End cover assembly, energy storage device and electric equipment

Abstract

According to the end cover assembly, the energy storage device and the electric equipment provided by the invention, laser can be prevented from easily entering the assembly gap between the pole and the welding ring, welding burst points caused by burning of the upper plastic and the sealing ring are avoided, and the welding yield of welding between the pole and the welding ring is improved. The end cover assembly comprises a cover body, a welding ring, a pole, upper plastic and a sealing ring, the cover body comprises a first surface and a second surface which are arranged oppositely, the cover body is provided with an assembly hole, and the assembly hole penetrates through the first surface and the second surface; the pole penetrates through the assembly hole, the welding ring is located on the side, away from the first surface, of the second surface and comprises a welding ring body and a baffle ring, the pole is sleeved with the welding ring body, and the baffle ring is connected to the side, facing the pole, of the welding ring and shields a gap between the welding ring body and the pole; the upper plastic penetrates through the assembly hole and is connected between the pole and the cover body; and the sealing ring is sleeved on the pole and is clamped between the cover body and the welding ring main body.

Description

Technical Field

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

[0002] Rechargeable battery, also known as rechargeable battery or storage battery, refers to a battery that can be recharged to activate the active material and continue to be used after the battery is discharged. The recyclable nature of secondary batteries has made them gradually become the main power source for electrical equipment. As the demand for secondary batteries gradually increases, people's requirements for the energy density and reliability of secondary batteries are also getting higher and higher. In the end cap assembly of existing secondary batteries, when the pole and the welding ring are laser welded, the laser can easily penetrate the assembly gap between the pole and the welding ring, causing the upper plastic and the sealing ring to be burned, resulting in welding explosion points, and reducing the welding yield between the pole and the welding ring. Utility Model Content

[0003] The present application provides an end cover assembly, an energy storage device and an electrical equipment, which can prevent the laser from easily entering the assembly gap between the pole and the welding ring, avoid welding explosion points caused by burning of the upper plastic and the sealing ring, and improve the welding yield between the pole and the welding ring.

[0004] In the first aspect, the present application provides an end cap assembly for use in an energy storage device. The end cap assembly includes a cover body, a welding ring, a pole, an upper plastic and a sealing ring, the cover body includes a first surface and a second surface, along the thickness direction of the cover body, the first surface and the second surface are arranged opposite to each other, the cover body is provided with an assembly hole, and the assembly hole passes through the first surface and the second surface; the pole is passed through the assembly hole, the welding ring is located on the side of the second surface away from the first surface, the welding ring includes a welding ring body and a retaining ring, the welding ring body is sleeved on the pole, the retaining ring is connected to the side of the welding ring facing the pole, and blocks the gap between the welding ring body and the pole; the upper plastic is passed through the assembly hole and connected between the pole and the cover body; the sealing ring is sleeved on the pole and clamped between the cover body and the welding ring body.

[0005] When the welding ring is welded to the pole, the retaining ring melts and fills the gap between the welding ring body and the pole.

[0006] Among them, the welding ring body is provided with a matching hole, the matching hole penetrates the welding ring body along the thickness direction of the welding ring body and is connected with the assembly hole; the pole includes an assembly part and a matching part, the assembly part is penetrated through the assembly hole, the matching part is connected to one side of the assembly part and is penetrated through the matching hole, and the peripheral side surface of the matching part is flush with the peripheral side surface of the assembly part; the retaining ring is connected to the hole wall surface of the matching hole, and is arranged around the center of the matching hole, and blocks the gap between the peripheral side surface of the matching part and the hole wall surface of the matching hole.

[0007] Wherein, the width of the retaining ring is between 0.3 mm and 1 mm.

[0008] Wherein, the thickness of the retaining ring is between 0.2 mm and 0.5 mm.

[0009] Wherein, the end cover assembly also includes a lower plastic, the lower plastic is installed on the second surface, the lower plastic is provided with a through hole, the through hole penetrates the lower plastic along the thickness direction of the lower plastic, and is connected with the assembly hole; the sealing ring includes a sealing body and a sealing flange, the sealing body is sleeved on the pole and clamped between the cover body and the welding ring body, the sealing flange is connected to the side of the sealing body away from the pole, and is arranged around the circumference of the sealing body, and is clamped between the cover body and the lower plastic.

[0010] The lower plastic is further provided with a convex block, which is connected to the hole wall surface of the through hole and is arranged around the center of the through hole; the cover body is further provided with an assembly groove, the opening of the assembly groove is located on the second surface, the assembly groove is arranged around the assembly hole and is connected to the assembly hole, and a convex hump is provided on the side of the cover body facing the lower plastic, the convex hump is arranged in the assembly groove and connected to the groove bottom wall surface of the assembly groove, and along the thickness direction of the end cover assembly, the convex hump and the convex block are spaced and arranged oppositely; the sealing body is clamped between the groove bottom wall surface of the assembly groove and the surface of the welding ring body facing the cover body, and the sealing flange is clamped between the convex hump and the convex block.

[0011] The welding ring body is provided with an avoidance notch, the opening of the avoidance notch is located on the surface of the welding ring body facing the cover body, and the avoidance notch penetrates the peripheral side surface of the welding ring body, and the avoidance notch avoids the protrusion.

[0012] Second aspect, the present application further provides an end cap assembly for an energy storage device. The end cap assembly includes a cover body, a welding ring, a pole column, a first welding part, an upper plastic, and a sealing ring. The cover body includes a first surface and a second surface. Along the thickness direction of the cover body, the first surface and the second surface are arranged opposite to each other. The cover body is provided with an assembly hole that penetrates the first surface and the second surface. The pole column is inserted through the assembly hole. The welding ring is located on the side of the second surface facing away from the first surface and is sleeved on the pole column. The first welding part is located on the side of the welding ring facing the pole column, is connected to the pole column, and is arranged offset from the gap between the welding ring and the pole column. The upper plastic is inserted through the assembly hole and is connected between the pole column and the cover body. The sealing ring is sleeved on the pole column and is clamped between the cover body and the welding ring.

[0013] Wherein, the end cap assembly further includes a second welding part, which is connected between the welding ring and the first welding part and fills the gap between the welding ring and the pole column.

[0014] Third aspect, the present application further provides an energy storage device, including a housing and the end cap assembly as described in any one of the above. The end cap assembly is installed on the housing and closes the opening of the housing.

[0015] Fourth aspect, the present application further provides an electrical device, including the energy storage device as described above, and the energy storage device supplies power to the electrical device.

[0016] In the end cap assembly provided by the present application, by providing a retaining ring on the welding ring and making the retaining ring block the assembly gap between the pole column and the main body of the welding ring, laser can be blocked from entering the assembly gap between the pole column and the welding main body, avoiding the problem of welding explosion points caused by burning of the upper plastic and the sealing ring, and thus helping to improve the welding yield between the pole column and the welding ring. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the embodiments of the present application will be described below.

[0018] Figure 1 is a schematic structural diagram of an energy storage device provided by an embodiment of the present application;

[0019] Figure 2 is Figure 1 a schematic structural diagram of the end cap assembly in the energy storage device shown;

[0020] Figure 3 is Figure 2 a schematic exploded structural diagram of the end cap assembly shown;

[0021] Figure 4 isFigure 2 Schematic cross-sectional structure diagram of the shown end cap assembly after being cut along A-A;

[0022] Figure 5 Is Figure 3 Schematic structure diagram of the lower plastic in the shown end cap assembly;

[0023] Figure 6 Is Figure 5 Schematic structure diagram of the shown lower plastic after being cut along B-B;

[0024] Figure 7 Is Figure 3 Schematic structure diagram of the cover body and explosion-proof valve in the shown end cap assembly;

[0025] Figure 8 Is Figure 7 Schematic cross-sectional structure diagram of the shown cover body after being cut along C-C;

[0026] Figure 9 Is Figure 3 Schematic exploded structure diagram of the first pole column unit in the shown end cap assembly;

[0027] Figure 10 Is Figure 9 Schematic cross-sectional structure diagram of the first upper plastic in the shown first pole column unit after being cut along D-D;

[0028] Figure 11 Is Figure 9 Schematic cross-sectional structure diagram of the first pole column in the shown first pole column unit after being cut along E-E;

[0029] Figure 12 Is Figure 9 Schematic cross-sectional structure diagram of the first welding ring in the shown first pole column unit after being cut along F-F;

[0030] Figure 13 Is Figure 9 Schematic cross-sectional structure diagram of the first sealing ring in the shown first pole column unit after being cut along G-G;

[0031] Figure 14 Is Figure 3 Schematic exploded structure diagram of the second pole column unit in the shown end cap assembly;

[0032] Figure 15 Is Figure 14 Schematic structure diagram of the second upper plastic in the shown second pole column unit after being cut along H-H;

[0033] Figure 16 Is Figure 14 Schematic structure diagram of the second pole column in the shown second pole column unit after being cut along I-I;

[0034] Figure 17 is Figure 14 The schematic structural diagram after the second welding ring in the second pole column unit shown is cut along J-J;

[0035] Figure 18 is Figure 14 The schematic structural diagram after the second sealing ring in the second pole column unit shown is cut along K-K;

[0036] Figure 19 is Figure 4 The schematic structural diagram after the end cover assembly shown is welded.

[0037] The names corresponding to the reference numerals in the figure are as follows:

[0038] Energy storage device 100, housing 110, end cap assembly 120, lower plastic 10, cover body 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 hole 102, first through hole 103, second through hole 104, first bump 11, second bump 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, liquid injection hole 202, first assembly hole 203, second assembly hole 204, installation groove 205, first assembly groove 206, second assembly groove 207, first convex hull 21, second convex hull 22, protection sheet 60, first upper plastic 41, first pole 42, first sealing ring 43, first welding ring 44, first installation hole 411, first fitting groove 412, first main body 413, first extension 414, protruding part 415, first fitting surface 401, first connection surface 402, first side 402a, second side 402b, first flange part 421, first installation part 422, first fixing part 423, first assembly part 423a, first fitting part 423b, first welding ring main body 441, first retaining ring 442, first fitting hole 443, first avoidance notch 444, first sealing main body 431, first sealing flange 432, first convex tooth 433, first central plane 43a, second upper plastic 51, second pole 52, second sealing ring 53, second welding ring 54, second installation hole 511, second fitting groove 512, second main body 513, second extension 514, second fitting surface 501, second connection surface 502, second flange part 521, second fixing part 523, second assembly part 523a, second fitting part 523b, second welding ring main body 541, second retaining ring 542, second fitting hole 543, second avoidance notch 544, second sealing main body 531, second sealing flange 532, second convex tooth 533, second central plane 53a, top sticker 70, first avoidance hole 701, second avoidance hole 702, third avoidance hole 703, first welding part 45, second welding part 46, third welding part 55, fourth welding part 56. Detailed implementation mode

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application.

[0040] Please refer to Figure 1 , Figure 1 , which is a schematic structural diagram of the energy storage device 100 provided by the embodiment of the present application. Among them, for the convenience 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, the height direction of the energy storage device 100 is defined as the Z-axis direction, and the X-axis direction, the Y-axis direction and the Z-axis direction are perpendicular to each other in pairs.

[0041] The energy storage device 100 includes a housing 110, a wound core (not shown in the figure), and an end cap assembly 120. The housing 110 has an opening (not shown in the figure) and a receiving cavity (not shown in the figure), and the opening communicates with the receiving cavity. The wound core is received in the receiving cavity. The receiving cavity is also used to receive an electrolyte, and the wound core is immersed in the electrolyte. 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 square battery. In some other embodiments, the energy storage device 100 may also be a cylindrical battery or other batteries.

[0042] Please refer to Figures 2 to 4 , Figure 2 is Figure 1 a schematic structural view of the end cap assembly 120 in the energy storage device 100 shown in Figure 3 is Figure 2 a schematic exploded structural view of the end cap assembly 120 shown in Figure 4 is Figure 2 a schematic cross-sectional structural view of the end cap assembly 120 shown in after being cut along the A-A line. Herein, "being cut along the A-A line" means being cut along the plane where the A-A line is located, and similar descriptions hereinafter can be understood in the same way.

[0043] 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 mounted on one side in the thickness direction of the cover body 20. The explosion-proof valve 30, the first pole unit 40, and the second pole unit 50 are all mounted on the cover body 20. Among them, along the length direction of the energy storage device 100, the first pole unit 40 and the second pole unit 50 are respectively located on opposite sides of the explosion-proof valve 30.

[0044] Please refer to Figure 4 , Figure 5 and Figure 6 , Figure 5 is Figure 3 a schematic structural view of the lower plastic 10 in the end cap assembly 120 shown in Figure 6 is Figure 5 a schematic structural view of the lower plastic 10 shown in after being cut along the B-B line.

[0045] The lower plastic 10 includes a first surface 10a and a second surface 10b, and the first surface 10a and the second surface 10b are arranged opposite to each other in the thickness direction of the lower plastic 10. Among them, 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 further includes an explosion-proof fence 101, and the explosion-proof fence 101 penetrates through the first surface 10a and the second surface 10b of the lower plastic 10. Specifically, the explosion-proof fence 101 is located in the middle of the lower plastic 10.

[0046] In this embodiment, the lower plastic member 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 through the first surface 10a and the second surface 10b of the lower plastic member 10 along the thickness direction of the lower plastic member 10 (the Z-axis direction shown in the figure), and are spaced apart from each other. Specifically, along the length direction of the energy storage device 100 (the X-axis direction shown in the figure), the liquid inlet hole 102 is located in the middle of the lower plastic member 10, on one side of the explosion-proof fence 101, and is spaced apart from the explosion-proof fence 101.

[0047] Along the length direction of the energy storage device 100 (the X-axis direction shown in the figure), both the first through hole 103 and the second through hole 104 are located at the edge of the lower plastic member 10, and are spaced apart from both 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.

[0048] In this embodiment, the lower plastic member 10 is further provided with a first convex block 11 and a second convex block 12. Among them, the first convex block 11 is fixedly connected to the hole wall of the first through hole 103. The second convex block 12 is fixedly connected to the hole wall of the second through hole 104. Along the length direction of the lower plastic member 10 (the X-axis direction shown in the figure), the second convex block 12 is spaced apart from the first convex block 11. Exemplarily, both the first convex block 11 and the second convex block 12 are annular.

[0049] In addition, the lower plastic member 10 is further provided with a first guiding block 13 and a second guiding block 14. Specifically, the first surface 10a is provided with the first guiding block 13 and the second guiding block 14. The first guiding block 13 is disposed around the circumferential side of the first through hole 103. Exemplarily, there are multiple first guiding blocks 13. The multiple first guiding blocks 13 are spaced apart around the first convex block 11. Each first guiding block 13 includes a first guiding surface 131. The first guiding surface 131 is located on the side of the first guiding block 13 away from the first through hole 103. Specifically, the first guiding surface 131 includes a first end 131a close to the first surface 10a and a second end 131b opposite to the first end 131a. In the direction from the first end 131a to the second end 131b, the distance between the first guiding surface 131 and the first surface 10a of the lower plastic member 10 gradually increases.

[0050] The second guiding block 14 is fixedly connected to the side of the second convex block 12 facing away from the second through hole 104. In this embodiment, the structure of the second guiding block 14 is the same as that of the above-mentioned first guiding block 13. Exemplarily, there may be multiple second guiding blocks 14. The multiple second guiding blocks 14 are arranged at intervals around the circumferential side of the second convex block 12. Each second guiding block 14 includes a second guiding surface 141. The structure of the second guiding surface 141 and the positional relationship of the second guiding surface 141 in the second guiding block 14 may refer to the relevant descriptions of the structure of the first guiding surface 131 and the positional relationship of the first guiding surface 131 in the first guiding block 13, which will not be elaborated here.

[0051] Please refer to Figure 4 、 Figure 7 and Figure 8 , Figure 7 is Figure 3 a schematic structural diagram of the cover body 20 and the explosion-proof valve 30 in the end cover assembly 120 shown in Figure 8 is Figure 7 a schematic cross-sectional structural diagram of the cover body 20 shown in

[0052] The cover body 20 includes a first surface 20a and a second surface 20b. Along the thickness direction of the cover body 20 (the illustrated Z-axis direction), the first surface 20a and the second surface 20b are arranged opposite to each other. Among them, the first surface 20a is the side of the cover body 20 facing away from the lower plastic 10, and the second surface 20b is the side of the cover body 20 facing the lower plastic 10.

[0053] The cover body 20 is further 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 through the first surface 20a and the second surface 20b of the cover body 20 along the thickness direction of the cover body 20 (the illustrated Z-axis direction), and are arranged at intervals from each other.

[0054] Specifically, both the explosion-proof hole 201 and the liquid injection hole 202 are located in the middle of the cover body 20. The explosion-proof hole 201 can communicate with the inside of the energy storage device 100 through the explosion-proof fence 101. Along the length direction of the cover body 20, the liquid injection hole 202 is located on one side of the explosion-proof hole 201. The liquid injection hole 202 communicates with the liquid inlet hole 102 of the lower plastic 10. The electrolyte can be injected into the accommodation cavity of the housing 110 (as shown in Figure 1 ) in sequence through the liquid injection hole 202 of the cover body 20 and the liquid inlet hole 102 of the lower plastic 10, so as to realize the perfusion of the electrolyte of the energy storage device 100.

[0055] Along the length direction of the energy storage device 100 (the X-axis direction shown in the figure), both the first assembly hole 203 and the second assembly hole 204 are located at the edge of the cover body 20, and are respectively located on the opposite sides of the explosion-proof hole 201 and the liquid injection hole 202. Specifically, the first assembly hole 203 is located on the side of the liquid injection hole 202 away from the explosion-proof hole 201. The second assembly hole 204 is located on the side of the explosion-proof hole 201 away from the liquid injection hole 202. Among them, the first assembly hole 203 communicates with the first through hole 103 of the lower plastic 10 to facilitate the installation of the first pole unit 40. The second assembly hole 204 communicates with the second through hole 104 of the lower plastic 10 to facilitate the installation of the second pole unit 50.

[0056] The opening of the installation groove 205 is located on the first surface 20a of the cover body 20. The installation groove 205 is recessed from the first surface 20a towards the second surface 20b. The installation groove 205 is arranged around the circumference of the first assembly hole 203 and is spaced from the first assembly hole 203. In some other embodiments, when the liquid injection hole 202 is provided between the explosion-proof hole 201 and the second assembly hole 204, that is, when the second assembly hole 204 is arranged close to the liquid injection hole 202, the installation groove 205 can also be arranged around the circumference of the second assembly hole 204 and is spaced from the second assembly hole 204.

[0057] In this embodiment, the openings of both the first assembly groove 206 and the second assembly groove 207 are located on the second surface 20b of the cover body 20. Among them, the first assembly groove 206 is recessed from the second surface 20b towards the first surface 20a and penetrates the hole wall surface of the first assembly hole 203. The first assembly groove 206 is arranged around the first assembly hole 203 and communicates with the first assembly hole 203. The second assembly groove 207 is recessed from the second surface 20b towards the first surface 20a and penetrates the hole wall surface of the second assembly hole 204. The second assembly groove 207 is arranged around the second assembly hole 204 and communicates with the second assembly hole 204. Along the length direction of the cover plate, the second assembly groove 207 is spaced from the first assembly groove 206.

[0058] During the assembly process of the cover body 20 and the lower plastic part 10, since the first guiding surface 131 of the first guiding block 13 and the second guiding surface 141 of the second guiding block 14 in the lower plastic part 10 are both inclined, the first guiding surface 131 and the second guiding surface 141 can play a role in guiding and positioning the installation of the lower plastic part 10. Among them, the first guiding block 13 is installed in the first assembly groove 206 so that the first through hole 103 is aligned and communicated with the first assembly hole 203. The second guiding block 14 is installed in the second assembly groove 207 so that the second through hole 104 of the lower plastic part 10 is aligned and communicated with the second assembly hole 204. With this setting, it can prevent the lower plastic part 10 from shifting during the assembly with the cover body 20, enabling the lower plastic part 10 and the cover body 20 to be accurately positioned, so as to ensure that the first pole unit 40 and the second pole unit 50 can be accurately assembled with the cover body 20 and the lower plastic part 10, and avoid the problem of poor assembly of the end cover assembly 120.

[0059] In addition, a first convex bump 21 and a second convex bump 22 are further provided on the side of the cover body 20 facing the lower plastic part 10. Among them, the first convex bump 21 is arranged in the first assembly groove 206 and surrounds the circumferential side of the first assembly hole 203. Exemplarily, the first convex bump 21 is generally annular. In the thickness direction of the end cover assembly 120, the first convex bump 21 and the first convex block 11 of the lower plastic part 10 are arranged at intervals and opposite to each other. The second convex bump 22 is arranged in the second assembly groove 207 and surrounds the circumferential side of the second assembly hole 204. Exemplarily, the second convex bump 22 is generally annular. In the thickness direction of the end cover assembly 120, the second convex bump 22 and the first convex block 11 of the lower plastic part 10 are arranged at intervals and opposite to each other.

[0060] It can be understood that by providing the first convex bump 21 and the second convex bump 22 on the side of the cover body 20 facing the lower plastic part 10, the thickness of the cover body 20 can be increased, thereby enhancing the structural strength of the cover body 20, and further helping to improve the use reliability of the cover body 20 and extend the service life of the cover body 20.

[0061] Please continue to refer to 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. Exemplarily, the explosion-proof valve 30 can be fixedly connected to the hole wall of the explosion-proof hole 201 by welding to be installed in the explosion-proof hole 201. It can be understood that since the explosion-proof hole 201 communicates the inside and the outside of the energy storage device 100, when the air pressure inside the energy storage device 100 is too high, the explosion-proof valve 30 will burst under the action of the air pressure, and the gas inside the energy storage device 100 can pass through the explosion-proof fence 101 of the lower plastic part 10 and the explosion-proof hole 201 in sequence and be discharged to the outside of the energy storage device 100 in time, avoiding the explosion of the energy storage device 100 and improving the use reliability of the energy storage device 100.

[0062] In this embodiment, the end cap assembly 120 may further include a protective sheet 60. The protective sheet 60 is installed on the cover plate and covers the explosion-proof hole 201. The protective sheet 60 is used to protect the explosion-proof valve 30, preventing the external environment and external forces from damaging the explosion-proof valve 30, thereby preventing the explosion-proof valve 30 from being accidentally touched and ensuring good reliability in the use of the energy storage device 100.

[0063] Please refer to Figure 4 , Figure 9 and Figure 10 , Figure 9 which is Figure 3 an exploded structural schematic diagram of the first pole unit 40 in the end cap assembly 120 shown in Figure 10 and Figure 9 is a cross-sectional structural schematic diagram of the first upper plastic 41 in the first pole unit 40 shown in

[0064] 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. The first upper plastic 41, the first sealing ring 43 and the first welding ring 44 are all sleeved on the first pole 42. Among them, the first upper plastic 41 is installed on the cover body 20 and is located between the cover body 20 and the first pole 42. Specifically, the first upper plastic 41 is provided with a first mounting hole 411 and a first mating groove 412. The first mounting hole 411 penetrates the first upper plastic 41 in the thickness direction of the first upper plastic 41 and is coaxial and communicated with the first fitting hole 203 of the cover body 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 body 20. The first mating groove 412 is recessed from the surface of the first upper plastic 41 facing away from the cover body 20 towards the cover body 20, penetrates the hole wall of the first mounting hole 411, and is communicated with the first mounting hole 411.

[0065] The first upper plastic 41 further includes a first main body portion 413, a first extension portion 414 and a protruding portion 415. The first extension portion 414 and the protruding portion 415 are both fixedly connected to the first main body portion 413. Among them, the first main body portion 413 is sleeved on the first pole 42 and is located between the first pole 42 and the cover body 20. The first main body portion 413 is provided with the first mating groove 412 and the first mounting hole 411. Among them, the opening of the first mating groove 412 is located on the surface of the first main body portion 413 facing away from the cover body 20.

[0066] The first main body portion 413 further includes a first mating surface 401 facing away from the cover body 20 and a first connecting surface 402. Among them, the opening of the first mating groove 412 is located on the first mating surface 401. Exemplarily, the first mating surface 401 is a flat surface to facilitate the mating and abutting of the first mating surface 401 with the first pole 42. The first connecting surface 402 is fixedly connected to the first mating surface 401 and is disposed around the circumferential side of the first mating surface 401. Exemplarily, the first connecting surface 402 is an arc surface. The first connecting surface 402 includes a first side 402a close to the first pole 42 and a second side 402b opposite to the first side 402a. In the direction from the first side 402a to the second side 402b, the distance between the first connecting surface 402 and the first surface 20a of the cover body 20 gradually decreases. That is to say, the first connecting surface 402 is an inclined arc surface.

[0067] It can be understood that after the liquid injection of the energy storage device 100 is completed, when the liquid injection nozzle is withdrawn from the liquid injection hole 202, the electrolyte is likely to splash onto the surface of the first upper plastic 41. By providing the first connecting surface 402 in an arc shape on the first upper plastic 41 and making the first connecting surface 402 inclined, the electrolyte is not easily retained on the first connecting surface 402, thereby avoiding the crystallization of the electrolyte on the surface of the first upper plastic 41, and further helping to keep the appearance of the end cover assembly 120 clean and reducing the appearance defect rate of the energy storage device 100. At the same time, the inclined arc-shaped first connecting surface 402 has a large area. Even if there is electrolyte residue on the first connecting surface 402, it is convenient to wipe, which also helps to prevent the crystallization of the electrolyte on the first connecting surface 402, and further helps to keep the appearance of the end cover assembly 120 clean and reduce the appearance defect rate of the energy storage device 100.

[0068] In this embodiment, both the first extension portion 414 and the protruding portion 415 are fixedly connected to the side of the first main body portion 413 facing the cover body 20. Among them, the first extension portion 414 is disposed around the circumferential side of the first mounting hole 411. Specifically, the first extension portion 414 is installed in the first fitting hole 203 of the cover body 20.

[0069] The protruding portions 415 are spaced around the circumferential side of the first extension portion 414, and the outer peripheral side surface of the protruding portion 415 protrudes relative to the outer peripheral side surface of the first main body portion 413. Specifically, the protruding portion 415 is installed in the installation groove 205 of the cover body 20. With this setting, the assembly gap between the first upper plastic 41 and the cover body 20 can be extended outwards, preventing the electrolyte remaining on the surface of the first upper plastic 41 from directly flowing into the assembly gap between the first upper plastic 41 and the cover body 20, thereby reducing the amount of electrolyte flowing into the assembly gap between the first upper plastic 41 and the cover body 20 to a certain extent and reducing the possibility of electrolyte crystallization in the assembly gap between the first upper plastic 41 and the cover body 20.

[0070] Please refer to Figure 9 and Figure 11 , Figure 11 which is Figure 9 a schematic cross-sectional structure diagram of the first pole column 42 in the first pole column unit 40 shown in FIG. E-E after being cut along E-E.

[0071] The first pole column 42 passes through the first mounting hole 411 of the first upper plastic 41, the first assembly hole 203 of the cover body 20, and the first through hole 103 of the lower plastic 10. Exemplarily, the first pole column 42 is a positive pole column and is made of aluminum metal material. In some other embodiments, the first pole column 42 may also be a negative pole column, and the embodiments of the present application do not strictly limit this.

[0072] In this embodiment, the first pole column 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 in the thickness direction of the first flange portion 421. Specifically, the first mounting portion 422 is fixedly connected to the first flange portion 421. Among them, the circumferential surface of the first flange portion 421 protrudes relative to the circumferential surface of the first mounting portion 422. The first fixing portion 423 is fixedly connected to the side of the first mounting portion 422 away from 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 circumferential surface of the first mating portion 423b is flush with the circumferential surface of the first assembly portion 423a.

[0073] Specifically, the first flange portion 421 of the first pole column 42 is located on the side of the first main body portion 413 of the first upper plastic 41 away from the cover body 20. Among them, the surface of the first flange portion 421 facing the first main body portion 413 abuts against the first mating surface 401. The circumferential surface of the first flange portion 421 is spaced from the first connection surface 402. That is, the first side 402a of the first connection surface 402 is spaced from the circumferential surface of the first flange portion 421. With this setting, the assembly gap between the first flange portion 421 of the first pole column 42 and the first main body portion 413 can be set in the horizontal direction, preventing the electrolyte from entering the assembly gap between the first main body portion 413 and the first flange portion 421, thereby reducing the possibility of subsequent crystallization of the electrolyte, and further helping to reduce the appearance defect rate of the energy storage device 100 and ensuring the appearance cleanliness of the energy storage device 100.

[0074] The first mounting portion 422 of the first pole column 42 is mounted within 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 fitting hole 203 of the cover body 20, and the first through hole 103 of the lower plastic 10. Specifically, the first fitting portion 423a of the first fixing portion 423 passes through the first mounting hole 411 and the first fitting hole 203, and the first mating portion 423b of the first fixing portion 423 passes through the first through hole 103. Among them, a part of the first main body portion 413 is located between the first flange portion 421 and the cover body 20, and another part of the first main body portion 413 is located between the first mounting portion 422 and the cover body 20. The first extension portion 414 of the first upper plastic 41 is located between the circumferential side surface of the first fixing portion 423 of the first pole column 42 and the hole wall surface of the first fitting hole 203. With this arrangement, it is possible to avoid the short - circuit problem caused by the direct contact between the first pole column 42 and the cover body 20 in the end - cover assembly 120.

[0075] Please refer to Figure 4 , Figure 9 and Figure 12 , Figure 12 which is Figure 9 the schematic cross - sectional structure diagram of the first welding ring 44 of the first pole - column unit 40 shown in FIG. F - F after being cut along the F - F.

[0076] In this embodiment, the first welding ring 44 is located on the side of the cover body 20 facing away from the first upper plastic 41. Specifically, the first welding ring 44 is mounted within the first through hole 103 of the lower plastic 10, abuts against the first bump 11, and is welded and fixed to the first pole column 42. Specifically, the first welding ring 44 includes a first welding - ring main body 441 and a first retaining ring 442, and the first retaining ring 442 is fixedly connected to the first welding - ring main body 441. Among them, the first welding - ring main body 441 is provided with a first fitting hole 443. The first fitting hole 443 penetrates through the first welding - ring main body 441 in the thickness direction of the first welding - ring main body 441. The first retaining ring 442 is located within the first fitting hole 443 and is fixedly connected to the hole wall surface of the first fitting hole 443.

[0077] Specifically, the first welding - ring main body 441 is sleeved on the first mating portion 423b of the first fixing portion 423 in the first pole column 42. That is to say, the first mating portion 423b passes through the first fitting hole 443. In the thickness direction of the end - cover assembly 120, the first retaining ring 442 is located on the side of the first mating portion 423b facing away from the first fitting portion 423a, and blocks the gap between the first mating portion 423b and the first welding - ring main body 441. When the first welding ring 44 is welded to the first pole column 42, the first retaining ring 442 melts and fills the gap between the first welding - ring main body 441 and the first mating portion 423b of the first pole column 42.

[0078] It can be understood that by providing the first retaining ring 442 on the first welding ring 44 and causing the first retaining ring 442 to block the assembly gap between the first mating portion 423b of the first pole 42 and the first welding ring body 441, when laser welding is performed between the first welding ring 44 and the first pole 42, the first retaining ring 442 will be first melted by the laser and fill the assembly gap between the first mating portion 423b and the first welding ring body 441, thereby blocking the laser from entering the assembly gap between the first mating portion 423b and the first welding ring body 441, avoiding the problem of welding explosion points caused by the burning of the first upper plastic 41, and thus helping to improve the welding yield between the first pole 42 and the first welding ring 44. At the same time, the circumferential side surface of the first assembly portion 423a of the first pole 42 is flush with the circumferential side surface of the first mating portion 423b, so that there is no stepped structure at the mating position between the first welding ring body 441 and the first pole 42, which can avoid the interference fit between the first welding ring body 441 and the first pole 42, thereby preventing the first welding ring 44 and the first pole 42 from forming a false seal state, avoiding products with abnormal seal states that cannot be detected during the short-circuit and withstand voltage tests of the energy storage device 100, and thus avoiding the outflow of unqualified products, which helps to improve the production quality of the energy storage device 100.

[0079] In this embodiment, the difference between the inner diameter d1 of the first retaining ring 442 and the aperture D1 of the first mating hole 443 is between 0.3 mm and 1 mm. That is, the width of the first retaining ring 442 is between 0.3 mm and 1 mm. With this setting, it can be ensured that the first retaining ring 442 has a certain width to block the gap between the first pole 42 and the first welding ring body 441, thereby preventing the laser from entering the assembly gap between the first pole 42 and the first welding ring body 441, and further avoiding the problem of welding explosion points caused by the burning of the first upper plastic 41 and the first sealing ring 43, and improving the welding yield between the first pole 42 and the first welding ring 44. The thickness of the first retaining ring 442 is between 0.2 mm and 0.5 mm to ensure that the first retaining ring 442 can fill the gap between the first pole 42 and the first welding ring body 441 after being melted by the laser, thereby preventing the laser from entering the assembly gap between the first pole 42 and the first welding ring body 441, and further avoiding the problem of welding explosion points caused by the burning of the first upper plastic 41 and the first sealing ring 43, and improving the welding yield between the first pole 42 and the first welding ring 44.

[0080] In addition, the first welding ring 44 is further provided with a first avoiding notch 444. Specifically, the first avoiding notch 444 is provided on the first welding ring body 441. The opening of the first avoiding notch 444 is located on the surface of the first welding ring body 441 facing the cover body 20. The first avoiding notch 444 is recessed from the surface of the first welding ring body 441 facing the cover body 20 in a direction away from the cover body 20 and penetrates through the circumferential side surface of the first welding ring body 441. The first avoiding notch 444 is arranged around the first fitting hole 443 and is spaced from the first fitting hole 443. The first avoiding notch 444 avoids the first convex block 11 of the lower plastic 10. With this setting, the assembly reliability of the first welding ring 44 and the lower plastic 10 can be improved, thereby contributing to the improvement of the assembly reliability of the end cover assembly 120.

[0081] Please refer to Figure 4 , Figure 9 and Figure 13 , Figure 13 which is Figure 9 the schematic cross-sectional structure diagram of the first sealing ring 43 in the first pole unit 40 shown after being cut along the G-G.

[0082] The first sealing ring 43 is sleeved on the first fixing portion 423 of the first pole 42 and is clamped between the cover body 20 and the lower plastic 10 and between the cover body 20 and the first welding ring 44. The first sealing ring 43 can not only ensure the assembly stability between the first welding ring 44 and the cover body 20, and between the lower plastic 10 and the cover body 20, but also avoid direct contact and conduction between the first welding ring 44 and the cover body 20, realizing insulation between the first welding ring 44 and the cover body 20.

[0083] Specifically, the first sealing ring 43 includes a first sealing main body 431, a first sealing flange 432 and a first convex tooth 433. The first sealing flange 432 and the first convex tooth 433 are both fixedly connected to the first sealing main body 431 and are respectively located on opposite sides of the first sealing main body 431. Specifically, the first sealing main body 431 is sleeved on the first fixing portion 423 of the first pole 42 and is clamped between the bottom wall of the first assembly groove 206 of the cover body 20 and the first welding ring body 441 of the first welding ring 44. The first sealing flange 432 is connected to one side of the first sealing main body 431 away from the first fixing portion 423 of the first pole 42 and is clamped between the first convex boss 21 of the cover body 20 and the first convex block 11 of the lower plastic 10, and seals the gap between the first convex block 11 and the first convex boss 21. In this embodiment, in the thickness direction of the end cover assembly 120, the thickness of the first sealing flange 432 is less than the thickness of the first sealing main body 431, and the compression amount of the first sealing flange 432 is less than the compression amount of the first sealing main body 431 to prevent the first sealing flange 432 from affecting the overall sealing performance of the end cover assembly 120.

[0084] It can be understood that during the assembly of the end cap assembly 120, when the first welding ring 44 is welded to the first pole 42, the first welding ring 44 will squeeze the lower plastic 10 and the first sealing ring 43. By clamping the first sealing flange 432 of the first sealing ring 43 between the first convex portion 21 of the cover body 20 and the first convex block 11 of the lower plastic 10, the first sealing flange 432 is compressed under extrusion and seals the gap between the first convex portion 21 and the first convex block 11, thereby realizing the 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 first convex portion 21 of the cover body 20 and the first convex block 11 of the lower plastic 10 and then into the space between the cover body 20 and the first welding ring 44. This can avoid the problem of short - circuit breakdown during the short - circuit and withstand - voltage tests of the energy storage device 100, prevent the energy storage device 100 from catching fire and exploding, and thus contribute to improving the safety and reliability of the energy storage device 100.

[0085] The first convex teeth 433 are connected to one side of the first sealing body 431 of the first sealing ring 43 facing the first assembly portion 423a of the first pole 42 and abut against the first assembly portion 423a of the first pole 42, so that the circumferential surface of the first assembly portion 423a of the first pole 42 is spaced from the first sealing body 431. Exemplarily, there are multiple first convex teeth 433. The multiple first convex teeth 433 are spaced from each other.

[0086] In this embodiment, by providing the first convex teeth 433 on one side of the first sealing body 431 of the first sealing ring 43 facing the first pole 42 and making the first convex teeth 433 abut against the first pole 42, the first sealing body 431 can be separated from the circumferential side surface of the first pole 42 during the compression of the first sealing ring 43, avoiding the false - sealing state where the first sealing body 431 of the first sealing ring 43 fits with the first pole 42 or the first upper plastic 41 after being compressed. This can solve the problem that it is not easy to detect when there is an abnormality at the welding or other sealing parts of the end cap assembly 120, thereby reducing the outflow rate of defective seals and improving the production quality of the energy storage device 100.

[0087] In this embodiment, the first sealing ring 43 further includes a first central plane 43a. The first central plane 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 convex teeth 433. Along the thickness direction of the first sealing ring 43, the first sealing ring 43 is mirror - symmetric about the first central plane 43a. With this setting, during the assembly of the end cap assembly 120, there is no need to consider the front - back placement position of the first sealing ring 43, which helps to reduce the assembly difficulty of the first sealing ring 43 in the end cap assembly 120, and thus is conducive to accelerating the production rhythm of the end cap assembly 120 and improving production efficiency.

[0088] In addition, when the first sealing ring 43 is assembled with the lower plastic 10, a plurality of first guiding blocks 13 of the lower plastic 10 are all located on the side of the first sealing flange 432 away from the first sealing body 431. With this arrangement, not only can the assembly position of the first sealing ring 43 in the end cover assembly 120 be limited, but also the compression space of the first sealing ring 43 can be ensured not to be affected when the first sealing ring 43 is compressed.

[0089] Please refer to Figure 4 、 Figure 14 and Figure 15 , Figure 14 is Figure 3 the exploded structural schematic diagram of the second pole unit 50 in the end cover assembly 120 shown in Figure 15 is Figure 14 the structural schematic diagram of the second upper plastic 51 in the second pole unit 50 after being cut along the H-H position shown in

[0090] The second pole unit 50 includes a second upper plastic 51, a second pole 52, a second sealing ring 53 and a second welding ring 54. Among them, for the structures of the components in the second pole unit 50, the assembly relationships between components, and the assembly relationships between components and the lower plastic 10 and the cover body 20, reference can be made to the relevant descriptions of the first pole unit 40 in the above text, which will not be elaborated here.

[0091] In this embodiment, the structure of the second upper plastic 51 is similar to that of the first upper plastic 41. The difference is 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 above-mentioned first upper plastic 41. The second upper plastic 51 is also provided with a second mounting hole 511 and a second mating groove 512. The positional relationship of the second mounting hole 511 and the second mating groove 512 in the second upper plastic 51 can also be referred to the relevant descriptions of the first mounting hole 411 and the first mating groove 412 in the first upper plastic 41, which will not be elaborated here.

[0092] In some other embodiments, when the liquid injection hole 202 is provided between the explosion-proof hole 201 and the second assembly hole 204, that is, when the liquid injection hole 202 is arranged close to the second assembly hole 204, the second upper plastic 51 can also include a protruding portion 415 ( Figure 15 not shown in

[0093] In this embodiment, the second main body portion 513 includes a second mating surface 501 facing away from the cover 20 and a second connecting surface 502. The positions of the second mating surface 501 and the second connecting surface 502 in the second main body portion 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 column 52, etc., can all refer to the relevant descriptions of the first mating surface 401 and the first connecting surface 402 in the above text, and will not be elaborated here.

[0094] Please refer to Figure 4 , Figure 14 and Figure 16 , Figure 16 is Figure 14 the schematic cross-sectional view of the second pole column 52 in the second pole column unit 50 shown in

[0095] In this embodiment, the structure of the second pole column 52 is similar to that of the first pole column 42. The difference is that the second pole column 52 includes a second flange portion 521 and a second fixing portion 523. The second fixing portion 523 is fixedly connected to one side in the thickness direction of the second flange portion 521. Among them, the circumferential surface of the second flange portion 521 protrudes relative to the circumferential surface of the second fixing portion 523. The second fixing portion 523 includes a second assembling portion 523a and a second mating portion 523b. The second mating portion 523b is connected to one side of the second assembling portion 523a, and the circumferential surface of the second mating portion 523b is flush with the circumferential surface of the second assembling portion 523a.

[0096] Specifically, the second flange portion 521 is installed in 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 assembling hole 204 of the cover 20, and the second through hole 104 of the lower plastic 10. Specifically, the second assembling portion 523a of the second fixing portion 523 passes through the second mounting hole 511 and the second assembling hole 204, and the second mating portion 523b of the second fixing portion 523 passes through the second through hole 104. Among them, 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 extending portion 514 is located between the circumferential surface of the second fixing portion 523 of the second pole column 52 and the wall surface of the second assembling hole 204. With this setting, the short-circuit problem caused by the direct contact between the second pole column 52 and the cover 20 of the end cover assembly 120 can be avoided.

[0097] Please refer to Figure 4 , Figure 14 and Figure 17 , Figure 17 is Figure 14 the schematic cross-sectional view of the second welding ring 54 in the second pole column unit 50 shown in

[0098] 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 body 20 away from 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 bump 12, and is fixedly welded to the second pole 52. Specifically, the second welding ring 54 includes a second welding ring body 541 and a second retaining ring 542, and the second retaining ring 542 is fixedly connected to the second welding ring body 541. Among them, the second welding ring body 541 is provided with a second fitting hole 543. The second fitting hole 543 penetrates the second welding ring body 541 in the thickness direction of the second welding ring body 541.

[0099] The second retaining ring 542 is located in the second fitting hole 543 and is fixedly connected to the hole wall surface of the second fitting hole 543.

[0100] Specifically, the second welding ring body 541 is sleeved on the second fitting portion 523b of the second fixing portion 523 in the second pole 52. That is, the second fitting portion 523b penetrates through the second fitting hole 543. In the thickness direction of the end cover assembly 120, the second retaining ring 542 is located on the side of the second fitting portion 523b away from the second assembling portion 523a, and blocks the gap between the second fitting portion 523b and the second welding ring body 541. When the second welding ring 54 is welded to the second pole 52, the second retaining ring 542 melts and fills the gap between the second welding ring body 541 and the second fitting portion 523b of the second pole 52.

[0101] In this embodiment, by providing the second retaining ring 542 on the second welding ring 54 and making the second retaining ring 542 block the assembly gap between the second assembling portion 523a and the second welding ring body 541, when the second welding ring 54 and the second pole 52 are laser welded, the second retaining ring 542 will be first melted by the laser and fill the assembly gap between the second fitting portion 523b and the second welding ring body 541, so as to block the laser from entering the assembly gap between the second fitting portion 523b and the second welding ring body 541, avoid the welding explosion point problem caused by the second upper plastic 51 being burned, and thus help to reduce the welding defect rate between the second pole 52 and the second welding ring 54. At the same time, the circumferential side surface of the second assembling portion 523a is flush with the circumferential side surface of the second fitting portion 523b, so that there is no step structure at the fitting position of the second welding ring body 541 and the second pole 52, which can avoid the interference fit between the second welding ring body 541 and the second pole 52, thereby preventing the second welding ring 54 and the second pole 52 from forming a false sealing state, avoiding products with abnormal sealing states that cannot be detected during the short-circuit and withstand voltage tests of the energy storage device 100, and thus avoiding unqualified products from flowing out, which helps to improve the production quality of the energy storage device 100.

[0102] In this embodiment, the difference between the inner diameter d2 of the second retaining ring 542 and the aperture D2 of the second mating hole 543 is between 0.3 mm and 1 mm. That is to say, the width of the second retaining ring 542 is between 0.3 mm and 1 mm. With this setting, a certain width of the second retaining ring 542 can be ensured to block the gap between the second pole column 52 and the second welding ring body 541, so as to avoid laser from entering the assembly gap between the second pole column 52 and the second welding ring body 541. Furthermore, the problem of welding explosion points caused by the burning of the second upper plastic 51 and the second sealing ring 53 can be avoided, and the welding yield between the second pole column 52 and the second welding ring 54 can be improved. The thickness of the second retaining ring 542 is between 0.2 mm and 0.5 mm to ensure that after the second retaining ring 542 is melted by the laser, it can completely fill the gap between the second pole column 52 and the second welding ring body 541, so as to avoid laser from entering the assembly gap between the second pole column 52 and the second welding ring body 541. Furthermore, the problem of welding explosion points caused by the burning of the second upper plastic 51 and the second sealing ring 53 can be avoided, and the welding yield between the second pole column 52 and the second welding ring 54 can be improved.

[0103] In addition, the second welding ring 54 is further provided with a second avoidance notch 544. Specifically, the second avoidance notch 544 is provided on the second welding ring body 541. The opening of the second avoidance notch 544 is located on the surface of the second welding ring body 541 facing the cover body 20. The second avoidance notch 544 is recessed from the surface of the second welding ring body 541 facing the cover body 20 in a direction away from the cover body 20 and penetrates the circumferential side surface of the second welding ring body 541. The second avoidance notch 544 is arranged around the second mating hole 543 and is spaced from the second mating hole 543, and the second avoidance notch 544 avoids the second convex block 12 of the lower plastic 10. With this setting, the assembly reliability between the second welding ring 54 and the lower plastic 10 can be improved, which helps to improve the assembly reliability of the end cover assembly 120.

[0104] Please refer to Figure 4 , Figure 14 and Figure 18 , Figure 18 which Figure 14 is the schematic structural diagram of the second sealing ring 53 of the second pole column unit 50 shown in

[0105] 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 portion 523a of the second pole column 52 and is clamped between the cover body 20 and the lower plastic 10, and is also clamped between the cover body 20 and the second welding ring 54. The second sealing ring 53 can not only ensure the assembly stability between the second welding ring 54 and the cover body 20, and between the lower plastic 10 and the cover body 20, but also avoid direct contact and conduction between the second welding ring 54 and the cover body 20, realizing insulation between the second welding ring 54 and the cover body 20.

[0106] Specifically, the second sealing ring 53 includes a second sealing body 531, a second sealing flange 532 and a second protruding tooth 533. The second sealing flange 532 and the second protruding tooth 533 are both fixedly connected to the second sealing body 531 and are respectively 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 52 and is clamped between the bottom wall of the second assembly groove 207 of the cover body 20 and the second welding ring body 541 of the second welding ring 54. The second sealing flange 532 is connected to the side of the second sealing body 531 away from the second assembly portion 523a of the second pole 52 and is clamped between the second convex bump 22 of the cover body 20 and the second convex block 12 of the lower plastic 10, and seals the gap between the second convex block 12 and the second convex bump 22. In this embodiment, along the thickness direction of the end cover 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, so as to prevent the second sealing flange 532 from affecting the overall sealing performance of the end cover assembly 120.

[0107] It can be understood that, during the assembly process of the end cover assembly 120, when the second welding ring 54 is welded to the second pole 52, the second welding ring 54 will squeeze the lower plastic 10 and the second sealing ring 53, and by clamping the second sealing flange 532 of the second sealing ring 53 between the second convex bump 22 of the cover body 20 and the second convex block 12 of the lower plastic 10, the second sealing flange 532 is squeezed and compressed, and the gap between the second convex bump 22 and the second convex block 12 is sealed, so that the sealing between the cover body 20 and the lower plastic 10 can be achieved, and the electrolyte inside the energy storage device 100 is prevented from penetrating into the gap between the second convex bump 22 of the cover body 20 and the second convex block 12 of the lower plastic 10 between the cover body 20 and the second welding ring 54, so that the short circuit breakdown problem of the energy storage device 100 in the short circuit and withstand voltage test can be avoided, and the energy storage device 100 is prevented from catching fire and exploding, which helps to improve the safety and reliability of the energy storage device 100.

[0108] The second protruding tooth 533 is connected to one side of the second sealing body 531 facing the second assembly portion 523a of the second pole 52, and abuts against the second assembly portion 523a of the second pole 52, so that the circumference of the second assembly portion 523a of the second pole 52 is spaced apart from the second sealing body 531. Exemplarily, there are a plurality of second protruding teeth 533. The plurality of second protruding teeth 533 are spaced apart from each other.

[0109] In this embodiment, by providing a second convex tooth 533 on the side of the second sealing body 531 of the second sealing ring 53 facing the second pole 52 and making the second convex tooth 533 abut against the second pole 52, the second sealing flange 532 can be separated from the circumferential side surface of the second pole 52 during the compression of the second sealing ring 53, avoiding the false sealing state that may occur when the second sealing body 531 of the second sealing ring 53 is compressed and fits with the second pole 52 or the second upper plastic 51. This can solve the problem that it is difficult to detect when abnormalities occur at the welded joints or other sealed parts of the end cap assembly 120, thereby reducing the outflow rate of defective sealed products and improving the production quality of the energy storage device 100.

[0110] In this embodiment, the second sealing ring 53 further includes a second central plane 53a. The second central plane 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 convex tooth 533. Along the thickness direction of the second sealing ring 53, the second sealing ring 53 is mirror-symmetrical about the second central plane 53a. With this setting, during the assembly process of the end cap assembly 120, there is no need to consider the correct or incorrect placement position of the second sealing ring 53, which helps to reduce the assembly difficulty of the second sealing ring 53 in the end cap assembly 120, and thus is conducive to accelerating the production rhythm of the end cap assembly 120 and improving production efficiency.

[0111] In addition, when the second sealing ring 53 is assembled with the lower plastic 10, a plurality of second guiding 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 setting, it can both limit the assembly position of the second sealing ring 53 in the end cap assembly 120 and ensure that it does not affect the compression space of the second sealing ring 53 when the second sealing ring 53 is compressed.

[0112] Please refer to again Figure 3 and Figure 4 . The end cap assembly 120 further includes a top patch 70. Exemplarily, the top patch 70 is a rectangular thin plate. The top patch 70 is installed on the first surface 20a of the cover body 20, covers the liquid injection hole 202, and blocks at least part of the protruding portion 415. The top patch 70 can play an insulating role. Specifically, the top patch 70 is provided with a first avoidance hole 701, a second avoidance hole 702, and a third avoidance hole 703. The first avoidance hole 701, the second avoidance hole 702, and the third avoidance hole 703 all penetrate the top patch 70 along the thickness direction of the top patch 70 and are spaced apart from each other. Along the length direction of the top patch 70, the first avoidance hole 701 and the second avoidance hole 702 are respectively located on opposite sides of the third avoidance hole 703. Among them, the first avoidance hole 701 avoids the first upper plastic 41, and the second avoidance hole 702 avoids the second upper plastic 51. When the energy storage device 100 undergoes thermal runaway, the third avoidance hole 703 can avoid the explosion-proof valve 30.

[0113] It is understandable that by setting the top sticker 70 and using the top sticker 70 to block the assembly gap between the protruding portion 415 of the first upper plastic 41 and the cover body 20, it is possible to prevent the electrolyte from crystallizing out from the assembly gap between the first upper plastic 41 and the cover body 20, thereby helping to improve the appearance yield of the energy storage device 100 and ensuring that the appearance of the energy storage device 100 is relatively clean. In some other embodiments, when the second upper plastic 51 is provided with the above-mentioned protruding portion 415, the protruding portion 415 of the second upper plastic 51 is installed in the installation groove 205 provided around the second assembly hole 204. At this time, the top sticker 70 can also cover the assembly gap between the protruding portion 415 of the second upper plastic 51 and the cover body 20, preventing the electrolyte from crystallizing out from the assembly gap between the second upper plastic 51 and the cover body 20, thereby also helping to improve the appearance yield of the energy storage device 100 and ensuring that the appearance of the energy storage device 100 is relatively clean.

[0114] Please refer to Figure 19 , Figure 19 is Figure 4 the structural schematic diagram after the shown end cover assembly 120 is welded.

[0115] After the lower plastic 10, the cover body 20, the explosion-proof valve 30, the first pole unit 40 and the second pole unit 50 are assembled, the first pole 42 and the first welding ring 44 in the first pole unit 40, and the second pole 52 and the second welding ring 54 in the second pole unit 50 are welded.

[0116] During the laser welding process of the first welding ring 44 and the first pole 42, the first retaining ring 442 of the first welding ring 44 and the edge of the first pole 42 facing the first retaining ring 442 are melted and mixed together due to the injection of laser welding energy, and then cooled to form the first welding part 45. It can also be understood that the end cover assembly 120 further includes the first welding part 45, and the first welding part 45 is formed by welding the part of the first retaining ring 442 close to the first pole 42 and the part of the first pole 42 close to the first retaining ring 442. Specifically, the first welding part 45 is located on the side of the first welding ring facing the first pole 42, is connected to the first pole 42, and is spaced from the gap between the first welding ring 44 and the first pole 42.

[0117] Under this setting, during the laser welding process of the first pole 42 and the first welding ring 44 by the production personnel, the laser will not directly shoot into the gap between the first pole 42 and the first welding ring body 441 of the first welding ring 44, thereby avoiding the problem of explosion points caused by the first sealing ring 43 and the first upper plastic 41 being burned by the laser, and further helping to improve the welding yield between the first pole 42 and the first welding ring 44.

[0118] Meanwhile, the part of the first retaining ring 442 away from the first pole 42 will also melt under the action of the laser and flow into the gap between the first pole 42 and the first welding ring body 441 of the first welding ring 44, and then cool to form the second welding part 46. It can also be understood that the end cap assembly 120 further includes the second welding part 46. The second welding part 46 is connected between the first welding ring body 441 of the first welding ring 44 and the first welding part 45, and fills the gap between the first welding ring body 441 of the first welding ring 44 and the first pole 42. In this setting, the gap between the first pole 42 and the first welding ring body 441 of the first welding ring 44 is blocked, and the laser can also be blocked from entering, thereby avoiding the explosion point problem caused by the laser burning of the first sealing ring 43 and the first upper plastic 41, and improving the welding yield between the first pole 42 and the first welding ring 44.

[0119] In this embodiment, the welding process of the second pole 52 and the second welding ring 54 is the same. During the laser welding of the second welding ring 54 and the second pole 52, the edge of the second retaining ring 542 of the second welding ring 54 facing the second pole 52 and the edge of the second pole 52 facing the second retaining ring 542 are melted and mixed together due to the injection of laser welding energy, and then cooled to form the third welding part 55. It can also be understood that the end cap assembly 120 further includes the third welding part 55, and the third welding part 55 is formed by welding the part of the second retaining ring 542 close to the second pole 52 and the part of the second pole 52 close to the second retaining ring 542. Specifically, the third welding part 55 is located on the side of the second welding ring 54 facing the second pole 52, is connected to the second pole 52, and is arranged offset from the gap between the second welding ring 54 and the second pole 52.

[0120] In this setting, during the laser welding of the second pole 52 and the second welding ring 54 by the production personnel, the laser will not directly enter the gap between the second pole 52 and the second welding ring body 541 of the second welding ring 54, thereby avoiding the explosion point problem caused by the laser burning of the second sealing ring 53 and the second upper plastic 51, and further helping to improve the welding yield between the second pole 52 and the second welding ring 54.

[0121] Meanwhile, the part of the second retaining ring 542 away from the second pole 52 will also melt under the action of the laser and flow into the gap between the second pole 52 and the first main body 441 of the second welding ring 54, and then cool to form the fourth welding part 56. It can also be understood that the end cap assembly 120 further includes the fourth welding part 56. The fourth welding part 56 is connected between the second main body 541 of the second welding ring 54 and the third welding part 55, and fills the gap between the second main body 541 of the second welding ring 54 and the second pole 52. In this setting, the gap between the second pole 52 and the second main body 541 of the second welding ring 54 is blocked, and the laser can also be blocked from entering, thereby avoiding the problem of explosion points caused by the second sealing ring 53 and the second upper plastic 51 being burned by the laser, and improving the welding yield between the second pole 52 and the second welding ring 54.

[0122] The present application also provides an electrical device, which includes the above energy storage device 100, and the energy storage device 100 supplies power to the electrical device. Among them, the electrical device can be an electric vehicle, a power storage station, a server and other devices that require electricity.

[0123] The above description is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should be covered within the protection scope of the present application; without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An end cap assembly for an energy storage device, characterized in that: It includes a cover body, a welding ring, a pole, an upper plastic and a sealing ring, the cover body includes a first surface and a second surface, along the thickness direction of the cover body, the first surface and the second surface are arranged opposite to each other, the cover body is provided with an assembly hole, and the assembly hole passes through the first surface and the second surface; The pole is passed through the assembly hole, the welding ring is located on the side of the second surface away from the first surface, the welding ring includes a welding ring body and a retaining ring, the welding ring body is sleeved on the pole, the retaining ring is connected to the side of the welding ring facing the pole, and blocks the gap between the welding ring body and the pole; The upper plastic is passed through the assembly hole and connected between the pole and the cover; The sealing ring is sleeved on the pole and clamped between the cover body and the welding ring body.

2. The end cap assembly according to claim 1, characterized in that: The welding ring body is provided with a matching hole, and the matching hole penetrates the welding ring body along the thickness direction of the welding ring body and is connected with the assembly hole; The pole comprises an assembly portion and a matching portion, wherein the assembly portion is inserted into the assembly hole, the matching portion is connected to one side of the assembly portion and is inserted into the matching hole, and the peripheral side surface of the matching portion is flush with the peripheral side surface of the assembly portion; The retaining ring is connected to the hole wall surface of the matching hole, and is arranged around the center of the matching hole, and blocks the gap between the peripheral side surface of the matching portion and the hole wall surface of the matching hole.

3. The end cap assembly according to claim 1 or 2, characterized in that: The width of the retaining ring is between 0.3 mm and 1 mm.

4. The end cap assembly according to claim 1 or 2, characterized in that: The thickness of the retaining ring is between 0.2 mm and 0.5 mm.

5. The end cap assembly according to claim 1, characterized in that: The end cover assembly further includes a lower plastic, the lower plastic is mounted on the second surface, the lower plastic is provided with a through hole, the through hole penetrates the lower plastic along the thickness direction of the lower plastic and is connected with the assembly hole; The sealing ring includes a sealing body and a sealing flange. The sealing body is sleeved on the pole and clamped between the cover body and the welding ring body. The sealing flange is connected to the side of the sealing body away from the pole, and is arranged around the circumference of the sealing body and clamped between the cover body and the lower plastic.

6. The end cap assembly according to claim 5, characterized in that: The lower plastic is also provided with a protrusion, which is connected to the hole wall surface of the through hole and is arranged around the center of the through hole; The cover body is further provided with an assembly groove, the opening of which is located on the second surface, the assembly groove is arranged around the assembly hole and is communicated with the assembly hole, a convex bump is arranged on the side of the cover body facing the lower plastic, the convex bump is arranged in the assembly groove and connected to the groove bottom wall surface of the assembly groove, and along the thickness direction of the end cover assembly, the convex bump is spaced from and arranged opposite to the convex block; The sealing body is clamped between the bottom wall surface of the assembly groove and the surface of the welding ring body facing the cover body, and the sealing flange is clamped between the convex bump and the convex block.

7. The end cap assembly according to claim 6, characterized in that: The welding ring body is provided with an avoidance notch, the opening of the avoidance notch is located on the surface of the welding ring body facing the cover body, and the avoidance notch penetrates the peripheral side surface of the welding ring body, and the avoidance notch avoids the protrusion.

8. An end cap assembly for an energy storage device, characterized in that: The invention comprises a cover body, a welding ring, a pole, a first welding part, an upper plastic and a sealing ring, wherein the cover body comprises a first surface and a second surface, and the first surface and the second surface are arranged opposite to each other along the thickness direction of the cover body, the cover body is provided with an assembly hole, the assembly hole penetrates the first surface and the second surface, the pole is penetrated by the assembly hole, the welding ring is located on the side of the second surface away from the first surface, and is sleeved on the pole, the first welding part is located on the side of the welding ring facing the pole, and is connected to the pole, and is arranged in a staggered manner with the gap between the welding ring and the pole; The upper plastic is passed through the assembly hole and connected between the pole and the cover; The sealing ring is sleeved on the pole and clamped between the cover body and the welding ring.

9. The end cap assembly according to claim 8, characterized in that: The end cover assembly further includes a second welding portion, which is connected between the welding ring and the first welding portion and fills a gap between the welding ring and the pole.

10. An energy storage device, characterized in that: The invention comprises a shell and an end cover assembly according to any one of claims 1 to 9, wherein the end cover assembly is mounted on the shell and closes an opening of the shell.

11. An electrical device, characterized in that: It includes the energy storage device as described in claim 10, and the energy storage device supplies power to the electrical equipment.

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