End cap assemblies, energy storage devices and electrical equipment

Abstract

This application provides an end cap assembly, an energy storage device, and an electrical device, which can improve the sealing performance of the end cap assembly and prevent electrolyte from entering the gap between the cap body and the welding ring, thereby helping to improve the safety and reliability of the energy storage device. The end cap assembly includes a lower plastic, a cap body, an electrode post, a sealing ring, and a welding ring. The cap body is installed on one side of the lower plastic in the thickness direction. Along the thickness direction of the end cap assembly, the protrusion of the cap body is spaced apart from and opposite to the lower plastic. The electrode post passes through the through hole of the lower plastic and the assembly hole of the cap body. The welding ring is located on the side of the lower plastic away from the cap body and is sleeved on the electrode post. The sealing ring is sleeved on the electrode post and includes a sealing body and a sealing flange. The sealing body is sleeved on the electrode post and is clamped between the bottom wall of the assembly groove of the cap body and the surface of the welding ring facing the cap body. The sealing flange is connected to the side of the sealing body away from the electrode post and is arranged around the periphery of the sealing body and clamped between the protrusion and the lower plastic.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to an end cap assembly, an energy storage device, and an electrical appliance. Background Technology

[0002] A rechargeable battery, also known as a secondary battery or storage battery, is a battery that can be recharged after discharge to reactivate its active materials and continue to be used. The recyclable nature of rechargeable batteries has made them a primary power source for electrical devices. As the demand for rechargeable batteries increases, so do the requirements for their energy density and reliability. However, the end cap assemblies of existing rechargeable batteries have poor sealing, allowing electrolyte to easily seep into the gap between the cap and the weld ring, reducing the safety and reliability of the rechargeable battery. Summary of the Invention

[0003] This application provides an end cap assembly, an energy storage device, and an electrical device, which can improve the sealing performance of the end cap assembly and prevent electrolyte from entering the gap between the cap body and the welding ring, thereby helping to improve the safety and reliability of the energy storage device.

[0004] In a first aspect, this application provides an end cap assembly for use in an energy storage device. The end cap assembly includes a lower plastic component, a cap body, an electrode post, a sealing ring, and a welding ring. The lower plastic component has a through hole that penetrates the lower plastic component along its thickness direction. The cap body is mounted on one side of the lower plastic component along its thickness direction. The cap body has an assembly hole and an assembly groove. The assembly hole penetrates the cap body along its thickness direction and communicates with the through hole. The opening of the assembly groove is located on the surface of the cap body facing the lower plastic component. The assembly groove surrounds the assembly hole and communicates with it. The cap body also has a protrusion located on the bottom wall of the assembly groove along the end cap. In the thickness direction of the component, the convex bulge and the lower plastic are spaced apart and opposite to each other. The pole is inserted through the through hole and the assembly hole. The welding ring is located on the side of the lower plastic away from the cover and is sleeved on the pole. The sealing ring is sleeved on the pole. The sealing ring includes a sealing body and a sealing flange. The sealing body is sleeved on the pole and is clamped between the bottom wall of the assembly groove and the surface of the welding ring facing the cover. The sealing flange is connected to the side of the sealing body away from the pole and is arranged around the periphery of the sealing body and is clamped between the convex bulge and the lower plastic.

[0005] The lower plastic part is further provided with a protrusion, which is connected to the wall of the through hole and is arranged around the center of the through hole. Along the thickness direction of the end cap assembly, the protrusion and the convex shroud are spaced apart and arranged opposite to each other; the sealing flange is clamped between the convex shroud and the protrusion.

[0006] Wherein, along the thickness direction of the end cap assembly, the thickness of the sealing flange is less than the thickness of the sealing body, and the compression amount of the sealing flange is less than the compression amount of the sealing body.

[0007] Wherein, the ratio a of the initial thickness of the sealing flange to the distance between the surface of the lower plastic facing the protrusion and the surface of the protrusion facing the lower plastic is 1.08≤a≤2.22; the ratio b of the initial thickness of the sealing body to the distance between the bottom wall of the assembly groove and the surface of the welding ring facing the cover is 1.31≤b≤1.92.

[0008] The protrusion and the bulge are both annular; the sealing ring has a central surface, which is perpendicular to the thickness direction of the sealing ring, and the sealing ring is mirror-symmetrical about the central surface along the thickness direction of the sealing ring.

[0009] The sealing ring further includes protruding teeth, which are connected to the side of the sealing body facing the pole and abut against the pole.

[0010] The protruding teeth are multiple in number and are arranged at intervals around the pole post.

[0011] The welding ring is provided with a clearance notch. The opening of the clearance notch is located on the surface of the welding ring facing the cover, and the clearance notch penetrates the circumferential side of the welding ring, thus avoiding the protrusion.

[0012] The clearance notch includes a sidewall surface, which is arranged around the periphery of the pole post and is located between the surface of the convex bulge facing the pole post and the periphery of the pole post.

[0013] The lower plastic includes a first surface facing the cover body. The first surface is provided with a guide block. The guide block is arranged around the periphery of the through hole and installed in the assembly groove. It is located on the side of the sealing flange away from the sealing body. The guide block includes a guide surface located on the side of the guide block away from the through hole. The guide surface includes a first end close to the first surface and a second end opposite to the first end. The distance between the guide surface and the first surface gradually increases from the first end to the second end.

[0014] The cover body is provided with a mounting groove, the opening of which is located on the surface of the cover body away from the lower plastic. The mounting groove surrounds the assembly hole and is spaced apart from it. The end cap assembly also includes an upper plastic, which includes a main body and a protrusion. The main body is sleeved on the pole post and connected between the pole post and the cover body. The protrusion is connected to the side of the main body facing the cover body and fills the mounting groove.

[0015] The peripheral side of the protrusion protrudes relative to the peripheral side of the first main body.

[0016] The end cap assembly further includes a top patch, which is installed on the side of the cap body opposite to the lower plastic and covers at least part of the protrusion.

[0017] The pole includes a flange portion located on the side of the main body facing away from the cover. The main body includes a connecting surface facing away from the cover, the connecting surface being arranged around the peripheral side of the flange portion. The connecting surface includes a first side close to the flange portion and a second side facing away from the first side. From the first side to the second side, the distance between the connecting surface and the surface of the cover facing the main body gradually decreases.

[0018] The connecting surface is an arc-shaped surface.

[0019] The first side is spaced apart from the peripheral side of the flange.

[0020] Secondly, this application also provides an energy storage device, including a housing and an end cap assembly as described in any of the preceding claims, the end cap assembly being mounted on the housing and closing the opening of the housing.

[0021] Thirdly, this application also provides an electrical device, including the energy storage device described above, wherein the energy storage device supplies power to the electrical device.

[0022] In the end cap assembly provided in this application, by clamping the sealing flange of the sealing ring between the cap body and the lower plastic, and by clamping the sealing body between the cap body and the welding ring, the sealing flange can achieve sealing between the cap body and the lower plastic, and between the cap body and the welding ring when it is compressed. This improves the sealing performance of the end cap assembly, thereby preventing the electrolyte inside the energy storage device from seeping from the cap body into the space between the cap body and the welding ring. This avoids short circuit breakdown problems in the energy storage device during short circuit and withstand voltage tests, prevents the energy storage device from catching fire or exploding, and thus helps to improve the safety and reliability of the energy storage device. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0024] Figure 1 This is a schematic diagram of the energy storage device provided in the embodiments of this application;

[0025] Figure 2 yes Figure 1 The diagram shows the structure of the end cap assembly in the energy storage device.

[0026] Figure 3 yes Figure 2 The exploded structural diagram of the end cap assembly shown;

[0027] Figure 4 yes Figure 2 The diagram shows a cross-sectional view of the end cap assembly after it has been cut along point AA.

[0028] Figure 5 yes Figure 3 The diagram shows the structure of the lower plastic part in the end cap assembly.

[0029] Figure 6 yes Figure 5 The diagram below shows the structure of the plastic after it has been cut open along the BB section.

[0030] Figure 7 yes Figure 3 The diagram shows the structure of the end cap assembly and the explosion-proof valve.

[0031] Figure 8 yes Figure 7 A schematic diagram of the cross-sectional structure of the cover after it is cut along point CC.

[0032] Figure 9 yes Figure 3 An exploded view of the first pole post unit in the end cap assembly shown.

[0033] Figure 10 yes Figure 9 A schematic diagram of the cross-sectional structure of the first upper plastic part of the first pole post unit after being cut along DD;

[0034] Figure 11 yes Figure 9 A schematic diagram of the cross-sectional structure of the first pole post in the first pole post unit shown, after being cut along EE.

[0035] Figure 12 yes Figure 9 A schematic diagram of the cross-sectional structure of the first welding ring in the first pole post unit after being cut along FF;

[0036] Figure 13 yes Figure 9A schematic diagram of the cross-sectional structure of the first sealing ring in the first pole unit after being cut along GG;

[0037] Figure 14 yes Figure 3 An exploded view of the second pole post unit in the end cap assembly shown.

[0038] Figure 15 yes Figure 14 A schematic diagram of the structure of the second upper plastic section after being cut open along HH in the second pole unit shown;

[0039] Figure 16 yes Figure 14 A schematic diagram of the structure of the second pole column in the second pole column unit after being cut open at point II;

[0040] Figure 17 yes Figure 14 A schematic diagram of the structure of the second welding ring in the second pole unit after being cut open along JJ;

[0041] Figure 18 yes Figure 14 The diagram shows the structure of the second sealing ring after being cut open along point KK in the second pole unit.

[0042] The names corresponding to the labels in the figure are:

[0043] Energy storage device 100, housing 110, end cap assembly 120, lower plastic 10, cover 20, explosion-proof valve 30, first pole unit 40, second pole unit 50, first surface 10a, second surface 10b, explosion-proof fence 101, liquid inlet 102, first through hole 103, second through hole 104, first protrusion 11, second protrusion 12, first guide block 13, second guide block 14, first guide surface 131, first end 131a, second end 131b, second guide surface 141, first surface 20a, second surface 20b, explosion-proof Hole 201, Injection Hole 202, First Assembly Hole 203, Second Assembly Hole 204, Mounting Groove 205, First Assembly Groove 206, Second Assembly Groove 207, First Protrusion 21, Second Protrusion 22, Protective Sheet 60, First Upper Plastic 41, First Electrode 42, First Sealing Ring 43, First Welding Ring 44, First Mounting Hole 411, First Mating Groove 412, First Main Body 413, First Extension 414, Protrusion 415, First Mating Surface 401, First Connecting Surface 402, First Side 402a, Second Side 402b, First Flange 421, First mounting part 422, First fixing part 423, First assembly part 423a, First mating part 423b, First welding ring body 441, First retaining ring 442, First mating hole 443, First clearance notch 444, First side wall surface 444a, First sealing body 431, First sealing flange 432, First tooth 433, First center surface 43a, Second upper plastic 51, Second pole post 52, Second sealing ring 53, Second welding ring 54, Second mounting hole 511, Second mating groove 512, Second body part 51 3. Second extension 514, second mating surface 501, second connecting surface 502, second flange 521, second fixing part 523, second assembly part 523a, second mating part 523b, second welding ring body 541, second retaining ring 542, second mating hole 543, second clearance notch 544, second side wall surface 544a, second sealing body 531, second sealing flange 532, second protruding tooth 533, second center surface 53a, top plate 70, first clearance hole 701, second clearance hole 702, third clearance hole 703. Detailed Implementation

[0044] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0045] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of the energy storage device 100 provided in the embodiments of this application. For ease of description, the length direction of the energy storage device 100 is defined as the X-axis direction, the width direction of the energy storage device 100 is defined as the Y-axis direction, and the height direction of the energy storage device 100 is defined as the Z-axis direction. The X-axis direction, Y-axis direction, and Z-axis direction are all perpendicular to each other.

[0046] Energy storage device 100 includes a housing 110, a winding core (not shown), and an end cap assembly 120. The housing 110 has an opening (not shown) and a receiving cavity (not shown), the opening communicating with the receiving cavity. The winding core is received in the receiving cavity. The receiving cavity also serves to contain electrolyte, in which the winding core is immersed. The end cap assembly 120 is mounted on the housing 110 and closes the opening of the housing 110. Exemplarily, the energy storage device 100 is a prismatic battery. In some other embodiments, the energy storage device 100 may also be a cylindrical battery or other types of batteries.

[0047] Please see Figures 2 to 4 , Figure 2 yes Figure 1 The diagram shows the structure of the end cap assembly 120 in the energy storage device 100. Figure 3 yes Figure 2 The exploded structural diagram of the end cap assembly 120 shown is as follows: Figure 4 yes Figure 2 The diagram shows a cross-sectional view of the end cap assembly 120 after it has been cut along line AA. "Cut along line AA" means cut along the plane containing line AA; similar descriptions in the following text can be understood in the same way.

[0048] The end cap assembly 120 includes a lower plastic 10, a cover body 20, an explosion-proof valve 30, a first pole unit 40, and a second pole unit 50. The lower plastic 10 is installed on one side of the cover body 20 in the thickness direction. The explosion-proof valve 30, the first pole unit 40, and the second pole unit 50 are all installed on the cover body 20. Along the length of the energy storage device 100, the first pole unit 40 and the second pole unit 50 are located on opposite sides of the explosion-proof valve 30.

[0049] Please refer to the following: Figure 4 , Figure 5 and Figure 6 , Figure 5 yes Figure 3 The diagram shows the structure of the lower plastic 10 in the end cap assembly 120. Figure 6 yes Figure 5 The diagram shows the structure of the lower plastic 10 after it is cut open along BB.

[0050] The lower plastic 10 includes a first surface 10a and a second surface 10b, which are arranged opposite to each other along the thickness direction of the lower plastic 10. The first surface 10a is the surface of the lower plastic 10 facing away from the housing 110, and the second surface 10b is the surface of the lower plastic 10 facing the housing 110. The lower plastic 10 also includes an explosion-proof barrier 101, which penetrates through the first surface 10a and the second surface 10b of the lower plastic 10. Specifically, the explosion-proof barrier 101 is located in the middle of the lower plastic 10.

[0051] In this embodiment, the lower plastic 10 is further provided with a liquid inlet hole 102, a first through hole 103, and a second through hole 104. The liquid inlet hole 102, the first through hole 103, and the second through hole 104 all penetrate the first surface 10a and the second surface 10b of the lower plastic 10 along the thickness direction (Z-axis direction in the figure), and are spaced apart from each other. Specifically, along the length direction (X-axis direction in the figure) of the energy storage device 100, the liquid inlet hole 102 is located in the middle of the lower plastic 10 and on one side of the explosion-proof fence 101, and is spaced apart from the explosion-proof fence 101.

[0052] Along the length of the energy storage device 100 (X-axis direction in the figure), both the first through hole 103 and the second through hole 104 are located at the edge of the lower plastic 10 and are spaced apart from the liquid inlet hole 102 and the explosion-proof fence 101. In this embodiment, specifically, the first through hole 103 is located on the side of the liquid inlet hole 102 away from the explosion-proof fence 101, and the second through hole 104 is located on the side of the explosion-proof fence 101 away from the liquid inlet hole 102.

[0053] In this embodiment, the lower plastic 10 is further provided with a first protrusion 11 and a second protrusion 12. The first protrusion 11 is fixedly connected to the wall of the first through hole 103. The second protrusion 12 is fixedly connected to the wall of the second through hole 104. Along the length direction of the lower plastic 10 (the X-axis direction in the figure), the second protrusion 12 and the first protrusion 11 are spaced apart. For example, both the first protrusion 11 and the second protrusion 12 are annular.

[0054] In addition, the lower plastic 10 is also provided with a first guide block 13 and a second guide block 14. Specifically, the first surface 10a is provided with a first guide block 13 and a second guide block 14. The first guide block 13 is disposed around the periphery of the first through hole 103. For example, there are multiple first guide blocks 13. Multiple first guide blocks 13 are disposed at intervals around the first protrusion 11. Each first guide block 13 includes a first guide surface 131. The first guide surface 131 is located on the side of the first guide block 13 facing away from the first through hole 103. Specifically, the first guide surface 131 includes a first end 131a near the first surface 10a and a second end 131b disposed opposite to the first end 131a. In the direction from the first end 131a to the second end 131b, the distance between the first guide surface 131 and the first surface 10a of the lower plastic 10 gradually increases.

[0055] The second guide block 14 is fixedly connected to the side of the second protrusion 12 facing away from the second through hole 104. In this embodiment, the structure of the second guide block 14 is the same as that of the first guide block 13 described above. For example, there can be multiple second guide blocks 14. Multiple second guide blocks 14 are spaced apart around the periphery of the second protrusion 12. Each second guide block 14 includes a second guide surface 141. The structure of the second guide surface 141 and the positional relationship of the second guide surface 141 in the second guide block 14 can be referred to the relevant description of the structure of the first guide surface 131 and the positional relationship of the first guide surface 131 in the first guide block 13, which will not be repeated here.

[0056] Please refer to the following: Figure 4 , Figure 7 and Figure 8 , Figure 7 yes Figure 3 The diagram shows the structure of the cover body 20 and the explosion-proof valve 30 in the end cap assembly 120. Figure 8 yes Figure 7 The diagram shows a cross-sectional view of the cover 20 after it is cut along CC.

[0057] The cover 20 includes a first surface 20a and a second surface 20b, which are arranged opposite to each other along the thickness direction of the cover 20 (Z-axis direction in the figure). The first surface 20a is the side of the cover 20 that faces away from the lower plastic 10, and the second surface 20b is the side of the cover 20 that faces the lower plastic 10.

[0058] The cover 20 is also provided with an explosion-proof hole 201, a liquid injection hole 202, a first assembly hole 203, a second assembly hole 204, a mounting groove 205, a first assembly groove 206, and a second assembly groove 207. Among them, the explosion-proof hole 201, the liquid injection hole 202, the first assembly hole 203, and the second assembly hole 204 all penetrate the first surface 20a and the second surface 20b of the cover 20 along the thickness direction (Z-axis direction in the figure) and are spaced apart from each other.

[0059] Specifically, both the explosion-proof hole 201 and the liquid injection hole 202 are located in the middle of the cover 20. The explosion-proof hole 201 can connect to the interior of the energy storage device 100 through the explosion-proof grille 101. Along the length of the cover 20, the liquid injection hole 202 is located on one side of the explosion-proof hole 201. The liquid injection hole 202 is connected to the liquid inlet hole 102 of the lower plastic 10. Electrolyte can be injected into the housing 110 (e.g., through the liquid injection hole 202 of the cover 20 and the liquid inlet hole 102 of the lower plastic 10) in sequence. Figure 1 The cavity shown is used to fill the electrolyte of the energy storage device 100.

[0060] Along the length of the energy storage device 100 (X-axis direction in the diagram), both the first mounting hole 203 and the second mounting hole 204 are located on the edge of the cover 20, and are respectively located on opposite sides of the explosion-proof hole 201 and the liquid injection hole 202. Specifically, the first mounting hole 203 is located on the side of the liquid injection hole 202 away from the explosion-proof hole 201. The second mounting hole 204 is located on the side of the explosion-proof hole 201 away from the liquid injection hole 202. The first mounting hole 203 communicates with the first through hole 103 of the lower plastic 10 to facilitate the installation of the first pole post unit 40. The second mounting hole 204 communicates with the second through hole 104 of the lower plastic 10 to facilitate the installation of the second pole post unit 50.

[0061] The opening of the mounting groove 205 is located on the first surface 20a of the cover 20. The mounting groove 205 is recessed from the first surface 20a toward the second surface 20b. The mounting groove 205 is disposed around the periphery of the first mounting hole 203 and is spaced apart from the first mounting hole 203. In some other embodiments, when the injection hole 202 is disposed between the explosion-proof hole 201 and the second mounting hole 204, that is, when the second mounting hole 204 is disposed close to the injection hole 202, the mounting groove 205 may also be disposed around the periphery of the second mounting hole 204 and spaced apart from the second mounting hole 204.

[0062] In this embodiment, the openings of the first mounting groove 206 and the second mounting groove 207 are both located on the second surface 20b of the cover 20. The first mounting groove 206 is recessed from the second surface 20b toward the first surface 20a and penetrates the wall of the first mounting hole 203. The first mounting groove 206 surrounds the first mounting hole 203 and communicates with it.

[0063] The second mounting groove 207 is recessed from the second surface 20b toward the first surface 20a and penetrates the wall of the second mounting hole 204. The second mounting groove 207 is disposed around the second mounting hole 204 and communicates with the second mounting hole 204. Along the length of the cover plate, the second mounting groove 207 and the first mounting groove 206 are spaced apart.

[0064] During the assembly of the cover 20 and the lower plastic 10, since the first guide surface 131 of the first guide block 13 and the second guide surface 141 of the second guide block 14 in the lower plastic 10 are both inclined, the first guide surface 131 and the second guide surface 141 can guide and position the installation of the lower plastic 10. Specifically, the first guide block 13 is installed in the first assembly groove 206 so that the first through hole 103 is aligned and connected with the first assembly hole 203. The second guide block 14 is installed in the second assembly groove 207 so that the second through hole 104 of the lower plastic 10 is aligned and connected with the second assembly hole 204. This arrangement prevents the lower plastic 10 from shifting during assembly with the cover 20, ensuring precise alignment between the lower plastic 10 and the cover 20. This guarantees precise assembly of the first pole post unit 40 and the second pole post unit 50 with the cover 20 and the lower plastic 10, avoiding assembly defects in the end cap assembly 120.

[0065] Furthermore, the cover 20 has a first protrusion 21 and a second protrusion 22 on the side facing the lower plastic 10. The first protrusion 21 is located on the bottom wall of the first mounting groove 206 and surrounds the periphery of the first mounting hole 203. For example, the first protrusion 21 is generally annular. Along the thickness direction of the end cap assembly 120, the first protrusion 21 is spaced apart from and opposite to the first protrusion 11 of the lower plastic 10. The second protrusion 22 is located on the bottom wall of the second mounting groove 207 and surrounds the periphery of the second mounting hole 204. For example, the second protrusion 22 is generally annular. Along the thickness direction of the end cap assembly 120, the second protrusion 22 is spaced apart from and opposite to the first protrusion 11 of the lower plastic 10.

[0066] It is understandable that by providing a first protrusion 21 and a second protrusion 22 on the side of the cover 20 facing the lower plastic 10, the thickness of the cover 20 can be increased, thereby enhancing the structural strength of the cover 20, which in turn helps to improve the reliability of the cover 20 and extend its service life.

[0067] Please continue reading. Figure 4 and Figure 7 The explosion-proof valve 30 is installed in the explosion-proof hole 201 and fixedly connected to the hole wall of the explosion-proof hole 201. For example, the explosion-proof valve 30 can be fixedly connected to the hole wall of the explosion-proof hole 201 by welding. It is understood that since the explosion-proof hole 201 connects the interior and exterior of the energy storage device 100, when the internal gas pressure of the energy storage device 100 is too high, the explosion-proof valve 30 will rupture under the pressure. The gas inside the energy storage device 100 can then be discharged to the exterior of the energy storage device 100 in a timely manner through the explosion-proof fence 101 of the lower plastic 10 and the explosion-proof hole 201, preventing the energy storage device 100 from exploding and improving the reliability of the energy storage device 100.

[0068] In this embodiment, the end cap assembly 120 may further include a protective plate 60. The protective plate 60 is installed on the cover plate and covers the explosion-proof hole 201. The protective plate 60 is used to protect the explosion-proof valve 30, preventing damage to the explosion-proof valve 30 from the external environment and external forces, thereby preventing the explosion-proof valve 30 from being accidentally activated and ensuring the high reliability of the energy storage device 100.

[0069] Please refer to the following: Figure 4 , Figure 9 and Figure 10 , Figure 9 yes Figure 3 An exploded view of the first pole post unit 40 in the end cap assembly 120 shown. Figure 10 yes Figure 9 The diagram shows a cross-sectional view of the first upper plastic 41 in the first pole unit 40 after it is cut along DD.

[0070] The first pole unit 40 includes a first upper plastic 41, a first pole 42, a first sealing ring 43, and a first welding ring 44, all of which are sleeved on the first pole 42. The first upper plastic 41 is mounted on the cover 20 and located between the cover 20 and the first pole 42. Specifically, the first upper plastic 41 has a first mounting hole 411 and a first mating groove 412. The first mounting hole 411 penetrates the first upper plastic 41 along its thickness direction and is coaxial with and communicates with the first assembly hole 203 of the cover 20. The opening of the first mating groove 412 is located on the surface of the first upper plastic 41 facing away from the cover 20. The first mating groove 412 is recessed from the surface of the first upper plastic 41 facing away from the cover 20 towards the cover 20, penetrates the wall of the first mounting hole 411, and communicates with the first mounting hole 411.

[0071] The first upper plastic 41 also includes a first main body portion 413, a first extension portion 414, and a protrusion portion 415, both of which are fixedly connected to the first main body portion 413. The first main body portion 413 is sleeved on the first pole post 42 and located between the first pole post 42 and the cover body 20. The first main body portion 413 has a first mating groove 412 and a first mounting hole 411. The opening of the first mating groove 412 is located on the surface of the first main body portion 413 opposite to the cover body 20.

[0072] The first main body 413 also includes a first mating surface 401 and a first connecting surface 402 facing away from the cover 20. The opening of the first mating groove 412 is located on the first mating surface 401. For example, the first mating surface 401 is planar, facilitating its engagement and contact with the first pole post 42. The first connecting surface 402 is fixedly connected to the first mating surface 401 and surrounds its periphery. For example, the first connecting surface 402 is arc-shaped. The first connecting surface 402 includes a first side 402a near the first pole post 42 and a second side 402b opposite to the first side 402a. The distance between the first connecting surface 402 and the first surface 20a of the cover 20 gradually decreases from the first side 402a to the second side 402b. That is, the first connecting surface 402 is an inclined arc-shaped surface.

[0073] Understandably, after the energy storage device 100 is filled with electrolyte, when the filling nozzle is withdrawn from the filling hole 202, electrolyte may easily splash onto the surface of the first upper plastic 41. By providing a first connecting surface 402 on the first upper plastic 41 and tilting the first connecting surface 402, electrolyte is less likely to remain on the first connecting surface 402, thereby preventing electrolyte crystallization on the surface of the first upper plastic 41. This helps maintain the clean appearance of the end cap assembly 120 and reduces the appearance defect rate of the energy storage device 100. At the same time, the tilted, arc-shaped first connecting surface 402 has a large area, making it easy to wipe even if electrolyte residue remains on the first connecting surface 402. This also helps prevent electrolyte crystallization on the first connecting surface 402, thus helping to maintain the clean appearance of the end cap assembly 120 and reduce the appearance defect rate of the energy storage device 100.

[0074] In this embodiment, both the first extension 414 and the protrusion 415 are fixedly connected to the side of the first main body 413 facing the cover 20. Specifically, the first extension 414 is arranged around the periphery of the first mounting hole 411. Specifically, the first extension 414 is mounted in the first mounting hole 203 of the cover 20.

[0075] The protrusion 415 is installed in the mounting groove 205 of the cover 20. This arrangement improves the assembly reliability between the first upper plastic 41 and the cover 20. In this embodiment, the protrusion 415 is spaced around the periphery of the first extension 414, and the outer peripheral side of the protrusion 415 protrudes relative to the outer peripheral side of the first main body 413. With this arrangement, the assembly gap between the first upper plastic 41 and the cover 20 can be extended outward, preventing electrolyte remaining on the surface of the first upper plastic 41 from flowing directly into the assembly gap between the first upper plastic 41 and the cover 20. This reduces the amount of electrolyte flowing into the assembly gap between the first upper plastic 41 and the cover 20 to a certain extent, and lowers the possibility of electrolyte crystallization in the assembly gap between the first upper plastic 41 and the cover 20.

[0076] Please refer to the following: Figure 9 and Figure 11 , Figure 11 yes Figure 9 A schematic diagram of the cross-sectional structure of the first pole post 42 in the first pole post unit 40 shown after being cut along EE.

[0077] The first electrode post 42 passes through the first mounting hole 411 of the upper plastic 41, the first assembly hole 203 of the cover 20, and the first through hole 103 of the lower plastic 10. Exemplarily, the first electrode post 42 is a positive electrode post and is made of aluminum. In some other embodiments, the first electrode post 42 may also be a negative electrode post; the embodiments of this application do not strictly limit this.

[0078] In this embodiment, the first pole post 42 includes a first flange portion 421, a first mounting portion 422, and a first fixing portion 423. Both the first mounting portion 422 and the first fixing portion 423 are located on one side of the first flange portion 421 in the thickness direction. Specifically, the first mounting portion 422 is fixedly connected to the first flange portion 421. The peripheral side surface of the first flange portion 421 protrudes relative to the peripheral side surface of the first mounting portion 422. The first fixing portion 423 is fixedly connected to the side of the first mounting portion 422 opposite to the first flange portion 421. Specifically, the first fixing portion 423 includes a first assembly portion 423a and a first mating portion 423b. The first mating portion 423b is connected to one side of the first assembly portion 423a, and the peripheral side surface of the first mating portion 423b is flush with the peripheral side surface of the first assembly portion 423a.

[0079] Specifically, the first flange portion 421 of the first pole post 42 is located on the side of the first main body portion 413 in the first upper plastic 41 that faces away from the cover body 20. The surface of the first flange portion 421 facing the first main body portion 413 abuts against the first mating surface 401. The peripheral side surface of the first flange portion 421 is spaced apart from the first connecting surface 402. Specifically, the first side 402a of the first connecting surface 402 is spaced apart from the peripheral side surface of the first flange portion 421. In this configuration, after the first electrode post 42 is assembled with the first upper plastic part 41, on the one hand, the first side 402a and the peripheral side of the first flange part 421 are spaced apart, and the first connecting surface 402 will not enter the assembly gap between the first electrode post 42 and the first upper plastic part 41, which facilitates wiping away the electrolyte remaining on the first connecting surface 402. On the other hand, the assembly gap between the first flange part 421 of the first electrode post 42 and the first main body part 413 is set in the horizontal direction, which prevents the electrolyte from entering the assembly gap between the first main body part 413 and the first flange part 421, thereby reducing the possibility of subsequent precipitation and crystallization of the electrolyte, which in turn helps to reduce the appearance defect rate of the energy storage device 100 and ensure the appearance cleanliness of the energy storage device 100.

[0080] The first mounting portion 422 of the first pole post 42 is installed in the first mating groove 412 of the first upper plastic 41. The first fixing portion 423 passes through the first mounting hole 411 of the first upper plastic 41, the first assembly hole 203 of the cover 20, and the first through hole 103 of the lower plastic 10. Specifically, the first assembly portion 423a of the first fixing portion 423 passes through the first mounting hole 411 and the first assembly hole 203, and the first mating portion 423b of the first fixing portion 423 passes through the first through hole 103. A portion of the first main body portion 413 is located between the first flange portion 421 and the cover 20, and another portion of the first main body portion 413 is located between the first mounting portion 422 and the cover 20. The first extension portion 414 of the first upper plastic 41 is located between the peripheral side of the first fixing portion 423 of the first pole post 42 and the wall of the first assembly hole 203. With this arrangement, short circuit problems caused by direct contact between the first pole post 42 and the cover 20 in the end cap assembly 120 can be avoided.

[0081] Please refer to the following: Figure 4 , Figure 9 and Figure 12 , Figure 12 yes Figure 9 The diagram shows a cross-sectional view of the first welding ring 44 in the first pole unit 40 after being cut along FF.

[0082] In this embodiment, the first welding ring 44 is located on the side of the cover 20 opposite to the first upper plastic 41 and is sleeved on the first pole post 42. Specifically, the first welding ring 44 is installed in the first through hole 103 of the lower plastic 10, abuts against the first protrusion 11, and is welded and fixed to the first pole post 42. Specifically, the first welding ring 44 includes a first welding ring body 441 and a first retaining ring 442, with the first retaining ring 442 fixedly connected to the first welding ring body 441. The first welding ring body 441 is provided with a first mating hole 443. The first mating hole 443 penetrates the first welding ring body 441 along its thickness direction. The first retaining ring 442 is located in the first mating hole 443 and is fixedly connected to the hole wall of the first mating hole 443. The thickness of the first retaining ring 442 is between 0.2 mm and 0.5 mm. The difference between the inner diameter d1 of the first retaining ring 442 and the diameter D1 of the first mating hole 443 is between 0.3 mm and 1 mm.

[0083] Specifically, the first welding ring body 441 is fitted onto the first mating portion 423b of the first fixing portion 423 in the first pole post 42. That is, the first mating portion 423b passes through the first mating hole 443. Along the thickness direction of the end cap assembly 120, the first retaining ring 442 is located on the side of the first mating portion 423b opposite to the first mounting portion 423a, and covers the gap between the first mating portion 423b and the first welding ring body 441. When the first welding ring 44 is welded to the first pole post 42, the first retaining ring 442 melts and fills the gap between the first welding ring body 441 and the first mating portion 423b of the first pole post 42.

[0084] In this embodiment, by setting a first retaining ring 442 on the first welding ring 44 and making the first retaining ring 442 block the assembly gap between the first assembly part 423a and the first welding ring body 441, when the first welding ring 44 and the first electrode post 42 are laser welded, the first retaining ring 442 will be melted by the laser first and fill the assembly gap between the first mating part 423b and the first welding ring body 441. This can prevent the laser from entering the assembly gap between the first mating part 423b and the first welding ring body 441, avoid the welding explosion problem caused by the first upper plastic 41 being burned, and thus help reduce the welding defect rate between the first electrode post 42 and the first welding ring 44. Meanwhile, the peripheral side surface of the first assembly part 423a is flush with the peripheral side surface of the first mating part 423b, so that there is no step structure at the mating position of the first welding ring body 441 and the first pole post 42. This can avoid the interference fit between the first welding ring body 441 and the first pole post 42, thereby preventing the first welding ring 44 and the first pole post 42 from forming a false sealing state. This will prevent products with abnormal sealing state from being undetected when the energy storage device 100 performs short circuit and withstand voltage tests, thereby preventing unqualified products from flowing out and helping to improve the production quality of the energy storage device 100.

[0085] In this embodiment, the first welding ring 44 is further provided with a first clearance notch 444. Specifically, the opening of the first clearance notch 444 is located on the surface of the first welding ring body 441 of the first welding ring 44 facing the cover 20. The first clearance notch 444 is recessed from the surface of the first welding ring body 441 facing the cover 20 in a direction away from the cover 20, and penetrates the peripheral side surface of the first welding ring body 441 of the first welding ring 44. The first clearance notch 444 is provided around the first mating hole 443 and is spaced apart from the first mating hole 443. The first clearance notch 444 avoids the first protrusion 11 of the lower plastic 10. With this configuration, on the one hand, the first protrusion 11 can be spaced out in the thickness direction of the end cap assembly 120, preventing it from being broken due to its thinness during the pressing of the first welding ring 44 and the first electrode post 42. This prevents electrolyte inside the energy storage device 100 from seeping into the space between the first welding ring 44 and the cover body 20 through the gap between the first welding ring 44 and the first protrusion 11 of the lower plastic 10, improving the insulation performance between the first welding ring 44 and the cover body 20, avoiding short circuits inside the end cap assembly 120, and also improving the assembly reliability of the first welding ring 44 and the lower plastic 10. On the other hand, it can also increase the area of ​​the pressing surface between the first welding ring 44 and the lower plastic 10, thereby extending the penetration path of the electrolyte and further improving the sealing performance of the end cap assembly 120.

[0086] Furthermore, the first clearance notch 444 includes a first sidewall 444a. The first sidewall 444a is disposed around the periphery of the first pole post 42. Specifically, the first sidewall 444a is disposed around the periphery of the first fixing portion 423 of the first pole post 42. In this embodiment, the first sidewall 444a is located between the surface of the first protrusion 21 of the cover 20 facing the first pole post 42 and the periphery of the first pole post 42. Specifically, the first sidewall 444a is located between the surface of the first protrusion 21 facing the first fixing portion 423 and the periphery of the first fixing portion 423. With this arrangement, the first sidewall 444a can be misaligned with the surface of the first protrusion 21 facing the first pole post 42.

[0087] Please refer to the following: Figure 4 , Figure 9 and Figure 13 , Figure 13 yes Figure 9 A schematic diagram of the cross-sectional structure of the first sealing ring 43 in the first pole unit 40 after being cut along GG.

[0088] The first sealing ring 43 is sleeved on the first fixing part 423 of the first pole post 42 and is clamped between the cover 20 and the lower plastic 10, and also between the cover 20 and the first welding ring 44. The first sealing ring 43 not only ensures the assembly stability between the first welding ring 44 and the cover 20, and between the lower plastic 10 and the cover 20, but also prevents the first welding ring 44 from directly contacting the cover 20 for electrical conduction, thus achieving insulation between the first welding ring 44 and the cover 20.

[0089] Specifically, the first sealing ring 43 includes a first sealing body 431, a first sealing flange 432, and a first tooth 433. The first sealing flange 432 and the first tooth 433 are both fixedly connected to the first sealing body 431 and are located on opposite sides of the first sealing body 431. Specifically, the first sealing body 431 is sleeved on the first fixing part 423 of the first pole post 42 and is clamped between the bottom wall of the first assembly groove 206 of the cover 20 and the surface of the first welding ring body 441 of the first welding ring 44 facing the cover 20. The first sealing body 431 seals the gap between the bottom wall of the first assembly groove 206 and the surface of the first welding ring body 441 of the first welding ring 44 facing the cover 20.

[0090] The first sealing flange 432 is connected to the side of the first sealing body 431 opposite to the first fixing part 423 of the first pole post 42, and is arranged around the periphery of the first sealing body 431, and is clamped between the first protrusion 21 of the cover 20 and the first protrusion 11 of the lower plastic 10. The first sealing flange 432 seals the gap between the first protrusion 11 of the lower plastic 10 and the first protrusion 21 of the cover 20. It can be understood that by misaligning the first side wall surface 444a of the first welding ring 44 with the surface of the first protrusion 21 facing the first pole post 42, the first sealing flange 432 can be provided with the maximum pressing area, thereby helping to improve the sealing performance between the cover 20 and the lower plastic 10.

[0091] In this embodiment, along the thickness direction of the end cap assembly 120, the thickness of the first sealing flange 432 is less than the thickness of the first sealing body 431, and the compression amount of the first sealing flange 432 is less than the compression amount of the first sealing body 431. In this embodiment, the ratio a1 of the initial thickness of the first sealing flange 432 to the distance between the surface of the lower plastic 10 facing the first protrusion 21 and the surface of the first protrusion 21 facing the lower plastic 10 is 1.08≤a1≤2.22. The ratio b1 of the initial thickness of the first sealing body 431 to the distance between the bottom wall of the first assembly groove 206 and the surface of the first welding ring 44 facing the cover 20 is 1.31≤b1≤1.92. Here, "initial thickness of the first sealing flange 432" refers to the thickness of the first sealing flange 432 before compression, and "initial thickness of the first sealing body 431" refers to the thickness of the first sealing body 431 before compression. With this setting, it can be ensured that the compression of the first sealing flange 432 is less than the compression of the first sealing body 431, thereby preventing the first sealing flange 432 from affecting the overall sealing performance of the end cap assembly 120.

[0092] It should be noted that in the actual production process, the dimensions and assembly tolerances of components such as the lower plastic 10 and the cover body 20 in the end cap assembly 120 need to be adjusted according to the product requirements in order to control the compression of the first sealing flange 432 and the first sealing body 431 of the first sealing ring 43.

[0093] Understandably, during the assembly of the end cap assembly 120, when the first welding ring 44 is welded to the first pole post 42, the first welding ring 44 will squeeze the lower plastic 10 and the first sealing ring 43. By firmly clamping the first sealing flange 432 of the first sealing ring 43 between the first protrusion 21 of the cover body 20 and the first protrusion 11 of the lower plastic 10, the first sealing flange 432 is compressed and seals the gap between the first protrusion 21 and the first protrusion 11, thereby achieving a seal between the cover body 20 and the lower plastic 10. This prevents the electrolyte inside the energy storage device 100 from seeping into the space between the cover body 20 and the first welding ring 44 through the gap between the first protrusion 21 of the cover body 20 and the first protrusion 11 of the lower plastic 10. This can prevent the energy storage device 100 from short-circuiting and breaking down during short-circuit and withstand voltage tests, prevent the energy storage device 100 from catching fire and exploding, and thus help improve the safety and reliability of the energy storage device 100.

[0094] The first protruding tooth 433 is connected to the side of the first sealing body 431 facing the first mounting portion 423a of the first pole post 42, and abuts against the first mounting portion 423a of the first pole post 42, so that the circumferential surface of the first mounting portion 423a of the first pole post 42 is spaced apart from the first sealing body 431. It can be understood that by setting the first protruding tooth 433 on the side of the first sealing body 431 of the first sealing ring 43 facing the first pole post 42, and abutting against the first pole post 42, the first sealing body 431 can be separated from the circumferential surface of the first pole post 42 during the compression of the first sealing ring 43. This avoids the false sealing state that occurs when the first sealing body 431 of the first sealing ring 43 adheres to the first pole post 42 or the first upper plastic 41 after compression. This can solve the problem that it is not easy to detect when the sealing performance of the weld or other sealing parts of the end cap assembly 120 is abnormal, thereby reducing the outflow rate of defective products and improving the production quality of the energy storage device 100.

[0095] In this embodiment, there are multiple first protrusions 433. These multiple first protrusions 433 are spaced apart around the first pole post 42. During the compression of the first sealing ring 43, all the multiple first protrusions 433 abut against the first pole post 42, preventing the first pole post 42 from shifting, thereby helping to ensure the high reliability of the end cap assembly 120.

[0096] In this embodiment, the first sealing ring 43 further includes a first central surface 43a. The first central surface 43a is perpendicular to the thickness direction of the first sealing ring 43 and passes through the first sealing body 431, the first sealing flange 432, and the first tooth 433. Along the thickness direction of the first sealing ring 43, the first sealing ring 43 is mirror-symmetrical about the first central surface 43a. With this configuration, during the assembly of the end cap assembly 120, there is no need to consider the orientation of the first sealing ring 43, thereby helping to reduce the assembly difficulty of the first sealing ring 43 in the end cap assembly 120, which in turn helps to speed up the production pace of the end cap assembly 120 and improve production efficiency.

[0097] Furthermore, when the first sealing ring 43 is assembled with the lower plastic 10, the plurality of first guide blocks 13 of the lower plastic 10 are all located on the side of the first sealing flange 432 facing away from the first sealing body 431. With this arrangement, the assembly position of the first sealing ring 43 in the end cap assembly 120 can be limited, and the compression space of the first sealing ring 43 can be ensured without affecting it when the first sealing ring 43 is compressed.

[0098] Please see Figure 4 , Figure 14 and Figure 15 , Figure 14 yes Figure 3 An exploded view of the second pole post unit 50 in the end cap assembly 120 shown. Figure 15yes Figure 14 The diagram shows the structure of the second upper plastic 51 in the second pole unit 50 after being cut open along HH.

[0099] The second pole post unit 50 includes a second upper plastic 51, a second pole post 52, a second sealing ring 53, and a second welding ring 54. The structure of each component in the second pole post unit 50, the assembly relationship between components, and the assembly relationship between components and the lower plastic 10 and the cover 20 can be found in the relevant description of the first pole post unit 40 above, and will not be repeated here.

[0100] In this embodiment, the structure of the second upper plastic 51 is similar to that of the first upper plastic 41. The difference lies in that the second upper plastic 51 includes a second main body portion 513 and a second extension portion 514. The positional relationship between the second main body portion 513 and the second extension portion 514 can be referred to the positional relationship between the first main body portion 413 and the first extension portion 414 in the first upper plastic 41 described above. The second upper plastic 51 also provides a second mounting hole 511 and a second mating groove 512. The positional relationship between the second mounting hole 511 and the second mating groove 512 in the second upper plastic 51 can also be referred to the relevant description of the first mounting hole 411 and the first mating groove 412 in the first upper plastic 41 described above, and will not be repeated here.

[0101] In some other embodiments, when the injection hole 202 is located between the explosion-proof hole 201 and the second assembly hole 204, that is, when the injection hole 202 is located close to the second assembly hole 204, the second upper plastic 51 may also include a protrusion 415. Figure 15 (Not shown in the image), the positional relationship of the protrusion 415 in the second upper plastic 51 can be referred to the relevant description of the positional relationship of the protrusion 415 in the first upper plastic 41, and will not be repeated here.

[0102] In this embodiment, the second main body 513 includes a second mating surface 501 and a second connecting surface 502 that are opposite to the cover 20. The positions of the second mating surface 501 and the second connecting surface 502 in the second main body 513, the positional relationship between the second mating surface 501 and the second connecting surface 502, and the positional relationship between the second mating surface 501 and the second connecting surface 502 and the second pole post 52, etc., can all be referred to the relevant descriptions of the first mating surface 401 and the first connecting surface 402 above, and will not be repeated here.

[0103] Please refer to the following: Figure 4 , Figure 14 and Figure 16 , Figure 16 yes Figure 14 The diagram shows the structure of the second pole 52 in the second pole unit 50 after being cut open at point II.

[0104] In this embodiment, the structure of the second pole post 52 is similar to that of the first pole post 42. The difference lies in that the second pole post 52 includes a second flange portion 521 and a second fixing portion 523. The second fixing portion 523 is fixedly connected to one side of the second flange portion 521 in the thickness direction. The peripheral side surface of the second flange portion 521 protrudes relative to the peripheral side surface of the second fixing portion 523. The second fixing portion 523 includes a second assembly portion 523a and a second mating portion 523b. The second mating portion 523b is connected to one side of the second assembly portion 523a, and the peripheral side surface of the second mating portion 523b is flush with the peripheral side surface of the second assembly portion 523a.

[0105] Specifically, the second flange portion 521 is installed within the second mating groove 512, and the second fixing portion 523 passes through the second mounting hole 511 of the second upper plastic 51, the second assembly hole 204 of the cover 20, and the second through hole 104 of the lower plastic 10. Specifically, the second assembly portion 523a of the second fixing portion 523 passes through the second mounting hole 511 and the second assembly hole 204, and the second mating portion 523b of the second fixing portion 523 passes through the second through hole 104. The second main body portion 513 of the second upper plastic 51 is located between the second flange portion 521 and the cover 20, and the second extension portion 514 is located between the peripheral side of the second fixing portion 523 of the second pole post 52 and the wall surface of the second assembly hole 204. This arrangement avoids short circuits in the end cap assembly 120 caused by direct contact between the second pole post 52 and the cover 20.

[0106] Please refer to the following: Figure 4 , Figure 14 and Figure 17 , Figure 17 yes Figure 14 The diagram shows the structure of the second welding ring 54 in the second pole unit 50 after being cut open along JJ.

[0107] In this embodiment, the structure of the second welding ring 54 is the same as that of the first welding ring 44. The second welding ring 54 is located on the side of the cover 20 opposite to the second upper plastic 51. Specifically, the second welding ring 54 is installed in the second through hole 104 of the lower plastic 10, abuts against the second protrusion 12, and is welded and fixed to the second pole post 52. Specifically, the second welding ring 54 includes a second welding ring body 541 and a second retaining ring 542, with the second retaining ring 542 fixedly connected to the second welding ring body 541. The second welding ring body 541 is provided with a second mating hole 543. The second mating hole 543 penetrates the second welding ring body 541 along its thickness direction. The second retaining ring 542 is located in the second mating hole 543 and is fixedly connected to the hole wall of the second mating hole 543. The thickness of the second retaining ring 542 is between 0.2 mm and 0.5 mm. The difference between the inner diameter d2 of the second retaining ring 542 and the diameter D2 of the second mating hole 543 is between 0.3 mm and 1 mm. That is, the width of the second retaining ring 542 is between 0.3 mm and 1 mm. With this setting, the second retaining ring 542 can be guaranteed to have a certain thickness and width to block the gap between the second pole post 52 and the second welding ring body 541.

[0108] Specifically, the second welding ring body 541 is sleeved on the second mating portion 523b of the second fixing portion 523 in the second pole post 52. That is, the second mating portion 523b passes through the second mating hole 543. Along the thickness direction of the end cap assembly 120, the second retaining ring 542 is located on the side of the second mating portion 523b opposite to the second mounting portion 523a, and covers the gap between the second mating portion 523b and the second welding ring body 541. When the second welding ring 54 is welded to the second pole post 52, the second retaining ring 542 melts and fills the gap between the second welding ring body 541 and the second mating portion 523b of the second pole post 52.

[0109] In this embodiment, by providing a second retaining ring 542 on the second welding ring 54 and making the second retaining ring 542 block the assembly gap between the second assembly part 523a and the second welding ring body 541, when the second welding ring 54 and the second electrode post 52 are laser welded, the second retaining ring 542 will be melted by the laser first and fill the assembly gap between the second mating part 523b and the second welding ring body 541. This can prevent the laser from entering the assembly gap between the second mating part 523b and the second welding ring body 541, avoid the welding explosion problem caused by the second upper plastic 51 being burned, and thus help reduce the welding defect rate between the second electrode post 52 and the second welding ring 54. Meanwhile, the peripheral side surface of the second assembly part 523a is flush with the peripheral side surface of the second mating part 523b, so that there is no step structure at the mating position of the second welding ring body 541 and the second pole post 52. This can avoid the interference fit between the second welding ring body 541 and the second pole post 52, thereby preventing the second welding ring 54 and the second pole post 52 from forming a false sealing state. This will prevent products with abnormal sealing state from being undetected when the energy storage device 100 performs short circuit and withstand voltage tests, and thus prevent unqualified products from flowing out, which helps to improve the production quality of the energy storage device 100.

[0110] In this embodiment, the second welding ring 54 is further provided with a second clearance notch 544. Specifically, the opening of the second clearance notch 544 is located on the surface of the second welding ring body 541 of the second welding ring 54 facing the cover 20. The second clearance notch 544 is recessed from the surface of the second welding ring body 541 of the second welding ring 54 facing the cover 20 in a direction away from the cover 20, and penetrates the peripheral side surface of the second welding ring body 541. The second clearance notch 544 is provided around the second mating hole 543 and is spaced apart from the second mating hole 543, and the second clearance notch 544 avoids the second protrusion 12 of the lower plastic 10. With this configuration, on the one hand, the second protrusion 12 can be spaced out in the thickness direction of the end cap assembly 120, preventing it from being broken due to its thinness during the pressing of the second welding ring 54 and the second electrode post 52. This prevents electrolyte inside the energy storage device 100 from seeping into the space between the first welding ring 44 and the cover body 20 through the gap between the second welding ring 54 and the second protrusion 12 of the lower plastic 10, improving the insulation performance between the second welding ring 54 and the cover body 20, avoiding short circuits inside the end cap assembly 120, and also improving the assembly reliability of the second welding ring 54 and the lower plastic 10, thereby enhancing the assembly reliability of the end cap assembly 120. On the other hand, it can also increase the area of ​​the pressing surface between the second welding ring 54 and the lower plastic 10, thereby extending the electrolyte penetration path and further improving the sealing performance of the end cap assembly 120.

[0111] Furthermore, the second clearance notch 544 includes a second sidewall 544a. The second sidewall 544a is disposed around the periphery of the second pole post 52. Specifically, the second sidewall 544a is disposed around the periphery of the second fixing portion 523 of the second pole post 52. In this embodiment, the second sidewall 544a is located between the surface of the second protrusion 22 of the cover 20 facing the second pole post 52 and the peripheral surface of the second pole post 52. Specifically, the second sidewall 544a is located between the surface of the second protrusion 22 facing the second fixing portion 523 and the peripheral surface of the second fixing portion 523. With this arrangement, the second sidewall 544a can be misaligned with the surface of the second protrusion 22 facing the second pole post 52.

[0112] Please refer to the following: Figure 4 , Figure 14 and Figure 18 , Figure 18 yes Figure 14 The diagram shows the structure of the second sealing ring 53 in the second pole unit 50 after being cut open along KK.

[0113] In this embodiment, the structure of the second sealing ring 53 is the same as that of the first sealing ring 43. The second sealing ring 53 is sleeved on the second assembly part 523a of the second pole post 52 and is sandwiched between the cover 20 and the lower plastic 10, and between the cover 20 and the second welding ring 54. The second sealing ring 53 not only ensures the assembly stability between the second welding ring 54 and the cover 20, and between the lower plastic 10 and the cover 20, but also prevents the second welding ring 54 from directly contacting the cover 20 for conduction, thus achieving insulation between the second welding ring 54 and the cover 20.

[0114] Specifically, the second sealing ring 53 includes a second sealing body 531, a second sealing flange 532, and a second tooth 533. The second sealing flange 532 and the second tooth 533 are both fixedly connected to the second sealing body 531 and are located on opposite sides of the second sealing body 531. Specifically, the second sealing body 531 is sleeved on the second assembly portion 523a of the second pole post 52 and is clamped between the bottom wall of the second assembly groove 207 of the cover 20 and the surface of the second welding ring body 541 of the second welding ring 54 facing the cover 20. The second sealing body 531 seals the gap between the bottom wall of the second assembly groove 207 and the surface of the second welding ring body 541 of the second welding ring 54 facing the cover 20.

[0115] The second sealing flange 532 is connected to the side of the second sealing body 531 opposite to the second mounting portion 523a of the second pole post 52, and is clamped between the second protrusion 22 of the cover 20 and the second protrusion 12 of the lower plastic 10, sealing the gap between the second protrusion 12 and the second protrusion 22. It is understood that by misaligning the second sidewall surface 544a of the second welding ring 54 with the surface of the second protrusion 22 facing the second pole post 52, the second sealing flange 532 can be provided with the maximum pressing area, thereby helping to improve the sealing performance between the cover 20 and the lower plastic 10.

[0116] In this embodiment, along the thickness direction of the end cap assembly 120, the thickness of the second sealing flange 532 is less than the thickness of the second sealing body 531, and the compression amount of the second sealing flange 532 is less than the compression amount of the second sealing body 531. In this embodiment, the ratio of the initial thickness of the second sealing flange 532 to the distance between the surface of the lower plastic 10 facing the second protrusion 22 and the surface of the second protrusion 22 facing the lower plastic 10 is 1.08≤a2≤2.22. The ratio of the initial thickness of the second sealing body 531 to the distance between the bottom wall of the second assembly groove 207 and the surface of the second welding ring 54 facing the cover 20 is 1.31≤b2≤1.92. Here, "initial thickness of the second sealing flange 532" refers to the thickness of the second sealing flange 532 before compression, and "initial thickness of the second sealing body 531" refers to the thickness of the second sealing body 531 before compression. With this setting, it can be ensured that the compression of the second sealing flange 532 is less than the compression of the second sealing body 531, thereby preventing the second sealing flange 532 from affecting the overall sealing performance of the end cap assembly 120.

[0117] It should be noted that in the actual production process, the dimensions and assembly tolerances of components such as the lower plastic 10 and the cover body 20 in the end cap assembly 120 need to be adjusted according to the product requirements in order to control the compression of the second sealing flange 532 and the second sealing body 531 of the second sealing ring 53.

[0118] Understandably, during the assembly of the end cap assembly 120, when the second welding ring 54 is welded to the second pole post 52, the second welding ring 54 will squeeze the lower plastic 10 and the second sealing ring 53. By clamping the second sealing flange 532 of the second sealing ring 53 between the second protrusion 22 of the cover body 20 and the second protrusion 12 of the lower plastic 10, the second sealing flange 532 is compressed and seals the gap between the second protrusion 22 and the second protrusion 12. This achieves a seal between the cover body 20 and the lower plastic 10, preventing the electrolyte inside the energy storage device 100 from seeping into the gap between the cover body 20 and the second welding ring 54 through the gap between the second protrusion 22 of the cover body 20 and the second protrusion 12 of the lower plastic 10. This avoids short circuit breakdown problems in the energy storage device 100 during short circuit and withstand voltage tests, prevents the energy storage device 100 from catching fire and exploding, and helps improve the safety and reliability of the energy storage device 100.

[0119] The second protruding tooth 533 is connected to the side of the second sealing body 531 facing the second mounting portion 523a of the second pole post 52, and abuts against the second mounting portion 523a of the second pole post 52, so that the circumferential surface of the second mounting portion 523a of the second pole post 52 is spaced apart from the second sealing body 531. For example, there are multiple second protruding teeth 533. The multiple second protruding teeth 533 are spaced apart from each other.

[0120] In this embodiment, by providing a second protruding tooth 533 on the side of the second sealing body 531 facing the second pole post 52 and making the second protruding tooth 533 abut against the second pole post 52, the second sealing flange 532 can be separated from the peripheral side of the second pole post 52 during the compression of the second sealing ring 53. This avoids a false sealing state that occurs when the second sealing body 531 of the second sealing ring 53 is compressed and adheres to the second pole post 52 or the second upper plastic 51. This can solve the problem that it is not easy to detect when there are abnormalities at the welding point or other sealing points of the end cap assembly 120, thereby reducing the outflow rate of defective products and improving the production quality of the energy storage device 100.

[0121] In this embodiment, the second sealing ring 53 further includes a second center surface 53a. The second center surface 53a is perpendicular to the thickness direction of the second sealing ring 53 and passes through the second sealing body 531, the second sealing flange 532, and the second tooth 533. Along the thickness direction of the second sealing ring 53, the second sealing ring 53 is mirror-symmetrical about the second center surface 53a. With this configuration, during the assembly of the end cap assembly 120, there is no need to consider the orientation of the second sealing ring 53, thereby helping to reduce the assembly difficulty of the second sealing ring 53 in the end cap assembly 120, which in turn helps to speed up the production pace of the end cap assembly 120 and improve production efficiency.

[0122] Furthermore, when the second sealing ring 53 is assembled with the lower plastic 10, the plurality of second guide blocks 14 of the lower plastic 10 are all located on the side of the second sealing flange 532 facing away from the second sealing body 531. With this arrangement, the assembly position of the second sealing ring 53 in the end cap assembly 120 can be limited, and the compression space of the second sealing ring 53 can be ensured without affecting it when the second sealing ring 53 is compressed.

[0123] Please refer to it again. Figure 3 and Figure 4 The end cap assembly 120 also includes a top patch 70. Exemplarily, the top patch 70 is a rectangular thin plate. The top patch 70 is mounted on the first surface 20a of the cap body 20, covering the injection hole 202 and blocking at least a portion of the protrusion 415. The top patch 70 can serve as insulation. Specifically, the top patch 70 is provided with a first clearance hole 701, a second clearance hole 702, and a third clearance hole 703. The first clearance hole 701, the second clearance hole 702, and the third clearance hole 703 all penetrate the top patch 70 along its thickness direction and are spaced apart from each other. Along the length direction of the top patch 70, the first clearance hole 701 and the second clearance hole 702 are located on opposite sides of the third clearance hole 703. The first clearance hole 701 avoids the first upper plastic 41, and the second clearance hole 702 avoids the second upper plastic 51. When thermal runaway occurs in the energy storage device 100, the third clearance hole 703 can avoid the explosion-proof valve 30.

[0124] It is understood that by providing the top patch 70 and using it to cover at least a portion of the protrusion 415 of the first upper plastic 41, electrolyte crystallization can be prevented from precipitating out from the assembly gap between the first upper plastic 41 and the cover 20, thereby helping to improve the appearance yield of the energy storage device 100 and ensuring a cleaner appearance. In some other embodiments, when the second upper plastic 51 is provided with the aforementioned protrusion 415, the protrusion 415 of the second upper plastic 51 is installed in the mounting groove 205 surrounding the second mounting hole 204. In this case, the top patch 70 can also cover the assembly gap between the protrusion 415 of the second upper plastic 51 and the cover 20, preventing electrolyte crystallization from precipitating out from the assembly gap between the second upper plastic 51 and the cover 20, thereby also helping to improve the appearance yield of the energy storage device 100 and ensuring a cleaner appearance.

[0125] This application also provides an electrical device, which includes the aforementioned energy storage device 100, and the energy storage device 100 supplies power to the electrical device. The electrical device can be a new energy vehicle, a power storage station, a server, or other equipment that requires electricity.

[0126] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Where there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An end cap assembly for an energy storage device, characterized in that, The device includes a lower plastic component, a cover, an electrode post, a sealing ring, and a welding ring. The lower plastic component has a through hole that penetrates the lower plastic component along its thickness direction. The lower plastic component also has a protrusion connected to the wall of the through hole and positioned around its center. The cover is mounted on one side of the lower plastic component along its thickness direction. The cover has an assembly hole and an assembly groove. The assembly hole penetrates the cover along its thickness direction and communicates with the through hole. The opening of the assembly groove is located on the surface of the cover facing the lower plastic component. The assembly groove surrounds the assembly hole and communicates with it. The cover also has a protrusion... The bulge and the protrusion are spaced apart and opposite to each other along the thickness direction of the end cap assembly, and the pole passes through the through hole and the assembly hole. The welding ring is located on the side of the lower plastic away from the cover body and is sleeved on the pole. The sealing ring is sleeved on the pole. The sealing ring includes a sealing body and a sealing flange. The sealing body is sleeved on the pole and is held between the bottom wall of the assembly groove and the surface of the welding ring facing the cover body. The sealing flange is connected to the side of the sealing body away from the pole and is arranged around the periphery of the sealing body and is held between the bulge and the protrusion.

2. The end cap assembly according to claim 1, characterized in that, Along the thickness direction of the end cap assembly, the thickness of the sealing flange is less than the thickness of the sealing body, and the compression of the sealing flange is less than the compression of the sealing body.

3. The end cap assembly according to claim 2, characterized in that, The ratio α of the initial thickness of the sealing flange to the distance between the surface of the lower plastic facing the protrusion and the surface of the protrusion facing the lower plastic is 1.08 ≤ a ≤ 2.22; The ratio b of the initial thickness of the sealing body to the distance between the bottom wall of the assembly groove and the surface of the welding ring facing the cover is 1.31≤b≤1.

92.

4. The end cap assembly according to claim 1, characterized in that, Both the bump and the convex hull are annular; The sealing ring has a central surface perpendicular to the thickness direction of the sealing ring, and the sealing ring is mirror-symmetrical about the central surface along the thickness direction of the sealing ring.

5. The end cap assembly according to claim 1, characterized in that, The sealing ring also includes protruding teeth, which are connected to the side of the sealing body facing the pole and abut against the pole.

6. The end cap assembly according to claim 5, characterized in that, The protruding teeth are multiple, and the multiple protruding teeth are arranged at intervals around the pole post.

7. The end cap assembly according to claim 1, characterized in that, The welding ring is provided with a clearance notch. The opening of the clearance notch is located on the surface of the welding ring facing the cover, and the clearance notch penetrates the circumferential side of the welding ring, thus avoiding the protrusion.

8. The end cap assembly according to claim 7, characterized in that, The clearance notch includes a sidewall surface that surrounds the periphery of the pole post and is located between the surface of the convex bulge facing the pole post and the periphery of the pole post.

9. The end cap assembly according to claim 1, characterized in that, The lower plastic includes a first surface facing the cover body. The first surface is provided with a guide block. The guide block is arranged around the periphery of the through hole and installed in the assembly groove. It is located on the side of the sealing flange away from the sealing body. The guide block includes a guide surface located on the side of the guide block away from the through hole. The guide surface includes a first end close to the first surface and a second end opposite to the first end. The distance between the guide surface and the first surface gradually increases from the first end to the second end.

10. The end cap assembly according to claim 1, characterized in that, The cover is provided with a mounting groove, the opening of the mounting groove is located on the surface of the cover away from the lower plastic, the mounting groove is arranged around the assembly hole and is spaced apart from the assembly hole; The end cap assembly also includes an upper plastic part, which includes a main body and a protrusion. The main body is sleeved on the pole post and connected between the pole post and the cap body. The protrusion is connected to the side of the main body facing the cap body and fills the mounting groove.

11. The end cap assembly according to claim 10, characterized in that, The peripheral side of the protrusion protrudes relative to the peripheral side of the main body.

12. The end cap assembly according to claim 11, characterized in that, The end cap assembly also includes a top patch, which is mounted on the side of the cap body opposite to the lower plastic and covers at least part of the protrusion.

13. The end cap assembly according to any one of claims 10 to 12, characterized in that, The pole includes a flange portion, which is located on the side of the main body opposite to the cover. The main body includes a connecting surface facing away from the cover. The connecting surface is disposed around the peripheral side of the flange. The connecting surface includes a first side close to the flange and a second side opposite to the first side. In the direction from the first side to the second side, the distance between the connecting surface and the surface of the cover facing the main body gradually decreases.

14. The end cap assembly according to claim 13, characterized in that, The connecting surface is an arc surface.

15. The end cap assembly according to claim 13, characterized in that, The first side is spaced apart from the peripheral side of the flange.

16. An energy storage device, characterized in that, It includes a housing and an end cap assembly as described in any one of claims 1 to 15, the end cap assembly being mounted on the housing and closing an opening in the housing.

17. An electrical appliance, characterized in that, It includes the energy storage device as described in claim 16, wherein the energy storage device supplies power to the electrical equipment.

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