Battery cell, battery, and electric device

Abstract

The present application relates to the technical field of batteries. Disclosed in the present application are a battery cell, a battery, and an electric device. The battery cell comprises a shell and a pressure relief notch, wherein the shell comprises a first wall; and the pressure relief notch is arranged in the first wall and comprises an arc section and a first extension section, the arc section having a first end, and the first extension section being connected to the first end and extending from the first end in the direction approaching the central axis of the arc section. In the battery cell according to the embodiments of the present application, the tearing range and tearing direction of a torn part on the shell can be controlled, and partial valve opening can be achieved after thermal runaway of the battery cell and tearing of the pressure relief notch, thereby reducing the probability of tearing over a large area of the shell and reducing the damage to the battery cell caused by uncontrollable cracks.

Description

Battery cells, batteries and electrical equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application 2023116416764, filed on November 30, 2023, entitled “Battery Cell, Battery and Electrical Equipment,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0004] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the sustainable development of the automotive industry. For electric vehicles, battery technology is a key factor in their development.

[0005] Batteries are widely used in portable electronic devices, electric vehicles, power tools, drones, energy storage devices, and other fields. During battery use, reliability is an important issue that cannot be ignored. Therefore, improving battery reliability is a pressing technical challenge in battery technology.

[0006] Summary of the Invention

[0007] The present application provides a battery cell, a battery, and an electrical device, which can reduce the damage to the outer shell of the battery cell during thermal runaway, reduce the impact on other battery cells, and thus improve the reliability of the battery.

[0008] This application is achieved through the following technical solutions:

[0009] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell and a pressure relief notch, the shell comprising a first wall; the pressure relief notch is arranged on the first wall, the pressure relief notch comprising an arc segment and a first extension segment, the arc segment having a first end, the first extension segment being connected to the first end and extending from the first end toward a direction close to the central axis of the arc segment.

[0010] According to the battery cell of the embodiment of the present application, the pressure relief notch includes an arc segment and a first extension segment. By extending the first extension segment from the first end toward the direction close to the central axis of the arc segment, the arc segment can reduce the stress concentration of the pressure relief notch during processing. When the battery cell undergoes thermal runaway and the internal high-pressure gas tears the pressure relief notch, the first extension segment can guide the crack toward the direction close to the central axis of the arc segment, so that the size of the torn part on the outer shell can be controlled. Of course, the first extension segment can also make the tearing direction of the crack controllable. Therefore, after the battery cell undergoes thermal runaway and the pressure relief notch is torn, local valve opening can be achieved, reducing the probability of large-scale tearing of the outer shell. Both the tearing direction and the tearing range of the crack are controllable, reducing the damage to the battery cell caused by the uncontrollable crack.

[0011] According to some embodiments of the present application, the pressure relief notch further includes a second extension segment, the arc segment having a second end, the second extension segment being connected to the second end and extending from the second end toward the central axis. In this embodiment, the second extension segment can guide the crack toward the central axis of the arc segment. The second extension segment and the first extension segment can cause the crack to converge, thereby controlling the tearing direction and range of the crack and achieving partial opening of the valve of the shell.

[0012] According to some embodiments of the present application, the first extension segment and the second extension segment are symmetrical about the central axis. In this embodiment, the extension length of the first extension segment is the same as the extension length of the second extension segment. If both the first extension segment and the second extension segment are straight lines, the angle between the extension line of the first extension segment and the central axis is the same as the angle between the extension line of the second extension segment and the central axis. As a result, the tearing direction and tearing range of the cracks guided by the first extension segment and the second extension segment can remain roughly consistent, reducing the probability of uncontrollable cracks and further achieving stable partial valve opening of the shell.

[0013] According to some embodiments of the present application, the length of the first extension section is the same as the length of the second extension section. In the above solution, the valve opening area of ​​the crack at the first extension section is substantially the same as the valve opening area of ​​the crack at the second extension section, and the subsequent valve opening area of ​​the crack on the shell after being guided by the first extension section and the subsequent valve opening area of ​​the crack on the shell after being guided by the second extension section are also substantially the same, thereby ensuring the stability of the crack tearing range and reducing the probability of uncontrollable cracks.

[0014] According to some embodiments of the present application, the first extension segment and the second extension segment are both straight segments, and the angle between the extension line of the first extension segment and the central axis is the same as the angle between the extension line of the second extension segment and the central axis. In this embodiment, the cracks guided by the first extension segment and the cracks guided by the second extension segment can intersect at the central axis, thereby achieving partial opening of the valve of the housing.

[0015] According to some embodiments of the present application, the length of the first extension section is shorter than the length of the second extension section. In the above solution, the subsequent valve opening area of ​​the outer shell after the crack is guided through the first extension section is larger than the subsequent valve opening area of ​​the outer shell after the crack is guided through the second extension section. Therefore, after thermal runaway of the battery cell occurs, the high-pressure gas in the outer shell can be quickly discharged.

[0016] According to some embodiments of the present application, the first extension segment and the second extension segment are both straight segments, and the angle between the extension line of the first extension segment and the central axis is different from the angle between the extension line of the second extension segment and the central axis. In this embodiment, the subsequent valve opening area of ​​the housing after the crack is guided through the first extension segment is different from the subsequent valve opening area of ​​the housing after the crack is guided through the second extension segment. Therefore, after thermal runaway of the battery cell occurs, the high-pressure gas in the housing can be quickly discharged through the larger valve opening area on the housing.

[0017] According to some embodiments of the present application, the central angle of the arc segment is α, which satisfies: 180°≤α<360°. In the above scheme, when α≥180°, the area enclosed by the arc segment is sufficient, so that when thermal runaway occurs in the battery cell, the crack tears the shell along the arc segment, and the crack on the arc segment can quickly discharge the high-pressure gas in the shell; when α<360°, the pressure relief notch is an unclosed annular structure with an opening on the pressure relief notch, so that the crack can tear the shell along the direction of the opening, making the tearing direction and tearing range of the crack controllable, thereby achieving local valve opening of the crack on the shell. When 180°≤α<360°, the crack range torn along the arc segment is sufficient, the high-pressure gas in the shell can be quickly discharged, and at the same time, the pressure relief notch has an opening, which can guide the tearing direction and tearing range of the crack, thereby achieving local valve opening of the crack on the shell.

[0018] According to some embodiments of the present application, 210°≤α≤330°. In the above scheme, when α≥210°, the area enclosed by the arc segment is further increased, so that when thermal runaway occurs in the battery cell, the crack tears the shell along the arc segment, and the tearing range of the crack can enable the high-pressure gas in the shell to be discharged more quickly; when α≤330°, the pressure relief notch is an unclosed annular structure with an opening and a larger opening range, so that the crack can tear the shell along the direction of the opening. Not only is the tearing direction and tearing range of the crack controllable, but the tearing range of the crack is also larger, and the high-pressure gas in the shell can be discharged more quickly. When 210°≤α≤330°, the discharge speed of the high-pressure gas in the shell can be further increased. At the same time, the opening size on the arc segment is larger, so that the crack can be guided to a larger tearing range in the shell. Therefore, the opening can not only guide the tearing direction and tearing range of the crack, but also further increase the discharge speed of the high-pressure gas in the shell.

[0019] According to some embodiments of the present application, the first extension segment is tangent to the arc segment; and / or the second extension segment is tangent to the arc segment. In the above scheme, the crack on the arc segment can be extended and torn very smoothly along the tangent line at the first end of the arc segment, reducing the obstruction of the crack tearing process, making the crack tearing smoother and more controllable, and reducing the stress concentration during the tearing process; or / and the crack on the arc segment can be extended and torn very smoothly along the tangent line at the second end of the arc segment, reducing the obstruction of the crack tearing process, making the crack tearing smoother and more controllable, and reducing the stress concentration during the tearing process.

[0020] According to some embodiments of the present application, the first extension segment is a straight segment; and / or the second extension segment is a straight segment. In the above scheme, on the one hand, the processing of the first extension segment can be made easier, and on the other hand, the tearing process of the crack on the straight segment is smoother, or in other words, the straight segment can better guide the crack to tear along the preset direction, thereby making the tearing direction and tearing range of the crack more controllable; and / or on the one hand, the processing of the second extension segment can be made easier, and on the other hand, the tearing process of the crack on the straight segment is smoother, or in other words, the straight segment can better guide the crack to tear along the preset direction, thereby making the tearing direction and tearing range of the crack more controllable.

[0021] According to some embodiments of the present application, the radius of the arc segment is R, satisfying the following: 1mm≤R≤20mm; the length of the straight segment is L1, satisfying the following: 0<L1≤20mm. This solution not only meets the pressure relief requirements of the battery cell in the event of thermal runaway, but also ensures that the pressure relief notch is not too large, affecting the overall structural strength of the housing.

[0022] According to some embodiments of the present application, 3mm≤R≤10mm, 1mm≤L1≤10mm. In the above solution, the pressure relief requirements of the battery cell during thermal runaway can be further met, and the range of the pressure relief notch can be limited to a small extent, thereby further ensuring the structural strength of the entire housing.

[0023] According to some embodiments of the present application, the condition 0 < L1 / R ≤ 2 is satisfied. In the above solution, the straight line segment is ensured to have sufficient length to guide the tearing direction and range of the crack, while also alleviating the negative impact on the structural strength of the housing caused by the excessive extension of the straight line segment, which results in an excessively large range of the pressure relief notch.

[0024] According to some embodiments of the present application, the condition 0.1 ≤ L1 / R ≤ 1 is satisfied. In the above solution, the straight line segment is ensured to have sufficient length to guide the tearing direction and range of the crack, while also further alleviating the negative impact on the structural strength of the housing caused by the excessive extension of the straight line segment, which results in an excessively large pressure relief notch.

[0025] According to some embodiments of the present application, the end of the first extension segment away from the arc segment and the end of the second extension segment away from the arc segment are spaced apart to form an opening. In the above solution, after a battery cell experiences thermal runaway, high-pressure gas will tear the pressure relief notch, and the crack can be torn along the direction of the opening toward the corner, so the direction of the crack can be adjusted to adjust the tearing direction of the crack.

[0026] According to some embodiments of the present application, the housing is flat, and the first wall is the wall of the housing in the thickness direction. In the above solution, the pressure relief notch is not provided on the small surface, but on the large surface of the housing. Therefore, the pressure relief notch is not constrained by the size of the small surface and can be designed to an appropriate size as needed. In addition, providing the pressure relief notch on the large surface can also reduce the difficulty of processing the pressure relief notch, thereby reducing the manufacturing cost of the pressure relief notch.

[0027] According to some embodiments of the present application, the pressure relief notch is provided in the corner area of ​​the first wall and the opening is oriented toward the corner area of ​​the first wall. In the above solution, the pressure relief notch is provided in the corner area of ​​the first wall. When thermal runaway occurs in the battery cell, the crack can tear the outer shell under the guidance of the pressure relief notch. Since the pressure relief notch is provided in the corner area of ​​the first wall, the tearing area of ​​the crack is also mainly concentrated in the corner area of ​​the first wall, thereby reducing the probability of the crack damaging other areas of the first wall, making it possible to recycle the outer shell of the battery cell after thermal runaway occurs.

[0028] When the crack tears the shell along the pressure relief notch, it can tear along the direction of the opening, and the tearing direction of the crack is toward the corner of the first wall, thereby reducing the probability of the crack moving toward the middle area of ​​the first wall and reducing the probability of the first wall being completely torn, so that the shell can be recycled.

[0029] According to some embodiments of the present application, the first wall includes a first edge and a second edge, and the first edge and the second edge intersect to form a corner of the first wall; the shortest distance between the center of the pressure relief notch and the first edge is L2, and the length of the second edge is L, satisfying: 0<L2<L / 2; the shortest distance between the center of the pressure relief notch and the second edge is W1, and the length of the first edge is W, satisfying: 0<W1<W / 2.

[0030] In the above solution, the center of the pressure relief notch is close to a corner defined by the first and second edges. Therefore, the tearing area of ​​the crack is mainly concentrated in the corner area of ​​the first wall, which can reduce the probability of the crack damaging other areas of the first wall and make it possible to recycle the battery housing after thermal runaway occurs.

[0031] According to some embodiments of the present application, the shortest distance between the end of the first extension segment away from the arc segment and the first edge is L3, the length of the second edge is L, and the following conditions are met: 0<L3<L / 2; the shortest distance between the end of the second extension segment away from the arc segment and the second edge is W2, the length of the first edge is W, and the following conditions are met: 0<W2<W / 2.

[0032] In the above solution, the shortest distance between the end of the second extension segment distal from the arc segment and the second edge, together with the length of the first edge, satisfies the aforementioned conditions. Therefore, the opening is oriented toward the corner defined by the first and second edges. When the shell is torn along the pressure relief notch, the crack can tear in the direction of the opening, i.e., toward the corner of the first wall. This reduces the probability of the crack moving toward the middle region of the first wall, reduces the probability of the first wall being completely torn, and allows the shell to be recycled.

[0033] According to some embodiments of the present application, the pressure relief notch is provided in the central region of the first wall. In the above solution, the pressure relief notch is provided in the central region of the first wall. At the same time, because the pressure relief notch has an opening, when a battery cell experiences thermal runaway, cracks will extend along the pressure relief notch and along the area toward which the opening faces. Therefore, the cracks will not tear randomly and will not destroy a large area of ​​the first wall, but will be guided to a predetermined area.

[0034] According to some embodiments of the present application, the thickness of the first wall is T, which satisfies the following conditions: 0.03mm≤T≤0.6mm. This solution not only ensures that the first wall is sufficiently thin, thereby increasing the energy density of the battery cell in the thickness direction of the first wall, but also ensures that the first wall has sufficient structural strength to facilitate subsequent laser etching of pressure relief notches.

[0035] According to some embodiments of the present application, T satisfies the following: 0.05mm≤T≤0.2mm. This solution not only ensures that the thickness of the first wall is sufficiently thin, further increasing the energy density of the battery cell in the thickness direction of the first wall, but also further ensures the structural strength of the first wall, facilitating subsequent laser etching of pressure relief notches thereon.

[0036] According to some embodiments of the present application, the outer shell includes a shell and a cover plate, the shell includes a bottom wall and a peripheral side wall, one end of the peripheral side wall is connected to the outer peripheral edge of the bottom wall, and the other end of the peripheral side wall forms a first opening, and the cover plate closes the first opening; wherein the first wall is the cover plate or the bottom wall.

[0037] In the above solution, the housing is formed from two separate components: a shell and a cover. The shell and cover can be metal and secured together by welding. The first wall is the cover or bottom wall, so the pressure relief notch is provided on the cover or bottom wall. For example, if the battery cell is flat and the cover and bottom wall are opposite in thickness, the pressure relief notch can be provided on the large surface of the housing.

[0038] In a second aspect, embodiments of the present application provide a battery comprising the aforementioned battery cell. In the aforementioned solution, since the battery according to embodiments of the present application is provided with the aforementioned battery cell, the pressure relief notch can be torn in the event of thermal runaway of the battery cell. The size and direction of the torn portion of the outer shell can be controlled, achieving localized valve opening and reducing the chance of extensive outer shell tearing.

[0039] In a third aspect, embodiments of the present application provide an electrical device comprising the aforementioned battery cell or battery, wherein the battery cell or battery is configured to provide electrical energy. In the aforementioned solution, since the electrical device according to embodiments of the present application is provided with the aforementioned battery cell or battery, the safety of the electrical device is improved.

[0040] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0042] FIG1 is a schematic diagram of a vehicle provided in an embodiment of the present application;

[0043] FIG2 is an exploded view of a battery provided in an embodiment of the present application;

[0044] FIG3 is an exploded view of a battery cell provided in an embodiment of the present application;

[0045] FIG4 is a schematic diagram of a first wall provided in an embodiment of the present application;

[0046] FIG5 is a partial enlarged schematic diagram of circle A in FIG4 ;

[0047] FIG6 is a schematic diagram of another first wall provided in an embodiment of the present application;

[0048] FIG7 is a partial cross-sectional view of the first wall of an embodiment of the present application;

[0049] FIG8 is a schematic diagram of another first wall provided in an embodiment of the present application;

[0050] FIG9 is a schematic diagram of another first wall provided in an embodiment of the present application.

[0051] Icon: vehicle 1000, battery 100, controller 200, motor 300, box 10, battery cell 20, first sub-box 11, second sub-box 12, outer shell 21, electrode assembly 22, electrode terminal 25, shell 211, bottom wall 211a, peripheral side wall 211b, cover plate 212, first wall 212a, pressure relief notch 201, arc segment 201a, first extension segment 201b, second extension segment 201c, central axis 202, opening 203, first edge 204, second edge 205. DETAILED DESCRIPTION

[0052] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0053] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0054] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0055] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0056] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0057] The term "multiple" in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0058] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0059] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0060] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0061] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0062] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0063] The battery cells may be, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, and the like.

[0064] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0065] In some embodiments, the positive electrode may be a positive electrode sheet, which may 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 surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

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

[0068] As an example, the positive electrode active material may 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 positive electrode active materials for batteries may also be used.

[0069] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0070] As an example, the negative electrode current collector may be a metal foil or a composite current collector. For example, the metal foil may be silver-plated aluminum, silver-plated stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium.

[0071] In some embodiments, the negative electrode current collector has two opposite surfaces in its thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0072] As an example, the negative electrode active material may be a negative electrode active material for a battery that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0073] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical and mechanical stability can be selected.

[0074] As an example, the primary material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0075] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0076] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel, or solid. Liquid electrolytes include an electrolyte salt and a solvent.

[0077] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium bisoxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0078] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl 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, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may 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, methyltetrahydrofuran, diphenyl ether and crown ether.

[0079] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0080] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0081] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, or the like.

[0082] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0083] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0084] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0085] In some embodiments, the electrode assembly is a laminate structure.

[0086] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0087] In some embodiments, the housing includes an end cap and a shell. The shell has an opening, and the end cap closes the opening to form a sealed space for accommodating the electrode assembly, electrolyte, and other substances. The shell may have one or more openings. One or more end caps may also be provided.

[0088] In some embodiments, the housing is provided with at least one electrode terminal, which is electrically connected to a tab of the electrode assembly. The electrode terminal may be directly connected to the tab or indirectly connected to the tab via an adapter. The electrode terminal may be provided on an end cap or on the housing.

[0089] In some embodiments, the housing is provided with an explosion-proof valve for releasing the internal pressure of the battery cell.

[0090] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, and a polygonal battery. The polygonal battery is, for example, a hexagonal battery, etc. There is no special limitation in the embodiments of the present application.

[0091] The battery mentioned 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.

[0092] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0093] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0094] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0095] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0096] Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability and low self-discharge coefficient. They are an important part of the development of new energy today.

[0097] The development of battery technology must take into account multiple design factors at the same time, such as energy density, discharge capacity, charge and discharge rate and other performance parameters. In addition, the assembly efficiency of the battery also needs to be considered.

[0098] The battery cells disclosed in the embodiments of the present application can be used, but are not limited to, in electrical equipment such as vehicles, ships, or aircraft. A power supply system comprising the battery cells and batteries disclosed in the present application can be used to form the electrical equipment.

[0099] The embodiments of the present application provide an electrical device that uses a battery cell as a power source. The electrical device may be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0100] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0101] Please refer to Figure 1, which is a schematic diagram of a vehicle provided in the first embodiment of the present application. Vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can be used as an operating power source for the vehicle 1000, for the circuit system of the vehicle 1000, such as for the working power requirements during the startup, navigation and operation of the vehicle 1000.

[0102] The vehicle 1000 may 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, to meet the power requirements of the vehicle 1000 during startup, navigation, and driving.

[0103] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0104] Please refer to Figure 2, which is an exploded view of the battery provided in the first embodiment of the present application. The battery 100 includes a housing 10 and a battery cell 20, with the battery cell 20 being housed within the housing 10. The housing 10 is used to provide a storage space for the battery cell 20, and the housing 10 can adopt a variety of structures. In some embodiments, the housing 10 can include a first sub-housing 11 and a second sub-housing 12, which cover each other and together define a storage space for accommodating the battery cell 20. The second sub-housing 12 can be a hollow structure with one end open, and the first sub-housing 11 can be a plate-like structure, with the first sub-housing 11 covering the open side of the second sub-housing 12, so that the first sub-housing 11 and the second sub-housing 12 jointly define a storage space. The first sub-housing 11 and the second sub-housing 12 can also be hollow structures with one end open, with the open side of the first sub-housing 11 covering the open side of the second sub-housing 12.

[0105] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0106] The battery cell 20 may be a secondary battery or a primary battery; the battery cell 20 may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto.

[0107] Please refer to Figure 3, which is an exploded view of a battery cell provided in some embodiments of the present application. As shown in Figure 3, a battery cell 20 includes a housing 21, an electrode assembly 22, and electrode terminals 25. Housing 21 includes a shell 211 and a cover 212. Shell 211 has an opening, and cover 212 closes the opening, isolating the internal environment of battery cell 20 from the external environment.

[0108] The housing 211 is a component used to cooperate with the cover plate 212 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 22, electrolyte, and other components. The housing 211 and the cover plate 212 can be independent components. The housing 211 can be of various shapes and sizes. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the electrode assembly 22. The housing 211 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0109] The cover plate 212 is a component that covers the opening of the housing 211 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the cover plate 212 can be adapted to the shape of the housing 211 to match the housing 211. Optionally, the cover plate 212 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This prevents the cover plate 212 from deforming when subjected to compression or collision, thereby providing the battery cell 20 with greater structural strength and improved reliability. Functional components such as electrode terminals can be provided on the cover plate 212. The electrode terminals can be used to electrically connect to the electrode assembly 22 to output or input electrical energy to the battery cell 20. The cover plate 212 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this is not particularly limited in the present embodiment. In some embodiments, an insulating structure can be provided on the inner side of the cover plate 212 to isolate the electrical connection components within the housing 211 from the cover plate 212 to reduce the risk of short circuits. For example, the insulating structure may be plastic, rubber, or the like.

[0110] The electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 22 may be contained in the housing 211. The electrode assembly 22 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The separator is used to separate the positive electrode sheet and the negative electrode sheet to avoid internal short circuits between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a tab. The positive tab and the negative tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0111] In existing technical solutions, pressure relief notches are provided on the outer shell of a battery cell. These notches are generally located on the side surfaces of the outer shell in the thickness direction and do not penetrate the outer shell in this direction. This results in relatively low structural strength in the portion of the outer shell where the pressure relief notches are provided. When a battery cell experiences thermal runaway, the pressure inside the outer shell increases rapidly in a short period of time, and the area where the pressure relief notches are located will be the first to tear.

[0112] However, the existing pressure relief notches do not have a guiding effect, so the tearing range and tearing direction of the pressure relief notches during the tearing process are uncontrollable. For example, if the pressure relief notches are located in the center area of ​​the shell side wall, when the battery cell experiences thermal runaway, the cracks will not be guided to the preset position, but will extend irregularly in a direction away from the center area, with multiple cracks diverging away from the center area, completely destroying most of the side wall where the pressure relief notches are located. Alternatively, if the pressure relief notches are located in the corner areas of the shell side wall, when the battery cell experiences thermal runaway, the cracks may extend toward the center area of ​​the side wall, thereby destroying most of the side wall. Therefore, since the existing pressure relief notches do not have a guiding effect, the cracks will cause extensive damage to the shell, affecting the recycling of the shell.

[0113] In addition, since the tearing range and tearing direction of the cracks are uncontrollable, high-pressure gas will be discharged from the cracks in a disorderly manner, which may cause damage to other battery cells.

[0114] To this end, the present application proposes a battery cell, on which a pressure relief notch is provided with controllable tearing direction or tearing range after thermal runaway of the battery occurs, thereby enabling partial valve opening.

[0115] As shown in FIG. 4 and FIG. 6 , the battery cell 20 according to the embodiment of the present application may include a housing 21 and a pressure relief notch 201 .

[0116] The outer shell 21 can isolate the external environment and the internal environment of the battery cell 20. The outer shell 21 can be a metal part, and of course, it can also be an insulating part.

[0117] The housing 21 may define a receiving space, in which the electrode assembly 22 and an electrolyte for soaking the electrode assembly may be accommodated.

[0118] The housing 21 may include a first wall 212a, which may be one of the walls of the housing 21. This application does not limit the specific position or function of the first wall 212a on the housing 21. For example, the first wall 212a may be a wall of the housing 21 on which the electrode terminals are disposed, or the housing 21 may be a flat structure, with the first wall 212a being a wall of the housing 21 in the thickness direction.

[0119] The pressure relief notch 201 is provided on the first wall 212a. The pressure relief notch 201 is generally provided on a side surface of the first wall 212a in the thickness direction. For example, the pressure relief notch 201 can be provided on an inner side surface and / or an outer side surface of the first wall 212a.

[0120] The pressure relief notch 201 may be formed on the first wall 212 a by laser etching. The pressure relief notch 201 does not penetrate the first wall 212 a in the thickness direction of the first wall 212 a.

[0121] The structural strength of the portion of the first wall where the pressure relief notch 201 is provided is weaker than that of other portions. Therefore, after thermal runaway of the battery cell 20 occurs, the pressure relief notch will tear first, thereby quickly discharging the high-pressure gas in the housing 21 .

[0122] The pressure relief notch 201 is generally a groove structure, and the cross-sectional shape of the pressure relief notch 201 can be semicircular, trapezoidal or other shapes. This application does not limit the specific shape of the cross-sectional shape of the pressure relief notch 201.

[0123] The pressure relief notch 201 includes an arc segment 201a. As the name implies, the arc segment 201a is not a complete circle, but an arc segment corresponding to the central angle of a circle. The central angle and radius of the arc segment 201a can be adjusted as needed.

[0124] The arc segment 201 a has a first end, which may be one end of the arc segment 201 a in the length direction.

[0125] The arc segment 201a may further have a second end, which may be the other end of the arc segment 201a in the length direction.

[0126] The pressure relief notch 201 further includes a first extension segment 201b. The first extension segment 201b may be a straight line segment, an arc segment, or other special-shaped line segments (eg, serpentine, etc.). The specific type of the first extension segment 201b is not limited herein.

[0127] The first extension segment 201 b may be connected to the first end, and the first extension segment 201 b may extend from the first end toward a direction close to the central axis 202 of the arc segment 201 a.

[0128] It should be noted that the central axis 202 of the arc segment 201 a can divide the arc segment 201 a into two sub-arc segments, and the two sub-arc segments are symmetrical about the central axis 202 of the arc segment 201 a.

[0129] Therefore, the extension line of the first extension segment 201 b extending in a direction away from the arc segment 201 a will eventually intersect with the central axis 202 of the arc segment 201 a .

[0130] The pressure relief notch 201 may further include a second extension segment 201c. The second extension segment 201c may be a straight line segment, an arc segment, or other special-shaped line segments (eg, serpentine, etc.). The specific type of the second extension segment 201c is not limited herein.

[0131] The second extension segment 201c may be connected to the second end, and the second extension segment 201c may extend from the second end toward a direction close to the central axis 202 of the arc segment 201a.

[0132] Therefore, the extension line of the second extension segment 201 c extending in a direction away from the arc segment 201 a will eventually intersect with the central axis 202 of the arc segment 201 a .

[0133] The first extension segment 201b and the second extension segment 201c can also be symmetrical about the central axis 202 of the arc segment 201a. Of course, the first extension segment 201b and the second extension segment 201c can also be asymmetrical about the central axis 202 of the arc segment 201a, as long as the first extension segment 201b extends from the first end toward the direction close to the central axis 202 of the arc segment 201a, and the second extension segment 201c extends from the second end toward the direction close to the central axis 202 of the arc segment 201a.

[0134] According to the battery cell of the embodiment of the present application, as shown in Figure 9, the pressure relief notch may include an arc segment 201a and a first extension segment 201b. By extending the first extension segment 201b from the first end toward the direction close to the central axis 202 of the arc segment, the arc segment 201a can reduce the stress concentration of the pressure relief notch 201 during processing. When the battery cell 20 undergoes thermal runaway and the internal high-pressure gas tears the pressure relief notch 201, the first extension segment 201b can guide the crack toward the direction close to the central axis 202 of the arc segment 201a, thereby making the size of the torn portion on the outer shell 21 controllable. Of course, the first extension segment 201b can also make the tearing direction of the crack controllable. Therefore, after the battery cell 20 undergoes thermal runaway and the pressure relief notch 201 is torn, local valve opening can be achieved, reducing the probability of large-scale tearing of the outer shell 21. The tearing direction and tearing range of the crack are both controllable, reducing the damage to the battery cell 20 caused by uncontrollable cracks.

[0135] According to the battery cell 20 of the embodiment of the present application, the pressure relief notch 201 includes an arc segment 201a, a first extension segment 201b and a second extension segment 201c. By extending the first extension segment 201b from the first end toward the direction close to the central axis 202 of the arc segment 201a and the second extension segment 201c from the second end toward the direction close to the central axis 202 of the arc segment 201a, the arc segment 201a can reduce the stress concentration of the pressure relief notch 201 during processing. When the battery cell 20 undergoes thermal runaway and the internal high-pressure gas tears the pressure relief notch 201, the first extension segment 201b and the second extension segment 201c can guide the crack toward the central axis close to the arc segment 201a. 202, so that the first extension segment 201b and the second extension segment 201c can guide the cracks on the shell 21 to gradually converge, so that the size of the torn part of the shell 21 can be controlled. Of course, the first extension segment 201b and the second extension segment 201c can also make the tearing direction of the cracks controllable. Therefore, after the battery cell 20 has thermal runaway and the pressure relief notch 201 is torn, local valve opening can be achieved, reducing the probability of large-scale tearing of the shell 21. The tearing direction and tearing range of the cracks are controllable, reducing the damage to the battery cell 20 caused by the uncontrollable cracks, and also reducing the disorderly discharge of high-pressure gas due to the uncontrollable cracks and the impact on other battery cells 20.

[0136] According to some embodiments of the present application, the first extension section 201b and the second extension section 201c are symmetrical about the central axis 202. For example, the extension length of the first extension section 201b and the extension length of the second extension section 201c are the same. If the first extension section 201b and the second extension section 201c are both straight lines, the angle between the extension line of the first extension section 201b and the central axis 202 is the same as the angle between the extension line of the second extension section 201c and the central axis 202. As a result, the tearing direction and tearing range of the cracks guided by the first extension section 201b and the second extension section 201c can remain generally consistent, reducing the probability of uncontrollable cracks and further achieving stable partial valve opening of the housing 21.

[0137] According to some embodiments of the present application, the length of the first extension segment 201b is the same as the length of the second extension segment 201c. It should be noted that the first extension segment 201b and the second extension segment 201c can both be straight segments, or both can be curved segments, or one of the first extension segment 201b and the second extension segment 201c can be a curved segment and the other a straight segment. As long as the length of the first extension segment 201b is the same as the length of the second extension segment 201c, it is within the scope of protection of the present application.

[0138] Therefore, the valve opening area of ​​the crack at the first extension section 201b is roughly the same as the valve opening area of ​​the crack at the second extension section 201c, and the subsequent valve opening area of ​​the crack on the shell 21 after being guided by the first extension section 201b and the subsequent valve opening area of ​​the crack on the shell 21 after being guided by the second extension section 201c are also roughly the same, thereby ensuring the stability of the crack tearing range and reducing the probability of uncontrollable cracks.

[0139] According to some embodiments of the present application, the first extension section 201b and the second extension section 201c are both straight segments, and the angle between the extension line of the first extension section 201b and the central axis 202 is the same as the angle between the extension line of the second extension section 201c and the central axis 202. As a result, the cracks guided by the first extension section 201b and the cracks guided by the second extension section 201c can intersect on the central axis 202, thereby achieving partial opening of the housing 21.

[0140] According to some embodiments of the present application, the length of the first extension section 201b is shorter than the length of the second extension section 201c. After the crack is guided by the first extension section 201b, it will continue to tear the outer shell 21. Similarly, after the crack is guided by the second extension section 201c, it will continue to tear the outer shell 21. Because the length of the first extension section 201b is shorter than the length of the second extension section 201c, the two cracks are no longer guided by the first extension section 201b and the second extension section 201c. The subsequent valve opening area of ​​the outer shell 21 after the crack is guided by the first extension section 201b is larger than the subsequent valve opening area of ​​the outer shell 21 after the crack is guided by the second extension section 201c. Therefore, after thermal runaway of the battery cell 20 occurs, the high-pressure gas in the outer shell 21 can be quickly discharged.

[0141] According to some embodiments of the present application, the first extension section 201b and the second extension section 201c are both straight segments, and the angle between the extension line of the first extension section 201b and the central axis 202 is different from the angle between the extension line of the second extension section 201c and the central axis 202. As a result, the subsequent valve opening area of ​​the outer shell 21 after the crack passes through the first extension section 201b is different from the subsequent valve opening area of ​​the outer shell 21 after the crack passes through the second extension section 201c. At least one of the subsequent valve opening areas of the outer shell 21 after the crack passes through the first extension section 201b and the subsequent valve opening area of ​​the outer shell 21 after the crack passes through the second extension section 201c is larger. Therefore, after thermal runaway of the battery cell 20 occurs, the high-pressure gas in the outer shell 21 can be quickly discharged.

[0142] In some embodiments of the present application, as shown in FIG4 , the central angle of the arc segment 201 a is α, satisfying the following: 180°≤α<360°. For example, the central angle can be 180°, 200°, 220°, 240°, 260°, 280°, 300°, 320°, 340°, or 350°.

[0143] The present application does not limit the specific value of the central angle of the arc segment 201a, as long as the central angle of the arc segment 201a is within the above range.

[0144] When α ≥ 180°, the area enclosed by the arc segment 201a is sufficient, so that when thermal runaway occurs in the battery cell 20, the crack along the arc segment 201a tears the outer shell 21. The crack on the arc segment 201a allows the high-pressure gas in the outer shell 21 to be quickly discharged. When α < 360°, the pressure relief notch 201 is an unclosed annular structure with an opening. The crack can tear the outer shell along the direction of the opening, making the tearing direction and tearing range of the crack controllable, thereby achieving a local valve opening on the outer shell 21. When 180° ≤ α < 360°, the crack range along the arc segment 201a is sufficient, and the high-pressure gas in the outer shell 21 can be quickly discharged. At the same time, the opening on the pressure relief notch 201 can guide the tearing direction and tearing range of the crack, achieving a local valve opening on the outer shell 21.

[0145] Since the central angle of the arc segment 201a meets the above range, the range of the pressure relief notch 201 is sufficient and can be opened when the pressure in the shell 21 meets the preset conditions. At the same time, the circular pressure relief notch 201 will not extend irregularly after being torn.

[0146] In addition, the tangents at both ends of the arc segment 201a in the length direction can also be parallel or intersecting, so that the arc segment 201a itself can also guide the cracks at the first end and the cracks at the second end to extend toward each other, and the extension directions of the cracks on both sides are in a convergent state, so that the tearing direction and tearing range of the cracks can be controlled.

[0147] In some embodiments of the present application, 210°≤α≤330°. For example, the central angle α of the arc segment 201a can be 210°, 240°, 245°, 250°, 255°, 260°, 265°, 270°, 275°, 280°, 285°, 290°, 295°, 300°, or 330°.

[0148] When α ≥ 210°, the area enclosed by the arc segment 201a is further increased. Thus, when thermal runaway occurs in the battery cell 20, the crack tears the outer shell 21 along the arc segment 201a. The tearing range of the crack allows the high-pressure gas within the outer shell 21 to be discharged more quickly. When α ≤ 330°, the pressure relief notch 201 is an unclosed annular structure with an opening and a larger opening range. Thus, the crack can tear the outer shell along the direction of the opening. Not only is the tearing direction and tearing range of the crack controllable, but the tearing range is also larger, allowing the high-pressure gas within the outer shell 21 to be discharged more quickly. When 210° ≤ α ≤ 330°, the discharge rate of the high-pressure gas within the outer shell 21 can be further increased. At the same time, the opening size of the arc segment 201a is larger, guiding the crack to tear over a larger range within the outer shell 21. The opening not only guides the tearing direction and tearing range of the crack, but also further increases the discharge rate of the high-pressure gas within the outer shell 21.

[0149] Since the central angle of the arc segment 201a satisfies the above range, the range of the pressure relief notch 201 is sufficient and can be opened when the pressure in the shell 21 meets the preset conditions. At the same time, the tangents of the arc segment 201a at both ends in the length direction can also intersect, so that the arc segment 201a itself can also guide the crack at the first end and the crack at the second end to extend toward each other, and the extension direction of the cracks on both sides is in a convergent state, so that the extension direction of the crack and the tearing range are controllable.

[0150] In some embodiments of the present application, the first extension segment 201b can be tangent to the arc segment 201a. In other words, the first extension segment 201b coincides with the tangent line of the first end. As a result, the crack on the arc segment 201a can smoothly extend and tear along the tangent line at the first end of the arc segment 201a, reducing obstacles to the crack tearing process, making the crack tearing smoother and more controllable, and reducing stress concentration during the tearing process.

[0151] It is understandable that the first extension segment 201b can be an arc segment or a straight line segment. This application does not limit the segment type of the first extension segment 201b, as long as the first extension segment 201b is tangent to the arc segment 201a.

[0152] In some embodiments of the present application, as shown in FIG5 , the second extension segment 201c can be tangent to the arc segment 201a. That is, the second extension segment 201c coincides with the tangent line at the second end. As a result, the crack in the arc segment 201a can smoothly extend and tear along the tangent line at the second end of the arc segment 201a, reducing obstacles to the crack tearing process, making the crack tearing smoother and more controllable, and reducing stress concentration during the tearing process.

[0153] It is understandable that the second extension segment 201c can be an arc segment or a straight line segment. This application does not limit the segment type of the second extension segment 201c, as long as the second extension segment 201c is tangent to the arc segment 201a.

[0154] As shown in FIG8 , the first extension segment 201 b is an arc segment and can be tangent to the arc segment 201 a , and the second extension segment 201 c is an arc segment and can be tangent to the arc segment 201 a .

[0155] According to some embodiments of the present application, as shown in FIG5 , the first extension segment 201b is a straight segment. Constructing the first extension segment 201b as a straight segment can, on the one hand, make the processing of the first extension segment 201b easier, and on the other hand, make the tearing process of the crack on the straight segment smoother. In other words, the straight segment can better guide the crack to tear in a predetermined direction, thereby making the tearing direction and tearing range of the crack more controllable.

[0156] According to some embodiments of the present application, the second extension segment 201c is a straight segment. Constructing the second extension segment 201c as a straight segment can, on the one hand, make the processing of the second extension segment 201c easier, and on the other hand, make the tearing process of the crack on the straight segment smoother. In other words, the straight segment can better guide the crack to tear in a predetermined direction, thereby making the tearing direction and tearing range of the crack more controllable.

[0157] In some embodiments of the present application, as shown in FIG4 , the radius of the arc segment 201 a is R, satisfying: 1 mm ≤ R ≤ 20 mm.

[0158] For example, the radius of the arc segment 201a can be 1 mm, 3 mm, 5 mm, 7 mm, 9 mm, 11 mm, 13 mm, 15 mm, 17 mm, 19 mm, or 20 mm.

[0159] The present application does not limit the specific value of the radius of the arc segment 201a. As long as the radius of the arc segment 201a is within the above range, it is within the protection scope of the present application.

[0160] When R ≥ 1mm, the crack along the arc segment 201 can meet the pressure relief requirements of the battery cell 20 in the event of thermal runaway. When R ≤ 20mm, the arc segment 201 is not too large, thereby ensuring that the overall structural strength of the housing 21 meets the requirements. When 1mm ≤ R ≤ 20mm, the pressure relief requirements of the battery cell 20 in the event of thermal runaway are met, while the pressure relief notch 201 is not too large, and the overall structural strength of the housing 21 meets the requirements.

[0161] In some embodiments of the present application, as shown in FIG4 , the length of the straight line segment is L1, which satisfies the following: 0<L1≤20mm. For example, the length of the straight line segment can be 1mm, 3mm, 5mm, 7mm, 9mm, 11mm, 13mm, 15mm, 17mm, 19mm, or 20mm.

[0162] It should be noted that the length of the straight segment is the length when the first extension segment 201b is constructed as a straight line, or the length when the second extension segment 201c is constructed as a straight line.

[0163] This application does not limit the length of the straight line segment. As long as the radius of the straight line segment is within the above range, it is within the protection scope of this application.

[0164] When L1>0, the crack tearing along the straight line segment can meet the pressure relief requirements of the battery cell 20 in the event of thermal runaway. When L1≤20mm, the straight line segment is not too large, thereby ensuring that the overall structural strength of the housing 21 meets the requirements. When 0<L1≤20mm, the pressure relief requirements of the battery cell 20 in the event of thermal runaway are met, and the range of the pressure relief notch 201 is not too large to affect the overall structural strength of the housing 21.

[0165] According to some embodiments of the present application, 3mm≤R≤10mm, 1mm≤L1≤10mm.

[0166] For example, the radius of the arc segment 201a can be 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm.

[0167] The present application does not limit the specific value of the radius of the arc segment 201a. As long as the radius of the arc segment 201a is within the above range, it is within the protection scope of the present application.

[0168] When R ≥ 3mm, the crack along the arc segment 201 can further meet the pressure relief requirements of the battery cell 20 in the event of thermal runaway. When R ≤ 10mm, the arc segment 201 is not too large, thereby further ensuring that the overall structural strength of the housing 21 meets the requirements. When 3mm ≤ R ≤ 10mm, the pressure relief requirements of the battery cell 20 in the event of thermal runaway can be further met, while also ensuring that the range of the pressure relief notch 201 is not too large, further ensuring that the overall structural strength of the housing 21 meets the requirements.

[0169] For example, the length of the straight segment can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm.

[0170] It should be noted that the length of the straight segment is the length when the first extension segment 201b is constructed as a straight line, or the length when the second extension segment 201c is constructed as a straight line.

[0171] This application does not limit the length of the straight line segment. As long as the radius of the straight line segment is within the above range, it is within the protection scope of this application.

[0172] When L1 ≥ 1mm, the crack tearing along the straight line segment can further meet the pressure relief requirements of the battery cell 20 in the event of thermal runaway. When L1 ≤ 10mm, the straight line segment is not too large, thereby further ensuring that the overall structural strength of the housing 21 meets the requirements. When 1mm ≤ L1 ≤ 20mm, the pressure relief requirements of the battery cell 20 in the event of thermal runaway can be further met, and the range of the pressure relief notch 201 can be kept within a certain range, further ensuring that the overall structural strength of the housing 21 meets the requirements.

[0173] In some embodiments of the present application, 0<L1 / R≤2. For example, L1 / R can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0.

[0174] This application does not limit the specific value of L1 / R. As long as L1 / R is within the above range, it is within the protection scope of this application.

[0175] L1 / R represents the degree to which the straight line segment extends relative to the radius of the arc segment. The larger L1 / R is, the more the straight line segment extends compared to the radius of the arc segment. The smaller L1 / R is, the less the straight line segment extends compared to the radius of the arc segment.

[0176] When L1 / R>0, a straight line segment can extend from one end of the arc segment, guiding the crack to tear the outer shell 21. The crack tearing along the straight line segment can meet the pressure relief requirements of the battery cell 20 during thermal runaway. When L1 / R≤2, the length of the straight line segment is not too long, thereby controlling the range of the pressure relief notch 201 and ensuring that the overall structural strength of the outer shell 21 meets the requirements. When 0<L1 / R≤0.6, the straight line segment is ensured to have sufficient length to guide the tearing direction and range of the crack, while also mitigating the negative impact on the structural strength of the outer shell 21 caused by the excessive extension of the straight line segment, which results in an excessively large pressure relief notch 201.

[0177] In some embodiments of the present application, 0.1≤L1 / R≤1. For example, L1 / R can be 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.7, 0.8, 0.9, or 1.0.

[0178] When L1 / R ≥ 0.1, a straight line segment can extend from one end of the arc segment, guiding the crack to tear the outer shell 21. Once the crack tears along the straight line segment, it can further meet the pressure relief requirements of the battery cell 20 during thermal runaway. When L1 / R ≤ 1, the length of the straight line segment is not too long, thereby controlling the range of the pressure relief notch 201 and further ensuring that the overall structural strength of the outer shell 21 meets the requirements. When 0 < L1 / R ≤ 0.6, the straight line segment is ensured to have sufficient length to guide the tearing direction and range of the crack, while also further alleviating the negative impact on the structural strength of the outer shell 21 caused by the excessive extension of the straight line segment, resulting in an excessively large pressure relief notch 201.

[0179] In some embodiments of the present application, as shown in Figures 4 and 5, the end of the first extension section 201b away from the arc section 201a and the end of the second extension section 201c away from the arc section 201a are spaced apart to form an opening 203. In other words, the end of the first extension section 201b away from the arc section 201a and the end of the second extension section 201c away from the arc section 201a are not connected to each other, thereby ensuring that the pressure relief notch 201 is in an unsealed state.

[0180] Generally speaking, the orientation of the opening 203 directly affects the tearing direction of the crack. For example, if the opening 203 is toward the corner of the first wall 212a, then after the battery cell 20 thermally runs away, the high-pressure gas will tear the pressure relief notch 201, and the crack can be torn along the direction of the opening 203 toward the corner, so the tearing direction of the crack can be adjusted by adjusting the orientation of the opening 203.

[0181] In some embodiments of the present application, as shown in FIG3 , the housing 21 is flat, and the first wall 212a is the wall of the housing 21 in the thickness direction. That is, the pressure relief notch 201 in the embodiments of the present application is not provided on the small surface, but rather on the large surface of the housing 21. Consequently, the pressure relief notch 201 is not constrained by the size of the small surface and can be designed to an appropriate size as needed. Furthermore, providing the pressure relief notch 201 on the large surface can reduce the difficulty of processing the pressure relief notch 201, thereby reducing the manufacturing cost of the pressure relief notch 201.

[0182] In some embodiments of the present application, as shown in FIG6 , the pressure relief notch 201 is disposed in the corner region of the first wall 212a. By disposing the pressure relief notch 201 in the corner region of the first wall 212a, when thermal runaway occurs in the battery cell 20, cracks can tear the outer shell 21 under the guidance of the pressure relief notch 201. Since the pressure relief notch 201 is disposed in the corner region of the first wall 212a, the tearing area of ​​the cracks is also mainly concentrated in the corner region of the first wall 212a, thereby reducing the probability of the cracks damaging other areas of the first wall 212a, making it possible to recycle the outer shell 21 after thermal runaway occurs in the battery cell 20.

[0183] In some embodiments of the present application, the opening 203 on the pressure relief score 201 is oriented toward the corner of the first wall 212a. Thus, when the shell 21 is torn along the pressure relief score 201, the crack can tear along the direction of the opening 203, and the tearing direction of the crack is toward the corner of the first wall 212a, thereby reducing the probability of the crack moving toward the middle area of ​​the first wall 212a and reducing the probability of the first wall 212a being completely torn, so that the shell 21 can be recycled.

[0184] According to some embodiments of the present application, as shown in FIG. 6 , the first wall 212 a includes a first edge 204 and a second edge 205 , and the first edge 204 and the second edge 205 intersect to form a corner of the first wall 212 a .

[0185] The shortest distance between the center of the pressure relief notch 201 and the first edge 204 is L2, and the length of the second edge 205 is L, satisfying: 0<L2<L / 2;

[0186] The shortest distance between the center of the pressure relief notch 201 and the second edge 205 is W1, and the length of the first edge 204 is W, satisfying: 0<W1<W / 2.

[0187] As a result, the center of the pressure relief notch 201 is close to a corner defined by the first edge 204 and the second edge 205. Consequently, the tearing area of ​​the crack is primarily concentrated in the corner area of ​​the first wall 212a, thereby reducing the probability of the crack damaging other areas of the first wall 212a and making it possible to recycle the outer shell 21 after the battery cell 20 experiences thermal runaway.

[0188] In some embodiments of the present application, as shown in Figure 6, the shortest distance between the end of the first extension segment 201b away from the arc segment 201a and the first edge 204 is L3, and the length of the second edge 205 is L, satisfying: 0<L3<L / 2; the shortest distance between the end of the second extension segment 201c away from the arc segment 201a and the second edge 205 is W2, and the length of the first edge 204 is W, satisfying: 0<W2<W / 2.

[0189] The end of the first extension segment 201b away from the arc segment 201a is spaced apart from the end of the second extension segment 201c away from the arc segment 201a to form an opening 203. Since the shortest distance between the end of the first extension segment 201b away from the arc segment 201a and the first edge 204 and the length of the second edge 205 meet the above conditions, the shortest distance between the end of the second extension segment 201c away from the arc segment 201a and the second edge 205 and the length of the first edge 204 meet the above conditions, the opening 203 faces the corner defined by the first edge 204 and the second edge 205.

[0190] Thus, when the crack tears the shell 21 along the pressure relief notch 201, it can tear along the direction of the opening 203, that is, the tearing direction of the crack is toward the corner of the first wall 212a, thereby reducing the probability of the crack moving toward the middle area of ​​the first wall 212a, reducing the probability of the first wall 212a being completely torn, and allowing the shell 21 to be recycled.

[0191] In related art, the pressure relief notch is annular and located in the center of the first wall. Because it lacks an opening, cracks in the event of thermal runaway in a battery cell are not directed to the intended location but instead extend erratically away from the center. Multiple cracks diverge from the center, completely destroying a large portion of the first wall.

[0192] In some embodiments of the present application, as shown in Figure 4, the pressure relief notch 201 is disposed in the central region of the first wall 212a. It is understood that the center of the pressure relief notch 201 can be disposed in the central region of the first wall 212a, or the area enclosed by the pressure relief notch 201 can be located in the central region of the first wall 212a.

[0193] The pressure relief notch 201 is arranged in the central area of ​​the first wall 212a. At the same time, since the pressure relief notch 201 has an opening 203, when the battery cell 20 suffers thermal runaway, the crack will extend along the pressure relief notch 201 and along the area toward which the opening 203 faces. In this way, the crack will not tear irregularly and will not destroy most areas of the first wall 212a, but can be guided to a preset area.

[0194] In some embodiments of the present application, as shown in FIG7 , the thickness of the first wall 212a is T, satisfying the following: 0.03 mm ≤ T ≤ 0.6 mm. For example, the thickness of the first wall 212a provided with the pressure relief notch 201 may be 0.03 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, or 0.6 mm. This application does not limit the specific value of the thickness of the first wall 212a; as long as the thickness of the first wall 212a meets the above range, it is within the scope of protection of this application.

[0195] When T ≥ 0.03 mm, the first wall 212 a can be guaranteed to have sufficient structural strength, facilitating subsequent laser etching of the pressure relief notch 201 thereon. When T ≤ 0.6 mm, the first wall 212 a can be made sufficiently thin, thereby increasing the energy density of the battery cell 20 in the thickness direction of the first wall 212 a. When 0.03 mm ≤ T ≤ 0.6 mm, the first wall 212 a can be guaranteed to be sufficiently thin, thereby increasing the energy density of the battery cell 20 in the thickness direction of the first wall 212 a, while also providing the first wall 212 a with sufficient structural strength, facilitating subsequent laser etching of the pressure relief notch 201 thereon.

[0196] In some embodiments of the present application, as shown in FIG7 , the first wall 212a is provided with a pressure relief notch 201, and the thickness of the first wall 212a is T, satisfying the following: 0.05 mm ≤ T ≤ 0.2 mm. For example, the thickness of the first wall 212a provided with the pressure relief notch 201 can be 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, or 0.2 mm. This application does not limit the specific value of the thickness of the first wall 212a. As long as the thickness of the first wall 212a meets the above range, it is within the scope of protection of this application.

[0197] When T ≥ 0.05 mm, the first wall 212 a can be further guaranteed to have sufficient structural strength, facilitating subsequent laser etching of the pressure relief notch 201 thereon. When T ≤ 0.2 mm, the first wall 212 a can be made sufficiently thin, further improving the energy density of the battery cell 20 in the thickness direction of the first wall 212 a. When 0.03 mm ≤ T ≤ 0.6 mm, the first wall 212 a can be made sufficiently thin, further improving the energy density of the battery cell 20 in the thickness direction of the first wall 212 a, and can also be made sufficiently structurally strong, facilitating subsequent laser etching of the pressure relief notch 201 thereon.

[0198] In some embodiments of the present application, the housing 21 includes a shell 211 and a cover plate 212, the shell 211 includes a bottom wall 211a and a peripheral side wall 211b, one end of the peripheral side wall 211b is connected to the outer periphery of the bottom wall 211a, and the other end of the peripheral side wall 211b forms a first opening, and the cover plate 212 closes the first opening, wherein the first wall 212a is the cover plate 212 or the bottom wall 211a.

[0199] In other words, the outer shell 21 is formed from two separate components: a shell 211 and a cover plate 212. The shell 211 and cover plate 212 can be metal components and can be fixed together by welding. The first wall 212a is the cover plate 212 or the bottom wall 211a, so the pressure relief notch 201 is provided on the cover plate 212 or the bottom wall 211a. For example, if the battery cell 20 is flat and the cover plate 212 and the bottom wall 211a are opposite in the thickness direction, the pressure relief notch 201 is provided on the large surface of the outer shell 21.

[0200] In some embodiments of the present application, the housing 21 is made of stainless steel, and the pressure relief notch 201 can be formed by laser etching. Of course, the pressure relief notch 201 can also be formed by stamping, and the present application does not limit the forming method of the pressure relief notch 201.

[0201] In some embodiments of the present application, the cross-sectional shape of the pressure relief notch 201 may be a trapezoid, with the longer of the two parallel sides of the trapezoid being located at the opening 203 of the groove of the pressure relief notch 201, the shorter of the two parallel sides having a length of 0.05 mm to 1.0 mm, and the bottom angle of the trapezoid (the angle between the bottom wall and the surrounding wall of the trapezoidal groove) being 30° to 60°.

[0202] The cross section of the pressure relief notch 201 is a trapezoid, which has better consistency and less stress concentration. Of course, the cross section of the pressure relief notch 201 can also be a triangle, an arc or a rectangle.

[0203] The following briefly describes the battery of the embodiment of the present application.

[0204] The battery according to the embodiment of the present application includes the battery cell 20 of the above-mentioned embodiment. Since the battery according to the embodiment of the present application is provided with the above-mentioned battery cell 20, the pressure relief notch 201 can be torn when the battery cell 20 thermally runs away. The size and tearing direction of the torn part on the outer shell 21 can be controlled, thereby realizing local valve opening and reducing the probability of large-scale tearing of the outer shell 21.

[0205] The following briefly describes the electrical equipment in the embodiment of the present application.

[0206] The electrical equipment according to the embodiment of the present application includes the above-mentioned battery. Since the electrical equipment according to the embodiment of the present application is provided with the above-mentioned battery, the safety of the electrical equipment is improved, and the negative impact of the battery cell 20 on the electrical equipment when thermal runaway occurs is reduced.

[0207] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: a housing including a first wall; A pressure relief notch is arranged on the first wall, and the pressure relief notch includes an arc segment and a first extension segment. The arc segment has a first end, and the first extension segment is connected to the first end and extends from the first end toward a direction close to the center axis of the arc segment.

2. The battery cell according to claim 1, characterized in that: The pressure relief notch further includes a second extension segment, the arc segment has a second end, the second extension segment is connected to the second end and extends from the second end toward the direction close to the central axis.

3. The battery cell according to claim 2, characterized in that: The first extension segment and the second extension segment are symmetrical about the central axis.

4. The battery cell according to claim 2 or 3, characterized in that: The length of the first extension section is the same as the length of the second extension section.

5. The battery cell according to any one of claims 2 to 4, characterized in that: The first extension segment and the second extension segment are both straight line segments, and the angle between the extension line of the first extension segment and the central axis is the same as the angle between the extension line of the second extension segment and the central axis.

6. The battery cell according to any one of claims 2 to 5, characterized in that: The length of the first elongated section is smaller than the length of the second elongated section.

7. The battery cell according to any one of claims 2 to 6, characterized in that: The first extension segment and the second extension segment are both straight line segments, and the included angle between the extension line of the first extension segment and the central axis is different from the included angle between the extension line of the second extension segment and the central axis.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The center angle of the arc segment is α, which satisfies: 180°≤α<360°.

9. The battery cell according to claim 8, characterized in that: 210°≤α≤330°。 10. The battery cell according to any one of claims 1 to 9, characterized in that: The first extension segment is tangent to the circular arc segment; and / or the second extension segment is tangent to the circular arc segment.

11. The battery cell according to any one of claims 1 to 10, characterized in that: The first extension segment is a straight line segment; and / or the second extension segment is a straight line segment.

12. The battery cell according to claim 11, characterized in that: The radius of the arc segment is R, which satisfies: 1mm≤R≤20mm; The length of the straight line segment is L1, which satisfies: 0<L1≤20mm.

13. The battery cell according to claim 12, characterized in that: 3mm≤R≤10mm, 1mm≤L1≤10mm.

14. The battery cell according to any one of claims 11 to 13, characterized in that: Satisfies: 0<L1 / R≤2.

15. The battery cell according to claim 14, characterized in that: Satisfies: 0.1≤L1 / R≤1.

16. The battery cell according to any one of claims 1 to 15, characterized in that: One end of the first extension segment away from the arc segment and one end of the second extension segment away from the arc segment are spaced apart to form an opening.

17. The battery cell according to claim 16, characterized in that: The shell is flat, and the first wall is a wall of the shell in a thickness direction.

18. The battery cell according to claim 17, characterized in that: The pressure relief notch is disposed at a corner area of ​​the first wall, and the opening faces the corner of the first wall.

19. The battery cell according to claim 17 or 18, characterized in that: The first wall comprises a first edge and a second edge, the first edge and the second edge intersecting to form a corner of the first wall; The shortest distance between the center of the pressure relief notch and the first edge is L2, and the length of the second edge is L, satisfying: 0<L2<L / 2; The shortest distance between the center of the pressure relief notch and the second edge is W1, and the length of the first edge is W, satisfying: 0<W1<W / 2.

20. The battery cell according to any one of claims 17 to 19, characterized in that: The shortest distance between the end of the first extension segment away from the arc segment and the first edge is L3, and the length of the second edge is L, satisfying: 0<L3<L / 2; The shortest distance between the end of the second extension segment away from the arc segment and the second edge is W2. The length of is W, satisfying: 0<W2<W / 2.

21. The battery cell according to any one of claims 17 to 20, characterized in that: The pressure relief notch is disposed in a central area of ​​the first wall.

22. The battery cell according to any one of claims 1 to 21, characterized in that: The wall thickness of the first wall is T, which satisfies: 0.03 mm ≤ T ≤ 0.6 mm.

23. The battery cell according to claim 22, characterized in that: The T satisfies: 0.05mm≤T≤0.2mm.

24. The battery cell according to any one of claims 1 to 23, characterized in that: The housing comprises a shell and a cover plate, the shell comprises a bottom wall and a peripheral side wall, one end of the peripheral side wall is connected to the outer peripheral edge of the bottom wall, the other end of the peripheral side wall forms a first opening, and the cover plate closes the first opening; The first wall is the cover plate or the bottom wall.

25. A battery, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 24.

26. An electrical equipment, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 24 or a battery according to claim 25, wherein the battery cell or the battery is used to provide electrical energy.

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