Energy storage device, energy storage apparatus and power system

Abstract

An energy storage device (100), an energy storage apparatus and a power system. The energy storage device (100) comprises a middle housing (10), an end cover assembly (20), a first side housing (31), a second side housing (32), and a battery cell (50), wherein the middle housing (10) and a cover plate (21) of the end cover assembly (20) enclose a first space (40); at least one of the first side housing (31) and the second side housing (32) which are oppositely arranged and spaced apart from each other comprises a frame body (33) and an elastic film (34), the frame body (33) is in the shape of an endless ring, and the frame body (33) is connected to both the middle housing (10) and the cover plate (21); the elastic film (34) comprises a main body portion (341) and an edge portion (342), the edge portion (342) being connected to a peripheral edge of the main body portion (341); the frame body (33) is provided with a mounting groove (331), an opening of the mounting groove (331) faces a first space (40), the edge portion (342) extends into the mounting groove (331) and is connected to the frame body (33), and the main body portion (341) protrudes relative to the frame body (33) in the direction away from the middle housing (10); and the main body portion (341) encloses a second space (3411) in communication with the first space (40), the battery cell (50) is accommodated in the first space (40) and the second space (3411), and the elastic film (34) elastically abuts against a large surface of the battery cell (50).

Description

Energy storage devices, energy storage equipment and power systems

[0001] This application claims priority to Chinese Patent Application No. 202411433116.4, filed on October 14, 2024, entitled “Energy Storage Device, Energy Storage Equipment and Power System”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of energy storage technology, specifically to an energy storage device, energy storage equipment, and power system. Background Technology

[0003] Energy storage devices typically consist of a housing and battery cells, with the battery cells housed within the housing. The thickness of the battery cells changes during assembly, formation, and subsequent use. Current energy storage devices have a fixed structure, which cannot provide sufficient preload to the battery cells, thus failing to meet the operational requirements of the energy storage device. Summary of the Invention

[0004] The purpose of this application is to provide an energy storage device, energy storage equipment, and power system that solves the problem that the energy storage device cannot provide sufficient preload to the battery cell and can improve battery capacity.

[0005] To achieve the objectives of this application, the following technical solution is provided:

[0006] In a first aspect, this application provides an energy storage device, including an intermediate shell, an end cap assembly, a first side shell, a second side shell, and a battery cell. The intermediate shell includes a base plate, a first side plate, and a second side plate, which are connected to the base plate and are located on the same side of the base plate, with the first side plate and the second side plate being spaced apart from each other. The end cap assembly includes a cover plate, which is connected to the first side plate and the second side plate and is opposite to the base plate. The intermediate shell and the cover plate enclose a first space. The first side shell and the second side shell are all connected to the base plate, the first side plate, the second side plate, and the cover plate, and are spaced apart from each other. At least one of the first side shell and the second side shell includes a frame and an elastic membrane, with the frame being connected end-to-end. The frame is annular, and the frame body is connected to the bottom plate, the first side plate, the second side plate, and the cover plate; the elastic membrane includes a main body and an edge portion, the edge portion being connected to the four periphery of the main body; the frame body has a mounting groove, the opening of the mounting groove facing the first space, the edge portion extending into the mounting groove and connected to the frame body, the main body protruding relative to the frame body in a direction away from the intermediate shell; the main body encloses a second space, the second space being connected to the first space, and a battery cell being housed in the first space and the second space. In a cross-section along the height direction of the energy storage device, the battery cell is a racetrack-shaped wound battery cell or a rectangular stacked battery cell. The direction in which the first side shell and the second side shell face each other is the thickness direction of the battery cell, and the elastic membrane elastically abuts against the large surface of the battery cell.

[0007] The energy storage device of this application embodiment includes a frame and an elastic membrane by setting at least one of the first side shell and the second side shell. The main body of the elastic membrane protrudes from the side of the frame facing away from the middle shell and has a corner at the junction of the main body and the edge. In addition to being housed in the first space enclosed by the middle shell and the cover plate, the battery cell can also be housed in the second space enclosed by the main body of the elastic membrane. Therefore, it can accommodate a larger volume battery cell, which is beneficial to increasing the battery capacity. Compared with the side shell, which is a non-deformable structure, it allows the battery cell to have a larger expansion space when the thickness changes. At the same time, the deformation of the elastic membrane can provide tension reaction on the large surface of the battery cell, thereby providing sufficient pre-tightening force to the battery cell to meet the working requirements of the energy storage device.

[0008] Secondly, this application also provides an energy storage device, including an energy storage device as described in any one of the various embodiments of the first aspect and a reinforcing plate, the reinforcing plate being disposed on at least one side of the energy storage device in the thickness direction.

[0009] The energy storage device of this application provides an additional preload force on the battery cell in the thickness direction by providing a reinforcing plate on at least one side in the thickness direction, in addition to the preload force provided by the elastic membrane, thereby meeting the working requirements of the energy storage device.

[0010] Thirdly, this application also provides a power system including electrical equipment and an energy storage device as described in any one of the various embodiments of the first aspect, wherein the energy storage device supplies power to the electrical equipment; or an energy storage device as described in any one of the various embodiments of the second aspect, wherein the energy storage device supplies power to the electrical equipment.

[0011] The power system in this application employs the energy storage device or energy storage equipment in the embodiments of this application. The energy storage device or energy storage equipment can provide sufficient preload to the battery cells, thereby meeting the working requirements of the energy storage device or energy storage equipment. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0013] Figure 1 is a perspective view of an energy storage device according to an embodiment;

[0014] Figure 2 is an exploded schematic diagram of an energy storage device according to an embodiment;

[0015] Figure 3 is a partial cross-sectional schematic diagram of an energy storage device according to an embodiment;

[0016] Figure 4 is a partial cross-sectional schematic diagram of an energy storage device according to another embodiment;

[0017] Figure 5 is a partial cross-sectional schematic diagram of an energy storage device according to another embodiment;

[0018] Figure 6 is a partial cross-sectional schematic diagram of an energy storage device according to another embodiment.

[0019] Explanation of reference numerals in the attached drawings: 100-Energy storage device; 10-Intermediate shell, 11-Bottom plate, 12-First side plate, 13-Second side plate, 14-Protrusion, 15-Main shell, 16-Side shell, 161-Connecting surface; 20-End cap assembly, 21-Cover plate, 22-Connecting piece, 23-Pole post; 31-First side shell, 32-Second side shell, 33-Frame, 331-Mounting groove, 3311-Snap-fit ​​groove, 3312-Communication groove, 332-First frame, 3321-First plate, 3322-Second plate, 333-Second frame, 3331-Third plate, 3332-Fourth plate, 3333-Fifth plate, 334-Third frame, 3341-Step, 3342-Step surface, 335-Fourth frame, 34-Elastic membrane, 341-Main body, 3411-Second space, 342-Edge part, 3421-Body, 3422-Flange, 351-Fifth frame, 352-First connecting frame, 3521-First outer surface, 353-Sixth frame, 354-Second connecting frame, 3541-Second outer surface, 355-Seventh frame, 361-Eighth frame, 362-Ninth frame; 40 - First space; 50 - Battery cell; X - Width direction of energy storage device, Y - Thickness direction of energy storage device, Z - Height direction of energy storage device. Detailed Implementation

[0020] 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 a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] It should be noted that when a component is said to be "fixed" to another component, it can be directly on the other component or it can be in a middle component. When a component is said to be "connected" to another component, it can be directly connected to the other component or it may be in a middle component.

[0022] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0023] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0024] Please refer to Figures 1 and 2. This application provides an energy storage device 100, including an intermediate shell 10, an end cap assembly 20, a first side shell 31, a second side shell 32, and a battery cell 50. The overall shape of the assembled energy storage device 100 is approximately a cuboid. For ease of explanation, the XYZ directions are defined, where the X direction is the width direction of the energy storage device 100, the Y direction is the thickness direction of the energy storage device 100, and the Z direction is the height direction of the energy storage device 100.

[0025] The intermediate shell 10 includes a bottom plate 11, a first side plate 12 and a second side plate 13. The first side plate 12 and the second side plate 13 are connected to the bottom plate 11, and the first side plate 12 and the second side plate 13 are both located on the same side of the bottom plate 11. The first side plate 12 and the second side plate 13 are arranged at intervals relative to each other.

[0026] The base plate 11, the first side plate 12, and the second side plate 13 are all generally flat. The base plate 11 extends along the X direction, and the first side plate 12 and the second side plate 13 are respectively connected to the two sides of the base plate 11 in the X direction. Both the first side plate 12 and the second side plate 13 extend along the Z direction. The intermediate shell 10 can be a one-piece structure, that is, the base plate 11, the first side plate 12, and the second side plate 13 are a single piece. For example, it can be formed by bending a long plate, or it can be formed by other processes, without limitation. The intermediate shell 10 can also be connected and fixed by welding, screwing, riveting, or other processes.

[0027] The end cap assembly 20 includes a cover plate 21, which is connected to the first side plate 12 and the second side plate 13 and is opposite to the base plate 11. The cover plate 21 can be made of aluminum, steel, etc., and a cover plate 21 made of aluminum is generally called a plain aluminum sheet. The cover plate 21 is also roughly flat and extends along the X direction. The two ends of the cover plate 21 in the X direction are connected to the first side plate 12 and the second side plate 13 respectively. The connection method can be welding, screwing, riveting, etc. The materials of the first side plate 12 and the second side plate 13 can be aluminum, carbon steel (such as model SPCC), stainless steel (model SUS304, SUS316, etc.), without limitation.

[0028] The end cap assembly 20 also includes an insulating component (not shown), a terminal post 23, a connecting piece 22, and a top patch (not shown). The insulating component is located on the surface of the cover plate 21 facing the base plate 11. The cover plate 21 and the insulating component have holes through which the terminal post 23 passes, such that one end of the terminal post 23 is located at the insulating component, and the other end extends out of the cover plate 21. The connecting piece 22 connects the end of the terminal post 23 located at the insulating component to the tab of the battery cell 50. The top patch is attached to the surface of the cover plate 21 facing away from the base plate 11, exposing the terminal post 23. The connecting piece 22 and the terminal post 23 are used to transmit electrical energy, the insulating component separates the connecting piece 22 and the cover plate 21 to prevent short circuits, and the top patch provides insulation protection. A positive and negative terminal can be provided simultaneously on an end cap assembly 20. Specifically, the terminal post 23 includes a positive terminal post 23 and a negative terminal post 23, and the connecting piece 22 includes a positive connecting piece 22 and a negative connecting piece 22. The positive terminal post 23 and the negative terminal post 23 are spaced apart on the same cover plate 21. The positive connecting piece 22 is connected to the positive terminal post 23 and the positive tab, and the negative connecting piece 22 is connected to the negative terminal post 23 and the negative tab. The specific structure of the end cap assembly 20 can refer to any feasible solution, and the embodiments of this application are not limited.

[0029] The first side shell 31 and the second side shell 32 are all connected to the bottom plate 11, the first side plate 12, the second side plate 13 and the cover plate 21, and the first side shell 31 and the second side shell 32 are arranged at intervals relative to each other.

[0030] The first side shell 31 and the second side shell 32 are generally plate-shaped. The first side shell 31 and the second side shell 32 are arranged at intervals relative to each other in the Y direction. The first side shell 31 and the second side shell 32 are respectively connected to the two sides of the middle shell 10 and the cover plate 21 in the Y direction, so as to jointly enclose and form a storage space.

[0031] In this embodiment, at least one of the first side shell 31 and the second side shell 32 includes a frame 33 and an elastic membrane 34. One of the first side shell 31 and the second side shell 32 may include both a frame 33 and an elastic membrane 34, while the other may be a flat plate. The flat side shell may be integrally formed with the intermediate shell 10, or it may be connected and fixed to the intermediate shell 10 by welding, screwing, riveting, or other methods. Alternatively, both the first side shell 31 and the second side shell 32 may include a frame 33 and an elastic membrane 34, with essentially the same structure.

[0032] Among them, the frame body 33 serves as a support base, and the elastic membrane 34 is installed on the frame body 33. The frame body 33 can be made of metal, which can be the same as or different from the materials of the middle shell 10 and the cover plate 21. Specifically, the material of the frame body 33 can be AL3003 (aluminum alloy with manganese as the main alloy element), SPCC (cold-rolled carbon steel sheet), Sus304 (304 stainless steel), etc. The elastic membrane 34 is made of elastic material, can provide elastic tension after deformation and has the ability to recover to its original state. At the same time, the elastic membrane 34 also has the property of being resistant to electrolyte corrosion. The specific material of the elastic membrane 34 can be EPDN (ethylene propylene diene monomer), fluororubber, PFA (tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer), etc.

[0033] Please refer to FIGS. 2 and 3. The frame body 33 is in a ring shape with its head and tail connected, and the frame body 33 is connected to the bottom plate 11, the first side plate 12, the second side plate 13, and the cover plate 21.

[0034] The frame body 33 generally forms a "square" - shaped structure, which includes four side frames that extend in a generally straight - line shape. The four side frames are connected in sequence with their heads and tails to form a ring, and adjacent side frames are generally perpendicular. The four side frames are generally located in the same plane. The four side frames are respectively connected to the bottom plate 11, the first side plate 12, the second side plate 13, and the cover plate 21. The connection method can be welding, screwing, riveting, etc., without limitation.

[0035] Referring to FIG. 3, the elastic membrane 34 includes a main body portion 341 and an edge portion 342. The edge portion 342 is connected to the four - perimeter edges of the main body portion 341, and there are corners at the joints between the main body portion 341 and the edge portion 342. The frame body 33 has an installation groove 331, the opening of the installation groove 331 faces the first space 40, the edge portion 342 extends into the installation groove 331 and is connected to the frame body 33, and the main body portion 341 protrudes away from the middle shell 10 relative to the frame body 33. The middle shell 10 and the cover plate 21 enclose the first space 40, and the main body portion 341 encloses a second space 3411, and the second space 3411 is connected to the first space 40.

[0036] The elastic membrane 34 can be an integral structure. For example, the main body portion 341 and the edge portion 342 are an integral structure formed by injection molding. The elastic membrane 34 can also be a split - type structure formed as a whole through connection. For example, the main body portion 341 and the edge portion 342 can be formed as a whole through bonding, heat - melting connection, etc.

[0037] The shape of the main body portion 341 when flattened is adapted to the shape of the space enclosed by the frame body 33. That is, when the main body portion 341 is flattened, it is generally rectangular in shape, and its thickness direction is the Y - direction. The edge portion 342 is connected to the installation groove 331 of the frame body 33, which can be snap - connection or any other feasible connection method such as bonding, without limitation.

[0038] The battery cell 50 is housed in the first space 40 and the second space 3411. The battery cell 50 is also generally cuboid in shape, with its width, thickness, and height directions corresponding to those of the aforementioned energy storage device 100. The battery cell 50 may include a bare battery cell 50, tabs, Mylar membranes, etc. A tab is connected to the end of the bare battery cell 50 facing the end cap assembly 20, and the tab is connected to the aforementioned connecting piece 22. The tabs include a positive tab and a negative tab, both of which may be located at the same end for connection to the same end cap assembly 20. The Mylar membrane covers the surface of the bare battery cell 50 except for the end face facing the top cover. The Mylar membrane serves to protect the bare battery cell 50. The battery cell 50 may include one or more bare battery cells 50. When there are multiple bare battery cells 50, they are arranged side-by-side and connected to the same end cap assembly 20. The specific structure of the battery cell 50 can be described with reference to any feasible scheme; this application does not limit the specific structure.

[0039] The battery cell 50 is a wound battery cell 50, and in the cross-section along the Z direction (i.e., the cross-section is perpendicular to the Z direction), the cross-section of the battery cell 50 is racetrack-shaped; or, the battery cell 50 is a laminated battery cell 50, and in the cross-section along the Z direction, the cross-section of the battery cell 50 is rectangular. Either of the above methods is acceptable and there is no specific restriction.

[0040] Referring to Figure 2, the large surface of the battery cell 50 can be any one of the two opposing surfaces of the battery cell 50 in the Y direction. When the battery cell 50 expands, it primarily expands in the Y direction, with smaller expansion in the X and Z directions. Specifically, before the energy storage device 100 is assembled and formed, the elastic membrane 34 elastically abuts against the large surface of the battery cell 50. And / or, when the energy storage device 100 is fully charged, the elastic membrane 34 elastically abuts against the large surface of the battery cell 50.

[0041] When the battery cell 50 expands in the Y direction, the edge portion 342 of the elastic membrane 34 is connected and fixed to the frame 33. The battery cell 50 can expand in the first space 40 and the second space 3411 enclosed by the intermediate shell 10, the cover plate 21, the first side shell 31 and the second side shell 32. It can further expand to the side of the frame 33 facing away from the intermediate shell 10. The battery cell 50 squeezes the elastic membrane 34, causing the part of the elastic membrane 34 that is in contact with the large surface of the battery cell 50 to deform outward in the Y direction. The tension of the deformation of the elastic membrane 34 applies an inward pulling force to the battery cell 50 in the Y direction, thereby providing a pre-tightening force to the battery cell 50.

[0042] Please refer to Figures 1 and 2. Taking the first side shell 31, which includes a frame 33 and an elastic membrane 34, and the second side shell 32, which is a flat plate, as an example, the assembly process of the energy storage device 100 is roughly as follows: Connect the end cap assembly 20 to the battery cell 50. Specifically, connect the electrode post 23 to the electrode tab through the connecting piece 22. When the battery cell 50 has two bare cells 50, the two bare cells 50 can be laid flat on the same plane and connected to the end cap assembly 20, and then the two bare cells 50 can be connected... The process of combining two bare battery cells 50 laid flat involves merging them into a single unit arranged side-by-side along the Y direction and then covering and heat-melting it with Mylar film. Next, the battery cells 50 and the end cap assembly 20 are installed into the intermediate shell 10, and the cover plate 21 of the end cap assembly 20 is connected to the intermediate shell 10. Then, the first side shell 31 and the second side shell 32 are installed. Finally, an outer film can be wrapped around the outside of the intermediate shell 10, the first side shell 31, and the second side shell 32, and a top patch is attached to the cover plate 21. The outer film serves a protective function.

[0043] In summary, the energy storage device 100 of this application embodiment includes a frame 33 and an elastic membrane 34 by providing at least one of the first side shell 31 and the second side shell 32. The main body 341 of the elastic membrane 34 protrudes from the side of the frame 33 facing away from the intermediate shell 10, and the junction of the main body 341 and the edge 342 has a corner. In addition to being housed in the first space 40 enclosed by the intermediate shell 10 and the cover plate 21, the battery cell 50 can also be housed in the second space 3411 enclosed by the main body 341 of the elastic membrane 34. Therefore, it can accommodate a larger volume battery cell 50, which is beneficial to increasing the battery capacity. Compared with the side shell being a non-deformable structure, it allows the battery cell 50 to have a larger expansion space when the thickness changes. At the same time, the deformation of the elastic membrane 34 can provide tension reaction on the large surface of the battery cell 50, thereby providing the battery cell 50 with sufficient pre-tightening force to meet the working requirements of the energy storage device 100.

[0044] In one embodiment, referring to Figures 2 and 3, the minimum distance between the first side shell 31 and the second side shell 32 is less than the thickness of the cell 50.

[0045] The first side shell 31 and the second side shell 32 are opposite each other in the Y direction. Therefore, the minimum distance between the first side shell 31 and the second side shell 32 is the minimum distance between the first side shell 31 and the second side shell 32 in the Y direction. Since the elastic membrane 34 protrudes away from the intermediate shell 10 relative to the frame 33, the minimum distance is the distance between the frames 33 of the first side shell 31 and the second side shell 32. Optionally, when one of the first side shell 31 and the second side shell 32 includes a frame 33 and an elastic membrane 34, and the other is just a flat plate, the minimum distance is the distance from the frame 33 of one to the flat plate of the other. When both the first side shell 31 and the second side shell 32 include a frame 33 and an elastic membrane 34, the minimum distance is the distance between the frame 33 of the first side shell 31 and the frame 33 of the second side shell 32.

[0046] The minimum distance between the first side shell 31 and the second side shell 32 is less than the dimension of the cell 50 in the Y direction (i.e. the thickness of the cell 50). When the cell 50 is assembled into the intermediate shell 10, the cell 50 already protrudes from the intermediate shell 10 in the Y direction. After the first side shell 31 and the second side shell 32 are assembled, the cell 50 protruding from the intermediate shell 10 pushes up the elastic membrane 34, thereby causing the elastic membrane 34 to elastically deform and apply sufficient preload to the cell 50.

[0047] Optionally, the minimum distance between the first side shell 31 and the second side shell 32 can be the same as the size of the intermediate shell 10 in the Y direction, or it can be slightly larger or slightly smaller than the size of the intermediate shell 10 in the Y direction, without any specific limitation.

[0048] By setting the minimum distance between the first side shell 31 and the second side shell 32 to be less than the thickness of the cell 50, the cell 50 is housed in the first space 40 and the second space 3411. After the first side shell 31, the intermediate shell 10 and the second side shell 32 are connected and fixed, the cell 50 elastically abuts against the elastic membrane 34. The deformation of the elastic membrane 34 can provide sufficient pre-tightening force to the cell 50, so as to avoid a significant drop in the capacity of the cell 50 during the formation stage (the first charge and discharge cycle of the cell 50) and avoid the phenomenon of a drop in the capacity of the cell 50.

[0049] In one embodiment, referring to FIG3, the mounting groove 331 includes a snap-fit ​​groove 3311 and a connecting groove 3312. The opening of the connecting groove 3312 connects to the junction of the first space 40 and the second space 3411. The other end of the connecting groove 3312 connects to the snap-fit ​​groove 3311. The spacing between the two opposite inner wall surfaces of the snap-fit ​​groove 3311 is greater than the spacing between the two opposite inner wall surfaces of the connecting groove 3312.

[0050] The edge portion 342 includes a body 3421 and a flange 3422. The body 3421 is annular and its inner four periphery is connected to the main body portion 341. The flange 3422 is connected to the outer four periphery of the body 3421. The thickness of the flange 3422 is greater than the thickness of the body 3421. The flange 3422 is received in the snap-fit ​​groove 3311. At least a portion of the body 3421 is received in the connecting groove 3312.

[0051] In this embodiment, the extension of the two opposing inner wall surfaces of the snap-fit ​​groove 3311 can be in the Y direction or at a certain angle to the Y direction. For example, the two opposing inner wall surfaces of the snap-fit ​​groove 3311 extend along the Y direction. At the connection between the frame 33 and the bottom plate 11 and the cover plate 21, the spacing between the two opposing inner wall surfaces of the snap-fit ​​groove 3311 refers to the dimension in the Z direction; at the connection between the frame 33 and the first side plate 12 and the second side plate 13, the spacing between the two opposing inner wall surfaces of the snap-fit ​​groove 3311 refers to the dimension in the X direction.

[0052] The gap dimension of the snap-fit ​​groove 3311 is larger to accommodate the thicker flange 3422. The gap dimension of the connecting groove 3312 is smaller to accommodate at least a portion of the body 3421, with the remaining portion of the body 3421 accommodated at the junction of the first space 40 and the second space 3411. The thickness of the flange 3422 is greater than the gap dimension of the connecting groove 3312, preventing the flange 3422 from retracting through the connecting groove 3312.

[0053] Optionally, the thickness of the body 3421 is 0.1mm-2mm, specifically 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, etc., without limitation. Optionally, the thickness of the flange 3422 is 0.1mm-3mm thicker than the thickness of the body 3421. In a specific embodiment, the thickness of the body 3421 is 0.4mm, and the thickness of the flange 3422 is 0.6mm.

[0054] The edge portion 342 can be a one-piece structure, for example, the body 3421 and the flange 3422 are a one-piece structure formed by injection molding. The edge portion 342 can also be a split structure that is connected to form a whole, for example, the body 3421 and the flange 3422 can be connected by bonding, hot melt connection, etc. to form a whole.

[0055] The mounting groove 331 is used to engage with the edge portion 342 of the elastic membrane 34. That is, after the flange 3422 is received in the engagement groove 3311 and at least part of the body 3421 is received in the connecting groove, the elastic membrane 34 pulls the flange 3422 when it deforms. The flange 3422 will engage with the side wall of the connecting groove 3312 facing the opening of the engagement groove 3311 without exiting through the connecting groove 3312, thus realizing the engagement connection between the elastic membrane 34 and the frame 33.

[0056] By setting the mounting groove 331, including the snap-fit ​​groove 3311 and the connecting groove 3312, and the edge portion 342 of the elastic membrane 34, including the body 3421 and the flange 3422, the connection between the elastic membrane 34 and the frame 33 can be realized with a simple structure. The structure is simple and easy to implement.

[0057] In one embodiment, referring to FIG3, the direction of the snap-fit ​​groove 3311 toward the connecting groove 3312 is at an angle to the opening direction of the connecting groove 3312. In the cross-section of the elastic membrane 34, the body 3421 is bent, and there is an angle between the body 3421 and the main body portion 341.

[0058] Optionally, the angle between the direction of the snap-fit ​​groove 3311 toward the connecting groove 3312 and the opening direction of the connecting groove 3312 can be 60°-100°, specifically 60°, 65°, 70°, 75°, 80°, 85°, 90°, 95°, 100°, etc., without limitation.

[0059] Optionally, the inner wall of the connecting groove 3312 is bent, which can be a single bend or multiple bends, and there is no specific limitation. Since at least a portion of the body 3421 is housed in the connecting groove 3312, one end of the body 3421 is connected to the main body 341, and the other end is connected to the flange 3422. The body 3421 is also bent, and the bending shape of the body 3421 can correspond to the shape of the inner wall of the connecting groove 3312.

[0060] Optionally, in the cross-section of the elastic membrane 34, the junction of the main body 341 and the body 3421 has an angle, the size of which can be 60°-110°, specifically 60°, 65°, 70°, 75°, 80°, 85°, 90°, 95°, 100°, 105°, 110°, etc., without limitation. The angle between the direction of the snap-fit ​​groove 3311 toward the connecting groove 3312 and the opening direction of the connecting groove 3312 can be the same as or different from the angle between the main body 341 and the body 3421, without specific limitation.

[0061] By setting the direction of the snap-fit ​​groove 3311 toward the connecting groove 3312 at an angle with the opening direction of the connecting groove 3312, and the connecting groove 3312 having a non-linear structure, the inner wall of the connecting groove 3312 is connected to the bent body 3421, which can enhance the snap-fit ​​effect between the edge 342 and the frame 33, and the elastic membrane 34 is not easy to fall off from the frame 33.

[0062] In one embodiment, referring to FIG3, the frame 33 includes a first frame 332 and a second frame 333. The first frame 332 includes a first plate 3321 and a second plate 3322. The first plate 3321 and the second plate 3322 are connected and form an "L" shape in the cross-section of the frame 33. The second frame 333 is disposed on the surface of the first plate 3321 facing the cell 50 and on the side of the second plate 3322 facing the first plate 3321. The second frame 333 is connected to the end of the first plate 3321 away from the second plate 3322. The second frame 333 and the first plate 3321 enclose a snap-fit ​​groove 3311. The gap between the second frame 333 and the first plate 3321 and the second plate 3322 forms a connecting groove 3312. The gap between the second frame 333 and the second plate 3322 forms an opening of the connecting groove 3312.

[0063] Both the first frame 332 and the second frame 333 can be in the form of a ring connected end to end along the circumference of the frame 33, or one or both can be a multi-segment structure arranged sequentially along the circumference, without restriction.

[0064] The first plate 3321 protrudes from the side of the second plate 3322 facing the battery cell 50. The first plate 3321 and the second plate 3322 form an angle, the same as the angle between the direction of the aforementioned snap-fit ​​groove 3311 toward the connecting groove 3312 and the opening direction of the connecting groove 3312. In one embodiment, the angle between the first plate 3321 and the second plate 3322 is 90°. The first plate 3321 extends approximately along the Y direction, and the second plate 3322 extends approximately along the Z direction (at the connection between the frame 33 and the bottom plate 11 and the cover plate 21) or the X direction (at the connection between the frame 33 and the first side plate 12 and the second side plate 13). The first plate 3321 and the second plate 3322 form an "L" shape in the cross-section of the frame 33.

[0065] Taking the connection between the frame 33 and the cover plate 21 as an example, one of the first frame 332 and the second frame 333 can be recessed to form a snap-fit ​​groove 3311. Correspondingly, the flange 3422 of the edge portion 342 protrudes from one side surface of the body 3421 in the Z direction to correspond to the snap-fit ​​groove 3311. Alternatively, both the first frame 332 and the second frame 333 can be recessed to form the snap-fit ​​groove 3311. Correspondingly, the flange 3422 protrudes from both sides surface of the body 3421 in the Z direction to correspond to the snap-fit ​​groove 3311.

[0066] Optionally, the first frame 332 can be a one-piece structure, meaning the first plate 3321 and the second plate 3322 are manufactured using a single molding process. Alternatively, the first frame 332 can be a separate structure, with the first plate 3321 and the second plate 3322 formed as a whole through welding, screwing, snap-fitting, riveting, etc., without limitation. Optionally, the surfaces of the first plate 3321 and the second plate 3322 facing away from the second frame 333 are smoothly connected.

[0067] Optionally, the first frame 332 and the second frame 333 can be an integral structure, and their assembly with the elastic membrane 34 can be achieved by bending one of the first frame 332 and the second frame 333. Alternatively, the first frame 332 and the second frame 333 can be separate structures, with the second frame 333 and the end of the first plate 3321 away from the second plate 3322 forming an integral structure by welding, screwing, snapping, riveting, etc., without limitation.

[0068] Taking the connection between the frame 33 and the cover plate 21 as an example, referring to Figure 3, the second frame 333 and the first plate 3321 are spaced apart in the Z direction, and the second frame 333 and the second plate 3322 are also spaced apart in the Y direction. The two are connected and together form a connecting groove 3312 to accommodate the body 3421 of the elastic membrane 34.

[0069] By setting the first frame 332 to include the first plate 3321 and the second plate 3322, the second frame 333 and the first plate 3321 surround the snap-fit ​​groove 3311, and the gap between the second frame 333 and the first plate 3321 and the second plate 3322 forms a connecting groove 3312, the frame 33 and the elastic membrane 34 can be installed with a simple structure, and a stable support foundation can be provided for the elastic membrane 34.

[0070] In one embodiment, referring to FIG3, the second frame 333 includes a third plate 3331, a fourth plate 3332 and a fifth plate 3333 connected in sequence. The third plate 3331 is connected to the first plate 3321. The fourth plate 3332 is recessed in a direction away from the first plate 3321. The fifth plate 3333 is spaced from the second plate 3322. The fourth plate 3332 and the first plate 3321 together enclose the snap-fit ​​groove 3311. The fifth plate 3333, the first plate 3321 and the second plate 3322 together enclose the connecting groove 3312.

[0071] The second frame 333 can be a one-piece structure, meaning that the third plate 3331, the fourth plate 3332, and the fifth plate 3333 are a one-piece structure manufactured using a single molding process. Alternatively, two of the third plate 3331, the fourth plate 3332, and the fifth plate 3333 can be a one-piece structure, forming a whole with the third plate through welding, screwing, snap-fitting, etc. Or, the three plates can be independent and formed into a whole through welding, screwing, snap-fitting, riveting, etc., with no restrictions. When assembling with the elastic membrane 34, the flange 3422 can be placed into the snap-fit ​​groove 3311 enclosed by the fourth plate 3332 and the first plate 3321 firstly, and then the connection between the third plate 3331 and the first plate 3321 can be made.

[0072] The connection method between the third plate 3331 and the first plate 3321 can be welding, screwing, snap-fitting, riveting, etc., without restriction. The fifth plate 3333 and the first plate 3321 enclose the connection point of the connecting groove and the snap-fit ​​groove 3311, and the fifth plate 3333 and the second plate 3322 enclose the other part of the connecting groove and the opening of the connecting groove.

[0073] Optionally, the cross-sectional shape of the fourth plate 3332 can be trapezoidal, semi-circular, rectangular, etc., without any specific restrictions.

[0074] By setting the fourth plate 3332 of the second frame 333 to be recessed in a direction away from the first plate 3321 to form a snap-fit ​​groove 3311, the second frame 333 forms a convex bulge structure that protrudes towards the side of the battery cell 50, which can prevent the first frame 332, which is located outside the battery cell 50 relative to the second frame 333, from being lifted up by the air pressure change caused by the expansion of the battery cell 50.

[0075] In one embodiment, referring to FIG3, the second frame 333 protrudes from the end of the first plate 3321 away from the second plate 3322, and the portion of the second frame 333 protruding from the first plate 3321 is connected to the intermediate shell 10 and the cover plate 21.

[0076] In the Y direction, the second frame 333 protrudes from the end of the first plate 3321 away from the second plate 3322, that is, the end of the second frame 333 facing the cell 50 is closer to the cell 50 than the first frame 332. With this configuration, the second frame 333 has a mounting position exposed from the first frame 332 in a direction perpendicular to the Y direction. The intermediate shell 10 and the cover plate 21 can be connected and fixed to the second frame 333 at this mounting position. The connection method can be welding, screwing, snap-fitting, riveting, etc., without limitation.

[0077] Furthermore, the thickness of the connection between the intermediate shell 10 and the cover plate 21 and the second frame 333 is approximately the same as the thickness of the first plate 3321. The thickness of the first side plate 12 and the second side plate 13 of the intermediate shell 10 is its dimension in the X direction, and the thickness of the bottom plate 11 and the cover plate 21 of the intermediate shell 10 is its dimension in the Z direction.

[0078] This design allows the entire outer surface of the energy storage device 100 to have a roughly uniform structure, and the connection between the frame 33 and the intermediate shell 10 and the cover plate 21 is relatively flat, making it less likely to collide with other parts and also more aesthetically pleasing.

[0079] In another embodiment, referring to FIG4, the frame 33 includes a third frame 334 and a fourth frame 335. The third frame 334 is closer to the intermediate shell 10 than the fourth frame 335. The third frame 334 is connected to the intermediate shell 10 and the cover plate 21. The third frame 334 and the fourth frame 335 are connected and together enclose the mounting groove 331. The direction of the snap-fit ​​groove 3311 toward the connecting groove 3312 is on the same straight line as the opening direction of the connecting groove 3312.

[0080] Both the third frame 334 and the fourth frame 335 can be in the form of a ring connected end to end along the circumference of the frame 33, or one or both can be a multi-segment structure arranged sequentially along the circumference, without limitation. In the cross-section at any position of the frame 33, the third frame 334 and the fourth frame 335 roughly form a "C" shape, and together they enclose the mounting groove 331.

[0081] Alternatively, one of the third frame 334 and the fourth frame 335 may be recessed to form the snap-fit ​​groove 3311. Correspondingly, the flange 3422 of the elastic membrane 34 protrudes from one side surface of the body 3421 in the Y direction to correspond to the snap-fit ​​groove 3311. Or both the third frame 334 and the fourth frame 335 may be recessed to form the snap-fit ​​groove 3311. Correspondingly, the flange 3422 protrudes from both sides surface of the body 3421 in the Y direction to correspond to the snap-fit ​​groove 3311.

[0082] Optionally, the third frame 334 and the fourth frame 335 can be an integral structure, and the assembly of their overall "C"-shaped structure with the elastic membrane 34 can be achieved by bending one of the third frame 334 and the fourth frame 335. Specifically, an intermediate component is first fabricated, which has an "L"-shaped cross-section at any position, and the surface near the junction of the two segments of the "L"-shaped structure is pre-formed with a recess. Then, the flange 3422 of the elastic membrane 34 is placed into one of the recesses. After that, one of the two segments of the "L"-shaped structure is bent to form a "C"-shaped structure, and the pre-formed recesses face each other to form a snap-fit ​​groove 3311.

[0083] Optionally, the third frame 334 and the fourth frame 335 can also be a separate structure. The end of the third frame 334 away from the battery cell 50 is connected and fixed to the fourth frame 335. The end of the third frame 334 facing the battery cell 50 and the end of the fourth frame 335 facing the battery cell 50 are spaced apart to form a connecting groove 3312.

[0084] The opening end of the third frame 334 away from the connecting groove 3312 can be flush with the fourth frame 335, or the opening end of the third frame 334 away from the connecting groove 3312 can protrude from the fourth frame 335, or the fourth frame 335 can protrude from the opening end of the third frame 334 away from the connecting groove 3312. All of the above methods are acceptable and there is no specific restriction.

[0085] Optionally, the intermediate shell 10 and the cover plate 21 can be connected and fixed to the third frame 334 on the side of the third frame 334 facing away from the fourth frame 335. The connection method can be welding, screwing, snap-fitting, riveting, etc., without limitation.

[0086] By setting the frame 33 to include a third frame 334 and a fourth frame 335, the third frame 334 and the fourth frame 335 are opposite to each other and connected to form an installation groove 331. The connecting groove 3312 of the installation groove 331 is roughly a straight structure. The simple structure can realize the installation of the frame 33 and the elastic membrane 34 and provide a stable support foundation for the elastic membrane 34. The structure is simple.

[0087] In one embodiment, referring to FIG4, the opening end of the third frame 334 away from the connecting groove 3312 protrudes out of the fourth frame 335.

[0088] Optionally, the connection method between the third frame 334 and the fourth frame 335 can be welding, screwing, riveting, etc., without limitation. For example, the opening end of the third frame 334 away from the connecting groove 3312 is welded and fixed to the fourth frame 335, and the opening end of the third frame 334 away from the connecting groove 3312 protrudes from the fourth frame 335, thereby providing a welding position, which facilitates welding operations, and the molten metal after welding will not flow into the mounting groove 331, avoiding the high temperature from affecting the elastic membrane 34.

[0089] By setting the opening of the third frame 334 away from the connecting groove 3312 to protrude from the fourth frame 335, it is convenient to connect and assemble the third frame 334 and the fourth frame 335.

[0090] In one embodiment, referring to FIG4, a step 3341 is provided at the end face of the opening of the third frame 334 away from the connecting groove 3312 and the surface of the third frame 334 away from the fourth frame 335. The intermediate shell 10 and the cover plate 21 are connected to the step 3341.

[0091] Step 3341 includes step surface 3342, which is a plane recessed from the surface of the third frame 334 facing away from the fourth frame 335. Step surface 3342 is connected to the end face of the third frame 334 away from the opening of the connecting groove 3312. Step surface 3342 may be approximately parallel to the surface of the third frame 334 facing away from the fourth frame 335, or it may have a certain angle, without limitation. The sidewall of step 3341 connects step surface 3342 and the surface of the third frame 334 facing away from the fourth frame 335.

[0092] With this configuration, the intermediate shell 10, cover plate 21 are connected to the step 3341, specifically to the step surface 3342. The side wall of the step 3341 can position and limit the intermediate shell 10 and cover plate 21. The surfaces of the intermediate shell 10 and cover plate 21 away from the cell 50 can be roughly flush with the end face of the third frame 334 away from the opening of the connecting groove 3312. The outer surface of the entire energy storage device 100 is relatively complete and uniform.

[0093] Optionally, the step 3341 can be connected to the intermediate shell 10 and the cover plate 21 by welding, screwing, riveting, etc., without limitation. For example, the step 3341 is welded to the intermediate shell 10 and the cover plate 21. The step 3341 provides a welding position, which facilitates welding operations, and the molten metal after welding will not flow into the mounting groove 331, thus avoiding the high temperature from affecting the elastic membrane 34.

[0094] By setting a step 3341 at the junction of the end face of the third frame 334 away from the opening of the connecting groove 3312 and the surface of the third frame 334 away from the fourth frame 335, it is convenient for the third frame 334 to be connected and assembled with the intermediate shell 10 and the cover plate 21 at the step 3341, and the outer surface of the entire energy storage device 100 is relatively complete and uniform after assembly.

[0095] In another embodiment, referring to FIG5, in the cross-section of the frame 33, the frame 33 is S-shaped and includes a fifth frame 351, a first connecting frame 352, a sixth frame 353, a second connecting frame 354, and a seventh frame 355 connected in sequence. The fifth frame 351 is opposite to the sixth frame 353. The first connecting frame 352 connects the fifth frame 351 and the sixth frame 353. The fifth frame 351, the first connecting frame 352, and the sixth frame 353 together enclose the mounting groove 331. The direction of the snap-fit ​​groove 3311 toward the connecting groove 3312 is on the same straight line as the opening direction of the connecting groove 3312. The second connecting frame 354 is connected to the end of the sixth frame 353 away from the first connecting frame 352. The seventh frame 355 is disposed on the side of the sixth frame 353 away from the fifth frame 351. The seventh frame 355 is connected to the second connecting frame 354 and is connected to the intermediate shell 10 and the cover plate 21.

[0096] Optionally, the fifth frame 351, the first connecting frame 352, the sixth frame 353, the second connecting frame 354, and the seventh frame 355 can be integral structures manufactured using a one-piece molding process. Alternatively, any two or more of the fifth frame 351, the first connecting frame 352, the sixth frame 353, the second connecting frame 354, and the seventh frame 355 can be integral structures, forming a whole with the remaining parts through welding, screwing, snap-fitting, etc., or the five components can be independent and formed into a whole through welding, screwing, snap-fitting, etc., without restriction.

[0097] The fifth frame 351, the first connecting frame 352, the sixth frame 353, the second connecting frame 354, and the seventh frame 355 can all be in the form of a ring connected end to end along the circumference of the frame 33, or one or more of them can be a multi-segment structure arranged sequentially along the circumference, without limitation. In the cross-section at any position of the frame 33, the fifth frame 351, the sixth frame 353, and the first connecting frame 352 roughly form a "C" shape structure, and the three together enclose the mounting groove 331. The direction of the snap-fit ​​groove 3311 toward the connecting groove 3312 is on the same straight line as the opening direction of the connecting groove 3312, and the opening of the snap-fit ​​groove 3311 faces the battery cell 50.

[0098] Alternatively, one of the fifth frame 351 and the sixth frame 353 may be recessed to form the snap-fit ​​groove 3311. Correspondingly, the flange 3422 of the elastic membrane 34 protrudes from one side surface of the body 3421 in the Y direction to correspond to the snap-fit ​​groove 3311. Or both the fifth frame 351 and the sixth frame 353 may be recessed to form the snap-fit ​​groove 3311. Correspondingly, the flange 3422 protrudes from both sides surface of the body 3421 in the Y direction to correspond to the snap-fit ​​groove 3311.

[0099] In a cross-section at any location on the frame 33, the sixth frame 353, the second connecting frame 354, and the seventh frame 355 also roughly form a "C" shape, and the opening direction of this "C" shape is opposite to that of the "C" shape roughly formed by the fifth frame 351, the sixth frame 353, and the first connecting frame 352. In a cross-section at any location on the frame 33, the fifth frame 351, the first connecting frame 352, the sixth frame 353, the second connecting frame 354, and the seventh frame 355 as a whole roughly form an "S" shape.

[0100] The “S” shaped structure of the frame 33 can also be achieved by bending. During the bending process, the flange 3422 of the elastic membrane 34 is first placed into the recess of the fifth frame 351 and the sixth frame 353, and then the fifth frame 351 is bent relative to the sixth frame 353, so that the installation of the elastic membrane 34 can be achieved.

[0101] Optionally, the surfaces of the seventh frame 355 and the sixth frame 353 facing away from the fifth frame 351 may be in contact, or there may be a gap between the surfaces of the seventh frame 355 and the sixth frame 353 facing away from the fifth frame 351. Any of the above methods are acceptable and there is no specific limitation.

[0102] Optionally, there is a gap between the surfaces of the seventh frame 355 and the sixth frame 353 facing away from the fifth frame 351. The size of this gap in the Y direction is 0mm-0.05mm, specifically 0.01mm, 0.015mm, 0.02mm, 0.025mm, 0.03mm, 0.035mm, 0.04mm, 0.045mm, 0.05mm, etc., and there is no specific limitation. In one specific embodiment, the size of this gap in the Y direction is 0.05mm.

[0103] By setting the frame 33 to include a fifth frame 351, a first connecting frame 352, a sixth frame 353, a second connecting frame 354, and a seventh frame 355 connected in sequence, the fifth frame 351, the first connecting frame 352, and the sixth frame 353 together enclose the mounting groove 331, and the seventh frame 355 is connected to the intermediate shell 10 and the cover plate 21, it is also possible to install the elastic membrane 34 on the frame 33 while connecting the frame 33 to the intermediate shell 10 and the cover plate 21, which is a simple structure.

[0104] In one embodiment, referring to FIG5, the fifth frame 351, the first connecting frame 352 and the sixth frame 353 are all located in the first space 40, and the seventh frame 355 protrudes from the side of the first connecting frame 352 facing away from the second connecting frame 354. The part of the seventh frame 355 protruding from the first connecting frame 352 is connected to the intermediate shell 10 and the cover plate 21.

[0105] Optionally, the connection method between the seventh frame 355 and the intermediate shell 10 and the cover plate 21 can be welding, screwing, riveting, etc., without limitation. For example, the seventh frame 355 is welded and fixed to the intermediate shell 10 and the cover plate 21. The seventh frame 355 protrudes from the side of the first connecting frame 352 facing away from the second connecting frame 354, thereby providing a welding position and facilitating welding operations.

[0106] By setting the seventh frame 355 to protrude from the side of the first connecting frame 352 facing away from the second connecting frame 354, it is convenient for the frame 33 to be connected to the intermediate shell 10 and the cover plate 21.

[0107] In one embodiment, referring to FIG5, the first connecting frame 352 includes a first outer surface 3521 facing away from the fifth frame 351 and the sixth frame 353, and the first outer surface 3521 is an arc surface.

[0108] Optionally, the first outer surface 3521 is smoothly connected to the surface of the fifth frame 351 facing away from the sixth frame 353 and the surface of the sixth frame 353 facing the seventh frame 355.

[0109] The first outer surface 3521 is a convex surface. In the cross-section of the frame 33, the outline of the first outer surface 3521 is an arc. The first outer surface 3521 is tangent to the surface of the fifth frame 351 facing away from the sixth frame 353. The first outer surface 3521 is also tangent to the surface of the sixth frame 353 facing the seventh frame 355.

[0110] During installation, the frame 33 is moved relative to the intermediate shell 10 and the cover plate 21. The intermediate shell 10 and the cover plate 21 can first contact the first outer surface 3521. Since the first outer surface 3521 is an arc surface, the intermediate shell 10 and the cover plate 21 will slide along the first outer surface 3521 and contact the surface of the mounting frame facing the storage space to complete accurate positioning. Then, the seventh frame 355 is connected to the intermediate shell 10 and the cover plate 21, for example, by welding.

[0111] By setting the first outer surface 3521 as an arc surface, when the intermediate shell 10 and cover plate 21 are connected to the seventh frame 355, the first outer surface 3521 can guide the intermediate shell 10 and cover plate 21 to ensure accurate positioning.

[0112] In another embodiment, referring to FIG6, the intermediate shell 10 includes a main shell 15 and a side shell 16, the side shell 16 being connected to the edge of the main shell 15 and the side shell 16 being bent relative to the main shell 15 toward the first space 40.

[0113] The intermediate shell 10 can be a one-piece structure, meaning the main shell 15 and the side shell 16 are manufactured using a single molding process. For example, the intermediate shell 10 can be formed by bending a long plate, or it can be formed using other processes; there are no restrictions. The intermediate shell 10 can also be a separate structure, with the main shell 15 and the side shell 16 connected and fixed by welding, screwing, riveting, or other methods. The frame protrudes from the surface of the main shell 15 facing the first space 40.

[0114] The surface of the side shell 16 facing the first space 40 can be a plane, a curved surface, etc., without limitation. Optionally, the surface of the side shell 16 facing the first space 40 can be a plane, and the surface of the side shell 16 facing the first space 40 has an angle with the surface of the main shell 15 facing the first space 40. The angle can be 90°-130°, specifically 90°, 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, etc., without limitation.

[0115] The side shell 16 includes a connecting surface 161 facing away from the first space 40, the frame 33 is connected to the connecting surface 161, and the frame 33 and the side shell 16 together enclose the mounting groove 331.

[0116] The connection method between the frame 33 and the connecting surface 161 can be welding, snap-fitting, screwing, riveting, etc., and there is no specific limitation. The frame 33 and the connecting surface 161 together enclose to form the mounting groove 331, and receive at least part of the flange 3422 and the body 3421.

[0117] By setting the intermediate shell 10 to include a side shell 16 that bends relative to the main shell 15 toward the first space 40, and the connecting surface 161 of the side shell 16 facing away from the first space 40 together with the frame 33 to enclose the mounting groove 331, the frame 33 can be installed with the elastic membrane 34 while the frame 33 is connected to the intermediate shell 10, resulting in a simple structure.

[0118] Similarly, the cover plate 21 and the base plate 11 may also include a main plate and an edge plate, with the edge plate connected to the edge of the main plate and bent relative to the main plate toward the first space 40. The surface of the edge plate facing away from the first space 40 is connected to the frame 33 and together encloses the mounting groove 331, which will not be described in detail here.

[0119] In one embodiment, referring to FIG6, the frame 33 includes an eighth frame 361 and a ninth frame 362. The eighth frame 361 and the ninth frame 362 are connected and form an "L" shape. The end of the eighth frame 361 away from the ninth frame 362 is connected to the connecting surface 161. The area of ​​the ninth frame 362 near the eighth frame 361 is recessed to form a snap-fit ​​groove 3311 together with the connecting surface 161. The area of ​​the ninth frame 362 away from the eighth frame 361 has a gap with the side shell 16 to form a connecting groove 3312.

[0120] Both the eighth frame 361 and the ninth frame 362 can be in the form of a ring connected end to end along the circumference of the frame 33, or one or both can be a multi-segment structure arranged sequentially along the circumference, without limitation. The ninth frame 362 protrudes from the surface of the eighth frame 361 facing the mounting groove 331, and in the cross-section at any position of the frame 33, the eighth frame 361 and the ninth frame 362 roughly form an "L" shape, which together with the connecting surface 161 enclose the mounting groove 331.

[0121] The eighth frame 361 and the ninth frame 362 can be a single-piece structure. For example, they can be formed by bending a long plate to form the frame 33, or they can be formed using other processes. There are no restrictions. The eighth frame 361 and the ninth frame 362 can also be connected and fixed by welding, screwing, riveting, etc. There are no restrictions.

[0122] In the Y direction, the distance from the bottom wall of the snap-fit ​​groove 3311 to the connecting surface 161 is greater than the distance between the two side walls of the connecting groove 3312 in the Y direction. With this configuration, after the flange 3422 is inserted into the snap-fit ​​groove 3311, the elastic membrane 34 pulls the flange 3422 when it deforms. The flange 3422 will snap against the side wall of the connecting groove 3312 facing the opening of the snap-fit ​​groove 3311 without exiting through the connecting groove 3312, thus realizing the snap-fit ​​connection between the elastic membrane 34 and the frame 33.

[0123] The end of the eighth frame 361 furthest from the ninth frame 362 can be connected to the connecting surface 161 by welding, bonding, snap-fitting, screwing, riveting, etc., to achieve the connection between the frame 33 and the intermediate shell 10. When assembling with the elastic membrane 34, the flange 3422 can be placed into the snap-fit ​​groove 3311 formed by the ninth frame 362 and the connecting surface 161 first, and then the eighth frame 361 and the connecting surface 161 can be connected.

[0124] Optionally, as shown in Figure 6, the portion of the ninth frame 362 corresponding to the snap-fit ​​groove 3311 protrudes away from the eighth frame 361. When the portion of the ninth frame 362 corresponding to the snap-fit ​​groove 3311 protrudes away from the eighth frame 361, the thickness of the portion of the ninth frame 362 corresponding to the snap-fit ​​groove 3311 (i.e., the dimension of this portion in the Y direction) can be approximately the same as the thickness of the portion of the ninth frame 362 corresponding to the connecting groove 3312 (i.e., the dimension of this portion in the Y direction). With this setting, the overall thickness of the ninth frame 362 is approximately the same, resulting in better structural strength.

[0125] In other embodiments, the portion of the ninth frame 362 corresponding to the snap-fit ​​groove 3311 does not protrude in the direction away from the eighth frame 361. In other words, the ninth frame 362 is generally flat, and the surface of the ninth frame 362 facing the eighth frame 361 is recessed in the area of ​​the ninth frame 362 near the eighth frame 361 to form the snap-fit ​​groove 3311.

[0126] By setting the frame 33 to include an eighth frame 361 and a ninth frame 362, and forming an installation groove 331 between the eighth frame 361, the ninth frame 362 and the connecting surface 161, the simple structure can realize the installation with the elastic membrane 34 and provide a stable support foundation for the elastic membrane 34. The structure is simple.

[0127] In one embodiment, referring to FIG6, the end face of the side shell 16 away from the main shell 15 is smoothly connected to the connecting surface 161, and the area of ​​the smooth connection has a gap with the ninth shell to form a communicating groove 3312.

[0128] Optionally, the smoothly connected region is tangent to both the end face of the side shell 16 away from the main shell 15 and the connecting surface 161. The smoothly connected region protrudes toward the ninth shell, and there is a gap between the smoothly connected region and the ninth shell to form a communicating groove 3312 to accommodate at least a portion of the body 3421.

[0129] After installation, the body 3421 of the elastic membrane 34 will contact the end face of the side shell 16 away from the main shell 15. By setting the end face of the side shell 16 away from the main shell 15 to be smoothly connected with the connecting surface 161, the end face of the side shell 16 away from the main shell 15 can be prevented from damaging the body 3421 of the elastic membrane 34, thereby improving the service life of the elastic membrane 34.

[0130] In one embodiment, the frame 33 has rounded corners at the position where the main body 341 and the edge 342 meet.

[0131] In one specific embodiment, as shown in FIG3, the end of the second plate 3322 away from the first plate 3321 is rounded. In another specific embodiment, as shown in FIG4, the end of the fourth frame 335 away from the intermediate shell 10 or the cover plate 21 is smoothly connected to the side of the fourth frame 335 facing the third frame 334. In yet another specific embodiment, as shown in FIG5, the second connecting frame 354 includes a second outer surface 3541 facing away from the sixth frame 353 and the seventh frame 355, and the second outer surface 3541 is an arc surface. In yet another specific embodiment, as shown in FIG6, the end of the ninth frame 362 away from the eighth frame 361 is smoothly connected to the surface of the ninth frame 362 facing the side shell 16.

[0132] By rounding the corners at the junction of the frame 33 with the main body 341 and the edge 342, the sharp corners at the junction can be prevented from contacting the elastic membrane 34 and causing a shearing effect, thereby improving the service life of the elastic membrane 34.

[0133] In one embodiment, referring to FIG2, the inner wall surface of the intermediate shell 10 is provided with a plurality of protrusions 14 spaced apart.

[0134] The shape and size of the protrusions 14 are not limited; they can be block-shaped, column-shaped, etc. Multiple protrusions 14 can be arranged at equal intervals, or the interval between two adjacent protrusions 14 is not limited. In one embodiment, multiple protrusions 14 are arranged in an array.

[0135] Multiple protrusions 14 can be provided on any one or a combination of multiple protrusions 14 on the base plate 11, the first side plate 12, and the second side plate 13. For example, in one embodiment, as shown in FIG2, multiple protrusions 14 are provided on the base plate 11, the first side plate 12, and the second side plate 13. Alternatively, multiple protrusions 14 are provided on the first side plate 12 and the second side plate 13, and no protrusions 14 are provided on the base plate 11. Alternatively, multiple protrusions 14 are all provided on the base plate 11. All of the above methods are acceptable and there is no specific limitation.

[0136] The protrusion 14 and the intermediate shell 10 can be an integral structure, or the protrusion 14 can be connected and fixed to the inner wall of the intermediate shell 10 by welding, screwing, riveting or other processes. There are no specific restrictions.

[0137] By setting multiple protrusions 14 spaced apart on the inner wall of the intermediate shell 10, the battery cell 50 in the storage space can be positioned and limited to prevent the battery cell 50 from moving randomly in the X and Z directions, ensuring that the relative position of the battery cell 50 and the elastic membrane 34 is accurate, thereby making the elastic membrane 34 and the large surface of the battery cell 50 elastically abut against each other.

[0138] In one embodiment, the end cap assembly 20 further includes a one-way valve (not shown) disposed on the cover plate 21, the one-way valve being used to release pressure when the internal pressure of the energy storage device 100 reaches a threshold.

[0139] Optionally, the cover plate 21 has a vent hole (not shown), and a one-way valve is disposed at the vent hole. The connection method between the one-way valve and the cover plate 21 can be welding, bonding, snap-fitting, screwing, etc., and there is no specific limitation. The specific structure of the one-way valve can refer to any feasible solution, and the embodiments of this application are not limited.

[0140] The one-way valve only allows excess gas inside the energy storage device 100 to escape, while preventing external gas from entering the energy storage device 100. This allows for timely pressure release when the internal pressure of the energy storage device 100 becomes too high, ensuring the safety of the energy storage device 100.

[0141] This application embodiment also provides an energy storage device, including the energy storage device 100 in this application embodiment and a reinforcing plate, wherein the reinforcing plate is disposed on at least one side in the thickness direction of the energy storage device 100.

[0142] Optionally, the energy storage device also includes a housing with a receiving space in which the energy storage device 100 is housed.

[0143] The enclosure is made of a material with high structural strength, specifically metal, high-strength plastic, ceramic, etc. Metal materials include aluminum, aluminum alloys, magnesium alloys, iron, and iron alloys. The enclosure can be a one-piece structure, meaning it is manufactured using a single molding process, such as stamping or casting, with no restrictions. Alternatively, the enclosure can be a modular structure, with each part connected and secured using welding, bonding, snap-fitting, screwing, or other methods.

[0144] In one embodiment, the enclosure of the energy storage device is generally cuboid. The enclosure includes a bottom wall and four connecting plates, which are connected to the bottom wall and enclose a receiving space. The four connecting plates include a first connecting plate and a second connecting plate opposite each other in the Y direction. A reinforcing plate is received within the receiving space and disposed between the energy storage device 100 and the first connecting plate, and / or, the reinforcing plate is disposed between the energy storage device 100 and the second connecting plate; the specific placement is not limited.

[0145] The energy storage device in this application embodiment provides an additional preload force on the cell 50 in the thickness direction (i.e., the Y direction) of the cell 50 by providing a reinforcing plate on at least one side in the Y direction, in addition to the preload force provided by the elastic membrane 34, thereby meeting the working requirements of the energy storage device 100.

[0146] In one embodiment, there are multiple energy storage devices 100, which are arranged sequentially along the Y direction; a reinforcing plate is provided on the outermost side of the multiple energy storage devices 100 in the Y direction, and / or a reinforcing plate is provided between two adjacent energy storage devices 100.

[0147] Optionally, the reinforcing plate is disposed between the energy storage device 100 closest to the first connecting plate and the first connecting plate among the multiple energy storage devices 100 in the Y direction, and / or, the reinforcing plate is disposed between the energy storage device 100 closest to the second connecting plate and the second connecting plate among the multiple energy storage devices 100 in the Y direction. The reinforcing plate can also be disposed between any two adjacent energy storage devices 100. Reinforcing plates can be disposed between both adjacent energy storage devices 100, or, in the multiple energy storage devices 100 arranged sequentially along the Y direction, a reinforcing plate can be disposed every two energy storage devices 100. Other arrangements of the reinforcing plate are also possible, and there are no specific limitations.

[0148] For example, reinforcing plates are provided between the energy storage device 100 closest to the first connecting plate and the first connecting plate, between the energy storage device 100 closest to the second connecting plate and the second connecting plate, and between two adjacent energy storage devices 100.

[0149] Optionally, the reinforcing plate can be connected and fixed to the housing / energy storage device 100, or the reinforcing plate can be movable in the Y direction, without any specific limitation.

[0150] At least one reinforcing plate is movable in the Y direction. Optionally, there is one reinforcing plate, which is located on the outermost side of the energy storage device in the Y direction. The reinforcing plate can move in the Y direction to clamp the energy storage device and prevent it from expanding excessively. Alternatively, there are two reinforcing plates, which are respectively located on the outermost sides of the energy storage device in the Y direction. One reinforcing plate is fixedly connected to the housing, and the other reinforcing plate can move relative to it. Alternatively, there are multiple reinforcing plates. Reinforcing plates are provided between the energy storage device 100 closest to the second connecting plate and the second connecting plate, as well as between two adjacent energy storage devices 100. One reinforcing plate located on the outermost side of the energy storage device in the Y direction is fixedly connected to the housing, and the remaining reinforcing plates can move relative to it. The above methods and any other feasible methods are acceptable and are not limited in specific terms.

[0151] With this configuration, by setting up a movable reinforcing plate that can move toward or away from the energy storage device 100, the pressure on the battery cell can be further increased, preventing the battery cell from over-expanding and deteriorating.

[0152] By providing a reinforcing plate on the outermost side of the overall thickness direction of the multiple energy storage devices 100, and / or by providing a reinforcing plate between two adjacent energy storage devices 100, the reinforcing plate can provide additional pre-tightening force to the battery cell 50 in addition to the pre-tightening force provided by the elastic membrane 34, thereby meeting the working requirements of the energy storage device 100.

[0153] This application also provides a power system, including electrical equipment and an energy storage device 100 as described in this application embodiment, or an energy storage device 100 or energy storage device as described in this application embodiment, wherein the energy storage device 100 or energy storage device supplies power to the electrical equipment.

[0154] The power system can be used for electric vehicles, hybrid electric vehicles, base stations, household electrical loads, etc., without specific restrictions.

[0155] The power system in this application embodiment employs the energy storage device 100 or energy storage equipment in this application embodiment. The energy storage device 100 or energy storage equipment can provide sufficient preload to the battery cell 50, which can meet the working requirements of the energy storage device 100 or energy storage equipment.

[0156] In the description of the embodiments of this application, it should be noted that the orientation or positional relationship of the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and other indicators are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0157] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art will understand that all or part of the processes for implementing the above embodiments and equivalent variations made in accordance with the claims of this application are still within the scope of this application.

Claims

1. An energy storage device (100), wherein, include: The intermediate shell (10) includes a bottom plate (11), a first side plate (12) and a second side plate (13). The first side plate (12) and the second side plate (13) are connected to the bottom plate (11), and the first side plate (12) and the second side plate (13) are both located on the same side of the bottom plate (11). The first side plate (12) and the second side plate (13) are arranged at intervals relative to each other. End cap assembly (20) includes a cover plate (21) connected to the first side plate (12) and the second side plate (13) and opposite to the bottom plate (11), the intermediate shell (10) and the cover plate (21) enclosing a first space (40); The first side shell (31) and the second side shell (32) are all connected to the bottom plate (11), the first side plate (12), the second side plate (13) and the cover plate (21), and the first side shell (31) and the second side shell (32) are arranged at intervals relative to each other; At least one of the first side shell (31) and the second side shell (32) includes a frame (33) and an elastic membrane (34). The frame (33) is annular and connected end to end. The frame (33) is connected to the bottom plate (11), the first side plate (12), the second side plate (13), and the cover plate (21). The elastic membrane (34) includes a main body (341) and an edge (342). The edge (342) is connected to the four periphery of the main body (341). Along; the frame (33) has a mounting groove (331), the opening of the mounting groove (331) facing the first space (40), the edge portion (342) extends into the mounting groove (331) and is connected to the frame (33), the main body portion (341) protrudes relative to the frame (33) in a direction away from the intermediate shell (10); the main body portion (341) encloses a second space (3411), the second space (3411) and the first space (40) are connected, The battery cell (50) is housed in the first space (40) and the second space (3411). In the cross-section along the height direction of the energy storage device (100), the battery cell (50) is a racetrack-shaped wound battery cell or a rectangular stacked battery cell. The direction opposite to the first side shell (31) and the second side shell (32) is the thickness direction of the battery cell (50). The elastic membrane (34) elastically abuts against the large surface of the battery cell (50).

2. The energy storage device (100) according to claim 1, wherein, The minimum distance between the first side shell (31) and the second side shell (32) is less than the thickness of the battery cell (50).

3. The energy storage device (100) according to claim 2, wherein, The mounting groove (331) includes a snap-fit ​​groove (3311) and a connecting groove (3312). The opening of the connecting groove (3312) connects the junction of the first space (40) and the second space (3411). The other end of the connecting groove (3312) connects to the snap-fit ​​groove (3311). The spacing between the two opposite inner wall surfaces of the snap-fit ​​groove (3311) is greater than the spacing between the two opposite inner wall surfaces of the connecting groove (3312). The edge portion (342) includes a body (3421) and a flange (3422). The body (3421) is annular and its inner four peripheral edges are connected to the main body portion (341). The flange (3422) is connected to the outer four peripheral edges of the body (3421). The thickness of the flange (3422) is greater than the thickness of the body (3421). The flange (3422) is received in the snap-fit ​​groove (3311). At least a portion of the body (3421) is received in the connecting groove (3312).

4. The energy storage device (100) according to claim 3, wherein, The direction of the snap-fit ​​groove (3311) toward the connecting groove (3312) is at an angle to the opening direction of the connecting groove (3312). In the cross-section of the elastic membrane (34), the body (3421) is bent and there is an angle between the body (3421) and the main body (341).

5. The energy storage device (100) according to claim 4, wherein, The frame (33) includes a first frame (332) and a second frame (333). The first frame (332) includes a first plate (3321) and a second plate (3322). The first plate (3321) and the second plate (3322) are connected and form an "L" shape in the cross-section of the frame (33). The second frame (333) is disposed on the surface of the first plate (3321) facing the battery cell (50) and on the side of the second plate (3322) facing the first plate (3321). The second frame (333) is connected to the end of the first plate (3321) away from the second plate (3322). The second frame (333) and the first plate (3321) enclose the snap-fit ​​groove (3311). The gap between the second frame (333) and the first plate (3321) and the second plate (3322) forms the communicating groove (3312). The gap between the second frame (333) and the second plate (3322) forms the opening of the communicating groove (3312).

6. The energy storage device (100) according to claim 5, wherein, The second frame (333) includes a third plate (3331), a fourth plate (3332), and a fifth plate (3333) connected in sequence. The third plate (3331) is connected to the first plate (3321). The fourth plate (3332) is recessed away from the first plate (3321). The fifth plate (3333) is spaced from the second plate (3322). The fourth plate (3332) and the first plate (3321) together enclose the snap-fit ​​groove (3311). The fifth plate (3333), the first plate (3321), and the second plate (3322) together enclose the connecting groove (3312).

7. The energy storage device (100) according to claim 5, wherein, The second frame (333) protrudes from the end of the first plate (3321) away from the second plate (3322), and the portion of the second frame (333) protruding from the first plate (3321) is connected to the intermediate shell (10) and the cover plate (21).

8. The energy storage device (100) according to claim 3, wherein, The frame (33) includes a third frame (334) and a fourth frame (335). The third frame (334) is closer to the intermediate shell (10) than the fourth frame (335). The third frame (334) is connected to the intermediate shell (10) and the cover plate (21). The third frame (334) and the fourth frame (335) are connected and together enclose the mounting groove (331). The direction of the snap-fit ​​groove (3311) toward the connecting groove (3312) is on the same straight line as the opening direction of the connecting groove (3312).

9. The energy storage device (100) according to claim 8, wherein, The third frame (334) protrudes from the fourth frame (335) at the opening away from the connecting groove (3312).

10. The energy storage device (100) according to claim 8, wherein, A step is provided at the end face of the third frame (334) away from the opening of the connecting groove (3312) and the surface of the third frame (334) away from the fourth frame (335). The intermediate shell (10) and the cover plate (21) are connected to the step.

11. The energy storage device (100) according to claim 3, wherein, In the cross-section of the frame (33), the frame (33) is S-shaped and includes a fifth frame (351), a first connecting frame (352), a sixth frame (353), a second connecting frame (354), and a seventh frame (355) connected in sequence. The fifth frame (351) is opposite to the sixth frame (353), and the first connecting frame (352) connects the fifth frame (351) and the sixth frame (353). The fifth frame (351), the first connecting frame (352), and the sixth frame (353) together enclose the mounting groove (331). The direction of the snap-fit ​​groove (3311) toward the connecting groove (3312) is on the same straight line as the opening direction of the connecting groove (3312). The second connecting frame (354) is connected to the end of the sixth frame (353) away from the first connecting frame (352). The seventh frame (355) is disposed on the side of the sixth frame (353) facing away from the fifth frame (351). The seventh frame (355) is connected to the second connecting frame (354) and the seventh frame (355) is connected to the intermediate shell (10) and the cover plate (21).

12. The energy storage device (100) according to claim 11, wherein, The fifth frame (351), the first connecting frame (352) and the sixth frame (353) are all located in the first space (40). The seventh frame (355) protrudes from the side of the first connecting frame (352) facing away from the second connecting frame (354). The part of the seventh frame (355) protruding from the first connecting frame (352) is connected to the intermediate shell (10) and the cover plate (21).

13. The energy storage device (100) according to claim 12, wherein, The first connecting frame (352) includes a first outer surface (3521) facing away from the fifth frame (351) and the sixth frame (353), and the first outer surface (3521) is an arc surface.

14. The energy storage device (100) according to claim 3, wherein, The intermediate shell (10) includes a main shell (15) and a side shell (16). The side shell (16) is connected to the edge of the main shell (15) and is bent relative to the main shell (15) toward the first space (40). The side shell (16) includes a connecting surface (161) facing away from the first space (40). The frame (33) is connected to the connecting surface (161), and the frame (33) and the side shell (16) together enclose the mounting groove (331).

15. The energy storage device (100) according to claim 14, wherein, The frame (33) includes an eighth frame (361) and a ninth frame (362). The eighth frame (361) is connected to the ninth frame (362) and forms an "L" shape. The end of the eighth frame (361) away from the ninth frame (362) is connected to the connecting surface (161). The area of ​​the ninth frame (362) near the eighth frame (361) is recessed to form the snap-fit ​​groove (3311) together with the connecting surface (161). The area of ​​the ninth frame (362) away from the eighth frame (361) has a gap with the side shell (16) to form the connecting groove (3312).

16. The energy storage device (100) according to claim 15, wherein, The end face of the side shell (16) away from the main shell (15) is smoothly connected to the connecting surface (161), and the area of ​​the smooth connection has a gap with the ninth shell to form the communicating groove (3312).

17. The energy storage device (100) according to any one of claims 1 to 16, wherein, The frame (33) has rounded corners at the position where the main body (341) and the edge (342) meet.

18. The energy storage device (100) according to any one of claims 1 to 16, wherein, The inner wall of the intermediate shell (10) is provided with a plurality of protrusions (14) spaced apart.

19. The energy storage device (100) according to any one of claims 1 to 16, wherein, The end cap assembly (20) also includes a one-way valve disposed on the cover plate (21), which is used to release pressure when the internal pressure of the energy storage device (100) reaches a threshold.

20. An energy storage device, wherein, include: The energy storage device (100) as described in any one of claims 1 to 19; A reinforcing plate is disposed on at least one side of the energy storage device (100) in the thickness direction.

21. The energy storage device according to claim 20, wherein, The energy storage device (100) is a plurality of such devices, and the plurality of such energy storage devices (100) are arranged sequentially along the thickness direction; the reinforcing plate is provided on the outermost side of the plurality of such energy storage devices (100) in the thickness direction, and / or the reinforcing plate is provided between two adjacent energy storage devices (100); At least one of the reinforcing plates is movable in the thickness direction of the energy storage device (100).

22. An electric power system, wherein, include: Electrical equipment; The energy storage device (100) according to any one of claims 1 to 19 supplies power to the electrical equipment; or, The energy storage device as described in claim 20 or 21, wherein the energy storage device supplies power to the electrical equipment.

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