Battery cell, battery device, and electric device

Abstract

The application relates to a battery monomer, a battery device and an electric equipment. The battery monomer comprises a shell, an electrode assembly and an end cover assembly. The end cover assembly comprises an end cover, a first insulating piece and an electrode terminal assembly. The end cover covers an opening. The end cover has a first through hole penetrating in the thickness direction of the end cover. The first insulating piece is arranged on the side of the end cover away from the electrode assembly. The first insulating piece has a second through hole penetrating in the thickness direction of the end cover. The electrode terminal assembly comprises an electrode terminal and a sealing piece. The electrode terminal is electrically connected with the electrode assembly. The electrode terminal is arranged in the first through hole and the second through hole. The sealing piece surrounds the electrode terminal. The sealing piece is arranged between the hole wall of the first through hole and the electrode terminal and between the hole wall of the second through hole and the electrode terminal. The battery monomer provided by the application can form double interface sealing by the sealing piece, improve the sealing capacity of the sealing piece and reduce the risk of sealing failure of the electrode terminal.

Description

Technical Field

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

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

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

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

[0005] In a first aspect, this application proposes a battery cell, which includes a housing, an electrode assembly, and an end cap assembly. The housing has an opening. The electrode assembly is disposed within the housing. The end cap assembly includes an end cap, a first insulating member, and an electrode terminal assembly. The end cap closes to the opening and has a first through-hole extending along the thickness direction of the end cap. The first insulating member is disposed on the side of the end cap opposite to the electrode assembly and has a second through-hole extending along the thickness direction of the end cap. The electrode terminal assembly includes an electrode terminal and a sealing member. The electrode terminal is electrically connected to the electrode assembly and passes through the first and second through-holes. The sealing member surrounds the electrode terminal and is respectively sandwiched between the wall of the first through-hole and the electrode terminal and between the wall of the second through-hole and the electrode terminal.

[0006] The battery cell provided in this application has sealing elements sandwiched between the wall of the first through hole and the electrode terminal, and between the wall of the second through hole and the electrode terminal, to form a seal between the end cap and the electrode terminal, and between the first insulating element and the electrode terminal. This double-interface seal improves the sealing capability of the sealing elements, reduces the risk of electrode terminal seal failure, and improves the reliability of the battery cell. In the event of overcharging or thermal runaway of the battery cell, it also improves the prevention of electrode terminal seal failure and reduces the leakage of hazardous substances.

[0007] According to one embodiment of this application, the electrode terminal includes a post and a rivet. The post is electrically connected to the electrode assembly. The post passes through a first through hole and a second through hole and protrudes from a first insulating member. The rivet is disposed on the side of the first insulating member away from the end cover and is circumferentially disposed on the outer periphery of the portion of the post protruding from the first insulating member. Along the thickness direction of the end cover, the rivet has a groove. The groove is recessed relative to the surface of the rivet facing the seal. A portion of the seal is accommodated in the groove.

[0008] A portion of the seal engages with the groove of the seal, which can provide positioning constraints for the seal and reduce the displacement of the seal due to external forces or environmental changes during operation, thereby giving the seal high sealing performance.

[0009] According to one embodiment of this application, the end cap further includes a second insulating member disposed on the side of the end cap facing the electrode assembly along its thickness direction. The electrode terminal passes through the second insulating member, and a portion of a sealing member is disposed between the second insulating member and the electrode terminal. The partial placement of the sealing member between the second insulating member and the electrode terminal forms a seal between them, further improving the overall sealing effect of the battery cell.

[0010] According to one embodiment of this application, the electrode terminal assembly further includes a heat-resistant layer, at least partially disposed within the housing and located outside the seal. The melting point of the heat-resistant layer is higher than that of the seal. The heat-resistant layer protects the seal, enabling it to withstand the high temperatures during thermal runaway of the battery cell and corrosion from high-temperature substances without failure, reducing physical damage to the seal, thus providing a higher sealing effect and improving the reliability of the battery cell.

[0011] According to one embodiment of this application, a heat-resistant layer is wrapped around the seal. By wrapping the seal with a heat-resistant layer, the heat insulation capability of the seal is improved by physically blocking heat transfer, thereby maintaining its sealing performance and service life.

[0012] According to one embodiment of this application, the seal has a recess that is recessed relative to the surface of the seal; the heat-resistant layer includes a main body and a protrusion, the protrusion protruding from the main body and connected to the surface of the seal, the protrusion being accommodated in the recess. The protrusion and the recess form a fitting structure, which can play a limiting role, preventing the heat-resistant layer from slipping off the seal. Simultaneously, the provision of the protrusion and the recess can increase the connection area between the heat-resistant layer and the seal, increasing the stability of the contact and improving the connection strength.

[0013] According to one embodiment of this application, the heat-resistant layer is configured to be sprayed onto the surface of the seal. The heat-resistant layer can uniformly cover the surface of the seal and also facilitates the simplification of the connection between the heat-resistant layer and the seal with irregular structures.

[0014] According to one embodiment of this application, the thickness of the heat-resistant layer is from 50 μm to 500 μm. A suitable thickness of the heat-resistant layer is beneficial; excessive thickness increases raw material consumption and manufacturing costs, while insufficient thickness leads to inadequate insulation performance and susceptibility to heat damage.

[0015] According to one embodiment of this application, the heat-resistant layer includes a high-temperature resistant material, which is an organosilicone aluminum powder or an organosilicone resin with a melting point greater than or equal to 1000°C.

[0016] According to one embodiment of this application, the heat-resistant layer includes a high-temperature resistant base and an adhesive portion. The high-temperature resistant base is disposed on the side of the adhesive portion opposite to the sealant. The adhesive portion connects the sealant and the high-temperature resistant base. The melting point of the high-temperature resistant base is greater than or equal to 1000°C. The adhesive portion can stably connect the high-temperature resistant base and the sealant, thereby reducing the risk of the heat-resistant layer detaching. Moreover, the use of the adhesive portion can save on the high-temperature resistant base, achieving both heat insulation and cost control.

[0017] According to one embodiment of this application, the seal is a rubber ring. The rubber ring possesses good aging resistance and fatigue resistance, and has low manufacturing cost.

[0018] According to one embodiment of this application, the housing is a steel shell. Steel shells tend to accumulate heat, leading to higher temperatures near the end cap and making the seal prone to heat-induced failure. Therefore, by forming a seal between the end cap and the electrode terminal, and between the first insulating member and the electrode terminal, a double-interface seal is achieved. This also increases the thickness dimension of the seal, improving its sealing capability.

[0019] Secondly, this application provides a battery device including the aforementioned battery cell.

[0020] 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.

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

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

[0023] Figure 1 This is a schematic diagram of the structure of a vehicle provided in one embodiment of this application; Figure 2This is an exploded view of a battery device provided in an embodiment of this application; Figure 3 This is an exploded view of a single battery cell provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the end cap assembly of a battery cell provided in an embodiment of this application; Figure 5 This is an exploded view of the end cap assembly of a battery cell provided in an embodiment of this application; Figure 6 A top view of the end cap assembly of a battery cell provided in one embodiment of this application; Figure 7 yes Figure 6 Cross-sectional view at point AA; Figure 8 yes Figure 7 This is a magnified view of a specific area; Figure 9 This is a partial structural schematic diagram of the end cap assembly of a battery cell provided in an embodiment of this application; Figure 10 This is a partial structural schematic diagram of the end cap assembly of a battery cell provided in another embodiment of this application; Figure 11 This is a partial structural schematic diagram of the end cap assembly of a battery cell provided in another embodiment of this application; Figure 12 This is a schematic diagram of the structure of the sealing element of a battery cell provided in one embodiment of this application.

[0024] The accompanying drawings may not be drawn to scale.

[0025] Explanation of reference numerals in the attached figures: 1000, Vehicle; 100, Battery unit; 200, Controller; 300, Motor; 1a. Battery module; 1b. First housing; 1c. Second housing; 1. Housing; 11. Opening; 2. Electrode assembly; 3. End cap assembly; 31. End cap; 311. First through hole; 32. First insulating component; 321. Second through hole; 33. Electrode terminal assembly; 331. Electrode terminal; 3311. Electrode post; 3312. Riveting component; 33121. Groove; 332. Sealing component; 3321. Recess; 333. Heat-resistant layer; 3331. Main body; 3332. Protrusion; 3333. High-temperature resistant base; 3334. Adhesive part; 34. Second insulating component; z. Thickness direction. Detailed Implementation

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] In this application, "multiple" means two or more (including two).

[0033] 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.

[0034] 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.

[0035] When the opening and pressure relief valve of a battery cell is delayed or the opening process is not smooth, internal heat cannot be dissipated in time, leading to heat accumulation. With continued heat accumulation, the temperature in the end cap area rises abnormally. High temperatures can easily cause deformation or even melting of the seals, resulting in failure of the electrode terminal sealing structure and reducing the reliability of the battery cell. The above statements are for providing background information related to this application only and do not necessarily constitute prior art.

[0036] The battery cell provided in this application has sealing elements sandwiched between the wall of the first through hole and the electrode terminal, and between the wall of the second through hole and the electrode terminal, to form a seal between the end cap and the electrode terminal, and between the first insulating element and the electrode terminal. This double-interface seal improves the sealing capability of the sealing elements, reduces the risk of electrode terminal seal failure, and improves the reliability of the battery cell. In the event of overcharging or thermal runaway of the battery cell, it also improves the prevention of electrode terminal seal failure and reduces the leakage of hazardous substances.

[0037] The battery cell described in this application is applicable to batteries and electrical devices that use batteries. This battery cell can be used, but is not limited to, batteries, and can also be used in products such as vehicles, aircraft, ships, electronic devices, and power tools, thereby improving the reliability of these products.

[0038] Electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.

[0039] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device according to an embodiment of this application.

[0040] 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.

[0041] Please refer to Figure 2 , Figure 2 An exploded view of a battery device 100 provided in some embodiments of this application.

[0042] In some embodiments, the battery device 100 may include one or more battery cell assemblies for providing voltage and capacity.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] In some embodiments, the housing is used to house individual battery cells, and the housing can have various structures.

[0050] 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 cylindrical electrode, a cuboid, etc.

[0051] 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.

[0052] 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.

[0053] In some embodiments, the battery device 100 may be an energy storage device.

[0054] 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.

[0055] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0056] 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.

[0057] 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.

[0058] This application provides a battery cell that includes a housing and an electrode assembly housed within the housing.

[0059] 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).

[0060] The outer shell can be a hollow structure, with an internal cavity for accommodating the electrode assembly and electrolyte.

[0061] 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.

[0062] In some embodiments, the housing includes a housing and an end cap, the housing having an opening and the end cap being attached to the housing and covering the opening.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] The end caps are attached to the housing by welding, bonding, snap-fitting, or other means.

[0068] 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.

[0069] Electrode assemblies are the components within a single battery cell where electrochemical reactions occur. The casing may contain one or more electrode assemblies.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.).

[0075] As an example, the positive electrode film layer includes a positive electrode active material, which may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0076] In some embodiments, the negative electrode may include a negative current collector.

[0077] 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.).

[0078] 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.

[0079] 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.

[0080] 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.

[0081] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0082] 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.

[0083] 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.

[0084] Inorganic particle coating, organic particle coating, or organic / inorganic composite coating can also be applied to the surface of the separator.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0094] 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.

[0095] 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.

[0096] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0097] In some embodiments, the electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0098] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0099] In some implementations, the electrode assembly is a stacked structure.

[0100] 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.

[0101] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0102] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0103] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0104] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0105] 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.

[0106] In some embodiments, the electrode assembly is a wound structure. The positive electrode tab is wound multiple turns along the winding direction. Optionally, the end of the positive electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked in the axial direction of the electrode assembly. Optionally, the positive electrode tab is annular.

[0107] In some embodiments, the negative electrode tab is wound multiple turns along the winding direction. Optionally, the end of the negative electrode tab is bent by a flattening or smoothing process to form a multi-layered structure stacked in the axial direction of the electrode assembly. The negative electrode tab is annular.

[0108] In some embodiments, the electrode assembly includes an electrode body. As an example, the electrode body includes a positive electrode film, a portion of the positive electrode current collector covered by the positive electrode film, a negative electrode film, a portion of the negative electrode current collector covered by the negative electrode film, and a separator.

[0109] The positive and negative tabs can be led out from the same end of the electrode body, or they can be led out from opposite ends of the electrode body. At least a portion of the positive tab protrudes to the outside of the insulating member, and at least a portion of the negative tab protrudes to the outside of the insulating member.

[0110] See Figures 3 to 8 , Figure 3 This is an exploded view of a single battery cell provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the end cap assembly of a battery cell provided in an embodiment of this application; Figure 5 This is an exploded view of the end cap assembly of a battery cell provided in an embodiment of this application; Figure 6 A top view of the end cap assembly of a battery cell provided in one embodiment of this application; Figure 7 yes Figure 6 Cross-sectional view at point AA; Figure 8 yes Figure 7 This is a magnified view of a portion of the image.

[0111] like Figures 3 to 8As shown, this application proposes a battery cell, which includes a housing 1, an electrode assembly 2, and an end cap assembly 3. The housing 1 has an opening 11. The electrode assembly 2 is disposed within the housing 1. The end cap assembly 3 includes an end cap 31, a first insulating member 32, and an electrode terminal assembly 33. The end cap 31 covers the opening 11 and has a first through hole 311 extending through the thickness direction z of the end cap 31. The first insulating member 32 is disposed on the side of the end cap 31 away from the electrode assembly 2 and has a second through hole 321 extending through the thickness direction z of the end cap 31. The electrode terminal assembly 33 includes an electrode terminal 331 and a sealing member 332. The electrode terminal 331 is electrically connected to the electrode assembly 2 and passes through the first through hole 311 and the second through hole 321. The sealing member 332 surrounds the electrode terminal 331 and is respectively sandwiched between the hole wall of the first through hole 311 and the electrode terminal 331 and the hole wall of the second through hole 321 and the electrode terminal 331.

[0112] Electrode assembly 2 is the component in the battery cell where electrochemical reactions occur.

[0113] In some examples, the housing 1 may contain one or more electrode assemblies 2.

[0114] In some examples, electrode assembly 2 includes an electrode body and a tab extending from one end of the electrode body. The tab is electrically connected to electrode terminal 331.

[0115] In some examples, the tabs can be directly connected to the electrode terminals 331; in other examples, the tabs can be connected to the electrode terminals 331 via conductive elements, such as current collectors. During the charging and discharging process of the battery, the positive and negative active materials of the electrode body react with the electrolyte, and the tabs are connected to the electrode terminals 331 via current collectors to form a current loop.

[0116] The end cap assembly 3 is a component used to cooperate with the housing 1 to form the internal cavity of the battery cell. The formed internal cavity can be used to accommodate the electrode assembly 2 and other components.

[0117] The end cap assembly 3 includes an end cap 31, which covers the opening 11 of the housing 1, and the end cap 31 and the housing 1 together form an internal cavity.

[0118] In some embodiments, the end cap 31 may be a generally plate-like structure, such as a circular plate-like structure, a rectangular plate-like structure, or a plate-like structure of other shapes.

[0119] In some embodiments, the end cap 31 may be made of an insulating material (e.g., plastic) or a conductive material (e.g., metal).

[0120] As an example, the end cap 31 has a first surface and a second surface opposite to each other along the thickness direction z. The first surface faces the electrode assembly 2, and the second surface faces away from the electrode assembly 2. The end cap 31 is provided with a first through hole 311, which connects the first surface and the second surface.

[0121] The end cap assembly 3 includes a first insulating member 32, which is located on the side of the end cap 31 away from the electrode assembly 2, so as to insulate the end cap 31 and the electrode terminal 331 to improve the safety performance of the battery cell.

[0122] The first insulating element 32 is provided with a second through hole 321, which is connected to the first through hole 311.

[0123] For example, the first insulating element 32 is made of an insulating material, such as plastic, rubber, etc.

[0124] As an example, the first insulating member 32 has a third surface and a fourth surface opposite to each other along the thickness direction z, the third surface facing the end cap 31 and the fourth surface facing away from the end cap 31, and the first insulating member 32 is provided with a second through hole 321, which connects the third surface and the fourth surface.

[0125] As an example, the end cap 31 has a limiting portion that is recessed relative to the surface of the end cap 31 facing the first insulating member 32, and at least a portion of the first insulating member 32 is embedded in the limiting portion. The connection between the first insulating member 32 and the end cap 31 is stable.

[0126] Optionally, the structure of the first insulating element 32 is generally rectangular or rectangular.

[0127] Electrode terminals 331 are disposed on end cap 31. A portion of electrode terminals 331 is disposed on the side of end cap 31 facing electrode assembly 2 along the thickness direction z, and a portion of electrode terminals 331 is disposed on the side of end cap 31 away from electrode assembly 2 along the thickness direction z.

[0128] The seal 332 is arranged circumferentially around the electrode terminal 331, and the seal 332 is annular.

[0129] As an example, a portion of the seal 332 is clamped between the electrode terminal 331 and the wall of the first through hole 311 to seal the end cap 31 and the electrode terminal 331, and a portion of the seal 332 is clamped between the electrode terminal 331 and the wall of the second through hole 321 to seal the first insulator 32 and the electrode terminal 331.

[0130] The battery cell provided in this application has a sealing element 332 sandwiched between the wall of the first through hole 311 and the electrode terminal 331, and between the wall of the second through hole 321 and the electrode terminal 331, to form a seal between the end cap 31 and the electrode terminal 331, and between the first insulating element 32 and the electrode terminal 331. This dual-interface seal improves the sealing capability of the sealing element 332, reduces the risk of electrode terminal 331 seal failure, and improves the reliability of the battery cell. In the event of battery cell overcharging or thermal runaway, it improves the sealing failure of electrode terminal 331 and reduces the leakage of hazardous substances.

[0131] According to one embodiment of this application, such as Figure 5 and Figure 8 As shown, the electrode terminal 331 includes a pole post 3311 and a riveting member 3312. The pole post 3311 is electrically connected to the electrode assembly 2. The pole post 3311 passes through the first through hole 311 and the second through hole 321 and protrudes from the first insulating member 32. The riveting member 3312 is disposed on the side of the first insulating member 32 away from the end cover 31, and the riveting member 3312 is circumferentially disposed around the outer periphery of the portion of the pole post 3311 protruding from the first insulating member 32. Along the thickness direction z of the end cover 31, the riveting member 3312 has a groove 33121. The groove 33121 is recessed relative to the surface of the riveting member 3312 facing the sealing member 332, and a portion of the sealing member 332 is accommodated within the groove 33121.

[0132] As an example, the riveting component 3312 has a disc-shaped structure with a rivet hole (not shown in the figure) in the center that mates with the pole post 3311. The riveting component 3312 and the pole post 3311 are riveted together to form a whole.

[0133] The pole post 3311 is a structure that extends along the thickness direction z of the end cap 31.

[0134] As an example, the pole post 3311 includes a post body and a limiting part. The post body passes through a first through hole 311 and a second through hole 321, and the part of the post body protruding from the first insulating member 32 is riveted to the riveting member 3312. The diameter of the limiting part is larger than the diameter of the post body.

[0135] Both the rivet 3312 and the pole post 3311 can be made of a conductive metal material with a certain hardness and strength, such as one or more of copper, iron, aluminum, stainless steel, and aluminum alloy.

[0136] In some examples, the rivet 3312 and the pole post 3311 are made of the same material; in other examples, the rivet 3312 and the pole post 3311 are made of different materials.

[0137] In some examples, the first insulating element 32 covers the bottom surface of the riveting element 3312 and at least part of its outer peripheral surface. This effectively increases the creepage distance from the riveting element 3312 or the electrode terminal 331 to the end cap 31, reducing the risk of leakage and short circuit and improving the reliability of the battery cell.

[0138] As an example, the rivet 3312 has a groove 33121 that is recessed inward relative to the bottom surface of the seal 332 along the thickness direction z of the rivet 3312, and the groove 33121 is engaged with the portion of the seal 332 that protrudes from the first insulating member 32.

[0139] A portion of the seal 332 engages with the groove 33121 of the seal 332, which can form a positioning constraint on the seal 332, reduce the displacement of the seal 332 due to external forces or environmental changes during operation, and thus enable the seal 332 to have high sealing performance.

[0140] According to one embodiment of this application, such as Figure 8 As shown, the end cap 31 also includes a second insulating member 34. The second insulating member 34 is disposed on the side of the end cap 31 facing the electrode assembly 2 along the thickness direction z. The electrode terminal 331 passes through the second insulating member 34. A portion of the sealing member 332 is disposed between the second insulating member 34 and the electrode terminal 331.

[0141] The second insulating element 34 serves to insulate between the end cap 31 and the electrode assembly 2, thereby improving the reliability of the battery cell.

[0142] The second insulating member 34 can be a thin plate structure, and its shape and area are roughly the same as those of the end cap 31. The second insulating member 34 is attached to the side of the end cap 31 facing the electrode assembly 2 along its thickness direction z.

[0143] As an example, the end cap 31 is rectangular, and the second insulating element 34 is generally rectangular in structure.

[0144] As an example, the end cap 31 is in the shape of a disk, and the second insulating element 34 is generally circular in structure.

[0145] The second insulating element 34 is made of insulating material, such as plastic or PVC.

[0146] In some examples, the second insulating member 34 is provided with a third through hole along the thickness direction z, and the electrode terminal 331 is sequentially provided with the third through hole, the first through hole 311 and the second through hole 321.

[0147] As an example, the pole post 3311 includes a post body and a limiting portion. The post body has a third through hole, a first through hole 311, and a second through hole 321. The portion of the post body protruding from the first insulating member 32 is riveted to the riveting member 3312. The diameter of the limiting portion is larger than the diameter of the post body. The sealing member 332 is fitted onto the post body, and a portion of the sealing member 332 abuts against the end cap 31 and the limiting portion. This arrangement effectively suppresses the risk of the sealing member 332 falling off.

[0148] Optionally, the seal 332 includes a first step portion and a second step portion. The radial dimension of the first step portion is greater than that of the second step portion. Along the thickness direction z, the second step portion protrudes from the first step portion. The first step portion abuts against the end cap 31 and the limiting portion. The second step portion passes through the hole wall of the first through hole 311 and the electrode terminal 331 and the hole wall of the second through hole 321 and the electrode terminal 331.

[0149] A portion of the seal 332 is disposed between the second insulator 34 and the electrode terminal 331, forming a seal between the second insulator 34 and the electrode terminal 331, thereby further improving the overall sealing effect of the battery cell.

[0150] See also Figure 9 , Figure 9 This is a partial structural schematic diagram of the end cap assembly of a battery cell provided in one embodiment of this application.

[0151] According to one embodiment of this application, such as Figure 9 As shown, the electrode terminal assembly 33 also includes a heat-resistant layer 333, at least a portion of which is disposed within the housing 1 and located outside the seal 332. The melting point of the heat-resistant layer 333 is greater than that of the seal 332.

[0152] In some examples, the surface of the seal 332 is provided with a heat-resistant layer 333; alternatively, a portion of the surface of the seal 332 is provided with a heat-resistant layer 333.

[0153] As an example, the seal 332 includes a first part and a second part, the first part being connected to the second part, the first part being disposed on the side facing the electrode assembly 2 along the thickness direction z, the second part being disposed on the side of the first part away from the electrode assembly 2 along the thickness direction z, and the heat-resistant layer 333 being disposed on the first part.

[0154] In some examples, the heat-resistant layer 333 is configured to be coated on the surface of the seal 332.

[0155] In other examples, the heat-resistant layer 333 is connected to the seal 332 via a connector.

[0156] When a battery cell experiences thermal runaway, it continuously releases high-temperature substances from inside the cell, causing the cell's casing 1 to reach a high temperature. This can lead to the first insulating component 32 and the sealing component 332 being melted by the high temperature, affecting the sealing effect.

[0157] Optionally, the melting point of the heat-resistant layer 333 is greater than or equal to 500°C.

[0158] The heat-resistant layer 333 protects the seal 332, and can withstand the high temperature during thermal runaway of the battery cell and the corrosion of high-temperature substances without failure. It reduces physical damage to the seal 332, so that the seal 332 has a high sealing effect, thereby improving the reliability of the battery cell.

[0159] According to one embodiment of this application, a heat-resistant layer 333 covers the seal 332. By covering the seal 332 with a heat-resistant layer 333, the heat insulation capability of the seal 332 is improved by physically blocking heat transfer, thereby maintaining its sealing performance and service life.

[0160] See also Figure 10 , Figure 10 This is a partial structural schematic diagram of the end cap assembly of a battery cell provided in another embodiment of this application.

[0161] According to one embodiment of this application, such as Figure 10 As shown, the seal 332 has a recess 3321, which is recessed relative to the surface of the seal 332. The heat-resistant layer 333 includes a main body 3331 and a protrusion 3332, the protrusion 3332 protruding from the main body 3331, the main body 3331 being connected to the surface of the seal 332, and the protrusion 3332 being received in the recess 3321.

[0162] In some examples, the recess 3321 is provided around the circumference of the seal 332, and the protrusion 3332 is provided around the circumference of the main body 3331, with the protrusion 3332 fitting into the recess 3321. This results in a larger connection surface between the heat-resistant layer 333 and the seal 332, improving the stability of their connection.

[0163] In other examples, the seal 332 has a plurality of recesses 3321 spaced apart. The plurality of recesses 3321 are arranged circumferentially along the seal 332; alternatively, the plurality of recesses 3321 are arranged along the thickness direction z of the seal 332.

[0164] The protrusion 3332 and the recess 3321 form an interlocking structure, which serves as a limiting mechanism to prevent the heat-resistant layer 333 from slipping off the seal 332. Simultaneously, the protrusion 3332 and the recess 3321 increase the connection area between the heat-resistant layer 333 and the seal 332, thereby increasing contact stability and improving connection strength.

[0165] According to one embodiment of this application, the heat-resistant layer 333 is configured to be sprayed onto the surface of the seal 332. The heat-resistant layer 333 can uniformly cover the surface of the seal 332, and also facilitates the simplification of the connection between the heat-resistant layer 333 and the irregularly shaped seal 332.

[0166] Prepare a heat-resistant slurry, spray the heat-resistant slurry onto the surface of the seal 332, and cure it to form a heat-resistant layer 333.

[0167] According to one embodiment of this application, the thickness of the heat-resistant layer 333 is 50 μm to 500 μm.

[0168] In some examples, the thickness of the heat-resistant layer 333 is 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm or other ranges consisting of any two of the above endpoints.

[0169] Optionally, the thickness of the heat-resistant layer 333 is from 80 μm to 280 μm.

[0170] The heat-resistant layer 333 has an appropriate thickness. If the thickness of the heat-resistant layer 333 is too large, it will increase the consumption of raw materials and increase the manufacturing cost. If the thickness of the heat-resistant layer 333 is too small, it will cause defects such as insufficient heat insulation performance and easy damage to the heat-resistant layer 333.

[0171] According to one embodiment of this application, the heat-resistant layer 333 comprises a high-temperature resistant material, such as organosilicone aluminum powder or organosilicone resin with a melting point greater than or equal to 1000°C. The heat-resistant layer 333 has a high melting point, which reduces the risk of deformation or melting of the seal 332 in the event of thermal runaway in a single battery cell.

[0172] In some examples, the heat-resistant layer 333 consists only of high-temperature resistant materials, and the melting point of the heat-resistant layer 333 is greater than or equal to 1000°C.

[0173] In other examples, the heat-resistant layer 333 may also include other materials, which may be combined with the high-temperature resistant material, or the high-temperature resistant material may form a high-temperature resistant layer, other materials may form a film layer, and the high-temperature resistant layer and the film layer may be combined to form a composite layer.

[0174] As an example, the heat-resistant layer 333 also includes at least one of a heat dissipation material, a flexible material, and an insulating material. The heat dissipation material includes a graphene-based composite material, the flexible material includes phenyl silicone rubber or poly(m-phenylene isophthalamide) fiber, and the insulating material includes polytetrafluoroethylene or polyvinylidene fluoride.

[0175] Optionally, the heat-resistant layer 333 includes a high-temperature resistant material, a heat-dissipating material, a flexible material, and an insulating material. The flexible material gives the coating a certain degree of flexibility, allowing the heat-resistant layer 333 to adhere well to the seal 332, and to have a high degree of consistency with the deformation of the seal 332 when it deforms, reducing the risk of detachment.

[0176] See also Figure 11 , Figure 11 This is a partial structural schematic diagram of the end cap assembly of a battery cell provided in another embodiment of this application.

[0177] According to one embodiment of this application, such as Figure 11 As shown, the heat-resistant layer 333 includes a high-temperature resistant base 3333 and an adhesive portion 3334. The high-temperature resistant base 3333 is disposed on the side of the adhesive portion 3334 away from the seal 332. The adhesive portion 3334 is connected to the seal 332 and the high-temperature resistant base 3333. The melting point of the high-temperature resistant base 3333 is greater than or equal to 1000℃.

[0178] In some examples, the material of the high-temperature resistant base 3333 includes organosilicone aluminum powder or organosilicone resin with a melting point greater than or equal to 1000°C.

[0179] In some examples, the material of the adhesive portion 3334 includes polytetrafluoroethylene or polyvinylidene fluoride. The adhesive portion 3334 has both adhesive properties and a certain degree of insulation.

[0180] The adhesive portion 3334 can stably connect the high-temperature resistant base 3333 and the seal 332, thereby reducing the risk of the heat-resistant layer 333 falling off. Moreover, the use of the adhesive portion 3334 can save the high-temperature resistant base 3333, which not only has a heat insulation effect but also controls costs.

[0181] According to one embodiment of this application, the sealing element 332 is a rubber ring. The rubber ring has good aging resistance and fatigue resistance, and has low manufacturing cost. When the rubber ring is combined with the heat-resistant layer 333, the heat-resistant layer 333 achieves a reliable heat protection effect, meeting the sealing protection requirements of the battery cell in a high-temperature environment. Moreover, the low cost of the rubber ring effectively reduces the overall manufacturing cost of the battery cell.

[0182] According to one embodiment of this application, the housing 1 is a steel housing.

[0183] The steel casing easily accumulates heat, leading to high temperatures near the end cap 31 and making the seal 332 prone to heat-induced failure. Therefore, the seal 332 forms a double-interface seal between the end cap 31 and the electrode terminal 331, and also between the first insulating member 32 and the electrode terminal 331. This double-interface seal also increases the thickness (z) dimension of the seal 332, improving its sealing capability. Furthermore, by providing a heat-resistant layer 333 to the seal 332, heat transfer to the seal 332 is blocked, thus protecting the seal 332 and further reducing the risk of high temperatures during battery cell thermal runaway and corrosion of the seal 332 by high-temperature substances.

[0184] According to one embodiment of this application, such as Figure 5 As shown, the seal 332 includes a flange portion and a connecting portion, with the flange portion disposed at one end of the connecting portion facing the electrode assembly along the thickness direction.

[0185] See Figure 12 , Figure 12 This is a schematic diagram of the structure of the sealing element of a battery cell provided in one embodiment of this application.

[0186] According to one embodiment of this application, such as Figure 12 As shown, the seal 332 includes two flange portions and a connecting portion, with the two flange portions respectively disposed at both ends of the connecting portion along the thickness direction. In a second aspect, this application provides a battery device including the aforementioned battery cell.

[0187] 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.

[0188] According to some embodiments of this application, such as Figures 3 to 7 , Figure 10 As shown, this application provides a battery cell, which includes a housing 1, an electrode assembly 2, and an end cap assembly 3. The housing 1 has an opening 11. The housing 1 is a steel shell. The electrode assembly 2 is disposed inside the housing 1. The end cap assembly 3 includes an end cap 31, a first insulating member 32, an electrode terminal assembly 33, and a second insulating member 34.

[0189] End cap 31 covers opening 11, and end cap 31 has a first through hole 311 extending along the thickness direction z of end cap 31.

[0190] The first insulating member 32 is disposed on the side of the end cap 31 away from the electrode assembly 2, and the first insulating member 32 has a second through hole 321 extending along the thickness direction z of the end cap 31.

[0191] The electrode terminal assembly 33 includes an electrode terminal 331, a sealing element 332, and a heat-resistant layer 333. The electrode terminal 331 is electrically connected to the electrode assembly 2. The electrode terminal 331 includes a pole post 3311 and a riveting element 3312. The pole post 3311 passes through a first through hole 311 and a second through hole 321. The sealing element 332 surrounds the pole post 3311 and is respectively sandwiched between the wall of the first through hole 311 and the pole post 3311 and the wall of the second through hole 321 and the pole post 3311. The pole post 3311 protrudes from the first insulating element 32. A riveting member 3312 is disposed on the side of the first insulating member 32 opposite to the end cap 31, and the riveting member 3312 is circumferentially disposed on the outer periphery of the portion of the pole post 3311 protruding from the first insulating member 32; along the thickness direction z of the end cap 31, the riveting member 3312 has a groove 33121, the groove 33121 being recessed relative to the surface of the riveting member 3312 facing the sealing member 332, and a portion of the sealing member 332 being accommodated within the groove 33121. A heat-resistant layer 333 covers the sealing member 332, and the melting point of the heat-resistant layer 333 is greater than the melting point of the sealing member 332. The heat-resistant layer 333 is configured to be sprayed onto the surface of the sealing member 332. The sealing member 332 has a recess 3321, the recess 3321 being recessed relative to the surface of the sealing member 332. The heat-resistant layer 333 includes a main body 3331 and a protrusion 3332. The protrusion 3332 protrudes from the main body 3331, and the main body 3331 is connected to the surface of the seal 332. The protrusion 3332 is accommodated in the recess 3321. The thickness of the heat-resistant layer 333 is 50 μm to 500 μm. The heat-resistant layer 333 includes a high-temperature resistant material, such as aluminum silicate powder or silicone resin with a melting point greater than or equal to 1000℃. The seal 332 is a rubber ring.

[0192] The second insulating member 34 is disposed on the side of the end cap 31 facing the electrode assembly 2 along the thickness direction z. The electrode terminal 331 passes through the second insulating member 34, and a portion of the sealing member 332 is disposed between the second insulating member 34 and the electrode terminal 331.

[0193] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The shell has an opening; Electrode assembly, disposed within the housing; An end cap assembly includes an end cap, a first insulating member, and an electrode terminal assembly. The end cap covers the opening and has a first through-hole extending along the thickness direction of the end cap. The first insulating member is disposed on the side of the end cap opposite to the electrode assembly and has a second through-hole extending along the thickness direction of the end cap. The electrode terminal assembly includes an electrode terminal and a sealing member. The electrode terminal is electrically connected to the electrode assembly and passes through the first through-hole and the second through-hole. The sealing member surrounds the electrode terminal and is respectively sandwiched between the wall of the first through-hole and the electrode terminal and between the wall of the second through-hole and the electrode terminal.

2. The battery cell according to claim 1, characterized in that, The electrode terminal includes a pole and a rivet. The pole is electrically connected to the electrode assembly. The pole passes through the first through hole and the second through hole and protrudes from the first insulating member. The rivet is disposed on the side of the first insulating member away from the end cap and is circumferentially disposed on the outer periphery of the portion of the pole protruding from the first insulating member. The rivet has a groove along the thickness direction of the end cap, the groove being recessed relative to the surface of the rivet facing the seal, and a portion of the seal is accommodated within the groove.

3. The battery cell according to claim 1, characterized in that, The end cap further includes a second insulating member disposed on the side of the end cap facing the electrode assembly along the thickness direction. The electrode terminal passes through the second insulating member, and a portion of the sealing member is disposed between the second insulating member and the electrode terminal.

4. The battery cell according to claim 1, characterized in that, The electrode terminal assembly further includes a heat-resistant layer, at least partially disposed within the housing and located outside the seal, wherein the melting point of the heat-resistant layer is greater than that of the seal.

5. The battery cell according to claim 4, characterized in that, The heat-resistant layer covers the seal.

6. The battery cell according to claim 4, characterized in that, The seal has a recess that is recessed relative to the surface of the seal. The heat-resistant layer includes a main body and a protrusion. The protrusion protrudes from the main body, the main body is connected to the surface of the seal, and the protrusion is accommodated in the recess.

7. The battery cell according to claim 4, characterized in that, The heat-resistant layer is configured to be sprayed onto the surface of the seal.

8. The battery cell according to claim 4, characterized in that, The thickness of the heat-resistant layer is 50 μm to 500 μm.

9. The battery cell according to claim 4, characterized in that, The heat-resistant layer includes a high-temperature resistant material, which is an organosilicone aluminum powder or organosilicone resin with a melting point greater than or equal to 1000℃.

10. The battery cell according to claim 4, characterized in that, The heat-resistant layer includes a high-temperature resistant base and an adhesive portion. The high-temperature resistant base is disposed on the side of the adhesive portion away from the sealant. The adhesive portion is connected to the sealant and the high-temperature resistant base. The melting point of the high-temperature resistant base is greater than or equal to 1000°C.

11. The battery cell according to claim 1, characterized in that, The sealing element is a rubber ring; and / or, The shell is made of steel.

12. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1 to 11.

13. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1 to 11 or a battery device according to claim 12, wherein the battery cell or the battery device is used to store or provide electrical energy.

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