Cover plate, end cover assembly, energy storage device and electric equipment

Abstract

According to the cover plate, the end cover assembly, the energy storage device and the electric equipment, an exhaust channel of an anti-explosion valve can be prevented from being blocked, it is guaranteed that the anti-explosion valve can be opened in time to release pressure when thermal runaway happens to the energy storage device, and therefore the safety of the energy storage device can be improved. The cover plate comprises a first surface and a second surface, the first surface and the second surface are oppositely arranged in the thickness direction of the cover plate, the cover plate is provided with an anti-explosion hole, a first exhaust groove and a second exhaust groove, the anti-explosion hole penetrates through the first surface and the second surface, and openings of the first exhaust groove and the second exhaust groove are both located in the first surface. The first exhaust groove is formed around the peripheral side of the anti-explosion hole and communicates with the anti-explosion hole, and the second exhaust groove is located in one side of the first exhaust groove and penetrates through the peripheral side face of the cover plate and the groove side wall face of the first exhaust groove.

Description

Technical Field

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

[0002] Energy storage devices, such as secondary batteries, are widely used as a primary power source for electrical equipment due to their recyclable nature. As demand for energy storage devices grows, so too do expectations for their performance across all aspects. When a thermal runaway occurs in an energy storage device, the collector plate can deform and block the exhaust passage of the explosion-proof valve, preventing the valve from opening and releasing pressure, thus compromising the safety of the energy storage device. Utility Model Content

[0003] The present application provides a cover plate, an end cover assembly, an energy storage device, and an electrical device, which can prevent the exhaust channel of the explosion-proof valve from being blocked, and ensure that the explosion-proof valve can open 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 use in an energy storage device. The cover plate includes a first surface and a second surface, the first surface and the second surface being disposed opposite each other along the thickness direction of the cover plate. The cover plate is provided with an explosion-proof hole, a first exhaust groove, and a second exhaust groove. The explosion-proof hole passes through the first surface and the second surface, the openings of the first exhaust groove and the second exhaust groove are both located on the first surface, the first exhaust groove is disposed around the circumference of the explosion-proof hole and is in communication with the explosion-proof hole, and the second exhaust groove is located on one side of the first exhaust groove and passes through the circumferential side surface of the cover plate and the groove side wall of the first exhaust groove.

[0005] There are a plurality of second exhaust grooves, and the plurality of second exhaust grooves are spaced apart from each other.

[0006] In which, the cover plate is also provided with a mounting hole and a third exhaust groove, the mounting hole passes through the first surface and the second surface, the mounting hole is located on the side of the first exhaust groove away from the second exhaust groove, and is spaced apart from the first exhaust groove, the opening of the third exhaust groove is located on the first surface, the third exhaust groove is located on the side of the first exhaust groove away from the second exhaust groove, and is arranged around the circumference of the mounting hole and is connected to the first exhaust groove.

[0007] Among them, the ratio d1 / D of the inner diameter d1 of the third exhaust groove and the diameter D of the cover plate is 0.5<d1 / D<1; the ratio d2 / D of the outer diameter d2 of the third exhaust groove and the diameter D of the cover plate is 0.5<d2 / D<1.

[0008] In which, the cover plate is also provided with a fourth exhaust groove, the opening of the fourth exhaust groove is located on the first surface, the fourth exhaust groove is located between the mounting hole and the third exhaust groove, and is spaced apart from the mounting hole and the third exhaust groove, and is arranged around the circumference of the mounting hole, and is also connected to the first exhaust groove.

[0009] In a second aspect, the present application further provides an end cover assembly, comprising an explosion-proof valve and a cover plate as described above, wherein the explosion-proof valve is mounted on the cover plate, covers the explosion-proof hole, and is spaced apart from the side wall of the first exhaust groove.

[0010] In which, the end cover assembly also includes a collecting plate, which includes a main body and a boss portion. The main body is located on the side of the first surface away from the second surface. The main body is provided with at least one through hole, and at least one through hole passes through the main body along the thickness direction of the main body and is arranged opposite to the explosion-proof valve. The boss portion is connected to the surface of the main body facing the cover plate; the cover plate is sleeved on the boss portion, and the first surface and the main body are spaced apart.

[0011] In which, the boss portion includes a first step portion and a second step portion, the first step portion is fixedly connected to the surface of the main body portion facing the cover plate, and the second step portion is fixedly connected to the surface of the first step portion facing away from the main body portion; the cover plate is sleeved on the second step portion, and the first surface abuts against the surface of the first step portion facing away from the main body portion.

[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 second exhaust groove connects the first exhaust groove and the receiving cavity.

[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] In the technical solution provided by the present application, a first exhaust groove and a second exhaust groove are provided on the cover plate, and the second exhaust groove is made to penetrate the peripheral side surface of the cover plate and the groove side wall surface of the first exhaust groove, so that the explosion-proof hole and the interior of the energy storage device are connected. On the one hand, when the energy storage device experiences thermal runaway, even if the collecting plate is deformed by the impact of the gas inside the energy storage device and fits with the cover plate, the second exhaust groove will not be completely blocked. The gas inside the energy storage device can still flow into the first exhaust groove through the second exhaust groove and converge under the explosion-proof valve, thereby preventing the exhaust passage between the explosion-proof valve and the collecting plate from being blocked by the deformed collecting plate, ensuring that the explosion-proof valve can open and release pressure in time when the energy storage device experiences thermal runaway, thereby improving the safety of the energy storage device. On the other hand, there is no need to provide a protrusion on the first surface of the cover plate to ensure that the exhaust passage between the collecting plate and the explosion-proof valve is unobstructed. During the production process of the end cover assembly, when multiple cover plates are stacked, the protrusion on one cover plate can be prevented from scratching the second surface of another cover plate, thereby helping to improve the appearance of the end cover assembly. At the same time, when the explosion-proof valve is welded to the cover plate, this setting can also prevent the protrusion on one cover plate from crushing the explosion-proof valve welded on the other cover plate, thereby also helping to reduce the product defective rate of the end cover assembly. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0016] Figure 1 This is a schematic diagram of the structure of the energy storage device provided in an embodiment of the present application;

[0017] Figure 2 yes Figure 1 A schematic structural diagram of the end cover assembly in the energy storage device shown;

[0018] Figure 3 yes Figure 2 A schematic diagram of the exploded structure of the end cap assembly shown;

[0019] Figure 4 yes Figure 2 The cross-sectional structure diagram of the end cover assembly shown is taken along AA;

[0020] Figure 5 yes Figure 3 A schematic structural diagram of the cover plate in the end cover assembly shown;

[0021] Figure 6 yes Figure 5 A schematic diagram of the structure of the cover plate shown at another angle;

[0022] Figure 7 yes Figure 6 The cross-sectional structure diagram of the cover plate shown is after being cut along BB;

[0023] Figure 8 yes Figure 5 A schematic structural diagram of the cover plate shown at another angle;

[0024] Figure 9 yes Figure 3 A schematic diagram of the structure of the collecting plate in the end cover assembly shown;

[0025] Figure 10 yes Figure 9 The cross-sectional structure diagram of the collecting plate after being cut along CC is shown;

[0026] Figure 11 This is a structural diagram of an electrical device provided in this application.

[0027] The names corresponding to the reference numerals in the figures are:

[0028] Energy storage device 100, shell 110, end cover assembly 120, cover plate 10, collecting plate 20, explosion-proof valve 30, protective sheet 40, first surface 11, second surface 12, peripheral side surface 13, mounting hole 14, explosion-proof hole 15, mounting groove 16, first assembly groove 17, second assembly groove 18, first exhaust groove 101, second exhaust groove 102, third exhaust groove 103, fourth exhaust groove 104, first sub-hole 141, second sub-hole 142, 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, step portion 251, injection portion 252, electrical equipment 1000, electric energy conversion device 200, user load 300. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application.

[0030] See also Figure 1 , Figure 1 Schematic diagram of the structure of the energy storage device 100 provided in an embodiment of the present application.

[0031] 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. 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. The electrode assembly includes a battery cell (not shown) and a tab (not shown). The tab 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.

[0032] Please refer to Figure 2 、 Figure 3 and Figure 4 , Figure 2 yes Figure 1 The schematic structural diagram 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. Figure 4 yes Figure 2 The cross-sectional structure diagram of the end cap assembly 120 is shown after being cut along line AA, wherein "cut along line AA" means cutting along the plane where line AA is located.

[0033] The end cap assembly 120 includes a cover plate 10, a current collecting disc 20, an explosion-proof valve 30 and a protective sheet 40. The current collecting disc 20 is mounted on the inner side of the shell 110 and is electrically connected to the electrode tab of the electrode assembly. Exemplarily, the current collecting disc 20 can be electrically connected to the electrode tab of the electrode assembly by welding. The cover plate 10 is mounted on one side of the current collecting disc 20 in the thickness direction. The explosion-proof valve 30 and the protective sheet 40 are both mounted on the cover plate 10 and are spaced apart from the current collecting disc 20. Along the thickness direction of the end cap assembly 120, the explosion-proof valve 30 and the protective sheet 40 are arranged opposite to each other.

[0034] Please refer to Figure 5 、 Figure 6 and Figure 7 , Figure 5 yes Figure 3 The structural diagram of the cover plate 10 in the end cover assembly 120 is shown. Figure 6 yes Figure 5 The structural diagram of the cover plate 10 shown in FIG. 1 is shown in FIG. 1 from another angle. Figure 7 yes Figure 6 The cross-sectional structure diagram of the cover plate 10 is shown after it is cut along BB.

[0035] In this embodiment, the cover plate 10 is roughly disc-shaped. The cover plate 10 includes a first surface 11, a second surface 12 and a peripheral side surface 13. Among them, along the thickness direction of the cover plate 10, the first surface 11 and the second surface 12 are arranged back to back. Specifically, the first surface 11 is the side of the cover plate 10 facing the shell 110, and the second surface 12 is the side of the cover plate 10 away from the shell 110. The peripheral side surface 13 is fixedly connected between the first surface 11 and the second surface 12. In the direction from the first surface 11 to the second surface 12, the distance between at least part of the peripheral side surface 13 and the second surface 12 gradually decreases. That is, at least part of the peripheral side surface 13 is inclined. Under this setting, the peripheral side surface 13 of the cover plate 10 can play a guiding role, which facilitates the assembly of the cover plate 10 and the shell 110 of the energy storage device 100.

[0036] 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, a first exhaust groove 101, a second exhaust groove 102, a third exhaust groove 103 and a fourth exhaust groove 104. Among them, the mounting hole 14 and the explosion-proof hole 15 both pass 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 arranged at intervals from each other. Among them, the mounting hole 14 is provided 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. The aperture of the first sub-hole 141 gradually decreases from the first surface 11 to the second surface 12.

[0037] In this embodiment, the openings of the first exhaust groove 101, the second exhaust groove 102, the third exhaust groove 103 and the fourth exhaust groove 104 are all located on the first surface 11 of the cover plate 10. The first exhaust groove 101, the second exhaust groove 102, the third exhaust groove 103 and the fourth exhaust groove 104 are all recessed from the first surface 11 to the second surface 12. The first exhaust groove 101 is arranged around the circumference of the explosion-proof hole 15 and is connected to the explosion-proof hole 15. The first exhaust groove 101 is also spaced apart from the mounting hole 14. Under this arrangement, the gas inside the energy storage device 100 can flow into the first exhaust groove 101 and then gather under the explosion-proof hole 15, thereby ensuring that the explosion-proof valve 30 can open in time when thermal runaway occurs in the energy storage device 100, thereby improving the safety of the energy storage device 100.

[0038] The second exhaust groove 102 is located on one side of the first exhaust groove 101, and passes through the peripheral side surface 13 of the cover plate 10 and the groove side wall surface of the first exhaust groove 101, so that the first exhaust groove 101 and the external environment of the cover plate 10 are connected, thereby connecting the explosion-proof hole 15 to the external environment of the cover plate 10. Specifically, the second exhaust groove 102 is located on the side of the first exhaust groove 101 away from the mounting hole 14. When the end cover assembly 120 is installed to the shell 110, the second exhaust groove 102 also connects the first exhaust groove 101 and the receiving cavity of the shell 110, so that the gas in the receiving cavity can flow into the first exhaust groove 101 through the second exhaust groove 102 and gather below the explosion-proof hole 15, so that the gas can be discharged smoothly when thermal runaway occurs in the energy storage device 100. In this embodiment, there can be multiple second exhaust grooves 102. The multiple second exhaust grooves 102 are arranged at intervals from each other. Under this configuration, the amount of gas entering the first exhaust slot 101 from the second exhaust slot 102 can be increased, further improving the exhaust and ventilation effects of the second exhaust slot.

[0039] It can be understood that by arranging the first exhaust groove 101 and the second exhaust groove 102 on the cover plate 10, and making the second exhaust groove 102 penetrate the peripheral side surface 13 of the cover plate 10 and the groove side wall surface of the first exhaust groove 101, when the energy storage device 100 has thermal runaway, even if the collecting plate 20 is deformed under the impact of the gas inside the energy storage device 100 and fits with the cover plate 10, the second exhaust groove 102 will not be completely blocked by the deformed collecting plate 20. The second exhaust groove 102 can still play the role of exhaust and ventilation, ensuring that the gas inside the energy storage device 100 can smoothly flow into the first exhaust groove 101 through the second exhaust groove 102, and converge to the bottom of the explosion-proof hole 15, and then be smoothly discharged through the explosion-proof hole 15, thereby ensuring that the exhaust channel inside the energy storage device 100 is smooth, which is conducive to improving the safety of the energy storage device 100.

[0040] The third exhaust groove 103 and the fourth exhaust groove 104 are both located on a side of the first exhaust groove 101 away from the second exhaust groove 102, are both arranged around the circumference of the mounting hole 14, and are both connected to the first exhaust groove 101. Specifically, the third exhaust groove 103 is located on a side of the first exhaust groove 101 away from the second exhaust groove 102 and is connected to the first exhaust groove 101, so that the third exhaust groove 103 is connected to the explosion-proof hole 15.

[0041] See also Figure 8 , Figure 8 yes Figure 5 The structure diagram of the cover plate 10 shown is at another angle.

[0042] In this embodiment, the third exhaust groove 103 is an annular groove. The ratio d1 / D of the inner diameter d1 of the third exhaust groove 103 and the diameter D of the cover plate 10 is 0.5<d1 / D<1, and the ratio d2 / D of the outer diameter d2 of the third exhaust groove 103 and the diameter D of the cover plate 10 is 0.5<d2 / D<1. For example, the inner diameter d1 of the third exhaust groove 103 is 45mm, the outer diameter d2 of the third exhaust groove 103 is 48mm, and the area of ​​the third exhaust groove 103 is 368mm. 2 .

[0043] With this arrangement, the opening of the third exhaust groove 103 can be made larger. When the energy storage device 100 experiences thermal runaway, even if the collecting plate 20 deforms under the impact of the gas inside the energy storage device 100 and fits against the cover plate 10, the third exhaust groove 103 can be prevented from being completely blocked by the deformed collecting plate 20, ensuring that the gas inside the energy storage device 100 can still be collected into the first exhaust groove 101 through the third exhaust groove 103. This effectively solves the problem of gas inside the energy storage device 100 being blocked during thermal runaway, ensures that the exhaust passage of the energy storage device 100 is unobstructed when thermal runaway occurs, and further helps to improve the safety of the energy storage device 100.

[0044] Please refer again Figure 7 In this embodiment, the fourth exhaust slot 104 is located between the mounting hole 14 and the third exhaust slot 103, and is spaced apart from both the mounting hole 14 and the third exhaust slot 103. It is understood that by providing the fourth exhaust slot 104 on the cover plate 10, the smoothness with which the gas inside the energy storage device 100 reaches below the explosion-proof hole 15 can be further improved, thereby ensuring smooth exhaust when the energy storage device 100 experiences thermal runaway.

[0045] Please continue reading Figure 6 and Figure 7 . The first assembly sink 17 and the second assembly sink 18 are both arranged around the explosion-proof hole 15, and are both connected to the explosion-proof hole 15. In this embodiment, the first assembly sink 17 and the second assembly sink 18 are both spaced apart from the mounting hole 14. Along the thickness direction of the cover plate 10, the first assembly sink 17 and the second assembly sink 18 are arranged back to back. Specifically, the opening of the first assembly sink 17 is located on the bottom wall of the first exhaust groove 101. The first assembly sink 17 is recessed from the bottom wall of the first exhaust groove 101 in 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 sink 17 is used to install the explosion-proof valve 30.

[0046] The opening of the second assembly recess 18 is located on the second surface 12. The second assembly recess 18 is recessed from the second surface 12 toward the first surface 11 and penetrates the wall of the explosion-proof hole 15 to communicate with the explosion-proof hole 15. The second assembly recess 18 is used to install the protective sheet 40.

[0047] The opening of mounting recess 16 is located on second surface 12, and recess 16 is recessed from second surface 12 toward first surface 11. Specifically, recess 16 surrounds mounting hole 14 and extends through the wall of mounting hole 14 to communicate with mounting hole 14. In other words, recess 16 is spaced apart from explosion-proof hole 15, first mounting recess 17, and second mounting recess 18.

[0048] Please refer again Figure 3 and Figure 4 . In this embodiment, the explosion-proof valve 30 and the protective sheet 40 are both waist-shaped sheets. Among them, the extension direction of the explosion-proof valve 30 is parallel to the extension direction of the explosion-proof hole 15. Specifically, the explosion-proof valve 30 is installed in the first assembly sink 17 of the cover plate 10, and covers the explosion-proof hole 15, and is spaced apart from the side wall of the first exhaust groove 101 to ensure that the gas inside the energy storage device 100 can flow into the first exhaust groove 101 and then converge to the bottom of the explosion-proof valve 30, thereby ensuring that when the energy storage device 100 has thermal runaway, the gas below the explosion-proof valve 30 can smoothly break through the explosion-proof valve 30, so that the explosion-proof valve can open the valve in time to release pressure. Exemplarily, the length of the explosion-proof valve 30 is 36 mm. The width of the explosion-proof valve 30 is 17.5 mm, and the area of ​​the explosion-proof valve 30 is 372.5 mm 2 .

[0049] It is understandable that when the gas pressure inside the energy storage device 100 is too high, the explosion-proof valve 30 will rupture under the action of the gas pressure, so that the gas inside the energy storage device 100 is discharged to the outside of the energy storage device 100 in a timely manner, thereby preventing the energy storage device 100 from exploding due to excessive internal gas pressure, thereby improving the reliability of the energy storage device 100 and extending the service life of the energy storage device 100.

[0050] A protective sheet 40 is mounted on the second assembly recess 18 of the cover plate 10 and covers the explosion-proof hole 15. For example, the protective sheet 40 can be welded to the wall of the second assembly recess 18. The protective sheet 40 protects the explosion-proof valve 30 from damage caused by the external environment and external forces, thereby preventing accidental activation of the explosion-proof valve 30 and ensuring the reliability of the energy storage device 100.

[0051] Please refer to Figure 4 、 Figure 9 and Figure 10 , Figure 9 yes Figure 3 The schematic structural diagram of the collecting plate 20 in the end cover assembly 120 is shown. Figure 10 yes Figure 9 The cross-sectional structure diagram of the collecting plate 20 is shown after being cut along CC.

[0052] In this embodiment, the collecting disc 20 is made of metal material. Exemplarily, the collecting disc 20 is made of aluminum metal. In this embodiment, the collecting disc 20 is disc-shaped. The central axis of the collecting disc 20 coincides with the central axis of the cover plate 10. Exemplarily, the collecting disc 20 is rotationally symmetric about the central axis. The collecting disc 20 includes a main body 21 and a boss portion 22. In this 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 using a stamping process.

[0053] Specifically, the main body 21 is located on the side of the first surface 11 of the cover plate 10 that faces away from the second surface 12. The main body 21 includes a first surface 211 and a second surface 212. The first surface 211 and the second surface 212 are disposed opposite 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 facing away from the cover plate 10.

[0054] The boss portion 22 is fixedly connected to the surface of the main body 21 facing the cover plate 10. That is, 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 to 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 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 circumferential surface of the first step portion 221 is arranged around the circumferential surface of the second step portion 222, and protrudes relative to the circumferential surface of the second step portion 222. The surface of the second step portion 222 facing away from the first step portion 221 (not marked in the figure) is the surface of the boss portion 22 facing away from the main body 21.

[0055] In this embodiment, the second stepped 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 stepped portion 221 facing away from the main 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 portion 21. The size of the first sub-portion 222a gradually decreases along the direction from the main portion 21 to the boss portion 22.

[0056] The current collecting plate 20 is also provided with a welding groove 23, at least one through hole 24 and a liquid injection hole 25. The welding groove 23 and the at least one through hole 24 are both provided in the main body 21 of the current collecting plate 20. 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 second surface 212, and passes through the peripheral side surface 13 of the main body 21. Exemplarily, the welding groove 23 is in the shape of an elongated strip, extends in the radial direction of the main body 21, and passes through the peripheral side surface 13 of the current collecting plate 20. The bottom wall of the welding groove 23 protrudes from the main body 21 in a direction away from the boss portion 22. The bottom wall of the welding groove 23 is used to be welded to the tab of the electrode assembly to achieve electrical connection between the electrode assembly and the current collecting plate 20.

[0057] It can be understood that the bottom wall 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 collecting plate 20 and the pole ear of the electrode assembly, so that the collecting plate 20 is in close contact with the pole ear, which can avoid cold welding and ensure the welding strength between the collecting plate 20 and the pole ear of the electrode assembly, and can also improve the consistency of laser welding between the pole ear and the collecting plate 20.

[0058] In this embodiment, there may be multiple welding slots 23, spaced apart around the central axis of the current collecting plate 20 to ensure stable welding between the main body 21 of the current collecting plate 20 and the tabs of the electrode assembly. For example, there are three welding slots 23. In other embodiments, there may be one, two, or more than four welding slots 23. This embodiment of the present application does not impose any specific limitation on the number of welding slots 23.

[0059] At least one through hole 24 passes through the collecting plate 20 along the thickness direction of the collecting plate 20. Specifically, the main body 21 of the collecting plate 20 is provided with at least one through hole 24, and at least one through hole 24 passes through the main body 21 along the thickness direction of the main body 21. In this embodiment, the through hole 24 is spaced apart from the welding groove 23. Exemplarily, the through hole 24 is a circular hole. In some other embodiments, the through hole 24 may also be a square hole or other special-shaped hole. In this embodiment, there are multiple through holes 24. The multiple through holes 24 are arranged at intervals from each other. Among them, the multiple through holes 24 form three through hole groups (not marked in the figure), and the three through hole groups are spaced apart from each other around the central axis of the 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.

[0060] In this embodiment, the injection hole 25 penetrates the collecting tray 20 along the thickness direction of the collecting tray 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 facing away from the main body portion 21. The injection hole 25 is recessed from the surface of the boss portion 22 facing away from the main body portion 21 toward the main body portion 21, penetrates the surface of the main body portion 21 facing away from the cover plate 10, and communicates with the receiving cavity of the shell 110. The central axis of the injection hole 25 (not shown) coincides with the central axis of the collecting tray 20. It is understood that the electrolyte can be injected into the receiving cavity through the injection hole 25 to achieve electrolyte perfusion of the energy storage device 100. Since the central axis of the injection hole 25 coincides with the central axis of the collecting tray 20, the electrolyte can quickly infiltrate from the center of the electrode assembly, thereby improving the infiltration effect of the electrode assembly in the electrolyte. In addition, the end cap assembly 120 may also include a seal (not shown) that seals the injection hole 25. The shape of the sealing member is the same as that of the liquid injection hole 25 , thereby achieving sealing of the liquid injection hole 25 .

[0061] Specifically, 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. 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. In other words, the step portion 251 is a conical hole to facilitate the introduction of the injection head of the injection equipment. 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. The aperture of the injection portion 252 is smaller than the aperture of the step portion 251.

[0062] Please refer again Figure 4 In the assembled end cap assembly 120, the boss portion 22 of the 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. For example, 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 main body 21, so that the injection hole 25 on the boss portion 22 can be exposed relative to the mounting hole 14 of the cover plate 10.

[0063] Specifically, the surface of the first step 221 of the boss 22 facing the second step 222 abuts the first surface 11 of the cover plate 10. This arrangement allows the cover plate 10 to be spaced apart from the main body 21 of the current collecting tray 20, preventing the main body 21 from blocking the first, second, third, and fourth venting slots 101, 102, 103, and 104 of the cover plate 10 when the energy storage device 100 is not experiencing thermal runaway. This creates an airflow channel between the cover plate 10 and the main body 21 of the current collecting tray 20, allowing gas within the energy storage device 100 to flow and converge below the explosion-proof valve 30. The second step 222 of the boss 22 penetrates the mounting hole 14. The first sub-portion 222a of the second step portion 222 is mounted 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. The second sub-portion 222b of the second step portion 222 is inserted into the second sub-hole 142 of the mounting hole 14. It will be appreciated that by gradually reducing the aperture of the first sub-hole 141 of the mounting hole 14 and 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, thereby facilitating alignment and installation between the collecting tray 20 and the cover plate 10, and helping to reduce the precision requirements of the installation process.

[0064] Furthermore, along the thickness of the end cap assembly 120, the explosion-proof hole 15 of the cover plate 10 is positioned opposite at least one through-hole 24 between two adjacent weld grooves 23, and is also offset relative to each weld groove 23 of the current collecting plate 20. That is, along the thickness of the end cap assembly 120, the explosion-proof valve 30 is positioned opposite at least one through-hole 24. This arrangement allows the explosion-proof hole 15 to communicate with the interior of the energy storage device 100 via the through-hole 24 of the current collecting plate 20, facilitating the impact of gas inside the energy storage device 100 on the explosion-proof valve 30, thereby achieving exhaust and pressure relief within the energy storage device 100.

[0065] In the technical solution provided in the present application, a first exhaust groove 101 and a second exhaust groove 102 are provided on the cover plate 10, and the second exhaust groove 102 passes through the peripheral side surface 13 of the cover plate 10 and the groove side wall surface of the first exhaust groove 101, so that the explosion-proof hole 15 and the interior of the energy storage device 100 are connected. On the one hand, when the energy storage device 100 undergoes thermal runaway, even if the collecting plate 20 is deformed and fits with the cover plate 10 under the impact of the gas inside the energy storage device 100, the second exhaust groove 102 will not be completely blocked. The gas inside the energy storage device 100 can still flow into the first exhaust groove 101 through the second exhaust groove 102 and converge under the explosion-proof valve 30, thereby preventing the exhaust channel between the explosion-proof valve 30 and the collecting plate 20 from being blocked by the deformed collecting plate 20, ensuring that the explosion-proof valve 30 can open the valve to release pressure in time when thermal runaway occurs in the energy storage device 100, thereby helping to improve the safety of the energy storage device 100. On the other hand, there is no need to provide a protrusion on the first surface 11 of the cover plate 10 to ensure that the exhaust passage between the collecting plate 20 and the explosion-proof valve 30 is unobstructed. During the production process of the end cap assembly 120, when multiple cover plates 10 are stacked, this can prevent the protrusion on one cover plate 10 from scratching the second surface 12 of another cover plate 10, thereby helping to improve the appearance of the end cap assembly 120. At the same time, when the explosion-proof valve 30 is welded to the cover plate 10, this arrangement can also prevent the protrusion on one cover plate 10 from crushing the explosion-proof valve 30 welded to the other cover plate 10, thereby also helping to reduce the product defect rate of the end cap assembly 120.

[0066] On this basis, by providing a third exhaust groove 103 and a fourth exhaust groove 104 on the cover plate 10, and making the third exhaust groove 103 and the fourth exhaust groove 104 connected to the first exhaust groove 101, the smoothness of the exhaust channel between the collecting plate 20 and the explosion-proof valve 30 can be further improved, effectively solving the problem that the internal gas of the energy storage device 100 cannot reach the bottom of the explosion-proof valve 30 when thermal runaway occurs, thereby ensuring that the explosion-proof valve 30 can open the valve and release pressure in time when thermal runaway occurs in the energy storage device 100, which is beneficial to improving the safety of the energy storage device 100.

[0067] See also Figure 11 , Figure 11 It is a structural diagram of an electrical device 1000 provided in this application.

[0068] The present application also provides an electric device 1000, which can be a device that requires electricity, such as a new energy vehicle, a power station, and a server. In this embodiment, the electric device 1000 is a household energy storage device, which can be used in a household energy storage scenario in user-side energy storage. Exemplarily, the electric device 1000 includes the above-mentioned energy storage device 100, an electric energy conversion device 200 (such as a photovoltaic panel), and a user load 300 (such as a street lamp, household appliances, etc.). Figure 11As shown, energy storage device 100 is a small energy storage box that can be mounted on an outdoor wall. In this embodiment, energy storage device 100 provides power to electrical equipment. Specifically, power conversion device 200 can convert solar energy into electrical energy during periods of low electricity prices and store it in energy storage device 100. This energy can then be supplied to user load 300 for use during peak electricity prices or during grid power outages / blackouts, ensuring the normal operation of electrical equipment 1000.

[0069] The above description is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. The embodiments of the present application and the features of the embodiments can be combined with each other unless there is a conflict. Therefore, the scope of protection of the present application shall be based on the scope of protection of the claims.

Claims

1. A cover plate for use in an energy storage device, characterized in that: 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 back to back. The cover plate is provided with an explosion-proof hole, a first exhaust groove and a second exhaust groove. The explosion-proof hole passes through the first surface and the second surface. The openings of the first exhaust groove and the second exhaust groove are both located on the first surface. The first exhaust groove is arranged around the circumference of the explosion-proof hole and is connected to the explosion-proof hole. The second exhaust groove is located on one side of the first exhaust groove and passes through the circumferential side surface of the cover plate and the groove side wall of the first exhaust groove.

2. The cover plate according to claim 1, wherein: There are a plurality of the second exhaust grooves, and the plurality of the second exhaust grooves are spaced apart from each other.

3. The cover plate according to claim 1 or 2, characterized in that: The cover plate is also provided with a mounting hole and a third exhaust groove, the mounting hole passes through the first surface and the second surface, the mounting hole is located on the side of the first exhaust groove away from the second exhaust groove, and is spaced apart from the first exhaust groove, the opening of the third exhaust groove is located on the first surface, the third exhaust groove is located on the side of the first exhaust groove away from the second exhaust groove, and is arranged around the circumference of the mounting hole and is connected to the first exhaust groove.

4. The cover plate according to claim 3, wherein: The ratio d1 / D of the inner diameter d1 of the third exhaust groove and the diameter D of the cover plate is 0.5<d1 / D<1; A ratio d2 / D of an outer diameter d2 of the third exhaust groove and a diameter D of the cover plate is 0.5<d2 / D<1.

5. The cover plate according to claim 3, characterized in that: The cover plate is also provided with a fourth exhaust groove, the opening of the fourth exhaust groove is located on the first surface, the fourth exhaust groove is located between the mounting hole and the third exhaust groove, and is spaced apart from the mounting hole and the third exhaust groove, and is arranged around the circumference of the mounting hole, and is also connected to the first exhaust groove.

6. An end cap assembly, characterized in that: The invention comprises an explosion-proof valve and a cover plate according to any one of claims 1 to 5, wherein the explosion-proof valve is installed on the cover plate, covers the explosion-proof hole, and is spaced apart from the side wall surface of the first exhaust groove.

7. The end cap assembly according to claim 6, wherein: The end cap assembly further includes a current collecting plate, the current collecting plate including a main body and a boss portion, the main body being located on a side of the first surface facing away from the second surface, the main body being provided with at least one through hole, the at least one through hole penetrating the main body along a thickness direction of the main body and being arranged opposite to the explosion-proof valve, the boss portion being connected to a surface of the main body facing the cover plate; The cover plate is sleeved on the boss portion, and the first surface is spaced apart from the main body portion.

8. The end cap assembly according to claim 7, wherein: The boss portion includes a first step portion and a second step portion, the first step portion is fixedly connected to the surface of the main body portion facing the cover plate, and the second step portion is fixedly connected to the surface of the first step portion facing away from the main body portion; The cover plate is sleeved on the second step portion, and the first surface abuts against a surface of the first step portion facing away from the main body portion.

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 6 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 second exhaust groove connects the first exhaust groove and the receiving cavity.

10. An electrical device, characterized in that: The energy storage device according to claim 9 is included, and the energy storage device supplies power to the electrical equipment.

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