End cover assembly, energy storage device and electric equipment

Abstract

The utility model provides an end cover assembly, an energy storage device and electric equipment. The end cover assembly comprises a cover body, a pressing ring and a pole, the cover body is provided with an assembling hole, the assembling hole penetrates through the cover body in the thickness direction of the cover body, the pressing ring is located on one side of the cover body in the thickness direction, the pressing ring is provided with a matching hole, the matching hole penetrates through the pressing ring in the thickness direction of the pressing ring and is communicated with the assembling hole, and the pole penetrates through the assembling hole and the matching hole. The pressing ring is welded and fixed; wherein the pole comprises a pole connecting surface deviating from the cover body, the pressing ring comprises a pressing ring connecting surface deviating from the cover body, the pressing ring connecting surface is arranged around the matching hole and the pole connecting surface, and at least one of the pole connecting surface and the pressing ring connecting surface is a rough surface.

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] A rechargeable battery, also known as a rechargeable battery or storage battery, is 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, the pole and the pole pressure ring are prone to cold welding or poor welding during the welding process, which reduces the welding stability between the pole and the pole pressure ring. Utility Model Content

[0003] The present application provides an end cover assembly, an energy storage device and an electrical equipment, which can avoid reflection between the pole and the pressure ring during the welding process, avoid the problem of false welding or poor welding between the pressure ring and the pole, and improve the welding yield and welding stability between the pole and the pressure 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 pressure ring and a pole, the cover body includes a first surface and a second surface, 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 along the thickness direction of the cover body, the pressure ring is located on one side of the thickness direction of the cover body, the pressure ring is provided with a matching hole, the matching hole penetrates the pressure ring along the thickness direction of the pressure ring, and is connected with the assembly hole, the pole is penetrated by the assembly hole and the matching hole, and is welded and fixed with the pressure ring; wherein, the pole includes a pole connection surface away from the cover body, the pole connection surface is located on the side of the first surface away from the second surface, the pressure ring includes a pressure ring connection surface away from the cover body, the pressure ring connection surface is located on the side of the first surface away from the second surface, and is connected to the pole connection surface and arranged around the pole connection surface, and at least one of the pole connection surface and the pressure ring connection surface is a rough surface.

[0005] Among them, the pole includes a fixing part and a matching part, the fixing part is installed in the matching hole, and the fixing part includes the pole connection surface; the matching part is fixedly connected to one side of the fixing part and is installed in the assembly hole, and the peripheral side surface of the matching part is arranged around the peripheral side surface of the fixing part and protrudes relative to the peripheral side surface of the fixing part; the end cover assembly also includes an upper plastic, the upper plastic is penetrated through the assembly hole, and is located between the peripheral side surface of the matching part and the hole wall surface of the assembly hole.

[0006] The peripheral side surface of the matching portion includes a first position point, the projection of the first position point on the surface where the peripheral side surface of the fixing portion is located is a second position point, and the distance between the second position point and the first position point is between 0.8 mm and 2.0 mm.

[0007] Wherein, the fixing portion includes a connected pole mounting portion and a pole welding portion, the pole welding portion is arranged around the circumference of the pole mounting portion, and the pole welding portion includes the pole connecting surface; the pressure ring includes a connected pressure ring mounting portion and a pressure ring welding portion, the pressure ring mounting portion is arranged around the circumference of the pressure ring welding portion, and the pressure ring welding portion includes the pressure ring connecting surface; when the pole is welded and fixed to the pressure ring, part of the pole welding portion and part of the pressure ring welding portion are fused to form a weld mark, and the weld mark includes an outer edge away from the pole mounting portion and an inner edge arranged opposite to the outer edge, and the distance between the inner edge and the outer edge is between 0.5 mm and 2.5 mm.

[0008] Wherein, along the thickness direction of the end cover assembly, the distance between the end of the weld mark close to the cover body and the end of the weld mark away from the cover body is between 0.4 mm and 1.4 mm.

[0009] The peripheral side surface of the pole mounting portion is spaced apart from the hole wall surface of the matching hole, and the pole welding portion fills the gap between the hole wall surface of the matching hole and the peripheral side surface of the pole mounting portion.

[0010] Wherein, the fixing portion is transitionally matched with the matching hole.

[0011] Wherein, the pressure ring also includes a mounting surface and a guide surface. Along the thickness direction of the pressure ring, the mounting surface and the pressure ring connecting surface are arranged opposite to each other, and the guide surface is fixedly connected between the mounting surface and the hole wall surface of the matching hole.

[0012] Wherein, the guide surface includes a first point on a side close to the mounting surface and a second point on a side close to the hole wall of the matching hole, the projection of the first point on the surface where the hole wall of the matching hole is located is the first projection point, and the projection of the second point on the surface where the mounting surface is located is the second projection point; the ratio of the distance a between the first point and the first projection point to the distance b between the second point and the second projection point is 0.5≤a / b≤1.

[0013] In a second aspect, the present application further provides an energy storage device, comprising a shell and an end cover assembly as described in any one of the above items, wherein the end cover assembly is mounted on the shell and closes an opening of the shell.

[0014] In a third aspect, the present application further provides an electrical device, comprising the energy storage device as described above, wherein the energy storage device supplies power to the electrical device.

[0015] In the end cap assembly provided by the present application, by setting at least one of the pole connection surface or the pressure ring connection surface as a rough surface, the reflection interference between the pressure ring and the pole during the welding process can be avoided, and the absorption rate of the pressure ring and the pole to the laser light energy can be improved. On the one hand, it is helpful to avoid the problem of cold welding or poor welding between the pressure ring and the pole, and improve the welding yield and welding stability between the pole and the pressure ring. On the other hand, the welding fixation between the pole and the pressure ring can be achieved by using a laser welding device with a relatively low power, which helps to save energy and reduce production costs. At the same time, it can also avoid the laser head lens of the laser welding equipment from being ablated by the reflected laser, and avoid damage to the laser welding equipment, thereby helping to extend the service life of the laser welding equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be described below.

[0017] Figure 1 is a schematic diagram of the structure of the energy storage device provided in an embodiment of the present application;

[0018] Figure 2 yes Figure 1 The schematic diagram of the structure of the end cover assembly in the energy storage device shown in the first embodiment;

[0019] Figure 3 yes Figure 2 An exploded structural diagram of the end cap assembly shown;

[0020] Figure 4a yes Figure 2 The cross-sectional structure diagram of the end cover assembly after being cut along AA;

[0021] Figure 4b yes Figure 4aA magnified schematic diagram of area a in the middle;

[0022] Figure 4c yes Figure 4a A magnified schematic diagram of area b;

[0023] Figure 5 yes Figure 3 A schematic diagram of the structure of the lower plastic, cover body and explosion-proof valve in the end cover assembly shown;

[0024] Figure 6 yes Figure 3 A schematic diagram of the exploded structure of the first pole unit in the end cover assembly shown;

[0025] Figure 7 yes Figure 6 The schematic diagram of the cross-sectional structure of the first upper plastic in the first pole unit after being cut along BB;

[0026] Figure 8 yes Figure 6 A schematic diagram of the cross-sectional structure of the first pole in the first pole unit after being cut along CC;

[0027] Fig. 9 yes Figure 6 The schematic diagram of the cross-sectional structure of the first pressure ring in the first pole unit after being cut along DD;

[0028] Fig.10 yes Figure 3 A schematic diagram of the exploded structure of the second pole unit in the end cover assembly shown;

[0029] Fig.11 yes Fig.10 The schematic diagram of the cross-sectional structure of the second upper plastic in the second pole unit after being cut along EE;

[0030] Fig.12 yes Fig.10 A schematic diagram of the cross-sectional structure of the second pole in the second pole unit after being cut along FF;

[0031] Fig.13 yes Fig.10 A schematic diagram of the cross-sectional structure of the second pressure ring in the second pole unit after being cut along GG;

[0032] Fig.14 yes Figure 1 The schematic diagram of the structure of the end cover assembly in the energy storage device shown in the second embodiment;

[0033] Fig.15a yes Fig.14 The cross-sectional structure diagram of the end cover assembly after being cut along HH;

[0034] Fig.15b yes Fig.15a A magnified schematic diagram of the middle c area;

[0035] Fig.15c yes Fig.15a The enlarged schematic diagram of the middle d area;

[0036] Fig.16a yes Figure 1 A schematic cross-sectional structure diagram of an end cover assembly in the energy storage device in a third embodiment;

[0037] Fig.16b yes Fig.16a A magnified schematic diagram of the middle e area;

[0038] Fig.16c yes Fig.16a Enlarged schematic diagram of the middle f area;

[0039] Fig.17 yes Fig.16c Schematic diagram of the enlarged area I in the middle.

[0040] The names corresponding to the reference numerals in the figures are:

[0041] Energy storage device 100, housing 110, end cover assembly 120, lower plastic 10, cover body 20, explosion-proof valve 30, first pole unit 40, second pole unit 50, explosion-proof fence 101, liquid inlet hole 102, through hole 103, avoidance groove 104, first through hole 103a, second through hole 103b, first avoidance groove 104a, second avoidance groove 104b, first surface 21, second surface 22, explosion-proof hole 201, injection hole 202, assembly hole 203 , first assembly hole 203a, second assembly hole 203b, first upper plastic 41, first pole 42, first seal 43, first pressure ring 44, first main body 411, first extension 412, first matching groove 413, first mounting hole 414, first pole connecting surface 42a, first flange 421, first matching portion 422, first fixing portion 423, first pole welding portion 4231, first pole mounting portion 4232, first matching hole 441 , first hole wall 441a, first sink 445, first pressure ring connection surface 442, first mounting surface 443, first pressure ring welding portion 44a, first pressure ring mounting portion 44b, first assembly surface 446, first weld mark 401, first outer edge 401a, first inner edge 401b, second upper plastic 51, second pole 52, second seal 53, second pressure ring 54, second pole connection surface 52a, second flange portion 521, second matching portion 522, Second fixing portion 523, second pole welding portion 5231, second pole mounting portion 5232, second matching hole 541, second hole wall surface 541a, second recessed groove 545, second pressure ring connecting surface 542, second mounting surface 543, second pressure ring welding portion 54a, second pressure ring mounting portion 54b, second assembly surface 546, second weld mark 501, second outer edge 501a, second inner edge 501b, first guide surface 444, second guide surface 544. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0043] See also Figure 1 , Figure 1 1 is a schematic diagram of the structure of the energy storage device 100 provided in an embodiment of the present application. 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, and the height direction of the energy storage device 100 is defined as the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other.

[0044] The energy storage device 100 includes a shell 110, a winding core (not shown) and an end cap assembly 120. The shell 110 has an opening (not shown) and a receiving cavity (not shown), and the opening is connected to 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 immersed in the electrolyte. The end cap assembly 120 is installed on the top side of the shell 110 in the height direction of the energy storage device 100 (Z-axis direction shown in the figure) and closes the opening. 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.

[0045] It should be noted that the directional terms such as "top" and "bottom" involved in this application are referenced to the attached Figure 1 The description of the orientation shown uses the positive direction of the Z-axis as the "top" and the negative direction of the Z-axis as the "bottom". Similar descriptions below may be understood in the same way, but they do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0046] See also Figure 2 , Figure 3 , Figure 4a , Figure 4b and Figure 4c , Figure 2 yes Figure 1 The schematic diagram of the structure of the end cover assembly 120 in the energy storage device 100 in the first embodiment is shown. Figure 3 yes Figure 2 The exploded structural diagram of the end cap assembly 120 is shown in FIG. Figure 4a yes Figure 2 The cross-sectional structure diagram of the end cover assembly 120 after being cut along AA is shown. Figure 4b yes Figure 4a The enlarged schematic diagram of area a in the middle. Figure 4c yes Figure 4a The enlarged schematic diagram of the region b in the middle. Here, "cut along AA" means cutting along the plane where the AA line is located, and similar descriptions in the following text can be understood in the same way.

[0047] The end cap assembly 120 includes a lower plastic 10, a cover 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 in the thickness direction of the cover 20. The explosion-proof valve 30, the first pole unit 40, and the second pole unit 50 are all installed on the cover 20. In 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.

[0048] Please refer to Figure 4b , Figure 4c and Figure 5 , Figure 5 yes Figure 3 The end cover assembly 120 is a schematic structural diagram of the lower plastic 10, the cover body 20 and the explosion-proof valve 30.

[0049] The lower plastic 10 includes an explosion-proof fence 101, and the explosion-proof fence 101 passes through the top surface (not marked in the figure) and the bottom surface (not marked in the figure) of the lower plastic 10. Among them, the explosion-proof fence 101 is located in the middle of the lower plastic 10. The lower plastic 10 is also provided with a liquid inlet hole 102, a through hole 103 and an avoidance groove 104. Among them, the liquid inlet hole 102 and the through hole 103 both pass through the lower plastic 10 along the thickness direction of the lower plastic 10 (Z-axis direction shown in the figure). Specifically, along the length direction of the energy storage device 100 (X-axis direction shown in the figure), the liquid inlet hole 102 is located in the middle of the lower plastic 10, and is located on one side of the explosion-proof fence 101, and is spaced apart from the explosion-proof fence 101.

[0050] Along the length direction of the energy storage device 100 (the X-axis direction in the figure), the through hole 103 is located at the edge of the lower plastic 10, and is spaced apart from the liquid inlet 102 and the explosion-proof fence 101. In this embodiment, there are two through holes 103. The two through holes 103 are respectively a first through hole 103a and a second through hole 103b. Among them, the first through hole 103a is located on the side of the liquid inlet 102 away from the explosion-proof fence 101, and the second through hole 103b is located on the side of the explosion-proof fence 101 away from the liquid inlet 102.

[0051] The opening of the avoidance groove 104 is located on the surface of the lower plastic 10 away from the cover body 20, and the avoidance groove 104 is recessed from the surface of the lower plastic 10 away from the cover body 20 toward the cover body 20. The avoidance groove 104 is arranged around the through hole 103. In this embodiment, there are two avoidance grooves 104. The two avoidance grooves 104 are respectively a first avoidance groove 104a and a second avoidance groove 104b. Specifically, the first avoidance groove 104a is arranged around the first through hole 103a and is connected to the first through hole 103a. The second avoidance groove 104b is arranged around the second through hole 103b and is connected to the second through hole 103b.

[0052] Please continue reading Figure 5 . The cover body 20 includes a first surface 21 and a second surface 22. Along the thickness direction of the cover body 20, the first surface 21 and the second surface 22 are arranged opposite to each other. Among them, the first surface 21 is the side of the cover body 20 facing the lower plastic 10, and the second surface 22 is the side of the cover body away from the lower plastic 10. The cover body 20 is also provided with an explosion-proof hole 201, a liquid injection hole 202 and an assembly hole 203. In this embodiment, the explosion-proof hole 201 passes through the first surface 21 and the second surface 22 of the cover body 20 along the thickness direction of the cover body 20 (Z-axis direction as shown in the figure). Specifically, the explosion-proof hole 201 is located in the middle part of the cover body 20. Among them, the explosion-proof hole 201 can be connected to the interior of the energy storage device 100 through the explosion-proof fence 101.

[0053] The injection hole 202 is located in the middle of the cover 20 and on one side of the explosion-proof hole 201, and is spaced apart from the explosion-proof hole 201. Specifically, the injection hole 202 penetrates the first surface 21 and the second surface 22 of the cover 20 along the thickness direction of the cover 20. The injection hole 202 is connected to the liquid inlet hole 102 of the lower plastic 10. The electrolyte can be injected into the housing 110 (such as the electrolyte) through the injection hole 202 of the cover 20 and the liquid inlet hole 102 of the lower plastic 10 in sequence. Figure 1 The receiving chamber is provided with a receiving chamber as shown in the figure, so as to realize the perfusion of the electrolyte of the energy storage device 100.

[0054] The assembly hole 203 penetrates the first surface 21 and the second surface 22 of the cover body 20 along the thickness direction of the cover body 20. Along the length direction of the energy storage device 100 (the X-axis direction shown in the figure), the assembly hole 203 is located at the edge of the cover body 20, and is spaced apart from the explosion-proof hole 201 and the injection hole 202. In this embodiment, there are two assembly holes 203. The two assembly holes 203 are respectively the first assembly hole 203a and the second assembly hole 203b. Specifically, the first assembly hole 203a is located on the side of the injection hole 202 away from the explosion-proof hole 201, and is spaced apart from the injection hole 202. The second assembly hole 203b is located on the side of the explosion-proof hole 201 away from the injection hole 202, and is spaced apart from the explosion-proof hole 201. Among them, the first assembly hole 203a is connected to the first through hole 103a, and the second assembly hole 203b is connected to the second through hole 103b.

[0055] 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 connects the inside and outside of the energy storage device 100, when the air pressure inside the energy storage device 100 is too high, the explosion-proof valve 30 will rupture 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 in turn, so as to avoid the explosion of the energy storage device 100 and improve the reliability of the use of the energy storage device 100.

[0056] See also Figure 4b , Figure 6 and Figure 7 , Figure 6 yes Figure 3 The schematic diagram of the exploded structure of the first pole unit 40 in the end cover assembly 120 is shown. Figure 7 yes Figure 6 The cross-sectional structure diagram of the first upper plastic 41 in the first pole unit 40 after being cut along BB is shown.

[0057] The first pole unit 40 includes a first upper plastic 41, a first pole 42, a first seal 43 and a first pressure ring 44. The first upper plastic 41 is provided in the first assembly hole 203a of the cover 20. Specifically, the first upper plastic 41 includes a first main body 411 and a first extension 412. The first extension 412 is fixedly connected to one end of the first main body 411. The first main body 411 is installed on the top surface of the cover 20, and the first extension 412 is provided in the first assembly hole 203a.

[0058] The first upper plastic 41 is further provided with a first matching groove 413 and a first mounting hole 414. Specifically, the opening of the first matching groove 413 is located on the surface of the first main body 411 away from the cover body 20. The first matching groove 413 is recessed from the surface of the first main body 411 away from the cover body 20 toward the cover body 20 (in the negative direction of the Z axis in the figure).

[0059] The first mounting hole 414 penetrates the first upper plastic 41 along the thickness direction of the first upper plastic 41. Specifically, the opening of the first mounting hole 414 is located at the bottom surface of the first upper plastic 41 (not shown). The first mounting hole 414 is recessed from the bottom surface of the first upper plastic 41 in the direction of the first matching groove 413 (the positive direction of the Z axis in the figure), and penetrates the groove bottom wall 413a of the first matching groove 413 to communicate with the first matching groove 413. The first mounting hole 414 is coaxial with and communicates with the first assembly hole 203a of the cover body 20.

[0060] Please refer to Figure 4b , Figure 6 and Figure 8 , Figure 8 yes Figure 6 The cross-sectional structure diagram of the first pole 42 in the first pole unit 40 after being cut along CC is shown.

[0061] In this embodiment, the first pole 42 is inserted into the first mounting hole 414 of the first upper plastic 41 and the first through hole 103a of the lower plastic 10. Exemplarily, the first pole 42 is a positive pole and is made of aluminum metal. In some other embodiments, the first pole 42 may also be a negative pole, which is not strictly limited in the embodiments of the present application.

[0062] In this embodiment, the first pole 42 includes a first pole connection surface 42a away from the cover body 20. Specifically, the first pole connection surface 42a is located on the side of the first surface 21 away from the second surface 22. Exemplarily, the first pole connection surface 42a is a circular ring surface. The first pole connection surface 42a is used for subsequent laser welding with the first pressure ring 44. Before laser welding, the first pole connection surface 42a can be processed by vibration polishing and other methods to increase the surface roughness of the first pole connection surface 42a.

[0063] The first pole 42 further includes a first flange portion 421, a first matching portion 422 and a first fixing portion 423, wherein the first matching portion 422 and the first fixing portion 423 are both located on the side of the first flange portion 421 away from the cover body 20. Specifically, the first matching portion 422 is fixedly connected to the first flange portion 421. The peripheral side surface of the first flange portion 421 is protruding relative to the peripheral side surface of the first matching portion 422.

[0064] The first fixing portion 423 is fixedly connected to the side of the first matching portion 422 away from the first flange portion 421, and the first fixing portion 423 includes a first pole connection surface 42a. The first pole connection surface 42a is located on the side of the first fixing portion 423 away from the first matching portion 422, and is arranged at the edge of the first fixing portion 423. Specifically, the first fixing portion 423 includes a first pole welding portion 4231 and a first pole mounting portion 4232 connected to each other. The first pole welding portion 4231 is arranged around the circumference of the first pole mounting portion 4232. The first pole welding portion 4231 includes a first pole connection surface 42a. In addition, the surface of the first pole mounting portion 4232 away from the first matching portion 422 can be a smooth surface or a rough surface, and the embodiments of the present application do not impose strict restrictions on this.

[0065] In addition, the peripheral side surface of the first matching portion 422 is protruding relative to the peripheral side surface of the first pole welding portion 4231 of the first fixing portion 423. The peripheral side surface of the first matching portion 422 includes a first position point (not shown). The first position point of the peripheral side surface of the first matching portion 422 refers to any point on the peripheral side surface of the first matching portion 422, and similar descriptions in the following text can be understood in the same way.

[0066] The projection of the first position point on the surface where the peripheral side surface of the first pole welding portion 4231 of the first fixing portion 423 is located is the second position point.

[0067] The distance between the second position point and the first position point is between 0.8 mm and 2.0 mm.

[0068] Specifically, the first flange portion 421 of the first pole 42 is installed in the first matching groove 413 of the first upper plastic 41, and the first matching portion 422 is penetrated in the first mounting hole 414. The first main body 411 of the first upper plastic 41 is located between the first flange portion 421 and the second surface 22 of the cover 20, and the first extension portion 412 of the first upper plastic 41 is located between the peripheral side surface of the first matching portion 422 and the hole wall surface of the first assembly hole 203a, so as to avoid the short circuit problem of the end cover assembly 120 caused by the direct contact between the first pole 42 and the cover 20. The first fixing portion 423 extends relative to the first mounting hole 414 and is located in the first avoidance groove 104a of the lower plastic 10.

[0069] Please refer to Figure 4b , Figure 6 and Fig. 9 , Fig. 9 yes Figure 6 The cross-sectional structure diagram of the first pressure ring 44 in the first pole unit 40 after being cut along DD is shown.

[0070] In this embodiment, the first pressing ring 44 is located on one side in the thickness direction of the cover body 20. Exemplarily, the first pressing ring 44 is located at the bottom of the cover body 20. Specifically, the first pressing ring 44 is installed in the first avoidance groove 104a of the lower plastic 10, and is sleeved on the first pole 42, and is welded and fixed to the first pole 42. Specifically, the first pressing ring 44 is provided with a first matching hole 441 and a first sinking groove 445. Among them, the first matching hole 441 penetrates the first pressing ring 44 along the thickness direction of the first pressing ring 44. The first matching hole 441 includes a first hole wall surface 441a. The first sinking groove 445 is arranged around the first matching hole 441 and is connected to the first matching hole 441. Specifically, the opening of the first sinking groove 445 is located on the surface of the first pressing ring 44 away from the cover body 20. The first sinking groove 445 is recessed from the surface of the first pressing ring 44 away from the cover body 20 toward the direction of the cover body 20, and penetrates the first hole wall surface 441a of the first matching hole 441.

[0071] The first pressure ring 44 also includes a first pressure ring connection surface 442 facing away from the cover body 20 and a first mounting surface 443 facing the cover body 20. Among them, the first pressure ring connection surface 442 is located on the side of the first surface 21 facing away from the second surface 22, and is connected to the first pole connection surface 42a, and is arranged around the first matching hole 441. Specifically, the first pressure ring connection surface 442 is arranged on the bottom wall of the first sink groove 445. That is, the bottom wall surface of the first sink groove 445 is the first pressure ring connection surface 442. Exemplarily, the first pressure ring connection surface 442 is a rough surface. In this embodiment, the first pressure ring connection surface 442 is composed of dot matrix pit patterns arranged in an array. In some other embodiments, the first pressure ring connection surface 442 can also be composed of any one or more patterns that can increase the surface roughness, such as a tooth-like continuous structure, a microporous structure distributed at intervals, etc.

[0072] In addition, the first pressure ring 44 also includes a first pressure ring welding portion 44a and a first pressure ring mounting portion 44b connected to each other. Among them, the first pressure ring welding portion 44a includes a first pressure ring connecting surface 442. The first pressure ring welding portion 44a is also provided with a first matching hole 441. The first pressure ring mounting portion 44b is arranged around the circumference of the first pressure ring welding portion 44a. The first pressure ring mounting portion 44b also includes a first assembly surface 446 facing away from the cover body 20. The first assembly surface 446 is arranged around the opening of the first sink groove 445. In this embodiment, the first assembly surface 446 is a smooth plane. In some other embodiments, the first assembly surface 446 may also be a rough surface, and the embodiments of the present application do not impose strict restrictions on this.

[0073] When the first pressure ring 44 is assembled with the first pole 42, the first fixing portion 423 of the first pole 42 is also inserted into the first matching hole 441. Among them, the peripheral side surface of the first fixing portion 423 is spaced apart from the first hole wall surface 441a of the first matching hole 441. The first pressure ring connecting surface 442 is arranged around the first pole connecting surface 42a of the first pole 42. Exemplarily, the first pressure ring connecting surface 442 and the first pole connecting surface 42a are located in the same plane. Thereafter, the first pressure ring 44 and the first pole 42 are fixed by laser welding. During the welding process, part of the first pole welding portion 4321 of the first pole 42 and part of the first pressure ring welding portion 44a of the first pressure ring 44 are fused to form a first weld mark 401, so that the first pole 42 and the first pressure ring 44 are connected. Among them, the first weld mark 401 includes a first outer edge 401a close to the first pole mounting portion 4232 and a first inner edge 401b disposed opposite to the first outer edge 401a, and the distance between the first inner edge 401b and the first outer edge 401a is between 0.5mm and 2.5mm. Along the thickness direction of the end cover assembly 120, the distance between the first weld mark 401 close to one end of the cover body 20 and the end of the first weld mark 401 away from the cover body 20 is between 0.4mm and 1.4mm. Exemplarily, along the thickness direction of the end cover assembly 120, the distance between the first weld mark 401 close to one end of the cover body 20 and the end of the first weld mark 401 away from the cover body 20 is between 0.6mm and 1.4mm. Under this setting, the welding reliability between the first pole 42 and the first pressure ring 44 can be ensured to be good.

[0074] In this embodiment, by setting the first pressing ring connection surface 442 of the first pressing ring 44 as a rough surface composed of dot matrix pit patterns, the roughness of the first pressing ring connection surface 442 can be increased, the first pressing ring 44 can be prevented from reflecting interference during welding, and the absorption rate of the laser light energy by the first pressing ring 44 and the first pole 42 can be improved. On the one hand, it is helpful to avoid the problem of false welding or poor welding between the first pressing ring 44 and the first pole 42, and improve the welding yield and welding stability between the first pole 42 and the first pressing ring 44. On the other hand, the welding fixation between the first pole 42 and the first pressing ring 44 can be achieved by using a laser welding device with relatively low power, which helps to save energy and reduce production costs. At the same time, it can also prevent the laser head lens of the laser welding device from being ablated by the reflected laser, and avoid damage to the laser welding device, thereby helping to extend the service life of the laser welding device.

[0075] In addition, it should be understood that when the first pole 42 and the first pressure ring 44 are laser welded, the heat of the laser will be conducted to the first upper plastic 41 through the first pole 42, and the distance between the peripheral side surface of the first matching portion 422 and the peripheral side surface of the first fixing portion 423 in the existing first pole 42 is usually 0.45 mm, resulting in the first upper plastic 41 and the first fixing portion 423 being too close, making the first upper plastic 41 very easy to melt under heat and produce black smoke, resulting in welding explosion points in the end cap assembly 120 during welding. In this embodiment, by increasing the distance between the peripheral side surface of the first matching portion 422 and the peripheral side surface of the first fixing portion 423 in the first pole 42, the first extension portion 412 of the first upper plastic 41 can be arranged away from the first fixing portion 423. When the first pressure ring 44 and the first pole 42 are welded, this arrangement can prevent the first upper plastic 41 from melting due to being too close to the first fixing portion 423, and prevent the first upper plastic 41 from producing black smoke due to melting due to being heated during the welding process, thereby avoiding the problem of welding explosion points in the end cover assembly 120 during the welding process.

[0076] Please continue reading Figure 4b and Figure 6 The first seal 43 is sleeved on the first extension portion 412 of the first upper plastic 41, and is clamped between the first mounting surface 443 of the first pressure ring 44 and the cover 20. It can be understood that the first seal 43 can not only ensure the assembly stability between the first pressure ring 44 and the cover 20, but also prevent the first pressure ring 44 from directly contacting and conducting electricity with the cover 20, thereby achieving insulation between the first pressure ring 44 and the cover 20.

[0077] See also Figure 4c , Fig.10 and Fig.11 , Fig.10 yes Figure 3 The schematic diagram of the exploded structure of the second pole unit 50 in the end cover assembly 120 is shown. Fig.11 yes Fig.10 The cross-sectional structure diagram of the second upper plastic 51 in the second pole unit 50 after being cut along EE is shown.

[0078] The second pole unit 50 includes a second upper plastic 51, a second pole 52, a second seal 53 and a second pressure ring 54. The structures of the components in the second pole unit 50, the assembly relationship between the components, and the assembly relationship between the components and the lower plastic 10 and the cover 20 can all be referred to the relevant description of the first pole unit 40 above, and will not be repeated here.

[0079] The second upper plastic 51 is passed through the second assembly hole 203b of the cover body 20. The second upper plastic 51 includes a second main body 511 and a second extension 512. The second extension 512 is fixedly connected to one end of the second main body 511. The second main body 511 is installed on the top surface of the cover body 20, and the second extension 512 is passed through the second assembly hole 203b. The second upper plastic 51 is also provided with a second matching groove 513 and a second mounting hole 514. Specifically, the opening of the second matching groove 513 is located on the surface of the second main body 511 away from the cover body 20. The second matching groove 513 is recessed from the surface of the second main body 511 away from the cover body 20 toward the direction of the cover body 20 (the negative direction of the Z axis shown in the figure).

[0080] The second mounting hole 514 penetrates the second upper plastic 51 along the thickness direction of the second upper plastic 51. Specifically, the opening of the second mounting hole 514 is located at the bottom surface of the second upper plastic 51 (not shown). The second mounting hole 514 is recessed from the bottom surface of the second upper plastic 51 in the direction of the second matching groove 513 (in the positive direction of the Z axis in the figure), and penetrates the bottom wall surface of the second matching groove 513 to communicate with the second matching groove 513. The second mounting hole 514 is coaxial with and communicates with the second assembly hole 203b of the cover body 20.

[0081] Please refer to Figure 4c , Fig.10 and Fig.12 , Fig.12 yes Fig.10 The cross-sectional structure diagram of the second pole 52 in the second pole unit 50 after being cut along FF is shown.

[0082] In this embodiment, the second pole 52 is inserted into the second mounting hole 514 and the second through hole 103b. Exemplarily, the second pole 52 is a negative pole and is made of copper metal material. In some other embodiments, the second pole 52 may also be a positive pole, which is not strictly limited in the embodiments of the present application.

[0083] In this embodiment, the second pole 52 includes a second pole connection surface 52a away from the cover body 20. Specifically, the second pole connection surface 52a is located on the side of the first surface 21 away from the second surface 22. Exemplarily, the second pole connection surface 52a is a circular ring surface. The second pole connection surface 52a is used for subsequent laser welding with the second pressure ring 54. Before laser welding, the second pole connection surface 52a can be processed by vibration polishing and other methods to increase the surface roughness of the second pole connection surface 52a.

[0084] The second pole 52 further includes a second flange portion 521, a second matching portion 522 and a second fixing portion 523, wherein the second matching portion 522 and the second fixing portion 523 are both located on the side of the second flange portion 521 facing the cover body 20. Specifically, the second matching portion 522 is fixedly connected to the second flange portion 521. The peripheral side surface of the second flange portion 521 is arranged around the peripheral side surface of the second matching portion 522, and protrudes relative to the outer peripheral side surface of the second matching portion 522.

[0085] The second fixing portion 523 is fixedly connected to the side of the second matching portion 522 away from the second flange portion 521, and the second fixing portion 523 includes a second pole connection surface 52a. The second pole connection surface 52a is located on the side of the second fixing portion 523 away from the second matching portion 522, and is arranged at the edge of the second fixing portion 523. Specifically, the second fixing portion 423 includes a second pole welding portion 5231 and a second pole mounting portion 5232 connected to each other. The second pole welding portion 5231 is arranged around the circumference of the second pole mounting portion 5232. The second pole welding portion 5231 includes a second pole connection surface 52a. In addition, the surface of the second pole mounting portion 5232 away from the second matching portion 522 can be a smooth surface or a rough surface, and the embodiments of the present application do not impose strict restrictions on this.

[0086] In addition, the peripheral side surface of the second matching portion 522 protrudes relative to the peripheral side surface of the second pole welding portion 5231 of the second fixed portion 523. Among them, the peripheral side surface of the second matching portion 522 includes a third position point (not shown). Among them, the third position point of the peripheral side surface of the second matching portion 522 refers to any point on the peripheral side surface of the second matching portion 522. The projection of the third position point on the surface where the peripheral side surface of the second pole welding portion 5231 of the second fixed portion 523 is located is the fourth position point. The distance between the fourth position point and the third position point is between 0.8 mm and 2.0 mm. Under this setting, the welding reliability between the second pole 52 and the second pressure ring 54 can be guaranteed to be good.

[0087] Specifically, the second flange portion 521 of the second pole 52 is installed in the first matching groove 413 of the second upper plastic 51, and the second matching portion 522 is penetrated in the second mounting hole 514. The second main body 511 of the second upper plastic 51 is located between the second flange portion 521 and the second surface 22 of the cover 20, and the second extension portion 512 of the second upper plastic 51 is located between the peripheral side surface of the second matching portion 522 and the hole wall surface of the second assembly hole 203b, so as to avoid the short circuit problem of the end cover assembly 120 caused by the direct contact between the second pole 52 and the cover 20. The second fixing portion 523 extends relative to the second mounting hole 514 and is located in the second avoidance groove 104b of the lower plastic 10.

[0088] Please refer to Figure 4c , Fig.10and Fig.13 , Fig.13 yes Fig.10 The cross-sectional structure diagram of the second pressure ring 54 in the second pole unit 50 after being cut along GG is shown.

[0089] In this embodiment, the second pressure ring 54 is located on one side in the thickness direction of the cover body 20. Exemplarily, the second pressure ring 54 is located at the bottom of the cover body 20. Along the length direction of the end cover assembly 120, the second pressure ring 54 is spaced apart from the first pressure ring 44. Specifically, the second pressure ring 54 is installed in the second avoidance groove 104b of the lower plastic 10, and is sleeved on the second pole 52, and is welded and fixed to the second pole 52. Specifically, the second pressure ring 54 is provided with a second matching hole 541 and a second sink groove 545. Among them, the second matching hole 541 passes through the second pressure ring 54 along the thickness direction of the second pressure ring 54. Among them, the second matching hole 541 includes a second hole wall surface 541a. The second sink groove 545 is arranged around the second matching hole 541 and is connected to the second matching hole 541. Specifically, the opening of the second sink groove 545 is located on the surface of the second pressure ring 54 away from the cover body 20. The second recessed groove 545 is recessed from the surface of the second pressing ring 54 away from the cover body 20 toward the cover body 20 , and penetrates the second hole wall surface 541 a of the second matching hole 541 .

[0090] The second pressure ring 54 also includes a second pressure ring connection surface 542 facing away from the cover body 20 and a second mounting surface 543 facing the cover body 20. Among them, the second pressure ring connection surface 542 is located on the side of the first surface 21 facing away from the second surface 22, and is connected to the second pole connection surface 52a, and is arranged around the second matching hole 541 and the second pole connection surface 52a. Specifically, the second pressure ring connection surface 542 is arranged on the bottom wall of the second sink groove 545. That is, the bottom wall surface of the second sink groove 545 is the second pressure ring connection surface 542. Exemplarily, the second pressure ring connection surface 542 is a rough surface. In this embodiment, the second pressure ring connection surface 542 is composed of dot matrix pit patterns arranged in an array. In some other embodiments, the second pressure ring connection surface 542 can also be composed of any one or more patterns that can increase the surface roughness, such as a tooth-like continuous structure, a microporous structure distributed at intervals, etc.

[0091] In addition, the second pressure ring 54 also includes a second pressure ring welding portion 54a and a second pressure ring mounting portion 54b connected to each other. Among them, the second pressure ring welding portion 54a includes a second pressure ring connecting surface 542. The second pressure ring welding portion 54a is also provided with a second matching hole 541. The second pressure ring mounting portion 54b is arranged around the circumference of the second pressure ring welding portion 54a. The second pressure ring mounting portion 54b also includes a second assembly surface 546 facing away from the cover body 20. The second assembly surface 546 is arranged around the opening of the second sink groove 545. In this embodiment, the second assembly surface 546 is a smooth plane. In some other embodiments, the second assembly surface 546 may also be a rough surface, and the embodiments of the present application do not impose strict restrictions on this.

[0092] When the second pressure ring 54 is assembled with the second pole 52, the second fixing portion 523 of the second pole 52 is inserted into the second matching hole 541. Among them, the peripheral side surface of the second fixing portion 523 is spaced apart from the second hole wall surface 541a of the second matching hole 541. The second pressure ring connecting surface 542 is arranged around the second pole connecting surface 52a of the second pole 52. Exemplarily, the second pressure ring connecting surface 542 and the second pole connecting surface 52a are located in the same plane. Thereafter, the second pressure ring 54 and the second pole 52 are fixed by laser welding. During the welding process, part of the second pole welding portion 5231 of the second pole 52 and part of the second pressure ring welding portion 54a of the second pressure ring 54 are fused to form a second weld mark 501, so that the second pole 52 and the second pressure ring 54 are connected. The second weld mark 501 includes a second outer edge 501a close to the second pole mounting portion 5232 and a second inner edge 501b disposed opposite to the second outer edge 501a, and the distance between the second inner edge 501b and the second outer edge 501a is between 0.5 mm and 2.5 mm. Along the thickness direction of the end cap assembly 120, the distance between the end of the second weld mark 501 close to the cover body 20 and the end of the second weld mark 501 away from the cover body 20 is between 0.4 mm and 1.4 mm. Exemplarily, along the thickness direction of the end cap assembly 120, the distance between the end of the second weld mark 501 close to the cover body 20 and the end of the second weld mark 501 away from the cover body 20 is between 0.4 mm and 1.1 mm.

[0093] It can be understood that the second pole 52 is made of copper metal material, and the mechanical strength of the second pole 52 is greater than the mechanical strength of the first pole 42 which is made of aluminum metal material. By making the second weld mark depth smaller than the first weld mark depth, the structural strengths of the first pole 42 and the second pole 52 are basically the same, thereby ensuring that the first pole 42 and the second pole 52 both have sufficiently large thrust or torque.

[0094] In this embodiment, by setting the second pole connecting surface 52a of the second pressure ring 54 as a rough surface composed of dot matrix pit patterns, the roughness of the second pressure ring connecting surface 542 can be increased, the reflection interference of the second pressure ring 54 during the welding process can be avoided, and the absorption rate of the laser light energy by the second pressure ring 54 and the second pole 52 can be improved. On the one hand, it is helpful to avoid the problem of false welding or poor welding between the second pressure ring 54 and the second pole 52, and improve the welding yield and welding stability between the second pole 52 and the second pressure ring 54. On the other hand, the welding fixation between the second pole 52 and the second pressure ring 54 can be achieved by using a laser welding device with relatively low power, which helps to save energy and reduce production costs. At the same time, it can also avoid the laser head lens of the laser welding device from being ablated by the reflected laser, and avoid damage to the laser welding device, thereby helping to extend the service life of the laser welding device.

[0095] In addition, it should be understood that when the second pole 52 and the second pressure ring 54 are laser welded, the heat of the laser will be conducted to the second upper plastic 51 through the second pole 52, and the distance between the peripheral side surface of the second matching portion 522 and the peripheral side surface of the second fixing portion 523 in the existing second pole 52 is usually 0.45 mm, resulting in the second upper plastic 51 and the second fixing portion 523 being too close, making the second upper plastic 51 very easy to melt under heat and produce black smoke, resulting in welding explosion points in the end cap assembly 120 during welding. In this embodiment, by increasing the distance between the peripheral side surface of the second matching portion 522 and the peripheral side surface of the second fixing portion 523 in the second pole 52, the second extension portion 512 of the second upper plastic 51 can be arranged away from the second fixed portion. When the second pressure ring 54 and the second pole 52 are welded, this arrangement can prevent the second upper plastic 51 from melting due to being too close to the first fixing portion 423, and prevent the second upper plastic 51 from producing black smoke due to melting due to heat during the welding process, thereby avoiding the problem of welding explosion points in the end cover assembly 120 during the welding process.

[0096] Please continue reading Figure 4c and Fig.10 The second seal 53 is sleeved on the second extension portion 512 of the second upper plastic 51, and is clamped between the second mounting surface 543 of the second pressure ring 54 and the cover 20. It can be understood that the second seal 53 can not only ensure the assembly stability between the second pressure ring 54 and the cover 20, but also prevent the second pressure ring 54 from directly contacting and conducting electricity with the cover 20, thereby achieving insulation between the second pressure ring 54 and the cover 20.

[0097] Please refer to Fig.14 , Fig.15a , Fig.15b and Fig.15c , Fig.14 yes Figure 1The schematic diagram of the structure of the end cover assembly 120 in the energy storage device 100 in the second embodiment is shown. Fig.15a yes Fig.14 The cross-sectional structure diagram of the end cover assembly 120 after being cut along HH is shown. Fig.15b yes Fig.15a The enlarged schematic diagram of the middle c area, Fig.15c yes Fig.15a Enlarged schematic diagram of area d in the middle.

[0098] The end cap assembly 120 shown in this embodiment is different from the end cap assembly 120 shown in the first embodiment described above in that the first pole connection surface 42a of the first pole 42 is also a rough surface. That is, the first pole connection surface 42a and the first pressure ring connection surface 442 are both rough surfaces. Exemplarily, the first pole connection surface 42a is composed of dot matrix pit patterns arranged in an array.

[0099] In this embodiment, the peripheral side surface of the first pole mounting portion 4232 is spaced apart from the hole wall surface 441a of the first matching hole 441. The first pole welding portion 4231 fills the gap between the first hole wall surface 441a of the first matching hole 441 and the peripheral side surface of the first pole mounting portion 4232.

[0100] Specifically, when the first pole 42 is assembled with the first pressure ring 44, the first pole 42 and the first pressure ring 44 are first fixed by a riveting process, and then the first pole 42 and the first pressure ring 44 are fixedly connected by a welding process. Among them, the dot matrix pit pattern on the connecting surface 42a of the first pole is formed during the riveting process. Specifically, before riveting, the first pole 42 includes an assembly portion (not shown) fixedly connected to the end of the first matching portion 422 away from the first flange portion 421. The assembly portion is penetrated through the first matching hole 441 of the first pressure ring 44, and the peripheral side surface of the assembly portion is spaced apart from the hole wall surface 441a of the first matching hole 441. Among them, the diameter of the assembly portion is smaller than the aperture of the first matching hole 441. Exemplarily, the difference between the diameter of the assembly part and the aperture of the first matching hole 441 is 0.1 mm, the tolerance between the diameter of the assembly part and the aperture of the first matching hole 441 is ±0.05 mm, and the bilateral clearance between the circumferential side surface of the assembly part and the hole wall surface of the first matching hole 441 is between 0.03 mm and 0.17 mm, so as to facilitate the assembly of the assembly part and the first pressure ring 44.

[0101] During the riveting process, the outer edge of the assembly portion is deformed by external force to form the first pole welding portion 4231, and fills the gap between the first hole wall 441a of the first matching hole 441 and the peripheral side surface of the first pole mounting portion 4232, so that the first pole 42 and the first pressing ring 44 are riveted and fixed. At the same time, the central part of the assembly portion of the first pole 42 forms the first pole mounting portion 4232. In this process, a dot matrix pit pattern arranged in an array is formed on the first pole connection surface 42a of the first pole welding portion 4231 to increase the roughness of the first pole connection surface 42a, so that the first pole connection surface 42a becomes a rough surface.

[0102] It can be understood that the first pole welding portion 4231 formed by riveting can fill the gap between the first hole wall 441a and the peripheral side surface of the first pole mounting portion 4232, so that the welding laser cannot pass through the assembly gap between the first pole 42 and the first pressure ring 44, thereby avoiding the first upper plastic 41 from melting due to heat and generating black smoke, and further avoiding the problem of welding explosion points in the end cover assembly during the welding process.

[0103] In this embodiment, by setting the first pole connection surface 42a and the first pressure ring connection surface 442 to rough surfaces, on the one hand, it is possible to avoid the first pole 42 and the first pressure ring 44 from reflecting interference during the welding process, further improve the absorption rate of the laser light energy by the first pole 42 and the first pressure ring 44, thereby further improving the welding yield and welding stability between the first pole 42 and the first pressure ring 44. On the other hand, it is also possible to increase the welding window for laser welding of the first pole 42 and the first pressure ring 44, which is convenient for welding the first pole 42 and the first pressure ring 44, and can also increase the width of the weld mark, thereby also helping to improve the welding stability between the first pole 42 and the second pole 52.

[0104] In this embodiment, the structure of the second pole 52 is the same as that of the first pole 42 described above. Among them, the second pole connection surface 52a of the second pole 52. The second pole connection surface 52a is a rough surface composed of dot matrix pit patterns arranged in an array. In this embodiment, the relevant descriptions of the second pole welding portion 5231, the second pole mounting portion 5232 and the second pole connection surface 52a in the second pole 52 can all refer to the relevant descriptions of the first pole 42 described above. The structure of the second pressure ring 54 is the same as that of the first pressure ring 44 described above, and the assembly relationship and assembly method between the second pressure ring 54 and the second pole 52 can all refer to the relevant descriptions of the assembly relationship and assembly method between the first pressure ring 44 and the first pole 42 described above, and will not be repeated here.

[0105] Please refer to Fig.16a , Fig.16b , Fig.16c and Fig.17 , Fig.16a yes Figure 1 FIG. 1 is a schematic cross-sectional view of the end cover assembly 120 of the energy storage device 100 in the third embodiment. Fig.16b yes Fig.16a The enlarged schematic diagram of the middle e area, Fig.16c yes Fig.16a The enlarged schematic diagram of the f region in the middle, Fig.17 yes Fig.16c Schematic diagram of the enlarged area I in the middle.

[0106] The end cap assembly 120 shown in this embodiment is different from the end cap assembly 120 shown in the first embodiment described above in that the fixing portion 423 of the first pole 42 is transitionally matched with the first matching hole 441 of the first pressure ring 44. That is, the diameter of the first matching portion 422 of the first pole 42 is the same as the aperture of the first matching hole 441. When the first pole 42 and the first pressure ring 44 are assembled, the peripheral side surface of the first matching portion 422 of the first pole 42 abuts against the first hole wall surface 441a of the first matching hole 441. Under this setting, the bilateral clearance between the peripheral side surface of the first matching portion 422 and the first hole wall surface 441a of the first matching hole 441 is greater than or equal to 0, and less than 0.1 mm.

[0107] Under this setting, the assembly gap between the first pole 42 and the first pressure ring 44 can be reduced or eliminated, so that the laser cannot pass through the assembly gap between the first pole 42 and the first pressure ring 44, thereby avoiding the first upper plastic 41 from melting due to heat and generating black smoke, avoiding the problem of welding explosion points in the end cover assembly during the welding process, thereby helping to improve the welding yield and welding stability between the first pole 42 and the first pressure ring 44.

[0108] It should be noted that in the actual production process, the bilateral clearance between the circumferential side surface of the first fixing portion 423 and the first hole wall surface 441a of the first matching hole 441 is usually ±0.07 mm, so as to ensure that the first pressure ring 44 can be smoothly pressed into the first pole 42 using a press, thereby realizing the assembly between the first pole 42 and the first pressure ring 44.

[0109] In this embodiment, the first pressure ring 44 also includes a first guide surface 444. The first guide surface 444 is fixedly connected between the first hole wall surface 441a of the first matching hole 441 and the first mounting surface 443. In this embodiment, the first guide surface 444 can be a beveled chamfered surface or a circular arc chamfered surface, and the embodiments of the present application do not impose strict restrictions on this. Among them, the first guide surface 444 includes a first point on the side close to the first mounting surface 443 (not shown in the figure) and a second point on the side close to the first hole wall surface 441a (not shown in the figure). It should be noted that the first point is any point on the side of the first guide surface 444 close to the first mounting surface 443, and the second point is any point on the side of the first guide surface 444 close to the first hole wall surface 441a. The following similar descriptions can be understood in the same way.

[0110] In this embodiment, the projection of the first point on the surface where the first hole wall surface 441a is located is the first projection point (not shown). The projection of the second point on the surface where the first mounting surface 443 is located is the second projection point (not shown). The ratio of the distance a between the first point and the first projection point to the distance b between the second point and the second projection point is 0.5≤a / b≤1.

[0111] It can be understood that by providing the first guide surface 444 on the first pressure ring 44, when the first pressure ring 44 is assembled with the first pole 42, on the one hand, the first guide surface 444 can play a guiding role to ensure that the first pressure ring 44 can be smoothly sleeved on the first pole 42 to achieve the assembly between the first pole 42 and the first pressure ring 44, and on the other hand, it can also prevent the first pressure ring 44 from scratching the first pole 42 during the assembly process.

[0112] In this embodiment, the structure of the second pole 52 is the same as that of the first pole 42, and the structure of the second pressure ring 54 is the same as that of the first pressure ring 44. The assembly relationship between the second pole 52 and the second pressure ring 54 can refer to the relevant description of the assembly relationship and assembly method between the first pole 42 and the first pressure ring 44, which will not be repeated here. Among them, the second pressure ring 54 also includes a second guide surface 544. The positional relationship of the second guide surface 544 in the second pressure ring 54 can refer to the relevant description of the positional relationship of the first guide surface 443 in the first pressure ring 44, which will not be repeated here.

[0113] The present application also provides an electric device, which includes the energy storage device 100, and the energy storage device 100 supplies power to the electric device. The electric device may be a new energy vehicle, a power storage station, a server, or other equipment that requires electricity.

[0114] The above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application; in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An end cap assembly for an energy storage device, characterized in that: The invention comprises a cover body, a pressure ring and a pole, 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, and the assembly hole passes through the first surface and the second surface along the thickness direction of the cover body, the pressure ring is located on one side of the thickness direction of the cover body, the pressure ring is provided with a matching hole, and the matching hole passes through the pressure ring along the thickness direction of the pressure ring and is connected with the matching hole, the pole is passed through the assembly hole and the matching hole, and is fixed to the pressure ring by welding; In which, the pole includes a pole connection surface facing away from the cover body, and the pole connection surface is located on the side of the first surface facing away from the second surface. The pressure ring includes a pressure ring connection surface facing away from the cover body, and the pressure ring connection surface is located on the side of the first surface facing away from the second surface, and is connected to the pole connection surface and arranged around the pole connection surface. At least one of the pole connection surface and the pressure ring connection surface is a rough surface.

2. The end cap assembly according to claim 1, wherein: The pole includes a fixing portion and a matching portion, the fixing portion is installed in the matching hole, and the fixing portion includes the pole connecting surface; The matching portion is fixedly connected to one side of the fixing portion and installed in the assembly hole, and the peripheral side surface of the matching portion is protruding relative to the peripheral side surface of the fixing portion; The end cover assembly further includes an upper plastic, which is passed through the assembly hole and is located between the peripheral side surface of the matching portion and the hole wall surface of the assembly hole.

3. The end cap assembly according to claim 2, wherein: The peripheral side surface of the mating portion includes a first position point, the projection of the first position point on the surface where the peripheral side surface of the fixing portion is located is a second position point, and the distance between the second position point and the first position point is between 0.8 mm and 2.0 mm.

4. The end cap assembly according to claim 2 or 3, characterized in that: The fixing portion includes a pole mounting portion and a pole welding portion connected to each other, the pole welding portion is arranged around the circumference of the pole mounting portion, and the pole welding portion includes the pole connecting surface; The pressure ring includes a pressure ring mounting portion and a pressure ring welding portion connected to each other, the pressure ring mounting portion is arranged around the circumference of the pressure ring welding portion, and the pressure ring welding portion includes the pressure ring connecting surface; When the pole is welded and fixed to the pressure ring, part of the pole welding portion and part of the pressure ring welding portion are fused to form a weld mark, and the weld mark includes an outer edge away from the pole mounting portion and an inner edge arranged opposite to the outer edge, and the distance between the inner edge and the outer edge is between 0.5 mm and 2.5 mm.

5. The end cap assembly according to claim 4, wherein: Along the thickness direction of the end cover assembly, the distance between the end of the weld mark close to the cover body and the end of the weld mark away from the cover body is between 0.4 mm and 1.4 mm.

6. The end cap assembly according to claim 2, wherein: The peripheral side surface of the pole mounting portion is spaced apart from the hole wall surface of the matching hole, and the pole welding portion fills the gap between the hole wall surface of the matching hole and the peripheral side surface of the pole mounting portion.

7. The end cap assembly according to claim 2, wherein: The fixing portion is transitionally matched with the matching hole.

8. The end cap assembly according to claim 7, wherein: The pressure ring further includes a mounting surface and a guide surface. Along the thickness direction of the pressure ring, the mounting surface and the pressure ring connection surface are arranged opposite to each other, and the guide surface is fixedly connected between the mounting surface and the hole wall surface of the matching hole.

9. The end cap assembly according to claim 8, wherein: The guide surface includes a first point on a side close to the mounting surface and a second point on a side close to the hole wall of the matching hole, wherein the projection of the first point on the surface where the hole wall of the matching hole is located is a first projection point, and the projection of the second point on the surface where the mounting surface is located is a second projection point; The ratio of a distance between the first point and the first projection point to a distance between the second point and the second projection point is 0.5≤a / b≤1.

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: The energy storage device according to claim 10 is provided to supply power to the electrical equipment.

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