End cover assembly, energy storage apparatus, and electric device

Abstract

The present application provides an end cover assembly, an energy storage apparatus, and an electric device, which can prevent laser from easily entering an assembly gap between a pole and a welding ring, avoid welding burst points caused by burning of an upper plastic part and a sealing ring, and improving the welding yield of welding between the pole and the welding ring. The end cover assembly comprises a cover body, a welding ring, a pole, an upper plastic part and a sealing ring, the cover body comprises a first surface and a second surface which are arranged opposingly, and the cover body is provided with a mounting hole that passes through the first surface and the second surface; the pole passes through the mounting hole, the welding ring is located on the side of the second surface away from the first surface, and comprises a welding ring body and a shielding ring, the welding ring body is sleeved on the pole, and the shielding ring is connected to the side of the welding ring facing the pole and shields a gap between the welding ring body and the pole; the upper plastic part passes through the mounting 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 body.

Description

End cover assembly, energy storage device and electric equipment

[0001] The present application claims priority to the Chinese patent application No. 202421917884.2, filed on August 08, 2024, and entitled "End cover assembly, energy storage device and electric equipment", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of energy storage, in particular to an end cover assembly, an energy storage device and an electric equipment. BACKGROUND

[0003] A secondary battery, also known as a rechargeable battery or a storage battery, refers to a battery that can be activated by charging after discharging to continue to be used. The recyclable nature of the secondary battery makes it gradually become the main power source of electric equipment. As the demand for secondary batteries gradually increases, people's requirements for the energy density and use reliability of secondary batteries are also increasing. In the existing end cover assembly of the secondary battery, when the pole and the welding ring are laser welded, the laser is easily shot into the assembly gap between the pole and the welding ring, causing the upper plastic and the sealing ring to be burned, resulting in welding burst points, and reducing the welding yield between the pole and the welding ring.

[0004] Practical new type content

[0005] The present application provides an end cover assembly, an energy storage device and an electric equipment, which can prevent the laser from being easily shot into the assembly gap between the pole and the welding ring, avoid the burning of the upper plastic and the sealing ring to cause the welding burst point, and improve the welding yield between the pole and the welding ring.

[0006] In a first aspect, the present application provides an end cover assembly used in an energy storage device. The end cover assembly comprises a cover body, a welding ring, a pole, an upper plastic and a sealing ring. The cover body comprises a first surface and a second surface, which are oppositely arranged along the thickness direction of the cover body. The cover body is provided with an assembly hole, which penetrates through the first surface and the second surface. The pole is arranged in the assembly hole. The welding ring is located on the side of the second surface away from the first surface. The welding ring comprises a welding ring body and a blocking ring. The welding ring body is sleeved on the pole. The blocking ring is connected to the side of the welding ring facing the pole and shields the gap between the welding ring body and the pole. The upper plastic is arranged in 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.

[0007] In a second aspect, the application further provides an end cover assembly for an energy storage device. The end cover assembly comprises a cover body, a welding ring, a pole, a first fusion portion, an upper plastic, and a sealing ring. The cover body comprises a first surface and a second surface, which are oppositely arranged along the thickness direction of the cover body. The cover body is provided with an assembly hole, which penetrates through the first surface and the second surface. The pole is arranged in the assembly hole. The welding ring is arranged on the side of the second surface away from the first surface and is sleeved on the pole. The first fusion portion is arranged 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 arranged in the assembly hole and is connected between the pole and the cover body. The sealing ring is sleeved on the pole and is clamped between the cover body and the welding ring.

[0008] In a third aspect, the application further provides an energy storage device comprising a shell and the end cover assembly as described in any one of the above aspects. The end cover assembly is mounted on the shell and seals the opening of the shell.

[0009] In a fourth aspect, the application further provides an electric device comprising the energy storage device as described above. The energy storage device supplies power to the electric device.

[0010] In the end cover assembly provided by the application, the blocking ring is arranged on the welding ring and blocks the assembly gap between the pole and the welding ring body. The laser is prevented from entering the assembly gap between the pole and the welding ring body, thereby avoiding the welding burst point problem caused by the burning of the upper plastic and the sealing ring, and further helping to improve the welding yield between the pole and the welding ring. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings required to be used by the embodiments of the application will be described below.

[0012] FIG. 1 is a structural schematic view of an energy storage device provided by the embodiments of the application;

[0013] FIG. 2 is a structural schematic view of an end cover assembly in the energy storage device shown in FIG. 1;

[0014] FIG. 3 is an exploded structural schematic view of the end cover assembly shown in FIG. 2;

[0015] FIG. 4 is a cross-sectional structural schematic view of the end cover assembly shown in FIG. 2 after being cut along A-A;

[0016] FIG. 5 is a structural schematic view of a lower plastic in the end cover assembly shown in FIG. 3;

[0017] FIG. 6 is a structural schematic view of the lower plastic shown in FIG. 5 after being cut along B-B;

[0018] Fig. 7 is a structural schematic diagram of the cover and the explosion-proof valve in the end cover assembly shown in Fig. 3;

[0019] Fig. 8 is a structural schematic diagram of the cover shown in Fig. 7 along the section C-C;

[0020] Fig. 9 is an exploded structural schematic diagram of the first pole unit in the end cover assembly shown in Fig. 3;

[0021] Fig. 10 is a structural schematic diagram of the first upper plastic along the section D-D in the first pole unit shown in Fig. 9;

[0022] Fig. 11 is a structural schematic diagram of the first pole along the section E-E in the first pole unit shown in Fig. 9;

[0023] Fig. 12 is a structural schematic diagram of the first welding ring along the section F-F in the first pole unit shown in Fig. 9;

[0024] Fig. 13 is a structural schematic diagram of the first sealing ring along the section G-G in the first pole unit shown in Fig. 9;

[0025] Fig. 14 is an exploded structural schematic diagram of the second pole unit in the end cover assembly shown in Fig. 3;

[0026] Fig. 15 is a structural schematic diagram of the second upper plastic along the section H-H in the second pole unit shown in Fig. 14;

[0027] Fig. 16 is a structural schematic diagram of the second pole along the section I-I in the second pole unit shown in Fig. 14;

[0028] Fig. 17 is a structural schematic diagram of the second welding ring along the section J-J in the second pole unit shown in Fig. 14;

[0029] Fig. 18 is a structural schematic diagram of the second sealing ring along the section K-K in the second pole unit shown in Fig. 14;

[0030] Fig. 19 is a structural schematic diagram of the end cover assembly shown in Fig. 4 after welding.

[0031] The names corresponding to the reference signs in the figures are: energy storage device 100, housing 110, end cover assembly 120, lower plastic 10, cover 20, explosion-proof valve 30, first pole column unit 40, second pole column 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 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, liquid injection hole 202, first assembly hole 203, second assembly hole 204, mounting groove 205, first assembly groove 206, second assembly groove 207, first protruding block 21, second protruding block 22, protective sheet 60, first upper plastic 41, first pole column 42, first sealing ring 43, first welding ring 44, first mounting hole 411, first matching groove 412, first main body part 413, first extension part 414, protruding part 415, first matching surface 401, first connecting surface 402, first side 402a, second side 402b, first flange part 421, first mounting part 422, first fixing part 423, first assembly part 423a, first matching part 423b, first welding ring main body 441, first blocking ring 442, first matching hole 443, first avoidance notch 444, first sealing main body 431, first sealing flange 432, first protruding tooth 433, first central surface 43a, second upper plastic 51, second pole column 52, second sealing ring 53, second welding ring 54, second mounting hole 511, second matching groove 512, second main body part 513, second extension part 514, second matching surface 501, second connecting surface 502, second flange part 521, second fixing part 523, second assembly part 523a, second matching part 523b, second welding ring main body 541, second blocking ring 542, second matching hole 543, second avoidance notch 544, second sealing main body 531, second sealing flange 532, second protruding tooth 533, second central surface 53a, top sheet 70, first avoidance hole 701, second avoidance hole 702, third avoidance hole 703, first fusion part 45, second fusion part 46, third fusion part 55, fourth fusion part 56. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

[0033] Please refer to FIG. 1, which is a structural schematic diagram of an energy storage device 100 provided by the embodiments of the present application. In order to facilitate 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, and the X-axis direction, the Y-axis direction and the Z-axis direction are perpendicular to each other.

[0034] The energy storage device 100 includes a housing 110, a winding core (not shown in the figure), and a cover 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 winding core is received in the receiving cavity. The receiving cavity is also used to receive an electrolyte, and the winding core is soaked in the electrolyte. The cover assembly 120 is installed on the housing 110 and seals 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 can also be a cylindrical battery or other batteries.

[0035] Please refer to FIGS. 2-4, FIG. 2 is a structural schematic diagram of the cover assembly 120 in the energy storage device 100 shown in FIG. 1, FIG. 3 is an exploded structural schematic diagram of the cover assembly 120 shown in FIG. 2, and FIG. 4 is a sectional structural schematic diagram of the cover assembly 120 shown in FIG. 2 along A-A. Wherein, “along A-A” means that the cover assembly 120 is cut along the plane where the line A-A is located, and similar descriptions hereinafter can be understood in the same way.

[0036] The cover 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. Wherein, 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 the opposite sides of the explosion-proof valve 30.

[0037] Please refer to FIGS. 4, 5, and 6, FIG. 5 is a structural schematic diagram of the lower plastic 10 in the cover assembly 120 shown in FIG. 3, and FIG. 6 is a structural schematic diagram of the lower plastic 10 shown in FIG. 5 along B-B.

[0038] 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 oppositely arranged in the thickness direction of the lower plastic 10. Wherein, the first surface 10a is the surface of the lower plastic 10 away from the housing 110, and the second surface 10b is the surface of the lower plastic 10 toward the housing 110. The lower plastic 10 further includes an explosion-proof fence 101, and the explosion-proof fence 101 penetrates 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.

[0039] In the 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 (the Z-axis direction shown in the figure) of the lower plastic 10 and are arranged at intervals from each other. Specifically, along the length direction (the X-axis direction shown in the figure) of the energy storage device 100, the liquid inlet hole 102 is located at the middle of the lower plastic 10 and is arranged at an interval from the explosion-proof fence 101 on one side of the explosion-proof fence 101.

[0040] Along the length direction (the X-axis direction shown in the figure) of the energy storage device 100, the first through hole 103 and the second through hole 104 are both located at the edge of the lower plastic 10 and are arranged at intervals from the liquid inlet hole 102 and the explosion-proof fence 101. In the 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.

[0041] In the 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 hole wall of the first through hole 103. The second protrusion 12 is fixedly connected to the hole wall of the second through hole 104. Along the length direction (the X-axis direction shown in the figure) of the lower plastic 10, the second protrusion 12 is arranged at an interval from the first protrusion 11. Exemplarily, the first protrusion 11 and the second protrusion 12 are both annular.

[0042] In addition, the lower plastic 10 is further provided with a first guide block 13 and a second guide block 14. Specifically, the first surface 10a is provided with the first guide block 13 and the second guide block 14. The first guide block 13 is arranged around the periphery of the first through hole 103. Exemplarily, the first guide block 13 has a plurality of first guide blocks 13. The plurality of first guide blocks 13 are arranged at intervals around the first protrusion 11. Each first guide block 13 comprises a first guide surface 131. The first guide surface 131 is located on the side of the first guide block 13 away from the first through hole 103. Specifically, the first guide surface 131 comprises a first end 131a close to the first surface 10a and a second end 131b arranged away from the first end 131a. 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.

[0043] The second guide block 14 is fixedly connected to the side of the second protrusion 12 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. For example, the second guide block 14 can have a plurality of second guide blocks 14. The plurality of second guide blocks 14 are arranged at intervals 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 between the second guide surface 141 and the second guide block 14 are the same as those of the first guide surface 131 and the first guide block 13, which will not be described here.

[0044] Please refer to FIG. 4, FIG. 7 and FIG. 8. FIG. 7 is a structural schematic diagram of the cover body 20 and the explosion-proof valve 30 in the end cover assembly 120 shown in FIG. 3. FIG. 8 is a sectional structural schematic diagram of the cover body 20 shown in FIG. 7 along the C-C section.

[0045] The cover body 20 includes a first surface 20a and a second surface 20b. The first surface 20a and the second surface 20b are arranged opposite to each other along the thickness direction (the Z-axis direction shown in the figure) of the cover body 20. The first surface 20a is the side of the cover body 20 away from the lower plastic 10, and the second surface 20b is the side of the cover body 20 toward the lower plastic 10.

[0046] The cover body 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. 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 body 20 along the thickness direction (the Z-axis direction shown in the figure) of the cover body 20, and are arranged at intervals.

[0047] Specifically, the explosion-proof hole 201 and the liquid injection hole 202 are both located in the middle of the cover body 20. The explosion-proof hole 201 can be connected to 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 is connected to the liquid inlet hole 102 of the lower plastic 10. The electrolyte can be injected into the accommodation cavity of the shell 110 (as shown in FIG. 1) through the liquid injection hole 202 of the cover body 20 and the liquid inlet hole 102 of the lower plastic 10 in sequence, so as to realize the perfusion of the electrolyte of the energy storage device 100.

[0048] The first assembly hole 203 and the second assembly hole 204 are both located at the edge of the cover 20 along the length direction (X-axis direction in the figure) of the energy storage device 100, and are respectively located at opposite sides of the explosion-proof hole 201 and the liquid injection hole 202. Specifically, the first assembly hole 203 is located at the side of the liquid injection hole 202 away from the explosion-proof hole 201. The second assembly hole 204 is located at the side of the explosion-proof hole 201 away from the liquid injection hole 202. The first assembly hole 203 is in communication with the first through hole 103 of the lower plastic 10 to facilitate installation of the first pole unit 40. The second assembly hole 204 is in communication with the second through hole 104 of the lower plastic 10 to facilitate installation of the second pole unit 50.

[0049] The opening of the mounting groove 205 is located at the first surface 20a of the cover 20. The mounting groove 205 is recessed from the first surface 20a to the second surface 20b. The mounting groove 205 is arranged around the periphery of the first assembly hole 203 and is spaced apart from the first assembly hole 203. In other embodiments, when the liquid injection hole 202 is arranged between the explosion-proof hole 201 and the second assembly hole 204, i.e., the second assembly hole 204 is arranged close to the liquid injection hole 202, the mounting groove 205 can also be arranged around the periphery of the second assembly hole 204 and be spaced apart from the second assembly hole 204.

[0050] In this embodiment, the opening of the first assembly groove 206 and the opening of the second assembly groove 207 are both located at the second surface 20b of the cover 20. The first assembly groove 206 is recessed from the second surface 20b to 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 is in communication with the first assembly hole 203. The second assembly groove 207 is recessed from the second surface 20b to 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 is in communication with the second assembly hole 204. The second assembly groove 207 is spaced apart from the first assembly groove 206 along the length direction of the cover plate.

[0051] In the assembling process 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 are both inclinedly arranged, the first guide surface 131 and the second guide surface 141 can play a guiding and positioning role for the installation of the lower plastic 10. Among them, the first guide block 13 is installed into the first assembly groove 206, so that the first through hole 103 is aligned and communicated with the first assembly hole 203. The second guide block 14 is installed into the second assembly groove 207, so that the second through hole 104 of the lower plastic 10 is aligned and communicated with the second assembly hole 204. With this arrangement, the lower plastic 10 can be prevented from deviating during assembly with the cover 20, so that the lower plastic 10 and the cover 20 can be accurately aligned, thereby ensuring that the first and second pole column units 40 and 50 can be accurately assembled with the cover 20 and the lower plastic 10, and avoiding the problem of poor assembly of the end cover assembly 120.

[0052] In addition, the side of the cover 20 facing the lower plastic 10 is also provided with a first protruding block 21 and a second protruding block 22. Among them, the first protruding block 21 is arranged in the first assembly groove 206 and surrounds the periphery of the first assembly hole 203. Exemplarily, the first protruding block 21 is substantially annular. Along the thickness direction of the end cover assembly 120, the first protruding block 21 is spaced apart from and opposite to the first protruding block 11 of the lower plastic 10. The second protruding block 22 is arranged in the second assembly groove 207 and surrounds the periphery of the second assembly hole 204. Exemplarily, the second protruding block 22 is substantially annular. Along the thickness direction of the end cover assembly 120, the second protruding block 22 is spaced apart from and opposite to the first protruding block 11 of the lower plastic 10.

[0053] It can be understood that by arranging the first protruding block 21 and the second protruding block 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, and further helping to improve the use reliability of the cover 20 and prolong the service life of the cover 20.

[0054] Please continue to refer to FIG. 4 and FIG. 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 outside of the energy storage device 100, when the air pressure inside the energy storage device 100 is too large, the explosion-proof valve 30 will be broken under the action of the air pressure, and the gas inside the energy storage device 100 can be discharged to the outside of the energy storage device 100 in time through the explosion-proof fence 101 of the lower plastic 10 and the explosion-proof hole 201, avoiding explosion of the energy storage device 100 and improving the use reliability of the energy storage device 100.

[0055] In the embodiment, the end cover assembly 120 can further include a protective sheet 60. The protective sheet 60 is mounted to the cover plate and covers the explosion-proof hole 201. The protective sheet 60 is used to protect the explosion-proof valve 30 from damage caused by external environment and external force, thereby preventing the explosion-proof valve 30 from being accidentally touched and ensuring good use reliability of the energy storage device 100.

[0056] Please refer to FIG. 4, FIG. 9 and FIG. 10, FIG. 9 is an exploded structural schematic view of the first pole unit 40 in the end cover assembly 120 shown in FIG. 3, and FIG. 10 is a sectional structural schematic view of the first upper plastic 41 in the first pole unit 40 shown in FIG. 9 along the D-D section.

[0057] The first pole unit 40 includes the first upper plastic 41, the first pole 42, the first sealing ring 43 and the first welding ring 44, and the first upper plastic 41, the first sealing ring 43 and the first welding ring 44 are all sleeved on the first pole 42. The first upper plastic 41 is mounted to the cover body 20 and 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 matching groove 412. The first mounting hole 411 penetrates the first upper plastic 41 along the thickness direction of the first upper plastic 41 and coaxially and communicatively connected to the first assembly hole 203 of the cover body 20. The opening of the first matching groove 412 is located on the surface of the first upper plastic 41 away from the cover body 20. The first matching groove 412 is recessed from the surface of the first upper plastic 41 away from the cover body 20 to the cover body 20 and penetrates the hole wall of the first mounting hole 411 and is in communication with the first mounting hole 411.

[0058] The first upper plastic 41 further includes a first main body 413, a first extension 414 and a protruding part 415, and the first extension 414 and the protruding part 415 are fixedly connected to the first main body 413. The first main body 413 is sleeved on the first pole 42 and located between the first pole 42 and the cover body 20. The first main body 413 is provided with the first matching groove 412 and the first mounting hole 411. The opening of the first matching groove 412 is located on the surface of the first main body 413 away from the cover body 20.

[0059] The first main body part 413 further comprises a first matching surface 401 and a first connecting surface 402 facing away from the cover body 20. The opening of the first matching groove 412 is located on the first matching surface 401. The first matching surface 401 is a plane in an example, so as to facilitate the abutment of the first matching surface 401 and the first pole column 42. The first connecting surface 402 is fixedly connected to the first matching surface 401 and is arranged around the periphery of the first matching surface 401. The first connecting surface 402 is an arc surface in an example. The first connecting surface 402 comprises a first side 402a close to the first pole column 42 and a second side 402b arranged opposite to the first side 402a. The distance between the first connecting surface 402 and the first surface 20a of the cover body 20 gradually decreases in the direction from the first side 402a to the second side 402b. That is, the first connecting surface 402 is an inclined arc surface.

[0060] It can be understood that when the injection nozzle is separated from the injection hole 202 after the energy storage device 100 is finished with liquid injection, the electrolyte is easy to splash onto the surface of the first upper plastic 41. By arranging the first connecting surface 402 in an arc shape on the first upper plastic 41 and inclining the first connecting surface 402, the electrolyte is not easy to remain on the first connecting surface 402, so as to avoid the electrolyte crystallization on the surface of the first upper plastic 41, thereby 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 area of the inclined arc-shaped first connecting surface 402 is large, so even if there is electrolyte remaining on the first connecting surface 402, it is easy to wipe, thereby also helping to prevent electrolyte crystallization on the first connecting surface 402, thereby also helping to keep the appearance of the end cover assembly 120 clean and reducing the appearance defect rate of the energy storage device 100.

[0061] In the embodiment, the first extension part 414 and the protruding part 415 are both fixedly connected to one side of the first main body part 413 facing the cover body 20. The first extension part 414 is arranged around the periphery of the first mounting hole 411. Specifically, the first extension part 414 is mounted in the first assembly hole 203 of the cover body 20.

[0062] The protruding part 415 is arranged in intervals around the periphery of the first extension part 414, and the outer periphery of the protruding part 415 protrudes relative to the outer periphery of the first main body part 413. Specifically, the protruding part 415 is mounted in the mounting groove 205 of the cover body 20. With this arrangement, the assembly gap between the first upper plastic 41 and the cover body 20 can be extended, so as to avoid the electrolyte remaining on the surface of the first upper plastic 41 directly flowing into the assembly gap between the first upper plastic 41 and the cover body 20, thereby being able to reduce 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.

[0063] Please refer to FIG. 9 and FIG. 11, FIG. 11 is a sectional structure schematic diagram of the first pole 42 in the first pole unit 40 shown in FIG. 9 along E-E.

[0064] The first pole 42 penetrates 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. For example, the first pole 42 is a positive pole, and is made of aluminum material. In other embodiments, the first pole 42 can also be a negative pole, and the embodiments of the present application do not make strict restrictions on this.

[0065] In the embodiment, the first pole 42 includes a first flange part 421, a first mounting part 422 and a first fixing part 423, and the first mounting part 422 and the first fixing part 423 are located on one side of the thickness direction of the first flange part 421. Specifically, the first mounting part 422 is fixedly connected to the first flange part 421. Among them, the peripheral side surface of the first flange part 421 protrudes relative to the peripheral side surface of the first mounting part 422. The first fixing part 423 is fixedly connected to one side of the first mounting part 422 away from the first flange part 421. Specifically, the first fixing part 423 includes a first assembly part 423a and a first matching part 423b. The first matching part 423b is connected to one side of the first assembly part 423a, and the peripheral side surface of the first matching part 423b is flush with the peripheral side surface of the first assembly part 423a.

[0066] Specifically, the first flange part 421 of the first pole 42 is located on one side of the first main body part 413 of the first upper plastic 41 away from the cover 20. Among them, the surface of the first flange part 421 towards the first main body part 413 abuts against the first matching surface 401. The peripheral side surface of the first flange part 421 is spaced apart from the first connecting surface 402. That is, the first side 402a of the first connecting surface 402 is spaced apart from the peripheral side surface of the first flange part 421. With this setting, the assembly gap between the first flange part 421 of the first pole 42 and the first main body part 413 can be arranged in the horizontal direction, preventing 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 crystallization of the electrolyte, which in turn helps to reduce the appearance defect rate of the energy storage device 100 and ensure the appearance neatness of the energy storage device 100.

[0067] The first mounting portion 422 of the first pole column 42 is mounted in the first matching groove 412 of the first upper plastic 41. The first fixing portion 423 penetrates 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. Specifically, the first assembly portion 423a of the first fixing portion 423 penetrates the first mounting hole 411 and the first assembly hole 203, and the first matching portion 423b of the first fixing portion 423 penetrates the first through hole 103. One part of the first main body portion 413 is located between the first flange portion 421 and the cover body 20, and the other 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 assembly hole 203. With this arrangement, the short circuit problem of the end cover assembly 120 caused by the direct contact between the first pole column 42 and the cover body 20 can be avoided.

[0068] Please refer to FIG. 4, FIG. 9 and FIG. 12, FIG. 12 is a sectional structure schematic diagram of the first welding ring 44 in the first pole column unit 40 shown in FIG. 9 along F-F.

[0069] In this embodiment, the first welding ring 44 is located on the side of the cover body 20 away from the first upper plastic 41. Specifically, the first welding ring 44 is mounted in the first through hole 103 of the lower plastic 10, and abuts against the first protrusion 11 and is welded and fixed with the first pole column 42. Specifically, the first welding ring 44 includes a first welding ring main body 441 and a first blocking ring 442, and the first blocking ring 442 is fixedly connected to the first welding ring main body 441. The first welding ring main body 441 is provided with a first matching hole 443. The first matching hole 443 penetrates the first welding ring main body 441 along the thickness direction of the first welding ring main body 441. The first blocking ring 442 is located in the first matching hole 443 and is fixedly connected to the hole wall surface of the first matching hole 443.

[0070] Specifically, the first welding ring main body 441 is sleeved on the first matching portion 423b of the first fixing portion 423 of the first pole column 42. That is, the first matching portion 423b penetrates the first matching hole 443. Along the thickness direction of the end cover assembly 120, the first blocking ring 442 is located on the side of the first matching portion 423b away from the first assembly portion 423a, and blocks the gap between the first matching portion 423b and the first welding ring main body 441. When the first welding ring 44 is welded with the first pole column 42, the first blocking ring 442 melts and fills the gap between the first matching portion 423b of the first pole column 42 and the first welding ring main body 441.

[0071] It can be understood that by arranging the first blocking ring 442 on the first welding ring 44 and shielding the assembly gap between the first fitting part 423b of the first pole column 42 and the first welding ring body 441, when the first welding ring 44 and the first pole column 42 are laser welded, the first blocking ring 442 will be melted by laser first and fill the assembly gap between the first fitting part 423b and the first welding ring body 441, so as to block the laser from entering the assembly gap between the first fitting part 423b and the first welding ring body 441, avoid the welding burst point problem caused by the first upper plastic 41 being burned, and further help to improve the welding yield between the first pole column 42 and the first welding ring 44. At the same time, the peripheral side surface of the first assembly part 423a of the first pole column 42 is flush with the peripheral side surface of the first fitting part 423b, so that the fitting position of the first welding ring body 441 and the first pole column 42 has no step structure, which can avoid interference fit between the first welding ring body 441 and the first pole column 42, so as to prevent the first welding ring 44 and the first pole column 42 from forming a false sealing state, so as to avoid that the energy storage device 100 cannot detect the product with abnormal sealing state during short circuit and withstand voltage test, and further avoid the unqualified products from flowing out, which helps to improve the production quality of the energy storage device 100.

[0072] In the embodiment, the difference between the inner diameter d1 of the first blocking ring 442 and the hole diameter D1 of the first fitting hole 443 is between 0.3mm and 1mm. That is, the width of the first blocking ring 442 is between 0.3mm and 1mm. With this setting, the first blocking ring 442 can have a certain width to shield the gap between the first pole column 42 and the first welding ring body 441, so as to avoid the laser from entering the assembly gap between the first pole column 42 and the first welding ring body 441, and further avoid the welding burst point problem caused by the first upper plastic 41 and the first sealing ring 43 being burned, and improve the welding yield between the first pole column 42 and the first welding ring 44. The thickness of the first blocking ring 442 is between 0.2mm and 0.5mm, so as to ensure that the first blocking ring 442 can fill the gap between the first pole column 42 and the first welding ring body 441 after being melted by laser, so as to avoid the laser from entering the assembly gap between the first pole column 42 and the first welding ring body 441, and further avoid the welding burst point problem caused by the first upper plastic 41 and the first sealing ring 43 being burned, and improve the welding yield between the first pole column 42 and the first welding ring 44.

[0073] In addition, the first welding ring 44 is further provided with a first avoiding gap 444. Specifically, the first avoiding gap 444 is arranged on the first welding ring body 441. The opening of the first avoiding gap 444 is located on the surface of the first welding ring body 441 facing the cover body 20. The first avoiding gap 444 is recessed from the surface of the first welding ring body 441 facing the cover body 20 to the direction away from the cover body 20, and penetrates through the circumferential side surface of the first welding ring body 441. The first avoiding gap 444 is arranged around the first matching hole 443 and is spaced apart from the first matching hole 443. The first avoiding gap 444 avoids the first protrusion 11 of the lower plastic 10. With this arrangement, the assembly reliability of the first welding ring 44 and the lower plastic 10 can be improved, thereby helping to improve the assembly reliability of the end cover assembly 120.

[0074] Please refer to FIG. 4, FIG. 9 and FIG. 13, FIG. 13 is a sectional structure schematic diagram of the first sealing ring 43 in the first pole column unit 40 shown in FIG. 9 along G-G.

[0075] The first sealing ring 43 is sleeved on the first fixed part 423 of the first pole column 42, and is clamped between the cover body 20 and the lower plastic 10, and is clamped 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 can avoid the direct contact and conduction between the first welding ring 44 and the cover body 20, thereby realizing the insulation between the first welding ring 44 and the cover body 20.

[0076] Specifically, the first sealing ring 43 includes a first sealing body 431, a first sealing flange 432 and a first protruding tooth 433. The first sealing flange 432 and the first protruding tooth 433 are fixedly connected to the first sealing body 431 and are located on opposite sides of the first sealing body 431, respectively. Specifically, the first sealing body 431 is sleeved on the first fixed part 423 of the first pole column 42 and is clamped between the groove 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 the side of the first sealing body 431 away from the first fixed part 423 of the first pole column 42, and is clamped between the first protrusion 11 of the lower plastic 10 and the first protruding block 21 of the cover body 20, and seals the gap between the first protrusion 11 and the first protruding block 21. In this embodiment, in the thickness direction of the end cover assembly 120, the thickness of the first sealing flange 432 is smaller than the thickness of the first sealing body 431, and the compression amount of the first sealing flange 432 is smaller than the compression amount of the first sealing body 431, so as to prevent the first sealing flange 432 from affecting the overall sealing performance of the end cover assembly 120.

[0077] It can be understood that, in the assembling process of the end cover assembly 120, when the first welding ring 44 is welded with the first pole 42, the first welding ring 44 will extrude the lower plastic 10 and the first sealing ring 43, and by clamping the first sealing flange 432 of the first sealing ring 43 between the first convex 21 of the cover body 20 and the first convex block 11 of the lower plastic 10, the first sealing flange 432 is extruded and compressed, and the gap between the first convex 21 of the cover body 20 and the first convex block 11 of the lower plastic 10 is sealed, so that the sealing between the cover body 20 and the lower plastic 10 can be achieved, preventing the electrolyte inside the energy storage device 100 from penetrating between the first convex 21 of the cover body 20 and the first convex block 11 of the lower plastic 10 and between the cover body 20 and the first welding ring 44, thereby avoiding short-circuit breakdown of the energy storage device 100 in short-circuit and voltage test, preventing the energy storage device 100 from catching fire and exploding, and further helping to improve the safety and reliability of the energy storage device 100.

[0078] The first convex tooth 433 is connected to one side of the first assembly part 423a of the first sealing body 431 facing the first pole 42, and abuts against the first assembly part 423a of the first pole 42, so that the peripheral surface of the first assembly part 423a of the first pole 42 is spaced apart from the first sealing body 431. For example, the first convex tooth 433 has a plurality of first convex teeth 433. The plurality of first convex teeth 433 are spaced apart from each other.

[0079] In this embodiment, by arranging the first convex tooth 433 on the side of the first sealing body 431 of the first sealing ring 43 facing the first pole 42, and abutting the first convex tooth 433 against the first pole 42, the first sealing body 431 can be spaced apart from the peripheral surface of the first pole 42 during the compression of the first sealing ring 43, avoiding the false sealing state caused by the first sealing body 431 of the first sealing ring 43 being compressed and adhering to the first pole 42 or the first upper plastic 41, and solving the problem that the welding or other sealing of the end cover assembly 120 is not easy to detect when it is abnormal, thereby reducing the outflow rate of poor sealing products and improving the production quality of the energy storage device 100.

[0080] In this embodiment, the first sealing ring 43 further comprises 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 tooth 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 arrangement, during the assembly process of the end cover assembly 120, the front and back positions of the first sealing ring 43 do not need to be considered, thereby helping to reduce the assembly difficulty of the first sealing ring 43 in the end cover assembly 120, and further helping to speed up the production rhythm of the end cover assembly 120 and improve the production efficiency.

[0081] In addition, 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 located on the side of the first sealing flange 432 away from the first sealing body 431. With this arrangement, the assembly position of the first sealing ring 43 in the end cover assembly 120 can be limited, and the compression space of the first sealing ring 43 can be ensured when the first sealing ring 43 is compressed.

[0082] Please refer to FIG. 4, FIG. 14 and FIG. 15, FIG. 14 is an exploded structural schematic view of the second pole unit 50 in the end cover assembly 120 shown in FIG. 3, and FIG. 15 is a structural schematic view of the second upper plastic 51 in the second pole unit 50 shown in FIG. 14, along the section H-H.

[0083] 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. The structure of each component in the second pole unit 50, the assembly relationship between components, and the assembly relationship between components and the lower plastic 10 and the cover 20 can be referred to the related description of the first pole unit 40 above, and will not be repeated here.

[0084] 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 body part 513 and a second extension part 514. The positional relationship between the second body part 513 and the second extension part 514 can be referred to the positional relationship between the first body part 413 and the first extension part 414 in the first upper plastic 41 above. The second upper plastic 51 is also provided with a second mounting hole 511 and a second matching groove 512, and the positional relationship between the second mounting hole 511 and the second matching groove 512 in the second upper plastic 51 can be referred to the related description of the first mounting hole 411 and the first matching groove 412 in the first upper plastic 41 above, and will not be repeated here.

[0085] In other embodiments, when the injection hole 202 is arranged between the explosion-proof hole 201 and the second assembly hole 204, i.e. the injection hole 202 is arranged close to the second assembly hole 204, the second upper plastic 51 can also include a protruding part 415 (not shown in FIG. 15), and the positional relationship of the protruding part 415 in the second upper plastic 51 can be referred to the related description of the positional relationship of the protruding part 415 in the first upper plastic 41 above, and will not be repeated here.

[0086] In the embodiment, the second body part 513 comprises a second mating surface 501 and a second connecting surface 502 which are away from the cover 20. The positions of the second mating surface 501 and the second connecting surface 502 in the second body part 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 be referred to the relevant description of the first mating surface 401 and the first connecting surface 402 above, and will not be repeated here.

[0087] Please refer to FIG. 4, FIG. 14 and FIG. 16, FIG. 16 is a structure schematic diagram of the second pole post 52 in the second pole post unit 50 shown in FIG. 14 along the section I-I.

[0088] In the embodiment, the structure of the second pole post 52 is similar to that of the first pole post 42. The difference is that the second pole post 52 comprises a second flange part 521 and a second fixed part 523. The second fixed part 523 is fixedly connected to one side of the thickness direction of the second flange part 521. Among them, the circumferential surface of the second flange part 521 protrudes relative to the circumferential surface of the second fixed part 523. The second fixed part 523 comprises a second assembly part 523a and a second mating part 523b. The second mating part 523b is connected to one side of the second assembly part 523a, and the circumferential surface of the second mating part 523b is flush with the circumferential surface of the second assembly part 523a.

[0089] Specifically, the second flange part 521 is installed in the second mating groove 512, and the second fixed part 523 is arranged 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 part 523a of the second fixed part 523 is arranged through the second mounting hole 511 and the second assembly hole 204, and the second mating part 523b of the second fixed part 523 is arranged through the second through hole 104. Among them, the second body part 513 of the second upper plastic 51 is located between the second flange part 521 and the cover 20, and the second extension part 514 is located between the circumferential surface of the second fixed part 523 of the second pole post 52 and the hole wall surface of the second assembly hole 204. With this arrangement, the short circuit problem caused by the direct contact between the second pole post 52 and the cover 20 can be avoided.

[0090] Please refer to FIG. 4, FIG. 14 and FIG. 17, FIG. 17 is a structure schematic diagram of the second welding ring 54 in the second pole post unit 50 shown in FIG. 14 along the section J-J.

[0091] In the 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 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, and abuts against the second protrusion 12 and is welded and fixed with the second pole column 52. Specifically, the second welding ring 54 includes a second welding ring body 541 and a second blocking ring 542, and the second blocking ring 542 is fixedly connected to the second welding ring body 541. The second welding ring body 541 is provided with a second matching hole 543. The second matching hole 543 penetrates the second welding ring body 541 along the thickness direction of the second welding ring body 541. The second blocking ring 542 is located in the second matching hole 543 and is fixedly connected to the hole wall surface of the second matching hole 543.

[0092] Specifically, the second welding ring body 541 is sleeved on the second matching portion 523b of the second fixed portion 523 of the second pole column 52. That is, the second matching portion 523b is arranged in the second matching hole 543. Along the thickness direction of the end cover assembly 120, the second blocking ring 542 is located on the side of the second matching portion 523b away from the second assembly portion 523a, and blocks the gap between the second matching portion 523b and the second welding ring body 541. When the second welding ring 54 is welded with the second pole column 52, the second blocking ring 542 is melted and fills the gap between the second matching portion 523b and the second welding ring body 541.

[0093] In the embodiment, by arranging the second blocking ring 542 on the second welding ring 54 and blocking the assembly gap between the second assembly portion 523a and the second welding ring body 541, when the second welding ring 54 and the second pole column 52 are laser welded, the second blocking ring 542 will be melted by laser first, and fill the assembly gap between the second matching portion 523b and the second welding ring body 541, so as to block the laser from entering the assembly gap between the second matching portion 523b and the second welding ring body 541, avoid the welding burst point problem caused by the second upper plastic 51 being burned, and further help to reduce the welding failure rate between the second pole column 52 and the second welding ring 54. At the same time, the peripheral side surface of the second assembly portion 523a is flush with the peripheral side surface of the second matching portion 523b, so that the matching position of the second welding ring body 541 and the second pole column 52 has no step structure, which can avoid interference fit between the second welding ring body 541 and the second pole column 52, so as to prevent the second welding ring 54 and the second pole column 52 from forming a false sealing state, so as to avoid that the product with abnormal sealing state cannot be detected when the energy storage device 100 is subjected to short circuit and withstand voltage test, and further avoid the unqualified products from flowing out, and help to improve the production quality of the energy storage device 100.

[0094] In the embodiment, the difference between the inner diameter d2 of the second blocking ring 542 and the hole diameter D2 of the second matching hole 543 is between 0.3 mm and 1 mm. That is, the width of the second blocking ring 542 is between 0.3 mm and 1 mm. With the arrangement, the second blocking ring 542 can have a certain width to shield the gap between the second pole column 52 and the second welding ring body 541, so that the laser can be prevented from entering the assembly gap between the second pole column 52 and the second welding ring body 541, thereby avoiding the welding burst point problem caused by the second upper plastic 51 and the second sealing ring 53 being burned, and improving the welding yield between the second pole column 52 and the second welding ring 54. The thickness of the second blocking ring 542 is between 0.2 mm and 0.5 mm, so that the second blocking ring 542 can completely fill the gap between the second pole column 52 and the second welding ring body 541 after being melted by the laser, thereby avoiding the laser from entering the assembly gap between the second pole column 52 and the second welding ring body 541, and thereby avoiding the welding burst point problem caused by the second upper plastic 51 and the second sealing ring 53 being burned, and improving the welding yield between the second pole column 52 and the second welding ring 54.

[0095] In addition, the second welding ring 54 is further provided with a second avoiding notch 544. Specifically, the second avoiding notch 544 is arranged on the second welding ring body 541. The opening of the second avoiding notch 544 is located on the surface of the second welding ring body 541 facing the cover body 20. The second avoiding notch 544 is recessed from the surface of the second welding ring body 541 facing the cover body 20 to the direction away from the cover body 20, and penetrates through the peripheral side surface of the second welding ring body 541. The second avoiding notch 544 is arranged around the second matching hole 543 and is arranged in a spaced manner with the second matching hole 543, and the second avoiding notch 544 avoids the second protrusion 12 of the lower plastic 10. With the arrangement, the assembly reliability of the second welding ring 54 and the lower plastic 10 can be improved, thereby helping to improve the assembly reliability of the end cover assembly 120.

[0096] Please refer to FIGS. 4, 14 and 18. FIG. 18 is a structure schematic view of the second sealing ring 53 along K-K in the second pole column unit 50 shown in FIG. 14.

[0097] In the 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 column 52, and is clamped between the cover body 20 and the lower plastic 10, and is 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 can avoid the direct contact and conduction between the second welding ring 54 and the cover body 20, thereby realizing the insulation between the second welding ring 54 and the cover body 20.

[0098] Specifically, the second sealing ring 53 comprises 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 fixedly connected to the second sealing body 531 and are located on opposite sides of the second sealing body 531, respectively. 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 second welding ring body 541 of the second welding ring 54 and the groove bottom wall of the second assembly groove 207 of the cover body 20. 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 post 52 and is clamped between the second protruding block 12 of the lower plastic 10 and the second protruding block 22 of the cover body 20 and seals the gap between the second protruding block 12 and the second protruding block 22. In this embodiment, the thickness of the second sealing flange 532 is smaller than the thickness of the second sealing body 531 in the thickness direction of the end cover assembly 120, and the compression amount of the second sealing flange 532 is smaller 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.

[0099] It can be understood that, in the assembly process of the end cover assembly 120, when the second welding ring 54 is welded with the second pole post 52, the second welding ring 54 will extrude 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 protruding block 22 of the cover body 20 and the second protruding block 12 of the lower plastic 10, the second sealing flange 532 is extruded and compressed, and the gap between the second protruding block 22 and the second protruding block 12 is sealed, so as to realize the sealing between the cover body 20 and the lower plastic 10, prevent the electrolyte inside the energy storage device 100 from penetrating into the space between the cover body 20 and the second welding ring 54 through the gap between the second protruding block 22 of the cover body 20 and the second protruding block 12 of the lower plastic 10, thereby avoiding the short circuit breakdown problem of the energy storage device 100 in the short circuit and voltage test, preventing the energy storage device 100 from catching fire and exploding, and further helping to improve the safety and reliability of the energy storage device 100.

[0100] The second protruding tooth 533 is connected to the side of the second sealing body 531 facing the second assembly portion 523a of the second pole post 52 and abuts against the second assembly portion 523a of the second pole post 52, so that the peripheral surface of the second assembly portion 523a of the second pole post 52 is spaced apart from the second sealing body 531. For example, the second protruding tooth 533 has a plurality of second protruding teeth 533. The plurality of second protruding teeth 533 are spaced apart from each other.

[0101] In the embodiment, the second protrusion 533 is arranged on the side of the second sealing main body 531 of the second sealing ring 53 facing the second pole column 52, and the second protrusion 533 is in abutment with the second pole column 52. In this way, the second sealing flange 532 can be separated from the circumferential surface of the second pole column 52 during compression of the second sealing ring 53, so that the false sealing state caused by the second sealing main body 531 of the second sealing ring 53 being in abutment with the second pole column 52 or the second upper plastic 51 after being compressed can be avoided. In this way, the problem that the welding part or other sealing part of the end cover assembly 120 cannot be easily detected when an abnormality occurs can be solved, so that the outflow rate of poor sealing products can be reduced, and the production quality of the energy storage device 100 can be improved.

[0102] In the embodiment, the second sealing ring 53 further includes a second central surface 53a. The second central surface 53a is perpendicular to the thickness direction of the second sealing ring 53 and passes through the second sealing main body 531, the second sealing flange 532 and the second protrusion 533. The second sealing ring 53 is mirror-symmetrical about the second central surface 53a along the thickness direction of the second sealing ring 53. In this way, during assembly of the end cover assembly 120, the front and back positions of the second sealing ring 53 do not need to be considered, so that the assembly difficulty of the second sealing ring 53 in the end cover assembly 120 can be reduced, and the production rhythm of the end cover assembly 120 can be accelerated, and the production efficiency can be improved.

[0103] In addition, 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 located on the side of the second sealing flange 532 away from the second sealing main body 531. In this way, the assembly position of the second sealing ring 53 in the end cover assembly 120 can be limited, and the compression space of the second sealing ring 53 can be ensured when the second sealing ring 53 is compressed.

[0104] Please refer to FIG. 3 and FIG. 4 again. The end cover assembly 120 further includes a top piece 70. The top piece 70 is a rectangular thin plate. The top piece 70 is installed on the first surface 20a of the cover body 20 and covers the liquid injection hole 202 and at least partially covers the protruding part 415. The top piece 70 can have an insulation effect. Specifically, the top piece 70 is provided with a first avoiding hole 701, a second avoiding hole 702 and a third avoiding hole 703. The first avoiding hole 701, the second avoiding hole 702 and the third avoiding hole 703 all penetrate the top piece 70 along the thickness direction of the top piece 70 and are spaced apart from each other. Along the length direction of the top piece 70, the first avoiding hole 701 and the second avoiding hole 702 are respectively located on the opposite sides of the third avoiding hole 703. The first avoiding hole 701 avoids the first upper plastic 41, and the second avoiding hole 702 avoids the second upper plastic 51. When the energy storage device 100 has thermal runaway, the third avoiding hole 703 can avoid the explosion-proof valve 30.

[0105] It can be understood that, by setting the top post sheet 70 and shielding the assembly gap between the protruding portion 415 of the first upper plastic 41 and the cover 20 with the top post sheet 70, the crystallization of electrolyte from the assembly gap between the first upper plastic 41 and the cover 20 can be prevented, 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 neat. In some other embodiments, when the second upper plastic 51 is provided with the protruding portion 415 described above, the protruding portion 415 of the second upper plastic 51 is installed in the mounting groove 205 arranged around the second assembly hole 204. At this time, the top post sheet 70 can also cover the assembly gap between the protruding portion 415 of the second upper plastic 51 and the cover 20, prevent the crystallization of electrolyte from the assembly gap between the second upper plastic 51 and the cover 20, and thereby also help to improve the appearance yield of the energy storage device 100 and ensure that the appearance of the energy storage device 100 is relatively neat.

[0106] Please refer to FIG. 19, which is a structural schematic diagram of the end cover assembly 120 after being completed welding.

[0107] When the lower plastic 10, the cover 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.

[0108] In the process of laser welding the first welding ring 44 and the first pole 42, the edge of the first blocking ring 442 of the first welding ring 44 towards the first pole 42 and the edge of the first pole 42 towards the first blocking ring 442 melt together due to the injection of laser welding energy, and then cool to form the first fusion portion 45. It can also be understood that the end cover assembly 120 further comprises the first fusion portion 45, and the first fusion portion 45 is formed by fusion of the portion of the first blocking ring 442 close to the first pole 42 and the portion of the first pole 42 close to the first blocking ring 442. Specifically, the first fusion portion 45 is located on the side of the first welding ring towards the first pole 42, connected to the first pole 42, and spaced apart from the gap between the first welding ring 44 and the first pole 42.

[0109] With this arrangement, in the process of laser welding the first pole 42 and the first welding ring 44, the laser will not directly enter the gap between the first pole 42 and the first welding ring main body 441 of the first welding ring 44, thereby avoiding the problem of burst points caused by the laser burning the first sealing ring 43 and the first upper plastic 41, and thereby helping to improve the welding yield between the first pole 42 and the first welding ring 44.

[0110] Meanwhile, the portion of the first blocking ring 442 away from the first pole post 42 will also melt under the action of the laser and flow into the gap between the first pole post 42 and the first welding ring main body 441 of the first welding ring 44, and then cool to form a second fusion portion 46. It can also be understood that the end cover assembly 120 further comprises the second fusion portion 46. The second fusion portion 46 is connected between the first welding ring main body 441 of the first welding ring 44 and the first fusion portion 45, and fills the gap between the first welding ring main body 441 of the first welding ring 44 and the first pole post 42. Under this arrangement, the gap between the first pole post 42 and the first welding ring main body 441 of the first welding ring 44 is blocked, and the laser can also be blocked from entering, thereby avoiding the problem of popping caused by the first sealing ring 43 and the first upper plastic 41 being burned by the laser, and improving the welding yield between the first pole post 42 and the first welding ring 44.

[0111] In this embodiment, the welding process of the second pole post 52 and the second welding ring 54 is the same. During the laser welding of the second welding ring 54 and the second pole post 52, the edge of the second blocking ring 542 of the second welding ring 54 towards the second pole post 52 and the edge of the second pole post 52 towards the second blocking ring 542 melt together due to the injection of laser welding energy, and then cool to form a third fusion portion 55. It can also be understood that the end cover assembly 120 further comprises the third fusion portion 55, and the third fusion portion 55 is formed by the portion of the second blocking ring 542 close to the second pole post 52 and the portion of the second pole post 52 close to the second blocking ring 542. Specifically, the third fusion portion 55 is located on the side of the second welding ring 54 towards the second pole post 52, is connected to the second pole post 52, and is arranged in a staggered manner with the gap between the second welding ring 54 and the second pole post 52.

[0112] Under this arrangement, during the laser welding of the second pole post 52 and the second welding ring 54, the laser will not directly enter the gap between the second pole post 52 and the second welding ring main body 541 of the second welding ring 54, thereby avoiding the problem of popping caused by the second sealing ring 53 and the second upper plastic 51 being burned by the laser, and thereby helping to improve the welding yield between the second pole post 52 and the second welding ring 54.

[0113] Meanwhile, the portion of the second retaining ring 542 away from the second pole post 52 is also melted under the action of the laser and flows into the gap between the second pole post 52 and the first retaining ring body 441 of the second retaining ring 54, and then cools to form a fourth fusion portion 56. It can also be understood that the end cover assembly 120 further comprises the fourth fusion portion 56. The fourth fusion portion 56 is connected between the second retaining ring body 541 of the second retaining ring 54 and the third fusion portion 55, and fills the gap between the second retaining ring body 541 of the second retaining ring 54 and the second pole post 52. Under this arrangement, the gap between the second pole post 52 and the second retaining ring body 541 of the second retaining ring 54 is blocked, and the laser can also be blocked from entering, thereby avoiding the problem of burst 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 post 52 and the second retaining ring 54.

[0114] The application also provides a power-using device, which comprises the above-mentioned energy storage device 100, and the energy storage device 100 supplies power to the power-using device. The power-using device can be a new energy vehicle, a power storage station, a server, or other devices that need to use power.

[0115] The above description is only a specific embodiment of the application, but the protection scope of the application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the application, which should be covered within the protection scope of the application. In the case of no conflict, the embodiments of the application and the features in the embodiments can be combined with each other. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. An end cap assembly for an energy storage device, comprising: The end cover assembly comprises a cover body, a welding ring, a pole, an upper plastic and a sealing ring. The cover body comprises a first surface and a second surface, which are oppositely arranged along the thickness direction of the cover body. The cover body is provided with an assembly hole, which penetrates the first surface and the second surface. The pole is arranged in the assembly hole. The welding ring is arranged on the side of the second surface away from the first surface. The welding ring comprises a welding ring body and a blocking ring. The welding ring body is sleeved on the pole. The blocking ring is connected to the side of the welding ring body facing the pole and shields the gap between the welding ring body and the pole. The upper plastic is arranged in 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. The welding ring body is provided with a matching hole, which penetrates the welding ring body along the thickness direction of the welding ring body and communicates with the assembly hole. The pole comprises an assembly part and a matching part. The assembly part is arranged in the assembly hole. The matching part is connected to one side of the assembly part and arranged in the matching hole. The peripheral side surface of the matching part is flush with the peripheral side surface of the assembly part. The blocking ring is connected to the hole wall surface of the matching hole and arranged around the center of the matching hole, and shields the gap between the peripheral side surface of the matching part and the hole wall surface of the matching hole. The width of the blocking ring is between 0.3mm and 1mm. The thickness of the blocking ring is between 0.2mm and 0.5mm. The end cover assembly further comprises a lower plastic. The lower plastic is arranged on the second surface. The lower plastic is provided with a through hole, which penetrates the lower plastic along the thickness direction of the lower plastic and communicates with the assembly hole. The sealing ring comprises 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 arranged around the peripheral side of the sealing body. The sealing flange is clamped between the cover body and the lower plastic. The lower plastic is further provided with a protrusion. The protrusion is connected to the hole wall surface of the through hole and 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 arranged on the second surface. The assembly groove is arranged around the assembly hole and communicates with the assembly hole. The side of the cover body facing the lower plastic is provided with a convex block. The convex block is arranged in the assembly groove and connected to the groove bottom wall surface of the assembly groove. Along the thickness direction of the end cover assembly, the convex block is spaced apart from and opposite to the protrusion. 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. The sealing flange is clamped between the convex block and the protrusion.

2. The end cap assembly of claim 1, wherein, The welding ring body is provided with an avoiding notch. The opening of the avoiding notch is arranged on the surface of the welding ring body facing the cover body. The avoiding notch penetrates the peripheral side surface of the welding ring body. The avoiding notch avoids the protrusion. ​ ​ 3. The end cap assembly of claim 1 or 2, wherein, ​ 4. The end cap assembly of claim 1 or 2, wherein, ​ 5. The end cap assembly of claim 1, wherein, ​ ​ 6. The end cap assembly of claim 5, wherein, ​ ​ ​ 7. The end cap assembly of claim 6, wherein, ​ 8. An end cap assembly for an energy storage device, comprising: The end cover assembly comprises a cover, a welding ring, a pole, a first fusion part, an upper plastic and a sealing ring. The cover comprises a first surface and a second surface, which are oppositely arranged along the thickness direction of the cover. The cover is provided with an assembly hole, which penetrates the first surface and the second surface. The pole is arranged in the assembly hole. The welding ring is arranged on the side of the second surface away from the first surface and is sleeved on the pole. The first fusion part is arranged on the side of the welding ring facing the pole, 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 arranged in the assembly hole and is connected between the pole and the cover. The sealing ring is sleeved on the pole and is clamped between the cover and the welding ring.

9. The end cap assembly of claim 8, wherein, The end cover assembly further comprises a second fusion part, which is connected between the welding ring and the first fusion part and fills the gap between the welding ring and the pole.

10. An energy storage device, characterized by, The end cover assembly comprises a housing and the end cover assembly according to any one of claims 1 to 9, which is mounted on the housing and seals the opening of the housing.

11. An electrical device, characterized by The energy storage device according to claim 10 is used to supply power to the electric device.

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