Battery apparatus and electrical device

Abstract

The present application discloses a battery apparatus (100) and an electrical device (200). A U-shaped encapsulating shell (21) is bonded to a housing (10) via an adhesive layer (12). A busbar support (23) is disposed on the U-shaped encapsulating shell (21) and is connected to the U-shaped encapsulating shell (21) via a connecting portion (231). The U-shaped encapsulating shell (21) is provided with a pressure relief portion (2111). A shear strength of the connecting portion (231) is greater than a first preset value, the first preset value being greater than or equal to 0.1 Mpa. An adhesive strength of the adhesive layer (12) is greater than a second preset value, the second preset value being greater than or equal to 1 Mpa.

Description

Battery devices and electrical equipment Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery device and an electrical appliance. Background Technology

[0002] In related technologies, the high difficulty of directional pressure relief for individual pouch battery cells hinders further improvement in the reliability of pouch battery devices. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. Therefore, one objective of this application is to provide a battery device and an electrical appliance that can stably achieve directional pressure relief, resulting in higher reliability.

[0004] This application provides a battery device, including: a housing and a battery pack. The battery pack includes a U-shaped housing, multiple pouch cells, and a current collector bracket. The U-shaped housing is bonded to the housing with an adhesive layer. The current collector bracket is disposed on the U-shaped housing and connected to it via a connecting portion. The U-shaped housing, the housing, and the current collector bracket together form a receiving space. Multiple pouch cells are disposed within the receiving space and electrically connected via the current collector bracket. The U-shaped housing has a pressure relief portion, the shear strength of the connecting portion is greater than a first preset value (greater than or equal to 0.1 MPa), and the adhesive strength of the adhesive layer is greater than a second preset value (greater than or equal to 1 MPa).

[0005] According to the battery device of the present application embodiment, by making the shear strength of the connection part greater than a first preset value and the adhesive strength of the adhesive layer greater than a second preset value, when thermal runaway occurs inside the battery pack, the pressure relief part can be preferentially broken to release pressure in a directional manner. During the directional pressure relief process, the probability of connection failure between the connection part and the U-shaped cover shell, and between the U-shaped cover shell and the adhesive layer is lower, so as to improve the reliability and stability of directional pressure relief, thereby improving the reliability of the battery device.

[0006] According to some embodiments of this application, the U-shaped enclosure includes: a first plate forming a pressure relief portion and a second plate located on both sides of the first plate, and a manifold bracket located at both ends of the length of the U-shaped enclosure, with the connecting portion connected to the first plate and / or the second plate.

[0007] According to some embodiments of this application, the connecting portion includes a plug post, and the connecting portion is inserted into a slot formed on a first plate and / or a second plate.

[0008] According to some embodiments of this application, the orthographic projection size of the plug towards the slot is larger than the opening size of the slot, so that the plug and the slot are in an interference fit.

[0009] According to some embodiments of this application, the projected size of the plug pin facing the slot is 0.2 mm to 1 mm larger than the opening size.

[0010] According to some embodiments of this application, the connecting portion includes an overlapping plate, which is connected to a first plate and / or a second plate.

[0011] According to some embodiments of this application, the overlap size of the overlapping plate with the first plate and / or the second plate is in the range of 1mm-5mm.

[0012] According to some embodiments of this application, the overlapping plate is glued, welded or screwed to the first plate and / or the second plate.

[0013] According to some embodiments of this application, the connecting portion includes a first snap-fit ​​structure, a first plate, and / or a second plate having a second snap-fit ​​structure formed at its long end that snaps into the first snap-fit ​​structure.

[0014] According to some embodiments of this application, the busbar bracket further includes: an insulating body and a sealing portion, the sealing portion being located between the insulating body and the pouch battery cell, a connecting portion being disposed on the insulating body, a first groove and a second groove being formed on the insulating body, the first groove being located on the side surface of the insulating body facing the pouch battery cell, the second groove being located on the adjacent side surface of the insulating body and penetrating the insulating body, the first groove and the second groove being connected, and the first groove being adapted to accommodate the tab, and the second groove being adapted to accommodate the busbar being electrically connected to the tab.

[0015] According to some embodiments of this application, when the energy density of a single soft-pack battery cell is 450Wh / L to 600Wh / L, the shear strength of the connection between the connector and the casing is 0.1Mpa to 0.2Mpa, and the adhesive strength of the adhesive layer is 1Mpa to 2.5Mpa.

[0016] When the energy density of a single soft-pack battery cell is 600Wh / L to 700Wh / L, the shear strength of the connection between the connector and the casing is 0.2MPa to 0.3MPa, and the adhesive strength of the adhesive layer is 2.5MPa to 5.5MPa.

[0017] When the energy density of a single soft-pack battery cell is greater than 700Wh / L, the shear strength of the connection and the connection strength of the casing are 0.3MPa to 0.5MPa, and the adhesive strength of the adhesive layer is 5.5MPa to 10.5MPa.

[0018] According to some embodiments of this application, there are multiple pressure relief sections, which are spaced apart along the length and / or width of the first plate.

[0019] According to some embodiments of this application, the first plate is constructed as a flat plate or an arc-shaped plate.

[0020] According to some embodiments of this application, a pouch cell includes: a flexible housing and an electrode assembly disposed within the flexible housing. The flexible housing has a side surface opposite to the large surface of the electrode assembly and a circumferential surface avoiding the large surface. A second plate is opposite to the side surface.

[0021] According to some embodiments of this application, the projected profile area of ​​the second plate facing the side of the flexible shell is less than or equal to the area of ​​the side.

[0022] According to some embodiments of this application, a pressure relief weak portion is formed on the circumferential surface, the weak pressure relief portion is opposite to the first plate, and the pressure relief portion and the weak portion are at least partially opposite to each other.

[0023] According to some embodiments of this application, the first plate is spaced apart from the side of the circumferential surface that has a weak pressure relief portion to define an exhaust passage.

[0024] According to some embodiments of this application, the U-shaped cladding shell is constructed of aluminum or stainless steel.

[0025] According to some embodiments of this application, the end face of the soft-pack battery cell away from the first plate is connected to the casing by an adhesive layer.

[0026] According to some embodiments of this application, the housing has a bottom plate, which is connected to the individual soft-pack battery cells via an adhesive layer.

[0027] According to some embodiments of this application, the base plate includes a cold plate, and an adhesive layer is located between the cold plate and a plurality of pouch cell units.

[0028] According to some embodiments of this application, the adhesive layer includes: an adhesive layer body and an overflow portion, the overflow portion being located on the side of the adhesive layer body facing a plurality of pouch cell units, and located between adjacent pouch cell units, and / or between the pouch cell unit and the second plate.

[0029] According to some embodiments of this application, the soft-pack battery cell is any one of lithium iron phosphate battery cell, ternary lithium battery cell, and solid-state battery cell.

[0030] According to some embodiments of this application, when the battery cell is a lithium iron phosphate battery cell, the ratio of positive electrode active material, positive electrode binder and positive electrode conductive agent in the positive electrode material of the battery cell is 96:1-3:1-3; when the battery cell is a ternary lithium battery cell, the ratio of positive electrode active material, positive electrode binder and positive electrode conductive agent in the positive electrode material of the battery cell is 96:2-3:1-2.

[0031] This application provides an electrical device, including the battery device described in the above embodiments.

[0032] According to some embodiments of this application, the electrical equipment is a vehicle.

[0033] According to some embodiments of this application, the battery device is integrated into the vehicle chassis, and the top cover of the housing participates in defining the vehicle floor.

[0034] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0035] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0036] Figure 1 is a schematic diagram of an electrical device according to an embodiment of this application;

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

[0038] Figure 3 is a schematic diagram of a battery pack according to a first embodiment of this application;

[0039] Figure 4 is another schematic diagram of a battery pack according to the first embodiment of this application;

[0040] Figure 5 is a schematic diagram of a manifold support according to the first embodiment of this application;

[0041] Figure 6 is a schematic diagram of a battery pack according to a second embodiment of this application;

[0042] Figure 7 is another schematic diagram of a battery pack according to a second embodiment of this application;

[0043] Figure 8 is a schematic diagram of a manifold support according to a second embodiment of this application;

[0044] Figure 9 is a schematic diagram of a battery pack according to a third embodiment of this application;

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

[0046] Figure 11 is a schematic diagram of the cooperation between the U-shaped casing and the battery cell according to an embodiment of this application;

[0047] Figure 12 is a schematic diagram of the cooperation between the housing and the battery pack according to an embodiment of this application. Detailed Implementation

[0048] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0049] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0050] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more.

[0051] A single battery cell can be a rechargeable battery. A rechargeable battery is a battery cell that can be recharged after it has been discharged, allowing the active materials to be activated and the cell to continue to be used.

[0052] 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., and the embodiments of this application are not limited to this.

[0053] The battery device mentioned in the embodiments of this application may include one or more battery packs for providing voltage and capacity. The battery pack may include multiple individual battery cells, which are connected in series, parallel, or mixed connections via a busbar support.

[0054] In some embodiments, the battery pack is typically formed by arranging multiple battery cells.

[0055] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more battery packs housed within the housing.

[0056] As an example, the battery pack can be housed in a housing by being fixed inside the housing.

[0057] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the battery pack. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0058] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the battery pack.

[0059] 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.

[0060] The technical solutions described in the embodiments of this application are applicable to battery devices and electrical equipment using battery devices.

[0061] 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.

[0062] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0063] Please refer to Figure 1, which is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. A battery device 100 is installed inside the vehicle, and the battery device 100 can be located at the bottom, front, or rear of the vehicle. The battery device 100 can be used to power the vehicle; for example, the battery device 100 can serve as the vehicle's operating power source.

[0064] The vehicle may also include a controller 400 and a motor 300. The controller 400 controls the battery device 100 to supply power to the motor 300, which serves as a load, for example, for the power needs of the vehicle during starting, navigation and driving.

[0065] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle, but also as the driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0066] Please refer to Figure 2, which is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 includes a housing 10 for housing individual battery cells.

[0067] The housing 10 is a component that houses individual battery cells and provides placement space for the battery pack 20. The housing 10 can adopt various structures. In some embodiments, the housing 10 may include a tray and a cover, which overlap to define a placement space for accommodating the individual battery cells. The tray and cover can be of various shapes, such as cuboids, cylinders, etc. The tray can be a hollow structure open on one side, and the cover can also be a hollow structure open on one side, with the open side of the cover overlapping the open side of the tray, thus forming a housing 10 with placement space. Alternatively, the tray can be a hollow structure open on one side, and the cover can be a plate-like structure, with the cover overlapping the open side of the tray, thus forming a housing 10 with placement space.

[0068] In the battery device 100, there can be one or more battery cells. Multiple battery cells are loaded into a battery pack 20 by a U-shaped casing 21. One or more battery packs 20 are loaded into the housing 10. If there are multiple battery cells, they can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells are connected in both series and parallel. It is possible that multiple battery cells are first connected in series, parallel, or in a mixed manner to form a battery pack 20, and then multiple battery packs 20 are connected in series, parallel, or in a mixed manner to form a whole, which is housed in the housing 10.

[0069] The battery cell serves as the smallest energy unit of the battery device 100. The battery cell includes a flexible housing 221 and an electrode assembly 222 disposed within the flexible housing 221.

[0070] The internal environment formed by the flexible housing 221 can be used to accommodate the electrode assembly 222, electrolyte, and other components. An opening can be formed on one side of the flexible housing 221 for injecting electrolyte and for inserting the electrode assembly 222 into the housing.

[0071] Electrode terminals can be further disposed on the flexible casing 221. The electrode assembly 222 is the component in the battery cell where the electrochemical reaction occurs. The flexible casing 221 can contain one or more electrode assemblies 222. The electrode assembly 222 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets with active material constitute the main body of the electrode assembly 222, and the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs can be located at both ends of the main body. Busbar supports 23 are provided at both ends of the battery pack 20. During the charging and discharging process of the battery device 100, the positive and negative active materials react with the electrolyte, and the tabs connect to the busbar supports 23 to form a current loop.

[0072] The positive electrode sheet may include a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector, the positive electrode film layer including a positive electrode active material.

[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 electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, titanium, silver-surfaced aluminum, or stainless steel can be used. 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 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.).

[0075] As an example, when the pouch cell 22 in this embodiment is a lithium-ion battery, the positive electrode active material may include at least one of the following materials: phosphate, layered transition metal oxide, and their respective modified compounds; optionally, the positive electrode active material may include layered transition metal oxide and their respective modified compounds, which is beneficial to improving the energy density of the pouch cell 22. However, this application is not limited to these materials, and other conventional materials that can be used as the positive electrode film layer of a battery may also be used. These positive electrode active materials may be used alone or in combination of two or more.

[0076] Examples of phosphates may 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.

[0077] Layered transition metal oxides include those with the general formula Li a Ni b Co c M d O e A f At least one of the compounds and their modified compounds. 0.8 ≤ a ≤ 1.2, 0.3 ≤ b < 1, 0 < c < 1, 0 < d < 1, 1 ≤ e ≤ 2, 0 ≤ f ≤ 1, M includes at least one of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti, and B, and A includes at least one of N, F, S, and Cl. Optionally, 0.5 ≤ b < 1, and further optionally, 0.75 ≤ b ≤ 0.98.

[0078] Examples of layered transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, and lithium nickel cobalt manganese oxides (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 LiNi 0.9 Co 0.05 Mn 0.05 O2 (also known as Ni90), lithium nickel cobalt aluminum oxide (such as LiNi) 0.80 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0079] When the soft-pack battery cell 22 in this application embodiment is a sodium-ion battery, the positive electrode active material may include, but is not limited to, at least one of sodium-containing transition metal oxides, polyanionic materials (such as phosphates, fluorophosphates, pyrophosphates, sulfates, etc.), and Prussian blue materials.

[0080] As an example, positive electrode active materials for sodium-ion batteries may include NaFeO2, NaCoO2, NaCrO2, NaMnO2, NaNiO2, and NaNi 1 / 2 Ti 1 / 2 O2, NaNi 1 / 2 Mn 1 / 2 O2, Na 2 / 3 Fe 1 / 3 Mn 2 / 3 O2, NaNi 1 / 3 Co 1 / 3 Mn 1 / 3O2, NaFePO4, NaMnPO4, NaCoPO4, Prussian blue materials, with the general formula X p M' q (PO4) r O x Y 3-x At least one of the materials in general formula X. p M' q (PO4) r O x Y 3-x In the given information, 0 < p ≤ 4, 0 < q ≤ 2, 1 ≤ r ≤ 3, 0 ≤ x ≤ 2, X includes at least one of H+, Li+, Na+, K+ and NH4+, M' is a transition metal cation, optionally at least one of V, Ti, Mn, Fe, Co, Ni, Cu and Zn, and Y is a halide anion, optionally at least one of F, Cl and Br.

[0081] In the embodiments of this application, the modified compounds of the above-mentioned positive electrode active materials can be doped and / or surface coated to modify the positive electrode active materials, such as carbon coating modification, fast ion conductor coating modification, etc.

[0082] During the charging and discharging process, the soft-pack battery cell 22 undergoes the insertion and extraction of active ions such as Li, resulting in a different molar content of Li in the soft-pack battery cell 22 at different discharge states. In the examples of positive electrode active materials in this application, the molar content of Li refers to the initial state of the material, i.e., the state before feeding. When the positive electrode active material is applied to the battery system, the molar content of Li may change after charge-discharge cycles.

[0083] In the examples of positive electrode active materials in this application, the molar content of oxygen (O) is only a theoretical value. Oxygen release from the crystal lattice will cause the molar content of oxygen (O) to change. In reality, the molar content of oxygen (O) will fluctuate.

[0084] In this embodiment, the elemental content in the positive electrode active material is defined in a way known in the art and can be detected using equipment and methods known in the art. For example, referring to EPA 6010D-2014, it can be measured by inductively coupled plasma atomic emission spectrometry (ICP-OES, instrument model: Thermo ICAP7400). First, 0.4g of the positive electrode active material is weighed and 10ml (50% concentration) of aqua regia is added. Then, it is placed on a plate at 180℃ for 30min. After digestion on the plate, the volume is adjusted to 100mL, and quantitative testing is performed using the standard curve method.

[0085] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, a positive electrode film layer may or may not be provided on the surface of the foamed metal. As an example, lithium source material, potassium metal, or sodium metal may also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0086] In some embodiments, the positive electrode film layer may optionally include a positive electrode conductive agent. This application embodiment does not particularly limit the type of positive electrode conductive agent. As an example, the positive electrode conductive agent includes at least one selected from superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some embodiments, the mass percentage of the positive electrode conductive agent in the positive electrode film layer is ≤5 wt%.

[0087] In some embodiments, the positive electrode film layer may optionally include a positive electrode binder. This application embodiment does not impose any particular limitation on the type of positive electrode binder. As an example, the positive electrode binder may include at least one selected from polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resins. In some embodiments, the mass percentage of the positive electrode binder in the positive electrode film layer is ≤5 wt%.

[0088] The positive electrode film is typically formed by coating a positive electrode slurry onto a positive electrode current collector, followed by drying and cold pressing. The positive electrode slurry is usually formed by dispersing the positive electrode active material, optional conductive agent, optional binder, and any other components in a solvent and stirring until homogeneous. The solvent can be N-methylpyrrolidone (NMP), but is not limited to it.

[0089] In some embodiments, the negative electrode may be a negative electrode sheet, which 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, the negative electrode film layer including a negative electrode active material.

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

[0091] As an example, the negative electrode 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. 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 (copper, copper 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.).

[0092] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in pouch cell 22. As an example, the negative electrode active material may include at least one of the following materials: carbon materials (e.g., carbon materials include at least one of artificial graphite, natural graphite, soft carbon, and hard carbon), silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may include at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may include 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 films in batteries may also be used. These negative electrode films may be used alone or in combination of two or more.

[0093] In some embodiments, the negative electrode active material includes silicon, which may exist in the form of a silicon-based material, such as elemental silicon, silicon oxides, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The introduction of silicon can improve the energy density of the pouch cell 22.

[0094] In some embodiments, the mass content of silicon in the negative electrode film layer is from 1 wt% to 32 wt%, optionally from 2 wt% to 19 wt%, and further optionally from 6 wt% to 13 wt%. In the pouch cell 22 system, when the mass content of silicon is within the above range, the energy density of the pouch cell 22 can be improved.

[0095] In the embodiments of this application, the mass content of silicon in the negative electrode film layer has a meaning known in the art and can be detected using equipment and methods known in the art. For example, the negative electrode sheet can be immersed in a solvent such as water to separate the negative electrode active material from the negative electrode current collector, and the negative electrode active material can be obtained by filtration. The silicon content of the negative electrode active material can be obtained by using an ICAP7400 inductively coupled plasma atomic emission spectrometer from Thermo Fisher Scientific, USA, in accordance with the GB / T30902-2014 standard.

[0096] In some embodiments, the negative electrode film layer may optionally include a negative electrode conductive agent. This application embodiment does not particularly limit the type of negative electrode conductive agent. As an example, the negative electrode conductive agent may include at least one selected from superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some embodiments, the mass percentage of the negative electrode conductive agent in the negative electrode film layer is ≤5 wt%.

[0097] In some embodiments, the negative electrode film layer may optionally include a negative electrode binder. This application embodiment does not impose any particular limitation on the type of negative electrode binder. As an example, the negative electrode binder may include at least one of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, waterborne acrylic resins (e.g., polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS). In some embodiments, the mass percentage of the negative electrode binder in the negative electrode film layer is ≤5%.

[0098] In some embodiments, the negative electrode film may optionally include other additives. As an example, other additives may include thickeners, such as sodium carboxymethyl cellulose (CMC-Na), PTC thermistor materials, etc. In some embodiments, the mass percentage of other additives in the negative electrode film is ≤2 wt%.

[0099] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0100] In some embodiments, the separator includes 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.

[0101] This application does not impose any particular restrictions on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0102] In some embodiments, the material of the separator may include one or more of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may 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 may be the same or different, without particular limitation.

[0103] In some embodiments, the separator may include a porous base membrane and a coating disposed on at least one side of the porous base membrane, the coating including at least one of inorganic particles or organic particles.

[0104] Porous base membranes may include one or more of polyethylene and polypropylene.

[0105] Inorganic particles possess good heat resistance, which can improve the overall heat resistance of the separator. Within the operating voltage range of sodium-ion batteries, inorganic particles essentially do not undergo oxidation and reduction reactions with metal dendrites. In other words, inorganic particles are configured to prevent oxidation and reduction reactions with alkali metals and / or alkaline earth metals at the nominal voltage of sodium-ion batteries.

[0106] In some embodiments, the inorganic particles include one or more of boehmite γ-AlOOH, aluminum oxide Al2O3, aluminum hydroxide Al(OH)3, barium sulfate BaSO4, magnesium oxide MgO, magnesium hydroxide Mg(OH)2, calcium oxide CaO, cerium oxide CeO2, zirconium titanate SrTiO3, barium titanate BaTiO3, and magnesium fluoride MgF2.

[0107] In some embodiments, the organic particles include at least one of polystyrene, polyethylene, polyimide, melamine resin, phenolic resin, polypropylene, polyester (e.g., polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate), polyphenylene sulfide, polyarylamide, polyamide-imide, polyimide, copolymers of butyl acrylate and ethyl methacrylate, and mixtures thereof.

[0108] In some embodiments, the pouch cell 22 further includes an electrolyte.

[0109] During the charging and discharging process of a single battery cell, active ions repeatedly insert and extract between the positive and negative electrode plates, while the electrolyte acts as a conductor for these active ions. This application does not impose any particular restrictions on the type of electrolyte; it can be selected according to actual needs.

[0110] Electrolytes consist of electrolyte salts and solvents. The types of electrolyte salts and solvents are not specifically limited and can be selected according to actual needs.

[0111] In some embodiments, the electrolyte may optionally include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery performance, such as additives that improve battery overcharge performance, additives that improve battery high-temperature performance, and additives that improve battery low-temperature power performance.

[0112] For example, the additives include at least one of the following: cyclic carbonate compounds containing unsaturated bonds, sulfate compounds, sulfite compounds, sulfonyl lactone compounds, disulfonic acid compounds, nitrile compounds, aromatic compounds, isocyanate compounds, phosphonitrile compounds, acid anhydrides, cyclic acid anhydride compounds, phosphite compounds, phosphate compounds, borate esters, and carboxylic acid esters.

[0113] In related technologies, a pressure relief section 2111 is provided on the soft-pack battery cell 22 and the U-shaped casing 21 is provided with a pressure relief section 2111. The pressure relief section 2111 and the pressure relief section 2111 can realize directional pressure relief of the soft-pack battery cell 22 and the battery pack 20. However, during the directional pressure relief process, the connection area between the busbar support 23 and the U-shaped casing 21 is prone to failure under pressure, and the adhesive layer 12 between the battery pack 20 and the housing 10 is also prone to adhesion failure, resulting in the failure of the connection between the busbar support 23 and the U-shaped casing 21, which in turn leads to the failure of directional pressure relief, which can easily cause secondary damage and reduce the reliability of the battery pack 20.

[0114] Based on this, this application proposes a battery device 100 in which the connection strength between the U-shaped casing 21 and the busbar support 23 is greater than the structural strength of the pressure relief part 2111, and the shear strength of the connection part 231 is greater than a first preset value. The battery pack 20 and the housing 10 are bonded together by an adhesive layer 12, and the bonding strength is greater than a second preset value. When the pressure relief part 2111 is depressurized, the probability of connection failure between the U-shaped casing 21 and the busbar support 23, and between the U-shaped casing 21 and the housing 10 is reduced, thereby improving the stability and reliability of directional pressure relief, reducing secondary damage, and improving the reliability of the battery device 100.

[0115] The battery device 100 and the electrical appliance 200 according to embodiments of the present invention are described below with reference to Figures 1-12.

[0116] As shown in Figures 2, 11 and 12, this application provides a battery device 100, including: a housing 10 and a battery pack 20, wherein the battery pack 20 is disposed within the housing 10.

[0117] As shown in Figures 3, 6, and 9, the battery pack 20 includes a U-shaped casing 21, multiple pouch battery cells 22, and a busbar support 23. The U-shaped casing 21 is bonded to the housing 10 via an adhesive layer 12 (which can be configured as a structural joint). The busbar support 23 is disposed on the U-shaped casing 21 and connected to it via a connecting part 231. The U-shaped casing 21, the housing 10, and the busbar support 23 together form an accommodating space. The multiple pouch battery cells 22 are disposed within the accommodating space and are electrically connected via the busbar support 23.

[0118] Specifically, as shown in Figures 4, 6, and 10, the pouch battery cell 22 has tabs extending from both ends of its length. There are two current collector brackets 23, which are respectively located at both ends of the pouch battery cell 22 and electrically connected to the two tabs to achieve electrical connection between the pouch battery cell 22 and the outside world. The current collector brackets 23 are connected to the U-shaped casing 21 and define the accommodating space. The pouch battery cell 22 is placed in the accommodating space so that the periphery of the pouch battery cell 22 is supported and protected by the U-shaped casing 21 and the current collector brackets 23.

[0119] Furthermore, the U-shaped casing 21 has a pressure relief section 2111. When thermal runaway occurs in the soft-pack battery cell 22, the pressure relief section 2111 discharges the high-temperature and high-pressure gas and particulate matter (i.e., high-temperature gas flow) in the containment space. This enables directional pressure relief of the battery pack 20, allowing the battery pack 20 to be depressurized in the direction of the pressure relief section 2111, thereby achieving orderly pressure relief, reducing secondary damage to the insulation interface of the battery device 100, and slowing down the spread rate of thermal runaway.

[0120] It should be noted that the insulation interface of the battery device 100 includes: the insulation structure between adjacent soft-pack battery cells 22, the insulation structure between adjacent battery packs 20, and the insulation structure between the battery pack 20 and surrounding components. By achieving the orderly discharge of high-temperature gas flow, the impact on the insulation interface when the battery pack 20 is depressurized can be reduced, thereby reducing the probability of secondary damage and improving reliability.

[0121] It is understandable that if the connection strength between the connecting part 231 and the covering shell 21 is less than the structural strength of the pressure relief part 2111, when the soft-pack battery cell 22 experiences thermal runaway, when the high-pressure gas flow acts on the connecting part 231 or the connection area between the connecting part 231 and the U-shaped covering shell 21, the shear force that the connecting part 231 can withstand is less than the force of the high-pressure gas flow. This makes it easier for the connection between the connecting part 231 and the U-shaped covering shell 21 to fail, which is greater than the probability of the pressure relief part 2111 breaking and releasing pressure in a directional manner. This can easily lead to the failure of the directional pressure relief part 2111.

[0122] Similarly, the battery pack 20 is connected to the housing 10 by the adhesive layer 12. When thermal runaway occurs in the battery pack 20, the force generated by the high-pressure gas flow will push the U-shaped cover 21 to move away from the adhesive layer 12. When the adhesive force corresponding to the adhesive strength of the adhesive layer 12 is less than the force, the U-shaped cover 21 will detach from the adhesive layer 12, which will also cause the directional pressure relief of the pressure relief part 2111 to fail.

[0123] Based on this, this application ensures that the shear strength of the connecting part 231 is greater than a first preset value, which is greater than or equal to 0.1 MPa, and the adhesive strength of the adhesive layer 12 is greater than a second preset value, which is greater than or equal to 1 MPa. This allows the connection strength between the connecting part 231 and the U-shaped covering shell 21, as well as the shear strength of the connecting part 231 itself, to be greater than the structural strength of the pressure relief part 2111. At the same time, the adhesive force generated by the adhesive strength of the adhesive layer 12 is greater than the force exerted by the U-shaped covering shell 21 when thermal runaway occurs inside the battery pack 20. This ensures the connection stability between the connecting part 231 and the U-shaped covering shell 21, and the connection stability between the U-shaped covering shell 21 and the housing 10 when directional pressure relief is performed through the pressure relief part 2111. This reduces the probability of connection failure between the connecting part 231 and the U-shaped covering shell 21, and connection failure between the housing 10 and the battery pack 20, thereby improving the reliability and stability of directional pressure relief.

[0124] It should be noted that the U-shaped casing 21 can be encapsulated with the soft-pack battery cell 22 disposed therein and the busbar brackets 23 located at both ends therein. After encapsulation, at least one side of the U-shaped casing 21 is bonded and fixed to the housing 10 by an adhesive layer 12. When subjected to thermal runaway inside the battery pack 20, the high-pressure gas flow of thermal runaway pushes the U-shaped casing 21 to generate a force that causes it to detach from the adhesive layer 12. Therefore, the adhesive strength of the adhesive layer 12 needs to be not less than 1 MPa so that the adhesive force provided by the adhesive layer 12 is greater than the thermal runaway force that the U-shaped casing 21 can withstand. Similarly, the connecting part 231 is used to connect with the U-shaped casing 21. The force of the high-pressure gas flow is mainly characterized by the shear force that causes the connecting part 231 to undergo shear deformation. Therefore, the shear strength of the connecting part 231 needs to be not less than 0.1 MPa.

[0125] The internal environment of the housing 10 can be simulated by setting up a simulated housing 10 and arranging a battery pack 20 inside it, and causing thermal runaway inside the battery pack 20 (e.g., short-circuiting between adjacent soft-pack battery cells 22 to trigger it). Then, connection parts 231 with different shear strengths can be selected to obtain a first preset value through multiple tests. Alternatively, adhesive layers 12 with different bonding strengths can be selected to connect the battery pack 20 and the housing 10 to obtain a second preset value through multiple tests. Of course, the first and second preset values ​​can also be obtained through simulation analysis. Alternatively, pressure gauges and tension gauges can be set up to measure local forces and further calculate the first and second preset values.

[0126] According to the battery device 100 of this application embodiment, by making the connection strength between the connecting part 231 and the covering shell 21 greater than the structural strength of the pressure relief part 2111, the shear strength of the connecting part 231 greater than a first preset value, and the adhesive strength of the adhesive layer 12 greater than a second preset value, when thermal runaway occurs inside the battery pack 20, the pressure relief part 2111 can be ruptured preferentially to release pressure in a directional manner. During the directional pressure relief process, the probability of connection failure between the connecting part 231 and the covering shell U-shaped covering shell 21, and between the U-shaped covering shell 21 and the adhesive layer 12 is lower, thereby improving the reliability and stability of directional pressure relief, and thus improving the reliability of the battery device 100.

[0127] Referring to Figures 3, 6, and 9, according to some embodiments of this application, the U-shaped encasing shell 21 includes: a first plate 211 forming a pressure relief portion 2111 and a second plate 212 located on both sides of the first plate 211; a busbar busbar bracket 23 is located at both ends of the length of the U-shaped encasing shell 21, and the connecting portion 231 is connected to the first plate 211 and / or the second plate 212.

[0128] Specifically, the first plate 211 is located at the top of multiple pouch battery cells 22 and covers the top of the pouch battery cells 22. The pouch battery cells 22 can have a pressure relief part 2111 formed on at least the circumferential surface 2212 at the top. The pressure relief parts 2111 are arranged correspondingly to achieve directional pressure relief. The two ends of the U-shaped covering shell 21 (the two ends of the length of the pouch battery cells 22) are provided with current collector brackets 23. The current collector brackets 23 can be connected to the first plate 211, or they can be connected to the second plate 212, or the current collector brackets 23 can be connected to both the first plate 211 and the second plate 212 at the same time.

[0129] In this way, the connecting part 231 is connected to at least one of the first plate 211 and the second plate 212 to improve the connection strength between the busbar support 23 and the U-shaped casing 21, thereby improving the directional pressure relief stability and the reliability of the battery device 100.

[0130] It is understood that in the embodiments of this application, the connecting part 231 and the first plate 211, and / or the second plate 212 can be constructed in various connection forms such as plug-in fit, welding fit, or snap-fit ​​fit to achieve a stable and reliable connection. The connection structure of the connecting part 231 and the first plate 211, and / or the second plate 212 of this application will be specifically described below with reference to Figures 3, 4 and 5 using three specific embodiments. The following three specific embodiments are only exemplary descriptions to facilitate those skilled in the art to understand the technical solution of this application, and are not an exhaustive list of feasible embodiments of this application.

[0131] First embodiment:

[0132] As shown in Figures 3, 4 and 5, in the first embodiment, the connecting part 231 includes a plug-in post, and the connecting part 231 is inserted into a slot on the first plate 211 and / or the second plate 212.

[0133] Specifically, slots are provided at the ends of the first plate 211 and / or the second plate 212, and the connecting part 231 includes a plug assembly, or the connecting part 231 includes a slot, and plug posts are provided on the first plate 211 and / or the second plate 212, with the plug posts inserted into the slots.

[0134] Therefore, the busbar bracket 23 and the U-shaped cover shell 21 can be plugged together to achieve fastening, which can reduce assembly difficulty and improve assembly efficiency while improving connection strength.

[0135] Furthermore, the orthographic projection dimension of the plug pin toward the slot is larger than the opening dimension of the slot, so that the plug pin and the slot have an interference fit.

[0136] In embodiments where both the first plate 211 and the second plate 212 are connected to the connecting portion 231, the slot can be an L-shaped slot. In embodiments where either the first plate 211 or the second plate 212 is connected to the connecting portion 231, the slot can be a straight slot. The opening size of the slot is L1, and the thickness of the end or insertion post of the first plate 211 and / or the second plate 212 that mates with the slot is L2, and L1 is greater than L2, so that the connecting portion 231 and the first plate 211 and / or the second plate 212 are configured as an interference fit, thereby improving the connection strength between the connecting portion 231 and the U-shaped covering shell 21, thereby improving the directional pressure relief stability and the reliability of the battery device 100.

[0137] It should be noted that the interference fit means that in the embodiment where the projection size of the plug pin toward the slot is smaller than the opening size of the slot, the slot is also circular and the diameter of the slot is smaller than the diameter of the plug assembly. In the embodiment where the plug pin is square, the slot is also square and at least one of the length and width dimensions of the plug assembly is greater than the length and width dimensions of the plug pin.

[0138] According to some embodiments of this application, the projected size of the plug pin facing the slot is 0.2 mm to 1 mm larger than the opening size.

[0139] In other words, in the first embodiment, the interference fit dimension between the plug and the slot is not less than 0.2mm, which can improve the reliability and stability of the connection between the plug and the slot, and avoid insufficient connection strength between the busbar bracket 23 and the U-shaped cover shell 21 due to the interference being within the tolerance range. Making the interference fit dimension between the plug and the slot not greater than 1mm can reduce the assembly difficulty and reduce the probability of structural damage to the plug during the assembly process, thus extending the service life of the busbar bracket 23.

[0140] Second embodiment:

[0141] As shown in Figures 6, 7 and 8, in the second embodiment, the connecting part 231 includes an overlapping plate, which is connected to the first plate 211 and / or the second plate 212.

[0142] Specifically, in embodiments where the connecting part 231 includes an overlapping plate, the connecting part 231 can be fixedly connected to the first plate 211 and / or the second plate 212 by one or more combinations of screwing, gluing or welding. It can also improve the connection strength between the connecting part 231 and the U-shaped covering shell 21 to improve directional pressure relief stability and improve the reliability of the battery device 100.

[0143] It is understandable that the connecting part 231 can be constructed as a metal part, and the connecting part 231 can be made of the same material as the first plate 211 and the second plate 212, so that the welding difficulty of the connecting part 231 to the first plate 211 and the second plate 212 is lower, the welding strength is higher, and the sealing effect after welding is better.

[0144] According to some embodiments of this application, the overlap size between the overlapping plate and the first plate 211 and / or the second plate 212 is 1mm-5mm.

[0145] In other words, in the second embodiment, making the overlap size not less than 1mm can improve the connection strength between the connecting part 231 and the U-shaped covering shell 21, and reduce the probability of false welding, poor welding and insufficient adhesive strength. Making the overlap size not greater than 5mm can also reduce the space occupied by the connecting part 231 while ensuring the connection strength, so as to take into account the energy density of the battery pack 20.

[0146] According to some embodiments of this application, the overlapping plate is glued, welded or screwed to the first plate 211 and / or the second plate 212.

[0147] Specifically, the ends of the first plate 211 and the second plate 212 overlap with the overlapping plate, or the ends of the first plate 211 and the second plate 212 form an overlapping portion with a thickness less than the thickness of the first plate 211 and the second plate 212 themselves, and the overlapping portion overlaps with the overlapping plate to make the outer surface of the battery pack 20 smoother.

[0148] Structural adhesive can be applied to the overlapping area of ​​the overlapping plate with the first plate 211 and the second plate 212 to achieve adhesive bonding and fixation between the connecting part 231 and the U-shaped covering shell 21. Alternatively, the overlapping area can be welded or screwed together to effectively improve the connection strength between the U-shaped covering shell 21 and the busbar support 23.

[0149] It should be noted that in the embodiment where the overlapping plate is fixed to the first plate 211 and the second plate 212 by screw connection, threaded holes may be provided on the overlapping plate or the first plate 211 and the second plate 212, and the fastener used for thread fastening is constructed as a countersunk screw or a countersunk stud, so as to make the outer surface of the second plate 212 flatter.

[0150] Third embodiment:

[0151] As shown in FIG9, in the third embodiment, according to some embodiments of this application, the connecting part 231 is constructed as a first snap-fit ​​structure, and the length ends of the first plate 211 and / or the second plate 212 are formed with a second snap-fit ​​structure that snaps into the first snap-fit ​​structure.

[0152] Specifically, the first snap-fit ​​structure can be constructed as a snap-fit ​​or a snap-fit ​​groove, and the corresponding second snap-fit ​​structure can be constructed as a snap-fit ​​or a snap-fit ​​groove, so that the busbar support 23 and the U-shaped cover shell 21 can be fixed through the snap-fit ​​cooperation of the first snap-fit ​​structure and the second snap-fit ​​structure, and the same technical effect as the first embodiment and the second embodiment described above can be achieved, which will not be repeated here.

[0153] According to some embodiments of this application, the busbar support 23 further includes: an insulating body 232 and a sealing portion 233. The sealing portion 233 is located between the insulating body 232 and the soft-pack battery cell 22. A connecting portion 231 is connected to the insulating body 232 and is located on at least one side edge of the insulating body 232. A first groove 2321 and a second groove 2322 are formed on the insulating body 232. The first groove 2321 is located on the side surface of the insulating body 232 facing the soft-pack battery cell 22. The second groove 2322 is located on the adjacent side surface of the insulating body 232 and penetrates the insulating body 232. The first groove 2321 and the second groove 2322 are connected. The first groove 2321 is adapted to accommodate the tab, and the second groove 2322 is adapted to accommodate the busbar that is electrically connected to the tab.

[0154] Specifically, the insulating body 232 can be constructed as an insulating structure such as a plastic part or a rubber part. The connecting part 231 can be integrally formed with the insulating body 232. The connecting part 231 can also be constructed as a metal insert and embedded in the insulating body 232. By constructing the connecting part 231 as a metal insert, the connection strength and reliability between the busbar support 23 and the U-shaped cover shell 21 can be improved. At the same time, by separating the connecting part 231 from the tabs, busbars, etc. by the insulating body 232, the probability of short circuit in the battery pack 20 can be reduced, and the reliability of the battery pack 20 can be improved.

[0155] Meanwhile, by providing a sealing part 233 between the insulating body 232 and the U-shaped covering shell 21 and the soft-pack battery cell 22, the sealing performance of the battery pack 20 can be improved, thereby improving the reliability and stability of the battery pack 20. The first groove 2321 and the second groove 2322 on the insulating body 232 can make the electrical connection between the busbar and the tab easier, and the electrical connection between multiple soft-pack battery cells 22 and between adjacent battery packs 20 easier.

[0156] It should be noted that when a single pouch cell 22 experiences thermal runaway, high-temperature and high-pressure gas will be generated inside the pouch cell 22, carrying a certain amount of solid particles and liquids to form a high-temperature gas flow. The temperature and pressure of the high-temperature gas flow generated by the pouch cell 22 are strongly correlated with the energy density of the pouch cell 22. That is, the higher the energy density, the greater the force exerted on the connection area between the U-shaped cover shell 21 and the busbar support 23 during the depressurization process. This places higher demands on the connection strength of the connection area between the U-shaped cover shell 21 and the busbar support 23, the shear strength of the connection part 231 itself, and the adhesive strength of the adhesive layer 12.

[0157] Based on this, this application sets the following limits on the energy density of the soft-pack battery cell 22, the shear strength of the connecting portion 231, the connection strength between the connecting portion 231 and the casing 21, and the adhesive strength of the adhesive layer 12:

[0158] 1. When the energy density of the soft-pack battery cell 22 is 450Wh / L to 600Wh / L, the connection strength between the connecting part 231 and the U-shaped covering shell 21 is 0.1Mpa to 0.2Mpa, the shear strength of the connecting part 231 is 0.1Mpa to 0.2Mpa, and the adhesive strength of the adhesive layer 12 is 1Mpa to 2.5Mpa;

[0159] 2. When the energy density of the soft-pack battery cell 22 is 600Wh / L to 700Wh / L, the shear strength of the connecting part 231 and the covering shell 21 is 0.2Mpa to 0.3Mpa, and the adhesive strength of the adhesive layer 12 is 2.5Mpa to 5.5Mpa.

[0160] 3. When the energy density of the soft-pack battery cell 22 is greater than 700Wh / L, the shear strength of the connection between the connecting part 231 and the covering shell 21 is 0.3Mpa~0.5Mpa, and the adhesive strength of the adhesive layer 12 is 5.5Mpa~10.5Mpa.

[0161] Specifically, when the energy density of the pouch cell 22 is less than 450Wh / L, the pressure acting on the connection area between the connector 231 and the U-shaped casing 21 during thermal runaway is relatively small, the shear force borne by the connector 231 is relatively small, and the tear force borne by the adhesive layer 12 is relatively small. The shear strength of the connection between the conventional connector 231 and the casing 21 and the adhesive force of the conventional adhesive layer 12 are sufficient to meet the pressure requirements for directional pressure relief. Therefore, this application does not impose further limitations on it. However, when the energy density of the pouch cell 22 is greater than or equal to 450Wh / L and less than 600Wh / L, the pressure acting on the connector 231 during thermal runaway is relatively small. As the pressure in the connection area between the 1 and the U-shaped casing 21 increases, the shear force on the connection 231 and the tear force on the adhesive layer 12 also increase accordingly. At this time, the shear strength of the conventional connection between the connection 231 and the casing 21, and the adhesive force provided by the conventional adhesive layer 12, cannot meet the pressure requirements for directional pressure relief. The shear strength of the connection between the connection 231 and the casing 21 only needs to be greater than 0.1 MPa and less than or equal to 0.2 MPa, and the adhesive strength of the adhesive layer 12 only needs to be greater than 1 MPa and less than or equal to 2.5 MPa. When the energy density of the soft-pack battery cell 22 is greater than or equal to 600 Wh / L and less than... At 700Wh / L, when thermal runaway occurs, the pressure acting on the connection area between the connector 231 and the U-shaped casing 21 increases again. The shear force on the connector 231 and the tear force on the adhesive layer 12 both increase again. At this point, the shear strength of the conventional connector 231 and the adhesive force provided by the conventional adhesive layer 12 cannot meet the pressure requirements for directional pressure relief. The shear strength between the connector 231 and the casing 21 only needs to be greater than 0.2 MPa and less than or equal to 0.3 MPa, and the adhesive strength of the adhesive layer 12 only needs to be greater than 2.5 MPa and less than or equal to 5.5 MPa. When the pressure of the soft-pack battery cell 22... When thermal runaway occurs, the pressure acting on the connection area between the connector 231 and the U-shaped cover shell 21 increases further when the energy density is greater than or equal to 700 Wh / L. The shear force borne by the connector 231 and the tear force borne by the adhesive layer 12 also increase further. At this time, the shear strength of the conventional connector 231 and the adhesive force provided by the conventional adhesive layer 12 cannot meet the pressure requirements of directional pressure relief. The shear strength of the connection between the connector 231 and the cover shell 21 only needs to be greater than 0.3 MPa and less than or equal to 0.5 MPa, and the adhesive strength of the adhesive layer 12 only needs to be greater than 5.5 MPa and less than or equal to 10.5 MPa.

[0162] Therefore, based on energy density, the shear connection strength between the connecting part 231 and the covering shell 21 can be reasonably set. This can avoid the connection strength between the connecting part 231 and the covering shell 21 being too low, reducing the probability of connection part 231 failure, and ensuring that the connection strength between the connecting part 231 and the U-shaped covering shell 21 can meet the directional pressure relief requirements. It can also avoid the connection strength being too high, thus avoiding structural redundancy and reducing costs. At the same time, reasonably setting the bonding strength of the adhesive layer 12 can also reduce the probability of connection failure between the battery pack 20 and the box 10, especially the probability of connection failure between the U-shaped covering shell 21 and the box 10, in order to meet the directional pressure relief requirements.

[0163] It should be noted that the shear strength of the connecting part 231 and the adhesive strength of the adhesive layer 12 can be measured by simulating the internal environment of the box 10 and conducting an inflation test. That is, a test sample of the same material and thickness as the U-shaped shell 21 is connected to the manifold bracket 23 to form a sealed space. Air is injected into the sealed space, and the pressure in the sealed space is recorded when the connecting part 231 is disengaged from the U-shaped shell 21 or when the adhesive layer 12 is disengaged from the U-shaped shell 21. The adhesive strength of the connecting part 231 of the manifold bracket 23 and the adhesive strength of the connecting part 231 are calculated from the pressure. The shear strength can be measured by other destructive tests, such as bonding strength, shear strength, and adhesive strength between the connecting part 231 and the covering shell 21, or bonding strength between the adhesive layer 12. For example, tensile tests can be used when the connecting part 231 is glued, welded, screwed, or snapped to the covering shell 21. In the embodiment where the connecting part 231 is glued or welded to the covering shell 21, shear tests can also be used to measure the shear strength. Similarly, the adhesive strength between the adhesive layer 12 and the U-shaped covering shell 21 can be obtained by tensile tests.

[0164] For example, for a specific product with a soft-pack battery cell 22 having a length of 355mm, a height of 123mm, and a width of 13.8mm, the following table shows the runaway temperature, internal pressure, and adhesive layer bonding strength at different energy densities:

[0165] As shown in the table above, the soft-pack battery cell 22 of this application has a shear strength of 0.1 MPa to 0.2 MPa (greater than or equal to 0.1 MPa and less than 0.2 MPa) and an adhesive strength of 1 MPa to 2.5 MPa (greater than or equal to 1 MPa and less than 2.5 MPa) when the energy density is in the range of 600 Wh / L to 700 Wh / L (greater than or equal to 600 Wh / L and less than or equal to 700 Wh / L). When the energy density is in the range of 0.2 MPa to 0.3 MPa (greater than or equal to 0.12 MPa), the adhesive strength is also specified. When the energy density is above 700Wh / L (greater than 700Wh / L), the shear connection strength is 0.3Mpa to 0.5Mpa (greater than or equal to 0.3Mpa and less than 0.5Mpa), and the adhesive strength is 2.5Mpa to 10.5Mpa (greater than or equal to 2.5Mpa and less than 10.5Mpa). The shear connection strength can be higher than the internal pressure, and the adhesive force corresponding to the adhesive strength can be greater than the sto-force, so as to ensure the reliability and stability of the connection between the connection part 231 and the U-shaped cover shell 21, and the battery pack 20 and the box 10.

[0166] As shown in Figure 2, the battery device 100 includes: a housing 10 and a battery pack 20. The battery pack 20 is at least one and includes: at least one soft-pack battery cell 22 as described in the above embodiment and a U-shaped covering shell 21. At least one side surface of the U-shaped covering shell 21 has a weak portion 2113.

[0167] The housing 10 has an accommodating space, and one or more battery packs 20 are disposed in the accommodating space. Each battery pack 20 has one or more soft-pack battery cells 22 disposed inside the U-shaped housing 21 of its casing. The soft-pack battery cells 22 are constructed as described above using the flexible housing 221.

[0168] The U-shaped cover 21 is used to cover at least one of the plurality of circumferential surfaces 2212 and two side surfaces 2211 of the soft-pack battery cell 22. A weak portion 2213 is provided on at least one circumferential surface 2212 of the soft-pack battery cell 22. A pressure relief portion 2111 is formed on at least one side surface (such as the first plate 211) of the U-shaped cover 21, such as the pressure relief portion 2111 being opposite to the weak portion 2213, or the pressure relief portion 2111 being located on the first surface of the U-shaped cover 21, while the weak portion 2213 is opposite to the second surface of the U-shaped cover 21, and the first surface and the second surface are adjacent.

[0169] Therefore, by providing a pressure relief section 2111 on the U-shaped casing 21 that cooperates with the weak section 2113, when the soft-pack battery cell 22 experiences thermal runaway, the high-temperature gas flow discharged through the pressure relief area (weak section 2213) can be further released outward through the pressure relief section 2111. By cooperating with the weak section 2213 and the pressure relief section 2111, the high-temperature gas flow can be directionally discharged, thereby improving the reliability of the battery device 100.

[0170] According to some embodiments of this application, the U-shaped encasing shell 21 includes a first plate 211 and a second plate 212 located on both sides of the first plate 211. A pressure relief portion 2111 is formed on the first plate 211, and a weak portion 2113 is at least partially opposite to the pressure relief portion 2111.

[0171] Specifically, the first plate 211 and the second plates 212 located on both sides of the first plate 211 define a generally U-shaped covering shell 21, such that the first plate 211 of the covering shell 21 can be opposite to one circumferential surface 2212 of the soft-pack battery cell 22, while the two second plates 212 can be opposite to the two side surfaces 2211 of the soft-pack battery cell 22 respectively, and the weak portion 2213 formed on the circumferential surface 2212 can be at least partially opposite to the pressure relief portion 2111 formed on the first plate 211.

[0172] It should be noted that the weak part 2113 and the pressure relief part 2111 are at least partially opposite to each other, meaning that the weak part 2213 formed on the circumferential surface 2212 projects toward the first plate 211 and the projected outline at least partially overlaps with the outline of the pressure relief part 2111.

[0173] In this way, on the one hand, the gas and fire generated after thermal runaway of the pouch battery cell 22 can be discharged in a directional manner, achieving orderly discharge to reduce damage, especially secondary damage. On the other hand, the connection path between the pressure relief zone and the pressure relief section 2111 is shorter, which can achieve rapid discharge while the gas and fire flow stays inside the U-shaped covering shell 21 for a shorter time, thus having less impact on other pouch battery cells 22 around the thermally runaway pouch battery cell 22. This can also further reduce the spread rate of thermal runaway and improve the reliability of the battery pack 20 and the battery device 100.

[0174] According to some embodiments of this application, the second plate 212 is opposite to the side 2211, and the projected outline area of ​​the second plate 212 toward the side 2211 of the flexible shell 221 is less than or equal to the area of ​​the side 2211.

[0175] Specifically, the circumferential surface 2212 is defined as including a first surface and a second surface opposite to it. The first surface is opposite to the first plate 211, and the second surface is disposed away from the first plate 211. The second surface is used to connect to the housing 10. The two sides of the first and second surfaces are the two side surfaces 2211 of the soft-pack battery cell 22, and the two ends of the first and second surfaces are the other two circumferential surfaces 2212 of the soft-pack battery cell 22. The second plate 212 is opposite to the side surface 2211 to limit the soft-pack battery cell 22 in the direction of the second plate 212. The area of ​​the surface of the second plate 212 opposite to the side surface 2211 can be less than or equal to the area of ​​the side surface 2211.

[0176] In other words, in some embodiments, the size of the second plate 212 is the same as the size of the side 2211, while in other embodiments, the size of the second plate 212 is smaller than the size of the side 2211. On the one hand, this can avoid the second plate 212 being too large, which would prevent the second side from being connected to the housing 10, thus improving the stability and reliability of the battery pack 20 within the housing 10. On the other hand, the second plate 212 can use less material, which can also reduce the material cost of the battery pack 20 and the battery device 100.

[0177] As shown in Figures 3, 6 and 9, according to some embodiments of this application, the first plate 211 is spaced apart from the side of the circumferential surface 2212 with the weak portion 2213 to define the exhaust passage a.

[0178] In this way, the high-temperature gas flow generated after the weak part 2213 ruptures can be released to the exhaust channel a first, and after being initially buffered by the exhaust channel a, it can be discharged through the pressure relief part 2111. This can reduce the pressure of the high-temperature gas flow after it flows out of the pressure relief part 2111, thereby reducing the impact and damage after the thermal runaway of the soft-pack battery cell 22.

[0179] According to some embodiments of this application, the first plate 211 is constructed as a flat plate or an arc plate.

[0180] That is, in some embodiments, the first plate 211 is constructed as a flat plate, while in other embodiments, the first plate 211 is constructed as an arc-shaped plate.

[0181] According to some embodiments of this application, there are multiple pressure relief sections 2111, which are spaced apart in the length direction and / or width direction of the first plate 211.

[0182] Therefore, each of the multiple weak points 2213 on each pouch cell 22 can have a corresponding pressure relief part 2111, so that the high-temperature gas flow buffered by the exhaust channel a can be directly discharged through the corresponding pressure relief part 2111, thereby increasing the discharge speed and reducing the residence time of the high-temperature gas flow in the exhaust channel a during the discharge process, thereby reducing the spread speed of thermal runaway between adjacent pouch cells 22 in the battery pack 20 and improving the reliability of the battery pack 20.

[0183] According to some embodiments of this application, the U-shaped covering shell 21 is constructed as an aluminum shell or a stainless steel shell.

[0184] It is understood that in some embodiments, the U-shaped covering shell 21 is constructed of aluminum, while in other embodiments, it is constructed of stainless steel. This is to ensure that the temperature resistance and structural strength of the U-shaped covering shell 21 are much higher than those of a flexible shell. By using the U-shaped covering shell 21 with a certain structural strength and rigidity to support and protect the soft-pack battery cell 22, the structural strength of the battery pack 20 can be improved, the thermal runaway propagation rate between adjacent battery packs 20 can be reduced, and the reliability of the battery device 100 can be improved.

[0185] Referring to Figure 12, according to some embodiments of this application, the housing 10 has a bottom plate 11, which is connected to the soft-pack battery cell 22 via an adhesive layer 12.

[0186] Specifically, the bottom plate 11 of the housing 10 is connected to the second side of the soft-pack battery cell 22 through an adhesive layer 12 to fix the battery pack 20 on the housing 10, thereby improving the fixation stability and reliability of the battery pack 20.

[0187] Of course, in some embodiments, the adhesive layer 12 is also used for the connection and fixation between the base plate 11 and the second plate 212.

[0188] Referring to Figure 12, according to some embodiments of this application, the base plate 11 includes a cold plate, and the adhesive layer 12 is located between the cold plate and a plurality of soft-pack battery cells 22.

[0189] In some embodiments, the bottom plate 11 of the housing 10 is formed as a cold plate, and the cold plate is connected to the soft-pack battery cell 22 through an adhesive layer 12. In other embodiments, a cold plate is provided between the bottom plate 11 and the soft-pack battery cell 22, and the cold plate is connected to the soft-pack battery cell 22 through an adhesive layer 12.

[0190] In other words, the adhesive layer 12 is constructed as a structural adhesive, and the base plate 11 with the cold plate is connected to the soft-pack battery cell 22. Under the premise of ensuring that the battery pack 20 is stably and reliably fixed in the housing 10, the temperature of the battery pack 20 can also be regulated by the cold plate, so that the battery pack 20 can work at a suitable temperature. This can improve the working stability and reliability of the battery pack 20, reduce the probability of the battery pack 20 overheating, reduce the probability of thermal runaway of the battery pack 20, and thus improve the reliability of the battery pack 20 and even the battery device 100.

[0191] As shown in FIG12, according to some embodiments of the present application, the adhesive layer 12 includes an adhesive layer body 121 and an overflow portion 122. The overflow portion 122 is located on the side of the adhesive layer body 121 facing the plurality of pouch battery cells 22, and is located between adjacent pouch battery cells 22, and / or between the pouch battery cells 22 and the second plate 212.

[0192] In other words, when the structural adhesive is used to connect and fix the soft-pack battery cell 22 to the cold plate, at least part of the adhesive layer 12 overflows between adjacent soft-pack battery cells 22 and / or between the second plate 212 and the soft-pack battery cell 22, forming an overflow portion 122. By setting the overflow portion 122, not only can the area between the adhesive layer 12 and the soft-pack battery cell 22 and between the adhesive layer 12 and the second plate 212 be increased, thereby improving the fixing stability and reliability of the battery pack 20 on the housing 10, but the overflow portion 122 can also fill the gaps between adjacent soft-pack battery cells 22 and between the soft-pack battery cell 22 and the second plate 212, thereby limiting the soft-pack battery cell 22 and the U-shaped housing 21, reducing the movement of the battery pack 20 within the housing 10, and reducing the movement of the soft-pack battery cell 22 within the U-shaped housing 21.

[0193] According to some embodiments of this application, the soft-pack battery cell 22 is any one of a lithium iron phosphate battery cell, a ternary lithium battery cell, and a solid-state battery cell.

[0194] In other words, in some embodiments, the pouch battery cell 22 is constructed as a lithium iron phosphate battery, in some embodiments, the pouch battery cell 22 is constructed as a ternary lithium battery cell, and in some embodiments, the pouch battery cell 22 is constructed as a solid-state battery cell.

[0195] Solid-state battery cells can be, but are not limited to, polymer solid-state battery cells, oxide solid-state battery cells, sulfide solid-state battery cells, halide solid-state battery cells, etc. Solid-state battery cells can also be semi-solid-state battery cells or all-solid-state battery cells.

[0196] In the above technical solutions, in the embodiments of this application that are constructed as lithium iron phosphate battery cells, the reliability of the pouch battery cells can be improved and the cycle life of the pouch battery cells can be extended. In the embodiments of this application that are constructed as ternary lithium battery cells, the energy density of the pouch battery cells can be improved and the driving range can be increased. In the embodiments of this application that are constructed as solid-state pouch battery cells, not only the energy density can be improved, but also the reliability can be improved.

[0197] According to some embodiments of this application, when the pouch battery cell 22 is a lithium iron phosphate (LiFeO4) battery cell, the ratio of positive electrode active material, positive electrode binder, and positive electrode conductive agent in the positive electrode material of the pouch battery cell 22 is 96:1-3:1-3; when the pouch battery cell 22 is a ternary lithium battery cell, the ratio of positive electrode active material, positive electrode binder, and positive electrode conductive agent in the positive electrode material of the pouch battery cell 22 is 96:2-3:1-2.

[0198] It is understandable that when the pouch cell 22 is a lithium iron phosphate battery cell, the positive electrode material of the pouch cell 22 has the following proportions: the positive electrode active material accounts for 96 parts of the total weight of the positive electrode material; the binder accounts for 1 to 3 parts of the total weight of the positive electrode material (for example, it may include but is not limited to 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, etc.); and the conductive agent accounts for 1 to 3 parts of the total weight of the positive electrode material (for example, it may include but is not limited to 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, etc.).

[0199] For example, when the pouch cell 22 is a lithium iron phosphate battery cell, the positive electrode active material is LFP (which can refer to LiFePO4, i.e., lithium iron phosphate), the binder can be PVDF (polyvinylidene fluoride), and the conductive agent can be conductive carbon black. The ratio of LFP:PVDF:conductive carbon black can be 96:2:2, meaning that the total weight of the positive electrode active material is divided into 100 parts, with LFP accounting for 96 parts, PVDF accounting for 2 parts, and conductive carbon black also accounting for 2 parts. The weight unit of the positive electrode active material can be grams.

[0200] When the pouch cell 22 is a ternary lithium battery cell, in the positive electrode material of the pouch cell 22, the positive electrode active material accounts for 96 parts of the total weight of the positive electrode material, the binder accounts for 2 to 3 parts of the total weight of the positive electrode material (for example, including but not limited to 2, 2.2, 2.5, 2.8, 3, etc.), and the conductive agent accounts for 1 to 2 parts of the total weight of the positive electrode material (for example, including but not limited to 1, 1.2, 1.5, 1.8, 2, etc.). The ternary lithium battery cell can be, but is not limited to, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, etc.

[0201] For example, the ternary material of the ternary battery cell can be an octet LiNi. 0.8 Co 0.1 Mn 0.1 The weight ratio of O2, positive electrode active material, binder, and conductive agent is 96:2.5:1.5, meaning the total weight of the positive electrode material is divided into 100 parts. (This refers to the octet LiNi...) 0.8 Co 0.1 Mn 0.1 The composition of O2 is 96 parts, the composition of adhesive is 2.5 parts, and the composition of conductive agent is 1.5 parts.

[0202] In the above technical solutions, when the pouch battery cell 22 is a lithium iron phosphate battery cell, a high proportion of positive electrode active material means that more substances capable of electrochemical reactions can be accommodated within a limited electrode assembly. This is beneficial for increasing the capacity and energy density of the battery device 100, enabling the lithium iron phosphate battery cell to output higher power while maintaining a relatively small volume and weight, meeting the application scenarios with certain energy density requirements. Using the above-mentioned range for the amount of binder and conductive agent can reduce the cost of auxiliary materials, thereby reducing the overall cost of the battery device 100. When the pouch battery cell 22 is a ternary battery cell, due to the relatively complex structure and surface properties of ternary materials, using the above-mentioned proportions of positive electrode active material, binder, and conductive agent helps to ensure good adhesion between positive electrode active material particles and between the active material and the current collector, thereby improving the mechanical stability and integrity of the electrode assembly. This helps to reduce the risk of active material detachment and electrode pulverization during charging and discharging, and extends the cycle life of the battery device 100.

[0203] This application proposes an electrical device 200, including: the battery device 100 in the above embodiments.

[0204] Furthermore, as shown in Figure 1, the electrical equipment 200 can be a vehicle, and the battery device 100 can be integrated into the vehicle chassis. That is, the vehicle body structure is a split body, with the upper body and the integrated intelligent chassis assembled together, and the battery device 100 forming part of the integrated intelligent chassis. In this way, the top plate of the box 10 can also participate in defining the vehicle floor, which can save the meaningless stacking of multiple layers of sheet metal, reduce material costs, and make the space occupation of the chassis more reasonable. The space inside the chassis for accommodating the battery device 100 is larger and the energy density is higher.

[0205] It is understandable that the electrical equipment 200 is constructed as a vehicle, that is, the vehicle uses the aforementioned battery device 100. The battery device 100 has higher energy density and higher reliability, which can improve the vehicle's driving range and driving safety.

[0206] Other configurations and operations of the soft-pack battery cell 22, battery device 100, and electrical equipment 200 according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0207] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0208] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

[0209] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0210] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery device (100), wherein, include: Box (10); The battery pack (20) includes a U-shaped casing (21), multiple soft-pack battery cells (22), and a busbar bracket (23); the U-shaped casing (21) is connected to the housing (10), the busbar bracket (23) is disposed on the U-shaped casing (21) and connected to the U-shaped casing (21) through a connecting part (231), the U-shaped casing (21), the housing (10), and the busbar bracket (23) together form an accommodating space, and the multiple soft-pack battery cells (22) are disposed in the accommodating space and electrically connected through the busbar bracket (23); The U-shaped shell (21) has a pressure relief part (2111), and the connection strength between the connecting part (231) and the U-shaped shell (21) is greater than the structural strength of the pressure relief part (2111).

2. The battery device (100) according to claim 1, wherein, The U-shaped enclosure (21) includes a first plate (211) forming the pressure relief section (2111) and a second plate (212) located on both sides of the first plate (211). The manifold bracket (23) is located at both ends of the length of the U-shaped enclosure (21), and the connecting part (231) is connected to the first plate (211) and / or the second plate (212).

3. The battery device (100) according to claim 1 or 2, wherein, The connecting part (231) includes a plug post, which is inserted into a slot formed on the first plate (211) and / or the second plate (212).

4. The battery device (100) according to claim 3, wherein, The orthographic projection of the plug towards the slot is larger than the opening size of the slot, so that the plug and the slot are in an interference fit.

5. The battery device (100) according to claim 4, wherein, The projected size of the plug pin toward the slot is 0.2mm to 1mm larger than the opening size.

6. The battery device (100) according to claim 1 or 2, wherein, The connecting part (231) includes an overlapping plate, which is connected to the first plate (211) and / or the second plate (212).

7. The battery device (100) according to claim 6, wherein, The overlap size between the overlapping plate and the first plate (211) and / or the second plate (212) is 1mm-5mm.

8. The battery device (100) according to claim 6, wherein, The overlapping plate is glued, welded or screwed to the first plate (211) and / or the second plate (212).

9. The battery device (100) according to claim 1 or 2, wherein, The connecting part (231) includes a first snap-fit ​​structure, and the length ends of the first plate (211) and / or the second plate (212) are formed with a second snap-fit ​​structure that snaps into the first snap-fit ​​structure.

10. The battery device (100) according to any one of claims 1-9, wherein, The busbar bracket (23) further includes an insulating body (232) and a sealing portion (233). The sealing portion (233) is located between the insulating body (232) and the soft-pack battery cell (22). The connecting portion (231) is connected to the insulating body (232) and is located on at least one side edge of the insulating body (232). A first groove (2321) and a second groove (2322) are formed on the insulating body (232). The first groove (2321) is located on the side surface of the insulating body (232) facing the soft-pack battery cell (22). The second groove (2322) is located on the adjacent side surface of the insulating body (232) and penetrates the insulating body (232). The first groove (2321) and the second groove (2322) are connected. The first groove (2321) is adapted to accommodate the tab, and the second groove (2322) is adapted to accommodate the busbar that is electrically connected to the tab.

11. The battery device (100) according to claim 10, wherein, When the energy density of the soft-pack battery cell (22) is 450Wh / L to 600Wh / L, the connection strength between the connecting part (231) and the U-shaped covering shell (21) is 0.1Mpa to 0.2Mpa; When the energy density of the pouch cell (22) is 600Wh / L to 700Wh / L, the connection strength between the connecting part (231) and the U-shaped covering shell (21) is 0.2MPa to 0.3MPa. When the energy density of the soft-pack battery cell (22) is greater than 700Wh / L, the connection strength between the connecting part (231) and the U-shaped covering shell (21) is 0.3Mpa to 0.5Mpa.

12. The battery device (100) according to claim 2, wherein, The number of pressure relief parts (2111) is multiple, and the multiple pressure relief parts (2111) are spaced apart in the length direction and / or width direction of the first plate (211).

13. The battery device (100) according to any one of claims 2-12, wherein, The first plate (211) is constructed as a flat plate or an arc-shaped plate.

14. The battery device (100) according to any one of claims 2-12, wherein, The pouch cell (22) includes: a flexible shell (221) and an electrode assembly (222) disposed within the flexible shell (221). The flexible shell (221) has a side surface (2211) opposite to the large surface of the electrode assembly (222) and a circumferential surface (2212) avoiding the large surface. The second plate (212) is opposite to the side surface (2211).

15. The battery device (100) according to claim 14, wherein, The projected outline area of ​​the second plate (212) facing the side (2211) of the flexible shell (221) is less than or equal to the area of ​​the side (2211).

16. The battery device (100) according to claim 14 or 15, wherein, A weak portion (2213) is formed on the circumferential surface (2212), the weak portion (2213) is opposite to the first plate (211), and the pressure relief portion (2111) is at least partially opposite to the weak portion (2213).

17. The battery device (100) according to claim 16, wherein, The first plate (211) is spaced apart from the side of the circumferential surface (2212) having the weak portion (2213) to define an exhaust passage (a).

18. The battery device (100) according to any one of claims 1-17, wherein, The U-shaped covering shell (21) is constructed of aluminum or stainless steel.

19. The battery device (100) according to any one of claims 2-17, wherein, The side face of the soft-pack battery cell (22) away from the first plate (211) is connected to the housing (10) through an adhesive layer (12).

20. The battery device (100) according to claim 19, wherein, The housing (10) has a bottom plate (11), which is connected to the soft-pack battery cell (22) through the adhesive layer (12).

21. The battery device (100) according to claim 20, wherein, The base plate (11) includes a cold plate, and the adhesive layer (12) is located between the cold plate and the plurality of soft-pack battery cells (22).

22. The battery device (100) according to claim 20, wherein, The adhesive layer (12) includes an adhesive layer body (121) and an overflow portion (122), wherein the overflow portion (122) is located on the side of the adhesive layer body (121) facing the plurality of pouch battery cells (22), and is located between adjacent pouch battery cells (22), and / or between the pouch battery cells (22) and the second plate (212).

23. The battery device according to any one of claims 1-22, characterized in that, The soft-pack battery cell (22) is any one of lithium iron phosphate battery cell, ternary lithium battery cell, and solid-state battery cell.

24. The battery device according to claim 23, characterized in that, When the pouch battery cell (22) is a lithium iron phosphate battery cell, the ratio of positive active material, positive binder and positive conductive agent in the positive electrode material of the pouch battery cell (22) is 96:1-3:1-3; when the pouch battery cell (22) is a ternary lithium battery cell, the ratio of positive active material, positive binder and positive conductive agent in the positive electrode material of the pouch battery cell (22) is 96:2-3:1-2.

25. An electrical appliance (200), wherein, include: The battery device (100) according to any one of claims 1-24.

26. The electrical equipment (200) according to claim 25, wherein, The electrical equipment (200) is a vehicle.

27. The electrical equipment (200) according to claim 26, wherein, The battery device (100) is integrated into the chassis of the vehicle, and the top cover of the housing (10) participates in defining the vehicle floor.

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