Battery cell, battery device, and electric device

Abstract

The application relates to a battery monomer, a battery device and an electric equipment. The battery monomer comprises a shell, an electrode assembly and a cover assembly. The shell has an opening. The electrode assembly is arranged in the shell and comprises an electrode main body and a connecting part connected to the electrode main body. The cover assembly comprises a cover, an insulating part and an electrode terminal. The cover covers the opening. The insulating part is arranged on the side of the cover facing the electrode assembly. The electrode terminal is arranged on the cover. The connecting part is welded to the electrode terminal. The insulating part comprises an insulating main body and a positioning structure arranged on the insulating main body. At least part of the connecting part is located on the side of the insulating main body away from the cover. In the same plane perpendicular to the thickness direction of the cover, at least part of the orthographic projection of the connecting part does not overlap with the orthographic projection of the positioning structure. The battery monomer provided by the application takes the positioning structure as the positioning reference of the welding of the connecting part and the electrode terminal to assist in identifying the positioning.

Description

Technical Field

[0001] This application relates to the field of battery manufacturing technology, and in particular to battery cells, battery devices and electrical equipment. Background Technology

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools. Battery cells can include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and rechargeable alkaline zinc-manganese batteries, among others.

[0003] In the development of batteries, how to ensure the reliability of individual battery cells is a technical problem that urgently needs to be solved. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical appliance, which aims to improve the reliability of the battery cell to a certain extent.

[0005] In a first aspect, this application proposes a battery cell, which includes a housing, an electrode assembly, and an end cap assembly. The housing has an opening. The electrode assembly is disposed within the housing and includes an electrode body and a connecting portion connected to the electrode body. The end cap assembly includes an end cap, an insulating member, and electrode terminals. The end cap closes to the opening, the insulating member is disposed on the side of the end cap facing the electrode assembly, the electrode terminals are disposed on the end cap, and the connecting portion is welded to the electrode terminals. The insulating member includes an insulating body and a positioning structure disposed on the insulating body. At least a portion of the connecting portion is located on the side of the insulating body opposite to the end cap, and in the same plane perpendicular to the thickness direction of the end cap, at least a portion of the orthographic projection of the connecting portion does not overlap with the orthographic projection of the positioning structure.

[0006] The battery cell provided in this application solves the problem of difficult-to-locate the weld center by incorporating a positioning structure in the insulating body. During the welding process between the connecting part and the electrode terminals, the positioning structure is not obstructed and serves as a positioning reference for welding the connecting part to the electrode terminals, aiding in identification and positioning. Furthermore, the positioning structure makes the weld formation position more accurate, thereby improving welding quality, mitigating weld defects caused by deviations, and enhancing the reliability of the battery cell. The positioning structure is integrated into the insulating body, requiring minimal modification to the overall structure of the end cap assembly, ensuring good compatibility with existing manufacturing processes, and reducing the manufacturing cost of the battery cell.

[0007] According to one embodiment of this application, the positioning structure is recessed inward relative to the surface of the insulating body facing the electrode assembly. This inward recess of the insulating body surface forms the positioning structure, simplifying its formation and making it easier to manufacture.

[0008] According to one embodiment of this application, the positioning structure protrudes from the surface of the insulating body facing the electrode assembly. The positioning structure protrudes from the surface of the insulating body, forming a significant three-dimensional height difference with the insulating body, making it easier to identify as a positioning reference for welding.

[0009] According to one embodiment of this application, a positioning structure is disposed on the side of the electrode terminal facing the connection portion along the length direction of the end cap, and is spaced apart from the electrode terminal. This spacing between the positioning structure and the electrode terminal makes the positioning reference easily identifiable and reduces interference from the electrode terminal. Heat is generated during welding of the electrode terminal to the connection portion; by maintaining a certain distance between the positioning reference and the electrode terminal, the impact of heat on the positioning structure can be reduced, minimizing structural damage caused by heat.

[0010] According to one embodiment of this application, the distance L between the positioning structure and the electrode terminal in the length direction is less than or equal to 60 mm. The appropriate spacing between the positioning structure and the electrode terminal ensures that the positioning structure is within the CCD recognition range and also reduces the impact of heat on the positioning structure.

[0011] According to one embodiment of this application, the connection part includes a tab and a current collector, the tab is connected to the electrode body and the current collector, and the current collector is welded to the electrode terminal.

[0012] According to one embodiment of this application, the current collector has a through groove. In the thickness direction of the end cap, the through groove is positioned opposite to the positioning structure, and the through groove is used to expose the positioning structure. Within the confined space inside the battery cell, the positioning structure can be quickly identified, reducing the current collector's obstruction of the positioning structure.

[0013] According to one embodiment of this application, a through groove is disposed at the end of the current collector member away from the electrode terminal along the length direction of the end cap. The through groove's location at the end of the current collector member away from the terminal reduces the impact on the welding between the current collector member and the electrode terminal, resulting in a suitable area for the solder joint formed between the current collector member and the electrode terminal, thereby ensuring high connection stability.

[0014] According to one embodiment of this application, the positioning structure protrudes from the surface of the insulating body facing the electrode assembly, and the positioning structure engages with the through slot. The engagement of the positioning structure and the through slot provides a limiting effect on the current collector, restricting its displacement after installation and improving the assembly stability of the current collector.

[0015] According to one embodiment of this application, the current collector includes a first welding area and a second welding area. The second welding area is disposed at one end of the current collector away from the first welding area along its length. The first welding area is used to connect to an electrode terminal, and the second welding area is used to connect to a tab. The second welding area is located on at least one side of the through slot along the width direction of the end cap. By disposing the through slot at the end of the current collector and not in the main conductive area in the middle of the current collector, the impact on current transmission is reduced.

[0016] According to one embodiment of this application, the second welding area is located on opposite sides of the through groove along its width. The presence of a second welding area on both sides of the through groove mitigates the problem of stress concentration caused by welding.

[0017] According to one embodiment of this application, the battery cell includes two electrode terminals and two connecting portions; the insulating member includes two positioning structures, with the two electrode terminals located between the two positioning structures along the length of the end cap.

[0018] According to one embodiment of this application, the length of the battery cell is 220mm to 400mm. A positioning structure is provided in the insulating body to assist the CCD image acquisition unit in precise positioning, which is suitable for longer battery cells, improves welding quality, reduces solder joint defects caused by deviation, and improves the reliability of the battery cell.

[0019] Secondly, this application provides a battery device, which includes the battery cell according to the foregoing.

[0020] Thirdly, this application provides an electrical device that includes a battery cell or a battery device as described above, wherein the battery cell or battery device is used to store or provide electrical energy.

[0021] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0022] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the structure of a vehicle provided in one embodiment of this application;

[0024] Figure 2 This is an exploded view of a battery device provided in an embodiment of this application;

[0025] Figure 3 This is an exploded view of a single battery cell provided in an embodiment of this application;

[0026] Figure 4 This is a partial structural schematic diagram of the end cap assembly and electrode assembly of a battery cell provided in an embodiment of this application;

[0027] Figure 5 This is a partial structural schematic diagram of the end cap assembly and electrode assembly of a battery cell provided in another embodiment of this application;

[0028] Figure 6 This is a partial bottom view of the end cap assembly and electrode assembly of a battery cell provided in an embodiment of this application;

[0029] Figure 7 This is a partial bottom view of the end cap assembly and electrode assembly of a battery cell provided in another embodiment of this application;

[0030] Figure 8 yes Figure 7 Cross-sectional view at point AA;

[0031] Figure 9 yes Figure 7 Cross-sectional view at BB.

[0032] The accompanying drawings may not be drawn to scale.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1000, Vehicle; 100, Battery unit; 200, Controller; 300, Motor;

[0035] 1a. Battery module; 1b. First housing; 1c. Second housing; 10. Individual battery cell;

[0036] 1. Housing; 11. Opening; 2. Electrode assembly; 21. Electrode body; 22. Connecting part; 221. Electrode tab; 222. Current collector; 2221. Through groove; 2222. First welding area; 2223. Second welding area; 3. End cap assembly; 31. End cap; 32. Insulating component; 321. Insulating body; 322. Positioning structure; 33. Electrode terminal; x. Length direction; y. Width direction; z. Thickness direction. Detailed Implementation

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0042] 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.

[0043] In this application, "multiple" means two or more (including two).

[0044] Currently, judging from market trends, the application of batteries is becoming increasingly widespread. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace, among other fields.

[0045] A battery device typically refers to a single physical module comprising multiple battery cells to provide higher voltage and capacity. A battery cell can be the smallest unit that makes up a battery device.

[0046] In the manufacturing process of battery cells, the positioning accuracy during electrode terminal welding affects the welding quality and production efficiency. In related technologies, the protrusions at both ends of the insulating component in the end cap assembly are used as positioning references, and positioning is achieved through an image acquisition unit. However, due to the limited space for electrode assembly arrangement within the battery cell and the constraint of the center distance between the electrode terminals, the distance between the protrusions and the welding position is relatively long, affecting the positioning accuracy of the image acquisition unit and easily leading to defects such as weld misalignment and incomplete welding, thereby affecting the electrical performance output and reliability of the battery cell. The above statements are only used to provide background information related to this application and do not necessarily constitute prior art.

[0047] The battery cell provided in this application solves the problem of difficult-to-locate the weld center by incorporating a positioning structure in the insulating body. During the welding process between the connecting part and the electrode terminals, the positioning structure is not obstructed and serves as a positioning reference for welding the connecting part to the electrode terminals, aiding in identification and positioning. Furthermore, the positioning structure makes the weld formation position more accurate, thereby improving welding quality, mitigating weld defects caused by deviations, and enhancing the reliability of the battery cell. The positioning structure is integrated into the insulating body, requiring minimal modification to the overall structure of the end cap assembly, ensuring good compatibility with existing manufacturing processes, and reducing the manufacturing cost of the battery cell.

[0048] The battery cell described in this application is applicable to batteries and electrical devices that use batteries. This battery cell can be used, but is not limited to, batteries, and can also be used in products such as vehicles, aircraft, ships, electronic devices, and power tools, thereby improving the reliability of these products.

[0049] Electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. 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.

[0050] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device according to an embodiment of this application.

[0051] See Figure 1 As shown, one embodiment of this application provides a vehicle 1000. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. In one embodiment of this application, the vehicle 1000 may include a motor 300, a controller 200, and a battery device 100. The controller 200 is used to control the battery device 100 to supply power to the motor 300. The motor 300 is connected to the wheels via a transmission mechanism, thereby driving the vehicle 1000. The battery device 100 can serve as the driving power source for the vehicle 1000, replacing or partially replacing gasoline or natural gas to provide driving power to the vehicle 1000. In one example, the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to supply power to the vehicle 1000. In one example, the battery device 100 can serve as the operating power source for the vehicle 1000's electrical system. For example, the battery device 100 can be used to meet the power needs of the vehicle 1000 during startup, navigation and operation.

[0052] Please refer to Figure 2 , Figure 2 An exploded view of a battery device 100 provided in some embodiments of this application.

[0053] In some embodiments, the battery device 100 may include one or more battery cell assemblies for providing voltage and capacity.

[0054] A battery cell assembly may include multiple battery cells ( Figure 2 (Not shown), multiple battery cells are connected in series, parallel, or mixed connection through a busbar. Mixed connection refers to multiple battery cells being connected in both series and parallel.

[0055] A battery cell can be a rechargeable battery cell, which refers to a battery cell that can be recharged after being discharged to activate the active materials and continue to be used.

[0056] As an example, a single battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc.

[0057] As an example, a battery cell can be a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0058] 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 1a, which is formed by arranging and fixing multiple battery cells to form an independent module. As an example, a battery module 1a can be formed by bundling multiple battery cells together with cable ties.

[0059] In some embodiments, the battery device 100 may be a battery pack, which includes a housing and one or more battery cell assemblies housed within the housing. As an example, the battery cell assembly may be a battery module 1a, which can be housed within the housing by securing the battery module 1a to the housing. Alternatively, the battery cell assembly may be housed within the housing by directly securing multiple battery cells to the housing.

[0060] In some embodiments, the housing is used to house individual battery cells, and the housing can have various structures.

[0061] In some embodiments, the housing may include a first housing 1b and a second housing 1c, which overlap each other, and together define a receiving space for accommodating a single battery cell. The second housing 1c may be a hollow structure with one open end, and the first housing 1b may be a plate-like structure, with the first housing 1b covering the open side of the second housing 1c so that the first housing 1b and the second housing 1c together define the receiving space. Alternatively, both the first housing 1b and the second housing 1c may be hollow structures with one open side, with the open side of the first housing 1b covering the open side of the second housing 1c. Of course, the housing formed by the first housing 1b and the second housing 1c can be of various shapes, such as a cylinder, a cuboid, etc.

[0062] In some embodiments, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, forming an enclosed space inside the enclosure to house the individual battery cells. As an example, the frame may include multiple side beams.

[0063] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0064] In some embodiments, the battery device 100 may be an energy storage device.

[0065] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, energy storage devices can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours.

[0066] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0067] In some embodiments, there are multiple battery cells, which are first connected in series, parallel, or mixed to form a battery module 1a. The multiple battery modules 1a are then connected in series, parallel, or mixed to form a whole and housed in a housing.

[0068] Multiple battery cells in battery module 1a can be electrically connected via busbars to achieve parallel, series, or mixed connection of the multiple battery cells in battery module 1a. There can be one or more busbars, and each busbar is used to electrically connect at least two battery cells.

[0069] This application provides a battery cell that includes a housing and an electrode assembly housed within the housing.

[0070] In some embodiments, the outer casing may be a steel casing, an aluminum casing, or a composite metal casing (such as a copper-aluminum composite casing).

[0071] The outer shell can be a hollow structure, with an internal cavity for accommodating the electrode assembly and electrolyte.

[0072] In some embodiments, the casing of the battery cell is a cylindrical casing, a square casing, a prismatic casing, or a casing of other shapes.

[0073] In some embodiments, the housing includes a housing and an end cap, the housing having an opening and the end cap being connected to the housing and covering the opening;

[0074] The housing is a component used to fit the end cap to form the internal cavity of the battery cell. The formed internal cavity can be used to house the electrode assembly, electrolyte, and other components.

[0075] The housing and end cap can be separate components. For example, an opening can be provided on the housing, and the end cap can be used to close the opening to form an internal cavity for the battery cell.

[0076] The housing can come in various shapes and sizes, such as cuboid or cylindrical. Specifically, the shape of the housing can be determined based on the specific shape and size of the electrode assembly. The housing can be made of various materials, such as copper, iron, aluminum, stainless steel, and aluminum alloy.

[0077] The shape of the end cap can be adapted to the shape of the housing to fit the housing. The material of the end cap can be the same as or different from that of the housing. Optionally, the end cap can be made of a material with a certain degree of hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.), so that the end cap is not easily deformed when subjected to compression and impact, enabling the battery cell to have higher structural strength and improve reliability.

[0078] The end caps are attached to the housing by welding, bonding, snap-fitting, or other means.

[0079] The housing may be open at one end or at both ends. In some examples, the housing may be a structure with an opening on one side, with one end cap fitting over the housing. In other examples, the housing may be a structure with openings on both sides, with two end caps fitting over the two openings of the housing, respectively.

[0080] Electrode assemblies are the components within a single battery cell where electrochemical reactions occur. The casing may contain one or more electrode assemblies.

[0081] In some embodiments, the electrode assembly includes a positive electrode, a negative electrode, and a separator, wherein the positive electrode and the negative electrode have opposite polarities, and the separator separates the positive electrode and the negative electrode.

[0082] At least a portion of the separator is located between the positive and negative electrode plates. During the charging and discharging of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrode plates. The separator, positioned between the positive and negative electrode plates, serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0083] In some embodiments, the positive electrode may include a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector.

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

[0085] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0086] As an example, the positive electrode film layer includes a positive electrode active material, which may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 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 NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0087] In some embodiments, the negative electrode may include a negative current collector.

[0088] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0089] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector.

[0090] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0091] As an example, the negative electrode film layer includes a negative electrode active material, which may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0092] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0093] In some embodiments, the separator includes a separator membrane. The separator membrane in this application can be any known porous membrane with good chemical and mechanical stability.

[0094] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different.

[0095] Inorganic particle coating, organic particle coating, or organic / inorganic composite coating can also be applied to the surface of the separator.

[0096] The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surface of the positive or negative electrode.

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

[0098] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte used in this application can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0099] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0100] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0101] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0102] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell, such as additives that improve the overcharge / fast charge performance of the battery cell, additives that improve the high-temperature performance of the battery cell, and additives that improve the low-temperature performance of the battery cell.

[0103] In some embodiments, the gel electrolyte comprises a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0104] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0105] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0106] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0107] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0108] In some embodiments, the electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0109] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0110] In some implementations, the electrode assembly is a stacked structure.

[0111] As an example, multiple positive and negative electrode plates can be set, with multiple positive and multiple negative electrode plates stacked alternately. As an example, multiple positive electrode plates can be set, and negative electrode plates are folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0112] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0113] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0114] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0115] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0116] In some embodiments, the positive current collector may include a positive tab, and the negative current collector may include a negative tab. The positive and negative tabs can be used to transmit current. As an example, at least a portion of the positive tab is not coated with a positive film layer, and at least a portion of the negative tab is not coated with a negative film layer.

[0117] In some embodiments, the electrode assembly is a wound structure. The positive electrode tab is wound multiple turns along the winding direction. Optionally, the end of the positive electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked in the axial direction of the electrode assembly. Optionally, the positive electrode tab is annular.

[0118] In some embodiments, the negative electrode tab is wound multiple turns along the winding direction. Optionally, the end of the negative electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked in the axial direction of the electrode assembly. The negative electrode tab is annular.

[0119] In some embodiments, the electrode assembly includes an electrode body. As an example, the electrode body includes a positive electrode film, a portion of the positive electrode current collector covered by the positive electrode film, a negative electrode film, a portion of the negative electrode current collector covered by the negative electrode film, and a separator.

[0120] The positive and negative tabs can be led out from the same end of the electrode body, or they can be led out from opposite ends of the electrode body. At least a portion of the positive tab protrudes to the outside of the insulating member, and at least a portion of the negative tab protrudes to the outside of the insulating member.

[0121] See Figures 3 to 5 , Figure 3 This is an exploded view of a single battery cell provided in an embodiment of this application; Figure 4 This is a partial structural schematic diagram of the end cap assembly and electrode assembly of a battery cell provided in an embodiment of this application; Figure 5 This is a partial structural schematic diagram of the end cap assembly and electrode assembly of a battery cell provided in another embodiment of this application.

[0122] like Figures 3 to 5 As shown, this application proposes a battery cell, which includes a housing 1, an electrode assembly 2, and an end cap assembly 3. The housing 1 has an opening 11. The electrode assembly 2 is disposed within the housing 1 and includes an electrode body 21 and a connecting portion 22 connected to the electrode body 21. The end cap assembly 3 includes an end cap 31, an insulating member 32, and electrode terminals 33. The end cap 31 covers the opening 11, the insulating member 32 is disposed on the side of the end cap 31 facing the electrode assembly 2, the electrode terminals 33 are disposed on the end cap 31, and the connecting portion 22 is welded to the electrode terminals 33. The insulating member 32 includes an insulating body 321 and a positioning structure 322 disposed on the insulating body 321. At least a portion of the connecting portion 22 is located on the side of the insulating body 321 away from the end cap 31. In the same plane perpendicular to the thickness direction z of the end cap 31, at least a portion of the orthographic projection of the connecting portion 22 does not overlap with the orthographic projection of the positioning structure 322.

[0123] Electrode assembly 2 is the component in the battery cell where electrochemical reactions occur.

[0124] In some examples, the housing 1 may contain one or more electrode assemblies 2.

[0125] In some examples, at least a portion of the electrode body 21 and the connecting portion 22 are integral structures.

[0126] Optionally, the connecting part 22 includes a tab 221, and the electrode body 21 is integrally formed with the tab 221.

[0127] In other examples, the electrode body 21 and the connecting part 22 are separate structures.

[0128] Optionally, the connection method between the electrode body 21 and the connecting part 22 includes, but is not limited to, welding, adhesive bonding, and connector connection.

[0129] The end cap assembly 3 is a component used to cooperate with the housing 1 to form the internal cavity of the battery cell. The formed internal cavity can be used to accommodate the electrode assembly 2 and other components.

[0130] The end cap assembly 3 includes an end cap 31 and an insulating member 32. The end cap 31 covers the opening 11 of the housing 1, and the end cap 31 and the housing 1 together form an internal cavity. The insulating member 32 is located on the side of the end cap 31 facing the electrode assembly 2, so as to insulate and separate the end cap 31 and the electrode assembly 2.

[0131] In some embodiments, the end cap 31 may be a generally plate-like structure, such as a circular plate-like structure, a rectangular plate-like structure, or a plate-like structure of other shapes.

[0132] In some embodiments, the end cap 31 may be made of an insulating material (e.g., plastic) or a conductive material (e.g., metal).

[0133] The insulating component 32 serves to insulate between the end cap 31 and the electrode assembly 2, thereby improving the safety performance of the battery cell. The insulating component 32 is made of an insulating material, such as plastic or PVC.

[0134] Electrode terminals 33 are disposed on end cap 31. Electrode terminals 33 are at least partially disposed on the side of end cap 31 facing electrode assembly 2 along the thickness direction z, that is, within the internal space formed by end cap 31 and housing 1.

[0135] In some embodiments, the insulating member 32 is located between the connecting portion 22 and the end cap 31. The insulating member 32 is provided with a through hole along the thickness direction z of the end cap 31 so that the electrode terminal 33 on the end cap 31 can extend into the side of the insulating member 32 near the connecting portion 22 through the through hole, thereby making the electrode terminal 33 electrically connected to the connecting portion 22.

[0136] In some embodiments, the connecting portion 22 is welded to the electrode terminal 33, and the welding method includes laser welding.

[0137] In some embodiments, the positioning structure 322 includes, but is not limited to, a boss, a groove, and a marker line.

[0138] In some embodiments, the positioning structure 322 includes, but is not limited to, a rectangular structure, a rhomboid structure, a triangular structure, a cylindrical structure, a circular structure, or other shaped structures.

[0139] In some examples, the insulating member 32 includes a main body and two protrusions. The main body fits against the end cap 31. The protrusions extend from the surface of the main body away from the end cap 31 and abut against the electrode assembly 2. The two protrusions are disposed at both ends of the main body along the length direction x. A positioning structure 322 is disposed on the main body.

[0140] Optionally, the positioning structure 322 is disposed on the surface of the main body facing the electrode assembly 2.

[0141] The image acquisition unit includes a charge-coupled device (CCD) image acquisition unit, which has advantages such as high sensitivity, resistance to strong light, and low distortion. The CCD image acquisition unit uses the positioning structure 322 as a positioning reference, which helps to improve the welding quality between the connection part 22 and the electrode terminal 33.

[0142] The battery cell provided in this application, by setting a positioning structure 322 on the insulating body 321, ensures that the positioning structure 322 is not obstructed during the welding process between the connecting part 22 and the electrode terminal 33. It serves as a positioning reference for the welding of the connecting part 22 and the electrode terminal 33, aiding in identification and positioning, thereby solving the problem of difficulty in locating the weld center. Furthermore, the positioning structure 322 makes the weld formation position more accurate, thereby improving welding quality, reducing weld defects caused by deviations, and enhancing the reliability of the battery cell. The positioning structure 322 is integrated into the insulating body 321, requiring minimal modification to the overall structure of the end cap assembly 3, and is well-compatible with existing manufacturing processes, reducing the manufacturing cost of the battery cell.

[0143] According to one embodiment of this application, such as Figure 3 and Figure 5 As shown, the positioning structure 322 is recessed inward relative to the surface of the insulating body 321 facing the electrode assembly 2.

[0144] In some examples, along the thickness direction z of the end cap 31, the insulating body 321 has opposing first and second surfaces, with the first surface facing the electrode assembly 2 and the second surface facing the end cap 31. A positioning structure 322 is disposed on the first surface. This facilitates the detection of the position of the positioning structure 322 during the welding process.

[0145] In some examples, the positioning structure 322 is a recessed portion on the surface of the insulating body 321 facing the electrode assembly 2, and the shape of the recess includes, but is not limited to, rectangle, circle, arc, H-shape, U-shape, and ring.

[0146] The positioning structure 322 is formed by various methods, such as milling, stamping, injection molding, and cold heading.

[0147] For example, the positioning structure 322 is formed by stamping.

[0148] The grooved positioning structure 322 provides a clear and three-dimensional contour boundary for CCD recognition, reduces the interference of reflections on the CCD image acquisition unit, makes the positioning reference clearer, and improves positioning accuracy.

[0149] The surface of the insulating body 321 is recessed inward to form a positioning structure 322, which simplifies the formation of the positioning structure 322 and makes the positioning structure 322 easy to process and manufacture.

[0150] According to one embodiment of this application, such as Figure 3 and Figure 4 As shown, the positioning structure 322 protrudes from the surface of the insulating body 321 facing the electrode assembly 2.

[0151] In some examples, the positioning structure 322 is a boss that protrudes from the surface of the insulating body 321 toward the electrode assembly 2.

[0152] The structure of a boss includes, but is not limited to, rectangular, rhomboid, triangular, cylindrical, ring-shaped, or other shaped structures.

[0153] In some examples, the insulating body 321 and the positioning structure 322 are integrally formed.

[0154] Specifically, the insulating component 32 is injection molded to form an insulating body 321 and a positioning structure 322.

[0155] In other examples, the insulating body 321 and the positioning structure 322 are separate structures.

[0156] Specifically, the positioning structure 322 is bonded to the insulating body 321.

[0157] The positioning structure 322 protrudes from the surface of the insulating body 321, forming a significant three-dimensional height difference with the insulating body 321, making it easier to identify as a positioning reference for welding.

[0158] See also Figures 6 to 9 , Figure 6 This is a partial bottom view of the end cap assembly and electrode assembly of a battery cell provided in an embodiment of this application; Figure 7This is a partial bottom view of the end cap assembly and electrode assembly of a battery cell provided in another embodiment of this application; Figure 8 yes Figure 7 Cross-sectional view at point AA; Figure 9 yes Figure 7 Cross-sectional view at BB.

[0159] According to one embodiment of this application, such as Figure 3 , Figures 6 to 9 As shown, in the length direction x of the end cap 31, the positioning structure 322 is disposed on the side of the electrode terminal 33 facing the connection portion 22, and is spaced apart from the electrode terminal 33.

[0160] In some examples, the insulating member 32 includes a main body and two protrusions. The two protrusions are disposed at both ends of the main body along the length direction x. The positioning structure 322 is located between the electrode terminal 33 and the protrusion on its adjacent side.

[0161] In some examples, at least a portion of the connection 22 is located between the protrusion and the electrode terminal 33.

[0162] Optionally, the center line of the positioning structure 322 is parallel to the solder center line of the electrode terminal 33 and the connecting portion 22.

[0163] The positioning structure 322 and the electrode terminal 33 are spaced apart, which makes the positioning reference easy to identify and reduces interference from the electrode terminal 33. When the electrode terminal 33 is welded to the connecting part 22, heat is generated. By keeping the positioning reference and the electrode terminal 33 at a certain distance, the impact of heat on the positioning structure 322 can be reduced, and structural damage to the positioning structure 322 due to heat can be reduced.

[0164] According to one embodiment of this application, the distance L between the positioning structure 322 and the electrode terminal 33 in the length direction x is less than or equal to 60 mm.

[0165] In some examples, the distance L between the positioning structure 322 and the electrode terminal 33 in the length direction x is 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, or other ranges consisting of any two of the above endpoints.

[0166] Optionally, the distance L between the positioning structure 322 and the electrode terminal 33 in the length direction x is less than or equal to 50 mm.

[0167] Alternatively, the distance L between the positioning structure 322 and the electrode terminal 33 in the length direction x is 30 mm to 40 mm.

[0168] The positioning structure 322 and the electrode terminal 33 have a suitable distance, so that the positioning structure 322 is within the recognition range of the CCD image acquisition unit, and the heat effect on the positioning structure 322 can also be reduced.

[0169] According to one embodiment of this application, such as Figure 3 and Figure 7 As shown, the connecting part 22 includes a tab 221 and a current collector 222. The tab 221 is connected to the electrode body 21 and the current collector 222, and the current collector 222 is welded to the electrode terminal 33.

[0170] The tab 221 can be a positive tab 221; or, the tab 221 can be a negative tab 221.

[0171] In some examples, the battery cell includes two connection portions 22, one connection portion 22 having a tab 221 as a positive tab and the other connection portion 22 having a tab 221 as a negative tab. The positive and negative tabs may be located on the same side or on opposite sides.

[0172] During the charging and discharging process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tab 221 is connected to the electrode terminal 33 through the current collector 222 to form a current loop.

[0173] In some examples, the current collector 222 includes a current collector body, an electrode terminal connection portion and an electrode tab connection portion. The current collector body is connected to the electrode terminal connection portion and the electrode tab connection portion. The electrode tab connection portion is used to connect to the electrode tab 221, and the electrode terminal connection portion is used to connect to the electrode terminal 33.

[0174] Optionally, the current collector 222 is connected to the electrode terminal 33 by welding, and the current collector 222 is connected to the tab 221 by welding. The two connection methods can be the same or different.

[0175] According to one embodiment of this application, such as Figures 3 to 9 As shown, the flow collecting component 222 is provided with a through groove 2221. In the thickness direction z of the end cap 31, the through groove 2221 is arranged opposite to the positioning structure 322. The through groove 2221 is used to expose the positioning structure 322.

[0176] The through groove 2221 is a groove that extends through the flow collector 222 along the thickness direction z of the end cap 31. Specifically, the end cap 31 of the flow collector 222 has two opposing surfaces in the thickness direction z, and the through groove 2221 connects the first surface and the second surface.

[0177] In some examples, the flow collector 222 is provided with a through groove 2221 extending along the thickness direction z of the end cap 31.

[0178] In some examples, the structure of the through slot 2221 includes, but is not limited to, rectangular, circular, arc-shaped, H-shaped, U-shaped, and annular structures.

[0179] Optionally, the structure of the through groove 2221 is matched with the structure of the positioning structure 322.

[0180] For example, the positioning structure 322 is a rectangular boss, and the through groove 2221 is a rectangular groove.

[0181] For example, the positioning structure 322 is a circular recess, and the through groove 2221 is a circular groove.

[0182] In some examples, in the thickness direction z of the end cap 31, a portion of the positioning structure 322 is embedded in the through groove 2221, and another portion protrudes from the through groove 2221 and extends toward the electrode body 21.

[0183] In some examples, the positioning structure 322 is embedded in the through groove 2221 in the thickness direction z of the end cap 31.

[0184] Optionally, the positioning structure 322 is a boss that protrudes from the surface of the insulating body 321 facing the electrode assembly 2. The boss is accommodated in the through groove 2221 and does not extend beyond the through groove 2221.

[0185] Within the narrow space inside the battery cell, the through slot 2221 allows the positioning structure 322 to be quickly identified, reducing the obstruction of the positioning structure 322 by the current collector 222.

[0186] According to one embodiment of this application, such as Figure 6 and Figure 7 As shown, the through groove 2221 is disposed at the end of the current collector 222 away from the electrode terminal 33 along the length direction x.

[0187] In some examples, the current collector 222 has a first end and a second end along the length direction x, the first end being used to connect to the electrode terminal 33, the second end being used to connect to the tab 221, and a through groove 2221 being provided at the first end.

[0188] The connection methods between the current collector 222 and the electrode 221 include, but are not limited to, welding, conductive adhesive connection, conductive connector connection, snap-fit, and plug-in connection.

[0189] Optionally, the through groove 2221 extends to the end of the flow collector 222 along the length direction x.

[0190] Alternatively, the through slot 2221 can be a notched through slot.

[0191] The through groove 2221 is located at the end of the current collector 222 away from the terminal, which reduces the impact on the welding of the current collector 222 and the electrode terminal 33, so that the weld mark formed by the current collector 222 and the electrode terminal 33 has a suitable area, thereby making the two have high connection stability.

[0192] According to one embodiment of this application, such as Figure 4 and Figure 6 As shown, the positioning structure 322 protrudes from the surface of the insulating body 321 facing the electrode assembly 2, and the positioning structure 322 is fitted into the through groove 2221.

[0193] In some examples, in the thickness direction z of the end cap 31, the height of the positioning structure 322 is less than or equal to the depth of the through groove 2221.

[0194] The positioning structure 322 and the through groove 2221 are interlocked to limit the flow collection component 222, restrict the flow collection component 222 from shifting after installation, and improve the assembly stability of the flow collection component 222.

[0195] According to one embodiment of this application, such as Figure 6 and Figure 7 As shown, the current collector 222 includes a first welding area 2222 and a second welding area 2223. The second welding area 2223 is disposed at one end of the current collector 222 away from the first welding area 2222 along the length direction x. The first welding area 2222 is used to connect with the electrode terminal 33, and the second welding area 2223 is used to connect with the tab 221. The second welding area 2223 is located on at least one side of the through groove 2221 along the width direction y of the end cap 31.

[0196] The width direction (y), thickness direction (z), and length direction (x) of the end cap 31 are perpendicular to each other.

[0197] In some examples, the first welding area 2222 and the second welding area 2223 are located at both ends of the length direction x.

[0198] In some examples, the welding method of tab 221 to current collector 222 is the same as the welding method of electrode terminal 33 to current collector 222; alternatively, the welding method of tab 221 to current collector 222 is different from the welding method of electrode terminal 33 and current collector 222.

[0199] The current collecting member 222 includes a main body section and two connecting sections. The connecting sections are disposed along the length direction x on the side of the main body section facing the positioning structure 322. The two connecting sections are spaced apart along the width direction y, and the two connecting sections and the main body section enclose a through groove 2221. At least one connecting section is welded to the electrode tab 221 to form at least a portion of the second welding area 2223.

[0200] Optionally, a portion of the main body is welded to the tab 221 to form a portion of the second welding zone 2223.

[0201] In some examples, the second welding zone 2223 is spaced apart from the opening of the through groove 2221. This reduces the structural deformation of the through groove 2221 caused by the conduction of welding heat from the tab 221 and the current collector 222 to the periphery of the through groove 2221.

[0202] The through slot 2221 is located at the end of the current collector 222, but not in the main conductive area in the middle of the current collector 222, thereby reducing the impact on current transmission.

[0203] According to one embodiment of this application, such as Figure 6 and Figure 7 As shown, the second welding area 2223 is located on both sides of the through groove 2221 along the width direction y.

[0204] In some examples, the size of the positioning structure 322 is smaller than the size of the electrode terminal 33 in the width direction y of the end cap 31. This reduces the space occupied by the positioning structure 322 while meeting the positioning reference.

[0205] In some examples, the total dimension of the second welding area 2223 is larger than the dimension of the through groove 2221 in the width direction y of the end cap 31. This ensures sufficient welding area between the tab 221 and the current collector 222, resulting in high connection stability between the two.

[0206] A second welding zone 2223 is provided on both sides of the through groove 2221 to improve the problem of stress concentration caused by welding.

[0207] According to one embodiment of this application, such as Figure 4 and Figure 5 As shown, the battery cell includes two electrode terminals 33 and two connecting portions 22. The insulating member 32 includes two positioning structures 322, and the two electrode terminals 33 are located between the two positioning structures 322 in the longitudinal direction x of the end cap 31.

[0208] In some examples, one of the two electrode terminals 33 is a positive electrode terminal and the other is a negative electrode terminal.

[0209] As an example, the two connection parts 22 include a positive electrode tab and a negative electrode tab, which are located on the same side. The positive electrode tab is connected to the positive electrode terminal through a current collector 222, and the negative electrode tab is connected to the negative electrode terminal through another current collector 222.

[0210] According to one embodiment of this application, the length of the battery cell is 220mm to 400mm.

[0211] Due to the limited space for the electrode assembly 2 inside the battery cell and the constraint of the center distance of the electrode terminals 33, the adjustability of the welding position between the connection portion 22 and the electrode terminals 33 decreases. Furthermore, as the length of the battery cell increases, the distance between the protrusions at both ends of the insulating member 32 in the x-direction and the connection portion 22 increases, further exacerbating the difficulty of welding positioning. Therefore, this affects the stability of welding quality and easily leads to defects such as weld misalignment and incomplete welding.

[0212] In some examples, the length of the battery cell is 220mm, 230mm, 240mm, 250mm, 260mm, 270mm, 280mm, 290mm, 300mm, 310mm, 320mm, 330mm, 340mm, 350mm, 360mm, 370mm, 380mm, 390mm, 400mm, or other ranges consisting of any two of the above endpoints.

[0213] Optionally, the length of the battery cell is 260mm to 380mm.

[0214] Alternatively, the length of the battery cell can be 300mm to 380mm.

[0215] In some examples, the thickness of the battery cell is 18mm to 30mm. The thinness of the battery cell also increases the difficulty of positioning the CCD image acquisition unit. By setting a positioning structure 322 in the insulating body 321, stable welding of the electrode terminals 33 of the thin and long battery cell can be achieved.

[0216] Specifically, the thickness of the battery cell is 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm or other ranges consisting of any two of the above endpoints.

[0217] A positioning structure 322 is provided in the insulating body 321 to assist the CCD image acquisition unit in precise positioning, so as to be applicable to long battery cells, improve welding quality, improve poor welding marks caused by deviation, and improve the reliability of battery cells.

[0218] Secondly, this application provides a battery device including the aforementioned battery cell.

[0219] Thirdly, this application provides an electrical device including a battery cell or a battery device as described above, wherein the battery cell or battery device is used to store or provide electrical energy.

[0220] According to some embodiments of this application, such as Figure 3 , Figure 4 and Figure 6As shown, this application provides a battery cell, which includes a housing 1, an electrode assembly 2, and an end cap assembly 3. The length of the battery cell is 220mm to 400mm.

[0221] The housing 1 has an opening 11.

[0222] Electrode assembly 2 is disposed within housing 1. Electrode assembly 2 includes electrode body 21 and connecting portion 22 connected to electrode body 21. At least a portion of connecting portion 22 is located on the side of insulating body 321 opposite to end cap 31. Connecting portion 22 includes tab 221 and current collector 222, tab 221 being connected to electrode body 21 and current collector 222. Current collector 222 includes a first welding area 2222 and a second welding area 2223, the second welding area 2223 being located at the end away from the first welding area 2222 in the length direction x. Current collector 222 has a through groove 2221, and the second welding area 2223 is located on both sides of through groove 2221 along the width direction y of end cap 31. Second welding area 2223 is used to connect with tab 221.

[0223] The end cap assembly 3 includes an end cap 31, an insulating member 32, and an electrode terminal 33. The end cap 31 covers the opening 11, the insulating member 32 is disposed on the side of the end cap 31 facing the electrode assembly 2, and the electrode terminal 33 is disposed on the end cap 31. A first welding area 2222 is used to connect with the electrode terminal 33. The insulating member 32 includes an insulating body 321 and a positioning structure 322 disposed on the insulating body 321. The positioning structure 322 is used as a positioning reference for welding the current collector 222 to the electrode terminal 33. The positioning structure 322 protrudes from the surface of the insulating body 321 facing the electrode assembly 2. The positioning structure 322 engages with the through groove 2221.

[0224] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The shell has an opening; An electrode assembly is disposed within the housing, the electrode assembly including an electrode body and a connecting portion connected to the electrode body; An end cap assembly includes an end cap, an insulating member, and electrode terminals. The end cap closes to the opening. The insulating member is disposed on the side of the end cap facing the electrode assembly. The electrode terminals are disposed on the end cap. A connecting portion is welded to the electrode terminals. The insulating member includes an insulating body and a positioning structure disposed on the insulating body. At least a portion of the connecting portion is located on the side of the insulating body away from the end cap. In the same plane perpendicular to the thickness direction of the end cap, at least a portion of the orthographic projection of the connecting portion does not overlap with the orthographic projection of the positioning structure.

2. The battery cell according to claim 1, characterized in that, The positioning structure is recessed inward relative to the surface of the insulating body facing the electrode assembly.

3. The battery cell according to claim 1, characterized in that, The positioning structure protrudes from the surface of the insulating body facing the electrode assembly.

4. The battery cell according to claim 1, characterized in that, Along the length of the end cap, the positioning structure is disposed on the side of the electrode terminal facing the connection portion, and is spaced apart from the electrode terminal.

5. The battery cell according to claim 4, characterized in that, In the length direction, the distance L between the positioning structure and the electrode terminal is less than or equal to 60 mm.

6. The battery cell according to claim 1, characterized in that, The connection part includes a tab and a current collector. The tab is connected to the electrode body and the current collector, and the current collector is welded to the electrode terminal.

7. The battery cell according to claim 6, characterized in that, The flow collecting component is provided with a through groove. In the thickness direction of the end cap, the through groove is disposed opposite to the positioning structure, and the through groove is used to expose the positioning structure.

8. The battery cell according to claim 7, characterized in that, The through slot is located at the end of the current collecting member away from the electrode terminal along the length of the end cap.

9. The battery cell according to claim 7, characterized in that, The positioning structure protrudes from the surface of the insulating body facing the electrode assembly, and the positioning structure is fitted into the through groove.

10. The battery cell according to claim 7, characterized in that, The current collecting component includes a first welding area and a second welding area. The second welding area is disposed at one end of the current collecting component away from the first welding area along the length direction of the end cap. The first welding area is used to connect with the electrode terminal, and the second welding area is used to connect with the tab. The second welding area is located on at least one side of the through groove along the width direction of the end cap.

11. The battery cell according to claim 10, characterized in that, The second welding area is located on opposite sides of the through groove along the width direction.

12. The battery cell according to claim 1, characterized in that, The battery cell includes two electrode terminals and two connecting portions; The insulating component includes two positioning structures, with the two electrode terminals located between the two positioning structures along the length of the end cap.

13. The battery cell according to claim 1, characterized in that, The length of the battery cell is 220mm to 400mm.

14. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1 to 13.

15. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1 to 13 or a battery device according to claim 14, wherein the battery cell or the battery device is used to store or provide electrical energy.

Images