Battery cell, battery and electric device

Abstract

Provided in the present application are a battery cell, a battery and an electric device. The battery cell comprises a casing, an end cover, an electrode assembly, and a pressure-relief mechanism. The casing has an accommodating space having an opening at one end, and the end cover is connected to the casing and seals off the opening, the end cover being provided with a pressure-relief hole. The electrode assembly is accommodated in the accommodating space. The pressure-relief mechanism is arranged on the end cover and seals off the pressure-relief hole, the pressure-relief mechanism being configured to release the internal pressure of the battery cell. The material of the pressure-relief mechanism comprises steel or nickel, and the material of the end cover comprises steel; the pressure-relief mechanism is welded to the end cover. The material of the pressure-relief mechanism comprising steel or nickel and the material of the end cover comprising steel can improve the structural strength of the end cover and the pressure-relief mechanism, reduce the risk of deformation of the end cover and the pressure-relief mechanism when subjected to a force, and facilitate a reduction in the risk of premature valve opening for pressure relief in the pressure-relief mechanism, helping prolong the service life and enhance the reliability of the battery cell. In addition, the pressure-relief mechanism made of steel or nickel is relatively easy to weld with the end cover made of steel.

Description

Battery cell, battery and electric device Cross-reference to related applications

[0001] This application claims priority to the Chinese patent application (application number: 202422309461.9) filed on September 20, 2024, entitled "Battery cell, battery and electric device", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the field of batteries, in particular to a battery cell, a battery and an electric device. BACKGROUND

[0003] Batteries are widely used in the field of new energy, for example, electric vehicles, new energy vehicles, etc. New energy vehicles and electric vehicles have become a new trend in the development of the automobile industry. The development of battery technology needs to consider various design factors, such as battery life, energy density, discharge capacity, charge-discharge rate, and other performance parameters. In addition, the reliability of the battery also needs to be considered. However, the reliability of the current battery is poor. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a battery cell, a battery and an electric device, which aims to improve the problem of poor reliability of the battery in the related art.

[0005] In a first aspect, the embodiments of the present application provide a battery cell, which comprises a shell, an end cover, an electrode assembly and a pressure relief mechanism, the shell has an open containing space; the end cover is connected to the shell and closes the opening, the end cover is provided with a pressure relief hole; the electrode assembly is contained in the containing space; the pressure relief mechanism is arranged on the end cover and closes the pressure relief hole, the pressure relief mechanism is configured to be able to release the pressure inside the battery cell; wherein the material of the pressure relief mechanism comprises steel or nickel, the material of the end cover comprises steel, and the pressure relief mechanism and the end cover are welded.

[0006] In the technical scheme, the pressure relief mechanism of the battery monomer is arranged on the end cover, and the pressure relief mechanism is connected to the end cover first during manufacturing, and then the end cover is connected to the shell, which is beneficial to simplify the manufacturing and reduce the manufacturing cost. In addition, the space outside the end cover is large, which can facilitate the pressure relief of the pressure relief mechanism. By making the material of the pressure relief mechanism include steel or nickel, and the material of the end cover include steel, on the one hand, the structural strength of the end cover and the pressure relief mechanism can be effectively improved, the risk of deformation of the end cover and the pressure relief mechanism under stress can be reduced, which is beneficial to reduce the risk of early valve pressure relief of the pressure relief mechanism, and is beneficial to improve the service life and reliability of the battery monomer. On the other hand, the pressure relief mechanism made of steel or nickel material is relatively easy to weld with the end cover made of steel material, which is beneficial to reduce the phenomenon of welding cracks between the pressure relief mechanism and the end cover, thereby reducing the risk of liquid leakage of the battery monomer and improving the reliability of the battery monomer.

[0007] As an optional technical scheme of the embodiment of the present application, the pressure relief mechanism and the end cover are both made of steel material.

[0008] In the technical scheme, steel material has high strength and low cost. By making the pressure relief mechanism and the end cover both made of steel material, the structural strength of the end cover and the pressure relief mechanism can be improved, the risk of deformation of the end cover and the pressure relief mechanism under stress can be reduced, which is beneficial to reduce the risk of early valve pressure relief of the pressure relief mechanism, and is beneficial to improve the service life and reliability of the battery monomer. In addition, the pressure relief mechanism and the end cover are made of the same material, which makes the pressure relief mechanism and the end cover easier to weld, which is beneficial to reduce the phenomenon of welding cracks between the pressure relief mechanism and the end cover, thereby reducing the risk of liquid leakage of the battery monomer and improving the reliability of the battery monomer.

[0009] As an optional technical scheme of the embodiment of the present application, the material of the pressure relief mechanism and the end cover is 304 stainless steel.

[0010] In the technical scheme, 304 stainless steel has the advantages of corrosion resistance, high temperature resistance, and good processing performance. The pressure relief mechanism and the end cover made of 304 stainless steel have high strength, which can reduce the risk of deformation of the end cover and the pressure relief mechanism under stress, which is beneficial to reduce the risk of early valve pressure relief of the pressure relief mechanism, and is beneficial to improve the service life and reliability of the battery monomer. In addition, the pressure relief mechanism and the end cover made of 304 stainless steel are also not easy to corrode, which is beneficial to improve the service life of the battery monomer.

[0011] As an optional technical scheme of the embodiment of the present application, the pressure relief mechanism is in the form of a sheet, and the thickness of the pressure relief mechanism is H1, which satisfies 0.05mm≤H1≤0.5mm.

[0012] In the technical solution, when H1 is greater than or equal to 0.05 mm, the thickness of the pressure relief mechanism is relatively large, the pressure relief mechanism has high structural strength, the risk of deformation of the pressure relief mechanism under stress can be reduced, and the service life and reliability of the battery cell can be improved. When H1 is less than or equal to 0.5 mm, the thickness of the pressure relief mechanism is not too large, and the manufacturing cost of the battery cell can be controlled. Therefore, when 0.05 mm≤H1≤0.5 mm, the service life, reliability and manufacturing cost of the battery cell can be considered.

[0013] As an optional technical solution of the embodiment, 0.05 mm≤H1≤0.3 mm.

[0014] In the technical solution, when H1 is greater than or equal to 0.05 mm, the thickness of the pressure relief mechanism is relatively large, the pressure relief mechanism has high structural strength, the risk of deformation of the pressure relief mechanism under stress can be reduced, and the service life and reliability of the battery cell can be improved. When H1 is less than or equal to 0.3 mm, the thickness of the pressure relief mechanism is not too large, and the manufacturing cost of the battery cell can be controlled. Therefore, when 0.05 mm≤H1≤0.3 mm, the service life, reliability and manufacturing cost of the battery cell can be considered.

[0015] As an optional technical solution of the embodiment, the pressure relief mechanism is provided with a pressure relief groove, and the pressure relief mechanism is configured to split along at least part of the pressure relief groove when the battery cell is relieved of pressure.

[0016] In the technical solution, a weak part is formed on the pressure relief mechanism by opening a pressure relief groove on the pressure relief mechanism. When the battery cell is relieved of pressure, the pressure relief mechanism splits along at least part of the weak part, which is simple, convenient and low in cost.

[0017] As an optional technical solution of the embodiment, the residual thickness of the pressure relief groove is D, and 0.01 mm≤D≤0.3 mm.

[0018] In the technical solution, when D is greater than or equal to 0.01 mm, the residual thickness of the pressure relief groove is relatively large, which is beneficial to reduce the risk of early valve opening of the pressure relief mechanism, improve the service life and reliability of the battery cell. When D is less than or equal to 0.3 mm, the residual thickness of the pressure relief groove is not too large, so that the pressure relief mechanism can be opened in time when the battery cell is out of control, which is beneficial to improve the timeliness of the pressure relief mechanism. Therefore, when 0.01 mm≤D≤0.3 mm, the service life, reliability and pressure relief timeliness of the battery cell can be considered.

[0019] As an optional technical solution of the embodiment, 0.015 mm≤D≤0.15 mm.

[0020] In the technical solution, when D is greater than or equal to 0.015 mm, the residual thickness of the pressure relief groove is greater, which is beneficial to reduce the risk of the pressure relief mechanism opening the valve to release pressure in advance, and improve the service life and reliability of the battery monomer. When D is less than or equal to 0.15 mm, the residual thickness of the pressure relief groove is not too large, so that the pressure relief mechanism can open the valve to release pressure in time when the battery monomer is out of control, which is beneficial to improve the timeliness of the pressure relief mechanism. Therefore, when 0.015 mm≤D≤0.15 mm, the service life, reliability and timeliness of the battery monomer can be considered.

[0021] As an optional technical solution of the embodiment of the application, the thickness of the end cover is H2, and 0.2 mm≤H2≤3 mm is met.

[0022] In the technical solution, when H2 is greater than or equal to 0.2 mm, the thickness of the end cover is large, the end cover has high structural strength, and the risk of deformation of the end cover under stress can be reduced, which is beneficial to reduce the risk of the pressure relief mechanism opening the valve to release pressure in advance, and improve the service life and reliability of the battery monomer. When H2 is less than or equal to 3 mm, the thickness of the end cover is not too large, which is beneficial to control the manufacturing cost of the battery monomer. Therefore, when 0.2 mm≤H2≤3 mm, the service life, reliability and manufacturing cost of the battery monomer can be considered.

[0023] As an optional technical solution of the embodiment of the application, 0.3 mm≤H2≤2.5 mm is met.

[0024] In the technical solution, when H2 is greater than or equal to 0.3 mm, the thickness of the end cover is larger, the end cover has higher structural strength, and the risk of deformation of the end cover under stress can be reduced, which is beneficial to reduce the risk of the pressure relief mechanism opening the valve to release pressure in advance, and improve the service life and reliability of the battery monomer. When H2 is less than or equal to 2.5 mm, the thickness of the end cover is not too large, which is beneficial to control the manufacturing cost of the battery monomer. Therefore, when 0.3 mm≤H2≤2.5 mm, the service life, reliability and manufacturing cost of the battery monomer can be considered.

[0025] As an optional technical solution of the embodiment of the application, the pressure relief mechanism is located at one end of the pressure relief hole facing the shell.

[0026] In the technical solution, when the pressure relief mechanism is arranged at one end of the pressure relief hole facing the shell, the risk of the pressure relief mechanism being affected by external force is smaller, which is beneficial to reduce the risk of the pressure relief mechanism opening the valve to release pressure in advance, and improve the service life and reliability of the battery monomer.

[0027] As an optional technical solution of the embodiment of the present application, the end cover has a first surface facing the shell, the first surface is provided with a groove, the groove is in communication with the pressure relief hole; the pressure relief mechanism is partially accommodated in the groove, and the part of the pressure relief mechanism accommodated in the groove is welded with the end cover.

[0028] In the above technical solution, by arranging the groove on the end cover and partially accommodating the pressure relief mechanism in the groove, on the one hand, the groove can position the pressure relief mechanism, thereby facilitating the welding of the pressure relief mechanism to the end cover. On the other hand, the groove bottom wall can support the pressure relief mechanism, so that the pressure relief mechanism is not easy to be welded through when the pressure relief mechanism and the end cover are welded.

[0029] As an optional technical solution of the embodiment of the present application, the part of the pressure relief mechanism accommodated in the groove has a second surface facing the shell, and the distance between the first surface and the second surface along the thickness direction of the end cover is L, which satisfies: L≤0.15mm.

[0030] In the above technical solution, by making the height difference between the first surface and the second surface along the thickness direction of the end cover less than or equal to 0.15mm, the welding quality of the pressure relief mechanism and the end cover is improved.

[0031] As an optional technical solution of the embodiment of the present application, the first surface and the second surface are flush.

[0032] In the above technical solution, when the first surface and the second surface are flush, the pressure relief mechanism and the end cover can be welded by using the method of butt welding, the heat of butt welding is small, which is conducive to reducing the risk of cracking of the pressure relief mechanism.

[0033] As an optional technical solution of the embodiment of the present application, the end cover comprises a body part and a support part, the pressure relief hole is arranged on the support part, and the support part and the body part jointly define a groove in communication with the pressure relief hole; the pressure relief mechanism is partially accommodated in the groove and abuts against the support part, and the pressure relief mechanism is welded with the body part.

[0034] In the above technical solution, the support part and the body part jointly define the groove, and the pressure relief mechanism is accommodated in the groove. On the one hand, the groove can position the pressure relief mechanism, thereby facilitating the welding of the pressure relief mechanism to the body part. On the other hand, the support part can support the pressure relief mechanism, so that the pressure relief mechanism and the body part are not easy to be welded through when they are welded.

[0035] As an optional technical solution of the embodiment of the present application, the support part and the body part are integrally formed.

[0036] In the technical solution, the support part and the body part are integrally formed, so that the end cover has better structural strength, and the reliability of the battery cell is improved.

[0037] As an optional technical solution of the embodiment, the thickness of the support part in the thickness direction of the end cover is H3, and 0.2mm≤H3≤3mm is satisfied.

[0038] In the technical solution, when H3≥0.2mm, the thickness of the support part is large, and the risk of welding through when the pressure relief mechanism and the body part are welded is reduced. When H3≤3mm, the thickness of the support part is not too large, on the one hand, the occupation of the battery cell or the internal space of the battery is reduced, and the energy density of the battery is improved. On the other hand, the material consumption is reduced, and the cost of the battery cell is reduced. Therefore, when 0.2mm≤H3≤3mm, the risk of welding through during welding is reduced, and the energy density of the battery is improved.

[0039] As an optional technical solution of the embodiment, 0.3mm≤H3≤2.5mm.

[0040] In the technical solution, when H3≥0.3mm, the thickness of the support part is larger, and the risk of welding through when the pressure relief mechanism and the body part are welded is reduced. When H3≤2.5mm, the thickness of the support part is not too large, on the one hand, the occupation of the battery cell or the internal space of the battery is reduced, and the energy density of the battery is improved. On the other hand, the material consumption is reduced, and the cost of the battery cell is reduced. Therefore, when 0.3mm≤H3≤2.5mm, the risk of welding through during welding is reduced, and the energy density of the battery is improved.

[0041] As an optional technical solution of the embodiment, the shell and the end cover are both made of steel.

[0042] In the technical solution, the steel has high strength and low cost. By making the shell and the end cover both made of steel, the structural strength of the shell and the end cover is improved, and the risk of deformation of the shell and the end cover under stress is reduced, which is beneficial to improve the reliability of the battery cell. In addition, the shell and the end cover are made of the same material, so that the shell and the end cover are easy to weld, which is beneficial to reduce the phenomenon of welding cracks of the shell and the end cover, thereby reducing the risk of liquid leakage of the battery cell and improving the reliability of the battery cell.

[0043] In a second aspect, the embodiment also provides a battery, which comprises the battery cell.

[0044] In a third aspect, the embodiment also provides a use electric device, which comprises the battery cell, and the battery cell is used to provide electric energy for the use electric device. Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 is a schematic diagram of the vehicle structure provided in some embodiments of this application;

[0047] Figure 2 is an exploded view of a battery provided in some embodiments of this application;

[0048] Figure 3 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0049] Figure 4 is an exploded view of a single battery cell provided in some embodiments of this application;

[0050] Figure 5 is a top view of an end cap provided in some embodiments of this application;

[0051] Figure 6 is a cross-sectional view of position AA in Figure 5 (showing the pressure relief mechanism);

[0052] Figure 7 is a cross-sectional view of position AA in Figure 5 (with the pressure relief mechanism hidden);

[0053] Figure 8 is a cross-sectional view of an end cap provided in some other embodiments of this application.

[0054] Icons: 10-Box; 11-First part; 12-Second part; 20-Battery cell; 21-Housing shell; 22-End cap; 221-Body part; 222-Support part; 223-Pressure relief hole; 224-Groove; 225-First surface; 23-Electrode assembly; 231-Body body; 232-Electrode tab; 24-Pressure relief mechanism; 241-Pressure relief groove; 242-Soldering part; 243-Second surface; 25-Electrode terminal; 26-Protective component; 27-Insulating component; 100-Battery; 200-Controller; 300-Motor; 1000-Vehicle. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, all terms used in disclosing the application, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The articles 'a', 'an', and 'the' each followed by'some or more' or 'one or more' of an element are intended to include one or more articles of the described element and do not exclude other additional elements. As used in this application, the terms "comprises", "comprising", "includes", "including", or the like are used in the sense of "including but not limited to", and not in the sense of "consisting only of the listed items". The terms "coupled" and "connected", along with derivatives thereof, are used to indicate that two or more elements, if any, are in either physical or logical contact depending upon the specific context. Any reference to "about 20" includes 20.

[0057] Reference throughout this application to "example" means that a particular feature, structure, or characteristic described in connection with the example is included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of other embodiments.

[0058] In the description of the application, it is necessary to explain that, unless otherwise explicitly defined and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0059] In this application, the term "and / or", only describes the relationship between the associated objects, which means that there are three kinds of relationships, for example, A and / or B, which means that there are three kinds of situations: A alone, A and B exist at the same time, and B alone. In addition, the character " / " in this application generally represents that the front and rear associated objects have an "or" relationship.

[0060] In the embodiments of the application, the same reference signs represent the same parts, and for the sake of brevity, the detailed description of the same parts is omitted in different embodiments. It should be understood that the thickness, length and width of various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length and width of the integrated device, are only exemplary and should not constitute any limitation on the application.

[0061] "Multiple" appearing in this application refers to two or more (including two).

[0062] In the embodiments of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging to continue to use.

[0063] The battery cell can 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 hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc. The embodiments of the present application are not limited thereto.

[0064] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging of the battery cell, active ions (e.g., lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, and can prevent the positive and negative electrodes from shorting to some extent, while allowing the active ions to pass through.

[0065] In some embodiments, the positive electrode can be a positive electrode tab, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0066] As an example, the positive electrode current collector has two opposite surfaces in the thickness direction thereof, and the positive electrode active material is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0067] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, aluminum with silver plating on the surface, stainless steel with silver plating on the surface, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0068] As an example, the positive electrode active material can include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials can also be used. These positive electrode active materials can be used alone or in combination with two or more. Among them, examples of lithium-containing phosphates can include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP for short)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of lithium transition metal oxides can include, but are not limited to, at least one of lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn1 / 3 O2(also can be referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2(also can be referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2(also can be referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2(also can be referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2(also can be referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2), and modified compounds thereof.

[0069] In some embodiments, the positive electrode can employ a foam metal. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, or the like. When the foam metal is used as the positive electrode, the surface of the foam metal can not be provided with the positive electrode active material, or of course can be provided with the positive electrode active material. As an example, the foam metal can be filled or / and deposited with a lithium source material, a potassium metal, or a sodium metal, the lithium source material being a lithium metal and / or a lithium-rich material.

[0070] In some embodiments, the negative electrode can be a negative electrode tab, which can include a negative electrode current collector.

[0071] As an example, the negative electrode current collector can employ a metal foil, a foam metal, or a composite current collector. For example, as the metal foil, silver surface treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, nickel, or titanium, or the like can be employed. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, or the like. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, or the like) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0072] As an example, the negative electrode tab can include the negative electrode current collector and the negative electrode active material provided on at least one surface of the negative electrode current collector.

[0073] As an example, the negative current collector has two surfaces opposite in the thickness direction thereof, and the negative active material is disposed on either one or both of the two surfaces of the negative current collector.

[0074] As an example, the negative active material can employ a negative active material for a battery cell known in the art. As an example, the negative active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery negative active material can also be used. These negative active materials can be used alone or in combination of two or more.

[0075] In some embodiments, the material of the positive current collector can be aluminum, and the material of the negative current collector can be copper.

[0076] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0077] In some embodiments, the separator is a separator film. The separator film can be of various types, and any known porous structure separator film having good chemical stability and mechanical stability can be used.

[0078] As an example, the material of the separator film can include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator film can be a single layer film or a multi-layer composite film. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different. The separator can be a separate component located between the positive and negative electrodes, or can be attached to the surface of the positive and negative electrodes.

[0079] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and functions to transport ions and separate the positive and negative electrodes.

[0080] In some embodiments, the battery cell further includes an electrolyte that functions to conduct ions between the positive and negative electrodes. The electrolyte can be in a liquid state, a gel state, or a solid state. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0081] In some embodiments, the electrolyte salt can include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonylimide, lithium bis-trifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoroboric oxalate, lithium boric oxalate, lithium difluorophosphoric oxalate, and lithium tetrafluorophosphoric oxalate.

[0082] In some embodiments, the solvent can include at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, butyl sulfone, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be selected from ether solvents. The ether solvents can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ether.

[0083] In some embodiments, the gel-state electrolyte includes a polymer as a skeleton network of the electrolyte, in combination with an ionic liquid-lithium salt.

[0084] In some embodiments, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, a composite solid-state electrolyte.

[0085] As an example, the polymer solid-state electrolyte can be a polyether (polyethylene oxide), a polysiloxane, a polycarbonate, a polyacrylonitrile, a polyvinylidene fluoride, a polymethyl methacrylate, a single-ion polymer, a polyionic liquid-lithium salt, a cellulose, or the like.

[0086] As an example, the inorganic solid-state electrolyte can include one or more of an oxide solid-state electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid-state electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorous sulfide, argyrodite), amorphous sulfide), and a halide solid-state electrolyte, a nitride solid-state electrolyte, and a hydride solid-state electrolyte.

[0087] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0088] In some embodiments, the electrode assembly is in a jelly-roll structure. The positive electrode sheet and the negative electrode sheet are wound into the jelly-roll structure.

[0089] In some embodiments, the electrode assembly is in a stack structure.

[0090] As an example, the positive electrode sheet and the negative electrode sheet can be provided in a plurality of each, and the plurality of positive electrode sheets and the plurality of negative electrode sheets are alternately stacked.

[0091] As an example, the positive electrode sheet can be provided in a plurality, and the negative electrode sheet is folded to form a plurality of stacked folded segments, and one positive electrode sheet is clamped between adjacent folded segments.

[0092] As an example, the positive electrode tab and the negative electrode tab are each folded to form a plurality of folded segments that are stacked.

[0093] As an example, the separator can be provided in plurality and arranged between any adjacent positive electrode tab or negative electrode tab.

[0094] As an example, the separator can be provided in plurality and arranged between any adjacent positive electrode tab or negative electrode tab.

[0095] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a multi-prism shape, etc.

[0096] In some embodiments, the electrode assembly can be provided with a tab, which can lead current out of the electrode assembly. The tab can include a positive tab and a negative tab.

[0097] In some embodiments, the battery cell can include a housing. The housing can be used to encapsulate components such as the electrode assembly and the electrolyte. The housing can 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.

[0098] In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a sealed structure, the housing can protect the electrode assembly and prevent electrolyte leakage to some extent. When the housing is a non-sealed structure, the housing can protect the electrode assembly, and a sealing bag can be further included between the housing and the electrode assembly. The sealing bag can be used to encapsulate components such as the electrode assembly and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum-plastic film.

[0099] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. The prismatic battery cell can include, but is not limited to, a square battery cell, a blade battery cell, a multi-prismatic battery cell, such as a hexagonal battery cell, etc.

[0100] The battery referred to in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0101] In some embodiments, the battery can be a battery module. When there are multiple battery cells, the battery cells can be arranged and fixed to form a battery module.

[0102] In some embodiments, the battery can be a battery pack. The battery pack can include a box and battery cells or battery modules, which are accommodated in the box.

[0103] In some embodiments, the box can be part of a chassis structure of a vehicle. For example, portions of the box can become at least part of a floor of the vehicle, or portions of the box can become at least part of cross members and longitudinal members of the vehicle.

[0104] In some embodiments, the battery can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0105] At present, from the development of market situation, the application of battery is more and more widely. The battery is not only applied to the energy storage power supply system of hydropower, thermal power, wind power and solar power station, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of battery, the demand of its market is also increasing.

[0106] The development of battery technology needs to consider many design factors, such as battery life, energy density, discharge capacity, charge-discharge rate and other performance parameters. In addition, the reliability of the battery also needs to be considered. However, the reliability of the current battery is poor.

[0107] For a general battery monomer, in order to improve the reliability of the battery monomer, a pressure relief structure is usually arranged on the shell of the battery monomer to release the internal pressure of the battery monomer through the pressure relief structure, so as to effectively improve the reliability of the battery monomer. In the related art, the shell of the battery monomer is usually made of aluminum, and the structural strength of the shell of the battery monomer is weak. The shell is easily deformed under external force, which pulls the pressure relief structure and makes the pressure relief structure open in advance, resulting in poor reliability of the battery monomer.

[0108] In view of this, the embodiments of the present application provide a battery monomer, which comprises a shell, an end cover, an electrode assembly and a pressure relief mechanism. The shell has an open-ended accommodation space, and the end cover is connected to the shell and closes the opening. The end cover is provided with a pressure relief hole. The electrode assembly is accommodated in the accommodation space. The pressure relief mechanism is arranged on the end cover and closes the pressure relief hole, and the pressure relief mechanism is configured to release the pressure inside the battery monomer. The material of the pressure relief mechanism includes steel or nickel, the material of the end cover includes steel, and the pressure relief mechanism and the end cover are welded.

[0109] The pressure relief mechanism of the battery cell is arranged on the end cover. During manufacturing, the pressure relief mechanism can be connected to the end cover first, and then the end cover is connected to the shell, which is beneficial to simplify the manufacturing and reduce the manufacturing cost. In addition, the space outside the end cover is large, which can facilitate the pressure relief of the pressure relief mechanism. By making the material of the pressure relief mechanism include steel or nickel, and the material of the end cover include steel, on the one hand, the structural strength of the end cover and the pressure relief mechanism can be effectively improved, the risk of deformation of the end cover and the pressure relief mechanism under stress can be reduced, which is beneficial to reduce the risk of early valve pressure relief of the pressure relief mechanism, and improve the service life and reliability of the battery cell. On the other hand, the pressure relief mechanism made of steel or nickel material is relatively easy to weld with the end cover made of steel material, which is beneficial to reduce the phenomenon of welding cracks between the pressure relief mechanism and the end cover, thereby reducing the risk of liquid leakage of the battery cell and improving the reliability of the battery cell.

[0110] The technical solutions described in the embodiments of the present application are suitable for batteries and electric devices using batteries.

[0111] The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, and an electric tool, etc. The spacecraft includes an airplane, a rocket, a space shuttle, a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, and an electric plane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, which can include but is not limited to an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, etc.

[0112] The following embodiments take the vehicle 1000 as an example for convenience of description.

[0113] Please refer to FIG. 1, which is a structural schematic diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 can be a fuel automobile, a gas automobile, or a new energy automobile, which can be a pure electric vehicle, a hybrid electric vehicle, or a range extended vehicle, etc. The vehicle 1000 is internally provided with a battery 100, which can be arranged at the bottom, the head, or the tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000, for example, the battery 100 can be used as an operating power source of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300, the controller 200 is used to control the battery 100 to supply power to the motor 300, for example, for the working power demand of the vehicle 1000 during starting, navigation, and driving.

[0114] In some embodiments of the present application, the battery 100 can not only be used as an operating power source of the vehicle 1000, but also be used as a driving power source of the vehicle 1000, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 1000.

[0115] Please refer to FIG. 2, which is an exploded view of the battery 100 according to some embodiments of the present application. The battery 100 includes a box 10 and a battery cell 20, which is accommodated in the box 10. The box 10 is used to provide a space for accommodating the battery cell 20, and the box 10 can have various structures. In some embodiments, the box 10 can include a first part 11 and a second part 12, the first part 11 and the second part 12 are overlapped with each other, and the first part 11 and the second part 12 together define a space for accommodating the battery cell 20. The second part 12 can be a hollow structure with one end open, and the first part 11 can be a plate structure, which is overlapped with the open end of the second part 12 to define the space together with the second part 12. The first part 11 and the second part 12 can also be hollow structures with one side open, and the open end of the first part 11 is overlapped with the open end of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0116] In the battery 100, the battery cell 20 can be multiple, and the multiple battery cells 20 can be connected in series, in parallel, or in a mixed connection. The mixed connection means that some of the multiple battery cells 20 are connected in series and some are connected in parallel. The multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed connection, and then the whole of the multiple battery cells 20 is accommodated in the box 10. Of course, the battery 100 can also be that the multiple battery cells 20 are first connected in series, in parallel, or in a mixed connection to form a battery module, and then multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, which is accommodated in the box 10. The battery 100 can also include other structures, for example, the battery 100 can also include a busbar component for realizing the electrical connection between the multiple battery cells 20.

[0117] Each battery cell 20 can be a secondary battery cell or a primary battery cell, and can also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited thereto. The battery cell 20 can have a cylindrical shape, a flat shape, a cuboid shape, or other shapes, etc.

[0118] Please refer to FIG. 3, FIG. 4, FIG. 5, FIG. 6 and FIG. 7. FIG. 3 is a structural schematic diagram of a battery cell 20 according to some embodiments of the present application. FIG. 4 is an exploded view of the battery cell 20 according to some embodiments of the present application. FIG. 5 is a top view of an end cover 22 according to some embodiments of the present application. FIG. 6 is a sectional view of the position A-A in FIG. 5 (showing a pressure relief mechanism 24). FIG. 7 is a sectional view of the position A-A in FIG. 5 (hiding the pressure relief mechanism 24). Some embodiments of the present application provide a battery cell 20, which includes a housing 21, an end cover 22, an electrode assembly 23 and a pressure relief mechanism 24. The housing 21 has an accommodating space with an open end, and the end cover 22 is connected to the housing 21 and closes the open end. The end cover 22 is provided with a pressure relief hole 223. The electrode assembly 23 is accommodated in the accommodating space. The pressure relief mechanism 24 is arranged on the end cover 22 and closes the pressure relief hole 223, and the pressure relief mechanism 24 is configured to be able to release the pressure inside the battery cell 20. The material of the pressure relief mechanism 24 includes steel or nickel, the material of the end cover 22 includes steel, and the pressure relief mechanism 24 is welded to the end cover 22.

[0119] The battery cell 20 refers to the smallest unit that constitutes the battery 100.

[0120] The housing 21 has an accommodating space with an open end, and the accommodating space is used to accommodate the electrode assembly 23. The end cover 22 is connected to the housing 21 and closes the open end.

[0121] The end cover 22 refers to a component that covers the open end of the housing 21 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cover 22 can be adapted to the shape of the housing 21 to fit the housing 21. Optionally, the end cover 22 can be made of a material with certain hardness and strength, such as aluminum alloy, so that the end cover 22 is not easy to deform when subjected to extrusion and collision, so that the battery cell 20 can have higher structural strength and the reliability can also be improved. The material of the end cover 22 can include but is not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. The end cover 22 is also provided with an electrode terminal 25, which is used to electrically connect with the tab 232 of the electrode assembly 23 to input or output the electrical energy of the battery cell 20. The electrode terminal 25 and the tab 232 can be directly connected, for example, the electrode terminal 25 and the tab 232 are directly welded. The electrode terminal 25 and the tab 232 can also be indirectly connected, for example, the electrode terminal 25 and the tab 232 are indirectly connected through a current collecting member. The battery cell 20 also includes an insulating member 27, which is arranged on the inner side of the end cover 22. The insulating member 27 can be used to isolate the electrical connection components in the housing 21 from the end cover 22 to reduce the risk of short circuit. Exemplarily, the insulating member 27 can be plastic, rubber, etc.

[0122] The case 21 is a component for fitting the end cap 22 to form an internal environment of the battery cell 20, and the formed internal environment can be used to accommodate the electrode assembly 23, the electrolyte, and other components. The case 21 and the end cap 22 can be separate components, and an opening can be provided on the case 21, and the end cap 22 can be fitted to the opening to form the internal environment of the battery cell 20. Without limitation, the end cap 22 and the case 21 can also be integrated, and specifically, the end cap 22 and the case 21 can be formed as a common joint surface before other components are put into the case, and the end cap 22 can be fitted to the case 21 when it is necessary to seal the internal environment of the case 21. The case 21 can be various shapes and sizes, such as a cuboid, a cylinder, a hexagonal prism, and the like. Specifically, the shape of the case 21 can be determined according to the specific shape and size of the electrode assembly 23. The material of the case 21 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, and the like.

[0123] The electrode assembly 23 is a component in which electrochemical reactions occur in the battery cell 20. One or more electrode assemblies 23 can be contained in the case 21. The electrode assembly 23 is mainly formed by winding or stacking a positive electrode tab and a negative electrode tab, and an insulating film is usually provided between the positive electrode tab and the negative electrode tab. The positive electrode tab and the negative electrode tab have a portion with active material constituting a main body 231 of the electrode assembly 23, and a portion without active material constituting a tab 232 of each of the positive electrode tab and the negative electrode tab. The positive tab and the negative tab can be located together at one end of the main body 231 or at both ends of the main body 231, respectively. During charging and discharging of the battery 100, the positive active material and the negative active material react with the electrolyte.

[0124] The end cap 22 is provided with a pressure relief hole 223 that penetrates the end cap 22 in the thickness direction of the end cap 22. In other words, the pressure relief hole 223 is a through hole provided in the end cap 22. Referring to FIGS. 4 and 6, the thickness direction of the end cap 22 can be the X direction shown in the figures.

[0125] The pressure relief mechanism 24 is a component for opening when the internal pressure or temperature of the battery cell 20 reaches an initiation pressure to release the internal pressure of the battery cell 20. The pressure relief mechanism 24 is a component mounted on the end cap 22, and the pressure relief mechanism 24 is provided separately from and connected to the end cap 22 (in manufacturing, the pressure relief hole 223 is provided on the end cap 22, the pressure relief mechanism 24 and the end cap 22 are provided separately, and finally connected together). For example, the pressure relief mechanism 24 is a rupture disc mounted on the end cap 22.

[0126] The material of the pressure relief mechanism 24 includes steel or nickel, and the material of the pressure relief mechanism 24 can be carbon steel or stainless steel. The carbon steel can be low carbon steel, medium carbon steel, or high carbon steel. For example, the material of the pressure relief mechanism 24 can be 304 stainless steel, 305 stainless steel, 316 stainless steel, nickel, or the like.

[0127] The material of the end cover 22 can be carbon steel or stainless steel. The carbon steel can be low carbon steel, medium carbon steel, or high carbon steel. For example, the material of the end cover 22 can be 304 stainless steel.

[0128] The pressure relief mechanism 24 of the battery cell 20 is arranged on the end cover 22. In manufacturing, the pressure relief mechanism 24 can be connected to the end cover 22 first, and then the end cover 22 is connected to the shell 21, which is beneficial to simplify manufacturing and reduce manufacturing cost. In addition, the space outside the end cover 22 is large, which can facilitate pressure relief of the pressure relief mechanism 24. By making the material of the pressure relief mechanism 24 include steel or nickel, and the material of the end cover 22 include steel, on the one hand, the structural strength of the end cover 22 and the pressure relief mechanism 24 can be effectively improved, and the risk of deformation of the end cover 22 and the pressure relief mechanism 24 under stress can be reduced, which is beneficial to reduce the risk of early valve pressure relief of the pressure relief mechanism 24, and is beneficial to improve the service life and reliability of the battery cell 20. On the other hand, the steel material or the nickel material of the pressure relief mechanism 24 is relatively easy to weld with the steel material of the end cover 22, which is beneficial to reduce the phenomenon of welding cracks between the pressure relief mechanism 24 and the end cover 22, thereby reducing the risk of liquid leakage of the battery cell 20 and improving the reliability of the battery cell 20.

[0129] In some embodiments, the pressure relief mechanism 24 and the end cover 22 are both steel materials.

[0130] The steel material is carbon steel or stainless steel.

[0131] For example, the carbon steel can be low carbon steel, medium carbon steel, or high carbon steel.

[0132] The pressure relief mechanism 24 and the end cover 22 can both be stainless steel, or the pressure relief mechanism 24 and the end cover 22 can both be carbon steel. In some embodiments, one of the pressure relief mechanism 24 and the end cover 22 is carbon steel, and the other of the pressure relief mechanism 24 and the end cover 22 is stainless steel.

[0133] When the pressure relief mechanism 24 and the end cover 22 are both carbon steel, the pressure relief mechanism 24 and the end cover 22 can both be low carbon steel, or the pressure relief mechanism 24 and the end cover 22 can both be medium carbon steel, or the pressure relief mechanism 24 and the end cover 22 can both be high carbon steel. In some embodiments, one of the pressure relief mechanism 24 and the end cover 22 is medium carbon steel, and the other of the pressure relief mechanism 24 and the end cover 22 is low carbon steel or high carbon steel.

[0134] Steel has high strength and low cost. By making the pressure relief mechanism 24 and the end cover 22 both of steel, the structural strength of the end cover 22 and the pressure relief mechanism 24 can be improved, the risk of deformation of the end cover 22 and the pressure relief mechanism 24 under stress can be reduced, the risk of the pressure relief mechanism 24 opening the valve to relieve pressure in advance can be reduced, and the service life and reliability of the battery monomer 20 can be improved. In addition, the pressure relief mechanism 24 and the end cover 22 are made of the same material, so that the pressure relief mechanism 24 and the end cover 22 are easier to weld, the phenomenon of welding cracks between the pressure relief mechanism 24 and the end cover 22 can be reduced, the risk of liquid leakage of the battery monomer 20 can be reduced, and the reliability of the battery monomer 20 can be improved.

[0135] Optionally, the materials of the pressure relief mechanism 24 and the end cover 22 are both 304 stainless steel.

[0136] 304 stainless steel is also called 18 / 8 stainless steel, which means that it contains more than 18% chromium and more than 8% nickel.

[0137] 304 stainless steel has the advantages of corrosion resistance, high temperature resistance, and good processing performance. The pressure relief mechanism 24 and the end cover 22 made of 304 stainless steel have high strength, can reduce the risk of deformation of the end cover 22 and the pressure relief mechanism 24 under stress, can reduce the risk of the pressure relief mechanism 24 opening the valve to relieve pressure in advance, and can improve the service life and reliability of the battery monomer 20. In addition, the pressure relief mechanism 24 and the end cover 22 made of 304 stainless steel are also not easy to corrode, which can improve the service life of the battery monomer 20.

[0138] Please refer to FIG. 3, FIG. 4, FIG. 5, FIG. 6 and FIG. 7. In some embodiments, the pressure relief mechanism 24 is in a sheet shape, and the thickness of the pressure relief mechanism 24 is H1, which satisfies: 0.05mm≤H1≤0.5mm.

[0139] The pressure relief mechanism 24 is in a sheet shape. For example, the pressure relief mechanism 24 is a rupture disc.

[0140] H1 represents the thickness of the pressure relief mechanism 24. It should be noted that the thickness of the pressure relief mechanism 24 refers to the thickness of the pressure relief mechanism 24 at a non-weak position. For example, in some embodiments, the pressure relief mechanism 24 is provided with a pressure relief groove 241, and the pressure relief mechanism 24 is configured to break along at least a part of the pressure relief groove 241 when the battery monomer 20 is relieved. At this time, the thickness of the pressure relief mechanism 24 is the thickness of the area of the pressure relief mechanism 24 except the pressure relief groove 241. When measuring, the average value of multiple measurements can be taken as H1.

[0141] The thickness of the pressure relief mechanism 24 can be: H1=0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, etc.

[0142] When H1≥0.05 mm, the thickness of the pressure relief mechanism 24 is relatively large, the pressure relief mechanism 24 has relatively high structural strength, and the risk of deformation of the pressure relief mechanism 24 under stress can be reduced, which is conducive to improving the service life and reliability of the battery monomer 20. When H1≤0.5 mm, the thickness of the pressure relief mechanism 24 is not too large, which is conducive to controlling the manufacturing cost of the battery monomer 20. Therefore, when 0.05 mm≤H1≤0.5 mm, the service life, reliability and manufacturing cost of the battery monomer 20 can be considered.

[0143] Optionally, 0.05 mm≤H1≤0.3 mm.

[0144] The thickness of the pressure relief mechanism 24 can be: H1=0.05 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm, 0.3 mm, etc.

[0145] When H1≥0.05 mm, the thickness of the pressure relief mechanism 24 is relatively large, the pressure relief mechanism 24 has relatively high structural strength, and the risk of deformation of the pressure relief mechanism 24 under stress can be reduced, which is conducive to improving the service life and reliability of the battery monomer 20. When H1≤0.3 mm, the thickness of the pressure relief mechanism 24 is not too large, which is more conducive to controlling the manufacturing cost of the battery monomer 20. Therefore, when 0.05 mm≤H1≤0.3 mm, the service life, reliability and manufacturing cost of the battery monomer 20 can be considered.

[0146] Please refer to FIG. 3, FIG. 4, FIG. 5, FIG. 6 and FIG. 7, in some embodiments, the pressure relief mechanism 24 is provided with a pressure relief groove 241, and the pressure relief mechanism 24 is configured to split along at least part of the pressure relief groove 241 when the battery monomer 20 is relieved.

[0147] The pressure relief mechanism 24 has an inner surface and an outer surface arranged opposite in the thickness direction of the end cover 22. The inner surface of the pressure relief mechanism 24 can be provided with the pressure relief groove 241, or the outer surface of the pressure relief mechanism 24 can be provided with the pressure relief groove 241. Taking the outer surface of the pressure relief mechanism 24 provided with the pressure relief groove 241 as an example, that is, the pressure relief groove 241 is recessed from the outer surface to the inner surface.

[0148] The pressure relief groove 241 can be formed in various ways, such as stamping forming, cold heading forming, etc. Taking the way of stamping forming as an example, the pressure relief groove 241 can be formed on the pressure relief mechanism 24 along the thickness direction of the end cover 22.

[0149] The pressure relief groove 241 is formed by stamping or cold heading, which causes cold work hardening of the groove wall of the pressure relief groove 241 (change in grain arrangement, lattice distortion, reduction in metal plasticity, and increase in material hardness), thereby enhancing the ability of the pressure relief groove 241 to resist external impact and reducing the risk of damage due to external impact. This is conducive to reducing the risk of liquid leakage of the pressure relief mechanism 24.

[0150] The pressure relief groove 241 is formed by opening the pressure relief groove 241 on the pressure relief mechanism 24 to form a weak part on the pressure relief mechanism 24. When the battery cell 20 is relieved, the pressure relief mechanism 24 is broken along at least part of the weak part, which is simple, convenient, and low in cost.

[0151] Referring to FIGS. 3, 4, 5, 6, and 7, in some embodiments, the residual thickness D of the pressure relief groove 241 satisfies 0.01 mm≤D≤0.3 mm.

[0152] D represents the residual thickness of the pressure relief groove 241, i.e., the remaining thickness of the pressure relief mechanism 24 at the position where the pressure relief groove 241 is arranged. When the pressure relief groove 241 is arranged on the outer surface of the pressure relief mechanism 24, the residual thickness of the pressure relief groove 241 is the distance from the groove bottom surface of the pressure relief groove 241 to the inner surface of the pressure relief mechanism 24. When the pressure relief groove 241 is arranged on the inner surface of the pressure relief mechanism 24, the residual thickness of the pressure relief groove 241 is the distance from the groove bottom surface of the pressure relief groove 241 to the outer surface of the pressure relief mechanism 24.

[0153] The residual thickness of the pressure relief groove 241 can be 0.01 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, etc.

[0154] When D≥0.01 mm, the residual thickness of the pressure relief groove 241 is large, which is conducive to reducing the risk of premature opening of the pressure relief mechanism 24 and improving the service life and reliability of the battery cell 20. When D≤0.3 mm, the residual thickness of the pressure relief groove 241 is not too large, so that the pressure relief mechanism 24 can be opened in time when the battery cell 20 is out of control, which is conducive to improving the timeliness of the pressure relief mechanism 24. Therefore, when 0.01 mm≤D≤0.3 mm, the service life, reliability, and timeliness of the pressure relief mechanism 24 can be considered.

[0155] Optionally, 0.015 mm≤D≤0.15 mm.

[0156] The residual thickness of the pressure relief groove 241 can be: D = 0.015 mm, 0.02 mm, 0.025 mm, 0.03 mm, 0.035 mm, 0.04 mm, 0.045 mm, 0.05 mm, 0.055 mm, 0.06 mm, 0.065 mm, 0.07 mm, 0.075 mm, 0.08 mm, 0.085 mm, 0.09 mm, 0.095 mm, 0.1 mm, 0.105 mm, 0.11 mm, 0.115 mm, 0.12 mm, 0.125 mm, 0.13 mm, 0.135 mm, 0.14 mm, 0.145 mm, 0.15 mm, etc.

[0157] When D ≥ 0.015 mm, the residual thickness of the pressure relief groove 241 is greater, which is more conducive to reducing the risk of the pressure relief mechanism 24 opening the valve to relieve pressure in advance, improving the service life and reliability of the battery monomer 20. When D ≤ 0.15 mm, the residual thickness of the pressure relief groove 241 is not too large, so that the pressure relief mechanism 24 can open the pressure relief more timely when the battery monomer 20 is out of control, which is conducive to improving the timeliness of the pressure relief of the pressure relief mechanism 24. Therefore, when 0.015 mm ≤ D ≤ 0.15 mm, the service life, reliability and pressure relief timeliness of the battery monomer 20 can be considered.

[0158] Please refer to FIG. 3, FIG. 4, FIG. 5, FIG. 6 and FIG. 7, in some embodiments, the thickness of the end cover 22 is H2, which satisfies: 0.2 mm ≤ H2 ≤ 3 mm.

[0159] H2 represents the thickness of the end cover 22, that is, the distance between the outer surface of the end cover 22 and the inner surface of the end cover 22 in the thickness direction of the end cover 22. When measuring, the average value of multiple measurements can be taken as H2.

[0160] The thickness of the end cover 22 can be: H2 = 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3 mm, etc.

[0161] When H2 ≥ 0.2 mm, the thickness of the end cover 22 is large, the end cover 22 has high structural strength, which can reduce the risk of deformation of the end cover 22 under stress, which is conducive to reducing the risk of the pressure relief mechanism 24 opening the valve to relieve pressure in advance, and is conducive to improving the service life and reliability of the battery monomer 20. When H2 ≤ 3 mm, the thickness of the end cover 22 is not too large, which is conducive to controlling the manufacturing cost of the battery monomer 20. Therefore, when 0.2 mm ≤ H2 ≤ 3 mm, the service life, reliability and manufacturing cost of the battery monomer 20 can be considered.

[0162] Optionally, 0.3 mm ≤ H2 ≤ 2.5 mm.

[0163] The thickness of the end cover 22 can be: H2= 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, etc.

[0164] When H2≥ 0.3mm, the thickness of the end cover 22 is greater, the end cover 22 has higher structural strength, and is more capable of reducing the risk of deformation of the end cover 22 under stress, which is conducive to reducing the risk of the pressure relief mechanism 24 opening the valve to relieve pressure in advance, and is conducive to improving the service life and reliability of the battery monomer 20. When H2≤ 2.5mm, the thickness of the end cover 22 is not too large, which is more conducive to controlling the manufacturing cost of the battery monomer 20. Therefore, when 0.3mm≤ H2≤ 2.5mm, the service life, reliability and manufacturing cost of the battery monomer 20 can be better balanced.

[0165] In some embodiments, the pressure relief mechanism 24 is located at one end of the pressure relief hole 223 facing the shell 21.

[0166] In the thickness direction of the end cover 22, the pressure relief hole 223 has two opposite ends, one end faces the shell 21, the other end faces away from the shell 21, and the pressure relief mechanism 24 is arranged at one end of the pressure relief hole 223 facing the shell 21.

[0167] Optionally, the battery monomer 20 includes a protective piece 26, which is arranged at one end of the pressure relief hole 223 facing away from the shell 21 and covers the pressure relief hole 223.

[0168] When the pressure relief mechanism 24 is arranged at one end of the pressure relief hole 223 facing the shell 21, the risk of the pressure relief mechanism 24 being affected by external force is smaller, which is conducive to reducing the risk of the pressure relief mechanism 24 opening the valve to relieve pressure in advance, and is conducive to improving the service life and reliability of the battery monomer 20.

[0169] Please refer to FIG. 3, FIG. 4, FIG. 5, FIG. 6 and FIG. 7, in some embodiments, the end cover 22 has a first surface 225 facing the shell 21, the first surface 225 is provided with a groove 224, and the groove 224 is in communication with the pressure relief hole 223. The pressure relief mechanism 24 is partially contained in the groove 224, and the part of the pressure relief mechanism 24 contained in the groove 224 is welded with the end cover 22.

[0170] The end cover 22 has a first surface 225 facing the shell 21, which is also the inner surface of the end cover 22. The first surface 225 is provided with a groove 224, which is recessed from the first surface 225 to the direction away from the inside of the shell 21.

[0171] Optionally, the groove 224 is an annular groove, and the groove 224 is arranged around the pressure relief hole 223 and communicates with the pressure relief hole 223.

[0172] Part of the pressure relief mechanism 24 is accommodated in the groove 224, and the part of the pressure relief mechanism 24 accommodated in the groove 224 is welded to the end cover 22. For example, the outer circumferential surface of the pressure relief mechanism 24 can be welded to the groove side surface of the groove 224 to form a welding mark part 242, or the outer circumferential surface of the pressure relief mechanism 24 can be welded to the first surface 225 to form a welding mark part 242.

[0173] By arranging the groove 224 on the end cover 22 and accommodating part of the pressure relief mechanism 24 in the groove 224, on the one hand, the groove 224 can position the pressure relief mechanism 24, thereby facilitating the welding of the pressure relief mechanism 24 to the end cover 22. On the other hand, the groove bottom wall of the groove 224 can support the pressure relief mechanism 24, so that the pressure relief mechanism 24 and the end cover 22 are not easy to be welded through when welding.

[0174] Please refer to FIG. 3, FIG. 4, FIG. 5, FIG. 6 and FIG. 7. In some embodiments, the part of the pressure relief mechanism 24 accommodated in the groove 224 has a second surface 243 facing the shell 21. The distance between the first surface 225 and the second surface 243 along the thickness direction of the end cover 22 is L, which satisfies: L≤0.15mm.

[0175] L represents the distance between the first surface 225 and the second surface 243 along the thickness direction of the end cover 22. L represents the height difference between the part of the pressure relief mechanism 24 accommodated in the groove 224 and the first surface 225.

[0176] The distance between the first surface 225 and the second surface 243 along the thickness direction of the end cover 22 can be: L=0.15mm, 0.14mm, 0.13mm, 0.12mm, 0.11mm, 0.1mm, 0.09mm, 0.08mm, 0.07mm, 0.06mm, 0.05mm, 0.04mm, 0.03mm, 0.02mm, 0.01mm, 0.

[0177] By making the height difference between the first surface 225 and the second surface 243 along the thickness direction of the end cover 22 less than or equal to 0.15mm, the welding quality of the pressure relief mechanism 24 and the end cover 22 is improved.

[0178] Please refer to FIG. 8, which is a sectional view of the end cover 22 provided by some other embodiments of the present application. In some other embodiments, the first surface 225 and the second surface 243 are flush.

[0179] The first surface 225 and the second surface 243 are flush, that is, L=0.

[0180] When the first surface 225 and the second surface 243 are flush, the pressure relief mechanism 24 and the end cover 22 can be welded by means of butt welding. The heat of butt welding is small, which is conducive to reducing the risk of cracking of the pressure relief mechanism 24.

[0181] Please refer to FIG. 3, FIG. 4, FIG. 5, FIG. 7 and FIG. 8. In some embodiments, the end cover 22 includes a body part 221 and a support part 222, and the pressure relief hole 223 is arranged on the support part 222. The support part 222 and the body part 221 jointly define a groove 224 that communicates with the pressure relief hole 223. The pressure relief mechanism 24 is partially accommodated in the groove 224 and abuts against the support part 222. The pressure relief mechanism 24 is welded to the body part 221.

[0182] The body part 221 is connected to the support part 222. The support part 222 can serve as a bottom wall of the groove 224, and the body part 221 can serve as a side wall of the groove 224. The support part 222 encloses the pressure relief hole 223, and the pressure relief hole 223 communicates with the groove 224.

[0183] The pressure relief mechanism 24 is partially accommodated in the groove 224, the support part 222 abuts against the part of the pressure relief mechanism 24 accommodated in the groove 224, and the part of the pressure relief mechanism 24 accommodated in the groove 224 is welded to the body part 221.

[0184] The support part 222 and the body part 221 jointly define the groove 224, and the pressure relief mechanism 24 is accommodated in the groove 224. On the one hand, the groove 224 can position the pressure relief mechanism 24, thereby facilitating the welding of the pressure relief mechanism 24 to the body part 221. On the other hand, the support part 222 can support the pressure relief mechanism 24, so that the pressure relief mechanism 24 and the body part 221 are not easily welded through when they are welded.

[0185] In some embodiments, the support part 222 and the body part 221 are integrally formed.

[0186] Integrally formed means that the support part 222 and the body part 221 are an integral structure when they are provided. For example, the support part 222 can be formed on the body part 221 by stamping or cold heading.

[0187] By integrally forming the support part 222 and the body part 221, the end cover 22 has better structural strength, which is conducive to improving the reliability of the battery monomer 20.

[0188] Please refer to FIG. 3, FIG. 4, FIG. 5, FIG. 7 and FIG. 8. In some embodiments, along the thickness direction of the end cover 22, the thickness of the support part 222 is H3, which satisfies: 0.2mm≤H3≤3mm.

[0189] H3 represents the thickness of the support part 222 along the thickness direction of the end cover 22. When measuring, the average value can be obtained by measuring multiple times.

[0190] The thickness of the support portion 222 in the thickness direction of the end cover 22 can be H3 = 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3 mm, etc.

[0191] When H3≥0.2 mm, the thickness of the support portion 222 is large, which can reduce the risk of welding through when welding the pressure relief mechanism 24 and the body portion 221. When H3≤3 mm, the thickness of the support portion 222 is not too large, on the one hand, which can reduce the occupation of the internal space of the battery monomer 20 or the battery 100, and improve the energy density of the battery 100. On the other hand, it can reduce material consumption and reduce the cost of the battery monomer 20. Therefore, when 0.2 mm≤H3≤3 mm, both the risk of welding through when welding can be reduced, and the energy density of the battery 100 can be improved.

[0192] Optionally, 0.3 mm≤H3≤2.5 mm.

[0193] The thickness of the support portion 222 in the thickness direction of the end cover 22 can be H3 = 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, etc.

[0194] When H3≥0.3 mm, the thickness of the support portion 222 is larger, which can further reduce the risk of welding through when welding the pressure relief mechanism 24 and the body portion 221. When H3≤2.5 mm, the thickness of the support portion 222 is not too large, on the one hand, which can reduce the occupation of the internal space of the battery monomer 20 or the battery 100, and improve the energy density of the battery 100. On the other hand, it can reduce material consumption and reduce the cost of the battery monomer 20. Therefore, when 0.3 mm≤H3≤2.5 mm, both the risk of welding through when welding can be reduced, and the energy density of the battery 100 can be improved.

[0195] In some embodiments, the shell 21 and the end cover 22 are both made of steel.

[0196] The shell 21 and the end cover 22 can both be stainless steel, and the shell 21 and the end cover 22 can also both be carbon steel. In some embodiments, one of the shell 21 and the end cover 22 is carbon steel, and the other of the shell 21 and the end cover 22 is stainless steel.

[0197] When the shell 21 and the end cover 22 are both carbon steel, the shell 21 and the end cover 22 can both be low-carbon steel, the shell 21 and the end cover 22 can both be medium-carbon steel, or the shell 21 and the end cover 22 can both be high-carbon steel. In some embodiments, one of the shell 21 and the end cover 22 is medium-carbon steel, and the other of the shell 21 and the end cover 22 is low-carbon steel or high-carbon steel.

[0198] Steel has high strength and low cost. By making the shell 21 and the end cover 22 both steel, the structural strength of the shell 21 and the end cover 22 can be improved, and the risk of deformation of the shell 21 and the end cover 22 under stress can be reduced, which is conducive to improving the reliability of the battery monomer 20. In addition, the shell 21 and the end cover 22 are made of the same material, so that the shell 21 and the end cover 22 are easier to weld, which is conducive to reducing the phenomenon of welding cracks in the shell 21 and the end cover 22, thereby reducing the risk of liquid leakage of the battery monomer 20 and improving the reliability of the battery monomer 20.

[0199] The embodiments of the present application also provide a battery 100, which includes the battery monomer 20 described above.

[0200] The embodiments of the present application also provide a use-electric-device, which includes the battery monomer 20 described above, and the battery monomer 20 is used to provide electric energy for the use-electric-device.

[0201] According to some embodiments of the present application, please refer to FIGS. 3-8.

[0202] This application provides a battery cell 20, which includes a housing 21, an end cap 22, an electrode assembly 23, and a pressure relief mechanism 24. The housing 21 has an accommodating space with an opening at one end, and the end cap 22 is connected to the housing 21 and closes the opening. The end cap 22 is provided with a pressure relief hole 223. The electrode assembly 23 is accommodated within the accommodating space. The pressure relief mechanism 24 is disposed on the end cap 22 and closes the pressure relief hole 223. The pressure relief mechanism 24 is configured to release the pressure inside the battery cell 20. The pressure relief mechanism 24 is made of steel or nickel, and the end cap 22 is made of steel. The pressure relief mechanism 24 is welded to the end cap 22. By disposing of the pressure relief mechanism 24 on the end cap 22 during manufacturing, the pressure relief mechanism 24 can be connected to the end cap 22 first, and then the end cap 22 can be connected to the housing 21, which simplifies manufacturing and reduces manufacturing costs. Furthermore, the larger space on the outer side of the end cap 22 facilitates pressure relief by the pressure relief mechanism 24. By making the pressure relief mechanism 24 of steel or nickel, and the end cap 22 of steel, the structural strength of the end cap 22 and the pressure relief mechanism 24 can be effectively improved, reducing the risk of deformation due to stress. This helps reduce the risk of premature pressure release by the pressure relief mechanism 24, and improves the service life and reliability of the battery cell 20. Furthermore, the steel or nickel-based pressure relief mechanism 24 is easier to weld to the steel end cap 22, reducing the likelihood of welding cracks and thus lowering the risk of leakage from the battery cell 20, thereby improving its reliability.

[0203] Both the pressure relief mechanism 24 and the end cap 22 are made of steel. Steel has high strength and low cost. By using steel for both the pressure relief mechanism 24 and the end cap 22, the structural strength of the end cap 24 and the pressure relief mechanism 24 can be improved, reducing the risk of deformation under stress. This helps reduce the risk of premature valve opening and pressure release by the pressure relief mechanism 24, and improves the service life and reliability of the battery cell 20. In addition, using the same material for the pressure relief mechanism 24 and the end cap 22 makes welding easier, reducing the possibility of welding cracks between the pressure relief mechanism 24 and the end cap 22, thereby reducing the risk of leakage from the battery cell 20 and improving its reliability.

[0204] The pressure relief mechanism 24 and the end cover 22 are made of 304 stainless steel. The 304 stainless steel has the advantages of corrosion resistance, high temperature resistance, and good machining performance. The pressure relief mechanism 24 and the end cover 22 made of 304 stainless steel have high strength, can reduce the risk of deformation of the end cover 22 and the pressure relief mechanism 24 under stress, are beneficial to reduce the risk of early valve pressure relief of the pressure relief mechanism 24, and are beneficial to improve the service life and reliability of the battery monomer 20. Moreover, the pressure relief mechanism 24 and the end cover 22 made of 304 stainless steel are not easy to corrode, which is beneficial to improve the service life of the battery monomer 20.

[0205] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Various modifications and changes can be made by those skilled in the art based on the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, wherein, The battery cell comprises: a shell having a containing space with one end being open; an end cover connected to the shell and closing the opening, the end cover being provided with a pressure relief hole; an electrode assembly contained in the containing space; a pressure relief mechanism provided on the end cover and closing the pressure relief hole, the pressure relief mechanism being configured to be able to release the pressure inside the battery cell; the material of the pressure relief mechanism comprises steel or nickel, the material of the end cover comprises steel, and the pressure relief mechanism is welded to the end cover.

2. The battery cell of claim 1, wherein, Both the pressure relief mechanism and the end cover are made of steel.

3. The battery cell of claim 2, wherein, Both the pressure relief mechanism and the end cover are made of 304 stainless steel.

4. The battery cell of any one of claims 1-3, wherein, The pressure relief mechanism is in the form of a sheet, and the thickness of the pressure relief mechanism is H1, satisfying 0.05mm≤H1≤0.5mm.

5. The battery cell of claim 4, wherein, 0.05mm≤H1≤0.3mm.

6. The battery cell of any one of claims 1-5, wherein, The pressure relief mechanism is provided with a pressure relief groove, and the pressure relief mechanism is configured to be split along at least a part of the pressure relief groove when the battery cell is relieved of pressure.

7. The battery cell of claim 6, wherein, The residual thickness of the pressure relief groove is D, satisfying 0.01mm≤D≤0.3mm.

8. The battery cell of claim 7, wherein, 0.015mm≤D≤0.15mm.

9. The battery cell of any one of claims 1-8, wherein, The thickness of the end cover is H2, satisfying 0.2mm≤H2≤3mm.

10. The battery cell of claim 9, wherein, 0.3mm≤H2≤2.5mm.

11. The battery cell of any one of claims 1-10, wherein, The pressure relief mechanism is located at one end of the pressure relief hole facing the shell.

12. The battery cell of claim 11, wherein, The end cover has a first surface facing the shell, and the first surface is provided with a groove in communication with the pressure relief hole. The pressure relief mechanism is partially contained in the groove, and the part of the pressure relief mechanism contained in the groove is welded to the end cover.

13. The battery cell of claim 12, wherein, The part of the pressure relief mechanism contained in the groove has a second surface facing the shell, and the distance between the first surface and the second surface in the thickness direction of the end cover is L, satisfying L≤0.15mm.

14. The battery cell of claim 13, wherein, The first surface and the second surface are flush.

15. The battery cell of any one of claims 1-14, wherein, The end cover comprises a body portion and a support portion, the pressure relief hole is provided on the support portion, and the support portion and the body portion jointly define a groove in communication with the pressure relief hole. The pressure relief mechanism is partially contained in the groove and abuts against the support portion, and the pressure relief mechanism is welded to the body portion.

16. The battery cell of claim 15, wherein, The support portion is integrally formed with the body portion.

17. The battery cell of claim 15 or 16, wherein, In the thickness direction of the end cover, the thickness of the support portion is H3, satisfying 0.2mm≤H3≤3mm.

18. The battery cell of claim 17, wherein, 0.3mm≤H3≤2.5mm.

19. The battery cell of any one of claims 1-18, wherein, Both the shell and the end cover are made of steel.

20. A battery, wherein, The battery cell according to any one of claims 1-19.

21. An electrical device, comprising: The battery cell according to any one of claims 1-19 is used to provide electric energy for the electric device.

Images