Cylindrical battery monomer, battery device and power utilization device

Abstract

The utility model provides a cylindrical battery monomer, a battery device and a power utilization device. The cylindrical battery monomer comprises an electrode assembly, a shell and a current collecting component, the shell comprises a first end wall, a second end wall and a side wall, the first end wall and the second end wall are arranged at the two ends of the side wall respectively, and the side wall surrounds the electrode assembly. An abutting portion is arranged on one of the first end wall and the side wall. The current collecting member is disposed between the electrode assembly and the first end wall and electrically connects the electrode assembly and the abutment portion. The abutting part is provided with a first abutting face facing the electrode assembly, and the current collecting component abuts against the first abutting face. The first abutting face is provided with a first edge close to the central axis in the radial direction of the cylindrical battery single body and a second edge away from the central axis, and the first end wall is provided with a first plane farthest from the second end wall in the axial direction of the cylindrical battery single body. The first abutting surface is obliquely arranged, and the first edge is closer to the first plane than the second edge in the axial direction of the cylindrical battery monomer. The reliability of the cylindrical battery monomer is relatively high.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular to a cylindrical battery monomer, a battery device and a power utilization device. BACKGROUND

[0002] Batteries are widely used in the field of new energy, for example, electric vehicles, new energy vehicles, etc. New energy vehicles and electric vehicles have become a new trend in the development of the automobile industry. The development of battery technology needs to consider various design factors, such as cycle life, discharge capacity, charge-discharge rate and other performance parameters. In addition, the reliability of the battery also needs to be considered. However, the reliability of the battery is poor at present. CONTENT OF THE UTILITY MODEL

[0003] The purpose of the embodiments of the present application is to provide a cylindrical battery monomer, a battery device and a power utilization device, which aims to improve the problem of poor reliability of the battery in the related art.

[0004] In a first aspect, the embodiments of the present application provide a cylindrical battery monomer, which comprises an electrode assembly, a shell and a current collecting member. The shell comprises a first end wall, a second end wall and a side wall. The first end wall and the second end wall are respectively arranged at two ends of the side wall along the axial direction of the cylindrical battery monomer. The side wall surrounds the electrode assembly. One of the first end wall and the side wall has an abutting portion, which is located outside the central axis of the cylindrical battery monomer. The current collecting member is arranged between the electrode assembly and the first end wall and electrically connects the electrode assembly and the abutting portion. The abutting portion has a first abutting surface facing the electrode assembly, and the current collecting member abuts against the first abutting surface. The first abutting surface has a first edge close to the central axis and a second edge away from the central axis along the radial direction of the cylindrical battery monomer. The first end wall has a first plane farthest away from the second end wall along the axial direction of the cylindrical battery monomer. The first abutting surface is inclinedly arranged, and along the axial direction of the cylindrical battery monomer, the first edge is closer to the first plane than the second edge.

[0005] In the technical scheme, one of the first end wall and the side wall has an abutting portion, the abutting portion can indirectly abut against the electrode assembly through the current collecting member, thereby limiting the electrode assembly and reducing the risk of axial movement of the electrode assembly in the cylindrical battery monomer. The part of the current collecting member not supported by the abutting portion is easily deformed by the gravity of the electrode assembly, so that the current collecting member is raised at the position corresponding to the abutting portion. By tilting the first abutting surface, the deformation of the current collecting member is accommodated, so that the current collecting member can be closely fitted with the first abutting surface, thereby facilitating welding of the current collecting member and the abutting portion, improving the welding quality, improving the overcurrent capacity of the cylindrical battery monomer, reducing the risk of heat accumulation and fire, and thereby improving the reliability of the cylindrical battery monomer.

[0006] As an optional technical scheme of the embodiment of the present application, the included angle between the first abutting surface and the first plane is α, and 2°≤α≤15° is met.

[0007] In the technical scheme, when 2°≤α≤15°, the inclination of the first abutting surface is moderate, which is conducive to closely fitting the current collecting member with the first abutting surface, thereby facilitating welding of the current collecting member and the abutting portion, improving the welding quality, improving the overcurrent capacity of the cylindrical battery monomer, reducing the risk of heat accumulation and fire, and thereby improving the reliability of the cylindrical battery monomer.

[0008] As an optional technical scheme of the embodiment of the present application, 4°≤α≤10° is met.

[0009] In the technical scheme, when 4°≤α≤10°, the inclination of the first abutting surface is more moderate, which is more conducive to closely fitting the current collecting member with the first abutting surface, thereby facilitating welding of the current collecting member and the abutting portion, improving the welding quality, improving the overcurrent capacity of the cylindrical battery monomer, reducing the risk of heat accumulation and fire, and thereby improving the reliability of the cylindrical battery monomer.

[0010] As an optional technical scheme of the embodiment of the present application, the current collecting member has a second abutting surface facing the abutting portion, the second abutting surface abuts against the first abutting surface, the second abutting surface has a third edge close to the central axis and a fourth edge away from the central axis along the radial direction of the cylindrical battery monomer, and the second abutting surface is tilted, and the third edge is closer to the first plane than the fourth edge along the axial direction of the cylindrical battery monomer.

[0011] In the technical scheme, the current collecting component is deformed at least partially in a direction pointing from the second end wall to the first end wall under the gravity of the electrode assembly, so that the second abutting surface is arranged obliquely, and the first abutting surface and the second abutting surface can be closely attached, thereby facilitating welding of the current collecting component and the abutting portion, improving welding quality, improving the overcurrent capacity of the cylindrical battery monomer, reducing the risk of heat accumulation and fire, and thereby improving the reliability of the cylindrical battery monomer.

[0012] As an optional technical scheme of the embodiment, the included angle between the second abutting surface and the first plane is β, and 2° < β ≤ 15° is satisfied.

[0013] In the technical scheme, when 2° < β ≤ 15°, the oblique degree of the second abutting surface is moderate, which is conducive to closely attaching the first abutting surface and the second abutting surface, thereby facilitating welding of the current collecting component and the abutting portion, improving welding quality, improving the overcurrent capacity of the cylindrical battery monomer, reducing the risk of heat accumulation and fire, and thereby improving the reliability of the cylindrical battery monomer.

[0014] As an optional technical scheme of the embodiment, 4° ≤ β ≤ 10°.

[0015] In the technical scheme, when 4° ≤ β ≤ 10°, the oblique degree of the second abutting surface is more moderate, which is more conducive to closely attaching the first abutting surface and the second abutting surface, thereby facilitating welding of the current collecting component and the abutting portion, improving welding quality, improving the overcurrent capacity of the cylindrical battery monomer, reducing the risk of heat accumulation and fire, and thereby improving the reliability of the cylindrical battery monomer.

[0016] As an optional technical scheme of the embodiment, the included angle α between the first abutting surface and the first plane is equal to the included angle β between the second abutting surface and the first plane.

[0017] In the technical scheme, when the included angle α between the first abutting surface and the first plane is equal to the included angle β between the second abutting surface and the first plane, the oblique degrees of the first abutting surface and the second abutting surface are the same, the second abutting surface can better abut against the first abutting surface, the first abutting surface and the second abutting surface are closely attached, thereby facilitating welding of the current collecting component and the abutting portion, improving welding quality, improving the overcurrent capacity of the cylindrical battery monomer, reducing the risk of heat accumulation and fire, and thereby improving the reliability of the cylindrical battery monomer.

[0018] As an optional technical solution of the embodiment of the present application, the electrode assembly comprises a tab; the current collecting member comprises a first current collector and a second current collector connected in series, the second current collector is located between the first current collector and the abutting portion, the base metal of the first current collector is different from that of the second current collector, the base metal of the first current collector is the same as that of the tab, the first current collector is connected with the tab, the base metal of the second current collector is the same as that of the abutting portion, the second current collector is welded with the abutting portion, and the surface of the second current collector away from the first current collector is the second abutting surface.

[0019] In the above technical solution, by making the base metal of the first current collector the same as that of the tab, the first current collector and the tab can be welded with the same base metal, so as to alleviate the phenomenon of different melting points and different thermal expansion coefficients caused by welding the first current collector and the tab with different base metals, thereby reducing the phenomenon of welding cracks between the first current collector and the tab, and facilitating to improve the welding quality of the first current collector and the tab. Similarly, by making the base metal of the second current collector the same as that of the abutting portion, the second current collector and the abutting portion can be welded with the same base metal, so as to alleviate the phenomenon of different melting points and different thermal expansion coefficients caused by welding the second current collector and the abutting portion with different base metals, thereby reducing the phenomenon of welding cracks between the second current collector and the abutting portion, and facilitating to improve the welding quality of the second current collector and the abutting portion.

[0020] As an optional technical solution of the embodiment of the present application, the first end wall is provided with a pressure relief mechanism, the pressure relief mechanism has a predetermined pressure relief area, the predetermined pressure relief area is configured to at least partially open when the cylindrical battery cell is relieved of pressure, and the predetermined pressure relief area is gap arranged with the current collecting member along the axial direction of the cylindrical battery cell.

[0021] In the above technical solution, the first end wall is provided with a pressure relief mechanism, the pressure relief mechanism has a predetermined pressure relief area, the predetermined pressure relief area can open to relieve pressure when the internal pressure or temperature of the cylindrical battery cell reaches a threshold value, thereby reducing the risk of explosion and fire of the cylindrical battery cell. By making the predetermined pressure relief area have a gap with the current collecting member along the axial direction of the cylindrical battery cell, it is beneficial to reduce the risk of interference between the current collecting member and the predetermined pressure relief area, so that the pressure relief mechanism can normally relieve pressure, and it is beneficial to improve the reliability of the cylindrical battery cell.

[0022] As an optional technical solution of the embodiment of the present application, the first end wall comprises a wall body and the abutting portion, the center axis passes through the wall body, the abutting portion is arranged around the outer edge of the wall body, and the abutting portion protrudes from the wall body in a direction close to the electrode assembly along the axial direction of the cylindrical battery cell.

[0023] In the technical solution, the first end wall comprises an abutting portion, the abutting portion of the first end wall can directly or indirectly abut against the electrode assembly, and the electrode assembly is limited, thereby reducing the risk of axial movement of the electrode assembly in the shell along the cylindrical battery monomer.

[0024] As an optional technical solution of the embodiment, the wall body is provided with a predetermined pressure relief area configured to be at least partially opened when the cylindrical battery monomer is relieved of pressure; the abutting portion comprises a first side and a second side, the first side and the second side are oppositely arranged along the width direction of the first abutting surface, the first abutting surface connects the first side and the second side, and the first abutting surface is provided with a first groove penetrating through the first side and the second side.

[0025] In the technical solution, the first groove is provided and penetrates through the first side and the second side, when the cylindrical battery monomer is in thermal runaway, the exhaust generated by the electrode assembly can flow to the predetermined pressure relief area through the first groove, so as to quickly reach the burst pressure of the pressure relief mechanism, shorten the time from the thermal runaway of the cylindrical battery monomer to the start of pressure relief of the cylindrical battery monomer through the pressure relief mechanism, so that the pressure relief mechanism can be actuated in time, and the risk of explosion and fire of the cylindrical battery monomer is reduced, thereby effectively improving the reliability of the cylindrical battery monomer.

[0026] As an optional technical solution of the embodiment, the side wall is provided with a second groove, the second groove is recessed from the outer circumferential surface of the side wall in a direction of the central axis along the outer circumferential surface of the side wall, and forms the abutting portion protruding from the inner circumferential surface of the side wall at a position of the side wall corresponding to the second groove.

[0027] In the technical solution, the side wall comprises an abutting portion, the abutting portion of the side wall can directly or indirectly abut against the electrode assembly, and the electrode assembly is limited, thereby reducing the risk of axial movement of the electrode assembly in the shell along the cylindrical battery monomer. The abutting portion is correspondingly formed by providing the second groove on the side wall, which can effectively reduce the difficulty of forming the abutting portion.

[0028] In a second aspect, the embodiment also provides a battery device, which comprises the cylindrical battery monomer.

[0029] In a third aspect, the embodiment also provides a power consumption device, which comprises the cylindrical battery monomer, and the cylindrical battery monomer is used to provide electric energy for the power consumption device. BRIEF DESCRIPTION OF DRAWINGS

[0030] 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.

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

[0032] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0033] Figure 3 Exploded views of a single battery cell provided in some embodiments of this application;

[0034] Figure 4 Cross-sectional views of a battery cell provided in some embodiments of this application;

[0035] Figure 5 for Figure 4 A magnified view of position A in the middle;

[0036] Figure 6 Cross-sectional views of current collection components provided in some embodiments of this application;

[0037] Figure 7 This application provides a schematic diagram of the structure of the first end wall in some embodiments;

[0038] Figure 8 A cross-sectional view of the first end wall provided for some embodiments of this application;

[0039] Figure 9 Cross-sectional views of a battery cell provided for other embodiments of this application.

[0040] Icon: 10 - case; 11 - first case body; 12 - second case body; 20 - cylindrical battery cell; 21 - outer case; 211 - case body; 2111 - side wall; 21111 - second groove; 21112 - flange portion; 2112 - second end wall; 212 - end cap; 213 - first end wall; 2131 - abutting portion; 21311 - first abutting surface; 21311a - first edge; 21311b - second edge; 21312 - first side surface; 21313 - second side surface; 21314 - first groove; 2132 - wall body; 21321 - first plane; 2133 - predetermined pressure relief area; 21331 - body portion; 21332 - reinforcing portion; 2134 - pressure relief groove; 2135 - flow guide space; 2136 - first flow guide passage; 22 - electrode assembly; 221 - main body portion; 222 - tab; 23 - current collecting member; 231 - first current collector; 232 - second current collector; 2321 - second abutting surface; 23211 - third edge; 23212 - fourth edge; 234 - pressure relief passage; 2341 - first passage; 2342 - second passage; 24 - electrode terminal; 25 - seal; 100 - battery device; 200 - controller; 300 - motor; 1000 - vehicle. DETAILED DESCRIPTION

[0041] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0042] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, not to describe a particular order or primary and secondary relationship.

[0043] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment to other embodiments.

[0044] In the description of the present application, it should be noted that unless specifically defined and limited otherwise, the terms "mount", "connected", "connection", "attach" should be broadly interpreted, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium; can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] The term "and / or" in the present application is only to describe the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents that the front and rear associated objects have an "or" relationship.

[0046] In the embodiments of the present application, the same reference signs represent the same parts, and for the sake of brevity, the detailed description of the same parts is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device, are only exemplary and should not constitute any limitation on the present application.

[0047] "Multiple" appearing in the present application means two or more (including two).

[0048] In the embodiments of the present application, the cylindrical battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging to continue to use.

[0049] The cylindrical battery cell includes but is not limited to lithium ion battery, sodium ion battery, sodium lithium ion battery, lithium metal battery, sodium metal battery, lithium sulfur battery, magnesium ion battery, nickel hydrogen battery, nickel cadmium battery, lead-acid battery, etc.

[0050] The cylindrical battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the cylindrical battery cell, active ions (such as lithium ions) are embedded and extracted between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, which can reduce the risk of short circuit of the positive and negative electrodes, and at the same time allow the active ions to pass through.

[0051] In some embodiments, the positive electrode can be a positive electrode tab, which can include a positive electrode current collector and a positive electrode active material arranged on at least one surface of the positive electrode current collector.

[0052] As an example, the positive electrode current collector has two opposite surfaces in its own thickness direction, and the positive electrode active material is arranged on any one or both of the two opposite surfaces of the positive electrode current collector.

[0053] As an example, the positive electrode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, aluminum subjected to silver plating on the surface, stainless steel subjected to silver plating on the surface, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, or the like can be employed. The composite current collector can include a high molecular material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, or the like) on a high molecular material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0054] As an example, the positive electrode active material can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material can also be used. These positive electrode active materials can be used alone only one or two or more can be used in combination. Among them, examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (such as LiFeP04 (which can also be referred to simply as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnP04), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide can include, but are not limited to, lithium cobalt oxide (such as LiCo02), lithium nickel oxide (such as LiNi02), lithium manganese oxide (such as LiMn02, LiMn204), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which can also be referred to simply as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (which can also be referred to simply as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (which can also be referred to simply as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (which can also be referred to simply as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (which can also be referred to simply as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05O2) and modified compounds thereof, etc.

[0055] In some embodiments, the positive electrode can employ a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. When the foamed metal is employed as the positive electrode, the foamed metal surface can be free of the positive electrode active material, or can be provided with the positive electrode active material. As an example, the foamed metal can be filled or / and deposited with a lithium source material, potassium metal, or sodium metal. The lithium source material can be lithium metal and / or a lithium-rich material.

[0056] In some embodiments, the negative electrode can be a negative electrode tab, which can include a negative electrode current collector.

[0057] As an example, the negative electrode current collector can employ a metal foil, foamed metal, or a composite current collector. For example, as the metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be employed. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed 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 base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0058] As an example, the negative electrode tab can include the negative electrode current collector and the negative electrode active material provided on at least one surface of the negative electrode current collector.

[0059] As an example, the negative electrode current collector has two surfaces opposite in the thickness direction thereof, and the negative electrode active material is provided on either one or both of the two opposite surfaces of the negative electrode current collector.

[0060] As an example, the negative electrode active material can employ a negative electrode active material known in the art for a cylindrical battery cell. As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery negative electrode active material can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0061] In some embodiments, the material of the positive electrode current collector can be aluminum, and the material of the negative electrode current collector can be copper.

[0062] In some embodiments, the separator is a separator film. The separator film can be any porous structure separator film known to have good chemical stability and mechanical stability.

[0063] As an example, the separator film can include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator film can be a single layer film or a multi-layer composite film. When the separator film is a multi-layer composite film, the materials of the layers can be the same or different. The separator can be a separate component between the positive and negative electrodes or can be attached to the surface of the positive and negative electrodes.

[0064] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive and negative electrodes and functions to transport ions and separate the positive and negative electrodes.

[0065] In some embodiments, the cylindrical battery cell further includes an electrolyte that functions to conduct ions between the positive and negative electrodes. The electrolyte can be in a liquid state, a gel state, or a solid state. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0066] In some embodiments, the electrolyte salt can include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonylimide, lithium bis-trifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro oxalate borate, lithium di-oxalate borate, lithium difluoro di-oxalate phosphate, and lithium tetrafluoro oxalate phosphate.

[0067] In some embodiments, the solvent can include at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, butyrosulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be an ether solvent. The ether solvent can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ether.

[0068] Among them, the gel-state electrolyte includes a polymer as a skeleton network of the electrolyte, in combination with an ionic liquid-lithium salt.

[0069] Among them, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, and a composite solid-state electrolyte.

[0070] As an example, the polymer solid-state electrolyte can be a polyether (polyethylene oxide), a polysiloxane, a polycarbonate, a polyacrylonitrile, a polyvinylidene fluoride, a polymethyl methacrylate, a single-ion polymer, a polyionic liquid-lithium salt, a cellulose, or the like.

[0071] As an example, the inorganic solid-state electrolyte can include one or more of an oxide solid-state electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid-state electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorous sulfide, argyrodite), amorphous sulfide), and a halide solid-state electrolyte, a nitride solid-state electrolyte, and a hydride solid-state electrolyte.

[0072] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0073] In some embodiments, the electrode assembly is in a jelly-roll structure. The positive electrode sheet and the negative electrode sheet are wound into the jelly-roll structure.

[0074] In some embodiments, the electrode assembly is in a stack structure.

[0075] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be alternately stacked.

[0076] As an example, a plurality of positive electrode sheets can be provided, and the negative electrode sheet is folded to form a plurality of folded segments that are stacked.

[0077] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded segments that are stacked.

[0078] As an example, a plurality of separators can be provided, and each of the separators is provided between any adjacent positive electrode sheet or negative electrode sheet.

[0079] As an example, the separators can be continuously provided and arranged between any adjacent positive electrode sheet or negative electrode sheet by folding or winding.

[0080] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a multi-prism shape, or the like.

[0081] In some embodiments, the electrode assembly can be provided with tabs. The tabs can guide current out of the electrode assembly. The tabs include positive tabs and negative tabs.

[0082] In some embodiments, the cylindrical battery cell can include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, or the like.

[0083] In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a sealed structure, the housing can serve to protect the electrode assembly and to some extent prevent leakage of electrolyte, etc. When the housing is a non-sealed structure, the housing can serve to protect the electrode assembly, and a sealing bag can be further included between the housing and the electrode assembly for encapsulating the electrode assembly and electrolyte, etc. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum plastic film.

[0084] The battery device mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of cylindrical battery cells connected in series, in parallel, or in a mixed connection through a busbar component.

[0085] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of cylindrical battery cells; as an example, the battery cell assembly can be a battery module formed by arranging and fixing a plurality of cylindrical battery cells into one independent module.

[0086] As an example, the battery module can be formed by bundling a plurality of cylindrical battery cells with a cable tie.

[0087] In some embodiments, the battery device can be a battery pack, which can include a box and one or more battery cell assemblies accommodated in the box.

[0088] As an example, the battery cell assembly can be a battery module, which can be accommodated in the box by fixing the battery module in the box.

[0089] As an example, the battery cell assembly can also be accommodated in the box by directly fixing a plurality of cylindrical battery cells in the box.

[0090] As an example, the box can include a first box body and a second box body. The first box body and the second box body are buckled so that a closed space is formed inside the box to accommodate the battery cell assembly. Here, closed means covered or closed, which can be sealed or non-sealed. The first box body can be a top cover or a bottom plate.

[0091] As an example, the box can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are connected with the frame, so that a closed space is formed inside the box to accommodate the battery cell assembly.

[0092] As an example, the box can be part of the chassis structure of a vehicle. For example, the top cover of the box can be at least part of the floor of the vehicle, or the frame of the box can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0093] In some embodiments, the battery device refers to an energy storage device, and the energy storage device includes a box body, at least one side of the box body is provided with a door. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0094] At present, from the development of market situation, the application of battery is more and more widely. The battery is not only applied to the energy storage power system of hydropower, thermal power, wind power and solar power station, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of battery, the demand of its market is also increasing.

[0095] The development of battery technology needs to consider many design factors, such as cycle life, discharge capacity, charge-discharge rate and other performance parameters. In addition, the reliability of the battery also needs to be considered. However, the reliability of the battery is poor at present.

[0096] In a general cylindrical battery monomer, the abutting portion is provided on the end wall or the side wall, and the abutting portion indirectly abuts against the electrode assembly through the current collecting member to achieve the purpose of reducing the movement of the electrode assembly in the shell. However, only a part of the current collecting member is supported by the abutting portion, and the part of the current collecting member not supported by the abutting portion is easily deformed under the action of gravity of the electrode assembly, so that the corresponding position of the current collecting member and the abutting portion is raised. In a general cylindrical battery monomer, the surface of the abutting portion for abutting against the current collecting member is a plane, and after the corresponding position of the current collecting member and the abutting portion is raised, the gap between the current collecting member and the abutting portion is large. In this way, when the current collecting member and the abutting portion are welded, welding defects such as burst points and pinholes are easily generated. The overcurrent capacity of the welding position of the current collecting member and the abutting portion is poor, heat accumulation is easily generated, and even the cylindrical battery monomer is ignited. Therefore, the reliability of the battery is poor at present.

[0097] In view of this, the embodiment of the present application provides a cylindrical battery monomer, which comprises an electrode assembly, a shell and a current collecting member. The shell comprises a first end wall, a second end wall and a side wall. The first end wall and the second end wall are respectively arranged at two ends of the side wall along the axial direction of the cylindrical battery monomer, and the side wall surrounds the electrode assembly. One of the first end wall and the side wall has an abutting portion, and the abutting portion is located outside the central axis of the cylindrical battery monomer. The current collecting member is arranged between the electrode assembly and the first end wall, and electrically connects the electrode assembly and the abutting portion. The abutting portion has a first abutting surface facing the electrode assembly, and the current collecting member abuts against the first abutting surface. The first abutting surface has a first edge close to the central axis of the cylindrical battery monomer and a second edge away from the central axis along the radial direction of the cylindrical battery monomer, and the first end wall has a first plane farthest away from the second end wall along the axial direction of the cylindrical battery monomer. Wherein, the first abutting surface is inclinedly arranged, and along the axial direction of the cylindrical battery monomer, the first edge is closer to the first plane than the second edge.

[0098] The abutting portion is arranged on one of the first end wall and the side wall, and can indirectly abut against the electrode assembly through the current collecting member, so as to limit the electrode assembly and reduce the risk of axial movement of the electrode assembly in the cylindrical battery monomer. The part of the current collecting member not supported by the abutting portion is easily deformed under the gravity of the electrode assembly, so that the current collecting member is raised at the position corresponding to the abutting portion. By arranging the first abutting surface to be inclined, the deformation of the current collecting member is adapted, so that the current collecting member can be closely fitted with the first abutting surface, thereby facilitating the welding of the current collecting member and the abutting portion, improving the welding quality, improving the overcurrent capacity of the cylindrical battery monomer, reducing the risk of heat accumulation and fire, and thereby improving the reliability of the cylindrical battery monomer.

[0099] The technical solutions described in the embodiments of the present application are applicable to various electric devices using cylindrical battery monomers and battery devices, for example, mobile phones, portable devices, notebook computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, etc., for example, spacecraft including airplanes, rockets, space shuttles and spacecraft, etc.

[0100] The following embodiments are described for convenience of illustration, taking the electric device as a vehicle as an example.

[0101] Please refer to Figure 1 , Figure 1 The structural schematic diagram of the vehicle 1000 provided in some embodiments of the present application is shown. The vehicle 1000 is internally provided with a battery device 100, which can be arranged at the bottom, head or tail of the vehicle 1000. The battery device 100 can be used for power supply of the vehicle 1000, for example, the battery device 100 can be used as the operating power supply of the vehicle 1000.

[0102] The vehicle 1000 can further include a controller 200 and a motor 300, and the controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the working power demand of the vehicle 1000 during starting, navigation and driving.

[0103] In some embodiments of the present application, the battery device 100 can not only be used as the operating power supply of the vehicle 1000, but also be used as the driving power supply of the vehicle 1000, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 1000.

[0104] Please refer to Figure 2 , Figure 2 The exploded view of the battery device 100 provided in some embodiments of the present application is shown. The battery device 100 can include a box 10 and a cylindrical battery monomer 20, and the box 10 is used to accommodate the cylindrical battery monomer 20.

[0105] The box 10 has a closed space inside for accommodating the cylindrical battery cell 20. The box 10 can have various structures. In some embodiments, the box 10 can include a first box body 11 and a second box body 12, which are buckled to each other. The first box body 11 and the second box body 12 can have various shapes, such as a cuboid, a cylinder, etc. The first box body 11 can be a hollow structure with one side open, and the second box body 12 can also be a hollow structure with one side open. The open side of the second box body 12 is buckled to the open side of the first box body 11, thereby forming the box 10 with the closed space. Alternatively, the first box body 11 can be a hollow structure with one side open, and the second box body 12 can be a plate structure. The second box body 12 is buckled to the open side of the first box body 11, thereby forming the box 10 with the accommodation cavity.

[0106] In the battery device 100, the cylindrical battery cell 20 can be one or multiple. If the cylindrical battery cell 20 is multiple, the multiple cylindrical battery cells 20 can be connected in series, in parallel, or in a mixed connection. The mixed connection means that some of the multiple cylindrical battery cells 20 are connected in series, and some are connected in parallel. The multiple cylindrical battery cells 20 can be connected in series, in parallel, or in a mixed connection to form a battery module, and multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, which is accommodated in the box 10. Alternatively, all the cylindrical battery cells 20 can be directly connected in series, in parallel, or in a mixed connection, and the whole formed by the cylindrical battery cells 20 is accommodated in the box 10.

[0107] In some embodiments, the battery device 100 can further include a current collecting component. The multiple cylindrical battery cells 20 can be electrically connected through the current collecting component to achieve the series connection, the parallel connection, or the mixed connection of the multiple cylindrical battery cells 20. The current collecting component can be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0108] Please refer to Figure 3 , Figure 4 and Figure 5 , Figure 3 are the exploded views of the battery cell provided in some embodiments of the present application. Figure 4 are the cross-sectional views of the battery cell provided in some embodiments of the present application. Figure 5 are the cross-sectional views of the battery cell provided in some embodiments of the present application. Figure 4Enlarged view of the middle A position. The embodiments of the present application provide a cylindrical battery monomer 20, which comprises an electrode assembly 22, a shell 21 and a current collecting member 23. The shell 21 comprises a first end wall 213, a second end wall 2112 and a side wall 2111. The first end wall 213 and the second end wall 2112 are respectively arranged at two ends of the side wall 2111 along the axial direction of the cylindrical battery monomer 20, and the side wall 2111 surrounds the electrode assembly 22. One of the first end wall 213 and the side wall 2111 has an abutting portion 2131, which is located outside the central axis of the cylindrical battery monomer 20. The current collecting member 23 is arranged between the electrode assembly 22 and the first end wall 213, and electrically connects the electrode assembly 22 and the abutting portion 2131. The abutting portion 2131 has a first abutting surface 21311 facing the electrode assembly 22, and the current collecting member 23 abuts against the first abutting surface 21311. The first abutting surface 21311 has a first edge 21311a close to the central axis of the cylindrical battery monomer 20 in the radial direction and a second edge 21311b away from the central axis. The first end wall 213 has a first plane 21321 farthest away from the second end wall 2112 in the axial direction of the cylindrical battery monomer 20. Wherein, the first abutting surface 21311 is arranged obliquely, and in the axial direction of the cylindrical battery monomer 20, the first edge 21311a is closer to the first plane 21321 than the second edge 21311b.

[0109] The cylindrical battery monomer 20 refers to the smallest unit constituting the battery device 100.

[0110] The shell 21 comprises a shell body 211 and an end cover 212. The shell body 211 has an open-ended accommodating space for accommodating the electrode assembly 22. The end cover 212 is connected to the shell body 211 and closes the opening.

[0111] The end cover 212 refers to a component that covers the opening of the shell body 211 to isolate the internal environment of the cylindrical battery monomer 20 from the external environment. Without limitation, the shape of the end cover 212 can be adapted to the shape of the shell body 211 to fit the shell body 211. Alternatively, the end cover 212 can be made of a material with certain hardness and strength, such as aluminum alloy, so that the end cover 212 is not easily deformed when subjected to extrusion and collision, enabling the cylindrical battery monomer 20 to have higher structural strength and improved safety performance. The material of the end cover 212 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not specially limited in the embodiments of the present application.

[0112] The shell 211 is a component for cooperating with the end cover 212 to form an internal environment of the cylindrical battery cell 20, and the formed internal environment can be used to accommodate the electrode assembly 22, electrolyte and other components. The shell 211 and the end cover 212 can be independent components, and an opening can be provided on the shell 211, and the end cover 212 is used to cover the opening to form the internal environment of the cylindrical battery cell 20. Without limitation, the end cover 212 and the shell 211 can also be integrated, specifically, the end cover 212 and the shell 211 can form a common joint surface before other components enter the shell, and when it is necessary to seal the internal environment of the shell 211, the end cover 212 is used to cover the shell 211. The shell 211 can be various shapes and sizes, such as a cuboid, a hexagonal prism, etc. Specifically, the shape of the shell 211 can be determined according to the specific shape and size of the electrode assembly 22. The material of the shell 211 can include but is not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0113] In some embodiments, the shell 211 can be formed with an opening at only one end, and the end cover 212 is correspondingly provided at one end. In other embodiments, the shell 211 can be formed with an opening at both ends, and the end cover 212 is correspondingly provided at two ends, and the two end covers 212 respectively seal the two opposite openings of the shell 211. Figure 3 In the illustrated embodiment, the shell 211 is formed with an opening at only one end, and the end cover 212 is correspondingly provided at one end.

[0114] The electrode terminal 24 can also be provided on the end cover 212 or the shell 211, and the electrode terminal 24 is used to electrically connect with the tab 222 of the electrode assembly 22 to input or output the electrical energy of the cylindrical battery cell 20. The electrode terminal 24 can be directly connected with the tab 222, such as directly welded with the tab 222. The electrode terminal 24 can also be indirectly connected with the tab 222, such as indirectly connected with the tab 222 through the current collecting member 23. The current collecting member 23 can be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0115] As an example, in the illustrated embodiment, the shell 211 is formed with an opening at only one end, and the end cover 212 is provided at one end. Figure 3 In the illustrated embodiment, the shell 211 is formed with an opening at only one end, and the end cover 212 is provided at one end, and the end cover 212 seals the opening of the shell 211, and the electrode terminal 24 is provided on the wall of the shell 211 opposite to the end cover 212. The electrode assembly 22 is formed with the tab 222 at both opposite ends, and the tab 222 at one end of the electrode assembly 22 is a positive tab, and the tab 222 at the other end is a negative tab, and the electrode terminal 24 is electrically connected with the positive tab through one current collecting member 23, and the end cover 212 is electrically connected with the negative tab through another current collecting member 23.

[0116] The electrode assembly 22 is a component in which electrochemical reactions occur in the cylindrical battery cell 20. One or more electrode assemblies 22 can be contained within the case 211. The electrode assembly 22 is mainly formed by winding or layering a positive electrode sheet and a negative electrode sheet, and an insulator is generally provided between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet and the negative electrode sheet each have a portion with active material that constitutes a main body portion 221 of the electrode assembly 22, and a portion without active material that constitutes a tab 222. The positive tab and the negative tab can be located together at one end of the main body, or at opposite ends of the main body portion 221. During charging and discharging of the cylindrical battery cell 20, the positive active material and the negative active material react with an electrolyte.

[0117] In the embodiment in which the case 211 has an opening only at one end, the end cap 212 can be the first end wall 213, and the wall portion of the case 211 opposite the end cap 212 can be the second end wall 2112, and the side wall 2111 and the second end wall 2112 can be integrally formed to constitute the case 211; or the wall portion of the case 211 opposite the end cap 212 can be the first end wall 213, and the end cap 212 can be the second end wall 2112, and the side wall 2111 and the first end wall 213 can be integrally formed to constitute the case 211. In the embodiment in which the case 211 has openings at both ends, one of the two end caps 212 can be the first end wall 213, and the other end cap 212 can be the second end wall 2112, and the side wall 2111 can be the case 211.

[0118] The axial direction of the cylindrical battery cell 20 is the direction of extension of the axis of the cylindrical battery cell 20. The radial direction of the cylindrical battery cell 20 is the direction of extension of the diameter or radius of the cylindrical battery cell 20. The axial direction of the cylindrical battery cell 20 is perpendicular to the radial direction of the cylindrical battery cell 20. Please refer to FIG. 1, in which the axial direction of the cylindrical battery cell 20 is the X direction shown in the figure, and the radial direction of the cylindrical battery cell 20 is the Y direction shown in the figure. Figure 3

[0119] The side wall 2111 is in the shape of a cylinder, and the side wall 2111 and the first end wall 213 can be integrally formed to constitute the case 211. The side wall 2111 forms an opening of the case 211 at the end of the first end wall 213 in the axial direction of the cylindrical battery cell 20, and the second end wall 2112 closes the opening, in which case the second end wall 2112 is the end cap 212. Alternatively, the side wall 2111 and the first end wall 213 can be separately provided, and the first end wall 213 is the end cap 212, and the side wall 2111 forms an opening of the case 211 at the end of the first end wall 213 in the axial direction of the cylindrical battery cell 20. In the embodiment in which the side wall 2111 and the first end wall 213 are separately provided, the first end wall 213 and the side wall 2111 can be connected by welding, adhesion, crimping, or the like.

[0120] ​The current collecting member 23 is an electrically conductive member for electrically connecting the electrode assembly 22 to the abutting portion 2131. The current collecting member 23 is located inside the case 21 and between the first end wall 213 and the electrode assembly 22. The first end wall 213 or the side wall 2111 has the abutting portion 2131, and the central axis of the cylindrical battery cell 20 does not pass through the abutting portion 2131. Optionally, the abutting portion 2131 is disposed around the central axis of the cylindrical battery cell 20. The abutting portion 2131 is indirectly abutted to the tab 222 at the end of the electrode assembly 22 via the current collecting member 23. The current collecting member 23 can be welded to the tab 222 at the end of the electrode assembly 22, and the current collecting member 23 can also be welded to the abutting portion 2131 to electrically connect the abutting portion 2131 to the electrode assembly 22.

[0121] The abutting portion 2131 has a first abutting surface 21311, which is the surface of the abutting portion 2131 closest to the second end wall 2112 along the axial direction of the cylindrical battery cell 20. The first abutting surface 21311 is abutted to the current collecting member 23, and the abutting portion 2131 and the current collecting member 23 are welded at the abutting position of the first abutting surface 21311 and the current collecting member 23.

[0122] Along the radial direction of the cylindrical battery cell 20, the first abutting surface 21311 has a first edge 21311a and a second edge 21311b, wherein the first edge 21311a is closer to the central axis of the cylindrical battery cell 20 than the second edge 21311b, and the second edge 21311b is farther away from the central axis of the cylindrical battery cell 20 than the first edge 21311a. In other words, the first edge 21311a is the inner edge of the first abutting surface 21311, and the second edge 21311b is the outer edge of the first abutting surface 21311.

[0123] The first plane 21321 is the surface of the first end wall 213 farthest away from the second end wall 2112 along the axial direction of the cylindrical battery cell 20, i.e., the outer surface of the first end wall 213. In addition, the first plane 21321 is a plane rather than a curved surface.

[0124] The first abutting surface 21311 is inclined, and along the axial direction of the cylindrical battery cell 20, the first edge 21311a is closer to the first plane 21321 than the second edge 21311b, i.e., along the axial direction of the cylindrical battery cell 20, the distance between the first edge 21311a and the first plane 21321 is less than the distance between the second edge 21311b and the first plane 21321.

[0125] The one of the first end wall 213 and the side wall 2111 has an abutting portion 2131 capable of indirectly abutting against the electrode assembly 22 through the current collecting member 23, thereby playing a limiting role on the electrode assembly 22 and reducing the risk of axial movement of the electrode assembly 22 in the cylindrical battery monomer 20 in the shell 21. The part of the current collecting member 23 not supported by the abutting portion 2131 is easily deformed under the action of gravity of the electrode assembly 22, so that the current collecting member 23 is raised at the position corresponding to the abutting portion 2131. By tilting the first abutting surface 21311, the deformation of the current collecting member 23 is accommodated, so that the current collecting member 23 can be closely fitted with the first abutting surface 21311, thereby facilitating the welding of the current collecting member 23 and the abutting portion 2131, improving the welding quality, improving the overcurrent capacity of the cylindrical battery monomer 20, reducing the risk of heat accumulation and fire, thereby improving the reliability of the cylindrical battery monomer 20.

[0126] Please refer to Figure 3 、 Figure 4 and Figure 5 In some embodiments, the first abutting surface 21311 forms an angle α with the first plane 21321, and 2°≤α≤15°.

[0127] α is the angle between the first abutting surface 21311 and the first plane 21321. When measuring, a cross section passing through the axis of the cylindrical battery monomer 20 can be made, and the angle between the intersection line of the first abutting surface 21311 and the cross section and the intersection line of the first plane 21321 and the cross section is measured.

[0128] The angle between the first abutting surface 21311 and the first plane 21321 can be: α=2°, 3°, 4°, 6°, 8°, 10°, 12°, 14°, 15°, etc.

[0129] When 2°≤α≤15°, the inclination of the first abutting surface 21311 is moderate, which is conducive to closely fitting the current collecting member 23 with the first abutting surface 21311, thereby facilitating the welding of the current collecting member 23 and the abutting portion 2131, improving the welding quality, improving the overcurrent capacity of the cylindrical battery monomer 20, reducing the risk of heat accumulation and fire, thereby improving the reliability of the cylindrical battery monomer 20.

[0130] Optionally, 4°≤α≤10°.

[0131] The angle between the first abutting surface 21311 and the first plane 21321 can be: α=4°, 5°, 6°, 7°, 8°, 9°, 10°, etc.

[0132] When 4°≤α≤10°, the inclination of the first abutting surface 21311 is more moderate, which is more conducive to the close contact between the current collecting member 23 and the first abutting surface 21311, thereby facilitating the welding of the current collecting member 23 and the abutting portion 2131, improving the welding quality, improving the overcurrent capacity of the cylindrical battery cell 20, reducing the risk of heat accumulation and fire, thereby improving the reliability of the cylindrical battery cell 20.

[0133] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 , Figure 6 a cross-sectional view of the current collecting member 23 provided by some embodiments of the present application. In some embodiments, the current collecting member 23 has a second abutting surface 2321 facing the abutting portion 2131, and the second abutting surface 2321 abuts against the first abutting surface 21311. The second abutting surface 2321 has a third edge 23211 close to the central axis and a fourth edge 23212 away from the central axis in the radial direction of the cylindrical battery cell 20. The second abutting surface 2321 is inclined, and the third edge 23211 is closer to the first plane 21321 than the fourth edge 23212 in the axial direction of the cylindrical battery cell 20.

[0134] The second abutting surface 2321 is the surface of the current collecting member 23 that abuts against the first abutting surface 21311. In the radial direction of the cylindrical battery cell 20, the second abutting surface 2321 has a third edge 23211 and a fourth edge 23212, wherein the third edge 23211 is closer to the central axis of the cylindrical battery cell 20 than the fourth edge 23212, and the fourth edge 23212 is farther away from the central axis of the cylindrical battery cell 20 than the third edge 23211. In other words, the third edge 23211 is the inner edge of the second abutting surface 2321, and the fourth edge 23212 is the outer edge of the second abutting surface 2321.

[0135] The second abutting surface 2321 is inclined, and the third edge 23211 is closer to the first plane 21321 than the fourth edge 23212 in the axial direction of the cylindrical battery cell 20, that is, the distance between the third edge 23211 and the first plane 21321 is less than the distance between the fourth edge 23212 and the first plane 21321 in the axial direction of the cylindrical battery cell 20.

[0136] The current collecting member 23 is deformed at least partially in the direction of the first end wall 213 from the second end wall 2112 under the gravity of the electrode assembly 22, so that the second abutting surface 2321 is inclined, and the first abutting surface 21311 and the second abutting surface 2321 can be tightly attached, thereby facilitating the welding of the current collecting member 23 and the abutting portion 2131, improving the welding quality, improving the overcurrent capacity of the cylindrical battery monomer 20, reducing the risk of heat accumulation and fire, and thereby improving the reliability of the cylindrical battery monomer 20.

[0137] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 In some embodiments, the angle between the second abutting surface 2321 and the first plane 21321 is β, which satisfies: 2° < β ≤ 15°.

[0138] β is the angle between the second abutting surface 2321 and the first plane 21321. When measuring, a cross section passing through the axis of the cylindrical battery monomer 20 can be made, and the angle between the intersection line of the second abutting surface 2321 and the cross section and the intersection line of the first plane 21321 and the cross section is measured.

[0139] The angle between the second abutting surface 2321 and the first plane 21321 can be: β = 2°, 3°, 4°, 6°, 8°, 10°, 12°, 14°, 15°, etc.

[0140] When 2° < β ≤ 15°, the inclination of the second abutting surface 2321 is moderate, which is conducive to tightly attaching the first abutting surface 21311 and the second abutting surface 2321, thereby facilitating the welding of the current collecting member 23 and the abutting portion 2131, improving the welding quality, improving the overcurrent capacity of the cylindrical battery monomer 20, reducing the risk of heat accumulation and fire, and thereby improving the reliability of the cylindrical battery monomer 20.

[0141] Optionally, 4° ≤ β ≤ 10°.

[0142] The angle between the second abutting surface 2321 and the first plane 21321 can be: β = 4°, 5°, 6°, 7°, 8°, 9°, 10°, etc.

[0143] When 4° ≤ β ≤ 10°, the inclination of the second abutting surface 2321 is more moderate, which is more conducive to tightly attaching the first abutting surface 21311 and the second abutting surface 2321, thereby facilitating the welding of the current collecting member 23 and the abutting portion 2131, improving the welding quality, improving the overcurrent capacity of the cylindrical battery monomer 20, reducing the risk of heat accumulation and fire, and thereby improving the reliability of the cylindrical battery monomer 20.

[0144] Please refer to Figure 3 , Figure 4 , Figure 5 andFigure 6 In some embodiments, the angle a of the first abutting surface 21311 with respect to the first plane 21321 is equal to the angle β of the second abutting surface 2321 with respect to the first plane 21321.

[0145] When the angle a of the first abutting surface 21311 with respect to the first plane 21321 is equal to the angle β of the second abutting surface 2321 with respect to the first plane 21321, the first abutting surface 21311 and the second abutting surface 2321 have the same degree of inclination, and the second abutting surface 2321 can better abut against the first abutting surface 21311, so that the first abutting surface 21311 and the second abutting surface 2321 are closely fitted, thereby facilitating the welding of the current collecting member 23 and the abutting portion 2131, improving the welding quality, improving the overcurrent capacity of the cylindrical battery cell 20, reducing the risk of heat accumulation and fire, and thereby improving the reliability of the cylindrical battery cell 20.

[0146] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 In some embodiments, the electrode assembly 22 includes a tab 222. The current collecting member 23 includes a first current collector 231 and a second current collector 232 connected in series, and the second current collector 232 is located between the first current collector 231 and the abutting portion 2131. The base metal of the first current collector 231 is different from that of the second current collector 232. The base metal of the first current collector 231 is the same as that of the tab 222, and the first current collector 231 is connected to the tab 222. The base metal of the second current collector 232 is the same as that of the abutting portion 2131, and the second current collector 232 is welded to the abutting portion 2131. The surface of the second current collector 232 facing away from the first current collector 231 is the second abutting surface 2321.

[0147] The first current collector 231 is the part of the current collecting member 23 for connecting with the tab 222, and the second current collector 232 is the part of the current collecting member 23 for connecting with the abutting portion 2131, and the first current collector 231 and the second current collector 232 are connected in series.

[0148] The "base metal of the first current collector 231 is different from the base metal of the second current collector 232" means that the main component of the first current collector 231 is different from the main component of the second current collector 232, wherein the main component of the first current collector 231 is a component with a content of 50% or more in the components of the first current collector 231, and the main component of the second current collector 232 is a component with a content of 50% or more in the components of the second current collector 232. That is, the "base metal of the first current collector 231 is different from the base metal of the second current collector 232" means that the main component of the first current collector 231 is different from the main component of the second current collector 232. For example, if the first current collector 231 and the second current collector 232 are both single materials, such as copper or aluminum, the materials of the first current collector 231 and the second current collector 232 are composed of different metal elements. If the first current collector 231 and the second current collector 232 are alloy materials or mixed materials, such as aluminum alloy or steel, the base metal of the first current collector 231 is different from the base metal of the second current collector 232, that is, the main components of the first current collector 231 and the second current collector 232 are different, that is, the components with a content of 50% or more in the alloy materials or mixed materials are different. Alternatively, the material of the first current collector 231 can be copper, and the material of the second current collector 232 can be steel.

[0149] The first current collector 231 and the second current collector 232 are connected, which can be achieved by solid-liquid phase combination method, solid phase combination method, laminated hot rolling method, diffusion pressure bonding method, surfacing method, and surfacing hot rolling method.

[0150] The “first current collector 231 and the base metal of the tab 222 are the same” means that the main component of the first current collector 231 and the main component of the tab 222 are the same, wherein the main component of the first current collector 231 is a component with a content of 50% or more in the components of the first current collector 231, and similarly, the main component of the tab 222 is a component with a content of 50% or more in the components of the tab 222. The material of the tab 222 can also be multiple, such as copper or aluminum, etc. If the tab 222 is a positive tab, the material of the positive tab is usually aluminum, the main component of the first current collector 231 is also an aluminum component, and the content is 50% or more. If the tab 222 is a negative tab, the material of the negative tab is usually copper, the main component of the first current collector 231 is also a copper component, and the content is 50% or more. That is, the “first current collector 231 and the base metal of the tab 222 are the same” means that the main component of the first current collector 231 and the main component of the tab 222 are the same, for example, if the first current collector 231 and the tab 222 are single materials, copper or aluminum, etc., then the material of the first current collector 231 and the tab 222 is composed of the same metal element; if the first current collector 231 and the tab 222 are alloy materials or mixed materials, such as aluminum alloy or steel, etc., then the “first current collector 231 and the base metal of the tab 222 are the same” means that the main components of the first current collector 231 and the tab 222 are the same, that is, the components with a content of 50% or more in the alloy material or mixed material are the same. Alternatively, the material of the first current collector 231 and the tab 222 is copper.

[0151] The first current collector 231 is connected to the tab 222, and optionally, the first current collector 231 is welded to the tab 222. Since the base metal of the first current collector 231 and the tab 222 is the same, it is beneficial to improve the welding quality of the first current collector 231 and the tab 222 and improve the flow capacity.

[0152] "The base metal of the second current collector 232 is the same as that of the contact part 2131" means that the main components of the second current collector 232 and the contact part 2131 are the same. Specifically, the main component of the second current collector 232 is a component comprising 50% or more of its composition, and similarly, the main component of the contact part 2131 is a component comprising 50% or more of its composition. The material of the contact part 2131 can also be various, such as copper or aluminum. If the contact part 2131 is aluminum, the main component of the second current collector 232 will also be aluminum, and its content will be 50% or more. In other words, the fact that the base metal of the second current collector 232 and the contact part 2131 is the same means that the main components of the second current collector 232 and the contact part 2131 are the same. For example, if the second current collector 232 and the contact part 2131 are both made of a single material, such as copper or aluminum, then the materials of the second current collector 232 and the contact part 2131 are composed of the same metallic elements. If the second current collector 232 and the contact part 2131 are made of an alloy or mixed material, such as aluminum alloy or steel, then the fact that the base metal of the second current collector 232 and the contact part 2131 is the same means that the main components of the second current collector 232 and the contact part 2131 are the same, that is, the components with a content of more than 50% in the alloy or mixed material are the same. Optionally, the materials of the second current collector 232 and the contact part 2131 are both steel.

[0153] The second current collector 232 is connected to the abutment part 2131. Optionally, the second current collector 232 and the abutment part 2131 are welded together. Since the base metal of the second current collector 232 and the abutment part 2131 is the same, it is beneficial to improve the welding quality of the second current collector 232 and the abutment part 2131 and improve the current carrying capacity.

[0154] Among them, the surface of the second current collector 232 that is away from the first current collector 231 is the second abutting surface 2321, that is, the surface of the second current collector 232 facing the abutting part 2131 is the second abutting surface 2321.

[0155] By making the base metals of the first current collector 231 and the tab 222 the same, the first current collector 231 and the tab 222 can be mutually welded with the same base metal, so as to alleviate the phenomenon of different melting points and different coefficients of thermal expansion caused by welding the first current collector 231 and the tab 222 with different base metals, thereby reducing the phenomenon of welding cracks between the first current collector 231 and the tab 222, and being beneficial to improving the welding quality of the first current collector 231 and the tab 222. Similarly, by making the base metals of the second current collector 232 and the abutting portion 2131 the same, the second current collector 232 and the abutting portion 2131 can be mutually welded with the same base metal, so as to alleviate the phenomenon of different melting points and different coefficients of thermal expansion caused by welding the second current collector 232 and the abutting portion 2131 with different base metals, thereby reducing the phenomenon of welding cracks between the second current collector 232 and the abutting portion 2131, and being beneficial to improving the welding quality of the second current collector 232 and the abutting portion 2131.

[0156] Please refer to Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 and Figure 8 , Figure 7 a structure schematic view of the first end wall 213 provided by some embodiments of the present application. Figure 8 a sectional view of the first end wall 213 provided by some embodiments of the present application. The first end wall 213 is provided with a pressure relief mechanism, and the pressure relief mechanism has a predetermined pressure relief area 2133 configured to be at least partially opened when the cylindrical battery cell 20 is relieved. Along the axial direction of the cylindrical battery cell 20, the predetermined pressure relief area 2133 is gap provided with the current collecting member 23.

[0157] The pressure relief mechanism is a component for opening when the internal pressure or temperature of the cylindrical battery cell 20 reaches a predetermined value, so as to release the internal pressure of the cylindrical battery cell 20. The pressure relief mechanism can be a component mounted on the first end wall 213, at this time, the pressure relief mechanism is separately provided and connected with the first end wall 213. For example, the pressure relief mechanism is a rupture disc mounted on the first end wall 213. The pressure relief mechanism can also be a part of the first end wall 213, at this time, the pressure relief mechanism is integrally formed with the first end wall 213.

[0158] The pressure relief mechanism includes a weak portion that functions as a pressure relief portion for enabling the pressure relief mechanism to split along the weak portion when the internal pressure or temperature of the cylindrical battery cell 20 reaches a predetermined value, thereby releasing the pressure inside the cylindrical battery cell 20. In some embodiments, the pressure relief mechanism can have a lower strength at the position of the weak portion than at other positions of the pressure relief mechanism, so that the weak portion can split under the action of the internal pressure when the internal pressure or temperature of the cylindrical battery cell 20 reaches the predetermined value, thereby releasing the pressure inside the cylindrical battery cell 20. In other embodiments, the pressure relief mechanism can have a lower melting point at the position of the weak portion than at other positions of the pressure relief mechanism. Thus, the weak portion can split under the action of high temperature when the internal pressure or temperature of the cylindrical battery cell 20 reaches the predetermined value, thereby releasing the pressure inside the cylindrical battery cell 20.

[0159] The weak portion defines a predetermined pressure relief area 2133 that can open to release pressure when the cylindrical battery cell 20 is relieved of pressure, with the weak portion splitting along the edge of the predetermined pressure relief area 2133.

[0160] The weak portion can have a ring shape, such as a circular ring shape or an elliptical ring shape. The weak portion can also have a non-ring shape, such as a C shape or a U shape. The predetermined pressure relief area 2133 is an area in which the pressure relief mechanism forms an opening after the weak portion is broken by the action of gas inside the housing 21. When the weak portion has a ring shape, the predetermined pressure relief area 2133 is an area inside the ring shape. When the weak portion has a non-ring shape, the predetermined pressure relief area 2133 is an area inside a ring shape formed by the weak portion itself and the line connecting the two ends of the weak portion. When the cylindrical battery cell 20 is relieved of pressure, the predetermined pressure relief area 2133 splits along the weak portion, thereby opening a larger opening to release pressure.

[0161] The predetermined pressure relief area 2133 is disposed with a gap in the axial direction of the cylindrical battery cell 20 from the current collecting member 23, i.e., the predetermined pressure relief area 2133 has a gap in the axial direction of the cylindrical battery cell 20 from the current collecting member 23, and the predetermined pressure relief area 2133 does not contact the current collecting member 23.

[0162] The first end wall 213 is provided with a pressure relief mechanism having a predetermined pressure relief area 2133 that can open to release pressure when the internal pressure or temperature of the cylindrical battery cell 20 reaches a threshold value, thereby reducing the risk of explosion or fire of the cylindrical battery cell 20. By having the predetermined pressure relief area 2133 have a gap in the axial direction of the cylindrical battery cell 20 from the current collecting member 23, the risk of interference between the first current collector 231 and the predetermined pressure relief area 2133 is reduced, so that the pressure relief mechanism can normally release pressure, thereby improving the reliability of the cylindrical battery cell 20.

[0163] Please refer to Figure 3 ,Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 and Figure 8 In some embodiments, the first current collector 231 is provided with a pressure relief channel 234 configured to guide the discharge on the side of the first current collector 231 facing the electrode assembly 22 to the pressure relief mechanism.

[0164] In the axial direction of the cylindrical battery cell 20, the pressure relief channel 234 penetrates through the first current collector 231, so that the discharge on the side of the first current collector 231 facing the electrode assembly 22 can pass through the pressure relief channel 234 to the pressure relief mechanism, thereby facilitating pressure relief.

[0165] The discharge includes, but is not limited to, electrolyte, positive and negative electrode sheets dissolved or split, fragments of separators, high-temperature and high-pressure gas generated by reaction, flames, etc.

[0166] By providing the pressure relief channel 234 on the first current collector 231, the discharge on the side of the first current collector 231 facing the electrode assembly 22 can flow to the pressure relief mechanism through the pressure relief channel 234, thereby facilitating rapid pressure relief through the pressure relief mechanism when the internal pressure or temperature of the cylindrical battery cell 20 reaches a threshold value, which is conducive to improving the reliability of the cylindrical battery cell 20.

[0167] Please refer to Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 and Figure 8 In some embodiments, the pressure relief channel 234 includes a first channel 2341 and a plurality of second channels 2342, both the first channel 2341 and the second channels 2342 penetrate through the first current collector 231. The plurality of second channels 2342 are arranged at intervals around the first channel 2341, and the first channel 2341 communicates with the plurality of second channels 2342.

[0168] The pressure relief channel 234 can include two second channels 2342, three second channels 2342, four second channels 2342, or more than four second channels 2342. The plurality of second channels 2342 are arranged at intervals around the first channel 2341.

[0169] By arranging a plurality of second channels 2342 around the first channel 2341 and making the first channel 2341 communicate with the plurality of second channels 2342, the part of the first current collector 231 between two adjacent second channels 2342 can be torn open towards the pressure relief mechanism when the cylindrical battery cell 20 is relieved, thereby forming a larger opening for the discharge to flow to the pressure relief mechanism, which is conducive to achieving rapid pressure relief and improving the reliability of the cylindrical battery cell 20.

[0170] In some embodiments, the number of the second channels 2342 is greater than or equal to 3.

[0171] The number of the second channels 2342 can be 3, 4, 5, or more.

[0172] By making the number of the second channels 2342 greater than or equal to 3, it is beneficial to reduce the area of the portion of the first current collector 231 between two adjacent second channels 2342, so that the portion of the first current collector 231 between two adjacent second channels 2342 is more easily torn open towards the pressure relief mechanism, thereby forming a larger opening for the discharge to flow to the pressure relief mechanism, which is beneficial to achieve rapid pressure relief and improve the reliability of the battery cell.

[0173] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 In some embodiments, the first end wall 213 is provided with a pressure relief groove 2134, the pressure relief groove 2134 is annular, and the pressure relief groove 2134 defines a predetermined pressure relief area 2133.

[0174] The first end wall 213 is provided with a pressure relief groove 2134, and the groove bottom wall of the pressure relief groove 2134 is the above-mentioned weak portion. The pressure relief groove 2134 is annular, for example, the pressure relief groove 2134 can be circular ring, elliptical ring, racetrack shape, etc. The predetermined pressure relief area 2133 is the area inside the annular.

[0175] The pressure relief groove 2134 can be formed in various ways, such as stamping forming, cold heading forming, etc.

[0176] By setting the pressure relief groove 2134 on the first end wall 213, a one-piece pressure relief mechanism is correspondingly formed, the forming method of the pressure relief mechanism is simple, and the reliability of the pressure relief mechanism is higher.

[0177] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 In some embodiments, the predetermined pressure relief area 2133 includes a body portion 21331 and a reinforcing portion 21332, and the reinforcing portion 21332 is arranged on the side of the body portion 21331 facing the first current collector 231. The reinforcing portion 21332 is arranged in a gap with the current collecting member 23.

[0178] The body part 21331 is a main part of the predetermined pressure relief area 2133, the reinforcing part 21332 is a part of the predetermined pressure relief area 2133 protruding from one side of the body part 21331 facing the electrode assembly 22 and reinforcing the body part 21331, and the reinforcing part 21332 can improve the rigidity of the body part 21331 and enhance the deformation resistance of the body part 21331, thereby improving the deformation resistance of the entire body part 21331. The reinforcing part 21332 can be various shapes, such as straight, circular arc, circular ring, U-shaped, circular, rectangular, etc. The reinforcing part 21332 and the body part 21331 can be integrally formed, such as by stamping the reinforcing part 21332 on the body part 21331 to make the reinforcing part 21332 integrally formed with the body part 21331; the reinforcing part 21332 and the body part 21331 can also be separately provided and connected, such as by welding.

[0179] Along the axial direction of the cylindrical battery monomer 20, the reinforcing part 21332 is closer to the current collecting member 23 than the body part 21331, and the reinforcing part 21332 is gap-provided along the axial direction of the cylindrical battery monomer 20 from the current collecting member 23, and the reinforcing part 21332 and the current collecting member 23 are not in contact.

[0180] The predetermined pressure relief area 2133 includes the reinforcing part 21332, which can reinforce the predetermined pressure relief area 2133, provide fatigue resistance for the predetermined pressure relief area 2133, reduce the risk of damage to the predetermined pressure relief area 2133 due to fatigue, and help improve the cycle life of the cylindrical battery monomer 20. By gap-providing the reinforcing part 21332 from the current collecting member 23, it is helpful to reduce the risk of interference between the current collecting member 23 and the reinforcing part 21332, so that the pressure relief mechanism can normally relieve pressure, and it is helpful to improve the reliability of the cylindrical battery monomer 20.

[0181] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 In some embodiments, the first end wall 213 includes a wall body 2132 and an abutting part 2131, the center axis passes through the wall body 2132, and the abutting part 2131 is annularly provided on the outer edge of the wall body 2132. Along the axial direction of the cylindrical battery monomer 20, the abutting part 2131 protrudes from the wall body 2132 in the direction of approaching the electrode assembly 22.

[0182] The wall body 2132 and the abutting portion 2131 can be integrally formed or separately arranged and connected. The pressure relief mechanism can be a pressure relief component separately arranged from the wall body 2132, which is mounted on the wall body 2132. The pressure relief component can be a rupture disc, a pressure relief valve, or the like. The pressure relief mechanism can also be a structure integrally formed with the wall body 2132. The weak portion can be formed by arranging a pressure relief groove 2134 on the wall body 2132, or by performing heat treatment on a local portion of the wall body 2132 to weaken the strength of the local region.

[0183] The abutting portion 2131 can be an annular structure surrounding the outer edge of the wall body 2132, which can be a circular ring structure, a rectangular ring structure, or the like.

[0184] The first end wall 213 includes the abutting portion 2131, which can directly or indirectly abut against the electrode assembly 22 to limit the electrode assembly 22 and reduce the risk of axial movement of the electrode assembly 22 in the cylindrical battery monomer 20.

[0185] Please refer to Figure 7 、 Figure 7 、 Figure 9 、 Figure 9 、 Figure 9 and Figures 3 to 9 In some embodiments, a first flow channel 2136 is formed between the electrode assembly 22 and the side wall 2111. The abutting portion 2131 and the wall body 2132 together define a flow space 2135. The abutting portion 2131 is provided with a first groove 21314, which communicates the flow space 2135 and the first flow channel 2136.

[0186] The flow space 2135 defined by the wall body 2132 and the abutting portion 2131 corresponds to the pressure relief mechanism. After the pressure relief mechanism is actuated, the discharge material in the flow space 2135 can be discharged to the outside of the cylindrical battery monomer 20 through the pressure relief mechanism. In the axial direction of the cylindrical battery monomer 20, the flow space 2135 is formed with an opening portion at one end of the abutting portion 2131 close to the electrode assembly 22. After the abutting portion 2131 indirectly abuts against the electrode assembly 22 through the current collecting member 23, the opening portion is at least partially covered.

[0187] The first groove 21314 on the abutting portion 2131 can be one or multiple. If there are multiple first grooves 21314, they can be uniformly distributed along the circumference of the cylindrical battery monomer 20, or non-uniformly distributed along the circumference of the cylindrical battery monomer 20.

[0188] The first groove 21314 is a notch groove penetrating the abutting portion 2131 in the radial direction of the cylindrical battery cell 20 and extending in the axial direction of the cylindrical battery cell 20 to the abutting portion 2131 near one end of the electrode assembly 22.

[0189] Since the abutting portion 2131 is provided with the first groove 21314, the first groove 21314 communicates the flow guiding space 2135 and the first flow guiding channel 2136, and when the cylindrical battery cell 20 is in thermal runaway, the discharge generated by the electrode assembly 22 flows into the first flow guiding channel 2136, and then the discharge can quickly flow to the flow guiding space 2135 through the first groove 21314 on the abutting portion 2131, so that the air pressure in the flow guiding space 2135 quickly rises to quickly reach the burst pressure of the pressure relief mechanism, shortens the time from the thermal runaway of the cylindrical battery cell 20 to the start of the pressure relief of the cylindrical battery cell 20 through the pressure relief mechanism, so that the pressure relief mechanism can be actuated in time, reduces the risk of explosion and fire of the cylindrical battery cell 20, and effectively improves the reliability of the cylindrical battery cell 20.

[0190] Please refer to ​ , ​ , ​ , ​ , ​ and ​ In some embodiments, the wall body 2132 is provided with a predetermined pressure relief area 2133 configured to at least partially open when the cylindrical battery cell 20 is relieved. The abutting portion 2131 includes a first side surface 21312 and a second side surface 21313 oppositely arranged along the width direction of the first abutting surface 21311, and the first abutting surface 21311 connects the first side surface 21312 and the second side surface 21313. The first abutting surface 21311 is provided with a first groove 21314 penetrating the first side surface 21312 and the second side surface 21313.

[0191] Please refer to ​ In the embodiment shown in ​ , the width direction of the first abutting surface 21311 is parallel to the radial direction of the cylindrical battery cell 20.

[0192] The abutting portion 2131 includes a first side surface 21312 and a second side surface 21313 oppositely arranged along the width direction of the first abutting surface 21311, and the first abutting surface 21311 connects the first side surface 21312 and the second side surface 21313. The first groove 21314 is recessed from the first abutting surface 21311 in a direction away from the electrode assembly 22 and penetrates the first side surface 21312 and the second side surface 21313 in the radial direction of the cylindrical battery cell 20.

[0193] By setting the first groove 21314 and making the first groove 21314 pass through the first side surface 21312 and the second side surface 21313, when the cylindrical battery cell 20 is in thermal runaway, the discharge generated by the electrode assembly 22 can quickly flow to the predetermined pressure relief area 2133 through the first groove 21314 to quickly reach the burst pressure of the pressure relief mechanism, shortening the time from the thermal runaway of the cylindrical battery cell 20 to the start of the pressure relief of the cylindrical battery cell 20 by the pressure relief mechanism, so that the pressure relief mechanism can be actuated in time, reducing the risk of explosion and fire of the cylindrical battery cell 20, and effectively improving the reliability of the cylindrical battery cell 20.

[0194] Please refer to ​ , ​ A cross-sectional view of a battery cell is provided for some embodiments of the present application. In some embodiments, the side wall 2111 is provided with a second groove 21111, and the second groove 21111 is recessed from the outer circumferential surface of the side wall 2111 in a direction towards the central axis along the outer circumferential surface of the side wall 2111, and forms a abutting portion 2131 protruding from the inner circumferential surface of the side wall 2111 at a position of the side wall 2111 corresponding to the second groove 21111.

[0195] The second groove 21111 is provided on the outer circumferential surface of the side wall 2111, specifically, the second groove 21111 is recessed from the outer circumferential surface of the side wall 2111 towards the central axis. The abutting portion 2131 protrudes from the inner circumferential surface of the side wall 2111, and the position of the abutting portion 2131 corresponds to the position of the second groove 21111.

[0196] The second groove 21111 can be formed on the side wall 2111 by stamping. The second groove 21111 is formed on the outer circumferential surface of the side wall 2111 by stamping, and the abutting portion 2131 protruding from the inner circumferential surface of the side wall 2111 is correspondingly formed. Of course, the forming method of the abutting portion 2131 is not limited to this, and in other embodiments, the abutting portion 2131 can also be formed by casting and other processing techniques.

[0197] It should be noted that in the embodiment where the abutting portion 2131 is annular, correspondingly, the second groove 21111 is also an annular groove structure extending along the circumference of the side wall 2111.

[0198] The side wall 2111 includes the abutting portion 2131, and the abutting portion 2131 of the side wall 2111 can directly or indirectly abut against the electrode assembly 22, which limits the electrode assembly 22 and reduces the risk of the electrode assembly 22 moving in the axial direction of the cylindrical battery cell 20 in the housing 21. By setting the second groove 21111 on the side wall 2111 to correspondingly form the abutting portion 2131, the difficulty of forming the abutting portion 2131 can be effectively reduced.

[0199] Please refer to ​In some embodiments, one end of the side wall 2111 is formed with a flange portion 21112 in the axial direction of the cylindrical battery cell 20, and the portion of the first end wall 213 is located between the flange portion 21112 and the abutting portion 2131. The flange portion 21112 and the abutting portion 2131 are configured to cooperate to limit the movement of the first end wall 213 in the axial direction of the cylindrical battery cell 20.

[0200] The flange portion 21112 is a flange structure formed by bending one end of the side wall 2111 away from the second end wall 2112 towards the inside of the shell 21 in the axial direction of the cylindrical battery cell 20, and the flange portion 21112 encloses an opening, i.e., the flange portion 21112 is an annular structure to form an opening on the inner circumferential side of the flange portion 21112.

[0201] In the embodiments of the present application, the outer edge of the first end wall 213 extends between the flange portion 21112 and the abutting portion 2131, so that the flange portion 21112 and the abutting portion 2131 can cooperate to clamp the portion of the first end wall 213 to achieve the assembly connection between the first end wall 213 and the side wall 2111.

[0202] By bending the flange portion 21112 at one end of the side wall 2111 in the axial direction of the cylindrical battery cell 20, and arranging the portion of the first end wall 213 between the abutting portion 2131 and the flange portion 21112 in the axial direction of the cylindrical battery cell 20, the abutting portion 2131 and the flange portion 21112 can also play a role in assembling and fixing the first end wall 213 to achieve the assembly between the first end wall 213 and the side wall 2111. The cylindrical battery cell 20 with this structure can reduce the assembly difficulty between the first end wall 213 and the side wall 2111 to improve the production efficiency of the cylindrical battery cell 20.

[0203] Optionally, the cylindrical battery cell 20 further comprises a sealing member 25, which is at least partially arranged between the first end wall 213 and the abutting portion 2131, so that the sealing member 25 can seal the first end wall 213 and the side wall 2111.

[0204] The embodiments of the present application also provide a battery device 100, which comprises the cylindrical battery cell 20 described above.

[0205] The embodiments of the present application also provide a power consumption device, which comprises the cylindrical battery cell 20 described above, and the cylindrical battery cell 20 is used to provide electric energy for the power consumption device.

[0206] According to some embodiments of the present application, please refer to ​ .

[0207] This application provides a cylindrical battery cell 20, which includes an electrode assembly 22, a housing 21, and a current collector 23. The housing 21 includes a first end wall 213, a second end wall 2112, and a side wall 2111. The first end wall 213 and the second end wall 2112 are respectively disposed at both ends of the side wall 2111 along the axial direction of the cylindrical battery cell 20, and the side wall 2111 surrounds the electrode assembly 22. One of the first end wall 213 and the side wall 2111 has an abutment portion 2131, which is located outside the central axis of the cylindrical battery cell 20. The current collector 23 is disposed between the electrode assembly 22 and the first end wall 213, and electrically connects the electrode assembly 22 and the abutment portion 2131. The abutment portion 2131 has a first abutment surface 21311 facing the electrode assembly 22. The current collector 23 abuts against the first abutment surface 21311. The first abutment surface 21311 has a first edge 21311a radially close to the central axis of the cylindrical battery cell 20 and a second edge 21311b far from the central axis. The first end wall 213 has a first plane 21321 furthest from the second end wall 2112 along the axial direction of the cylindrical battery cell 20. The first abutment surface 21311 is inclined, and along the axial direction of the cylindrical battery cell 20, the first edge 21311a is closer to the first plane 21321 than the second edge 21311b. One of the first end wall 213 and the side wall 2111 has an abutment portion 2131. The abutment portion 2131 can indirectly abut against the electrode assembly 22 through the current collector 23, thereby restricting the electrode assembly 22 and reducing the risk of the electrode assembly 22 moving axially within the casing 21 along the cylindrical battery cell 20. The portion of the current collector 23 not supported by the abutment portion 2131 is easily deformed by the gravity of the electrode assembly 22, causing the position of the current collector 23 corresponding to the abutment portion 2131 to tilt upwards. By tilting the first abutment surface 21311 to accommodate the deformation of the current collector 23, the current collector 23 can fit tightly against the first abutment surface 21311, thereby facilitating the welding of the current collector 23 and the abutment portion 2131, improving welding quality, increasing the current carrying capacity of the cylindrical battery cell 20, reducing the risk of heat buildup and fire, and thus improving the reliability of the cylindrical battery cell 20.

[0208] The angle between the first abutment surface 21311 and the first plane 21321 is α, satisfying: 2°≤α≤15°. When 2°≤α≤15°, the inclination of the first abutment surface 21311 is moderate, which is conducive to the tight fit between the current collector 23 and the first abutment surface 21311, thereby facilitating the welding of the current collector 23 and the abutment part 2131, improving the welding quality, enhancing the current carrying capacity of the cylindrical battery cell 20, reducing the risk of heat accumulation and fire, and thus improving the reliability of the cylindrical battery cell 20.

[0209] The current collecting member 23 has a second abutting surface 2321 facing the abutting portion 2131, which abuts against the first abutting surface 21311. The second abutting surface 2321 has a third edge 23211 close to the center axis and a fourth edge 23212 away from the center axis in the radial direction of the cylindrical battery cell 20. The second abutting surface 2321 is obliquely arranged, and the third edge 23211 is closer to the first plane 21321 than the fourth edge 23212 in the axial direction of the cylindrical battery cell 20. The current collecting member 23 is deformed at least partially in the direction of the first end wall 213 from the second end wall 2112 under the gravity of the electrode assembly 22, so that the second abutting surface 2321 is obliquely arranged. In this way, the first abutting surface 21311 and the second abutting surface 2321 can be closely fitted, so as to facilitate the welding of the current collecting member 23 and the abutting portion 2131, improve the welding quality, improve the overcurrent capacity of the cylindrical battery cell 20, reduce the risk of heat accumulation and fire, and thus improve the reliability of the cylindrical battery cell 20.

[0210] In some embodiments, the second abutting surface 2321 forms an angle β with the first plane 21321, and 2° < β ≤ 15° is satisfied. When 2° < β ≤ 15°, the second abutting surface 2321 is moderately inclined, which is conducive to closely fitting the first abutting surface 21311 and the second abutting surface 2321, so as to facilitate the welding of the current collecting member 23 and the abutting portion 2131, improve the welding quality, improve the overcurrent capacity of the cylindrical battery cell 20, reduce the risk of heat accumulation and fire, and thus improve the reliability of the cylindrical battery cell 20.

[0211] The first abutting surface 21311 forms an angle α with the first plane 21321, and the second abutting surface 2321 forms an angle β with the first plane 21321. When the first abutting surface 21311 forms an angle α with the first plane 21321, and the second abutting surface 2321 forms an angle β with the first plane 21321, the first abutting surface 21311 and the second abutting surface 2321 have the same inclination, the second abutting surface 2321 can better abut against the first abutting surface 21311, so that the first abutting surface 21311 and the second abutting surface 2321 are closely fitted, so as to facilitate the welding of the current collecting member 23 and the abutting portion 2131, improve the welding quality, improve the overcurrent capacity of the cylindrical battery cell 20, reduce the risk of heat accumulation and fire, and thus improve the reliability of the cylindrical battery cell 20.

[0212] The electrode assembly 22 comprises a tab 222. The current collector 23 comprises a first current collector 231 and a second current collector 232 connected to each other, and the second current collector 232 is located between the first current collector 231 and the abutting portion 2131. The base metal of the first current collector 231 is different from that of the second current collector 232. The base metal of the first current collector 231 is the same as that of the tab 222, and the first current collector 231 is connected to the tab 222. The base metal of the second current collector 232 is the same as that of the abutting portion 2131, and the second current collector 232 is welded to the abutting portion 2131. The surface of the second current collector 232 away from the first current collector 231 is a second abutting surface 2321. By making the base metal of the first current collector 231 the same as that of the tab 222, the first current collector 231 and the tab 222 can be welded to each other with the same base metal, so as to alleviate the phenomenon of different melting points and different coefficients of thermal expansion caused by welding the first current collector 231 and the tab 222 with different base metals, thereby reducing the phenomenon of welding cracks between the first current collector 231 and the tab 222, and facilitating to improve the welding quality of the first current collector 231 and the tab 222. Similarly, by making the base metal of the second current collector 232 the same as that of the abutting portion 2131, the second current collector 232 and the abutting portion 2131 can be welded to each other with the same base metal, so as to alleviate the phenomenon of different melting points and different coefficients of thermal expansion caused by welding the second current collector 232 and the abutting portion 2131 with different base metals, thereby reducing the phenomenon of welding cracks between the second current collector 232 and the abutting portion 2131, and facilitating to improve the welding quality of the second current collector 232 and the abutting portion 2131.

[0213] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A cylindrical battery cell, characterized in that, include: Electrode assembly; The housing includes a first end wall, a second end wall, and a side wall. The first end wall and the second end wall are respectively disposed at both ends of the side wall along the axial direction of the cylindrical battery cell. The side wall surrounds the electrode assembly. One of the first end wall and the side wall has an abutment portion located outside the central axis of the cylindrical battery cell. A current collector is disposed between the electrode assembly and the first end wall and electrically connects the electrode assembly and the abutment portion. The abutment portion has a first abutment surface facing the electrode assembly. The current collector abuts against the first abutment surface. The first abutment surface has a first edge along the radial direction of the cylindrical battery cell that is close to the central axis and a second edge that is far from the central axis. The first end wall has a first plane along the axial direction of the cylindrical battery cell that is furthest from the second end wall. The first abutment surface is inclined and along the axial direction of the cylindrical battery cell, the first edge is closer to the first plane than the second edge.

2. The cylindrical battery cell according to claim 1, characterized in that, The angle between the first abutting surface and the first plane is α, which satisfies: 2°≤α≤15°.

3. The cylindrical battery cell according to claim 2, characterized in that, 4°≤α≤10°。 4. The cylindrical battery cell according to claim 1, characterized in that, The current collector has a second abutting surface facing the abutting portion, the second abutting surface abutting against the first abutting surface, the second abutting surface having a third edge close to the central axis and a fourth edge away from the central axis along the radial direction of the cylindrical battery cell, the second abutting surface being inclined along the axial direction of the cylindrical battery cell, the third edge being closer to the first plane than the fourth edge.

5. The cylindrical battery cell according to claim 4, characterized in that, The angle between the second abutting surface and the first plane is β, which satisfies: 2°≤β≤15°.

6. The cylindrical battery cell according to claim 5, characterized in that, 4°≤β≤10°。 7. The cylindrical battery cell according to claim 4, characterized in that, The angle α between the first abutting surface and the first plane is equal to the angle β between the second abutting surface and the first plane.

8. The cylindrical battery cell according to claim 4, characterized in that, The electrode assembly includes tabs; The current collecting component includes a first current collector and a second current collector connected together. The second current collector is located between the first current collector and the abutment portion. The base metals of the first current collector and the second current collector are different. The base metals of the first current collector and the tab are the same. The first current collector is connected to the tab. The base metals of the second current collector and the abutment portion are the same. The second current collector is welded to the abutment portion. The surface of the second current collector facing away from the first current collector is the second abutment surface.

9. The cylindrical battery cell according to claim 1, characterized in that, The first end wall is provided with a pressure relief mechanism, the pressure relief mechanism having a predetermined pressure relief area, the predetermined pressure relief area being configured to at least partially open when the cylindrical battery cell is depressurized, and the predetermined pressure relief area being spaced apart from the current collector along the axial direction of the cylindrical battery cell.

10. The cylindrical battery cell according to any one of claims 1-9, characterized in that, The first end wall includes a wall body and the abutment portion. The central axis passes through the wall body, and the abutment portion is disposed around the outer edge of the wall body along the axial direction of the cylindrical battery cell. The abutment portion protrudes from the wall body in a direction close to the electrode assembly.

11. The cylindrical battery cell according to claim 10, characterized in that, The wall body is provided with a predetermined pressure relief area, which is configured to open at least partially when the cylindrical battery cell is depressurized. The abutting part includes a first side and a second side. Along the width direction of the first abutting surface, the first side and the second side are disposed opposite to each other. The first abutting surface connects the first side and the second side. The first abutting surface is provided with a first groove, which penetrates through the first side and the second side.

12. The cylindrical battery cell according to any one of claims 1-9, characterized in that, The sidewall has the abutting portion, and the sidewall is provided with a second groove. The second groove is recessed from the outer peripheral surface of the sidewall toward the central axis, and the abutting portion protruding from the inner peripheral surface of the sidewall is formed at the position corresponding to the second groove.

13. A battery device, characterized in that, Includes the cylindrical battery cell according to any one of claims 1-12.

14. An electrical appliance, characterized in that, Includes a cylindrical battery cell according to any one of claims 1-12, the cylindrical battery cell being used to provide electrical energy to the electrical device.

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