Cylindrical battery monomer, battery device and power utilization device

Abstract

The utility model provides a cylindrical battery cell, a battery device and a power utilization device. A cylindrical battery cell includes a housing, an electrode assembly, an electrode terminal, a first current collecting member, and an insulator. The shell comprises a first end wall and a side wall, and the first end wall is connected to one end of the side wall in the axial direction of the cylindrical single battery. The electrode assembly is housed within the housing. The electrode assembly comprises a main body part, a first tab and a second tab, the polarities of the first tab and the second tab are opposite, the first tab is arranged at one end, deviating from the first end wall, of the main body part and is electrically connected with the shell, and the second tab is arranged at one end, facing the first end wall, of the main body part. The electrode terminal is connected to the first end wall in an insulating manner. The first current collecting member electrically connects the second tab and the electrode terminal. The insulator is at least partially disposed between the first current collecting member and the sidewall. The first current collecting component comprises a current collecting body and a buffer part, the current collecting body is connected with the second tab and the electrode terminal, and the buffer part is connected to the outer edge of the current collecting body. The reliability of the cylindrical battery monomer is high.

Description

Technical Field

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

[0002] Batteries are widely used in the new energy field, such as in electric vehicles and new energy vehicles, which have become a new trend in the automotive industry. The development of battery technology must consider multiple design factors simultaneously, such as energy density, discharge capacity, and charge / discharge rate. Furthermore, battery reliability must also be considered. However, current battery reliability is relatively poor. Utility Model Content

[0003] The purpose of this application is to provide a cylindrical battery cell, a battery device, and an electrical device, which aims to improve the problem of poor battery reliability in related technologies.

[0004] In a first aspect, embodiments of this application provide a cylindrical battery cell, the cylindrical battery cell including a shell, an electrode assembly, electrode terminals, a first current collector, and an insulating member. The shell includes a first end wall and a side wall, and along the axial direction of the cylindrical battery cell, the first end wall is connected to one end of the side wall. The electrode assembly is housed within the shell, and the electrode assembly includes a main body, a first tab, and a second tab, the first tab and the second tab having opposite polarities. The first tab is disposed at the end of the main body opposite to the first end wall and electrically connected to the shell, and the second tab is disposed at the end of the main body facing the first end wall. The electrode terminals are insulatedly connected to the first end wall. The first current collector is disposed between the second tab and the first end wall and electrically connects the second tab and the electrode terminals. The insulating member is at least partially disposed between the first current collector and the side wall. The first current collector includes a current collector body and a buffer portion, the current collector body connecting the second tab and the electrode terminals, and the buffer portion connected to the outer edge of the current collector body.

[0005] In the above technical solution, the first current collector includes a buffer section connected to the outer edge of the current collector body. The presence of the buffer section gives the first current collector a certain degree of flexibility. When the sidewall of the cylindrical battery cell is deformed by external impact, the external impact force is transmitted to the buffer section through the sidewall and the insulating component. The buffer section can deform, which on the one hand reduces the risk of the first current collector cutting through the insulating component and the risk of short circuit due to contact between the sidewall and the first current collector, thus improving the reliability of the cylindrical battery cell. On the other hand, the buffer section can absorb stress, reducing the stress transmitted to the current collector body, thereby helping to reduce the pulling on the second electrode tab and improving the reliability of the cylindrical battery cell. In addition, since the buffer section can deform, it can also accommodate manufacturing errors to a certain extent.

[0006] As an optional technical solution in this application embodiment, the cross-section of the buffer portion is bent, and the cross-section is perpendicular to the extension direction of the buffer portion.

[0007] In the above technical solution, the bent buffer part has better deformation ability, thereby enhancing the buffering capacity of the buffer part and enhancing the absorption effect of the buffer part on the force.

[0008] As an optional technical solution in this application embodiment, the buffer part includes multiple connecting segments. In a cross-section perpendicular to the extending direction of the buffer part, the multiple connecting segments are sequentially connected along the direction of the flow collecting body pointing towards the side wall to form a bent structure.

[0009] In the above technical solution, the buffer section includes multiple connecting segments, which are sequentially connected along the direction from the current collector body towards the sidewall to form a bent structure. This gives the buffer section better deformation capability, thereby enhancing its buffering capacity and stress absorption effect. When the sidewall of the cylindrical battery cell is deformed by external impact, the risk of the first current collector component tearing the insulation is lower, further reducing the risk of short circuit due to contact between the sidewall and the first current collector component, and improving the reliability of the cylindrical battery cell.

[0010] As an optional technical solution in this application embodiment, the angle between two adjacent connecting segments is 20°~90°.

[0011] In the above technical solution, when the angle between two adjacent connecting sections is 20° to 90°, the buffer section has better deformation capacity, which is beneficial to enhancing the buffer capacity of the buffer section and enhancing the absorption effect of the buffer section on the force.

[0012] As an optional technical solution in this application embodiment, the first current collection component includes an edge portion, the edge portion is disposed around the current collection body, and the buffer portion is located between the edge portion and the current collection body and connects the edge portion and the current collection body.

[0013] In the above technical solution, when the sidewall of the cylindrical battery cell is deformed by external impact, the edge can contact the insulating part, which reduces the risk of the buffer part generating sharp corners and piercing the insulating part during deformation, and reduces the risk of short circuit due to contact between the sidewall and the first current collector, which is beneficial to improving the reliability of the cylindrical battery cell.

[0014] As an optional technical solution in this application embodiment, the first current collecting component is provided with a groove, the groove is provided around the current collecting body, and the first current collecting component forms a buffer part in the area where the groove is provided.

[0015] In the above technical solution, the buffer portion is formed by setting a groove on the first current collector, which simplifies the forming method of the buffer portion and reduces the forming difficulty. By arranging the groove around the current collector body, the buffer portion surrounds the current collector body. Thus, when any point on the sidewall of the cylindrical battery cell is impacted along its circumference, the buffer portion can provide a certain degree of cushioning, reducing the risk of the first current collector component tearing the insulation, reducing the risk of short circuits due to contact between the sidewall and the first current collector component, and improving the reliability of the cylindrical battery cell.

[0016] As an optional technical solution in this application embodiment, the first current collector is provided with a plurality of grooves on at least one side along the axial direction of the cylindrical battery cell, and the plurality of grooves provided on the same side of the first current collector are arranged radially along the cylindrical battery cell.

[0017] In the above technical solution, by providing multiple grooves on at least one side of the first current collector along the axial direction of the cylindrical battery cell, multiple buffer parts can be formed accordingly. The multiple buffer parts are arranged radially along the cylindrical battery cell. When the side wall of the cylindrical battery cell is deformed by external impact, the multiple buffer parts can deform and absorb stress, further reducing the risk of the first current collector tearing the insulation, further reducing the risk of short circuit due to contact between the side wall and the first current collector, and improving the reliability of the cylindrical battery cell.

[0018] As an optional technical solution in this application embodiment, the buffer section is arranged around the current collecting body. The buffer section includes a plurality of first buffer segments and a plurality of second buffer segments. The thickness of the first buffer segment is less than the thickness of the second buffer segment, and the thickness of the second buffer segment is less than or equal to the thickness of the current collecting body. The first buffer segment and the second buffer segment are alternately arranged along the circumference of the cylindrical battery cell.

[0019] In the above technical solution, the thickness of the first buffer section is less than the thickness of the second buffer section, which gives the first buffer section a better buffering effect. This helps reduce the risk of the first current collector component scratching the insulation, reduces the risk of short circuits caused by contact between the sidewall and the first current collector component, and improves the reliability of the cylindrical battery cell. The thickness of the second buffer section is greater than the thickness of the first buffer section, but less than or equal to the thickness of the current collector body. This results in higher strength for the second buffer section. The presence of the second buffer section helps reduce the impact on the buffer section when the current collector body is connected to the second tab or the current collector body is connected to the electrode terminal. It also helps maintain the shape of the buffer section, so that the buffer section can play a buffering role when the sidewall of the cylindrical battery cell is deformed by external impact.

[0020] As an optional technical solution in this application embodiment, the first current collector is provided with a plurality of grooves. The plurality of grooves are spaced apart along the circumference of the cylindrical battery cell. The first current collector forms a first buffer segment in the area where the grooves are provided. The second buffer segment is located between two adjacent grooves.

[0021] In the above technical solution, the first buffer section is formed by setting a groove on the first current collector, which simplifies the forming method of the first buffer section and reduces the forming difficulty of the first buffer section.

[0022] As an optional technical solution in this application embodiment, along the axial direction of the cylindrical battery cell, the first current collector has a first surface and a second surface disposed opposite to each other, and both the first surface and the second surface are provided with the groove.

[0023] In the above technical solution, by providing grooves on both the first and second surfaces, the buffer part has better deformation capability, thereby enhancing the buffering capacity and the force absorption effect of the buffer part.

[0024] As an optional technical solution in this application embodiment, the buffer part includes a plurality of first buffer sections, and the first current collector is provided with a plurality of through holes. Along the circumference of the cylindrical battery cell, the plurality of through holes are spaced apart, and a first buffer section is formed between each two adjacent through holes.

[0025] In the above technical solution, by setting multiple through holes on the first current collector, a first buffer section is formed between two adjacent through holes, simplifying the forming method of the buffer section and reducing its forming difficulty. Furthermore, the presence of through holes has two advantages: First, in the event of thermal runaway in a cylindrical battery cell, the emissions inside the cylindrical battery cell can pass through the through holes and flow quickly to the pressure relief mechanism, improving the timeliness of pressure relief, reducing the risk of fire and explosion of the cylindrical battery cell, and thus improving its reliability. Second, during electrolyte injection, the through holes allow electrolyte to pass through, which helps to shorten the injection time and improve injection efficiency.

[0026] As an optional technical solution in this application embodiment, the thickness of the first buffer segment is equal to the thickness of the current collection body.

[0027] In the above technical solution, by making the thickness of the first buffer section equal to the thickness of the current collector body, the strength of the first buffer section is high. The existence of the first buffer section is beneficial to reducing the impact on the buffer part when the current collector body is connected to the second tab and the current collector body is connected to the electrode terminal. It is also beneficial to maintain the shape of the buffer part so that the buffer part can play a buffering role when the side wall of the cylindrical battery cell is deformed by external impact.

[0028] As an optional technical solution in this application embodiment, the minimum distance between two adjacent through holes along the circumference of the cylindrical battery cell is L, which satisfies: 1mm≤L≤5mm.

[0029] In the above technical solution, when L≤5mm, the minimum distance between two adjacent through holes along the circumference of the cylindrical battery cell is small, resulting in a smaller minimum size of the first buffer section along the cylindrical battery cell. When the sidewall of the cylindrical battery cell is deformed by external impact, the first buffer section is more prone to deformation, which helps reduce the risk of the first current collector component tearing the insulation, reduces the risk of short circuit due to contact between the sidewall and the first current collector component, and improves the reliability of the cylindrical battery cell. When L≥1mm, the minimum distance between two adjacent through holes along the circumference of the cylindrical battery cell is not too small, ensuring that the minimum size of the first buffer section along the cylindrical battery cell is not too small and the strength of the first buffer section is not too low. This helps reduce the impact on the buffer section when the current collector body is connected to the second tab or the current collector body is connected to the electrode terminal, and helps maintain the shape of the buffer section so that it can play a buffering role when the sidewall of the cylindrical battery cell is deformed by external impact.

[0030] As an optional technical solution in this application embodiment, the first current collector includes a plurality of buffer sections, which are arranged radially along the cylindrical battery cell.

[0031] In the above technical solution, by setting multiple buffer sections and arranging them radially along the cylindrical battery cell, when the sidewall of the cylindrical battery cell is deformed by external impact, the multiple buffer sections can deform and absorb stress, further reducing the risk of the first current collector component tearing the insulation component, further reducing the risk of short circuit due to contact between the sidewall and the first current collector component, and improving the reliability of the cylindrical battery cell.

[0032] Secondly, embodiments of this application also provide a battery device, which includes the aforementioned cylindrical battery cell.

[0033] Thirdly, embodiments of this application also provide an electrical device, the electrical device including the above-mentioned cylindrical battery cell, the cylindrical battery cell being used to provide electrical energy to the electrical device. Attached Figure Description

[0034] 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.

[0035] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0036] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0037] Figure 3 Exploded views of cylindrical battery cells provided in some embodiments of this application;

[0038] Figure 4 A top view schematic diagram of a cylindrical battery cell provided in some embodiments of this application;

[0039] Figure 5 for Figure 4 A cross-sectional view at position AA in the middle;

[0040] Figure 6 for Figure 5 A magnified view of position B in the middle;

[0041] Figure 7 A top view schematic diagram of a first current collection component provided for some embodiments of this application;

[0042] Figure 8 for Figure 7 A cross-sectional view at position CC;

[0043] Figure 9 A cross-sectional view of a first current collector provided for other embodiments of this application;

[0044] Figure 10 A top view schematic diagram of a first current collection component provided for some embodiments of this application;

[0045] Figure 11 for Figure 10 A cross-sectional view of the DD position in the middle;

[0046] Figure 12 A cross-sectional view of a first current collection component provided for some embodiments of this application;

[0047] Figure 13 This application also provides cross-sectional views of a first current collection component in some embodiments;

[0048] Figure 14 A top view schematic diagram of a first current collection component (with multiple through holes) provided for some embodiments of this application;

[0049] Figure 15 for Figure 14 A cross-sectional view of the EE location.

[0050] Icons: 10-Box body; 11-First box body; 12-Second box body; 20-Cylindrical battery cell; 21-Outer shell; 211-Housing shell; 2111-Side wall; 2112-Bottom wall; 212-End cap; 213-First end wall; 22-Electrode assembly; 221-Main body; 222-First tab; 223-Second tab; 23-Electrode terminal; 241-First current collector; 2411-Current collector body; 24111-First surface; 2411 2-Second surface; 2412-Buffer section; 24121-Connecting section; 24122-First buffer section; 24123-Second buffer section; 2413-Edge section; 2414-Groove; 2415-Through hole; 242-Second current collector; 25-Insulator; 251-First insulating section; 252-Second insulating section; 261-Upper plastic; 262-Lower plastic; 100-Battery device; 200-Controller; 300-Motor; 1000-Vehicle. Detailed Implementation

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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 three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0056] 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.

[0057] In this application, "multiple" means two or more (including two).

[0058] In this embodiment, the cylindrical battery cell can be a secondary battery. A secondary battery refers to a cylindrical battery cell that can be recharged to activate the active materials and continue to be used after it has been discharged.

[0059] Cylindrical battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0060] A cylindrical 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 cylindrical 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, reduces the risk of short circuits while allowing active ions to pass through.

[0061] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0062] 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.

[0063] As an example, the positive electrode current collector can be a foil or a composite current collector. For example, as a 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, 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.).

[0064] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for cylindrical battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may 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 oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0065] 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.

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

[0067] As an example, the negative electrode current collector can be a foil, a foamed metal, or a composite current collector. For example, as a foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, or titanium, etc. The foamed metal can be nickel foam, copper foam, aluminum foam, foam alloy, etc. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector 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.).

[0068] As an example, the negative electrode sheet may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0069] 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.

[0070] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in cylindrical battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for cylindrical battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0071] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0072] In some embodiments, the separator is a separator membrane. The separator membrane can be any known porous structure separator membrane with good chemical and mechanical stability.

[0073] 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 single component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0074] 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.

[0075] In some embodiments, the cylindrical 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 an electrolyte salt and a solvent.

[0076] 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.

[0077] 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.

[0078] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0079] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0080] 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.

[0081] 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 phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0082] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0083] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0084] In some implementations, the electrode assembly is a stacked structure.

[0085] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0086] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0087] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0088] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0089] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0090] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0091] In some implementations, 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.

[0092] In some embodiments, the cylindrical 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.

[0093] The battery device mentioned in the embodiments of this application may include one or more cylindrical battery cell assemblies for providing voltage and capacity. A cylindrical battery cell assembly may include multiple cylindrical battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0094] In some embodiments, a cylindrical battery cell assembly is typically formed by arranging multiple cylindrical battery cells; as an example, a cylindrical battery cell assembly can be a battery module, which is formed by arranging and fixing multiple cylindrical battery cells to form an independent module.

[0095] As an example, a battery module can be formed by bundling multiple cylindrical battery cells together with cable ties.

[0096] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more cylindrical battery cell assemblies housed within the housing.

[0097] As an example, a cylindrical battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0098] As an example, cylindrical battery cell assemblies can also be housed in a housing by directly fixing multiple cylindrical battery cells to the housing.

[0099] 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 cylindrical battery cell assembly. 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.

[0100] 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 cylindrical battery cells.

[0101] 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.

[0102] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0103] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0104] The development of battery technology must consider multiple design factors simultaneously, such as performance parameters like energy density, discharge capacity, and charge / discharge rate. Additionally, battery reliability must also be considered. However, current battery reliability is relatively poor.

[0105] For cylindrical battery cells, to improve their energy density, the first tab of the electrode assembly can be electrically connected to the cell's casing, thus making the casing one output electrode. The second tab of the electrode assembly is connected to an electrode terminal via a first current collector, which is insulated from the casing, serving as the other output electrode. To reduce the risk of a short circuit due to contact between the first current collector and the casing, an insulating element is provided between the first current collector and the sidewall of the casing.

[0106] However, when the sidewall of a cylindrical battery cell is deformed by an external impact, the sidewall and the first current collector are in rigid contact, which makes it easy for the first current collector to tear through the insulation and directly contact the sidewall, resulting in a short circuit and poor reliability of the cylindrical battery cell.

[0107] In view of this, embodiments of this application provide a cylindrical battery cell, which includes a casing, an electrode assembly, electrode terminals, a first current collector, and an insulating member. The casing includes a first end wall and a side wall, and the first end wall is connected to one end of the side wall along the axial direction of the cylindrical battery cell. The electrode assembly is housed within the casing. The electrode assembly includes a main body, a first tab, and a second tab, the first tab and the second tab having opposite polarities. The first tab is disposed at the end of the main body opposite to the first end wall and is electrically connected to the casing, and the second tab is disposed at the end of the main body facing the first end wall. The electrode terminals are insulatedly connected to the first end wall. The first current collector is disposed between the second tab and the first end wall and electrically connects the second tab and the electrode terminals. The insulating member is at least partially disposed between the first current collector and the side wall. The first current collector includes a current collector body and a buffer portion, the current collector body connecting the second tab and the electrode terminals, and the buffer portion connected to the outer edge of the current collector body.

[0108] The first current collector includes a buffer section connected to the outer edge of the current collector body. The presence of the buffer section provides the first current collector with a degree of flexibility. When the sidewall of the cylindrical battery cell deforms due to external impact, the impact force is transmitted to the buffer section through the sidewall and the insulating component. The buffer section can deform, which reduces the risk of the first current collector section tearing the insulating component and the risk of short circuit due to contact between the sidewall and the first current collector section, thus improving the reliability of the cylindrical battery cell. Furthermore, the buffer section can absorb stress, reducing the stress transmitted to the current collector body, thereby reducing the pulling force on the second electrode tab and improving the reliability of the cylindrical battery cell. Additionally, because the buffer section can deform, it can also accommodate manufacturing errors to a certain extent.

[0109] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use cylindrical battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0110] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0111] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0112] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0113] In some embodiments 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 for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0114] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 may include a housing 10 and cylindrical battery cells 20, the housing 10 being used to house the cylindrical battery cells 20.

[0115] The housing 10 has an enclosed space inside for accommodating the cylindrical battery cells 20. The housing 10 can have various structures. In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, which are interlocked. The first housing body 11 and the second housing body 12 can have various shapes, such as cuboids or cylinders. The first housing body 11 can be a hollow structure open on one side, and the second housing body 12 can also be a hollow structure open on one side. The open side of the second housing body 12 interlocks with the open side of the first housing body 11, thus forming a housing 10 with an enclosed space. Alternatively, the first housing body 11 can be a hollow structure open on one side, and the second housing body 12 can be a plate-like structure, with the second housing body 12 interlocked with the open side of the first housing body 11, thus forming a housing 10 with an accommodating chamber.

[0116] In the battery device 100, there can be one or more cylindrical battery cells 20. If there are multiple cylindrical battery cells 20, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that the multiple cylindrical battery cells 20 are connected in both series and parallel. Alternatively, multiple cylindrical battery cells 20 can be first connected in series, in parallel, or in a mixed configuration to form a battery module, and then the multiple battery modules can be connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10. Another option is that all the cylindrical battery cells 20 can be directly connected in series, in parallel, or in a mixed configuration, and then the whole composed of all the cylindrical battery cells 20 is housed within the housing 10.

[0117] In some embodiments, the battery device 100 may further include a busbar component, through which multiple cylindrical battery cells 20 can be electrically connected to each other, enabling series, parallel, or mixed connection of the multiple cylindrical battery cells 20. The busbar component may be a metallic conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0118] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 , Figure 3 An exploded view of a cylindrical battery cell 20 provided in some embodiments of this application. Figure 4 This is a top view of a cylindrical battery cell 20 provided in some embodiments of this application. Figure 5 for Figure 4 A cross-sectional view at position AA. Figure 6 for Figure 5 Enlarged view of position B. This application provides a cylindrical battery cell 20, which includes a housing 21, an electrode assembly 22, electrode terminals 23, a first current collector 241, and an insulator 25. The housing 21 includes a first end wall 213 and a side wall 2111. Along the axial direction of the cylindrical battery cell 20, the first end wall 213 is connected to one end of the side wall 2111. The electrode assembly 22 is housed within the housing 21. The electrode assembly 22 includes a main body 221, a first tab 222, and a second tab 223. The first tab 222 and the second tab 223 have opposite polarities. The first tab 222 is disposed at the end of the main body 221 facing away from the first end wall 213 and is electrically connected to the housing 21. The second tab 223 is disposed at the end of the main body 221 facing the first end wall 213. The electrode terminals 23 are insulatedly connected to the first end wall 213. The first current collector 241 is disposed between the second tab 223 and the first end wall 213, and electrically connects the second tab 223 and the electrode terminal 23. An insulating member 25 is at least partially disposed between the first current collector 241 and the side wall 2111. The first current collector 241 includes a current collector body 2411 and a buffer portion 2412. The current collector body 2411 connects the second tab 223 and the electrode terminal 23, and the buffer portion 2412 is connected to the outer edge of the current collector body 2411.

[0119] Cylindrical battery cell 20 refers to the smallest unit that makes up battery device 100.

[0120] The housing 21 includes a housing 211 and an end cap 212. The housing 211 has a receiving space with an opening at one end for accommodating the electrode assembly 22. The end cap 212 is connected to the housing 211 and closes the opening.

[0121] End cap 212 refers to a component that covers the opening of housing 211 to isolate the internal environment of cylindrical battery cell 20 from the external environment. The shape of end cap 212 can be adapted to the shape of housing 211 to fit it. Optionally, end cap 212 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that end cap 212 is less prone to deformation under pressure and impact, giving cylindrical battery cell 20 higher structural strength and improved reliability. The material of end cap 212 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0122] The housing 211 is a component used to mate with the end cap 212 to form the internal environment of the cylindrical battery cell 20. This internal environment can accommodate the electrode assembly 22, electrolyte, and other components. The housing 211 and the end cap 212 can be independent components. An opening can be provided on the housing 211, and the end cap 212 can be used to close the opening to form the internal environment of the cylindrical battery cell 20. Alternatively, the end cap 212 and the housing 211 can be integrated. Specifically, the end cap 212 and the housing 211 can form a common mating surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 211, the end cap 212 closes the housing 211. The housing 211 of the cylindrical battery cell 20 is cylindrical in shape. The material of the housing 211 can be, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0123] In an embodiment where an opening is formed at one end of the housing 211, one end cap 212 may be provided accordingly. In an embodiment where openings are formed at opposite ends of the housing 211, two end caps 212 may be provided accordingly, with the two end caps 212 respectively closing the two openings of the housing 211, and the two end caps 212 and the housing 211 together defining the receiving space.

[0124] Electrode assembly 22 is the component in the cylindrical battery cell 20 where electrochemical reactions occur. The housing 211 may contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body 221 of the electrode assembly 22, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs are located at opposite ends of the main body 221. During the charging and discharging process of the battery device 100, the positive and negative active materials react with the electrolyte.

[0125] In embodiments where the housing 211 has an opening at only one end, the bottom wall 2112 of the housing 211 opposite to the end cap 212 can serve as the first end wall 213, and the side wall 2111 and the first end wall 213 can be integrally formed to constitute the housing 211; alternatively, the end cap 212 can serve as the first end wall 213, and the side wall 2111 and the bottom wall 2112 can be integrally formed to constitute the housing 211. In embodiments where both opposite ends of the housing 211 have openings, one of the two end caps 212 serves as the first end wall 213, and the side wall 2111 constitutes the housing 211.

[0126] The axial direction of the cylindrical battery cell 20 is also the direction in which the axis of the cylindrical battery cell 20 extends. Please refer to... Figure 3 , Figure 5 and Figure 6 The axial direction of the cylindrical battery cell 20 is the X direction shown in the figure.

[0127] The sidewall 2111 is cylindrical and can be integrally formed with the first endwall 213, thus constituting the housing 211. An opening in the housing 211 is formed at the end of the sidewall 2111 away from the first endwall 213 along the axial direction of the cylindrical battery cell 20, and an end cap 212 closes the opening. Alternatively, the sidewall 2111 and the first endwall 213 can be separate components, with the first endwall 213 serving as the end cap 212, and the sidewall 2111 forming an opening in the housing 211 at the end of the sidewall 2111 near the first endwall 213 along the axial direction of the cylindrical battery cell 20. In embodiments where the sidewall 2111 and the first endwall 213 are separate components, they can be connected by welding, bonding, or roll sealing.

[0128] One of the first tab 222 and the second tab 223 is the aforementioned positive tab, and the other of the first tab 222 and the second tab 223 is the aforementioned negative tab. When the first tab 222 is the positive tab, the second tab 223 is the negative tab. When the first tab 222 is the negative tab, the second tab 223 is the positive tab. The first tab 222 and the second tab 223 are respectively disposed at both ends of the main body portion 221 along the axial direction of the cylindrical battery cell 20. The first tab 222 is disposed at the end of the main body portion 221 along the axial direction of the cylindrical battery cell 20 away from the first end wall 213, and the second tab 223 is disposed at the end of the main body portion 221 along the axial direction of the cylindrical battery cell 20 facing the first end wall 213.

[0129] The first tab 222 is electrically connected to the outer casing 21. The first tab 222 and the outer casing 21 can be directly connected, for example, by soldering the first tab 222 to the outer casing 21. The first tab 222 and the outer casing 21 can also be indirectly connected, for example, through the second current collector 242. The second current collector 242 can be a metallic conductor, such as copper, iron, aluminum, steel, or aluminum alloy.

[0130] Electrode terminal 23 is a component used for electrical connection with the second tab 223 of electrode assembly 22 to input or output electrical energy of cylindrical battery cell 20. Electrode terminal 23 is connected to the second tab 223 via first current collector 241. First current collector 241 can be a metallic conductor, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0131] The electrode terminal 23 is insulated from the first end wall 213, meaning the electrode terminal 23 is insulated from the first end wall 213. Optionally, the cylindrical battery cell 20 includes an upper plastic 261 and a lower plastic 262. The upper plastic 261 is disposed on the side of the first end wall 213 facing away from the electrode assembly 22 and is at least partially located between the electrode terminal 23 and the first end wall 213. The lower plastic 262 is disposed on the side of the first end wall 213 facing the electrode assembly 22 and is at least partially located between the electrode terminal 23 and the first end wall 213. The lower plastic 262 and the upper plastic 261 cooperate to insulate the electrode terminal 23 from the first end wall 213.

[0132] The location of the electrode terminal 23 can be used to determine which wall of the housing 21 is the first end wall 213. For example, when the electrode terminal 23 is located on the end cover 212, then the end cover 212 is the first end wall 213. When the electrode terminal 23 is located on the bottom wall 2112 of the housing 211, which is opposite to the end cover 212, then the bottom wall 2112 of the housing 211, which is opposite to the end cover 212, is the first end wall 213.

[0133] As an example, such as Figure 3 and Figure 4 As shown, the housing 211 has an opening at only one end, and there is one end cap 212. The end cap 212 covers the opening of the housing 211, and the bottom wall 2112 opposite to the end cap 212 is the first end wall 213. The electrode terminal 23 is electrically connected to the second electrode tab 223 through the first current collector 241, and the end cap 212 is electrically connected to the first electrode tab 222 through the second current collector 242.

[0134] At least a portion of the insulating element 25 is disposed between the first current collector 241 and the side wall 2111 to provide insulation between the first current collector 241 and the side wall 2111. Please refer to... Figure 6The insulating member 25 includes a first insulating portion 251 and a second insulating portion 252 connected together. The first insulating portion 251 is disposed around the outside of the second electrode tab 223 to insulate the second electrode tab 223 from the side wall 2111. A portion of the first insulating portion 251 is located between the first current collector 241 and the side wall 2111 to insulate the first current collector 241 from the side wall 2111. The second insulating portion 252 is disposed along the axial direction of the cylindrical battery cell 20 on the side of the second electrode tab 223 facing the first end wall 213, and the second insulating portion 252 is connected to the surface of the first current collector 241 facing the first end wall 213. For example, the insulating member 25 may be made of plastic, rubber, etc.

[0135] The current collector body 2411 is the main part of the first current collector component 241 that performs its function. The current collector body 2411 connects the second tab 223 and the electrode terminal 23 to realize the electrical connection between the second tab 223 and the electrode terminal 23. In some embodiments, the second tab 223 is welded to the current collector body 2411, and the current collector body 2411 is welded to the electrode terminal 23.

[0136] The buffer portion 2412 is a buffering function part of the first current collector 241. The buffer portion 2412 may have better deformability than other areas of the first current collector 241 to achieve this buffering function. This can be achieved by thinning a local area of ​​the first current collector 241 to form the buffer portion 2412; by bending a local area of ​​the first current collector 241 to form the buffer portion 2412; or by changing the grain size of a local area of ​​the first current collector 241, making that area softer, for example, by annealing a local area of ​​the first current collector 241 to form the buffer portion 2412.

[0137] The radial direction of the cylindrical battery cell 20 is the straight line direction of its diameter or radius. The radial direction of the cylindrical battery cell 20 is perpendicular to its axial direction. Please refer to... Figure 5 and Figure 6 The radial direction of the cylindrical battery cell 20 is the Y direction shown in the figure.

[0138] The buffer section 2412 is connected to the outer edge of the current collector body 2411 and is disposed between the current collector body 2411 and the side wall 2111 along the radial direction of the cylindrical battery cell 20. When the side wall 2111 of the cylindrical battery cell 20 is deformed by external impact, the buffer section 2412 can deform to play a buffering role.

[0139] The first current collector 241 includes a buffer portion 2412, which is connected to the outer edge of the current collector body 2411. The presence of the buffer portion 2412 gives the first current collector 241 a certain degree of flexibility. When the sidewall 2111 of the cylindrical battery cell 20 is deformed by an external impact, the external impact force is transmitted to the buffer portion 2412 through the sidewall 2111 and the insulating member 25. The buffer portion 2412 can deform, which reduces the risk of the first current collector 241 tearing the insulating member 25 and the risk of short circuit due to contact between the sidewall 2111 and the first current collector 241, thus improving the reliability of the cylindrical battery cell 20. On the other hand, the buffer portion 2412 can absorb stress and reduce the stress transmitted to the current collector body 2411, thereby helping to reduce the pulling on the second tab 223 and improving the reliability of the cylindrical battery cell 20. In addition, since the buffer portion 2412 can deform, it can also accommodate manufacturing errors to a certain extent.

[0140] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 In some embodiments, the cross-section of the buffer portion 2412 is curved and perpendicular to the extending direction of the buffer portion 2412.

[0141] "The cross-section of the buffer portion 2412 is curved and the cross-section is perpendicular to the extension direction of the buffer portion 2412." That is, within the cross-section perpendicular to the extension direction of the buffer portion 2412, the buffer portion 2412 is a non-linear structure. For example, the buffer portion 2412 can be arc-shaped, broken-line-shaped, etc.

[0142] The curved buffer portion 2412 has better deformation capability, thereby enhancing the buffering capacity of the buffer portion 2412 and improving the force absorption effect of the buffer portion 2412.

[0143] Please refer to Figure 5 , Figure 6 , Figure 7 and Figure 8 , Figure 7 A top view of a first current collector 241 provided for some embodiments of this application. Figure 8 for Figure 7 A cross-sectional view at position CC. In some embodiments, the buffer portion 2412 includes a plurality of connecting segments 24121, which are sequentially connected in a bending structure along the direction from the current collecting body 2411 toward the sidewall 2111 in a cross-section perpendicular to the extending direction of the buffer portion 2412.

[0144] In a cross-section perpendicular to the extending direction of the buffer section 2412, the connecting segment 24121 is a straight segment extending along a straight trajectory. The buffer section 2412 may include two, three, four, or more connecting segments 24121. One end of the connecting segment 24121 closest to the collecting body 2411 is connected to the collecting body 2411, and the other end is connected to one end of another connecting segment 24121. In two adjacent connecting segments 24121, one end of one connecting segment 24121 is connected to one end of another connecting segment 24121, and multiple connecting segments 24121 are sequentially connected along the direction from the collecting body 2411 towards the sidewall 2111 to form a bent structure.

[0145] The buffer section 2412 includes multiple connecting segments 24121, which are sequentially connected along the direction from the current collector body 2411 to the side wall 2111 to form a bent structure. This gives the buffer section 2412 better deformation capability, thereby enhancing its buffering capacity and stress absorption effect. When the side wall 2111 of the cylindrical battery cell 20 is deformed by external impact, the risk of the first current collector 241 tearing the insulation component 25 is lower, further reducing the risk of short circuit due to contact between the side wall 2111 and the first current collector 241, and improving the reliability of the cylindrical battery cell 20.

[0146] Please refer to Figure 5 , Figure 6 , Figure 7 and Figure 8 In some embodiments, the angle between two adjacent connecting segments 24121 is 20° to 90°.

[0147] Please refer to Figure 8 The angle between two adjacent connecting segments 24121 can be represented by α, where 20°≤α≤90°. In two adjacent connecting segments 24121, one segment 24121 has a third surface facing the other segment 24121, and the other segment 24121 has a fourth surface facing the first segment 24121. During measurement, the angle between the third and fourth surfaces can be measured as α.

[0148] The angle between two adjacent connecting segments 24121 can be: 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90°, etc.

[0149] When the angle between two adjacent connecting segments 24121 is 20° to 90°, the buffer part 2412 has better deformation ability, which is conducive to enhancing the buffering capacity of the buffer part 2412 and enhancing the stress absorption effect of the buffer part 2412.

[0150] Please refer to Figure 5 , Figure 6 , Figure 7 and Figure 8 In some embodiments, the first collector component 241 includes an edge portion 2413, which surrounds the collector body 2411, and a buffer portion 2412 is located between the edge portion 2413 and the collector body 2411 and connects the edge portion 2413 and the collector body 2411.

[0151] The edge portion 2413 has a ring-shaped structure and is disposed around the outside of the current collecting body 2411. The outer peripheral surface of the edge portion 2413 is the outer peripheral surface of the first current collecting member 241. The buffer portion 2412 is disposed between the edge portion 2413 and the current collecting body 2411, and the current collecting body 2411 is connected to the edge portion 2413 through the buffer portion 2412.

[0152] When the sidewall 2111 of the cylindrical battery cell 20 is deformed by external impact, the edge portion 2413 can contact the insulating member 25, which reduces the risk that the buffer portion 2412 will generate sharp corners and puncture the insulating member 25 during the deformation process, and reduces the risk of short circuit when the sidewall 2111 and the first current collector 241 come into contact, which is beneficial to improving the reliability of the cylindrical battery cell 20.

[0153] Please refer to Figure 5 , Figure 6 , Figure 7 and Figure 8 In some embodiments, the first current collector 241 is provided with a groove 2414, the groove 2414 is provided around the current collector body 2411, and the first current collector 241 forms a buffer portion 2412 in the area where the groove 2414 is provided.

[0154] The groove 2414 is an annular groove provided on the first collector component 241, and the groove 2414 is disposed around the outside of the collector body 2411. At this time, the buffer part 2412 is an annular structure, and the buffer part 2412 is disposed around the outside of the collector body 2411.

[0155] The groove 2414 may be provided on the side of the first current collector 241 facing the electrode assembly 22, or it may be provided on the side of the first current collector 241 away from the electrode assembly 22, or both the side of the first current collector 241 facing the electrode assembly 22 and the side of the first current collector 241 away from the electrode assembly 22 may be provided with groove 2414. When grooves 2414 are provided on both the side of the first current collector 241 facing the electrode assembly 22 and the side of the first current collector 241 away from the electrode assembly 22, the grooves 2414 on the side of the first current collector 241 facing the electrode assembly 22 and the grooves 2414 on the side of the first current collector 241 away from the electrode assembly 22 may be positioned correspondingly, so that the first current collector 241 forms a buffer portion 2412 in the area where the two grooves 2414 are provided; alternatively, the grooves 2414 on the side of the first current collector 241 facing the electrode assembly 22 and the grooves 2414 on the side of the first current collector 241 away from the electrode assembly 22 may be positioned offset, so that the first current collector 241 forms a buffer portion 2412 in the area where each groove 2414 is provided.

[0156] Please refer to Figure 8 ,exist Figure 8 In the illustrated embodiment, grooves 2414 are provided on both the side of the first current collector 241 facing the electrode assembly 22 and the side of the first current collector 241 away from the electrode assembly 22. The grooves 2414 on the side of the first current collector 241 facing the electrode assembly 22 and the grooves 2414 on the side of the first current collector 241 away from the electrode assembly 22 are positioned correspondingly, so that the two grooves 2414 share a common bottom wall, which is a buffer portion 2412.

[0157] The first current collector 241 may be provided with a groove 2414, such that at least part of the area of ​​the first current collector 241 corresponding to the groove 2414 is bent to form a buffer portion 2412. Alternatively, the first current collector 241 may be provided with a groove 2414 to thin the area of ​​the first current collector 241 corresponding to the groove 2414 to form a buffer portion 2412.

[0158] By forming the buffer portion 2412 by providing a groove 2414 on the first current collector 241, the molding method of the buffer portion 2412 is simplified, and the molding difficulty of the buffer portion 2412 is reduced. By arranging the groove 2414 around the current collector body 2411, that is, by arranging the buffer portion 2412 around the current collector body 2411, the buffer portion 2412 can provide a certain degree of cushioning when any position of the side wall 2111 along the circumference of the cylindrical battery cell 20 is impacted. This reduces the risk of the first current collector 241 tearing the insulation component 25, reduces the risk of short circuit due to contact between the side wall 2111 and the first current collector 241, and improves the reliability of the cylindrical battery cell 20.

[0159] Please refer to Figure 9 , Figure 9 This is a cross-sectional view of a first current collector 241 provided for other embodiments of this application. In some embodiments, the first current collector 241 is provided with a plurality of grooves 2414 on at least one side along the axial direction of the cylindrical battery cell 20, and the plurality of grooves 2414 provided on the same side of the first current collector 241 are arranged radially along the cylindrical battery cell 20.

[0160] The first current collector 241 may have multiple grooves 2414 on one side along the axial direction of the cylindrical battery cell 20. For example, the first current collector 241 may have multiple grooves 2414 on the side facing the electrode assembly 22, or the first current collector 241 may have multiple grooves 2414 on the side away from the electrode assembly 22. Alternatively, the first current collector 241 may have multiple grooves 2414 on both sides along the axial direction of the cylindrical battery cell 20, that is, the first current collector 241 may have multiple grooves 2414 on both the side facing the electrode assembly 22 and the side away from the electrode assembly 22.

[0161] Two, three, four, or more grooves 2414 may be provided on one side of the first current collector 241 along the axial direction of the cylindrical battery cell 20.

[0162] When the first current collector 241 is provided with multiple grooves 2414 on both sides of the cylindrical battery cell 20 along the axial direction, the number of grooves 2414 provided on both sides of the first current collector 241 along the axial direction of the cylindrical battery cell 20 can be the same or different.

[0163] Multiple grooves 2414 disposed on the same side of the first current collector 241 are arranged radially along the cylindrical battery cell 20, thereby forming multiple buffer portions 2412 arranged radially along the cylindrical battery cell 20.

[0164] By providing a plurality of grooves 2414 on at least one side of the first current collector 241 along the axial direction of the cylindrical battery cell 20, a plurality of buffer portions 2412 can be formed accordingly. The plurality of buffer portions 2412 are arranged radially along the cylindrical battery cell 20. When the side wall 2111 of the cylindrical battery cell 20 is deformed by external impact, the plurality of buffer portions 2412 can deform and absorb stress, further reducing the risk of the first current collector 241 tearing the insulation 25, further reducing the risk of short circuit due to contact between the side wall 2111 and the first current collector 241, and improving the reliability of the cylindrical battery cell 20.

[0165] Please refer to Figure 10 and Figure 11 , Figure 10 A top view of a first current collector 241 provided for some embodiments of this application. Figure 11 for Figure 10 A cross-sectional view at the DD position. In some embodiments, the buffer section 2412 is disposed around the current collector body 2411. The buffer section 2412 includes a plurality of first buffer segments 24122 and a plurality of second buffer segments 24123, wherein the thickness of the first buffer segments 24122 is less than the thickness of the second buffer segments 24123, and the thickness of the second buffer segments 24123 is less than or equal to the thickness of the current collector body 2411. The first buffer segments 24122 and the second buffer segments 24123 are alternately arranged along the circumference of the cylindrical battery cell 20.

[0166] The circumferential direction of the cylindrical battery cell 20 is the circumferential direction of the cylindrical battery cell 20. Please refer to... Figure 10 The circumferential direction of the cylindrical battery cell 20 is the Z direction shown in the figure.

[0167] The buffer section 2412 has a ring-shaped structure and is arranged around the outside of the current collecting body 2411. The buffer section 2412 includes a plurality of first buffer segments 24122 and a plurality of second buffer segments 24123, wherein the thickness of the first buffer segment 24122 is less than the thickness of the second buffer segment 24123, the thickness of the second buffer segment 24123 is greater than the thickness of the first buffer segment 24122, and the thickness of the second buffer segment 24123 is less than or equal to the thickness of the current collecting body 2411. The first buffer segment 24122 and the second buffer segment 24123 are alternately arranged along the circumference of the cylindrical battery cell 20. That is, along the circumference of the cylindrical battery cell 20, a second buffer segment 24123 is arranged between two adjacent first buffer segments 24122, the second buffer segment 24123 connects two adjacent first buffer segments 24122, and a first buffer segment 24122 is arranged between two adjacent second buffer segments 24123.

[0168] The thickness of the first buffer section 24122 is less than the thickness of the second buffer section 24123, which gives the first buffer section 24122 a better buffering effect. This helps reduce the risk of the first current collector 241 tearing the insulation 25 and the risk of short circuits caused by contact between the side wall 2111 and the first current collector 241, thus improving the reliability of the cylindrical battery cell 20. The thickness of the second buffer section 24123 is greater than the thickness of the first buffer section 24122, but less than or equal to the thickness of the current collector body 2411. This results in higher strength for the second buffer section 24123. The presence of the second buffer section 24123 helps reduce the impact on the buffer portion 2412 when the current collector body 2411 is connected to the second tab 223 or the electrode terminal 23. It also helps maintain the shape of the buffer portion 2412, so that the buffer portion 2412 can play a buffering role when the side wall 2111 of the cylindrical battery cell 20 is deformed by external impact.

[0169] Please refer to Figure 10 and Figure 11 In some embodiments, the first current collector 241 is provided with a plurality of grooves 2414, which are spaced apart along the circumference of the cylindrical battery cell 20. The first current collector 241 forms a first buffer section 24122 in the area where the grooves 2414 are provided, and a second buffer section 24123 is located between two adjacent grooves 2414.

[0170] The first current collector 241 is provided with a plurality of grooves 2414, which are spaced apart along the circumference of the cylindrical battery cell 20. Each groove 2414 corresponds to a first buffer section 24122. The remaining portion of the first current collector 241 at the location of the grooves 2414 constitutes the first buffer section 24122. A second buffer section 24123 is provided along the circumference of the cylindrical battery cell 20 between two adjacent grooves 2414 and connects two adjacent first buffer sections 24122.

[0171] The first buffer section 24122 is formed by setting a groove 2414 on the first current collector 241, which simplifies the forming method of the first buffer section 24122 and reduces the forming difficulty of the first buffer section 24122.

[0172] Please refer to Figure 12 and Figure 13 , Figure 12 A cross-sectional view of a first current collector 241 provided for some embodiments of this application. Figure 13The present application also provides a cross-sectional view of a first current collector 241 according to some embodiments. In some embodiments, along the axial direction of the cylindrical battery cell 20, the first current collector 241 has a first surface 24111 and a second surface 24112 disposed opposite to each other, and both the first surface 24111 and the second surface 24112 are provided with grooves 2414.

[0173] The grooves 2414 on the first surface 24111 and the grooves 2414 on the second surface 24112 may be positioned correspondingly, so that the first current collector 241 forms a buffer portion 2412 in the area where the two grooves 2414 are provided; or the grooves 2414 on the first surface 24111 and the grooves 2414 on the second surface 24112 may be positioned offset, so that the first current collector 241 forms a buffer portion 2412 in the area where each groove 2414 is provided.

[0174] Please refer to Figure 12 ,exist Figure 12 In the embodiment shown, the groove 2414 provided on the first surface 24111 and the groove 2414 provided on the second surface 24112 are positioned correspondingly, so that the two grooves 2414 share a bottom wall, which is a buffer part 2412.

[0175] Please refer to Figure 13 ,exist Figure 13 In the embodiment shown, the grooves 2414 on the first surface 24111 and the grooves 2414 on the second surface 24112 are staggered, such that the bottom wall of each groove 2414 on the first surface 24111 forms a buffer portion 2412, and the bottom wall of each groove 2414 on the second surface 24112 forms a buffer portion 2412.

[0176] By providing grooves 2414 on both the first surface 24111 and the second surface 24112, the buffer portion 2412 is better able to deform, thereby enhancing its buffering capacity and its stress absorption effect.

[0177] Please refer to Figure 14 and Figure 15 , Figure 14 A top view of a first current collection member 241 (with a plurality of through holes 2415) provided for some embodiments of this application. Figure 15 for Figure 14A cross-sectional view of the EE position. In some embodiments, the buffer section 2412 includes a plurality of first buffer segments 24122, and the first current collector 241 is provided with a plurality of through holes 2415. Along the circumference of the cylindrical battery cell 20, the plurality of through holes 2415 are spaced apart, and a first buffer segment 24122 is formed between each two adjacent through holes 2415.

[0178] The through hole 2415 extends along the axial direction of the cylindrical battery cell 20 through two opposing surfaces of the first current collector 241, that is, the through hole 2415 extends through the first surface 24111 and the second surface 24112. The through hole 2415 can be a circular hole, a triangular hole, a rectangular hole, a fan-shaped hole, etc.

[0179] The first current collector 241 is provided with a plurality of through holes 2415, which are spaced apart along the circumference of the cylindrical battery cell 20. Along the circumference of the cylindrical battery cell 20, a first buffer section 24122 is formed between every two adjacent through holes 2415. The thickness of the first buffer section 24122 can be equal to or less than the thickness of the current collector body 2411. When the thickness of the first buffer section 24122 is less than the thickness of the current collector body 2411, a groove 2414 can be provided on the first current collector 241, and the first buffer section 24122 is formed in the area where the groove 2414 is provided.

[0180] By providing multiple through holes 2415 on the first current collector 241, a first buffer section 24122 is formed between two adjacent through holes 2415, simplifying the forming method of the buffer section 2412 and reducing the forming difficulty of the buffer section 2412. Furthermore, the presence of the through holes 2415 has two advantages. First, in the event of thermal runaway of the cylindrical battery cell 20, the emissions inside the cylindrical battery cell 20 can pass through the through holes 2415 through the first current collector 241 and quickly flow to the pressure relief mechanism, which helps improve the timeliness of pressure relief, reduces the risk of fire and explosion of the cylindrical battery cell 20, and improves the reliability of the cylindrical battery cell 20. Second, during electrolyte injection, the through holes 2415 allow electrolyte to pass through, which helps shorten the injection time and improve the injection efficiency.

[0181] In some embodiments, the thickness of the first buffer segment 24122 is equal to the thickness of the current collection body 2411.

[0182] By making the thickness of the first buffer section 24122 equal to the thickness of the current collector body 2411, the strength of the first buffer section 24122 is higher. The presence of the first buffer section 24122 helps to reduce the impact on the buffer part 2412 when the current collector body 2411 is connected to the second tab 223 and the current collector body 2411 is connected to the electrode terminal 23. It also helps to maintain the shape of the buffer part 2412 so that the buffer part 2412 can play a buffering role when the side wall 2111 of the cylindrical battery cell 20 is deformed by external impact.

[0183] Please refer to Figure 14 and Figure 15 In some embodiments, along the circumference of the cylindrical battery cell 20, the minimum distance between two adjacent through holes 2415 is L, which satisfies: 1mm≤L≤5mm.

[0184] L represents the minimum distance between two adjacent through holes 2415 along the circumference of the cylindrical battery cell 20. L is the arc length. During measurement, multiple measurements can be taken and the average value can be used as L.

[0185] L can be: 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, 3.2mm, 3.5mm, 3.8mm, 4mm, 4.2mm, 4.5mm, 4.8mm, 5mm, etc.

[0186] When L≤5mm, the minimum distance between two adjacent through holes 2415 along the circumference of the cylindrical battery cell 20 is small, which makes the minimum size of the first buffer section 24122 along the cylindrical battery cell 20 smaller. When the side wall 2111 of the cylindrical battery cell 20 is deformed by external impact, the first buffer section 24122 is easy to deform, which helps to reduce the risk of the first current collector 241 tearing the insulation 25, and helps to reduce the risk of short circuit due to contact between the side wall 2111 and the first current collector 241, and helps to improve the reliability of the cylindrical battery cell 20. When L≥1mm, the minimum distance between two adjacent through holes 2415 along the circumference of the cylindrical battery cell 20 is not too small, so that the minimum size of the first buffer section 24122 along the cylindrical battery cell 20 is not too small, and the strength of the first buffer section 24122 is not too low. This helps to reduce the impact on the buffer part 2412 when the current collector 2411 is connected to the second tab 223 and the current collector 2411 is connected to the electrode terminal 23. It also helps to maintain the shape of the buffer part 2412 so that the buffer part 2412 can play a buffering role when the side wall 2111 of the cylindrical battery cell 20 is deformed by external impact.

[0187] In some embodiments, the first current collector 241 includes a plurality of buffer portions 2412, which are arranged radially along the cylindrical battery cell 20.

[0188] The first current collector 241 may include two buffer sections 2412, three buffer sections 2412, four buffer sections 2412, or more buffer sections 2412. The multiple buffer sections 2412 are arranged radially at intervals along the cylindrical battery cell 20.

[0189] By setting multiple buffer sections 2412 and arranging them radially along the cylindrical battery cell 20, when the sidewall 2111 of the cylindrical battery cell 20 is deformed by external impact, the multiple buffer sections 2412 can deform and absorb stress, further reducing the risk of the first current collector 241 tearing the insulation 25, further reducing the risk of short circuit due to contact between the sidewall 2111 and the first current collector 241, and improving the reliability of the cylindrical battery cell 20.

[0190] This application embodiment also provides a battery device 100, which includes the above-described cylindrical battery cell 20.

[0191] This application embodiment also provides an electrical device, which includes the above-mentioned cylindrical battery cell 20, and the cylindrical battery cell 20 is used to provide electrical energy to the electrical device.

[0192] According to some embodiments of this application, please refer to Figures 3-15 .

[0193] This application provides a cylindrical battery cell 20, which includes a housing 21, an electrode assembly 22, electrode terminals 23, a first current collector 241, and an insulator 25. The housing 21 includes a first end wall 213 and a side wall 2111. Along the axial direction of the cylindrical battery cell 20, the first end wall 213 is connected to one end of the side wall 2111. The electrode assembly 22 is housed within the housing 21. The electrode assembly 22 includes a main body 221, a first tab 222, and a second tab 223. The first tab 222 and the second tab 223 have opposite polarities. The first tab 222 is disposed at the end of the main body 221 facing away from the first end wall 213 and is electrically connected to the housing 21. The second tab 223 is disposed at the end of the main body 221 facing the first end wall 213. The electrode terminals 23 are insulatedly connected to the first end wall 213. The first current collector 241 is disposed between the second tab 223 and the first end wall 213, and electrically connects the second tab 223 and the electrode terminal 23. An insulating member 25 is at least partially disposed between the first current collector 241 and the side wall 2111. The first current collector 241 includes a current collector body 2411 and a buffer portion 2412. The current collector body 2411 connects the second tab 223 and the electrode terminal 23, and the buffer portion 2412 is connected to the outer edge of the current collector body 2411. The buffer portion 2412, connected to the outer edge of the current collector body 2411, provides the first current collector 241 with a certain degree of flexibility. When the sidewall 2111 of the cylindrical battery cell 20 is deformed by an external impact, the impact force is transmitted to the buffer portion 2412 through the sidewall 2111 and the insulating member 25. The buffer portion 2412 can deform, which reduces the risk of the first current collector 241 tearing the insulating member 25 and the risk of short circuit due to contact between the sidewall 2111 and the first current collector 241, thus improving the reliability of the cylindrical battery cell 20. On the other hand, the buffer portion 2412 can absorb stress and reduce the stress transmitted to the current collector body 2411, thereby helping to reduce the pulling on the second tab 223 and improving the reliability of the cylindrical battery cell 20. In addition, since the buffer portion 2412 can deform, it can also accommodate manufacturing errors to a certain extent.

[0194] The buffer portion 2412 has a curved cross-section, which is perpendicular to the extending direction of the buffer portion 2412. The curved design of the buffer portion 2412 provides better deformation capability, thereby enhancing its buffering capacity and its stress absorption effect.

[0195] In some embodiments, the first current collector 241 is provided with a groove 2414, which surrounds the current collector body 2411. A buffer portion 2412 is formed in the area where the groove 2414 is provided on the first current collector 241. By forming the buffer portion 2412 by providing a groove 2414 on the first current collector 241, the forming method of the buffer portion 2412 is simplified, and the forming difficulty of the buffer portion 2412 is reduced. By making the groove 2414 surround the current collector body 2411, that is, the buffer portion 2412 surrounds the current collector body 2411, the buffer portion 2412 can play a buffering role to a certain extent when any position of the side wall 2111 along the circumference of the cylindrical battery cell 20 is impacted. This reduces the risk of the first current collector 241 tearing the insulation member 25, reduces the risk of short circuit due to contact between the side wall 2111 and the first current collector 241, and improves the reliability of the cylindrical battery cell 20.

[0196] In other embodiments, a buffer section 2412 is disposed around the current collector body 2411. The buffer section 2412 includes a plurality of first buffer segments 24122 and a plurality of second buffer segments 24123, wherein the thickness of the first buffer segments 24122 is less than the thickness of the second buffer segments 24123, and the thickness of the second buffer segments 24123 is less than or equal to the thickness of the current collector body 2411. The first buffer segments 24122 and the second buffer segments 24123 are alternately arranged along the circumference of the cylindrical battery cell 20. The first current collector member 241 is provided with a plurality of grooves 2414, which are spaced apart along the circumference of the cylindrical battery cell 20. The first current collector member 241 forms a first buffer segment 24122 corresponding to the area where the groove 2414 is provided, and the second buffer segment 24123 is located between two adjacent grooves 2414. The thickness of the first buffer section 24122 is less than the thickness of the second buffer section 24123, which gives the first buffer section 24122 a better buffering effect. This helps reduce the risk of the first current collector 241 tearing the insulation 25 and the risk of short circuits caused by contact between the side wall 2111 and the first current collector 241, thus improving the reliability of the cylindrical battery cell 20. The thickness of the second buffer section 24123 is greater than the thickness of the first buffer section 24122, but less than or equal to the thickness of the current collector body 2411. This results in higher strength for the second buffer section 24123. The presence of the second buffer section 24123 helps reduce the impact on the buffer portion 2412 when the current collector body 2411 is connected to the second tab 223 or the electrode terminal 23. It also helps maintain the shape of the buffer portion 2412, so that the buffer portion 2412 can play a buffering role when the side wall 2111 of the cylindrical battery cell 20 is deformed by external impact. The first buffer section 24122 is formed by setting a groove 2414 on the first current collector 241, which simplifies the forming method of the first buffer section 24122 and reduces the forming difficulty of the first buffer section 24122.

[0197] In some embodiments, the buffer section 2412 includes multiple first buffer segments 24122, and the first current collector 241 is provided with multiple through holes 2415. Along the circumference of the cylindrical battery cell 20, the multiple through holes 2415 are spaced apart, with a first buffer segment 24122 formed between each pair of adjacent through holes 2415. By providing multiple through holes 2415 on the first current collector 241, and correspondingly forming first buffer segments 24122 between adjacent through holes 2415, the forming method of the buffer section 2412 is simplified, and the forming difficulty of the buffer section 2412 is reduced. Furthermore, the presence of the through holes 2415, on the one hand, allows the emissions inside the cylindrical battery cell 20 to pass through the first current collector 241 and quickly flow to the pressure relief mechanism in the event of thermal runaway, which helps improve the timeliness of pressure relief, reduces the risk of fire and explosion of the cylindrical battery cell 20, and improves the reliability of the cylindrical battery cell 20. On the other hand, during injection, the through hole 2415 allows the electrolyte to pass through, which helps to shorten the injection time and improve the injection efficiency.

[0198] The above description is merely a preferred embodiment of this application and is 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 by, include: The outer casing includes a first end wall and a side wall along the axial direction of the cylindrical battery cell, with the first end wall connected to one end of the side wall; An electrode assembly is housed within the housing. The electrode assembly includes a main body, a first electrode tab, and a second electrode tab. The first electrode tab and the second electrode tab have opposite polarities. The first electrode tab is disposed at the end of the main body away from the first end wall and is electrically connected to the housing. The second electrode tab is disposed at the end of the main body facing the first end wall. The electrode terminal is insulated from the first end wall; A first current collector is disposed between the second electrode tab and the first end wall, and is electrically connected to the second electrode tab and the electrode terminal; An insulating element is at least partially disposed between the first current collector and the sidewall; The first current collector includes a current collector body and a buffer section. The current collector body is connected to the second electrode tab and the electrode terminal, and the buffer section is connected to the outer edge of the current collector body.

2. The cylindrical battery cell of claim 1, wherein, The cross-section of the buffer portion is curved, and the cross-section is perpendicular to the extending direction of the buffer portion.

3. The cylindrical battery cell of claim 1, wherein, The buffer section includes multiple connecting segments. In a cross-section perpendicular to the extending direction of the buffer section, the multiple connecting segments are sequentially connected along the direction from the flow collecting body to the sidewall to form a bent structure.

4. The cylindrical battery cell of claim 3, wherein, The angle between two adjacent connecting segments is 20° to 90°.

5. The cylindrical battery cell of claim 1, wherein, The first current collection component includes an edge portion surrounding the current collection body, and a buffer portion is located between the edge portion and the current collection body and connects the edge portion and the current collection body.

6. The cylindrical battery cell according to any one of claims 1 to 5, wherein The first current collecting component is provided with a groove, which surrounds the current collecting body, and the first current collecting component forms a buffer part in the area where the groove is provided.

7. The cylindrical battery cell of claim 6, wherein, The first current collector has a plurality of grooves on at least one side along the axial direction of the cylindrical battery cell, and the plurality of grooves on the same side of the first current collector are arranged radially along the cylindrical battery cell.

8. The cylindrical battery cell of any one of claims 1-5, wherein, The buffer section is arranged around the current collector body. The buffer section includes multiple first buffer segments and multiple second buffer segments. The thickness of the first buffer segment is less than the thickness of the second buffer segment. The thickness of the second buffer segment is less than or equal to the thickness of the current collector body. The first buffer segments and the second buffer segments are alternately arranged along the circumference of the cylindrical battery cell.

9. The cylindrical battery cell of claim 8, wherein, The first current collector is provided with a plurality of grooves, which are spaced apart along the circumference of the cylindrical battery cell. The first current collector forms a first buffer segment in the area where the grooves are provided, and the second buffer segment is located between two adjacent grooves.

10. The cylindrical battery cell of claim 9, wherein, Along the axial direction of the cylindrical battery cell, the first current collector has a first surface and a second surface disposed opposite to each other, and both the first surface and the second surface are provided with the groove.

11. The cylindrical battery cell of any one of claims 1-5, wherein, The buffer section includes multiple first buffer segments. The first current collector is provided with multiple through holes. The multiple through holes are spaced apart along the circumference of the cylindrical battery cell, and a first buffer segment is formed between each two adjacent through holes.

12. The cylindrical battery cell of claim 11, wherein, The thickness of the first buffer segment is equal to the thickness of the current collection body.

13. The cylindrical battery cell of claim 11, wherein, Along the circumference of the cylindrical battery cell, the minimum distance between two adjacent through holes is L, which satisfies: 1mm≤L≤5mm.

14. The cylindrical battery cell of any one of claims 1-5, wherein, The first current collector includes multiple buffer sections, which are arranged radially along the cylindrical battery cell.

15. A battery device, characterized in that, Includes the cylindrical battery cell according to any one of claims 1-14.

16. An electrical device, comprising: Includes a cylindrical battery cell according to any one of claims 1-14, the cylindrical battery cell being used to provide electrical energy to the electrical device.

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