End cap assembly, energy storage device and residential energy storage system

Abstract

This application provides an end cap assembly, an energy storage device, and a residential energy storage system. The end cap assembly includes an end cap, a current collector, a vent membrane, and an explosion-proof valve. The end cap has a first mounting hole and an explosion-proof hole that penetrate the end cap along its thickness direction. The current collector includes a current collector body, a first connecting portion, and a second connecting portion. The current collector body includes a first surface and a second surface arranged opposite to each other, with the first surface facing the end cap. The first connecting portion is connected to the first surface and protrudes relative to the first surface. The first connecting portion is located in the central region of the current collector body, with a portion of the first connecting portion located within the first mounting hole. The second connecting portion is connected to the second surface and is recessed relative to the first surface and protrudes relative to the second surface. The second connecting portion extends radially along the center of the current collector body. The technical solution of this application enables the current collector to be electrically connected to the electrode assembly and the end cap without bending.

Description

Technical Field

[0001] This application relates to the field of energy storage devices, and more particularly to an end cap assembly, an energy storage device, and a residential energy storage system. Background Technology

[0002] A rechargeable battery, also known as a secondary battery or accumulator, is a battery that can be recharged after discharge to reactivate its active materials and continue to be used. The recyclable nature of rechargeable batteries has made them a primary power source for electrical devices. As the demand for rechargeable batteries increases, so do the performance requirements, especially for energy density per unit volume. The volume of the wound electrode assembly is a crucial parameter for improving this energy density. If the wound electrode assembly is too small, there is less active electrode material, resulting in wasted internal space and lower energy density. Conversely, if the wound electrode assembly is too large, it hinders electrolyte wetting, preventing some active materials from functioning effectively. Therefore, a balance must be struck between the volume of the wound electrode assembly and the effectiveness of electrolyte wetting when designing the battery structure.

[0003] To achieve high energy density per unit volume in secondary batteries, the wound cell is made as large as possible, with only a very small fit gap (typically ±0.25mm) between it and the cylindrical aluminum shell to allow for electrolyte wetting. Simultaneously, to improve the overall wetting effect on the end faces of the wound electrode assembly, an adapter end extends from one side of the positive current collector, creating a gap between the current collector body and the top cover. This gap is filled with electrolyte and wets the wound cell downwards. However, after welding the positive current collector body and the tab, this design requires bending the adapter end of the current collector to align the top cover and the wound cell and weld them to the cylindrical shell for sealing. Because the current collector is made of metal (usually aluminum), it has a certain yield strength. When bent, it may pull up the tab on the bent side and break it. To improve the welding strength on the bent side, the existing process adds a laser spot welding step to the welding groove on the bent side. However, the added laser spot welding step requires repositioning and moving the welding area, which has become one of the limiting factors for improving the production efficiency of secondary batteries. Summary of the Invention

[0004] Embodiments of this application provide an end cap assembly, an energy storage device, and a residential energy storage system, which can be electrically connected to the electrode assembly and the end cap without bending the current collector.

[0005] In a first aspect, this application provides an end cap assembly, comprising:

[0006] An end cap, the end cap having a first mounting hole and an explosion-proof hole, the first mounting hole and the explosion-proof hole penetrating the end cap along its thickness direction; and

[0007] A current collector includes a current collector body, a first connecting portion, and a second connecting portion. The current collector body includes a first surface and a second surface disposed opposite to each other. The first surface faces the end cap. The first connecting portion is connected to the first surface and protrudes relative to the first surface. The first connecting portion is located in the central region of the current collector body, and a portion of the first connecting portion is located in the first mounting hole. The second connecting portion is connected to the second surface and is recessed relative to the first surface and protrudes relative to the second surface. The second connecting portion extends along the radial direction of the center of the current collector body.

[0008] A breathable assembly is disposed between the manifold and the end cap. The breathable assembly includes a breathable membrane body, a first sealing ring, and a second sealing ring. The breathable membrane body includes a second mounting hole. The first sealing ring is connected to the outer periphery of the second mounting hole. The second sealing ring is connected to the outer periphery of the breathable membrane body and surrounds the first sealing ring. The thickness of the first sealing ring and the second sealing ring is greater than the thickness of the breathable membrane body. The thickness of both the first sealing ring and the second sealing ring is greater than the gap height between the manifold and the end cap.

[0009] An explosion-proof valve is connected to the explosion-proof port, and the projection of the explosion-proof port onto the venting component is located in the gap area between the first sealing ring and the second sealing ring.

[0010] Understandably, current collectors are typically multi-segment structures when fully fabricated. These segments are then bent to form a stacked structure, which can then be installed inside the housing. The opposite sides of the stacked structure along its thickness can be electrically connected to the end cap and the motor assembly, respectively. However, bending the current collector pushes the bent portion to its metal fatigue limit, making it highly susceptible to fracture at the bend, which can lead to the failure of the individual battery cell.

[0011] In this application, the first connecting part and the second connecting part are respectively located on opposite sides of the current collector body. This allows the first connecting part on one side of the current collector body to connect to the end cap, and the second connecting part on the other side of the current collector body to connect to the electrode assembly. As a result, both the first connecting part and the second connecting part are integrated on the current collector body. The current collector body can be electrically connected to the end cap and the electrode assembly and installed inside the casing of the single cell without bending. This effectively avoids the problem of single cell failure caused by the current collector breaking after bending.

[0012] Because the first and second sealing rings of the venting assembly seal the air chamber between the end cap and the current collector, the venting assembly ensures that after multiple cycles of use of the individual battery, the gas generated by the electrode assembly passes through and accumulates in the space below the end cap. This prevents gas from leaking out from the edge of the end cap or the first mounting hole of the end cap. When the pressure of the accumulated gas reaches a preset value, the gas can break through the explosion-proof valve on the end cap to release pressure, preventing the individual battery from exploding due to excessive internal pressure and improving the safety performance of the individual battery.

[0013] Furthermore, because the pores of the venting component allow gas to pass through while blocking water molecules, the electrolyte cannot pass through the venting component. This allows the second and first sealing rings to cooperate in enclosing a sealed gas chamber between the end cap and the current collector. Since the venting component allows gas generated by the electrode assembly to enter the gas chamber through the venting component, while blocking electrolyte from the side of the venting component away from the end cap from entering the gas chamber, the electrolyte can remain within the space where the electrode assembly is located. The electrolyte can continuously wet the electrode plates and provide ion channels, thus ensuring stable chemical reactions within the single cell. This improves the cycle life of the single cell. It effectively prevents electrolyte from the side of the venting component away from the end cap from flowing into the gas chamber, thus avoiding the problem of insufficient electrode wettability and the inability of the electrode assembly to carry out chemical reactions.

[0014] Furthermore, when the internal pressure of a single battery cell becomes too high and the explosion-proof valve is forced open, the gas inside the cell can escape from the gas chamber, thus depressurizing the cell. During this depressurization process, the venting component prevents the electrolyte from being flushed out with the venting airflow, avoiding electrolyte contamination of other structural components around the cell (such as other batteries). Simultaneously, it prevents toxic electrolyte from splashing and floating into the air, potentially poisoning humans or animals, further enhancing the safety performance of the single battery cell.

[0015] In one possible implementation, the first connecting portion includes a first column and a second column, the first column being connected to the first surface, the second column being connected to the end face of the first column facing away from the first surface, and the minimum radial dimension of the first column being greater than the maximum radial dimension of the second column.

[0016] The first column abuts against the surface of the end cap facing the collector, and the second column is mutually restrained by the wall of the first assembly hole.

[0017] Understandably, when the current collector is assembled with the end cap, the second pillar can be located within the first mounting hole of the end cap. The first pillar can be located within the gap between the end cap and the current collector body. The two ends of the first pillar along its height direction are connected to the current collector body and the end cap respectively. The first pillar can act as a spacer between the end cap and the current collector body, ensuring a constant distance between them. The gap between the end cap and the current collector body can form a gas chamber. This gas chamber can contain all or part of the gas when the pressure inside the single cell is too high. When the pressure inside the gas chamber exceeds a safe value, the gas can rupture the explosion-proof valve on the end cap to release pressure, thereby preventing the single cell from exploding.

[0018] In one possible implementation, the first connecting portion further includes a third column, which is connected to the end face of the second column opposite to the first column, and the third column is a cylinder;

[0019] The first assembly hole includes a first hole and a second hole arranged sequentially along the direction of the end cap toward the manifold. The first hole communicates with the second hole. The second column is mutually restrained by the hole wall of the second hole, and the third column is mutually restrained by the hole wall of the first hole.

[0020] It is understandable that the first connecting part can be mutually limited by the second column and the first column and the first assembly hole of the end cover, so that the current collector and the end cover can maintain their relative positions in the horizontal direction.

[0021] In one possible implementation, a plurality of vent holes are further included, which are spaced apart on the collection body. The plurality of vent holes are spaced apart from the first connecting portion and the second connecting portion, and each vent hole penetrates the collection body along the thickness direction of the collection body.

[0022] Understandably, the vent allows gas or liquid from a single battery cell to pass through. When the internal pressure of a single battery cell becomes too high, the gas and / or liquid inside the cell first pass through the vent, then force open the explosion-proof valve on the end cap to release pressure and prevent the single battery cell from exploding.

[0023] In one possible implementation, the current collector further includes a plurality of abutment plates connected to the outer periphery of the current collector body. The plurality of abutment plates are spaced apart circumferentially along the current collector body and are located in the gap area between the current collector body and the end cap. Each abutment plate is arranged at a right angle to the current collector body.

[0024] It is understandable that by placing the abutment plate in the gap area between the current collector and the end cap, two things are achieved. First, when the current collector is pushed towards the end cap by the electrode assembly (such as when a single cell falls), the abutment plate is driven to abut against the surface of the end cap facing the current collector, providing good cushioning and shock absorption, effectively preventing the current collector from deforming due to impact and ultimately causing the single cell to fail. Second, both the abutment plate and the first column of the first connecting part can act as spacers between the current collector and the end cap. Under the synergistic effect of the abutment plate and the first column, there is always a certain gap between the current collector and the end cap. The gap between the current collector and the end cap can form a gas chamber. The gas generated by the electrode assembly during operation can collect in the gas chamber. As the gas flows through the vent holes into the gas chamber, fragments moving with the gas (which may be electrode fragments or insulating film fragments) can be intercepted by the fence structure formed between the multiple vent holes of the current collector. This prevents fragments from moving into the gas chamber near the end cap, thus avoiding fragments from moving to the explosion-proof hole of the end cap and covering the explosion-proof valve, causing the explosion-proof valve to malfunction.

[0025] In one possible implementation, the ratio of the thickness of the first sealing ring and the second sealing ring to the gap height between the end cap and the manifold is between 1.5 and 1.1.

[0026] Understandably, when the ratio of the thickness of the first and second sealing rings to the gap between the end cap and the manifold is between 1.5 and 1.1, the first and second sealing rings can tightly abut against the end cap and the manifold on opposite sides in the thickness direction, thereby forming a sealed air chamber between the end cap and the manifold. Furthermore, the contact force between the first and second sealing rings and the end cap and the manifold will not be excessive, thus preventing excessive compression of the end cap and the manifold and ensuring structural integrity, preventing deformation.

[0027] In one possible implementation, the thickness of the first sealing ring and the second sealing ring is between 2 mm and 3.5 mm.

[0028] Understandably, when the thickness of the first and second sealing rings is between 2mm and 3.5mm, the first and second sealing rings can tightly abut against the end cap and the manifold, respectively, thereby forming a sealed air chamber between the end cap and the manifold. Furthermore, the contact force between the first and second sealing rings and the end cap and the manifold will not be excessive, thus preventing excessive compression of the end cap and the manifold and ensuring structural integrity, preventing deformation.

[0029] In one possible implementation, the distance between the inner wall of the first sealing ring and the peripheral side of the first connecting portion is between 1.5 mm and 3.5 mm.

[0030] Understandably, the gap between the first sealing ring and the peripheral side of the first connecting part can be used to accommodate the welding slag generated when welding the first connecting part of the current collector and the end cap, so as to prevent the welding slag from falling into the cell and causing an internal short circuit.

[0031] In one possible implementation, the breathable membrane body includes a first side and a second side disposed opposite to each other, the first side facing the end cap assembly and the second side facing the flow collector;

[0032] The first sealing ring and the second sealing ring are both protruding from the first surface and the second surface, respectively;

[0033] Alternatively, the first sealing ring and the second sealing ring protrude from the first surface, or the first sealing ring and the second sealing ring are flush with the second surface.

[0034] Understandably, if the first and second sealing rings are flush with each other on the second surface, the appearance of the breathable component can be made simpler.

[0035] In addition, if the breathable membrane body is located in the middle of the thickness direction of the first sealing ring and the second sealing ring, there can be a larger gap between the breathable membrane body and the second connecting part, which can prevent the weld marks from protruding from the surface of the current collector and scratching the breathable component after the second connecting part of the current collector is welded to the electrode assembly.

[0036] In one possible implementation, the breathable assembly further includes a first membrane flap and a second membrane flap, both of which are connected to the surface of the second sealing ring facing the end cap. The end of the first membrane flap facing away from the second sealing ring and the end of the second membrane flap facing away from the second sealing ring both abut against the end cap. The first membrane flap and the second membrane flap are spaced apart, with the first membrane flap surrounding the second membrane flap. In the direction from the breathable membrane body to the end cap, the distance between the first membrane flap and the second membrane flap gradually increases.

[0037] Understandably, by providing a first diaphragm flap and a second diaphragm flap between the second sealing ring and the end cap, the sealing performance between the second sealing ring and the end cap can be further improved. This prevents electrolyte from seeping into the gas chamber between the current collector and the end cap from the gap between the second sealing ring and the end cap.

[0038] In one possible implementation, the breathable component further includes a reinforcing rib located between the first sealing ring and the second sealing ring;

[0039] One end of the reinforcing rib is connected to the first sealing ring, and the reinforcing rib is arranged radially with the center of the breathable membrane body as the center, and the other end of the reinforcing rib is connected to the second sealing ring.

[0040] Understandably, reinforcing ribs can further enhance the mechanical strength of the ventilated components, preventing electrolyte from rupturing the ventilated components and causing the explosion-proof valve to be triggered accidentally when a single cell is accidentally dropped.

[0041] In one possible implementation, the breathable component further includes a reinforcing rib, which is annular and located between the first sealing ring and the second sealing ring, with the central axis of the reinforcing rib coinciding with the central axis of both the first and second sealing rings.

[0042] In one possible implementation, the breathable component further includes a metal mesh connected to the surface of the breathable membrane body facing the end cap.

[0043] Understandably, because the metal mesh is connected to the breathable membrane body, the metal mesh improves the overall structural strength of the breathable component, giving the breathable component stronger impact resistance.

[0044] Secondly, this application also provides an energy storage device, including an electrode assembly and the aforementioned end cap assembly, wherein the current collector is electrically connected to the electrode assembly on the side opposite to the end cap.

[0045] Thirdly, this application also provides a residential energy storage system, including an energy storage device with a load as described above, the energy storage device being used to supply power to the load. Attached Figure Description

[0046] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments 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.

[0047] Figure 1 This is a residential energy storage system provided in the embodiments of this application;

[0048] Figure 2 yes Figure 1 A schematic diagram of the provided energy storage device;

[0049] Figure 3 yes Figure 2 The diagram shows the structure of the end cap assembly.

[0050] Figure 4 yes Figure 3 An exploded view of the end cap assembly shown;

[0051] Figure 5 yes Figure 4 A schematic diagram of the current collector at one angle is shown.

[0052] Figure 6 yes Figure 5 The diagram shows the structure of the current collector from another angle;

[0053] Figure 7 yes Figure 5 A schematic diagram of the current collector from another angle;

[0054] Figure 8 yes Figure 3 The diagram shows the structure of the end cap;

[0055] Figure 9 yes Figure 8 A cross-sectional schematic diagram of the end cap assembly shown;

[0056] Figure 10 yes Figure 3 A cross-sectional schematic diagram of the end cap is shown;

[0057] Figure 11 yes Figure 3 A schematic cross-sectional view of the breathable component shown;

[0058] Figure 12 yes Figure 3 Another cross-sectional schematic diagram of the breathable component shown;

[0059] Figure 13 yes Figure 3 A schematic diagram of a breathable component is shown.

[0060] Figure 14 yes Figure 3 Another structural schematic diagram of the breathable component shown;

[0061] Figure 15 yes Figure 3 This is another structural schematic diagram of the breathable component shown.

[0062] Reference numerals: Residential energy storage system 1000, conversion device 100, one type of user load 200, another type of user load 300, energy storage device 400, single cell 410, end cap assembly 411, housing 412, current collector 413, end cap 414, ventilated assembly 415, current collector body 4131, first connecting part 4132, second connecting part 4133, first surface 4134, second surface 4135, first column 4136, second column 4137, third column 4138, first mounting hole 4141, liquid injection hole 4146, vent hole 4139, abutment plate 4140, explosion-proof hole 4142, first hole 4143, second hole 4144, receiving groove 4145, ventilated membrane body 4151, first seal Sealing ring 4152, second sealing ring 4153, second mounting hole 4154, explosion-proof valve 418, first surface 4159, second surface 4160, third surface 4155, fourth surface 4156, fifth surface 4157, sixth surface 4158, sealing strip 4161, first diaphragm flap 4162, second diaphragm flap 4163, first end 4164, second end 4165, third end 4166, fourth end 4167, distance D1 between the first end 4164 of the first diaphragm flap 4162 and the third end 4166 of the second diaphragm flap 4163, distance D2 between the second end 4165 of the first diaphragm flap 4162 and the fourth end 4167 of the second diaphragm flap 4163, reinforcing rib 417, first reinforcing rib 4171, second reinforcing rib 4172. Detailed Implementation

[0063] For ease of understanding, the terminology used in the embodiments of this application will be explained first.

[0064] And / or: This is simply a way of describing the relationship between related objects. It indicates that there can be three kinds of relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0065] Multiple: refers to two or more.

[0066] Connection: should be interpreted broadly. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through an intermediary.

[0067] The specific embodiments of this application will now be clearly described in conjunction with the accompanying drawings.

[0068] Because the energy we need is highly time- and space-dependent, in order to utilize energy rationally and improve its efficiency, we need a medium or device to store one form of energy in the same form or by converting it into another, and then release it in a specific energy form based on future application needs. As is well known, the main way to generate green electricity is currently through the development of green energy sources such as photovoltaics and wind power to replace fossil fuels.

[0069] Currently, the generation of green electricity generally relies on solar, wind, and hydropower. However, wind and solar power are generally characterized by strong intermittency and large fluctuations, which can cause grid instability, insufficient power during peak demand periods, and excessive power during off-peak periods. Unstable voltage can also damage the power grid. Therefore, insufficient electricity demand or grid capacity may lead to the problem of "wind and solar curtailment." Solving these problems requires energy storage. This involves converting electrical energy into other forms of energy through physical or chemical means and storing it. When needed, this energy can be converted back into electricity and released. Simply put, energy storage is like a large "power bank," storing electrical energy when solar and wind power are abundant and releasing the stored electricity when needed.

[0070] Taking electrochemical energy storage as an example, this solution provides an energy storage device. The energy storage device is equipped with a chemical battery, which mainly uses the chemical elements in the chemical battery as the energy storage medium. The charging and discharging process is accompanied by the chemical reaction or change of the energy storage medium. Simply put, the electrical energy generated by wind and solar energy is stored in the chemical battery. When the use of external electrical energy reaches its peak, the stored electricity is released for use, or transferred to places with a shortage of electricity for use.

[0071] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, renewable energy grid-connected energy storage, and user-side energy storage. The corresponding types of energy storage devices include:

[0072] (1) Large energy storage containers used in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the grid, enabling load matching of electrical energy in time and space, enhancing the absorption capacity of renewable energy, and playing a significant role in grid system backup, alleviating peak load power supply pressure, and peak regulation and frequency regulation.

[0073] (2) Small and medium-sized energy storage cabinets used in commercial and industrial energy storage scenarios (banks, shopping malls, etc.) and small household energy storage boxes used in residential energy storage scenarios primarily operate under the "peak shaving and valley filling" mode. Because there are significant price differences in electricity during peak and off-peak periods based on demand, users with energy storage devices typically charge the cabinets / boxes during off-peak periods and release the electricity during peak periods to save on costs. Furthermore, in remote areas and regions prone to natural disasters such as earthquakes and hurricanes, the presence of household energy storage devices effectively provides backup power for users and the power grid, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0074] This application uses a residential energy storage scenario in user-side energy storage as an example for illustration. Please refer to [link / reference]. Figure 1 , Figure 1 This is the residential energy storage system 1000 provided in the embodiments of this application.

[0075] The residential energy storage system 1000 includes a power conversion device 100 (photovoltaic panel), a user load 200 (streetlight), another user load 300 (household appliance), and an energy storage device 400. The energy storage device 400 is a small energy storage box that can be wall-mounted to an outdoor wall. Specifically, the photovoltaic panel converts solar energy into electricity during periods of low electricity prices, and the energy storage device 400 stores this electricity and supplies it to streetlights and household appliances during peak electricity prices, or provides power during grid outages. It should be noted that the energy storage device 400 in this application is not limited to residential energy storage scenarios.

[0076] Please see Figure 2 , Figure 2 yes Figure 1 A schematic diagram of the provided energy storage device 400 is shown. The energy storage device 400 may include multiple individual battery cells 410, arranged in an array. The multiple individual battery cells 410 may be electrically connected in series, parallel, or a combination of series and parallel connections.

[0077] The single-cell battery 410 includes an end cap assembly 411, a housing 412, an electrode assembly (not shown), and an electrolyte (not shown). The end cap assembly 411 can be sealed to the housing 412 to form a receiving space. The electrode assembly and the electrolyte can be located in the receiving space, and the electrode assembly can be immersed in the electrolyte.

[0078] Currently, the current collector of a single-cell battery is often formed into a two-stage stacked structure by bending. The two stages of the stacked current collector are electrically connected to the end caps and electrode assemblies located on opposite sides of the current collector. However, because the current collector approaches the metal fatigue limit after bending, it is prone to breakage due to vibration during use, leading to the failure of the single-cell battery.

[0079] Based on this, this application provides an end cap assembly 411 that can be electrically connected to the electrode assembly and the end cap without bending the current collector.

[0080] Please refer to the following: Figure 3 and Figure 4 , Figure 3 yes Figure 2 The diagram shown is a structural schematic of the end cap assembly 411. Figure 4 yes Figure 3 The diagram shows an exploded view of the end cap assembly 411. The end cap assembly 411 may include a current collector 413, an end cap 414, and a venting assembly 415. The electrode assembly, current collector 413, venting assembly 415, and end cap 414 of the single cell 410 are stacked sequentially.

[0081] It should be noted that, Figure 3 The purpose is merely to illustratively describe the connection relationship between the manifold 413, end cap 414, and venting assembly 415, and is not to specifically limit the connection positions, specific structures, or quantities of each device. Furthermore, the structures illustrated in the embodiments of this application do not constitute a specific limitation on the end cap assembly 411. In other embodiments of this application, the end cap assembly 411 includes... Figure 3 This may involve more or fewer components, or combining certain components, or splitting certain components, or different component arrangements. Figure 3 The components shown can be implemented in hardware, software, or a combination of both.

[0082] Please refer to the following: Figure 5 , Figure 6 and Figure 7 , Figure 5 yes Figure 4 The diagram shows a structural schematic of the current collector 413 at one angle. Figure 6 yes Figure 5 The diagram shows another angle of the current collector 413. Figure 7 yes Figure 5 The diagram shows a structural view of the current collector 413 from another angle. The current collector 413 includes a current collector body 4131, a first connecting portion 4132, and a second connecting portion 4133. The current collector body 4131 includes a first surface 4134 and a second surface 4135 disposed opposite to each other along the thickness direction. The first surface 4134 is disposed facing the end cap 414, and the second surface 4135 is disposed away from the end cap 414. The first connecting portion 4132 is connected to the first surface 4134, and the second connecting portion 4133 is connected to the second surface 4135.

[0083] Currently, current collectors are typically manufactured as multi-segment structures. These segments are then bent to form a stacked structure, which can then be installed inside the housing. The opposite sides of the stacked structure along its thickness can be electrically connected to the end cap and the motor assembly, respectively. However, bending the current collector causes the bent portion to reach its metal fatigue limit; therefore, the bent section of the current collector is highly susceptible to fracture, leading to the failure of the individual battery cell.

[0084] In this application, the first connecting part 4132 and the second connecting part 4133 are respectively disposed on opposite sides of the current collector body 4131. This allows the first connecting part 4132 on one side of the current collector body 4131 to connect to the end cap 414, and the second connecting part 4133 on the other side of the current collector body 4131 to connect to the electrode assembly. Thus, the first connecting part 4132 and the second connecting part 4133 are both integrated on the current collector body 4131. The current collector body 4131 can be electrically connected to the end cap 414 and the electrode assembly and installed inside the housing of the single cell 410 without bending, effectively avoiding the problem of single cell 410 failure due to breakage caused by bending of the current collector 413.

[0085] The first connecting portion 4132 protrudes from the first surface 4134. The orthographic projection of the first connecting portion 4132 onto the first surface 4134 falls within the area of ​​the first surface 4134. For example, the first connecting portion 4132 may be located in the central region of the first surface 4134. The first connecting portion 4132 may be a protruding pillar structure.

[0086] Specifically, the first connecting portion 4132 may include a first column 4136, a second column 4137, and a third column 4138. The first column 4136, the second column 4137, and the third column 4138 are connected sequentially. One side of the first column 4136 is connected to the current collecting body 4131, and the first column 4136 may be connected at the center of the current collecting body 4131. The other side of the first column 4136, away from the current collecting body 4131, is connected to the second column 4137. The radial dimension of the first column 4136 may remain unchanged in the thickness direction of the current collecting member 413. That is, the shape of the first column 4136 may be cylindrical.

[0087] The second column 4137 is connected to the end face of the first column 4136 away from the current collecting body 4131. The radial dimension of the side of the second column 4137 connected to the first column 4136 can be smaller than the radial dimension of the first column 4136. The maximum radial dimension of the second column 4137 is smaller than the minimum radial dimension of the first column 4136. The radial dimension of the second column 4137 gradually decreases in the direction away from the first column 4136. For example, the shape of the second column 4137 can be a frustum. The circumferential surface of the second column 4137 can be the circumferential surface of a frustum.

[0088] It is understood that when the current collector 413 is assembled with the end cap 414, the second pillar 4137 can be located within the first mounting hole 4141 of the end cap 414, as described below. The first pillar 4136 can be located within the gap between the end cap 414 and the current collector body 4131. The two ends of the first pillar 4136 along the height direction are respectively connected to the current collector body 4131 and the end cap 414. The first pillar 4136 can act as a spacer between the end cap 414 and the current collector body 4131, ensuring that there is always a certain distance between them. The gap between the end cap 414 and the current collector body 4131 can form a gas chamber. The gas chamber can contain all or part of the gas when the pressure inside the single cell 410 is too high. When the pressure inside the gas chamber exceeds a safe value, the gas can break through the explosion-proof valve 418 on the end cap 414 to release pressure, thereby preventing the single cell 410 from exploding.

[0089] The third column 4138 is connected to the end face of the second column 4137 away from the first column 4136. The radial dimension of the side of the third column 4138 connected to the second column 4137 can be the same as the minimum radial dimension of the second column 4137. For example, the shape of the third column 4138 can be a frustum. The circumferential surface of the third column 4138 can be the circumferential surface of a frustum. Alternatively, the third column 4138 can also be a cylinder, and the circumferential surface of the third column 4138 can be the circumferential surface of a cylinder. That is, the radial dimension of the third column 4138 can always remain unchanged.

[0090] The first connecting portion 4132 may also be provided with an injection hole 4146, which penetrates the first column 4136, the second column 4137, and the third column 4138 of the first connecting portion 4132 along the thickness direction of the current collector 413. The injection hole 4146 can provide a channel for electrolyte injection after the end cap assembly 411 of the single cell 410 is connected to the housing 412 and other components.

[0091] The second connecting portion 4133 is connected to the second surface 4135. The second connecting portion 4133 protrudes relative to the second surface 4135. The orthographic projection of the second connecting portion 4133 onto the second surface 4135 falls within the area of ​​the second surface 4135. The corresponding position of the second connecting portion 4133 on the first surface 4134 is recessed relative to the first surface 4134. The second connecting portion 4133 extends radially along the center of the current collecting body 4131. There can be multiple second connecting portions 4133, which are circumferentially spaced along the first connecting portion 4132. For example, there can be three second connecting portions 4133, which are circumferentially spaced along the first connecting portion 4132. The angle between two adjacent second connecting portions 4133 can be 60°. A region is formed between every two second connecting portions 4133. The three second connecting portions 4133 divide the current collecting body 4131 into three regions.

[0092] It is understood that the second connecting portion 4133 protrudes from the second surface 4135 of the current collector body 4131 toward the electrode assembly of the single cell 410. Therefore, the second connecting portion 4133 can be welded to the electrode assembly, thereby realizing the electrical connection between the current collector 413 and the electrode assembly. Since the second connecting portion 4133 extends from the edge to the center, both the outer and inner electrode plates of the electrode assembly can contact the second connecting portion 4133 to form an electrical connection, resulting in better reliability of the electrical connection.

[0093] The manifold 413 also includes multiple vent holes 4139 and multiple abutment plates 4140. Each vent hole 4139 penetrates the manifold body 4131 along its thickness direction. The multiple vent holes 4139 are spaced apart from the first connecting portion 4132 and the multiple second connecting portions 4133. The multiple vent holes 4139 are spaced apart on the manifold body 4131. Figure 4 As shown, multiple vent holes 4139 can be evenly distributed in three regions between the three second connecting parts 4133.

[0094] Understandably, the vent 4139 allows gas or liquid from the individual battery 410 to pass through. When the internal pressure of the individual battery 410 becomes too high, the gas and / or liquid inside the individual battery 410 first pass through the vent 4139, and then force open the explosion-proof valve on the end cover 414 to release pressure, thus preventing the individual battery 410 from exploding.

[0095] In addition, as the fluid passes through the vent holes 4139 of the manifold 413, the solid structure of the manifold body 4131 between the vent holes 4139 and the first connecting part 4132 can intercept the debris flowing with the fluid, preventing the debris from passing through the manifold body 4131 and accumulating at the explosion-proof valve of the end cover 414, which would cause the explosion-proof valve of the end cover 414 to be blocked and malfunction.

[0096] Multiple abutment plates 4140 can be connected to the outer periphery of the collecting body 4131. The multiple abutment plates 4140 are spaced apart circumferentially along the collecting body 4131. All abutment plates 4140 are arranged at right angles to the collecting body 4131. The abutment plates 4140 are spaced apart from the second connecting portions 4133. The abutment plates 4140 extend from the periphery of the collecting body 4131 toward the side of the collecting body 4131 where the first connecting portion 4132 is located. That is, the abutment plates 4140 extend from the periphery of the collecting body 4131 toward the end cap 414. For example, there can be nine abutment plates 4140. Every three abutment plates 4140 can be located at the edge of an area formed by two adjacent second connecting portions 4133.

[0097] It is understandable that by placing the abutment plate 4140 in the gap area between the current collector body 4131 and the end cap 414, on the one hand, when the current collector 413 is pushed towards the end cap 414 by the electrode assembly (such as when a single cell 410 falls), the abutment plate 4140 is driven to abut against the surface of the end cap 414 facing the current collector 413, providing good cushioning and shock absorption, effectively preventing the current collector 413 from deforming due to impact, which could ultimately lead to the failure of the single cell 410. On the other hand, both the abutment plate 4140 and the first pillar 4136 of the first connecting portion 4132 can act as spacers between the current collector body 4131 and the end cap 414. Under the synergistic effect of the abutment plate 4140 and the first pillar 4136, there is always a certain gap between the current collector body 4131 and the end cap 414. The gap between the current collector body 4131 and the end cap 414 can form a gas chamber. Gas generated by the electrode assembly during operation can collect in the gas chamber. As the gas flows through the vent 4139 into the gas chamber, the debris (which may be tab fragments or insulating film fragments) moving with the gas can be intercepted by the barrier structure formed between the multiple vents 4139 of the current collector body 4131. This prevents the debris from moving to the position near the end cap 414 in the gas chamber, thus avoiding the debris moving to the explosion-proof hole 4142 of the end cap 414 and covering the explosion-proof valve 418, causing the explosion-proof valve 418 to fail.

[0098] Please see Figure 8 , Figure 8 yes Figure 3The diagram shows the structure of the end cap 414. The end cap 414 has a first mounting hole 4141 and an explosion-proof hole 4142. The first mounting hole 4141 extends through the end cap 414 along its thickness direction. The first mounting hole 4141 can be located at the center of the end cap 414 and is used to mutually limit the movement of the first connecting part 4132. When the end cap 414 is assembled with the manifold 413, the first pillar 4136 of the first connecting part 4132 is located in the gap area between the end cap 414 and the manifold body 4131. The second pillar 4137 and the third pillar 4138 are located within the first mounting hole 4141. The explosion-proof hole 4142 is spaced apart from the first mounting hole 4141 and is used for a sealed connection with the explosion-proof valve 418.

[0099] Please see Figure 9 , Figure 9 yes Figure 8 The diagram shows a cross-sectional view of the end cap assembly 411. The first mounting hole 4141 includes a first hole 4143 and a second hole 4144 that are connected. The first hole 4143 is used to mutually limit the movement of the second pillar 4137, and the second hole 4144 is used to mutually limit the movement of the third pillar 4138. The first hole 4143 and the second hole 4144 are arranged sequentially in the direction from the end cap 414 toward the collector 413. In the direction away from the collector body 4131, the radial dimension of the first hole 4143 can gradually decrease. Alternatively, in the direction away from the collector body 4131, the radial dimension of the first hole 4143 can remain unchanged.

[0100] The minimum radial dimension of the second hole 4144 can be equal to the maximum radial dimension of the first hole 4143. The radial dimension at the intersection of the hole wall of the second hole 4144 and the hole wall of the first hole 4143 is the minimum radial dimension of the second hole 4144 and the maximum radial dimension of the first hole 4143. The radial dimension of the second hole 4144 gradually decreases in the direction away from the current collecting body 4131.

[0101] Please refer to the following: Figure 8 and Figure 9The end cap also includes a receiving groove 4145. The receiving groove 4145 is recessed at the end of the end cap 414 away from the current collector 413. The receiving groove 4145 is disposed around the first mounting hole and communicates with the first mounting hole 4141. Specifically, the receiving groove 4145 communicates with the first hole 4143 of the first mounting hole 4141. The radial dimension of the receiving groove 4145 may be larger than the radial dimension of the first hole 4143. The first hole 4143 may penetrate the bottom wall of the receiving groove 4145. When the first connecting part 4132 is assembled with the first mounting hole 4141, the groove wall of the receiving groove 4145 will form a gap with the outer surface of the third column 4138, and the gap can accommodate the solder connecting the first connecting part 4132 of the current collector 413 and the end cap 414. This allows the solder to remain within the receiving groove 4145 after the wall of the first mounting hole 4141 of the end cap 414 is welded to the first connecting part 4132, without overflowing the receiving groove 4145, and the surface of the end cap 414 away from the current collector 413 is relatively flat.

[0102] Please see Figure 10 , Figure 10 yes Figure 3 The diagram shows a cross-sectional view of the end cap 414. A gap exists between the current collector body 4131 and the end cap 414, and the first connecting portion 4132 of the current collector 413, away from the current collector body 4131, passes through the first mounting hole 4141. By forming a gap between the current collector body 4131 and the end cap 414, this gap can serve as a gas chamber. The gas chamber can contain the gas generated by the electrode assembly during operation. For example, the distance of the gap between the current collector body 4131 and the end cap 414 can range from 1.3 mm to 3.2 mm (inclusive of the endpoint values ​​of 1.3 mm and 3.2 mm).

[0103] The first column 4136 of the first connecting portion 4132 is located within the gap between the collector body 4131 and the end cap 414. The end face of the first column 4136 away from the collector body 4131 abuts against the surface of the end cap 414 facing the collector 413. The second column 4137 of the first connecting portion 4132 is located within the second hole 4144. The peripheral surface of the second column 4137 is mutually restrained by the hole wall of the second hole 4144. That is, the hole wall of the second hole 4144 can completely abut against the peripheral surface of the second column 4137. Alternatively, the slope of the hole wall of the second hole 4144 can be different from the slope of the peripheral surface of the second column 4137. The angle between the hole wall of the second hole 4144 and the central axis of the second hole 4144 is greater than the angle between the peripheral surface of the second column 4137 and the central axis of the second column 4137. The diameter of the side of the second hole 4144 facing away from the collector body 4131 can be the same as the diameter of the end of the second pillar 4137 facing away from the first pillar 4136. During assembly, the second pillar 4137 can slide completely into the second hole 4144 along the hole wall, thereby ensuring that the first pillar 4136 can abut against the surface of the end cap 414 facing the collector body 4131. Alternatively, the hole wall of the second hole 4144 can also have a gap with the peripheral surface of the second pillar 4137.

[0104] The third pillar 4138 of the first connecting portion 4132 is located within the first hole 4143. The peripheral side surface of the third pillar 4138 is mutually restrained by the hole wall of the first hole 4143. It is understood that the peripheral side surface of the third pillar 4138 and the hole wall of the first hole 4143 can abut against each other. Alternatively, there is a gap between the peripheral side surface of the third pillar 4138 and the hole wall of the first hole 4143. The surface of the third pillar 4138 away from the second pillar 4137 is flush with the bottom wall of the receiving groove 4145, thereby restraining the first connecting portion 4132 and the first mounting hole 4141.

[0105] It is understandable that the end face of the first column 4136 of the first connecting part 4132 can abut against the surface of the end cover 414 facing the collector 413, so that the end cover 414 and the collector body 4131 can always maintain a certain distance, and to a certain extent restrict the relative displacement between the end cover 414 and the collector body 4131, so as to avoid the end cover 414 squeezing the collector body 4131 and causing damage to the structure of the collector body 4131.

[0106] The second post 4137 of the first connecting part 4132 can be mutually restrained by the wall of the second hole 4144, thereby allowing the current collector 413 to be electrically connected to the end cap 414. Furthermore, since the wall of the second hole 4144 is inclined relative to the first surface 4134, the contact area between the second hole 4144 and the second post 4137 is larger than when the wall of the second hole 4144 is perpendicular to the first surface 4134. This increases the stability and reliability of the electrical connection between the current collector 413 and the end cap 414.

[0107] The third column 4138 of the first connecting part 4132 can be mutually limited with the hole wall of the first hole 4143. The hole wall of the first hole 4143 can limit the third column 4138 in the circumferential direction, thereby increasing the connection stability between the current collector 413 and the end cap 414.

[0108] Please refer to the following: Figure 4 and Figure 10 A venting assembly 415 is disposed between the manifold 413 and the end cap 414. The venting assembly 415 includes a venting membrane body 4151, a first sealing ring 4152, and a second sealing ring 4153. The venting membrane body 4151 has a second mounting hole 4154 that penetrates through it. The venting membrane body 4151 allows gas to pass through but not electrolyte. The wall of the second mounting hole 4154 is used for the passage of the first post 4136 of the first connecting portion 4132. The first sealing ring 4152 is surrounding the outer periphery of the second mounting hole 4154 and abuts against the end cap 414 and the manifold body 4131, sealingly connecting the end cap 414 and the manifold body 4131. The second sealing ring 4153 surrounds the outer periphery of the breathable membrane body 4151 and encloses the first sealing ring 4152 and the breathable membrane body 4151. The second sealing ring 4153 abuts against the end cap 414 and the manifold body 4131, sealingly connecting the end cap 414 and the manifold body 4131. The first sealing ring 4152, the second sealing ring 4153, and the breathable membrane body 4151 enclose the area below the explosion-proof valve 418 to form a sealed air chamber. The orthogonal projection of the explosion-proof valve 418 onto the breathable assembly 415 falls into the gap area between the first sealing ring 4152 and the second sealing ring 4153. For example, the material of the breathable membrane body 4151 can be expanded polytetrafluoroethylene (e-PTFE). Expanded polytetrafluoroethylene is a material that allows gas to pass through but not liquids.

[0109] Specifically, the first sealing ring 4152 abuts against the manifold body 4131 and the end cap 414 on opposite sides of the thickness direction of the venting assembly 415, and the second sealing ring 4153 abuts against the manifold body 4131 and the end cap 414 on opposite sides of the thickness direction of the venting assembly 415. The first sealing ring 4152 and the second sealing ring 4153 are interference-fitted with the manifold body 413 and the end cap 414, thereby forming a sealed air chamber between the end cap 414 and the manifold body 413.

[0110] Understandably, because the first sealing ring 4152 and the second sealing ring 4153 of the venting assembly 415 seal the air chamber between the end cap 414 and the current collector 413, the venting assembly 415 can ensure that after multiple cycles of use of the single cell 410, the gas generated by the electrode assembly passes through and accumulates in the space below the end cap 414. This prevents gas from overflowing from the edge of the end cap 414 or the first mounting hole 4141 of the end cap 414. When the pressure of the accumulated gas reaches a preset value, the gas can break through the explosion-proof valve 418 on the end cap 414 to release pressure, preventing the single cell 410 from exploding due to excessive internal pressure and improving the safety performance of the single cell 410.

[0111] Furthermore, because the pores of the venting component 415 allow gas to pass through while blocking water molecules, the electrolyte cannot pass through the venting component. This allows the second sealing ring 4153 and the first sealing ring 4152 to cooperate in enclosing a closed gas chamber between the end cap 414 and the current collector 413. Also, because the venting component 415 allows gas generated by the electrode assembly to enter the gas chamber through the venting component 415, while blocking the electrolyte on the side of the venting component 415 away from the end cap 414 from entering the gas chamber through the venting component 415, the electrolyte can remain within the space where the electrode assembly is located. The electrolyte can continuously wet the electrode sheets and provide ion channels, thus allowing the chemical reaction within the single cell 410 to proceed stably. This further improves the cycle life of the single cell 410. It effectively prevents the electrolyte on the side of the venting component 415 away from the end cap 414 from flowing into the gas chamber, thus preventing the electrode sheets from being wetted and causing the electrode assembly to be unable to carry out a chemical reaction.

[0112] Furthermore, when the internal pressure of the single cell 410 becomes too high and the explosion-proof valve 418 is opened, the gas inside the single cell 410 can escape from the gas chamber, thus depressurizing the single cell 410. During the depressurization process, the venting component 415 can prevent the electrolyte from being flushed out with the venting airflow, avoiding electrolyte contamination of other structural components around the single cell 410 (such as other batteries). At the same time, it also prevents toxic electrolyte from splashing and floating into the air, causing poisoning to humans or animals, further enhancing the safety performance of the single cell 410.

[0113] The thickness of the first sealing ring 4152 and the second sealing ring 4153 is greater than the thickness of the breathable membrane body 4151. The thickness of the first sealing ring 4152 and the thickness of the second sealing ring 4153 range from 2mm to 3.5mm (inclusive of the endpoint values ​​of 2mm and 3.5mm). The thickness of the first sealing ring 4152 and the thickness of the second sealing ring 4153 are greater than the gap between the manifold 413 and the end cap 414.

[0114] Understandably, since the manifold 413 and end cap assembly 411 are located on opposite sides of the venting assembly 415, the manifold 413 and end cap 414 can compress the venting assembly 415 from both sides, thereby deforming the first sealing ring 4152 and the second sealing ring 4153. After the manifold 413 and end cap 414 are assembled, the first sealing ring 4152 and the second sealing ring 4153 are deformed due to compression, and their thicknesses are reduced. The ratio of the compression amount of the first sealing ring 4152 and the second sealing ring 4153 to their initial thicknesses can be between 15% and 30% (inclusive of the endpoint values ​​of 15% and 30%). The ratio of the thickness of the first sealing ring 4152 and the second sealing ring 4153 to the gap height between the end cap 414 and the manifold 413 is between 1.1 and 1.5 (including the endpoint values ​​of 1.1 and 1.5).

[0115] It is understandable that when the ratio of the thickness of the first sealing ring 4152 and the second sealing ring 4153 to the gap between the end cap 414 and the manifold 413 is between 1.5 and 1.1, the first sealing ring 4152 and the second sealing ring 4153 can respectively abut tightly against the end cap 414 and the manifold 413 on opposite sides in the thickness direction, thereby forming a sealed air chamber between the end cap 414 and the manifold 413. Furthermore, the contact force between the first sealing ring 4152 and the second sealing ring 4153 and the end cap 414 and the manifold 413 will not be excessive, thus preventing excessive compression of the end cap 414 and the manifold 413 and ensuring the structural integrity.

[0116] For one possible implementation, please refer to Figure 11 , Figure 11 yes Figure 3The diagram shows a cross-sectional view of the breathable assembly 415. A first sealing ring 4152 and a second sealing ring 4153 protrude from a first surface 4159 relative to the breathable membrane body 4151, and are flush with a second surface 4160 relative to the breathable membrane body 4151. Specifically, the first sealing ring 4152 of the breathable assembly 415 includes a third surface 4155 and a fourth surface 4156 disposed opposite each other along the thickness direction of the breathable assembly 415. The second sealing ring 4153 of the breathable assembly 415 includes a fifth surface 4157 and a sixth surface 4158 disposed opposite each other along the thickness direction of the breathable assembly 415. The breathable membrane body 4151 includes a first surface 4159 and a second surface 4160 disposed opposite each other along its thickness direction. The third surface 4155, the fifth surface 4157, and the first surface 4159 are located on the same side of the breathable assembly 415 and all face the end cap 414. The fifth surface 4157 and the first surface 4159 abut against the end cap 414. The fourth surface 4156, the sixth surface 4158, and the second surface 4160 are located on the same side of the vent assembly 415 and all face the manifold 413. The sixth surface 4158 and the second surface 4160 abut against the manifold body 4131.

[0117] The third surface 4155 of the first sealing ring 4152 and the fifth surface 4157 of the second sealing ring 4153 protrude relative to the first surface 4159 of the breathable membrane body 4151. The fourth surface 4156 of the first sealing ring 4152 and the sixth surface 4158 of the second sealing ring 4153 are flush with the second surface 4160 of the breathable membrane body 4151. The height of the protrusion of the first sealing ring 4152 and the second sealing ring 4153 relative to the first surface 4159 of the breathable membrane body 4151 can range from 1.5mm to 2.5mm (including the endpoint values ​​of 1.5mm and 2.5mm).

[0118] Understandably, the flush arrangement of the fourth surface 4156, the sixth surface 4158, and the second surface 4160 allows the breathable membrane body 4151 to be flush with the surfaces of the first sealing ring 4152 and the second sealing ring 4153 near the collector 413, making the appearance of the breathable assembly 415 more concise.

[0119] For a second possible implementation, please refer to Figure 12 , Figure 12 yes Figure 3The illustrated cross-sectional view of the breathable assembly 415 differs from the first possible embodiment in that the first sealing ring 4152 and the second sealing ring 4153 both protrude from the first surface 4159 and the second surface 4160 of the breathable membrane body 4151. Specifically, the third surface 4155 of the first sealing ring 4152 and the fifth surface 4157 of the second sealing ring 4153 protrude from the first surface 4159 of the breathable membrane body 4151. The fourth surface 4156 of the first sealing ring 4152 and the sixth surface 4158 of the second sealing ring 4153 protrude from the second surface 4160 of the breathable membrane body 4151. The height at which the first sealing ring 4152 and the second sealing ring 4153 protrude from the first surface 4159 of the breathable membrane body 4151 can range from 0.5 mm to 1.5 mm (inclusive of the endpoint values ​​of 0.5 mm and 1.5 mm).

[0120] It is understandable that by placing the breathable membrane body 4151 in the middle of the thickness direction of the first sealing ring 4152 and the second sealing ring 4153, a larger gap can be formed between the breathable membrane body 4151 and the second connecting part 4133, thus preventing weld marks from protruding from the surface of the current collector 413 and scratching the breathable component 415 after the second connecting part 4133 of the current collector 413 is welded to the electrode assembly.

[0121] In the embodiments of this application, the breathable component 415 may also include one or more combinations of sealing strips, reinforcing ribs, and metal mesh. The structural possibilities of the breathable component 415 will be described below through three embodiments, but it should be understood that they are not limited thereto.

[0122] For the first possible implementation, please refer to [link / reference]. Figure 13 , Figure 13 yes Figure 3 The diagram shows a structural schematic of the breathable assembly 415. The breathable assembly 415 may further include a sealing strip 4161, which is connected to the surface of the second sealing ring 4153 facing the end cap 414, i.e., the fifth surface 4157 of the end cap 414. The sealing strip 4161 elastically abuts against the end cap 414 and the second sealing ring 4153. The sealing strip 4161 can be elastically deformed by compression from the end cap 414. A reinforcing rib 417 is connected to the breathable membrane body 4151. A metal mesh is located on the side of the breathable membrane body 4151 facing the end cap 414.

[0123] It is understandable that by providing a sealing strip 4161 between the second sealing ring 4153 and the end cap 414, the sealing performance between the second sealing ring 4153 and the end cap 414 can be further improved. This prevents electrolyte from seeping into the air chamber between the current collector 413 and the end cap 414 from the gap between the second sealing ring 4153 and the end cap 414.

[0124] The sealing strip 4161 includes a first membrane flap 4162 and a second membrane flap 4163. Both the first membrane flap 4162 and the second membrane flap 4163 are connected to the fifth surface 4157 of the second sealing ring 4153. The first membrane flap 4162 and the second membrane flap 4163 are spaced apart, with the first membrane flap 4162 surrounding the second membrane flap 4163. The distance between the first membrane flap 4162 and the second membrane flap 4163 gradually increases in the direction from the breathable membrane body 4151 to the end cap 414.

[0125] The first flap 4162 includes a first end 4164 and a second end 4165. The first end 4164 is connected to the fifth surface 4157 of the second sealing ring 4153. The second end 4165 is connected to the end cap 414.

[0126] The second flap 4163 includes a third end 4166 and a fourth end 4167. The third end 4166 is connected to the fifth surface 4157 of the second sealing ring 4153. The third end 4166 is located on the outer periphery of the first end 4164 of the first flap 4162. The fourth end 4167 is connected to the end cap 414. The fourth end 4167 is located on the outer periphery of the second end 4165 of the first flap 4162.

[0127] The distance D1 between the first end 4164 of the first flap 4162 and the third end 4166 of the second flap 4163 is less than the distance D2 between the second end 4165 of the first flap 4162 and the fourth end 4167 of the second flap 4163.

[0128] When the current collector 413 is pushed towards the end cap 414 by the electrode assembly (such as when a single cell 410 falls), the sealing strip 4161 can undergo elastic deformation. Under the pressure of the current collector 413, the second end 4165 of the first diaphragm flap 4162 and the fourth end 4167 of the second diaphragm flap 4163 will move towards the fifth surface 4157 of the second sealing ring 4153.

[0129] The sealing strip 4161 includes a first state and a second state. The first state is when the manifold 413 is not assembled with the end cap 414. In the first state, the distances between the second end 4165 of the first diaphragm flap 4162 and the fifth surface 4157 of the second sealing ring 4153, and the distances between the fourth end 4167 of the second diaphragm flap 4163 and the fifth surface 4157 of the second sealing ring 4153, are both first distances. The second state is the assembled state after the manifold 413 is assembled with the end cap 414. In the second state, the sealing strip 4161 is compressed by the end cap 414, and the distances between the second end 4165 of the first diaphragm flap 4162 and the fifth surface 4157 of the second sealing ring 4153, and the distances between the fourth end 4167 of the second diaphragm flap 4163 and the fifth surface 4157 of the second sealing ring 4153, are both second distances. The second distance is less than the first distance.

[0130] For a second possible implementation, please refer to Figure 14 , Figure 14 yes Figure 3 The diagram shows another structural schematic of the breathable assembly. The breathable assembly 415 may further include a reinforcing rib 417 located between the first sealing ring 4152 and the second sealing ring 4153. The thickness of the reinforcing rib 417 may be greater than the thickness of the breathable membrane body 4151. For example, the thickness of the reinforcing rib 417 may be the same as the thickness of the first sealing ring 4152. The two opposing surfaces of the reinforcing rib 417 along the thickness direction of the breathable assembly 415 may be flush with the third surface 4155 and the fourth surface 4156 of the first sealing ring 4152, respectively.

[0131] Understandably, the reinforcing rib 417 can further enhance the mechanical strength of the ventilated component 415, preventing the electrolyte from breaking through the ventilated component 415 and causing the explosion-proof valve 418 to be falsely triggered when the single cell 410 is accidentally dropped.

[0132] In one possible application scenario, please refer to [further details]. Figure 14 The reinforcing ribs 417 are arranged in a strip shape. There are multiple reinforcing ribs 417, spaced apart. All reinforcing ribs 417 are connected to the breathable membrane body 4151. Each reinforcing rib 417 has two ends connected to the first sealing ring 4152 and the second sealing ring 4153, respectively. For example, there can be eight reinforcing ribs 417. The eight reinforcing ribs 417 are arranged radially and spaced apart along the outer periphery of the first sealing ring 4152. One end of each reinforcing rib 417 is connected to the first sealing ring 4152, and the other end of each reinforcing rib 417 is connected to the second sealing ring 4153.

[0133] In another possible application scenario, please refer to Figure 15 , Figure 15 yes Figure 3This is another structural schematic diagram of the breathable component. Unlike the application scenario described above, the reinforcing rib 417 is arranged in a ring shape. The central axis of the reinforcing rib 417 coincides with the central axis of the first sealing ring 4152 and the central axis of the second sealing ring 4153. There can be multiple reinforcing ribs 417, spaced apart, each surrounding the first sealing ring 4152. For example, there are two reinforcing ribs 417: a first reinforcing rib 4171 and a second reinforcing rib 4172. The first reinforcing rib 4171 is connected to the breathable membrane body 4151 and surrounds the outer periphery of the first sealing ring 4152, with its inner circumferential surface spaced apart from the outer circumferential surface of the first sealing ring 4152. The second reinforcing rib 4172 is connected to the breathable membrane body 4151 and surrounds the outer periphery of the first reinforcing rib 4171. The inner circumferential surface of the second reinforcing rib 4172 is spaced apart from the outer circumferential surface of the first reinforcing rib 4171. The second sealing ring 4153 is disposed around the second reinforcing rib 4172. The inner circumferential surface of the second sealing ring 4153 is spaced apart from the outer circumferential surface of the second reinforcing rib 4172. For example, the shape formed by the first sealing ring 4152, the first reinforcing rib 4171, the second reinforcing rib 4172 and the second sealing ring 4153 can be four concentric circles nested in sequence.

[0134] In a third possible embodiment, the breathable assembly 415 may further include a metal mesh connected to the surface of the breathable membrane body 4151 facing the end cap 414. The metal mesh has a third mounting hole at its center. A second mounting hole 4154 is used for the passage of the first post 4136 of the first connecting portion 4132. The outer edge of the metal mesh may be connected to the inner circumferential surface of the second sealing ring 4153. The periphery of the third mounting hole of the metal mesh may be connected to the outer circumferential surface of the first sealing ring 4152. The metal mesh may be integrally injection molded with the breathable membrane body 4151, the first sealing ring 4152, and the second sealing ring 4153. Alternatively, the metal mesh may be separately molded and fixedly connected to the breathable membrane body using common connection methods. For example, the metal mesh may be a stainless steel mesh.

[0135] Understandably, a strong metal mesh can provide support for the breathable membrane body 4151, making it less prone to deformation and giving the breathable component 415 stronger impact resistance.

[0136] In the embodiments of this application, when the current collector 413 is assembled with the venting assembly 415, the first sealing ring 4152 is sleeved on the outer periphery of the first column 4136 of the first connecting portion 4132. The distance between the inner wall of the first sealing ring 4152 and the peripheral side of the first connecting portion 4132 is between 1.5mm and 3.5mm (including the endpoint values ​​of 1.5mm and 3.5mm). It can be understood that the gap between the first sealing ring 4152 and the peripheral side of the first connecting portion 4132 can be used to accommodate the welding slag generated when welding the first connecting portion 4132 of the current collector 413 and the end cap 414, preventing the welding slag from falling into the single cell 410 and causing an internal short circuit.

[0137] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An end cap assembly (411), characterized in that, include: An end cap (414) is provided with a first mounting hole (4141) and an explosion-proof hole (4142), the first mounting hole (4141) and the explosion-proof hole (4142) penetrating the end cap (414) along its thickness direction; and A current collector (413) includes a current collector body (4131), a first connecting portion (4132), and a second connecting portion (4133). The current collector body (4131) includes a first surface (4134) and a second surface (4135) disposed opposite to each other. The first surface (4134) is disposed facing the end cap (414). The first connecting portion (4132) is connected to the first surface (4134) and protrudes from the first surface (4134). The first connecting part (4132) is located in the central region of the current collecting body (4131), and part of the first connecting part (4132) is located in the first mounting hole (4141). The second connecting part (4133) is connected to the second surface (4135). The second connecting part (4133) is recessed relative to the first surface (4134) and protrudes relative to the second surface (4135). The second connecting part (4133) extends along the radial direction of the center of the current collecting body (4131). A breathable assembly (415) is disposed between the manifold (413) and the end cap (414). The breathable assembly (415) includes a breathable membrane body (4151), a first sealing ring (4152), and a second sealing ring (4153). The breathable membrane body (4151) includes a second mounting hole (4154), which surrounds a portion of the first connecting part (4132). The first sealing ring (4152) is circumferentially connected to the second sealing ring. The second sealing ring (4153) is connected around the outer periphery of the assembly hole (4154) and surrounds the first sealing ring (4152). The thickness of the first sealing ring (4152) and the second sealing ring (4153) is greater than the thickness of the breathable membrane body (4151). The thickness of the first sealing ring (4152) and the thickness of the second sealing ring (4153) are both greater than the gap height between the manifold (413) and the end cap (414). An explosion-proof valve (418) is connected to the explosion-proof hole (4142), and the projection of the explosion-proof hole (4142) onto the venting assembly (415) is located in the gap area between the first sealing ring (4152) and the second sealing ring (4153).

2. The end cap assembly (411) according to claim 1, characterized in that, The first connecting part (4132) includes a first column (4136) and a second column (4137). The first column (4136) is connected to the first surface (4134), and the second column (4137) is connected to the end face of the first column (4136) away from the first surface (4134). The minimum radial dimension of the first column (4136) is greater than the maximum radial dimension of the second column (4137). The first column (4136) abuts against the surface of the end cap (414) facing the collector (413), and the second column (4137) is mutually restrained by the wall of the first assembly hole (4141).

3. The end cap assembly (411) according to claim 2, characterized in that, The first connecting part (4132) further includes a third column (4138), which is connected to the end face of the second column (4137) away from the first column (4136), and the third column (4138) is a cylinder; The first assembly hole (4141) includes a first hole (4143) and a second hole (4144) arranged sequentially along the direction of the end cap (414) toward the manifold (413). The first hole (4143) communicates with the second hole (4144). The second column (4137) and the hole wall of the second hole (4144) mutually limit each other. The third column (4138) and the hole wall of the first hole (4143) mutually limit each other.

4. The end cap assembly (411) according to claim 3, characterized in that, The collector (413) further includes a plurality of abutment plates (4140) connected to the outer periphery of the collector body (4131). The plurality of abutment plates (4140) are arranged at intervals along the circumference of the collector body (4131). The plurality of abutment plates (4140) are located in the gap area between the collector body (4131) and the end cap (414). Each abutment plate (4140) is arranged at a right angle to the collector body (4131).

5. The end cap assembly (411) according to claim 4, characterized in that, The ratio of the thickness of the first sealing ring (4152) and the second sealing ring (4153) to the gap height between the end cap (414) and the manifold (413) is between 1.5 and 1.

1.

6. The end cap assembly (411) according to claim 5, characterized in that, The thickness of the first sealing ring (4152) and the second sealing ring (4153) is between 2mm and 3.5mm.

7. The end cap assembly (411) according to claim 5 or 6, characterized in that, The distance between the inner wall of the first sealing ring (4152) and the peripheral side of the first connecting part (4132) is between 1.5mm and 3.5mm.

8. The end cap assembly (411) according to claim 7, characterized in that, The breathable membrane body (4151) includes a first side (4159) and a second side (4160) arranged opposite to each other, the first side (4159) facing the end cap (414) and the second side (4160) facing the collector (413). The first sealing ring (4152) and the second sealing ring (4153) are both protruding from the first surface (4159) and the second surface (4160); Alternatively, the first sealing ring (4152) and the second sealing ring (4153) protrude from the first surface (4159), and the first sealing ring (4152) and the second sealing ring (4153) are flush with the second surface (4160).

9. The end cap assembly (411) according to claim 8, characterized in that, The breathable assembly (415) further includes a first membrane flap (4162) and a second membrane flap (4163). The first membrane flap (4162) and the second membrane flap (4163) are both connected to the surface of the second sealing ring (4153) facing the end cap (414). The end of the first membrane flap (4162) facing away from the second sealing ring (4153) and the end of the second membrane flap (4163) facing away from the second sealing ring (4153) are both in contact with the end cap (414). The first membrane flap (4162) and the second membrane flap (4163) are spaced apart. The first membrane flap (4162) surrounds the second membrane flap (4163). In the direction from the breathable membrane body (4151) to the end cap (414), the distance between the first membrane flap (4162) and the second membrane flap (4163) gradually increases.

10. The end cap assembly (411) according to claim 8 or 9, characterized in that, The breathable component (415) further includes a reinforcing rib (417) located between the first sealing ring (4152) and the second sealing ring (4153); One end of the reinforcing rib (417) is connected to the first sealing ring (4152). The reinforcing rib (417) is arranged radially with the center of the breathable membrane body as the center, and the other end of the reinforcing rib (417) is connected to the second sealing ring (4153).

11. The end cap assembly according to claim 8 or 9, characterized in that, The breathable component (415) further includes a reinforcing rib (417), which is annular and located between the first sealing ring (4152) and the second sealing ring (4153). The central axis of the reinforcing rib (417) coincides with the central axis of the first sealing ring (4152) and the central axis of the second sealing ring (4153).

12. The end cap assembly (411) according to claim 11, characterized in that, The breathable component (415) also includes a metal mesh connected to the surface of the breathable membrane body (4151) facing the end cap (414).

13. An energy storage device (400), characterized in that, Includes an electrode assembly and an end cap assembly (411) as claimed in any one of claims 1-12, wherein the current collector (413) is electrically connected to the electrode assembly on the side opposite to the end cap (414).

14. A residential energy storage system (1000), characterized in that, The load (300) includes the energy storage device (400) as described in claim 13, the energy storage device (400) being used to supply power to the load (300).

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