Top cover assembly, energy storage device and energy storage system

Abstract

The invention discloses a top cover assembly, an energy storage device and an energy storage system.The top cover assembly comprises a cover plate, an installation part, upper plastic and a sealing part, the cover plate is provided with a first side and a second side which are opposite in the first direction, a through hole penetrating to the second side in the first direction is formed in the first side of the cover plate, the installation part is arranged in the through hole, and the upper plastic is arranged in the through hole; a mounting hole penetrating in the first direction is formed in the mounting piece, the mounting hole is configured to be welded to a pole of the energy storage device so as to fix the pole in the mounting hole, the upper plastic is connected to the periphery of the mounting piece, located in the through hole and arranged close to the first side, a fixing part is arranged on the upper plastic, and the fixing part is connected to the mounting piece; the sealing piece is at least partially connected between the installation piece and the inner wall face of the through hole, and the sealing piece is arranged close to the second side. By adopting the scheme of the invention, the mounting hole of the mounting piece can be used for mounting the pole, and a riveting process of the pole is not needed, so that the size design of the pole is relatively flexible.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a top cover assembly, an energy storage device and an energy storage system. Background Art

[0002] In order to avoid short circuit of the battery cell itself, at least one of the positive and negative poles of the battery cell is insulated from the shell of the battery cell. Therefore, the battery cell usually includes a shell and a top cover assembly. The top cover assembly includes a cover plate, an insulating member, a sealing member and a pole. The pole is arranged in the through hole of the cover plate, and the insulating member and the sealing member are arranged between the pole and the cover plate. In the related art, the insulating member and the sealing member are fixed to the cover plate and the sealing member is compressed by adopting the riveting process of the pole (pressing the pole up and down so that the pole expands or deforms outward). However, the riveting process of the pole is adopted. When the size of the pole is large, it will cause excessive force during the riveting process, which is easy to damage other structures of the top cover assembly, and it is easy to cause the seal to shift or uneven force, affecting the sealing effect of the seal on the top cover assembly, and then causing the battery cell to short circuit. Therefore, the size of the pole is limited, which affects the conductive efficiency of the pole. Summary of the invention

[0003] The embodiments of the present invention disclose a top cover assembly, an energy storage device and an energy storage system. The mounting holes of the mounting parts can be used to install the poles, and there is no need to adopt the riveting process of the poles, so that the size design of the poles is more flexible.

[0004] In order to achieve the above-mentioned object, in a first aspect, an embodiment of the present invention discloses a top cover assembly, which is applied to an energy storage device, and the top cover assembly includes:

[0005] A cover plate, the cover plate having a first side and a second side opposite to each other along a first direction, the first side being provided with a through hole penetrating along the first direction to the second side;

[0006] A mounting member, the mounting member is arranged in the through hole, the mounting member is provided with a mounting hole penetrating along the first direction, and the mounting member is configured to be welded to the pole of the energy storage device to fix the pole in the mounting hole;

[0007] an upper plastic, the upper plastic being connected to the outer periphery of the mounting member, the upper plastic being located in the through hole and disposed close to the first side, the upper plastic being provided with a fixing portion, the fixing portion being connected to the mounting member to fix the mounting member along the first direction; and

[0008] A sealing member is at least partially connected between the mounting member and the inner wall surface of the through hole, and the sealing member is arranged close to the second side.

[0009] The top cover assembly of the first aspect of the embodiment of the present invention is adopted, and the cover plate of the top cover assembly can carry the mounting member, the upper plastic and the sealing member. When the top cover assembly is applied to the energy storage device, the cover plate can cover the shell of the energy storage device, the upper plastic is arranged in the through hole of the cover plate, and is used to isolate the mounting member and the cover plate, and the sealing member is arranged in the through hole of the cover plate, and is used to seal the mounting member and the cover plate. When the top cover assembly is applied to the energy storage device, the sealing member can prevent the electrolyte in the energy storage device from flowing to the outside through the gap between the mounting member and the cover plate. The upper plastic is arranged between the cover plate and the mounting member, and the upper plastic can limit the position of the mounting member relative to the cover plate in the radial direction of the through hole. At the same time, the fixing portion arranged on the upper plastic can play a fixing role on the mounting member in the first direction, and can limit the position of the mounting member relative to the cover plate in the first direction, so that the mounting member is fixed relative to the cover plate in the radial direction of the through hole and in the first direction (i.e., the axial direction of the through hole). The mounting hole of the mounting part can be used to pass through the pole, so that the pole can be welded to the mounting part, and the mounting part can fix the seal to the cover plate and compress the seal to improve the sealing effect of the seal. Therefore, such a top cover assembly does not need to be assembled with the pole during the assembly process. After the top cover assembly is assembled, the pole and the mounting part can be welded when the energy storage device is assembled, and there is no need to use the riveting process of the pole, so that the size design of the pole is more flexible, and the conductive efficiency of the pole will not be affected by the size limit of the pole.

[0010] As an optional implementation, in an embodiment of the first aspect of the present invention, the upper plastic is configured to be formed by injection molding between the inner wall surface of the through hole and the outer periphery of the mounting member.

[0011] By adopting the solution of this embodiment, on the one hand, the connection between the upper plastic and the mounting parts and the cover plate can be made tighter through the injection molding process, which can better play the role of fixing the mounting parts and the cover plate. There is no need to set up other additional structures to fix the upper plastic, the mounting parts and the cover plate, thereby simplifying the structure of the top cover assembly. On the other hand, the injection molding process is relatively simple, which can reduce the difficulty of processing the upper plastic.

[0012] As an optional implementation, in an embodiment of the first aspect of the present invention, the mounting member is provided with a first snap-fitting portion, the upper plastic is provided with a second snap-fitting portion, the first snap-fitting portion is snap-fittedly connected to the second snap-fitting portion, one of the first snap-fitting portion and the second snap-fitting portion is a protrusion, and the other is a recessed portion.

[0013] By adopting the solution of this embodiment, by providing the first engaging portion and the second engaging portion, the upper plastic can be fixed to the mounting member in the axial direction of the mounting hole, so that the upper plastic and the mounting member are fixed in both the axial direction and the radial direction of the mounting hole, and the upper plastic and the mounting member are better fixed. In addition, since the upper plastic is formed by injection molding, after the first engaging portion is provided on the mounting member, the second engaging portion of the upper plastic can be directly formed by injection molding, which does not increase the processing difficulty of the upper plastic. At the same time, the first engaging portion and the second engaging portion can be closely matched, and the first engaging portion and the second engaging portion will not be unable to be engaged and connected due to processing errors and other reasons.

[0014] As an optional implementation, in an embodiment of the first aspect of the present invention, a third clamping portion is provided on the inner wall surface of the through hole, and a fourth clamping portion is provided on the upper plastic, the first clamping portion is clamped and connected to the second clamping portion, and one of the third clamping portion and the fourth clamping portion is a protrusion, and the other is a recessed portion.

[0015] By adopting the solution of this embodiment, by providing the third clamping part and the fourth clamping part, the upper plastic can be fixed to the cover plate in the axial direction of the mounting hole, so that the upper plastic and the cover plate are fixed in the axial and radial directions of the mounting hole, and the upper plastic and the cover plate are better fixed.

[0016] As an optional implementation, in an embodiment of the first aspect of the present invention, in the first direction, the mounting piece protrudes from the upper plastic, and the length of the portion of the mounting piece protruding from the upper plastic is d, and the distance d satisfies: d≤0.5mm, and / or, d≥0.3mm.

[0017] By adopting the solution of this embodiment, on the one hand, the length of the portion of the mounting member protruding from the upper plastic will not be too long, that is, the overall length of the mounting member will not be too long, thereby reducing the overall length of the top cover assembly, which is beneficial to the miniaturization of the energy storage device. On the other hand, the upper surface of the mounting member is kept at a certain distance from the upper surface of the upper plastic, which can avoid the upper plastic melting and failure caused by the welding head being too close to the upper surface of the upper plastic when welding the mounting member and the pole. At the same time, after the pole is installed in the mounting hole, the upper surface of the pole is usually flush with or slightly protruding from the upper surface of the mounting member, so that the upper surface of the mounting member is kept at a certain distance from the upper surface of the upper plastic, which can be beneficial to achieve a more reliable electrical connection between the pole and other components.

[0018] As an optional implementation, in an embodiment of the first aspect of the present invention, the mounting member includes a first main body portion and a first step portion connected to each other, the first main body portion is provided with the mounting hole, the first main body portion is arranged in the through hole, the upper plastic is connected to the outer periphery of the first main body portion, the first step portion is connected to an end of the first main body portion close to the second side, and the first step portion is at least partially arranged corresponding to the second side;

[0019] The seal includes a second main body portion and a second step portion which are connected to each other, the second main body portion is connected between the outer periphery of the first main body portion and the inner wall surface of the through hole, the second step portion is connected to an end of the second main body portion close to the second side, and the second step portion is at least partially located between the first step portion and the second side.

[0020] By adopting the solution of this embodiment, the first main body can fix the plastic and the seal along the radial direction of the mounting hole, and the first step portion can bear the seal and fix the seal along the axial direction of the mounting hole, so that the seal is better compressed and fixed, and the sealing effect of the seal is improved. The first main body can fix the second main body along the radial direction of the mounting hole, and the first step portion can bear the second step portion and fix the second step portion along the axial direction of the mounting hole, so that the seal is better fixed, and the sealing effect of the seal is improved. In addition, the second main body and the second step portion of the seal extend in two directions (axial and radial directions of the mounting hole), which can increase the contact area between the seal and the mounting member and the cover plate, and further improve the sealing effect of the seal.

[0021] In a second aspect, an embodiment of the present invention discloses an energy storage device, which includes a shell, a battery cell, a current collector, a pole and a top cover assembly as described in the first aspect of the above embodiment, wherein the shell is provided with a accommodating cavity, the accommodating cavity has a first opening, the battery cell and the current collector are arranged in the accommodating cavity, the current collector is connected to the battery cell, the cover plate is connected to the shell to close the first opening, and the pole is arranged in the mounting hole and connected to the current collector.

[0022] The energy storage device of the second aspect of the present embodiment is adopted. Since the energy storage device adopts the top cover assembly of the first aspect of the embodiment of the present invention, the upper plastic is arranged between the cover plate and the mounting member. The upper plastic can limit the position of the mounting member relative to the cover plate in the radial direction of the through hole. At the same time, the fixing portion arranged on the upper plastic can play a fixing role on the mounting member in the first direction, and can limit the position of the mounting member relative to the cover plate in the first direction, so that the mounting member is fixed relative to the cover plate in the radial direction of the through hole and in the first direction (i.e., the axial direction of the through hole). The mounting hole of the mounting member can be used to pass through the pole, so that the pole can be welded with the mounting member, and the mounting member can fix the seal to the cover plate and compress the seal to improve the sealing effect of the seal. Therefore, in the process of assembling the energy storage device of the present invention, the top cover assembly and the pole can be assembled separately. After the top cover assembly is assembled, the pole and the mounting member can be welded when assembling the energy storage device, without the need to adopt the riveting process of the pole, so that the size design of the pole is more flexible, and the conductive efficiency of the pole will not be affected by the size limitation of the pole. In addition, since the top cover assembly and the pole are detachably arranged, when assembling the energy storage device, the pole and the current collector of the energy storage device can be welded first, and then the top cover assembly can be covered on the shell of the energy storage device. The pole can pass through the mounting hole, and then the pole and the mounting piece can be welded. The assembly process is relatively simple, and it is easy to control the assembly tolerance of the top cover assembly and the shell. There is no need to use a foldable current collector, which can reduce the resistance of the current collector itself, that is, it can reduce the internal resistance of the energy storage device, thereby reducing power loss and improving the output efficiency of the energy storage device.

[0023] As an optional embodiment, in an embodiment of the second aspect of the present invention, the current collector has a second surface and a third surface along its own thickness direction, the pole is welded to the second surface, the battery cell is welded to the third surface, and the current collector is constructed as a single-layer sheet structure at least in the portion corresponding to the pole.

[0024] By adopting the solution of this embodiment, by making the current collector have a second surface and a third surface along its own thickness direction, it is possible to facilitate welding of the current collector with the pole and the battery cell, and it is possible to simplify the structure of the current collector and reduce the production cost of the energy storage device. At the same time, it is possible to reduce the resistance of the current collector itself, that is, it is possible to reduce the internal resistance of the energy storage device, thereby reducing power loss and improving the output efficiency of the energy storage device.

[0025] In a third aspect, an embodiment of the present invention discloses an energy storage system, which includes the energy storage device as described in the second aspect of the above embodiment.

[0026] The energy storage system of the third aspect of the present embodiment is adopted. Since the energy storage system adopts the energy storage device of the second aspect of the embodiment of the present invention, the upper plastic is arranged between the cover plate and the mounting member, and the upper plastic can limit the position of the mounting member relative to the cover plate in the radial direction of the through hole. At the same time, the fixing portion arranged on the upper plastic can play a fixing role on the mounting member in the first direction, and can limit the position of the mounting member relative to the cover plate in the first direction, so that the mounting member is fixed relative to the cover plate in the radial direction of the through hole and in the first direction (i.e., the axial direction of the through hole). The mounting hole of the mounting member can be used to pass through the pole, so that the pole can be welded with the mounting member, and the mounting member can fix the seal to the cover plate and compress the seal to improve the sealing effect of the seal. Therefore, in the process of assembling the energy storage device of the present invention, the top cover assembly and the pole can be assembled separately. After the top cover assembly is assembled, the pole and the mounting member can be welded when assembling the energy storage device, without the need to adopt the riveting process of the pole, so that the size design of the pole is more flexible, and the conductive efficiency of the pole will not be affected by the size limitation of the pole. In addition, since the top cover assembly and the pole are detachably arranged, when assembling the energy storage device, the pole and the current collector of the energy storage device can be welded first, and then the top cover assembly can be covered on the shell of the energy storage device. The pole can pass through the mounting hole, and then the pole and the mounting piece can be welded. The assembly process is relatively simple, and it is easy to control the assembly tolerance of the top cover assembly and the shell. There is no need to use a foldable current collector, which can reduce the resistance of the current collector itself, that is, it can reduce the internal resistance of the energy storage device, thereby reducing power loss and improving the output efficiency of the energy storage device.

[0027] In a fourth aspect, an embodiment of the present invention discloses a method for assembling a top cover assembly, wherein the top cover assembly includes the top cover assembly as described in the first aspect of the above embodiment, and the assembly method includes the following steps:

[0028] Installing the sealing member and the mounting member in the through hole, and making the sealing member located at the outer periphery of the mounting member;

[0029] The upper plastic is arranged in the through hole so that the upper plastic is connected between the outer periphery of the mounting member and the inner wall surface of the through hole.

[0030] By adopting the assembly method of the top cover assembly of the fourth aspect of this embodiment, the top cover assembly does not need to be assembled together with the pole during the assembly process, and there is no need to adopt the riveting process of the pole. The assembly process is relatively simple and the size design of the pole is relatively flexible.

[0031] As an optional implementation, in an embodiment of the fifth aspect of the present invention, the step of installing the sealing member and the mounting member in the through hole and making the sealing member located at the periphery of the mounting member comprises:

[0032] Mounting the sealing member on the outer periphery of the mounting member to form a first assembly;

[0033] The first component is inserted into the through hole so that the sealing member is sealed and connected between the outer periphery of the mounting member and the inner wall surface of the through hole.

[0034] By adopting the solution of this embodiment, there is no need to use a clamp to fix the sealing member and the mounting member relative to the through hole during the assembly process, which can simplify the assembly process of the top cover assembly.

[0035] As an optional implementation, in an embodiment of the fifth aspect of the present invention, the upper plastic is arranged in the through hole so that the upper plastic is connected between the outer periphery of the mounting member and the inner wall surface of the through hole, comprising:

[0036] The upper plastic is formed by injection molding in the through hole, and the upper plastic is connected to the outer periphery of the mounting member and the inner wall surface of the through hole by injection molding.

[0037] By adopting the solution of this embodiment, the sealing member can be directly sleeved on the outer periphery of the mounting member, and the first step portion can support the sealing member, so that the sealing member and the mounting member form a first component, which can facilitate the installation of the sealing member and the mounting member in the through hole.

[0038] In a fifth aspect, an embodiment of the present invention discloses an assembly method of an energy storage device, wherein the energy storage device includes the energy storage device as described in the second aspect of the above embodiment, and the assembly method includes the assembly method of the top cover assembly as described in the fourth aspect of the above embodiment and the following steps:

[0039] Installing the battery cell in the accommodating cavity of the shell;

[0040] Welding the current collector to the battery cell and the pole;

[0041] The cover plate of the assembled top cover assembly is covered on the shell to close the first opening, and the pole welded with the current collector is passed through the mounting hole.

[0042] By adopting the assembly method of the energy storage device of the fifth aspect of the present embodiment, during the assembly of the energy storage device, the top cover assembly and the pole can be assembled separately, without the need to adopt the riveting process of the pole, so that the size design of the pole is more flexible, and the conductive efficiency of the pole is not affected by the size limitation of the pole. In addition, there is no need to adopt a foldable current collector, the assembly process is relatively simple, and it is easy to control the assembly tolerance of the top cover assembly and the shell, and the resistance of the current collector itself can be reduced, that is, the internal resistance of the energy storage device can be reduced, thereby reducing the power loss and improving the output efficiency of the energy storage device.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The top cover assembly, energy storage device and energy storage system provided by the embodiment of the present invention, the cover plate of the top cover assembly can carry the mounting member, the upper plastic and the sealing member, when the top cover assembly is applied to the energy storage device, the cover plate can cover the shell of the energy storage device, the upper plastic is arranged in the through hole of the cover plate, used to isolate the mounting member and the cover plate, the sealing member is arranged in the through hole of the cover plate, used to seal the mounting member and the cover plate, when the top cover assembly is applied to the energy storage device, the sealing member can prevent the electrolyte in the energy storage device from flowing to the outside through the gap between the mounting member and the cover plate. The upper plastic is arranged between the cover plate and the mounting member, the upper plastic can limit the position of the mounting member relative to the cover plate in the radial direction of the through hole, and at the same time, the fixing portion arranged on the upper plastic can play a fixing role on the mounting member in the first direction, and can limit the position of the mounting member relative to the cover plate in the first direction, so that the mounting member is fixed relative to the cover plate in the radial direction of the through hole and in the first direction (i.e., the axial direction of the through hole). The mounting hole of the mounting part can be used to pass through the pole, so that the pole can be welded to the mounting part, and the mounting part can fix the seal to the cover plate and compress the seal to improve the sealing effect of the seal. Therefore, such a top cover assembly does not need to be assembled with the pole during the assembly process. After the top cover assembly is assembled, the pole and the mounting part can be welded when the energy storage device is assembled, and there is no need to use the riveting process of the pole, so that the size design of the pole is more flexible, and the conductive efficiency of the pole will not be affected by the size limit of the pole. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 is a cross-sectional view of a top cover assembly and a current collector in the related art;

[0047] Figure 2 is a schematic diagram of the three-dimensional structure of the top cover assembly disclosed in the first aspect of the embodiment of the present application;

[0048] Figure 3 yes Figure 2 A cross-sectional view of the top cover assembly in the AA direction;

[0049] Figure 4 yes Figure 2 A cross-sectional view of the top cover assembly (after being assembled with the pole) in the AA direction;

[0050] Figure 5 is a schematic diagram of the three-dimensional structure of the mounting member disclosed in the first aspect of the embodiment of the present application;

[0051] Figure 6 It is a schematic diagram of the three-dimensional structure of the upper plastic disclosed in the first aspect of the embodiment of the present application;

[0052] Figure 7 is a schematic diagram of the three-dimensional structure of the sealing member disclosed in the first aspect of the embodiment of the present application;

[0053] Figure 8 It is a schematic flow chart of an assembly method of a top cover assembly disclosed in the second aspect of an embodiment of the present application;

[0054] Fig. 9 is a schematic diagram of the three-dimensional structure of the energy storage device disclosed in the third aspect of the embodiment of the present application;

[0055] Fig.10 yes Fig. 9 A cross-sectional view of the energy storage device in the BB direction;

[0056] Fig.11 is a schematic flow chart of an assembly method of an energy storage device disclosed in the fourth aspect of an embodiment of the present application;

[0057] Fig.12 is a schematic structural diagram of the energy storage module disclosed in the fifth aspect of the embodiment of the present application;

[0058] Fig.13 It is a schematic diagram of the structure of an energy storage system disclosed in the sixth aspect of the embodiment of the present application.

[0059] Icons of related technologies: 5. Top cover assembly; 50. Cover plate; 51. Insulator; 52. Sealing member; 53. Pole; 6. Current collector; 60. Disc; 61. Bending portion; 62. Mounting portion;

[0060] Icons of the present application: 1. top cover assembly; 10. cover plate; 100. through hole; 100a. first hole body; 100b. second hole body; 101. first side; 1010. first surface; 102. second side; 103. third clamping part; 11. mounting member; 11a. first main body; 11b. first step part; 110. mounting hole; 111. first clamping part; 12. upper plastic; 120. second clamping part; 121. fourth clamping part; 13. sealing member; 13a. second main body; 13b. second step part; 14. lower plastic;

[0061] 2. Energy storage device; 20. Shell; 21. Cell; 22. Current collector; 220. Second surface; 221. Third surface; 23. Pole;

[0062] 3. Energy storage module; 30. Ba chip;

[0063] 4. Energy storage system; 40. High voltage cable; 41. First electric energy conversion device; 42. Second electric energy conversion device;

[0064] X, first direction. DETAILED DESCRIPTION

[0065] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] For related technologies, see Figure 1 The top cover assembly 5 usually includes a cover plate 50, an insulating member 51, a sealing member 52 and a pole 53, and adopts a riveting process for the pole 53 (pressing the pole 53 up and down so that the pole 53 expands or deforms outward), fixes the insulating member 51 and the sealing member 52 to the cover plate 50, and compresses the sealing member 52, that is, the pole 53 is a part of the top cover assembly 5, and is assembled integrally with the cover plate 50, the insulating member 51, and the sealing member 52. However, the riveting process for the pole 53 may cause excessive force during the riveting process when the size of the pole 53 is large, which may easily damage other structures of the top cover assembly 5, or cause the sealing member 52 to shift, affecting the sealing effect of the sealing member 52 on the top cover assembly 5, and further causing the battery cell using such a top cover assembly 5 to be short-circuited, so the size of the pole 53 is limited, which directly affects the conductive efficiency of the pole 53.

[0067] In addition, when such a top cover assembly 5 is applied to an energy storage device, since the pole 53 is a part of the top cover assembly 5, after the top cover assembly 5 is covered on the shell of the energy storage device, the contact surface between the pole 53 and the current collector 6 of the energy storage device is located inside the energy storage device, and it is difficult to achieve welding of the pole 53 and the current collector 6 (the pole 53 needs to be welded to the current collector 6 to ensure the reliability of the electrical conductivity of the pole 53 and the current collector 6). Therefore, it is necessary to design the current collector 6 as a foldable current collector, that is, the current collector 6 includes a disc 60, a bending portion 61 and a mounting portion 62, the top cover assembly 5 is set with the mounting portion 62, and the pole 53 and the mounting portion 62 are welded, and after the disc 60 and the battery cell of the energy storage device are welded, the connection between the bending portion 61 and the disc 60 and the mounting portion 62 is folded, thereby completing the assembly of the top cover assembly 5 and the shell. However, the current collector 6 needs to be folded twice or more to complete the assembly of the top cover assembly 5 and the shell. Due to the poor control accuracy of the existing production process during folding, there will be a large assembly tolerance between the top cover assembly 5 and the shell. As a result, when the top cover assembly 5 is installed in the shell, the folded current collector 6 is prone to scratches and damage the shell, and may even cause the top cover assembly 5 to be unable to be smoothly installed in the shell. In addition, the foldable current collector 6 is relatively long, which increases the internal resistance of the energy storage device, thereby causing excessive power loss and affecting the output efficiency of the energy storage device.

[0068] Based on this, the present application discloses a top cover assembly, in which a mounting piece is arranged on the top cover assembly, and the mounting hole of the mounting piece can be used to install the pole. At the same time, the mounting piece can fix the upper plastic and the seal to the cover plate, and compress the seal to improve the sealing effect of the seal. Therefore, such a top cover assembly does not need to be assembled together with the pole during the assembly process, and there is no need to adopt the riveting process of the pole, so that the size design of the pole is more flexible.

[0069] The technical solution of the present invention will be further described below in conjunction with embodiments and drawings.

[0070] Top cover assembly 1

[0071] Please also read Figures 2 to 3A first aspect of an embodiment of the present invention discloses a top cover assembly 1, which is applied to an energy storage device. The top cover assembly 1 includes a cover plate 10, a mounting member 11, an upper plastic 12 and a sealing member 13. The cover plate 10 has a first side 101 and a second side 102 opposite to each other along a first direction X. The first side 101 is provided with a through hole 100 penetrating to the second side 102 along the first direction X. The mounting member 11 is arranged in the through hole 100. The mounting member 11 is provided with a mounting hole 110 penetrating itself along the first direction X. The mounting member 11 is configured to be welded to the pole of the energy storage device to fix the pole in the mounting hole 110. The upper plastic 12 is connected to the outer periphery of the mounting member 11. The upper plastic 12 is located in the through hole 100 and is arranged close to the first side 101. A fixing portion is provided on the upper plastic 12, and the fixing portion is connected to the mounting member 11 to fix the mounting member 11 along the first direction X. The sealing member 13 is at least partially connected between the mounting member 11 and the inner wall surface of the through hole 100, and is arranged close to the second side 102.

[0072] It can be understood that the energy storage device may include, for example, a cylindrical battery or a square battery. The energy storage device generally includes two current collectors and two poles, the two current collectors are a positive current collector and a negative current collector, the two poles are a positive pole and a negative pole, the positive pole is connected to the positive current collector, and the negative pole is connected to the negative current collector.

[0073] When the energy storage device is a cylindrical battery, the positive electrode column and the negative electrode column are respectively arranged at both ends of the cylindrical battery, and the top cover assembly disclosed in the present invention can be arranged at both ends or any one end of the cylindrical battery, for example, Fig.10 As shown, a top cover assembly 1 is provided at one end of the energy storage device, and a mounting hole 110 of the top cover assembly 1 is connected to a negative electrode column (which may also be a positive electrode column).

[0074] When the energy storage device is a square battery, the positive electrode column and the negative electrode column are arranged at the same end of the round battery, and one end of the energy storage device is provided with the top cover assembly 1 disclosed in the present invention, the top cover assembly 1 includes a cover plate 10, two mounting members 11, two upper plastics 12 and two sealing members 13, the cover plate 10 is provided with two through holes 100 passing through itself along the first direction X at intervals, the two mounting members 11, the two upper plastics 12 and the two sealing members 13 are respectively arranged in the two through holes 100, and the positive electrode column and the negative electrode column are respectively arranged in the mounting holes 110 of the two mounting members 11.

[0075] The top cover assembly 1 provided in the first aspect of the embodiment of the present invention has a cover plate 10 capable of carrying a mounting member 11, an upper plastic 12 and a sealing member 13. When the top cover assembly 1 is applied to an energy storage device, the cover plate 10 can seal the housing of the energy storage device. The upper plastic 12 is disposed in the through hole 100 of the cover plate 10 to isolate the mounting member 11 from the cover plate 10. The sealing member 13 is disposed in the through hole 100 of the cover plate 10 to seal the mounting member 11 from the cover plate 10. When the top cover assembly 1 is applied to an energy storage device, the sealing member 13 can prevent the electrolyte in the energy storage device from flowing to the outside through the gap between the mounting member 11 and the cover plate 10. The upper plastic 12 is disposed between the cover plate 10 and the mounting member 11. The upper plastic 12 can limit the radial position of the mounting member 11 relative to the cover plate 10 in the through hole 100. At the same time, the fixing portion disposed on the upper plastic 12 can fix the mounting member 11 in the first direction X, and can limit the position of the mounting member 11 relative to the cover plate 10 in the first direction X, so that the mounting member 11 is fixed relative to the cover plate 10 in the radial direction of the through hole 100 and in the first direction X (i.e., the axial direction of the through hole 100). The mounting hole 110 of the mounting member 11 can be used to pass through the pole, so that the pole can be welded to the mounting member 11. The mounting member 11 can fix the seal 13 to the cover plate 10 and compress the seal 13 to improve the sealing effect of the seal 13. Therefore, such a top cover assembly 1 does not need to be assembled together with the pole during the assembly process. After the top cover assembly 1 is assembled, the pole and the mounting member 11 can be welded when the energy storage device is assembled. After the top cover assembly 1 is assembled, the pole and the mounting member 11 can be welded when the energy storage device is assembled. There is no need to adopt the riveting process of the pole, so that the size design of the pole is more flexible, and the conductive efficiency of the pole will not be affected by the size limitation of the pole.

[0076] In addition, when the top cover assembly 1 is applied to the energy storage device, since the top cover assembly 1 and the pole are detachably arranged, when assembling the energy storage device, the pole and the current collector of the energy storage device can be welded first, and then the top cover assembly 1 is covered on the shell of the energy storage device, and the pole can pass through the mounting hole 110, and then the pole and the mounting member 11 can be welded. The assembly process is relatively simple, and it is easy to control the assembly error between the top cover assembly 1 and the shell, and there is no need to use a foldable current collector, which can reduce the resistance of the current collector itself, that is, it can reduce the internal resistance of the energy storage device, thereby reducing power loss and improving the output efficiency of the energy storage device.

[0077] The first side 101 of the cover plate 10 in the present application refers to the side of the cover plate 10 that is away from the interior of the energy storage device when the cover plate 10 is assembled in the shell of the energy storage device, and the second side 102 of the cover plate 10 refers to the side of the cover plate 10 that is located inside the shell or connected to the shell when the cover plate 10 is assembled in the shell of the energy storage device.

[0078] Optionally, the cover plate 10 may be a plain aluminum sheet or a stainless steel plate, etc., which may be selected according to actual conditions and is not specifically limited in this embodiment.

[0079] In some embodiments, the through hole 100 includes a first hole body 100a and a second hole body 100b connected along the first direction X, the first hole body 100a is close to the first side 101, the second hole body 100b is close to the second side 102, the upper plastic 12 is disposed on the first hole body 100a, and the sealing member 13 is disposed on the second hole body 100b.

[0080] In this way, the first hole 100 a can accommodate the upper plastic 12 , and the second hole 100 b can accommodate the sealing member 13 , so as to facilitate the positioning of the upper plastic 12 and the sealing member 13 on the cover plate 10 .

[0081] Optionally, the mounting member 11 may be a hollow columnar structure or a block structure, etc., which may be selected according to actual conditions and is not specifically limited in this embodiment.

[0082] Optionally, the material of the mounting member 11 may be metal for the entire mounting member 11, or the mounting hole 110 of the mounting member 11 may be formed as a metalized hole, and the mounting member 11 itself may be made of metal or non-metal. For example, a metal layer is coated on the inner wall surface of the mounting hole 110 of the mounting member 11, wherein the metal may be copper or silver, etc., which may be selected according to actual conditions and is not specifically limited in this embodiment.

[0083] In some embodiments, in the first direction X, the mounting member 11 protrudes from the upper plastic 12, and the length of the portion of the mounting member 11 protruding from the upper plastic 12 is d, that is, the distance between the upper surface of the mounting member 11 and the upper surface of the upper plastic 12 is d, and the distance d satisfies: d≤0.5mm, and / or, d≥0.3mm.

[0084] In one example, the distance d satisfies: d≤0.5 mm.

[0085] In this way, the length of the portion of the mounting member 11 protruding from the upper plastic 12 will not be too long, that is, the overall length of the mounting member 11 will not be too long, thereby reducing the overall length of the top cover assembly 1 and facilitating the miniaturization of the energy storage device.

[0086] In another example, the distance d satisfies: d≥0.3 mm.

[0087] In this way, the upper surface of the mounting member 11 is kept at a certain distance from the upper surface of the upper plastic 12, which can prevent the upper plastic 12 from melting and failing due to the welding head being too close to the upper surface of the upper plastic 12 when welding the mounting member 11 and the pole. At the same time, after the pole is installed in the mounting hole 110, the upper surface of the pole is usually flush with or slightly protrudes from the upper surface of the mounting member 11, so that the upper surface of the mounting member 11 is kept at a certain distance from the upper surface of the upper plastic 12, which can facilitate a more reliable electrical connection between the pole and other components.

[0088] In another example, the distance d satisfies: 0.3 mm ≤ d ≤ 0.5 mm. For example, the distance d may be 0.3 mm, 0.4 mm, or 0.5 mm.

[0089] In this way, on the one hand, the length of the portion of the mounting member 11 protruding from the upper plastic 12 will not be too long, that is, the overall length of the mounting member 11 will not be too long, thereby reducing the overall length of the top cover assembly 1, which is beneficial to the miniaturization of the energy storage device. On the other hand, the upper surface of the mounting member 11 is kept at a certain distance from the upper surface of the upper plastic 12, which can avoid the upper plastic 12 melting and failure due to the welding head being too close to the upper surface of the upper plastic 12 when welding the mounting member 11 and the pole. At the same time, after the pole is installed in the mounting hole 110, the upper surface of the pole is usually flush with or slightly protruding from the upper surface of the mounting member 11, so that the upper surface of the mounting member 11 is kept at a certain distance from the upper surface of the upper plastic 12, which can be beneficial to achieve a more reliable electrical connection between the pole and other components.

[0090] In some embodiments, the mounting member 11 includes a first main body portion 11a and a first step portion 11b connected to each other, the first main body portion 11a is provided with a mounting hole 110, the first main body portion 11a is disposed in the through hole 100, the upper plastic 12 is connected to the outer periphery of the first main body portion 11a, the first step portion 11b is connected to an end of the first main body portion 11a close to the second side 102, and the first step portion 11b is at least partially disposed corresponding to the second side 102, and the sealing member 13 is connected to the first main body portion 11a and the inner wall surface of the through hole 100, and is disposed on the first step portion 11b.

[0091] In this way, the first main body 11a can fix the plastic 12 and the seal 13 along the radial direction of the mounting hole 110, and the first step portion 11b can support the seal 13 and can better compress the seal 13 between the first step portion 11b and the cover plate 10, thereby improving the sealing effect of the seal 13.

[0092] Optionally, the first main body portion 11a may be a columnar structure or a block structure, etc., and the first step portion 11b may be an annular structure or a plate structure around the axial direction of the mounting hole 110, etc. The specific selection can be made according to actual conditions and is not specifically limited in this embodiment.

[0093] Optionally, the material of the upper plastic 12 may be polyphenylene sulfide or polyphenylene sulfide with glass fiber or conductive carbon added thereto. The material may be selected according to actual conditions and is not specifically limited in this embodiment.

[0094] In some embodiments, the upper plastic 12 is configured to be formed by injection molding between the inner wall surface of the through hole 100 and the outer periphery of the mounting member 11. In this embodiment, the upper plastic 12 is formed by injection molding between the inner wall surface of the first hole 100a and the outer periphery of the first main body 11a.

[0095] In this way, on the one hand, the injection molding process can make the connection between the upper plastic 12 and the mounting member 11 and the cover plate 10 tighter, which can better fix the mounting member 11 and the cover plate 10. There is no need to set up other additional structures to fix the upper plastic 12, the mounting member 11 and the cover plate 10, thereby simplifying the structure of the top cover assembly 1. On the other hand, the injection molding process is relatively simple, which can reduce the difficulty of processing the upper plastic 12.

[0096] It can be seen that the top cover assembly 1 of the present application is formed by injection molding the upper plastic 12 between the inner wall surface of the through hole 100 and the outer periphery of the mounting member 11, so that the fixation between the upper plastic 12 and the cover plate 10 can be achieved by injection molding. At the same time, the upper plastic 12 can also be used to fix the mounting member 11 and the cover plate 10, so that the mounting member 11 does not need to be connected to the cover plate 10 with an additional fixing structure, which simplifies the fixing process between the mounting member 11 and the cover plate 10, and also simplifies the structural design of the top cover assembly 1.

[0097] In some embodiments, the first side 101 has a first surface 1010 , and in the first direction X, the upper plastic 12 is flush with the first surface 1010 .

[0098] In this way, on the one hand, since the upper plastic 12 is formed by injection molding in the first hole body 100a, the upper plastic 12 can have a certain thickness in the first direction X (that is, the depth of the first hole body 100a), so that the upper plastic 12 has sufficient structural strength. On the other hand, the upper plastic 12 will not exceed the first surface 1010 in the first direction X, avoiding the upper plastic 12 occupying too much space and affecting the overall length of the top cover assembly 1 in the first direction X, which is conducive to the miniaturization of the energy storage device.

[0099] In this embodiment, the upper plastic 12 is flush with the first side 101, which means that the upper plastic 12 is roughly flush with the first side 101. Errors caused by processing errors of the upper plastic 12 and assembly tolerances of the upper plastic 12 and the cover plate 10 are all within the scope of protection of this embodiment.

[0100] Optionally, the fixing part can be a separate component, for example, the fixing part can be a clip, through which the upper plastic and the mounting part are fixed. The fixing part can also be a part of the upper plastic 12, for example, the fixing part can be a protrusion or depression on the upper plastic, etc. The specific selection can be made according to actual conditions and is not specifically limited in this embodiment.

[0101] See also Figure 3 In some embodiments, the mounting member 11 is provided with a first snap-fitting portion 111, the fixing portion is configured as a second snap-fitting portion 120, the first snap-fitting portion 111 is snap-fitted to the second snap-fitting portion 120, one of the first snap-fitting portion 111 and the second snap-fitting portion 120 is a protrusion, and the other is a depression.

[0102] In this way, by providing the first engaging portion 111 and the second engaging portion 120, the upper plastic 12 can be fixed to the mounting member 11 in the axial direction of the mounting hole 110, so that the upper plastic 12 and the mounting member 11 are fixed in both the axial direction and the radial direction of the mounting hole 110, and the upper plastic 12 and the mounting member 11 are better fixed. In addition, since the upper plastic 12 is formed by injection molding, after the first engaging portion 111 is provided on the mounting member 11, the second engaging portion 120 of the upper plastic 12 can be directly formed by injection molding, which does not increase the processing difficulty of the upper plastic 12. At the same time, the first engaging portion 111 and the second engaging portion 120 can be closely matched, and the first engaging portion 111 and the second engaging portion 120 will not fail to be engaged and connected due to processing errors and other reasons.

[0103] Optionally, the number of the first engaging portion 111 and the second engaging portion 120 may be one or more, which may be selected according to actual conditions and is not specifically limited in this embodiment.

[0104] In some embodiments, a third engaging portion 103 is provided on the inner wall surface of the through hole 100, a fourth engaging portion 121 is provided on the upper plastic 12, the first engaging portion 111 is engaged with the second engaging portion 120, and one of the third engaging portion 103 and the fourth engaging portion 121 is a protrusion, and the other is a depression.

[0105] In this way, by providing the third engaging portion 103 and the fourth engaging portion 121 , the upper plastic 12 can be fixed to the cover plate 10 in the axial direction of the mounting hole 110 , so that the upper plastic 12 and the cover plate 10 are fixed in both the axial and radial directions of the mounting hole 110 , and the upper plastic 12 and the cover plate 10 are better fixed.

[0106] In addition, since the upper plastic 12 is formed by injection molding, after the third engaging portion 103 is provided on the inner wall surface of the through hole 100, the fourth engaging portion 121 of the upper plastic 12 can be directly formed by injection molding, which does not increase the processing difficulty of the upper plastic 12. At the same time, the third engaging portion 103 and the fourth engaging portion 121 can be closely matched, thereby avoiding or reducing the situation in which the third engaging portion 103 and the fourth engaging portion 121 cannot be engaged and connected due to processing errors and the like.

[0107] Optionally, the number of the third engaging portion 103 and the fourth engaging portion 121 may be one or more, which may be selected according to actual conditions and is not specifically limited in this embodiment.

[0108] Optionally, the above-mentioned protrusion may be a protrusion arranged axially around the mounting hole 110 or a protrusion extending radially along the mounting hole 110. Correspondingly, the above-mentioned recess may be a protrusion arranged axially around the mounting hole 110 or a protrusion extending radially along the mounting hole 110. The specific selection can be made according to actual conditions and is not specifically limited in this embodiment.

[0109] Optionally, the material of the sealing member 13 may be fluororubber or fluoroplastic, etc., which may be selected according to actual conditions and is not specifically limited in this embodiment.

[0110] Please also read Figure 3 and Figure 7 In some embodiments, the seal 13 includes a second main body portion 13a and a second step portion 13b connected to each other, the second main body portion 13a is connected between the outer periphery of the first main body portion 11a and the inner wall surface of the through hole 100, the second step portion 13b is connected to an end of the second main body portion 13a close to the second side 102, and the second step portion 13b is at least partially located between the first step portion 11b and the second side 102.

[0111] In this way, the first main body portion 11a can fix the second main body portion 13a in the radial direction of the mounting hole 110, and the first step portion 11b can carry the second step portion 13b and fix the second step portion 13b in the axial direction of the mounting hole 110, or the second main body portion 13a abuts against the first main body portion 11a in the radial direction of the mounting hole 110, and the second step portion 13b abuts against the first step portion 11b in the axial direction of the mounting hole 110, so that the seal 13 is better fixed, and the second step portion 13b of the seal 13 can be better compressed between the first step portion 11b and the cover plate 10, thereby improving the sealing effect of the seal 13, and the second main body portion 13a and the second step portion 13b of the seal 13 extend in two directions (axial and radial directions of the mounting hole 110), which can increase the contact area between the seal 13 and the mounting member 11 and the cover plate 10, and further improve the sealing effect of the seal 13.

[0112] Optionally, the second main body portion 13a may be a columnar structure or a block structure, etc., and the second step portion 13b may be an annular structure or a plate structure around the axial direction of the mounting hole 110, etc. The specific selection can be made according to actual conditions and is not specifically limited in this embodiment.

[0113] In some embodiments, the top cover assembly 1 further includes a lower plastic 14, which is disposed on the second side 102 and connected to the first step portion 11b. The lower plastic 14 is used to support the cover plate 10, and the first step portion 11b also serves to support the lower plastic 14, thereby achieving structural reuse and making the structure of the top cover assembly 1 relatively simple.

[0114] It can be seen that in the top cover assembly 1 of the present application, the upper plastic 12 is arranged between the cover plate 10 and the mounting member 11, and the upper plastic 12 can limit the radial position of the mounting member 11 relative to the cover plate 10 in the through hole 100. At the same time, the fixing portion arranged on the upper plastic 12 can play a fixing role on the mounting member 11 in the first direction X, and can limit the position of the mounting member 11 relative to the cover plate 10 in the first direction X, so that the mounting member 11 is fixed relative to the cover plate 10 in the radial direction of the through hole 100 and in the first direction X (i.e., the axial direction of the through hole 100). The mounting hole 110 of the mounting member 11 can be used to pass through the pole, so that the pole can be welded with the mounting member 11, and the mounting member 11 can fix the seal 13 to the cover plate 10 and compress the seal 13 to improve the sealing effect of the seal 13. Therefore, such a top cover assembly 1 does not need to be assembled together with the pole during the assembly process. After the top cover assembly 1 is assembled, the pole can be welded to the mounting member 11 when assembling the energy storage device. There is no need to use the riveting process of the pole, so that the size design of the pole is more flexible, and the conductive efficiency of the pole will not be affected by the size limit of the pole. In addition, when assembling the energy storage device, the pole can be welded to the current collector of the energy storage device first, and then the top cover assembly 1 is covered on the shell of the energy storage device. The pole can pass through the mounting hole 110 and be welded to the mounting hole 110. The assembly process is relatively simple, and it is easy to control the assembly tolerance of the top cover assembly 1 and the shell, and there is no need to use a foldable current collector, which can reduce the resistance of the current collector itself, that is, it can reduce the internal resistance of the energy storage device, thereby reducing power loss and improving the output efficiency of the energy storage device. In addition, by injection molding the upper plastic 12 between the inner wall surface of the through hole 100 and the outer periphery of the mounting member 11, the fixation between the upper plastic 12 and the cover plate 10 can be achieved by injection molding. At the same time, the upper plastic 12 can also be used to fix the mounting member 11 and the cover plate 10, so that the mounting member 11 does not need to be connected to the cover plate 10 with an additional fixing structure, which simplifies the fixing process between the mounting member 11 and the cover plate 10 and also simplifies the structural design of the top cover assembly 1.

[0115] Assembling method of top cover assembly 1

[0116] See also Figure 8 A second aspect of an embodiment of the present invention discloses an assembly method of a top cover assembly. The top cover assembly may be the top cover assembly of the first aspect of the embodiment of the present invention. The assembly method of the top cover assembly comprises the following steps:

[0117] S1. Install the sealing member and the mounting member in the through hole, and make the sealing member located at the outer periphery of the mounting member.

[0118] Combined with the above Figure 3 and Figure 4 As shown, in some embodiments, the sealing member 13 may be first installed on the periphery of the mounting member 11 to form a first assembly; and then the first assembly may be inserted into the through hole 100 so that the sealing member 13 is at least partially sealed and connected between the periphery of the mounting member 11 and the inner wall surface of the through hole 100. In this way, during the assembly process, there is no need to use a clamp to fix the sealing member 13 and the mounting member 11 relative to the through hole 100, which can simplify the assembly process of the top cover assembly 1.

[0119] In some embodiments, the mounting member 11 includes a first main body portion 11a and a first step portion 11b connected to each other, the first main body portion 11a is formed with a mounting hole 110, the sealing member 13 includes a second main body portion 13a and a second step portion 13b connected to each other, the second main body portion 13a is connected between the outer periphery of the first main body portion 11a and the inner wall surface of the through hole 100, the second step portion 13b is connected to an end of the second main body portion 13a close to the second side 102, and the second step portion 13b is at least partially located between the first step portion 11b and the second side 102, and the step of installing the sealing member 13 on the outer periphery of the mounting member 11 to form a first component is to sleeve the second main body portion 13a of the sealing member 13 on the outer periphery of the first main body portion 11a of the mounting member 11, and the second step portion 13b of the sealing member 13 abuts against the first step portion 11b. In this way, the seal 13 can be directly sleeved on the outer periphery of the mounting member 11, and the first step portion 11b can support the seal 13, so that the seal 13 and the mounting member 11 form a first component, which can facilitate the installation of the seal 13 and the mounting member 11 in the through hole 100.

[0120] S2. An upper plastic is arranged in the through hole so that the upper plastic is connected between the outer periphery of the mounting member and the inner wall surface of the through hole. In some embodiments, an upper plastic 12 is formed by injection molding in the through hole 100, and the upper plastic 12 is injection molded to be connected to the outer periphery of the mounting member 11 and the inner wall surface of the through hole 100. In this way, on the one hand, the injection molding process can make the upper plastic 12 and the mounting member 11 and the cover plate 10 more tightly connected, which can better play the role of fixing the mounting member 11 and the cover plate 10, and there is no need to set up other additional structures to fix the upper plastic 12, the mounting member 11 and the cover plate 10, thereby simplifying the structure of the top cover assembly 1. On the other hand, the injection molding process is relatively simple, which can reduce the difficulty of processing the upper plastic 12.

[0121] By adopting such an assembly method, the top cover assembly 1 does not need to be assembled together with the pole during the assembly process, and there is no need to adopt the riveting process of the pole. The assembly process is relatively simple, and the size design of the pole is relatively flexible. At the same time, by adopting the injection molding process, on the one hand, the connection between the upper plastic 12 and the mounting member 11 and the cover plate 10 can be made tighter, and it can play a certain role in fixing the mounting member 11 and the cover plate 10. On the other hand, the injection molding process is relatively simple, which can reduce the processing difficulty of the upper plastic 12.

[0122] Energy storage device 2

[0123] Please also read Fig. 9 and Fig.10 The third aspect of an embodiment of the present invention discloses an energy storage device 2, which includes a shell 20, a battery cell 21, a current collector 22, a pole 23 and a top cover assembly 1 as described in the first aspect of the above embodiment. The shell 20 is provided with a receiving cavity, and the receiving cavity has a first opening. The battery cell 21 and the current collector 22 are arranged in the receiving cavity. The current collector 22 is connected to a side of the battery cell 21 facing the first opening. The cover plate 10 is connected to the shell 20 to close the first opening. The pole 23 is arranged in the mounting hole 110 and connected to the current collector 22.

[0124] The energy storage device 2 provided in the third aspect of the embodiment of the present invention adopts the top cover assembly 1 of the first aspect of the embodiment of the present invention, and the upper plastic 12 is arranged between the cover plate 10 and the mounting member 11. The upper plastic 12 can limit the radial position of the mounting member 11 relative to the cover plate 10 in the through hole 100. At the same time, the fixing portion arranged on the upper plastic 12 can play a fixing role on the mounting member 11 in the first direction X, and can limit the position of the mounting member 11 relative to the cover plate 10 in the first direction X, so that the mounting member 11 is fixed relative to the cover plate 10 in the radial direction of the through hole 100 and in the first direction X (i.e., the axial direction of the through hole 100). The mounting hole 110 of the mounting member 11 can be used to pass through the pole, so that the pole can be welded with the mounting member 11, and the mounting member 11 can fix the seal 13 to the cover plate 10 and compress the seal 13 to improve the sealing effect of the seal 13. Therefore, during the assembly process of the energy storage device 2 of the present invention, the top cover assembly 1 and the pole 23 can be assembled separately. After the top cover assembly 1 is assembled, the pole 23 and the mounting member 11 can be welded when the energy storage device 2 is assembled. There is no need to adopt the riveting process of the pole 23, so that the size design of the pole 23 is more flexible, and the conductive efficiency of the pole 23 will not be affected by the size limitation of the pole 23.

[0125] In addition, since the top cover assembly 1 and the pole 23 are detachably arranged, when assembling the energy storage device 2, the pole 23 and the current collector 22 of the energy storage device 2 can be welded first, and then the top cover assembly 1 is covered on the shell 20 of the energy storage device 2. The pole 23 can pass through the mounting hole 110, and then the pole 23 and the mounting member 11 are welded. The assembly process is relatively simple, and it is easy to control the assembly tolerance of the top cover assembly 1 and the shell 20. There is no need to use a foldable current collector 22, which can reduce the resistance of the current collector 22 itself, that is, it can reduce the internal resistance of the energy storage device 2, thereby reducing power loss and improving the output efficiency of the energy storage device 2.

[0126] Optionally, the energy storage device 2 may be a cylindrical battery or a square battery, etc., which may be selected according to actual conditions and is not specifically limited in this embodiment.

[0127] In this embodiment, the energy storage device 2 generally includes two current collectors 22 and two poles 23. The two current collectors 22 are respectively a positive current collector and a negative current collector, and the two poles 23 are respectively a positive pole and a negative pole. The positive pole is connected to the positive current collector, and the negative pole 23 is connected to the negative current collector.

[0128] When the energy storage device 2 is a cylindrical battery, the positive electrode column and the negative electrode column are respectively arranged at both ends of the cylindrical battery, and the top cover assembly 1 disclosed in the first aspect of the embodiment of the present invention can be arranged at both ends or any one end of the cylindrical battery, for example, Fig.10As shown, a top cover assembly 1 is disposed at one end of the energy storage device 2, and a mounting hole 110 of the top cover assembly 1 is connected to a negative electrode column (which may also be a positive electrode column).

[0129] When the energy storage device 2 is a square battery, the positive electrode column and the negative electrode column are arranged at the same end of the circular battery, and one end of the energy storage device 2 is provided with a top cover assembly 1 disclosed in the first aspect of the embodiment of the present invention, the top cover assembly 1 includes a cover plate 10, two mounting members 11, two upper plastics 12 and two sealing members 13, the cover plate 10 is provided with two through holes 100 passing through the cover plate 10 along the first direction X, the two mounting members 11, the two upper plastics 12 and the two sealing members 13 are respectively arranged in the two through holes 100, and the positive electrode column and the negative electrode column are respectively arranged in the mounting holes 110 of the two mounting members 11.

[0130] In some embodiments, the current collector 22 has a second surface 220 and a third surface 221 along its thickness direction, the pole 23 is welded to the second surface 220, and the battery cell 21 is welded to the third surface 221. By making the current collector 23 have a second surface 220 and a third surface 221 along its thickness direction, the welding of the current collector 22 with the pole 23 and the battery cell 21 can be facilitated.

[0131] In some embodiments, the current collector 22 is constructed as a single-layer sheet structure at least in the portion corresponding to the pole 23. Optionally, the current collector 22 is constructed as a single-layer sheet structure in the portion corresponding to the pole 23, and the current collector 22 can also be constructed as a single-layer sheet structure as a whole, which can be selected according to actual conditions. Fig.10 As shown, the current collector 22 is constructed as a single-layer sheet structure as a whole, and its two surfaces along the thickness direction are the second surface 220 and the third surface 221 mentioned above.

[0132] Since the energy storage device 2 of this embodiment can first weld the pole 23 to the current collector 22 of the energy storage device 2, and then cover the top cover assembly 1 on the shell 20 of the energy storage device 2, the pole 23 can pass through the mounting hole 110, and then the pole 23 is connected and fixed to the mounting hole 110, the welding of the current collector 22, the pole 23 and the battery cell 21 can be achieved without using a foldable current collector 22, and the current collector 22 can be constructed as a single-layer sheet structure at least in the portion corresponding to the pole 23, which can simplify the structure of the current collector 22 and reduce the production cost of the energy storage device 2. At the same time, the resistance of the current collector 22 itself can be reduced, that is, the internal resistance of the energy storage device 2 can be reduced, thereby reducing power loss and improving the output efficiency of the energy storage device 2.

[0133] In some embodiments, the pole 23 is flush with or protrudes from the mounting member 11. In this way, the upper surface of the pole 23 can be flush with or higher than the upper surface of the mounting member 11, which can facilitate electrical connection between the pole 23 and other components.

[0134] In some embodiments, no pressing block is provided on the pole 23 .

[0135] Since the pole 23 of the present embodiment does not need to adopt the riveting process, the size design of the pole 23 is more flexible, and the conductive efficiency of the pole 23 will not be affected by the size limitation of the pole 23. The pole 23 can also be directly physically connected to the outside. Therefore, there is no need to set a pressure block on the pole 23, which can simplify the structural design of the energy storage device 2.

[0136] Assembly method of energy storage device 2

[0137] See also Fig.11 A fourth aspect of an embodiment of the present invention discloses an assembly method of an energy storage device. The energy storage device may be an energy storage device as in the third aspect of an embodiment of the present invention. The assembly method of the energy storage device includes the assembly method of the top cover assembly of the second aspect of the above embodiment and the following steps:

[0138] S3. Install the battery cell in the accommodating cavity of the shell.

[0139] Combined with the above Fig. 9 and Fig.10 As shown, the housing 20 can support the battery core 21 , so as to facilitate installation of other components on the battery core 21 in subsequent steps.

[0140] S4. Weld the current collector to the battery cell and the electrode.

[0141] In this way, the welding of the pole 23 and the current collector 22 can be completed before installing the top cover assembly 1, thereby avoiding the difficulty in welding the pole 23 and the current collector 22 due to the shielding of the top cover assembly 1.

[0142] Optionally, the current collector 22 can be welded to the battery cell 21 first, and then the pole 23 can be welded to the current collector 22. Alternatively, the current collector 22 and the pole 23 can be welded, and then the assembly formed by the current collector 22 and the pole 23 can be welded to the battery cell 21. The specific selection can be made according to actual conditions and is not specifically limited in this embodiment.

[0143] S5. Cover the assembled cover plate of the top cover assembly on the shell to close the first opening, and allow the pole welded to the current collector to pass through the mounting hole.

[0144] Since a mounting hole for installing the pole 23 is reserved on the mounting member 11 of the top cover assembly 1, the pole 23 can pass through the mounting hole of the mounting member 11 when the cover plate 10 is covered on the shell 20, thereby completing the assembly of the energy storage device 2, and the assembly process is relatively simple.

[0145] In some embodiments, after completing step S5, the cover plate 10 and the housing 20 may be welded, and the pole 23 may be welded to the mounting hole, thereby completing the fixing of the various components of the energy storage device 2. Optionally, the cover plate 10 and the housing 20 may be welded first, and then the pole 23 may be welded to the mounting hole, or the pole 23 may be welded to the mounting hole first, and then the cover plate 10 and the housing 20 may be welded. The specific selection may be made according to actual conditions and is not specifically limited in this embodiment.

[0146] Among them, in actual production, the step of assembling the top cover assembly 1 can be completed before step S5. For example, the assembly of the top cover assembly 1 can be completed before step S3, or after completing step S4 and before step S5, and so on. The specific selection can be made according to the actual situation and is not specifically limited in this embodiment.

[0147] By adopting such an assembly method, during the assembly process of the energy storage device 2, the top cover assembly 1 and the pole 23 can be assembled separately, and there is no need to adopt the riveting process of the pole 23, so that the size design of the pole 23 is more flexible, and the conductive efficiency of the pole 23 will not be affected by the size limitation of the pole 23. In addition, there is no need to adopt a foldable current collector 22, the assembly process is relatively simple, and it is easy to control the assembly tolerance of the top cover assembly 1 and the shell 20, and the resistance of the current collector 22 itself can be reduced, that is, the internal resistance of the energy storage device 2 can be reduced, thereby reducing the power loss and improving the output efficiency of the energy storage device 2.

[0148] Energy storage module 3

[0149] See also Fig.12 A fifth aspect of an embodiment of the present invention discloses an energy storage module 3, and the energy storage module 3 includes the energy storage device 2 of the third aspect of the above embodiment.

[0150] Optionally, the energy storage module 3 may include a plurality of energy storage devices 2, for example, two, three, four or five, etc., which may be selected according to actual conditions and are not specifically limited in this embodiment.

[0151] In some embodiments, the energy storage module 3 includes at least two energy storage devices 2 and a bar 30 , and the poles 23 of two adjacent energy storage devices 2 are connected to the bar 30 .

[0152] Since the pole 23 of this embodiment does not need to adopt the riveting process, the size design of the pole 23 is more flexible, which can avoid or reduce the situation where the conductive efficiency of the pole 23 is affected by the size limitation of the pole 23. The pole 23 of the energy storage device 2 can be directly connected to the bar 30 to achieve electrical connection between the two energy storage devices 2, and can simplify the structural design of the energy storage device 2.

[0153] Energy storage system 4

[0154] A sixth aspect of an embodiment of the present invention discloses an energy storage system 4, which includes the energy storage device 2 of the third aspect of the above embodiment, or the energy storage system 4 includes the energy storage module 3 of the fifth aspect of the above embodiment.

[0155] See also Fig.13 , this application Fig.13 The energy storage system 4 is described by taking the shared energy storage scenario on the generation / distribution side as an example. The energy storage device 2 and the energy storage module 3 of the present application are not limited to the energy storage scenario on the generation / distribution side.

[0156] The present application provides an energy storage system 4, which includes: a high-voltage cable 40, a first electric energy conversion device 41, a second electric energy conversion device 42 and an energy storage device 2 provided in the present application. In the case of power generation, the first electric energy conversion device 41 and the second electric energy conversion device 42 are used to convert other forms of energy into electric energy, connected to the high-voltage cable 40 and supplied to the power distribution network for use. When the power load is low and the first electric energy conversion device 41 and the second electric energy conversion device 42 generate excess power, the excess power is stored in the energy storage device 2, thereby reducing the wind and solar power abandonment rates and improving the problem of new energy power generation and consumption. When the power load is high, the power grid issues an instruction to transmit the power stored in the energy storage device 2 in conjunction with the high-voltage cable 40 in a grid-connected mode to the power consumption side, thereby providing peak shaving, frequency regulation, standby and other services for the power grid operation, giving full play to the peak shaving role of the power grid, promoting peak shaving and valley filling of the power grid, and alleviating the power supply pressure of the power grid.

[0157] Optionally, the first electric energy conversion device 41 and the second electric energy conversion device 42 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy and mechanical energy into electric energy.

[0158] The number of energy storage devices 2 can be multiple, for example, two, three or four, and multiple energy storage devices 2 are connected in series or in parallel. Multiple energy storage devices 2 can be supported and electrically connected by isolation plates (not shown). An energy storage box can also be provided outside the energy storage device 2 to accommodate the energy storage device 2.

[0159] The top cover assembly, energy storage device, energy storage module and energy storage system disclosed in the embodiments of the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the top cover assembly, energy storage device, energy storage module and energy storage system of the present invention and their core ideas; at the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A top cover assembly, characterized in that: The top cover assembly is applied to an energy storage device, and the top cover assembly comprises: A cover plate, the cover plate having a first side and a second side opposite to each other along a first direction, the first side being provided with a through hole penetrating along the first direction to the second side; A mounting member, the mounting member is arranged in the through hole, the mounting member is provided with a mounting hole penetrating along the first direction, and the mounting member is configured to be welded to the pole of the energy storage device to fix the pole in the mounting hole; an upper plastic, the upper plastic being connected to the outer periphery of the mounting member, the upper plastic being located in the through hole and disposed close to the first side, the upper plastic being provided with a fixing portion, the fixing portion being connected to the mounting member to fix the mounting member along the first direction; and A sealing member is at least partially connected between the mounting member and the inner wall surface of the through hole, and the sealing member is arranged close to the second side.

2. The top cover assembly according to claim 1, characterized in that: The upper plastic is configured to be formed by injection molding between the inner wall surface of the through hole and the outer periphery of the mounting member.

3. The top cover assembly according to claim 2, characterized in that: The mounting member is provided with a first engaging portion, the fixing portion is configured as a second engaging portion, the first engaging portion is engaged and connected to the second engaging portion, one of the first engaging portion and the second engaging portion is a protrusion, and the other is a depression.

4. The top cover assembly according to claim 3, characterized in that: A third engaging portion is disposed on the inner wall surface of the through hole, a fourth engaging portion is disposed on the upper plastic, the first engaging portion is engaged and connected to the second engaging portion, one of the third engaging portion and the fourth engaging portion is a protrusion, and the other is a depression.

5. The top cover assembly according to claim 1, characterized in that: In the first direction, the mounting member protrudes from the upper plastic, and the length of the portion of the mounting member protruding from the upper plastic is d, and the distance d satisfies: d≤0.5mm, and / or d≥0.3mm.

6. The top cover assembly according to any one of claims 1 to 5, characterized in that: The mounting member comprises a first main body and a first step portion connected to each other, the first main body is provided with the mounting hole, the first main body is arranged in the through hole, the upper plastic is connected to the outer periphery of the first main body, the first step portion is connected to an end of the first main body close to the second side, and the first step portion is at least partially arranged corresponding to the second side; The seal includes a second main body portion and a second step portion which are connected to each other, the second main body portion is connected between the outer periphery of the first main body portion and the inner wall surface of the through hole, the second step portion is connected to an end of the second main body portion close to the second side, and the second step portion is at least partially located between the first step portion and the second side.

7. An energy storage device, characterized in that: The energy storage device includes a shell, a battery cell, a current collector, a pole and a top cover assembly as described in any one of claims 1 to 6, the shell is provided with a accommodating cavity, the accommodating cavity has a first opening, the battery cell and the current collector are arranged in the accommodating cavity, the current collector is connected to the battery cell, the cover plate is connected to the shell to close the first opening, the pole is arranged in the mounting hole and connected to the current collector.

8. The energy storage device according to claim 7, characterized in that: The current collector has a second surface and a third surface along its thickness direction, the pole is welded to the second surface, the battery cell is welded to the third surface, and the current collector is constructed as a single-layer sheet structure at least in a portion corresponding to the pole.

9. An energy storage system, characterized in that: The energy storage system comprises the energy storage device as claimed in claim 7 or 8.

10. A method for assembling a top cover assembly, characterized in that: The top cover assembly comprises the top cover assembly according to any one of claims 1 to 6, and the assembling method comprises: Installing the sealing member and the mounting member in the through hole, and making the sealing member located at the outer periphery of the mounting member; The upper plastic is arranged in the through hole so that the upper plastic is connected between the outer periphery of the mounting member and the inner wall surface of the through hole.

11. The method for assembling a top cover assembly according to claim 10, characterized in that: The step of installing the sealing member and the mounting member in the through hole and making the sealing member located at the periphery of the mounting member comprises: Mounting the sealing member on the outer periphery of the mounting member to form a first assembly; The first component is inserted into the through hole so that the sealing member is sealed and connected between the outer periphery of the mounting member and the inner wall surface of the through hole.

12. The method for assembling a top cover assembly according to claim 10, characterized in that: The upper plastic is arranged in the through hole so that the upper plastic is connected between the outer periphery of the mounting member and the inner wall surface of the through hole, comprising: The upper plastic is formed by injection molding in the through hole, and the upper plastic is connected to the outer periphery of the mounting member and the inner wall surface of the through hole by injection molding.

13. A method for assembling an energy storage device, characterized in that: The energy storage device comprises the energy storage device according to claim 7 or 8, and the assembly method comprises the assembly method of the top cover assembly according to any one of claims 10 to 12 and the following steps: Installing the battery cell in the accommodating cavity of the shell; Welding the current collector to the battery cell and the pole; The cover plate of the assembled top cover assembly is covered on the shell to close the first opening, and the pole welded with the current collector is passed through the mounting hole.

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