Battery cell, battery, and electric device

Abstract

The application discloses a battery monomer, a battery and a power utilization device. The battery monomer comprises a shell, an electrode assembly, an insulating piece and a patch. The electrode assembly is accommodated in the shell. The insulating piece is arranged outside the electrode assembly, and the insulating piece has a first outer surface on a side away from the electrode assembly. The patch is attached to the first outer surface and covers a part of the first outer surface, and the patch has a second outer surface on a side away from the insulating piece, and the surface roughness of at least a partial area of the second outer surface is greater than the surface roughness of the first outer surface.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application 202310417400.1, filed on April 18, 2023, entitled “Battery cell, battery and electrical device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of batteries, and in particular to a battery cell, a battery, and an electrical device. Background Technology

[0004] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0005] In the development of battery technology, improving the reliability of individual battery cells is a key research direction. Summary of the Invention

[0006] This application provides a battery cell, a battery, and an electrical device that can improve reliability.

[0007] In a first aspect, this application provides a battery cell including a housing, an electrode assembly, an insulating member, and a patch. The electrode assembly is housed within the housing. The insulating member is disposed on the outer side of the electrode assembly and has a first outer surface on a side facing away from the electrode assembly. The patch is attached to and covers a portion of the first outer surface, and has a second outer surface on a side facing away from the insulating member, wherein at least a portion of the second outer surface has a surface roughness greater than that of the first outer surface.

[0008] During the molding process of a battery cell, metal particles may remain inside the casing. Insulating components protect the electrode assembly, reducing the likelihood of metal particles puncturing it, lowering the risk of short circuits, and improving the reliability of the battery cell. The second outer surface of the patch has a large surface roughness. When the battery cell is subjected to external impact, the patch experiences greater frictional resistance. This, combined with the insulating component, reduces the slippage of the electrode assembly within the casing, lowering the risk of battery cell failure and improving its reliability. The patch only covers a portion of the first outer surface, and its edges form a stepped structure protruding from the first outer surface. This stepped structure also increases the resistance to patch movement when the battery cell is subjected to external impact, thereby reducing the slippage of the electrode assembly within the casing.

[0009] In some embodiments, the patch includes a base layer and an adhesive layer, the adhesive layer being disposed between a first outer surface and the base layer and bonding the first outer surface and the base layer. The base layer includes a second outer surface.

[0010] By incorporating an adhesive layer, the base layer can be bonded to the first outer surface, reducing relative slippage between the base layer and the insulating components when the battery cell is subjected to external impact. The base layer can also separate the adhesive layer from the outer casing, thereby reducing the risk of frictional wear on the adhesive layer.

[0011] In some embodiments, the second outer surface is provided with a plurality of protrusions spaced apart. By providing protrusions on the second outer surface, the surface roughness of the second outer surface is increased, thereby increasing the frictional resistance of the patch when the battery cell is subjected to external impact, reducing the slippage of the electrode assembly within the housing, reducing the risk of battery cell failure, and improving the reliability of the battery cell.

[0012] In some embodiments, the protrusions are curved. Curved protrusions can generate greater frictional resistance in multiple directions, thereby effectively reducing the slippage of the electrode assembly within the housing, reducing the risk of battery cell failure, and improving the reliability of the battery cell.

[0013] In some embodiments, the two ends of the protrusion extend to two opposite edges of the second outer surface, respectively. The protrusion has a large extension length, which increases the contact area between the protrusion and the housing, thereby increasing the frictional resistance when the battery cell is subjected to external impact, and thus effectively reducing the slippage of the electrode assembly within the housing.

[0014] In some embodiments, a battery cell includes multiple patches, which are spaced apart.

[0015] Given a consistent total area, attaching multiple smaller patches, compared to attaching a single, larger patch, can result in more uniform resistance to the electrode assembly when the battery cell is subjected to external impacts, reducing the risk of electrode assembly misalignment. Furthermore, each patch's edge can form a stepped structure protruding from the first outer surface, which can also increase the resistance to patch movement when the battery cell is subjected to external impacts.

[0016] In some embodiments, a plurality of patches are arranged at circumferential intervals along the electrode assembly.

[0017] In some embodiments, a plurality of patches are spaced apart in a direction perpendicular to the circumferential direction.

[0018] In some embodiments, a plurality of patches are spaced apart along the circumference of the electrode assembly and in a direction perpendicular to the circumference.

[0019] In some embodiments, the surface roughness of the second outer surface is greater than or equal to 10 μm. The larger surface roughness of the second outer surface results in greater frictional resistance to the patch when the battery cell is subjected to external impact, thereby reducing the slippage of the electrode assembly within the casing, lowering the risk of battery cell failure, and improving the reliability of the battery cell.

[0020] In some embodiments, the surface roughness of the second outer surface is Ra, where Ra satisfies: 10μm≤Ra≤3600μm. Setting Ra to 10μm-3600μm balances the frictional resistance experienced by the patch and the space occupied by the patch, thereby reducing the energy density loss of the battery cell while ensuring that the frictional resistance experienced by the patch meets the requirements.

[0021] In some embodiments, 300μm≤Ra≤600μm is used to further balance the frictional resistance of the patch and the space occupied by the patch, thereby reducing the energy density loss of the battery cell while ensuring that the frictional resistance of the patch meets the requirements.

[0022] In some embodiments, the total area of ​​the first outer surface is S1, the area of ​​the region of the first outer surface covered by the patch is S2, and 0.02≤S2 / S1≤0.5.

[0023] S2 / S1 is positively correlated with the frictional resistance experienced by the patch and also with the space occupied by the patch. Limiting S2 / S1 to 0.02-0.5 can balance the frictional resistance experienced by the patch and the space occupied by the patch, thereby reducing the energy density loss of the battery cell while ensuring that the frictional resistance experienced by the patch meets the requirements.

[0024] In some embodiments, the electrode assembly includes wound electrodes and spacers. An insulating member is attached to the spacer and serves to restrain the wound ends of the spacer. The insulating member can restrain the spacer to reduce the risk of the spacer unraveling and minimize deformation of the electrode assembly.

[0025] In some embodiments, an insulating element surrounds the electrode assembly. This effectively covers the outer peripheral surface of the electrode assembly, reducing the risk of the electrode assembly being punctured by metal particles.

[0026] In some embodiments, the patch and the winding end of the electrode do not overlap in the thickness direction of the patch.

[0027] During charging, the electrode assembly expands, pressing against the outer casing through the patch. Conversely, the outer casing exerts a reaction force on the electrode assembly through the patch. If the patch overlaps with the winding end of the electrode, the winding end of the electrode will be subjected to a large reaction force, causing stress concentration and potentially leading to electrode breakage. The above-mentioned technical solution prevents the winding ends of the patch and electrode from overlapping, reducing stress concentration, lowering the risk of electrode breakage, and improving the cycle performance of the battery cell.

[0028] In a second aspect, this application provides a battery comprising a plurality of battery cells provided according to any embodiment of the first aspect.

[0029] Thirdly, this application provides an electrical device that includes a battery cell provided according to any embodiment of the first aspect, the battery cell being used to provide electrical energy. Attached Figure Description

[0030] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0031] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0032] Figure 2 Explosion diagrams of batteries provided for some embodiments of this application;

[0033] Figure 3 for Figure 2 The diagram shows the structure of the battery module.

[0034] Figure 4 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0035] Figure 5 for Figure 4 The diagram shows an exploded battery cell;

[0036] Figure 6 Schematic diagrams of the electrode assembly, insulating components, and patches of a battery cell provided in some embodiments of this application;

[0037] Figure 7 for Figure 6 The diagram shows a cross-sectional view of the electrode assembly, insulating components, and patch.

[0038] Figure 8 A schematic diagram of the patch provided in some embodiments of this application in a flattened state;

[0039] Figure 9 for Figure 8 A cross-sectional view of the patch shown;

[0040] Figure 10 Schematic diagrams of electrode assemblies, insulating components, and patches for battery cells provided in other embodiments of this application;

[0041] Figure 11 This is a schematic diagram of the electrode assembly, insulating component, and patch of a battery cell provided in some embodiments of this application.

[0042] The accompanying drawings are not necessarily drawn to scale. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0046] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0047] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0048] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0049] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0050] In this application, "multiple" means two or more (including two).

[0051] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0052] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0053] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0054] 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.

[0055] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0056] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0057] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional 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. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides 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, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.80 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0058] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal may also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0059] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0060] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can 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.).

[0061] 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.

[0062] As an example, the negative electrode current collector has two surfaces opposite each other in its own 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.

[0063] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. 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, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0064] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0065] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0066] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0067] As an example, the main 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 located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0068] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0069] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0070] Liquid electrolytes include electrolyte salts and solvents.

[0071] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0072] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents 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, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0073] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0074] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0075] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0076] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium-germanium-phosphorus-sulfur, sulfosilium-germanium), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0077] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0078] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0079] In some implementations, the electrode assembly is a stacked structure.

[0080] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0081] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0082] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0083] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0084] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0085] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0086] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0087] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0088] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0089] In some embodiments, the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0090] In some embodiments, the battery can be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.

[0091] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0092] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0093] In some embodiments, the battery cell may include a casing. The casing is used to encapsulate components such as electrode assemblies and electrolytes. The casing can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc. The casing can protect the electrode assemblies from the outside to prevent external foreign objects from affecting the charging or discharging of the electrode assemblies.

[0094] The battery cell may also include an insulating component disposed on the outside of the electrode assembly. The insulating component can protect the electrode assembly, reduce the possibility of metal particles puncturing the electrode assembly, reduce the risk of short circuits, and improve the reliability of the battery cell. However, the outer surface of the insulating component is relatively smooth, and when the battery cell is subjected to external impact, the insulating component experiences less frictional resistance, which makes the electrode assembly prone to vibration and slippage within the casing, increasing the risk of battery cell failure (for example, the tabs are easily torn when the electrode assembly slips), thus affecting the reliability of the battery cell.

[0095] In view of this, the present application provides a technical solution that reduces the slippage of the electrode assembly in the housing when the battery cell is subjected to external impact, thereby reducing the risk of battery cell failure and improving the reliability of the battery cell by attaching a patch with a high surface roughness to the outside of the insulating component.

[0096] The technical solutions described in the embodiments of this application are applicable to batteries and electrical devices that use batteries.

[0097] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0098] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0099] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0100] like Figure 1 As shown, a battery 2 is installed inside the vehicle 1. The battery 2 can be located at the bottom, front, or rear of the vehicle 1. The battery 2 can be used to power the vehicle 1; for example, the battery 2 can serve as the operating power source for the vehicle 1.

[0101] Vehicle 1 may also include controller 3 and motor 4. Controller 3 is used to control battery 2 to supply power to motor 4, for example, for the power needs of vehicle 1 during start-up, navigation and driving.

[0102] In some embodiments of this application, the battery 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0103] Figure 2 This is an exploded schematic diagram of a battery provided for some embodiments of this application.

[0104] like Figure 2 As shown, battery 2 includes a housing 5 and battery cells (not shown), with the battery cells housed within the housing 5.

[0105] The housing 5 is used to house individual battery cells, and the housing 5 can have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, and together define a housing space 5c for housing the individual battery cells. The second housing portion 5b may be a hollow structure with one end open, and the first housing portion 5a may be a plate-like structure, with the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c; alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one side open, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c. Of course, the first housing portion 5a and the second housing portion 5b can have various shapes, such as cylinders, cuboids, etc.

[0106] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0107] Assuming that the first box section 5a covers the top of the second box section 5b, the first box section 5a can also be called the upper box cover, and the second box section 5b can also be called the lower box.

[0108] In battery 2, there can be one or more individual battery cells. If there are multiple individual battery cells, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple individual battery cells are connected in both series and parallel configurations. Multiple individual battery cells can be directly connected in series, parallel, or in a mixed configuration and then housed within housing 5. Alternatively, multiple individual battery cells can first be connected in series, parallel, or in a mixed configuration to form battery module 6, and then multiple battery modules 6 can be connected in series, parallel, or in a mixed configuration to form a whole and housed within housing 5.

[0109] Figure 3 for Figure 2 The diagram shows the structure of the battery module.

[0110] like Figure 3 As shown, in some embodiments, there are multiple battery cells 7, which are first connected in series, parallel, or mixed to form a battery module 6. The multiple battery modules 6 are then connected in series, parallel, or mixed to form a whole and housed in a casing.

[0111] Multiple battery cells 7 in battery module 6 can be electrically connected through a busbar component to achieve parallel, series, or mixed connection of multiple battery cells 7 in battery module 6.

[0112] The battery cell 7 can be a cylindrical battery cell, a square battery cell, or a battery cell of other shapes.

[0113] Figure 4 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application; Figure 5 for Figure 4 The diagram shows an exploded battery cell; Figure 6 Schematic diagrams of the electrode assembly, insulating components, and patches of a battery cell provided in some embodiments of this application; Figure 7 for Figure 6 The diagram shows a cross-sectional view of the electrode assembly, insulating components, and patch.

[0114] like Figures 4 to 7 As shown, the battery cell 7 of this embodiment includes a housing 20, an electrode assembly 10, an insulating member 30, and a patch 40. The electrode assembly 10 is housed within the housing 20. The insulating member 30 is disposed on the outer side of the electrode assembly 10, and has a first outer surface 30a on the side facing away from the electrode assembly 10. The patch 40 is attached to the first outer surface 30a and covers a portion of the first outer surface 30a. The patch 40 has a second outer surface 40a on the side facing away from the insulating member 30, and the surface roughness of at least a portion of the second outer surface 40a is greater than the surface roughness of the first outer surface 30a.

[0115] The outer shell 20 is a hollow structure, forming an internal space for accommodating the electrode assembly 10 and the electrolyte. The shape of the outer shell 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a cuboid structure, a cuboid outer shell can be used; if the electrode assembly 10 is a cylindrical structure, a cylindrical outer shell can be used.

[0116] The outer casing 20 can be made of various materials, such as metal or plastic. Alternatively, the outer casing 20 can be made of copper, iron, aluminum, steel, aluminum alloy, etc.

[0117] There may be one or more electrode assemblies 10. When there are multiple electrode assemblies 10, they can be stacked. As an example, there are multiple electrode assemblies 10, and at least one electrode assembly 10 has an insulating member 30 attached to its outer peripheral surface.

[0118] The number of patch 40 can be one or more.

[0119] The patch 40 only covers a portion of the first outer surface 30a; in other words, a portion of the first outer surface 30a is not covered by the patch 40.

[0120] In the embodiments of this application, "attachment" can mean attaching and connecting. For example, patch 40 may be attached to the first outer surface 30a by adhesive, coating or other means.

[0121] In some examples, the surface roughness of the entire area of ​​the second outer surface 40a is greater than the surface roughness of the first outer surface 30a. In other examples, the surface roughness of a portion of the second outer surface 40a is greater than the surface roughness of the first outer surface 30a.

[0122] For example, when measuring the roughness of a region of the first outer surface 30a, a unit area can be cut off in the region of the insulating member 30 for measurement. Optionally, a circle with a diameter of 10 mm can be cut off for measurement.

[0123] For example, when measuring the roughness of a certain area of ​​the second outer surface 40a, a unit area of ​​that area of ​​the patch 40 can be measured. Optionally, a circle with a diameter of 10 mm can be measured.

[0124] During the molding process of the battery cell 7, metal particles may remain inside the casing 20. The insulating component 30 can protect the electrode assembly 10, reduce the possibility of metal particles puncturing the electrode assembly 10, reduce the risk of short circuit, and improve the reliability of the battery cell 7. The second outer surface 40a of the patch 40 has a large surface roughness. When the battery cell 7 is subjected to external impact, the patch 40 experiences greater frictional resistance. This reduces the slippage of the electrode assembly 10 within the casing 20 through the insulating component 30, reducing the risk of battery cell 7 failure and improving the reliability of the battery cell 7. The patch 40 only covers a portion of the first outer surface 30a, and the edge of the patch 40 forms a stepped structure protruding from the first outer surface 30a. The stepped structure can also increase the resistance to movement of the patch 40 when the battery cell 7 is subjected to external impact, thereby reducing the slippage of the electrode assembly 10 within the casing 20.

[0125] The patch 40 only covers a portion of the first outer surface 30a, which can reduce the space occupied by the patch 40 and increase the energy density of the battery cell 7.

[0126] In some embodiments, during the production of the battery cell 7, a fixture is typically required to hold the electrode assembly 10 for transfer or processing (e.g., flattening the tabs of the electrode assembly 10). Covering the electrode assembly 10 with an insulating member 30 and a patch 40 can also reduce direct contact between the fixture and the electrode assembly 10, lowering the risk of damage to the separator and electrode sheets. Furthermore, the fixture can hold the patch 40, and the second outer surface 40a of the patch 40 has a large surface roughness, which can reduce the relative slippage between the patch 40 and the fixture during the processing of the electrode assembly 10, reducing the risk of misalignment of the electrode sheets and separator due to slippage, and improving the reliability of the electrode assembly 10.

[0127] For example, during the flattening process of the tab, the flattening device applies a pushing force to the electrode assembly 10. The second outer surface 40a of the patch 40 has a large surface roughness, which can reduce the relative slippage between the patch 40 and the fixture under the pushing force, reduce the misalignment of the separator, and reduce the risk of the separator being burned in subsequent welding processes.

[0128] In some embodiments, the housing 20 includes a housing 21 and an end cap 22, the housing 21 having an opening and the end cap 22 for closing the opening.

[0129] The housing 21 is a component used to fit the end cap 22 to form the internal cavity of the battery cell 7. The formed internal cavity can be used to accommodate the electrode assembly 10, the electrolyte, and other components.

[0130] The housing 21 and the end cap 22 can be separate components. For example, an opening can be provided on the housing 21, and the end cap 22 can be used to close the opening to form an internal cavity for the battery cell 7.

[0131] The housing 21 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 21 can be determined according to the specific shape and size of the electrode assembly 10. The material of the housing 21 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and this application embodiment does not impose any special limitations on this.

[0132] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. Optionally, the end cap 22 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 22 is not easily deformed when subjected to compression and impact, so that the battery cell 7 can have higher structural strength and improved reliability.

[0133] The end cap 22 is connected to the housing 21 by welding, bonding, snap-fitting or other means.

[0134] In some examples, the housing 21 may be an open structure on one side, with one end cap 22 covering the housing 21. In other examples, the housing 21 may be an open structure on both sides, with two end caps 22 covering the two openings of the housing 21 respectively.

[0135] In some embodiments, the battery cell 7 further includes an electrode terminal 50 disposed on the housing 20, the electrode terminal 50 being electrically connected to the electrode assembly 10.

[0136] In some embodiments, at least a portion of the electrode terminal 50 is exposed outside the housing 20 to enable electrical connection with other structures (e.g., busbar components). The electrode terminal 50 can be used to electrically connect the electrode assembly 10 to external circuitry of the battery cell 7 to enable charging and discharging.

[0137] There may be one or more electrode terminals 50. In some examples, there is one electrode terminal 50, with one of the electrode terminal 50 and the housing 20 electrically connected to the positive electrode and the other electrically connected to the negative electrode. The electrode terminal 50 and the housing 20 serve as the two output electrodes of the battery cell 7. In other examples, there are two electrode terminals 50, with one electrode terminal 50 electrically connected to the positive electrode and the other electrode terminal 50 electrically connected to the negative electrode.

[0138] In some embodiments, electrode terminals 50 are disposed on end caps 22.

[0139] In some embodiments, there are two end caps 22 and two electrode terminals 50, with the two electrode terminals 50 respectively disposed on the two end caps 22.

[0140] In some embodiments, the surface roughness of at least a portion of the second outer surface 40a is greater than or equal to 10 μm.

[0141] At least a portion of the second outer surface 40a has a large surface roughness. When the battery cell 7 is subjected to external impact, the patch 40 experiences greater frictional resistance, thereby reducing the slippage of the electrode assembly 10 within the housing 20, reducing the risk of battery cell 7 failure, and improving the reliability of the battery cell 7.

[0142] In some embodiments, the surface roughness of the second outer surface 40a is greater than or equal to 10 μm.

[0143] The surface roughness of the entire area of ​​the second outer surface 40a is greater than or equal to 10 μm. In other words, any unit area of ​​the sample cut from the patch 40 has a surface roughness greater than or equal to 10 μm.

[0144] The second outer surface 40a has a large surface roughness. When the battery cell 7 is subjected to external impact, the patch 40 experiences greater frictional resistance, thereby reducing the slippage of the electrode assembly 10 within the housing 20, reducing the risk of battery cell 7 failure, and improving the reliability of the battery cell 7.

[0145] In addition, during the production of the battery cell 7, the fixture can hold any area of ​​the patch 40, which can improve production efficiency.

[0146] In some embodiments, the surface roughness of the second outer surface 40a is greater than or equal to 100 μm, so as to further increase the frictional resistance of the patch 40 when the battery cell 7 is subjected to external impact, thereby reducing the slippage of the electrode assembly 10 in the housing 20, reducing the risk of battery cell 7 failure, and improving the reliability of battery cell 7.

[0147] In some embodiments, the surface roughness of the second outer surface 40a is Ra, where Ra satisfies: 10μm≤Ra≤3600μm.

[0148] The greater the surface roughness of the second outer surface 40a, the greater the overall thickness of the patch 40, and the larger the space occupied by the patch 40.

[0149] In this embodiment, Ra is set to 10μm-3600μm to balance the frictional resistance of the patch 40 and the space occupied by the patch 40. Under the premise that the frictional resistance of the patch 40 meets the requirements, the energy density loss of the battery cell 7 is reduced.

[0150] Alternatively, Ra is 10 μm, 20 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 800 μm, 1000 μm, 1500 μm, 2000 μm, 2500 μm, 3000 μm, 3200 μm, 3400 μm or 3600 μm.

[0151] In some embodiments, 300μm≤Ra≤600μm is used to further balance the frictional resistance of the patch 40 and the space occupied by the patch 40, thereby reducing the energy density loss of the battery cell 7 under the premise that the frictional resistance of the patch 40 meets the requirements.

[0152] In some embodiments, the total area of ​​the first outer surface 30a is S1, and the area of ​​the region of the first outer surface 30a covered by the patch 40 is S2. 0.02≤S2 / S1≤0.5.

[0153] For example, when there are multiple patches 40, S2 is the total area of ​​the area of ​​the first outer surface 30a covered by the multiple patches 40.

[0154] S2 / S1 is positively correlated with the frictional resistance experienced by patch 40 and also with the space occupied by patch 40.

[0155] The embodiments of this application can balance the frictional resistance of the patch 40 and the space occupied by the patch 40, and reduce the loss of energy density of the battery cell 7 under the premise that the frictional resistance of the patch 40 meets the requirements.

[0156] Optionally, S2 / S1 can be 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 or 0.5.

[0157] In some embodiments, the electrode assembly 10 includes a wound electrode 11 and a spacer 12. An insulating member 30 is attached to the spacer 12 and serves to restrain the wound end 12a of the spacer 12.

[0158] The electrode assembly 10 may include multiple electrode plates 11, which may include positive electrode plates and negative electrode plates. The separator 12 may be disposed between the positive electrode plates and the negative electrode plates to prevent short circuit between the positive and negative electrodes, while allowing active ions to pass through.

[0159] The electrode assembly 10 can be cylindrical, flat, or polygonal. Optionally, the electrode assembly 10 is cylindrical.

[0160] As an example, electrode assembly 10 has a wound structure.

[0161] When the spacer 12 is in a flattened state, its two ends along its length are a winding start end 12b and a winding end end 12a. When in a wound state, the winding start end 12b is closer to the interior of the electrode assembly 10, and the winding end end 12a is closer to the exterior of the electrode assembly 10. During the winding and forming process of the electrode assembly 10, the spacer 12 begins to wind from the winding start end 12b and stops winding at the winding end end 12a.

[0162] The insulating member 30 can restrain the isolator 12 to reduce the risk of the isolator 12 coming apart and reduce the deformation of the electrode assembly 10.

[0163] In some embodiments, along the winding direction of the electrode assembly 10, the insulating member 30 extends in a dimension greater than or equal to 1 / 4 of the circumference of the outer peripheral surface 10a of the electrode assembly 10. Optionally, the insulating member 30 extends in a dimension greater than or equal to 1 / 2 of the circumference of the outer peripheral surface 10a of the electrode assembly 10.

[0164] In some embodiments, the insulating member 30 surrounds the electrode assembly 10. Of course, due to manufacturing errors, the two ends of the insulating member 30 along the winding direction may not be perfectly aligned, and a small gap may be left between the two ends of the insulating member 30, and the two ends of the insulating member 30 may also overlap.

[0165] The insulating component 30 surrounds the electrode assembly 10, effectively covering the outer peripheral surface 10a of the electrode assembly 10 and reducing the risk of the electrode assembly 10 being punctured by metal particles.

[0166] In some embodiments, the electrode assembly 10 is cylindrical. The outer peripheral surface 10a of the electrode assembly 10 is approximately cylindrical.

[0167] For example, the insulating member 30 is generally bent into an arc shape. Correspondingly, the first outer surface 30a of the insulating member 30 is generally an arc surface. Optionally, the insulating member 30 may be a rectangular sheet in its flattened state.

[0168] In some embodiments, the patch 40 does not overlap with the winding end 11a of the electrode 11 in the thickness direction of the patch 40.

[0169] As an example, when patch 40 is bent into an arc shape, the thickness direction of patch 40 at any point can be the normal direction at that point.

[0170] During charging, the electrode assembly 10 expands. The expanded electrode assembly 10 compresses the outer casing 20 through the patch 40, and correspondingly, the outer casing 20 also exerts a reaction force on the electrode assembly 10 through the patch 40. If the patch 40 overlaps with the winding end 11a of the electrode 11, the winding end 11a of the electrode 11 will be subjected to a large reaction force, causing stress concentration and even posing a risk of the electrode 11 breaking. In this embodiment, the patch 40 and the winding end 11a of the electrode 11 do not overlap, which reduces the force on the winding end 11a of the electrode 11, reduces stress concentration, reduces the risk of electrode 11 breakage, and improves the cycle performance of the battery cell 7.

[0171] In some embodiments, the battery cell 7 includes a plurality of patches 40, which are spaced apart.

[0172] Multiple patches 40 can be set at equal intervals or unequal intervals.

[0173] Given a consistent total area, attaching multiple smaller patches 40, compared to attaching a single larger patch, can result in a more uniform resistance to the electrode assembly 10 when the battery cell 7 is subjected to external impact, reducing the risk of electrode assembly 10 shifting. Furthermore, the edge 40b of each patch 40 can form a stepped structure protruding from the first outer surface 30a, which can also increase the resistance to movement of the patch 40 when the battery cell 7 is subjected to external impact.

[0174] In some embodiments, a plurality of patches 40 are spaced apart along the circumferential direction W of the electrode assembly 10. The plurality of patches 40 may be spaced equally or unequally apart along the circumferential direction W of the electrode assembly 10.

[0175] Figure 8 A schematic diagram of the patch provided in some embodiments of this application in a flattened state; Figure 9 for Figure 8 The diagram shows a cross-sectional view of the patch.

[0176] like Figure 8 and Figure 9 As shown, in some embodiments, the patch 40 includes a base layer 41 and an adhesive layer 42, the adhesive layer 42 being disposed between the first outer surface 30a and the base layer 41 and bonding the first outer surface 30a and the base layer 41. The base layer 41 includes a second outer surface 40a.

[0177] By providing the adhesive layer 42, the base layer 41 can be bonded to the first outer surface 30a, thereby reducing the relative slippage between the base layer 41 and the insulating component 30 when the battery cell 7 is subjected to external impact. The base layer 41 can also separate the adhesive layer 42 from the outer casing 20, thereby reducing the risk of frictional wear on the adhesive layer 42.

[0178] In some embodiments, the insulating element 30 is adhesive tape. Optionally, the insulating element 30 is blue adhesive tape.

[0179] In some embodiments, patch 40 may be adhesive tape. Optionally, patch 40 may be corrugated tape.

[0180] In some embodiments, patch 40 is rectangular in its flattened state.

[0181] In some embodiments, the second outer surface 40a is provided with a plurality of protrusions 43 spaced apart.

[0182] In this embodiment, a protrusion 43 is provided on the second outer surface 40a to increase the surface roughness of the second outer surface 40a. This increases the frictional resistance of the patch 40 when the battery cell 7 is subjected to external impact, reduces the slippage of the electrode assembly 10 within the housing 20, reduces the risk of battery cell 7 failure, and improves the reliability of the battery cell 7.

[0183] For example, the second outer surface 40a includes the exposed surface of the protrusion 43.

[0184] In some embodiments, the base layer 41 includes a plurality of protrusions 43.

[0185] In some embodiments, the protrusion 43 is curved. As an example, the protrusion 43 is corrugated.

[0186] When the battery cell 7 is subjected to external impact, the curved protrusion 43 can generate greater frictional resistance in multiple directions, thereby effectively reducing the slippage of the electrode assembly 10 within the housing 20, reducing the risk of battery cell 7 failure, and improving the reliability of battery cell 7.

[0187] In some embodiments, the two ends of the protrusion 43 extend to the two opposite edges 40b of the second outer surface 40a, respectively.

[0188] In this embodiment, the protrusion 43 has a large extension length, which can increase the contact area between the protrusion 43 and the housing 20. When the battery cell 7 is subjected to external impact, the frictional resistance is increased, thereby effectively reducing the slippage of the electrode assembly 10 in the housing 20.

[0189] In some embodiments, a plurality of protrusions 43 are spaced apart along a first direction X, and the two ends of each protrusion 43 extend to two edges 40b of the second outer surface 40a along the second direction Y, respectively, and the first direction X may be perpendicular to the second direction Y.

[0190] As an example, in the flattened state, one of the first direction X and the second direction Y is the length direction of patch 40, and the other is the width direction of patch 40.

[0191] In alternative embodiments, patch 40 may be subjected to other treatments to increase the surface roughness of the second outer surface 40a.

[0192] For example, in some examples, the surface roughness of the second outer surface 40a can be increased by creating recesses in the second outer surface 40a. In other embodiments, the surface roughness of the second outer surface 40a can be increased by spraying particles onto the patch 40.

[0193] Figure 10 The diagram shows the structure of the electrode assembly, insulating component, and patch of a battery cell provided in other embodiments of this application.

[0194] like Figure 10 As shown, in some embodiments, multiple patches 40 are spaced apart along a direction perpendicular to the circumferential W.

[0195] As an example, the electrode assembly 10 has a wound structure, and the winding axis Z of the electrode assembly 10 is perpendicular to the circumferential direction W of the electrode assembly 10. Multiple patches 40 are arranged at intervals along the winding axis Z.

[0196] Figure 11 This is a schematic diagram of the electrode assembly, insulating component, and patch of a battery cell provided in some embodiments of this application.

[0197] like Figure 11 As shown, in some embodiments, multiple patches 40 are spaced apart along the winding axis Z to form patch columns, and multiple patch columns are spaced apart along the circumferential direction W of the electrode assembly 10. Optionally, when the insulating member 30 is in a flattened state, the multiple patches 40 are arranged in a rectangular array on the first outer surface 30a.

[0198] According to some embodiments of this application, this application also provides a battery comprising multiple battery cells of any of the above embodiments.

[0199] According to some embodiments of this application, this application also provides an electrical device, including a battery cell from any of the above embodiments, wherein the battery cell is used to provide electrical energy to the electrical device. The electrical device can be any of the aforementioned devices or systems that utilize battery cells.

[0200] Reference Figures 4 to 7One embodiment of this application provides a battery cell 7, which includes a housing 20, an electrode assembly 10, an insulating component 30, and a plurality of patches 40.

[0201] The electrode assembly 10 is housed within the housing 20 and includes an electrode 11 and a spacer 12, which are wound together to form a cylindrical wound structure. An insulating member 30 surrounds the electrode assembly 10 and is attached to the outer peripheral surface 10a of the electrode assembly 10, and the insulating member 30 covers the wound end 12a of the spacer 12.

[0202] The insulating member 30 has a first outer surface 30a on the side facing away from the electrode assembly 10. A plurality of patches 40 are attached to the first outer surface 30a and spaced apart. The patches 40 have a second outer surface 40a on the side facing away from the insulating member 30, and at least a portion of the surface roughness of the second outer surface 40a is greater than the surface roughness of the first outer surface 30a.

[0203] In some embodiments, the patch 40 is a corrugated tape, and the second outer surface 40a is provided with a plurality of corrugated protrusions 43.

[0204] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, include: shell; Electrode assembly, housed within the housing; An insulating element is disposed on the outside of the electrode assembly, the insulating element having a first outer surface on the side opposite to the electrode assembly; as well as A patch is attached to and covers a portion of the first outer surface, the patch having a second outer surface on a side opposite to the insulator, the surface roughness of at least a portion of the second outer surface being greater than the surface roughness of the first outer surface.

2. The battery cell according to claim 1, characterized in that, The patch includes a base layer and an adhesive layer, wherein the adhesive layer is disposed between the first outer surface and the base layer and bonds the first outer surface and the base layer; The base layer includes the second outer surface.

3. The battery cell according to claim 1, characterized in that, The second outer surface is provided with a plurality of protrusions spaced apart.

4. The battery cell according to claim 3, characterized in that, The protrusion is curved.

5. The battery cell according to claim 3, characterized in that, The two ends of the protrusion extend to the two opposite edges of the second outer surface, respectively.

6. The battery cell according to any one of claims 1-5, characterized in that, It includes multiple patches, and the multiple patches are spaced apart.

7. The battery cell according to claim 6, characterized in that, Multiple patches are arranged at circumferential intervals along the electrode assembly; and / or The plurality of patches are spaced apart along a direction perpendicular to the circumferential direction.

8. The battery cell according to any one of claims 1-5, characterized in that, The surface roughness of the second outer surface is greater than or equal to 10 μm.

9. The battery cell according to claim 8, characterized in that, The surface roughness of the second outer surface is Ra, which satisfies: 10μm≤Ra≤3600μm.

10. The battery cell according to claim 9, characterized in that, 300μm≤Ra≤600μm.

11. The battery cell according to any one of claims 1-5, characterized in that, The total area of ​​the first outer surface is S1, and the area of ​​the region of the first outer surface covered by the patch is S2, where 0.02 ≤ S2 / S1 ≤ 0.

5.

12. The battery cell according to any one of claims 1-5, characterized in that, The electrode assembly includes wound electrode sheets and insulating components; The insulating element is attached to the insulating element and is used to secure the wound end of the insulating element.

13. The battery cell according to claim 12, characterized in that, The insulating element surrounds the electrode assembly.

14. The battery cell according to claim 12, characterized in that, In the thickness direction of the patch, the patch does not overlap with the winding end of the electrode.

15. A battery, characterized in that, It includes multiple battery cells according to any one of claims 1-14.

16. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1-14, the battery cell being used to provide electrical energy.

Images