End cover assembly, energy storage device and electric equipment

Abstract

The invention discloses an end cover assembly, an energy storage device and electric equipment, and relates to the technical field of energy storage. The end cover assembly comprises a cover plate provided with a through mounting hole; the electrode terminal comprises an electrode column and a welding ring, the electrode column is arranged in the mounting hole in a penetrating mode, the first end portion of the electrode column is limited on the first surface side of the cover plate, and the welding ring is located on the second surface side of the cover plate and connected to the second end portion of the electrode column in a sleeving mode; the edge of the end face of the second end of the electrode column is provided with a welding notch, the inner wall of the welding ring is provided with a welding protrusion, a welding seam defined by the welding notch and the welding protrusion is provided with a first welding seam opening and a second welding seam opening, and the second welding seam opening is located between the first welding seam opening and the cover plate in the thickness direction of the cover plate. The orthographic projection of the first welding seam opening on the cover plate is located in an area defined by the inner edge of the orthographic projection of the second welding seam opening on the cover plate. In the embodiment of the invention, by adjusting the shape of the welding seam, the air tightness of the welding seam after welding is conveniently improved, so that the production yield is improved.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an end cover assembly, an energy storage device, and electrical equipment. Background Art

[0002] Rechargeable batteries, also known as rechargeable batteries or storage batteries, are batteries that can be recharged after discharge to reactivate their active materials and continue to be used. Their recyclable nature has made them a key source of power for electrical devices. As demand for rechargeable batteries grows, so too are the demands placed on their performance, particularly their lifespan.

[0003] In related technologies, secondary batteries typically consist of an end cap assembly, an electrode assembly, and a casing. The actual production process involves separately fabricating the end cap assembly, electrode assembly, and casing. Metal adapters are then used to weld the electrode posts and tabs of the end cap assembly together. The electrode assembly is then placed within the casing, and the opening of the casing is sealed with the end cap assembly. This completes the basic structure of the secondary battery. Afterwards, electrolyte is manually added through the injection hole provided in the end cap assembly, and the injection hole is sealed by welding.

[0004] Among them, the end cap assembly includes a cover plate and an electrode column, and the electrode column is sealed and penetrated on the cover plate. However, during the assembly process of the secondary battery, it is found that poor sealing is prone to occur between the electrode column and the cover plate, thereby reducing the production yield of the secondary battery. Summary of the Invention

[0005] A main purpose of the present application is to provide an end cap assembly, an energy storage device and an electrical equipment that are convenient for improving airtightness and thus improving production yield.

[0006] To achieve the above application objectives, this application adopts the following technical solutions:

[0007] According to one aspect of the present application, an end cap assembly is provided, comprising: a cover plate having a first surface and a second surface opposite to each other, and a mounting hole extending from the first surface to the second surface; an electrode terminal comprising an electrode column and a welding ring, the electrode column being inserted into the mounting hole, and the first end of the electrode column 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 being sleeved on the second end of the electrode column; an end face edge of the second end of the electrode column having a welding notch, an inner wall of the welding ring having a welding protrusion, the welding protrusion being located in the welding notch, and the inner wall of the welding notch and the surface of the welding protrusion forming a welding seam; the welding 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, and the orthographic projection of the first weld opening on the cover plate being located within the area surrounded by the inner edge of the orthographic projection of the second weld opening on the cover plate.

[0008] In the embodiment of the present application, the orthographic projection of the first weld opening on the cover plate is set to be located within the area enclosed by the orthographic projection of the second weld opening on the cover plate, so that the weld seam can be bent in the thickness direction of the cover plate, and then when the weld seam is welded, a seam welding effect can be formed near the first weld opening, and a penetration welding effect can be formed near the second weld opening; in addition, the bent weld seam can form a barrier to the heat generated by welding between the first weld opening and the second weld opening, so that the heat is mainly concentrated near the first weld opening, and the heat accumulation at the second weld opening is reduced, thereby facilitating the stability of the welding keyhole at the second weld opening, and thus avoiding the phenomenon of welding pinholes and welding explosion points in the weld seam near the second weld opening, so as to ensure the reliability of the sealed welding of the weld seam near the second weld opening, that is, to ensure the reliability of the sealed assembly of the electrode column on the cover plate.

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

[0010] In the embodiment of the present application, based on the inner wall shape of the welding notch, it is ensured that the orthographic projection of the first weld opening of the weld seam on the cover plate is located 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 weld seam with a small gap to ensure the stability of the molten pool during welding.

[0011] According to one embodiment of the present 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 the embodiment of the present application, by setting the central angle corresponding to the inner wall generatrix of the welding notch, it is convenient to achieve assembly limitation 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 the present application, the inner wall of the welding notch has a plurality of annular protrusions spaced apart in a direction from the first weld opening to the second weld opening.

[0014] In the embodiment of the present application, a wavy or serrated structure is set up to facilitate increasing the path of the weld in the direction from the first weld opening to the second weld opening, thereby reducing the accumulation of heat near the second weld opening, that is, improving the stability of the welding keyhole near the second weld opening in the weld.

[0015] According to one embodiment of the present application, the inner wall busbar of the welding notch is a broken line that is bent once, 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 portion of the electrode column, and the first 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 the embodiment of the present application, based on the inner wall shape of the welding notch, it is ensured that the orthographic projection of the first weld opening of the weld seam on the cover plate is located within the area enclosed by the orthographic projection of the second weld opening on the cover plate, and at the same time, a straight line bend between the second busbar segment and the first busbar segment is realized, 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 seam.

[0017] According to one embodiment of the present application, the endpoint of the first busbar segment close to the first weld opening is inclined in a direction away from the welding ring, and the second 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 the embodiment of the present application, it is convenient to ensure that heat is effectively accumulated in the first weld section, thereby reducing the heat accumulated near the second weld opening and ensuring that the stability of the welding keyhole near the second weld opening in the weld is improved.

[0019] According to one embodiment of the present application, a 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 the embodiment of the present application, it is convenient to ensure that heat is effectively accumulated in the first weld section, thereby reducing the heat accumulated near the second weld opening and ensuring that the stability of the welding keyhole near the second weld opening in the weld is improved.

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

[0022] In the embodiment of the present application, a small spacing can be set to ensure the stability of the molten pool during welding, that is, to ensure the reliability of the welding between the welding ring and the electrode column.

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

[0024] In the embodiment of the present application, by setting the size of the root of the welding protrusion, cracks are avoided at the root of the welding protrusion during welding of the welding seam, thereby ensuring the stability of the welding between the welding ring and the electrode column.

[0025] According to one aspect of the present application, an energy storage device is provided, comprising: a shell including a housing having an opening; an electrode assembly accommodated in the housing cavity; and the end cap assembly described in the above aspect, wherein the end cap assembly seals the opening of the housing cavity.

[0026] According to one aspect of the present application, an electric device is provided, which includes the energy storage device described in the above aspect, and the energy storage device supplies power to the electric device.

[0027] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other features and advantages of the present application will become more apparent by describing in detail example embodiments thereof with reference to the accompanying drawings.

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

[0030] Figure 2 FIG1 is a schematic diagram of an exploded structure of an energy storage device according to an exemplary embodiment.

[0031] Figure 3 It is a schematic top view of the structure of an end cover assembly according to an exemplary embodiment.

[0032] Figure 4 According to the related art, an end cap assembly is shown along Figure 3 The cross-sectional structural diagram of AA' is shown.

[0033] Figure 5 yes Figure 4 The diagram shows an enlarged structural diagram of a local area of ​​the end cover assembly.

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

[0035] Figure 7 yes Figure 6 The diagram shows an enlarged structural diagram of a local area of ​​the end cover assembly.

[0036] Figure 8 is a schematic diagram of an exploded structure of an end cover assembly according to an exemplary embodiment.

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

[0038] Figure 10 yes Figure 9 The diagram shows an enlarged structural diagram of a local area of ​​the end cover assembly.

[0039] Figure 11 Another end cap assembly according to an exemplary embodiment is shown along Figure 3 The cross-sectional structural diagram of AA' is shown.

[0040] Figure 12 yes Figure 11 The diagram shows an enlarged structural diagram of a local area of ​​the end cover assembly.

[0041] Figure 13 It is a schematic structural diagram of an electric device according to an exemplary embodiment.

[0042] The description of the accompanying drawings is as follows:

[0043] 100, energy storage device; 200, electric energy conversion device; 300, user load; 400, electrical equipment;

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

[0045] 11. Accommodating cavity;

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

[0047] 311, first surface; 312, second surface; 313, mounting hole; 314, injection hole;

[0048] 321, electrode column; 322, welding ring; 323, lug; 324, welding notch; 325, welding protrusion; 326, welding seam;

[0049] 3241. Busbar; 3242. First busbar section; 3243. Second busbar section; 3244. Annular protrusion; 3261. First weld opening; 3262. Second weld opening. DETAILED DESCRIPTION

[0050] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent like or similar structures, and thus their detailed description will be omitted.

[0051] Since the energy people need is highly temporal and spatial, in order to make rational use of energy and improve utilization rate, it is necessary to use a medium or equipment to store one form of energy in the same energy form, or convert it into another form of energy, and then release it in a specific energy form based on future applications.

[0052] At present, green energy mainly includes solar energy, wind energy, etc., which generally have the problems of strong intermittency and large volatility, which will cause the voltage of the green power grid to be unstable (not enough electricity during peak hours and too much electricity during low hours). Unstable voltage will cause damage to electricity. Therefore, it may cause the problem of "wind and solar power abandonment" due to insufficient electricity demand or insufficient grid acceptance capacity.

[0053] To address the issue of insufficient electricity demand or insufficient grid capacity, energy storage devices are essential. These devices convert electrical energy into other forms of energy through physical or chemical means, storing it. When needed, the stored energy is converted back into electricity and released. Simply put, an energy storage device acts like a large "power bank," storing electricity when there's sufficient solar or wind energy and releasing it when needed.

[0054] Currently, energy storage (i.e., energy storage) has a wide range of application scenarios, including power 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 used on the grid side can serve as high-quality active and reactive power regulation power sources in the grid, achieving load matching of electricity in time and space, enhancing the ability to absorb renewable energy, and are of great significance in grid system backup, alleviating peak load power supply pressure, and peak and frequency regulation;

[0056] (2) The main operating mode of small and medium-sized energy storage cabinets used in industrial and commercial energy storage scenarios (banks, shopping malls, etc.) on the user side and small household energy storage boxes used in home energy storage scenarios on the user side is "peak shaving and valley filling". Since there is a large price difference in electricity prices at peak and valley locations according to electricity demand, after users have energy storage equipment, in order to reduce costs, they usually charge the energy storage device (energy storage cabinet / box) during the low electricity price period; during the peak electricity price period, the electricity in the energy storage device is discharged for use to achieve the purpose of saving electricity bills. In addition, in remote areas and areas with high incidence of natural disasters such as earthquakes and hurricanes, the existence of household energy storage devices is equivalent to users providing themselves and the power grid with backup power, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0057] An embodiment of the present application provides an energy storage system, which includes an energy storage device to store or supply electric energy through the energy storage device.

[0058] Taking the user-side home energy storage scenario as an example, Figure 1 The schematic diagram of an energy storage system provided by an embodiment of the present application is shown. The energy storage system includes an energy storage device 100 and an electric energy conversion device 200 (such as a photovoltaic panel), and a user load 300 (such as a street lamp, household appliance, etc.). The electric energy conversion device 200 is electrically connected to the energy storage device 100, and the energy storage device 100 is electrically connected to the user load 300. The energy storage device 100 is a small energy storage box that can be mounted on an outdoor wall by wall-mounting. Specifically, the electric energy conversion device 200 can convert solar energy into electrical energy and store it through the energy storage device 100, and then supply the user load 300 for use when the electricity price is peak, or supply the user load 300 for use when the power grid is outage / power outage.

[0059] Among them, the energy storage device 100 can be but is not limited to a single cell (secondary battery), and a battery module, battery pack, battery system, etc. composed of single cells. The battery cell can be a lithium-ion battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc., and the battery cell can be cylindrical, flat, rectangular, etc., and the embodiment of the present application does not limit this. Specifically, the battery cell can utilize the chemical reaction or change of the energy storage medium (chemical element) to realize the charging and discharging process. Simply put, the electric energy generated by light energy and wind energy is stored in the battery cell through the chemical reaction or change of the energy storage medium. When the use of external electric energy reaches a peak, the electric energy stored in the battery cell is released for use through the chemical reaction or change of the energy storage medium, or transferred for use.

[0060] In some embodiments, as Figure 2As shown, the energy storage device 100 includes: a shell 10, an electrode assembly 20 and an end cover assembly 30. The shell 10 has an open accommodating cavity 11, the electrode assembly 20 is accommodated in the accommodating cavity 11, and the end cover assembly 30 seals the opening of the accommodating cavity 11.

[0061] The shell 10 may be a cylindrical structure with one end open, in which case the energy storage device 100 includes an end cover assembly 30 to seal one opening of the shell 10 . Of course, the shell 10 may also be a cylindrical structure with both ends open, in which case the energy storage device 100 includes an end cover assembly 30 and a cover plate 31 , or includes two end cover assemblies 30 , in which case the two openings of the shell 10 are sealed respectively by one end cover assembly 30 and a cover plate 31 , or two end cover 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 is provided on the cover plate 31, and one end of the electrode terminal 32 is connected to the electrode assembly 20, and the other end is exposed to the outside to serve as an output end of the energy storage device 100. Figure 2 As shown, the end cover assembly 30 further includes an explosion-proof valve 36. An explosion-proof hole is provided on the cover plate 31. The explosion-proof valve 36 is assembled in the explosion-proof hole. The explosion-proof valve 36 is used to explode when the pressure in the accommodating chamber 11 is greater than the valve opening pressure, and to discharge the gas in the accommodating chamber to improve the safety of the energy storage device 100. In addition, as shown in FIG. Figure 2 As shown, a liquid injection hole 314 is also provided on the cover plate 31, and the liquid injection hole 314 is connected to the accommodating cavity 11 of the shell 10, so that after the basic assembly of the energy storage device 100 (i.e., the assembly of the basic structure) is completed, the electrolyte is added into the accommodating cavity 11 of the shell 10 along the liquid injection hole 314 to achieve the infiltration of the electrode assembly 20.

[0063] Among them, the electrode assembly 20 includes a first electrode plate, a second electrode plate and a diaphragm that are stacked, the polarity of the first electrode plate and the second electrode plate are opposite, and the diaphragm is located between the first electrode plate and the second electrode plate, and the end of the electrode assembly 20 has a first electrode ear and a second electrode ear, and the first electrode ear and the second electrode ear can be located at the same end of the electrode assembly 20 or at different ends of the electrode assembly 20.

[0064] Taking the shell 10 as an example of a cylindrical structure with one end open, the end cover assembly 30 includes a first electrode terminal 32 and a second electrode terminal 32 penetrated on the cover plate 31, and the first electrode tab and the second electrode tab are located at the same end of the electrode assembly 20. At this time, the first electrode tab and the second electrode tab are respectively connected to the first electrode terminal 32 and the second electrode terminal 32. The cover plate 31 seals the opening of the shell 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 tab included in the electrode assembly 20 and the electrode terminal 32 included in the end cover assembly 30 through the metal adapter, thereby ensuring the flow capacity between the electrode assembly 20 and the electrode terminal 32.

[0066] In related technologies, such as Figure 3 、 Figure 4 and Figure 5 As shown, the electrode terminal 32 includes an electrode column 321 and a welding ring 322. The electrode column 321 is inserted into the cover plate 31, and the welding ring 322 is sleeved onto one end of the electrode column 321, forming a columnar weld seam 326 between the electrode column 321. Thus, seam welding can be performed on the weld seam 326 between the electrode column 321 and the welding ring 322. However, since the weld seam 326 is located at the center of the welding trajectory, heat is concentrated within the weld seam 326, which can easily cause instability in the welding keyhole, leading to weld pinholes or weld explosion points, and forming leakage channels within the weld seam 326, resulting in poor sealing of the electrode column 321 on the cover plate 31.

[0067] In the embodiment of this application, 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 having a first surface 311 and a second surface 312 opposite to 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 column 321 and a welding ring 322, the electrode column 321 is inserted into the mounting hole 313, and the first end of the electrode column 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 column 321; the end surface edge of the second end of the electrode column 321 has a welding notch 324 The inner wall of the welding ring 322 has a welding protrusion 325, which is located in 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 welding seam 326 has a first weld opening 3261 and a second weld opening 3262 distributed in the thickness direction of the cover plate 31. The first weld opening 3261 and the second weld opening 3262 are both annular, and 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 in the area surrounded by the inner edge of the orthographic projection of the second weld opening 3262 on the cover plate 31.

[0068] In the embodiment of the present application, for the welding seam 326 formed by the cooperation of the welding notch 324 and the welding protrusion 325, based on the relative position setting of the first welding seam opening 3261 and the second welding seam opening 3262, the welding seam 326 can be bent in the thickness direction of the cover plate 31, and then when the welding seam 326 is welded, a seam welding effect can be formed near the first welding seam opening 3261, and a penetration welding effect can be formed near the second welding seam opening 3262; in addition, the bent welding seam can be formed between the first welding seam opening and the second welding seam opening. The heat generated by welding is blocked in the gap, so that the heat is mainly concentrated near the first weld opening 3261, so as to reduce the accumulation of heat at the second weld opening 3262, thereby ensuring the stability of the welding keyhole at the second weld opening 3262, and thus avoiding the occurrence of welding pinholes and welding explosion points in the weld 326 near the second weld opening 3262, so as to ensure the reliability of the sealed welding of the weld 326 near the second weld opening 3262, that is, to ensure the reliability of the sealed assembly of the electrode column 321 on the cover plate 31.

[0069] Thus, when the end cap assembly 30 is applied to the energy storage device 100 , it is easy to ensure 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 use.

[0070] Among them, such as Figure 6 As shown, the side wall of the first end portion of the electrode column 321 may be provided with a lug 323, so as to limit the first end portion of the electrode column 321 on the side of the first surface 311 of the cover plate 31 based on the lug 323. Of course, the first end portion of the electrode column 321 may also be limited to the side of the first surface 311 of the cover plate 31 by other means, and the embodiments of the present application are not limited to this. In addition, the welding notch 324 at the second end portion of the electrode column 321 is annular and is formed based on the absence of the side wall and end face of the second end portion of the electrode column 321, that is, the welding notch 324 is formed around a circle of edges on the end face of the second end portion and extends radially to the side wall of the second end portion.

[0071] The end cap assembly 30 includes a cover plate 31 and an electrode terminal 32. 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 column 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 arrangement of the first insulating member 33 and the second insulating member 34 achieves insulation between the cover plate 31 and the electrode column 321 and the welding ring 322, thereby preventing the cover plate 31 from becoming electrically charged. The specific shapes of the first insulating member 33 and the second insulating member 34 can be referenced in related art and are not limited in this embodiment of the present application.

[0072] In addition, if Figure 8 As shown, the end cap assembly 30 further includes a sealing ring 35, which is sleeved onto the electrode column 321 and clamped between the welding ring 322 and the cover plate 31. Thus, the provision of the sealing ring 35 can achieve a seal between the welding ring 322 and the cover plate 31. Of course, the sealing ring 35 can also be sleeved onto the first insulating member 33, thereby achieving a seal between the sealing ring 35 and the first insulating member 33 while also radially constraining the first insulating member 33, thereby narrowing the gap between the first insulating member 33 and the electrode column 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, a small gap can be provided to prevent the molten pool from collapsing due to filling the gap. In other words, a small gap can be provided to ensure the stability of the molten pool, thereby ensuring the reliability of the welding between the welding ring 322 and the electrode column 321.

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

[0075] Of course, for the welding seam 326 formed by the inner wall of the welding notch 324 and the surface of the welding protrusion 325, the partial gap width of the welding 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 with each other, thereby further ensuring the stability of the molten pool during welding; in addition, because of the 0 mm clearance fit, the sealing of the welding seam 326 has been achieved in terms of assembly, thereby further ensuring the sealing of the welding seam 326.

[0076] In some embodiments, 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 welding seam 326 , cracks are avoided at the root of the welding protrusion 325 on the welding ring 322 , thereby ensuring the stability of the welding between the welding ring 322 and the electrode column 321 .

[0078] For example, the dimension d of the root of the welding 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 column 321 made of aluminum, the root of the welding protrusion 325 on the corresponding welding ring 322 has a size of 0.8 mm in the thickness direction of the cover plate 31; for the negative electrode column 321 made of copper-aluminum composite, the root of the welding protrusion 325 on the corresponding welding ring 322 has a size of 0.7 mm in the thickness direction of the cover plate 31.

[0080] In addition, the root corner of the welding protrusion 325 can be set as an arc chamfer to avoid stress concentration at the root of the welding protrusion 325 and facilitate the stamping of the welding ring 322. For example, the R angle at the root corner of the welding protrusion 325 is R0.2 mm.

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

[0082] In this way, based on the inner wall shape of the welding notch 324, it is ensured that the orthographic projection of the first weld opening 3261 of the weld seam 326 on the cover plate 31 is located within the area surrounded 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 cooperation 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, so as to facilitate the formation of a weld seam 326 with a small gap to ensure the stability of the molten pool during welding.

[0083] The surface shape of the welding seam 326 formed on the welding protrusion 325 may refer to the inner wall shape of the welding notch 324 to ensure that the welding seam 326 is formed between the inner wall of the welding notch 324 and the surface of the welding protrusion 325 .

[0084] The inner wall busbar 3241 of the welding notch 324 can be an arc curve or an elliptical arc curve. Taking the arc curve as an example, Figure 10 As shown, the central angle of the inner wall busbar 3241 of the welding notch 324 corresponds to In this way, it is easy to realize the assembly limit of the welding protrusion 325 on the welding ring 322 in the welding notch 324, thereby improving the assembly efficiency of the welding ring 322. For example, the central angle of the inner wall busbar 3241 of the welding notch 324 corresponds to 90 degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, etc.

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

[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, and accordingly, the surface forming the welding seam 326 on the welding protrusion 325 is also a smooth curved surface structure; of course, as Figure 11 and Figure 12 As shown, 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. By setting the plurality of annular protrusions 3244, the path length of the weld seam 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 seam 326 near the second weld opening 3262.

[0087] In other embodiments, Figure 6 and Figure 7 As shown, the inner wall busbar 3241 of the welding notch 324 is a broken line with a single bend, 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 portion of the electrode column 321, and the first 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] In this way, based on the inner wall shape of the welding notch 324, the positive 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 surrounded by the inner edge of the positive projection of the second weld opening 3262 on the cover plate 31, and at the same time, a straight line bend between the second bus segment 3243 and the first bus segment 3242 is realized, 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 segment corresponding to the first busbar segment 3242 and a second weld segment corresponding to the second busbar segment 3243. The first weld segment is connected to the second weld segment, and the first weld segment forms a first weld opening 3261, while the second weld segment forms a second weld opening 3262. In conjunction with the gap width of the weld seam 326 described above, the gap width of the second weld segment can be set to be less than or equal to 0.1 mm. Furthermore, the gap width of the second weld segment can be set to 0 mm, that is, the weld protrusion 325 at the second weld segment abuts the weld notch 324, thereby reducing molten pool collapse during welding.

[0090] For example, the first angle a1 formed by the first bus-segment 3242 and the second bus-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 embodiments, 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 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. This facilitates the assembly of the welding protrusion 325 within the welding notch 324.

[0092] For example, the second angle a2 formed between the length direction of the first busbar segment 3242 and the thickness direction of the cover plate 31 is 0 degrees, 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, etc. When the second angle a2 formed between 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 ensures that heat is effectively concentrated in the first weld section, thereby reducing heat accumulation 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.

[0093] In some embodiments, as Figure 7 As shown, a third 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] The end point of the second busbar segment 3243 close to the second weld opening 3262 can be tilted toward the cover plate 31 , or can be tilted away from the cover plate 31 , as long as the assembly of the welding protrusion 325 in the welding notch 324 can be ensured.

[0095] For example, the third angle a3 formed between the length direction of the second busbar segment 3243 and the thickness direction of the cover plate 31 is 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, 85 degrees, 90 degrees, etc. When the third angle a3 formed between 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 ensures that heat is effectively concentrated in the first weld section, thereby reducing heat accumulation 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.

[0096] The embodiment of the present application also provides an electric device 400, which can be a user energy storage cabinet, an energy storage container, etc. Figure 13 As shown, the electrical device 400 includes the energy storage device 100 described in the above embodiment, and the energy storage device 100 supplies power to the electrical device 400. Thus, in combination with the above, the electrical device 400 of the present application can ensure the stability of the electrical device 400 during use based on the reliability of the sealing of the energy storage device 100.

[0097] In the embodiments of the present application, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance; the term "plurality" refers to two or more, unless otherwise expressly defined. Terms such as "installed", "connected", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0098] In the description of the embodiments of the present application, it should be understood that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the embodiments of the present application.

[0099] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the implementation methods of this application. In this specification, schematic representations 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 any one or more embodiments or examples.

[0100] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be modified and varied in various ways. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. An end cap assembly, characterized in that: include: The cover plate (31) has a first surface (311) and a second surface (312) opposite to each other, and a mounting hole (313) extending from the first surface (311) to the second surface (312); An electrode terminal (32) comprising an electrode column (321) and a welding ring (322), wherein the electrode column (321) is inserted into the mounting hole (313), and the first end of the electrode column (321) is limited to the first surface (311) side of the cover plate (31), and 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 column (321); The end face edge of the second end portion of the electrode column (321) has a welding notch (324), the inner wall of the welding ring (322) has a welding protrusion (325), the welding protrusion (325) is located in 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) comprises a first weld opening (3261) and a second weld opening (3262) distributed in the thickness direction of the cover plate (31); the first weld opening (3261) and the second weld opening (3262) are both 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 within 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 according to claim 1, wherein: The inner wall generatrix (3241) of the welding notch (324) is an arc-shaped curve that bulges away from the welding ring (322).

3. The end cap assembly according to claim 2, wherein: The inner wall generatrix (3241) of the welding notch (324) is an arc-shaped curve, and the corresponding center angle (θ) is greater than or equal to 90 degrees and less than or equal to 135 degrees.

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

5. The end cap assembly according to claim 1, wherein: The inner wall busbar (3241) of the welding notch (324) is a broken line that is bent once, and includes a first busbar segment (3242) and a second busbar segment (3243); The weld section corresponding to the first busbar segment (3242) extends through the end face of the second end portion of the electrode column (321), and a first 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 according to claim 5, wherein: The endpoint of the first busbar segment (3242) close to the first weld opening (3261) is inclined in a direction away from the welding ring (322), and a second 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 according to claim 5, wherein: A third angle (a3) ​​formed between 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 according to any one of claims 1 to 7, wherein: The gap width of the welding seam (326) is less than or equal to 0.1 mm.

9. The end cap assembly according to any one of claims 1 to 7, wherein: In the thickness direction of the cover plate (31), a root size (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: A housing (10) comprising a receiving cavity (11) having an opening; An electrode assembly (20) is accommodated in the accommodating cavity (11); The end cover assembly (30) according to any one of claims 1 to 9, wherein the end cover assembly (30) seals the opening of the accommodating cavity (11).

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

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