End cover, end cover assembly, energy storage apparatus, and electrical device

Abstract

The present application provides an end cover, an end cover assembly, an energy storage apparatus, and an electrical device. The end cover comprises a first surface, a second surface, and a first peripheral side surface, and is provided with a first protrusion and second protrusions. The first protrusion is provided on the first surface, protrudes in a direction away from the second surface, and is spaced apart from the first peripheral side surface. The first protrusion comprises a first upper surface, a first side surface, and a first lower surface. The second protrusions are provided on the first lower surface, protrude in a direction away from the first upper surface, and are spaced apart from the first side surface. There are 2N second protrusions, and in the length direction of the end cover, the 2N second protrusions are spaced apart from each other, N being a positive integer. The end cover is further provided with an explosion-proof hole. In the length direction of the end cover, N second protrusions are provided on each of two opposite sides of the explosion-proof hole, and are spaced apart from the explosion-proof hole.

Description

End caps, end cap assemblies, energy storage devices and electrical equipment

[0001] This application claims priority to Chinese Patent Application No. 202411732201.0, filed on November 29, 2024, entitled “End Cap, End Cap Assembly, Energy Storage Device and Electrical Equipment”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of energy storage technology, and in particular to an end cap, an end cap assembly, an energy storage device, and an electrical device. Background Technology

[0003] As energy storage devices are used more and more widely, an increasing number of safety issues are emerging, raising concerns about their safety during use. Energy storage devices are equipped with explosion-proof valves in their end caps. In the event of thermal runaway, these valves rupture to release gas and prevent an explosion. However, current end caps are not strong enough, which can cause the explosion-proof valves to fail to open during thermal runaway, reducing the safety performance of the energy storage device. Summary of the Invention

[0004] This application provides an end cap, an end cap assembly, an energy storage device, and an electrical device, which enhances the strength of the end cap of the energy storage device, makes the strength of the end cap symmetrical and uniform, ensures that the exhaust channels on both sides of the explosion-proof valve are close, facilitates the opening of the explosion-proof valve in the event of thermal runaway of the energy storage device, and improves the safety performance and reliability of the energy storage device.

[0005] This application provides an end cap, including a first surface, a second surface, and a first peripheral side surface. Along the thickness direction of the end cap, the first surface and the second surface are disposed opposite to each other, and the first peripheral side surface is connected between the first surface and the second surface.

[0006] The end cap is provided with a first convex bud and a second convex bud. The first convex bud is provided on the first surface and protrudes in a direction away from the second surface, and is spaced apart from the first peripheral side surface. The first convex bud includes a first upper surface, a first side surface and a first lower surface. The first upper surface and the first surface face the same direction. The first side surface connects the first upper surface and the first surface. The first lower surface is disposed opposite to the first upper surface. The second convex bud is provided on the first lower surface and protrudes in a direction away from the first upper surface, and is spaced apart from the first side surface. There are 2N second convex buds, which are spaced apart along the length direction of the end cap, where N is a positive integer. The maximum dimension of each second convex bud along the length direction of the end cap is L1, and the maximum dimension of each second convex bud along the width direction of the end cap is L2, where 1.0≤L2 / L1≤3.0;

[0007] The end cap is also provided with an explosion-proof hole. The explosion-proof hole penetrates the first protrusion along the thickness direction of the end cap. Along the length direction of the end cap, there are N second protrusions on opposite sides of the explosion-proof hole, and they are spaced apart from each other.

[0008] This application also provides an energy storage device, the energy storage device including a housing, a cell assembly and an end cap assembly as described in any one of the above, the housing having a receiving cavity and an opening, the receiving cavity being located inside the housing and containing an electrolyte, the opening being located on the top side of the receiving cavity and communicating with the receiving cavity, the cell assembly being housed in the receiving cavity, and the end cap assembly being installed on the housing, closing the opening, and being electrically connected to the cell assembly.

[0009] This application also provides an electrical device, including the energy storage device described above, which is used to supply power to the electrical device.

[0010] The end cap, end cap assembly, energy storage device, and electrical equipment provided in this application increase the strength of the end cap by providing a first and a second protrusion. Furthermore, the rectangular shape and dimensions of the second protrusion ensure good resistance to deformation, and the distance between the second protrusion and the explosion-proof hole further prevents excessive deformation in the explosion-proof valve area under pressure, all of which further increase the strength of the end cap. Moreover, the N second protrusions located on one side of the explosion-proof hole are mirror-symmetrical to the N second protrusions located on the other side of the explosion-proof hole, ensuring symmetrical and uniform strength of the end cap on opposite sides of the explosion-proof valve. This guarantees that the exhaust channels on both sides of the explosion-proof valve are close, facilitating timely valve opening in the event of thermal runaway in the energy storage device, thereby improving the safety performance and reliability of the energy storage device. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0012] Figure 1 is a schematic diagram of the energy storage device structure provided in an embodiment of this application;

[0013] Figure 2 is a schematic diagram of the end cap assembly structure of the energy storage device shown in Figure 1;

[0014] Figure 3 is an exploded structural diagram of the end cap assembly shown in Figure 2;

[0015] Figure 4 is a schematic diagram of the end cap assembly shown in Figure 2 after being cut open along point AA;

[0016] Figure 5 is a structural schematic diagram of the end cap in the first embodiment of the end cap assembly shown in Figure 3;

[0017] Figure 6 is a schematic diagram of the cross-sectional structure of the end cap shown in Figure 5 cut along BB.

[0018] Figure 7 is a schematic diagram of the end cap in the second embodiment of the end cap assembly shown in Figure 3;

[0019] Figure 8 is a structural schematic diagram of the end cap in the third embodiment of the end cap assembly shown in Figure 3;

[0020] Figure 9 is a structural schematic diagram of the lower insulating component in the end cap assembly described in Figure 3;

[0021] Figure 10 is a structural schematic diagram of the lower insulating component shown in Figure 9 from another angle;

[0022] Figure 11 is a schematic diagram of the structure of the lower insulating component shown in Figure 9 after it has been cut open along CC.

[0023] Figure 12 is a schematic cross-sectional view of the end cap assembly shown in Figure 2, cut along point AA.

[0024] Reference numerals: Energy storage device 1000, housing 2000, end cap assembly 3000, opening 2001, end cap 100, explosion-proof valve 200, protective plate 300, lower insulating component 400, pole post 500, pin 600, upper insulating component 700, sealing ring 800, first surface 101, second surface 102, first peripheral side 103, first convex 110, first upper surface 111, first side 112, first lower surface 113, second convex 120, second upper surface 121, second lower surface 12 2. Second side surface 123, first through hole 130, explosion-proof hole 140, first injection hole 150, third surface 401, fourth surface 402, second peripheral side surface 403, third protrusion 410, third upper surface 411, third side surface 412, third lower surface 413, boss 420, second groove 430, bottom wall of groove 431, side wall of groove 432, first groove 440, first vent hole 450, second vent hole 460, third vent hole 470, second through hole 480, second injection hole 490. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0026] Please refer to Figure 1, which is a schematic diagram of the structure of the energy storage device 1000 provided in an embodiment of this application.

[0027] This application provides an energy storage device 1000, which may include, but is not limited to, single-cell batteries, battery modules, battery packs, and battery systems. The actual application form of the energy storage device provided in this application embodiment may be, but is not limited to, the listed products, and may also be other application forms. This application embodiment does not strictly limit the application form of the energy storage device 1000. This application embodiment uses a square battery as an example for illustration.

[0028] The energy storage device 1000 includes a housing 2000, a battery cell assembly (not shown), and an end cap assembly 3000. The housing 2000 has a receiving cavity (not shown) and an opening 2001. The receiving cavity is located inside the housing 2000 and contains electrolyte. The opening 2001 is located on the top side of the receiving cavity and communicates with it. The housing 2000 may be made of aluminum; that is, the housing 2000 may be an aluminum shell. The battery cell assembly is housed in the receiving cavity. The battery cell assembly can be immersed in the electrolyte. The ratio of the length to the width of the battery cell assembly is greater than 4; that is, the battery cell assembly is a large-sized battery cell assembly. The end cap assembly 3000 is mounted on the housing 2000, closes the opening 2001, and is electrically connected to the battery cell assembly.

[0029] Please refer to Figures 2 to 4. Figure 2 is a structural schematic diagram of the end cap assembly 3000 of the energy storage device 1000 shown in Figure 1. Figure 3 is an exploded structural schematic diagram of the end cap assembly 3000 shown in Figure 2. Figure 4 is a structural schematic diagram of the end cap assembly 3000 shown in Figure 2 after being cut open along point AA.

[0030] The end cap assembly 3000 includes an end cap 100, an explosion-proof valve 200, a protective plate 300, a lower insulator 400, a terminal post 500, a lead 600, an upper insulator 700, and a sealing ring 800. The explosion-proof valve 200 and the protective plate 300 are both mounted on the end cap 100. Along the thickness direction of the end cap assembly 3000, the lower insulator 400 is located on one side of the end cap 100. Along the thickness direction of the end cap assembly 3000, the terminal post 500 passes through the end cap 100 and the lower insulator 400. There are two terminal posts 500, arranged at intervals along the length direction of the end cap assembly 3000. One terminal post 500 serves as the positive terminal post, and the other terminal post 500 serves as the negative terminal post. The lead 600 is located on the side of the lower insulator 400 opposite to the end cap 100 and is electrically connected to the terminal post 500 and the tab of the cell assembly. There are two pins 600, each fixedly connected to a terminal 500. One pin 600 serves as the positive pin and is electrically connected to the positive terminal and the positive tab of the cell assembly. The other pin 600 serves as the negative pin and is electrically connected to the negative terminal and the negative tab of the cell assembly. An upper insulating member 700 is installed between the terminal 500 and the end cap 100. There are two upper insulating members 700, each installed between the terminal 500 and the end cap 100. One upper insulating member 700 serves as the positive insulating member and is installed between the positive terminal and the end cap 100. The other upper insulating member 700 serves as the negative insulating member and is installed between the negative terminal and the end cap 100. A sealing ring 800 is fitted onto the upper insulating member 700 and clamped between the end cap 100 and the pin 600. There are two sealing rings 800. Each sealing ring 800 is fitted onto an upper insulating member 700 and clamped between the end cap 100 and a pin 600. One sealing ring 800 serves as the positive electrode sealing ring, fitted onto the positive electrode insulating member and clamped between the end cap 100 and the positive electrode pin. The other sealing ring 800 serves as the negative electrode sealing ring, fitted onto the negative electrode insulating member and clamped between the end cap 100 and the negative electrode pin.

[0031] Please refer to Figures 5 and 6. Figure 5 is a structural schematic diagram of the end cap 100 in the end cap assembly 3000 shown in Figure 3 under a first embodiment. Figure 6 is a cross-sectional structural schematic diagram of the end cap 100 shown in Figure 5 cut along BB.

[0032] In this embodiment, the end cap 100 can be a smooth aluminum sheet made of aluminum. The length of the end cap 100 along the length direction of the end cap assembly 3000 is L. The width of the end cap 100 along the width direction of the end cap assembly 3000 is W. The ratio between the length L and the width W of the end cap 100 is greater than 4. The end cap 100 includes a first surface 101, a second surface 102, and a first peripheral side surface 103. Along the thickness direction of the end cap 100, the first surface 101 and the second surface 102 are arranged opposite to each other. The first peripheral side surface 103 connects the first surface 101 and the second surface 102. It is understood that when the ratio between the length L and the width W of the end cap 100 is greater than 4, the end cap is more prone to deformation. Therefore, how to improve the strength of the end cap through a simple process without sacrificing the energy density of the energy storage device is an urgent problem to be solved.

[0033] The end cap 100 has a first protrusion 110 and a second protrusion 120. The first protrusion 110 is located in the middle of the end cap 100 and is spaced apart from the first peripheral side surface 103. The first protrusion 110 is provided on the first surface 101 and protrudes in a direction away from the second surface 102. The first protrusion 110 includes a first upper surface 111, a first side surface 112, and a first lower surface 113. The first upper surface 111 has the same orientation as the first surface 101 and is spaced apart from the first surface 101. The first side surface 112 surrounds the first protrusion 110 and connects the first upper surface 111 and the first surface 101. The first lower surface 113 is disposed opposite to the first upper surface 111. The distance between the first upper surface 111 and the first lower surface 113 is equal to the distance between the first surface 101 and the second surface 102. For example, the first protrusion 110 is formed by stamping to ensure that the thickness of the first protrusion 110 is equal to the thickness of the end cap 100, ensuring that the first protrusion 110 has sufficient strength, and that the strength of the end cap 100 can be enhanced by setting the first protrusion 110. It is understood that during the stamping process of forming the first protrusion 110, a groove corresponding to the first protrusion 110 will be formed on the end cap 100 at the same time.

[0034] The second convex bulge 120 is disposed on the first convex bulge 110. The second convex bulge 120 is disposed on the first lower surface 113 and protrudes away from the first upper surface 111, and is spaced apart from the first side surface 112. The second convex bulge 120 includes a second upper surface 121, a second lower surface 122, and a second side surface 123. The second upper surface 121 faces the same direction as the first upper surface 111 and is spaced apart from it. The second upper surface 121 is flush with the first surface 101. The second lower surface 122 is spaced apart from the second upper surface 121 and faces away from it. The distance between the second upper surface 121 and the second lower surface 122 is equal to the distance between the first surface 101 and the second surface 102. The second lower surface 122 is flush with the second surface 102, ensuring that the second convex bulge 120 will not interfere with other internal structures of the energy storage device 1000 and cause the energy storage device 1000 to fail, thus improving the safety and reliability of the energy storage device 1000. The second side surface 123 surrounds the second protrusion 120 and connects the second lower surface 122 with the first lower surface 113. There are 2N second protrusions 120, which are spaced apart along the length of the end cap 100, where N is a positive integer.

[0035] In this embodiment, the maximum dimension of each second protrusion 120 along the length direction of the end cap 100 is L1, and the maximum dimension of each second protrusion 120 along the width direction of the end cap 100 is L2. Where 1.0 ≤ L2 / L1 ≤ 3.0, this ensures that the second protrusion 120 has sufficient dimension along the width direction of the end cap 100 without occupying too much space inside the energy storage device 1000. This effectively prevents the end cap 100 from deforming due to negative pressure generated during liquid injection, and reduces the possibility of deformation extending to the explosion-proof valve 200 and causing it to deform. The second protrusion 120 also improves the overall strength of the end cap 100, and in the length or width direction of the end cap 100, it prevents the second protrusion 120 from being too small, leading to stress concentration and thus becoming a weak point in the strength of the end cap 100. For example, the second protrusion 120 is formed by stamping. The thickness of the second protrusion 120 is equal to the thickness of the end cap 100, ensuring that the second protrusion 120 has sufficient strength to enhance the strength of the end cap 100. It is understood that during the stamping process of the second protrusion 120, a corresponding groove is simultaneously formed on the end cap 100. Furthermore, 20mm ≤ L1 ≤ 40mm, 0.3W ≤ L2 ≤ 0.6W, to ensure that the second protrusion 120 has good resistance to deformation without occupying too much internal space of the energy storage device 1000.

[0036] In this embodiment, the second convex 120 is rectangular. The maximum dimension of the second convex 120 along the length direction of the end cap 100 is the length of the second convex 120. The maximum dimension of the second convex 120 along the width direction of the end cap 100 is the width of the second convex 120.

[0037] Please refer to Figure 7, which is a structural schematic diagram of the end cap 100 in the end cap assembly 3000 shown in Figure 3 under a second embodiment.

[0038] The second embodiment differs from the first embodiment in that the second convex bulge 120 is circular. The maximum dimension of the second convex bulge 120 along the length direction of the end cap 100 and the maximum dimension of the second convex bulge 120 along the width direction of the end cap 100 are both the diameter of the second convex bulge 120.

[0039] Please refer to Figure 8, which is a structural schematic diagram of the end cap 100 in the end cap assembly 3000 shown in Figure 3 under a third embodiment.

[0040] The third embodiment differs from the first and second embodiments in that the second convex hull 120 can be hexagonal. In other embodiments, the second convex hull 120 can also be other shapes, which are not specifically limited here.

[0041] It is understandable that by setting a first convex hull 110 and a second convex hull 120, with the first convex hull 110 and the second convex hull 120 protruding in opposite directions, the strength of the end cap 100 can be increased. Furthermore, the maximum dimension L2 of the second convex hull 120 along the width direction of the end cap 100 and the maximum dimension L1 of the second convex hull 120 along the length direction of the end cap 100 satisfy 1.0 ≤ L2 / L1 ≤ 3.0, ensuring that the second convex hull 120 has excellent resistance to deformation, thereby further increasing the strength of the end cap 100. The combination of the first convex hull 110 and the second convex hull 120 forms a two-stage anti-deformation structure, which can further optimize the stress distribution on the end cap 100, reduce stress concentration, and thus reduce the degree of deformation of the end cap 100 under stress.

[0042] The end cap 100 also has a first through hole 130, an explosion-proof hole 140, and a first injection hole 150. The first through hole 130 penetrates the end cap 100 along its thickness direction and is spaced apart from the first protrusion 110. There are two first through holes 130. Along the length direction of the end cap 100, the two first through holes 130 are located on both sides of the first protrusion 110 to allow the electrode post 500 to pass through. One first through hole 130 is for the positive electrode post to pass through, and the other first through hole 130 is for the negative electrode post to pass through.

[0043] Both the explosion-proof hole 140 and the first injection hole 150 are located on the first protrusion 110 and penetrate the first protrusion 110 along the thickness direction of the end cap 100. Specifically, along the length direction of the first protrusion 110, the explosion-proof hole 140 is located in the middle of the first protrusion 110, and there are N second protrusions 120 on each side of the explosion-proof hole 140, with the second protrusions 120 and the first side 112 spaced apart. Along the length direction of the end cap 100, the distance between the explosion-proof hole 140 and the second protrusions 120 is greater than or equal to 10 mm and less than or equal to 30 mm. This not only prevents excessive deformation in the area where the explosion-proof valve 200 is located under pressure, but also takes into account the manufacturability of the end cap 100. The second protrusions 120 and the explosion-proof valve 200 cannot be too close to avoid difficulties in setting the second protrusions 120 on the end cap 100, and prevents deformation of the area around the explosion-proof hole 140 when setting the second protrusions 120. In this embodiment, the distance between the second protrusion 120 and the explosion-proof hole 140 is set within the aforementioned range. This ensures that the effect of preventing deformation of the explosion-proof valve 200 is not weakened due to an excessively large distance, and also ensures that the second protrusion 120 is not difficult to manufacture on the top cover due to an excessively small distance, resulting in better reliability. Specifically, the N second protrusions 120 located on one side of the explosion-proof hole 140 are mirror-symmetrical with respect to the explosion-proof hole 140 to ensure that the end cap 100 has symmetrical strength on opposite sides of the explosion-proof hole 140. The first injection hole 150 is located on the side of one of the second protrusions 120 facing away from the explosion-proof hole 140 and is spaced apart from the second protrusions 120.

[0044] Please refer to Figure 4. The explosion-proof valve 200 is located on the side of a second protrusion 120 away from the first injection port 150, and covers the opening of the explosion-proof port 140 on the first upper surface 111. The explosion-proof valve 200 is positioned between two second protrusions 120, and is spaced apart from both protrusions 120. The protective plate 300 covers the opening of the explosion-proof port 140 on the first lower surface 113 and protects the explosion-proof valve 200.

[0045] In this embodiment, by symmetrically providing second protrusions 120 on both sides of the explosion-proof valve 200, the strength of the end cap 100 located on both sides of the explosion-proof valve 200 is symmetrical, ensuring that the exhaust channels on both sides of the explosion-proof valve 200 are close, and maintaining the gas pressure balance inside the energy storage device 1000 on both sides of the explosion-proof valve 200. This facilitates the timely opening of the explosion-proof valve 200 in the event of thermal runaway, thus improving the safety performance and reliability of the energy storage device 1000. Simultaneously, providing the second protrusion 120 between the explosion-proof valve 200 and the first injection hole 150 can prevent the end cap 100 from deforming due to negative pressure during injection, thereby preventing the explosion-proof valve 200 from being pulled and improving its reliability.

[0046] Please refer to Figures 9 to 11. Figure 9 is a structural schematic diagram of the lower insulating member 400 in the end cap assembly 3000 described in Figure 3. Figure 10 is a structural schematic diagram of the lower insulating member 400 shown in Figure 9 from another angle. Figure 11 is a structural schematic diagram of the lower insulating member 400 shown in Figure 9 after being cut open along CC.

[0047] The lower insulating member 400 is located on the side of the end cap 100 near the second surface 102. The lower insulating member 400 includes a third surface 401, a fourth surface 402, and a second peripheral side surface 403. The third surface 401 is the surface of the lower insulating member 400 near the second surface 102, and the fourth surface 402 is disposed opposite to the third surface 401. The second peripheral side surface 403 connects the third surface 401 and the fourth surface 402.

[0048] The lower insulating member 400 is provided with a third protrusion 410 and a boss 420. The third protrusion 410 is located in the middle of the lower insulating member 400 and is spaced apart from the second peripheral side 403. The third protrusion 410 is provided on the third surface 401 and protrudes in a direction away from the fourth surface 402. The third protrusion 410 is correspondingly arranged with the first protrusion 110, which optimizes the internal structural layout of the energy storage device 1000, makes full use of the space of the energy storage device 1000, and can also support the end cover 100 to a certain extent, further increasing the strength of the end cover assembly 3000. It should be noted that the corresponding arrangement of the third protrusion 410 with the first protrusion 110 means that the orthographic projection of the third protrusion 410 on the end cover 100 will at least partially cover the first protrusion 110. The third protrusion 410 includes a third upper surface 411, a third side surface 412, and a third lower surface 413. The third upper surface 411 has the same orientation as the third surface and is spaced apart from the third surface 401. The third side surface 412 surrounds the third convex hull 410 and connects the third upper surface 411 and the third surface 401. The third lower surface 413 is disposed opposite to the third upper surface 411.

[0049] The boss 420 is located in the middle of the lower insulating member 400 and is spaced apart from the second peripheral side 403. The boss 420 is provided on the fourth surface 402 and protrudes in a direction away from the third surface 401. Specifically, the boss 420 is provided on the third lower surface 413 and protrudes in a direction away from the third upper surface 411, and can abut against the battery cell assembly to limit the positioning of the battery cell assembly. The boss 420 is elongated, and the length direction of the boss 420 is parallel to the width direction of the lower insulating member 400.

[0050] By setting the boss 420 to limit the battery cell assembly, the battery cell assembly can be fixed, avoiding the situation where the electrode tabs are torn or the core becomes loose due to the shaking of the battery cell assembly, and reducing the impact of the battery cell assembly moving along the thickness direction of the lower insulation 400 inside the energy storage device 1000.

[0051] The lower insulating member 400 is further provided with a second groove 430, a first groove 440, a first vent 450, a second vent 460, a third vent 470, a second through hole 480, and a second liquid injection hole 490. The second groove 430 and the first groove 440 are both located in the middle of the lower insulating member 400 and are disposed on the third protrusion 410. The openings of the second groove 430 and the first groove 440 are both located on the third upper surface 411. Both the second groove 430 and the first groove 440 are recessed from the third upper surface 411 towards the third lower surface 413. Specifically, the second groove 430 is located in the middle of the third protrusion 410 and is spaced apart from the second peripheral side 403 and the third side 412. The second groove 430 is correspondingly disposed with the explosion-proof valve 200 and the boss 420. It should be noted that the corresponding arrangement of the second groove 430 with the explosion-proof valve 200 and the boss 420 means that the orthographic projection of the second groove 430 on the end cap 100 will at least partially cover the explosion-proof valve 200, and the orthographic projection of the second groove 430 on the lower insulating member 400 will at least partially cover the boss 420. The second groove 430 includes a bottom wall surface 431 and a side wall surface 432. The bottom wall surface 431 is positioned opposite to the opening of the second groove 430. The bottom wall surface 431 is spaced apart from and opposite to the explosion-proof valve 200. The design of the second groove 430 can increase the gap between the lower insulating member 400 and the explosion-proof valve 200. After passing through the lower insulating member 400, the airflow inside the energy storage device 1000 can flow from the gap between the bottom wall surface 431 and the explosion-proof valve 200 to the explosion-proof valve 200, enabling the explosion-proof valve 200 to open in a timely manner, thereby improving the safety performance and reliability of the energy storage device 1000. The side wall 432 of the groove surrounds the second groove 430 and connects the bottom wall 431 of the groove with the third upper surface 411.

[0052] The first groove 440 is located on one side of the second groove 430 and is spaced apart from the second peripheral side 403 and the second groove 430. The first groove 440 is correspondingly arranged with the second protrusion 120. It should be noted that the correspondence between the first groove 440 and the second protrusion 120 means that the orthographic projection of the first groove 440 on the end cap 100 will at least partially cover the second protrusion 120. There are 2N first grooves 440, which are spaced apart along the length of the lower insulating member 400, where N is a positive integer. The 2N first grooves 440 are mirror-symmetrical about the second groove 430, and each first groove 440 corresponds to one second protrusion 120. It should be noted that the correspondence between the first groove 440 and the second protrusion 120 means that the orthographic projection of the first groove 440 on the end cap 100 will at least partially cover the second protrusion 120. For example, the first groove 440 is square.

[0053] The first vent 450, the second vent 460, the third vent 470, the second through hole 480, and the second injection hole 490 all penetrate the lower insulating member 400 along its thickness direction. The first vent 450 is located on the boss 420. The first vent 450 penetrates the boss 420 along the thickness direction of the lower insulating member 400. There are multiple first vent holes 450, spaced apart from each other. Specifically, the multiple first vent holes 450 are spaced apart along the length direction of the boss 420.

[0054] Both the second vent 460 and the third vent 470 are located on one side of the boss 420 and are disposed on the third protrusion 410, penetrating the third protrusion 410 along the thickness direction of the lower insulating member 400. The second vent 460 is disposed on the bottom wall of the second groove 430 and penetrates the bottom wall of the second groove 430. There are multiple second vents 460, spaced apart from each other. Along the length direction of the lower insulating member 400, a portion of the second vents 460 are located on one side of the boss 420, and another portion are located on the other side of the boss 420. For example, the second vent 460 is elongated, and its length direction is parallel to the width direction of the lower insulating member 400. The third vent 470 is located on the side of the second vent 460 away from the boss 420. There are multiple third vents 470, spaced apart from each other. Along the length of the lower insulating member 400, a portion of the third vent hole 470 is located on one side of the second groove 430, and another portion of the third vent hole 470 is located on the other side of the second groove 430. A portion of the third vent hole 470 may be located on the bottom wall of the first groove 440 and penetrates the bottom wall of the first groove 440.

[0055] Please refer to Figure 12, which is a schematic cross-sectional view of the end cap assembly 3000 shown in Figure 2 cut along point AA. The arrows represent the flow direction of the gas inside the energy storage device 1000.

[0056] In this embodiment, by providing a first vent 450, a second vent 460, and a third vent 470, the airflow generated inside the energy storage device 1000 is ensured to flow rapidly to the explosion-proof valve 200, allowing the explosion-proof valve 200 to open in a timely manner. Specifically, during thermal runaway of the energy storage device 1000, the end cap 100 undergoes slight deformation, creating a gap between the lower insulating component 400 and the end cap. The high-temperature, high-pressure airflow generated on both sides inside the energy storage device 1000 first reaches the top of the battery cell assembly through the channel between the pin 600 and the battery cell assembly, and then rapidly enters the area below the explosion-proof valve 200 through the three-dimensional air passage constructed by the first vent 450, the second vent 460, and the third vent 470. The explosion-proof valve 200 then promptly releases pressure, ensuring the venting performance and reliability of the energy storage device 1000.

[0057] Please refer to Figures 9 to 11. The second through hole 480 is located on one side of the boss 420. Along the length of the lower insulating member 400, the second through hole 480 is located on one side of the third protrusion 410, spaced apart from the third protrusion 410, and communicates with the first through hole 130. There are two second through holes 480, located on opposite sides of the third protrusion 410. One second through hole 480 communicates with one first through hole 130 for the positive terminal to pass through. The other second through hole 480 communicates with the other first through hole 130 for the negative terminal to pass through.

[0058] The second injection hole 490 is located on the third convex 410, and on the side of a first groove 440 opposite to the second groove 430, and is spaced apart from the first groove 440. The second injection hole 490 penetrates the third convex 410 along its thickness direction and communicates with the first injection hole 150. During the injection process of the energy storage device 1000, external electrolyte can flow into the interior of the energy storage device 1000 sequentially from the first injection hole 150 and the second injection hole 490.

[0059] Referring to Figure 4, along the thickness direction of the end cap assembly 3000, each pole post 500 passes through a first through hole 130 and a second through hole 480. Each pin 600 is located on the side of the fourth surface 402 away from the end cap 100, and is fitted onto and fixedly connected to a pole post 500. Each upper insulating member 700 is arranged around a pole post 500 and passes through a first through hole 130 and a second through hole 480. Each sealing ring 800 is fitted onto an upper insulating member 700, passes through a second through hole 480, and is clamped between the second surface 102 of the end cap 100 and the surface of a pin 600 near the lower insulating member 400. This not only seals the gap between the upper insulating member 700 and the lower insulating member 400, ensuring good airtightness of the end cap assembly 3000, but also insulates the end cap 100 from the pin 600.

[0060] The energy storage device 1000 provided in this embodiment increases the strength of the end cover 100 by providing a first protrusion 110 and a second protrusion 120 on the end cover 100. Furthermore, the rectangular shape and dimensions of the second protrusion 120 ensure good resistance to deformation, and the distance between the second protrusion 120 and the explosion-proof hole 140 further prevents excessive deformation of the explosion-proof valve 200 area under pressure, all of which further increase the strength of the end cover 100. Moreover, the N second protrusions 120 located on one side of the explosion-proof hole 140 and the N second protrusions located on the other side of the explosion-proof hole 140 are mirror-symmetrical about the explosion-proof hole 140, making the strength of the end cover 100 symmetrical and uniform on both sides of the explosion-proof valve 200. This ensures that the exhaust channels on both sides of the explosion-proof valve 200 are close, which is beneficial for the timely opening of the explosion-proof valve 200 in the event of thermal runaway of the energy storage device 1000, improving the safety performance and reliability of the energy storage device 1000.

[0061] This embodiment also provides an electrical device, such as an energy storage cabinet or a new energy vehicle. This electrical device includes the energy storage device 1000 described in the above embodiment. Since the specific structure and technical effects of the energy storage device 1000 have already been described in detail above, they will not be repeated here. The electrical device provided in this embodiment improves the exhaust performance and reliability of the electrical device by incorporating the aforementioned energy storage device 1000.

[0062] The above descriptions are merely optional embodiments of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of this application and are not intended to limit the patent scope of this application. At the same time, for those skilled in the art, equivalent structural transformations made based on the inventive concept of this application using the specification and drawings of this application, or direct / indirect applications in other related technical fields, are all included within the patent protection scope of this application.

Claims

1. An end cap, wherein, It includes a first surface, a second surface, and a first peripheral side surface. Along the thickness direction of the end cap, the first surface and the second surface are disposed opposite to each other, and the first peripheral side surface is connected between the first surface and the second surface. The end cap is provided with a first convex bud and a second convex bud. The first convex bud is provided on the first surface and protrudes in a direction away from the second surface, and is spaced apart from the first peripheral side surface. The first convex bud includes a first upper surface, a first side surface and a first lower surface. The first upper surface and the first surface face the same direction. The first side surface connects the first upper surface and the first surface. The first lower surface is disposed opposite to the first upper surface. The second convex bud is provided on the first lower surface and protrudes in a direction away from the first upper surface, and is spaced apart from the first side surface. There are 2N second convex buds, which are spaced apart along the length direction of the end cap, where N is a positive integer. The maximum dimension of each second convex bud along the length direction of the end cap is L1, and the maximum dimension of each second convex bud along the width direction of the end cap is L2, where 1.0≤L2 / L1≤3.

0. The end cap is also provided with an explosion-proof hole. The explosion-proof hole penetrates the first protrusion along the thickness direction of the end cap. Along the length direction of the end cap, there are N second protrusions on opposite sides of the explosion-proof hole, and they are spaced apart from each other.

2. The end cap according to claim 1, wherein, The N second protrusions located on one side of the explosion-proof hole are mirror-symmetrical with respect to the explosion-proof hole as are the N second protrusions located on the other side of the explosion-proof hole.

3. The end cap according to claim 1 or 2, wherein, The ratio of the length of the end cap to the width of the end cap is greater than 4.

4. The end cap according to claim 1 or 2, wherein, The width of the end cap is W, where 0.3W ≤ L2 ≤ 0.6W.

5. The end cap according to claim 1 or 2, wherein, The second convex hull is rectangular.

6. The end cap according to claim 1 or 2, wherein, Along the length of the end cap, the distance between the explosion-proof hole and the second protrusion is greater than or equal to 10 mm and less than or equal to 30 mm.

7. The end cap according to claim 1 or 2, wherein, The second convex hull includes a second upper surface, a second lower surface, and a second side surface. The second upper surface faces the same direction as the first upper surface and is spaced apart from the first upper surface. The second upper surface is flush with the first surface. The second lower surface is spaced apart from the second upper surface and is opposite to it. The second lower surface is flush with the second surface. The second side surface connects the second lower surface and the first lower surface.

8. The end cap according to claim 7, wherein, The distance between the second upper surface and the second lower surface is equal to the distance between the first surface and the second surface, and / or the distance between the first upper surface and the first lower surface is equal to the distance between the first surface and the second surface.

9. The end cap according to claim 1, wherein, The first convex bulge is formed by stamping, and / or the second convex bulge is formed by stamping.

10. An end cap assembly, wherein, Includes an end cap and an explosion-proof valve as described in any one of claims 1 to 9, wherein the explosion-proof valve is installed on the end cap and covers the explosion-proof hole.

11. The end cap assembly of claim 10, wherein, The end cap assembly further includes a lower insulating member located on the side of the end cap closer to the second surface; The lower insulating member includes a third surface, a fourth surface, and a second peripheral side surface. The third surface is the surface of the lower insulating member close to the second surface. The fourth surface is disposed opposite to the third surface. The second peripheral side surface is connected between the third surface and the fourth surface. The lower insulating member is provided with a third protrusion, which is disposed on the third surface and protrudes in a direction away from the fourth surface, and is spaced apart from the second peripheral side surface. The third protrusion is correspondingly disposed with the first protrusion. The third protrusion includes a third upper surface, a third side surface and a third lower surface. The third upper surface has the same orientation as the third surface and is spaced apart from the third surface. The third side surface connects the third upper surface and the third surface. The lower insulating member is further provided with a first groove, which is provided on the third protrusion and spaced apart from the third side surface. The opening of the first groove is located on the third upper surface. The first groove is recessed from the third upper surface to the third lower surface. There are 2N first grooves, and each first groove is provided corresponding to one second protrusion.

12. The end cap assembly according to claim 11, wherein, The end cap assembly further includes a lower insulating member located on the side of the end cap closer to the second surface; The lower insulating member includes a third surface and a fourth surface. The third surface is the surface of the lower insulating member close to the second surface. The fourth surface is disposed opposite to the third surface. The second peripheral side is connected between the third surface and the fourth surface. The lower insulating member is further provided with a boss, which is provided on the fourth surface and protrudes in a direction away from the third surface, and is used to abut against the battery cell assembly, wherein the boss is provided in correspondence with the explosion-proof valve.

13. The end cap assembly according to claim 12, wherein, The lower insulating member is further provided with a first vent hole, which is located on the boss and penetrates the boss along the thickness direction of the lower insulating member.

14. The end cap assembly according to claim 12 or 13, wherein, The lower insulating member is also provided with a second vent hole, which is located on one side of the boss and penetrates the lower insulating member along the thickness direction, and is spaced apart from the boss.

15. The end cap assembly according to claim 14, wherein, The lower insulating member is further provided with a second groove, which is located in the middle of the lower insulating member and is spaced apart from the second peripheral side. The opening of the second groove is located on the third surface. The second groove is corresponding to the explosion-proof valve and the boss. The second vent hole is provided on the bottom wall of the second groove.

16. The end cap assembly according to claim 15, wherein, The lower insulating member is also provided with a third vent hole, which is located on the side of the second vent hole away from the boss, and penetrates the lower insulating member along the thickness direction of the lower insulating member, and is spaced apart from the second groove.

17. The end cap assembly of claim 10, wherein, The end cap is also provided with a first injection hole, which is located on the side of the second protrusion away from the explosion-proof valve, and penetrates the end cap along the thickness direction of the end cap, and is spaced apart from the second protrusion.

18. An energy storage device, wherein, The energy storage device includes a housing, a cell assembly, and an end cap assembly as described in any one of claims 8 to 15. The housing has a receiving cavity and an opening. The receiving cavity is located inside the housing and contains an electrolyte. The opening is located on the top side of the receiving cavity and communicates with the receiving cavity. The cell assembly is housed in the receiving cavity. The end cap assembly is mounted on the housing, closes the opening, and is electrically connected to the cell assembly.

19. An electrical appliance, wherein, The device includes the energy storage device of claim 18, which is used to supply power to the electrical equipment.

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