embodiment, the angle between the first protrusion 17 and the second protrusion 18 and the first surface 11 is 90 degrees.

[0067] The lower plastic 50 includes a lower plastic body 51. The lower plastic body 51 is generally a thin rectangular plate. The length of the lower plastic body 51 is the same as the length of the end cap 10, and the width of the lower plastic body 51 is comparable to the length of the end cap 10, with a certain tolerance range allowed. The lower plastic body 51 includes a third surface 511 and a fourth surface 512, which are arranged opposite to each other along the thickness direction of the lower plastic 50. In this embodiment, the lower plastic 50 can be a one-piece structure made of plastic material; in other embodiments, the lower plastic 50 can also be composed of two sub-lower plastics.

[0068] The lower plastic 50 includes a first avoidance groove 52 and a second avoidance groove 53. The first avoidance groove 52 and the second avoidance groove 53 are respectively located on opposite sides of the length direction of the lower plastic 50. The openings of the first avoidance groove 52 are both located on the fourth surface 512. The first avoidance groove 52 is recessed from the fourth surface 512 toward the third surface 511. The first avoidance groove 52 includes a first bottom wall (not marked in the figure). In this embodiment, the structure of the second avoidance groove 53 is the same as that of the first avoidance groove 52. The opening of the second avoidance groove 53 is located on the fourth surface 512. The second avoidance groove 53 is recessed from the fourth surface 512 toward the third surface 511. The second avoidance groove 53 includes a second bottom wall (not marked in the figure).

[0069] The lower plastic body 50 also includes a first protrusion 54 and a second protrusion 55. The first protrusion 54 and the second protrusion 55 are protruded from the third surface 511 and are located at opposite ends of the length of the lower plastic body 51. The first avoidance groove 52 is recessed from the fourth surface 512 toward the third surface 511 and protrudes from the third surface 511 to form the first protrusion 54. The shape of the first protrusion 54 matches the shape of the first avoidance groove 52. In this embodiment, the structure of the second protrusion 55 is the same as that of the first protrusion 54. The second avoidance groove 53 is recessed from the fourth surface 512 toward the third surface 511 and protrudes from the third surface 511 to form the second protrusion 55.

[0070] The lower plastic 50 also includes a first assembly hole 58 and a second assembly hole 59. The first assembly hole 58 passes through the surface of the first protrusion 54 and the first bottom wall of the first avoidance groove 52. It can be understood that the first assembly hole 58 passes through the third surface 511 and the first bottom wall, and the first assembly hole 58 is connected to the first avoidance groove 52 for the first pole 21 to pass through. The first assembly hole 58 is a circular hole. In this embodiment, the structure of the second assembly hole 59 is the same as that of the first assembly hole 58. The second assembly hole 59 passes through the surface of the second protrusion 55 and the second bottom wall of the second avoidance groove 53, and the second assembly hole 59 is connected to the second avoidance groove 53 for the second pole 22 to pass through. In other embodiments, the structure of the first assembly hole 58 and the structure of the second assembly hole 59 may be different.

[0071] Referring to Figure 7 , the first upper plastic part 30 and the second upper plastic part 40 are annular plastic parts. The annular shape is designed to match the cylindrical first pole 21. When the first pole is a rectangular column, the shapes of the first upper plastic part 30 and the second upper plastic part 40 can also be changed accordingly. The first upper plastic part 30 includes a first upper plastic body 31 and a first flange 32. Along the height direction of the first upper plastic part, the first upper plastic body 31 and the first flange 32 are connected. In this embodiment, the first upper plastic body 31 has a generally L-shaped cross-section and includes a first inner ring surface 311, a first step surface 312, and a first abutting surface 313. The first inner ring surface 311 and the first step surface 312 are connected, and there is an angle between the first inner ring surface 311 and the first step surface 312. In this embodiment, the angle between the first inner ring surface 311 and the first step surface 312 is 90 degrees. The first inner ring surface 311 is the surface of the first upper plastic body 31 facing the central axis, and the first stepped surface 312 extends radially along the first pole through hole 33. The first stepped surface 312 and the first abutting surface 313 are arranged in opposite directions, and the first abutting surface 313 is connected to the outer circumference of the first upper plastic body 31.

[0072] The first flange 32 protrudes from the edge of the surface of the first step surface 312 facing away from the first upper plastic body 31 and away from the first upper plastic body 31. The inner diameter of the first flange 32 is larger than the inner diameter of the first upper plastic body 31. In other embodiments, if the pole is a rectangular column, the first pole through hole of the first upper plastic 30 can be rectangular. An angle is formed between the first flange 32 and the first step surface 312, and in this embodiment, the angle is 90 degrees. In other embodiments, the connection between the first inner ring surface 311 and the first step surface 312, as well as the connection between the first flange 32 and the first step surface 312, can be provided with an arc chamfer, but the overall angle can be understood to be 90 degrees.

[0073] The first upper plastic component 30 also includes a first pole through-hole 33. The first pole through-hole 33 is used to allow the first pole 21 to pass through. The first upper plastic body 31 and the first flange 32 together form the first pole through-hole 33. It will be appreciated that the first inner ring surface 311 and the surface of the first flange 32 facing the center of the hole together form the wall of the first pole through-hole 33. In this embodiment, the first upper plastic component 30 is a separate injection-molded component, enabling the simultaneous production of multiple first upper plastic components 30 using a single mold with multiple cavities, thereby reducing costs.

[0074] In this embodiment, the structure of the second upper plastic member 40 is identical to that of the first upper plastic member 30. The second upper plastic member 40 comprises a second upper plastic body 41 and a second flange 42. The connection between the second upper plastic body 41 and the second flange 42 can be described in detail in conjunction with the first upper plastic member 30 and will not be further elaborated here. The second upper plastic body 41 comprises a second inner ring surface 411, a second stepped surface 412, and a second abutting surface 413. The second stepped surface 412 and the second abutting surface 413 face away from each other, and the second abutting surface 413 is connected to the outer circumference of the second upper plastic body 41.

[0075] The second upper plastic 40 further includes a second pole through hole 43 . The second pole through hole 43 is used for the second pole 22 to pass through. The second upper plastic body 41 and the second flange 42 together form the second pole through hole 43 .

[0076] Referring also to Figure 8 , in this embodiment, the end cap 10 and the lower plastic body 50 are stacked along the Z-axis. The second surface 12 of the end cap 10 faces the third surface 511 of the lower plastic body 50, while the fourth surface 512 of the lower plastic body 51 faces the housing 400 and faces away from the end cap 10. The first protrusion 54 of the lower plastic body 50 engages with the first mounting groove 13 of the end cap 10. Specifically, the first protrusion 54 is received in the first mounting groove 13. The first mounting hole 15 communicates with and is coaxially arranged with the first assembly hole 58 of the lower plastic body 50. The surface of the first protrusion 54 abuts the first bottom wall 132 of the first mounting groove 13. The second protrusion 55 of the lower plastic body 50 engages with the second mounting groove 14 of the end cap 10. Specifically, the second protrusion 55 is received in the second mounting groove 14. The second mounting hole 16 and the second assembly hole 59 are coaxially arranged. The surface of the second protrusion 55 abuts the second bottom wall 142 of the second mounting groove 14.

[0077] The first upper plastic member 30 is sleeved around the outer periphery of the first pole 21. The first pole body 211, sleeved with the first upper plastic member 30, passes through the first mounting hole 15 of the end cap 10 and the first assembly hole 58 of the lower plastic member 50, and extends into the first avoidance groove 52. The first upper plastic member 31 is positioned between the first pole body 211 and the end cap 10, and serves to insulate the first pole 21 from the end cap 10. The first upper plastic body 31 surrounds the first terminal body 211 and the outer circumference of the first flange 212 at the periphery of the first terminal body 211, with the first inner annular surface 311 facing the outer circumference of the first terminal body 211. The first flange 32 surrounds the outer circumference of the first flange 212, and the height of the first flange 32 at least covers the connection (connection interface) between the first metal part 215 and the second metal part 216. That is, along the thickness direction of the end cap assembly, the height of the first flange 32 exceeds the connection (interface) between the first metal part 215 and the second metal part 216. It can be understood that the first flange 32 is higher than the highest point of the end cap than the said interface. The first flange 32 can protect the first terminal 21, preventing corrosion at the interface of the first terminal 21 caused by the external environment, which affects the energy efficiency of the battery cell, and at the same time, improve product consistency. The first abutting surface 313 of the first upper plastic body 31 facing away from the first flange 32 abuts against the first end face 170 of the first protrusion 17 facing away from the end cap 10.

[0078] A gap is formed between the first upper plastic body 31 and the first bottom wall of the first escape groove 52 of the lower plastic body 50 to accommodate the first sealing ring 63. The first pressure block 61 and the first sealing ring 63 are installed in the first escape groove 52 and are placed over the end of the first pole body 211 located in the first escape groove 52. The first pressure block 61 abuts against the lower plastic body 50, and the first sealing ring 63 is clamped between the end cap 10 and the first pressure block 61. The first upper plastic body 30 and the first sealing ring 63 seal the first pressure block 61, the lower plastic body 50, and the end cap 10.

[0079] In this embodiment, the first protrusion 17 protrudes from the first surface 11 of the end cap 10 and surrounds the periphery of the first mounting hole 15. After the electrolyte is injected toward the first surface 11 of the end cap, if the electrolyte splashes and falls on the first surface 11 of the end cap 10, it will be blocked by the first protrusion 17. This first prevents the electrolyte from entering the interior of the end cap assembly 100 through the gap between the first upper plastic 30 and the end cap 10, thereby preventing corrosion of the first terminal 21 and the first upper plastic 30. It also prevents the electrolyte from accumulating in the gap between the first upper plastic 30 and the end cap 10, preventing this electrolyte from flowing out when the top patch is attached, corroding the top patch, and causing a decrease in the insulation performance of the entire battery cell, resulting in a short circuit.

[0080] In the thickness direction of the end cap assembly 100, the first upper plastic body 31 of the first upper plastic member 30 abuts against the first protrusion 17, and the first flange 32 surrounding the first flange 212 is farther from the first surface 11 than the first upper plastic body 31. As a result, the gap between the first flange 212 and the first upper plastic member 30 is farther from the first surface 11. That is, the gap between the first upper plastic member 30 and the first electrode 21 is raised compared to the end cap 10. When the electrolyte is injected, the splashed electrolyte will not easily enter the gap between the first upper plastic member 30 and the first electrode 21, thereby preventing the electrolyte from flowing into the gap between the first electrode, the first lower plastic member 50, and the first pressing block 61. This improves the insulation performance of the battery cell, reduces the possibility of corrosion of the first upper plastic member 30 by the splashed electrolyte, and improves the strength of the first upper plastic member 30.

[0081] Similarly, the assembly relationship between the second pole 22, the second upper plastic 40, the second pressure block 62, the second sealing ring 64, the end cover 10 and the lower plastic 50 can refer to the description of the assembly of the first pole 21 and its related structures. The effects produced can also refer to the above description and are not repeated here.

[0082] 9 , the energy storage device (not shown) of the second embodiment of the present application includes an end cap assembly, a housing, and a battery cell. The specific assembly relationship can be found in the energy storage device 1000 of the first embodiment described in FIG. 2 .

[0083] In this embodiment, the energy storage device differs from the energy storage device described in the first embodiment in the structure of the upper plastic in the end cap assembly 100. It should be noted that in this embodiment, the description and drawings of the parts having the same structure as the end cap assembly 100 described in FIG3 are directly quoted and will not be described in detail again.

[0084] The end cap assembly 100 includes an end cap 10, a first pole 21, a second pole 22, a first upper plastic 30, a second upper plastic 40, a lower plastic 50, a first pressure block 61, and a second pressure block 62. The first pole 21 and the second pole 22 are located at opposite ends of the end cap assembly 100 in the longitudinal direction. The end cap 10 and the lower plastic 50 are stacked along the thickness direction of the end cap assembly 100. The first upper plastic 30 fits over the first pole 21 and insulates the end cap 10 from the first pole 21. The second upper plastic 40 fits over the second pole 22 and insulates the second pole 22 from the end cap 10. The first pole 21, the first upper plastic 30, and the first pressure block 61 are arranged in sequence and connected to the end cap 10 and the lower plastic 50. The first pole 21 is insulated and sealed from the end cap 10 by the cooperation of the first sealing ring 63, the first upper plastic 30, and the lower plastic 50. The second pole 22, the second upper plastic 40 and the second pressing block 62 are correspondingly arranged and connected to the end cover 10 and the lower plastic 50. The second pole 22 is insulated and sealed from the end cover 10 by the cooperation of the second upper plastic 40, the second sealing ring 64 and the lower plastic 50.

[0085] The first pole 21 includes a first pole body 211 and a first flange 212. The first pole 21 is a negative pole. The first pole 21 also includes a first metal portion 215 and a second metal portion 216, forming a connection interface 217 between the first metal portion 215 and the second metal portion 216. The second pole 22 includes a second pole body 221 and a second flange 222.

[0086] The first pressing block 61 includes a first through hole 613 , and a first sealing ring 63 is provided on one surface of the first pressing block 61 . The second pressing block 62 includes a second through hole 623 , and a second sealing ring 64 is provided on one surface of the second pressing block 62 .

[0087] The end cover 10 includes a first surface 11, a second surface 12, a first mounting groove 13, a first mounting hole 15, a second mounting hole 16, a second mounting groove 14, a first protrusion 17, and a second protrusion 18. The specific structure and matching relationship of these elements can be found in the detailed description of the first embodiment.

[0088] Referring to Figures 10 and 11 , the first upper plastic member 30 of this embodiment includes a first upper plastic body 31 and a first flange 32. The first upper plastic body 31 includes a first inner ring surface 311, a first stepped surface 312, and a first abutting surface 313. The first upper plastic body 31 and the first flange 32 together define the first terminal through-hole 33. Unlike the first embodiment, the first flange 32 includes a first sub-flange 321 and a first extended edge 322. The first sub-flange 321 and the first extended edge 322 are respectively projecting from the edges of the first stepped surface 312 and the first abutting surface 313, away from the center of the first upper plastic member 30. Along the Z-axis, which is also the height direction of the first upper plastic member, the first sub-flange 321 and the first extended edge 322 face away from each other.

[0089] In this embodiment, both the first sub-flange 321 and the first extension edge 322 are annular structures. It can be understood that, in one embodiment, the first upper plastic body 31 is an overall T-shaped cylindrical structure, comprising a first section (not labeled) and a second section (not labeled) connected to the first section. The first section is cylindrical, and the second section is an annular sheet. The second section is connected to one end of the first section in the axial direction and extends away from the axis of the first section. The first step surface 312 and the first abutting surface 313 are two surfaces along the thickness direction of the second section.

[0090] The first sub-flange 321 and the first extension edge 322 are coplanar with the surface facing away from the first upper plastic body 31. The first sub-flange 321 includes a first inner side surface 3210 and a first inclined surface 3211. The first inner side surface 3210 is connected to the first stepped surface 312, and there is an angle between the first inner side surface 3210 and the first stepped surface 312, which is 90 degrees in this embodiment. The first inclined surface 3211 connects the first inner side surface 3210 and the outer peripheral surface of the first sub-flange 321. The first inclined surface 3211 is inclined away from the first inner side surface 3210 and faces away from the first extension edge 322.

[0091] In one embodiment, the connection between the first inner side surface 3210 and the first inclined surface 3211 is a plane, named as the first plane 3213, and the first plane 3213 and the first step surface 312 are oriented in the same direction. The first inclined surface 3211 is inclined relative to the first plane 3213. In this embodiment, the width of the first plane is greater than or equal to 0.05 mm and less than or equal to 0.4 mm, wherein the width direction of the first plane is the radial direction of the first pole through hole. During the injection molding process of the first upper plastic 30, the connection between the first inclined surface 3211 and the first inner side surface 3210 is prevented from forming a sharp angle and causing a collapse angle, which affects the measurement of the overall dimensional accuracy of the first upper plastic, and improves the stability of the dimensional accuracy of the injection molding of the first upper plastic.

[0092] The first extending edge 322 is located outside the first upper plastic body 31 and is spaced apart from the first upper plastic body 31 . A first sub-holding gap 34 is formed between the first extending edge 322 and the first upper plastic body 31 .

[0093] In this embodiment, the second upper plastic member 40 has the same structure as the first upper plastic member 30 and includes a second upper plastic body 41 and a second flange 42. The second upper plastic body 41 includes a second inner ring surface 411, a second step surface 412, and a second abutting surface 413. The second upper plastic body 41 and the second flange 42 together define a second terminal through hole 43.

[0094] The second flange 42 includes a second sub-flange 421 and a second extended edge 422. The second sub-flange 421 and the second extended edge 422 are respectively projecting from the second stepped surface 412 and the second abutting surface 413, away from the center of the second upper plastic member 40. Along the Z-axis, which is also the height direction of the second upper plastic member 40, the second sub-flange 421 and the second extended edge 422 are disposed in opposite directions. In this embodiment, the second sub-flange 421 and the second extended edge 422 are both annular structures.

[0095] It can be understood that, in one embodiment, the second upper plastic body 41 is in the shape of a T-shaped cylinder as a whole, and includes a first section (not labeled in the figure) and a second section (not labeled in the figure) connected to the first section, the first section is cylindrical, and the second section is in the shape of a circular ring sheet; the second section is connected to one end of the first section in the axial direction and extends away from the axial direction of the first section, and the second step surface 412 and the second abutting surface 413 are two surfaces in the thickness direction of the second section.

[0096] The second sub-flange 421 and the second extension edge 422 are coplanar with the surface facing away from the first upper plastic body 31. The second sub-flange 421 includes a second inner side surface 4210 and a second inclined surface 4211. The second inner side surface 4210 is connected to the second stepped surface 412, and there is an angle between the second inner side surface 4210 and the second stepped surface 412, which is 90 degrees in this embodiment. The second inclined surface 4211 connects the second inner side surface 4210 and the outer circumference of the second sub-flange 421. The second inclined surface 4211 is inclined away from the second inner side surface 4210 and faces away from the second extension edge 422.

[0097] In one embodiment, the connection between the second inner side surface 4210 and the second inclined surface 4211 is a plane, named as the second plane 4213. The second plane 4213 and the second step surface 412 are oriented in the same direction. The second inclined surface 4211 is inclined relative to the second plane 4213.

[0098] The second extending edge 422 is located outside the second upper plastic body 41 and spaced apart from the outer circumference of the second upper plastic body 41 . A second sub-holding gap 44 is formed between the second extending edge 422 and the outer circumference of the second upper plastic body 41 .

[0099] Referring to Figure 12 , in this embodiment, the assembly positional relationships of the end cap 10, first and second poles 21 and 22, first and second upper plastics 30 and 40, lower plastic 50, and first and second pressure blocks 61 and 62 of the end cap assembly 100 can be specifically referenced to the assembly relationships of the first embodiment. The following describes only the assembly relationships of this embodiment that differ from the first embodiment. Specifically, after the end cap 10, first and second poles 21 and 22, first and second upper plastics 30 and 40, lower plastic 50, and first and second pressure blocks 61 and 62 are assembled and connected, the first upper plastic body 31 surrounds the first pole body 211 and the outer circumference of the first flange 212 at the periphery of the first pole body 211, with the first inner annular surface 311 facing the outer circumference of the first pole body 211. The first sub-flange 321 surrounds the outer circumference of the first flange 212, and the height of the first sub-flange 321 at least covers the connection (connection interface) between the first metal portion 215 and the second metal portion 216, thereby protecting the connection interface.

[0100] The first protrusion 17 is inserted into the first sub-retaining gap 34. The first protrusion 17 is clamped and limited between the outer peripheral surface of the first upper plastic body 31 and the first extended edge 322. The first abutting surface 313 of the first upper plastic body 30 abuts the first end surface 170 of the first protrusion 17 facing away from the end cap 10. A gap A is defined between the free end of the first extended edge 322 facing away from the first sub-flange 321 and the first surface 11 surrounding the first protrusion 17. This gap A prevents the first upper plastic body 30 from abutting the end cap 10, which could cause unstable compression of the first sealing ring 63. Furthermore, maintaining a certain size for gap A prevents the gap from being too small (i.e., when the gap is too small, the gap will absorb liquid that falls on the gap surface and draw the liquid into the gap), which could lead to capillary action of the liquid, thereby preventing the problem of electrolyte being introduced into the battery through gap A. The first inclined surface 3211 faces away from the first surface 11 and is inclined toward the first surface 11 . The first plane 3213 faces the same direction as the first surface 11 and is located at the end of the gap between the first pole 21 and the first flange 32 of the first upper plastic 30 .

[0101] In addition to achieving the technical effects described in the first embodiment, this embodiment also increases the creepage distance of the first terminal 21 along the first upper plastic member 30 to the end cap 10 because the first protrusion 17 is inserted into the first sub-retaining gap 34. Specifically, the first extended edge 322 and the first upper plastic body 31 enclose the first protrusion 17. Furthermore, in the radial direction of the first upper plastic member 30, the distance from the outer circumference of the first flange 32 to the peripheral wall of the first mounting slot 13 of the end cap 10 is reduced. The bottom wall of the first mounting slot 13 is thinner than other locations on the end cap 10. The contact width between the first upper plastic member 31 and the first protrusion 17 plus the overlap between the width of the first flange 32 and the bottom wall of the first mounting slot 13 in the direction of the end cap thickness enhances the strength of the bottom wall of the first mounting slot 13, specifically the strength around the first mounting hole 15. This increases the thrust applied to the first terminal 21 during assembly, ensuring assembly stability.

[0102] Moreover, the first flange 32 of this embodiment is provided with a first inclined surface 3211 on the surface facing away from the end cap 10 to prevent the first upper plastic 30 from shrinking and forming a pit during injection molding. When the electrolyte is injected, the first inclined surface 3211 can prevent the electrolyte from accumulating, thereby preventing the electrolyte from entering the interior of the end cap assembly through the gap between the first upper plastic 30 and the first pole 21.

[0103] Similarly, the assembly relationship between the second pole 22, the second upper plastic 40, the second pressure block 62, the second sealing ring 64, the end cap 10, and the lower plastic 50 of the second embodiment can refer to the description of the assembly of the first pole 21 and its related structures. The effects produced can also refer to the above description and are not repeated here.

[0104] Referring to FIG13 , the energy storage device (not shown) of the third embodiment of the present application includes an end cap assembly, a housing, and a battery cell. For the specific assembly relationship, please refer to the energy storage device 1000 of the first embodiment described in FIG2 . This embodiment differs from the energy storage device described in the first embodiment in the structure of the upper plastic in the end cap assembly 100 and the structure of the end cap 10 that cooperates with the upper plastic. It should be noted that in this embodiment, the parts that have the same structure as the end cap assembly 100 described in FIG3 are directly referenced and will not be described in detail.

[0105] Referring to Figure 14 , the end cap assembly 100 includes an end cap 10, a first pole 21, a second pole 22, a first upper plastic 30, a second upper plastic 40, a lower plastic 50, a first pressing block 61, and a second pressing block 62. The first pole 21 and the second pole 22 are located at opposite ends of the end cap assembly 100 in the longitudinal direction. The end cap 10 and the lower plastic 50 are stacked along the thickness of the end cap assembly 100. The first upper plastic 30 fits over the first pole 21 and insulates the end cap 10 from the first pole 21. The second upper plastic 40 fits over the second pole 22 and insulates the second pole 22 from the end cap 10. The first pole 21, the first upper plastic 30, and the first pressing block 61 are arranged in sequence and connected to the end cap 10 and the lower plastic 50. The first pole 21 is insulated and sealed from the end cap 10 by the cooperation of the first sealing ring 63, the first upper plastic 30, and the lower plastic 50. The second pole 22, the second upper plastic 40 and the second pressing block 62 are correspondingly arranged and connected to the end cover 10 and the lower plastic 50. The second pole 22 is insulated and sealed from the end cover 10 by the cooperation of the second upper plastic 40, the second sealing ring 64 and the lower plastic 50.

[0106] The first pole 21 includes a first pole body 211 and a first flange 212. The first pole 21 is a negative pole. The first pole 21 also includes a first metal portion 215 and a second metal portion 216, with a connection interface 217 formed between the first metal portion 215 and the second metal portion 216. The second pole 22 includes a second pole body 221 and a second flange 222. The first pressure block 61 includes a first through hole 613, and a first sealing ring 63 is provided on one surface of the first pressure block 61. The second pressure block 62 includes a second through hole 623, and a second sealing ring 64 is provided on one surface of the second pressure block 62. The end cover 10 includes a first surface 11, a second surface 12, a first mounting groove 13, a first mounting hole 15, a second mounting hole 16, a second mounting groove 14, a first protrusion 17, and a second protrusion 18. The specific structure and matching relationship of these components can be found in the detailed description of the first embodiment.

[0107] As shown in Figure 15 , the end cap 10 of this embodiment differs from the end cap 10 of the first embodiment in the structure of the first protrusion 17 and the second protrusion 18. The first protrusion 17 of this embodiment comprises a first boss 171 and a second boss 172. The first boss 171 is projecting from the first surface 11 and surrounds the first mounting hole 15. The first boss 171 is a circular protrusion, its inner surface connected to and coplanar with the wall of the first mounting hole 15. The end surface of the first boss 171 facing away from the first surface 11 is the first end surface 170. The second boss 172 is projecting from the edge of the first end surface 170, and the first and second bosses 171, 172 are coaxially arranged with the first mounting hole 15. The outer circumferential surfaces of the first and second bosses 171, 172 facing away from the axis of the first mounting hole 15 are coplanar. The height of the first protrusion 17 is the sum of the heights of the first and second bosses 171, 172. The first end surface 170 is the surface of the first boss 171 facing away from the end cap 10.

[0108] The second raised portion 18 of this embodiment includes a third boss 181 and a fourth boss 182. The third boss 181 is protruded from the first surface 11 and surrounds the second mounting hole 16. The third boss 181 is a circular annular protrusion, and its annular inner side surface is connected to and coplanar with the hole wall of the second mounting hole 16. The end face of the third boss 181 facing away from the first surface 11 is the second end face 180. The second boss 172 is protruded from the edge of the second end face 180, and the third boss 181 and the fourth boss 182 are coaxially arranged with the second mounting hole 16. The outer peripheral surfaces of the axes of the third boss 181 and the fourth boss 182 facing away from the second mounting hole 16 are coplanar. The height of the second raised portion 18 is the sum of the heights of the third boss 181 and the fourth boss 182.

[0109] Referring to Figure 16 , the first upper plastic member 30 of this embodiment includes a first upper plastic body 31 and a first flange 32. The first upper plastic body 31 includes a first inner ring surface 311, a first stepped surface 312, and a first abutting surface 313. The first upper plastic body 31 and the first flange 32 together define the first terminal through-hole 33. Unlike the first embodiment, the first flange 32 includes a first sub-flange 321 and a first extending edge 322. The first sub-flange 321 protrudes from the edge of the first stepped surface 312 away from the axis (center) of the first upper plastic member 30.

[0110] The first extension edge 322 is formed by bending one end of the first sub-flange 321 radially parallel to the first upper plastic 30 (the radial direction of the pole through-hole), then bending and extending in the axial direction parallel to the first upper plastic 30 (the axial direction of the pole through-hole). A third sub-holding gap 35 is defined between the first extension edge 322 and the first sub-flange 321. A first sub-holding gap 34 is defined between a portion of the first extension edge 322 and the first upper plastic body 31. The first sub-holding gap 34 and the third sub-holding gap 35 are connected and can be referred to as the first holding gap. In this embodiment, the first sub-flange 321, the first extension edge 322, and the first upper plastic body 31 are coaxially arranged. The first extension edge 322 has the largest diameter among the three. The first extension edge 322 surrounds the outer circumference of the first upper plastic body 31 and the first sub-flange 321.

[0111] It can be understood that, in one embodiment, the first upper plastic body 31 is in the shape of a T-shaped cylinder as a whole, and includes a first section (not labeled in the figure) and a second section (not labeled in the figure) connected to the first section. The first section is cylindrical, and the second section is in the shape of a circular ring sheet; the second section is connected to one end of the first section in the axial direction and extends away from the axial direction of the first section. The first step surface 312 and the first abutting surface 313 are two surfaces in the thickness direction of the second section.

[0112] The first flange 32 includes a first inner side surface 3210 and a first inclined surface 3211. The first inner side surface 3210 is the surface of the first sub-flange 321 facing the axis. The first inner side surface 3210 is connected to the first step surface 312, and there is an angle between the first inner side surface 3210 and the first step surface 312. The first inclined surface 3211 connects the first inner side surface 3210 and the outer peripheral surface of the first extension edge 322, and the first inclined surface 3211 is inclined away from the first inner side surface 3210. The first inclined surface 3211 of this embodiment is formed jointly by the end faces of the first sub-flange 321 and the first extension edge 322 in the axial direction. In this embodiment, the first inclined surface 3211 and the first inner side surface 3210 can also be a planar connection, as described in the first embodiment, and will not be repeated here.

[0113] In this embodiment, the second upper plastic member 40 has the same structure as the first upper plastic member 30 and includes a second upper plastic body 41 and a second flange 42. The second upper plastic body 41 includes a second inner ring surface 411, a second step surface 412, and a second abutting surface 413. The second upper plastic body 41 and the second flange 42 together define a second terminal through hole 43.

[0114] The second flange 42 includes a second sub-flange 421 and a second extension edge 422. The second sub-flange 421 is respectively protruded from the second step surface 412 and the second abutting surface 413 away from the axis of the second upper plastic 40. In this embodiment, the second sub-flange 421 and the second extension edge 422 are both annular structures.

[0115] The second extension edge 422 is formed by bending one end of the second sub-flange 421 parallel to the radial direction of the second upper plastic member 40, then bending and extending parallel to the axial direction of the second upper plastic member 40. A fourth sub-retaining gap 45 is defined between the second extension edge 422 and the second sub-flange 421. A second sub-retaining gap 44 is defined between a portion of the second extension edge 422 and the second upper plastic member 41. The second sub-retaining gap 44 and the fourth sub-retaining gap 45 are connected and can be referred to as the second retaining gap. In this embodiment, the second extension edge 422 is coaxial with the second sub-flange 421 and the second upper plastic member 41.

[0116] The second flange 42 includes a second inner side surface 4210 and a second inclined surface 4211. The second inner side surface 4210 is the surface of the first sub-flange 321 that faces the axis. The second inner side surface 4210 is connected to the first stepped surface 312, and there is an angle between the second inner side surface 4210 and the first stepped surface 312. The second inclined surface 4211 connects the second inner side surface 4210 and the outer circumference of the first extension edge 322, and the second inclined surface 4211 is inclined away from the second inner side surface 4210. In this embodiment, the second inclined surface 4211 is formed by the end surfaces of the second sub-flange 421 and the second extension edge 422 in the axial direction.

[0117] Referring to Figure 17 , in this embodiment, the assembly positional relationships of the end cap 10, first and second poles 21 and 22, first and second upper plastics 30 and 40, lower plastic 50, and first and second pressure blocks 61 and 62 of the end cap assembly 100 can be specifically referenced to the assembly relationships of the first embodiment. The following describes only the assembly relationships of this embodiment that differ from the first embodiment. Specifically, after the end cap 10, first and second poles 21 and 22, first and second upper plastics 30 and 40, lower plastic 50, and first and second pressure blocks 61 and 62 are assembled and connected, the first upper plastic body 31 surrounds the first pole body 211 and the surface of the first flange 212 at the periphery of the first pole body 211, with the first inner annular surface 311 facing the outer periphery of the first pole body 211. The first sub-flange 321 surrounds the outer periphery of the first flange 212 and covers at least the connection (connection interface) between the first metal portion 215 and the second metal portion 216, thereby protecting the connection interface.

[0118] The first boss 171 of the first raised portion 17 is inserted into the first sub-holding gap 34, and the second boss 172 is inserted into the third sub-holding gap 35. The first abutting surface 313 of the first upper plastic 30 abuts against the first end surface 170 of the first raised portion 17 facing away from the end cap 10. A gap A is defined between the free end surface of the first extended edge 322 facing away from the first sub-flange 321 and the first surface 11 surrounding the first raised portion 17. Gap A prevents the upper plastic from abutting against the end cap 10, causing unstable compression of the first sealing ring 63. Furthermore, ensuring a certain size for gap A prevents the capillary effect of the liquid caused by the gap being too small (i.e., when a gap is too small, the gap will absorb liquid that falls on the gap surface and draw the liquid into the gap), thereby preventing the problem of electrolyte being introduced into the battery through gap A. The first inclined surface 3211 faces away from the first surface 11 and is inclined toward the first surface 11.

[0119] In this embodiment, in addition to achieving the technical effects described in the first embodiment, the first boss 171 and the second boss 172 are stacked to form the first raised portion 17, which raises the gap between the first upper plastic 30 and the first terminal 21 compared to the end cap 10, and ensures the overall thickness uniformity of the first upper plastic 30. This can prevent uneven thickness of the upper plastic, which leads to pits on the surface due to inconsistent cooling speeds during the injection molding process, and solves the technical problem of electrolyte accumulating in the pits and overflowing and flowing into the interior of the end cap. At the same time, in the radial direction of the first upper plastic 30, the distance from the outer peripheral surface of the first flange 32 to the peripheral wall of the first mounting groove 13 of the end cover 10 is reduced, and the bottom wall of the first mounting groove 13 is thinner than other positions of the end cover 10. The contact width between the first upper plastic body 31 and the first protrusion 17 plus the width of the first flange 32 overlaps with the bottom wall of the first mounting groove 13 in the thickness direction of the end cover. This can improve the strength of the bottom wall of the first mounting groove 13, that is, the strength around the first mounting hole 15. When the first pole 21 is assembled, the thrust on the first pole 21 can be increased to ensure assembly stability.

[0120] Moreover, the surface of the first flange 32 of this embodiment facing away from the end cover 10 is provided with a first inclined surface 3211, which is inclined away from the first pole 21 to prevent the first upper plastic 30 from shrinking and forming a pit during injection molding. When the electrolyte is injected, the electrolyte falling on the first inclined surface will be retained due to the inclined surface. The first inclined surface 3211 can prevent the accumulation of electrolyte and prevent the electrolyte from entering the interior of the end cover assembly through the gap between the first upper plastic 30 and the first pole 21.

[0121] Similarly, the assembly relationship between the second pole 22, the second upper plastic 40, the second pressure block 62, the second sealing ring 64, the end cap 10, and the lower plastic 50 of the second embodiment can refer to the description of the assembly of the first pole 21 and its related structures. The effects produced can also refer to the above description and are not repeated here.

[0122] The above are only some of the embodiments and implementations of this application. The scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An end cap assembly, characterized in that: The end cap assembly includes an end cap, an upper plastic, and a pole; the end cap includes a first surface and a second surface, the first surface and the second surface are arranged in opposite directions along the thickness direction of the end cap assembly; the pole includes a pole body and a flange connected to one end of the pole body; The end cover further includes a mounting hole, the mounting hole passing through the first surface and the second surface, a raised portion is convexly provided on the first surface, the raised portion surrounds the mounting hole, and the raised portion is provided with an end surface; The upper plastic includes an upper plastic body and a flange. The upper plastic body includes a step surface and an abutting surface. Along the height direction of the upper plastic, the step surface and the abutting surface are arranged in opposite directions. The flange is protruding from the edge of the step surface away from the center of the upper plastic, and the upper plastic body and the flange enclose a pole through hole. The pole is passed through the pole through-hole, the surface of the flange facing the pole body abuts against the step surface, the flange surrounds the outer circumference of the flange, the upper plastic and the pole are accommodated in the mounting hole, the flange protrudes from the first surface, and along the thickness direction of the end cover assembly, the abutting surface abuts against the end surface.

2. The end cap assembly according to claim 1, wherein: The flange includes an inner side surface and an inclined surface, wherein the inclined surface connects the inner side surface and the outer peripheral surface of the flange, and the inclined surface is inclined away from the inner side surface and faces away from the upper plastic body.

3. The end cap assembly according to claim 2, wherein: The connection between the inner side surface and the inclined surface is a plane, and the width of the plane is greater than or equal to 0.05 mm and less than or equal to 0.4 mm.

4. The end cap assembly according to any one of claims 1 to 3, characterized in that: The flange includes a sub-flange and an extension edge, the sub-flange and the extension edge are respectively protruded from the edge of the step surface and the abutment surface away from the center of the upper plastic, the extension edge is spaced from the outer peripheral surface of the upper plastic body and forms a clamping gap; the protrusion extends into the clamping gap and is limited between the extension edge and the outer peripheral surface of the upper plastic body.

5. The end cap assembly according to claim 4, wherein: A gap is defined between an end surface of the extending edge facing the first surface of the end cover and the first surface.

6. The end cap assembly according to claim 4, wherein: The end cap assembly further includes a lower plastic, the lower plastic includes a lower plastic body, the lower plastic body includes a third surface and a fourth surface, the third surface and the fourth surface are arranged opposite to each other along the thickness direction of the lower plastic, The lower plastic includes an avoidance groove and an assembly hole. The avoidance groove is recessed from the fourth surface toward the third surface. The assembly hole passes through the third surface and the bottom wall of the avoidance groove. The lower plastic layer is stacked on the end cover, the third surface is opposite to the second surface, the mounting hole is opposite to the assembly hole, and the pole body passes through the assembly hole.

7. The end cap assembly according to claim 5, wherein: The end cover assembly also includes a lower plastic, a sealing ring and a pressing block. The lower plastic is laminated to the second surface, the pole body passes through the lower plastic, the sealing ring and the pressing block are sequentially sleeved on the end of the pole body away from the flange, the pressing block is abutted against the lower plastic, and the sealing ring is clamped between the pressing block and the end cover.

8. An end cap assembly, characterized in that: The end cap assembly includes an end cap, an upper plastic, and a pole; the end cap includes a first surface and a second surface, the first surface and the second surface are arranged in opposite directions along the thickness direction of the end cap assembly; the pole includes a pole body and a flange connected to one end of the pole body; The end cover further includes a mounting hole, the mounting hole passing through the first surface and the second surface, a raised portion is convexly provided on the first surface, and the raised portion surrounds the mounting hole; The raised portion includes a first boss and a second boss, the first boss is connected to the first surface, the first boss is provided with an end surface facing away from the first surface, and the second boss is provided on an edge of the end surface away from the axis of the mounting hole; The upper plastic includes an upper plastic body and a flange, and the upper plastic body and the flange enclose a pole through hole; the upper plastic body includes a step surface and an abutment surface, and along the axial direction of the pole through hole, the step surface and the abutment surface are arranged in opposite directions, and the flange includes a sub-flange and an extended edge, and the sub-flange is protruded from the edge of the step surface away from the center of the upper plastic. The extension edge is formed by bending and extending one end of the sub-flange, and then bending and extending in an axial direction parallel to the pole through hole. Along the radial direction of the pole through hole, the extension edge is spaced apart from the sub-flange and the upper plastic body. The pole is passed through the pole through-hole, the surface of the flange facing the pole body abuts against the step surface, the sub-flange surrounds the outer circumference of the flange, the upper plastic and the pole are accommodated in the mounting hole, the second boss extends between the extension edge and the sub-flange, the first boss extends between the extension edge and the upper plastic body, and along the thickness direction of the end cover assembly, the abutting surface abuts against the end surface.

9. The end cap assembly according to claim 8, wherein: The flange includes an inner side surface and an inclined surface, wherein the inclined surface connects the inner side surface and the outer peripheral surface of the flange, and the inclined surface is inclined away from the inner side surface and faces away from the upper plastic body.

10. The end cap assembly according to claim 8 or 9, characterized in that: A gap is defined between an end surface of the extending edge facing the end cover and the first surface.

11. The end cap assembly according to claim 8 or 9, characterized in that: The end cap assembly further includes a lower plastic, the lower plastic includes a lower plastic body, the lower plastic body includes a third surface and a fourth surface, the third surface and the fourth surface are arranged opposite to each other along the thickness direction of the lower plastic, The lower plastic includes an avoidance groove and an assembly hole. The avoidance groove is recessed from the fourth surface toward the third surface. The assembly hole passes through the third surface and the bottom wall of the avoidance groove. The lower plastic layer is stacked on the end cover, the third surface is opposite to the second surface, the mounting hole is opposite to the assembly hole, and the pole body passes through the assembly hole.

12. The end cap assembly according to claim 8 or 9, characterized in that: The pole includes a first metal part and a second metal part. The first metal part covers a side of the second metal part facing away from the flange of the pole. The connection interface between the first metal part and the second metal part is a curved surface.

13. An energy storage device, characterized in that: The battery cell comprises the end cap assembly, the shell and the battery cell according to any one of claims 1 to 12, wherein the battery cell is installed in the shell, and the end cap assembly is installed at one end of the shell and encapsulates the battery cell.

14. An electrical device, characterized in that: The energy storage device comprises the energy storage device as claimed in claim 13, wherein the energy storage device is used to supply power to electrical equipment.

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