End cap assemblies, energy storage devices and electrical equipment

Abstract

This application discloses an end cap assembly, an energy storage device, and an electrical device, relating to the field of energy storage technology. The end cap assembly includes: a cover plate with a through mounting hole; an electrode terminal including an electrode post and a welding ring, the electrode post passing through the mounting hole, a first end of the electrode post being positioned on a first surface side of the cover plate, and the welding ring located on a second surface side of the cover plate and sleeved on the second end of the electrode post; the end face edge of the second end of the electrode post has a welding notch, the inner wall of the welding ring has a welding protrusion, and the weld seam formed by the welding notch and the welding protrusion has a first weld opening and a second weld opening. In the thickness direction of the cover plate, the second weld opening is located between the first weld opening and the cover plate, and the orthographic projection of the first weld opening on the cover plate is located within the area enclosed by the inner edge of the orthographic projection of the second weld opening on the cover plate. In this embodiment, by adjusting the shape of the weld seam, the airtightness of the weld seam after welding can be improved, thereby increasing the production yield.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and more specifically, to an end cap assembly, an energy storage device, and an electrical appliance. Background Technology

[0002] A rechargeable battery, also known as a secondary battery or storage battery, is a battery that can be recharged after being discharged 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, people are also placing higher demands on their performance in various aspects, especially their lifespan.

[0003] In related technologies, secondary batteries typically consist of an end cap assembly, an electrode assembly, and a housing. The actual production process involves fabricating the end cap assembly, electrode assembly, and housing separately. Then, metal adapters are used to weld the electrode posts of the end cap assembly and the tabs of the electrode assembly together. The electrode assembly is then placed inside the housing, and the end cap assembly is used to close the opening of the housing and welded shut to form the basic structure of the secondary battery. Afterward, electrolyte is manually injected through injection holes located on the end cap assembly, and these injection holes are then welded shut to seal the battery.

[0004] The end cap assembly includes a cover plate and electrode posts, with the electrode posts being sealed through the cover plate. However, during the assembly of the secondary battery, it was found that poor sealing was prone to occur between the electrode posts and the cover plate, thereby reducing the production yield of the secondary battery. Summary of the Invention

[0005] A primary objective of this application is to provide an end cap assembly, energy storage device, and electrical equipment that facilitates improved airtightness and thus increased production yield.

[0006] To achieve the above-mentioned objectives, this application adopts the following technical solution:

[0007] According to one aspect of this application, an end cap assembly is provided, comprising: a cover plate having a first surface and a second surface facing away from each other, and a mounting hole extending from the first surface to the second surface; an electrode terminal including an electrode post and a welding ring, the electrode post passing through the mounting hole and a first end of the electrode post being limited to the first surface side of the cover plate, the welding ring being located on the second surface side of the cover plate and sleeved on the second end of the electrode post; the end face edge of the second end of the electrode post having a welding notch, the inner wall of the welding ring having a welding protrusion, the welding protrusion being located within the welding notch, and the inner wall of the welding notch and the surface of the welding protrusion forming a weld seam; the weld seam having a first weld opening and a second weld opening distributed in the thickness direction of the cover plate, the first weld opening and the second weld opening being both annular, and the second weld opening being located between the first weld opening and the cover plate, the orthographic projection of the first weld opening on the cover plate being located within the area enclosed by the inner edge of the orthographic projection of the second weld opening on the cover plate.

[0008] In this embodiment, the orthographic projection of the first weld opening on the cover plate is located within the area enclosed by the orthographic projection of the second weld opening on the cover plate. This allows the weld to bend in the thickness direction of the cover plate. When welding the weld, a seam weld effect can be formed near the first weld opening, and a through weld effect can be formed near the second weld opening. In addition, the bent weld can block the heat generated by welding between the first and second weld openings, so that the heat is mainly concentrated near the first weld opening and the heat accumulation at the second weld opening is reduced. This helps to ensure the stability of the welding keyhole at the second weld opening, thereby avoiding the phenomenon of welding pinholes and welding bursts near the second weld opening. This ensures the reliability of the sealing welding of the weld near the second weld opening, which in turn ensures the reliability of the sealing assembly of the electrode post on the cover plate.

[0009] According to one embodiment of this application, the inner wall generatrix of the welding notch is an arc-shaped curve that protrudes away from the welding ring.

[0010] In this embodiment, based on the inner wall shape of the welding notch, the orthographic projection of the first weld opening on the cover plate is ensured to be within the area enclosed by the orthographic projection of the second weld opening on the cover plate. At the same time, it is only necessary to ensure the fit between the inner wall of the welding notch and the surface of the welding protrusion in the thickness direction of the cover plate, thereby facilitating the formation of a small gap weld seam to ensure the stability of the molten pool during welding.

[0011] According to one embodiment of this application, the inner wall generatrix of the welding notch is an arc-shaped curve, and the corresponding central angle is greater than or equal to 90 degrees and less than or equal to 135 degrees.

[0012] In this embodiment, by setting the central angle corresponding to the inner wall generatrix of the welding notch, it is convenient to realize the assembly limit of the welding protrusion on the welding ring within the welding notch, thereby improving the assembly efficiency of the welding ring.

[0013] According to one embodiment of this application, the inner wall of the weld notch has a plurality of annular protrusions spaced apart in the direction from the first weld opening to the second weld opening.

[0014] In this embodiment, the wavy or sawtooth structure facilitates increasing the weld seam path in the direction from the first weld seam to the second weld seam, thereby reducing the accumulation of heat near the second weld seam and improving the stability of the welding keyhole near the second weld seam.

[0015] According to one embodiment of this application, the inner wall busbar of the welding notch is a bent line and includes a first busbar segment and a second busbar segment; the weld segment corresponding to the first busbar segment extends to the end face of the second end of the electrode post, and the first included angle formed by the first busbar segment and the second busbar segment is greater than or equal to 90 degrees and less than or equal to 135 degrees.

[0016] In this embodiment, based on the inner wall shape of the weld notch, the orthographic projection of the first weld opening on the cover plate is ensured to be within the area enclosed by the orthographic projection of the second weld opening on the cover plate. At the same time, a straight bend is achieved between the second busbar segment and the first busbar segment, thereby effectively reducing the accumulation of heat near the second weld opening and improving the stability of the welding keyhole near the second weld opening in the weld.

[0017] According to one embodiment of this application, the endpoint of the first busbar segment near the first weld joint is inclined in a direction away from the weld ring, and the second included angle formed by the length direction of the first busbar segment and the thickness direction of the cover plate is less than or equal to 45 degrees.

[0018] In this embodiment, it is easy to ensure the effective accumulation of heat in the first weld segment, thereby reducing the heat accumulated near the second weld joint and ensuring the stability of the welding keyhole near the second weld joint within the weld.

[0019] According to one embodiment of this application, the third angle formed by the length direction of the second busbar segment and the thickness direction of the cover plate is greater than or equal to 45 degrees and less than or equal to 90 degrees.

[0020] In this embodiment, it is easy to ensure the effective accumulation of heat in the first weld segment, thereby reducing the heat accumulated near the second weld joint and ensuring the stability of the welding keyhole near the second weld joint within the weld.

[0021] According to one embodiment of this application, the gap width of the weld seam is less than or equal to 0.1 mm.

[0022] In this embodiment, the stability of the molten pool can be ensured during welding by setting a small spacing, which in turn ensures the reliability of the welding ring and the electrode post.

[0023] According to one embodiment of this application, in the thickness direction of the cover plate, the root dimension of the welding protrusion is greater than or equal to 0.5 mm and less than or equal to 1 mm.

[0024] In this embodiment, by setting the root size of the welding protrusion, cracks are avoided at the root of the welding protrusion during welding, thereby ensuring the stability of the welding ring and the electrode post.

[0025] According to one aspect of this application, an energy storage device is provided, comprising: a housing including a receiving cavity with an opening; an electrode assembly housed within the receiving cavity; and an end cap assembly as described in the preceding aspect, the end cap assembly sealing the opening of the receiving cavity.

[0026] According to one aspect of this application, an electrical device is provided, the electrical device including the energy storage device described in the above aspect, the energy storage device supplying power to the electrical device.

[0027] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0028] The above and other features and advantages of this application will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0029] Figure 1 This is a schematic diagram of an energy storage system according to an exemplary embodiment.

[0030] Figure 2 This is an exploded structural diagram of an energy storage device according to an exemplary embodiment.

[0031] Figure 3 This is a top view of an end cap assembly according to an exemplary embodiment.

[0032] Figure 4 This is an end cap assembly shown according to related technology. Figure 3 The diagram shows a cross-sectional structure of AA'.

[0033] Figure 5 yes Figure 4 The diagram shows an enlarged view of the end cap assembly in a local area.

[0034] Figure 6 An end cap assembly is shown according to an exemplary embodiment along... Figure 3 The diagram shows a cross-sectional structure of AA'.

[0035] Figure 7 yes Figure 6 The diagram shows an enlarged view of the end cap assembly in a local area.

[0036] Figure 8 This is an exploded view of an end cap assembly according to an exemplary embodiment.

[0037] Figure 9 Another end cap assembly is shown according to an exemplary embodiment along... Figure 3 The diagram shows a cross-sectional structure of AA'.

[0038] Figure 10 yes Figure 9 The diagram shows an enlarged view of the end cap assembly in a local area.

[0039] Figure 11 This is yet another end cap assembly shown according to an exemplary embodiment. Figure 3 The diagram shows a cross-sectional structure of AA'.

[0040] Figure 12 yes Figure 11 The diagram shows an enlarged view of the end cap assembly in a local area.

[0041] Figure 13 This is a schematic diagram of the structure of an electrical device according to an exemplary embodiment.

[0042] The reference numerals in the attached figures are explained as follows:

[0043] 100. Energy storage devices; 200. Power conversion devices; 300. User loads; 400. Electrical equipment;

[0044] 10. Housing; 20. Electrode assembly; 30. End cap assembly;

[0045] 11. Receiving cavity;

[0046] 31. Cover plate; 32. Electrode terminal; 33. First insulating component; 34. Second insulating component; 35. Sealing ring; 36. Explosion-proof valve;

[0047] 311. First surface; 312. Second surface; 313. Mounting hole; 314. Injection hole;

[0048] 321. Electrode post; 322. Welding ring; 323. Lug; 324. Welding notch; 325. Welding protrusion; 326. Weld seam;

[0049] 3241, busbar; 3242, first busbar segment; 3243, second busbar segment; 3244, annular protrusion; 3261, first weld joint; 3262, second weld joint. Detailed Implementation

[0050] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0051] Because the energy people need is highly time- and space-dependent, in order to make rational use of energy and improve its utilization rate, it is necessary to use a medium or device to store one form of energy in the same form or convert it into another form of energy, and then release it in a specific form of energy based on future applications.

[0052] Currently, green energy mainly includes solar energy and wind energy. However, solar energy and wind energy generally suffer from strong intermittency and large fluctuations, which can cause voltage instability in the green power grid (insufficient electricity during peak demand and excessive electricity during off-peak demand). Unstable voltage can damage the power grid, and therefore may lead to the problem of "curtailment of wind and solar power" due to insufficient electricity demand or insufficient grid capacity.

[0053] To solve the problem of insufficient electricity demand or inadequate grid capacity, we must rely on energy storage devices. These devices convert electrical energy into other forms of energy through physical or chemical means and store it. When needed, the stored energy is converted back into electrical energy and released. Simply put, an energy storage device is like a large "power bank," storing electrical energy when solar and wind power are abundant and releasing it when required.

[0054] 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:

[0055] (1) Large energy storage containers applied on the grid side can serve as high-quality active and reactive power regulation power sources in the grid, realize load matching of electrical energy in time and space, enhance the absorption capacity of renewable energy, and play a significant role in grid system backup, alleviating peak load power supply pressure and peak regulation and frequency regulation.

[0056] (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 consumption between peak and off-peak periods, users with energy storage devices typically charge them during off-peak hours to reduce costs; during peak hours, they release the stored electricity for use, thus saving on electricity bills. 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.

[0057] This application provides an energy storage system, which includes an energy storage device for storing or supplying electrical energy.

[0058] Taking home energy storage scenarios on the user side as an example, Figure 1 This diagram illustrates an energy storage system according to an embodiment of this application. The system includes an energy storage device 100, a power conversion device 200 (e.g., a photovoltaic panel), and user loads 300 (e.g., streetlights, household appliances). The power conversion device 200 is electrically connected to the energy storage device 100, and the energy storage device 100 is electrically connected to the user loads 300. The energy storage device 100 is a small energy storage box that can be wall-mounted on an outdoor wall. Specifically, the power conversion device 200 converts solar energy into electrical energy, which is then stored in the energy storage device 100. This stored energy is then supplied to the user loads 300 during peak electricity price periods or during power outages / outages.

[0059] The energy storage device 100 can be, but is not limited to, a single battery cell (secondary battery), as well as battery modules, battery packs, battery systems, etc., composed of single batteries. The single battery cell can be a lithium-ion battery, lithium-sulfur battery, sodium-lithium-ion battery, sodium-ion battery, magnesium-ion battery, etc., and the single battery cell can be cylindrical, flat, cuboid, etc., which is not limited in the embodiments of this application. Specifically, the single battery cell can utilize the chemical reaction or change of the energy storage medium (chemical elements) to achieve the charging and discharging process. Simply put, the electrical energy generated by solar or wind energy is stored in the single battery cell through the chemical reaction or change of the energy storage medium. When the external electrical energy usage reaches its peak, the electrical energy stored in the single battery cell is released for use or transferred for later use through the chemical reaction or change of the energy storage medium.

[0060] In some implementations, such as Figure 2As shown, the energy storage device 100 includes: a housing 10, an electrode assembly 20, and an end cap assembly 30. The housing 10 has an open receiving cavity 11, the electrode assembly 20 is housed in the receiving cavity 11, and the end cap assembly 30 seals the opening of the receiving cavity 11.

[0061] The housing 10 can be a cylindrical structure with one end open. In this case, the energy storage device 100 includes an end cap assembly 30 to seal one opening of the housing 10. Alternatively, the housing 10 can be a cylindrical structure with both ends open. In this case, the energy storage device 100 includes an end cap assembly 30 and a cover plate 31, or two end cap assemblies 30, to seal the two openings of the housing 10 respectively through one end cap assembly 30 and a cover plate 31, or two end cap assemblies 30.

[0062] Among them, such as Figure 2 As shown, the end cap assembly 30 includes a cover plate 31 and an electrode terminal 32. The electrode terminal 32 passes through the cover plate 31, with one end connected to the electrode assembly 20 and the other end exposed to serve as an output terminal of the energy storage device 100. Figure 2 As shown, the end cap assembly 30 also includes an explosion-proof valve 36. An explosion-proof hole is provided on the cover plate 31, and the explosion-proof valve 36 is installed within the explosion-proof hole. The explosion-proof valve 36 is used to open when the pressure inside the receiving cavity 11 exceeds the valve opening pressure, thereby venting the gas inside the receiving cavity and improving the safety of the energy storage device 100. Additionally, as... Figure 2 As shown, the cover plate 31 is also provided with a liquid injection hole 314, which is connected to the receiving cavity 11 of the housing 10. After the basic assembly of the energy storage device 100 (i.e. the assembly of the basic structure) is completed, electrolyte is injected into the receiving cavity 11 of the housing 10 along the liquid injection hole 314 to achieve the immersion of the electrode assembly 20.

[0063] The electrode assembly 20 includes a first electrode, a second electrode, and a diaphragm stacked together. The first electrode and the second electrode have opposite polarities, and the diaphragm is located between the first electrode and the second electrode. The electrode assembly 20 has a first tab and a second tab at its end. The first tab and the second tab can be located at the same end of the electrode assembly 20 or at different ends of the electrode assembly 20.

[0064] Taking the housing 10 as a cylindrical structure with one end open as an example, the end cap assembly 30 includes a first electrode terminal 32 and a second electrode terminal 32 passing through the cover plate 31. The first electrode and the second electrode are located at the same end of the electrode assembly 20. At this time, the first electrode and the second electrode are connected to the first electrode terminal 32 and the second electrode terminal 32 respectively. The cover plate 31 seals the opening of the housing 10, and the basic assembly of the energy storage device 100 is completed, which facilitates the output of electrical energy through the first electrode terminal 32 and the second electrode terminal 32.

[0065] It should be noted that the energy storage device 100 also includes a metal adapter to connect the tabs of the electrode assembly 20 to the electrode terminals 32 of the end cap assembly 30, thereby ensuring the overcurrent capacity between the electrode assembly 20 and the electrode terminals 32.

[0066] In related technologies, such as Figure 3 , Figure 4 and Figure 5 As shown, the electrode terminal 32 includes an electrode post 321 and a welding ring 322. The electrode post 321 passes through the cover plate 31, and the welding ring 322 is sleeved on one end of the electrode post 321, forming a columnar welding seam 326 between them. Welding can be achieved by seam welding at the welding seam 326 between the electrode post 321 and the welding ring 322. However, because the welding seam 326 is located at the center of the welding trajectory, the heat is concentrated within it, which can easily cause instability in the welding keyhole, leading to welding pinholes or welding bursts. This can create a leakage channel within the welding seam 326, resulting in poor sealing of the electrode post 321 on the cover plate 31.

[0067] In the embodiments of this application, such as Figure 6 and Figure 7 As shown, the end cap assembly 30 includes a cover plate 31 and an electrode terminal 32. The cover plate 31 has a first surface 311 and a second surface 312 facing away from each other, and a mounting hole 313 extending from the first surface 311 to the second surface 312. The electrode terminal 32 includes an electrode post 321 and a welding ring 322. The electrode post 321 passes through the mounting hole 313, and the first end of the electrode post 321 is limited to the first surface 311 side of the cover plate 31. The welding ring 322 is located on the second surface 312 side of the cover plate 31 and is sleeved on the second end of the electrode post 321. The end face edge of the second end of the electrode post 321 has a welding notch 324. The inner wall of the welding ring 322 has a welding protrusion 325, which is located within the welding notch 324. The inner wall of the welding notch 324 and the surface of the welding protrusion 325 form a weld seam 326. The weld seam 326 has a first weld opening 3261 and a second weld opening 3262 distributed in the thickness direction of the cover plate 31. Both the first weld opening 3261 and the second weld opening 3262 are annular. The second weld is located between the first weld opening 3261 and the cover plate 31. The orthographic projection of the first weld opening 3261 on the cover plate 31 is located within the area enclosed by the inner edge of the orthographic projection of the second weld opening 3262 on the cover plate 31.

[0068] In this embodiment, the weld seam 326 formed by the cooperation of the welding notch 324 and the welding protrusion 325 is configured based on the relative positions of the first weld opening 3261 and the second weld opening 3262. This allows the weld seam 326 to be bent in the thickness direction of the cover plate 31. Consequently, when welding the weld seam 326, a seam weld effect can be formed near the first weld opening 3261, and a through weld effect can be formed near the second weld opening 3262. Furthermore, the bent weld seam can be formed between the first weld opening and the second weld opening. The space between the electrodes forms a barrier to block the heat generated during welding, causing the heat to concentrate mainly near the first weld opening 3261, thereby reducing the accumulation of heat at the second weld opening 3262. This helps to ensure the stability of the welding keyhole at the second weld opening 3262, and thus avoids the phenomenon of welding pinholes and welding bursts in the weld 326 near the second weld opening 3262. This ensures the reliability of the sealing welding of the weld 326 near the second weld opening 3262, which in turn ensures the reliability of the sealing assembly of the electrode post 321 on the cover plate 31.

[0069] Thus, when the aforementioned end cap assembly 30 is applied to the energy storage device 100, it facilitates ensuring the sealing reliability of the energy storage device 100, thereby ensuring the production yield of the energy storage device 100 and improving the safety of its use.

[0070] Among them, such as Figure 6 As shown, the sidewall of the first end of the electrode post 321 may be provided with a lug 323 to limit the first end of the electrode post 321 on the first surface 311 side of the cover plate 31. Of course, the first end of the electrode post 321 can also be limited to the first surface 311 side of the cover plate 31 in other ways, and the embodiments of this application are not limited in this regard. In addition, the welding notch 324 of the second end of the electrode post 321 is annular and is formed based on the absence of the sidewall and end face of the second end of the electrode post 321. That is, the welding notch 324 is formed around a ring edge on the end face of the second end and extends radially to the sidewall of the second end.

[0071] In addition to the cover plate 31 and electrode terminals 32, the end cap assembly 30 includes, for example, Figure 8 As shown, the end cap assembly 30 also includes a first insulating member 33 (e.g., upper plastic) and a second insulating member 34 (e.g., lower plastic). The first insulating member 33 is positioned between the lug 323 of the electrode post 321 and the cover plate 31; the second insulating member 34 is positioned between the welding ring 322 and the cover plate 31. Thus, the first insulating member 33 and the second insulating member 34 provide insulation between the cover plate 31 and the electrode post 321 and the welding ring 322, thereby preventing the cover plate 31 from becoming charged. The specific shapes of the first insulating member 33 and the second insulating member 34 can be found in related technologies, and this application does not limit them.

[0072] In addition, such as Figure 8 As shown, the end cap assembly 30 also includes a sealing ring 35, which is sleeved on the electrode post 321 and clamped between the welding ring 322 and the cover plate 31. Thus, the sealing ring 35 achieves a seal between the welding ring 322 and the cover plate 31. Alternatively, the sealing ring 35 can also be sleeved on the first insulating member 33, thereby achieving a seal between the sealing ring 35 and the first insulating member 33 while simultaneously creating a radial constraint on the first insulating member 33, thereby reducing the gap between the first insulating member 33 and the electrode post 321.

[0073] In some embodiments, the gap width of the weld seam 326 is less than or equal to 0.1 mm. Thus, when welding the weld seam 326, the small gap can be used to avoid the collapse of the molten pool caused by filling the gap. In other words, the small gap can be used to ensure the stability of the molten pool, thereby ensuring the reliability of the welding between the welding ring 322 and the electrode post 321.

[0074] For example, the gap width of weld 326 is 0.02 mm, 0.04 mm, 0.06 mm, 0.08 mm, 0.1 mm, etc.

[0075] Of course, for the weld seam 326 formed by the inner wall of the welding notch 324 and the surface of the welding protrusion 325, the gap width of the weld seam 326 can also be 0 mm, that is, the inner wall of the welding notch 324 and the surface of the welding protrusion 325 are at least partially in contact, thereby further ensuring the stability of the molten pool during welding; in addition, because of the 0 mm gap fit, the weld seam 326 has been sealed from the assembly point, thereby further ensuring the sealing performance of the weld seam 326.

[0076] In some implementations, such as Figure 7 As shown, in the thickness direction of the cover plate 31, the root dimension d of the welding protrusion 325 is greater than or equal to 0.5 mm and less than or equal to 1 mm.

[0077] In this way, when welding the weld seam 326, the welding protrusion 325 on the welding ring 322 is prevented from cracking at the root, thus ensuring the stability of the welding between the welding ring 322 and the electrode post 321.

[0078] For example, the dimension d of the root of the weld protrusion 325 in the thickness direction of the cover plate 31 is 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc.

[0079] For example, for the positive electrode post 321 made of aluminum, the root of the welding protrusion 325 on the corresponding welding ring 322 has a dimension of 0.8 mm in the thickness direction of the cover plate 31; for the negative electrode post 321 made of copper-aluminum composite, the root of the welding protrusion 325 on the corresponding welding ring 322 has a dimension of 0.7 mm in the thickness direction of the cover plate 31.

[0080] Additionally, the root corner of the weld protrusion 325 can be rounded to avoid stress concentration at the root of the weld protrusion 325 and to facilitate the stamping of the weld ring 322. For example, the radius (R) at the root corner of the weld protrusion 325 is R0.2 mm.

[0081] In some implementations, such as Figure 9 and Figure 10 As shown, the inner wall generatrix 3241 of the welding notch 324 is an arc-shaped curve that protrudes away from the welding ring 322.

[0082] Thus, based on the inner wall shape of the welding notch 324, the orthographic projection of the first weld opening 3261 of the weld seam 326 on the cover plate 31 is ensured to be located within the area enclosed by the inner edge of the orthographic projection of the second weld opening 3262 on the cover plate 31. At the same time, it is only necessary to ensure the fit between the inner wall of the welding notch 324 and the surface of the welding protrusion 325 in the thickness direction of the cover plate 31, thereby facilitating the formation of a small gap weld seam 326 to ensure the stability of the molten pool during welding.

[0083] The surface shape of the weld seam 326 formed on the weld protrusion 325 can be referenced to the inner wall shape of the weld notch 324, so as to ensure that the inner wall of the weld notch 324 and the surface of the weld protrusion 325 form the weld seam 326.

[0084] The inner wall generatrix 3241 of the welding notch 324 can be a circular arc curve or an elliptical arc curve, etc. Taking a circular arc curve as an example, such as... Figure 10 As shown, the central angle corresponding to the inner wall generatrix 3241 of the welding notch 324 is... The angle is greater than or equal to 90 degrees and less than or equal to 135 degrees. This facilitates the assembly and positioning of the welding protrusion 325 on the welding ring 322 within the welding notch 324, thereby improving the assembly efficiency of the welding ring 322. For example, the central angle corresponding to the inner wall generatrix 3241 of the welding notch 324... The degrees are 90, 95, 100, 105, 110, 115, 120, 125, 130, and 135 degrees.

[0085] Of course, the central angle corresponding to the inner wall generatrix 3241 of the welding notch 324 It can also be less than 90 degrees. For example, the central angle corresponding to the inner wall generatrix 3241 of the weld notch 324. The angles are 85 degrees, 80 degrees, 75 degrees, 70 degrees, etc., as long as it can be effectively ensured that when welding is performed at the first weld joint 3261 of weld joint 326, less heat is concentrated near the second weld joint 3262.

[0086] In the direction from the first weld opening 3261 to the second weld opening 3262, the inner wall of the welding notch 324 can be a smooth curved surface structure. Correspondingly, the surface on the welding protrusion 325 forming the weld seam 326 is also a smooth curved surface structure; of course, as Figure 11 and Figure 12 As shown, the inner wall of the weld notch 324 has a plurality of annular protrusions 3244 spaced apart in the direction from the first weld opening 3261 to the second weld opening 3262. By setting the plurality of annular protrusions 3244, the path length of the weld 326 is increased in the direction from the first weld opening 3261 to the second weld opening 3262, thereby reducing the accumulation of heat near the second weld opening 3262, that is, improving the stability of the welding keyhole in the weld 326 near the second weld opening 3262.

[0087] In other implementations, such as Figure 6 and Figure 7 As shown, the inner wall busbar 3241 of the welding notch 324 is a bent line, and includes a first busbar segment 3242 and a second busbar segment 3243; the weld segment corresponding to the first busbar segment 3242 extends to the end face of the second end of the electrode post 321, and the first included angle a1 formed by the first busbar segment 3242 and the second busbar segment 3243 is greater than or equal to 90 degrees and less than or equal to 135 degrees.

[0088] Thus, based on the inner wall shape of the welding notch 324, the orthographic projection of the first weld opening 3261 of the weld seam 326 on the cover plate 31 is ensured to be located within the area enclosed by the inner edge of the orthographic projection of the second weld opening 3262 on the cover plate 31. At the same time, a straight bend is achieved between the second busbar segment 3243 and the first busbar segment 3242, thereby effectively reducing the accumulation of heat near the second weld opening 3262 and improving the stability of the welding keyhole near the second weld opening 3262 in the weld seam 326.

[0089] The weld seam 326 includes a first weld seam segment corresponding to the first busbar segment 3242 and a second weld seam segment corresponding to the second busbar segment 3243. The first weld seam segment and the second weld seam segment are connected, and the first weld seam segment forms a first weld opening 3261, while the second weld seam segment forms a second weld opening 3262. Considering the gap width of the weld seam 326 described above, the gap width of the second weld seam segment can be set to be less than or equal to 0.1 mm. Further, the gap width of the second weld seam segment can be set to 0 mm, that is, a weld protrusion 325 is welded at the second weld seam segment to abut against the weld notch 324 to reduce molten pool collapse during welding.

[0090] For example, the first included angle a1 formed by the first busbar segment 3242 and the second busbar segment 3243 is 90 degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, etc.

[0091] In some implementations, such as Figure 7 As shown, the endpoint of the first busbar segment 3242 near the first weld opening 3261 is inclined away from the welding ring 322, and the second included angle α2 formed by the length direction of the first busbar segment 3242 and the thickness direction of the cover plate 31 is less than or equal to 45 degrees. This facilitates the assembly of the welding protrusion 325 within the welding notch 324.

[0092] For example, the second angle α2 formed by the length direction of the first busbar segment 3242 and the thickness direction of the cover plate 31 can be 0 degrees, 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, or 45 degrees. However, when the second angle α2 formed by the length direction of the first busbar segment 3242 and the thickness direction of the cover plate 31 is 0 degrees, the length direction of the first busbar segment 3242 is parallel to the thickness direction of the cover plate 31. This facilitates effective heat accumulation in the first weld segment, thereby reducing the heat accumulation near the second weld opening 3262 and ensuring improved stability of the welding keyhole near the second weld opening 3262 within the weld seam 326.

[0093] In some implementations, such as Figure 7 As shown, the third included angle a3 formed by the length direction of the second busbar segment 3243 and the thickness direction of the cover plate 31 is greater than or equal to 45 degrees and less than or equal to 90 degrees.

[0094] Among them, the end point of the second busbar segment 3243 near the second weld opening 3262 can be tilted towards the cover plate 31, or it can be tilted away from the cover plate 31, as long as the assembly of the welding protrusion 325 within the welding notch 324 can be guaranteed.

[0095] For example, the third angle α3 formed by the length direction of the second busbar segment 3243 and the thickness direction of the cover plate 31 can be 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, 85 degrees, or 90 degrees. However, when the third angle α3 formed by the length direction of the second busbar segment 3243 and the thickness direction of the cover plate 31 is 90 degrees, the length direction of the second busbar segment 3243 is perpendicular to the thickness direction of the cover plate 31. This facilitates effective heat accumulation in the first weld segment, thereby reducing the heat accumulation near the second weld opening 3262 and ensuring improved stability of the welding keyhole near the second weld opening 3262 within the weld seam 326.

[0096] This application also provides an electrical device 400, which can be a user energy storage cabinet, energy storage container, etc. Figure 13 As shown, the electrical device 400 includes the energy storage device 100 described in the above embodiments, and the energy storage device 100 supplies power to the electrical device 400. Thus, in conjunction with the above description, the electrical device 400 of this application can ensure the stability of its use during operation due to the reliable sealing of the energy storage device 100.

[0097] In the embodiments of this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0098] In the description of the embodiments of this application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0099] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the implementation of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0100] The above are merely preferred embodiments of the implementation methods of this application and are not intended to limit the implementation methods of this application. For those skilled in the art, various modifications and variations can be made to the implementation methods of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the implementation methods of this application should be included within the protection scope of the implementation methods of this application.

Claims

1. An end cap assembly, characterized in that, include: The cover plate (31) has a first surface (311) and a second surface (312) facing away from each other, and a mounting hole (313) extending from the first surface (311) to the second surface (312); The electrode terminal (32) includes an electrode post (321) and a welding ring (322). The electrode post (321) passes through the mounting hole (313), and the first end of the electrode post (321) is limited to the first surface (311) side of the cover plate (31). The welding ring (322) is located on the second surface (312) side of the cover plate (31) and is sleeved on the second end of the electrode post (321). The end face edge of the second end of the electrode post (321) has a welding notch (324), and the inner wall of the welding ring (322) has a welding protrusion (325). The welding protrusion (325) is located inside the welding notch (324), and the inner wall of the welding notch (324) and the surface of the welding protrusion (325) form a welding seam (326). The weld seam (326) has a first weld opening (3261) and a second weld opening (3262) distributed in the thickness direction of the cover plate (31). Both the first weld opening (3261) and the second weld opening (3262) are annular, and the second weld opening (3262) is located between the first weld opening (3261) and the cover plate (31). The orthographic projection of the first weld opening (3261) on the cover plate (31) is located in the area enclosed by the inner edge of the orthographic projection of the second weld opening (3262) on the cover plate (31).

2. The end cap assembly as claimed in claim 1, characterized in that, The inner wall generatrix (3241) of the welding notch (324) is an arc-shaped curve that protrudes away from the welding ring (322).

3. The end cap assembly as described in claim 2, characterized in that, The inner wall generatrix (3241) of the welding notch (324) is an arc-shaped curve, and the corresponding central angle (θ) is greater than or equal to 90 degrees and less than or equal to 135 degrees.

4. The end cap assembly as claimed in claim 2, characterized in that, The inner wall of the welding notch (324) has a plurality of annular protrusions (3244) spaced apart in the direction from the first weld opening (3261) to the second weld opening (3262).

5. The end cap assembly as claimed in claim 1, characterized in that, The inner wall busbar (3241) of the welding notch (324) is a bent line, and includes a first busbar segment (3242) and a second busbar segment (3243); The weld segment corresponding to the first busbar segment (3242) extends to the end face of the second end of the electrode post (321), and the first included angle (a1) formed by the first busbar segment (3242) and the second busbar segment (3243) is greater than or equal to 90 degrees and less than or equal to 135 degrees.

6. The end cap assembly as claimed in claim 5, characterized in that, The endpoint of the first busbar segment (3242) near the first weld opening (3261) is inclined away from the weld ring (322), and the second included angle (a2) formed by the length direction of the first busbar segment (3242) and the thickness direction of the cover plate (31) is less than or equal to 45 degrees.

7. The end cap assembly as claimed in claim 5, characterized in that, The third included angle (a3) ​​formed by the length direction of the second busbar segment (3243) and the thickness direction of the cover plate (31) is greater than or equal to 45 degrees and less than or equal to 90 degrees.

8. The end cap assembly as described in any one of claims 1-7, characterized in that, The weld width (326) is less than or equal to 0.1 mm.

9. The end cap assembly as described in any one of claims 1-7, characterized in that, In the thickness direction of the cover plate (31), the root dimension (d) of the welding protrusion (325) is greater than or equal to 0.5 mm and less than or equal to 1 mm.

10. An energy storage device, characterized in that, include: The housing (10) includes a receiving cavity (11) with an opening; Electrode assembly (20) is housed within the receiving cavity (11); The end cap assembly (30) according to any one of claims 1-9, wherein the end cap assembly (30) seals the opening of the receiving cavity (11).

11. An electrical appliance, characterized in that, The electrical equipment (400) includes the energy storage device (100) as described in claim 10, and the energy storage device (100) supplies power to the electrical equipment (400).

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