Energy storage device and electric equipment

Abstract

The utility model discloses an energy storage device and electric equipment. The energy storage device comprises a shell, an electrode assembly, a cover plate and a current collecting disc. The shell comprises an accommodating cavity with an opening; the electrode assembly is accommodated in the accommodating cavity and is provided with a central hole; the cover plate is connected to the shell and seals the opening; the cover plate is provided with a via hole which penetrates through the cover plate along the thickness direction of the cover plate; the collector plate comprises a plate body, a connecting part and a positioning part which are coaxially arranged; the disc body is provided with a first surface facing the cover plate and a second surface facing the electrode assembly; the connecting part is connected with the disc body, at least part of the connecting part protrudes out of the first surface, and the connecting part is arranged in the via hole in a penetrating mode and connected with the cover plate; the positioning part is connected to one side surface, facing the electrode assembly, of the connecting part; the end, away from the connecting part, of the positioning part protrudes out of the second surface and is limited in the center hole in the thickness direction of the flow collecting disc; the flow collecting disc is further provided with a liquid injection hole, and the liquid injection hole penetrates through the connecting part and the positioning part in the thickness direction of the flow collecting disc.

Description

Technical Field

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

[0002] A battery includes a housing, an electrode assembly, a current collector plate, and a cover plate. During the assembly process, the current collector plate is first connected to the electrode assembly, then the cover plate is connected to the housing, and finally the assembled current collector plate and electrode assembly are inserted into the housing, and the current collector plate is connected to the cover plate. Among them, for the connection between the current collector plate and the cover plate, in the related art, the convex hull of the current collector plate is usually inserted into the through hole of the cover plate, and finally the convex hull is welded to the cover plate.

[0003] However, affected by factors such as equipment accuracy, part manufacturing tolerances, and process stability, the coaxiality after the assembly of the current collector plate and the electrode assembly is poor, which further causes the convex hull of the current collector plate to be difficult or even impossible to insert into the through hole of the cover plate, reducing the product yield. Utility Model Content

[0004] An embodiment of the present application provides an energy storage device and an electrical equipment that can ensure the coaxiality after the assembly of the current collector plate and the electrode assembly, and solves the technical problem that the convex hull of the current collector plate in the related art is difficult or even impossible to insert into the through hole of the cover plate.

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

[0006] A housing including a receiving cavity with an opening;

[0007] An electrode assembly received in the receiving cavity and having a central hole;

[0008] A cover plate connected to the housing and sealing the opening; the cover plate has a through hole that penetrates the cover plate along the thickness direction of the cover plate; and

[0009] A current collector plate disposed between the cover plate and the electrode assembly, the current collector plate includes a disk body, a connecting portion, and a positioning portion arranged coaxially; the disk body has a first surface facing the cover plate and a second surface facing the electrode assembly; the connecting portion is connected to the disk body, and at least a part of the connecting portion protrudes from the first surface, the connecting portion passes through the through hole and is connected to the cover plate; the positioning portion is connected to a surface of the connecting portion facing the electrode assembly; along the thickness direction of the current collector plate, one end of the positioning portion away from the connecting portion protrudes from the second surface and is limited in the central hole;

[0010] Wherein, the current collector plate further has a liquid injection hole that penetrates the connecting portion and the positioning portion along the thickness direction of the current collector plate.

[0011] When assembling the energy storage device according to the embodiments of the present application, generally speaking, it can be divided into three steps. The first step is to weld the current collector plate to the electrode assembly. The second step is to weld the cover plate to the housing. The third step is to insert the current collector plate and the electrode assembly into the housing from the end of the housing away from the cover plate, and insert the connecting portion of the current collector plate into the through hole of the cover plate. Finally, weld the connecting portion to the cover plate. Among them, since the current collector plate has a positioning portion and the electrode assembly has a central hole, when welding the current collector plate to the electrode assembly, the positioning portion can be first inserted into the central hole for pre-positioning, and then the current collector plate and the electrode assembly are welded. In this way, when welding the current collector plate and the electrode assembly, the coaxiality of the current collector plate and the electrode assembly can be avoided being affected by factors such as equipment accuracy, part manufacturing tolerance, and process stability, and further ensure that the connecting portion of the current collector plate can be accurately inserted into the through hole of the cover plate, which is beneficial to improving the assembly efficiency of the energy storage device.

[0012] Optionally, along the thickness direction of the current collector plate, one end of the positioning portion away from the connecting portion has a first frustum of a cone, and the top surface of the first frustum of the cone faces away from the connecting portion.

[0013] In the embodiments of the present application, one end of the positioning portion away from the connecting portion has a first frustum of a cone, and the top surface of the first frustum of the cone faces away from the connecting portion. When assembling the current collector plate and the electrode assembly, the outer peripheral side surface of the first frustum of the cone can play a guiding role, making it easier for the positioning portion to align with the central hole of the electrode assembly, and then the positioning portion is easier to insert into the central hole.

[0014] Optionally, the positioning portion further includes a frustum and a second frustum of a cone. The frustum, the first frustum of the cone, and the second frustum of the cone are coaxially arranged. The second frustum of the cone is connected to the connecting portion, and the frustum is connected between the bottom surface of the first frustum of the cone and the top surface of the second frustum of the cone; the size of the top surface of the second frustum of the cone is greater than or equal to the size of the bottom surface of the first frustum of the cone.

[0015] In the embodiments of the present application, the positioning portion includes a first frustum of a cone, a frustum, and a second frustum of a cone that are coaxially arranged. The frustum is connected between the bottom surface of the first frustum of the cone and the top surface of the second frustum of the cone. The size of the top surface of the second frustum of the cone is greater than or equal to the size of the bottom surface of the first frustum of the cone. The root size of the positioning portion is larger, thereby improving the structural strength of the positioning portion and avoiding accidental breakage of the positioning portion when the positioning portion is inserted into the central hole of the electrode assembly.

[0016] Optionally, the liquid injection hole includes a first hole and a second hole that are connected to each other and coaxially arranged. The aperture of the first hole is smaller than the aperture of the second hole;

[0017] The first hole is formed inside the first frustum of the cone, and the second hole is formed inside the frustum and the second frustum of the cone.

[0018] Optionally, one side of the current collector plate facing the electrode assembly has a groove, and the positioning portion protrudes from the bottom surface of the groove; the positioning portion has a communication hole, the communication hole communicates with the liquid injection hole, penetrates through the outer peripheral side surface of the positioning portion, and communicates with the groove.

[0019] In the embodiment of the present application, the positioning portion has a communication hole, the communication hole communicates with the groove, and communicates with the central hole of the electrode assembly through the liquid injection hole. On the one hand, when the energy storage device is in different postures, the electrolyte in the central hole of the electrode assembly can flow into the groove through the liquid injection hole and the communication hole, ensuring the reflux of the electrolyte; on the other hand, the gas generated inside the electrode assembly can also flow into the groove through the liquid injection hole and the communication hole, avoiding the gas inside the electrode assembly from being unable to be discharged due to the positioning portion blocking the central hole.

[0020] Optionally, the number of the communication holes is multiple, and the multiple communication holes are arranged at equal intervals along the circumferential direction of the positioning portion.

[0021] In the embodiment of the present application, a plurality of communication holes are arranged at equal intervals on the outer periphery of the positioning portion, which can ensure that the gas and / or electrolyte in the electrode assembly flow into the groove evenly.

[0022] Optionally, one of the cover plate and the disk body of the current collector plate is provided with a positioning protrusion, and the other is provided with a positioning groove, and the positioning protrusion is limited in the positioning groove.

[0023] In the embodiment of the present application, the positioning protrusion and the positioning groove are in positioning cooperation. Therefore, in the circumferential direction of the connecting portion, the relative position between the cover plate and the current collector plate is fixed, avoiding relative rotation between the current collector plate and the cover plate when welding the connecting portion of the current collector plate and the cover plate, and ensuring the reliability of the connection between the connecting portion and the cover plate.

[0024] Optionally, the energy storage device further includes an explosion-proof valve, which is connected to the cover plate; the disk body of the current collector plate has a welding portion connected to the electrode assembly and an exhaust hole penetrating through the disk body. Along the thickness direction of the current collector plate, the position of the exhaust hole corresponds to the position of the explosion-proof valve; the positive projections of the welding portion and the explosion-proof valve on a target plane do not overlap with each other, and the target plane is perpendicular to the thickness direction of the current collector plate.

[0025] In the embodiment of the present application, since there is no overlapping part between the first projection and the third projection, the welding portion does not block the explosion-proof valve, ensuring that the energy storage device has a sufficiently large exhaust channel, so that the gas in the housing can be quickly and timely discharged from the housing.

[0026] Optionally, the number of the welding parts is multiple, and the multiple welding parts are arranged along the circumferential direction of the current collector plate. The length direction of the welding part is parallel to the radial direction of the current collector plate, and the orthographic projection of the welding part on the target plane is a first projection, and the orthographic projection of the connecting part on the target plane is a second projection. The first projection and the second projection are arranged at intervals.

[0027] It should be noted that in order to prevent the welding part from blocking the explosion-proof valve, the distance between two adjacent welding parts cannot be too close in the circumferential direction of the current collector plate. Therefore, the size of the welding part along the circumferential direction of the current collector plate cannot be too large. In order to meet the current-carrying area after the current collector plate is welded to the electrode assembly, the size of the welding part along the radial direction of the current collector plate needs to be as long as possible. However, when the welding part is too long and contacts the connecting part, the heat generated during the welding of the welding part to the electrode assembly will be conducted to the connecting part, which will cause the connecting part to deform due to heat, and the dimensional accuracy of the deformed connecting part will be affected, and it is easy to have the problem that it cannot be inserted into the through hole of the cover plate.

[0028] In the embodiment of the present application, since there are matching positioning protrusions and positioning grooves between the current collector plate and the cover plate, the assembly angle between the current collector plate and the cover plate is limited, and at this assembly angle, the position of the welding part will not block the explosion-proof valve, so the size of the welding part along the circumferential direction of the current collector plate can be increased. Due to the size of the welding part along the circumferential direction of the current collector plate, on the premise of meeting the current-carrying area, the size of the welding part along the radial direction of the current collector plate can be appropriately reduced. Therefore, the welding part and the connecting part can be arranged at intervals to reduce the risk of deformation of the connecting part due to heat.

[0029] Optionally, there is a shortest distance L1 between the first projection and the second projection, and along the radial direction of the current collector plate, the first projection has a longest distance L2; wherein, L1 and L2 satisfy: L2 / 3 ≤ L1 ≤ L2 / 2.

[0030] In the embodiment of the present application, by limiting the distance between the first projection and the second projection to L2 / 3 ≤ L1 ≤ L2 / 2, the distance between the welding part and the connecting part is further increased, and the risk of deformation of the connecting part due to heat is reduced.

[0031] Optionally, the orthographic projection of the welding part on the target plane is a first projection, and the first projection is in a fan shape.

[0032] In the embodiment of the present application, the first projection is in a fan shape, which can further increase the area of the welding part. On the premise of ensuring that the welding part does not block the explosion-proof valve, the area of the welding part can be maximized to increase the current-carrying area after the welding part is welded to the electrode assembly.

[0033] Optionally, the central angle of the fan shape is between 60° and 300°.

[0034] The electrical equipment of the embodiment of the present application includes the energy storage device described in any one of the above, and the energy storage device supplies power to the electrical equipment. Description of the Drawings

[0035] Figure 1 The figure shows a schematic structural diagram of a household energy storage system.

[0036] Figure 2 The figure shows an exploded schematic diagram of the energy storage device of the embodiment of the present application.

[0037] Figure 3 The figure shows a three-dimensional schematic diagram of the current collector plate of the first embodiment of the present application from one perspective.

[0038] Figure 4 The figure shows a three-dimensional schematic diagram of the current collector plate of the first embodiment of the present application from another perspective.

[0039] Figure 5 The figure shows a top view schematic diagram of the energy storage device of the embodiment of the present application.

[0040] Figure 6 The figure shows along Figure 5 the cross-sectional view obtained along the A-A cutting line.

[0041] Figure 7 The figure shows Figure 6 the partial enlarged view of X1.

[0042] Figure 8 The figure shows a three-dimensional schematic diagram of the cover plate of the embodiment of the present application.

[0043] Figure 9 The figure shows a schematic diagram of the positional relationship among the first projection, the second projection, and the third projection of an embodiment of the present application.

[0044] Figure 10 The figure shows a three-dimensional schematic diagram of the current collector plate of the second embodiment of the present application.

[0045] Figure 11 The figure shows a schematic diagram of the positional relationship among the first projection, the second projection, and the third projection of another embodiment of the present application.

[0046] Figure 12 The figure shows a three-dimensional schematic diagram of the current collector plate of the third embodiment of the present application.

[0047] Figure 13 The figure shows a schematic diagram of the positional relationship among the first projection, the second projection, and the third projection of yet another embodiment of the present application.

[0048] Figure 14 The figure shows a schematic diagram of the electrical equipment of the embodiment of the present application.

[0049] Among them, the reference numerals are explained as follows:

[0050] 1. Energy storage device; 2. Electric energy conversion device; 3. User load; 4. Electrical equipment;

[0051] 100. Housing; 101. Opening; 110. Accommodation cavity;

[0052] 200. Electrode assembly; 201. Central hole;

[0053] 300. Cover plate; 301. Through hole; 302. Positioning groove; 303. Pressure relief hole; 304. Second chamfer;

[0054] 400. Current collector plate; 401. Liquid injection hole; 401a. First hole; 401b. Second hole; 401c. Third hole; 402. Groove; 410. Plate body; 411. First surface; 412. Second surface; 413. Welding part; 414. Exhaust hole; 420. Connection part; 421. Base; 421a. Step surface; 422. Extension part; 423. Top; 430. Positioning part; 431. Communication hole; 432. First frustum; 433. Frustum; 434. Second frustum; 440. Positioning protrusion; 441. First chamfer;

[0055] 500. Explosion-proof valve;

[0056] 600. Sealing member. Detailed implementation manners

[0057] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote the same or similar structures, and thus their detailed descriptions will be omitted.

[0058] It can be understood that the terms "including" and "having" and any variations thereof in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or components inherent to these processes, methods, products or devices.

[0059] Since the energy required by people has strong temporality and spatiality, in order to rationally utilize energy and improve the energy utilization rate, it is necessary to store one form of energy in the same or converted into another form of energy through a medium or device, and then release it in a specific energy form based on future application needs.

[0060] Currently, the application scenarios of energy storage (i.e., energy storage) are relatively extensive, including energy storage on the power generation side, energy storage on the grid side, energy storage for renewable energy grid connection, and energy storage on the user side, etc. The types of corresponding energy storage devices include:

[0061] (1) Large energy storage containers applied in the energy storage scenario on the grid side can serve as high-quality active and reactive power regulation power sources in the grid, achieving load matching of electric energy in terms of time and space, enhancing the consumption capacity of renewable energy, and being of great significance in grid system standby, alleviating the power supply pressure during peak loads, and peak shaving and frequency modulation.

[0062] (2) Small and medium-sized energy storage cabinets applied in the industrial and commercial energy storage scenarios (such as banks, shopping malls, etc.) on the user side and household small energy storage boxes applied in the household energy storage scenarios on the user side mainly operate in the mode of "peak shaving and valley filling". Since there is a large price difference in electricity charges at peak and valley positions according to the electricity consumption demand, after users have energy storage devices, in order to reduce costs, they usually charge the energy storage cabinet / box during the low electricity price period; during the peak electricity price period, the electricity in the energy storage device is released for use to achieve the purpose of saving electricity charges. In addition, in remote areas and areas with high incidences of natural disasters such as earthquakes and hurricanes, the existence of household energy storage devices is equivalent to users providing backup power for themselves and the grid, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0063] Taking the household energy storage scenario in user-side energy storage as an example for illustration, Figure 1 Fig. shows a household energy storage system, which includes an energy storage device 1 and an electric energy conversion device 2 (such as a photovoltaic panel), as well as a user load 3 (such as street lights, household appliances, etc.). The energy storage device 1 is a small energy storage box that can be installed on an outdoor wall in a wall-mounted manner. Specifically, the electric energy conversion device 2 can convert solar energy into electric energy during the low electricity price period and store it through the energy storage device 1, and then supply it to the user load 3 for use during the peak electricity price period, or supply it to the user load 3 for use when the grid is powered off / out of power.

[0064] Regarding the above-mentioned situation of energy storage by physical or electrochemical means, taking electrochemical energy storage as an example, the energy storage device 1 includes at least one group of chemical batteries, using the chemical elements in the chemical batteries as energy storage media to achieve the charging and discharging process through chemical reactions or changes of the energy storage media. Simply put, the electrical energy generated by light energy and wind energy is stored in at least one group of chemical batteries through chemical reactions or changes of the energy storage media, and when the use of external electrical energy reaches the peak, the stored electrical energy in at least one group of chemical batteries is released through chemical reactions or changes of the energy storage media for use, or transferred to places with a shortage of electrical energy for reuse.

[0065] An embodiment of the present application provides an energy storage device 1, which may be, but is not limited to, a single battery (secondary battery), a battery module, a battery pack, a battery system, etc. composed of single batteries. For a single battery, it may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc. The single battery may be in a cylindrical shape, a flat shape, a cuboid shape, etc., and the embodiments of the present application do not make specific limitations in this regard. Next, taking the energy storage device 1 as a cylindrical battery as an example, the energy storage device 1 will be explained in detail.

[0066] As Figure 2 shown, the energy storage device 1 of the embodiment of the present application includes a housing 100, an electrode assembly 200, a current collector plate 400, a cover plate 300, an explosion-proof valve 500, and a seal 600. The housing 100 includes a receiving cavity 110 having an opening 101, and the electrode assembly 200 is received in the receiving cavity 110. The cover plate 300 is connected to the housing 100 and closes the opening 101 of the receiving cavity 110. In one embodiment, the cover plate 300 and the housing 100 may be hermetically connected by welding; of course, in other embodiments, the cover plate 300 and the housing 100 may also be hermetically connected by a hemming process, and the present application does not make special limitations in this regard. The current collector plate 400 is disposed between the electrode assembly 200 and the cover plate 300 and is respectively connected to the electrode assembly 200 and the cover plate 300.

[0067] In one embodiment, the housing 100 may be a cylindrical structure. Optionally, the housing 100 may be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0068] Among them, the electrode assembly 200 includes a positive electrode sheet, a negative electrode sheet, and a separator. The monomer battery mainly operates by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector without the coated positive electrode active material layer protrudes from the positive electrode current collector with the coated positive electrode active material layer. The positive electrode current collector without the coated positive electrode active material layer serves as the positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector without the coated negative electrode active material layer protrudes from the negative electrode current collector with the coated negative electrode active material layer. The negative electrode current collector without the coated negative electrode active material layer serves as the negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. The material of the separator can be PP or PE, etc. In addition, the electrode assembly 200 can be a wound structure or a stacked structure, and the embodiments of the present application are not limited thereto.

[0069] As Figure 2 shown, the electrode assembly 200 has a central hole 201, and the axis of the central hole 201 coincides with the axis of the electrode assembly 200. Among them, in one embodiment, the central hole 201 can penetrate the electrode assembly 200 along the thickness direction of the cover plate 300; in another embodiment, the central hole 201 can also be a blind hole.

[0070] Please continue to refer to Figure 2 , the cover plate 300 has a pressure relief hole 303, and the pressure relief hole 303 penetrates the cover plate 300 along the thickness direction of the cover plate 300. The explosion-proof valve 500 is connected to the cover plate 300 and closes the pressure relief hole 303. The explosion-proof valve 500 is used to burst and discharge the gas generated in the accommodation cavity 110 of the housing 100 when the air pressure of the energy storage device 1 reaches a certain pressure threshold, so as to avoid battery bulging or even explosion, thereby improving the safety of the energy storage device 1.

[0071] As Figures 3 to 6As shown in the figure, the current collector plate 400 includes a plate body 410, a connecting portion 420, and a positioning portion 430 that are coaxially arranged. The plate body 410 has a first surface 411 and a second surface 412, and the first surface 411 and the second surface 412 are arranged opposite to each other along the thickness direction of the current collector plate 400. Among them, the first surface 411 faces the cover plate 300, and the second surface 412 faces the electrode assembly 200. The connecting portion 420 is connected to the plate body 410, and at least a part of the connecting portion 420 protrudes from the first surface 411; the positioning portion 430 is connected to one side surface of the connecting portion 420 facing the electrode assembly 200, and along the thickness direction of the current collector plate 400, one end of the positioning portion 430 away from the connecting portion 420 protrudes from the second surface 412; among them, the current collector plate 400 further has a liquid injection hole 401, and the liquid injection hole 401 penetrates through the connecting portion 420 and the positioning portion 430 along the thickness direction of the current collector plate 400. The electrolyte can be injected into the accommodation cavity 110 of the housing 100 through the liquid injection hole 401. After the injection of the electrolyte is completed, a seal 600 (such as Figure 2 ) can be used to seal the liquid injection hole 401 to prevent the electrolyte from leaking.

[0072] As Figure 2 and Figure 7 shown in the figure, the cover plate 300 has a through hole 301 that is coaxially arranged with the liquid injection hole 401, and the through hole 301 penetrates through the cover plate 300 along the thickness direction of the cover plate 300. The positioning portion 430 of the current collector plate 400 is limited in the central hole 201, and the connecting portion 420 of the current collector plate 400 passes through the through hole 301 and is connected to the cover plate 300.

[0073] It can be understood that when assembling the energy storage device 1 of the present application embodiment, generally speaking, it can be divided into three steps. The first step is to weld the current collector plate 400 and the electrode assembly 200, the second step is to weld the cover plate 300 and the housing 100, and the third step is to insert the current collector plate 400 and the electrode assembly 200 into the housing 100 from the end of the housing 100 away from the cover plate 300, and make the connecting portion 420 of the current collector plate 400 insert into the through hole 301 of the cover plate 300, and finally weld the connecting portion 420 and the cover plate 300.

[0074] Among them, since the current collector plate 400 has a positioning portion 430 and the electrode assembly 200 has a central hole 201, when welding the current collector plate 400 and the electrode assembly 200, the positioning portion 430 can be first inserted into the central hole 201 for pre-positioning, and then the current collector plate 400 and the electrode assembly 200 are welded. In this way, when welding the current collector plate 400 and the electrode assembly 200, the coaxiality of the current collector plate 400 and the electrode assembly 200 can be prevented from being affected by factors such as equipment accuracy, part manufacturing tolerance, and process stability, and further ensure that the connecting portion 420 of the current collector plate 400 can be accurately inserted into the through hole 301 of the cover plate 300, which is beneficial to improving the assembly efficiency of the energy storage device 1.

[0075] As Figure 3 and Figure 7 shown, the disk body 410 is annular and integrally surrounds the outer peripheral surface of the connecting portion 420. The connecting portion 420 has a base portion 421, an extension portion 422, and a top portion 423. The disk body 410 integrally surrounds the outer peripheral surface of the base portion 421. The extension portion 422 is connected to the base portion 421 and extends from the base portion 421 in a direction away from the first surface 411 and toward the axis of the liquid injection hole 401. The top portion 423 is connected to one end of the extension portion 422 away from the base portion 421. In the thickness direction of the current collecting disk 400, the liquid injection hole 401 penetrates through the top portion 423.

[0076] Wherein, a stepped surface 421a is formed on the surface of the base portion 421 facing away from the first surface 411, and the cover plate 300 abuts against the stepped surface 421a. The top portion 423 and the extension portion 422 pass through the through hole 301 of the cover plate 300.

[0077] Optionally, a groove 402 is formed on one side of the connecting portion 420 facing the electrode assembly 200, and a positioning portion 430 protrudes from the bottom surface of the groove 402.

[0078] Of course, in other embodiments, the connecting portion 420 may also be of other shapes, such as cylindrical.

[0079] As Figure 4 and Figure 7 shown, the positioning portion 430 includes a first frustum of a cone 432, a frustum 433, and a second frustum of a cone 434 that are coaxially arranged. The second frustum of a cone 434 is connected to the top portion 423 of the connecting portion 420, and the frustum 433 is connected between the bottom surface of the first frustum of a cone 432 and the top surface of the second frustum of a cone 434. In other words, in the thickness direction of the current collecting disk 400, one end of the positioning portion 430 away from the connecting portion 420 has a first frustum of a cone 432, and the top surface of the first frustum of a cone 432 faces away from the connecting portion 420.

[0080] Wherein, the size of the top surface of the second frustum of a cone 434 is greater than or equal to the size of the bottom surface of the first frustum of a cone 432.

[0081] In the embodiment of the present application, one end of the positioning portion 430 away from the connecting portion 420 has a first frustum of a cone 432, and the top surface of the first frustum of a cone 432 faces away from the connecting portion 420. When assembling the current collecting disk 400 and the electrode assembly 200, the outer peripheral side surface of the first frustum of a cone 432 can play a guiding role, making it easier for the positioning portion 430 to align with the central hole 201 of the electrode assembly 200, and thus making it easier for the positioning portion 430 to be inserted into the central hole 201.

[0082] In addition, the positioning portion 430 includes a first frustum 432, a frustum 433, and a second frustum 434 that are coaxially arranged. The frustum 433 is connected between the bottom surface of the first frustum 432 and the top surface of the second frustum 434. The size of the top surface of the second frustum 434 is greater than or equal to the size of the bottom surface of the first frustum 432. The root size of the positioning portion 430 is relatively large, thereby improving the structural strength of the positioning portion 430 and preventing the positioning portion 430 from accidentally breaking when inserted into the central hole 201 of the electrode assembly 200.

[0083] As Figure 7 shown, the liquid injection hole 401 includes a first hole 401a, a second hole 401b, and a third hole 401c that are interconnected and coaxially arranged. The second hole 401b is disposed between the first hole 401a and the third hole 401c. The aperture of the first hole 401a is smaller than the aperture of the second hole 401b, and the aperture of the second hole 401b is equal to the aperture of the third hole 401c. The first hole 401a is formed inside the first frustum 432, the second hole 401b is formed inside the frustum 433 and the second frustum 434, and the third hole 401c is formed inside the top portion 423 of the connecting portion 420.

[0084] As Figure 4 and Figure 7 shown, the frustum 433 of the positioning portion 430 has a communication hole 431. The communication hole 431 communicates with the second hole 401b of the liquid injection hole 401 and penetrates through the outer peripheral side surface of the frustum 433, so that the liquid injection hole 401 communicates with the groove 402 through the communication hole 431.

[0085] In the embodiment of the present application, the positioning portion 430 has a communication hole 431. The communication hole 431 communicates with the groove 402 and communicates with the central hole 201 of the electrode assembly 200 through the liquid injection hole 401. On the one hand, when the energy storage device 1 is in different postures, the electrolyte in the central hole 201 of the electrode assembly 200 can flow into the groove 402 through the liquid injection hole 401 and the communication hole 431, ensuring the reflux of the electrolyte. On the other hand, the gas generated inside the electrode assembly 200 can also flow into the groove 402 through the liquid injection hole 401 and the communication hole 431, preventing the gas inside the electrode assembly 200 from being unable to be discharged due to the positioning portion 430 blocking the central hole 201.

[0086] The number of the communication holes 431 is multiple, and the multiple communication holes 431 are arranged at equal intervals along the circumferential direction of the positioning portion 430.

[0087] In the embodiment of the present application, a plurality of communication holes 431 are arranged at equal intervals on the outer periphery of the positioning portion 430, which can ensure that the gas and / or electrolyte in the electrode assembly 200 flow into the groove 402 evenly.

[0088] As Figure 3 andFigure 8 As shown, one of the cover plate 300 and the disk body 410 of the current collector plate 400 is provided with a positioning protrusion 440, and the other is provided with a positioning groove 302, and the positioning protrusion 440 is limited within the positioning groove 302. For example, the cover plate 300 has the positioning groove 302, and the current collector plate 400 has the positioning protrusion 440; or, the cover plate 300 has the positioning protrusion 440, and the current collector plate 400 has the positioning groove 302.

[0089] In the embodiment of the present application, the positioning protrusion 440 and the positioning groove 302 are in positioning cooperation. Therefore, in the circumferential direction of the connecting portion 420, the relative positions between the cover plate 300 and the current collector plate 400 are fixed, avoiding relative rotation between the current collector plate 400 and the cover plate 300 when welding the connecting portion 420 of the current collector plate 400 and the cover plate 300, and ensuring the reliability of the connection between the connecting portion 420 and the cover plate 300.

[0090] In an embodiment, the positioning protrusion 440 has a first chamfer 441 and / or the positioning groove 302 has a second chamfer 304. In this way, the positioning protrusion 440 can be inserted into the positioning groove 302 more smoothly, avoiding jamming.

[0091] Wherein, the first chamfer 441 and the second chamfer 304 can be an R angle or a C angle. For example, the first chamfer 441 is an R angle, and the second chamfer 304 is a C angle; or, the first chamfer 441 is a C angle, and the second chamfer 304 is an R angle; or, both the first chamfer 441 and the second chamfer 304 are R angles; or, both the first chamfer 441 and the second chamfer 304 are C angles.

[0092] As Figure 3 shown, the disk body 410 of the current collector plate 400 has a welding portion 413 connected to the electrode assembly 200 and an exhaust hole 414 penetrating through the disk body 410. Along the thickness direction of the current collector plate 400, the position of the exhaust hole 414 corresponds to the position of the explosion-proof valve 500.

[0093] In an embodiment, the disk body 410 of the current collector plate 400 has a plurality of welding portions 413, and the plurality of welding portions 413 are arranged along the circumferential direction of the current collector plate 400, and each welding portion 413 extends along the radial direction of the current collector plate 400 (that is, the length direction of the welding portion 413 is parallel to the radial direction of the current collector plate 400). For example, the number of the welding portions 413 can be three, but not limited thereto.

[0094] As Figure 9 shown, the orthographic projection of the welding portion 413 on a target plane is a first projection S1, the orthographic projection of the connecting portion 420 on the target plane is a second projection S2, and the orthographic projection of the explosion-proof valve 500 on the target plane is a third projection S3. There is no overlapping part between the first projection S1 and the third projection S3. Wherein, the target plane is perpendicular to the thickness direction of the current collector plate 400.

[0095] In the embodiment of the present application, since there is no overlapping part between the first projection S1 and the third projection S3, the welding part 413 will not block the explosion-proof valve 500, ensuring that the energy storage device 1 has a sufficiently large exhaust passage, so that the gas in the housing 100 can be quickly and timely discharged from the housing 100.

[0096] As Figure 9 shown, the first projection S1 and the second projection S2 are arranged at intervals.

[0097] It should be noted that, in order to avoid the welding part 413 blocking the explosion-proof valve 500, in the circumferential direction of the current collector plate 400, the distance between two adjacent welding parts 413 cannot be too close, so the size of the welding part 413 in the circumferential direction of the current collector plate 400 cannot be too large. And in order to meet the current-carrying area after the current collector plate 400 is welded to the electrode assembly 200, the size of the welding part 413 in the radial direction of the current collector plate 400 needs to be as long as possible. However, when the welding part 413 is too long and contacts the connecting part 420, the heat generated during the welding of the welding part 413 to the electrode assembly 200 will be conducted to the connecting part 420, thereby causing the connecting part 420 to deform due to heat, and the dimensional accuracy of the deformed connecting part 420 is affected, and it is easy to have the problem that it cannot be inserted into the through hole 301 of the cover plate 300.

[0098] In the embodiment of the present application, since there are matching positioning protrusions 440 and positioning grooves 302 provided between the current collector plate 400 and the cover plate 300, the assembly angle between the current collector plate 400 and the cover plate 300 is limited, and at this assembly angle, the position of the welding part 413 will not block the explosion-proof valve 500, so the size of the welding part 413 in the circumferential direction of the current collector plate 400 can be increased. Since the size of the welding part 413 in the circumferential direction of the current collector plate 400, on the premise of meeting the current-carrying area, the size of the welding part 413 in the radial direction of the current collector plate 400 can be appropriately reduced, so the welding part 413 and the connecting part 420 can be arranged at intervals to reduce the risk of the connecting part 420 deforming due to heat.

[0099] Furthermore, as Figure 10 and Figure 11 shown, the same parts of the current collector plate 400 in the second embodiment of the present application and the current collector plate 400 in the above embodiment will not be described in detail. The differences are as follows:

[0100] The orthographic projection of the welding part 413 on the target plane is the first projection S1, and the orthographic projection of the connecting part 420 on the target plane is the second projection S2. There is a shortest distance L1 between the first projection S1 and the second projection S2; along the radial direction of the current collector plate 400, the first projection S1 has the longest distance L2; wherein, L1 and L2 satisfy: L2 / 3 ≤ L1 ≤ L2 / 2.

[0101] In the embodiment of the present application, by limiting the distance between the first projection S1 and the second projection S2 to L2 / 3 ≤ L1 ≤ L2 / 2, the distance between the welding portion 413 and the connecting portion 420 is further increased, reducing the risk of deformation of the connecting portion 420 caused by heat.

[0102] In addition, in the embodiment of the present application, since the size of the welding portion 413 in the radial direction of the current collector plate 400 is further reduced, in order to ensure the current-carrying area after welding the welding portion 413 and the electrode assembly 200, the size of the welding portion 413 in the circumferential direction of the current collector plate 400 can be appropriately increased.

[0103] As Figure 12 and Figure 13 shown, the same parts of the current collector plate 400 in the third embodiment of the present application and the current collector plate 400 in the above embodiment will not be described in detail. The differences are as follows:

[0104] The orthographic projection formed by the welding portion 413 on the target plane is the first projection S1, and the first projection S1 is in the shape of a fan.

[0105] In the embodiment of the present application, the first projection S1 is in the shape of a fan, which can further increase the area of the welding portion 413. On the premise that the welding portion 413 does not block the explosion-proof valve 500, the area of the welding portion 413 can be maximized to increase the current-carrying area after welding the welding portion 413 and the electrode assembly 200.

[0106] Furthermore, the central angle α of the fan shape is between 60° and 300°, for example, α is 60°, 90°, 100°, 120°, 150°, 180°, 210°, 240°, 270°, 300°.

[0107] As Figure 14 shown, the embodiment of the present application also provides an electrical device 4, which can be an energy storage device, a vehicle, an energy storage container, etc. The electrical device 4 includes the energy storage device 1 described in the above embodiment, and the energy storage device 1 supplies power to the electrical device 4. In this way, for the electrical device 4 including the energy storage device 1 described above, the working stability of the electrical device 4 can be improved, the probability of the electrical device 4 crashing can be reduced, and the safety of using the electrical device 4 can be improved at the same time.

[0108] It can be understood that the various embodiments / implementations provided in the present application can be combined with each other without contradiction, and no further examples will be given here.

[0109] In the embodiments of the application, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance; the term "plural" means two or more, unless otherwise clearly defined. Terms such as "installed", "connected", "joined", "fixed" and the like should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "joined" 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 application can be understood according to specific circumstances.

[0110] In the description of the embodiments of the application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the application and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the embodiments of the application.

[0111] In the description of this specification, the descriptions of terms such as "one embodiment", "some embodiments", "specific embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0112] The above are only the preferred embodiments of the embodiments of the application and are not used to limit the embodiments of the application. For those skilled in the art, the embodiments of the application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the application shall be included in the protection scope of the embodiments of the application.

Claims

1. An energy storage device, characterized in that: include: A housing, comprising a receiving cavity having an opening; An electrode assembly is accommodated in the accommodating cavity and has a central hole; A cover plate connected to the housing and sealing the opening; the cover plate has a through hole, and the through hole penetrates the cover plate along the thickness direction of the cover plate; as well as A current collecting disk is arranged between the cover plate and the electrode assembly, and the current collecting disk comprises a disk body, a connecting portion and a positioning portion arranged coaxially; the disk body has a first surface facing the cover plate and a second surface facing the electrode assembly; the connecting portion is connected to the disk body, and at least part of the connecting portion protrudes from the first surface, the connecting portion is penetrated in the through hole and connected to the cover plate; the positioning portion is connected to a side surface of the connecting portion facing the electrode assembly; along the thickness direction of the current collecting disk, one end of the positioning portion away from the connecting portion protrudes from the second surface and is limited in the center hole; Wherein, the current collecting plate further has a liquid injection hole, and the liquid injection hole penetrates the connecting portion and the positioning portion along the thickness direction of the current collecting plate.

2. The energy storage device according to claim 1, characterized in that: Along the thickness direction of the collecting plate, one end of the positioning portion away from the connecting portion has a first truncated cone, and the top surface of the first truncated cone faces away from the connecting portion.

3. The energy storage device according to claim 2, characterized in that: The positioning portion further includes a truncated cone and a second truncated cone, wherein the truncated cone, the first truncated cone, and the second truncated cone are coaxially arranged, the second truncated cone is connected to the connecting portion, and the truncated cone is connected between the bottom surface of the first truncated cone and the top surface of the second truncated cone; The size of the top surface of the second truncated cone is greater than or equal to the size of the bottom surface of the first truncated cone.

4. The energy storage device according to claim 3, characterized in that: The injection hole comprises a first hole and a second hole which are interconnected and coaxially arranged, and the aperture of the first hole is smaller than the aperture of the second hole; The first hole is formed inside the first truncated cone, and the second hole is formed inside the truncated cone and the second truncated cone.

5. The energy storage device according to claim 1, characterized in that: The connecting portion has a groove on one side facing the electrode assembly, and the positioning portion is protruding from the bottom surface of the groove; The positioning portion has a communication hole, which is communicated with the liquid injection hole, passes through the outer peripheral side surface of the positioning portion, and is communicated with the groove.

6. The energy storage device according to claim 5, characterized in that: The number of the communicating holes is plural, and the communicating holes are arranged at equal intervals along the circumference of the positioning portion.

7. The energy storage device according to claim 1, characterized in that: One of the cover plate and the disk body is provided with a positioning protrusion, and the other is provided with a positioning groove, and the positioning protrusion is limitedly located in the positioning groove.

8. The energy storage device according to claim 7, characterized in that: The energy storage device also includes an explosion-proof valve connected to the cover plate; The disc body of the current collecting disc has a welding portion connected to the electrode assembly and an exhaust hole penetrating the disc body, and along the thickness direction of the current collecting disc, the exhaust hole corresponds to the position of the explosion-proof valve; There is no overlapping part between the orthographic projections of the welding portion and the explosion-proof valve on a target plane, and the target plane is perpendicular to the thickness direction of the collecting plate.

9. The energy storage device according to claim 8, characterized in that: There are multiple welding parts, and the multiple welding parts are arranged along the circumference of the collecting disk. The length direction of the welding part is parallel to the radial direction of the collecting disk, and the orthographic projection formed by the welding part on the target plane is the first projection, and the orthographic projection formed by the connecting part on the target plane is the second projection, and the first projection and the second projection are arranged at intervals.

10. The energy storage device according to claim 9, characterized in that: There is a shortest distance L1 between the first projection and the second projection, and along the radial direction of the collecting plate, the first projection has a longest distance L2; Among them, L1 and L2 satisfy: L2 / 3≤L1≤L2 / 2.

11. The energy storage device according to claim 8, characterized in that: The orthographic projection of the welding portion on the target plane is a first projection, and the first projection is in a fan shape.

12. The energy storage device according to claim 11, characterized in that: The central angle of the fan shape is between 60° and 300°.

13. An electrical equipment, characterized in that: The energy storage device comprises the energy storage device according to any one of claims 1 to 12, wherein the energy storage device supplies power to the electrical equipment.

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