Battery cell, battery device and electric apparatus

Abstract

Provided in the embodiments of the present application are a battery cell, a battery device and an electric apparatus. The battery cell comprises: a casing, the casing comprising a casing body having a metal layer, and a cover plate, the casing body being of a hollow structure having a first opening, the cover plate covering the first opening, and the casing body being connected to the cover plate; and an electrode assembly, the electrode assembly being accommodated in the hollow structure. The casing further comprises reinforcing structures, wherein the reinforcing structures and the casing body and / or the cover plate are stacked and connected, and the tensile strength of the reinforcing structures is greater than or equal to the tensile strength of the casing body and the cover plate. The battery cell, the battery device and the electric apparatus provided in the embodiments of the present application can improve the strength of the casing of the battery cell and improve the safety performance of the battery device.

Description

A battery cell, a battery device, and an electrical appliance. Technical Field

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

[0002] For electric vehicles and large-scale energy storage systems, the energy density of battery devices is a key performance indicator. With the pursuit of higher energy densities, the design and manufacture of battery devices face a series of challenges, one of which is safety.

[0003] Aluminum casings are widely used as the outer shell material for battery cells due to their lightweight, good thermal conductivity, and ease of processing. However, under abusive conditions, such as overcharging or mechanical impact, violent chemical reactions may occur inside the battery cell, leading to the generation of large amounts of heat and gas. This causes a rapid increase in internal pressure, placing a significant pressure load on the aluminum casing. In extreme cases, this pressure may exceed the aluminum casing's tolerance limit, causing it to rupture and preventing directional pressure relief. Therefore, enhancing the strength of the battery cell casing has become a pressing issue.

[0004] Summary of the Invention

[0005] This application provides a battery cell, a battery device, and an electrical appliance, which can enhance the strength of the battery cell's casing and improve the safety performance of the battery device.

[0006] In a first aspect, a battery cell is provided, comprising a housing, the housing including a shell having a metal layer and a cover plate, the shell being a hollow structure having a first opening, the cover plate covering the first opening, and the shell being connected to the cover plate; an electrode assembly housed in the hollow structure; wherein the housing further includes a reinforcing structure, the reinforcing structure being laminated and connected to the shell and / or the cover plate, and the tensile strength of the reinforcing structure being greater than or equal to the tensile strength of the shell and the cover plate.

[0007] This application embodiment enhances the tensile strength of the casing by reinforcing the surface of the metal layer of the housing and / or the metal layer of the cover plate, thereby increasing the casing's resistance to deformation and improving its stability. By strengthening the casing of the battery cell, the internal electrochemical system of the battery can be protected, preventing leakage of active materials and significantly improving the safety performance of the battery device. Furthermore, the reinforced casing can reduce damage to the battery caused by mechanical shock or vibration during transportation and use, extending the battery's lifespan and improving its reliability and durability.

[0008] In some embodiments, the reinforcing structure is disposed on the side of the cover plate or the housing away from the electrode assembly.

[0009] The embodiments of this application reduce the space occupied inside the battery cell by reinforcing the structure located on the outside of the casing or cover, and are also easier to process and implement.

[0010] In some embodiments, a weld is formed at the connection between the housing and the cover plate, and the reinforcing structure is a structure that continuously covers the weld.

[0011] This application embodiment, by setting the reinforcing structure to be a continuous, integrated structure covering the weld seam, can enhance the strength of the weld seam area of ​​the outer shell and reduce the possibility of cracking of the outer shell in the weld seam area.

[0012] In some embodiments, the reinforcement structure covers the entire weld seam.

[0013] In some embodiments, the reinforcing structure has a second opening, the reinforcing structure includes a first wall and at least one second wall opposite to the second opening, the first wall and the second wall enclosing a receiving cavity, the first wall being stacked with a cover plate, the second wall being stacked with a housing, and the weld being accommodated in the receiving cavity.

[0014] This application embodiment, by setting the reinforcing structure to be a continuous, integrated structure covering the weld seam, can enhance the strength of the weld seam area of ​​the outer shell and reduce the possibility of cracking of the outer shell in the weld seam area.

[0015] In some embodiments, the cover plate is provided with electrode terminals and / or a pressure relief mechanism, and the first wall is provided with a through hole, which is disposed opposite to the electrode terminals or pressure relief mechanism disposed on the cover plate.

[0016] In some embodiments, the reinforcing structure includes a first part and a second part, the first part and the second part being respectively fitted onto the outer shell, the first part and the second part being connected to form a receiving cavity, and the weld being accommodated in the receiving cavity.

[0017] This application embodiment, by setting a reinforcing structure that continuously covers the weld seam, can enhance the strength of the weld seam area of ​​the outer shell, reduce the possibility of cracking of the outer shell in the weld seam area, and the reinforcing structure is divided into two parts, which is easier to process and completely covers the shell and cover plate, further enhancing the strength of the outer shell.

[0018] In some embodiments, the side of the first or second portion facing the cover plate is provided with a through hole, which is disposed opposite to the electrode terminal or pressure relief mechanism disposed on the cover plate.

[0019] In some embodiments, both the first part and the second part include a top wall and a side wall, the top walls of the first part and the second part are disposed opposite to each other, the side walls of the first part and the second part are connected, and the top wall of the first part or the second part is stacked with a cover plate.

[0020] The embodiments of this application, by completely offsetting the gap at the connection between the first and second parts of the reinforced structure from the weld, can further enhance the strength of the weld area of ​​the outer shell and reduce the possibility of cracking of the outer shell in the weld area.

[0021] In some embodiments, the reinforcing structure is made of carbon fiber resin composite material.

[0022] In some embodiments, the thickness of the reinforcing structure ranges from [0.1 mm to 0.5 mm].

[0023] In some embodiments, the range of the first threshold is [200MPa, 2500MPa].

[0024] By setting the thickness range and tensile strength of the reinforcing structure, the embodiments of this application can ensure that the reinforcing structure meets sufficient strength performance while minimizing the occupation of the internal space of the battery device, thereby optimizing the energy density of the battery device.

[0025] In some embodiments, the housing further includes a heat insulation layer, which is laminated with the reinforcing structure, the cover plate, or the housing, and the heat insulation layer is located on the side of the reinforcing structure facing the electrode assembly.

[0026] The embodiments of this application, by setting a heat insulation layer and its position, can effectively improve the high temperature resistance of the outer shell and enhance the overall strength of the outer shell.

[0027] In some embodiments, the thermal insulation layer is located between the reinforcing structure and the outer shell.

[0028] The embodiments of this application reduce the space occupied inside the battery cell by setting the heat insulation layer and the reinforcing structure to be located on the outside of the shell or cover plate, and are also easier to process and implement.

[0029] In some embodiments, the heat insulation layer is located on the side of the cover plate or the housing facing the electrode assembly.

[0030] In some embodiments, the insulation layer is disposed on the housing, and the insulation layer is spaced apart from the cover plate.

[0031] In this embodiment, a gap is reserved between the heat insulation layer and the cover plate, so that the shell and the cover plate can be easily sealed by welding when sealing the shell, reducing the processing difficulty.

[0032] In some embodiments, the material of the insulation layer is at least one of the following: aerogel material, ceramic material, asbestos, rock wool or mica material.

[0033] In some embodiments, the thickness of the insulation layer ranges from [0.1 mm to 0.5 mm].

[0034] In a second aspect, a battery device is provided, comprising: a plurality of battery cells, wherein the battery cells are as described in the first aspect and any embodiment thereof.

[0035] Thirdly, an electrical device is provided, including a battery device comprising a battery cell as described in the first aspect and any embodiment thereof, the battery device being used to supply power to the electrical device. Attached Figure Description

[0036] Figure 1 shows a schematic diagram of the structure of a vehicle according to an embodiment of this application;

[0037] Figure 2 shows a schematic diagram of the structure of a battery device according to an embodiment of this application;

[0038] Figure 3 shows a schematic diagram of the structure of a battery cell according to an embodiment of this application;

[0039] Figure 4 shows a schematic diagram of the structure of the outer casing according to an embodiment of this application;

[0040] Figure 5 shows a schematic diagram of the structure of the housing according to an embodiment of this application;

[0041] Figure 6 shows a schematic diagram of the structure of a battery cell according to an embodiment of this application;

[0042] Figure 7 shows a schematic diagram of the structure of the housing according to an embodiment of this application;

[0043] Figure 8 shows a schematic diagram of the structure of a battery cell according to an embodiment of this application;

[0044] Figure 9 shows a schematic diagram of the structure of a battery cell according to an embodiment of this application;

[0045] Figure 10 shows a schematic diagram of the structure of a battery cell according to an embodiment of this application;

[0046] Figure 11 shows a schematic diagram of the structure of the outer casing according to an embodiment of this application;

[0047] Figure 12 shows a schematic diagram of the structure of the casing according to an embodiment of this application;

[0048] Figure 13 shows a schematic diagram of the structure of the housing according to an embodiment of this application;

[0049] Figure 14 shows a schematic diagram of the structure of the housing according to an embodiment of this application;

[0050] Figure 15 shows a schematic diagram of temperature change of the insulation layer according to an embodiment of this application;

[0051] Figure label:

[0052] 1-Vehicle; 10-Battery unit; 20-Battery cell; 30-Controller; 40-Motor; 11-Box; 111-First box section; 112-Second box section; 1000-Outer shell; 100-Housing shell; 200-Cover plate; 50-Pressure relief mechanism; 60-Electrode assembly; 70-Electrode terminal; 1011-Weld; 300-Reinforcing structure; 400-Insulation layer; 301-First wall; 302-Second wall; 303-First part; 304-Second part. Detailed Implementation

[0053] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0054] 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.

[0055] 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.

[0056] In this application, the reference to "embodiment" means that a specific 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 throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0057] 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.

[0058] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0059] 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.

[0060] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0061] In this embodiment of the application, the battery cell can be a secondary battery device, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0062] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., but the embodiments of this application are not limited to this.

[0063] In some implementations, the battery cell in this application embodiment can be a metal battery. Specifically, the metal battery may include lithium metal secondary batteries, sodium metal batteries, or magnesium metal batteries, etc. This application embodiment does not limit this.

[0064] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0065] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0066] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0067] As an example, the positive electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0068] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for battery devices 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 manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0069] In some embodiments, the negative electrode may be a negative electrode sheet, which may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0070] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0071] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, or foamed carbon, etc. Composite current collectors 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.).

[0072] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0073] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0074] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride, and ceramic.

[0075] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0076] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0077] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0078] The battery device mentioned in the embodiments of this application may include a single physical module containing one or more battery cells to provide higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, parallel, or mixed via a busbar. Mixed connection refers to a combination of series and parallel connections.

[0079] In some embodiments, the battery device can be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing. For example, multiple individual battery cells can first be connected in series, parallel, or a combination of these connections to form a battery module, and then multiple battery modules can be connected in series, parallel, or a combination of these connections to form the battery device. That is, multiple individual battery cells can directly form the battery device, or they can first be connected in series to form a battery module, and then the battery modules can be connected in series to form the battery device.

[0080] 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.

[0081] In some embodiments, the battery device may be located within an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0082] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices.

[0083] 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. This application does not impose any special limitations on the above-mentioned electrical equipment.

[0084] The application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage 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. With the continuous expansion of the application fields of power batteries, battery performance is becoming increasingly powerful, while simultaneously placing higher demands on the stability and durability of power batteries. Currently, traditional power batteries, due to the relatively intense heat and gas generation reactions within the battery cells, urgently require improvements in the tensile strength and durability of the battery casing itself.

[0085] This application provides a battery cell, a battery device, and an electrical appliance. The battery cell includes a shell, which includes a housing with a metal layer and a cover plate. The housing is a hollow structure with a first opening, and the cover plate is disposed on the first opening. The housing and the cover plate are connected. An electrode assembly is housed in the hollow structure. The shell also includes a reinforcing structure, which is laminated and connected to the housing and / or the cover plate. The tensile strength of the reinforcing structure is greater than or equal to the tensile strength of the housing and the cover plate.

[0086] By reinforcing the surface of the metal layers in the casing and / or the cover plate, the tensile strength of the casing can be increased, enhancing its resistance to deformation and improving its stability. Strengthening the casing of individual battery cells protects the internal electrochemical system, preventing leakage of active materials and significantly improving the safety of the battery device. Furthermore, the reinforced casing reduces damage to the battery from mechanical shock or vibration during transportation and use, extending battery life and improving its reliability and durability.

[0087] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0088] Figure 1 shows a schematic diagram of the structure of a vehicle 1 according to one embodiment of this application. As shown in Figure 1, vehicle 1 can be a gasoline vehicle, a natural gas vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A motor 40, a controller 30, and a battery device 10 can be installed inside vehicle 1. The controller 30 is used to control the battery device 10 to supply power to the motor 40. For example, the battery device 10 can be installed at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to power vehicle 1. For example, the battery device 10 can serve as the operating power source for vehicle 1, for example, to meet the electrical system requirements of vehicle 1, such as for starting, navigation, and operation. In another embodiment of this application, the battery device 10 can not only serve as the operating power source for vehicle 1, but also as the driving power source for vehicle 1, replacing or partially replacing gasoline or natural gas to provide driving power for vehicle 1.

[0089] Figure 2 shows a schematic diagram of the structure of a battery device 10 according to an embodiment of this application. As shown in Figure 2, the battery device 10 of this embodiment may include multiple battery cells 20 to meet different power usage requirements. The shape of the battery cell 20 in this embodiment can be set according to actual application. For example, the battery cell 20 can be a cuboid as shown in Figure 2, or it can be a cylinder or other shape different from that shown in Figure 2. This embodiment is not limited to this.

[0090] It should be understood that, as shown in FIG. 2, the battery device 10 of this embodiment may further include a housing 11, which can be used to accommodate multiple battery cells 20. The housing 11 of this embodiment has a hollow internal structure, and the multiple battery cells 20 are accommodated within the housing 11. The housing 11 may include two parts, referred to herein as a first housing portion 111 and a second housing portion 112, which are fastened together. The shapes of the first housing portion 111 and the second housing portion 112 can be determined according to the shape of the components housed inside, for example, according to the shape of the combination of the multiple battery cells 20 housed inside. At least one of the first housing portion 111 and the second housing portion 112 has a first opening. For example, as shown in Figure 2, the first housing portion 111 and the second housing portion 112 can both be hollow cuboids with one face as a first opening. The first opening of the first housing portion 111 and the first opening of the second housing portion 112 are arranged opposite to each other, and the first housing portion 111 and the second housing portion 112 are interlocked to form a housing 11 with a closed cavity, which can be used to accommodate multiple battery cells 20. The multiple battery cells 20 are connected in parallel, series, or mixed and placed inside the housing 11 formed by the interlocking of the first housing portion 111 and the second housing portion 112.

[0091] For example, unlike what is shown in Figure 2, the first housing portion 111 and the second housing portion 112 may each have only one hollow cuboid with a first opening, while the other is plate-shaped to cover the first opening. Taking the second housing portion 112 as a hollow cuboid with a first opening, and the first housing portion 111 as a plate-shaped example, then the first housing portion 111 covers the first opening of the second housing portion 112 to form a housing 11 with a closed chamber, which can be used to accommodate multiple battery cells 20.

[0092] In some embodiments, the battery device 10 may further include other components. For example, the battery device 10 may further include a busbar (not shown in the figure), which can be used to realize electrical connections between multiple battery cells 20, such as in parallel, series, or mixed connections. Specifically, the busbar can realize electrical connections between battery cells 20 by connecting to the electrode terminals 70 of the battery cells 20; or, the busbar can also realize electrical connections between battery cells 20 by connecting to other components of the battery cells 20. The busbar can be fixed to corresponding components of the battery cells 20 by welding, for example, by welding to the electrode terminals 70 or the housing 1000, etc., but the embodiments of this application are not limited thereto.

[0093] Figure 3 is a schematic diagram of a battery cell 20 provided in an embodiment of this application. As shown in Figure 3, the battery cell 20 includes a housing 1000, which is used to encapsulate electrode components 60 and electrolytes, etc. The housing 1000 includes a shell 100 with a metal layer and a cover plate 200. The shell 100 is a hollow structure with a first opening. The cover plate 200 is placed over the first opening and forms a sealed connection with the shell 100. One or more electrode components 60 can be placed inside the hollow structure. In this battery cell 20, depending on actual usage requirements, the electrode components 60 can be single or multiple. The electrode components 60 can be a wound structure or a stacked structure, and this embodiment of the application is not limited to these.

[0094] The housing 1000 can be shaped according to the combination of one or more electrode components 60, for example, the housing 1000 can be a cuboid, cube or cylinder.

[0095] As shown in Figure 3, the battery cell 20 also includes two electrode terminals 70, which may be disposed on the cover plate 200. The electrode terminals 70 are located on the surface of the cover plate 200 and pass through the cover plate 200. The electrode terminals 70 include a positive electrode terminal 70 and a negative electrode terminal 70. Each electrode terminal 70 is provided with a corresponding connecting member, which may also be a current collector or a copper-aluminum adapter piece, located between the cover plate 200 and the electrode assembly 60.

[0096] In this embodiment, as shown in FIG3, the battery cell 20 further includes a pressure relief mechanism 50, which can be disposed on the cover plate 200 and sealed to the metal layer of the cover plate 200. The pressure relief mechanism 50 is actuated to release the internal pressure when the internal pressure of the casing 1000 reaches a threshold. Under normal conditions, the pressure relief mechanism 50, as part of the battery cell 20, forms a sealed, airtight space with the casing 1000. However, when the battery cell 20 produces too much emissions, the emissions expand, causing the internal pressure of the battery cell 20 to rise above a preset value. In this case, the pressure relief mechanism 50 can rupture, allowing communication between the inside and outside of the battery cell 20. The emissions are released outward through the rupture in the pressure relief area, thereby reducing the possibility of an explosion.

[0097] Figure 4 is a structural schematic diagram of the housing 1000 applicable to an embodiment of this application. As shown in Figure 4, the metal layer of the housing 100 and the metal layer of the cover plate 200 are connected to form a weld 1011. The housing 1000 also includes a reinforcing structure 300, which is laminated and connected to the housing 100 and / or the cover plate 200. The tensile strength of the reinforcing structure 300 is greater than or equal to the tensile strength of the housing 100 and the cover plate 200.

[0098] In some embodiments, the reinforcing structure 300 is made of carbon fiber resin composite material. The reinforcing structure 300 and the shell 100 and / or cover plate 200 can be connected by resin thermosetting. For example, the reinforcing structure 300 can be directly thermoset and applied to the surface of the metal layer, or the carbon fiber can be woven into a three-dimensional structure and fitted onto the surface of the metal layer, and then thermoset and connected to the metal layer by heating the resin.

[0099] In some embodiments, Table 1 provides the tensile strength corresponding to different thicknesses of the reinforcing structure 300 when the material of the reinforcing structure 300 is a carbon fiber resin composite material.

[0100] Table 1. Thickness and tensile strength of reinforced structure 300

[0101] Referring to Table 1, the range of the first threshold is [200MPa, 2500MPa]. For example, the tensile strength of the reinforcing structure 300 is 200MPa, 500MPa, 800MPa, 1000MPa, 1500MPa, 2000MPa or 2500MPa, or the tensile strength of the reinforcing structure 300 is greater than 200MPa. The embodiments of this application are not limited to this.

[0102] In some embodiments, the thickness of the heating structure is in the range of [0.1mm, 0.5mm]. For example, the thickness of the heating structure can be 0.1mm, 0.2mm, 0.4mm or 0.5mm, and the embodiments of this application are not limited thereto.

[0103] By setting the thickness range and tensile strength of the reinforcing structure 300, it is possible to ensure that the reinforcing structure 300 meets sufficient strength performance while minimizing its occupation of the internal space of the battery device, thereby optimizing the energy density of the battery device.

[0104] This embodiment of the application, by connecting a reinforcing structure 300 to the surface of the metal layer of the housing 100 and / or the metal layer of the cover plate 200, enables the housing 1000 to better maintain its integrity and prevents safety hazards caused by the breakage of the housing 1000. By enhancing the performance of the housing 1000 of the battery cell 20, the internal electrochemical system of the battery can be protected, preventing leakage of active materials, thereby significantly improving the safety performance of the battery device. In addition, the reinforced housing 1000 can also reduce damage to the battery caused by mechanical shock or vibration during transportation and use, extend the battery's service life, and improve its reliability and durability.

[0105] Figures 4 and 5 show schematic diagrams of the structure of the housing 1000 applicable to embodiments of this application.

[0106] For example, as shown in Figure 4, the reinforcing structure 300 is disposed on the side of the housing 100 away from the electrode assembly 60, and the reinforcing structure 300 is stacked and connected to the housing 100.

[0107] For example, as shown in Figure 5, the reinforcing structure 300 is disposed on the side of the housing 100 and the cover plate 200 away from the electrode assembly 60. The reinforcing layer is connected to the side of the housing 100 and the side of the cover plate 200. The reinforcing structure 300 can continuously cover at least a portion of the weld 1011 formed by the connection between the housing 100 and the cover plate 200. That is, in the area where the weld 1011 is located, the reinforcing structure 300 can be a continuous integral structure.

[0108] Weld 1011 is the weakest area of ​​the outer shell 1000. By covering weld 1011 with reinforcement structure 300, the reliability of the shell can be further improved.

[0109] In some possible embodiments, the reinforcing structure 300 may cover the entire weld 1011.

[0110] In some embodiments, as shown in FIG5, there may be a certain vertical distance d1 between the end of the reinforcing structure 300 on the housing 100 that is away from the cover plate 200 and the bottom surface of the housing 100. The bottom surface is the side of the housing 100 opposite to the first opening. The vertical distance d1 may be in the range of [1mm, 50mm], but the embodiments of this application are not limited to this.

[0111] For example, Figure 6 is a structural schematic diagram of a battery cell 20 provided in an embodiment of this application. As shown in Figure 6, the reinforcing structure 300 is disposed on the side of the housing 100 and the cover plate 200 away from the electrode assembly 60, and the reinforcing layer is connected to the cover plate 200 and the side of the housing 100.

[0112] In some embodiments, as shown in FIG. 6, the reinforcing structure 300 may have a second opening. The reinforcing structure 300 includes a first wall 301 and at least one second wall 302 opposite to the second opening. The first wall 301 and the second wall 302 enclose a receiving cavity. The first wall 301 is stacked with the cover plate 200, and the second wall 302 is stacked with the housing. For example, the reinforcing structure 300 may be fitted onto the cover plate 200 and the housing 100 in a direction perpendicular to the cover plate 200, such that the weld 1011 can be accommodated in the receiving cavity. The direction perpendicular to the cover plate 200 is, for example, the z-axis shown in FIG. 6.

[0113] In some possible embodiments, the cover plate 200 may be provided with electrode terminals and / or pressure relief mechanisms, and the first wall 301 is provided with through holes, which are arranged opposite to the electrode terminals 70 or pressure relief mechanisms 50 provided on the cover plate 200. By providing the reinforcing structure 300 as an integral structure that continuously covers the weld 1011, the strength of the weld 1011 area of ​​the outer casing 1000 can be enhanced, and the possibility of cracking of the outer casing 1000 in the weld 1011 area can be reduced.

[0114] For example, Figure 7 is a structural schematic diagram of a housing 1000 applicable to an embodiment of this application. As shown in Figure 7, a reinforcing structure 300 is also disposed on the bottom surface of the housing 100. The reinforcing structure 300 is located on the side of the housing 100 and the cover plate 200 away from the electrode assembly 60, and is connected to the housing 100 and the cover plate 200.

[0115] In some embodiments, as shown in FIG8, the reinforcing structure 300 is a split structure, comprising a first portion 303 and a second portion 304, which are respectively fitted onto the housing 1000. Exemplarily, the first portion 303 and the second portion 304 are fitted onto the housing 100 and the cover plate 200 respectively along opposite directions on the same axis (e.g., the x-axis shown in FIG8). The first portion 303 and the second portion 304 are connected to form a receiving cavity, and the weld 1011 is accommodated within the receiving cavity. The reinforcing structure 300 forms a continuous covering structure in the region of the weld 1011.

[0116] In some possible embodiments, the side of the first portion 303 or the second portion 304 facing the cover plate 200 is provided with a through hole, which is disposed opposite to the electrode terminal 70 or the pressure relief mechanism 50 disposed on the cover plate 200. By providing a continuous covering structure for the reinforcing structure 300 at the weld 1011, the strength of the weld 1011 area of ​​the outer shell 1000 can be enhanced, reducing the possibility of cracking of the outer shell 1000 in the weld 1011 area. The reinforcing structure 300 is divided into two parts, which is easier to process and completely covers the shell 100 and the cover plate 200, further enhancing the strength of the outer shell 1000.

[0117] For example, Figure 9 is a schematic diagram of the structure of a battery cell 20 provided in an embodiment of this application. As shown in Figure 9, both the first part 303 and the second part 304 include a top wall and a side wall. The top walls of the first part 303 and the second part 304 are arranged opposite to each other, and the side walls of the first part 303 and the second part 304 are connected. The top wall of the first part 303 or the second part 304 is stacked with the cover plate. Exemplarily, the first part 303 and the second part 304 can be respectively sleeved on the housing 100 and the cover plate 200 in a direction perpendicular to the cover plate 200 and opposite to each other (e.g., the z-axis shown in Figure 9). Compared with the reinforcing structure 300 in Figure 8, which is arranged opposite to each other along the x-axis, the gap at the connection between the first part 303 and the second part 304 of the reinforcing structure 300 provided in Figure 9 can be completely offset from the weld 1011, which can further enhance the strength of the area of ​​the weld 1011 of the housing 1000 and reduce the possibility of cracking of the housing 1000 in the area of ​​the weld 1011.

[0118] In some embodiments, the connection between the first part 303 and the second part 304 may partially overlap, thereby further preventing the area of ​​the weld 1011 of the housing 1000 from cracking during thermal runaway, enhancing the strength of the housing 1000, thereby achieving directional pressure relief of the battery cell 20 and improving the safety performance of the battery cell 20.

[0119] For example, as shown in Figure 10, the reinforcing structure 300 includes multiple parts, each of which is connected to a face in each direction of the housing 100 or the cover plate 200. The side of the reinforcing structure 300 connected to the cover plate 200 is provided with through holes corresponding to the electrode terminals 70 or the pressure relief mechanism 50 provided on the cover plate 200. This embodiment of the application does not specifically limit this aspect.

[0120] Figures 11 to 14 are schematic diagrams of the structure of the housing 1000 applicable to the embodiments of this application. As shown in Figures 11 to 14, the housing 1000 also includes a heat insulation layer 400, which is stacked and connected to the reinforcing structure 300, or stacked and connected to the cover plate 200, or stacked and connected to the shell 100. The heat insulation layer 400 is located on the side of the reinforcing structure 300 facing the electrode assembly 60.

[0121] For example, as shown in Figure 11, the heat insulation layer 400 and the reinforcing structure 300 are both disposed on the side of the housing 100 and / or the cover plate 200 away from the electrode assembly 60. The heat insulation layer 400 is located between the reinforcing structure 300 and the housing 1000. For example, the heat insulation layer 400 can be located between the reinforcing structure 300 and the housing 100 or the cover plate 200. By setting the heat insulation layer 400 and its position, the high temperature resistance of the housing 1000 can be effectively improved, and the overall strength of the housing 1000 can be enhanced. At the same time, the heat insulation layer 400 and the reinforcing structure 300 are both located on the outside of the housing 100 or the cover plate 200, which reduces the space occupied inside the battery cell 20 and makes it easier to process.

[0122] For example, as shown in Figure 12, the heat insulation layer 400 is disposed on the side of the housing 100 facing the electrode assembly 60, the reinforcing structure 300 is disposed on the side of the housing 100 away from the electrode assembly 60, and the metal layer is located between the heat insulation layer 400 and the reinforcing structure 300.

[0123] In some embodiments, as shown in FIG12, when the heat insulation layer 400 is located on the side of the housing 100 facing the electrode assembly 60, the heat insulation layer 400 needs to reserve a certain distance for the metal layer of the housing 100 and the metal layer of the cover plate 200 to be welded and sealed. Before the metal layer of the housing 100 and the metal layer of the cover plate 200 are welded, the reserved distance d2 from the end of the heat insulation layer 400 on the housing 100 facing the first opening to the first opening is in the range of [1mm, 5mm]. For example, the reserved distance d2 can be 1mm, 1.5mm, 2mm, 3mm, 4mm or 5mm, etc., but the embodiments of this application are not limited to this.

[0124] In some embodiments, as shown in FIG13, when the heat insulation layer 400 is located on the side of the housing 100 facing the electrode assembly 60, the metal layer of the housing 100 is welded to the metal layer of the cover plate 200.

[0125] In some possible embodiments, the heat insulation layer 400 may be disposed on the housing 100, and the heat insulation layer 400 and the cover plate 200 may be disposed at intervals.

[0126] In some embodiments, as shown in FIG14, both the reinforcing structure 300 and the heat insulation layer 400 are located on the side of the housing 100 facing the electrode assembly 60, and the reinforcing structure 300 is located between the housing 100 and the heat insulation layer 400.

[0127] In some embodiments, when the heat insulation layer 400 is located on the side of the metal layer facing the electrode assembly 60, the material of the heat insulation layer 400 satisfies the requirement of resistance to electrolyte corrosion, or the side of the heat insulation layer 400 facing the electrode assembly 60 is connected to a material resistant to electrolyte corrosion. This embodiment does not specifically limit this aspect.

[0128] In some embodiments, the material of the insulation layer 400 has high-temperature resistance. For example, Figure 15 is a temperature change diagram of both sides of the insulation layer 400 when a heat source is applied to it. As shown in Figure 15, when a heat source of 1000°C is applied to one side of the insulation layer 400, and the temperature of both sides of the insulation layer 400 is monitored within 60 seconds, the temperature of the side of the insulation layer 400 closer to the heat source is 1000°C, and the temperature of the side of the insulation layer 400 farther from the heat source is less than 300°C. The material of the insulation layer 400 can meet the insulation requirements.

[0129] In some embodiments, the material of the insulation layer 400 is at least one of the following materials: aerogel material, ceramic material, asbestos, rock wool or mica material.

[0130] In some embodiments, the thickness of the insulation layer 400 is in the range of [0.1mm, 0.5mm]. For example, the thickness of the insulation layer 400 can be 0.1mm, 0.2mm, 0.4mm or 0.5mm, but this embodiment is not limited to this.

[0131] This embodiment of the application can effectively improve the heat insulation performance of the outer shell 1000 by providing a heat insulation layer 400 on the outer shell 1000. In extreme cases such as thermal runaway, it can protect the metal layer and the reinforcing structure 300 from high temperature damage and effectively protect the strength and stability of the outer shell 1000 in high temperature environment.

[0132] In some embodiments, the metal layer is made of aluminum or stainless steel, but this application is not limited to this.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. 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 outer shell (1000) includes a shell (100) with a metal layer and a cover plate (200). The shell (100) is a hollow structure with a first opening. The cover plate (200) covers the first opening. The shell (100) is connected to the cover plate (200). Electrode assembly (60), said electrode assembly (60) being housed in the hollow structure; The outer shell (1000) further includes a reinforcing structure (300), which is stacked and connected to the shell (100) and / or the cover plate (200). The tensile strength of the reinforcing structure (300) is greater than or equal to the tensile strength of the shell (100) and the cover plate (200).

2. The battery cell according to claim 1, characterized in that, The reinforcing structure (300) is disposed on the side of the cover plate (200) or the housing (100) away from the electrode assembly (60).

3. The battery cell according to claim 1 or 2, characterized in that, A weld (1011) is formed at the connection between the housing (100) and the cover plate (200), and the reinforcing structure (300) covers at least a portion of the weld (1011).

4. The battery cell according to claim 3, characterized in that, The reinforcing structure (300) covers the entire weld (1011).

5. The battery cell according to claim 3, characterized in that, The reinforcing structure (300) has a second opening. The reinforcing structure (300) includes a first wall (301) and at least one second wall (302) opposite to the second opening. The first wall (301) and the second wall (302) enclose a receiving cavity. The first wall (301) is stacked with the cover plate (200), and the second wall is stacked with the shell. The weld (1011) is accommodated in the receiving cavity.

6. The battery cell according to claim 5, characterized in that, The cover plate (200) is provided with electrode terminals and / or pressure relief mechanism, and the first wall is provided with through hole, which is disposed opposite to the electrode terminals and / or the pressure relief mechanism.

7. The battery cell according to claim 3, characterized in that, The reinforcing structure (300) includes a first part (303) and a second part (304), the first part (303) and the second part (304) are respectively sleeved on the outer shell (1000), the first part (303) and the second part (304) are connected to form a receiving cavity, and the weld (1011) is accommodated in the receiving cavity.

8. The battery cell according to claim 7, characterized in that, The first part (303) and / or the second part (304) have through holes on the side facing the cover plate (200), and the through holes are disposed opposite to the electrode terminals or pressure relief mechanisms disposed on the cover plate (200).

9. The battery cell according to claim 7, characterized in that, Both the first part (303) and the second part (304) include a top wall and a side wall. The top walls of the first part (303) and the second part (304) are arranged opposite to each other. The side walls of the first part (303) and the second part (304) are connected. The top wall of the first part (303) or the second part (304) is stacked with the cover plate.

10. The battery cell according to any one of claims 1 to 9, characterized in that, The reinforcing structure (300) is made of carbon fiber resin composite material.

11. The battery cell according to any one of claims 1 to 10, characterized in that, The thickness of the reinforcing structure (300) ranges from [0.1 mm to 0.5 mm].

12. The battery cell according to any one of claims 1 to 11, characterized in that, The range of the first threshold is [200MPa, 2500MPa].

13. The battery cell according to any one of claims 1 to 12, characterized in that, The outer casing (1000) further includes a heat insulation layer (400), which is stacked and connected to the reinforcing structure (300), the cover plate (200) or the housing (100), and the heat insulation layer (400) is located on the side of the reinforcing structure (300) facing the electrode assembly (60).

14. The battery cell according to claim 13, characterized in that, The heat insulation layer (400) is located between the reinforcing structure (300) and the outer shell.

15. The battery cell according to claim 13, characterized in that, The heat insulation layer (400) is located on the side of the cover plate (200) or the housing (100) facing the electrode assembly (60).

16. The battery cell according to claim 13, characterized in that, The heat insulation layer (400) is disposed on the housing (100), and the heat insulation layer (400) is spaced apart from the cover plate (200).

17. The battery cell according to any one of claims 13 to 16, characterized in that, The material of the insulation layer (400) is at least one of the following: aerogel material, ceramic material, asbestos, rock wool or mica material.

18. The battery cell according to any one of claims 13 to 17, characterized in that, The thickness of the insulation layer (400) ranges from [0.1 mm to 0.5 mm].

19. A battery device, characterized in that, include: Multiple battery cells, wherein the battery cells are battery cells as described in any one of claims 1-18.

20. An electrical appliance, characterized in that, include: A battery device comprising a battery cell as described in any one of claims 1-18, the battery device being used to supply power to the electrical device.

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