Current collecting disc, end cover assembly, energy storage device and electric equipment

Abstract

The utility model provides a current collecting plate, an end cover assembly, an energy storage device and electric equipment, and can solve the problem of cracking of the current collecting plate due to stress concentration, so that the service life of the current collecting plate is prolonged, and the use reliability of the energy storage device is improved. The collector plate comprises a first face and a second face, the first face and the second face are arranged oppositely in the thickness direction of the collector plate, the collector plate is further provided with a welding groove and a stress release hole, an opening of the welding groove is located in the first face, and the welding groove comprises a groove bottom wall and a first groove side wall close to the center of the collector plate. The first groove side wall is fixedly connected between the groove bottom wall and the first face, and the stress release hole penetrates through the first face, the second face and the first groove side wall in the thickness direction of the flow collecting disc.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage, and in particular, to a current collector plate, an end cover assembly, an energy storage device, and an electrical device. Background Art

[0002] Energy storage devices such as secondary batteries are widely used as the main power source of electrical devices due to their recyclable characteristics. With the gradual increase in the demand for energy storage devices, people's requirements for their various performances are also getting higher and higher. In existing energy storage devices, there is a problem of stress concentration at the part where the current collector plate is welded to the tab of the energy storage device, resulting in easy cracking of the current collector plate, shortening the service life of the current collector plate, and reducing the reliability of the energy storage device in use. Summary of the Utility Model

[0003] The present application provides a current collector plate, an end cover assembly, an energy storage device, and an electrical device, which can solve the problem of cracking of the current collector plate caused by stress concentration, thereby helping to extend the service life of the current collector plate and improve the reliability of the energy storage device in use.

[0004] In a first aspect, the present application provides a current collector plate for an energy storage device. The current collector plate includes a first surface and a second surface, and in the thickness direction of the current collector plate, the first surface and the second surface face away from each other. The current collector plate is further provided with a welding groove and a stress relief hole. The opening of the welding groove is located on the first surface. The welding groove includes a groove bottom wall and a first groove side wall close to the center of the current collector plate. The first groove side wall is fixedly connected between the groove bottom wall and the first surface. In the thickness direction of the current collector plate, the stress relief hole penetrates through the first surface, the second surface, and the first groove side wall.

[0005] Wherein, the welding groove further includes two second groove side walls, and both of the two second groove side walls are fixedly connected between the groove bottom wall and the first surface. In the width direction of the welding groove, the two second groove side walls are respectively connected to opposite sides of the first groove side wall; in the thickness direction of the current collector plate, the stress relief hole further penetrates through one of the second groove side walls.

[0006] Wherein, there are multiple welding grooves and stress relief holes. Every two stress relief holes penetrate through the first groove side wall of one welding groove and respectively penetrate through the two second groove side walls of one welding groove.

[0007] Wherein, the ratio of the cross-sectional area of the stress relief hole to the area of the groove bottom wall of the welding groove is between 0.0083 and 0.0589.

[0008] The current collecting plate is further provided with a positioning notch, and the positioning notch penetrates the first surface, the second surface and the peripheral side surface of the current collecting plate along the thickness direction of the current collecting plate, and is spaced apart from the welding groove.

[0009] There are multiple positioning notches, and each positioning notch is located between two adjacent welding grooves.

[0010] In a second aspect, the present application further provides an end cover assembly, comprising a cover plate and a current collecting plate as described in any one of the above items, wherein the cover plate is installed on a side of the first surface facing away from the second surface.

[0011] Wherein, the collecting plate includes a main body and a boss portion, the main body includes the first surface and the second surface, the main body is also provided with a through hole, the welding groove and the stress release hole, the through hole passes through the first surface and the second surface along the thickness direction of the main body, and is spaced apart from the welding groove and the stress release hole, the boss portion is provided on the first surface, and is spaced apart from the welding groove and the stress release hole; the cover plate is sleeved on the boss portion and arranged opposite to the main body, the cover plate is provided with an explosion-proof hole, the explosion-proof hole passes through the cover plate along the thickness direction of the cover plate, the explosion-proof hole is staggered with the welding groove along the thickness direction of the end cover assembly, and is arranged opposite to the through hole, the surface of the cover plate facing the main body is provided with a limiting protrusion, the limiting protrusion is spaced apart from the explosion-proof hole, and the limiting protrusion is staggered with the welding groove and the through hole along the thickness direction of the end cover assembly; the end cover assembly also includes an explosion-proof valve, the explosion-proof valve is installed on the cover plate, and covers the explosion-proof hole.

[0012] In a third 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 current collecting plate is electrically connected to the electrode assembly.

[0013] In a fourth 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.

[0014] The current collector plate provided by this application is provided with stress relief holes that penetrate the first surface, the second surface of the current collector plate, and the first groove sidewall of the welding groove. On the one hand, the stress in the part of the welding groove close to the center of the current collector plate can be released through the stress relief holes, avoiding the problem of stress concentration in the current collector plate due to local thickness deviation, thus being able to prevent the current collector plate from cracking, and further contributing to extending the service life of the current collector plate and improving the use reliability of the energy storage device. On the other hand, the consistency of the groove wall thickness of the welding groove can be ensured, thus being able to avoid the influence of the groove wall thickness of the welding groove on the welding between the current collector plate and the tab of the electrode assembly, and contributing to improving the welding consistency between the current collector plate and the tab of the electrode assembly. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions of the embodiments of this application, the drawings required for the embodiments of this application will be described below.

[0016] Figure 1 is a schematic structural diagram of the energy storage device provided by the embodiment of this application;

[0017] Figure 2 is Figure 1 a schematic structural diagram of the end cap assembly in the shown energy storage device;

[0018] Figure 3 is Figure 2 a schematic exploded structural diagram of the shown end cap assembly;

[0019] Figure 4 is Figure 2 a schematic cross-sectional structural diagram of the shown end cap assembly after being cut along A-A;

[0020] Figure 5 is Figure 3 a schematic structural diagram of the current collector plate in the shown end cap assembly;

[0021] Figure 6 is Figure 5 a schematic cross-sectional structural diagram of the shown current collector plate after being cut along B-B;

[0022] Figure 7 is Figure 3 a schematic structural diagram of the cover plate in the shown end cap assembly;

[0023] Figure 8 is Figure 7 a schematic structural diagram of the shown cover plate at another angle;

[0024] Figure 9 is Figure 8 a schematic cross-sectional structural diagram of the shown cover plate after being cut along C-C;

[0025] Figure 10 isFigure 8 Schematic structural diagram of the assembled cover plate and explosion-proof valve.

[0026] The names corresponding to the reference numerals in the figure are as follows:

[0027] Energy storage device 100, housing 110, end cover assembly 120, cover plate 10, current collector plate 20, explosion-proof valve 30, protection member 40, first surface 11, second surface 12, mounting hole 14, first sub-hole 141, second sub-hole 142, explosion-proof hole 15, mounting sink 16, first assembly sink 17, second assembly sink 18, groove 19, limiting protrusion 13, central plane 301, main body portion 21, boss portion 22, first face 211, second face 212, first step portion 221, second step portion 222, first sub-portion 222a, second sub-portion 222b, welding groove 23, through hole 24, liquid injection hole 25, stress relief hole 26, positioning notch 27, bottom wall of the groove 231, first side wall of the groove 232, second side wall of the groove 233, step portion 251, liquid injection portion 252. Detailed implementation manners

[0028] Next, the technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present application.

[0029] Please refer to Figure 1 , Figure 1 , which is a schematic structural diagram of the energy storage device 100 provided by the embodiment of the present application.

[0030] In this embodiment, the energy storage device 100 is a cylindrical battery. The energy storage device 100 includes a housing 110, an end cover assembly 120, and an electrode assembly (not shown in the figure). Exemplarily, the housing 110 can be made of aluminum. Among them, the housing 110 is in a cylindrical shape. The housing 110 has an opening (not shown in the figure) and a receiving cavity (not shown in the figure). 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 core (not shown in the figure) and a tab (not shown in the figure). The tab is fixedly connected to the battery core. The receiving cavity is also used to receive the electrolyte, and the electrode assembly is immersed in the electrolyte. The end cover assembly 120 is installed on one side in the height direction of the housing 110 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 functions.

[0031] Please refer to Figure 2 , Figure 3 and Figure 4 , Figure 2 is Figure 1 a schematic structural diagram of the end cover assembly 120 in the energy storage device 100 shown in Figure 3 is Figure 2 an exploded structural diagram of the end cover assembly 120 shown in Figure 4 isFigure 2 Schematic cross-sectional structure diagram of the shown end cap assembly 120 after being cut along A-A. Among them, "being cut along A-A" means being cut along the plane where the A-A line is located.

[0032] The end cap assembly 120 includes a cover plate 10, a current collector plate 20, an explosion-proof valve 30, and a protection member 40. The current collector plate 20 is installed inside the housing 110 and is electrically connected to the tab of the battery cell. Exemplarily, the current collector plate 20 can be electrically connected to the tab of the electrode assembly by welding. The cover plate 10 is installed on one side in the thickness direction of the current collector plate 20. Both the explosion-proof valve 30 and the protection member 40 are installed on the cover plate 10 and are spaced apart from the current collector plate 20. Along the thickness direction of the end cap assembly 120, the explosion-proof valve 30 and the protection member 40 are oppositely arranged.

[0033] It should be noted that the orientation terms such as "outer" and "inner" involved in this application are all described with respect to Figure 1 the orientation of the shown energy storage device 100. Taking the outside of the housing 110 as "outer" and the inside of the housing 110 as "inner", similar descriptions hereinafter can be understood in the same way.

[0034] Please refer to Figure 4 , Figure 5 and Figure 6 , Figure 5 which is Figure 3 the schematic structure diagram of the current collector plate 20 in the shown end cap assembly 120, Figure 6 and Figure 5 is the schematic cross-sectional structure diagram of the shown current collector plate 20 after being cut along B-B.

[0035] In this embodiment, the current collector plate 20 is made of a metal material. Exemplarily, the current collector plate 20 is made of aluminum metal. In this embodiment, the current collector plate 20 is in a disc shape. Among them, the central axis of the current collector plate 20 coincides with the central axis of the cover plate 10. Exemplarily, the current collector plate 20 is rotationally symmetric about the central axis. In this embodiment, the current collector plate 20 includes a first surface 211 and a second surface 212. Along the thickness direction of the current collector plate 20, the first surface 211 and the second surface 212 are arranged opposite to each other. The current collector plate 20 further includes a main body portion 21 and a boss portion 22. In this embodiment, the main body portion 21 and the boss portion 22 are integrally formed. Exemplarily, the main body portion 21 and the boss portion 22 can be integrally formed by a stamping process.

[0036] Specifically, the main body portion 21 includes a first surface 211 and a second surface 212. Along the thickness direction of the main body portion 21, the first surface 211 and the second surface 212 are arranged in opposite directions. The boss portion 22 is located at the center of the current collector plate 20 and is fixedly connected to the first surface 211 of the main body portion 21. In this embodiment, the boss portion 22 is used for welding 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 cover assembly 120, so as to realize the electrical connection between the energy storage device 100 and external devices. In this embodiment, 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 portion 21. Among them, the peripheral surface of the first step portion 221 surrounds the peripheral surface of the second step portion 222 and protrudes relative to the peripheral surface of the second step portion 222. 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. Among them, along the thickness direction of the end cover assembly 120, the height of the second step portion 222 is greater than the height of the limit protrusion 13.

[0037] 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 facing away from the main body portion 21, and the second sub-portion 222b is fixedly connected to the side of the first sub-portion 222a facing away from the main body portion 21. Among them, along the direction from the main body portion 21 to the boss portion 22, the size of the first sub-portion 222a gradually decreases.

[0038] The current collector plate 20 is further provided with a welding groove 23, a through hole 24, a liquid injection hole 25, a stress relief hole 26 and a positioning notch 27. Among them, the welding groove 23, the through hole 24, the stress relief hole 26 and the positioning notch 27 are all arranged on the main body portion 21 of the current collector plate. Specifically, the opening of the welding groove 23 is located on the first surface 211 of the main body portion 21. The welding groove 23 is recessed from the first surface 211 towards the second surface 212 and penetrates the peripheral side surface of the main body portion 21. Exemplarily, the welding groove 23 is strip-shaped and extends along the radial direction of the main body portion 21 and penetrates the peripheral side surface of the current collector plate 20. In this embodiment, the welding groove 23 is also spaced from the boss portion 22.

[0039] 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 portion 21 in a direction away from the boss portion 22. The groove bottom wall 231 of the welding groove 23 is used for welding with the tab of the electrode assembly to achieve electrical connection between the electrode assembly and the current collector plate 20. It can be understood that the groove bottom wall 231 of the welding groove 23 protruding from the main body portion 21 in a direction away from the boss portion 22 can increase the welding area between the current collector plate 20 and the tab of the electrode assembly, enabling the current collector plate 20 to be in close contact with the tab. This can not only avoid false soldering and ensure the welding strength between the current collector plate 20 and the tab of the electrode assembly, but also improve the consistency of laser welding between the tab and the current collector plate 20. In addition, the width a of the groove bottom wall 231 of the welding groove 23 is between 5 mm and 6 mm, and the length b of the groove bottom wall 231 of the welding groove 23 is between 19 mm and 20 mm. Exemplarily, the width a of the groove bottom wall 231 of the welding groove 23 is 5.43 mm, and the length b of the groove bottom wall 231 of the welding groove 23 is 19.72 mm. That is, the area of the groove bottom wall 231 of the welding groove 23 is between 95 mm 2 and 120 mm 2 Exemplarily, the area of the groove bottom wall 231 of the welding groove 23 is 107.0796 mm 2 .

[0040] Both the first groove side wall 232 and the two second groove side walls 233 are fixedly connected between the groove bottom wall 231 and the first surface 211. Specifically, the first groove side wall 232 is disposed close to the center of the current collector plate 20. That is, the first groove side wall 232 is disposed close to the boss portion 22. Along the width direction of the welding groove 23, the two second groove side walls 233 are respectively connected to opposite sides of the first groove side wall 232.

[0041] In this embodiment, there can be multiple welding grooves 23. The multiple welding grooves 23 are arranged at intervals around the central axis of the current collector plate 20 to ensure the stability of welding between the main body portion 21 of the current collector plate 20 and the tab of the electrode assembly. Exemplarily, there are three welding grooves 23. In some other embodiments, there can also be one, two, or more than four welding grooves 23. The embodiments of the present application do not specifically limit the number of the welding grooves 23.

[0042] In this embodiment, in the thickness direction of the main body portion 21 of the current collector plate 20, the stress relief hole 26 penetrates through the first surface 211, the second surface 212 of the main body portion 21, and the first groove side wall 232 of the welding groove 23. Among them, the aperture d of the stress relief hole 26 is between 1 mm and 3 mm. Exemplarily, the aperture d of the stress relief hole 26 is 2 mm. That is to say, the area of the cross-section of the stress relief hole 26 is between 0.25π and 2.25π. Exemplarily, the area of the cross-section of the stress relief hole 26 is π. In this embodiment, the ratio of the area of the cross-section of the stress relief hole 26 to the area of the bottom wall 231 of the welding groove 23 is between 0.0083 and 0.0589. Exemplarily, the ratio of the area of the cross-section of the stress relief hole 26 to the area of the bottom wall 231 of the welding groove 23 is 0.0293. It should be noted that the cross-section of the stress relief hole 26 refers to the section cut along a plane perpendicular to the depth direction of the stress relief hole 26.

[0043] In addition, in the thickness direction of the main body portion 21 of the current collector plate 20, the stress relief hole 26 also penetrates through the second groove side wall 233. The stress relief hole 26 is used to release the stress of the main body portion 21 of the current collector plate 20, and avoid cracking of the main body portion 21 of the current collector plate 20 due to excessive stress concentration. Exemplarily, there are multiple stress relief holes 26. Every two stress relief holes 26 penetrate through the first groove side wall 232 of a welding groove 23, and respectively penetrate through the two second groove side walls 233 of one said welding groove 23. Under this setting, the stress of the main body portion 21 of the current collector plate 20 can be further released, so that the cracking problem of the main body portion 21 of the current collector plate 20 caused by stress concentration can be further avoided.

[0044] It should be understood that since the current collecting plate 20 is made of aluminum metal and has a relatively soft texture, during the stamping process of the current collecting plate 20, the aluminum metal is prone to flow, resulting in stress concentration and density concentration in some areas of the current collecting plate 20 due to increased thickness. This will not only cause cracking problems in the current collecting plate 20 but also reduce the welding consistency between the tab of the electrode assembly and the current collecting plate 20. In this embodiment, the thickness of the part of the welding groove 23 of the current collecting plate 20 close to the center of the current collecting plate 20 is relatively thick, and stress concentration problems are likely to occur. By providing stress relief holes 26 on the main body 21 of the current collecting plate 20 and making the stress relief holes 26 penetrate at least the main body 21 and the first groove side wall 232 of the welding groove 23, on the one hand, the stress in the part of the welding groove 23 close to the center of the current collecting plate 20 can be released through the stress relief holes 26, avoiding stress concentration problems caused by the relatively thick local position of the current collecting plate 20, thereby being able to avoid cracking of the current collecting plate 20, and further contributing to extending the service life of the current collecting plate and improving the use reliability of the energy storage device. On the other hand, the consistency of the wall thickness of the welding groove 23 can be ensured, thereby being able to avoid the influence of the wall thickness of the welding groove 23 on the welding between the current collecting plate 20 and the tab of the electrode assembly, and contributing to improving the welding consistency between the current collecting plate 20 and the tab of the electrode assembly.

[0045] 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 is spaced from both the welding groove 23 and the stress relief hole 26. 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 irregular holes. In this embodiment, there are multiple through holes 24. The multiple through holes 24 are arranged at intervals. Among them, the multiple through holes 24 form three through hole groups, and the three through hole groups are arranged at intervals around the central axis of the current collecting plate 20. Adjacent two 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 adjacent two welding grooves 23.

[0046] Along the thickness direction of the current collecting plate 20, the positioning notch 27 penetrates the first surface 211, the second surface 212 and the circumferential side surface of the current collecting plate 20, and is spaced from both the welding groove 23, the through hole 24 and the boss portion 22. In this embodiment, there are multiple positioning notches 27. The multiple positioning notches 27 are arranged at intervals. Among them, when there are multiple welding grooves 23, each positioning notch 27 is located between adjacent two welding grooves 23 to achieve the positioning and clamping of the placement position of the current collecting plate 20.

[0047] It can be understood that by providing positioning notches 27 between two adjacent welding grooves 23, when the current collector plate 20 is laser welded to the tab of the electrode assembly, the laser welding equipment can identify the position of the welding groove 23 through the positioning notch 27, so as to strictly control the placement position of the current collector plate 20 on the laser welding equipment, thereby enabling strict control of the welding trajectory between the current collector plate 20 and the tab of the electrode assembly, ensuring better over-current capacity of the battery cells in the electrode assembly, and further contributing to improving the use reliability of the energy storage device 100.

[0048] In this embodiment, the liquid injection hole 25 penetrates the current collector plate 20 in the thickness direction of the current collector plate 20, and is spaced apart from both the through hole 24 and the welding groove 23. Specifically, the opening of the liquid injection hole 25 is located on the surface of the boss portion 22 facing away from the main body portion 21. The liquid injection hole 25 is recessed from the surface of the boss portion 22 facing away from the main body portion 21 towards the main body portion 21, and penetrates the surface of the main body portion 21 facing away from the cover plate 10, and communicates with the receiving cavity of the housing 110. Among them, the central axis (not shown in the figure) of the liquid injection hole 25 coincides with the central axis of the current collector plate 20. It can be understood that the electrolyte can be injected into the receiving cavity through the liquid injection hole 25 to realize the perfusion of the electrolyte of the energy storage device 100. Since the central axis of the liquid injection hole 25 coincides with the central axis of the current collector plate 20, the electrolyte can quickly infiltrate from the central position of the electrode assembly to improve the infiltration effect of the electrode assembly in the electrolyte.

[0049] The liquid injection hole 25 includes a stepped portion 251 and a liquid injection portion 252. The liquid injection portion 252 is located on one side of the stepped portion 251 facing the main body portion 21 of the current collector plate 20 and communicates with the stepped portion 251. Among them, both the liquid injection portion 252 and the stepped portion 251 are circular holes. The stepped portion 251 is recessed from the surface of the boss portion 22 facing away from the main body portion 21 towards the main body portion 21, and the aperture of the stepped portion 251 gradually decreases in the recessed direction. That is to say, the stepped portion 251 is a tapered hole to facilitate the introduction of the liquid injection head of the liquid injection equipment. The liquid injection portion 252 is recessed from the surface of the main body portion 21 facing away from the boss portion 22 towards the stepped portion 251 and penetrates the bottom wall of the stepped portion 251. Among them, the aperture of the liquid injection portion 252 is smaller than the aperture of the stepped portion 251.

[0050] In addition, the end cover assembly 120 may further include a sealing member (not shown in the figure), and the sealing member seals the liquid injection hole 25. The shape of the sealing member is the same as the shape of the liquid injection hole 25, so as to realize the sealing of the liquid injection hole 25.

[0051] Please refer to Figure 4 and Figure 7 , Figure 7 is Figure 3 the schematic structural diagram of the cover plate 10 in the end cover assembly 120 shown.

[0052] In this embodiment, the cover plate 10 is sleeved on the boss portion 22 of the current collector plate 20 and is disposed opposite to the main body portion 21. Exemplarily, the cover plate 10 is generally in a disc shape. The cover plate 10 includes a first surface 11 and a second surface 12, and the first surface 11 and the second surface 12 are disposed opposite to each other along the thickness direction of the cover plate 10. Specifically, the first surface 11 is the side of the cover plate 10 facing the current collector plate 20, and the second surface 12 is the side of the cover plate 10 facing away from the current collector plate 20.

[0053] The cover plate 10 is further provided with a mounting hole 14, an explosion-proof hole 15, a mounting sink 16, a first assembly sink 17, a second assembly sink 18, and a groove 19. Among them, both the mounting hole 14 and the explosion-proof hole 15 penetrate through 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 spaced apart from each other. Among them, the mounting hole 14 is disposed in the middle area of the cover plate 10 and is used for mounting the current collector 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 communicated with the second sub-hole 142. Along the direction from the current collector 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 extending direction of the explosion-proof hole 15 is perpendicular to the radial direction of the cover plate 10. In addition, the central plane of the explosion-proof hole 15 passes through the explosion-proof hole 15 along the width direction of the explosion-proof hole 15. That is, the explosion-proof hole 15 is mirror-symmetrical about the central plane of the explosion-proof hole 15.

[0054] Both the first assembly sink 17 and the second assembly sink 18 are disposed around the explosion-proof hole 15 and are both communicated with the explosion-proof hole 15. Along the thickness direction of the cover plate 10, the first assembly sink 17 and the second assembly sink 18 are disposed opposite to each other. Specifically, the opening of the first assembly sink 17 is located on the first surface 11. The first assembly sink 17 is recessed from the first surface 11 towards the second surface 12 and penetrates through the hole wall surface of the explosion-proof hole 15 to communicate with the explosion-proof hole 15. The first assembly sink 17 is used for mounting the explosion-proof valve 30. The opening of the second assembly sink 18 is located on the second surface 12. The second assembly sink 18 is recessed from the second surface 12 towards the first surface 11 and penetrates through the hole wall surface of the explosion-proof hole 15 to communicate with the explosion-proof hole 15. The second assembly sink 18 is used for mounting the protection member 40.

[0055] The openings of the mounting sink 16 and the groove 19 are both located on the second surface 12, and both the mounting sink 16 and the groove 19 are recessed from the second surface 12 towards the first surface 11. Specifically, the mounting sink 16 is arranged around the mounting hole 14 and penetrates through the hole wall surface of the mounting hole 14 to communicate with the mounting hole 14. That is to say, the mounting sink 16 is spaced apart from the explosion-proof hole 15, the first assembly sink 17, and the second assembly sink 18. In this embodiment, the groove 19 is spaced apart from the mounting sink 16, the mounting hole 14, the explosion-proof hole 15, the first assembly sink 17, and the second assembly sink 18. Exemplarily, there are multiple grooves 19. The multiple grooves 19 are arranged at intervals around the explosion-proof hole 15.

[0056] Please refer to Figure 4 、 Figure 8 and Figure 9 , Figure 8 is Figure 7 a schematic structural view of the cover plate 10 shown in another angle, Figure 9 is Figure 8 a schematic cross-sectional structural view of the cover plate 10 shown in Figure 10 after being cut along the C-C.

[0057] A limiting protrusion 13 is provided on the surface of the cover plate 10 facing the main body portion 21. That is to say, the limiting protrusion 13 is arranged on the first surface 11 of the cover plate 10. The limiting protrusion 13 protrudes in the direction away from the first surface 11 along the thickness direction of the cover plate 10. The limiting protrusion 13 can be used to abut against the current collector plate 20 to realize the limitation of the current collector plate 20. Specifically, the limiting protrusion 13 is arranged 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 to say, 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 within the groove 19.

[0058] In this embodiment, the limiting protrusion 13 can be formed by stamping the cover plate 10 from the second surface 12 towards the first surface 11, and the groove 19 is formed on the second surface 12, that is, the limiting protrusion 13 and the groove 19 are formed simultaneously in one stamping process, so as to simplify the manufacturing process of the cover plate 10 and reduce the production cost of the cover plate 10.

[0059] In this embodiment, there are multiple limiting protrusions 13. The multiple limiting protrusions 13 are arranged around the circumferential side of the explosion-proof hole 15 and are spaced apart from each other. Among them, the multiple limiting protrusions 13 are mirror-symmetrical about the central plane of the explosion-proof hole 15. Exemplarily, the distance between the center of each limiting protrusion 13 and the central plane of the explosion-proof hole 15 is equal. Along the thickness direction of the cover plate 10, each groove 19 is arranged opposite to a limiting protrusion 13. That is to say, 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 within a groove 19. Specifically, there are four limiting protrusions 13. The four limiting protrusions 13 can be divided into two groups. The two groups of limiting protrusions 13 are on the opposite sides with respect to the central plane of the explosion-proof hole 15. Each group includes two limiting protrusions 13. The two limiting protrusions 13 in each group are spaced apart from each other.

[0060] Please refer to Figure 3 and Figure 10 , Figure 10 which Figure 8 is a schematic structural diagram of the assembled cover plate 10 and the explosion-proof valve 30 as shown.

[0061] In this embodiment, both the explosion-proof valve 30 and the protection member 40 are in the shape of a waist-shaped sheet. Among them, the extending direction of the explosion-proof valve 30 is parallel to the extending 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 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 burst under the action of the air pressure, so that the gas inside the energy storage device 100 can be discharged to the outside of the energy storage device 100 in time, avoiding the explosion of the energy storage device 100 due to excessive internal air pressure, thereby improving the use reliability of the energy storage device 100 and extending the service life of the energy storage device 100.

[0062] In addition, the explosion-proof valve 30 includes a central plane 301. The central plane 301 passes through the explosion-proof valve 30 along the width direction of the explosion-proof valve 30. That is to say, the explosion-proof valve 30 is mirror-symmetrical about the central plane 301. When the explosion-proof valve 30 is installed on the cover plate 10, the multiple limiting protrusions 13 of the cover plate 10 are mirror-symmetrical about the central plane 301 of the explosion-proof valve 30. Exemplarily, the distance between the center of each limiting protrusion 13 and the plane where the circumferential surface of the explosion-proof valve 30 is located is equal.

[0063] In this setting, when the gas inside the energy storage device 100 impacts the current collector plate 20, by making the multiple limiting protrusions 13 mirror-symmetrical about the central plane 301 of the explosion-proof valve 30, the cover plate 10 can be kept balanced, avoiding the explosion-proof valve 30 from being blocked due to the inclination of the cover plate 10 towards the current collector plate 20, so as to ensure that the gas inside the energy storage device 100 can smoothly impact the explosion-proof valve 30 and ensure the normal valve opening and pressure relief of the explosion-proof valve 30.

[0064] The protection member 40 is installed in the second assembly sinking groove 18 of the cover plate 10 and covers the explosion-proof hole 15. Exemplarily, the protection member 40 can be welded to the groove wall of the second assembly sinking groove 18. The protection member 40 is used to protect the explosion-proof valve 30, avoiding damage to the explosion-proof valve 30 caused by the external environment and external forces, thereby preventing the explosion-proof valve 30 from being accidentally touched and ensuring good reliability in the use of the energy storage device 100.

[0065] Please refer to again Figure 4 In the assembled end cover assembly 120, the boss portion 22 of the current collector plate 20 passes through the mounting hole 14 of the cover plate 10, and the liquid 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 liquid 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. With this setting, the cover plate 10 and the main body portion 21 of the current collector plate 20 can be spaced apart, and an air flow channel is formed between the cover plate 10 and the main body portion 21 of the current collector plate 20 for the gas inside the energy storage device 100 to flow. Exemplarily, the bottom wall surface of the mounting sinking groove 16 of the cover plate 10 is located on the side where the surface of the boss portion 22 facing away from the main body portion 21 faces the main body portion 21.

[0066] The second step portion 222 of the boss portion 22 passes through the mounting hole 14. Among them, 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 circumferential 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 passes through 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, facilitating the alignment and installation between the current collector plate 20 and the cover plate 10 and helping to reduce the precision requirements of the installation process.

[0067] The cover plate 10 is installed on the side of the first surface 211 of the main body 21 of the current collector plate 20 that faces away from the second surface 212. In the thickness direction of the end cover assembly 120, the explosion-proof hole 15 of the cover plate 10 is arranged in a dislocation manner with the welding groove 23 and is arranged opposite to the through hole 24. In the thickness direction of the end cover assembly 120, the limiting protrusion 13 of the cover plate 10 is arranged opposite to the main body 21 of the current collector plate 20 and is arranged in a dislocation manner with both the explosion-proof valve 30 and the welding groove 23 on the current collector plate 20. In this embodiment, in the thickness direction of the end cover assembly 120, the projections of the limiting protrusion 13 and the explosion-proof valve 30 on the main body 21 of the current collector plate 20 are both located between two adjacent welding grooves 23. That is to say, in 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 arranged in a dislocation manner with each welding groove 23 of the current collector plate 20, so that the explosion-proof hole 15 communicates with the inside of the energy storage device 100 through the through hole 24 of the current collector plate 20, thereby realizing exhaust pressure relief.

[0068] It can be understood that when the gas inside the energy storage device 100 impacts the current collector plate 20, the limiting protrusion 13 can abut against the main body 21 of the current collector plate 20 to limit the main body 21 of the current collector plate 20 and restrict the movement of the current collector plate 20 in the direction of the cover plate 10. On the one hand, it can prevent the current collector plate 20 from blocking the explosion-proof valve 30 installed on the cover plate 10, so as to ensure that the explosion-proof valve 30 can normally open the valve to relieve pressure when the energy storage device 100 has a thermal runaway. On the other hand, it can ensure that the air flow channel between the cover plate 10 and the main body 21 of the current collector plate 20 will not be blocked due to the movement of the current collector plate 20 in the direction of the cover plate 10, so as to ensure that the gas inside the energy storage device 100 can flow through the air flow channel and impact the explosion-proof valve 30, so that the explosion-proof valve 30 can normally open the valve to relieve pressure when the energy storage device 100 has a thermal runaway, which helps to ensure that the energy storage device 100 has better use reliability.

[0069] The present application also provides an electrical equipment, which includes the above-mentioned energy storage device 100, and the energy storage device 100 supplies power to the electrical equipment. Among them, the electrical equipment can be an electric vehicle, a storage power station, a server and other equipment that requires electricity.

[0070] The above description is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art in the technical field disclosed by the present application can easily think of changes or substitutions, which should be covered within the protection scope of the present application; without conflict, the implementation manners and features in the implementation manners of the present application can be combined with each other. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A current collecting plate for an energy storage device, characterized in that: The current collecting plate includes a first surface and a second surface. The first surface and the second surface are arranged back to back along the thickness direction of the current collecting plate. The current collecting plate is also provided with a welding groove and a stress release hole. The opening of the welding groove is located on the first surface. The welding groove includes a groove bottom wall and a first groove side wall close to the center of the current collecting plate. The first groove side wall is fixedly connected between the groove bottom wall and the first surface. Along the thickness direction of the current collecting plate, the stress release hole passes through the first surface, the second surface and the first groove side wall.

2. The collecting plate according to claim 1, characterized in that: The welding groove further includes two second groove side walls, both of which are fixedly connected between the groove bottom wall and the first surface, and along the width direction of the welding groove, the two second groove side walls are respectively connected to opposite sides of the first groove side wall; Along the thickness direction of the current collecting plate, the stress release hole also penetrates through a side wall of the second groove.

3. The collecting plate according to claim 2, characterized in that: There are a plurality of welding grooves and a plurality of stress release holes, and every two stress release holes penetrate through the first groove side wall of one welding groove and respectively penetrate through two second groove side walls of one welding groove.

4. The collecting plate according to any one of claims 1 to 3, characterized in that: The ratio of the cross-sectional area of ​​the stress release hole to the area of ​​the bottom wall of the welding groove is between 0.0083 and 0.0589.

5. The collecting plate according to claim 3, characterized in that: The current collecting plate is further provided with a positioning notch, and the positioning notch penetrates the first surface, the second surface and the peripheral side surface of the current collecting plate along the thickness direction of the current collecting plate, and is spaced apart from the welding groove.

6. The collecting plate according to claim 5, characterized in that: There are a plurality of positioning notches, and each positioning notch is located between two adjacent welding grooves.

7. An end cap assembly, characterized in that: The invention comprises a cover plate and the collecting plate according to any one of claims 1 to 6, wherein the cover plate is mounted on a side of the first surface facing away from the second surface.

8. The end cap assembly according to claim 7, characterized in that: The current collecting plate includes a main body and a boss portion, the main body includes the first surface and the second surface, the main body is further provided with a through hole, the welding groove and the stress release hole, the through hole penetrates the first surface and the second surface along the thickness direction of the main body, and is spaced apart from the welding groove and the stress release hole, the boss portion is provided on the first surface, and is spaced apart from the welding groove and the stress release hole; The cover plate is sleeved on the boss portion and arranged opposite to the main body portion. The cover plate is provided with an explosion-proof hole, which penetrates the cover plate along the thickness direction of the cover plate. Along the thickness direction of the end cover assembly, the explosion-proof hole is staggered with the welding groove and arranged opposite to the through hole. A limiting protrusion is provided on the surface of the cover plate facing the main body portion. The limiting protrusion is spaced apart from the explosion-proof hole. Along the thickness direction of the end cover assembly, the limiting protrusion is staggered with the welding groove and the through hole. The end cover assembly further includes an explosion-proof valve, which is mounted on the cover plate and covers the explosion-proof hole.

9. 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 8, 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.

10. An electrical device, characterized in that: It includes the energy storage device as described in claim 9, and the energy storage device supplies power to the electrical equipment.

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