Battery cells, battery packs and electrical devices

Abstract

This application relates to a battery cell, a battery device, and an electrical device. The battery cell includes a housing, an electrode assembly, an end cap assembly, an insulating film, and a heat insulation component. The housing has an opening. The electrode assembly is disposed within the housing and includes an electrode body and a tab. The end cap assembly includes an end cap and an insulating component. The end cap closes to the opening, and the insulating component is disposed on the side of the end cap facing the electrode body. The insulating film is at least partially located between the electrode body and the housing, and at least a portion of the insulating film is fused to the insulating component to form a connection. The heat insulation component is disposed within the housing and is connected to at least one of the electrode body and the insulating component. At least a portion of the heat insulation component is located on the side of the connection in the direction from the end cap assembly to the electrode body, and protrudes from the electrode body in the direction from the electrode body to the end cap assembly. The battery cell provided by this application has a heat insulation component that can reduce or block heat radiation and heat conduction, reducing the risk of short circuits due to electrode assembly damage.

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, an insulating film, and a heat insulation member. The housing has an opening. The electrode assembly is disposed within the housing and includes an electrode body and a tab. The end cap assembly includes an end cap and an insulating member, the end cap closing onto the opening, and the insulating member being disposed on the side of the end cap facing the electrode body. The insulating film is at least partially located between the electrode body and the housing, and at least a portion of the insulating film is fused to the insulating member to form a connection. The heat insulation member is disposed within the housing and connected to at least one of the electrode body and the insulating member, at least a portion of the heat insulation member being located on the side of the connection in the direction from the end cap assembly to the electrode body, and protruding from the electrode body in the direction from the electrode body to the end cap assembly.

[0006] The battery cell provided in this application incorporates a heat insulation component. At least a portion of the heat insulation component is located on one side of the connection portion in the direction from the end cap assembly to the electrode body, and protrudes from the electrode body in the direction from the electrode body to the end cap assembly. Therefore, the heat insulation component can construct a thermal barrier between the connection portion and the electrode body. During the welding process of the insulating film and insulating components to form the connection portion, it weakens or blocks heat radiation and heat conduction, thereby effectively suppressing the temperature rise of the electrode assembly. Even if the electrode body is close to the welding head during the welding process, the heat insulation component can effectively buffer heat, reducing the possibility of localized overheating and damage to the electrode assembly, thus reducing the risk of short circuits in the battery cell due to electrode assembly damage. Moreover, during the manufacturing process of the battery cell, no large-scale adjustments to existing production equipment are required. The process simply involves adding a connection link between the heat insulation component and at least one of the electrode body and insulating components, making operation simple and convenient. Furthermore, the heat insulation component is not only inexpensive but also reduces the hot-melt defect rate, effectively improving production efficiency and enhancing the reliability of the battery cell.

[0007] According to one embodiment of this application, the electrode body has an end face and an outer peripheral face, an electrode tab extends from the end face, and the outer peripheral face surrounds and is connected to the end face. The heat insulation member includes a first heat insulation portion and a second heat insulation portion. The first heat insulation portion is located between the outer peripheral face and the insulating film, and the second heat insulation portion protrudes from the first heat insulation portion in the direction from the electrode body to the end cap assembly, and at least a portion of the orthographic projection of the second heat insulation portion overlaps with the orthographic projection of the connecting portion.

[0008] In these alternative embodiments, the arrangement such that a portion of the heat insulation element is connected to the electrode body increases the connection stability of the heat insulation element. Furthermore, the heat insulation element can, to a certain extent, prevent the electrode body from facing the connection portion, effectively isolating the connection portion and the electrode body from the insulating membrane.

[0009] According to one embodiment of this application, in the direction from which the electrode body points toward the insulating film, a portion of the second heat insulation portion is located between the insulating component and the insulating film.

[0010] In these alternative embodiments, the first insulating portion is connected to the outer peripheral surface of the electrode body, which can reduce lateral heat conduction, and the second insulating portion is connected to the insulating component, which can reduce the occurrence of insulating member detachment. In addition, the insulating member can also hold the insulating film located at the outermost ring of the electrode assembly, suppressing its shrinkage behavior when heated and reducing short circuit points.

[0011] According to one embodiment of this application, the second heat insulation part is provided with a clearance hole, which is used to avoid the connection part.

[0012] In these alternative embodiments, the second heat insulation portion is disposed around at least a portion of the connection portion, which can more effectively block heat from diffusing to the surroundings. Moreover, the second heat insulation portion can reduce interface cracking caused by thermal stress, thereby improving the stability of the insulating component.

[0013] According to one embodiment of this application, a second heat insulation portion is further disposed between the insulating component and the end cap.

[0014] In these alternative embodiments, this arrangement increases the connection area between the second heat insulation portion and the insulating component, further reducing the occurrence of heat insulation film detachment.

[0015] According to one embodiment of this application, the second heat insulation part includes a first sub-part and a second sub-part. The first sub-part is connected between the second sub-part and the first heat insulation part. In the direction from the electrode body to the insulating film, at least a portion of the first sub-part is located between the insulating component and the insulating film. The first sub-part is provided with a clearance hole. The second sub-part is located between the insulating component and the end cap.

[0016] According to one embodiment of this application, an avoidance hole is also provided in the second sub-part.

[0017] In these alternative embodiments, clearance holes are also provided in the second sub-section. On the one hand, this can reduce the weight of the heat insulation part, which is beneficial to improving the lightweight of the battery cell. On the other hand, clearance holes can form clearance space, which is beneficial to avoid other components in the end cap assembly and reduce the impact on gas flow.

[0018] According to one embodiment of this application, in the direction from which the end cap assembly points toward the electrode body, a portion of the second heat insulation portion is located between the insulating component and the electrode body.

[0019] In these alternative embodiments, the spacer can constrain the outer peripheral surface and end face, which can to some extent form a closing and fixing effect on the electrode body, thereby reducing damage to the electrode assembly.

[0020] According to one embodiment of this application, the outer peripheral surface includes a first surface disposed opposite to each other along a first direction and a second surface disposed opposite to each other along a second direction. The first surface is connected to the two second surfaces, and the second surface is at least partially arc-shaped. The first direction, the second direction, and the direction of the end cap assembly pointing towards the electrode body are perpendicular to each other. A first heat insulation portion is attached to the first surface.

[0021] According to one embodiment of this application, the heat insulation component includes two first heat insulation parts and a second heat insulation part, the two first heat insulation parts are disposed opposite to each other along a first direction, and the second heat insulation part is connected between the two first heat insulation parts.

[0022] In these alternative embodiments, this configuration improves the connection stability of the thermal insulation component and effectively blocks heat, reducing the risk of overheating and damage to the electrode assembly. Furthermore, the thermal insulation component also has a contracting effect on the electrode assembly, suppressing the shrinkage of the insulating membrane and further reducing the risk of short circuits due to lack of insulation protection on the electrode sheets.

[0023] According to one embodiment of this application, the insulating component includes a main body and a protrusion; the main body is attached to an end cap; the protrusion protrudes from the surface of the main body away from the end cap, and a portion of the heat insulation component is located between the protrusion and the insulating film in the direction from which the electrode body points to the insulating film.

[0024] In these alternative embodiments, a portion of the heat insulation element is located between the protrusion and the insulating film to block heat transfer, effectively reducing the risk of short circuits caused by electrode assembly failure.

[0025] According to one embodiment of this application, the insulating component includes a plurality of protrusions, the plurality of protrusions including two first protrusions and a second protrusion, the two first protrusions being disposed at opposite ends of the main body, and the second protrusion being located between the two first protrusions; the battery cell includes a plurality of heat insulation components, the plurality of heat insulation components including two first heat insulation components and a second heat insulation component, in the direction from the electrode body to the insulating film, a portion of the first heat insulation component being located between the first protrusion and the insulating film, and a portion of the second heat insulation component being located between the second protrusion and the insulating film.

[0026] In these alternative embodiments, a portion of the first thermal insulation element is located between the first protrusion and the insulating film, and a portion of the second thermal insulation element is located between the second protrusion and the insulating film, forming a multi-point thermal insulation protection system that can more broadly cover areas where short circuit risks may occur.

[0027] According to one embodiment of this application, the thickness of the thermal insulation element is 0.02 mm to 0.1 mm.

[0028] In these alternative embodiments, the insulation element has a suitable thickness, which can not only meet the insulation effect, but also reduce the amount of insulation element used, which is beneficial to improving the energy density of the battery cell.

[0029] According to one embodiment of this application, in the second direction, the two opposite ends of the heat insulation member protrude from the connecting portion, and the maximum dimension L1 of the heat insulation member and the dimension L2 of the connecting portion satisfy: 4mm≤L1-L2≤15mm, and the second direction is perpendicular to the direction of the end cap assembly pointing to the electrode body.

[0030] In these alternative embodiments, the insulation element is configured such that it has suitable dimensions in the second direction, mitigating the problem of insulation failure caused by deviations in the hot-melt process and the connection of the insulation element to the insulating components if the insulation element is too small. It also mitigates the issue of insulation failure caused by excessive coverage of the electrode assembly if the insulation element is too large, which is detrimental to electrolyte wetting.

[0031] Secondly, this application provides a battery device including the aforementioned battery cell.

[0032] According to one embodiment of this application, the insulating component is located on the underside of the electrode assembly.

[0033] 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.

[0034] 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

[0035] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0036] Figure 1 This is a schematic diagram of the structure of a vehicle provided in one embodiment of this application;

[0037] Figure 2 This is an exploded view of a battery device provided in an embodiment of this application;

[0038] Figure 3 This is an exploded view of a single battery cell provided in an embodiment of this application;

[0039] Figure 4 This is a partial exploded view of a battery cell provided in one embodiment of this application;

[0040] Figure 5 This is a partial structural schematic diagram of a battery cell provided in an embodiment of this application;

[0041] Figure 6 This is a partial structural schematic diagram of a battery cell provided in another embodiment of this application;

[0042] Figure 7 This is a partial front view of a battery cell provided in an embodiment of this application;

[0043] Figure 8 for Figure 7 A magnified structural schematic diagram at point a of some embodiments shown;

[0044] Figure 9 This is a schematic diagram of the end cap assembly and heat insulation film of a battery cell provided in an embodiment of this application;

[0045] Figure 10 This is a partial front view of a battery cell provided in another embodiment of this application.

[0046] The accompanying drawings may not be drawn to scale.

[0047] Explanation of reference numerals in the attached figures:

[0048] 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, First surface; 2122, Second surface; 22, Tab; 3, End cap assembly; 31, End cap; 32, Insulating component; 321, Main body; 322, Protrusion; 322a, First protrusion; 322b, Second protrusion; 4, Insulating film; 41, Connecting part; 5, Heat insulation component; 5a, First heat insulation component; 5b, Second heat insulation component; 51, First heat insulation part; 52, Second heat insulation part; 521, First sub-part; 522, Second sub-part; 53, Clearance hole; x, First direction; y, Second direction. Detailed Implementation

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] In this application, "multiple" means two or more (including two).

[0056] 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.

[0057] 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.

[0058] In the thermal fusion bonding process of the insulating film of a battery cell, the high temperature of the welding head or positioning deviation can easily burn the outermost separator film of the electrode assembly. This is especially true for the insulating components in the end cap assembly, which are relatively short. This means that the size of the insulating component is small in the direction from the end cap assembly to the electrode body. Damage to the separator film can lead to internal short circuits in the electrode assembly, and even thermal runaway, severely affecting product yield and reliability. The above statements are for providing background information related to this application only and do not necessarily constitute prior art.

[0059] The battery cell provided in this application incorporates a heat insulation component. At least a portion of the heat insulation component is located on one side of the connection portion in the direction from the end cap assembly to the electrode body, and protrudes from the electrode body in the direction from the electrode body to the end cap assembly. Therefore, the heat insulation component can construct a thermal barrier between the connection portion and the electrode body. During the process of fusing the insulating film and insulating components to form the connection portion, it weakens or blocks heat radiation and heat conduction, thereby effectively suppressing the temperature rise of the electrode assembly. Even if the electrode body is close to the welding head during the fusion process, the heat insulation component can effectively buffer heat, reducing the possibility of localized overheating and damage to the electrode assembly, thereby reducing the risk of short circuits in the battery cell due to electrode assembly damage.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] Please refer to Figure 2, Figure 2 An exploded view of a battery device 100 provided in some embodiments of this application.

[0064] In some embodiments, the battery device 100 may include one or more battery cell assemblies for providing voltage and capacity.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] In some embodiments, the housing is used to house individual battery cells, and the housing can have various structures.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] In some embodiments, the battery device 100 may be an energy storage device.

[0076] 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.

[0077] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0078] 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.

[0079] 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.

[0080] This application provides a battery cell that includes a housing and an electrode assembly housed within the housing.

[0081] 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).

[0082] The outer shell may be a hollow structure, with an internal cavity 20b for accommodating the electrode assembly and electrolyte.

[0083] 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.

[0084] 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;

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] The end caps are attached to the housing by welding, bonding, snap-fitting, or other means.

[0090] 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.

[0091] Electrode assemblies are the components within a single battery cell where electrochemical reactions occur. The casing may contain one or more electrode assemblies.

[0092] 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.

[0093] At least a portion of the separator is located between the positive and negative electrode plates. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative 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.

[0094] 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.

[0095] 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.

[0096] 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.).

[0097] 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) 523LiNi 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.

[0098] In some embodiments, the negative electrode may include a negative current collector.

[0099] 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 base layer 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.).

[0100] 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.

[0101] 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.

[0102] 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.

[0103] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0104] 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.

[0105] 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.

[0106] Inorganic particle coating, organic particle coating, or organic / inorganic composite coating can also be applied to the surface of the separator.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0116] 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.

[0117] 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.

[0118] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0119] In some embodiments, the electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0120] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0121] In some implementations, the electrode assembly is a stacked structure.

[0122] 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.

[0123] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0124] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0125] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0126] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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 partial structural schematic diagram of a battery cell provided in an embodiment of this application.

[0133] 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, an insulating film 4, and a heat insulation member 5. The housing 1 has an opening 11. The electrode assembly 2 is disposed on the housing 1 and includes an electrode body 21 and a tab 22. The end cap assembly 3 includes an end cap 31 and an insulating member 32. The end cap 31 closes to the opening 11, and the insulating member 32 is disposed on the side of the end cap 31 facing the electrode body 21. The insulating film 4 is at least partially located between the electrode body 21 and the housing 1, and at least a portion of the insulating film 4 is fused to the insulating member 32 to form a connection portion 41. The heat insulation member 5 is disposed inside the housing 1 and is connected to at least one of the electrode body 21 and the insulating member 32. At least a portion of the heat insulation member 5 is located on the side of the connection portion 41 in the direction of the end cap assembly 3 pointing towards the electrode body 21, and protrudes from the electrode body 21 in the direction of the electrode body 21 pointing towards the end cap assembly 3.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] Electrode assembly 2 includes electrode body 21. The portions of the positive and negative electrode plates containing active materials constitute the electrode body 21.

[0140] 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.

[0141] The electrode assembly 2 also includes tabs 22. Tabs 22 extend from the electrode body 21. The portions of the positive and negative electrodes that do not contain active material each constitute tabs 22.

[0142] In some examples, the tab 22 extends from one end of the electrode body 21.

[0143] In other examples, tabs 22 extend from opposite ends of electrode body 21.

[0144] In some examples, the tab 22 can be a positive tab 22 and at least partially protrude to the outside of the electrode body 21.

[0145] In other examples, the tab 22 may be a negative tab 22 and may protrude at least partially outward from the electrode body 21.

[0146] 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.

[0147] In some examples, the insulating component 32 is made of an insulating material, such as plastic or PVC.

[0148] For example, the insulating component 32 and the end cap 31 can be connected by means of adhesive, snap-fit ​​or threaded connection.

[0149] The insulating film 4 is at least partially 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.

[0150] Specifically, the insulating film 4 covers the outer surface of the electrode assembly 2.

[0151] In some examples, the insulating film 4 can be a sheet material or a film material.

[0152] In some examples, the insulating film 4 can be a soft material or a hard material.

[0153] In some examples, the part can be made of plastic, silicone, or other plastic materials.

[0154] 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, thereby connecting with the insulating component 32.

[0155] At least a portion of the insulating film 4 is fused to the insulating component 32 to form a connecting portion 41. This can be understood as the connecting portion 41 being the part where the outer peripheral surface 212 of the insulating component 32 and the insulating film 4 are connected to each other.

[0156] 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.

[0157] In some examples, the heat insulation element 5 is connected to the outer surface of the electrode body 21; or, the heat insulation element 5 is connected to the outer surface of the insulating component 32; or, the heat insulation element 5 is connected to both the outer surface of the electrode body 21 and the outer surface of the insulating component 32.

[0158] At least a portion of the heat insulation member 5 is located on one side of the connecting portion 41 in the direction from the end cap assembly 3 to the electrode body 21. This can be understood as at least a portion of the heat insulation member 5 being located on the side of the connecting portion 41 closer to the electrode body 21. Furthermore, it protrudes from the electrode body 21 in the direction from the end cap assembly 3.

[0159] For example, in the direction from the end cap assembly 3 to the electrode body 21, the heat insulation member 5 is located between the end cap assembly 3 and the electrode body 21.

[0160] For example, in the direction from the end cap assembly 3 to the electrode body 21, a portion of the heat insulation member 5 is located between the end cap assembly 3 and the electrode body 21, and another portion is disposed on the outer peripheral surface 212 of the electrode body 21.

[0161] For example, in the direction from the end cap assembly 3 to the electrode body 21, a portion of the heat insulation member 5 is located between the end cap assembly 3 and the electrode body 21, and another portion is disposed on the outer surface of the insulating member 32 where the connecting portion 41 is located.

[0162] For example, the heat insulation element 5 includes at least one of a heat insulation board, a heat insulation sheet, or a heat insulation film.

[0163] In some examples, the material of the insulation element 5 is selected from at least one of polyimide, ceramic fiber, and polyethylene terephthalate.

[0164] In some examples, the insulation element 5 satisfies the following condition: after one side surface of the insulation pad is in contact with the hot surface at 240°C for 1.5 seconds, the temperature of the other side surface of the insulation element 5 opposite to one side surface is less than or equal to 70°C. This setting ensures that the insulation element 5 is not subject to thermal shrinkage.

[0165] In some examples, the thermal insulation 51 has an average peel strength of 0.1 N / mm at 80°, which improves the probability of the insulation lifting when it adheres to at least one of the electrode body 21 and the insulating component 32.

[0166] The battery cell 10 provided in this application incorporates a heat insulation component 5. At least a portion of the heat insulation component 5 is located on one side of the connecting portion 41 in the direction from the end cap assembly 3 to the electrode body 21, and protrudes from the electrode body 21 in the direction from the end cap assembly 3. Therefore, the heat insulation component 5 can construct a thermal barrier between the connecting portion 41 and the electrode body 21. During the process of fusing the insulating film 4 and the insulating component 32 to form the connecting portion 41, it weakens or blocks heat radiation and heat conduction, thereby effectively suppressing the temperature rise of the electrode assembly 2. Even if the electrode body 21 is close to the welding head during the fusing process, the heat insulation component 5 can effectively buffer heat, reducing the possibility of local overheating and damage to the electrode assembly 2, thereby reducing the risk of short circuit in the battery cell due to damage to the electrode assembly 2. Moreover, during the manufacturing process of the battery cell, there is no need for large-scale adjustments to existing production equipment. The connection link between the heat insulation component 5 and at least one of the electrode body 21 and the insulating component 32 is provided in the production process, making the operation simple and convenient. In addition, the heat insulation component 5 is not only inexpensive, but also reduces the hot melt defect rate, effectively improves production efficiency, and enhances the reliability of battery cells.

[0167] According to one embodiment of this application, such as Figure 3 and Figure 4As shown, the electrode body 21 has an end face 211 and an outer peripheral face 212. The electrode tab 22 extends from the end face 211, and the outer peripheral face 212 is disposed around the end face 211 and connected to the end face 211. The heat insulation member 5 includes a first heat insulation part 51 and a second heat insulation part 52. The first heat insulation part 51 is located between the outer peripheral face 212 and the insulating film 4. The second heat insulation part 52 protrudes from the first heat insulation part 51 in the direction from the electrode body 21 to the end cap assembly 3, and at least a portion of the orthographic projection of the second heat insulation part 52 overlaps with the orthographic projection of the connecting part 41.

[0168] 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.

[0169] In some examples, the electrode assembly 2 is a wound structure formed by winding a positive electrode, a separator, and a negative electrode, with the outer peripheral surface 212 being the outermost ring of the electrode assembly 2. The outermost ring is a separator.

[0170] In some examples, the heat insulation member 5 includes a first heat insulation portion 51 and a second heat insulation portion 52, with the first heat insulation portion 51 connected to the second heat insulation portion 52. The first heat insulation portion 51 is located between the outer peripheral surface 212 and the insulating film 4. In the direction from the electrode body 21 to the end cap assembly 3, the second heat insulation portion 52 protrudes from the first heat insulation portion 51 and does not exceed the end face 211 of the insulating member 3 pointing from the end cap assembly 3 to the electrode body 21. At least a portion of the orthographic projection of the second heat insulation portion 52 overlaps with the orthographic projection of the connecting portion 41.

[0171] Optionally, the first heat insulation part 51 is bonded to the outer peripheral surface 212.

[0172] In other examples, the heat insulation member 5 includes a first heat insulation portion 51 and a second heat insulation portion 52, with the first heat insulation portion 51 connected to the second heat insulation portion 52. The first heat insulation portion 51 is located between the outer peripheral surface 212 and the insulating film 4. In the direction from the electrode body 21 to the end cap assembly 3, the second heat insulation portion 52 protrudes from the first heat insulation portion 51 and extends beyond the insulating member 32 along the end face 211 of the end cap assembly 3 pointing towards the electrode body 21. At least a portion of the orthographic projection of the second heat insulation portion 52 overlaps with the orthographic projection of the connecting portion 41.

[0173] Optionally, the first heat insulation part 51 is bonded to the outer peripheral surface 212; the second heat insulation part 52 is bonded to the outer surface of the insulating component 32.

[0174] In these alternative embodiments, the heat insulation member 5 is configured such that a portion of it is connected to the electrode body 21, thereby increasing the connection stability of the heat insulation member 5. Furthermore, the heat insulation member 5 can, to a certain extent, prevent the electrode body 21 from moving toward the connection portion 41, effectively isolating the connection portion 41 and the insulating film of the electrode body 21.

[0175] According to one embodiment of this application, the first heat insulation portion 51 has a size of 10 mm to 20 mm in the direction from the electrode body 21 to the insulating film 4.

[0176] In some examples, the dimensions of the first heat insulation portion 51 in the direction from the electrode body 21 to the insulating film 4 are 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, or other ranges consisting of any two of the above endpoints.

[0177] In these alternative embodiments, the first heat insulation portion 51 has a suitable size, which can mitigate the risk of reduced connection strength and easy lifting or detachment if the size of the first heat insulation portion 51 is too small. It can also mitigate the negative impact of using too many heat insulation components 5 if the size of the first heat insulation portion 51 is too large, as this would hinder the lightweighting of the battery cell.

[0178] See also Figures 6 to 8 , Figure 6 This is a partial structural schematic diagram of a battery cell provided in another embodiment of this application; Figure 7 This is a partial front view of a battery cell provided in an embodiment of this application; Figure 8 for Figure 7 The diagram shows an enlarged structural schematic at point a for some embodiments.

[0179] According to one embodiment of this application, such as Figures 6 to 8 As shown, in the direction from the electrode body 21 to the insulating film 4, a portion of the second heat insulation part 52 is located between the insulating member 32 and the insulating film 4.

[0180] In some examples, in the direction from the electrode body 21 to the insulating film 4, the insulating member 32 protrudes from the outer peripheral surface 212, and the second heat insulation portion 52 includes a first segment and a second segment. The first segment connects the second segment and the first heat insulation portion 51, and the first segment connects the surface of the insulating member 32 facing the electrode body 21. In the direction from the electrode body 21 to the insulating film 4, the second segment is located between the insulating member 32 and the insulating film 4.

[0181] For example, the second segment is connected to the edge of the first segment and bent toward the end cap assembly 3, and the second segment is bonded to the outer surface of the insulating member 32.

[0182] In some examples, in the direction from the electrode body 21 to the insulating film 4, the outer peripheral surface 212 protrudes from the insulating member 32, and the second heat insulation portion 52 includes a first segment and a second segment. The first segment connects the second segment and the first heat insulation portion 51, and the first segment connects to the end face 211. In the direction from the electrode body 21 to the insulating film 4, the second segment is located between the insulating member 32 and the insulating film 4.

[0183] For example, the second segment is connected to the edge of the first segment and bent toward the end cap assembly 3, and the second segment is bonded to the outer surface of the insulating member 32.

[0184] In these alternative embodiments, the first insulating portion is connected to the outer peripheral surface 212 of the electrode body 21, which can reduce lateral heat conduction, and the second insulating portion is connected to the insulating component 32, which can reduce the occurrence of heat insulation component 5 detachment. In addition, the heat insulation component 5 can also hold the insulating film located at the outermost ring of the electrode assembly 2, suppressing its shrinkage behavior when heated and reducing short circuit points.

[0185] According to one embodiment of this application, such as Figures 6 to 8 As shown, the second heat insulation part 52 is provided with a clearance hole 53, which is used to avoid the connection part 41.

[0186] In some examples, a portion of the second heat insulation portion 52 is disposed around the connecting portion 41, and a portion of the second heat insulation portion 52 forms a clearance hole 53.

[0187] For example, the insulating component 32 has a fusion surface, a portion of which is thermally fused to the insulating film 4 to form a connection portion 41, and another portion of which is connected to the second heat insulation portion 52.

[0188] Optionally, the opening shape of the clearance hole 53 is one of rectangle, ellipse, triangle, or trapezoid.

[0189] Optionally, the opening shape of the clearance hole 53 matches the structure of the connecting part 41.

[0190] For example, the connecting part 41 has a rectangular structure, and correspondingly, the opening shape of the clearance hole 53 is rectangular.

[0191] In these alternative embodiments, the second heat insulation portion 52 is disposed around at least a portion of the connecting portion 41, which can more effectively block heat from spreading to the surroundings. Moreover, the second heat insulation portion 52 can reduce interface cracking caused by thermal stress, thereby improving the stability of the insulating component 32.

[0192] According to one embodiment of this application, such as Figure 7 and Figure 8 As shown, the second heat insulation part 52 is also disposed between the insulating part 32 and the end cap 31.

[0193] In some examples, the insulating member 32 has a side surface and a top surface, with the top surface facing the end cap 31 in the direction from the electrode body 21 to the end cap assembly 3, and the side surface surrounding the top surface. A portion of the second heat insulation part 52 is attached to the side surface and has a clearance hole 53, while another portion of the second heat insulation part 52 is attached to the top surface.

[0194] In these alternative embodiments, this arrangement increases the connection area between the second heat insulation portion 52 and the insulating component 32, further reducing the occurrence of heat insulation film detachment.

[0195] See also Figure 9 , Figure 9 This is a schematic diagram of the end cap assembly and heat insulation film of a battery cell provided in an embodiment of this application.

[0196] According to one embodiment of this application, such as Figure 7 and Figure 9 As shown, the second heat insulation part 52 includes a first sub-part 521 and a second sub-part 522. The first sub-part 521 is connected between the second sub-part 522 and the first heat insulation part 51. In the direction from the electrode body 21 to the insulating film 4, at least a portion of the first sub-part 521 is located between the insulating member 32 and the insulating film 4. The first sub-part 521 is provided with a clearance hole 53. The second sub-part 522 is located between the insulating member 32 and the end cap 31.

[0197] For example, the second heat insulation part 52 includes a first sub-part 521 and a second sub-part 522. The first sub-part 521 has a first end and a second end. The first end is connected to the first heat insulation part 51. One end of the second sub-part 522 is connected to the second end and is bent in a direction perpendicular to the electrode body 21 and pointing to the end cap 31.

[0198] Optionally, the other end of the second sub-part 522 extends along the first direction x on the insulating member 32.

[0199] According to one embodiment of this application, such as Figure 7 and Figure 9 As shown, the clearance hole 53 is also provided in the second sub-part 522.

[0200] In some examples, a portion of the clearance hole 53 is located in the first sub-part 521 and another portion is located in the second sub-part 522, and extends along the extension direction of the second sub-part 522.

[0201] For example, the second sub-part 522 extends along the first direction x to both ends of the insulating member 32.

[0202] In these alternative embodiments, the clearance hole 53 is also provided in the second sub-part 522. On the one hand, it can reduce the weight of the heat insulation part, which is beneficial to improving the lightweight of the battery cell. On the other hand, the clearance hole 53 can form a clearance space, which is beneficial to avoid other components in the end cap assembly 3 and reduce the impact on gas flow.

[0203] According to one embodiment of this application, such as Figure 4 and Figure 5 As shown, in the direction from the end cap assembly 3 to the electrode body 21, a portion of the second heat insulation portion 52 is located between the insulating member 32 and the electrode body 21.

[0204] When a battery cell is inverted, the separator of the electrode assembly 2 may shift or sag during the hot-melt connection process due to incomplete fixation, causing it to come into contact with the hot-melt surface of the welding head or insulating component 32. Therefore, by connecting the first part of the heat insulation component 5 to the outer peripheral surface 212 of the electrode body 21 and the second part located between the insulating component 32 and the electrode body 21, the electrode body 21 can be constrained, reducing the displacement of the separator during the hot-melt process, keeping the separator in a safe position, and reducing the contact between the separator and the high-temperature welding head.

[0205] For example, one end of the second heat insulation part 52 is connected to the first heat insulation part 51 and bent in a direction perpendicular to the electrode body 21 toward the end cap 31.

[0206] In these alternative embodiments, the spacer can constrain the outer peripheral surface 212 and the end surface 211, which can to some extent form a closing and fixing effect on the electrode body 21, thereby reducing damage to the electrode assembly 2.

[0207] According to one embodiment of this application, such as Figure 4 As shown, the outer peripheral surface 212 includes a first surface 2121 disposed opposite to each other along a first direction x and a second surface 2122 disposed opposite to each other along a second direction y. The first surface 2121 is connected to the two second surfaces 2122. The second surfaces 2122 are at least partially arc-shaped. The first direction x, the second direction y, and the direction in which the end cap assembly 3 points to the electrode body 21 are perpendicular to each other. The first heat insulation part 51 is attached to the first surface 2121.

[0208] Optionally, the area of ​​the first surface 2121 is larger than the area of ​​the second surface 2122.

[0209] For example, the outer peripheral surface 212 includes two flat surfaces arranged opposite each other along a first direction x and two arcuate surfaces arranged opposite each other along a second direction y. The arcuate surfaces connect two adjacent flat surfaces. The second direction y is perpendicular to the first direction x. The area of ​​the arcuate surfaces is smaller than the area of ​​the flat surfaces. The first heat insulation part 51 is attached to the flat surfaces.

[0210] Optionally, the first heat insulation portion 51 is attached to the first surface 2121 and extends in a direction away from the end face 211.

[0211] According to one embodiment of this application, such as Figure 4 and Figure 9 As shown, the heat insulation component 5 includes two first heat insulation parts 51 and a second heat insulation part 52. The two first heat insulation parts 51 are arranged opposite each other along the first direction x, and the second heat insulation part 52 is connected between the two first heat insulation parts 51.

[0212] In some examples, the heat insulation member 5 includes two first heat insulation portions 51 and a second heat insulation portion 52. The two first heat insulation portions 51 are arranged opposite each other along a first direction x. In the direction from the insulating member 32 to the electrode body 21, a portion of the second heat insulation portion 52 is located between the insulating member 32 and the electrode body 21, and the second heat insulation portion 52 is connected between the two first heat insulation portions 51.

[0213] In other examples, the heat insulation component 5 includes two first heat insulation portions 51 and a second heat insulation portion 52. The two first heat insulation portions 51 are arranged opposite each other along a first direction x. The second heat insulation portion 52 includes two first sub-parts 521 and a second sub-part 522. The first sub-part 521 is connected between the second sub-part 522 and the first heat insulation portion 51. In the direction from the electrode body 21 to the insulating film 4, the first sub-part 521 is located between the insulating component 32 and the insulating film 4. The first sub-part 521 is provided with a clearance hole 53. The second sub-part 522 is located between the insulating component 32 and the end cap 31 and connects the two first sub-parts 521.

[0214] Optionally, the thermal insulation element 5 has an n-shaped structure.

[0215] In these alternative embodiments, this configuration improves the connection stability of the heat insulation element 5 and effectively blocks heat, reducing the risk of overheating and damage to the electrode assembly 2. Furthermore, it provides a contracting effect on the electrode assembly 2, suppressing the shrinkage of the insulating membrane and further reducing the risk of short circuits due to lack of insulation protection on the electrode sheets.

[0216] According to one embodiment of this application, the electrode body 21 includes a first electrode body, and the electrode tab 22 includes a first electrode tab. The first electrode body includes a base portion and a thinned portion, the thinned portion being connected between the base portion and the first electrode tab, and at least a portion of the thickness of the thinned portion being less than the thickness of the base portion. In the thickness direction of the first electrode body, the portion of the first heat insulation portion 51 attached to the outer peripheral surface 212 at least partially overlaps with the thinned portion.

[0217] When the first heat insulation portion 51 is attached to the outer peripheral surface 212, the first heat insulation portion 51 overlaps at least partially with the thinned portion in the thickness direction of the first electrode body.

[0218] The first electrode may include a current collector and an active material layer disposed on at least one surface of the current collector. The portion having the active material constitutes the main body of the first electrode, and the portion without the active material constitutes the tab 22. The tabs 22 may be located together at one end of the main body of the first electrode or separately at both ends of the main body of the first electrode. The thickness of the active material layer varies in different regions. Typically, the thickness of the active material layer at the ends is less than the thickness of the active material layer in the middle. Therefore, the main body of the first electrode includes a base portion and a thinned portion, both of which have an active material layer. The thickness of the active material layer in the thinned portion is less than the thickness of the active material layer in the base portion.

[0219] In some examples, electrode body 21 further includes a second electrode body and a separator, and electrode tab 22 further includes a second electrode tab. The second electrode body includes a second base portion and a second thinned portion, the second thinned portion being connected between the second base portion and the second electrode tab, and at least a portion of the thickness of the second thinned portion being less than the thickness of the second base portion. The separator is disposed at least between the first electrode body and the second electrode body. The first electrode body and the second electrode body have opposite polarities.

[0220] In some examples, the first electrode body may include a negative electrode current collector and a layer of negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0221] In other examples, the first electrode body may include a positive current collector and a layer of positive active material disposed on at least one surface of the positive current collector.

[0222] In the thickness direction of the first electrode body, the first heat insulation portion 51 and the thinning portion at least partially overlap. This can be understood as the first heat insulation portion 51 and the thinning portion being at least partially opposite to each other in the thickness direction.

[0223] In some examples, the first heat insulation portion 51 is attached to the outer peripheral surface 212 of the electrode body 21, and a portion of the first heat insulation portion 51 overlaps with the thinned portion in the thickness direction of the first electrode body.

[0224] In other examples, the first heat insulation portion 51 is attached to the outer peripheral surface 212 of the electrode body 21, and in the thickness direction of the first electrode body, the first heat insulation portion 51 overlaps only with the thinned portion.

[0225] In these alternative embodiments, due to the presence of the thinned portion and the uneven distribution of expansion and contraction forces during long-term use of the electrode assembly 2, there is a defect in the poor adhesion between the separator and the first electrode. Therefore, by attaching the first heat insulation portion 51 to the outer peripheral surface 212 of the electrode body 21 and at least partially overlapping the thinned portion, not only can the rate at which external heat is transferred to this area be slowed down, but the shrinkage of the separator can also be suppressed, further reducing the risk of short circuit due to lack of insulation protection of the electrode.

[0226] According to one embodiment of this application, such as Figure 9 As shown, the insulating component 32 includes a main body 321 and a protrusion 322. The main body 321 is attached to the end cap 31. The protrusion 322 protrudes from the surface of the main body 321 away from the end cap 31. In the direction from the electrode body 21 to the insulating film 4, a portion of the heat insulation component 5 is located between the protrusion 322 and the insulating film 4.

[0227] The insulating component 32 may include one protrusion 322 or multiple protrusions 322, with the multiple protrusions 322 spaced apart on the main body 321.

[0228] The main body 321 and the end cap 31 are stacked together along the thickness direction. The protrusion 322 protrudes from the surface of the main body 321 away from the end cap 31, and the end of the protrusion 322 away from the main body 321 can directly press against the electrode body 21; it can also press against the electrode body 21 through the heat insulation member 5.

[0229] In some examples, a protrusion 322 is provided at the end of the main body portion 321.

[0230] In other examples, a protrusion 322 is provided in the middle of the main body portion 321.

[0231] In these alternative embodiments, a portion of the heat insulation element 5 is located between the protrusion 322 and the insulating film 4 to block heat transfer and effectively reduce the risk of short circuits caused by damage to the electrode assembly 2.

[0232] See conclusion Figure 10 , Figure 10 This is a partial front view of a battery cell provided in another embodiment of this application.

[0233] According to one embodiment of this application, such as Figure 10 As shown, the insulating component 32 includes a plurality of protrusions 322, the plurality of protrusions 322 including two first protrusions 322a and a second protrusion 322b. The two first protrusions 322a are disposed at opposite ends of the main body 321, and the second protrusion 322b is located between the two first protrusions 322a. The battery cell includes a plurality of heat insulation components 5, the plurality of heat insulation components 5 including two first heat insulation components 5a and a second heat insulation component 5b. In the direction from the electrode body 21 to the insulating film 4, a portion of the first heat insulation component 5a is located between the first protrusion 322a and the insulating film 4, and a portion of the second heat insulation component 5b is located between the second protrusion 322b and the insulating film 4.

[0234] For example, the plurality of protrusions 322 include two first protrusions 322a and a second protrusion 322b. The two first protrusions 322a are disposed at opposite ends of the main body portion 321, and the second protrusion 322b is located between the two first protrusions 322a. The battery cell includes a plurality of heat insulation members 5, which include a first insulating member 5a and a second heat insulation member 5b. In the direction from the electrode body 21 to the insulating film 4, a portion of the first insulating member 5a overlaps with a portion of the first protrusion 322a, and a portion of the second heat insulation member 5b overlaps with a portion of the second protrusion 322b.

[0235] Optionally, the first protrusion 322a and the second protrusion 322b have different structures.

[0236] In these alternative embodiments, a portion of the first heat insulation member 5a is located between the first protrusion 322a and the insulating film 4, and a portion of the second heat insulation member 5b is located between the second protrusion 322b and the insulating film 4, forming a multi-point heat insulation protection system that can more broadly cover areas where short circuit risks may occur.

[0237] According to one embodiment of this application, the thickness of the heat insulation element 5 is 0.02 mm to 0.1 mm.

[0238] In some examples, the thickness of the insulation element 5 is 0.02 mm, 0.025 mm, 0.03 mm, 0.035 mm, 0.04 mm, 0.045 mm, 0.05 mm, 0.055 mm, 0.06 mm, 0.065 mm, 0.07 mm, 0.075 mm, 0.08 mm, 0.085 mm, 0.09 mm, 0.095 mm, 0.1 mm, or other ranges formed by any two of the above endpoints.

[0239] Optionally, the thickness of the insulation element 5 is 0.05 mm to 0.08 mm.

[0240] In these alternative embodiments, the heat insulation element 5 has a suitable thickness, which can not only meet the heat insulation effect, but also reduce the use of the heat insulation element 5, which is beneficial to improving the energy density of the battery cell.

[0241] According to one embodiment of this application, in the second direction y, the two opposite ends of the heat insulation member 5 protrude from the connecting portion 41, and the maximum dimension L1 of the heat insulation member 5 and the dimension L2 of the connecting portion 41 satisfy: 4mm≤L1-L2≤15mm, and the second direction y is perpendicular to the direction of the end cap assembly 3 pointing to the electrode body 21.

[0242] In some examples, in the second direction y, the maximum dimension L1 of the heat insulation member 5 and the dimension L1-L2 of the connecting part 41 are 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5.0mm, 5.1mm, 5.2mm, 5.3mm, 5.4mm, 5.5mm, 5.6mm, 5.7mm, 5.8mm, 5.9mm, 6.0mm, 6.1mm, 6.2mm, 6.3mm, 6.4mm, and 6. 5mm, 6.6mm, 6.7mm, 6.8mm, 6.9mm, 7.0mm, 7.1mm, 7.2mm, 7.3mm, 7.4mm, 7.5mm, 7.6mm, 7.7mm, 7.8mm, 7.9mm, 8.0mm, 8.1 mm, 8.2mm, 8.3mm, 8.4mm, 8.5mm, 8.6mm, 8.7mm, 8.8mm, 8.9mm, 9.0mm, 9.1mm, 9.2mm, 9.3mm, 9.4mm, 9.5mm, 9.6mm, 9.7mm , 9.8mm, 9.9mm, 10.0mm, 10.1mm, 10.2mm, 10.3mm, 10.4mm, 10.5mm, 10.6mm, 10.7mm, 10.8mm, 10.9mm, 11.0mm, 11.1mm, 11.2mm, 11.3mm, 11.4mm, 11.5mm, 11.6mm, 11.7mm, 11.8mm, 11.9mm, 12.0mm, 12.1mm, 12.2mm, 12.3mm, 12.4mm, 12.5mm, 12.6mm, 12.7mm, 12.8mm, 12.9mm, 13.0mm, 13.1mm, 13.2mm, 13.3mm, 13.4mm, 13.5mm, 13.6mm, 13.7mm, 13.8mm, 13.9mm, 14.0mm, 14.1mm, 14.2mm, 14.3mm, 14.4mm, 14.5mm, 14.6mm, 14.7mm, 14.8mm, 14.9mm, 15.0mm, or any other range consisting of any two of the above endpoints.

[0243] Optionally, in the second direction y, the dimension of the connecting portion 41 is less than or equal to 10 mm. This satisfies the function of heat fusion fixing.

[0244] In these alternative embodiments, the heat insulation element 5 is configured such that it has a suitable size in the second direction y, thus mitigating the defect that if the size of the heat insulation element 5 is small, deviations in the hot-melt process and the connection between the heat insulation element 5 and the insulating component 32 may lead to heat insulation failure. It also mitigates the defect that if the size of the heat insulation element 5 is large, it may cover too much area of ​​the electrode assembly 2, hindering electrolyte wetting.

[0245] In some examples, the maximum thickness of the insulating component 32 is 1.5 mm to 5 mm in the direction from the electrode body 21 to the end cap assembly 3.

[0246] Optionally, in the direction from the electrode body 21 to the end cap assembly 3, the maximum thickness of the insulating component 32 is 1.5 mm to 3 mm.

[0247] Alternatively, in the direction from the electrode body 21 to the end cap assembly 3, the maximum thickness of the insulating component 32 is 2 mm to 2.5 mm.

[0248] Secondly, this application provides a battery device, including the aforementioned battery cell 10.

[0249] 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.

[0250] According to some embodiments of this application, see Figure 3 , Figures 7 to 9 This application provides a battery cell 10, which includes a housing 1, an electrode assembly 2, an end cap assembly 3, an insulating film 4, and a heat insulation component 5.

[0251] The housing 1 has an opening 11.

[0252] Electrode assembly 2 is disposed on housing 1. Electrode assembly 2 includes electrode body 21 and electrode tab 22. Electrode body 21 has end face 211 and outer peripheral face 212. Electrode tab 22 extends from end face 211. Outer peripheral face 212 surrounds end face 211 and is connected to end face 211. Outer peripheral face 212 includes a first surface 2121 disposed opposite to each other along a first direction x and a second surface 2122 disposed opposite to each other along a second direction y. The first surface 2121 is connected to the two second surfaces 2122. The second surfaces 2122 are at least partially arc-shaped. The first direction x, the second direction y and the direction of end cap assembly 3 pointing towards electrode body 21 are perpendicular to each other.

[0253] The end cap assembly 3 includes an end cap 31 and an insulating member 32. The end cap 31 closes to the opening 11, and the insulating member 32 is disposed on the side of the end cap 31 facing the electrode body 21. The insulating member 32 includes a main body portion 321 and a plurality of protrusions 322. The main body portion 321 is attached to the end cap 31. The protrusions 322 protrude from the surface of the main body portion 321 away from the end cap 31.

[0254] The insulating film 4 is at least partially located between the electrode body 21 and the housing 1, and at least a portion of the insulating film 4 is fused to the insulating component 32 to form a connection portion 41.

[0255] A heat insulation component 5 is disposed within the housing 1 and is connected to at least one of the electrode body 21 and the insulating component 32. At least a portion of the heat insulation component 5 is located on one side of the connecting portion 41 in the direction from the end cap assembly 3 to the electrode body 21, and protrudes from the electrode body 21 in the direction from the end cap assembly 3. The heat insulation component 5 includes a first heat insulation portion 51 and a second heat insulation portion 52. The first heat insulation portion 51 is located between the outer peripheral surface 212 and the insulating film 4. The second heat insulation portion 52 includes a first sub-portion 521 and a second sub-portion 522. The first sub-portion 521 is connected between the second sub-portion 522 and the first heat insulation portion 51. In the direction from the electrode body 21 to the insulating film 4, a portion of the first sub-portion 521 is located between the protrusion 322 and the insulating film 4. The first sub-portion 521 is provided with a clearance hole 53 for clearance of the connecting portion 41. The second sub-portion 522 is located between the insulating component 32 and the end cap 31. The thickness of the heat insulation component 5 is 0.02 mm to 0.1 mm. In the second direction y, the two opposite ends of the heat insulation component 5 protrude from the connecting part 41. The maximum dimension L1 of the heat insulation component 5 and the dimension L2 of the connecting part 41 satisfy: 4 mm ≤ L1 - L2 ≤ 15 mm. The second direction y is perpendicular to the direction from the end cap assembly 3 to the electrode body 21.

[0256] 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 by, include: The shell has an opening; An electrode assembly, provided with the housing, the electrode assembly including an electrode body and electrode tabs; An end cap assembly includes an end cap and an insulating component, the end cap closing onto the opening, and the insulating component being disposed on the side of the end cap facing the electrode body; An insulating film, at least partially located between the electrode body and the housing, wherein at least a portion of the insulating film is fused to the insulating component to form a connection portion; A heat insulation element is disposed within the housing and is connected to at least one of the electrode body and the insulating component. At least a portion of the heat insulation element is located on one side of the connection portion in the direction of the end cap assembly pointing towards the electrode body, and protrudes from the electrode body in the direction of the electrode body pointing towards the end cap assembly.

2. The battery cell according to claim 1, characterized in that, The electrode body has an end face and an outer peripheral face, the electrode tab extends from the end face, and the outer peripheral face is arranged around the end face and connected to the end face; The heat insulation component includes a first heat insulation portion and a second heat insulation portion. The first heat insulation portion is located between the outer peripheral surface and the insulating film. The second heat insulation portion protrudes from the first heat insulation portion along the direction from the electrode body to the end cap assembly, and at least a portion of the orthographic projection of the second heat insulation portion overlaps with the orthographic projection of the connecting portion.

3. The battery cell according to claim 2, characterized in that, In the direction in which the electrode body points toward the insulating film, a portion of the second heat insulation portion is located between the insulating component and the insulating film.

4. The battery cell according to claim 3, characterized in that, The second heat insulation part is provided with a clearance hole, which is used to avoid the connection part.

5. The battery cell according to claim 3, characterized in that, The second heat insulation part is also disposed between the insulating component and the end cap.

6. The battery cell according to claim 4, characterized in that, The second heat insulation portion includes a first sub-portion and a second sub-portion. The first sub-portion is connected between the second sub-portion and the first heat insulation portion. In the direction from the electrode body to the insulating film, at least a portion of the first sub-portion is located between the insulating component and the insulating film. The first sub-portion is provided with the clearance hole. The second sub-portion is located between the insulating component and the end cap.

7. The battery cell according to claim 6, characterized in that, The clearance hole is also provided in the second sub-part.

8. The battery cell according to claim 2, characterized in that, In the direction of the end cap assembly pointing toward the electrode body, a portion of the second heat insulation portion is located between the insulating component and the electrode body.

9. The battery cell according to claim 2, characterized in that, The outer peripheral surface includes a first surface disposed opposite to each other along a first direction and a second surface disposed opposite to each other along a second direction. The first surface is connected to the two second surfaces. The second surface is at least partially arc-shaped. The first direction, the second direction and the direction of the end cap assembly pointing towards the electrode body are perpendicular to each other. The first heat insulation part is attached to the first surface.

10. The battery cell according to claim 9, characterized in that, The heat insulation component includes two first heat insulation parts and a second heat insulation part, the two first heat insulation parts are arranged opposite to each other along the first direction, and the second heat insulation part is connected between the two first heat insulation parts.

11. The battery cell of claim 1, wherein, The insulating component includes: The main body is fitted to the end cap; A protrusion protrudes from the surface of the main body away from the end cap, and a portion of the heat insulation member is located between the protrusion and the insulating film in the direction from the electrode body to the insulating film.

12. The battery cell according to claim 11, characterized in that, The insulating component includes a plurality of protrusions, the plurality of protrusions including two first protrusions and a second protrusion, the two first protrusions being disposed at opposite ends of the main body, and the second protrusion being located between the two first protrusions; The battery cell includes multiple heat insulation components, including two first heat insulation components and a second heat insulation component. In the direction from the electrode body to the insulating film, a portion of the first heat insulation component is located between the first protrusion and the insulating film, and a portion of the second heat insulation component is located between the second protrusion and the insulating film.

13. The battery cell according to claim 1, characterized in that, The thickness of the insulation element is 0.02 mm to 0.1 mm.

14. The battery cell according to claim 1, characterized in that, In the second direction, the two opposite ends of the heat insulation component protrude from the connecting portion, and the maximum dimension L1 of the heat insulation component and the dimension L2 of the connecting portion satisfy: 4mm≤L1-L2≤15mm. The second direction is perpendicular to the direction of the end cap assembly pointing to the electrode body.

15. A battery device characterized by comprising: It includes multiple battery cells according to any one of claims 1 to 14.

16. An electrical device, comprising: Includes a battery cell according to any one of claims 1 to 14 or a battery device according to claim 15, wherein the battery cell or the battery device is used to store or provide electrical energy.

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