Battery cell, battery device, and electric device

Abstract

The application relates to a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrode assembly, an end cover assembly and an insulating film. The shell has an opening. The electrode assembly is arranged in the shell, and the electrode assembly comprises an electrode body and a tab, the electrode body has an end face and an outer peripheral surface, and the tab extends from the end face. The end cover assembly comprises an end cover and an insulating part, the end cover covers the opening, and the insulating part is arranged on the side of the end cover facing the electrode assembly. The insulating film surrounds the outer peripheral surface, and at least part of the insulating film is welded with the surface of the insulating part away from the end cover to form a connecting part. The battery monomer provided by the application has high stability in the welding of the insulating film and the insulating part, thereby improving the reliability of the battery monomer.

Description

Technical Field

[0001] This application relates to the field of battery manufacturing technology, and in particular to battery cells, battery devices, and electrical devices. 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 device, which aim to improve the reliability of the battery cell to a certain extent.

[0005] In a first aspect, this application proposes a battery cell, comprising a housing, an electrode assembly, an end cap assembly, and an insulating film. The housing has an opening. The electrode assembly is disposed within the housing and includes an electrode body and a tab. The electrode body has an end face and an outer peripheral face, and the tab extends from the end face. The end cap assembly includes an end cap and an insulating member. The end cap closes the opening, and the insulating member is disposed on the side of the end cap facing the electrode assembly. The insulating film surrounds the outer peripheral face, and at least a portion of the insulating film is fused to the surface of the insulating member opposite to the end cap to form a connection.

[0006] The battery cell provided in this application has at least a portion of the insulating film fused to the surface of the insulating component away from the end cap to form a connection. This effectively expands the fusible area of ​​the insulating component. Sufficient fusion area improves the strength and reliability of the fusion between the insulating film and the insulating component, resulting in a tighter bond and reducing the probability of failures such as desoldering, thus improving the reliability of the battery cell. Furthermore, the insulating film and the insulating component can be fused together first to form a connection before the insulating film covers the electrode assembly. This reduces damage to the electrode assembly caused by high-temperature fusion, thereby reducing the risk of short circuits in the battery cell due to electrode assembly damage, further improving the battery cell's lifespan and reliability.

[0007] According to one embodiment of this application, along the direction from the end cap assembly to the electrode body, the insulating film is located on the side of the insulating component facing the electrode body.

[0008] In these alternative embodiments, the insulating film is located on the side of the insulating component facing the electrode body, which can constrain the insulating film to suppress the expansion and contraction of the electrode assembly during use.

[0009] According to one embodiment of this application, the insulating component includes an insulating body and a protrusion. The insulating body is fitted to an end cap; the protrusion protrudes from the surface of the insulating body opposite to the end cap, and an insulating film is fused to the surface of the protrusion opposite to the insulating body to form a connection.

[0010] In these alternative embodiments, this arrangement improves the strength and structural stability of the weld between the insulating film and the insulating components. It also reduces the amount of insulating film used, thereby lowering manufacturing costs.

[0011] According to one embodiment of this application, the protrusion includes a recess that is recessed relative to the surface of the protrusion facing the electrode body, and at least a portion of the wall of the recess is fused with insulating adhesive.

[0012] In these alternative embodiments, the connection portion is formed within the recess, effectively reducing the additional space occupied by the battery cell's height, which is beneficial for improving energy density and space utilization. Furthermore, the recess provides an independent accommodating space for the welded connection portion, reducing the risk of wear on the electrode body and improving the reliability of the battery cell.

[0013] According to one embodiment of this application, the recess extends to the edge of the protrusion in a direction perpendicular to the direction of the end cap assembly pointing towards the electrode body, and at least a portion of the recess does not overlap with the electrode body in the direction of the end cap assembly pointing towards the electrode body.

[0014] In these alternative embodiments, the electrode body can be retracted into the insulating body, which to some extent forms a retracting and fixing effect on the electrode body, thereby reducing damage to the electrode assembly.

[0015] According to one embodiment of this application, at least a portion of the recess is arc-shaped.

[0016] In these alternative embodiments, the shape of the recess matches a portion of the insulating film structure, allowing for a tight fit and positioning between the two.

[0017] According to one embodiment of this application, the insulating component includes a plurality of protrusions, which are spaced apart along a first direction, and each protrusion has at least one recess. The first direction is perpendicular to the direction from which the end cap assembly points to the electrode body.

[0018] In these alternative embodiments, this configuration enables large-area, multi-point welding. This improves the strength and reliability of the weld, and also gives the battery cells higher stability and reliability.

[0019] According to one embodiment of this application, the plurality of protrusions includes two first protrusions, which are disposed at both ends of the main body along a first direction. The wall surface of the recess of the first protrusion forms a plurality of connecting portions with the insulating film. The plurality of connecting portions are spaced apart along the extension direction of the recess, and adjacent connecting portions are connected by the insulating film.

[0020] In these alternative embodiments, this arrangement further improves the weld stability between the insulating component and the insulating film.

[0021] According to one embodiment of this application, the insulating film includes a first film and a second film connected together. The first film is disposed between the electrode body and the insulating component. At least a portion of the first film is fused to the surface of the protrusion facing away from the insulating body to form a connection portion. At least a portion of the second film surrounds the outer peripheral surface and is connected to the outer peripheral surface. In the direction of the end cap assembly pointing towards the electrode body, the first film has an opening for exposing at least a portion of the electrode assembly.

[0022] In these alternative embodiments, the first membrane is fused to the insulating body to achieve stable installation of the insulating membrane, and the second membrane is connected to the outer peripheral surface to reduce the occurrence of insulating membrane detachment. Furthermore, the insulating membrane can also restrict the isolation membrane located at the outermost ring of the electrode assembly, thereby suppressing its thermal expansion and contraction under heat and reducing short-circuit points.

[0023] According to one embodiment of this application, the outer peripheral surface includes two straight sections and two bent sections. The two straight sections are spaced apart along a second direction, and the two bent sections are spaced apart along a first direction. The bent sections are connected to the two straight sections. The end cap assembly is perpendicular to the direction of the electrode body, the first direction, and the second direction. The second membrane includes two first parts and two second parts. The two first parts are spaced apart along the first direction. The first parts are bent relative to the first membrane and connected to the bent sections. The second parts are bent relative to the first membrane and connected to the straight sections. The second parts are connected to the two adjacent first parts.

[0024] In these alternative embodiments, the two first portions and the two second portions cover the outer peripheral surface of the electrode body, providing good shaping and insulation for the electrode body.

[0025] According to one embodiment of this application, the second part includes a first segment and two second segments. The first segment is bent relative to the first membrane and connected to the straight segment. The second segment is bent relative to the first segment and attached to the first part. The two second segments are disposed at both ends of the first segment along a first direction.

[0026] According to one embodiment of this application, there are multiple connecting parts, with at least one connecting part connected to a first part and at least one connecting part connected to a second part.

[0027] In these alternative embodiments, multiple connecting portions are connected to the second membrane body to improve the overall structural stability of the insulating film and reduce the occurrence of insulating film detachment.

[0028] According to one embodiment of this application, the second membrane further includes a third portion connected to the first portion and the second portion. The third portion includes a third segment, a fourth segment, and two fifth segments. In the direction from the end cap assembly to the electrode body, at least a portion of the third segment is disposed opposite to the end face. The third segment is bent relative to one of the second portions. The fourth segment is bent relative to the third segment and adheres to another second portion. The fifth segment is bent relative to the third segment and adheres to the first portion. The two fifth segments are disposed opposite to each other along a first direction.

[0029] In these alternative embodiments, this arrangement allows the insulating film to more tightly cover the electrode body.

[0030] Secondly, this application provides a battery device including the aforementioned battery cell.

[0031] 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.

[0032] 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

[0033] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0034] Figure 1 This is a schematic diagram of the structure of a vehicle provided in one embodiment of this application;

[0035] Figure 2 This is an exploded view of a battery device provided in an embodiment of this application;

[0036] Figure 3 This is an exploded view of a single battery cell provided in an embodiment of this application;

[0037] Figure 4 This is a partial exploded view of a battery cell provided in one embodiment of this application;

[0038] Figure 5 This is a schematic diagram of the end cap assembly and insulating film of a battery cell provided in an embodiment of this application;

[0039] Figure 6 This is a schematic diagram of the combined structure of the end cap assembly and insulating film of a battery cell according to an embodiment of this application;

[0040] Figure 7This is a partial structural schematic diagram of the end cap assembly and insulating film of a battery cell provided in an embodiment of this application;

[0041] Figure 8 This is a schematic diagram of the end cap assembly and part of the insulating film structure of a battery cell provided in an embodiment of this application.

[0042] The accompanying drawings may not be drawn to scale.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1000, Vehicle; 100, Battery Unit; 200, Controller; 300, Motor; 1a, Battery Module; 1b, First Housing; 1c, Second Housing; 10, Battery Cell; 1, Housing; 11, Opening; 2, Electrode Assembly; 21, Electrode Body; 211, End Face; 212, Outer Peripheral Surface; 2121, Straight Section; 2122, Bending Section; 22, Tab; 3, End Cap Assembly; 31, End Cap; 32, Insulating Component; 321, Insulating Main 322, convex body; 322a, first convex body; 322b, second convex body; 3221, recess; 4, insulating film; 41, first film body; 411, opening; 42, second film body; 421, first part; 422, second part; 4221, first segment; 4222, second segment; 423, third part; 4231, third segment; 4232, fourth segment; 4233, fifth segment; 5, connecting part; x, first direction; y, second direction. Detailed Implementation

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] In this application, "multiple" means two or more (including two).

[0052] 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.

[0053] 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.

[0054] During the assembly of a battery cell, the insulating film of the separator electrode assembly and the housing needs to be connected to the insulating components in the end cap assembly. In related technologies, the insulating film and the sides of the insulating components are fixed together by welding. However, in order to improve the energy density and space utilization of the battery cell, the height and width of the insulating components are becoming smaller and smaller, which limits the welding area between the insulating film and the sides of the insulating components, resulting in insufficient welding strength. When the battery cell is subjected to vibration or gravity, the insulating film is prone to displacement or even detachment, causing the electrode assembly to contact the housing, leading to a short circuit risk and reducing the 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.

[0055] The battery cell provided in this application has at least a portion of the insulating film fused to the surface of the insulating component away from the end cap to form a connection. This effectively expands the fusible area of ​​the insulating component. Sufficient fusion area improves the strength and reliability of the fusion between the insulating film and the insulating component, resulting in a tighter bond and reducing the probability of failures such as desoldering, thus improving the reliability of the battery cell. Furthermore, the insulating film and the insulating component can be fused together first to form a connection before the insulating film covers the electrode assembly. This reduces damage to the electrode assembly caused by high-temperature fusion, thereby reducing the risk of short circuits in the battery cell due to electrode assembly damage, further improving the battery cell's lifespan and reliability.

[0056] 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.

[0057] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, among others. 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.

[0058] For ease of explanation, the following embodiments will be described using a vehicle as an example of an electrical device according to an embodiment of this application.

[0059] See Figure 1As 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.

[0060] Please refer to Figure 2 , Figure 2 An exploded view of a battery device 100 provided in some embodiments of this application.

[0061] In some embodiments, the battery device 100 may include one or more battery cell assemblies for providing voltage and capacity.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] In some embodiments, the housing is used to house individual battery cells, and the housing can have various structures.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] In some embodiments, the battery device 100 may be an energy storage device.

[0073] 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.

[0074] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0075] 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.

[0076] 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.

[0077] This application provides a battery cell that includes a housing and an electrode assembly housed within the housing.

[0078] 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).

[0079] The outer shell may be a hollow structure, with an internal cavity 20b for accommodating the electrode assembly and electrolyte.

[0080] 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.

[0081] 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;

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] The end caps are attached to the housing by welding, bonding, snap-fitting, or other means.

[0087] 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.

[0088] Electrode assemblies are the components within a single battery cell where electrochemical reactions occur. The casing may contain one or more electrode assemblies.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.).

[0094] 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.

[0095] In some embodiments, the negative electrode may include a negative current collector.

[0096] 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.).

[0097] 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.

[0098] 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.

[0099] 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.

[0100] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0101] 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.

[0102] 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.

[0103] Inorganic particle coating, organic particle coating, or organic / inorganic composite coating can also be applied to the surface of the separator.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0113] 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.

[0114] 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.

[0115] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0116] In some embodiments, the electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0117] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0118] In some implementations, the electrode assembly is a stacked structure.

[0119] 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.

[0120] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0121] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0122] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0123] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0124] 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.

[0125] In some embodiments, the electrode assembly is a wound structure. The positive electrode tab is wound multiple turns along the winding direction V. 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.

[0126] In some embodiments, the negative electrode tab is wound multiple turns along the winding direction V. Optionally, the end of the negative electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked axially on the electrode assembly. The negative electrode tab is annular.

[0127] In some embodiments, the electrode assembly includes an electrode body 10c. As an example, the electrode body 10c includes a positive electrode film layer, a portion of the positive electrode current collector covered by the positive electrode film layer, a negative electrode film layer, a portion of the negative electrode current collector covered by the negative electrode film layer, and a separator.

[0128] The positive and negative tabs can be led out from the same end of the electrode body 10c, or they can be led out from opposite ends of the electrode body 10c. 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.

[0129] 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 exploded view of a battery cell provided in one embodiment of this application; Figure 5 This is a schematic diagram of the end cap assembly and insulating film of a battery cell provided in an embodiment of this application.

[0130] like Figures 3 to 5 As shown, this application proposes a battery cell 10, which includes a housing 1, an electrode assembly 2, an end cap assembly 3, and an insulating film 4. 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 tab 22. The electrode body 21 has an end face 211 and an outer peripheral face 212, and the tab 22 extends from the end face 211. The end cap assembly 3 includes an end cap 31 and an insulating member 32. The end cap 31 closes the opening 11, and the insulating member 32 is disposed on the side of the end cap 31 facing the electrode assembly 2. The insulating film 4 surrounds the outer peripheral face 212, and at least a portion of the insulating film 4 is fused to the surface of the insulating member 32 away from the end cap 31 to form a connection portion 5.

[0131] The housing 1 has an opening 11. The housing 1 is a component used to fit the end cap assembly 3 to form the internal cavity of the battery cell, and the formed internal cavity can be used to accommodate the electrode assembly 2, the electrolyte, and other components.

[0132] In the embodiments of this application, the housing 1 can be of various shapes, such as a cylinder, cuboid, or prism. The shape of the housing 1 can be determined according to the specific shape of the electrode assembly 2. For example, if the electrode assembly 2 is a cylindrical structure, then a cylindrical housing 1 can be selected.

[0133] In some embodiments, the housing 1 is used to house the electrode assembly 2, and may also be used to house electrolyte, etc. The housing 1 may be made of various materials, such as copper, iron, aluminum, steel or aluminum alloy, etc.

[0134] Electrode assembly 2 is the component in a battery cell where electrochemical reactions occur, and may include one or more electrode assemblies 2. The structure of electrode assembly 2 can be various. Electrode assembly 2 can be a wound structure formed by winding a positive electrode, a separator, and a negative electrode, or a stacked structure formed by layering positive electrode, a separator, and a negative electrode.

[0135] The portions of the positive and negative electrode plates that do not contain active material each constitute electrode tabs 22. The positive electrode tabs 22 and the negative electrode tabs 22 can be located together at one end of the main body or at two separate ends of the main body.

[0136] Electrode assembly 2 includes electrode body 21. The portions of the positive and negative electrode plates containing active materials constitute the electrode body 21.

[0137] As an example, the electrode body 21 includes a positive electrode film layer, a portion of the positive electrode current collector covered by the positive electrode film layer, a negative electrode film layer, a portion of the negative electrode current collector covered by the negative electrode film layer, and a separator.

[0138] The electrode assembly 2 also includes tabs 22. Tabs 22 extend from the electrode body 21.

[0139] In some examples, the tab 22 can be a positive tab and at least partially protrude to the outside of the electrode body 21.

[0140] In other examples, the tab 22 may be a negative tab and may protrude at least partially outward from the electrode body 21.

[0141] In some examples, the electrode body 21 includes an end face 211 and an outer peripheral face 212. The end face 211 faces the end cap 31, and an electrode tab 22 extends from the end face 211, such that the electrode tab 22 is located between the electrode body 21 and the end cap 31 and is located on the same side of the electrode body 21. The outer peripheral face 212 is connected to the end face 211 and is disposed on the side of the end face 211 opposite to the end cap 31.

[0142] In some examples, the electrode assembly 2 is a wound structure formed by winding a positive electrode, an insulator and a negative electrode, with the outer peripheral surface 212 being the outermost ring of the electrode assembly 2.

[0143] 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 accommodate the electrode assembly 2, the insulating film 4, and other components. The insulating component 32 is located on the side of the end cap 31 facing the electrode assembly 2 to insulate and separate the end cap 31 and the electrode assembly 2. The insulating component 32 serves to provide insulation between the end cap 31 and the electrode assembly 2 to improve the safety performance of the battery cell.

[0144] In some examples, the insulating component 32 is made of an insulating material, such as plastic or PVC.

[0145] For example, the insulating component 32 and the end cap 31 can be connected by means of adhesive, snap-fit ​​or threaded connection.

[0146] At least a portion of the insulating film 4 is located between the electrode assembly 2 and the housing 1. The insulating film 4 serves to separate at least a portion of the electrode assembly 2 from the housing 1 for shaping and insulating the electrode assembly 2.

[0147] Specifically, the insulating film 4 covers the outer surface of the electrode assembly 2.

[0148] In some examples, the insulating film 4 can be a sheet material or a film material.

[0149] In some examples, the insulating film 4 can be a soft material or a hard material.

[0150] In some examples, the part can be made of plastic, silicone, or other plastic materials.

[0151] In some embodiments of this application, the insulating film 4 is a Mylar film. Alternatively, the insulating film 4 may also be a plastic insulating sheet. The insulating film 4 wraps around the outer peripheral surface 212 of the electrode body 21, and extends beyond the electrode body 21 in the direction from the electrode body 21 to the end cap assembly 3, so as to be able to connect with the insulating component 32.

[0152] At least a portion of the insulating film 4 is fused to the surface of the insulating component 32 away from the end cap 31 to form a connecting portion 5. This can be understood as the insulating film 4 being fused to the surface of the insulating component 32 facing the electrode body 21, and the connecting portion 5 being the part where the surface of the insulating component 32 away from the end cap 31 and the insulating film 4 are connected to each other.

[0153] To achieve higher energy density and greater space utilization, the height and width of the lower insulating component 32 in battery cells are decreasing, resulting in a smaller area suitable for heat-fusion welding. This leads to problems such as detachment of the welded insulating film and potential burns to the electrode body 21, causing short circuits and failures. Therefore, the insulating film 4 is welded to the surface of the insulating component 32 away from the end cap 31, providing a larger welding area to improve the welding stability between the insulating film 4 and the insulating component 32. The connecting portion 5 is a weld mark formed by heat-fusion welding.

[0154] In some examples, a portion of the insulating film 4 is located between the insulating component 32 and the electrode body 21, whereby it is fused with the insulating component 32 to form a connection portion 5.

[0155] Optionally, at least a portion of the insulating film 4 is thermally bonded to the insulating component 32. The thermal bonding employs a welding head to transfer heat to the bonding interface, causing the surface of the insulating film 4 to melt and bond with the insulating component 32 to form a welded portion.

[0156] The battery cell provided in this application has at least a portion of the insulating film 4 fused to the surface of the insulating component 32 away from the end cap 31 to form a connection portion 5. This effectively expands the fusible area of ​​the insulating component 32. Sufficient fusion area improves the strength and reliability of the fusion between the insulating film 4 and the insulating component 32, resulting in a tighter bond between them and reducing the probability of fusion failure and other problems, thus improving the reliability of the battery cell. Furthermore, the insulating film 4 and the insulating component 32 can be fused together first to form the connection portion 5, and then the insulating film 4 can be used to cover the electrode assembly 2. This reduces the damage to the electrode assembly 2 caused by high-temperature fusion, thereby reducing the risk of short circuits in the battery cell due to damage to the electrode assembly 2, further improving the service life and reliability of the battery cell.

[0157] According to one embodiment of this application, such as Figure 4 As shown, along the direction from the end cap assembly 3 to the electrode body 21, the insulating film 4 is located on the side of the insulating component 32 facing the electrode body 21.

[0158] In some examples, along the direction from the end cap assembly 3 to the electrode body 21, the insulating member 32 has opposing first and second surfaces. The first surface faces the electrode body 21, i.e., away from the end cap 31, while the second surface faces the end cap 31. The insulating film 4 is located on one side of the first surface and is fused to the first surface to form a connection portion 5. The insulating film 4 does not extend beyond the first surface.

[0159] In these alternative embodiments, the insulating film 4 is located on the side of the insulating component 32 facing the electrode body 21, which can constrain the insulating film 4 to suppress the expansion and contraction of the electrode assembly 2 during use.

[0160] According to one embodiment of this application, such as Figure 4 and Figure 5 As shown, the insulating component 32 includes an insulating body 321 and a protrusion 322. The insulating body 321 is attached to the end cap 31. The protrusion 322 protrudes from the surface of the insulating body 321 away from the end cap 31, and the insulating film 4 is fused to the surface of the protrusion 322 away from the end cap 31 to form a connecting portion 5.

[0161] In some examples, the insulating component 32 may include one or more protrusions 322, which are spaced apart from the insulating body 321.

[0162] The insulating body 321 and the end cap 31 are stacked along the thickness direction. The protrusion 322 protrudes from the surface of the insulating body 321 away from the end cap 31, and the end of the protrusion 322 away from the insulating body 321 can directly press against the electrode body 21.

[0163] In some examples, a portion of the surface of the protrusion 322 away from the end cap 31 is fused with the insulating film 4 to form a connection portion 5. Alternatively, the surface of the protrusion 322 away from the end cap 31 is fused with the insulating film 4 to form a connection portion 5.

[0164] In some examples, a protrusion 322 is provided at the end of the insulating body 321.

[0165] In other examples, a protrusion 322 is disposed in the middle portion of the insulating body 321.

[0166] First, the insulating film 4 and the surface of the protrusion 322 facing away from the end cap 31 are fused together to form the connecting part 5, and then the electrode assembly 2 is connected to the end cap assembly 3. In this way, the impact of high temperature on the electrode assembly 2 during the fusion process can be reduced, thus improving the performance and lifespan of the electrode assembly 2.

[0167] The insulating film 4 and the protrusion 322 are fused together on the surface away from the end cap 31 to form a connecting part 5, which is connected and operated synchronously with the electrode assembly 2 and the end cap assembly 3.

[0168] In these alternative embodiments, this arrangement improves the strength and structural stability of the weld between the insulating film 4 and the insulating component 32. It also reduces the amount of insulating film 4 used, thus lowering manufacturing costs.

[0169] According to one embodiment of this application, such as Figure 4 and Figure 5 As shown, the protrusion 322 includes a recess 3221, which is recessed relative to the surface of the protrusion 322 facing the electrode body 21, and at least a portion of the wall of the recess 3221 is fused to the insulating film 4.

[0170] The insulating film 4 and the protrusion 322 can be stably fused to the surface of the end cap 31 away from the end cap 31. However, this fusion will occupy the height space of the battery cell, and the height is parallel to the direction of the end cap assembly 3 pointing towards the electrode body 21. In addition, the connection portion 5 formed by the fusion of the insulating film 4 and the protrusion 322 is uneven, and the connection portion 5 is in direct contact with the electrode body 21, which may cause wear to the electrode body 21.

[0171] In some examples, the protrusion 322 includes a recess 3221 that is recessed relative to the surface of the protrusion 322 facing the electrode body 21. A portion of the wall of the recess 3221 is fused with the insulating film 4 to form a connection 5 that does not protrude from the recess 3221.

[0172] For example, the protrusion 322 includes an end face 211 facing the electrode body 21 and a recess 3221. The recess 3221 is connected to the end face 211, and the end face 211 abuts against the electrode body 21. In the direction of the end cap assembly 3 pointing to the electrode body 21, the recess 3221 overlaps at least partially with the electrode body 21, or the recess 3221 does not overlap with the electrode body 21.

[0173] In some examples, the insulating film 4 is fused to the wall of the recess 3221 to form multiple connecting portions 5. These multiple connecting portions 5 are spaced apart. This improves the welding stability between the insulating film 4 and the insulating component.

[0174] In these alternative embodiments, the connecting portion 5 is formed within the recess 3221, effectively reducing the additional space occupied by the battery cell and improving energy density and space utilization. Furthermore, the recess 3221 provides an independent accommodating space for the welded connecting portion 5, reducing the risk of wear on the electrode body 21 and enhancing the reliability of the battery cell.

[0175] According to one embodiment of this application, such as Figure 4 and Figure 5 As shown, along the direction perpendicular to the end cap assembly 3 pointing to the electrode body 21, the recess 3221 extends to the edge of the protrusion 322, and at least a portion of the recess 3221 does not overlap with the electrode body 21 in the direction of the end cap assembly 3 pointing to the electrode body 21.

[0176] In some examples, the recess 3221 extends to the edge of the outer periphery of the protrusion 322 along a direction perpendicular to the direction from the end cap assembly 3 to the electrode body 21 and parallel to the first direction x. The first direction x is the length direction of the end cap 31. The end cap 31 is generally rectangular, with a length greater than its width.

[0177] For example, the recess 3221 includes a first surface and a second surface. The first surface is connected to the end face 211 and the second surface of the protrusion 322. The first surface and the second surface are fused with the insulating film 4 to form a connecting portion 5.

[0178] Optionally, the first surface is an arc-shaped surface, and the second surface is an arc-shaped surface.

[0179] In other examples, the recess 3221 extends to the edge of the outer periphery of the protrusion 322 along a direction perpendicular to the direction from the end cap assembly 3 to the electrode body 21 and parallel to the second direction y. The second direction y is the width direction of the end cap assembly 3.

[0180] For example, the recess 3221 includes a third surface and a fourth surface. The third surface is connected to the end face 211 of the protrusion 322 and the fourth surface. The third surface and the fourth surface are fused with the insulating film 4 to form a connecting part 5. The recess 3221 has an L-shaped structure or a similar L-shaped structure.

[0181] Optionally, the first surface is a plane and the second surface is a plane.

[0182] In these alternative embodiments, the electrode body 21 can be retracted into the insulating body 321, which can to some extent retract and fix the electrode body 21, thereby reducing damage to the electrode assembly 2.

[0183] According to one embodiment of this application, such as Figure 4 and Figure 5 As shown, at least a portion of the recess 3221 is arc-shaped.

[0184] Optionally, the recess 3221 is an arc-shaped recess.

[0185] For example, a plurality of connecting portions 5 are provided in the recess 3221.

[0186] In these alternative embodiments, the shape of the recess 3221 matches a portion of the structure of the insulating film 4, so that the two fit and are positioned closely together.

[0187] See also Figure 6 , Figure 6 This is a schematic diagram of the combined structure of the end cap assembly and insulating film of a battery cell provided in an embodiment of this application.

[0188] According to one embodiment of this application, such as Figure 5 and Figure 6 As shown, the insulating component 32 includes a plurality of protrusions 322, which are spaced apart along a first direction x. Each protrusion 322 has at least one recess 3221. The first direction x is perpendicular to the direction from the end cap assembly 3 to the electrode body 21.

[0189] In some examples, the insulating component 32 includes three protrusions 322, two of which are located at both ends of the insulating body 321 and one of which is located in the middle of the insulating body 321, and each protrusion 322 is provided with at least one recess 3221.

[0190] For example, the protrusions 322 at both ends include three recesses 3221, which are spaced apart.

[0191] For example, the protrusion 322 located in the middle includes a recess 3221.

[0192] In these alternative embodiments, this configuration enables large-area, multi-point welding. This improves the strength and reliability of the weld, and also gives the battery cells higher stability and reliability.

[0193] According to one embodiment of this application, such as Figure 5 and Figure 6 As shown, the plurality of protrusions 322 include two first protrusions 322a, which are disposed at both ends of the main body along the first direction x. The wall surface of the recess 3221 of the first protrusion 322a forms a plurality of connecting portions 5 with the insulating film 4. The plurality of connecting portions 5 are spaced apart along the extension direction of the recess 3221, and adjacent connecting portions 5 are connected by the insulating film 4.

[0194] Optionally, the recess 3221 of the first protrusion 322a is arc-shaped.

[0195] For example, the portion of the insulating film 4 covering the outer peripheral surface 212 is rectangular, including two long sides and two short sides. The wall surface of the recess 3221 of the first protrusion 322a forms three connecting portions 5 with the insulating film 4, which are respectively connected to the two long sides and one short side, and adjacent connecting portions 5 are connected through the insulating film 4.

[0196] Optionally, the plurality of protrusions 322 may also include a second protrusion 322b, which is located between the two first protrusions 322a, and the wall surface of the recess 3221 of the second protrusion 322b forms a connection portion 5 with the insulating film 4.

[0197] Alternatively, the recess 3221 of the second protrusion 322b has an L-shaped structure.

[0198] In these alternative embodiments, this arrangement further improves the weld stability between the insulating component 32 and the insulating film 4.

[0199] According to one embodiment of this application, such as Figures 4 to 6As shown, the insulating film 4 includes a first film 41 and a second film 42 connected together. The first film 41 is disposed between the electrode body 21 and the insulating component 32. At least a portion of the first film 41 is fused to the surface of the protrusion 322 opposite to the insulating body 321 to form a connecting portion 5. At least a portion of the second film 42 surrounds the outer peripheral surface 212 and is connected to the outer peripheral surface 212. In the direction of the end cap assembly 3 pointing towards the electrode body 21, the first film 41 has an opening 411, the opening 11 for exposing at least a portion of the electrode assembly 2.

[0200] In some examples, the insulating film 4 includes a first film body 41 and a second film body 42 connected together. The first film body 41 is disposed between the electrode body 21 and the insulating component 32. A portion of the first film body 41 is fused to the wall surface of the recess 3221 to form a plurality of connecting portions 5. At least a portion of the second film body 42 surrounds the outer peripheral surface 212.

[0201] In some examples, the first membrane 41 has an opening 411 for exposing at least a portion of the tabs 22 and end faces 211 of the electrode assembly 2.

[0202] Optionally, the second membrane 42 covers a portion of the electrode body 21.

[0203] Specifically, the electrode body 21 includes an end face 211, an outer peripheral surface 212 and a bottom surface. The end face 211 and the bottom surface are located on both sides of the outer peripheral surface 212. The tab 22 extends from the end face 211, and the second membrane 42 covers the outer peripheral surface 212 and the bottom surface.

[0204] First, the first membrane 41 is fused with the insulating body 321 to form a connection part, then the electrode assembly 2 is connected with the end cap assembly 3, and then the second membrane 42 is wrapped around the electrode body 21.

[0205] In these alternative embodiments, the first membrane 41 is fused to the insulating body 321 to achieve stable installation of the insulating membrane 4, and the second membrane 42 is connected to the outer peripheral surface 212 to reduce the occurrence of insulating membrane 4 detachment. In addition, the insulating membrane 4 can also restrict the isolation membrane located at the outermost ring of the electrode assembly 2, thereby suppressing its thermal expansion and contraction when heated and reducing short circuit points.

[0206] According to one embodiment of this application, such as Figures 4 to 6As shown, the outer peripheral surface 212 includes two straight sections 2121 and two bent sections 2122. The two straight sections 2121 are spaced apart along the second direction y, and the two bent sections 2122 are spaced apart along the first direction x. The bent sections 2122 are connected to the two straight sections 2121. The end cap assembly 3 points to the electrode body 21 in a direction that is perpendicular to both the first direction x and the second direction y. The second membrane 42 includes two first parts 421 and two second parts 422. The two first parts 421 are spaced apart along the first direction x. The first parts 421 are bent relative to the first membrane 41 and connected to the bent sections. The second parts are bent relative to the first membrane 41 and connected to the straight sections 2121. The second parts 422 are connected to the two adjacent first parts 421.

[0207] Optionally, the electrode body 21 has a wound structure, and the outer peripheral surface 212 of the electrode body 21 includes two straight sections 2121 and two bent sections 2122. The two bent sections 2122 are opposite to each other along a first direction x. The two straight sections 2121 are opposite to each other along a second direction y. The straight sections 2121 are the large surface of the electrode body 21. The bent sections 2122 are the side surfaces of the electrode body 21.

[0208] In some examples, the second membrane 42 includes two first portions 421, which are spaced apart along a first direction x. The first portions 421 are bent relative to the first membrane 41 in the direction from the end cap assembly 3 toward the electrode body 21 and connected to the bent section.

[0209] Optionally, the two first parts 421 respectively cover the two bent sections 2122.

[0210] In some examples, the second membrane 42 includes two second portions 422 connected to two adjacent first portions 421. The second portions are bent relative to the first membrane 41 in the direction from the end cap assembly 3 toward the electrode body 21 and connected to the straight section 2121.

[0211] Optionally, the two second parts 422 respectively cover the two straight segments 2121.

[0212] In some examples, the first part 421 and the second part 422 are separate structures.

[0213] In some examples, the connection method of the first part 421 and the second part 422 includes one or more of the following: adhesive bonding, snap-fitting, welding, and connector connection.

[0214] In these alternative embodiments, the two first portions 421 and the two second portions 422 cover the outer peripheral surface 212 of the electrode body 21, providing good shaping and insulation for the electrode body 21.

[0215] According to one embodiment of this application, such as Figures 4 to 6 As shown, the second part 422 includes a first segment 4221 and two second segments 4222. The first segment 4221 is bent relative to the first membrane 41 and connected to the straight segment 2121. The second segment 4222 is bent relative to the first segment 4221 and attached to the first part 421. The two second segments 4222 are disposed at both ends of the first segment 4221 along the first direction x.

[0216] For example, the second segment 4222 is adhered to the first segment 421.

[0217] For example, two second segments 4222 that are attached to the first portion 421 are spaced apart along the second direction y.

[0218] For example, the two second segments 4222 are attached to the first portion 421.

[0219] According to one embodiment of this application, there are multiple connecting parts 5, with at least one connecting part 5 connected to the first part 421 and at least one connecting part 5 connected to the second part 422.

[0220] For example, the second membrane 42 includes two first portions 421 and two second portions 422. The two first portions 421 are spaced apart along a first direction x. The first portions 421 are bent relative to the first membrane 41 and connected to the bent section. The second portions 422 are bent relative to the first membrane 41 and connected to the straight section 2121. The second portions 422 are connected to two adjacent first portions 421. The first portions 421 are connected to one connecting portion 5, and the second portions 422 are connected to three connecting portions 5.

[0221] Optionally, the three connecting parts 5 are spaced apart along the first direction x.

[0222] In these alternative embodiments, multiple connecting portions 5 are connected to the second membrane 42 to improve the overall structural stability of the insulating membrane 4 and reduce the occurrence of the insulating membrane 4 falling off.

[0223] See also Figure 7 and Figure 8 , Figure 7 This is a partial structural schematic diagram of the end cap assembly and insulating film of a battery cell provided in an embodiment of this application; Figure 8 This is a schematic diagram of the end cap assembly and part of the insulating film structure of a battery cell provided in an embodiment of this application.

[0224] According to one embodiment of this application, such as Figure 7 and Figure 8As shown, the second membrane 42 also includes a third part 423, which is connected to the first part 421 and the second part 422. The third part 423 includes a third segment 4231, a fourth segment 4232 and two fifth segments 4233. In the direction from the end cap assembly 3 to the electrode body 21, at least a portion of the third segment 4231 is disposed opposite to the end face 211. The third segment 4231 is bent relative to one of the second parts 422. The fourth segment 4232 is bent relative to the third segment 4231 and fits into another second part 422. The fifth segment 4233 is bent relative to the third segment 4231 and fits into the first part 421. The two fifth segments 4233 are disposed opposite to each other along the first direction x.

[0225] For example, the fourth segment 4232 is adhered to the first segment 421.

[0226] Optionally, the fourth segment 4232 is bonded to the first part 421 and the two second segments 4222.

[0227] In these alternative embodiments, the insulating film 4 is configured to more tightly cover the electrode body 21.

[0228] Secondly, this application provides a battery device including the aforementioned battery cell 10.

[0229] Thirdly, this application provides an electrical device, including the aforementioned battery cell 10 or the aforementioned battery device, wherein the battery cell 10 or the battery device is used to store or provide electrical energy.

[0230] According to some embodiments of this application, such as Figures 2 to 8 As shown, this application provides a battery cell 10, which includes a housing 1, an electrode assembly 2, an end cap assembly 3, and an insulating film 4.

[0231] The housing 1 has an opening 11.

[0232] Electrode assembly 2 is disposed within housing 1. Electrode assembly 2 includes electrode body 21 and tab 22. Electrode body 21 has end face 211 and outer peripheral surface 212. Tab 22 extends from end face 211. Outer peripheral surface 212 includes two straight sections 2121 and two bent sections 2122. The two straight sections 2121 are spaced apart along a second direction y, and the two bent sections 2122 are spaced apart along a first direction x. The bent sections 2122 are connected to the two straight sections 2121. End cap assembly 3 is perpendicular to the direction of electrode body 21, the first direction x, and the second direction y.

[0233] The end cap assembly 3 includes an end cap 31 and an insulating member 32. The end cap 31 closes the opening 11, and the insulating member 32 is disposed on the side of the end cap 31 facing the electrode assembly 2. The insulating member 32 includes an insulating body 321 and a plurality of protrusions 322. The plurality of insulating bodies 321 are attached to the end cap 31. The plurality of protrusions 322 are spaced apart along a first direction x. The protrusions 322 protrude from the surface of the insulating body 321 away from the end cap 31. The protrusions 322 include a recess 3221, which is recessed relative to the surface of the protrusion 322 facing the electrode body 21 and extends to the edge of the protrusion 322 along a direction perpendicular to the direction from the end cap assembly 3 to the electrode body 21. At least a portion of the recess 3221 is arc-shaped.

[0234] An insulating film 4 surrounds the outer peripheral surface 212, and at least a portion of the insulating film 4 is fused to the surface of the insulating component 32 facing away from the end cap 31 to form a connecting portion 5. At least a portion of the wall of the recess 3221 is fused to insulating adhesive to form a plurality of connecting portions 5. The plurality of connecting portions 5 are spaced apart along the extending direction of the recess 3221, and adjacent connecting portions 5 are connected by the insulating film 4. The insulating film 4 includes a first film body 41 and a second film body 42 connected together. The first film body 41 is disposed between the electrode body 21 and the insulating component 32, and at least a portion of the first film body 41 is fused to the surface of the protrusion 322 facing away from the insulating body 321 to form a connecting portion 5. At least a portion of the second film body 42 surrounds the outer peripheral surface 212 and is connected to the outer peripheral surface 212. In the direction from the end cap assembly 3 to the electrode body 21, the first film body 41 has an opening 411, and the opening 11 is used to expose at least a portion of the electrode assembly 2. The second film body 42 includes two first portions 421, two second portions 422, and a third portion 423. Two first portions 421 are spaced apart along a first direction x. The first portion 421 is bent relative to the first membrane 41 and connected to the bent section. The second portion is bent relative to the first membrane 41 and connected to the straight section 2121. The second portion 422 is connected to the two adjacent first portions 421. The second portion 422 includes a first segment 4221 and two second segments 4222. The first segment 4221 is bent relative to the first membrane 41 and connected to the straight section 2121. The second segment 4222 is bent relative to the first segment 4221 and adheres to the first portion 421. The two second segments 4222 are disposed at both ends of the first segment 4221 along the first direction x. The third part 423 is connected to the first part 421 and the second part 422. The third part 423 includes a third segment 4231, a fourth segment 4232 and two fifth segments 4233. In the direction from the end cap assembly 3 to the electrode body 21, at least a portion of the third segment 4231 is disposed opposite to the end face 211. The third segment 4231 is bent relative to one of the second parts 422. The fourth segment 4232 is bent relative to the third segment 4231 and fits into another second part 422. The fifth segment 4233 is bent relative to the third segment 4231 and fits into the first part 421. The two fifth segments 4233 are disposed opposite to each other along the first direction x.

[0235] 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 includes an electrode body and a tab. The electrode body has an end face and an outer peripheral face, and the tab extends from the end face. An end cap assembly includes an end cap and an insulating component, the end cap covering the opening, and the insulating component being disposed on the side of the end cap facing the electrode assembly; An insulating film surrounds the outer peripheral surface, and at least a portion of the insulating film is fused to the surface of the insulating component opposite to the end cap to form a connection. The insulating component includes an insulating body and a protrusion. The insulating body is attached to the end cap, and the protrusion protrudes from the surface of the insulating body away from the end cap. The insulating film is fused to the surface of the protrusion away from the insulating body to form the connecting portion. The insulating film includes a first film and a second film connected together. The first film is disposed between the electrode body and the insulating component. At least a portion of the first film is fused to the surface of the protrusion away from the insulating body to form the connecting portion. At least a portion of the second film surrounds the outer peripheral surface and is connected to the outer peripheral surface and the first film.

2. The battery cell according to claim 1, characterized in that, Along the direction from the end cap assembly toward the electrode body, the insulating film is located on the side of the insulating component facing the electrode body.

3. The battery cell according to claim 1, characterized in that, The protrusion includes a recess that is recessed relative to the surface of the protrusion facing the electrode body, and at least a portion of the wall of the recess is fused to the insulating film.

4. The battery cell according to claim 3, characterized in that, Along a direction perpendicular to the end cap assembly pointing towards the electrode body, the recess extends to the edge of the protrusion, and at least a portion of the recess does not overlap with the electrode body in the direction of the end cap assembly pointing towards the electrode body.

5. The battery cell according to claim 3, characterized in that, At least a portion of the recess is arc-shaped.

6. The battery cell according to claim 3, characterized in that, The insulating component includes a plurality of protrusions, which are spaced apart along a first direction. Each protrusion has at least one recess. The first direction is perpendicular to the direction from which the end cap assembly points to the electrode body.

7. The battery cell according to claim 6, characterized in that, The plurality of protrusions includes two first protrusions, which are disposed at both ends of the main body along a first direction. The wall surface of the recess of the first protrusion forms a plurality of connecting portions with the insulating film. The plurality of connecting portions are spaced apart along the extension direction of the recess, and adjacent connecting portions are connected through the insulating film.

8. The battery cell according to claim 1, characterized in that, In the direction of the end cap assembly toward the electrode body, the first membrane has an opening for exposing at least a portion of the electrode assembly.

9. The battery cell according to claim 8, characterized in that, The outer peripheral surface includes two straight sections and two bent sections. The two straight sections are spaced apart along a second direction, and the two bent sections are spaced apart along a first direction. The bent sections are connected to the two straight sections. The direction in which the end cap assembly points to the electrode body, the first direction, and the second direction are perpendicular to each other. The second membrane includes two first parts and two second parts. The two first parts are spaced apart along the first direction. The first parts are bent relative to the first membrane and connected to the bent section. The second parts are bent relative to the first membrane and connected to the straight section. The second parts are connected to the two adjacent first parts.

10. The battery cell according to claim 9, characterized in that, The second part includes a first segment and two second segments. The first segment is bent relative to the first membrane and connected to the straight segment. The second segment is bent relative to the first segment and attached to the first part. The two second segments are disposed at both ends of the first segment along the first direction.

11. The battery cell according to claim 9, characterized in that, The number of connecting parts is multiple, at least one of the connecting parts is connected to the first part, and at least one of the connecting parts is connected to the second part.

12. The battery cell according to claim 9, characterized in that, The second membrane further includes a third portion connected to the first portion and the second portion. The third portion includes a third segment, a fourth segment, and two fifth segments. In the direction of the end cap assembly pointing towards the electrode body, at least a portion of the third segment is disposed opposite to the end face. The third segment is bent relative to one of the second portions. The fourth segment is bent relative to the third segment and fits into the other second portion. The fifth segment is bent relative to the third segment and fits into the first portion. The two fifth segments are disposed opposite to each other along the first direction.

13. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1 to 12.

14. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1 to 12 or a battery device according to claim 13, wherein the battery cell or the battery device is used to store or provide electrical energy.

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