Energy storage device and energy storage system

Abstract

The invention discloses an energy storage device and an energy storage system.The energy storage device comprises a shell, a naked battery cell, an end cover assembly, a rubber nail and a sealing piece, the shell is provided with an inner cavity and an opening communicated with the inner cavity, the naked battery cell is arranged in the inner cavity, the end cover assembly comprises an end cover plate, the end cover plate is arranged at the opening in a sealed mode and provided with a first surface and a second surface which are opposite, and the rubber nail is arranged on the first surface. The end cover plate is provided with a through liquid injection hole, the rubber nail penetrates through the liquid injection hole, the sealing piece is located on the first surface, the liquid injection hole is covered with the sealing piece in a sealing mode, the sealing piece is welded to the end cover plate, the rubber nail comprises a cylinder part and an end part which are connected, the cylinder part penetrates through the liquid injection hole, and a first channel is formed between the peripheral face of the cylinder part and the hole wall face of the liquid injection hole. The radial size of the end portion is larger than that of the liquid injection hole so that a step face can be constructed, the end portion and the step face are located on the side, away from the first surface, of the second surface, a second channel is formed between the step face and the second surface, and the second channel is communicated with the first channel and the inner cavity of the shell.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and in particular to an energy storage device and energy storage system. Background Technology

[0002] Batteries in related technologies typically include a casing, bare cells, and end caps. The bare cells are housed within the inner cavity of the casing, and the end caps seal the opening of the casing to achieve a seal within the inner cavity. The end caps usually have an injection hole, through which electrolyte is injected into the inner cavity of the casing, immersing the bare cells in the electrolyte.

[0003] In the battery manufacturing process of related technologies, after the electrolyte is injected, a small amount of helium is introduced. Then, adhesive pins and welded sealing aluminum pins are used to permanently seal the injection port. Helium testing is then performed to check the seal between the sealing aluminum pin and the injection port. However, there is a chance that the adhesive pins may temporarily seal the injection port after being inserted, preventing helium from diffusing through the injection port to the area beneath the sealing aluminum pin within a short period. This means that even if there are minute gaps in the weld between the sealing aluminum pin and the injection port, they cannot be detected by the helium testing process. Summary of the Invention

[0004] This invention discloses an energy storage device and system capable of helium detection to avoid poor sealing performance caused by poor welding of the sealing sheet, thereby ensuring the welding sealing performance of the sealing sheet and guaranteeing the safety, sealing and stability of the energy storage device.

[0005] To achieve the above objectives, in a first aspect, the present invention discloses an energy storage device, the energy storage device comprising:

[0006] A housing having an inner cavity and an opening communicating with the inner cavity;

[0007] Bare battery cell, wherein the bare battery cell is embedded in the inner cavity;

[0008] An end cap assembly includes an end cap plate, which is sealed at the opening. The end cap plate has a first surface and a second surface opposite to each other along its thickness direction. The first surface is disposed away from the bare cell, and the end cap plate is provided with a liquid injection hole that passes through the first surface and the second surface.

[0009] Adhesive nails, the adhesive nails being inserted into the injection hole; and,

[0010] A sealing sheet is located on the first surface, and the sealing sheet is provided to seal the injection hole and is welded to the end cover plate;

[0011] The adhesive nail includes a column portion and an end portion connected along the thickness direction. The column portion passes through the injection hole, and a first channel is formed between the outer peripheral surface of the column portion and the hole wall surface of the injection hole. The radial dimension of the end portion is larger than the radial dimension of the injection hole to form a stepped surface. The end portion and the stepped surface are both located on the side of the second surface away from the first surface. A second channel is formed between the stepped surface and the second surface. The second channel connects the first channel and the inner cavity of the housing.

[0012] In the energy storage device provided in this application, the adhesive pin includes a column portion and an end portion connected along its axial direction. The column portion passes through the injection hole of the end cover plate, and a first channel is formed between the outer peripheral surface of the column portion and the wall surface of the injection hole. The radial dimension of the end portion is larger than the radial dimension of the injection hole to construct a stepped surface. The end portion and the stepped surface are located outside the injection hole and on the side of the second surface opposite to the first surface. A second channel is formed between the stepped surface and the second surface. The second channel communicates with the first channel and the inner cavity of the shell, so that the helium gas injected into the inner cavity of the shell can be discharged sequentially through the second channel and the first channel to the weld between the sealing plate and the end cover plate. In subsequent helium gas detection, it is possible to accurately detect whether the sealing plate is welded well, thereby avoiding the problem of poor sealing effect due to poor sealing plate welding. This effectively ensures the safety, sealing and stability of the energy storage device.

[0013] As an optional implementation, in an embodiment of the first aspect of the present invention, the step is recessed inward in the direction away from the second surface, and the recessed portion communicates with the first channel. This application also allows the recessed portion, which communicates with the first channel, to collect welding slag, metal shavings, and other impurities entering through the first channel during welding of the sealing sheet and the end cover plate. This reduces the probability of welding slag and metal shavings splashed during welding of the sealing sheet and the end cover plate entering the inner cavity of the casing through the second channel, thereby reducing the probability of short circuits in the bare cell and electrolyte contamination, and improving the battery performance and safety of the energy storage device.

[0014] As an optional implementation, in an embodiment of the first aspect of the present invention, the stepped surface abuts against the second surface, a first groove is provided on the outer periphery of the stepped surface, and / or a second groove is provided on the periphery of the second surface near the injection hole; the first groove and / or the second groove communicate with the first channel and / or the recess, and the first groove and / or the second groove communicate with the inner cavity of the housing; wherein the first groove and / or the second groove constitute the second channel.

[0015] By adopting the above design method, the stepped surface and the second surface can be stopped to prevent the helium from detaching from the injection hole along the direction away from the bare cell. At the same time, the helium gas injected into the inner cavity of the housing can be discharged to the weld of the sealing sheet and the end cover plate. This allows for accurate detection of whether the sealing sheet is welded well during subsequent helium gas testing, thereby avoiding the problem of poor sealing effect caused by poor sealing sheet welding. This effectively ensures the safety, sealing and stability of the energy storage device.

[0016] As an optional implementation, in an embodiment of the first aspect of the present invention, when the outer periphery of the stepped surface is provided with the first groove, the first groove penetrates the inner wall of the recessed portion to communicate with the first channel through the recessed portion, and the first groove also penetrates the outer peripheral side of the end to communicate with the inner cavity of the housing, wherein the first groove constitutes the second channel. This allows helium gas injected into the inner cavity of the housing to enter the first groove from the inlet of the first groove penetrating the outer peripheral side of the end, and to flow into the recessed portion and into the first channel from the outlet of the first groove penetrating the inner wall of the recessed portion, so as to be discharged to the welding joint of the sealing sheet and the end cover plate. This allows for accurate detection of whether the sealing sheet is properly welded during subsequent helium gas detection, avoiding poor sealing performance due to poor welding of the sealing sheet, thereby effectively ensuring the safety, sealing, and stability of the energy storage device.

[0017] As an optional implementation, in an embodiment of the first aspect of the present invention, when the second surface is provided with the second groove near the periphery of the injection hole, the second groove penetrates the groove wall of the injection hole to communicate with the first channel, and a portion of the second groove is exposed at the end to communicate with the inner cavity of the housing, wherein the second groove constitutes the second channel. This allows helium gas injected into the inner cavity of the housing to enter the second groove from the inlet formed by the exposed portion of the second groove at the end, and flow into the first channel from the outlet of the second groove penetrating the groove wall of the injection hole, so as to be discharged to the weld between the sealing sheet and the end cover plate. This allows for accurate detection of whether the sealing sheet is properly welded during subsequent helium gas testing, avoiding poor sealing performance due to poor welding of the sealing sheet, thereby effectively ensuring the safety, sealing, and stability of the energy storage device.

[0018] As an optional implementation, in an embodiment of the first aspect of the present invention, when the outer periphery of the stepped surface is provided with the first groove, and the periphery of the second surface near the injection hole is provided with the second groove, the second groove is provided corresponding to the first groove, and the opening of the second groove and the opening of the first groove face each other and communicate with each other. The first groove penetrates the inner wall of the recessed portion to communicate with the first channel through the recessed portion, and the first groove also penetrates the outer peripheral side of the end to communicate with the inner cavity of the housing; the second groove penetrates the groove wall of the injection hole to communicate with the first channel, and a portion of the second groove is exposed at the end to communicate with the inner cavity of the housing; wherein, the first groove and the second groove constitute the second channel.

[0019] Compared to designs that only have a first groove on the stepped surface or only have a second groove on the second surface, this design allows for a second channel with a relatively large diameter, increasing the flow rate of helium gas. This ensures that sufficient helium gas is discharged to the weld between the sealing plate and the end cover plate, thereby improving the detectability of subsequent helium gas detection and thus improving the accuracy of the helium gas detection process. It also helps to detect energy storage devices with abnormal sealing plate welding.

[0020] As an optional implementation, in an embodiment of the first aspect of the present invention, there are multiple second channels arranged at intervals. Compared to providing a single second channel with a large diameter, providing multiple second channels arranged at intervals is equivalent to forming a structure like a brush or brush surface. This can increase the flow rate of helium gas while making it less likely for welding slag, metal shavings, etc., to fall into the inner cavity of the casing through the second channels, thereby reducing the probability of short circuits in the bare cell and electrolyte contamination, and improving the battery performance and safety of the energy storage device.

[0021] As an optional implementation, in an embodiment of the first aspect of the invention, the stepped surface and the second surface are spaced apart to form a gap, the gap being in communication with the first channel; wherein the gap constitutes the second channel. This eliminates the need for grooves to be formed at the ends and / or end caps to create the second channel, thereby simplifying the formation of the second channel and simplifying the structure of the adhesive pins and end caps, as well as the processing technology of the adhesive pins and end caps.

[0022] As an optional implementation, in an embodiment of the first aspect of the present invention, the radial dimension of the injection hole is d1, and the radial dimension of the end is d2, wherein 1.02 ≤ d2 / d1 = 1.12.

[0023] By ensuring that the ratio of the radial dimension of the injection hole to the radial dimension of the end satisfies the above relationship, it is possible to ensure temporary sealing performance by allowing the end to be interference-fitted with the injection hole, while avoiding excessive interference between the end and the injection hole. This makes it easier for the end to pass through the injection hole when pressure is applied to the rubber nail later, thus reducing the difficulty of pressing the rubber nail further into the injection hole along the thickness direction of the end cover plate.

[0024] As an optional implementation, in an embodiment of the first aspect of the present invention, the end portion has an end face and an outer peripheral side face. The end face is disposed away from the sealing sheet, and the outer peripheral side face is connected between the end face and the stepped surface. A chamfer, such as a bevel or rounded corner, is formed at the connection between the outer peripheral side face and the end face. This chamfer acts as a guide when the adhesive nail is pressed into the injection hole, thereby improving the problem of difficulty in pressing the adhesive nail into the injection hole due to interference between the end of the adhesive nail and the injection hole. This helps ensure that the adhesive nail can be smoothly pressed into the injection hole, and that the end portion can smoothly pass through the injection hole and remain outside the injection hole.

[0025] As an optional implementation, in an embodiment of the first aspect of the present invention, the radial dimension of the cylindrical portion is smaller than the radial dimension of the injection hole, so that a gap is formed between the outer peripheral surface of the cylindrical portion and the hole wall surface of the injection hole, the gap communicating with the recessed portion, and the cylindrical portion being connected to the sealing sheet; wherein the gap constitutes the first channel.

[0026] The method described above for forming the first channel is simpler than the method of fitting the outer peripheral surface of the column and the wall of the injection hole together, and forming the first channel by opening grooves on the outer peripheral surface of the column and / or the wall of the injection hole. It also simplifies the structure of the glue pin and the end cap, and simplifies the processing technology of the glue pin and the end cap.

[0027] As an optional implementation, in the embodiment of the first aspect of the present invention, the adhesive pin and the sealing sheet are integrally formed. This allows the sealing sheet to be pressed into the injection hole along with the adhesive pin, thereby eliminating the original sealing sheet placement process. Specifically, it eliminates the steps of sealing sheet placement, alignment, and CCD positioning, thus greatly simplifying the process and reducing its complexity. Furthermore, it ensures the reliability between the adhesive pin and the sealing sheet.

[0028] As an optional implementation, in an embodiment of the first aspect of the present invention, the sealing sheet, the cylindrical portion, and the end portion are coaxially arranged. With this design, due to the interference fit between the end of the adhesive pin and the injection hole, the adhesive pin and the injection hole are coaxially arranged. Therefore, after the sealing sheet is pressed into the injection hole along with the adhesive pin, it can maintain a good concentricity relationship with the injection hole, thereby achieving the positioning function of the sealing sheet. This eliminates the need for additional external robotic arms for positioning and alignment; applying a force along the thickness direction of the end cover plate is sufficient to push it in and assemble it into place. This greatly simplifies the assembly steps of the sealing sheet and reduces the assembly difficulty.

[0029] As an optional implementation, in an embodiment of the first aspect of the present invention, the sealing sheet has a third surface disposed toward the column portion, the column portion has a fourth surface disposed toward the sealing sheet, one of the third surface and the fourth surface is provided with a connecting protrusion, the other of the third surface and the fourth surface is provided with a connecting groove, and the connecting protrusion is embedded in the connecting groove; the outer peripheral surface of the connecting protrusion is gradually inclined toward the central axis of the connecting protrusion in a direction away from the third surface or the fourth surface, and the inclination angle of the outer peripheral surface of the connecting protrusion is α1; the groove wall surface of the connecting groove is gradually inclined toward the central axis of the connecting groove in a direction away from the bottom surface of the connecting groove, and the inclination angle of the groove wall surface of the connecting groove is α2, wherein 0°≤|α1-α2|≤1°.

[0030] By incorporating a connecting protrusion and a connecting groove, the protrusion is embedded within the groove, facilitating the connection between the sealing sheet and the adhesive pin. The fit between the protrusion and groove also enables positioning of the sealing sheet and the cylindrical part, ensuring coaxial alignment of the sealing sheet, cylindrical part, and end cap. Furthermore, the draft angle of the outer circumference of the connecting protrusion and the draft angle of the groove wall satisfy the relationship 0°<|α1-α2|≤1°. This means that the draft angles of the outer circumference of the connecting protrusion and the groove wall are different. By allowing a difference between the inclination angle α1 of the outer circumference of the connecting protrusion and the inclination angle α2 of the groove wall, an interference fit is achieved, facilitating a tight fit between the connecting protrusion and the groove and improving the connection stability of the sealing sheet and adhesive pin.

[0031] Secondly, the present invention discloses an energy storage system having the energy storage device as described in the first aspect above. The energy storage system having the energy storage device described in the first aspect can also undergo helium detection to avoid poor sealing performance due to poor welding of the sealing sheet, thereby ensuring the welding sealing performance of the sealing sheet and guaranteeing the safety, sealing, and stability of the energy storage device.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] The energy storage device and system provided in this invention include a cylindrical part and an end portion connected axially along the glued nail. The cylindrical part passes through the injection hole of the end cover plate, and a first channel is formed between the outer peripheral surface of the cylindrical part and the wall surface of the injection hole. The radial dimension of the end portion is larger than the radial dimension of the injection hole to form a stepped surface. The end portion is located outside the injection hole and on the side of the second surface opposite to the first surface. A second channel is formed between the stepped surface and the second surface. The second channel communicates with the first channel and the inner cavity of the shell, so that the helium gas injected into the inner cavity of the shell can be discharged sequentially through the second channel and the first channel to the weld between the sealing sheet and the end cover plate. This allows for accurate detection of whether the sealing sheet is welded well during subsequent helium gas detection, thereby avoiding the problem of poor sealing effect due to poor sealing sheet welding. This effectively ensures the safety, sealing and stability of the energy storage device. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the first structure of the energy storage system disclosed in the embodiments of the present invention;

[0036] Figure 2 This is a schematic diagram of the second structure of the energy storage system disclosed in the embodiments of the present invention;

[0037] Figure 3 This is a schematic diagram of the energy storage device disclosed in an embodiment of the present invention;

[0038] Figure 4 This is an exploded structural diagram of the energy storage device disclosed in an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of the end cap assembly disclosed in an embodiment of the present invention;

[0040] Figure 6 This is an exploded structural diagram of the end cap assembly disclosed in an embodiment of the present invention;

[0041] Figure 7 This is a front view of the end cap assembly disclosed in an embodiment of the present invention;

[0042] Figure 8 The end cap assembly disclosed in the embodiments of the present invention is along Figure 7The first sectional view along the AA direction;

[0043] Figure 9 yes Figure 8 A magnified view of point M in the image;

[0044] Figure 10 The end cap assembly disclosed in the embodiments of the present invention is along Figure 7 The second sectional view along the AA direction;

[0045] Figure 11 When Figure 10 A magnified view of point N when the end of the rubber nail is outside the injection hole;

[0046] Figure 12 When Figure 10 A magnified view of point N when the end of the rubber nail is inside the injection hole;

[0047] Figure 13 When Figure 10 A first enlarged view of point N when the end of the middle rubber nail has a first groove;

[0048] Figure 14 When Figure 10 A second enlarged view of point N when the end of the middle rubber nail has the first groove;

[0049] Figure 15 When Figure 10 A partial enlarged view of point N when the middle cover plate has a second groove;

[0050] Figure 16 When Figure 10 A partial enlarged view of point N when the end of the middle rubber nail has a first groove and the end cover plate has a second groove;

[0051] Figure 17 This is a schematic diagram of the structure of the sealing sheet and adhesive nail disclosed in the embodiments of the present invention.

[0052] Explanation of main figure symbols

[0053] 1000-Energy Storage System;

[0054] 100 - Energy storage device; 10 - Housing; 11 - Inner cavity; 12 - Opening; 20 - Bare cell; 30 - End cap assembly; 31 - End cap plate; 31a - First surface; 31b - Second surface; 311 - Injection hole; 311a - First hole segment; 311b - Second hole segment; 311c - Stepped surface; 312 - Second groove; 32 - Adhesive nail; 321 - Columnar part; 3211 - First channel; 3212 - Fourth surface; 3213 - Connecting groove; 322 - End; 3221 - End face; 3222 - Outer peripheral side; 3223 - Chamfer; 323 - Stepped surface; 3231 - Second channel; 324 - Recess; 325 - First groove; 33 - Sealing plate; 331 - Third surface; 332 - Connecting protrusion;

[0055] 200 - Power conversion device; 300 - First user load; 400 - Second user load;

[0056] 210 - High voltage cable; 310 - First power conversion device; 410 - Second power conversion device. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0059] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first surface may be referred to as a second surface, and similarly, a second surface may be referred to as a first surface. Both the first surface and the second surface are surfaces of a component, but they are not the same surface.

[0060] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0061] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that terms such as “comprising / including” or “having” specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Furthermore, the term “and / or” as used in this specification is merely a description of the relationship between related objects, indicating that three relationships may exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. That is, the term “and / or” as used in this specification includes any and all combinations of the related listed items.

[0062] 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.

[0063] 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 electricity during peak demand periods, and excessive electricity during off-peak periods. Unstable voltage can also damage the power grid. Therefore, insufficient electricity demand or insufficient grid capacity may lead to the problem of "wind and solar curtailment." To solve these problems, energy storage is necessary. This involves converting electrical energy into other forms of energy through physical or chemical means and storing it, then releasing the energy back into electricity when needed. 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.

[0064] Taking electrochemical energy storage as an example, this application provides an energy storage device. The energy storage device is equipped with a set of energy storage batteries. It mainly uses the chemical elements in the 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, it stores the electrical energy generated by wind and solar energy 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.

[0065] 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:

[0066] 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 and frequency regulation.

[0067] ② Small and medium-sized energy storage cabinets used in commercial and industrial energy storage scenarios (banks, shopping malls, etc.) and small residential energy storage boxes used in residential energy storage scenarios primarily operate under the "peak shaving and valley filling" model. 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 hours and release the stored electricity during peak hours to save on costs. Furthermore, in remote areas and regions prone to natural disasters such as earthquakes and hurricanes, residential energy storage devices essentially provide backup power for users and the power grid, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0068] Please see Figure 1 , Figure 1 The energy storage system provided in one embodiment of this application is a structural schematic diagram of a residential energy storage system, and this application... Figure 1 The embodiments are illustrated using a home energy storage scenario in user-side energy storage as an example. The energy storage device provided in the embodiments of this application is not limited to the home energy storage scenario.

[0069] like Figure 1 As shown, the energy storage system 1000 provided in this embodiment includes an energy storage device 100, a power conversion device 200 (photovoltaic panel), a first user load 300 (streetlight), and a second user load 400 (e.g., household appliances such as air conditioners). The energy storage device 100 is a small energy storage box that can be wall-mounted to an outdoor wall. Specifically, the photovoltaic panel can convert solar energy into electrical energy during periods of low electricity prices, and the energy storage device 100 is used to store this electrical energy and supply it to streetlights and household appliances during peak electricity prices, or to provide power during power outages / power interruptions.

[0070] Please see Figure 2 , Figure 2 This is a schematic diagram of the structure of an energy storage system provided in another embodiment of this application, and this application Figure 2 The embodiments are illustrated using a shared energy storage scenario on the generation / distribution side as an example. The energy storage device 100 of this application is not limited to its generation / distribution side energy storage scenario.

[0071] like Figure 2As shown, the energy storage system 1000 provided in this application embodiment includes an energy storage device 100, a high-voltage cable 210, a first power conversion device 310, and a second power conversion device 410. During power generation, the first power conversion device 310 and the second power conversion device 410 convert other forms of energy into electrical energy, which is then connected to the high-voltage cable 210 and supplied to the power consumption side of the distribution network. When the power load is low and the first power conversion device 310 and the second power conversion device 410 generate excess power, the excess power is stored in the energy storage device 100, reducing wind and solar curtailment rates and improving the absorption of new energy power generation. When the power load is high, the power grid issues an instruction to transmit the power stored in the energy storage device 100 in conjunction with the high-voltage cable 210 in a grid-connected mode to supply power to the power consumption side, providing various services such as peak shaving, frequency regulation, and backup for power grid operation, fully leveraging the peak shaving function of the power grid, promoting peak shaving and valley filling, and alleviating the power supply pressure on the power grid.

[0072] Optionally, the first power conversion device 310 and the second power conversion device 410 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy and mechanical energy into electrical energy.

[0073] In this application, there can be multiple energy storage devices 100, which can be connected in series or in parallel. These multiple energy storage devices 100 are supported and electrically connected by an isolation plate (not shown). In this embodiment, "multiple" refers to two or more. An energy storage box can also be provided outside the energy storage device 100 to house it.

[0074] Optionally, the energy storage device 100 may include, but is not limited to, a single battery cell, a battery module, a battery pack, or a battery system. The actual application form of the energy storage device 100 provided in this application embodiment may be, but is not limited to, the listed products, and may also be other application forms. This application embodiment does not strictly limit the application form of the energy storage device 100. This application embodiment only uses a multi-cell battery as an example for illustration. When the energy storage device 100 is a single battery cell, it may be at least one of cylindrical batteries, prismatic batteries, etc.

[0075] To more conveniently illustrate the energy storage device 100 provided in the embodiments of this application, and as an example rather than a limitation, the technical solution of this application will be described in detail below with the example of the energy storage device 100 being a square battery.

[0076] Please see Figure 3 and Figure 4The energy storage device 100 provided in this application embodiment includes a housing 10, bare battery cells 20, and an end cap assembly 30. The housing 10 has an inner cavity 11 and an opening 12 communicating with the inner cavity 11. The bare battery cells 20 are built into the inner cavity 11, and the end cap assembly 30 is sealed at the opening 12 of the housing 10 to seal the bare battery cells 20 within the inner cavity 11 of the housing 10. There may be one or more bare battery cells 20. When there are multiple bare battery cells 20, they may be arranged along the length direction of the energy storage device 100, along the width direction of the energy storage device 100, or in an array along both the length and width directions of the energy storage device 100. Furthermore, the multiple bare battery cells 20 may be connected in series or in parallel, or some of the bare battery cells 20 may be connected in series and others in parallel.

[0077] Please see Figures 4 to 6 The end cap assembly 30 provided in this application embodiment includes an end cap plate 31. The end cap plate 31 is sealed at the opening 12 of the housing 10. The end cap plate 31 has a first surface 31a and a second surface 31b opposite to each other along its thickness direction. The first surface 31a is disposed away from the bare battery cell 20, and the second surface 31b is disposed towards the bare battery cell 20. The end cap plate 31 is provided with an injection hole 311 that penetrates the first surface 31a and the second surface 31b. Thus, the injection hole 311 can be connected to the inner cavity 11 of the housing 10, and electrolyte can be injected into the inner cavity 11 of the housing 10 through the injection hole 311 so that the bare battery cell 20 is immersed in the electrolyte to ensure the performance of the bare battery cell 20.

[0078] Optionally, the end cover plate 31 can be a metal plate (e.g., an aluminum plate) or a non-metal plate (e.g., a plastic plate, a silicone plate, a rubber plate, etc.). When the end cover plate is a metal plate, the end cover assembly 30 generally also includes a lower plastic layer, which is disposed on the second surface 31b of the end cover plate 31 to achieve insulation between the end cover plate 31 and the bare cell 20.

[0079] The energy storage device 100 provided in this application embodiment also includes a rubber nail 32 and a sealing plate 33. The rubber nail 32 passes through the injection hole 311, and the sealing plate 33 is located on the first surface 31a, covering the injection hole 311 and welded to the end cover plate 31. In actual operation, after filling with helium after injection, the rubber nail 32 is usually pressed into the injection hole 311 from the first surface 31a along the thickness direction of the end cover plate 31 to temporarily seal and block the injection hole 311. Then, the sealing plate 33 is placed on top, and the sealing plate 33 and the top cover plate are welded together along the edge of the sealing plate 33 to achieve a permanent seal. The sealing plate 33 can be a sealing metal sheet, such as a sealing aluminum sheet, a sealing aluminum alloy sheet, or a sealing copper sheet, etc., and the rubber nail 32 can be a plastic nail, a rubber nail, or a silicone nail, etc.

[0080] However, the inventors discovered through research that if the adhesive nail 32 is pressed into the injection hole 311 on the end cover plate 31 and squeezed tightly with the injection hole 311, that is, the adhesive nail 32 and the injection hole 311 are in an interference fit, even if there is a problem of abnormal welding between the sealing plate 33 and the injection hole 311 (such as a leak), the interference fit between the adhesive nail 32 and the injection hole 311 will make it difficult for the helium inside the housing 10 to overflow from the joint between the adhesive nail 32 and the injection hole 311 to the welding position between the sealing plate 33 and the injection hole 311 in a timely manner. This will affect the accuracy of the helium detection process and make it difficult to detect abnormal welding of the sealing plate 33 in the energy storage device 100.

[0081] In view of this, combined with Figures 7 to 9 As shown, the adhesive nail 32 in this application includes a columnar portion 321 and an end portion 322 connected along the thickness direction. The columnar portion 321 passes through the injection hole 311, and a first channel 3211 is formed between the outer peripheral surface of the columnar portion 321 and the hole wall surface of the injection hole 311. The radial dimension of the end portion 322 is larger than the radial dimension of the columnar portion 321, and the radial dimension of the end portion 322 is larger than the radial dimension of the injection hole 311, so as to construct a stepped surface 323. Both the end portion 322 and the stepped surface 323 are located outside the injection hole 311, and both the end portion 322 and the stepped surface 323 are located on the side of the second surface 31b away from the first surface 31a, that is, the end portion 322... Both section 322 and step surface 323 are located on the side where the second surface 31b is located. A second channel 3231 is formed between the step surface 323 and the second surface 31b. The second channel 3231 is connected to the first channel 3211 and the inner cavity of the shell, so that the helium gas injected into the inner cavity of the shell can be discharged sequentially through the second channel 3231 and the first channel 3211 to the welding joint of the sealing sheet 33 and the end cover plate 31. In subsequent helium gas detection, it is possible to accurately detect whether the sealing sheet 33 is welded well, thereby avoiding the problem of poor sealing effect caused by poor welding of the sealing sheet 33. This can effectively ensure the safety, sealing and stability of the energy storage device.

[0082] In the above-mentioned solution, the inventors also discovered through research that, due to the presence of the first channel 3211 and the second channel 3231, during the welding process of the sealing metal sheet, welding slag, metal spatter, etc., can easily fall into the inner cavity of the shell through the helium gas channel. This can not only cause short circuits in the bare cells and pose a safety hazard, but also contaminate the electrolyte and affect the battery performance.

[0083] Therefore, as Figure 10 and Figure 11As shown, based on the above-mentioned solution, this application further forms a recessed portion 324 in the step surface 323 in the direction away from the second surface 31b, and the recessed portion 324 is connected to the first channel 3211. Thus, when the sealing sheet 33 is welded to the end cover plate 31, the recessed portion 324 can collect impurities such as welding slag and metal shavings that enter through the first channel 3211. That is, when the sealing sheet 33 is welded to the end cover plate 31, the welding slag and metal shavings that splash out pass through the second channel 3231 and fall into the recessed portion 324 through the first channel 3211 and are collected by the recessed portion 324. This prevents the welding slag and metal shavings from scattering around and falling into the cell, thereby reducing the probability that the welding slag and metal shavings that splash out when the sealing sheet 33 is welded to the end cover plate 31 will enter the inner cavity of the casing through the second channel 3231. This reduces the probability of short circuit of the bare cell and contamination of the electrolyte, thereby improving the battery performance and safety of the energy storage device.

[0084] In summary, by adopting the technical solution provided in this application, it is possible to reduce the probability of welding slag, metal spatter, etc. falling into the inner cavity of the casing while ensuring the welding sealing performance of the sealing sheet through helium testing, thereby ensuring the battery performance and safety of the energy storage device.

[0085] It is worth noting that, such as Figure 12 As shown, immediately after helium charging is completed, the adhesive pin 32 is pressed into the injection hole 311, with the end 322 of the adhesive pin 32 positioned within the injection hole 311, to temporarily seal it and prevent electrolyte and helium from overflowing from the injection hole 311. Specifically, as... Figure 12 and Figure 13As shown, when the adhesive nail 32 is pressed into the injection hole 311 until the end 322 is located in the injection hole 311, since the radial dimension of the end 322 is larger than the radial dimension of the injection hole 311, the end 322 is interference-fitted into the injection hole 311, and the end 322 and the injection hole 311 are interference-fitted. At this time, the second channel 3231 is not formed between the stepped surface 323 and the second surface 31b, so the first channel 3211 is not connected to the inner cavity of the shell. Alternatively, the second channel 3231 is blocked by the outer peripheral side surface 3222 of the end 322 or the hole wall surface of the injection hole 311, so the first channel 3211 cannot connect to the inner cavity of the shell through the second channel 3231, thereby achieving a tight seal. The sealing effect of the injection hole 311 is to prevent electrolyte overflow and to prevent helium from escaping from the second channel 3231 and the first channel 3211 to the outside of the casing, which would result in an excessively low helium concentration. In other words, after helium filling, during the process of moving the energy storage device to the welding equipment to weld the sealing plate 33, a large amount of helium is prevented from being released, which would result in an excessively low helium concentration. This ensures that there is enough helium to be discharged through the second channel 3231 and the first channel 3211 to the weld between the sealing plate 33 and the end cover plate 31 during subsequent helium testing, thereby improving the detectability of subsequent helium testing. This, in turn, helps to improve the accuracy of the helium testing process and facilitates the detection of energy storage devices with abnormal welding of the sealing plate 33.

[0086] After the energy storage device is moved to the welding equipment, the adhesive nail 32 is pressed into the injection hole 311 along the thickness direction of the end cover plate 31. Then, the sealing sheet 33 is immediately welded to the end cover plate 31. At this time, the end 322 is no longer located in the injection hole 311, but outside the injection hole 311, and the stepped surface 323 is also located in the injection hole 311. A second channel 3231 is formed between the stepped surface 323 and the second surface 31b. The second channel 3231 is connected to the first channel 3211 and the inner cavity of the shell, so that the helium gas injected into the inner cavity of the shell can be discharged sequentially through the second channel 3231 and the first channel 3211 to the welding point of the sealing sheet 33 and the end cover plate 31. In subsequent helium gas detection, it is possible to accurately detect whether the sealing sheet 33 is welded well, thereby avoiding the problem of poor sealing effect caused by poor welding of the sealing sheet 33. This can effectively ensure the safety, sealing and stability of the energy storage device.

[0087] Optionally, the recess 324 in this embodiment can be an arc-shaped groove with an arc-shaped inner surface. It is understood that in other embodiments, the recess 324 can also be a groove of other shapes.

[0088] In some embodiments, for ease of description, the radial dimension of the injection hole 311 is configured as d1, and the radial dimension of the end portion 322 is configured as d2, wherein 1.02 ≤ d2 / d1 = 1.12, for example, d2 / d1 = 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.10, 1.11, or 1.12, etc. For example, when the radial dimension d1 of the injection hole 311 is 3.0 mm, the radial dimension d2 of the end portion 322 can be 3.15 mm.

[0089] By ensuring that the ratio of the radial dimension d1 of the injection hole 311 to the radial dimension d2 of the end 322 satisfies the above relationship, it is possible to ensure the temporary sealing performance by allowing the end 322 to be pressurized with the injection hole 311, while avoiding excessive interference between the end 322 and the injection hole 311. This makes it easier for the end 322 to pass through the injection hole 311 when pressure is applied to the glue nail 32, thereby reducing the difficulty of pressing the glue nail 32 into the injection hole 311 further along the thickness direction of the end cover plate 31.

[0090] Furthermore, such as Figure 12 and Figure 13 As shown, the end portion 322 has an end face 3221 and an outer peripheral side face 3222. The end face 3221 is disposed away from the sealing sheet 33, and the outer peripheral side face 3222 is connected between the end face 3221 and the stepped surface 323. A chamfer 3223, such as a chamfer or a rounded corner, is formed at the connection between the outer peripheral side face 3222 and the end face 3221. In this way, when the rubber nail 32 is pressed into the injection hole 311, the chamfer 3223 can be used to guide it, thereby helping to improve the problem of difficulty in pressing the rubber nail 32 into the injection hole 311 due to interference between the end portion 322 of the rubber nail 32 and the injection hole 311. This helps to ensure that the rubber nail 32 can be smoothly pressed into the injection hole 311, and the end portion 322 can also smoothly pass through the injection hole 311 and be located outside the injection hole 311.

[0091] In some embodiments, the injection hole 311 may include a first hole segment 311a and a second hole segment 311b connected in the thickness direction of the end cap plate 31. The first hole segment 311a penetrates the first surface 31a, and the second hole segment penetrates the second surface 31b. The radial dimension of the second hole segment 311b is smaller than that of the first hole segment 311a, forming a stepped surface 311c. The columnar portion 321 of the adhesive nail 32 passes through the second hole segment 311b, and the radial dimension of the end portion 322 is larger than that of the second hole segment 311b. Both the end portion 322 and the stepped surface 323 are located outside the second hole segment 311b. The sealing piece 33 is disposed in the first hole segment 311a and abuts against the stepped surface 311c. On the one hand, this allows the sealing sheet 33 to remain flush with the first surface 31a, or to be concealed within the first hole segment 311a without protruding from the first surface 31a, thereby preventing accidental contact with the sealing sheet 33 that could loosen it and affect the sealing effect. On the other hand, the first hole segment 311a can be used to define the installation position of the sealing sheet 33, providing a certain positioning and limiting effect for its installation, making it easier to install the sealing sheet 33 to the preset position.

[0092] In some embodiments, the adhesive pin 32 can be integrally formed with the sealing sheet 33. For example, the adhesive pin 32 and the sealing sheet 33 can be formed into a whole through a secondary injection molding process. In this way, on the one hand, the sealing sheet 33 can be pressed into the injection hole 311 together with the adhesive pin 32, thereby eliminating the original sealing sheet 33 placement process. Specifically, the sealing sheet 33 placement, alignment and CCD positioning processes can be eliminated, which can greatly simplify the process steps and reduce the process difficulty. On the other hand, the reliability between the adhesive pin 32 and the sealing sheet 33 can be guaranteed.

[0093] Of course, it is understandable that the adhesive nail 32 and the sealing plate 33 can also be formed into an integral structure in other ways, such as by snap-fit ​​or plug-in.

[0094] Among them, CCD (Charge-Coupled Device) is a photoelectric conversion element widely used in optical devices such as digital cameras, camcorders, and scanners. It mainly achieves precise positioning of objects by converting and processing light signals.

[0095] Optionally, the sealing sheet 33, the column portion 321, and the end portion 322 are coaxially arranged. With this design, due to the interference fit between the end portion 322 of the adhesive pin 32 and the injection hole 311, the adhesive pin 32 and the injection hole 311 are coaxially arranged. Thus, after the sealing sheet 33 is pressed into the injection hole 311 along with the adhesive pin 32, it can also maintain a good concentricity relationship with the injection hole 311. This achieves the positioning function of the sealing sheet 33, so that the sealing sheet 33 does not need to be positioned or straightened by an external robot. It can be pushed in and assembled into place by applying a force along the thickness direction of the end cover plate 31. This can greatly simplify the assembly steps of the sealing sheet 33 and reduce the assembly difficulty of the sealing sheet 33.

[0096] In some embodiments, the sealing sheet 33 has a third surface 331 facing the column portion 321, and the column portion 321 has a fourth surface 3212 facing the sealing sheet 33. One of the third surface 331 and the fourth surface 3212 is provided with a connecting protrusion 332, and the other of the third surface 331 and the fourth surface 3212 is provided with a connecting groove 3213. The connecting protrusion 332 is embedded in the connecting groove 3213 to facilitate the connection between the sealing sheet 33 and the adhesive nail 32. The connection protrusion 332 and the connecting groove 3213 can also be used to position the sealing sheet 33 and the column portion 321, thereby facilitating the coaxial arrangement of the sealing sheet 33, the column portion 321 and the end portion 322.

[0097] When the third surface 331 has a connecting protrusion 332 and the fourth surface 3212 has a connecting groove 3213, the outer peripheral surface of the connecting protrusion 332 is gradually inclined towards the central axis of the connecting protrusion 332 in a direction away from the third surface 331 (i.e., upward). In this case, the connecting protrusion 332 is a gourd shape, wider at the top and narrower at the bottom, and the inclination angle of its outer peripheral surface is α1. Correspondingly, the groove wall of the connecting groove 3213 is gradually inclined away from the central axis of the connecting groove 3213 in a direction away from the bottom surface of the connecting groove 3213 (i.e., upward). In this case, the connecting groove 3213 is a trumpet-shaped groove, wider at the top and narrower at the bottom, and the inclination angle of its groove wall is α2. Since the material of the plastic nail 32 is mainly elastic materials such as plastic, rubber or silicone, it is mainly formed by injection molding. Therefore, the connecting groove 3213 is also mainly formed by injection molding. Thus, the inclination angle of the groove wall of the connecting groove 3213, α2, can also be understood as the draft angle of the groove wall of the connecting groove 3213.

[0098] When the third surface 331 has a connecting protrusion 332 and the fourth surface 3212 has a connecting groove 3213, the groove wall of the connecting groove 3213 is gradually inclined away from the central axis of the connecting groove 3213 in a direction away from the bottom surface of the connecting groove 3213 (i.e., downward). In this case, the connecting groove 3213 is a funnel-shaped groove with a smaller top and a larger bottom, and the inclination angle of the groove wall is α2. Correspondingly, the outer peripheral surface of the connecting protrusion 332 is gradually inclined towards the central axis of the connecting protrusion 332 in a direction away from the fourth surface 3212 (i.e., downward). In this case, the connecting protrusion 332 is a gourd-shaped shape with a smaller top and a larger bottom, and the inclination angle of the outer peripheral surface of the connecting protrusion 332 is α1. Since the material of the plastic nail 32 is mainly elastic materials such as plastic, rubber or silicone, it is mainly formed by injection molding. Therefore, the connecting protrusion 332 is also mainly formed by injection molding. Thus, the inclination angle α2 of the outer peripheral surface of the connecting protrusion 332 can also be understood as the draft angle of the outer peripheral surface of the connecting protrusion 332.

[0099] In some alternative embodiments, 0° < |α1-α2| ≤ 1°, and |α1-α2| = 0.1°, 0.15°, 0.2°, 0.25°, 0.3°, 0.35°, 0.4°, 0.45°, 0.5°, 0.55°, 0.6°, 0.65°, 0.7°, 0.75°, 0.8°, 0.85°, 0.9°, 0.95°, or 1°. When the relationship 0°<|α1-α2|≤1° is satisfied, it means that the inclination angle α1 of the outer peripheral surface of the connecting protrusion 332 and the inclination angle α2 of the groove wall surface of the connecting groove 3213 are different. By making the inclination angle α1 of the outer peripheral surface of the connecting protrusion 332 and the inclination angle α2 of the groove wall surface of the connecting groove 3213 different, they can form an interference fit, which is beneficial to achieving the tight fit between the connecting protrusion 332 and the connecting groove 3213 and improving the connection stability of the sealing plate 33 and the rubber nail 32.

[0100] In some embodiments, such as Figures 11 to 13 As shown, the radial dimension of the column portion 321 is smaller than the radial dimension of the injection hole 311, so that a gap is formed between the outer peripheral surface of the column portion 321 and the hole wall surface of the injection hole 311. This gap communicates with the recessed portion 324, and the column portion 321 is connected to the sealing plate 33 to prevent the glue pin 32 from detaching from the injection hole 311 along the direction towards the bare cell and falling into the inner cavity of the housing; wherein, this gap constitutes the first channel 3211. The above method of forming the first channel 3211, compared with the method of fitting the outer peripheral surface of the column portion 321 and the hole wall surface of the injection hole 311 and forming the first channel 3211 by opening a groove on the outer peripheral surface of the column portion 321 and / or the hole wall surface of the injection hole 311, makes the formation of the first channel 3211 simpler, and simplifies the structure of the glue pin 32 and the end cover plate 31, and simplifies the processing technology of the glue pin 32 and the end cover plate 31.

[0101] As an optional implementation method, such as Figure 11 As shown, where, Figure 11 The bold dashed line roughly illustrates the flow path of helium gas. A gap can be formed between the stepped surface 323 and the second surface 31b, which communicates with the first channel 3211 and constitutes the second channel 3231. This eliminates the need for grooves in the end 322 and / or end cap 31 to form the second channel 3231, thus simplifying its formation and reducing the complexity of the adhesive pin 32 and end cap 31, as well as their manufacturing process.

[0102] In this embodiment, after helium filling is completed, the adhesive nail 32 is immediately pressed into the injection hole 311, and the end 322 of the adhesive nail 32 is located in the injection hole 311 for temporary sealing. When this is done, no second channel 3231 is formed between the step surface 323 and the second surface 31b, and the first channel 3211 is not connected to the inner cavity of the shell. This allows the energy storage device to be moved to the welding equipment to weld the sealing sheet 33 after helium filling, thus avoiding the release of a large amount of helium that would result in a low helium concentration. This ensures that sufficient helium is discharged through the second channel 3231 and the first channel 3211 to the weld between the sealing sheet 33 and the end cover plate 31 during subsequent helium testing, improving the detectability of subsequent helium testing. This, in turn, helps to improve the accuracy of the helium testing process and facilitates the detection of energy storage devices with abnormal welding of the sealing sheet 33.

[0103] As another optional implementation method, combined with Figures 13 to 16 As shown, the stepped surface 323 abuts against the second surface 31b, thus preventing the glue pin 32 from detaching from the injection hole 311 in a direction away from the bare cell. A first groove 325 is provided on the outer periphery of the stepped surface 323, and / or a second groove 312 is provided on the periphery of the second surface 31b near the injection hole 311; the first groove 325 and / or the second groove 312 communicate with the first channel 3211 and / or the recess 324, and the first groove 325 and / or the second groove 312 communicate with the inner cavity of the shell, so that the helium gas injected into the inner cavity of the shell can be discharged sequentially through the second channel 3231 and the first channel 3211 to the welding point of the sealing sheet 33 and the end cover plate 31; wherein, the first groove 325 and / or the second groove 312 constitute the second channel 3231.

[0104] Through the above design, the stepped surface 323 and the second surface 31b can be stopped to prevent the helium from dislodging from the injection hole 311 along the direction away from the bare cell along the glue nail 32. At the same time, the helium gas injected into the inner cavity of the housing can be discharged to the weld between the sealing sheet 33 and the end cover plate 31 so that the sealing sheet 33 can be accurately detected as well as well as well during subsequent helium gas detection. This avoids the problem of poor sealing effect caused by poor welding of the sealing sheet 33, thereby effectively ensuring the safety, sealing and stability of the energy storage device.

[0105] In this embodiment, after helium filling is completed, the adhesive nail 32 is immediately pressed into the injection hole 311, and the end 322 of the adhesive nail 32 is located in the injection hole 311 for temporary sealing. When the second channel 3231 is blocked by the outer peripheral side 3222 of the end 322 or the hole wall of the injection hole 311, the first channel 3211 cannot communicate with the inner cavity of the shell through the second channel 3231. Thus, after helium filling is completed, when the energy storage device is moved to the welding equipment for welding the sealing sheet 33, a large amount of helium gas is not released, resulting in a low helium concentration. This ensures that there is enough helium gas to be discharged through the second channel 3231 and the first channel 3211 to the welding joint of the sealing sheet 33 and the end cover plate 31 during subsequent helium gas detection, thereby improving the detectability during subsequent helium gas detection and improving the accuracy of the helium gas detection process. This also helps to detect energy storage devices with abnormal welding of the sealing sheet 33.

[0106] An example, such as Figure 14 As shown, a first groove 325 is provided on the outer periphery of the stepped surface 323. The first groove 325 penetrates the inner wall of the recessed portion 324 to communicate with the first channel 3211 through the recessed portion 324. The first groove 325 also penetrates the outer peripheral side surface 3222 of the end 322 to communicate with the inner cavity 11 of the housing 10. The first groove 325 constitutes the second channel 3231. This allows the helium gas injected into the inner cavity 11 of the housing 10 to enter the first groove 325 from the inlet of the first groove 325 penetrating the outer peripheral side surface 3222 of the end 322, and flow into the recessed portion 324 and the first channel 3211 from the outlet of the first groove 325 penetrating the inner wall of the recessed portion 324, so as to be discharged to the welding point of the sealing plate 33 and the end cover plate 31 (wherein, Figure 14 The bold dashed line in the image roughly shows the flow path of helium gas. This allows for accurate detection of whether the sealing sheet 33 is properly welded during subsequent helium gas testing, thus avoiding poor sealing performance due to poor welding of the sealing sheet 33. This effectively ensures the safety, sealing performance, and stability of the energy storage device 100.

[0107] Another example, such as Figure 15As shown, a second groove 312 is provided on the periphery of the second surface 31b near the injection hole 311. The second groove 312 penetrates the groove wall of the injection hole 311 to communicate with the first channel 3211, and a portion of the second groove 312 is exposed at the end 322 to communicate with the inner cavity 11 of the housing 10. The second groove 312 constitutes the second channel 3231. This allows the helium gas injected into the inner cavity 11 of the housing 10 to enter the second groove 312 from the inlet formed by the groove portion of the second groove 312 exposed at the end 322, and flow into the first channel 3211 from the outlet of the second groove 312 penetrating the groove wall of the injection hole 311, so as to be discharged to the welding point of the sealing plate 33 and the end cover plate 31 (wherein, Figure 15 The bold dashed line in the image roughly shows the flow path of helium gas. This allows for accurate detection of whether the sealing sheet 33 is properly welded during subsequent helium gas testing, thus avoiding poor sealing performance due to poor welding of the sealing sheet 33. This effectively ensures the safety, sealing performance, and stability of the energy storage device 100.

[0108] Another example, such as Figure 16 As shown, a first groove 325 is provided on the outer periphery of the stepped surface 323, and a second groove 312 is provided on the periphery of the second surface 31b near the injection hole 311. The second groove 312 is provided corresponding to the first groove 325, and the openings of the second groove 312 and the first groove 325 face each other and communicate with each other. The first groove 325 penetrates the inner wall of the recessed portion 324 to communicate with the first channel 3211 through the recessed portion 324. The first groove 325 also penetrates the outer peripheral side of the end 322 to communicate with the inner cavity of the shell. The second groove 312 penetrates the groove wall of the injection hole 311 to communicate with the first channel 3211, and a portion of the second groove 312 is exposed at the end 322 to communicate with the inner cavity of the shell. The first groove 325 and the second groove 312 constitute the second channel 3231.

[0109] By adopting the above design, compared with the method of only setting the first groove 325 on the outer periphery of the step surface 323 or only setting the second groove 312 on the periphery of the second surface 31b near the injection hole 311, a second channel 3231 with a relatively large diameter can be provided, which increases the flow rate of helium gas and ensures that enough helium gas is discharged to the weld between the sealing sheet 33 and the end cover plate 31. This is beneficial to improving the detectability of subsequent helium gas detection, thereby improving the accuracy of the helium gas detection process and facilitating the detection of abnormal welding of the sealing sheet 33 in the energy storage device 100.

[0110] In some embodiments, such as Figure 17As shown, there can be multiple second channels 3231, such as two, three, four, five, six, seven, or eight, arranged at intervals. Compared to a single second channel 3231 with a larger diameter, having multiple second channels 3231 arranged at intervals creates a structure similar to a brush or brush surface. This increases the flow rate of helium gas while preventing welding slag, metal shavings, etc., from falling into the inner cavity of the casing through the second channels 3231. This reduces the probability of short circuits in the bare cells and electrolyte contamination, thereby improving the battery performance and safety of the energy storage device.

[0111] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] Furthermore, the embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the content of this specification should not be construed as a limitation of this application, and the protection scope of this application should be determined by the appended claims.

Claims

1. An energy storage device, characterized by, The energy storage device (100) comprises: a housing (10) having an inner cavity (11) and an opening (12) communicating with the inner cavity (11); a bare electric core (20) built in the inner cavity (11); an end cover assembly (30) comprising an end cover plate (31) sealingly arranged at the opening (12), the end cover plate (31) having a first surface (31a) and a second surface (31b) opposite along the thickness direction thereof, the first surface (31a) being arranged away from the bare electric core (20), and the end cover plate (31) being provided with a liquid injection hole (311) penetrating through the first surface (31a) and the second surface (31b); a glue pin (32) penetrating through the liquid injection hole (311); and a sealing sheet (33) located at the first surface (31a) and sealingly covering the liquid injection hole (311) and being welded with the end cover plate (31); wherein the glue pin (32) comprises a columnar portion (321) and an end portion (322) connected along the thickness direction, the columnar portion (321) penetrating through the liquid injection hole (311), and a first channel (3211) being formed between the outer peripheral surface of the columnar portion (321) and the hole wall surface of the liquid injection hole (311), the radial dimension of the end portion (322) being greater than the radial dimension of the liquid injection hole (311) to form a step surface (323), the end portion (322) and the step surface (323) being located on the side of the second surface (31b) away from the first surface (31a), and a second channel (3231) being formed between the step surface (323) and the second surface (31b) and communicating the first channel (3211) and the inner cavity (11) of the housing (10).

2. The energy storage device of claim 1, wherein, The step surface (323) is concave inwards in the direction away from the second surface (31b) to form a recessed portion (324) communicating with the first channel (3211).

3. The energy storage device of claim 2, wherein, The step surface (323) abuts against the second surface (31b), the step surface (323) is provided with a first groove (325) at the outer peripheral edge thereof, and / or the second surface (31b) is provided with a second groove (312) at the peripheral edge thereof close to the liquid injection hole (311); the first groove (325) and / or the second groove (312) communicate with the first channel (3211) and / or the recessed portion (324), and the first groove (325) and / or the second groove (312) communicate with the inner cavity (11) of the housing (10); wherein the first groove (325) and / or the second groove (312) constitute the second channel (3231).

4. The energy storage device of claim 3, wherein, The outer periphery of the stepped surface (323) is provided with the first groove (325), and the second surface (31b) is provided with the second groove (312) near the periphery of the liquid injection hole (311), the second groove (312) is arranged corresponding to the first groove (325), and the groove opening of the second groove (312) and the groove opening of the first groove (325) face each other and communicate with each other; 5. The energy storage device of claim 3, wherein, The outer periphery of the stepped surface (323) is provided with the first groove (325), and the second surface (31b) is provided with the second groove (312) near the periphery of the liquid injection hole (311), the second groove (312) is arranged corresponding to the first groove (325), and the groove opening of the second groove (312) and the groove opening of the first groove (325) face each other and communicate with each other; 6. The energy storage device of claim 3, wherein, The outer periphery of the stepped surface (323) is provided with the first groove (325), and the second surface (31b) is provided with the second groove (312) near the periphery of the liquid injection hole (311), the second groove (312) is arranged corresponding to the first groove (325), and the groove opening of the second groove (312) and the groove opening of the first groove (325) face each other and communicate with each other; The outer periphery of the stepped surface (323) is provided with the first groove (325), and the second surface (31b) is provided with the second groove (312) near the periphery of the liquid injection hole (311), the second groove (312) is arranged corresponding to the first groove (325), and the groove opening of the second groove (312) and the groove opening of the first groove (325) face each other and communicate with each other; The outer periphery of the stepped surface (323) is provided with the first groove (325), and the second surface (31b) is provided with the second groove (312) near the periphery of the liquid injection hole (311), the second groove (312) is arranged corresponding to the first groove (325), and the groove opening of the second groove (312) and the groove opening of the first groove (325) face each other and communicate with each other; The first groove (325) and the second groove (312) constitute the second channel (3231).

7. The energy storage device of claim 2, wherein, The second channel (3231) is a plurality of second channels (3231) arranged at intervals.

8. The energy storage device of claim 2, wherein, The stepped surface (323) and the second surface (31b) are arranged at intervals to form a gap, and the gap communicates with the first channel (3211); The gap constitutes the second channel (3231).

9. The energy storage device of any one of claims 1-8, wherein, The radial dimension of the columnar portion (321) is smaller than the radial dimension of the liquid injection hole (311), so that a gap is formed between the outer peripheral surface of the columnar portion (321) and the hole wall surface of the liquid injection hole (311), the gap communicates with the recessed portion, and the columnar portion (321) is connected with the sealing sheet (33); The gap constitutes the first channel (3211).

10. The energy storage device of any one of claims 1-8, wherein, The radial dimension of the liquid injection hole (311) is d1, and the radial dimension of the end portion (322) is d2, wherein 1.02≤d2 / d1=1.

12.

11. The energy storage device of any one of claims 1-8, wherein, The end portion (322) has an end face (3221) arranged away from the sealing sheet (33) and an outer peripheral side face (3222) connected between the end face (3221) and the step face (323), and a chamfer is formed at the connection between the outer peripheral side face (3222) and the end face (3221).

12. The energy storage device of any one of claims 1-8, wherein, The glue nail (32) is arranged integrally with the sealing sheet (33).

13. The energy storage device of claim 12, wherein, The sealing sheet (33), the columnar portion (321), and the end portion (322) are coaxially arranged.

14. The energy storage device of any one of claims 1-8, wherein, The sealing sheet (33) has a third surface (331) arranged toward the columnar portion (321), the columnar portion (321) has a fourth surface (3212) arranged toward the sealing sheet (33), one of the third surface (331) and the fourth surface (3212) is provided with a connecting protrusion (332), and the other of the third surface (331) and the fourth surface (3212) is provided with a connecting groove (3213), the connecting protrusion (332) is embedded in the connecting groove (3213). The outer peripheral surface of the connecting protrusion (332) is gradually inclined toward the central axis of the connecting protrusion (332) in a direction away from the third surface (331) or the fourth surface (3212), the inclination angle of the outer peripheral surface of the connecting protrusion (332) is α1, the groove wall surface of the connecting groove (3213) is gradually inclined away from the central axis of the connecting groove (3213) in a direction away from the groove bottom surface of the connecting groove (3213), the inclination angle of the groove wall surface of the connecting groove (3213) is α2, and wherein 0°<|α1-α2|≤1°.

15. An energy storage system characterized by, The energy storage system has the energy storage device (100) according to any one of claims 1-14.

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