Cylindrical battery cell, battery device, and electric device

Abstract

The application discloses a cylindrical battery monomer, a battery device and a power utilization device. The cylindrical battery monomer comprises a shell, an electrode assembly and a first current collecting member. The shell has a wall portion. The electrode assembly is arranged in the shell, and the electrode assembly has a first tab. The first current collecting member is located in the shell, and the first tab is electrically connected to the wall portion through the first current collecting member. The first current collecting member comprises a first portion and a second portion connected to each other, the first portion is electrically connected to the first tab, the second portion is welded to the wall portion and forms a welding mark portion, and a protective layer is arranged on the outer side of the wall portion corresponding to the position of the welding mark portion. The technical scheme provided by the application can effectively improve the reliability of the battery device.

Description

Technical Field

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

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

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

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

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

[0006] In a first aspect, some embodiments of this application provide a cylindrical battery cell, which includes a casing, an electrode assembly, and a first current collector. The casing has a wall. The electrode assembly is disposed within the casing and has a first tab. The first current collector is located within the casing, and the first tab is electrically connected to the wall via the first current collector. The first current collector includes a first portion and a second portion interconnected. The first portion is electrically connected to the first tab, and the second portion is welded to the wall to form a solder mark. A protective layer is provided on the outer surface of the wall corresponding to the position of the solder mark.

[0007] In the above scheme, the first current collector is disposed inside the housing and is used to electrically connect the first tab and the wall. Specifically, a first portion of the first current collector is electrically connected to the first tab, and a second portion of the first current collector is welded to the wall to form a solder mark. By providing a protective layer on the outer surface of the wall corresponding to the solder mark, the area where the metal structure changes due to high temperatures during the welding process between the first current collector and the wall can be protected, reducing the risk of corrosion in the area corresponding to the solder mark. This reduces the risk of leakage of internal materials from the battery cell through this area, or the risk of the connection between the first current collector and the wall failing due to corrosion, leading to separation of the first current collector and the wall. This improves the reliability of the cylindrical battery cell and, consequently, the reliability of the battery assembly.

[0008] According to some embodiments of this application, a coating is provided on the outer surface of the wall portion, and at least a portion of the coating is located between the protective layer and the outer surface of the wall portion.

[0009] In the above solution, by applying a coating to the outer surface of the wall, the surface hardness of the wall is improved, reducing the impact of external materials on the wall that could cause the first current collector to separate from the wall, thus enhancing the reliability of the battery cell. Furthermore, it provides corrosion protection, isolating the casing from the outside environment and reducing the risk of leakage of internal materials due to corrosion, thereby enhancing the reliability of the battery cell and ultimately the battery assembly. Simultaneously, a protective layer on the outside of the coating effectively reduces the risk of corrosion due to stress-induced cracking of the coating, further improving the reliability of the cylindrical battery cell and the battery assembly.

[0010] According to some embodiments of this application, the outer shell is a steel shell and the plating is a nickel plating layer.

[0011] In the above scheme, by using a steel shell, the structural strength of the shell can be improved, enhancing the impact resistance of the battery cells. Furthermore, the shell can be made thinner, allowing for the inclusion of more electrochemical substances, thus increasing the volumetric energy density of the battery cells. Simultaneously, by applying a nickel plating layer to the surface of the steel shell, the risk of corrosion can be effectively reduced, improving the reliability of the battery cells and the battery assembly. Additionally, it facilitates the welding of the first current collector to the wall, improving welding quality and consequently enhancing the reliability of the cylindrical battery cells, and ultimately, the reliability of the battery assembly.

[0012] According to some embodiments of this application, the second part and the wall portion are stacked together;

[0013] One end of the solder mark protrudes from the side of the second part away from the wall portion, while the other end of the solder mark is embedded in the wall portion and does not protrude from the side of the wall portion away from the second part, or

[0014] One end of the solder mark protrudes from the side of the wall portion away from the second part, while the other end of the solder mark is embedded in the second part and does not protrude from the side of the second part away from the wall portion.

[0015] In the above scheme, the second part of the first current collector is stacked with the wall, which facilitates welding of the second part to the wall and results in high welding quality.

[0016] In some embodiments where the second part and the wall are stacked, by setting the solder mark to have one end protruding from the side of the second part away from the wall and the other end not protruding from the side of the wall away from the second part, the impact of the solder mark on the structural reliability of the wall can be reduced. That is, the impact of the heat generated during the welding process between the second part and the wall on the wall can be reduced, thereby reducing the risk of corrosion of the wall, which is beneficial to improving the reliability of the cylindrical battery cell and thus to improving the reliability of the battery device.

[0017] In some other embodiments where the second part is stacked with the wall, by setting the solder portion to have one end protruding from the side of the wall away from the second part and the other end not protruding from the side of the second part away from the wall, on the one hand, the influence of the solder portion on the structural components of the second part away from the wall and located inside the casing can be reduced, thus ensuring the structural reliability of the internal structural components of the cylindrical battery cell to a certain extent, thereby improving the reliability of the cylindrical battery cell and consequently the reliability of the battery device. On the other hand, it can reduce the space occupied by the solder portion inside the cylindrical battery cell, thereby allowing more active material to be placed inside the casing, which is beneficial to improving the volumetric energy density of the cylindrical battery cell and consequently the volumetric energy density of the battery device.

[0018] According to some embodiments of this application, the second part and the wall part are stacked, one end of the solder stamp protrudes from the side of the second part away from the wall part, and the other end of the solder stamp protrudes from the side of the wall part away from the second part.

[0019] In the above scheme, the second part of the first current collector is stacked with the wall, and the two ends of the soldered part protrude from the side opposite to the second part and the wall, which can effectively improve the welding quality of the second part and the wall, reduce the risk of the second part and the wall separating due to external or internal impact on the cylindrical battery cell, thereby improving the reliability of the cylindrical battery cell and thus improving the reliability of the battery device.

[0020] According to some embodiments of this application, the housing includes a shell and an end cap. The shell includes an integrally formed sidewall and a bottom wall. The sidewall surrounds the bottom wall, and along a first direction, one end of the sidewall is connected to the bottom wall, while the other end forms an opening. The sidewall and the bottom wall together define a receiving cavity, in which the electrode assembly is received. The first direction is the axial direction of the shell. The end cap closes the opening. The wall portion is either a sidewall or a bottom wall.

[0021] In the above solution, by setting the side wall or bottom wall of the housing as a wall, the second part of the first current collector is a structure welded to the side wall or bottom wall of the housing. This can alleviate the stress generated by the first current collector pulling or torsion on the wall and thus reduce the risk of connection failure between the end cover and the housing, thereby effectively improving the reliability of the cylindrical battery cell.

[0022] According to some embodiments of this application, the wall portion is a sidewall. A first protrusion is provided on the side of the sidewall facing the receiving cavity, and a second protrusion is provided at the end of the sidewall away from the bottom wall in a first direction. Along the first direction, at least a portion of the electrode assembly is located on the side of the first protrusion opposite to the second protrusion, and an end cap is located between the first protrusion and the second protrusion.

[0023] In the above scheme, a first protrusion and a second protrusion are provided on the side wall, and at least a portion of the electrode assembly is located on the side of the first protrusion away from the second protrusion. The end cap is located between the first protrusion and the second protrusion. The cylindrical battery cell with this structure can limit or position the electrode assembly and the end cap to a certain extent through the first protrusion and the second protrusion, which helps to reduce the assembly difficulty of the cylindrical battery cell, so that the cylindrical battery cell has high manufacturing efficiency, and thus the battery device has high manufacturing efficiency.

[0024] According to some embodiments of this application, the second part is welded to the first protrusion to form a solder mark.

[0025] In the above scheme, the first protrusion is welded to the second part to form a weld mark. The cylindrical battery cell with this structure can make reasonable use of the first protrusion, which plays a limiting and positioning role, to weld to the first current collector. This can reduce the welding difficulty between the second part of the first current collector and the wall, thereby reducing the difficulty of assembling the first current collector in the casing, and thus improving the manufacturing efficiency of the battery device.

[0026] According to some embodiments of this application, along a first direction, the second portion is welded to the side of the first protrusion facing the end cap to form a solder mark.

[0027] In the above scheme, the electrode assembly is located on the side of the first protrusion away from the end cover, the first current collector is connected to the first tab of the electrode assembly, and the second part of the first current collector is located on the side of the first protrusion facing the end cover and is welded to the side of the first protrusion facing the end cover. The cylindrical battery cell with this structure can, on the one hand, realize that the first current collector and the first protrusion can share part of the space in the first direction, which is beneficial to improve the internal space utilization of the cylindrical battery cell and thus improve the volumetric energy density of the cylindrical battery cell. On the other hand, the second part of the first current collector is located on the side of the first protrusion facing the opening of the shell in the first direction and is welded to the surface of the first protrusion facing the opening. This allows the first protrusion and the second part to be welded together from the opening of the shell, which is beneficial to optimize the production process of the cylindrical battery cell and reduce the assembly difficulty of the cylindrical battery cell.

[0028] According to some embodiments of this application, along a first direction, the second portion is welded to the side of the first protrusion opposite to the end cap to form a solder mark.

[0029] In the above technical solution, by setting the second part of the first current collector to be located on the side of the first part away from the end cover in the first direction and welding it to the side of the first part away from the end cover, the second part of the first current collector and the electrode assembly are both located on the side of the first protrusion away from the end cover. This helps to reduce the assembly difficulty of the first current collector and the electrode assembly. In addition, the first protrusion can also play a certain role in limiting and positioning the first current collector, reducing the risk of electrical connection failure between the first current collector and the first tab and between the first current collector and the wall. This is beneficial to improving the reliability of the cylindrical battery cell, and thus to improving the reliability of the battery device.

[0030] According to some embodiments of this application, the first current collector further includes a transition portion connecting the first portion and the second portion, and the transition portion is configured to deform when the first portion and the second portion move closer to or further away from each other along a first direction.

[0031] In the above scheme, the first current collector is also provided with a transition portion connecting the first part and the second part. By setting the transition portion as a structure that can deform when the first part and the second part move closer or further apart along the first direction, the transition portion can play a certain buffering role between the first part and the second part. In the process of the electrode assembly shaking or shifting, it can alleviate the rigid tension between the first part and the second part, between the first part and the first tab, and between the second part and the first protrusion. This is beneficial to further reduce the risk of electrical connection failure between the first part and the first tab and between the second part and the first protrusion, and also beneficial to reduce the phenomenon of the first current collector being damaged by tension. This is beneficial to improving the reliability of the cylindrical battery cell, and thus beneficial to improving the reliability of the battery device.

[0032] According to some embodiments of this application, the transition portion is bent to form multiple bent segments, which are connected in sequence, and the bent segments at both ends of the multiple bent segments are respectively connected to the second part and the first part.

[0033] In the above solution, by setting the transition portion as a structure of multiple bent segments connected in sequence by bending, and the bent segments at both ends of the multiple bent segments being connected to the first part and the second part respectively, the deformation capacity of the transition portion when the first part and the second part move closer or further away from each other along the first direction can be increased, thereby further improving the buffering effect of the transition portion between the first part and the second part, and further reducing the phenomenon of rigid tension between the first part and the second part, between the first part and the first tab, and between the second part and the first protrusion.

[0034] According to some embodiments of this application, the thickness of the transition portion is less than the thickness of the second portion; and / or the thickness of the transition portion is less than the thickness of the first portion.

[0035] In the above solution, by setting the thickness of the transition portion to be less than the thickness of the first portion, the manufacturing cost and difficulty of the first current collector component are reduced, while the ability of the transition portion to deform when the first portion and the second portion move closer or further apart along the first direction is improved, thus enabling the transition portion to play a better buffering role between the first portion and the second portion. Similarly, by setting the thickness of the transition portion to be less than the thickness of the second portion, the manufacturing cost and difficulty of the first current collector component are reduced, while the ability of the transition portion to deform when the first portion and the second portion move closer or further apart along the first direction is improved, thus enabling the first portion and the second portion to play a better buffering role.

[0036] According to some embodiments of this application, the first protrusion is an annular structure extending circumferentially along the sidewall.

[0037] In the above solution, by setting the first protrusion as a ring structure extending circumferentially along the sidewall, on the one hand, the limiting or positioning effect of the first protrusion on the electrode assembly and end cap can be further improved; on the other hand, it can be realized that the first protrusion can be welded to the second part of the first current collector at any position in the circumferential direction of the sidewall, so that the second part of the first current collector and the first protrusion can be welded to each other. This means that after the first current collector is assembled into the housing, the second part and the first protrusion can be welded together without rotating and adjusting the position of the first current collector. This helps to further reduce the welding difficulty between the second part of the first current collector and the first protrusion, thereby effectively improving the assembly efficiency of the cylindrical battery cell.

[0038] According to some embodiments of this application, a first groove is formed on the side of the sidewall away from the receiving cavity and corresponding to the position of the first protrusion.

[0039] In the above solution, by forming a first groove on the side of the sidewall facing away from the receiving cavity and at the position corresponding to the first protrusion, the first protrusion formed on the side of the sidewall facing the receiving cavity can be formed by stamping. This allows the first protrusion to be formed on the side of the sidewall facing the receiving cavity, and the first groove to be formed on the other side at the position corresponding to the first protrusion. Cylindrical battery cells with this structure can reduce the difficulty of forming the first protrusion on the side of the sidewall facing the receiving cavity, which is beneficial to improving the production efficiency of cylindrical battery cells. On the other hand, it can realize that the interior of the first protrusion is a hollow structure, which can reduce the power required for welding the first protrusion and the second part of the first current collector to each other, which is beneficial to reducing the welding difficulty between the first protrusion and the second part of the first current collector. Furthermore, it allows the first protrusion to have the ability of elastic deformation, which is beneficial to further alleviate the rigid tension between the second part of the first current collector and the first protrusion, thereby reducing the risk of weld detachment between the second part of the first current collector and the first protrusion.

[0040] According to some embodiments of this application, a protective layer is provided on the side of the sidewall away from the receiving cavity and at the position corresponding to the first protrusion.

[0041] In the above solution, a protective layer is provided on the side of the sidewall away from the receiving cavity and at the position corresponding to the first protrusion. This protective layer can cover the part of the sidewall that is worn or cracked due to the first groove formed by stamping, thus isolating the outside world from the worn or cracked part. This effectively reduces the risk of the sidewall being corroded, thereby effectively improving the reliability of the cylindrical battery cell and thus effectively improving the reliability of the battery device.

[0042] According to some embodiments of this application, the inner peripheral surface of the second protrusion forms an opening, and a protective layer is provided on the inner peripheral surface of the second protrusion.

[0043] In the above scheme, the inner circumferential surface of the second protrusion forms an opening, and the inner circumferential surface of the second protrusion has a cross-sectional structure. In this regard, by providing a protective layer on the inner circumferential surface of the second protrusion, the inner circumferential surface of the second protrusion can be isolated from the outside world, thereby reducing the risk that the inner circumferential surface of the second protrusion becomes the starting point of corrosion of the sidewall, so that the cylindrical battery cell has high reliability, and thus the battery device has high reliability.

[0044] According to some embodiments of this application, the inner peripheral surface of the second protrusion forms an opening. The battery cell also includes a seal, which comprises a first connecting portion and a second connecting portion connected to each other. Along a first direction, the first connecting portion is disposed between the end cap and the second protrusion, and the second connecting portion covers the inner peripheral surface of the second protrusion. Along the first direction, the second protrusion has a first surface facing away from the electrode assembly, and the second connecting portion has a second surface facing away from the electrode assembly. A protective layer is provided on both the first and second surfaces.

[0045] In the above solution, a seal is provided between the end cap and the second protrusion, which can improve the sealing level between the end cap and the side wall, reduce the risk of internal material leakage or external material entering the cylindrical battery cell, and make the cylindrical battery cell have high reliability. At the same time, by providing a protective layer on both the first and second surfaces, the risk of external material contacting the inner circumferential surface of the second protrusion and causing the casing to corrode can be effectively reduced, thereby improving the reliability of the cylindrical battery cell and thus improving the reliability of the battery device.

[0046] According to some embodiments of this application, the sealing element insulates the sealing end cap and the housing.

[0047] In the above solution, the sealing component serves two purposes: firstly, it seals the interior of the cylindrical battery cell, reducing the risk of external substances entering the cell; secondly, it provides insulation, reducing the risk of short circuits inside the cylindrical battery cell caused by the overlap of the end cap and the casing, thus ensuring high reliability of the battery cell.

[0048] According to some embodiments of this application, the sidewall includes a first subwall and a second subwall arranged along a first direction. Along the first direction, a first protrusion is located between the first subwall and the second subwall. The first subwall is connected to the first protrusion through a first transition section. The first protrusion is connected to the second subwall through a second transition section. The second subwall is connected to the second protrusion through a third transition section.

[0049] The outer surfaces of the first transition section, the second transition section, and the third transition section are all provided with protective layers.

[0050] In the above scheme, local plastic deformation of the sidewall forms a transition section, which allows for a smooth transition between the first sub-wall, the first protrusion, the second sub-wall, and the second protrusion. This reduces the risk of sidewall cracking due to stress concentration, improving the reliability of the cylindrical battery cell structure and consequently the reliability of the battery device. Simultaneously, a protective layer is provided on the outer surface of the transition section, isolating it from the outside environment and effectively reducing the risk of microcracks caused by local plastic deformation of the sidewall, leading to corrosion. This results in higher reliability for the cylindrical battery cell and, consequently, higher reliability for the battery device.

[0051] According to some embodiments of this application, the protective layer includes an anti-rust oil coating or a UV-cured layer.

[0052] In the above solution, by setting the protective layer to include an anti-rust oil coating or a UV curing layer, a variety of material options can be provided for the protective layer to meet different usage requirements and facilitate diversified choices for battery cell application scenarios.

[0053] According to some embodiments of this application, the protective layer includes an ultraviolet light fixing layer, the Vickers hardness of which is greater than or equal to 150.

[0054] In the above scheme, by setting the Vickers hardness of the protective layer to be greater than or equal to 150, it can effectively prevent rust and resist mechanical wear, thereby making the battery cell structure highly reliable and thus the battery device highly reliable.

[0055] Secondly, some embodiments of this application provide a battery device including the cylindrical battery cell provided in the first aspect.

[0056] Thirdly, some embodiments of this application provide an electrical device, which includes a cylindrical battery cell provided in the first aspect and / or a battery device provided in the second aspect.

[0057] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0058] 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.

[0059] Figure 1 This is a schematic diagram of a vehicle in some embodiments of this application;

[0060] Figure 2 This is an exploded perspective view of the battery device in some embodiments of this application;

[0061] Figure 3 These are perspective views of cylindrical battery cells in some embodiments of this application;

[0062] Figure 4 This is an exploded perspective view of a cylindrical battery cell in some embodiments of this application;

[0063] Figure 5 This is a schematic diagram of the internal structure of a cylindrical battery cell in some embodiments of this application;

[0064] Figure 6 for Figure 5 Enlarged view of point A in the middle;

[0065] Figure 7 This is a schematic diagram of the internal structure of a cylindrical battery cell in some other embodiments of this application;

[0066] Figure 8 for Figure 7 Enlarged view of point B in the middle;

[0067] Figure 9 This is a partial structural diagram of the first current collector, electrode assembly, and wall portion in some other embodiments of this application;

[0068] Figure 10 This is a schematic diagram of the internal structure of a cylindrical battery cell in some other embodiments of this application;

[0069] Figure 11 for Figure 10 Enlarged view of point C in the middle;

[0070] Figure 12 This is a schematic diagram of a partial structure of the housing, the first current collector, the seal, and the protective layer in other embodiments of this application.

[0071] icon:

[0072] 1000 - Vehicle; 100 - Battery unit; 200 - Controller; 300 - Motor; 20 - Housing; 21 - First housing body; 22 - Second housing body; 10 - Cylindrical battery cell; 11 - Housing; 11a - Wall; 110 - Housing; 111 - Side wall; 112 - Bottom wall; 113 - End cap; 1110 - First protrusion; 1111 - First groove; 1112 - Second protrusion; 1113 - First surface; 114 - Receiving cavity; 115 - Opening; 116 - First sub-wall; 1160 - First transition section; 1161 - Second transition section; 117- Second sub-wall; 1170- Third transition section; 12- Electrode assembly; 120- First electrode tab; 121- Second electrode tab; 123- Main body; 13- First current collector; 130- First part; 131- Second part; 132- Transition part; 133- Bending section; 14- Second current collector; 15- Electrode terminal; 16- Solder stamp; 17- Protective layer; 18- Plating; 19- Seal; 190- First connection part; 191- Second connection part; 192- Second surface; z- First direction. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0074] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0075] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0076] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0077] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0078] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0079] In this application, "multiple" means two or more (including two).

[0080] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0081] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0082] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, helps prevent short circuits to some extent while allowing active ions to pass through.

[0083] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0084] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0085] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0086] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM1), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM6), LiNi 0.8Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0087] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0088] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0089] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0090] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0091] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0092] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0093] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0094] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0095] In some embodiments, the separator is a separator membrane. The separator membrane can be of various types, and any known porous separator membrane with good chemical and mechanical stability can be selected.

[0096] As an example, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0097] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0098] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0099] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0100] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0101] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0102] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0103] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0104] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0105] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0106] In some implementations, the electrode assembly has a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0107] In some implementations, the electrode assembly has a stacked structure.

[0108] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0109] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0110] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0111] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0112] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0113] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0114] In some embodiments, the electrode assembly has tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0115] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be a steel housing, an aluminum housing, a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film, etc.

[0116] As an example, a single battery cell can be a cylindrical battery cell.

[0117] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple cylindrical battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0118] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple cylindrical battery cells into a single module. As an example, a battery module can be formed by bundling multiple cylindrical battery cells together with cable ties.

[0119] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0120] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0121] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple cylindrical battery cells to the housing.

[0122] As an example, the enclosure may include a first enclosure body and a second enclosure body. The first enclosure body and the second enclosure body are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, which can be either sealed or unsealed. The first enclosure body may be a top cover or a bottom plate.

[0123] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0124] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0125] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. The energy storage device includes energy storage containers, energy storage cabinets, etc. In some embodiments, one or more energy storage devices may constitute at least part of an energy storage system.

[0126] Battery devices possess outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide applicability, and low self-discharge coefficient, making them an important component of today's new energy development. The development of battery technology must simultaneously consider multiple design factors, such as performance parameters like energy density, cycle life, and discharge capacity. Furthermore, the reliability of the battery device must also be taken into account.

[0127] For a typical cylindrical battery cell, it usually includes a casing and an electrode assembly housed within the casing. The electrode assembly has tabs formed on it, which are connected to the wall of the casing, allowing the cylindrical battery cell to input or output electrical energy through the casing. In related technologies, to reduce the assembly difficulty between the tabs and the casing, a current collector is usually provided inside the casing. The casing and the tabs are connected by welding the current collector to achieve electrical connection between the tabs and the casing. However, the heat generated during the welding process between the current collector and the wall can affect the structural stability of the wall, leading to changes in the metal structure. This can easily cause cracks, allowing the interior of the wall to come into contact with the outside air, resulting in corrosion of the wall. This can lead to leakage of internal materials from the cylindrical battery cell or the entry of external materials into the cylindrical battery cell, affecting the reliability of the cylindrical battery cell and, consequently, the reliability of the battery device.

[0128] In view of this, to improve the problem that the wall of the casing is prone to corrosion due to the welding of the current collector to the wall, thereby affecting the reliability of the cylindrical battery cell, some embodiments of this application provide a cylindrical battery cell, which includes a casing, an electrode assembly, and a first current collector. The casing has a wall. The electrode assembly is disposed inside the casing and has a first tab. The first current collector is located inside the casing, and the first tab is electrically connected to the wall through the first current collector. The first current collector includes a first part and a second part that are interconnected. The first part is electrically connected to the first tab, and the second part is welded to the wall to form a solder mark. A protective layer is provided on the outer surface of the wall corresponding to the position of the solder mark.

[0129] In the above scheme, the first current collector is disposed inside the housing and is used to electrically connect the first tab and the wall. Specifically, a first portion of the first current collector is electrically connected to the first tab, and a second portion of the first current collector is welded to the wall to form a solder mark. By providing a protective layer on the outer surface of the wall corresponding to the solder mark, the area where the metal structure changes due to high temperatures during the welding process between the first current collector and the wall can be protected, reducing the risk of corrosion in the area corresponding to the solder mark. This reduces the risk of leakage of internal materials from the battery cell through this area, or the risk of the connection between the first current collector and the wall failing due to corrosion, leading to separation of the first current collector and the wall. This improves the reliability of the cylindrical battery cell and, consequently, the reliability of the battery assembly.

[0130] The battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft.

[0131] The technical solutions described in the embodiments of this application are applicable to battery devices, energy storage devices using battery devices, and electrical devices using battery devices.

[0132] Energy storage devices may include energy storage containers, energy storage cabinets, etc. For example, an energy storage cabinet may include a cabinet and one or more battery cells and / or battery devices mounted on the cabinet.

[0133] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be new energy vehicles, including pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The electrical devices in the embodiments of this application include, but are not limited to, those mentioned above.

[0134] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0135] Figure 1 This is a schematic diagram of vehicle 1000 in some embodiments of this application.

[0136] The electrical device is a vehicle 1000. Inside the vehicle 1000, a controller 200, a motor 300, and a battery device 100 can be installed. The controller 200 controls the battery device 100 to supply power to the motor 300. For example, the battery device 100 can be installed at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, it can serve as the operating power source for the vehicle 1000's electrical system, such as meeting the power requirements for starting, navigation, and operation. In another embodiment of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000 but also as the driving power source, replacing or partially replacing fuel or natural gas to provide driving power to the vehicle 1000.

[0137] Please refer to Figure 2 , Figure 2 This is an exploded perspective view of the battery device 100 in some embodiments of this application. The battery device 100 includes a housing 20 and cylindrical battery cells 10, which are housed within the housing 20.

[0138] The housing 20 provides an assembly space for the cylindrical battery cell 10, and the housing 20 can adopt various structures. In some embodiments, the housing 20 may include a first housing body 21 and a second housing body 22, which overlap each other, and together define an assembly space for accommodating the cylindrical battery cell 10. The second housing body 22 may be a hollow structure open at one end, and the first housing body 21 may be a plate-like structure, with the first housing body 21 covering the open side of the second housing body 22 so that the first housing body 21 and the second housing body 22 together define the assembly space; alternatively, the first housing body 21 and the second housing body 22 may both be hollow structures open on one side, with the open side of the first housing body 21 covering the open side of the second housing body 22.

[0139] Of course, the box 20 formed by the first box body 21 and the second box body 22 can be of various shapes, such as cylinder, cuboid or cube.

[0140] In the battery device 100, there can be one or more cylindrical battery cells 10 disposed within the housing 20. When there are multiple cylindrical battery cells 10 disposed within the housing 20, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that the multiple cylindrical battery cells 10 are connected in both series and parallel configurations. The multiple cylindrical battery cells 10 can be directly connected in series, in parallel, or in a mixed configuration together, and then the entire assembly of the multiple cylindrical battery cells 10 is housed within the housing 20. Alternatively, the battery device 100 can also be composed of multiple cylindrical battery cells 10 first connected in series, in parallel, or in a mixed configuration to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 20.

[0141] In some embodiments, the battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar for connecting multiple cylindrical battery cells 10 to achieve electrical connection between the multiple cylindrical battery cells 10.

[0142] Each cylindrical battery cell 10 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited to these.

[0143] Some embodiments of this application provide a cylindrical battery cell 10; please refer to [link to relevant documentation]. Figures 3-6 , Figure 3 This is a perspective view of the cylindrical battery cell 10 in some embodiments of this application. Figure 4 This is an exploded perspective view of the cylindrical battery cell 10 in some embodiments of this application. Figure 5 This is a schematic diagram of the internal structure of the cylindrical battery cell 10 in some embodiments of this application. Figure 6 for Figure 5 Enlarged view of point A in the middle.

[0144] The cylindrical battery cell 10 includes a housing 11, an electrode assembly 12, and a first current collector 13. The housing 11 has a wall portion 11a. The electrode assembly 12 is disposed within the housing 11 and has a first tab 120. The first current collector 13 is located within the housing 11, and the first tab 120 is electrically connected to the wall portion 11a through the first current collector 13. The first current collector 13 includes a first portion 130 and a second portion 131 that are interconnected. The first portion 130 is electrically connected to the first tab 120, and the second portion 131 is welded to the wall portion 11a to form a solder mark 16. A protective layer 17 is provided on the outer surface of the wall portion 11a corresponding to the position of the solder mark 16.

[0145] The outer shell 11 can also be used to contain electrolytes, such as electrolyte solutions. The outer shell 11 can have various structural forms. The outer shell 11 can also be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0146] In some embodiments, the housing 11 may include a housing 110 and an end cap 113. The housing 110 has an internal cavity 114 with an opening 115. The opening 115 is located at one end of the housing 110 in the first direction z, that is, the housing 110 is a hollow structure with one end open in the first direction z. The end cap 113 covers the opening 115 of the housing 110 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 12 and the electrolyte. Correspondingly, the thickness direction of the end cap 113 is the first direction z.

[0147] The housing 110 may include a bottom wall 112 and a side wall 111. The side wall 111 surrounds the bottom wall 112. Along the first direction z, one end of the side wall 111 is connected to the bottom wall 112, and the other end forms an opening 115. The end cap 113 is disposed opposite to the bottom wall 112 in the first direction z.

[0148] Optionally, the wall portion 11a, which is welded to the second part 131 of the first current collector 13, can be a side wall 111 or a bottom wall 112 of the housing 110, or an end cap 113 of the outer shell 11. For example, the wall portion 11a is a side wall 111 of the housing 110, and correspondingly, the second part 131 of the first current collector 13 is welded to the side wall 111 of the housing 110, forming a welded portion. Of course, in other embodiments, the wall portion 11a can also be the bottom wall 112 of the housing 110, or an end cap 113 of the outer shell 11.

[0149] The cylindrical battery cell 10 is cylindrical, and the axial direction of the cylindrical battery cell 10 is the first direction z, that is, the central axis of the cylindrical battery cell 10 extends along the first direction z. The radial direction of the cylindrical battery cell 10 is perpendicular to the first direction z. The radial direction of the cylindrical battery cell 10 is in the projection plane perpendicular to the first direction z. The central axis of the cylindrical battery cell 10 points to the outer peripheral surface of the cylindrical battery cell 10 or the outer peripheral surface of the cylindrical battery cell 10 points to the central axis of the cylindrical battery cell 10. Correspondingly, the side wall 111 of the housing 110 is also a cylindrical structure, and the central axis of the housing 110 extends along the first direction z, so that the projection of the end cap 113 in the first direction z is circular.

[0150] Understandably, the outer casing 11 is not limited to the structure described above. The outer casing 11 can also be other structures. For example, the outer casing 11 includes a housing 110 and two end caps 113. The housing 110 is a hollow structure with openings 115 on both sides. One end cap 113 is fitted onto one opening 115 of the housing 110 to form a sealed connection, thereby forming a sealed space for accommodating the electrode assembly 12 and the electrolyte. That is, the housing 110 of the outer casing 11 only includes a side wall 111. The side wall 111 is a hollow structure with openings 115 at both ends in the first direction z. The two end caps 113 are respectively fitted onto the openings 115 at both ends of the side wall 111 in the first direction z.

[0151] It should be noted that the electrode assembly 12 is the component in the cylindrical battery cell 10 where the electrochemical reaction occurs. The electrode assembly 12 includes a main body 123, a first tab 120, and a second tab 121. The main body 123 is the main component of the electrode assembly 12 where the electrochemical reaction occurs in the cylindrical battery cell 10, while the first tab 120 and the second tab 121 serve to output or input electrical energy into the electrode assembly 12. The structure of the main body 123 of the electrode assembly 12 can be varied. For example, in... Figure 4 In the electrode assembly 12, the main body 123 is a wound structure formed by winding a portion of the positive electrode, a portion of the separator, and a portion of the negative electrode. The main body 123 of the electrode assembly 12 has a cylindrical structure, and the central axis of the main body 123 of the electrode assembly 12 extends along the first direction z.

[0152] For example, the separator is a separator membrane, and the main material of the separator membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.

[0153] Optionally, the electrode assembly 12 housed within the housing 11 can be one or more. For example, in... Figure 4 In this embodiment, only one electrode assembly 12 is disposed within the outer casing 11 of the cylindrical battery cell 10. Of course, the structure of the cylindrical battery cell 10 is not limited to this. In other embodiments, the electrode assembly 12 housed within the outer casing 11 may be two, three, four, five, six, seven, or eight, etc.

[0154] The first electrode 120 and the second electrode 121 have opposite polarities, and are used as the positive and negative electrodes of the input or output electrode assembly 12, respectively. Figure 5 and Figure 6 In the middle, the first electrode 120 and the second electrode 121 are respectively connected to the two ends of the main body 123 in the first direction z. The first electrode 120 is located at the end of the main body 123 facing the end cover 113, and the second electrode 121 is located at the end of the main body 123 away from the end cover 113.

[0155] It should be noted that if the first tab 120 is the positive tab of the electrode assembly 12, then the first tab 120 is a component formed by stacking and connecting the regions on the positive electrode sheet that are not coated with the positive active material layer. Correspondingly, if the second tab 121 is the negative tab of the electrode assembly 12, then the second tab 121 is a component formed by stacking and connecting the regions on the negative electrode sheet that are not coated with the negative active material layer. Conversely, if the first tab 120 is the negative tab of the output electrode assembly 12, then the first tab 120 is a component formed by stacking and connecting the regions on the negative electrode sheet that are not coated with the negative active material layer. Correspondingly, if the second tab 121 is the positive tab of the electrode assembly 12, then the second tab 121 is a component formed by stacking and connecting the regions on the positive electrode sheet that are not coated with the positive active material layer.

[0156] Optionally, the first current collector 13 can be made of various materials, such as copper, iron, aluminum, steel or aluminum alloy.

[0157] The second part 131 of the first current collector 13 is welded to the wall part 11a to form a weld mark 16. It should be noted that the weld mark 16 is the area where the second part 131 of the first current collector 13 is welded to the wall part 11a to form a fused area or a weld mark area.

[0158] Optionally, the welding connection between the first current collector 13 and the wall 11a can be of various types, such as laser welding or ultrasonic welding.

[0159] The first part 130 of the first current collector 13 is connected to the first tab 120, so that the first tab 120 is a structure that is interconnected with the wall portion 11a through the first current collector 13, so as to realize the electrical connection between the electrode assembly 12 and the wall portion 11a, thereby making the wall portion 11a an output electrode of the cylindrical battery cell 10.

[0160] Optionally, the first portion 130 of the first current collector 13 is disposed at one end of the electrode assembly 12 in the first direction z near the end cap 113, and the first portion 130 is connected to the first tab 120 to realize the electrical connection between the first current collector 13 and the first tab 120. Optionally, the first portion 130 is connected to the side of the first tab 120 away from the main body 123 in the first direction z. The connection structure between the first portion 130 and the first tab 120 can be various, such as welding connection or bonding.

[0161] Optionally, the second part 131 is located on the side of the first part 130 facing the end cap 113 along the first direction z, and the second part 131 is spaced apart from the first part 130. That is, the first part 130 and the second part 131 are arranged at intervals along the first direction z, and the two are electrically connected by other structures, such as the first part 130 and the second part 131 being connected by a transition part 132.

[0162] Optionally, the second part 131 is directly connected to the first part 130, with one end of the second part 131 connected to the first part 130 and the other end extending toward the end cap 113 along the first direction z.

[0163] Optionally, the second part 131 is stacked with the wall part 11a, and the surface of the second wall part 11a is in contact with the inner surface of the wall part 11a.

[0164] Optionally, the end of the second part 131 is in contact with the inner side of the wall 11a, and the solder mark 16 connects the end of the second part 131 and the inner side of the wall 11a.

[0165] It should be noted that the second part 131 is stacked with the wall part 11a. In the stacking direction of the second part 131 and the wall part 11a, the solder mark 16 can be a structure that penetrates the second part 131 or a structure that does not penetrate the second part 131. For example, in Figure 6 In the middle, the solder mark 16 does not penetrate the second part 131, in Figure 8 The middle soldering section 16 penetrates the second part 131.

[0166] It should be noted that the second part 131 is stacked with the wall portion 11a. In the stacking direction of the second part 131 and the wall portion 11a, the solder mark 16 can be a structure that penetrates the wall portion 11a or a structure that does not penetrate the wall portion 11a. For example, in Figure 6 In the middle, the solder mark 16 penetrates the wall portion 11a, in Figure 8 The middle solder mark 16 does not penetrate the wall portion 11a.

[0167] In some embodiments, see Figure 5 and Figure 6 The wall portion 11a is a side wall 111, which has a straight structure. The thickness direction of the wall portion 11a is perpendicular to the first direction z. The second part 131 is stacked with the wall portion 11a, and the stacking direction of the two is parallel to the thickness direction of the wall portion 11a.

[0168] In some embodiments, see Figure 7 and Figure 8 , Figure 7 This is a schematic diagram of the internal structure of a cylindrical battery cell in other embodiments of this application. Figure 8 for Figure 7 In the enlarged view at point B, wall portion 11a is a sidewall 111. A partial indentation in the sidewall 111 forms a first protrusion 1110 on its inner side. Corresponding to the position of the first protrusion 1110, a first groove 1111 is formed on the outer side of the sidewall 111. The second portion 131 is stacked with the first protrusion 1110, and their stacking direction is parallel to the first direction z.

[0169] A protective layer 17 is provided on the outer surface of the wall portion 11a corresponding to the position of the solder mark portion 16. The outer surface of the wall portion 11a can be understood as the wall portion 11a being away from the surface of the second part 131 along the thickness direction of the wall portion 11a.

[0170] A protective layer 17 is provided on the outer surface of the wall portion 11a corresponding to the position of the solder mark portion 16. It can be understood that the protective layer 17 is provided on the outer surface of the wall portion 11a, and the position of the protective layer 17 corresponds to the position of the solder mark portion 16, so that the protective layer 17 can cover the part where the solder mark portion 16 is located.

[0171] Understandably, a protective layer 17 is provided on the outer side of the wall portion 11a corresponding to the position of the solder mark portion 16. The specific position of the protective layer 17 on the outer side of the wall fabric is not limited, as long as it can at least correspond to the position of the solder mark portion 16. The protective layer 17 can also be provided in other areas of the wall portion 11a. For example, when the wall portion 11a is a side wall 111, the protective layer 17 covers the entire outer side of the side wall 111, or the protective layer 17 covers a part of the outer side of the side wall 111.

[0172] For example, taking the second part 131 and the wall part 11a as an example, on the same projection plane perpendicular to the stacking direction of the second part 131 and the wall part 11a, the projection of the protective layer 17 at least partially overlaps with the projection of the solder mark 16, or the projection of the protective layer 17 can cover the projection of the solder mark 16.

[0173] The protective layer 17 is used to isolate the outer surface of the wall portion 11a corresponding to the location of the solder mark 16 from the outside world, so as to reduce the risk of external substances directly contacting the outer surface of the wall portion 11a corresponding to the location of the solder mark 16, causing the wall portion 11a to be corroded.

[0174] Alternatively, the protective layer 17 can be made of various materials, including but not limited to metals, oils, and polymers.

[0175] For example, the protective layer 17 can be a metal plating layer 18 disposed on the outer side of the wall portion 11a, such as a nickel plating layer, a zinc plating layer, etc.

[0176] For example, the protective layer 17 may be a rust-preventive oil applied to the outer surface of the wall portion 11a.

[0177] For example, the protective layer 17 may be an ultraviolet curing layer disposed on the outer side of the wall portion 11a.

[0178] In some embodiments, see Figure 3 , Figure 4 and Figure 5 As shown, the cylindrical battery cell 10 may further include an electrode terminal 15, which is insulated and mounted on a wall of the housing 11 facing the second tab 121 in the first direction z. The electrode terminal 15 is electrically connected to the second tab 121, so that the electrode terminal 15 serves as another output electrode of the cylindrical battery cell 10, thereby enabling the input or output of electrical energy of the cylindrical battery cell 10 through the electrode terminal 15 and the wall portion 11a.

[0179] The electrode terminal 15 is insulatedly mounted on a wall of the housing 11 facing the second tab 121 in the first direction z. That is, the electrode terminal 15 is mounted on the end of the housing 110 away from the end cover 113 in the first direction z, and an insulating element is provided between the electrode terminal 15 and the housing 11, so that no electrical connection is formed between the electrode terminal 15 and the housing 11.

[0180] See Figure 5 As shown, the electrode terminal 15 is riveted to the bottom wall 112 of the housing 110. That is, the bottom wall 112 of the housing 110 is provided with mounting holes, which penetrate both sides of the bottom wall 112 of the housing 110 along the first direction z, and a portion of the electrode terminal 15 passes through the mounting holes. Of course, in other embodiments, the electrode terminal 15 may also be snap-fitted or glued to the outer shell 11.

[0181] For example, the electrode terminal 15 can be made of various materials, such as copper, iron, aluminum, steel or aluminum alloy.

[0182] In some embodiments, see Figure 4 and Figure 5 As shown, the cylindrical battery cell 10 may further include a second current collector 14, which is disposed in the first direction z between the second tab 121 and the electrode terminal 15 of the electrode assembly 12. The second current collector 14 connects the second tab 121 and the electrode terminal 15 to electrically connect the electrode assembly 12 and the electrode terminal 15.

[0183] Optionally, the connection structure between the second current collector 14 and the second electrode tab 121, and between the second current collector 14 and the electrode terminal 15, can be various, such as welding connection or bonding.

[0184] For example, the material of the second current collector 14 can be various, such as copper, iron, aluminum, steel or aluminum alloy.

[0185] It should be noted that in other embodiments, the second tab 121 of the electrode assembly 12 may also be a structure that is directly connected to the electrode terminal 15, such as by welding or bonding.

[0186] Optionally, the housing 11 may also be provided with a pressure relief mechanism, which is used to release the pressure inside the cylindrical battery cell 10. Various types of pressure relief mechanisms may be provided, including but not limited to pressure relief valves and pressure relief grooves.

[0187] In the above scheme, the first current collector 13 is disposed inside the housing 11 and is used to electrically connect the first tab 120 and the wall portion 11a. Specifically, the first portion 130 of the first current collector 13 is electrically connected to the first tab 120, and the second portion 131 of the first current collector 13 is welded to the wall portion 11a to form a solder mark 16. By providing a protective layer 17 on the outer surface of the wall portion 11a corresponding to the solder mark 16, the area where the metal structure changes due to high temperature during the welding process between the first current collector 13 and the wall portion 11a can be protected, reducing the risk of corrosion in the area corresponding to the solder mark 16. This reduces the risk of leakage of internal materials from the battery cell from this area, or the risk of the connection between the first current collector 13 and the wall portion 11a failing due to corrosion of the wall portion 11a, leading to separation of the first current collector 13 and the wall portion 11a. This improves the reliability of the cylindrical battery cell 10 and, consequently, the reliability of the battery device 100.

[0188] According to some embodiments of this application, a plating layer 18 is provided on the outer surface of the wall portion 11a, and at least a portion of the plating layer 18 is located between the protective layer 17 and the outer surface of the wall portion 11a.

[0189] In some embodiments, the outer surface of the wall covering is provided with a coating 18, and the material of the coating 18 includes, but is not limited to, metal, non-metal or metal-based composite material.

[0190] For example, the coating 18 can be a zinc plating layer, a nickel plating layer, or a nanocomposite coating 18.

[0191] In some embodiments, the fact that at least a portion of the plating 18 is located between the protective layer 17 and the outer surface of the wall portion 11a can be understood as follows: all of the plating 18 is located between the protective layer 17 and the outer surface of the wall portion 11a; or a portion of the plating 18 is located between the protective layer 17 and the wall portion 11a, and the remaining portion of the plating 18 is not provided with the protective layer 17 on the side away from the wall portion 11a; or the plating 18 is provided on the outer surface of the wall portion 11a, and a portion of the protective layer 17 has a plating 18 between it and the wall portion 11a, or a portion of the protective layer 17 does not have a plating 18 between it and the wall portion 11a.

[0192] Optionally, please see Figure 6The plating layer 18 is disposed on the outer surface of the wall portion 11a. At the location of the corresponding solder mark portion 16, part of the protective layer 17 is in direct contact with the outer surface of the wall portion 11a, while the remaining part of the protective layer 17 is disposed between the protective layer 17 and the wall portion 11a and the plating layer 18.

[0193] In the above solution, by providing a coating 18 on the outer surface of the wall portion 11a, it can, on the one hand, improve the surface hardness of the wall portion 11a, reducing the impact of external materials on the wall portion 11a that could cause the first current collector 13 to separate from the wall portion 11a, thus giving the battery cell higher reliability; on the other hand, it can also prevent corrosion, isolating the casing wall portion 11a from the outside environment, reducing the risk of leakage of internal materials of the battery cell due to corrosion of the wall portion 11a, thus giving the battery cell higher reliability, and consequently giving the battery device 100 higher reliability. At the same time, providing a protective layer 17 on the outside of the coating 18 can effectively reduce the risk of corrosion of the wall portion 11a due to cracking of the coating 18 under stress, further improving the reliability of the cylindrical battery cell 10 and the battery device 100.

[0194] In other embodiments, such as Figure 8 The outer surface of the wall portion 11a is provided with a plating layer 18, while the protective layer 17 is not provided with a plating layer 18 between it and the outer surface of the wall portion 11a. Optionally, the plating layer 18 and the protective layer 17 can be provided alternately. Optionally, the plating layer 18 and the protective layer 17 can be connected to each other.

[0195] In some other embodiments, the outer surface of the wall portion 11a may not be provided with the plating layer 18.

[0196] According to some embodiments of this application, the outer shell 11 is a steel shell, and the plating layer 18 is a nickel plating layer.

[0197] In some embodiments, the outer casing 11 is made of steel and has a nickel-plated layer on its surface.

[0198] In the above scheme, by setting the casing 110 as a steel casing, the structural strength of the casing 11 can be improved, and the impact resistance of the battery cell can be enhanced. On the other hand, the thickness of the casing 11 can be reduced to accommodate more electrochemical substances, thereby improving the volumetric energy density of the battery cell. At the same time, by setting a nickel plating layer on the surface of the steel casing, the risk of corrosion of the steel casing can be effectively reduced, which is beneficial to improving the reliability of the battery cell and the battery device 100. On the other hand, it is beneficial to weld the first current collector 13 to the wall 11a, which is beneficial to improving the welding quality, thereby improving the reliability of the cylindrical battery cell 10, and further improving the reliability of the battery device 100.

[0199] According to some embodiments of this application, the second portion 131 and the wall portion 11a are stacked. One end of the solder mark portion 16 protrudes from the side of the second portion 131 away from the wall portion 11a, and the other end of the solder mark portion 16 is embedded in the wall portion 11a and does not protrude from the side of the wall portion 11a away from the second portion 131.

[0200] Optionally, please see Figure 8 The second part 131 and the wall part 11a are stacked and connected by welding to form a solder mark 16. Along the stacking direction of the second part 131 and the wall part 11a, that is, along the first direction z, one end of the solder mark protrudes from the side of the second part 131 away from the wall part 11a, and the other end of the solder mark 16 is embedded in the wall part 11a and does not protrude from the side of the wall part 11a away from the second part 131.

[0201] For example, along the first direction z, the welding head is located on the side of the second part 131 away from the wall part 11a, and the second part 131 and the wall part 11a are welded together. During the welding process, the molten pool does not pass through the outer side of the wall part 11a, so that the weld mark 16 does not protrude from the outer side of the wall part 11a.

[0202] In some embodiments, one end of the solder mark 16 protrudes from the side of the wall portion 11a away from the second portion 131, and the other end of the solder mark 16 is embedded in the second portion 131 and does not protrude from the side of the second portion 131 away from the wall portion 11a.

[0203] In some embodiments, see Figure 6 The second part 131 and the wall part 11a are stacked together and welded together to form a solder mark 16. Along the stacking direction of the second part 131 and the wall part 11a, that is, along the thickness direction of the wall part 11a, one end of the solder mark protrudes from the side of the wall part 11a away from the second part 131, and the other end of the solder mark 16 is embedded in the second part 131 and does not protrude from the side of the second part 131 away from the wall part 11a.

[0204] For example, the welding head is located on the side of the wall portion 11a away from the second portion 131, and the wall portion 11a and the second portion 131 are welded together. During the welding process, the molten pool does not pass through the side of the second portion 131 away from the wall portion 11a, so that the solder mark portion 16 does not protrude from the side of the second portion 131 away from the wall portion 11a.

[0205] In the above scheme, the second part 131 of the first current collector 13 is stacked with the wall part 11a, which facilitates the welding of the second part 131 and the wall part 11a and results in high welding quality.

[0206] In some embodiments where the second part 131 and the wall portion 11a are stacked, by setting the solder mark 16 so that one end protrudes from the side of the second part 131 away from the wall portion 11a, and the other end does not protrude from the side of the wall portion 11a away from the second part 131, the impact of the solder mark 16 on the structural reliability of the wall portion 11a can be reduced. That is, the impact of the heat generated during the welding process between the second part 131 and the wall portion 11a on the wall portion 11a can be reduced, thereby reducing the risk of corrosion of the wall portion 11a, which is beneficial to improving the reliability of the cylindrical battery cell 10, and further beneficial to improving the reliability of the battery device 100.

[0207] In some other embodiments where the second part 131 and the wall part 11a are stacked, by setting the solder portion 16 to have one end protruding from the side of the wall part 11a away from the second part 131 and the other end not protruding from the side of the second part 131 away from the wall part 11a, on the one hand, the influence of the solder portion 16 on the structural components of the second part 131 away from the wall part 11a and located inside the outer casing 11 can be reduced, thus ensuring the structural reliability of the internal structural components of the cylindrical battery cell 10 to a certain extent, thereby improving the reliability of the cylindrical battery cell 10 and thus improving the reliability of the battery device 100; on the other hand, the space occupied by the solder portion 16 in the internal space of the cylindrical battery cell 10 can be reduced, thereby allowing more active material to be placed inside the outer casing 11, which is conducive to improving the volumetric energy density of the cylindrical battery cell 10 and thus improving the volumetric energy density of the battery device 100.

[0208] According to some embodiments of this application, the second part 131 and the wall part 11a are stacked, one end of the solder mark 16 protrudes from the side of the second part 131 away from the wall part 11a, and the other end of the solder mark 16 protrudes from the side of the wall part 11a away from the second part 131.

[0209] Optionally, please see Figure 9 , Figure 9 This is a partial structural diagram of the first current collector 13, electrode assembly 12, and wall portion 11a in other embodiments of this application. The second portion 131 and the wall portion 11a are stacked and welded together to form a solder mark 16. Along the stacking direction of the second portion 131 and the wall portion 11a, one end of the solder mark protrudes from the side of the wall portion 11a away from the second portion 131, and the other end of the solder mark 16 protrudes from the side of the second portion 131 away from the wall portion 11a.

[0210] For example, along the stacking direction of the second part 131 and the wall part 11a, the welding head is located on the side of the second part 131 away from the wall part 11a, and the second part 131 and the wall part 11a are welded together. During the welding process, the molten pool melts through the second part 131 and the wall part 11a, so that the two ends of the solder mark 16 protrude from the second part 131 and the wall part 11a respectively.

[0211] In the above scheme, the second part 131 of the first current collector 13 is stacked with the wall part 11a, and the two ends of the solder part 16 protrude from the opposite sides of the second part 131 and the wall part 11a, which can effectively improve the welding quality of the second part 131 and the wall part 11a, reduce the risk of the second part and the wall part 11a separating due to external or internal impacts on the cylindrical battery cell 10, thereby improving the reliability of the cylindrical battery cell 10 and thus improving the reliability of the battery device 100.

[0212] According to some embodiments of this application, the housing 11 includes a housing 110 and an end cap 113. The housing 110 includes an integrally formed sidewall 111 and a bottom wall 112. The sidewall 111 surrounds the bottom wall 112. Along a first direction z, one end of the sidewall 111 is connected to the bottom wall 112, and the other end forms an opening 115. The sidewall 111 and the bottom wall 112 together define a receiving cavity 114, in which the electrode assembly 12 is received. The first direction z is the axial direction of the housing 110. The end cap 113 closes the opening 115. The wall portion 11a is either the sidewall 111 or the bottom wall 112.

[0213] Optionally, the housing 110 includes an integrally formed sidewall 111 and bottom wall 112, that is, the sidewall 111 and bottom wall 112 of the housing 110 are structures formed by an integral forming process, such as stamping or casting.

[0214] A side wall 111 surrounds the bottom wall 112. Along the first direction z, one end of the side wall 111 is connected to the bottom wall 112, and the other end forms an opening 115. That is, the side wall 111 is a ring-shaped structure surrounding the bottom wall 112, and is a hollow structure with open ends in the first direction z. One end of the side wall 111 in the first direction z is connected to the bottom wall 112. Figure 4 In the cylindrical battery cell 10, the outer shell 11 is a cylindrical structure, and the central axis of the outer shell 11 extends along the first direction z. Correspondingly, the side wall 111 is also a hollow cylindrical structure with the central axis extending along the first direction z, so that the projections of the bottom wall 112 and the end cap 113 in the first direction z are both circular.

[0215] The wall portion 11a is either a side wall 111 or a bottom wall 112. That is, the second connection area of ​​the first current-collecting member 13 can be a structure welded to the side wall 111 of the housing 110, or it can be a structure welded to the bottom wall 112 of the housing 110. For example, in... Figure 6 In the middle, the wall portion 11a is the side wall 111 of the shell 110, and the second part 131 of the first current collector 13 is welded to the side wall 111 of the shell 110 to form a weld mark portion 16.

[0216] In the above solution, by setting the side wall 111 or bottom wall 112 of the housing 110 as a wall portion 11a, the second part 131 of the first current collector 13 is a structure welded to the side wall 111 or bottom wall 112 of the housing 110. This can alleviate the stress generated by the pulling or twisting of the first current collector 13 on the wall portion 11a and put it on the end cap 113, thereby reducing the risk of connection failure between the end cap 113 and the housing 110, and thus effectively improving the reliability of the cylindrical battery cell 10.

[0217] According to some embodiments of this application, please refer to Figure 8 and Figure 9 The wall portion 11a is a sidewall 111. A first protrusion 1110 is provided on the side of the sidewall 111 facing the receiving cavity 114, and a second protrusion 1112 is provided at the end of the sidewall 111 away from the bottom wall 112 in the first direction z. Along the first direction z, at least a portion of the electrode assembly 12 is located on the side of the first protrusion 1110 away from the second protrusion 1112, and the end cap 113 is located between the first protrusion 1110 and the second protrusion 1112.

[0218] Along the first direction z, the first protrusion 1110 and the second protrusion 1112 are arranged at intervals, the end cap 113 is located between the first protrusion 1110 and the second protrusion 1112, and at least a portion of the electrode assembly 12 is located on the side of the first protrusion 1110 opposite to the second protrusion 1112.

[0219] The fact that at least a portion of the electrode assembly 12 is located on the side of the first protrusion 1110 opposite to the second protrusion 1112 can be understood as the entire electrode assembly 12 being located on the side of the first protrusion 1110 opposite to the second protrusion 1112. For example, please refer to [link to relevant documentation]. Figure 8 The entire electrode assembly 12 is located on the side of the first protrusion 1110 opposite to the second protrusion 1112. Alternatively, it can be understood that a portion of the electrode assembly 12 is located on the side of the first protrusion 1110 opposite to the second protrusion 1112, for example, the main body 123 of the electrode assembly 12 is located on the side of the first protrusion 1110 opposite to the second protrusion 1112, and the first tab 120 of the electrode assembly 12 is inserted into the inner circumferential side of the first protrusion 1110.

[0220] The first protrusion 1110 is a convex hull structure provided on the inner side of the side wall 111.

[0221] Optionally, the first protrusion 1110 and the sidewall 111 are integrally formed. For example, the first protrusion 1110 is formed by partial deformation of the sidewall 111 and recess into the sidewall 111. Exemplarily, the first protrusion 1110 can be formed on the housing 110 by processes such as stamping and rolling.

[0222] Optionally, the first protrusion 1110 and the sidewall 111 are separate structures, and the first protrusion 1110 is a block structure connected to the inner surface of the sidewall 111. For example, the first protrusion 1110 is a protrusion, which is connected to the sidewall 111 by welding, bonding or snapping.

[0223] The second protrusion 1112 is a protruding structure at the opening 115 end of the side wall 111.

[0224] Optionally, the second protrusion 1112 and the sidewall 111 can be integrally formed. For example, the second protrusion 1112 is a flanged structure formed by folding the part of the sidewall 111 located at one end of the opening 115 toward the inside of the sidewall 111.

[0225] Optionally, the second protrusion 1112 and the sidewall 111 are separate structures. For example, the second protrusion 1112 is an independent structure and is connected to the opening 115 end of the sidewall 111. Exemplarily, the second protrusion 1112 is a retaining ring, which is connected to the opening 115 end of the sidewall 111. The connection between the retaining ring and the sidewall 111 includes, but is not limited to, bonding, welding, threaded connection, etc.

[0226] In the above scheme, a first protrusion 1110 and a second protrusion 1112 are provided on the sidewall 111, and at least a portion of the electrode assembly 12 is located on the side of the first protrusion 1110 away from the second protrusion 1112. The end cap 113 is located between the first protrusion 1110 and the second protrusion 1112. The cylindrical battery cell 10 with this structure can limit or position the electrode assembly 12 and the end cap 113 to a certain extent through the first protrusion 1110 and the second protrusion 1112, which helps to reduce the assembly difficulty of the cylindrical battery cell 10, so that the cylindrical battery cell 10 has high manufacturing efficiency, and thus the battery device 100 has high manufacturing efficiency.

[0227] According to some embodiments of this application, the second portion 131 is welded to the first protrusion 1110 to form a solder mark portion 16.

[0228] In some embodiments, the second portion 131 of the first current collector 13 is welded to the first protrusion 1110 to form a solder mark 16.

[0229] Optionally, the end of the second part 131 is welded to the first protrusion 1110 to form a solder mark 16.

[0230] Optionally, the second part 131 is stacked with the first protrusion 1110, and the two are welded together to form a solder mark 16.

[0231] In the above scheme, the first protrusion 1110 is welded to the second part 131 to form a solder mark 16. The cylindrical battery cell 10 with this structure can make reasonable use of the first protrusion 1110, which plays a role in limiting and positioning, to weld to the first current collector 13. This can reduce the welding difficulty between the second part 131 of the first current collector 13 and the wall 11a, thereby reducing the difficulty of assembling the first current collector 13 into the housing 11, and thus improving the manufacturing efficiency of the battery device 100.

[0232] According to some embodiments of this application, please refer to Figure 8 Along the first direction z, the second part 131 is welded to the side of the first protrusion 1110 facing the end cap 113 to form a weld mark 16.

[0233] In some embodiments, along the first direction z, the second portion 131 is located on the side of the first protrusion 1110 facing the end cap 113. That is, the area of ​​the first current collector 13 for welding the first protrusion 1110 is located on the side of the first protrusion 1110 facing the end cap 113 in the first direction z, such that the electrode assembly 12 and the second portion 131 are located on both sides of the first protrusion 1110 in the first direction z.

[0234] The second part 131 is welded to the side of the first protrusion 1110 facing the end cap 113 to form a weld mark 16. That is, the second part 131 of the first current collector 13 is a structure that is welded to the side of the first protrusion 1110 facing the end cap 113.

[0235] In the above scheme, the electrode assembly 12 is located on the side of the first protrusion 1110 facing away from the end cover 113. The first current collector 13 is connected to the first tab 120 of the electrode assembly 12, and the second part 131 of the first current collector 13 is located on the side of the first protrusion 1110 facing the end cover 113 and is welded to the side of the first protrusion 1110 facing the end cover 113. This structure of the cylindrical battery cell 10 allows the first current collector 13 and the first protrusion 1110 to share a portion of the space in the first direction z, which is beneficial for improving the performance of the cylindrical battery cell 10. The internal space utilization is improved to increase the volumetric energy density of the cylindrical battery cell 10. On the other hand, the second part 131 of the first current collector 13 is located on the side of the first protrusion 1110 facing the opening 115 of the housing 110 in the first direction z and is welded to the surface of the first protrusion 1110 facing the opening 115. This allows the first protrusion 1110 and the second part 131 to be welded together from the opening 115 of the housing 110, which is beneficial to optimizing the manufacturing process of the cylindrical battery cell 10 and reducing the assembly difficulty of the cylindrical battery cell 10.

[0236] According to other embodiments of this application, please refer to Figure 10 and Figure 11 , Figure 10 This is a schematic diagram of the internal structure of a cylindrical battery cell in other embodiments of this application. Figure 11 for Figure 10 Enlarged view at point C. Along the first direction z, the second part 131 is welded to the side of the first protrusion 1110 away from the end cap 113 to form a solder mark 16.

[0237] In some embodiments, along the first direction z, the second portion 131 is located on the side of the first protrusion 1110 away from the end cap 113. That is, the area of ​​the first current collector 13 for welding the first protrusion 1110 is located on the side of the first protrusion 1110 away from the end cap 113 in the first direction z, such that the electrode assembly 12 and the second portion 131 are located on the same side of the first protrusion 1110 in the first direction z.

[0238] The second part 131 is welded to the side of the first protrusion 1110 away from the end cap 113 to form a weld mark 16. That is, the second part 131 of the first current collector 13 is a structure that is welded to the side of the first protrusion 1110 away from the end cap 113.

[0239] In the above technical solution, by setting the second part 131 of the first current collector 13 to be located on the side of the first part 130 away from the end cover 113 in the first direction z and welding it to the side of the first part 130 away from the end cover 113, the second part 131 of the first current collector 13 and the electrode assembly 12 are both located on the side of the first protrusion away from the end cover 113. This helps to reduce the assembly difficulty of the first current collector 13 and the electrode assembly 12. In addition, the first protrusion 1110 can also play a certain limiting and positioning role for the first current collector 13, reducing the risk of electrical connection failure between the first current collector 13 and the first tab 120 and between the first current collector 13 and the wall 11a. This is beneficial to improving the reliability of the cylindrical battery cell 10, and thus to improving the reliability of the battery device 100.

[0240] According to some embodiments of this application, please refer to Figure 8 , Figure 9 or Figure 11 The first current collector 13 also includes a transition portion 132, which connects the first portion 130 and the second portion 131. The transition portion 132 is configured to deform when the first portion 130 and the second portion 131 move closer to or further away from each other along the first direction z.

[0241] In some embodiments, the transition portion 132 is a structure connecting the first portion 130 and the second portion 131. The transition portion 132 is configured to deform when the first portion 130 and the second portion 131 move closer or further apart along the first direction z. That is, when the first current collector 13 is compressed or stretched in the first direction z, the transition portion 132 can deform when the first portion 130 and the second portion 131 move closer or further apart. It should be noted that the deformation of the transition portion 132 can be either elastic or plastic.

[0242] Optionally, the first part 130, the second part 131 and the transition part 132 of the first current collector 13 can be an integrally formed structure or a separate but connected structure. For example, the first part 130, the second part 131 and the transition part 132 of the first current collector 13 are an integral structure formed by an integral forming process such as stamping and cutting.

[0243] Optionally, the transition portion 132 can be arc-shaped, and the first portion 130 and the second portion 131 are smoothly connected through the transition portion 132.

[0244] Optionally, the transition portion 132 has a multi-segment structure and may include multiple interconnected bent segments 133, so that the first portion 130 is connected to the second portion 131 through multiple interconnected bent segments 133.

[0245] In the above scheme, the first current collector 13 is also provided with a transition portion 132 connecting the first part 130 and the second part 131. By setting the transition portion 132 to be deformable when the first part 130 and the second part 131 move closer or further apart along the first direction z, the transition portion 132 can play a certain buffering role between the first part 130 and the second part 131. In this way, during the process of the electrode assembly 12 shaking or shifting, it can alleviate the rigid tension between the first part 130 and the second part 131, between the first part 130 and the first tab 120, and between the second part 131 and the first protrusion. This is beneficial to further reduce the risk of electrical connection failure between the first part 130 and the first tab 120 and between the second part 131 and the first protrusion, and also beneficial to reduce the phenomenon of the first current collector 13 being damaged by tension. This is beneficial to improving the reliability of the cylindrical battery cell 10, and thus beneficial to improving the reliability of the battery device 100.

[0246] According to some embodiments of this application, the transition portion 132 is bent to form a plurality of bent segments 133, the plurality of bent segments 133 are connected in sequence, and the bent segments 133 located at both ends of the plurality of bent segments 133 are respectively connected to the second portion 131 and the first portion 130.

[0247] The transition section 132 is bent to form multiple bent segments 133, which are connected in sequence. In other words, the transition section 132 is a structure with a local bending, so that the transition section 132 forms multiple bent segments 133 connected in sequence, and each pair of adjacent bent segments 133 is set at an acute angle, a right angle or an obtuse angle.

[0248] For example, in Figure 8 In the middle, the transition portion 132 is bent to form three bent segments 133 connected in sequence, and the two bent segments 133 at both ends of the three bent segments 133 are connected to the first part 130 and the second part 131 respectively. Of course, in other embodiments, the number of bent segments 133 formed by the bending of the transition portion 132 can also be two, four, five or six, etc.

[0249] In the above solution, by setting the transition portion 132 as a structure of bending to form a plurality of sequentially connected bent segments 133, and the bent segments 133 at both ends of the plurality of bent segments 133 being connected to the first portion 130 and the second portion 131 respectively, the deformation capacity of the transition portion 132 when the first portion 130 and the second portion 131 move closer or further away from each other along the first direction z can be increased, thereby further improving the buffering effect of the transition portion 132 between the first portion 130 and the second portion 131, and further reducing the phenomenon of rigid tension between the first portion 130 and the second portion 131, between the first portion 130 and the first tab 120, and between the second portion 131 and the first protrusion.

[0250] According to some embodiments of this application, the thickness of the transition portion 132 is less than the thickness of the second portion 131; and / or the thickness of the transition portion 132 is less than the thickness of the first portion 130.

[0251] In some embodiments, the transition portion 132, the first portion 130, and the second portion 131 are all sheet-like structures. Optionally, the thickness of the transition portion 132 may be less than the thickness of the second portion 131. Optionally, the thickness of the transition portion 132 may be less than the thickness of the first portion 130.

[0252] In the above solution, by setting the thickness of the transition portion 132 to be less than the thickness of the first portion 130, the manufacturing cost and difficulty of the first current collector 13 are reduced, while the ability of the transition portion 132 to deform when the first portion 130 and the second portion 131 move closer or further apart along the first direction z is improved, thus enabling the transition portion 132 to play a better buffering role between the first portion 130 and the second portion 131. Similarly, by setting the thickness of the transition portion 132 to be less than the thickness of the second portion 131, the manufacturing cost and difficulty of the first current collector 13 are reduced, while the ability of the transition portion 132 to deform when the first portion 130 and the second portion 131 move closer or further apart along the first direction z is improved, thus enabling the first portion 130 and the second portion 131 to play a better buffering role.

[0253] According to some embodiments of this application, the first protrusion 1110 is an annular structure extending circumferentially along the sidewall 111.

[0254] In some embodiments, the first protrusion 1110 extends circumferentially around the sidewall 111 so that the projection of the first protrusion 1110 is annular on a projection plane perpendicular to the first direction z.

[0255] Optionally, the weld mark 16 formed by welding the second part 131 to the first protrusion 1110 can be an annular structure extending circumferentially along the sidewall 111.

[0256] Optionally, there may be multiple solder marks 16, which are arranged at circumferential intervals along the sidewall 111.

[0257] Optionally, the first part 130 may be in the shape of a disk, and there may be multiple second parts 131. The multiple second parts 131 are arranged at intervals along the circumference of the first part 130, and each second part 131 is connected to the first part 130 through a transition part 132.

[0258] In the above solution, by setting the first protrusion 1110 as an annular structure extending circumferentially along the sidewall 111, on the one hand, the limiting or positioning effect of the first protrusion 1110 on the electrode assembly 12 and the end cap 113 can be further improved; on the other hand, the first protrusion 1110 can be welded to the second part 131 of the first current collector 13 at any position in the circumferential direction of the sidewall 111. This facilitates the welding connection between the second part 131 of the first current collector 13 and the first protrusion 1110, so that after the first current collector 13 is assembled into the housing 110, the welding assembly of the second part 131 and the first protrusion 1110 can be achieved without rotating and adjusting the position of the first current collector 13. This helps to further reduce the welding difficulty between the second part 131 of the first current collector 13 and the first protrusion 1110, thereby effectively improving the assembly efficiency of the cylindrical battery cell 10.

[0259] According to some embodiments of this application, a first groove 1111 is formed on the side of the sidewall 111 away from the receiving cavity 114 and corresponding to the position of the first protrusion 1110.

[0260] For example, the first protrusion 1110 formed on the side of the sidewall 111 facing the receiving cavity 114 is a structure formed by a stamping process, so that the first protrusion 1110 is formed on the side of the sidewall 111 facing the receiving cavity 114, and a first groove 1111 is formed on the side of the sidewall 111 away from the receiving cavity 114 and at the position corresponding to the first protrusion 1110.

[0261] For example, the first protrusion 1110 formed on the side of the sidewall 111 facing the receiving cavity 114 is a structure formed by a roll forming process, so that the first protrusion 1110 is formed on the side of the sidewall 111 facing the receiving cavity 114, and a first groove 1111 is formed on the side of the sidewall 111 away from the receiving cavity 114 and at the position corresponding to the first protrusion 1110.

[0262] Of course, the forming method of the first protrusion 1110 formed on the side of the sidewall 111 facing the receiving cavity 114 is not limited to this. In other embodiments, the first protrusion 1110 formed on the side of the sidewall 111 facing the receiving cavity 114 can also be formed by a processing process such as casting.

[0263] It should be noted that in the embodiment where the first protrusion 1110 is an annular structure extending circumferentially along the sidewall 111, the first groove 1111 is also an annular groove structure extending circumferentially along the sidewall 111.

[0264] In the above solution, by forming a first groove 1111 on the side of the sidewall 111 facing away from the receiving cavity 114 and corresponding to the first protrusion 1110, the first protrusion 1110 formed on the side of the sidewall 111 facing the receiving cavity 114 can be formed by stamping. This allows the first protrusion 1110 to be formed on the side of the sidewall 111 facing the receiving cavity 114, and the first groove 1111 to be formed on the other side corresponding to the first protrusion 1110. This structure of the cylindrical battery cell 10 reduces the difficulty of forming the first protrusion 1110 on the sidewall 111 facing the receiving cavity 114, thus improving the performance of the cylindrical battery cell. On the one hand, it improves the production efficiency of body 10, and on the other hand, it enables the first protrusion 1110 to have a hollow internal structure, thereby reducing the power required for welding the first protrusion 1110 and the second part 131 of the first current collector 13 to each other. This helps to reduce the welding difficulty between the first protrusion 1110 and the second part 131 of the first current collector 13, and also enables the first protrusion 1110 to have the ability to deform elastically, which helps to further alleviate the rigid tension between the second part 131 of the first current collector 13 and the first protrusion 1110, thereby reducing the risk of weld detachment between the second part 131 of the first current collector 13 and the first protrusion 1110.

[0265] According to some embodiments of this application, a protective layer 17 is provided on the side of the sidewall 111 facing away from the receiving cavity 114 and corresponding to the position of the first protrusion 1110.

[0266] In some embodiments, the provision of a protective layer 17 on the side of the sidewall 111 away from the receiving cavity 114 and corresponding to the position of the first protrusion 1110 can be understood as the provision of a protective layer 17 on the outer surface of the sidewall 111, and the protective layer 17 can be provided at least on the groove wall surface of the first groove 1111.

[0267] In the above solution, a protective layer 17 is provided on the side of the sidewall 111 away from the receiving cavity 114 and at the position corresponding to the first protrusion 1110. This protective layer 17 can cover the part of the sidewall 111 that is worn or cracked due to the first groove 1111 formed by stamping, thus isolating the outside world from the worn or cracked part, thereby effectively reducing the risk of corrosion of the sidewall 111, thereby effectively improving the reliability of the cylindrical battery cell 10, and further effectively improving the reliability of the battery device 100.

[0268] According to some embodiments of this application, the inner peripheral surface of the second protrusion 1112 is provided with an opening 115, and a protective layer 17 is provided on the inner peripheral surface of the second protrusion 1112.

[0269] In some embodiments, the inner peripheral surface of the second protrusion 1112 surrounds an opening 115 forming a sidewall 111 along a first direction z, and the end cap 113 closes the opening 115.

[0270] Optionally, the second protrusion 1112 and the sidewall 111 are integrally formed. Exemplarily, the second protrusion 1112 is a flanged structure in which the sidewall 111 is partially folded inwards. The folding action causes the end of the sidewall 111 to bend inwards to form the second protrusion 1112. In some embodiments, when the end cap 113 is placed on the sidewall 111, the opening 115 side of the sidewall 111 is sealed, causing the end wall of the sidewall 111 to bend inwards to form a flanged structure, thereby constituting the second protrusion 1112.

[0271] In some embodiments, the inner peripheral surface of the second protrusion 1112 can be understood as the cross-section of the second protrusion 1112. Taking the second protrusion 1112 and the sidewall 111 as an integrally formed structure as an example, the cross-section directly exposes the substrate of the sidewall 111, which is prone to becoming a rust starting point. The provision of a protective layer 17 on the inner peripheral surface of the second protrusion 1112 can be understood as the provision of a protective layer 17 on the outer surface of the sidewall 111, and a portion of the protective layer 17 is located on the inner peripheral surface of the second protrusion 1112, that is, on the cross-section of the second protrusion 1112.

[0272] Optionally, the protective layer 17 may cover the inner peripheral surface of the second protrusion 1112.

[0273] In the above scheme, the inner peripheral surface of the second protrusion 1112 forms an opening 115, and the inner peripheral surface of the second protrusion 1112 has a cross-sectional structure. In this regard, by providing a protective layer 17 on the inner peripheral surface of the second protrusion 1112, the inner peripheral surface of the second protrusion 1112 can be isolated from the outside, thereby reducing the risk that the inner peripheral surface of the second protrusion 1112 will become the corrosion starting point of the sidewall 111, so that the cylindrical battery cell 10 has high reliability, and thus the battery device 100 has high reliability.

[0274] According to some embodiments of this application, the inner peripheral surface of the second protrusion 1112 forms an opening 115. The battery cell also includes a seal 19, which includes a first connecting portion 190 and a second connecting portion 191 connected to each other. Along a first direction z, the first connecting portion 190 is disposed between the end cap 113 and the second protrusion 1112, and the second connecting portion 191 covers the inner peripheral surface of the second protrusion 1112. Along the first direction z, the second protrusion 1112 has a first surface 1113 facing away from the electrode assembly 12, and the second connecting portion 191 has a second surface 192 facing away from the electrode assembly 12. A protective layer 17 is provided on both the first surface 1113 and the second surface 192.

[0275] The seal 19 is a structural component that enables a sealing fit between the end cap 113 and the second protrusion 1112. Optionally, the seal 19 can be made of plastic or rubber.

[0276] According to other embodiments of this application, please refer to Figure 12 , Figure 12 This is a schematic diagram of a partial structure of the outer casing 11, the first current-collecting member 13, the seal 19, and the protective layer 17 in other embodiments of this application. The seal 19 includes a first connecting portion 190 and a second connecting portion 191 connected to each other. The first connecting portion 190 is disposed between the end cap 113 and the second protrusion 1112, and the second connecting portion 191 covers the inner peripheral surface of the second protrusion 1112, that is, covers the cross-section of the second protrusion 1112. Optionally, the seal 19 also includes a third portion connected to the first connecting portion 190, and the third portion is located between the first protrusion 1110 and the end cap 113.

[0277] The first surface 1113 is the surface of the second protrusion 1112 exposed to the outside along the first direction z, and the second surface 192 is the surface of the second connecting portion 191 exposed to the outside along the first direction z.

[0278] In some embodiments, the protective layer 17 is disposed on the outer side of the sidewall 111, and a portion of the protective layer 17 is also disposed on the first surface 1113 and the second surface 192.

[0279] For example, the protective layer 17 covers the first surface 1113 and extends to a portion or the entire second surface 192.

[0280] In the above solution, a sealing element 19 is provided between the end cap 113 and the second protrusion 1112, which can improve the sealing level between the end cap 113 and the side wall 111, reduce the risk of leakage of internal materials or entry of external materials into the cylindrical battery cell 10, and make the cylindrical battery cell 10 have high reliability. At the same time, by providing a protective layer 17 on both the first surface 1113 and the second surface 192, the risk of external materials contacting the inner circumferential surface of the second protrusion 1112 and causing the casing 110 to be corroded can be effectively reduced, thereby improving the reliability of the cylindrical battery cell 10 and thus improving the reliability of the battery device 100.

[0281] According to some embodiments of this application, the seal 19 insulates the sealing end cap 113 and the housing 110.

[0282] Alternatively, the seal 19 may be made of an insulating material, such as plastic.

[0283] In the above solution, the seal 19 serves two purposes: firstly, it acts as a seal to reduce the risk of external substances entering the cylindrical battery cell 10; secondly, it acts as an insulator to reduce the risk of short circuit inside the cylindrical battery cell 10 caused by the overlap of the end cap 113 and the housing 110, thus making the battery cell highly reliable.

[0284] According to some embodiments of this application, please refer to Figure 8 , Figure 9 , Figure 11 or Figure 12 The sidewall 111 includes a first sub-wall 116 and a second sub-wall 117 arranged along a first direction z. A first protrusion 1110 is located between the first sub-wall 116 and the second sub-wall 117 along the first direction z. The first sub-wall 116 is connected to the first protrusion 1110 via a first transition section 1160. The first protrusion 1110 is connected to the second sub-wall 117 via a second transition section 1161. The second sub-wall 117 is connected to the second protrusion 1112 via a third transition section 1170. A protective layer 17 is provided on the outer surfaces of the first transition section 1160, the second transition section 1161, and the third transition section 1170.

[0285] The first sub-wall 116 is a partial structure of the sidewall 111, and the second sub-wall 117 is a partial structure of the sidewall 111. Along the first direction z, the first protrusion 1110 is located between the first sub-wall 116 and the second sub-wall 117, and the second protrusion 1112 is located on the side of the second sub-wall 117 opposite to the first sub-wall 116. The first transition section 1160 is a structure that transitions between the first sub-wall 116 and the first protrusion 1110; the first transition section 1160 may be arc-shaped to allow a smooth transition between the first sub-wall 116 and the first protrusion 1110. The second transition section 1161 is a structure that transitions between the first protrusion 1110 and the second sub-wall 117; the second transition section 1161 may be arc-shaped to allow a smooth transition between the first protrusion 1110 and the second sub-wall 117.

[0286] For example, taking the first protrusion 1110 as a roller groove structure, the first transition section 1160 and the second transition section 1161 can be the areas where the sidewall 111 undergoes plastic deformation or stretching during the rolling process.

[0287] The third transition section 1170 is a structure that transitions between the second sub-wall 117 and the second protrusion 1112. The third transition section 1170 may be arc-shaped to allow a smooth transition between the second sub-wall 117 and the second protrusion 1112. For example, the second protrusion 1112 is a flanged structure, and the third transition section 1170 may refer to the area where the sidewall 111 undergoes plastic deformation or stretching during the sealing process.

[0288] Plastic deformation or stretching can cause metal lattice distortion, which increases the surface roughness of the sidewall 111, making it easier to absorb moisture and oxygen, accelerating corrosion. In addition, there is a risk of stress concentration and microcrack formation in the deformed area. To address this, a protective layer 17 can be provided on the surfaces of the first transition section 1160, the second transition section 1161, and the third transition section 1170.

[0289] Optionally, in some embodiments, the protective layer 17 may cover the outer surface of the first transition section 1160, the outer side of the first protrusion 1110, the outer surface of the second transition section 1161, the outer surface of the third transition section 1170, and the portion at the junction of the first surface 1113 and the second surface 192.

[0290] In the above scheme, the sidewall 111 undergoes local plastic deformation to form a transition section, which allows for a smooth transition between the first sub-wall 116, the first protrusion 1110, the second sub-wall 117, and the second protrusion 1112. This reduces the risk of cracking of the sidewall 111 due to stress concentration, which is beneficial to improving the structural reliability of the cylindrical battery cell 10, and thus to improving the reliability of the battery device 100. At the same time, a protective layer 17 is provided on the outer surface of the transition section, which isolates the transition section from the outside world. This effectively reduces the risk of microcracks caused by local plastic deformation of the sidewall 111, which could lead to corrosion of the sidewall 111. This results in higher reliability for the cylindrical battery cell 10, and thus higher reliability for the battery device 100.

[0291] According to some embodiments of this application, the protective layer 17 includes a rust-preventive oil coating or a UV-curable layer.

[0292] In some embodiments, the protective layer 17 is made of rust-preventive oil. Rust-preventive oil primarily prevents the wall portion 11a from rusting by forming a protective film on the metal surface to isolate moisture and other corrosive substances in the air. Its components include, but are not limited to, a certain proportion of hydrogenated light petroleum fractions, rust inhibitors, film-forming agents, antioxidants, etc. Exemplarily, the rust-preventive oil is applied starting from a portion of the first sub-wall 116 adjacent to the first protrusion 1110 and ending at the junction of the second protrusion 1112 and the second portion 131 of the seal 19.

[0293] In some embodiments, the protective layer 17 is made of a UV-curable material, meaning that the protective layer 17 can be rapidly cured by ultraviolet (UV) light initiating a photoinitiator reaction in the coating to form a solid protective layer 17. The UV-curable material may include UV resin, photoinitiator, and additives. Exemplarily, a portion of the first sub-wall 116 adjacent to the first protrusion 1110 is used as the starting point for coating, and the junction of the second protrusion 1112 and the second portion 131 of the seal 19 is used as the ending point for coating. UV liquid material is applied to form a liquid coating on the surface of the corresponding area, followed by a UV curing process and cooling to form the protective layer 17.

[0294] In the above scheme, by setting the protective layer 17 to include an anti-rust oil coating or an ultraviolet curing layer, a variety of material options can be provided for the protective layer 17 to meet different usage requirements and facilitate diversified selection of battery cell application scenarios.

[0295] According to some embodiments of this application, the protective layer 17 includes an ultraviolet light fixing layer, the Vickers hardness of which is greater than or equal to 150.

[0296] The protective layer 17 can be a UV-curable coating with a Vickers hardness greater than or equal to 150. For example, the Vickers hardness of the UV-curable coating can be 150, 151HV, 152, 153...160 or a larger value.

[0297] Optionally, the Vickers hardness of the protective layer 17 can be measured using a Vickers hardness tester.

[0298] In the above scheme, by setting the Vickers hardness of the protective layer 17 to be greater than or equal to 150HV, it can effectively prevent rust and resist mechanical wear, thereby making the battery cell structure highly reliable and thus making the battery device 100 highly reliable.

[0299] Some embodiments of this application provide a battery device 100, including the cylindrical battery cell 10 described above.

[0300] See Figure 2 As shown, the battery device 100 may further include a housing 20, in which the cylindrical battery cell 10 is housed. In some embodiments, the housing 20 may include a first housing body 21 and a second housing body 22, which cover each other and together define an assembly space for accommodating the battery cell.

[0301] Optionally, there may be multiple cylindrical battery cells 10 disposed within the housing 20. For example, in... Figure 2 In the battery device 100, a plurality of cylindrical battery cells 10 are arranged inside the housing 20. The plurality of cylindrical battery cells 10 are connected in series, in parallel, or in a mixed manner. A mixed manner means that the plurality of cylindrical battery cells 10 are connected in both series and parallel. The plurality of cylindrical battery cells 10 can be directly connected in series, in parallel, or in a mixed manner together, and then the whole assembly of the plurality of cylindrical battery cells 10 is housed in the housing 20.

[0302] It should be noted that in some embodiments, the battery device 100 may not have a housing 20. The battery device 100 includes multiple cylindrical battery cells 10, and the battery device 100, composed of multiple cylindrical battery cells 10 electrically connected together, can be directly mounted onto the electrical device to provide power to the electrical device through the multiple cylindrical battery cells 10. That is, the housing 20 can be part of the electrical device. Taking a vehicle 1000 as an example, the housing 20 can be part of the chassis structure of the vehicle 1000. For example, a portion of the housing 20 can be at least a part of the floor of the vehicle 1000, or a portion of the housing 20 can be at least a part of the crossbeams and longitudinal beams of the vehicle 1000.

[0303] Some embodiments of this application provide an electrical device, which includes the cylindrical battery cell 10 and / or battery device 100 provided above.

[0304] The electrical device can be any of the aforementioned applications of cylindrical battery cells 10 and / or battery devices 100, either as described above. For example, the electrical device can be a vehicle 1000, which can be a range-extended, pure electric, or gasoline-powered vehicle. The electrical energy provided by the cylindrical battery cells 10 can be used to meet the power needs of the vehicle 1000 during startup, navigation, and operation.

[0305] Some embodiments of this application provide a cylindrical battery cell 10; please refer to [link to relevant documentation]. Figures 3-12 .

[0306] The cylindrical battery cell 10 includes a casing 11, an electrode assembly 12, a first current collector 13, an electrode terminal 15, and a second current collector 14.

[0307] Taking the axial direction of the cylindrical battery cell 10 as the first direction z as an example.

[0308] The outer casing 11 includes a housing 110 and an end cap 113. The housing 110 includes an integrally formed side wall 111 and a bottom wall 112. The side wall 111 surrounds the bottom wall 112. Along the first direction z, one end of the side wall 111 is connected to the bottom wall 112, and the other end forms an opening 115. The side wall 111 and the bottom wall 112 together define a receiving cavity 114, in which the electrode assembly 12 is received.

[0309] A first protrusion 1110 is provided on the side of the sidewall 111 facing the cavity 114, and a second protrusion 1112 is provided at the end of the sidewall 111 away from the bottom wall 112 in the first direction z. Along the first direction z, the electrode assembly 12 is located on the side of the first protrusion 1110 away from the second protrusion 1112. The end cap 113 is sealed between the first protrusion 1110 and the second protrusion 1112 by a sealing member 19 to close the opening 115.

[0310] The sidewall 111 is partially deformed and recessed to form a first protrusion 1110. Corresponding to the position of the first protrusion 1110, a first groove 1111 is formed on the side of the sidewall 111 facing away from the receiving cavity 114. The sidewall 111 is partially deformed and bent inward to form a second protrusion 1112, which is a flanged structure. When the sidewall 111 is partially deformed, the sidewall 111 includes a first sub-wall 116, a first transition section 1160, a first protrusion 1110, a second transition section 1161, a second sub-wall 117, a third transition section 1170, and a second protrusion 1112 along the first direction z.

[0311] The first current collector 13 includes a first part 130, a transition part 132, and a second part 131. The first part 130 and the second part 131 are connected by the transition part 132. The first part 130 is welded to the first tab 120 of the electrode assembly 12. The second part 131 is welded to the side of the first protrusion 1110 facing the end cap 113 to form a solder mark 16.

[0312] The electrode terminal 15 is insulated on the bottom wall 112 and is connected to the second tab 121 of the electrode assembly 12 through the second current collector 14.

[0313] The sidewall 111 is made of steel, and the outer surface of the sidewall 111 is provided with a plating layer 18, which can be a nickel plating layer.

[0314] The outer side of the sidewall 111 is also provided with a protective layer 17, which covers at least the outer side of the first transition section 1160, the groove wall of the first groove 1111, the outer side of the second transition section 1161, the outer side of the second sub-wall 117, the outer side of the third transition section 1170, the outer side of the second protrusion 1112, and the outer side of the seal 19.

[0315] The protective layer 17 can be a rust-preventive oil coating or a UV-cured layer.

[0316] In the above scheme, the protective layer 17 covers the sidewall 111 corresponding to the location of the solder mark 16, and covers the part of the sidewall 111 that is locally deformed. It can protect the area where the metal structure changes due to high temperature during the welding process of the first current collector 13 and the wall 11a, and the area where the sidewall 111 cracks due to local deformation. This reduces the leakage of internal materials of the battery cell from this area, or reduces the risk of the connection between the first current collector 13 and the wall 11a failing due to corrosion of the wall 11a, causing the first current collector 13 and the wall 11a to separate from each other. This is beneficial to improving the reliability of the cylindrical battery cell 10, and thus to improving the reliability of the battery device 100.

[0317] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A cylindrical battery cell, characterized in that, include: The outer shell has walls; An electrode assembly is disposed within the housing, the electrode assembly having a first tab; A first current collector is located inside the housing, and the first electrode tab is electrically connected to the wall through the first current collector; The first current collector includes a first part and a second part that are connected to each other. The first part is electrically connected to the first electrode tab, and the second part is welded to the wall to form a solder mark. A protective layer is provided on the outer side of the wall corresponding to the position of the solder mark.

2. The cylindrical battery cell according to claim 1, characterized in that, The outer surface of the wall portion is provided with a coating, and at least a portion of the coating is located between the protective layer and the outer surface of the wall portion.

3. The cylindrical battery cell according to claim 2, characterized in that, The outer shell is a steel shell, and the plating is a nickel plating layer.

4. The cylindrical battery cell according to claim 1, characterized in that, The second part and the wall portion are stacked together; One end of the solder mark protrudes from the side of the second portion away from the wall portion, and the other end of the solder mark is embedded in the wall portion and does not protrude from the side of the wall portion away from the second portion, or One end of the solder mark protrudes from the side of the wall portion away from the second part, and the other end of the solder mark is embedded in the second part and does not protrude from the side of the second part away from the wall portion.

5. The cylindrical battery cell according to claim 1, characterized in that, The second part and the wall part are stacked together, one end of the solder stamp protrudes from the second part on the side away from the wall part, and the other end of the solder stamp protrudes from the wall part on the side away from the second part.

6. The cylindrical battery cell according to any one of claims 1-5, characterized in that, The outer casing includes: The housing includes an integrally formed sidewall and a bottom wall. The sidewall surrounds the bottom wall. Along a first direction, one end of the sidewall is connected to the bottom wall, and the other end forms an opening. The sidewall and the bottom wall together define a receiving cavity, and the electrode assembly is received in the receiving cavity. The first direction is the axial direction of the housing. End cap, to close the opening; The wall portion refers to either the side wall or the bottom wall.

7. The cylindrical battery cell according to claim 6, characterized in that, The wall portion is the sidewall; A first protrusion is provided on the side of the sidewall facing the receiving cavity, and a second protrusion is provided at the end of the sidewall away from the bottom wall in the first direction. Along the first direction, at least a portion of the electrode assembly is located on the side of the first protrusion away from the second protrusion, and the end cap is located between the first protrusion and the second protrusion.

8. The cylindrical battery cell according to claim 7, characterized in that, The second part is welded to the first protrusion to form the weld mark.

9. The cylindrical battery cell according to claim 8, characterized in that, Along the first direction, the second portion is welded to the side of the first protrusion facing the end cap to form the solder mark portion.

10. The cylindrical battery cell according to claim 8, characterized in that, Along the first direction, the second portion is welded to the side of the first protrusion opposite to the end cap to form the solder mark portion.

11. The cylindrical battery cell according to claim 8, characterized in that, The first current collector further includes a transition portion connecting the first portion and the second portion, the transition portion being configured to deform when the first portion and the second portion move closer to or further away from each other along the first direction.

12. The cylindrical battery cell according to claim 11, characterized in that, The transition portion is bent to form multiple bent segments, which are connected sequentially, and the bent segments at both ends of the multiple bent segments are respectively connected to the second part and the first part.

13. The cylindrical battery cell according to claim 11, characterized in that, The thickness of the transition portion is less than the thickness of the second portion; and / or The thickness of the transition portion is less than the thickness of the first portion.

14. The cylindrical battery cell according to claim 7, characterized in that, The first protrusion is a ring structure that extends circumferentially along the sidewall.

15. The cylindrical battery cell according to claim 7, characterized in that, The sidewall is opposite to the receiving cavity and has a first groove formed at the position corresponding to the first protrusion.

16. The cylindrical battery cell according to claim 15, characterized in that, The protective layer is provided on the side of the sidewall that is away from the receiving cavity and at the position corresponding to the first protrusion.

17. The cylindrical battery cell according to claim 7, characterized in that, The opening is formed by the inner peripheral surface of the second protrusion, and the protective layer is provided on the inner peripheral surface of the second protrusion.

18. The cylindrical battery cell according to claim 7, characterized in that, The opening is formed by the inner peripheral surface of the second protrusion. The battery cell also includes a sealing element, which includes a first connecting portion and a second connecting portion connected to each other. Along the first direction, the first connecting portion is disposed between the end cap and the second protrusion, and the second connecting portion covers the inner peripheral surface of the second protrusion. Along the first direction, the second protrusion has a first surface facing away from the electrode assembly, and the second connecting portion has a second surface facing away from the electrode assembly. The protective layer is provided on both the first surface and the second surface.

19. The cylindrical battery cell according to claim 18, characterized in that, The seal provides an insulating seal to the end cap and the housing.

20. The cylindrical battery cell according to claim 7, characterized in that, The sidewall includes a first subwall and a second subwall arranged along the first direction. Along the first direction, the first protrusion is located between the first subwall and the second subwall. The first subwall is connected to the first protrusion through a first transition section. The first protrusion is connected to the second subwall through a second transition section. The second subwall is connected to the second protrusion through a third transition section. The protective layer is provided on the outer surface of the first transition section, the outer surface of the second transition section, and the outer surface of the third transition section.

21. The cylindrical battery cell according to claim 1, characterized in that, The protective layer includes an anti-rust oil coating or a UV-cured layer.

22. The cylindrical battery cell according to claim 21, characterized in that, The protective layer includes an ultraviolet light fixing layer, wherein the Vickers hardness of the ultraviolet light fixing layer is greater than or equal to 150.

23. A battery device, characterized in that, Includes the cylindrical battery cell according to any one of claims 1-22.

24. An electrical appliance, characterized in that, Includes the cylindrical battery cell according to any one of claims 1-22, and / or the battery device according to claim 23.

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