Cylindrical battery cell, battery device, and electric device

Abstract

The application discloses a cylindrical battery monomer, a battery device and a power utilization device. The cylindrical battery monomer comprises a shell, an electrode assembly and a first electrode lead-out piece. The electrode assembly is arranged in the shell, the electrode assembly is in a winding structure, the electrode assembly comprises a first pole piece, a separator and a second pole piece, the separator is arranged between the first pole piece and the second pole piece, the first pole piece and the second pole piece are opposite in polarity, the first pole piece comprises a plurality of first sub-pole pieces arranged intermittently along a winding direction, and each first sub-pole piece is provided with a first pole lug on one side along a winding axis direction. The first electrode lead-out piece is located on one side of the electrode assembly along the winding axis direction, and the first pole lug of each first sub-pole piece is electrically connected with the first electrode lead-out piece. The technical scheme provided by the application can improve the charge-discharge performance and reliability of the battery device.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a cylindrical battery cell, a battery device, and an electrical device. Background Technology

[0002] Battery devices 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.

[0003] In the development of battery technology, how to improve the charging and discharging performance and reliability of battery devices is a technical problem that urgently needs to be solved. Utility Model Content

[0004] This application provides a cylindrical battery cell, a battery device, and an electrical device. The technical solution provided by this application can improve the charging and discharging performance and reliability of the battery device.

[0005] This application is achieved through the following technical solution:

[0006] In a first aspect, some embodiments of this application provide a cylindrical battery cell, which includes a casing, an electrode assembly, and a first electrode lead. The electrode assembly is disposed within the casing and has a wound structure. The electrode assembly includes a first electrode, a separator, and a second electrode, with the separator disposed between the first and second electrodes. The first and second electrodes have opposite polarities. The first electrode includes multiple segments of first sub-electrodes arranged discontinuously along the winding direction, and each segment of the first sub-electrode has a first tab on one side along the winding axis. The first electrode lead is located on one side of the electrode assembly along the winding axis, and the first tab of each segment of the first sub-electrode is electrically connected to the first electrode lead.

[0007] In the above scheme, the first electrode has a multi-segment structure, with multiple segments of the first sub-electrode arranged intermittently along the winding direction. Each segment of the first sub-electrode is connected to the first electrode lead through a corresponding first tab. On the one hand, the gap between two adjacent segments of the first sub-electrode provides space for the expansion of the electrode assembly, thereby releasing the internal stress of the electrode assembly and reducing the risk of the electrode breaking due to stress concentration, thus enabling the cylindrical battery cell to have high reliability. On the other hand, the multiple segments of the first sub-electrode are connected in parallel, shortening the current path between the electrode assembly and the first electrode lead, effectively reducing the internal resistance of the electrode assembly, thus enabling the cylindrical battery cell to have high charge and discharge performance, and consequently enabling the battery device to have high reliability and charge and discharge performance.

[0008] According to some embodiments of this application, along the winding direction, the sum of the lengths of all the first sub-electrodes is H1, and the sum of the dimensions of the gaps between all the first sub-electrodes is H2, satisfying that 0.001≤H2 / (H1+H2)≤0.05; optionally, 0.008≤H2 / (H1+H2)≤0.01.

[0009] In the above scheme, by limiting the relationship between the size of the gap between the first sub-electrodes and the size of the first sub-electrodes, it is possible to take into account that the first sub-electrodes of the multi-segment structure provide a certain reserved space for the expansion of the electrode assembly, reduce the risk of stress concentration inside the wound electrode assembly causing electrode breakage, and reduce the risk of the volumetric energy density being affected by the reduction of active material inside the cylindrical battery cell due to excessive gap size. In this way, the battery device has high reliability and volumetric energy density.

[0010] According to some embodiments of this application, the first electrode includes an inner ring first sub-electrode and an outer ring first sub-electrode, wherein the terminal end of the inner ring first sub-electrode is closer to the winding axis of the electrode assembly than the terminal end of the outer ring first sub-electrode. On the same projection plane perpendicular to the winding axis, the line connecting the orthographic projection of the terminal end of the inner ring first sub-electrode and the orthographic projection of the winding axis is a first line, and the line connecting the orthographic projection of the terminal end of the outer ring first sub-electrode and the orthographic projection of the winding axis is a second line. The angle between the first line and the second line is greater than or equal to 0° and less than or equal to 20°.

[0011] In the above scheme, by setting the deviation angle of the end of the two adjacent first sub-electrodes about the winding axis to less than 20°, the electrode assembly can have a high roundness, which is conducive to improving the efficiency of electrode assembly insertion into the casing and enabling the cylindrical battery cell to have a high manufacturing efficiency.

[0012] According to some embodiments of this application, the first electrode lead-out includes a first current collector, which is located inside the housing, and the first electrode tab is connected to the first current collector via a solder joint.

[0013] In the above scheme, each first electrode tab is connected to the first current collector through a soldering part, so that each first sub-electrode and the first current collector have a stable physical connection and electrical connection, reducing the risk of breakage between the first sub-electrode and the first current collector, and improving the charging and discharging performance of the cylindrical battery cell.

[0014] According to some embodiments of this application, on the same projection plane perpendicular to the winding axis, there is an overlapping area between the orthographic projection of each segment of the first electrode tab and the orthographic projection of the first current collector.

[0015] In the above scheme, each segment of the first electrode tab overlaps with the first current collector, which can reduce the risk of no direct overcurrent between the innermost or outermost first electrode tab and the first current collector. This results in a shorter current path between each segment of the first sub-electrode and the first current collector in the electrode assembly, effectively reducing the internal resistance of the electrode assembly. This allows the cylindrical battery cell to have higher charge and discharge performance, thereby enabling the battery device to have higher reliability and charge and discharge performance.

[0016] According to some embodiments of this application, on the same projection plane perpendicular to the winding axis, there is an overlapping area between the orthographic projection of each segment of the first sub-electrode and the orthographic projection of the first current collector.

[0017] In the above scheme, each segment of the first sub-electrode overlaps with the first current collector, which can reduce the risk of no direct overcurrent between the first sub-electrode and the first current collector due to the discontinuous arrangement between the first sub-electrodes. This results in a shorter current path between each segment of the first sub-electrode and the first current collector in the electrode assembly, effectively reducing the internal resistance of the electrode assembly. This allows the cylindrical battery cell to have higher charge and discharge performance, thereby enabling the battery device to have higher reliability and charge and discharge performance.

[0018] According to some embodiments of this application, the cylindrical battery cell further includes an electrolyte and a first connector, with the electrolyte disposed within the casing. Adjacent first sub-electrode segments are connected by the first connector, which is soluble in the electrolyte.

[0019] In the above scheme, the first sub-electrode segments of adjacent sections are connected by the first connector, which can reduce the winding difficulty of the first sub-electrode and improve the manufacturing efficiency of the electrode assembly. When the electrode assembly is inserted into the shell and the electrolyte is injected into the shell, the first connector is dissolved after being soaked in the electrolyte, which can release the reserved space for the expansion of the electrode assembly, reduce the risk of electrode breakage caused by stress concentration inside the electrode assembly, and make the cylindrical battery cell have high reliability and manufacturing efficiency, thereby making the battery device have high reliability and manufacturing efficiency.

[0020] According to some embodiments of this application, the first connector between two adjacent first sub-electrode segments is wound at least once.

[0021] In the above scheme, by winding the first connector between the two first sub-electrodes at least one turn, a reserved space is provided for the electrode assembly after the first connector is dissolved, absorbing the expansion force in any direction in the circumference of the electrode assembly, effectively reducing the risk of electrode breakage caused by stress concentration inside the electrode assembly, making the cylindrical battery cell highly reliable, and thus making the battery device highly reliable.

[0022] According to some embodiments of this application, the first connector is bonded to the first sub-electrode.

[0023] In the above scheme, the first connector is bonded to the first sub-electrode, which can reduce the connection difficulty between the first connector and the first sub-electrode, which is conducive to improving the manufacturing efficiency of the electrode assembly, and thus to improving the manufacturing efficiency of the cylindrical battery cell and battery device.

[0024] According to some embodiments of this application, the first connector includes a base layer and an adhesive layer, the adhesive layer being disposed on the base layer. The base layer material includes polycaprolactone, polycarbonate, polycarbonate-type polyurethane, or polyethylene oxide. The adhesive layer material includes polycarbonate-type polyurethane, biodegradable segmental acrylate copolymer, polycaprolactone, polyether-polyurethane block copolymer, polyethylene oxide, or polyether-acrylate block copolymer.

[0025] In the above scheme, the first connector includes a base layer and an adhesive layer. The base layer is bonded to the first sub-electrode through the adhesive layer. By setting the materials of the base layer and the adhesive layer to be materials that can be dissolved by the electrolyte, the first connector can be dissolved after the electrode assembly is installed in the shell and wetted by the electrolyte. This releases the space reserved for expansion between the two sections of the first sub-electrode, reducing the risk of electrode breakage caused by stress concentration inside the electrode assembly, and making the cylindrical battery cell and battery device have high reliability.

[0026] According to some embodiments of this application, the battery cell further includes a first protective member, which is connected to at least one side of the first sub-electrode along its thickness direction. A first connector is connected to the side of the first protective member opposite to the first sub-electrode.

[0027] Compared to the scheme where the first connector is directly connected to the first sub-electrode, in the above scheme, after the first connector is dissolved, the first protective component can protect the end of the first sub-electrode, reducing the risk of positive and negative electrodes colliding due to burrs generated during processing piercing the separator at the connection between the first sub-electrode and the first connector. This results in higher reliability for the cylindrical battery cell and battery device.

[0028] According to some embodiments of this application, the first protective element includes a first protective film and a second protective film. One end of the first protective film and one end of the second protective film are respectively connected to both sides of the first sub-electrode along the thickness direction, and the other end of the first protective film and the other end of the second protective film are connected.

[0029] In the above scheme, the first protective film and the second protective film are respectively connected to both sides of the first sub-electrode along its thickness direction. On the one hand, this enables a stable connection between the first sub-electrode, the first protective component, and the first connecting component, which is beneficial for the winding and forming of the electrode assembly and reduces the risk of the first sub-electrode separating during the winding process, affecting the yield of the electrode assembly. This results in higher manufacturing efficiency for the cylindrical battery cell and the power device. On the other hand, it effectively shields the burrs generated at the ends of the first sub-electrode due to cutting, reducing the risk of burrs piercing the separator and resulting in higher reliability for the cylindrical battery cell and the battery device.

[0030] According to some embodiments of this application, the first connector is connected to at least one of the first protective film and the second protective film.

[0031] In the above scheme, the first connector is connected to at least one of the first protective film and the second protective film, so that the first connector is stably connected to the first sub-electrode through the first protective film, which is beneficial to the efficiency of the electrode assembly winding and forming, facilitates the insertion of the electrode assembly into the shell, and enables the cylindrical battery cell to have high manufacturing efficiency.

[0032] According to some embodiments of this application, on the same projection plane perpendicular to the thickness direction, the orthographic projection of the first connector, the orthographic projection of the first protective member, and the orthographic projection of the first sub-electrode have an overlapping area. Along the winding direction, the width of the overlapping area is greater than 1 mm and less than or equal to the width of the first protective member.

[0033] In the above scheme, the overlap width of the first connector, the first protective member, and the first sub-electrode is limited to greater than or equal to 1 mm, so that there is a reliable connection between the first connector and the first protective member, which is beneficial to the efficiency of the electrode assembly winding and forming, and facilitates the insertion of the electrode assembly into the casing, thus enabling the cylindrical battery cell to have high manufacturing efficiency. The overlap width of the first connector and the first protective member is limited to less than or equal to the width of the first protective member, which can reduce the risk that the thickness difference between two adjacent first sub-electrode sheets will be too large due to the excessive connection size of the first connector and the first protective member, thus affecting the roundness of the electrode assembly, so that the electrode assembly has a high roundness, which facilitates the insertion of the electrode assembly into the casing, and enables the cylindrical battery cell to have high manufacturing efficiency.

[0034] According to some embodiments of this application, the second electrode includes multiple segments of second sub-electrodes arranged discontinuously along the winding direction, and each segment of the second sub-electrode has a second tab on one side along the winding axis. The cylindrical battery cell also includes a second electrode lead, which is located on the side of the electrode assembly opposite to the first electrode lead along the winding axis, and the second tab of each segment of the second sub-electrode is electrically connected to the second electrode lead.

[0035] In the above scheme, the second electrode has a multi-segment structure, with multiple segments of the second sub-electrode arranged intermittently along the winding direction. Each segment of the second sub-electrode is connected to the second electrode lead through a corresponding second tab. On the one hand, the gap between two adjacent segments of the second sub-electrode provides space for the expansion of the electrode assembly, thereby releasing the internal stress of the electrode assembly and reducing the risk of electrode breakage due to stress concentration, thus enabling the cylindrical battery cell to have high reliability. On the other hand, the multiple segments of the second sub-electrode are connected in parallel, shortening the current path between the electrode assembly and the second electrode lead, effectively reducing the internal resistance of the electrode assembly, enabling the cylindrical battery cell to have high charge and discharge performance, and thus enabling the battery device to have high reliability and charge and discharge performance.

[0036] Secondly, some embodiments of this application provide a battery device, which includes the cylindrical battery cell provided in the first aspect.

[0037] Thirdly, some embodiments of this application provide an electrical device, which includes a cylindrical battery cell provided in the first aspect, or a battery device provided in the second aspect.

[0038] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of a vehicle in some embodiments of this application;

[0041] Figure 2 This is an exploded perspective view of the battery device in some embodiments of this application;

[0042] Figure 3 A perspective view of a cylindrical battery cell provided in some embodiments of this application;

[0043] Figure 4 An exploded perspective view of a cylindrical battery cell provided in some embodiments of this application;

[0044] Figure 5 This is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application;

[0045] Figure 6A schematic diagram of the structure of an electrode assembly with a hidden separator and a second electrode sheet provided for some embodiments of this application;

[0046] Figure 7 A schematic diagram of an electrode assembly and a first current collector provided in some embodiments of this application;

[0047] Figure 8 This is a schematic diagram of the electrode assembly structure in some embodiments of this application;

[0048] Figure 9 for Figure 8 Enlarged view of point A in the middle;

[0049] Figure 10 This is a schematic diagram of the structure of the first connector provided in some embodiments of this application;

[0050] Figure 11 Schematic diagrams of the structure of the first sub-electrode, the first protective member, and the first connector provided in some embodiments of this application;

[0051] Figure 12 for Figure 11 Enlarged view of point B in the middle.

[0052] Icons: 1000 - Vehicle; 100 - Battery Unit; 200 - Controller; 300 - Motor; 20 - Housing; 21 - First Housing Body; 22 - Second Housing Body; 10 - Cylindrical Battery Cell; 11 - Casing; 110 - Shell; 111 - Cover; 12 - Electrode Assembly; 30 - First Electrode; 31 - First Sub-Electrode; 31a - Inner Ring First Sub-Electrode; 31b - Outer Ring First Sub-Electrode; 310 - Current Collector; 311 - Active Material Layer; 3 2-First electrode tab; 40-Second electrode plate; 41-Second sub-electrode plate; 42-Second electrode tab; 50-Separating membrane; 60-First electrode lead-out component; 61-First current collector component; 610-Soldering part; 62-First electrode terminal; 70-First connector; 71-Base layer; 72-Adhesive layer; 80-First protective component; 81-First protective film; 82-Second protective film; 90-Second electrode lead-out component; y-Wounding direction; z-Wounding axis direction. Detailed Implementation

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] In this application, "multiple paragraphs" refers to two or more paragraphs (including two paragraphs).

[0060] In this application, "multiple" refers to two or more (including two paragraphs).

[0061] 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.

[0062] 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.

[0063] 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, serves to prevent short circuits to some extent while allowing active ions to pass through.

[0064] 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.

[0065] 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.

[0066] 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 with a silver-plated surface, stainless steel with a silver-plated surface, 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.).

[0067] 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 Co1 / 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 NCM1), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM6), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0068] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, 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 can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

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

[0070] As an example, the negative electrode current collector 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 electrode, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, 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.).

[0071] 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.

[0072] 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.

[0073] 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.

[0074] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0075] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0076] In some embodiments, the separator is a separator membrane. The separator membrane can be of various types, and any known porous separator membrane with good chemical and mechanical stability can be selected.

[0077] As an example, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0078] 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.

[0079] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0080] In some embodiments, the electrolyte salt may include 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.

[0081] In some embodiments, the solvent may include at least one selected from 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 selected from 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.

[0082] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0083] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0084] As an example, polymer solid electrolytes can be polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0085] As an example, inorganic solid electrolytes may include 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 phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0086] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0087] In some implementations, the electrode assembly has a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0088] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0089] In some embodiments, the electrode assembly has tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0090] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0091] As an example, a 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, but are not limited to, square battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0092] 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.

[0093] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; 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 a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0094] 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.

[0095] 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.

[0096] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0097] As an example, the enclosure may include a first enclosure body and a second enclosure body. The first enclosure body and the second enclosure body are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, which can be either sealed or unsealed. The first enclosure body may be a top cover or a bottom plate.

[0098] 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.

[0099] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0100] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. The energy storage device includes energy storage containers, energy storage cabinets, etc. In some embodiments, one or more energy storage devices may constitute at least part of an energy storage system.

[0101] Battery devices possess outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide applicability, and low self-discharge coefficient, making them an important component of today's new energy development. The development of battery technology must simultaneously consider multiple design factors, such as performance parameters like energy density, cycle life, and discharge capacity. Furthermore, the charge and discharge performance of the battery device must also be taken into account.

[0102] In related technologies, a cylindrical battery cell includes a casing and an electrode assembly. The electrode assembly has a wound structure and includes a positive electrode, a separator, and a negative electrode, with the separator positioned between the positive and negative electrodes. The positive electrode, separator, and negative electrode are wound together about a winding axis. As the number of winding turns increases, the winding force of the electrode layers closer to the winding axis increases, and the gap between the electrode layers decreases. With the increase in the number of charge-discharge cycles of the cylindrical battery cell, the internal expansion force of the electrode assembly gradually increases, and the risk of stress concentration between the electrode layers near the winding axis increases. Stress concentration can lead to electrode breakage, affecting the charge-discharge performance and reliability of the cylindrical battery cell. In particular, with the increasing demand for high capacity, the number of electrode winding layers also increases. In high-capacity battery cells, the risk of stress concentration leading to electrode breakage is even greater, and the impact on the charge-discharge performance and reliability of the cylindrical battery cell is even more severe.

[0103] In view of this, to improve the problem of electrode breakage caused by internal stress concentration in cylindrical battery cells, which affects the reliability and charge / discharge performance of cylindrical battery cells, some embodiments of this application provide a cylindrical battery cell, which includes a casing, an electrode assembly, and a first electrode lead-out member. The electrode assembly is disposed inside the casing and has a wound structure. The electrode assembly includes a first electrode, a separator, and a second electrode. The separator is disposed between the first and second electrode. The first and second electrode have opposite polarities. The first electrode includes multiple segments of first sub-electrode arranged discontinuously along the winding direction. Each segment of the first sub-electrode has a first tab on one side along the winding axis. The first electrode lead-out member is located on one side of the electrode assembly along the winding axis, and the first tab of each segment of the first sub-electrode is electrically connected to the first electrode lead-out member.

[0104] In the above scheme, the first electrode has a multi-segment structure, with multiple segments of the first sub-electrode arranged intermittently along the winding direction. Each segment of the first sub-electrode is connected to the first electrode lead through a corresponding first tab. On the one hand, the gap between two adjacent segments of the first sub-electrode provides space for the expansion of the electrode assembly, thereby releasing the internal stress of the electrode assembly and reducing the risk of the electrode breaking due to stress concentration, thus enabling the cylindrical battery cell to have high reliability. On the other hand, the multiple segments of the first sub-electrode are connected in parallel, shortening the current path between the electrode assembly and the first electrode lead, effectively reducing the internal resistance of the electrode assembly, thus enabling the cylindrical battery cell to have high charge and discharge performance, and consequently enabling the battery device to have high reliability and charge and discharge performance.

[0105] The cylindrical battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft.

[0106] The technical solutions described in the embodiments of this application are applicable to battery devices, energy storage devices using battery devices, and electrical devices using battery devices.

[0107] Energy storage devices may include energy storage containers, energy storage cabinets, etc. For example, an energy storage cabinet may include a cabinet and one or more battery cells and / or battery devices mounted on the cabinet.

[0108] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be new energy vehicles, including pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles; 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. The electrical devices in the embodiments of this application include, but are not limited to, those mentioned above.

[0109] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0110] Figure 1 This is a schematic diagram of vehicle 1000 in some embodiments of this application.

[0111] The electrical device is a vehicle 1000. Inside the vehicle 1000, a controller 200, a motor 300, and a battery device 100 can be installed. The controller 200 controls the battery device 100 to supply power to the motor 300. 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, it can serve as the operating power source for the vehicle 1000's electrical system, such as meeting the power requirements for starting, navigation, and operation. In another embodiment of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000 but also as the driving power source, replacing or partially replacing fuel or natural gas to provide driving power to the vehicle 1000.

[0112] Please refer to Figure 2 , Figure 2 This is an exploded perspective view of the battery device 100 in some embodiments of this application. The battery device 100 includes a housing 20 and cylindrical battery cells 10, which are housed within the housing 20.

[0113] The housing 20 provides an assembly space for the cylindrical battery cell 10, and the housing 20 can adopt various structures. In some embodiments, the housing 20 may include a first housing body 21 and a second housing body 22, which overlap each other, and together define an assembly space for accommodating the battery cell. The second housing body 22 may be a hollow structure open at one end, and the first housing body 21 may be a plate-like structure, with the first housing body 21 covering the open side of the second housing body 22 so that the first housing body 21 and the second housing body 22 together define the assembly space; alternatively, the first housing body 21 and the second housing body 22 may both be hollow structures open on one side, with the open side of the first housing body 21 covering the open side of the second housing body 22.

[0114] Of course, the box 20 formed by the first box body 21 and the second box body 22 can be of various shapes, such as cylinder, cuboid or cube.

[0115] In the battery device 100, there can be one or more cylindrical battery cells 10 disposed within the housing 20. When there are multiple cylindrical battery cells 10 disposed within the housing 20, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that the multiple cylindrical battery cells 10 are connected in both series and parallel configurations. The multiple cylindrical battery cells 10 can be directly connected in series, in parallel, or in a mixed configuration together, and then the entire assembly of the multiple cylindrical battery cells 10 is housed within the housing 20. Alternatively, the battery device 100 can also be composed of multiple cylindrical battery cells 10 first connected in series, in parallel, or in a mixed configuration to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 20.

[0116] In some embodiments, the battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar for connecting multiple cylindrical battery cells 10 to achieve electrical connection between the multiple cylindrical battery cells 10.

[0117] For example, the housing 20 is provided with multiple battery cell assemblies, each battery cell assembly including multiple cylindrical battery cells 10, which are connected in series with each other via a busbar. In some embodiments, the multiple battery cell assemblies can be connected in series with each other via a busbar.

[0118] Each cylindrical battery cell 10 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited to these.

[0119] Some embodiments of this application provide a cylindrical battery cell 10; please refer to [link to relevant documentation]. Figures 3-6 , Figure 3 This is a perspective view of a cylindrical battery cell 10 provided in some embodiments of this application. Figure 4 This is an exploded perspective view of a cylindrical battery cell 10 provided in some embodiments of this application. Figure 5 This is a schematic diagram of the structure of the electrode assembly 12 provided in some embodiments of this application. Figure 6 This is a schematic diagram of the structure of an electrode assembly 12 that conceals the separator 50 and the second electrode 40, provided for some embodiments of this application.

[0120] The cylindrical battery cell 10 includes a housing 11, an electrode assembly 12, and a first electrode lead-out member 60. The electrode assembly 12 is disposed within the housing 11 and has a wound structure. The electrode assembly 12 includes a first electrode 30, a separator 50, and a second electrode 40. The separator 50 is disposed between the first electrode 30 and the second electrode 40. The first electrode 30 and the second electrode 40 have opposite polarities. The first electrode 30 includes multiple segments of first sub-electrodes 31 arranged discontinuously along the winding direction y. Each segment of the first sub-electrode 31 has a first tab 32 on one side along the winding axis direction z. The first electrode lead-out member 60 is located on one side of the electrode assembly 12 along the winding axis direction z, and the first tab 32 of each first sub-electrode 31 is electrically connected to the first electrode lead-out member 60.

[0121] The housing 11 is a component for housing the electrode assembly 12, and the housing 11 can also be used to house an electrolyte, such as an electrolyte solution. In some embodiments, the housing 11 is cylindrical in shape.

[0122] Please see Figure 3 and Figure 4 In some embodiments, the housing 11 includes a housing 110 and a cover 111. The housing 110 has an internal cavity for accommodating the electrode assembly 12, and the housing 110 has an opening communicating with the cavity. The cover 111 closes to the opening of the housing 110 to form a closed space for accommodating the electrode assembly 12 and the electrolyte (e.g., electrolyte solution).

[0123] The housing 110 is cylindrical in shape. In some embodiments, the housing 110 may be made of metal or a combination of metal and non-metal. For example, the housing 110 may be made of metal, such as copper, iron, aluminum, steel, stainless steel or aluminum alloy.

[0124] In some embodiments, the cover 111 may be made of metal or a combination of metal and non-metal. For example, the cover 111 may be made of metal, such as copper, iron, aluminum, steel, or aluminum alloy. In other embodiments, the cover 111 may be made of non-metallic materials, such as plastic or ceramic.

[0125] In some embodiments, the material of the cover 111 and the material of the housing 110 may be the same, and the two are connected to each other. Optionally, the connection relationship between the cover 111 and the housing 110 is diverse, including but not limited to welding, bonding, riveting, and other connection methods.

[0126] The electrode assembly 12 includes a first electrode 30, a second electrode 40, and a separator 50. The separator 50 is disposed between the first electrode 30 and the second electrode 40. The electrode assembly 12 has a wound structure, with the first electrode 30, the second electrode 40, and the separator 50 wound together around the axis of the electrode assembly 12. The first electrode 30 and the second electrode 40 have opposite polarities, that is, one of the first electrode 30 and the second electrode 40 is a positive electrode, and the other is a negative electrode.

[0127] Please see Figure 6 The first electrode 30 has a multi-segment structure, comprising multiple first sub-electrodes 31. The number of first sub-electrodes 31 can be two, three, or more. Along the winding direction y, the multiple first sub-electrodes 31 are arranged at intervals, with adjacent segments spaced apart. That is, along the winding direction y, there is a distance between the two closest ends of adjacent segments of the first sub-electrodes 31.

[0128] In some embodiments, the first sub-electrode 31 can be understood as follows: after coating the coating area of ​​the current collector with an active material and forming an electrode roll, the electrode roll is divided into multiple units by a slitting process, and each unit is a segment of the first sub-electrode 31.

[0129] In some embodiments, the arrangement of multiple first sub-electrodes 31 at intervals can be understood as follows: along the winding direction y, adjacent first sub-electrodes 31 are not directly connected; for example, a gap may be formed between them.

[0130] Optionally, in the cylindrical battery cell 10, a gap is formed between two adjacent first sub-electrode segments 31, and the gap contains electrolyte.

[0131] In some embodiments, two adjacent segments of the first sub-electrode 31 are held and fixed by two adjacent layers of the separator 50. Exemplarily, during the winding process, multiple segments of the first sub-electrode 31 are arranged at intervals on the separator 50, and the second electrode 40, the separator 50, and the multiple segments of the first sub-electrode 31 are wound together about the winding axis.

[0132] Optionally, in the cylindrical battery cell 10, adjacent first sub-electrode segments 31 are connected by other structural components. These other structural components can be dissolved under certain conditions, thereby creating a gap between the adjacent first sub-electrode segments 31. The certain conditions may refer to a certain temperature or conditions of being immersed in electrolyte.

[0133] Each segment of the first sub-electrode 31 has a first tab 32 on the same side along the winding axis z. The first tab 32 is used to electrically connect with the first electrode lead-out member 60 to realize the input or output of electrical energy. The first tab 32 can be an empty foil area of ​​the current collector of the first sub-electrode 31, or the first tab 32 can be a structural component that can be connected to the current collector of the first sub-electrode 31.

[0134] In the electrode assembly 12, a plurality of first tabs 32 can be bent toward the direction of the winding axis and stacked on top of each other to form a smoothing structure or a kneading structure.

[0135] In some embodiments, the end of the first tab 32 may be partially cut off along the winding direction y, so that the edge of the first tab 32 is inclined and the outline of the first tab 32 is trapezoidal, thereby reducing the risk of interference and folding when two adjacent first tabs 32 are bent in the direction of the winding axis. For example, the end of the first tab 32 may be cut off at an angle of greater than or equal to 60° along the winding direction y.

[0136] Along the winding axis direction z, the first electrode lead-out member 60 is disposed on the same side as a plurality of first electrode tabs 32, and the first electrode lead-out member 60 is electrically connected to all the first electrode tabs 32.

[0137] In some embodiments, the first electrode lead-out member 60 may include a first electrode terminal 62, which may be disposed on the wall of the housing 11. For example, the first electrode terminal may be disposed insulatedly on the end wall of the housing.

[0138] In some embodiments, the first electrode lead 60 may include a wall portion of the housing 11; exemplarily, the first electrode lead may include a cover.

[0139] In some embodiments, the first electrode lead-out member 60 may include a first current collector 61 disposed within the housing 11. Optionally, the first current collector 61 may be in other shapes such as disc, sheet, or strip. Optionally, the first current collector 61 may be made of metal, including but not limited to copper, iron, aluminum, steel, or aluminum alloys.

[0140] In some embodiments where the first electrode lead-out member 60 includes the first current collector 61, the first electrode tab 32 of each segment of the first sub-electrode 31 can be welded to the first current collector 61 respectively, or the first electrode tabs 32 of multiple segments of the first sub-electrode 31 can be pre-welded together and then welded to the first current collector 61.

[0141] The first electrode 30 has a multi-segment structure, and the first electrode 30 includes multiple first sub-electrodes 31. Along the winding direction, the multiple first sub-electrodes 31 can have the same or different dimensions.

[0142] For example, the first electrode 30 includes two first sub-electrodes 31, which have the same size along the winding direction.

[0143] For example, the first electrode 30 includes two first sub-electrodes 31, one of which is closer to the winding axis and has a smaller dimension along the winding direction than the other of which is farther from the winding axis.

[0144] In the above scheme, the first electrode 30 has a multi-segment structure, and multiple first sub-electrodes 31 of the first electrode 30 are intermittently arranged along the winding direction y. Each first sub-electrode 31 is connected to the first electrode lead 60 through a corresponding first electrode tab 32. On the one hand, the gap between two adjacent first sub-electrodes 31 is a reserved space for the expansion of the electrode assembly 12, thereby releasing the internal stress of the electrode assembly 12 and reducing the risk of the electrode breaking due to stress concentration, so that the cylindrical battery cell 10 has high reliability. On the other hand, the multiple first sub-electrodes 31 are connected in parallel, shortening the current path between the electrode assembly 12 and the first electrode lead 60, effectively reducing the internal resistance of the electrode assembly 12, so that the cylindrical battery cell 10 has high charge and discharge performance, and thus the battery device 100 has high reliability and charge and discharge performance.

[0145] According to some embodiments of this application, along the winding direction y, the sum of the lengths of all the first sub-electrodes 31 is H1, and the sum of the dimensions of the gaps between all the first sub-electrodes 31 is H2, satisfying that 0.001≤H2 / (H1+H2)≤0.05.

[0146] The sum of the lengths of all the first sub-electrodes 31 along the winding direction y is H1.

[0147] In some embodiments, a gap exists between two adjacent first sub-electrodes 31 along the winding direction y. In the electrode assembly 12, the number of first sub-electrodes 31 can be two, three, or more. When the number of first sub-electrodes 31 is three or more, the number of gaps is two or more, and the sum of the dimensions of all gaps along the winding direction y is H2. Optionally, the dimensions of each gap along the winding direction y can be the same or different. For example, along the winding direction y, the gaps further away from the winding axis can have larger dimensions.

[0148] Optionally, the sum of the lengths H1 of all the first sub-electrodes 31 along the winding direction y can be measured by cutting the cylindrical battery cell 10 along the direction z perpendicular to the winding axis to obtain the cross-section of the electrode assembly 12, directly measuring the dimensions of multiple segments of the first sub-electrodes 31, and adding the multiple data to obtain H1. Alternatively, the electrode assembly 12 can be unfolded to obtain multiple segments of the first sub-electrodes 31, and the dimensions of the multiple segments of the first sub-electrodes 31 can be directly measured, and the multiple data can be added to obtain H1.

[0149] Optionally, the sum of the dimensions H2 of all gaps along the winding direction y can be measured by the following method: The electrolyte is released, and the cylindrical battery cell 10 is cut along a direction perpendicular to the winding axis z to obtain the cross-section of the electrode assembly 12. A soft test piece (e.g., a silicone sheet, plastic sheet, etc.) is filled into the gap between two adjacent segments of the first sub-electrode 31. The end of the soft test piece contacts the end of the first sub-electrode 31, and the winding curvature of the soft test piece adapts to the winding curvature of the first sub-electrode 31. The dimensions of the soft test piece are directly measured to obtain H1. For example, in… Figure 6 The soft test piece is marked with a dashed line. Alternatively, the separator 50 and the first sub-electrode 31 are fixed, the electrode assembly 12 is unfolded to obtain multiple segments of the first sub-electrode 31 arranged at intervals, and the distance between two adjacent first sub-electrode 31 is directly measured to obtain H1.

[0150] In some embodiments, H1 and H2 satisfy the following relationship: 0.001≤H2 / (H1+H2)≤0.05, that is, the value of H2 / (H1+H2) can be 0.001, 0.002, 0.003, 0.004…0.047, 0.048, 0.049, 0.05 or any value between two adjacent values.

[0151] Optionally, 0.008≤H2 / (H1+H2)≤0.01, that is, the value of H2 / (H1+H2) can be 0.008, 0.009, 0.01 or any value between two adjacent values.

[0152] In some embodiments, based on the related art where the first electrode in a cylindrical battery cell is a single structure rather than a multi-segment structure, in some embodiments of this application, the first electrode 30 includes two first sub-electrodes 31, and the gap between the two first sub-electrodes 31 along the winding direction y, the dimension H2, can be from 0.1 mm to 5 mm. Optionally, the gap between the two first sub-electrodes 31 along the winding direction y, the dimension H2, can be 1 mm.

[0153] In the above scheme, by limiting the relationship between the size of the gap between the first sub-electrodes 31 and the size of the first sub-electrodes 31, it is possible to take into account that the first electrode 30 with a multi-segment structure provides a certain reserved space for the expansion of the electrode assembly 12, reduce the risk of stress concentration inside the wound electrode assembly 12 leading to electrode breakage, and reduce the risk of the volumetric energy density being affected by the reduction of active material inside the cylindrical battery cell 10 due to excessively large gap size, thereby enabling the battery device 100 to have higher reliability and volumetric energy density.

[0154] In some embodiments, the value of H2 / (H1+H2) satisfies the above-mentioned limitations, which is beneficial to the release of stress on the inner electrode. However, if H2 / (H1+H2) is too large, it may also cause the risk of stress rebound on the outer ring, as well as the risk of uneven electrolyte distribution under high temperature conditions, which may lead to damage to the internal structure of the cylindrical battery cell and failure.

[0155] According to some embodiments of this application, the first electrode 30 includes adjacent inner ring first sub-electrode 31a and outer ring first sub-electrode 31b. The terminal end of the inner ring first sub-electrode 31a is closer to the winding axis of the electrode assembly 12 than the terminal end of the outer ring first sub-electrode 31b. On the same projection plane perpendicular to the winding axis direction z, the line connecting the orthographic projection of the terminal end of the inner ring first sub-electrode 31a and the orthographic projection of the winding axis is the first line, and the line connecting the orthographic projection of the terminal end of the outer ring first sub-electrode 31b and the orthographic projection of the winding axis is the second line. The angle between the first line and the second line is greater than or equal to 0° and less than or equal to 20°.

[0156] Along the winding direction y, the first sub-electrode 31 has a starting end close to the winding axis and a ending end away from the winding axis.

[0157] Along the winding direction y, the first electrode 30 includes an inner first sub-electrode 31a and an outer first sub-electrode 31b, with the inner first sub-electrode 31a being closer to the winding axis than the outer first sub-electrode 31b. On the same projection plane perpendicular to the winding axis direction z, the line connecting the orthographic projection of the end of the inner first sub-electrode 31a and the orthographic projection of the winding axis is defined as the first line, and the line connecting the orthographic projection of the end of the outer first sub-electrode 31b and the orthographic projection of the winding axis is defined as the second line. The angle α between the first and second lines can be 0, 1°, 2°, 3°, 4°, 5°…18°, 19°, 20°, or any value between two adjacent values. Optionally, the angle α between the first and second lines can be 0, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, or any value between two adjacent values.

[0158] For example, please see Figure 9 The first electrode 30 includes two first sub-electrodes 31, with a gap between the two first sub-electrodes 31. Along the radial direction of the electrode assembly 12, the ends of the two first sub-electrodes 31 almost overlap, and the angle between them is greater than or equal to 0 and less than or equal to 10°.

[0159] In the above scheme, by setting the deviation angle of the end of the two adjacent first sub-electrode sheets 31 about the winding axis to less than 20°, the electrode assembly 12 can have a high roundness, which is conducive to improving the efficiency of the electrode assembly 12 in the casing and making the cylindrical battery cell 10 have a high manufacturing efficiency.

[0160] According to some embodiments of this application, please refer to Figure 7 , Figure 7 This is a schematic diagram of the electrode assembly 12 and the first current collector 61 provided in some embodiments of this application. The first electrode lead-out member 60 includes the first current collector 61, which is located inside the housing 11. The first electrode tab 32 is connected to the first current collector 61 via a solder joint 610.

[0161] In some embodiments, the first current collector 61 may be a current collector plate. The first current collector 61 is located inside the housing 11, and the first electrode tab 32 is electrically connected to the electrode terminal or the housing through the first current collector 61.

[0162] In some embodiments, the first electrode tab 32 is welded to the first current collector 61 to form a solder mark 610. Optionally, the first electrode tab 32 and the first current collector 61 are welded together by ultrasonic welding or laser welding.

[0163] In the above scheme, each first tab 32 is connected to the first current collector 61 through the soldering part 610, so that each first sub-electrode 31 and the first current collector 61 have a stable physical connection and electrical connection, reducing the risk of breakage between the first sub-electrode 31 and the first current collector 61, which is beneficial to improving the charging and discharging performance of the cylindrical battery cell 10.

[0164] According to some embodiments of this application, on the same projection plane perpendicular to the winding axis direction z, there is an overlapping area between the orthographic projection of each segment of the first tab 32 and the orthographic projection of the first current collector 61.

[0165] When viewed along the winding axis, each first tab 32 and the first current collector 61 have an overlapping area.

[0166] For example, after the first electrode tab 32 of the outermost first sub-electrode 31 is bent, the distance between the free end of the first electrode tab 32 and the winding axis is less than the distance between the outer periphery of the first current collector 61 and the winding axis. After the first electrode tab 32 of the innermost first sub-electrode 31 is bent, the distance between the free end of the first electrode tab 32 and the winding axis is greater than the distance between the inner periphery of the first current collector 61 and the winding axis.

[0167] In the above scheme, each segment of the first tab 32 overlaps with the first current collector 61, which can reduce the risk of no direct overcurrent between the innermost or outermost first tab 32 and the first current collector 61, so that there is a shorter current path between each segment of the first sub-electrode 31 and the first current collector 61 in the electrode assembly 12, effectively reducing the internal resistance of the electrode assembly 12, so that the cylindrical battery cell 10 has high charge and discharge performance, and thus the battery device 100 has high reliability and charge and discharge performance.

[0168] According to some embodiments of this application, on the same projection plane perpendicular to the winding axis direction z, the orthographic projection of each segment of the first sub-electrode 31 and the orthographic projection of the first current collector 61 have overlapping areas.

[0169] When viewed along the winding axis, there is an overlapping area between the first sub-pole plate 31 and the first current collector 61 in each segment.

[0170] For example, the distance between the starting end of the outermost first sub-electrode 31 and the winding axis is less than the distance between the outer periphery of the first current collector 61 and the winding axis, and the distance between the ending end of the innermost first sub-electrode 31 and the winding axis is greater than the distance between the inner periphery of the first current collector 61 and the winding axis.

[0171] In the above scheme, each segment of the first sub-electrode 31 overlaps with the first current collector 61, which can reduce the risk of no direct overcurrent between the first sub-electrode 31 and the first current collector 61 due to the discontinuous arrangement between the first sub-electrode 31 and the first current collector 61. This results in a shorter current path between each segment of the first sub-electrode 31 and the first current collector 61 in the electrode assembly 12, effectively reducing the internal resistance of the electrode assembly 12. This allows the cylindrical battery cell 10 to have higher charge and discharge performance, thereby enabling the battery device 100 to have higher reliability and charge and discharge performance.

[0172] According to some embodiments of this application, please refer to Figure 8 and Figure 9 , Figure 8 This is a schematic diagram of the structure of the electrode assembly 12 in some embodiments of this application. Figure 9 for Figure 8 Enlarged view of point A in the middle.

[0173] The cylindrical battery cell 10 also includes an electrolyte and a first connector 70, with the electrolyte disposed inside the housing 11. Adjacent first sub-electrode segments 31 are connected by the first connector 70, which is soluble in the electrolyte.

[0174] In some embodiments, two adjacent first sub-electrode segments 31 are connected by a first connector 70. Exemplarily, before the electrode assembly 12 is wound, the first connector 70 is connected to the first sub-electrode segments 31, and the multiple first sub-electrode segments 31 and the first connector 70 constitute an integral structure. This integral structure, the separator 50, and the second electrode 40 are wound together about the winding axis to form the electrode assembly 12.

[0175] The first connector 70 is a structural component that is soluble in electrolyte, and its manufacturing material includes materials that are soluble in electrolyte.

[0176] The connection between the first connector 70 and the first sub-electrode 31 is varied, including but not limited to bonding, snap-fitting, riveting, etc.

[0177] In the above scheme, the two adjacent first sub-electrode sections 31 are connected by the first connector 70, which can reduce the winding difficulty of the first sub-electrode 31 and improve the manufacturing efficiency of the electrode assembly 12. When the electrode assembly 12 is inserted into the shell and the electrolyte is injected into the shell 11, the first connector 70 is dissolved after being soaked in the electrolyte, which can release the reserved space for the expansion of the electrode assembly 12, reduce the risk of electrode breakage caused by stress concentration inside the electrode assembly 12, and make the cylindrical battery cell 10 have high reliability and manufacturing efficiency, thereby making the battery device 100 have high reliability and manufacturing efficiency.

[0178] According to some embodiments of this application, please refer to Figure 8 The first connector 70 between two adjacent first sub-electrode segments 31 is wound at least once.

[0179] The starting end of the first connector 70 is connected to the ending end of the inner ring first sub-electrode 31a, and the ending end of the first connector 70 is connected to the starting end of the outer ring first sub-electrode 31b.

[0180] In some embodiments, the first connector 70 is wound around the first sub-electrode 31 about the winding axis. The first connector 70 being wound at least one turn can be understood as the starting end and the ending end of the first connector 70 coinciding with each other or having an overlapping area along the radial direction of the electrode assembly 12.

[0181] In the above scheme, by winding the first connector 70 between the two first sub-electrodes 31 at least one turn, a reserved space is provided for the electrode assembly 12 after the first connector 70 is dissolved, absorbing the expansion force in any direction around the electrode assembly 12, effectively reducing the risk of electrode breakage caused by stress concentration inside the electrode assembly 12, making the cylindrical battery cell 10 highly reliable, and thus making the battery device 100 highly reliable.

[0182] According to some embodiments of this application, the first connector 70 is bonded to the first sub-electrode 31.

[0183] Along the winding direction y, the two ends of the first connector 70 are respectively bonded to the ends of the two adjacent first sub-electrode plates 31.

[0184] For example, an adhesive is provided at the end of the first connector 70, and the first connector 70 is connected to the first sub-electrode 31 through the adhesive. After the adhesive dries, an adhesive layer 72 is formed.

[0185] In the above scheme, the first connector 70 is bonded to the first sub-electrode 31, which can reduce the connection difficulty between the first connector 70 and the first sub-electrode 31, which is conducive to improving the manufacturing efficiency of the electrode assembly 12, and thus conducive to improving the manufacturing efficiency of the cylindrical battery cell 10 and the battery device 100.

[0186] According to some embodiments of this application, the first connector 70 includes a base layer 71 and an adhesive layer 72, the adhesive layer 72 being disposed on the base layer 71. The base layer 71 is made of materials including polycaprolactone, polycarbonate, polycarbonate-type polyurethane, or polyethylene oxide. The adhesive layer 72 is made of materials including polycarbonate-type polyurethane, biodegradable segmental acrylate copolymer, polycaprolactone, polyether-polyurethane block copolymer, polyethylene oxide, or polyether-acrylate block copolymer.

[0187] Please see Figure 10 , Figure 10 This is a schematic diagram of the structure of a first connector 70 provided in some embodiments of this application. The first connector 70 includes a base layer 71 and an adhesive layer 72. The base layer 71 is the main part of the first connector 70 and has the function of supporting the adhesive layer 72. The adhesive layer 72 is disposed on one side of the base layer 71 along its thickness direction, and the base layer 71 is connected to the first sub-electrode 31 through the adhesive layer 72. Along the winding direction y, the size of the adhesive layer 72 can be less than or equal to the size of the base layer 71.

[0188] In some embodiments, the material of the base layer 71 may be soluble in the electrolyte, and the material of the base layer 71 includes at least one of polycaprolactone, polycarbonate, polycarbonate-type polyurethane, or polyethylene oxide.

[0189] In some embodiments, the material of the adhesive layer 72 may be soluble in the electrolyte, and the material of the adhesive layer 72 includes at least one of polycarbonate polyurethane, biodegradable segment acrylate copolymer, polycaprolactone, polyether-polyurethane block copolymer, polyethylene oxide, or polyether-acrylate block copolymer.

[0190] In the above scheme, the first connector 70 includes a base layer 71 and an adhesive layer 72. The base layer 71 is bonded to the first sub-electrode 31 through the adhesive layer 72. By setting the materials of the base layer 71 and the adhesive layer 72 to be materials that can be dissolved by the electrolyte, the first connector 70 can be dissolved after the electrode assembly 12 is installed in the shell and wetted by the electrolyte. This releases the space reserved for expansion between the two sections of the first sub-electrode 31, reducing the risk of electrode breakage caused by stress concentration inside the electrode assembly 12, and making the cylindrical battery cell 10 and the battery device 100 have high reliability.

[0191] According to some embodiments of this application, please refer to Figure 11 and Figure 12 , Figure 11This is a schematic diagram of the structure of the first sub-electrode 31, the first protective member 80, and the first connecting member 70 provided in some embodiments of this application. Figure 12 for Figure 11 Enlarged view of point B in the middle.

[0192] The battery cell also includes a first protective member 80, which is connected to at least one side of the first sub-electrode 31 along its thickness direction. A first connector 70 is connected to the side of the first protective member 80 opposite to the first sub-electrode 31.

[0193] In some embodiments, along the winding direction y, the end of the first sub-electrode 31 is provided with a first protective member 80, and the first protective member 80 is connected to at least one side of the first sub-electrode 31 along its thickness direction.

[0194] Optionally, the first protective member 80 is connected to one side of the first sub-electrode 31 along its thickness direction.

[0195] Optionally, the first protective member 80 is connected to both sides of the first sub-electrode 31 along its thickness direction.

[0196] Optionally, the first protective element 80 covers the end of the first sub-electrode 31.

[0197] In some embodiments, the first protective element 80 may be adhered to the first sub-electrode 31, and the first protective element 80 may include an insulating material. Optionally, the first protective element 80 may include blue adhesive.

[0198] The connection relationship between the first connector 70 and the first protective member 80 is varied, including but not limited to bonding, snap-fitting, riveting, etc.

[0199] In some embodiments, the first sub-electrode 31 includes a current collector 310 and an active material layer 311. The active material layer 311 may be coated on at least one side of the current collector 310 in the thickness direction, and the first protective member 80 may be connected to the surface of the active material layer 311 away from the current collector 310.

[0200] Compared to the solution where the first connector 70 is directly connected to the first sub-electrode 31, in the above solution, after the first connector 70 is dissolved, the first protective member 80 can protect the end of the first sub-electrode 31, reducing the risk of positive and negative electrodes colliding due to burrs generated during processing piercing the separator 50 at the connection between the first sub-electrode 31 and the first connector 70. This results in higher reliability for the cylindrical battery cell 10 and the battery device 100.

[0201] According to some embodiments of this application, the first protective member 80 includes a first protective film 81 and a second protective film 82. One end of the first protective film 81 and one end of the second protective film 82 are respectively connected to both sides of the first sub-electrode 31 along the thickness direction, and the other end of the first protective film 81 and the other end of the second protective film 82 are connected.

[0202] In some embodiments, the first protective member 80 includes a first protective film 81 and a second protective film 82. One end of the first protective film 81 and one end of the second protective film 82 are respectively bonded to both sides of the first sub-electrode 31, and the other ends of the first protective film 81 and the other ends of the second protective film 82 are connected to each other.

[0203] In the above scheme, the first protective film 81 and the second protective film 82 are respectively connected to both sides of the first sub-electrode 31 along its thickness direction. On the one hand, this enables a stable connection between the first sub-electrode 31, the first protective member 80 and the first connecting member 70, which is beneficial for the winding and forming of the electrode assembly 12 and reduces the risk of the first sub-electrode 31 separating during the winding process, affecting the yield of the electrode assembly 12. This results in higher manufacturing efficiency for the cylindrical battery cell 10 and the power device. On the other hand, this effectively shields the burrs generated at the ends of the first sub-electrode 31 due to cutting, reducing the risk of burrs piercing the separator 50 and ensuring higher reliability for the cylindrical battery cell 10 and the battery device 100.

[0204] According to some embodiments of this application, the first connector 70 is connected to at least one of the first protective film 81 and the second protective film 82.

[0205] Optionally, the first connector 70 is connected to one of the first protective film 81 and the second protective film 82.

[0206] Optionally, the first connector 70 is connected to the first protective film 81 and the second protective film 82.

[0207] For example, the first connector 70 is a double-layer structure, including a first layer connector and a second layer connector that are connected to each other. The first layer connector is connected to the side of the first protective film 81 that is away from the first sub-electrode 31, and the second layer connector is connected to the side of the second protective film 82 that is away from the first sub-electrode 31.

[0208] In the above scheme, the first connector 70 is connected to at least one of the first protective film 81 and the second protective film 82, so that the first connector 70 is stably connected to the first sub-tab through the first protective film 80, which is beneficial to the efficiency of the winding and forming of the electrode assembly 12, and facilitates the insertion of the electrode assembly 12 into the shell, so that the cylindrical battery cell 10 has high manufacturing efficiency.

[0209] According to some embodiments of this application, on the same projection plane perpendicular to the thickness direction, the orthographic projection of the first connector 70, the orthographic projection of the first protective member 80, and the orthographic projection of the first sub-electrode 31 have an overlapping area. Along the winding direction y, the width of the overlapping area is greater than 1 mm and less than or equal to the width of the first protective member 80.

[0210] Please see Figure 12 On the same projection plane perpendicular to the thickness direction of the first sub-electrode 31, the orthographic projections of the first connecting member 70, the first protective member 80, and the first sub-electrode 31 overlap. The width D of this overlapping area along the winding direction y can be greater than 1 mm and less than the width of the first protective member 80. That is, the width of the overlapping area between the orthographic projections of the first protective member 80 and the first sub-electrode 31 is greater than or equal to 1 mm.

[0211] In the above scheme, the overlap width of the first connector 70, the first protective member 80, and the first sub-electrode 31 is limited to be greater than or equal to 1 mm, so that the first connector 70 and the first protective member 80 have a reliable connection relationship, which is beneficial to the efficiency of the winding and forming of the electrode assembly 12 and facilitates the insertion of the electrode assembly 12 into the shell, thereby enabling the cylindrical battery cell 10 to have higher manufacturing efficiency. The overlap width of the first connector 70 and the first protective member 80 is limited to be less than or equal to the width of the first protective member 80, which can reduce the risk that the thickness difference between two adjacent turns of the first sub-electrode 31 will be too large due to the excessive connection size of the first connector 70 and the first protective member 80, thus affecting the roundness of the electrode assembly 12, thereby enabling the electrode assembly 12 to have higher roundness, which facilitates the insertion of the electrode assembly 12 into the shell, and enables the cylindrical battery cell 10 to have higher manufacturing efficiency.

[0212] According to some embodiments of this application, the second electrode 40 includes multiple segments of second sub-electrodes 41 arranged discontinuously along the winding direction y, and each segment of the second sub-electrodes 41 is provided with a second tab 42 on one side along the winding axis direction z. The cylindrical battery cell 10 also includes a second electrode lead 90, which is located on the side of the electrode assembly 12 opposite to the first electrode lead 60 along the winding axis direction z, and the second tab 42 of each segment of the second sub-electrodes 41 is electrically connected to the second electrode lead 90.

[0213] The second electrode 40 has a multi-segment structure, comprising multiple second sub-electrodes 41. The number of second sub-electrodes 41 can be two, three, or more. Along the winding direction y, the multiple second sub-electrodes 41 are arranged at intervals, with adjacent segments spaced apart. That is, along the winding direction y, there is a distance between the two closest ends of adjacent segments of the second sub-electrodes 41.

[0214] In some embodiments, the second sub-electrode 41 can be understood as follows: after coating the coating area of ​​the current collector with an active material and forming an electrode roll, the electrode roll is divided into multiple units by a slitting process, and each unit is a segment of the second sub-electrode 41.

[0215] In some embodiments, the multiple segments of second sub-electrode 41 are arranged at intervals, which can be understood as the fact that, along the winding direction y, adjacent segments of second sub-electrode 41 are not directly connected, for example, a gap may be formed between them.

[0216] Optionally, in the cylindrical battery cell 10, a gap is formed between two adjacent second sub-electrode segments 41, and the gap contains electrolyte.

[0217] In some embodiments, two adjacent segments of the second sub-electrode 41 are held and fixed by two adjacent layers of the separator 50. Exemplarily, during the winding process, multiple segments of the second sub-electrode 41 are arranged at intervals on the separator 50, and multiple segments of the first sub-electrode 31, the separator 50 and the multiple segments of the second sub-electrode 41 are wound together about the winding axis.

[0218] Optionally, in the cylindrical battery cell 10, adjacent second sub-electrode segments 41 are connected by other structural components. These other structural components can be dissolved under certain conditions, thereby creating a gap between the adjacent second sub-electrode segments 41. These certain conditions can refer to a specific temperature or the condition of being immersed in electrolyte.

[0219] Each segment of the second sub-electrode 41 has a second tab 42 on the same side along the winding axis z. The second tab 42 is used to electrically connect with the second electrode lead-out member 90 to realize the input or output of electrical energy. The second tab 42 can be an empty foil area of ​​the current collector of the second sub-electrode 41, or the second tab 42 can be a structural component that can be connected to the current collector of the second sub-electrode 41.

[0220] In the electrode assembly 12, multiple second tabs 42 can be bent toward the direction of the winding axis and stacked on top of each other to form a smoothing structure or a kneading structure.

[0221] In some embodiments, the end of the second tab 42 may be partially cut off along the winding direction y, so that the edge of the second tab 42 is inclined and the outline of the second tab 42 is trapezoidal, thereby reducing the risk of interference and folding when two adjacent first tabs 32 are bent in the direction of the winding axis. For example, the end of the second tab 42 may be cut off at an angle of greater than or equal to 60° along the winding direction y.

[0222] Along the winding axis, the first tab 32 and the second tab 42 are located on opposite sides of the electrode assembly 12.

[0223] Along the winding axis direction z, the second electrode lead-out member 90 is disposed on the same side as a plurality of second electrode tabs 42, and the second electrode lead-out member 90 is electrically connected to all the second electrode tabs 42.

[0224] In some embodiments, the second electrode lead-out member 90 may include a second electrode terminal, which may be disposed on the wall of the housing 11. Exemplarily, the second electrode terminal may be insulatedly disposed on the end wall of the housing.

[0225] In some embodiments, the second electrode lead 90 may include a wall portion of the housing 11; exemplarily, the second electrode lead may include a cover.

[0226] In some embodiments, the second electrode lead-out 90 may include a second current collector disposed within the housing 11. Optionally, the second current collector may be in other shapes such as disc, sheet, or strip. Optionally, the second current collector may be made of metal, including but not limited to copper, iron, aluminum, steel, or aluminum alloys.

[0227] In some embodiments where the second electrode lead-out member 90 includes the first current collector member 61, the second electrode tab 42 of each segment of the second sub-electrode 41 can be welded to the second current collector member respectively, or the second electrode tabs 42 of multiple segments of the second sub-electrode 41 can be pre-welded together and then welded to the second current collector member.

[0228] In the above scheme, the second electrode 40 has a multi-segment structure, and the multiple segments of the second sub-electrode 41 of the second electrode 40 are arranged intermittently along the winding direction y. Each segment of the second sub-electrode 41 is connected to the second electrode lead 90 through a corresponding second electrode tab 42. On the one hand, the gap between two adjacent segments of the second sub-electrode 41 is a reserved space for the expansion of the electrode assembly 12, thereby releasing the internal stress of the electrode assembly 12 and reducing the risk of the electrode breaking due to stress concentration, so that the cylindrical battery cell 10 has high reliability. On the other hand, the multiple segments of the second sub-electrode 41 are connected in parallel, which shortens the current path between the electrode assembly 12 and the second electrode lead 90, effectively reducing the internal resistance of the electrode assembly 12, so that the cylindrical battery cell 10 has high charge and discharge performance, and thus the battery device 100 has high reliability and charge and discharge performance.

[0229] Some embodiments of this application also provide a battery device 100, please refer to [link to relevant documentation]. Figure 2 The battery device 100 includes cylindrical battery cells 10.

[0230] For example, the battery device 100 includes a housing 20 and cylindrical battery cells 10, the cylindrical battery cells 10 being housed within the housing 20. In the battery device 100, there may be one or more cylindrical battery cells 10 disposed within the housing 20. When there are multiple cylindrical battery cells 10 disposed within the housing 20, the multiple cylindrical battery cells 10 may be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that some of the multiple cylindrical battery cells 10 are connected in series and others in parallel.

[0231] Some embodiments of this application also provide an electrical device; please refer to [link / reference]. Figure 1 The electrical device includes a cylindrical battery cell 10 or a battery device 100.

[0232] For example, the electrical device is a vehicle 1000, and the cylindrical battery cell 10 and / or battery device 100 can serve as the operating power source for the vehicle 1000, for example, for the power requirements of the vehicle 1000 during startup, navigation and operation.

[0233] This application provides a cylindrical battery cell 10. Please refer to [link to relevant documentation]. Figures 3-12 .

[0234] The cylindrical battery cell 10 includes a casing 11, an electrode assembly 12, an electrolyte, a first electrode lead 60, and a second electrode lead. Both the electrode assembly 12 and the electrolyte are housed within the casing 11. The electrode assembly 12 has a wound structure and includes a first electrode 30, a separator 50, and a second electrode 40. The separator 50 is disposed between the first electrode 30 and the second electrode 40, and the first electrode 30 and the second electrode 40 have opposite polarities. The first electrode 30 has a multi-segment structure, including multiple segments of first sub-electrodes 31 arranged discontinuously along the winding direction y. Each segment of the first sub-electrode 31 has a first tab 32 on one side along the winding axis direction z.

[0235] Optionally, along the winding direction y, the sum of the lengths of all the first sub-electrodes 31 is H1, the sum of the dimensions of the gaps between all the first sub-electrodes 31 is H2, and the value of H2 / (H1+H2) can be 0.01.

[0236] Optionally, the first electrode 30 includes two first sub-electrodes 31, with a gap of 1 mm between the two first sub-electrodes 31.

[0237] The second electrode 40 has a multi-segment structure, including multiple segments of second sub-electrode 41 arranged discontinuously along the winding direction y. Each segment of the second sub-electrode 41 has a second electrode tab 42 on one side along the winding axis direction z. Along the winding axis direction z, the lead-out directions of the first electrode tab 32 and the second electrode tab 42 are opposite.

[0238] The first electrode lead-out member 60 includes a first current collector 61, which is located inside the housing 11 and along the winding axis direction z. The first current collector 61 and the first electrode tab 32 are arranged on the same side. The first electrode tab 32 of each segment of the first sub-electrode 31 is electrically connected to the first current collector 61.

[0239] The second electrode lead-out member 90 includes a second current collector, which is located inside the housing 11 and along the winding axis direction z. The second current collector and the second electrode tab 42 are arranged on the same side. The second electrode tab 42 of each segment of the second sub-electrode 41 is electrically connected to the first current collector 61.

[0240] In some embodiments, two adjacent segments of the first sub-electrode 31 are connected by a first connector 70 along the winding direction y, and the first connector 70 is soluble in the electrolyte.

[0241] Optionally, the first connector 70 is a layered or sheet-like structure, comprising a base layer 71 and an adhesive layer 72 disposed on the surface of the base layer 71. Both the base layer 71 and the adhesive layer 72 are made of materials that can dissolve in the electrolyte.

[0242] Optionally, the first sub-electrode 31 can be obtained by slitting electrode rolls. To reduce the risk of burrs at the end of the first sub-electrode 31 puncturing the separator 50, a first protective member 80 can be provided at the end of the first sub-electrode 31. The first protective member 80 can be an insulating structure, such as a finishing adhesive. The first connector 70 can be bonded to the first protective member 80 to connect two adjacent sections of the first sub-electrode 31.

[0243] In some embodiments, adjacent segments of the second sub-electrode 41 are connected by a second connector along the winding direction y, and the second connector is soluble in the electrolyte.

[0244] In the above scheme, both the first electrode 30 and the second electrode 40 are multi-segment structures. The first electrode 30 has multiple segments of first sub-electrodes 31 arranged discontinuously along the winding direction y, and the first sub-electrodes 31 are connected by a first connector 70 that is soluble in the electrolyte. Similarly, the second electrode 40 has multiple segments of second sub-electrodes 41 arranged discontinuously along the winding direction y, and the second sub-electrodes 41 are connected by a second connector that is soluble in the electrolyte. After the connector dissolves in the electrolyte, the gap between adjacent segments of the first sub-electrodes 31 provides space for the expansion of the electrode assembly 12, thereby releasing the internal stress of the electrode assembly 12, reducing the risk of electrode breakage due to stress concentration, and enabling the cylindrical battery cell 10 to have high reliability. Meanwhile, the first tab 32 of each first sub-electrode 31 is electrically connected to the first current collector 61, and the second tab 42 of each second sub-electrode 41 is electrically connected to the second current collector, so that multiple first sub-electrodes 31 are connected in parallel and multiple second sub-electrodes 41 are connected in parallel, thereby shortening the current path between the electrode assembly 12 and the first current collector 61 and the second current collector, effectively reducing the internal resistance of the electrode assembly 12, so that the cylindrical battery cell 10 has high charge and discharge performance, and thus the battery device 100 has high reliability and charge and discharge performance.

[0245] In some embodiments, along the winding direction y, the sum of the lengths of all the first sub-electrodes 31 is H1, and the sum of the dimensions of the gaps between all the first sub-electrodes 31 is H2, satisfying 0.001≤H2 / (H1+H2)≤0.05. The value of H2 / (H1+H2) can be 0.001, 0.002, 0.003, 0.004…0.047, 0.048, 0.049, 0.05 or any value between two adjacent values.

[0246] In some embodiments, a comparison is made between a single electrode and the multi-segment electrode described above.

[0247] Example

[0248] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0249] Example 1

[0250] Example 1 is the cylindrical battery provided above. The first electrode 30 has a multi-segment structure, including multiple segments of first sub-electrodes 31 arranged discontinuously along the winding direction y. Along the winding direction y, the sum of the lengths of all the first sub-electrodes 31 is H1, and the sum of the dimensions of the gaps between all the first sub-electrodes 31 is H2. The value of H2 / (H1+H2) is 0.002.

[0251] Example 2

[0252] The difference between Example 2 and Example 1 is that the value of H2 / (H1+H2) is 0.01.

[0253] Example 3

[0254] The difference between Example 3 and Example 1 is that the value of H2 / (H1+H2) is 0.05.

[0255] Comparative Example 1

[0256] The difference between Comparative Example 1 and Example 1 is that the first electrode is a single structural component, not a multi-segment structure.

[0257] In Examples 1-3 and Comparative Example 1, cylindrical battery cells with the same outer casing size are used. The difference between Examples 1-3 and Comparative Example 1 lies in the form of the first electrode, while other factors can be the same.

[0258] The cylindrical battery cells provided in Examples 1-3 and Comparative Example 1 were tested for the number of charge-discharge cycles under normal temperature (25℃) and high temperature (60℃) conditions according to GB / T 31486-2015, and the results are shown in Table 1.

[0259] Table 1

[0260]

[0261] In Table 1, the number of charge-discharge cycles to electrode breakage for cylindrical battery cells with a single electrode (non-multi-segment structure) at both room temperature (25℃) and high temperature (60℃) is less than that for cylindrical battery cells with a multi-segment electrode structure. In other words, setting the electrode to a multi-segment structure can effectively reduce the risk of electrode breakage due to stress concentration, thus giving cylindrical battery cells higher reliability.

[0262] Table 1 compares Examples 2 and 3 to illustrate that an excessively large H2 / (H1+H2) can also cause the risk of stress rebound in the outer ring, as well as the risk of uneven electrolyte distribution under high temperature conditions, which can lead to damage to the internal structure of the cylindrical battery cell and its failure.

[0263] In Table 1, among Examples 1-3, Example 2 is the preferred example, which has a longer service life and higher energy density.

[0264] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A cylindrical battery cell, characterized in that, include: shell; An electrode assembly is disposed within the housing. The electrode assembly has a wound structure and includes a first electrode, a separator, and a second electrode. The separator is disposed between the first electrode and the second electrode. The first electrode and the second electrode have opposite polarities. The first electrode includes multiple segments of first sub-electrodes arranged discontinuously along the winding direction. Each segment of the first sub-electrodes has a first tab on one side along the winding axis. The first electrode lead is located on one side of the electrode assembly along the winding axis, and the first electrode tab of each segment of the first sub-electrode is electrically connected to the first electrode lead.

2. The cylindrical battery cell according to claim 1, characterized in that, Along the winding direction, the sum of the lengths of all the first sub-electrodes is H1, and the sum of the dimensions of the gaps between all the first sub-electrodes is H2, satisfying that 0.001≤H2 / (H1+H2)≤0.

05.

3. The cylindrical battery cell according to claim 2, characterized in that, The condition is satisfied that 0.008≤H2 / (H1+H2)≤0.

01.

4. The cylindrical battery cell according to claim 1, characterized in that, The first electrode includes an inner ring first sub-electrode and an outer ring first sub-electrode, wherein the end of the inner ring first sub-electrode is closer to the winding axis of the electrode assembly than the end of the outer ring first sub-electrode. On the same projection plane perpendicular to the winding axis, the line connecting the orthographic projection of the end of the inner ring first sub-electrode and the orthographic projection of the winding axis is the first line, and the line connecting the orthographic projection of the end of the outer ring first sub-electrode and the orthographic projection of the winding axis is the second line. The angle between the first line and the second line is greater than or equal to 0° and less than or equal to 20°.

5. The cylindrical battery cell according to claim 1, characterized in that, The first electrode lead-out includes a first current collector, which is located inside the housing, and the first electrode tab is connected to the first current collector via a solder joint.

6. The cylindrical battery cell according to claim 5, characterized in that, On the same projection plane perpendicular to the winding axis, there is an overlapping area between the orthographic projection of each segment of the first tab and the orthographic projection of the first current collector.

7. The cylindrical battery cell according to claim 5, characterized in that, On the same projection plane perpendicular to the winding axis, there is an overlapping area between the orthographic projection of each segment of the first sub-electrode and the orthographic projection of the first current collector.

8. The cylindrical battery cell according to claim 1, characterized in that, The cylindrical battery cell further includes an electrolyte and a first connector, wherein the electrolyte is disposed inside the outer casing; The two adjacent segments of the first sub-electrode are connected by the first connector, which is soluble in the electrolyte.

9. The cylindrical battery cell according to claim 8, characterized in that, The first connector between two adjacent segments of the first sub-electrode is wound at least once.

10. The cylindrical battery cell according to claim 8, characterized in that, The first connector is bonded to the first sub-electrode.

11. The cylindrical battery cell according to claim 10, characterized in that, The first connector includes a base layer and an adhesive layer, wherein the adhesive layer is disposed on the base layer; The base material includes one of polycaprolactone, polycarbonate, polycarbonate-type polyurethane, and polyethylene oxide. The adhesive layer is made of one of the following materials: polycarbonate polyurethane, biodegradable segmental acrylate copolymer, polycaprolactone, polyether-polyurethane block copolymer, polyethylene oxide, and polyether-acrylate block copolymer.

12. The cylindrical battery cell according to claim 8, characterized in that, The battery cell further includes a first protective component, which is connected to at least one side of the first sub-electrode along its thickness direction. The first connector is connected to the side of the first protective member opposite to the first sub-electrode.

13. The cylindrical battery cell according to claim 12, characterized in that, The first protective element includes a first protective film and a second protective film. One end of the first protective film and one end of the second protective film are respectively connected to both sides of the first sub-electrode along the thickness direction, and the other end of the first protective film and the other end of the second protective film are connected.

14. The cylindrical battery cell according to claim 13, characterized in that, The first connector is connected to at least one of the first protective film and the second protective film.

15. The cylindrical battery cell according to claim 12, characterized in that, On the same projection plane perpendicular to the thickness direction, the orthographic projections of the first connector, the first protective member, and the first sub-electrode have an overlapping area. Along the winding direction, the width of the overlapping area is greater than 1 mm and less than or equal to the width of the first protective member.

16. The cylindrical battery cell according to any one of claims 1-15, characterized in that, The second electrode includes multiple segments of second sub-electrodes arranged discontinuously along the winding direction, and each segment of the second sub-electrodes has a second electrode tab on one side along the winding axis. The cylindrical battery cell further includes a second electrode lead, which is located on the side of the electrode assembly opposite to the first electrode lead along the winding axis. The second tab of each second sub-electrode is electrically connected to the second electrode lead.

17. A battery device, characterized in that, Includes the cylindrical battery cell as described in any one of claims 1-16.

18. An electrical appliance, characterized in that, Includes the cylindrical battery cell according to any one of claims 1-16, or the battery device according to claim 17.

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