End cover assembly, energy storage device and electrical equipment

Abstract

The present application provides an end cover assembly, an energy storage device and an electrical device, which can make the energy storage device exhaust smoothly, and is conducive to improving the safety of the energy storage device. The end cover assembly includes a cover plate, an explosion-proof valve and a current collecting plate, the cover plate includes a first surface and a second surface arranged opposite to each other, the cover plate is provided with a mounting hole and an explosion-proof hole arranged at intervals, the cover plate is also provided with a plurality of spaced limiting protrusions, the plurality of limiting protrusions are arranged on the first surface, and are spaced from the mounting holes and the explosion-proof holes, the explosion-proof valve is installed on the cover plate, and covers the explosion-proof holes; the current collecting plate includes a main body, a first step portion and a second step portion, the main body is located on the side of the first surface away from the second surface, and is arranged opposite to the plurality of limiting protrusions, the main body is provided with a through hole arranged opposite to the explosion-proof valve, the through hole is staggered with the plurality of limiting protrusions, the first step portion is arranged on the first surface of the main body, the first step portion abuts against the first surface, and the second step portion is penetrated through the mounting hole.

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] Energy storage devices such as secondary batteries are widely used as the main power source for electrical equipment due to their recyclable characteristics. As the demand for energy storage devices gradually increases, people's performance requirements for them in various aspects are also getting higher and higher. In existing energy storage devices, the exhaust channel between the collector plate and the cover plate is narrow, which makes the exhaust of the energy storage device not smooth, and the gas inside the energy storage device cannot smoothly impact the explosion-proof valve, resulting in the explosion-proof valve being unable to open the valve in time to release pressure when thermal runaway occurs in the energy storage device, reducing the safety of the energy storage device. Summary of the invention

[0003] The present application provides an end cover assembly, an energy storage device, and electrical equipment, which can ensure smooth exhaust of the energy storage device and ensure that the gas inside the energy storage device can smoothly impact the explosion-proof valve, so as to ensure that the explosion-proof valve can open the valve and release pressure in time when thermal runaway occurs in the energy storage device, thereby helping to improve the safety of the energy storage device.

[0004] In a first aspect, the present application provides an end cap assembly for an energy storage device. The end cap assembly includes a cover plate, an explosion-proof valve, and a current collecting plate. The cover plate includes a first surface and a second surface. Along the thickness direction of the cover plate, the first surface and the second surface are arranged opposite to each other. The cover plate is provided with a mounting hole and an explosion-proof hole. Both the mounting hole and the explosion-proof hole penetrate the first surface and the second surface along the thickness direction of the cover plate and are arranged at intervals from each other. The cover plate is also provided with a first limiting protrusion, a second limiting protrusion, a third limiting protrusion, and a fourth limiting protrusion. The first limiting protrusion, the second limiting protrusion, the third limiting protrusion, and the fourth limiting protrusion are all arranged on the first surface and are in contact with the The mounting hole and the explosion-proof hole are arranged at intervals, the first limiting protrusion and the second limiting protrusion are respectively located on two opposite sides of the explosion-proof hole, the third limiting protrusion and the fourth limiting protrusion are respectively located on two opposite sides of the explosion-proof hole, and are arranged at intervals from the first limiting protrusion and the second limiting protrusion, and are located on the side of the first limiting protrusion and the second limiting protrusion facing the mounting hole; the explosion-proof valve is installed on the cover plate and covers the explosion-proof hole, the explosion-proof valve has a center line, the center line is parallel to the length direction of the explosion-proof valve, and passes through the first limiting protrusion and the second limiting protrusion, the explosion-proof valve The explosion-proof valve further comprises a notched portion and a connecting portion, the notched portion comprises a first end point and a second end point, the first end point and the second end point are arranged at intervals, the connecting portion is fixedly connected between the first end point and the second end point, and is located on a side of the explosion-proof valve away from the mounting hole; the collecting plate comprises a main body portion, a first step portion and a second step portion, the main body portion is located on a side of the first surface away from the second surface, and is arranged opposite to the first limiting protrusion, the second limiting protrusion, the third limiting protrusion and the fourth limiting protrusion, the main body portion comprises a first surface and a second surface, and along the thickness direction of the main body portion , the first surface and the second surface are arranged opposite to each other, the main body is provided with a through hole, the through hole penetrates the first surface and the second surface along the thickness direction of the main body, and is arranged opposite to the explosion-proof valve, and is staggered with the limiting protrusion, the first step portion is arranged on the first surface, the surface of the first step portion facing away from the main body is in contact with the first surface, and the height of the first step portion is greater than the height of the first limiting protrusion, the second limiting protrusion, the third limiting protrusion and the fourth limiting protrusion, the second step portion is fixedly connected to the surface of the first step portion facing away from the main body, and is penetrated by the mounting hole.

[0005] Among them, there is a first connecting line between the center of the first limiting protrusion and the center of the mounting hole, there is a second connecting line between the center of the second limiting protrusion and the center of the mounting hole, there is a third connecting line between the center of the third limiting protrusion and the center of the mounting hole, there is a fourth connecting line between the center of the fourth limiting protrusion and the center of the mounting hole, and the angle α between the first connecting line and the second connecting line is smaller than the angle β between the third connecting line and the fourth connecting line.

[0006] Wherein, the third limiting protrusion and the fourth limiting protrusion are located on a straight line where the edge of the explosion-proof hole close to the explosion-proof valve is located.

[0007] In which, the cover plate is also provided with a first groove, a second groove, a third groove and a fourth groove, the openings of the first groove, the second groove, the third groove and the fourth groove are all located on the second surface, the first groove, the second groove, the third groove and the fourth groove are spaced apart from each other, and are spaced apart from the mounting hole and the explosion-proof hole, along the thickness direction of the cover plate, the first groove is arranged opposite to the first limiting protrusion, the second groove is arranged opposite to the second limiting protrusion, the third groove is arranged opposite to the third limiting protrusion, and the fourth groove is arranged opposite to the fourth limiting protrusion.

[0008] Among them, the main body is also provided with a welding groove, the opening of the welding groove is located on the first surface, the welding groove is spaced apart from the through hole, and along the thickness direction of the end cover assembly, the welding groove and the first limiting protrusion, the second limiting protrusion, the third limiting protrusion, the fourth limiting protrusion and the explosion-proof valve are all staggered.

[0009] There are multiple through holes and multiple welding grooves, and the multiple welding grooves are arranged around the center of the main body at intervals, and at least one through hole is provided between two adjacent welding grooves; along the thickness direction of the end cover assembly, the first limiting protrusion, the second limiting protrusion, the third limiting protrusion, the fourth limiting protrusion and the projection of the explosion-proof valve on the main body are all located between two adjacent welding grooves.

[0010] Among them, the welding groove includes a groove bottom wall and a first groove side wall close to the first step portion, and the first groove side wall is fixedly connected to the groove bottom wall; the main body is also provided with a stress release hole, and along the thickness direction of the main body, the stress release hole penetrates the main body and the first groove side wall.

[0011] Among them, the welding groove also includes two second groove side walls, and the two second groove side walls are fixedly connected to the groove bottom wall. Along the width direction of the welding groove, the two second groove side walls are respectively connected to the opposite sides of the first groove side wall; along the thickness direction of the main body, the stress release hole also penetrates the second groove side wall.

[0012] There are a plurality of stress release holes, and every two of the stress release holes penetrate through one of the first groove side walls of the welding groove, and penetrate through one of the second groove side walls respectively.

[0013] In a second aspect, the present application also provides an energy storage device, comprising a shell, an electrode assembly and an end cover assembly as described in any one of the above items, wherein the shell is provided with an opening and a receiving cavity, the electrode assembly is received in the receiving cavity, the end cover assembly closes the opening, and the collecting plate is electrically connected to the electrode assembly.

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

[0015] In the end cover assembly provided in the present application, a first limiting protrusion, a second limiting protrusion, a third limiting protrusion and a fourth limiting protrusion are arranged on the cover plate, and the first limiting protrusion, the second limiting protrusion, the third limiting protrusion and the fourth limiting protrusion are arranged relative to the main body of the collecting plate. When the gas inside the energy storage device impacts the collecting plate, the first limiting protrusion, the second limiting protrusion, the third limiting protrusion and the fourth limiting protrusion can abut against the main body to limit the collecting plate and restrict the movement of the collecting plate toward the cover plate, so as to avoid the exhaust channel between the cover plate and the main body of the collecting plate from being blocked due to the movement of the collecting plate toward the cover plate, thereby enabling smooth exhaust of the energy storage device and ensuring that the explosion-proof valve can open the valve in time to release pressure when thermal runaway occurs in the energy storage device, which is beneficial to improving the safety of the energy storage device and improving the reliability of the use of the energy storage device. 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 A schematic diagram of the structure of the end cover assembly in the energy storage device shown;

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

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

[0021] Figure 5 yes Figure 3 A schematic diagram of the structure of the cover plate in the end cover assembly shown;

[0022] Figure 6 yes Figure 5 The structural schematic diagram of the cover plate shown at another angle;

[0023] Figure 7 yes Figure 5 The cross-sectional structure diagram of the cover plate after being cut along BB is shown;

[0024] Figure 8 yes Figure 3 A schematic diagram of the structure of the explosion-proof valve in the end cover assembly shown;

[0025] Fig. 9 yes Figure 6 The schematic diagram of the structure after the cover plate and the explosion-proof valve are assembled;

[0026] Fig.10 yes Figure 3 A schematic diagram of the structure of the current collecting plate in the end cover assembly shown;

[0027] Fig.11 yes Fig.10 The cross-sectional structure diagram of the current collecting plate after being cut along CC is shown.

[0028] The names corresponding to the reference numerals in the figures are:

[0029] Energy storage device 100, housing 110, end cover assembly 120, cover plate 10, current collecting plate 20, explosion-proof valve 30, protective member 40, first surface 11, second surface 12, mounting hole 14, explosion-proof hole 15, mounting sink 16, first assembly sink 17, second assembly sink 18, groove 19, first sub-hole 141, second sub-hole 142, first groove 19a, second groove 19b, third groove 19c, fourth groove 19d, limiting protrusion 13, first limiting protrusion 13a, second limiting protrusion 13b, third limiting protrusion 13c, fourth limiting protrusion 13d, first connecting line 101, second connecting line 102, Wiring 102, third connecting line 103, fourth connecting line 104, center line 301, notched portion 31, connecting portion 32, welding portion 33, first bursting portion 34, second bursting portion 35, first endpoint 311, second endpoint 312, main body 21, boss portion 22, first surface 211, second surface 212, first step portion 221, second step portion 222, first sub-portion 222a, second sub-portion 222b, welding groove 23, through hole 24, injection hole 25, stress release hole 26, groove bottom wall 231, first groove side wall 232, second groove side wall 233, step portion 251, injection portion 252. DETAILED DESCRIPTION

[0030] 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.

[0031] See also Figure 1 , Figure 1 It is a schematic diagram of the structure of the energy storage device 100 provided in an embodiment of the present application.

[0032] In this embodiment, the energy storage device 100 is a cylindrical battery. The energy storage device 100 includes a shell 110, an end cap assembly 120 and an electrode assembly (not shown). Exemplarily, the shell 110 can be made of aluminum. Among them, the shell 110 is cylindrical. The shell 110 has an opening (not shown) and a receiving cavity (not shown). The electrode assembly is received in the receiving cavity. Exemplarily, the electrode assembly is a wound electrode assembly. Among them, the electrode assembly includes a battery cell (not shown) and a pole ear (not shown). The pole ear is fixedly connected to the battery cell. The receiving cavity is also used to receive an electrolyte, and the electrode assembly is immersed in the electrolyte. The end cap assembly 120 is installed on one side of the shell 110 in the height direction and closes the opening. In some other embodiments, the energy storage device 100 can also be a square battery or other components with power storage function.

[0033] Please refer to Figure 2 , Figure 3 and Figure 4 , Figure 2 yes Figure 1 The schematic diagram of the structure of the end cover assembly 120 in the energy storage device 100 is shown. Figure 3 yes Figure 2 The exploded structural diagram of the end cap assembly 120 is shown in FIG. Figure 4 yes Figure 2 The cross-sectional structure diagram of the end cap assembly 120 after being cut along AA is shown. Wherein, "cut along AA" means cutting along the plane where the AA line is located.

[0034] The end cap assembly 120 includes a cover plate 10, a current collecting plate 20, an explosion-proof valve 30 and a protective member 40. The current collecting plate 20 is installed on the inner side of the housing 110 and is electrically connected to the pole tab of the battery cell. Exemplarily, the current collecting plate 20 can be electrically connected to the pole tab of the electrode assembly by welding. The cover plate 10 is installed on one side of the current collecting plate 20 in the thickness direction. The explosion-proof valve 30 and the protective member 40 are both installed on the cover plate 10, and are both spaced apart from the current collecting plate 20. Along the thickness direction of the end cap assembly 120, the protective member 40 and the explosion-proof valve 30 are arranged opposite to each other and cover the explosion-proof valve 30. The protective member 40 is used to protect the explosion-proof valve 30 to prevent the external environment and external forces from damaging the explosion-proof valve 30, thereby preventing the explosion-proof valve 30 from being accidentally touched, and ensuring the good reliability of the energy storage device 100.

[0035] It should be noted that the directional words such as "outside" and "inside" involved in this application are all Figure 1 The energy storage device 100 is described in terms of its orientation, with the outer side of the housing 110 being referred to as “outside”, and the inner side of the housing 110 being referred to as “inside”, and similar descriptions hereinafter may be understood in the same manner.

[0036] Please refer to Figure 4 and Figure 5 , Figure 5 yes Figure 3 A schematic structural diagram of the cover plate 10 in the end cover assembly 120 is shown.

[0037] In this embodiment, the cover plate 10 is roughly disc-shaped. The cover plate 10 includes a first surface 11 and a second surface 12. The first surface 11 and the second surface 12 are arranged opposite to each other along the thickness direction of the cover plate 10. Specifically, the first surface 11 is a side of the cover plate 10 facing the housing 110, and the second surface 12 is a side of the cover plate 10 facing away from the housing 110.

[0038] The cover plate 10 is also provided with a mounting hole 14, an explosion-proof hole 15, a mounting groove 16, a first assembly groove 17, a second assembly groove 18 and a groove 19. Among them, the mounting hole 14 and the explosion-proof hole 15 both penetrate the first surface 11 and the second surface 12 of the cover plate 10 along the thickness direction of the cover plate 10, and are arranged at intervals from each other. Among them, the mounting hole 14 is arranged in the middle area of ​​the cover plate 10, and is used to install the collecting plate 20. Exemplarily, the mounting hole 14 is a circular hole. The central axis of the mounting hole 14 is coaxial with the central axis of the cover plate 10. Specifically, the mounting hole 14 includes a first sub-hole 141 and a second sub-hole 142. The first sub-hole 141 is connected to one side of the second sub-hole 142 and is connected to the second sub-hole 142. Along the direction of the collecting plate 20 to the cover plate 10, the aperture of the first sub-hole 141 gradually decreases. In this embodiment, the explosion-proof hole 15 is a waist-shaped hole. Exemplarily, the extension direction of the explosion-proof hole 15 is perpendicular to the radial direction of the cover plate 10.

[0039] The first assembly groove 17 and the second assembly groove 18 are both arranged around the explosion-proof hole 15, and are both connected to the explosion-proof hole 15. Along the thickness direction of the cover plate 10, the first assembly groove 17 and the second assembly groove 18 are arranged back to back. Specifically, the opening of the first assembly groove 17 is located on the first surface 11. The first assembly groove 17 is recessed from the first surface 11 to the direction of the second surface 12, and passes through the hole wall of the explosion-proof hole 15 to be connected to the explosion-proof hole 15. The first assembly groove 17 is used to install the explosion-proof valve 30. The opening of the second assembly groove 18 is located on the second surface 12. The second assembly groove 18 is recessed from the second surface 12 to the direction of the first surface 11, and passes through the hole wall of the explosion-proof hole 15 to be connected to the explosion-proof hole 15. The second assembly groove 18 is used to install the protective member 40.

[0040] The opening of the installation groove 16 and the opening of the groove 19 are both located on the second surface 12, and the installation groove 16 and the groove 19 are both recessed from the second surface 12 to the first surface 11. Specifically, the installation groove 16 is arranged around the installation hole 14 and penetrates the hole wall of the installation hole 14 to communicate with the installation hole 14. That is, the installation groove 16 is spaced apart from the explosion-proof hole 15, the first assembly groove 17, and the second assembly groove 18.

[0041] In this embodiment, the groove 19 is spaced apart from the mounting groove 16, the mounting hole 14, the explosion-proof hole 15, the first assembly groove 17, and the second assembly groove 18. Exemplarily, there are multiple grooves 19. The multiple grooves 19 are spaced apart from each other and are spaced around the explosion-proof hole 15. The multiple grooves 19 may include a first groove 19a, a second groove 19b, a third groove 19c, and a fourth groove 19d. The openings of the first groove 19a, the second groove 19b, the third groove 19c, and the fourth groove 19d are all located on the second surface 12. The first groove 19a, the second groove 19b, the third groove 19c, and the fourth groove 19d are spaced apart from each other and are spaced apart from the mounting hole 14 and the explosion-proof hole 15.

[0042] Please refer to Figure 4 , Figure 6 and Figure 7 , Figure 6 yes Figure 5 The structural schematic diagram of the cover plate 10 shown in another angle, Figure 7 yes Figure 5 The cross-sectional structure diagram of the cover plate 10 shown is after being cut along BB.

[0043] The cover plate 10 is also provided with a limiting protrusion 13. The limiting protrusion 13 is provided on the first surface 11 of the cover plate 10, and protrudes in a direction away from the cover plate 10 along the thickness direction of the cover plate 10. The limiting protrusion 13 is used to abut against the collecting plate 20 to limit the collecting plate 20. Specifically, the limiting protrusion 13 is provided close to the explosion-proof hole 15, and is spaced apart from the explosion-proof hole 15. Along the thickness direction of the cover plate 10, the limiting protrusion 13 is arranged opposite to the groove 19. That is, along the thickness direction of the cover plate 10, the projection of the limiting protrusion 13 on the second surface 12 of the cover plate 10 is located in the groove 19.

[0044] In this embodiment, the limit protrusion 13 can be formed by stamping the cover plate 10 from the second surface 12 to the first surface 11 of the cover plate 10, and the groove 19 can be formed on the second surface 12, that is, the limit protrusion 13 and the groove 19 are formed simultaneously in one stamping process, thereby simplifying the manufacturing process of the cover plate 10 and reducing the production cost of the cover plate 10.

[0045] In this embodiment, there are multiple limiting protrusions 13. Multiple limiting protrusions 13 are arranged around the circumference of the explosion-proof hole 15 and are arranged at intervals from each other. Along the thickness direction of the cover plate 10, each limiting protrusion 13 is arranged opposite to a groove. That is, along the thickness direction of the cover plate 10, the projection of each limiting protrusion 13 on the second surface 12 of the cover plate 10 is located in a groove 19.

[0046] Specifically, the plurality of limiting protrusions 13 include a first limiting protrusion 13a, a second limiting protrusion 13b, a third limiting protrusion 13c and a fourth limiting protrusion 13d. The first limiting protrusion 13a and the second limiting protrusion 13b are respectively located on opposite sides of the explosion-proof hole 15, the third limiting protrusion 13c and the fourth limiting protrusion 13d are respectively located on opposite sides of the explosion-proof hole 15, and are spaced apart from the first limiting protrusion 13a and the second limiting protrusion 13b, and are located on the side of the first limiting protrusion 13a and the second limiting protrusion 13b facing the mounting hole 14. That is, the first limiting protrusion 13a and the third limiting protrusion 13c are located on one side of the explosion-proof hole 15 in the length direction, and the second limiting protrusion 13b and the fourth limiting protrusion 13d are located on the other side of the explosion-proof hole 15 in the length direction. In addition, along the thickness direction of the cover plate 10, the first limiting protrusion 13a is arranged opposite to the first groove 19a, the second limiting protrusion 13b is arranged opposite to the second groove 19b, the third limiting protrusion 13c is arranged opposite to the third groove 19c, and the fourth limiting protrusion 13d is arranged opposite to the fourth groove 19d.

[0047] In this embodiment, there is a first connecting line 101 between the center of the first limiting protrusion 13a and the center of the mounting hole 14, a second connecting line 102 is provided between the center of the second limiting protrusion 13b and the center of the mounting hole 14, a third connecting line 103 is provided between the center of the third limiting protrusion 13c and the center of the mounting hole 14, and a fourth connecting line 104 is provided between the center of the fourth limiting protrusion 13d and the center of the mounting hole 14. The angle α between the first connecting line 101 and the second connecting line 102 is smaller than the angle β between the third connecting line 103 and the fourth connecting line 104.

[0048] Please refer to Figure 3 , Figure 8 and Fig. 9 , Figure 8 yes Figure 3 The schematic diagram of the structure of the explosion-proof valve 30 in the end cover assembly 120 is shown. Fig. 9 yes Figure 6 The structure diagram of the cover plate 10 and the explosion-proof valve 30 after being assembled is shown.

[0049] In the present embodiment, the explosion-proof valve 30 is in the shape of a waist-shaped sheet. Among them, the length direction of the explosion-proof valve 30 is parallel to the length direction of the explosion-proof hole 15. Specifically, the explosion-proof valve 30 is installed in the first assembly sink 17 and covers the explosion-proof hole 15. Exemplarily, the explosion-proof valve 30 can be welded to the groove wall of the first assembly sink 17. It can be understood that 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, so that the gas inside the energy storage device 100 is discharged to the outside of the energy storage device 100 in time, avoiding the energy storage device 100 from exploding due to excessive internal air pressure, thereby improving the reliability of the energy storage device 100 and extending the service life of the energy storage device 100.

[0050] Specifically, the explosion-proof valve 30 has a center line 301. The center line 301 is parallel to the length direction of the explosion-proof valve 30 and passes through the first limiting protrusion 13a and the second limiting protrusion 13b. In the present embodiment, the explosion-proof valve 30 further includes a notched portion 31, a connecting portion 32, a welding portion 33, a first bursting portion 34 and a second bursting portion 35. The second bursting portion 35 is arranged around the circumference of the first bursting portion 34. The first bursting portion 34 and the second bursting portion 35 are connected via the notched portion 31 and the connecting portion 32. Among them, the thickness of the first bursting portion 34 and the thickness of the second bursting portion 35 are both greater than the thickness of the notched portion 31. The welding portion 33 is fixedly connected to the second bursting portion 35 and is arranged around the circumference of the second bursting portion 35. It can be understood that when the energy storage device 100 has thermal runaway, the first bursting portion 34 of the explosion-proof valve 30 bursts in an orderly manner along the notched portion 31, which makes the rupture of the explosion-proof valve 30 orderly and controllable, and prevents the explosion-proof valve 30 from forming multiple flying fragments under the impact of pressure and damaging other components near the energy storage device 100, thereby helping to reduce the thermal runaway area of ​​the energy storage device 100 and making the thermal runaway range of the energy storage device 100 controllable.

[0051] In this embodiment, the notched portion 31 is roughly "C"-shaped. The notched portion 31 includes a first endpoint 311 and a second endpoint 312, and the first endpoint 311 and the second endpoint 312 are arranged at intervals. The connecting portion 32 is fixedly connected between the first endpoint 311 and the second endpoint 312, and is located on the side of the explosion-proof valve 30 away from the mounting hole 14 of the cover plate 10. Under this setting, the cracking position of the explosion-proof valve 30 can be located on the side close to the center of the cover plate 10. When the explosion-proof valve 30 is cracked, the explosion-proof valve 30 will be folded toward the edge of the cover plate 10, thereby avoiding the problem of short circuit caused by the valve plate of the folded explosion-proof valve 30 contacting the component arranged in the center of the cover plate 10, which helps to improve the installation reliability of the energy storage device 100.

[0052] Please refer to Figure 4 , Fig.10 and Fig.11 , Fig.10 yes Figure 3The schematic diagram of the structure of the collecting plate 20 in the end cover assembly 120 is shown. Fig.11 yes Fig.10 The cross-sectional structure diagram of the current collecting plate 20 after being cut along CC is shown.

[0053] In the present embodiment, the current collecting disc 20 is made of metal material. Exemplarily, the current collecting disc 20 is made of aluminum metal. In the present embodiment, the current collecting disc 20 is disc-shaped. Among them, the central axis of the current collecting disc 20 coincides with the central axis of the cover plate 10. Exemplarily, the current collecting disc 20 is rotationally symmetric about the central axis. The current collecting disc 20 includes a main body 21 and a boss portion 22. In the present embodiment, the main body 21 and the boss portion 22 are integrally formed. Exemplarily, the main body 21 and the boss portion 22 can be integrally formed by a stamping process.

[0054] Specifically, the main body 21 is located on the side of the first surface 11 of the cover plate 10 away from the second surface 12. The main body 21 includes a first surface 211 and a second surface 212, and the first surface 211 and the second surface 212 are arranged opposite to each other along the thickness direction of the main body 21. The first surface 211 is the surface of the main body 21 facing the cover plate 10, and the second surface 212 is the surface of the main body 21 away from the cover plate 10.

[0055] The boss portion 22 is fixedly connected to the first surface 211 of the main body 21. In this embodiment, the boss portion 22 is used to be welded with the cover plate 10 to ensure that the electrons of the electrode assembly in the energy storage device 100 can be conducted to the external circuit through the end cap assembly 120 to achieve electrical connection between the energy storage device 100 and the external device. Specifically, the boss portion 22 includes a first step portion 221 and a second step portion 222, and the second step portion 222 is fixedly connected to the side of the first step portion 221 facing away from the main body 21. Among them, the circumference of the first step portion 221 is arranged around the circumference of the second step portion 222, and protrudes relative to the circumference of the second step portion 222. Along the thickness direction of the end cap assembly 120, the height of the first step portion 221 is greater than the height of the first limiting protrusion 13a, the second limiting protrusion 13b, the third limiting protrusion 13c and the fourth limiting protrusion 13d. The surface (not marked in the figure) of the second step portion 222 facing away from the first step portion 221 is the surface of the boss portion 22 facing away from the main body portion 21 .

[0056] In this embodiment, the second step portion 222 includes a first sub-portion 222a and a second sub-portion 222b. The first sub-portion 222a is fixedly connected to the side of the first step portion 221 away from the main body 21, and the second sub-portion 222b is fixedly connected to the side of the first sub-portion 222a away from the main body 21. In the direction from the main body 21 to the boss portion 22, the size of the first sub-portion 222a gradually decreases.

[0057] The current collecting plate 20 is also provided with a welding groove 23, a through hole 24, a liquid injection hole 25 and a stress release hole 26. Among them, the welding groove 23, the through hole 24 and the stress release hole 26 are all provided in the main body 21 of the current collecting plate. Specifically, the opening of the welding groove 23 is located on the first surface 211 of the main body 21, and the welding groove 23 is recessed from the first surface 211 to the direction of the second surface 212, and passes through the peripheral side surface of the main body 21. Exemplarily, the welding groove 23 is in the shape of a long strip, extends in the radial direction of the main body 21, and passes through the peripheral side surface of the current collecting plate 20.

[0058] In this embodiment, the welding groove 23 includes a groove bottom wall 231, a first groove side wall 232 and two second groove side walls 233. Among them, the groove bottom wall 231 protrudes from the main body 21 in the direction away from the boss portion 22. The groove bottom wall 231 of the welding groove 23 is used to weld with the pole ear of the electrode assembly to achieve electrical connection between the electrode assembly and the current collecting plate 20. It can be understood that the groove bottom wall 231 of the welding groove 23 protrudes from the main body 21 in the direction away from the boss portion 22, which can increase the welding area between the current collecting plate 20 and the pole ear of the electrode assembly, so that the current collecting plate 20 is in close contact with the pole ear, which can avoid false welding, ensure the welding strength between the current collecting plate 20 and the pole ear of the electrode assembly, and improve the consistency of laser welding between the pole ear and the current collecting plate 20. The first groove side wall 232 and the two second groove side walls 233 are fixedly connected to the groove bottom wall 231. Specifically, the first groove side wall 232 is arranged near the first step portion 221 of the boss portion 22. Along the width direction of the welding groove 23 , the two second groove side walls 233 are respectively connected to two opposite sides of the first groove side wall 232 .

[0059] In this embodiment, there may be multiple welding grooves 23, and the multiple welding grooves 23 are arranged at intervals around the central axis of the current collecting plate 20 to ensure the stability of the welding between the main body 21 of the current collecting plate 20 and the pole ear of the electrode assembly. Exemplarily, there are three welding grooves 23. In some other embodiments, there may be one, two or more than four welding grooves 23, and the embodiment of the present application does not specifically limit the number of welding grooves 23.

[0060] In this embodiment, along the thickness direction of the main body 21, the stress release hole 26 penetrates the main body 21 and the first groove side wall 232 of the welding groove 23, and penetrates the first groove side wall 232. In this embodiment, along the thickness direction of the main body 21, the stress release hole 26 also penetrates the second groove side wall 233. The stress release hole 26 is used to release the stress of the main body 21 of the collecting plate 20 to prevent the main body 21 from cracking due to excessive stress concentration. Exemplarily, there are multiple stress release holes 26. Every two stress release holes 26 penetrate the first groove side wall 232 of a welding groove 23, and penetrate a second groove side wall 233 respectively. Under this setting, the stress of the main body 21 of the collecting plate 20 can be further released, avoiding the cracking problem of the main body 21 of the collecting plate 20 due to stress concentration.

[0061] It should be understood that since the current collecting plate 20 is made of aluminum metal, which is relatively soft in texture, the aluminum metal is easy to flow during the stamping process of the current collecting plate 20, causing stress concentration problems at local positions of the first groove side wall 232 and the second groove side wall 233 of the welding groove 23 in the current collecting plate 20 due to the increased thickness, which not only causes cracking problems in the current collecting plate 20, but also reduces the consistency of the welding between the electrode ear and the recording plate of the electrode assembly. In this embodiment, by providing a stress release hole 26 and making the stress release hole 26 pass through the first groove side wall 232 and the second groove side wall 233, on the one hand, the consistency of the thickness of the first groove side wall 232 and the second groove side wall 233 and the groove bottom wall 231 in the welding groove 23 can be ensured, thereby helping to improve the welding consistency between the collecting plate 20 and the pole ear of the electrode assembly. On the other hand, the stress release hole 26 can release the stress at the locally thickened position of the first groove side wall 232 and the second groove side wall 233, avoiding stress concentration and density concentration at the locally thickened position of the first groove side wall 232 and the second groove side wall 233, thereby avoiding the cracking problem of the collecting plate 20 due to stress concentration. In addition, when the gas inside the energy storage device 100 impacts the collecting plate 20, the stress release holes 26 provided on the collecting plate 20 can also play the role of exhaust, so that the collecting plate 20 is not easily deformed when subjected to the impact force of the gas, and the exhaust passage between the collecting plate 20 and the cover plate 10 is prevented from being blocked due to the collecting plate 20 arching and deforming toward the cover plate 10, thereby helping to ensure that the gas inside the energy storage device 100 is discharged smoothly, and further helping to improve the safety performance of the energy storage device 100.

[0062] The through hole 24 penetrates the current collecting plate 20 along the thickness direction of the current collecting plate 20. Specifically, the main body 21 of the current collecting plate 20 is provided with a through hole 24, and the through hole 24 penetrates the main body 21 along the thickness direction of the main body 21. In this embodiment, the through hole 24 and the welding groove 23 and the stress release hole 26 are all arranged at intervals. Exemplarily, the through hole 24 is a circular hole. In some other embodiments, the through hole 24 can also be a square hole or other special-shaped holes. In this embodiment, there are multiple through holes 24. Multiple through holes 24 are arranged at intervals from each other. Among them, the multiple through holes 24 form three through hole groups, and the three through hole groups are arranged at intervals from each other around the central axis of the current collecting plate 20. Two adjacent through hole groups are respectively located on opposite sides of a welding groove 23. In addition, when there are multiple welding grooves 23, at least one through hole 24 is provided between two adjacent welding grooves 23.

[0063] In this embodiment, the injection hole 25 penetrates the current collecting disk 20 along the thickness direction of the current collecting disk 20, and is spaced apart from the through hole 24 and the welding groove 23. Specifically, the opening of the injection hole 25 is located on the surface of the boss portion 22 away from the main body 21. The injection hole 25 is recessed from the surface of the boss portion 22 away from the main body 21 toward the main body 21, and penetrates the surface of the main body 21 away from the cover plate 10, and is connected to the receiving cavity of the shell 110. Among them, the central axis of the injection hole 25 (not shown) coincides with the central axis of the current collecting disk 20. It can be understood that the electrolyte can be injected into the receiving cavity through the injection hole 25 to achieve the perfusion of the electrolyte of the energy storage device 100. Since the central axis of the injection hole 25 coincides with the central axis of the current collecting disk 20, the electrolyte can quickly infiltrate from the center position of the electrode assembly to enhance the infiltration effect of the electrode assembly in the electrolyte.

[0064] The injection hole 25 includes a step portion 251 and an injection portion 252. The injection portion 252 is located on the side of the step portion 251 facing the main body 21 of the collecting plate 20, and is connected to the step portion 251. Among them, the injection portion 252 and the step portion 251 are both circular holes. The step portion 251 is recessed from the surface of the boss portion 22 away from the main body 21 toward the main body 21, and the aperture of the step portion 251 gradually decreases along the recessed direction. That is, the step portion 251 is a conical hole to facilitate the introduction of the injection head of the injection device. The injection portion 252 is recessed from the surface of the main body 21 away from the boss portion 22 toward the step portion 251 and penetrates the bottom wall of the step portion 251. Among them, the aperture of the injection portion 252 is smaller than the aperture of the step portion 251.

[0065] In addition, the end cap assembly 120 may further include a sealing member (not shown), which seals the injection hole 25. The shape of the sealing member is the same as that of the injection hole 25, so that the injection hole 25 can be sealed.

[0066] Please refer again Figure 4. In the assembled end cover assembly 120, the boss portion 22 of the current collecting plate 20 is inserted into the mounting hole 14 of the cover plate 10, and the injection hole 25 on the boss portion 22 is exposed relative to the mounting hole 14. In other words, the mounting hole 14 exposes the injection hole 25. Specifically, the surface of the first step portion 221 of the boss portion 22 facing the second step portion 222 abuts against the first surface 11 of the cover plate 10. Under this arrangement, the cover plate 10 and the main body 21 of the current collecting plate 20 can be spaced apart, and an air flow channel can be formed between the cover plate 10 and the main body 21 of the current collecting plate 20 for gas flow inside the energy storage device 100. Exemplarily, the bottom wall of the mounting groove 16 of the cover plate 10 is located on the side of the boss portion 22 facing away from the surface of the main body 21 toward the main body 21.

[0067] The second step portion 222 of the boss portion 22 is provided in the mounting hole 14. The first sub-portion 222a of the second step portion 222 is installed in the first sub-hole 141 of the mounting hole 14, and the peripheral side surface of the first sub-portion 222a contacts the hole wall surface of the first sub-hole 141, and the second sub-portion 222b of the second step portion 222 is provided in the second sub-hole 142 of the mounting hole 14. It can be understood that by gradually reducing the aperture of the first sub-hole 141 of the mounting hole 14 and gradually reducing the size of the first sub-portion 222a of the second step portion 222, the shape of the first sub-portion 222a can be adapted to the shape of the first sub-hole 141, so as to facilitate the alignment and installation between the collecting plate 20 and the cover plate 10, which helps to reduce the precision requirements of the installation process.

[0068] The first limiting protrusion 13a, the second limiting protrusion 13b, the third limiting protrusion 13c and the fourth limiting protrusion 13d of the cover plate 10 are arranged opposite to the main body 21 of the current collecting plate 20, and are staggered with the explosion-proof valve 30 and the welding groove 23 on the current collecting plate 20. In this embodiment, along the thickness direction of the end cover assembly 120, the projections of the first limiting protrusion 13a, the second limiting protrusion 13b, the third limiting protrusion 13c, the fourth limiting protrusion 13d and the explosion-proof valve 30 on the main body 21 of the current collecting plate 20 are all located between two adjacent welding grooves 23. That is, along the thickness direction of the end cover assembly 120, the explosion-proof hole 15 of the cover plate 10 is arranged opposite to at least one through hole 24 between two adjacent welding grooves 23, and is staggered with each welding groove 23 of the collecting plate 20, so that the explosion-proof hole 15 is connected to the interior of the energy storage device 100 through the through hole 24 of the collecting plate 20, thereby realizing exhaust pressure relief.

[0069] It can be understood that when the gas inside the energy storage device 100 impacts the collecting plate 20, the first limiting protrusion 13a, the second limiting protrusion 13b, the third limiting protrusion 13c and the fourth limiting protrusion 13d can abut against the main body 21 of the collecting plate 20 to limit the main body 21 of the collecting plate 20 and restrict the movement of the collecting plate 20 toward the cover plate 10, which can prevent the collecting plate 20 from moving toward the cover plate 10 under the action of the airflow, avoid the exhaust channel between the main body 21 of the collecting plate 20 and the cover plate 10 from being blocked, so that the gas in the energy storage device 100 can smoothly impact the explosion-proof valve, thereby ensuring that the explosion-proof valve 30 can normally open the valve to release pressure when thermal runaway occurs in the energy storage device 100, which helps to improve the safety and reliability of the energy storage device 100. In addition, among the multiple limiting protrusions 13 of the cover plate 10, the first limiting protrusion 13a, the second limiting protrusion 13b and the first step portion 221 of the collecting plate 20 form a stable triangular support structure, which can prevent the portion of the collecting plate 20 close to the cracked side of the explosion-proof valve 30 from approaching the explosion-proof valve 30, thereby ensuring the air permeability of the cracked side of the explosion-proof valve 30, thereby helping to improve the exhaust smoothness of the energy storage device 100. At the same time, the third limiting protrusion 13c and the fourth limiting protrusion 13d can also form a stable triangular support structure with the first step portion 221 to further enhance the structural strength of the triangular support structure formed by the first limiting protrusion 13a, the second limiting protrusion 13b and the first step portion 221, and avoid the portion of the collecting plate 20 in the triangular area formed by the first limiting protrusion 13a, the second limiting protrusion 13b and the first step portion 221 from being recessed toward the cover plate 10, thereby further avoiding the exhaust channel between the main body 21 of the collecting plate 20 and the cover plate 10 from being blocked, ensuring that the gas inside the energy storage device 100 can be discharged smoothly and impact the explosion-proof valve 30, thereby ensuring that the explosion-proof valve 30 can normally open the valve to release pressure when thermal runaway occurs in the energy storage device 100, thereby improving the safety performance of the energy storage device 100.

[0070] 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.

[0071] 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; the implementation methods and features of the implementation methods of the present application can be combined with each other without conflict. 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 end cover assembly includes a cover plate, an explosion-proof valve and a collecting plate, the cover plate includes 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 plate, the cover plate is provided with a mounting hole and an explosion-proof hole, the mounting hole and the explosion-proof hole both penetrate the first surface and the second surface along the thickness direction of the cover plate, and are arranged at intervals from each other, the cover plate is also provided with a first limiting protrusion, a second limiting protrusion, a third limiting protrusion and a fourth limiting protrusion, the first limiting protrusion, the second limiting protrusion, the third limiting protrusion and the fourth limiting protrusion are all arranged on the first surface, and are arranged at intervals from the mounting hole and the explosion-proof hole, the first limiting protrusion and the second limiting protrusion are respectively located on opposite sides of the explosion-proof hole, the third limiting protrusion and the fourth limiting protrusion are respectively located on opposite sides of the explosion-proof hole, and are arranged at intervals from the first limiting protrusion and the second limiting protrusion, and are located on the side of the first limiting protrusion and the second limiting protrusion facing the mounting hole; The explosion-proof valve is installed on the cover plate and covers the explosion-proof hole. The explosion-proof valve has a center line, which is parallel to the length direction of the explosion-proof valve and passes through the first limiting protrusion and the second limiting protrusion. The explosion-proof valve also includes a notched portion and a connecting portion. The notched portion includes a first end point and a second end point. The first end point and the second end point are arranged at intervals. The connecting portion is fixedly connected between the first end point and the second end point and is located on a side of the explosion-proof valve away from the mounting hole. The collecting plate includes a main body, a first step portion and a second step portion, the main body is located on a side of the first surface away from the second surface, and is arranged opposite to the first limiting protrusion, the second limiting protrusion, the third limiting protrusion and the fourth limiting protrusion, the main body includes a first surface and a second surface, and along the thickness direction of the main body, the first surface and the second surface are arranged opposite to each other, the main body is provided with a through hole, the through hole passes through the first surface and the second surface along the thickness direction of the main body, and is arranged opposite to the explosion-proof valve, and is staggered with the limiting protrusion, the first step portion is arranged on the first surface, the surface of the first step portion away from the main body is in contact with the first surface, and the height of the first step portion is greater than the height of the first limiting protrusion, the second limiting protrusion, the third limiting protrusion and the fourth limiting protrusion, and the second step portion is fixedly connected to the surface of the first step portion facing away from the main body, and is penetrated through the mounting hole.

2. The end cap assembly according to claim 1, characterized in that: There is a first connecting line between the center of the first limiting protrusion and the center of the mounting hole, there is a second connecting line between the center of the second limiting protrusion and the center of the mounting hole, there is a third connecting line between the center of the third limiting protrusion and the center of the mounting hole, there is a fourth connecting line between the center of the fourth limiting protrusion and the center of the mounting hole, and the angle α between the first connecting line and the second connecting line is smaller than the angle β between the third connecting line and the fourth connecting line.

3. The end cap assembly according to claim 1, characterized in that: The third limiting protrusion and the fourth limiting protrusion are located on a straight line where an edge of the explosion-proof valve close to the mounting hole is located.

4. The end cap assembly according to any one of claims 1 to 3, characterized in that: The cover plate is also provided with a first groove, a second groove, a third groove and a fourth groove, the openings of the first groove, the second groove, the third groove and the fourth groove are all located on the second surface, the first groove, the second groove, the third groove and the fourth groove are spaced apart from each other, and are spaced apart from the mounting hole and the explosion-proof hole, and along the thickness direction of the cover plate, the first groove is arranged opposite to the first limiting protrusion, the second groove is arranged opposite to the second limiting protrusion, the third groove is arranged opposite to the third limiting protrusion, and the fourth groove is arranged opposite to the fourth limiting protrusion.

5. The end cap assembly according to claim 1, characterized in that: The main body is also provided with a welding groove, the opening of which is located on the first surface, the welding groove is spaced apart from the through hole, and along the thickness direction of the end cover assembly, the welding groove and the first limiting protrusion, the second limiting protrusion, the third limiting protrusion, the fourth limiting protrusion and the explosion-proof valve are all staggered.

6. The end cap assembly according to claim 5, characterized in that: There are a plurality of through holes and a plurality of welding grooves, and the plurality of welding grooves are arranged at intervals around the center of the main body, and at least one through hole is provided between two adjacent welding grooves; Along the thickness direction of the end cover assembly, the first limiting protrusion, the second limiting protrusion, the third limiting protrusion, the fourth limiting protrusion and the projection of the explosion-proof valve on the main body are all located between two adjacent welding grooves.

7. The end cap assembly according to claim 5 or 6, characterized in that: The welding groove comprises a groove bottom wall and a first groove side wall close to the first step portion, wherein the first groove side wall is fixedly connected to the groove bottom wall; The main body is further provided with a stress release hole, and along the thickness direction of the main body, the stress release hole penetrates the main body and the first groove side wall.

8. The end cap assembly according to claim 7, characterized in that: The welding groove also includes two second groove side walls, which are fixedly connected to the groove bottom wall. Along the width direction of the welding groove, the two second groove side walls are respectively connected to the opposite sides of the first groove side wall; along the thickness direction of the main body, the stress release hole also penetrates the second groove side walls.

9. The end cap assembly according to claim 8, characterized in that: There are a plurality of stress release holes, and every two of the stress release holes penetrate through one of the first groove side walls of the welding groove, and penetrate through one of the second groove side walls respectively.

10. An energy storage device, characterized in that: It comprises a shell, an electrode assembly and an end cover assembly as described in any one of claims 1 to 9, the shell is provided with an opening and a receiving cavity, the electrode assembly is received in the receiving cavity, the end cover assembly closes the opening, and the collecting plate is electrically connected to the electrode assembly.

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

Images