Cylindrical cell, battery device, and electric device

Abstract

The present application provides a cylindrical cell, a battery device, and an electric device. The cylindrical cell comprises a casing and an electrode assembly; the electrode assembly is accommodated in the casing, and comprises a first electrode sheet and a second electrode sheet which have opposite polarities; and the first electrode sheet and the second electrode sheet are wound in a winding direction. The first electrode sheet comprises an electrode sheet body and a reinforcing coating; the electrode sheet body has a first area and a second area which are arranged adjacent to each other in the winding direction; the first area extends from a winding starting end of the electrode sheet body, and is provided with the reinforcing coating; and no reinforcing coating is provided in the second area. In the embodiments of the present application, the risk of deformation collapse of the first electrode sheet at a position near a central hole can be reduced without additionally adding other components to the interior of the cylindrical cell, thereby improving the use reliability of the cylindrical cell.

Description

Cylindrical battery cells, battery packs and electrical devices Cross-reference to related applications

[0001] This application claims priority to Chinese patent application 202411181895.3, filed on August 27, 2024, entitled “Cylindrical Battery Cell, Battery Device and Power Consumption Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and in particular to a cylindrical battery cell, a battery device, and an electrical device. Background Technology

[0003] 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. Battery cells can include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and rechargeable alkaline zinc-manganese battery cells, among others.

[0004] However, during the use of a battery cell, the electrode assembly may deform due to factors such as stress, affecting the normal use of the battery cell. Summary of the Invention

[0005] In view of the above problems, this application provides a cylindrical battery cell, a battery device, and an electrical device, which can improve the reliability of cylindrical battery cells.

[0006] On one hand, embodiments of this application provide a cylindrical battery cell, which includes a housing and an electrode assembly. The electrode assembly is housed within the housing and includes a first electrode and a second electrode with opposite polarities, which are wound along a winding direction. The first electrode includes an electrode body and a reinforcing coating. The electrode body has a first region and a second region arranged adjacent to each other along the winding direction. The first region extends from the winding start end of the electrode body and is provided with a reinforcing coating, while the second region is not provided with a reinforcing coating.

[0007] In the above solution, by providing a reinforcing coating in the first region, the yield strength of the first electrode in the first region can be enhanced, thus reducing the risk of deformation of the first electrode in the first region. This reduces the risk of deformation and collapse of the first electrode near the central hole without adding any additional components inside the cylindrical battery cell, thereby improving the reliability of the cylindrical battery cell.

[0008] In some embodiments, along the axial direction of the cylindrical battery cell, the electrode body includes a main body and a tab, the main body having a reinforcing coating in a first region, and the tab not having a reinforcing coating in the first region.

[0009] In the above scheme, the reinforcing coating is placed on the main body in the first region, while the tab is not reinforced in the first region. This reduces the risk of deformation of the main body near the central hole and does not affect the structure of the tab in the first region. This allows the structure of the tab in the first region to be smoothed or flattened along with the structure in the second region, and the tab to have the same or similar degree of deformation in the first and second regions. This improves the density of the tab, meets the welding requirements of the tab, and improves the yield of cylindrical battery cells.

[0010] In some embodiments, the reinforcing coating covers the structure of the main body within the first region, or the reinforcing coating includes a plurality of reinforcing strips spaced apart.

[0011] In the above scheme, the reinforcing coating can be set into different shapes and structures according to different actual needs, and there can also be various relative positional relationships between the reinforcing coating and the main body. Based on this, by adjusting the size and shape of the reinforcing coating or its relative positional relationship with the main body, the reinforcement effect at different locations can be achieved, which has strong flexibility and practicality.

[0012] In some embodiments, the reinforcing coating is disposed on both sides of the electrode body in its thickness direction.

[0013] In the above scheme, the structures corresponding to the two parts of the reinforcing coating located on different sides of the electrode body in the thickness direction can be the same or different. By distributing the reinforcing coating on both sides of the electrode body in the thickness direction, the risk of deformation and collapse of the electrode body in the thickness direction can be reduced, which helps to further reduce the risk of deformation and collapse of the first electrode near the central hole and improve the reliability of the cylindrical battery cell.

[0014] In some embodiments, the reinforcing coating is flush with the starting end of the winding of the electrode body.

[0015] In the above scheme, considering that the winding start end is the structure on the electrode body closest to the central hole, it is also the structure most prone to deformation and collapse towards the central hole. Based on this, by setting the reinforcing coating to be flush with the winding start end of the electrode body, the support strength of the first electrode at the winding start end can be improved, further mitigating the problem of collapse at the central hole.

[0016] In some embodiments, the yield strength of the reinforced coating is P1, where P1 satisfies 30 MPa ≤ P1 ≤ 400 MPa.

[0017] In the above scheme, by setting the yield strength P1 of the reinforcing coating to be no less than 30 MPa, the reinforcing coating itself can have a certain strength, thereby reducing the risk of deformation and collapse in the area where the reinforcing coating is located. At the same time, the yield strength P1 of the reinforcing coating is set to be no more than 400 MPa, so that the area where the reinforcing coating is located can still curl to a certain extent, thereby meeting the winding requirements of the first electrode.

[0018] In some embodiments, the reinforcing coating includes an insulating material.

[0019] In the above solution, by including insulating material in the reinforcing coating, the reinforcing coating can provide support strength while also serving as insulation, thereby reducing leakage problems caused by contact between the reinforcing coating and components such as the casing, and improving the reliability of the battery cell.

[0020] In some embodiments, the reinforcing coating includes at least one of hard carbon, graphite, soft carbon, silicon carbon, silicon oxide, conductive carbon, and conductive carbon nanotubes; and / or, the reinforcing coating includes at least one of olefin-ester copolymers, such as ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, and ethylene-methacrylate copolymer.

[0021] In the above scheme, by setting the reinforcing coating to include at least one of hard carbon, graphite, soft carbon, silicon carbon, silicon oxide, conductive carbon, and conductive carbon nanotubes, the reinforcing coating can have good adhesion and support strength, and can be highly compatible with the preparation of the first electrode sheet without the need for additional equipment and processes, thus having strong practicality.

[0022] Alternatively, by including at least one of olefin-ester copolymers, such as ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, and ethylene-methacrylate copolymer, the reinforcing coating can include a polymer, which can improve the supporting strength while reducing the impact on the overall weight of the first electrode, thus improving the energy density of the cylindrical battery cell.

[0023] In some embodiments, in the winding direction, the size of the reinforcing coating is L1, which satisfies: 1mm≤L1≤100mm; and / or, in the thickness direction of the electrode body, the size of the reinforcing coating is L2, which satisfies: 4μm≤L2≤200μm.

[0024] In the above scheme, by setting the size L1 of the reinforcing coating to be no less than 1 mm, the reinforcing coating can have a certain coating area, allowing it to provide better support strength for the first electrode. Simultaneously, the size L1 of the reinforcing coating is set to be no greater than 100 mm to reduce the adverse effects of the reinforcing coating on the energy density of the cylindrical battery cell and improve its capacity.

[0025] Similarly, by setting the size L2 of the reinforcing coating to be no less than 4 μm, the reinforcing coating can have a certain thickness, allowing it to provide better support strength for the first electrode. At the same time, the size L2 of the reinforcing coating is set to be no greater than 200 μm to reduce the adverse effects of the reinforcing coating on the energy density of the cylindrical battery cell and to improve the capacity of the cylindrical battery cell.

[0026] In some embodiments, the density of the reinforced coating is R, where R satisfies: 0.65 g / cc ≤ R ≤ 3.7 g / cc.

[0027] In the above scheme, by setting the density R of the reinforcing coating to not less than 0.65 g / cc, the reinforcing coating can possess a certain yield strength, thereby helping to reduce the risk of deformation and collapse of the first electrode in local locations and improving its reliability. Simultaneously, by setting the density R of the reinforcing coating to not more than 3.7 g / cc, the first electrode can still have a certain degree of bending at the location with the reinforcing coating, thus meeting the corresponding winding requirements of the first electrode and demonstrating strong practicality.

[0028] In some embodiments, the bonding strength of the reinforcing coating is F, where F satisfies: 2N / m≤F≤100N / m.

[0029] In the above scheme, by setting the adhesion strength F of the reinforcing coating to be no less than 2 N / m, a certain degree of adhesion can be achieved between the reinforcing coating and the electrode body. This reduces the risk of the reinforcing coating detaching from the electrode body under complex operating conditions, thereby further improving the reliability of the cylindrical battery cell. Simultaneously, by setting the adhesion strength F to be no greater than 100 N / m, the adverse effects on the charging and discharging process of the cylindrical battery cell caused by excessively strong adhesion between the reinforcing coating and the electrode body are reduced.

[0030] In some embodiments, in the winding direction, the size ratio of the first region to the second region is A, where A satisfies: 0.5% ≤ A ≤ 10%.

[0031] In the above scheme, by setting A to no less than 0.5%, the electrode body can receive the support and reinforcement effect of the reinforcing coating within a certain area, thereby reducing the risk of deformation and collapse of the first electrode towards the central hole and improving the reliability of the cylindrical battery cell. Simultaneously, setting A to no more than 10% reduces the adverse effects of the reinforcing coating on the energy density of the cylindrical battery cell, contributing to improved performance.

[0032] In some embodiments, in the winding direction, the electrode body further has a third region located on the side of the second region opposite to the first region, the third region extending from the winding end of the electrode body and having a reinforcing coating.

[0033] In the above scheme, a reinforcing coating is added to the third region, thereby separating the third region from the second region. In the process of forming the electrode assembly, the reinforcing coating in the third region can be used to position the winding end of the electrode body, realize fixed-length cutting during winding, and improve the yield of cylindrical battery cells.

[0034] In some embodiments, the innermost winding of the first electrode is located at the innermost winding of the second electrode.

[0035] In the above scheme, since the innermost winding of the first electrode is located closer to the center hole than the innermost winding of the second electrode, deformation and collapse of the first electrode are more likely to adversely affect the center hole. Therefore, by providing a reinforcing coating in the first region of the first electrode, the risk of deformation and collapse of the first electrode towards the center hole is reduced, improving the reliability of the cylindrical battery cell.

[0036] In some embodiments, the first electrode is a negative electrode and the second electrode is a positive electrode.

[0037] In the above scheme, the negative electrode sheet, i.e. the first electrode sheet, was adjusted and a reinforcing coating was added to the first electrode sheet. The reinforcing coating reduces the risk of deformation and collapse of the first electrode sheet near the center hole, thereby improving the reliability of the cylindrical battery cell.

[0038] In some embodiments, the electrode body includes a first current collector and a base coating layer located on one side of the first current collector, with a reinforcing coating layer located on the side of the base coating layer opposite to the first current collector. The second electrode includes a second current collector and an active material layer located on one side of the second current collector, the thickness of the active material layer being greater than the thickness of the base coating layer.

[0039] In the above scheme, the first electrode was adjusted and a reinforcing coating was added to the first electrode. The reinforcing coating reduces the risk of deformation and collapse of the first electrode near the center hole, thereby improving the reliability of the cylindrical battery cell.

[0040] In some embodiments, the cylindrical battery cell is a metal battery cell.

[0041] In the above scheme, the first electrode was adjusted and a reinforcing coating was added to the first electrode. The reinforcing coating reduces the risk of deformation and collapse of the first electrode near the center hole, thereby improving the reliability of the cylindrical battery cell.

[0042] Secondly, embodiments of this application provide a battery device, which includes the cylindrical battery cell in any of the foregoing embodiments.

[0043] Thirdly, the embodiments of this application provide an electrical device, which includes a cylindrical battery cell and a battery device as described in any of the foregoing embodiments. The cylindrical battery cell or the battery device is used to provide electrical energy.

[0044] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 is a structural schematic diagram of a vehicle provided in an embodiment of this application;

[0047] Figure 2 is an exploded structural diagram of a battery device provided in an embodiment of this application;

[0048] Figure 3 is a schematic diagram of the internal structure of a battery module provided in an embodiment of this application;

[0049] Figure 4 is a schematic diagram of the structure of a battery cell provided in an embodiment of this application;

[0050] Figure 5 is a schematic diagram of the structure of an electrode assembly in a battery cell provided in an embodiment of this application;

[0051] Figure 6 is a schematic diagram of the structure of the first electrode in a battery cell in an unfolded state according to an embodiment of this application;

[0052] Figure 7 is a schematic diagram of the structure of the first electrode in a battery cell in an unfolded state according to an embodiment of this application;

[0053] Figure 8 is a schematic diagram of the structure of the first electrode in a battery cell in an unfolded state according to an embodiment of this application;

[0054] Figure 9 is a schematic diagram of the structure of the first electrode in the unfolded state of a battery cell according to an embodiment of this application;

[0055] Figure 10 is a schematic diagram of the structure of the first electrode in the unfolded state of a battery cell according to an embodiment of this application;

[0056] Figure 11 is a schematic diagram of the structure of the first electrode in the unfolded state of a battery cell according to an embodiment of this application;

[0057] Figure 12 is a schematic diagram of the structure of the second electrode in a battery cell in an unfolded state according to an embodiment of this application. Detailed Implementation

[0058] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein 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 specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0060] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0061] In this document, the term "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 throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0062] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0063] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0064] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0065] In the description of the embodiments 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, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0066] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0067] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0068] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0069] 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.

[0070] 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.

[0071] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the positive and negative electrodes. 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.

[0072] 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.

[0073] 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.

[0074] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0075] 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 positive electrode active materials for batteries 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 manganese iron phosphate, and lithium manganese iron phosphate and carbon composites. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also abbreviated as NCM333), LiNi0.5Co0.2Mn0.3O2 (also abbreviated as NCM523), LiNi0.5Co The following are included: 0.25Mn0.25O2 (also known as NCM211), LiNi0.6Co0.2Mn0.2O2 (also known as NCM622), LiNi0.8Co0.1Mn0.1O2 (also known as NCM811), lithium nickel cobalt aluminum oxides (such as LiNi0.8Co0.15Al0.05O2), and their modified compounds. Modified compounds refer to substances obtained by doping or coating, etc., based on the above-mentioned materials.

[0076] 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, a positive electrode active material is filled and / or deposited within the foamed metal.

[0077] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0078] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0079] 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.

[0080] 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.

[0081] 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 negative electrode active materials for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0082] In some embodiments, the negative 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 negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0083] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0084] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0085] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0086] 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.

[0087] 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 single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0088] 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.

[0089] 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.

[0090] Liquid electrolytes include electrolyte salts and solvents.

[0091] 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.

[0092] 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.

[0093] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell, such as additives that improve the overcharge / fast charge performance of the battery cell, additives that improve the high-temperature performance of the battery cell, and additives that improve the low-temperature performance of the battery cell.

[0094] The gel electrolyte includes a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0095] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0096] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0097] 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.

[0098] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0099] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0100] 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.

[0101] In some embodiments, the battery cell may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the casing may be a sealed structure or a non-sealed structure. As an example, when the casing is a non-sealed structure, the casing serves to protect the electrode assembly, and a sealing bag is included between the casing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.

[0102] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab, or it can be indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0103] In some embodiments, a current collector may be provided inside the housing, and the electrode assembly may be electrically connected to the housing or electrode terminals provided on the housing through the current collector.

[0104] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0105] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0106] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0107] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0108] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0109] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0110] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0111] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0112] 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.

[0113] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0114] For cylindrical battery cells, the positive and negative electrode plates in the electrode assembly are wound into a spiral structure, and a central hole is formed at the starting end of the winding. During the use of a cylindrical battery cell, the electrode plates are prone to collapse into the central hole, affecting the reliability of the battery cell. In related technologies, a support structure can be provided at the central hole. However, due to the influence of the support structure itself, such as its volume and weight, the presence of the support structure will adversely affect the capacity and energy density of the cylindrical battery cell.

[0115] Based on the above-mentioned technical problems, this application provides a cylindrical battery cell, a battery device, and an electrical device. By providing a reinforcing coating, the first region near the central hole in the first electrode is locally reinforced, thereby reducing the risk of the first electrode collapsing into the central hole and improving the reliability of the cylindrical battery cell.

[0116] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use individual battery cells, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0117] The cylindrical battery cells described in this application are not limited to the electrical devices described above, but for the sake of brevity, the following embodiments are all illustrated using electric vehicles as an example.

[0118] Please refer to Figure 1, which is a simplified schematic diagram of a vehicle 1000 provided in an embodiment of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 can be installed inside the vehicle 1000; specifically, for example, the battery device 100 can be installed at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 100 may also include a controller 200 and a motor 300. The controller 200, for example, is used to control the battery to supply power to the motor 300. The battery device 100 can be used for starting the vehicle 1000, navigation, etc. Of course, the battery device 100 can also be used to drive the vehicle 1000, replacing or partially replacing gasoline or natural gas to provide propulsion for the vehicle 1000.

[0119] Figure 2 is an exploded view of a battery device provided in some embodiments of this application. As shown in Figure 2, the battery device 100 includes a housing 400 and individual battery cells (not shown in the figure), with the individual battery cells housed within the housing 400.

[0120] The housing 400 is used to accommodate individual battery cells, and the housing 400 can have various structures. In some embodiments, the housing 400 may include a first housing portion 41 and a second housing portion 42, which overlap each other, and together define a receiving portion for accommodating the individual battery cells. The second housing portion 42 may be a hollow structure with one end open, and the first housing portion 41 may be a plate-like structure, with the first housing portion 41 covering the open side of the second housing portion 42 to form a housing with a receiving portion; alternatively, both the first housing portion 41 and the second housing portion 42 may be hollow structures with one side open, with the open side of the first housing portion 41 covering the open side of the second housing portion 42 to form a housing 400 with a receiving portion. Of course, the first housing portion 41 and the second housing portion 42 can have various shapes, such as cylinders, cuboids, etc.

[0121] In the battery device 100, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells are connected in both series and parallel configurations. Multiple battery cells can be directly connected in series, in parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells is housed within the housing 400. Alternatively, multiple battery cells can first be connected in series, in parallel, or in a mixed configuration to form a battery module 600, and then the multiple battery modules 600 can be connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 400.

[0122] Figure 3 is a schematic diagram of the structure of the battery module 600 shown in Figure 2. In some embodiments, as shown in Figure 3, there are multiple cylindrical battery cells 500. These multiple cylindrical battery cells 500 are first connected in series, parallel, or in a mixed connection to form the battery module 600. The multiple battery modules 600 are then connected in series, parallel, or in a mixed connection to form a whole, which is housed in a casing.

[0123] The structure of the cylindrical battery cell will now be described with reference to the accompanying drawings.

[0124] Please refer to Figures 4 to 7. The cylindrical battery cell 500 includes a housing 10 and an electrode assembly 20, which is housed within the housing 10. The electrode assembly 20 includes a first electrode 21 and a second electrode 22 with opposite polarities, which are wound along the winding direction Z. The first electrode 21 includes an electrode body 211 and a reinforcing coating 212. The electrode body 211 has a first region A1 and a second region A2 arranged adjacent to each other along the winding direction Z. The first region A1 extends from the winding start end D1 of the electrode body 211 and is provided with the reinforcing coating 212, while the second region A2 is not provided with the reinforcing coating 212.

[0125] The cylindrical battery cell 500 is a device for providing electrical energy. The cylindrical battery cell 500 has a housing 10, which is cylindrical and hollow, and protects other components located inside it. Specifically, the electrode assembly 20 is disposed inside the housing 10, and the housing 10 protects the electrode assembly 20. The electrode assembly 20 is the core component for storing or releasing electrical energy in the cylindrical battery cell 500.

[0126] Typically, the size and shape of the outer casing 10 are adapted to the size and shape of the electrode assembly 20. Since the outer casing 10 in the cylindrical battery cell 500 is cylindrical, the electrode assembly 20 can also be cylindrical. Further, the electrode assembly 20 has a cylindrical wound structure, with the first electrode 21 and the second electrode 22 wound together to form this cylindrical wound structure. The first electrode 21 and the second electrode 22 are electrode structures with different polarities in the electrode assembly 20. For example, the first electrode 21 can be the positive electrode in the electrode assembly 20, in which case the second electrode 22 is the negative electrode. Alternatively, the first electrode 21 can also be the negative electrode in the electrode assembly 20, in which case the second electrode 22 is the positive electrode.

[0127] It should be noted that the cylindrical battery cell 500 provided in this application embodiment has various forms. For example, the cylindrical battery cell 500 can be one of a lithium-ion battery, a sodium-ion battery, and a sodium-lithium-ion battery. In this case, one of the first electrode 21 and the second electrode 22 includes a positive current collector and a positive active material located on the surface of at least one of the positive current collectors, and the other includes a negative current collector and a negative active material located on the surface of at least one of the negative current collectors. Alternatively, the cylindrical battery cell 500 can also be one of a lithium metal battery and a sodium metal battery. In this case, one of the first electrode 21 and the second electrode 22 includes a positive current collector and a positive active material located on the surface of at least one of the positive current collectors, and the other includes a negative current collector but does not include a negative active material.

[0128] The following embodiment of this application will briefly describe the formation of the electrode assembly 20. In the initial state, both the first electrode 21 and the second electrode 22 are in a flat, unfolded state and their cross-sectional shape can be rectangular. Along the length of the rectangle, both the first electrode 21 and the second electrode 22 have opposing winding start ends D1 and winding end ends D2. During the winding process, the first electrode 21 and the second electrode 22 are stacked and gradually wound from the winding start end D1 toward the winding end end D2, thereby forming a cylindrical electrode assembly 20.

[0129] At the center of the electrode assembly 20, that is, near the winding start end D1, the electrode assembly 20 will have a central hole H. Since the central hole H itself is a hollow structure, during the use of the cylindrical battery cell 500, due to the influence of external forces and other factors, part of the structure of the first electrode 21 at the winding start end D1 is prone to collapse into the central hole H, thereby affecting the reliability of the cylindrical battery cell 500.

[0130] Therefore, this application adjusts the structure of the first electrode 21 to reduce the risk of the first electrode 21 collapsing towards the central hole H. Specifically, the first electrode 21 includes an electrode body 211 and a reinforcing coating 212. The electrode body 211 is the core component of the first electrode 21. For example, if the first electrode 21 is a positive electrode, the electrode body 211 may include a positive current collector and a positive active material. If the first electrode 21 is a negative electrode, the electrode body 211 may only include a negative current collector, or the electrode body 211 may simultaneously include a negative current collector and a negative active material.

[0131] The reinforcing coating 212 is a layer structure that enhances the yield strength of the first electrode 21 at local locations. Here, "yield strength" refers to the stress that a structure resists minute plastic deformation. A higher yield strength indicates a stronger ability to resist stress and less susceptibility to deformation. The reinforcing coating 212 can be applied only to one side of the electrode body 211 along its thickness direction Y, or it can be applied to both sides of the electrode body 211 along its thickness direction Y.

[0132] The reinforcing coating 212 can be made of various materials; for example, it can be made of an insulating material or a conductive material. Furthermore, the reinforcing coating 212 may include materials with at least a partial structure identical to that of the electrode body 211, or the material composition of the reinforcing coating 212 may be completely different from that of the electrode body 211. The thickness of the reinforcing coating 212 can be greater than or less than the thickness of the electrode body 211.

[0133] Of course, the reinforcing coating 212 can also have various shapes and sizes. For example, the reinforcing coating 212 can be in the form of blocks, strips, or sheets, or be regular or irregular shapes. The thickness of the reinforcing coating 212 can be greater than, less than, or equal to the thickness of the electrode body 211, as long as the yield strength of the first electrode 21 at the location where the reinforcing coating 212 is provided is greater than its yield strength at the location where the reinforcing coating 212 is not provided.

[0134] The electrode body 211 has a first region A1 and a second region A2 adjacent to each other along the winding direction Z. The first region A1 extends from the winding start end D1 of the electrode body 211, that is, the first region A1 is the region that includes the winding start end D1 and is closer to the center hole H than the second region A2. The reinforcing coating 212 is disposed in the first region A1 but not in the second region A2. That is, the first region A1 is the region on the first electrode 21 that is relatively close to the center hole H and has the reinforcing coating 212, while the second region A2 is the region on the first electrode 21 that does not have the reinforcing coating 212.

[0135] In this embodiment, by providing a reinforcing coating 212 at the first region A1, the yield strength of the first electrode 21 at the first region A1 can be enhanced, thereby reducing the risk of deformation of the first electrode 21 at the first region A1. This reduces the risk of deformation and collapse of the first electrode 21 near the central hole H without adding any additional components inside the cylindrical battery cell 500, thus improving the reliability of the cylindrical battery cell 500.

[0136] It should be noted that the reinforcing coating 212 can have various coating methods relative to the first region A1. For example, the electrode body 211 may include a main body portion B1 and a tab portion B2. Taking the electrode body 211 having an active material as an example, the main body portion B1 can be a structure on the electrode body 211 with an active material, while the tab portion B2 is a structure on the electrode body 211 without an active material. Alternatively, the main body portion B1 can be a structure on the electrode body 211 used for reacting with the electrolyte, while the tab portion B2 is a structure on the electrode body 211 used for electrically connecting to the electrode terminals to conduct current from the electrode assembly 20.

[0137] Based on this, the reinforcing coating 212 can completely cover the first region A1, or the reinforcing coating 212 can be provided only in a portion of the first region A1. Furthermore, the reinforcing coating 212 can be provided on both the main body B1 and the tab B2 of the first region A1, or the reinforcing coating 212 can be provided only on the main body B1 of the first region A1, while the tab B2 of the first region A1 is not provided with the reinforcing coating 212.

[0138] Furthermore, the structure of the second electrode 22 can be the same as or different from that of the first electrode 21. Optionally, the second electrode 22 also includes a reinforcing coating 212. The second electrode 22 has a fourth region and a fifth region arranged adjacent to each other along the winding direction Z. The fourth region extends from the winding start end D1 and is provided with the reinforcing coating 212, while the fifth region is not provided with the reinforcing coating 212.

[0139] In some embodiments, as shown in Figures 4 to 7, along the axial direction X of the cylindrical battery cell 500, the electrode body 211 includes a main body portion B1 and an electrode tab portion B2. The main body portion B1 is provided with a reinforcing coating 212 in the first region A1, while the electrode tab portion B2 is not provided with a reinforcing coating 212 in the first region A1.

[0140] The main body B1 and the tab B2 are arranged adjacent to each other in the axial direction X. The "axial direction X" mentioned here refers to the direction of the central axis of the cylindrical battery cell 500, wherein the central hole H can extend along the axial direction X.

[0141] During the fabrication of the cylindrical battery cell 500, the tab B2 is typically electrically connected to the electrode terminals on the casing 10. Before being electrically connected to the electrode terminals, the tab B2 needs to be flattened or smoothed to achieve a predetermined density to meet the strength required for welding. Here, "density" refers to the ratio of the mass of the solid material portion of the structure to its total volume.

[0142] Furthermore, considering that if the tab B2 is provided with a reinforcing coating 212 in the first region A1, the tab B2 in the first region A1 is not easy to be flattened or smoothed out, which may have an adverse effect on the overall density of the tab B2, and may also cause the tab B2 in the first region A1 to contact and interfere with components such as the outer casing 10, which is not conducive to the normal use of the battery cell.

[0143] Therefore, in this embodiment, the reinforcing coating 212 is provided on the main body B1 in the first region A1, while the tab B2 is not provided with the reinforcing coating 212 in the first region A1. This can reduce the risk of deformation of the main body B1 near the central hole H, and also avoid affecting the structure of the tab B2 in the first region A1. This allows the structure of the tab B2 in the first region A1 to be smoothed or flattened along with the structure in the second region A2, and makes the tab B2 have the same or similar degree of deformation in the first region A1 and the second region A2. This improves the density of the tab B2, meets the welding requirements of the tab B2, and improves the yield of the cylindrical battery cell 500.

[0144] In some embodiments, as shown in Figures 6 to 9, the reinforcing coating 212 covers the structure of the main body portion B1 within the first region A1, or the reinforcing coating 212 includes a plurality of reinforcing strips 2121 spaced apart.

[0145] The reinforcing coating 212 can have various sizes and positional relationships relative to the main body B1. For example, the reinforcing coating 212 can completely cover the main body B1 located in the first region A1. In this way, the reinforcing coating 212 can comprehensively strengthen the main body B1, thereby further reducing the risk of deformation of the main body B1 in the first region A1 and improving reliability.

[0146] Alternatively, the reinforcing coating 212 may include multiple reinforcing strips 2121, with adjacent reinforcing strips 2121 spaced apart from each other. Each reinforcing strip 2121 can have various shapes; for example, it can be a regular elongated strip or an irregular strip structure. The shapes and dimensions of different reinforcing strips 2121 can be the same or different. Furthermore, different reinforcing strips 2121 can have various positional relationships. For example, a single reinforcing strip 2121 can extend along the winding direction Z, and multiple reinforcing strips 2121 can be spaced apart along the axial direction X. Alternatively, a single reinforcing strip 2121 can also extend along the axial direction X, and multiple reinforcing strips 2121 can be spaced apart along the winding direction Z. Alternatively, a single reinforcing strip 2121 can also extend along directions other than the winding direction Z and the axial direction X.

[0147] In this embodiment, the reinforcing coating 212 can be configured with different shapes and structures according to different actual needs, and the reinforcing coating 212 and the main body B1 can also have various relative positional relationships. Based on this, by adjusting the size and shape of the reinforcing coating 212 or its relative positional relationship with the main body B1, the reinforcing effect at different positions can be achieved, which has strong flexibility and practicality.

[0148] It should be noted that, in addition to the two structural forms mentioned above, the reinforcing coating 212 can also have other structural forms. For example, the reinforcing coating 212 can also include multiple block structures, and the multiple block structures can be arranged in an array along the winding direction Z and the axial direction X.

[0149] In some embodiments, as shown in Figures 4 to 7, the reinforcing coating 212 is disposed on both sides of the electrode body 211 in the thickness direction Y.

[0150] In this embodiment, the structures corresponding to the two parts of the reinforcing coating 212 located on different sides of the electrode body 211 in the thickness direction Y can be the same or different. By distributing the reinforcing coating 212 on both sides of the electrode body 211 in its own thickness direction Y, the risk of deformation and collapse of the electrode body 211 in its own thickness direction Y can be reduced, which helps to further reduce the risk of deformation and collapse of the first electrode 21 near the central hole H, and improves the reliability of the cylindrical battery cell 500.

[0151] In some embodiments, the reinforcing coating 212 is flush with the winding start end D1 of the electrode body 211.

[0152] One end of the reinforcing coating 212 near the central hole H can be attached to the winding start end D1 of the electrode body 211. The reinforcing coating 212 and the winding start end D1 of the electrode body 211 can have various positional relationships. For example, if the reinforcing coating 212 is a planar structure, it can completely cover the winding start end D1 of the electrode body 211. Alternatively, if the reinforcing coating 212 is a strip-shaped structure extending along the winding direction Z, one end of each of the multiple strip-shaped structures will be attached to the winding start end D1 of the electrode body 211. Or, if the reinforcing coating 212 is a strip-shaped structure extending along the axial direction X, only one strip-shaped structure will be attached to the winding start end D1 of the electrode body 211.

[0153] In this embodiment, considering that the winding start end D1 is the structure on the electrode body 211 closest to the central hole H, the winding start end D1 is the structure on the electrode body 211 most prone to deformation and collapse towards the central hole H. Based on this, by setting the reinforcing coating 212 to be flush with the winding start end D1 of the electrode body 211, the support strength of the first electrode 21 at the winding start end D1 can be improved, further mitigating the problem of collapse at the central hole H.

[0154] In some embodiments, the yield strength of the reinforcing coating 212 is P1, where P1 satisfies 30 MPa ≤ P1 ≤ 400 MPa. Optionally, P1 can be one of 30 MPa, 50 MPa, 100 MPa, 200 MPa, and 400 MPa.

[0155] In this embodiment, by setting the yield strength P1 of the reinforcing coating 212 to not less than 30 MPa, the reinforcing coating 212 itself can have a certain strength, thereby reducing the risk of deformation and collapse in the area where the reinforcing coating 212 is located. At the same time, the yield strength P1 of the reinforcing coating 212 is set to not more than 400 MPa, so that the area where the reinforcing coating 212 is located can still curl to a certain extent, thereby meeting the winding requirements of the first electrode 21.

[0156] In some embodiments, the reinforcing coating 212 includes an insulating material.

[0157] In this embodiment, by providing the reinforcing coating 212 with insulating material, the reinforcing coating 212 can provide support strength while also serving as insulation, thereby reducing leakage problems caused by contact between the reinforcing coating 212 and components such as the outer casing 10, and improving the reliability of the battery cell.

[0158] In some embodiments, the reinforcing coating 212 includes at least one of hard carbon, graphite, soft carbon, silicon carbon, silicon oxide, conductive carbon, and conductive carbon nanotubes; and / or, the reinforcing coating 212 includes at least one of olefin-ester copolymers, such as ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, and ethylene-methacrylate copolymer.

[0159] Taking the first electrode 21 as the negative electrode as an example, hard carbon, graphite, soft carbon, silicon carbide, silicon oxide, conductive carbon, and conductive carbon nanotubes are all materials that can constitute the negative electrode. Based on this, by setting the reinforcing coating 212 to include at least one of hard carbon, graphite, soft carbon, silicon carbide, silicon oxide, conductive carbon, and conductive carbon nanotubes, the reinforcing coating 212 can have good adhesion and support strength, and is highly compatible with the preparation of the first electrode 21, requiring no additional equipment or processes, thus possessing strong practicality.

[0160] Alternatively, by providing the reinforcing coating 212 to include at least one of olefin-ester copolymers, such as ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, and ethylene-methacrylate copolymer, the reinforcing coating 212 can include a polymer, which can improve the supporting strength while reducing the impact on the overall weight of the first electrode 21, thus improving the energy density of the cylindrical battery cell 500.

[0161] In some embodiments, as shown in Figures 4 to 7, the size of the reinforcing coating 212 in the winding direction Z is L1, which satisfies: 1mm≤L1≤100mm; and / or, in the thickness direction Y of the electrode body 211, the size of the reinforcing coating 212 is L2, which satisfies: 4μm≤L2≤200μm.

[0162] In this embodiment, by setting the size L1 of the reinforcing coating 212 to be no less than 1 mm, the reinforcing coating 212 can have a certain coating area, allowing it to provide better support strength for the first electrode 21. Simultaneously, the size L1 of the reinforcing coating 212 is set to be no greater than 100 mm, thereby reducing the adverse effects of the reinforcing coating 212 on the energy density of the cylindrical battery cell 500 and increasing the capacity of the cylindrical battery cell 500. Optionally, L1 can be one of 1 mm, 5 mm, 10 mm, 50 mm, and 100 mm.

[0163] Furthermore, in some optional embodiments, L1 satisfies: 5mm≤L1≤70mm, and optionally, L1 is one of 5mm, 10mm, 30mm, 50mm and 70mm.

[0164] Similarly, by setting the size L2 of the reinforcing coating 212 to be no less than 4 μm, the reinforcing coating 212 can have a certain thickness, allowing it to provide better support strength for the first electrode 21. Simultaneously, the size L2 of the reinforcing coating 212 is set to be no greater than 200 μm to reduce the adverse effects of the reinforcing coating 212 on the energy density of the cylindrical battery cell 500 and to improve the capacity of the cylindrical battery cell 500. Optionally, L2 can be one of 4 μm, 50 μm, 100 μm, 150 μm, and 200 μm.

[0165] It should be noted that, in addition to adjusting and limiting the dimensions L1 and L2 of the reinforcing coating 212, the number of winding turns of the first electrode 21 can also be adjusted. Optionally, the number of winding turns of the first electrode 21 is W, where W satisfies: 1 ≤ W ≤ 10. For example, the number of winding turns W of the first electrode 21 is one of 1, 3, 5, 7, and 10. Limiting the number of winding turns W of the first electrode 21 can also reduce the risk of collapse at the central hole H and improve the reliability of the cylindrical battery cell 500. Further optionally, W satisfies: 2 ≤ W ≤ 7. For example, the number of winding turns W of the first electrode 21 is one of 2, 3, 5, 6, and 7.

[0166] In some embodiments, the density of the reinforcing coating 212 is R, where R satisfies: 0.65 g / cc ≤ R ≤ 3.7 g / cc. Optionally, R is one of 0.65 g / cc, 1.5 g / cc, 2.5 g / cc, 3 g / cc, and 3.7 g / cc.

[0167] Density often characterizes the compactness of a structure. In this embodiment, the density R of the reinforcing coating 212 is set to be no less than 0.65 g / cc, enabling the reinforcing coating 212 to possess a certain yield strength. This helps reduce the risk of deformation and collapse of the first electrode 21 at local locations, improving its reliability. Simultaneously, the density R of the reinforcing coating 212 is set to be no more than 3.7 g / cc, allowing the first electrode 21 to still have a certain degree of bending at the location where the reinforcing coating 212 is applied, thus meeting the winding requirements of the first electrode 21 and demonstrating strong practicality.

[0168] In some embodiments, the bonding strength of the reinforcing coating 212 is F, where F satisfies: 2 N / m ≤ F ≤ 100 N / m. Optionally, F is one of 2 N / m, 5 N / m, 20 N / m, 50 N / m, and 100 N / m.

[0169] The bonding strength and bonding effect are positively correlated; that is, the higher the bonding strength, the better the bonding effect of the reinforcing coating 212; the lower the bonding strength, the worse the bonding effect of the reinforcing coating 212. Based on this, this embodiment sets the bonding strength F of the reinforcing coating 212 to be no less than 2 N / m, ensuring a certain bonding effect between the reinforcing coating 212 and the electrode body 211. This reduces the risk of the reinforcing coating 212 detaching from the electrode body 211 under complex operating conditions, thereby further improving the reliability of the cylindrical battery cell 500. Simultaneously, by setting the bonding strength F to be no greater than 100 N / m, the adverse effects on the charging and discharging process of the cylindrical battery cell 500 caused by excessively strong bonding between the reinforcing coating 212 and the electrode body 211 are reduced.

[0170] In some embodiments, in the winding direction Z, the size ratio of the first region A1 to the second region A2 is A, where A satisfies: 0.5% ≤ A ≤ 10%.

[0171] In this embodiment, by setting A to not less than 0.5%, the electrode body 211 can receive the support and reinforcement effect of the reinforcing coating 212 within a certain area, thereby reducing the risk of deformation and collapse of the first electrode 21 towards the central hole H and improving the reliability of the cylindrical battery cell 500. Simultaneously, setting A to not more than 10% reduces the adverse effects of the reinforcing coating 212 on the energy density of the cylindrical battery cell 500, contributing to improved performance.

[0172] In some embodiments, referring to Figures 5, 10 and 11, the electrode body 211 further has a third region A3 located on the side of the second region A2 away from the first region A1 in the winding direction Z. The third region A3 extends from the winding end D2 of the electrode body 211 and is provided with a reinforcing coating 212.

[0173] The electrode body 211 has a first region A1, a second region A2, and a third region A3 arranged sequentially in the winding direction Z, with the first region A1 and the third region A3 located on opposite sides of the second region A2. The winding start end D1 is located within the first region A1, and the winding end D2 is located within the third region A3. Both the third region A3 and the first region A1 have a reinforcing coating 212, while the second region A2 does not have a reinforcing coating 212.

[0174] The first electrode 21 is typically formed on a larger electrode. During the formation of the electrode assembly 20, a portion of the structure in the larger electrode is bent and wound. Then, at the winding end D2, the larger electrode is cut to form the first electrode 21 within the electrode assembly 20. Based on this, this embodiment adds a reinforcing coating 212 in the third region A3. This reinforcing coating 212 separates the third region A3 from the second region A2. Furthermore, during the formation of the electrode assembly 20, the reinforcing coating 212 in the third region A3 can be used to position the winding end D2 of the electrode body 211, achieving fixed-length cutting during winding and improving the yield of the cylindrical battery cell 500.

[0175] In some embodiments, as shown in FIG5, the innermost winding of the first electrode 21 is located at the innermost winding of the second electrode 22.

[0176] The first electrode 21 can be wound multiple turns, wherein the innermost turn of the first electrode 21 is the part of the first electrode 21 that is closest to the central hole H. Similarly, the second electrode 22 can be wound multiple turns, wherein the innermost turn of the second electrode 22 is the part of the second electrode 22 that is closest to the central hole H.

[0177] In this embodiment, since the innermost winding of the first electrode 21 is located closer to the center hole H than the innermost winding of the second electrode 22, deformation and collapse of the first electrode 21 are more likely to adversely affect the center hole H. Therefore, by providing a reinforcing coating 212 in the first region A1 of the first electrode 21, the risk of deformation and collapse of the first electrode 21 towards the center hole H is reduced, thereby improving the reliability of the cylindrical battery cell 500.

[0178] It should be noted that the first region A1 and the innermost winding of the first electrode 21 can have various relative relationships. For example, the first region A1 may only include a portion of the structure of the innermost winding of the first electrode 21, meaning that the reinforcing coating 212 may only be provided in a portion of the innermost winding of the first electrode 21. Alternatively, the first region A1 may completely include the innermost winding of the first electrode 21, meaning that the reinforcing coating 212 may completely cover the innermost winding of the first electrode 21.

[0179] In some embodiments, the first electrode 21 is a negative electrode and the second electrode 22 is a positive electrode.

[0180] In related technologies, in some types of cylindrical battery cells 500, such as metal battery cells, the yield strength of the negative electrode may be lower than that of the positive electrode. This makes the negative electrode more prone to deformation and collapse towards the central hole H compared to the positive electrode. Therefore, this embodiment of the application adjusts the negative electrode, i.e., the first electrode 21, by adding a reinforcing coating 212. The reinforcing coating 212 reduces the risk of deformation and collapse of the first electrode 21 near the central hole H, thereby improving the reliability of the cylindrical battery cell 500.

[0181] In some embodiments, referring to Figures 7 and 12, the electrode body 211 includes a first current collector 2111 and a base coating 2112 located on at least one side of the first current collector 2111, with a reinforcing coating 212 located on the side of the base coating 2112 opposite to the first current collector 2111. The second electrode 22 includes a second current collector 221 and an active material layer 222 located on at least one side of the second current collector 221, the thickness of the active material layer 222 being greater than the thickness of the base coating 2112.

[0182] The first current collector 2111 can be a negative electrode current collector. Optionally, the first current collector 2111 can include a metal foil, which can be made of pure metal, alloy, or surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The base coating 2112 is a film structure disposed on the first current collector 2111 to enhance the adhesion between the first current collector 2111 and the electrolyte and improve the electrochemical performance. Optionally, the base coating 2112 is a mixture film composed of polymer materials, conductive agents, and additives.

[0183] The second current collector 221 can be a positive current collector. Optionally, the second current collector 221 can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. The active material layer 222 is a film layer disposed on the second current collector 221 and including a positive active material. Optionally, the positive active material can include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds.

[0184] For some types of cylindrical battery cells 500, such as metal battery cells, a negative electrode active material layer 222 may not be provided, only a first current collector 2111 and a base coating layer 2112 are provided. Furthermore, the thickness of the active material layer 222 is often greater than the thickness of the base coating layer 2112, which may result in the yield strength of the first electrode 21 being less than that of the second electrode 22. Therefore, this embodiment of the application adjusts the first electrode 21 by adding a reinforcing coating 212. The reinforcing coating 212 reduces the risk of deformation and collapse of the first electrode 21 near the central hole H, thereby improving the reliability of the cylindrical battery cell 500.

[0185] In some embodiments, the cylindrical battery cell 500 is a metal battery cell.

[0186] In this embodiment, since the cylindrical battery cell 500 is a metal battery cell, the first electrode 21 and the second electrode 22 within the electrode assembly 20 may have a difference in yield strength, which could cause the first electrode 21 to deform and collapse more easily towards the central hole H. Therefore, this embodiment adjusts the first electrode 21 by adding a reinforcing coating 212. The reinforcing coating 212 reduces the risk of deformation and collapse of the first electrode 21 near the central hole H, thereby improving the reliability of the cylindrical battery cell 500.

[0187] Secondly, embodiments of this application provide a battery device, which includes the cylindrical battery cell 500 in any of the foregoing embodiments.

[0188] It should be noted that the battery device provided in this application embodiment has the beneficial effects of the cylindrical battery cell 500 in any of the foregoing embodiments. For details, please refer to the foregoing description of the beneficial effects of the cylindrical battery cell 500. This application embodiment will not repeat the description.

[0189] Thirdly, the embodiments of this application provide an electrical device, which includes a cylindrical battery cell 500 in any of the foregoing embodiments and a battery device in any of the foregoing embodiments. The cylindrical battery cell 500 or the battery device is used to provide electrical energy.

[0190] It should be noted that the power device provided in this application embodiment has the beneficial effects of the cylindrical battery cell 500 in any of the foregoing embodiments. For details, please refer to the foregoing description of the beneficial effects of the cylindrical battery cell 500. This application embodiment will not repeat the description.

[0191] According to some embodiments of this application, please refer to Figures 4, 5, 10, 11, and 12. The cylindrical battery cell 500 is a metal battery cell and includes a housing 10 and an electrode assembly 20. The electrode assembly 20 is housed within the housing 10 and includes a first electrode 21 and a second electrode 22 with opposite polarities. The first electrode 21 is the negative electrode, and the second electrode 22 is the positive electrode. The first electrode 21 and the second electrode 22 are wound along the winding direction Z.

[0192] The first electrode 21 includes an electrode body 211 and a reinforcing coating 212. The electrode body 211 has a first region A1, a second region A2 and a third region A3 arranged sequentially adjacent to each other along the winding direction Z. The first region A1 extends from the winding start end D1 of the electrode body 211, and the third region A3 extends from the winding end end D2 of the electrode body 211. Both the first region A1 and the third region A3 are provided with the reinforcing coating 212, while the second region A2 is not provided with the reinforcing coating 212. The innermost winding of the first electrode 21 is located inside the innermost winding of the second electrode 22.

[0193] Along the axial direction X of the cylindrical battery cell 500, the electrode body 211 includes a main body B1 and a tab B2. The main body B1 has a reinforcing coating 212 in a first region A1, while the tab B2 does not have a reinforcing coating 212 in the first region A1. The reinforcing coating 212 covers the structure of the main body B1 in the first region A1; alternatively, the reinforcing coating 212 includes a plurality of spaced reinforcing strips 2121. The reinforcing coating 212 is disposed on both sides of the electrode body 211 in its thickness direction Y, and is flush with the winding start end D1 of the electrode body 211. The yield strength of the reinforcing coating 212 is P1, which satisfies 30 MPa ≤ P1 ≤ 400 MPa. The reinforcing coating 212 includes an insulating material.

[0194] The reinforcing coating 212 includes at least one of hard carbon, graphite, soft carbon, silicon carbon, silicon oxide, conductive carbon, and conductive carbon nanotubes; and / or, the reinforcing coating 212 includes at least one of olefin-ester copolymers, such as ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, and ethylene-methacrylate copolymer.

[0195] In the winding direction Z, the size of the reinforcing coating 212 is L1, and L1 satisfies: 1mm≤L1≤100mm; and / or, in the thickness direction Y of the electrode body 211, the size of the reinforcing coating 212 is L2, and L2 satisfies: 4μm≤L2≤200μm.

[0196] The density of the reinforcing coating 212 is R, which satisfies: 0.65g / cc≤R≤3.7g / cc. The bonding strength of the reinforcing coating 212 is F, which satisfies: 2N / m≤F≤100N / m. In the winding direction Z, the size ratio of the first region A1 to the second region A2 is A, which satisfies: 0.5%≤A≤10%.

[0197] The electrode body 211 includes a first current collector 2111 and a base coating 2112 located on one side of the first current collector 2111, and a reinforcing coating 212 located on the side of the base coating 2112 away from the first current collector 2111; the second electrode 22 includes a second current collector 221 and an active material layer 222 located on one side of the second current collector 221, and the thickness of the active material layer 222 is greater than the thickness of the base coating 2112.

[0198] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. 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 cylindrical battery cell, comprising: shell; An electrode assembly is housed within the housing, the electrode assembly comprising a first electrode and a second electrode with opposite polarities, the first electrode and the second electrode being wound along a winding direction; The first electrode includes an electrode body and a reinforcing coating. The electrode body has a first region and a second region arranged adjacent to each other along the winding direction. The first region extends from the winding start end of the electrode body and is provided with the reinforcing coating, while the second region is not provided with the reinforcing coating.

2. The cylindrical battery cell according to claim 1, wherein, Along the axial direction of the cylindrical battery cell, the electrode body includes a main body and a tab. The main body has the reinforcing coating in the first region, while the tab does not have the reinforcing coating in the first region.

3. The cylindrical battery cell according to claim 2, wherein, The reinforcing coating covers the structure of the main body within the first region; or... The reinforcing coating includes multiple reinforcing strips spaced apart.

4. The cylindrical battery cell according to claim 1, wherein, The reinforcing coating is applied to both sides of the electrode body in the direction of its thickness.

5. The cylindrical battery cell according to claim 1, wherein, The reinforcing coating is flush with the starting end of the winding of the electrode body.

6. The cylindrical battery cell according to claim 1, wherein, The yield strength of the reinforcing coating is P1, which satisfies 30 MPa ≤ P1 ≤ 400 MPa.

7. The cylindrical battery cell according to claim 1, wherein, The reinforcing coating includes an insulating material.

8. The cylindrical battery cell according to claim 1, wherein, The reinforcing coating comprises at least one of hard carbon, graphite, soft carbon, silicon-carbon, silicon-oxygen, conductive carbon, and conductive carbon nanotubes; and / or, The reinforcing coating includes at least one of olefin-ester copolymers, such as ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, and ethylene-methacrylate copolymer.

9. The cylindrical battery cell according to claim 1, wherein, In the winding direction, the size of the reinforcing coating is L1, where L1 satisfies: 1mm ≤ L1 ≤ 100mm; and / or, In the thickness direction of the electrode body, the size of the reinforcing coating is L2, and L2 satisfies: 4μm≤L2≤200μm.

10. The cylindrical battery cell according to claim 1, wherein, The density of the reinforcing coating is R, and R satisfies: 0.65g / cc≤R≤3.7g / cc.

11. The cylindrical battery cell according to claim 1, wherein, The bonding strength of the reinforcing coating is F, which satisfies: 2N / m≤F≤100N / m.

12. The cylindrical battery cell according to claim 1, wherein, In the winding direction, the size ratio of the first region to the second region is A, where A satisfies: 0.5% ≤ A ≤ 10%.

13. The cylindrical battery cell according to claim 1, wherein, In the winding direction, the electrode body also has a third region located on the side of the second region opposite to the first region, the third region extending from the winding end of the electrode body and having the reinforcing coating.

14. The cylindrical battery cell according to claim 1, wherein, The innermost winding of the first electrode is located inside the innermost winding of the second electrode.

15. The cylindrical battery cell according to claim 1, characterized in that, The first electrode is the negative electrode, and the second electrode is the positive electrode.

16. The cylindrical battery cell according to claim 1, wherein, The electrode body includes a first current collector and a base coating located on one side of the first current collector, and the reinforcing coating is located on the side of the base coating opposite to the first current collector; The second electrode includes a second current collector and an active material layer located on one side of the second current collector, wherein the thickness of the active material layer is greater than the thickness of the base coating.

17. The cylindrical battery cell according to claim 1, wherein the cylindrical battery cell is a metal battery cell.

18. A battery device comprising a plurality of cylindrical battery cells according to any one of claims 1 to 17.

19. An electrical device comprising a cylindrical battery cell according to any one of claims 1 to 17, or a battery device according to claim 18, wherein the cylindrical battery cell or the battery device is used to store or provide electrical energy.

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