Battery cell, battery and electric device

Abstract

Provided in the present application are a battery cell, a battery and an electric device. The battery cell comprises a casing and a protective member, wherein the casing comprises a first wall portion, the first wall portion having a first surface, the first surface being provided with pressure relief grooves, and the first wall portion being configured to be capable of splitting along the pressure relief grooves when the battery cell undergoes pressure relief. The protective member is arranged on the first surface, and covers the pressure relief grooves. In the direction of thickness of the first wall portion, the protective member and openings of the pressure relief grooves are spaced apart from each other. The protective member is provided on the first wall portion of the battery cell. The protective member can resist external force interference and protect the pressure relief grooves, and can also limit the deformation of the first wall portion and reduce the risk of the first wall portion splitting in advance along the pressure relief grooves due to the pressure relief grooves suffering from a change of pressure inside the battery cell. By means of spacing the protective member apart from the openings of the pressure relief grooves, when the battery cell undergoes pressure relief, the protective member is not prone to preventing the first wall portion from splitting along the pressure relief grooves, such that when the battery cell undergoes pressure relief, the pressure relief grooves can quickly split to relieve pressure, thereby facilitating an improvement in the reliability of the battery cell.

Description

Battery cells, batteries and electrical equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application entitled “Battery Cell, Battery and Electrical Equipment” filed on March 5, 2024 (application number: 202420428211.4), the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of batteries, and more specifically, to a battery cell, a battery, and an electrical device. Background Art

[0004] Batteries are widely used in new energy applications, such as electric vehicles and new energy vehicles. These have become a new trend in the automotive industry. The development of battery technology requires consideration of multiple design factors, including performance parameters such as battery life, energy density, discharge capacity, and charge / discharge rate. Furthermore, battery reliability must be considered. However, current battery reliability is relatively poor.

[0005] Summary of the Invention

[0006] The purpose of the embodiments of the present application is to provide a battery cell, a battery, and an electrical device, which are intended to improve the problem of poor reliability of batteries in related technologies.

[0007] In a first aspect, an embodiment of the present application provides a battery cell, comprising an outer shell and a protective member, wherein the outer shell comprises a first wall portion, the first wall portion having a first surface, the first surface being provided with a pressure relief groove, and the first wall portion being configured to be able to split along the pressure relief groove when the battery cell is depressurized; the protective member is provided on the first surface, the protective member shields the pressure relief groove, and a gap is provided between the protective member and the notch of the pressure relief groove along the thickness direction of the first wall portion.

[0008] In the above technical solution, the first wall of the battery cell is provided with a protective member. The protective member has a certain strength, can resist external interference, protect the pressure relief groove, and also limit the deformation of the first wall, reducing the risk of the pressure relief groove being prematurely cracked along the pressure relief groove due to pressure changes within the battery cell. In addition, by providing a gap between the protective member and the notch of the pressure relief groove, the protective member is less likely to prevent the first wall from cracking along the pressure relief groove when the battery cell releases pressure. This allows the pressure relief groove to quickly crack and release pressure when the battery cell releases pressure, which is beneficial to improving the reliability of the battery cell.

[0009] As an optional technical solution of an embodiment of the present application, a protrusion is provided on the first surface, and the protrusion contacts the protective member so that a gap is set between the protective member and the notch of the pressure relief groove.

[0010] In the above technical solution, by providing a protrusion on the first surface, the protective member can be attached to the first surface and the protrusion, not only protecting the pressure relief groove but also limiting deformation of the first wall, reducing the risk of premature cracking of the first wall along the pressure relief groove due to pressure changes within the battery cell. Because the protrusion protrudes from the first surface, when the protective member is provided on the first surface and the protrusion, the protective member can straddle the notch of the pressure relief groove, ensuring a gap between the protective member and the notch.

[0011] As an optional technical solution of an embodiment of the present application, the pressure relief groove defines a predetermined pressure relief area, and the predetermined pressure relief area is configured to split with the pressure relief groove as the boundary when the battery cell is depressurized, and the protrusion is located in the predetermined pressure relief area.

[0012] In the above technical solution, the pressure relief groove defines a predetermined pressure relief area, and the protrusion is arranged in the predetermined pressure relief area. It can also be understood that the pressure relief groove is arranged around the outside of the protrusion. In this way, when the protective member contacts the protrusion and the first surface, it can better cover the pressure relief groove and be set with a gap between it and the notch of the pressure relief groove.

[0013] As an optional technical solution of the embodiment of the present application, the first surface is the surface of the first wall portion facing away from the interior of the shell.

[0014] In the above technical solution, the first surface is the outer surface of the first wall, which, on the one hand, makes it easier to install the protective member. On the other hand, when the gas in the battery cell acts on the first wall, it does not need to bypass the protective member, thereby facilitating rapid pressure relief of the battery cell.

[0015] As an optional technical solution of an embodiment of the present application, the protective member includes an insulating layer and a first adhesive layer, the first adhesive layer is arranged on one side of the insulating layer, and the first adhesive layer connects the first wall portion and the insulating layer.

[0016] In the above technical solution, the protective member includes an insulating layer that can provide insulation and isolation, reducing the risk of short circuits caused by contact between other components and the first wall. The protective member also includes a first adhesive layer that is sticky and can quickly adhere the protective member to the first wall.

[0017] As an optional technical solution of an embodiment of the present application, the protective member includes a second adhesive layer and a plurality of the insulating layers, the plurality of the insulating layers are stacked, and two adjacent insulating layers are connected by the second adhesive layer.

[0018] In the above technical solution, multiple insulating layers are provided, allowing them to be stacked and stacked, providing greater strength and improved insulation. Adjacent insulating layers are connected by a second adhesive layer, which imparts greater toughness to the protective member and allows it to adhere more closely to the housing, thereby better protecting the pressure relief groove and limiting deformation of the first wall. This reduces the risk of premature cracking of the first wall along the pressure relief groove due to pressure changes within the battery cells.

[0019] As an optional technical solution of the embodiment of the present application, the material of the insulating layer is polyethylene terephthalate or polyimide.

[0020] In the above technical solution, polyethylene terephthalate or polyimide is used as the material to make the insulation layer, which not only has good insulation performance but also has low cost.

[0021] As an optional technical solution of the embodiment of the present application, the protective member is configured to be destroyed when the battery cell is depressurized.

[0022] In the above technical solution, when the battery cell releases pressure, the protective member can be destroyed, thereby allowing the first wall portion to crack along the pressure relief groove, opening a larger opening for pressure relief, which is beneficial to improving the timeliness of the battery cell pressure relief and thus improving the reliability of the battery cell.

[0023] As an optional technical solution of the embodiment of the present application, the protective member is an insulating film.

[0024] In the above technical solution, when the protective member is an insulating film, it can insulate the first wall from other components, reducing the risk of short circuits caused by contact between the first wall and other components. In addition, the insulating film is relatively thin and easily damaged when the battery cell is depressurized, thereby facilitating the first wall to open a larger opening to release pressure.

[0025] As an optional technical solution of the embodiment of the present application, the thickness of the protective member is H, which satisfies: 0.02mm≤H≤0.14mm.

[0026] In the above technical solution, when H ≥ 0.02 mm, the thickness of the protective member is relatively large, the protective member has high strength, and provides better protection for the pressure relief groove. When H ≤ 0.14 mm, the thickness of the protective member is not too large, and the strength is not too high. When the battery cell releases pressure, the protective member can be destroyed, thereby facilitating the first wall portion to open a larger opening to release pressure.

[0027] As an optional technical solution of the embodiment of the present application, 0.055mm≤H≤0.11mm.

[0028] In the above technical solution, when H ≥ 0.055 mm, the thickness of the protective member is greater, the protective member has higher strength, and provides better protection for the pressure relief groove. When H ≤ 0.11 mm, the thickness of the protective member is not too large, and the strength is not too high. When the battery cell releases pressure, the protective member can be destroyed, making it easier for the first wall to open a larger opening to release pressure, thereby facilitating rapid pressure relief for the battery cell.

[0029] As an optional technical solution of an embodiment of the present application, the pressure relief groove extends along a non-closed track.

[0030] In the above technical solution, the pressure relief groove is set to extend along a non-closed trajectory. When the battery cell releases pressure, the predetermined pressure relief area will open outward in a flipped form. After opening, the predetermined pressure relief area is still partially connected to other parts of the first wall except the predetermined pressure relief area. The predetermined pressure relief area will not detach and fly out due to the rapid discharge of emissions.

[0031] As an optional technical solution of an embodiment of the present application, the pressure relief groove includes a first groove section, a second groove section and a third groove section, the first groove section is arranged opposite to the third groove section, and the second groove section connects the first groove section and the third groove section.

[0032] In the above technical solution, the pressure relief groove includes a first groove section, a second groove section and a third groove section. The second groove section connects the first groove section and the third groove section, so that the first wall portion can be cracked along the first groove section, the second groove section and the third groove section when the battery cell is depressurized, so as to open the predetermined pressure relief area to release the internal pressure of the battery cell. The connection position between the first groove section and the second groove section and the connection position between the first groove section and the third groove section are weaker, easier to crack and open the predetermined pressure relief area for pressure relief, and can further improve the pressure relief area and pressure relief rate of the battery cell.

[0033] As an optional technical solution of an embodiment of the present application, the pressure relief groove extends along a closed track.

[0034] In the above technical solution, by extending the pressure relief groove along a closed track, when the battery cell releases pressure, the predetermined pressure relief area will be completely separated from other parts of the first wall except the predetermined pressure relief area, thereby having a larger pressure relief area.

[0035] As an optional technical solution of an embodiment of the present application, the housing includes a shell and an end cover, the shell has an opening; the end cover is arranged on the shell and closes the opening; wherein at least one wall portion in the shell is the first wall portion.

[0036] In the above technical solution, when the shell includes a first wall portion, the pressure relief groove is provided on one wall portion of the shell, and the ejected fluid medium is not likely to act on other electrical connection structures on the end cover, which is beneficial to reducing the risk of short circuit of the battery cell.

[0037] As an optional technical solution of an embodiment of the present application, the shell is a cylindrical structure, and the wall portion of the shell arranged around the center line thereof is the first wall portion.

[0038] In the above technical solution, the peripheral wall of the cylindrical structure is the first wall portion, and the peripheral wall has a large area, which is convenient for setting the pressure relief groove. In addition, the protective member can be covered on the outer side of the peripheral wall to better protect the pressure relief groove.

[0039] In a second aspect, an embodiment of the present application further provides a battery, which includes the above-mentioned battery cell.

[0040] In a third aspect, an embodiment of the present application further provides an electrical device, which includes the above-mentioned battery cell. 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 structural diagram of a vehicle provided in some embodiments of the present application;

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

[0044] FIG3 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0045] FIG4 is an exploded view of a battery cell provided in some embodiments of the present application;

[0046] FIG5 is a schematic top view of a battery cell provided in some embodiments of the present application;

[0047] FIG6 is a cross-sectional view taken along line AA in FIG5 ;

[0048] FIG7 is an enlarged view of position B in FIG6 ;

[0049] FIG8 is a cross-sectional view of a protective member provided in some embodiments of the present application.

[0050] Icons: 1000-vehicle; 100-battery; 10-casing; 11-first casing body; 12-second casing body; 20-battery cell; 21-housing; 211-shell; 212-end cover; 213-first wall; 2131-first surface; 2132-pressure relief groove; 2132a-first groove section; 2132b-second groove section; 2132c-third groove section; 2133-predetermined pressure relief area; 22-protective member; 221-insulating layer; 222-first adhesive layer; 223-second adhesive layer; 23-electrode assembly; 24-electrode terminal; 25-protrusion; 200-controller; 300-motor. DETAILED DESCRIPTION

[0051] 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 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.

[0052] 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 for the purpose of describing specific embodiments only 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0057] The term "plurality" used in this application refers to two or more (including two).

[0058] 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.

[0059] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.).

[0064] 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 traditional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include but are not limited to at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include but are not limited to lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and at least one of its modified compounds, etc.

[0065] In some embodiments, a positive electrode may utilize a metal foam. The metal foam may include nickel foam, copper foam, aluminum foam, alloy foam, or the like. When a metal foam is used as the positive electrode, the surface of the metal foam may or may not include a positive electrode active material. For example, a lithium source material, potassium metal, or sodium metal may be filled or / and deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0066] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0067] As an example, the negative electrode current collector may be a metal foil, a metal foam, or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, or titanium, etc. may be used. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, etc. 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 (copper, copper 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 negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0069] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0070] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells 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.

[0071] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0072] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0073] In some embodiments, the separator is a separator membrane. There are many types of separator membranes, and any known separator membrane with a porous structure having good chemical stability and mechanical stability can be selected.

[0074] As an example, the separator can be made of at least one of fiberglass, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film. In the case of a multi-layer composite film, the materials of each layer can be the same or different. 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] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0087] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0088] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0089] As an example, a plurality of separators may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0090] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0091] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0092] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0093] 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.

[0094] As an example, the battery cells may be cylindrical, prismatic, soft-pack or other shaped battery cells. Prismatic battery cells include but are not limited to square-shell, blade-shaped, and polygonal batteries, such as hexagonal batteries.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0100] Batteries are widely used in new energy applications, such as electric vehicles and new energy vehicles. These have become a new trend in the automotive industry. The development of battery technology requires consideration of multiple design factors, including performance parameters such as battery life, energy density, discharge capacity, and charge / discharge rate. Furthermore, battery reliability must be considered. However, current battery reliability is relatively poor.

[0101] For battery cells, in order to improve the reliability of battery cells, the existing technology is to weld a pressure relief mechanism on the battery cells. A weak portion is provided on the pressure relief mechanism, and the weak portion defines a pressure relief portion. When the internal pressure of the battery cell reaches the detonation pressure, the weak portion cracks and the pressure relief portion opens to release the pressure inside the battery cell, thereby reducing the risk of battery cell explosion or fire.

[0102] However, during the use of the battery cell, the weak part is easily opened prematurely by external force, or the pressure relief mechanism is repeatedly deformed by the internal air pressure of the battery cell, causing the weak part to fatigue and fail, opening prematurely, resulting in the failure to achieve normal pressure relief function.

[0103] In view of this, an embodiment of the present application provides a battery cell, comprising a housing and a protective member. The housing includes a first wall portion having a first surface provided with a pressure relief groove, and the first wall portion is configured to rupture along the pressure relief groove when pressure is released from the battery cell. A protective member is provided on the first surface, shielding the pressure relief groove. A gap is provided between the protective member and the notch of the pressure relief groove along the thickness direction of the first wall portion.

[0104] The first wall of the battery cell is provided with a protective member. This member has a certain strength to resist external interference, protect the pressure relief groove, and limit deformation of the first wall, reducing the risk of premature cracking of the first wall along the pressure relief groove due to pressure changes within the battery cell. In addition, by providing a gap between the protective member and the notch of the pressure relief groove, the protective member is less likely to prevent the first wall from cracking along the pressure relief groove during pressure relief in the battery cell. This allows the pressure relief groove to quickly crack and release pressure when the battery cell is depressurized, which helps improve the reliability of the battery cell.

[0105] The battery cells disclosed in the embodiments of this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cells and batteries disclosed in this application can be used to form the electrical device, thereby improving the reliability of the battery cells.

[0106] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, 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.

[0107] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device according to an embodiment of the present application.

[0108] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of the present application. The 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. The battery 100 can be arranged at the bottom of the vehicle 1000, or at the head of the vehicle 1000, or at the 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 or a power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0109] In some embodiments of the present application, the battery 100 can not only serve as the operating power source or usage power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0110] Please refer to FIG. 2 , which is an exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20 . The battery cell 20 is used to be accommodated in the housing 10 .

[0111] The housing 10 is used to provide assembly space for the battery cells 20 and can adopt a variety of structures. In some embodiments, the housing 10 can include a first housing body 11 and a second housing body 12. The first housing body 11 and the second housing body 12 cover each other, and the first housing body 11 and the second housing body 12 jointly define an assembly space for accommodating the battery cells 20. The second housing body 12 can be a hollow structure with one end open, and the first housing body 11 can be a plate-like structure. The first housing body 11 covers the open side of the second housing body 12, so that the first housing body 11 and the second housing body 12 jointly define the assembly space. The first housing body 11 and the second housing body 12 can also be hollow structures with one end open, and the open side of the first housing body 11 covers the open side of the second housing body 12.

[0112] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid or a cube, etc. For example, in FIG2 , the box body 10 is in the shape of a cuboid.

[0113] In the battery 100, there can be one or more battery cells 20 disposed within the housing 10. When there are multiple battery cells 20 disposed within the housing 10, the multiple battery cells 20 can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel configurations within the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure formed by the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery 100 can be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid configuration to form a battery module, which is then further connected in series, in parallel, or in a hybrid configuration to form a single structure, which is then housed within the housing 10.

[0114] In some embodiments, the battery 100 may further include other structures. For example, the battery 100 may further include a busbar component, which is used to connect the multiple battery cells 20 to achieve electrical connection between the multiple battery cells 20 .

[0115] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 can be a rectangular parallelepiped, a cylinder, a prism, or other shapes. For example, in FIG2 , the battery cell 20 is a cylindrical structure.

[0116] Please refer to Figures 3, 4, 5, 6, and 7. Figure 3 is a schematic structural diagram of a battery cell 20 provided in some embodiments of the present application. Figure 4 is an exploded view of a battery cell 20 provided in some embodiments of the present application. Figure 5 is a schematic top view of a battery cell 20 provided in some embodiments of the present application. Figure 6 is a cross-sectional view taken at position AA in Figure 5. Figure 7 is an enlarged view taken at position B in Figure 6. Embodiments of the present application provide a battery cell 20, comprising a housing 21 and a protective member 22. The housing 21 includes a first wall 213 having a first surface 2131. The first surface 2131 is provided with a pressure relief groove 2132. The first wall 213 is configured to rupture along the pressure relief groove 2132 when the battery cell 20 releases pressure. The protective member 22 is disposed on the first surface 2131 and obstructs the pressure relief groove 2132. Along the thickness direction of the first wall 213, a gap is provided between the protective member 22 and the notch of the pressure relief groove 2132.

[0117] The battery cell 20 refers to the smallest unit constituting the battery 100 .

[0118] The housing 21 includes an end cover 212 and a shell 211 . The shell 211 has an opening. The end cover 212 is connected to the shell 211 and closes the opening.

[0119] The end cap 212 refers to a component that covers the opening of the shell 211 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 212 can be adapted to the shape of the shell 211 to match the shell 211. Optionally, the end cap 212 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 212 is not easily deformed when squeezed and collided, so that the battery cell 20 can have a higher structural strength and improved safety performance. The material of the end cap 212 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose special restrictions on this. Functional components such as electrode terminals 24 can be provided on the end cap 212. The electrode terminal 24 can be used to electrically connect to the electrode assembly 23 for outputting or inputting electrical energy of the battery cell 20. In some embodiments, the battery cell 20 further includes an insulating member disposed inside the end cap 212 to isolate the electrical connection components within the housing 211 from the end cap 212 to reduce the risk of short circuits. For example, the insulating member may be made of plastic, rubber, or the like.

[0120] The housing 211 is a component that cooperates with the end cap 212 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 23, electrolyte, and other components. The housing 211 and end cap 212 can be separate components. An opening can be provided in the housing 211, and the end cap 212 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 212 and housing 211 can be integrated. Specifically, the end cap 212 and housing 211 can form a common joint surface before other components are inserted into the housing. When the interior of the housing 211 is to be enclosed, the end cap 212 is placed over the housing 211. The housing 211 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, or a hexagonal prism. Specifically, the shape of the housing 211 can be determined based on the specific shape and size of the electrode assembly 23. The housing 211 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0121] The electrode assembly 23 is a component in the battery cell 20 where the electrochemical reaction occurs. One or more electrode assemblies 23 may be contained in the housing 21. The electrode assembly 23 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is usually provided 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 23, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a tab. The positive electrode tab and the negative electrode 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 100, the positive electrode active material and the negative electrode active material react with the electrolyte.

[0122] The first wall portion 213 may be an end cap 212 of the housing 21, or a wall portion of the shell 211 of the housing 21. For example, in Figures 3 and 4, the shell 211 is a cylindrical structure with two openings. The housing 211 includes two end caps 212, which respectively cover the two openings of the shell 211. The first wall portion 213 is the shell 211.

[0123] The pressure relief groove 2132 serves to relieve pressure. When the internal pressure or temperature of the battery cell 20 reaches a predetermined value, the first wall portion 213 is able to rupture along the pressure relief groove 2132 to release the pressure within the battery cell 20. The location of the pressure relief groove 2132 can be used to determine which wall portion of the housing 21 is the first wall portion 213. For example, when the pressure relief groove 2132 is located on the end cap 212, the end cap 212 is the first wall portion 213. When the pressure relief groove 2132 is located on the bottom wall of the housing 211, the bottom wall is the first wall portion 213. When the pressure relief groove 2132 is located on the side wall of the housing 211, the side wall is the first wall portion 213.

[0124] The protective member 22 has a protective function. The protective member 22 is disposed on the first wall portion 213 and blocks the pressure relief groove 2132, thereby protecting the pressure relief groove 2132 and reducing the risk of damage to the pressure relief groove 2132 from external forces. The protective member 22 and the pressure relief groove 2132 are disposed on the same surface of the first wall portion 213. For example, the protective member 22 and the pressure relief groove 2132 can both be disposed on the surface of the first wall portion 213 facing away from the interior of the housing 21. In another example, the protective member 22 and the pressure relief groove 2132 can both be disposed on the surface of the first wall portion 213 facing the interior of the housing 21.

[0125] “Protective member 22 covers pressure relief groove 2132” means that the projection of protective member 22 along the thickness direction of first wall 213 can cover the notch of pressure relief groove 2132. Referring to FIG7 , the thickness direction of first wall 213 can be direction C as shown in the figure.

[0126] “A gap is set between the protection member 22 and the notch of the pressure relief groove 2132 along the thickness direction of the first wall portion 213 ” means that there is a distance between the protection member 22 and the notch of the pressure relief groove 2132 along the thickness direction of the first wall portion 213 .

[0127] The first wall portion 213 of the battery cell 20 is provided with a protective member 22. The protective member 22 has a certain strength to resist external interference, protect the pressure relief groove 2132, and limit deformation of the first wall portion 213, thereby reducing the risk of the first wall portion 213 prematurely cracking along the pressure relief groove 2132 due to pressure changes within the battery cell 20. In addition, by providing a gap between the protective member 22 and the notch of the pressure relief groove 2132, the protective member 22 is less likely to prevent the first wall portion 213 from cracking along the pressure relief groove 2132 during pressure relief from the battery cell 20. This allows the pressure relief groove 2132 to quickly crack and release pressure when the battery cell 20 is depressurized, thereby improving the reliability of the battery cell 20.

[0128] 3 , 4 , 5 , 6 and 7 , in some embodiments, the first surface 2131 is provided with a protrusion 25 , which contacts the protection member 22 so that a gap is set between the protection member 22 and the notch of the pressure relief groove 2132 .

[0129] The protrusion 25 protrudes from the first surface 2131 , and the protrusion 25 contacts the protection member 22 to partially lift the protection member 22 , so that a gap is set between the protection member 22 and the notch of the pressure relief groove 2132 .

[0130] Optionally, along the thickness direction of the first wall portion 213 , the protrusion 25 has a second surface farthest from the first surface 2131 , and the protective member 22 is disposed on the second surface.

[0131] By providing the protrusion 25 on the first surface 2131, the protective member 22 can be attached to the first surface 2131 and the protrusion 25, not only protecting the pressure relief groove 2132 but also limiting deformation of the first wall 213, thereby reducing the risk of premature cracking of the first wall 213 along the pressure relief groove 2132 due to pressure changes within the battery cell 20. Because the protrusion 25 protrudes from the first surface 2131, when the protective member 22 is provided on the first surface 2131 and the protrusion 25, the protective member 22 can straddle the opening of the pressure relief groove 2132, thereby ensuring a gap between the protective member 22 and the opening of the pressure relief groove 2132.

[0132] 3 , 4 , 5 , 6 , and 7 , in some embodiments, the pressure relief groove 2132 defines a predetermined pressure relief area 2133 . The predetermined pressure relief area 2133 is configured to split along the pressure relief groove 2132 when the battery cell 20 releases pressure. The protrusion 25 is located in the predetermined pressure relief area 2133 .

[0133] The predetermined pressure relief area 2133 is the area enclosed by the pressure relief groove 2132. The pressure relief groove 2132 is disposed along the edge of the predetermined pressure relief area 2133. For example, when the pressure relief groove 2132 is an annular groove, the predetermined pressure relief area 2133 is the area inside the annular groove. For another example, when the pressure relief groove 2132 is a U-shaped groove, the predetermined pressure relief area 2133 is the area enclosed by the line connecting the two ends of the U-shaped groove and the U-shaped shape.

[0134] When the battery cell 20 releases pressure, the predetermined pressure relief area 2133 is split with the pressure relief groove 2132 as a boundary. The predetermined pressure relief area 2133 can be opened to form an opening on the first wall portion 213 for discharging gas inside the battery cell 20 .

[0135] The protrusion 25 is located in the predetermined pressure relief area 2133. In some embodiments, the protrusion 25 partially protrudes from the predetermined pressure relief area 2133. In other embodiments, the predetermined pressure relief area 2133 protrudes entirely from the first surface 2131 to form the protrusion 25.

[0136] The pressure relief groove 2132 defines a predetermined pressure relief area 2133, and the protrusion 25 is arranged in the predetermined pressure relief area 2133. It can also be understood that the pressure relief groove 2132 is surrounded by the outside of the protrusion 25. In this way, when the protective member 22 contacts the protrusion 25 and the first surface 2131, it can better cover the pressure relief groove 2132 and be set with an opening gap with the pressure relief groove 2132.

[0137] 3 , 4 , 5 , 6 and 7 , in some embodiments, the first surface 2131 is a surface of the first wall portion 213 facing away from the interior of the housing 21 .

[0138] The first surface 2131 is the surface of the first wall 213 facing away from the interior of the housing 21 , that is, the first surface 2131 is the outer surface of the first wall 213 . The pressure relief groove 2132 is recessed from the first surface 2131 toward the surface of the first wall 213 facing the interior of the housing 21 .

[0139] The first surface 2131 is the outer surface of the first wall portion 213. On the one hand, it is more convenient to install the protective member 22. On the other hand, when the gas in the battery cell 20 acts on the first wall portion 213, it does not need to bypass the protective member 22, thereby facilitating rapid pressure relief of the battery cell 20.

[0140] Please refer to Figure 8, which is a cross-sectional view of a protective member 22 provided in some embodiments of the present application. In some embodiments, the protective member 22 includes an insulating layer 221 and a first adhesive layer 222, which is disposed on one side of the insulating layer 221. The first adhesive layer 222 connects the first wall portion 213 and the insulating layer 221.

[0141] The insulating layer 221 is made of an insulating material and has an insulating effect, which can achieve insulation isolation between the two components. The insulating layer 221 can be made of plastic, rubber, etc.

[0142] The first adhesive layer 222 is disposed on one side of the insulating layer 221 . The first adhesive layer 222 has adhesiveness and can adhere the insulating layer 221 to the first wall portion 213 .

[0143] The protective member 22 includes an insulating layer 221, which provides insulation and isolation, reducing the risk of short circuits caused by contact between other components and the first wall portion 213. The protective member 22 also includes a first adhesive layer 222, which is sticky and allows the protective member 22 to be quickly bonded to the first wall portion 213.

[0144] Referring to FIG. 8 , in some embodiments, the protection member 22 includes a second adhesive layer 223 and a plurality of insulating layers 221 . The plurality of insulating layers 221 are stacked, and two adjacent insulating layers 221 are connected via the second adhesive layer 223 .

[0145] The protective member 22 may include two insulating layers 221 , three insulating layers 221 , four insulating layers 221 , or more than four insulating layers 221 , wherein the plurality of insulating layers 221 are stacked.

[0146] The second adhesive layer 223 has adhesiveness and is used to bond two adjacent insulating layers 221 .

[0147] By providing multiple insulating layers 221, the stacked arrangement provides greater strength and improved insulation. Adjacent insulating layers 221 are connected by a second adhesive layer 223, giving the protective member 22 greater toughness. The protective member 22 adheres more easily to the housing 211, thereby better protecting the pressure relief groove 2132 and limiting deformation of the first wall 213. This reduces the risk of premature cracking of the first wall 213 along the pressure relief groove 2132 due to pressure changes within the battery cell 20.

[0148] In some embodiments, the insulating layer 221 is made of polyethylene terephthalate or polyimide.

[0149] Polyethylene terephthalate, also known as PET (polyethylene glycol terephthalate), has good insulation properties.

[0150] Polyimide, also referred to as PI (Polyimide), has good insulation properties.

[0151] The insulating layer 221 is made of polyethylene terephthalate or polyimide, which not only has good insulation performance but also has low cost.

[0152] In some embodiments, the protective member 22 is configured to be destroyed when the battery cell 20 is depressurized.

[0153] In some embodiments, the protective member 22 may be a thin film structure. When the battery cell 20 releases pressure, the predetermined pressure relief area 2133 opens, and the protective member 22 is torn by the predetermined pressure relief area 2133, thereby opening a larger opening for gas in the battery cell 20 to flow out.

[0154] In other embodiments, the protective member 22 may be provided with a weak portion. When the battery cell 20 is depressurized, the predetermined pressure relief area 2133 opens, and the weak portion is torn by the predetermined pressure relief area 2133, thereby creating a larger opening for gas in the battery cell 20 to flow out.

[0155] When the battery cell 20 releases pressure, the protective member 22 can be destroyed, thereby allowing the first wall portion 213 to split along the pressure relief groove 2132 , opening a larger opening for pressure relief, which is beneficial to improving the timeliness of the pressure relief of the battery cell 20 and thus improving the reliability of the battery cell 20 .

[0156] In some embodiments, the protection member 22 is an insulating film.

[0157] Optionally, the protective member 22 may be a blue film.

[0158] When the protective member 22 is an insulating film, it can insulate the first wall portion 213 from other components, reducing the risk of short circuits caused by contact between the first wall portion 213 and other components. In addition, the insulating film is relatively thin and easily damaged when the battery cell 20 releases pressure, thereby facilitating the first wall portion 213 to open a larger opening to release pressure.

[0159] Referring to FIG. 8 , in some embodiments, the thickness of the protective member 22 is H, which satisfies the following relationship: 0.02 mm ≤ H ≤ 0.14 mm.

[0160] H represents the thickness of the protective member 22 . The minimum thickness of the protective member 22 is not less than 0.02 mm, and the maximum thickness of the protective member 22 is not more than 0.14 mm.

[0161] The thickness of the protective member 22 can be: H=0.02 mm, 0.04 mm, 0.06 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.14 mm, etc.

[0162] When H ≥ 0.02 mm, the thickness of the protective member 22 is relatively large, the protective member 22 has high strength, and provides good protection for the pressure relief groove 2132. When H ≤ 0.14 mm, the thickness of the protective member 22 is not too large, and the strength is not too high. When the battery cell 20 releases pressure, the protective member 22 can be destroyed, thereby facilitating the first wall portion 213 to open a larger opening to release pressure.

[0163] Optionally, 0.055mm≤H≤0.11mm.

[0164] The thickness of the protective member 22 may be: H=0.055 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, etc.

[0165] When H ≥ 0.055 mm, the thickness of the protective member 22 is greater, the protective member 22 has higher strength, and provides better protection for the pressure relief groove 2132. When H ≤ 0.11 mm, the thickness of the protective member 22 is not too large, and the strength is not too high. When the battery cell 20 releases pressure, the protective member 22 can be destroyed, making it easier for the first wall portion 213 to open a larger opening to release pressure, thereby facilitating rapid pressure relief for the battery cell 20.

[0166] In some embodiments, the pressure relief groove 2132 extends along a non-enclosed trajectory.

[0167] The pressure relief groove 2132 extends along a non-closed track, with a gap between the two ends of the pressure relief groove 2132. For example, the pressure relief groove 2132 can extend along a C-shaped track. For another example, the pressure relief groove 2132 can extend along a U-shaped track.

[0168] The pressure relief groove 2132 is set to extend along a non-closed trajectory. When the battery cell 20 releases pressure, the predetermined pressure relief area 2133 will open outward in a flipped form. After opening, the predetermined pressure relief area 2133 is still partially connected to other parts of the first wall portion 213 except the predetermined pressure relief area 2133. The predetermined pressure relief area 2133 will not detach and fly out due to the rapid discharge of emissions.

[0169] 3 , 4 , 5 , 6 and 7 , in some embodiments, the pressure relief groove 2132 includes a first groove section 2132a , a second groove section 2132b and a third groove section 2132c , the first groove section 2132a and the third groove section 2132c are arranged opposite to each other, and the second groove section 2132b connects the first groove section 2132a and the third groove section 2132c .

[0170] The first slot segment 2132a and the third slot segment 2132c are spaced apart and at least partially opposite to each other. Optionally, the first slot segment 2132a and the third slot segment 2132c are both straight slot segments.

[0171] The second slot segment 2132b connects the first slot segment 2132a and the third slot segment 2132c, that is, the second slot segment 2132b is located between the first slot segment 2132a and the third slot segment 2132c, and the two ends of the second slot segment 2132b are respectively connected to the first slot segment 2132a and the third slot segment 2132c. Of course, in other embodiments, the two ends of the second slot segment 2132b can extend from the first slot segment 2132a and the third slot segment 2132c, respectively.

[0172] The line connecting the free ends of the first slot segment 2132a and the third slot segment 2132c is a first line, and the first line is disposed opposite the second slot segment 2132b. The enclosed area collectively enclosed by the first slot segment 2132a, the second slot segment 2132b, the third slot segment 2132c, and the first line is the predetermined pressure relief zone 2133. In other words, the first slot segment 2132a, the second slot segment 2132b, and the third slot segment 2132c are arranged along the edge of the predetermined pressure relief zone 2133, so that the predetermined pressure relief zone 2133 can be opened with the first slot segment 2132a, the second slot segment 2132b, and the third slot segment 2132c as the boundary. In other words, the predetermined pressure relief zone 2133 is formed within the area enclosed by the first slot segment 2132a, the second slot segment 2132b, and the third slot segment 2132c.

[0173] 3 and 4 , the pressure relief groove 2132 formed by the first groove section 2132a, the second groove section 2132b, and the third groove section 2132c can be in a U-shaped structure, where one end of the second groove section 2132b is connected to one end of the first groove section 2132a, and the other end is connected to one end of the third groove section 2132c, thereby forming a predetermined pressure relief area 2133 on the first wall portion 213. In this case, the first connecting line closes the open end of the U-shaped structure.

[0174] In other embodiments, the shape of the pressure relief groove 2132 formed by the first groove segment 2132a, the second groove segment 2132b and the third groove segment 2132c can be similar to an "H"-shaped structure. In this case, one end of the second groove segment 2132b is connected between the two ends of the first groove segment 2132a, and the other end of the second groove segment 2132b is connected between the two ends of the third groove segment 2132c.

[0175] In yet other embodiments, the pressure relief groove 2132 extends along a closed trajectory.

[0176] The pressure relief groove 2132 extends along a closed track, that is, the pressure relief groove 2132 is an annular groove.

[0177] By extending the pressure relief groove 2132 along a closed track, when the battery cell 20 releases pressure, the predetermined pressure relief area 2133 will be completely separated from other parts of the first wall portion 213 except the predetermined pressure relief area 2133 , thereby having a larger pressure relief area.

[0178] In some embodiments, the housing 21 includes a shell 211 and an end cap 212 . The shell 211 has an opening, and the end cap 212 is disposed on the shell 211 and closes the opening. The at least one wall portion of the shell 211 is a first wall portion 213 .

[0179] In some embodiments, the outer shell 21 may include a shell 211 and two end covers 212. A accommodating cavity is formed inside the shell 211, and the accommodating cavity is used to accommodate the electrode assembly 23. Openings are formed at both ends of the shell 211, and both openings are connected to the accommodating cavity. The two end covers 212 respectively close the two openings, and the shell 211 is the first wall portion 213.

[0180] In other embodiments, the housing 211 includes an integrally formed sidewall and bottom wall. Specifically, the housing 211 is manufactured using an integral molding process, such as stamping, casting, or extrusion. In other words, the sidewall and bottom wall of the housing 211 are an integral structure. An opening is formed at one end of the housing 211, and the opening is disposed opposite the bottom wall. In this case, one of the sidewall and the bottom wall serves as the first wall portion 213.

[0181] When the shell 211 includes the first wall portion 213 , the pressure relief groove 2132 is provided on a wall portion of the shell 211 , and the ejected fluid medium is less likely to act on other electrical connection structures on the end cover 212 , which is beneficial to reducing the risk of short circuit of the battery cell 20 .

[0182] 3 and 4 , in some embodiments, the housing 211 is a cylindrical structure, and a wall portion of the housing 211 disposed around a center line thereof is a first wall portion 213 .

[0183] In some embodiments, the housing 21 may include a shell 211 and two end caps 212. The shell 211 has an interior formed with a housing cavity for accommodating the electrode assembly 23. Both ends of the shell 211 have openings, both openings communicating with the housing cavity. The two end caps 212 respectively seal the two openings. The shell 211 is a cylindrical structure, and the shell 211 itself serves as the first wall portion 213.

[0184] In other embodiments, the shell 211 includes an integrally formed side wall and bottom wall, wherein the side wall is a wall portion of the shell 211 arranged around the center line thereof, that is, the side wall is the first wall portion 213 .

[0185] The peripheral wall of the cylindrical structure is the first wall portion 213. The peripheral wall has a large area, which is convenient for setting the pressure relief groove 2132. In addition, the protective member 22 can be covered on the outer side of the peripheral wall to better protect the pressure relief groove 2132.

[0186] The embodiment of the present application further provides a battery 100 , which includes the above-mentioned battery cell 20 .

[0187] An embodiment of the present application further provides an electrical device, which includes the above-mentioned battery cell 20.

[0188] According to some embodiments of the present application, please refer to Figures 3 to 8.

[0189] An embodiment of the present application provides a battery cell 20, which includes a housing 21 and a protective member 22. The housing 21 includes a first wall portion 213, which has an outer surface provided with a pressure relief groove 2132. The first wall portion 213 is configured to rupture along the pressure relief groove 2132 when the battery cell 20 releases pressure. The protective member 22 is provided on the outer surface, shielding the pressure relief groove 2132. Along the thickness direction of the first wall portion 213, a gap is provided between the protective member 22 and the notch of the pressure relief groove 2132. The first wall portion 213 of the battery cell 20 is provided with the protective member 22. The protective member 22 has a certain strength and can resist external interference, protect the pressure relief groove 2132, and also limit deformation of the first wall portion 213, thereby reducing the risk of the first wall portion 213 rupturing along the pressure relief groove 2132 due to pressure changes within the battery cell 20. In addition, by setting a gap between the protective member 22 and the notch of the pressure relief groove 2132, the protective member 22 is not likely to prevent the first wall portion 213 from cracking along the pressure relief groove 2132 when the battery cell 20 releases pressure, so that the pressure relief groove 2132 can quickly crack and release pressure when the battery cell 20 releases pressure, which is beneficial to improving the reliability of the battery cell 20.

[0190] The outer surface is provided with a protrusion 25, which contacts the protective member 22 to ensure a gap between the protective member 22 and the opening of the pressure relief groove 2132. The protrusion 25 on the outer surface allows the protective member 22 to conform to the outer surface and the protrusion 25, not only protecting the pressure relief groove 2132 but also limiting deformation of the first wall 213, reducing the risk of premature cracking of the first wall 213 along the pressure relief groove 2132 due to pressure changes within the battery cell 20. Because the protrusion 25 protrudes from the outer surface, when the protective member 22 is positioned between the outer surface and the protrusion 25, the protective member 22 can straddle the opening of the pressure relief groove 2132, ensuring a gap between the protective member 22 and the opening of the pressure relief groove 2132.

[0191] The pressure relief groove 2132 defines a predetermined pressure relief area 2133. The predetermined pressure relief area 2133 is configured to split with the pressure relief groove 2132 as the boundary when the battery cell 20 releases pressure. The protrusion 25 is located in the predetermined pressure relief area 2133. The pressure relief groove 2132 defines the predetermined pressure relief area 2133, and the protrusion 25 is disposed in the predetermined pressure relief area 2133. It can also be understood that the pressure relief groove 2132 is disposed around the outside of the protrusion 25. In this way, when the protective member 22 contacts the protrusion 25 and the outer surface, it can better shield the pressure relief groove 2132 and be provided with a gap from the opening of the pressure relief groove 2132.

[0192] The protective member 22 includes an insulating layer 221 and a first adhesive layer 222. The first adhesive layer 222 is disposed on one side of the insulating layer 221 and connects the first wall portion 213 to the insulating layer 221. The insulating layer 221 of the protective member 22 provides insulation and isolation, reducing the risk of short circuits caused by contact between other components and the first wall portion 213. The protective member 22 also includes the first adhesive layer 222, which is sticky and allows for quick bonding of the protective member 22 to the first wall portion 213.

[0193] The protective member 22 includes a second adhesive layer 223 and a plurality of insulating layers 221. The plurality of insulating layers 221 are stacked, and two adjacent insulating layers 221 are connected by the second adhesive layer 223. By providing a plurality of insulating layers 221, the plurality of insulating layers 221 are stacked, and the plurality of insulating layers 221 can provide higher strength and better insulation. The two adjacent insulating layers 221 are connected by the second adhesive layer 223, so that the protective member 22 has better toughness, and the protective member 22 is more likely to adhere to the shell 211 to better protect the pressure relief groove 2132, limit the deformation of the first wall portion 213, and reduce the risk of the pressure relief groove 2132 being subjected to pressure changes inside the battery cell 20, causing the first wall portion 213 to crack prematurely along the pressure relief groove 2132.

[0194] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, wherein: include: The housing includes a first wall portion, the first wall portion having a first surface, the first surface being provided with a pressure relief groove, and the first wall portion being configured to be able to rupture along the pressure relief groove when the battery cell releases pressure; A protective member is provided on the first surface, the protective member shields the pressure relief groove, and a gap is provided between the protective member and the notch of the pressure relief groove along the thickness direction of the first wall portion.

2. The battery cell according to claim 1, wherein: The first surface is provided with a protrusion, and the protrusion contacts the protection member so that a gap is set between the protection member and the notch of the pressure relief groove.

3. The battery cell according to claim 2, wherein: The pressure relief groove defines a predetermined pressure relief area, and the predetermined pressure relief area is configured to be split with the pressure relief groove as a boundary when the battery cell is pressure-relieved. The protrusion is located in the predetermined pressure relief area.

4. The battery cell according to any one of claims 1 to 3, wherein: The first surface is a surface of the first wall portion facing away from the interior of the housing.

5. The battery cell according to any one of claims 1 to 4, wherein: The protection member includes an insulating layer and a first adhesive layer, wherein the first adhesive layer is provided on one side of the insulating layer and connects the first wall portion and the insulating layer.

6. The battery cell according to claim 5, wherein: The protective member includes a second adhesive layer and a plurality of insulating layers. The plurality of insulating layers are stacked, and two adjacent insulating layers are connected via the second adhesive layer.

7. The battery cell according to claim 5 or 6, wherein: The insulating layer is made of polyethylene terephthalate or polyimide.

8. The battery cell according to any one of claims 1 to 7, wherein: The protection member is configured to be destroyed when the battery cell is depressurized.

9. The battery cell according to any one of claims 1 to 8, wherein: The protective member is an insulating film.

10. The battery cell according to any one of claims 1 to 9, wherein: The thickness of the protective member is H, which satisfies: 0.02mm≤H≤0.14mm.

11. The battery cell according to claim 10, wherein: 0.055mm≤H≤0.11mm.

12. The battery cell according to any one of claims 1 to 11, wherein: The pressure relief groove extends along a non-closed track.

13. The battery cell according to claim 12, wherein: The pressure relief groove includes a first groove section, a second groove section and a third groove section. The first groove section is arranged opposite to the third groove section, and the second groove section connects the first groove section and the third groove section.

14. The battery cell according to any one of claims 1 to 13, wherein: The pressure relief groove extends along a closed track.

15. The battery cell according to any one of claims 1 to 14, wherein: The housing comprises: a housing having an opening; an end cover, disposed on the housing and closing the opening; Wherein, at least one wall portion in the shell is the first wall portion.

16. The battery cell according to claim 15, wherein: The shell is a cylindrical structure, and the wall portion of the shell arranged around the center line thereof is the first wall portion.

17. A battery, wherein: The battery cell comprises the battery cell according to any one of claims 1 to 16.

18. An electrical device, wherein: The battery cell comprises the battery cell according to any one of claims 1 to 16.

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