Energy storage device and electric equipment

Abstract

The utility model discloses an energy storage device and electric equipment. The energy storage device comprises an electrode assembly, a top cover piece and a sealing piece. And the top cover piece is positioned on one side of the electrode assembly where the tabs are positioned. The top cover piece is provided with a first surface and a second surface, the top cover piece is further provided with a first sinking groove, a second sinking groove and a liquid injection hole, the first sinking groove is sunken inwards from the second surface, the second sinking groove is sunken inwards from the groove bottom face of the first sinking groove, and the liquid injection hole penetrates through the groove bottom face of the second sinking groove and the first surface; the second sinking groove is a conical groove, and an opening close to the second surface is large. The groove side wall of the second sinking groove is provided with a first inner conical surface; the sealing piece comprises a body and an annular flange, part of the body is located in the second sinking groove and provided with a first outer conical surface matched with the first inner conical surface, and the annular flange is integrally arranged on the peripheral side face of the body in a protruding mode, connected to the groove bottom face of the first sinking groove in a lap joint mode and welded to the top cover piece.

Description

Technical Field

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

[0002] A battery in the related art includes a housing, an electrode assembly, and a cover plate. The housing includes a receiving cavity with an opening, the electrode assembly is disposed within the receiving cavity, and the cover plate seals the opening. The cover plate has an injection hole through which electrolyte is injected into the receiving cavity. The battery also includes a sealant. After the electrolyte is injected, the sealant is welded to seal the injection hole to prevent leakage of the electrolyte from the injection hole.

[0003] However, during the electrolyte injection process, the electrolyte tends to accumulate around the injection hole. If it is not cleaned thoroughly, welding defects may occur in the welding area between the seal and the cover plate, thereby reducing the sealing performance of the injection hole. Utility Model Content

[0004] The embodiments of the present application provide an energy storage device and an electrical device to solve the problem in the related art that the welding quality of the welding area between the seal and the cover plate is poor, thereby affecting the sealing of the liquid injection hole.

[0005] The energy storage device of the embodiment of the present application includes:

[0006] An electrode assembly having a tab;

[0007] a top cover member located on the side of the electrode assembly where the tab is located; the top cover member has a first surface facing the electrode assembly and a second surface facing away from the electrode assembly; the top cover member further has a first sunken groove, a second sunken groove, and a liquid injection hole; the first sunken groove is recessed inward from the second surface; the second sunken groove is recessed inward from the bottom surface of the first sunken groove; the liquid injection hole passes through the bottom surface of the second sunken groove and the first surface; the second sunken groove is a tapered groove, and the opening near the second surface is larger; the groove sidewall of the second sunken groove has a first inner conical surface;

[0008] The sealing member includes a main body and an annular flange. Part of the main body is located in the second sink groove and has a first outer conical surface that cooperates with the first inner conical surface. The annular flange is integrally protruded on the outer peripheral side of the main body, overlaps the bottom surface of the first sink groove, and is welded to the top cover member.

[0009] In an embodiment of the present application, the top cover comprises a first recessed groove and a second recessed groove. The first recessed groove is recessed inward from the second surface, while the second recessed groove is recessed inward from the bottom of the first recessed groove. The injection hole extends through the bottom of the second recessed groove and the first surface, thereby forming a stepped surface around the injection hole. This increases the distance between the bottom of the first recessed groove and the injection hole. During or after the injection process, electrolyte is less likely to spill onto the bottom of the first recessed groove. This reduces the risk of poor electrolyte cleaning affecting the weld quality between the annular flange and the top cover, and prevents weld defects that could compromise the sealing of the injection hole. Furthermore, the sidewall of the first recessed groove comprises a first inner conical surface, and the body of the seal comprises a first outer conical surface that mates with the first inner conical surface. During assembly of the seal and top cover, the first inner conical surface and the first outer conical surface provide a guiding fit, making it easier for the seal to align with the injection hole of the top cover during assembly, thus avoiding inconsistent weld penetration caused by the seal being tilted relative to the top cover. At the same time, since the main body of the sealing member is more easily inserted into the second sink, the efficiency of the automated assembly can be improved. Therefore, the welding quality is improved while the welding process capability is improved.

[0010] Optionally, the annular flange is welded to the side wall of the first sink trough to form a first annular welding portion, and the annular flange is welded to the bottom wall of the first sink trough to form a second annular welding portion.

[0011] In this embodiment of the present application, a stepped surface is formed around the injection hole, making the thickness of the annular flange smaller than the thickness of the entire seal, allowing for through-welding. Therefore, during welding, not only is a first annular weld formed between the annular flange and the sidewall of the first sink, but a second annular weld is also formed between the annular flange and the bottom wall of the first sink. The combined effect of these first and second annular welds improves the weld strength between the seal and the top cover.

[0012] Optionally, the annular flange has a first thickness t1, the main body has a second thickness t2, and t1 and t2 satisfy 1 / 3≤t1 / t2≤1 / 2.

[0013] In the embodiment of the present application, by reducing the thickness of the annular flange, the power requirement for the welding equipment can be reduced, the welding efficiency can be improved, and costs can be saved.

[0014] Optionally, the bottom surface of the first trough has a sloped surface, which is connected to the side surface of the first trough, extends from the side surface of the first trough in a direction away from the second surface, and is connected to the first inner conical surface; the annular flange overlaps the sloped surface.

[0015] In an embodiment of the present application, the sloped surface is connected to the side surface of the first trough, and extends from the side surface of the first trough in a direction away from the second surface, and is connected to the first inner conical surface, that is, the end of the sloped surface away from the injection hole is higher, and the end of the sloped surface close to the injection hole is lower. In this way, when electrolyte remains in the first trough, the electrolyte can flow back to the injection hole along the sloped surface by its own gravity, preventing the electrolyte from accumulating on the bottom surface of the first trough, thereby ensuring the welding quality of the seal and the top cover.

[0016] Optionally, the slope surface is a conical surface.

[0017] In the embodiment of the present application, the slope surface is designed to be a conical surface, so that the electrolyte dripping into the first trough can flow back to the injection hole more easily and more thoroughly.

[0018] Optionally, a side surface of the body facing away from the liquid injection hole and a side surface of the annular flange facing away from the bottom surface of the first sink are flush with the second surface.

[0019] In the embodiment of the present application, by designing the side surface of the main body facing away from the liquid injection hole, the side surface of the annular flange facing away from the bottom surface of the first sink groove, and the second surface of the top cover to be flush, the flatness of the overall surface of the energy storage device can be improved and the aesthetics can be enhanced.

[0020] Optionally, the top cover further has a third groove, which is recessed inward from the bottom surface of the second groove, and the injection hole passes through the bottom surface of the third groove; part of the body is located in the third groove.

[0021] In an embodiment of the present application, the top cover member has a first groove, a second groove and a third groove. The first groove is recessed inward from the second surface, the second groove is recessed inward from the bottom surface of the first groove, and the third groove is recessed inward from the bottom surface of the second groove. The injection hole passes through the bottom surface of the third groove, thereby forming two step surfaces around the injection hole, further increasing the distance between the bottom surface of the first groove and the injection hole, thereby reducing the welding quality of the annular flange and the cover plate due to incomplete electrolyte cleaning, and avoiding affecting the sealing of the injection hole due to welding defects.

[0022] Optionally, the third groove is a conical groove, and the opening close to the second surface is larger, and the groove side wall of the third groove has a second inner conical surface; the outer peripheral side surface of the body has a second outer conical surface that matches the second inner conical surface.

[0023] In the embodiments of the present application, during assembly of the seal and top cover, the second inner conical surface and the second outer conical surface provide a guiding fit, making it easier for the seal to align with the top cover's injection hole during assembly, thus avoiding the problem of inconsistent weld penetration caused by the seal's relative misalignment. Furthermore, since the seal's main body is more easily inserted into the third sink, automated assembly efficiency is improved. Consequently, welding quality is enhanced while improving welding process capability.

[0024] Optionally, the energy storage device further comprises a housing, the housing comprises a receiving cavity having an opening, the electrode assembly is disposed in the receiving cavity, the top cover is a cover plate of the energy storage device, the cover plate is connected to the housing, and seals the opening; or,

[0025] The energy storage device also includes an outer shell and an end plate, the outer shell includes a accommodating cavity with an opening, the electrode assembly is arranged in the accommodating cavity, the end plate is connected to the outer shell and seals the opening; the end plate has a through hole, and the through hole passes through the end plate along the thickness direction of the end plate; the top cover is a current collecting disk of the energy storage device, and the current collecting disk includes a disk body and a connecting portion arranged coaxially, the disk body is arranged between the end plate and the electrode assembly, and is connected to the pole ear of the electrode assembly; the connecting portion is connected to the disk body and is passed through the through hole; the side surface of the connecting portion facing the electrode assembly is the first surface, and the side surface of the connecting portion facing away from the electrode assembly is the second surface.

[0026] The electrical equipment of the embodiment of the present application includes the energy storage device described in any one of the above items, and the energy storage device supplies power to the electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Shown is a structural schematic diagram of a household energy storage system.

[0028] Figure 2 Shown is a schematic diagram of an exploded view of a rectangular battery.

[0029] Figure 3 Shown is a schematic exploded view of the sealing member and the cover plate of the first embodiment of the present application.

[0030] Figure 4 Shown is a cross-sectional view of the sealing member and the cover plate after welding according to the first embodiment of the present application.

[0031] Figure 5 Shown is a three-dimensional schematic diagram of the sealing member according to the first embodiment of the present application.

[0032] Figure 6 Shown is a cross-sectional view of the sealing member and the cover plate after welding according to the second embodiment of the present application.

[0033] Figure 7 Shown is a cross-sectional view of the sealing member and the cover plate after welding according to the third embodiment of the present application.

[0034] Figure 8 Shown is a schematic diagram of an exploded cylindrical battery.

[0035] Figure 9 Shown is a schematic diagram of an electrical device according to an embodiment of the present application.

[0036] The description of the accompanying drawings is as follows:

[0037] 1. Energy storage device; 2. Electric energy conversion device; 3. User load; 4. Electrical equipment;

[0038] 100, housing; 101, opening; 110, accommodating cavity;

[0039] 200, electrode assembly; 201, tab;

[0040] 300, top cover; 300a, cover plate; 300b, collecting tray; 301, first surface; 302, second surface; 310, first sink; 311, sloped surface; 320, second sink; 321, first inner conical surface; 330, third sink; 331, second inner conical surface; 340, injection hole; 350, tray body; 360, connecting portion; 370, pole; 380, explosion-proof valve;

[0041] 400, sealing member; 410, body; 411, first outer conical surface; 412, second outer conical surface; 420, annular flange;

[0042] 510, first annular welding portion; 520, second annular welding portion;

[0043] 600, end plate; 601, via. DETAILED DESCRIPTION

[0044] 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.

[0045] It is understood that the terms "including" and "having" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or components inherent to the process, method, product, or apparatus.

[0046] Since the energy people need is highly temporal and spatial, in order to make rational use of energy and improve energy utilization, 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 application needs.

[0047] 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:

[0048] (1) Large energy storage containers used in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the grid, 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;

[0049] (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 cabinets / boxes during the low electricity price period; during the peak electricity price period, the electricity in the energy storage equipment 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.

[0050] Take the household energy storage scenario in user-side energy storage as an example to illustrate. Figure 1The diagram shows a household energy storage system, which includes an energy storage device 1, an electric energy conversion device 2 (such as a photovoltaic panel), and user loads 3 (such as street lights, household appliances, etc.). The energy storage device 1 is a small energy storage box that can be mounted on an outdoor wall. Specifically, the electric energy conversion device 2 can convert solar energy into electrical energy during periods of low electricity prices, store it in the energy storage device 1, and then supply the user load 3 for use during peak electricity prices or during power outages.

[0051] In conjunction with the aforementioned physical or electrochemical energy storage, taking electrochemical energy storage as an example, the energy storage device 1 includes at least one set of chemical batteries, utilizing the chemical elements within the chemical batteries as the energy storage medium, with the charging and discharging process achieved through chemical reactions or changes in the energy storage medium. Simply put, the electrical energy generated by solar energy or wind energy is stored in the at least one set of chemical batteries through chemical reactions or changes in the energy storage medium. When external electrical energy usage reaches a peak, the energy stored in the at least one set of chemical batteries is released for use through chemical reactions or changes in the energy storage medium, or transferred to areas with power shortages for reuse.

[0052] The embodiments of the present application provide an energy storage device 1, which may be, but is not limited to, a single cell (secondary battery), a battery module composed of single cells, a battery pack, an energy storage cabinet, an energy storage container, and the like. The single cells may be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, and the like. The single cells may be cylindrical, flat, or rectangular, and the embodiments of the present application do not limit this. The following description will take the energy storage device 1 as an example, taking it as a rectangular single cell or a cylindrical single cell.

[0053] like Figure 2As shown, a schematic diagram of an exploded rectangular battery is shown. The energy storage device 1 includes a shell 100, an electrode assembly 200, a cover plate 300a and a seal 400. The shell 100 includes a accommodating cavity 110 with an opening 101, and the electrode assembly 200 is arranged in the accommodating cavity 110 of the shell 100 and has a tab 201. The cover plate 300a is located on the side where the tab 201 of the electrode assembly 200 is located, and is connected to the shell 100. In one embodiment, the cover plate 300a can be connected to the shell 100 by a welding process or a crimping process to seal the opening 101 of the shell 100. The cover plate 300a has an injection hole 340, and the injection hole 340 passes through the cover plate 300a along the thickness direction of the cover plate 300a. The seal 400 can be made of a metal material and welded to the cover plate 300a to seal the injection hole 340. It should be noted that, in the embodiment of the present application, the cover plate 300a is the top cover 300. In order to unify the terminology, in this embodiment, the cover plate 300a is taken as an example for description.

[0054] The housing 100 is a rectangular parallelepiped housing. Optionally, the housing 100 can be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0055] The electrode assembly 200 includes a positive electrode sheet, a negative electrode sheet, and a separator. A single battery primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive electrode collector. The uncoated positive electrode collector protrudes from the coated positive electrode collector, and the uncoated positive electrode collector serves as the positive electrode tab. For lithium-ion batteries, for example, the positive electrode collector can be made of aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative electrode collector. The uncoated negative electrode collector protrudes from the coated negative electrode collector, and the uncoated negative electrode collector serves as the negative electrode tab. The negative electrode collector can be made of copper, and the negative electrode active material can be carbon or silicon, among others. The material of the separator may be PP or PE, etc. In addition, the electrode assembly 200 may be a wound structure or a laminated structure, but the present invention is not limited thereto.

[0056] Please continue reading Figure 2The cover plate 300a is also provided with two poles 370 and an explosion-proof valve 380. The two poles 370 serve as the positive pole and the negative pole, respectively. The positive pole is connected to the positive tab of the electrode assembly 200, and the negative pole is connected to the negative tab of the electrode assembly 200. The explosion-proof valve 380 is designed to explode and discharge the gas generated in the accommodating cavity 110 of the housing 100 when the gas pressure of the energy storage device 1 reaches a certain pressure threshold, thereby preventing battery bulging or even explosion, thereby improving the safety of the energy storage device 1.

[0057] like Figures 3 to 5 As shown, the cover plate 300a is a rectangular plate structure made of a metal material, such as aluminum. The cover plate 300a has a first surface 301 facing the electrode assembly 200 and a second surface 302 facing away from the electrode assembly 200. The cover plate 300a also has a first recessed groove 310, a second recessed groove 320, and an injection hole 340. The first recessed groove 310 is recessed inward from the second surface 302, and the second recessed groove 320 is recessed inward from the bottom surface of the first recessed groove 310. The injection hole 340 extends through the bottom surface of the second recessed groove 320 and the first surface 301. The second recessed groove 320 is a tapered groove with a larger opening near the second surface 302. The sidewalls of the second recessed groove 320 have a first inner conical surface 321. The seal 400 includes a main body 410 and an annular flange 420. Part of the main body 410 is located in the second groove 320 and has a first outer conical surface 411 that cooperates with the first inner conical surface 321. The annular flange 420 is integrally surrounded by the outer peripheral side of the main body 410, overlaps the bottom surface of the first groove 310, and is welded to the cover plate 300a.

[0058] In the embodiment of the present application, the cover plate 300a has a first recessed groove 310 and a second recessed groove 320. The first recessed groove 310 is recessed inward from the second surface 302, while the second recessed groove 320 is recessed inward from the bottom of the first recessed groove 310. The injection hole 340 extends through the bottom of the second recessed groove 320 and the first surface 301, thereby forming a stepped surface around the injection hole 340. This increases the distance between the bottom of the first recessed groove 310 and the injection hole 340. During or after the injection process, electrolyte is less likely to spill onto the bottom of the first recessed groove 310. This reduces the risk of poor welding quality between the annular flange 420 and the cover plate 300a due to incomplete electrolyte cleaning, and prevents welding defects that could affect the sealing of the injection hole 340. Furthermore, the sidewall of the first recessed groove 310 has a first inner conical surface 321, and the main body 410 of the seal 400 has a first outer conical surface 411 that mates with the first inner conical surface 321. During assembly of the seal 400 and the cover plate 300a, the first inner conical surface 321 and the first outer conical surface 411 provide a guiding fit, making it easier for the seal 400 to align with the injection hole 340 of the cover plate 300a during assembly. This avoids the problem of inconsistent weld penetration caused by the seal 400 being misaligned relative to the cover plate 300a. Furthermore, because the main body 410 of the seal 400 is more easily inserted into the second recessed groove 320, automated assembly efficiency is improved. Consequently, while welding productivity is enhanced, welding quality is also improved.

[0059] like Figure 4 As shown, the annular flange 420 is welded to the side wall of the first sink 310 to form a first annular welding portion 510 , and the annular flange 420 is welded to the bottom wall of the first sink 310 to form a second annular welding portion 520 .

[0060] In this embodiment of the present application, a stepped surface is formed around the injection hole 340, making the thickness of the annular flange 420 smaller than the thickness of the entire seal 400, allowing for through-welding of the annular flange 420. Therefore, during welding, not only is a first annular weld 510 formed between the annular flange 420 and the sidewall of the first recessed groove 310, but a second annular weld 520 is also formed between the annular flange 420 and the bottom wall of the first recessed groove 310. The combined effect of the first and second annular welds 510, 520, improves the weld strength between the seal 400 and the cover plate 300a.

[0061] like Figure 4 As shown, the annular flange 420 has a first thickness t1, and the body 410 has a second thickness t2, and t1 and t2 satisfy 1 / 3≤t1 / t2≤1 / 2.

[0062] In the embodiment of the present application, by reducing the thickness of the annular flange 420 , the power requirement for the welding equipment can be reduced, the welding efficiency can be improved, and the cost can be saved.

[0063] like Figure 4 As shown, a side surface of the body 410 facing away from the liquid injection hole 340 and a side surface of the annular flange 420 facing away from the bottom surface of the first sink 310 are flush with the second surface 302 .

[0064] In the embodiment of the present application, by designing the side surface of the body 410 facing away from the liquid injection hole 340, the side surface of the annular flange 420 facing away from the bottom surface of the first trough 310, and the second surface 302 of the cover plate 300a to be flush, the flatness of the overall surface of the energy storage device 1 can be improved, thereby enhancing the aesthetics.

[0065] Of course, in other embodiments, the side surface of the annular flange 420 facing away from the bottom surface of the first sink 310 can be flush with the second surface 302 of the cover 300a, while the side surface of the body 410 facing away from the liquid injection hole 340 is slightly higher than the second surface 302.

[0066] like Figure 6 As shown, the structures of the sealing member 400 and the cover plate 300a of the second embodiment of the present application are similar to those of the first embodiment and are not described in detail. The differences are as follows:

[0067] The bottom surface of the first groove 310 has a sloped surface 311, which is connected to the groove side of the first groove 310 and extends from the groove side of the first groove 310 in a direction away from the second surface 302 and connected to the first inner conical surface 321; the annular flange 420 overlaps the sloped surface 311.

[0068] In the embodiment of the present application, the sloped surface 311 is connected to the side surface of the first trough 310, and extends from the side surface of the first trough 310 in a direction away from the second surface 302, and is connected to the first inner conical surface 321. That is, the end of the sloped surface 311 away from the injection hole 340 is higher, and the end of the sloped surface 311 close to the injection hole 340 is lower. In this way, when electrolyte drips into the first trough 310, the electrolyte can flow back into the injection hole 340 along the sloped surface 311 by its own gravity, preventing the electrolyte from accumulating on the bottom surface of the first trough 310, thereby ensuring the welding quality of the seal 400 and the cover plate 300a.

[0069] It can be understood that when the bottom surface of the first trough 310 has a slope surface 311, the side surface of the annular flange 420 facing the injection hole 340 has a surface that cooperates with the slope surface 311, so as to improve the fit between the annular flange 420 and the cover plate 300a after the annular flange 420 overlaps the bottom surface of the first trough 310.

[0070] In one embodiment, the slope surface 311 is an inner conical surface. Designing the slope surface 311 as an inner conical surface allows the electrolyte dripping into the first trough 310 to flow back to the injection hole 340 more easily and completely.

[0071] Among them, when the bottom surface of the first sink 310 is an inner conical surface, the shape of the lower surface of the annular flange 420 is adapted to the inner conical surface, that is, the lower surface of the annular flange 420 constitutes an outer conical surface to improve the fit between the annular flange 420 and the cover plate 300a.

[0072] In another embodiment, the bottom surface of the first sink 310 may have a plurality of slope surfaces 311 , and the plurality of slope surfaces 311 are arranged along the circumference of the liquid injection hole 340 , that is, the plurality of slope surfaces 311 form a pyramid shape.

[0073] In addition, the bottom surface of the first sink trough 310 may be entirely or partially a slope surface 311 .

[0074] like Figure 7 As shown, the structures of the sealing member 400 and the cover plate 300a of the third embodiment of the present application are similar to those of the above embodiments and are not described in detail. The differences are as follows:

[0075] The cover plate 300 a further has a third groove 330 , which is recessed inward from the bottom of the second groove 320 . The injection hole 340 passes through the bottom of the third groove 330 . Part of the body 410 is located in the third groove 330 .

[0076] In the embodiment of the present application, the cover plate 300a has a first groove 310, a second groove 320 and a third groove 330. The first groove 310 is recessed inward from the second surface 302, the second groove 320 is recessed inward from the bottom surface of the first groove 310, and the third groove 330 is recessed inward from the bottom surface of the second groove 320. The injection hole 340 passes through the bottom surface of the third groove 330, thereby forming two step surfaces around the injection hole 340, further increasing the distance between the bottom surface of the first groove 310 and the injection hole 340, thereby reducing the welding quality of the annular flange 420 and the cover plate 300a due to incomplete electrolyte cleaning, and avoiding affecting the sealing of the injection hole 340 due to welding defects.

[0077] In one embodiment, the third groove 330 is a conical groove, and the opening close to the second surface 302 is larger. The groove side wall of the third groove 330 has a second inner conical surface 331; the outer peripheral side surface of the body 410 has a second outer conical surface 412 that cooperates with the second inner conical surface 331.

[0078] In the embodiment of the present application, when assembling the seal 400 and the cover plate 300a, the second inner conical surface 331 and the second outer conical surface 412 provide a guiding fit, making it easier for the seal 400 to align with the liquid injection hole 340 of the cover plate 300a during assembly. This avoids the problem of inconsistent weld penetration caused by the seal 400 being misaligned relative to the cover plate 300a. Furthermore, since the body 410 of the seal 400 is more easily inserted into the third recess 330, the efficiency of automated assembly is improved. Therefore, while improving welding process capability, weld quality is also enhanced.

[0079] It can be understood that, in the absence of contradiction, the slope surface 311 of the second embodiment of the present application and the third sink groove 330 of the third embodiment can be combined, that is, not only the bottom surface of the first sink groove 310 of the cover plate 300a has the slope surface 311, but the cover plate 300a also has the third sink groove 330.

[0080] like Figure 8 As shown, a schematic diagram of a decomposition of a cylindrical battery is shown. The energy storage device 1 of the embodiment of the present application includes a shell 100, an electrode assembly 200, an end plate 600, a current collecting disc 300b and a seal 400. The shell 100 includes a accommodating cavity 110 having an opening 101, and the electrode assembly 200 is arranged in the accommodating cavity 110 of the shell 100. The end plate 600 is connected to the shell 100 and seals the opening 101 of the shell 100. The end plate 600 has a through hole 601, and the through hole 601 passes through the end plate 600 along the thickness direction of the end plate 600. It should be noted that, in the embodiment of the present application, the current collecting disc 300b is the top cover 300. In order to unify the terminology, in this embodiment, the current collecting disc 300b is taken as an example for explanation.

[0081] The current collecting plate 300b includes a coaxially arranged plate body 350 and a connecting portion 360. The plate body 350 is disposed between the end plate 600 and the electrode assembly 200 and is connected to the electrode tab 201 of the electrode assembly 200. The connecting portion 360 is connected to the plate body 350 and extends through the through-hole 601. The connecting portion 360 is connected to the end plate 600, for example, by welding. The surface of the connecting portion 360 facing the electrode assembly 200 is the first surface 301, and the surface of the connecting portion 360 facing away from the electrode assembly 200 is the second surface 302.

[0082] That is, in the embodiment of the present application, the connection portion 360 of the current collecting plate 300 b has a first sink 310 , a second sink 320 and a liquid injection hole 340 , and the sealing member 400 is welded to the connection portion 360 .

[0083] It is understandable that when the top cover 300 is a collecting plate 300b, the structure of the connection portion 360 between the sealing member 400 and the collecting plate 300b can be designed with reference to the structure of the cover plate 300a and the sealing member 400 in any of the above embodiments, which will not be repeated here.

[0084] like Figure 9 As shown, embodiments of the present application further provide an electrical device 4, which may be an energy storage device, a vehicle, an energy storage container, or the like. This electrical device 4 includes the energy storage device 1 described in the above embodiments, which supplies power to the electrical device 4. Thus, the electrical device 4 including the energy storage device 1 described above can improve the operational stability of the electrical device 4, reduce the probability of downtime of the electrical device 4, and improve the safety of the use of the electrical device 4.

[0085] It is understandable that the various embodiments / implementations provided in this application can be combined with each other without causing any contradiction, and they will not be illustrated one by one here.

[0086] In the application examples, 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 mean a fixed connection, a detachable connection, or an integral connection; "connected" can mean a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the application examples can be understood according to the specific circumstances.

[0087] In the description of the application embodiments, it should be understood that the terms "up", "down", "left", "right", "front", "back", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the application embodiments 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 direction. Therefore, they cannot be understood as limitations on the application embodiments.

[0088] 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 claimed invention. 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.

[0089] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An energy storage device, characterized in that: include: An electrode assembly having a tab; a top cover, located on a side of the electrode assembly where the electrode tab is located; The top cover has a first surface facing the electrode assembly and a second surface facing away from the electrode assembly. The top cover further has a first sink, a second sink, and a liquid injection hole. The first sink is recessed inward from the second surface, and the second sink is recessed inward from the bottom of the first sink. The liquid injection hole passes through the bottom of the second sink and the first surface. The second sink is a tapered groove with a larger opening near the second surface. The sidewall of the second sink has a first inner conical surface. as well as The sealing member includes a main body and an annular flange. Part of the main body is located in the second sink groove and has a first outer conical surface that cooperates with the first inner conical surface. The annular flange is integrally protruded on the outer peripheral side of the main body, overlaps the bottom surface of the first sink groove, and is welded to the top cover member.

2. The energy storage device according to claim 1, characterized in that The annular flange is welded to the side wall of the first sink groove to form a first annular welding portion, and the annular flange is welded to the bottom wall of the first sink groove to form a second annular welding portion.

3. The energy storage device according to claim 1, characterized in that The annular flange has a first thickness t1, and the body has a second thickness t2, and t1 and t2 satisfy 1 / 3≤t1 / t2≤1 / 2.

4. The energy storage device according to claim 1, characterized in that The bottom surface of the first sink has a sloped surface, the sloped surface is connected to the side surface of the first sink, extends from the side surface of the first sink in a direction away from the second surface, and is connected to the first inner conical surface; The annular flange overlaps the slope surface.

5. The energy storage device according to claim 4, characterized in that The slope surface is a conical surface.

6. The energy storage device according to claim 1, characterized in that A side surface of the body facing away from the liquid injection hole and a side surface of the annular flange facing away from the bottom surface of the first sink are flush with the second surface.

7. The energy storage device according to claim 1, characterized in that The top cover further comprises a third recessed groove, the third recessed groove being recessed inward from the bottom surface of the second recessed groove, and the injection hole passing through the bottom surface of the third recessed groove; Part of the body is located in the third sink.

8. The energy storage device according to claim 7, characterized in that The third groove is a tapered groove, and the opening close to the second surface is larger, and the groove sidewall of the third groove has a second inner conical surface; The outer peripheral side surface of the body has a second outer conical surface matched with the second inner conical surface.

9. The energy storage device according to claim 1, characterized in that The energy storage device further includes a housing, the housing includes a receiving cavity with an opening, the electrode assembly is disposed in the receiving cavity, the top cover is a cover plate of the energy storage device, the cover plate is connected to the housing, and seals the opening; or, The energy storage device also includes an outer shell and an end plate, the outer shell includes a accommodating cavity with an opening, the electrode assembly is arranged in the accommodating cavity, the end plate is connected to the outer shell and seals the opening; the end plate has a through hole, and the through hole passes through the end plate along the thickness direction of the end plate; the top cover is a current collecting disk of the energy storage device, and the current collecting disk includes a disk body and a connecting portion arranged coaxially, the disk body is arranged between the end plate and the electrode assembly, and is connected to the pole ear of the electrode assembly; the connecting portion is connected to the disk body and is passed through the through hole; the side surface of the connecting portion facing the electrode assembly is the first surface, and the side surface of the connecting portion facing away from the electrode assembly is the second surface.

10. An electrical device, characterized in that: The energy storage device comprises the energy storage device according to any one of claims 1 to 9, wherein the energy storage device supplies power to the electrical equipment.

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